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Life history strategy influences parasite responses to habitat fragmentation.
Anthropogenic habitat use is a major threat to biodiversity and is known to increase the abundance of generalist host species such as rodents, which are regarded as potential disease carriers. Parasites have an intimate relationship with their host and the surrounding environment and it is expected that habitat fragmentation will affect parasite infestation levels. We investigated the effect of habitat fragmentation on the ecto- and endoparasitic burdens of a broad niche small mammal, Rhabdomys pumilio, in the Western Cape Province, South Africa. Our aim was to look at the effects of fragmentation on different parasite species with diverse life history characteristics and to determine whether general patterns can be found. Sampling took place within pristine lowland (Fynbos/Renosterveld) areas and at fragmented sites surrounded and isolated by agricultural activities. All arthropod ectoparasites and available gastrointestinal endoparasites were identified. We used conditional autoregressive models to investigate the effects of habitat fragmentation on parasite species richness and abundance of all recovered parasites. Host density and body size were larger in the fragments. Combined ecto- as well as combined endoparasite taxa showed higher parasite species richness in fragmented sites. Parasite abundance was generally higher in the case of R. pumilio individuals in fragmented habitats but it appears that parasites that are more permanently associated with the host's body and those that are host-specific show the opposite trend. Parasite life history is an important factor that needs to be considered when predicting the effects of habitat fragmentation on parasite and pathogen transmission. PMID:23954434
Froeschke, G—tz; van der Mescht, Luther; McGeoch, Melodie; Matthee, Sonja
Cometary habitats for primitive life.
Comet Halley studies indicate most of the nucleus is covered by an insulating crust, presumed of pyrolysed organic material. The subcrust is warmed and percolated by gases within 2AU, so provides one habitat for primitive replicating organisms. Cracks and crevices within contaminated ice in the craters provides a habitat for photosynthesising organisms. Subsurface lakes on the Europa model, though insulated by some metres of ice, would require a trigger (perhaps meteorite impact and energy source (chemical or metabolic energy) to initiate and maintain a suitable-habitat on short period comets. Constraints on transfer between comets and other planetary bodies implies that radiation-resistant species with lengthy hibernation potential would be expected. PMID:11538150
Wallis, M K; Wickramasinghe, N C; Hoyle, F
Architecture and life support systems for a rotating space habitat
NASA Astrophysics Data System (ADS)
Life Support Systems are critical to sustain human habitation of space over long time periods. As orbiting space habitats become operational in the future, support systems such as atmo-sphere, food, water etc. will play a very pivotal role in sustaining life. To design a long-duration space habitat, it's important to consider the full gamut of human experience of the environment. Long-term viability depends on much more than just the structural or life support efficiency. A space habitat isn't just a machine; it's a life experience. To be viable, it needs to keep the inhabitants satisfied with their condition. This paper provides conceptual research on several key factors that influence the growth and sustainability of humans in a space habitat. Apart from the main life support system parameters, the architecture (both interior and exterior) of the habitat will play a crucial role in influencing the liveability in the space habitat. In order to ensure the best possible liveability for the inhabitants, a truncated (half cut) torus is proposed as the shape of the habitat. This structure rotating at an optimum rpm will en-sure 1g pseudo gravity to the inhabitants. The truncated torus design has several advantages over other proposed shapes such as a cylinder or a sphere. The design provides minimal grav-ity variation (delta g) in the living area, since its flat outer pole ensures a constant gravity. The design is superior in economy of structural and atmospheric mass. Interior architecture of the habitat addresses the total built environment, drawing from diverse disciplines includ-ing physiology, psychology, and sociology. Furthermore, factors such as line of sight, natural sunlight and overhead clearance have been discussed in the interior architecture. Substantial radiation shielding is also required in order to prevent harmful cosmic radiations and solar flares from causing damage to inhabitants. Regolith shielding of 10 tons per meter square is proposed for the habitat. In order to ensure Thermal control of the habitat, multiple radiators on the exterior and a thermal shield on the inner circumference of the habitat are proposed. Food production on-board the habitat is proposed to be facilitated through vertical farming systems. These multi-storey farming systems are known to be more efficient in terms of area and sustainable than conventional farms. Agriculture on-board these farms are proposed to be facilitated through hydroponics and enriched regolith. Apart from food production, these farms can cater to fish farming as means of food, animal and insect breeding. In order to ensure waste treatment of organic matter, a biogas plant is proposed in the habitat which can be used to generate electrical or mechanical power .An optimum atmospheric pressure of 51.1Kpa is proposed for the habitat comprising of Oxygen and Helium. Recreational facilities although not directly related to life support systems, play a very important role in optimum liveability of inhabitants. Open spaces, sports facilities, micro gravity swimming pools, orbital hotels are proposed as modes of recreation to ensure long term sustainability for the inhabitants.
Misra, Gaurav
Comparative phylogeography of two sister (congeneric) species of cardiid bivalve: Strong influence of habitat, life history and post-glacial history
NASA Astrophysics Data System (ADS)
Sister (congeneric) species may exhibit disparate patterns of biogeographic genetic structures due to different life histories and habitat preferences. The common cockle Cerastoderma edule and the lagoon cockle Cerastoderma glaucum probably diverged from their common ancestor in the present territory of Sahara around 5 million years ago. Although it is difficult to separate both species morphologically, various genetic markers, both mitochondrial and nuclear, clearly distinguish them. Furthermore, their lifestyles are different, as C. edule has a much less fragmented coastal habitat and a longer duration of pelagic larval stage than C. glaucum. A comparative genetic analysis was conducted on 17 populations of C. edule and 13 populations of C. glaucum using a 506 bp fragment of mitochondrial DNA (COI). We tested the hypothesis that differences in habitat types and life history are reflected in the genetic structure patterns of these two cockles. Indeed substantial differences in population genetic structures between them are revealed. Genetic diversity within C. glaucum populations decreases northwards as a consequence of post-glacial (re)colonization from southern refugia, while C. edule displays an opposite pattern indicating survival in glacial refuges in the northern Atlantic. Among populations within geographic groups, genetic differentiation is low in C. edule, probably as a result of larval dispersal with coastal currents, while it is extremely high in C. glaucum, best explained by the fragmented habitats. Interestingly, long distance divergence is less expressed in C. glaucum than in C. edule, which supports the speculation that migrating birds (frequently observed in lagoons) may occasionally transport the former more often or more efficiently than the latter. The approach applied in this study (e.g., rarefaction procedure, selection of samples of both species from the same regions) enabled a new and reliable comparative analysis of the existing raw datasets.
Tarnowska, Katarzyna; Krakau, Manuela; Jacobsen, Sabine; Wo?owicz, Maciej; FÕral, Jean-Pierre; Chenuil, Anne
The habitat and nature of early life.
Earth is over 4,500 million years old. Massive bombardment of the planet took place for the first 500-700 million years, and the largest impacts would have been capable of sterilizing the planet. Probably until 4,000 million years ago or later, occasional impacts might have heated the ocean over 100 degrees C. Life on Earth dates from before about 3,800 million years ago, and is likely to have gone through one or more hot-ocean 'bottlenecks'. Only hyperthermophiles (organisms optimally living in water at 80-110 degrees C) would have survived. It is possible that early life diversified near hydrothermal vents, but hypotheses that life first occupied other pre-bottleneck habitats are tenable (including transfer from Mars on ejecta from impacts there). Early hyperthermophile life, probably near hydrothermal systems, may have been non-photosynthetic, and many housekeeping proteins and biochemical processes may have an original hydrothermal heritage. The development of anoxygenic and then oxygenic photosynthesis would have allowed life to escape the hydrothermal setting. By about 3,500 million years ago, most of the principal biochemical pathways that sustain the modern biosphere had evolved, and were global in scope. PMID:11234022
Nisbet, E G; Sleep, N H
Mars polar cap: a habitat for elementary life1
NASA Astrophysics Data System (ADS)
Ices in the Martian polar caps are potential habitats for various species of microorganisms. Salts in the ice and biological anti-freeze polymers maintain liquid in cracks in the ices far below 0¯C, possibly down to the mean 220-240 K. Sub-surface microbial life is shielded from ultraviolet (UV) radiation, but could potentially be activated on south-facing slopes under the midday, midsummer Sun. Such life would be limited by low levels of vapour, little transport of nutrients, low light levels below a protective dirt-crust, frost accumulation at night and in shadows, and little if any active translocation of organisms. As in the Antarctic and in permafrost, movement to new habitats depends on geo-climatic changes, which for Mars's north polar cap occur on a 50 000 year scale, except for rare meteorite impacts.
Wallis, M. K.; Wickramasinghe, N. C.
Influence of microclimate on the life cycle of the common tick Ixodes ricinus (L.) in an open area in comparison with forest habitats.
Under conditions of the South-Moravian region of Pannonian climate (Valtice near Breclav), the life cycle of the common tick Ixodes ricinus (L.) was studied and a continous recording of main elements of microclimate (temperature and humidity) was carried out in an open grassy area. Simultaneously the process of hibernation was studied in four soil layers (surface, depths of 10, 20 and 30 cm). Observations were assessed by mathematiccal-statistical tests and compared with the results obtained by the same methods in the forest biotope (tipe of thermophilic oak forest)and in the ecotone of forest margin (Daniel et al. 1976). The ticks are able to complete the developmental cycle also in the open grassy areas, where during the vegetation period the development proceeds more quickly than in the forest but with considerably higher losses. In the discussion the conclusions are compared with literary data from other parts of Czechoslovakia. PMID:881143
Daniel, M; Cern», V; DusbÃbek, F; HonzÃkovÃ, E; OlejnÚcek, J
Habitat use and ontogenetic shifts of fish life stages at rocky reefs in South-western Mediterranean Sea
NASA Astrophysics Data System (ADS)
The present study aimed at exploring the habitat use by fish life stages and ontogenetic shifts in a South-western Mediterranean rocky reef. The relation with rocky reef habitat structure (complexity, heterogeneity, total cover and depth) was visually surveyed on a monthly basis, in four locations and during one year, for the abundance of young-of-the-year (YOY) and juvenile reef fish. Fish assemblage responded significantly to spatial and temporal variations of structural microhabitat, this response being species-specific. Abundance of fish life stages was directly related to temperature variation, with higher abundances occurring on warmer months. Also, habitat differences occurred between YOY and juveniles of a series of species from shallow steeper rocky habitats to deeper complex rocky bottoms with high total cover. Spatial differences in YOY and juvenile abundance across locations could be attributed to fine-scale habitat preference, from purely rocky, more complex sites, with greater slopes and depths, to sites harbouring more heterogeneous habitats. By characterising the microhabitat association of fish life stages (both YOY and juveniles), and identifying for what species this influence may interfere with spatial and temporal patterns, the present study can be used as a basis for pluriannual monitoring of fish recruitment success in the area in order to better understand their population dynamics.
FÕlix-Hackradt, F. C.; Hackradt, C. W.; Treviþo-Otµn, J.; PÕrez-Ruzafa, A.; GarcÚa-Charton, J. A.
Underground habitats in the RÚo Tinto basin: a model for subsurface life habitats on Mars.
A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the RÚo Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e.g., pO(2), pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO(2), CH(4), and H(2). SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The RÚo Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores. PMID:19105758
FernÃndez-Remolar, David C; Prieto-Ballesteros, Olga; RodrÚguez, Nuria; Gµmez, Felipe; Amils, Ricardo; Gµmez-Elvira, Javier; Stoker, Carol R
Underground Habitats in the RÚo Tinto Basin: A Model for Subsurface Life Habitats on Mars
NASA Astrophysics Data System (ADS)
A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the RÚo Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e.g. , pO2, pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO2, CH4, and H2. SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The RÚo Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores.
FernÃndez-Remolar, David C.; Prieto-Ballesteros, Olga; RodrÚguez, Nuria; Gµmez, Felipe; Amils, Ricardo; Gµmez-Elvira, Javier; Stoker, Carol R.
The Search for Life on Europa: Limiting Environmental Factors, Potential Habitats, and Earth Analogues
The putative ocean of Europa has focused considerable attention on the potential habitats for life on Europa. By generally clement Earth standards, these Europan habitats are likely to be extreme environments. The objectives of this paper were to examine: (1) the limits for biological activity on Earth with respect to temperature, salinity, acidity, desiccation, radiation, pressure, and time; (2) potential
Giles M. Marion; Christian H. Fritsen; Hajo Eicken; Meredith C. Payne
The Search for Life on Europa: Limiting Environmental Factors, Potential Habitats, and Earth Analogues
The putative ocean of Europa has focused considerable attention on the potential habitats for life on Europa. By generally clement Earth standards, these Europan habitats are likely to be extreme environments. The objectives of this paper were to examine: (1) the limits for biolog- ical activity on Earth with respect to temperature, salinity, acidity, desiccation, radiation, pres- sure, and time;
Giles M. Marion; Christian H. Fritsen; Hajo Eicken; Meredith C. Payne
The influence of scale on salmon habitat restoration priorities
Habitat loss and alteration is the leading cause of species' declines world-wide, therefore habitat restoration and protection is a prominent conservation strategy. Despite obvious connections between habitat and threatened or endangered species, conservationists have been hard pressed explicitly to link abundance or population health with habitat attributes. Given that habitat relationships with species are often characterized at a spatial scale
Blake E. Feist; E. Ashley Steel; George R. Pess; Robert E. Bilby
Influence of grain size on specieshabitat models
High resolution remote sensing data facilitate the use of small-scale habitat features such as trees or hedges in the analysis of specieshabitat relationships. Such data potentially enable more accurate specieshabitat mapping than lower resolution data. Here, for the first time, we systematically investigated this hypothesis by altering the spatial resolution from 1m up to 1000m grain size in specieshabitat models
Thomas K. Gottschalk; Birgit Aue; Stefan Hotes; Klemens Ekschmitt
Human disturbance and stage-specific habitat requirements influence snowy plover site occupancy during the breeding season.
Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distribution along the coastal areas on the Florida Panhandle, USA. Our goal was to determine the relative effects of seasonal human disturbance and habitat requirements on snowy plover habitat use. We surveyed 303 sites for snowy plovers, human disturbance, and habitat features between January and July 2009 and 2010. We made multiple visits during three different sampling periods that corresponded to snowy plover breeding: pre-breeding, incubation, and brood-rearing and used multi-season occupancy models to examine whether human disturbance, habitat features, or both influenced site occupancy, colonization (probability of transition from an unoccupied site to an occupied site), and extinction (probability of transition from an occupied site to an unoccupied site). Snowy plover site occupancy and colonization was negatively associated with human disturbance and site extinction was positively associated with human disturbance. Interdune vegetation had a negative effect on occupancy and colonization, indicating that plovers were less likely to use areas with uniform, dense vegetation among dunes. Also, dune shape, beach debris, and access to low-energy foraging areas influenced site occupancy, colonization, and extinction. Plovers used habitat based on beach characteristics that provided stage-specific resource needs; however, human disturbance was the strongest predictor of site occupancy. In addition, vegetation plantings used to enhance dune rehabilitation may negatively impact plover site occupancy. Management actions that decrease human disturbance, such as symbolic fencing and signage, may increase the amount of breeding habitat available to snowy plovers on the Florida Panhandle and in other areas with high human activity. The specific areas that require this protection may vary across snowy plover life history stages. PMID:23610630
Webber, Alyson F; Heath, Julie A; Fischer, Richard A
Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2010
This report describes the 2010 research conducted under the U.S. Army Corps of Engineers (USACE) project EST-P-09-1, titled Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, and known as the 'Salmon Benefits' study. The primary goal of the study is to establish scientific methods to quantify habitat restoration benefits to listed salmon and trout in the lower Columbia River and estuary (LCRE) in three required areas: habitat connectivity, early life history diversity, and survival (Figure ES.1). The general study approach was to first evaluate the state of the science regarding the ability to quantify benefits to listed salmon and trout from habitat restoration actions in the LCRE in the 2009 project year, and then, if feasible, in subsequent project years to develop quantitative indices of habitat connectivity, early life history diversity, and survival. Based on the 2009 literature review, the following definitions are used in this study. Habitat connectivity is defined as a landscape descriptor concerning the ability of organisms to move among habitat patches, including the spatial arrangement of habitats (structural connectivity) and how the perception and behavior of salmon affect the potential for movement among habitats (functional connectivity). Life history is defined as the combination of traits exhibited by an organism throughout its life cycle, and for the purposes of this investigation, a life history strategy refers to the body size and temporal patterns of estuarine usage exhibited by migrating juvenile salmon. Survival is defined as the probability of fish remaining alive over a defined amount of space and/or time. The objectives of the 4-year study are as follows: (1) develop and test a quantitative index of juvenile salmon habitat connectivity in the LCRE incorporating structural, functional, and hydrologic components; (2) develop and test a quantitative index of the early life history diversity of juvenile salmon in the LCRE; (3) assess and, if feasible, develop and test a quantitative index of the survival benefits of tidal wetland habitat restoration (hydrologic reconnection) in the LCRE; and (4) synthesize the results of investigations into the indices for habitat connectivity, early life history diversity, and survival benefits.
Diefenderfer, Heida L.; Johnson, Gary E.; Sather, Nichole K.; Skalski, J. R.; Dawley, Earl M.; Coleman, Andre M.; Ostrand, Kenneth G.; Hanson, Kyle C.; Woodruff, Dana L.; Donley, Erin E.; Ke, Yinghai; Buenau, Kate E.; Bryson, Amanda J.; Townsend, Richard L.
Life history comparison of two terrestrial isopods in relation to habitat specialization
NASA Astrophysics Data System (ADS)
For many animal species, there is a relationship between life history strategies, as predicted by the r- K-selection theory, degree of habitat specialization and response to habitat alteration and loss. Here we compare two sympatric woodlice species with contrasting patterns of habitat use and geographical distribution. We predict that Atlantoscia floridana (Philosciidae), considered a habitat generalist, would exhibit the r-selected traits, whereas Balloniscus glaber (Balloniscidae), considered a habitat specialist, should have the K-selected traits. We analyzed several life history traits as well as life and fecundity tables using 715 and 842 females of A. floridana and B. glaber, respectively, from populations living in syntopy in southern Brazil. As predicted, most evaluated traits allow A. floridana to be considered an r-strategist and B. glaber a K-strategist: A. floridana showed a shorter lifetime, faster development, earlier reproduction, a smaller parental investment, higher net reproductive rate ( R0), a higher growth rate ( r) and a shorter generation time ( T) in comparison to B. glaber. A. floridana seems to be a successful colonizer with a high reproductive output. These characteristics explain its local abundance, commonness and wide geographical distribution. On the contrary, B. glaber has a restricted geographical distribution that is mainly associated with Atlantic forest fragments, a biome threatened by deforestation and replacement by monocultures. Its narrow distribution combined with the K-selected traits may confer to this species an increased extinction risk.
Quadros, Aline Ferreira; Caubet, Yves; Araujo, Paula Beatriz
Habitat and life history are critical elements in assessing the production dynamics of invertebrates and their role in aquatic ecosystems. We studied invertebrate productivity at two sites in a subtropical blackwater river (the Satilla) in the Lower Coastal Plain of Georgia, USA, and found that submerged wooden substrates, or snags, are heavily colonized by aquatic insects. We compared invertebrate productivity
Mars extant-life campaign using an approach based on Earth-analog habitats
NASA Technical Reports Server (NTRS)
The Mars Robotic Outpost group at JPL has identified sixteen potential momentous discoveries that if found on Mars would alter planning for the future Mars exploration program. This paper details one possible approach to the discovery of and response to the 'momentous discovery'' of extant life on Mars. The approach detailed in this paper, the Mars Extant-Life (MEL) campaign, is a comprehensive and flexible program to find living organisms on Mars by studying Earth-analog habitats of extremophile communities.
Palkovic, Lawrence A.; Wilson, Thomas J.
Geologic influences on Apache trout habitat in the White Mountains of Arizona
Geologic variation has important influences on habitat quality for species of concern, but it can be difficult to evaluate due to subtle variations, complex terminology, and inadequate maps. To better understand habitat of the Apache trout (Onchorhynchus apache or O. gilae apache Miller), a threatened endemic species of the White Mountains of east- central Arizona, we reviewed existing geologic research
Jonathan W. Long; Alvin L. Medina; Aregai Tecle
Food Availability and Tiger Shark Predation Risk Influence Bottlenose Dolphin Habitat Use
Although both food availability and predation risk have been hypothesized to affect dolphin habitat use and group size, no study has measured both factors concurrently to determine their relative influences. From 1997 to 1999, we investigated the effect of food availability and tiger shark (Galeocerdo cuvier) predation risk on bottlenose dolphin (Tursiops aduncus) habitat use and group size in Shark
Michael R. Heithaus; Lawrence M. Dill
Influence of Well Pad Activity on Winter Habitat Selection Patterns of Mule Deer
Conversion of native winter range into producing gas fields can affect the habitat selection and distribution patterns of mule deer (Odocoileus hemionus). Understanding how levels of human activity influence mule deer is necessary to evaluate mitigation measures and reduce indirect habitat loss to mule deer on winter ranges with natural gas development. We examined how 3 types of well pads
Hall Sawyer; Matthew J. Kauffman; Ryan M. Nielson
Species diversity and persistence in restored and remnant tallgrass prairies of North America: a function of species' life history, habitat type, or sampling bias?
1. The re-assembly of native animal communities in restored landscapes is a relatively unexplored phenomenon for many taxa. Specifically, ecologists lack the ability to generalize about how species traits, habitat size, habitat type (here, remnant prairie vs. restored grassland), and temporal variation interact to affect species diversity or species' persistence probabilities. 2. To investigate these relationships, moth communities from 10 prairie remnants and restorations were sampled over a 3-year interval and a combination of NMDS ordination, logistic regression, and repeated measures anova were used to test hypotheses regarding how life history variables and habitat characteristics determine the degree to which restored habitats develop a moth fauna similar to remnants. 3. Within sampling years, restored tallgrass prairies that were >or= 7 years old possessed lepidopteran species assemblages that were generally similar to those in prairie remnants. Community similarity, however, was driven by common moth species likely to also occur in the surrounding agricultural habitat. Species persistence was significantly influenced by a series of trait combinations identified using principal components analysis. Temporal variation independent of habitat type or patch size was the most significant determination of variation in species composition among sites. 4. These results suggest that lepidopteran persistence in restored landscapes is at least partially determined by species' life history attributes. The correlation between sampling year and species richness suggests that both weather effects on species voltinism and interannual differences in sampling bias may make it difficult for land managers to detect changes in species abundance following disturbance or habitat management. 5. Species may not necessarily possess specific life history traits that reduce extinction risk or enhance recolonization probabilities in the highly modified agricultural landscape of the Midwestern USA. Rather, voltinism, fecundity, body size, and host plant specialization may influence the ability of species to maintain populations in the greater agricultural landscape or to escape mass mortality following disturbances imposed by prairie management. PMID:18284475
Summerville, Keith S
The search for life on Europa: limiting environmental factors, potential habitats, and Earth analogues.
The putative ocean of Europa has focused considerable attention on the potential habitats for life on Europa. By generally clement Earth standards, these Europan habitats are likely to be extreme environments. The objectives of this paper were to examine: (1) the limits for biological activity on Earth with respect to temperature, salinity, acidity, desiccation, radiation, pressure, and time; (2) potential habitats for life on Europa; and (3) Earth analogues and their limitations for Europa. Based on empirical evidence, the limits for biological activity on Earth are: (1) the temperature range is from 253 to 394 K; (2) the salinity range is a(H2O) = 0.6-1.0; (3) the desiccation range is from 60% to 100% relative humidity; (4) the acidity range is from pH 0 to 13; (5) microbes such as Deinococcus are roughly 4,000 times more resistant to ionizing radiation than humans; (6) the range for hydrostatic pressure is from 0 to 1,100 bars; and (7) the maximum time for organisms to survive in the dormant state may be as long as 250 million years. The potential habitats for life on Europa are the ice layer, the brine ocean, and the seafloor environment. The dual stresses of lethal radiation and low temperatures on or near the icy surface of Europa preclude the possibility of biological activity anywhere near the surface. Only at the base of the ice layer could one expect to find the suitable temperatures and liquid water that are necessary for life. An ice layer turnover time of 10 million years is probably rapid enough for preserving in the surface ice layers dormant life forms originating from the ocean. Model simulations demonstrate that hypothetical oceans could exist on Europa that are too cold for biological activity (T < 253 K). These simulations also demonstrate that salinities are high, which would restrict life to extreme halophiles. An acidic ocean (if present) could also potentially limit life. Pressure, per se, is unlikely to directly limit life on Europa. But indirectly, pressure plays an important role in controlling the chemical environments for life. Deep ocean basins such as the Mariana Trench are good analogues for the cold, high-pressure ocean of Europa. Many of the best terrestrial analogues for potential Europan habitats are in the Arctic and Antarctica. The six factors likely to be most important in defining the environments for life on Europa and the focus for future work are liquid water, energy, nutrients, low temperatures, salinity, and high pressures. PMID:14987483
Marion, Giles M; Fritsen, Christian H; Eicken, Hajo; Payne, Meredith C
An Evaluation of the Relative Influence of Habitat Complexity and Habitat Stability on Fish Assemblage Structure in Unregulated and Regulated Reaches of a Large Southeastern Warmwater Stream
River regulation and development are the foremost problems threatening lotic fishes and other aquatic biota in the United States. The operation of hydroelectric facilities can influence both habitat availability and environmental stability in downstream reaches. We evaluated the relative influence of habitat complexity and environmental stability on fish assemblage structure at unregulated and hydropower-regulated reaches of the Flint River in
Colin P. Shea; James T. Peterson
Life support systems and optimal isotope composition in cosmonaut habitats for long-term missions
NASA Astrophysics Data System (ADS)
Differences in the isotope content of the biogenous chemicals of cosmonaut habitats are given a theoretical consideration. Rationale is given to the hypothesis according to which the biochemical and biophysical processes in plants, animals, and humans must be impacted by the isotopes of all the biogenous chemicals in cosmonaut habitats. Organisms were found to persistently make preference of lighter fractions of stable isotopes from the biogenous chemicals. In most of the compounds the light fraction of stable isotopes constitutes the greater portion by mass. However, the optimal isotope composition of biogenous chemicals is still unknown and necessitates biochemical, toxicological, biological and other kinds of research. The functions of a life support system should also include production and maintenance of an optimal isotope composition for habitats, i.e. water, oxygen, food stuffs in order to improve metabolism in and performance of cosmonauts.
Siniak, I. E.; Grigoriev, A. I.
Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary, Annual Report 2009
This report describes the 2009 research conducted under the U.S. Army Corps of Engineers (USACE or Corps) project EST-09-P-01, titled Evaluation of Life History Diversity, Habitat Connectivity, and Survival Benefits Associated with Habitat Restoration Actions in the Lower Columbia River and Estuary. The research was conducted by the Pacific Northwest National Laboratory, Marine Science Laboratory and Hydrology Group, in partnership
Heida L. Diefenderfer; Gary E. Johnson; Nichole K. Sather; John R. Skalski; Earl M. Dawley; Andre M. Coleman
Habitat productivity influences root mass vertical distribution in grazed Mediterranean ecosystems
NASA Astrophysics Data System (ADS)
Herbivores are expected to influence grassland ecosystems by modifying root biomass and root spatial distribution of plant communities. Studies in perennial dominated grasslands suggest that grazing intensity and primary productivity may be strong determinants of the vertical distribution of subterranean biomass. However, no studies have addressed this question in annual dominated pastures. In this study we assess the effect of grazing and habitat productivity on the vertical distribution of root mass in an annual dominated Mediterranean pasture grazed by free-ranging sheep and wild rabbits. We evaluate the effects of grazing on total root mass and vertical root distribution (0-4, 4-8 and 8-12 cm depths) in two neighboring topographic sites (uplands and lowlands) with different productivity using a replicated fence experiment which excludes sheep and sheep plus rabbits. We found evidences that grazing affected root biomass and vertical distribution at lowlands (high productivity habitats), where places grazed by sheep plus rabbits exhibit more root mass and a higher concentration of it towards the soil surface than only rabbits and ungrazed places. In contrast, grazing did not affect root biomass and vertical distribution at uplands (low productivity habitats). We suggest that higher nitrogen and organic matter found in lowlands permit a plant adjustment for nitrogen acquisition by increasing biomass allocation to root production which would allow plant regrowth and the quick completion of the annual life cycle. Contrary, soil resources scarcity at uplands do not permit plants modify their root growth patterns in response to grazing. Our study emphasizes the importance of primary productivity in predicting grazing effect on belowground processes in Mediterranean environments dominated by annuals.
Rueda, Marta; Rebollo, Salvador; RodrÚguez, Miguel ê.
Habitat and distribution of post-recruit life stages of the squid Loligo forbesii
NASA Astrophysics Data System (ADS)
This study models habitat preferences of the squid Loligo forbesii through its post-recruitment life cycle in waters around Scotland (UK). Trawl survey and market sample data from 1985 to 2004 are used to model seasonal habitats of immature, maturing and mature squid (maturity being inferred from size and season). Squid presence-absence and catch rate in areas of presence were analysed using generalised additive models, relating spatiotemporal patterns of distribution and abundance to ecogeographic variables. For all maturity classes, higher abundance in winter and spring (i.e., quarters 1 and 2) was associated with deeper water while higher abundance in summer and autumn (quarters 3 and 4) was associated with shallower water, consistent with seasonal onshore-offshore migrations but suggesting that most spawning may take place in deeper waters. The preferred SST range was generally 8-8.75 ¯C while preferred salinity values were below 35 in winter and summer and above 35 in spring and autumn. Squid were positively associated with gravel substrate and negatively associated with mud. Seasonal changes in habitat use were more clearly evident than changes related to inferred maturity, although the two effects cannot be fully separated due to the annual life cycle. Habitat selection for this species can be satisfactorily modelled on a seasonal basis; predictions based on such models could be useful for fishers to target the species more effectively, and could assist managers wishing to protect spawning grounds. The extent to which this approach may be useful for other cephalopods is discussed.
Smith, Jennifer M.; Macleod, Colin D.; Valavanis, Vasilis; Hastie, Lee; Valinassab, Tooraj; Bailey, Nick; Santos, M. Begoþa; Pierce, Graham J.
Shifting the life-history paradigm: discovery of novel habitat use by hawksbill turtles
Adult hawksbill turtles (Eretmochelys imbricata) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species. Our findings highlight the variability in life-history strategies that marine turtles and other wide-ranging marine wildlife may exhibit among ocean regions, and the importance of understanding such disparities from an ecological and management perspective.
Gaos, Alexander R.; Lewison, Rebecca L.; Yanez, Ingrid L.; Wallace, Bryan P.; Liles, Michael J.; Nichols, Wallace J.; Baquero, Andres; Hasbun, Carlos R.; Vasquez, Mauricio; Urteaga, Jose; Seminoff, Jeffrey A.
Environmental control and life support system selection for the first Lunar outpost habitat
NASA Technical Reports Server (NTRS)
The planning for and feasibility study of an early human return mission to the lunar surface has been undertaken. The First Lunar Outpost (FLO) Mission philosophy is to use existing or near-term technology to achieve a human landing on the lunar surface in the year 2000. To support the crew the lunar habitat for the FLO mission incorporates an environmental control/life support system (ECLSS) design which meets the mission requirements and balances fixed mass and consumable mass. This tradeoff becomes one of regenerable life support systems versus open-loop systems.
Adams, Alan
Accessible habitat for shorebirds: Factors influencing its availability and conservation implications
We examined the relationship between water levels and accessible habitat, and how accessible habitat influenced Dunlin (Calidris alpina) and Semipalmated Sandpiper (Calidris pusilla) numbers in managed wetlands at Pea Island (North Carolina) and Merritt Island (Florida) National Wildlife Refuges in 1998 and 1999. At Pea Island we experimentally manipulated water levels, which also allowed us to examine the effects of water level fluctuations on prey base. We examined these relationships because access to foraging habitat by shorebirds is positively related to the length of their tarsometatarsus, and in the southeastern United States, small calidrids are a numerically important component of the two million migrants using inland and managed wetlands. We confirmed the importance of shallow waters for Dunlin and Semipalmated Sandpiper-numbers increased with increasing availability of 0-4 cm habitat. At Merritt Island, Dunlin use was inversely related to variability in water depth of 0-4 cm. Minimizing the frequency and amplitude of water level fluctuations associated with single-capped culverts is necessary to improve habitat quality. After adjusting for accessibility, spring habitat requirements for Dunlin and Semipalmated Sandpiper at Pea Island were met under nearly all abundance scenarios. We identified water level targets that maximize accessible habitat at Pea Island. In contrast, winter habitat requirements for Dunlin at Merritt Island were not met except in one scenario. Seasonally low prey density contributed to the shortfall, suggesting that allocating more habitat is the primary management option. Manipulating water levels at Pea Island did not adversely affect the density of eight shorebird prey species. Estimates of accessible habitat and other parameters (e.g., turnover rates, prey biomass) are essential to set and implement realistic shorebird habitat conservation goals.
Collazo, J. A.; O'Harra, D. A.; Kelly, C. A.
Life-history variation following habitat degradation associated with differing fine-scale spatial genetic structure in a rainforest cycad
Habitat degradation can result in drastic environmental changes potentially affecting the life-history of populations and\\u000a aspects of the reproductive biology and the genetic structure within and among populations. Here, we explore how life-history\\u000a differences between subpopulations from contrasting habitats may affect mating availability, which in turn will indirectly\\u000a affect the strength of spatial genetic structure within populations of a tropical
Cristina Lopez-Gallego; Pamela ONeil
Short-Term Influence of Tank Tracks on Vegetation and Microphytic Crusts in Shrubsteppe Habitat
Artemisia tridentata Nutt.) habitat within the Idaho Army National Guard Orchard Training Area in southwestern Idaho. The purpose of this study\\u000a was to determine the short-term (12 years) influence of tank tracks on vegetation and microphytic crusts in shrubsteppe habitat.\\u000a The two types of tank tracks studied were divots (area where one track has been stopped or slowed to make
Stephen E. Watts
The influence of habitat provisioning: use of earthworm burrows by the terrestrial salamander, Plethodon cinereus
Studies examining the influence of habitat provisioning by one species on the behavior of other species can provide key insights\\u000a regarding impacts of ecosystem engineers on the availability of resources to other species. More specifically, an organisms\\u000a use of additional habitat provided by ecosystem engineers may affect the interpretation of observational or demographic data.\\u000a We chose to examine the possible
Rita I. CÃceres-Charneco; Tami S. Ransom
The relative influence of nutrients and habitat on stream metabolism in agricultural streams
Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the\\u000a USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration\\u000a (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was\\u000a an assessment of habitat in the
Jill D. Frankforter; Holly S. Weyers; Jerad D. Bales; Patrick W. Moran; Daniel L. Calhoun
Influence of habitat amount, arrangement, and use on population trend estimates of male Kirtland's warblers
Kirtland's warblers (Dendroica kirtlandii) persist in a naturally patchy environment of young, regenerating jack pine forests (i.e., 5-23 years old) created after wildfires and human logging activities. We examined how changing landscape structure from 26 years of forest management and wildfire disturbances influenced population size and spatial dispersion of male Kirtland's warblers within their restricted breeding range in northern Lower Michigan, USA. The male Kirtland's warbler population was six times larger in 2004 (1,322) compared to 1979 (205); the change was nonlinear with 1987 and 1994 identified as significant points of change. In 1987, the population trend began increasing after a slowly declining trend prior to 1987, and the rate of increase appeared to slow after 1994. Total amount of suitable habitat and the relative area of wildfire-regenerated habitat were the most important factors explaining population trend. Suitable habitat increased 149% primarily due to increasing plantations from forest management. The relative amount and location of wildfire-regenerated habitat modified the distribution of males among various habitat types, and the spatial variation in their abundance across the primary breeding range. These findings indicate that the Kirtland's warbler male population shifted its use of habitat types temporally and spatially as the population increased and as the relative availability of habitats changed through time. We demonstrate that researchers and managers need to consider not only habitat quality, but the temporal and the spatial context of habitat availability and population levels when making habitat restoration decisions. ?? 2008 Springer Science+Business Media B.V.
Donner, D. M.; Probst, J. R.; Ribic, C. A.
Short-term influence of tank tracks on vegetation and microphytic crusts in shrubsteppe habitat
Artemisia tridentata Nutt.) habitat within the Idaho Army National Guard Orchard Training Area in southwestern Idaho. The purpose of this study was to determine the short-term (1a??2 years) influence of tank tracks on vegetation and microphytic crusts in shrubsteppe habitat. The two types of tank tracks studied were divots (area where one track has been stopped or slowed to make a sharp turn) and straight-line tracks. Divots generally had a stronger influence on vegetation and microphytic crusts than did straight-line tracks. Tank tracks increased cover of bare ground, litter, and exotic annuals, and reduced cover of vegetation, perennial native grasses, sagebrush, and microphytic crusts. Increased bare ground and reduced cover of vegetation and microphytic crusts caused by tank tracks increase the potential for soil erosion and may reduce ecosystem productivity. Reduced sagebrush cover caused by tank tracks may reduce habitat quality for rodents. Tank tracks may also facilitate the invasion of exotic annuals into sagebrush habitat, increasing the potential for wildfire and subsequent habitat degradation. Thus, creation of divots and movement through sagebrush habitat by tanks should be minimized.
Watts, Stephen E.
Short-Term Influence of Tank Tracks on Vegetation and Microphytic Crusts in Shrubsteppe Habitat
/ I examined vegetation and microphytic crust cover on two sites in burned and two sites in unburned big sagebrush (Artemisia tridentata Nutt.) habitat within the Idaho Army National Guard Orchard Training Area in southwestern Idaho. The purpose of this study was to determine the short-term (1-2 years) influence of tank tracks on vegetation and microphytic crusts in shrubsteppe habitat. The two types of tank tracks studied were divots (area where one track has been stopped or slowed to make a sharp turn) and straight-line tracks. Divots generally had a stronger influence on vegetation and microphytic crusts than did straight-line tracks. Tank tracks increased cover of bare ground, litter, and exotic annuals, and reduced cover of vegetation, perennial native grasses, sagebrush, and microphytic crusts. Increased bare ground and reduced cover of vegetation and microphytic crusts caused by tank tracks increase the potential for soil erosion and may reduce ecosystem productivity. Reduced sagebrush cover caused by tank tracks may reduce habitat quality for rodents. Tank tracks may also facilitate the invasion of exotic annuals into sagebrush habitat, increasing the potential for wildfire and subsequent habitat degradation. Thus, creation of divots and movement through sagebrush habitat by tanks should be minimized.KEY WORDS: Divots; Fire history; Idaho; Military; Sagebrush; Straight-line tracks PMID:9582396
Local Abundance Patterns of Noctuid Moths in Olive Orchards: Life-History Traits, Distribution Type and Habitat Interactions
Local species abundance is related to range size, habitat characteristics, distribution type, body size, and life-history variables. In general, habitat generalists and polyphagous species are more abundant in broad geographical areas. Underlying this, local abundance may be explained from the interactions between life-history traits, chorological pattern, and the local habitat characteristics. The relationship within taxa between life-history traits, distribution area, habitat characteristics, and local abundance of the noctuid moth (Lepidoptera: Noctuidae) assemblage in an olive orchard, one of the most important agro-ecosystems in the Mediterranean basin, was analyzed. A total of 66 species were detected over three years of year-round weekly samplings using the light-trap method. The life-history traits examined and the distribution type were found to be related to the habitat-species association, but none of the biological strategies defined from the association to the different habitats were linked with abundance. In contrast to general patterns, dispersal ability and number of generations per year explained differences in abundance. The relationships were positive, with opportunistic taxa that have high mobility and several generations being locally more abundant. In addition, when the effect of migrant species was removed, the distribution type explained abundance differences, with Mediterranean taxa (whose baricenter is closer to the studied area) being more abundant.
Perez-Guerrero, Sergio; Redondo, Alberto Jose; Yela, Jose Luis
Habitat differentiation in the early life stages of simultaneously mass-spawning corals
NASA Astrophysics Data System (ADS)
The settlement process of coral larvae following simultaneous mass-spawning remains poorly understood, particularly in terms of population and community parameters. Here, the larval settlement patterns of Acropora corals, which are the most diverse genera of scleractinian corals at the species (haplotype) level, were investigated within a single subtropical reef. Across a 4-year period (2007-2010), the mitochondrial and nuclear molecular markers of 1,073 larval settlers were analyzed. Of the 11 dominant haplotypes of recruited populations, nine exhibited non-random patterns of settlement distribution. This result suggests that the actual habitat segregation starts during the early swimming larval stages of their life history, rather than by natural selection after random settlement. In addition, the presence of a depth-related settlement pattern supports that species-specific vertical zonation of coral larvae may play a role in the establishment of habitat segregation. Moreover, in some species that showed a preference toward the shoreward area of the bay, the settlement pattern was consistent with that of the adult distribution. This result indicates that the gametes were not mixed between fore and back reefs in the period from fertilization to settlement during the mass-spawning event, even within a single small reef. Another compatible hypothesis of this pattern is that the larvae are able to recognize various types of environmental information, facilitating the selection of optimal micro-habitats. Overall, Acropora coral larvae that are produced from a simultaneous mass-spawning event may have adapted to complex reef topography by means of multi-step habitat selection at settlement, corresponding to different spatial scales.
Suzuki, G.; Arakaki, S.; Kai, S.; Hayashibara, T.
Research planning criteria for regenerative life-support systems applicable to space habitats
NASA Technical Reports Server (NTRS)
The second phase of analyses that were conducted by the Life Support Systems Group of the 1977 NASA Ames Summer Study is described. This phase of analyses included a preliminary review of relevant areas of technology that can contribute to the development of closed life-support systems for space habitats, the identification of research options in these areas of technology, and the development of guidelines for an effective research program. The areas of technology that were studied included: (1) nutrition, diet, and food processing; (2) higher plant agriculture; (3) animal agriculture; (4) waste conversion and resource recovery; and (5) system stability and safety. Results of these analyses, including recommended research options and criteria for establishing research priorities among these many options, are discussed.
Spurlock, J.; Cooper, W.; Deal, P.; Harlan, A.; Karel, M.; Modell, M.; Moe, P.; Phillips, J.; Putnam, D.; Quattrone, P.
Influence of plumage colour on prey response: does habitat alter heron crypsis to prey?
The foraging strategies of wading birds may be influenced by their degree of crypsis to aquatic prey. White plumage has been hypothesized to be adaptive for herons hunting in open water habitats. We tested this hypothesis with laboratory and field experiments with multiple prey species. We investigated the response of crayfish, Procambarus spp., and mosquitofish, Gambusia affinis, to white- and
M. Clay Green; Paul L. Leberg
Endothermy in African Platypleurine Cicadas: The Influence of Body Size and Habitat (Hemiptera: Cicadidae)
The platypleurine cicadas have a wide distribution acrossAfrica and southern Asia. We investigate endothermy as a thermo- regulatory strategy in 11 South African species from fivegenera, with comparisons to the lone ectothermic platypleurine we found, in an attempt to ascertain any influence that habitat and\\/or body size have on the expression of endothermy in the platypleurine cicadas. Field measurements of
Allen F. Sanborn; Martin H. Villet; Polly K. Phillips
Understanding factors that influence and predict grizzly bear (Ursus arctos) distribution and abundance is fundamental to their conservation. In southeast British Columbia, Canada, we applied DNA hair-trap sampling (1) to evaluate relationships of grizzly bear detections with landscape variables of habitat and human activity, and (2) to model the spatial distribution and abundance of grizzly bears. During 1996-1998, we sampled
CLAYTON D. APPS; BRUCE N. McLELLAN; JOHN G. WOODS; MICHAEL F. PROCTOR; Gehrt
MWSA's physical habitat approach - combining knowledge of habitat requirements with mechanisms of geomorphic and anthropogenic influence on stream channel form
Effective environmental policy decisions benefit from stream habitat information that is accurate, precise, and relevant. The recent National Wadeable Streams Assessment (NWSA) carried out by the U.S. EPA required physical habitat information sufficiently comprehensive to facilit...
Swamp rabbits in floodplain ecosystems: Influence of landscape- and stand-level habitat on relative abundance
Swamp rabbits (Sylvilagus aquaticus) are bottomland hardwood forest specialists that may serve as useful indicators of ecosystem health. However, no studies\\u000a have assessed the influence of both microhabitat and macrohabitat variables on relative abundance of swamp rabbits. To address\\u000a this gap in the literature, we assessed the influence of landscape- and stand-level habitat variables on relative abundance\\u000a of swamp rabbits
Paul D. Scharine; Clayton K. Nielsen; Eric M. Schauber; Lyann Rubert
Does habitat or depth influence catch rates of pelagic species?
The efficiency of a pelagic longline fishing operation and the species composition of the resulting catch is influenced primarily by the relationship between the distribution of hooks and species vulnerability, with vulnerability described by either depth or some suite of environmental variables. We therefore fitted longline catch rate models to determine whether catch is estimated better by vertically distributing a
Keith A. Bigelow; Mark N. Maunder
Virtual Habitat -a dynamic simulation of closed life support systems -human model status
NASA Astrophysics Data System (ADS)
In order to optimize Life Support Systems on a system level, stability questions must be in-vestigated. To do so the exploration group of the Technical University of Munich (TUM) is developing the "Virtual Habitat" (V-HAB) dynamic LSS simulation software. V-HAB shall provide the possibility to conduct dynamic simulations of entire mission scenarios for any given LSS configuration. The Virtual Habitat simulation tool consists of four main modules: Closed Environment Module (CEM) -monitoring of compounds in a closed environment Crew Module (CM) -dynamic human simulation P/C Systems Module (PCSM) -dynamic P/C subsystems Plant Module (PM) -dynamic plant simulation The core module of the simulation is the dynamic and environment sensitive human module. Introduced in its basic version in 2008, the human module has been significantly updated since, increasing its capabilities and maturity significantly. In this paper three newly added human model subsystems (thermal regulation, digestion and schedule controller) are introduced touching also on the human stress subsystem which is cur-rently under development. Upon the introduction of these new subsystems, the integration of these into the overall V-HAB human model is discussed, highlighting the impact on the most important I/F. The overall human model capabilities shall further be summarized and presented based on meaningful test cases. In addition to the presentation of the results, the correlation strategy for the Virtual Habitat human model shall be introduced assessing the models current confidence level and giving an outlook on the future correlation strategy. Last but not least, the remaining V-HAB mod-ules shall be introduced shortly showing how the human model is integrated into the overall simulation.
Markus Czupalla, M. Sc.; Zhukov, Anton; Hwang, Su-Au; Schnaitmann, Jonas
Influence of learning on range expansion and adaptation to novel habitats
Learning has been postulated to drive evolution, but its influence on adaptive evolution in heterogeneous environments has not been formally examined. We used a spatially explicit individual-based model to study the effect of learning on the expansion and adaptation of a species to a novel habitat. Fitness was mediated by a behavioural trait (resource preference), which in turn was determined by both the genotype and learning. Our findings indicate that learning substantially increases the range of parameters under which the species expands and adapts to the novel habitat, particularly if the two habitats are separated by a sharp ecotone (rather than a gradient). However, for a broad range of parameters, learning reduces the degree of genetically-based local adaptation following the expansion and facilitates maintenance of genetic variation within local populations. Thus, in heterogeneous environments learning may facilitate evolutionary range expansions and maintenance of the potential of local populations to respond to subsequent environmental changes.
Transitions during cephalopod life history: the role of habitat, environment, functional morphology and behaviour.
Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from the female (1), from eggs to paralarvae (2), from paralarvae to subadults (3) and from subadults to adults (4). An analysis of each transition identified that the changes can be radical (i.e. involving a range of morphological, physiological and behavioural phenomena and shifts in habitats) and critical (i.e. depending on environmental conditions essential for cohort survival). This analysis underlines that transitions from eggs to paralarvae (2) and from paralarvae to subadults (3) present major risk of mortality, while changes in the other transitions can have evolutionary significance. This synthesis suggests that more accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development and ecology in this particular group. PMID:24880797
Robin, Jean-Paul; Roberts, Michael; Zeidberg, Lou; Bloor, Isobel; Rodriguez, Almendra; Briceþo, Felipe; Downey, Nicola; Mascarµ, Maite; Navarro, Mike; Guerra, Angel; Hofmeister, Jennifer; Barcellos, Diogo D; LourenÓo, Silvia A P; Roper, Clyde F E; Moltschaniwskyj, Natalie A; Green, Corey P; Mather, Jennifer
Predation and infanticide influence ideal free choice by a parrot occupying heterogeneous tropical habitats
The ideal free distribution (IFD) predicts that organisms will disperse to sites that maximize their fitness based on availability of resources. Habitat heterogeneity underlies resource variation and influences spatial variation in demography and the distribution of populations. We relate nest site productivity at multiple scales measured over a decade to habitat quality in a box-nesting population of Forpus passerinus (green-rumped parrotlets) in Venezuela to examine critical IFD assumptions. Variation in reproductive success at the local population and neighborhood scales had a much larger influence on productivity (fledglings per nest box per year) than nest site or female identity. Habitat features were reliable cues of nest site quality. Nest sites with less vegetative cover produced greater numbers of fledglings than sites with more cover. However, there was also a competitive cost to nesting in high-quality, low-vegetative cover nest boxes, as these sites experienced the most infanticide events. In the lowland local population, water depth and cover surrounding nest sites were related with F. passerinus productivity. Low vegetative cover and deeper water were associated with lower predation rates, suggesting that predation could be a primary factor driving habitat selection patterns. Parrotlets also demonstrated directional dispersal. Pairs that changed nest sites were more likely to disperse from poor-quality nest sites to high-quality nest sites rather than vice versa, and juveniles were more likely to disperse to, or remain in, the more productive of the two local populations. Parrotlets exhibited three characteristics fundamental to the IFD: habitat heterogeneity within and between local populations, reliable habitat cues to productivity, and active dispersal to sites of higher fitness.
Beissinger, Steven R.
Mangrove habitat partitioning by Ucides cordatus (Ucididae): effects of the degree of tidal flooding and tree-species composition during its life cycle
NASA Astrophysics Data System (ADS)
Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs' life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season.
Wunderlich, A. C.; Pinheiro, M. A. A.
Dress Warm, Focus on the Fluids and Be Patient: Studying Ice Habitats and Constraints on Microbial Life at Low Temperatures
Studies of low-temperature environments on Earth can help guide exploration of other planetary environments that are of interest in the search for potential traces of life (or absence thereof) elsewhere in the solar system. Ice environments and habitats on Earth range from terrestrial permafrost to the polar ice caps or floating sea and lake ice. Despite the complexity of these
H. Eicken; K. Junge; J. Deming
Influence of Habitat Modifications on Habitat Composition and Anadromous Salmonid Populations in Fish Creek, Oregon, 1983-1988 Annual Report.
Modification of degraded habitats to increase populations of anadromous salmonids is a major focus of management agencies throughout the Pacific Northwest. Millions of dollars are spent annually on such efforts. Inherent in implementing habitat improvements is the need for quantitative evaluation of the biological and physical effects of such work. Reeves et al. (in press), however, noted that such evaluations are rare, making it difficult to assess the true results of habitat work. While it is not economically possible to thoroughly evaluate every habitat project, it is essential that intensive evaluations be done on selected representative projects. One such evaluation program has been underway since 1982 on Fish Creek, a tributary of the Clackamas River near Estacada, OR. Habitat modification has been done by the USDA Forest Service, Estacada Ranger District, Mt. Hood National Forest with funding provided in part by the Bonneville Power Administration (BPA). The USDA Forest Service, Anadromous Fish Habitat Research Unit, Pacific Northwest Research Station (PNW), Corvallis, OR is charged with: (1) evaluating the biological and physical responses to habitat modifications on a basin scale; and (2) developing a cost-benefit analysis of the program. Preliminary results have been reported in a series of annual publications, Everest and Sedell 1983, 1984 and Everest et al. 1985, 1986, 1987, 1988. The objectives of this paper are to: (1) report 1988 observations of biological and physical changes in habitat, salmonid populations, and smolt production in Fish Creek, and (2) examine preliminary trends in fish habitat and populations related to habitat improvement over the period 1983-1988. We have prefaced the trends in the latter objective as preliminary because we believe it could take a minimum of 10 years before the full biological and physical responses to habitat work are realized. We therefore urge caution in interpreting these preliminary results.
Reeves, Gordon H.; Everest, Fred H. (Oregon State University, Pacific Northwest Forest and Range Experiment Station, Corvallis, OR); Hohler, David B. (Mount Hood National Forest, Clackamas River Ranger District, Estacada, OR)
Factors Influencing Landowner Interest in Managing Wildlife and Avian Habitat on Private Forestland
This study examined factors related to private forest landowners' interest in managing wildlife and avian habitat on their land. Regression analysis of survey responses from Tennessee Cumberland Plateau landowners indicated that their interests were influenced by demographic factors (e.g., age) and forestland ownership characteristics (e.g., length of land tenure, ownership size). Landowners who had previously enrolled in a government cost-share
Neelam C. Poudyal; Donald G. Hodges
Effect of habitat preference on frond life span in three Cyathea tree ferns
NASA Astrophysics Data System (ADS)
It has been reported that plants living in various geographical areas had different physiological forms, as factors of microenvironment have strong impacts on physiological characters. However, the physiological characters of fronds have been scarcely reported in ferns. In this study, we investigated physiological differences in response to the habitat preference in the three tree ferns in northeast Taiwan, Cyathea lepifera, C. spinulosa, and C. podophylla, prefer to open site, edge of forest, and interior forest, respectively. The canopy openness above the individuals of C. lepifera, C. spinulosa and C. podophylla were 29.2 Ý 14.10 , 7.0 Ý 3.07 and 5.0 Ý 2.24 %, respectively. Among three species, C. podophylla had the longest frond life span (13.0 Ý 4.12 months) than the two others (C. lepifera (6.8 Ý 1.29 months) and C. spinulosa (7.3 Ý1.35 months). Our result supported the general patterns that shade intolerant species have a shorter leaf life span than shade tolerant species. The maximum net CO2 assimilation of C. lepifera, C. spinulosa and C. podophylla were 11.46 Ý 1.34, 8.27 Ý 0.69, and 6.34 Ý 0.54 ?mol CO2 m-2 s-1, respectively. As well, C. lepifera had the highest photosynthetic light saturation point (LSP), while C. podophylla had the lowest LSP among these three tree ferns. These suggested that C. lepifera could be more efficient for capturing and utilizing light resources under the larger canopy openness condition than the other two species. We also found that frond C : N ratio were positively correlated with frond life span among species. C. podophylla, with the longest frond life span, had the highest frond C : N ratio (22.17 Ý 1.95), which was followed by C. spinulosa (18.58 Ý 1.37) and C. lepifera (18.68 Ý 2.63) with shorter frond life span. The results were consistent to the theory that the fronds and leaves of shade intolerant species have high photosynthetic abilities with low C : N ratio. Key words: Canopy openness, frond life span, tree fern, Cyathea, frond C : N ratio
Chiu, Tzu Yun; Wang, Hsiang Hua; Lun Kuo, Yao; Kume, Tomonori
Virtual Habitat -a Dynamic Simulation of Closed Life Support Systems -Overall Status and Outlook
NASA Astrophysics Data System (ADS)
In order to optimize Life Support Systems (LSS) on a system level, stability questions and closure grade must be investigated. To do so the exploration group of the Technical University of Munich (TUM) is developing the "Virtual Habitat" (V-HAB) dynamic LSS simulation software. The main advantages of the dynamic simulation of LSS within V-HAB are the possibilities to compose different LSS configurations from the LSS subsystems and conduct dynamic simulation of it to test its stability in different mission scenarios inclusive emergency events and define the closure grade of the LSS. Additional the optimization of LSS based on different criteria will be possible. The Virtual Habitat simulation tool consists of four main modules: Closed Environment Module (CEM) -monitoring of compounds in a closed environment Crew Module (CM) -dynamic human simulation P/C Systems Module (PCSM) -dynamic P/C subsystems Plant Module (PM) -dynamic plant simulation Since the first idea and version, the V-HAB simulation has been significantly updated increasing its capabilities and maturity significantly. The updates which shall be introduced concern all modules of V-HAB. In particular: Significant progress has been made in development of the human model. In addition to the exist-ing human sub-models three newly developed ones (thermal regulation, digestion and schedule controller) have been introduced and shall be presented. Regarding the Plant Module a wheat plant model has been integrated in the V-HAB and is being correlated against test data. Ad-ditionally a first version of the algae bioreactor model has been developed and integrated. In terms of the P/C System module, an innovative approach for the P/C subsystem modelling has been developed and applied. The capabilities and features of the improved V-HAB models and the overall functionality of the V-HAB are demonstrated in form of meaningful test cases. In addition to the presentation of the results, the correlation strategy for the Virtual Habitat simulation shall be introduced assessing the models current confidence level and giving an outlook on the future correlation strategy.
Zhukov, Anton; Schnaitmann, Jonas; Mecsaci, Ahmad; Bickel, Thomas; Markus Czupalla, M. Sc.
Analysis of the Influence of Spatial Pattern in Habitat Selection Studies
Design and analysis of wildlife habitat selection studies typically do not assess the effect of spatial pattern on the habitat selection process. Effects of landscape scale pattern on habitat selection cannot be accomplished without replicate study areas, because pattern is a single, albeit multifaceted, attribute of an area. For a single area, however, the influence of pattern-related characteristics, such as shape and edge shared with adjacent patches, can be estimated by using GLIM (McCullough and Neider 1983) procedures to model patch-specific frequency counts of animal use as a function of these parameters. This approach is evaluated and illustrated with simulated breeding-bird counts in a South Carolina study area for which a GIS land cover classification is available. A related technique for evaluating whether movement from patch to patch is selective is developed and illustrated for designs that involve collection of trajectory data from monitored individuals. These designs and analyses are feasible given current GIS and GPS technology. Statistical inferences from habitat selection studies should be interpreted within the context of a range of scales at which animals differentiate between patch attributes.
Otis, D. L.
The relative influence of nutrients and habitat on stream metabolism in agricultural streams
Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was an assessment of habitat in the sampling reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r 2 = 0.79-0.91) and CR-24 (r 2 = 0.76-0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP. ?? 2009 The Author(s).
Frankforter, J. D.; Weyers, H. S.; Bales, J. D.; Moran, P. W.; Calhoun, D. L.
Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus
NASA Astrophysics Data System (ADS)
Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the F ST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species.
GonzÃlez-Wang■emert, Mercedes; Vergara-Chen, Carlos
Robotic Technologies for Surveying Habitats and Seeking Evidence of Life: Results from the 2004 Field Experiments of the "Life in the Atacama" Project
NASA Technical Reports Server (NTRS)
The Chilean Atacama Desert is the most arid region on Earth and in several ways analogous to Mars. Evidence suggests that the interior of the Atacama is lifeless, yet where the desert meets the Pacific coastal range dessication-tolerant microorganisms are known to exist. The gradient of biodiversity and habitats in the Atacama's subregions remain unexplored and are the focus of the Life in the Atacama project. Our field investigation attempts to bring further scientific understanding of the Atacama as a habitat for life through the creation of robotic astrobiology. This involves capabilities for autonomously traversing hundreds of kilometers while deploying sensors to survey the varying geologic and biologic properties of the environment, Fig. 1. Our goal is to make genuine discoveries about the limits of life on Earth and to generate knowledge about life in extreme environments that can be applied to future planetary missions. Through these experiments we also hope to develop and practice the methods by which a rover might best be employed to survey desert terrain in search of the habitats in which life can survive, or may have in the past.
Wettergreen, D.; Cabrol, N.; Whittaker, W.; Diaz, G. Chong; Calderon, F.; Heys, S.; Jonak, D.; Lueders, A.; Moersch, J.; Pane, D.
Modeling Habitat Split: Landscape and Life History Traits Determine Amphibian Extinction Thresholds
Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance the distance between the two required habitats affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations.
Fonseca, Carlos Roberto; Coutinho, Renato M.; Azevedo, Franciane; Berbert, Juliana M.; Corso, Gilberto; Kraenkel, Roberto A.
Elk migration patterns and human activity influence wolf habitat use in the Greater Yellowstone Ecosystem
Identifying the ecological dynamics underlying humanwildlife conflicts is important for the management and conservation of wildlife populations. In landscapes still occupied by large carnivores, many ungulate prey species migrate seasonally, yet little empirical research has explored the relationship between carnivore distribution and ungulate migration strategy. In this study, we evaluate the influence of elk (Cervus elaphus) distribution and other landscape features on wolf (Canis lupus) habitat use in an area of chronic wolflivestock conflict in the Greater Yellowstone Ecosystem, USA. Using three years of fine-scale wolf (n = 14) and elk (n = 81) movement data, we compared the seasonal habitat use of wolves in an area dominated by migratory elk with that of wolves in an adjacent area dominated by resident elk. Most migratory elk vacate the associated winter wolf territories each summer via a 4060 km migration, whereas resident elk remain accessible to wolves year-round. We used a generalized linear model to compare the relative probability of wolf use as a function of GIS-based habitat covariates in the migratory and resident elk areas. Although wolves in both areas used elk-rich habitat all year, elk density in summer had a weaker influence on the habitat use of wolves in the migratory elk area than the resident elk area. Wolves employed a number of alternative strategies to cope with the departure of migratory elk. Wolves in the two areas also differed in their disposition toward roads. In winter, wolves in the migratory elk area used habitat close to roads, while wolves in the resident elk area avoided roads. In summer, wolves in the migratory elk area were indifferent to roads, while wolves in resident elk areas strongly avoided roads, presumably due to the location of dens and summering elk combined with different traffic levels. Study results can help wildlife managers to anticipate the movements and establishment of wolf packs as they expand into areas with migratory or resident prey populations, varying levels of human activity, and front-country rangelands with potential for conflicts with livestock.
Nelson, Abigail; Kauffman, Matthew J.; Middleton, Arthur D.; Jimenez, Mike; McWhirter, Douglas; Barber, Jarrett; Gerow, Ken
The importance of habitat and life history to extinction risk in sharks, skates, rays and chimaeras
We compared life-history traits and extinction risk of chondrichthyans (sharks, rays and chimaeras), a group of high conservation concern, from the three major marine habitats (continental shelves, open ocean and deep sea), controlling for phylogenetic correlation. Deep-water chondrichthyans had a higher age at maturity and longevity, and a lower growth completion rate than shallow-water species. The average fishing mortality needed to drive a deep-water chondrichthyan species to extinction (Fextinct) was 3858% of that estimated for oceanic and continental shelf species, respectively. Mean values of Fextinct were 0.149, 0.250 and 0.368 for deep-water, oceanic and continental shelf species, respectively. Reproductive mode was an important determinant of extinction risk, while body size had a weak effect on extinction risk. As extinction risk was highly correlated with phylogeny, the loss of species will be accompanied by a loss of phylogenetic diversity. Conservation priority should not be restricted to large species, as is usually suggested, since many small species, like those inhabiting the deep ocean, are also highly vulnerable to extinction. Fishing mortality of deep-water chondrichthyans already exploited should be minimized, and new deep-water fisheries affecting chondrichthyans should be prevented.
Garcia, Veronica B; Lucifora, Luis O; Myers, Ransom A
Declining Lake Habitats in the Andes: Implications for Early Mars, Life, and Exploration (Invited)
NASA Astrophysics Data System (ADS)
The environment of the Andes presents analogies with Mars when the planet was transitioning from a wetter to a drier, colder climate: thin atmosphere, high solar irradiance, depleted ozone, high temperature fluctuations with low averages, ice, low precipitation and RH, and volcanic activity. This region is also among three areas of the world most impacted by climate change, which results in enhanced evaporation and high negative water balance that modifies lake habitat rapidly. Data shows strong interannual fluctuations in precipitation, water balance, major ion concentration, and pH are well marked. Microorganisms dwelling near the surface are exposed to a UV flux 170% that of sea level, and exceptionally high UVB levels. The thin cold atmosphere generates sudden and significant inverse relationship between UV and temperatures. In this cold, unstable environment lake habitats host abundant life. In addition to adaptation strategies, the timing of key cycles appears to be a critical factor in life survival. Environmental analogy with early Mars is multifold. Aridification has resulted in an evaporative environment. Latitude and altitude generate a UV-flux double that of present-day Mars at the equator and UVB only half that of the red planet, low average total ozone, and a low atmospheric pressure. Yearly temperature extremes range from -40C to +9C. Lakes are ice-covered starting austral fall, reaching maximum thickness by mid-winter. Thawing occurs in spring, but negative night temperatures result in the formation of a thin film of ice that thaws by mid-morning in spring and summer. Because of their geophysical environment, rapid climate change, isolation, and mostly uncharted ecosystems, these lakes are representative of an end-member class of terrestrial lakes and are meaningful analogs to early martian lakes. With differences inherent to the study of terrestrial analogs, the overall environmental similarity of Andean lakes with Mars at the Noachian/Hesperian transition makes them uniquely similar to early martian lakes and a window into the likely transformation they experienced during the transition period from a wet to a dry Mars. Our results show that decline was unlikely to be monotonical over time on Mars, and therefore probably challenging for putative life, if any, to adapt to. Physicochemical changes associated with such variability are significant. There is currently no data to show how this environmental roller coaster impacts biodiversity at the level of the overall populations density or that of the species. However, the relatively low diversity found in the samples of the microbial community is consistent with biodiversity loss and selection of specific species capable of mutating and adapting rapidly. The timing of key cycles appears critical to the ecosystems survival. Here, we will discuss our latest results, the main similarities and differences with Mars, and how exploring these analogs help us better learn how to identify their signatures on Mars.
Cabrol, N. A.; Grin, E. A.; High Lakes Project Team
Degree of adaptive response in urban tolerant birds shows influence of habitat-of-origin.
Urban exploiters and adapters are often coalesced under a term of convenience as 'urban tolerant'. This useful but simplistic characterisation masks a more nuanced interplay between and within assemblages of birds that are more or less well adapted to a range of urban habitats. I test the hypotheses that objectively-defined urban exploiter and suburban adapter assemblages within the broad urban tolerant grouping in Melbourne vary in their responses within the larger group to predictor variables, and that the most explanatory predictor variables vary between the two assemblages. A paired, partitioned analysis of exploiter and adapter preferences for points along the urban-rural gradient was undertaken to decompose the overall trend into diagnosable parts for each assemblage. In a similar way to that in which time since establishment has been found to be related to high urban densities of some bird species and biogeographic origin predictive of urban adaptation extent, habitat origins of members of bird assemblages influence the degree to which they become urban tolerant. Bird species that objectively classify as urban tolerant will further classify as either exploiters or adapters according to the degree of openness of their habitats-of-origin. PMID:24688881
Conole, Lawrence E
Degree of adaptive response in urban tolerant birds shows influence of habitat-of-origin
Urban exploiters and adapters are often coalesced under a term of convenience as urban tolerant. This useful but simplistic characterisation masks a more nuanced interplay between and within assemblages of birds that are more or less well adapted to a range of urban habitats. I test the hypotheses that objectively-defined urban exploiter and suburban adapter assemblages within the broad urban tolerant grouping in Melbourne vary in their responses within the larger group to predictor variables, and that the most explanatory predictor variables vary between the two assemblages. A paired, partitioned analysis of exploiter and adapter preferences for points along the urbanrural gradient was undertaken to decompose the overall trend into diagnosable parts for each assemblage. In a similar way to that in which time since establishment has been found to be related to high urban densities of some bird species and biogeographic origin predictive of urban adaptation extent, habitat origins of members of bird assemblages influence the degree to which they become urban tolerant. Bird species that objectively classify as urban tolerant will further classify as either exploiters or adapters according to the degree of openness of their habitats-of-origin.
Indigenous Microbiota and Habitat Influence Escherichia coli Survival More than Sunlight in Simulated Aquatic Environments
The reported fate of Escherichia coli in the environment ranges from extended persistence to rapid decline. Incomplete understanding of factors that influence survival hinders risk assessment and modeling of the fate of fecal indicator bacteria (FIB) and pathogens. FIB persistence in subtropical aquatic environments was explored in outdoor mesocosms inoculated with five E. coli strains. The manipulated environmental factors were (i) presence or absence of indigenous microbiota (attained by natural, disinfected, and cycloheximide treatments), (ii) freshwater versus seawater, and (iii) water column versus sediment matrices. When indigenous microbes were removed (disinfected), E. coli concentrations decreased little despite exposure to sunlight. Conversely, under conditions that included the indigenous microbiota (natural), significantly greater declines in E. coli occurred regardless of the habitat. The presence of indigenous microbiota and matrix significantly influenced E. coli decline, but their relative importance differed in freshwater versus seawater. Cycloheximide, which inhibits protein synthesis in eukaryotes, significantly diminished the magnitude of E. coli decline in water but not in sediments. The inactivation of protozoa and bacterial competitors (disinfected) caused a greater decline in E. coli than cycloheximide alone in water and sediments. These results indicate that the autochthonous microbiota are an important contributor to the decline of E. coli in fresh and seawater subtropical systems, but their relative contribution is habitat dependent. This work advances our understanding of how interactions with autochthonous microbiota influence the fate of E. coli in aquatic environments and provides the framework for studies of the ecology of enteric pathogens and other allochthonous bacteria in similar environments.
Korajkic, Asja; Wanjugi, Pauline
Temperature, humidity and depth of habitat influencing host destruction and fecundity of muscoid fly parasites
Comparisons of various strains of hymenopterous parasites,Muscidifurax raptor\\u000a Girault & Sanders,M. uniraptor\\u000a Kogan & Legner,M. zaraptor K. & L.,Spalangia cameroni\\u000a Perkins,S. endius\\u000a Walker,S. longepetiolata\\u000a Boucek,S. nigra\\u000a Latreille andSphegigaster sp. attackingMusca domestica L., showed that theSpalangia species consistently penetrated to the greatest depth, 4 cm, in an experimental wheat flakes habitat. Moisture influenced\\u000a penetration behaviour of some species. Host destruction wrought
E. F. Legner
Metazoan meiofaunal communities at cold seeps along the Norwegian margin: Influence of habitat heterogeneity and evidence for connection with shallow-water habitats
NASA Astrophysics Data System (ADS)
Cold-seep environments and their associated symbiont-bearing megafaunal communities create islands of primary production for macro- and meiofauna in the otherwise monotonous and nutrient-poor deep-sea environment. To examine the spatial variation and distribution patterns of metazoan meiobenthos in different seepage-related habitats, samples were collected in two regions off Norway: several pockmarks associated with the Storegga Slide including the Nyegga pockmark area (730 m; 64¯N), and the active, methane-venting HÍkon Mosby Mud Volcano (HMMV) west of the Barents Sea (1280 m; 72¯N). Based on sediment geochemistry and associated epifauna, three different habitat types were distinguished across the two regions: (1) reduced sediment with suboxic conditions, sometimes covered by bacterial mats, (2) sediment colonised by chemosynthetic, siboglinid tubeworms, and (3) sediment outside the influence of seepage and without a large chemosynthetic fauna. Meiofaunal communities varied strongly in terms of generic diversity and dominance among the different habitat types. Control sites and Siboglinidae polychaete fields both supported high nematode genus richness similar to normal deep-sea sediments, whereas the reduced sediments yielded a genus-poor nematode community dominated by one or two successful species. Meiofaunal densities in the different habitats were negatively correlated with macrobenthic densities. An extremely dense (>11,000 ind. 10 cm -2), mono-specific nematode population appeared to be restricted to the bacterial mats at HMMV. It consisted of a new cryptic species of the Halomonhystera disjuncta complex, which has been described from intertidal habitats in the North Sea. The reduced seep sediments at Nyegga did not yield H. disjuncta but were dominated by Terschellingia longicaudata, another cosmopolitan nematode species known to be abundant in organic-rich, oxygen-poor, shallow-water environments. These observations point to a past or recent connection between margins and shallow-water habitats.
Van Gaever, Saskia; Olu, Karine; Derycke, Sofie; Vanreusel, Ann
Bull trout life history, genetics, habitat needs, and limiting fact in central and northeast Oregon/1999.
National Technical Information Service (NTIS)
This section describes work accomplished in 1999 that continued to address two objectives of this project. These objectives are (1) determine the distribution of juvenile and adult bull trout Salvelinus confluentus and habitats associated with that distri...
The influence of stressful life events and coping strategies was studied in 50 depressed and 50 non-depressed persons. It was observed that depressives experienced significantly more stressful life events and were also using significantly more avoidance coping strategies as compared to their non-depressed counterparts. The moderate and severely depressed patients were exposed to more stressful life events and were using more avoidance coping strategies as compared to mildly depressed patients.
Satija, Y.K.; Advani, G.B.; Nathawat, S.S.
Factors Influencing Adjustment to Late-Life Divorce.
ERIC Educational Resources Information Center
Although the rate of divorce among older Americans has increased steadily, little attention has been paid to late life divorce. To describe the role of age and other factors which might influence adjustment to divorce in later life, data from a larger pilot study were used: 81 divorced persons over the age of 60 completed in-depth, structured
Wilson, Keren Brown; DeShane, Michael R.
Life History Influence on Teaching United States History.
ERIC Educational Resources Information Center
A qualitative study explored the influences of life and family histories on high school teachers' beliefs about U.S. history. Drawing on data gathered through surveys and in-depth interviews, this paper argues that personal knowledge acts as a lens through which teachers see and project subject matter in U.S. history. Inquiring into life history
Coughlin, Mimi
A hierarchical Bayesian model for embedding larval drift and habitat models in integrated life cycles for exploited fish.
This paper proposes a hierarchical Bayesian framework for modeling the life cycle of marine exploited fish with a spatial perspective. The application was developed for a nursery-dependent fish species, the common sole (Solea solea), on the Eastern Channel population (Western Europe). The approach combined processes of different natures and various sources of observations within an integrated framework for life-cycle modeling: (1) outputs of an individual-based model for larval drift and survival that provided yearly estimates of the dispersion and mortality of eggs and larvae, from spawning grounds to settlement in several coastal nurseries; (2) a habitat suitability model, based on juvenile trawl surveys coupled with a geographic information system, to estimate juvenile densities and surface areas of suitable juvenile habitat in each nursery sector; (3) a statistical catch-at-age model for the estimation of the numbers-at-age and the fishing mortality on subadults and adults. The approach provided estimates of hidden variables and parameters of key biological significance. A simulation approach provided insight to the robustness of the approach when only weak data are available. Estimates of spawning biomass, fishing mortality, and recruitment were close to the estimations derived from stock-assessment working groups. In addition, the model quantified mortality along the life cycle, and estimated site-specific density-dependent mortalities between settled larvae and age-0 juveniles in each nursery ground. This provided a better understanding of the productivity and the specific contribution of each nursery ground toward recruitment and population renewal. Perspectives include further development of the modeling framework on the common sole and applications to other fish species to disentangle the effects of multiple interacting stress factors (e.g., estuarine and coastal nursery habitat degradation, fishing pressure) on population renewal and to develop risk analysis in the context of marine spatial planning for sustainable management of fish resources. PMID:24261047
Rochette, S; Le Pape, O; Vigneau, J; Rivot, E
Potential Habitats For Life On Mars: Lessons From The Early Archean
The Hadean\\/Early Archaean Earth was characterised by generally submerged protocontinents on a water-covered planet. The supracrustal rocks deposited on top of the protocontinents from the Early Archaean terrains of Barberton (S. Africa) and the Pilbara (Australia) contain evidence of widespread distributions of fossil bacterial biofilms in almost all the habitats available. These include shallow -water, intertidal (saline), and possibly subaerial
F. Westall; A. Brack
Habitat fragmentation and species loss across three interacting trophic levels: effects of life-history and food-web traits.
Not all species are likely to be equally affected by habitat fragmentation; thus, we evaluated the effects of size of forest remnants on trophically linked communities of plants, leaf-mining insects, and their parasitoids. We explored the possibility of differential vulnerability to habitat area reduction in relation to species-specific and food-web traits by comparing species-area regression slopes. Moreover, we searched for a synergistic effect of these traits and of trophic level. We collected mined leaves and recorded plant, leaf miner, and parasitoid species interactions in five 100-m2 transects in 19 Chaco Serrano woodland remnants in central Argentina. Species were classified into extreme categories according to body size, natural abundance, trophic breadth, and trophic level. Species-area slopes differed between groups with extreme values of natural abundance or trophic specialization. Nevertheless, synergistic effects of life-history and food-web traits were only found for trophic level and trophic breadth: area-related species loss was highest for specialist parasitoids. It has been suggested that species position within interaction webs could determine their vulnerability to extinction. Our results provide evidence that food-web parameters, such as trophic level and trophic breadth, affect species sensitivity to habitat fragmentation. PMID:19765035
Cagnolo, Luciano; Valladares, Graciela; Salvo, Adriana; Cabido, Marcelo; Zak, Marcelo
Habitat stress, species pool size and biotic resistance influence exotic plant richness in the Flooding Pampa grasslands
Summary 1 Theory and empirical evidence suggest that community invasibility is influenced by propagule pressure, physical stress and biotic resistance from resident species. We studied patterns of exotic and native species richness across the Flooding Pampas of Argentina, and tested for exotic richness correlates with major environmental gradients, species pool size, and native richness, among and within different grassland habitat
The influence of research scale on bald eagle habitat selection along the lower Hudson River, New York (USA)
As the concepts of landscape ecology have been incorporated into other disciplines, the influence of spatial pat- terns on animal abundance and distribution has attracted considerable attention. However, there remains a sig- nificant gap in the application of landscape ecology theories and techniques to wildlife research. By combining landscape ecology techniques with traditional wildlife habitat analysis methods, we defined an
Craig M. Thompson; Kevin McGarigal
The influence of research scale on bald eagle habitat selection along the lower Hudson River, New York (USA)
As the concepts of landscape ecology have been incorporated into otherdisciplines, the influence of spatial patterns on animal abundance anddistribution has attracted considerable attention. However, there remains asignificant gap in the application of landscape ecology theories and techniquesto wildlife research. By combining landscape ecology techniques withtraditionalwildlife habitat analysis methods, we defined an organism-centeredperspectivefor breeding bald eagles (Haliaeetus leucocephalus) alongthe Hudson
Craig M. Thompson; Kevin McGarigal
Scale-dependent influences on water quality, habitat, and fish communities in streams of the Kalamazoo River Basin, Michigan (USA)
. In 2002, we investigated regional versus local influences of 22 streams in the Kalamazoo River basin, MI (USA) to: 1) determine\\u000a how stream water quality, habitat, and fish communities were influenced by environmental variables at multiple spatial scales,\\u000a and 2) examine linkages among watershed, riparian corridor (total and local stream corridors), and instream characteristics.\\u000a Our data show that environmental patterns
Ashley H. Moerke; Gary A. Lamberti
13.1.3. Life History Strategies and Habitat Needs of the Northern Pintail
The northern pintail (hereafter pintail) is a common dabbling duck distributed throughout the Northern Hemisphere. Since 1955, the breeding population in North America has averaged 5,566,000, fluctuating between 10,124,000 (1956) and 2,471,000 (1989; Fig. 1). Pintail numbers are especially sensitive to habitat conditions that reflect the wetdry cycle in the shortgrass prairie breeding areas of south-central Canada and the northern
Leigh H. Fredrickson; Mickey E. Heitmeyer
Does life-history variability in salmonids affect habitat use by juveniles? A comparison among streams open and closed to anadromy.
1. Migratory and resident forms of salmonids coexist in many river systems. Although such coexistence is widespread, little is known about its ecological basis and no studies have compared the habitat use of premigratory juveniles and residents. 2. We employed a comparative approach to explore the differential habitat use of juvenile anadromous and resident brook trout. This required the investigation of habitat use in streams closed to anadromy, containing only resident brook trout Salvelinus fontinalis ('resident-only' streams) and streams open to anadromy, containing coexisting Atlantic salmon Salmo salar and anadromous and resident brook trout ('migrant-resident' streams). 3. We demonstrate that fast habitats (riffles) are occupied more frequently in streams with migratory brook trout relative to riffle habitats of streams with only resident brook trout. In contrast, occupation of slow current velocities (pools) was observed in both migrant-resident and resident-only streams as both stream types contain resident brook trout. The net effect is a wider distribution of occupied habitats (pool and riffles) in migrant-resident streams relative to resident-only streams, resulting in few, if any, unused habitats. 4. These results are consistent with previously reported bioenergetic, morphological and stable isotope differences observed between anadromous and resident brook trout. 5. Our findings suggest that a link exists between juvenile habitat use, metabolic costs and life-history strategies. PMID:16689952
Morinville, GeneviÒve R; Rasmussen, Joseph B
Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 2001.
Bull trout Salvelinus confluentus exhibit a number of life history strategies. Stream-resident bull trout complete their life cycle in their natal tributaries. Migratory bull trout spawn in tributary streams where juvenile fish usually spend from one to four years before migrating to either a larger river (fluvial) or lake (adfluvial) where they rear before returning to the tributary stream to spawn (Fraley and Shepard 1989). These migratory forms occur where conditions allow movement from spawning locations to downstream waters that provide greater foraging opportunities (Dunham and Rieman 1999). Resident and migratory forms may occur together, and either form can produce resident or migratory offspring (Rieman and McIntyre 1993). The ability to migrate is important to the persistence of local bull trout populations (Rieman and McIntyre 1993). The identification of migratory corridors can help focus habitat protection efforts. Determining the life history form(s) that comprise local populations, the timing of seasonal movements, and the geographic extent of these movements are critical to bull trout protection and recovery efforts. This section describes work accomplished in 2001 that continued to address two objectives of this project. These objectives are (1) determine the distribution of juvenile and adult bull trout and habitats associated with that distribution, and (2) determine fluvial and resident bull trout life history patterns. Completion of these objectives is intended through studies of bull trout in the Grande Ronde, Walla Walla, and John Day basins. These basins were selected because they provide a variety of habitats, from relatively degraded to pristine, and bull trout populations were thought to vary from relatively depressed to robust. In the Grande Ronde and Walla Walla basins, we continued to monitor the movements of bull trout with radio transmitters applied in 1998 (Hemmingsen, Bellerud, Gunckel and Howell 2001) and 1999 (Hemmingsen, Gunckel and Howell 2001). No new radio transmitters were applied to bull trout of the upper John Day River subbasin, Mill Creek (Walla Walla Basin), or the Grande Ronde Basin in 2001. In Mill Creek, we used traps for the fourth consecutive year to obtain data on migrant bull trout. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, and to determine the relative abundance and size of migrant fish. No traps were operated in the John Day Basin in 2001.
Hemmingsen, Alan R.; Gunckel, Stephanie L.; Sankovich, Paul M.; Howell, Philip J.
Salmon Life Histories, Habitat, and Food Webs in the Columbia River Estuary: An Overview of Research Results, 2002-2006.
From 2002 through 2006 we investigated historical and contemporary variations in juvenile Chinook salmon Oncorhynchus tshawytscha life histories, habitat associations, and food webs in the lower Columbia River estuary (mouth to rkm 101). At near-shore beach-seining sites in the estuary, Chinook salmon occurred during all months of the year, increasing in abundance from January through late spring or early summer and declining rapidly after July. Recently emerged fry dispersed throughout the estuary in early spring, and fry migrants were abundant in the estuary until April or May each year. Each spring, mean salmon size increased from the tidal freshwater zone to the estuary mouth; this trend may reflect estuarine growth and continued entry of smaller individuals from upriver. Most juvenile Chinook salmon in the mainstem estuary fed actively on adult insects and epibenthic amphipods Americorophium spp. Estimated growth rates of juvenile Chinook salmon derived from otolith analysis averaged 0.5 mm d-1, comparable to rates reported for juvenile salmon Oncorhynchus spp. in other Northwest estuaries. Estuarine salmon collections were composed of representatives from a diversity of evolutionarily significant units (ESUs) from the lower and upper Columbia Basin. Genetic stock groups in the estuary exhibited distinct seasonal and temporal abundance patterns, including a consistent peak in the Spring Creek Fall Chinook group in May, followed by a peak in the Western Cascades Fall Chinook group in July. The structure of acanthocephalan parasite assemblages in juvenile Chinook salmon from the tidal freshwater zone exhibited a consistent transition in June. This may have reflected changes in stock composition and associated habitat use and feeding histories. From March through July, subyearling Chinook salmon were among the most abundant species in all wetland habitat types (emergent, forested, and scrub/shrub) surveyed in the lower 100 km of the estuary. Salmon densities within wetland habitats fell to low levels by July, similar to the pattern observed at mainstem beach-seining sites and coincident with high water temperatures that approached or exceeded 19 C by mid-summer. Wetland habitats were used primarily by small subyearling Chinook salmon, with the smallest size ranges (i.e., rarely exceeding 70 mm by the end of the wetland rearing season) at scrub/shrub forested sites above rkm 50. Wetland sites of all types were utilized by a diversity of genetic stock groups, including less abundant groups such as Interior Summer/Fall Chinook.
Bottom, Daniel L.; Anderson, Greer; Baptisa, Antonio
Chronic diseases influence major life changing decisions: a new domain in quality of life research.
The purpose of this review is to identify knowledge about the influence of chronic disease on major life changing decisions (MLCDs). This review was carried out in three stages: identification of key search terms; selection of databases and searching parameters; and evaluation of references. Only two articles matched the main search term 'major life changing decisions'. No article reviewed or measured the influence of chronic disease on major life changing decisions. However, 76 articles and various sections of seven books were identified that provided insight into this area and these are reviewed in detail. This literature review has brought together previously scattered information on chronic disease impact on important patient life decisions. These include decisions related to having children, marriage and divorce, job and career choice, social life, holidays, travelling and education. Lifestyle decisions viewed by patients as major decisions are also documented. The influence of cancer on life decisions is discussed, as are affected life decisions of other family members. Very little information is available about the long-term impact of chronic disease on patients' lives and methodology to assess long-term impact is incomplete. This review points to a novel dimension to health-related outcome research, the impact of chronic disease on major life changing decisions, and its possible implication for patients' future health. PMID:21659399
Bhatti, Zu; Salek, Ms; Finlay, Ay
Chronic diseases influence major life changing decisions: a new domain in quality of life research
The purpose of this review is to identify knowledge about the influence of chronic disease on major life changing decisions (MLCDs). This review was carried out in three stages: identification of key search terms; selection of databases and searching parameters; and evaluation of references. Only two articles matched the main search term major life changing decisions. No article reviewed or measured the influence of chronic disease on major life changing decisions. However, 76 articles and various sections of seven books were identified that provided insight into this area and these are reviewed in detail. This literature review has brought together previously scattered information on chronic disease impact on important patient life decisions. These include decisions related to having children, marriage and divorce, job and career choice, social life, holidays, travelling and education. Lifestyle decisions viewed by patients as major decisions are also documented. The influence of cancer on life decisions is discussed, as are affected life decisions of other family members. Very little information is available about the long-term impact of chronic disease on patients' lives and methodology to assess long-term impact is incomplete. This review points to a novel dimension to health-related outcome research, the impact of chronic disease on major life changing decisions, and its possible implication for patients' future health.
Bhatti, ZU; Salek, MS; Finlay, AY
Does Habitat Heterogeneity in a Multi-Use Landscape Influence Survival Rates and Density of a Native Mesocarnivore?
The relationships between predators, prey, and habitat have long been of interest to applied and basic ecologists. As a native Great Plains mesocarnivore of North America, swift foxes (Vulpes velox) depended on the historic disturbance regime to maintain open grassland habitat. With a decline in native grasslands and subsequent impacts to prairie specialists, notably the swift fox, understanding the influence of habitat on native predators is paramount to future management efforts. From 2001 to 2004, we investigated the influence of vegetation structure on swift fox population ecology (survival and density) on and around the Piþon Canyon Maneuver Site, southeastern Colorado, USA. We monitored 109 foxes on 6 study sites exposed to 3 different disturbance regimes (military training, grazing, unused). On each site we evaluated vegetation structure based on shrub density, basal coverage, vegetation height, and litter. Across all sites, annual fox survival rates ranged from 0.50 to 0.92 for adults and 0.27 to 0.78 for juveniles. Among sites, population estimates ranged from 1 to 7 foxes per 10 km transect. Fox density or survival was not related to the relative abundance of prey. A robust model estimating fox population size and incorporating both shrub density and percent basal cover as explanatory variables far outperformed all other models. Our results supported the idea that, in our region, swift foxes were shortgrass prairie specialists and also indicated a relationship between habitat quality and landscape heterogeneity. We suggest the regulation of swift fox populations may be based on habitat quality through landscape-mediated survival, and managers may effectively use disturbance regimes to create or maintain habitat for this native mesocarnivore.
Gese, Eric M.; Thompson, Craig M.
Diversity and habitat relationships of hypogeous fungi. III. Factors influencing the occurrence of fire-adapted species.
Among the huge array of hypogeous ectomycorrhizal fungi so far documented from Australia, six genera and more than 30 species occur within the family Mesophelliaceae, all of which show various adaptations for surviving in fire-prone landscapes. These mostly endemic fungi are critical to postfire reestablishment of regenerating vegetation, and their fruit-bodies provide essential food resources for diverse ground-dwelling fauna. We developed habitat models for five common representatives of the Mesophelliaceae based on repeat collections of their fruit-bodies from 136 study plots situated along a series of environmental gradients across the south-eastern mainland of Australia. At a meso- or landscape scale, temperature influenced the occurrence of Castoreum radicatum, Mesophellia clelandii and Nothocastoreum cretaceum, with the type of response varying. Below a threshold, C. radicatum preferred sites with cooler mean annual temperatures. In contrast, M. clelandii and N. cretaceum had optimal ranges of temperature, above and below which the probability of detecting them dropped. Also at a landscape scale, C. radicatum was more likely to be detected at sites with lower levels of precipitation during the driest quarter of the year. At a micro-site scale, M. clelandii and N. cretaceum were more likely to occur in stands with an intermediate number of host eucalypt stems, likely relating to successional age of the stand. Sites with a higher number of large fallen trees were more likely to have N. cretaceum, while sites with intermediate litter depths were more likely to have C. radicatum and M. clelandii. Mesophellia glauca and M. trabalis showed no consistent patterns. They are apparently the most broadly adaptable in terms of the independent variables tested. Although fire has been previously suggested to be heavily implicated in the life cycle of several members of the Mesophelliaceae, we found no relationship between time since disturbance by fire and other factors and likelihood of occurrence. Instead, other habitat attributes appeared to be more important in explaining their distribution. The complex and differing responses of the species of Mesophelliaceae studied here, to features of their environment, reinforce the need to manage multiple-use forest landscapes across the region for a diversity of attributes. PMID:19269321
Claridge, Andrew W; Trappe, James M; Mills, Douglas J; Claridge, Debbie L
Differential influence of a monotypic and diverse native aquatic plant bed on a macroinvertebrate assemblage; an experimental implication of exotic plant induced habitat
Aquatic plants mediate ecological processes in aquatic habitats, specifically predatorprey (bluegill sunfish (Lepomis macrochirus Rafinesque)-macroinvertebrate) interactions. Macroinvertebrate colonization is directly and indirectly influenced by substrate\\u000a heterogeneity, interstitial space, and surface complexity. Exotic invasive plant species, such as Hydrilla verticillata L.F. Royle, may alter the available structure in aquatic habitat by creating a shift to a homogeneous habitat, thus affecting\\u000a the
Heather J. Theel; Eric D. Dibble; John D. Madsen
Influence of habitat manipulations on interactions between cutthroat trout and invertebrate drift. [Salmo clarki
The objectives of this study were to examine the interactions of the riparian setting (logged vs forested) and prey availability on the prey capture efficiency and growth of cutthroat trout, and to determine if the riparian setting influences the impact of trout predation on drift composition. Short-term relative growth rates of cutthroat trout, experimentally confined in stream pools, were greater in a logged than in a forested section of stream. Differences in growth rates were attributed to differences, among pools in invertebrate drift density, and to differences in trout foraging efficiency that were related to differences between the sections in the amount of overhead shading and substrate crevices. Mean percentages of introduced prey captured by trout were greater in logged control pools and pools of both sections whose bottoms were covered with fiberglass screening to eliminate substrate crevices than in forested control pools and logged pools that were artificially shaded. A logarithmic relationship was found between trout foraging efficiency and surface light of pools. Drift density significantly increased relative to controls in pools from which trout were removed in the logged reach, but not in the forested section. This may result from habitat features in the logged section that favor greater trout foraging success and the occurrence of behaviorally drifting prey taxa, which represent a predictable food supply for the trout.
Wilzbach, M.A.; Cummins, K.W.; Hall, J.D.
Hunting influences the diel patterns in habitat selection by northern pintails Anas acuta
Northern pintail Anas acuta (hereafter pintail) populations wintering within Suisun Marsh, a large estuarine managed wetland near San Francisco Bay, California,USA, have declined markedly over the last four decades. The reasons for this decline are unclear. Information on how hunting and other factors influence the selection of vegetation types and sanctuaries would be beneficial to manage pintail populations in SuisunMarsh. During 1991-1993, we radio-marked and relocated female pintails (individuals: N = 203, relocations: N = 7,688) within Suisun Marsh to investigate habitat selection during the non-breeding months (winter). We calculated selection ratios for different vegetation types and for sanctuaries, and examined differences in those ratios between hunting season (i.e. hunting and non-hunting), age (hatchyear and after-hatch-year), and time of day (daylight or night hours). We found that diel patterns in selection were influenced by hunting disturbance. For example, prior to the hunting season and during daylight hours, pintails selected areas dominated by brass buttons Cotula coronopifolia, a potentially important food source, usually outside of sanctuary boundaries. However, during the hunting season, pintails did not select brass buttons during daylight hours, but instead highly selected permanent pools, mostly within sanctuaries. Also, during the hunting season, pintails showed strong selection for brass buttons at night. Sanctuaries provided more area of permanent water pools than within hunting areas and appeared to function as important refugia during daylight hours of the hunting season. Wildlife managers should encourage large protected permanent pools adjacent to hunted wetlands to increase pintail numbers within wetland environments and responsibly benefit hunting opportunities while improving pintail conservation.
Casazza, Michael L.; Coates, Peter S.; Miller, Michael R.; Overton, Cory T.; Yparraguirre, Daniel R.
DNA methylation, ageing and the influence of early life nutrition.
It is well established that genotype plays an important role in the ageing process. However, recent studies have suggested that epigenetic mechanisms may also influence the onset of ageing-associated diseases and longevity. Epigenetics is defined as processes that induce heritable changes in gene expression without a change in the DNA nucleotide sequence. The major epigenetic mechanisms are DNA methylation, histone modification and non-coding RNA. Such processes are involved in the regulation of tissue-specific gene expression, cell differentiation and genomic imprinting. However, epigenetic dysregulation is frequently seen with ageing. Relatively little is known about the factors that initiate such changes. However, there is emerging evidence that the early life environment, in particular nutrition, in early life can induce long-term changes in DNA methylation resulting in an altered susceptibility to a range of ageing-associated diseases. In this review, we will focus on the changes in DNA methylation that occur during ageing; their role in the ageing process and how early life nutrition can modulate DNA methylation and influence longevity. Understanding the mechanisms by which diet in early life can influence the epigenome will be crucial for the development of preventative and intervention strategies to increase well-being in later life. PMID:25027290
Lillycrop, Karen A; Hoile, Samuel P; Grenfell, Leonie; Burdge, Graham C
Searching for microbial life remotely: Satellite-to-rover habitat mapping in the Atacama Desert, Chile
The Atacama Desert, one of the most arid landscapes on Earth, serves as an analog for the dry conditions on Mars and as a test bed in the search for life on other planets. During the Life in the Atacama (LITA) 2004 field experiment, satellite imagery and ground-based rover data were used in concert with a follow-the-water exploration strategy to
K. Warren-Rhodes; S. Weinstein; J. Dohm; J. Piatek; E. Minkley; A. Hock; C. Cockell; D. Pane; L. A. Ernst; G. Fisher; S. Emani; A. S. Waggoner; N. A. Cabrol; D. S. Wettergreen; D. Apostolopoulos; P. Coppin; E. Grin; Chong Diaz; J. Moersch; G. G. Oril; T. Smith; K. Stubbs; G. Thomas; M. Wagner; M. Wyatt
The Influence of Social Structure, Habitat, and Host Traits on the Transmission of Escherichia coli in Wild Elephants
Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental, and host-related factors that influence transmission patterns.
Chiyo, Patrick I.; Grieneisen, Laura E.; Wittemyer, George; Moss, Cynthia J.; Lee, Phyllis C.; Douglas-Hamilton, Iain; Archie, Elizabeth A.
The influence of social structure, habitat, and host traits on the transmission of Escherichia coli in wild elephants.
Social structure is proposed to influence the transmission of both directly and environmentally transmitted infectious agents. However in natural populations, many other factors also influence transmission, including variation in individual susceptibility and aspects of the environment that promote or inhibit exposure to infection. We used a population genetic approach to investigate the effects of social structure, environment, and host traits on the transmission of Escherichia coli infecting two populations of wild elephants: one in Amboseli National Park and another in Samburu National Reserve, Kenya. If E. coli transmission is strongly influenced by elephant social structure, E. coli infecting elephants from the same social group should be genetically more similar than E. coli sampled from members of different social groups. However, we found no support for this prediction. Instead, E. coli was panmictic across social groups, and transmission patterns were largely dominated by habitat and host traits. For instance, habitat overlap between elephant social groups predicted E. coli genetic similarity, but only in the relatively drier habitat of Samburu, and not in Amboseli, where the habitat contains large, permanent swamps. In terms of host traits, adult males were infected with more diverse haplotypes, and males were slightly more likely to harbor strains with higher pathogenic potential, as compared to adult females. In addition, elephants from similar birth cohorts were infected with genetically more similar E. coli than elephants more disparate in age. This age-structured transmission may be driven by temporal shifts in genetic structure of E. coli in the environment and the effects of age on bacterial colonization. Together, our results support the idea that, in elephants, social structure often will not exhibit strong effects on the transmission of generalist, fecal-oral transmitted bacteria. We discuss our results in the context of social, environmental, and host-related factors that influence transmission patterns. PMID:24705319
Chiyo, Patrick I; Grieneisen, Laura E; Wittemyer, George; Moss, Cynthia J; Lee, Phyllis C; Douglas-Hamilton, Iain; Archie, Elizabeth A
Invertebrate communities of forested limesink wetlands in southwest Georgia, USA: Habitat use and influence of extended inundation
Limesink wetlands are a common aquatic habitat in southwest Georgia, USA. These wetlands are non-alluvial, occupying shallow\\u000a depressions formed from dissolution of limestone bedrock and collapse of surface sands. They are seasonally inundated, with\\u000a a typical hydroperiod extending from late February to early July. Little is known about factors influencing invertebrate community\\u000a structure in limesink wetlands. Recently, it has been
Stephen W. Golladay; Brad W. Taylor; Brian J. Palikt
Abundance, Behavior, and Habitat Utilization by Coho Salmon and Steelhead Trout in Fish Creek, Oregon, as Influenced by Habitat Enhancement: Annual Report 1985
Construction and evaluation of salmonid habitat improvements on Fish Creek, a tributary of the upper Clackamas River, is designed to increase the annual number of chinook and coho salmon, and steelhead trout smolt outmigrants. The primary objectives of the evaluation include the: (1) evaluation and quantification of changes in salmonid spawning and rearing habitat resulting from a variety of habitat
Everest; Fred H
Floral and nesting resources, habitat structure, and fire influence bee distribution across an open-forest gradient
Given bees' central effect on vegetation communities, it is important to understand how and why bee distributions vary across ecological gradients. We examined how plant community composition, plant diversity, nesting suitability, canopy cover, land use, and fire history affected bee distribution across an open-forest gradient in northwest Indiana, USA, a gradient similar to the historic Midwest United States landscape mosaic. When considered with the other predictors, plant community composition was not a significant predictor of bee community composition. Bee abundance was negatively related to canopy cover and positively to recent fire frequency, bee richness was positively related to plant richness and abundance of potential nesting resources, and bee community composition was significantly related to plant richness, soil characteristics potentially related to nesting suitability, and canopy cover. Thus, bee abundance was predicted by a different set of environmental characteristics than was bee species richness, and bee community composition was predicted, in large part, by a combination of the significant predictors of bee abundance and richness. Differences in bee community composition along the woody vegetation gradient were correlated with relative abundance of oligolectic, or diet specialist, bees. Because oligoleges were rarer than diet generalists and were associated with open habitats, their populations may be especially affected by degradation of open habitats. More habitat-specialist bees were documented for open and forest/scrub habitats than for savanna/woodland habitats, consistent with bees responding to habitats of intermediate woody vegetation density, such as savannas, as ecotones rather than as distinct habitat types. Similarity of bee community composition, similarity of bee abundance, and similarity of bee richness between sites were not significantly related to proximity of sites to each other. Nestedness analysis indicated that species composition in species-poor sites was not merely a subset of species composition at richer sites. The lack of significant proximity or nestedness effects suggests that factors at a small spatial scale strongly influence bees' use of sites. The findings indicate that patterns of plant diversity, nesting resource availability, recent fire, and habitat shading, present at the scale of a few hundred meters, are key determinants of bee community patterns in the mosaic open-savanna-forest landscape. ?? 2010 by the Ecological Society of America.
Grundel, R.; Jean, R. P.; Frohnapple, K. J.; Glowacki, G. A.; Scott, P. E.; Pavlovic, N. B.
The influence of habitat quality on the foraging strategies of the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis megidis.
Entomopathogenic nematodes (EPN) are soil-transmitted parasites and their foraging strategies are believed to range from 'ambush' to 'cruise' foragers. However, research on their behaviour has not considered the natural habitat of these nematodes. We hypothesized that EPN behaviour would be influenced by soil habitat quality and tested this hypothesis using 2 EPN species Steinernema carpocapsae (an 'ambusher') and Heterorhabditis megidis (a 'cruiser') in 2 contrasting habitats, sand and peat. As predicted from previous studies, in sand most S. carpocapsae remained at the point of application and showed no taxis towards hosts, but in peat S. carpocapsae dispersed much more and showed a highly significant taxis towards hosts. H. megidis dispersed well in both media, but only showed taxis towards hosts in sand. In outdoor mesocosms in which both species were applied, S. carpocapsae outcompeted H. megidis in terms of host finding in peat, whereas the opposite was true in sand. Our data suggest that these 2 EPN may be habitat specialists and highlight the difficulties of studying soil-transmitted parasites in non-soil media. PMID:19835647
Kruitbos, L M; Heritage, S; Hapca, S; Wilson, M J
Natural and anthropogenic influences on a red-crowned crane habitat in the Yellow River Delta Natural Reserve, 1992-2008.
This study aims to assess the relative importance of natural and anthropogenic variables on the change of the red-crowned crane habitat in the Yellow River Nature Reserve, East China using multitempopral remote sensing and geographic information system. Satellite images were used to detect the change in potential crane habitat, from which suitable crane habitat was determined by excluding fragmented habitat. In this study, a principal component analysis (PCA) with seven variables (channel flow, rainfall, temperature, sediment discharge, number of oil wells, total length of roads, and area of settlements) and linear regression analyses of potential and suitable habitat against the retained principal components were applied to explore the influences of natural and anthropogenic factors on the change of the red-crowned crane habitat. The experimental results indicate that suitable habitat decreased by 5,935 ha despite an increase of 1,409 ha in potential habitat from 1992 to 2008. The area of crane habitat changed caused by natural drivers such as progressive succession, retrogressive succession, and physical fragmentation is almost the same as that caused by anthropogenic forces such as land use change and behavioral fragmentation. The PCA and regression analyses revealed that natural factors (e.g., channel flow, rainfall, temperature, and sediment discharge) play an important role in the crane potential habitat change and human disturbances (e.g., oil wells, roads, and settlements) jointly explain 51.8 % of the variations in suitable habitat area, higher than 48.2 % contributed by natural factors. Thus, it is vital to reduce anthropogenic influences within the reserve in order to reverse the decline in the suitable crane habitat. PMID:24526617
Wang, Hong; Gao, Jay; Pu, Ruiliang; Ren, Liliang; Kong, Yan; Li, He; Li, Ling
Wavelength-specific photosynthetic responses of Halophila johnsonii from marine-influenced versus river-influenced habitats
The seagrass Halophila johnsonii Eiseman grows from the upper intertidal to 3m depths in habitats ranging from near-marine inlets to tidal riverine. These habitats have distinct optical characteristics, primarily due to variable concentrations of watershed-derived chromophoric dissolved organic matter (CDOM), which increases the attenuation of short-wavelength (blue and UV) light. H. johnsonii contains a suite of flavonoids that are thought
Amanda E. Kahn; Michael J. Durako
Robotic ecological mapping: Habitats and the search for life in the Atacama Desert
As part of the three-year `Life in the Atacama' (LITA) project, plant and microbial abundance were mapped within three sites in the Atacama Desert, Chile, using an automated robotic rover. On-board fluorescence imaging of six biological signatures (e.g., chlorophyll, DNA, proteins) was used to assess abundance, based on a percent positive sample rating system and standardized robotic ecological transects. The
K. Warren-Rhodes; S. Weinstein; J. L. Piatek; J. Dohm; A. Hock; E. Minkley; D. Pane; L. A. Ernst; G. Fisher; S. Emani; A. S. Waggoner; N. A. Cabrol; D. S. Wettergreen; E. Grin; P. Coppin; Chong Diaz; J. Moersch; G. G. Oril; T. Smith; K. Stubbs; G. Thomas; M. Wagner; M. Wyatt; L. Ng Boyle
Robotic ecological mapping: Habitats and the search for life in the Atacama Desert
As part of the three-year Life in the Atacama (LITA) project, plant and microbial abundance were mapped within three sites in the Atacama Desert, Chile, using an automated robotic rover. On-board fluorescence imaging of six biological signatures (e.g., chlorophyll, DNA, proteins) was used to assess abundance, based on a percent positive sample rating system and standardized robotic ecological transects. The
K. Warren-Rhodes; S. Weinstein; J. L. Piatek; J. Dohm; A. Hock; E. Minkley; D. Pane; L. A. Ernst; G. Fisher; S. Emani; A. S. Waggoner; N. A. Cabrol; D. S. Wettergreen; E. Grin; P. Coppin; Chong Diaz; J. Moersch; G. G. Oril; T. Smith; K. Stubbs; G. Thomas; M. Wagner; M. Wyatt; L. Ng Boyle
Bull Trout Life History, Genetics, Habitat Needs, and Limiting Factors in Central and Northeast Oregon, Annual Report 2000.
This section describes work accomplished in 2000 that continued to address two objectives of this project. These objectives are (1) determine the distribution of juvenile and adult bull trout Salvelinus confluentus and habitats associated with that distribution, and (2) determine fluvial and resident bull trout life history patterns. Completion of these objectives is intended through studies of bull trout in the Grande Ronde, Walla Walla, and John Day basins. These basins were selected because they provide a variety of habitats, from relatively degraded to pristine, and bull trout populations were thought to vary from relatively depressed to robust. In all three basins we continued to monitor the movements of bull trout with radio transmitters applied in 1998 (Hemmingsen, Bellerud, Gunckel and Howell 2001) and 1999 (Hemmingsen, Gunckel and Howell 2001). No new radio transmitters were applied to bull trout of the upper John Day River subbasin, Mill Creek (Walla Walla Basin), or the Grande Ronde Basin in 2000. We did implant radio transmitters in two bull trout incidentally captured in the John Day River near the confluence of the North Fork John Day River. In Mill Creek, we used traps to capture migrant bull trout to obtain data for the third successive year in this stream. With these traps, we intended to determine the timing of bull trout movements both upstream and downstream, and to determine the relative abundance, size and age of migrant fish. Because we captured migrant bull trout with traps for three years in the upper John Day River and its tributaries (Hemmingsen, Bellerud, Buchanan, Gunckel, Shappart and Howell 2001; Hemmingsen, Bellerud, Gunckel and Howell 2001; Hemmingsen, Gunckel and Howell 2001) and traps were no longer needed to capture bull trout for radio-tagging, no traps were operated in the John Day Basin in 2000.
Hemmingsen, Alan R.; Gunckel, Stephanie L.; Sankovich, Paul M.; Howell, Philip J.
Influence of dams and habitat condition on the distribution of redhorse (Moxostoma) species in the Grand River watershed, Ontario
Redhorse, Moxostoma spp., are considered to be negatively affected by dams although this assertion is untested for Canadian populations. One hundred and fifty-one sites in the Grand River watershed were sampled to identify factors influencing the distribution of redhorse species. Individual species of redhorse were captured from 3 to 32% of sites. The most widespread species were golden redhorse, M. erythrurum (30%) and greater redhorse, M. valenciennesi (32%), while river redhorse, M. carinatum, was only found along the lower Grand River. Redhorse were absent from the highly fragmented Speed River sub-watershed and upper reaches of the Conestogo River and the Grand River. Redhorse species richness was positively correlated to river fragment size and upstream drainage area. Generalized additive models (GAMs) were applied to evaluate the influence of river fragment length, connectivity and habitat on species distribution. Principal component analysis reduced habitat data to three axes representing: channel structure, substrate, and pool, riffle and run habitats (PC1); gradient and drainage area (PC2); and cover (PC3). GAMs indicate that PC2 was important for predicting black redhorse and greater redhorse site occupancy and PC1 was important for golden redhorse. River fragment length was important for predicting site occupancy for shorthead redhorse, but not other species. ?? 2006 Springer Science+Business Media, Inc.
Reid, S. M.; Mandrak, N. E.; Carl, L. M.; Wilson, C. C.
Nitrogen deposition and climate effects on soil nitrogen availability: influences of habitat type and soil characteristics.
The amount of plant-available nitrogen (N) in soil is an important indicator of eutrophication of semi-natural habitats, but previous studies have shown contrasting effects of N deposition on mineralisable N in different habitats. The stock of readily mineralisable N (N(rm)) was measured in 665 locations across Britain from a range of intensively and extensively managed habitats, allowing N availability to be studied in relation to soil and vegetation type, and also to variation in climate and in reactive N deposition from the atmosphere. Mineralisable N contents were correlated with deposition in extensively managed habitats but not in intensively managed habitats. The following statements apply only to extensively managed habitats. All habitats showed a similar increase in N(rm) with N deposition. However, soil characteristics affected the relationship, and soil carbon content in particular was a major control on mineralisation. The N(rm) stock increased more with N deposition in organic than in mineral soils. The nitrate proportion of N(rm) also increased with N deposition but, conversely, this increase was greater in mineral than in organic soils. The measurements could be used as indicators of eutrophication, e.g. deposition rates of over 20 kg N ha(-1) y(-1) are associated with nitrate proportions of >41% in a mineral soil (2% carbon), and with N(rm) stocks of over 4.8 kg N ha(-1) in an organic soil (55% carbon). Both N(rm) and nitrate proportion increased with mean annual temperature of the sampling location, despite consistent incubation temperature, suggesting that increasing temperatures are likely to increase the eutrophying effects of N pollution on semi-natural ecosystems. PMID:22245213
Rowe, E C; Emmett, B A; Frogbrook, Z L; Robinson, D A; Hughes, S
Influence of monsoon-related riparian phenology on yellow-billed cuckoo habitat selection in Arizona
Aim: The western yellow-billed cuckoo (Coccyzus americanus occidentalis), a Neotropical migrant bird, is facing steep population declines in its western breeding grounds owing primarily to loss of native habitat. The favoured esting habitat for the cuckoo in the south-western United States is low-elevation riparian forests and woodlands. Our aim was to explore relationships between vegetation phenology patterns captured by satellite phenometrics and the distribution of the yellow-billed cuckoo, and to use this information to map cuckoo habitat. Location: Arizona, USA. Methods: Land surface phenometrics were derived from satellite Advanced Very High-Resolution Radiometer (AVHRR), bi-weekly time-composite, ormalized difference vegetation index (NDVI) data for 1998 and 1999 at a resolution of 1 km. Fourier harmonics were used to analyse the waveform of the annual NDVI profile in each pixel. To create the models, we coupled 1998 satellite phenometrics with 1998 field survey data of cuckoo presence or absence and with point data that sampled riparian and cottonwoodwillow vegetation types. Our models were verified and refined using field and satellite data collected in 1999. Results: The models reveal that cuckoos prefer areas that experience peak greenness 29 days later, are 36% more dynamic and slightly (< 1%) more productive than their average cottonwoodwillow habitat. The results support a scenario in which cuckoos migrate northwards, following the greening of riparian corridors and surrounding landscapes in response to monsoon precipitation, but then select a nesting site based on optimizing the near-term foraging potential of the neighbourhood. Main conclusions: The identification of preferred phenotypes within recognized habitat can be used to refine future habitat models, inform habitat response to climate change, and suggest adaptation strategies. For example, models of phenotype preferences can guide management actions by identifying and prioritizing for conservation those landscapes that reliably exhibit highly preferred phenometrics on a consistent basis.
Wallace, Cynthia S.; Villarreal, Miguel; Van Riper, Charles
Local habitat and landscape influence predation of bird nests on afforested Mediterranean cropland
NASA Astrophysics Data System (ADS)
Afforestation programs such as the one promoted by the EU Common Agrarian Policy have contributed to spread tree plantations on former cropland. Nevertheless these afforestations may cause severe damage to open habitat species, especially birds of high conservation value. We investigated predation of artificial bird nests at young tree plantations and at the open farmland habitat adjacent to the tree plantations in central Spain. Predation rates were very high at both tree plantations (95.6%) and open farmland habitat (94.2%) after two and three week exposure. Plantation edge/area ratio and development of the tree canopy decreased predation rates and plantation area and magpie (Pica pica) abundance increased predation rates within tree plantations, which were also affected by land use types around plantations. The area of nearby tree plantations (positive effect), distance to the tree plantation edge (negative effect), and habitat type (mainly attributable to the location of nests in vineyards) explained predation rates at open farmland habitat. We conclude that predation rates on artificial nests were particularly high and rapid at or nearby large plantations, with high numbers of magpies and low tree development, and located in homogenous landscapes dominated by herbaceous crops and pastures with no remnants of semi-natural woody vegetation. Landscape planning should not favour tree plantations as the ones studied here in Mediterranean agricultural areas that are highly valuable for ground-nesting bird species.
SÃnchez-Oliver, J. S.; Rey Benayas, J. M.; Carrascal, L. M.
Habitat influences on diversity of bacteria found on German cockroach in Beijing.
Cockroaches are worldwide indoor pests carrying microorganisms of medical importance. German cockroaches (Blattella germanica) were sampled in five habitats (hospital, restaurant, office home, and market) in Beijing, and the bacteria were isolated from their external surface and alimentary tract and identified using a Biolog identification system. Cockroach densities significantly differed among habitats (market > home > office > restaurant > hospital). However, no significant differences in bacterial abundance carried by individual German cockroaches (of either sex) were found among habitats. The bacterial abundance in the gut was significantly higher than that on the surface. There were no significant differences in bacterial species richness observed among habitats, sex, carrying position or their interaction. Cluster analysis showed that cockroach densities and bacterial abundance found in the market differed significantly from the other four habitats. The bacterial diversity was not significantly reduced in sensitive facilities such as hospital and restaurant, even though pesticide and bactericide were more frequently applied there. The implications of these findings were discussed in this article. PMID:19402430
Fu, Xue; Ye, Lefu; Ge, Feng
Respective influence of habitat conditions and management regimes on prealpine calcareous grasslands.
The calcareous grasslands of the south-western French Alps have been poorly studied, although they provide suitable habitat for rare plant species and communities. The separate and combined effects on calcareous grassland communities of habitat conditions (lithology, soil moisture) and management regimes (grazing intensity, cutting regime) were studied using constrained ordination techniques (canonical correspondence analysis with variance partitioning). Among the explanatory variables considered, the most important factor determining floristic composition was lithology, which explained 11.9% of floristic variability, followed by grazing intensity (6.0%). Additive effects of management and lithology explained 23.9% of floristic variability. Species niche amplitude was measured by conditional variances of samples along main ordination axes, in order to define adequate conservation management for the rarest short-lived species with narrow niche breadth on both habitat and management gradients. PMID:15294358
Barbaro, Luc; Dutoit, Thierry; Anthelme, Fabien; Corcket, Emmanuel
Does habitat fragmentation affect temperature-related life-history traits? A laboratory test with a woodland butterfly
Habitat fragmentation may change local climatic conditions leading to altered selection regimes for life-history traits in small ectotherms, including several insects. We investigated temperature-related performance in terms of fitness among populations of the woodland butterfly Pararge aegeria (L.) originating from populations of a closed, continuous woodland landscape versus populations of an open, highly fragmented agricultural landscape in central Belgium. Female fecundity and longevity were evaluated in a temperature-gradient experiment. As predicted, females of woodland landscape origin reached higher maximum daily fecundity and lifetime number of eggs than did agricultural landscape females at low ambient temperatures, but this reversed at high ambient temperature. Egg weight decreased with temperature, and eggs of woodland butterflies were smaller. Contrary to what is generally assumed, remaining thorax mass was a better predictor of lifetime reproductive output than was abdomen mass. Since we used the F2 generation from wild-caught females reared under common garden conditions, the observed effects are likely to rely on intrinsic, heritable variation. Our results suggest that differential selection regimes associated with different landscapes intervene by intraspecific variation in the response of a butterfly to variation in ambient temperature, and may thus be helpful when making predictions of future impacts on how wild populations respond to environmental conditions under a global change scenario, with increasing temperatures and fragmented landscapes.
Karlsson, Bengt; Van Dyck, Hans
On territorial behavior and other factors influencing habitat distribution in birds
Summary This example is provided so that non-theorists may see actual applications of the theory previously described. This study considered directly some of the components of Field Sparrow breeding success as a measure of habitat suitability, and found these to vary in a way which was inconsistent with hypotheses that territorial behavior either cues, or limits density. This study provides
Stephen Dewitt Fretwell
Abundance, Behavior, and Habitat Utilization by Coho Salmon and Steelhead Trout in Fish Creek, Oregon, as Influenced by Habitat Enhancement, 1985 Annual Report
Construction and evaluation of salmonid habitat improvements on Fish Creek, a tributary of the upper Clackamas River, was continued in fiscal year 1985 by the Estacada Ranger District, Mt. Hood National Forest, and the Anadromous Fish Habitat Research Unit of the Pacific Northwest Forest and Range Experiment Station (PNW), USDA Forest Service. The study began in 1982 when PNW entered
John Wolfe; Fred H. Everest; David A. Heller
Habitat management and patterns of predation of Northern Lapwings on wet grasslands: The influence of linear habitat structures at different spatial scales
In managed landscapes, habitat structure is frequently manipulated through the creation of features such as tracks, hedges, and waterways. If predator and prey activity are concentrated around these features, levels of predation may be elevated in these landscapes. This issue is of particular importance when habitat structures are used to attract species of conservation concern. For example, the installation of
Sarah M. Eglington; Jennifer A. Gill; Mark. A. Smart; William J. Sutherland; Andrew R. Watkinson; Mark Bolton
How life history influences population dynamics in fluctuating environments.
A major question in ecology is how age-specific variation in demographic parameters influences population dynamics. Based on long-term studies of growing populations of birds and mammals, we analyze population dynamics by using fluctuations in the total reproductive value of the population. This enables us to account for random fluctuations in age distribution. The influence of demographic and environmental stochasticity on the population dynamics of a species decreased with generation time. Variation in age-specific contributions to total reproductive value and to stochastic components of population dynamics was correlated with the position of the species along the slow-fast continuum of life-history variation. Younger age classes relative to the generation time accounted for larger contributions to the total reproductive value and to demographic stochasticity in "slow" than in "fast" species, in which many age classes contributed more equally. In contrast, fluctuations in population growth rate attributable to stochastic environmental variation involved a larger proportion of all age classes independent of life history. Thus, changes in population growth rates can be surprisingly well explained by basic species-specific life-history characteristics. PMID:24231536
Saether, Bernt-Erik; Coulson, Tim; Gr½tan, Vidar; Engen, Steinar; Altwegg, Res; Armitage, Kenneth B; Barbraud, Christophe; Becker, Peter H; Blumstein, Daniel T; Dobson, F Stephen; Festa-Bianchet, Marco; Gaillard, Jean-Michel; Jenkins, Andrew; Jones, Carl; Nicoll, Malcolm A C; Norris, Ken; Oli, Madan K; Ozgul, Arpat; Weimerskirch, Henri
Biogenic habitat transitions influence facilitation in a marine soft-sediment ecosystem.
Habitats are often defined by the presence of key species and biogenic features. However, the ecological consequences of interactions among distinct habitat-forming species in transition zones where their habitats overlap remain poorly understood. We investigated transition zone interactions by conducting experiments at three locations in Mahurangi Harbour, New Zealand, where the abundance of two habitat-forming marine species naturally varied. The two key species differed in form and function: One was a sessile suspension-feeding bivalve that protruded from the sediment (Atrina zelandica; Pinnidae); the other was a mobile infaunal urchin that bioturbated sediment (Echinocardium cordatum; Spatangoida). The experimental treatments established at each site reflected the natural densities of the species across sites (Atrina only, Echinocardium only, Atrina and Echinocardium together, and plots with neither species present). We identified the individual and combined effects of the two key species on sediment characteristics and co-occurring macrofauna. After five months, we documented significant treatment effects, including the highest abundance of co-occurring macrofauna in the Atrina-only treatments. However, the facilitation of macrofauna by Atrina (relative to removal treatments) was entirely negated in the presence of Echinocardium at densities >10 individuals/m2. The transitional areas in Mahurangi Harbour composed of co-occurring Atrina and Echinocardium are currently widespread and are probably more common now than monospecific patches of either individual species, due to the thinning of dense Atrina patches into sparser mixed zones during the last 10-15 years. Thus, although some ecologists avoid ecotones and habitat edges when designing experiments, suspecting that it will skew the extrapolation of results, this study increased our understanding of benthic community dynamics across larger proportions of the seascape and provided insights into temporal changes in community structure associated with patch dynamics. Particularly in situations where non-abrupt habitat transitions are commonplace, documentation of community dynamics in individual biogenic habitats and in mixed transition zones is required in order to scale-up and generalize results. PMID:23600248
Lohrer, Andrew M; Rodil, IvÃn F; Townsend, Michael; Chiaroni, Luca D; Hewitt, Judi E; Thrush, Simon F
Depth and medium-scale spatial processes influence fish assemblage structure of unconsolidated habitats in a subtropical marine park.
Where biological datasets are spatially limited, abiotic surrogates have been advocated to inform objective planning for Marine Protected Areas. However, this approach assumes close correlation between abiotic and biotic patterns. The Solitary Islands Marine Park, northern NSW, Australia, currently uses a habitat classification system (HCS) to assist with planning, but this is based only on data for reefs. We used Baited Remote Underwater Videos (BRUVs) to survey fish assemblages of unconsolidated substrata at different depths, distances from shore, and across an along-shore spatial scale of 10 s of km (2 transects) to examine how well the HCS works for this dominant habitat. We used multivariate regression modelling to examine the importance of these, and other environmental factors (backscatter intensity, fine-scale bathymetric variation and rugosity), in structuring fish assemblages. There were significant differences in fish assemblages across depths, distance from shore, and over the medium spatial scale of the study: together, these factors generated the optimum model in multivariate regression. However, marginal tests suggested that backscatter intensity, which itself is a surrogate for sediment type and hardness, might also influence fish assemblages and needs further investigation. Species richness was significantly different across all factors: however, total MaxN only differed significantly between locations. This study demonstrates that the pre-existing abiotic HCS only partially represents the range of fish assemblages of unconsolidated habitats in the region. PMID:24824998
Schultz, Arthur L; Malcolm, Hamish A; Bucher, Daniel J; Linklater, Michelle; Smith, Stephen D A
Depth and Medium-Scale Spatial Processes Influence Fish Assemblage Structure of Unconsolidated Habitats in a Subtropical Marine Park
Where biological datasets are spatially limited, abiotic surrogates have been advocated to inform objective planning for Marine Protected Areas. However, this approach assumes close correlation between abiotic and biotic patterns. The Solitary Islands Marine Park, northern NSW, Australia, currently uses a habitat classification system (HCS) to assist with planning, but this is based only on data for reefs. We used Baited Remote Underwater Videos (BRUVs) to survey fish assemblages of unconsolidated substrata at different depths, distances from shore, and across an along-shore spatial scale of 10 s of km (2 transects) to examine how well the HCS works for this dominant habitat. We used multivariate regression modelling to examine the importance of these, and other environmental factors (backscatter intensity, fine-scale bathymetric variation and rugosity), in structuring fish assemblages. There were significant differences in fish assemblages across depths, distance from shore, and over the medium spatial scale of the study: together, these factors generated the optimum model in multivariate regression. However, marginal tests suggested that backscatter intensity, which itself is a surrogate for sediment type and hardness, might also influence fish assemblages and needs further investigation. Species richness was significantly different across all factors: however, total MaxN only differed significantly between locations. This study demonstrates that the pre-existing abiotic HCS only partially represents the range of fish assemblages of unconsolidated habitats in the region.
Schultz, Arthur L.; Malcolm, Hamish A.; Bucher, Daniel J.; Linklater, Michelle; Smith, Stephen D. A.
Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use
Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research.
Larson, James H.; Richardson, William B.; Knights, Brent C.; Bartsch, Lynn A.; Bartsch, Michelle R.; Nelson, John C.; Veldboom, Jason A.; Vallazza, Jon M.
Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use.
Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research. PMID:23940619
Larson, James H; Richardson, William B; Knights, Brent C; Bartsch, Lynn A; Bartsch, Michelle R; Nelson, John C; Veldboom, Jason A; Vallazza, Jon M
Fatty Acid Composition at the Base of Aquatic Food Webs Is Influenced by Habitat Type and Watershed Land Use
Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research.
Larson, James H.; Richardson, William B.; Knights, Brent C.; Bartsch, Lynn A.; Bartsch, Michelle R.; Nelson, John C.; Veldboom, Jason A.; Vallazza, Jon M.
Environmental and human influences on trumpeter swan habitat occupancy in Alaska
Approximately 70-80% of the entire population of the Trumpeter Swan (Cygnus huccinator) depends for reproduction on wetlands in Alaska. This makes the identification of important habitat features and the effects of human interactions important for the species' long-term management. We analyzed the swan's habitat preferences in five areas throughout the state and found that swan broods occupied some wetland types, especially larger closed-basin wetlands such as lakes and ponds, at rates much higher than they occupied other wetland types, such as shrubby or forested wetlands. We also found a negative effect of transportation infrastructure on occupancy by broods in and around the Minto Flats State Game Refuge, Kenai National Wildlife Refuge, and Tetlin National Wildlife Refuge. This finding is of particular interest because much of the Minto Flats refuge has recently been licensed for oil and gas exploration and parts of the Kenai refuge have been developed in the past. We also investigated the potential effects of the shrinkage of closed-basin ponds on habitat occupancy by nesting Trumpeter Swans. We compared nesting swans' use of ponds with changes in the ponds' size and other characteristics from 1982 to 1996 and found no relationships between occupancy and changes in pond size. However, we believe that the recent and rapid growth of Trumpeter Swan populations in Alaska may become limited by available breeding habitat, and anthropogenic and climate-induced changes to the swan's breeding habitats have the potential to limit future production. ?? 2009 by The Cooper Ornithological Society. All rights reserved.
Schmidt, J. H.; Lindberg, M. S.; Johnson, D. S.; Schmultz, J. A.
Habitat Suitability Index Models: Common Carp.
National Technical Information Service (NTIS)
This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the...
E. A. Edwards K. Twomey
Habitat use by early life-history stages of fishes and crustaceans along a changing estuarine landscape: differences between natural and altered shoreline sites
The recent population explosion along the coastal zoneof the southeast United States and the Gulf of Mexicohas accelerated the development rate of waterfrontproperty, and particularly along the Gulf Coast ofMississippi. We compared use of pristine and alteredshoreline habitat by early life-history stages of fishand crustaceans to assess the potential effects ofthis development. Monthly beam trawls were taken at13 sites along
M. S. Peterson; B. H. Comyns; J. R. Hendon; P. J. Bond; G. A. Duff
Forestry herbicide influences on biodiversity and wildlife habitats in Southern forests.
Abstract In the southern United States, herbicide use continues to increase for timber management in commercial pine (Pinus spp.) plantations, for modifying wildlife habitats, and for invasive plant control. Several studies have reported that single applications of forestry herbicides at stand initiation have minor and temporary impacts on plant communities and wildlife habitat conditions, with some reports of enhanced habitat conditions for both game and nongame species. Due to the high resiliency of floral communities, plant species richness and diversity rebound rapidly after single herbicide treatments, with short- and long-term compositional shifts according to the selectivity and efficacy of the herbicide used. Recently, however, a shift to the Southeast in North American timber supplies has resulted in increased forest management intensity. Current site-preparation techniques rely on herbicide combinations, often coupled with mechanical treatments and >1 years of post-planting applications to enhance the spectrum and duration of vegetation control. This near-total control of associated vegetation at establishment and more rapid pine canopy closure, coupled with shortened and repeated rotations, likely will affect plant diversity and wildlife habitat quality. Development of mitigation methods at the stand and landscape levels will be required to minimize vegetative and wildlife impacts while allowing continued improvement in pine productivity. More uncertain are long-term impacts of increasing invasive plant occupation and the projected increase in herbicide use that will be needed to reverse this worsening situation. In addition, the potential of herbicides to meet wildlife management objectives in areas where traditional techniques have high social costs (e.g., prescribed fire) should be fully explored.
Miller, Karl V.
Forestry herbicide influences on biodiversity and wildlife habitat in Southern forests.
Abstract In the southern United States, herbicide use continues to increase for timber management in commercial pine (Pinus spp.) plantations, for modifying wildlife habitats, and for invasive plant control. Several studies have reported that single applications of forestry herbicides at stand initiation have minor and temporary impacts on plant communities and wildlife habitat conditions, with some reports of enhanced habitat conditions for both game and nongame species. Due to the high resiliency of floral communities, plant species richness and diversity rebound rapidly after single herbicide treatments, with short- and long-term compositional shifts according to the selectivity and efficacy of the herbicide used. Recently, however, a shift to the Southeast in North American timber supplies has resulted in increased forest management intensity. Current site-preparation techniques rely on herbicide combinations, often coupled with mechanical treatments and >1 years of post-planting applications to enhance the spectrum and duration of vegetation control. This near-total control of associated vegetation at establishment and more rapid pine canopy closure, coupled with shortened and repeated rotations, likely will affect plant diversity and wildlife habitat quality. Development of mitigation methods at the stand and landscape levels will be required to minimize vegetative and wildlife impacts while allowing continued improvement in pine productivity. More uncertain are long-term impacts of increasing invasive plant occupation and the projected increase in herbicide use that will be needed to reverse this worsening situation. In addition, the potential of herbicides to meet wildlife management objectives in areas where traditional techniques have high social costs (e.g., prescribed fire) should be fully explored.
Miller, Karl V.; Miller, James, H.
The influence of suburban land use on habitat and biotic integrity of coastal Rhode Island streams
Watershed land use in suburban areas can affect stream biota through degradation of instream habitat, water quality, and riparian\\u000a vegetation. By monitoring stream biotic communities in various geographic regions, we can better understand and conserve our\\u000a watershed ecosystems. The objective of this study was to examine the relationship between watershed land use and the integrity\\u000a of benthic invertebrate communities in
Suzanne M. Lussier; Sara N. da Silva; Michael Charpentier; James F. Heltshe; Susan M. Cormier; Donald J. Klemm; Marnita Chintala; Saro Jayaraman
Influence of small impoundments on habitat and fish communities in headwater streams
We surveyed the habitat and fish assemblages of four impounded and three unimpounded neighboring headwater streams, separated longitudinally into multiple upstream and downstream reaches. Instream habitat characteristics were similar between reaches of unimpounded streams and reaches above impoundments, and differed significantly from reaches below impoundments that included deeper water and more stable flows. Species richness was similar above and below impoundments, and between impounded and unimpounded streams, but fish assemblage composition and structure differed. Stream reaches above impoundments supported higher percentages of centrarchids compared to upper reaches of unimpounded streams, which had more obligate stream cyprinids. Reaches below impoundments supported mainly centrarchid species whereas lower reaches of unimpounded streams supported a balanced mix of cyprinids and centrarchids. Percina maculata (Blackside Darter) occurred throughout the study area except in upper reaches of impounded streams, illustrating how stream fragmentation can lead to localized extirpations. Changes to the fish assemblages in reaches above impoundments were due to the loss of downstream connectivity, and changes to the fish assemblages below impoundments were due to alterations of instream habitat caused by the impoundments. Small impoundments can have important effects on fish faunas of small geographical areas, but also potentially large cumulative effects if distribution of impoundments is not administered strategically at the scale of the river basin. We caution that continual population increase, recent droughts, and projected changes in climate patterns are prompting a renewed interest in impoundment construction, and urge close regulatory oversight over such projects.
Kashiwagi, M. T.; Miranda, L. E.
Health Related Quality of Life and Influencing Factors among Welders
Background Occupational exposure to welding fumes is a serious occupational health problem all over the world. Welders are exposed to many occupational hazards; these hazards might cause some occupational diseases. The aim of the study was to assess the health related quality of life (HRQL) of electric welders in Shanghai China and explore influencing factors to HRQL of welders. Methods 301 male welders (without pneumoconiosis) and 305 non-dust male workers in Shanghai were enrolled in this study. Short Form-36 (SF-36) health survey questionnaires were applied in this cross-sectional study. Socio-demographic, working and health factors were also collected. Multiple stepwise regress analysis was used to identify significant factors related to the eight dimension scores. Results Six dimensions including role-physical (RP), bodily pain (BP), general health (GH), validity (VT), social function (SF), and mental health (MH) were significantly worse in welders compared to non-dust workers. Multiple stepwise regress analysis results show that native place, monthly income, quantity of children, drinking, sleep time, welding type, use of personal protective equipment (PPE), great events in life, and some symptoms including dizziness, discomfort of cervical vertebra, low back pain, cough and insomnia may be influencing factors for HRQL of welders. Among these factors, only sleep time and the use of PPE were salutary. Conclusions Some dimensions of HRQL of these welders have been affected. Enterprises which employ welders should take measures to protect the health of these people and improve their HRQL.
Qin, Jingxiang; Liu, Wuzhong; Zhu, Jun; Weng, Wei; Xu, Jiaming; Ai, Zisheng
Hydrologic Reconnaissance of Wetland-Bird Habitat in Areas With Potential to be Influenced by Water Produced During Coalbed Methane Production in the Northern Powder River Basin, MT
NASA Astrophysics Data System (ADS)
The removal and disposal of ground water during production of coalbed methane has the potential to influence wetland-bird habitat in the Powder River Basin. Office analysis of wetland areas was conducted on National Wetland Inventory maps and Digital Orthophoto Quadrangles along the Tongue and Powder rivers in the northern Powder River Basin, Montana. Selected sites were palustrine emergent, large enough to be important to waterbirds, part of a wetland complex, not dependent on artificial water regimes, in an area with high potential for coalbed methane production, and judged to be accessible in the field. Several promising wetland areas were selected for field examination. Field investigation suggests that the most promising wetlands in oxbow cutoffs would not be productive sites. Only facultative not obligate wetland plants were observed, the topographic position of the wetlands suggested that flooding would be infrequent, and the stream flow would likely dilute the effect of produced water adjacent to these rivers. Fortuitously wetland-bird habitat not recognized on the National Wetland Inventory maps and Digital Orthophoto Quadrangles was observed along Rosebud Creek during the field reconnaissance. This habitat is not continuous. The lack of continuity is reflected in the soil surveys as well as in the reconnaissance field nvestigation. The Alluvial Land soil series corresponds to observed wetland areas but the extent of the wetland-bird habitat varies substantially within the soil unit. When the Korchea series is present, extensive wetland-bird habitat is not observed. Field and aerial photo analysis suggests that the presence of the habitat may be controlled by beaver, and/or by stratigraphic and structural elements that influence stream erosion. Human modification of the stream for irrigation purposes may impact habitat continuity in some areas. The "Rosebud" type wetland-bird habitat may have the potential to be influenced by coalbed methane water production and warrants further more detailed investigation to determine the areal extent of the habitat, to determine the factors that control the distribution of intermittent wetland-bird-habitat areas, and to better model whether and how water produced during coalbed methane development might influence wetland-bird habitat.
Custer, S. G.; Sojda, R. S.
Bull trout life history, genetics, habitat needs, and limiting factors in central and northeast Oregon, annual report 1998.
National Technical Information Service (NTIS)
This section describes work accomplished in 1998 that continued to address two objectives of this project. These objectives are 1) determine the distribution of juvenile and adult bull trout and habitats associated with that distribution, and 2) determine...
A. R. Hemmingsen B. L. Bellerud S. L. Gunckel
Survival and development of the different life stages of Ixodes scapularis (Acari: Ixodidae) held within four habitats on Long Point, Ontario, Canada.
From November 1989 to April 1993, blood-fed females and unfed adults and nymphs of lxodes scapularis Say were maintained in housings within 4 different habitats on Long Point, Ontario, Canada, to evaluate the effects of habitat on tick development. More fed females survived the winter within the maple forest (75.6%) than the cottonwood dune (36.1%), whereas 52.8-62.0% survived the winter within the 2 remaining habitats. The proportions of females that laid eggs within the maple forest (90.3%), oak savannah (83.9%), and white pine habitats (78.4%) were similar and greater than in the cottonwood dune (53.8%). In each habitat and all years, females began laying eggs during late April or early May. The time of egg deposition was consistent whether females fed in November and overwintered, or fed during April of the subsequent year. Significantly more eggs hatched within the maple forest (96.4%) and white pine (79.3%) than in the oak savannah (3.8%) or cottonwood dune habitats (0.0%). Hatch occurred in mid- to late July each year. The proportion of unfed I. scapularis adults that survived the winter was not significantly different among the 4 habitats. Unfed adults held in the oak savannah and cottonwood dune habitats died by early June, whereas ticks survived until late June or early July within the maple forest and white pine habitats. Unfed nymphs survived an average of 3.4 mo (range, 0.5-5.5) longer than unfed adults. Fed larvae placed in the field from 22 April to 3 July 1992 molted or died that year. In contrast, 66.7 and 100% of fed larvae placed in the field between 15 and 28 July, and after 28 July, respectively, overwintered before molting. More larvae successfully molted before overwintering (46.9%) than did those that overwintered (17.9%). The proportion of larvae that successfully molted was greatest within the maple forest and least within the cottonwood dune. Fed nymphs placed in the field from 22 April to 4 June molted or died in 1992, whereas 53.6 and 99.2% of fed nymphs placed in the field between 17 June and 28 July, and later than 28 July, respectively, overwintered before molting. Over all habitats, the proportion of nymphs that molted successfully was similar for those that overwintered (43.5%) and those that did not (36.0%). The proportion of nymphs that molted successfully was greatest in the maple forest (60.6%) and least within the cottonwood dune (13.3%). Differences in seasonal extremes of vapor pressure deficits among habitat types were likely responsible for habitat-specific differences in survival of I. scapularis. Based on observations on captive I. scapularis, the life cycle of this tick on Long Point is completed in 3 or 4 yr. PMID:9615533
Lindsay, L R; Barker, I K; Surgeoner, G A; McEwen, S A; Gillespie, T J; Addison, E M
Deep-sea habitat heterogeneity influence on meiofaunal communities in the Gulf of Guinea
NASA Astrophysics Data System (ADS)
To estimate the degree of spatial heterogeneity of benthic deep-sea communities, we carried out a multiple-scale (from m's to 200 km) investigation in the Congo-Angola margins (Equatorial West African margin, 3150-4800 m) in which we examined the metazoan meiofauna at a variety of habitats along the Congo Channel system and in the associated cold seep. We investigate the structure, density, vertical distribution patterns in the sediment and biomass of meiofaunal communities in the Gulf of Guinea and how they are controlled by hydrologic and biogeochemical processes. The meiofaunal communities in the Gulf of Guinea were shaped by heterogeneous conditions on the margin, and reflect the multiple-scale spatial variability that corresponds with the different identified habitats. The two control sites, located at >100 km away from the canyon, were inhabited by very dense and the most diverse meiobenthic communities. Similar meiobenthic communities inhabited the transition zone between the canyon and the cold seep. Sites located along the Congo Channel were obviously affected by the local high-velocity bottom currents and unstable sedimentary conditions in this active submarine system. Extremely low meiobenthic densities and very low proportions in the most surficial sediment layers provided evidence for recently highly disturbed sediments at these sites. The remote operated vehicle (ROV) Victor 6000 provided images of the cold seep, showing a patchy distribution of several types of patchy distributed megafaunal communities dominated by three key symbiotic taxa (Mytilidae, Vesicomyidae and Siboglinidae). These cold seep sediments were colonised by a unique meiobenthic community, characterised by a high small-scale (m's) patchiness, low species richness and the prominent dominance of two large-sized nematode species: Sabatieria mortenseni, which is a cosmopolitan nematode known from littoral habitats, and an undescribed Desmodora species. The high individual body weight of S. mortenseni and its dominance at the cold seep site resulted in a significantly higher nematode biomass at the seep compared to the surrounding sites. In addition, the vertical nematode profiles, with maximum proportions in subsurficial layers, points to a chemosynthesis-based meiobenthic community in this cold seep, in contrast to the phytodetritus-based communities at the control sites and at the transition zone.
Van Gaever, Saskia; GalÕron, JoŠlle; Sibuet, Myriam; Vanreusel, Ann
Earth is a Marine Habitat. Habitat Conservation Program.
ERIC Educational Resources Information Center
This brochure is intended to educate the public about the need to conserve and preserve the earth's environment (man's habitat). It contains an introduction to the ocean world and threats to coastal habitat. Photos and narrative revolve around the theme "Earth is a Marine Habitat." Sections include: "The Web of Life,""Oceans and the United
National Oceanic and Atmospheric Administration (DOC), Rockville, MD.
Geographic and habitat origin influence biomass production and storage translocation in the clonal plant Aegopodium podagraria.
Through physiological integration, clonal plants can support ramets in unfavourable patches, exploit heterogeneously distributed resources and distribute resources that are taken up over large areas. Physiological integration generally increases in adverse conditions, but it is not well known which factors determine the evolution of physiological integration. The aim of this study was to investigate if clonal plants from Southern and Northern populations of the clonal herb Aegopodium podagraria differed in physiological integration in terms of translocation of carbon to the rhizomes, and in biomass production using a reciprocal transplant experiment. Aegopodium podagraria from shaded conditions have been suggested to share more resources than clones from open conditions and therefore, plants from forest and open populations within the Southern and Northern regions were included. The regional growing conditions greatly affected biomass production. Plants grown in North Sweden produced more biomass and allocated more biomass to shoots, while plants grown in South Sweden allocated more biomass to rhizomes. There was a regional origin effect as plants originating from North Sweden produced more biomass in both regions. Within the Northern region, plants from shaded habitats translocated more (14)C to the rhizomes, suggesting more storage there than in plants from open habitats. In addition to genetic differentiation in biomass production between Northern and Southern populations, probably as a response to a shorter growing season in the North, there appeared to be genetic differentiation in physiological integration within the Northern region. This shows that both regional and local conditions need to be taken into account in future studies of genetic differentiation of physiological integration in clonal plants. PMID:24427305
D'Hertefeldt, Tina; Enestr—m, Johanna M; Pettersson, Lars B
Human Disturbance and Stage-Specific Habitat Requirements Influence Snowy Plover Site Occupancy during the Breeding Season.
National Technical Information Service (NTIS)
Habitat use has important consequences for avian reproductive success and survival. In coastal areas with recreational activity, human disturbance may limit use of otherwise suitable habitat. Snowy plovers Charadrius nivosus have a patchy breeding distrib...
A. F. Webber, J. A. Heath, R. A. Fischer
Review of hydrographic environmental factors that may influence anchovy habitats in northwestern Mediterranean
SUMMARY: This paper is a review of the hydrography of the northwestern Mediterranean. It examines, at several scales from basin-scale to local processes, water mass distribution, circulation and driving mechanisms and their variability. It is focused on those aspects that may influence the success of spawning and recruitment of anchovy: stratification processes, continental influence, frontal instabilities, mesoscale events and shelf-slope
Habitat and phylogeny influence salinity discrimination in crocodilians: implications for osmoregulatory physiology and historical biogeography
Crocodylids are better adapted than alligatorids, through a suite of morphological specializations, for life in hyperosmotic environments. The presence of such specializations even in freshwater crocodylids has been interpreted as evidence for a marine phase in crocodylid evolution, consistent with the trans-osceanic migration hypothesis of crocodilian biogeography. The ability to discriminate fresh water from hyperosmotic sea water, and to avoid
Root endophyte and mycorrhizosphere fungi of black spruce, Picea mariana, in a boreal forest habitat: influence of site factors on fungal distributions
In a study of fungi growing in various root-associated habitats in and around Picea mariana, black spruce, in northern Ontario, Canada, an examination was made of the degree to which differences in growth sites within an area of a few square kilometers might influence the structure of root-associated filamentous microfungal populations. Picea mariana roots were collected at four strongly differing
Richard C. Summerbell
Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover
The Karner blue butterfly Lycaeides melissa samuelis is an endangered species residing in the Great Lakes and northeastern regions of the United States. Increased canopy cover is a major factor implicated in the decline of the Karner blue at many locales. Therefore, we examined how the butterfly's behavior varied with canopy cover. Adult males at Indiana Dunes National Lakeshore used habitat under canopy openings for nearly 90% of their activities; females used openings and shaded areas more equally. The frequency of oviposition on the sole host plant, wild lupine Lupinus perennis, was highest under 30-60% canopy cover even though lupine was more abundant in more open areas. Larvae fed preferentially on larger lupine plants and on lupines in denser patches. However, lupines were generally larger in the shade. Therefore, shade-related trade-offs existed between lupine abundance and distribution of larval feeding and oviposition. Also, heterogeneity of shading by sub-canopy woody vegetation was greater at oviposition sites than at sites where lupine did not grow. Given the importance of shade heterogeneity, a mixture of canopy openings and shade, on a scale similar to daily adult movement range, should be beneficial for this butterfly.
Grundel, R.; Pavlovic, N. B.; Sulzman, C. L.
Habitat use by the endangered Karner blue butterfly in oak woodlands: The influence of canopy cover
The Karner blue butterfly Lycaeides melissa samuelis is an endangered species residing in the Great Lakes and northeastern regions of the United States. Increased canopy cover is a major factor implicated in the decline of the Karner blue at many locales. Therefore, we examined how the butterfly's behavior varied with canopy cover. Adult males at Indiana Dunes National Lakeshore used habitat under canopy openings for nearly 90% of their activities; females used openings and shaded areas more equally. The frequency of oviposition on the sole host plant, wild lupine Lupinus perennis, was highest under 30-60% canopy cover even though lupine was more abundant in more open areas. Larvae fed preferentially on larger lupine plants and on lupines in denser patches. However, lupines were generally large in the shade. Therefore, shade-related trade-offs existed between lupine abundance and distribution of larval feeding and oviposition. Also, heterogeneity of shading by sub-canopy woody vegetation was greater at oviposition sites than at sites where lupine did not grow. Given the importance of shade heterogeneity, a mixture of canopy opening and shades, on a scale similar to daily adult movement range, should be beneficial for this butterfly.
Grundel, Ralph; Pavlovic, Noel B.; Sulzman, Christina L.
Does Autocthonous Primary Production Influence Oviposition by Aedes japonicus japonicus (Diptera: Culicidae) in Container Habitats?
Aedes (Finlaya) japonicus japonicus (Theobald) (Diptera: Culicidae) is recently invasive in North America and has expanded its range rapidly since 1998. Throughout its native and expanded range, Ae. j. japonicus larvae are commonly observed in many types of natural and artificial water-filled containers that vary in organic matter content and exposure to sunlight. Larvae are most often found in containers with decaying leaf material or algae, and we postulated that the added autocthonous primary production from algae could be both an important food source for larvae and an influential oviposition attractant to adult Ae. j. japonicus. We tested this hypothesis by placing plastic containers with varied levels of shading to manipulate algal density in the field, and then monitored oviposition by natural populations of Ae. j. japonicus. Over 99% of larvae hatching from eggs laid on the walls of our containers were Ae. j. japonicus, indicating that this species is a dominant colonizer of artificial containers in the study areas. Although full shading treatments effectively reduced algal biomass (significant reduction in chlorophyll a levels), at only one of three sites did this appear to affect Ae. j. japonicus oviposition. We conclude that algae in larval habitats are not a major factor in oviposition choices of adult Ae. j. japonicus females except when in situ primary production is high enough to substantially alter overall organic matter content cues.
Adaptive maintenance of genetic polymorphism in an intertidal barnacle: habitat- and life-stage-specific survivorship of Mpi genotypes.
In the northern acorn barnacle, Semibalanus balanoides, genotype frequencies of three genetic markers were tracked over time in four types of intertidal habitats. These habitats were selected to represent natural variation in several environmental parameters, specifically the degree of physical stress experienced by barnacles. Frequencies for one allozyme locus (Gpi) and a presumably neutral mtDNA marker were homogeneous among habitats in each temporal sample. Similarly, no temporal stratification in genotype frequencies was evident across the five sampling intervals: from planktonic larvae sampled in March to juveniles collected at the end of June. In contrast to the Gpi and mtDNA loci, Mpi genotypes significantly changed in frequency in two habitats in the high intertidal zone. On exposed substrate, the Mpi-FF homozygote increased in frequency, whereas the alternative homozygote, Mpi-SS, significantly decreased in frequency. Barnacles that were protected from environmental stress at high intertidal heights by the Ascophyllum nodosum algal canopy demonstrated the opposite pattern. In both habitats, the change in frequency of the heterozygote was intermediate to that of the homozygous genotypes. Furthermore, these patterns of genotype-by-environment association reflected a pulse of genotype-specific mortality that occurred over a two-week interval subsequent to metamorphosis from the larval to the adult form. These data indicate that each Mpi homozygote is the highest fitness genotype in some portion of the intertidal environment. Using the Levene (1953) model to evaluate the spatial variation in genotypic fitness, the stable maintenance of the Mpi polymorphism is predicted under certain subsets of conditions. Environmental heterogeneity in the intertidal zone translates to spatial variation in selection pressures, which may result in the active maintenance of the Mpi polymorphism in this species. PMID:11525458
Schmidt, P S; Rand, D M
Habitat manipulation of Exposed Riverine Sediments (ERS) how does microhabitat, microclimate and food availability influence beetle distributions?
NASA Astrophysics Data System (ADS)
Exposed riverine sediments (ERS) are frequently inundated areas of relatively un-vegetated, fluvially deposited sediment (sand, silt, gravel and pebble). These habitats provide an important interface allowing the interaction of aquatic and terrestrial habitats and species. ERS are highly valuable for many rare and specialist invertebrates particularly beetles. Within an area of ERS, beetle species richness tends to be highest along the water's edge. This higher species richness may be linked to: (1) the availability of food items in the form of emerging and stranded aquatic invertebrates and (2) favourable physical microhabitat conditions in terms of temperature and moisture. This paper explores the role of microclimate and food availability by creating areas of water's edge' habitat in the centre of a gravel bar. Typically these areas are drier, reach higher temperatures and devoid of emerging aquatic invertebrate prey. Four 2m x 2m experimental plots were created: one wet plot, one wet- fed plot, one dry-fed plot and one dry plot (control). These plots were each replicated on three separate areas of ERS. Sixty colour marked ERS specialist ground beetles (Bembidion atrocaeruleum) were released into each plot to monitor beetle persistence and movement on and between plots. The plots were maintained wet using a capillary pump system, and fed with dried blood worms for 30 days. Sediment temperature (0.05 m depth) was measured at 15 minute intervals and spot measurements of surface temperature were taken daily. A hand search was carried out on 25% of each plot after 7, 14, 21 and 30 days. Significant temperature differences were observed between the wet and dry sediment and air temperature. The wet plots on average were 1.8oC cooler than the dry plots and had a reduced temperature range. Both wet and dry sediments remained significantly warmer than air temperature. The wet and wet-fed plots yielded significantly greater numbers of beetles and marked beetles than the dry and dry-fed plots; however, no significant difference was found between the wet and wet-fed plots. These results indicate that microhabitat in terms of increased moisture and lower temperature is the driving factor influencing beetle distribution and movement. Food alone is not as influential. ERS carabid beetles may be using lower temperatures and increased moisture as a cue for aquatic food availability.
Henshall, S. E.; Sadler, J. P.; Hannah, D. M.
The influence of habitat, season and tidal regime in the activity of the intertidal crab Neohelice (= Chasmagnathus) granulata
NASA Astrophysics Data System (ADS)
The activity pattern of intertidal crabs is influenced by factors that usually change rhythmically following tidal and/or diel cycles, and is often associated with the use of refuges. The movement activity of the burrowing crab Neohelice granulata was compared among three populations from SW Atlantic coastal areas where they face different tidal regimes, water salinities, substrata and biological factors. At each site, we examined the seasonal activity of the crabs (individuals collected in pitfall traps) in two types of habitat: mudflat and salt marsh. The working hypothesis is that the activity would vary according to the diverse environmental conditions encountered at geographical and local scales. Crab activity varied between sites and seasons showing to be more intense when habitats were covered by water. The most active groups were large males, followed by large non-ovigerous females. Ovigerous females were almost inactive. Most crabs were near or inside burrows at low tides in Mar Chiquita and BahÚa Blanca, but they were active at both low and high tides in San Antonio during spring and summer. N. granulata were active in a wide range of temperatures: from 10 to 37 ¯C at low tides and at temperatures as low as 2 ¯C when covered by water. Differences of activity between mudflat and salt marsh varied among sites depending on flooding frequencies. Movement activity of N. granulata varied both in space and in time; crabs move under very different abiotic conditions (e.g., low or high tide, daylight or night, low and high temperature) and their movement may also be prevented or elicited by biotic conditions like burrow complexity, food quality and predation pressure. The wide set of conditions under which N. granulata can be active may explain why this is the only semiterrestrial crab inhabiting latitudes higher than 40¯S in South America.
Luppi, TomÃs; Bas, Claudia; MÕndez Casariego, Agustina; Albano, Mariano; Lancia, Juan; Kittlein, Marcelo; Rosenthal, Alan; FarÚas, Nahuel; Spivak, Eduardo; Iribarne, Oscar
Diversity in skeletal architecture influences biological heterogeneity and Symbiodinium habitat in corals.
Scleractinian corals vary in response to rapid shifts in the marine environment and changes in reef community structure post-disturbance reveal a clear relationship between coral performance and morphology. With exceptions, massive corals are thought to be more tolerant and branching corals more vulnerable to changing environmental conditions, notably thermal stress. The typical responses of massive and branching coral taxa, respectively, are well documented; however, the biological and functional characteristics that underpin this variation are not well understood. We address this gap by comparing multiple biological attributes that are correlated with skeletal architecture in two perforate (having porous skeletal matrices with intercalating tissues) and two imperforate coral species (Montipora aequituberculata, Porites lobata, Pocillopora damicornis, and Seriatopora hystrix) representing three morphotypes. Our results reveal inherent biological heterogeneity among corals and the potential for perforate skeletons to create complex, three-dimensional internal habitats that impact the dynamics of the symbiosis. Patterns of tissue thickness are correlated with the concentration of symbionts within narrow regions of tissue in imperforate corals versus broad distribution throughout the larger tissue area in perforate corals. Attributes of the perforate and environmentally tolerant P. lobata were notable, with tissues ?5 times thicker than in the sensitive, imperforate species P. damicornis and S. hystrix. Additionally, P. lobata had the lowest baseline levels of superoxide and Symbiodinium that provisioned high levels of energy. Given our observations, we hypothesize that the complexity of the visually obscured internal environment has an impact on host-symbiont dynamics and ultimately on survival, warranting further scientific investigation. PMID:23992772
Yost, Denise M; Wang, Li-Hsueh; Fan, Tung-Yung; Chen, Chii-Shiarng; Lee, Raymond W; Sogin, Emilia; Gates, Ruth D
Recent undesirable life events: Their influence on subsequent psychopathology
Summary Life events appear to exert a range of effects on subsequent behaviour through their impact on affective-cognitive processes. Their effects on those physiological processes pertinent to psychopathology have yet to be investigated. Single events do not exert much risk for subsequent disorder. It is the pattern of adverse life experiences, of which recent life events is frequently a component,
I. M. Goodyer
Genetic and Environmental Influences on Negative Life Events from Late Childhood to Adolescence
ERIC Educational Resources Information Center
This multiwave longitudinal study tested two quantitative genetic developmental models to examine genetic and environmental influences on exposure to negative dependent and independent life events. Participants (N = 457 twin pairs) completed measures of life events annually from ages 9 to 16. The same genetic factors influenced exposure to
Johnson, Daniel P.; Rhee, Soo Hyun; Whisman, Mark A.; Corley, Robin P.; Hewitt, John K.
Habitability: where lo look for life? Halophilic habitats: earth analogs to study Mars and Europàs habitability
Current Mars exploration is producing a considerable amount of information which requires comparison with terrestrial analogs in order to interpret and evaluate compatibility with possible extinct and\\/or extant life on the planet. The first astrobiological mission specially designed to detect life on Mars, the Viking missions, thought life unlikely, considering the amount of UV radiation bathing the surface of the
F. Gµmez; J. Gµmez-Elvira; N. RodrÚguez; J. F. Caballero Castrejµn; R. Amils; J. A. RodrÚguez-Manfredi
Influence of Life Style Factors on Barrett's Oesophagus
Background. Since the incidence of adenocarcinoma of the oesophagus is rising, the prognosis is poor, and surveillance programs are expensive and mostly cost ineffective, there is a need to increase the knowledge of risk factors in Barrett's oesophagus and oesophageal cancer in order to be able to give attention to medical prevention and/or surveillance programs. Aim. To study if there is a correlation between the development of Barrett's oesophagus and GOR (gastro oesophageal reflux), family history of GOR, and life style factors, such as alcohol, smoking habits, and mental stress. Methods. Fifty-five consecutively selected patients with Barrett's oesophagus (BO) examined at Link—ping University Hospital's Oesophageal Laboratory were matched by sex, age, and duration of reflux symptoms with 55 GOR patients without Barrett's oesophagus at the Oesophageal Laboratory. The medical charts in respective groups were examined for comparison of life style factors, mental stress, medication, duration of gastroesophageal acid reflux at 24?hr-pH-metry, and incidence of antireflux surgery and of adenocarcinoma of the oesophagus (ACO). Also, potential gender differences and diagnosis of ACO were studied. Results. Mean percentage reflux time on 24?hr-pH-metry was higher for the Barrett's oesophagus group, 18% for women and 17% for men compared to 4% for women and 4% for men in the control group (P < 0.05). Family history of GOR was more frequent in Barrett's oesophagus patients (62%) than in the control group (35%) (P < 0.05). Male patients with Barrett's oesophagus had medical therapy for their GOR symptoms to a higher extent (38%) than male controls (65%) (P < 0.05). No difference was found in the number of tobacco users or former tobacco users between Barrett's oesophagus patients and controls. Barrett's oesophagus patients had the same level of alcohol consumption and the same average BMI as the control subjects. Female patients with Barrett's oesophagus rated themselves as more mentally stressed (67%) than the female controls (38%) (P < 0.05). In the five-year medical chart follow-up, five of 55 patients developed adenocarcinoma among the Barrett's oesophagus patients, none in the control group. Conclusions. Long reflux time and family clustering of GOR seem to influence the development of Barrett's oesophagus. Smoking habits, alcohol consumption and BMI do not seem to have any impact on the development of Barrett's oesophagus.
Horna Strand, A.; Franzen, T.
Habitat alteration is well recognized as a major cause of loss of living aquatic resources. Many fish and wildlife species depend on several habitats (or on habitat landscapes) in their life histories and migratory patterns. This NHEERL habitat research will develop stressor-re...
50 CFR 17.95 - Critical habitat-fish and wildlife.
Code of Federal Regulations, 2012 CFR
...behavior, growth, and viability of all life stages. (3) Critical habitat does...behavior, growth, and viability of all life stages. (3) Critical habitat does...behavior, growth, and viability of all life stages. (3) Critical habitat...
Types of habitat in the Universe
NASA Astrophysics Data System (ADS)
From a biological point of view, all environments in the Universe can be categorized into one of three types: uninhabitable, uninhabited habitat or inhabited habitat. This paper describes and defines different habitat types in the Universe with a special focus on environments not usually encountered on the Earth, but which might be common on other planetary bodies. They include uninhabited habitats, subtypes of which are sterile habitats and organic-free habitats. Examples of the different types of environments are provided with reference to the Eyjafjallaj—kull, Iceland. These habitat types are used to identify testable hypotheses on the abundance of different habitats and the distribution of life in the Universe.
Cockell, Charles S.
Investigating the Impact of UV Radiation on High-Altitude Shallow Lake Habitats, Life Diversity, and Life Survival Strategies: Clues for Mars' Past Habitability Potential?
NASA Technical Reports Server (NTRS)
We present data and results from an ongoing project of astrobiological high-altitude expeditions investigating the highest and least explored perennial lakes on Earth in the Bolivian and Chilean Andes, including several volcanic crater lakes nearing and beyond 6,000 m in elevation. In the next five years, they will provide the first integrated long-term astrobiological characterization and monitoring of lacustrine environments and their biology for such altitude. These extreme lakes are natural laboratories. They provide the field data missing beyond 4,000 m to complete our understanding of terrestrial lakes and biota. Research on the effects of UV has been performed in lower altitude lakes and models of UV flux over time are being developed. Lakes showing a high content of dissolved organic material (DOM) shield organisms from UV. DOM acts as a natural sunscreen as it influences the water transparency, therefore is a determinant of photic zone depth. In sparsely vegetated alpine areas, lakes are clearer and offer less protection from UV to organisms living in the water. Transparent water and high UV irradiance may maximize the penetration and effect of UV radiation. Shallow-water communities in these lakes are particularly sensitive to UV radiation. The periphyton can live on various susbtrates. While on rocks, it includes immobile species that cannot seek low UV refuges unlike sediment-dwelling periphyton or alpine phytoflagellates which undergo vertical migration. Inhibition of algal photosynthesis by UV radiation has been documented in laboratory and showed that phytoplankton production is reduced by formation of nucleic acid lesions or production of peroxides and free oxygen radicals. of peroxides and free oxygen radicals. Our project is providing the field data that is missing from natural laboratories beyond 4,000 m and will complement the vision of the effects of UV on life and its adaptation modes (or lack thereof).
Cabrol, A.; Grin, E. A.; Hock, A.; Kiss, A.; Borics, G.; Kiss, K.; Acs, E.; Kovacs, G.; Chong, G.; Demergasso, C.
The influence of habitats on female mobility in Central and Western Africa inferred from human mitochondrial variation
Background When studying the genetic structure of human populations, the role of cultural factors may be difficult to ascertain due to a lack of formal models. Linguistic diversity is a typical example of such a situation. Patrilocality, on the other hand, can be integrated into a biological framework, allowing the formulation of explicit working hypotheses. The present study is based on the assumption that patrilocal traditions make the hypervariable region I of the mtDNA a valuable tool for the exploration of migratory dynamics, offering the opportunity to explore the relationships between genetic and linguistic diversity. We studied 85 Niger-Congo-speaking patrilocal populations that cover regions from Senegal to Central African Republic. A total of 4175 individuals were included in the study. Results By combining a multivariate analysis aimed at investigating the population genetic structure, with a Bayesian approach used to test models and extent of migration, we were able to detect a stepping-stone migration model as the best descriptor of gene flow across the region, with the main discontinuities corresponding to forested areas. Conclusions Our analyses highlight an aspect of the influence of habitat variation on human genetic diversity that has yet to be understood. Rather than depending simply on geographic linear distances, patterns of female genetic variation vary substantially between savannah and rainforest environments. Our findings may be explained by the effects of recent gene flow constrained by environmental factors, which superimposes on a background shaped by pre-agricultural peopling.
The Influence of Roads and Buffer Depth on Habitat Core Areas and Connectivity in the NE USA
NASA Astrophysics Data System (ADS)
Land development pressures that threaten habitat core areas and connectivity are intensifying across the nation and extending beyond urbanized areas in the form of rural residential development. This is particularly true in the temperate forests of the northeastern U.S. If current trends continue, increased conversion and fragmentation of many roadless areas by exurban development is likely, exacerbating the likelihood of local species extinctions and complicating efforts to preserve intact functional ecosystems. We used a suite of nationally available data sets to identify roadless areas of the northeastern USA including impervious cover (urbanized and developed areas), road networks (and derived density), and forest cover (canopy density). We analyzed the influence of different types of unimproved roads and amount of forest cover on identification of the extent and configuration of roadless areas, and then assessed these areas in terms of land ownership (public, private) and management (parks, refuges, multi-use, etc.). We also derived patch connectivity metrics using a graph theory approach, making use of cost surfaces that accounted for the above variables and associated landscape metrics. Our results suggest a starting point for the construction of a more comprehensive and ecologically functional reserve network for the region. Because the data sets we used are available nationally, similar analyses could be conducted to assess the extent and status of roadless areas nationally or for other specific regions.
Jantz, P.; Goetz, S.
Regional, Habitat, and Human Development Influences on Coastal Wetland and Beach Fish Assemblages in Green Bay, Lake Michigan
High levels of coastal wetland degradation, limited knowledge of fishes that utilize these habitats, and the potentially high ecological importance of coastal wetlands in Great Lakes ecosystems all provided an impetus to characterize fish assemblages associated with coastal wetland and other littoral habitats in Green Bay, Lake Michigan. From May to September 1990 and 1991, I sampled 24 coastal wetland
John C. Brazner
Influence of cyclic strain on life of a PVD TBC
A thermal mechanical fatigue (TMF) test has been developed to determine the effect of strain on the life of a thermal barrier coating. TMF tests were performed with different temperaturestrain phasing and different applied strain levels to vary the imposed strain range on the coating and thus separate strain dependence of life from oxidation effects. Results for a single crystal
P Kennard Wright
Terrestrial habitat selection and strong density-dependent mortality in recently metamorphosed amphibians.
To predict the effects of terrestrial habitat change on amphibian populations, we need to know how amphibians respond to habitat heterogeneity, and whether habitat choice remains consistent throughout the life-history cycle. We conducted four experiments to evaluate how the spatial distribution of juvenile wood frogs, Rana sylvatica (including both overall abundance and localized density), was influenced by habitat choice and habitat structure, and how this relationship changed with spatial scale and behavioral phase. The four experiments included (1) habitat manipulation on replicated 10-ha landscapes surrounding breeding pools; (2) short-term experiments with individual frogs emigrating through a manipulated landscape of 1 m wide hexagonal patches; and habitat manipulations in (3) small (4-m2); and (4) large (100-m2) enclosures with multiple individuals to compare behavior both during and following emigration. The spatial distribution of juvenile wood frogs following emigration resulted from differences in the scale at which juvenile amphibians responded to habitat heterogeneity during active vs. settled behavioral phases. During emigration, juvenile wood frogs responded to coarse-scale variation in habitat (selection between 2.2-ha forest treatments) but not to fine-scale variation. After settling, however, animals showed habitat selection at much smaller scales (2-4 m2). This resulted in high densities of animals in small patches of suitable habitat where they experienced rapid mortality. No evidence of density-dependent habitat selection was seen, with juveniles typically choosing to remain at extremely high densities in high-quality habitat, rather than occupying low-quality habitat. These experiments demonstrate how prediction of the terrestrial distribution of juvenile amphibians requires understanding of the complex behavioral responses to habitat heterogeneity. Understanding these patterns is important, given that human alterations to amphibian habitats may generate extremely high densities of animals, resulting in high density-dependent mortality. PMID:18831177
Patrick, David A; Harper, Elizabeth B; Hunter, Malcolm L; Calhoun, Aram J K
Ribbon of Life: An Agenda for Preserving Transboundary Migratory Bird Habitat on the Upper San Pedro River
NSDL National Science Digital Library
The Commission for Environmental Cooperation (CEC) has released this report "to foster cooperative efforts to ensure the continued health of the San Pedro Watershed." Over the past century, the ecological integrity of the Upper San Pedro River has declined substantially; the loss of riparian habitat has important implications for migratory birds. The report (.pdf format), which may be downloaded at the site, calls for coordinated management of the watershed, further research in certain key areas, greater collaboration among stakeholders, and increased public education efforts.
Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem.
When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August-30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000-2011. We calculated Manly-Chesson (MC) indices for selectivity of WBP habitat and secure habitat (?500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas. PMID:24963393
Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D
Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem
When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 20002011. We calculated ManlyChesson (MC) indices for selectivity of WBP habitat and secure habitat (?500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas.
Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D
The influence of litter quality and micro-habitat on litter decomposition and soil properties in a silvopasture system
NASA Astrophysics Data System (ADS)
Studies to understand litter processes and soil properties are useful for maintaining pastureland productivity as animal husbandry is the dominant occupation in the hot arid region. We aimed to quantify how micro-habitats and combinations of litters of the introduced leguminous tree Colophospermum mopane with the grasses Cenchrus ciliaris or Lasiurus sindicus influence decomposition rate and soil nutrient changes in a hot desert silvopasture system. Litter bags with tree litter alone (T), tree + C. ciliaris in 1:1 ratio (TCC) and tree + L. sindicus 1:1 ratio (TLS) litter were placed inside and outside of the C. mopane canopy and at the surface, 3-7 cm and 8-12 cm soil depths. We examined litter loss, soil fauna abundance, organic carbon (SOC), total (TN), ammonium (NH4-N) and nitrate (NO3-N) nitrogen, phosphorus (PO4-P), soil respiration (SR) and dehydrogenase activity (DHA) in soil adjacent to each litter bag. After 12 months exposure, the mean residual litter was 40.2% of the initial value and annual decomposition rate constant (k) was 0.98 (0.49-1.80). Highest (p < 0.01) litter loss was in the first four months, when faunal abundance, SR, DHA and humidity were highest but it decreased with time. These variables and k were highest under the tree canopies. The litter loss and k were highest (p < 0.01) in TLS under the tree canopy, but the reverse trend was found for litter outside the canopy. Faunal abundance, litter loss, k, nutrient release and biochemical activities were highest (p < 0.01) in the 3-7 cm soil layer. Positive correlations of litter loss and soil fauna abundance with soil nutrients, SR and DHA demonstrated the interactions of litter quality and micro-habitats together with soil fauna on increased soil fertility. These results suggest that a Colophospermum mopane and L. sindicus silvopasture system best promotes faunal abundance, litter decomposition and soil fertility. The properties of these species and the associated faunal resources may be utilised as an ecosystem-restoration strategy in designing a silvopasture system. This may help to control land degradation and increase productivity sustainably in this environment.
Tripathi, G.; Deora, R.; Singh, G.
Environmental perturbations influence telomere dynamics in long-lived birds in their natural habitat.
Telomeres are regarded as markers of biological or cellular ageing because they shorten with the degree of stress exposure. Accordingly, telomere lengths should show different rates of change when animals are faced with different intensities of environmental challenges. However, a relationship between telomere length and the environment has not yet been tested within a natural setting. Here, we report longitudinal telomere dynamics in free-living, black-tailed gulls (Larus crassirostris) through the recapture of birds of a known age over 2-5 consecutive years. The rate of change in telomere lengths differed with respect to year but not sex or age. The years when gulls showed stable telomere lengths or increases in telomere lengths (from 2009 to 2010) and decreases in telomere lengths (from 2010 to 2011) were characterized by El Niþo and the Great Japan Earthquake, respectively. Both events are suspected to have had long-lasting effects on food availability and/or weather conditions. Thus, our findings that telomere dynamics in long-lived birds are influenced by dramatic changes in environmental conditions highlight the importance of environmental fluctuations in affecting stress and lifespan. PMID:23945210
Mizutani, Yuichi; Tomita, Naoki; Niizuma, Yasuaki; Yoda, Ken
Variables influencing the presence of subyearling fall Chinook salmon in shoreline habitats of the Hanford Reach, Columbia River
Little information currently exists on habitat use by subyearling fall Chinook salmon Oncorhynchus tshawytscha rearing in large, main-stem habitats. We collected habitat use information on subyearlings in the Hanford Reach of the Columbia River during May 1994 and April-May 1995 using point abundance electrofishing. We analyzed measures of physical habitat using logistic regression to predict fish presence and absence in shoreline habitats. The difference between water temperature at the point of sampling and in the main river channel was the most important variable for predicting the presence and absence of subyearlings. Mean water velocities of 45 cm/s or less and habitats with low lateral bank slopes were also associated with a greater likelihood of subyearling presence. Intermediate-sized gravel and cobble substrates were significant predictors of fish presence, but small (256-mm) substrates were not. Our rearing model was accurate at predicting fish presence and absence using jackknifing (80% correct) and classification of observations from an independent data set (76% correct). The habitat requirements of fall Chinook salmon in the Hanford Reach are similar to those reported for juvenile Chinook salmon in smaller systems but are met in functionally different ways in a large river.
Tiffan, K. F.; Clark, L. O.; Garland, R. D.; Rondorf, D. W.
Prestraining and Its Influence on Subsequent Fatigue Life.
National Technical Information Service (NTIS)
An experimental program was conducted to study the damaging effects of tensile and compressive prestrains on the fatigue life of nickel-base, Inconel 718 superalloy at room temperature. To establish baseline fatigue behavior, virgin specimens with a solid...
G. R. Halford M. A. Mcgaw Kalluri
Habitat Suitability Index Models: Slough Darter.
National Technical Information Service (NTIS)
A literature review encompassing habitat and species characteristics of the slough darter (Etheostoma gracile) is followed by a discussion of the relationship of habitat variables and life requisites of this species. These data are then incorporated into ...
E. A. Edwards M. Bacteller O. E. Maughan
Habitat Suitability Index Models: Common Carp
This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Common carp (Cyprinus carpio) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.
Edwards, Elizabeth A.; Twomey, Katie
Habitat Suitability Index Models: Black Bullhead
This is one of a series of publications that provide information on the habitat requirements of selected fish and wildlife species. Literature describing the relationship between habitat variables related to life requisites and habitat suitability for the Black bullhead (Ictalurus melas) are synthesized. These data are subsequently used to develop Habitat Suitability (HIS) models. The HSI models are designed to provide information that can be used in impact assessment and habitat management.
Stuber, Robert J.
Niche Habitats for Extra-Terrestrial Life: The Potential for Astrobiology on the Moons of Saturn and Jupiter
NASA Astrophysics Data System (ADS)
Astrobiology today has a strong anticipatory focus, and efforts are concentrated on determining the factors behind the potential presence, type, and distribution of life in our solar system and beyond. The critical requirements for life: a liquid solvent, and electron acceptors and donors for metabolism, guide the search, and is a central concept to the location and extent of circumstellar habitable zones. For our own solar system, however, the search can be widened beyond this narrow band of 'earth-like' conditions, and our increasing knowledge of the capabilities of life, as well as higher resolution imaging and analysis of solar system bodies, warrants the application of a more expansive habitable niche approach. The Saturnian and Jovian satellite systems are ideal for the application of this concept, and are here used to demonstrate how a collection of system characteristics may be used to assess the potential for individual bodies to harbour life. Europa, Callisto, and Ganymede in the Jovian system, and Enceladus, Titan, Hyperion, Iapetus, and Hyperion in the Saturnian system all possess characters that could make them conducive to the origin or maintenance of life upon or within them. The possibility of some of these bodies containing extraterrestrial life is reflected in future explorative missions.
Battison, Leila
Can environmental conditions experienced in early life influence future generations?
The consequences of early developmental conditions for performance in later life are now subjected to convergent interest from many different biological sub-disciplines. However, striking data, largely from the biomedical literature, show that environmental effects experienced even before conception can be transmissible to subsequent generations. Here, we review the growing evidence from natural systems for these cross-generational effects of early life conditions, showing that they can be generated by diverse environmental stressors, affect offspring in many ways and can be transmitted directly or indirectly by both parental lines for several generations. In doing so, we emphasize why early life might be so sensitive to the transmission of environmentally induced effects across generations. We also summarize recent theoretical advancements within the field of developmental plasticity, and discuss how parents might assemble different 'internal' and 'external' cues, even from the earliest stages of life, to instruct their investment decisions in offspring. In doing so, we provide a preliminary framework within the context of adaptive plasticity for understanding inter-generational phenomena that arise from early life conditions. PMID:24807254
Burton, Tim; Metcalfe, Neil B
Can environmental conditions experienced in early life influence future generations?
The consequences of early developmental conditions for performance in later life are now subjected to convergent interest from many different biological sub-disciplines. However, striking data, largely from the biomedical literature, show that environmental effects experienced even before conception can be transmissible to subsequent generations. Here, we review the growing evidence from natural systems for these cross-generational effects of early life conditions, showing that they can be generated by diverse environmental stressors, affect offspring in many ways and can be transmitted directly or indirectly by both parental lines for several generations. In doing so, we emphasize why early life might be so sensitive to the transmission of environmentally induced effects across generations. We also summarize recent theoretical advancements within the field of developmental plasticity, and discuss how parents might assemble different internal and external cues, even from the earliest stages of life, to instruct their investment decisions in offspring. In doing so, we provide a preliminary framework within the context of adaptive plasticity for understanding inter-generational phenomena that arise from early life conditions.
Burton, Tim; Metcalfe, Neil B.
EPA's Western Ecology Division is undertaking research addressing catchment-scale dynamics of freshwater habitat productivity for native fishes. Through partnerships with state and federal agencies and private landowners, current field efforts focus on linkages among stream chemi...
Patch size and shape influence the accuracy of mapping small habitat patches with a global positioning system.
Global positioning systems (GPS) are increasingly being used for habitat mapping because they provide spatially referenced data that can be used to characterize habitat structure across the landscape and document habitat change over time. We evaluated the accuracy of using a GPS for determining the size and location of habitat patches in a riverine environment. We simulated error attributable to a mapping-grade GPS receiver capable of achieving sub-meter accuracy onto discrete macrophyte bed and wood habitat patches (2 to 177 m(2)) that were digitized from an aerial photograph of the Laramie River, Wyoming, USA in a way that emulated field mapping. Patches with simulated error were compared to the original digitized patches. The accuracy in measuring habitat patches was affected most by patch size and less by patch shape and complexity. Perimeter length was consistently overestimated but was less biased for large, elongate patches with complex shapes. Patch area was slightly overestimated for small patches but was unbiased for large patches. Precision of area estimates was highest for large (>100 m(2)), elongate patches. Percent spatial overlap, a measure of the spatial accuracy of patch location, was low and variable for the smallest patches (2 to 5 m(2)). Mean percent spatial overlap was not related to patch shape but the precision of overlap was lower for small, elongate, and complex patches. Mapping habitat patches with a mapping-grade GPS can yield useful data, but research objectives will determine the acceptable amount of error and the smallest habitats that can be reliably measured. PMID:20890656
Dauwalter, Daniel C; Rahel, Frank J
Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.
This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration scenarios on habitat opportunity and the estuary's productive capacity for juvenile salmon. The underlying modeling system is part of the SATURN1coastal-margin observatory [1]. SATURN relies on 3D numerical models [2, 3] to systematically simulate and understand baroclinic circulation in the Columbia River estuary-plume-shelf system [4-7] (Fig. 1). Multi-year simulation databases of circulation are produced as an integral part of SATURN, and have multiple applications in understanding estuary/plume variability, the role of the estuary and plume on salmon survival, and functional changes in the estuary-plume system in response to climate and human activities.
Baptista, Antµnio M. [Oregon Health & Science University, Science and Technology Center for Coastal Margin Observation and Prediction
The influence of geomorphology and sedimentary processes on shallow-water benthic habitat distribution: Esperance Bay, Western Australia
NASA Astrophysics Data System (ADS)
The mapping of seabed environments is fundamental to successful fisheries management and environmental monitoring, however, there is an emerging need to better characterise habitats based upon appropriate physical parameters. In this study, relationships between seabed geomorphology and the distribution of benthic habitats were examined using multibeam sonar, underwater video, predicted wave energy, and sediment data for Esperance Bay, part of the Recherche Archipelago. This shallow (<50 m), high energy, biogenic sediment dominated environment is located in temperate southwestern Australia. Exposure to wave energy appears to determine the distribution of unconsolidated substrate, and is the most useful regional scale predictor of rhodolith and seagrass habitats. Although they are intermittently smothered by mobile sediments, limestone reefs provide habitat for a wide range of sessile organisms, even in very high wave exposure environments. The distribution of rhodolith beds is related to poorly sorted sediments that contain high gravel, mud, and CaCO 3 percentages. Our results reveal that in the Recherche Archipelago, wave abrasion coupled with localised sediment transport and accumulation play a major role in increasing the diversity of inner shelf benthic habitats. This highlights the value of assessing geomorphic processes in order to better understand the distribution and structure of benthic habitats.
Ryan, David A.; Brooke, Brendan P.; Collins, Lindsay B.; Kendrick, Gary A.; Baxter, Katrina J.; Bickers, Andy N.; Siwabessy, Paulus J. W.; Pattiaratchi, Charitha B.
The influence of life form on carbon and nitrogen relationships in tropical rainforest ferns.
Tropical ferns are characterized by a high diversity of plant life forms, yet there have been few large-scale studies on the functional ecology of these different forms. We examined epiphytic, hemiepiphytic, and terrestrial ferns, and asked whether there are differences in the mineral nutrition and water relations across different growth forms of a diverse assemblage of species. We measured specific leaf area, leaf nitrogen concentrations, and natural abundance of the stable isotopes delta(15)N and delta(13)C of 48 fern species from 36 genera across a wide range of habitats at La Selva Biological Station in Costa Rica. We found that epiphytes were significantly different in all measured variables from hemiepiphytic and terrestrial species, and that terrestrial and soil-rooted hemiepiphytes were indistinguishable in all variables excluding SLW. A multivariate analysis revealed that aspects of N nutrition were the most reliable at separating epiphytic species from other life forms. Our study demonstrates that the natural abundance of both C and N as well as N relations and leaf morphology are useful when segregating different plant life forms, and that the N cycle of epiphytic and terrestrial habitats function independently from each other. PMID:17415590
Watkins, James E; Rundel, Philip W; Cardelºs, Catherine L
Influence of cutting material and coating on tool quality and tool life
A review of some recently used cutting materials and coatings is presented. Theoretical models and real presentations of tool wear are shown, with the emphasis on diffusion wear. Tool life is shown for several combinations of cutting material\\/workpiece material depending on certain technological parameters. The main influences on tool life in relation to cutting speed (vc) and feed rate (f)
J. Kopa?
Art Influencing Art: The Making of "An Extraordinary Life."
ERIC Educational Resources Information Center
Explores the creation of "An Extraordinary Life: The Story of a Monarch Butterfly." Selects this book because of the unprecedented decision to give the 1998 Orbis Pictus Award to both the author and the illustrator for a work in which text and illustration melded together. Develops an event model, revealing the creation of this illustrated
Kerper, Richard M.
Prestraining and its influence on subsequent fatigue life
NASA Technical Reports Server (NTRS)
An experimental program was conducted to study the damaging effects of tensile and compressive prestrains on the fatigue life of nickel-base, Inconel 718 superalloy at room temperature. To establish baseline fatigue behavior, virgin specimens with a solid uniform gage section were fatigued to failure under fully-reversed strain-control. Additional specimens were prestrained to 2 percent, 5 percent, and 10 percent (engineering strains) in the tensile direction and to 2 percent (engineering strain) in the compressive direction under stroke-control, and were subsequently fatigued to failure under fully-reversed strain-control. Experimental results are compared with estimates of remaining fatigue lives (after prestraining) using three life prediction approaches: (1) the Linear Damage Rule; (2) the Linear Strain and Life Fraction Rule; and (3) the nonlinear Damage Curve Approach. The Smith-Watson-Topper parameter was used to estimate fatigue lives in the presence of mean stresses. Among the cumulative damage rules investigated, best remaining fatigue life predictions were obtained with the nonlinear Damage Curve Approach.
Halford, Gary R.; Mcgaw, Michael A.; Kalluri, Sreeramesh
Prestraining and its influence on subsequent fatigue life
An experimental program was conducted to study the damaging effects of tensile and compressive prestrains on the fatigue life of nickel-base, Inconel 718 superalloy at room temperature. To establish baseline fatigue behavior, virgin specimens with a solid uniform gage section were fatigued to failure under fully-reversed strain-control. Additional specimens were prestrained to 2 percent, 5 percent, and 10 percent (engineering strains) in the tensile direction and to 2 percent (engineering strain) in the compressive direction under stroke-control, and were subsequently fatigued to failure under fully-reversed strain-control. Experimental results are compared with estimates of remaining fatigue lives (after prestraining) using three life prediction approaches: (1) the Linear Damage Rule; (2) the Linear Strain and Life Fraction Rule; and (3) the nonlinear Damage Curve Approach. The Smith-Watson-Topper parameter was used to estimate fatigue lives in the presence of mean stresses. Among the cumulative damage rules investigated, best remaining fatigue life predictions were obtained with the nonlinear Damage Curve Approach.
Halford, G.R.; Mcgaw, M.A.; Kalluri, S.
Spatial scale-dependent habitat heterogeneity influences submarine canyon macrofaunal abundance and diversity off the Main and Northwest Hawaiian Islands
NASA Astrophysics Data System (ADS)
The mapping of biodiversity on continental margins on landscape scales is highly relevant to marine spatial planning and conservation. Submarine canyons are widespread topographic features on continental and island margins that enhance benthic biomass across a range of oceanic provinces and productivity regimes. However, it remains unclear whether canyons enhance faunal biodiversity on landscape scales relevant to marine protected area (MPA) design. Furthermore, it is not known which physical attributes and heterogeneity metrics can provide good surrogates for large-scale mapping of canyon benthic biodiversity. To test mechanistic hypotheses evaluating the role of different canyon-landscape attributes in enhancing benthic biodiversity at different spatial scales we conducted 34 submersible dives in six submarine canyons and nearby slopes in the Hawaiian archipelago, sampling infaunal macrobenthos in a depth-stratified sampling design. We employed multivariate multiple regression models to evaluate sediment and topographic heterogeneity, canyon transverse profiles, and overall water mass variability as potential drivers of macrobenthic community structure and species richness. We find that variables related to habitat heterogeneity at medium (0.13 km2) and large (15-33 km2) spatial scales such as slope, backscatter reflectivity and canyon transverse profiles are often good predictors of macrobenthic biodiversity, explaining 16-30% of the variance. Particulate organic carbon (POC) flux and distance from shore are also important variables, implicating food supply as a major predictor of canyon biodiversity. Canyons off the high Main Hawaiian Islands (Oahu and Moloka'i) are significantly affected by organic enrichment, showing enhanced infaunal macrobenthos abundance, whereas this effect is imperceptible around the low Northwest Hawaiian Islands (Nihoa and Maro Reef). Variable canyon alpha-diversity and high rates of species turnover (beta-diversity), particularly for polychaetes, suggest that canyons play important roles in maintaining high levels of regional biodiversity in the extremely oligotrophic system of the North Pacific Subtropical Gyre. This information is of key importance to the process of MPA design, suggesting that canyon habitats be explicitly included in marine spatial planning. The low-islands of Nihoa and Maro Reef in the NWHI showed a lack of sustained input of terrestrial and macrolagae detritus, likely having an influence on the observed low macrofaunal abundances (see further discussion of canyon effects in Section 4.3), and showing the fundamental role of coastal landscape characteristics in determining the amount and nature of allochthonous organic matter entering the system. Total and highly-mobile invertebrate megafauna abundances were two to three times higher in the submarine canyons and slopes of the MHI contrasted with the NWHI (Vetter et al., 2010), also demonstrating the role of this larger contribution of terrestrial and coastal organic enrichment in the MHI contrasted with the NWHI.
De Leo, Fabio C.; Vetter, Eric W.; Smith, Craig R.; Rowden, Ashley A.; McGranaghan, Matthew
Construction-Equipment Policy: Influence of Income Tax Law on Economic Life.
National Technical Information Service (NTIS)
The purpose of this study was to examine the influence of the income tax laws on the mathematical model. The two principal influences of the tax laws on the economic life of construction equipment are (1) the prohibition against using double declining bal...
J. Douglas
The Influence of the Mass Media on the Life Plans of Rural Students
ERIC Educational Resources Information Center
Rural students, who live in the villages of Russia, are more resolved than ever to leave their native land. Their decision is influenced by the mass media, which plays a large role in determining their views and the way they relate to the world. In this article, the author examines the influence of the mass media on the life of rural students
Sillaste, G. G.
Influence of host habitat on the occurrence of gill monogeneans Pseudodactylogyrus spp. on wild Japanese eels Anguilla japonica.
With technological improvements in otolith microchemical analysis, the flexible use of habitat from coastal marine to fresh waters has been discovered in Japanese eels Anguilla japonica. We examined the occurrence of 3 congeneric gill monogeneans-Pseudodactylogyrus anguillae, P. bini, and P. kamegaii-on wild Japanese eels, in relation to the host's flexibility. From April 2008 to October 2009, 114 eels were collected from a brackish-water cove and 2 rivers flowing into the cove in Ehime Prefecture, western Japan. Based on otolith microchemical analysis, the eels were discriminated according to the following 4 types of habitat use: freshwater residents (Type I), individuals utilizing low-salinity habitats (Type II), downstream habitat-shifters (Type III), and cove residents (Type IV). P. anguillae occurred mainly on Type I and II eels, while P. bini was primarily found on Type I eels. In contrast, P. kamegaii occurred mainly on Type III and IV eels. Thus, we conclude that species composition and infection levels of Pseudodactylogyrus spp. clearly differed with habitat-use patterns of Japanese eels. Also, since P. anguillae was scarcely found on either Type III or IV eels, this study suggests that previous identifications of monogeneans collected from European brackish-water localities as P. anguillae may require verification. PMID:22885512
Katahira, Hirotaka; Mizuno, Kouki; Umino, Tetsuya; Nagasawa, Kazuya
Modelling environmental influences on squid life history, distribution, and abundance
Following Caddy and Gulland's (1983) classification, squid populations can be described as displaying irregular or spasmodic abundance fluctuations, as opposed to steady or cyclical patterns. Squid are short-lived, fast growing marine animals, thought to be especially sensitive to environmental influences (Coelho, 1985). Because generations are essentially non-overlapping, modelling of population dynamics reduces to predicting recruitment success (Caddy, 1983; Pierce and
Graham J. Pierce; M. Begoþa Santos; Colin D. MacLeod; Jianjun Wang; Vasilis Valavanis; Alain F. Zuur
Habitat Management for Birds of Alabama.
National Technical Information Service (NTIS)
This report is a synthesis of existing literature and survey data for Alabama birds. The objectives of this report are to summarize available bird population data for major habitat types in Alabama, to indicate how changes in habitat influence population ...
S. H. Anderson C. S. Robbins J. R. Partelow
NSDL National Science Digital Library
If you could live anywhere in the world, where would you live? Do you think you could survive anywhere in the world or in any habitat? What types of adaptations might help you survive in your dream habitat? Many places seem great to visit, but you won't know if it's the place for you unless you know the characteristics of the habitat. This lesson will encourage your students to research habitats and adaptations that allow plants and animals to survive in their natural environments.
Brewster, Vanessa
The influence of life on the evolution of the atmosphere.
The early history of life on earth may have been characterized by coevolution of microbial metabolism and atmospheric composition. Metabolic developments affected the composition of the atmosphere, and the resulting changes in the atmosphere stimulated the evolution of new metabolic capabilities. The first organisms eked out an existence by deriving energy from the fermentation of organic compounds abiotically synthesized. The abiotic source was meager, however, and when autotrophy arose, life was freed from its dependence on abiotic synthesis. The expanded level of biological activity made possible by autotrophy resulted in an increased rate of burial of reduced organic matter in sea floor sediments. The resultant drain on the concentration of electron donors in the biosphere caused a decline in the hydrogen content of the atmosphere. Biological productivity was limited by the supply of reduced compounds. This paper explores the biogeochemical circulation of electron donors in the primitive anaerobic ocean, concluding that their shortage was so critical as to provide strong selective pressure for the evolution of algal photosynthesis. PMID:11968213
Walker, J C
Models of habitat associations for species often are developed with an im- plicit assumption that habitats are static, even though recent disturbance may have altered the landscape. We tested our hypothesis that trajectory and magnitude of habitat change influenced observed distribution and abundance of passerine birds breeding in shrubsteppe habitats of southwestern Idaho. Birds in this region live in dynamic
The influence of habitat, prey abundance, sex, and breeding success on the ranging behavior of Prairie Falcons
We studied the ranging behavior and habitat selection of radio-tagged Prairie Falcons (Falco mexicanus) during the breeding season in southwestern Idaho. The distribution and numbers of Townsend's ground squirrels (Spermophilus townsendii), the primary prey of Prairie Falcons in our study area, varied in response to drought during the study period. Prairie Falcons ranged over large areas (ca. 300 km2) and increased their foraging ranges in response to declining ground squirrels. Reptiles and birds were preyed upon most frequently when squirrels were rare. Males and females differed little in their use of space. Successful pairs ranged over smaller areas than non-nesters and unsuccessful pairs. Falcons nesting near habitat most suitable for ground squirrels ranged over smaller areas than those nesting farther from such habitat. Home ranges contained significantly more winterfat (Ceratoides lanata) and native perennial grasses (especially Poa secunda), and significantly less salt desert shrubs and exotic annual grasses than expected based on availability. Salt desert shrubs were found less than expected, based on availability in core areas within home ranges. Selection for winterfat and bluegrass in core areas was contingent upon selection at the larger scale of the home range; falcons with home ranges containing more winterfat and bluegrass than expected based on availability were less selective in their placement of core areas with respect to these habitats. We believe salient features of Prairie Falcon home ranges result largely from patchy distribution of landscape features associated with different densities and availabilities of Townsend's ground squirrels.
Marzluff, J. M.; Kimsey, Bryan A.; Schueck, Linda S.; McFadzen, Mary E.; Vekasy, M. S.; Bednarz, James C.
A study of air pollutants influencing life expectancy and longevity from spatial perspective in China.
Life expectancy and longevity are influenced by air pollutants and socioeconomic status, but the extend and significance are still unclear. Better understanding how the spatial differences of life expectancy and longevity are affected by air pollutants is needed for generating public health and environmental strategies since the whole of China is now threatened by deteriorated air quality. 85 major city regions were chosen as research areas. Geographically Weighted Regression (GWR) and Stepwise Regression (SR) were used to find the spatial correlations between health indicators and air pollutants, adjusted by per capita GDP(1). The results were, regions with higher life expectancy were mainly located in the east area and areas with good air quality, a regional difference of 10?g/m(3) in ambient air SO2(2) could cause adjusted 0.28year's difference in life expectancy, a regional difference of 10?g/m(3) in ambient air PM10(3) could lead to a longevity ratio difference of 2.23, and per capita GDP was positively associating with life expectancy but not longevity ratio, with a regional difference of 10,000RMB(4) associating with adjusted 0.49year's difference in life expectancy. This research also showed the evidences that there exist spatially differences for ambient air PM10 and SO2 influencing life expectancy and longevity in China, and this influences were clearer in south China. PMID:24768912
Wang, Li; BingganWei; Li, Yonghua; Li, Hairong; Zhang, Fengying; Rosenberg, Mark; Yang, Linsheng; Huang, Jixia; Krafft, Thomas; Wang, Wuyi
Neighborhood Influences on Late Life Cognition in the ACTIVE Study
Low neighborhood-level socioeconomic status has been associated with poorer health, reduced physical activity, increased psychological stress, and less neighborhood-based social support. These outcomes are correlates of late life cognition, but few studies have specifically investigated the neighborhood as a unique source of explanatory variance in cognitive aging. This study supplemented baseline cognitive data from the ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly) study with neighborhood-level data to investigate (1) whether neighborhood socioeconomic position (SEP) predicts cognitive level, and if so, whether it differentially predicts performance in general and specific domains of cognition and (2) whether neighborhood SEP predicts differences in response to short-term cognitive intervention for memory, reasoning, or processing speed. Neighborhood SEP positively predicted vocabulary, but did not predict other general or specific measures of cognitive level, and did not predict individual differences in response to cognitive intervention.
Sisco, Shannon M.; Marsiske, Michael
Collective Emotions Online and Their Influence on Community Life
Background E-communities, social groups interacting online, have recently become an object of interdisciplinary research. As with face-to-face meetings, Internet exchanges may not only include factual information but also emotional information how participants feel about the subject discussed or other group members. Emotions in turn are known to be important in affecting interaction partners in offline communication in many ways. Could emotions in Internet exchanges affect others and systematically influence quantitative and qualitative aspects of the trajectory of e-communities? The development of automatic sentiment analysis has made large scale emotion detection and analysis possible using text messages collected from the web. However, it is not clear if emotions in e-communities primarily derive from individual group members' personalities or if they result from intra-group interactions, and whether they influence group activities. Methodology/Principal Findings Here, for the first time, we show the collective character of affective phenomena on a large scale as observed in four million posts downloaded from Blogs, Digg and BBC forums. To test whether the emotions of a community member may influence the emotions of others, posts were grouped into clusters of messages with similar emotional valences. The frequency of long clusters was much higher than it would be if emotions occurred at random. Distributions for cluster lengths can be explained by preferential processes because conditional probabilities for consecutive messages grow as a power law with cluster length. For BBC forum threads, average discussion lengths were higher for larger values of absolute average emotional valence in the first ten comments and the average amount of emotion in messages fell during discussions. Conclusions/Significance Overall, our results prove that collective emotional states can be created and modulated via Internet communication and that emotional expressiveness is the fuel that sustains some e-communities.
Chmiel, Anna; Sienkiewicz, Julian; Thelwall, Mike; Paltoglou, Georgios; Buckley, Kevan; Kappas, Arvid; Holyst, Janusz A.
Influence of the Inclusion Shape on the Rolling Contact Fatigue Life of Carburized Steels
NASA Astrophysics Data System (ADS)
It has been well known that the flaking failure in rolling contact fatigue (RCF) originates from nonmetallic inclusions in steels, and their apparent size is one of the important factors affecting RCF life. However, the influence of inclusion shape on the RCF life has not been fully clarified. In this study, attention was paid to the influence of the inclusion shape on the RCF life. This was evaluated by using carburized JIS-SCM420 (SAE4320) steels that contained two different shapes of MnSstringer type and spheroidized typeas inclusions. Sectional observations were made to investigate the relation between the occurrence of shear crack in the subsurface and the shape of MnS. It was found that the RCF life was well correlated with the length of MnS projected to the load axis, and the initiation of shear crack in subsurface was accelerated as the length of MnS increased.
Neishi, Yutaka; Makino, Taizo; Matsui, Naoki; Matsumoto, Hitoshi; Higashida, Masashi; Ambai, Hidetaka
Heterozygote excess through life history stages in Cestrum miradorense Francey (Solanaceae), an endemic shrub in a fragmented cloud forest habitat.
Comparisons of genetic diversity and population genetic structure among different life history stages provide important information on the effect of the different forces and micro-evolutionary processes that mould diversity and genetic structure after fragmentation. Here we assessed genetic diversity and population genetic structure using 32 allozymic loci in adults, seeds, seedlings and juveniles of eight populations of the micro-endemic shrub Cestrum miradorense in a highly fragmented cloud forest in central-eastern Mexico. We expected that due to its long history or rarity, this species may have endured the negative effects of fragmentation and would show moderate to high levels of genetic diversity. High genetic diversity (H(e) = 0.445 Ý 0.03), heterozygote excess (F(IT) = -0.478 Ý 0.034, F(IS) = -0.578 Ý 0.023) and low population differentiation (F(ST) = 0.064 Ý 0.011) were found. Seeds had higher genetic diversity (H(e) = 0.467 Ý 0.05) than the later stages (overall mean for adults, seedlings and juveniles H(e) = 0.438 Ý 0.08). High gene flow was observed despite the fact that the fragmentation process began more than 100 years ago. We conclude that the high genetic diversity was the result of natural selection, which favours heterozygote excess in all stages, coupled with a combination of a reproductive system and seed/pollen dispersal mechanisms that favour gene flow. PMID:22672140
Reyes-Zepeda, F; GonzÃlez-Astorga, J; Montaþa, C
Influence of habitat heterogeneity on distribution, occupancy patterns, and productivity of breeding peregrine falcons in central West Greenland
We used occupancy and productivity data collected at 67 cliffs used for nesting from 1972 to 1999 to assess patterns of distribution and nest-site selection in an increasing population of Peregrine Falcons (Falco peregrinus) in central West Greenland. Peregrine Falcons breeding at traditionally occupied cliffs used for nesting had significantly lower variation in productivity and thus these cliffs were better quality sites. This indicates that Peregrine Falcons occupied cliffs according to a pattern of despotic distribution. Falcons breeding at cliffs that were consistently occupied during the breeding season had higher average productivity and lower variation in productivity than falcons at inconsistently occupied cliffs, and thus consistent occupancy also was indicative of cliff quality. Features of high quality habitat included tall cliffs, greater change in elevation from the lowest point within 3 km of the cliff to the cliff top (elevation gain), and protection from weather on the eyrie ledge. Spacing of suitable and occupied cliffs also was an important feature, and the best cliffs generally were more isolated. Increased spacing was likely a mechanism for reducing intraspecific competition. Our results suggest that Peregrine Falcons use a resource defense strategy to compete for better quality habitats and may use spacing and physical features of a nest site to identify good quality breeding habitat. ?? The Cooper Ornithological Society 2006.
Wightman, C. S.; Fuller, M. R.
Influence of habitat heterogeneity on distribution, occupancy patterns, and productivity of breeding peregrine falcons in central west Greenland
We used occupancy and productivity data collected at 67 cliffs used for nesting from 1972 to 1999 to assess patterns of distribution and nest-site selection in an increasing population of Peregrine Falcons (Falco peregrinus) in central West Greenland. Peregrine Falcons breeding at traditionally occupied cliffs used for nesting had significantly lower variation in productivity and thus these cliffs were better quality sites. This indicates that Peregrine Falcons occupied cliffs according to a pattern of despotic distribution. Falcons breeding at cliffs that were consistently occupied during the breeding season had higher average productivity and lower variation in productivity than falcons at inconsistently occupied cliffs, and thus consistent occupancy also was indicative of cliff quality. Features of high quality habitat included tall cliffs, greater change in elevation from the lowest point within 3 km of the cliff to the cliff top (elevation gain), and protection from weather on the eyrie ledge. Spacing of suitable and occupied cliffs also was an important feature, and the best cliffs generally were more isolated. Increased spacing was likely a mechanism for reducing intraspecific competition. Our results suggest that Peregrine Falcons use a resource defense strategy to compete for better quality habitats and may use spacing and physical features of a nest site to identify good quality breeding habitat.
Wightman, C.; Fuller, Mark R.
Habitat Suitability Index Models: Black Crappie
Characteristics and habitat requirements of the black crappie (Pomoxis nigromaculatus) are described in a review of Habitat Suitability Index models. This is one in a series of publications to provide information on the habitat requirements of selected fish and wildlife species. Numerous literature sources have been consulted in an effort to consolidate scientific data on species-habitat relationships. These data have subsequently been synthesized into explicit Habitat Suitability Index (HSI) models. The models are based on suitability indices indicating habitat preferences. Indices have been formulated for variables found to affect the life cycle and survival of each species. Habitat Suitability Index (HSI) models are designed to provide information for use in impact assessment and habitat management activities. The HSI technique is a corollary to the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures.
Edwards, Elizabeth A.; Krieger, Douglas A.; Bacteller, Mary; Maughan, O. Eugene
Subsurface Microbial Habitats on Mars (Abstract Only).
National Technical Information Service (NTIS)
We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on...
P. J. Boston C. P. Mckay
Explaining variance of avian malaria infection in the wild: the importance of host density, habitat, individual life-history and oxidative stress
Background Avian malaria (Plasmodium sp.) is globally widespread, but considerable variation exists in infection (presence/absence) patterns at small spatial scales. This variation can be driven by variation in ecology, demography, and phenotypic characters, in particular those that influence the hosts resistance. Generation of reactive oxygen species (ROS) is one of the hosts initial immune responses to combat parasitic invasion. However, long-term ROS exposure can harm the host and the redox response therefore needs to be adjusted according to infection stage and host phenotype. Here we use experimental and correlational approaches to assess the relative importance of host density, habitat composition, individual level variation and redox physiology for Plasmodium infection in a wild population of great tits, Parus major. Results We found that 36% of the great tit population was infected with Plasmodium (22% P. relictum and 15% P. circumflexum prevalence) and that patterns of infection were Plasmodium species-specific. First, the infection of P. circumflexum was significantly higher in areas with experimental increased host density, whereas variation in P. relictum infection was mainly attributed to age, sex and reproduction. Second, great tit antioxidant responses total and oxidizied glutathione - showed age- , sex- and Plasmodium species-specific patterns between infected and uninfected individuals, but reactive oxygen metabolites (ROM) showed only a weak explanatory power for patterns of P. relictum infection. Instead ROM significantly increased with Plasmodium parasitaemia. Conclusions These results identify some key factors that influence Plasmodium infection in wild birds, and provide a potential explanation for the underlying physiological basis of recently documented negative effects of chronic avian malaria on survival and reproductive success.
NSDL National Science Digital Library
This activity is about the impact of climate change in aquatic ecosystems. Learners will build two aquatic habitats using soda bottles and other materials and simulate climate change conditions in one of the habitats. After making daily qualitative and quantitative observations over a four-week period, students will be able to describe the effects of climate change on aquatic ecosystems. This activity is part of the "Climate Change, Wildlife and Wildlands: A Toolkit for Formal and Informal Educators."
Factors Influencing Health-Related Quality of Life of Overweight and Obese Children in South Korea
ERIC Educational Resources Information Center
The purpose of this study was to identify factors influencing health-related quality of life (HRQoL) of overweight and obese children in Korea. This study employed a cross-sectional descriptive study design. A total of 132 overweight and obese children participated in the study. Anthropometric measurements included body mass index, percent body
Kim, Hee Soon; Park, Jiyoung; Ma, Yumi; Ham, Ok Kyung
The Influence of Western Society's Construction of a Healthy Daily Life on the Conceptualisation of Occupation
This article proposes that the current conceptualisation of occupation within the dominant Anglophone literature reflects central elements of Western society's construction of a healthy daily life, the ideal and expected way to live. Contemporary theories of social action are used to describe the structuring influence of social institutions on daily activity. Four of the commonly identified characteristics of occupation, that
Sarah Kantartzis; Matthew Molineux
The Influence of Life Roles and Readiness for Career Decision Making: The Case of Fabian.
ERIC Educational Resources Information Center
Discusses case study of Fabian, nontraditional college student who sought assistance at university counseling center in choosing a career path. Looks at influence of life roles, conceptualizes case using Super's Model of Readiness for Career Decision Making, identifies missing information, and suggests career counseling interventions. (NB)
Niles, Spencer G.
Factors Influencing Older Worker Quality of Life and Intent to Continue to Work
ERIC Educational Resources Information Center
High turnover has been a major problem in healthcare organizations. The purpose of this study was to examine the relationship among job characteristics, social support, and organizational characteristics on quality of the working life. Subsequently, the intent was to examine how those factors collectively influence turnover intention. A
Spokus, Diane
Ethnic differences in influences on quality of life at older ages: a quantitative analysis
This article sets out to examine ethnic differences in the key influences on quality of life for older people in the context of the increasing health and wealth of British older people generally and the ageing of the post-1945 migrants. It is based on secondary multivariate analysis of the Fourth National Survey of Ethnic Minorities of England and Wales. Respondents
The Life Skills Program IPSY: Positive Influences on School Bonding and Prevention of Substance Misuse
ERIC Educational Resources Information Center
The present study investigated whether a life skills program (LSP) for the prevention of adolescent substance misuse can have positive influences on a school context and on school bonding. The study also explored whether effects on alcohol use are mediated by positive effects on school bonding resulting from program participation. The LSP IPSY
Wenzel, Victoria; Weichold, Karina; Silbereisen, Rainer K.
Influence of Life Stress on Depression: Moderation by a Polymorphism in the 5-HTT Gene
In a prospective-longitudinal study of a representative birth cohort, we tested why stressful experiences lead to depression in some people but not in others. A functional polymorphism in the promoter region of the serotonin transporter (5-HTT) gene was found to moderate the influence of stressful life events on depression. Individuals with one or two copies of the short allele of
Avshalom Caspi; Karen Sugden; Terrie E. Moffitt; Alan Taylor; Ian W. Craig; HonaLee Harrington; Joseph McClay; Jonathan Mill; Judy Martin; Antony Braithwaite; Richie Poulton
The Influence of Social Relations on Mortality in Later Life: A Study on Elderly Danish Twins
ERIC Educational Resources Information Center
Purpose: We examined whether the presence of a spouse and the frequency of interaction with children, relatives, and friends significantly influence the risk of dying in late life. We assessed these effects separately by gender, controlling for self-reported health. In addition, we examined whether interaction with the co-twin has a different
Rasulo, Domenica; Christensen, Kaare; Tomassini, Cecilia
Does Thermal Variability Experienced at the Egg Stage Influence Life History Traits across Life Cycle Stages in a Small Invertebrate?
Although effects of thermal stability on eggs have often been considered in vertebrates, there is little data thermal stability in insect eggs even though these eggs are often exposed in nature to widely fluctuating ambient conditions. The modularity of development in invertebrates might lead to compensation across life cycle stages but this remains to be tested particularly within the context of realistic temperature fluctuations encountered in nature. We simulated natural temperate fluctuations on eggs of the worldwide cruciferous insect pest, the diamondback moth (DBM), Plutella xylostella (L.), while maintaining the same mean temperature (25¯CÝ0¯C, 25Ý4¯C, 25Ý6¯C, 25Ý8¯C, 25Ý10¯C, 25Ý12¯C) and assessed egg development, survival and life history traits across developmental stages. Moderate fluctuations (25Ý4¯C, 25Ý6¯C) did not influence performance compared to the constant temperature treatment, and none of the treatments influenced egg survival. However the wide fluctuating temperatures (25Ý10¯C, 25Ý12¯C) slowed development time and led to an increase in pre-pupal mass, although these changes did not translate into any effects on longevity or fecundity at the adult stage. These findings indicate that environmental effects can extend across developmental stages despite the modularity of moth development but also highlight that there are few fitness consequences of the most variable thermal conditions likely to be experienced by Plutella xylostella.
Xing, Kun; Hoffmann, Ary A.; Ma, Chun-Sen
Climate-based model predicting acarological risk of encountering the human-biting adult life stage of Dermacentor andersoni (Acari: Ixodidae) in a key habitat type in Colorado.
We exploited an elevation (climate) gradient ranging from 1,700 to 2,500 m in Poudre Canyon of Larimer County, CO, to determine climatic correlates of abundance per 15-s drag sampling time unit (hereafter referred to as abundance) of the human-biting adult life stage of the Rocky Mountain wood tick, Dermacentor andersoni Stiles (Acari: Ixodidae), in a key risk habitat for tick exposure: south/west-facing, rocky hillsides with mixed grass-brush-conifer vegetation. The relationship between elevation and abundance was parabolic, with peak tick abundances occurring at mid-range elevations (2,200-2,400 m) and tick abundances approaching zero at approximately 2,100 and 2,500 m. Regression modeling demonstrated that abundance of host-seeking adult ticks in south/west-facing exposures was accurately predicted by several climate variables related to temperature (e.g., mean annual minimum temperature, maximum temperature, and base 10 degrees C growing degree-days, and median length of annual freeze-free period; r2 values ranging from 0.771 to 0.864), whereas mean annual precipitation, snowfall, or relative humidity were uninformative in this respect (r2 values ranging from 0.020 to 0.316). Abundance of D. andersoni adults peaked at a mean annual maximum temperature of approximately 10 degrees C and a mean annual growing degree-day value of approximately 650. Relationships between climate variables and abundance of D. andersoni adults were used to create geographic information system (GIS)-based models for predicted tick abundance in south/west-facing exposures in Larimer County. This is the first GIS-based model developed for spatial patterns of abundance of D. andersoni. Finally, preliminary data from Poudre Canyon indicate a shift toward peak abundances of D. andersoni adults occurring in sheltered northern/eastern exposures, rather than in drier and hotter southern/ western exposures, at elevations below 2,100 m. PMID:17695027
Eisen, L; Meyer, A M; Eisen, R J
Habitat of In Vivo Transformation Influences the Levels of Free Radical Scavengers in Clinostomum complanatum: Implications for Free Radical Scavenger Based Vaccines against Trematode Infections
Background Since free radical scavengers of parasite origin like glutathione-S-transferase and superoxide dismutase are being explored as prospective vaccine targets, availability of these molecules within the parasite infecting different hosts as well as different sites of infection is of considerable importance. Using Clinostomum complanatum, as a model helminth parasite, we analysed the effects of habitat of in vivo transformation on free radical scavengers of this trematode parasite. Methods Using three different animal models for in vivo transformation and markedly different sites of infection, progenetic metacercaria of C. complanatum were transformed to adult ovigerous worms. Whole worm homogenates were used to estimate the levels of lipid peroxidation, a marker of oxidative stress and free radical scavengers. Results Site of in vivo transformation was found to drastically affect the levels of free radical scavengers in this model trematode parasite. It was observed that oxygen availability at the site of infection probably influences levels of free radical scavengers in trematode parasites. Conclusion This is the first report showing that habitat of in vivo transformation affects levels of free radical scavengers in trematode parasites. Since free radical scavengers are prospective vaccine targets and parasite infection at ectopic sites is common, we propose that infections at different sites, may respond differently to free radical scavenger based vaccines.
Ahmad, Irshad; Ahmad, Masood
NSDL National Science Digital Library
This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 6-8. It focuses on aquatic habitats and how community wastewater-disposal methods can harm these habitats. Students research the harmful effects of wastewater as well as environmental techniques, then invite a guest speaker to class to discuss this subject and answer their questions. Included are objectives, materials, procedures, discussion questions, evaluation ideas, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.
Influence of novel and conventional antipsychotic medication on subjective quality of life.
OBJECTIVE: To assess the impact of novel antipsychotic medication on the subjective quality of life of patients with schizophrenia and schizoaffective disorders. DESIGN: Retrospective, cross-sectional analysis of data from 2 studies conducted in 1997 and 1998. PATIENTS: 91 outpatients (50 men and 41 women, mean age 43.3 years) diagnosed with schizophrenia (n = 70) and schizoaffective disorder (n = 21); the mean Global Assessment of Functioning score for these patients was 48.0 (standard deviation 12.5). OUTCOME MEASURE: Patients were categorized into 1 of 3 groups: those taking conventional (n = 41), novel (n = 26) or mixed (both conventional and novel) (n = 24) antipsychotics. Responses on the Satisfaction with Life Domains Scale were used to assess subjective quality of life. RESULTS: The type of antipsychotic medication taken did not influence satisfaction with life scores; in fact, 2 items dealing with social relationships were scored lower by those taking novel antipsychotics. CONCLUSIONS: Patients taking novel antipsychotics may expect more from life, and this might explain their lower quality-of-life scores.
Tempier, R; Pawliuk, N
National Technical Information Service (NTIS)
Discusses the general characteristics of life as we know it. Uses a number of examples to show how life has adapted to earth conditions and certain life forms can withstand environmental shocks. Describes the conditions on Mars with the question raised as...
NSDL National Science Digital Library
In this outdoor activity, learners discover the wonders of the habitat surrounding them. After reading "The Empty Lot," a picture book by Dale Fife, learners observe and record in writing what happens in the natural environment around them. Spending time outdoors observing nature can help learners better understand and appreciate the world in which we live.
Aquariums, Association O.
Life-History Evolution on Tropidurinae Lizards: Influence of Lineage, Body Size and Climate
The study of life history variation is central to the evolutionary theory. In many ectothermic lineages, including lizards, life history traits are plastic and relate to several sources of variation including body size, which is both a factor and a life history trait likely to modulate reproductive parameters. Larger species within a lineage, for example tend to be more fecund and have larger clutch size, but clutch size may also be influenced by climate, independently of body size. Thus, the study of climatic effects on lizard fecundity is mandatory on the current scenario of global climatic change. We asked how body and clutch size have responded to climate through time in a group of tropical lizards, the Tropidurinae, and how these two variables relate to each other. We used both traditional and phylogenetic comparative methods. Body and clutch size are variable within Tropidurinae, and both traits are influenced by phylogenetic position. Across the lineage, species which evolved larger size produce more eggs and neither trait is influenced by temperature components. A climatic component of precipitation, however, relates to larger female body size, and therefore seems to exert an indirect relationship on clutch size. This effect of precipitation on body size is likely a correlate of primary production. A decrease in fecundity is expected for Tropidurinae species on continental landmasses, which are predicted to undergo a decrease in summer rainfall.
Brandt, Renata; Navas, Carlos A.
Habitat Suitability Index Models: Gulf of Mexico American Oyster.
National Technical Information Service (NTIS)
A review and synthesis of existing information on the characteristics, life requisites, and specific habitat requirements were used to develop an estuarine habitat model for Gulf of Mexico stocks of the American oyster (Crassostrea virginica). Eight habit...
E. W. Cake
Early life influences on the development of chronic obstructive pulmonary disease
There is increasing evidence that chronic obstructive pulmonary disease (COPD) is not simply a disease of old age that is largely restricted to heavy smokers, but may be associated with insults to the developing lung during foetal life and the first few years of postnatal life, when lung growth and development are rapid. A better understanding of the long-term effects of early life factors, such as intrauterine growth restriction, prenatal and postnatal exposure to tobacco smoke and other pollutants, preterm delivery and childhood respiratory illnesses, on the subsequent development of chronic respiratory disease is imperative if appropriate preventive and management strategies to reduce the burden of COPD are to be developed. The extent to which insults to the developing lung are associated with increased risk of COPD in later life depends on the underlying cause, timing and severity of such derangements. Suboptimal conditions in utero result in aberrations of lung development such that affected individuals are born with reduced lung function, which tends to remain diminished throughout life, thereby increasing the risk both of wheezing disorders during childhood and subsequent COPD in genetically susceptible individuals. If the current trend towards the ever-increasing incidence of COPD is to be reversed, it is essential to minimize risks to the developing lung by improvements in antenatal and neonatal care, and to reduce prenatal and postnatal exposures to environmental pollutants, including passive tobacco smoke. Furthermore, adult physicians need to recognize that lung disease is potentially associated with early life insults and provide better education regarding diet, exercise and avoidance of smoking to preserve precious reserves of lung function in susceptible adults. This review focuses on factors that adversely influence lung development in utero and during the first 5 years of life, thereby predisposing to subsequent COPD.
Sonnappa, Samatha
Relative influence of local- and landscape-level habitat quality on aquatic plant diversity in shallow open-water wetlands in Albertas boreal zone: direct and indirect effects
Reclamation usually involves modification of the local environment to achieve some biotic target, but if the influence of\\u000a Landscape Condition on that target is great, we may fail to meet it despite efforts at the local-level. We sought to determine\\u000a the relative influence of local- and landscape-level habitat on aquatic plant diversity in shallow open-water wetlands. Furthermore,\\u000a we asked whether
Rebecca C. RooneySuzanne; Suzanne E. Bayley
Influence of oceanic factors on Anguilla anguilla (L.) over the twentieth century in coastal habitats of the Skagerrak, southern Norway.
The European eel (Anguilla anguilla L.) is distributed in coastal and inland habitats all over Europe, but spawns in the Sargasso Sea and is thus affected by both continental and oceanic factors. Since the 1980s a steady decline has been observed in the recruitment of glass eels to freshwater and in total eel landings. The eel is considered as critically endangered on the International Union for the Conservation of Nature and Natural Resources Red List of species. The Skagerrak beach seine survey from Norway constitutes the longest fishery-independent dataset on yellow/silver eels (starting in 1904). The Skagerrak coastal region receives larvae born in the Sargasso Sea spawning areas that have followed the Gulf Stream/North Atlantic Drift before they penetrate far into the North Sea. The Skagerrak coastal time series is therefore particularly valuable for exploring the impacts of oceanic factors on fluctuations in eel recruitment abundance. Analyses showed that Sargasso Sea surface temperature was negatively correlated with eel abundance, with a lag of 12 years revealing a cyclic and detrimental effect of high temperatures on the newly hatched larvae. The North Atlantic Oscillation index and inflow of North Atlantic water into the North Sea were negatively correlated with eel abundance, with a lag of 11 years. Increased currents towards the North Atlantic during high North Atlantic Oscillation years may send larvae into the subpolar gyre before they are ready to metamorphose and settle, resulting in low recruitment in the northern part of the distribution area for these years. The Skagerrak time series was compared with glass eel recruitment to freshwater in the Netherlands (Den Oever glass eel time series), and similar patterns were found revealing a cycle linked to changes in oceanic factors affecting glass eel recruitment. The recent decline of eels in the Skagerrak also coincided with previously documented shifts in environmental conditions of the North Sea ecosystem. PMID:20798112
Durif, Caroline M F; Gj½saeter, Jakob; V½llestad, L Asbj½rn
Influence of the real-life structures in optical metrology using spectroscopic scatterometry analysis
NASA Astrophysics Data System (ADS)
During the last five years scatterometry measurement using ellispometry and reflectometry has met a great interest in nano and microelectronics fab. Today, this technology of measurement is used to control lot production and has become mature for 1D-grating measurements. Nevertheless, some aspects of this method of measurement are always under research studies. This paper focuses on one of these aspects: the evaluation of the influence of the "real-life 1D-structure" (linewidth variations along the lines and line to line, roughness, defect inside the grating) on spectroscopic signatures and on scatterometry measurement methods. The measurements have been carried out on KLA-TENCOR ellispometer and on Nanometrics reflectometer in order to compare the two methods of measurement. The simulations have been done with MMFE (Modal Method of Fourier Expansion) software developed by LETI labs. To control defect characteristics and defect distributions, one wafer was printed using electron beam lithography. The aim is the evaluation of the impact of defects in the grating on the spectroscopic signatures and its influence on extracted geometrical parameters by fitting the experimental curves. Different deviations to real-life structures have been studied. First we focus on the influence of typical defects of lithography processes such as bridging and partial destruction of lines and on the influence of CD distribution values inside the grating. Then, we study the influence and the possibilities of measuring Line Edge Roughness (LER). For LER measurements different targets have been also exposed on e-beam tool. Simulations and experimental measurements have been carried out. All the results obtained have been compared with imaging standard tool: top down SEM measurement.
Quintanilha, R.; Hazart, J.; Thony, P.; Henry, D.
Small-scale Heterogeneity in Soil Quality Influences Photosynthetic Efficiency and Habitat Selection in a Clonal Plant
? Background and Aims In clonal plants, internode connections allow translocation of photosynthates, water, nutrients and other substances among ramets. Clonal plants form large systems that are likely to experience small-scale spatial heterogeneity. Physiological and morphological responses of Fragaria vesca to small-scale heterogeneity in soil quality were investigated, together with how such heterogeneity influences the placement of ramets.As a resultof
Environmental Contingency in Life History Strategies: The Influence of Mortality and Socioeconomic Status on Reproductive Timing
Why do some people have children early, whereas others delay reproduction? By considering the trade-offs between using ones resources for reproduction versus other tasks, the evolutionary framework of life history theory predicts that reproductive timing should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced the desire to have children sooner rather than later. The effects of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals growing up relatively poor, mortality cues produced a desire to reproduce soonerto want children now, even at the cost of furthering ones education or career. Conversely, for individuals growing up relatively wealthy, mortality cues produced a desire to delay reproductionto further ones education or career before starting a family. Overall, mortality cues appear to shift individuals into different life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors can influence fertility and family size.
Griskevicius, Vladas; Delton, Andrew W.; Robertson, Theresa E.; Tybur, Joshua M.
Influence of Sleep Disturbances on Quality of Life of Iranian Menopausal Women
Background. Subjective sleep disturbances increase during menopause. Some problems commonly encountered during menopause, such as hot flushes and sweating at night, can cause women to have difficulty in sleeping. These complaints can influence quality of life of menopausal women. Methods. This cross-sectional study was performed on menopausal women attending health centers in Qazvin for periodic assessments. We measured excessive daytime sleepiness by Epworth sleepiness scale (ESS), obstructive sleep apnea (OSA) by the Berlin questionnaire, and insomnia by the insomnia severity index (ISI). We evaluate quality of life by the Menopause specific quality of life questionnaire (MENQOL). Results. A total of 380 menopausal women entered the study. Mean age of participated women was 57.6 Ý 6.02. Mean duration of menopause was 6.3 Ý 4.6. The frequency of severe and moderate insomnia was 8.4% (32) and 11.8% (45). Severe daytime sleepiness (ESS???10) was present in 27.9% (80) of the participants. Multivariate analytic results show that insomnia and daytime sleepiness have independent negative impact on each domain and total score of MENQOL questionnaire. Conclusion. According to our findings, EDS and insomnia are frequent in menopausal women. Both EDS and insomnia have significant quality of life impairment.
Yazdi, Zohreh; Sadeghniiat-Haghighi, Khosro; Ziaee, Amir; Elmizadeh, Khadijeh; Ziaeeha, Masomeh
The influence of early and recent life stress on severity of depression.
The influence of life stressors arising in different life stages on the severity of depression was examined in a sample of 123 depressive women, ranging from 22 to 64 years of age. In an interview, information was obtained on the incidence of certain life stressors in early and recent periods. The severity of depression was measured using the Beck Depression Inventory. The results indicate that experience of physical or sexual abuse before the age of 19 is strongly associated with severity of depression. Also, most women suffering from severe depression had previous and recent difficulties in their relationships with parents, partner or others and recent problems with self-esteem. A hypothetical model for predicting the severity of depression was evaluated. Difficulties experienced one year prior to assessment appeared to directly predict severity of depression. Difficulties with social relationships whose origin could be traced back to early periods and that had a continuing effect throughout life were found to be crucial factors for indirectly predicting the severity of depression. PMID:2343756
Garnefski, N; van Egmond, M; Straatman, A
[The influences of interaction during online gaming on sociability and aggression in real life].
This study examined the influences of online gaming on sociability and aggression in real life. It was hypothesized that the effects of online gaming would differ depending on the interaction style of the online-gamers. Online-gamers in Japan (n = 1 477) were asked to respond to questionnaires that measured interaction style during online gaming, the effects of sociability and aggression, as well as social and individual orientation in real life. Factor analysis of the scores for interaction style extracted five factors. Covariance structure analysis indicated that sociable interactions such as "Broadening relations" and "Feeling of belonging" promoted sociability in real life. In addition, "Release from daily hassles" promoted sociability and decreased aggression. In contrast, non-sociable and aggressive interactions decreased sociability and increased aggression. The results also suggested that a social orientation in real life promoted sociable interactions during game playing, while an individual orientation promoted non-sociable and aggressive interactions. These results supported the hypotheses and suggested that online gaming resulted in positive outcomes for those who are socially, but negative outcomes for those who are not. PMID:20235474
Fuji, Kei; Yoshida, Fujio
Do Maternal Quality of Life and Breastfeeding Difficulties Influence the Continuation of Exclusive Breastfeeding?
Objectives. This study was conducted to determine whether maternal quality of life (QOL) and breastfeeding difficulties influence the continuation of exclusive breastfeeding (EBF). Methods. In a survey, 358 consecutive pregnant women filled out a quality of life questionnaire in the third trimester of pregnancy and the breastfeeding experience scale at 4 weeks postpartum. We assessed breastfeeding practices every month up to 6 months postpartum. Results. Only 11.8% of women continued EBF at six months. Mothers who continued EBF at 2 and 4 months postpartum had better QOL in late pregnancy than mothers who discontinued it (P < 0.05). There were no significant differences between the two groups in QOL scores at 6 months postpartum. Mothers who continued EBF at 2 months postpartum experienced less breastfeeding difficultties during one month postpartum than mothers who discontinued it (P < 0.05). Conclusion. In attempts to promote EBF, mothers with poor QOL or breastfeeding difficulties in early postpartum should be identified and helped.
Mousavi, Seyed Abbas; Chaman, Reza; Khosravi, Ahmad
The Teacher I Wish to Be: Exploring the Influence of Life Histories on Student Teacher Idealised Identities
ERIC Educational Resources Information Center
This paper examines the influence of life histories and apprenticeship of observation on the formation of student teachers' idealised identities. The life histories of 15 student teachers are decoded. Through eliciting from the student teachers the teacher they wish to be, the paper focuses on the interplay between the personal histories and ideal
Furlong, Catherine
Factors influencing the quality of life in patients with HIV in Malaysia
Purpose The aim of this study was to determine the socio-demographic, clinical and psychological factors influencing the quality of\\u000a life (QOL) in patients with human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV\\/AIDS).\\u000a \\u000a \\u000a \\u000a \\u000a Methods This was a cross-sectional study on 271 patients with HIV infection attending an HIV clinic in Kota Bharu, Malaysia. Participants\\u000a completed the Malay version of the Functional
C. I. Hasanah; A. R. Zaliha; M. Mahiran
Influence of maternal dental anxiety on oral healthrelated quality of life of preschool children
Purpose The aim of this study was to determine the influence of maternal dental anxiety on perceptions about oral healthrelated quality\\u000a of life (OHRQoL) of preschool children.\\u000a \\u000a \\u000a \\u000a \\u000a Methods A cross-sectional study was conducted with 608 motherchild dyads during the Childrens National Immunization Campaign in\\u000a Pelotas, Brazil. Mothers answered a questionnaire on dental anxiety (DAS), socioeconomic status, use of dental services, and\\u000a perception
MarÚlia LeÐo Goettems; Thiago Machado Ardenghi; Ana Regina Romano; FlÃvio Fernando Demarco; Dione Dias Torriani
Multi-scale geomorphic and hydrogeologic influences on bull trout (Salvelinus confluentus) spawning habitat in headwater streams
NASA Astrophysics Data System (ADS)
We investigated multi-scale hydrogeomorphic influences on the distribution and abundance of bull trout (Salvelinus confluentus) spawning in snowmelt- dominated streams of the upper Flathead River basin, northwestern Montana. Bull trout redds were primarily found in unconfined alluvial valley reaches (74%), which were strongly influenced by hyporheic and groundwater-stream water exchange. A considerable proportion of redds (26%), however, were patchily distributed in confined valley reaches. Among all reaches and subreaches, the abundance of redds increased with increased bankfull dimensionless shear stress and decreased with reach-average streambed grain size (p < 0.05). Within these selected reaches and subreaches, redd occurrence tended to be associated with the finest available textural facies (i.e., gravel and small cobble substrates) in concave-up bedforms with downwelling intragravel flows. Streambed temperatures tracked stream water diurnal temperature cycles to a depth of at least 25 cm. Groundwater provided substantial thermal moderation of stream water for several high-density spawning reaches. Our spawning gravel competence results indicate that bull trout select spawning areas that are potentially susceptible to flooding-induced scour during the fall and winter incubation period.
Bean, J. R.; Wilcox, A. C.; Woessner, W. W.; Muhlfeld, C.
NSDL National Science Digital Library
_Urban Habitats_, published by the Center for Urban Restoration Ecology (CURE), is "a peer-reviewed, fully indexed scientific journal written and edited for a wide audience of researchers, restoration ecologists, park and preserve managers, government officials, and naturalists." The premier issue of this e-journal (focused on urban flora worldwide) is available online, and researchers are encouraged to submit articles and multimedia resources for future issues (detailed submission guidelines provided). CURE is a joint project of Rutgers University and the Brooklyn Botanic Garden.
NASA Technical Reports Server (NTRS)
The College of Engineering & Architecture at Prairie View A&M University has been participating in the NASA/USRA Advanced Design Program since 1986. The interdisciplinary nature of the program allowed the involvement of students and faculty throughout the College of Engineering & Architecture for the last five years. The research goal for the 1990-1991 year is to design a human habitat on Mars that can be used as a permanent base for 20 crew members. The research is being conducted by undergraduate students from the Department of Architecture.
75 FR 74545 - Endangered and Threatened Wildlife and Plants; Final Rule Designating Critical Habitat for...
Federal Register 2010, 2011, 2012, 2013
...information on the taxonomy, biology, and ecology of A. pumila, refer to the final listing...Species' Description, Life History, Ecology, Habitat, and Geographic Range and Status...pertaining to the description, life history, ecology, or habitat of Ambrosia pumila...
76 FR 6847 - Endangered and Threatened Wildlife and Plants; Final Revised Critical Habitat for Brodiaea...
Federal Register 2010, 2011, 2012, 2013
...information on the taxonomy, biology, and ecology of B. filifolia, refer to the final...Species' Description, Life History, Ecology, Habitat, and Geographic Range and Status...pertaining to the description, life history, ecology, habitat, geographic range, or...
Habitat quality affects early physiology and subsequent neuromotor development of juvenile black-capped chickadees.
In songbirds, the ability to learn and render the species-specific song is influenced by the development of both the song nuclei in the brain and the syrinx (bird's vocal apparatus) early in the bird's life. In black-capped chickadees (Poecille atricapillus), habitat quality is known to affect song structure, with birds in high-quality habitat (mature forest) having a higher song consistency than birds in low-quality habitat (young forest). Although this difference is suspected to stem from differences in development, the developmental status of juvenile birds in either habitat remains unexplored. In this study, we used ptilochronology and feather corticosterone to compare the conditional state of juvenile chickadees in young and mature forest during two distinct periods of song learning - the sensory phase, which occurs prior to settlement, and the sensorimotor phase, which occurs post-settlement. A sample of juvenile males was captured and euthanized several weeks prior to their first breeding season to compare the development of song center nuclei and syrinx in both habitats. The corticosterone levels of natally-grown feathers were greater among birds that settled in mature than young forests - as these feathers were grown pre-settlement, they reflect differences in physiology during the sensory phase. This difference in conditional state is reflected by differences in syrinx and song center nuclei development later during the sensorimotor phase - birds in young forest have smaller syrinx, and moderately-larger RA, than birds in mature forest. Those differences could be responsible for the difference in consistency in song structure observed across habitats. The difference in physiological state across habitats, combined with potential compounding effect of differences in winter resources between habitats, could influence the difference in syrinx and neural development seen in juvenile males during the early spring, and influence the male's ability to learn and render their species-specific song. PMID:23951257
Grava, Thibault; Fairhurst, Graham D; Avey, Marc T; Grava, Angelique; Bradley, James; Avis, Jillian L; Bortolotti, Gary R; Sturdy, Christopher B; Otter, Ken A
Habitat Quality Affects Early Physiology and Subsequent Neuromotor Development of Juvenile Black-Capped Chickadees
In songbirds, the ability to learn and render the species-specific song is influenced by the development of both the song nuclei in the brain and the syrinx (bird's vocal apparatus) early in the bird's life. In black-capped chickadees (Poecille atricapillus), habitat quality is known to affect song structure, with birds in high-quality habitat (mature forest) having a higher song consistency than birds in low-quality habitat (young forest). Although this difference is suspected to stem from differences in development, the developmental status of juvenile birds in either habitat remains unexplored. In this study, we used ptilochronology and feather corticosterone to compare the conditional state of juvenile chickadees in young and mature forest during two distinct periods of song learning - the sensory phase, which occurs prior to settlement, and the sensorimotor phase, which occurs post-settlement. A sample of juvenile males was captured and euthanized several weeks prior to their first breeding season to compare the development of song center nuclei and syrinx in both habitats. The corticosterone levels of natally-grown feathers were greater among birds that settled in mature than young forests - as these feathers were grown pre-settlement, they reflect differences in physiology during the sensory phase. This difference in conditional state is reflected by differences in syrinx and song center nuclei development later during the sensorimotor phase - birds in young forest have smaller syrinx, and moderately-larger RA, than birds in mature forest. Those differences could be responsible for the difference in consistency in song structure observed across habitats. The difference in physiological state across habitats, combined with potential compounding effect of differences in winter resources between habitats, could influence the difference in syrinx and neural development seen in juvenile males during the early spring, and influence the male's ability to learn and render their species-specific song.
Grava, Thibault; Fairhurst, Graham D.; Avey, Marc T.; Grava, Angelique; Bradley, James; Avis, Jillian L.; Bortolotti, Gary R.; Sturdy, Christopher B.; Otter, Ken A.
Microbiome analysis among bats describes influences of host phylogeny, life history, physiology and geography.
Metagenomic methods provide an experimental approach to inform the relationships between hosts and their microbial inhabitants. Previous studies have provided the conceptual realization that microbiomes are dynamic among hosts and the intimacy of relation between micro- and macroorganisms. Here, we present an intestinal microflora community analysis for members of the order Chiroptera and investigate the relative influence of variables in shaping observed microbiome relationships. The variables ranged from those considered to have ancient and long-term influences (host phylogeny and life history) to the relatively transient variable of host reproductive condition. In addition, collection locality data, representing the geographic variable, were included in analyses. Results indicate a complex influence of variables in shaping sample relationships in which signal for host phylogeny is recovered at broad taxonomic levels (family), whereas intrafamilial analyses disclosed various degrees of resolution for the remaining variables. Although cumulative probabilities of assignment indicated both reproductive condition and geography influenced relationships, comparison of ecological measures among groups revealed statistical differences between most variable classifications. For example, ranked ecological diversity was associated with host phylogeny (deeper coalescences among families were associated with more microfloral diversity), dietary strategy (herbivory generally retained higher diversity than carnivory) and reproductive condition (reproductively active females displayed more diverse microflora than nonreproductive conditions). Overall, the results of this study describe a complex process shaping microflora communities of wildlife species as well as provide avenues for future research that will further inform the nature of symbiosis between microflora communities and hosts. PMID:22519571
Phillips, Caleb D; Phelan, Georgina; Dowd, Scot E; McDonough, Molly M; Ferguson, Adam W; Delton Hanson, J; Siles, Lizette; Ordµþez-Garza, NictÕ; San Francisco, Michael; Baker, Robert J
Lunar and Planetary Bases, Habitats, and Colonies.
National Technical Information Service (NTIS)
This special bibliography includes the design and construction of lunar and Mars bases, habitats, and settlements; construction materials and equipment; life support systems; base operations and logistics; thermal management and power systems; and robotic...
Blood parasites in noddies and boobies from Brazilian offshore islands - differences between species and influence of nesting habitat.
Seabirds are often free from blood parasites, and a recent review suggested that phylogenetic, ecological and life-history parameters can determine the prevalence of blood parasites in seabirds. However, there is a lack of data available from many seabird groups, and a larger database is needed to understand prevalence patterns of blood parasites. We used a molecular screening approach to detect parasites of the genera Plasmodium, Haemoproteus, Leucocytozoon and Babesia in five species of two genera of seabirds that breed on Atlantic Ocean islands off Brazil. The observed patterns differed between the two bird genera. Like other Laridae, brown noddy, Anous stolidus adults were infected with Haemoproteus with low prevalence. Masked boobies, Sula dactylatra and brown boobies, Sula leucogaster were infected with Babesia. Of the latter, mainly juveniles were infected. In all species, intensity of infection (i.e. number of infected erythrocytes) was so low that parasites remained undetected in blood smears. This may explain the absence of major effects on the body condition of birds, although infected juvenile masked boobies were lighter than juveniles that were not infected with Babesia. Two tree-nesting species; black noddy, Anous minutus and red-footed booby, Sula sula did not have blood parasites, suggesting that tree-nesting may reduce the exposure to arthropod vectors compared with ground nesting in these species. PMID:24229724
Quillfeldt, Petra; MartÚnez, Javier; Bugoni, Leandro; Mancini, PatrÚcia L; Merino, Santiago
Factors influencing subjective quality of life in patients with schizophrenia and other mental disorders: A pooled analysis
Subjective quality of life (SQOL) is an important outcome in the treatment of patients with schizophrenia. However, there is only limited evidence on factors influencing SQOL, and little is known about whether the same factors influence SQOL in patients with schizophrenia and other mental disorders. This study aimed to identify the factors associated with SQOL and test whether these factors
Stefan Priebe; Ulrich Reininghaus; Rosemarie McCabe; Tom Burns; Mona Eklund; Lars Hansson; Ulrich Junghan; Thomas Kallert; Chijs van Nieuwenhuizen; Mirella Ruggeri; Mike Slade; Duolao Wang
When giants turn up: sighting trends, environmental influences and habitat use of the manta ray Manta alfredi at a coral reef.
Manta rays Manta alfredi are present all year round at Lady Elliot Island (LEI) in the southern Great Barrier Reef, Australia, with peaks in abundance during autumn and winter. Drivers influencing these fluctuations in abundance of M. alfredi at the site remain uncertain. Based on daily count, behavioural, weather and oceanographic data collected over a three-year period, this study examined the link between the relative number of sightings of manta rays at LEI, the biophysical environment, and the habitat use of individuals around the LEI reef using generalised additive models. The response variable in each of the three generalised additive models was number of sightings (per trip at sea) of cruising, cleaning or foraging M. alfredi. We used a set of eleven temporal, meteorological, biological, oceanographic and lunar predictor variables. Results for cruising, cleaning and foraging M. alfredi explained 27.5%, 32.8% and 36.3% of the deviance observed in the respective models and highlighted five predictors (year, day of year, wind speed, chlorophyll-a concentration and fraction of moon illuminated) as common influences to the three models. There were more manta rays at LEI in autumn and winter, slower wind speeds, higher productivity, and around the new and full moon. The winter peak in sightings of foraging M. alfredi was found to precede peaks in cleaning and cruising activity around the LEI reef, which suggests that enhanced food availability may be a principal driver for this seasonal aggregation. A spatial analysis of behavioural observations highlighted several sites around the LEI reef as 'multi-purpose' areas where cleaning and foraging activities commonly occur, while the southern end of the reef is primarily a foraging area. The use of extensive citizen science datasets, such as those collected by dive operators in this study, is encouraged as they can provide valuable insights into a species' ecology. PMID:23056255
Jaine, Fabrice R A; Couturier, Lydie I E; Weeks, Scarla J; Townsend, Kathy A; Bennett, Michael B; Fiora, Kym; Richardson, Anthony J
Detection and Influence of Shrinkage Pores and Nonmetallic Inclusions on Fatigue Life of Cast Aluminum Alloys
NASA Astrophysics Data System (ADS)
In the current study, test bars of cast aluminum alloys EN AC-AlSi8Cu3 and EN AC-AlSi7Mg0.3 were produced with a defined amounts of shrinkage pores and oxides. For this purpose, a permanent mold with heating and cooling devices for the generation of pores was constructed. The oxides were produced by contaminating the melt. The specimens and their corresponding defect distributions were examined and quantified by X-ray computer tomography (CT) and quantitative metallography, respectively. A special test algorithm for the simultaneous image analyses of pores and oxides was developed. Fatigue tests were conducted on the defective samples. It was found that the presence of shrinkage pores lowers the fatigue strength, and only few oxide inclusions were found to initiate fatigue cracks when shrinkage pores are present. The results show that the pore volume is not sufficient to characterize the influence of shrinkage pores on fatigue life. A parametric model for the calculation of fatigue life based on the pore parameters obtained from CT scans was implemented. The model accounts for the combined impact of pore location, size, and shape on fatigue life reduction.
Tijani, Yakub; Heinrietz, AndrÕ; Stets, Wolfram; Voigt, Patrick
[Alzheimer's disease influence on the perception of quality of life from the elderly people].
This study aims to compare the general perception and each dimension of the quality of life (QoL) of an elderly group with Alzheimer's Disease (AD) (n = 53) to those of a similar group regarding the socio-demographic variables (n = 53). The QoL measures were obtained through an Assessment Scale of the Quality of life in Alzheimer's Disease, and the data were typed into a database in the program Statistical Program for Social Sciences for the execution of the statistical analysis (descriptive, Student's t-test, Mann-Whitney and Chi-Square). Results showed that all dimensions of QoL measured by the instrument were statistically inferior in the group of elderly with AD. Regarding the total scores of QoL, the mean was 40.18 points for elderly without AD and 29.32 for elderly with AD, t(104) = 9.449, p < 0.001. These results indicate that older people with AD present inferior levels of QoL, which suggests that AD has a negative influence in their perception of quality of life. PMID:21337795
Inouye, Keika; Pedrazzani, Elisete Silva; Pavarini, Sofia Cristina Iost
Influence of Bovine Slurry Deposition on the Structure of Nodulating Rhizobium leguminosarum bv. viciae Soil Populations in a Natural Habitat
The population of nodulating R. leguminosarum bv. viciae in soil from a grass-covered valley area which had been used for bovine slurry deposition over a period of 5 years was analyzed. For these studies, a rapid and reproducible method based on enterobacterial repetitive intergenic consensus (ERIC)-PCR was applied to identify Rhizobium strains which had infected pea nodules. Soil samples were taken from different areas and further analyzed in plant tests to determine the impact of the application of slurry (polluted or nonpolluted), the slope position (summit or toe), and exposure (north or south). After comparison of all PCR fingerprint patterns, 24 strain groups were defined. Some strain groups from the nonpolluted soil were suppressed in the polluted samples, and new strain groups were detected in the slurry-polluted soil. After analyzing relationships between the strain groups, we determined the influences of local factors on the nodulating R. leguminosarum bv. viciae population. We show that one of those local parameters, slope position, had significantly greater impact on the composition of the Rhizobium population than the presence of slurry.
Labes, G.; Ulrich, A.; Lentzsch, P.
Habitat provides a variety of life support functions for many species, such as providing shelter, substrate, food, and nursery areas. Habitat alteration is one of the most important causes of declines in ecological resources in North America, and habitats essential to the well b...
How Does Chronic Back Pain Influence Quality of Life in Koreans: A Cross-Sectional Study
Study Design A cross-sectional study. Purpose To explore the impact of chronic low back pain (CLBP) on individuals' quality of life; to understand current treatment practices and level of satisfaction with treatment in patients with CLBP. Overview of Literature Assessing subjective, patient-reported outcomes such as quality of life is essential to health care research. Methods Influences of the CLBP were analyzed via a questionnaire, which contained the character of CLBP, effect of pain management, Korean version Oswestry Disability Index (K-ODI) and Korean version of 12-item Short Form Health Survey (SF-12v2). Results Of 3,121 subjects who responded, 67.3% had moderate to severe pain; 43.5% presented prolonged CLBP of more than two years; and 32.4% had suffered from sleep disturbance due to pain. 22.8% of the patients were not satisfied with current pain management. The mean K-ODI score was 37.63; and it was positively correlated with the mean pain intensity (r=0.6, p<0.001). The SF-12v2 result was negatively correlated with mean pain intensity (PCS: r=-0.5, p<0.001; MCS: r=-0.4, p<0.001) and also negatively correlated with the K-ODI score (PCS: r=-0.75, p<0.001; MCS: r=-0.5, p<0.001). The conformity between patients and doctors in pain assessment was fair (?=0.2463). Conclusions CLBP negatively affects quality of life. Of total 22.8% of the patients were not satisfied with current pain management. Such needs to be taken more seriously by doctors for improvement of satisfaction and quality of life in patients with CLBP.
Choi, Yong Soo; Kim, Dong Jun; Lee, Kyu Yeol; Park, Ye Soo; Cho, Kyu Jung; Lee, Jae Hyup; Rhim, Hyou Young
Life expectancy of modular Ti6Al4V hip implants: influence of stress and environment.
Stress dependent electrochemical dissolution is identified as one of the key mechanisms governing surface degradation in fretting and crevice corrosion of biomedical implants. The present study focuses on delineating the roles of mechanical stress and chemical conditions on the life expectancy of modular hip implants. First, material removal on a stressed surface of Ti6Al4V subjected to single asperity contact is investigated experimentally to identify the influence of contact load, in-plane stress and chemical environment on mean wear rates. A range of known stress levels are applied to the specimen while its surface is mechanically stimulated in different non-reactive to oxidizing aqueous environments. Evolution of surface degradation is monitored, and its mechanism is elucidated. This phase allows estimation of Preston Constant which is later used in the analysis. Second phase of the work is semi-analytical and computational, where, based on the estimated Preston constant and other material and process parameters, the scratch propensity (consisting of magnitude of scratch depth and their frequency per unit area) due to micro-motion in modular hip implants is estimated. The third phase views these scratches as initial notches and utilizes a mixed-mode fatigue crack propagation model to estimate the critical crack length for onset of instability. The number of loading cycles needed to reach this critical crack length is then labeled as the expected life of the implant under given mechanical and chemical conditions. Implications of different material and process conditions to life expectancy of orthopedic implants are discussed. It is observed that transverse micro-motion, compared to longitudinal micro-motion, plays a far more critical role in determining the implant life. Patient body weight, as well as proximity of the joint fluid to its iso-electric point play key roles in determining wear rates and associated life expectancies of modular hip implants. Sustained aeration of joint fluid, as well as proper tolerancing of mating surfaces, along with a proper choice of material microstructure may be utilized to extend implant life. PMID:22098898
Chandra, A; Ryu, J J; Karra, P; Shrotriya, P; Tvergaard, V; Gaisser, M; Weik, T
Slipping through the Cracks: Rubber Plantation Is Unsuitable Breeding Habitat for Frogs in Xishuangbanna, China
Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province a hotspot of frog diversity within China two-thirds of the native tropical rainforests have been converted into rubber plantation agriculture. We conducted surveys and experiments to quantify habitat use for breeding and non-breeding life history activities of the native frog species in rainforest, rubber plantation and other human impacted sites. Rubber plantation sites had the lowest species richness in our non-breeding habitat surveys and no species used rubber plantation sites as breeding habitat. The absence of breeding was likely not due to intrinsic properties of the rubber plantation pools, as our experiments indicated that rubber plantation pools were suitable for tadpole growth and development. Rather, the absence of breeding in the rubber plantation was likely due to a misalignment of breeding and non-breeding habitat preferences. Analyses of our breeding surveys showed that percent canopy cover over pools was the strongest environmental variable influencing breeding site selection, with species exhibiting preferences for pools under both high and low canopy cover. Although rubber plantation pools had high canopy cover, the only species that bred in high canopy cover sites used the rainforest for both non-breeding and breeding activities, completing their entire life cycle in the rainforest. Conversely, the species that did use the rubber plantation for non-breeding habitat preferred to breed in low canopy sites, also avoiding breeding in the rubber plantation. Rubber plantations are likely an intermediate habitat type that slips through the cracks of species habitat preferences and is thus avoided for breeding. In summary, unlike the rainforests they replaced, rubber plantations alone may not be able to support frog populations.
Behm, Jocelyn E.; Yang, Xiaodong; Chen, Jin
Slipping through the cracks: rubber plantation is unsuitable breeding habitat for frogs in Xishuangbanna, China.
Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province - a hotspot of frog diversity within China - two-thirds of the native tropical rainforests have been converted into rubber plantation agriculture. We conducted surveys and experiments to quantify habitat use for breeding and non-breeding life history activities of the native frog species in rainforest, rubber plantation and other human impacted sites. Rubber plantation sites had the lowest species richness in our non-breeding habitat surveys and no species used rubber plantation sites as breeding habitat. The absence of breeding was likely not due to intrinsic properties of the rubber plantation pools, as our experiments indicated that rubber plantation pools were suitable for tadpole growth and development. Rather, the absence of breeding in the rubber plantation was likely due to a misalignment of breeding and non-breeding habitat preferences. Analyses of our breeding surveys showed that percent canopy cover over pools was the strongest environmental variable influencing breeding site selection, with species exhibiting preferences for pools under both high and low canopy cover. Although rubber plantation pools had high canopy cover, the only species that bred in high canopy cover sites used the rainforest for both non-breeding and breeding activities, completing their entire life cycle in the rainforest. Conversely, the species that did use the rubber plantation for non-breeding habitat preferred to breed in low canopy sites, also avoiding breeding in the rubber plantation. Rubber plantations are likely an intermediate habitat type that 'slips through the cracks' of species habitat preferences and is thus avoided for breeding. In summary, unlike the rainforests they replaced, rubber plantations alone may not be able to support frog populations. PMID:24040026
Behm, Jocelyn E; Yang, Xiaodong; Chen, Jin
Habitat and Scale Shape the Demographic Fate of the Keystone Sea Urchin Paracentrotus lividus in Mediterranean Macrophyte Communities
Demographic processes exert different degrees of control as individuals grow, and in species that span several habitats and spatial scales, this can influence our ability to predict their population at a particular life-history stage given the previous life stage. In particular, when keystone species are involved, this relative coupling between demographic stages can have significant implications for the functioning of ecosystems. We examined benthic and pelagic abundances of the sea urchin Paracentrotus lividus in order to: 1) understand the main life-history bottlenecks by observing the degree of coupling between demographic stages; and 2) explore the processes driving these linkages. P. lividus is the dominant invertebrate herbivore in the Mediterranean Sea, and has been repeatedly observed to overgraze shallow beds of the seagrass Posidonia oceanica and rocky macroalgal communities. We used a hierarchical sampling design at different spatial scales (100 s, 10 s and <1 km) and habitats (seagrass and rocky macroalgae) to describe the spatial patterns in the abundance of different demographic stages (larvae, settlers, recruits and adults). Our results indicate that large-scale factors (potentially currents, nutrients, temperature, etc.) determine larval availability and settlement in the pelagic stages of urchin life history. In rocky macroalgal habitats, benthic processes (like predation) acting at large or medium scales drive adult abundances. In contrast, adult numbers in seagrass meadows are most likely influenced by factors like local migration (from adjoining rocky habitats) functioning at much smaller scales. The complexity of spatial and habitat-dependent processes shaping urchin populations demands a multiplicity of approaches when addressing habitat conservation actions, yet such actions are currently mostly aimed at managing predation processes and fish numbers. We argue that a more holistic ecosystem management also needs to incorporate the landscape and habitat-quality level processes (eutrophication, fragmentation, etc.) that together regulate the populations of this keystone herbivore.
Prado, Patricia; Tomas, Fiona; Pinna, Stefania; Farina, Simone; Roca, Guillem; Ceccherelli, Giulia; Romero, Javier; Alcoverro, Teresa
Spatial and temporal shifts in suitable habitat of juvenile southern flounder (Paralichthys lethostigma)
NASA Astrophysics Data System (ADS)
Factors influencing suitable habitats of juvenile southern flounder (Paralichthys lethostigma) within the Galveston Bay Complex (GBC), Texas, were assessed using generalized additive models (GAM). Fishery independent data collected with bag seines throughout the GBC from 1999 to 2009 were used to predict the probability of southern flounder occurrence. Binomial GAMs were used to assess presence/absence of southern flounder and models included temporal variables, benthic variables such as distance to habitats generated within a geographic information system, and physicochemical conditions of the water column. Separate models were generated for newly settled southern flounder, young-of-the-year (YOY) southern flounder observed in the summer, and YOY southern flounder observed in fall based on size and collection month. Factors affecting southern flounder occurrence changed seasonally, as did the corresponding shifts in the spatial distribution of suitable habitat. Temporal effects (year and month) were retained in all models. Physicochemical conditions (temperature, turbidity, and measures of environmental variability), and the presence of seagrass beds were influential for newly settled southern flounder. Distance to marine and/or freshwater sources were found to be important for YOY southern flounder in the summer and fall seasons. The abundance of brown shrimp was found to only influence the distribution of YOY southern flounder in the fall, when intermediate abundances of the potential prey item increased the occurrence of southern flounder. After model completion, the availability and spatial distribution of suitable habitat within the GBC was predicted using available environmental and spatial data for 2005. Spatial distributions of predicted suitable habitat stress the relative importance of West Bay during the newly settled stage and in the fall season, and Upper Bay during the summer and fall of the first year of life. These models demonstrate the potential dynamics of suitable habitats for juvenile southern flounder and provide insight into ontogenetic shifts in habitat preference during the first year of life.
Furey, Nathan B.; Rooker, Jay R.
Habitat Management for Birds of West Virginia.
National Technical Information Service (NTIS)
This report is a synthesis of existing literature and survey data for West Virginia birds. The objectives of this report are to summarize available bird population data for major habitat types in West Virginia, to indicate how changes in habitat influence...
S. H. Anderson C. S. Robbins J. R. Partelow
Aquatic vegetation is one of the most widespread and important types of aquatic habitat, in part because of the exceptional productivity of the plants. Aquatic vegetation also strongly influences local physical and chemical habitat conditions of significance to fish and shellfis...
NSDL National Science Digital Library
When a preschool teacher unexpectedly found tadpoles in the school's outdoor baby pool, she recognized an unusual opportunity for her students to study pond life up close. By following the tadpoles' development, students learned about frogs, life cycles, habitats.
Coffey, Audrey L.; Sterling, Donna R.
Habitat Complexity, Brain, and Behavior
More complex brains and behaviors have arisen repeatedly throughout both vertebrate and invertebrate evolution. The challenge is to tease apart the forces underlying such change. In this review, I show how habitat complexity influences both brain and behavior in African cichlid fishes, drawing on examples from primates and birds where appropriate. These species groups share a number of similarities. They
Caroly A. Shumway
Proportionate responses to life events influence clinicians' judgments of psychological abnormality.
Psychological abnormality is a fundamental concept in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; American Psychiatric Association, 2000) and in all clinical evaluations. How do practicing clinical psychologists use the context of life events to judge the abnormality of a person's current behaviors? The appropriate role of life-event context in assessment has long been the subject of intense debate and scrutiny among clinical theorists, yet relatively little is known about clinicians' own judgments in practice. The authors propose a proportionate-response hypothesis, such that judgments of abnormality are influenced by whether the behaviors are a disproportionate response to past events, rendering them difficult to understand or explain. Licensed, practicing clinical psychologists (N = 77) were presented with vignettes describing hypothetical people's behaviors (disordered, mildly distressed, or unaffected) that had been preceded by either traumatic or mildly distressing events. Experts' judgments of abnormality were strongly and systematically influenced by the degree of mismatch between the past event and current behaviors in strength and valence, such that the greater the mismatch, the more abnormal the person seemed. A separate, additional group of clinical psychologists (N = 20) further confirmed that the greater the degree of mismatch, the greater the perceived difficulty in understanding the patient. These findings held true across clinicians of different theoretical orientations and in disorders for which these patterns of judgments ran contrary to formal recommendations in the DSM-IV-TR (American Psychiatric Association, 2000). The rationality of these effects and implications for clinical decision science are discussed. PMID:22142425
Kim, Nancy S; Paulus, Daniel J; Gonzalez, Jeffrey S; Khalife, Danielle
Prevalence of Widespread Pain and Its Influence on Quality of Life: Population Study in Korea
The objective of this study was to examine the prevalence and risk factors for widespread pain and its influence on quality of life in residents of Korean communities. A rural and an urban community were selected, and 5,037 subjects were surveyed. Participants were asked if they had pain, aching, or stiffness in any of their joints on most days. Widespread pain was defined as pain above the waist, below the waist, on both sides of the body and in the axial region. The prevalence of widespread pain was 12% (16.2% and 5.5% in females and males, respectively). It was more frequent among females and increased with age in both genders. Age, female gender, and the presence of hand or knee arthritis were significantly associated with widespread pain after multivariate analysis. Except for mental health, all the items in the SF-12 were adversely affected in the widespread pain group after adjustment for confounding factors. Our findings show that the prevalence of widespread pain among residents of Korean communities is comparable to that reported among Caucasians. The significantly worse quality of life among subjects with widespread pain suggests that it may cause major health issues in the aging population.
Cho, Nam Han; Kim, Inje; Lim, Seung Hun
Dementia and its influence on quality of life and what it means to be valued: Family members' perceptions.
This pragmatic, exploratory qualitative study, as part of a larger funded research project, sought to explore families' perspectives on what it means to value a person with dementia and how this value might influence the quality of life of people with dementia. In-depth interviews were conducted with 20 family members who used one long-term care service provider in Australia. Families described the factors influencing a positive quality of life for the person with dementia as being related to the environment and, in particular, to the resident's room, supportive staff and individualised care that valued the person's life experience. Family also reported a negative impact on quality of life when staff and the care facility neglected to provide an individualised approach. This study highlights the importance of demonstrating the value of the person with dementia, the family role and partnerships of care. PMID:24339065
Moyle, Wendy; Murfield, Jenny; Venturto, Lorraine; Griffiths, Susan; Grimbeek, Peter; McAllister, Margaret; Marshall, Jenni
Volcaniclastic habitats for early life on Earth and Mars: A case study from ?3.5 Ga-old rocks from the Pilbara, Australia
Within the context of present and future in situ missions to Mars to investigate its habitability and to search for traces of life, we studied the habitability and traces of past life in ?3.5Ga-old volcanic sands deposited in littoral environments an analogue to Noachian environments on Mars. The environmental conditions on Noachian Mars (4.13.7Ga) and the Early Archaean (4.03.3Ga) Earth
Frances Westall; FrÕdÕric Foucher; Barbara Cavalazzi; Sjoukje T. de Vries; Wouter Nijman; Victoria Pearson; Jon Watson; Alexander Verchovsky; Ian Wright; Jean-Noel Rouzaud; Daniele Marchesini; Severine Anne
Growth history and intrinsic factors influence risk assessment at a critical life transition for a fish
NASA Astrophysics Data System (ADS)
Making the appropriate decision in the face of predation risk dictates the fate of prey, and predation risk is highest at life history boundaries such as settlement. At the end of the larval phase, most coral reef fishes enter patches of reef containing novel predators. Since vision is often obscured in the complex surroundings, chemical information released from damaged conspecific is used to forewarn prey of an active predator. However, larvae enter the reef environment with their own feeding and growth histories, which will influence their motivation to feed and take risks. The present study explored the link between recent growth, feeding history, current performance and behavioural risk taking in newly settling stages of a coral reef damselfish ( Pomacentrus amboinensis). Older and larger juveniles in good body condition had a stronger response to chemical alarm cues of injured conspecifics; these fish spent a longer time in shelter and displayed a more dramatic decrease in foraging behaviour than fish in lower body condition. Feeding experiments supported these findings and emphasized the importance of body condition in affecting risk assessment. Evidently, larval growth history and body condition influences the likelihood of taking risks under the threat of predation immediately after settlement, thereby affecting the probability of survival in P. amboinensis.
L—nnstedt, O. M.; McCormick, M. I.
Alcohol Response and Consumption in Adolescent Rhesus Macaques: Life History and Genetic Influences
The use of alcohol by adolescents is a growing problem and has become an important research topic in the etiology of the alcohol use disorders. A key component of this research has been the development of animal models of adolescent alcohol consumption and alcohol response. Due to their extended period of adolescence, rhesus macaques are especially well-suited for modeling alcohol-related phenotypes that contribute to the adolescent propensity for alcohol consumption. In this review, we discuss studies from our laboratory that have investigated both the initial response to acute alcohol administration and the consumption of alcohol in voluntary self-administration paradigms in adolescent rhesus macaques. These studies confirm that adolescence is a time of dynamic change both behaviorally and physiologically, and that alcohol response and alcohol consumption are influenced by life history variables such as age, sex, and adverse early experience in the form of peer-rearing. Furthermore, genetic variants that alter functioning of the serotonin, endogenous opioid, and corticotropin releasing hormone systems are shown to influence both physiological and behavioral outcomes, in some cases interacting with early experience to indicate gene by environment interactions. These findings highlight several of the pathways involved in alcohol response and consumption, namely reward, behavioral dyscontrol, and vulnerability to stress, and demonstrate a role for these pathways during the early stages of alcohol exposure in adolescence.
Schwandt, Melanie L.; Lindell, Stephen G.; Chen, Scott; Higley, J. Dee; Suomi, Stephen J.; Heilig, Markus; Barr, Christina S.
How emotional abilities modulate the influence of early life stress on hippocampal functioning.
Early life stress (ELS) is known to have considerable influence on brain development, mental health and affective functioning. Previous investigations have shown that alexithymia, a prevalent personality trait associated with difficulties experiencing and verbalizing emotions, is particularly related to ELS. The aim of the present study was to investigate how neural correlates of emotional experiences in alexithymia are altered in the presence and absence of ELS. Therefore, 50 healthy individuals with different levels of alexithymia were matched regarding ELS and investigated with respect to neural correlates of audio-visually induced emotional experiences via functional magnetic resonance imaging. The main finding was that ELS modulated hippocampal responses to pleasant (>neutral) stimuli in high-alexithymic individuals, whereas there was no such modulation in low-alexithymic individuals matched for ELS. Behavioral and psychophysiological results followed a similar pattern. When considered independent of ELS, alexithymia was associated with decreased responses in insula (pleasant > neutral) and temporal pole (unpleasant > neutral). Our results show that the influence of ELS on emotional brain responses seems to be modulated by an individual's degree of alexithymia. Potentially, protective and adverse effects of emotional abilities on brain responses to emotional experiences are discussed. PMID:23685776
Aust, Sabine; Alkan Hðrtwig, Elif; Koelsch, Stefan; Heekeren, Hauke R; Heuser, Isabella; Bajbouj, Malek
Survival of freezing by hydrated tardigrades inhabiting terrestrial and freshwater habitats.
The seasonality and unpredictability of environmental conditions at high altitudes and latitudes govern the life cycle patterns of organisms, giving rise to stresses that cause death or development of specific adaptations. Ice formation is a major variable affecting the survival of both freshwater fauna and fauna inhabiting lichens, mosses and leaf litter. Tardigrades occupy a wide range of niches in marine, freshwater and terrestrial environments. The highest number of species is found in terrestrial habitats thanks to their ability to enter anhydrobiosis and cryobiosis. The cryobiotic ability of tardigrade species from polar regions is well known. Consequently, we focused our research on the ability to survive freezing in the active hydrated state using seven tardigrade species differing in phylogenetic position and collected at various altitudes and from different habitats in a temperate area. Specimens were cooled at different cooling rates (from 0.31¯ C min(-1) to 3.26¯ C min(-1)). Even though the final survival and the time required by animals to recover to active life were both inversely related to the cooling rate, highly significant interspecific differences were found. Species survival ability ranged from excellent to none. Species living in xeric habitats withstood freezing better than those living in hygrophilous habitats, while true limnic species did not exhibit any cryobiotic ability. The ability to withstand freezing seems linked to the anhydrobiotic ability. The differences in cryptobiotic performance among tardigrade species seem more influenced by selective pressures linked to local adaptation to habitat characteristics than by phylogenetic relationships. PMID:21429723
Guidetti, Roberto; Altiero, Tiziana; Bertolani, Roberto; Grazioso, Pasqualina; Rebecchi, Lorena
Many anthropogenic activities exert their influence on fish, shellfish and aquatic-dependent wildlife by affecting habitats. In fact, habitat alteration is one of the most important contributors to declines in ecological resources in North America. Habitat loss and degradation ar...
Habitat characteristics affecting fish assemblages on a Hawaiian coral reef
Habitat characteristics of a reef were examined as potential influences on fish assemblage structure, using underwater visual census to estimate numbers and biomass of all fishes visible on 42 benthic transects and making quantitative measurements of 13 variables of the corresponding physical habitat and sessile biota. Fish assemblages in the diverse set of benthic habitats were grouped by detrended correspondence
Alan M Friedlander; James D Parrish
Management of habitat for rehabilitation and enhancement of salmonid stocks
Most of the river systems in the British Isles have been subjected to anthropogenic influence to varying degrees over recent times, in many instances leading to deleterious impacts on salmonid habitat to the detriment of populations. This paper considers the range of management options that can be utilised to overcome habitat degradation. When examining salmonid habitat management three areas need
K Hendry; D Cragg-Hine; M OGrady; H Sambrook; A Stephen
Fragmentation of habitats used by neotropical migratory birds in Southern Appalachians and the neotropics
Recent declines in North American breeding populations have sparked great concern over the effects of habitat fragmentation. Neotropical migrant birds use and are influenced by two biomes during a single life span. Yet assessment of the relative importance of changes in tropical wintering areas versus temperate breeding areas is complicated by regional variation in rates and extent of habitat change. Landscape-level measurements of forest fragmentation derived from remotely-sensed data provide a means to compare the patterns of habitat modification on the wintering and breeding grounds of migrant birds. This study quantifies patterns of forest fragmentation in the Southern Appalachian Mountains and tropical Amazon and relates these patterns to the resource needs of neotropical migrant birds. Study sites were selected from remotely-sensed images to represent a range of forest fragmentation (highly fragmented landscape to continuous forest).
Pearson, S.M.; Dale, V.H. [Oak Ridge National Lab., TN (United States); Offerman, H.L. [Oak Ridge National Lab., TN (United States)]|[Oak Ridge Associated Universities, Inc., TN (United States)
Subsurface microbial habitats on Mars
NASA Technical Reports Server (NTRS)
We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.
Boston, P. J.; Mckay, C. P.
Mineral interface in extreme habitats: A niche for primitive molecular evolution for the appearance of different forms of life on Earth
Innumerable primitive membrane and protocell models in latter stages of chemical evolution are based on the properties of minerals' interfaces with primitive seawater. The ordering mechanism induced by mineral interfaces has been the basis of several prebiotic models of molecular complexification and compartmentalization towards the appearance and evolution of different forms of life. Since mineralaqueous media interfaces have been considered
Fernando de Souza-Barros; Adalberto Vieyra
Campus Habitat Improvement Plan
NSDL National Science Digital Library
In working with students to provide suitable habitat for species of interest, teachers can begin to develop the school campus into an outdoor classroom. Students will build self-esteem while obtaining useful real-life skills related to ecological practices. Students will have the opportunity to work with professionals from related fields of study. The hands-on activities give students a chance to put into practice the theories and themes that have been studied in a closed classroom setting. Students will learn to read aerial photographs, perform biological surveys, and write wildlife management plans. They will carry out management practices on the campus site and learn to evaluate the success of their program.
BEGIN:VCARD VERSION:2.1 FN:Francis Carter N:Carter;Francis ORG:Somerset High School REV:2005-04-15 END:VCARD
Influence and interaction of genetic polymorphisms in the serotonin system and life stress on antidepressant drug response
Variation in genes implicated in serotonin neurotransmission may interact with environmental factors to influence antidepressant response. We aimed to determine how a range of polymorphisms in serotonergic genes determine this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample. In total, 14 single nucleotide polymorphisms (SNPs) in coding regions of 10
Zhi Xu; Zhijun Zhang; Yanyan Shi; Mengjia Pu; Yonggui Yuan; Xiangrong Zhang; Lingjiang Li; Gavin P Reynolds
Demographic and environmental influences on life-history traits of isolated populations of the Andean catfish Astroblepus ubidiai
In this study, we examined the influence of demographic and environmental variables on the life histories of six remnant populations of the Andean catfishAstroblepus ubidiai (Actinopterygii; Siluriform) located in isolated refuges, and tested six predictions on the relationships between age at maturity, generation time, population density and juvenile and adult growth and survival rates. The three populations inhabiting the watershed
Luis A. VÕlez-Espino; Michael G. Fox
Susceptibility of eastern U.S. habitats to invasion of Celastrus orbiculatus (oriental bittersweet) following fire
Fire effects on invasive species are an important land management issue in areas subjected to prescribed fires as well as wildfires. These effects on invasive species can be manifested across life stages. The liana Celastrus orbiculatus (oriental bittersweet) is a widespread invader of eastern US habitats including those where fire management is in practice. This study examined if prescribed fire makes these habitats more susceptible to invasion of C. orbiculatus by seed at Indiana Dunes National Lakeshore. Four treatments (control, litter removed, high and low intensity fire) were applied in six habitat types (sand savanna/woodland, sand prairie, moraine prairie, sand oak forest, beech-maple forest, and oak-hickory forest) and germinating seedlings were tracked over two growing seasons. Treatment did not have a significant effect on the germination, survival, or biomass of C. orbiculatus. However, habitat type did influence these responses mostly in the first growing season. Moraine prairie, beech-maple forest, and oak-hickory forests had the greatest peak percentage of germinants. Moraine prairie had significantly greater survival than oak forest and savanna habitats. Control plots with intact litter, and the moraine prairie habitat had the tallest seedlings at germination, while tallest final heights and greatest aboveground biomass were highest in oak forest. Thus, fire and litter removal did not increase the susceptibility of these habitats to germination and survival of C. orbiculatus. These results indicate that most eastern US habitats are vulnerable to invasion by this species via seed regardless of the level or type of disturbance to the litter layer.
Leicht-Young, Stacey A.; Pavlovic, Noel B; Grundel, Ralph
Multi-scale Hydroacoustic Remote Sensing of Sturgeon and Their Habitats in A Large, Turbid River
Restoration and management of the Lower Missouri River (LMOR) to support recovery of the endangered pallid sturgeon (Scaphirhynchus albus) requires quantifying habitats used during all life stages in order to isolate specific habitats (if any) that present bottlenecks to reproduction and survival. All life stages of the pallid sturgeon take place in deep, turbid rivers where direct observation of habitat
R. B. Jacobson; A. Delonay; C. Vishy; C. M. Elliott; J. M. Reuter; K. A. Chojnacki
Life history influences rates of climatic niche evolution in flowering plants
Across angiosperms, variable rates of molecular substitution are linked with life-history attributes associated with woody and herbaceous growth forms. As the number of generations per unit time is correlated with molecular substitution rates, it is expected that rates of phenotypic evolution would also be influenced by differences in generation times. Here, we make the first broad-scale comparison of growth-form-dependent rates of niche evolution. We examined the climatic niches of species on large time-calibrated phylogenies of five angiosperm clades and found that woody lineages have accumulated fewer changes per million years in climatic niche space than related herbaceous lineages. Also, climate space explored by woody lineages is consistently smaller than sister lineages composed mainly of herbaceous taxa. This pattern is probably linked to differences in the rate of climatic niche evolution. These results have implications for niche conservatism; in particular, the role of niche conservatism in the distribution of plant biodiversity. The consistent differences in the rate of climatic niche evolution also emphasize the need to incorporate models of phenotypic evolution that allow for rate heterogeneity when examining large datasets.
Smith, Stephen A.; Beaulieu, Jeremy M.
Influence of the Qinghai-Tibetan railway on the habitat selection of wild animals, using satellite data and satellite-based ARGOS system data
NASA Astrophysics Data System (ADS)
The Qinghai-Tibet Railway (QTR) was in trial operation since 1 July 2006, is the world's highest-elevation railway and the longest highland railway, extending over 1956 km from Xining (Qinghai's capital in northwestern China) to Lhasa, the capital city of the Tibet Autonomous Region. This QTR railway was crosses five nature reserves along the route Hoh Xil (COCOX- ILI), Qinghai Sanjiangyuan, Chang Tang, Lin-chou Pengbo, and La-lu, and Hoh xil nature reserve is the important breeding sites of Tibetan Antelope (Pantholops hodgsoni). In order to clearly the habitat use and habitat selection of the Tibetan Antelope was divided in the north and south by the QTR railway, we planned the capture of ten Tibetan Antelopes and attach a satellite-based ARGOS system platform transmitter terminal (PTT) to the Tibetan Antelopes. And we succeeded in the capture of two Tibetan Antelopes for the first time in the world in 2007a summer and attached an ARGOS PTT. In this study, we estimate RASTER model of habitat change, using satellite-based ARGOS PTT tracking analyst data and satellite (Terra/MODIS, Terra/ASTER, ALOS and SPOT/vegetation instrument data) land cover change data, order to clearly the spatial and temporal characteristics of wide area habitat selection of Tibetan Antelope.
Buhe, Aosier
Influence of Habitat and Climate Variables on Arbuscular Mycorrhizal Fungus Community Distribution, as Revealed by a Case Study of Facultative Plant Epiphytism under Semiarid Conditions
In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats.
Torrecillas, E.; Torres, P.; Querejeta, J. I.; Roldan, A.
Influence of habitat and climate variables on arbuscular mycorrhizal fungus community distribution, as revealed by a case study of facultative plant epiphytism under semiarid conditions.
In semiarid Mediterranean ecosystems, epiphytic plant species are practically absent, and only some species of palm trees can support epiphytes growing in their lower crown area, such as Phoenix dactylifera L. (date palm). In this study, we focused on Sonchus tenerrimus L. plants growing as facultative epiphytes in P. dactylifera and its terrestrial forms growing in adjacent soils. Our aim was to determine the possible presence of arbuscular mycorrhizal fungi (AMF) in these peculiar habitats and to relate AMF communities with climatic variations. We investigated the AMF community composition of epiphytic and terrestrial S. tenerrimus plants along a temperature and precipitation gradient across 12 localities. Epiphytic roots were colonized by AMF, as determined by microscopic observation; all of the epiphytic and terrestrial samples analyzed showed AMF sequences from taxa belonging to the phylum Glomeromycota, which were grouped in 30 AMF operational taxonomic units. The AMF community composition was clearly different between epiphytic and terrestrial root samples, and this could be attributable to dispersal constraints and/or the contrasting environmental and ecophysiological conditions prevailing in each habitat. Across sites, the richness and diversity of terrestrial AMF communities was positively correlated with rainfall amount during the most recent growing season. In contrast, there was no significant correlation between climate variables and AMF richness and diversity for epiphytic AMF communities, which suggests that the composition of AMF communities in epiphytic habitats appears to be largely determined by the availability and dispersion of fungal propagules from adjacent terrestrial habitats. PMID:24038687
Torrecillas, E; Torres, P; Alguacil, M M; Querejeta, J I; RoldÃn, A
Historic Habitat Opportunities and Food-Web Linkages of Juvenile Salmon in the Columbia River Estuary, Annual Report of Research.
In 2002 with support from the U.S. Army Corps of Engineers (USACE), an interagency research team began investigating salmon life histories and habitat use in the lower Columbia River estuary to fill significant data gaps about the estuary's potential role in salmon decline and recovery . The Bonneville Power Administration (BPA) provided additional funding in 2004 to reconstruct historical changes in estuarine habitat opportunities and food web linkages of Columbia River salmon (Onchorhynchus spp.). Together these studies constitute the estuary's first comprehensive investigation of shallow-water habitats, including selected emergent, forested, and scrub-shrub wetlands. Among other findings, this research documented the importance of wetlands as nursery areas for juvenile salmon; quantified historical changes in the amounts and distributions of diverse habitat types in the lower estuary; documented estuarine residence times, ranging from weeks to months for many juvenile Chinook salmon (O. tshawytscha); and provided new evidence that contemporary salmonid food webs are supported disproportionately by wetland-derived prey resources. The results of these lower-estuary investigations also raised many new questions about habitat functions, historical habitat distributions, and salmon life histories in other areas of the Columbia River estuary that have not been adequately investigated. For example, quantitative estimates of historical habitat changes are available only for the lower 75 km of the estuary, although tidal influence extends 217 km upriver to Bonneville Dam. Because the otolith techniques used to reconstruct salmon life histories rely on detection of a chemical signature (strontium) for salt water, the estuarine residency information we have collected to date applies only to the lower 30 or 35 km of the estuary, where fish first encounter ocean water. We lack information about salmon habitat use, life histories, and growth within the long tidal-fresh reaches of the main-stem river and many tidally-influenced estuary tributaries. Finally, our surveys to date characterize wetland habitats within island complexes distributed in the main channel of the lower estuary. Yet some of the most significant wetland losses have occurred along the estuary's periphery, including shoreline areas and tributary junctions. These habitats may or may not function similarly as the island complexes that we have surveyed to date. In 2007 we initiated a second phase of the BPA estuary study (Phase II) to address specific uncertainties about salmon in tidal-fresh and tributary habitats of the Columbia River estuary. This report summarizes 2007 and 2008 Phase II results and addresses three principal research questions: (1) What was the historic distribution of estuarine and floodplain habitats from Astoria to Bonneville Dam? (2) Do individual patterns of estuarine residency and growth of juvenile Chinook salmon vary among wetland habitat types along the estuarine tidal gradient? (3) Are salmon rearing opportunities and life histories in the restoring wetland landscape of lower Grays River similar to those documented for island complexes of the main-stem estuary? Phase II extended our analysis of historical habitat distribution in the estuary above Rkm 75 to near Bonneville Dam. For this analysis we digitized the original nineteenth-century topographic (T-sheets) and hydrographic (H-sheets) survey maps for the entire estuary. Although all T-sheets (Rkm 0 to Rkm 206) were converted to GIS in 2005 with support for the USACE estuary project, final reconstruction of historical habitats throughout the estuary requires completion of the remaining H-sheet GIS maps above Rkm 75 and their integration with the T-sheets. This report summarizes progress to date on compiling the upper estuary H-sheets above Rkm 75. For the USACE estuary project, we analyzed otoliths from Chinook salmon collected near the estuary mouth in 2003-05 to estimate variability in estuary residence times among juvenile out migrants. In Phase II we expanded these analyses to comp
Bottom, Daniel L.; Simenstad, Charles A.; Campbell, Lance [Northwest Fisheries Science Center
Influences on Employee Perceptions of Organizational Work-Life Support: Signals and Resources
ERIC Educational Resources Information Center
This study examined predictors of employee perceptions of organizational work-life support. Using organizational support theory and conservation of resources theory, we reasoned that workplace demands and resources shape employees' perceptions of work-life support through two mechanisms: signaling that the organization cares about their work-life
Valcour, Monique; Ollier-Malaterre, Ariane; Matz-Costa, Christina; Pitt-Catsouphes, Marcie; Brown, Melissa
The effects of chemical interactions and culture history on the colonization of structured habitats by competing bacterial populations
Background Bacterial habitats, such as soil and the gut, are structured at the micrometer scale. Important aspects of microbial life in such spatial ecosystems are migration and colonization. Here we explore the colonization of a structured ecosystem by two neutrally labeled strains of Escherichia coli. Using time-lapse microscopy we studied the colonization of one-dimensional arrays of habitat patches linked by connectors, which were invaded by the two E. coli strains from opposite sides. Results The two strains colonize a habitat from opposite sides by a series of traveling waves followed by an expansion front. When population waves collide, they branch into a continuing traveling wave, a reflected wave and a stationary population. When the two strains invade the landscape from opposite sides, they remain segregated in space and often one population will displace the other from most of the habitat. However, when the strains are co-cultured before entering the habitats, they colonize the habitat together and do not separate spatially. Using physically separated, but diffusionally coupled, habitats we show that colonization waves and expansion fronts interact trough diffusible molecules, and not by direct competition for space. Furthermore, we found that colonization outcome is influenced by a cultures history, as the culture with the longest doubling time in bulk conditions tends to take over the largest fraction of the habitat. Finally, we observed that population distributions in parallel habitats located on the same device and inoculated with cells from the same overnight culture are significantly more similar to each other than to patterns in identical habitats located on different devices inoculated with cells from different overnight cultures, even tough all cultures were started from the same ?80¯C frozen stock. Conclusions We found that the colonization of spatially structure habitats by two interacting populations can lead to the formation of complex, but reproducible, spatiotemporal patterns. Furthermore, we showed that chemical interactions between two populations cause them to remain spatially segregated while they compete for habitat space. Finally, we observed that growth properties in bulk conditions correlate with the outcome of habitat colonization. Together, our data show the crucial roles of chemical interactions between populations and a cultures history in determining the outcome of habitat colonization.
Salmonid populations can be affected by alterations in stream physical habitat. Fish productivity is determined by the stream's physical habitat structure ( channel form, substrate distribution, riparian vegetation), water quality, flow regime and inputs from the watershed (sedim...
Enchanted Learning: Biomes-Habitats
NSDL National Science Digital Library
Created by Enchanted Learning, this kid-friendly Biome-Habitats website introduces children to many of the earth's biomes. Although the site provides basic information about many different biomes, the main emphasis is on the animals that live in each habitat. From the homepage, site visitors can link to almost twenty separate biome / habitat sites including Desert, Cave, Savanna, and Coral Reef-just too name a few. Each site presents a brief introduction covering general characteristics, such as plant life and climate, and then provides links to many separate animal pages ranging from grasshoppers to eagles. The animal pages feature nice diagrams (that can be printed out for coloring) and basic information about anatomy, diet and more. The Biome-Habitats homepage also contains a simple chart listing differences between biomes including elements such as amount of water, temperature range, and soil quality. (Note: While the site asks for a $20 / year donation, it is free to use and requires no registration or fee).
Factors influencing models of end-of-life care in nursing homes: results of a survey of nursing home administrators.
Approximately 20% of deaths in the United States occur in nursing homes. Dying nursing home residents have unique care needs, which historically have been inadequately addressed. The goal of this study was to determine what factors influence nursing home administrators' choice of model for end-of-life care in their facilities. Thirty nursing home administrators in the Denver, Colorado, metropolitan area were interviewed. The interview used open-ended questions about: facilities' end-of-life care programming and factors that influenced which model was used; scalar questions measuring administrators' attitudes about aspects of end-of-life care; and questions that assessed key demographic characteristics of participants. Twenty-nine of the 30 facilities included in this study reported contracting with hospice. Five were also in the process of creating in-house palliative care teams, and an additional five were negotiating with hospice agencies to dedicate beds for use as hospice units. For profit status, larger facility size, and shorter duration of administrator tenure were found to be associated with greater likelihood of considering implementation of a facility-based end-of-life care model. When asked about obstacles to providing quality end-of-life care, the majority of participants (n = 16) cited an educational deficit among physicians, staff, or the public as the most significant, while an additional seven cited staff shortages and turnover. These results suggest at least two potential avenues for change to improve end-of-life care in nursing homes: (1) educational efforts on the topics of end-of-life and palliative care among both practitioners, residents, and their families, and (2) creating incentives to improve staff recruitment and retention. PMID:15588358
Rice, Kristen N; Coleman, Eric A; Fish, Ron; Levy, Cari; Kutner, Jean S
ERIC Educational Resources Information Center
The materials in this educational packet are designed for use with students in grades 4 through 7. They consist of an overview, teaching guides and student data sheets for three activities, and a poster. The overview discusses the city as an ecosystem, changing urban habitats, urban wildlife habitats, values of wildlife, habitat management, and
Fish and Wildlife Service (Dept. of Interior), Washington, DC.
Does Human-Induced Habitat Modification Influence the Impact of Introduced Species? A Case Study on Cavity-Nesting by the Introduced Common Myna ( Acridotheres tristis) and Two Australian Native Parrots
NASA Astrophysics Data System (ADS)
Introduced species pose a major threat to biodiversity across the globe. Understanding the impact of introduced species is critical for effective management. Many species around the world are reliant on tree cavities, and competition for these resources can be intense: threatening the survival of native species. Through the establishment of 225 nest boxes, we examined the relationship between tree density and the abundance and nesting success of three bird species in Canberra, Australia. The common myna ( Acridotheres tristis) is an introduced species in Australia, and the crimson rosella ( Platycercus elegans) and eastern rosella ( Platycercus eximius) are native species. We then investigated the impact of common myna nest box occupation on crimson rosella and eastern rosella abundance. Tree density significantly influenced the abundance and cavity-nesting of all three species. Common myna abundance (birds per square kilometer) was greatest at low tree density sites (101.9 Ý 22.4) and declined at medium (45.4 Ý 10.1) and high (9.7 Ý 3.6) tree density sites. The opposite pattern was observed for the crimson rosella, with greater abundance (birds per square kilometer) at high tree density sites (83.9 Ý 9.3), declining over medium (61.6 Ý 6.4) and low (31.4 Ý 3.9) tree density sites. The eastern rosella was more abundant at medium tree density sites (48.6 Ý 8.0 birds per square kilometer). Despite the strong influence of tree density, we found a significant negative relationship between common myna nest box occupancy and the abundance of the crimson rosella ( F 1,13 = 7.548, P = 0.017) and eastern rosella ( F 1,13 = 9.672, P < 0.001) at some sites. We also observed a slight increase in rosella nesting interruptions by the common myna at lower tree densities (high: 1.3 % Ý 1.3, medium: 6.6 % Ý 2.2, low: 12.7 % Ý 6.2), although this increase was not statistically significant ( F 2,40 = 2.435, P = 0.100). Our study provides the strongest evidence to date for the negative impact of the common myna on native bird abundance through cavity-nesting competition. However, due to the strong influence of habitat on species abundance and nesting, it is essential to investigate the impacts of introduced species in conjunction with habitat variation. We also suggest one component of introduced species management could include habitat restoration to reduce habitat suitability for introduced species.
Grarock, Kate; Lindenmayer, David B.; Wood, Jeffrey T.; Tidemann, Christopher R.
The influence of floodplain habitat on the quantity and quality of riverine phytoplankton carbon produced during the flood season in San Francisco Estuary
Primary productivity, community respiration, chlorophyll a concentration, phytoplankton species composition, and environmental factors were compared in the Yolo Bypass floodplain and\\u000a adjacent Sacramento River in order to determine if passage of Sacramento River through floodplain habitat enhanced the quantity\\u000a and quality of phytoplankton carbon available to the aquatic food web and how primary productivity and phytoplankton species\\u000a composition in these
Peggy W. Lehman; Ted Sommer; Linda Rivard
The ability of worklife balance policies to influence key social\\/organisational issues
There is increasing evidence that worklife imbalance has a direct impact on societal issues, such as delayed parenting, declining fertility rates, ageing populations, and decreasing labour supply. It is documented that worklife balance policies are beneficial for individuals, their families, organisations, and society. However, other evidence demonstrates that the associated benefits are not always realised and worklife balance policies can
Paula Brough; Jackie Holt; Rosie Bauld; Amanda Biggs; Claire Ryan
The ability of work--life balance policies to influence key social\\/organisational issues
There is increasing evidence that work-life imbalance has a direct impact on societal issues, such as delayed parenting, declining fertility rates, ageing populations, and decreasing labour supply. It is documented that work-life balance policies are beneficial for individuals, their families, organisations, and society. However, other evidence demonstrates that the associated benefits are not always realised and work-life balance policies can
Paula Brough; Jackie Holt; Rosie Bauld; Amanda Biggs; Claire Ryan
Anopheline Larval Habitats Seasonality and Species Distribution: A Prerequisite for Effective Targeted Larval Habitats Control Programmes
Background Larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. Understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. This study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western Kenya. Methods and Findings A total of 51 aquatic habitats positive for anopheline larvae were surveyed and visited once a week for a period of 85 weeks in succession. Habitats were selected and identified. Mosquito larval species, physico-chemical parameters, habitat size, grass cover, crop cycle and distance to nearest house were recorded. Polymerase chain reaction revealed that An. gambiae s.l was the most dominant vector species comprised of An.gambiae s.s (77.60%) and An.arabiensis (18.34%), the remaining 4.06% had no amplification by polymerase chain reaction. Physico-chemical parameters and habitat size significantly influenced abundance of An. gambiae s.s (P?=?0.024) and An. arabiensis (P?=?0.002) larvae. Further, larval species abundance was influenced by crop cycle (P?0.001), grass cover (P?0.001), while distance to nearest houses significantly influenced the abundance of mosquito species larvae (r?=?0.920;P?0.001). The number of predator species influenced mosquito larval abundance in different habitat types. Crop weeding significantly influenced with the abundance of An.gambiae s.l (P?0.001) when preceded with fertilizer application. Significantly higher anopheline larval abundance was recorded in habitats in pasture compared to farmland (P?=?0.002). When habitat stability and habitat types were considered, hoof print were the most productive followed by disused goldmines. Conclusion These findings suggest that implementation of effective larval control programme should be targeted with larval habitats succession information when larval habitats are fewer and manageable. Crop cycles and distance from habitats to household should be considered as effective information in planning larval control.
Kweka, Eliningaya J.; Zhou, Guofa; Munga, Stephen; Lee, Ming-Chieh; Atieli, Harrysone E.; Nyindo, Mramba; Githeko, Andrew K.; Yan, Guiyun
The Influence of Early-Life Events on Human Capital, Health Status, and Labor Market Outcomes Over the Life Course().
Using national data from the U.S., we find that poor health at birth and limited parental resources (including low income, lack of health insurance, and unwanted pregnancy) interfere with cognitive development and health capital in childhood, reduce educational attainment, and lead to worse labor market and health outcomes in adulthood. These effects are substantial and robust to the inclusion of sibling fixed effects and an extensive set of controls. The results reveal that low birth weight ages people in their 30s and 40s by 12 years, increases the probability of dropping out of high school by one-third, lowers labor force participation by 5 percentage points, and reduces labor market earnings by roughly 15 percent. While poor birth outcomes reduce human capital accumulation, they explain only 10 percent of the total effect of low birth weight on labor market earnings. Taken together, the evidence is consistent with a negative reinforcing intergenerational transmission of disadvantage within the family; parental economic status influences birth outcomes, birth outcomes have long reaching effects on health and economic status in adulthood, which in turn leads to poor birth outcomes for one's own children. PMID:23412970
Johnson, Rucker C; Schoeni, Robert F
Life Satisfaction in Early Adolescence: Personal, Neighborhood, School, Family, and Peer Influences
ERIC Educational Resources Information Center
Drawing from an ecological assets framework as well as research and theory on positive youth development, this study examined the relationship of early adolescents' satisfaction with life to trait optimism and assets representing the social contexts in which early adolescents spend most of their time. Self-reports of satisfaction with life,
Oberle, Eva; Schonert-Reichl, Kimberly A.; Zumbo, Bruno D.
The influence of raw material characteristics on the storage life of fresh-cut butterhead lettuce
The physiological characteristics of 5 butterhead lettuce cultivars (Lactuca sativa L.) were investigated using etiolated leaves. Their storage life under modified and controlled atmospheres was assessed. When prepacked butterhead lettuce was maintained under a low oxygen atmosphere to prevent enzymatic browning, high CO2 content was the main factor increasing the rate of decay. Shelf life was negatively correlated with respiration
Patrick Varoquaux; JÕr¶me Mazollier; Guy Albagnac
Influence of Melatonin on Quality of Life in Patients with Chronic Fatigue and Late Melatonin Onset
, ABSTRACT. Medical Outcome Study Short Fonn-36 (MOS SF-36) qualities of life scores were studied in 38 chronic fatigue patients with late melatonin onset before and after treatment with melatonin. Before start of the treatment, quality of life was assessed twice. Pre-treatment scores were compared with each other and with the scores of 43 patients with Delayed Sleep Phase Syndrome
M. G. Smits; R. van Rooy; J. E. Nagtegaal
The Influence of Parent and Peer Attachments on Life Satisfaction in Middle Childhood and Early Adolescence
ERIC Educational Resources Information Center
Satisfaction in different life domains was examined with respect to parent and peer attachment relationships in middle childhood and early adolescence. Three hundred and three students, evenly distributed across sex and grade (fourth, sixth, and eighth) were administered "People in My Life," a measure of attachment relationships, and the
Nickerson, Amanda B.; Nagle, Richard J.
Life history influences how fire affects genetic diversity in two lizard species.
'Fire mosaics' are often maintained in landscapes to promote successional diversity in vegetation with little understanding of how this will affect ecological processes in animal populations such as dispersal, social organization and re-establishment. To investigate these processes, we conducted a replicated, spatiotemporal landscape genetics study of two Australian woodland lizard species [Amphibolurus norrisi (Agamidae) and Ctenotus atlas (Scincidae)]. Agamids have a more complex social and territory structure than skinks, so fire might have a greater impact on their population structure and thus genetic diversity. Genetic diversity increased with time since fire in C. atlas and decreased with time since fire in A. norrisi. For C. atlas, this might reflect its increasing population size after fire, but we could not detect increased gene flow that would reduce the loss of genetic diversity through genetic drift. Using landscape resistance analyses, we found no evidence that postfire habitat succession or topography affected gene flow in either species and we were unable to distinguish between survival and immigration as modes of postfire re-establishment. In A. norrisi, we detected female-biased dispersal, likely reflecting its territorial social structure and polygynous mating system. The increased genetic diversity in A. norrisi in recently burnt habitat might reflect a temporary disruption of its territoriality and increased male dispersal, a hypothesis that was supported with a simulation experiment. Our results suggest that the effects of disturbance on genetic diversity will be stronger for species with territorial social organization. PMID:24750427
Smith, Annabel L; Bull, C Michael; Gardner, Michael G; Driscoll, Don A
Life History Variation in Invading Applesnails (Pomacea canaliculata) May Pose Ecological Threats to Wetlands
In native habitats, channeled applesnails (Pomacea canaliculata) graze periphyton. However, casual observations from introduced populations suggest these invaders show variation in feeding ecology, predator response and life history strategies. Attempts to predict this consumer influence on ecosystem function suffer from a lack of basic data. We tested how salinity affected snail mortality. Both adults and hatchlings tolerated salinity levels up
R. K. Marfurt; B. B. Boland; R. L. Burks
Influence of life history strategies on sensitivity, population growth and response to climate for sympatric alpine birds
Background The life history strategy of a species can influence how populations of that species respond to environmental variation. In this study, we used a matrix modeling approach to examine how life history differences among sympatric rock and white-tailed ptarmigan affect the influence of demographic rates on population growth (?) and the potential response to a changing climate. Rock ptarmigan have a slower life history strategy than white-tailed ptarmigan in the study region with lower annual reproductive effort but higher adult survival. Results Based on data from a 5-year field study, deterministic estimates of ? indicated that populations were stable for rock ptarmigan (??=?1.01), but declining for white-tailed ptarmigan (??=?0.96). The demographic rates with the highest elasticity for rock ptarmigan were the survival of after-second year females, followed by juvenile survival and success of the first nest. For white-tailed ptarmigan, juvenile survival had the highest elasticity followed by success of the first nest and survival of second-year females. Incorporating stochasticity into the demographic rates led to a 2 and 4% drop in ? for rock and white-tailed ptarmigan respectively. Using data from the first three years we also found that population growth rates of both species were depressed following an increased frequency of severe years, but less so for rock ptarmigan which showed greater resilience under these conditions. Conclusions Our results provide evidence that populations of closely related species can vary in their response to environmental change as a consequence of life history differences. Rock ptarmigan, with a slower life history, are more responsive to demographic rates that influence survival and older life stages but this response is tempered by the extent of variability in each of the rates. Thus, predictions need to consider both aspects in modeling population response to a varying climate. Juvenile survival was a highly influential rate for both species, but the period from independence to first breeding is a poorly understood stage for many bird species. Additional study on juvenile survival, the influence of density dependence and the effects of predators as the mechanism driving survival-reproduction tradeoffs are all areas requiring further study.
Clinal variation in seed traits influencing life cycle timing in Arabidopsis thaliana.
Early life-history transitions are crucial determinants of lifetime survival and fecundity. Adaptive evolution in early life-history traits involves a complex interplay between the developing plant and its current and future environments. We examined the plant's earliest life-history traits, dissecting an integrated suite of pregermination processes: primary dormancy, thermal induction of secondary dormancy, and seasonal germination response. We examined genetic variation in the three processes, genetic correlations among the processes, and the scaling of germination phenology with the source populations' climates. A spring annual life history was associated with genetic propensities toward both strong primary dormancy and heat-induced secondary dormancy, alone or in combination. Lineages with similar proportions of winter and spring annual life history have both weak primary dormancy and weak thermal dormancy induction. A genetic bias to adopt a spring annual strategy, mediated by rapid loss of primary dormancy and high thermal dormancy induction, is associated with a climatic gradient characterized by increasing temperature in summer and rainfall in winter. This study highlights the importance of considering combinations of multiple genetically based traits along a climatic gradient as adaptive strategies differentiating annual plant life-history strategies. Despite the genetic-climatic cline, there is polymorphism for life-history strategies within populations, classically interpreted as bet hedging in an unpredictable world. PMID:23106707
Montesinos-Navarro, Alicia; Picµ, F Xavier; Tonsor, Stephen J
Geomorphological, trophic and human influences on the bamboo coral Isidella elongata assemblages in the deep Mediterranean: To what extent does Isidella form habitat for fish and invertebrates?
NASA Astrophysics Data System (ADS)
We analyzed what are the best ecological conditions for megafauna associated with the bamboo coral Isidella elongata based on the geomorphological, physical and trophic information taken in 3 stations (St1, St2, St3) off the southern Catalonian coasts at 620 m depth in June 2011. Results were compared with assemblage compositions recorded in past cruises (May 1992, 1994) at the same 3 stations. St1 was in a fishing ground exploited since the 1940s over a relatively wide slope at ca. 22 km from the nearest canyon head; St2 and St3 were on a narrower slope closer to canyon heads and to the Ebro river mouth than St1. I. elongata had formed (to May 1994, at least) a dense coral forest at St2-St3 (to ca. 255 colonies/ha at St3), and some isolated colonies (to ca. 0.9 colonies/ha) were still collected in 2011. Fish and invertebrate communities significantly differed between St1 and St2/St3, with two macrourid fishes (Trachrhynchus trachyrhynchus and Nezumia aequalis) and two decapods (Plesionika martia and Plesionika acanthonotus) more abundant at St2/St3. The following ecological indicators imply better food conditions for megafauna at St2-St3 and for I. elongata itself: (i) greater density of zooplankton (copepods, euphausiids, and others) as potential prey for planktivores (including I. elongata); (ii) greater biomass and mean weight of epifaunal and infaunal deposit feeders; (iii) higher feeding intensity, F, at St3 for benthos feeders (Phycis blennoides, N. aequalis and Aristeus antennatus). Also, at St2-St3 we found higher near-bottom turbidity (indicating particle resuspension: food for suspension feeders) and finer and more reduced (Eh) sediments. The results let us suggest that corals and accompanying fauna preferently found optimal ecological conditions in the same habitat, while habitat-forming capacity by I. elongata seemed weak to generate these conditions. Coral forests may enhance detritus accumulations around them, improving habitat conditions for benthos feeders (e.g. macrourid fish). At St3 our side-scan sonar recorded three types of tracks produced by trawler doors, which match with three identified vessels occasionally operating in the area. After this low fishing activity off the Ebro Delta since the mid-1990s, almost all colonies of I. elongata has been removed. However, this impact has hardly altered fish and invertebrate composition without any significant loss of diversity, pointing also toward a rather low capacity of I. elongata facies in forming habitat for megafauna on muddy bottoms of the Mediterranean slope.
Cartes, J. E.; LoIacono, C.; Mamouridis, V.; Lµpez-PÕrez, C.; RodrÚguez, P.
Dispersal and habitat cuing of Eurasian red squirrels in fragmented habitats
Animal dispersal and subsequent settlement is a key process in the life history of many organisms, when individuals use demographic\\u000a and environmental cues to target post-dispersal habitats where fitness will be highest. To investigate the hypothesis that\\u000a environmental disturbance (habitat fragmentation) may alter these cues, we compared dispersal patterns of 60 red squirrels\\u000a (Sciurus vulgaris) in three study sites that
Lucas Armand Wauters; Goedele Verbeylen; Damiano Preatoni; Adriano Martinoli; Erik Matthysen
Health-related quality of life and influencing factors among rural left-behind wives in Liuyang, China
Background In China, the number of left-behind wives in rural areas has reached 47 million. Left-behind wives might have more psychological stress and lower life quality. This study was to examine the health-related quality of life and influencing social and cognitive factors in a sample of left-behind wives in rural areas of China. Methods The demographic data questionnaire, the Short Form 36 Health Survey Scale, Center for Epidemiological Studies Depression Scale, Perceived Social Support Scale, Simplified Coping Style Questionnaire, and Perceived Stress Scale were completed by a sample of 1,893 left-behind wives and 969 non-left-behind wives. Results Left-behind wives had lower scores on physical component summary (PCS), mental component summary (MCS) , and all the eight subscales of the SF-36 than non-left-behind wives (P?0.05), especially on the role limitations due to emotional problems (RE) and on MCS. Compared to non-left-behind wives, left-behind wives scored higher in depression, stress, and passive coping styles, and scored significantly lower in social support and active coping styles. Logistic regression analysis showed that the status of being left behind, age, education years, monthly income, employment, physical health status, active coping styles, and depression were influencing factors on the PCS of rural women, whereas the status of being left behind, monthly income, physical health status, sense of marriage security, stress, social support, passive coping styles, and depression were influencing factors on the MCS of rural women. Conclusions Left-behind wives scored lower on health-related quality of life than non-left-behind wives. Low health-related quality of life was associated with left behind status, older age, less education, low monthly income, unemployment, bad physical health status, passive coping styles, low social support, high level of stress, and high depression.
Setting priorities for conserving and rehabilitating Detroit River habitats
This chapter discusses habitat for wild animals and plants in the Detroit River. Such habitat has been defined as places in the river where physical, chemical, and biological factors, including soil and water quality sustain all life stages of fish and wildlife, including their reproduction.
Manny, Bruce A.
AVIAN COMqUNITIES: APPROACHES TO DESCRIBING THEIR HABITAT ASSOCIATIONS
Four approaches are presented which enable wildlife managers to consider many avian species simultaneously in management objectives. The northeastern Minnesota avifauna is used to test each approach. Three approaches included the classification of avian species into structural successional stages, life forms, or their sociological associations. The fourth approach, habitat niche, depicts species response to quantitative habitat variables. The background, methods,
Gerald J. Niemi; Lee Pfannmuller
Habitat complexity, brain, and behavior.
More complex brains and behaviors have arisen repeatedly throughout both vertebrate and invertebrate evolution. The challenge is to tease apart the forces underlying such change. In this review, I show how habitat complexity influences both brain and behavior in African cichlid fishes, drawing on examples from primates and birds where appropriate. These species groups share a number of similarities. They exhibit a considerable range of brain to body weight within their group. Often highly visual, the species show a diversity of habitat types, social systems, and cognitive abilities. Phylogenies are well established. In closely-related cichlid fishes from the monophyletic Ectodine clade of Lake Tanganyika, habitat complexity is directly correlated with social variables, including species richness, diversity, and abundance. Total brain size, telencephalic and cerebellar size are positively correlated with habitat complexity. Visual acuity and spatial memory are also enhanced in cichlids living in more complex environments. I speculate that species-specific neural effects of environmental complexity could be the consequence of the corresponding social changes. However, environmental and social forces affect brains differently. Environmental forces exert a broader effect on brain structures than social ones, suggesting either allometric expansion of the brain structures in concert with brain size and/or co-evolution of these structures. To advance our understanding of the mechanism by which habitat complexity affects brain and behavior will require the use of closely-related species, quantification of complexity, hypothesis testing restricting analysis to a single variable and path analyses to explore the order of importance of such variables. We will also need new experimental paradigms exploring the cognitive and survival value of brain and brain structure changes both in the laboratory and in the wild. PMID:18836258
Shumway, Caroly A
The influence of environmental conditions on early life stages of flounder (Platichthys flesus) in the central Baltic Sea
NASA Astrophysics Data System (ADS)
Flounder (Platichthys flesus) is a temperate marine fish that is well adapted to the brackish waters of the Baltic Sea. There are two sympatric flounder populations in the Baltic Sea, pelagic and demersal spawners, which differ in their spawning habitat and egg characteristics. In the present study, pelagic spawning flounder of the central Baltic Sea was studied. We examined whether variations in hydrological regime can explain fluctuations in flounder early life stages that have occurred over the past 30 years (1970-2005). Using generalized additive modeling to explain the abundance of flounder eggs and larvae in a Latvian ichthyoplankton dataset, we evaluate the hypothesis that the available reproductive volume, defined as the water column with dissolved oxygen larger than 1 ml/l and salinity between 10.6 and 12 PSU, affects the survival of flounder ichthyoplankton and determines recruitment success. Both reproductive volume and spawning stock biomass were significant factors determining flounder ichthyoplankton abundance. Different measures of water temperature did not contribute significantly to the variability of eggs or larvae. However, recruitment did not correlate to the supply of larvae. The findings presented in this study on the relationship between flounder reproduction, spawning stock biomass and reproductive volume, as well as the lack of correlation to recruitment, are valuable for the understanding of flounder ecology in the Baltic Sea, and for developing the management of the species.
Ustups, Didzis; M■ller-Karulis, Bðrbel; Bergstrom, Ulf; Makarchouk, Andrej; Sics, Ivo
Evolutionary consequences of habitat loss for Pacific anadromous salmonids
Large portions of anadromous salmonid habitat in the western United States has been lost because of dams and other blockages. This loss has the potential to affect salmonid evolution through natural selection if the loss is biased, affecting certain types of habitat differentially, and if phenotypic traits correlated with those habitat types are heritable. Habitat loss can also affect salmonid evolution indirectly, by reducing genetic variation and changing its distribution within and among populations. In this paper, we compare the characteristics of lost habitats with currently accessible habitats and review the heritability of traits which show correlations with habitat/environmental gradients. We find that although there is some regional variation, inaccessible habitats tend to be higher in elevation, wetter and both warmer in the summer and colder in the winter than habitats currently available to anadromous salmonids. We present several case studies that demonstrate either a change in phenotypic or life history expression or an apparent reduction in genetic variation associated with habitat blockages. These results suggest that loss of habitat will alter evolutionary trajectories in salmonid populations and Evolutionarily Significant Units. Changes in both selective regime and standing genetic diversity might affect the ability of these taxa to respond to subsequent environmental perturbations. Both natural and anthropogenic and should be considered seriously in developing management and conservation strategies.
McClure, Michelle M; Carlson, Stephanie M; Beechie, Timothy J; Pess, George R; Jorgensen, Jeffrey C; Sogard, Susan M; Sultan, Sonia E; Holzer, Damon M; Travis, Joseph; Sanderson, Beth L; Power, Mary E; Carmichael, Richard W
Assessment of health-related quality of life and influencing factors using QOLIE-31 in Japanese patients with epilepsy.
The aim of epilepsy treatment is not only to eliminate seizures, but also to improve health-related quality of life (HRQOL). We conducted a postal self-administered survey of HRQOL for Japanese patients using the Quality of Life in Epilepsy inventory (QOLIE-31), Version 1.0, and analyzed factors influencing their quality of life (QOL). Data from 599 analyzable patients were evaluated and a number of factors influencing QOL were identified, including severity and frequency of seizures, seizure control, type of epilepsy, contributing events such as injuries and falls during seizures, number of antiepileptic drugs, employment status, and surgical outcome. These findings suggest that comprehensive management of the patient should be emphasized. Consideration of all the results led to classification of these factors as one of two types: "all or nothing" and "linear." With respect to "all or nothing" factors (e.g. "daytime remarkable seizures"), patients may not be able to improve their QOL unless these factors can be completely controlled. Comparison of each score on the QOLIE-31 subscales with published data revealed that the scores for the subscale Medication Effects were markedly low. PMID:20646964
Kubota, Hidemoto; Awaya, Yutaka
Population viability impacts of habitat additions and subtractions: A simulation experiment with endangered kangaroo rats
Species viability is influenced by the quality, quantity and configuration of habitat. For species at risk, a principal challenge is to identify landscape configurations that, if realized, would improve a population?s viability or restoration potential. Critical habitat patche...
Living Things: Habitats & Ecosystems
NSDL National Science Digital Library
Text and photographs regarding habitats, populations and communities, biomes, niches and ecosystems in general with numerous links to lessons, activities, and organizations on specific subtopics in ecology.
Critter Crossings: Linking Habitats and Reducing Roadkill.
National Technical Information Service (NTIS)
Who can benefit from this web site: Everyone interested in protecting wildlife along highways and the habitats that sustain them. What are the issues: Roads are the arteries of life. They get us where we want to go. They also stop animals in their tracks ...
G. Finch
Satisfaction vs. Sacrifice: Sports Editors Assess the Influences of Life Issues on Job Satisfaction
A survey (N = 184) and interviews examine issues that influence job satisfaction among newspaper sports editors. The results indicate that perceived organizational support has a strong, positive correlation to job satisfaction, while work-family conflict and role overload have a negative influence. The interviews indicate that sports editors do not receive as much organizational support as the survey suggests. Motivation-hygiene
Scott Reinardy
Influence of clinical, demographic, and socioeconomic variables on quality of life in patients with epilepsy: findings from Georgian study
Objective: To identify the clinical, demographic, and socioeconomic factors that are associated with a poor quality of life in patients with epilepsy in Georgia. Methods: Clinical, demographic, and socioeconomic status data were collected from 115 adult epileptic outpatients being treated in the epilepsy programme at the Sarajishvili Institute of Neurology and Neurosurgery (SINN) in Tbilisi, Georgia. Health Related Quality of Life (HRQL) was measured by the Quality of Life in Epilepsy Inventory (QOLIE-31). Multiple regression analysis was used to determine which variables were associated with QOLIE-31 total and subcomponent scores. Results: Mean age of the patient population was 37.9 (SD 15.8) years; 43.5% were females; 51.8% did not have a partner; 39.1% had some university education; 82.6% were unemployed. Of 115 epileptic patients 83.3% had partial, and 16.7% had generalised seizures. Overall, 32.2% of patients were seizure free, and 28.7% experienced more than 10 seizures over the past year. The variables that most strongly predicted a lower QOLIE-31 total score were a low education level, high seizure frequency, and long duration of epilepsy. The QOLIE-31 all subcomponent scores correlated strongly with seizure frequency. Advanced age was a significant predictor for a low overall quality of life, energy/fatigue, and cognitive scores. Female sex was the factor that significantly predicted a low seizure worry score. Education level strongly correlated with overall quality of life, and cognitive and social functioning scores. Conclusions: Clinical factors such as high seizure frequency and long duration of epilepsy had a significant influence on HRQL. Advanced age, female sex, and a low education level were the demographic factors that correlated strongly with low quality of life scores.
Djibuti, M; Shakarishvili, R
Influence of craniosacral therapy on anxiety, depression and quality of life in patients with fibromyalgia.
Fibromyalgia is considered as a combination of physical, psychological and social disabilities. The causes of pathologic mechanism underlying fibromyalgia are unknown, but fibromyalgia may lead to reduced quality of life. The objective of this study was to analyze the repercussions of craniosacral therapy on depression, anxiety and quality of life in fibromyalgia patients with painful symptoms. An experimental, double-blind longitudinal clinical trial design was undertaken. Eighty-four patients diagnosed with fibromyalgia were randomly assigned to an intervention group (craniosacral therapy) or placebo group (simulated treatment with disconnected ultrasound). The treatment period was 25 weeks. Anxiety, pain, sleep quality, depression and quality of life were determined at baseline and at 10 minutes, 6 months and 1-year post-treatment. State anxiety and trait anxiety, pain, quality of life and Pittsburgh sleep quality index were significantly higher in the intervention versus placebo group after the treatment period and at the 6-month follow-up. However, at the 1-year follow-up, the groups only differed in the Pittsburgh sleep quality index. Approaching fibromyalgia by means of craniosacral therapy contributes to improving anxiety and quality of life levels in these patients. PMID:19729492
MatarÃn-Peþarrocha, Guillermo A; Castro-SÃnchez, Adelaida MarÚa; GarcÚa, Gloria Carballo; Moreno-Lorenzo, Carmen; Carreþo, Tesifµn Parrµn; Zafra, MarÚa Dolores Onieva
Ecological and life-history factors influencing the evolution of maternal antibody allocation: a phylogenetic comparison
Maternally derived yolk antibodies provide neonates with immune protection in early life at negligible cost to mothers. However, developmental effects on the neonate's future immunity are potentially costly and thus could limit yolk antibody deposition. The benefits to neonatal immunity must be balanced against costs, which may depend on neonate vulnerability to pathogens, developmental trajectories and the immunological strategies best suited to a species' pace of life. We measured yolk antibodies and life-history features of 23 species of small Neotropical birds and assessed the evidence for each of several hypotheses for life history and ecological effects on the evolution of yolk antibody levels. Developmental period and yolk antibodies are negatively related, which possibly reflect the importance of humoral immune priming through antigen exposure, and selection to avoid autoimmunity, in species with a slower pace of life. There is also a strong relationship between body size and yolk antibody concentration, suggesting that larger species are architecturally equipped to produce and transfer higher concentrations of antibodies. These results suggest that developmental effects of maternally derived antibodies, such as imprinting effects on B-cell diversity or autoimmune effects, are important and deserve more consideration in future research.
Addison, BriAnne; Klasing, Kirk C.; Robinson, W. Douglas; Austin, Suzanne H.; Ricklefs, Robert E.
End-of-Life Treatment Preferences Among Older Adults: An Assessment of Psychosocial Influences1
We explore the content and correlates of older adults end-of-life treatment preferences in two hypothetical terminal illness scenarios: severe physical pain with no cognitive impairment, and severe cognitive impairment with no physical pain. For each scenario, we assess whether participants would reject life-prolonging treatment, accept treatment, or do not know their preferences. Using data from the 2004 wave of the Wisconsin Longitudinal Study (N = 5,106), we estimate multinomial logistic regression models to evaluate whether treatment preferences are associated with direct experience with end-of-life issues, personal beliefs, health, and sociodemographic characteristics. Persons who have made formal end-of-life preparations, persons with no religious affiliation, mainline Protestants, and persons who are pessimistic about their own life expectancy are more likely to reject treatment in both scenarios. Women and persons who witnessed the painful death of a loved one are more likely to reject treatment in the cognitive impairment scenario only. Consistent with rational choice perspectives, our results suggest that individuals prefer treatments that they perceive to have highly probable desirable consequences for both self and family.
Carr, Deborah; Moorman, Sara M.
The influence of mortality and socioeconomic status on risk and delayed rewards: a life history theory approach.
Why do some people take risks and live for the present, whereas others avoid risks and save for the future? The evolutionary framework of life history theory predicts that preferences for risk and delay in gratification should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced decisions involving risk preference (e.g., $10 for sure vs. 50% chance of $20) and temporal discounting (e.g., $5 now vs. $10 later). The effect of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals who grew up relatively poor, mortality cues led them to value the present and gamble for big immediate rewards. Conversely, for individuals who grew up relatively wealthy, mortality cues led them to value the future and avoid risky gambles. Overall, mortality cues appear to propel individuals toward diverging life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors influence economic decisions and risky behaviors. PMID:21299312
Griskevicius, Vladas; Tybur, Joshua M; Delton, Andrew W; Robertson, Theresa E
The Influence of Mortality and Socioeconomic Status on Risk and Delayed Rewards: A Life History Theory Approach
Why do some people take risks and live for the present, whereas others avoid risks and save for the future? The evolutionary framework of life history theory predicts that preferences for risk and delay in gratification should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced decisions involving risk preference (e.g., $10 for sure vs. 50% chance of $20) and temporal discounting (e.g., $5 now vs. $10 later). The effect of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals who grew up relatively poor, mortality cues led them to value the present and gamble for big immediate rewards. Conversely, for individuals who grew up relatively wealthy, mortality cues led them to value the future and avoid risky gambles. Overall, mortality cues appear to propel individuals toward diverging life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors influence economic decisions and risky behaviors.
Griskevicius, Vladas; Tybur, Joshua M.; Delton, Andrew W.; Robertson, Theresa E.
Snow as a habitat for microorganisms
NASA Technical Reports Server (NTRS)
There are three major habitats involving ice and snow, and the microorganisms studied from these habitats are most eukaryotic. Sea ice is inhabited by algae called diatoms, glacial ice has sparse populations of green algai cal desmids, and the temporary and permanent snows in mountainous regions and high latitudes are inhabited mostly by green algal flagellates. The life cycle of green algal flagellates is summarized by discussing the effects of light, temperature, nutrients, and snow melts. Specific examples of optimal conditions and environmental effects for various snow algae are given. It is not likely that the eukaryotic snow algae presented are candidated for life on the planet Mars. Evolutionally, eukaryotic cells as know on Earth may not have had the opportunity to develop on Mars (if life evolved at all on Mars) since eukaryotes did not appear on Earth until almost two billion years after the first prokaryotic organisms. However, the snow/ice ecosystems on Earth present themselves as extreme habitats were there is evidence of prokaryotic life (eubacteria and cyanbacteria) of which literally nothing is known. Any future surveillances of extant and/or extinct life on Mars should include probes (if not landing sites) to investigate sites of concentrations of ice water. The possibility of signs of life in Martian polar regions should not be overlooked.
Hoham, Ronald W.
The Influence of Cognitive Impairment, Special Care Unit Placement, and Nursing Facility Characteristics on Resident Quality of Life
Objectives We examined the (a) influence of nursing facility characteristics on resident quality of life and (b) the impact of cognitive impairment and residence on a dementia special care unit(SCU) on QOL after controlling for resident and facility characteristics. Method Multilevel models (resident and facility) were estimated for residents with and without cognitive impairment on conventional units and dementia SCU. Data came from the 2007 Minnesota Nursing Home Resident Quality of Life and Consumer Satisfaction Survey (N = 13,983). Results Level of resident CI was negatively related to QOL, although residing on a dementia SCU was positively related to QOL. Certified Nursing Assistant and activity personnel hours per resident day had a positive relationship with resident QOL. Discussion Our results highlight the need to ensure adequate levels of paraprofessional direct care staff and the availability of dementia-focused (SCU)s despite current constraints on long-term care funding.
Abrahamson, Kathleen; Lewis, Teresa; Perkins, Anthony; Clark, Daniel; Nazir, Arif; Arling, Greg
Landscape-stream interactions and habitat conservation for amphibians.
Semiaquatic organisms depend on the features of both water bodies and landscapes; the interplay between terrestrial and aquatic systems might influence the semiaquatic communities, determining the scale at which management would be more effective. However, the consequences of such interplay are not frequently quantified, particularly at the community level. We analyzed the distribution of amphibians to evaluate whether the influence of landscape features on freshwater ecosystems can have indirect consequences at both the species and community level. We surveyed 74 streams in northern Italy to obtain data on breeding amphibians, water, and microhabitat features; we also measured features of surrounding landscapes. We used an information-theoretic approach and structural equation models to compare hypotheses on causal relationships between species distribution and variables measured at multiple levels. We also used a constrained redundancy analyses to evaluate causal relationships between multivariate descriptors of habitat features and community composition. Distribution of Salamandra salamandra was related to landscape, hydrological, and water characteristics: salamanders were more frequent in permanent streams with low phosphate concentration within natural landscapes. Water characteristics were dependent on landscape: streams in natural landscapes had less phosphates. Landscape influenced the salamander both directly and indirectly through its influence on phosphates. Community structure was determined by both landscape and water characteristics. Several species were associated with natural landscapes, and with particular water characteristics. Landscape explained a significant proportion of variability of water characteristics; therefore it probably had indirect effects on community. Upland environments play key roles for amphibians, for example, as the habitat of adults, but upland environments also have indirect effects on the aquatic life stages, mediated through their influence on water characteristics. Synergistic effects can magnify the negative consequences of landscape alteration on amphibians; landscape management can be particularly effective, as it can also improve wetland features. PMID:21774429
Ficetola, Gentile Francesco; Marziali, Laura; Rossaro, Bruno; De Bernardi, Fiorenza; Padoa-Schioppa, Emilio
Influence of Religiosity on the Quality of Life and on Pain Intensity in Chronic Pancreatitis Patients After Neurolytic Celiac Plexus Block: Case-Controlled Study
The quality of life in patients with chronic pancreatitis (CP) is reduced due to their suffering of high levels of pain. It\\u000a has been presented that quality of life can also be linked to religiosity and\\/or spirituality. The aim of this study is to\\u000a assess the influence of religious practices on the quality of life and on the subjective level
Andrzej Basi?ski; Tomasz Stefaniak; Magdalena Stadnyk; Arfan Sheikh; Ad J. J. M. Vingerhoets
Influence of Solid-State Diffusion during Equilibration on Microstructure and Fatigue Life of Superalloy Wide-Gap Brazements
NASA Astrophysics Data System (ADS)
The influence of solid-state diffusion-controlled solute-loss into additive powder particles (APPs), as determined by particles size, during the equilibration stage of wide-gap brazing, on microstructure and fatigue behavior of a brazed aerospace superalloy was studied. The results, which experimentally confirm previously reported numerical model simulation results, show that, in order to avoid degradation of fatigue life of wide-gap brazement, adequate solute-loss into the APPs, which is necessary to prevent their complete melting, but has not been generally considered, is imperative.
Osoba, L. O.; Ojo, O. A.
The influence of temperature on the cycle life performance of rechargeable Li-TiS2 cells
NASA Technical Reports Server (NTRS)
The authors report studies on the influence of low temperature on the properties and cycling performance of six selected electrolytes. The electrolytes investigated were 2-MeTHF, EC/2-MeTHF, THF, THF/2-MeTHF, EC/THF, and EC/THF/2-MeTHF. All the electrolytes contained 1.5M LiAsF6. Open circuit stand tests indicated that organic electrolytes exhibited improved stability towards lithium at 10 C. However, cycling of the cells at 10 C did not result in improved cycle life performance.
Shen, D. H.; Subbarao, S.; Huang, C.-K.; Deligiannis, F.; Halpert, G.
Influence of recycling rate increase of aseptic carton for long-life milk on GWP reduction
Tetra Pak, through intensive cooperation with its supply chain, increased the post-consumer recycling rate of the aseptic packaging for long-life milk in the last 10 years. In continuation of a previous study that presented a superior overall performance in terms of reduction of the consumption of natural resources, air emissions and most of the water emissions, the objective of the
Anna Lºcia Mourad; Eloisa E. C. Garcia; Gustavo Braz Vilela; Fernando Von Zuben
Proportionate Responses to Life Events Influence Clinicians' Judgments of Psychological Abnormality
ERIC Educational Resources Information Center
Psychological abnormality is a fundamental concept in the "Diagnostic and Statistical Manual of Mental Disorders" ("DSM-IV-TR"; American Psychiatric Association, 2000) and in all clinical evaluations. How do practicing clinical psychologists use the context of life events to judge the abnormality of a person's current behaviors? The appropriate
Kim, Nancy S.; Paulus, Daniel J.; Gonzalez, Jeffrey S.; Khalife, Danielle
The Influence of Subjective Life Expectancy on Retirement Transition and Planning: A Longitudinal Study
ERIC Educational Resources Information Center
This study examines the construct of subjective life expectancy (SLE), or the estimation of one's probable age of death. Drawing on the tenets of socioemotional selectivity theory (Carstensen, Isaacowitz, & Charles, 1999), we propose that SLE provides individuals with their own unique mental model of remaining time that is likely to affect their
Griffin, Barbara; Hesketh, Beryl; Loh, Vanessa
Habitat specialization through germination cueing: a comparative study of herbs from forests and open habitats
Background and Aims This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently accompanied by specialization in their regeneration niche; and (2) species are thereby adapted to utilize different windows of opportunity in time (season) and space (habitat). Methods Seed germination response to temperature, light and stratification was tested for 17 congeneric pairs, each consisting of one forest species and one open-habitat species. A factorial design was used with temperature levels and diurnal temperature variation (10 ¯C constant, 155 ¯C fluctuating, 20 ¯C constant, 2515 ¯C fluctuating), and two light levels (light and darkness) and a cold stratification treatment. The congeneric species pair design took phylogenetic dependence into account. Key Results Species from open habitats germinated better at high temperatures, whereas forest species performed equally well at low and high temperatures. Forest species tended to germinate only after a period of cold stratification that could break dormancy, while species from open habitats generally germinated without cold stratification. The empirically derived germination strategies correspond quite well with establishment opportunities for forest and open-habitat plant species in nature. Conclusions Annual changes in temperature and light regime in temperate forest delimit windows of opportunity for germination and establishment. Germination strategies of forest plants are adaptations to utilize such narrow windows in time. Conversely, lack of fit between germination ecology and environment may explain why species of open habitats generally fail to establish in forests. Germination strategy should be considered an important mechanism for habitat specialization in temperate herbs to forest habitats. The findings strongly suggest that phases in the plant life cycle other than the established phase should be considered important in adaptive specialization.
ten Brink, Dirk-Jan; Hendriksma, Harmen Pieter; Bruun, Hans Henrik
ERIC Educational Resources Information Center
The Habitat Project is a multiday, differentiated, interdisciplinary environmental science lesson that incorporates skill-building and motivational strategies to internalize ecosystem vocabulary. Middle school students research an animal, display its physical characteristics on a poster, build a three-dimensional habitat and present their work
Hein, Annamae J.
Schoolyard Habitat Project Guide.
ERIC Educational Resources Information Center
This project aims to provide basic steps for students to restore and create wildlife habitats on school grounds. Four chapters are included in this guide, and each chapter is divided into teacher and student sections. Chapter 1 provides necessary information for starting a habitat project. Chapters 2, 3, and 4 discuss the details for the Forest
Mason, Rich
NSDL National Science Digital Library
This resource describes the rocky intertidal habitats of the Monterey Bay National Marine Sanctuary and their biological diversity, distribution patterns, temporal changes, links to other habitats and assemblages, and management issues. Supporting materials include photos, tables, figures, and in-text definitions.
Do major life events influence physical activity among older adults: the Longitudinal Aging Study Amsterdam
Background Major life events are associated with a change in daily routine and could thus also affect habitual levels of physical activity. Major life events remain largely unexplored as determinants of older adults participation in physical activity and sports. This study focused on two major life events, widowhood and retirement, and asked whether these major life events were associated with moderate to vigorous physical activity (MVPA) and sports participation. Methods Data from the first (199293) and second (199596) wave of the Longitudinal Aging Study Amsterdam (LASA), a prospective cohort study among Dutch adults aged 55 and older, were used. Change in marital status and employment status between baseline and follow-up was assessed by self-report. Time spent in MVPA (min/d) and sports participation (yes/no) was calculated based on the LASA Physical Activity Questionnaire. The association of retirement and widowhood with MVPA and sports participation was assessed in separate multivariate linear and logistic regression analyses, respectively. Results Widowhood - N=136 versus 1324 stable married- was not associated with MVPA (B= 3.5 [95%CI:-57.9;64.9]) or sports participation (OR= 0.8 [95%CI:0.5;1.3]). Retired participants (N= 65) significantly increased their time spent in MVPA (B= 32.5 [95%CI:17.8;47.1]) compared to participants who continued to be employed (N= 121), but not their sports participation. Age was a significant effect modifier (B= 7.5 [90%CI:-1.1;13.8]), indicating a greater increase in MVPA in older retirees. Discussion Our results suggest that the associations found varied by the two major life events under investigation. MVPA increased after retirement, but no association with widowhood was seen.
Detroit River habitat inventory
This inventory complements a previous survey of habitat in Ontario waters of the Detroit River (OMNR,1993). It is a starting point for balanced and sustained use of the river for natural resource conservation and economic development. The objectives of the inventory were to: (1) locate candidate sites for protection and restoration of fish and wildlife habitat in Michigan waters of the Detroit River; (2) describe the ownership and size of each site, as well as its potential for habitat protection and restoration; and (3) subjectively assess the extent to which existing habitat along the river is productive of fish and wildlife and protected from land uses that have degraded or destroyed such habitat.
Manny, Bruce A.
Habitat Suitability Information: Common Shiner.
National Technical Information Service (NTIS)
A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for the common shiner (Notropis cornutus). The models are scaled to produce indices of habitat suitability between 0 (unsuitable habitat) and 1 (opt...
J. G. Trial C. S. Wade J. G. Stanley P. C. Nelson
Spatiotemporal variability of stream habitat and movement of three species of fish.
Relationships between environmental variability and movement are poorly understood, due to both their complexity and the limited ecological scope of most movement studies. We studied movements of fantail (Etheostoma flabellare), riverweed (E. podostemone), and Roanoke darters (Percina roanoka) through two stream systems during two summers. We then related movement to variability in measured habitat attributes using logistic regression and exploratory data plots. We indexed habitat conditions at both microhabitat (i.e., patches of uniform depth, velocity, and substrate) and mesohabitat (i.e., riffle and pool channel units) spatial scales, and determined how local habitat conditions were affected by landscape spatial (i.e., longitudinal position, land use) and temporal contexts. Most spatial variability in habitat conditions and fish movement was unexplained by a site's location on the landscape. Exceptions were microhabitat diversity, which was greater in the less-disturbed watershed, and riffle isolation and predator density in pools, which were greater at more-downstream sites. Habitat conditions and movement also exhibited only minor temporal variability, but the relative influences of habitat attributes on movement were quite variable over time. During the first year, movements of fantail and riverweed darters were triggered predominantly by loss of shallow microhabitats; whereas, during the second year, microhabitat diversity was more strongly related (though in opposite directions) to movement of these two species. Roanoke darters did not move in response to microhabitat-scale variables, presumably because of the species' preference for deeper microhabitats that changed little over time. Conversely, movement of all species appeared to be constrained by riffle isolation and predator density in pools, two mesohabitat-scale attributes. Relationships between environmental variability and movement depended on both the spatiotemporal scale of consideration and the ecology of the species. Future studies that integrate across scales, taxa, and life-histories are likely to provide greater insight into movement ecology than will traditional, single-season, single-species approaches. PMID:17106722
Roberts, James H; Angermeier, Paul L
Adolescents' perspectives of parental practices influence diabetic adherence and quality of life.
This study investigated whether perceived parental support and different parenting styles were related to adherence to diabetes management, metabolic control, and perceived quality of life of adolescents diagnosed with type 1 diabetes. Adolescents between 12 and 18 years of age (N = 102) diagnosed with type 1 diabetes for at least one year participated. Parents were classified into one of four groups (authoritative, authoritarian, permissive, or neglectful) based on their adolescents' surveyed perceptions of their general support and their overall responsiveness and demandingness. Perceived parental support was significantly correlated with adherence. Adolescents who perceived their parents to have authoritative parenting styles also had better adherence to their prescribed treatment plan as well as better perceived quality of life. Adolescents experience better management outcomes when adolescents and parents become interdependent by working together to achieve these outcomes. PMID:24027952
Mlynarczyk, Susan M
[Influence of music on the quality of life of palliative cancer patients].
A small prospective, multicentre study examined the effect of a perceptual acoustic stimulus (music) on quality of life of palliative cancer patients with special reference to pain.14 test subjects (m?=?4, w?=?10; age 67.6 (SD?=?9.7)) in stationary or mobile care situation were included. The current therapy has not been modified.Each subject received a CD with 12 songs, an information folder, a guide to using the CD as well as a questionnaire.The offered music therapy was experienced by all study participants (100?%) as helpful. The effect was seen differently in psychological, physical, spiritual, and social quality of life. The pain was reduced nociable in 11 out of 14 participants.From the experience of the autors we demand to offer and enable music therapy in palliative care to each patient, but also adapt to their individual needs. PMID:24723126
Polt, G■nter; Fink, Margit; Schieder, Helga; Tanzmeister, Silke
Psychopathology and quality of life burden in chronic daily headache: influence of migraine symptoms
The aim of this study is to compare the psychopathology and the quality of life of chronic daily headache patients between\\u000a those with migraine headache and those with tension-type headache. We enrolled 106 adults with chronic daily headache (CDH)\\u000a who consulted for the first time in specialised centres. The patients were classified according to the IHS 2004 criteria and\\u000a the
A. Autret; S. Rimbaux-Lepage; D. Valade; S. Debiais
Social and biological early life influences on severity of dental caries in children aged 6 years
Objective: To investigate the relationship between social and biological conditions experienced in very early life and dental caries in children aged 6 years. Methods: The design was a dental caries cross-sectional study nested in a birth cohort study started in Pelotas, Brazil, in 1993. The cross- sectional study was carried out in 1999. A random sample of 400 6-year-old children
Peres MA; Latorre MRDO; Sheiham A; Peres KGA; Barros FC; Hernandez PG; Marco Aurelio Peres; Dias de Oliveira Latorre
Growth history and intrinsic factors influence risk assessment at a critical life transition for a fish
Making the appropriate decision in the face of predation risk dictates the fate of prey, and predation risk is highest at\\u000a life history boundaries such as settlement. At the end of the larval phase, most coral reef fishes enter patches of reef containing\\u000a novel predators. Since vision is often obscured in the complex surroundings, chemical information released from damaged conspecific
O. M. L—nnstedt; M. I. McCormick
Influence of Storage Conditions on ShelfLife of Dried Beef Product (Kilishi)
The effects of storage methods on the shelf-life of dried beef product (Kilishi) were studied under ambient conditions for a period of forty-two days to compare traditional production and packaging system with a potassium sorbate (anti-fungal agent) treatment and modern packaging system. Changes in proximat e composition and microbial counts for the control and treated samples were significant. Moisture and
Ogbonnaya Chukwu; Linus Ithoitsoyah Imodiboh
Temperature influence on life table statistics of the chicken mite Dermanyssus gallinae (Acari: Dermanyssidae)
An age-specific life table for the chicken miteDermanyssus gallinae (DeGeer, 1778) was based on various observations carried out at 25¯C. The generation time was calculated to be 16.8 days; the intrinsic rate of natural increase was 0.12 per day, and the net reproductive rate was 7.2. A nonlinear function was found satisfactory to describe the developmental rate of the different
Veronika Maurer; Johann Baumgðrtner
Influence of harvest maturity on quality and shelf-life of litchi fruit ( Litchi chinensis Sonn.)
The impact of picking maturity on eating quality and shelf-life of cold-stored litchi fruit was evaluated for the Thai cultivars Hong Huey and Chacapat. Pericarp colour at harvest was specified by a litchi maturity index (LMI) and subsequent pericarp browning by a postharvest litchi colour index (PLCI), both being application-oriented indices deduced from the CIELab colour space. Fruit lots harvested
Mareike Reichel; Reinhold Carle; Pittaya Sruamsiri; Sybille Neidhart
River hydrological seasonality influences life history strategies of tropical riverine fishes.
Under a particular set of selective forces, specific combinations of traits (strategies) will be favored in a given population, within the particular constraints of the considered species. For fishes, three demographic strategies have been suggested to result from adaptive responses to environmental predictability (i.e., seasonality): periodic, opportunistic and equilibrium [Winemiller KO, Rose KA (1992) Patterns of life-history diversification in North American fishes: implications for population regulation. Can J Fish Aquat Sci 49:2196-2218]. These strategies optimize fitness within predictable, unpredictable and stable systems, respectively. We tested these predictions of life history trait distribution along a gradient of hydrologic seasonality in West African tropical rivers at the drainage basin scale. We used logistic regression of species presence-absence data to test whether dominant life history traits of species caused community compositional change in response to a gradient of seasonality in hydrologic regime across basins. After accounting for taxonomic relatedness, species body size and statistical redundancy inherent to related traits, we found a higher proportion of species producing a great number of small oocytes, reproducing within a short period of time and presenting a low degree of parental care (the periodic strategy) in highly seasonal drainage basins (e.g., rivers with a short and predictable favorable season). Conversely, in more stable drainage basins (e.g., rivers with a wet season of several months), we observed a greater proportion of species producing small numbers of large oocytes, reproducing within a long period of time and providing parental care to their offspring (the equilibrium strategy). Our results suggest that distributions of tropical freshwater fishes at the drainage basin scale can be partly explained by the match between life history strategies and seasonality gradients in hydrological conditions. PMID:18368426
Tedesco, P A; Hugueny, B; Oberdorff, T; D■rr, H H; MÕrigoux, S; de MÕrona, B
Habitat complexity facilitates coexistence in a tropical ant community
The role of habitat complexity in the coexistence of ant species is poorly understood. Here, we examine the influence of habitat complexity on coexistence patterns in ant communities of the remote Pacific atoll of Tokelau. The invasive yellow crazy ant, Anoplolepis gracilipes (Smith), exists in high densities on Tokelau, but still coexists with up to seven other epigeic ant species.
M. Sarty; K. L. Abbott; P. J. Lester
Influence of sleep disturbance on quality of life of patients with epilepsy.
The frequency of sleep disturbances in patients with epilepsy and their impact on quality of life (QoL) have been documented in a few reports, and the results are conflicting. We identified 124 consecutive epilepsy out-patients who visited the epilepsy out-patient clinics at the University Hospital of Alexandroupolis, the AHEPA Hospital in Thessaloniki and the Aeginitio Hospital in Athens. We measured excessive daytime sleepiness (EDS) with the Epworth Sleepiness Scale (ESS), obstructive sleep apnea (OSA) with the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ), and insomnia with the Athens Insomnia Scale (AIS). We evaluated quality of life by the Quality of Life in Epilepsy Inventory (QOLIE-31). EDS was found in 16.9% (21/124) of epileptic patients, OSA in 28.2% (35/124), and insomnia in 24.6% (30/122). In multivariate analysis, we found that insomnia was an independent negative factor for Total score (p<0.001), Overall QoL (p=0.002), Emotional well-being (p<0.001), Energy/fatigue (p<0.001), Cognitive functioning (p=0.04) and Social functioning (p=0.03), and OSA only for Cognitive functioning (p=0.01). According to our findings, EDS, OSA, and insomnia are frequent in epileptic patients. Epileptic patients with sleep disturbance, mainly insomnia, have significant QoL impairment. PMID:18396419
Piperidou, Charitomeni; Karlovasitou, Anna; Triantafyllou, Nikolaos; Terzoudi, Aikaterini; Constantinidis, Theodoros; Vadikolias, Konstantinos; Heliopoulos, Ioannis; Vassilopoulos, Dimitrios; Balogiannis, Stavros
COMT Val158Met polymorphism interacts with stressful life events and parental warmth to influence decision making.
Both genetic and environmental factors have been shown to influence decision making, but their relative contributions and interactions are not well understood. The present study aimed to reveal possible gene-environment interactions on decision making in a large healthy sample. Specifically, we examined how the frequently studied COMT Val(158)Met polymorphism interacted with an environmental risk factor (i.e., stressful life events) and a protective factor (i.e., parental warmth) to influence affective decision making as measured by the Iowa Gambling Task. We found that stressful life events acted as a risk factor for poor IGT performance (i.e., high reward sensitivity) among Met carriers, whereas parental warmth acted as a protective factor for good IGT performance (i.e., higher IGT score) among Val/Val homozygotes. These results shed some new light on gene-environment interactions in decision making, which could potentially help us understand the underlying etiology of several psychiatric disorders associated with decision making impairment. PMID:22997551
He, Qinghua; Xue, Gui; Chen, Chuansheng; Lu, Zhong-Lin; Chen, Chunhui; Lei, Xuemei; Liu, Yuyun; Li, Jin; Zhu, Bi; Moyzis, Robert K; Dong, Qi; Bechara, Antoine
Storage length, storage temperature, and lean formulation influence the shelf-life and stability of traditionally packaged ground beef.
The effect of storage length and temperature on the shelf life of three ground beef formulations (lean:fat: 73:27, 81:19 and 91:9) was investigated. Coarsely ground beef was stored at -1.7 or 2.3¯C for up to 28d. Traditional overwrap packages were produced every 7d prior to retail display for 24h. Lipid oxidation (TBARS), subjective color, instrumental color, and aerobic bacteria were evaluated after 0 and 24h of display. Formulation influenced initial L* and subjective color values (P<0.05). Storage temperature did not affect initial color, but product stored at 2.3¯C was more discolored after 24h (P<0.05). Aerobic bacteria increased as storage d and temperature increased (P<0.05). Initial TBARS increased through d 21, but were lower after 28d. Overall, initial characteristics depended on formulation; however, ground beef shelf-life and stability were largely influenced by storage length and storage temperature. PMID:23793085
Martin, J N; Brooks, J C; Brooks, T A; Legako, J F; Starkey, J D; Jackson, S P; Miller, M F
Significant life experience: Exploring the lifelong influence of place-based environmental and science education on program participants
NASA Astrophysics Data System (ADS)
Current research provides a limited understanding of the life long influence of nonformal place-based environmental and science education programs on past participants. This study looks to address this gap, exploring the ways in which these learning environments have contributed to environmental identity and stewardship. Using Dorothy Holland's approach to social practice theory's understanding of identity formation, this study employed narrative interviews and a close-ended survey to understand past participants' experience over time. Participants from two place-based environmental education programs and one science-inquiry program were asked to share their reflections on their program experience and the influence they attribute to that experience. Among all participants, the element of hands-on learning, supportive instructors, and engaging learning environments remained salient over time. Participants of nature-based programs demonstrated that these programs in particular were formative in contributing to an environmental stewardship identity. Social practice theory can serve as a helpful theoretical framework for significant life experience research, which has largely been missing from this body of research. This study also holds implications for the fields of place-based environmental education, conservation psychology, and sustainability planning, all of which look to understand and increase environmentally sustainable practices.
Colvin, Corrie Ruth
Influence and interaction of genetic polymorphisms in the serotonin system and life stress on antidepressant drug response.
Variation in genes implicated in serotonin neurotransmission may interact with environmental factors to influence antidepressant response. We aimed to determine how a range of polymorphisms in serotonergic genes determine this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample. In total, 14 single nucleotide polymorphisms (SNPs) in coding regions of 10 serotonergic genes (HTR1A, HTR1B, HTR1D, HTR2A, HTR3A, HTR3C, HTR3D, HTR3E, HTR5A and TPH2) were genotyped in 308 Chinese Han patients with major depressive disorder. Response to 6 weeks' antidepressant treatment was determined by change in the 17-item Hamilton Depression Rating Scale (HDRS-17) score, and previous stressful events were evaluated by the Life Events Scale (LES) and Childhood Trauma Questionnaire-Short Form (CTQ-SF). Two 5-HT1B receptor SNPs (rs6296 and rs6298) and one tryptophan hydroxylase2 (rs7305115) SNP were significantly associated with antidepressant response in this Chinese sample, as was a haplotype in TPH2 (rs7305115 and rs4290270). A gene-gene interaction on antidepressant response was found between SNPs in HTR1B, HTR3A and HTR5A in female subjects. The HTR1B SNPs demonstrated interaction with recent stress, while that for TPH2 interacted with childhood trauma to influence antidepressant response. PMID:21937687
Xu, Zhi; Zhang, Zhijun; Shi, Yanyan; Pu, Mengjia; Yuan, Yonggui; Zhang, Xiangrong; Li, Lingjiang; Reynolds, Gavin P
Effects of Gravity on Cells, Tissues, and Organisms: Their Implications on Habitat and Human Support in Microgravity
NASA Technical Reports Server (NTRS)
This presentation will demonstrate that gravity plays a major role in advanced human life support in a closed habitat. The examples include, but are not limited to, control of purity in drinking water supplies (application of biocides), control of urine in space rodent habitats and operation of space septic tanks (waste management). Our goal is to understand and determine possible mechanisms that describe the process by which cells anchor to a substrate to form dynamic, vibrant communities of cells which influence human health in absence of gravity. The balance of all forces (mechanotransduction) acting on a cell will determine whether a cell thrives and multiplies or dies in a process called apoptosis and/or necrosis. The balance of forces are tightly coupled to the transport of nutrients and metabolic products (biochemotransduction) to and from the cell interface. We will highlight our effort to improve astronaut health by showing that microgravity life support systems have to be designed differently from those on Earth.
Kizito, John
Effects of spatial habitat heterogeneity on habitat selection and annual fecundity for a migratory forest songbird
Understanding how spatial habitat patterns influence abundance and dynamics of animal populations is a primary goal in landscape ecology. We used an information-theoretic approach to investigate the association between habitat patterns at multiple spatial scales and demographic patterns for black-throated blue warblers (Dendroica caerulescens) at 20 study sites in west-central Vermont, USA from 2002 to 2005. Sites were characterized by: (1) territory-scale shrub density, (2) patch-scale shrub density occurring within 25 ha of territories, and (3) landscape-scale habitat patterns occurring within 5 km radius extents of territories. We considered multiple population parameters including abundance, age ratios, and annual fecundity. Territory-scale shrub density was most important for determining abundance and age ratios, but landscape-scale habitat structure strongly influenced reproductive output. Sites with higher territory-scale shrub density had higher abundance, and were more likely to be occupied by older, more experienced individuals compared to sites with lower shrub density. However, annual fecundity was higher on sites located in contiguously forested landscapes where shrub density was lower than the fragmented sites. Further, effects of habitat pattern at one spatial scale depended on habitat conditions at different scales. For example, abundance increased with increasing territory-scale shrub density, but this effect was much stronger in fragmented landscapes than in contiguously forested landscapes. These results suggest that habitat pattern at different spatial scales affect demographic parameters in different ways, and that effects of habitat patterns at one spatial scale depends on habitat conditions at other scales. ?? Springer Science+Business Media B.V. 2009.
Cornell, K. L.; Donovan, T. M.
Influences of the Landscape on Life Cycle Carbon Intensity of Biofuels
NASA Astrophysics Data System (ADS)
Biofuels derived from first (sugar and starch based) and second (lignocellulosic) generation agricultural feedstocks will continue to expand into the market between now and 2022 as incentivized through the federal Energy Independence and Security Act (EISA). Nitrogen use is one of the key environmental concerns within the life cycle since it is both the dominant source of life cycle greenhouse gas (GHG) emissions (energy from N fertilizer production and N2O emissions) and poses risks of reactive N movement throughout agricultural landscapes and watersheds. The other dominant components of the feedstock production on life cycle GHG emissions are tillage and land use change impacts on soil organic carbon (SOC). Opportunities to reduce reactive N through winter double crops may satisfy the dual goal of mitigating N2O emissions and reducing NO3 loses while meeting the objectives of EISA. However, changes in N2O, NO3, and SOC are variable within the agricultural landscape due to soil texture, climate, and crop rotation history thereby increasing the complexity of developing mitigation recommendations. Moreover, the inherent variability in N2O emissions makes it difficult to develop single life cycle carbon intensity profiles for specific fuel pathways that apply across the US, since those pathways will have geographic dependencies. Estimating the expected changes in N2O and SOC is an integral part of quantifying the life cycle GHG profile of biofuels derived from winter double crop feedstocks, while NO3 losses affect both indirect N2O emissions and water quality. The biogeochemical model DayCent was used to simulate the impact of growing winter barley as a double crop following corn before soybean establishment during the winter fallow period for six states in the Mid Atlantic region of the Eastern US on SOC and direct and indirect N2O. EPA is currently reviewing the addition of an advanced fuel pathway for winter barley in the Mid Atlantic region as part of the RFS2 program. Modeling results showed that N2O emissions varied across the landscape; NO3 leaching was higher on the sandy coastal plains soils leading to higher indirect N2O emissions, but direct N2O emissions were higher on the finer textured clay soils. In spite of the variabilities present due to landscape characteristics noted above, when DayCent estimates of changes in N2O emissions and SOC from addition of winter barley into the corn soybean rotation in the Mid Atlantic region were coupled with life cycle inventory results developed for winter barley-to-ethanol fuel expected to be produced from this region, results indicate that the fuel could meet advanced fuel status under EISA because the life cycle carbon intensity of the biofuel is at least 50% lower than a baseline gasoline fuel. This case study demonstrates a possible benefit of one approach to nitrogen management that also meets an important market opportunity mandated by law.
Adler, P. R.; Del Grosso, S.; Parton, W. J.; Spatari, S.
Influence of habitat structure and mouth dynamics on avifauna of intermittently-open estuaries: A study of four small South African estuaries
NASA Astrophysics Data System (ADS)
Habitat composition was a major factor in determining waterbird species composition and abundance, particularly the area of floodplain and vegetated channel in four intermittently open estuaries (IOEs) in the warm-temperate coastal biogeographical region of South Africa. Average bird densities on the four estuaries varied from 0.5 to 4.2 birds per hectare, and community composition differed significantly between estuaries. However, the considerable variation in abundance of macrophytes did not have a detectable effect on waterbirds. Under closed mouth conditions, piscivorous birds dominated the avifauna. Each estuary's avifauna responded differently in terms of changes in feeding guild composition when the mouth opened. Bird abundance changed immediately after breaching, but not consistently. Diversity was significantly higher under open-mouth conditions for three of the four estuaries, and species composition was significantly different from that under closed-mouth conditions at all four estuaries. Changes in mouth dynamics as a result of climate change, water abstraction and artificial breaching could lead to significant changes in estuarine fauna.
Ter—rde, Anja I.; Turpie, Jane K.
Early colonization of stone by freshwater lichens of restored habitats: a case study in northern Italy.
This study evaluated the effectiveness and life-strategies of freshwater lichens in colonizing newly constructed stone structures in low-elevation streams in a small nature reserve in northern Italy. Species richness, size of thalli, morphological and ontogenetic traits of the species were related to the age of restored habitats. Lichen colonization was surprisingly rapid, indicating the high potential of these organisms in colonizing restored habitats. However, the species pool found in the restored habitats was different than that found in natural sites in the same study area. The age of newly constructed habitats influenced both species richness and thallus size of the two most frequent Verrucaria species. Verrucaria aquatilis was a rapid colonizer invading the substrate by several small-sized and thin thalli which soon supported a large number of small perithecia whose development began in the earlier phase of thallus formation. V. elaeomelaena, on the contrary, developed according to a different strategy, establishing a thick thallus on which relatively large perithecia were formed much later than in V. aquatilis. As these taxa are important photoautotrophic components of freshwater ecosystems more ecological knowledge is needed to evaluate the effectiveness of different measures of river restoration on lichen communities. The main practical implication of our study is related to the value of small stone structures, such as riffles and ramps, for enhancing the establishment of pioneer freshwater lichens to rapidly colonize newly available substrata. PMID:19589560
Nascimbene, Juri; Th■s, Holger; Marini, Lorenzo; Nimis, Pier Luigi
15 up : charting the influence of literacy and numeracy achievement on later life
A successful involvement with further education, training and employment can be predicted through a student's performance in literacy and numeracy at secondary school level. The Longitudinal Surveys of Australian Youth (LSAY) is a program that makes it possible to assess the influence of achievements in year 9, combined with the successful completion of year 12, while tracking the progress of
Sheldon Rothman
Current Life Concerns of Early Adolescents and Their Mothers: Influence of Maternal HIV.
ERIC Educational Resources Information Center
This study examined influences of maternal HIV on concerns among inner-city minority families. Findings indicated that beyond concerns reported by early adolescent children of HIV-negative mothers, concerns of children of HIV-positive mothers included mothers' sickness and death, adult responsibilities, and uncertainty about their futures.
Brackis-Cott, Elizabeth; Mellins, Claude Ann; Block, Megan
Australian Women and Careers: Psychological and Contextual Influences over the Life Course.
ERIC Educational Resources Information Center
A study examined psychological and contextual influences on the courses of Australian women's lives and careers. Data were obtained from two sources: (1) the Career Development Project (CDP), a longitudinal study of 3,000 Australian men and women who were selected from an initial sample of 17-year-olds in 1973 and whose educational and career
Poole, Millicent E.; Langan-Fox, Janice
Neighborhood and School Influences on the Family Life and Mathematics Performance of Eighth-Grade Students.
ERIC Educational Resources Information Center
This study examines how neighborhoods, schools, and families can influence the mathematics achievement of eighth graders, using data from the 1988 National Educational Longitudinal Study combined with U.S. Census data. These data allow simultaneous analysis of all aspects of students' lives. Results indicate that there are associations between
Catsambis, Sophia; Beveridge, Andrew A.
The Areal Extent of Brown Shrimp Habitat Suitability in Mobile Bay, Alabama USA: Targeting Vegetated Habitat Restoration
The availability of wetlands and shallow water habitats significantly influences Gulf of Mexico (GOM) penaeid shrimp fishery productivity. However, the GOM region has the highest rate of wetland loss in the U.S. Protection and management of these vital GOM habitats are critical t...
NORTHWOODS Wildlife Habitat Database
NSDL National Science Digital Library
Created through a joint effort of the USDA Forest Service's North Central Forest Experiment Station (NCFES) and seven national forests in the Upper Great Lakes Region, NORTHWOODS is a wildlife habitat database featuring "information about the habitat needs of 389 species of reptiles, amphibians, birds, and mammals in the Upper Great Lakes Region." The database compiles common and scientific names, species occurrences in 20 aquatic and terrestrial habitat types, species abundances and seasonal use in seven national forests, and species conservation status. The NORTHWOODS database is available in tab-delimited ASCII file format.
The research described in this project deals with the influence of human activities on aquatic and aquatic-dependent biota at landscape, watershed, and regional scales. Specifically, it will examine watershed and landscape scale habitat issues affecting salmon and native fishes i...
Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds
In general, tropical birds have a slow pace of life, lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animals life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.
Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.
Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.
In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080
Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B
Gestational and early life influences on infant body composition at one year.
Excess weight gain during both pre- and postnatal life increases risk for obesity in later life. Although a number of gestational and early life contributors to this effect have been identified, there is a dearth of research to examine whether gestational factors and weight gain velocity in infancy exert independent effects on subsequent body composition and fat distribution. The purpose of this study was to test the hypothesis that birth weight, as a proxy of prenatal weight gain, and rate of weight gain prior to 6 months would be associated with total and truncal adiposity at 12 months of age. Healthy, term infants (N=47) were enrolled in the study and rate of weight gain (g/day) was assessed at 0-3 months, 3-6 months, and 6-12 months. Total and regional body composition were measured by dual-energy X-ray absorptiometry at 12 months. Stepwise linear regression modeling indicated that lean mass at 12 months, after adjusting for child length, was predicted by rate of weight gain during each discrete period of infancy (P<0.05), and by maternal pre-pregnancy BMI (P<0.05). Total fat mass at 12 months was predicted by rate of weight gain during each discrete period (P<0.01), and by older maternal age at delivery (P<0.05). Trunk fat mass at 12 months, after adjusting for leg fat mass, was predicted by rate of weight gain from 0-3 months and 3-6 months (P<0.05). Results suggest that growth during early infancy may be a critical predictor of subsequent body composition and truncal fat distribution. PMID:22628019
Chandler-Laney, P C; Gower, B A; Fields, D A
Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat
NASA Technical Reports Server (NTRS)
NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat module consists of a 2-m-high barrel with 0.6-mhigh end domes forming the 56-cubicmeter pressure vessel, and a 19-squaremeter floor area. The module has up to four docking ports located orthogonally from each other around the perimeter, and up to one docking port each on the top or bottom end domes. In addition, the module has mounting trusses top and bottom for equipment, and to allow docking with the ATHLETE mobility system. Novel or unique features of the HDU vertical habitat module include the nodelike function with multiple pressure hatches for docking with other versions of itself and other modules and vehicles; the capacity to be carried by an ATHLETE mobility system; and the ability to attach inflatable 'attic' domes to the top for additional pressurized volume.
Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.
Symbiotic state influences life-history strategy of a clonal cnidarian.
Along the North American Pacific coast, the common intertidal sea anemone Anthopleura elegantissima engages in facultative, flexible symbioses with Symbiodinium muscatinei (a dinoflagellate) and Elliptochloris marina (a chlorophyte). Determining how symbiotic state affects host fitness is essential to understanding the ecological significance of engaging in such flexible relationships with diverse symbionts. Fitness consequences of hosting S. muscatinei, E. marina or negligible numbers of either symbiont (aposymbiosis) were investigated by measuring growth, cloning by fission and gonad development after 8.5-11 months of sustained exposure to high, moderate or low irradiance under seasonal environmental conditions. Both symbiotic state and irradiance affected host fitness, leading to divergent life-history strategies. Moderate and high irradiances led to a greater level of gonad development in individuals hosting E. marina, while high irradiance and high summer temperature promoted cloning in individuals hosting S. muscatinei and reduced fitness of aposymbiotic anemones. Associating with S. muscatinei may contribute to the success of A. elegantissima as a spatial competitor on the high shore: (i) by offsetting the costs of living under high temperature and irradiance conditions, and (ii) by promoting a high fission rate and clonal expansion. Our results suggest that basic life-history characteristics of a clonal cnidarian can be affected by the identity of the endosymbionts it hosts. PMID:25009060
Bingham, Brian L; Dimond, James L; Muller-Parker, GisÒle
Influence of allergy and bacterial colonization on the quality of life in nasal polyposis patients.
Allergies and bacterial colonization are frequently found in patients with chronic rhinosinuitis with nasal polyposis (CRSwNP). The aim of this study was to identify patients with allergy and present microorganisms in ethmoid sinus among the patients with refractory CRSwNP undergoing surgical treatment at the University Hospital Centre Osijek, and to compare their life quality, defined by SNOT-20 analysis (sinonasal outcome test) to the rest of patients, and a control group consisting of patients undergoing septoplasty but free of allergy and/or CRS. An additional aim was to identify specific types and strains of microorganisms (bacteria and fungi) found in these patients, in order to compare them to other reports, and to revise the empirical antimicrobial therapy. In this paper we demonstrate a high incidence of bacterial colonization (83.3%) among CRSwNP patients. As in previous studies, gram positive aerobes were the most frequently isolated bacteria and all of them were covered by specific antibiotics given before the specimen collection. Allergy was found in only 20% of these patients, who presented with a reduced quality of life when compared to the control group and CRSwNP without allergy. Significantly more frequent dominant symptoms in these patients were cough, frustration and irritation. In the line with this finding is the objective assessment by endoscopy (Malm score) that showed more prominent nasal polyposis in allergy patients. PMID:24611326
Mihalj, Hrvoje; Loncar, Mirela Baus; Mihalj, Martina; Zubci?, Zeljko; Vceva, Andrijana; Bujak, Maro; Males, Josip; Mari?, Andela
Influence of functional unit on the life cycle assessment of traction batteries
Goal, Scope and Background This paper describes the influence of the choice of the functional unit on the results of an environmental assessment of different\\u000a battery technologies for electric and hybrid vehicles. Battery, hybrid and fuel cell electric vehicles are considered as being\\u000a environmentally friendly. However, the batteries they use are sometimes said to be environmentally unfriendly. At the current\\u000a state
Julien Matheys; Wout Van Autenboer; Jean-Marc Timmermans; Joeri Van Mierlo; Peter Van den Bossche; Gaston Maggetto
How Does Residents Satisfaction with Community Services Influence Quality of Life (QOL) Outcomes?
Grzeskowiak et al. [Journal of Regional Analysis and Policy 33(2):136, 2003] conducted a study that empirically tested a model that integrates the relationships among determinants and outcomes of residents\\u000a satisfaction with community services. We build on their model in attempt to explain how residents satisfaction with community\\u000a services influence satisfaction with the community at large (community well-being) and satisfaction with
M. Joseph Sirgy; Tao Gao; Robert F. Young
Inbreeding depression in an insect with maternal care: influences of family interactions, life stage and offspring sex.
Although inbreeding is commonly known to depress individual fitness, the severity of inbreeding depression varies considerably across species. Among the factors contributing to this variation, family interactions, life stage and sex of offspring have been proposed, but their joint influence on inbreeding depression remains poorly understood. Here, we demonstrate that these three factors jointly shape inbreeding depression in the European earwig, Forficula auricularia. Using a series of cross-breeding, split-clutch and brood size manipulation experiments conducted over two generations, we first showed that sib mating (leading to inbred offspring) did not influence the reproductive success of earwig parents. Second, the presence of tending mothers and the strength of sibling competition (i.e. brood size) did not influence the expression of inbreeding depression in the inbred offspring. By contrast, our results revealed that inbreeding dramatically depressed the reproductive success of inbred adult male offspring, but only had little effect on the reproductive success of inbred adult female offspring. Overall, this study demonstrates limited effects of family interactions on inbreeding depression in this species and emphasizes the importance of disentangling effects of sib mating early and late during development to better understand the evolution of mating systems and population dynamics. PMID:23981229
Meunier, J; K—lliker, M
Habitat selection influences sex distribution, morphology, tissue biochemistry, and parasite load of juvenile coho salmon in the West Fork Smith River, Oregon
Given the strong influence of water temperature on salmonid physiology and behavior, in the summers of 2004 and 2005 we studied juvenile male and female coho salmon Oncorhynchus kisutch in two reaches of Oregon?s West Fork Smith River with different thermal profiles. Our goals we...
Habitat Selection Influences Sex Distribution, Morphology, Tissue Biochemistry, and Parasite Load of Juvenile Coho Salmon in the West Fork Smith River, Oregon
Given the strong influence of water temperature on salmonid physiology and behavior, in the summers of 2004 and 2005 we studied juvenile male and female coho salmon Oncorhynchus kisutch in two reaches of Oregon's West Fork Smith River with different thermal profiles. Our goals were to compare the body morphology, tissue biochemistry, genetics, and parasite load and determine whether sex,
Kenneth J. Rodnick; Sophie St.-Hilaire; Pavan K. Battiprolu; Steven M. Seiler; Michael L. Kent; Madison S. Powell; Joseph L. Ebersole
NSDL National Science Digital Library
Observing Wetland Habitats contains tips on finding wetlands to explore and wetland scavenger hunt observation sheets that can be used as a starting point for discovery. While on their scavenger hunt, students can look for adaptations in plants and animals that help them live in a partially wet habitat. After the students have finished their scavenger hunt, they can share what they've seen and heard.
Influence of packaging on the aroma stability of strawberry syrup during shelf life.
Different types of packaging (glass bottle, PVC, and PET) were compared for the preservation of aroma quality of a strawberry syrup during shelf life. Esters, alcohols, and aldehydes were analyzed by solid-phase micro-extraction (SPME) and solvent extraction. During storage, hydrolysis of esters in acids and alcohols led to a modification of the aroma profile which can be explained by the replacement of "fruity" and "fresh" notes by "dairy note" in the syrup. Aroma compounds that are responsible for fruity notes, such as methyl cinnamate, methyl anthranilate, and methyl dihydrojasmonate, were strongly reduced after 90 days. This could be explained by a selective interaction of these compounds with the polymer matrix (PET or PVC). After 330 days, a later and important decrease of the "fruity notes" occurred in both PETs; so PVC2 and the glass bottle were found to be able to maintain a balanced aroma for long-term storage. PMID:11368591
Ducruet, V; Fournier, N; Saillard, P; Feigenbaum, A; Guichard, E
Influence of natural extracts on the shelf life of modified atmosphere-packaged pork patties.
In this study four natural extracts from tea (TEA), grape (GRA), chestnut (CHE) and seaweed (SEA) with potential antioxidant activity were evaluated in pork patties. During 20 days of storage in modified atmosphere packs at 2¯C, pH, colour, lipid oxidation and microbial spoilage parameters of raw minced porcine patties were examined and compared with a synthetic antioxidant (BHT) and control (CON) batch. Due to their higher polyphenol content, GRA and TEA extracts were the most effective antioxidants against lipid oxidation, also limiting colour deterioration. In addition, both natural extracts led to a decrease of total viable counts (TVC), lactic acid bacteria (LAB), Pseudomonas and psychotropic aerobic bacteria compared to the control. Among the four natural compounds tested, tea and grape extracts showed the most potential as alternatives to commercial antioxidants, for increasing the quality and extending the shelf-life of porcine patties. PMID:24008060
Lorenzo, JosÕ M; Sineiro, Jorge; Amado, Isabel R; Franco, Daniel
Evolutionary influences on body size in free-living and parasitic isopods
The influence of mode of life and habitat characteristics on the evolution of body size in isopods was investigated in a comparative analysis based on data from 746 free-living and parasitic species. The phylogeny of isopods allowed 24 independent comparisons to be made between higher taxa (families or superfamilies), each corresponding to a separate branching event. The evolution of parasitism
Robert Poulin
Influence of obesogenic behaviors on health-related quality of life in adolescents.
We aimed to prospectively examine the association between the combined effects of obesogenic behaviors on quality of life (QOL) in adolescents. Of 2353 Sydney schoolchildren surveyed (median age 12.7 years), 1,213 were re-examined 5 years later at age 17-18. Children completed activity and food-frequency questionnaires. An unhealthy behavior score was calculated, allocating 1 point for the following: <60 minutes of total physical activity/ day; ?2 hours of screen time/ day; consumed salty snack foods and/or confectionery ?5 times per week; ?1 serves of soft drinks and/or cordial/ day; and not consuming both ?2 serves of fruit and ?3 serves of vegetables/ day. Health-related QOL was assessed by the Pediatric Quality of Life Inventory (PedsQL). The prevalence of 0, 1, 2, 3, 4, and 5 lifestyle risk factors was 4.2%, 17.1%, 30.7%, 30.5%, 13.9% and 3.6%, respectively. After multivariable- adjustment, children engaging in 5 versus 0 unhealthy behaviors had 9.2-units lower PedsQL physical summary score (ptrend=0.001), five years later. Boys reporting 4 or 5 lifestyle risk factors compared to their peers reporting none or one at baseline, had lower total and physical summary scores at follow-up, ptrend=0.02 and 0.01, respectively. Girls engaging in 4 or 5 versus 0 or 1 unhealthy behaviors, had 4.6-units lower physical summary score (ptrend=0.04), five years later. The number of obesogenic lifestyle risk factors was independently associated with subsequent poorer QOL, particularly physical health, during adolescence. These findings underscore the importance of targeting lifestyle behaviors to promote general well-being and physical functioning in adolescents. PMID:24561980
Gopinath, Bamini; Louie, Jimmy C Y; Flood, Victoria M; Burlutsky, George; Hardy, Louise L; Baur, Louise A; Mitchell, Paul
Plant origin and ploidy influence gene expression and life cycle characteristics in an invasive weed
Background Ecological, evolutionary and physiological studies have thus far provided an incomplete picture of why some plants become invasive; therefore we used genomic resources to complement and advance this field. In order to gain insight into the invasive mechanism of Centaurea stoebe we compared plants of three geo-cytotypes, native Eurasian diploids, native Eurasian tetraploids and introduced North American tetraploids, grown in a common greenhouse environment. We monitored plant performance characteristics and life cycle habits and characterized the expression of genes related to constitutive defense and genome stability using quantitative PCR. Results Plant origin and ploidy were found to have a significant effect on both life cycle characteristics and gene expression, highlighting the importance of comparing appropriate taxonomic groups in studies of native and introduced plant species. We found that introduced populations of C. stoebe exhibit reduced expression of transcripts related to constitutive defense relative to their native tetraploid counterparts, as might be expected based on ideas of enemy release and rapid evolution. Measurements of several vegetative traits were similar for all geo-cytotypes; however, fecundity of tetraploids was significantly greater than diploids, due in part to their polycarpic nature. A simulation of seed production over time predicts that introduced tetraploids have the highest fecundity of the three geo-cytotypes. Conclusion Our results suggest that characterizing gene expression in an invasive species using populations from both its native and introduced range can provide insight into the biology of plant invasion that can complement traditional measurements of plant performance. In addition, these results highlight the importance of using appropriate taxonomic units in ecological genomics investigations.
Broz, Amanda K; Manter, Daniel K; Bowman, Gillianne; Muller-Scharer, Heinz; Vivanco, Jorge M
Assessing the Wildlife Habitat Value of New England Salt Marshes: I. Model and Application
We developed an assessment model to quantify the wildlife habitat value of New England salt marshes based on marsh characteristics and the presence of habitat types that influence habitat use by terrestrial wildlife. Applying the model to12 salt marshes located in Narragansett B...
Dynamics of Intermittent Stream Habitat Regulate Persistence of a Threatened Fish at Multiple Scales
Traditionally, threatened species management has emphasized conservation of individual populations and has assumed that abundance within suitable habitats is pri- marily governed by local environmental factors. However, recent research has revealed that landscape-level processes such as disturbance, dispersal, and habitat patch mosaic structure may also strongly influence local populations. We studied the population and habitat dy- namics of a threatened
Theodore R. Labbe; Kurt D. Fausch
ERIC Educational Resources Information Center
When a preschool teacher unexpectedly found tadpoles in the school's outdoor baby pool, she recognized an unusual opportunity for her students to study pond life up close. By following the tadpoles' development, students learned about frogs, life cycles, habitats. (Contains 1 resource.)
Coffey, Audrey L.; Sterling, Donna R.
Differential influence of the 5-HTTLPR genotype, neuroticism and real-life acute stress exposure on appetite and energy intake.
Stress or negative mood often promotes energy intake and overeating. Since the serotonin transporter-linked polymorphic region (5-HTTLPR) is found to mediate stress vulnerability as well as to influence energy intake, this gene may also influence the negative effects of stress exposure on overeating. Moreover, since stress proneness also reflects cognitive stress vulnerability - as often defined by trait neuroticism - this may additionally predispose for stress-induced overeating. In the present study it was investigated whether the 5-HTTLPR genotype interacted with neuroticism on changes in mood, appetite and energy intake following exposure to a real-life academic examination stressor. In a balanced-experimental design, homozygous S-allele and L-allele carriers (N?=?94) with the lowest and highest neuroticism scores were selected from a large database of 5-HTTLPR genotyped students. Mood, appetite and energy intake were measured before and after a 2-hour academic examination and compared with a control day. Examination influenced appetite for particular sweet snacks differently depending on 5-HTTLPR genotype and neuroticism. S/S compared with L/L subjects reported greater examination stress, and this was accompanied by a more profound post-stress increase in appetite for sweet snacks. Data also revealed a 5-HTTLPR genotype by trait neuroticism interaction on energy intake, regardless of examination. These results consolidate previous assumptions of 5-HTTLPR involvement in stress vulnerability and suggest 5-HTTLPR and neuroticism may influence stress-induced overeating depending on the type of food available. These findings furthermore link previous findings of increased risk for weight gain in S/S-allele carriers, particularly with high scores on trait neuroticism, to increased energy intake. PMID:24630938
Capello, AimÕe E M; Markus, C Rob
Prediction of extinction in plants: interaction of extrinsic threats and life history traits.
The global extinction of species proceeds through the erosion of local populations. Using a 60-year time series of annual sighting records of plant species, we studied the correlates of local extinction risk associated with a risk of species extinction in the Park Grass Experiment where plants received long-term exposure to nutrient enrichment, soil acidification, and reductions in habitat size. We used multivariate linear models to assess how extrinsic threats and life history traits influence extinction risk. We investigated effects of four extrinsic threats (nitrogen enrichment, productivity, acidification, and plot size) as well as 11 life history traits (month of earliest flowering, flowering duration, stress tolerance, ruderalness [plant species' ability to cope with habitat disturbance], plant height, diaspore mass, seed bank, life form, dispersal mode, apomixis [the ability for a species to reproduce asexuall through seeds], and mating system). Extinction risk was not influenced by plant family. All of the 11 life history traits except life form and all threat variables influenced extinction risk but always via interactions which typically involved one threat variable and one life history trait. We detected comparatively few significant interactions between life history traits, and the interacting traits compensated for each other. These results suggest that simple predictions about extinction risk based on species' traits alone will often fail. In contrast, understanding the interactions between extrinsic threats and life history traits will allow us to make more accurate predictions of extinctions. PMID:18027768
FrÕville, HÕlÒne; McConway, Kevin; Dodd, Mike; Silvertown, Jonathan
The Influence of Both Testing Environment and Fillet Radius of the Die Holder on the Rupture Life of Small Punch Creep Tests
NASA Astrophysics Data System (ADS)
The small punch (SP) creep test has been proposed as a semi destructive testing methodology to examine the residual creep life of high temperature components. A series of SP creep tests were conducted on low alloy steel at 600¯C both in air and in high vacuum to investigate the influences of both testing environment and the fillet radius of the lower die holder on the SP creep rupture life. The thickness of the oxide scale on the SP creep specimen in air increased with the test duration, e.g., about 30çm in thickness after a 400 hour exposure. The SP creep rupture life in air reduced to a half of the life in vacuum due to an increase in the actual stress in the specimen and also the coefficient of friction. In addition, the magnitude of the fillet radius at the lower die holder also affected the SP creep rupture life. The influence of the fillet radius on the SP creep rupture life was studied both experimentally and numerically. The SP creep rupture life with a smaller fillet radius of the lower die holder had twice the rupture life compared to that with a larger fillet radius. This effect was also demonstrated by the FE analysis.
Kobayashi, Ken-Ichi; Kaneko, Masahiro; Koyama, Hideo; Stratford, Gavin C.; Tabuchi, Masaaki
Children living with perinatal HIV illness (PHIV+) disproportionately reside in disadvantaged neighborhoods and contend with persistent mental health challenges. This study examined the influences of disadvantaged residential neighborhood on anxiety and depression, and potential resources that buffer against internalizing problems when youths were exposed to neighborhood stressors. Multilevel analysis of 196 PHIV+ and 129 perinatally HIV-exposed but uninfected youth (PHIV?) in New York City found that higher exposure to neighborhood disorder was associated with higher levels of depression and anxiety for PHIV+ and PHIV? youths. Stressful events unrelated to residential neighborhoods significantly mediated the relationship between neighborhood disorder and anxiety and depression. Social problem solving and religiosity did not moderate the relationship between neighborhood disorder and internalizing problems. Our findings highlighted that interventions that attenuate the negative effects of stressful life events were equally critical in addressing the broader impact of disadvantaged neighborhoods on the mental health of youth affected by HIV.
Kang, Ezer; Mellins, Claude A.; Dolezal, Curtis; Elkington, Katherine S.; Abrams, Elaine J.
Habitat Suitability Index Models: Bobcat
A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the bobcat (Felis rufus). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.
Boyle, Katherine A.; Fendley, Timothy T.
Habitat Suitability Index Models: Osprey
A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the osprey (Pandion haliaetus). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.
Vana-Miller, Sandra L.
Spatially Explicit Habitat Characterization, Suitability Analysis, Verification, and Modelling of the Yellow Perch Perca f1avescens (Mitchell 1814) Population in Long Point Bay, Lake Erie
Different approaches were used to characterize, assess, test and model the fish-habitat interactions of yellow perch in Long Point Bay. Chapter 1 describes the methodologies for explicitly characterizing spatial and temporal habitat through mapping and modelling. Chapter 2 connects habitat and ontogenetic niche shifts in perch life history, with the aim of determining suitable habitat availability for the Long Point
Spatially-explicit habitat characterization, suitability analysis, verification, and modelling of the yellow perch Perca flavescens (Mitchell 1814) population in Long Point Bay, Lake Erie
Different approaches were used to characterize, assess, test and model the fish-habitat interactions of yellow perch in Long Point Bay. Chapter 1 describes the methodologies for explicitly characterizing spatial and temporal habitat through mapping and modelling. Chapter 2 connects habitat and ontogenetic niche shifts in perch life history, with the aim of determining suitable habitat availability for the Long Point
Susan Elisabeth Doka
Life cycle and influence of age and feeding on the first mating of Triatoma mazzottii (Hemiptera: Reduviidae).
A cohort of 100 eggs of Triatoma mazzottii Usinger was studied to obtain information on its life cycle. Egg incubation took 24 days; mean duration of 1st, 2nd, 3rd, 4th, and 5th instar nymphs was 27, 36, 39, 46, and 64 days respect