The Sacred Defense, an imperative historical event in Iranian civilization in the preceding century, has nowadays developed into one of the most significant cultural symbols of the society. This has led poets and writers to devote their creations to the formation of artworks with themes and concepts related to this phenomenon. This approach has led to the formation of an exceptional style in the works of such literary figures. A motif is a specific theme, character, or pattern that is repeated in various forms in literature and art. The Sacred Defense poetry, which was formed with the occurrence of the mentioned historical event in the sixties, led to the strengthening of Iranian identity and cultural fundamentals. These widely used cultural motifs represent the poetry of war with its own stylistic features that aid to identify commonalities in thought, culture, values and beliefs of the nation. The issue raised in this paper is to study the effect of this particular style of poetry on the formation and creation of conceptual and visual motifs and its reflection in the posters of the Sacred Defense. This research is accomplished relying on descriptive and analytical methods and also on the collection of library data. The findings suggest that a number of the motifs seen in the poetry of this period are faced with lexical, visual and thematic repetitions; moreover, the thematic section includes concepts such as martyrdom, patriotism, the battle between right and wrong, love, and so on. Studies have shown that the unique motifs related to the poetry of the Sacred Defense bestow an emotional, aesthetic, guiding and prominent function on the content of the poem and the approaches of the audience; consequently, the poets of the Sacred Defense created their most intense artworks by emphasizing the mentioned elements in their poetry. Such concepts have caused the endurance of the values of the Sacred Defense in the history of Iranian literature and its presence for the future Therefore, the adoption of this poetic style has increased the role of conceptual and visual themes in the poetry of the Sacred Defense. The posters of this act are created in order to celebrate and spread the culture of this sacred event and are reproductions of its conceptual and visual motifs in literature. Research aims: 1. To investigative the varieties of motifs and their elements in the poetry of the Sacred Defense. 2. To examine the motifs and elements of the Sacred Defense poetry in poster art. Research questions: 1. What elements do the poems of Sacred Defense use in describing the values and beliefs of such act? 2. What is the reflection of the poems of Holy Defense in the posters of this event?


Recombinant human granulocyte colony-stimulating factor (G-CSF) treatment has been shown to increase average neutrophil counts substantially in patients with childhood-onset cyclic neutropenia (or "cyclic hematopoiesis"), but not to eliminate the cyclic oscillations of neutrophil counts or those of other blood elements (monocytes, platelets, eosinophils, and reticulocytes) that are characteristic of this hematopoietic disorder. Indeed, oscillations of neutrophil counts are amplified during G-CSF treatment. We have compared the effects of recombinant granulocyte-macrophage-CSF (GM-CSF) with those of G-CSF in three patients with this disease (2 men and 1 woman, 17, 30, and 32 years of age). These patients were treated with GM-CSF (2.1 micrograms/kg/day, subcutaneously) for 6 weeks, preceded and followed by 6 to 13 weeks of detailed observation to document changes in the cyclic oscillations of blood neutrophils and other blood elements; two of the patients were subsequently treated with G-CSF (5.0 micrograms/kg/d, subcutaneously) and observed for comparable periods of time. Unlike G-CSF treatment, which increased average neutrophil counts more than 20-fold, GM-CSF increased neutrophil counts only modestly, from 1.6- to 3.9-fold, although eosinophilia of varying prominence was induced in each patient. However, at the same time, GM-CSF treatment dampened or eliminated the multilineage oscillations of circulating blood elements (neutrophils, monocytes, platelets, and/or reticulocytes) in each of the patients. In contrast, G-CSF treatment of the same patients markedly amplified the oscillations of neutrophil counts and caused the cycling of other blood elements (monocytes in particular) to become more distinct. These findings support the conclusion that the distinctive cycling of blood cell production in childhood-onset cyclic neutropenia results from abnormalities in the coordinate regulation of both GM-CSF-responsive, multipotential progenitor cells and G-CSF-responsive, lineage-restricted, neutrophil progenitors.


This thesis studies the methods needed to create a web based application to remotely customize a CAD model. This includes customizing a CAD model by using a graphical user interface to be able to remotely control the inputs to- and outputs from the model in NX, and to get the result sent back to the user. Using CAD systems such as NX requires intensive training, is often a slow process and gives a lot of room for errors. An intuitive, simple user interface will eliminate the need for CAD training or CAD experience. The time used can be reduced by creating smart, parameterizable models that easily can be customized to the user's requirements. Built in rules in the model and the user interface can decrease possibility for errors and help maintain the design intent. By creating a web based solution the user does not need to have a CAD system installed or licensed on its system to update the model and changes can be made on the go. The result of the thesis is a solution where the user can install an application that can connect to a server that can update a CAD model in NX and send the result back to the user. The method used in this solution is presented in the thesis.


K-Ar and fission-track ages from two volcanic ash partings in upper Chickaloon Formation coals range from 53.3 ± 1.5 m.y. to 55.8 ± 1.7 m.y. These ages establish that the Paleocene-Eocene boundary (55 m.y.) occurs within the dated upper part of this formation.


Tantalum pentoxide (Ta(2)O(5)) layers made by ion plating are implanted with a high fluence of keV Ti, Li, and Er ions. The resulting refractive-index profiles are given from the analysis of guided-wave propagation conditions. A comparison with spectrophotometric measurements is presented. All the implanted layers present low losses (extinction coefficient of some 10(-6)) after thermal annealing in air. Ti-implanted layers exhibit an increase in refractive index, whereas Li- and Er-implanted layers present a slight decrease in refractive index. Er-implanted layers present photoluminescent properties.


Segmentation is a low-level processing aimed at the partition of an image in disjoint regions, each one homogeneous with respect to some properties like intensity, texture, shape, etc. Such a task is needed in many high-level processing and applications in such diverse fields as remote-sensing, medical imaging, video coding, and industrial automation, just to name a few.

In this work of thesis, we first deal with the problem of color based image segmentation, that is based on some form of homogeneity in the color/spectral properties of the image, and then move to the more complex task of texture based segmentation, where the aim is to recognize complex structures in the image which are typically non homogeneous in terms of spectral properties.

Concerning color based segmentation, we focus on a specific class of Markov Random Field (MRF) probability models, namely the
Tree-Structured Markov Random Fields (TS-MRF), recently proposed to provide a hierarchical multiscale description of images. Based on such a model, the unsupervised image segmentation is carried out by means of a sequence of nested class splits, where each class is modeled as a local binary MRF.

As a first contribution, we first extend the model to generic tree structures removing the unnecessary binary constraint, and then devise a new TS-MRF unsupervised segmentation technique which improves upon the original algorithm by selecting a better tree structure and eliminating spurious classes. Such results are obtained by using the Mean-Shift procedure to estimate the number of pdf modes at each node, and to obtain a more reliable initial clustering for subsequent MRF optimization. To this end,
we devise a new reliable and fast clustering algorithm based on the Mean-Shift technique, which makes use of a variable-bandwidth strategy based on the k-Nearest Neighbors (k-NN) technique, and is implemented with a speed-up strategy that cuts significantly the computational complexity. Experimental results on synthetic data and real life images from the remote sensing domain prove the potential of the proposed method.

Turning to texture based segmentation, we present a novel multiscale texture model, and a related algorithm for the unsupervised segmentation of color images. Elementary textures are characterized by their spatial interactions with neighboring regions along selected directions. Such interactions are modeled in turn by means of a set of Markov chains, one for each direction, whose parameters are collected in a feature vector that synthetically describes the texture. Based on the feature vectors, the texture are then recursively merged, giving rise to larger and more complex textures, which appear at different scales of observation: accordingly, the model is named Hierarchical Multiple Markov Chain (H-MMC).

The Texture Fragmentation and Reconstruction (TFR) algorithm, addresses the unsupervised segmentation problem based on the H-MMC model. The ``fragmentation'' step allows one to find the elementary textures of the model, while the ``reconstruction'' step defines the hierarchical image segmentation based on a probabilistic measure (texture score)
which takes into account both region scale and inter-region interactions.

The performance of the proposed method was assessed through the Prague segmentation benchmark, based on mosaics of real natural textures, and also tested on real-world natural images from the Berkeley dataset. Finally, an application of the TFR algorithm for the unsupervised segmentation of multiresolution remotely sensed images is proposed, based on the significant presence of textural content in last generation high-resolution satellite images. The obtained results further assess the potential of the proposed method for such real life applications.


St Benedict's inspirational work has been guiding Benedictine monks for fifteen centuries, and the "Penguin Classics" edition of "The Rule of Benedict" is translated with an introduction and notes by Carolinne White. Founder of a monastery at Monte Cassino, between Rome and Naples, in the sixth century, St Benedict intended his "Rule" to be a practical guide to Christian monastic life. Based on the key precepts of humility, obedience and love, its aim is to create a harmonious and efficient religious community in which individuals can make progress in the Christian virtues and gain eternal life. Here, Benedict sets out ideal monastery routines and regulations, from the qualities of a good abbot, the twelve steps to humility and the value of silence to such every day matters as kitchen duties, care of the sick and the suitable punishment for lateness at mealtimes. Benedict's legacy is still strong - his "Rule" remains a source of inspiration and a key work in the history of the Christian church. Carolinne White's accessible translation is accompanied by an introduction discussing Benedict's teachings, what is known of his life, and the influence and spread of his "Rule". Saint Benedict of Nursia (c. 480-543 AD) founded twelve monasteries, the best known of which was his first monastery at Monte Cassino, in Italy. Benedict wrote a set of rules governing his monks, "The Rule of Benedict", one of the more influential documents in Western Civilization. Benedict was canonized a saint in 1220. If you enjoyed "The Rule of Benedict" you might enjoy "St Augustine's Confessions", also available in "Penguin Classics".


Formulas and standards play a needed role in the allocation of library resources, but it is difficult to devise formulas that accurately reflect the various factors that shape a library's needs. This report summarizes the means by which a subcommittee of the Virginia Library Advisory Committee devised a proposed staffing formula for its academic libraries. The subcommittee charged with devising a new formula reviewed past efforts as a means of determining criteria any new formula should meet . Based on this review and on its own research, the committee devised a draft formula , which is discussed.


Chimeric antigen receptor (CAR) T-cell therapy represents an exciting innovation in the treatment of cancer. With the approval of two revolutionary anti-CD19 CAR T-cell therapies (axicabtagene ciloleucel [Yescarta] and tisagenlecleucel [Kymriah]) for relapsed/refractory large B-cell lymphoma, health-care providers must consider how to prepare for the future of cancer care. While these therapies have been shown to provide clinical benefit to many patients, they are associated with a range of adverse events (AEs) that will need to be identified, assessed, and managed. Widespread education of health-care providers, patients, and caregivers will also be essential to ensure the success of this novel treatment. This supplement aims to provide practical information to the advanced practitioner on a number of considerations relating to the implementation and expansion of CAR T-cell therapy, including CAR T-cell biology and mechanism of action, how to identify, grade, and manage treatment-related AEs, as well as best practices for educating patients and caregivers about this type of therapy.


Main task of thesis is to study the effect of Mode dependent Rayleigh damping on System response. Damping ratio for the structure is not constant for all modes and it varies mode wise. In present task different damping models are defined and used to obtain responses for transient system. Obtained responses show that there is considerable effect of mode dependent damping on response of the system. This outcome could be used for investigations of noise, harshness and fatigue.


Restoration of degraded land is an important national goal to achieve Indonesia’s environmental targets. To map both land cover and land degradation, Indonesia needs timely, high quality data and the necessary tools. We have addressed this issue by running a sequence of crowdsourcing campaigns. Our aim is not only to collect the data but to also potentially present a way for citizens to contribute to larger environmental policies and strategies.

Focusing on land cover identification and tree cover change, we planned and ran a set of  pilot crowdsourcing campaigns in two provinces in Indonesia. We analysed the data from these pilot campaigns, and then used the insights obtained in the subsequent crowdsourcing campaign on land cover identification, upscaled to national level, which is currently ongoing. The campaigns were run using a mobile application developed as part of the RESTORE+ project. Through this application, we presented volunteers with simple microtasks by showing them satellite images and asking a simple yes/no question as to whether the image shows a particular land cover class. The application implemented a scoring system, which additionally performs a quality control of the data contributed by the crowd, and users competed with each other to classify the satellite images displayed by the application. 692 volunteers have actively engaged in the pilot crowdsourcing campaigns and have contributed more than 2.5 million satellite image interpretations.

Based on the insights from the pilot campaigns, as well as an expert consultation session in Indonesia, the crowdsourcing application was modified to ensure, first, a uniform number of interpretations across the images, and secondly, higher quality data by allowing users to focus on geographical areas familiar to them, as well as to see the larger area surrounding the target sample.

We analyzed the data collected and will present issues regarding data quality, comparing the accuracy of the contributions from the volunteers with the accuracy of the data collected by a set of experts. We show that a citizen science approach is promising and can complement scientific analyses and can provide potential inputs to policies on landscape restoration. A crowdsourcing approach to image interpretation can also help to shorten the time needed for data collection, making the process more cost-effective. In addition, the collective ownership of the results ensures their legitimacy and increases the chances of data acceptance.

We also focus on transparency and the importance of open data. We present how we have made data generated by the crowd accessible in order to empower citizens in exploring and process the data further, thereby actively participating in environmental decision making.


Geographical clusters have been analysed from several points of view. One issue has not been addressed, however, and that is how these systems succeed in reproducing themselves over time and evolving. The paper attempts to bridge this gap with reference to Marshallian industrial districts, that belong to the broader category of clusters. Specifically, a conceptual framework has been developed based on three factors influencing the Marshallian industrial districts' reproducibility, i.e., the community factor, the network factor and the entrepreneurship factor. Entrepreneurship is the factor that gives the model its originality. It was virtually left untouched by the Marshallian scholars of industrial districts. Taking account of entrepreneurship, it becomes possible to explain the fall of the Marshallian model in the globalisation era.


Infectious diseases currently pose a great threat to global biodiversity. One of the most alarming
wildlife disease to date is chytridiomycosis, a fatal disease of amphibians caused by the pathogen
Batrachochytrium dendrobatidis. Chytridiomycosis has been implicated in mass mortalities,
population declines, and local and global extinctions of many species of amphibians around the world.
However, while some species have been severely affected by the disease, other, sympatric species
remain unaffected. One reason why some species decline from chytridiomycosis and others do not
may be interspecific differences in behaviour, which may affect the probabilities of acquiring and
succumbing to infections. Host behaviour can either facilitate or hinder pathogen transmission, and
transmission rates in the field are likely to vary among species according the frequency of factors such
as physical contact between frogs, contact with infected water, and contact with environmental
substrates that may serve as reservoirs. Similarly, the thermal and hydric environments experienced by
frogs can strongly affect their susceptibility to chytridiomycosis, so some interspecific differences in
the effects of the disease may also be caused by differences in microenvironment use among species.
I examined the potential effects of behaviour on the susceptibility of different host species to
declines caused by chytridiomycosis by tracking three species of stream-breeding frogs in northern
Queensland, Australia. The species historically co-occurred at many sites in the Wet Tropics, but high
elevation (> 400 m) populations of two species declined to differing degrees in association with
outbreaks of chytridiomycosis in recent decades, while low elevation populations remained apparently
unaffected. The waterfall frog Litoria nannotis, declined to local extinction at all known high
elevation sites. All studied populations of the green-eyed tree frog Litoria genimaculata at high
elevation sites declined to low numbers and then recovered. The third species, the stoney creek frog
Litoria lesueuri, is not known to have experienced population declines even at high elevations.
I used radio telemetry and harmonic direction finding to track frogs at five sites. Surveys
lasted 16 days and were conducted in both the cool/dry season and the warm/wet season. The location
of each frog was determined once during the day and once at night over the duration of the survey
period. At each location, I recorded contact with other frogs, stream water, and other environmental
substrates, its three-dimensional position, movement, habitat type, and body temperature. Retreat sites
of L. lesueuri and L. nannotis were also sampled for B. dendrobatidis. Harmonic direction finding
obtained fewer fixes on frogs but measures of movement and habitat use did not differ significantly
between techniques. In total, 117 frogs were tracked: 28 L. nannotis, 27 L. genimaculata and 62 L.
lesueuri. Frequency of contact with other frogs and with water was highest in L. nannotis,
intermediate in L. genimaculata, and lowest in L. lesueuri. Environmental substrate use differed
among species, and B. dendrobatidis was not detected at retreat sites. Movement and habitat use also
differed significantly among species. Litoria lesueuri moved more frequently and greater distances
and was often located away from streams, moving between intact rainforest and highly disturbed
environments. Litoria genimaculata moved less frequently and shorter distances, and was more
restricted to stream environments, occasionally moved large distances along and between streams, but
was never located outside of intact rainforest. Litoria nannotis remained in streams during the day, did
not move large distances along or move between streams, and was always located within intact
rainforest.
In addition to tracking data, I designed, tested, and deployed novel physical models to record
the thermal conditions experienced by frogs, regardless of cutaneous resistance to water-loss. These
models were placed in species-specific diurnal retreat sites; providing profiles integrated over time of
the thermal and hydric regimes of the microenvironments experienced by each species.
Microenvironmental conditions experienced by frogs differed markedly among species and
seasons. Retreat sites of the most susceptible species, L. nannotis, were almost always within the
thermal optimum and never above the thermal tolerance of B. dendrobatidis, while retreat sites of the
least susceptible species, L. lesueuri, were commonly above the thermal optimum and thermal
tolerance of B. dendrobatidis. Hydric conditions were most suitable for B. dendrobatidis growth at L.
nannotis retreat sites.
Species-specific differences in behaviour are therefore likely to have large implications for the
susceptibility of species to decline due to chytridiomycosis. This thesis provides the first empirical
confirmation that species-specific differences in behaviour are likely to affect the susceptibility in
nature of amphibians to chytridiomycosis. The behaviour of the species most susceptible to B.
dendrobatidis related declines was the most favourable for the transmission, growth and development
of B. dendrobatidis, while the behaviour of the species least susceptible to B. dendrobatidis related
declines had the least favourable for its transmission, growth and development. Species-specific
differences in the behaviour of frogs in the field may also explain why infected individuals of some
species experience rapid mortality in the laboratory, yet are able to carry infections for extended
periods in the field. Temporal and spatial variation in microenvironments available to and used by
frogs may also explain variation in infection prevalence and host mortality. Information on amphibian
behaviour and microenvironmental use may be useful in evaluating the susceptibility to declines
caused by chytridiomycosis in species that presently occur in areas without B. dendrobatidis.


Adults' expectations are often biased by their desires, a phenomenon known as the desirability bias. The current study was the first to investigate the desirability bias in 4- and 5-year-old children and adults. Participants predicted whether a critical card would be drawn from decks containing 10 cards. Decks contained one of five different ratios of critical to noncritical cards (1:9, 4:6, 5:5, 6:4, 9:1). For some decks, drawing a critical card resulted in gaining a reward and in other decks, it resulted in a loss. Results showed that children, like adults, exhibited a desirability bias by predicting critical cards more often when they were associated with a gain than when they were associated with a loss. Furthermore, children showed a stronger desirability bias than adults for both gains and losses. Children, but not adults, showed a desirability bias for potential losses. Adults tended to use a strategy that minimized losses by predicting an undesirable outcome to occur when there was a potential loss at stake. Future research should attempt to measure the desirability bias in infants, as well as older adults, in order to better understand the developmental trajectory of the bias throughout the lifespan.


A multi-channel microwave interferometer can measure plasma density radial profiles in a single plasma shot. It has six observing channels for measuring the radial electron line integrated density profile. The multi-channel microwave interferometer has been reconstructed for improving the signal intensity increase. We set a spherical mirror between the probe beam transmission horn and the injection port window of the multi-channel microwave interferometer. The insertion of spherical mirror makes signal intensity in all measuring channels to be improved. Then, we can successfully obtain the radial electron density profile in a single plasma shot.


Climate warming in northeastern Siberia may induce thaw-mobilization of the organic carbon (OC) now held in permafrost. This study investigated the composition of terrestrial OC exported to Arctic coastal waters to both obtain a natural integration of terrestrial permafrost OC release and to further understand the fate of released carbon in the extensive Siberian Shelf Seas. Application of a variety of elemental, molecular and isotopic ( δ13C and114C) analyses of both surface water suspended particulate matter and underlying surface sediments along a 500 km transect from Kolyma River mouth to the mid-shelf of the East Siberian Sea yielded information on the sources, degradation status and transport processes of thaw-mobilized soil OC. A three end-member dual-carbon-isotopic mixing model was applied to deduce the relative contributions from riverine, coastal erosion and marine sources. The mixing model was solved numerically using Monte Carlo simulations to obtain a fair representation of the uncertainties of both end-member composition and the end results. Riverine OC contributions to sediment OC decrease with increasing distance offshore (35 ±15 to 13±9%), whereas coastal erosion OC exhibits a constantly high contribution (51± 11 to 60± 12%) and marine OC increases offshore (9±7 to 36±10%). We attribute the remarkably strong imprint of OC from coastal erosion, extending up to ∼500 km from the coast, to efficient offshoreward transport in these shallow waters presumably through both the benthic Correspondence to:̈ O. Gustafsson (email@example.com) boundary layer and ice-rafting. There are also indications of simultaneous selective preservation of erosion OC compared to riverine OC. Molecular degradation proxies and radiocarbon contents indicated a degraded but young ( 114C ca. −60‰ or ca. 50014C years) terrestrial OC pool in surface water particulate matter, underlain by a less degraded but old (114C ca.−500‰ or ca. 550014C years) terrestrial OC pool in bottom sediments. We suggest that the terrestrial OC fraction in surface water particulate matter is mainly derived from surface soil and recent vegetation fluvially released as buoyant organic-rich aggregates (e.g., humics), which are subjected to extensive processing during coastal transport. In contrast, terrestrial OC in the underlying sediments is postulated to originate predominantly from erosion of mineral-rich Pleistocene coasts (i.e., yedoma) and inland mineral soils. Sorptive association of this organic matter with mineral particles protects the OC from remineralization and also promotes rapid settling (ballasting) of the OC. Our findings corroborate recent studies by indicating that different Arctic surface soil OC pools exhibit distinguishing susceptibilities to degradation in coastal waters. Consequently, the general postulation of a positive feedback to global warming from degradation of permafrost carbon may be both attenuated (by reburial of one portion) and geographically displaced (degradation of released terrestrial permafrost OC far out over the Arctic shelf seas). Published by Copernicus Publications on behalf of the European Geosciences Union. 3154 J. E. Vonk et al.: Molecular and radiocarbon constraints on sources and degradation of terrestrial organic carbon


Predictions of the mechanical properties of a densely packed granular material so far
have been quite inaccurate. Many of the phenomena observed by such a material leave a
lot of unanswered questions. For example the stiffness of a sample under a strain path is
poorly predicted by the most recent theoretical work. Part of the difficulty of a granular
material is the interplay between discrete and continuous measures. For any sample of a
practical scale, the size and numbers of grains involved makes consideration of each
individual grain a near impossible process. So on the whole, continuum measures and
theories have been used to try to describe the material behaviour without
acknowledgement of the particulate constituents. However, that the mechanics of the
material as a whole is dependent on the inter-particle forces is undeniable. These inter-
particle forces work at the level of the individual particle where discrete measures such
as force and displacements should be used. So how can practical, continuum measures
be constructed from discrete constituents? This thesis provides the theoretical means to
traverse from the discrete constituents to continuum measures. A key feature is the
formalisation of a mesodomain, which is the unit of a granular material where the
continuum and discrete regimes meet. Use is made of the formulation of a
heterogeneous material to describe this mesodomain and it is shown how material
properties can be scaled up from the mesoscale to the size of a sample of granular
material. Work external to this project provides a method for describing the mechanics
within the mesodomain. This is used to calculate the values of important tensors that
represent the fabric of the mesodomain.


The effects of Sino-US and Sino-EU safeguard agreements on US, China and world cotton and textile sectors are investigated using a partial equilibrium model. The effects are compared to a free trade scenario under the provisions of the Agreement on Textiles and Clothing (ATC). The two agreements capping Chinese textile exports would decrease China's textile and apparel exports, production and domestic consumption by an average 1.57 percent, 0.63 percent and, 0.32 percent respectively. The safeguard agreements cause an increase in the U.S. cotton textile price index and a slight decrease in U.S. net textile imports and textile consumption. The agreements cause a decrease in the world cotton price and the quantity of cotton traded, but these trends reverse at safeguard expiration. The results generally support the view that the safeguard agreements forestall the effects of free trade in textiles and apparel rather than creating long lasting shifts in the textile trade.


The associations between storm events, urban runoff, and coastal water quality have not been well investigated. A temporal and spatial analysis of 2 years of data was conducted to determine associations between urban river discharge and indicator bacteria levels for Southern California beaches and evaluate the contribution of anomalous precipitation to the association. Data show beaches next to rivers had the highest bacterial levels in both wet and dry seasons. Bacterial levels rose substantially across all sites during wet months, and river discharge and bacterial levels were all highest during the winter with the most rainfall. Precipitation was significantly associated (Spearman rank bivariate correlation, P < 0.01) with water discharged from the rivers. River discharge was significantly associated with bacterial levels at 20 out of 22 beaches, with the strongest associations at sites next to rivers. The results indicate that urban river discharge is a primary source of Southern California's coastal water pollution and, as a result, swimming at beaches near rivers may pose a significant public health risk. The strong association found between precipitation and water pollution may be relevant to studies of potential health effects associated with climate change.


Beach-cast kelp (principally Laminaria spp.), known as macroalgal wrack, has been suggested as a feedstock for biofuel. However, to be extracted sustainably it is necessary to understand its ecological role and predict the impacts of its removal. Field-based observations combined with food web modelling were used to predict the ecosystem effects of removing wrack from beaches of the Uists, western Scotland. Beaches with wrack were associated with enriched benthic infauna (polychaetes) on the lower shore, and wrack mounds supported abundant macroinvertebrates (mainly Diptera larvae and oligochaetes); with some of the highest biomasses reported globally for beaches. These fauna are valuable prey to shorebirds, as demonstrated by a strong positive relationship (R 2 = 0.82) between wader abundances and the percentage cover of wrack on beaches. Inshore, drifting macroalgae was associated with elevated abundances of detritivorous hyperbenthic fauna (mysids, isopods and gammarid amphipods). In addition, the volume of drifting macroalgae inshore was a significant predictor (along with physical beach characteristics) for the abundance of decapods and fish. Food web models and network analysis indicated that beaches which accumulate wrack had a greater diversity of trophic links and more functional redundancy, making their food webs more resilient to perturbations. Such perturbations may include stressors induced by climate change, such as increased erosion of sediments during storms, elevated atmospheric and sea surface temperatures and elevated CO2 concentrations. Model simulations of wrack harvesting predicted an immediate decline in primary consumers in direct proportion to the quantity of wrack removed, and a slow decline in shorebirds in response to reduced prey. Primary consumers were predicted to recover to their pre-harvest biomasses within 1 to 2 years regardless of harvesting intensity, but recovery times for shorebirds were an order of magnitude longer, and increased with harvesting intensity. Harvesting more than 50% wrack predicted a 'collapse' in wader populations within 25 years, and recovery times of 45-60 years were estimated if >70% wrack was removed. The findings of this thesis suggest wrack provides essential food and shelter to coastal fauna, and its large-scale removal would have significant negative impacts to the ecosystem functioning.


Autonomous navigation by a mobile robot through L natural, unstructured terrain is one of the premier k challenges in field robotics. Tremendous advances V in autonomous navigation have been made recently in field robotics. Machine learning has played an increasingly important role in these advances. The Defense Advanced Research Projects Agency (DARPA) UGCV-Perceptor Integration (UPI) program was conceived to take a fresh approach to all aspects of autonomous outdoor mobile robot design, from vehicle design to the design of perception and control systems with the goal of achieving a leap in performance to enable the next generation of robotic applications in commercial, industrial, and military applications. The essential problem addressed by the UPI program is to enable safe autonomous traverse of a robot from Point A to Point B in the least time possible given a series of waypoints in complex, unstructured terrain separated by 0.2-2 km. To accomplish this goal, machine learning techniques were heavily used to provide robust and adaptive performance, while simultaneously reducing the required development and deployment time. This article describes the autonomous system, Crusher, developed for the UPI program and the learning approaches that aided in its successful performance.


The U.S. Environmental Protection Agency (EPA) continues to move ahead with regulation of greenhouse gas emissions under the Clean Air Act (CAA). Previous work has indicated that basic forms of compliance flexibility—trading—appear to be legally permissible under the relevant part (Section 111) of the CAA. This paper takes a close look at more expansive and ambitious types of flexibility: trading between different kinds of sources, biomass co-firing, and, above all, offsets. It concludes that most types of such extended flexibility are either legally incompatible with the CAA, or so legally problematic that EPA is unlikely to adopt them. This has important implications for both the costs of CAA climate policy and the level of environmental benefits that are achievable. It also creates tension between CAA climate policy and state-level policies, such as California's, that aim to include various forms of extended flexibility.


The study reported in this thesis is a contribution towards the understanding on the relationship of Electro Discharge Machining (EDM) parameters in machining of tool steel. Some of the main parameters controlling material removal rate (MRR) in EDM, namely supply current, pulse on/off duration and electrode size with electrode wear rate (EWR) are studied and their effects on the machinability factors (MRR and EWR) are evaluated. The surface finish in term of surface texture, which determined by the roughness measurement on the machined surface (Ra) is also studied. Further, volumetric wear (VW) as the three-dimensional analysis among MRR, EWR and machining time or pulse on/off duration is analyzed. In the experiment using the die-sinking EDM, tool steel and copper were selected as the workpiece and electrode, respectively. Three sizes of copper electrode were used: diameter of 5 mm, 10 mm and 15 mm and two experimental setups were prepared. In setup-I, those electrodes were used to produce blind hole machining features at supply currents of 3A and 6A for machining time from 5 to 20 minutes, while pulse on/off duration was kept
constant. In setup-2, machining time was kept constant, supply currents were also 3A and 6A but pulse on/off durations were varied from 6 to 12 J.1S. From the evaluation
of MRR, EWR, surface roughness and VW, the results show that the electrode with diameter of 15 mm gives the best performance at all supply currents, machining time and pulse on/ofT durations. The values of MRR and EWR increase as the increasing of machining time, supply current and pulse on/off duration. Surface roughness has no relationship with machining time. In contrast, it has a close relationship with pulse on/off duration where the higher the pulse on/off duration the higher is the magnitude of surface roughness.


The chalcogens selenium (Se) and tellurium (Te) are rare earth elements, which are mainly present in the environment as toxic oxyanions, due to the anthropogenic activities. Thus, the increased presence of these chalcogen-species in the environment and the contamination of wastewaters nearby processing facilities led to the necessity in developing remediation strategies aimed to detoxify waters, soils and sediments. Among the different decontamination approaches, those based on the ability of microorganisms to bioaccumulate, biomethylate or bioconvert Seand/or Te-oxyanions are considered the leading strategy for achieving a safe and eco-friendly bioremediation of polluted sites. Recently, several technologies based on the use of bacterial pure cultures, bacterial biofilms or microbial consortia grown in reactors with different configurations have been explored for Seand Te-decontamination purposes. Further, the majority of microorganisms able to process chalcogen-oxyanions have been described to generate valuable Seand/or Te-nanomaterials as end-products of their bioconversion, whose potential applications in biomedicine, optoelectronics and environmental engineering are still under investigation. Here, the occurrence, the use and the toxicity of Seand Te-compounds will be briefly overviewed, while the microbial mechanisms of chalcogen-oxyanions bioprocessing, as well as the microbialbased strategies used for bioremediation approaches will be extensively described.


Abstract The development of new psychotherapies such as Eye Movement Desensitization and Reprocessing (EDMR) has led to numerous fresh approaches to both the treatment of trauma and to the understanding of underlying psychopathology. A unified view appears to be slowly emerging in an attempt to corroborate clinical practice with neurobiological data. This article attempts to demonstrate links between alternate psychotherapies by highlighting what appears to be an invariant among these approaches, namely "letting go." This concept refers to a psycho-physical dynamic that combines psychological dissociation and reassociation, as well as the body's vagotonic mechanisms. Following an explanation of this process, it is demonstrated how letting go can manifest itself physiologically and why this may be significant in the study of trauma.


In the field of Test & Control Instrument , multi-channel signal sources are needed as the excitation in the electrical parameters measurement. This paper presents a realization method of multiplexed signal source which combined the advantages of DDS principle with high speed programmable logic device FPGA, fully reflect the characteristics of fast switching frequency, high precision with DDS technology, and abundant FPGA logic resources. This design realized the optimization of DDS resources primarily through FPGA, made use of timing multi-threaded design ROM shared access, innovated an adjustable amplitude method, namely, applied FPGA internal procedures to modulate the normalized waveform sampling digital.


Although missing data are prevalent in applications, existing implementations of Gaussian mixture models (GMMs) require complete data. Standard practice is to perform complete case analysis or imputation prior to model fitting. Both approaches have serious drawbacks, potentially resulting in biased and unstable parameter estimates. Here we present MGMM, an R package for fitting GMMs in the presence of missing data. Using three case studies on real and simulated data sets, we demonstrate that, when the underlying distribution is near-to a GMM, MGMM is more effective at recovering the true cluster assignments than state of the art imputation followed by standard GMM. Moreover, MGMM provides an accurate assessment of cluster assignment uncertainty even when the generative distribution is not a GMM. This assessment may be used to identify unassignable observations. MGMM is available as an R package on CRAN: https://CRAN.R-project.org/package=MGMM.


THE LAUNCH OF THE National Disability Insurance Scheme (NDIS) in Australia announced changes to the ways people with disabilities and families access services. These changes cover delivery of early childhood early intervention to families with infants and young children with disabilities. In July 2013, the NDIS was rolled out nationally in three pilot sites. This funded phenomenological study was conducted in one pilot rollout site with administrators from two agencies delivering such services. Analysis of the data identified factors that challenged professional practice and personal philosophy. The findings suggest that the long-term financial viability of community agencies is at risk. A crucial dilemma emerged concerning parent choice: to what extent does a 'user pay' system impose limitations to services being delivered in a family centred way?


1. We sampled a set of 93 lakes situated in the floodplains of the lower River Rhine in search for morphometric and other factors that explain their variation in clarity. 2. Lakes with a drop in summer water level were less turbid at the time of sampling, mainly because of a lower concentration of inorganic suspended solids (ISS). 3. We also found that older lakes were more turbid than younger lakes and that this was largely because of an increase in phytoplankton. 4. Water clarity was positively related to lake depth and the presence of vegetation. 5. Model calculations indicated that the underwater light climate was strongly affected by chlorophyll and ISS, the latter being the dominant factor affecting Secchi depth. Dissolved organic carbon (DOC) was less important. 6. The high concentration of ISS suggests that intensive resuspension occurs in most of the lakes. Using a simple wave model, and assuming that vegetation protects sediments against resuspension, we could eliminate wind resuspension as an important process in 90% of the lakes, leaving resuspension by benthivorous fish as probably the most important factor determining transparency. 7. Chlorophyll a concentration showed a strong positive correlation to ISS concentration, suggesting that resuspension may also have a positive effect on phytoplankton biomass in these lakes. 8. In conclusion, in-lake processes, rather than river dynamics, seem to be driving the turbidity of floodplain lakes along the lower River Rhine.


Total chlorophyll (Cab) content of a forest canopy is used as indicator for the current state of a forest stand, and also as an input for various physiological vegetation models (i.e. models of photosynthesis, evapo-transpiration, etc.). Recent hyperspectral remote sensing allows retrieving the Cab concentration of vegetation using the appropriate optical indices, and/or by means of biochemical information, scaled up from leaf to canopy level within radiative transfer (RT) models. Plenty of chlorophyll optical indices can be found in the literature for the leaf level, nevertheless, only some of them were proposed for a complex vegetation canopy like a forest stand. A robust chlorophyll optical index at the canopy level should be driven by the Cab concentration without negative influence of other factors represented by soil background or understory, canopy closure, canopy structure (e.g. leaf area index (LAI), clumping of leaves), etc. A new optical index named Area under curve Normalised to Maximal Band depth between 650725 nm (ANMB650-725) is proposed to estimate the chlorophyll content of a Norway spruce (Picea abies, /L./ Karst.) crown. This index was designed to exploit modifications of a vegetation reflectance signature invoked within the red-edge wavelengths mainly by the changes in leaf chlorophyll content. ANMB650-725 is based on the reflectance continuum removal of the chlorophyll absorption feature between wavelengths of 650-725 nm. Suitability of the index and sensitivity on disturbing factors was tested using a 3D Discrete Anisotropic Radiative Transfer (DART) model coupled with a leaf radiative transfer model PROSPECT adjusted for spruce needles. The results of the ANMB650-725 abilities within a coniferous forest canopy were compared with the performance of the chlorophyll indices ratio TCARI/OSAVI. Test results, carried out with the DART model simulating hyperspectral data with 0.9 m pixel size, showed a strong linear regression of the ANMB650-725 on spruce crown Cab concentration (R 2 =0.9798) and its quite strong resistance against varying canopy structural features such as LAI and canopy closure. The root mean square error (RMSE) between real and the ANMB650-725 estimated Cab concentrations was only 9.53 µg/cm 2 while the RMSE generated from prediction of the TCARI/OSAVI was two times higher (18.83 µg/cm 2 ). Chlorophyll retrieval using the ANMB650-725 index remained stable also after introduction of two reflectance signal disturbing features: a) 20% of the spectral information of epiphytic lichen (Pseudevernia sp.) regularly distributed within the spruce canopy, and b) simulation of the sensor noise (computed for a signal to noise ratio equal to 5). RMSE of predicted Cab concentration after the introduction of lichens appeared to be 10.51 µg/cm 2 and the combined influence of lichen presence and sensor noise in the image caused an increase of the RMSE to 12.13 µg/cm 2 .


Identification of harpacticoid copepods sampled with a multiple corer during DIVA 1 expedition of RV METEOR (cruise M 48/1) from the Angola Basin yielded the enormous number of 684 species out of 2222 adult specimens. The species number is comparable to that provided by BAGULEY et al. (2006) for the Northern Gulf of Mexico deep-sea (696 species out of 3654 adults). However, BAGULEY et al. (2006) sampled 43 stations scattered over hundreds of kilometres, while we analysed data from only two stations 600 kilometres apart from each other.
Regarding the two stations from the Angola Basin, significant diversity differences were detected, the Northern station # 346 being far more diverse than the Southern station # 325 with respect to species density.


Laser produced from active medium is normally in continuous mode. The beam can be modulated by inserting switching mechanism. An electro-optic mechanism is one of the techniques used to alter the operation of laser beam from continuous into pulse mode. Hence, the objective of this project is to develop an optical switch system by using Pockels effect. Helium-Neon (He-Ne) laser was used as continuous light source in the project. Calcite and quartz crystals were employed as natural birefringent materials. While a synthetic birefringent material, lithium niobate was used as a Pockels cell. The lithium niobate crystal can become birefringent only through the application of electric field. Therefore, several pulse generators were developed and used to trigger an electrooptic driver to electrify the lithium niobate crystal. A Pockels cell house was designed and fabricated by using perspex. The Pockels cell house was completed with electrodes. The performance of the fabricated Pockels cell was compared to the commercial Pockels cell. Both of the Pockels cells exhibited similar characteristic, whereby the linear polarization state of laser light was turned into circular state when it entered the electrified Pockels cells with a : b ratio of 1.0 : 1.0 (2 kV and 3 kV voltage applied) and 1.1 : 1.0 (4 kV voltage applied). This converts the continuous He-Ne beam into pulse mode. The generation of the laser pulse can be operated either in a single or repetitive mode. It depends on the frequency of the pulse generator. The amplitude of the produced laser pulse was increased by increasing the voltage supplied to electrify the lithium niobate crystal. The amplitude of the produced laser pulse by using transverse Pockels cell was 500 mV, 700 mV and 1000 mV at 2 kV, 3 kV and 4 kV applied voltage. While the result obtained by using commercial Pockels cell was 700 mV, 900mV and 1200 mV.


This article aims to further the current discussions in organizational studies about the construction of organizational legitimacy. We examine the influence of mass self-communication—in particular, evaluative judgments, such as product reviews, made by citizens in online communities—on the construction of organizational legitimacy. We chose an interdisciplinary approach in which we evaluated 177 studies from the field of organizational and communication science, relying on organizational legitimacy and mass self-communication as combined theoretical backbones. Our analysis revealed three sensitizing concepts: (1) community-mediated constituency, (2) audience engagement dilemmas, and (3) influencer-generated legitimacy. Based on these sensitizing concepts, we discuss outside-in (audience- or influencer-driven) and inside-out (company-driven) perspectives on the construction of organizational legitimacy.


The impact of stress-driven structural transitions and of film strain on the magnetic properties of nm ferromagnetic films is discussed. The stress-induced bending of film-substrate composites is analysed to derive information on film stress due to lattice mismatch or due to surface-stress effects. The magneto-elastic coupling in epitaxial films is determined directly from the magnetostrictive bending of the substrate. The combination of stress measurements with magnetic investigations by the magneto-optical Kerr effect (MOKE) reveals the modification of the magnetic anisotropy by film stress. Stress-strain relations are derived for various epitaxial orientations to facilitate the analysis of the substrate curvature. Biaxial film stress and magneto-elastic coupling coefficients are measured in epitaxial Fe films in situ on W single-crystal substrates. Tremendous film stress of more than 10 GPa is measured in pseudomorphic Fe layers, and the important role of film stress as a driving force for the formation of misfit distortions and for inducing changes of the growth mode in monolayer thin films is presented. The direct measurement of the magneto-elastic coupling in epitaxial films proves that the magnitude and sign of the magneto-elastic coupling deviate from the respective bulk value. Even a small film strain of order 0.1% is found to induce a significant change of the effective magneto-elastic coupling coefficient. This peculiar behaviour is ascribed to a second-order strain dependence of the magneto-elastic energy density, in contrast to the linear strain dependence that is valid for bulk samples.


Viral hepatitis is an acute or chronic neglected disease that affects predominantly the liver. This study aimed to determine the sero prevalence and risk factors for viral hepatitis and HCV genotypes in urban areas of Yemen. In a prospective, cross-sectional, analytical and community-based study and following informed consent, 501 volunteers were randomly recruited. Demographic and clinical data was collected. Screening for HBV, HDV and HCV was carried out using ELISA. HBV/HCV viral loads and HCV genotyping were carried out using COBAS TaqMan48 Analyzer (Roche Diagnostics Gmbh, Germany). The mean age of study population was 25.9±10.6 years with a male: female ratio of 1. HBV sero prevalence was similar in Sana'a, Taiz and Aden (p = 0.2). Evidence of past HBV infection was significantly high in Aden and Taiz (14.1 and 18.8%, respectively) compared to Sana'a (5.4%) (p = 0.002). HBV DNA Viral loads were widely variable (1350 and 6320 copies mLG). HCV sero prevalence was low and not significantly different in the study cities (p = 0.4). HCV Viral loads were widely variable between samples (657300-1630000 copies mLG). HCV Genotypes 4 and 1a were the most predominant genotypes. Blood transfusion (19%), renal dialysis (18.6%), history of cupping (18.1%), surgical operation (17.4%) and dental treatment (15.4%) were the most common risk factors for HBV and HCV sero reactivity. In conclusion, HBV sero prevalence is variable among different geographical areas in Yemen. Past exposure to HBV is high. Blood transfusion and contaminated surgical instruments are important infection risks for viral hepatitis. HCV genotypes 4 and 1a are the most prevalent.


OBJECTIVE
To compare stapled haemorrhoidectomy with open diathermy haemorrhoidectomy in Chinese patients with respect to the postoperative pain, symptom control, and manometric alterations.

DESIGN
Prospective randomised controlled trial.

SETTING
A regional general surgical unit, Hong Kong.

PATIENTS
Twenty-four patients with second- or third-degree haemorrhoids or who have had failed medical treatment.

INTERVENTION
Open diathermy haemorrhoidectomy or stapled haemorrhoidectomy.

MAIN OUTCOME MEASURES
Structured questionnaire for symptoms, anorectal manometry, transrectal ultrasound, and postoperative pain.

RESULTS
Stapled haemorrhoidectomy compared with open diathermy haemorrhoidectomy resulted in similar postoperative pain and drug requirements. Postoperative control of prolapse symptoms was significantly better with open diathermy haemorrhoidectomy than with stapled. The control of other symptoms was similar with regard to bleeding, pain, pruritus, and incontinence scores. Anorectal manometry showed a decrease in the maximum resting pressure and maximum squeeze pressure in both groups, but the decrease was only significant in the stapled haemorrhoidectomy group.

CONCLUSIONS
Stapled haemorrhoidectomy is as effective as conventional haemorrhoidectomy for the treatment of haemorrhoids, but with the exception of skin tag prolapse. There is a need for long-term follow-up for the changes in manometric parameters after haemorrhoidectomy.


Stretching exercises are commonly prescribed before training sessions and competitions aiming at performance improvement and reduction of injury risk. However, many studies have shown that muscular torque production capacity may be reduced just after stretching. Therefore, the stretching duration necessary to produce these acute force deficits, as well as the physiological mechanisms responsible for them are relevant issues. The aim of this work was to investigate the acute effects of static stretching protocols with different durations on the isokinetic hamstrings performance. Thirty-six young male volunteers took part in this study and were evenly distributed in three groups: E1, E2 and C. All of them performed a systemic warm-up for five minutes and went through active range of motion (AROM) of hip flexion and isokinetic assessment. The participants of groups E1 and E2 performed static stretching protocols of 180s (4 x 45s) and 360s (8 x 45s) respectively, and were evaluated again. The participants of group C (control) remained at rest for a period of 270s and were evaluated again. The variables considered were AROM, peak torque, maximum work and total work. Both stretching protocols were able to produce increase in AROM; however, only the longest protocol produced deficits on peak torque and maximum work. Total work was not affected by any of the stretching protocols, though. Therefore, these results suggest that changes in muscular stiffness, that caused AROM gain, would not be responsible alone for the force deficits. Moreover, one can conclude that the maximum muscular strength depends on the stretching duration, but the muscular work along some repetitions of an exercise does not.


In this paper we present a novel gait analysis technique which can directly be used to synthesize gaits for a broad class of mechanical systems. We build upon prior work in locomotion mechanics, however we take a different approach to generate gaits that yield absolute motion of the mechanical system. We present a systematic analysis to control all parameters of a proposed type of gait which eliminates the need for intuition and guesswork as was required in the prior work. The main contribution of the paper is relating position change or motion in the ber space to a volume integral bounded by closed curves on a two dimensional manifold embedded in the base space or shape space of the robot. Not only does our method remove the restriction of using sinusoidal gaits as was the case in the prior work but it also allows for generating optimal gaits by solving a variational problem rather than solving a dynamic programming problem as was the case in the prior work.


Many U.S. nursing homes have serious quality problems, in part, because of inadequate levels of nurse staffing. This commentary focuses on two issues. First, there is a need for higher minimum nurse staffing standards for U.S. nursing homes based on multiple research studies showing a positive relationship between nursing home quality and staffing and the benefits of implementing higher minimum staffing standards. Studies have identified the minimum staffing levels necessary to provide care consistent with the federal regulations, but many U.S. facilities have dangerously low staffing. Second, the barriers to staffing reform are discussed. These include economic concerns about costs and a focus on financial incentives. The enforcement of existing staffing standards has been weak, and strong nursing home industry political opposition has limited efforts to establish higher standards. Researchers should study the ways to improve staffing standards and new payment, regulatory, and political strategies to improve nursing home staffing and quality.


The availability of P fertilizer to plants is decreased in acid soils due to phosphate sorption onto solid-phase binding sites. A combination of solution analysis, micro-x-ray fluorescence (μ-XRF) and micro-x-ray absorption near edge structure (μ-XANES) spectroscopy were used to investigate the degree to which sorption of fertilizer P is determined by reaction with Al compounds, the extent to which carboxylic acid addition can influence these reactions, and the relative distribution of sorbed P in an acid soil. The addition of carboxylic acids did not change total P sorption, with solid-phase P binding to metal and organic complexes. No treatment effects on P bonding were evident, as measured by μ-XRF and μ-XANES. While μ-XRF and μ-XANES did provide information on P interactions, the high spatial heterogeneity within samples and the need to focus on areas of high P concentration diminished our ability to identify clear treatment effects at the micro scale. Nevertheless, this research did highlight the value of utilizing complementary techniques (solution analyses, XRF, μ-XRF mapping, and XANES) to generate new knowledge about P chemistry in soils.


Over the last decade, numerous educational institutions and corporate world have employed various kinds of e-learning software solutions. One of the major components of end-to-end e-learning solution is the learning management system (LMS). These LMS are either developed as open source software (OSS) or close source software (CSS) product. In this regard, CSS for e-learning systems has a major drawback of being expensive and this hinders its widespread use. On the other hand, OSS is virtually free and not restricted by the licensing costs. The benefits of OSS can be completely realized only if there is an effective contribution from OSS community towards its development.

It is clear from the literature that the OSS development community does not follow an explicitly defined and documented software development process. This in turn results in lack of detailed information in the literature about the problems arising due to the absence of a defined process. Nevertheless, some of the major issues with regard to OSS development for LMS that have been identified include software design issues, week user Interface, lack of complete and accessible documentation, lack of co-ordination between unknown developers, etc.

This research develops a generalized OSSD process that could be used for the development of an open source (OS) e-learning system. To begin, in order to understand the current development practises of the existing OS e-learning systems, a detailed analysis was carried out for three different and popular OS e-learning systems (Moodle, ILIAS and Dokeos). The result of this analysis was represented as an Activity Flow Diagram which enabled precise identification of the implicit software development stages. In the next stage, in order to identify the output produced for each and every stage of development, a DEMO methodology was applied and DEMO models were built for three e-learning systems (Moodle, ILIAS and Dokeos). This is a particularly novel contribution that helps enable the development of the generalized OSSD process.

In order to select the different stages of development for the proposed process, the output resulting from each stage of the DEMO model was compared with the outputs prescribed by the ISO/IEC 12207:2008 standard. Further, in order to validate the proposed process, an expert review method was employed by preparing a web-based questionnaire and circulating it along with the proposed process to three different and geographically separated OS experts. The proposed process was subsequently refined based on the feedback received from these experts. It is anticipated that the proposed OSSD process had the potential to streamline the future development of OS e-learning systems.


"... true enforcement [is] not the pretend variety that comes with soldiers in blue berets who have neither the capacity nor the wit to do anything about the breaches of international law occurring around them." At the height of the Sierra Leone crisis two years ago, the international media focused on the inability of the United Nations to prevent humanitarian disasters even in areas where it was already engaged. The images of Rwanda and Bosnia were invoked once again. Michael Ignatieff, director of the Carr Center of Human Rights Policy at Harvard University, suggested in a New York Times editorial that the United Nations and its pretense of effectiveness contributed to the deteriorating circumstances in many parts of the world. He argued for deploying "combat capable warriors under robust rules of engagement, with armour, ammunition and intelligence capability and a single line of command to a national government or regional alliance" (1) in peacekeeping operations. In the military, we used to call these activities war, not peace operations. We were, however, referring to wars between sovereign states, not civil wars. In contrast, civil wars were seen as horrible, lawless and potentially unending conflicts that could test the very fabric of a foreign nation's society (e.g., Vietnam for America, Afghanistan for the Soviet Union). It was generally recognized that there were no rewards for getting involved in civil wars. Ignatieff's proposal perhaps shows how the perception of international conflict and peacekeeping has changed. Since 1989, the United Nations has deepened its entanglement in humanitarian-motivated missions that blur the lines between war and peace operations. The additional haziness generated when defining terms such as peace enforcement and peacekeeping has intensified the debate about what is happening to the world order and whether we are experiencing an enduring normative shift in the foundation of international relations. This is a fine debate for academics. But in the field, where the young men and women of international peace forces do their jobs and save lives, the confusion challenges not only theoretical standpoints, but their physical and moral well-being. Nonetheless, despite these apprehensions, the military must engage in all aspects of this debate, especially to help define the relationship between humanitarian interventions and the military. THE CHARTER AND PEACEKEEPING The UN Charter captures the international community's determination to confront the devastation of the 20th century's two world wars and ensure that such conflict never occurs again. The advent of weapons of mass destruction heightened the determination and indeed, necessity, to place human relations on a footing that allowed conflict to be moderated by the conciliatory processes of mediation and negotiation. The Charter and its commitment to the nation-state is the basis of the international order. The International Court of Justice and the Charter, both established around 1945, deal with the resolution of differences between nation-states. Peacekeeping, however, is not mentioned in the Charter. It emerged out of the commitment of the United Nations to encourage and help nations resolve their differences through peaceful means. Peacekeeping started in 1948 with the emergence of Israel and the establishment of the United Nations Truce Supervision Organization (UNTSO), which included unarmed military observers to aid and advance the armistice between Israel, Lebanon, Syria and Egypt. Soon after, in 1949, the United Nations Military Observer Group in India and Pakistan (UNMOGIP) was established in Kashmir to observe the truce on the Indian and Pakistani border. Both of these truce observance missions still exist and could be called the source of traditional global peacekeeping culture. Their continued existence demonstrates that traditional peacekeeping does not solve disputes, but creates an atmosphere that prevents the situation from worsening and enables the possibility of progress. …


Objectives: Abacavir (ABC) treatment is associated with hypersensitivity reactions in ~8% of Caucasians, and is highly predicted by the presence of the HLA-B*5701 allele. We aimed to determine the incidence of abacavir hypersensitivity reactions (ABC-HSR) after the introduction of prospective HLA-B*5701 screening.

Methods: All antiretroviral therapy (ART)-naive and ARTexperienced but abacavir-naive patients starting a new NRTIbackbone regimen after January 2002 were included. HLA-typing was performed by sequence-based methods, with avoidance of ABC in HLA-B*5701-positive patients. ABC-HSR was assessed using standardised clinical criteria and adjunctive epicutaneous patch testing in all patients with <6 weeks of ABC exposure.

Results: ART-naive patients: 44 (37%) of 120 HLA-B*5701- negative patients started ABC and in 2 of these, ABC was discontinued within 6 weeks (1 diarrhoea, 1 headache probably zidovudin-related). ABC was prescribed for 1 of 8 HLA-B*5701- positive patients (HLA results not reviewed prior to therapy) who developed ABC-HSR and had a positive patch test. ARTexperienced patients: 106 (64%) of 164 HLA-B*5701-negative patients started ABC and in 3 of these, ABC was discontinued within 6 weeks: 1 with non-specific symptoms of headache and cold sweats not responsive to ABC withdrawal; and 2 with symptoms attributed to efavirenz or nevirapine (1 nausea, 1 rash) associated with negative ABC-patch-tests. 2 of 14 HLA-B*5701- positive patients started ABC: 1 HLA results not reviewed, 1 informed choice based on absence of HLA-B57-associated ancestral haplotype markers and limited treatment options; both patients experienced ABC-HSR and had positive patch tests results. After introduction of HLA-B*5701 screening before starting ABC, ABC-HSR was experienced by 1.9% (95% CI of 0.4%-5.6%) of all patients and by 0% of HLA-B*5701 negative patients, compared with 7% ABC-HSR prior to genetic screening.

Conclusion: Avoiding ABC in patients carrying the susceptibility locus HLA-B*5701 by prospective genetic screening dramatically decreased the incidence of ABC-HSR in the Western Australian HIV Cohort.


In the short and medium terms, biofuels are the most viable alternative to reduce the environmental impact of fossil fuels. The recent controversy over the competition between biofuels and food production increases the complexity of investment decisions in the biodiesel production chain. In this context, decision support tools are highly relevant. The purpose of this article is to describe the BiodieselFAO using the Unified Modeling Language (UML). An integrated analysis considering both agricultural and industrial sectors was identified as a key requirement to the system. Therefore, farmers and industry are the main actors in the use case diagram. As the raw material represents around 70% of the industrial cost of biodiesel production, the price negotiation of raw material (oilseeds) is the central use case. Configuration, agriculture, industry, results and scenarios are the modules, which encompass the functionalities derived from the UML diagrams. The Food and Agriculture Organization of the United Nations (FAO) has made the BiodieselFAO available, free of charge, to around 180 professionals from 17 Latin American countries. Additionally, the developing team has supported the usage of the BiodieselFAO in several biodiesel investment analyses throughout Latin America. The system was also useful in the design and analysis of policy related to biodiesel industry in Brazil.


The organization of music is a subject that has fascinated classification researchers and librarians alike for over a hundred years. This paper identifies five key methodological approaches undertaken by commentators on music knowledge organization, which demonstrate different interdependent relationships between musicology and classification. Five significant themes form the main body of this paper, and these themes underpin the corpus of music classification literature. The first theme concerns the question of whether classification should divide music materials into their constituent formats. This division sets conceptual against practical. The second theme looks at facets in music classification. 'Medium' and 'form' are considered to be the most important facets for music scores; 'composers' are an important facet for music literature. The third theme considers the poor treatment of 'other' musics in knowledge organization, and notes some possible explanations. The fourth theme investigates the relationship between the classification and retrieval of music materials. This section highlights the differing needs of users and suggests how the classification of music materials is adapted accordingly. The fifth theme discusses pre-existing music classification schemes, with the large number of home-grown and special schemes highlighted. The paper concludes that the five identified themes point towards a model of music classification. However, the model is not just concerned with facets, musics and formats; it is also based upon the relationships between various sets of protagonists, such as the librarian and the musicologist, the musicologist and the performer. Through studying these protagonists, the traditional boundaries of musicology, music librarianship and knowledge organization will be crossed.


This report is the result of the Master of Science thesis of the author, at the Delft University of Technology, sub-Faculty of Civil Engineering. Although a lot is known nowadays about the run-up on smooth and impermeable slopes as well as the run-up on slopes covered with a rock armour layer, the physical properties of the armour layer of a rubble mound breakwater are not incorporated in the relations describing the run-up on a breakwater's slope. The roughness of a slope and its permeability, which can be described by a characteristic diameter of the armour unit and the porosity of the layer, are not used in the description of the run-up. This report is an attempt to get insight into the influence that the roughness and the permeability of a slope have on the run-up on this slope. In order to achieve this goal, dimensional parameters are derived describing the roughness of a slope and its permeability. Firstly, the framework of the design of a breakwater is given in order to place the run-up on a rough, permeable slope. The run-up itself is dealt with separately. Experiments were performed in order to obtain data that can be used to quantify the influence of the roughness of the slope and its permeability. The experiments were performed leaving the permeability of the whole structure out of consideration. To achieve a difference in porosity of the armour layer, rock armour units were used as well as tetrapod armour units. Two approaches of data analysis are applied on the data obtained from these experiments. This first approach describes the run-up on a rough, permeable slope by a combination of a roughness parameter, a permeability parameter and the breaker parameter. The roughness parameter and the permeability parameter are derived by forming non-dimensional parameters that describe roughness and permeability. The run-up, usually made non-dimensional using the wave height (H) is made non-dimensional here using the nominal diameter. This gave better results in combination with the derived parameters describing the roughness and the permeability of a slope. The second approach describes the run-up on a rough, permeable slope by using the relative run-up R.lH and a newly derived non-dimensional parameter resembling the Iribarren parameter, but incorporating the influence of the permeability of the armour layer. When the relative run-up is put against the Iribarren parameter and is put against the newly derived non-dimensional parameter, the appearing scatter is less in the latter case. In both approaches, two relations describing the run-up on a rough permeable slope are derived. One for breaking waves and one for non-breaking waves. For the second approach, the found relations have a significant resemblance with the known formulae for run-up on a slope covered with rock armour units, derived by van der Meer and Starn. When the relations derived following the both approaches are compared, the relations derived by the second approach are the relations that give the best feeling with the physical processes as they occur. The relation for non-breaking waves, derived using the first approach, is applied on data obtained from physical model tests on a breakwater covered with tetrapod armour units. The calculated nondimensional run-up is compared with the measured non-dimensional run-up. The results show that the permeability of the whole structure can not be neglected, especially inthe case of non-breaking waves.


Literature is at the heart of popular understandings of the First World War in Britain, and has perpetuated a popular memory of the conflict centred on disillusionment, horror and futility. This book examines how and why literature has had this impact, exploring the role played by authors, publishers and readers in constructing the memory of the war since 1918. It demonstrates that publishers were as influential as authors in shaping perceptions of the conflict, and it provides a detailed analysis of critical and popular responses to war books, tracing the evolution of readers' attitudes to the war between 1918 and 2014. By exploring the cultural legacy of the war from these two previously overlooked perspectives, Vincent Trott offers fresh insights regarding the emergence of a collective memory of the First World War in Britain.

Drawing on a broad range of primary source material, including publishers' correspondence, dust jackets, adverts, book reviews and diary entries, and examining canonical authors such as Wilfred Owen, Siegfried Sassoon and Vera Brittain alongside long-forgotten texts and more recent autobiographical works by Harry Patch and Henry Allingham, Publishers, Readers and the Great War provides a rich and nuanced analysis of the climate within which First World War literature was written, published and received since 1918.


Nowadays Information Systems (IS) are designed for individual task execution control allowing coordinating, monitoring, and supporting the logistical aspects of a business process, in other words, the IS has to manage the flow of work through the organization. The WorkFlow Management represents a critical issue for achieving enterprise competitiveness among organizations. Many companies have realized that the business processes (BP) within their organizations, and between the companies and their partners have not been clearly described and there are not enough techniques and methods to automate the processes. The Workflow Management Coalition (WFMC) states that workflow (WF) is concerned with the automation of procedures where documents, information, or tasks are passed to the participants according to a defined set of rules to achieve, or contribute to, an overall business goal (WfMC, 1999). Another definition of WF can be found in (Rusinkiewicz & Seth, 1994) where workflows are activities involving the coordinated execution of multiple tasks performed by different processing entities (persons or machines). A task or process involves a piece of work and a process entity which executes the work. Workflow Management (WFM) is a fast evolving technology which is increasingly being exploited by businesses in a variety of industries. Its primary characteristic is the automation of processes involving combinations of human and machine-based activities (Aalst & Hee, 2002), (Aalst, 1998). A Workflow Management System (WFMS) provides procedural automation of a business process by management of the sequence of work activities and the invocation of appropriate human and/or IT resources associated with the various activity steps. Although the most prevalent use of WFMS is within the office environment in staff intensive operations such as insurance, banking, legal and general administrations, etc, it is also applicable to some classes of industrial and manufacturing applications (WfMC, 1995). WFMS needs to integrate other technologies such that agent technology, which provides flexible, distributed, and intelligent solutions for business process management. This work presents a methodology for mobile agentbased WFMS development. The proposed methodology consists of a modular and gradual specification of the system where a mobile agent guides the process through organizational units and executes different tasks. Several mobile agents evolve through the system executing concurrently their assigned task.


It is widely recognized that writing is central to teaching and learning in post-secondary contexts. Writing is also, almost certainly, a key to student success and retention. The response of universities around the world has been to establish Writing Centres and these have played a pivotal role in helping students succeed. However, as is argued in this paper, there should be a broader responsibility to develop student writing. Academic writing is fraught with hidden rules and implicit discursive practices that are often discipline specific. Far from being a discrete and separate 'skill', writing is part of a complex network of social practices conducted within different academic discourses. This insight is crucial because it is a prerequisite for making meaningful pedagogic recommendations. Academic writing requires an understanding of shifting and competing discourse requirements, how the 'self' is bound up in writing, how authority is constructed, how language is shaped and shapes, how some ways of writing are privileged and others not, and what is valued in this context. The paper unpacks several ways in which the requirements of academic writing can be made more explicit.


This article tells the story of Wickard v. Filburn, 317 U.S. 111 (1942). After providing a survey of American agriculture and its regulation between the World Wars, this article describes the constitutional landmark that began as a controversy over Roscoe Filburn's 1941 wheat crop. Wickard v. Filburn represents a pivotal moment in the Supreme Court's effort to define Congress's power [t]o regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes. Greater turmoil over commerce clause jurisprudence has breathed new life into Wickard v. Filburn.


In this review the quality properties of linseed oil for food uses are discussed as well as factors affecting this quality. Linseed oil has a favourable fatty acid composition with a high linolenic acid content. Linseed oil contains nearly 60% α-linolenic acid, compared with 25% for plant oils generally. The content of linolenic acid and omega-3 fatty acids is reported to be high in linseed grown in northern latitudes. The composition of fatty acids, especially unsaturated fatty acids, reported in different studies varies considerably for linseed oil. This variation depends mainly on differences in the examined varieties and industrial processing treatments. The fatty acid composition leads also to some problems, rancidity probably being the most challenging. Some information has been published concerning oxidation and taste, whereas only a few studies have focused on colour or microbiological quality. Rancidity negatively affects the taste and odour of the oil. There are available a few studies on effects of storage on composition of linseed oil. In general, storage and heat promote auto-oxidation of fats, as well as decrease the amounts of tocopherols and vitamin E in linseed oil. Several methods are available to promote the quality of the oil, including agronomic methods and methods of breeding as well as chemical, biotechnological and microbiological methods. Time of harvesting and weather conditions affect the quality and yield of the oil.


This book proposes a new theory ("proximization theory") in the area of political/public legitimization discourse. Located at the intersection of Pragmatics, Cognitive Linguistics and critical approaches, the theory holds that legitimization of broadly consequential political/public policies, such as pre-emptive interventionist campaigns, is best accomplished by forced construals of virtual external threats encroaching upon the speaker and her audience's home territory. The construals, which proceed along spatial, temporal and axiological lines, are forced by strategic deployment of lexico-grammatical choices drawn from the three domains. This proposal is illustrated primarily in the in-depth analysis of the 2001-2010 US discourse of the War-on-Terror, and secondarily in a number of pilot studies pointing to a wide range of further applications (environmental discourse, health communication, cyber-threat discourse, political party-representation). The theory and the empirical focus of the book will appeal to researchers working on interdisciplinary projects in Pragmatics, Semantics, Cognitive Linguistics, Critical Discourse Studies, as well as Journalism and Media Studies.


We demonstrate a compact, narrow-linewidth, high-power, micro-integrated semiconductor-based master oscillator power amplifier laser module which is implemented on a footprint of 50 x 10 mm(2). A micro-isolator between the oscillator and the amplifier suppresses optical feedback. The oscillator is a distributed Bragg reflector laser optimized for narrow-linewidth operation and the amplifier consists of a ridge waveguide entry and a tapered amplifier section. The module features stable single-mode operation with a FWHM linewidth of only 100 kHz and an intrinsic linewidth as small as 3.6 kHz for an output power beyond 1 W.


Nef, a multifunctional HIV protein, activates the Vav/Rac/p21-activated kinase (PAK) signaling pathway. Given the potential role of this pathway in the activation of the phagocyte NADPH oxidase, we have investigated the effect of the HIV-1 Nef protein on the phagocyte respiratory burst. Microglia (cell line and primary culture) were transduced with lentiviral expression vectors. Expression of Nef did not activate the NADPH oxidase by itself but led to a massive enhancement of the responses to a variety of stimuli (Ca2+ ionophore, formyl peptide, endotoxin). These effects were not caused by up-regulation of phagocyte NADPH oxidase subunits. Nef mutants lacking motifs involved in the interaction with Vav and PAK failed to reproduce the effects of wild type Nef, suggesting a role for the Vav/Rac/PAK signaling pathway. The following results suggest a key role for Rac in the priming effect of Nef. (i) Inactivation of Rac by Clostridium difficile toxin B abolished the Nef effect. (ii) The fraction of activated Rac1 was increased in Nef-transduced cells, and (iii) the dominant positive Rac1(V12) mutant mimicked the effect of Nef. These results are to our knowledge the first analysis of the effect of Rac activation on the NADPH oxidase in intact phagocytes. Rac activation is not sufficient to stimulate the phagocyte NADPH oxidase; however, it markedly enhances the NADPH oxidase response to other stimuli.


The siting of a c. 25 km wide, transpressive, high-strain zone at the eastern margin of the Gander Zone of NE Newfoundland corresponds to the trace of a fundamental contact between two Gondwanan basement blocks displaced sinistrally relative to one another during Silurian orogenesis. Changes in plate motion during the Devonian led to kinematic reversal and reactivation of the shear zone and, at high structural levels, the development of a major brittle-ductile fault system. At a local scale within the Silurian ductile high-strain zone, the focus of deformation and shifts in siting of shear were closely related to magma presence. We consider that granite magmas exploited shear zones within the crust to aid ascent, and in doing so enhanced local deformation. Cessation of magma supply and/or cooling of magmas within conduits caused deformation to relocate elsewhere. NE Newfoundland hence provides an example of how fault/shear zone siting and reactivation may be controlled by regional-scale pre-existing basement configuration and more localised processes affecting rheology, notably plutonism.


"The paper develops indicators to look at the performance of the irrigation sector in Sub-Saharan Africa, where demand for food is high and irrigation has a proven potential to boost levels of agricultural productivity. By looking at six indicator categories—institutional framework, water resource use, irrigation area, irrigation technology, agricultural productivity, and poverty and food security—we assess the potential for improving performance in the agricultural food security sector through increasing irrigation sector investments. The indicators on water resource use indicate ample room for further development of the resource. The share of cultivated area equipped for irrigation in Africa is about a third of the world average and just one-sixth of the value for Asia. The low coverage of irrigation technology and the slow rate of growth in coverage clearly represent a lost opportunity for Africa and a tremendous potential for future investment and policy effort. Finally, African countries produce 38 percent of their crops (by value) from approximately 7 percent of their cultivated land on which water is managed, which again suggests that additional investment in irrigation would pay large benefits. The disproportionate contribution to agricultural production of Africa's small irrigated area suggests that returns on additional investment in irrigation would be high, both in terms of greater food security for the continent and greater production of export-quality agricultural goods." from authors' abstract


This paper summarizes the lessons learned in the process of building a microsimulation tool tailored to country-specific conditions and involving a maximum degree of user control. The objective to construct a model useful in the process of budgeting and fiscal forecasting has been achieved by paying attention to policy simulation details as well as to the representativeness of the underlying micro-dataset. The validity of simulated results improved significantly after the input database sample has been reweighted in such a way that the new weights replicate, among other factors, the earned income distribution and selected age cohorts directly. Innovative approaches in bringing the model closer to legislation as well as data highlight the benefits of having more user control compared with standardized microsimulation tools.


Current anti-angiogenic treatments involve the attenuation of signalling via the pro-angiogenic vascular endothelial growth factor/receptor (VEGF/VEGFR) axis. Stimulation of angiogenesis by VEGF requires the activation of the calcineurin/nuclear factor of activated T-cells (NFAT) signal transduction pathway which is inhibited by Plasma Membrane Calcium ATPase 4 (PMCA4), an endogenous calcium extrusion pump. However, PMCA4s role in calcineurin/NFAT-dependent angiogenesis is unknown. Using "gain of function" studies, we show here that adenoviral overexpression of PMCA4 in human umbilical vein endothelial cells (HUVEC) inhibited NFAT activity, decreased the expression of NFAT-dependent pro-angiogenic proteins (regulator of calcineurin 1.4 (RCAN1.4) and cyclooxygenase-2) and diminished in vitro cell migration and tube formation in response to VEGF-stimulation. Furthermore, in vivo blood vessel formation was attenuated in a matrigel plug assay by ectopic expression of PMCA4. Conversely, "loss of function" experiments by si-RNA-mediated knockdown of PMCA4 in HUVEC or isolation of mouse lung endothelial cells from PMCA4−/− mice showed increased VEGF-induced NFAT activity, RCAN1.4 expression, in vitro endothelial cell migration, tube formation and in vivo blood vessel formation. Additionally, in an in vivo pathological angiogenesis model of limb ischemia, the reperfusion of the ischemic limb of PMCA4−/− mice was augmented compared to wild-type. Disruption of the interaction between endogenous PMCA4 and calcineurin by adenoviral overexpression of the region of PMCA4 that interacts with calcineurin (residues 428–651) increased NFAT activity, RCAN1.4 protein expression and in vitro tube formation. These results identify PMCA4 as an inhibitor of VEGF-induced angiogenesis, highlighting its potential as a new therapeutic target for anti-angiogenic treatments.


Despite its negative reputation, lobbying is an important vehicle for ensuring citizen participation in the democratic process, allowing a vibrant and participatory democracy. This article supports the pluralistic theory of democracy, which views democracy as an arena in which interest groups struggle to attain the utmost realization of their interests. Yet social scientists have repeatedly shown that the modus operandi of lobbyists and interest groups casts a heavy shadow over the pluralistic vision of a vibrant and participatory democracy, and that interest groups' lobbying comes often at the expense of the majority. The article identifies three flaws in the democratic process resulting from lobbying: personal corruption (the 'revolving door' phenomenon and the dependence of representatives on campaign financing); unequal power of influence resulting in the distortion of the public agenda; and niche lobbying without competitive counter lobbying. Concentrating on the problem of lack of competition, we suggest that the existing transparency requirements of the Lobbying Disclosure Act, 1995 do not attain the goal of creating a rivalry of the type that the pluralistic conception seeks to advance. We propose to expand the scope of the transparency requirements in the law, by requiring lobbyists to publish online all written material transmitted to politicians and to list all areas of lobbying activity. This requirement, we believe, will reduce monitoring costs for rival interest groups and is likely to increase competitive lobbying.


### Contents

#### News

The Hydrogen Backlash

The Carbon Conundrum

Choosing a CO2 Separation Techology

Fire and ICE: Revving Up for H2

Will the Future Dawn in the North?

Can the Developing World Skip Petroleum?

#### Review

Stabilization Wedges: Solving the Climate Problem for the Next 50 Years with Current Techologies S. Pacala and R. Socolow

#### Viewpoints

Sustainable Hydrogen Production J. A. Turner

Hybrid Cars Now, Fuel Cell Cars Later N. Demirdoven and J. Deutch

See related Editorial.

S een up close, hydrogen looks like a recipe for success. Small and simple—one proton and one electron in its most common atomic form—hydrogen was the first element to assemble as the universe cooled off after the big bang, and it is still the most widespread. It accounts for 90% of the atoms in the universe, two-thirds of the atoms in water, and a fair proportion of the atoms in living organisms and their geologic legacy, fossil fuels.

To scientists and engineers, those atoms offer both promise and frustration. Highly electronegative, they are eager to bond, and they release energy generously when they do. That makes them potentially useful, if you can find them. On Earth, however, unattached hydrogen is vanishingly rare. It must be liberated by breaking chemical bonds, which requires energy. Once released, the atoms pair up into two-atom molecules, whose dumbbell-shaped electron clouds are so well balanced that fleeting charge differences can pull them into a liquid only at a frigid −252.89° Celsius, 20 kelvin above absolute zero. The result, at normal human-scale temperatures, is an invisible gas: light, jittery, and slippery; hard to store, transport, liquefy, and handle safely; and capable of releasing only as much energy as human beings first pump into it. All of which indicates that using hydrogen as a common currency for an energy economy will be far from simple. The papers and News stories in this special section explore some of its many facets.

Consider hydrogen's green image. As a manufactured product, hydrogen is only as clean or dirty as the processes that produce it in the first place. Turner (p. 972) describes various options for large-scale hydrogen production in his Viewpoint. Furthermore, as News writer Service points out (p. [958][1]), production is just one of many technologies that must mature and mesh for hydrogen power to become a reality, a fact that leads many experts to urge policymakers to cast as wide a net as possible.

In some places, the transition to hydrogen may be relatively straightforward. For her News story (p. 966), Vogel visited Iceland, whose abundant natural energy resources have given it a clear head start. Elsewhere, though, various technological detours and bridges may lie ahead. The Viewpoint by Demirdoven and Deutch (p. [974][2]) and Cho's News story (p. 964) describe different intermediate technologies that may shape the next generation of automobiles. Meanwhile, the fires of the fossil fuel-based "carbon economy" seem sure to burn intensely for at least another half-century or so [see the Editorial by Kennedy (p. [917][3])]. Service's News story on carbon sequestration (p. 962) and Pacala and Socolow's Review (p. [968][4]) explore strategies—including using hydrogen—for mitigating their effects.

Two generations down the line, the world may end up with a hydrogen economy completely different from the one it expected to develop. Perhaps the intermediate steps on the road to hydrogen will turn out to be the destination. The title we chose for this issue—Toward a Hydrogen Economy— reflects that basic uncertainty and the complexity of what is sure to be a long, scientifically engaging journey.

 [1]: /lookup/doi/10.1126/science.305.5686.958
 [2]: /lookup/doi/10.1126/science.1093965
 [3]: /lookup/doi/10.1126/science.305.5686.917
 [4]: /lookup/doi/10.1126/science.1100103