This thesis examines web-server architectures for static workloads on both uniprocessor and multiprocessor systems to determine the key factors affecting their performance. The architectures examined are event-driven (μserver) and pipeline (WatPipe). As well, a thread-per-connection (Knot) architecture is examined for the uniprocessor system. Various workloads are tested to determine their effect on the performance of the servers. Significant effort is made to ensure a fair comparison among the servers. For example, all the servers are implemented in C or C++, and support sendfile and edge-triggered epoll. The existing servers, Knot and μserver, are extended as necessary, and the new pipeline-server, WatPipe, is implemented using μserver as its initial code base. Each web server is also tuned to determine its best configuration for a specific workload, which is shown to be critical to achieve best server performance. Finally, the server experiments are verified to ensure each is performing within reasonable standards. The performance of the various architectures is examined on a uniprocessor system. Three workloads are examined: no disk-I/O, moderate disk-I/O and heavy disk-I/O. These three workloads highlight the differences among the architectures. As expected, the experiments show the amount of disk I/O is the most significant factor in determining throughput, and once there is memory pressure, the memory footprint of the server is the crucial performance factor. The peak throughput differs by only 9–13% among the best servers of each architecture across the various workloads. Furthermore, the appropriate configuration parameters for best performance varied based on workload, and no single server performed the best for all workloads. The results show the event-driven and pipeline servers have equivalent throughput when there is moderate or no disk-I/O. The only difference is during the heavy disk-I/O experiments where WatPipe's smaller memory footprint for its blocking server gave it a performance advantage. The Knot server has 9% lower throughput for no disk-I/O and moderate disk-I/O and 13% lower for heavy disk-I/O, showing the extra overheads incurred by thread-per-connection servers, but still having performance close to the other server architectures. An unexpected result is that blocking sockets with sendfile outperforms non-blocking sockets with sendfile when there is heavy disk-I/O because of more efficient disk access. Next, the performance of the various architectures is examined on a multiprocessor system. Knot is excluded from the experiments as its underlying thread library, Capriccio, only supports uniprocessor execution. For these experiments, it is shown that partitioning the system so that server processes, subnets and requests are handled by the same CPU is necessary to achieve high throughput. Both N-copy and new hybrid versions of the uniprocessor servers, extended to support partitioning, are tested. While the N-copy servers performed the best, new hybrid versions of the servers also performed well. These hybrid servers have throughput within 2% of the N-copy servers but offer benefits over N-copy such as a smaller memory footprint and a shared address-space. For multiprocessor systems, it is shown that once the system becomes disk bound, the throughput of the servers is drastically reduced. To maximize performance on a multiprocessor, high disk throughput and lots of memory are essential.


Lamina size, thickness, venation, and anatomy are studied in 15 species of Heliconia (Heliconiaceae), 3 species of Musa, and 1 of Ensete (Musaceae). The most typical laminas of these genera are large and oblong and have an acute or irregular apex and an asymmetrical cordate base. The laminar veins are parallel and are oriented essentially perpendicular to the costa and the margin. However, there is considerable variation in lamina architecture in the Heliconiaceae. Thickness ranges considerably across the lamina, with considerable variation between species. The only pattern common to all species is that the blades are thinner at the margin than at the costa. The veins of the lamina occur in a number of size classes that are arranged into a repeating unit called a set. Set patterns are described for the species and families. Although the Heliconiaceae and Musaceae do not differ in general set pattern, variation in the Heliconiaceae tends toward simpler sets, whereas the Musaceae tends towards more complex sets. Lamina anatomy is similar to that reported in the literature for these families, with several notable exceptions. The Heliconiaceae and Musaceae may be distinguished by characteristics of their lamina anatomy and by the fact that Musaceae blades have an irregular apex. The value of these characters for taxonomic and cladistic analyses is discussed.


This article reviews recent literature on the political ecologies of conservation and environmental change mitigation, highlighting the biopolitical stakes of many writings in this field. Although a large and apparently growing number of political ecologists engage the concept of biopower directly – in its Foucauldian, Agambenian, and various other formulations – recent writings across the humanities and social sciences by scholars utilizing an explicitly biopolitical lens provide us with an array of concepts and research questions that may further enrich writings within political ecology. Seeking to extend dialogue between scholars of biopolitics, of political ecology, and of both, then, this article surveys both new and shifting contours of the various ways in which contemporary political ecologies increasingly compel us to bring the very lives of various human and nonhuman populations, as Foucault once put it, "into the realm of explicit calculations." In doing so, 'new frontiers' of biopolitical inquiry are examined related to: i) species, varieties, or 'multiple modes' of governmentality and biopower; ii) critical (ecosystem) infrastructure, risk, and 'reflexive' biopolitics; iii) environmental history, colonialism, and the genealogies of biopower, and iv) the proliferation of related neologisms, such as ontopower and geontopower.


Background and aim : Carpet knitters play an important role in economic systems of families and they are dealing with stress at work for many reasons. Therefore, they need both external and internal supporting resources for coping with these stresses. Among supporting resources, self-esteem is the most internal and social support is the most external supporting resources. This study was designed to identify the relationship between perceived social support and self-esteem in Naeen village ' s carpet knitters. Methods: This study is a descriptive- analytical research with correlation design. Two hundred carpet knitters of Naeen's villages were assessed using two questionnaires; "Cooper Smith' scale of self-esteem and multidimensional scale of perceived social support. Results were analyzed using Pearson Correlation Coefficient and Multiple Regression. Results: According to Pearson correlation coefficient, a significant correlation was found between self esteem and social support, r = 0.48, (p< 0.001). Conclusion: Consequently, social support can influence the individuals self-esteem and when people have higher self-esteem and self- confidence, they can play their roles properly and achieve more success in both private and social life


Context. Feedback by massive stars shapes the interstellar medium and is thought to influence subsequent star formation. The details of this process are under debate.
Aims. We exploited observational constraints on stars, gas, and nucleosynthesis ashes for the closest region with recent massive-star formation, Scorpius–Centaurus OB2, and combined them with three-dimensional (3D) hydrodynamical simulations in order to address the physics and history of the Scorpius–Centaurus superbubble.
Methods. We used published cold gas observations of continuum and molecular lines from Planck, Herschel, and APEX. We analysed the Galactic All Sky Survey (GASS) to investigate shell structures in atomic hydrogen, and used Hipparcos and Gaia data in combination with interstellar absorption against stars to obtain new constraints for the distance to the Hi features. Hot gas is traced in soft X-rays via the ROSAT all sky survey. Nucleosynthesis ejecta from massive stars were traced with new INTEGRAL spectrometer observations via 26Al radioactivity. We also performed 3D hydrodynamical simulations for the Sco–Cen superbubble.
Results. Soft X-rays and a now more significant detection of 26Al confirm recent (≈1 Myr ago) input of mass, energy, and nucleosynthesis ejecta, likely from a supernova in the Upper Scorpius (USco) subgroup. We confirm a large supershell around the entire OB association and perform a 3D hydrodynamics simulation with a conservative massive star population that reproduces the morphology of the superbubble. High-resolution GASS observations reveal a nested, filamentary supershell. The filaments are possibly related to the Vishniac clumping instability, but molecular gas (Lupus I) is only present where the shell coincides with the connecting line between the subgroups of the OB association, suggesting a connection to the cloud, probably an elongated sheet, out of which the OB association formed. Stars have formed sequentially in the subgroups of the OB association and currently form in Lupus I. To investigate the impact of massive star feedback on extended clouds, we simulate the interaction of a turbulent cloud with the hot, pressurised gas in a superbubble. The hot gas fills the tenuous regions of the cloud and compresses the denser parts. Stars formed in these dense clumps would have distinct spatial and kinematic distributions.
Conclusions. The combined results from observations and simulations are consistent with a scenario where dense gas was initially distributed in a band elongated in the direction now occupied by the OB association. Superbubbles powered by massive stars would then repeatedly break out of the elongated parent cloud, and surround and squash the denser parts of the gas sheet and thus induce more star formation. The expected spatial and kinematic distribution of stars is consistent with observations of Sco–Cen. The scenario might apply to many similar regions in the Galaxy and also to active galactic nucleus (AGN)-related superbubbles.


The current network architecture is constrained. The development of new protocols to cope with new demands in computer networks such as real time streaming and voice over IP is not an easy task. Other than developing new protocols, computer networks should be able to rapidly deploy changes across networking equipment. Software-Defined Networking promises to simplify network management tasks and enable rapid developments of new protocols. SDN separates the control plane from the data planes in the switches, bringing a level of abstraction needed to manage sets of switches from a central location. OpenFlow has become a de facto standard for communication between control plane and data planes. One key information for network planning and management is the traffic matrix (TM). TM is defined as the volume of traffic transported by the network during a period of time from any ingress node to any egress node in a network. OpenFlow-based networks in particular must be able to continuously monitor performance metrics, in order to quickly adapt forwarding rules to utilize network resources in the best possible manner. However, current solutions for monitoring either require special monitoring equipment or impose significant measurement overhead. In this thesis, we propose a distributed way of measuring traffic, where every ingress node in the network is responsible for measuring a portion of the traffic matrix. We only used a set of features already available in the latest version of OpenFlow without any need of modification in the platform. Therefore our framework can be deployed on any OpenFlow (version 1.3 or higher) enabled network. The effectiveness of our solution is demonstrated through series of emulation in Mininet and in a test-bed with low-end OpenFlow switches.


We consider the principles of communities of practice (CoP) and networked learning in higher education, illustrated with a case study. iCollab has grown from an international community of practice connecting students and lecturers in seven modules across seven higher education institutions in six countries, to a global network supporting the exploration and evaluation of mobile web tools to engage in participatory curriculum development and supporting students in developing international collaboration and cooperation skills. This article explores the interplay of collaboration and cooperation, CoP and networked learning; describes how this interplay has operated in iCollab; and highlights opportunities and challenges of learning, teaching and interacting with students in networked publics in higher education. Keywords:  communities of practice; networked learning; collaboration; cooperation; social media; mobile social media (Published: 1 March 2016) Citation:  Research in Learning Technology 2016,  24 : 26497 -  http://dx.doi.org/10.3402/rlt.v24.26497


Abstract Investigations on small Polynesian outliers have illustrated how difficult it can be to identify archaeological evidence of intrusion, or to interpret the effect of any intrusion on the resident populations. In Samoa, the still meagre amount of artefactual and faunal remains from archaeological excavations adds to these problems. A review of the known Samoan archaeological sequence finds little or no evidence of intrusion, apart from a probable post-settlement introduction of pigs and dogs. This need not mean that Samoa was ever isolated from contacts with other islands. Keywords: Triple-I model, Polynesian outliers, Lapita, subsistence, material culture, monuments In a recent paper, Addison and Matisoo-Smith (2010) proposed a "Triple-I Model" of intrusion, integration and innovation for the Samoan sequence. They suggested a possible arrival about 1500 BP of new people, who introduced new lineages of rats, dogs and chickens, new plants, new material culture, and new ideas, and tentatively proposed a route from the west through the low islands of Micronesia. Their paper stimulated me to think about the difficulties archaeologists face in identifying and interpreting evidence of intrusion and replacement, a subject that has long concerned me (Davidson 1970, 1974a). The present paper briefly considers problems in interpreting archaeological evidence of intrusion (or lack thereof) in several Polynesian outliers, and then reviews current evidence about aspects of the archaeological sequence in Samoa. Polynesian outliers Archaeological research on Polynesian outliers has been driven, not surprisingly, by the fact that these small islands in the geographical regions of Micronesia and Melanesia are today inhabited by people who speak Polynesian languages. Identifying the arrival of Polynesian speakers has been a major objective, which has, however, proved very difficult to achieve, as the following examples show. Nukuoro is the northernmost of the known Polynesian outliers. It is a small atoll between New Britain and Pohnpei, with only a few hundred inhabitants. In the 1870s, the German ethnographer, Kubary, recorded traditionally remembered canoe arrivals from some 17 different islands stretching from Yap to Rotuma. Some of the arrivals stayed and intermarried, some were killed, some were banished, some introduced new dances; those banished had introduced a new kind of murder (Kubary 1910: 6-8). Despite these historical accounts, the known archaeological sequence on the atoll, beginning about 1200 years ago (Davidson 1971, 1992) shows no evidence of intrusion or new arrivals apart from the late appearance of the serrated-edged pearl shell coconut grater. This archaeological sequence falls within the timeframe within which linguistic models would expect the present Polynesian language and its immediate ancestor to have been spoken on the atoll. Although Kirch (2000: 179-180) considered that "there is no reason why the Nukuoro sequence should not be regarded as 'Polynesian' from bottom to top", my own conclusion was that if Nukuoro had been uninhabited at the time of European contact it would never have been recognised as a Polynesian outlier. Leach and Ward (1981) faced a similar situation on the nearby Polynesian outlier of Kapingamarangi. Although Emory (1965: 1-2) considered it exclusively Polynesian, earlier German ethnographers had found what they considered Melanesian and Micronesian as well as Polynesian influences (Eilers 1934: 155). Leach and Ward (1981: 93-97) had difficulty in suggesting a likely origin for the people. They found no evidence of intrusion in the archaeological sequence, although they pointed to ethnographic evidence of a type of food preservation and a method of roof thatching that suggested contacts, perhaps drift voyages, from Kiribati or the Marshalls. The Polynesian outliers in the Santa Cruz group have much longer archaeological sequences than Nukuoro and Kapingamarangi, all beginning with ceramic occupations early in the first millennium BC. …


Retirement involves a reduction in work hours, and is usually associated with a reduction in household income, and both these factors can affect health. This dissertation comprises of three studies that, together, explore the (1) effect of own and spousal statutory pension eligibility on health outcomes; (2) effect of retirement and change in household income on self-reported and objectives measures of general health, mental health, and functional health; and (3) effect of retirement and change in household income on mortality.
The first study analyzes the effect of pension eligibility on health using data from the Health and Retirement Study (HRS) and the Survey on Health, Ageing and Retirement in Europe (SHARE). It finds that own pension eligibility is associated with better health for both sexes. The results also suggest intra-household spillovers as spousal pension eligibility reduces the odds of poor health outcomes for men and raises the odds of depression for women.
The second study estimates the effect of retirement and reduction in household income on health, controlling for the potential reverse causality from health, using pension eligibility and payment amounts as instruments that affect both retirement decisions and income in retirement. It uses longitudinal data on men and women from HRS and SHARE on retirement, income, and health, combined with data on statutory pension eligibility and payment amounts in each country. It finds that both being retired, and higher household income, are significantly associated with better health outcomes, such as lower risks of poor self-rated health, depression, or difficulty with activities of daily living. Overall, the results suggest that taken together these two effects combine to give a small improvement in health on average when people stop working and replace labor income with a lower pension.
The third study analyzes the impact of retirement and household income on the mortality of men in the United States using data from the HRS. It undertakes a survival analysis using a control function approach to allow for the fact that retirement and income may reflect unobserved health conditions that affect mortality. It identifies the model using early, and normal, statutory pension eligibility as instruments that affect retirement decisions and household income but do not directly affect mortality. The study finds that retirement and higher household income both substantially lower the hazard of mortality. Pension eligibility increases the likelihood of retirement, but reduces household income, but we estimate the net effect through both mechanisms to be a small reduction in mortality hazard.


Although Erasmus is now accepted as a harbinger of liberal trends in mainstream Christian theology, the radical - even subversive - aspects of his work have received less attention. Beginning with a redefinition of the term radicalism, Peter G. Bietenholz examines the ways in which the radical aspects of Erasmus' writings inspired radical reactions among sixteenth- and seventeenth-century readers. Bietenholz examines the challenges to orthodoxy in Erasmus' scholarly work on the New Testament and the ways in which they influenced generations of thinkers, including John Milton and Sir Isaac Newton. Turning to other aspects of Erasmus' writings, the author shows the ways in which his opposition to war encouraged radical manifestations of pacifism; how his reflections on freedom of thought and religious toleration elicited both warm approval and fierce rejection; and the ways his critical attitude helped foster the early modern culture of Scepticism. An engaging look at Erasmus' theological, philosophical and socio-political influence, Encounters with a Radical Erasmus will prove useful to scholars of humanism, theology, the Reformation and Renaissance.


Data assimilation (DA) methods continue to evolve in the design of streamflow forecasting procedures. Critical components for efficient DA include accurate description of states, improved model parameterizations, and estimation of the measurement error. Information about these components are usually assumed or rarely incorporated into streamflow forecasting procedures. Knowledge of these components could be gained through the generation of a Pareto-optimal set – a set of competitive members that are not dominated by other members when compared using evaluation objectives. This study integrates Pareto-optimality into the ensemble Kalman filter (EnKF) and the particle filter (PF). Comparisons are made between three methods: evolutionary data assimilation (EDA) and methods based on the integration of Pareto-optimality into the EnKF (ParetoEnKF) and into the PF (ParetoPF). The methods are applied to assimilate daily streamflow into the Sacramento Soil Moisture Accounting model in the Spencer Creek watershed in Canada. The updated members are applied to forecast streamflows for up to 10 days ahead, where forecasts for 1 day, 5 day and 10 day lead times are compared to observations. The results show that updated estimates are similar for all three methods. An evaluation of updated members for multi-step forecasting revealed that EDA had the highest forecast accuracy compared to ParetoEnKF and ParetoPF, which have similar accuracies.


American Studies, Western Theories, Local Practices American Studies in the United States has become a major forum for the advancement of cultural studies (CS), an interdisciplinary practice that is experiencing an unprecedented international boom not unlike the boom that American Studies experienced in the post-war years. Interestingly, both American Studies and cultural studies are often described as practices that stand at the crossroads of various discourses, the busy and vibrant "meeting point between different centers, disciplines, and intellectual movements." (1) Their influence spans the globe, from Great Britain and Western Europe, across the USA, to Africa, Asia, and Australia. In the case of cultural studies, the growing number of publications, the proliferation of websites, the opening of new departments and programs at universities, and the organization of numerous conferences all demonstrate the successful institutionalization and internationalization of this project all over the world. However, while cultural studies has become the dominant mode of cultural analysis in U.S.-based American Studies programs, it has not become a universal discourse. There still exist some exotic, or simply different locations where manners of studying culture--even American culture--do not conform to the paradigm of CS: post-Soviet Eastern Europe is one of these locations. My statement is based on several observations. First of all, it seems quite obvious at international conferences. I was personally struck by the absence of East-European cultural theorists at the 3rd International Crossroads in Cultural Studies Conference held at the University of Birmingham in 2000. The atmosphere of industrial Birmingham was a perfect match for the atmosphere of modern intellectual production: any distant observer would have been convinced that cultural studies is no marginal (say postmarxist) intellectual project, but a huge cultural industry producing and reproducing names, ideas, books, academic programs, journals, etc., at an impressive rate The session I chaired--"Cultural Studies in Eastern Europe: Western Theories vs. Local Practices"--was actually the only session at the conference that addressed the development of cultural studies in the region, its epistemological, political and methodological concerns. (2) Similarly striking was that among the more than 800 participants there were only eight East-European scholars, and, as I later learned from my conversations with them, (some Were anthropologists, others psychologists or teachers of English) not all came with a clear idea of what cultural studies is. Why should this be the case? Moreover, is it really worth posing the question? Does it matter if some parts of Europe neither know nor care about the existence of cultural studies? Second, let us turn to some recent publications (in English) dedicated to the study of contemporary East European culture. As far as I know, there have been very few attempts to analyze the current cultural situation in the region, and even those few attempts have been sporadic and produced by, or in cooperation with, Western theorists. (3) These are mainly scholars from the discipline of Slavic Studies who are often criticized for their conservatism (4) (gender studies and other critical approaches face strong resistance in this milieu) and Russia-centrism, which means that other East European cultures, particularly small ones, hardly get any attention at all. All this does not mean, however, that there is no reflection on the current cultural situation by East European scholars. On the contrary, many interesting books in the area of cultural analysis have been published during the last decade in Eastern Europe, mostly in various local languages. The question "Why do they not get translated into English" might lead us to a long (and probably futile) discussion on the complex interconnections between intellectual production and economic interests, between first and third world economies and politics. …


David Western, the conservation biologist who was sacked on 21 May as head of the Kenya Wildlife Service (KWS), was reinstated 6 days later for a 9-month term by Kenya President Daniel arap Moi. Western says he now hopes to be able to complete the restructuring of the agency, which runs Kenya9s national parks and other protected areas. He believes he was dismissed largely for refusing to allow mining concessions on park lands, and that his reinstatement "sends a very clear message that KWS lands are not up for grabs."


The remarkable synchrony between changes in temperature recorded in Greenland ice cores and variations in N isotope records from sedimentary cores recovered from the Arabian Sea and the Eastern Tropical North Pacific (ETNP) has provided evidence for teleconnections between changes in marine denitrification in the tropics and climate variations in the northern high latitudes. Changes in tropical denitrification have been attributed to changes in productivity, changes in the source of intermediate waters and the flux of dissolved oxygen to suboxic zones. Variations in marine denitrification and anammox occurring at intermediate depths in proximity to productive continental margins have had profound effects on the N:P ratio of upwelled waters between stadials and interstadials, and may have indirectly affected carbon sequestration in the ocean by changing the balance of nutrients available to primary productivity. Competitive equilibrium, the changing stoichiometric balance of elements available as nutrients and the shorter residence time of N compared to P are factors that are believed to favour diazotrophs (N2-fixing organisms) during interstadials and shift the competitive advantage to non-N2-fixing ecosystems during stadials. This study presents a very high-resolution analysis of sedimentary nitrogen isotope records, phosphorus concentrations and bulk detrital element concentrations from two cores collected along the Pacific Mexican Margin. The results show that the oxygen minimum zone (OMZ) bathing intermediate waters in ETNP is modulated by the interaction of a Northern Hemisphere climate component with the "leakage" of heavy nitrate believed to derive from the Eastern South Pacific (ESP). This southerly component has a more "Antarctic" timing and is similar to records from the Peru-Chile margin. The sedimentary core recovered from the Mazatlan margin shows a "Greenland" timing of millennial-scale events, with reduced upwelling and reduced primary productivity, a less intense OMZ leading to reduced denitrification and a more southerly position of the mid-tropospheric subtropical ridge during stadials. This would have increased the onshore flow of moist air, ultimately leading to increased precipitation along the western Mexican Margin. Interstadials show a reversal of these conditions. In contrast to the Mazatlan core, the N isotope record from the core recovered from the Gulf of Tehuantepec records an element of "Antarctic" timing superimposed on local, millennial-scale variations in denitrification that are more similar in timing to Greenland temperature changes. In addition, the interpretation of observed variations in detrital elements from the Gulf of Tehuantepec highlights latitudinal displacements of the ITCZ that are consistent with those observed in the Cariaco Basin in Venezuela. Bulk P concentrations from both cores suggest that although phosphorite formation in the ETNP during interstadials is not as widespread as previously thought, the very high accumulation rates in the Gulf of Tehuantepec and Mazatlan Margin lead to total Holocene phosphorus burial rates that are up to 4-5 times higher than had been estimated in previous studies. These observations lead to the argument that the ETNP may play a more important role in regulating global P budgets than was previously thought and call for an improved appreciation of the benthic microbial communities that modulate biomes at tropical latitudes.


Abstract Increased numbers of benthic predators, especially crabs, have been proposed as a factor contributing to the decline of hard clams (Mercenaria mercenaria Linnaeus, 1758) in Great South Bay, NY. The long-term trend in benthic predators in this system was examined using observations on the distribution and abundance of predators that have been collected by the Town of Islip, NY as part of an annual survey of hard clam populations. The survey began in 1978 and extends to the present and provides concurrent observations of habitat (sediment type, and presence/absence of eelgrass), and hard clam size-frequency distribution and abundance. Predator type and abundance were reported from 1978 to 1981 and 1991 to 2003, which represents one of the most comprehensive benthic predator data sets currently available for any estuarine system. The annual averages of predator abundance in the survey area primarily show interannual fluctuations in abundance. Xanthid crabs (mud crabs, primarily Dispanopeus sayi Smith, 1869) were the numerically dominant predator in the system; blue crabs (Callinectes sapidus Rathbun, 1895) appeared in the late 1990s. Hard clam abundance has declined by 44% since the early 1990s. An Empirical Orthogonal Function (EOF) Analysis of the predator and hard clam data sets showed that fluctuations in predator abundance are: 1) mostly in phase over the survey region and 2) dominated by year-to-year fluctuations in abundance. The EOF results for the hard clams show that hard clam abundance fluctuations are: 1) in phase over the survey region and 2) dominated by a decreasing trend in abundance over the time series. The primary EOF modes essentially were uncoupled, which implies no strong predator-prey interactions between the predators and hard clams. By inference, increasing predator abundance does not appear to be a primary factor producing the long-term decline in hard clam populations. Predation pressure per recruit may still have increased because of declining hard clam population abundance and the concomitant decline in recruitment.


Background: Modified Ponticelli regimen (mPR), consisting of cyclical steroids and cyclophosphamide, is the most established therapy for primary membranous nephropathy (MN). Yet, the potential toxicity of this treatment regimen poses a significant concern. Objectives: The aim of this study was to assess the efficacy and safety of a modified version of the conventional mPR for primary MN using lower-than-standard dose pulse steroids. Patients and Methods: This was a retrospective single-center analysis of patients admitted between January 2008 to December 2017. All treatment-naive patients with biopsy-proven primary MN treated with a lower-than-standard dose pulse steroid-based modification of the conventional mPR (intravenous pulse of 500 mg methyl-prednisolone, instead of 1000 mg) were included. We report the remission rates at the end of 6 months (both complete and partial), relapses and adverse effects of treatment at the end of follow-up. Results: A total of 41 individuals were included. Of 31 individuals who completed six months of treatment (six were lost to follow-up, while four discontinued immunosuppression due to infections), 71% (n=22) responded to treatment [complete remission in 25.8% (n=8), partial remission in 45.2% (n=14)]. Most common complications detected throughout the treatment were steroid induced diabetes mellitus in 40% (n=14/35), infections in 25.7% (of which immunosuppression was discontinued for four participants), and leucopenia in 8.5% (n=3/35). Relapses were seen in 29% (n=9) during follow-up (mean follow-up period: 36 months). Conclusions: The modified- 'modified Ponticelli' regimen with lower-than-standard dose intravenous steroids and cyclophosphamide was efficient in attaining remission in primary MN.


This research seeks to explore the relationship between informality and inclusive growth in sub-Saharan Africa, with a particular focus on South Africa. South Africans typically hold one of two opposing views on the informal sector. The first is that informality should be encouraged as an under-utilised source of new employment; the second is that it should be discouraged as an inferior source of employment. The central research question is therefore: "Do informal labour markets promote or constrain inclusive growth?" In order to examine the hypotheses, we use three different methodologies. Firstly, we undertake a regional evidence synthesis examining literature and case studies from the sub-Saharan Africa region. Secondly, we expand on the South African case study and examine the nature of transitions within the labour market. Thirdly, we examine to what extent income shocks may impact the likelihood of engagement within the informal sector.


The preparation of single photons in a pure quantum state is a subject of great interest in physics, enabling the control of light at an unprecedented level. The ease with which certain degrees of freedom of photon states, such as polarisation, can be manipulated, along with the inherent resilience of photons to decoherence, makes them well suited for use as qubits. Recent rapid developments in the transmission and processing of quantum information, as well as the likely technological impact of potential real-world applications such as quantum cryptography and quantum computation, mean that the demand for high performance single photon sources is likely to increase in the near future. One approach to producing single photon states, which are known to be in a well-defined spatio-temporal mode without destructively measuring them, is to take advantage of nonlinear optics. Nonlinear processes can be used to realise frequency conversion by generating a single, correlated pair of photons from an intense pump laser source. The detection of one of the photons from a pair can then be used to indicate the presence of the other photon in the pair, a procedure known as heralding. This thesis describes the development of a source of heralded single photons at 1550 nm, generated directly in the core of a photonic crystal fibre (PCF). By taking advantage of low loss fibre components for the required spectral filtering of the generated photon state, a heralding fidelity of 52% was achieved. The source was designed to be used with a picosecond pulsed fibre laser, making it relatively low cost and maintenance free. With 148 mW of average pump power a heralded output photon rate of 6.4 × 104 s-1 was observed, demonstrating the brightness of the source. The purity of the generated single photons was established by measuring non-classical interference, with a visibility of 70%, between the photons output from this source and a source based on a PPLN waveguide. The fabrication of a series of birefringent PCFs for the generation of spectrally pure state photons at 1550 nm is also discussed. These PCFs will be useful for incorporation in the next generation of high performance, fibre-based photon sources.


The first monitoring of isotope composition of precipitation in Slovenia was performed in the period 1972–1975 in the frame of Ljubljanica River drainage basin investigations while regular and systematic monitoring began in 1981 in Ljubljana. The Slovenian Network of Isotopes in Precipitation (SLONIP) monitoring network has been extended during the last few decades to more than 30 different locations countrywide, mostly in the frame of short-term research projects performed by different institutions and the data were used in many hydrological, hydrogeological, climatological investigations and studies related to food authentication. SLONIP is still not a part of a national monitoring program such as that operating in European countries and a national isotope in precipitation database as well as a dedicated precipitation isoscape based on coherent periods are still not available for a region under the influence of mixing continental, Alpine and sub-Mediterranean climate. Based on the review of the history of isotope in precipitation investigations performed in Slovenia in the period 1981–2015 we summarized information about sampling, analytical methods used and basic isotope data for a particular sampling location, identified the main gaps in the past research and presented general recommendations for future work in the frame of SLONIP. Next step is to collect and evaluate available data before their compilation into a Slovenian 'ready-to-use' precipitation isotope database, which will be further used for geostatistical treatment to evaluate the distribution patterns useful for hydrological, climatological and food authentication applications. The longest precipitation data sets (delta2H, delta18O, 3H) exist for Ljubljana and Portorož and are also part of the Global Network of Isotopes in Precipitation (GNIP). The data were published and evaluated until the end of 2010 . Therefore, the main purpose of this paper is to present results concerning the stable isotope composition of precipitation at Ljubljana and Portorož in relation to basic meteorological parameters (e.g. air temperature, precipitation amount) for the period 2011–2015 and to compare them with the past records. Mean annual temperatures (T) and annual amounts of precipitation (P) varied considerably (i.e. 1°C difference in annual T and >700 mm in P) in the period 2011–2015 at both stations. The temperatures were on average higher than in the past, while the precipitation decreased considerably at Portorož but was similar as long-term mean at Ljubljana. The mean values for delta2H and delta18O, weighted by precipitation amount at Ljubljana (–56.9 ‰ and –8.45 ‰) and Portorož (–41.3 ‰ and –6.45 ‰) are similar to those observed for previous periods but indicate slightly more positive values in recent period. The change is more pronounced in the deuterium excess weighted mean values that amount to 10.7 ‰ and 10.3 ‰ for Ljubljana and Portorož, respectively, being 0.4 and 1.7 ‰ higher than those obtained for the period 2007–2010. The precipitation weighted least square regression local meteoric water lines result in delta2H = (7.77 ± 0.13)×delta18O + (9.00 ± 1.14) for Ljubljana and delta2H = (7.56 ± 0.18)×delta18O + (7.25 ± 1.21) for Portorož. Both lines indicate changes in slope and intercept that have to be inspected into more detail.


BACKGROUND
Reducing heart rate (HR) in CT angiography of the coronary arteries (CTACor) is critical to image quality. The effectiveness of calcium channel blockers as alternatives for patients with contraindications to beta-blockers has not been established.

OBJECTIVES
To compare the efficacy in the reduction of HR and RR variability of metoprolol and diltiazem in CTACor.

METHODS
Prospective, randomized, open study that included patients with clinical indication of CTACor in sinus rhythm with HR > 70 bpm and no use of agents that could interfere with HR. Fifty patients were randomized to the groups: metoprolol IV 5-15 mg or up to HR ≤ 60 bpm (M), and diltiazem IV 0.25 to 0.60 mg/kg or up to HR ≤ 60 bpm (D). Blood pressure (BP) and HR were measured at baseline, 1 minute, 3 minutes and 5 minutes after the agents, at the acquisition and after CTACor.

RESULTS
HR reduction in absolute values was higher in group M than in group D (1, 3, 5 min, acquisition and post-test). The percentage reduction of HR was significantly higher in group M only 1 min and 3 min after the start of the agents. There was no difference in 5 min at acquisition and after examination. The percentage RR variability in group D was lower than that in group M during acquisition (RR variability/mean HR of acquisition). A single case of AVB, 2:1 Mobitz I occurred, which was spontaneously reverted (group D).

CONCLUSION
We conclude that diltiazem is an effective and safe alternative to beta-blockers in the reduction of HR when performing computed tomography angiography of coronary arteries.


Dietary protein restriction and fish oil supplementation (MaxEPA) have been reported to have favourable effects on the remnant nephron model. In the present study female Munich-Wistar rats underwent 5/6 renal ablation (60 rats) or sham surgery (20 rats). The renal ablation rats were randomized one week post-surgery to receive a diet that contained either regular laboratory diet (RLD), 6% low protein diet (LPD) or 24% fish oil diet (FOD) supplementation. Mortality rates at 10 and 20 weeks post-surgery were not different amongst the RLD, LPD or FOD renal ablation cohorts. However the G.F.R. was significantly preserved in the FOD and LPD versus the RLD renal ablation rat groups. Both the LPD and FOD decreased albuminuria and gammaglobulinuria but LPD was more effective. Both dietary interventions prevented glomerulosclerosis but only LPD significantly reduced mesangial expansion. The FOD diet prevented intraglomerular fibrin formation and the LPD had no effect. The dyslipidemia noted at 20 weeks in the renal ablation group was significantly abrogated by both FOD and LPD, although only LPD prevented the heavy proteinuria. The LPD rats gained significantly less weight than the FOD and RLD cohorts. FOD exerted a significantly greater effect on blood pressure reduction than the LPD and also produced significant changes in the renal tissue phospholipids. These results indicate that protein restriction and fish oil supplementation preserve renal structure and function in the remnant nephron model but have different effects on mechanisms known to be co-factors in the progressive renal injury.


Acousto-ultrasonic input-output characteristics for contact-type transmitting and receiving transducers coupled to a thin orthotropic composite plate are analyzed in this paper. By introducing the point source/point receiver assumption, the governing equations of the problem, which relates to wave generation, wave propagation and wave reception, are first established. Using the multiple integral transform method, contour integration technique and some complex function theories, a spectral analysis method which is completely different from the present wave path tracing method for this problem is developed. From this approach, the spectral response of the normal contact force between the receiving transducer and the plate, due to an arbitrary input interrogation pulse excited by the transmitting transducer, is expressed in explicit form. Based on this, some physical properties involved with the output of the receiver are examined in the frequency domain. Finally, combining the fast Fourier transform (FFT) technique, some time domain numerical results are calculated to show the input-output characteristics of the AU system considered.


The effects of childhood poverty and hunger in India are systemic. Almost half of the county's children are classified as malnourished—and 47 percent of those under the age of three are underweight (UNICEF, 2014). This thesis analyzes how Indian's English-language press has portrayed this widespread health issue during the past two years. This thesis also examines how the framing in the English-language press relates to the frames in the Hindi-language press. In light of framing theory, the study has found that the press used three principal media frames to portray child hunger. One frame focused on socioeconomic disparities, a second on geographic differences, and the third on government interventions. These frames, however, did not address more complex realities identified by developmental studies literature as contributing to the seemingly untouchable crisis of childhood poverty and hunger. INDEX WORDS: Framing, Developmental journalism, Sensationalism, India, Child hunger UNTOUCHABLE HUNGER: FRAMING OF CHILDHOOD POVERTY IN INDIA, MAY 2012-APRIL 2014


Soil organic carbon (SOC) is the percentage measure of carbon (C) derived from living organisms in soil. Stability of soil organic matter (SOM) can be defined in terms of how easily C and nitrogen in the SOM can be decomposed. Due to the implications in the permanence of SOC during sequestration there is scientific interest in fractionation of SOM into different fractions. A large number of SOM fractionation procedures have been developed to distinguish between SOM to study whether it is liable or recalcitrant to activities of soil microbes. There are physical and chemical fractionation techniques. The former is based on particle size and density of soil samples or combination of the two, and the latter on the reaction of chemical on SOM for the separation of stable SOC. Each fraction of SOC in the laboratory can be commonly determined using wet oxidation by Walkley-Black method and dry combustion by LECO CN Analyzer. With the advancement in chemometric statistical techniques; faster, robust, cheaper and non-destructive methods are emerging. The chemometric statistical techniques do not require any reagents for analysis compared with the wet oxidation or dry combustion methods. Thus, these emerging techniques are highly attractive for studies where a large number of analyses are required. For in situ measurement of SOC, spectral reflectance technology is developed to facilitate instant measurement in the field using the sensors or by remote sensing.


The prime concern by the Nigerian state in the management of the oil conflicts in the Niger Delta has been to maximise oil revenues. What is probably most confounding about this strategy is the evolving tendency to twist and treat every conflict in the Niger Delta, including some episodic 'epi-oil' conflicts abetted or orchestrated by the state itself, as oil conflicts. In other words, there is a tendency on the part of the state to wittingly 'oilify' some apparently extra-oil conflicts. Compared to other regimes before it, the present civilian administration has probably contributed most to the fast-tracking of this evolving phenomenon. This article unravels and analyses the evolving politics of oilification of extra-oil conflicts in the Niger Delta, its underlying rationale and consequences. Oilification, as the study demonstrates, is yet another in the series of dangerous contradictions engendered by the Nigerian state. How this and other dangerous contradictions could possibly be solved is a research conundrum for the relevant cognoscenti of state-society relations and conflicts in Nigeria. But would the Nigerian state take on board any useful and promising solutions materialising from such studies? This is most unlikely in the present conjuncture given the prevailing configuration of interests in the state.


Similar to the evolutionary process for living organisms, marine navigation systems are becoming increasingly complex and sophisticated. Both by design and function, shipboard and shore-based navigation systems are no longer individual equipment components operating independently. Instead, the trend is toward integration, data fusion and synergy. One example of this are new Performance Standards being considered by IMO to achieve a "harmonized" presentation of all navigation-related information on the display of an integrated navigation system (INS). Unlike a dedicated display for ECDIS or radar, the new INS displays will be a task-oriented composite presentations that enable the mariner to configure the display for an operational situation by selecting specific chart, radar, radar plotting aids (ARPA) and AIS information that is required for the task-at-hand. This paper gives a brief overview of the trend toward the development of INS. In addition to a brief summary of IMO performance standards for navigation equipment/systems, specific mention is made about a BSH (Germany) report on the "Functional Scope and Model of INS." A discussion is provided about the challenges of providing navigation safety information that goes beyond traditional boundaries of products and services. Currently, many agencies continue to produce individual products and services on a component basis. Hydrographic offices grapple with trying to provide multiple products and services for paper charts, raster navigational charts (RNCs) and electronic navigational charts (ENCs) while a same time, Coast Guard and Maritime Safety agencies focus on improving Aids-to-Navigation (AtoN), Vessel Traffic Services (VTS), AIS networks -- and more recently, port security. In some respects, the continued concentration on separate products and services represents an organizational reluctance to change. This in turn, results in a fragmented, sub-optimal approach to the safety-of-navigation caused by the inability to provide mariners with "seamless" information at reasonable cost. In particular, hydrographic offices must be willing to recognize that chart information can no longer be considered to be separate, individual products. When it comes to the provision and use of chart-related information for use in an INS, the focus needs to shift to what information is actually desired, how it will be provided, what other information it will be used with, and whether it is truly up-todate.


Abstract Sodium stibogluconate (SSG, Pentostam) and meglumine antimoniate (MA, Glucantime) are two antimonials that are widely used to treat cutaneous leishmaniasis (CL), but the relative efficacies of these treatments are not clear. The aim of this study is to compare the efficacy of intralesional SSG with intralesional MA therapy in the treatment of CL. One month after completion of the therapy, 1431 of 1728 patients (82%) who received intralesional MA showed complete clinical cure compared to 1157 of 1728 patients (67%) in the SSG group. Patients who did not respond to the first round of therapy were re-administered the same treatment but with twice weekly injections. Following completion of the second course of therapy, 237 of 297 patients (80%) in the MA group and 407 of 561 patients (72%) in the SSG group healed their lesions by 1-month post-treatment. At both times, the differences in cure rates between MA and SSG groups were statistically significant (p < 0.05). Cure rates in the MA group were always significantly higher than SSG groups irrespective of other parameters including age, gender, lesion site and type of lesion. Intralesional MA is more effective than intralesional SSG in the treatment of CL.


The term 'schlieren' describes angular deflection of a light ray when it passes through a fluid region characterized by refractive index inhomogeneities. These inhomogeneities in the marine environment are generally caused by density variations, i.e. salinity and temperature anomalies. The influence of schlieren on transmissometers and the in situ particle sizer LISST-Deep of Sequoia Scientific are examined in the Danube delta during October 2007. A seasonal pycnocline driven mainly by an intense temperature gradient was identified as a major hydrological feature. It was associated with high buoyancy frequency values and minor changes of the refractive index of seawater. Measurements of two 25-cm path-length transmissometers (660 nm and 470 nm) showed distinguishable peaks at the pycnocline. LISST also uses a 5-cm transmissometer (670 nm), which proved to be very sensitive in both cases. This is mainly due to its very small acceptance angle, which enables enhanced light scattering outside the lens, thus increasing beam attenuation. Subsequently, LISST falsely predicts abundance of large particles within the pycnoclines. A buoyancy frequency N of 0.01 s -1 is the new proposed threshold for schlieren occurrence.


Gareth was born in 1982 as a normal delivery at term, birth weight 2.92 kg, and had normal Apgar scores following an uneventful pregnancy. Five hours after delivery he was hypothermic and was found to have a blood glucose of 1.0 mmol/l. The hypoglycaemia resolved with continuous nasogastric feeds followed by three-hourly bottle feeds. He was discharged from hospital three days later.

At 5 weeks of age he presented to his general practitioner (GP) with an eight-hour history of episodes of floppiness associated with a dusky complexion. There had been a one-week preceding history of coryzal illness and a cough with intermittent episodes of cyanosis. In the preceding weeks there had been poor weight gain, he had been slow to feed and had occasional non-projectile vomiting. The GP suggested that the most likely diagnosis was a viral upper respiratory tract infection but, given the history, he arranged for the baby to be admitted for further evaluation at the local hospital.

On arrival the baby was apyrexial, hypotonic and poorly perfused. Further examination revealed normal heart sounds with palpable upper limb pulses but impalpable femoral pulses, a shallow and irregular respiratory effort, and hepatomegaly of 3–4 cm with normal genitalia. There were normal spontaneous movements and no abnormal posturing. A full septic screen was performed and he was commenced on intravenous antibiotics. The microscopy and culture of the blood, urine and cerebrospinal fluid was not suggestive of infection. His initial biochemical investigations are shown in table 1.

View this table:

 Table 1
 Initial biochemical results


Aim/Purpose: This study is based on the DeLone and McLean's Information Systems Success (D & M ISS) model, which was modified to determine the success factors re-sponsible for the acceptance of an e-learning system called Canvas by students of a Nigerian University. Background: The adoption of eLearning has been under studied within the context of devel-oping countries. There have been calls in the literature for further research from a developing country perspective. This study attempts to fill this knowledge gap by investigating the factors responsible for students' adoption of eLearning in a Nigerian University. Methodology: The study was built on the premise that system quality (SQ), service quality (ServQ) and information quality (IQ) are determinants of behavioral intention to use Canvas and user satisfaction of Canvas, both of which in turn influence the actual usage of Canvas. Responses from 366 students were analyzed with AMOS 22 using structural equation model (SEM) to test the relationships be-tween the constructs of the proposed model. Contribution: The study contributes to the research gap about the paucity of studies in the adoption of eLearning in developing countries that have placed emphasis on the use of eLearning systems or on the software quality attributes of the sys-tems under investigation. Findings: The results partially supported the effect of the quality antecedents on behav-ioral intention and user satisfaction of students. There was full support for the relationship between behavioral intention and user satisfaction of students on their actual usage of Canvas. Recommendations for Practitioners: The level of significance of the constructs identified in the study will guide the formulation of strategies and methods that could further enhance the adoption of eLearning systems in developing countries, specifically Nigeria. Recommendation for Researchers: Theoretically, the study contributes to the body of knowledge on eLearning adoption by empirically validating the DeLone and McLean model in a different context, specifically sub-Saharan Africa. Future Research: Future research could investigate the factors that influence instructors' behav-ioral intentions to use eLearning applications and also the effect that the in-structors have on students' adoption of eLearning.


Network coding has recently attracted attention as a substantial improvement to packet retransmission schemes in wireless multicast broadcast services (MBS). Since the problem of finding the optimal network code maximizing the bandwidth efficiency is hard to solve and hard to approximate, two main network coding heuristic schemes, namely opportunistic and full network coding, were suggested in the literature to improve the MBS bandwidth efficiency. However, each of these two schemes usually outperforms the other in different receiver, demand, and feedback settings. The continuous and rapid change of these settings in wireless networks limits the bandwidth efficiency gains if only one scheme is always employed. In this paper, we propose an adaptive scheme that maintains the highest bandwidth efficiency obtainable by both opportunistic and full network coding schemes in wireless MBS. The proposed scheme adaptively selects, between these two schemes, the one that is expected to achieve the better bandwidth efficiency performance. The core contribution in this adaptive selection scheme lies in our derivation of performance metrics for opportunistic network coding, using random graph theory, which achieves efficient selection when compared to appropriate full network coding parameters. To compare between different complexity levels, we present three approaches to compute the performance metric for opportunistic coding using different levels of knowledge about the opportunistic coding graph. For the three considered approaches, simulation results show that our proposed scheme almost achieves the bandwidth efficiency performance that could be obtained by the optimal selection between the opportunistic and full coding schemes.


*Department, Baghdad Teaching Hospital, Iraq. **Department of Dermatology&Venereology, College of Medicine, University of Baghdad. INTRODUCTION: Melasma is a major cosmetic problem especially among dark skin women (1) , affecting almost 30% of Iraqi females in their reproductive age (2) .There ABSTRACT: BACKGROUND: Melasma is a major cosmetic problem affecting young people mainly females. There are many modalities of topical therapy but usually end with relapse. OBJECTIVE: To evaluate the efficacy and safety of 6% lactic acid cream in comparison with glycolic acid cream 6% and 12% in the treatment of melasma. PATIENTS & METHODS: This is a COHORT comparative therapeutic trial conducted in the Department of DermatologyBaghdad Teaching Hospital. Sixty patients with melasma were included in this study. They were divided into three groups; each one consisted of twenty patients. Group one treated with 6% lactic acid cream, group two with 6% glycolic acid cream, group three with 12% glycolic acid cream. Patients were evaluated clinically using wood's light & melasma area severity index score before and after therapy. Follow up was done regularly every two weeks for two months to assess the improvement and side effects. Also patients were seen monthly for 3 months after the end of treatment to see any relapse. All patients were instructed to apply the cream once at night for two months with broad spectrum sun block SPF > 30 before sun exposure. RESULTS: In group one of the study using lactic acid cream 6%, 14 patients completed the study; their ages ranged from 26-42 years, with a mean 31.9 SD 4.1 years, twelve patients (86%) were females and 2 (14%) males. The result showed that the average score before treatment was 11.45  2.9 while after treatment score changed to 5.312.71; so the improvement was 6.14, this represented a (54%) decrease and was statistically significant (p value<0.0005). No important side effects were recorded during the treatment or follow up. In group two of the study using 6% glycolic acid cream, 13 patients completed the treatment; their ages ranged from 1740 years with a mean 27.5  SD 6.8 years, all patients (100%) were females. The result revealed the mean of score before treatment was 10.56  2.77 while after treatment score became 8.36  2.85. So the average decrease was2.2 which represented (21%) decrease and it was statistically significant (p value<0.0005). No important side effects were recorded during the treatment or follow up. While In group 3 of the study using 12% glycolic acid cream,15 patients completed the study; their ages 22 to 40 years with a mean of 31.8  SD 5.3 years. Thirteen (87%) patients were females and 2 (13%) males. The result showed that the mean before treatment was 12.54  3, 4 while after treatment score changed to 6.06  2.38. So the average decrease was 6.48; this represented 52% decrease and was statistically significant (p value <0.0005). No important side effects were recorded during the treatment or follow up. The three agents were statistically significant for the treatment of melasma and there were no significant difference between 6% lactic acid cream and 12% glycolic acid cream (p value= 0.654). But there were significant difference between 6% glycolic acid cream and the others. CONCLUSION: Lactic acid cream 6% is a new, non costly, alternative effective, safe agent and as effective as 12% glycolic acid cream for the treatment of melasma. THE IRAQI POSTGRADUATE MEDICAL JOURNAL VOL. 16,NO.3, 2017


Helicobacter pylori is a bacterial pathogen that chronically colonizes the stomach of half of the human population worldwide. Infection by H. pylori can lead to the development of gastric pathologies such as ulcers and adenocarcinoma, which causes up to 800,000 deaths in the world each year. Persistent colonization by H. pylori relies on regulation of the expression of adaptation-related genes. One major level of such control is posttranscriptional regulation, which, in H. pylori, largely relies on a multiprotein molecular machine, an RNA degradosome, that we previously discovered. In this study, we established that the two protein partners of this machine are associated with the membrane of H. pylori. Using cutting-edge microscopy, we showed that these complexes assemble into hubs whose formation is regulated by free RNA and scaled with bacterial size and growth phase. Organelleless cellular compartmentalization of molecular machines into hubs emerges as an important regulatory level in bacteria. ABSTRACT Posttranscriptional regulation is a major level of gene expression control in any cell. In bacteria, multiprotein machines called RNA degradosomes are central for RNA processing and degradation, and some were reported to be compartmentalized inside these organelleless cells. The minimal RNA degradosome of the important gastric pathogen Helicobacter pylori is composed of the essential ribonuclease RNase J and RhpA, its sole DEAD box RNA helicase, and plays a major role in the regulation of mRNA decay and adaptation to gastric colonization. Here, the subcellular localization of the H. pylori RNA degradosome was investigated using cellular fractionation and both confocal and superresolution microscopy. We established that RNase J and RhpA are peripheral inner membrane proteins and that this association was mediated neither by ribosomes nor by RNA nor by the RNase Y membrane protein. In live H. pylori cells, we observed that fluorescent RNase J and RhpA protein fusions assemble into nonpolar foci. We identified factors that regulate the formation of these foci without affecting the degradosome membrane association. Flotillin, a bacterial membrane scaffolding protein, and free RNA promote focus formation in H. pylori. Finally, RNase J-GFP (RNase J-green fluorescent protein) molecules and foci in cells were quantified by three-dimensional (3D) single-molecule fluorescence localization microscopy. The number and size of the RNase J foci were found to be scaled with growth phase and cell volume as previously reported for eukaryotic ribonucleoprotein granules. In conclusion, we propose that membrane compartmentalization and the regulated clustering of RNase J-based degradosome hubs represent important levels of control of their activity and specificity. IMPORTANCE Helicobacter pylori is a bacterial pathogen that chronically colonizes the stomach of half of the human population worldwide. Infection by H. pylori can lead to the development of gastric pathologies such as ulcers and adenocarcinoma, which causes up to 800,000 deaths in the world each year. Persistent colonization by H. pylori relies on regulation of the expression of adaptation-related genes. One major level of such control is posttranscriptional regulation, which, in H. pylori, largely relies on a multiprotein molecular machine, an RNA degradosome, that we previously discovered. In this study, we established that the two protein partners of this machine are associated with the membrane of H. pylori. Using cutting-edge microscopy, we showed that these complexes assemble into hubs whose formation is regulated by free RNA and scaled with bacterial size and growth phase. Organelleless cellular compartmentalization of molecular machines into hubs emerges as an important regulatory level in bacteria.


The Parkinson's disease–associated protein α-synuclein binds to the mitochondrial protein import receptor TOM20, which causes downstream impairment of mitochondrial function. α-Synuclein disrupts the mitochondrial protein import business α-Synuclein accumulation and mitochondrial dysfunction are central to the pathogenesis of most forms of Parkinson's disease and appear to intersect, but how the two are related to each other has remained elusive. Now, Di Maio and colleagues report that specific forms of wild-type α-synuclein, such as oligomeric and dopamine-modified forms, but not the monomeric or fibrillar forms, bind with high affinity to the mitochondrial receptor TOM20. This results in impaired import of proteins required for mitochondrial function and leads to senescence of mitochondria, which show reduced respiration and increased production of reactive oxygen species. This study also highlights potential ways to prevent this deleterious interaction and its downstream consequences. α-Synuclein accumulation and mitochondrial dysfunction have both been strongly implicated in the pathogenesis of Parkinson's disease (PD), and the two appear to be related. Mitochondrial dysfunction leads to accumulation and oligomerization of α-synuclein, and increased levels of α-synuclein cause mitochondrial impairment, but the basis for this bidirectional interaction remains obscure. We now report that certain posttranslationally modified species of α-synuclein bind with high affinity to the TOM20 (translocase of the outer membrane 20) presequence receptor of the mitochondrial protein import machinery. This binding prevented the interaction of TOM20 with its co-receptor, TOM22, and impaired mitochondrial protein import. Consequently, there were deficient mitochondrial respiration, enhanced production of reactive oxygen species, and loss of mitochondrial membrane potential. Examination of postmortem brain tissue from PD patients revealed an aberrant α-synuclein–TOM20 interaction in nigrostriatal dopaminergic neurons that was associated with loss of imported mitochondrial proteins, thereby confirming this pathogenic process in the human disease. Modest knockdown of endogenous α-synuclein was sufficient to maintain mitochondrial protein import in an in vivo model of PD. Furthermore, in in vitro systems, overexpression of TOM20 or a mitochondrial targeting signal peptide had beneficial effects and preserved mitochondrial protein import. This study characterizes a pathogenic mechanism in PD, identifies toxic species of wild-type α-synuclein, and reveals potential new therapeutic strategies for neuroprotection.


This study leverages a survey experiment in the lead up to the 2016 U.S. presidential election to evaluate how partisan biases, poll results, and their methodological quality interact to shape people's assessments of polling accuracy and electoral expectations. In a nationally representative sample, we find that individuals disproportionately find polls more credible when their preferred candidate is leading. Partisan biases are mitigated when the polls themselves vary in objective indicators of quality: while more educated respondents are more likely to identify high-quality polls accurately, low education respondents' bias was reduced when they encountered polls with varying methodological quality. Finally, these moderators influence respondents' electoral expectations as well. We discuss the implications for journalistic coverage of polls, public opinion, and political polarization.


From 1989 to 2001, wealth in real terms increased overall among U.S. families. But characterizing distributional changes is much more complex; it depends on the specific questions asked. For example, there is evidence both from Forbes data on the 400 wealthiest Americans and from the SCF, which explicitly excludes families in the Forbes list, that wealth grew relatively strongly at the very top of the distribution. At the same time, the share of total household wealth held by the Forbes group rose. However, while the point estimate of the share of total wealth held by the wealthiest 1 percent of families, as measured by the SCF, also rose, the change is not statistically significant. In 2001, the division of wealth observed in the SCF attributed about a third each to the wealthiest 1 percent, the next wealthiest 9 percent, and the remaining 90 percent of the population. The paper decomposes wealth holdings and distributional shifts in a variety of other ways. Particular attention is given to families with negative net worth, families of older baby boomers, and African American families.


In the late 1980s, American independent film broke out of the tiny "art houses" (specialty theaters) of a few major American cities and became a much stronger presence in American public culture. Independent filmmakers see themselves as challenging the hegemony of Hollywood, eschewing entertainment—fantasy, pleasure, happy endings—and offering instead harsh and "edgy" stories about life in contemporary society. The present article draws on interviews, panel discussions, filmmaker Q & As, and other contexts in which independent film people talk about what they are trying to do: to make what one indie producer called "movies that matter."


Economists and political scientists have long debated the nature of the process that determines government taxation and service levels in a democracy. During the 1980s, the role of referenda in determining city and town property taxes, and hence local spending, increased dramatically in Massachusetts. This article uses recent Massachusetts experience to examine the degree to which citizens "get what they want" from the local public sector and what it is they seem to want. ; The passage of Proposition 21/2 in November 1980 signalled both a shift in statewide voter sentiment against local officials' previously "unfettered" decision-making and a change in rules, making it more difficult for localities to raise property taxes, their only major local revenue source. The impact has been uneven across communities. Nonetheless, until late in the decade, both sizable additions to local aid and a booming real estate market allowed many communities' expenditures to grow moderately without bumping against their Proposition 2½ limits.


This paper discusses how to avoid plagiarism in a research paper. Avoiding plagiarism is part of a scientific writing ethic that always stated in any publication. Every writer should pay attention to their papers submitted to a journal or a scientific forum that they are free from unethical conduct. Writing a research paper needs overall accuracy especially in avoiding plagiarism in the paper that is to be published in a journal or to be presented at a certain scientific meeting, seminar or symposium. It is based on writers' experience as a paper writer as well as a journal reviewer. The first application that the writers use is 'checker', a Mac computer application, used to check spelling and grammar. It assists the writers to check how misspelling and an ungrammatical inaccuracy in the writers' papers. The second free application is 'plagiarism checker'. Checking originality of a paper is essential and it is not too difficult to do today. It is freely accessible that plagiarism checker can be used to check how original the paper is. By visiting "Google" then write down 'plagiarism checker', it will appear 'smallseatools' and then the writers could choose and check how original the paper is. This application is freely accessed and helps immensely to check how original a paper is and how far a paper is free from plagiarism. The unoriginal phrase will be underlined and marked red and finally will be shown how inimitable the paper is. Plagiarism scan report which consists of the date of the report, plagiarism status, total words and total characters can be downloaded.


The Gas Technology Institute (formerly the Gas Research Institute) sponsors a comprehensive flow measurement research, development, and commercialization (RD&C) program aimed at improving natural gas metering performance in the field. This paper summarizes some of the recent accomplishments of the research program at the Gas Technology Institute (GTI) Metering Research Facility (MRF), a high-accuracy natural gas flow calibration laboratory capable of simulating a wide range of operating conditions for the industry's research, calibration, and testing needs. The MRF, located at Southwest Research Institute (SwRI) in San Antonio, Texas, supports a variety of GTI-sponsored research and third-party test and calibration activities. Major research initiatives currently being funded by GTI (formerly known as the Gas Research Institute or GRI) include ultrasonic and turbine flow meter research and gas sampling methods research. Over the past year, GTI has also funded Coriolis flow meter research and the development of a new energy flow rate meter concept. Through its portfolio of projects addressing priority research needs, the GTI natural gas measurement program provides significant benefits to the natural gas industry.


A groundwater flow model was developed to simulate groundwater extraction from the public water supply source of the City of Kikinda. The hydrodynamic model includes the municipal groundwater source of Kikinda (Sumice and the Jezero Well), but also an extended area where there are groundwater sources that provide water supply to three factories: (MSK, TM and LŽT - Kikinda). Hydrodynamic modeling, based on the numerical method of finite differences will show the groundwater balance of the sources in the extended area of Kikinda. The impact of the industrial water sources on the regime of the public water supply source will also be assessed. The radius of influence of the groundwater source is determined by simulating the travel of conservative particles over a period of 200 days.


ABSTRACT Cord blood is widely used as surrogate tissue in epigenome-wide association studies of prenatal conditions. Cell type composition variation across samples can be an important confounder of epigenome-wide association studies in blood that constitute a mixture of cells. We evaluated a newly developed cord blood reference panel to impute cell type composition from DNA methylation levels, including nucleated red blood cells (nRBCs). We estimated cell type composition from 154 unique cord blood samples with available DNA methylation data as well as direct measurements of nucleated cell types. We observed high correlations between the estimated and measured composition for nRBCs (r = 0.92, R2 = 0.85), lymphocytes (r = 0.77, R2 = 0.58), and granulocytes (r = 0.72, R2 = 0.52), and a moderate correlation for monocytes (r = 0.51, R2 = 0.25) as well as relatively low root mean square errors from the residuals ranging from 1.4 to 5.4%. These results validate the use of the cord blood reference panel and highlight its utility and limitations for epidemiological studies.


The complexity of current computer systems has led the software engineering, distributed systems and management communities to look for inspiration in diverse fields, e.g. robotics, artificial intelligence or biology, to find new ways of designing and managing systems. Hybridization and combination of different approaches seems to be a promising research field of computational intelligence focusing on the development of the next generation of intelligent systems. A manufacturing system has a natural dynamic nature observed through several kinds of random occurrences and perturbations on working conditions and requirements over time. For this kind of environment it is important the ability to efficient and effectively adapt, on a continuous basis, existing schedules according to the referred disturbances, keeping performance levels. The application of Meta-Heuristics to the resolution of this class of dynamic scheduling problems seems really promising. In this article, we propose a hybrid Meta-Heuristic based approach for complex scheduling with several manufacturing and assembly operations, in dynamic Extended Job-Shop environments. Some self-adaptation mechanisms are proposed.


In many online environments, such as massive open online courses and crowdsourcing platforms, many people solve similar complex tasks. As a byproduct of solving these tasks, a pool of artifacts are created that may be able to help others perform better on similar tasks. In this paper, we explore whether work that is naturally done by crowdworkers can be used as examples to help future crowdworkers perform better on similar tasks. We explore this in the context of a product comparison review task, where workers must compare and contrast pairs of similar products. We first show that randomly presenting one or two peer-generated examples does not significantly improve performance on future tasks. In a second experiment, we show that presenting examples that are of sufficiently high quality leads to a statistically significant improvement in performance of future workers on a near transfer task. Moreover, our results suggest that even among high quality examples, there are differences in how effective the examples are, indicating that quality is not a perfect proxy for pedagogical value.


ABSTRACT The ability of hatchling and juvenile turtles to thermoregulate, as evidenced by selection of preferred temperatures in thermal gradients, is an important factor influencing fitness. Previous studies in laboratory thermal gradients suggest that most young turtles select warm temperatures (25°–33°C) within a narrow range. Confounding factors affecting microhabitat selection, such as predator avoidance, foraging, or social interaction, may influence thermal preference in some species, particularly softshell turtles (Apalone spp.) that frequently bury in the substrate to remain cryptic. We analyzed temperature selection of juvenile Apalone spinifera in an aquatic thermal gradient of 15°–30°C with either gravel, sand, or a combination of sand and no substrate. Across all substrate treatments in the gradient tests, hatchlings selected the warmest temperature available (30°C: 56.1% of observations) and avoided the 2 coldest temperatures (15°C: 5.3%; 18°C: 3.6%). Turtles relocated between chambers more often in control tests than when a gradient was present and fewer observations involved a chamber relocation in control tests. In gradient tests, chamber temperature significantly influenced selection, and the interactive effect of temperature and substrate was significant. We observed turtles more frequently in 30°C in tests conducted with a sand substrate than with a gravel substrate or without a substrate. In tests conducted with sand in the 4 coolest chambers only, turtles chose the warmest temperature with a sand substrate more often than all other temperatures, except 30°C. Our results indicate that hatchling A. spinifera can effectively detect temperature differences and select preferred temperatures within at least a 3°C range and that substrate type may affect selected temperature.


Title of Dissertation: EXPERIMENTAL, COMPUTATIONAL AND, THEORETICAL ANALYSIS OF THE GROEL/GROES CATALYTIC CYCLE Nicholas Crane Corsepius Doctor of Philosophy, 2014 Dissertation Directed By: Professor George H. Lorimer Department of Chemistry and Biochemistry Biochemistry Graduate Program The GroEL/GroES system is among the best characterized molecular chaperonins, having been the focus of numerous studies since its discovery just over 40 years ago. There are several aspects of the chaperonin's catalytic cycle that have been thoroughly established, such as the positive intra-ring and negative inter-ring cooperativity that characterizes the binding of ATP, or the concerted domain movements within a ring that constitute the T → R allosteric transition. However, there are still several aspects of the GroEL/GroES catalytic cycle that are still not well understood, and the focus of this work is to address several of them. The results presented throughout this dissertation differ, sometimes drastically, from conventional wisdom, providing a new framework for the investigation of GroEL/GroES catalysis. The work presented here contains several new insights into the GroEL/GroES catalytic cycle. The complicated nature of the interaction between GroEL and its substrate proteins (SPs) has previously prevented quantitative analysis of the role that SP binding plays in the cycle. The problem is circumvented in this work by application of an SP surrogate that simultaneously mimics the effects of bound SP and allows for the quantification of allosteric states. Development of the system leads to the first ever quantification of the role of SP in the catalytic cycling of GroEL. In addition to cycle features that had not been previously addressed, there are several parts of the catalytic cycle that have simply been overlooked throughout the years or unduly simplified in previous analysis. The hydrolysis of ATP within a ring and the release of ADP from a ring are often characterized as concerted events. Both steps are crucial to the cycling of the GroEL/GroES system, and are thoroughly investigated in this work. Thorough examination reveals that neither step is well-characterized as a concerted process. Pre-steady state kinetic analysis demonstrates that hydrolysis of ATP occurs stochastically, each subunit hydrolyzing ATP independently and randomly. Pre-steady state kinetic analysis also reveals that ADP release is a multi-step process. Insight into the steps preceding/ accompanying ADP release are found in molecular dynamics (MD) simulations of the R → T allosteric relaxation. These simulations demonstrate the allosteric relaxation proceeds through a highly asymmetric series of states. Furthermore, the relaxation path taken by subunits can be described as exhibiting dynamic negative-cooperativity. The analysis implicates the allosteric relaxation as the trigger that allows the GroEL/GroES system to effectively respond to environmental stimuli. The last topic addressed concerns the role of the GroEL/GroES2 symmetric complex and the mechanism governing its cycling. It has long been assumed that a ring must hydrolyze all seven ATP before it can discharge GroES. This assumption is challenged by new insight into the stochastic mechanism of ATP hydrolysis. The analysis presented in this paper undermines the idea of all-or-none cycling and builds a quantitative relationship between the nucleotide distribution in a complex and its propensity to dissociate. Experimental, Computational and, Theoretical Analysis of the GroEL/GroES Catalytic Cycle Nicholas Crane Corsepius Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park, in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2014 Advisory Committee: Professor George H. Lorimer, Chair Professor Dorothy Beckett Professor Edward Eisenstein Professor David Fushman Professor Devarajan Thirumalai © Copyright by Nicholas Crane Corsepius 2014


Data mining is the discovery of patterns and regularities from large amounts of data using machine learning algorithms. This can be applied to object recognition using image processing techniques. In fruits and vegetables production lines, the quality assurance is done by trained people who inspect the fruits while they move in a conveyor belt, and classify them in several categories based on visual features. In this paper we present an automatic orange's classification system, which uses visual inspection to extract features from images captured with a digital camera. With these features train several data mining algorithms which should classify the fruits in one of the three pre-established categories. The data mining algorithms used are five different decision trees (J48, Classification and Regression Tree (CART), Best First Tree, Logistic Model Tree (LMT) and Random Forest), three artificial neural networks (Multilayer Perceptron with Backpropagation, Radial Basis Function Network (RBF Network), Sequential Minimal Optimization for Support Vector Machine (SMO)) and a classification rule (1Rule). The obtained results are encouraging because of the good accuracy achieved by the classifiers and the low computational costs.


What are the roles necessary to effective data management and what kinds of expertise are needed by the researchers and data specialists who are filling those roles? These questions were posed at a workshop of data creators and curators whose delegates challenged the DCC and RIN to identify the training needs and career opportunities for the broad cohort that finds itself working in data management – sometimes by design but more often by accident. This paper revisits previous investigations into the roles and responsibilities required by a "data workforce", presents a representative spectrum of informed opinion from the DCC Research Data Management Forum, and makes some recommendations for raising capability, capacity and status.


Estate of woman and of chief by H.E. Ntsanwisi (written in Tsonga). Forms part of the van Warmelo Collection housed at the University of Pretoria.


ABSTRACT Aim: Palbociclib (P), a selective oral cyclin-dependent kinase 4/6 inhibitor that blocks G1/S cell cycle progression, is in phase 2 and 3 clinical trials across multiple oncology indications. P has low solubility and high permeability. This completed phase 1 study estimated the effect of food on P bioavailability. Methods: This randomized, open-label, 4-sequence, 4-period crossover study (NCT01904747) in 28 healthy adult volunteers estimated the relative bioavailability of single-dose P 125 mg (free base capsule) administered 30 min after a high fat/calorie meal, 30 min after a low fat/calorie meal, or between 2 moderate fat/standard calorie meals (1 h after/2 h before) versus after fasting ≥10 h overnight (washout: ≥10 d between study periods). No food was allowed ≥4 h postdose (all conditions except moderate fat meal). Pharmacokinetic (PK) samples were collected predose and serially up to 144 h postdose; P concentrations were measured using validated high-performance liquid chromatography tandem mass spectrometry. PK data were analyzed using a non-compartmental approach based on a mixed effects model. Results: Time to maximum P concentration (Tmax) and terminal plasma half-life (t1/2) values were similar across fed and fasted conditions (median Tmax: 8 h, all; mean t1/2: 22.03–23.90 h). Relative to the fasted condition, ratios of adjusted geometric means for high fat, low fat, and moderate fat conditions were 121%, 112%, and 113%, respectively, for AUCinf and 138%, 127%, and 124%, respectively, for Cmax; the slight increase in exposure in the fed versus fasted conditions was driven mainly by a subgroup of subjects (n = 3) with significantly lower exposure in the fasted condition. PK variability (% coefficient of variation) was reduced in the fed (AUCinf, 23%–27%; Cmax, 21%–24%) versus fasted (AUCinf, 39%; Cmax, 73%) conditions. In a supplemental analysis excluding the 3 subjects with significantly lower exposure in the fasted condition, food intake did not affect P exposure, and PK variability was similar across fed and fasted conditions. Conclusions: Overall, P exposure was marginally affected, but PK variability was greatly reduced, in the fed versus the fasted condition. Thus, P should be administered with food. Disclosure: A. Ruiz-Garcia: Employment: Pfizer Inc Stock ownership: Pfizer Inc.; A. Plotka: Employment: Pfizer Stock ownership: Pfizer; S. Pawlak: Speakers' bureau: Pfizer Employment: Pfizer Stock ownership: Pfizer; M. O'Gorman, S. Nidadavolu and S. Phillips: Employment: Pfizer; M. Kosa: Employment: Contractor at Pfizer (Clinical Assay Group) through Atrium Services. D.D. Wang: Employment: Pfizer Stock ownership: Pfizer.


Mobile edge computing (MEC) has been proposed as a promising solution, which enables the content processing at the edges of the network helping to significantly improve the quality of experience (QoE) of end users. In this article, we aim to utilize the MEC facilities integrated with time-varying renewable energy resources for charging/discharging scheduling known as green scheduling of on-move electric vehicles (EVs) in a geographical wide area comprising of multiple charging stations (CSs). In the proposed system, the charging/discharging demands and the contextual information of EVs are first transmitted to nearby edge servers. With instantaneous electricity load/pricing and the availability of renewable energy at nearby CSs collected by aggregators, a weighted social-welfare maximization problem is then solved at the edges using greedy-based algorithms to choose the best CS for the EV's service. From the system point of view, our results reveal that compared to cloud-based scheme, the proposed MEC-assisted EVs scheduling system significantly improves the complexity burden, boosts the satisfaction (QoE) of EVs' drivers by localizing the traffic at nearby CSs, and further helps to efficiently utilize the renewable energy across CSs. Furthermore, our greedy-based algorithm, which utilizes the internal updating heuristics, outperforms some baseline solutions in terms of social welfare and power grid ancillary services.


Flavocytochrome b(2) (yeast L-lactate dehydrogenase) carries one FMN and one protohaem IX on each of its four subunits. The prosthetic groups are bound to separate domains, the haem domain (residues 1-99) and the flavin domain (residues 100-485), which interact for electron transfer between lactate-reduced FMN and haem b(2); in vivo, the latter reduces cytochrome c. In the crystal structure, one haem domain out of two is mobile. Previously we have described a monoclonal antibody, raised against the tetramer, that only recognizes the native haem domain and prevents electron transfer between flavin and haem, while having no effect on flavin reduction by the substrate [Miles, Lederer and Lê (1998) Biochemistry 37, 3440-3448]. In order to understand the structural basis of the uncoupling between the domains, we proceeded to site-directed mutagenesis, so as to map the epitope on the surface of the haem domain. We analysed the effects of 14 mutations at 12 different positions, located mostly in the domain interface or at its edge; we also analysed the effect of replacing protohaem IX with its dimethyl ester. We used as criteria the antibody-mediated inhibition of cytochrome c reduction by flavocytochrome b(2), competitive ELISA tests and surface plasmon resonance. We have thus defined a minimal epitope surface on the haem domain; it encompasses positions 63, 64, 65, 67, 69 and 70 and one or both haem propionates. When the haem and flavin domains are docked for electron transfer, the 65, 67 and 70 side chains, as well as the haem propionates, are excluded from solvent. The present results thus indicate that, when bound, the antibody acts as a wedge between the domains and constitutes a physical barrier to electron transfer.


Zircon and apatite fission-track data from the LeMay Group accretionary complex and Fossil Bluff Group fore-arc basin sequence on Alexander Island (Antarctica) record a common regional Cretaceous and Cenozoic thermal and denudational history. With the exception of zircon data from samples closest to the trench, the apatite and zircon central ages are substantially less than known and, inferred stratigraphic ages. Thermal modelling of the data indicate cooling from maximum palaeotemperatures in the range 180–350°C at c. 100 Ma. A younger period of accelerated cooling occurred between 40 and 35 Ma with final cooling to surface temperatures taking place at reduced rates through the Tertiary. The start of cooling was close in time to the end of deposition within the fore-arc basin and is consistent with structural evidence for Cretaceous deformation in a strike-slip setting. The accelerated, Early Tertiary cooling episode was broadly coeval with, and may have been caused by ridge–trench collisions and cessation of subduction off-shore Alexander Island. Zircon and apatite age data, from magmatic rocks emplaced in the fore-arc region in Late Cretaceous and Tertiary times, are close to their age of crystallization. This indicates rapid cooling of both fission-track systems from temperatures >350°C to <c. 60°C at high crustal levels of emplacement. The formation of these magmatic rocks, together with the cooling history of the accretionary prism, are related to changes in subduction zone parameters during Cretaceous and Cenozoic times. Slowing of subduction rates and role-back of the slab prior to cessation of subduction by ridge–trench collision may have been responsible for migration of the magmatic focus into the fore-arc region, uplift of the prism and formation of the high mountain ranges, and the extensional graben that separates Alexander Island from the Antarctic Peninsula.


BACKGROUND
Circulating trans fatty acids (TFAs), which cannot be synthesized by humans, are linked to adverse health outcomes. Although TFAs are obtained from diet, little is known about subsequent influences (e.g., relating to incorporation, metabolism, or intercompetition with other fatty acids) that could alter circulating concentrations and possibly modulate or mediate impacts on health.

OBJECTIVE
The objective was to elucidate novel biologic pathways that may influence circulating TFAs by evaluating associations between common genetic variation and TFA biomarkers.

DESIGN
We performed meta-analyses using 7 cohorts of European-ancestry participants (n = 8013) having measured genome-wide variation in single-nucleotide polymorphisms (SNPs) and circulating TFA biomarkers (erythrocyte or plasma phospholipids), including trans-16:1n-7, total trans-18:1, trans/cis-18:2, cis/trans-18:2, and trans/trans-18:2. We further evaluated SNPs with genome-wide significant associations among African Americans (n = 1082), Chinese Americans (n = 669), and Hispanic Americans (n = 657) from 2 of these cohorts.

RESULTS
Among European-ancestry participants, 31 SNPs in or near the fatty acid desaturase (FADS) 1 and 2 cluster were associated with cis/trans-18:2; a top hit was rs174548 (β = 0.0035, P = 4.90 × 10(-15)), an SNP previously associated with circulating n-3 and n-6 polyunsaturated fatty acid concentrations. No significant association was identified for other TFAs. rs174548 in FADS1/2 was also associated with cis/trans-18:2 in Hispanic Americans (β = 0.0053, P = 1.05 × 10(-6)) and Chinese Americans (β = 0.0028, P = 0.002) but not African Americans (β = 0.0009, P = 0.34); however, in African Americans, fine mapping identified a top hit in FADS2 associated with cis/trans-18:2 (rs174579: β = 0.0118, P = 4.05 × 10(-5)). The association between rs174548 and cis/trans-18:2 remained significant after further adjustment for individual circulating n-3 and n-6 fatty acids, except arachidonic acid. After adjustment for arachidonic acid concentrations, the association between rs174548 and cis/trans-18:2 was nearly eliminated in European-ancestry participants (β-coefficient reduced by 86%), with similar reductions in Hispanic Americans and Chinese Americans.

CONCLUSIONS
Our findings provide novel evidence for genetic regulation of cis/trans-18:2 by the FADS1/2 cluster and suggest that this regulation may be influenced/mediated by concentrations of arachidonic acid, an n-6 polyunsaturated fat.