bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection of 430 Fatty Acid Methyl Esters from a Transesterified Butter Sample
Authors: Schröder Markus , Vetter Walter 
Published: March 2013

AbstractMilk fat is known to contain one of the highest number of fatty acids of all edible oils. Some of these fatty acids are known to be valuable (e.g. conjugated linoleic acids, furan fatty acid) and other as undesirable (e.g. saturated and some trans‐fatty acids) food ingredients. However, a comprehensive picture on the presence of many trace fatty acids has not been achieved. For this reason we have developed an analysis scheme based on the conversion of the fatty acids into methyl esters. The fatty acid methyl esters were then fractionated by urea complexation. Both the filtrate of the urea complexation (~4 % of the sample weight) and the original sample were fractionated by high‐speed counter‐current chromatography (HSCCC). The resulting fractions were analyzed by GC/MS analysis. With this method 430 fatty acids were detected in one single butter sample. More than 230 fatty acids had two or more double bonds. In addition to the widely known spectrum of fatty acids we also detected a range of cyclohexyl fatty acids (five homologues) and methyl‐branched fatty acids (including short chain and even‐numbered anteiso‐fatty acids), conjugated tetradecadienoic acids along with the novel ω‐oxo‐fatty acids (seven homologues). The reported relative retention time on the polar column may serve as a data base for the screening of other samples for this profusion of fatty acids.
Similarities and differences of clinical characteristics between Brugada syndrome and early repolarization syndrome
Authors: Watanabe Hiroshi , Minamino Tohru 
Published: March 2013

AbstractEarly repolarization (or J wave) is a common electrocardiographic finding that occurs in 1% to 10% of healthy persons. It has been generally considered benign for decades. However, there is increasing evidence showing that early repolarization is associated with the susceptibility to ventricular fibrillation and sudden cardiac death. Therefore, early repolarization syndrome, or J‐wave syndrome, has recently been proposed as a new disease entity. Brugada syndrome is characterized by ST‐segment elevation in the right precordial leads (V1 to V3) of a 12‐lead electrocardiogram, and is another form of idiopathic ventricular fibrillation associated with J‐point elevation. Brugada syndrome and early repolarization syndrome share genetic, clinical, and electrophysiological characteristics, such as causative genes, male dominance, pause‐dependent augmentation of J‐point elevation, and response to drugs. However, these two diseases also have certain differences. This review focuses on the similarities and differences between Brugada syndrome and early repolarization syndrome, both of which are associated with J‐point elevation and sudden cardiac death.
Hölder continuity of the Lyapunov exponent for analytic quasiperiodic Schrödinger cocycle with weak Liouville frequency
Authors: YOU JIANGONG , ZHANG SHIWEN 
Published: March 2013

AbstractFor analytic quasiperiodic Schrödinger cocycles, Goldshtein and Schlag [Hölder continuity of the integrated density of states for quasi-periodic Schrödinger equations and averages of shifts of subharmonic functions.Ann. of Math.(2)154(2001), 155–203] proved that the Lyapunov exponent is Hölder continuous provided that the base frequency$\omega $satisfies a strong Diophantine condition. In this paper, we give a refined large deviation theorem, which implies the Hölder continuity of the Lyapunov exponent for all Diophantine frequencies$\omega $, even for weak Liouville$\omega $, which improves the result of Goldshtein and Schlag.
Revealing the state space of turbulent pipe flow by symmetry reduction
Authors: Willis A. P. , Cvitanović P. , Avila M. 
Published: March 2013

AbstractSymmetry reduction by the method of slices is applied to pipe flow in order to obtain a quotient of the streamwise translation and azimuthal rotation symmetries of turbulent flow states. Within the symmetry-reduced state space, all travelling wave solutions reduce to equilibria, and all relative periodic orbits reduce to periodic orbits. Projections of these solutions and their unstable manifolds from their infinite-dimensional symmetry-reduced state space onto suitably chosen two- or three-dimensional subspaces reveal their interrelations and the role they play in organizing turbulence in wall-bounded shear flows. Visualizations of the flow within the slice and its linearization at equilibria enable us to trace out the unstable manifolds, determine close recurrences, identify connections between different travelling wave solutions and find, for the first time for pipe flows, relative periodic orbits that are embedded within the chaotic saddle, which capture turbulent dynamics at transitional Reynolds numbers.
EVOLUTION OF A COST-UTILITY MODEL OF DONEPEZIL FOR ALZHEIMER'S DISEASE
Authors: Peters Jaime L. , Anderson Rob , Hoyle Martin , Hyde Chris 
Published: March 2013

Objectives: The aim of this study was to describe the evolution of a cost-utility model used to inform the UK National Institute for Health and Clinical Excellence's (NICE) most recent decisions on the cost-utility of drug treatments for Alzheimer's disease (AD), and to explore the impact of structural assumptions on the cost-utility results.Methods: Changes informed by noted limitations of the decision model used in NICE's previous decisions (in 2006) were made cumulatively to the original decision model for donepezil compared with best supportive care (for patients with mild to moderate AD). Deterministic and probabilistic analyses were undertaken for each cumulative change of the model. The expected value of perfect information (EVPI) of parameter estimates and structural assumptions was also calculated.Results: Cumulative changes to the decision model highlighted how the results of the original model (incremental cost-effectiveness ratio of £81,000 per quality-adjusted life-year gained) related to those of the new model (where donepezil was estimated to be cost-saving), mainly due to uncertainty in the incremental cost of donepezil treatment over best supportive care (ranging from -£600 to £3,000 per patient). The partial EVPI analysis reflected this finding where further information on treatment discontinuations and cost parameter estimates were shown to be valuable in terms of reducing decision uncertainty.Conclusions: Assessing the evolution of the cost-utility model helped to identify and explore structural differences between cohort-based models and is likely to be useful for decision models in other disease areas. This approach makes the structural uncertainty explicit, forcing decision makers to address structural uncertainty in addition to parameter uncertainty.
IMPROVING ACCESS TO SKILLED ATTENDANCE AT DELIVERY: A POLICY BRIEF FOR UGANDA
Authors: Nabudere Harriet , Asiimwe Delius , Amandua Jacinto 
Published: March 2013

Objective:This study describes the process of production, findings for a policy brief on Increasing Access to Skilled Birth Attendance, and subsequent use of the report by policy makers and others from the health sector in Uganda.Methods:The methods used to prepare the policy brief use the SUPPORT Tools for evidence-informed health policy making. The problem that this evidence brief addresses was identified through an explicit priority setting process involving policy makers and other stakeholders, further clarification with key informant interviews of relevant policy makers, and review of relevant documents. A working group of national stakeholder representatives and external reviewers commented on and contributed to successive drafts of the report. Research describing the problem, policy options, and implementation considerations was identified by reviewing government documents, routinely collected data, electronic literature searches, contact with key informants, and reviewing the reference lists of relevant documents that were retrieved.Results:The proportion of pregnant women delivering from public and private non-profit facilities was low at 34 percent in 2008/09. The three policy options discussed in the report could be adopted independently or complementary to the other to increase access to skilled care. The Ministry of Health in deliberating to provide intrapartum care at first level health facilities from the second level of care, requested for research evidence to support these decisions. Maternal waiting shelters and working with the private-for-profit sector to facilitate deliveries in health facilities are promising complementary interventions that have been piloted in both the public and private health sector. A combination of strategies is needed to effectively implement the proposed options as discussed further in this article.Conclusions:The policy brief report was used as a background document for two stakeholder dialogue meetings involving members of parliament, policy makers, health managers, researchers, civil society, professional organizations, and the media.
Stable isotope analysis of ancient and modern gentoo penguin egg membrane and the krill surplus hypothesis in Antarctica
Authors: Emslie Steven D. , Polito Michael J. , Patterson William P. 
Published: March 2013

AbstractThe ‘krill surplus’ hypothesis in Antarctica posits that the historic depletion of krill-eating whales and seals in the 18–20th centuries provided a surplus of krill in the Southern Ocean that benefited penguins. A previous study which examined stable isotopes in ancient and modern tissues of Adélie penguin (Pygoscelis adeliae) provides support for this hypothesis. Specifically, a significant decrease in δ13C and δ15N values occurred in modern versus ancient tissues from an apparent dietary shift from fish to krill associated with the purported krill surplus. Here, we present new data on gentoo penguin (Pygoscelis papua) tissues from active and abandoned colonies at three locations in the Antarctic Peninsula. We found an overall, but weak, decrease in modern versus fossil δ15N and δ13C values of gentoo penguin egg membrane with considerable variation across three breeding sites. Dietary mixing models suggest that shifts between fish and krill in gentoo penguins were likely not as strong as those previously observed in Adélie penguins. This weaker signal probably results from the greater reliance on fish in their diets, past and present, though we cannot rule out declines in primary productivity or other ecosystem shifts which also could account for declines in δ13C and δ15N values.
Structure and ecology of freshwater benthic diatom communities from Byers Peninsula, Livingston Island, South Shetland Islands
Authors: Kopalová Kateřina , van de Vijver Bart 
Published: March 2013

AbstractDiatom and water chemistry samples were collected from 49 lakes, pools and rivers on Byers Peninsula (Livingston Island, South Shetland Islands) during the summer of 2009. A diverse diatom flora of 143 taxa was found. Fragilaria capucina s.l., Psammothidium papilio, Navicula dobrinatemniskovae and several Nitzschia taxa dominated the flora. The biogeographical analysis showed that more than 55% of all observed taxa presented a restricted Antarctic biogeographic distribution and only 30% had a cosmopolitan distribution, contrary to previously published data. Cluster analysis and Principal Components Analysis were used to classify the samples based on their chemical characteristics, revealing that nutrients and specific conductance were the main factors dividing the samples into four groups: young lakes, coastal lakes, larger lakes on the central plateau and smaller, temporary pools. Diatom communities corresponded well to this division and were strongly influenced by salinity and nutrients.
Geochemistry of streams from Byers Peninsula, Livingston Island
Authors: Lyons W. Berry , Welch K.A. , Welch S.A. , Camacho A. , Rochera C. , Michaud L. , deWit R. , Carey A.E. 
Published: March 2013

AbstractIn January and February 2009, a series of water samples were collected from streams on Byers Peninsula. These samples were analysed for major elements and δ18O to determine the role of lithology and landscape position on stream geochemistry, and to understand better the hydrology (i.e. residence time of water) of these systems. Precipitation chemistry is enriched in Na+, as are the streams located close to the coast. Streams originating from inland locations have much higher percentages of Ca2+. In contrast, Mg2+ varied little, though streams that are in greater contact with volcanic-derived soils have slightly higher concentrations. Anion percentages varied greatly between streams with SO42- ranging from 5% to 45% of the anion composition. Dissolved Si concentrations as high as 141 μM were observed. All these data suggest that active chemical weathering is occurring in this region. A time series over 13 days at one stream showed little variation in major element geochemistry. The δ18O of precipitation samples collected over this same period varied by ∼10‰ while the majority of stream samples varied less than ∼1.5‰. These data indicate that the stream waters represent mixtures of precipitation events, melting snow and water from the subsurface that had gained solutes through chemical weathering.
Interannual active layer variability at the Limnopolar Lake CALM site on Byers Peninsula, Livingston Island, Antarctica
Authors: de Pablo M.A. , Blanco J.J. , Molina A. , Ramos M. , Quesada A. , Vieira G. 
Published: March 2013

AbstractIn order to monitor the evolution of the active layer in the South Shetland Islands, in February 2009 we established a new Circumpolar Active Layer Monitoring (CALM) site in the Limnopolar Lake basin on Byers Peninsula, Livingston Island. We monitored air, surface and ground (two boreholes of 135 and 80 cm deep) temperatures and Active Layer Thickness (ALT) was measured by mechanical probing in early February 2009, 2010 and 2011. The mean ALT was 44 cm with a range of about 92 cm, but where permafrost existed it was deeper than 1.0 m, as could be inferred from the borehole temperatures. ALT at this site was very dependent on air temperature and snow cover thickness, the ALT spatial distribution presenting the same pattern as soil penetration resistance, and higher values ALT coinciding with sites where patterned ground, ponds, and a near surface ground water saturation were observed. Additionally, ground temperature data provided an excellent tool for understanding the relationship between the ALT measured during the thaw season and the thermal evolution of the ground throughout the year.
Heterogeneous vertical structure of the bacterioplankton community in a non-stratified Antarctic lake
Authors: Villaescusa Juan A. , Casamayor Emilio O. , Rochera Carlos , Quesada Antonio , Michaud Luigi , Camacho Antonio 
Published: March 2013

AbstractBacterial community composition during summer was analysed in surface and bottom waters of the oligotrophic shallow (4.5 m) Lake Limnopolar (Livingston Island, South Shetland Islands, Antarctica), using 16S rRNA gene clone libraries and sequencing. Up to 61% of the 16S rDNA sequences found were closely related to sequences retrieved from lakes, glaciers or polar systems. The distribution of these sequences was not homogeneous, with vertical differences found in both bacterial taxa composition and isolation source of the closest match from GenBank. In the surface sample 86% of the sequences were related to bacteria found in soils, seawater or gut microbiota, probably explained by waterborne transport from the catchment, by wind through sea sprays, or local bird activity. Conversely, in the deep samples, 95% of the sequences were closer to bacteria typically described for lakes, glaciers or polar systems. The presence of benthic mosses covering the bottom of the lake favours a more stable deep layer leading to the existence of this biological heterogeneity through the water column, although the lake does not show physical-chemical stratification in summer. This study illustrates a strong influence of external factors on the microbial ecology of this model Antarctic lake.
Distribution and reproductive capacity of Deschampsia antarctica and Colobanthus quitensis on Byers Peninsula, Livingston Island, South Shetland Islands, Antarctica
Authors: Vera María Luisa , Fernández-Teruel Teresa , Quesada Antonio 
Published: March 2013

AbstractThe Maritime Antarctic is one of the regions where regional climate change is most intense and the reproductive performance of plants may be enhanced. Reporting the distribution of Deschampsia antarctica and Colobanthus quitensis on Byers Peninsula (Livingston Island, South Shetland Islands), our results confirm that D. antarctica is more widespread than C. quitensis. Flower and seed development of both species varied between sites. Deschampsia antarctica produced more viable seeds than C. quitensis, although fully developed seeds were not found at all locations. Seed production in C. quitensis was low in comparison with other Antarctic locations. The largest cushions of Colobanthus observed in 2002 were 15 cm in diameter, suggesting that the populations may have established at least 50 years ago. Deschampsia antarctica tussocks were very often 20 cm in diameter, although turf areas up to 1.5 m across were also observed, probably due to coalesced aggregates of individuals. This study shows that, although seed production is low, the presence of seedlings and young individuals suggests an expansion process.
A review of scientific research trends within ASPA No. 126 Byers Peninsula, South Shetland Islands, Antarctica
Authors: Benayas J. , Pertierra L. , Tejedo P. , Lara F. , Bermudez O. , Hughes K.A. , Quesada A. 
Published: March 2013

AbstractByers Peninsula, Livingston Island, was one of the first sites in Antarctica designated for environmental conservation and scientific protection. Research on Byers Peninsula has been predominantly international, with 88 indexed publications (93% of them published during last 20 years) from 209 authors affiliated to 110 institutions from 22 nations, all of which are signatories to the Antarctic Treaty. Palaeontological research represented 20% of the published articles. The variety of freshwater bodies within the area has made Byers Peninsula a reference site for limnological studies (24% of papers). The site also contains numerous outcrops and periglacial features relevant to geology, stratigraphy and geomorphology (29%). Terrestrial biodiversity is extraordinarily high for lichens, bryophytes and invertebrates (15% of articles). Only 5% of the publications concern research on human activities, including both archaeology and impact monitoring. Glaciology, meteorology and climatology studies represent only 7% of papers. This work highlights the international and multidisciplinary nature of science conducted on Byers Peninsula in order to promote international cooperation and to provide information relevant for environmental management and conservation.
Environmental management of a scientific field camp in Maritime Antarctica: reconciling research impacts with conservation goals in remote ice-free areas
Authors: Pertierra Luis R. , Hughes Kevin A. , Benayas Javier , Justel Ana , Quesada Antonio 
Published: March 2013

AbstractCurrently, a substantial proportion of Antarctic research is carried out through deployment of field camps, but little detailed information on the running of these facilities is often available. The remoteness of camps and the fragility of local Antarctic terrestrial ecosystems make the running of sustainable, low impact field science and logistics in ice-free areas a challenge for environmental managers. In this study we examined the environmental management at the Spanish camp within Antarctic Specially Protected Area (ASPA) No. 126 Byers Peninsula, Livingston Island, South Shetland Islands. Firstly, the input of materials and generation of pollution associated with the camp during a ten year period of operation was quantified. Examination of greenhouse gas emissions shows a mean of 14 t CO2equivalent per researcher associated with transportation of people to the site, plus 44 t CO2equivalent per researcher, associated with transportation of cargo to the field site. Secondly, the cumulative trampling footprint across Byers Peninsula and associated local impacts were recorded. Results showed the pattern of human movement within the ASPA and how activities concentrated around the field camp site. At the same time every effort was taken to ensure scientific outputs from research activities within the ASPA were maximized. Practical recommendations on operational logistics are discussed to minimize environmental impacts and optimize scientific benefits.
Mapping snow cover and snow depth across the Lake Limnopolar watershed on Byers Peninsula, Livingston Island, Maritime Antarctica
Authors: Fassnacht S.R. , López-Moreno J.I. , Toro M. , Hultstrand D.M. 
Published: March 2013

AbstractFew parts of Antarctica are not permanently covered in ice. The retreat of the ice sheet from Byers Peninsula on western Livingston Island, Maritime Antarctica, has provided a new area of seasonal snow cover. Snow surveys were conducted in late November 2008 at the time of peak accumulation across the 1 km2Lake Limnopolar watershed. Topographic variables were derived from a digital elevation model to determine the variables controlling the presence or absence of snow and the distribution of snow depth. Classification with binary regression trees showed that wind related variables dominated the presence and depth of snow. The product of the sine of aspect and the sine of slope was the first variable in both regression trees. Density profiles were also measured and illustrated a relatively homogeneous snowpack over space at peak snow accumulation.
Serological and virological surveys of the influenza A viruses in Antarctic and sub-Antarctic penguins
Authors: Abad F. Xavier , Busquets Núria , Sanchez Azucena , Ryan Peter G. , Majó Natàlia , Gonzalez-Solís Jacob 
Published: March 2013

AbstractTo evaluate the avian influenza virus (AIV) circulation in Antarctic and sub-Antarctic penguins we carried out a serosurvey on six species from Livingston, Marion and Gough islands. Seropositivity against AIV was performed on serum samples using a competitive enzyme-linked immunosorbent assay and haemagglutination and neuraminidase inhibition assays. Some oropharyngeal and cloacal swabs were also assayed to detect influenza virus genomes by real time reverse transcription-polymerase chain reaction. Overall, 12.1% (n= 140) penguins were seropositive to AIV. By species, we detected 5% (n= 19) and 11% (n= 18) seroprevalence in sub-Antarctic rockhopper penguins (Eudyptesspp.) from Gough and Marion islands, respectively, 42% (n= 33) seroprevalence in macaroni penguins (Eudyptes chysolophusBrandt), but no positives in the three other species, gentoo (Pygoscelis papuaForster;n= 25) and chinstrap penguins (P. antarcticaForster;n= 16), from Livingston Island and king penguins (Aptenodytes patagonicusMiller;n= 27) from Marion Island. While seropositivity reflected previous exposure to the AIV, the influenza genome was not detected. Our results indicate that AIV strains have circulated in penguin species in the sub-Antarctic region, but further studies are necessary to determine the precise role that such penguin species play in AIV epidemiology and if this circulation is species (or genus) specific.