bluuebunny/crossref_metadata_2025_split huggingface dataset:
Erythrocyte selenium concentration predicts intensive care unit and hospital mortality in patients with septic shock: a prospective observational study
Authors: Costa Nara Aline , Gut Ana Lúcia , Pimentel José Alexandre Coelho , Cozzolino Silvia Maria Franciscato , Azevedo Paula Schmidt , Fernandes Ana Angélica Henrique , Polegato Bertha Furlan , Tanni Suzana Erico , Gaiolla Rafael Dezen , Zornoff Leonardo Antonio Mamede , de Paiva Sergio Alberto Rupp , Minicucci Marcos Ferreira 
Published: May 2014

Abstract
Introduction
Selenoenzymes can modulate the extent of oxidative stress, which is recognized as a key feature of septic shock. The pathophysiologic role of erythrocyte selenium concentration in patients with septic shock remains unknown. Therefore, the objective of this study was to evaluate the association of erythrocyte selenium concentration with glutathione peroxidase (GPx1) activity, GPx1 polymorphisms and with ICU and hospital mortality in septic shock patients.

Methods
This prospective study included all patients older than 18 years with septic shock on admission or during their ICU stay, admitted to one of the three ICUs of our institution, from January to August 2012. At the time of the patients’ enrollment, demographic information was recorded. Blood samples were taken within the first 72 hours of the patients’ admission or within 72 hours of the septic shock diagnosis for determination of selenium status, protein carbonyl concentration, GPx1 activity and GPx1 Pro198Leu polymorphism (rs 1050450) genotyping.

Results
A total of 110 consecutive patients were evaluated. The mean age was 57.6 ± 15.9 years, 63.6% were male. Regarding selenium status, only erythrocyte selenium concentration was lower in patients who died in the ICU. The frequencies for GPx1 Pro198Leu polymorphism were 55%, 38% and 7% for Pro/Pro, Pro/Leu and Leu/Leu, respectively. In the logistic regression models, erythrocyte selenium concentration was associated with ICU and hospital mortality in patients with septic shock even after adjustment for protein carbonyl concentration and acute physiology and chronic health evaluation II score (APACHE II) or sequential organ failure assessment (SOFA).

Conclusions
Erythrocyte selenium concentration was a predictor of ICU and hospital mortality in patients with septic shock. However, this effect was not due to GPx1 activity or Pro198Leu polymorphism.
Trace determination of cadmium in water using anodic stripping voltammetry at a carbon paste electrode modified with coconut shell powder
Authors: Rajawat Deepak Singh , Kumar Nitin , Satsangee Soami Piara 
Published: May 2014

AbstractBackgroundIncreasing awareness on the environmental impact of heavy metals has increased a considerable interest in the determination of metals in natural water bodies. The present paper describes the development and electrochemical application of carbon paste electrode modified with fibrous part of coconut shell for the determination of cadmium in water samples.MethodsDetermination was carried out using anodic stripping voltammetry. It is a two-step process. First, the metal ions get accumulated at the electrode surface at open-circuit potential, followed by a potential scan for voltammetric determination of cadmium.ResultsDifferent parameters affecting the determination of Cd (II) were optimized and are as follows: HCl as stripping solvent, acetate buffer of pH 5 as accumulating solvent, and 15-min accumulation time. Triton X-100, cetyltrimethylammonium bromide, and sodium dodecyl sulfate were used as representative for neutral, cationic, and anionic surfactants, respectively, to see the effect of surface active macromolecules. Interference caused by other metal ions on the determination of cadmium was also studied.ConclusionsThe method shows the development of a sensor for the sensitive determination of cadmium with limit of detection at 105 μg L−1. This technique does not use mercury and, therefore, has a positive environmental benefit.
L-plastin is involved in NKG2D recruitment into lipid rafts and NKG2D-mediated NK cell migration
Authors: Serrano-Pertierra Esther , Cernuda-Morollón Eva , Brdička Tomáš , Hoøejši Václav , López-Larrea Carlos 
Published: May 2014

AbstractMembrane rafts are microdomains of the plasma membrane that have multiple biological functions. The involvement of these structures in the biology of T cells, namely in signal transduction by the TCR, has been widely studied. However, the role of membrane rafts in immunoreceptor signaling in NK cells is less well known. We studied the distribution of the activating NKG2D receptor in lipid rafts by isolating DRMs in a sucrose density gradient or by raft fractionation by β-OG-selective solubility in the NKL cell line. We found that the NKG2D-DAP10 complex and pVav are recruited into rafts upon receptor stimulation. Qualitative proteomic analysis of these fractions showed that the actin cytoskeleton is involved in this process. In particular, we found that the actin-bundling protein L-plastin plays an important role in the clustering of NKG2D into lipid rafts. Moreover, coengagement of the inhibitory receptor NKG2A partially disrupted NKG2D recruitment into rafts. Furthermore, we demonstrated that L-plastin participates in NKG2D-mediated inhibition of NK cell chemotaxis.
Variation in body condition during the post-moult foraging trip of southern elephant seals and its consequences on diving behaviour
Authors: Richard Gaëtan , Vacquié-Garcia Jade , Jouma'a Joffrey , Picard Baptiste , Génin Alexandre , Arnould John P. Y. , Bailleul Frédéric , Guinet Christophe 
Published: May 2014

Abstract
Mature female southern elephant seals come ashore only in October to breed and in January to moult, spending the rest of the year foraging at sea. Mature females may lose as much as 50% of their body mass, mostly in lipid stores, during the breeding season due to fasting and lactation. When departing to sea, post-breeding females are negatively buoyant and the relative change in body condition (i.e. density) during the foraging trip has previously been assessed by monitoring descent rate during drift dives. However, relatively few drift dives are performed resulting in low resolution of the temporal reconstruction of body condition change. In this study, six post-breeding females were instrumented with time-depth recorders and accelerometers to investigate whether changes in active swimming effort and speed could be used as an alternative method of monitoring density variations throughout the foraging trip. In addition, we assessed consequences of density change on the swimming effort of individuals while diving and effects on dive duration. Both descent swimming speed and ascent swimming effort were found to be strongly correlated to descent rate during drift dives, enabling the fine-scale monitoring of seal density change over the whole trip. Negatively buoyant seals minimized swimming effort during descents, gliding down at slower speeds, and reduced their ascent swimming effort to maintain a nearly constant swimming speed as their buoyancy increased. One percent of seal density variation over time was found to induce a 20% variation in swimming effort during dives with direct consequences on dive duration.
Living in warmer more acidic oceans retards physiological recovery from tidal emersion in the velvet swimming crabNecora puber(L.)
Authors: Rastrick Samuel P.S. , Calosi Piero , Calder-Potts Ruth , Foggo Andy , Nightingale Gregory , Widdicombe Stephen , Spicer John I. 
Published: May 2014

AbstractThe distribution patterns of many species in the intertidal zone are partly determined by their ability to survive and recover from tidal emersion. During emersion most crustaceans experience gill-collapse impairing gas-exchange. Such collapse generates a state of hypoxemia and a hypercapnia-induced respiratory acidosis, leading to hyperlactaemia and metabolic acidosis. However, how such physiological responses to emersion are modified by prior exposure to elevated CO2 and temperature combinations, indicative of future climate change scenarios, is not known. We therefore investigated key physiological responses of velvet swimming crabs, Necora puber, kept for 14 days at one of four pCO2/temperature treatments (400 μatm/10 °C, 1000 μatm/10 °C, 400 μatm/15 °C, 1000 μatm/15 °C), to experimental emersion and recovery. Pre-exposure to elevated pCO2 and temperature increased pre-emersion bicarbonate ion concentrations [HCO3-], increasing resistance to short periods of emersion (90 min). However, there was still a significant acidosis following 180 min emersion in all treatments. The recovery of extracellular acid base via the removal of extracellular pCO2 (PCO2) and lactate after emersion was significantly retarded by exposure to both elevated temperature and pCO2. If elevated environmental pCO2 and temperature lead to slower recovery after emersion, then some predominantly subtidal species that also inhabit the low to mid shore, such as N. puber, may have a reduced physiological capacity to retain their presence in the low intertidal zone, ultimately affecting their bathymetric range of distribution, as well as the structure, and diversity of intertidal assemblages.
Ant-fungal species combinations engineer physiological activity of fungus gardens
Authors: Seal Jon N. , Schiøtt Morten , Mueller Ulrich G. 
Published: May 2014

AbstractFungus-gardening insects are among the most complex organisms due to their extensive coevolutionary histories with obligate fungal symbionts and other microbes.Some fungus-gardening insect lineages share fungal symbionts with other members of their lineage and thus exhibit diffuse co-evolutionary relationships, while others exhibit little or no symbiont sharing, resulting in host-fungus fidelity. The mechanisms that maintain this symbiont fidelity are currently unknown. Prior work suggested that derived leaf-cutting ants in the genus Atta interact synergistically with leaf-cutter fungi ('Attamyces') by exhibiting higher fungal growth rates and enzymatic activities than when growing a fungus from the sister-clade to Attamyces (so-called 'Trachymyces') grown primarily by the non-leaf cutting Trachymyrmex ants that form, correspondingly, the sister-clade to leafcutting ants. To elucidate the enzymatic bases of host-fungus specialization in leafcutting ants, we conducted a reciprocal fungus-switch experiment between the ant Atta texana and the ant Trachymyrmex arizonensis and report measured enzymatic activities of switched, and sham-switched fungus gardens to digest starch, pectin, xylan, cellulose, and casein. Gardens exhibited higher amylase and pectinase activities when A. texana ants cultivated Attamyces compared to Trachymyces fungi, consistent with enzymatic specialization. In contrast, gardens showed comparable amylase and pectinase activities when T. arizonensis cultivated either fungal species. Although gardens of leaf-cutting ants are not known to be significant metabolizers of cellulose, T. arizonensis were able to maintain gardens with significant cellulase activity when growing either fungal species. In contrast to carbohydrate metabolism, protease activity was significantly higher in Attamyces than in Trachymyces, regardless of the ant host. Activity of some enzymes employed by this symbiosis therefore arises from complex interactions between ant-host and fungal-symbiont.
Gait-specific adaptation of locomotor activity in response to dietary restriction inCaenorhabditis elegans
Authors: Lüersen Kai , Faust Ulla , Gottschling Dieter-Christian , Döring Frank 
Published: May 2014

AbstractLocomotion is crucial for the survival of living organisms, as it allows foraging, flight and mating behaviour. In response to environmental cues, many organisms switch between alternative forms of locomotion, referred to as gaits. The nematode Caenorhabditis elegans exhibits two gaits: swimming in liquids and crawling on dense gels. The kinematics and patterns of muscle activity differ between the two gaits, with swimming being less efficient than crawling. We found that C. elegans when grown on dietary restriction (DR) plates and then tested immediately for swimming activity exhibit an accelerated frequency of body-bending swimming compared to ad libitum fed worms, resulting in an increased swimming speed. This response is independent of the presence or absence of food bacteria in the assay liquid. In contrast, the crawling speed of DR worms on assay agar plates is decreased and influenced by food availability. Since DR also attenuates the disturbed swimming activity of worms that are deficient in the presynaptic dopamine transporter DAT-1, our data link DR induced alterations of the swimming gait to synaptic processes. This strongly suggests a biochemical rather than a biomechanical response to DR provoked by changes in the worm's body structure. We conclude that the increase in locomotor activity in response to DR is specific to the swimming gait and might represent a survival strategy, allowing food-deprived nematodes to exit unfavourable environments.
Following the Sun: a mathematical analysis of the tracks of clock-shifted homing pigeons
Authors: Schiffner Ingo , Siegmund Bettina , Wiltschko Roswitha 
Published: May 2014

AbstractWe analyse the tracks of clock-shifted pigeons from six releases to determine how pigeons cope with the conflict between their sun compass and the other navigational cues. Time-lag embedding is used to calculate the short-term correlation dimension, a parameter that reflects the complexity of the navigational system and with it, the number of factors involved. In the beginning, while pigeons are still at the release site, the short-term correlation dimension is low; it increases as the birds leave the site, indicating the birds are now actively navigating. Clock-shifted pigeons show more scatter than the control birds, and their short-term correlation dimension becomes significantly smaller than that of the controls, remaining lower until the experimental birds reach their loft. This difference is small, but consistent and suggests a different rating and ranking of the navigational cues. Clock-shifted pigeons do not seem to simply ignore the information from their manipulated sun compass altogether, but appear to merely downgrade it in favour of other cues, like their magnetic compass. This is supported by observation that the final part of the tracks still shows a small deviation into the expected direction, indicating an effect of clock-shifting until the end of the homing flight.
Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks
Authors: Monternier Pierre-Axel , Marmillot Vincent , Rouanet Jean-Louis , Roussel Damien 
Published: May 2014

Abstract
Energy conservation is a key priority for organisms living in environments with seasonal shortages in resource supplies or spontaneously fasting during their annual cycle. The aim of the study was to determine whether the high fasting endurance of winter-acclimatized king penguin chicks (Aptenodytes patagonicus) would be associated with an adjustment of mitochondrial bioenergetics in pectoralis muscle, the largest skeletal muscle in penguins. The rates of mitochondrial oxygen consumption and ATP synthesis and mitochondrial efficiency (ATP/O ratio) were measured in winter-acclimatized chicks. We used pyruvate/malate and palmitoyl-L-carnitine/malate as respiratory substrates and results from naturally fasted chicks were compared to experimentally re-fed chicks. Bioenergetics analysis of pectoralis muscle revealed that mitochondria are on average 15% more energy efficient in naturally fasted than in experimentally fed chicks, indicating that fasted birds would consume fewer nutrients to sustain their energy demanding processes. We also found that moderate reductions in temperature from 38°C to 30°C further increase by 23% the energy coupling efficiency at the level of mitochondria, suggesting that king penguin chicks realize additional energy savings while becoming hypothermic during winter. It has been calculated that this adjustment of mitochondrial efficiency in skeletal muscle may contribute to nearly 25% of fasting-induced reduction in mass-specific metabolic rate measured in vivo. The present study shows that the regulation of mitochondrial efficiency triggers the development of an economical management of resources, which would maximize the conservation of endogenous fuel store by decreasing the cost of living in fasted winter-acclimatized king penguin chicks.
Hearing capacities and otolith size in two ophidiiform species (Ophidion rocheiandCarapus acus)
Authors: Kéver Loïc , Colleye Orphal , Herrel Anthony , Romans Pascal , Parmentier Eric 
Published: May 2014

AbstractNumerous studies have highlighted the diversity of fish inner ear morphology. However, the function of shape, size, and orientation of the different structures remains poorly understood. The saccule (otolithic endorgan) is considered as the principal hearing organ in fishes and it has been hypothesized that sagitta (saccular otolith) shape and size affect hearing capacities: large sagittae are thought to increase sensitivity. The sagittae of many ophidiids and carapids occupy a large volume inside the neurocranium. Hence they are of great interest to test the size hypothesis. The main aim of this study was to investigate hearing capacities and inner ear morphology in two ophidiiform species: Ophidion rochei and Carapus acus. We used a multidisciplinary approach that combines dissections, μCT-scan examinations, and auditory evoked potential technique. Carapus acus and O. rochei sagittae have similar maximal diameter, both species have larger otoliths than many non-ophidiiform species especially compared to the intra-neurocranium (INC) volume. Both species are sensitive to sounds up to 2100 Hz. Relative to the skull, O. rochei had smaller sagittae than the carapid but better hearing capacities from 300 to 900 Hz and similar sensitivities at 150 Hz and from 1200 to 2100 Hz. Results show that hearing capacities of a fish species cannot be predicted only based on sagitta size. Larger otoliths (in size relative to the skull) may have evolved mainly for performing vestibular functions in fishes, especially those ones that need to execute precise and complex movements.
Plasma osteocalcin levels as a predictor of cardiovascular disease in older men and women: a population-based cohort study
Authors: Holvik Kristin , van Schoor Natasja M , Eekhoff Elisabeth M W , den Heijer Martin , Deeg Dorly J H , Lips Paul , de Jongh Renate 
Published: May 2014

ObjectiveThe role of osteocalcin (OC) in cardiovascular disease (CVD) is unresolved. We aimed to study the association between plasma OC concentrations and the risk of non-fatal and fatal CVDs. We also aimed to investigate whether such an association, if present, would be mediated by established metabolic risk factors.DesignA population-based longitudinal cohort study.MethodsIn 1995/1996, OC was determined in blood samples drawn from 1319 subjects aged 65–88 years participating in the Longitudinal Aging Study Amsterdam in 1995/1996. The self-reported CVD events were collected every 3 years until 2005/2006, and CVD deaths until 1st January 2007. Cox proportional hazards regression was performed, considering potential confounders (smoking, physical activity, and BMI) and mediators (blood pressure, plasma triglycerides, total and HDL cholesterol, fructosamine, and aortic calcification).ResultsDuring the median 4.1 years follow-up, 709 subjects (53.8%) suffered a CVD event. There was no overall association between OC and CVD: hazard ratio (HR) was 0.97 (95% CI 0.90–1.04) per nmol/l higher plasma OC, adjusted for age and sex. There was a statistical interaction between plasma OC, age, and sex on CVD (P=0.014). In those subjects aged ≥75 years, age-adjusted HRs (95% CI) were 0.86 (0.75–0.99) in men and 1.16 (1.03–1.31) in women per nmol/l higher plasma OC. Adjustment for covariates only slightly attenuated the association in older-old men, but did not affect the association in older-old women.ConclusionA higher plasma OC concentration was associated with a reduced risk of CVD in older-old men and with an increased risk of CVD in older-old women. We found no evidence that this was mediated by arterial calcification or metabolic risk factors.
Budding Yeast for Budding Geneticists: A Primer on the Saccharomyces cerevisiae Model System
Authors: Duina Andrea A , Miller Mary E , Keeney Jill B 
Published: May 2014

Abstract
The budding yeast Saccharomyces cerevisiae is a powerful model organism for studying fundamental aspects of eukaryotic cell biology. This Primer article presents a brief historical perspective on the emergence of this organism as a premier experimental system over the course of the past century. An overview of the central features of the S. cerevisiae genome, including the nature of its genetic elements and general organization, is also provided. Some of the most common experimental tools and resources available to yeast geneticists are presented in a way designed to engage and challenge undergraduate and graduate students eager to learn more about the experimental amenability of budding yeast. Finally, a discussion of several major discoveries derived from yeast studies highlights the far-reaching impact that the yeast system has had and will continue to have on our understanding of a variety of cellular processes relevant to all eukaryotes, including humans.
Enhancing the Efficiency of a PEM Hydrogen Fuel Cell with Synthesized Metal-Nanoparticle/Graphene Composites Synergy
Authors: Isseroff Rebecca , Akhavan Benjamin , Pan Cheng , He Harry Shan , Sokolov Jonathan , Rafailovich Miriam 
Published: May 2014

ABSTRACTObstructing commercialization of Proton Exchange Membrane Fuel Cells (PEMFC) is the soaring cost of platinum and other catalysts used to increase membrane efficiency. The goal of this investigation is to find a relatively inexpensive catalyst for coating the membrane and enhancing the efficiency of the PEMFC. Graphene oxide was reduced using NaBH4 in the presence of metal salts, primarily KAuCl4 and K2PtCl4, to synthesize metal-nanoparticle/reduced graphene oxide (RGO). FTIR indicated the successful synthesis of RGO, while Transmission Electron Microscopy displayed the presence of nanoparticles on RGO sheets. Nafion® membranes were coated with metal-nanoparticle/RGO and tested in an experimental PEMFC alongside bare Nafion®, Gold (Au) nanoparticles, and RGO. The metal-nanoparticle/RGO composites enhanced the PEMFC compared to bare Nafion®. Au-RGO, the best catalyst composite, increased the efficiency up to 150% better than nanoparticles or RGO alone while using only 1% of the concentration of Au nanoparticles. Theoretical power output of the Au-RGO synergy could increase fuel cell efficiency up to 18 times more than the Au-nanoparticles themselves by altering concentrations of Au nanoparticles in Au-RGO. The Au nanoparticles changed the structure and catalytic ability of graphene in the Au-RGO, offering a promising future for PEM fuel cell technology.