bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tendon elastic strain energy in the human ankle plantar-flexors and its role with increased running speed
Authors: Lai Adrian , Schache Anthony G. , Lin Yi-Chung , Pandy Marcus G. 
Published: June 2014

AbstractThe human ankle plantar-flexors, soleus (SOL) and gastrocnemius (GAS), utilize tendon elastic strain energy to reduce muscle fiber work and optimize contractile conditions during running. However, studies to date have considered only slow to moderate running speeds up to 5 m/s. Little is known about how the human ankle plantar-flexors utilize tendon elastic strain energy as running speed is advanced towards maximum sprinting. We used data obtained from gait experiments in conjunction with musculoskeletal modeling and optimization techniques to calculate muscle-tendon unit (MTU) work, tendon elastic strain energy and muscle fiber work for the ankle plantar-flexors as participants ran at five discrete steady-state speeds ranging from jogging (~2 m/s) to sprinting (≥8 m/s). As running speed progressed from jogging to sprinting, the contribution of tendon elastic strain energy to the positive work generated by the MTU increased from 53% to 74% for SOL and from 62% to 75% for GAS. This increase was facilitated by greater muscle activation and the relatively isometric behavior of the SOL and GAS muscle fibers. Both of these characteristics enhanced tendon stretch and recoil, which contributed to the bulk of the change in MTU length. Our results suggest that as steady-state running speed is advanced towards maximum sprinting, the human ankle plantar-flexors continue to prioritize the storage and recovery of tendon elastic strain energy over muscle fiber work.
Altered regulation of sleep and feeding contribute to starvation resistance in Drosophila
Authors: Masek Pavel , Reynolds Lauren A. , Bollinger Wesley L. , Moody Catriona , Mehta Aradhana , Murakami Kazuma , Yoshizawa Masato , Gibbs Allen G. , Keene Alex C. 
Published: June 2014

Abstract
Animals respond to changes in food availability by adjusting sleep and foraging strategies to optimize their fitness. Wild populations of the fruit fly, Drosophila melanogaster, display highly variable levels of starvation resistance that are dependent on geographic location, food availability, and evolutionary history. How behaviors that include sleep and feeding vary in Drosophila with increased starvation resistance is unclear. We have generated starvation resistant flies through experimental evolution to investigate the relationship between foraging behaviors and starvation resistance. Outbred populations of D. melanogaster were selected for starvation resistance over 60 generations. This selection process resulted in flies with a three-fold increase in total lipids that survive up to 18 days without food. We tested starvation-selected (S) flies for sleep and feeding behaviors to determine the effect that selection for starvation resistance has had on foraging behavior. Flies from three replicated starvation-selected populations displayed a dramatic reduction in feeding and prolonged sleep duration compared to fed control (F) populations, suggesting that modified sleep and feeding may contribute to starvation resistance. A prolonged larval developmental period contributes to the elevated energy stores present in starvation-selected flies. By preventing S larvae from feeding longer than F larvae, we were able to reduce energy stores in adult S flies to levels seen in adult F flies, thus allowing us to control for energy storage levels. However, the reduction of energy stores in S flies fails to generate normal sleep and feeding behavior seen in F flies with similar energy stores. These findings suggest that the behavioral changes observed in S flies are due to genetic regulation of behavior rather than elevated lipid levels. Testing S-F hybrid individuals for both feeding and sleep revealed a lack of correlation between food consumption and sleep duration, indicating further independence in genetic factors underlying the sleep and feeding changes observed in S flies. Taken together, these findings provide evidence that starvation selection results in prolonged sleep and reduced feeding through a mechanism that is independent of elevated energy stores. These findings suggest changes in both metabolic function and behavior contribute to the increase in starvation resistance seen in flies selected for starvation resistance.
Learning to cope with degraded sounds: Female zebra finches can improve their expertise at discriminating between male voices at long distance
Authors: Mouterde Solveig C. , Elie Julie E. , Theunissen Frédéric E. , Mathevon Nicolas 
Published: June 2014

AbstractReliable transmission of acoustic information about individual identity is of critical importance for pair bond maintenance in numerous monogamous songbirds. However, information transfer can be impaired by environmental constraints such as external noise or propagation-induced degradations. Birds have been shown to use several adaptive strategies to deal with difficult signal transmission contexts. Specifically, a number of studies have suggested that vocal plasticity at the emitter's level allows birds to counteract the deleterious effects of sound degradation. Although the communication process involves both the emitter and the receiver, perceptual plasticity at the receiver's level has received little attention. Here, we explored the reliability of individual recognition by female zebra finches (Taeniopygia guttata), testing whether perceptual training can improve discrimination of degraded individual vocal signatures. We found that female zebra finches are proficient in discriminating between calls of individual males at long distance, and even more so when they can train themselves with increasingly degraded signals over time. In this latter context, females succeed in discriminating between males as far as 250 m. This result emphasizes that adaptation to adverse communication conditions may not only involve the emitters' vocal plasticity, but also the receptors' decoding process through on-going learning.
Thermal effects on the performance, motor control, and muscle dynamics of ballistic feeding in the salamanderEurycea guttolineata
Authors: Anderson Christopher V. , Larghi Nicholas P. , Deban Stephen M. 
Published: June 2014

AbstractTemperature strongly affects muscle contractile rate properties and thus may influence whole-organism performance. Movements powered by elastic recoil, however, are known to be more thermally robust than muscle-powered movements. We examined the whole-organism performance, motor control and muscle contractile physiology underlying feeding in the salamander Eurycea guttolineata. We compared elastically powered tongue projection to the associated muscle-powered retraction to determine the thermal robustness of each of these functional levels. We found that tongue-projection distance in Eurycea was unaffected by temperature across the entire 4-26°C range, tongue-projection dynamics were significantly affected by temperature across only the 4-11°C interval, and tongue retraction was affected to a higher degree across the entire temperature range. The significant effect of temperature on projection dynamics across the 4-11°C interval corresponds to a significant decline in projector muscle burst intensity and peak contractile force of the projector muscle across the same interval. Across the remaining temperature range, however, projection dynamics were unaffected by temperature with contractile muscle physiology showing typical thermal effects and motor patterns showing increased activity durations and latencies. These results reveal that elastically powered tongue-projection performance in Eurycea is maintained to a higher degree than muscle-powered tongue retraction performance across a wide temperature range. These results further indicate that thermal robustness of the elastically powered movement is dependent on motor control and muscle physiology that results in comparable energy being stored in elastic tissues across a range of temperatures.
Hydrodynamics and energetics of jumping copepod nauplii and copepodids
Authors: Wadhwa Navish , Andersen Anders , Kiørboe Thomas 
Published: June 2014

Abstract
Within its life cycle, a copepod goes through drastic changes in size, shape and swimming mode. In particular, there is a stark difference between the early (nauplius) and later (copepodid) stages. Copepods inhabit an intermediate Reynolds number regime (between approximately 1 and 100) where both viscosity and inertia are potentially important, and the Reynolds number changes by an order of magnitude during growth. Thus we expect the life stage related changes experienced by a copepod to result in hydrodynamic and energetic differences, ultimately affecting the fitness. To quantify these differences, we measured the swimming kinematics and fluid flow around jumping Acartia tonsa at different stages of its life cycle, using particle image velocimetry and particle tracking velocimetry. We found that the flow structures around nauplii and copepodids are topologically different, with one and two vortex rings, respectively. Our measurements suggest that copepodids cover a larger distance compared to their body size in each jump and are also hydrodynamically quieter, as the flow disturbance they create attenuates faster with distance. Also, copepodids are energetically more efficient than nauplii, presumably due to the change in hydrodynamic regime accompanied with a well adapted body form and swimming stroke.
Does urban life change blood oxidative status in birds?
Authors: Costantini David , Greives Timothy J. , Hau Michaela , Partecke Jesko 
Published: June 2014

Abstract
Cities may expose wild animals to new types of selection pressures potentially leading to differentiation among urban and rural populations. One cellular mechanism likely important in determining the viability of vertebrate populations is resistance to oxidative stress, as tissue degradation resulting from oxidative stress may decrease reproductive performance and survival. We hypothesize that city-thriving Eurasian blackbirds (Turdus merula) would be more resistant to oxidative stress when exposed to stressful conditions than rural conspecifics. Hand-raised city and rural blackbirds kept under common garden conditions indeed differed in blood oxidative status when exposed to chronic stress: city birds had lower oxidative damage during stressful conditions compared to rural birds, but also tended to generally maintain lower levels of non-enzymatic and enzymatic antioxidants than rural birds. These findings show that individuals from urban and rural areas differ intrinsically in their blood oxidative status physiology, possibly as an adaptation to city life.
Opsin expression in Limulus eyes: A UV opsin is expressed in each eye type and co-expressed with a visible light-sensitive opsin in ventral larval eyes
Authors: Battelle Barbara-Anne , Kempler Karen E. , Harrison Alexandra , Dugger Donald R. , Payne Richard 
Published: June 2014

Abstract
The eyes of the horseshoe crab, Limulus polyphemus, are a model for studies of visual function and the visual systems of euarthropods. Much is known about the structure and function of Limulus photoreceptors; much less about their photopigments. Three visible light-sensitive Limulus opsins were characterized previously (LpOps1, 2 and 5). Here we characterize a UV opsin (LpUVOps1) that is expressed in all three types of Limulus eyes. It is expressed in most photoreceptors in median ocelli, the only Limulus eyes in which UV sensitivity was previously detected, and in the dendrite of eccentric cells in lateral compound eyes. Therefore, eccentric cells, previously thought to be non-photosensitive second order neurons, may actually be UV-sensitive photoreceptors. LpUVOps1 is also expressed in small photoreceptors in Limulus ventral larval eyes, and intracellular recordings from these photoreceptors confirm that LpUVOps1 is an active, UV-sensitive photopigment. These photoreceptors also express LpOps5 which we demonstrate is an active, long wavelength-sensitive photopigment. Thus small photoreceptors in ventral larval eyes, and probably those of the other larval eyes, have dual sensitivity to UV and visible light. Interestingly, the spectral tuning of small ventral photoreceptors may change day to night, since the level of LpOps5 in their rhabdoms is lower during the day than during the night, whereas LpUVOps1 levels show no diurnal change. These and previous findings show that opsin co-expression and the differential regulation of co-expressed opsins in rhabdoms is a common feature of Limulus photoreceptors.
Complexing Agents for Oxonium Anions of Mo and Re and Their Masking Effects on Extraction Using N-Donor Extractants
Authors: Sasaki Yuji , Suzuki Tomoya , Morita Keisuke , Tsubata Yasuhiro 
Published: June 2014

Abstract
Several complexing agents with a soft donor incomporated into their structures are examined for the masking effects of Mo and Re through solvent extraction. The available extractants are N,N,N′,N′,N′′,N′′-hexaoctylnitrilotriacetamide and N,N,N′,N′-tetraoctylmethyliminodiacetamide, whose extractants have high extractabilities. Mo and Re dissolved in HNO3 are clearly suppressed by masking agents with N-donor ligands, such as ethylenediamine, diethylenetriamine, and 1,3-diaminopropane, for extraction into the organic phase. Ligands that include a sulfur donor, e.g., thiourea, were also tested, but exhibited a weaker masking effect.
Case Report: Severe form of hemolytic-uremic syndrome with multiple organ failure in a child: a case report
Authors: Mijatovic Dino , Blagaic Ana , Zupan Zeljko 
Published: June 2014

Introduction: Hemolytic-uremic syndrome (HUS) is a leading cause of acute renal failure in infants and young children. It is traditionally defined as a triad of acute renal failure, hemolytic anemia and thrombocytopenia that occur within a week after prodromal hemorrhagic enterocolitis. Severe cases can also be presented by acute respiratory distress syndrome (ARDS), toxic megacolon with ileus, pancreatitis, central nervous system (CNS) disorders and multiple organ failure (MOF).Case presentation: A previously healthy 4-year old Caucasian girl developed acute renal failure, thrombocytopenia and hemolytic anemia following a short episode of abdominal pain and bloody diarrhea. By the end of the first week the diagnosis of the typical HUS was established. During the second week the disease progressed into MOF that included ileus, pancreatitis, hepatitis, coma and ARDS, accompanied by hemodynamic instability and extreme leukocytosis. Nonetheless, the girl made a complete recovery after one month of the disease. She was successfully treated in the intensive care unit and significant improvement was noticed after plasmapheresis and continuous veno-venous hemodialysis.Conclusions: Early start of plasmapheresis and meticulous supportive treatment in the intensive care unit, including renal placement therapy, may be the therapy of choice in severe cases of HUS presented by MOF. Monitoring of prognostic factors is important for early performance of appropriate diagnostic and therapeutical interventions.
Polynomially Computable Bounds for the Probability of the Union of Events
Authors: Boros Endre , Scozzari Andrea , Tardella Fabio , Veneziani Pierangela 
Published: June 2014

We consider the problem of finding upper and lower bounds for the probability of the union of events when the probabilities of the single events and the probabilities of the intersections of up to m events are given. It is known that the best possible bounds can be obtained by solving linear programming problems with a number of variables that is exponential in the number of events. Because of their size and structure, these large linear programs are known to be very hard to solve. In the literature simpler, polynomially sized aggregations are considered and numerous closed form or polynomially computable bounds are derived from those. We present here a new approach that introduces additional constraints to the dual linear programming problems in such a way that those become polynomially solvable. By using different sets of additional constraints, we introduce three new classes of polynomially computable upper and lower bounds. We show that they dominate almost all efficiently computable bounds known in the literature. Furthermore, by characterizing the vertices of two new classes of polyhedra, we can show that in two cases our bounds coincide with classical bounds, proving new extremal properties for those well-known bounds. Finally, we provide extensive numerical results comparing the average tightness of the various bounds on a large number of instances.
Experimental investigation of process parameters for WEDM of Ti-6Al-4V/TiN composites
Authors: Urtekin Levent 
Published: June 2014

AbstractTi-6Al-4V alloys are difficult-machine materials. These alloys are extensively used in medicine, chemical units, marine and food industries, and particularly in the aerospace industry. Machinability of Ti-6Al-4V in wire electric discharge machining (WEDM) has been empirically investigated. WEDM performance tests were conducted on TiN coated Ti-6Al-4V alloy with physical vapor deposition (PVD) method, which is harder and has higher wear resistance. The performance of machinability of Ti-6Al-4V and Ti-6Al-4V/TiN materials was analyzed. The most important performance characteristics of WEDM cutting are surface roughness, machining gap, and cutting speed. The tests were conducted under cutting parameters including varying pulse durations (300, 500, 700 μs), tension (50, 100 V) and wire feed rate (5, 8 m/min). Based on tension, pulse duration, and wire feed rate of heat-treated uncoated samples when compared to untreated samples and coated samples, feed rates were found to be at the highest value.
The dilemma of ischemia testing with different methods
Authors: Donataccio Maria Pia , Reverberi Claudio , Gaibazzi Nicola 
Published: June 2014

SummaryA 52-year-old man presented after one episode of effort angina, normal treadmill electrocardiogram (ECG), and clearly positive adenosine cardiac magnetic resonance (aCMR) for reversible perfusion defects in the left anterior descending (LAD) coronary artery territory. Contrast high-dose dipyridamole (0.84 mg/kg per 6 min) stress echocardiography (cSE) demonstrated normal myocardial perfusion (MP) and wall motion at rest, while perfusion defects were shown in the lateral and apical segments after dipyridamole. Wall motion at stress was completely normal and stress/rest Doppler diastolic velocity ratio on the LAD demonstrated reduced flow reserve. In this case, cSE was the provocative test detecting both the LAD and circumflex obstructive lesions, thanks to MP analysis, while wall motion assessment was negative, not different from treadmill ECG, and aCMR highlighted only the LAD disease.Learning pointsIn spite of the low sensitivity of wall motion assessment during stress-echocardiography to detect coronary artery disease (CAD) in patients with multivessel disease and balanced ischemia, the addition of cSE with myocardial perfusion assessment, is not only able to overcome this limitation of false negative rate on a per-patient basis, but may also depict multivessel myocardial perfusion defects more efficiently than aCMR, as in the reported case, thanks to high spatial resolution.Myocardial perfusion assessment during cSE, although not always technically feasible, has a very high spatial and temporal resolution which can easily demonstrate multivessel subendocardial perfusion defects during maximal vasodilation, which is often the only detectable marker of multivessel, balanced CAD.It is known that wall motion analysis during pharmacologic stress may result in falsely negative multivessel disease; in these cases perfusion imaging or Doppler measurement of coronary flow reserve may be helpful to detect multivessel obstructive CAD, which is a significant and dismal prognostic finding. aCMR is assumed as the perfect imaging modality for CAD detection, but in selected cases, such as the one presented, an advanced echocardiographic method in experienced hands can provide even more comprehensive results.
Genome-Wide Linkage-Disequilibrium Profiles from Single Individuals
Authors: Lynch Michael , Xu Sen , Maruki Takahiro , Jiang Xiaoqian , Pfaffelhuber Peter , Haubold Bernhard 
Published: June 2014

AbstractAlthough the analysis of linkage disequilibrium (LD) plays a central role in many areas of population genetics, the sampling variance of LD is known to be very large with high sensitivity to numbers of nucleotide sites and individuals sampled. Here we show that a genome-wide analysis of the distribution of heterozygous sites within a single diploid genome can yield highly informative patterns of LD as a function of physical distance. The proposed statistic, the correlation of zygosity, is closely related to the conventional population-level measure of LD, but is agnostic with respect to allele frequencies and hence likely less prone to outlier artifacts. Application of the method to several vertebrate species leads to the conclusion that &gt;80% of recombination events are typically resolved by gene-conversion-like processes unaccompanied by crossovers, with the average lengths of conversion patches being on the order of one to several kilobases in length. Thus, contrary to common assumptions, the recombination rate between sites does not scale linearly with distance, often even up to distances of 100 kb. In addition, the amount of LD between sites separated by &lt;200 bp is uniformly much greater than can be explained by the conventional neutral model, possibly because of the nonindependent origin of mutations within this spatial scale. These results raise questions about the application of conventional population-genetic interpretations to LD on short spatial scales and also about the use of spatial patterns of LD to infer demographic histories.
Stacked n-i-p-n-i-p Heterojunctions for Image Recognition
Authors: Vieira M. , Fantoni A. , Fernandes M. , Louro P. , Rodrigues I. 
Published: June 2014

AbstractThis work aims to clarify possible improvements and physical limits of the Color Laser Scanned Photodiode image sensor when used as high sensitive non-pixel image reader. A new design based on a stacked n-i-p-n-i-p heterojunction is proposed and compared with the old single n-i-p sensing structure. Results show that a B-W image is acquired with an improved resolution. The readout frequency is optimized showing that scans speeds up to 104lines per second can be achieved without degradation in the resolution. A physical model is presented and supported by an electrical and a numerical simulation of the output characteristics of the sensor.