bluuebunny/crossref_metadata_2025_split huggingface dataset:
Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct‐Current Cardioversion: An Echocardiographic Study
Authors: Osmanagic Armin , Möller Sören , Osmanagic Azra , Sheta Hussam M. , Vinther Kristina H. , Egstrup Kenneth 
Published: May 2016

AbstractBACKGROUNDAttempts to achieve rhythm control using direct‐current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atrial sphericity index (LASI) acquired by 2‐dimensional transthoracic echocardiography (TTE) could be used as a predictor of AF recurrence after successful DCC.HypothesisA baselline LASI assessed by 2D TTE can predict AF recurrence after successful DCC in patients with persistent AF.MethodsA total of 124 consecutive patients with persistent AF lasting <120 days underwent successful DCC. Other than β‐blockers, no other antiarrhythmic treatment was administered. Prior to DCC, all patients underwent thorough TTE, and LASI was calculated as the fraction of the left atrial width/length of the largest possible left atrial volume in a 4‐chamber view. The primary outcome was a TTE‐estimated baseline LASI as a predictor of AF recurrence after successful DCC for persistent AF.ResultsAnatomically, a more spherical shape of the left atrium (LASI >0.9) proved to be a strong and independent predictor of AF recurrence, with an odds ratio between 4.1 (95% confidence interval: 1.6‐11.9, P = 0.005) and 7.6 (95% confidence interval: 3.3‐19.7; P = 7.2 × 10−6). The receiver operating characteristic curve indicated good power for distinguishing between recurring and nonrecurring AF, and we chose a cutoff of 0.9 because high specificity was a priority for clinical reasons.ConclusionsIn conclusion, baseline LASI >0.9 was associated with significantly greater AF recurrence throughout the 12‐month follow‐up period.
Long‐Time Behavior, Invariant Measures, and Regularizing Effects for Stochastic Scalar Conservation Laws
Authors: Gess Benjamin , Souganidis Panagiotis E. 
Published: May 2016

AbstractWe study the long‐time behavior and regularity of the pathwise entropy solutions to stochastic scalar conservation laws with random‐in‐time spatially homogeneous fluxes and periodic initial data. We prove that the solutions converge to their spatial average, which is the unique invariant measure of the associated random dynamical system, and provide a rate of convergence, the latter being new even in the deterministic case for dimensions higher than 2. The main tool is a new regularization result in the spirit of averaging lemmata for scalar conservation laws, which, in particular, implies a regularization by noise‐type result for pathwise quasi‐solutions.© 2016 Wiley Periodicals, Inc.
Study of Copper Ferrite as a Novel Photocathode for Water Reduction: Improving Its Photoactivity by Electrochemical Pretreatment
Authors: Díez‐García María Isabel , Lana‐Villarreal Teresa , Gómez Roberto 
Published: May 2016

AbstractStudies on water‐splitting p‐type oxide electrodes based on nontoxic earth‐abundant elements are scarce. Herein, the behavior of electrodes composed of CuFe2O4 nanoparticles 30 nm in size is presented. The as‐prepared CuFe2O4 nanoporous electrodes exhibit small anodic photocurrents in 0.1 m NaOH. However, an electrochemical pretreatment consisting in the application of sufficiently positive potentials leads to p‐type behavior with a photocurrent onset as high as 1.1 V versus the reversible hydrogen electrode, which is among the most positive values reported for an oxide absorbing visible light (band gap of 2.1 eV). This photocurrent is partly due to H2 evolution, but there are also signs of photoreduction of the material. Although the photocurrents are modest, these results point to the possibility of using CuFe2O4 as a photocathode material in water‐splitting devices. Furthermore, the strategy employed for the enhancement in the CuFe2O4 photoactivity could be extended to other photocathode materials.
Electrochemical Reduction of CO2 at Metal Electrodes in a Distillable Ionic Liquid
Authors: Chen Lu , Guo Si‐Xuan , Li Fengwang , Bentley Cameron , Horne Mike , Bond Alan M. , Zhang Jie 
Published: May 2016

AbstractThe electroreduction of CO2 in the distillable ionic liquid dimethylammonium dimethylcarbamate (dimcarb) has been investigated with 17 metal electrodes. Analysis of the electrolysis products reveals that aluminum, bismuth, lead, copper, nickel, palladium, platinum, iron, molybdenum, titanium and zirconium electroreduce the available protons in dimcarb to hydrogen rather than reducing CO2. Conversely, indium, tin, zinc, silver and gold are able to catalyze the reduction of CO2 to predominantly carbon monoxide (CO) and to a lesser extent, formate ([HCOO]−). In all cases, the applied potential was found to have a minimal influence on the distribution of the reduction products. Overall, indium was found to be the best electrocatalyst for CO2 reduction in dimcarb, with faradaic efficiencies of approximately 45 % and 40 % for the generation of CO and [HCOO]−, respectively, at a potential of −1.34 V versus Cc+/0 (Cc+=cobaltocenium) employing a dimethylamine to CO2 ratio of less than 1.8:1.
An improved neutral landscape model for recreating real landscapes and generating landscape series for spatial ecological simulations
Authors: van Strien Maarten J. , Slager Cornelis T. J. , de Vries Bauke , Grêt‐Regamey Adrienne 
Published: May 2016

AbstractMany studies have assessed the effect of landscape patterns on spatial ecological processes by simulating these processes in computer‐generated landscapes with varying composition and configuration. To generate such landscapes, various neutral landscape models have been developed. However, the limited set of landscape‐level pattern variables included in these models is often inadequate to generate landscapes that reflect real landscapes. In order to achieve more flexibility and variability in the generated landscapes patterns, a more complete set of class‐ and patch‐level pattern variables should be implemented in these models. These enhancements have been implemented in Landscape Generator (LG), which is a software that uses optimization algorithms to generate landscapes that match user‐defined target values. Developed for participatory spatial planning at small scale, we enhanced the usability of LG and demonstrated how it can be used for larger scale ecological studies. First, we used LG to recreate landscape patterns from a real landscape (i.e., a mountainous region in Switzerland). Second, we generated landscape series with incrementally changing pattern variables, which could be used in ecological simulation studies. We found that LG was able to recreate landscape patterns that approximate those of real landscapes. Furthermore, we successfully generated landscape series that would not have been possible with traditional neutral landscape models. LG is a promising novel approach for generating neutral landscapes and enables testing of new hypotheses regarding the influence of landscape patterns on ecological processes. LG is freely available online.
Do the antipredator strategies of shared prey mediate intraguild predation and mesopredator suppression?
Authors: Clare John D. J. , Linden Daniel W. , Anderson Eric M. , MacFarland David M. 
Published: May 2016

AbstractUnderstanding the conditions that facilitate top predator effects upon mesopredators and prey is critical for predicting where these effects will be significant. Intraguild predation (IGP) and the ecology of fear are hypotheses used to describe the effects of top predators upon mesopredators and prey species, but make different assumptions about organismal space use. TheIGPhypothesis predicts that mesopredator resource acquisition and risk are positively correlated, creating a fitness deficit. But if shared prey also avoid a top predator, then mesopredators may not have to choose between risk and reward. Prey life history may be a critical predictor of how shared prey respond to predation and may mediate mesopredator suppression. We used hierarchical models of species distribution and abundance to test expectations ofIGPusing two separate triangular relationships between a large carnivore, smaller intraguild carnivore, and shared mammalian prey with different life histories. FollowingIGP, we expected that a larger carnivore would suppress a smaller carnivore if the shared prey species did not spatially avoid the large carnivore at broad scales. If prey were fearful over broad scales, we expected less evidence of mesopredator suppression. We tested these theoretical hypotheses using remote camera detections across a large spatial extent. Lagomorphs did not appear to avoid coyotes, and fox detection probability was lower as coyote abundance increased. In contrast, white‐tailed deer appeared to avoid areas of increased wolf use, and coyote detection probability was not reduced at sites where wolves occurred. These findings suggest that mesopredator suppression by larger carnivores may depend upon the behavior of shared prey, specifically the spatial scale at which they perceive risk. We further discuss how extrinsic environmental factors may contribute to mesopredator suppression.
Mid‐latitude shrub steppe plant communities: climate change consequences for soil water resources
Authors: Palmquist Kyle A. , Schlaepfer Daniel R. , Bradford John B. , Lauenroth William K. 
Published: May 2016

AbstractIn the coming century, climate change is projected to impact precipitation and temperature regimes worldwide, with especially large effects in drylands. We use big sagebrush ecosystems as a model dryland ecosystem to explore the impacts of altered climate on ecohydrology and the implications of those changes for big sagebrush plant communities using output from 10 Global Circulation Models (GCMs) for two representative concentration pathways (RCPs). We ask: (1) What is the magnitude of variability in future temperature and precipitation regimes among GCMs and RCPs for big sagebrush ecosystems, and (2) How will altered climate and uncertainty in climate forecasts influence key aspects of big sagebrush water balance? We explored these questions across 1980–2010, 2030–2060, and 2070–2100 to determine how changes in water balance might develop through the 21st century. We assessed ecohydrological variables at 898 sagebrush sites across the western US using a process‐based soil water model, SOILWAT, to model all components of daily water balance using site‐specific vegetation parameters and site‐specific soil properties for multiple soil layers. Our modeling approach allowed for changes in vegetation based on climate. Temperature increased across all GCMs and RCPs, whereas changes in precipitation were more variable across GCMs. Winter and spring precipitation was predicted to increase in the future (7% by 2030–2060, 12% by 2070–2100), resulting in slight increases in soil water potential (SWP) in winter. Despite wetter winter soil conditions, SWP decreased in late spring and summer due to increased evapotranspiration (6% by 2030–2060, 10% by 2070–2100) and groundwater recharge (26% and 30% increase by 2030–2060 and 2070–2100). Thus, despite increased precipitation in the cold season, soils may dry out earlier in the year, resulting in potentially longer, drier summer conditions. If winter precipitation cannot offset drier summer conditions in the future, we expect big sagebrush regeneration and survival will be negatively impacted, potentially resulting in shifts in the relative abundance of big sagebrush plant functional groups. Our results also highlight the importance of assessing multiple GCMs to understand the range of climate change outcomes on ecohydrology, which was contingent on the GCM chosen.
Seedling survival responses to conspecific density, soil nutrients, and irradiance vary with age in a tropical forest
Authors: Record Sydne , Kobe Richard K. , Vriesendorp Corine F. , Finley Andrew O. 
Published: May 2016

AbstractUnderstanding processes that promote species coexistence is integral to diversity maintenance. In hyperdiverse tropical forests, local conspecific density (LCD) and light are influential to woody seedling recruitment and soil nutrients are often limiting, yet the simultaneous effects of these factors on seedling survival across time remain unknown. We fit species‐ and age‐specific models to census and resource data of seedlings of 68 woody species from a Costa Rican wet tropical forest. In decreasing order of prevalence, seedling survivorship was related to LCD, soil base cations, irradiance, nitrogen, and phosphorus. Species–specific responses to factors did not covary, providing evidence that species life history strategies have not converged to one continuum of high‐surviving stress tolerant to low‐surviving stress intolerant species. Survival responses to all factors varied over the average seedling's lifetime, indicating seedling requirements change with age and conclusions drawn about processes important to species coexistence depend on temporal resolution.
Effects of functional diversity loss on ecosystem functions are influenced by compensation
Authors: Pan Qingmin , Tian Dashuan , Naeem Shahid , Auerswald Karl , Elser James J. , Bai Yongfei , Huang Jianhui , Wang Qibing , Wang Hong , Wu Jianguo , Han Xingguo 
Published: May 2016

AbstractUnderstanding the impacts of biodiversity loss on ecosystem functioning and services has been a central issue in ecology. Experiments in synthetic communities suggest that biodiversity loss may erode a set of ecosystem functions, but studies in natural communities indicate that the effects of biodiversity loss are usually weak and that multiple functions can be sustained by relatively few species. Yet, the mechanisms by which natural ecosystems are able to maintain multiple functions in the face of diversity loss remain poorly understood. With a long‐term and large‐scale removal experiment in the Inner Mongolian grassland, here we showed that losses of plant functional groups (PFGs) can reduce multiple ecosystem functions, including biomass production, soilNO3‐N use, net ecosystem carbon exchange, gross ecosystem productivity, and ecosystem respiration, but the magnitudes of these effects depended largely on whichPFGs were removed. Removing the two dominantPFGs (perennial rhizomatous grasses and perennial bunchgrasses) simultaneously resulted in dramatic declines in all examined functions, but such declines were circumvented when either dominantPFGwas present. We identify the major mechanism for this as a compensation effect by which each dominantPFGcan mitigate the losses of others. This study provides evidence that compensation ensuing fromPFGlosses can mitigate their negative consequence, and thus natural communities may be more resilient to biodiversity loss than currently thought if the remainingPFGs have strong compensation capabilities. On the other hand, ecosystems without well‐developed compensatory functional diversity may be much more vulnerable to biodiversity loss.
Habituation deficit of auditory N100m in patients with fibromyalgia
Authors: Choi W. , Lim M. , Kim J.S. , Chung C.K. 
Published: May 2016

AbstractBackgroundHabituation refers to the brain's inhibitory mechanism against sensory overload and its brain correlate has been investigated in the form of a well‐defined event‐related potential, N100 (N1). Fibromyalgia is an extensively described chronic pain syndrome with concurrent manifestations of reduced tolerance and enhanced sensation of painful and non‐painful stimulation, suggesting an association with central amplification of all sensory domains. Among diverse sensory modalities, we utilized repetitive auditory stimulation to explore the anomalous sensory information processing in fibromyalgia as evidenced by N1 habituation.MethodsAuditory N1 was assessed in 19 fibromyalgia patients and age‐, education‐ and gender‐matched 21 healthy control subjects under the duration‐deviant passive oddball paradigm and magnetoencephalography recording. The brain signal of the first standard stimulus (following each deviant) and last standard stimulus (preceding each deviant) were analysed to identify N1 responses. N1 amplitude difference and adjusted amplitude ratio were computed as habituation indices.ResultsFibromyalgia patients showed lower N1 amplitude difference (left hemisphere: p = 0.004; right hemisphere: p = 0.034) and adjusted N1 amplitude ratio (left hemisphere: p = 0.001; right hemisphere: p = 0.052) than healthy control subjects, indicating deficient auditory habituation. Further, augmented N1 amplitude pattern (p = 0.029) during the stimulus repetition was observed in fibromyalgia patients.ConclusionsFibromyalgia patients failed to demonstrate auditory N1 habituation to repetitively presenting stimuli, which indicates their compromised early auditory information processing. Our findings provide neurophysiological evidence of inhibitory failure and cortical augmentation in fibromyalgia.What's already known about this topic?

Fibromyalgia has been associated with altered filtering of irrelevant somatosensory input. However, whether this abnormality can extend to the auditory sensory system remains controversial.

N!00, an event‐related potential, has been widely utilized to assess the brain's habituation capacity against sensory overload.

What does this study add?

Fibromyalgia patients showed defect in N100 habituation to repetitive auditory stimuli, indicating compromised early auditory functioning.

This study identified deficient inhibitory control over irrelevant auditory stimuli in fibromyalgia.
Treatment Emergent Suicidal Ideation in depressed older adults
Authors: Cristancho Pilar , O'Connor Brendan , Lenze Eric J , Blumberger Daniel M. , Reynolds Charles F , Dixon David , Mulsant Benoit H. 
Published: May 2016

BackgroundTreatment‐Emergent Suicidal Ideation (TESI) in older adults is poorly understood. We characterized TESI in older depressed adults during treatment with venlafaxine and explored whether TESI is related to antidepressant exposure versus dimensions of the psychiatric illness. We examined the relationship among medication exposure, onset of TESI, and clinical characteristics.MethodsWe analyzed data on 233 clinical trial participants with major depression and no baseline suicidal ideation who were treated for up to 12 weeks with venlafaxine XR (target dose: 150–300 mg/day). Suicidal ideation was assessed weekly with the Scale for Suicide Ideation. A Kaplan‐Meier curve displayed the time course of TESI. Differences in baseline demographic and clinical variables between the TESI and Non‐TESI groups were assessed with analyses of covariance or logistic regression. A final multivariate logistic regression model indicated baseline predictors of TESI. Depression treatment outcomes in subjects developing TESI versus those who did not were examined with a mixed effects model.ResultsTESI occurred in 10% of participants, typically with onset within 4 weeks of the start of treatment. Anxiety, and depression severity at baseline were predictors of TESI. Most TESI was mild and transient, with 6/233 participants having TESI considered clinically meaningful. TESI was not associated with venlafaxine blood levels or side effects.ConclusionsIn older depressed adults, TESI is relatively uncommon and it is likely related to the underlying illness rather than to a medication adverse effect. This suggests that TESI requires continuing rather than discontinuing antidepressant treatment. Copyright © 2016 John Wiley & Sons, Ltd.
Monitoring microstructural variations of fresh skeletal muscle tissues by Mueller matrix imaging
Authors: He Honghui , He Chao , Chang Jintao , Lv Donghong , Wu Jian , Duan Chaijie , Zhou Qian , Zeng Nan , He Yonghong , Ma Hui 
Published: May 2016

Recently many attempts have been made for extracting the structural information of myofibrils as indicators for diseases of skeletal muscle. In this paper we adopt wide‐field illumination and take the backscattering Mueller matrix images of bovine skeletal muscle tissues during the 24‐hour experimental time after the animal's death. The 2D images of Mueller matrix elements and their frequency distribution histograms (FDHs) reveal rich qualitative information on the changes in the microstructures of the skeletal muscle. The temporal variations of the sample are quantitatively analyzed using two Mueller matrix transformation (MMT) parameters. The characteristic features of the temporal plots are attributed to the rigor mortis and proteolysis processes. For a deeper insight on the relationship between the features of the MMT parameters and the microstructures during the rigor mortis and proteolysis processes, Monte Carlo (MC) simulations are carried out based on sphere‐cylinder birefringence model (SCBM). The good agreement between the experimental and MC simulated results show that the FDHs and MMT parameters can describe more clearly the characteristic microstructural features of skeletal muscle tissues. The techniques are useful for the characterization of physiological status of tissues, or quantitative assessment of meat qualities in food industry.
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Direct influence of culture dimensionality on human mesenchymal stem cell differentiation at various matrix stiffnesses using a fibrous self‐assembling peptide hydrogel
Authors: Hogrebe Nathaniel J. , Gooch Keith J. 
Published: May 2016

AbstractMuch is unknown about the effects of culture dimensionality on cell behavior due to the lack of biomimetic substrates that are suitable for directly comparing cells grown on two‐dimensional (2D) and encapsulated within three‐dimensional (3D) matrices of the same stiffness and biochemistry. To overcome this limitation, we used a self‐assembling peptide hydrogel system that has tunable stiffness and cell‐binding site density as well as a fibrous microarchitecture resembling the structure of collagen. We investigated the effect of culture dimensionality on human mesenchymal stem cell differentiation at different values of matrix stiffness (G′ = 0.25, 1.25, 5, and 10 kPa) and a constant RGD (Arg–Gly–Asp) binding site concentration. In the presence of the same soluble induction factors, culture on top of stiff gels facilitated the most efficient osteogenesis, while encapsulation within the same stiff gels resulted in a switch to predominantly terminal chondrogenesis. Adipogenesis dominated at soft conditions, and 3D culture induced better adipogenic differentiation than 2D culture at a given stiffness. Interestingly, initial matrix‐induced cell morphology was predictive of these end phenotypes. Furthermore, optimal culture conditions corresponded to each cell type's natural niche within the body, highlighting the importance of incorporating native matrix dimensionality and stiffness into tissue engineering strategies. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2356–2368, 2016.