bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct benefits and indirect costs of warm temperatures for high‐elevation populations of a solitary bee
Authors: Forrest Jessica R. K. , Chisholm Sarah P. M. 
Published: November 2016

AbstractWarm temperatures are required for insect flight. Consequently, warming could benefit many high‐latitude and high‐altitude insects by increasing opportunities for foraging or oviposition. However, warming can also alter species interactions, including interactions with natural enemies, making the net effect of rising temperatures on population growth rate difficult to predict. We investigated the temperature‐dependence of nesting activity and lifetime reproductive output over 3 yr in subalpine populations of a pollen‐specialist bee, Osmia iridis. Rates of nest provisioning increased with ambient temperatures and with availability of floral resources, as expected. However, warmer conditions did not increase lifetime reproductive output. Lifetime offspring production was best explained by rates of brood parasitism (by the wasp Sapyga), which increased with temperature. Direct observations of bee and parasite activity suggest that although activity of both species is favored by warmer temperatures, bees can be active at lower ambient temperatures, while wasps are active only at higher temperatures. Thus, direct benefits to the bees of warmer temperatures were nullified by indirect costs associated with increased parasite activity. To date, most studies of climate‐change effects on pollinators have focused on changing interactions between pollinators and their floral host‐plants (i.e., bottom‐up processes). Our results suggest that natural enemies (i.e., top‐down forces) can play a key role in pollinator population regulation and should not be overlooked in forecasts of pollinator responses to climate change.
Non‐random food‐web assembly at habitat edges increases connectivity and functional redundancy
Authors: Peralta Guadalupe , Frost Carol M. , Didham Raphael K. , Rand Tatyana A. , Tylianakis Jason M. 
Published: November 2016

AbstractHabitat fragmentation dramatically alters the spatial configuration of landscapes, with the creation of artificial edges affecting community structure and dynamics. Despite this, it is not known how the different food webs in adjacent habitats assemble at their boundaries. Here we demonstrate that the composition and structure of herbivore‐parasitoid food webs across edges between native and plantation forests are not randomly assembled from those of the adjacent communities. Rather, elevated proportions of abundant, interaction‐generalist parasitoid species at habitat edges allowed considerable interaction rewiring, which led to higher linkage density and less modular networks, with higher parasitoid functional redundancy. This was despite high overlap in host composition between edges and interiors. We also provide testable hypotheses for how food webs may assemble between habitats with lower species overlap. In an increasingly fragmented world, non‐random assembly of food webs at edges may increasingly affect community dynamics at the landscape level.
Rationale for and design of the TRUE‐AHF trial: the effects of ularitide on the short‐term clinical course and long‐term mortality of patients with acute heart failure
Authors: Packer Milton , Holcomb Richard , Abraham William T. , Anker Stefan , Dickstein Kenneth , Filippatos Gerasimos , Krum Henry , Maggioni Aldo P. , McMurray John J.V. , Mebazaa Alexandre , O'Connor Christopher , Peacock Frank , Ponikowski Piotr , Ruschitzka Frank , van Veldhuisen Dirk J. , Holzmeister Johannes ,   on behalf of the TRUE‐AHF Investigators and Committees
Published: November 2016

AbstractThe TRUE‐AHF is a randomized, double‐blind, parallel‐group, placebo‐controlled trial which is evaluating the effects of a 48‐h infusion of ularitide (15 ng/kg/min) on the short‐ and long‐term clinical course of patients with acute heart failure. Noteworthy features of the study include the early enrolment of patients following their initial clinical presentation (within 12 h), and entry blood pressure criteria and thresholds for the adjustment of drug infusion rates, which aim to minimize the risk of hypotension. The trial has two primary endpoints: (i) cardiovascular mortality during long‐term follow‐up; and (ii) the clinical course of patients during their index hospitalization. Cardiovascular mortality is evaluated in this event‐driven trial by following all randomized patients for the occurrence of death until the end of the entire study without truncation at an arbitrarily determined early time point. The clinical course during the index hospitalization is evaluated using the hierarchical clinical composite endpoint, which combines information regarding changes in symptoms and the occurrence of in‐hospital worsening heart failure events and death into a single ranked metric that captures interval clinical events and minimizes the likelihood of missing data and confounding due to intensification of background therapy. The design of the TRUE‐AHF trial capitalizes on lessons learned from earlier trials and aims to evaluate definitively the potential benefit of ularitide in patients with acute heart failure.Trial registration: NCT01661634
User‐independent assessment of conditioning pain modulation by cuff pressure algometry
Authors: Graven‐Nielsen T. , Izumi M. , Petersen K.K. , Arendt‐Nielsen L. 
Published: November 2016

AbstractBackgroundThe use of conditioning pain modulation (CPM) is hampered by poor reproducibility and lack of user‐independent paradigms. This study refined the CPM paradigm by applying user‐independent cuff algometry.MethodsIn 20 subjects, the CPM effect of conditioning with cuff stimulation on the arm was investigated by pain test stimuli on the contralateral leg before and in parallel with different cuff conditionings (10, 30, 60 kPa/60 s; 30, 60 kPa/10 s). As test stimulus, another cuff was inflated (1 kPa/s) until the subjects detected the pain tolerance threshold (PTT) during which the pain detection threshold (PDT) and the pressure at a pain intensity of 6 cm on a 10‐cm visual analogue scale (PVAS6) were extracted. For comparison, pressure pain thresholds (PPTs) as test stimuli were recorded by the user‐dependent handheld pressure algometry. Combinations of cuff locations for conditioning (pain intensity standardized) and contralateral test stimuli were additionally evaluated (leg–arm, leg–leg, arm–thigh). The test–retest reliability in two sessions 1 month apart was assessed in five CPM protocols.ResultsIn all protocols, the PDT, PVAS6 and PTT increased during conditioning compared with baseline (p < 0.05). The CPM effect (i.e. conditioning minus baseline) for PVAS6, PTT and PPT increased for increasing conditioning intensities (p < 0.05). The CPM effects were not significantly different for changes in conditioning durations or conditioning/test stimulus locations. In two sessions, the CPM effects for PVAS6 and PTT assessed after 60 s of conditioning on the leg/thigh showed the highest intra‐class correlations (0.47–0.73), where they were 0.04–0.6 for PPTs.ConclusionsThe user‐independent cuff algometry is reliable for CPM assessment and for supra‐pain threshold test stimuli better than the user‐dependent technology.SignificanceA user‐independent CPM technique where the conditioning is controlled by one cuff stimulation, and the test‐stimulus is provided by another cuff stimulation. This study shows that cuff algometry is reliable for CPM assessment.
Key Factors of Ternary Monolayers to Improve DNA Sensors Performance
Authors: Aufartova Jana , López Marta Sánchez‐Paniagua , Martín‐Fernández Begoña , López‐Ruiz Beatriz 
Published: November 2016

AbstractAn important factor affecting the performance of electrochemical genosensors is the immobilization strategy used to anchor the capture probes (CP) on the electrode surface. One of the most common immobilization systems involves the formation of self‐assembled monolayers of thiolated probes on gold surfaces, mainly due to its simplicity and effectiveness. Recent studies have shown that in two‐component thiolated DNA and mercaptohexanol (MCH) monolayers, there is incomplete backfilling that leads to defective surface blockage, producing unspecific background signal. In order to solve these problems, ternary monolayers have been proposed, in which besides MCH as primary diluent, a second diluent is added to enhance the hybridization efficiency and anti‐fouling properties of the surface. Herein, we report a thorough evaluation of different surface chemistries using two different sensors, one for the detection of a peanut allergen encoding sequence and the other one targeting a gluten‐encoding sequence. We assessed the relationship between CP length and the chemical characteristics of the diluents. Factors such as concentration, nature of the functional groups and chain length of the second diluent were evaluated. We found that length of diluents affects primarily the hybridization efficiency, while the type of functional groups, e.g. hydroxyl, carboxyl or a second thiol group, influences the degree of surface coverage. Results diverged between the two sensors evaluated.
Feasibility of magnetoencephalographic source imaging in patients with thalamic deep brain stimulation for epilepsy
Authors: Wennberg Richard , del Campo J. Martin , Shampur Nat , Rowland Nathan C. , Valiante Taufik , Lozano Andres M. , Garcia Dominguez Luis 
Published: November 2016

SummarySource localization of interictal spikes in patients with medically refractory epilepsy is the most common clinical application of magnetoencephalography (MEG). In recent decades, many patients with intractable epilepsy have been treated with various forms of neurostimulation, including thalamic deep brain stimulation (DBS). Patients with suboptimal seizure control after DBS might in some cases benefit from further investigations for resective epilepsy surgery, including MEG source imaging (MSI). We sought to determine the feasibility and accuracy of MSI in the setting of active thalamic DBS. Simultaneous EEG/MEG was obtained in a patient using an Elekta 306‐channel MEG system, with high‐frequency (100 Hz) DBS of the thalamic anterior nuclei cycling between on and off states. Magnetic artifacts associated with the DBS apparatus were successfully suppressed using the spatiotemporal signal space separation (tSSS) method. Electrical stimulation artifact was removed by standard digital low‐pass filtering. Dipole source modeling results for spike foci in frontal and posterior temporal regions were comparable between stimulation on and stimulation off states, and the source solutions corresponded well to the localization of spikes documented by intracranial EEG. MSI is thus feasible and source solutions can be accurate when performed in patients with active thalamic DBS for epilepsy.
Predictors, Moderators, and Mediators of Treatment Outcome Following Manualised Cognitive‐Behavioural Therapy for Eating Disorders: A Systematic Review
Authors: Linardon Jake , de la Piedad Garcia Xochitl , Brennan Leah 
Published: November 2016

AbstractThis systematic review synthesised the literature on predictors, moderators, and mediators of outcome following Fairburn's CBT for eating disorders. Sixty‐five articles were included. The relationship between individual variables and outcome was synthesised separately across diagnoses and treatment format. Early change was found to be a consistent mediator of better outcomes across all eating disorders. Moderators were mostly tested in binge eating disorder, and most moderators did not affect cognitive‐behavioural treatment outcome relative to other treatments. No consistent predictors emerged. Findings suggest that it is unclear how and for whom this treatment works. More research testing mediators and moderators is needed, and variables selected for analyses need to be empirically and theoretically driven. Future recommendations include the need for authors to (i) interpret the clinical and statistical significance of findings; (ii) use a consistent definition of outcome so that studies can be directly compared; and (iii) report null and statistically significant findings. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.
An effective discriminator for differentiating the root causes of packet transmission failures in indoor WSNs
Authors: Huang Tingpei , Chen Haiming , Cui Li , Li Shibao 
Published: November 2016

AbstractIt is well known that there are 2 kinds of causes, namely, channel errors and collisions, which lead to high probability of packet transmission failures in wireless networks. The ability of discriminating the above causes provides many opportunities for implementing high efficient networking protocols in wireless sensor networks. This paper presents EasiPLED, an effective discriminator that can accurately and timely predict these causes. EasiPLED has 3 salient features. First, it investigates frame‐level bit error rate (F‐BER) patterns and statistic characteristics of received signal strength indicator (RSSI) and link quality indicator through extensive indoor experiment studies. The F‐BER is measured at the receiver side by a coarse‐grained method without incurring any overhead. An adaptive RSSI estimator based on error‐based filter is proposed to mitigate effects of environment noises and hardware limitations on RSSI readings. Second, EasiPLED designs an off‐line classifier using machine learning method, which takes a combination of F‐BER and RSSI features as input and outputs the probability of dominant factor that causes transmission failures. Finally, it presents an on‐line discriminator to diagnose the cause of a failed transmission when it occurs at the receiver side, which achieves an accuracy by up to 95.4%. We evaluate the effectiveness of EasiPLED by applying it to link‐layer retransmission scheme and probabilistic polling protocol. Experimental results demonstrate that our method yields a reduction of single‐hop transmission delay by up to 47% and provides high packet delivery ratios as compared to the existing retransmission methods. The EasiPLED‐based probabilistic polling protocol achieves by up to 41.4% throughput gain over the existing method.
Effect of aluminum trihydrate as flame retardant on properties of a thermoplastic rubber nanocomposite
Authors: Khattab M. A. , Feteha Feteha Abdel Halim , Sadik W. A. , Abdel‐Bary E. M. 
Published: November 2016

SummaryIn this work, different concentrations, per hundred rubber (phr), of aluminum trihydrate (ATH) were added to thermoplastic rubber nanocomposite based on ethylene propylene diene monomer and linear low‐density polyethylene. The effect of the added compound on the flammability, rheological, mechanical properties, and electrical conductivity of the composite was studied. The results of the cone calorimeter showed a significantly reduction in the flammability of the composites occurred when the composite was treated with ATH. The peak heat release rate was reduced by about 66% when the composite was loaded with 180 phr of ATH. Moreover, the time to ignition prolonged up to 160%. The total smoke released decreased significantly as the concentrations of the ATH were increased. A reduction of about 69% in the total smoke released was observed when the composite was treated with 180 phr. The thermogravimetric analysis showed a reduction in the overall weight loss as the concentrations of ATH were increased. A reduction of about 50% of the original weight was observed when 180 phr of ATH was used. An appreciable decrease in tensile stress and strain with increasing ATH contents had been observed. The addition of ATH markedly reduced the conductivity of the thermoplastic rubber nanocomposite. Copyright © 2016 John Wiley & Sons, Ltd.
Field assisted sintering technology. Part I: Experiments, constitutive modeling and parameter identification
Authors: Rothe Steffen , Kalabukhov Sergei , Frage Nachum , Hartmann Stefan 
Published: November 2016

AbstractField‐assisted sintering technology (FAST), also well‐known under the term spark‐plasma sintering (SPS), is a grown process technology to produce parts made of a powder material. The process itself has the advantage of carrying out compaction, sintering and cooling with high temperature rates in one process step. This is done using an electrical current, which heats the graphite tools and, accordingly, the powder within the die itself. The theoretical description itself is very complicated caused by the fact of having electro‐thermomechanical coupling effects, large deformations, contact problems for each field, but the essential point are the amount of experiments required to determine the parameters of the model. In this article, the required experiments to obtain the electrical, thermal and mechanical properties of both materials are discussed, a constitutive model of compressible thermo‐viscoplasticity for copper powder is proposed, and aspects of material parameter identification are addressed. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational homogenization of liquid‐phase sintering based on a mixed variational format
Authors: Öhman Mikael , Larsson Fredrik , Runesson Kenneth 
Published: November 2016

AbstractIn this paper a mixed velocity‐pressure variational formulation is adopted for the subscale modeling of sintering stemming from micropores with surface tension. The macroscopic response is obtained from variationally consistent homogenization. As to the driving force for sintering, the model framework allows for a non‐spherical sintering stress, derived via the homogenization procedure, which contrasts traditional macroscopic modeling. The proposed method can seamlessly handle the transition from macroscopically compressible to incompressible response.For the Representative Volume Elements (RVEs) the weakly periodic, Neumann, and Dirichlet type boundary conditions are established, and it is shown that the Hill‐Mandel condition is satisfied. The numerical examples show the transient behavior of a 2D unit‐cell subjected to free sintering. Effective macroscale properties pertinent to different boundary conditions are compared for a 3D microstructure. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of the pallidothalamic fibre tracts in deep brain stimulation for dystonia: A diffusion MRI tractography study
Authors: Rozanski Verena Eveline , da Silva Nadia Moreira , Ahmadi Seyed‐Ahmad , Mehrkens Jan , da Silva Cunha Joao , Houde Jean‐Christophe , Vollmar Christian , Bötzel Kai , Descoteaux Maxime 
Published: November 2016

AbstractBackgroundDeep Brain Stimulation (DBS) of the Globus pallidus internus (GPi) is gold standard treatment in medically refractory dystonia. Recent evidence indicates that stimulation effects are also due to axonal modulation and affection of a fibre network. For the GPi, the pallidothalamic tracts are known to be the major motor efferent pathways. The aim of this study is to explore the anatomic vicinity of these tracts and DBS electrodes in dystonia applying diffusion tractography.MethodsDiffusion MRI was acquired in ten patients presenting for DBS for dystonia. We applied both a conventionally used probabilistic tractography algorithm (FSL) as well as a probabilistic streamline tracking approach, based on constrained spherical deconvolution and particle filtering with anatomic priors, to the datasets. DBS electrodes were coregistered to the diffusion datasets.ResultsWe were able to delineate the pallidothalamic tracts in all patients. Using the streamline approach, we were able to distinguish between the two sub‐components of the tracts, the ansa lenticularis and the fasciculus lenticularis. Clinically efficient DBS electrodes displayed a close anatomic vicinity pathway of the pallidothalamic tracts, and their course was consistent with previous tracer labelling studies. Although we present only anatomic data, we interpret these findings as evidence of the possible involvement of fibre tracts to the clinical effect in DBS. Electrophysiological intraoperative recordings would be needed to complement our findings. In the future, a clear and individual delineation of the pallidothalamic tracts could optimize the stereotactic process of optimal electrode localization. Hum Brain Mapp 38:1224–1232, 2017. © 2016 Wiley Periodicals, Inc.
Multiple‐region directed functional connectivity based on phase delays
Authors: Goelman Gadi , Dan Rotem 
Published: November 2016

AbstractNetwork analysis is increasingly advancing the field of neuroimaging. Neural networks are generally constructed from pairwise interactions with an assumption of linear relations between them. Here, a high‐order statistical framework to calculate directed functional connectivity among multiple regions, using wavelet analysis and spectral coherence has been presented. The mathematical expression for 4 regions was derived and used to characterize a quartet of regions as a linear, combined (nonlinear), or disconnected network. Phase delays between regions were used to obtain network's temporal hierarchy and directionality. The validity of the mathematical derivation along with the effects of coupling strength and noise on its outcomes were studied by computer simulations of the Kuramoto model. The simulations demonstrated correct directionality for a large range of coupling strength and low sensitivity to Gaussian noise compared with pairwise coherences. The analysis was applied to resting‐state fMRI data of 40 healthy young subjects to characterize the ventral visual system, motor system and default mode network (DMN). It was shown that the ventral visual system was predominantly composed of linear networks while the motor system and the DMN were composed of combined (nonlinear) networks. The ventral visual system exhibits its known temporal hierarchy, the motor system exhibits center ↔ out hierarchy and the DMN has dorsal ↔ ventral and anterior ↔ posterior organizations. The analysis can be applied in different disciplines such as seismology, or economy and in a variety of brain data including stimulus‐driven fMRI, electrophysiology, EEG, and MEG, thus open new horizons in brain research. Hum Brain Mapp 38:1374–1386, 2016. © 2016 Wiley Periodicals, Inc.
Serotonergic modulation of orbitofrontal activity and its relevance for decision making and impulsivity
Authors: Mavrogiorgou Paraskevi , Enzi Björn , Klimm Ann‐Kristin , Köhler Elke , Roser Patrik , Norra Christine , Juckel Georg 
Published: November 2016

AbstractBackgroundThe orbitofrontal cortex seems to play a crucial role in reward‐guided learning and decision making, especially for impulsive choice procedures including delayed reward discounting. The central serotonergic system is closely involved in the regulation of impulsivity, but how the serotonergic firing rate and release, best investigated by the loudness dependence of auditory evoked potentials (LDAEP), interact with orbitofrontal activity is still unknown.MethodsTwenty healthy volunteers (11 males, 9 females, 31.3 ± 10.6 years old) were studied in a 3T MRI scanner (Philips, Hamburg, Germany) during a delay discounting task, after their LDAEP was recorded using a 32 electrodes EEG machine (Brain Products, Munich, Germany).ResultsSignificant positive correlations were only found between the LDAEP and the medial orbitofrontal part of the superior frontal gyrus (SFG/MO) [Δ immediate reward – delayed reward] for the right (r = 0.519; P = 0.019) and left side (r = 0.478; P = 0.033). This relationship was stronger for females compared with males. Orbitofrontal activity was also related to the Barratt Impulsivity Scale.ConclusionsThis study revealed that low serotonergic activity as measured by a strong LDAEP was related to a high fMRI signal intensity of SFG/MO during immediate reward behavior which is related to impulsivity. Since this relationship was only found for the infralimbic medial and not for the middle or lateral part of the orbitofrontal cortex, an exclusive projection tract of the serotonergic system to this cortical region can be assumed to regulate impulsive reward‐orientated decision making. Hum Brain Mapp 38:1507–1517, 2017. © 2016 Wiley Periodicals, Inc.