bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of cadmium and calcium fluxes along the gut, malpighian tubules, and anal papillae of the dipteran Chironomus riparius
Authors: Leonard Erin M. , Belowitz Ryan , Agema Pieter , O'Donnell Michael J. 
Published: June 2018

Abstract

Chironomids are often one of the dominant organisms in significantly polluted freshwater. Many invertebrate studies have characterized whole-organism mechanisms of toxicity, for example, assessing cadmium (Cd) uptake via calcium (Ca) channels. However, with the use of the scanning ion-selective electrode technique and an innovative Cd-selective microelectrode, we analyze this relationship at the organ level using a realistic concentration of Cd and Ca in the hemolymph (blood). Generally, Cd fluxes follow the same directional pattern as Ca, although Ca fluxes are approximately 5 times higher than those of Cd. These results correlate well with previous studies indicating that chironomids have a higher affinity for Ca over Cd, which affords them tolerance to Cd toxicity. When saline Ca concentration was increased to 10 times physiological levels, Cd fluxes from the gut lumen into the cells of the midgut regions were reduced by 50 to 80%. Transport of Cd from hemolymph to tissue for the posterior midgut, Malpighian tubule, and proximal ceca was also reduced by approximately 50%. The present results indicate that Cd fluxes into or across the gut and Malpighian tubules are reduced by high Ca, suggesting that Cd may be transported in some cells by similar mechanisms. However, Cd was actively excreted at the anal papillae after a 48-h waterborne exposure to Cd, but this process was independent of Ca and instead may involve a P-glycoprotein-related pump to detoxify Cd. Environ Toxicol Chem 2018;37:2542–2549. © 2018 SETAC
Nanostructured Polyaniline: An Efficient Support Matrix for Platinum‐Ruthenium Anode Catalyst in Direct Methanol Fuel Cell
Authors: Das S. , Dutta K. , Kundu P. P. , Bhattacharya S. K. 
Published: June 2018

AbstractThe quest for an efficient catalyst support material for improved deposition of electrocatalyst nanaoparticles towards application in methanol oxidation reaction has been an active field of research for last few decades. The use of highly expensive, although efficient, platinum‐ruthenium (Pt‐Ru) catalyst demands its minimum loading requirement and maximum utilization. We, herein, propose the potentiality of polyaniline (PAni) nanostructures‐based catalyst support materials towards this utilization aspect. It was realized that the PAni nanowhiskers (NWs) support exhibited better dispersion and higher utilization of the deposited Pt‐Ru nanoparticles, as compared to the PAni nanofibers (NFs) and the commercial Vulcan carbon (C) supports. This led to the exhibition of higher electrocatalytic activity, suppressed catalyst poisoning and better stability by the Pt‐Ru/PAni NWs catalyst system. The charge transfer rates of the catalyst systems were found to be in the order Pt‐Ru/PAni NWs > Pt‐Ru/PAni NFs > Pt‐Ru/C. Moreover, the Pt‐Ru/PAni NWs catalyst system demonstrated the lowest solution resistance and the best performance in a direct methanol fuel cell (DMFC).
A New Direct Coupling Method for Photovoltaic Module‐PEM Electrolyzer Stack for Hydrogen Production
Authors: Yang Z. , Lin J. , Zhang H. , Lin B. , Lin G. 
Published: June 2018

AbstractA direct coupling hydrogen production system consisting of a photovoltaic (PV) cell and a proton exchange membrane (PEM) electrolyzer is established. The expression of the hydrogen production efficiency is derived and the general performance characteristics are revealed. The number of series‐parallel connected PV cell is optimized using the hydrogen production effficiency of the system as objection function. The maximum efficiency and the corresponding optimal values of the number of series‐parallel connected PV cell are obtained. In contrast to optimize the number of series‐parallel connected electrolyzer, a simple and efficent method is proposed. The effects of some important performance parameters, such as types of the solar cells, solar irradiance, and leakage resistance of the electrolyzer stacks on the hydrogen production efficiency of the direct coupling system are examined in detail. It is found that the proposed optimal coupling approach can efficiently improve the hydrogen production efficiency. Moreover, the maximum hydrogen production efficiency of the direct coupling system using the Si solar cell is higher than that of the one using the GdTe and AsGa solar cells. Finally, the hydrogen production efficiency increases as the leakage resistance increases.
Cathode Exhaust Gas Recirculation for Polymer Electrolyte Fuel Cell Stack
Authors: Becker F. , Pillath F. , Kallo J. 
Published: June 2018

AbstractTo ensure the required reliability and efficiency of a polymer electrolyte fuel cell (PEFC) system, an emergency situation in which the supply of ambient air has to be sealed off, is considered. In this case oxygen from a separate gas tank is fed to the fuel cell system. To prevent the loss of oxygen by the exhaust, the cathode gas can be fed back by cathode gas recirculation while oxygen is injected. Thereby the opportunity to feed back the humidity of the exhaust air for additional fuel cell humidification becomes available. The humidification of a PEFC is essential to ensure high protonic conductivity and reduce voltage losses. However, the water content of the inlet gas has to be regulated to prevent the electrodes from flooding. To control the humidity of the system the gas flow rate, the temperature of the fuel cell and the cathode gas can be adjusted. In addition, the enhanced water content in the system allows increasing the operating temperatures. This work focuses on an experimental study of a 12 kW PEFC‐system with cathode gas recirculation and a phenomenological model to optimize the fuel cell humidification depending on the operating parameters.
Application of a Fixed Monitoring Benchmark Approach to Evaluate Attainment of Time-Variable Water Quality Criteria: Copper Biotic Ligand Model as a Case Study
Authors: Ryan Adam , Santore Robert , Delos Charles 
Published: June 2018

Abstract

In 2007, the Biotic Ligand Model (BLM) became the basis for the US Environmental Protection Agency (USEPA) freshwater water quality criteria (WQC) for Cu. Applying the BLM typically results in time-variable WQC, which are not unique to the BLM; they result from any criteria approach that depends on water chemistry (e.g., ammonia criteria or hardness-based equations for metals). However, widespread use of the BLM has renewed interest in developing an approach that considers variability when setting permit limits or benchmarks. To aid in establishing these benchmarks, we developed a fixed monitoring benchmark (FMB) approach: a probability-based method that incorporates time variability in BLM-predicted instantaneous water quality criteria (IWQC) and instream Cu concentrations. The FMB approach provides benchmarks that can be used to simplify implementation of time-variable WQC. Although it appears reasonable to apply this approach to derive a site-specific regulatory limit, the FMB does not technically represent a limit above which aquatic effects are expected. Rather, it represents a fixed concentration intended to yield the same level of protection as time-variable IWQC, which rely upon toxic unit (TU) distribution; each TU is calculated for a single sample using the Cu concentration and IWQC for this sample. The distribution of TUs for a particular site is used to estimate the probability that instream Cu concentrations are below associated IWQC. Our results suggest that Cu variability and corresponding IWQC, and their degree of correlation, indicate the magnitude of the FMB relative to the IWQC distribution. The FMB approach determines a maximum Cu distribution such that the resulting WQC exceedance frequency is consistent with the level of protection that is intended for the applicable water quality standard (WQS). This approach makes use of time-variable BLM-based WQC in regulatory contexts wherein a single benchmark is consistent with past practices and established implementation methods. Integr Environ Assess Manag 2018;14:722–735. © 2018 SETAC

Key Points
The fixed monitoring benchmark (FMB) approach provides benchmarks that can be used to simplify implementation of time-variable water quality criteria. The magnitude of the FMB for a chemical at a given site will depend upon the relative variability of the chemical to its corresponding WQC and their degree of correlation.
Systematic review and meta‐analysis of studies on delivery preferences in Brazil
Authors: Reiter Marilia , Betrán Ana P. , Marques Fernando K. , Torloni Maria R. 
Published: June 2018

AbstractBackgroundCesarean delivery rates in Brazil are among the highest in the world. User preference is often mentioned as an important factor driving this.ObjectivesTo identify, appraise, and synthesize the results of studies into delivery preferences in Brazil.Search strategyMEDLINE, LILACS, and PsycINFO databases were searched, without language restrictions, using “delivery” and “preference” from inception to November 4, 2017.Selection criteriaCross‐sectional or cohort studies with quantitative data on delivery preferences of lay persons in Brazil.Data collection and analysisTwo reviewers performed study selection, quality assessment, and data extraction. A meta‐analysis of proportions with a preference for cesarean delivery was performed, including subgroups analyses.Main resultsThere were 28 studies with 31 071 participants included. The overall prevalence of preference for cesarean delivery was 27.2% (95% confidence interval [CI] 26.7%–27.7%; 28 studies, n=31 071). Cesarean delivery preference was higher among multiparas with previous cesarean deliveries (58.0%, 95% CI 56.6%–59.3%; nine studies, n=5542) than among multiparas without prior cesarean deliveries (17.3%, 95% CI 16.4%–18.2%; eight studies, n=7903), and among women with private health insurance (44.3%, 95% CI 43.0%–45.6%; nine studies, n=6048) than among those who depended on the public healthcare system (22.7%, 95% CI 22.2%–23.3%; 20 studies, n=24 314).ConclusionsOverall, most lay persons in Brazil did not prefer to deliver by cesarean.
INTERFACING INFANT MENTAL HEALTH KNOWLEDGE: PERSPECTIVES OF SOUTH AFRICAN SUPERVISORS SUPPORTING LAY MOTHER–INFANT HOME VISITORS
Authors: Bain Katherine , Baradon Tessa 
Published: June 2018

ABSTRACTThis article is part of a project investigating the interfacing of clinically and research‐generated knowledge in the field of infant mental health (IMH) with local cultural models of child care and development. The article explores the experiences and challenges reported by psychology‐trained supervisors in supervision with local, lay, trained home visitors. Supervisors and supervisees were drawn from two early intervention programs which apply relational IMH mental health models in socioeconomically deprived townships in South Africa. Literature that considers supervisors’ experiences of conducting supervision with lay counselors has been limited, and even more so in settings where there are marked cultural and contextual differences between supervisors and supervisees. These differences pose particular challenges regarding the finding of a shared theoretical understanding of the work as well as to the establishment of a secure working alliance. While it was found that psychoanalytic and attachment‐informed theories of infant development are applicable in these South African settings, differences in race, language, education, socioeconomic status, and culture between supervisors and supervisees challenge the supervisor–supervisee relationship and require psychological processing and creative solutions to ensure integrity in the application of the model.
Understanding the economic determinants of the severity of operational losses: A regularized generalized Pareto regression approach
Authors: Hambuckers Julien , Groll Andreas , Kneib Thomas 
Published: June 2018

SummaryWe investigate a novel database of 10,217 extreme operational losses from the Italian bank UniCredit. Our goal is to shed light on the dependence between the severity distribution of these losses and a set of macroeconomic, financial, and firm‐specific factors. To do so, we use generalized Pareto regression techniques, where both the scale and shape parameters are assumed to be functions of these explanatory variables. We perform the selection of the relevant covariates with a state‐of‐the‐art penalized‐likelihood estimation procedure relying onL1‐penalty terms. A simulation study indicates that this approach efficiently selects covariates of interest and tackles spurious regression issues encountered when dealing with integrated time series. Lastly, we illustrate the impact of different economic scenarios on the requested capital for operational risk. Our results have important implications in terms of risk management and regulatory policy.
Structural estimation of behavioral heterogeneity
Authors: Shi Zhentao , Zheng Huanhuan 
Published: June 2018

SummaryWe develop a behavioral asset pricing model in which agents trade in a market with information friction. Profit‐maximizing agents switch between trading strategies in response to dynamic market conditions. Owing to noisy private information about the fundamental value, the agents form different evaluations about heterogeneous strategies. We exploit a thin set—a small sub‐population—to point identify this nonlinear model, and estimate the structural parameters using extended method of moments. Based on the estimated parameters, the model produces return time series that emulate the moments of the real data. These results are robust across different sample periods and estimation methods.
Extension and refinement of the recognition motif for Toll-like receptor 5 activation by flagellin
Authors: Ivičak-Kocjan Karolina , Forstnerič Vida , Panter Gabriela , Jerala Roman , Benčina Mojca 
Published: June 2018

Abstract
TLRs sense conserved and essential molecular components of microbes that invade multicellular organisms. The wide range of TLR agonists, differing in size and shape, is recognized either through a single or a pair of binding sites on the ectodomains of TLRs. TLR5 recognizes bacterial flagellin through two distinct binding sites on the ectodomain, the first facilitating primary binding of flagellin and the second guiding receptor dimerization necessary for signaling. The regions of flagellin recognized by TLR5 encompass key functional regions within the D1 domain of flagellin, which is also required for the assembly of functional flagella. In addition to previously identified binding sites at the N-terminal and central segment of the TLR5 ectodomain, we extended the TLR5’-D1 interaction interface on TLR5 and showed a species-specific recognition relevance of this extended region. In addition, we showed that the loop and following β-hairpin region of flagellin, previously proposed to participate in the TLR5-flagellin dimerization interface, is not accountable for these species-specific differences. We further identified residues that contribute to the interaction between two TLR5 ectodomains in an active signaling complex. Our work demonstrates that flagellin is recognized by TLR5 through a more extensive interaction surface than previously characterized.
Site directed mutagenesis of TLR5 and flagellin identified functional residues beyond crystallized TLR5:flagellin complex and mapped TLR5 dimerization interface.
Predicting workplace relational dynamics using an affective model of relationships
Authors: Lopez‐Kidwell Virginie , Niven Karen , Labianca Giuseppe 
Published: June 2018

SummaryIntegrating insights from the organizational social networks and workplace affect literatures, the authors propose a dynamic model of relationships, focusing on the affect experienced within dyadic work relationships to predict their trajectory over time: either improving, declining, or static. The feelings each partner typically experiences within an ongoing relationship (trait relational affect) can be distinguished according to their hedonic tone and activation level, and the combination of both dyadic partners' trait relational affect is predictive of the relationship trajectory. Furthermore, the emotions each partner experiences during specific interactional episodes (state relational affect) can alter and disrupt this relationship trajectory, either temporarily or permanently, to the extent that they diverge from the trait relational affect that is typically experienced. A given relationship trajectory over time leads to the development of different types of informal work ties (strong, negative, or weak), which are associated with a wealth of organizational consequences including effort, motivation, performance, and innovation. The model addresses criticisms that organizational social network research neglects the role of affect and views networks as static entities. The model further provides affect researchers with a novel framework that considers affect as a relational rather than individual phenomenon.
LagLoc—a new surgical technique for locking plate systems
Authors: Triana Miguel , Gueorguiev Boyko , Sommer Christoph , Stoffel Karl , Agarwal Yash , Zderic Ivan , Helfen Tobias , Krieg James C , Krause Fabian , Knobe Matthias , Richards Robert Geoff , Lenz Mark 
Published: June 2018

ABSTRACTTreatment of oblique and spiral fractures remains challenging. The aim of this study was to introduce and investigate the new LagLoc technique for locked plating with generation of interfragmentary compression, combining the advantages of lag screw and locking‐head‐screw techniques. Oblique fracture was simulated in artificial diaphyseal bones, assigned to three groups for plating with a seven‐hole locking compression plate. Group I was plated with three locking screws in holes one, four, and seven. The central screw crossed the fracture line. In group II the central hole was occupied with a lag screw perpendicular to fracture line, whereas holes one and seven were occupied with locking screws. Group III was instrumented applying the LagLoc technique as follows. Hole four was predrilled perpendicularly to the plate, followed by overdrilling of the near cortex and insertion of a locking screw—crossing the fracture line—whose head was covered by a holding sleeve to prevent temporarily the locking in the plate hole and generate interfragmentary compression. Subsequently, the screw head was released and locked in the plate hole. Holes one and seven were occupied with locking screws. Interfragmentary compression in the fracture gap was measured using pressure sensors. All screws in the three groups were tightened with 4 Nm torque. Interfragmentary compression in group I (167 ± 25 N) was significantly lower in comparison to groups II (431 ± 21 N) and III (379 ± 59 N), p ≤ 0.005. The difference in compression between groups II and III remained not significant (p = 0.999). The new LagLoc technique offers an alternative tool to generate interfragmentary compression with the application of locking plates by combining the biomechanical advantages of lag screw and locking screw fixations. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2886–2891, 2018.
Survival and habitat selection of wood duck ducklings
Authors: Dyson Matthew E. , Schummer Michael L. , Barney Ted S. , Fedy Bradley C. , Henry Hugh A. L. , Petrie Scott A. 
Published: June 2018

ABSTRACTSurvival and habitat selection during brood‐rearing influences reproductive success and waterfowl population dynamics. For effective management, it is important to understand vital rates and habitat choice range wide. We investigated survival and habitat selection of female wood ducks (Aix sponsa) and ducklings at Long Point, Lake Erie, Ontario, Canada in 2014. We captured incubating females (n = 40) in nest boxes and used radio‐telemetry to monitor survival and habitat use to 30 days post‐hatch. Four female mortalities occurred during brood‐rearing and apparent brood and duckling survival were 0.42 (85% CI = 0.33, 0.51) and 0.16 (85% CI = 0.14, 0.18), respectively. Duckling survival was negatively associated with brood size and distance of first movement, whereas survival was positively associated with precipitation. Successful brood‐rearing wood ducks selected forested wetlands and habitats that provided dense vegetative cover. Conservation and restoration of forested wetlands and similar cover should increase the availability of brood‐rearing habitat. Placement of nest boxes close to selected land cover types and strategies associated with reducing inflated clutch sizes may improve offspring survival. Our spatially explicit habitat selection model informs spatial prioritization of habitat conservation and nest box placement strategies within the Great Lakes region. © 2018 The Wildlife Society.
A novel magnetoelectric biomagnetic susceptometer on iron level detection with mice tissue in vitro
Authors: Xi Hao , Lu Meng‐Chien , Luo Hao‐Su , Yang Q. X. , Zhang Q. M. 
Published: June 2018

AbstractIron plays a vital role in human body. Liver iron concentration (LIC) is directly correlated with total body iron and can be an important indicator to a variety of pathologies. Non‐invasive methods to quantitatively assess tissue iron with low‐cost and high sensitivity have drawn vast interests and investments. Among various methods, the magnetoelectric (ME) sensor‐based biomagnetic liver susceptometer (BLS) is of great promise because it operates at room temperature but with the same principle as that of the well‐developed SQUID (Superconducting Quantum Interference Device). Here, we report a magnetoelectric (ME) sensor‐based BLS system exploiting the recently developed PIN‐PMN‐PT piezoelectric single crystal. The newly developed ME BLS, which employs the horizontal scanning mechanism with a water bath interface to automatically eliminate the diamagnetic background of the tissues and irregular shape of torso, exhibits an overall sensitivity advancement (300×) to the sensor system previously reported. A linear correlation (R2 = 0.97) found between the system measurements and the biopsy data demonstrates the validity of the system. The ability to detect signals from only 3 cc of mouse liver tissue samples suggests a high spatial resolution which could be used for finer scanning and enable magnetic distribution image and profiling.