bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonstationary stochastic response of structural systems equipped with nonlinear viscous dampers under seismic excitation
Authors: Tubaldi Enrico , Kougioumtzoglou Ioannis A. 
Published: July 2014

SUMMARYNonlinear viscous dampers are supplemental devices widely used for enhancing the performance of structural systems exposed to seismic hazard. A rigorous evaluation of the effect of these damping devices on the seismic performance of a structural system should be based on a probabilistic approach and take into account the evolutionary characteristics of the earthquake input and of the corresponding system response.In this paper, an approximate analytical technique is proposed for studying the nonstationary stochastic response characteristics of hysteretic single degree of freedom systems equipped with viscous dampers subjected to a fully nonstationary random process representing the seismic input. In this regard, a stochastic averaging/linearization technique is utilized to cast the original nonlinear stochastic differential equation of motion into a simple first‐order nonlinear ordinary differential equation for the nonstationary system response variance. In comparison with standard linearization schemes, the herein proposed technique has the significant advantage that it allows to handle realistic seismic excitations with time‐varying frequency content. Further, it allows deriving a formula for determining the nonlinear system response evolutionary power spectrum. By this way, ‘moving resonance’ effects, related to both the evolutionary seismic excitation and the nonlinear system behavior, can be observed and quantified.Several applications involving various system and input properties are included. Furthermore, various response parameters of interest for the seismic performance assessment are considered as well. Comparisons with pertinent Monte Carlo simulations demonstrate the reliability of the proposed technique. Copyright © 2014 John Wiley & Sons, Ltd.
Anatomically heterogeneous populations of CB1 cannabinoid receptor‐expressing interneurons in the CA3 region of the hippocampus show homogeneous input–output characteristics
Authors: Szabó Gergely G. , Papp Orsolya I. , Máté Zoltán , Szabó Gábor , Hájos Norbert 
Published: July 2014

ABSTRACTA subpopulation of GABAergic cells in cortical structures expresses CB1 cannabinoid receptors (CB1) on their axon terminals. To understand the function of these interneurons in information processing, it is necessary to uncover how they are embedded into neuronal circuits. Therefore, the proportion of GABAergic terminals expressing CB1 and the morphological and electrophysiological properties of CB1‐immunoreactive interneurons should be revealed. We investigated the ratio and the origin of CB1‐expressing inhibitory boutons in the CA3 region of the hippocampus. Using immunocytochemical techniques, we estimated that ∼40% of GABAergic axon terminals in different layers of CA3 also expressed CB1. To identify the inhibitory cell types expressing CB1 in this region, we recorded and intracellularly labeled interneurons in hippocampal slices. CB1‐expressing interneurons showed distinct axonal arborization, and were classified as basket cells, mossy‐fiber‐associated cells, dendritic‐layer‐innervating cells or perforant‐path‐associated cells. In each morphological category, a substantial variability in axonal projection was observed. In contrast to the diverse morphology, the active and passive membrane properties were found to be rather similar. Using paired recordings, we found that pyramidal cells displayed large and fast unitary postsynaptic currents in response to activating basket and mossy‐fiber‐associated cells, while they showed slower and smaller synaptic events in pairs originating from interneurons that innervate the dendritic layer, which may be due to dendritic filtering. In addition, CB1 activation significantly reduced the amplitude of the postsynaptic currents in each cell pair tested. Our data suggest that CB1‐expressing interneurons with different axonal projections have comparable physiological characteristics, contributing to a similar proportion of GABAergic inputs along the somato‐dendritic axis of CA3 pyramidal cells. © 2014 Wiley Periodicals, Inc.
Mitochondrial tricarboxylate and dicarboxylate–Tricarboxylate carriers: from animals to plants
Authors: Dolce Vincenza , Cappello Anna Rita , Capobianco Loredana 
Published: July 2014

AbstractThe citrate carrier (CiC), characteristic of animals, and the dicarboxylate–tricarboxylate carrier (DTC), characteristic of plants and protozoa, belong to the mitochondrial carrier protein family whose members are responsible for the exchange of metabolites, cofactors, and nucleotides between the cytoplasm and the mitochondrial matrix. Most of the functional data on these transporters are obtained from the studies performed with the protein purified from rat, eel yeast, and maize mitochondria or recombinant proteins from different sources incorporated into phospholipid vesicles (liposomes). The functional data indicate that CiC is responsible for the efflux of acetyl‐CoA from the mitochondria to the cytosol in the form of citrate, the primer for fatty acid, cholesterol synthesis, and histone acetylation. Like the CiC, the citrate exported by DTC from the mitochondria to the cytosol in exchange for oxaloacetate can be cleaved by citrate lyase to acetyl‐CoA and oxaloacetate and used for fatty acid elongation and isoprenoid synthesis. In addition to its role in fatty acid synthesis, CiC is involved in other processes such as gluconeogenesis, insulin secretion, inflammation, and cancer progression, whereas DTC is involved in the production of glycerate, nitrogen assimilation, ripening of fruits, ATP synthesis, and sustaining of respiratory flux in fruit cells. This review provides an assessment of the current understanding of CiC and DTC structural and biochemical characteristics, underlying the structure–function relationship of these carriers. Furthermore, a phylogenetic relationship between CiC and DTC is proposed. © 2014 IUBMB Life, 66(7):462–471, 2014
Toxicity of new emerging pollutant tris‐(2,3‐dibromopropyl) isocyanurate on BALB/c mice
Authors: Li Juan , Zhang Xu , Bao Jieqing , Liu Yuchen , Li Junfeng , Li Jia , Liang Yong , Zhang Jie , Zhang Aiqian 
Published: July 2014

AbstractThe emerging heterocyclic brominated flame retardant tris‐(2,3‐dibromopropyl) isocyanurate (TBC), widely used in reinforced plastics, has demonstrated toxicity to fish. However, little is known about its toxicity in rodents. This study aims to determine the effect of TBC on growth, biochemical parameters in serum, organs and related gene expression of both male and female BALB/c mice after gastro‐gavage administration of 0, 2, 10 and 50 mg kg−1 TBC for 28 days. Results indicated that exposure to TBC had no effects on basic growth and food intake of mice, but significantly increased serum alanine aminotransferase levels in male mice. Histopathological analyses showed that focal necrosis (2, 10 and 50 mg kg−1 TBC‐exposed groups) and ballooning degeneration (10 and 50 mg kg−1 TBC‐exposed groups) were found in mouse liver, whereas transmission electron microscopy revealed dose‐dependent hepatocyte apoptosis, mitochondrial degeneration and endoplasmic reticulum dilation. Histopathological and ultrastructural assessments in the lung showed dose‐dependent hyperplasia of pulmonary alveolar epithelium, bronchial congestion, infiltration of inflammatory cells and mitochondrial swelling following TBC exposure. Our results also indicated that mitochondria are one of the major target cytoplasmic organelles for TBC, suggesting that damage in mitochondria is one of the pathways that led to toxic effects in the liver and lung of TBC‐treated groups. Moreover, TBC effectively activated the gene expression of p53 in mice liver. Our findings provide strong evidence that TBC induces significant toxicity in mice organs, especially in liver and lung, which play vital roles in detoxification and gas exchange, respectively. This research will contribute to characterize the toxic effects of TBC, which was introduced as one of the candidates for brominated flame retardant replacement. Copyright © 2014 John Wiley & Sons, Ltd.
Use of three‐dimensional power doppler sonography in the diagnosis of uterine arteriovenous malformation and follow‐up after uterine artery embolization: Case report and brief review of literature
Authors: Tullius Thomas G. , Ross Jason Robert , Flores Melanie , Ghaleb Melhem , Kupesic Plavsic Sanja 
Published: July 2014

ABSTRACTArteriovenous malformations (AVM) of the uterus can cause life‐threatening hemorrhage. Unexplained, heavy vaginal bleeding in a reproductive age woman should raise suspicion for an AVM. Here a 37‐year‐old woman had increasingly severe vaginal bleeding for 15 days. Serum β‐hCG was elevated. Two‐dimensional transvaginal ultrasound suggested retained products of conception. Before dilation and curettage (D&C), color Doppler and three‐dimensional (3D) power Doppler demonstrated findings indicative of uterine AVM. A bilateral uterine artery embolization was performed without complications. Three months after uterine artery embolization, 3D power Doppler ultrasonography found complete resolution of the AVM. This case illustrates the importance of assessing both gray‐scale and 3D power Doppler, and the ability of postprocedure Doppler to assess resolution. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:327–334, 2015
A g‐factor metric for k‐t‐GRAPPA‐ and PEAK‐GRAPPA‐based parallel imaging
Authors: Ramb Rebecca , Binter Christian , Schultz Gerrit , Assländer Jakob , Breuer Felix , Zaitsev Maxim , Kozerke Sebastian , Jung Bernd 
Published: July 2014

PurposeThe aim of this work is to derive a theoretical framework for quantitative noise and temporal fidelity analysis of time‐resolved k‐space‐based parallel imaging methods.TheoryAn analytical formalism of noise distribution is derived extending the existing g‐factor formulation for nontime‐resolved generalized autocalibrating partially parallel acquisition (GRAPPA) to time‐resolved k‐space‐based methods. The noise analysis considers temporal noise correlations and is further accompanied by a temporal filtering analysis.MethodsAll methods are derived and presented for k‐t‐GRAPPA and PEAK‐GRAPPA. A sliding window reconstruction and nontime‐resolved GRAPPA are taken as a reference. Statistical validation is based on series of pseudoreplica images. The analysis is demonstrated on a short‐axis cardiac CINE dataset.ResultsThe superior signal‐to‐noise performance of time‐resolved over nontime‐resolved parallel imaging methods at the expense of temporal frequency filtering is analytically confirmed. Further, different temporal frequency filter characteristics of k‐t‐GRAPPA, PEAK‐GRAPPA, and sliding window are revealed.ConclusionThe proposed analysis of noise behavior and temporal fidelity establishes a theoretical basis for a quantitative evaluation of time‐resolved reconstruction methods. Therefore, the presented theory allows for comparison between time‐resolved parallel imaging methods and also nontime‐resolved methods. Magn Reson Med 74:125–135, 2015. © 2014 Wiley Periodicals, Inc.
Influences of face, stigma, and psychological symptoms on help‐seeking attitudes in Macao
Authors: Cheang Sut Ieng , Davis J. Mark 
Published: July 2014

AbstractThe purpose of this study was to examine the relationships between concerns about loss of face, stigma, psychological symptoms, and attitudes toward seeking mental health services such as counseling in Macao. Participants included 391 students attending the largest public university in Macao: 277 were from Macao and 114 were from Mainland China. Participants completed questionnaires measuring attitudes toward seeking professional psychological help, concerns about loss of face, self‐stigma, public‐stigma, and psychological symptoms. Results showed that positive attitudes toward help‐seeking were significantly negatively correlated with self‐stigma, public‐stigma, and concerns about loss of face but there was no significant correlation with psychological symptoms. Psychological symptoms were positively correlated with face concerns, self‐stigma, and public‐stigma. Stigma (self and public) was found to be significantly positively associated with face concerns, but the correlations were weak. Findings also showed that Macao students had higher levels of distress, and endorsed greater self‐ and public‐stigma than Mainland Chinese students; however, the groups did not differ in face concerns or attitudes toward help‐seeking. Regression analysis indicated that group membership was not a significant predictor of help‐seeking. Self‐stigma was the strongest predictor of professional help‐seeking. Age and sex were also found to be significant predictors. Results suggested that younger students were more likely to seek help and that female students reported greater levels of distress and tended to have more positive attitudes toward seeking psychological services than male students.
Molecular determinants of tetramerization in the KcsA cytoplasmic domain
Authors: Kamnesky Guy , Hirschhorn Orel , Shaked Hadassa , Chen Jingfei , Yao Lishan , Chill Jordan H. 
Published: July 2014

AbstractThe cytoplasmic C‐terminal domain (CTD) of KcsA, a bacterial homotetrameric potassium channel, is an amphiphilic domain that forms a helical bundle with four‐fold symmetry mediated by hydrophobic and electrostatic interactions. Previously we have established that a CTD‐derived 34‐residue peptide associates into a tetramer in a pH‐dependent manner (Kamnesky et al., JMB 2012;418:237‐247). Here we further investigate the molecular determinants of tetramer formation in the CTD by characterizing the kinetics of monomer‐tetramer equilibrium for 10 alanine mutants using NMR, sedimentation equilibrium (SE) and molecular dynamics simulation. NMR and SE concur in finding single‐residue contributions to tetramer stability to be in the 0.5 to 3.5 kcal/mol range. Hydrophobic interactions between residues lining the tetramer core generally contributed more to formation of tetramer than electrostatic interactions between residues R147, D149 and E152. In particular, alanine replacement of residue R147, a key contributor to inter‐subunit salt bridges, resulted in only a minor effect on tetramer dissociation. Mutations outside of the inter‐subunit interface also influenced tetramer stability by affecting the tetramerization on‐rate, possibly by changing the inherent helical propensity of the peptide. These findings are interpreted in the context of established paradigms of protein‐protein interactions and protein folding, and lay the groundwork for further studies of the CTD in full‐length KcsA channels.
A pragmatic approach to wind farm simulations using the dynamic wake meandering model
Authors: Keck Rolf‐Erik , Undheim Ove 
Published: July 2014

AbstractThis paper presents a computationally efficient method for using the dynamic wake meandering model to conduct simulations of wind farm power production. The method is based on creating a database, which contains the time and rotor‐averaged wake effect at any point downstream of a wake‐emitting turbine operating in arbitrary ambient conditions and at an arbitrary degree of wake influence. This database is later used as a look‐up table at runtime to estimate the operating conditions at all turbines in the wind farm, thus eliminating the need to run the dynamic wake meandering model at runtime.By using the proposed method, the time required to conduct wind farm simulations is reduced by three orders of magnitude compared with running the standalone dynamic wake meandering model at runtime. As a result, the wind farm production dynamics for a farm of 100 turbines at 10,000 different sets of ambient conditions run on a normal laptop in 1 h.The method is validated against full scale measurements from the Smøla and OWEZ wind farms, and fair agreement is achieved. Copyright © 2014 John Wiley & Sons, Ltd.
Rapid optimization of stall‐regulated wind turbine blades using a frequency‐domain method: Part 1, loads analysis
Authors: Merz Karl O. 
Published: July 2014

AbstractA fast and effective loads analysis method was developed for the preliminary design of stall‐regulated blades. Calculations are conducted in the frequency domain, including a three‐dimensional representation of turbulence, for a rapid evaluation of lifetime loads. The structural model is simplified, consisting of a single flexible blade on a rigid drivetrain. Load cases are defined which consider ultimate, extreme operating (with and without tip brake deployment), and lifetime fatigue loads. It is shown, by comparison with time‐domain simulations, that the load cases provide a reasonable estimate of design‐driving loads. The method described in Part 1 of this article forms the basis for a novel optimization method in Part 2. Copyright © 2014 John Wiley & Sons, Ltd.
Ontogenetic niche shifts matter in community ecology: a review and future perspectives
Authors: Nakazawa Takefumi 
Published: July 2014

AbstractAlmost all organisms on Earth exhibit ontogenetic niche shifts, which causes great phenotypic variation among individuals and is thus considered to critically mediate community structure and dynamics. In contrast, community ecology has traditionally assumed that species are composed of identical individuals with invariant traits and ignored the potentially important ecological roles of ontogenetic niche shifts. To bridge the gap, here I briefly review ecologically relevant examples which show that basic insights of species‐based community theories can be revised by including the ontogenetic perspective. Specifically, I focus on the most representative animals in the study of ontogenetic niche shifts, i.e., fish, insects, and amphibians. Notably, their ontogenetic niche shifts create novel views of community structure: (1) ontogenetic diet shifts of predatory fish couple pelagic and benthic food webs in aquatic systems, (2) ontogenetic shifts in interaction types of pollinating insects couple herbivory and pollination networks in terrestrial systems, and (3) ontogenetic habitat shifts of amphibians and aquatic insects couple aquatic and terrestrial metacommunities at interface areas. Dynamic models of such stage‐structured communities suggest that their ontogenetic niche shifts may affect the community resilience and disturbance responses. Exploring more complex systems (e.g., where many species undergo ontogenetic niche shifts several times or continuously) is a future direction, for which describing body size relationships between interacting organisms would be a promising approach. I conclude that both theoretical and empirical advances are needed to facilitate the ontogenetic perspective for better understanding mechanisms underlying biodiversity and ecosystem functioning which are increasingly threatened by anthropogenic disturbance.
Secretion expression of SOD1 and its overlapping function with GSH in brewing yeast strain for better flavor and anti-aging ability
Authors: Wang Zhaoyue , Bai Xuejing , He Xiuping , Zhang Borun 
Published: July 2014

Abstract
Superoxide dismutase (SOD) is a significant antioxidant, but unlike glutathione (GSH), SOD cannot be secreted into beer by yeast cells during fermentation, this directly leads to the limited application of SOD in beer anti-aging. In this investigation, we constructed the SOD1 secretion cassette in which strong promoter PGK1p and the sequence of secreting signal factor from Saccharomyces cerevisiae were both harbored to the upstream of coding sequence of SOD1 gene, as a result, the obtained strains carrying this cassette successfully realized the secretion of SOD1. In order to overcome the limitation of previous genetic modification on yeast strains, one new comprehensive strategy was adopted targeting the suitable homologous sites by gene deletion and SOD1 + GSH1 co-overexpression, and the new strain ST31 (Δadh2::SOD1 + Δilv2::GSH1) was constructed. The results of the pilot-scale fermentation showed that the diacetyl content of ST31 was lower by 42 % than that of the host, and the acetaldehyde content decreased by 29 %, the GSH content in the fermenting liquor of ST31 increased by 29 % compared with the host. Both SOD activity test and the positive and negative staining assay after native PAGE indicated that the secreted active SOD in the fermenting liquor of ST31 was mainly a dimer with the size of 32,500 Da. The anti-aging indexes such as the thiobarbituric acid and the resistance staling value further proved that the flavor stability of the beer brewed with strain ST31 was not only better than that of the original strain, but also better than that of the previous engineering strains. The multi-modification and comprehensive improvement of the beer yeast strain would greatly enhance beer quality than ever, and the self-cloning strain would be attractive to the public due to its bio-safety.
Identification and characterization of a short-chain acyl dehydrogenase from Klebsiella pneumoniae and its application for high-level production of l-2,3-butanediol
Authors: Park Jang Min , Hong Won-Kyung , Lee Sung-Mok , Heo Sun-Yeon , Jung You Ree , Kang In Yeong , Oh Baek-Rock , Seo Jeong-Woo , Kim Chul Ho 
Published: July 2014

Abstract
Klebsiella pneumoniae synthesize large amounts of l-2,3-butanediol (l-2,3-BD), but the underlying mechanism has been unknown. In this study, we provide the first identification and characterization of an l-2,3-BD dehydrogenase from K. pneumoniae, demonstrating its reductive activities toward diacetyl and acetoin, and oxidative activity toward l-2,3-BD. Optimum pH, temperature, and kinetics determined for reductive and oxidative reactions support the preferential production of 2,3-BD during cell growth. Synthesis of l-2,3-BD was remarkably enhanced by increasing gene dosage, reaching levels that, to the best of our knowledge, are the highest achieved to date.
Using evidence to drive action: A “revolution in accountability” to implement quality care for better maternal and newborn health in Africa
Authors: Hulton Louise , Matthews Zoe , Martin‐Hilber Adriane , Adanu Richard , Ferla Craig , Getachew Atnafu , Makwenda Charles , Segun Babatunde , Yilla Mohamed 
Published: July 2014

AbstractIntroducing evidence‐based accountability mechanisms at national and subnational levels into maternal newborn health programs can accelerate reductions in maternal and newborn mortality. Clearly packaged evidence has the potential to catalyze change, if it is communicated not only to the public but also to key policymakers. Evidence for Action (E4A) is a DFID‐funded program that contributes to global efforts toward improving accountability in maternal and neonatal health. It uses evidence to drive action and accountability to improve maternal and newborn survival in six African countries: Ethiopia, Ghana, Malawi, Nigeria, Sierra Leone, and Tanzania. This paper introduces the E4A program, the rationale that underpins the program design, and presents initial findings on how information and data currently feed into accountability and implementation across the six E4A countries.