bluuebunny/crossref_metadata_2025_split huggingface dataset:
“Click Chemistry” for the Simple Determination of Fatty‐Acid Uptake and Degradation: Revising the Role of Fatty‐Acid Transporters
Authors: Pérez Alexander J. , Bode Helge B. 
Published: May 2015

AbstractFatty acids (FAs) have numerous functions in all living organisms, ranging from structural roles and energy production to the biosynthesis of secondary metabolites. Because of the high energy content of exogenous FAs, their acquisition is central of metabolism, and several biological systems are known, although their precise roles are not yet entirely clear. We investigated the roles of FadD (CoA ligase) and FadL (FA transporter) in different bacterial strains by using an improved version of click‐chemistry‐assisted labelling of azido‐FAs. The high sensitivity of this method allows a direct and precise assessment of FA metabolism, and is thus far better suited than growth experiments. Our results show that although FA activation is indeed essential for FA degradation, their transport can be independent of transporters like FadL.
One Crystal, Two Temperatures: Cryocooling Penalties Alter Ligand Binding to Transient Protein Sites
Authors: Fischer Marcus , Shoichet Brian K. , Fraser James S. 
Published: May 2015

AbstractInterrogating fragment libraries by X‐ray crystallography is a powerful strategy for discovering allosteric ligands for protein targets. Cryocooling of crystals should theoretically increase the fraction of occupied binding sites and decrease radiation damage. However, it might also perturb protein conformations that can be accessed at room temperature. Using data from crystals measured consecutively at room temperature and at cryogenic temperature, we found that transient binding sites could be abolished at the cryogenic temperatures employed by standard approaches. Changing the temperature at which the crystallographic data was collected could provide a deliberate perturbation to the equilibrium of protein conformations and help to visualize hidden sites with great potential to allosterically modulate protein function.
Evaluation of the Impact Personality Disorder Project – A psychologically‐informed consultation, training and mental health collaboration approach to probation offender management
Authors: Clark Susannah , John Chuan Stuart 
Published: May 2015

AbstractBackgroundThe Camden and Islington Impact Personality Disorder Project provided psychologically informed consultation and training to probation staff in a Public Protection Unit and staff in two ‘approved premises’ (probation hostels) working with high‐risk prison sentenced offenders on licence in the community; some direct therapeutic work was also conducted jointly with probation officers. Most of the offenders had behaviours associated with personality disorder, although had not necessarily received a diagnosis of personality disorder.AimsTo evaluate this service (the intervention) and test the hypothesis that its work would be associated with a reduction in recalls to prison.MethodsLocal and national probation records were used to identify all prison recalls made by 10 consistently available probation officers for 1 year before the intervention and up to 3 years after its introduction; reasons for recall and evidence of new arrests or charges were also extracted.ResultsThere was a significant decrease in rate of recalls in the first year of the intervention, sustained over the second year and, for the smaller number of officers still available, also over the third year. Non‐compliance with supervision as a reason for recall was cut by two‐thirds; other reductions were in responses to ‘challenging’ behaviours. There was no evidence of increase in serious further offending.ConclusionsOur findings provide preliminary evidence that psychologically informed practice by probation officers supervising offenders at highest risk of serious harm re‐offending can reduce the rate of recall to prison, a costly alternative to maintaining offenders in the community, without apparently reducing community safety. Further research should clarify the extent to which the intervention helped the officers merely to tolerate challenging behaviours from these offenders and the extent of real change in the behaviours. Copyright © 2015 John Wiley & Sons, Ltd.
β‐Hydrogen Elimination Reactions of Nickel and Palladium Methoxides Stabilised by PCP Pincer Ligands
Authors: Martínez‐Prieto Luis M. , Ávila Elena , Palma Pilar , Álvarez Eleuterio , Cámpora Juan 
Published: May 2015

AbstractNickel and palladium methoxides [(iPrPCP)M‐OMe], which contain the iPrPCP pincer ligand, decompose upon heating to give products of different kinds. The palladium derivative cleanly gives the dimeric Pd0 complex [Pd(μ‐iPrPCHP)]2 (iPrPCHP=2,6‐bis(diisopropylphosphinomethyl)phenyl) and formaldehyde. In contrast, decomposition of [(iPrPCP)Ni‐OMe] affords polynuclear carbonyl phosphine complexes. Both decomposition processes are initiated by β‐hydrogen elimination (BHE), but the resulting [(iPrPCP)M‐H] hydrides undergo divergent reaction sequences that ultimately lead to the irreversible breakdown of the pincer units. Whereas the Pd hydride spontaneously experiences reductive CH coupling, the decay of its Ni analogue is brought about by its reaction with formaldehyde released in the BHE step. Kinetic measurements showed that the BHE reaction is reversible and less favourable for Ni than for Pd for both kinetic and thermodynamic reasons. DFT calculations confirmed the main conclusions of the kinetic studies and provided further insight into the mechanisms of the decomposition reactions.
iShare: Balancing I/O performance isolation and disk I/O efficiency in virtualized environments
Authors: Wu Song , Tao Songqiao , Ling Xiao , Fan Hao , Jin Hai , Ibrahim Shadi 
Published: May 2015

SummaryPerformance isolation has long been a challenging problem for disk resource allocation in virtualized environments. While there have been many researches working on I/O performance isolation and disk utilization, none of them addresses the I/O performance isolation and disk utilization as a whole. To this end, we investigate the impact of current disk I/O performance isolation schemes on disk I/O utilization. Interestingly, our studies report that current isolation schemes bring unnecessary disk idle and reduce the overall disk I/O performance because of ignoring the disk states and characteristics of requests. Accordingly, we propose an adaptive proportional‐share I/O scheduling framework, named iShare, in virtualized environments. iShare not only ensures I/O performance isolation through proportionally allocating time slices according to the weights of virtual machines but also preserves high disk efficiency by detecting disk states and adaptively adjusting the time slice size based on characteristics of requests. We implement a prototype of iShare on the Xen platform. The experimental results show that iShare ensures I/O performance isolation while improving disk I/O efficiency, compared with Blkio (i.e., the default I/O performance isolation method in Xen), iShare increases disk I/O bandwidth by 58% and slightly improves the I/O performance isolation for the sequential write applications. Copyright © 2015 John Wiley & Sons, Ltd.
MPI and UPC broadcast, scatter and gather algorithms in Xeon Phi
Authors: Mallón Damián A. , Taboada Guillermo L. , Koesterke Lars 
Published: May 2015

SummaryAccelerators have revolutionised the high performance computing (HPC) community. Despite their advantages, their very specific programming models and limited communication capabilities have kept them in a supporting role of the main processors. With the introduction of Xeon Phi, this is no longer true, as it can be programmed as the main processor and has direct access to the InfiniBand network adapter. Collective operations play a key role in many HPC applications. Therefore, studying its behaviour in the context of manycore coprocessors has great importance. This work analyses the performance of different algorithms for broadcast, scatter and gather, in a large‐scale Xeon Phi supercomputer. The algorithms evaluated are those available in the reference message passing interface (MPI) implementation for Xeon Phi (Intel MPI), the default algorithm in an optimised MPI implementation (MVAPICH2‐MIC), and a new set of algorithms, developed by the authors of this work, designed with modern processors and new communication features in mind. The latter are implemented in Unified Parallel C (UPC), a partitioned global address space language, leveraging one‐sided communications, hierarchical trees and message pipelining. This study scales the experiments to 15360 cores in the Stampede supercomputer and compares the results to Xeon and hybrid Xeon + Xeon Phi experiments, with up to 19456 cores. Copyright © 2015 John Wiley & Sons, Ltd.
Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation
Authors: Wang Fajun , Lei Sheng , Xu Yao , Ou Junfei 
Published: May 2015

AbstractWe report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low‐surface‐energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.
Photophysical Properties of Intramolecular Charge Transfer in a Tribranched Donor–π–Acceptor Chromophore
Authors: Hu Jiangpu , Li Yang , Zhu Huaning , Qiu Shuhai , He Guiying , Zhu Xiaozhang , Xia Andong 
Published: May 2015

AbstractThe photophysical properties of intramolecular charge transfer (ICT) in a novel tribranched donor–π–acceptor chromophore, triphenoxazine‐2,4,6‐triphenyl‐1,3,5‐triazine (tri‐PXZ‐TRZ), with thermally activated delayed fluorescence character was investigated in different aprotic solvents by steady‐state spectroscopy and femtosecond and nanosecond transient absorption spectroscopy measurements. Increasing the solvent polarity led to a significant increase in the Stokes shift. The large Stokes shift in highly polar solvents was attributed to ICT properties upon excitation; this resulted in a strong interaction between the tri‐PXZ‐TRZ molecule and the surrounding solvent, which led to a strong solvation process. Quantum‐chemical calculations and changes in the dipole moment showed that this compound has a large degree of ICT. Furthermore, an apolar environment helped to preserve the symmetry of tri‐PXZ‐TRZ and to enhance its emission efficiency. The femtosecond and nanosecond transient absorption spectroscopy results indicated that the excited‐state dynamics of this push–pull molecule were strongly influenced by solvent polarity through the formation of a solvent‐stabilized ICT state. The excited‐state relaxation mechanism of tri‐PXZ‐TRZ was proposed by performing target model analysis on the femtosecond transient absorption spectra. In addition, the delayed fluorescence of tri‐PXZ‐TRZ was significantly modulated by a potential competition between solvation and intersystem crossing processes.
Time‐ and Energy‐Efficient Solution Combustion Synthesis of Binary Metal Tungstate Nanoparticles with Enhanced Photocatalytic Activity
Authors: Thomas Abegayl , Janáky Csaba , Samu Gergely F. , Huda Muhammad N. , Sarker Pranab , Liu J. Ping , van Nguyen Vuong , Wang Evelyn H. , Schug Kevin A. , Rajeshwar Krishnan 
Published: May 2015

AbstractIn the search for stable and efficient photocatalysts beyond TiO2, the tungsten‐based oxide semiconductors silver tungstate (Ag2WO4), copper tungstate (CuWO4), and zinc tungstate (ZnWO4) were prepared using solution combustion synthesis (SCS). The tungsten precursor’s influence on the product was of particular relevance to this study, and the most significant effects are highlighted. Each sample’s photocatalytic activity towards methyl orange degradation was studied and benchmarked against their respective commercial oxide sample obtained by solid‐state ceramic synthesis. Based on the results herein, we conclude that SCS is a time‐ and energy‐efficient method to synthesize crystalline binary tungstate nanomaterials even without additional excessive heat treatment. As many of these photocatalysts possess excellent photocatalytic activity, the discussed synthetic strategy may open sustainable materials chemistry avenues to solar energy conversion and environmental remediation.
Graphical analysis and design of multistage operational amplifiers with active feedback Miller compensation
Authors: Tepwimonpetkun Samattachai , Pholpoke Bhirawich , Wattanapanitch Woradorn 
Published: May 2015

SummaryFrequency compensation of a multistage operational amplifier (op‐amp) is normally performed through solving nodal equations of an equivalent circuit to obtain the op‐amp's final transfer function. The process is often very tedious and offers little insight into the roles of the selected compensation scheme. In this paper, we present a graphical design approach for two‐stage and three‐stage op‐amps with active feedback Miller compensation. By viewing frequency compensation as a standard feedback problem, we can utilize the well‐known graphical tools such as the root locus and Bode plot to understand the effects of the compensation and to estimate the locations of the closed‐loop poles and zeros of the op‐amp. Intuitive graphical design procedures for two‐stage and three‐stage op‐amps are also formulated. To show its effectiveness, we illustrate our design approach through the design of a three‐stage op‐amp in a standard 0.18‐μm complementary metal‐oxide‐semiconductor (CMOS) process. With a load capacitance of 500 pF, post‐layout simulations show that the op‐amp achieves a low‐frequency gain of 144 dB, a phase margin of 58∘, and a unity‐gain frequency of 1.38 MHz while consuming a total bias current of 31 μA from a 1.8‐V supply voltage. Comparisons with the published amplifiers show that our op‐amp achieves the figure of merits comparable to those of the state of the art. Copyright © 2015 John Wiley & Sons, Ltd.
Quantitation of yeast cell–cell fusion using multicolor flow cytometry
Authors: Salzman Valentina , Porro Valentina , Bollati‐Fogolín Mariela , Aguilar Pablo S. 
Published: May 2015

AbstractMating of haploid Saccharomyces cerevisiae cells of opposite sex provides a powerful model system to study the cell–cell fusion. However, a rapid and standardized method is much needed for quantitative assessment of fusion efficiency. The gold standard method relies on counting mating pairs in fluorescence microscopy images. This current method is limited by expectancy bias and it is time consuming, restricting the number of both cell–cell fusion events and strains that can be analyzed at once. Automatic approaches present a solution to these limitations. Here, we describe a novel flow cytometric approach that is able to quickly both identify mating pairs within a mixture of gametes and quantify cell fusion efficiency. This method is based on staining the cell wall of yeast populations with different Concanavalin A–fluorophore conjugates. The mating subpopulation is identified as the two‐colored events set and fused and unfused mating pairs are subsequently discriminated by green fluorescent protein bimolecular complementation. A series of experiments was conducted to validate a simple and reliable protocol. Mating efficiency in each sample was determined by flow cytometry and compared with the one obtained with the current gold standard technique. The results show that mating pair counts using both methods produce indistinguishable outcomes and that the flow cytometry‐based method provides quantitative relevant information in a short time, making possible to quickly analyze many different cell populations. In conclusion, our data show multicolor flow cytometry‐based fusion quantitation to be a fast, robust, and reliable method to quantify the cell–cell fusion in yeast. © 2015 International Society for Advancement of Cytometry
An energy‐efficient history‐based routing scheme for opportunistic networks
Authors: Dhurandher Sanjay K. , Sharma Deepak Kumar , Woungang Isaac , Saini Aakanksha 
Published: May 2015

SummaryIn opportunistic networks (Oppnets), nodes rely on contact opportunities between them to exchange information with each other. Routing and forwarding in Oppnets remains a challenging task because of the limited energy and bandwidth constraints. Various routing protocols for Oppnets have been proposed in the literature, but only few of them have explicitly investigated the energy issue. In this paper, some improvements in the already existing history‐based prediction for routing protocol for infrastructure‐less Oppnets (so‐called HBPR) is suggested so as to make it energy efficient. The proposed energy‐efficient HBPR protocol (EHBPR) addresses the energy constraints in HBPR and reduces the number of packets transferred in the network, which in turn results to a reduction in the nodes' energy consumption. Through simulations, the performance of EHBPR in terms of energy consumption is compared against the HBPR and the energy‐efficient n‐epidemic routing protocol. The results show that (1) EHBPR consumes 14.66% less energy than HBPR (respectively 13.14% less energy than n‐epidemic); (2) EHBPR generates 67.4% less dead nodes compared with HBPR (resp. 66.33% less dead nodes compared to n‐epidemic); and (3) EHBPR yields 77.86% less overhead ratio compared with HBPR (resp. 84.49% less overhead ratio compared with n‐epidemic). Copyright © 2015 John Wiley & Sons, Ltd.
Versatile Reactivity of CH3CN‐Coordinated Nickel‐Iron Heterodimetallic Complexes with Cp* Ligand on Diazadithiolate (N2S2) or Dithiadithiolate (S4) Platforms
Authors: Yang Dawei , Li Yang , Su Linan , Wang Baomin , Qu Jingping 
Published: May 2015

AbstractBy using 3,7‐dithianonane‐1,9‐dithiol (S4) and N,N′‐dimethyl‐N,N′‐bis(2‐mercaptoethyl)ethylenediamine (N2S2) as ligands, two CH3CN‐coordinated nickel‐iron heterodimetallic complexes, [NiS4Fe(CH3CN)Cp*][PF6] (1a) and [NiN2S2Fe(CH3CN)Cp*][PF6] (1b) (Cp* = η5‐C5Me5), were synthesized and characterized spectroscopically and crystallographically. Reactivities of 1a and 1b towards CO, CH2Cl2, HBF4, and NOPF6 have also been investigated. A series of complexes coordinated with small molecules [NiS4Fe(L)Cp*][PF6]n [n = 1, L = Cl (2a), CO (3a); n = 2, L = NO (4a)], [NiN2S2Fe(L)Cp*][PF6] [L = Cl (2b), CO (3b)] were obtained. We also studied the redox properties of 2a, 2b, 3a, and 3b by cyclic voltammetry in CH2Cl2 and in CH3CN solution. Complex 3a was found to be an excellent electrocatalyst for proton reduction from HBF4.
Total Synthesis of Myrmekioside A, a Mono‐O‐alkyl‐diglycosylglycerol from Marine Sponge Myrmekioderma sp.
Authors: Zhang Jun , Li Chunxia , Sun Linlin , Yu Guangli , Guan Huashi 
Published: May 2015

AbstractMyrmekioside A, which was isolated from the marine sponge Myrmekioderma sp. as a member of the family of natural mono‐O‐alkyl‐diglycosylglycerols, and which has a strong reversion effect on the tumor cell morphology of ras‐transformed cells at 5 μg/mL, was synthesized for the first time in 17 steps and 14 % overall yield. The β‐glycosidic linkages in myrmekioside A were successfully constructed by the neighbouring‐group‐participation approach using trichloroacetimidates and thioglycosides as glycosyl donors. The 2R absolute configuration at C‐2 of the glycerol backbone was derived from (S)‐1,2‐isopropylideneglycerol (8). This synthetic approach may be applicable to the preparation of other myrmekioside analogues featuring different sugars and alkyl chains for further structure–activity relationship studies.
The mixed blessings of migration: Life satisfaction and self‐esteem over the course of migration
Authors: Lönnqvist Jan‐Erik , Leikas Sointu , Mähönen Tuuli Anna , Jasinskaja‐Lahti Inga 
Published: May 2015

AbstractWe investigated the psychological adaptation of Ingrian–Finnish migrants from Russia to Finland between 2008 and 2013. Pre‐migration data (N = 225) were collected at the Finnish language courses that were part of the immigration training program. The three post‐migration follow‐ups were conducted half a year (N = 155), and 2 (N = 133) and 3 years (N = 85) after migration. Well‐being was assessed with measures of Life Satisfaction and Self‐Esteem. Life Satisfaction increased from pre‐migration to the first post‐migration measurement point, after which it stabilized. Self‐Esteem decreased throughout the study. Variables reflecting adjustment to the event of migration (e.g., acculturation stress, socio‐cultural adaptation) were primarily associated with well‐being at the first post‐migration measurement point. More general determinants of well‐being (e.g., social support and subjective economic situation) were more consistently associated with well‐being throughout the study. The results suggest that migration can be beneficial to some but detrimental to other types of well‐being.
Mediation analysis with structural equation models: Combining theory, design, and statistics
Authors: Danner Daniel , Hagemann Dirk , Fiedler Klaus 
Published: May 2015

AbstractStatistical tests of indirect effects can hardly distinguish between genuine and spurious mediation effects. The present research demonstrates, however, that mediation analysis can be improved by combining a significance test of the indirect effect with assessing the fit of causal models. Testing only the indirect effect can be misleading, because significant results may also be obtained when the underlying causal model is different from the mediation model. We use simulated data to demonstrate that additionally assessing the fit of causal models with structural equation models can be used to exclude subsets of models that are incompatible with the observed data. The results suggest that combining structural equation modeling with appropriate research design and theoretically stringent mediation analysis can improve scientific insights. Finally, we discuss limitations of the structural equation modeling approach, and we emphasize the importance of non‐statistical methods for scientific discovery.
(How) does positive and negative extended cross‐group contact predict direct cross‐group contact and intergroup attitudes?
Authors: Mazziotta Agostino , Rohmann Anette , Wright Stephen C. , De Tezanos‐Pinto Pablo , Lutterbach Sebastian 
Published: May 2015

AbstractKnowing that fellow ingroup members have cross‐group contact can affect how people think, feel, and behave towards an out‐group. Previous research on extended contact focused almost exclusively on positive cross‐group interactions, neglecting the fact that extended contact can also be negative. In this contribution, we introduce negative extended contact and investigate how both forms of extended contact predict direct cross‐group contact and intergroup attitudes. In two cross‐sectional studies (N1 = 286, N2 = 237), we found evidence that positive and negative extended contact uniquely predict intergroup attitudes, and that direct cross‐group contact mediates this effect. In , we also provide initial evidence that extended contact might either prepare for or impair direct contact by changing ingroup norms and intergroup self‐efficacy, which in turn influence feelings of intergroup anxiety.