bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐scan MRI with exceptional resilience to field heterogeneities
Authors: Zhang Zhiyong , Seginer Amir , Frydman Lucio 
Published: February 2016

PurposeSingle‐scan two‐dimensional MRI has been generally constrained to acquisitions in high quality magnets. This study introduces a methodology, cross‐term spatiotemporal encoding (xSPEN), that delivers such images under much poorer external field conditions.MethodsxSPEN departs from conventional k‐space scanning, by relying on spatiotemporally encoding the image being sought. Unlike hitherto proposed SPEN methods, however, xSPEN's image readout does not take place using a field gradient along the direction being probed, but rather with the aid of an ancillary source of inhomogeneous frequency broadening. This ancillary dimension was here imposed by an orthogonal field gradient; for example, images along the “y” axis were read out by application of a “z” gradient. The principles and characteristics of this new approach, compatible with existing scanners and free from the need to collect auxiliary information such as field maps, are presented and discussed.ResultsSingle‐ and multi‐slice in vitro, ex vivo, and in vivo MRI experiments, confirmed the unusual resilience of this new single‐shot MRI method to multiple chemical sites on phantoms, animals and humans.ConclusionxSPEN can deliver single‐scan MRI with good sensitivity and exceptional resilience to field inhomogeneities. This could enable investigations that have hitherto escaped from MRI's scope. Magn Reson Med 77:623–634, 2017. © 2016 International Society for Magnetic Resonance in Medicine
A multisample dissolution dynamic nuclear polarization system for serial injections in small animals
Authors: Krajewski Marcin , Wespi Patrick , Busch Julia , Wissmann Lukas , Kwiatkowski Grzegorz , Steinhauser Jonas , Batel Michael , Ernst Matthias , Kozerke Sebastian 
Published: February 2016

PurposeSeveral in vivo applications of dissolution dynamic nuclear polarization (DNP) require rapid successive injections of hyperpolarized substrates. Here we present the design and performance of a custom‐built multisample dissolution DNP setup for small animal research.MethodsThe DNP setup consists of a commercial wide‐bore magnet charged to 3.35 T, a cryostat, a 94‐GHz microwave source, and a custom‐built skeleton that accommodates four identical sample sticks. Each sample stick features a dissolver locked into the skeleton port and a lifter, which permits moving the sample cup out of the liquid helium bath for dissolution.ResultsThe dissolution of the first sample was triggered after 2 hours of polarization buildup during single‐shot operation of the cryostat. Thereafter, a time window of 75–90 min was available to dissolve the remaining three polarized samples. The average liquid state polarization over all four sticks was measured as 18.7% ± 2.3% for [1‐13C] pyruvate 30 s after dissolution. In vivo applicability of the setup using serial injections of [1‐13C] pyruvate to study cardiac metabolism in rats revealed good reproducibility.ConclusionThe proposed four‐sample DNP insert provides reproducible liquid state polarization of [1‐13C] pyruvate and allows for rapid repeat injections in small animals. Magn Reson Med 77:904–910, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Convex optimized diffusion encoding (CODE) gradient waveforms for minimum echo time and bulk motion–compensated diffusion‐weighted MRI
Authors: Aliotta Eric , Wu Holden H. , Ennis Daniel B. 
Published: February 2016

PurposeTo evaluate convex optimized diffusion encoding (CODE) gradient waveforms for minimum echo time and bulk motion–compensated diffusion‐weighted imaging (DWI).MethodsDiffusion‐encoding gradient waveforms were designed for a range of b‐values and spatial resolutions with and without motion compensation using the CODE framework. CODE, first moment (M1) nulled CODE‐M1, and first and second moment (M2) nulled CODE‐M1M2 were used to acquire neuro, liver, and cardiac ADC maps in healthy subjects (n=10) that were compared respectively to monopolar (MONO), BIPOLAR (M1 = 0), and motion‐compensated (MOCO, M1 + M2 = 0) diffusion encoding.ResultsCODE significantly improved the SNR of neuro ADC maps compared with MONO (19.5 ± 2.5 versus 14.5 ± 1.9). CODE‐M1 liver ADCs were significantly lower (1.3 ± 0.1 versus 1.8 ± 0.3 × 10−3 mm2/s, ie, less motion corrupted) and more spatially uniform (6% versus 55% ROI difference) than MONO and had higher SNR than BIPOLAR (SNR = 14.9 ± 5.3 versus 8.0 ± 3.1). CODE‐M1M2 cardiac ADCs were significantly lower than MONO (1.9 ± 0.6 versus 3.8 ± 0.3 x10−3 mm2/s) throughout the cardiac cycle and had higher SNR than MOCO at systole (9.1 ± 3.9 versus 7.0 ± 2.6) while reporting similar ADCs (1.5 ± 0.2 versus 1.4 ± 0.6 × 10−3 mm2/s).ConclusionsCODE significantly improved SNR for ADC mapping in the brain, liver and heart, and significantly improved DWI bulk motion robustness in the liver and heart. Magn Reson Med 77:717–729, 2017. © 2016 International Society for Magnetic Resonance in Medicine
Dynamic control plane management for software‐defined networks
Authors: Li Jian , Yoo Jae‐Hyoung , Hong James Won‐Ki 
Published: February 2016

SummarySoftware‐defined network (SDN) is an emerging network paradigm that allows flexible network management by providing programmability from a separated control plane. Because of the centralized management scheme that SDN adopts, intensive control plane overhead incurs as the scale of SDN increases. The control plane overhead is mainly caused by a massive amount of control messages generated during data plane monitoring and reactive flow instantiation. By far, very few works have addressed the overhead issue on reaction flow instantiation; therefore, we mainly focus on alleviating such overhead in this work. To achieve this goal, we propose a new control plane management (CPMan) method. CPMan aims to realize the following two objectives: first, reduce the number of control messages exchanged through the control channel and second, evenly distribute the control workload across multiple controllers to mitigate the potential performance bottleneck. To realize the former, we propose a lightweight feedback loop‐based control scheme, whereas for the latter, we propose a dynamic switch‐to‐controller (DSC) placement scheme. To show the feasibility of our proposal, we implemented a prototype of the two proposed schemes on top of a carrier‐grade SDN controller and validated its performance in an emulated network. We achieved approximately 57.13% overhead reduction with feedback loop‐based control scheme, while achieved approximately 98.68% balance ratio with DSC placement scheme. Copyright © 2016 John Wiley & Sons, Ltd.
Alkali Metal Cation versus Proton and Methyl Cation Affinities: Structure and Bonding Mechanism
Authors: Boughlala Zakaria , Fonseca Guerra Célia , Bickelhaupt F. Matthias 
Published: February 2016

AbstractWe have analyzed the structure and bonding of gas‐phase Cl−X and [HCl−X]+ complexes for X+= H+, CH3+, Li+, and Na+, using relativistic density functional theory (DFT). We wish to establish a quantitative trend in affinities of the anionic and neutral Lewis bases Cl− and HCl for the various cations. The Cl−X bond becomes longer and weaker along X+ = H+, CH3+, Li+, and Na+. Our main purpose is to understand the heterolytic bonding mechanism behind the intrinsic (i.e., in the absence of solvent) alkali metal cation affinities (AMCA) and how this compares with and differs from those of the proton affinity (PA) and methyl cation affinity (MCA). Our analyses are based on Kohn–Sham molecular orbital (KS‐MO) theory in combination with a quantitative energy decomposition analysis (EDA) that pinpoints the importance of the different features in the bonding mechanism. Orbital overlap appears to play an important role in determining the trend in cation affinities.
The role of nanoparticle inks in determining the performance of solution processed Cu2ZnSn(S,Se)4 thin film solar cells
Authors: Qu Yongtao , Zoppi Guillaume , Beattie Neil S. 
Published: February 2016

AbstractCu2ZnSnS4 (CZTS) nanoparticle inks synthesized by the injection of metal precursors into a hot surfactant offer an attractive route to the fabrication of Earth‐abundant Cu2ZnSn(S,Se)4 (CZTSSe) thin film photovoltaic absorber layers. In this work it is shown that the chemical reaction conditions used to produce CZTS nanoparticle inks have a fundamental influence on the performance of thin film solar cells made by converting the nanoparticles to large CZTSSe grains in a selenium rich atmosphere and subsequent cell completion. The reaction time, temperature and cooling rate of the nanoparticle fabrication process are found to affect doping level, secondary phases and crystal structure respectively. Specifically, prolonging the reaction offers a new route to increase the concentration of acceptor levels in CZTSSe photovoltaic absorbers and results in higher device efficiency through an increase in the open circuit voltage and a reduction in parasitic resistance. Quenching the reaction by rapid cooling introduces a wurtzite crystal structure in the nanoparticles which significantly degrades the device performance, while elevating the reaction temperature of the nanoparticle synthesis introduces a secondary phase Cu2SnS3 in the nanoparticles and results in the highest cell efficiency of 6.26%. This is correlated with increased doping in the CZTSSe absorber and the results demonstrate a route to controlling this parameter. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons, Ltd.
Effects of Na‐sulfopropyl groups on the mechanical properties and morphology of polystyrene‐co‐methacrylate ionomers
Authors: Ko Kwang‐Hwan , Luqman Mohammad , Kim Young‐Wun , Kim Joon‐Seop 
Published: February 2016

ABSTRACTThe dynamic mechanical properties and morphology of poly(styrene‐co−3‐sulfopropyl sodium‐methacrylate) SSPMANa ionomers were investigated. It was found the increasing rate of ionic moduli of the SSPMANa ionomer was very low, and the clusterTgof the ionomers remained more or less constant with increasing ion content. A well‐developed SAXS peak was seen for low ion content SSPMANa ionomers and the peak position changed slightly with ion content. Thus, it was suggested that the presence of the alkyl ester side chains made the ion pairs form multiplets more easily at their prevalent distances, and the small‐agglomerated multiplets were dispersed in the polymer matrix relatively evenly. The interpretation of ionic moduli using a number of theories implied that the multiplets and clusters acted as effective crosslinks and filler particles, respectively, and the size and shape of the clusters were irregular. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2016,54, 1043–1053
Indirect phase transition of TiC, ZrC, and HfC crystal structures
Authors: Abavare Eric K. K. , Dodoo Samuel N. A. , Uchida Kazuyuki , Nkurumah‐Buandoh George K. , Yaya Abu , Oshiyama Atsushi 
Published: February 2016

AbstractWe have performed first‐principles calculations to analyze the electronic structures, static, and dynamical structural stabilities of the pressure‐induced phase transformation of refractory compounds (transition‐metal carbides) from NaCl‐type (B1) to CsCl‐type (B2) via zinc‐blende phase using the plane‐wave pseudopotential approach in the framework of the generalized gradient approximation (GGA) for the exchange and correlation functional. The ground‐state properties, equilibrium lattice constant, bulk moduli, and band structures are determined for the stoichiometry of the compounds and compared with known experimental and theoretical values. We find that the phase‐transition pressure for the indirect phase transition from B1B2 via zinc‐blende structure is about 17‐fold for TiC, 12‐fold for both ZrC and HfC, respectively, when compared with the direct phase transition. Calculated phonon instability exists for the CsCl‐B2 phase, which can prevent the structures from forming and contrary to the zinc‐blende and the NaCl‐B1 phases. The band dispersion and electronic density of states for B1 and B2 crystal phases were explored and found to indicate metallic character in contrast with the zinc‐blende phase, which has a pseudogap opening in the bandgap region suggesting a semiconducting property and also a frequency gap in the phonon spectrum.
Introduction
Authors: Bado Souleymane , Forster Brian P. , Ghanim Abdelbagi M. A. , Jankowicz-Cieslak Joanna , Berthold Günter , Luxiang Liu 
Published: February 2016

AbstractSalinity is a major abiotic stress limiting crop yields in many parts of the world. The FAO (Food and Agriculture Organization) Land and Plant Nutrition Management service estimates that over 400 million hectares (6 %) of the Earth’s land is affected by salt. Breeding for salt tolerance is a major goal for cereal researchers for which screens are required to select out tolerant lines. Screening for salt tolerance in the field is difficult as soil salinity is dynamic, the level of salt varies both horizontally and vertically in the soil profile and changes with time. These environmental perturbations can be overcome by testing in hydroponic system where the testing environment is controlled.
Protocol for measuring soil salinity
Authors: Bado Souleymane , Forster Brian P. , Ghanim Abdelbagi M. A. , Jankowicz-Cieslak Joanna , Berthold Günter , Luxiang Liu 
Published: February 2016

AbstractA simple protocol is described that tests soil salinity. Water-soluble salts are extracted from soil samples and salt content measured. Accurate field evaluations require sampling at various field locations and various depths and over time take into account the crop species to be grown. Instruments and reagents are listed in preparing soil–water extracts and for measuring salt content. Two methods are provided in measuring salt content, by weight and by electrical conductivity.
Impact of Genomic Counseling on Informed Decision‐Making among ostensibly Healthy Individuals Seeking Personal Genome Sequencing: the HealthSeq Project
Authors: Suckiel Sabrina A. , Linderman Michael D. , Sanderson Saskia C. , Diaz George A. , Wasserstein Melissa , Kasarskis Andrew , Schadt Eric E. , Zinberg Randi E. 
Published: February 2016

AbstractPersonal genome sequencing is increasingly utilized by healthy individuals for predispositional screening and other applications. However, little is known about the impact of ‘genomic counseling’ on informed decision‐making in this context. Our primary aim was to compare measures of participants’ informed decision‐making before and after genomic counseling in the HealthSeq project, a longitudinal cohort study of individuals receiving personal results from whole genome sequencing (WGS). Our secondary aims were to assess the impact of the counseling on WGS knowledge and concerns, and to explore participants’ satisfaction with the counseling. Questionnaires were administered to participants (n = 35) before and after their pre‐test genomic counseling appointment. Informed decision‐making was measured using the Decisional Conflict Scale (DCS) and the Satisfaction with Decision Scale (SDS). DCS scores decreased after genomic counseling (mean: 11.34 before vs. 5.94 after; z = −4.34, p < 0.001, r = 0.52), and SDS scores increased (mean: 27.91 vs. 29.06 respectively; z = 2.91, p = 0.004, r = 0.35). Satisfaction with counseling was high (mean (SD) = 26.91 (2.68), on a scale where 6 = low and 30 = high satisfaction). HealthSeq participants felt that their decision regarding receiving personal results from WGS was more informed after genomic counseling. Further research comparing the impact of different genomic counseling models is needed.
The impact of the Ponseti treatment method on parents and caregivers of children with clubfoot: A comparison of two urban populations in Europe and Africa
Authors: Malagelada Francesc , Mayet Sadia , Firth Greg , Ramachandran Manoj 
Published: February 2016

Purpose With the Ponseti treatment method established as the gold standard, children with clubfeet face a prolonged treatment regime that might impact on their families. We aimed to determine how Ponseti treatment influences the lives of parents and caregivers and what coping strategies they use. Secondarily, we aimed to identify any potential differences between two urban referral centres for clubfoot. Methods A total of 115 parents of children affected with idiopathic clubfoot were recruited and included in two groups: one from the United Kingdom (UK) and the other from South Africa (SA). The participants completed the following three instruments: the Impact on Family Scale (IOFS), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Brief COPE. Results During the bracing phase, the IOFS showed a trend towards lower scores when compared to the casting phase for both cohorts ( p = 0.247 and p = 0.434, respectively). The SA population scored higher than the UK in the MSPSS in both casting ( p = 0.002) and bracing phases ( p = 0.004) and used coping strategies at a significantly higher level when compared to the UK population ( p < 0.05) in both treatment phases. Conclusion This is the first study to show that Ponseti treatment for clubfoot causes an impact on family function. In SA, perceived social support is higher and coping strategies are used more often than in the UK to deal with the stressful circumstances of treatment.
Ambulance referral for emergency obstetric care in remote settings
Authors: Tsegaye Ademe , Somigliana Edgardo , Alemayehu Tadesse , Calia Federico , Maroli Massimo , Barban Paola , Manenti Fabio , Putoto Giovanni , Accorsi Sandro 
Published: February 2016

AbstractObjectiveTo evaluate the functionality of an ambulance service dedicated to emergency obstetric care (EmOC) that referred pregnant women to health centers for delivery assistance or to a hospital for the management of obstetric complications.MethodsA retrospective study investigated an ambulance referral system for EmOC in a rural area of Ethiopia between July 1 and December 31, 2013. The service was available 24 h a day and was free of charge. Women requesting referral were transported to nearby health centers. Assistance was provided locally for uncomplicated deliveries. Women with obstetric complications were referred from health centers to a hospital.ResultsA total of 528 ambulance referrals were recorded. The majority of patients (314 [59.5%]) were transported from villages to health centers. The remaining individuals were brought to a hospital, having been referred from health centers (179 [33.9%]) or were referred directly from villages owing to hospital proximity (35 [6.6%]). Of the 179 patients referred to the hospital from health centers, 84 (46.9%) were diagnosed with major direct obstetric complications. No maternal deaths were recorded among patients using the ambulance service. The cost of the ambulance service was US$ 18.47 per referred patient.ConclusionsAn ambulance service dedicated to EmOC that interconnected health centers and a hospital facilitated referrals and better utilized local resources.
MARITAL STATUS AS A RISK FACTOR IN LIFE INSURANCE: AN EMPIRICAL STUDY IN TAIWAN
Authors: Wang Hsin Chung , Yue Jack C. , Tsai Yi-Hsuan 
Published: February 2016

AbstractGender and age are the top two risk factors considered in pricing life insurance products. Although it is believed that mortality rates are also related to other factors (e.g. smoking, overweight, and especially marriage), data availability and marketing often limit the possibility of including them. Many studies have shown that married people (particularly men) benefit from the marriage, and generally have lower mortality rates than unmarried people. However, most of these studies used data from a population sample; their results might not apply to the whole population. In this study, we explore if mortality rates differ by marital status using mortality data (1975–2011) from the Taiwan Ministry of the Interior. In order to deal with the problem of small sample sizes in some marital status groups, we use graduation methods to reduce fluctuations in mortality rates. We also use a relational approach to model mortality rates by marital status, and then compare the proposed model with some popular stochastic mortality models. Based on computer simulation, we find that the proposed smoothing methods can reduce fluctuations in mortality estimates between ages, and the relational mortality model has smaller errors in predicting mortality rates by marital status. Analyses of the mortality data from Taiwan show that mortality rates differ significantly by marital status. In some age groups, the differences in mortality rates are larger between marital status groups than between smokers and non-smokers. For the issue of practical consideration, we suggest modifications to include marital status in pricing of life insurance products.
The Zeldovich spontaneous reaction wave propagation concept in the fast/modest heating limits
Authors: Kassoy D. R. 
Published: February 2016

Quantitative mathematical models describe planar, spontaneous, reaction wave propagation (Zeldovich, Combust. Flame, vol. 39, 1980, pp. 211–214) in a finite hot spot volume of reactive gas. The results describe the complete thermomechanical response of the gas to a one-step, high-activation-energy exothermic reaction initiated by a tiny initial temperature non-uniformity in a gas at rest with uniform pressure. Initially, the complete conservation equations, including all transport terms, are non-dimensionalized to identify parameters that quantify the impact of viscosity, conduction and diffusion. The results demonstrate unequivocally that transport terms are tiny relative to all other terms in the equations, given the relevant time and length scales. The asymptotic analyses, based on the reactive Euler equations, describe both induction and post-induction period models for a fast heat release rate (induction time scale short compared to the acoustic time of the spot), as well as a modest heat release rate (induction time scale equivalent to the acoustic time). Analytical results are obtained for the fast heating rate problem and emphasize the physics of near constant-volume heating during the induction period. Weak hot spot expansion is the source of fluid expelled from the original finite volume and is a ‘piston-effect’ source of acoustic mechanical disturbances beyond the spot. The post-induction period is characterized by the explosive appearance of an ephemeral, spatially uniform high-temperature, high-pressure spot embedded in a cold, low-pressure environment. In analogy with a shock tube the subsequent expansion process occurs on the acoustic time scale of the spot and will be the source of shocks propagating beyond the spot. The modest heating rate induction period is characterized by weakly compressible phenomena that can be described by a novel system of linear wave equations for the temperature, pressure and induced velocity perturbations driven by nonlinear chemical heating, which provides physical insights difficult to obtain from the more familiar ‘Clarke equation’. When the heating rate is modest, reaction terms in the post-induction period Euler equations exhibit a form of singular behaviour in the high-activation-energy limit, implying the need to use a nonlinear exponential scaling for time and space, developed originally to describe spatially uniform thermal explosions (Kassoy, Q. J. Mech. Appl. Maths, vol. 30, 1977, pp. 71–89). Here again the result will be the explosive appearance of an ephemeral spatially uniform high-temperature, high-pressure hot spot. These results demonstrate that an initially weak temperature non-uniformity in a finite hot spot can be the source of acoustic and shock wave mechanical disturbances in the gas beyond the spot that may be related to rocket engine instability and engine knock.