bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prenatal diagnosis of absent pulmonary valve syndrome from first trimester onwards: novel insights into pathophysiology, associated conditions and outcome
Authors: Gottschalk I. , Jehle C. , Herberg U. , Breuer J. , Brockmeier K. , Bennink G. , Hellmund A. , Strizek B. , Gembruch U. , Geipel A. , Berg C. 
Published: May 2016

ABSTRACTObjectiveTo assess the spectrum of associated anomalies, intrauterine course and outcome in fetuses with absent pulmonary valve syndrome (APVS).MethodsAll cases with a prenatal diagnosis of APVS at two centers over a period of 13 years were analyzed retrospectively. APVS was diagnosed in the presence of rudimentary or dysplastic pulmonary valve leaflets with to‐and‐fro blood flow in the pulmonary trunk on color and pulsed‐wave Doppler ultrasound. Data on demographic characteristics, presence of associated conditions, Doppler studies and pregnancy outcome were reviewed.ResultsDuring the study period, 40 cases of APVS were diagnosed prenatally. Thirty‐seven (92.5%) cases were associated with tetralogy of Fallot (TOF) and three (7.5%) had an intact ventricular septum. Patency of the ductus arteriosus (DA) was found in 17/37 (45.9%) TOF cases and in all three cases with an intact ventricular septum. Mean gestational age at diagnosis was 19.7 (range, 12–34) weeks with 10 (25.0%) cases (all with TOF) diagnosed in the first trimester. TOF was an isolated finding in 15 (37.5%) cases. Chromosomal anomalies, cardiac defects and extracardiac anomalies were present in 18 (45.0%), four (10.0%) and three (7.5%) cases, respectively. Among the 40 cases, there were 19 (47.5%) terminations of pregnancy, six (15.0%) intrauterine deaths, four (10.0%) neonatal deaths and 11 (27.5%) survivors. Patency of the DA, reversed flow during atrial contraction in the ductus venosus, umbilical artery or fetal middle cerebral artery, and hydrops/increased nuchal translucency thickness were significantly associated with non‐survival. All 10 cases diagnosed in the first trimester had a patent DA and abnormal Doppler parameters, eight had hydrops and/or increased nuchal translucency, six were associated with trisomy 13 or 18 and none survived.ConclusionAPVS diagnosed in the first trimester is significantly associated with TOF, patency of the DA, abnormal Doppler parameters, lethal trisomies and intrauterine mortality. Cases of APVS with isolated TOF and agenesis of the DA have a better outcome than those with additional anomalies, with > 80% survival. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.
Kinetic isotope effects in chemical and biochemical reactions: physical basis and theoretical methods of calculation
Authors: González‐Lafont Àngels , Lluch José M. 
Published: May 2016

Kinetic isotope effects (KIEs) are a valuable tool for the analysis of chemical and biochemical reaction mechanisms. Theoretical methods of calculation of those KIEs have been developed with the aim to better understand their experimental behavior. In this review, the physical basis as well as several of those computational approaches to calculate primary hydrogen KIEs is presented. Examples of interesting chemical reactions and relevant enzymatic processes are given to demonstrate how theory is used to interpret those complex kinetic magnitudes. In particular, KIE computations within generalized transition state theory formulations are shown here to explain the temperature dependence of chemical and biochemical KIEs caused by multidimensional quantum effects contributions, such as zero point vibrational energy and quantum tunneling. An unexpected large isotope effect on the phosphorescence emission of an organic reaction is analyzed by means of KIE calculations as a function of energy and including also tunneling corrections. More quantum‐based methodologies such as the Multiconfiguration Time‐Dependent Hartree method and Feynman path integral simulations are discussed within the context of KIE computations. The special kinetic treatment of proton‐coupled electron transfer reactions is also analyzed. WIREs Comput Mol Sci 2016, 6:584–603. doi: 10.1002/wcms.1268This article is categorized under:

Structure and Mechanism > Reaction Mechanisms and Catalysis
Theoretical and Physical Chemistry > Reaction Dynamics and Kinetics
Investigation into the Cause of Spontaneous Emulsification of a Free Steel Droplet; Validation of the Chemical Exchange Pathway
Authors: Spooner Stephen , Assis Andre N. , Warnett Jason , Fruehan Richard , Williams Mark A. , Sridhar Seetharaman 
Published: May 2016

Abstract
Small Fe-based droplets have been heated to a molten phase suspended within a slag medium to replicate a partial environment within the basic oxygen furnace (BOF). The confocal scanning laser microscope (CSLM) has been used as a heating platform to interrogate the effect of impurities and their transfer across the metal/slag interface, on the emulsification of the droplet into the slag medium. The samples were then examined through X-ray computer tomography (XCT) giving the mapping of emulsion dispersion in 3D space, calculating the changing of interfacial area between the two materials, and changes of material volume due to material transfer between metal and slag. Null experiments to rule out thermal gradients being the cause of emulsification have been conducted as well as replication of the previously reported study by Assis et al.[1] which has given insights into the mechanism of emulsification. Finally chemical analysis was conducted to discover the transfer of oxygen to be the cause of emulsification, leading to a new study of a system with undergoing oxygen equilibration.
Study of Rayleigh-backscattering induced coherence collapse in an asymmetric DFB FL sensor
Authors: Liu Wen , Ma Lina , Hu Zhengliang , Feng Ying , Yang Huayong 
Published: May 2016

Abstract
Rayleigh-back scattering induced coherence collapse of an asymmetric distributed feedback fiber laser (DFB FL) sensor is investigated using a composite cavity model. The coherence collapse threshold condition of the asymmetric DFB FL sensor is measured. The DFB FL sensor shows different dynamic behaviors in different pump configurations. According to the asymmetric behavior to the external optical feedback, a novel method to find the actual phase shift position of the asymmetric DFB FL sensor is presented.
SUPPORTING LOCAL FOOD SYSTEM DEVELOPMENT THROUGH FOOD PRICE PREMIUM DONATIONS: A POLICY PROPOSAL
Authors: WILLIS DAVID B. , CARPIO CARLOS E. , BOYS KATHRYN A. 
Published: May 2016

AbstractThis study investigates consumer preferences for a marketing system that improves integration of farmers into a local food system. Attribute-based methods are used to estimate consumer willingness to pay for a locally grown product that is bundled with a local food bank (LFB) donation. Estimates reveal that, on average, households are willing to pay 11% more for locally grown relative to nonlocal agricultural products. When the locally grown product attribute is combined with a donation to support a LFB, the premium nearly doubles. Results suggest that the proposed system could provide resources to strengthen local food distribution networks.
Flap-wise loads reduction of rotor blades by embedded flap-wise absorbers
Authors: Han D. 
Published: May 2016

ABSTRACTElastomeric and Fluidlastic®absorbers are proposed to be embedded in blade cavity to reduce troublesome second harmonic flap-wise blade loads of rigid rotors. A simple model of a blade with a flap-wise dynamic absorber is derived to investigate centrifugal force effects on the absorber's rotating frequency. The system's dynamic equations of motion indicate that centrifugal force has no effect on absorber's frequency under rotation. Aeroelastic simulation of the coupled rotor and absorber system based on an elastic beam model in generalised force formulation is used to explore load reduction extent and dynamic absorber behaviour. At a forward speed of 200 km/h, the elastomeric absorber reduces the second harmonic flap-wise root-bending moment by 88.8% for unacceptably large stroke; the Fluidlastic®absorber reduces the moment by 78.5% with a stroke 4.26% of blade chord length. Results indicate that placing an embedded Fluidlastic®absorber in the blade's flap-wise direction has potential for reducing load in different flight states with relatively small strokes. Increasing tuning port area ratio or Fluidlastic®absorber mass can distinctly decrease strokes without increasing loads. However, deviation from normal rotor speed significantly lowers Fluidlastic®absorber performance.
Inversion of a glacier hydrology model
Authors: Brinkerhoff Douglas J. , Meyer Colin R. , Bueler Ed , Truffer Martin , Bartholomaus Timothy C. 
Published: May 2016

ABSTRACTThe subglacial hydrologic system exerts strong controls on the dynamics of the overlying ice, yet the parameters that govern the evolution of this system are not widely known or observable. To gain a better understanding of these parameters, we invert a spatially averaged model of subglacial hydrology from observations of ice surface velocity and outlet stream discharge at Kennicott Glacier, Wrangell Mountains, AK, USA. To identify independent parameters, we formally non-dimensionalize the forward model. After specifying suitable prior distributions, we use a Markov-chain Monte Carlo algorithm to sample from the distribution of parameter values conditioned on the available data. This procedure gives us not only the most probable parameter values, but also a rigorous estimate of their covariance structure. We find that the opening of cavities due to sliding over basal topography and turbulent melting are of a similar magnitude during periods of large input flux, though turbulent melting also exhibits the greatest uncertainty. We also find that both the storage of water in the englacial system and the exchange of water between englacial and subglacial systems are necessary in order to explain both surface velocity observations and the relative attenuation in the amplitude of diurnal signals between input and output flux observations.
Relationship between the energy dissipation function and the skin friction law in a turbulent channel flow
Authors: Abe Hiroyuki , Anthony Antonia Robert 
Published: May 2016

Integrals of the mean and turbulent energy dissipation rates are examined using direct numerical simulation (DNS) databases in a turbulent channel flow. Four values of the Kármán number ($h^{+}=180$, 395, 640 and 1020;$h$is the channel half-width) are used. Particular attention is given to the functional$h^{+}$dependence by comparing existing DNS and experimental data up to$h^{+}=10^{4}$. The logarithmic$h^{+}$dependence of the integrated turbulent energy dissipation rate is established for$300\leqslant h^{+}\leqslant 10^{4}$, and is intimately linked to the logarithmic skin friction law,viz.$U_{b}^{+}=2.54\ln (h^{+})+2.41$($U_{b}$ is the bulk mean velocity). This latter relationship is established on the basis of energy balances for both the mean and turbulent kinetic energy. When$h^{+}$is smaller than 300, viscosity affects the integrals of both the mean and turbulent energy dissipation rates significantly due to the lack of distinct separation between inner and outer regions. The logarithmic$h^{+}$dependence of$U_{b}^{+}$is clarified through the scaling behaviour of the turbulent energy dissipation rate$\overline{{\it\varepsilon}}$in different parts of the flow. The overlap between inner and outer regions is readily established in the region$30/h^{+}\leqslant y/h\leqslant 0.2$for$h^{+}\geqslant 300$. At large$h^{+}$(${\geqslant}$5000) when the finite Reynolds number effect disappears, the magnitude of$\overline{{\it\varepsilon}}y/U_{{\it\tau}}^{3}$approaches 2.54 near the lower bound of the overlap region. This value is identical between the channel, pipe and boundary layer as a result of similarity in the constant stress region. As$h^{+}$becomes large, the overlap region tends to contribute exclusively to the$2.54\ln (h^{+})$dependence of the integrated turbulent energy dissipation rate. The present logarithmic$h^{+}$dependence of$U_{b}^{+}$is essentially linked to the overlap region, even at small$h^{+}$.
Squirmers with swirl: a model forVolvoxswimming
Authors: Pedley T. J. , Brumley D. R. , Goldstein R. E. 
Published: May 2016

Colonies of the green algaVolvoxare spheres that swim through the beating of pairs of flagella on their surface somatic cells. The somatic cells themselves are mounted rigidly in a polymeric extracellular matrix, fixing the orientation of the flagella so that they beat approximately in a meridional plane, with axis of symmetry in the swimming direction, but with a roughly$20^{\circ }$azimuthal offset which results in the eponymous rotation of the colonies about a body-fixed axis. Experiments on colonies ofVolvox carteriheld stationary on a micropipette show that the beating pattern takes the form of a symplectic metachronal wave (Brumley et al. Phys. Rev. Lett., vol. 109, 2012, 268102). Here we extend the Lighthill/Blake axisymmetric, Stokes-flow model of a free-swimming spherical squirmer (Lighthill Commun. Pure Appl. Maths, vol. 5, 1952, pp. 109–118; Blake J. Fluid Mech., vol. 46, 1971b, pp. 199–208) to include azimuthal swirl. The measured kinematics of the metachronal wave for 60 different colonies are used to calculate the coefficients in the eigenfunction expansions and hence predict the mean swimming speeds and rotation rates, proportional to the square of the beating amplitude, as functions of colony radius. As a test of the squirmer model, the results are compared with measurements (Drescher et al. Phys. Rev. Lett., vol. 102, 2009, 168101) of the mean swimming speeds and angular velocities of a different set of 220 colonies, also given as functions of colony radius. The predicted variation with radius is qualitatively correct, but the model underestimates both the mean swimming speed and the mean angular velocity unless the amplitude of the flagellar beat is taken to be larger than previously thought. The reasons for this discrepancy are discussed.
A century of geometry and velocity evolution at Eqip Sermia, West Greenland
Authors: LÜTHI MARTIN P. , VIELI ANDREAS , MOREAU LUC , JOUGHIN IAN , REISSER MORITZ , SMALL DAVID , STOBER MANFRED 
Published: May 2016

ABSTRACTRapid dynamic changes of ocean-terminating outlet glaciers of the Greenland ice sheet are related to atmospheric and oceanic warming but the detailed link to external forcing is not well understood. Observations show high variability in dynamic changes and are mainly limited to the past three decades with dense satellite observations. Here we compile a long-term record of dynamic changes of Eqip Sermia Glacier, West Greenland. Starting in 1912, we combine historical measurements of terminus positions, ice-surface elevation and flow velocity together with more recent in-situ and remote-sensing observations. In the 20th century, the glacier underwent small variations in terminus position and flow speed. Between 2000 and 2003, the terminus retreated substantially, but stabilized thereafter. In 2009, the northern terminus lobe started to retreat very rapidly; the southern lobe collapsed in 2013. The present terminus position, which has retreated by 4 km since 1920, is unprecedented in the historical record. Flow velocities were relatively stable until 2010. The recent acceleration reached threefold velocities in 2014 and rapidly affected the whole terminus region up to 15 km inland. Comparison with forcings from the atmosphere and the ocean over the past century shows that no dominant cause can be identified, and that local effects of bed geometry modulate the glacier response.
LOCAL KNOWLEDGE OF TREE ATTRIBUTES UNDERPINS SPECIES SELECTION ON COFFEE FARMS
Authors: LAMOND GENEVIEVE , SANDBROOK LINDSEY , GASSNER ANJA , SINCLAIR FERGUS L. 
Published: May 2016

SUMMARYThe extent to which coffee agroforestry systems provide ecosystem services depends on local context and management practices. There is a paucity of information about how and why farmers manage their coffee farms in the way that they do and the local knowledge that underpins this. The present research documents local agro-ecological knowledge from a coffee growing region within the vicinity of the Aberdare Forest Reserve in Central Kenya. Knowledge was acquired from over 60 coffee farmers in a purposive sample, using a knowledge-based systems approach, and tested with a stratified random sample of 125 farmers using an attribute ranking survey. Farmers had varying degrees of explanatory knowledge about how trees affected provisioning and regulating ecosystem services. Trees were described as suitable or unsuitable for growing with coffee according to tree attributes such as crown density and spread, root depth and spread, growth rate and their economic benefit. Farmers were concerned that too high a level of shade and competition for water and nutrients would decrease coffee yields, but they were also interested in diversifying production from their coffee farms to include fruits, timber, firewood and other tree products as a response to fluctuating coffee prices. A range of trees were maintained in coffee plots and along their boundaries but most were at very low abundances. Promoting tree diversity rather than focussing on one or two high value exotic species represents a change of approach for extension systems, the coffee industry and farmers alike, but is important if the coffee dominated landscapes of the region are to retain their tree species richness and the resilience this confers.
LOADING THE DICE IN FAVOUR OF THE FARMER: REDUCING THE RISK OF ADOPTING AGRONOMIC INNOVATIONS
Authors: COE RIC , NJOLOMA JOYCE , SINCLAIR FERGUS 
Published: May 2016

SUMMARYAgricultural development projects frequently promote new crop production technologies for adoption at scale on the basis of research and pilot studies in a limited number of contexts. The performance of these production technologies is often variable and dependent on context. Using an example from the Agroforestry for Food Security Project in Malawi, that promoted agroforestry technologies for soil fertility enhancement, we explore the nature and implications of variation in performance across farmers. Mean effects of these technologies, measured by differences in maize yield between agroforestry and sole maize plots, were modest but positive. However, there was large variation in those differences, some explained by altitude, plot management and fertilizer use but with much unexplained. This represents risk to farmers. Those communicating with farmers need to be honest and clear about this risk. It can be reduced by explanation in terms of contextual factors. This should be an aim of research that can often be embedded in scaling up the promotion of agronomic innovations.
The history, status and trends of the Endangered Seychelles Magpie-robinCopsychus sechellarum
Authors: BURT APRIL J. , GANE JULIE , OLIVIER IAIN , CALABRESE LICIA , DE GROENE ARJAN , LIEBRICK TANYA , MARX DANE , SHAH NIRMAL 
Published: May 2016

SummaryThe once ‘Critically Endangered’ Seychelles Magpie-robin was down to just 12 individuals in 1960 on one island of the granitic Seychelles. In 2015, due to intensive long-term management the population stands at around 280 birds on five islands, marking a significant success for this species. Translocations to the islands of Cousin and Cousine have led to population saturation and stability, a translocation to Denis Island has resulted in a continuing population increase and the founder population on Frégate Island is likewise increasing. The latest translocation to Aride Island in 2002 resulted in population increase then stability but is now showing a steep decline throughout 2014 into 2015. Reasons for this decline are yet unknown though disease, lack of recruitment, the impacts of social conflict and the possibility of genetic issues are discussed. This report summarises the history of management for this species, compiling all available published and unpublished information, to provide a comprehensive account of the Seychelles Magpie-robin recovery.
Adaptation to climate change: how does heterogeneity in adaptation costs affect climate coalitions?
Authors: Lazkano Itziar , Marrouch Walid , Nkuiya Bruno 
Published: May 2016

AbstractAdaptation costs to climate change vary widely across countries, especially between developed and developing countries. Adaptation costs also influence a country's decision to abate and join international environmental agreements (IEAs). In this paper, the authors study how these cost differences affect participation incentives. Their model identifies two channels through which adaptation affects free-riding incentives: carbon leakage and cost asymmetry in adaptation. In contrast with the common view, the authors find that the presence of adaptation is not necessarily an impediment to cooperation on abatement. They also present conditions under which adaptation can strengthen or weaken free-riding incentives. The results serve as a cautionary tale to policy makers and suggest that policies directed at reducing carbon leakage and/or cost differences between developed and developing countries may also affect the success and failure of IEAs.
Technical-economical aspects of the Alcarreña sheep farms in Spain and characterization of their meat products
Authors: Palacios C. , Revilla I. , Lurueña-Martínez M.A. , Álvarez S. , Abecia J.A. 
Published: May 2016

SummaryAlcarreña is an endangered Spanish sheep breed (8 009 breeding animals) characterized by its adaptation to a particularly harsh environment and by having a sustainable pasture-based, small-scale, production model. The first objective of this study was to identify the technical-economic aspects of the Alcarreña farms, based on information obtained from surveys. The second objective was to quantify the influence of slaughter weight (12, 19 and 23 kg) on the sensory characteristics of the lamb meat. The mean age of the Alcarreña sheep farmers was lower than the average age of Spanish sheep farmers; however, generational renewal is not assured because most of the farmers’ children were still in school. Mean flock size was higher than the average Spanish sheep flock. Alcarreña sheep were reared under an extensive management system, grazed year-round and had a reproductive schedule of three lambings within 2 years. The carcass and meat qualities of the 12 and 19 kg lambs did not differ significantly, although the lightest lambs had the softest meat and the clearest subcutaneous fat. The most important differences between the lighter lambs and the 23-kg lambs were in meat and fat colour and lipid composition. Among the sensorial characteristics, the 19-kg lambs had the lowest meat fibrosity, and meat colour and slaughter weight were negatively correlated.
Mining 3D genome structure populations identifies major factors governing the stability of regulatory communities
Authors: Dai Chao , Li Wenyuan , Tjong Harianto , Hao Shengli , Zhou Yonggang , Li Qingjiao , Chen Lin , Zhu Bing , Alber Frank , Jasmine Zhou Xianghong 
Published: May 2016

AbstractThree-dimensional (3D) genome structures vary from cell to cell even in an isogenic sample. Unlike protein structures, genome structures are highly plastic, posing a significant challenge for structure-function mapping. Here we report an approach to comprehensively identify 3D chromatin clusters that each occurs frequently across a population of genome structures, either deconvoluted from ensemble-averaged Hi-C data or from a collection of single-cell Hi-C data. Applying our method to a population of genome structures (at the macrodomain resolution) of lymphoblastoid cells, we identify an atlas of stable inter-chromosomal chromatin clusters. A large number of these clusters are enriched in binding of specific regulatory factors and are therefore defined as ‘Regulatory Communities.’ We reveal two major factors, centromere clustering and transcription factor binding, which significantly stabilize such communities. Finally, we show that the regulatory communities differ substantially from cell to cell, indicating that expression variability could be impacted by genome structures.