bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors influencing the occurrence of water stress at field scale
Authors: Orfánus Tomáš , Eitzinger Josef 
Published: November 2010

AbstractAcross a wide range of spatial and temporal scales, the soil water content (SWC) can be perceived as an integral component of the hydrological cycle. The concept of field capacity is insufficient to characterize the limits of ideal moisture conditions for plants and the concept of SWC of limited plant availability (θla) has been introduced to characterize the available SWC threshold value, below which the relative transpiration drops under 1. θla is not a stable property of soil but also depends on the actual evapotranspiration demand of the atmosphere (potential evapotranspiration, Ep). To avoid water stress and ensure high biomass production, water should be supplied to vegetation in order to maintain the optimal range of SWC above θla during important ontogenetic phases. The influence of two factors, one of which is pedological (soil texture) and another is biological (8‐m high hedgerow) on field‐scale fluctuations of θla, was studied in western Slovakia near Moravský Svätý Ján (MSJ) village and in north‐eastern Austria near the village Rutzendorf, respectively. In the MSJ‐field θla values reflected the textural heterogeneity of soil. The intrapopulation range Δθla was 0·15 m3 m−3 in a clay loam Mollic Gleysol, but only 0·08 m3 m−3 in a loamy sand Arenic Regosol. The interpopulation differences in mean θla between two textural classes were 0·06–0·09 m3 m−3. The maximum Δθla caused by changes in textural composition over the 4·5 ha field was 0·18 m3 m−3. It was found during two SWC measurement campaigns with different boundary conditions [Ep and ground water (GW) table] that the loamy sand soil is much more susceptible to the occurrence of water stress than the clay loam. The actual SWC falls below the θla threshold more frequently in loamy sand because of its small water retention capacity, rapid drainage and poorer hydraulic connection with GW. The seasonal variability of θla in 2002 reached 0·06–0·09 m3 m−3, depending on textural class. The hedgerow at Field‐Rutzendorf had a small effect on the spatial variation in θla during days with low Ep rates. Δθla was less then 0·01 m3 m−3 when potential evapotranspiration was less then 1 mm day−1. However, during days with great atmospheric demand for evapotranspiration (6 mm day−1) Δθla reached 0·19 m3 m−3 during the 2004 growing season. The results illustrate that both evapotranspiration intensity and soil texture influence the occurrence of soil water stress. Copyright © 2010 John Wiley & Sons, Ltd.
Comparison of long‐term monitoring of temperature and precipitation between wetland and other ecosystems
Authors: Kovářová Milena , Pokorný Jan 
Published: November 2010

AbstractAir temperature and precipitation changes in the decades 1961–2006 at Wet Meadows wetland ecosystem near Třeboň, South Bohemia were compared with the changes in these characteristics at other stations in the Czech Republic. Mean daily maximum air temperature measured during the vegetation growing season at wetland station Wet Meadows rose from 19·7 °C during the period 1961–1970 to 21·5 °C in the period 2001–2006 (i.e. 1·8 °C during 40 years). At Churáňov, a mountain forest station, this increase was from 14·7 to 15·8 °C (1·1 °C) and at Praha Ruzyně, a city station, the increase was from 20·0 to 20·7 °C (0·7 °C) during the same time. Mean number of precipitation days changed at Wet Meadows from 94·5 to 80·7 days per vegetation season, at Churáňov from 101·2 to 105·0 days per vegetation season and at Praha Ruzyně from 83·9 to 83·0 days per vegetation season during this time. We attribute the rise in temperature at Wet Meadows to a combined effect of climate change and a local change of the hydrological cycle. The disturbances in the short water cycle are attributed to the decrease in vegetation cover and the lack of water in the landscape. The consequent increase in the incoming direct solar radiation along with the rise in the heat coming into the area via precipitation as well as a decrease in and redistribution of precipitation events are considered major drivers of the meteorological changes that have resulted in the observed warming at Wet Meadows. Copyright © 2010 John Wiley & Sons, Ltd.
Uniform Fe3O4 Octahedra with Tunable Edge Length – Synthesis by a Facile Polyol Route and Magnetic Properties
Authors: Zhao Lijun , Duan LianFeng 
Published: November 2010

AbstractA straightforward and effective polyol route for the controllable synthesis of high‐quality magnetite (Fe3O4) octahedra with uniform edge length in ethylene glycol (EG) solution is presented. Fe3O4 octahedra with edge length in the range 70–1000 nm were selectively synthesized in high yield. The surfaces of octahedral Fe3O4 crystals correspond to (111) planes. Formation of Fe3O4 octahedra was attributed to the preferential adsorption of OH– ions onto the (111) planes of Fe3O4 nuclei, which inhibits the growth rate along the <111> direction. The release rate of Fe2+ ions in the synthesis can be rationally manipulated by varying the dose of N2H4·H2O. Control of the nucleation and growth rate by N2H4·H2O provides a facile and effective route to harvest Fe3O4 octahedra with different dimensions. The magnetic analysis shows that Fe3O4 octahedra with sharp tips possess attractive magnetic properties.
Structural and Spectroscopic Evidence of Strong Electronic Delocalization through a Cyanido Bridge in a Mixed‐Valence Os–Ru Complex
Authors: Rossi Melina B. , Abboud Khalil A. , Alborés Pablo , Baraldo Luis M. 
Published: November 2010

AbstractWe report the properties of a trinuclear cyanido‐bridged complex, trans‐(dmap)4RuII(µ‐NC)OsIII(CN)524– [14–; dmap = 4‐(dimethylamino)pyridine], whose structure and electronic and vibrational spectra present strong evidence of partial redox states for the three metal ions, an unprecedented feature for cyanido‐bridged systems.
Modeling and Spectroscopic Studies of Synthetic Diazabicyclo Analogs of the HIV‐1 Inhibitor BMS‐378806 and Evaluation of Their Antiviral Activity
Authors: Legnani Laura , Colombo Diego , Cocchi Elena , Solano Lucrezia , Villa Stefania , Lopalco Lucia , Asti Valeria , Diomede Lorenzo , Marinone Albini Franca , Toma Lucio 
Published: November 2010

AbstractThree diazabicyclo analogs of BMS‐378806, in which theaxial methyl group present on its piperazine ring is replaced by a carbon bridge, were synthesized and tested, through a viral neutralization assay, on a panel of six pseudoviruses. The diazabicyclooctane and ‐nonane derivatives maintained a significant infectivity reduction power, whereas the diazabicycloheptane derivative was much less effective. A modeling study allowed to relate the antiviral activity to the conformational preferences of the compounds. Moreover, similarly to BMS‐378806, theoretical calculations predict the existence of different conformational families corresponding to the possible arrangements at the two planar amido functions of the compounds. High‐field 1H NMR spectra confirm these results, as they show two distinct series of signals.
An Efficient Synthesis of Polysubstituted Naphthalene Derivatives by Gold‐Catalyzed Cyclization of 1‐Arylalka‐2,3‐dienyl Acetates (Eur. J. Org. Chem. 34/2010)
Authors: Kong Wangqing , Fu Chunling , Ma Shengming 
Published: November 2010

AbstractThe cover picture shows the efficient synthesis of polysubstituted naphthalene derivatives and the mechanism, which proceeds through the gold‐catalyzed cyclization of 1‐arylalka‐2,3‐dienyl acetates. The six‐membered cyclohexenyl gold species is formed from the coordination of the allene moiety to the gold followed by nucleophilic attack of the electron‐rich benzene to the metal‐activated electrophilic C=C bond. Subsequent elimination of acetic acid affords the β‐naphthyl gold intermediate, which may be trapped by iodonolysis to release the gold catalyst into the catalytic cycle and afford the target iodonaphthalene. Details are discussed in the article by S. Ma et al. on p. 6545 ff. The background picture depicts the typical scenery of West Lake in Hangzhou during the summer season where the lake is covered with lotus leaves. Zhejiang University, a university with a history of over 110 years, is located very close to West Lake.
The existence of ‘complete similarities’ in the response of seismic isolated structures subjected to pulse‐like ground motions and their implications in analysis
Authors: Makris Nicos , Vassiliou Michalis F. 
Published: November 2010

AbstractIn this paper the seismic response of isolated structures supported on bearings with bilinear and trilinear behavior is revisited with dimensional analysis in an effort to better understand the relative significance of the various parameters that control the mechanical behavior of isolation systems. An isolation system that consists of lead rubber bearings or of single concave spherical sliding bearings exhibits bilinear behavior; whereas, when a double concave configuration is used the behavior is trilinear. For the case of bilinear behavior it is well known that the value of the normalized yield displacement is immaterial to the response of the isolated superstructure—or, in mathematical terms, that the response of the bilinear oscillator exhibits complete similarity in the dimensionless yield displacement. Similarly, for the case of trilinear behavior the paper shows that the presence of the intermediate slope is immaterial to the peak response of most isolated structures—a finding that shows the response of the trilinear oscillator exhibits a complete similarity in the difference between the coefficients of friction along the two sliding surfaces as well as in the ratio of the intermediate to the final slope. This finding implies that even when the coefficients of friction of the two sliding surfaces are different, the response of isolated structures for most practical configurations can be computed with confidence by replacing the double concave spherical bearings with single concave spherical bearings with an effective radius of curvature and an effective coefficient of friction. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of irregular topography and random soil properties on coherency loss of spatial seismic ground motions
Authors: Bi Kaiming , Hao Hong 
Published: November 2010

AbstractCoherency functions are used to describe the spatial variation of seismic ground motions at multiple supports of long span structures. Many coherency function models have been proposed based on theoretical derivation or measured spatial ground motion time histories at dense seismographic arrays. Most of them are suitable for modelling spatial ground motions on flat‐lying alluvial sites. It has been found that these coherency functions are not appropriate for modelling spatial variations of ground motions at sites with irregular topography (Struct. Saf. 1991; 10(1):1–13). This paper investigates the influence of layered irregular sites and random soil properties on coherency functions of spatial ground motions on ground surface. Ground motion time histories at different locations on ground surface of the irregular site are generated based on the combined spectral representation method and one‐dimensional wave propagation theory. Random soil properties, including shear modulus, density and damping ratio of each layer, are assumed to follow normal distributions, and are modelled by the independent one‐dimensional random fields in the vertical direction. Monte‐Carlo simulations are employed to model the effect of random variations of soil properties on the simulated surface ground motion time histories. The coherency function is estimated from the simulated ground motion time histories. Numerical examples are presented to illustrate the proposed method. Numerical results show that coherency function directly relates to the spectral ratio of two local sites, and the influence of randomly varying soil properties at a canyon site on coherency functions of spatial surface ground motions cannot be neglected. Copyright © 2010 John Wiley & Sons, Ltd.
Fabrication of BaZr0.1Ce0.7Y0.2O3 – δ ‐Based Proton‐Conducting Solid Oxide Fuel Cells Co‐Fired at 1,150 °C
Authors: Sun W. , Tao Z. , Shi Z. , Yan L. , Zhu Z. , Liu W. 
Published: November 2010

AbstractDense proton‐conducting BaZr0.1Ce0.7Y0.2O3 – δ (BZCY) electrolyte membranes were successfully fabricated on NiO–BZCY anode substrates at a low temperature of 1,150 °C via a combined co‐press and co‐firing process. To fabricate full cells, the LaSr3Co1.5Fe1.5O10 – δ–BZCY composite cathode layer was fixed to the electrolyte membrane by two means of one‐step co‐firing and two‐step co‐firing, respectively. The SEM results revealed that the cathode layer bonded more closely to the electrolyte membrane via the one‐step co‐firing process. Correspondingly, determined from the electrochemical impedance spectroscopy measured under open current conditions, the electrode polarisation and Ohmic resistances of the one‐step co‐fired cell were dramatically lower than the other one for its excellent interface adhesion. With humidified hydrogen (2% H2O) as the fuel and static air as the oxidant, the maximum power density of the one‐step co‐fired single cell achieved 328 mW cm–2 at 700 °C, showing a much better performance than that of the two‐step co‐fired single cell, which was 264 mW cm–2 at 700 °C.
Distribution of model‐based multipoint heterogeneity lod scores
Authors: Xing Chao , Morris Nathan , Xing Guan 
Published: November 2010

AbstractThe distribution of two‐point heterogeneity lod scores (HLOD) has been intensively investigated because the conventional χ2 approximation to the likelihood ratio test is not directly applicable. However, there was no study investigating th	e distribution of the multipoint HLOD despite its wide application. Here we want to point out that, compared with the two‐point HLOD, the multipoint HLOD essentially tests for homogeneity given linkage and follows a relatively simple limiting distribution , which can be obtained by established statistical theory. We further examine the theoretical result by simulation studies. Genet. Epidemiol. 34: 912‐916, 2010.© 2010 Wiley‐Liss, Inc.
Meta‐analysis of sex‐specific genome‐wide association studies
Authors: Magi Reedik , Lindgren Cecilia M. , Morris Andrew P. 
Published: November 2010

AbstractDespite the success of genome‐wide association studies, much of the genetic contribution to complex human traits is still unexplained. One potential source of genetic variation that may contribute to this “missing heritability” is that which differs in magnitude and/or direction between males and females, which could result from sexual dimorphism in gene expression. Such sex‐differentiated effects are common in model organisms, and are becoming increasingly evident in human complex traits through large‐scale male‐ and female‐specific meta‐analyses. In this article, we review the methodology for meta‐analysis of sex‐specific genome‐wide association studies, and propose a sex‐differentiated test of association with quantitative or dichotomous traits, which allows for heterogeneity of allelic effects between males and females. We perform detailed simulations to compare the power of the proposed sex‐differentiated meta‐analysis with the more traditional “sex‐combined” approach, which is ambivalent to gender. The results of this study highlight only a small loss in power for the sex‐differentiated meta‐analysis when the allelic effects of the causal variant are the same in males and females. However, over a range of models of heterogeneity in allelic effects between genders, our sex‐differentiated meta‐analysis strategy offers substantial gains in power, and thus has the potential to discover novel loci contributing effects to complex human traits with existing genome‐wide association data. Genet. Epidemiol. 34:846–853, 2010. © 2010 Wiley‐Liss, Inc.
Using biological knowledge to discover higher order interactions in genetic association studies
Authors: Chen Gary K. , Thomas Duncan C 
Published: November 2010

AbstractThe recent successes of genome‐wide association studies (GWAS) have revealed that many of the replicated findings have explained only a small fraction of the heritability of common diseases. One hypothesis that investigators have suggested is that higher order interactions between SNPs or SNPs and environmental risk factors may account for some of this missing heritability. Searching for these interactions poses great statistical and computational challenges. In this article, we propose a novel method that addresses these challenges by incorporating external biological knowledge into a fully Bayesian analysis. The method is designed to be scalable for high‐dimensional search spaces (where it supports interactions of any order) because priors that use such knowledge focus the search in regions that are more biologically plausible and avoid having to enumerate all possible interactions. We provide several examples based on simulated data demonstrating how external information can enhance power, specificity, and effect estimates in comparison to conventional approaches based on maximum likelihood estimates. We also apply the method to data from a GWAS for breast cancer, revealing a set of interactions enriched for the Gene Ontology terms growth, metabolic process, and biological regulation.Genet. Epidemiol. 34:863–878, 2010. © 2010 Wiley‐Liss, Inc.
SNP Selection in genome‐wide and candidate gene studies via penalized logistic regression
Authors: Ayers Kristin L. , Cordell Heather J. 
Published: November 2010

AbstractPenalized regression methods offer an attractive alternative to single marker testing in genetic association analysis. Penalized regression methods shrink down to zero the coefficient of markers that have little apparent effect on the trait of interest, resulting in a parsimonious subset of what we hope are true pertinent predictors. Here we explore the performance of penalization in selecting SNPs as predictors in genetic association studies. The strength of the penalty can be chosen either to select a good predictive model (via methods such as computationally expensive cross validation), through maximum likelihood‐based model selection criterion (such as the BIC), or to select a model that controls for type I error, as done here. We have investigated the performance of several penalized logistic regression approaches, simulating data under a variety of disease locus effect size and linkage disequilibrium patterns. We compared several penalties, including the elastic net, ridge, Lasso, MCP and the normal‐exponential‐γ shrinkage prior implemented in thehyperlassosoftware, to standard single locus analysis and simple forward stepwise regression. We examined how markers enter the model as penalties andP‐value thresholds are varied, and report the sensitivity and specificity of each of the methods. Results show that penalized methods outperform single marker analysis, with the main difference being that penalized methods allow the simultaneous inclusion of a number of markers, and generally do not allow correlated variables to enter the model, producing a sparse model in which most of the identified explanatory markers are accounted for.Genet. Epidemiol. 34:879–891, 2010. © 2010 Wiley‐Liss, Inc.
Evaluating haplotype effects in case‐control studies via penalized‐likelihood approaches: prospective or retrospective analysis?
Authors: Koehler Megan L. , Bondell Howard D. , Tzeng Jung‐Ying 
Published: November 2010

AbstractPenalized likelihood methods have become increasingly popular in recent years for evaluating haplotype‐phenotype association in case‐control studies. Although a retrospective likelihood is dictated by the sampling scheme, these penalized methods are typically built on prospective likelihoods due to their modeling simplicity and computational feasibility. It has been well documented that for unpenalized methods, prospective analyses of case‐control data can be valid but less efficient than their retrospective counterparts when testing for association, and result in substantial bias when estimating the haplotype effects. For penalized methods, which combine effect estimation and testing in one step, the impact of using a prospective likelihood is not clear. In this work, we examine the consequences of ignoring the sampling scheme for haplotype‐based penalized likelihood methods. Our results suggest that the impact of prospective analyses depends on (1) the underlying genetic mode and (2) the genetic model adopted in the analysis. When the correct genetic model is used, the difference between the two analyses is negligible for additive and slight for dominant haplotype effects. For recessive haplotype effects, the more appropriate retrospective likelihood clearly outperforms the prospective likelihood. If an additive model is incorrectly used, as the true underlying genetic mode is unknown a priori, both retrospective and prospective penalized methods suffer from a sizeable power loss and increase in bias. The impact of using the incorrect genetic model is much bigger on retrospective analyses than prospective analyses, and results in comparable performances for both methods. An application of these methods to the Genetic Analysis Workshop 15 rheumatoid arthritis data is provided.Genet. Epidemiol. 34:892–911, 2010. © 2010 Wiley‐Liss, Inc.
The impact of job embeddedness on innovation‐related behaviors
Authors: Ng Thomas W. H. , Feldman Daniel C. 
Published: November 2010

AbstractIt has often been argued that low turnover leads to less innovation in organizations, not only because fewer job vacancies are available for outsiders with new ideas, but also because longer‐tenured employees might be more resistant to change. In this study, we propose that job embeddedness may actually strengthen employees' motivation to generate, spread, and implement innovative ideas in organizations. In a longitudinal study with a diverse sample, we found that job embeddedness was positively and significantly related to innovation‐related behaviors, even after controlling for demographic variables, the job attitudes, and the job perceptions that are frequently associated with job embeddedness. In addition, we found some support for the proposed moderating effects of career stage; that is, the relationship between job embeddedness and implementing innovative ideas was stronger for individuals in the mid‐ and late stages of their careers than for those in the early stage of their careers. This article concludes with directions for developing future theory. © 2010 Wiley Periodicals, Inc.
The human resource department's role and conditions that affect its development: Explanations from Austrian CEOs
Authors: Brandl Julia , Pohler Dionne 
Published: November 2010

AbstractUsing a qualitative approach, this study fills a void in the literature on strategic HRM by analyzing Austrian CEOs' perceptions of the role of the HR department in their organizations, and the conditions that affect the development of a strategic role. The results suggest that even if CEOs have an overall positive evaluation of their HR departments and are willing to delegate responsibility for higher‐level decision‐making, to develop the HR department's role, CEOs must also feel they have the scope to do so. A framework for future research and practical implications for opportunities and constraints confronting HR managers are discussed. © 2010 Wiley Periodicals, Inc.