bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison between self‐report of cannabis use and toxicological detection of THC/THCCOOH in blood and THC in oral fluid in drivers in a roadside survey
Authors: der Linden Trudy Van , Silverans Peter , Verstraete Alain G. 
Published: August 2013

The objective of this study was to compare the number of drivers who self‐reported cannabis use by questionnaires to the results of toxicological analysis.During roadside surveys, 2957 respondents driving a personal car or van completed a questionnaire to report their use of drugs and medicines during the previous two weeks and to indicate the time of their last intake. Cannabis was analyzed in oral fluid by ultra performance liquid chromatography‐tandem mass spectrometry (UPLC‐MS/MS), in blood by gas chromatography–mass spectrometry (GC‐MS).Frequencies in the time categories were calculated and compared with toxicological results. Diagnostic values were calculated for the time categories in which positive findings were to be expected (<4 h and <2 4h, respectively for tetrahydrocannabinol (THC) and delta9‐tetrahydrocannabinol (THCCOOH) in blood, <12 h for THC in oral fluid).Most self‐reported cannabis use was more than 12 h before driving. The sensitivity of the questionnaire was low, while the specificity and accuracy were high. Kappa statistics revealed a fair agreement between self‐report and positive findings for THC in oral fluid and blood and moderate agreement with THCCOOH in blood.Self‐report largely underestimates driving under the influence of cannabis, particularly recent cannabis use; therefore analysis of biological samples is necessary. Copyright © 2013 John Wiley & Sons, Ltd.
Did southern Western Ghats of peninsular India serve as refugia for its endemic biota during the Cretaceous volcanism?
Authors: Joshi Jahnavi , Karanth Praveen 
Published: August 2013

AbstractThe Western Ghats (WG) of south India, a global biodiversity hotspot, has experienced complex geological history being part of Gondwana landmass and encountered extensive volcanic activity at the end of Cretaceous epoch. It also has a climatically and topographically heterogeneous landscape. Thus, the WG offer a unique setting to explore the influence of ecological and geological processes on the current diversity and distribution of its biota. To this end, three explicit biogeographical scenarios were hypothesized to evaluate the distribution and diversification of wet evergreen species of the WG – (1) southern WG was a refuge for the wet evergreen species during the Cretaceous volcanism, (2) phylogenetic breaks in the species phylogeny would correspond to geographic breaks (i.e., the Palghat gap) in the WG, and (3) species from each of the biogeographic subdivisions within the WG would form distinct clades. These hypotheses were tested on the centipede genus Digitipes from the WG which is known to be an ancient, endemic, and monophyletic group. The Digitipes molecular phylogeny was subjected to divergence date estimation using Bayesian approach, and ancestral areas were reconstructed using parsimony approach for each node in the phylogeny. Ancestral‐area reconstruction suggested 13 independent dispersal events to explain the current distribution of the Digitipes species in the WG. Among these 13 dispersals, two dispersal events were at higher level in the Digitipes phylogeny and were from the southern WG to the central and northern WG independently in the Early Paleocene, after the Cretaceous Volcanism. The remaining 11 dispersal events explained the species’ range expansions of which nine dispersals were from the southern WG to other biogeographic subdivisions in the Eocene‐Miocene in the post‐volcanic periods where species‐level diversifications occurred. Taken together, these results suggest that southern WG might have served as a refuge for Digitipes species during Cretaceous volcanism.
Age‐specific responses to spring temperature in a migratory songbird: older females attempt more broods in warmer springs
Authors: Bulluck L. , Huber S. , Viverette C. , Blem C. 
Published: August 2013

AbstractIncreasing global temperature has led to an interest in plasticity in the timing of annual events; however, little is known about the demographic consequences of changing phenology. Annual reproductive success varies significantly among individuals within a population, and some of that variation has to do with the number of broods attempted by reproducing adults. In birds, female age and the timing of reproduction are often predictors of multiple breeding. We hypothesize that double brooding rates may be affected by spring temperature and that the response may vary with female age. We used a long‐term reproductive data set for a migratory songbird, the prothonotary warbler (Protonotaria citrea) to assess which factors influence (a) an individual female's probability of double brooding and (b) the annual variation in population‐level double brooding rates. We found that older and earlier nesting birds are more likely to double brood, and that there is no evidence for senescence with regard to this trait such that the oldest females were most likely to double brood. Previous experience with double brooding (i.e., whether the female double brooded in the previous year) significantly increased the probability of doing so again. When assessing annual variation in the double brooding rate, we found an interaction between spring temperature and the proportion of older females in the population. Specifically, older females are more likely to double brood in years with warmer springs, but this relationship was not seen for younger females. Previous studies have shown that warmer temperatures lead to earlier and narrower peaks in resources and we hypothesize that these peaks are more available to older and earlier arriving females, enabling them to successfully raise more than one brood in a season. Understanding how different age classes respond to changing environmental conditions will be imperative to managing declining species.
A literature survey of low‐rank tensor approximation techniques
Authors: Grasedyck Lars , Kressner Daniel , Tobler Christine 
Published: August 2013

AbstractDuring the last years, low‐rank tensor approximation has been established as a new tool in scientific computing to address large‐scale linear and multilinear algebra problems, which would be intractable by classical techniques. This survey attempts to give a literature overview of current developments in this area, with an emphasis on function‐related tensors. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A nonstationary extreme value distribution for analysing the cessation of karst spring discharge
Authors: Liu Yan , Hao Yonghong , Fan Yonghui , Wang Tongke , Huo Xueli , Liu Youcun , Yeh Tian‐Chyi J. 
Published: August 2013

AbstractThe effects of climate change and population growth in recent decades are leading us to consider their combined and potentially extreme consequences, particularly regarding hydrological processes, which can be modeled using a generalized extreme value (GEV) distribution. Most of the GEV models were based on a stationary assumption for hydrological processes, in contrast to the nonstationary reality due to climate change and human activities. In this paper, we present the nonstationary generalized extreme value (NSGEV) distribution and use it to investigate the risk of Niangziguan Springs discharge decreasing to zero. Rather than assuming the location, scale, and shape parameters to be constant as one might do for a stationary GEV distribution analysis, the NSGEV approach can reflect the dynamic processes by defining the GEV parameters　as functions of time. Because most of the GEV model is designed to evaluate maxima (e.g. flooding, represented by positive numbers), and spring discharge cessation is a ‛minima’, we deduced an NSGEV model for minima by applying opposite numbers, i.e. negative instead of positive numbers. The results of the model application to Niangziguan Springs showed that the probability of zero discharge at Niangziguan Springs will be 1/80 in 2025, and 1/10 in 2030. After 2025, the rate of decrease in spring discharge will accelerate, and the probability that Niangziguan Springs will cease flowing will dramatically increase. The NSGEV model is a robust method for analysing karst spring discharge. Copyright © 2013 John Wiley & Sons, Ltd.
Transport characteristics and origins of carbon monoxide and ozone in Hong Kong, South China
Authors: Ding Aijun , Wang Tao , Fu Congbin 
Published: August 2013

AbstractTransport characteristics and origins of carbon monoxide (CO) and ozone (O3) transported to Hong Kong were investigated using backward Lagrangian particle dispersion modeling (LPDM) and measurement data collected at a regional background station, Hok Tsui, in South China during 2005–2007. LPDM was conducted using the Hybrid Single‐Particle Lagrangian Integrated Trajectory model (HYSPLIT) driven by Global Data Assimilation System (GDAS) data and emission inventories of CO. The LPDM simulations showed very good performance in characterizing temporal variations in CO on both seasonal and synoptic scales during the 3 years. Based on the LPDM simulations, the seasonal cycles of the source origins and transport age of CO were investigated. Carbon monoxide at the background station was found to originate mainly from the coastal regions in southern China and from eastern China, with averaged transport time of about 1 day and 2–4 days, respectively. The O3 annual maximum in autumn was influenced by regional transport of O3 precursors originating from eastern China, suggesting a strong continental outflow and its regional impacts. Photochemical processes contributed to occurrence of O3 episodes with sharp daytime O3 peaks produced from fresh subregional emissions from Hong Kong and the Pearl River Delta region, mixed with inland continental air. By examining the O3‐CO relationship and Lagrangian transport time, the roles of transport and photochemical processes in different seasons at Hok Tsui were also investigated. This study demonstrated unique applications of backward LPDM in observational data analysis as well as in understanding source‐receptor relationships and multiscale transport of CO and O3.
Eastward propagating planetary waves with periods of 1–5 days in the winter Antarctic stratosphere as revealed by MERRA and lidar
Authors: Lu Xian , Chu Xinzhao , Fuller‐Rowell Tim , Chang Loren , Fong Weichun , Yu Zhibin 
Published: August 2013

AbstractThis study presents the first report of planetary wave (PW) influences on significant temperature perturbations (10–20 K) within a course of one day detected by an Fe lidar from 35 to 51 km in the austral winter of 2011 at McMurdo (77.8°S, 166.7°E), Antarctica. Such large temperature perturbations are captured in the Modern Era Retrospective‐Analysis for Research and Applications (MERRA) data and correspond to various phases of eastward propagating PWs with periods of 1–5 days as revealed in MERRA. The strongest PW dominating the temperature perturbations has a period of 4–5 days with wavenumber −1. A 2−day wave with wavenumber −2 and a 1.25−day wave with wavenumber −3 also have significant influences. We find that these eastward propagating PWs are highly confined to winter high latitudes, likely because negative refractive indices equatorward of ~45°S result in evanescent wave characteristics and prevent the PWs from propagating to lower latitudes. The Eliassen‐Palm flux divergence and instability analyses suggest that barotropic/baroclinic instability at 50°S–60°S induced by the stratospheric polar night jet and/or the “double‐jet” structure is the most likely wave source. Such instability in the region poleward of 70°S is a complementary source for the 4−day wave, where we find that the heat flux of the 4−day wave is large and transported from ~70°S toward the pole above 40 km. This transport direction is likely linked to the meridional gradient of background temperature. The migrating diurnal tide near 78°S in the upper stratosphere is discernable, but significantly smaller than that of the dominant 4−day wave.
The role of the Sun in atmosphere–ocean coupling
Authors: Roy Indrani 
Published: August 2013

AbstractAn overview of the processes involved in determining the Sun's influence on climate is presented in the form of a flow chart. Evidence and hypotheses concerning the combined influences of the El Niño‐Southern Oscillation, the Quasi‐Biennial Oscillation and the Solar Cycle on the Hadley and Walker circulations are discussed in the context of atmosphere–ocean coupling, focussing on the Pacific region. It is shown that the Sun plays a crucial role in ocean–atmosphere coupling but that this coupling appears to be disturbed during the latter half of the 20th century, probably related to climate change. The identification of a solar influence can lead to improved skill in prediction so as to better inform communities to address/mitigate some of the crucial issues that are associated with climate change.
Estimating long‐wave radiation at the Earth's surface from measurements of specific humidity
Authors: Rosa Rafael , Stanhill Gerald 
Published: August 2013

ABSTRACTThe relationship between specific humidity (q) and down‐welling long‐wave radiation (El↓) was investigated on a daily, monthly and annual basis for 39 widely distributed sites of the Baseline Surface Radiation Network (BSRN) and validated using two additional BSRN sites. A power relationship between El↓ and q was fitted to the data for each site; the constant did not change significantly with time and geographic location. Neither the mean value of q nor the residual value of El↓ changed significantly between 1998 and 2011, suggesting the applicability of the relationship over periods without large changes in the Earth's temperature and/or concentration of H2O. The root mean square error for both the calibration and validation sites was comparable to that reported for both direct measurements and satellite‐derived estimates for daily, monthly and annual periods. The power relationships were weaker for three tropical sites located in the Pacific Ocean, where the seasonal variation in q was smaller than at the other sites. For the remaining stations, a common power relationship, El↓ = 212.64 q0.22, enabled monthly values of El↓ to be accurately estimated from widely available measurements of air temperature, humidity and pressure at the Earth's surface.
The Tourism Industry and the Process of Internationalization in the Middle East: The Example of Jordan
Authors: Pillmayer Markus , Scherle Nicolai 
Published: August 2013

SUMMARYOngoing internationalization processes have resulted in significant changes on the supply side in many fields of the economy and specifically in tourism. Although the scientific discourse is working hard to keep pace with these rapid changes, there is nevertheless a considerable deficit in research on the problems and risks as well as the potential and opportunities associated with intensifying processes of internationalization. This paper focuses on the internationalization process of small and medium‐sized tourism enterprises (SMTEs) in the Middle East, specifically in the Hashemite Kingdom of Jordan, which continues to be a tourist destination for Westerners in spite of major political and other crises. Internationalization of SMTEs is a complex process, and studies that take a more holistic view of this phenomenon are needed. This paper will therefore attempt to investigate the internationalization process in Jordan from a problem‐centred perspective and to critically examine and discuss it on the basis of comments made by leading actors in the Jordanian tourism business. The thus gained insights should help to reduce the still existing theoretical deficits in the study of the internationalization process. Particularly, the impact of the Arab Spring on the Jordanian tourism market must be included in a critical assessment. Copyright © 2013 John Wiley & Sons, Ltd.
Soil Quality Indicators Response to Land Use and Soil Management Systems in Northern Ethiopia's Catchment
Authors: Tesfahunegn Gebreyesus Brhane 
Published: August 2013

AbstractAssessment of soil quality (SQ) indicators that detect soil degradation in different land use and soil management systems (LUSMS) is desirable to achieve sustainable management strategies. The LUSMS identified for evaluation included natural forest (LS1), plantation of protected area (LS2), grazed land (LS3), teff(Eragrostis tef)‐faba bean(Vicia faba)rotation (LS4), teff‐wheat(Triticum vulgare)/barley(Hordeum vulgare)rotation (LS5), teff mono‐cropping (LS6), maize(Zea mays)mono‐cropping (LS7), and uncultivated marginal land (LS8). The SQ indicators were significantly influenced (p ≤ 0·05) by the LUSMS. The first four principal components with eigenvalue > 1 explain about 88% of the SQ variability across the LUSMS. The final principal component chosen indicators that mainly influence SQ variability were organic carbon, total nitrogen, cation exchange capacity, total phosphorus, silt, bulk density, and iron. In this study, a higher SQ was found in LS1 followed by LS2, whereas a seriously degraded SQ was observed in LS8 followed by LS6. Copyright © 2013 John Wiley & Sons, Ltd.
Effective strength of saturated double porous media with a Drucker–Prager solid phase
Authors: Shen Wanqing , He Zheng , Dormieux Luc , Kondo Djimédo 
Published: August 2013

SUMMARYThis study aims at determining the macroscopic strength of porous materials having a Drucker–Prager solid phase at microscale and two populations of saturated pores with different pressures at both micro and meso scales. To this end, and taking account of the available results by Maghous et al. (2009), we first derive a closed‐form expression of approximate criterion for a dry porous medium whose matrix obeys to a general elliptic criterion. The methodology to formulate this criterion is based on limit analysis of a hollow sphere subjected to a uniform strain rate boundary conditions. The obtained results are then implemented in a two‐step homogenization procedure, which interestingly delivers analytical expression of the macroscopic criterion for dry double porous media whose solid phase at microscale obeys to a Drucker–Prager criterion. After a brief discussion of the results, we propose an extension to double porous saturated media, allowing therefore to quantify the simultaneous effects of the different pore pressures applied on each voids population. The results are discussed in terms of the existence or not of effective stresses. Finally, they are assessed by comparing them to recently available results. Copyright © 2013 John Wiley & Sons, Ltd.
Variability of 13C‐labeling in plant leaves
Authors: Nguyen Tu Thanh Thuy , Biron Philippe , Maseyk Kadmiel , Richard Patricia , Zeller Bernd , Quénéa Katell , Alexis Marie , Bardoux Gérard , Vaury Véronique , Girardin Cyril , Pouteau Valérie , Billiou Daniel , Bariac Thierry 
Published: August 2013

RATIONALEPlant tissues artificially labeled with 13C are increasingly used in environmental studies to unravel biogeochemical and ecophysiological processes. However, the variability of 13C‐content in labeled tissues has never been carefully investigated. Hence, this study aimed at documenting the variability of 13C‐content in artificially labeled leaves.METHODSEuropean beech and Italian ryegrass were subjected to long‐term 13C‐labeling in a controlled‐environment growth chamber. The 13C‐content of the leaves obtained after several months labeling was determined by isotope ratio mass spectrometry.RESULTSThe 13C‐content of the labeled leaves exhibited inter‐ and intra‐leaf variability much higher than those naturally occurring in unlabeled plants, which do not exceed a few per mil. This variability was correlated with labeling intensity: the isotope composition of leaves varied in ranges of ca 60‰ and 90‰ for experiments that led to average leaf 13C‐content of ca +15‰ and +450‰, respectively.CONCLUSIONSThe reported variability of isotope composition in 13C‐enriched leaves is critical, and should be taken into account in subsequent experimental investigations of environmental processes using 13C‐labeled plant tissues. Copyright © 2013 John Wiley & Sons, Ltd.
Pigment Epithelium-Derived Factor Enhances Differentiation and Mineral Deposition of Human Mesenchymal Stem Cells
Authors: Li Feng , Song Na , Tombran-Tink Joyce , Niyibizi Christopher 
Published: August 2013

Abstract
Pigment epithelium-derived factor (PEDF) is a potent antiangiogenic factor found in a wide variety of tissues. Recent findings indicated that lack of PEDF leads to osteogenesis imperfecta type VI whose hallmark is a defect in mineralization. We investigated the effects of PEDF on human mesenchymal stem cells (hMSCs) and signaling pathways through which PEDF displays its activities in hMSCs. hMSCs incubated in a medium supplemented with PEDF induced expression of osteoblastic-related genes. In addition, PEDF induced alkaline phosphatase (ALP) activity in MSCs at 14 days of incubation in maintenance medium; hMSCs incubated in osteogenic medium in presence of PEDF expressed 19% more ALP activity (35.655 ± 1.827 U/mg protein, p = .041 than cells incubated in the same medium without PEDF supplementation (29.956 ± 2.100 U/μg protein). hMSCs incubated in osteogenic medium in presence of PEDF deposited 50% more mineral (2.108 ± 0.306 OD/ml per well per 1 × 104 cells per square centimeter, p = .017) than MSCs incubated in absence of the protein (1.398 ± 0.098 OD/ml per well per 1 × 104 cells per square centimeter) as determined by Alizarin Red quantitation. Reduction in PEDF expression in MSCs by siRNA led to decreased ALP activity (33.552 ± 2.009 U/ng protein of knockdown group vs. 39.269 ± 3.533 U/ng protein of scrambled siRNA group, p = .039) and significant reduction in mineral deposition (0.654 ± 0.050 OD/ml per well per 1 × 104 cells per square centimeter of knockdown group vs. 1.152 ± 0.132 OD/ml per well per 1 × 104 cells per square centimeter of wild-type group, p = .010). Decreased ALP activity and mineral deposition were restored by supplementation with exogenous PEDF protein. PEDF activated ERK and AKT signaling pathways in MSCs to induce expression of osteoblastic-related genes. These data suggest that PEDF is involved in MSCs osteoblastic differentiation. Stem Cells 2013;31:2714–2723
Unveiling the critical role of REX1 in the regulation of human stem cell pluripotency
Authors: Son Mi-Young , Choi Hoonsung , Han Yong-Mahn , Sook Cho Yee 
Published: August 2013

Abstract
Reduced expression 1 (REX1) is a widely used pluripotency marker, but little is known about its roles in pluripotency. Here, we show that REX1 is functionally important in the reacquisition and maintenance of pluripotency. REX1-depleted human pluripotent stem cells (hPSCs) lose their self-renewal capacity and full differentiation potential, especially their mesoderm lineage potential. Cyclin B1/B2 expression was found to parallel that of REX1. REX1 positively regulates the transcriptional activity of cyclin B1/B2 through binding to their promoters. REX1 induces the phosphorylation of DRP1 at Ser616 by cyclin B/CDK1, which leads to mitochondrial fission and appears to be important for meeting the high-energy demands of highly glycolytic hPSCs. During reprogramming to pluripotency by defined factors (OCT4, SOX2, KLF4, and c-MYC), the reprogramming kinetics and efficiency are markedly improved by adding REX1 or replacing KLF4 with REX1. These improvements are achieved by lowering reprogramming barriers (growth arrest and apoptosis), by enhancing mitochondrial fission, and by conversion to glycolytic metabolism, dependent on the cyclin B1/B2-DRP1 pathway. Our results show that a novel pluripotency regulator, REX1, is essential for pluripotency and reprogramming.