bluuebunny/crossref_metadata_2025_split huggingface dataset:
Separation of catechins and methylxanthines in tea samples by capillary electrochromatography
Authors: Dilek Uysal Ulku , Aturki Zeineb , Raggi Maria Augusta , Fanali Salvatore 
Published: March 2009

AbstractIn this paper, the simultaneous separation of several polyphenols such as (+)‐catechin, (–)‐epicatechin, (–)‐epigallocatechin, theophylline, caffeine in green and black teas by capillary electrochromatography (CEC) was developed. Several experimental parameters such as stationary phase type, mobile phase composition, buffer and pH, inner diameter of the columns, sample injection, were evaluated to obtain the complete separation of the analysed compounds. Baseline resolution of the studied polyphenols was achieved within 30 min by using a capillary column (id 100 μm) packed with bidentate C18 particles for 24.5 cm and a mobile phase composed of 5 mM ammonium acetate buffer pH 4 with H2O/ACN (80:20, v/v). The applied voltage and the temperature were set at 30 kV and 20°C. Precision, detection and quantification limits, linearity, and accuracy were investigated. A good linearity (R2 > 0.9992) was achieved over a concentration working range of 2–100 μg/mL for all the analytes. LOD and LOQ were 1 and 2 μg/mL, respectively, for all studied compounds. The CEC method was applied to the analysis of those polyphenols in green and black tea samples after an extraction procedure. Good recovery data from accuracy studies ranged between 90% and 112% for all analytes.
The digraphs and inclusion intervals of matrix singular values
Authors: Tian Gui‐Xian , Huang Ting‐Zhu , Cui Shu‐Yu 
Published: March 2009

AbstractThe paper investigates the inclusion intervals of matrix singular values. By employing the digraph of a matrix, some new inclusion intervals of matrix singular values are presented. These intervals are based mainly on the use of positive scale vectors and their intersections. Theoretic analysis and numerical examples show that these results improve and generalize some known results of Li et al. (Numer. Linear Algebra Appl. 2007; 14(2):115–128) and Kolotilina (J. Math. Sci. 2006; 137(3):4794–4800). Copyright © 2009 John Wiley & Sons, Ltd.
Backward perturbation analysis for scaled total least‐squares problems
Authors: Chang X.‐W. , Titley‐Peloquin D. 
Published: March 2009

AbstractThe scaled total least‐squares (STLS) method unifies the ordinary least‐squares (OLS), the total least‐squares (TLS), and the data least‐squares (DLS) methods. In this paper we perform a backward perturbation analysis of the STLS problem. This also unifies the backward perturbation analyses of the OLS, TLS and DLS problems. We derive an expression for an extended minimal backward error of the STLS problem. This is an asymptotically tight lower bound on the true minimal backward error. If the given approximate solution is close enough to the true STLS solution (as is the goal in practice), then the extended minimal backward error is in fact the minimal backward error. Since the extended minimal backward error is expensive to compute directly, we present a lower bound on it as well as an asymptotic estimate for it, both of which can be computed or estimated more efficiently. Our numerical examples suggest that the lower bound gives good order of magnitude approximations, while the asymptotic estimate is an excellent estimate. We show how to use our results to easily obtain the corresponding results for the OLS and DLS problems in the literature. Copyright © 2009 John Wiley & Sons, Ltd.
An asymptotic approach to analysis of 3D beam stress‐strain elastic states
Authors: Saurin Vasily , Kostin Georgy 
Published: March 2009

AbstractA regular asymptotic approach to analysis of 3D beam stress–strain states is proposed based on the linear theory of elasticity and the method of integrodifferential relations. Using the integral formulation of Hooke's law and polynomial expansions of unknown stress and displacement functions with respect to transversal Cartesian coordinates the initial system of partial differential equations is reduced to a countable system of ordinary differential equations with constant coefficients. For rectilinear beams with rectangular cross–sections the consistent boundary value problems describing independently the compression and stretch, bends, and torsion states are derived. To find equilibrium stress and admissible displacement fields satisfying boundary conditions an effective numerical algorithm is worked out. Integral and local criteria for explicit bilateral estimates of resulted solution quality are proposed. The numerical results are presented and discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Founder Fukutin mutation causes Walker–Warburg syndrome in four Ashkenazi Jewish families
Authors: Chung Wendy , Winder Thomas L. , LeDuc Charles A. , Simpson Lynn L. , Millar William S. , Dungan Jeffrey , Ginsberg Norman , Plaga Stacey , Moore Steven A. , Chung Wendy K. 
Published: March 2009

AbstractObjectiveWalker‐Warburg syndrome (WWS) is a genetically heterogeneous congenital muscular dystrophy caused by abnormal glycosylation of α‐dystroglycan (α‐DG) that is associated with brain malformations and eye anomalies. The Fukutin (FKTN) gene, which causes autosomal recessively inherited WWS is most often associated with Fukuyama congenital muscular dystrophy in Japan. We describe the clinical features of four nonconsanguinous Ashkenazi Jewish families with WWS and identify the underlying genetic basis for WWS.MethodWe screened for mutations in POMGnT1, POMT1, POMT2, and FKTN, genes causing WWS, by dideoxy sequence analysis.ResultsWe identified an identical homozygous c.1167insA mutation in the FKTN gene on a common haplotype in all four families and identified 2/299 (0.7%) carriers for the c.1167insA mutation among normal American Ashkenazi Jewish adults.ConclusionThese data suggest that the c.1167insA FKTN mutation described by us is a founder mutation that can be used to target diagnostic testing and carrier screening in the Ashkenazi Jewish population. Copyright © 2009 John Wiley & Sons, Ltd.
Natural metabolites for parasitic weed management
Authors: Vurro Maurizio , Boari Angela , Evidente Antonio , Andolfi Anna , Zermane Nadjia 
Published: March 2009

AbstractCompounds of natural origin, such as phytotoxins produced by fungi or natural amino acids, could be used in parasitic weed management strategies by interfering with the early growth stages of the parasites. These metabolites could inhibit seed germination or germ tube elongation, so preventing attachment to the host plant, or, conversely, stimulate seed germination in the absence of the host, contributing to a reduction in the parasite seed bank. Some of the fungal metabolites assayed were very active even at very low concentrations, such as some macrocyclic trichothecenes, which at 0.1 µM strongly suppressed the germination of Orobanche ramosa L. seeds. Interesting results were also obtained with some novel toxins, such as phyllostictine A, highly active in reducing germ tube elongation and seed germination both of O. ramosa and of Cuscuta campestris Yuncker. Among the amino acids tested, methionine and arginine were particularly interesting, as they were able to suppress seed germination at concentrations lower than 1 mM. Some of the fungal metabolites tested were also able to stimulate the germination of O. ramosa seeds. The major findings in this research field are described and discussed. Copyright © 2009 Society of Chemical Industry
Four‐wave mixing from individual excitons: Intensity dependence and imaging
Authors: Kasprzak Jacek , Langbein Wolfgang 
Published: March 2009

AbstractWe use heterodyne spectral interferometry (HSI) to investigate the transient four‐wave mixing field (FWM) from an individual localized excitonic transition. FWM intensity and spectrum as well as the spatial resolution in FWM hyperspectral imaging are measured as function of excitation intensity. A third‐order non‐linear response of the FWM followed by saturation and the onset of a Rabi‐flop are observed with increasing intensity. The intensity dependence of the spectral response depends on the excitation pulse duration. For short pulses (∼0.2 ps), having a broad spectrum, a weak broadening of the emission line, similar to excitation induced dephasing (EID), is found. For long pulses (∼0.5 ps) instead, no signatures of EID are found, but individual multi‐excitonic transitions are observed. When using the FWM intensity as image contrast by spatially scanning a region of the sample surface, a spatial resolution beyond the diffraction limit is measured in the third‐order regime, while for higher intensities the FWM saturation deteriorates the spatial resolution. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Brief report: Citizenship concepts among adolescents. Evidence from a survey among Belgian 16‐year olds
Authors: Dejaeghere Yves , Hooghe Marc 
Published: March 2009

AbstractIn this research note we investigate the occurrence of citizenship concepts among adolescents in Belgium. The analysis is based on the Belgian Youth Survey (2006), which is a representative survey among 6330 16‐year olds in the country. Citizenship concepts were shown to be multi‐dimensional, with distinct factors for conventional or electoral participation and civic engagement. A third, weaker factor could be distinguished covering obedience to the law. This structure is largely in line with earlier comparative analysis. An exploratory analysis suggests that these factors have different outcomes on actual or intended political participation behavior of adolescents. We discuss the relevance of these findings with regard to the current debates on civic education and civic engagement among younger age cohorts.
Gamma irradiation alters the phenotype and function of CD4+CD25+ regulatory T cells
Authors: Cao Mengde , Cabrera Roniel , Xu Yiling , Liu Chen , Nelson David 
Published: March 2009

AbstractTo examine the effects of gamma irradiation on Tregs, changes in phenotype and suppression function in Tregs treated with or without gamma ray were analyzed. Purified CD4+CD25+ regulatory T cells were irradiated at different dosages with a 137Cs source gamma ray at 4.8 Gy/min. After culture, the phenotype and function changes were determined by flow cytometry and [3H]‐thymidine incorporation, respectively. A dose‐dependent reduction of Tregs proliferation in response to gamma irradiation was noted, which paralleled the apoptosis induction of Tregs. Gamma irradiation downregulated the Tregs expression of CD45RO, CD62L, FOXP3, membrane TGF‐β, but upregulated Bax and GITR. High dose gamma irradiation (30 Gy) significantly abolished the suppression of Tregs on CD4+CD25− T cells proliferation. Thus Tregs not only influences the phenotype but also alters their suppressive capacities. Our findings suggest that radiotherapy may be an important strategy to alter the immunologic balance of Tregs and effector cells in cancer therapy.
Civil society and the reconstitution of democracy in Europe: Introducing a new research field
Authors: Liebert Ulrike , Trenz Hans-Jörg 
Published: March 2009

Abstract
The article maps new developments in the interdisciplinary research field of European civil society. From the angle of the reconstitution of democracy in the EU, it reviews recent contributions from political science, sociology and law. All share the concern with the pervading empowerment of the institutions of European multi-level governance. But each approaches the question of the democratizing and legitimizing potential of civil society beyond the state from a different vantage point, indicating competing conceptions of European civil society that draw on deliberative, participatory or representative democratic norms. It is argued that the EU-constitutional experience has sharpened the ambivalence between top down activating or “partnership” approaches vs. bottom up mobilizing or “social constituency” approaches to the construction of European civil society. These new tensions in the concept of a European civil society are currently manifested in the upholding of its civic-cosmopolitan promises and a more nuanced view of its contentious role against uncivil practices.
AGRONOMIC AND FINANCIAL BENEFITS OF PHOSPHORUS AND NITROGEN SOURCES IN WESTERN KENYA
Authors: JAMA BASHIR , KIWIA ABEDNEGO 
Published: March 2009

SUMMARYA better understanding of the agronomic and economic benefits of integrating organic and inorganic fertilizers is essential for their wide-scale dissemination and adoption in smallholder farming systems in developing countries. Field studies were conducted for 10 cropping seasons (1996–2000) on a Kandiudalfic Eutrudox soil to compare the effects of Minjingu phosphate rock (MPR) and triple superphosphate (TSP) on the yield of maize (Zea mays), in combination with three nitrogen (N) sources: urea, Tithonia diversifolia and Sesbania sesban leafy biomass. Urea and tithonia were applied to provide 60 kg N ha−1. Phosphorus (P) from either MPR or TSP was added either once at 250 kg P ha−1 at the beginning of the experiment or annually at 50 kg P ha−1 for five years, the two rates representing two P recapitalization strategies. From the second year, potassium (K) was added to half of each plot to correct for the deficiency that emerged. Over the 10 cropping seasons, the agronomic and economic benefits of the two P recapitalization strategies were similar and were not influenced by the P sources used. With N and K application, both P sources resulted in at least a two-fold maize grain yield increase over the control with no P application that averaged 1.1 tons ha−1. Comparing the N sources, although urea and tithonia had similar net benefits when P was applied, the total cost associated with tithonia was considerably higher. Without P application, sesbania fallow was the most financially attractive option. Sesbania fallows as an N source were also least sensitive to increases in the price of fertilizers and the cost of labour although the financial benefits of this system remained low in the absence of P and K application.
Couples' provision of informal care for parents and parents-in-law: far from sharing equally?
Authors: HENZ URSULA 
Published: March 2009

ABSTRACTThis study examines whether and how couples share the provision of informal care for their parents. Four waves of the British General Household Survey contain cross-sectional information about caring for parents and parents-in-law. Descriptive and multivariate analyses were conducted on 2214 couples that provided parent care. The findings emphasise married men's contribution to informal caring for the parental generation and at the same time demonstrate the limits of their involvement. Spouses share many parts of their care-giving but this arrangement is less common with respect to personal and physical care. The more care is required the more likely are people to participate in care for their parents-in-law. More sons-in-law than daughters-in-law provide care but, once involved, daughters-in-law provide on average more hours of care than sons-in-law. Own full-time employment reduces both men's and women's caring for their parents-in-law, and men's caring drops further if their wife is not in the labour market. The findings suggest that daughters-in-law often take direct responsibility whereas sons-in-laws' care-giving depends more on their wives' involvement. Children-in-laws' informal care-giving might decrease in the future because of women's increasing involvement in the labour market and rising levels of non-marital cohabitation in mid-life.
Psychosocial wellbeing and reasons for retirement in Sweden
Authors: NORDENMARK MIKAEL , STATTIN MIKAEL 
Published: March 2009

ABSTRACTGiven the increased heterogeneity of the transition from work to retirement, this study aimed to analyse the associations between different reasons for retirement and psychosocial wellbeing as a pensioner. The study used data from the SwedishPanel Survey of Ageing and the Elderly(PSAE), a nationally representative survey of the living conditions of older people in Sweden. The results show that almost one-half of all pensioners cited health problems as a contributory reason for ceasing work. Furthermore, those who retired for ‘push’ reasons, such as health problems or labour market factors, experienced lower psychosocial wellbeing than those who retired for other reasons. Moreover, the results show that those who were able to influence the time of their retirement enjoyed better psychosocial wellbeing than those who had little or no opportunity to do so. This was true when controlling for other factors relevant to the wellbeing of pensioners. The results lend support to the argument that, if a man's retirement is instigated because his skills are no longer required, there will be a decidedly negative effect on his wellbeing – and that this effect is stronger than the equivalent impact on a woman's wellbeing. In relation to previous findings in this field, the results make it clear that retirement is far from a uniform process or state.
Spatially resolved dynamics of high-z star forming galaxies
Authors: Genzel Reinhard 
Published: March 2009

AbstractI report on two major programs to study the kinematic properties of galaxies at z ~ 1.5 − 3 with spatially resolved spectroscopy for the first time. Using the adaptive optics assisted, integral field spectrometer SINFONI on the ESO VLT, we have observed more than 70 galaxies and find compelling evidence for large, geometrically thick (turbulent), rotating disk galaxies in a majority of the objects that we can spatially resolve. It appears that these star forming disks are driven by continuous, rapid accretion of gas from their dark matter halos, and that their evolution is strongly influenced by internal, secular evolution. In contrast to the 20 submillimeter galaxies that we have investigated with the IRAM Plateau de Bure millimetre interferometer we find strong evidence for compact, major mergers. I discuss the impact of these new observations on our understanding of galaxy evolution in the early Universe.For the SINS survey we have carried out Hα integral field spectroscopy of well-resolved, UV/optically selected star-forming galaxies at z ~ 2 with SINFONI on the ESO VLT. The SINS sample is representative of the majority of massive (M* > a few 1010M⊙) star-forming galaxies at that redshift. Our data obtained with laser guide star assisted adaptive optics in good seeing show the presence of turbulent, rotating star-forming rings/disks in at least a third of the sample, plus central bulge/inner disk components in some of the best cases, whose mass fractions relative to total dynamical mass appears to scale with [NII]/Hα flux ratio and ‘star formation’ age. Another third of the SINS galaxies show clear signs of kinematic perturbations by a merger, while the last third appear to be compact, ‘dispersion’ limited systems.Our interpretation of these data is that the buildup of the central disks and bulges of massive galaxies at z ~ 2 can be driven by the early secular evolution of gas-rich ‘proto’-disks. High-redshift disks exhibit large random motions. This turbulence may in part be stirred up by the release of gravitational energy in the rapid ‘cold’ accretion flows along the filaments of the cosmic web. As a result, dynamical friction and viscous processes proceed on a time scale of < 1 Gyr, at least an order of magnitude faster than in disk galaxies at z ~ 0. Early secular evolution thus drives gas and stars into the central regions and can build up exponential disks and massive bulges, even without major mergers. Secular evolution along with increased efficiency of star formation at high surface densities may also help to account for the short time scales of the stellar buildup observed in massive galaxies at z ~ 2.
Simulating High-Redshift Disk Galaxies: Applications to Long Duration Gamma-Ray Burst Hosts
Authors: Robertson Brant E. 
Published: March 2009

AbstractThe efficiency of star formation governs many observable properties of the cosmological galaxy population, yet many current models of galaxy formation largely ignore the important physics of star formation and the interstellar medium (ISM). Using hydrodynamical simulations of disk galaxies that include a treatment of the molecular ISM and star formation in molecular clouds (Robertson & Kravtsov 2008), we study the influence of star formation efficiency and molecular hydrogen abundance on the properties of high-redshift galaxy populations. In this work, we focus on a model of low-mass, star forming galaxies at 1 ≲ z ≲ 2 that may host long duration gamma-ray bursts (GRBs). Observations of GRB hosts have revealed a population of faint systems with star formation properties that often differ from Lyman-break galaxies (LBGs) and more luminous high-redshift field galaxies. Observed GRB sightlines are deficient in molecular hydrogen, but it is unclear to what degree this deficiency owes to intrinsic properties of the galaxy or the impact the GRB has on its environment. We find that hydrodynamical simulations of low-stellar mass systems at high-redshifts can reproduce the observed star formation rates and efficiencies of GRB host galaxies at redshifts 1 ≲ z ≲ 2. We show that the compact structure of low-mass high-redshift GRB hosts may lead to a molecular ISM fraction of a few tenths, well above that observed in individual GRB sightlines. However, the star formation rates of observed GRB host galaxies imply molecular gas masses of 108 – 109M⊙ similar to those produced in the simulations, and may therefore imply fairly large average H2 fractions in their ISM.
The mass content of the Sculptor dwarf spheroidal galaxy
Authors: Battaglia G. , Helmi A. , Tolstoy E. , Irwin M. 
Published: March 2009

AbstractWe present a new determination of the mass content of the Sculptor dwarf spheroidal galaxy, based on a novel approach which takes into account the two distinct stellar populations present in this galaxy. This method helps to partially break the well-known mass-anisotropy degeneracy present in the modelling of pressure-supported stellar systems.
An 84-μG Magnetic Field in a Galaxy at Z=0.692?
Authors: Wolfe Arthur M. , Jorgenson Regina A. , Robishaw Timothy , Heiles Carl , Prochaska Jason X. 
Published: March 2009

AbstractThe magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of stars (Beck 2005). The field associated with ionized interstellar gas has been determined through observations of pulsars in our Galaxy. Radio-frequency measurements of pulse dispersion and the rotation of the plane of linear polarization, i.e., Faraday rotation, yield an average value B ≈ 3 μG (Han et al. 2006). The possible detection of Faraday rotation of linearly polarized photons emitted by high-redshift quasars (Kronberg et al. 2008) suggests similar magnetic fields are present in foreground galaxies with redshifts z > 1. As Faraday rotation alone, however, determines neither the magnitude nor the redshift of the magnetic field, the strength of galactic magnetic fields at redshifts z > 0 remains uncertain.Here we report a measurement of a magnetic field of B ≈ 84 μG in a galaxy at z =0.692, using the same Zeeman-splitting technique that revealed an average value of B = 6 μG in the neutral interstellar gas of our Galaxy (Heiles et al. 2004). This is unexpected, as the leading theory of magnetic field generation, the mean-field dynamo model, predicts large-scale magnetic fields to be weaker in the past, rather than stronger (Parker 1970).The full text of this paper was published in Nature (Wolfe et al. 2008).