bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial biomass and activity on railway track and embankments
Authors: Cederlund Harald , Stenström John 
Published: May 2004

AbstractThe spatial distribution of microbial biomass and microbial activity was studied in two Swedish railway embankments (located close to Mora and Nässjö). Basal respiration and substrate‐induced respiration (SIR) as well as the active (r) and dormant (K) fractions of the microbial biomass were determined in samples taken from the surface layer of the ballast. The SIR, r, K and basal respiration values were all of an overall low magnitude, but were highly variable over short distances on the track. Both the biomass and basal respiration were higher on the sides of the embankment than in the middle of the tracks. SIR, K and basal respiration were correlated to the organic matter content as measured by loss on ignition, whereas r was not. None of the parameters correlated with pH. It is proposed that organic matter content could be used as a predictor for microbial biomass in railway embankments. Copyright © 2004 Society of Chemical Industry
Hydrolysis and photolysis of flumioxazin in aqueous buffer solutions
Authors: Kwon Jeong‐Wook , Armbrust Kevin L , Grey Timothy L 
Published: May 2004

AbstractTo determine the degradation rates and degradation products of the herbicide flumioxazin in aqueous buffer solutions (pH 5, 7 and 9), its hydrolysis and photolysis were investigated at 30 °C in the dark, and in a growth chamber fitted with fluorescent lamps simulating the UV output of sunlight. The rate of hydrolysis of flumioxazin was accelerated by increasing pH. The t1/2 values at pH 5, 7 and 9 were 16.4, 9.1 and 0.25 h, respectively. Two degradation products were detected and their structural assignments were made on the basis of LC‐MS data. Degradation product I was detected in all buffer solutions while degradation product II was detected in acidic buffer only. Both degradation products appeared to be stable to further hydrolysis. After correcting for the effects of hydrolysis, the photolytic degradation rate also increased as a function of pH and was approximately 10 times higher at pH 7 than that at pH 5, showing t1/2 values of 4.9 and 41.5 h, respectively. Degradation products formed by photolysis were the same as those formed by hydrolysis. Flumioxazin was degraded more extensively at high pH and should degrade in surface water. Copyright © 2004 Society of Chemical Industry
Influence of dispersion length on leaching calculated with PEARL, PELMO and PRZM for FOCUS groundwater scenarios
Authors: Boesten Jos JTI 
Published: May 2004

AbstractHarmonisation of the assessment of pesticide leaching to groundwater for EU registration is desirable to minimise confusion in the decision‐making process at EU level. Recently, the FOCUS groundwater scenarios have been developed for three chromatographic models (PEARL, PELMO and PRZM) to increase this harmonisation. This study investigates the role of dispersion parameterisation in explaining the cause of the differences in pesticide leaching calculated by these models. PEARL describes dispersion via a physical parameter, ie the dispersion length. PELMO and PRZM simulate dispersion via a numerical procedure which generates an effective dispersion length equal to 0.5 times the thickness of the numerical compartments. The hypothesis was tested that the difference in the dispersion length input parameter (ie 5 cm for PEARL and about 2.5 cm for PELMO and PRZM) is a major cause of the difference in calculated leaching. It was tested whether results of PEARL calculations with a dispersion length of 2.5 cm corresponded much better to results of PELMO or PRZM than results of PEARL calculations with a dispersion length of 5 cm. This was done by calculations for one substance and all nine FOCUS scenarios and by calculations for a range of substances and two FOCUS scenarios (Châteaudun and Sevilla). All calculations were for winter wheat and an application at 1 day before emergence. Both tests showed that reduction of the dispersion length from 5 to 2.5 cm in PEARL led to a much better correspondence between PEARL and either PELMO or PRZM. Hence the hypothesis was supported. It is likely that harmonisation of the dispersion length in the FOCUS groundwater scenarios would reduce the differences in calculated leaching between PEARL and PELMO or PRZM considerably for part of these scenarios. Published in 2004 for SCI by John Wiley & Sons, Ltd.
‘Been there, done that’: international student migration and human capital transfers from the UK to Slovakia
Authors: Baláž Vladimír , Williams Allan M. 
Published: May 2004

AbstractInternational student migration remains an under‐researched field in migration studies, and this is especially true of return migration. This paper analyses students from Slovakia who have studied in the UK, both on degree courses and language/vocational courses, and have subsequently returned to their country of origin. It analyses their motivations, their acquisition of human capital in the UK, and the extent to which they have been able to realise individual welfare gains after returning to Slovakia. Their evaluations of their experiences are highly positive, with substantial numbers also reporting improvements in their jobs and incomes, even following relatively short stays abroad. The study emphasises the importance of the specific competences acquired by the students, rather than broad skill categories, or qualifications. It highlights the value attached to language competence, in particular, but also to learning, attitudinal and interpersonal competences, as well as networking. The paper concludes that there is a need to pay more attention to individual social biographies when understanding the relationship between migration and learning. At the same time, it also stresses structural parameters to individual agency, including the specific economic conditions in a transition economy, and the market value of competence in English as a world language. Copyright © 2004 John Wiley & Sons, Ltd.
‘There are many Bangladeshis in New Delhi, but . . .’: methodological routines and fieldwork anxieties
Authors: Ramachandran Sujata 
Published: May 2004

AbstractThanks to scholars placed both within and outside geography, real efforts have been made of late to uncover and engage with the voices of marginalised groups. While population geographers have furnished a remarkable array of methodological devices to explore migrants' being and consciousness, feminist geographers have challenged the established conceptual framework of geographical field research by underscoring the significance of self‐reflexivity, positionality, and situatedness in the field. But as this account of fieldwork with undocumented Bangladeshi migrants in the marginal and ‘illegal’ spaces of slums in New Delhi demonstrates, these nouveau routines do not engage fully with the fieldwork anxieties experienced by the researcher. In particular, critical and self‐engagements alone do not allow the investigator to deal effectively with the complicated and often opaque landscapes in which fieldwork is conducted. The article introduces these highly fragmentary social spaces, suffused with power, but also charged with ambiguities and contradictions, questioning our understanding of undocumented migrant communities and their ties with other groups in the slums. The unelaborated ‘risks of everyday life’ negotiated by unauthorised immigrants necessitate a reworking of these broad routines in order to gain access to and conduct interviews with them. No substantive results from my study are reported in the paper; it should be read as a methodological contribution. Copyright © 2004 John Wiley & Sons, Ltd.
Nanogranular Co–Al–O films prepared by laser ablation
Authors: Chayka O. , Kraus L. , Fendrych F. , Kocourek T. , Jelínek M. 
Published: May 2004

AbstractNanogranular Co–Al–O films were prepared by pulsed laser deposition from Cox(Al2O3)1−x targets. Three targets, with different Co volume fractions, were used in order to study the influence of the film composition on magnetic and transport properties. The samples deposited on room temperature substrates exhibit a granular structure consisting of Co grains with the size of few nm embedded in an insulating Al2O3 matrix. The magnetic properties show a gradual transition from a low temperature blocked regime to a high temperature superparamagnetic state. It is confirmed by the disappearance of magnetic hysteresis at high temperatures and the temperature dependence of magnetization. Magnetoresistance (MR) higher then 9% at 20 K can be found in Co26Al23O51 film. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of PS–PVP diblock copolymer topography on the magnetic properties of CoCrPt thin films
Authors: Jeong Jong‐Ryul , Choi Myung Chul , Kim Mahn Won , Shin Sung‐Chul 
Published: May 2004

AbstractThe magnetic properties and growth structure of Co68Cr18Pt14 thin films deposited on self‐assembled PS21400 (styrene)–PVP20700 (4‐vinyl pyridine) diblock copolymer surfaces were investigated using a magneto‐optical microscope magnetometer (MOMM). The perpendicular magnetic anisotropy as well as the coercivity of 200 Å CoCrPt/PS–PVP/Si(100) films in comparison with 200 Å CoCrPt/Si(100) were distinctly enhanced. An atomic force microscope (AFM) revealed that the enhanced perpendicular magnetic anisotropy and coercivity in CoCrPt/PS–PVP/Si(100) films might be ascribed to the reduction of the magnetic dipolar anisotropy of CoCrPt films having a rough surface arising from spherically modulated PS–PVP surface morphology and preferential deposition of CoCrPt on top of the PVP block. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular beam epitaxial growth of GaN and GaMnN using a single precursor
Authors: Kim K. H. , Lee K. J. , Kang H. S. , Yu F. C. , Kim J. A. , Kim D. J. , Baik K. H. , Yoo S. H. , Kim C. G. , Kim Y. S. , Kim C. S. , Kim H. J. , Ihm Y. E. 
Published: May 2004

AbstractGaMnN magnetic thin films were grown using a single GaN precursor of Et2Ga(N3)NH2C(CH3)3, and their structural and magnetic properties were investigated. The GaN layers were grown with c‐axis texture orientation. The films, however, revealed a great improvement in the crystallinity upon in‐situ and ex‐situ annealing at higher temperatures. Incorporation of Mn, however, randomized the growth direction as revealed by investigations of X‐ray diffraction and transmission electron microscopy. For high Mn flux, a cubic second phase, Mn3GaN, has precipitated. It is a structure seldom observed in other conventional molecular beam epitaxy growth. It, however, offered a high conductivity to the GaMnN matrix. The precipitated films showed a uniaxial anisotropy in the magneto‐transport. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of heat treatment on the magnetostrictive properties of Tb0.3Dy0.7Fey for 1.4 ≤ y ≤ 1.7
Authors: Kim Jong‐Chul , Kwon Oh‐Yeoul , Kwon Young‐dong , Lee Zin Hyoung 
Published: May 2004

AbstractThe effect of annealing on the microstructure and magnetostriction of Tb0.3Dy0.7Fey for 1.4 ≤ y ≤ 1.7 was investigated. As the y value decreased, the volume fraction of the eutectic phase increased and this phase leaked out from a sample during annealing above the eutectic temperature, which significantly changed the magnetostrictive properties. We compare the effects of leakage of the eutectic phase and annealing on the magnetostriction and discuss the reasons.
Opal photonic crystals impregnated with magnetite
Authors: Kodama T. , Nishimura K. , Baryshev A. V. , Uchida H. , Inoue M. 
Published: May 2004

AbstractWe report an experimental study of the fabrication of three‐dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Chemical conditions obtained at coating of SiO2 spheres with magnetite particles is used for fabrication opal‐magnetite composites. Investigations of properties of synthesized composites show that synthesis of magnetic materials can be performed inside of opal lattice by using the infiltration method, and optical properties of opal‐magnetite composites having all the features of opal photonic crystal strongly depend on volume fraction of magnetic material embedded into opal lattice. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and characteristics of a magnetic–dielectric (Fe3O4/BaTiO3) composite by ferrite plating with ultrasound irradiation
Authors: Park H. K. , Choi S. H. , Oh J. H. , Ko T. 
Published: May 2004

AbstractFe3O4‐encapsulated BaTiO3 powder was synthesized with ultrasound‐enhanced ferrite plating. The microwave absorbing properties of the synthesized Fe3O4/BaTiO3 composite powder were compared with the following powders, Fe3O4, Fe3O4/BaTiO3 mixed, and BaTiO3. The absorption bands for their specimens having the same thickness were observed at 6.9 GHz, 11.1 GHz, 8.3 GHz, and 5.8 GHz, respectively. When ultrasound was applied for more than 3 hours, Fe3O4 particles covered completely the surface of each BaTiO3 grain. The permittivity and the corecive force of a sintered composite prepared from this Fe3O4‐encapsulated BaTiO3 powder was 148.38–362.4 at 10 kHz and 2920–3600 Oe, respectively. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analytic expressions of the general magneto‐optical Kerr effects for a nanometer‐thick magnetic layer with a capping layer
Authors: You Chun‐Yeol , Shin Sung‐Chul 
Published: May 2004

AbstractWe have formulated analytic expressions for magneto‐optical Kerr effect (MOKE) of a magnetic layer covered by a capping layer, when two layers are optically thin enough. Within the first order of the thickness of the magnetic and capping layers, the polar and longitudinal magneto‐optical Kerr effects of p and s polarized waves can be approximated with simple closed forms for the general cases of an arbitrary oblique incident angle. It is found that the capping layer thickness dependent part can be separated from the first‐order term of the magnetic layer thickness, and it turns out to be the simple form for the normal incident case. The validity of the approximated expressions was examined by comparison with the exact numerical solutions, and it is confirmed that the estimated error was small enough for optically thin enough magnetic and capping layers. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetoresistance and surface properties with deposition condition for La–Sr–Mn–O thin films
Authors: Ahn Geun Young , Park Seung‐Iel , Shim In‐Bo , Cho Young Suk , Kim Chul Sung 
Published: May 2004

AbstractPolycrystalline La–Sr–Mn–O thin films were grown through RF magnetron sputtering on Si(100) substrates. The conditions for the deposition of the La–Sr–Mn–O thin films were 0, 20, 40, 60 and 80% partial oxygen pressures of the buffer gas, an RF magnetron sputtering power of 2.46 W/cm2 and a substrate temperature of room temperature. After the deposition, all the films were annealed in the air for 3 hours at 800 °C. The crystal structure, the chemical composition, the microstructure, the magnetic properties and the low‐field magnetoresistance of the La–Sr–Mn–O films were studied using X‐ray diffraction, Rutherford back‐scattering spectroscopy, atomic force microscopy, and a vibrating sample magnetometer. The crystal structure of the LSMO thin films was found to be a pseudo‐cubic perovskite. As the partial oxygen pressure increased, particle size and root mean square roughness decreased while saturation magnetization and the low‐field magnetoresistance increased. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of the magnetocaloric effect from magnetization and heat capacity data
Authors: Lee J. S. 
Published: May 2004

AbstractMagnetic refrigeration is based on the magnetocaloric effect (MCE) – the ability of some materials to heat up when magnetized and cool down when removed from the magnetic field. The available techniques for studying the MCE are: (i) direct measurements by monitoring the change in material's temperature during the application or removal of the magnetic field; and (ii) indirect calculations from experimental data of magnetization and/or heat capacity as functions of temperature and magnetic field. In this paper the procedure to evaluate the MCE from magnetization and zero‐field heat capacity data is described. The MCE – isothermal magnetic entropy change (ΔSM) and adiabatic temperature change (ΔTad) – of gadolinium (Gd) obtained by this procedure is presented. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exercise‐induced changes in exhaled nitric oxide in heart failure
Authors: Bussotti Maurizio , Andreini Daniele , Agostoni Piergiuseppe 
Published: May 2004

AbstractBackground:In heart failure abnormalities of pulmonary function are frequently observed as shown by hyperpnea, reduced lung compliance, reduced alveolar‐capillary gas diffusion, positive methacholine challenge and, during exercise, early expiratory flow limitation. Nitric oxide (NO) might be related to all the above abnormalities.Aims:We evaluated whether a correlation between exhaled NO (eNO) and lung function exists at rest and during exercise in heart failure.Methods:We studied 33 chronic heart failure patients and 11 healthy subjects with: (a) standard pulmonary function, (b) lung diffusion for carbon monoxide (DLco) including its subcomponents, capillary volume and membrane resistance and eNO both at rest and during light exercise, (c) maximal cycloergometer cardiopulmonary exercise test.Results:Forced expiratory volume in 1 s (FEV1) was reduced in heart failure patients (83±17% of predicted), as was DLco (75±18% of predicted) due to reduced membrane resistance (32.6±10.3 ml mmHg−1 min−1 vs. 39.9±6.9 in patients vs. controls, P<0.02). Exhaled NO was lower in patients vs. controls (9.7±5.4 ppm vs. 14.4±6.4, P<0.05) and was, during exercise, constant in patients and reduced in controls. No significant correlation was found between eNO and lung function. Vice‐versa eNO changes during exercise were correlated with peak exercise oxygen consumption (r=0.560, P<0.001).Conclusions:The hypothesis of a link between eNO and lung function in heart failure was not proved. The correlation between eNO changes during exercise and peak Vo2 might be due to hemoglobin oxygenation, which binds NO to hemoglobin.
Extracellular superoxide concentration increases following cerebral hypoxia but does not affect cerebral blood flow
Authors: Fabian Roderic H. , Perez‐Polo J.Regino , Kent Thomas A. 
Published: May 2004

AbstractAbnormalities of cerebral blood flow during and following hypoxia and ischemia contribute to the progression of tissue injury. Oxidative stress during and following hypoxia is known to markedly increase superoxide anion concentration. There is conflicting evidence that the concentration of superoxide anion regulates cerebral blood flow through its effect on vascular tone, although difficulties in measurement of superoxide anion complicate these studies. In order to test the hypothesis that changes in cerebral blood flow during and following hypoxia are due to changes in extracellular superoxide anion levels, we examined tissue oxygen levels by fiberoptic oximetry and superoxide anion levels using a previously validated cytochrome c coated electrode on the cortical surface and correlated these measurements to cerebral blood flow measured by laser Doppler in rats subjected to 20 min of hypoxia followed by hyperoxic reoxygenation recovery. The results showed a burst of superoxide anion with the onset of reoxygenation that temporally correlated with a transient peak in tissue oxygen tension lasting 10 min. and was eliminated by pretreatment with Cu–Zn superoxide dismutase conjugated to polyethylene glycol. Cerebral blood flow did not differ during hypoxia or recovery in the polyethylene glycol conjugated superoxide dismutase and control treatment groups. This study demonstrated no effect of increased superoxide anion concentration on cerebral blood flow during hyperoxic recovery following hypoxia.
Adolescent and adult rats respond differently to nicotine and alcohol: motor activity and body temperature
Authors: Rezvani Amir H. , Levin Edward D. 
Published: May 2004

AbstractAlcohol and nicotine are the most widely abused drugs in the world. The use of these addictive drugs often begins in adolescence, however, little is known about the different impacts of nicotine and alcohol on adolescents versus adults. This study examined both the individual and combined effects of nicotine and alcohol on body temperature and locomotor activity in adolescent and adults rats. Rats were injected with saline (SC) + saline (IP), nicotine (SC) + saline (IP), alcohol (IP) + saline (SC) or alcohol (IP) + nicotine (SC). The dose selected for nicotine was 0.2 mg/kg and for alcohol 2.5 g/kg (16% v/v). For each age/treatment, 10–13 animals were used, with each animal receiving only one treatment. In regards to body temperature, both nicotine and alcohol caused a significant age×drug interaction. The combination of nicotine and alcohol caused greater drop in body temperature in adolescent than in adult rats. Neither of the two drugs, when given alone, caused differential effects in adolescents or adult rats, though both resulted in drop in body temperature. In terms of locomotor activity, the treatment that produced a significantly different effect between adolescents and adults was nicotine alone. Nicotine significantly decreased locomotor activity in adolescent compared to adult rats. These preliminary results suggest that adolescent rats may have an increased sensitivity to nicotine and alcohol, which may consequently impact their initial addiction to these two drugs.
Hypoxia induces HIF‐1α and VEGF expression in chondrosarcoma cells and chondrocytes
Authors: Lin Chuzhao , McGough Richard , Aswad Bassam , Block Joel A. , Terek Richard 
Published: May 2004

AbstractLike other tumors, chondrosarcoma must induce neovascularity as they grow. Recent studies have demonstrated that chondrosarcoma are vascular. Since normal cartilage is a hypoxic, yet avascular tissue and since chondrosarcoma bears some phenotypic relation to cartilage, it is not clear if hypoxic pathways remain intact in these tissues. Hypoxia‐inducible factor 1α (HIF‐1α) is the inducible subunit of the HIF‐1 transcription factor that regulates genes involved in the response to hypoxia, some of which promote neovascularity. Vascular endothelial growth factor (VEGF) is one of the genes upregulated by HIF‐1 and is the primary cytokine related to angiogenesis. In this study we examined the response of chondrocytes and chondrosarcoma cell lines to hypoxia. We found that both normal and malignant chondrocytes increased HIF‐1α protein expression in an oxygen concentration dependent manner and also increased VEGF mRNA expression in response to hypoxia. HIF‐1α protein and VEGF mRNA decreased when chondrosarcoma cells were transfected with siRNA targeting HIF‐1α prior to hypoxia exposure, suggesting that HIF‐1α expression resulted in increased VEGF expression. The role of the HIF‐1α/VEGF pathway in angiogenesis in chondrosarcoma in vivo and its usefulness as a target for antiangiogenic treatment strategies for this tumor requires further investigation. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.