bluuebunny/crossref_metadata_2025_split huggingface dataset:
β‐Carotene storage, conversion to retinoic acid, and induction of the lipocyte phenotype in hepatic stellate cells
Authors: Martucci Renata B. , Ziulkoski Ana L. , Fortuna Vitor A. , Guaragna Regina M. , Guma Fátima C.R. , Trugo Luiz C. , Borojevic Radovan 
Published: April 2004

AbstractHepatic stellate cells (HSCs) are the major site of retinol (ROH) metabolism and storage. GRX is a permanent murine myofibroblastic cell line, derived from HSCs, which can be induced to display the fat‐storing phenotype by treatment with retinoids. Little is known about hepatic or serum homeostasis of β‐carotene and retinoic acid (RA), although the direct biogenesis of RA from β‐carotene has been described in enterocytes. The aim of this study was to identify the uptake, metabolism, storage, and release of β‐carotene in HSCs. GRX cells were plated in 25 cm2 tissue culture flasks, treated during 10 days with 3 μmol/L β‐carotene and subsequently transferred into the standard culture medium. β‐Carotene induced a full cell conversion into the fat‐storing phenotype after 10 days. The total cell extracts, cell fractions, and culture medium were analyzed by reverse phase high‐performance liquid chromatography for β‐carotene and retinoids. Cells accumulated 27.48 ± 6.5 pmol/L β‐carotene/106 cells, but could not convert it to ROH nor produced retinyl esters (RE). β‐Carotene was directly converted to RA, which was found in total cell extracts and in the nuclear fraction (10.15 ± 1.23 pmol/L/106 cells), promoting the phenotype conversion. After 24‐h chase, cells contained 20.15 ± 1.12 pmol/L β‐carotene/106 cells and steadily released β‐carotene into the medium (6.69 ± 1.75 pmol/ml). We conclude that HSC are the site of the liver β‐carotene storage and release, which can be used for RA production as well as for maintenance of the homeostasis of circulating carotenoids in periods of low dietary uptake. © 2004 Wiley‐Liss, Inc.
Assessing compliance with homework assignments: Review and recommendations for clinical practice
Authors: Kazantzis Nikolaos , Deane Frank P. , Ronan Kevin R. 
Published: April 2004

AbstractDespite the emphasis of homework assignments in psychotherapy research and practice, methods to assess homework compliance have been relatively neglected. This article presents a brief review of 32 studies that described the assessment of homework compliance, and evaluated homework compliance in relation to treatment outcome. More than half of the studies relied on a single source of compliance data (n = 23), eight studies involved retrospective accounts, and only four studies used the same measure of homework compliance. The vast majority of studies focused on the assessment of “homework compliance” without consideration of the “quality of homework completion” or other key factors. A more comprehensive framework for homework compliance is discussed, and a new Homework Rating Scale (HRS) is proposed as the first step towards assisting the field in a more reliable and valid assessment of homework compliance. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Snow cover in eastern Europe in relation to temperature, precipitation and circulation
Authors: Bednorz Ewa 
Published: April 2004

AbstractThe basic characteristics of snow cover occurrence in eastern Europe are described. For each month from October to May the range of ‘active’ snow‐cover areas in Europe was determined. The boundary criterion for ‘active’ regions was adopted as snow‐cover probability of between 10 and 90%. The correlation coefficients between the snow‐cover characteristics (number of days with snow cover and its monthly mean depth) and other climatic variables (temperature and precipitation) were calculated. A strong positive correlation between the annual number of days with snow cover and the annual number of days with mean temperature <0 °C was discovered for most parts of the study area. A negative correlation between the monthly number of days with snow cover and monthly mean temperature was found and its spatial distribution was analysed. A positive correlation between snow depth and precipitation appeared significant only in some areas. The influence of atmospheric circulation, expressed by North Atlantic oscillation (NAO) index values, on snow cover in the particular months was analysed. The correlation between the number of days with snow cover and the NAO index is large and statistically significant only in central Europe and it becomes insignificant to the east of 30° λ E. High values are noted only in the winter months. In autumn and spring, when the range of the ‘active’ areas moves to the east and the NAO becomes weak, the correlation is very small. Copyright © 2004 Royal Meteorological Society
The development of monthly temperature series for Scotland and Northern Ireland
Authors: Jones P. D. , Lister D. 
Published: April 2004

AbstractWe develop monthly temperature series (mean, maximum and minimum) for the Scottish mainland (SMT), the northern and northwestern Scottish Isles (SIT, Orkneys, Shetlands and Outer Hebrides) and for Northern Ireland (NIT). The series were developed from eight long station records, five over SMT, two for SIT and one for NIT. The series are reliable back to 1866 for all three regions, but extensions to 1800 and 1827 for SMT and SIT are less so, likely due to direct solar insolation effects in the summer months. All three regions show long‐term statistically significant seasonal warming over both 1861–2000 and 1901–2000, except for the winter season. For the calendar year, the temperature change explained by a linear trend over 1861–2000 is 0.69°C, 0.64°C and 0.77°C for SMT, SIT and NIT respectively. Of the 51 (12 months + 4 seasons + annual = 17 × 3 regions) warmest values, 23 have occurred after 1987. Of the coldest extremes, 30 occurred between 1861 and 1899 and the last cold extreme months were in 1952. Copyright © 2004 Royal Meteorological Society
Spatial and temporal variability of the daily rainfall regime in Catalonia (northeastern Spain), 1950–2000
Authors: Lana X. , Martínez M.D. , Serra C. , Burgueño A. 
Published: April 2004

AbstractSpatial and temporal patterns in the daily rainfall regime of Catalonia (northeastern Spain) recorded for the 1950–2000 period are analysed from several points of view, including the irregularity of the time series in terms of entropy, the Mann–Kendall test for time trends, a principal component analysis (PCA), an average linkage (AL) clustering algorithm and, finally, a power spectrum analysis, which includes a comparison of white‐noise and Markovian red‐noise hypotheses. The analyses are based on three monthly variables derived from the amounts recorded on a daily basis: the average daily rainfall and the standard deviation of the daily rainfall for each month, together with the corresponding coefficient of variation. The joint spatial–temporal variability is manifested by the irregularity index, which is characterized by relevant values in all cases and gradients from the north (Pyrenees and Pre‐Pyrenees mountain ranges) to the south (Ebro Valley) and to the Mediterranean coast. The interpretation of the factor scores derived from the PCA and of the clusters obtained from the AL algorithm also describes the complex spatial distribution of the daily rainfall regime, given that the effects of atmospheric circulation patterns on rainfall regimes are conditioned by the complex orography of Catalonia and its proximity to the Mediterranean Sea. The factor loadings associated with the PCA also suggest a distinction between hot, cold and mild seasons. Finally, it is worth noting that monthly series are usually accompanied by white background noise and, in a few cases, signs of Markovian behaviour and some significant periodicities, which are generally of less than 10 months and which change from one cluster to another. Copyright © 2004 Royal Meteorological Society
The scaling law relating world point‐precipitation records to duration
Authors: Galmarini S. , Steyn D. G. , Ainslie B. 
Published: April 2004

AbstractIn order to understand the remarkable six‐orders of magnitude scaling law underlying worldwide point‐precipitation records, we analyse precipitation data from a wide range of stations worldwide. The analysis shows that single‐exponent scaling laws exist only for single stations experiencing extremely high precipitation. This analysis, and a consideration of the sequence of earlier published precipitation records, leads us to conclude that record precipitation exists because of an optimization of all factors leading to precipitation. This idea is incorporated into a scheme for simulating the record–duration curve for precipitation, which utilizes only the probability distribution function for precipitation amounts, the temporal autocorrelation of precipitation and a starting record–duration point. The simulation suggests record precipitation is asymptotically independent of most underlying physical processes. Copyright © 2004 Royal Meteorological Society
Water vapour transport associated with tropical–temperate trough systems over southern Africa and the southwest Indian Ocean
Authors: Todd Martin C. , Washington Richard , Palmer Paul I. 
Published: April 2004

AbstractTropical–temperate trough (TTT) systems are the dominant rain‐producing synoptic type over southern Africa. They represent an important mechanism of poleward transport of energy and momentum. This paper provides an analysis of water vapour transport in TTT systems. An objective sampling of TTT systems is conducted from analysis of daily satellite rainfall products. During the sampled TTT events, rain bands extend from tropical southern Africa near 10 °S to the midlatitudes of the southwest Indian Ocean. The divergent and non‐divergent (streamfunction) components of vertically integrated water vapour flux associated with major TTT events are calculated, from National Centers for Environmental Prediction reanalysis data. During TTT events the streamfunction circulation dominates water vapour transport, although adjustments to the divergent component are relatively more important. The results indicate that TTT events facilitate a substantial water vapour flux from the tropics into the midlatitudes. Water vapour transport to the midlatitudes along the TTT axis is facilitated largely by changes to the streamfunction, associated with a strengthening and eastward displacement of the Indian Ocean high, and the advent of midlatitude transients. It is also shown that TTT systems are major regions of moisture convergence. The high vapour concentrations along the full extent of the TTT rain bands are maintained by the divergent circulation. The structure of these divergent vapour flux anomalies is suggestive of adjustments to the Walker circulation, involving strong anomalous divergence over the maritime continent/west Pacific and a weaker enhancement of the major divergence centre over the tropical Atlantic. Copyright © 2004 Royal Meteorological Society
A model intercomparison study of climate change‐signals in extratropical circulation
Authors: Rauthe Monika , Hense Andreas , Paeth Heiko 
Published: April 2004

AbstractSince 1970, the observed time series of various extratropical circulation modes have revealed remarkable trends. In many studies it has been suggested that these trends may be related to global warming due to increasing greenhouse gas (GHG) concentrations. Coupled climate model scenario experiments may give a hint of such a relationship. Here, a large model intercomparison study is presented, incorporating most state‐of‐the‐art models of the international modeller community with GHG and GHG plus sulphate aerosol (SUL) forcing, in order to quantify the signals common to different climate models and to determine the degree of uncertainty. The extratropical circulation candidates are the Arctic oscillation (AO), the North Atlantic oscillation (NAO), the Aleutian low (AL) and the Antarctic oscillation (AAO).Most climate models agree in predicting positive AO and AAO trends into the 21st century, these being different from the respective results of long‐term control experiments. The NAO appears to be less sensitive to radiative forcing, with slightly positive and negative trends occurring in different models. The AL tends to strengthen in several models with GHG + SUL forcing. Projecting the spatial structure of the circulation modes onto the trend patterns of mean sea‐level pressure (SLP) indicates that, in particular, the AO and AAO contribute considerably to the simulated long‐term trends in SLP. Intermodel variations in Northern Hemisphere SLP trends become predominantly apparent over the mountainous regions and the North Pacific. In the Southern Hemisphere, the Antarctic region is subject to large model uncertainties. The multi‐decadal trends of all circulation modes except the NAO are statistically significant in the majority of the climate‐change experiments. At the interannual time scale, external radiative forcing does account for a small but statistically significant part of total multi‐model variability, but this part is of the same order of magnitude as the systematic differences between the models. At decadal time scales, the external impact clearly stands out from the other sources of variability. Present‐day climate models mostly agree in predicting a strengthening of the annular modes AO and AAO. As all models generally project a deepening of SLP over the polar caps, time series indicative of these regions might be a more appropriate measure of the sensitivity of extratropical circulation. Copyright © 2004 Royal Meteorological Society
Effects of stereotactic neurosurgery on postural instability and gait in Parkinson's disease
Authors: Bakker Maaike , Esselink Rianne A.J. , Munneke Marten , Limousin‐Dowsey Patricia , Speelman Hans D. , Bloem Bastiaan R. 
Published: April 2004

AbstractPostural instability and gait disability (PIGD) are disabling signs of Parkinson's disease. Stereotactic surgery aimed at the internal globus pallidus (GPi) or subthalamic nucleus (STN) might improve PIGD, but the precise effects remain unclear. We performed a systematic review of studies that examined the effects of GPi or STN surgery on PIGD. Most studies examined the effects of bilateral GPi stimulation, bilateral STN stimulation, and unilateral pallidotomy; we, therefore, only performed a meta‐analysis on these studies. Bilateral GPi stimulation, bilateral STN stimulation, and to a lesser extent, unilateral pallidotomy significantly improved PIGD, and more so during the ON phase than during the OFF phase. © 2004 Movement Disorder Society
Cigarette smoking in Parkinson's disease: Influence on disease progression
Authors: Alves Guido , Kurz Martin , Lie Stein A. , Larsen Jan P. 
Published: April 2004

AbstractPrevious studies have shown an inverse association between smoking and the prevalence of Parkinson's disease (PD), suggesting that smoking may induce a biological protection against nigral neuronal damage. In 1993, we examined the frequency of cigarette smokers among 239 patients with PD and two control groups. In addition, the progression of parkinsonism and other clinical features were followed prospectively in smoking and nonsmoking PD patients over an 8‐year period. Mortality in the two PD groups was also examined. We found a 50% higher prevalence of smokers in the control groups than in patients with PD. In contrast, during the follow‐up period, there were no significant differences in progression of parkinsonism, cognitive impairment, and mood in smoking and nonsmoking patients with PD. Mortality was also similar in the two groups. The lack of influence on disease progression may indicate that cigarette smoking does not have a major neuroprotective effect in patients with already diagnosed PD. © 2004 Movement Disorder Society
Development of donor‐specific chimerism and tolerance in composite tissue allografts under αβ‐T‐cell receptor monoclonal antibody and cyclosporine a treatment protocols
Authors: Ozer Kagan , Izycki Dariusz , Zielinski Maciej , Siemionow Maria 
Published: April 2004

AbstractRecently, we induced donor‐specific tolerance to rat hindlimb allografts under a 35‐day course of αβ‐T‐cell receptor monoclonal antibody (αβ‐TCR mAb) and cyclosporine A (CsA). In this report, we investigated the role of shorter αβ‐TCR/CsA protocols on tolerance induction. We performed 52 hindlimb transplantations, between Lewis‐Brown‐Norway (LBN, F1) donors and Lewis recipients to test the impact of 21‐, 7‐, and 5‐day protocols of combined αβ‐TCR/CsA treatment on tolerance induction. Donor‐specific tolerance and immunocompetence were tested by mixed lymphocyte reaction (MLR) in vitro and by standard skin grafting in vivo. The efficacy of immunosuppressive protocol and donor‐specific chimerism was assessed by flow cytometry. All transplants under 5, 7, and 21 days of combined αβ‐TCR/CsA therapy survived over 350 days. Clinical tolerance and immunocompetence were confirmed by skin grafting in vivo and MLR in vitro. Flow cytometry revealed a high level of donor chimerism in the peripheral blood of long‐term survivors. The extention of survival of limb allografts and allo‐unresponsiveness were directly associated with the development of stable chimerism in the tolerant recipients. © 2004 Wiley‐Liss, Inc.
The complete classification of flaps
Authors: Hallock Geoffrey G. 
Published: April 2004

AbstractWhereas the permutations and combinations in our arsenal of free flaps continue to increase exponentially, the lack of a coherent nomenclature system has caused this often to appear as only a haphazard array of bewildering possibilities. A simplified nomenclature schema is essential to enhance the acceptance and universal application of, as well as accurately describe, many of these new flap options. A minor modification of prior anatomical systems that incorporates all possible distinguishing characteristics in describing any given flap is an intrinsic part of the system, but the primary focus in flap identification is centered around its vascular supply. Several examples are given to illustrate how the complete classification of every free flap can be possible in a reproducible and highly interpretable fashion. © 2004 Wiley‐Liss, Inc.
The maximum‐leaf spanning tree problem: Formulations and facets
Authors: Fujie Tetsuya 
Published: April 2004

AbstractThe Maximum Leaf Spanning Tree Problem (MLSTP) is to find a spanning tree in a given undirected graph, whose number of leaves (vertices of degree 1) is maximum. In this article, we consider an integer programming approach to the MLSTP. We provide two formulations of the MLSTP and study the facial structure of polytopes arising from the formulations. Moreover, several relaxation problems are compared. © 2004 Wiley Periodicals, Inc.
A directed cycle‐based column‐and‐cut generation method for capacitated survivable network design
Authors: Rajan Deepak , Atamtürk Alper 
Published: April 2004

AbstractA network is said to be survivable if it has sufficient capacity for rerouting all of its flow under the failure of any one of its edges. Here, we present a polyhedral approach for designing survivable networks. We describe a mixed‐integer programming model, in which sufficient slack is explicitly introduced on the directed cycles of the network while flow routing decisions are made. In case of a failure, flow is rerouted along the slacks reserved on directed cycles. We give strong valid inequalities that use the survivability requirements. We present a computational study with a column‐and‐cut generation algorithm for designing capacitated survivable networks. © 2004 Wiley Periodicals, Inc.
Developmental regulation of spine and filopodial motility in primary visual cortex: Reduced effects of activity and sensory deprivation
Authors: Konur Sila , Yuste Rafael 
Published: April 2004

AbstractDendritic protrusions are highly motile during postnatal development. Although spine morphological plasticity could be associated with synaptic plasticity, the function of rapid spine/filopodial motility is still unknown. To investigate the role of spine motility in the development of the visual cortex and its relation with critical periods, we used two‐photon imaging of neurons from layers receiving visual input in developing mouse primary visual cortex and compared motility between control and visually deprived animals. Spine and filopodia motility was prominent during early synaptogenesis (P11–P13) but greatly decreased after P15. This “switch” was coincident with a 2.5‐fold increase in protrusion density and spine formation. Spine motility was not regulated during the critical period for monocular deprivation (P19–P34). Moreover, delaying the critical period by dark rearing did not delay the normal developmental decrease of spine motility, but caused a modest further reduction in motility at P28–P35. Dark rearing and enucleation also mildly reduced spine motility before eye opening and dark rearing reduced the proportion of filopodia. We conclude that (1) rapid spine motility is not related to critical period plasticity, but is likely to play a role in early synaptogenesis, and (2) neuronal activity stimulates spine motility during synaptogenesis and promotes the appearance of dendritic filopodia. © 2004 Wiley Periodicals, Inc. J Neurobiol 59: 236–246, 2004
Use of targetable gfp‐tagged neuropeptide for visualizing neuropeptide release following execution of a behavior
Authors: Husain Qasim M. , Ewer John 
Published: April 2004

AbstractPrevious work has shown that a transgene consisting of a fusion between the rat atrial natriuretic peptide and a green fluorescent protein reporter (ANF‐gfp) is processed, localized, and released, as would be an endogenous neuropeptide when it is expressed in the nervous system ofDrosophila melanogasterusing the GAL4/UAS expression system. Here we have tested the utility of this targetable transgene for detecting neuropeptide release following the execution of a peptide‐controlled behavior. For the behavior we used ecdysis, the behavior expressed by insects to shed their old cuticle at the end of the molt. We found that larval ecdysis was accompanied by a readily detectable reduction in gfp fluorescence from relevant secretory cells in the periphery and peptidergic neurons in the CNS. We also found that expression of the ANF‐gfp products did not have detrimental effects on larval ecdysis or adult circadian rhythmicity, when the transgene was expressed in peptidergic cells that are known to control these behaviors. Finally, we used a broadly expressed GAL4 driver to show that the UAS‐ANF‐gfp transgene could be used to identify axons that show a reduction in gfp fluorescence following the expression of ecdysis behavior. These findings, coupled with the availability of an increasing number of strains bearing different GAL4 drivers, suggest that this transgene will be a useful tool for identifying peptidergic neurons and secretory cells (and, eventually, their secretory product) that release their peptide content during the occurrence, in the intact animal, of a developmental, physiological or behavioral process of interest. © 2004 Wiley Periodicals, Inc. J Neurobiol 59: 181–191, 2004