bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neu differentiation factor regulates tau protein and mRNA in cultured neonatal oligodendrocytes
Authors: LoPresti Patrizia , Muma Nancy A. , De Vries George H. 
Published: September 2002

AbstractAxonal signals activate myelinogenesis via regulation of the extent to which oligodendrocyte (OLG) processes wrap around the axon. The cytoskeleton in OLG processes is actively involved in myelination and is a putative target for axonal regulation of myelination. The axon‐associated neuregulins may regulate the cytoskeleton extensions in OLG processes. Here, we report that the neuregulin neu differentiation factor (NDF) increases the expression of tau mRNA and tau protein in OLGs. Treatment of neonatal OLGs with α‐NDF or β‐NDF resulted in dramatic increases in the length of OLG processes, which appeared either as singular unbranched extensions or as a network of extensively branched processes. By immunoblot analysis with tau‐1 mAb, which recognizes the dephosphorylated form of the tau proteins, neonatal OLGs treated with α‐NDF or β‐NDF, had an increase in tau protein levels. The increase of tau levels in β‐NDF–treated cells is much greater than the twofold increase present in α‐NDF–treated cells. By immunoblot analysis with the phosphorylation‐insensitive tau‐5 mAb, β‐NDF–treated cells had a twofold increase in tau. Immunoblot analysis suggest that α‐NDF and β‐NDF promote a twofold increase in the tau protein levels in OLG, with the β‐factor also promoting a tau dephosphorylation. Using promoters spanning the amino‐terminal region of tau, we found that OLGs treated with α‐NDF or β‐NDF contained approximately twofold more tau mRNA than untreated cells. However, there was no qualitative difference between control and NDF‐treated cells in the pattern of tau mRNA isoforms expressed. A model is proposed in which the axonal NDF‐induced regulation of tau expression in OLGs may be part of the mechanism by which the axon regulates myelination. GLIA 35:147–155, 2001. © 2001 Wiley‐Liss, Inc.
Nitric oxide synthase expression and function in embryonic and adult cardiomyocytes
Authors: Bloch Wilhelm , Addicks Klaus , Hescheler Jürgen , Fleischmann Bernd K. 
Published: September 2002

AbstractNitric oxide (NO) is an important signalling molecule that plays a relevant role in different cell systems, among them the adult heart. The effects of NO are primarily mediated through modulation of Ca2+ homeostasis, myofibrillar contractility, and metabolic regulation in cardiomyocytes. Recent evidence also suggests an important role of NO for cardiomyogenesis by modulating proliferation and differentiation and regulating cardiac function. In the embryonic, but also the healthy and diseased, adult mammalian heart, the inducible (iNOS) and the endothelial (eNOS) nitric oxide synthases (NOS) are detected. However, the expression pattern of NO and its function differ during development. Furthermore, under pathophysiological conditions NOS expression can also change and cause impairment of cardiac performance and cytotoxic effects. The present review focuses on the role and function of NO during cardiomyogenesis, the mechanisms responsible for eNOS availability, and the paracrine effects of NO generated by cardiomyocytes. Microsc. Res. Tech. 55:259–269, 2001. © 2001 Wiley‐Liss, Inc.
Docking of combinatorial peptide libraries into a broadly cross‐reactive human IgM
Authors: Yuriev Elizabeth , Ramsland Paul A. , Edmundson Allen B. 
Published: September 2002

AbstractA monoclonal IgM cryoglobulin with diverse binding behavior was isolated from a patient (Mez) with Waldenström's macroglobulinemia. It gave very high titers in the binding of combinatorially synthesized libraries of peptides ranging in size from two to eight residues. The crystal structure of Mez Fv revealed that the binding site was divided into two cavities of unequal volumes with dimensions and chemical properties that were compatible with the binding of peptides. Access to this unique combination of structural information and peptide binding data led us to carry out Mez‐peptide docking simulations to gain insight into the Mez binding propensities. In the present article, the results for docking of five peptide libraries are combined with discussions of the methods and approximations involved in the docking process. We analyze the origins of peptide binding affinity for Mez IgM in terms of its cross‐reactivity and its structural preferences. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

3‐D

three‐dimensional

Ab

antibody

A

absorbance

C

constant

CDR

complementarity‐determining region

CH

constant domain of the heavy chain

ELISA

enzyme‐linked immunosorbent assay

Fv

fragment variable

H

heavy

HB

hydrogen bond

L

light

PDB

Protein Data Bank

V

variable

VH

variable region of the heavy chain

VL

variable region of the light chain

vdW

van der Waals
The spatial and temporal behaviour of the lower stratospheric temperature over the Southern Hemisphere: the MSU view. Part II: spatial behaviour
Authors: Salles M. Alejandra , Canziani Pablo O. , Compagnucci Rosa H. 
Published: September 2002

AbstractMonthly lower stratosphere temperature anomalies in a layer centred about 70 hPa, from the MSU data set are analysed for the period 1979–1997. T‐mode approach principal component analysis (PCA) is used in order to obtain the leading spatial anomaly patterns and their sequences of occurrence throughout the period under study. Five principal components (PCs) are significantly different from the spatial distribution of noisy data. The patterns given by the PC scores represent ten typical spatial anomaly patterns: five correspond to the direct mode, that is to say anomaly fields with the same sign as the PC score patterns, and five have the opposite sign. The first three PCs represent simple spatial temperature anomaly distributions, with zonal wave 0 to wave 2 wave structures. The following significant PCs, orders four and five, display a more complex spatial behaviour, with wave 3 wave structures. The first two PC's frequency distribution in time, given by the PC loadings time series, do not show noticeable changes throughout the period analysed. The remaining three PCs show changes in their frequency of occurrence that might be associated with the negative trends in the lower stratosphere temperature, as well as to the other different features observed in the real temperature anomaly time series for the grid points in the Southern Hemisphere. The latter are studied with the PCA in the S‐mode approach in the companion paper (Compagnucci et al., 2001. International Journal of Climatology 21: 419–437). Copyright © 2001 Royal Meteorological Society
Winter and summer Hadley circulations over peninsular India as monitored by MST radar at Gadanki (13.47°N, 79.18°E)
Authors: Annes V.H. , Mohankumar K. , Joseph P.V. 
Published: September 2002

AbstractThe vertical velocity observed using the mesosphere–stratosphere–troposphere (MST) radar at Gadanki (13.47°N, 79.18°E), India, shows that downward motion prevails in the troposphere and lower stratosphere during both winter and summer. Zonal and meridional components of winds over the Gadanki region are compared with the Hadley circulation over the peninsular Indian region obtained from National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysed data. An anomalous northerly wind is observed in the lower troposphere over the radar station during summer monsoon months instead of southerlies according to the reverse Hadley cell theory. NCEP/NCAR reanalysed data show that this anomaly covers a large area around peninsular India. Copyright © 2001 Royal Meteorological Society
Identification of highest magnitude coastal storm events over western Ireland on the basis of wind speed and duration thresholds
Authors: MacClenahan P. , McKenna J. , Cooper J.A.G. , O'Kane B. 
Published: September 2002

AbstractThis paper presents a computer‐based method for the analysis of the wind record from coastal weather stations to identify storm events based on wind speed and duration thresholds. Various combinations of thresholds help identify two main storm signatures, i.e. peak‐like and plateau‐like profiles. Seven further types of storm are defined according to their intensity. The date of each event provided by the program is a key item in the analysis that allows for the establishment of storm catalogues at individual weather stations. Catalogues that identify particular storms produce information on the varying local storm regime of the western Irish seaboard and provide input to the understanding of the climatology of the wider northeastern Atlantic region. Copyright © 2001 Royal Meteorological Society
Buried palaeosols of the Nevado de Toluca: an alternative record of Late Quaternary environmental change in central Mexico
Authors: Sedov Sergey , Solleiro‐Rebolledo Elizabeth , Gama‐Castro Jorge E. , Vallejo‐Gómez Ernestina , González‐Velázquez Arelia 
Published: September 2002

AbstractBuried palaeosols of central Mexico, not previously analysed from a palaeopedological standpoint, have helped to develop a reliable regional model of Late Quaternary climatic change. This paper focuses upon morphological and micromorphological properties, particle‐size distribution, and extractable Fe, Al and Si of seven palaeosols (named PT1–PT7) in the vicinity of the Nevado de Toluca volcano. The characteristics of Andic Cambisol PT1, similar to those of modern soils in semi‐arid environments, indicate a drier climate in the first half of the Holocene. Humic Andosols PT2–PT4 are analogous to modern volcanic soils of humid forest environments. They show evidence that a moist palaeoclimate prevailed during marine oxygen isotope stages (OIS) 2 and 3. Luvisols PT5 and PT6, which are assumed to have formed at the end of marine OIS 5 to marine OIS 4, also indicate humid conditions. We attribute the differences between Andosols PT2–PT4 and Luvisols PT5–PT7 to variations in the duration in the pedogenesis rather than to changes in palaeoclimate. Micromorphological features of Andosol to Luvisol transition confirm that these soils form an evolutionary sequence. Being for the most part consistent with lacustrine records, the palaeosol properties do not reflect the episodes of ‘drier climate’ during the Last Glacial Maximum, however, as shown by diatom and palynological data from lake sediments. Mesoclimate variations and/or incompleteness of ‘soil memory’, reflecting mostly periods of humid pedogenesis, probably provide the reason for this disagreement. Copyright © 2001 John Wiley & Sons, Ltd.
Integrated marine and terrestrial evidence for abrupt Congo River palaeodischarge fluctuations during the last deglaciation
Authors: Marret Fabienne , Scourse James D. , Versteegh Gerard , Fred Jansen J. H. , Schneider Ralph 
Published: September 2002

AbstractWe present a high‐resolution reconstruction of tropical palaeoenvironmental changes for the last deglacial transition (18 to 9 cal. kyr BP) based on integrated oceanic and terrestrial proxies from a Congo fan core. Pollen, grass cuticle, Pediastrum and dinoflagellate cyst fluxes, sedimentation rates and planktonic foraminiferal δ18O ratios, u37K′ sea‐surface temperature and alkane/alkenone ratio data highlight a series of abrupt changes in Congo River palaeodischarge. A major discharge pulse is registered at around 13.0 cal. kyr BP which we attribute to latitudinal migration of the Intertropical Convergence Zone (ITCZ) during deglaciation. The data indicate abrupt and short‐lived changes in the equatorial precipitation regime within a system of monsoonal dynamics forced by precessional cycles. The phases of enhanced Congo discharge stimulated river‐induced upwelling and enhanced productivity in the adjacent ocean. Copyright © 2001 John Wiley & Sons, Ltd.
Impact of deforestation on soil physicochemical characteristics, microbial biomass and microbial activity of tropical soil
Authors: Sahani U. , Behera N. 
Published: September 2002

AbstractThe study dealt with the assessment of the impact of deforestation on tropical soil through a comparative analysis of physicochemical and microbiological parameters of natural forest and a deforested barren site. With significant decline in clay, texturally the soil of the deforested barren site was observed to be different from that of natural forest. Bulk density and porosity data revealed structural deterioration of deforested barren soil. The soil hydrological regime was also adversely affected by the deforestation. Levels of soil organic carbon, total nitrogen, microbial biomass C, N and microfungal biomass also exhibited significant decline in deforested site. Analysis of microbial respiratory quotient (q CO2) was also observed to be impaired in the deforested site. Copyright © 2001 John Wiley & Sons, Ltd.
Seedbank phytosociology of the Strandveld Succulent Karoo, South Africa: a pre‐mining benchmark survey for rehabilitation
Authors: De Villiers A. J. , Van Rooyen M. W. , Theron G. K. 
Published: September 2002

AbstractPrior to the mining of heavy minerals, the seedbank of the Strandveld Succulent Karoo was investigated to serve as a benchmark for the future rehabilitation of the area. Seedbank composition and species' abundance were determined with the seedling emergence method. By using the Braun‐Blanquet method, five main vegetation units were identified in concordance with results obtained for the standing vegetation. A total of 108 species were recorded in the seedbank, which represents c. 50 per cent of the species recorded in the standing vegetation of the total study area. Seven annual species (3 per cent) were unique to the soil seedbank. On community level, similarity in species composition between the standing vegetation and the soil seedbank ranged between 39·2 per cent and 48·8 per cent, with a similarity of 54·3 per cent for the total study area. Annual and perennial species' similarity in species composition between the standing vegetation and the seed bank totalled 74·8 per cent and 43·1 per cent respectively. Post‐mining topsoil replacement as well as seeding and transplanting of selected local species will be essential to revegetate this area. Copyright © 2001 John Wiley & Sons, Ltd.
Recognizing large donations to public goods: an experimental test
Authors: Clark Jeremy 
Published: September 2002

AbstractPrivate charities often publicise generousindividualcontributions or contributors, possibly to encourage others to give. In contrast, public good experiments used to study voluntary giving commonly tell participants only oftotalcontributions. This paper reports an experimental test of the effect on contributions of supplying additional selective information. A control treatment is run that reveals only total contributions over ten one‐shot decision rounds. This is compared to a second treatment that also informs subjects of the maximum contribution made in their group after each round. In a third treatment, subjects are further given the opportunity to make costly rewards to the maximum contributor. Revealing generous contributions appears to raise average contributions slightly. Surprisingly, adding the ability to reward large contributors does little to generate further increases, though it significantly raises the variance of contributions. Copyright © 2002 John Wiley & Sons, Ltd.
Modelling of ciliary downstream collecting in suspension‐feeding invertebrates
Authors: Mayer Stefan 
Published: September 2002

AbstractThe motion of fluid and suspended particles in ciliary downstream collecting suspension feeding is investigated on the basis of both experimental and numerical work. Throughout the paper, the suspension‐feeding polychaete Sabella penicillus is chosen to be the model species. Particle retention rate measurements indicate that S. penicillus is able to retain effectively particles of sizes much smaller than the overall size of its filtering unit. From frame‐by‐frame analysis of microscopical video recordings of the feeding organ of S. penicillus particle trajectories and velocities are inferred. By numerically solving the quasi‐steady Stokes equations for creeping flow in a boundary integral equation formulation and by introducing simple steady and unsteady cilia models a simple computational model of the S. penicillus filtering unit is constructed. A percentage of computed fluid particle trajectories is found to follow pathlines which resemble the experimentally observed particle capture. The results indicate that particle capture in suspension‐feeding can be realized solely by particle kinematics of locally driven creeping flow field as they exist in ciliary driven flow. Copyright © 2001 John Wiley & Sons, Ltd.
Ligand–macromolecule complexes: affinity index determination by selective nuclear relaxation analysis
Authors: Rossi C. , Bonechi C. , Martini S. , Ricci M. , Corbini G. , Corti P. , Donati A. 
Published: September 2002

AbstractProton NMR selective and non‐selective spin–lattice relaxation rate measurements were used to monitor the strength of the overall complexation behaviour of a ligand (carbamazepine) toward a macromolecular receptor (albumin). The ‘affinity index,’ a quantitative parameter related to the strength of the ligand–macromolecule interaction, was determined from the experimental contribution of the bound ligand molar fraction to the observed selective spin–lattice relaxation rate. The effect of a second ligand (lamotrigine) on the carbamazepine–albumin interaction was also investigated and was found to have a modulation effect on the carbamazepine–albumin interaction. Copyright © 2001 John Wiley & Sons, Ltd.
Haptoglobin inhibits lecithin‐cholesterol acyltransferase in human ovarian follicular fluid
Authors: Balestrieri Marco , Cigliano Luisa , Simone Maria Laura De , Dale Brian , Abrescia Paolo 
Published: September 2002

AbstractThe activity of the enzyme lecithin‐cholesterol acyltransferase (LCAT; E.C. 2.3.1.43) is involved in the removal of cholesterol excess from peripheral cells. This activity is stimulated by the HDL (high density lipoprotein) apolipoprotein A1 (ApoA1). Haptoglobin (Hpt) was previously found to be associated with ApoA1 in ovarian follicular fluid. LCAT activity was analyzed in follicular fluids, collected from an IVF program, containing different amounts of Hpt or Hpt/ApoA1 ratio. Addition of purified Hpt to follicular fluid caused a decrease in the enzyme activity, which was measured as the rate of synthesis of cholesteryl esters. In the fractions of fluid proteins, as obtained by gel filtration chromatography, Hpt and HDL were titrated by ELISA while the LCAT activity was assayed by using radioactive cholesterol and purified HDL. When isolated LCAT was incubated with fractions containing different Hpt/ApoA1 ratios, the enzyme activity was found negatively correlated with the Hpt/ApoA1 ratio (P < 0.01). LCAT kinetic parameters were measured in two fractions with the same amount of ApoA1 (5 μg/ml) but different amounts of Hpt (0.69 or 3.77 μg/ml): the Vmax did not change while the Km values were 24.1 or 78.6 μM in the presence of the low or high Hpt level, respectively. The analysis of fluids associated with cytoplasmically mature MII oocytes, in a cross‐sectional study, confirmed that a negative correlation exists between the Hpt/ApoA1 ratio and the LCAT activity (P < 0.01). The results suggest that Hpt inhibits the reverse transport of cholesterol by preventing ApoA1 stimulation of the LCAT activity. Mol. Reprod. Dev. 59:186–191, 2001. © 2001 Wiley‐Liss, Inc.
Simultaneous sampling of event‐related BOLD responses in auditory cortex and brainstem
Authors: Backes W.H. , van Dijk P. 
Published: September 2002

AbstractEvent‐related functional magnetic resonance imaging (fMRI) was applied to investigate blood oxygen level dependent (BOLD) responses in the human auditory system. Auditory fMRI is hindered by the disturbing acoustical noise of echo planar imaging (EPI). A sparse acquisition technique was used in which the delayed hemodynamic response was imaged at discrete sampling time‐points after a brief auditory stimulus. Long repetition times (10 heartbeats (HBs)) were used to avoid interactions between the activation due to the sound stimulation and scanner noise. In addition, only a single slice was acquired, to ensure that the scanner noise was minimal in duration and intensity. The image acquisition was triggered by the HB to prevent artifacts from cardiac‐related brainstem motion. An image was acquired every 10th HB. Significant hemodynamic BOLD time‐course responses were measured from the primary and secondary auditory cortices, as well as the inferior colliculi in the brainstem. No systematic differences were found between the cerebral cortex and the brainstem in terms of activation amplitude or in onset time of the hemodynamic response. Apparently, the slow dynamic nature of the BOLD response signal is similar across spatially separated auditory brain regions, suggesting a corresponding design of vessels and capillaries. Magn Reson Med 47:90–96, 2002. © 2002 Wiley‐Liss, Inc.
Impact of navigator timing on free‐breathing submillimeter 3D coronary magnetic resonance angiography
Authors: Spuentrup Elmar , Manning Warren J. , Botnar René M. , Kissinger Kraig V. , Stuber Matthias 
Published: September 2002

AbstractThe purpose of this study was to investigate the impact of navigator timing on image quality in navigator‐gated and real‐time motion‐corrected, free‐breathing, three‐dimensional (3D) coronary MR angiography (MRA) with submillimeter spatial image resolution. Both phantom and in vivo investigations were performed. 3D coronary MRA with real‐time navigator technology was applied using variable navigator time delays (time delay between the navigator and imaging sequences) and varying spatial resolutions. Quantitative objective and subjective image quality parameters were assessed. For high‐resolution imaging, reduced image quality was found as a function of increasing navigator time delay. Lower spatial resolution coronary MRA showed only minor sensitivity to navigator timing. These findings were consistent among volunteers and phantom experiments. In conclusion, for submillimeter navigator‐gated and real‐time motion‐corrected 3D coronary MRA, shortening the time delay between the navigator and the imaging portion of the sequence becomes increasingly important for improved spatial resolution. Magn Reson Med 47:196–201, 2002. © 2002 Wiley‐Liss, Inc.