bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of lack of Interleukin‐4, Interleukin‐12, Interleukin‐18, or the Interferon‐γ receptor on virus replication, cytokine response, and lung pathology during respiratory syncytial virus infection in mice
Authors: Boelen Anita , Kwakkel Joan , Barends Marion , de Rond Lia , Dormans Jan , Kimman Tjeerd 
Published: August 2002

AbstractRSV is an important cause of bronchiolitis in infants. Immunopathology may play a role in RSV‐induced bronchiolitis and severe RSV‐induced disease has been associated with a Th2 type immune response. The aim of the study was to identify cytokine pathways that are crucial in influencing RSV‐induced disease. For that purpose we inoculated IFNγR−/−, IL‐12−/−, IL‐18−/−, or IL‐4−/− mice with RSV. We observed that an RSV infection resulted in a predominant Th1 cytokine response associated with slight bronchiolitis and alveolitis. Pulmonary histopathology was only aggravated in IFN R−/− mice, characterised by eosinophilic influx around the bronchioles. Despite subtle changes in cytokine expression, no differences in histopathology were observed in IL‐12−/− and IL‐18−/− mice. Deficiency of IL‐4 has no effect on RSV‐induced Th1 cytokines and pulmonary histopathology. IFNγ‐receptor deficiency during primary RSV infection resulted in a disturbed Th1 response based on increased IL‐4, IL‐5, and IL‐13 expression and the presence of eosinophils in the lungs. It is concluded that IFNγ signalling is required for a pronounced Th1 response to RSV while IL‐12 and IL‐18 are not. A shift in the balance between Th1 and Th2 towards a Th2 response induced by missing IFNγ signalling leads to aggravated pulmonary pathology. This is not caused by enhanced viral load. J. Med. Virol. 66:552–560, 2002. © 2002 Wiley‐Liss, Inc.
On oscillation‐based test structures of active RC filters
Authors: Zarnik Marina Santo , Novak Franc 
Published: August 2002

AbstractThe recently proposed oscillation‐based test structures of active RC filters assume ideal opamps and test switches. In this letter, feasibility case study of the oscillation‐based test structure of the resonant bandpass filter is presented in which non‐ideal characteristics of the employed opamps and MOS switches are considered. Based on the dominant pole model for the opamps, we derive expression for the minimum value of the resistance required to put the filter stage into oscillation and expression for the frequency of the undamped pole. Derived expressions describe the conditions for the implementation of the oscillation‐based test in practice. Copyright © 2001 John Wiley & Sons, Ltd.
Defective neuronal sprouting by human apolipoprotein E4 is a gain‐of‐negative function
Authors: Teter B. , Xu P‐T. , Gilbert J.R. , Roses A.D. , Galasko D. , Cole G.M. 
Published: August 2002

AbstractThe apolipoprotein E (apoE) epsilon 4 allele (apoE4) is a major risk factor for neurodegenerative conditions, including Alzheimer's disease (AD). A role for apoE in regeneration of synaptic circuitry after neural injury has been shown in several in vitro studies in which apoE3 supports neuronal sprouting better than apoE4. We evaluated sprouting in an in vitro mouse organotypic hippocampal slice culture system derived from transgenic mice expressing apoE3 or apoE4, in which apoE‐dependent granule cell mossy fiber sprouting in the presence of apoE4 is only 51% of the level of apoE3. Sprouting supported by apoE4 had a dose response opposite that by supported by apoE3: although increasing E3 expression increased sprouting, increasing E4 expression decreased sprouting, suggesting that the defect in E4 in supporting neuronal sprouting is a gain‐of‐negative activity. These results may have important pharmacogenomic implications for AD therapies that modulate apoE expression levels. © 2002 Wiley‐Liss, Inc.
Effect of amyloid β‐peptide on permeability transition pore: A comparative study
Authors: Moreira Paula I. , Santos Maria S. , Moreno António , Rego A. Cristina , Oliveira Catarina 
Published: August 2002

AbstractA potentially central factor in neurodegeneration is the permeability transition pore (PTP). Because of the tissue‐specific differences in pore properties, we directly compared isolated brain and liver mitochondria responses to the neurotoxic Aβ peptides. For this purpose, the following parameters were examined: mitochondrial membrane potential (ΔΨm), respiration, swelling, ultrastructural morphology, and content of cytochrome c. Both peptides, Aβ25–35 (50 μM) and Aβ1–40 (2 μM), had a similar toxicity, exacerbating the effects of Ca2+, although, per se, they did not induce (PTP). In liver mitochondria, Aβ led to a drop in ΔΨm and potentiated matrix swelling and disruption induced by Ca2+. In contrast, brain mitochondria, exposed to the same conditions, demonstrated a higher capacity to accumulate Ca2+ before the ΔΨm drop and a slight increase of mitochondrial swelling compared with liver mitochondria. Furthermore, mitochondrial respiratory state 3 was depressed in the presence of Aβ, whereas state 4 was unaltered, resulting in an uncoupling of respiration. In both types of mitochondria, Aβ did not affect the content of cytochrome c. The ΔΨm drop was reversed when Ca2+ was removed by EGTA or when ADP plus oligomycin was present. Pretreatment with cyclosporin A or ADP plus oligomycin prevented the deleterious effects promoted by Aβ and/or Ca2+. It can be concluded that brain and liver mitochondria show a different susceptibility to the deleterious effect of Aβ peptide, brain mitochondria being more resistant to the potentiation by Aβ of Ca2+‐induced PTP. © 2002 Wiley‐Liss, Inc.
c‐Jun regulation in rat neonatal motoneurons postaxotomy
Authors: Casanovas Anna , Ribera Joan , Hager Gerhard , Kreutzberg Georg W. , Esquerda Josep E. 
Published: August 2002

AbstractMotoneurons respond to peripheral nerve transection by either regenerative or degenerative events depending on their state of maturation. Since the expression of c‐Jun has been involved in the early signalling of the regenerative process that follows nerve transection in adults, we have investigated c‐Jun on rat neonatal axotomized motoneurons during the period in which neuronal death is induced. Changes in levels of c‐Jun protein and its mRNA were determined by means of quantitative immunocytochemistry and in situ hybridization. Three hours after nerve transection performed on postnatal day (P)3, c‐Jun protein and mRNA is induced in axotomized spinal cord motoneurons, and high levels were reached between 1 and 10 days after. This response is associated with a detectable c‐Jun activation by phosphorylation on serine 63. No changes were found in the levels of activating transcription factor ‐2. Most of dying motoneurons were not labelled by either a specific c‐Jun antibody or a c‐jun mRNA probe. However, dying motoneurons were specifically stained by a polyclonal anti c‐Jun antibody, indicating that some c‐Jun antibodies react with unknown epitopes, probably distinct from c‐Jun p39, that are specifically associated with apoptosis. J. Neurosci. Res. 63:469–479, 2001. © 2001 Wiley‐Liss, Inc.
Differential DM20 mRNA expression distinguishes two distinct patterns of spontaneous recovery from murine autoimmune encephalomyelitis
Authors: Mathisen Peter M. , Kawczak Julie A. , Yu Min , Johnson Justin M. , Tuohy Vincent K. 
Published: August 2002

AbstractExperimental autoimmune encephalomyelitis (EAE) is an animal model for multiple sclerosis (MS) mediated by T cells responding to CNS myelin proteins. Immunization of SWXJ mice with the immunodominant p139‐151 peptide of myelin proteolipid protein (PLP) results in a relapsing‐remitting pattern of EAE characterized by incomplete remyelination during clinical recovery. In the present study we observed two distinct clinical patterns of spontaneous remission during recovery from EAE, viz., sustained remission involving continuous neurologic improvement and aborted remission involving modest transient clinical improvement. We hypothesized that the ability to recover from autoimmune demyelination was directly linked to remyelination events that recapitulated developmental processes. Quantitative immunocytochemistry of CNS tissue showed decreased demyelination in mice undergoing sustained remission compared to mice undergoing aborted remission. Quantitative RT‐PCR analysis showed elevated expression of DM20, the developmental isoform of PLP, in CNS tissue from mice undergoing sustained remission compared to mice undergoing aborted recovery. Moreover, DM20 expression was similarly elevated in CNS tissue from mice undergoing sustained recovery from EAE relapse. Our data indicate that expression of the developmental DM20 isoform of PLP is intimately associated with decreased demyelination and sustained clinical recovery from EAE. Thus, DM20 gene expression may provide an appropriate molecular target for promoting CNS remyelination and may serve as a useful marker for predicting clinical outcome and assessing the effectiveness of strategies aimed at promoting CNS tissue repair during autoimmune demyelinating disease. J. Neurosci. Res. 64:542–551, 2001. © 2001 Wiley‐Liss, Inc.
Dorsal root ganglia neurite extension is inhibited by mechanical and chondroitin sulfate‐rich interfaces
Authors: Yu Xiaojun , Bellamkonda Ravi V. 
Published: August 2002

AbstractGlial scar formation plays a critical role in the regenerative failure in the central nervous system of adult mammals through the formation of mechanical or biochemical barriers as a result of its molecular composition. In this study, we report an in vitro model to study growth‐cone behavior at controlled 3D interfaces using layered agarose hydrogels. The behavior of growth cones from embryonic day 9 (E9) chick dorsal root ganglia (DRGs) at interfaces that were mismatched in terms of their elasticity or chondroitin sulfate content was quantitatively determined. A mechanical barrier formed by the elasticity mismatch of layered agarose gels greatly influenced the ability of neurites from E9 DRGs to cross the 3D interface. To form chondroitin sulfate‐rich interfaces, chondroitin sulfate B was covalently coupled to agarose hydrogel. Compared with unmodified agarose gels, the presence of CS‐B‐modified agarose gels at the interface significantly inhibited E9 DRGs neurites. After treatment of CS‐B‐modified agarose gels with chondroitinase ABC, the inhibitory effects of CS‐B at the interface were significantly decreased. The effect of doping CS‐B gels with laminin 1 (LN‐1)‐coupled agarose gels was investigated as a potential strategy to overcome inhibitory interfaces. When CS‐B agarose gels were doped with LN‐1‐coupled agarose gels, DRG neurite's ability to cross 3D interfaces was significantly enhanced compared with that of non‐LN‐1‐containing interfaces presenting equivalent CS‐B. Our in vitro model may be used to study the influence of individual components of glial scar on inhibition as well as to design strategies to overcome this inhibition. J. Neurosci. Res. 66:303–310, 2001. © 2001 Wiley‐Liss, Inc.
Sex proportion and performance evaluation among high‐ranking military officers
Authors: Pazy Asya , Oron Israela 
Published: August 2002

AbstractThis field study examined the relationships between sex proportion and performance evaluation among 3014 high‐ranking officers (Majors and Lieutenant Colonels) in the Israeli Defense Forces. Women's performance was rated lower than that of men when the women were token members of their units. However, the performance of women was rated higher than that of men when they constituted a higher proportion. Men's overall performance did not co‐vary with proportion. In addition, the interaction of sex with proportion had a significant effect on the dimensions of Operational and Analytic Competence. The pattern of findings supports Kanter's framework of skewed and tilted groups. Copyright © 2001 John Wiley & Sons, Ltd.
A tree‐ring reconstruction of past precipitation for Baja California Sur, Mexico
Authors: Díaz Sara C. , Touchan Ramzi , Swetnam Thomas W. 
Published: August 2002

AbstractThere is great interest in the climatic variability of Baja California and the Sea of Cortes, but long‐term information is limited because instrumental climate records begin in the 1940s or 1960s. The first tree‐ring chronology of Pinus lagunae was developed from the southern part of the Baja California Peninsula and the chronology is used to reconstruct the history of precipitation variations. A September–July precipitation reconstruction is developed for the period AD 1862–1996 (R=0.71, p<0.0001, n=56, cross‐validation=0.68). This reconstruction is used to assess precipitation variability over the past two centuries, including the relationship with ENSO events. The reconstructed precipitation series indicates a long drought period from 1939 to 1958. It also shows that 1983, one of the strongest El Niño events of the 20th century, is the wettest year. El Niño events during the 20th century are associated with above‐normal precipitation, whereas La Niña events are characterized by below‐normal precipitation. Four of the most extreme wet years occurred in association with these warm events (1905, 1912, 1919 and 1983). Seventy‐one percent of La Niña events are characterized by below‐normal precipitation. Sixty‐two percent of El Niño events are characterized by above‐normal precipitation. Tree‐ring growth of P. lagunae is most strongly correlated with winter precipitation in Sonora, Sinaloa and southern Baja California Sur. Precipitation data from meteorological stations in northern Baja California do not correlate well with the tree‐ring chronology because this zone has a Mediterranean climate, which differs from the rest of northwest Mexico. Copyright © 2001 Royal Meteorological Society
Extreme daily precipitation in Western Europe with climate change at appropriate spatial scales
Authors: Booij M. J. 
Published: August 2002

AbstractExtreme daily precipitation for the current and changed climate at appropriate spatial scales is assessed. This is done in the context of the impact of climate change on flooding in the river Meuse in Western Europe. The objective is achieved by determining and comparing extreme precipitation from stations, reanalysis projects, global climate models and regional climate models. An extreme value reduction methodology based on extreme precipitation correlation structure and surface area is used to deal with the transformation between different spatial scales. It appeared that return values are simulated quite well by the regional climate models and CSIRO9, but are underestimated by the reanalyses and overestimated by CGCM1 and HadCM3. The models simulated an average increase in extreme precipitation with climate change of about 18%, which is in the same range as the average model error and intermodel differences. The appropriate spatial scale for representing extreme precipitation was estimated at 20 km, when the bias permitted in the estimation of extreme precipitation is set at 10%. Downscaling modelled extreme precipitation to this appropriate scale results in considerable differences between reanalysis and GCM scale and appropriate scale return values. It is therefore obvious that return values at these appropriate scales should be used instead of at their original scales. Copyright © 2002 Royal Meteorological Society.
Prospects for seasonal forecasting of summer drought and low river flow anomalies in England and Wales
Authors: Wedgbrow C. S. , Wilby R. L. , Fox H. R. , O'Hare G. 
Published: August 2002

AbstractFuture climate change scenarios suggest enhanced temporal and spatial gradients in water resources across the UK. Provision of seasonal forecast statistics for surface climate variables could alleviate some negative effects of climate change on water resource infrastructure. This paper presents a preliminary investigation of spatial and temporal relationships between large‐scale North Atlantic climatic indices, drought severity and river flow anomalies in England and Wales. Potentially useful predictive relationships are explored between winter indices of the Polar–Eurasian (POL) teleconnection pattern, the North Atlantic oscillation (NAO), North Atlantic sea surface temperature anomalies (SSTAs), and the summer Palmer drought severity index (PDSI) and reconstructed river flows in England and Wales. Correlation analyses, coherence testing and an index of forecast potential, demonstrate that preceding winter values of the POL index, SSTA (and to a lesser extent the NAO), provide indications of summer and early autumn drought severity and river flow anomalies in parts of northwest, southwest and southeast England. Correlation analyses demonstrate that positive winter anomalies of T1, POL index and NAO index are associated with negative PDSI (i.e. drought) across eastern parts of the British Isles in summer (r < 0.51). Coherence tests show that a positive winter SSTA (1871–1995) and POL index (1950–95) have preceded below‐average summer river flows in the northwest and southwest of England and Wales in 70 to 100% of summers. The same rivers have also experienced below‐average flows during autumn following negative winter phases of the NAO index in 64 to 93% of summers (1865–1995). Possible explanations for the predictor–predictand relationships are considered, including the ‘memory’ of groundwater, and ocean–atmosphere coupling, and regional manifestations of synoptic rainfall processes. However, further research is necessary to increase the number of years and predictor variables from which it is possible to derive rules that may be useful for forecasting. Copyright © 2002 Royal Meteorological Society.
Droughts and extreme events in regional daily Italian precipitation series
Authors: Brunetti Michele , Maugeri Maurizio , Nanni Teresa , Navarra Antonio 
Published: August 2002

AbstractThis paper proposes a methodology to study daily precipitation series that include a significant proportion of missing data, without resorting to completion methods based on randomly generated numbers. It is applied to a data set consisting of 75 station records (1951–2000) covering the Italian territory. They are clustered by principal component analysis into six regions: the north‐west, the northern part of the north‐east, the southern part of the north‐east, the centre, the south and the islands (i.e. Sicily and Sardinia). Complete annual and seasonal regional average series are obtained from the incomplete station records, and analysed for droughts and extreme precipitation events. Droughts are identified by means of two indicators: the longest dry period and the proportion of dry days. The most remarkable result is a systematic increase in winter droughts over all of Italy, especially in the north, due mainly to the very dry 1987–93 period. Extreme events are analysed considering 5 day regional totals. In this case, however, an attempt to search for a statistically significant trend is not successful because of the scarcity of events in such a short period. The reliability of the regional series is checked by computing some basic statistics concerning total precipitation, rainy days and precipitation intensity and comparing them with the same statistics computed for regional series obtained by station records completed with methods based on random number generators. Copyright © 2002 Royal Meteorological Society.
Identification and differentiation of ancient and modern European porcelains by Raman macro‐ and micro‐spectroscopy†
Authors: Colomban Philippe , Treppoz Françoise 
Published: August 2002

AbstractSelected porcelain representative of the different production technologies used from the eighteenth to the twentieth century at the French Royal Manufacture, which became The Imperial Manufacture and now the Manufacture Nationale de Sèvres, were studied by non‐destructive Raman macro‐ and/or micro‐spectroscopy: French soft paste (‘pâte tendre’ or ‘frit ware’), English‐like (bone China), the latest soft pastes made from glass (silica‐rich soft paste, Vögt soft paste), and ancient hard (PDA) and new hard (PDN) pastes. Analyses were made directly on the glazed and unglazed regions of the bodies. The presence of a strong β‐wollastonite and/or tricalcium phosphate peak makes it easy to differentiate a soft‐paste body from a hard‐paste body on Raman spectra. The different components of the spectra also allow the identification of the different types of glaze (with stannic, lead or boron oxide or feldspars as the main fluxing materials). Numerical analysis (2D correlation method) was applied to identify the glaze and highlight the relationship between different samples. Copyright © 2001 John Wiley & Sons, Ltd.
Raman intensity and conjugation with participation of ordinary σ‐bonds
Authors: Leites Larissa A. , Bukalov Sergey S. 
Published: August 2002

AbstractThis review covers Raman investigations over a wide range, but focused on the problem of conjugation with participation of ordinary σ‐bonds. The results show that σ–σ conjugation in a novel class of polymers, polydiakylmetallanes of the type [R2M]n, M = Si, Ge, Sn, studied recently, and σ–π conjugation in some organometallic compounds of Si, Ge and Sn, studied long ago, both manifest themselves in the Raman spectra qualitatively in a similar way to π–π conjugation in polyenes and lead to a significant increase in intensity of the lines, corresponding to stretching vibrations of the conjugated bonds, the effect being strongly dependent on mutual orientation of the latter. It was found that pre‐resonant enhancement of some lines in the Raman spectra of polymetallanes is exhibited only by macromolecules having a planar zig‐zag all‐anti conformation of the backbone. Less ordered conformations do not show this effect, in spite of the proximity of the position of their lowest energy electronic absorption band νe to the exciting line ν. Thus, proximity of νe to ν in the resonance denominator is shown to be necessary but not sufficient for the pre‐resonant increase in Raman intensity to occur. These experimental findings are in good accord with Shorygin's general views on the conjugation phenomenon and with his semi‐classical treatment of the Raman intensity problem, confirming an important role of the derivative ∂νe/∂Qi that reflects the specificity of molecular electronic structure. Copyright © 2001 John Wiley & Sons, Ltd.
Raman scattering properties of GaN thin films grown on sapphire under visible and ultraviolet excitation
Authors: Feng Z. C. , Wang W. , Chua S. J. , Zhang P. X. , Williams K. P. J. , Pitt G. D. 
Published: August 2002

AbstractRaman scattering properties from various GaN thin films grown on sapphire by metalorganic chemical vapor deposition were studied. Visible micro‐Raman measurements show different mode behaviors with different laser incidence configurations. Raman lineshape analyses through two sets of equations led to the monitoring of the sample quality and stress and the optical determination of electrical properties of GaN films. An approximate 3 cm−1shift in theE1(LO) mode wavenumber is observed across the GaN film from the sapphire/GaN interface to the GaN surface, indicating the spatial variation of strains along the film growth direction within a few microns thickness range. Combined Raman and PL spectra were obtained under UV excitation, and interesting high‐order resonance Raman features were observed using a sensitive UV–Raman–photoluminescence microscope. A new way to characterize p‐type GaN is introduced. Copyright © 2001 John Wiley & Sons, Ltd.