bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glutamate transporter EAAC1 is expressed on Müller cells of lower vertebrate retinas
Authors: Zhao Jing‐Wei , Yang Xiong‐Li 
Published: August 2002

AbstractThe expression of glutamate transporter EAAC1 was investigated in carp and bullfrog retinas using Western blotting, immunofluorescence double labeling and confocal laser scanning microscopic techniques. In addition to a variety of retinal neurons, radially oriented elements spanning the whole neural retinas of carp and bullfrog were also EAAC1‐immunoreactive, and EAAC1 was found to be predominantly on the cell membrane. Virtually all EAAC1‐labeled radial elements were immunopositive to glial fibrillary acidic protein (GFAP), a specific marker for retinal Müller cells of carp and bullfrog, indicating that they were Müller cells. This finding suggests that EAAC1, which has been thought to be an exclusively neuronal type, may be a glial transporter as well. EAAC1 of Müller cells may play an important modulatory role in the retina by making contributions to glutamate homeostasis. J. Neurosci. Res. 66:89–95, 2001. © 2001 Wiley‐Liss, Inc.
Evidence for a ligand‐specific signaling through GFRα‐1, but not GFRα‐2, in the absence of Ret
Authors: Pezeshki Gita , Franke Barbara , Engele Jürgen 
Published: August 2002

AbstractGlial cell line‐derived neurotrophic factor (GDNF) and neurturin (NTN) are two homologeous proteins that have been recognized as potent survival factors for distinct neuronal populations. GDNF and NTN act through a two‐component receptor system consisting of the ligand‐specific binding subunits GDNF family receptor (GFR)α‐1 and GFRα‐2 and the common transducing subunit c‐Ret. In addition, it has been demonstrated that GDNF can signal through GFRα‐1 in the absence of c‐Ret. In the present study, we sought to determine whether a similar c‐Ret‐independent signaling applies for GFRα‐2. In addition, we have characterized the ligand specificity of the c‐Ret‐independent action of GFRαs. To establish an assay system for these studies, several neural cell lines were screened for the presence of GDNF and NTN receptor subunits by RT‐PCR and immunoblot analysis. c‐Ret expression was detectable only in Neuro2A cells, which did not express GFRα‐1 or GFRα‐2. The neuronal cell line LS expressed GFRα‐2, and the glial cell line Mes42 expressed GFRα‐1, whereas the neuronal cell line B104 expressed both GFRα‐1 and GFRα‐2. Stimulation of B104 and Mes42 cells with GDNF, but not with NTN, for 10 min resulted in CREB phosphorylation. In apparent contrast, neither NTN nor GDNF promoted CREB activation in LS and Neuro2A cells. Moreover, exposure of LS cells to NTN or GDNF also failed to activate AKT and ERK. Together these findings provide evidence that, in contrast to GFRα‐1, GFRα‐2 fails to signal in the absence of c‐Ret. In addition, these observations reveal that c‐Ret‐independent signaling of GFRα‐1 is ligand‐ specific and occurs only with GDNF. J. Neurosci. Res. 66:390–395, 2001. © 2001 Wiley‐Liss, Inc.
FFT analysis on NDVI annual cycle and climatic regionality in Northeast Brazil
Authors: I. Negrón Juárez Robinson , T. Liu William 
Published: August 2002

AbstractBy considering that the climate of Northeast Brazil (NEB) has distinct wet and dry seasons, the mixed radix fast Fourier transform (mrFFT) algorithm, developed at the National Aerospace Centre of the Netherlands, was applied to a monthly Normalized Difference Vegetation Index (NDVI) time series from July 1981 to June 1993, to generate phase, amplitude and mean NDVI data using a 1‐year frequency in order to improve the analysis of its spatial variation.The NDVI mean values varied from >0.7, which occurred in northwest and southeast regions, to <0.3 in the northeast and 0.4 in the southwest regions of the NEB. The 90° phase month at its maximum amplitude occurred in August and was observed in both southeastern and northwestern coasts, located at 10.5°S–37.5°W and 4°S–46°W, respectively. It changed rapidly from August, June to May, moved inland and changed gradually from May through to April and from March to February, then moved towards the centre Dry Polygon area. Then it changed gradually from February to January and ended up in December, and moved further southwards. The annual cycle amplitude varied from <0.075 in northwest and southeast regions to >0.25 in the northeast region. By using spatial variations of phase, amplitude and mean NDVI values, 15 climate types were delineated for the NEB.The spatial distribution of climate types in the NEB delineated by the NDVI FFT analysis agreed mostly with the climatic types presented by Hargreaves (Precipitation dependability and potentials for agricultural production in Northeast Brazil. Empresa Brasileira de Pesquisa Agropecuária‐EMBRAPA, Brazil, 1974), except regions with higher spatial variability and limited surface meteorological data. Among the three components: phase, amplitude and mean NDVI, the phase image, informing the initiation and duration of rainy season, was the most important component for climate‐type delineation. Nevertheless, while the extreme values of amplitude, inferring a high wet–dry rainfall regime contrast, and mean NDVI, inferring annual rainfall total, occurred in the same phase area, amplitude and mean NDVI images were used for further delineation. It is concluded that the application of the mrFFT algorithm to NDVI time series analysis is an effective method for identifying vegetation phenology and hence to delineate the transit spatial change of climate types. Our further study is to construct and validate the alternative El Niño–Southern Oscillation (ENSO) drought onset model for each of the 15 climate types delineated for the NEB. Copyright © 2001 Royal Meteorological Society
Reconstruction of the North Atlantic Oscillation, 1429–1983
Authors: Glueck Mary F. , Stockton Charles W. 
Published: August 2002

AbstractThe North Atlantic Oscillation (NAO) is considered to be the dominant mode of winter atmospheric variability in the Northern Hemisphere (Barnston AG, Livezey RE. 1987. Classification, seasonality and persistence of low frequency atmospheric circulation patterns. Monthly Weather Review 115: 1083–1126), especially in the North Atlantic region. A better understanding of its recent variability in the context of pre‐instrumental period variations is critical for prediction purposes. A 555‐year (1429–1983) multi‐proxy reconstruction of the cool season NAO, calibrated against the Lisbon–Iceland (LISJHI) NAO, is presented. Predictor variables include tree‐ring chronologies from Morocco and Finland, GISP2 δ18O annual series, and a GISP2 snow accumulation record. Although the reconstructed values are generally lower than the instrumental values during the calibration period (1863–1983), the final reconstruction does capture the low frequency of the instrumental NAO. The reconstruction compares favourably with existing shorter NAO reconstructions and with the instrumental NAO. The variability in the reconstructed NAO is also discussed within the context of lengthy regional climate records. Results suggest that the occurrence and length of the recent persistently high phase of the NAO are not unusual over the 555‐year period of time, but that the magnitude of some of the instrumental values may, in fact, be unique. Copyright © 2001 Royal Meteorological Society
Dinoflagellate cyst assemblages as tracers of sea‐surface conditions in the northern North Atlantic, Arctic and sub‐Arctic seas: the new ‘n = 677’ data base and its application for quantitative palaeoceanographic reconstruction
Authors: Vernal Anne de , Henry Maryse , Matthiessen Jens , Mudie Peta J. , Rochon André , Boessenkool Karin P. , Eynaud Frédérique , GrØsfjeld Kari , Guiot Joël , Hamel Dominique , Harland Rex , Head Martin J. , Kunz‐Pirrung Martina , Levac Elisabeth , Loucheur Virginie , Peyron Odile , Pospelova Vera , Radi Taoufik , Turon Jean‐Louis , Voronina Elena 
Published: August 2002

AbstractThe distribution of dinoflagellate cyst (dinocyst) assemblages in surface sediment samples from 677 sites of the northern North Atlantic, Arctic and sub‐Arctic seas is discussed with emphasis on the relationships with sea‐surface parameters, including sea‐ice cover, salinity and temperature of the coldest and warmest months. Difficulties in developing a circum‐Arctic data base include the morphological variation within taxa (e.g. Operculodinium centrocarpum, Islandinium? cezare and Polykrikos sp.), which probably relate to phenotypic adaptations to cold and/or low salinity environments. Sparse hydrographical data, together with large interannual variations of temperature and salinity in surface waters of Arctic seas constitute additional limitations. Nevertheless, the use of the best‐analogue technique with this new dinocyst data base including 677 samples permits quantitative reconstruction of sea‐surface conditions at the scale of the northern North Atlantic and the Arctic domain. The error of prediction calculated from modern assemblages is ±1.3 °C and ±1.8 °C for the temperature of February and August, respectively, ±1.8 for the salinity, and ±1.5 months yr−1 for the sea‐ice cover. Application to late Quaternary sequences from the western and eastern subpolar North Atlantic (Labrador Sea and Barents Sea) provide reconstructions compatible with those obtained using the previous dinocyst data base (n = 371), which mainly included modern data from the northern North Atlantic. Copyright © 2001 John Wiley & Sons, Ltd.
Infrared and Raman spectra of Hg2MoO4 and Hg2WO4
Authors: Baran Enrique J. , Mormann Thomas J. , Göcke Hans‐J. , Jeitschko Wolfgang 
Published: August 2002

AbstractThe Fourier transform infrared and Raman spectra of the low‐temperature form of mercury(I) molybdate and the corresponding tungstate were recorded and are discussed on the basis of their structural characteristics, with the aid of factor group analysis. Copyright © 2001 John Wiley & Sons, Ltd.
A review on linear and non‐linear resonance Raman spectroscopy of the conjugated system polydiacetylene
Authors: Materny A. , Chen T. , Vierheilig A. , Kiefer W. 
Published: August 2002

AbstractWe review resonance Raman investigations of the linear conjugated π‐electron system of polydiacetylenes embedded in single‐crystalline monomer matrices. Absorption, luminescence, resonance Raman and resonance CARS spectroscopy were used to investigate vibronic properties of the polymers. As an example, we discuss the theoretical model applied for the simulation of the resonance Raman line and excitation profiles obtained from the polymer chains in FBS, TS/FBS and TS6 diacetylene single crystals. The theory is based on a Franck– Condon model, which considers a chain length dependence. The electronic transition energies and matrix elements were calculated by means of an LCAO MO (linear combination of atomic orbitals molecular orbital) calculation in the Hückel approach. An interaction between ensemble and intramolecular properties due to defects can be shown. Besides the well known polymer absorption, the partially polymerized single crystals of the diacetylenes under investigation show blue‐shifted absorption bands in sharply separated crystal areas. The spectroscopic investigations of this chromism revealed that most probably growth defects in {111} crystal growth sectors influence the side‐group geometry of the polymer chains. Using femtosecond time‐resolved CARS spectroscopy, the dynamics of the vibrational excitation in the electronic ground and excited states can be investigated. Here, we report the controlled selective excitation of the polymers. We used a CARS scheme where the difference of pump and Stokes laser wavelengths is chosen to achieve resonance with several chain modes of the polydiacetylenes. By varying the timing and the phases of the femtosecond laser pulses, the timing and the intensity of these modes can be strongly influenced. Copyright © 2001 John Wiley & Sons, Ltd.
Study of the segregation process in GaAs/AlAs superlattices using Raman spectroscopy
Authors: Zanelato G. , Pusep Yu. A. , Galzerani J. C. , Lubyshev D. I. , González‐Borrero P. P. 
Published: August 2002

AbstractA Raman scattering study of cation segregation in GaAs/AlAs ultrathin‐layer superlattices grown with different temperatures and As pressures is reported. The optical confined modes of the samples were measured. The kinetic segregation model was modified in order to allow the calculation of the compositional profiles of the samples. After utilizing the Raman wavenumbers as references to adjust the calculated values by the next‐nearest‐neighbor linear chain model, it was possible to determine the parameters characterizing the segregation. It is shown that an increase in the pressure of As results in a more abrupt compositional profile, equivalent to the decrease in the growth temperature. Copyright © 2001 John Wiley & Sons, Ltd.
Trypsin inhibitor activity in vegetative tissue of sweet potato plants and its response to heat treatment
Authors: Zhang Zhitian , Corke Harold 
Published: August 2002

AbstractTrypsin inhibitor activity (TIA) and crude protein content of seven genotypes of sweet potato were investigated. There was considerable genotypic variation in TIA, with a four‐ to fivefold range in roots and a threefold range in stems. The mean TIA in stems at harvest time was 36% of that in roots, whilst the mean TIA in leaves was only 17% of that in roots. The TIA level in roots was correlated with that in stems (r  = 0.83, p  = 0.02) and leaves (r  = 0.70, p  = 0.08). In most genotypes the TIA level in vine‐tips was low during the early growth stage, increased from day 30 to day 110 after transplanting, then remained constant in subsequent growth stages. However, in genotype Guang 70‐9, vine‐tips had a high level of TIA at all growth stages. Sweet potato green tissue contained three‐ to fivefold more crude protein than roots. No correlation between TIA and crude protein in sweet potato roots was found across genotypes, but TIA was significantly correlated with crude protein content (r  = 0.73, p  = 0.06) in sweet potato vine‐tips. Moist heat treatment (MHT) was found to be effective in eliminating TIA in sweet potato. Most TIA in sweet potato green tissue and roots was eliminated by MHT at ≥80 °C, but heat stability was dependent on genotype. Guang 70‐9 had relatively highly heat‐stable trypsin inhibitor. The results suggested that screening for genotypes with high protein content and low TIA and use of an appropriate processing method could improve the utilisation of sweet potato for both human food and animal feed.© 2001 Society of Chemical Industry
Effect of the addition of calcium hydroxide on some characteristics of extruded products from blue maize (Zea mays L) using response surface methodology
Authors: Zazueta‐Morales José J , Martínez‐Bustos Fernando , Jacobo‐Valenzuela Noelia , Ordorica‐Falomir César , Paredes‐López Octavio 
Published: August 2002

AbstractThe aim of this research was to study the effects of calcium hydroxide (0–0.2%) and screw speed (100–180 rpm) on the expansion index (EI), bulk density (BD), penetration force (PF) and specific mechanical energy (SME) values of blue maize meal extrudates. Blue maize meal was extruded using a commercial extruder (Brabender 20DN/8‐235‐00) with a compression screw ratio of 3:1. A second‐order, central composite experimental design was used. It was found that the EI and SME values decreased and the BD and PF values increased when the calcium hydroxide concentration was increased. The screw speed had a significant effect only on the SME and PF values. Quadratic model fitness was shown for all responses, with values of R2 > 0.74, p of F (model) <0.01 and variability coefficient <13.3% (except for PF, 29.18%), and for almost all cases there was no lack of fit (p > 0.055). Calcium hydroxide concentration showed good correlation (p < 0.01) with EI (r  = −0.81), PF (r  = 0.60), SME (r  = −0.76) and BD (r  = 0.83). However, screw speed was marginally or not correlated (r < 0.36, p > 0.14) with the responses. The results suggest that it is possible to produce appropriate extruded products from blue maize fortified with calcium in an optimised calcium hydroxide concentration and screw speed range of 0.02–0.078% and 117–180 rpm respectively.© 2001 Society of Chemical Industry
Activation of matrix metalloproteinase‐2 is correlated with invasiveness in thymic epithelial tumors
Authors: Kondo Kazuya , Kinoshita Hidetaka , Ishikura Hisashi , Miyoshi Takanori , Hirose Toshiyuki , Matsumori Yasumichi , Monden Yasumasa 
Published: August 2002

AbstractBackground and ObjectsMatrix degradation, which is a critical event in the process of tumor invasion and metastasis, is considered to be caused by the action of proteolytic enzymes.MethodsWe examined the gelatinolytic activity of matrix metalloproteinase (MMP)‐9, and the activity of active and inactive forms of MMP‐2 in five thymi, five noninvasive thymomas, eight invasive thymomas, and five thymic carcinomas by quantitative gelatinolytic zymography.ResultsThe gelatinolytic activity of active MMP‐2 in five thymi was zero. The mean gelatinolytic activity of active MMP‐2 was 0.020 ± 0.015 in noninvasive thymoma, 0.084 ± 0.098 in invasive thymoma and 0.246 ± 0.194 in thymic carcinoma. The gelatinolytic activity of active MMP‐2 correlated with the invasiveness of thymic epithelial tumors (Spearman rank correlation: r‐value = 0.532). The gelatinolytic activity of active MMP‐2 in three thymoma cases with microscopic capsular invasion was the same as that of noninvasive thymoma. When thymoma cases showing microscopic capsular invasion were classified into the “macroscopically noninvasive thymoma” group, the gelatinolytic activity of active MMP‐2 correlated with the invasiveness of thymic epithelial tumors (Spearman rank correlation: r‐value = 0.621).ConclusionsThe gelatinolytic activity of active MMP‐2 significantly correlated with the invasiveness in thymic epithelial tumors. J. Surg. Oncol. 2001;76:169–175. © 2001 Wiley‐Liss, Inc.
A new model to assist in planning for sustainable cultural heritage tourism
Authors: du Cros Hilary 
Published: August 2002

AbstractA natural link exists between tourism and cultural heritage management, yet little discourse and debate occurs between them on the sustainability of heritage tourism. What also is missing is a process whereby elements of both areas can be included in the identification and actualisation of the tourism potential of cultural heritage places. This paper presents a new model that is in the process of development, but which has the potential to assist in planning for sustainable cultural heritage tourism. Future testing of the model is likely to make a significant contribution to the advancement of both disciplines and also should help break down barriers between the two. The model is a matrix into which heritage places can be classified as falling into nine general areas of suitability for tourism in terms of their market appeal and ability to withstand the impacts of visitation likely to be associated with that appeal. Copyright © 2001 John Wiley & Sons, Ltd.
Tourism and economic regeneration: the role of skills development
Authors: Thomas Rhodri , Long Jonathan 
Published: August 2002

AbstractAn increasing number of local economic development agencies in the UK are turning to tourism as a means of urban regeneration and employment creation. Although initiatives vary, there is a nationally inspired emphasis on the development of employee skills as a core element of many regeneration strategies. This paper reports the findings of a qualitative study of the demand for and utilisation of skills by tourism firms in East London, an area that is the recipient of substantial urban aid funding, a proportion of which has an overt focus on skills enhancement designed to develop the tourism sector. It then examines the processes of skills supply within the locality. The paper concludes by identifying the key issues likely to be important if regeneration programmes are to be effective. Copyright
© 2001 John Wiley & Sons, Ltd.
Joint ventures between communities and tourism investors: experience in southern Africa
Authors: Ashley Caroline , Jones Brian 
Published: August 2002

AbstractTourism joint ventures between communities and private investors are an emerging trend in southern Africa. In each country they take different forms. This paper reviews experience in Namibia, within the wider regional context, in order to identify some key principles and challenges. Several lessons can be learnt from the eight Namibian negotiations, and three operating ventures concerning the long process of establishing joint ventures, and about the positive and negative impacts it has for both parties, which cover a range of commercial and livelihood concerns. The analysis suggests several critical factors influence joint‐venture success including: committed individuals, company philosophy, facilitation, time and trust, local institutions, national policy context and tourism market trends. Regional comparison indicates that critical factors need to be present in some, but widely varying, form. Joint ventures should become easier to develop as lessons are shared. Although they will remain a niche market, owing to high transaction costs, further policy and practical support can help develop this promising potential. Copyright © 2001 John Wiley & Sons, Ltd.
A consensus view of the temperature dependence of the gas phase reaction: OH + HBr → H2O + Br
Authors: Jaramillo Veronica I. , Gougeon Samuel , Le Picard Sébastien D. , Canosa André , Smith Mark A. , Rowe Bertrand R. 
Published: August 2002

AbstractThe temperature dependence of the rate coefficient for the reaction, OH + HBr has been reinvestigated at low temperatures (T = 48–224 K) by using uniform supersonic flow reactors with laser induced fluorescence detection. This paper presents two forms of global fits: k(T) = 1.11 × 10−11 (T/298)−0.91 cm3 s−1 and k(T) = 1.06 × 10−11 (T/298)−1.09 $\exp({-10.5 K\over T})$ cm3 s−1, both of which accurately describe the temperature dependence of the rate coefficient for the title reaction within the temperature range 20–350 K. These fits indicate that at temperatures below 200 K, the rate coefficient for this reaction shows inverse temperature dependence, while above 200 K the reaction shows insignificant temperature dependence. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 339–344, 2002
Trans ligand influence in cobalt(III) Schiff base complexes: Electronic and steric effects on the kinetics of hydrolysis
Authors: Amirnasr Mehdi , Vafazadeh Rasoul 
Published: August 2002

AbstractRate constants for the hydrolysis (kh) of six different amines in trans‐[Co((BA)2en)(amine)2]ClO4 complexes (amine = aniline 1a, para‐toluidine 1b, benzylamine 1c (primary amines), pyrrolidine 2a, piperidine 2b, morpholine 2c (secondary amines), and (BA)2en = Bisbenzoylacetoneethylenediiminato) in mixed methanol/water (1:1) solvent have been determined between 30 and 55°C. The hydrolysis product of 2c, trans‐[Co((BA)2en)(morpholine)(H2O)]ClO4, has been separately prepared and characterized by UV–vis and 1H NMR spectroscopy. Depending on the nature of the axial amine ligand the limiting first‐order rate constants for the amine hydrolysis at 40°C range from (3.42 ± 0.10) × 10−5 to (5.32 ± 0.13) × 10−5 s−1. At the first glance, a reasonable trend cannot be established between kh and the basicity or the inductive trans effect of the amine ligands. However, when the complexes are classified into two groups, based on the type of the amine (primary and secondary), the values of kh correlate well with the basicity or inductive effect of the amine in each group. The observed trend in kh values for the complexes with primary amines is 1a (5.32 ± 0.13) × 10−5 s−1 > 1b (3.51 ± 0.14) × 10−5 > 1c (1.72 ± 0.03) × 10−5 (40°C), which is opposite to the amine basicity strength. In the case of the complexes with secondary amines, the observed trend in kh values is in accord with amine basicity (or inductive trans effect), i.e. 2a (5.02 ± 0.22) × 10−5 > 2b (4.18 ± 0.10) × 10−5 > 2c (3.42 ± 0.10) × 10−5 s−1 (40°C). © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 387–393, 2002