bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling the water balance of a free‐draining lysimeter using the downward approach
Authors: Struthers Iain , Hinz Christoph , Sivapalan Murugesu , Deutschmann G. , Beese F. , Meissner R. 
Published: August 2003

AbstractA 2600 m3 free‐draining lysimeter constructed in a Pinus sylvestris plantation forest in Colbitz, Germany, has been monitored daily since 1974, with the intent of improving the understanding the effect of afforestation upon groundwater recharge (drainage). The objective of this research was to employ a downward approach in the development of a conceptual water balance model applicable to the site. Observed annual and inter‐annual trends were successfully replicated by a simple capacitance model using a simplified representation of vegetation growth. An important limitation of the capacitance approach in simulating the timing of drainage at sub‐annual time scales was identified, which could not be overcome by adding complexity to the model basis. Given the a priori use of capacitance approaches for simulating drainage in many hydrological models, the findings of this study suggest that (a) these approaches are sufficient where the prediction of annual and inter‐annual drainage behaviour is the primary objective, and that (b) an alternative basis accounting for the time delay between precipitation inputs and drainage generation is required for modelling if the prediction of drainage at sub‐annual time scales is a priority. Copyright © 2003 John Wiley & Sons, Ltd.
Complete 1H and 13C NMR assignment for aryl diisoprenes
Authors: Zambrano Jorge L. , Rosales Viale 
Published: August 2003

AbstractThe characterization of four aryl diisoprenes was carried out by 1D‐ and 2D‐NMR methods, which permitted the assignment of the signals of all protons and all carbon atoms. Copyright © 2003 John Wiley & Sons, Ltd.
1H and 13C NMR spectral assignments of some natural abietane diterpenoids
Authors: Rodríguez Benjamín 
Published: August 2003

AbstractAn NMR study of 11 naturally occurring abietane diterpenoids is described. In addition to one‐dimensional NMR methods, including DPFGSE 1D‐NOE spectra, two‐dimensional shift‐correlated experiments [1H,1H COSY, 1H,13C‐gHSQC 1J(C,H) and 1H,13C‐gHMBC nJ(C,H) (n = 2 and 3)] were used for the complete and unambiguous 1H and 13C chemical shift assignments of these substances. Copyright © 2003 John Wiley & Sons, Ltd.
Dynamic 15N NMR studies of iron phosphine complexes containing coordinated dinitrogen
Authors: Field Leslie D. , Hazari Nilay , Li Hsiu Lin , Luck Ian J. 
Published: August 2003

AbstractThe 15N‐labelled iron dinitrogen complexes trans‐[FeH(N2)(PP)2]+[BPh4]− (PP = dppe, depe, dmpe) and cis‐[FeH(N2)(PP3)]+[BPh4]− were prepared in situ by exchange of unlabelled coordinated dinitrogen with 15N2. 15N NMR chemical shifts and coupling constants are reported. The 15N spectra exhibit separate signals for the metal‐bound and terminal nitrogen atoms of the coordinated N2. The 15N resonances display 15N, 15N coupling as well as 31P, 15N coupling and long‐range 15N, 1H coupling when there is a metal‐bound hydrido ligand. Exchange between free and coordinated dinitrogen was monitored by magnetization transfer between 15N‐labelled sites using an inversion–transfer–recovery experiment. Exchange between the metal‐bound and terminal nitrogen atoms of coordinated N2 was also monitored by magnetization transfer and this could proceed by N2 dissociation or by an intramolecular process. Copyright © 2003 John Wiley & Sons, Ltd.
Correlation between standing height, sitting height, and arm span as an index of pulmonary function in 6–10‐year‐old children
Authors: Torres Lídia A.G.M.M. , Martinez Francisco E. , Manço José C. 
Published: August 2003

AbstractThe present study evaluates the relationships of pulmonary volumes and flows and the anthropometric variables of standing height, sitting height, and arm span in 100 6–10‐year‐old children. To be included in the study, all children were required to be healthy and above the 3rd percentile of the curve of Tanner et al. (Arch Dis Child 1966;41:454–471; Arch Dis Child 1966;41:613–635) for height and weight. Standing height, sitting height, and arm span were measured according to standard protocol. The pulmonary function measurements were: tidal volume, minute respiratory volume, respiratory rate, expiratory reserve volume, inspiratory capacity, vital capacity, residual volume (RV), functional residual capacity, total lung capacity (TLC), forced vital capacity (FVC), forced expiratory volume in 1 sec of FVC (FEV1), forced expiratory flow measured between 25–75% of FVC, and FEV1/FVC and RV/TLC ratios. Simple linear regression best expressed the correlation between pulmonary function and the anthropometric variables. Significant correlations between anthropometric and pulmonary function measurements were observed, with FVC and FEV1 showing the highest and RV the lowest r2 values. There was a significant positive correlation between standing height and arm span according to linear regression and Bland‐Altman comparison (Bland and Altman, Lancet 1968;8:307–310). Our results suggest that when an accurate determination of standing height cannot be obtained, arm span could be used interchangeably, using the same regression equation. However, for patients with limb deformities, regression equations of pulmonary function measurements in relation to sitting height may be a better choice for estimating pulmonary function. Pediatr Pulmonol. 2003; 36:202–208. © 2003 Wiley‐Liss, Inc.
Migration to a western country increases asthma symptoms but not eosinophilic airway inflammation
Authors: Gibson Peter G. , Henry Richard L. , Shah Smita , Powell Heather , Wang He 
Published: August 2003

AbstractThe prevalence of asthma symptoms varies markedly throughout the world. However, the asthma mechanisms involved are not defined. Studying the effects of migration can help identify the reasons for this geographic variation. The aims of this study were to examine the prevalence of asthma symptoms, airway hyperresponsiveness (AHR), and induced sputum eosinophils in adolescents who migrate to Australia. The study was conducted in Sydney, Australia, where adolescent students completed a video symptom questionnaire, hypertonic saline challenge, sputum induction, and allergy skin testing. The 211 students had widely different cultural backgrounds, including Asian, South Pacific, Middle Eastern, European, and African countries. Among adolescents who were migrants to Australia, the prevalence of asthma symptoms was higher than that reported using a similar methodology in their country of origin. Asthma symptom prevalence was related to residence time in Australia. The prevalence of wheeze was 17.2% in recent arrivals, 20.5% in adolescents living in Australia for >2 years, and 36.3% in those living all their lifetime in Australia (P = 0.013). For every year of residence in Australia, there was an 11% increase in prevalence of current wheeze (odds ratio, 1.11;P = 0.02). This effect was not related to atopy, AHR, or eosinophilic airway inflammation. Sputum neutrophils were elevated in recent arrivals. In conclusion, adolescents who migrate to Australia report increased asthma symptoms, compared to their country of origin, and asthma symptoms are further increased for every additional year of residence in Australia. The development of wheeze after migration to Australia was independent of eosinophilic inflammation and consistent with noneosinophilic asthma mechanisms. Pediatr Pulmonol. 2003; 36:209–215. © 2003 Wiley‐Liss, Inc.
Changes in lung volume and work of breathing: A comparison of two variable‐flow nasal continuous positive airway pressure devices in very low birth weight infants
Authors: Courtney Sherry E. , Aghai Zubair H. , Saslow Judy G. , Pyon Kee H. , Habib Robert H. 
Published: August 2003

AbstractVariable flow nasal continuous positive airway pressure (VF‐NCPAP) recruits lung volume more effectively and reduces work of breathing (WOB) compared to constant‐flow NCPAP (CF‐NCPAP) in very low birth weight (VLBW) infants. Because different VF‐NCPAP devices have somewhat different flow patterns, whether different VF‐NCPAP devices function similarly is unknown. We compared two VF‐NCPAP devices: the Infant Flow™ (EME, Ltd.) and the Arabella® (Hamilton Medical) to assess whether lung volume recruitment and WOB were similar in VLBW infants requiring NCPAP. Eighteen infants <1,500 g were studied on both NCPAP devices applied in random order. All infants required NCPAP for mild respiratory distress. Calibrated DC‐coupled respiratory inductance plethysmography (RIP) was used to assess lung volume changes. NCPAP was first increased to 8 cmH2O to allow comparable recruitment in all infants, and then was slowly decreased to 6, 4, and 0 cmH2O, with data collection at each level. Mean birth weight (±SD) was 1,107 ± 218 g, gestational age was 27.9 ± 2.0 weeks, weight at study was 1,092 ± 222 g, and age at study was 4.6 ± 4.3 days. There were no differences in lung volume recruitment overall or at any NCPAP level (P = 0.943). No differences were found in either inspiratory WOB (P = 0.468) or in resistive WOB (P = 0.610) between devices. Compliance, tidal volume, respiratory rate, and minute ventilation were also similar. Despite differences in flow characteristics between the two VF‐NCPAP devices we studied, lung volume recruitment and WOB were similar. Pediatr Pulmonol. 2003; 36:248–252. © 2003 Wiley‐Liss, Inc.
How well can we predict native contacts in proteins based on decoy structures and their energies?
Authors: Zhu Jiang , Zhu Qianqian , Shi Yunyu , Liu Haiyan 
Published: August 2003

AbstractOne strategy for ab initio protein structure prediction is to generate a large number of possible structures (decoys) and select the most fitting ones based on a scoring or free energy function. The conformational space of a protein is huge, and chances are rare that any heuristically generated structure will directly fall in the neighborhood of the native structure. It is desirable that, instead of being thrown away, the unfitting decoy structures can provide insights into native structures so prediction can be made progressively. First, we demonstrate that a recently parameterized physics‐based effective free energy function based on the GROMOS96 force field and a generalized Born/surface area solvent model is, as several other physics‐based and knowledge‐based models, capable of distinguishing native structures from decoy structures for a number of widely used decoy databases. Second, we observe a substantial increase in correlations of the effective free energies with the degree of similarity between the decoys and the native structure, if the similarity is measured by the content of native inter‐residue contacts in a decoy structure rather than its root‐mean‐square deviation from the native structure. Finally, we investigate the possibility of predicting native contacts based on the frequency of occurrence of contacts in decoy structures. For most proteins contained in the decoy databases, a meaningful amount of native contacts can be predicted based on plain frequencies of occurrence at a relatively high level of accuracy. Relative to using plain frequencies, overwhelming improvements in sensitivity of the predictions are observed for the 4_state_reduced decoy sets by applying energy‐dependent weighting of decoy structures in determining the frequency. There, approximately 80% native contacts can be predicted at an accuracy of approximately 80% using energy‐weighted frequencies. The sensitivity of the plain frequency approach is much lower (20% to 40%). Such improvements are, however, not observed for the other decoy databases. The rationalization and implications of the results are discussed. Proteins 2003;52:598–608. © 2003 Wiley‐Liss, Inc.
Structure, evolution, and inhibitor interaction of S‐adenosyl‐L‐homocysteine hydrolase from Plasmodium falciparum
Authors: Bujnicki Janusz M. , Prigge Sean T. , Caridha Diana , Chiang Peter K. 
Published: August 2003

AbstractS‐adenosylhomocysteine hydrolase (SAHH) is a key regulator of S‐adenosylmethionine–dependent methylation reactions and an interesting pharmacologic target. We cloned the SAHH gene from Plasmodium falciparum (PfSAHH), with an amino acid sequence agreeing with that of the PlasmoDB genomic database. Even though the expressed recombinant enzyme, PfSAHH, could use 3‐deaza‐adenosine (DZA) as an alternative substrate in contrast to the human SAHH, it has a unique inability to substitute 3‐deaza‐(±)aristeromycin (DZAri) for adenosine. Among the analogs of DZA, including neplanocin A, DZAri was the most potent inhibitor of the PfSAHH enzyme activity, with a Ki of about 150 nM, whether Ado or DZA was used as a substrate. When the same DZA analogs were tested for their antimalarial activity, they also inhibited the in vitro growth of P. falciparum parasites potently. Homology‐modeling analysis revealed that a single substitution (Thr60‐Cys59) between the human and malarial PfSAHH, in an otherwise similar SAH‐binding pocket, might account for the differential interactions with the nucleoside analogs. This subtle difference in the active site may be exploited in the development of novel drugs that selectively inhibit PfSAHH. We performed a comprehensive phylogenetic analysis of the SAHH superfamily and inferred that SAHH evolved in the common ancestor of Archaea and Eukaryota, and was subsequently horizontally transferred to Bacteria. Additionally, an analysis of the unusual and uncharacterized AHCYL1 family of the SAHH paralogs extant only in animals reveals striking divergence of its SAH‐binding pocket and the loss of key conserved residues, thus suggesting an evolution of novel function(s). Proteins 2003;52:624–632. © 2003 Wiley‐Liss, Inc.
The Arabidopsis MEI1 gene encodes a protein with five BRCT domains that is involved in meiosis‐specific DNA repair events independent of SPO11‐induced DSBs
Authors: Mathilde Grelon , Ghislaine Gendrot , Daniel Vezon , Georges Pelletier 
Published: August 2003

Summary Arabidopsis thaliana MEI1 was first described as a gene involved in male meiosis, encoding a short protein showing homology with a human acrosin–trypsin inhibitor. We have isolated a new allele of mei1, and shown that in both mutants male and female meiosis are affected. In both reproductive pathways, meiosis proceeds while chromosomes become fragmented, resulting in aberrant meiotic products and in a strongly reduced fertility. We have shown that the gene mutated in mei1 mutants actually encodes a protein of 972 amino acids that contains five BRCA1 C‐terminus (BRCT) domains and is similar to proteins involved in the response to DNA damage and replication blocks in eukaryotes. During meiosis, recombination is initiated by the formation of DNA double strand breaks (DSBs) induced by the protein SPO11. We analysed meiotic chromosome behaviour of the mei1 mutant in a spo11 mutant background and proved that the meiotic fragmentation observed in mei1 mutants was not the consequence of defects in the repair of meiotic DSBs induced by SPO11. We also analysed the effect of mei1 on the mitotic cell cycle but could not detect any sensitivity of mei1 seedlings to DNA‐damaging agents like γ‐rays or UV. Therefore, MEI1 is a BRCT‐domain‐containing protein that could be specific to the meiotic cell cycle and that plays a crucial role in some DNA repair events independent of SPO11 DSB recombination repair.
Why green fluorescent fusion proteins have not been observed in the vacuoles of higher plants
Authors: Tamura Kentaro , Shimada Tomoo , Ono Eiichiro , Tanaka Yoshikazu , Nagatani Akira , Higashi Sho‐ich , Watanabe Masakatsu , Nishimura Mikio , Hara‐Nishimura Ikuko 
Published: August 2003

SummaryGreen fluorescent protein (GFP) makes it possible for organelles and protein transport pathways to be visualized in living cells. However, GFP fluorescence has not yet been observed in the vacuoles of any organs of higher plants. We found that the fluorescence of a vacuole‐targeted GFP was stably observed in the vacuoles of transgenic Arabidopsis plants under dark conditions, and that the fluorescence rapidly disappeared under light conditions. The vacuolar GFP was rapidly degraded within 1 h in the light, especially blue light. An inhibitor of vacuolar type H+‐ATPase, concanamycin A, and an inhibitor of papain‐type cysteine proteinase, E‐64d, abolished both the light‐dependent disappearance of GFP fluorescence and GFP degradation in the vacuoles. An in vitro assay showed that bacterially expressed GFP was degraded by extracts of Arabidopsis cultured‐cell protoplasts at an acidic pH in the light. These results suggest that blue light induced a conformational change in GFP, and the resulting GFP in the vacuole was easily degraded by vacuolar papain‐type cysteine proteinase(s) under the acidic pH. The light‐dependent degradation accounts for the failure to observe GFP fluorescence in the vacuoles of plant organs. Our results show that stable GFP‐fluoresced vacuoles are achieved by transferring the plants from the light into the dark before inspection with a fluorescent microscope. This might eliminate a large hurdle in studies of the vacuolar‐targeting machinery and the organ‐ and stage‐specific differentiation of endomembrane systems in plants.
ILR2, a novel gene regulating IAA conjugate sensitivity and metal transport in Arabidopsis thaliana
Authors: Magidin Mónica , Pittman Jon K. , Hirschi Kendal D. , Bartel Bonnie 
Published: August 2003

SummaryPlants can regulate levels of the auxin indole‐3‐acetic acid (IAA) by conjugation to amino acids or sugars, and subsequent hydrolysis of these conjugates to release active IAA. These less active auxin conjugates constitute the majority of IAA in plants. We isolated the Arabidopsis ilr2‐1 mutant as a recessive IAA‐leucine resistant mutant that retains wild‐type sensitivity to free IAA. ilr2‐1 is also defective in lateral root formation and primary root elongation. In addition, ilr2‐1 is resistant to manganese‐ and cobalt‐mediated inhibition of root elongation, and microsomal preparations from the ilr2‐1 mutant exhibit enhanced ATP‐dependent manganese transport. We used a map‐based positional approach to clone the ILR2 gene, which encodes a novel protein with no predicted membrane‐spanning domains that is polymorphic among Arabidopsis accessions. Our results demonstrate that ILR2 modulates a metal transporter, providing a novel link between auxin conjugate metabolism and metal homeostasis.
Control of pollen tube growth: role of ion gradients and fluxes
Authors: Holdaway‐Clarke Terena L. , Hepler Peter K. 
Published: August 2003

SummaryPollen tube growth attracts our attention as a model system for studying cell elongation in plants. The process is fast, it is confined to the tip of the tube, and it is crucial for sexual reproduction in plants. In the enclosed review we focus on the control of pollen tube growth, giving special attention to the role of ions, especially calcium and protons. During the last decade technical advances have made it possible to detect localized intracellular gradients, and extracellular fluxes of calcium and protons in the apical domain. Other ions, notably potassium and chloride, are also receiving attention. An important development has been the realization that pollen tube growth oscillates in rate; in addition, the ion gradients and fluxes oscillate in magnitude. Although all the ionic oscillations show the same period as that of the growth rate, with the exception of extracellular chloride efflux, they are not in phase with growth. Considerable effort is devoted to the elucidation of these different phase relationships, with the view that a hierarchical order may provide clues about those events that are primary vs. secondary in growth control. Attention is also given to the targets for the ions, for example, the secretory system, the cytoskeleton, the cell wall, in an attempt to provide a global understanding of pollen tube growth.ContentsSummary539I.Introduction540II.Ion gradients and flux patterns541III.Oscillations544IV.The need for a Ca2+store547V.Intracellular targets for Ion activity549VI.Extracellular targets for ions: the cell wall552VII.Ions in navigation554VIII.Role of ions in self‐incompatibility555IX.The plasma membrane; site of global coordination and control556X.A model for pollen tube growth557IX.Conclusions558Acknowledgements559References559
Comparison of Molecular Tests for Detection and Quantification of Cell-Associated Cytomegalovirus DNA
Authors: Caliendo Angela M. , Yen-Lieberman Belinda , Baptista Jovana , Andersen Janet , Crumpacker Clyde , Schuurman Rob , Spector Stephen A. , Bremer James , Lurain Nell S. 
Published: August 2003

ABSTRACT

A cell-based standard was developed to compare the COBAS Amplicor CMV Monitor test, the Hybrid Capture System CMV DNA test, and the NucliSens CMV test. The standard was prepared by infecting human foreskin fibroblasts (HFFs) with cytomegalovirus (CMV) strain AD169 at low multiplicity of infection (0.03) and harvesting the cells at 6 h postinfection. Buffy coat cells were added to produce concentrations of from 0 to 10
5
HFFs per 10
6
total cells. Five laboratories performed the Amplicor PCR test and two laboratories performed the NucliSens and Hybrid Capture tests. The Amplicor PCR test was 1.5 to 2.0 log
10
more sensitive than the Hybrid Capture test. The specificities of the Amplicor PCR and Hybrid Capture tests were 100 and 93.8%, respectively. The linear range of the Amplicor PCR and Hybrid Capture tests were 2 to 4.48 log
10
and 3.48 to at least 5.0 log
10
CMV target cells, respectively. The standard deviations of the Amplicor PCR and Hybrid Capture tests varied throughout their linear range, and for both tests the variability was greater for lower concentrations of input CMV DNA. These data allow the direct comparison of viral load values between the Amplicor and Hybrid Capture tests. The analytical sensitivity of the NucliSens test could not be determined by using the 6-h standard, because the low multiplicity of infection and short culture time did not allow for adequate transcription of pp67 late mRNA measured in the test. Extending the incubation time of the standard to 24 h increased the analytical sensitivity of the NucliSens test to 3.0 log
10
target cells.
Evidence for Genetic Linkage between the Gene Segments Encoding NSP4 and VP6 Proteins in Common and Reassortant Human Rotavirus Strains
Authors: Iturriza-Gòmara Miren , Anderton Emma , Kang Gagandeep , Gallimore Chris , Phillips Wendy , Desselberger Ulrich , Gray Jim 
Published: August 2003

ABSTRACTNSP4-encoding genes of 78 human rotavirus strains of common or reassortant genotypes were characterized by reverse transcription-PCR followed by sequencing and phylogenetic analysis. It was found that all the human strains characterized clustered into only two of the five known NSP4 genotypes. Linkage between NSP4 genotypes and VP6 subgroups was 100%, NSP4 genotype A being linked to VP6 of subgroup I (SGI) and NSP4 of genotype B being linked to VP6 of SGII. The diversity among the NSP4- and VP6-encoding genes was significantly less than that among the VP7 and VP4 genes in cocirculating human rotavirus strains. Whereas G and P types appear to be shared among different animal species and humans, the NSP4- and VP6-encoding genes appear to segregate according to their host of origin, suggesting that these two proteins may be host restriction determinants. The NSP4-VP6 association may be structurally determined during rotavirus replication (morphogenesis).