bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic control of the tetrapyrrole biosynthetic pathway for porphyrin distribution in the barley mutant albostrians
Authors: Yaronskaya Elena , Ziemann Valeria , Walter Gaby , Averina Natalia , Börner Thomas , Grimm Bernhard 
Published: August 2003

SummaryThe barley line albostrians exhibits a severe block in chloroplast development as a result of a mutationally induced lack of plastid ribosomes. White leaves of this mutant contain undifferentiated plastids, possess only traces of chlorophyll (Chl), and are photosynthetically inactive. Chl deficiency, combined with a continuous heme requirement, should lead to drastic changes in the tetrapyrrole metabolism in white versus green leaves. We analyzed the extent to which the synthesis rate of the pathway and the porphyrin distribution toward the Chl‐ and heme‐synthesizing bifurcation is altered in the white tissue of albostrians. Expression and activity of several distinctively regulated enzymes, such as glutamyl‐tRNAglu reductase, glutamate 1‐semialdehyde aminotransferase, Mg‐ and Fe‐chelatase, and Chl synthetase, were altered in white mutant leaves in comparison to control leaves. A drastic loss in the rate‐limiting formation of 5‐aminolevulinate and in the Mg‐chelatase and Mg‐protoporphyrin IX methyltransferase activity, as well as an increase in Fe‐chelatase activity, accounts for a decrease in the metabolic flux and the re‐direction of metabolites. It is proposed that the tightly balanced control of activities in the pathway functions by different metabolic feedback loops and in response to developmental state and physiological requirements. This data supports the idea that the initial steps of Mg‐porphyrin synthesis contribute to plastid‐derived signaling toward the nucleus. The barley mutant albostrians proved to be a valuable system for studying regulation of tetrapyrrole biosynthesis and their involvement in the bi‐directional communication between plastids and nucleus.
Does benchmarking help?
Authors: Ansell J. , Moles P. , Smart A. 
Published: August 2003

AbstractIn this paper we examine benchmarking as it is used in fund management and especially asset allocation. We explore the concept of benchmarking in fund management, and selection of the appropriate benchmark. Some of the major problems associated with benchmarking are dealt with, including the risks involved and measures taken to deal with the inherent risk, such as risk adjustment. Finally we advocate that trustees need to interact with fund managers more closely if the fund is to develop in the desired direction. This should include an understanding of the organisational aspects of the fund manager's role.
Evaluation of a Novel Medium for Screening Specimens from Hospitalized Patients To Detect Methicillin-Resistant
Staphylococcus aureus
Authors: Blanc D. S. , Wenger A. , Bille J. 
Published: August 2003

ABSTRACT

A novel medium, Oxacillin Resistant Screening Agar (ORSA) medium, was evaluated for the screening of specimens for methicillin-resistant
Staphylococcus aureus
(MRSA) in the hospital setting. Screening swabs (swabs of the nose, throat, perineum, and infected sites) were inoculated onto the new ORSA medium and into an enrichment broth (Muller-Hinton broth supplemented with NaCl and oxacillin). After 24 h of incubation, the enrichment broth was subcultured onto one ORSA plate and one lipovitellin Chapman salt agar plate. The sensitivities for the detection of MRSA were calculated for each medium alone and for the media in combination. A low sensitivity (74%) was obtained when ORSA medium was used alone as a primary culture, whereas the sensitivity was 88% when a single selective enrichment broth was used. Among the 414 blue colonies observed on ORSA plates, only 47% were found to be MRSA, 40% were coagulase-negative staphylococci, 7% were
Enterococcus
species, and 2% were methicillin-sensitive
S. aureus
. The optimal incubation time for the ORSA plates was evaluated. On primary culture, 38% of the blue MRSA colonies were visible only after 48 h of incubation (no blue colonies were not seen after 24 h of incubation), whereas 94% of the colonies were already visible at 24 h when ORSA plates were used for subcultures. In conclusion, the advantage of the novel ORSA medium is the ease of recognition of mannitol-fermenting bacteria, but further identification tests are needed to confirm the identification of
S. aureus
. An enrichment broth is still needed to ensure a good sensitivity for the recovery of MRSA, and an incubation time of 48 h is required for primary culture on ORSA medium.
Penicillin Susceptibility and Epidemiological Typing of Invasive Pneumococcal Isolates in the Republic of Ireland
Authors: Bennett D. , Lennon B. , Humphreys H. , Cafferkey M. 
Published: August 2003

ABSTRACT

A national study was undertaken to investigate the incidence of invasive pneumococcal disease in the Republic of Ireland and to examine the associated isolates. In 1999, 144
S. pneumoniae
isolates, all recovered from cases of invasive disease, were received from 12 microbiology laboratories. The incidence of invasive pneumococcal disease was estimated to be 6.6/100,000 population. All isolates were analyzed for serotype, penicillin susceptibility, chromosomal relatedness (by using pulsed-field gel electrophoresis [PFGE]), and penicillin-binding protein (
pbp
) fingerprinting. Several findings of note were observed regarding the pneumococcal population in Ireland. First, isolates of 25 different serotypes were represented, with serotypes 14, 9V, 8, 5, 4, and 3 being the most common. This finding, together with the
pbp
fingerprinting and PFGE typing results, indicated the clonal spread of strains of these serotypes in Ireland. Second, 27 (18.7%) isolates had reduced susceptibility to penicillin, and 74% of these were serotype 9V. Of these, 80% appeared to belong to the same clone. This could suggest the spread of the international Spanish/French 9V penicillin-resistant clone into Ireland. Third, nine different
pbp
genotypes were identified, four of which were new. Two
pbp
genotypes accounted for the majority of isolates dividing them according to their penicillin susceptibility status but irrespective of serotype and PFGE type. This is strong evidence for the occurrence of horizontal transfer of
pbp
genes between strains, observed with both penicillin-susceptible and penicillin-nonsusceptible isolates. Fourth, there was evidence of serotype transformation since isolates, indistinguishable by
pbp
fingerprinting and PFGE typing, expressed different capsular types.
Genetic and Antigenic Characterization of Rotavirus Serotype G9 Strains Isolated in Australia between 1997 and 2001
Authors: Kirkwood Carl , Bogdanovic-Sakran Nada , Palombo Enzo , Masendycz Paul , Bugg Helen , Barnes Graeme , Bishop Ruth 
Published: August 2003

ABSTRACT
Rotavirus serotype G9 is recognized as the most widespread of the emerging serotypes, emerging since 1996 as a frequent cause of severe acute gastroenteritis in children from many countries covering all continents of the world. This study characterized serotype G9 strains collected in three widely separated Australian centers from 1997 to 2001. All G9 strains possessed the VP4 P[8] and VP6 subgroup II genes. The overall prevalence of the G9 strains increased in Australia, from 0.6% of the strains found in 1997 to 29% of the strains found in 2001. The prevalence of G9 relative to all other serotypes varied from year to year and with geographic location. In Melbourne (representing east coast urban centers), G9 made up 11 to 26% of all of the strains found from 1999 to 2001. In Perth (representing west coast urban centers), G9 made up less than 2% of the strains found in 1997 to 2000 but increased to 18.6% of the strains found in 2001. In Alice Springs (representing widely dispersed settlements in northern arid regions), G9 made up 0 to 5% of the strains found from 1997 to 2000 and was the dominant strain in 2001, making up 68.9% of all of the strains found. Three distinct antigenic groups based on reaction with neutralizing monoclonal antibodies (N-MAbs) were identified, including a dominant group (63%) that cross-reacted with the serotype G4 N-MAb. Phylogenetic analysis of the VP7-encoding gene from Australian strains, compared with a worldwide collection of G9 strains, showed that the Australian G9 strains made up a genetic group distinct from other serotype G9 strains identified in the United States and Africa. Future epidemiological studies of the occurrence of G9 strains should combine reverse transcription-PCR and typing with G1 to G4 and G9 N-MAbs to determine the extent of G9 and G4 cross-reactions among rotavirus strains, in order to assess the need to incorporate G9 strains into new candidate vaccines.
Identification of the Hypervirulent Lineages of
Neisseria meningitidis
, the ST-8 and ST-11 Complexes, by Using Monoclonal Antibodies Specific to
Nme
DI
Authors: Claus Heike , Weinand Hanne , Frosch Matthias , Vogel Ulrich 
Published: August 2003

ABSTRACT

Most cases of serogroup C meningococcal disease are caused by the clonal lineages ST-8 and ST-11. The gene encoding the putative restriction-modification system
Nme
DI is specific to these lineages. We report here a monoclonal antibody directed against the
Nme
DI endonuclease as a tool for their rapid and spe-cific identification.
Genetic Relationship between
Streptococcus pneumoniae
Isolates from Nasopharyngeal and Cerebrospinal Fluid of Two Infants with Pneumococcal Meningitis
Authors: de Andrade Ana Lucia Sampaio Sgambatti , Pimenta Fabiana Cristina , Brandileone Maria Cristina C. , Laval Cristina Aparecida , Guerra Maria Luiza , de Andrade João Guimarães , Di Fabio Jose Luis 
Published: August 2003

ABSTRACT

The molecular epidemiology of
Streptococcus pneumoniae
isolates from carriage and cerebrospinal fluid (CSF) concurrently recovered from the same individual has not yet been reported. By using pulsed-field gel electrophoresis, we demonstrated the genetic linkage among strains from CSF and nasopharynges of two children with pneumococcal meningitis.
Mechanistic limitations in the synthesis of polyesters by lipase‐catalyzed ring‐opening polymerization
Authors: Panova Anna A. , Kaplan David L. 
Published: August 2003

AbstractLipase‐catalyzed polymerization of caprolactone (CL) in toluene with methoxy‐poly(ethylene glycol) (MPEG) and water as initiators was characterized in detail for mechanistic insight. 1H NMR analysis of polycaprolactone chains (PCL), dicaprolactone, degree of esterification of MPEG, and fractions of PCL chains initiated by MPEG and water were used to follow the reactions. The data were analyzed with the kinetic scheme involving formation of the acylenzyme and its consequent reaction with MPEG, water, or PCL to yield the MPEG‐ or water‐initiated PCL chains, or increase in PCL length. A limit for MPEG initiator esterification in lipase‐catalyzed CL polymerization was observed and was explained by preferential reaction of PCL propagation over MPEG esterification at long reaction times and low MPEG concentrations. Slower monomer conversion in concentrated monomer solutions was explained by decreased partitioning of PCL between the solvent and the enzyme. This effect resulted in inhibition of the lipase by the reaction product, PCL chains, and/or insufficient diffusion of monomer to the enzyme active site. High monomer/initiators ratio in these solutions did not yield longer polymer chains due to decreased monomer conversion and the corresponding decrease in product yields; lower yields were also observed for chain initiation by MPEG and water. A shift in the reaction rate‐limiting step from formation of acylenzyme in dilute CL solutions to its deacylation in concentrated CL solutions yielded higher PCL polydispersity due to increased initiation by water. Enhanced intramolecular cyclization was also observed. Endgroup composition of PCL chains was influenced by the concentration of monomer, ratio of initiators (MPEG and water), and reaction time, yielding PCL chains initiated exclusively by MPEG at “infinite reaction times.” © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84: 103–113, 2003.
Experimental study of water fluxes in a residential area: 2. Road infiltration, runoff and evaporation
Authors: Ragab R. , Rosier P. , Dixon A. , Bromley J. , Cooper J. D. 
Published: August 2003

AbstractLack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water‐table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October–March) and summer (April–September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21–24% of annual rainfall, with more evaporation taking place during summer than winter. Copyright © 2003 John Wiley & Sons, Ltd.
Testing in‐class variability of groundwater systems: local upland systems
Authors: Petheram Cuan , Dawes Warrick , Walker Glen , Grayson Rodger B. 
Published: August 2003

AbstractThe objective of this paper is to assess the extent that information can be transferred between hydrogeologically similar catchments, by investigating in detail one set of similar catchments. In particular, five examples of a class of deeply weathered, fractured rock aquifers were used as the basis for this assessment. This catchment type was chosen because of its prominence in salinized regions in southeastern Australia. The catchments chosen encompass a wide variety of scales, gradients, and climatic zones. The five catchments were modelled using FLOWTUBE. Catchment parameter values, catchment response to incremental reductions in recharge and the similarity of the catchments were compared. The results suggest that there is a considerable range in parameter values, but that this is smaller than the range for all aquifer types. However, given the sensitivity of the models to transmissivity and specific yield, the range of values was too high to allow the transfer of ‘averaged’ values to other hydrogeologically similar catchments with confidence. Evaluation of a dimensionless similarity parameter G for each of the five catchments indicates that the parameters of transmissivity, specific yield, length and head may be interrelated. The implications of this are: (1) that the range in catchment responses might not be as great as suggested by standard sensitivity studies; (2) surrogate parameters may exist, which would enable aquifer parameters to be transferred to other hydrogeologically similar catchments with greater confidence. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of 2‐aryl‐1,3,4‐oxadiazoles by 15N and 13C NMR spectroscopy
Authors: Nowak‐Wydra Barbara , Gierczyk Błażej , Schroeder Grzegorz 
Published: August 2003

Abstract15N NMR chemical shifts of 2‐aryl‐1,3,4‐oxadiazoles were assigned on the basis of the 1H–15N HMBC experiment. Chemical shifts of the nitrogen and carbon atoms in the oxadiazole ring correlate with the Hammett σ‐constants of substituents in the aryl ring (r2 ≥ 0.966 for N atoms). 15N NMR data are a suitable and sensitive means for characterizing long‐range electronic substituent effects. Additionally, 13C NMR data for these compounds are presented. Copyright © 2003 John Wiley & Sons, Ltd.
Longitudinal evaluation of bronchopulmonary disease in children with cystic fibrosis
Authors: Farrell Philip M. , Li Zhanhai , Kosorok Michael R. , Laxova Anita , Green Christopher G. , Collins Jannette , Lai Hui‐Chuan , Makholm Linda M , Rock Michael J. , Splaingard Mark L. 
Published: August 2003

AbstractChildren with cystic fibrosis (CF) develop bronchopulmonary disease at variable ages. Determining the epidemiology of chronic lung disease and quantifying its severity, however, have been difficult in infants and young children. As part of the Wisconsin CF Neonatal Screening Project, we were presented with an ideal opportunity to assess longitudinally the evolution of symptoms, signs, and quantitative measures of CF respiratory disease. After newborn screening test results led to early recognition, 64 patients diagnosed at a median age of 6.71 weeks were enrolled and studied systematically at a median age of 11.3 years to obtain clinical information, chest radiographs, and pulmonary function tests. Our observations revealed that a frequent cough by history is evident by 10.5 months of age in half the patients. Quantitative chest radiology (CXR scoring) demonstrated that potentially irreversible abnormalities are present in half the children by 2 years. The severity of Wisconsin and Brasfield CXR scores increased in association with respiratory infections. Longitudinal progression of Wisconsin CXR scores was related to age (P < 0.001), pancreatic insufficiency (P = 0.005), and respiratory secretion cultures positive forStaphylococus aureas(P = 0.039). In contrast, serial spirometry showed limited sensitivity, as did lung volume determinations; neither was satisfactory as repeated measures with acceptable quality control until after 7 years of age. Time to event analyses revealed that half the patients had % predicted FEF25–75and FEV1/FVC values greater than 80% until 10.7 and 9.9 years, respectively. We conclude that of the methods evaluated, quantitative chest radiology is currently the best procedure for frequent assessment of bronchopulmonary disease in CF, and that radiographic progression is evident in approximately 85% of patients by 5 years of age. Our results also suggest that bronchiectasis and other radiographic evidence of chronic infection are apparent prior to airways obstruction in young CF patients. Pediatr Pulmonol. 2003; 36:230–240. © 2003 Wiley‐Liss, Inc.
Spatial profiling of protein hydrophobicity: Native vs. Decoy structures
Authors: Zhou Ruhong , Silverman B. David , Royyuru Ajay K. , Athma Prasanna 
Published: August 2003

AbstractA recent study of 30 soluble globular protein structures revealed a quasi‐invariant called the hydrophobic ratio. This invariant, which is the ratio of the distance at which the second order hydrophobic moment vanished to the distance at which the zero order moment vanished, was found to be 0.75 ± 0.05 for 30 protein structures. This report first describes the results of the hydrophobic profiling of 5,387 non‐redundant globular protein domains of the Protein Data Bank, which yields a hydrophobic ratio of 0.71 ± 0.08. Then, a new hydrophobic score is defined based on the hydrophobic profiling to discriminate native‐like proteins from decoy structures. This is tested on three widely used decoy sets, namely the Holm and Sander decoys, Park and Levitt decoys, and Baker decoys. Since the hydrophobic moment profiling characterizes a global feature and requires reasonably good statistics, this imposes a constraint upon the size of the protein structures in order to yield relatively smooth moment profiles. We show that even subject to the limitations of protein size (both Park & Levitt and Baker sets are small protein decoys), the hydrophobic moment profiling and hydrophobic score can provide useful information that should be complementary to the information provided by force field calculations. Proteins 2003;52:561–572. © 2003 Wiley‐Liss, Inc.
The effects of scheduling flexibility on the performance of a flexible manufacturing system
Authors: Chan F T S 
Published: August 2003

In today's industries, flexible manufacturing systems (FMSs) play an important role in manufacture. An FMS is a modern technology that helps to improve the factories by improving their response time, lowering their unit costs and producing better quality goods. It is designed to combine the efficiency of mass-production of mid-volume and mid-variety products. In this paper, the performance of an FMS is evaluated in terms of makespan, average flow time, average delay time at local buffers and average machine utilization, observing the effects of different scheduling flexibilities, which include dispatching and routeing flexibilities. The three routeing policies considered in this paper are ‘no alternative routeings’, ‘alternative routeings dynamic’ and ‘alternative routeings planned’. The above routeing policies are combined with seven dispatching rules and are studied in different production volumes which vary from 50 to 500 parts. In addition, the impact of both infinite and finite local buffer capacities is analysed. Since an FMS usually deals with a variety of products, the effects of changing the part mix ratio are also discussed. Finally, the study of machine failure is also covered in this research.
Silencing of retroviral vector transduced LacZ reporter gene by frameshift mutation
Authors: Valkova Christina , Georgiev Oleg , Karagyozov Luchezar , Milchev Georgi 
Published: August 2003

AbstractMoloney murine leukemia virus‐based vector expressing Escherichia coli β‐galactosidase (lacZ) as reporter gene and the transposon Tn5 neomycin resistance (neo) gene was transduced at low‐multiplicity of infections into NIH 3T3 cells. Geneticin (G418)‐resistant cells were recloned and cell lines containing β‐galactosidase positive or β‐galactosidase negative cells were obtained. Both positive and negative cell lines contained a single proviral copy at distinct integration sites. RNA complementary to lacZ was detected in β‐galactosidase positive as well as in one of three investigated β‐galactosidase negative cell lines. DNA sequence analysis of proviral LacZ gene in β‐galactosidase negative cell line C6 showed a single nucleotide insertion at position 1567 resulting in reading frame shift and translational stop codon at position 1629. This mutation explains the enzyme inactivation. The absence of β‐galactosidase after retroviral transduction of LacZ reproter gene may be a consequence of definite mutation but not a consequence of ineffective transduction or transcriptional inactivation of transgene. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 84:1–6, 2003.