bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two simple wind speed models for practical application under stable conditions
Authors: Cvitan Lidija , S̆inik Nadez̆da , Klaić Zvjezdana Bencetić 
Published: December 2002

AbstractThis paper deals with the utility of Monin‐Obukhov similarity theory for wind speed simulation in stable conditions over flat terrain in northern Croatia. Wind speed profiles observed through a 150‐m deep layer are compared with those obtained from two simple wind speed models. For this purpose, the similarity functions for two stable classes based on Monin‐Obukhov theory are locally determined. They are tested in wind speed simulations using a model based on the Monin‐Obukhov theory (MO) and a model which combines the surface‐layer model of Monin‐Obukhov theory and the Ekman‐Taylor type model (MOE). Under less stable conditions the combined model (MOE) produces better skill, whereas the model based on the Monin‐Obukhov theory (MO) performed better under more stable conditions. Copyright © 2002 Royal Meteorological Society.
A study of the theory and operation of a resonance fluorescence water vapour sensor for upper tropospheric humidity measurements
Authors: Keramitsoglou I , Harries J E , Colling D J , Barker R A , Foot J S 
Published: December 2002

AbstractIn‐situ methods for measuring upper tropospheric humidity are important for two reasons: (i) they can be used as accurate spot measurements with which to calibrate more extensive data from satellites and other sensors; (ii) they can provide high accuracy measurements from aircraft or balloon with which individual processes of transport, phase change or chemistry can be studied.In either case the accuracy of the in‐situ measurement is of paramount importance. This study compares the performance and accuracy of a resonance fluorescence type of sensor (the Fluorescence Water Vapour Sensor) with a standard frost‐point hygrometer.An intercomparison of these two hygrometers has confirmed a long‐standing difference between these two types of sensors (the FWVS overestimates the water vapour volume mixing ratio by 10–20%, depending on pressure). Testing the FWVS experimentally in the laboratory, along with a modelling study of the sensor has revealed that a significant source of error is due to contamination of the FWVS source emission, and the subsequent underestimation of the oxygen absorption cross‐section. Copyright © 2002 Royal Meteorological Society.
On the relationship between Clayton's skill score and expected value for forecasts of binary events
Authors: Wandishin Matthew S. , Brooks Harold E. 
Published: December 2002

AbstractFollowing upon previous efforts to associate standard measures of forecast skill to relative economic value, the connection is established between the Clayton skill score and the range of users who realise positive value from the forecasts. It is also shown that, whereas the maximum relative value that can be obtained from a set of forecasts is based on the probabilities conditioned on the observations, the range of users for whom the forecasts provide positive relative value is based on the probabilities conditioned on the forecasts. Copyright © 2002 Royal Meteorological Society.
Electronic Structures of the Filled Tetrahedral Semiconductor
LiMgN with a Zincblende-Type Structure
Authors: Li Hui-Ping  , Hou Zhu-Feng  , Huang Mei-Chun  , Zhu Zi-Zhong  
Published: December 2002

An ab initio method with mixed-basis norm-conserving non-local
pseudo-potentials has been employed to investigate the electronic
structures of LiMgN. The band structure, electronic density of states
and charge density contour plot of LiMgN are also presented. By the
calculation, we have found that LiMgN with a zincblende-type structure
was an indirect gap semiconductor, and the value of indirect
(Γ-X) energy band gap under the local density approximation was
2.97 eV. In addition, the strong covalent character for Li-N and Mg-N
has also been found in LiMgN.
Specific interactions and phase behavior of poly(2‐vinylpridine)/bisphenol blends
Authors: Li Xue‐Dong , Goh S. H. , Zheng J. W. 
Published: December 2002

AbstractHydrogen‐bonding interaction and miscibility between poly(2‐vinylpyrdine) (P2VPy) and five bisphenols are studied by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and wide angle X‐ray diffraction (WAXD). It is found that the miscibility behavior strongly depends on the flexibility of the bisphenol molecules. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1137–1143, 2003
Optimization of a feed medium for fed‐batch culture of insect cells using a genetic algorithm
Authors: Marteijn R. C. L. , Jurrius O. , Dhont J. , de Gooijer C. D. , Tramper J. , Martens D. E. 
Published: December 2002

AbstractInsect cells have been cultured for over 30 years, but their application is still hampered by low cell densities in batch fermentations and expensive culture media. With respect to the culture method, the fed‐batch culture mode is often found to give the best yields. However, optimization of the feed composition is usually a laborious task. In this report, the successful use of genetic algorithms (GAs) to optimize the growth of insect cells is described. A feed was developed from 11 different medium components, each used at a wide range of concentrations. The feed was optimized within four sets of 20 experiments. The optimized feed was tested in bioreactors and the addition scheme was further improved. The viable‐cell density of HzAm1 (Helicoverpa zea) insect cells improved 550% to 19.5 × 106 cells/mL compared to a control fermentation in an optimized commercial medium. No accumulation of waste products was found, and none of the amino acids was depleted. Glucose was depleted, which suggests that even further improvement is possible. We show that GAs are a successful method to optimize a complex fermentation in a relatively short time frame and without the need of detailed information concerning the cellular physiology or metabolism. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 269–278, 2003.
Bcl‐xL expression interferes with the effects of L‐glutamine supplementation on hybridoma cultures
Authors: Charbonneau Joel R. , Furtak Teresa , Lefebvre Jennie , Gauthier Eric R. 
Published: December 2002

AbstractWhile feeding protocols and ectopic expression of anti‐apoptotic genes have been used to improve the viability of hybridoma cell lines, the effect of the expression levels of survival genes on the behavior of hybridomas following nutrient supplementation is unknown. In this study, we compared the behavior of the Sp2/0‐Ag14 hybridoma (Bcl‐xLlow) and the P3x63‐Ag8.653 myeloma (Bcl‐xLhigh) following culture supplementation with the amino acid L‐glutamine (L‐Gln). Our data revealed that L‐Gln addition substantially increased Sp2/0‐Ag14 cell viability and total cell density, concomitant with a decrease in the rate of cell death. This effect was not seen when other amino acids or D‐glucose (D‐Glc) replaced L‐Gln. The improvement in the culture behavior of Sp2/0‐Ag14 cells was attributed to a reduction in the rate of accumulation of apoptotic cells. On the other hand, L‐Gln supplementation had only a limited effect on the growth of the P3x63‐Ag8.653 cells. Interestingly, Sp2/0‐Ag14 cells over‐expressing Bcl‐xL showed a culture behavior upon L‐Gln complementation that was similar to the P3x63‐Ag8.653 myeloma. These results suggest that the anti‐apoptotic gene expression profile of hybridoma cells can markedly impact on the beneficial effects afforded by nutrient supplementation. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 279–290, 2003.
Overexpression of a heterologous protein, haloalkane dehalogenase, in a poly‐β‐hydroxybutyrate‐deficient strain of the facultative methylotroph Methylobacterium extorquens AM1
Authors: Fitzgerald Kelly A. , Lidstrom Mary E. 
Published: December 2002

AbstractUsing an expression vector containing pmxaF, a strong native promoter, expression of a model heterologous protein, haloalkane dehalogenase, from Xanthobacter autotrophicus GJ10 was achieved in the methylotrophic bacterium, Methylobacterium extorquens AM1. Although expression using the wild‐type strain was <5% of total cell protein, expression at a level of 10% of the total cell protein was achieved in a mutant unable to synthesize poly‐β‐hydroxybutyrate granules. Two other tested heterologous proteins, catechol dioxygenase and green fluorescent protein, were expressed at moderate levels in both wild‐type and the PHB‐negative strain. These results suggest that the M. extorquens PHB‐negative strain is a possible platform for overexpression of heterologous proteins with labeled or unlabeled methanol as a starting material. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 263–268, 2003.
Study of caspase inhibitors for limiting death in mammalian cell culture
Authors: Sauerwald Tina M. , Oyler George A. , Betenbaugh Michael J. 
Published: December 2002

AbstractApoptosis in mammalian cell culture is associated with decreased bioproduct yields and can be inhibited through altering the intracellular signaling pathways mediating programmed cell death. In this study, we evaluated the capacity to inhibit caspases to maintain high viable cell numbers in CHO and 293 cultures. Two genetic caspase inhibitors, XIAP and CrmA, were examined along with a mutant of each, XIAP‐BIR123NC, which contains three BIR domains but lacks the RING finger, and CrmA‐DQMD, which has CrmA's pseudosubstrate site replaced with that of another caspase inhibitor, p35. Stable CHO pooled and 293 clonal cell lines expressing each protein were exposed to apoptotic insults, including spent medium, Sindbis virus, and etoposide. For each insult the mutated protein resulted in higher viabilities than its wild‐type counterpart. However, the mutants provided different levels of protection, depending on the insult considered. CrmA‐DQMD was the preferred inhibitor for spent medium‐induced apoptosis, whereas XIAP‐BIR123NC conferred better protection for etoposide‐induced death. Addition of Z‐VAD.fmk to the genetically engineered cells enhanced viabilities in the presence of spent medium or etoposide; however, the largest increases in viability were experienced by the control cells, indicating an overlap in caspase inhibition between the genetic and chemical inhibitors. Finally, parental 293 cells were treated with caspase‐8 and ‐9 inhibitors, Z‐IETD.fmk and Z‐LEHD.fmk, in concert with spent medium or etoposide exposure. Spent medium‐induced death was delayed more readily with the caspase‐8 inhibitors, CrmA‐DQMD and Z‐IETD.fmk, and etoposide‐induced death was stalled more so with XIAP‐BIR123NC and Z‐LEHD.fmk. These results suggest that the apoptosis pathways induced and the level of protection afforded by a particular caspase inhibitor may vary with the insult considered. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 329–340, 2003.
Physicochemical characterization and antimicrobial properties of rhamnolipids produced byPseudomonas aeruginosa47T2 NCBIM 40044
Authors: Haba E. , Pinazo A. , Jauregui O. , Espuny M. J. , Infante M. R. , Manresa A. 
Published: December 2002

AbstractPseudomonas aeruginosa47T2, grown in submerged culture with waste frying oil as a carbon source, produced a mixture of rhamnolipids with surface activity. Up to 11 rhamnolipid homologs (Rha‐Rha‐C8‐C10; Rha‐C10‐C8/Rha‐C8‐C10;Rha‐Rha‐C8‐C12:1; Rha‐Rha‐C10‐C10; Rha‐Rha‐C10‐C12:1; Rha‐C10‐C10; Rha‐Rha‐C10‐C12/Rha‐Rha‐C12‐C10; Rha‐C10‐C12:1/Rha‐C12:1‐C10; Rha‐Rha‐C12:1‐C12; Rha‐Rha‐C10‐C14:1; Rha‐C10‐C12/Rha‐C12‐C10) were isolated from cultures ofP. aeruginosa47T2 from waste frying oil and identified by HPLC‐MS analysis. This article deals with the production, isolation, and chemical characterization of the rhamnolipid mixture RL47T2. The physicochemical and biological properties of RL47T2as a new product were also studied. Its surface tension decreased to 32.8 mN/m; and the interfacial tension against kerosene to 1 mN/m. The critical micellar concentration for RL47T2was 108.8 mg/mL. The product showed excellent antimicrobial properties. Antimicrobial activity was evaluated according to the minimum inhibitory concentration (MIC), the lowest concentration of an antimicrobial agent that inhibits development of visible microbial growth. Low MIC values were found for bacteriaSerratia marcescens(4 μg/mL),Enterobacter aerogenes(8 μg/mL),Klebsiella pneumoniae(0.5 μg/mL),Staphylococcus aureusandStaphylococcus epidermidis(32 μg/mL),Bacillus subtilis(16 μg/mL), and phytopathogenic fungal species:Chaetonium globosum(64 μg/mL),Penicillium funiculosum(16 μg/mL),Gliocadium virens(32 μg/mL) andFusarium solani(75 μg/mL). © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 316–322, 2003.
Water‐in‐oil macroemulsions sustain long‐term viability of microbial cells in organic solvents
Authors: Stefan Alessandra , Palazzo Gerardo , Ceglie Andrea , Panzavolta Eleonora , Hochkoeppler Alejandro 
Published: December 2002

AbstractExtremely stable water‐in‐oil macroemulsions have been obtained by dispersing water in isooctane in the presence of lecithin. Either prokaryotic (Escherichia coli) and eukaryotic (Saccharomyces cerevisiae and Rhodotorula minuta) cells hosted in these water‐in‐oil macroemulsions are viable for weeks despite the consistent excess of organic solvent (ranging from 70 to 84%, v/v) in these ternary systems. Conjugation occurs upon mixing macroemulsions containing F+ or F− Escherichia coli strains, indicating consistent mass transfer between the water droplets. Populations of yeasts hosted in water‐in‐oil macroemulsion feature a higher frequency of cells aggregation when compared with the corresponding populations suspended in homogeneous aqueous media. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 323–328, 2003.
Pulsed feeding during fed‐batch fungal fermentation leads to reduced viscosity without detrimentally affecting protein expression
Authors: Bhargava Swapnil , Nandakumar M. P. , Roy Anindya , Wenger Kevin S. , Marten Mark R. 
Published: December 2002

AbstractThe goal in this study was to determine if pulsed addition of substrate could be used to alter filamentous fungal morphology during fermentation, to result in reduced broth viscosity. In all experiments, an industrially relevant strain of Aspergillus oryzae was grown in 20‐liter fermentors. As a control, cultures were fed limiting substrate (glucose) continuously. Tests were performed by altering the feeding strategy so that the same total amount of glucose was fed in repeated 300‐s cycles, with the feed pump on for either 30 or 150 s during each cycle. Variables indicative of cellular metabolic activity (biomass concentration, oxygen uptake rate, base consumed for pH control) showed no significant difference between continuous and pulse‐fed fermentations. In addition, there was no significant difference between total extracellular protein expression or the apparent distribution of these proteins. In contrast, fungal mycelia during the second half of pulse‐fed fermentations were approximately half the size (average projected area) of fungi during fermentations with continuous addition of glucose. As a result, broth viscosity during the second half of pulse‐fed fermentations was approximately half that during the second half of continuous fermentations. If these results prove to be applicable for other fungal strains and processes, then this method will represent a simple and inexpensive means to reduce viscosity during filamentous fungal fermentation. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 341–347, 2003.
Improved fuel cell and electrode designs for producing electricity from microbial degradation
Authors: Park Doo Hyun , Zeikus J. Gregory 
Published: December 2002

AbstractA new one‐compartment fuel cell was composed of a rubber bunged bottle with a center‐inserted anode and a window‐mounted cathode containing an internal, proton‐permeable porcelain layer. This fuel cell design was less expensive and more practical than the conventional two‐compartment system, which requires aeration and a ferricyanide solution in the cathode compartment. Three new electrodes containing bound electron mediators including a Mn4+‐graphite anode, a neutral red (NR) covalently linked woven graphite anode, and an Fe3+‐graphite cathode were developed that greatly enhanced electrical energy production (i.e., microbial electron transfer) over conventional graphite electrodes. The potentials of these electrodes measured by cyclic voltametry at pH 7.0 were (in volts): +0.493 (Fe3+‐graphite); +0.15 (Mn4+‐graphite); and −0.53 (NR‐woven graphite). The maximal electrical productivities obtained with sewage sludge as the biocatalyst and using a Mn4+‐graphite anode and a Fe3+‐graphite cathode were 14 mA current, 0.45 V potential, 1,750 mA/m2 current density, and 788 mW/m2 of power density. With Escherichia coli as the biocatalyst and using a Mn4+‐graphite anode and a Fe3+‐graphite cathode, the maximal electrical productivities obtained were 2.6 mA current, 0.28 V potential, 325 mA/m2 current density, and 91 mW/m2 of power density. These results show that the amount of electrical energy produced by microbial fuel cells can be increased 1,000‐fold by incorporating electron mediators into graphite electrodes. These results also imply that sewage sludge may contain unique electrophilic microbes that transfer electrons more readily than E. coli and that microbial fuel cells using the new Mn4+‐graphite anode and Fe3+‐graphite cathode may have commercial utility for producing low amounts of electrical power needed in remote locations. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 348–355, 2003.
Kinetic locking‐on and auxiliary tactics for bioaffinity purification of NADP+‐dependent dehydrogenases using N6‐linked immobilized NADP+ derivatives: Studies with mammalian and microbial glutamate dehydrogenases
Authors: McMahon Mary , Tynan Julie , Mulcahy Patricia 
Published: December 2002

AbstractThis study is concerned with the development and application of kinetic locking‐on and auxiliary tactics for bioaffinity purification of NADP+‐dependent dehydrogenases, specifically (1) the synthesis and characterization of highly substituted N6‐linked immobilized NADP+ derivatives using a rapid solid‐phase modular approach; (2) the evaluation of the N6‐linked immobilized NADP+ derivatives for use with the kinetic locking‐on strategy for bioaffinity purification of NADP+‐dependent dehydrogenases: Model bioaffinity chromatographic studies with glutamate dehydrogenase from bovine liver (GDH with dual cofactor specificity, EC 1.4.1.3) and glutamate dehydrogenase from Candida utilis (GDH which is NADP+‐specific, EC 1.4.1.4); (3) the selection of an effective “stripping ligand” for NADP+‐dehydrogenase bioaffinity purifications using N6‐linked immobilized NADP+ derivatives in the locking‐on mode; and (4) the application of the developed bioaffinity chromatographic system to the purification of C. utilis GDH from a crude cellular extract.Results confirm that the newly developed N6‐linked immobilized NADP+ derivatives are suitable for the one‐step bioaffinity purification of NADP+‐dependent GDH provided that they are used in the locking‐on mode, steps are taken to inhibit alkaline phosphatase activity in crude cellular extracts, and 2′,5′‐ADP is used as the stripping ligand during chromatography. The general principles described here are supported by a specific sample enzyme purification; the purification of C. utilis GDH to electrophoretic homogeneity in a single bioaffinity chromatographic step (specific activity, 9.12 μmol/min/mg; purification factor, 83.7; yield 88%). The potential for development of analogous bioaffinity systems for other NADP+‐dependent dehydrogenases is also discussed. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 356–369, 2003.
Testing for nandrolone metabolites in urine samples of professional athletes and sedentary subjects by GC/MS/MS analysis
Authors: Gambelunghe Cristiana , Sommavilla Marco , Rossi Ruggero 
Published: December 2002

AbstractThe concentrations of nandrolone metabolites, 19‐norandrosterone (19‐NA) and 19‐noretiocholanolone (19‐NE) were analysed in urine samples of professional athletes doing intense physical activity and sedentary subjects to verify if there was endogenous production of nandrolone and if there was any link between physical effort and the urinary metabolites of the steroid. We collected 18 urine samples from professional footballers age range 20–30 years, all from the same team, and 18 urine samples from males not doing any physical activity, age range 20–30 years. Neither group used nandrolone. Qualitative and quantitative analyses of urinary nandrolone metabolites were carried out by GC/MS followed by GC/MS/MS to confirm positive samples. This technique has been demostrated to be an excellent analytical approach for the determination of anabolic steroids at very low detection limits in complex matrices such as urine. In five urine samples from professional footballers traces of 19‐NA were detected. No trace of 19‐NA was found in the group of sedentary subjects and no trace of 19‐NE was found in any urine sample. The absence of nandrolone metabolites in sedentary subjects supports the hypothesis that the presence of 19‐NA and 19‐NE could be linked to physical effort even though the origin is not yet clear. Copyright © 2002 John Wiley & Sons, Ltd.
Screening for 18 diuretics and probenecid in doping analysis by liquid chromatography–tandem mass spectrometry
Authors: Deventer K. , Delbeke F. T. , Roels K. , Van Eenoo P. 
Published: December 2002

AbstractA fast and selective liquid chromatography–tandem mass spectrometric (LC/MS/MS) method for the screening of 18 diuretics and probenecid in human urine is presented. Analyses were performed on a LCQ‐Deca® instrument equipped with ESI‐interface using scan by scan polarity changing. All diuretics and probenecid were separated in less than 20 min after liquid–liquid extraction with ethyl acetate. The LOD for all substances was 100 ng/mL or better. The method was applied to detect diuretics after the oral administration of several drugs including hydrochlorothiazide, bumetanide, spironolactone, furosemide, amiloride, triamterene, chlortalidone and epithizide. All diuretics could be detected for periods up to 96 h after the intake of therapeutic amounts. Copyright © 2002 John Wiley & Sons, Ltd.
Rat liver and kidney catechol‐O‐methyltransferase activity measured by high‐performance liquid chromatography with fluorescence detection
Authors: Tsunoda Makoto , Takezawa Kazuko , Masuda Mayumi , Imai Kazuhiro 
Published: December 2002

AbstractWe have previously reported a highly sensitive method for the measurement of catechol‐O‐methyltransferase (COMT) activities in rat erythrocytes with norepinephrine (NE), an endogenous native substrate, using high‐performance liquid chromatography (HPLC)‐fluorescence or peroxyoxalate chemiluminescence reaction detection. Applying this method to COMT activities in rat liver and kidney, known to have the highest activities of all organs, the optimum reaction conditions were investigated. Under the optimum conditions, soluble (S)‐COMT and membrane‐bound (MB)‐COMT activities in rat liver, with NE as a substrate, were 2.17 ± 0.33 and 0.16 ± 0.02 nmol/min/mg protein (n = 5), respectively. In rat kidney, S‐COMT and MB‐COMT activities were 1.81 ± 0.20 and 0.079 ± 0.009 nmol/min/mg protein (n = 5), respectively. Since liver and kidney play important roles in inactivating catecholamines, using the proposed method would yield critical information to delineate the role of metabolism of catecholamines in rat tissues. Copyright © 2002 John Wiley & Sons, Ltd.