bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significance of absorption, oxidation, and binding to toxicity of four ecdysone agonists in multi‐resistant cotton leafworm
Authors: Smagghe Guy , Carton Bert , Decombel Luc , Tirry Luc 
Published: August 2002

AbstractTreatment of last‐instar larvae of multi‐resistant cotton leafworm Spodoptera littoralis with four dibenzoylhydrazines, methoxyfenozide (RH‐2485), tebufenozide (RH‐5992), halofenozide (RH‐0345), and RH‐5849, resulted in premature molting leading to death. Methoxyfenozide was the most toxic followed by tebufenozide, halofenozide, and RH‐5849. To explain differences in toxicity, especially between multi‐resistant and laboratory strains, absorption in the body tissues and oxidative metabolism were tested with 14C‐labeled ecdysone agonist and a Lineweaver‐Burk assay, respectively. Then to address different compound potencies in multi‐resistant strains, the potency of the four ecdysone agonists was measured based on their ability to mimic the natural insect molting hormone, 20‐hydroxyecdysone (20E) by inducing evagination in isolated imaginal wing discs. Using monoclonal antibody 9B9, the presence of ecdysteroid receptors in imaginal discs in vitro was confirmed. In parallel, Scatchard plot analysis with whole imaginal wing discs cultured with different concentrations of 3H‐labeled ponasterone A indicated no significant difference in affinity and in number of target sites for binding between multi‐resistant and susceptible laboratory strains. The four compounds tested caused the effect as agonists of 20E in vitro, and typically the order of their toxicities (LC50s) corresponded with that for evagination‐induction with whole imaginal discs. Arch. Insect Biochem. Physiol. 46:127–139, 2001. © 2001 Wiley‐Liss, Inc.
Assessment of the gene expression profile of differentiated and dedifferentiated human fetal chondrocytes by microarray analysis
Authors: Stokes David G. , Liu Gang , Coimbra Ibsen B. , Piera‐Velazquez Sonsoles , Crowl Robert M. , Jiménez Sergio A. 
Published: August 2002

AbstractObjectiveTo study the changes in patterns of gene expression exhibited by human chondrocytes as they dedifferentiate into fibroblastic cells in culture in order to better understand the mechanisms that control this process and its relationship to the phenotypic changes that occur in chondrocytes during the development of osteoarthritis (OA).MethodsHuman fetal epiphyseal chondrocytes (HFCs) were cultured either on poly‐(2‐hydroxyethyl methacrylate)–coated plates (differentiated HFC cultures) or in plastic tissue culture flasks as monolayers (dedifferentiated HFC cultures). Following 11 days of culture under either condition, poly(A+) RNA was isolated from the two cell populations and subjected to a gene expression analysis using a microarray containing ∼5,000 known human genes and ∼3,000 expressed sequence tags (ESTs).ResultsA ≥2‐fold difference in the expression of 62 known genes and 6 ESTs was observed between the two cell types. The differences in expression of several of the genes detected by the microarray hybridization were confirmed by Northern analyses. Two transcription factor genes, TWIST and HIF‐1α, and a cellular adhesion protein gene, cadherin 11, were markedly regulated in response to differentiation and dedifferentiation. Expression of these genes was also detected in adult normal and OA cartilage and chondrocytes. Analysis of the gene expression profile of HFCs revealed a complex pattern of gene expression, including many genes not yet reported to be expressed by chondrocytes.ConclusionChondrocytes in monolayer become dedifferentiated, acquiring a fibroblast‐like appearance and changing their pattern of gene expression from one of expression of chondrocyte‐specific genes to one that resembles a fibroblastic or chondroprogenitor‐like pattern. Changes in gene expression associated with the process of dedifferentiation of HFCs in vitro were observed in a wide variety of genes, including genes encoding extracellular matrix proteins, transcription factors, and growth factors. At least 3 of the genes that were regulated in response to dedifferentiation were also found to be expressed in adult normal and OA articular cartilage and chondrocytes.
Reduction of the dimension of a document space using the fuzzified output of a Kohonen network
Authors: Guerrero Vicente P. , de Moya Anegón Félix 
Published: August 2002

AbstractThe vectors used in IR, whether to represent the documents or the terms, are high dimensional, and their dimensions increase as one approaches real problems. The algorithms used to manipulate them, however, consume enormously increasing amounts of computational capacity as the said dimension grows. We used the Kohonen algorithm and a fuzzification module to perform a fuzzy clustering of the terms. The degrees of membership obtained were used to represent the terms and, by extension, the documents, yielding a smaller number of components but still endowed with meaning. To test the results, we use a topological classification of sets of transformed and untransformed vectors to check that the same structure underlies both.
A simulation environment for discontinuous portfolio value processes
Authors: Consigli Giorgio , Di Cesare Antonio 
Published: August 2002

AbstractWe present a simulation‐based approach to the estimation of portfolio's Value‐at‐Risk – VaR—, based on the definition of a jump‐diffusion continuous time process driven by Wiener and Poisson uncertainty. We introduce to this end a novel characterization of the intensity rate of the Poisson process, modelling the arrival of shocks to the market, as a function of a credit spread curve estimated in high‐risk emerging bond markets. The procedure is described and tested on the August 1998 Russian crisis whose impact on liquid equity markets is also estimated. Copyright © 2001 John Wiley & Sons, Ltd.
Implementation and performance of various stochastic models for interest rate derivatives
Authors: Rapisarda Francesco , Silvotti Roberto 
Published: August 2002

AbstractThe arbitrage free market framework of Heath, Jarrow and Morton provides a mathematical scheme according to which the valuation of all interest rate derivatives depend on two kinds of basic parameters: the discount function and the (generally stochastic) volatilities of zero coupon bonds of all maturities. Among the models in this class, Flesaker‐Hughston's rational lognormal model stands out for naturality and simplicity while incorporating positivity of interest rates: all fundamental processes (short rate, discount and zero‐coupon bonds) are parametrized as rational functions of an exponential martingale. Its practical implementation presents, however, a few subtle aspects. We discuss its numerical implementation with special attention to issues of fitting and calibration, and pricing of exotic options. A comparison with other standard models such as Hull‐White and Black‐Karasinki will be presented in test cases. Copyright © 2001 John Wiley & Sons, Ltd.
Three repair strategies
Authors: Rocha‐Martínez José M. 
Published: August 2002

AbstractThree imperfect repair strategies, derived from a discrete‐time model of failure and repair, are implemented on items brand A (car, computer, washer, etc.), which are low quality with respect to equivalent items brand B (the leading brand in the market) in the sense that items brand A usually fail faster than items brand B do, in order to increase their lifetimes so that they have a chance to compete in durability against items brand B. The implementation of those strategies is performed by probabilistic simulations of the model. The effectiveness of these strategies is measured by comparing the expected ‘output’ lifetimes of items brand A under each strategy with respect to the expected lifetime of items brand B and the mean value of the total number of repair actions required on items brand A under one strategy with respect to the other two. The algorithm for designing a computer program for simulating those strategies is included. Some results concerning a relationship between a generalized memoryless property of geometric (exponential) distributions and the convolution property of probability (moment) generating functions are detected and also included. Copyright © 2001 John Wiley & Sons, Ltd.
Maintenance policy for multivariate standby/operating units
Authors: Badía F. G. , Berrade M. D. , Campos Clemente A. 
Published: August 2002

AbstractIn this paper the maintenance of multi‐component systems, which may be either in operating condition or in the standby mode is studied. A less than perfect testing procedure to detect failures in the latter case is considered. We focus on the existence of an optimum policy weighing the cost incurred under this policy against the cost derived from an undetected failure. Copyright © 2002 John Wiley & Sons, Ltd.
Pharmacokinetics of dicrofenac after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction
Authors: Nagasawa Kazuki , Nakanishi Hirokazu , Matsuda Tomoko , Takara Kohji , Ohnishi Noriaki , Yokoyama Teruyoshi , Fujimoto Sadaki 
Published: August 2002

AbstractWe investigated the pharmacokinetics of diclofenac, one of the important analgesics in palliative care, after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction. In rectal‐resected rabbits, its bioavailability after rectal administration was significantly lower than that in normal rabbits, and furthermore that after intracolostomal administration was significantly lower than that in rectal‐resected rabbits. This decreased bioavailability in rabbits with rectal resection and colostoma construction was thought to be due to the increased first‐pass effect. With increase in the dose up to 1.5‐fold, the plasma concentrations in both rectal‐resected and colostoma‐constructed rabbits increased to the normal rabbit level. These results indicate that the bioavailability of diclofenac sodium after its rectal and intracolostomal administration decreases, and that an increased dose can restore the decreased plasma concentration. There was no difference in the plasma concentration with diclofenac sodium suppositories between administration into the normal rectum and the remaining rectum following colostoma construction, and the remaining rectum was found to be a useful administration route for suppositories. Therefore, it was indicated that when administering diclofenac sodium suppositories to rectal‐resected and colostoma‐constructed patients, the dose should be increased, because the pharmacokinetics of diclofenac was similar in rabbits and human. Copyright © 2001 John Wiley & Sons, Ltd.
Stereoselective halofantrine and desbutylhalofantrine disposition in the rat: cardiac and plasma concentrations and plasma protein binding
Authors: Brocks Dion R. 
Published: August 2002

AbstractHalofantrine (HF) is a chiral antimalarial drug known to cause cardiac arrhythmias in susceptible patients. In this study, the cardiac uptake and plasma protein binding of HF and desbutylhalofantrine (DHF) enantiomers were examined in the rat. Rats were given 2 mg/kg of either HF HCl or DHF HCl intravenously, then sacrificed at various times after dosing. Specimens were assayed using stereospecific methods. Uptake of HF and DHF enantiomers into heart was rapid. Substantial concentrations of both HF and DHF enantiomers were observed in rat heart, with stereoselectivity being noted for both in plasma and heart. Stereoselectivity was more pronounced for HF (AUC (+):(−) ratio= 1.58) than DHF (AUC (+):(−) ratio =1.16) in heart tissue. Heart:plasma AUC ratios of 6.8–8.0, and 9.3–21, were observed for HF and DHF enantiomers, respectively, indicating that DHF has greater cardiac uptake than HF itself. Plasma protein binding was extensive for both HF and DHF (>99.95%), and was stereoselective for DHF, with a 38% higher unbound fraction for (−)‐DHF than antipode. In contrast, binding of HF enantiomers was nonstereoselective. The lower degree of stereoselectivity for DHF in heart tissues was attributable to its greater stereoselectivity in plasma protein binding. Copyright © 2002 John Wiley & Sons, Ltd.
Disposition of radiolabeled BMS‐204352 in rats and dogs
Authors: Krishna Rajesh , Yao Ming , Srinivas Nuggehally R. , Shah Vinod , Pursley Janice M. , Arnold Mark , Vachharajani Nimish N. 
Published: August 2002

AbstractBMS‐204352, a maxi‐K channel opener, is currently under development for the treatment of stroke. The objective of this study was to determine the pharmacokinetics, mass balance and absolute oral bioavailability of [14C]‐BMS‐204352 in rats and dogs. [14C]‐BMS‐204352 was administered, to rats (n=10/group; parallel design, 6 mg/kg) and dogs (n=4/group; crossover design, 2 mg/kg), as an oral (PO) or as a 3‐min intraarterial (IA) infusion in rats and a 6‐min intravenous (IV) infusion in dogs. Blood, urine, and feces samples were collected and analyzed for unchanged BMS‐204352 (plasma) using a validated LC/MS assay and for total radioactivity (plasma, urine, feces) using liquid scintillation counting. The mean total body clearance (CLT) and steady‐state volume of distribution (VSS) values for the unchanged BMS‐204352 were 2.58±0.48 l/h/kg and 6.3±1.14 l/kg, respectively, in rats and 0.21±0.02 l/h/kg and 4.06±0.47 l/kg, respectively, in dogs. In both species, the elimination half‐life of total radioactivity was significantly longer as compared to the unchanged drug. After IA administration of radiolabeled BMS‐204352 to rats, ca. 5.9 and 85% of radioactivity was recovered within 7 days in urine and feces, respectively; corresponding recoveries after PO dosing were 4.5 and 99.5%, respectively. The recoveries were similar in dogs, i.e., ca. 5.2 and 83% of administered radioactivity recovered in urine and feces, respectively, for IV dose and ca. 4 and 86%, respectively, for PO dose. These data indicate that nonrenal (biliary) elimination in both species was predominant. Based on comparable urinary recovery of radioactivity and plasma AUCs of radioactivity, the extent of oral absorption of BMS‐204352 appeared to be complete in both species. The absolute oral bioavailability was 55% in rats and 79% in dogs. Bioavailability and extent of absorption data suggest evidence of first pass metabolism of BMS‐204352 in the rat and dog. Copyright © 2002 John Wiley & Sons, Ltd.
Action, inaction, and factors influencing perceived decision making
Authors: Niedermayer Laura Y. , Chapman Gretchen B. 
Published: August 2002

AbstractTwo studies examined factors hypothesized to be related to the subjective perception of decision making. A total of 302 introductory psychology students read four hypothetical scenarios that varied on two dimensions: frequency of the behavior and whether the behavior was an action or an inaction (a 2 × 2 design). Subjects rated the scenarios on whether the actor made a decision. In Experiment 1, the frequency of behavior was unrelated to decision making. In addition, actions were given higher decision ratings than inactions in two scenarios, but lower ratings in the other two scenarios. In Experiment 2 the latter discrepancy was explained by ratings of whether the actor behaved thoughtfully rather than reflexively, in that these ratings mediated the action–decision rating relationship. Copyright © 2001 John Wiley & Sons, Ltd.
Why arguments based on photon energy may be highly misleading for power line frequency electromagnetic fields
Authors: Vistnes Arnt Inge , Gjötterud Kristoffer 
Published: August 2002

AbstractWhen evaluating possible mechanisms by which low frequency electromagnetic fields may have a biological effect, arguments based on photon energy have often been used in a misleading way. For visible light the concept of photons has proved to be very useful in explaining experimental findings. However, the concept of photons cannot be used without major modifications in describing phenomena related to near field problems at power frequency (50 or 60 Hz) electric and magnetic fields. For this regime, the photon description is very complex. A very high number of highly coherent photons must be used in a quantum electrodynamic description of low frequency electromagnetic field phenomena. Thus, one‐photon interaction descriptions must be replaced by multiple‐photon interaction formalism. However, at low frequencies, a classical electromagnetic field description is far more useful than quantum electrodynamics. There is in principle no difference in how much energy an electron can pick up from a low frequency electric field as compared to from a high frequency photon. Thus, the total gain in energy is not limited to the energy carried by a single photon, which is E = hν, where h is Planck's constant and ν is the frequency of the radiation. However, the time scale of the primary event in a mechanism of action is very different for ionizing radiation compared to power line frequency fields. The advice is to consider the time scale given by the inverse of the frequency of the fields, rather than photon energy, when one use physics as a guidance in evaluating possible mechanisms for biological effects from low frequency electromagnetic fields. Bioelectromagnetics 22:200–204, 2001. © 2001 Wiley‐Liss, Inc.
Effect of a permanent magnetic field on wing size parameters inDrosophila melanogaster
Authors: Stamenković‐Radak Marina , Kitanović Igor , Prolić Zlatko , Tomišić Ivana , Stojković Biljana , Andjelkovic Marko 
Published: August 2002

AbstractThe width and length variability of bothD. melanogasterwings were measured in samples of flies after two and six generations under a permanent magnetic field of 35 mT. While in earlier generations under exposure sexes differ in the size response, later they both show a decrease in the wing size under the magnetic field exposure if compared to the control. The bilateral asymmetry in wings as a potential indicator of developmental instability does not increase significantly under exposure. The ecological and adaptive implications of the change of the magnetic intensity as an environmental factor generating stress in populations is discussed. Bioelectromagnetics 22:365–369, 2001. © 2001 Wiley‐Liss, Inc.
Fat facets does a Highwire act at the synapse
Authors: Fischer Janice A. , Overstreet Erin 
Published: August 2002

AbstractNeuromuscular synapses are highly dynamic structures that respond to both intercellular and intracellular cues to manipulate synaptic form. A variety of post‐translational modifications of synaptic proteins are used to regulate synaptic plasticity. A recent report by DiAntonio et al.(1) shows that two ubiquitin pathway proteins, Highwire and Fat facets, may be mutually antagonistic regulators of presynaptic growth at the Drosophila neuromuscular junction. This work adds support to the emerging idea that ubiquitin, a polypeptide that targets proteins for proteasomal degradation, regulates synaptic development. BioEssays 24:13–16, 2002. © 2002 John Wiley & Sons, Inc.
Branch‐specific migration cues in the Drosophila tracheal system
Authors: Rosin Dalia , Shilo Ben‐Zion 
Published: August 2002

AbstractThe Drosophila tracheal system forms by highly stereotyped migration of the tracheal cells, generating an elaborate network of interconnected tubes supplying oxygen to all tissues. A major guiding system in the migration process of all branches is the dynamic and localized expression of Branchless (Bnl), an FGF‐like molecule. Bnl triggers the activation of the FGF receptor Breathless (Btl) locally in all tracheal cells. Is this the only guiding cue, or do additional local signals provide distinct inputs to each branch? Several recent papers identify such local signals, relying on contacts with specific cell types and with the matrix encountered by the migrating tracheal branches. In particular, the paper by Boube et al(1) demonstrates a role for PS integrins in promoting migration of a specific tracheal branch. BioEssays 24:110–113, 2002. © 2002 Wiley Periodicals, Inc.
Microevolutionary studies in nematodes: a beginning
Authors: Delattre Marie , Félix Marie‐Anne 
Published: August 2002

AbstractComparisons between related species often allow the detailed genetic analysis of evolutionary processes. Here we advocate the use of the nematode Caenorhabditis elegans (and several other rhabditid species) as model systems for microevolutionary studies. Compared to Drosophila species, which have been a mainstay of such studies, C. elegans has a self‐fertilizing mode of reproduction, a shorter life cycle and a convenient cell‐level analysis of phenotypic variation. Data concerning its population genetics and ecology are still scarce, however. We review molecular, behavioral and developmental intraspecific polymorphisms for populations of C. elegans, Oscheius sp. 1 and Pristionchus pacificus. Focusing on vulval development, which has been well characterized in several species, we discuss relationships between patterns of variations: (1) for a given genotype (developmental variants), (2) after mutagenesis (mutability), (3) in different populations of the same species (polymorphisms) and (4) between closely related species. These studies have revealed that evolutionary variations between sister species affect those characters that show phenotypic developmental variants, that are mutable and that are polymorphic within species. BioEssays 23:807–819, 2001. © 2001 John Wiley & Sons, Inc.
Increase in the intensity of thermoluminescence Q‐band during leaf ageing is due to a block in the electron transfer from QA to QB
Authors: Biswal A. K. , Dilnawaz F. , David K. A. V. , Ramaswamy N. K. , Misra A. N. 
Published: August 2002

AbstractThe thermoluminescence (TL) parameters in intact leaves and thylakoids isolated from leaves showed a different pattern of change during leaf ageing. Ageing of leaves brought about a decrease in the B‐band and a simultaneous increase in the Q‐band. Thylakoids showed only a decrease in the B‐band. The TL bands further show that there is generation of an endogenous electron transport inhibitor during leaf ageing. Copyright © 2001 John Wiley & Sons, Ltd.