bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature and magnetic field dependence of radiation‐induced magnetoresistance oscillations in a 2D electron gas
Authors: Iñarrea J. , Platero G. 
Published: March 2006

AbstractA theoretical model is presented in which the existence of radiation‐induced zero‐resistance states is analyzed. An exact solution for the harmonic oscillator wave function in the presence of radiation, and a perturbation treatment for elastic scattering due to randomly distributed charged impurities, form the foundations of our model. Following this model most experimental results are reproduced. The existence of zero‐resistance states is thus explained in terms of the interplay of the electron MW‐driven orbit dynamics and the Pauli exclusion principle. In order to explain the strong temperature dependence of the longitudinal resistivity and the thermally activated transport in 2DEG, we present also a model based on the damping suffered by the microwave‐driven electronic orbit dynamics by interactions with the lattice ions yielding acoustic phonons. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational study of some benzamidine‐based inhibitors of thrombin‐like snake venom proteinases
Authors: Henriques Elsa S. , Nascimento Marco A. C. , Ramos Maria João 
Published: March 2006

AbstractPit viper venoms contain a number of serine proteinases that, despite their observed coagulant thrombin‐like action in vitro, exhibit a paradoxical benign defibrinogenating (anticoagulant) action in vivo, with clinical applications in preventing thrombi and improved blood circulation. Considering that several benzamidine‐based inhibitors, some highly selective to thrombin, also inhibit the enzymatic activity of such venombins, the modeling of their enzyme–inhibitor interactions could provide valuable information on the topological factors that determine the divergences in activity. The first step, and the object of the present study, was to derive the necessary set of parameters, consistent with the CHARMM force field, and to perform molecular dynamics (MD) simulations on a few selected representatives of the inhibitors in question under physiological conditions. Bonding and van der Waals parameters were derived by analogy to similar ones in the existing force field. Net atomic charges were obtained with a restrained fitting to the molecular electrostatic potential generated at B3LYP/6‐31G(d) level. The parameters were refined to reproduce the available experimental geometries and crystal data, and the MD simulations of the free inhibitors in aqueous solution at 298 K provided an insightful description of their available conformational space. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Faults‐slip‐through—a concept for measuring the efficiency of the test process
Authors: Damm Lars‐Ola , Lundberg Lars , Wohlin Claes 
Published: March 2006

AbstractIn market‐driven development where time‐to‐market is of crucial importance, software development companies seek improvements that can decrease the lead‐time and improve the delivery precision. One way to achieve this is by analyzing the test process since rework commonly accounts for more than half of the development time. A large reason for high rework costs is fault slippages from earlier phases where they are cheaper to find and remove. As an input to improvements, this article introduces a measure that can quantify this relationship. That is, a measure called faults‐slip‐through, which determines the faults that would have been more cost‐effective to find in an earlier phase. The method presented in this article also determines the excessive costs of the faults that slipped through phases, i.e. the improvement potential. The method was validated through practical application in two software development projects at the telecom company Ericsson AB. The results of the case study determined that the implementation phase had the largest improvement potential in the two studied projects since it caused a large faults‐slip‐through to later phases, i.e. 85 and 86% of the total improvement potential of each project. Copyright © 2006 John Wiley & Sons, Ltd.
Nonlinear analysis for performance‐based earthquake engineering
Authors: Moehle Jack P. 
Published: March 2006

AbstractEarthquake engineering design of buildings increasingly is using nonlinear dynamic analysis procedures to demonstrate building performance. These procedures require: an understanding of the relation between performance and nonlinear modeling; selection and manipulation of ground motions appropriate to design hazard levels; selection of appropriate nonlinear models and analysis procedures; and interpretation of results to determine design quantities based on nonlinear dynamic analysis procedures. These topics are discussed with an emphasis on tall buildings. Copyright © 2005 John Wiley & Sons, Ltd.
The case for seismic superiority of well‐engineered tall buildings
Authors: Naeim Farzad , Graves Robert W. 
Published: March 2006

AbstractThe objective of this paper is to bring the lingering debate over whether more rigid or more flexible buildings fare better during major earthquakes to an end. Historical data, design experience, and ground motions obtained from simulation of a magnitude 7·1 blind fault rupture directly below downtown Los Angeles are utilized in this study. Assuming the same level of attention to design, detailing, and construction workmanship is applied to buildings of all heights resulting in well‐engineered buildings, the results indicate that well‐engineered tall buildings are substantially safer than shorter, stiffer, buildings when subjected to strong earthquake ground motions. This is true even in the case of strong ground motions containing significant directivity and near‐source velocity pulses. Copyright © 2005 John Wiley & Sons, Ltd.
Clinical gait and stepping performance measures in older adults
Authors: Alexander N. B. , Goldberg A. 
Published: March 2006

AbstractProblems with ambulation and mobility are frequent problems in older adults. Each year, about one in 100 older adults develops new severe mobility disability. Assessment of abnormal gait constitutes a major component of clinical practice and may lead to fall reduction. Clinicians can benefit from simple gait and mobility assessment tools to be used in busy clinical settings. This review focuses on gait and stepping performance measures that can be used by the busy clinician to assess gait, mobility performance, balance, and falls risk in the older adult.
Disability and physical activity in late life—research models and approaches
Authors: Heikkinen E. 
Published: March 2006

Abstract
Prevention of disability in late life has become a major public health concern, a key area of ageing research, and also an important target for the development of effective interventions. The increase in life expectancy and the resulting growth of the elderly population are also thought to be driving up the number of elderly people with disabilities. Despite the message that regular moderate physical activity has substantial health benefits even in very old age, older people remain largely sedentary. The most popular theoretical model for researching the development of disability is the disablement process, which is widely used, in the gerontological literature. The main pathway according to this model leads from diseases and injuries to impairments, functional limitations, and disability. This approach has been challenged most particularly by models, which emphasize the social construction and determinants of disability. Numerous physical exercise interventions have aimed at preventing impairments, functional limitations and disability, and at promoting independent living in late life. A review of the results of these interventions shows that exercise can indeed be effective in preventing impairments and functional limitations, but the evidence regarding the prevention of disability and dependency is inconclusive. The inconsistency of the results is related to differences in research models and approaches, cultural and other differences between the populations studied, and variability in research designs and methods, including definitions of key variables. In the future, research-addressing disability in late life needs to focus on the dynamic interactions between individuals and their social, physical, and cultural environment. Furthermore, randomized trials that are larger and longer than most existing studies of physical activity need to be conducted. Additional evidence can also be obtained by well-conducted observational studies focusing on the prevention of progressive disability related to chronic conditions. One of the key areas of development is in improving the definition of both independent (physical activity and exercise) and outcome (functional limitations, disability) variables. A further challenge is presented by the investigation of dose–response relationships, including both beneficial and possible adverse effects of exercise.
N‐Acetylcysteine‐induced changes in susceptibility of transformed eukaryotic cells to bacterial invasion
Authors: Gamaley Irina , Efremova Tatiana , Kirpichnikova Ksenia , Kever Ludmila , Komissarchik Yan , Polozov Yuri , Khaitlina Sofia 
Published: March 2006

AbstractThe effect of N‐acetylcysteine (NAC) on morphological and physiological properties of “normal” 3T3 and 3T3‐SV40 fibroblasts was studied. Incubation of the cells with 10 and 20 mM NAC for 20 h resulted in a reversible increase in the intracellular level of reduced glutathione and disorganization of actin cytoskeleton. Surprisingly, upon removal of NAC, 3T3‐SV40 fibroblasts demonstrated formation of well‐adhered cells with structured 3T3‐like stress‐fibers. Neither changes in glutathione levels, nor cytoskeleton disorganization/assembly abolished resistance of 3T3 cells to invasion by the bacterium Escherichia coli A2. On the other hand, pretreatment with NAC converted bacteria‐susceptible 3T3‐SV40 cells into resistant ones. These results show that NAC can induce partial reversion of transformed phenotype. We suggest that this effect is due to NAC‐induced modifications of cell surface proteins rather than to changes in the level of intracellular glutathione.
Psychological stress and the severity of post‐inflammatory visceral hyperalgesia
Authors: Liebregts Tobias , Adam Birgit , Bertel Anton , Lackner Carolin , Neumann Jens , Talley Nicholas J. , Gerken Guido , Holtmann Gerald 
Published: March 2006

AbstractObjectives: Lowered visceral sensory thresholds are a key finding in at least a subgroup of patients with functional bowel disorders. Stress and inflammation contribute to this altered visceral sensory function. We aimed to elucidate the role of repetitive stress and acute mucosal inflammation, alone and in combination, on sensory function.Methods: In randomized order, trinitrobenzenesulfonic acid (TNBS) plus the equal amount of ethanol or saline were instilled into the colorectum of female Lewis rats. Colorectal distensions (CRD) were performed with a barostat device (3min/40mmHg); to quantify the visceromotor response (VMR) to CRD, electromyographic activity (EMG) of the abdominal muscles was recorded. In randomized order, equal numbers of both treatment groups underwent either seven days (1h/day) repetitive water avoidance stress (WAS) or sham WAS. CRD's were conducted 28 days later. Colonic tissue samples were obtained to characterize inflammation and blood samples were taken at day 28 to measure plasma IL‐2 levels by enzyme‐linked immunosorbent assay (ELISA).Results: Compared to controls (662±114μV) TNBS (1081±227μV), WAS (1366±125μV) and the combination of both (1477±390μV) significantly augmented the VMR to CRD. TNBS and/or WAS caused significant inflammatory changes at day 5, while only TNBS+WAS also showed signs of mucosal inflammation on day 14 and significantly elevated IL‐2 levels on day 28.Conclusions: Stress and inflammation cause long lasting alterations of visceral sensory function. Concomitant stress further increases post‐inflammatory visceral hyperalgesia.
Synergistic interactions between the dual serotonergic, noradrenergic reuptake inhibitor duloxetine and the non‐steroidal anti‐inflammatory drug ibuprofen in inflammatory pain in rodents
Authors: Jones Carrie K. , Peters Steven C. , Shannon Harlan E. 
Published: March 2006

AbstractObjectives:The present study was undertaken to characterize whether the pharmacologic interaction between duloxetine, a balanced serotonergic and noradrenergic reuptake inhibitor, and the non‐steroidal anti‐inflammatory drug ibuprofen was simply additive, less than additive, or greater than additive (i.e., synergistic) in preclinical models of visceral and inflammatory pain, specifically acetic acid‐induced writhing in mice and carrageenan‐induced thermal hyperalgesia and mechanical allodynia in rats.Methods:In the writhing test, male CF‐1 mice were injected intraperitoneally with 0.55% acetic acid and 5min later the number of writhes was counted over a 5‐min period. In the carrageenan models, male Sprague‐Dawley rats were injected with a 1.5% carrageenan solution into the ventral surface of the hind paw; hypersensitivity to thermal and mechanical stimuli was subsequently evaluated 2h post‐carrageenan.Results:Vehicle or a dose of duloxetine alone (1–100mg/kg), ibuprofen alone (10–300mg/kg), or duloxetine and ibuprofen in combination in a dose‐ratio of 1:10 duloxetine:ibuprofen were orally administered 30 or 60min before testing. Isobolographic analysis of the effects of duloxetine in combination with ibuprofen revealed a significant synergistic (greater than additive) interaction between duloxetine and ibuprofen both for reducing acetic acid‐induced writhing and carrageenan‐induced thermal hyperalgesia, but were additive for reversing mechanical allodynia.Conclusions:Our data indicate that duloxetine and ibuprofen have synergistic efficacy in a visceral and an inflammatory pain model in rodents, and suggest that duloxetine and ibuprofen in combination may provide a useful approach to the clinical treatment of persistent pain, particularly inflammation‐related pain.
Source monitoring deficits in hallucinating compared to non-hallucinating patients with schizophrenia
Authors: Brunelin Jerome , Combris Marion , Poulet Emmanuel , Kallel Lassad , D’Amato Thierry , Dalery Jean , Saoud Mohamed 
Published: March 2006

AbstractIn two source memory tests, hallucinating patients with schizophrenia (N = 30), compared to non-hallucinating (N = 31), are impaired in recognizing internal self-generated items and misattribute them to an external event. They are not impaired in recognizing events from two internal sources. Results support a selective source-monitoring deficit in the occurrence of auditory hallucinations.
Hyperhomocysteinemia increases damage on brain slices exposed to in vitro model of oxygen and glucose deprivation: prevention by folic acid
Authors: Tagliari Bárbara , Zamin Lauren L. , Salbego Christianne G. , Netto Carlos Alexandre , Wyse Angela T.S. 
Published: March 2006

AbstractIn the present study we evaluate the effects of homocysteine on cellular damage using hippocampal slices from Wistar rats exposed to oxygen and glucose deprivation (OGD, followed by reoxygenation), an in vitro model of hypoxic–ischemic events. For chronic treatment, we induced elevated levels of homocysteine in blood (500 μM), comparable to those of human homocystinuria, and in brain (60 nmol/g wet tissue) of young rats by subcutaneous injections of homocysteine (0.3–0.6 μmol/g of body weight), twice a day with 8 h intervals, from the 6th to the 28th postpartum day and controls received saline. Rats were sacrificed 1, 3 or 12 h after the last injection. For acute treatment, 29‐day‐old rats received one single injection of homocysteine (0.6 μmol homocysteine/g body weight) or saline and were sacrificed 1 h later. In another set of experiments rats were pretreated with Vitamins E (40 mg/kg) and C (100 mg/kg) or folic acid (5 mg/kg) during 1 week; 12 h after the last administration they received a single injection of homocysteine or saline and were sacrificed 1 h later. Results showed that both chronic (1 h after homocysteine administration) and acute hyperhomocysteinemia increased the cellular damage measured by LDH released to de incubation medium, suggesting an increase of tissue damage caused by OGD. Pretreatment with folic acid completely prevented the damage caused by acute hyperhomocysteinemia, whereas Vitamin E just partially prevented such effect. These findings may be relevant to explain, at least in part, the higher susceptibility of hyperhomocysteinemic patients to be susceptible to ischemic events and point to a possible preventive treatment.
Examining the effects of contextual factors on TQM and performance through the lens of organizational theories: An empirical study
Authors: Sila Ismail 
Published: March 2006

AbstractAlthough much has been written about TQM, little attention has been paid to the potential effects of contextual factors on TQM and TQM–performance relationships. The use of organizational theory to formulate propositions regarding the effects of such factors is especially scarce in the TQM literature. This study uses institutional theory and contingency theory as the basis to test a number of such propositions. First, a model of TQM and organizational performance is developed. Then using survey data, the effects of five contextual factors – three institutional factors and two contingency factors – on the implementation of TQM practices and on the impact of TQM on key organizational performance measures are analyzed within a TQM–performance relationships model framework. The three institutional factors include TQM implementation, ISO 9000 registration, and country of origin, and the two contingency factors include company size and scope of operations. The results show that the implementation of all TQM practices is similar across subgroups of companies within each contextual factor. In addition, the effects of TQM on four performance measures, as well as the relationships among these measures, are generally similar across subgroup companies. Thus, for the five contextual factors analyzed, the overall findings do not provide support for the argument that TQM and TQM–performance relationships are context‐dependent. The implications of the study for managers and researchers, as well as study limitations, are also discussed.
Quantification of fluorescence in thick specimens, with an application to cyclin B—GFP expression in starfish oocytes
Authors: Terasaki Mark 
Published: March 2006

Background information. Fluorescence imaging of living cells is widely used in cell biology. It is now being extended to thick specimens such as large cells or tissues where it is important to establish methods for obtaining quantitative fluorescence data due to the increasing importance of computational and systems biology approaches.Results. Fluorescent solutions were used as a calibration standard for determining cellular fluorescence concentrations from z series image sequences. The accuracy of the measurements was evaluated using quantitatively injected cells. Different fluorescence attenuation rates of the cytoplasm and nucleoplasm were documented, and autofluorescence levels were determined. This method was used to characterize the effect of cyclin B overexpression on cell‐cycle timing in starfish oocytes. The time interval between application of maturation hormone and germinal vesicle breakdown decreased with increasing cyclin B—GFP (green fluorescent protein) concentration to a level of 100–300 nM, beyond which there was no effect.Conclusions. Conditions for determining fluorescent probe concentrations in large cells or multicellular tissues were established, which will facilitate the collection of data for quantitative studies. This method was used to characterize the effect of cyclin B—GFP expression levels on cell‐cycle timing in starfish oocytes.
Effects of tumour necrosis factor α (TNFα) on Mytilus haemocytes: role of stress‐activated mitogen‐activated protein kinases (MAPKs)
Authors: Betti Michele , Ciacci Caterina , Lorusso Lucia C. , Canonico Barbara , Falcioni Tania , Gallo Gabriella , Canesi Laura 
Published: March 2006

Background information. Many studies indicate that innate immunity in invertebrates can be modulated by a cytokine network like in vertebrates. In molluscs, the immune response is carried out by circulating haemocytes and soluble haemolymph factors. In the present study, the effects of heterologous TNFα (tumour necrosis factor α) on cell signalling and function in the haemocytes of the bivalve Mytilus galloprovincialis Lam. were investigated.Results and conclusions. Addition of TNFα in the absence of haemolymph serum [in ASW (artificial sea water)] induced cellular stress, as indicated by lysosomal destabilization, and decreased phagocytosis; on the other hand, in the presence of serum, TNFα did not affect lysosomal stability and even stimulated phagocytosis. TNFα induced rapid phosphorylation of the stress‐activated p38 and JNK (c‐Jun N‐terminal kinase) MAPKs (mitogen‐activated protein kinases); both effects were persistent in ASW but transient in serum. Activation of p38 and JNKs in mediating the effects of TNFα was confirmed by the use of specific MAPK inhibitors. Moreover, flow cytometric analysis indicated that TNFα in the presence of serum induced transient phosphatidylserine exposure on the haemocyte surface, evaluated as annexin V binding; in ASW, the cytokine resulted in a stable increase in the percentage of both annexin‐ and propidium iodide‐positive cells, indicating possible apoptotic/necrotic processes. The results indicate that TNFα can affect the function of bivalve haemocytes through conserved transduction pathways involving stress‐activated MAPKs and suggest that the haemocyte response to the cytokine is influenced by soluble haemolymph components.
Exploring complexity when diversity is limited: institutional complementarity in theories of rule of law and national systems revisited
Authors: Kogut Bruce , Ragin Charles 
Published: March 2006

AbstractCategories reflect particular theories about the world in the form of causal and performative claims. Unlike attributes that are the mainstay of statistical analysis, these discrete entities consist of the contradiction of being easy to understand and yet hard to analyze. An important obstacle to the exploration of causal claims about categories (e.g. nations) is the limited diversity of observed cases. We propose the use of methodologies that take greater exploratory account of causal complexity and that respects the importance of case narratives for theexplicitdecisions made to arrive at theoretical claims. One such methodology is qualitative comparative analysis developed by Charles Ragin. This method is applied to data provided by two independent lines of study (i.e. rule of law and governance and varieties of capitalism) to show how the identification, and adoption, ofprototypesis complex. Through the use of logic (e.g. De Morgan's law) and reductive inferences, we explore the space of observed and unobserved configurations, showing how the identification of institutional configurations relies upon logical assumptions that are rarely made explicit. The analysis rejects the hypothesis of rule of law and financial development and qualifies the institutional prototypes of corporatism and market as useful descriptions of the varieties of capitalism.
Relevance in business research: the case of country‐of‐origin research in marketing
Authors: Usunier Jean‐Claude 
Published: March 2006

AbstractA popular research topic in international marketing is how a product's country‐of‐origin influences consumer evaluations (COO research). The purpose of this contribution is to explore how COO research has developed over time in growing disconnection with both consumer and corporate concern. We offer a number of possible explanations to this ‘relevance gap,’ with the caveat that these explanations may be contingent to the COO case study.