bluuebunny/crossref_metadata_2025 huggingface dataset:
ATP-dependent Potassium Channels: A Converging Target for Endogenous Anticonvulsant Factors
Authors: Mazarati Andrey
Published: July 2005

Zinc Inhibits Glutamate Release via Activation of Presynaptic K Channels and Reduces Ischaemic Damage in Rat Hippocampus

Bancila V, Nikonenko I, Dunant Y, Bloc A

J Neurochem 2004;90:1243–1250

Purpose

Zinc is concentrated in certain CNS excitatory tracts, especially in hippocampal mossy fibers, where it has been suggested to modulate synaptic transmission and plasticity.

Methods

By using rat mossy fiber synaptosomes depolarized by 4-aminopyridine, we show here that low zinc concentrations restore the membrane potential and reduce glutamate release. Both effects arose from activation of ATP-sensitive potassium channels (KATP), because they were mimicked by the KATP-opener diazoxide and antagonized by the KATP-blocker tolbutamide. By using recombinant channels expressed in COS-7 cells, we confirmed that micromolar zinc did activate KATP of the type found in hippocampus. We tested the hypothesis that this action of zinc could be beneficial during an ischemic challenge by using organotypic hippocampal slice cultures.

Results

When zinc was applied at micromolar concentrations during a brief anoxic–hypoglycemic episode, it significantly attenuated the ensuing neuronal death, whereas chelation of endogenous zinc markedly aggravated cell damage. Protective effect of zinc was mediated through KATP, as was shown by using the opener diazoxide and the blocker tolbutamide.

Conclusions

Thus, by activating presynaptic KATP channels, zinc protects neurons from hyperexcitation, excessive transmitter release, and exitotoxicity, and may thus act as an endogenous neuroprotector in conditions such as epilepsy or stroke.
The Role of the Subiculum in Epilepsy and Epileptogenesis
Authors: Stafstrom Carl E.
Published: July 2005

The subiculum is the first output structure distal to the hippocampus, abutting subfield CA1. As such, the subiculum receives afferent input from the hippocampus. Accumulating clinical and experimental evidence suggests that the subiculum plays an important role in the initiation and maintenance of epileptic discharges in temporal lobe epilepsy. This review discusses the anatomy and physiology of the subiculum and examines its participation in epilepsy and epileptogenesis.
Long‐Term Follow‐Up of Cardiac Resynchronization Therapy in Patients with End‐Stage Heart Failure
Authors: MOLHOEK SANDER G. , BAX JEROEN J. , BLEEKER GABE B. , HOLMAN EDUARD R. , VAN ERVEN LIESELOT , BOOTSMA MARIANNE , BOERSMA ERIC , STEENDIJK PAUL , VAN DER WALL ERNST E. , SCHALIJ MARTIN J.
Published: July 2005

Introduction: Cardiac resynchronization therapy (CRT) has been introduced to treat patients with end‐stage heart failure, and results of this technique are promising. The aim of our study was to assess the sustained benefit of CRT in a large patient cohort with end‐stage heart failure at long‐term follow‐up. In addition, the prognosis of responders and nonresponders was evaluated.

Methods and Results: 125 patients with end‐stage heart failure, NYHA class III or IV, LVEF <35%, QRS duration >120 msec and left bundle branch block morphology received a biventricular device. At baseline and 6 months after implantation the following parameters were evaluated: NYHA class, Minnesota Quality of life score, QRS duration on surface ECG, 6‐minute walking distance and LVEF. Follow‐up was obtained up to 3 years. After 6 months, patients were divided in clinical responders and nonresponders according to improvement in NYHA class. All clinical parameters improved significantly at 6‐month follow‐up. Hospitalization for heart failure was 3.8 ± 4.9 days/year before and 0.7 ± 1.6 days/year after CRT. Survival at 1‐, 2‐, and 3‐year follow‐up was 93%, 88%, and 85%, respectively. Responders (78%) showed a significantly better survival than nonresponders at 2‐ and 3‐year follow‐up (96% and 93% for responders versus 81% and 73% for nonresponders, P < 0.05).

Conclusion: The improvement in functional status and symptoms after CRT is maintained at long‐term follow‐up (up to 3 years). The clinical improvement was associated with a significant reduction in hospitalization rate which was also maintained over the years. Preimplantation selection of responders may result in even better long‐term survival.
Anticipation of Radiation Dose to the Conceptus from Occupational Exposure of Pregnant Staff During Fluoroscopically Guided Electrophysiological Procedures
Authors: DAMILAKIS JOHN , PERISINAKIS KOSTAS , THEOCHAROPOULOS NICHOLAS , TZEDAKIS ANTONIOS , MANIOS EMMANOUEL , VARDAS PANAYIOTIS , GOURTSOYIANNIS NICHOLAS
Published: July 2005

Introduction: A female employee working in the electrophysiology suite has the right to know potential radiation hazards to the unborn child before she is pregnant or before she decides to formally declare her pregnancy. Moreover, the employer of a declared pregnant worker must evaluate the work situation and ensure that the conceptus dose is kept below the maximum permissible level during the remaining gestation period. The aim of this study was to develop a method for conceptus dose anticipation and determination of maximum workload allowed for the pregnant employee who participates in fluoroscopically guided electrophysiological procedures.

Methods and Results: A C‐arm fluoroscopy system, an anthropomorphic phantom, and a radiation meter were used to obtain scattered air kerma dose rates separately for each of the three fluoroscopic projections typically used in the electrophysiology suite. Air kerma to conceptus dose conversion factors for all trimesters of gestation were calculated using Monte Carlo simulation. A formula is presented for the anticipation of the conceptus dose from occupational exposure of pregnant staff during fluoroscopically guided electrophysiological procedures. Normalized data are provided for conceptus dose estimation from occupational exposure of pregnant staff working in any electrophysiology laboratory. A methodology for estimation of maximum workload allowed for each month of the remaining gestation period of a worker who declared her pregnancy is proposed, which ensures that the regulatory dose limits are not exceeded.

Conclusion: Data presented may be used for the implementation of a radiation protection program designed for pregnant staff working in an electrophysiological suite.
Bayesian Error‐in‐Variable Survival Model for the Analysis of GeneChip Arrays
Authors: Tadesse Mahlet G. , Ibrahim Joseph G. , Gentleman Robert , Chiaretti Sabina , Ritz Jerome , Foa Robin
Published: July 2005

SummaryDNA microarrays in conjunction with statistical models may help gain a deeper understanding of the molecular basis for specific diseases. An intense area of research is concerned with the identification of genes related to particular phenotypes. The technology, however, is subject to various sources of error that may lead to expression readings that are substantially different from the true transcript levels. Few methods for microarray data analysis have accounted for measurement error in a substantial way and that is the purpose of this investigation. We describe a Bayesian error‐in‐variable model for the analysis of microarray data from a clinical study of patients with acute lymphoblastic leukemia. We focus in particular on the problem of identifying genes whose expression patterns are associated with duration of remission. This is a question of great practical interest since relapse is a major concern in the treatment of this disease. We explore the effects of ignoring the uncertainty in the expression estimates on the selection and ranking of genes.
Estimating the Species Accumulation Curve Using Mixtures
Authors: Xuan Mao Chang , Colwell Robert K. , Chang Jing
Published: July 2005

Summary As a significant tool in ecological studies, the species accumulation curve or the collector's curve is the graph of the expected number of detected species as a function of sampling effort. The problem of estimating the species accumulation curve based on an empirical data set arising from quadrat sampling is studied in a nonparametric binomial mixture model. It will be shown that estimating the species accumulation curve not only is independent of the unknown number of species but also includes estimating the number of species as a limiting case. For the purpose of interpolation, moment‐based estimators, associated with asymptotic confidence intervals, are developed from several points of view. A likelihood‐based procedure is developed for the purpose of extrapolation, associated with bootstrap confidence intervals. The proposed methods are illustrated by ecological data sets.
Imputation and Variable Selection in Linear Regression Models with Missing Covariates
Authors: Yang Xiaowei , Belin Thomas R. , Boscardin W. John
Published: July 2005

SummaryAcross multiply imputed data sets, variable selection methods such as stepwise regression and other criterion‐based strategies that include or exclude particular variables typically result in models with different selected predictors, thus presenting a problem for combining the results from separate complete‐data analyses. Here, drawing on a Bayesian framework, we propose two alternative strategies to address the problem of choosing among linear regression models when there are missing covariates. One approach, which we call “impute, then select” (ITS) involves initially performing multiple imputation and then applying Bayesian variable selection to the multiply imputed data sets. A second strategy is to conduct Bayesian variable selection and missing data imputation simultaneously within one Gibbs sampling process, which we call “simultaneously impute and select” (SIAS). The methods are implemented and evaluated using the Bayesian procedure known as stochastic search variable selection for multivariate normal data sets, but both strategies offer general frameworks within which different Bayesian variable selection algorithms could be used for other types of data sets. A study of mental health services utilization among children in foster care programs is used to illustrate the techniques. Simulation studies show that both ITS and SIAS outperform complete‐case analysis with stepwise variable selection and that SIAS slightly outperforms ITS.
Multievent: An Extension of Multistate Capture–Recapture Models to Uncertain States
Authors: Pradel Roger
Published: July 2005

Summary Capture–recapture models were originally developed to account for encounter probabilities that are less than 1 in free‐ranging animal populations. Nowadays, these models can deal with the movement of animals between different locations and are also used to study transitions between different states. However, their use to estimate transitions between states does not account for uncertainty in state assignment. I present the extension of multievent models, which does incorporate this uncertainty. Multievent models belong to the family of hidden Markov models. I also show in this article that the memory model, in which the next state or location is influenced by the previous state occupied, can be fully treated within the framework of multievent models.
Effects of Variance‐Function Misspecification in Analysis of Longitudinal Data
Authors: Wang You‐Gan , Lin Xu
Published: July 2005

SummaryThe approach of generalized estimating equations (GEE) is based on the framework of generalized linear models but allows for specification of a working matrix for modeling within‐subject correlations. The variance is often assumed to be a known function of the mean. This article investigates the impacts of misspecifying the variance function on estimators of the mean parameters for quantitative responses. Our numerical studies indicate that (1) correct specification of the variance function can improve the estimation efficiency even if the correlation structure is misspecified; (2) misspecification of the variance function impacts much more on estimators for within‐cluster covariates than for cluster‐level covariates; and (3) if the variance function is misspecified, correct choice of the correlation structure may not necessarily improve estimation efficiency. We illustrate impacts of different variance functions using a real data set from cow growth.
Modeling Late Entry Bias in Survival Analysis
Authors: Matsuura Masaaki , Eguchi Shinto
Published: July 2005

SummaryIn a failure time analysis, we sometimes observe additional study subjects who enter during the study period. These late entries are treated as left‐truncated data in the statistical literature. However, with real data, there is a substantial possibility that the delayed entries may have extremely different hazards compared to the other standard subjects. We focus on a situation in which such entry bias might arise in the analysis of survival data. The purpose of the present article is to develop an appropriate methodology for making inference about data including late entries. We construct a model that includes parameters for the effect of delayed entry bias having no specification for the distribution of entry time. We also discuss likelihood inference based on this model and derive the asymptotic behavior of estimates. A simulation study is conducted for a finite sample size in order to compare the analysis results using our method with those using the standard method, where independence between entry time and failure time is assumed. We apply this method to mortality analysis among atomic bomb survivors defined in a geographical study region.
Nonparametric Estimation of the Bivariate Recurrence Time Distribution
Authors: Huang Chiung‐Yu , Wang Mei‐Cheng
Published: July 2005

Summary This article considers statistical models in which two different types of events, such as the diagnosis of a disease and the remission of the disease, occur alternately over time and are observed subject to right censoring. We propose nonparametric estimators for the joint distribution of bivariate recurrence times and the marginal distribution of the first recurrence time. In general, the marginal distribution of the second recurrence time cannot be estimated due to an identifiability problem, but a conditional distribution of the second recurrence time can be estimated nonparametrically. In the literature, statistical methods have been developed to estimate the joint distribution of bivariate recurrence times based on data on the first pair of censored bivariate recurrence times. These methods are inefficient in the model considered here because recurrence times of higher orders are not used. Asymptotic properties of the proposed estimators are established. Numerical studies demonstrate the estimators perform well with practical sample sizes. We apply the proposed method to the South Verona, Italy, psychiatric case register (PCR) data set for illustration of the methods and theory.
A Semiparametric Two‐Component “Compound” Mixture Model and Its Application to Estimating Malaria Attributable Fractions
Authors: Qin Jing , Leung Denis H. Y.
Published: July 2005

SummaryMalaria remains a major epidemiologic problem in many developing countries. Malaria is defined as the presence of parasites and symptoms (usually fever) due to the parasites. In endemic areas, an individual may have symptoms attributable either to malaria or to other causes. From a clinical viewpoint, it is important to correctly diagnose an individual who has developed symptoms so that the appropriate treatments can be given. From an epidemiologic and economic viewpoint, it is important to determine the proportion of malaria‐affected cases in individuals who have symptoms so that policies on intervention program can be developed. Once symptoms have developed in an individual, the diagnosis of malaria can be based on the analysis of the parasite levels in blood samples. However, even a blood test is not conclusive as in endemic areas many healthy individuals can have parasites in their blood slides. Therefore, data from this type of study can be viewed as coming from a mixture distribution, with the components corresponding to malaria and nonmalaria cases. A unique feature in this type of data, however, is the fact that a proportion of the nonmalaria cases have zero parasite levels. Therefore, one of the component distributions is itself a mixture distribution. In this article, we propose a semiparametric likelihood approach for estimating the proportion of clinical malaria using parasite‐level data from a group of individuals with symptoms. Our approach assumes the density ratio for the parasite levels in clinical malaria and nonclinical malaria cases can be modeled using a logistic model. We use empirical likelihood to combine the zero and nonzero data. The maximum semiparametric likelihood estimate is more efficient than existing nonparametric estimates using only the frequencies of zero and nonzero data. On the other hand, it is more robust than a fully parametric maximum likelihood estimate that assumes a parametric model for the nonzero data. Simulation results show that the performance of the proposed method is satisfactory. The proposed method is used to analyze data from a malaria survey carried out in Tanzania.
Adaptive Design and Estimation in Randomized Clinical Trials with Correlated Observations
Authors: Yin Guosheng , Shen Yu
Published: July 2005

SummaryClinical trial designs involving correlated data often arise in biomedical research. The intracluster correlation needs to be taken into account to ensure the validity of sample size and power calculations. In contrast to the fixed‐sample designs, we propose a flexible trial design with adaptive monitoring and inference procedures. The total sample size is not predetermined, but adaptively reestimated using observed data via a systematic mechanism. The final inference is based on a weighted average of the block‐wise test statistics using generalized estimating equations, where the weight for each block depends on cumulated data from the ongoing trial. When there are no significant treatment effects, the devised stopping rule allows for early termination of the trial and acceptance of the null hypothesis. The proposed design updates information regarding both the effect size and within‐cluster correlation based on the cumulated data in order to achieve a desired power. Estimation of the parameter of interest and its confidence interval are proposed. We conduct simulation studies to examine the operating characteristics and illustrate the proposed method with an example.
Adaptive Risk Group Refinement
Authors: LeBlanc Michael , Moon James , Crowley John
Published: July 2005

SummaryWe construct interpretable prognostic rules based on a sequence of “box‐shaped” regions in the predictor space indexed by the fraction of patients in the prognostic group. In addition, the method can be used as a building block to construct more general prognostic rules based on unions of boxes, or even as a tool to find multiple prognostic groups. Simulations are used to study the properties of the new method and compare it to constructing prognostic groups based on regression trees and linear proportional hazards (PH) models. We consider an example based on data from several completed clinical trials for patients with multiple myeloma.
Quantifying Uncertainty Associated with Microbial Count Data: A Bayesian Approach
Authors: Clough H. E. , Clancy D. , O'Neill P. D. , Robinson S. E. , French N. P.
Published: July 2005

Summary We consider the problem of estimating bacterial concentration in a substance, given microbial count data. A Bayesian approach is proposed which naturally allows the incorporation of both plate‐count data and extra information from confirmatory tests such as genotyping by polymerase chain reaction (PCR). The estimation methods yield posterior credible regions for bacterial concentration, in contrast to the previous methods, which generally only produce point estimates. The approach is illustrated with specific reference to the enumeration of the food‐borne pathogen Escherichia coli O157 by spiral plating, although the methodology can be applied to any bacterium or counting method of interest. The results obtained provide guidance to the experimenter as to the number of confirmatory tests which should be performed, and also suggest that in the initial plate count one should err on the side of including rather than excluding colonies whose genotype seems unclear.
A Varying‐Coefficient Cox Model for the Effect of Age at a Marker Event on Age at Menopause
Authors: Nan Bin , Lin Xihong , Lisabeth Lynda D. , Harlow Siobán D.
Published: July 2005

SummaryIt is of recent interest in reproductive health research to investigate the validity of a marker event for the onset of menopausal transition and to estimate age at menopause using age at the marker event. We propose a varying‐coefficient Cox model to investigate the association between age at a marker event, defined as a specific bleeding pattern change, and age at menopause, where both events are subject to censoring and their association varies with age at the marker event. Estimation proceeds using the regression spline method. The proposed method is applied to the Tremin Trust data to evaluate the association between age at onset of the 60‐day menstrual cycle and age at menopause. The performance of the proposed method is evaluated using a simulation study.
Frequentist Performance of Bayesian Confidence Intervals for Comparing Proportions in 2 × 2 Contingency Tables
Authors: Agresti Alan , Min Yongyi
Published: July 2005

SummaryThis article investigates the performance, in a frequentist sense, of Bayesian confidence intervals (CIs) for the difference of proportions, relative risk, and odds ratio in 2 × 2 contingency tables. We consider beta priors, logit‐normal priors, and related correlated priors for the two binomial parameters. The goal was to analyze whether certain settings for prior parameters tend to provide good coverage performance regardless of the true association parameter values. For the relative risk and odds ratio, we recommend tail intervals over highest posterior density (HPD) intervals, for invariance reasons. To protect against potentially very poor coverage probabilities when the effect is large, it is best to use a diffuse prior, and we recommend the Jeffreys prior. Otherwise, with relatively small samples, Bayesian CIs using more informative (even uniform) priors tend to have poorer performance than the frequentist CIs based on inverting score tests, which perform uniformly quite well for these parameters.
A Note on P‐Values under Group Sequential Testing and Nonproportional Hazards
Authors: Gillen Daniel L. , Emerson Scott S.
Published: July 2005

Summary Group sequential designs are often used for periodically assessing treatment efficacy during the course of a clinical trial. Following a group sequential test, P‐values computed under the assumption that the data were gathered according to a fixed sample design are no longer uniformly distributed under the null hypothesis of no treatment effect. Various sample space orderings have been proposed for computing proper P‐values following a group sequential test. Although many of the proposed orderings have been compared in the setting of time‐invariant treatment effects, little attention has been given to their performance when the effect of treatment within an individual varies over time. Our interest here is to compare two of the most commonly used methods for computing proper P‐values following a group sequential test, based upon the analysis time (AT) and Z‐statistic orderings, with respect to resulting power functions when treatment effects on survival are delayed. Power under the AT ordering is shown to be heavily influenced by the presence of a delayed treatment effect, while power functions corresponding to the Z‐statistic ordering remain robust under time‐varying treatment effects.
Flotation and entrainment behavior of minerals in talc‐calcite separation
Authors: Akdemir Ünal , Güler Taki , Yildiztekin Güvengez
Published: July 2005

The main aim of a flotation process is to recover the valuable part of the ore with minimum gangue contamination by different mechanisms, such as entrainment. In this study, the flotation rate and recovery of talc and entrainment of fine calcite particles were investigated using individual minerals and a mixture of talc and calcite. The effects of various frothers were tested. The results indicated that the type of frother had significant effects on the recovery, flotation rate and fine gangue entrainment. The addition of kerosene as a collector enhanced selectivity between talc and calcite without any reduction in talc recovery. This was attributed to increasing the rate constant of talc upon kerosene addition without any increase in the calcite fines recovery.
Thermal analysis of eutectic reactions of white cast irons
Authors: Mazur Alexander , Gasik Michael M. , Mazur Vladislav I.
Published: July 2005

Eutectic reactions of different hypo‐eutectic (3.5% C), hyper‐eutectic (5.0% C) and eutectic (4.3% C) white cast irons have been studied by differential scanning calorimetry in argon atmosphere at 20–1480°C. Specimen microstructures were analyzed and their different structural features were characterized. The onset temperatures of eutectic reactions of specimens with both plate‐like and ledeburitic carbide‐based eutectics have been determined as 1136°C and 1145°C, respectively. It is suggested that the plate‐like eutectics are based on γ‐Fe austenite and other metastable carbide FexC (different of cementite θ‐Fe3C).
Organizational Learning and Productivity State Structure and Foreign
Investment in the Rise of the Chinese Corporation
Authors: Guthrie Doug
Published: July 2005

Over the two and a half decades of economic reform in China, two types
of Chinese firms have consistently outperformed their peers. In the 1980s,
it was the firms at the lower levels of the industrial hierarchy, the
township and village enterprises that were closely monitored by local
governments. In the 1990s and beyond, the top performers have been those
Chinese firms that have formal relationships with foreign investors. While
many studies on the economic reforms in China have focused on the hardening
of budget constraints and the transfer of technology from foreign to Chinese
firms, I focus here on the stability created by relationships with local
government offices and with powerful foreign investors. Where advocates of
shock therapy have argued that a rapid transition to market institutions was
the best path to building a market economy, I argue that the successful
practices of the market are learned gradually over time, and the Chinese
firms that are stabilized by attention from local government offices and
relationships with foreign investors are well-positioned to successfully
navigate China's emerging markets. A quantitative analysis of 81 firms in
industrial Shanghai and three case studies help illuminate the mechanisms
behind these relationships.
The Puzzle of China's Township–Village Enterprises The Paradox of Local Corporatism in a Dual-Track Economic Transition
Authors: Li Peter Ping
Published: July 2005

This paper seeks to reconcile and synthesize the diverse views about the township–village enterprises (TVEs) and local corporatism in the context of ongoing institutional changes in China as a transition economy. Specifically, I attempt to integrate the economic, political, cultural, and social explanations for TVEs, especially the two competing views of market competition and political corruption. I focus on the puzzle of TVE efficiency as well as the paradox of local corporatism as a government–business partnership with both a positive function of public alliance for wealth creation and a negative function of private collusion for wealth transfer. I argue that the key to both the puzzle of TVEs and the paradox of local corporatism lies in China's dual-track reform paradigm (i.e. a market-for-mass track and a state-for-élite track). Lastly, I discuss the critical implications for theory building and policymaking regarding economic transition in general.
‘Ren Qing” versus the ‘Big Five’ The Role of Culturally Sensitive
Measures of Individual Difference in Distributive Negotiations
Authors: Liu Leigh Anne , Friedman Raymond A. , Chi Shu-cheng
Published: July 2005

In this study, we examine culture-specific relationships between
individual differences and distributive negotiations. We measured individual
characteristics and their effects on distributive negotiations in both
American and Chinese cultures, using a Western-based scale (the ‘Big Five’)
and a Chinese-based scale (CPAI). We found that agreeableness and
extraversion (from the ‘Big Five’) affected negotiations for Americans, but
not for Chinese. We found that harmony, face and Ren
Qing (from the Chinese-based scales) affected negotiations
for Chinese, but not for Americans. Specifically, we found that in the
American culture, those higher in extraversion and agreeableness achieved
lower economic gain, whereas in the Chinese context that those high in
harmony, face, and Ren Qing were more likely to
be influenced by opening offers and achieve lower economic gain in
distributive negotiations. Our study highlights the need to examine
negotiations using culturally sensitive constructs and measures.
The Psychological Capital of Chinese Workers: Exploring the Relationship with Performance
Authors: Luthans Fred , Avolio Bruce J. , Walumbwa Fred O. , Li Weixing
Published: July 2005

Everyone knows about China's huge population and the fast-growing economy. Although macro-level sociological and economic analyses have given some attention to the linkage between the two, at the micro level, the relationship between human resources and, more specifically, psychological capital of Chinese workers and their performance has been largely ignored. Within the context of three factories (two private and one state-owned) in the People's Republic of China, this exploratory study examined the relationship of a sample (n= 422) of Chinese workers’ positive psychological capital states and their performance. Results indicated the workers’ positive states of hope, optimism, and resiliency, separately and when the three were combined into a core construct of psychological capital, significantly correlated with their performance, as rated by their supervisors. An analysis of workers in one of the factories (n= 272) also found a significant relationship between the workers’ positive psychological capital and the performance outcome of relative merit-based salary. Limitations, future research, and practical implications conclude the article.
Group Citizenship Behaviour Conceptualization and Preliminary Tests of its Antecedents and Consequences
Authors: Chen Xiao-Ping , Lam Simon S. K. , Naumann Stefanie E. , Schaubroeck John
Published: July 2005

Group citizenship behaviour (GCB) is conceptualized as a distinct group-level phenomenon concerning the extent to which work groups engage in behaviours that support other work groups and the organization as a whole. These behaviours are different from task performance; they enhance and maintain the social and psychological environment in which task performance occurs. Based on the referent-shift consensus model (Chan, 1998), we developed a GCB scale and examined its nomological network. In a sample of 148 work groups in the Hong Kong office of a multinational bank (a total of 743 employees), between-group differences in GCB were greater than within-group differences. GCB was positively associated with procedural justice climate and work group leadership support. Work group cohesiveness and group-organizational goal congruence interactively predicted GCB, as did the negative affective tone of the group and the group's negative affectivity homogeneity. In addition, GCB was positively related to group performance, and negatively related to employee turnover intentions. The theoretical and empirical implications of this study are discussed in the context of Chinese organizations.
Selling China Looking Back and Looking Forward
Authors: Beamish Paul W. , Delios Andrew
Published: July 2005

One of the objectives of Yasheng Huang's book Selling
China: Foreign Direct Investment in the Reform Era is ‘to
gain a better understanding of the operations of the Chinese economy in the
1990s as well as its FDI patterns’ (p. 69). We have no disagreement with
Huang's general argument that for much of the 1990s domestic Chinese firms
were less competitive than they would have been if the Chinese government
had not favoured state-owned enterprises (SOEs).

Similarly, while acknowledging the positive impact of FDI on China's
development, Huang has real concern with FDI's disproportionately large role
in the economy. He further feels that ‘some of China's FDI patterns may
reflect institutional inefficiencies and weaknesses’ (p. 67). Again, we have
no real disagreement that this was the case in the 1990s.
Services and Intimate Partner Violence in the United States: A County‐Level Analysis
Authors: Tiefenthaler Jill , Farmer Amy , Sambira Amandine
Published: July 2005

Despite the prevalence of intimate partner violence and its social costs, we show that many counties lack services to help victims and that community resources play a significant role in determining the likelihood of service provision. Because resources are often generated at the local level and state and federal funding usually require a grant proposal, services for victims of intimate partner violence are more likely to be available in well‐resourced areas with a major college or university in the county. Analysis of the changes in the provision of services since the Violence Against Women Act was introduced suggests that funding needs to be specifically targeted to underserved areas.
The Reporting of Domestic Violence and Sexual Assault by Nonstrangers to the Police
Authors: Felson Richard B. , Paré Paul‐Philippe
Published: July 2005

We examine the effects of the gender of the victim and offender and their relationship to each other on whether sexual and physical assaults are reported to the police. We also examine the reasons victims give for not reporting assaults and whether reporting patterns have changed over time. The analyses are based on a sample of 6,291 physical assaults and 1,787 sexual assaults from the National Violence Against Women Survey. The results suggest that victims are just as likely to report domestic assaults as they are to report assaults by other people they know. Male victims are particularly reluctant to report assaults by their intimate partners, whereas third parties are particularly unlikely to report assaults by partners of either gender. Sexual assaults, particularly those that involve acquaintances, are less likely to be reported. These patterns have not changed since the 1960s.
In‐Hospital Paternity Establishment and Father Involvement in Fragile Families
Authors: Mincy Ronald , Garfinkel Irwin , Nepomnyaschy Lenna
Published: July 2005

This article assesses the effectiveness of in‐hospital paternity establishment, a federal requirement since 1993. We avoid biases in previous studies by using a national sample of nonmarital births (N= 3,254), by including detailed controls for characteristics of unwed mothers and previously unavailable controls for characteristics of fathers, and by estimating reduced form models of the effects of strong paternity establishment regimes. We find that paternity establishment rates are now quite high—69%—and that 6 of 7 paternities are established in the hospital. Even after controlling for previously unavailable characteristics, establishing paternity (in and outside the hospital) is significantly and positively associated with formal and informal child support payments and father‐child visitation. These results hold up in the reduced form models.
Parental Involvement Promotes Rural African American Youths’ Self‐Pride and Sexual Self‐Concepts
Authors: McBride Murry Velma , Brody Gene H. , McNair Lily D. , Luo Zupei , Gibbons Frederick X. , Gerrard Meg , Wills Thomas Ashby
Published: July 2005

This study, an evaluation of the Strong African American Families Program, was designed to determine whether intervention‐induced changes in targeted parenting behaviors were associated with young adolescents’ development of racial pride, self‐esteem, and sexual identity. Participants were 332 African American mothers and their 11‐year‐old children in 9 rural Georgia counties. Families were randomly assigned to a control group or an intervention group. Unlike those in the control families, mothers in the intervention group reported increases in targeted parenting behaviors, which promoted self‐esteem, positive racial identity, and positive sexual self‐concepts among their children. These findings expand the study of African American youths’ identity development by including broader domains of identity and parenting processes other than racial socialization.
The Role of Value Priorities in Paternal and Maternal Involvement in Child Care
Authors: Gaunt Ruth
Published: July 2005

This study used the theory of human values to explore parents' involvement with their children. The relationships between maternal and paternal value priorities and various forms of involvement in child care were examined in a sample of 209 couples with 1 child between 6 and 36 months of age. As predicted, giving high priority to openness‐to‐change values (e.g., self‐direction, stimulation) and low priority to conservation values (e.g., tradition, conformity, security) is associated with more father involvement and less mother involvement. Moreover, and as predicted, the priority given by a spouse to achievement values is negatively related to this spouse's involvement in child care and positively related to the other spouse's involvement. Parents' sociodemographic characteristics partly mediate the associations between value priorities and involvement. The findings also indicate the importance of distinguishing different forms of involvement in child care.
Social Integration, Work‐Family Conflict and Facilitation, and Job and Marital Quality
Authors: Voydanoff Patricia
Published: July 2005

This paper examines relationships between 2 dimensions of social integration (community participation and affective community resources) and job and marital quality. Data from the 1995 National Survey of Midlife Development in the United States (n= 1,816) indicate that the level of community participation is unrelated or negatively related to job and marital quality, whereas affective community resources show positive associations with job and marital quality. Relationships between community participation and affective community resources and job stress are partially mediated by work‐to‐family conflict and facilitation. Family‐to‐work conflict and facilitation partially mediate relationships between affective community resources and marital satisfaction and risk. The study takes a beginning step in establishing relationships and exploring processes that make up the work‐community‐family interface.
Race/Ethnic Differences in the Marital Expectations of Adolescents: The Role of Romantic Relationships
Authors: Crissey Sarah R.
Published: July 2005

I use a sample of 12,973 adolescents in the National Longitudinal Study of Adolescent Health (Add Health) to examine race/ethnic differences in perception of the likelihood of marriage in adulthood and the role of heterosexual romantic relationship experience in explaining this difference. Compared to adolescents from other race/ethnic backgrounds, White adolescents are more likely to date and are especially more likely than Black adolescents to participate in serious romantic relationships that increase marital expectations. Although the type of current or recent relationship is associated with marital expectations, they do not explain the observed race/ethnic gap in these expectations. Overall, the results suggest that these adolescent romantic experiences likely play only a small role in determining differential marital expectations.
Young Fatherhood and Subsequent Disadvantage in the United Kingdom
Authors: Sigle‐Rushton Wendy
Published: July 2005

Although there has been increasing attention to the importance of fathers and their relationships with their children, few studies have examined young parenthood and its consequences for fathers’ life chances. In recent years, this has begun to change, and research is examining, to a far greater extent, the experiences of young fathers. Using data from a cohort of British men born in 1970, this paper uses a propensity score–matching technique to compare the well‐being of 344 men who reported becoming fathers before the age of 22 with men from similar backgrounds who did not. The findings suggest that selection into young fatherhood is substantial but, for some outcomes, significant differences remain.
Community Context, Social Integration Into Family, and Youth Violence
Authors: Knoester Chris , Haynie Dana L
Published: July 2005

The purpose of this study is to analyze the extent to which neighborhood‐level family structure and feelings of family integration are associated with acts of violence among 16,910 adolescents from the National Longitudinal Study of Adolescent Health. The results from our hierarchical linear models indicate that adolescents who live in neighborhoods with lower proportions of single‐parent families and who report higher levels of family integration commit less violence. We also find that neighborhood‐level family structure shapes the extent to which social integration into family matters: In neighborhoods that are considered higher risk environments (i.e., contain greater proportions of single‐parent families), family integration is often less effective in deterring youth violence than it is in lower risk environments.
EVALUATION OF ATTACHMENT AND PENETRATION ABILITIES OF CAMPYLOBACTER JEJUNI ISOLATES OBTAINED FROM HUMANS AND CHICKEN CARCASSES DURING PROCESSING AND AT RETAIL
Authors: GILBERT C.D. , SLAVIK M.F.
Published: July 2005

The differences in attachment and penetration ability of Campylobacter jejuni were determined by analyzing C. jejuni isolates obtained from chicken carcasses and from humans exhibiting symptoms of campylobacteriosis. INT 407 cells, a human cell line originating from the jejunal/ileal region, were used as the in vitro model, and attachment and penetration abilities were evaluated for each isolate. There were no significant differences between the attachment and penetration abilities of chicken isolates and human isolates (HUMN). In addition, a wide range of attachment and penetration abilities was found for the isolates, with many of the HUMN possessing low attachment and penetration abilities. These data indicate that C. jejuni attachment and penetration into the human ileal and jejunal regions may not be primary virulence factors and may only be important in causing more acute symptoms.
BEHAVIOR OF LISTERIA MONOCYTOGENES AND ESCHERICHIA COLI O157:H7 IN FRESH‐SLICED CACTUS‐PEAR FRUIT
Authors: CORBO M. R. , CAMPANIELLO D. , D’AMATO D. , BEVILACQUA A. , SINIGAGLIA M.
Published: July 2005

Storage experiments were conducted to follow the behavior of Listeria monocytogenes and Escherichia coli O157:H7, deliberately inoculated on fresh‐cut cactus‐pear fruits before packaging under modified and control atmosphere and stored at four different temperatures (4, 8, 12 and 20C). L. monocytogenes was able to proliferate during storage at different temperature both in control and modified atmosphere. By comparing the sanitary‐risk values with those of shelf life, it is possible to conclude that the storage of cactus‐pear samples at temperatures greater than 4C, both in control and in modified atmospheres, could lead to a significant health‐time risk, and that this is strictly affected by temperature. E. coli O157:H7 was able to proliferate only in the sample stored at 4 and 8C in both package atmospheres. On the contrary, this species was completely suppressed at the higher temperatures. In our study, E. coli O157:H7 appeared to be much less suited for survival on the surface of the fruit than L. monocytogenes.
OCCURRENCE OF HEMOLYSIN‐PRODUCING AEROMONADS IN MEAT AND OFFAL SOLD IN PORT HARCOURT, NIGERIA
Authors: AMADI E.N. , OBUMWENRE B. , AKANI N.P.
Published: July 2005

Fresh, different meat types and offal were examined for the occurrence of Aeromonas species by the direct‐plating and enrichment methods. The enrichment method (coefficient of variation = 15.1%) enhanced the recovery of Aeromonas species. The major Aeromonas species identified were A. sobria (67.3%) and A. hydrophila (21.2%). Other species occurred in minor proportions and were A. caviae, A. proteolytica and A. salmonicida. Out of the 52 isolates, 50 were motile species except two which were not motile and identified as the species A. proteolytica. Sixteen motile species occurred in cow, 18 in goat and 16 in lamb. The motile species and the two nonmotile species were hemolytic. They were all sensitive to chloramphenicol (30 mg) and resistant to ampicillin (10 mg). The nonmotile A. proteolytica were all resistant to tetracycline. Aeromonas caviae, A. salmonicida, A. hydrophila and A. sobria were killed after exposure to 50C (decimal reduction time, D10 = 30 s). Aeromonads are unlikely to pose a public health problem in Nigeria where meat undergoes prolonged cooking. Meat is a possible factor in the epidemiology of Aeromonas‐associated gastroenteritis in man.
DETERMINATION OF POSSIBLE GENOMIC CHANGES ASSOCIATED WITH DIMORPHISM IN CAMPYLOBACTER JEJUNI
Authors: WANG H. , GILBERT C. , SLAVIK M.F.
Published: July 2005

Campylobacter jejuni is a leading cause of human gastroenteritis. Using a tissue culture system, researchers have found that spiral forms of C. jejuni are more pathogenic than coccoid forms of the same strain. The objective of this research was to investigate genomic changes associated with the dimorphism in C. jejuni using pulsed‐field gel electrophoresis (PFGE) and sequencing of flaA gene of C. jejuni isolated from chicken carcasses and human stool samples. C. jejuni isolates were cultured for 18 h (spiral form) and 72 h (coccoid form). PFGE profiles of both forms of C. jejuni showed 100% genetic similarity. For sequence analysis of the flaA gene of C. jejuni, its short‐variable region (SVR) was analyzed. For the two forms of the same isolate, the nucleic‐acid sequences of the SVR of flaA showed 95–100% similarity. It is concluded that morphological dimorphism of C. jejuni was not associated with genetic changes as measured by the mentioned tests.
EFFECTS OF VITAMIN E SUPPLEMENTATION ON MYOFIBRILLAR PROTEINS OF FAT‐TAILED AWASSI MALE LAMBS
Authors: AKSU M.İ. , AKTAŞ N. , KAYA M. , MACİT M.
Published: July 2005

In this study, the effect of Vitamin E supplementation (for 75 days, 45 mg/day Vit E [DL‐α tocopheryl acetate]) on myofibrillar proteins in the M. Longissimus dorsi of Awassi male lambs was investigated. The lambs were divided into two groups consisting of a control (CG, n = 12) and an experimental (VG, n = 12) treatment starting at the beginning of the fattening period. Both the control group and the Vitamin E group were fed with a concentrate and grass hay close to ad libitum by biweekly adjustment of the amount offered. In addition, the Vitamin E group received the same concentrate plus a supplement of 45 mg of Vitamin E (DL‐α tocopheryl acetate) per lamb per day for 75 days. The effects of Vitamin E on myofibrillar proteins in the M. Longissimus dorsi were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE). The SDS‐PAGE gels indicated that Vitamin E supplementation to diet had a significant effect on actin, myosin and tropomyosin. The density of these bands increased in samples from the Vitamin E‐supplemented group. Also, the pH values of the M. Longissimus dorsi muscles were determined in the present study, and differences between the control and the Vitamin E‐supplemented groups were found insignificant.