University of North Carolina at Charlotte

About: University of North Carolina at Charlotte is a education organization based out in Charlotte, North Carolina, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 8772 authors who have published 22239 publications receiving 562529 citations. The organization is also known as: UNC Charlotte & UNCC.

Effects of acclimation temperature and cadmium exposure on cellular energy budgets in the marine mollusk Crassostrea virginica: linking cellular and mitochondrial responses

Abstract: In order to understand the role of metabolic regulation in environmental stress tolerance, a comprehensive analysis of demand-side effects (i.e. changes in energy demands for basal maintenance) and supply-side effects (i.e. metabolic capacity to provide ATP to cover the energy demand) of environmental stressors is required. We have studied the effects of temperature (12, 20 and 28 degrees C) and exposure to a trace metal, cadmium (50 microg l(-1)), on the cellular energy budget of a model marine poikilotherm, Crassostrea virginica (eastern oysters), using oxygen demand for ATP turnover, protein synthesis, mitochondrial proton leak and non-mitochondrial respiration in isolated gill and hepatopancreas cells as demand-side endpoints and mitochondrial oxidation capacity, abundance and fractional volume as supply-side endpoints. Cadmium exposure and high acclimation temperatures resulted in a strong increase of oxygen demand in gill and hepatopancreas cells of oysters. Cd-induced increases in cellular energy demand were significant at 12 and 20 degrees C but not at 28 degrees C, possibly indicating a metabolic capacity limitation at the highest temperature. Elevated cellular demand in cells from Cd-exposed oysters was associated with a 2-6-fold increase in protein synthesis and, at cold acclimation temperatures, with a 1.5-fold elevated mitochondrial proton leak. Cellular aerobic capacity, as indicated by mitochondrial oxidation capacity, abundance and volume, did not increase in parallel to compensate for the elevated energy demand. Mitochondrial oxidation capacity was reduced in 28 degrees C-acclimated oysters, and mitochondrial abundance decreased in Cd-exposed oysters, with a stronger decrease (by 20-24%) in warm-acclimated oysters compared with cold-acclimated ones (by 8-13%). These data provide a mechanistic basis for synergism between temperature and cadmium stress on metabolism of marine poikilotherms. Exposure to combined temperature and cadmium stress may result in a strong energy deficiency due to the elevated energy demand on one hand and a reduced mitochondrial capacity to cover this demand on the other hand, which may have important implications for surviving seasonally and/or globally elevated temperatures in polluted estuaries.

The role of leader emotion management in leader–member exchange and follower outcomes

Abstract: In response to growing calls for such research, we develop and test a model of leader behaviors directed at managing followers' negative emotions. These leader interpersonal emotion management strategies (IEMS) are posited to affect followers' organizational citizenship behaviors performed within interpersonal relationships (OCBIs) and job satisfaction via follower perceptions of the quality of the leader–member exchange relationship (LMX). In addition, we posit that some, but not all, leader IEMS promote and strengthen LMX relationships. Results from multisource data in a sample of 163 leader–follower dyads confirmed the majority of the hypothesized direct effects of the leader IEMS and mediating effects of LMX.

Risk factors for chronic kidney disease in a large cohort of HIV-1 infected individuals initiating antiretroviral therapy in routine care

Abstract: Objective: To examine long-term effects of antiretroviral therapy (ART) on kidney function, we evaluated the incidence and risk factors for chronic kidney disease (CKD) among ART-naive, HIV-infected adults and compared changes in estimated glomerular filtration rates (eGFR) before and after starting ART. Methods: Multicenter observational cohort study of patients with at least one serum creatinine measurement before and after initiating ART. Cox proportional hazard models, and marginal structure models examined CKD risk factors; mixed-effects linear models examined eGFR slopes. Results: Three thousand, three hundred and twenty-nine patients met entry criteria, contributing 10099 person-years of observation on ART. ART was associated with a significantly slower rate of eGFR decline (from � 2.18 to � 1.37ml/min per 1.73m 2 per year; P ¼0.02). The incidence of CKD defined by eGFR thresholds of 60, 45 and 30ml/ min per 1.73m 2 was 10.5, 3.4 and 1.6 per 1000 person-years, respectively. In adjusted analyses black race, hepatitis C coinfection, lower time-varying CD4 cell count and higher time-varying viral load on ART were associated with higher CKD risk, and the magnitude of these risks increased with more severe CKD. Tenofovir and a ritonavirboosted protease inhibitor (rPI) was also associated with higher CKD risk [hazard odds ratio for an eGFR threshold <60ml/min per 1.73m 2 : 3.35 (95% confidence interval (CI) ¼1.40‐8.02)], which developed in 5.7% of patients after 4 years of exposure to this regimen-type. Conclusion: ART was associated with reduced CKD risk in association with CD4 cell restoration and plasma viral load suppression, despite an increased CKD risk that was associated with initial regimens that included tenofovir and rPI. 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins AIDS 2012, 26:1907‐1915

A rule-based framework for role based delegation

Abstract: In current role-based systems, security officers handle assignments of users to roles However, fully depending on this functionality may increase management efforts in a distributed environment because of the continuous involvement from security officers The emerging technology of role-based delegation provides a means for implementing RBAC in a distributed environment with empowerment of individual users The basic idea behind a role-based delegation is that users themselves may delegate role authorities to other users to carry out some functions on behalf of the former This paper presents a role-based delegation model called RDM2000 (role-based delegation model 2000), which is an extension of RBDM0 by supporting hierarchical roles and multi-step delegation The paper explores different approaches for delegation and revocation Also, a rule-based language for specifying and enforcing the policies based on RDM2000 is introduced