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.

Human colon mucosal biofilms from healthy or colon cancer hosts are carcinogenic

Abstract: Mucus-invasive bacterial biofilms are identified on the colon mucosa of approximately 50% of colorectal cancer (CRC) patients and approximately 13% of healthy subjects. Here, we test the hypothesis that human colon biofilms comprise microbial communities that are carcinogenic in CRC mouse models. Homogenates of human biofilm-positive colon mucosa were prepared from tumor patients (tumor and paired normal tissues from surgical resections) or biofilm-positive biopsies from healthy individuals undergoing screening colonoscopy; homogenates of biofilm-negative colon biopsies from healthy individuals undergoing screening colonoscopy served as controls. After 12 weeks, biofilm-positive, but not biofilm-negative, human colon mucosal homogenates induced colon tumor formation in 3 mouse colon tumor models (germ-free ApcMinΔ850/+;Il10-/- or ApcMinΔ850/+ and specific pathogen-free ApcMinΔ716/+ mice). Remarkably, biofilm-positive communities from healthy colonoscopy biopsies induced colon inflammation and tumors similarly to biofilm-positive tumor tissues. By 1 week, biofilm-positive human tumor homogenates, but not healthy biopsies, displayed consistent bacterial mucus invasion and biofilm formation in mouse colons. 16S rRNA gene sequencing and RNA-Seq analyses identified compositional and functional microbiota differences between mice colonized with biofilm-positive and biofilm-negative communities. These results suggest human colon mucosal biofilms, whether from tumor hosts or healthy individuals undergoing screening colonoscopy, are carcinogenic in murine models of CRC.

Optimal Reinsurance Arrangements Under Tail Risk Measures

Abstract: Regulatory authorities demand insurance companies control their risk exposure by imposing stringent risk management policies. This article investigates the optimal risk management strategy of an insurance company subject to regulatory constraints. We provide optimal reinsurance contracts under different tail risk measures and analyze the impact of regulators' requirements on risk sharing in the reinsurance market. Our results underpin adverse incentives for the insurer when compulsory Value-at-Risk risk management requirements are imposed. But economic effects may vary when regulatory constraints involve other risk measures. Finally, we compare the obtained optimal designs to existing reinsurance contracts and alternative risk transfer mechanisms on the capital market.

Five Approaches to Social Sustainability and an Integrated Way Forward

Abstract: Sustainability is often conceived of as an attempt to balance competing economic, environmental and social priorities. Over the course of three decades of scholarship, however, the meaning and appropriate application of the ‘social pillar’ continues to inspire confusion. In this paper, we posit that the inherent challenge of understanding social sustainability is its many legitimate meanings plus a lack of interdisciplinary scholarship. We draw from literature in multiple disciplines to illustrate five different ways that the concept of social sustainability has been applied in scholarship and professional practice, and highlighting the importance of applications that acknowledge placed-based, process-oriented perspectives that understand social, economic, and environmental imperatives as integrated concepts. Ironically, this framing forecloses on social sustainability as an entity distinct from environmental and economic sustainability. We believe that organizing the conversation around these five applications can help advocates of sustainability use the concept of social sustainability in clear and powerful ways while avoiding applications that relegate the social dimensions of sustainability to an afterthought.

Interactive effects of elevated temperature and CO2 levels on energy metabolism and biomineralization of marine bivalves Crassostrea virginica and Mercenaria mercenaria.

Abstract: The continuing increase of carbon dioxide (CO2) levels in the atmosphere leads to increases in global temperatures and partial pressure of CO2 (PCO2) in surface waters, causing ocean acidification. These changes are especially pronounced in shallow coastal and estuarine waters and are expected to significantly affect marine calcifiers including bivalves that are ecosystem engineers in estuarine and coastal communities. To elucidate potential effects of higher temperatures and PCO2 on physiology and biomineralization of marine bivalves, we exposed two bivalve species, the eastern oysters Crassostrea virginica and the hard clams Mercenaria mercenaria to different combinations of PCO2 (~ 400 and 800 μatm) and temperatures (22 and 27 °C) for 15 weeks. Survival, bioenergetic traits (tissue levels of lipids, glycogen, glucose and high energy phosphates) and biomineralization parameters (mechanical properties of the shells and activity of carbonic anhydrase, CA) were determined in clams and oysters under different temperature and PCO2 regimes. Our analysis showed major inter-species differences in shell mechanical traits and bioenergetics parameters. Elevated temperature led to the depletion of tissue energy reserves indicating energy deficiency in both species and resulted in higher mortality in oysters. Interestingly, while elevated PCO2 had a small effect on the physiology and metabolism of both species, it improved survival in oysters. At the same time, a combination of high temperature and elevated PCO2 lead to a significant decrease in shell hardness in both species, suggesting major changes in their biomineralization processes. Overall, these studies show that global climate change and ocean acidification might have complex interactive effects on physiology, metabolism and biomineralization in coastal and estuarine marine bivalves.