Variations in thermal performance of cardiac function of pure and hybrid Mytilus spp. as a factor influencing hybrid zone dynamics

Interspecific hybridisation within the Mytilus complex has been well documented. Distribution patterns of Mytilus congeners in mosaic hybrid zones are hypothesised to reflect differences in their thermal tolerances. In this present study, the relative thermal performance of adult Mytilus galloprovincialis, Mytilus edulis and their hybrids, from a sympatric population within the Southwest England mosaic hybrid zone was assessed using cardiac function as a proxy for thermal performance. As indices of cardiac performance, the Arrhenius break temperature (ABT), the maximum heart rate, the slope post-ABT and the flat line temperature were used. Examination of the response of cardiac activity under emersion conditions, revealed that parental genotypes had a greater thermal limit of cardiac performance (indexed by ABT); with the ability to sustain cardiac function at temperatures, approximately 6 oC higher than for hybrids. However, the upper thermal limits of M. galloprovincialis and M. edulis did not differ between the two taxa. In contrast to previous studies which have described adult Mytilus hybrids as intermediate for several physiological traits, this study shows hybrid genotypes have reduced fitness compared to both parental taxa, using cardiac performance as a proxy. These findings suggest evidence of hybrid depression as a result of increased susceptibility to thermal stress, which could influence hybrid zone dynamics via selection against hybrids. Thus, the increased susceptibility to elevated temperatures in hybrids may serve as a postzygotic barrier within the Mytilus complex. In light of future environmental change, this could have potential implications on the distribution and structure of pure species and hybrid populations

Persistent risk for new, subsequent new and recurrent hepatocellular carcinoma despite successful anti-hepatitis B virus therapy and tumor ablation: The need for hepatitis B virus cure.

Hepatitis B virus (HBV) is one of the most significant hepatocarcinogens. The ultimate goal of anti-HBV treatment is to prevent the development of hepatocellular carcinoma (HCC). During the last two decades, with the use of currently available anti-HBV therapies (lamivudine, entecavir and tenofovir disoproxil fumatate), there has been a decrease in the incidence of HBV-associated HCC (HBV-HCC). Furthermore, several studies have demonstrated a reduction in recurrent or new HCC development after initial HCC tumor ablation. However, during an observation period spanning 10 to 20 years, several case reports have demonstrated the development of new, subsequent new and recurrent HCC even in patients with undetectable serum HBV DNA. The persistent risk for HCC is attributed to the presence of covalently closed circular DNA (cccDNA) in the hepatocyte nucleus which continues to work as a template for HBV replication. While a functional cure (loss of hepatitis B surface antigen and undetectable viral DNA) can be attained with nucleos(t)ide analogues, these therapies do not eliminate cccDNA. Of utmost importance is successful eradication of the transcriptionally active HBV cccDNA from hepatocyte nuclei which would be considered a complete cure. The unpredictable nature of HCC development in patients with chronic HBV infection shows the need for a complete cure. Continued support and encouragement for research efforts aimed at developing curative therapies is imperative. The aims of this minireview are to highlight these observations and emphasize the need for a cure for HBV

Online Information Privacy: Measuring the Cost-Benefit Trade-Off

Concern over information privacy is widespread and rising. However, prior research is silent about the value of information privacy and the benefit of privacy protection. We conducted a conjoint analysis to explore individualsí trade-offs between the benefits and costs of providing personal information to Websites. We find that economic incentives (monetary reward and future convenience) do affect individualsí preferences over Websites with differing privacy policies. For instance, the disallowance of secondary use of personal information is worth between $39.83 and$49.78. Surprisingly, we find that cost-benefit trade-offs did not vary with personal characteristics including gender, contextual knowledge, individualism, and trust propensity

Biowaste and vegetable waste compost application to agriculture

The landfilling of biodegradable waste is proven to contribute to environmental degradation. Compost use in agriculture is increasing as both an alternative to landfilling for the management of biodegradable waste, as well as means of increasing or preserving soil organic matter. This research aimed to contribute to the identification of a system for managing the utilization of vegetable waste (agricultural plant-tissue waste) and biowaste (source-separated biodegradable municipal solid waste) composts for sustainable agriculture, with particular regards to nitrogen availability and leaching.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Exosomes containing HIV protein Nef reorganize lipid rafts potentiating inflammatory response in bystander cells.

HIV infection has a profound effect on "bystander" cells causing metabolic co-morbidities. This may be mediated by exosomes secreted by HIV-infected cells and containing viral factors. Here we show that exosomes containing HIV-1 protein Nef (exNef) are rapidly taken up by macrophages releasing Nef into the cell interior. This caused down-regulation of ABCA1, reduction of cholesterol efflux and sharp elevation of the abundance of lipid rafts through reduced activation of small GTPase Cdc42 and decreased actin polymerization. Changes in rafts led to re-localization of TLR4 and TREM-1 to rafts, phosphorylation of ERK1/2, activation of NLRP3 inflammasome, and increased secretion of pro-inflammatory cytokines. The effects of exNef on lipid rafts and on inflammation were reversed by overexpression of a constitutively active mutant of Cdc42. Similar effects were observed in macrophages treated with exosomes produced by HIV-infected cells or isolated from plasma of HIV-infected subjects, but not with exosomes from cells and subjects infected with ΔNef-HIV or uninfected subjects. Mice injected with exNef exhibited monocytosis, reduced ABCA1 in macrophages, increased raft abundance in monocytes and augmented inflammation. Thus, Nef-containing exosomes potentiated pro-inflammatory response by inducing changes in cholesterol metabolism and reorganizing lipid rafts. These mechanisms may contribute to HIV-associated metabolic co-morbidities