Characterisation of the Nematode Community of a Low-Activity Cold Seep in the Recently Ice-Shelf Free Larsen B Area, Eastern Antarctic Peninsula

Background: Recent climate-induced ice-shelf disintegration in the Larsen A (1995) and B (2002) areas along the Eastern Antarctic Peninsula formed a unique opportunity to assess sub-ice-shelf benthic community structure and led to the discovery of unexplored habitats, including a low-activity methane seep beneath the former Larsen B ice shelf. Since both limited particle sedimentation under previously permanent ice coverage and reduced cold-seep activity are likely toinfluence benthic meiofauna communities, we characterised the nematode assemblage of this low-activity cold seep and compared it with other, now seasonally ice-free, Larsen A and B stations and other Antarctic shelf areas (Weddell Sea and Drake Passage), as well as cold-seep ecosystems world-wide.Principal Findings: The nematode community at the Larsen B seep site differed significantly from other Antarctic sites in terms of dominant genera, diversity and abundance. Densities in the seep samples were high (.2000 individuals per 10 cm2) and showed below-surface maxima at a sediment depth of 2–3 cm in three out of four replicates. All samples were dominated by one species of the family Monhysteridae, which was identified as a Halomonhystera species that comprised between 80 and 86% of the total community. The combination of high densities, deeper density maxima and dominance of one species is shared by many cold-seep ecosystems world-wide and suggested a possible dependence upon a chemosynthetic food source. Yet stable 13C isotopic signals (ranging between 221.9760.86% and 224.8561.89%) were indicative of a phytoplankton-derived food source.Conclusion: The recent ice-shelf collapse and enhanced food input from surface phytoplankton blooms were responsible for the shift from oligotrophic pre-collapse conditions to a phytodetritus-based community with high densities and low diversity. The parthenogenetic reproduction of the highly dominant Halomonhystera species is rather unusual for marine nematodes and may be responsible for the successful colonisation by this single species

Silencing women's sexuality: Global AIDS policies and the case of the female condom

Contains fulltext : 116670pub.pdf (publisher's version ) (Open Access)Introduction: The female condom is the only evidence-based AIDS prevention technology that has been designed for the female body; yet, most women do not have access to it. This is remarkable since women constitute the majority of all HIV-positive people living in sub-Saharan Africa, and gender inequality is seen as a driving force of the AIDS epidemic. In this study, we analyze how major actors in the AIDS prevention field frame the AIDS problem, in particular the female condom in comparison to other prevention technologies, in their discourse and policy formulations. Our aim is to gain insight into the discursive power mechanisms that underlie the thinking about AIDS prevention and women's sexual agency. Methods: We analyze the AIDS policies of 16 agencies that constitute the most influential actors in the global response to AIDS. Our study unravels the discursive power of these global AIDS policy actors, when promoting and making choices between AIDS prevention technologies. We conducted both a quantitative and qualitative analysis of how the global AIDS epidemic is being addressed by them, in framing the AIDS problem, labelling of different categories of people for targeting AIDS prevention programmes and in gender marking of AIDS prevention technologies. Results: We found that global AIDS policy actors frame the AIDS problem predominantly in the context of gender and reproductive health, rather than that of sexuality and sexual rights. Men's sexual agency is treated differently from women's sexual agency. An example of such differentiation and of gender marking is shown by contrasting the framing and labelling of male circumcision as an intervention aimed at the prevention of HIV with that of the female condom. Conclusions: The gender-stereotyped global AIDS policy discourse negates women's agency in sexuality and their sexual rights. This could be an important factor in limiting the scale-up of female condom programmes and hampering universal access to female condoms.12 p

25 years on and no end in sight: a perspective on the role of RecG protein.

The RecG protein of Escherichia coli is a double-stranded DNA translocase that unwinds a variety of branched substrates in vitro. Although initially associated with homologous recombination and DNA repair, studies of cells lacking RecG over the past 25 years have led to the suggestion that the protein might be multi-functional and associated with a number of additional cellular processes, including initiation of origin-independent DNA replication, the rescue of stalled or damaged replication forks, replication restart, stationary phase or stress-induced 'adaptive' mutations and most recently, naïve adaptation in CRISPR-Cas immunity. Here we discuss the possibility that many of the phenotypes of recG mutant cells that have led to this conclusion may stem from a single defect, namely the failure to prevent re-replication of the chromosome. We also present data indicating that this failure does indeed contribute substantially to the much-reduced recovery of recombinants in conjugational crosses with strains lacking both RecG and the RuvABC Holliday junction resolvase.CJR is supported by a grant from the Biotechnology and Biological Sciences Research Council [BB/K015729/1]