The role of schools in supporting HIV-affected children in sub-Saharan Africa: a systematic review

Aim: To establish an overview of school-based interventions carried out to support the health and well-being of vulnerable children in Zimbabwe and similar socio-economic contexts in sub-Saharan Africa. Methods: A literature search was carried out in Web of Knowledge using combinations of the following search terms: support, intervention, school, child, Zimbabwe, sub-Saharan Africa, health, well-being, inclusion and enrolment. A total of 12 articles were identified as relevant to the research question and included in this review. Findings: Interventions in sub-Saharan Africa have been successful in implementing health knowledge at schools. Whereas a few studies have acknowledged the potential of schools to go beyond knowledge and facilitate a supportive and caring environment for vulnerable children, they tend to refer to studies reporting on externally implemented and resourced interventions. Limited attention has been given to the psychosocial well-being of children and children’s own experiences of school environments. Conclusion: Existing literature needs to be supplemented with research exploring pathways through which schools in challenging socio-economic contexts manage to support HIV-affected children by drawing on already available resources and by involving local communities. Furthermore, more in-depth qualitative research from children’ is needed in order to understand the needs of HIV-affected children and how they themselves experience ways in which schools support them to cope with adversity in their everyday lives

Role for the fission yeast RecQ helicase in DNA repair in G2.

Members of the RecQ helicase subfamily are mutated in several human genomic instability syndromes, such as Bloom, Werner, and Rothmund-Thomson syndromes. We show that Rqh1, the single Schizosaccharomyces pombe homologue, is a 3'-to-5' helicase and exists with Top3 in a high-molecular-weight complex. top3 deletion is inviable, and this is suppressed by concomitant loss of rqh1 helicase activity or loss of recombination functions. This is consistent with RecQ helicases in other systems. By using epistasis analysis of the UV radiation sensitivity and by analyzing the kinetics of Rhp51 (Rad51 homologue), Rqh1, and Top3 focus formation in response to UV in synchronized cells, we identify the first evidence of a function for Rqh1 and Top3 in the repair of UV-induced DNA damage in G(2). Our data provide evidence that Rqh1 functions after Rad51 focus formation during DNA repair. We also identify a function for Rqh1 upstream of recombination in an Rhp18-dependent (Rad18 homologue) pathway. The model that these data allow us to propose helps to reconcile different interpretations of RecQ family helicase function that have arisen between work based on the S. pombe system and models based on studies of Saccharomyces cerevisiae SGS1 suggesting that RecQ helicases act before Rad51

Glacial/interglacial changes in mineral dust and sea-salt records in polar ice cores: sources, transport, and deposition

Sea salt and mineral dust records as represented by Na+ and Ca2+ concentrations, respectively, in Greenland and Antarctic ice cores show pronounced glacial/interglacial variations. For the Last Glacial Maximum (LGM) mineral dust (sea salt) concentrations in Greenland show an increase of a factor of approximately 80 (15) compared to the Holocene and significant shifts by a factor of 15 (5) during Dansgaard Oeschger events. In Antarctica, the dust (sea salt) flux is enhanced by a factor of 15 (3) during the LGM compared to the Holocene and variations by approximately a factor of 8 (1-2) exist in parallel to Antarctic warm events. Primary glacial dust sources are the Asian deserts for Greenland and Patagonia for Antarctica. Ice core evidence and model results show that both changes in source strength as well as atmospheric transport and lifetime contributed to the observed changes in Greenland ice cores. In Antarctica changes in ice core fluxes are in large parts related to source variations both for sea salt and dust, where the formation of sea salt aerosol from sea ice may play a pivotal role. Summarizing our latest estimates on changes in sources, transport and deposition these processes are roughly able to explain the glacial increase in sea salt in both polar regions while they fall short by at least a factor of 4-7 for mineral dust. Future improvements in model resolution and in the formulation of source and transport processes together with new ice core records, e.g. on dust size distributions, will eventually allow to converge models and observations

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