Regulation of DCC Localization by HTZ-1/H2A.Z and DPY-30 Does not Correlate with H3K4 Methylation Levels

Dosage compensation is a specialized form of gene regulation that balances sex-chromosome linked gene expression between the sexes. In C. elegans, dosage compensation is achieved by the activity of the dosage compensation complex (DCC). The DCC binds along both X chromosomes in hermaphrodites to down-regulate gene expression by half, limiting X-linked gene products to levels produced in XO males. Sequence motifs enriched on the X chromosome play an important role in targeting the DCC to the X. However, these motifs are not strictly X-specific and therefore other factors, such as the chromatin environment of the X chromosome, are likely to aid in DCC targeting. Previously, we found that loss of HTZ-1 results in partial disruption of dosage compensation localization to the X chromosomes. We wanted to know whether other chromatin components coordinated with HTZ-1 to regulate DCC localization. One candidate is DPY-30, a protein known to play a role in DCC localization. DPY-30 homologs in yeast, flies, and mammals are highly conserved members of histone H3 lysine 4 (H3K4) methyltransferase Set1/MLL complexes. Therefore, we investigated the hypothesis that the dosage compensation function of DPY-30 involves H3K4 methylation. We found that in dpy-30 animals the DCC fails to stably bind chromatin. Interestingly, of all the C. elegans homologs of Set1/MLL complex subunits, only DPY-30 is required for stable DCC binding to chromatin. Additionally, loss of H3K4 methylation does not enhance DCC mislocalization in htz-1 animals. We conclude that DPY-30 and HTZ-1 have unique functions in DCC localization, both of which are largely independent of H3K4 methylation

Possible futures for groundwater in Burkina Faso under a changing climate

This narrative describes three possible future scenarios for water resources in Burkina Faso and the human and socio-economic impacts that might be experienced by people living in rural areas. The narratives aim to stimulate discussion towards realistic policy responses and the decision support tools needed to assist future planning needs. It is important to recognise that the scenarios do not represent every possible outcome projected by hydroclimate models, and resulting impacts will be contextualised by local circumstances. See here for information about BRAVE (www.walker.ac.uk) and the UPGro programme: upgro.org/consortium/brave2/

African Health OER Network Impact Research Plan

The goal of the evaluation research is to demonstrate the value and impact of the Network to funders, existing and potential institutional partners, OER creators and users, networks of African health education providers, and the international OER community. The successful 2010 Network grant proposal to the William and Flora Hewlett Foundation included a preliminary logic model and proposed a set of indicators for the first two years of the Network. This working paper reflects a revised understanding of how to promote OER to support health education in Africa, how to demonstrate the impact of OER on the health education sector, and when to expect various outcomes.William and Flora Hewlett Foundationhttps://deepblue.lib.umich.edu/bitstream/2027.42/149179/1/2011.05.09_health_oer_network_impactresearchplan.pdfDescription of 2011.05.09_health_oer_network_impactresearchplan.pdf : Working Document (May 2011) (PDF

Integrated Surveys of Neglected Tropical Diseases in Southern Sudan: How Much Do They Cost and Can They Be Refined?

Control of neglected tropical diseases (NTDs) is suggested to be more cost-effective when drugs are co-administered through a single integrated delivery system rather than separate systems. An essential prerequisite for such efficiency gains is sufficient geographical overlap of the targeted diseases – lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminth infection and trachoma. Lack of data on geographical NTD distribution currently hampers the implementation of integrated control in many African countries. To generate the required data quickly and efficiently, integrated surveys of several NTDs simultaneously have been recommended. However, experience with integrated surveys is limited and requires additional research on cost and effectiveness to inform improvements in methodology and to guide scale-up. Here we analyse costs of the first integrated NTD survey round in Southern Sudan, generating average costs per implementation unit surveyed. Cost estimates are presented for use of the existing survey method and for modified versions. Key cost drivers were survey consumables and personnel, both of which are recurrent costs. These inputs could be reduced or put to more efficient use by modifying sampling for LF. To generate comparable cost estimates and identify key cost drivers in other settings we provide detailed cost data and guidance on how to replicate this work

Restricting Dosage Compensation Complex Binding to the X Chromosomes by H2A.Z/HTZ-1

Dosage compensation ensures similar levels of X-linked gene products in males (XY or XO) and females (XX), despite their different numbers of X chromosomes. In mammals, flies, and worms, dosage compensation is mediated by a specialized machinery that localizes to one or both of the X chromosomes in one sex resulting in a change in gene expression from the affected X chromosome(s). In mammals and flies, dosage compensation is associated with specific histone posttranslational modifications and replacement with variant histones. Until now, no specific histone modifications or histone variants have been implicated in Caenorhabditis elegans dosage compensation. Taking a candidate approach, we have looked at specific histone modifications and variants on the C. elegans dosage compensated X chromosomes. Using RNAi-based assays, we show that reducing levels of the histone H2A variant, H2A.Z (HTZ-1 in C. elegans), leads to partial disruption of dosage compensation. By immunofluorescence, we have observed that HTZ-1 is under-represented on the dosage compensated X chromosomes, but not on the non-dosage compensated male X chromosome. We find that reduction of HTZ-1 levels by RNA interference (RNAi) and mutation results in only a very modest change in dosage compensation complex protein levels. However, in these animals, the X chromosome–specific localization of the complex is partially disrupted, with some nuclei displaying DCC localization beyond the X chromosome territory. We propose a model in which HTZ-1, directly or indirectly, serves to restrict the dosage compensation complex to the X chromosome by acting as or regulating the activity of an autosomal repellant

Uses and Gratifications, Attitudes, and Willingness to Learn Computer Mediated Communication

In order to examine the relationship between age and online communication habits, participants (N = 148) participated in the survey with instruments meant to gauge uses and gratifications, attitudes, and willingness to learn. Results revealed insignificant correlations between age, uses and gratifications, attitudes, and willingness to learn. However, results also showed a negative relationship between age and number of social media sites accessed. Overall, online communication was shown to be used fairly equally among all age groups. The implications of this study will help future researchers understand attitudes, uses and gratifications, and willingness to learn among the different age groups in order to investigate future trends.</p