Availability of HIV/AIDS community intervention programmes and quality of services in and around selected mining sites in Tanzania

Background: Mining is one of the major sectors of the country’s economy as it employs and attracts a large number of people from different areas. As a result, mining sites are at great risk of HIV transmission. While a few unsynchronized mine-specific population-based studies provide evidence of a growing HIV problem in this sector, virtually few evidence exists on availability and quality of interventions targeting HIV and AIDS in this population. The study was conducted to assess the availability and quality of HIV/AIDS intervention programmes in and around mining sites in Tanzania.Methods: This cross sectional study was conducted from November 2012 to April 2013. Both quantitative and qualitative methods were used to collect data. Study areas involved both mining sites and its surrounding communities in Kahama, Nzega and Geita Districts. It involved household members from villages in and around the mining sites, mining community relations officers, community health facility workers, district HIV/AIDS focal persons and village leaders.Results: A total of 463 individuals were recruited into the study for household interviews. In-depth interviews with Key Informants involved 15 respondents. HIV/AIDS intervention programmes in the study area were available despite that knowledge of their existence was limited to a segment of the community.  Their availability was only known to about 25% of the study respondents in Geita and Kahama study sites.  The programmes carried out intervention activities which included HIV/AIDS education campaigns, promoting uptake of voluntary counselling and testing services, promoting and supporting condom use, safer sex, and male circumcision. HIV/AIDS services such as screening, distribution of condoms and ARVs for infected people were available and were offered free of charge. Conclusion: Our findings show that HIV/AIDS intervention programmes were available despite that they were unequally distributed. Although their availability has contributed to the decrease of HIV prevalence in the community, knowledge of their availability was limited to some people in the community

Processor allocation on Cplant: Achieving general processor locality using one-dimensional allocation strategies.

Abstract Follows 3 Abstract The Computational Plant or Cplant is a commodity-based supercomputer under development at Sandia National Laboratories. This paper describes resource-allocation strategies to achieve processor locality for parallel jobs in Cplant and other supercomputers. Users of Cplant and other Sandia supercomputers submit parallel jobs to a job queue. When a job is scheduled to run, it is assigned to a set of processors. To obtain maximum throughput, jobs should be allocated to localized clusters of processors to minimize communication costs and to avoid bandwidth contention caused by overlapping jobs. This paper introduces new allocation strategies and performance metrics based on space-filling curves and one dimensional allocation strategies. These algorithms are general and simple. Preliminary simulations and Cplant experiments indicate that both space-filling curves and one-dimensional packing improve processor locality compared to the sorted free list strategy previously used on Cplant. These new allocation strategies are implemented in the new release of the Cplant System Software, Version 2.0, phased into th

Oesophagostominae des Suid\ue9s sauvages d\u27Afrique Centrale

Volume: 184Start Page: 1425End Page: 145

Multi-agent motion planning for nonlinear Gaussian systems

In this paper, a multi-agent motion planner is developed for nonlinear Gaussian systems using a combination of probabilistic approaches and a rapidly exploring random tree (RRT) algorithm. A closed-loop model consisting of a controller and estimation loops is used to predict future distributions to manage the level of uncertainty in the path planner. The closed-loop model assumes the existence of a feedback control law that drives the actual system towards a nominal system. This ensures the uncertainty in the evolution does not grow significantly and the tracking errors are bounded. To trade conservatism with the risk of infeasibility and failure, we use probabilistic constraints to limit the probability of constraint violation. The probability of leaving the configuration space is included by using a chance constraint approach and the probability of closeness between two agents is imposed using an overlapping coefficient approach. We augment these approaches with the RRT algorithm to develop a robust path planner. Conflict among agents is resolved using a priority-based technique. Numerical results are presented to demonstrate the effectiveness of the planner

Dissolution of sputter-deposited iron oxide films used as a model for the passive film on iron

This paper reports results from XANES (X-ray absorption near edge spectroscopy) studies during polarization of thin sputter-deposited Fe-oxide films in acidic solutions. The dissolution rate of Fe-oxides in acidic solutions was found to be strongly increased by the presence of Fe(2+) in the oxide. During anodic polarization in acidic solutions, a deleterious effect of chloride anions is found compared with sulfates. In HCl solutions of increasing concentration, not only the pH decrease, but also the increasing anion concentration accelerates dissolution. On the other hand, the dissolution rate in sulfuric acid does not depend on the sulfate concentration. During cathodic polarization, the dissolution rate is not affected by the presence of chloride ions. This could be due to the negative surface charge of n-type oxides at potentials lower than the flat-band potential, retarding anion adsorption on the surface. These results suggest that the detrimental role of chloride anions on the stability of Fe oxide films is due to a surface complexation effect. The dissolution rate is fairly independent of the potential in the anodic range, except at very high anodic potentials. The XANES spectra reveal no changes in the average oxide valency during anodic polarization. Thus in the passive range, the dissolution that takes place is mostly chemical rather than electrochemical. The findings and their relevance to the stability of natural passive films are discussed

Localized corrosion of GaAs surfaces and formation of porous GaAs

The present work deals with pitting corrosion of p- and n-type GaAs (100). Pit growth can be electrochemically initiated on both conduction types in chloride-containing solutions and leads after extended periods of time to the formation of a porous GaAs structure. In the case of p-type material, localized corrosion is only observed if a passivating film is present on the surface, otherwise -- e.g. in acidic solutions -- the material suffers from a uniform attack (electropolishing) which is independent of the anion present. In contrast, pitting corrosion of n-type material can be triggered independent of the presence of an oxide film. This is explained in terms of the different current limiting factor for the differently doped materials (oxide film in the case of the p- and a space charge layer in the case of the n-GaAs). The porous structure was characterized by SEM, EDX and AES, and consists mainly of GaAs. From scratch experiments it is clear that the pit initiation process is strongly influenced by surface defects. For n-type material, AFM investigations show that light induced roughening of the order of several hundred nm occurs under non-passivating conditions. This nm- scale roughening however does not affect the pitting process.NRC publication: Ye

Systemic Blood Proteome Patterns Reflect Disease Phenotypes in Neovascular Age-Related Macular Degeneration

There is early evidence of extraocular systemic signals effecting function and morphology in neovascular age-related macular degeneration (nAMD). The prospective, cross-sectional BIOMAC study is an explorative investigation of peripheral blood proteome profiles and matched clinical features to uncover systemic determinacy in nAMD under anti-vascular endothelial growth factor intravitreal therapy (anti-VEGF IVT). It includes 46 nAMD patients stratified by the level of disease control under ongoing anti-VEGF treatment. Proteomic profiles in peripheral blood samples of every patient were detected with LC-MS/MS mass spectrometry. The patients underwent extensive clinical examination with a focus on macular function and morphology. In silico analysis includes unbiased dimensionality reduction and clustering, a subsequent annotation of clinical features, and non-linear models for recognition of underlying patterns. The model assessment was performed using leave-one-out cross validation. The findings provide an exploratory demonstration of the link between systemic proteomic signals and macular disease pattern using and validating non-linear classification models. Three main results were obtained: (1) Proteome-based clustering identifies two distinct patient subclusters with the smaller one (n = 10) exhibiting a strong signature for oxidative stress response. Matching the relevant meta-features on the individual patient’s level identifies pulmonary dysfunction as an underlying health condition in these patients. (2) We identify biomarkers for nAMD disease features with Aldolase C as a putative factor associated with superior disease control under ongoing anti-VEGF treatment. (3) Apart from this, isolated protein markers are only weakly correlated with nAMD disease expression. In contrast, applying a non-linear classification model identifies complex molecular patterns hidden in a high number of proteomic dimensions determining macular disease expression. In conclusion, so far unconsidered systemic signals in the peripheral blood proteome contribute to the clinically observed phenotype of nAMD, which should be examined in future translational research on AMD