A Qualitative Study of Perceived Risk for HIV Transmission among Police Officers in Dar es Salaam, Tanzania.

Understanding people's views about HIV transmission by investigating a specific population may help to design effective HIV prevention strategies. In addition, knowing the inherent sexual practices of such a population, as well as the risky circumstances that may facilitate HIV transmission, is crucial for the said strategies to become effective. In this article, we report how police officers in Dar es Salaam, Tanzania, perceived the problem of HIV and AIDS in their local context, particularly in relation to unsafe sexual practices. The study was done with the view to recommending ways by which HIV transmission could be minimised within the police force. The study was conducted among members of the police force in Dar es Salaam, Tanzania. Eight focus group discussions (FGDs) were conducted, with a total of 66 participants who were mixed in terms of age, gender, and marital status. Some of these were caregivers to patients with AIDS. Data were analysed using the interpretive description approach. The participants believed that both individual sexual behaviour and work-related circumstances were sources of HIV infection. They also admitted that they were being tempted to engage in risky sexual practices because of the institutional rules that prohibit officers from getting married during their training and for three years after. Nevertheless, as members of the Police Force, they stressed the fact that the risky sexual behaviour that exposes them to HIV is not limited to the force; it is rather a common problem that is faced by the general population. However, they complained, the nature of their job exposes them to road accident victims, subjecting them further to possible infection, especially when they have to handle these road accident casualties without proper protective gear. Individual sexual behaviour and job-related circumstances are worth investigating if proper advice is to be given to the police regarding HIV prevention strategies. In order to improve the lives of these police officers, there is a need to review the existing institutional rules and practices to accommodate individual sexual needs. In addition, improving their working environment may minimize the risk of HIV transmission from handling casualties in emergency situations

Sparse Randomized Kaczmarz for Support Recovery of Jointly Sparse Corrupted Multiple Measurement Vectors

While single measurement vector (SMV) models have been widely studied in signal processing, there is a surging interest in addressing the multiple measurement vectors (MMV) problem. In the MMV setting, more than one measurement vector is available and the multiple signals to be recovered share some commonalities such as a common support. Applications in which MMV is a naturally occurring phenomenon include online streaming, medical imaging, and video recovery. This work presents a stochastic iterative algorithm for the support recovery of jointly sparse corrupted MMV. We present a variant of the Sparse Randomized Kaczmarz algorithm for corrupted MMV and compare our proposed method with an existing Kaczmarz type algorithm for MMV problems. We also showcase the usefulness of our approach in the online (streaming) setting and provide empirical evidence that suggests the robustness of the proposed method to the distribution of the corruption and the number of corruptions occurring.Comment: 13 pages, 6 figure

Irradiation-induced localization of IL-12-expressing mesenchymal stem cells to enhance the curative effect in murine metastatic hepatoma

Irradiation in conjunction with gene therapy is considered for efficient cancer treatment. Mesenchymal stem cells (MSCs), due to their irradiation-promotable tumor tropism, are ideal delivery vehicles for gene therapy. In this study, we investigated whether treatment with radiation and interleukin (IL)-12-expressing MSCs (MSCs/IL-12) exerts improved antitumor effects on murine metastatic hepatoma. HCa-I and Hepa 1-6 cells were utilized to generate heterotopic murine hepatoma models. Tumor-bearing mice were treated with irradiation or MSCs/IL-12 alone, or a combination. Monocyte chemoattractant protein-1 (MCP-1/CCL2) expression was assessed in irradiated hepatoma tissues to confirm a chemotactic effect. Combination treatment strategies were established and their therapeutic efficacies were evaluated by monitoring tumor growth, metastasis and survival rate. IL-12 expression was assessed and the apoptotic activity and immunological alterations in the tumor microenvironment were examined. MCP-1/CCL2 expression and localization of MSCs/IL-12 increased in the irradiated murine hepatoma cells. The antitumor effects, including suppression of pulmonary metastasis and survival rate improvements, were increased by the combination treatment with irradiation and MSCs/IL-12. IL-12 expression was increased in tumor cells, causing proliferation of cluster of differentiation 8(+) T-lymphocytes and natural killer cells. The apoptotic activity increased, indicating that the cytotoxicity of immune cells was involved in the antitumor effect of the combined treatment. Treatment with irradiation and MSCs/IL-12 showed effectiveness in treating murine metastatic hepatoma. IL-12-induced proliferation of immune cells played an important role in apoptosis of tumor cells. Our results suggest that treatment with irradiation and MSCs/IL-12 may be a useful strategy for enhancing antitumor activity in metastatic hepatoma. What's new? Mesenchymal stem cells (MSCs) are promising gene-delivery vehicles, with the potential to improve antitumor effects when used in combination with existing therapies. In the present study, the combined use of interleukin (IL)-12-expressing MSCs (MSCs/IL-12) and radiation therapy increased antitumor activity in murine metastatic hepatoma, a model that is representative of human metastatic hepatocellular carcinoma (HCC), which affects nearly half of HCC patients. Treatment with MSCs/IL-12 resulted in increased IL-12 expression in tumor cells and immune cell proliferation. Immune cell cytotoxicity, evidenced by increased apoptotic activity, appeared to play a role in MSCs/IL-12 augmentation of antitumor effects.1178Ysciescopu

A network ridesharing experiment with sequential choice of transportation mode

Within the last decade, there has been a dramatic bloom in ridesharing businesses along with the emergence of new enabling technologies. A central issue in ridesharing, which is also important in the general domain of cost-sharing in economics and computer science, is that the sharing of cost implies positive externalities and hence coordination problems for the network users. We investigate these problems experimentally in the present study. In particular, we focus on how sequential observability of transportation mode choices can be a powerful facilitator of coordination in ridesharing. Our study abstracts the essential issues of coordination in ridesharing into a directed network game with experimentally testable predictions. In line with the theoretical analysis, our experimental evidence shows that even a limited extent of sequential choice observability might lead to efficient coordination. However, convergence to efficiency is slower with more limited observability, resulting in a significant increase in travel cost

Collaborative Gaze Channelling for Improved Cooperation During Robotic Assisted Surgery

The use of multiple robots for performing complex tasks is becoming a common practice for many robot applications. When different operators are involved, effective cooperation with anticipated manoeuvres is important for seamless, synergistic control of all the end-effectors. In this paper, the concept of Collaborative Gaze Channelling (CGC) is presented for improved control of surgical robots for a shared task. Through eye tracking, the fixations of each operator are monitored and presented in a shared surgical workspace. CGC permits remote or physically separated collaborators to share their intention by visualising the eye gaze of their counterparts, and thus recovers, to a certain extent, the information of mutual intent that we rely upon in a vis-à-vis working setting. In this study, the efficiency of surgical manipulation with and without CGC for controlling a pair of bimanual surgical robots is evaluated by analysing the level of coordination of two independent operators. Fitts' law is used to compare the quality of movement with or without CGC. A total of 40 subjects have been recruited for this study and the results show that the proposed CGC framework exhibits significant improvement (p<0.05) on all the motion indices used for quality assessment. This study demonstrates that visual guidance is an implicit yet effective way of communication during collaborative tasks for robotic surgery. Detailed experimental validation results demonstrate the potential clinical value of the proposed CGC framework. © 2012 Biomedical Engineering Society.link_to_subscribed_fulltex

Suppression of photoconductivity by magnetic field in epitaxial manganite thin films

The erasure of photoinduced resistance (PR) by the magnetic field was investigated in manganite films. The PR was significantly suppressed when a magnetic field was introduced at low temperature. The decrease (or increase) of PR with increment of magnetic field was observed in ferromagnetic (or paramagnetic) phases of films, respectively. Our results are suggested to be the coaction of two effects under magnetic fields: (i) the reorientation of domains and spin directions of photoexcited carriers and (ii) electrons trapped around oxygen vacancies released and recombined with majority carriers in films. The interplay of the external fields is a good demonstration of the strong coupling between spins and charges in colossal magnetoresistance materials. © 2012 American Institute of Physics.published_or_final_versio

Small intestinal eosinophils regulate Th17 cells by producing IL-1 receptor antagonist

Eosinophils play proinflammatory roles in helminth infections and allergic diseases. Under steady-state conditions, eosinophils are abundantly found in the small intestinal lamina propria, but their physiological function is largely unexplored. In this study, we found that small intestinal eosinophils down-regulate Th17 cells. Th17 cells in the small intestine were markedly increased in the Delta dblGATA-1 mice lacking eosinophils, and an inverse correlation was observed between the number of eosinophils and that of Th17 cells in the small intestine of wild-type mice. In addition, small intestinal eosinophils suppressed the in vitro differentiation of Th17 cells, as well as IL-17 production by small intestinal CD4(+) T cells. Unlike other small intestinal immune cells or circulating eosinophils, we found that small intestinal eosinophils have a unique ability to constitutively secrete high levels of IL-1 receptor antagonist (IL-1Ra), a natural inhibitor of IL-1 beta. Moreover, small intestinal eosinophils isolated from IL-1Ra-deficient mice failed to suppress Th17 cells. Collectively, our results demonstrate that small intestinal eosinophils play a pivotal role in the maintenance of intestinal homeostasis by regulating Th17 cells via production of IL-1Ra.open111815sciescopu

Expression quantitative trait loci are highly sensitive to cellular differentiation state

Blood cell development from multipotent hematopoietic stem cells to specialized blood cells is accompanied by drastic changes in gene expression for which the triggers remain mostly unknown. Genetical genomics is an approach linking natural genetic variation to gene expression variation, thereby allowing the identification of genomic loci containing gene expression modulators (eQTLs). In this paper, we used a genetical genomics approach to analyze gene expression across four developmentally close blood cell types collected from a large number of genetically different but related mouse strains. We found that, while a significant number of eQTLs (365) had a consistent “static” regulatory effect on gene expression, an even larger number were found to be very sensitive to cell stage. As many as 1,283 eQTLs exhibited a “dynamic” behavior across cell types. By looking more closely at these dynamic eQTLs, we show that the sensitivity of eQTLs to cell stage is largely associated with gene expression changes in target genes. These results stress the importance of studying gene expression variation in well-defined cell populations. Only such studies will be able to reveal the important differences in gene regulation between different ce

Intra- and inter-individual genetic differences in gene expression

Genetic variation is known to influence the amount of mRNA produced by a gene. Given that the molecular machines control mRNA levels of multiple genes, we expect genetic variation in the components of these machines would influence multiple genes in a similar fashion. In this study we show that this assumption is correct by using correlation of mRNA levels measured independently in the brain, kidney or liver of multiple, genetically typed, mice strains to detect shared genetic influences. These correlating groups of genes (CGG) have collective properties that account for 40-90% of the variability of their constituent genes and in some cases, but not all, contain genes encoding functionally related proteins. Critically, we show that the genetic influences are essentially tissue specific and consequently the same genetic variations in the one animal may up-regulate a CGG in one tissue but down-regulate the same CGG in a second tissue. We further show similarly paradoxical behaviour of CGGs within the same tissues of different individuals. The implication of this study is that this class of genetic variation can result in complex inter- and intra-individual and tissue differences and that this will create substantial challenges to the investigation of phenotypic outcomes, particularly in humans where multiple tissues are not readily available.&#xd;&#xa;&#xd;&#xa

Relating Gauge Theories via Gauge/Bethe Correspondence

In this note, we use techniques from integrable systems to study relations between gauge theories. The Gauge/Bethe correspondence, introduced by Nekrasov and Shatashvili, identifies the supersymmetric ground states of an N=(2,2) supersymmetric gauge theory in two dimensions with the Bethe states of a quantum integrable system. We make use of this correspondence to relate three different quiver gauge theories which correspond to three different formulations of the Bethe equations of an integrable spin chain called the tJ model.Comment: 30 pages, published in JHEP. LaTeX problem correcte