162 research outputs found

    MoHAT Tool to Illustrate Diode and Transistor Modes of Operation Using LTspice

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    This project develops a tool to identify the modes of operation of diodes and transistors in a circuit. The MoHAT tool receives schematics or circuit files generated from LTspice, and it determines the state of each diode and transistor. This tool illustrates diodes, BJT and MOS regions of operations using text or graphics accordingly. The tool also suggests necessary adjustments to switch from one mode of operation to another upon users request. Furthermore, the tool specifies if a transistor functions in amplification region. The MoHAT tool compares the nodal voltages of an element and determines the mode of operation

    When workplace unionism in global value chains does not function well : exploring the impediments

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    Improving working conditions at the bottom of global value chains has become a central issue in our global economy. In this battle, trade unionism has been presented as a way for workers to make their voices heard. Therefore, it is strongly promoted by most social standards. However, establishing a well-functioning trade union is not as obvious as it may seem. Using a comparative case study approach, we examine impediments to farm-level unionism in the cut flower industry in Ethiopia. For this purpose, we propose an integrated framework combining two lenses, namely a vertical one (governance and structure of global value chains) and a horizontal one (socio-economic context). We identify 10 impediments that point to three major dimensions contributing to unionisation. These three dimensions include awareness of and interest from workers, legitimacy of trade unions, and capacity of trade unions to act. Furthermore, our results suggest that private social standards may, in certain cases, be counterproductive for the efficient functioning of trade unions. Although we argue that there is no ‘quick fix’ solution to weak workplace unionism at the bottom of global value chains, we stress the importance of considering the dynamics of, and interactions between, the impediments when designing potential support measures that mitigate negative impacts

    Relationships between physical activity and other health-related measures using state-based prevalence estimates

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    Background: Both physical activity and muscle-strengthening activity have known relationships with other health-related variables such as alcohol and tobacco use, diet, and health-related quality of life (HRQOL). The purpose of this study was to explore and quantify the associations between physical activity measures and health-related variables at the higher state level. Methods: This cross-sectional study used data from the 2017 and 2019 Behavioral Risk Factor Surveillance System surveys. State-based prevalence (%) estimates were computed for meeting physical activity guidelines (PA), meeting muscle-strengthening activity guidelines (MS), both PA and MS (MB), drinking alcohol (D1), heavy alcohol drinking (HD), fruit consumption (F1), vegetable consumption (V1), good self-rated health (GH), overweight (OW), obesity (OB), current smoking (SN), and smokeless tobacco use (SL). Descriptive statistics, correlation coefficients, and data visualization methods were employed. Results: Strongest associations were seen between PA and F1 (2017: r=0.717 & 2019: r=0.695), MS and OB (2017: r=-0.781 & 2019: r=-0.599), PA and GH (2017: r=0.631 & 2019: r=0.649), PA and OB (2017: r=-0.645 & 2019: r=-0.763), and MB and SN (2017: r=-0.713 & 2019: r=-0.645). V1 was associated only with PA (2017: r=0.335 & 2019: r=0.357) whereas OW was not associated only with PA. Canonical correlation analysis showed the physical activity variables were directly related (r c=0.884, P<0.001) to the health variables. Conclusion: This study used high-level data to support the many known relationships between PA measures and health-related variables

    High seroprevalence of human herpesviruses in HIV-infected individuals attending primary healthcare facilities in rural South Africa

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    Seroprevalence data of human herpesviruses (HHVs) are limited for sub-Saharan Africa. These are important to provide an indication of potential burden of HHV-related disease, in particular in human immunodeficiency virus (HIV)-infected individuals who are known to be at increased risk of these conditions in the Western world. In this cross-sectional study among 405 HIV-infected and antiretroviral therapy naïve individuals in rural South Africa the seroprevalence of HHVs was: herpes simplex virus type 1 (HSV-1) (98%), herpes simplex virus type 2 (HSV-2) (87%), varicella zoster virus (VZV) (89%), and 100% for both Epstein-Barr virus (EBV) and cytomegalovirus (CMV). Independent factors associated with VZV seropositivity were low educational status and having children. Lack of in-house access to drinking water was independently associated with positive HSV-1 serostatus, whereas Shangaan ethnicity was associated with HSV-2 seropositivity. Increasing age was associated with higher IgG titres to both EBV and CMV, whereas CD4 cell count was negatively associated with EBV and CMV IgG titres. Moreover, IgG titres of HSV-1 and 2, VZV and CMV, and CMV and EBV were positively correlated. The high HHV seroprevalence emphasises the importance of awareness of these viral infections in HIV-infected individuals in South Africa

    miRNAs are essential for the regulation of the PI3K/AKT/FOXO pathway and receptor editing during B cell maturation

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    B cell development is a tightly regulated process dependent on sequential rearrangements of immunoglobulin loci that encode the antigen receptor. To elucidate the role of microRNAs (miRNAs) in the orchestration of B cell development, we ablated all miRNAs at the earliest stage of B cell development by conditionally targeting the enzymes critical for RNAi in early B cell precursors. Absence of any one of these enzymes led to a block at the pro- to pre-B cell transition due to increased apoptosis and a failure of pre-B cells to proliferate. Expression of a Bcl2 transgene allowed for partial rescue of B cell development, however, the majority of the rescued B cells had low surface immunoglobulin expression with evidence of ongoing light chain editing. Our analysis revealed that miRNAs are critical for the regulation of the PTEN-AKT-FOXO1 pathway that in turn controls Rag expression during B cell development

    Duration and determinants of birth interval among women of child bearing age in Southern Ethiopia

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    <p>Abstract</p> <p>Background</p> <p>Longer intervals between consecutive births decrease the number of children a woman can have. This results in beneficial effects on population size and on the health status of mothers and children. Therefore, understanding the practice of birth interval and its determinants is helpful to design evidence based strategies for interventions. The objective of this study was to determine duration and determinants of birth interval among women of child bearing age in Lemo district, southern Ethiopia in March 2010.</p> <p>Methods</p> <p>A community based cross sectional study design with stratified multistage sampling technique was employed. A sample of 844 women of child bearing age were selected by using simple random sampling technique after complete census was conducted in selected kebeles prior to data collection. Structured interviewer administered questionnaire was used for data collection. Actual birth interval was measured with the respondents' memory since majority of the women or their children in the area had no birth certificate.</p> <p>Results</p> <p>Majority (57%) of women were practicing short birth interval length with the median birth interval length of 33 months. Actual birth interval length is significantly shorter than preferred birth interval length. Birth interval showed significant variation by contraceptive use, residence, wealth index, breast feeding and occupation of husbands.</p> <p>Conclusion</p> <p>low proportion of optimal birth spacing practices with short actual birth interval length and longer preferred birth interval lengths were evident among the study subjects. Hence interventions to enhance contraceptive utilization behaviors among women in Lemo district would be helpful to narrow the gap between optimal and actual birth spacing.</p

    Provitamin A biofortification of cassava enhances shelf life but reduces dry matter content of storage roots due to altered carbon partitioning into starch

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    Storage roots of cassava (Manihot esculenta Crantz), a major subsistence crop of sub-Saharan Africa, are calorie rich but deficient in essential micronutrients, including provitamin A β-carotene. In this study, β-carotene concentrations in cassava storage roots were enhanced by coexpression of transgenes for deoxy-d-xylulose-5-phosphate synthase (DXS) and bacterial phytoene synthase (crtB), mediated by the patatin-type 1 promoter. Storage roots harvested from field-grown plants accumulated carotenoids to ≤50 lg/g DW, 15- to 20-fold increases relative to roots from nontransgenic plants. Approximately 85%–90% of these carotenoids accumulated as all-trans-β-carotene, the most nutritionally efficacious carotenoid. β-Carotene-accumulating storage roots displayed delayed onset of postharvest physiological deterioration, a major constraint limiting utilization of cassava products. Large metabolite changes were detected in β-carotene-enhanced storage roots. Most significantly, an inverse correlation was observed between β-carotene and dry matter content, with reductions of 50%–60% of dry matter content in the highest carotenoid-accumulating storage roots of different cultivars. Further analysis confirmed a concomitant reduction in starch content and increased levels of total fatty acids, triacylglycerols, soluble sugars and abscisic acid. Potato engineered to co-express DXS and crtB displayed a similar correlation between β-carotene accumulation, reduced dry matter and starch content and elevated oil and soluble sugars in tubers. Transcriptome analyses revealed a reduced expression of genes involved in starch biosynthesis including ADP-glucose pyrophosphorylase genes in transgenic, carotene-accumulating cassava roots relative to nontransgenic roots. These findings highlight unintended metabolic consequences of provitamin A biofortification of starch-rich organs and point to strategies for redirecting metabolic flux to restore starch production

    T-Cell Tropism of Simian Varicella Virus during Primary Infection

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    Varicella-zoster virus (VZV) causes varicella, establishes a life-long latent infection of ganglia and reactivates to cause herpes zoster. The cell types that transport VZV from the respiratory tract to skin and ganglia during primary infection are unknown. Clinical, pathological, virological and immunological features of simian varicella virus (SVV) infection of non-human primates parallel those of primary VZV infection in humans. To identify the host cell types involved in virus dissemination and pathology, we infected African green monkeys intratracheally with recombinant SVV expressing enhanced green fluorescent protein (SVV-EGFP) and with wild-type SVV (SVV-wt) as a control. The SVV-infected cell types and virus kinetics were determined by flow cytometry and immunohistochemistry, and virus culture and SVV-specific real-time PCR, respectively. All monkeys developed fever and skin rash. Except for pneumonitis, pathology produced by SVV-EGFP was less compared to SVV-wt. In lungs, SVV infected alveolar myeloid cells and T-cells. During viremia the virus preferentially infected memory T-cells, initially central memory T-cells and subsequently effector memory T-cells. In early non-vesicular stages of varicella, SVV was seen mainly in perivascular skin infiltrates composed of macrophages, dendritic cells, dendrocytes and memory T-cells, implicating hematogenous spread. In ganglia, S
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