5,253 research outputs found

    Family Size and Socioeconomic Status in Humla District, Nepal

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    In a remote district of Nepal in the Himalayas, known as Humla District, increased access to health care and contraception in the past decade have given village families more options for family planning. In other research on health seeking, socioeconomic status indicators such as household education level, months of food security, and occupation have been associated with contraceptive behaviors. Based on theories related to demographic and health transitions, we hypothesized that families with higher socioeconomic statuses were more likely to have lower fertility. Multiple regressions of a handful of indicators of socioeconomic status derived from ethnographic and survey data collected between 2003 and 2013 in Humla District revealed that decision making about health and family size is fairly complex, and is related to a handful of factors. Based on this knowledge of the region, where livelihoods depend on labor for agricultural pursuits but fertile land is not widely available for expansion, decisions to limit family size have wide-ranging repercussions. We discuss variations in barriers to health seeking in multiple villages of Humla District, and their implications for the future of family planning and health development in Humla District. This project was conducted using research acquired through surveys of villagers. Questions regarding their ideas of wealth, their ability to reach clinics when sick, socioeconomic status indicators, and family size were used to reach conclusions about this topic. This approach is unique because it asks villagers themselves what they value and consider to be signs of wealth, prosperity, and success, and uses that information to deduce what it is that they need in order to thrive in their communities. It examines how and why families with more socioeconomic status would desire a smaller family size, and why that may be beneficial in these villages

    CD4+CD25+ T regulatory cells from FIV+ cats induce a unique anergic profile in CD8+ lymphocyte targets

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    Abstract Background Using the FIV model, we reported previously that CD4+CD25+ T regulatory (Treg) cells from FIV+ cats are constitutively activated and suppress CD4+CD25- and CD8+ T cell immune responses. In an effort to further explore Treg-mediated suppression, we asked whether Treg cells induce anergy through the alteration of production of cyclins, cyclin-dependent kinases and their inhibitors. Results Lymphocytes were obtained from control or FIV+ cats and sorted by FACS into CD4+CD25+ and CD8+ populations. Following co-culture with CD4+CD25+ cells, CD8+ targets were examined by Western blot for changes in cyclins D3, E and A, retinoblastoma (Rb) protein, as well as the cyclin dependent kinase inhibitor p21cip1. Following co-culture with CD4+CD25+cells, we observed up-regulation of p21cip1 and cyclin E, with down-regulation of cyclin D3, in CD8+ cells from FIV+ cats. As expected, CD8+ targets from control cats were quiescent with little up-regulation of p21cip1 and cyclin E. There was also a lack of Rb phosphorylation in CD8+ targets consistent with late G1 cell cycle arrest. Further, IL-2 mRNA was down regulated in CD8+ cells after co-culture with CD4+CD25+ Treg cells. Following CD4+CD25+ co-culture, CD8+ targets from FIV+ cats also had increased Foxp3 mRNA expression; however, these CD8+Foxp3+ cells did not exhibit suppressor function. Conclusions Collectively, these data suggest that CD4+CD25+ Treg cells from FIV+ cats induce CD8+ anergy by disruption of normal G1 to S cell cycle progression.</p

    Different thresholds of T cell activation regulate FIV infection of CD4+CD25+ and CD4+CD25− cells

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    AbstractCellular activation plays an important role in retroviral replication. Previously, we have shown that CD4+CD25+ T cells by the virtue of their partially activated phenotype represent ideal candidates for a productive feline immunodeficiency virus (FIV) infection. In the present study, we extended our previous observations with regard to FIV replication in CD4+CD25+ and CD4+CD25− cells under different stimulation conditions. Both CD4+CD25+ and CD4+CD25− cells remain latently infected in the absence of IL-2 or concanvalinA (ConA), respectively; harboring a replication competent provirus capable of reactivation several days post-infection. While CD4+CD25+ cells require low levels of exogenous IL-2 and virus inputs for an efficient FIV replication, CD4+CD25− T cells can only be productively infected in the presence of either high concentrations of IL-2 or high virus titers, even in the absence of mitogenic stimulation. Interestingly, while high virus input activates CD4+CD25− cells to replicate FIV, it induces apoptosis in a high percentage of CD4+CD25+ T cells. High IL-2 concentrations but not high virus inputs lead to surface upregulation of CD25 and significant cellular proliferation in CD4+CD25− cells. These results suggest that CD4+CD25+ and CD4+CD25− T cells have different activation requirements which can be modulated by both viral and cytokine stimuli to reach threshold activation levels in order to harbor a productive FIV infection. This holds implications in vivo for CD4+CD25+ and CD4+CD25− cells to serve as potential reservoirs of a productive and latent FIV infection

    Influence of random roughness on the Casimir force at small separations

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    The influence of random surface roughness of Au films on the Casimir force is explored with atomic force microscopy in the plate-sphere geometry. The experimental results are compared to theoretical predictions for separations ranging between 20 and 200 nm. The optical response and roughness of the Au films were measured and used as input in theoretical predictions. It is found that at separations below 100 nm, the roughness effect is manifested through a strong deviation from the normal scaling of the force with separation distance. Moreover, deviations from theoretical predictions based on perturbation theory can be larger than 100%.Comment: 18, 5 figure

    Child Psychosocial Adjustment and Parenting in Families Affected by Maternal HIV/AIDS

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    Child adjustment and parenting were examined in 23 9-through 16-year-old youth from families affected by maternal HIV infection and 20 same-age peers whose mothers were not infected. Children whose mothers were seropositive reported significantly more externalizing problems. Infected mothers reported less age-appropriate supervision/monitoring relative to non-infected mothers. Better mother-child relationship quality and less impairment in parental supervision/monitoring of age-appropriate youth behaviors were associated with fewer externalizing difficulties among the HIV-positive group only. Similarly, only among HIV-infected mothers was refraining from engaging in inconsistent disciplinary tactics associated with lower reports of internalizing and externalizing problems. These data highlight the promise of programs targeting parenting skills to prevent or ameliorate child difficulties

    Adiabaticity Conditions for Volatility Smile in Black-Scholes Pricing Model

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    Our derivation of the distribution function for future returns is based on the risk neutral approach which gives a functional dependence for the European call (put) option price, C(K), given the strike price, K, and the distribution function of the returns. We derive this distribution function using for C(K) a Black-Scholes (BS) expression with volatility in the form of a volatility smile. We show that this approach based on a volatility smile leads to relative minima for the distribution function ("bad" probabilities) never observed in real data and, in the worst cases, negative probabilities. We show that these undesirable effects can be eliminated by requiring "adiabatic" conditions on the volatility smile
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