Life expectancy of persons receiving combination antiretroviral therapy in low-income countries: a cohort analysis from Uganda

Little is known about the effect of combination antiretroviral therapy (cART) on life expectancy in sub-Saharan Africa

Probing background ionization: Positive streamers with varying pulse repetition rate and with a radioactive admixture

Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive Krypton 85. We find that the general morphology of a positive streamer discharge in high purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding Krypton 85, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when the repetition rate and therefore the background ionization level is higher. When measuring the effects of the pulse repetition rate and of the radioactive admixture on the discharge morphology, we found that our estimates of background ionization levels are consistent with these observations; this gives confidence in the estimates. Streamer channels generally do not follow the paths of previous discharge channels for repetition rates of up to 10 Hz. We estimate the effect of recombination and diffusion of ions and free electrons from the previous discharge and conclude that the old trail has largely disappeared at the moment of the next voltage pulse; therefore the next streamers indeed cannot follow the old trail.Comment: 30 pages, 13 figure

Overview of data-synthesis in systematic reviews of studies on outcome prediction models

Background: Many prognostic models have been developed. Different types of models, i.e. prognostic factor and outcome prediction studies, serve different purposes, which should be reflected in how the results are summarized in reviews. Therefore we set out to investigate how authors of reviews synthesize and report the results of primary outcome prediction studies. Methods: Outcome prediction reviews published in MEDLINE between October 2005 and March 2011 were eligible and 127 Systematic reviews with the aim to summarize outcome prediction studies written in English were identified for inclusion. Characteristics of the reviews and the primary studies that were included were independently assessed by 2 review authors, using standardized forms. Results: After consensus meetings a total of 50 systematic reviews that met the inclusion criteria were included. The type of primary studies included (prognostic factor or outcome prediction) was unclear in two-thirds of the reviews. A minority of the reviews reported univariable or multivariable point estimates and measures of dispersion from the primary studies. Moreover, the variables considered for outcome prediction model development were often not reported, or were unclear. In most reviews there was no information about model performance. Quantitative analysis was performed in 10 reviews, and 49 reviews assessed the primary studies qualitatively. In both analyses types a range of different methods was used to present the results of the outcome prediction studies. Conclusions: Different methods are applied to synthesize primary study results but quantitative analysis is rarely performed. The description of its objectives and of the primary studies is suboptimal and performance parameters of the outcome prediction models are rarely mentioned. The poor reporting and the wide variety of data synthesis strategies are prone to influence the conclusions of outcome prediction reviews. Therefore, there is much room for improvement in reviews of outcome prediction studies. (aut.ref.

Serving Their Needs: A Qualitative Examination of Nutrition Policy Implementation in the Early Care and Education Setting

Background: Childhood obesity is a growing problem in the United States and results in increased risk for chronic diseases such as diabetes, heart disease, and hypertension. Thirteen percent of youth in Georgia are obese. Identifying strategies to assist children in establishing healthy habits is essential to reduce the risk of childhood obesity. The Early Care and Education (ECE) setting is ideal for the implementation of obesity prevention practices. However, there are barriers present for implementing nutrition policies in this setting. This report explores the implementation of food and beverage best practices in the ECE setting and highlights barriers to and facilitators for adopting these policies. Methods: We conducted 24 interviews and 6 focus groups with ECE program directors and teachers in 6 regions in Georgia. The statewide sample included directors from child care learning centers, family child care homes, and license-exempt programs. A trained qualitative researcher facilitated focus groups and interviews. Data were audio recorded and transcribed verbatim. Qualitative data analysis software, NVivo 10, was used to code data and identify emergent themes. Results: Several key themes related to barriers to food and beverage policy implementation emerged including the need for: 1) enhanced parent communication, 2) resources to limit juice consumption, and 3) financial support to decrease food costs. Facilitators of nutrition policy implementation included: 1) ease of access to water, 2) children’s preferences for fruits and vegetables, and 3) availability of existing nutrition resources. Findings will inform the development of resources to support nutrition policy implementation as well as policy training for ECE teachers in Georgia. Conclusions: Study themes may provide insight about how to improve current resources and develop new solutions to improve adoption and implementation of nutrition policies in the ECE setting in the future

A scoping review of market links between value chain actors and small-scale producers in developing regions

Sustainable Development Goal 2 aims to end hunger, achieve food and nutrition security and promote sustainable agriculture by 2030. This requires that small-scale producers be included in, and benefit from, the rapid growth and transformation under way in food systems. Small-scale producers interact with various actors when they link with markets, including product traders, logistics firms, processors and retailers. The literature has explored primarily how large firms interact with farmers through formal contracts and resource provision arrangements. Although important, contracts constitute a very small share of smallholder market interactions. There has been little exploration of whether non-contract interactions between small farmers and both small- and large-scale value chain actors have affected small farmers’ livelihoods. This scoping review covers 202 studies on that topic. We find that non-contract interactions, de facto mostly with small and medium enterprises, benefit small-scale producers via similar mechanisms that the literature has previously credited to large firms. Small and medium enterprises, not just large enterprises, address idiosyncratic market failures and asset shortfalls of small-scale producers by providing them, through informal arrangements, with complementary services such as input provision, credit, information and logistics. Providing these services directly supports Sustainable Development Goal 2 by improving farmer welfare through technology adoption and greater productivity

Association of elevated serum aminotransferase levels with chronic kidney disease measures: hispanic community health study/study of latinos

Background Previous studies have shown an association between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD), but it is unclear whether the association is independent of metabolic syndrome. Methods Data from 13,006 participants aged 18 to 74 years in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) without viral hepatitis, excessive alcohol consumption, or high transferrin saturation levels were analyzed. Suspected NAFLD was defined as presence of sex-specific elevations in serum aminotransferase levels (aspartate aminotransferase (AST) > 37 U/L or alanine aminotransferase (ALT) > 40 U/L for men and AST or ALT > 31 U/L for women). Logistic regression was used to examine cross-sectional associations of elevated serum aminotransferase levels with low estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m2 based on cystatin C), and with high urinary albumin-to-creatinine ratio (UACR) (> 17 mg/g in men and > 25 mg/ g in women) in separate models adjusting for demographic characteristics and metabolic syndrome. Results Mean (SD) age was 41 (0.27) years, and 45 % were male. Elevated serum aminotransferase levels were noted in 18.8 % of the population and were associated with greater odds of high UACR (OR = 1.31; 95 % CI = 1.10, 1.56) after adjusting for demographic characteristics; this association became non-significant after adjustment for metabolic syndrome (OR = 1.11, 95 % CI = 0.92, 1.33). In contrast, elevated serum aminotransferase levels were not associated with low eGFR (odds ratio (OR) = 0.73; 95 % confidence interval (CI) = 0.45, 1.18) after adjusting for covariates. Conclusions In this sample of diverse U.S. Hispanic Latino adults, elevated serum aminotransferase levels were not independently associated with measures of CKD

Cardiovascular disease and risk of incident diabetes mellitus: Findings from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

BACKGROUND: Studies have reported an association between prevalent cardiovascular disease (CVD) and risk of diabetes mellitus (DM). However, factors that may explain the association remain unclear. We examined the association of prevalent CVD with incident DM and assessed whether weight gain and medication use may explain the association. METHODS: Data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Visit 1 (2008-2011) and Visit 2 (2014-2017) were used to compare incidence of DM among individuals with and without self-reported CVD at Visit 1. A total of 1899 individuals with self-reported CVD were matched to controls free of self-reported CVD at Visit 1 using 1:1 propensity score matching. Covariates included in the propensity model were sociodemographic characteristics, lifestyle factors, comorbid conditions, and study site. The effect of self-reported CVD on incident DM was examined using a generalized estimating equation. The mediating effects of weight gain and use of cardiovascular medications were evaluated. RESULTS: Covariate distributions were similar among individuals with and without self-reported CVD. The incidence of DM among persons with self-reported CVD was 15.3% vs 12.7% among those without self-reported CVD. Compared to individuals without self-reported CVD, individuals with self-reported CVD had a 24% increased risk for incident DM (odds ratio = 1.24, 95% confidence interval = 1.01, 1.51). The association between self-reported CVD and DM was mediated by the use of beta-blockers (proportion explained = 25.4%), statins (proportion explained = 18%), and diuretics (proportion explained = 8%). We found that weight gain did not explain the observed association. CONCLUSIONS: Prevalent cardiovascular disease was associated with a significant increased risk of incident diabetes. The observed association was partially explained by some medications used to manage CVD