The effect of an exercise programme on the health and well-being of people living with HIV in a rural community of the Eastern Cape

The primary aim of this study was to determine the effect of an 11-week combined progressive resistance exercise and aerobic exercise programme on the health and well-being of a group of participants sampled from an HIV positive rural population. The study was exploratory and quasi-experimental in nature and utilised quantitative research methods. A total number of 37 participants that met the inclusion criteria were included in the study. The participants were assigned to an experimental group (EG) (n=19) based on their willingness to participate in the exercise intervention and the remainder were assigned to the control group (CG) (n=17). The experimental group participated in an 11-week intervention programme which entailed exercising twice a week for the duration of 60 minutes. The intervention entailed a low cost exercise programme which consisted of aerobic exercises (walking, jogging and stepping) and progressive resistance exercises (own body weight, core exercises and light free weight training). The following variables were measured pre-, mid- and post- intervention, namely: health related fitness components, quality of life, physical activity levels and relevant blood variables. An analysis of data was conducted utilising descriptive and inferential statistics. The outcome of the analyses indicated that the EG did not reveal significantly better post-intervention results than the CG in respect of any of the variables assessed. The CG remained sedentary during the intervention period and revealed either an increase in, or maintenance of the initial scores. The slight variation could have been attributed to the decrease in sample size at mid – and post – testing. At the post-intervention testing phase the majority of the participants available for testing were those who were working and healthy. However, it can be concluded that the overall aims and objectives of the study were achieved despite the attrition of participants during the study and that the subsequent outcome of the study was not expected

Changes of renin-angiotensin system-related aminopeptidases in early stage Alzheimer's disease

Activities of aminopeptidases A, B, and N (ApA, ApB & ApN) and insulin-regulated aminopeptidase (IRAP) have been seen to be decreased amongst patients with Alzheimer's disease (AD). All of these enzymes are involved with the brain renin-angiotensin system which is believed to be involved with learning and memory. This study aimed to explore the time course and the mechanisms underlying these changes. Serum samples were collected from 45 AD patients at the start of the study, and again 13 months later (n = 37). The control group was 22 healthy, older, adults. Enzyme activity was determined at two substrate concentrations to allow Michaelis-Menten analysis of the enzyme activity. The results indicated that there was decreased activity of ApA, ApB and ApN amongst AD patients but no difference in serum IRAP activity. There were no associations between enzyme activity and age, gender nor scores on psychomotor tests. Consideration of the data for the two time points for AD patients showed that the changes in ApB occurred at an early stage of the disease and persisted, whilst those of ApA and ApN only became apparent at later stages of the disease. Although differences in Michaelis-Menten parameters were not statistically significant, consideration of the values suggested that the decrease in ApB activity may be a result of changes in enzyme protein conformation, whilst that of ApN may be a consequence of decreased enzyme expression. Importantly, the different time courses of the effects and the differential changes in enzyme affinity and expression indicated that the observed changes with progression of AD were not a ‘class effect’ for serum aminopeptidases but were idiosyncratic for the individual enzymes

Naturally occurring diacetyl and 2,3-pentanedione concentrations associated with roasting and grinding unflavored coffee beans in a commercial setting

AbstractOver the last decade, concerns have been raised about potential respiratory health effects associated with occupational exposure to the flavoring additives diacetyl and 2,3-pentanedione. Both of these diketones are also natural components of many foods and beverages, including roasted coffee. To date, there are no published studies characterizing workplace exposures to these diketones during commercial roasting and grinding of unflavored coffee beans. In this study, we measured naturally occurring diacetyl, 2,3-pentanedione, and respirable dust at a facility that roasts and grinds coffee beans with no added flavoring agents. Sampling was conducted over the course of three roasting batches and three grinding batches at varying distances from a commercial roaster and grinder. The three batches consisted of lightly roasted soft beans, lightly roasted hard beans, and dark roasted hard beans. Roasting occurred for 37 to 41min, and the grinding process took between 8 and 11min. Diacetyl, 2,3-pentanedione, and respirable dust concentrations measured during roasting ranged from less than the limit of detection (<LOD) to 0.0039ppm, <LOD to 0.018ppm, and <LOD to 0.31mg/m3, respectively. During grinding, diacetyl, 2,3-pentanedione, and respirable dust concentrations ranged from 0.018 to 0.39ppm, 0.0089 to 0.21ppm, and <LOD to 1.7mg/m3, respectively. For any given bean/roast combination and sample location, diketone concentrations during grinding were higher than those measured during roasting. During grinding, concentrations decreased with increased distance from the source. Measured concentrations of both diketones were higher during grinding of soft beans than hard beans. The results indicate that airborne concentrations of naturally occurring diacetyl and 2,3-pentanedione associated with unflavored coffee processing: (1) are similar to the concentrations that have been measured in food flavoring facilities; (2) are likely to exceed some recommended short-term occupational exposure limits, but; (3) based on previous analyses of exposure response relationships in animal studies, are far below the concentrations that are expected to cause even minimal responses in the human respiratory tract

Contributions of Stepping Intensity and Variability to Mobility in Individuals Poststroke

Background and Purpose: The amount of task-specific stepping practice provided during rehabilitation post-stroke can influence locomotor recovery, and reflects one aspect of exercise “dose” that can affect the efficacy of specific interventions. Emerging data suggest that markedly increasing the intensity and variability of stepping practice may also be critical, although such strategies are discouraged during traditional rehabilitation. The goal of this study was to determine the individual and combined contributions of intensity and variability of stepping practice to improving walking speed and distance in individuals post-stroke. Methods: This Phase 2, randomized, blinded assessor clinical trial was performed between May 2015-November 2018. Individuals between 18-85 years old with hemiparesis post-stroke of >6 months duration were recruited. Of the 152 individuals screened, 97 were randomly assigned to 1 of 3 training groups, with 90 completing >10 sessions. Interventions consisted of either high intensity stepping (70-80% heart rate [HR] reserve) of variable, difficult stepping tasks (high-variable), high intensity stepping performing only forward walking (high-forward), and low intensity stepping in variable contexts at 30-40% HR reserve (low-variable). Participants received up to 30 sessions over 2 months, with testing at baseline, post-training and a 3-month follow-up. Primary outcomes included walking speeds and timed distance, with secondary measures of dynamic balance, transfers, spatiotemporal kinematics and metabolic measures. Results: All walking gains were significantly greater following either high-intensity group vs low-variable training (all p<0.001) with significant correlations with stepping amount and rate (r=0.48-60; p<0.01). Additional gains in spatiotemporal symmetry were observed with high-intensity training, and balance confidence increased only following high-variable training in individuals with severe impairments. Conclusion: High intensity stepping training resulted in greater improvements in walking ability and gait symmetry than low-intensity training in individuals with chronic stroke, with potential greater improvements in balance confidence

Sediment accumulation rates in subarctic lakes: Insights into age-depth modeling from 22 dated lake records from the Northwest Territories, Canada

Age-depth modeling using Bayesian statistics requires well-informed prior information about the behavior of sediment accumulation. Here we present average sediment accumulation rates (represented as deposition times, DT, in yr/cm) for lakes in an Arctic setting, and we examine the variability across space (intra- and inter-lake) and time (late Holocene). The dataset includes over 100 radiocarbon dates, primarily on bulk sediment, from 22 sediment cores obtained from 18 lakes spanning the boreal to tundra ecotone gradients in subarctic Canada. There are four to twenty-five radiocarbon dates per core, depending on the length and character of the sediment records. Deposition times were calculated at 100-year intervals from age-depth models constructed using the 'classical' age-depth modeling software Clam. Lakes in boreal settings have the most rapid accumulation (mean DT 20±10 yr/cm), whereas lakes in tundra settings accumulate at moderate (mean DT 70±10 yr/cm) to very slow rates, (>100yr/cm). Many of the age-depth models demonstrate fluctuations in accumulation that coincide with lake evolution and post-glacial climate change. Ten of our sediment cores yielded sediments as old as c. 9000cal BP (BP=years before AD 1950). From between c. 9000cal BP and c. 6000cal BP, sediment accumulation was relatively rapid (DT of 20-60yr/cm). Accumulation slowed between c. 5500 and c. 4000cal BP as vegetation expanded northward in response to warming. A short period of rapid accumulation occurred near 1200cal BP at three lakes. Our research will help inform priors in Bayesian age modeling

Socioeconomic Inequality in the Prevalence of Autism Spectrum Disorder: Evidence from a U.S. Cross-Sectional Study

This study was designed to evaluate the hypothesis that the prevalence of autism spectrum disorder (ASD) among children in the United States is positively associated with socioeconomic status (SES).A cross-sectional study was implemented with data from the Autism and Developmental Disabilities Monitoring Network, a multiple source surveillance system that incorporates data from educational and health care sources to determine the number of 8-year-old children with ASD among defined populations. For the years 2002 and 2004, there were 3,680 children with ASD among a population of 557,689 8-year-old children. Area-level census SES indicators were used to compute ASD prevalence by SES tertiles of the population.Prevalence increased with increasing SES in a dose-response manner, with prevalence ratios relative to medium SES of 0.70 (95% confidence interval [CI] 0.64, 0.76) for low SES, and of 1.25 (95% CI 1.16, 1.35) for high SES, (P<0.001). Significant SES gradients were observed for children with and without a pre-existing ASD diagnosis, and in analyses stratified by gender, race/ethnicity, and surveillance data source. The SES gradient was significantly stronger in children with a pre-existing diagnosis than in those meeting criteria for ASD but with no previous record of an ASD diagnosis (p<0.001), and was not present in children with co-occurring ASD and intellectual disability.The stronger SES gradient in ASD prevalence in children with versus without a pre-existing ASD diagnosis points to potential ascertainment or diagnostic bias and to the possibility of SES disparity in access to services for children with autism. Further research is needed to confirm and understand the sources of this disparity so that policy implications can be drawn. Consideration should also be given to the possibility that there may be causal mechanisms or confounding factors associated with both high SES and vulnerability to ASD

Characterization of naturally occurring airborne diacetyl concentrations associated with the preparation and consumption of unflavored coffee

AbstractDiacetyl, a suspected cause of respiratory disorders in some food and flavorings manufacturing workers, is also a natural component of roasted coffee. We characterized diacetyl exposures that would plausibly occur in a small coffee shop during the preparation and consumption of unflavored coffee. Personal (long- and short-term) and area (long-term) samples were collected while a barista ground whole coffee beans, and brewed and poured coffee into cups. Simultaneously, long-term personal samples were collected as two participants, the customers, drank one cup of coffee each per h. Air sampling and analyses were conducted in accordance with OSHA Method 1012. Diacetyl was detected in all long-term samples. The long-term concentrations for the barista and area samples were similar, and ranged from 0.013–0.016ppm; long-term concentrations for the customers were slightly lower and ranged from 0.010–0.014ppm. Short-term concentrations ranged from below the limit of detection (<0.0047ppm)–0.016ppm. Mean estimated 8h time-weighted average (8h TWA) exposures for the barista ranged from 0.007–0.013ppm; these values exceed recommended 8h TWA occupational exposure limits (OELs) for diacetyl and are comparable to long-term personal measurements collected in various food and beverage production facilities. The concentrations measured based on area sampling were comparable to those measured in the breathing zone of the barista, thus exceedances of the recommended OELs may also occur for coffee shop workers who do not personally prepare coffee (e.g., cashier, sanitation/maintenance). These findings suggest that the practicality and scientific basis of the recommended OELs for diacetyl merit further consideration

Task-Specific Versus Impairment-Based Training on Locomotor Performance in Individuals with Chronic Spinal Cord Injury: A Randomized Crossover Study

Background. Many research studies attempting to improve locomotor function following motor incomplete spinal cord injury (iSCI) focus on providing stepping practice. However, observational studies of physical therapy strategies suggest the amount of stepping practice during clinical rehabilitation is limited; rather, many interventions focus on mitigating impairments underlying walking dysfunction. Objective. The purpose of this blinded-assessor randomized trial was to evaluate the effects of task-specific versus impairment-based interventions on walking outcomes in individuals with iSCI. Methods. Using a crossover design, ambulatory participants with iSCI \u3e1-year duration performed either task-specific (upright stepping) or impairment-based training for up to 20 sessions over ≤6 weeks, with interventions alternated after \u3e4 weeks delay. Both strategies focused on achieving higher cardiovascular intensities, with training specificity manipulated by practicing only stepping practice in variable contexts or practicing tasks targeting impairments underlying locomotor dysfunction (strengthening, balance tasks, and recumbent stepping). Results. Significantly greater increases in fastest overground and treadmill walking speeds were observed following task-specific versus impairment-based training, with moderate associations between differences in amount of practice and outcomes. Gains in balance confidence were also observed following task-specific vs impairment-based training, although incidence of falls was also increased with the former protocol. Limited gains were observed with impairment-based training except for peak power during recumbent stepping tests. Conclusion. The present study reinforces work from other patient populations that the specificity of task practice is a critical determinant of locomotor outcomes and suggest impairment-based exercises may not translate to improvements in functional tasks