Examining the association between discrimination and risky social networks among illicit drug users

Discrimination is a predictor of increased drug use initiation. Thus, discrimination may systematically marginalize stigmatized individuals into risky social networks (e.g., networks with high burden of disease) that facilitate HIV transmission. Therefore, even when individual risk behaviors are low, membership in high risk network may perpetuate disease transmission. Studies have shown that black and Hispanic drug users exhibit lower drug and sexual risk behaviors, yet they are most affected by HIV. Since blacks and Hispanics experience discrimination more often than whites, this relationship may explain their increased likelihood of HIV prevalence. In order to assess whether an association between discrimination and risky social networks existed and whether this relationship was modified among blacks and Hispanics, we used data from the Social Ties Associated with Risk of Transition (START) study. START (n=652) is a prospective cohort study among non-injection drug users (never injected and used non-injection heroin/crack/cocaine ≥ year at least 2-3 times/ week) and a cross-sectional sample of newly initiated injection drug users (heroin/crack/cocaine injectors ≤ 3 years) recruited through respondent driven sampling and targeted street outreach in ethnographically mapped high drug activity NYC neighborhoods. We also combined START data with 2000 US Census data to examine whether neighborhood structural factors (e.g., poverty, education, minority composition and social cohesion) exacerbated the relationship between discrimination and risky social networks. Using log-binomial regression and population average modeling for neighborhood analyses, discrimination was shown to be significantly associated with more drug and sexual risk networks. Among blacks, discrimination due to race and drug use were important for having more embedded sex networks. Among whites and Hispanics, discrimination due to incarceration and drug use was significantly associated with embedded heroin and injection networks. Finally, the relationship between drug use discrimination and more embedded heroin and injecting networks was also magnified among illicit drug users that are members of neighborhoods characterized by lower minority composition, less education and poorer social cohesion. More research is needed to better understand the how race/ ethnicity and neighborhood influence the socio-contextual process between discrimination and risky social networks

Social capital and HIV/AIDS in the United States: Knowledge, gaps, and future directions

Purpose Social capital is a well-established predictor of several behavioral health outcomes. However, we know less about the relationship with prevention, transmission, and treatment of HIV/AIDS outcomes in the United States (US). Methods In 2017, we conducted a scoping review of empirical studies investigating the relationships between social capital and HIV/AIDS in the US by searching PubMed, Embase, PsycINFO, Web of Science, and Sociological Abstracts with no restriction on publication date, for articles in English language. Sample search terms included: HIV infections OR HIV OR AIDS OR acquired immunodeficiency syndrome OR human immunodeficiency virus AND social capital OR social control, informal OR social participation OR social cohesion OR generalized trust OR social trust OR collective efficacy OR community mob* OR civic participation. Results We identified 1581 unique manuscripts and reviewed 13 based on eligibility criteria. The earliest eligible study was published in 2003. More than half (n=7/13) focused on HIV or AIDS diagnosis, then prescribing ART and/or adherence (n=5/13), then linkage and or engagement in HIV care (n=4/13). Fifty eight percent (58%) documented a protective association between at least one social capital measure and an HIV/AIDS outcome. Seven studies used validated social capital scales, however there was substantial variation in conceptual/operational definitions and measures used. Most studies were based on samples from the Northeast. Three studies directly focused on or stratified analyses among subgroups or key populations. Studies were cross-sectional, so causal inference is unknown. Conclusion Our review suggests that social capital may be an important determinant of HIV/AIDS prevention, transmission, and treatment outcomes. We recommend future research assess these associations using qualitative and mixed-methods approaches, longitudinally, examine differences across subgroups and geographic region, include a wider range of social capital constructs, and examine indicators beyond HIV diagnosis, as well as how mechanisms like stigma link social capital to HIV/AIDS

Introductory programming: a systematic literature review

As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research

A brief guide to polymer characterization: structure (IUPAC technical report)

To bolster the series of Brief Guides released by International Union of Pure and Applied Chemistry (IUPAC), here we introduce the first Brief Guide to Polymer Characterization. This article provides a concise overview of characterization methods for teachers, students, non-specialists, and newcomers to polymer science as well as being a useful manual for researchers and technicians. Unlike pure low molar mass chemical substances, polymers are not composed of identical molecules. The macromolecules which comprise a single polymer sample vary from one another, primarily in terms of size and shape, but often also in the arrangement or positioning of atoms within macromolecules (e.g., chain branching, isomerism, etc.). Polymer properties are often drastically different from those of other substances and their characterization relies on specialist equipment and/or common equipment used in a specialized way (e.g., particular sample preparation or data analysis). This Brief Guide focuses uniquely on the structural characterization (i.e., analyzing the molecular and multi-molecular aspects) of polymers. The complex nature of the structural variables possible in macromolecular materials often presents a challenge with regard to the detailed structural characterization of polymers. This Brief Guide provides a useful starting point to direct the reader to the most commonly used and useful techniques to characterize these structural variables

Does Respondent Driven Sampling Alter the Social Network Composition and Health-Seeking Behaviors of Illicit Drug Users Followed Prospectively?

Respondent driven sampling (RDS) was originally developed to sample and provide peer education to injection drug users at risk for HIV. Based on the premise that drug users' social networks were maintained through sharing rituals, this peer-driven approach to disseminate educational information and reduce risk behaviors capitalizes and expands upon the norms that sustain these relationships. Compared with traditional outreach interventions, peer-driven interventions produce greater reductions in HIV risk behaviors and adoption of safer behaviors over time, however, control and intervention groups are not similarly recruited. As peer-recruitment may alter risk networks and individual risk behaviors over time, such comparison studies are unable to isolate the effect of a peer-delivered intervention. This analysis examines whether RDS recruitment (without an intervention) is associated with changes in health-seeking behaviors and network composition over 6 months. New York City drug users (N = 618) were recruited using targeted street outreach (TSO) and RDS (2006–2009). 329 non-injectors (RDS = 237; TSO = 92) completed baseline and 6-month surveys ascertaining demographic, drug use, and network characteristics. Chi-square and t-tests compared RDS- and TSO-recruited participants on changes in HIV testing and drug treatment utilization and in the proportion of drug using, sex, incarcerated and social support networks over the follow-up period. The sample was 66% male, 24% Hispanic, 69% black, 62% homeless, and the median age was 35. At baseline, the median network size was 3, 86% used crack, 70% used cocaine, 40% used heroin, and in the past 6 months 72% were tested for HIV and 46% were enrolled in drug treatment. There were no significant differences by recruitment strategy with respect to changes in health-seeking behaviors or network composition over 6 months. These findings suggest no association between RDS recruitment and changes in network composition or HIV risk, which supports prior findings from prospective HIV behavioral surveillance and intervention studies

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

Intellectual enrichment and genetic modifiers of cognition and brain volume in Huntington's disease

An important step towards the development of treatments for cognitive impairment in ageing and neurodegenerative diseases is to identify genetic and environmental modifiers of cognitive function and understand the mechanism by which they exert an effect. In Huntington’s disease, the most common autosomal dominant dementia, a small number of studies have identified intellectual enrichment, i.e. a cognitively stimulating lifestyle and genetic polymorphisms as potential modifiers of cognitive function. The aim of our study was to further investigate the relationship and interaction between genetic factors and intellectual enrichment on cognitive function and brain atrophy in Huntington’s disease. For this purpose, we analysed data from Track-HD, a multi-centre longitudinal study in Huntington’s disease gene carriers and focused on the role of intellectual enrichment (estimated at baseline) and the genes FAN1, MSH3, BDNF, COMT and MAPT in predicting cognitive decline and brain atrophy. We found that carrying the 3a allele in the MSH3 gene had a positive effect on global cognitive function and brain atrophy in multiple cortical regions, such that 3a allele carriers had a slower rate of cognitive decline and atrophy compared with non-carriers, in agreement with its role in somatic instability. No other genetic predictor had a significant effect on cognitive function and the effect of MSH3 was independent of intellectual enrichment. Intellectual enrichment also had a positive effect on cognitive function; participants with higher intellectual enrichment, i.e. those who were better educated, had higher verbal intelligence and performed an occupation that was intellectually engaging, had better cognitive function overall, in agreement with previous studies in Huntington’s disease and other dementias. We also found that intellectual enrichment interacted with the BDNF gene, such that the positive effect of intellectual enrichment was greater in Met66 allele carriers than non-carriers. A similar relationship was also identified for changes in whole brain and caudate volume; the positive effect of intellectual enrichment was greater for Met66 allele carriers, rather than for non-carriers. In summary, our study provides additional evidence for the beneficial role of intellectual enrichment and carrying the 3a allele in MSH3 in cognitive function in Huntington’s disease and their effect on brain structure

Genome Sequencing of SHH Medulloblastoma Predicts Genotype-Related Response to Smoothened Inhibition

SummarySmoothened (SMO) inhibitors recently entered clinical trials for sonic-hedgehog-driven medulloblastoma (SHH-MB). Clinical response is highly variable. To understand the mechanism(s) of primary resistance and identify pathways cooperating with aberrant SHH signaling, we sequenced and profiled a large cohort of SHH-MBs (n = 133). SHH pathway mutations involved PTCH1 (across all age groups), SUFU (infants, including germline), and SMO (adults). Children >3 years old harbored an excess of downstream MYCN and GLI2 amplifications and frequent TP53 mutations, often in the germline, all of which were rare in infants and adults. Functional assays in different SHH-MB xenograft models demonstrated that SHH-MBs harboring a PTCH1 mutation were responsive to SMO inhibition, whereas tumors harboring an SUFU mutation or MYCN amplification were primarily resistant

A cluster-randomized controlled trial to reduce sedentary behavior and promote physical activity and health of 8-9 year olds: The Transform-Us! Study

Background: Physical activity (PA) is associated with positive cardio-metabolic health and emerging evidence suggests sedentary behavior (SB) may be detrimental to children&rsquo;s health independent of PA. The primary aim of the Transform-Us! study is to determine whether an 18-month, behavioral and environmental intervention in the school and family settings results in higher levels of PA and lower rates of SB among 8-9 year old children compared with usual practice (post-intervention and 12-months follow-up). The secondary aims are to determine the independent and combined effects of PA and SB on children&rsquo;s cardio-metabolic health risk factors; identify the factors that mediate the success of the intervention; and determine whether the intervention is cost-effective.Methods/design: A four-arm cluster-randomized controlled trial (RCT) with a 2 &times; 2 factorial design, with schools as the unit of randomization. Twenty schools will be allocated to one of four intervention groups, sedentary behavior (SB-I), physical activity (PA-I), combined SB and PA (SB+PA-I) or current practice control (C), which will be evaluated among approximately 600 children aged 8-9 years in school year 3 living in Melbourne, Australia. All children in year 3 at intervention schools in 2010 (8-9 years) will receive the intervention over an 18-month period with a maintenance &lsquo;booster&rsquo; delivered in 2012 and children at all schools will be invited to participate in the evaluation assessments. To maximize the sample and to capture new students arriving at intervention and control schools, recruitment will be on-going up to the post-intervention time point. Primary outcomes are time spent sitting and in PA assessed via accelerometers and inclinometers and survey.Discussion: To our knowledge, Transform-Us! is the first RCT to examine the effectiveness of intervention strategies for reducing children&rsquo;s overall sedentary time, promoting PA and optimizing health outcomes. The integration of consistent strategies and messages to children from teachers and parents in both school and family settings is a critical component of this study, and if shown to be effective, may have a significant impact on educational policies as well as on pedagogical and parenting practices.<br /