Changes in Sexual Risk Perception and Risk Taking Among Urban African American Adolescents

Background: Adolescents and young adults aged 15 to 24 acquire nearly half of all new STDs in the United States, yet they represent only 25% of the sexually active population. Young men and women in this age group have the highest rates of chlamydia, gonorrhea, and syphilis, especially in the African American population. Adolescent risk factors include having a history of pregnancy or STDs, being arrested or incarcerated, substance abuse, early sexual debut and having 4 or more lifetime sexual partners. Protective behaviors such as parental involvement, school enrollment, and consistent condom use have been associated with decreased incidence of STDs. The purpose of this study is to observe changes in adolescent behaviors and experiences that are known risk factors for acquiring sexually transmitted diseases. The aim is to identify the time at which STD prevention interventions may be administered most effectively. In addition, the study aims to identify relevant themes and content that may be useful in creating interventions targeted to different age groups and genders. Methods: This study utilizes primary data collected between 1999 and 2003 by Dr. Rothenberg and colleagues for a community-based network study of low-income African American adolescents living in a working class neighborhood in Southwest Atlanta. Two descriptive analyses were conducted: a period analysis in which all participants ages 15 to 18 who completed any or all of three interviews were included; and a cohort analysis, which included only participants who completed three interviews and who were 15, 16, 17 or 18 years of age at the time of the first interview. Univariate analysis was used to describe each variable and the resulting frequencies and percentages were reported. Results: In both period and cohort analyses, higher proportions of older adolescents (ages 17 and 18) reported engaging in risky behaviors including drinking alcohol, using marijuana, having sex and having multiple sexual partners, compared to younger adolescents (ages 15 and 16). Males reported higher proportions of engaging in risky behaviors than females, but also higher proportions of condom use. The proportion of participants diagnosed with one or more STDs decreased at each interview. In the cohort analysis, the proportion of participants who perceived their STD risk as “medium” or “high” increased over time. Conclusions: The findings suggest that as adolescents mature they engage in a greater variety of risky behaviors known to have a positive association to STD diagnosis. Period analyses, which have usually been done to study the sexual behaviors of adolescents, may give aberrant results that are clearer when the population is studied as a cohort. Future studies are needed to more precisely identify the period during which adolescents experience rapid changes in their risk behaviors

Polymorphism of the Fractalkine Receptor CX3CR1 and Systemic Sclerosis-associated Pulmonary Arterial Hypertension

Fractalkine (FKN) and its receptor CX3CR1 are critical mediators in the vascular and tissue damage of several chronic diseases, including systemic sclerosis (SSc) and pulmonary arterial hypertension (PAH). Interestingly, the V249I and T280M genetic polymorphisms influence CX3CR1 expression and function. We investigated whether these polymorphisms are associated with PAH secondary to SSc. CX3CR1 genotypes were analyzed by PCR and sequencing in 76 patients with limited SSc and 204 healthy controls. PAH was defined by colorDoppler echocardiography. Homozygosity for 249II as well as the combined presence of 249II and 280MM were significantly more frequent in patients with SSc compared to controls (17 vs 6%, p = 0.0034 and 5 vs 1%, p = 0.0027, respectively). The 249I and 280M alleles were associated with PAH (odd ratio [OR] 2.2, 95% confidence interval [CI] 1.01-4.75, p = 0.028 and OR 7.37, 95%CI: 2.45-24.60, p = 0.0001, respectively). In conclusion, the increased frequencies of 249I and 280M CX3CR1 alleles in a subgroup of patients with SSc-associated PAH suggest a role for the fractalkine system in the pathogenesis of this condition. Further, the 249I allele might be associated with susceptibility to SSc

Towards a science of climate and energy choices

The linked problems of energy sustainability and climate change are among the most complex and daunting facing humanity at the start of the twenty-first century. This joint Nature Energy and Nature Climate Change Collection illustrates how understanding and addressing these problems will require an integrated science of coupled human and natural systems; including technological systems, but also extending well beyond the domain of engineering or even economics. It demonstrates the value of replacing the stylized assumptions about human behaviour that are common in policy analysis, with ones based on data-driven science. We draw from and engage articles in the Collection to identify key contributions to understanding non-technological factors connecting economic activity and greenhouse gas emissions, describe a multi-dimensional space of human action on climate and energy issues, and illustrate key themes, dimensions and contributions towards fundamental understanding and informed decision making

Spinal afferent neurons projecting to the rat lung and pleura express acid sensitive channels

BACKGROUND: The acid sensitive ion channels TRPV1 (transient receptor potential vanilloid receptor-1) and ASIC3 (acid sensing ion channel-3) respond to tissue acidification in the range that occurs during painful conditions such as inflammation and ischemia. Here, we investigated to which extent they are expressed by rat dorsal root ganglion neurons projecting to lung and pleura, respectively. METHODS: The tracer DiI was either injected into the left lung or applied to the costal pleura. Retrogradely labelled dorsal root ganglion neurons were subjected to triple-labelling immunohistochemistry using antisera against TRPV1, ASIC3 and neurofilament 68 (marker for myelinated neurons), and their soma diameter was measured. RESULTS: Whereas 22% of pulmonary spinal afferents contained neither channel-immunoreactivity, at least one is expressed by 97% of pleural afferents. TRPV1(+)/ASIC3(- )neurons with probably slow conduction velocity (small soma, neurofilament 68-negative) were significantly more frequent among pleural (35%) than pulmonary afferents (20%). TRPV1(+)/ASIC3(+ )neurons amounted to 14 and 10% respectively. TRPV1(-)/ASIC3(+ )neurons made up between 44% (lung) and 48% (pleura) of neurons, and half of them presumably conducted in the A-fibre range (larger soma, neurofilament 68-positive). CONCLUSION: Rat pleural and pulmonary spinal afferents express at least two different acid-sensitive channels that make them suitable to monitor tissue acidification. Patterns of co-expression and structural markers define neuronal subgroups that can be inferred to subserve different functions and may initiate specific reflex responses. The higher prevalence of TRPV1(+)/ASIC3(- )neurons among pleural afferents probably reflects the high sensitivity of the parietal pleura to painful stimuli

Overconfidence in Labor Markets

This chapter reviews how worker overconfidence affects labor markets. Evidence from psychology and economics shows that in many situations, most people tend to overestimate their absolute skills, overplace themselves relative to others, and overestimate the precision of their knowledge. The chapter starts by reviewing evidence for overconfidence and for how overconfidence affects economic choices. Next, it reviews economic explanations for overconfidence. After that, it discusses research on the impact of worker overconfidence on labor markets where wages are determined by bargaining between workers and firms. Here, three key questions are addressed. First, how does worker overconfidence affect effort provision for a fixed compensation scheme? Second, how should firms design compensation schemes when workers are overconfident? In particular, will a compensation scheme offered to an overconfident worker have higher-or lower-powered incentives than that offered to a worker with accurate self-perception? Third, can worker overconfidence lead to a Pareto improvement? The chapter continues by reviewing research on the impact of worker overconfidence on labor markets where workers can move between firms and where neither firms nor workers have discretion over wage setting. The chapter concludes with a summary of its main findings and a discussion of avenues for future research

Biomedical colonialism or local autonomy?: local healers in the fight against tuberculosis

Analiza el papel de los agentes médicos autóctonos y sus conocimientos en las campañas antituberculosas contemporáneas en el África subsahariana. Sitúa la medicina contemporánea, llevada a cabo en África en la herencia cultural de la medicina colonial, para comprender el marco histórico en el que se desarrollaron, a partir de los años setenta del siglo XX, las estrategias de la Organización Mundial de la Salud de promoción y desarrollo de las medicinas 'tradicionales'. En los proyectos sanitarios analizados, se evalúan las prácticas médicas locales y se entrenan a los agentes autóctonos para integrarlos en actividades estrictamente biomédicas: identificación de síntomas, remisión a hospitales o supervisión de tratamientos farmacológicos.The article explores the role played by indigenous medical agents, and their knowledge, within contemporary tuberculosis campaigns in sub-Saharan Africa. To understand the historical framework within which the World Health Organization devised its strategies to promote and develop traditional medicine as of the 1970s, the article contextualizes contemporary medicine as a cultural legacy of colonial medicine. Under the public healthcare projects analyzed in the article, local medical practices were assessed and indigenous agents trained so they could take part in strictly biomedical activities, like symptom identification, referrals to hospitals, or supervision of drug treatments.Trabajo realizado para la obtención del Diploma de Estudios Avanzados (DEA) en el programa de doctorado Salud: Antropología e Historia, bajo la dirección de la profesora Rosa María Medina Doménech

Theory, practice and policy: An inquiry into the uptake of HCI practices in the software industry of a developing country

With almost four decades of existence as a community, human–computer interaction (HCI) practice has yet to diffuse into a large range of software industries globally. A review of existing literature suggests that the diffusion of HCI practices in software organizations lacks theoretical guidance. Although many studies have tried to facilitate HCI uptake by the software industry, there are scarce studies that consider HCI practices as innovations that software organizations could or should adopt. Furthermore, there appears to be a lack of structure in the facilitation of HCI methodological development within the specialized emerging regions field such as Sub-Saharan Africa. In order to address this gap, an exploratory investigation regarding the state of uptake of HCI practices in Nigeria is conducted. The aim of this article is to improve our understanding regarding the state of HCI uptake in developing countries and the challenges prevailing. The findings show that HCI practice still remains within its infancy stage in most software companies. Universities are also lacking the required knowledge transfer of HCI to the students, and in effect themselves contributing to the lack of HCI skills in industry. Furthermore, government policies are in need of refinement and end-users’ involvement in software development is not prioritized