Sexual risk reduction among Zambian couples

Zambia has over 1 million HIV infections nationwide and an urban prevalence rate of 23%. This study compared the impact of maleinvolvement in multiple and single session risk reduction interventions among inconsistent condom users in Zambia and the role ofserostatus among HIV-seropositive and serodiscordant couples. Couples (N=392) were randomised into intervention arms. Amonginconsistent condom users at baseline (N=83), condom use increased in both conditions and this increase was maintained over a 12-month period. At 12 months, seronegative men in the multiple session condition increased sexual barrier (male and female condoms)use in comparison with those in the single session condition (F=16.13, p=0.001) while seropositive individuals increased sexualbarrier use regardless of condition. Results illustrate the importance of both single and multiple session risk reduction counsellingamong seronegative men in serodiscordant couples in Zambia, and highlight the differing perception of risk between seropositiveand serodiscordant persons.Keywords: HIV, men, women, Africa, high-risk behaviour, behavioural intervention

The interacting roles of climate, soils, and plant production on soil microbial communities at a continental scale

Soil microbial communities control critical ecosystem processes such as decomposition, nutrient cycling, and soil organic matter formation. Continental scale patterns in the composition and functioning of microbial communities are related to climatic, biotic, and edaphic factors such as temperature and precipitation, plant community composition, and soil carbon, nitrogen, and pH. Although these relationships have been well explored individually, the examination of the factors that may act directly on microbial communities vs. those that may act indirectly through other ecosystem properties has not been well developed. To further such understanding, we utilized structural equation modeling (SEM) to evaluate a set of hypotheses about the direct and indirect effects of climatic, biotic, and edaphic variables on microbial communities across the continental United States. The primary goals of this work were to test our current understanding of the interactions among climate, soils, and plants in affecting microbial community composition, and to examine whether variation in the composition of the microbial community affects potential rates of soil enzymatic activities. A model of interacting factors created through SEM shows several expected patterns. Distal factors such as climate had indirect effects on microbial communities by influencing plant productivity, soil mineralogy, and soil pH, but factors related to soil organic matter chemistry had the most direct influence on community composition. We observed that both plant productivity and soil mineral composition were important indirect influences on community composition at the continental scale, both interacting to affect organic matter content and microbial biomass and ultimately community composition. Although soil hydrolytic enzymes were related to the moisture regime and soil carbon, oxidative enzymes were also affected by community composition, reflected in the abundance of soil fungi. These results highlight that soil microbial communities can be modeled within the context of multiple interacting ecosystem properties acting both directly and indirectly on their composition and function, and this provides a rich and informative context with which to examine communities. This work also highlights that variation in climate, microbial biomass, and microbial community composition can affect maximum rates of soil enzyme activities, potentially influencing rates of decomposition and nutrient mineralization in soils

Carbon Fluxes and Microbial Activities From Boreal Peatlands Experiencing Permafrost Thaw

Permafrost thaw in northern ecosystems may cause large quantities of carbon (C) to move from soil to atmospheric pools. Because soil microbial communities play a critical role in regulating C fluxes from soils, we examined microbial activity and greenhouse gas production soon after permafrost thaw and ground collapse (into collapse‐scar bogs), relative to the permafrost plateau or older thaw features. Using multiple field and laboratory‐based assays at a field site in interior Alaska, we show that the youngest collapse‐scar bog had the highest CH4 production potential from soil incubations, and, based upon temporal changes in porewater concentrations and 13C‐CH4 and 13C‐CO2, had greater summer in situ rates of respiration, methanogenesis, and surface CH4 oxidation. These patterns could be explained by greater C and N availability in the young bog, while alternative terminal electron accepting processes did not play a significant role. Field diffusive CH4 fluxes from the young bog were 4.1 times greater in the shoulder season and 1.7–7.2 times greater in winter relative to older bogs, but not during summer. Greater relative CH4 flux rates in the shoulder season and winter could be due to reduced CH4 oxidation relative to summer, magnifying the importance of differences in production. Both the permafrost plateau and collapse‐scar bogs were sources of C to the atmosphere due in large part to winter C fluxes. In collapse scar bogs, winter is a critical period when differences in thermokarst age translates to differences in surface fluxes. Plain Language Summary Permafrost thaw is occurring in Alaska which may result in a positive feedback to climate warming, due to the release of greenhouse gases such as CO2 and CH4 from soils. Here we examined greenhouse gas production along a gradient of “time since thaw,” hypothesizing that fluxes and microbial activities would be highest soon after thaw, and then decline. We observed highest rates of microbial activities, particularly methanogenesis, soon after thaw, coinciding with less decomposed organic matter and higher concentrations of dissolved carbon and nitrogen in soil, possibly of permafrost origin. However, field fluxes were higher in the young thaw site, compared to the older sites, in winter and not summer, a phenomenon that is currently not well understood

A Nomadic Testbed for Teaching Computer Architecture

A nomadic laboratory or testbed, based on Raspberry Pi 3 computers and Arduino microcontrollers, has been developed in order to teach subjects related to computer architecture. The testbed can be transported to the classroom. Students can access it through the available network, which can be a wireless LAN, wired LAN o a custom network. The student can access without constraints to the platforms, therefore there are a wide range of possible experiments. This laboratory was used during 2017 for practical works in the course Introduction to Technology, and during 2018 in the course Computers Architecture at Universidad Nacional of Cuyo. Some of the experiments that are been carried out by students are: to explore and analyse the architecture of the computers through Linux commands, write and run programs on different programing languages, input and output operations through memory mapped addressing and isolated addressing, write interrupt service routines in order to service interrupts, multithreading programing, explore memory maps, CPU features, etc. This paper describes the testbed architecture, experiments performed by students in the mentioned subjects, present the students feedback, and describes the possible methods in order to integrate it to a remote laboratory.XVII Workshop Tecnología Informática Aplicada en Educación (WTIAE)Red de Universidades con Carreras en Informática (RedUNCI

Functional Impairment of Central Memory CD4 T Cells Is a Potential Early Prognostic Marker for Changing Viral Load in SHIV-Infected Rhesus Macaques

In HIV infection there is a paucity of literature about the degree of immune dysfunction to potentially correlate and/or predict disease progression relative to CD4+ T cells count or viral load. We assessed functional characteristics of memory T cells subsets as potential prognostic markers for changing viral loads and/or disease progression using the SHIV-infected rhesus macaque model. Relative to long-term non-progressors with low/undetectable viral loads, those with chronic plasma viremia, but clinically healthy, exhibited significantly lower numbers and functional impairment of CD4+ T cells, but not CD8+ T cells, in terms of IL-2 production by central memory subset in response to PMA and ionomycine (PMA+I) stimulation. Highly viremic animals showed impaired cytokine-production by all T cells subsets. These results suggest that functional impairment of CD4+ T cells in general, and of central memory subset in particular, may be a potential indicator/predictor of chronic infection with immune dysfunction, which could be assayed relatively easily using non-specific PMA+I stimulation

The psychology of dynamic balance and peak performance in sport: correction theory

This article introduces a new approach to understanding peak performance and dysfunctional performance in sport, correction theory. Correction theory, based within a control theory and dynamical systems perspective, assumes that dynamic balance (a state in which a robust complex system will self-correct in response to imbalance) underwrites individual functioning. The central thesis presented in this article is that an interdependent relationship exists between peak performance and dysfunctional performance in sport. Peak performance is, in part, a (corrective) response to dysfunctional performance and vice versa. An overview of correction theory is presented, based on two propositions relating to balance. Implications of correction theory for understanding sporting performance are briefly considered.N/

Nonlinear Dynamics and Interpersonal Correlates of Verbal Turn-Taking Patterns in a Group Therapy Session

Interpersonal processes and dynamics are ubiquitous topics in psychotherapy, yet they are difficult to study and are theoretically fragmented across therapeutic subdisciplines. The current study tests an integrative model of interpersonal dynamics in small groups using nonlinear dynamical systems theory. The conversation of one group therapy session (with six adolescent sex offenders) is analyzed using orbital decomposition, which allows for the identification of patterns in categorical time series data. The results show evidence of selforganizing social patterns, based on formal measures of turbulence (Lyapunov dimension), information novelty (Shannon\u27s entropy), and complexity (fractal dimension). The degree of patterning in turn taking is significantly correlated with measurements of control, closeness, and conflict among group members. Clinical implications and directions for future research are discussed

Humoral and Cellular CMV Responses in Healthy Donors; Identification of a Frequent Population of CMV-Specific, CD4+ T Cells in Seronegative Donors

CMV status is an important risk factor in immune compromised patients. In hematopoeitic cell transplantations (HCT), both donor and recipient are tested routinely for CMV status by serological assays; however, one might argue that it might also be of relevance to examine CMV status by cellular (i.e., T lymphocyte) assays. Here, we have analyzed the CMV status of 100 healthy blood bank donors using both serology and cellular assays. About half (56%) were found to be CMV seropositive, and they all mounted strong CD8+ and/or moderate CD4+ T cell responses ex vivo against the immunodominant CMV protein, pp65. Of the 44 seronegative donors, only five (11%) mounted ex vivo T cell responses; surprisingly, 33 (75%) mounted strong CD4+ T cell responses after a brief in vitro peptide stimulation culture. This may have significant implications for the analysis and selection of HCT donors

Is U.S. health care an appropriate system? A strategic perspective from systems science

<p>Abstract</p> <p>Context</p> <p>Systems science provides organizational principles supported by biologic findings that can be applied to any organization; any incongruence indicates an incomplete or an already failing system. U.S. health care is commonly referred to as a system that consumes an ever- increasing percentage of the gross domestic product and delivers seemingly diminishing value.</p> <p>Objective</p> <p>To perform a comparative study of U.S. health care with the principles of systems science and, if feasible, propose solutions.</p> <p>Design</p> <p>General systems theory provides the theoretical foundation for this observational research.</p> <p>Main Outcome Measures</p> <p>A degree of compliance of U.S. health care with systems principles and its space-time functional location within the dynamic systems model.</p> <p>Results of comparative analysis</p> <p>U.S. health care is an incomplete system further threatened by the fact that it functions in the zone of chaos within the dynamic systems model.</p> <p>Conclusion</p> <p>Complying with systems science principles and the congruence of pertinent cycles, U.S. health care would likely dramatically improve its value creation for all of society as well as its resiliency and long-term sustainability.</p> <p>Immediate corrective steps could be taken: Prioritize and incentivize <it>health </it>over <it>care</it>; restore fiscal soundness by combining health and life insurance for the benefit of the insured and the payer; rebalance horizontal/providers and vertical/government hierarchies.</p