HIV and Concurrent Sexual Partnerships: Modelling the Role of Coital Dilution

Background: The concurrency hypothesis asserts that high prevalence of overlapping sexual partnerships explains extraordinarily high HIV levels in sub-Saharan Africa. Earlier simulation models show that the network effect of concurrency can increase HIV incidence, but those models do not account for the coital dilution effect (nonprimary partnerships have lower coital frequency than primary partnerships). Methods: We modify the model of Eaton et al (AIDS and Behavior, September 2010) to incorporate coital dilution by assigning lower coital frequencies to non-primary partnerships. We parameterize coital dilution based on the empirical work of Morris et al (PLoS ONE, December 2010) and others. Following Eaton et al, we simulate the daily transmission of HIV over 250 years for 10 levels of concurrency. Results: At every level of concurrency, our focal coital-dilution simulation produces epidemic extinction. Our sensitivity analysis shows that this result is quite robust; even modestly lower coital frequencies in non-primary partnerships lead to epidemic extinction. Conclusions: In order to contribute usefully to the investigation of HIV prevalence, simulation models of concurrent partnering and HIV epidemics must incorporate realistic degrees of coital dilution. Doing so dramatically reduces the role that concurrency can play in accelerating the spread of HIV and suggests that concurrency cannot be an important driver of HIV epidemics in sub-Saharan Africa. Alternative explanations for HIV epidemics in sub- Saharan Africa are needed

Classifying The Questions Of Small Business Owners: A Top-Down and Bottom-Up Approach

A classification scheme of business information needs was developed through question analysis of a set of business requests posed by small business entrepreneurs in the state of Maryland. Existing business classification schemes were examined for use in the project and while an existing scheme could be used for subject/industry analysis, no classification scheme was found to be adequate for the information requirements. This classification of business requests can be used to enhance communication between intermediaries and their clients, provide an understanding of user needs, assist in the develop of search strategies, and provide a basis for correlating information requirements with industry, age of industry and purpose of request

Rural Hospital Nursing Skill Mix and Work Environment Associated with Frequency of Adverse Events.

Introduction: Though rural hospitals serve about one fifth of the United States (U.S.), few studies have investigated relationships among nursing resources and rural hospital adverse events. Objectives: The purpose was to determine relationships among nursing skill mix (proportion of Registered Nurses (RNs) to all nursing staff), the work environment and adverse events (medication errors, patient falls with injury, pressure ulcers, and urinary tract infections) in rural hospitals. Methods: Using a cross-sectional design, nurse survey data from a large study examining nurse organizational factors, patient safety, and quality from four U.S. states were linked to the 2006 American Hospital Association data. The work environment was measured using the Practice Environment Scale of the Nursing Work Index (PES-NWI). Nurses reported adverse event frequency. Data analyses were descriptive and inferential. Results: On average, 72% of nursing staff were RNs (range = 45% to 100%). Adverse event frequency ranged from 0% to 67%, across 76 hospitals. In regression models, a 10-point increase in the proportion of RNs among all nursing staff and a one standard deviation increase in the PES-NWI score were significantly associated with decreased odds of frequent adverse events. Conclusion: Rural hospitals that increase the nursing skill mix and improve the work environment may achieve reduced adverse event frequency

Parental safety concerns and active school commute: correlates across multiple domains in the home-to-school journey

Abiodun O. Oluyomi, Eileen Nehme, and Deanna M. Hoelscher are with The Michael and Susan Dell Center for Healthy Living, UT School of Public Health, Austin Regional Campus, The University of Texas Health Science Center at Houston, Austin, TX USA -- Chanam Lee is with the Department of Landscape Architecture and Urban Planning, College of Architecture, Texas AM University, College Station, TX USA -- Diane Dowdy and Marci G. Ory are with the School of Rural Public Health, Texas AM HeaBackground: Empirical evidence of the relationship between safety concerns and walking to school (WTS) is growing. However, current research offers limited understanding of the multiple domains of parental safety concerns and the specific mechanisms through which parents articulate safety concerns about WTS. A more detailed understanding is needed to inform environmental and policy interventions. This study examined the relationships between both traffic safety and personal safety concerns and WTS in the U.S. Methods: This cross-sectional analysis examined data from the Texas Childhood Obesity Prevention Policy Evaluation (T-COPPE) project, an evaluation of state-wide obesity prevention policy interventions. All study data were from the survey (n = 830) of parents with 4th grade students attending 81 elementary schools across Texas, and living within two miles from their children's schools. Traffic safety and personal safety concerns were captured for the home neighborhood, en-route to school, and school environments. Binary logistic regression analysis was used to assess the odds of WTS controlling for significant covariates. Results: Overall, 18% of parents reported that their child walked to school on most days of the week. For traffic safety, students were more likely to walk to school if their parent reported favorable perceptions about the following items in the home neighborhood environment: higher sidewalk availability, well maintained sidewalks and safe road crossings. For the route to school, the odds of WTS were higher for those who reported "no problem" with each one of the following: traffic speed, amount of traffic, sidewalks/pathways, intersection/crossing safety, and crossing guards, when compared to those that reported "always a problem". For personal safety in the en-route to school environment, the odds of WTS were lower when parents reported concerns about: stray or dangerous animals and availability of others with whom to walk. Conclusions: Findings offered insights into the specific issues that drive safety concerns for elementary school children’s WTS behaviors. The observed associations between more favorable perceptions of safety and WTS provide further justification for practical intervention strategies to reduce WTS barriers that can potentially bring long-term physical activity and health benefits to school-aged children.Public [email protected]

Increased insertion number leads to increased sperm transfer and fertilization success in a nursery web spider

Across animals, a male\u27s fitness is largely dictated by his ability to fertilize eggs; and there exists a plethora of male adaptations associated with increasing fertilization success. In the nursery web spider, Pisaurina mira, males restrain females prior to and during copulation by wrapping them with silk. Previous research demonstrates that copulatory silk wrapping reduces a male\u27s chance of being sexually cannibalized and increases the number of sperm transfer opportunities (termed insertions) that a male can achieve within a mating. While avoiding cannibalism provides an obvious survival benefit to males, the impact of insertion number on male fitness remains unknown. This study tested the hypothesis that increased insertion number realized through copulatory silk wrapping increases (1) the quantity of sperm transferred and (2) fertilization success. To accomplish this, we directly quantified the amount of sperm in male pedipalps (i.e. the male sperm storage organ) before mating and after obtaining one or two insertions. We also, indirectly quantified fertilization success by measuring the number of hatched offspring when males were capable of achieving one versus two insertions within a mating. In support of our hypotheses, we found that males transfer roughly twice the amount of sperm when achieving two insertions compared to one. We additionally found that the amount of sperm transferred is negatively related to female size. In terms of offspring number, females obtaining two insertions had more offspring compared to females obtaining only one insertion. These results show that males achieve a fertilization benefit from increased insertion number, which is obtained through the male behavior of copulatory silk wrapping

History to Data: Converting Topographic Maps into Digital Elevation Models

Studying past landscapes existing before the modern era (pre-1945) carries great difficulty. Historical maps can offer insight to researchers, but the two-dimensional cartographic features on these maps remain largely inaccessible for geospatial analyses. This study investigates the idea of unlocking the data within historical maps to be utilized by Geographic Information Systems (GIS). To realize this goal, the cartographic features must be extracted and converted into digital vector (line) and raster (grid) data. For the purposes of this study, we focus on the extraction of elevation contour lines in United States Geological Survey (USGS) historical topographic maps. These lines are converted into Digital Elevation Models (DEMs), thus creating historically accurate digital landscapes. To ensure a high-quality result, the topographically derived DEMs (TOPO-DEMs) are compared to modern satellite-derived DEMs. The implications of this study can be directly applied to historical, archeological, and environmental research

Searching for Unmarked Graves at Historic Carter Mansion, Elizabethton, TN

Carter Mansion is a well-known historic site in Tennessee. It is estimated to have been built in the 1770s and is believed to be the oldest frame house, a house with a wooden skeleton for the base, in the state. This house was built by John and Landon Carter, father, and son respectively, who were well known influential leaders of the Watauga Settlement in the late 18th century. Prior to their arrival, the area was home to Native Americans. The aim of this research was to perform a geophysical survey of a previously unresearched area of the site, providing guidance for future development of the property. A ground penetrating radar (GPR) survey was conducted with a GSSI SIR4000 with 400 MHz antennas. Previous research was able to identify both historic and prehistoric graves in other areas of the property. This project extends this knowledge and aims to determine if there are graves associated with the headstones of the Carters on the eastern margin of the property, thus enriching the history and prehistory of the site without disturbing the grounds