Hofstra University

About: Hofstra University is a education organization based out in Hempstead, New York, United States. It is known for research contribution in the topics: Population & Medicine. The organization has 6341 authors who have published 11896 publications receiving 268028 citations.

Critical Density for Coverage and Connectivity in Three-Dimensional Wireless Sensor Networks Using Continuum Percolation

Abstract: Although most of the studies on coverage and connectivity in wireless sensor networks (WSNs) considered two-dimensional (2D) settings, such networks can in reality be accurately modeled in a three-dimensional (3D) space. The concepts of continuum percolation theory best fit the problem of connectivity in WSNs to find out whether the network provides long-distance multihop communication. In this paper, we focus on percolation in coverage and connectivity in 3D WSNs. We say that the network exhibits a coverage percolation (respectively, connectivity percolation) when a giant covered region (respectively, giant connected component) almost surely spans the entire network for the first time. Because of the dependency between coverage and connectivity, the problem is not only a continuum percolation problem but also an integrated continuum percolation problem. Thus, we propose an integrated-concentric-sphere model to address coverage and connectivity in 3D WSNs in an integrated way. First, we compute the critical density lambdaC con above which coverage percolation in 3D WSNs will almost surely occur. Second, we compute the critical density lambdac con above which connectivity percolation in 3D WSNs will almost surely occur. Third, we compute the critical density lambdac cov-con above which both coverage and connectivity percolation in 3D WSNs will almost surely occur. For each of these three problems, we also compute their corresponding critical network degree. Our results can be helpful in the design of energy-efficient topology control protocols for 3D WSNs in terms of coverage and connectivity.

Distribution of Human Papillomavirus Genotypes among HIV-Positive and HIV-Negative Women in Cape Town, South Africa.

Abstract: Objective: HIV-positive women are known to be at high risk of Human Papillomavirus (HPV) infection and its associated cervical pathology. Here we describe the prevalence and distribution of HPV genotypes among HIV-positive and negative women in South Africa, with and without cervical intraepithelial neoplasia (CIN). Methods: We report data on 1,371 HIV-positive women and 8,050 HIV-negative women, aged 17-65 years, recruited into three sequential studies in Cape Town, South Africa, conducted among women who had no history of cervical cancer screening recruited from the general population. All women were tested for HIV. Cervical samples were tested for high risk HPV DNA (Hybrid Capture 2) with positive samples tested to determine the specific genotype (Line Blot). CIN status was determined based on colposcopy and biopsy. Results: The HPV prevalence was higher among HIV-positive women (52.4%) than among HIV-negative women (20.8%) overall and in all age groups. Younger women, aged 17-19 years, had the highest HPV prevalence regardless of HIV status. HIV-positive women were more likely to have CIN 2 or 3 than HIV-negative women. HPV 16, 35, and 58 were the most common high-risk HPV types with no major differences in the type distribution by HIV status. HPV 18 was more common in older HIV-positive women (40-65 years) with no or low grade disease, but less common in younger women (17-29 years) with CIN 2 or 3, compared to HIV-negative counterparts (pConclusion: HIV-positive women were more likely to have high risk HPV than HIV-negative women but among those with HPV, the distribution of HPV types was similar by HIV status. Screening strategies incorporating HPV genotyping and vaccination should be effective in preventing cervical cancer in both HIV-positive and negative women living in sub-Saharan Africa.

Easing the Transition of HIV-Infected Adolescents to Adult Care

Abstract: The past two decades have witnessed dramatic reductions in HIV-related morbidity and mortality following the introduction of combination antiretroviral therapy (cART) for infants and children. Improved therapeutic outcomes have changed the face of the HIV epidemic and with it the needs of patients and families. Consequently, many perinatally- and behaviorally-infected adolescents are now transitioning to adult care. What follows is a brief review and commentary concerning original research, reviews, and clinical guidelines describing challenges and best practices in facilitating care transitions for HIV-infected youth to adult care. Over 25,000 HIV-infected US youth aged 13–24 years will require transition to adult care within the next decade. Transition planning must address issues of cognitive development and mental health, medication adherence, sexuality, reproductive, and gender identity, socioeconomic and health insurance status, stigma and disclosure, disrupted relationships with pediatric ...

Online business education in the twenty-first century: an analysis of potential target markets

Abstract: The future of online business education seems quite bright. Three‐fifths of the 1,700 US institutions of higher learning that are engaged in distance education – 55 percent of which offer credit‐bearing business courses – already use some form of Internet‐based technology. Nonetheless, there have been no large‐scale studies of potential online business students in terms of their traits and desires. In this article, the background of distance education is presented. Then, the results of a major survey, involving NPD’s Online Research Panel, are discussed. In all, 2,651 adults participated in the survey, 1,945 of whom indicated some interest in online business education. Eight propositions are tested, relating to demographics, courses versus programs, reasons for enrolling or not enrolling, desired features, customer service expectations, tuition, prestige and value, and institutional attributes.