College Students\u27 Knowledge Of Human Immunodeficiency Virus And Willingness To Participate In Screening

An estimated 1.2 million adults and adolescents are living with human immunodeficiency virus (HIV) in the United States and approximately 50,000 are newly infected each year. The Centers for Disease Control and Prevention (CDC) estimates that 44% of HIV- infected youth ages 18-24 are unaware of their HIV status. HIV destroys CD4 cells and leads to a severely weakened immune system, which increases the risk for infection and other infection-related cancers. If HIV is left untreated, the disease will eventually progress to acquired immunodeficiency syndrome (AIDS). HIV continues to be a concern in public health, yet the public perception about the severity of the HIV epidemic has declined in recent years. Although research suggests that college students are highly educated on modes of transmission for HIV, they continue to practice risky sexual behaviors that will increase their risk of HIV transmission. The researchers in this study utilized a descriptive, non-experimental, quantitative design to determine college students\u27 knowledge regarding HIV and their willingness to be tested for HIV. The researchers used a modified version of the HIV-KQ-18 questionnaire. This questionnaire was passed out to students at the Campus Health Center. The questionnaire contained fivedemographic questions regarding age, sex, gender, and race. In addition, the questionnaire contained 18 knowledge-based questions. Lastly, two questions were included regarding the history of HIV testing and willingness to test for HIV. The population surveyed were college students over the age of 18 who attended the Campus Health Center in the southeastern United States. A convenience sample was utilized to obtain a sample of 38 students. Data analysis revealed that college age students were not knowledgeable of HIV. The average score on the knowledge-based questions was 71.49%, which was below the benchmark of 72.2% set by the researchers. When evaluating self-reported practices of the sample population, only 28.9% percent reported having been tested for HIV in the past, but 92.1 % percent reported being willing to be tested for HIV. Findings revealed a great need for further education regarding HIV knowledge and HIV testing among college students in the southeastern United States

Enhancement of Rydberg-mediated single-photon nonlinearities by electrically tuned Förster resonances

We demonstrate experimentally that Stark-tuned Förster resonances can be used to substantially increase the interaction between individual photons mediated by Rydberg interaction inside an optical medium. This technique is employed to boost the gain of a Rydberg-mediated single-photon transistor and to enhance the non-destructive detection of single Rydberg atoms. Furthermore, our all-optical detection scheme enables high-resolution spectroscopy of two-state Förster resonances, revealing the fine structure splitting of high-n Rydberg states and the non-degeneracy of Rydberg Zeeman substates in finite fields. We show that the ∣50S1/2,48S1/2⟩↔∣49P1/2,48P1/2⟩ pair state resonance in 87Rb enables simultaneously a transistor gain G>100 and all-optical detection fidelity of single Rydberg atoms F>0.8. We demonstrate for the first time the coherent operation of the Rydberg transistor with G>2 by reading out the gate photon after scattering source photons. Comparison of the observed readout efficiency to a theoretical model for the projection of the stored spin wave yields excellent agreement and thus successfully identifies the main decoherence mechanism of the Rydberg transistor

Construction and application for QTL analysis of a Restriction Site Associated DNA (RAD) linkage map in barley

<p>Abstract</p> <p>Background</p> <p>Linkage maps are an integral resource for dissection of complex genetic traits in plant and animal species. Canonical map construction follows a well-established workflow: an initial discovery phase where genetic markers are mined from a small pool of individuals, followed by genotyping of selected mapping populations using sets of marker panels. A newly developed sequence-based marker technology, Restriction site Associated DNA (RAD), enables synchronous single nucleotide polymorphism (SNP) marker discovery and genotyping using massively parallel sequencing. The objective of this research was to assess the utility of RAD markers for linkage map construction, employing barley as a model system. Using the published high density EST-based SNP map in the Oregon Wolfe Barley (OWB) mapping population as a reference, we created a RAD map using a limited set of prior markers to establish linakge group identity, integrated the RAD and prior data, and used both maps for detection of quantitative trait loci (QTL).</p> <p>Results</p> <p>Using the RAD protocol in tandem with the Illumina sequence by synthesis platform, a total of 530 SNP markers were identified from initial scans of the OWB parental inbred lines - the "dominant" and "recessive" marker stocks - and scored in a 93 member doubled haploid (DH) mapping population. RAD sequence data from the structured population was converted into allele genotypes from which a genetic map was constructed. The assembled RAD-only map consists of 445 markers with an average interval length of 5 cM, while an integrated map includes 463 RAD loci and 2383 prior markers. Sequenced RAD markers are distributed across all seven chromosomes, with polymorphic loci emanating from both coding and noncoding regions in the <it>Hordeum </it>genome. Total map lengths are comparable and the order of common markers is identical in both maps. The same large-effect QTL for reproductive fitness traits were detected with both maps and the majority of these QTL were coincident with a dwarfing gene (<it>ZEO) </it>and the <it>VRS1 </it>gene, which determines the two-row and six-row germplasm groups of barley.</p> <p>Conclusions</p> <p>We demonstrate how sequenced RAD markers can be leveraged to produce high quality linkage maps for detection of single gene loci and QTLs. By combining SNP discovery and genotyping into parallel sequencing events, RAD markers should be a useful molecular breeding tool for a range of crop species. Expected improvements in cost and throughput of second and third-generation sequencing technologies will enable more powerful applications of the sequenced RAD marker system, including improvements in <it>de novo </it>genome assembly, development of ultra-high density genetic maps and association mapping.</p

Mathematics teacher change in a collaborative environment: to what extent and how

This article reports on a study into how collaborative contexts influence the professional development of an early-career primary teacher, Julia. We describe the process of change by which Julia manages to make her planning to teach mathematics more flexible so as to adapt to student difficulties, and we analyse the role that joint reflection plays in promoting this change. In order to understand the how of this influence, we carried out an analysis of the interactions within the group from Julia’s point of view, following a dialogical approach to discourse. We believe that it is in and through the interactions that Julia constructs her interpretation of the opinions, critiques and suggestions expressed. This interpretation conditions the extent of her involvement and moulds the influence of the context on her professional development. The presence of skilled collaborators (Day, 1993) proved decisive in promoting this development

Mysid crustaceans as standard models for the screening and testing of endocrine-disrupting chemicals

Author Posting. © Springer, 2007. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Ecotoxicology 16 (2007): 205-219, doi:10.1007/s10646-006-0122-0.Investigative efforts into the potential endocrine-disrupting effects of chemicals have mainly concentrated on vertebrates, with significantly less attention paid to understanding potential endocrine disruption in the invertebrates. Given that invertebrates account for at least 95% of all known animal species and are critical to ecosystem structure and function, it remains essential to close this gap in knowledge and research. The lack of progress regarding endocrine disruption in invertebrates is still largely due to: (1) our ignorance of mode-of-action, physiological control, and hormone structure and function in invertebrates; (2) lack of a standardized invertebrate assay; (3) the irrelevance to most invertebrates of the proposed activity-based biological indicators for endocrine disruptor exposure (androgen, estrogen and thyroid); (4) limited field studies. Past and ongoing research efforts using the standard invertebrate toxicity test model, the mysid shrimp, have aimed at addressing some of these issues. The present review serves as an update to a previous publication on the use of mysid shrimp for the evaluation of endocrine disruptors (Verslycke et al., 2004a). It summarizes recent investigative efforts that have significantly advanced our understanding of invertebrate-specific endocrine toxicity, population modeling, field studies, and transgeneration standard test development using the mysid model.Supported by a Fellowship of the Belgian American Educational Foundation