4,394 research outputs found

    Perceptions of Educational Leadership Faculty Regarding Open Access Publishing

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    There is a dearth of research on the perceptions of faculty members in educational leadership regarding open access publications. This reality may exist because of a lack of funding for educational leadership research, financial obstacles, tenure demands, or reputation concerns. It may be that there are simply fewer established open access publishers with reputable impact factors to encourage publication by members in the field. The current study seeks to answer the following question: “What are the perceptions of educational leadership faculty members in UCEA about open access publishing?” The results are based on responses from 180 faculty members in the field of educational leadership

    Killing Bugs at the Bedside: A prospective hospital survey of how frequently personal digital assistants provide expert recommendations in the treatment of infectious diseases

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    BACKGROUND: Personal Digital Assistants (PDAS) are rapidly becoming popular tools in the assistance of managing hospitalized patients, but little is known about how often expert recommendations are available for the treatment of infectious diseases in hospitalized patients. OBJECTIVE: To determine how often PDAs could provide expert recommendations for the management of infectious diseases in patients admitted to a general medicine teaching service. DESIGN: Prospective observational cohort study SETTING: Internal medicine resident teaching service at an urban hospital in Dayton, Ohio PATIENTS: 212 patients (out of 883 patients screened) were identified with possible infectious etiologies as the cause for admission to the hospital. MEASUREMENTS: Patients were screened prospectively from July 2002 until October 2002 for infectious conditions as the cause of their admissions. 5 PDA programs were assessed in October 2002 to see if treatment recommendations were available for managing these patients. The programs were then reassessed in January 2004 to evaluate how the latest editions of the software would perform under the same context as the previous year. RESULTS: PDAs provided treatment recommendations in at least one of the programs for 100% of the patients admitted over the 4 month period in the 2004 evaluation. Each of the programs reviewed improved from 2002 to 2004, with five of the six programs offering treatment recommendations for over 90% of patients in the study. CONCLUSION: Current PDA software provides expert recommendations for a great majority of general internal medicine patients presenting to the hospital with infectious conditions

    Trouble Ahead, Trouble behind: Executive Branch Enforcement of Congressional Investigations

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    Job Attainment and Perceived Role Differences of Cyberschool Leaders

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    As cyberschooling options expand, it is vital that we understand the nuances of these particular learning opportunities. Because little research exists on leaders of K-12 cyberschools, this exploratory case study had two purposes. We first examined how 18 cyberschool leaders in the United States obtained their position. Second, we explored the perceptions of cyberschool leaders regarding the differences between their job and that of a traditional brick-and-mortar school leader. We found that cyberschool leaders tend to be predominantly new, technology savvy administrators who have some background in online learning. Main differences between cyberschool leadership and brick-and-mortar school leadership included interactions with students, teacher supervision, provision of professional development, and management of the day-to-day operations

    Genetic specificity and potential for local adaptation between dengue viruses and mosquito vectors

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    Background: Several observations support the hypothesis that vector-driven selection plays an important role in shaping dengue virus (DENV) genetic diversity. Clustering of DENV genetic diversity at a particular location may reflect underlying genetic structure of vector populations, which combined with specific vector genotype x virus genotype (G x G) interactions may promote adaptation of viral lineages to local mosquito vector genotypes. Although spatial structure of vector polymorphism at neutral genetic loci is well-documented, existence of G x G interactions between mosquito and virus genotypes has not been formally demonstrated in natural populations. Here we measure G x G interactions in a system representative of a natural situation in Thailand by challenging three isofemale families from field-derived Aedes aegypti with three contemporaneous low-passage isolates of DENV-1. Results: Among indices of vector competence examined, the proportion of mosquitoes with a midgut infection, viral RNA concentration in the body, and quantity of virus disseminated to the head/legs (but not the proportion of infected mosquitoes with a disseminated infection) strongly depended on the specific combinations of isofemale families and viral isolates, demonstrating significant G x G interactions. Conclusion: Evidence for genetic specificity of interactions in our simple experimental design indicates that vector competence of Ae. aegypti for DENV is likely governed to a large extent by G x G interactions in genetically diverse, natural populations. This result challenges the general relevance of conclusions from laboratory systems that consist of a single combination of mosquito and DENV genotypes. Combined with earlier evidence for fine-scale genetic structure of natural Ae. aegypti populations, our finding indicates that the necessary conditions for local DENV adaptation to mosquito vectors are met

    On the origin of irregular structure in Saturn's rings

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    We suggest that the irregular structure in Saturn's B ring arises from the formation of shear-free ring-particle assemblies of up to ~100 km in radial extent. The characteristic scale of the irregular structure is set by the competition between tidal forces and the yield stress of these assemblies; the required tensile strength of ~10^5 dyn/cm^2 is consistent with the sticking forces observed in laboratory simulations of frosted ice particles. These assemblies could be the nonlinear outcome of a linear instability that occurs in a rotating fluid disk in which the shear stress is a decreasing function of the shear. We show that a simple model of an incompressible, non-Newtonian fluid in shear flow leads to the Cahn-Hilliard equation, which is widely used to model the formation of structure in binary alloys and other systems.Comment: 21 pages, 1 figure, to be published in Astronomical Journa

    Ecological Modeling of Aedes aegypti (L.) Pupal Production in Rural Kamphaeng Phet, Thailand

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    Background - Aedes aegypti (L.) is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites. Methodology - Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts. Findings - The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types increased significantly as habitat density increased. An ecological approach, accounting for development site density, is appropriate for predicting Ae. aegypti population levels and developing efficient vector control program

    Dengue-1 Virus Clade Replacement in Thailand Associated with Enhanced Mosquito Transmission

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    International audienceDengue viruses (DENV) are characterized by extensive genetic diversity and can be organized in multiple, genetically distinct lineages that arise and die out on a regular basis in regions where dengue is endemic. A fundamental question for understanding DENV evolution is the relative extent to which stochastic processes (genetic drift) and natural selection acting on fitness differences among lineages contribute to lineage diversity and turnover. Here, we used a set of recently collected and archived low-passage DENV-1 isolates from Thailand to examine the role of mosquito vector-virus interactions in DENV evolution. By comparing the ability of 23 viruses isolated on different dates between 1985 and 2009 to be transmitted by a present-day Aedes aegypti population from Thailand, we found that a major clade replacement event in the mid-1990s was associated with virus isolates exhibiting increased titers in the vector's hemocoel, which is predicted to result in a higher probability of transmission. This finding is consistent with the hypothesis that selection for enhanced transmission by mosquitoes is a possible mechanism underlying major DENV clade replacement events. There was significant variation in transmission potential among isolates within each clade, indicating that in addition to vector-driven selection, other evolutionary forces act to maintain viral genetic diversity. We conclude that occasional adaptive processes involving the mosquito vector can drive major DENV lineage replacement events
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