2,333 research outputs found

    Adaptive Optics Simulations for Siding Spring

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    Using an observational derived model optical turbulence profile (model-OTP) we have investigated the performance of Adaptive Optics (AO) at Siding Spring Observatory (SSO), Australia. The simulations cover the performance for AO techniques of single conjugate adaptive optics (SCAO), multi-conjugate adaptive optics (MCAO) and ground-layer adaptive optics (GLAO). The simulation results presented in this paper predict the performance of these AO techniques as applied to the Australian National University (ANU) 2.3 m and Anglo-Australian Telescope (AAT) 3.9 m telescopes for astronomical wavelength bands J, H and K. The results indicate that AO performance is best for the longer wavelengths (K-band) and in the best seeing conditions (sub 1-arcsecond). The most promising results are found for GLAO simulations (field of view of 180 arcsecs), with the field RMS for encircled energy 50% diameter (EE50d) being uniform and minimally affected by the free-atmosphere turbulence. The GLAO performance is reasonably good over the wavelength bands of J, H and K. The GLAO field mean of EE50d is between 200 mas to 800 mas, which is a noticeable improvement compared to the nominal astronomical seeing (870 to 1700 mas).Comment: 15 pages; accepted for publication in PAS

    Interstellar lines in the spectrum of supernova 1987a

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    The primary interest was to analyze the interstellar lines produced by gases along the line of sight which resides in the galactic plane and halo, as well as material in the Large Magellanic Cloud or the immediate environment of the supernovae. The ionization and fine-structure excitation of assorted atoms were intrepreted. The goal was to learn more about conditions in various regions of space and identify the probable origins for some velocity components whose locations were uncertain

    M.S.L.A.P. Modular Spectral Line Analysis Program documentation

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    MSLAP is a software for analyzing spectra, providing the basic structure to identify spectral features, to make quantitative measurements of this features, and to store the measurements for convenient access. MSLAP can be used to measure not only the zeroth moment (equivalent width) of a profile, but also the first and second moments. Optical depths and the corresponding column densities across the profile can be measured as well for sufficiently high resolution data. The software was developed for an interactive, graphical analysis where the computer carries most of the computational and data organizational burden and the investigator is responsible only for all judgement decisions. It employs sophisticated statistical techniques for determining the best polynomial fit to the continuum and for calculating the uncertainties

    RoMEO Studies 8: self-archiving: the logic behind the colour-coding used in the Copyright Knowledge Bank

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    Purpose – The purpose of this research is to show how the self-archiving of journal papers is a major step towards providing open access to research. However, copyright transfer agreements (CTAs) that are signed by an author prior to publication often indicate whether, and in what form, self-archiving is allowed. The SHERPA/RoMEO database enables easy access to publishers' policies in this area and uses a colour-coding scheme to classify publishers according to their self-archiving status. The database is currently being redeveloped and renamed the Copyright Knowledge Bank. However, it will still assign a colour to individual publishers indicating whether pre-prints can be self-archived (yellow), post-prints can be self-archived (blue), both pre-print and post-print can be archived (green) or neither (white). The nature of CTAs means that these decisions are rarely as straightforward as they may seem, and this paper describes the thinking and considerations that were used in assigning these colours in the light of the underlying principles and definitions of open access. Approach – Detailed analysis of a large number of CTAs led to the development of controlled vocabulary of terms which was carefully analysed to determine how these terms equate to the definition and “spirit” of open access. Findings – The paper reports on how conditions outlined by publishers in their CTAs, such as how or where a paper can be self-archived, affect the assignment of a self-archiving colour to the publisher. Value – The colour assignment is widely used by authors and repository administrators in determining whether academic papers can be self-archived. This paper provides a starting-point for further discussion and development of publisher classification in the open access environment

    Human Immunodeficiency Virus Prevention Education on Knowledge and Condom Use among African American Males in Clayton County, GA

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    Purpose: Georgia remains fourth in the nation for new HIV cases. Young African American adults are responsible for 49% of the new cases in Georgia. The purpose of this project was to explore the effectiveness of a nurse led HIV prevention education program on increasing knowledge of HIV prevention and increasing the frequency of condom use among males between the ages of 18-30 years old in Clayton County, Georgia. Methods: This educational intervention was implemented in a primary care clinic. Data on knowledge and condom use as well as sexual health, sexual behavior, sexual communication, and perceptions of risk for HIV infection was collected.  Content from the CDC designated effective program, NIA, a small group-level intervention was used. A twenty-one item pretest was administered to participants. CDC approved fact sheets and electronic quizzes were also administered. Results: Thirty African American male participants were recruited. The mean age of each participant was 24 year old. Most participants reported completing at least one year of college. The project had a 50% response rate. Approximately 26% of African American men believed the highest form of HIV transmission came from saliva and 28% believed blood was the second highest form of HIV trans- mission. Participants believed feces, mucus and sweat were among the lowest forms of HIV transmission in this cohort. All participants believed condom use prevented transmission of HIV to partners. Conclusion: For the advanced practice nurse, incorporating HIV prevention education into routine visits, may facilitate HIV prevention behaviors in patients
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