858 research outputs found

    High School Science Teachers and Forestry Education: How are they Connected?

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    A quantitative study of high school science teachers in the five state Southern Piedmont region of the United States investigating their attitudes toward and understanding of forestry as well as the extent to which they are teaching forestry concepts was conducted. Specific factors that were addressed include teachers’ attitudes toward the impacts of forest management, specific forest management practices, forest management goals, the forestry profession, and forestry education. The primary method of data collection for this study was a web-based survey and data analysis included calculating descriptive statistics, performing exploratory factor analysis and producing several regression models. Very few similar studies have previously occurred and even fewer in the critically important southeastern U.S. forestry region. The study will provide insight into the way teachers think as well as levels of high school student exposure to forestry concepts. Results may also help to clarify enrollment trends in in college forestry and natural resource programs. Results will be discussed in the context of variation in attitudinal, knowledge-based, education, and demographic variables

    Causality in Political Networks

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    As the study of political networks becomes more common in political science, greater attention to questions of causality is warranted. This essay explores competing visions of causality in political networks. Independent essays address issues of statistical model specification, identification of multi-step personal influence, measurement error, causality in historical perspective, and the insights of field experiments. These essays do not agree entirely on the nature of causality in political networks, though they commonly take seriously concerns regarding homophily, time- consistency, and the uniqueness of political network data. Serious consideration of these methodological issues promises to enhance the value-added of network analysis in the study of politics

    The IRAS Minor Planet Survey

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    This report documents the program and data used to identify known asteroids observed by the Infrared Astronomical Satellite (IRAS) and to compute albedos and diameters from their IRAS fluxes. It also presents listings of the results obtained. These results supplant those in the IRAS Asteroid and Comet Survey, 1986. The present version used new and improved asteroid orbital elements for 4679 numbered asteroids and 2632 additional asteroids for which at least two-opposition elements were available as of mid-1991. It employed asteroid absolute magnitudes on the International Astronomical Union system adopted in 1991. In addition, the code was modified to increase the reliability of associating asteroids with IRAS sources and rectify several shortcomings in the final data products released in 1986. Association reliability was improved by decreasing the position difference between an IRAS source and a predicted asteroid position required for an association. The shortcomings addressed included the problem of flux overestimation for low SNR sources and the systematic difference in albedos and diameters among the three wavelength bands (12, 25, and 60 micrometers). Several minor bugs in the original code were also corrected

    Function, Adjustment, Quality of Life and Symptoms (FAQS) in Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) Survivors: A Study Protocol

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    <p>Abstract</p> <p>Background</p> <p>The population of survivors following allogeneic HSCT continues to increase, and yet their experiences of recovery and long-term survivorship have not been fully characterized. This paper presents a study protocol examining over time the functional status, psychosocial adjustment, health-related quality of life, and symptom experience of survivors who have undergone allogeneic transplantation. The aims of the study are to: 1) explore the patterns of change in these health outcomes during the survivorship phase; 2) characterize subgroups of survivors experiencing adverse outcomes; and 3) examine relationships among outcomes and demographic and clinical factors (such as age, graft-versus-host disease (GVHD), and disease relapse).</p> <p>Methods</p> <p>In this longitudinal observational study, adults who survive a minimum of 3 years from date of allogeneic transplantation complete a series of questionnaires annually. Demographic and clinical data are collected along with a series of patient-reported outcome measures, specifically: 1) Medical Outcomes Study SF- 36; 2) Functional Assessment of Chronic Illness Therapy (FACIT) - General, 3) FACIT-Fatigue; 4) FACIT- Spiritual; 5) Psychosocial Adjustment to Illness Scale; 6) Rotterdam Symptom Checklist-Revised; and 7) Pittsburgh Sleep Quality Index.</p> <p>Conclusions</p> <p>This study will provide multidimensional patient-reported outcomes data to expand the understanding of the survivorship experience across the trajectory of allogeneic transplantation recovery. There are a number of inherent challenges in recruiting and retaining a diverse and representative sample of long-term transplant survivors. Study results will contribute to an understanding of outcomes experienced by transplant survivors, including those with chronic GVHD, malignant disease relapse, and other late effects following allogeneic transplantation.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00128960">NCT00128960</a></p

    Book Reviews

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    Search for Ultra High Energy (UHE) Îł-ray counterparts of BATSE 3B catalog events

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    We search for a Ultra High Energy (E>1014 eV)(E>1014eV) counterpart source to cosmic Îł-ray bursts detected with the BATSE detectors. Using the 3B catalog positions, we examine 115 candidate bursts with the CASA-MIA detector for UHE Îł-ray emission at or near the time of the observed Îł-ray burst. No statistically significant excess of Îł-rays is found from any of the candidate event regions. Based upon these results, we calculate the flux limits for UHE emission from these candidate event regions. Typical 95% confidence level flux limits are about 6×10−12 γ  cm−2 sec−16×10−12Îłcm−2sec−1 at a Îł-ray detection threshold of 160 TeV. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87368/2/598_1.pd

    Dating Granites Using CODEX, with Application to In Situ Dating on the Moon

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    We have measured 87Rb–87Sr isochron ages for two granites, using the breadboard version of our Chemistry, Organics, and Dating EXperiment (CODEX), a laser-ablation resonance-ionization mass spectrometer designed for in situ geochronology on the Moon or Mars. These measurements extend the demonstrated analytical capabilities of CODEX, and indicate the value of incorporating a flight-ready version of CODEX, now under construction, into a future mission payload. We used CODEX to obtain accurate ages for the 1700 Ma Boulder Creek Granite, with 1σ statistical precision of 110 Myr, and for the 1100 Ma Pikes Peak Granite, with 1σ statistical precision of 160 Myr. To provide an end-to-end illustration of how CODEX analysis of granites can address critical lunar science questions regarding rock age and composition in situ, we describe an example mission to the lunar Gruithuisen Domes. Gruithuisen Domes appear to be volcanic edifices of granitic composition. Orbital remote sensing suggests that granitic rocks represent only a small fraction of the lunar surface, and the mere fact of their existence on the Moon is a puzzle. CODEX determination of the timing and process of their formation, both presently ill-understood, would provide important constraints on the thermal and geochemical evolution of the lunar interior

    How many sigmas is the solar neutrino effect?

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    The minimal standard electroweak model can be tested by allowing all the solar neutrino fluxes, with undistorted energy spectra, to be free parameters in fitting the measured solar neutrino event rates, subject only to the condition that the total observed luminosity of the sun is produced by nuclear fusion. The rates of the five experiments prior to SNO (chlorine, Kamiokande, SAGE, GALLEX, Super-Kamiokande) cannot be fit by an arbitrary choice of undistorted neutrino fluxes at the level of 2.5 sigma (formally 99% C.L.). Considering just SNO and Super-Kamiokande, the discrepancy is at the 3.3 sigma level(10^{-3} C.L.). If all six experiments are fit simultaneously, the formal discrepancy increases to 4 sigma (7*10^{-5} C.L.). If the relative scaling in temperature of the nuclear reactions that produce 7Be and 8B neutrinos is taken into account, the formal discrepancy is at the 7.4 sigma level.Comment: 1 figure; related information at http://www.sns.ias.edu/~jn
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