227 research outputs found

    KH 15D: A Spectroscopic Binary

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    We present the results of a high-resolution spectroscopic monitoring program of the eclipsing pre-main-sequence star KH 15D that reveal it to be a single-line spectroscopic binary. We find that the best-fit Keplerian model has a period P = 48.38 days, which is nearly identical to the photometric period. Thus, we find the best explanation for the periodic dimming of KH 15D is that the binary motion carries the currently visible star alternately above and below the edge of an obscuring cloud. The data are consistent with the models involving an inclined circumstellar disk, as recently proposed by Winn et al. (2004) and Chiang & Murray-Clay (2004). We show that the mass ratio expected from models of PMS evolution, together with the mass constraints for the visible star, restrict the orbital eccentricity to 0.68 < e < 0.80 and the mass function to 0.125 < Fm < 0.5 Msun.Comment: 8 pages, 4 figures, 3 tables, accepted for publication in September AJ. Discussion of rotational velocity deferred to Hamilton, et al. (2004, in prep). Previously reported vsini value in error; Replaced Table 3 with new Figure 3; Added new Table 2 showing individual radial velocities w.r.t. each reference star; Fixed typo in Figure

    FEMA's Integration of Preparedness and Development of Robust Regional Offices

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    In October 2006, Congress enacted major legislation to reform the function and organization of the Federal Emergency Management Agency (FEMA) in response to the recognized failures in preparation for and response to Hurricane Katrina. The Post-Katrina Emergency Management Reform Act of 2006 (PKEMRA) focused national preparedness responsibilities within FEMA and directed additional resources and responsibilities to FEMA's ten regional offices. Directed by Congress, in October 2008 a National Academy Panel began an independent assessment of FEMA's integration of preparedness functions and progress in development of robust regional offices.Main FindingsOver the past three years, FEMA has taken significant steps in an effort to integrate preparedness and develop more robust regional offices. These efforts, undertaken by both the previous and current Administrations, are documented throughout this report and should be recognized and applauded. However, FEMA has yet to define specific goals and outcomes that would permit it, Congress or the public to determine when preparedness has been fully integrated into all aspects of FEMA's work and whether the development and ongoing operation of robust regional offices has been achieved. In the absence of well-defined, measurable outcome indicators, the National Academy Panel relied upon the assessments of FEMA leaders and staff, documentation provided by FEMA, and a review of secondary sources material to inform its findings and recommendations. Based upon this evidence, the Panel has concluded that, while progress has been made: (1) preparedness is not fully integrated across FEMA, (2) FEMA's regional offices do not yet have the capacity required to ensure the nation is fully prepared, (3) stakeholders are not yet full partners with FEMA in national preparedness, and (4) FEMA has ineffective internal business practices, particularly with regard to human resource management. The Panel made seven recommendations for FEMA:Establish a cross-organizational process, with participation from internal and external stakeholders, to develop a shared understanding of preparedness integrationEstablish a robust set of outcome metrics and standards for preparedness integration, as well as a system to monitor and evaluate progress on an ongoing basisWork to eliminate organizational barriers that are adversely impacting the full integration of preparedness across the agencyContinue to build regional office capacity and monitor implementation consistent with the Administrator's recent policy guidanceUndertake steps to improve the ongoing working relationship between headquarters and the regions in accord with Panel-identified principlesTake steps to improve stakeholder engagement and relationships at all levels in accord with Panel-identified principles; andStrengthen internal business practices, especially in the area of human capital planning

    What Really Matters: Assessing Individual Problem-Solving Performance in the Context of Biological Sciences

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    The evaluation of higher-level cognitive skills can augment traditional discipline-based knowledge testing by providing timely assessment of individual student problem-solving abilities that are critical for success in any professional development program. However, the wide-spread acceptance and implementation of higher level cognitive skills analysis has been delayed by the lack of rapid, valid, and reliable quantified-scoring techniques. At the University of New Mexico School of Medicine, Department of Biochemistry & Molecular Biology, we have developed an examination format that can be routinely and sequentially implemented for both formative and summative assessments of individual students in large classes. Rather than providing results in terms of an individual student’s knowledge base in a single academic discipline or group of disciplines, this type of examination provides information on performance in the application of specific problem-solving skills, which we term “domains,” to a contextual clinical or scientific problem. These domains, derived from the scientific method, are tested across various academic disciplines, and are reported in terms of the following: Initial and sequential hypothesis generation, investigation of these hypotheses, evaluation of newly acquired data, integration of basic science mechanisms with new information to explain the basis of the problem, and reflection on one’s own professional development in the context of the examination. The process for criterion referenced quantified grading of the examination is outlined in this paper. This process involves relatively rapid scoring, and permits the timely use of the resulting information for individual student feedback as well as curricular improvement. Data regarding grading consistency and comparison with other measures of student performance is also presented in this paper. An analysis of the performance characteristics of this examination, which has been utilized for over 10 years in a variety of course settings, indicates that it is valid, reliable, and utilizable. As such, the methodology is now routinely used in several undergraduate and graduate level biochemistry classes to monitor the development of individual student problem-solving abilities

    Further evidence for the planet around 51 Pegasi

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    The discovery of the planet around the solar-type star 51 Pegasi marked a watershed in the search for extrasolar planets. Since then seven other solar-type stars have been discovered, of which several have surprisingly short orbital periods, like the planet around 51 Peg. These planets were detected using the indirect technique of measuring variations in the Doppler shifts of lines in the spectra of the primary stars. But it is possible that oscillations of the stars themselves (or other effects) could mimic the signature of the planets, particularly around the short-period planets. The apparent lack of spectral and brightness variations, however, led to widespread acceptance that there is a planet around 51 Peg. This conclusion was challenged by the observation of systematic variations in the line profile shapes of 51 Peg, which suggested stellar oscillations. If these observations are correct, then there is no need to invoke a planet around 51 Peg to explain the data. Here we report observations of 51 Peg at a much higher spectral resolution than those in ref.9, in which we find no evidence for systematic changes in the line shapes. The data are most consistent with a planetary companion to 51 Peg.Comment: LaTeX, 6 pages, 2 figures. To appear in 8 January 1998 issue of Natur

    Створення та тестування спеціалізованих словників для аналізу тексту

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    Practitioners in many domains–e.g., clinical psychologists, college instructors, researchers–collect written responses from clients. A well-developed method that has been applied to texts from sources like these is the computer application Linguistic Inquiry and Word Count (LIWC). LIWC uses the words in texts as cues to a person’s thought processes, emotional states, intentions, and motivations. In the present study, we adopt analytic principles from LIWC and develop and test an alternative method of text analysis using naïve Bayes methods. We further show how output from the naïve Bayes analysis can be used for mark up of student work in order to provide immediate, constructive feedback to students and instructors.Робота фахівців-практиків у багатьох галузях, наприклад, клінічних психологів, викладачів кол д ів, дослідників п р дбача збір пись ових відповід хніх клі нтів чи студ нтів. обр розробл ни тод, яки застосову ться сьогодні до т кстів такого типу, ц ко п’ют рни додаток Linguistic Inquiry and Word Count (LIWC). Програма LIWC тракту слова в т кстах як індикатори нтальних проц сів людини, оці них станів, на ірів і отивів. У статті використано аналітичні принципи LIWC, розробл но та прот стовано альт рнативни тод аналізу т ксту з використання тодів на вного ба сового класифікатора. Автори д онструють, як р зультати аналізу за на вни ба сови класифікаторо о уть бути використані для аналізу студ нтсько роботи з тою надання н га ного, конструктивного зворотного зв’язку і студ нта і викладача

    The California Planet Survey. I. Four New Giant Exoplanets

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    We present precise Doppler measurements of four stars obtained during the past decade at Keck Observatory by the California Planet Survey (CPS). These stars, namely, HD 34445, HD 126614, HD 13931, and Gl 179, all show evidence for a single planet in Keplerian motion. We also present Doppler measurements from the Hobby-Eberly Telescope (HET) for two of the stars, HD 34445 and Gl 179, that confirm the Keck detections and significantly refine the orbital parameters. These planets add to the statistical properties of giant planets orbiting near or beyond the ice line, and merit follow-up by astrometry, imaging, and space-borne spectroscopy. Their orbital parameters span wide ranges of planetary minimum mass (M sin i = 0.38-1.9 M(Jup)), orbital period (P = 2.87-11.5 yr), semimajor axis (a = 2.1-5.2 AU), and eccentricity (e = 0.02-0.41). HD 34445 b (P = 2.87 yr, M sin i = 0.79 MJup, e = 0.27) is a massive planet orbiting an old, G-type star. We announce a planet, HD 126614 Ab, and an M dwarf, HD 126614 B, orbiting the metal-rich star HD 126614 (which we now refer to as HD 126614 A). The planet, HD 126614 Ab, has minimum mass M sin i = 0.38 MJup and orbits the stellar primary with period P = 3.41 yr and orbital separation a = 2.3 AU. The faint M dwarf companion, HD 126614 B, is separated from the stellar primary by 489 mas (33 AU) and was discovered with direct observations using adaptive optics and the PHARO camera at Palomar Observatory. The stellar primary in this new system, HD 126614 A, has the highest measured metallicity ([ Fe/ H] = + 0.56) of any known planet-bearing star. HD 13931 b (P = 11.5 yr, M sin i = 1.88 MJup, e = 0.02) is a Jupiter analog orbiting a near solar twin. Gl 179 b (P = 6.3 yr, M sin i = 0.82 M(Jup), e = 0.21) is a massive planet orbiting a faint M dwarf. The high metallicity of Gl 179 is consistent with the planet-metallicity correlation among M dwarfs, as documented recently by Johnson & Apps.NSF AST-0702821NASA NNX06AH52GMcDonald Observator
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