9,749 research outputs found

    Search for nearby stars among proper motion stars selected by optical-to-infrared photometry. II. Two late M dwarfs within 10 pc

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    We have identified two late M dwarfs within 10 parsecs of the Sun, by cross-correlating the Luyten NLTT catalogue of stars with proper motions larger than 0.18 arcsec/yr, with objects lacking optical identification in the 2MASS data base. The 2MASS photometry was then combined with improved optical photometry obtained from the SuperCOSMOS Sky Surveys. The two objects (LP775-31 and LP655-48) have extremely red optical-to-infrared colours ((R-K)~7) and very bright infrared magnitudes (K_s<10): follow-up optical spectroscopy with the ESO 3.6-m telescope gave spectral types of M8.0 and M7.5 dwarfs, respectively. Comparison of their near-infrared magnitudes with the absolute magnitudes of known M8 and M7.5 dwarfs with measured trigonometric parallaxes yields spectroscopic distance estimates of 6.4+/-1.4 parsecs and 8.0+/-1.6 parsecs for LP775-31 and LP655-48, respectively. In contrast, Cruz & Reid (2002) recently determined spectral types of M6 for both objects, and commensurately larger distances of 11.3+/-1.3 parsecs and 15.3+/-2.6 parsecs. LP655-48 is also a bright X-ray source (1RXS J044022.8-053020). With only a few late M dwarfs previously known within 10 parsecs, these two objects represent an important addition to the census of the Solar neighbourhood.Comment: Astronomy & Astrophysics (Letters), in press; 5 pages, 1 figure, uses aa.cls version 5.

    Assessing old-age long-term care using the concepts of healthy life expectancy and care duration: the new parameter "Long-Term Care-Free Life-Expectancy (LTCF)"

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    Achieving old ages is also connected with prevalence of illness and long-term care. With the introduction of the statutory long-term care insurance in 1996 and the long-term care statistics in 1999 research data of about 2.3 million people receiving long-term care benefits is available. Average life expectancy can be qualitatively divided into lifetime spent in good health and lifetime spent in long-term care dependence (average care duration). In Germany women’s and men’s average care duration amount 3.6 years respectively 2.1 years.Germany, ageing, laboratories, life expectancy

    Search for nearby stars among proper motion stars selected by optical-to-infrared photometry. I. Discovery of LHS 2090 at spectroscopic distance of d=6pc

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    We present the discovery of a previously unknown very nearby star - LHS 2090 at a distance of only d=6 pc. In order to find nearby (i.e. d < 25 pc) red dwarfs, we re-identified high proper motion stars (ÎŒ>\mu > 0.18 arcsec/yr) from the NLTT catalogue (Luyten \cite{luyten7980}) in optical Digitized Sky Survey data for two different epochs and in the 2MASS data base. Only proper motion stars with large R−KsR-K_s colour index and with relatively bright infrared magnitudes (Ks<10K_s<10) were selected for follow-up spectroscopy. The low-resolution spectrum of LHS 2090 and its large proper motion (0.79 arcsec/yr) classify this star as an M6.5 dwarf. The resulting spectroscopic distance estimate from comparing the infrared JHKsJHK_s magnitudes of LHS 2090 with absolute magnitudes of M6.5 dwarfs is 6.0±1.16.0\pm1.1 pc assuming an uncertainty in absolute magnitude of ±\pm0.4 mag.Comment: 3 pages, 1 figure, accepted for publication in Astronomy and Astrophysics Letter

    SSSPM J1444-2019: an extremely high proper motion, ultracool subdwarf

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    We present the discovery of a new extreme high proper motion object (3.5 arcsec/year) which we classify as an ultracool subdwarf with [M/H] = -0.5. It has a formal spectral type of sdM9 but also shows L-type features: while the VO bands are completely absent, it exhibits extremely strong TiO absorption in its optical spectrum. With a radial velocity of about -160 km/s and a rough distance estimate of 16--24 pc, it is likely one of the nearest halo members crossing the Solar neighbourhood with a heliocentric space velocity of (U,V,W)=(-244,-256,-100)+/-(32,77,6) km/s.Comment: 4 pages, 4 figures (Fig.1a-d available as jpg files), accepted for publication in Astronomy & Astrophysics Letter

    An Introduction to Slice-Based Cohesion and Coupling Metrics

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    This report provides an overview of slice-based software metrics. It brings together information about the development of the metrics from Weiser’s original idea that program slices may be used in the measurement of program complexity, with alternative slice-based measures proposed by other researchers. In particular, it details two aspects of slice-based metric calculation not covered elsewhere in the literature: output variables and worked examples of the calculations. First, output variables are explained, their use explored and standard reference terms and usage proposed. Calculating slice-based metrics requires a clear understanding of ‘output variables’ because they form the basis for extracting the program slices on which the calculations depend. This report includes a survey of the variation in the definition of output variables used by different research groups and suggests standard terms of reference for these variables. Our study identifies four elements which are combined in the definition of output variables. These are the function return value, modified global variables, modified reference parameters and variables printed or otherwise output by the module. Second, slice-based metric calculations are explained with the aid of worked examples, to assist newcomers to the field. Step-by-step calculations of slice-based cohesion and coupling metrics based on the vertices output by the static analysis tool CodeSurfer (R) are presented and compared with line-based calculations

    Lifetime earnings and life expectancy

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    We estimate remaining life expectancy at age 65 using a very large sample of male German pensioners. Our analysis is entirely nonparametric. Furthermore, the data enable us to compare life expectancy in eastern and western Germany conditional on a measure of socio-economic status. Our findings show a lower bound of almost fifty percent (six years) on the difference in remaining life expectancy between the lowest and the highest socio-economic group considered. Within groups, we find similar values for East and West. Our analysis contributes to the literature in several aspects. First, Germany is clearly underrepresented in differential mortality studies. Second, we are able to use a novel measure of lifetime earnings as a proxy for socio-economic status that remains valid for retired people. Third, the comparison of eastern and western Germany may provide some interesting insights for transformation countries.Germany, life expectancy, pensioners, socio-economic differentials

    Month of birth influences survival up to age 105+: first results from the age validation study of German semi-supercentenarians

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    Using data from Germany, we examine if month of birth influences survival up to age 105. Since age reporting at the highest ages is notoriously unreliable we draw on age-validated information from a huge age validation project of 1487 alleged German semi-supercentenarians aged 105+. We use month of birth as an exogenous indicator for seasonal changes in the environment around the time of birth. We find that the seasonal distribution of birth dates changes with age. For 925 age-validated semi-supercentenarians the seasonality is more pronounced than at the time of their births (1880-1900). Among the December-born the relative risk of survival from birth to age 105+ is 16 per cent higher than the average, among the June-born, 23 per cent lower. The month-of-birth pattern in the survival risks of the German semi-supercentenarians resembles closely the month-of-birth pattern in remaining life expectancy at age 50 in Denmark.

    Differential mortality by lifetime earnings in Germany

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    e estimate mortality rates by a measure of socio-economic status in a very large sample of male German pensioners aged~65 or older. Our analysis is entirely nonparametric. Furthermore, the data enable us to compare mortality experiences in eastern and western Germany conditional on socio-economic status. As a simple summary measure, we compute period life expectancies at age~65. Our findings show a lower bound of almost 50 percent (six years) on the difference in life expectancy between the lowest and the highest socio-economic group considered. Within groups, we find similar values for the former GDR and western Germany. Our analysis contributes to the literature in three aspects. First, we provide the first population-based differential mortality study for Germany. Second, we use a novel measure of lifetime earnings as a proxy for socio-economic status that remains applicable to retired people. Third, the comparison between eastern and western Germany may provide some interesting insights for transformation countries.comparison East and West Germany, lifetime earnings measure, mortality and socio-economic status

    Official population statistics and the Human Mortality Database estimates of populations aged 80+ in Germany and nine other European countries

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    A systematic comparison of the Human Mortality Database and official estimates of populations aged 80+ is presented. We consider statistical series for East and West Germany and also for Denmark, England and Wales, France, Finland, Hungary, the Netherlands, Russia, Sweden, and Switzerland. The Human Mortality Database (HMD, www.mortality.org) methodology relies on the methods of extinct and almost extinct generations. HMD estimates are precise if the quality of death data is high and the migration among the elderly is negligible. The comparisons between the HMD and the official populations are not fully appropriate for the 1990s since the HMD calculations are related to official population estimates. A significant overestimation of the male population aged 80+ and especially 90+ between the censuses of 1970 and 1987 was found in West Germany. The relative surplus of men aged 90+ increased from 5 to 20 percent, which expressed in absolute numbers indicates an increase from 2 to 10 thousand. In 1971-1987 the official death rates have fallen dramatically to implausibly low values. In 1987-88 death rates based on the official populations suddenly jumped to the HMD death rates due to the census re-estimation. In the 1990s an accelerated decrease in male death rates has resumed. Among other countries, the relative and absolute deviations from the HMD estimates were especially high in Russia, Hungary, and England and Wales. Regression analysis reveals common factors of the relative deviation from the HMD populations. The deviation tends to decrease with time, increase with age, be higher during inter-census periods than in census years, and to decrease after the introduction of population registers.age/aging, elderly, population estimates, quality of statistics, statistics

    Shuttle Ground Operations Efficiencies/Technologies Study (SGOE/T). Volume 5: Technical Information Sheets (TIS)

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    The Technology Information Sheet was assembled in database format during Phase I. This document was designed to provide a repository for information pertaining to 144 Operations and Maintenance Instructions (OMI) controlled operations in the Orbiter Processing Facility (OPF), Vehicle Assembly Building (VAB), and PAD. It provides a way to accumulate information about required crew sizes, operations task time duration (serial and/or parallel), special Ground Support Equipment (GSE). required, and identification of a potential application of existing technology or the need for the development of a new technolgoy item
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