16,906 research outputs found

    Diet of oceanic loggerhead sea turtles (Caretta caretta) in the central North Pacific

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    Diet analysis of 52 loggerhead sea turtles (Caretta caretta) collected as bycatch from 1990 to 1992 in the high-seas driftnet fishery operating between lat. 29.5°N and 43°N and between long. 150°E and 154°W demonstrated that these turtles fed predominately at the surface; few deeper water prey items were present in their stomachs. The turtles ranged in size from 13.5 to 74.0 cm curved carapace length. Whole turtles (n =10) and excised stomachs (n= 42) were frozen and transported to a laboratory for analysis of major faunal components. Neustonic species accounted for four of the five most common prey taxa. The most common prey items were Janthina spp. (Gastropoda); Carinaria cithara Benson 1835 (Heteropoda); a chondrophore, Velella velella (Hydrodia); Lepas spp. (Cirripedia), Planes spp. (Decapoda: Grapsidae), and pyrosomas (Pyrosoma spp.)

    Evolution of satellite DNAs in the genus Apodemus

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    The effect of moving on union dissolution

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    This paper examines the effect of migration and residential mobility on union dissolution among married and cohabiting couples. While there is a large, multi-disciplinary literature looking at the determinants of union dissolution in Europe and North America, the possible impact of geographical mobility has received little attention. This is despite the fact that moving is a stressful life event and that numerous studies suggest that women’s economic well-being and employment suffer from family moves which are usually stimulated by the man’s career. We base our longitudinal analysis on retrospective event-history data from Austria and apply hazard regression. Our results show that couples who move frequently have a significantly higher risk of union dissolution. We argue that frequent moving increases couple stress and union instability through a variety of mechanisms.Austria, dissolution of marriage, event history analysis, internal migration, residential mobility

    The development and application of aerodynamic uncertainties: And flight test verification for the space shuttle orbiter

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    The approach used in establishing the predicted aerodynamic uncertainties and the process used in applying these uncertainties during the design of the Orbiter flight control system and the entry trajectories are presented. The flight test program that was designed to verify the stability and control derivatives with a minimum of test flights is presented and a comparison of preflight predictions with preliminary flight test results is made. It is concluded that the approach used for the Orbiter is applicable to future programs where testing is limited due to time constraints or funding

    Electrostatic protection of the Solar Power Satellite and rectenna

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    Several features of the interactions of the solar power satellite (SPS) with its space environment were examined theoretically. The voltages produced at various surfaces due to space plasmas and the plasma leakage currents through the kapton and sapphire solar cell blankets were calculated. At geosynchronous orbit, this parasitic power loss is only 0.7%, and is easily compensated by oversizing. At low-Earth orbit, the power loss is potentially much larger (3%), and anomalous arcing is expected for the EOTV high voltage negative surfaces. Preliminary results of a three dimensional self-consistent plasma and electric field computer program are presented, confirming the validity of the predictions made from the one dimensional models. Magnetic shielding of the satellite, to reduce the power drain and to protect the solar cells from energetic electron and plasma ion bombardment is considered. It is concluded that minor modifications can allow the SPS to operate safely and efficiently in its space environment. The SPS design employed in this study is the 1978 MSFC baseline design utilizing GaAs solar cells at CR-2 and an aluminum structure

    Influence of Decompression Rate on Hemodynamic Compensation to Continuous Lower Body Negative Pressure

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    We applied lower body negative pressure (LBNP) continuously, at three decompression rates, in an attempt to simulate uncontrolled hemorrhage as might be experienced by victims of traumatic injury. The purpose of our study was to determine whether hemodynamic compensations to simulated hemorrhage depend more on the magnitude, or the rate of change in pressure applied. Forty five (45) young, healthy subjects participated. We recorded the electrocardiogram, beat-to-beat arterial pressure (finger photoplethysmography), and measured cardiac output (inert gas rebreathing to calculate stroke volume) during continuous LBNP applied at three different decompression rates (n = 15 subjects for each rate; slow = 3 mm Hg∙min-1; medium = 6 mm Hg∙min-1; and fast = 12 mm Hg∙min-1) to an ending pressure of -60 mmHg. Slopes relating changes of dependent variable responses to the magnitude of decompression were calculated with linear regression, and group results were compared with ANOVA. LBNP increased (pooled across groups from 0 to -60 mmHg) heart rates (+28%; p ≤ .05 ), and decreased mean arterial pressures (-10%; p ≤ .05) and stroke volumes (-66%; p ≤ .05). The magnitude of changes induced by LBNP were not different between groups (p ≥ .4). Slopes (pooled across groups) relating heart rate (.3 bpm/mmHg ), mean arterial pressure (-.16 mmHg/mmHg), and stroke volume (-1.3 ml/mmHg) to the level of LBNP applied were not dependent on decompression rate (all ANOVA comparisons, p ≥ .3). We conclude that hemodynamic changes during continuous LBNP are associated directly with the magnitude of pressure applied, irrespective of the rate of decompression. Our results suggest that hemodynamic compensations to simulated uncontrolled hemorrhage are robust, and are not compromised by increasing the speed of decompression to simulate a greater rate of blood loss

    Factors Influencing Largemouth Bass Recruitment: Implications for the Illinois Management and Stocking Program

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    Annual Progress Report issued August 2002; NOTE: Two different reports numbered 02/06 were issued from the CAE.Report issued on: August 2002INHS Technical Report prepared for Division of Fisheries Illinois Department of Natural Resource

    Synthetic Observations of Simulated Radio Galaxies I: Radio and X-ray Analysis

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    We present an extensive synthetic observational analysis of numerically- simulated radio galaxies designed to explore the effectiveness of conventional observational analyses at recovering physical source properties. These are the first numerical simulations with sufficient physical detail to allow such a study. The present paper focuses on extraction of magnetic field properties from nonthermal intensity information. Synchrotron and inverse-Compton intensities provided meaningful information about distributions and strengths of magnetic fields, although considerable care was called for. Correlations between radio and X-ray surface brightness correctly revealed useful dynamical relationships between particles and fields. Magnetic field strength estimates derived from the ratio of X-ray to radio intensity were mostly within about a factor of two of the RMS field strength along a given line of sight. When emissions along a given line of sight were dominated by regions close to the minimum energy/equipartition condition, the field strengths derived from the standard power-law-spectrum minimum energy calculation were also reasonably close to actual field strengths, except when spectral aging was evident. Otherwise, biases in the minimum- energy magnetic field estimation mirrored actual differences from equipartition. The ratio of the inverse-Compton magnetic field to the minimum-energy magnetic field provided a rough measure of the actual total energy in particles and fields in most instances, within an order of magnitude. This may provide a practical limit to the accuracy with which one may be able to establish the internal energy density or pressure of optically thin synchrotron sources.Comment: 43 pages, 14 figures; accepted for publication in ApJ, v601 n2 February 1, 200
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