7,040 research outputs found

    The Great Albatross Philippine Expedition and Its Fishes

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    The Philippine Expedition of 1907-10 was the longest and most extensive assignment of the Albatross's 39-year career. It came about because the United States had acquired the Philippines following the Spanish-American War of 1898 and the bloody Philippine Insurection of 1899-1902. The purpose of the expedition was to surbey and assess the aquatic resources of the Philippine Islands. Dr. Hugh M. Smith, the Deputy Commissioner of the U.S. Bureau of Fisheries, was the Director of the Expedition. Other scientific participants were Frederick M. Chamberlain, Lewis Radcliffe, Paul Bartsch, Harry C. Fasset, Clarence Wells, Albert Burrows, Alvin Seale, and Roy Chapman Andrews. The expedition consisted of a series of cruises, each beginning and ending in Manila and exploring a different part of the island group. In addition to the Philippines proper, the ship also explored parts of the Dutch East Indies and areas around Hong Kong and Taiwan. The expedition returned great quantities of fish and invertebrate speciments as well as hydrographic and fisheries data; most of the material was eventually deposited in the Smithsonian Institution's National Museum of Natural History. The fisehs were formally accessioned into the museum in 1922 and fell under the car of Barton A. Bean, Assistant Curator of Fishes, who then recruited Henry W. Fowler to work up the material. Fowler completed his studies of the entire collection, but only part of it was ever published, due in part to the economic constraints caused by the Depression. The material from the Philippine Expedition constituted the largest single accession of fishes ever received by the museum. These speciments are in good condition today and are still being used in scientific research

    NGC 4314. III. Inflowing Molecular Gas Feeding a Nuclear Ring of Star Formation

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    NGC 4314 is an early-type barred galaxy containing a nuclear ring of recent star formation. We present CO(1-0) interferometer data of the bar and circumnuclear region with 2.3 x 2.2 arcsec spatial resolution and 13 km/s velocity resolution acquired at the Owens Valley Radio Observatory . These data reveal a clumpy circumnuclear ring of molecular gas. We also find a peak of CO inside the ring within 2 arcsec of the optical center that is not associated with massive star formation. We construct a rotation curve from these CO kinematic data and the mass model of Combes et al. (1992). Using this rotation curve, we have identified the location of orbital resonances in the galaxy. Assuming that the bar ends at corotation, the circumnuclear ring of star formation lies between two Inner Lindblad Resonances, while the nuclear stellar bar ends near the IILR. Deviations from circular motion are detected just beyond the CO and H-alpha ring, where the dust lanes along the leading edge of the bar intersect the nuclear ring. These non-circular motions along the minor axis correspond to radially inward streaming motions at speeds of 20 - 90 km/s and clearly show inflowing gas feeding an ILR ring. There are bright HII regions near the ends of this inflow region, perhaps indicating triggering of star formation by the inflow.Comment: 25 pages, uses aasms.sty. 7 Postscript figures, 12 JPEG figures. Figures may be retrieved from ftp://clyde.as.utexas.edu/pub/N4314COfigs.tar.g

    Isolation, cohesion and contingent network effects: the case of school attachment and engagement

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    Isolation and cohesion are two key network features, often used to predict outcomes like mental health and deviance. More cohesive settings tend to have better outcomes, while isolates tend to fare worse than their more integrated peers. A common assumption of past work is that the effect of cohesion is universal, so that all actors get the same benefits of being in a socially cohesive environment. Here, we suggest that the effect of cohesion is universal only for specific types of outcomes. For other outcomes, experiencing the benefits of cohesion depends on an individual’s position in the network, such as whether or not an individual has any social ties. Network processes thus operate at both the individual and contextual level, and we employ hierarchical linear models to analyze these jointly to arrive at a full picture of how networks matter. We explore these ideas using the case of adolescents in schools (using Add Health data), focusing on the effect of isolation and cohesion on two outcomes, school attachment and academic engagement. We find that cohesion has a uniform effect in the case of engagement but not attachment. Only non-isolates experience stronger feelings of attachment as cohesion increases, while all students, both isolates and non-isolates, are more strongly engaged in high cohesion settings. Overall, the results show the importance of taking a systematic, multi-level approach, with important implications for studies of health and deviance

    Measurement of Gilbert damping parameters in nanoscale CPP-GMR spin-valves

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    In-situ, device level measurement of thermal mag-noise spectral linewidths in 60nm diameter CPP-GMR spin-valve stacks of IrMn/ref/Cu/free, with reference and free layer of similar CoFe/CoFeGe alloy, are used to simultaneously determine the intrinsic Gilbert damping for both magnetic layers. It is shown that careful alignment at a "magic-angle" between free and reference layer static equilibrium magnetization can allow direct measurement of the broadband intrinsic thermal spectra in the virtual absence of spin-torque effects which otherwise grossly distort the spectral line shapes and require linewidth extrapolations to zero current (which are nonetheless also shown to agree well with the direct method). The experimental magic-angle spectra are shown to be in good qualitative and quantitative agreement with both macrospin calculations and micromagnetic eigenmode analysis. Despite similar composition and thickness, it is repeatedly found that the IrMn exchange pinned reference layer has ten times larger intrinsic Gilbert damping (alpha ~ 0.1) than that of the free-layer (alpha ~ 0.01). It is argued that the large reference layer damping results from strong, off -resonant coupling to to lossy modes of an IrMn/ref couple, rather than commonly invoked two-magnon processes.Comment: 11 pages (2-column format), 12 figures. This work was presented at the 2010 Joint MMM-Intermag Conference (Washington, DC) as paper AB-01 (invited

    Sampling techniques for and interpretation of milk urea nitrogen concentration

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    Representative MUN values can be obtained by testing a milk sample before milking, at AM or PM milking, or with an in-line siphon sampling device. MUN values obtained from homogenous milking strings are as accurate as an average MUN value obtained by sampling each cow in the string. Bulk tank sampling is not advisable because of the variation in MUN caused by stage of lactation. Small herds that feed a single TMR should use the average MUN from cows between 60 and 200 days in milk. Monthly sampling is recommended to build a database. The effect of diet changes on MUN can be assessed within 7 days.; Dairy Day, 1998, Kansas State University, Manhattan, KS, 1998

    Kepler Presearch Data Conditioning II - A Bayesian Approach to Systematic Error Correction

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    With the unprecedented photometric precision of the Kepler Spacecraft, significant systematic and stochastic errors on transit signal levels are observable in the Kepler photometric data. These errors, which include discontinuities, outliers, systematic trends and other instrumental signatures, obscure astrophysical signals. The Presearch Data Conditioning (PDC) module of the Kepler data analysis pipeline tries to remove these errors while preserving planet transits and other astrophysically interesting signals. The completely new noise and stellar variability regime observed in Kepler data poses a significant problem to standard cotrending methods such as SYSREM and TFA. Variable stars are often of particular astrophysical interest so the preservation of their signals is of significant importance to the astrophysical community. We present a Bayesian Maximum A Posteriori (MAP) approach where a subset of highly correlated and quiet stars is used to generate a cotrending basis vector set which is in turn used to establish a range of "reasonable" robust fit parameters. These robust fit parameters are then used to generate a Bayesian Prior and a Bayesian Posterior Probability Distribution Function (PDF) which when maximized finds the best fit that simultaneously removes systematic effects while reducing the signal distortion and noise injection which commonly afflicts simple least-squares (LS) fitting. A numerical and empirical approach is taken where the Bayesian Prior PDFs are generated from fits to the light curve distributions themselves.Comment: 43 pages, 21 figures, Submitted for publication in PASP. Also see companion paper "Kepler Presearch Data Conditioning I - Architecture and Algorithms for Error Correction in Kepler Light Curves" by Martin C. Stumpe, et a

    Creation and implementation of an emergency medicine education and training program in Turkey: An effective educational intervention to address the practitioner gap

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    Background The specialty of Emergency Medicine has enjoyed recognition for nearly 20 years in Turkey. However, the majority of underserved and rural Turkish emergency departments are staffed by general practitioners who lack formal training in the specialty and have few opportunities to increase emergency medicine-specific knowledge and skills. Methods To address this “practitioner gap,” the authors developed a four-phase comprehensive emergency medicine education and training program for general practitioners practicing in government hospitals in Turkey. Results From April 2006 until June 2009, 42 courses were taught by 62 trainers across seven regions in Turkey. A total of 2,262 physicians were trained. The mean course pre-test score for all regions was 42.3 (95% CI 39.8 to 44.7). The mean course post-test score was 70.1 (95% CI 67.2 to 72.9). The difference between the mean scores was 27.8 (95% CI 25.3 to 30.4, P \u3c0.0001), reflecting an improvement of 65.7%. Conclusions A partnership between an academic emergency medicine department and an emergency medicine society to implement country-wide training of physicians practicing in public emergency departments can serve as a successful model for capacity-building global emergency medicine endeavors
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