675 research outputs found

    Youths and Communities: Toward Comprehensive Strategies for Youth Development

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    Society\u27s conventional response to problems of young people such as teenage pregnancy, school dropout, substance abuse, juvenile delinquency, and violence -- is to target a specific problem and develop intervention or prevention programs for individuals who manifest the problem or are at high risk of it. Research shows that overlapping risk and protective factors affect the occurrence of all of these problems and that prevention strategies aimed at enhancing youths\u27 development, reducing communities specific risks, and strengthening protective factors are likely to be more successful than programs addressing the problem behaviors themselves. Among such strategies deserving wider consideration are comprehensive community initiatives that create collaborative partnerships among public officials, service providers, primary institutions, and citizens to promote the well-being of children, youths, and families

    Distribution of calling blue, fin, and humpback whales in the North Pacific

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    May also be cited as: WHOI-00-12The seasonal distribution of calling ble whales (Balaenoptera musculus), fin whales (B. physalus), and singing humpback whales (Megaptera novaeangliae) has been analyzed from acoustic data recorded by the U.S. Navy Sound Surveillance System (SOSUS) and other hydrophone arrays in the North Pacific. The data from ten arrays were selected as representative of four Regions along the continental margins, labeled Northwest (NW), NorthCentral (NC), Northeast (NE), and Southeast (SE). The call data indicate that there is a substantial population of blue whales scattered over the North Pacific and concentrated during the Fall season in the NW and NC Regions. Blue whale calls are recorded in all seasons, particularly in these NW and NC Regions. Fin whales are found in groups but also in relatively large numbers in all Regions, with most calling in the Winter season and in the NC Region, while calling is absent in most Regions during Summer. Fin whale calling includes "F" calls from individuals heard in all seasons and "J" calls from too many whales to separate, particularly prominent in the winter reproductive season. Humpback singing is recorded most in the both the NC and SE Regions between the 1996-1997 and 1998-2000 periods.Funding was provided by the Office of Naval Research under Contract No. N00014-96-1-1130 CNO-N45 Environmental Program and U.S. Army Corps of Engineers (DCA87-00/H-0026) with funds from the Department of Defense Legacy Reseource Management Program

    Searching for Planets in the Hyades. I. The Keck Radial Velocity Survey

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    We describe a high-precision radial velocity search for jovian-mass companions to main sequence stars in the Hyades star cluster. The Hyades provides an extremely well controlled sample of stars of the same age, the same metallicity, and a common birth and early dynamical environment. This sample allows us to explore the dependence of the process of planet formation on only a single independent variable: the stellar mass. In this paper we describe the survey and summarize results for the first five years.Comment: 8 pages, 3 figures; To appear in the July 2002 issue of The Astronomical Journa

    Implementation of a reference standard and proficiency testing programme by the World Wide Antimalarial Resistance Network (WWARN)

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    <p>Abstract</p> <p>Background</p> <p>The Worldwide Antimalarial Resistance Network (WWARN) is a global collaboration to support the objective that anyone affected by malaria receives effective and safe drug treatment. The Pharmacology module aims to inform optimal anti-malarial drug selection. There is an urgent need to define the drug exposure - effect relationship for most anti-malarial drugs. Few anti-malarials have had their therapeutic blood concentration levels defined. One of the main challenges in assessing safety and efficacy data in relation to drug concentrations is the comparability of data generated from different laboratories. To explain differences in anti-malarial pharmacokinetics in studies with different measurement laboratories it is necessary to confirm the accuracy of the assay methods. This requires the establishment of an external quality assurance process to assure results that can be compared. This paper describes this process.</p> <p>Methods</p> <p>The pharmacology module of WWARN has established a quality assurance/quality control (QA/QC) programme consisting of two separate components:</p> <p indent="1">1. A proficiency testing programme where blank human plasma spiked with certified reference material (CRM) in different concentrations is sent out to participating bioanalytical laboratories.</p> <p indent="1">2. A certified reference standard programme where accurately weighed amounts of certified anti-malarial reference standards, metabolites, and internal standards are sent to participating bioanalytical and in vitro laboratories.</p> <p>Conclusion</p> <p>The proficiency testing programme is designed as a cooperative effort to help participating laboratories assess their ability to carry out drug analysis, resolve any potential problem areas and to improve their results - and, in so doing, to improve the quality of anti-malarial pharmacokinetic data published and shared with WWARN.</p> <p>By utilizing the same source of standards for all laboratories, it is possible to minimize bias arising from poor quality reference standards. By providing anti-malarial drug standards from a central point, it is possible to lower the cost of these standards.</p

    Whale call data for the North Pacific : November 1995 through July 1999 occurrence of calling whales and source locations from SOSUS and other acoustic systems

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    May also be cited as: WHOI-00-02Calls of blue whales (Balaenoptera musculus), fin whales (Balaenoptera physalus), and humpback whales (Megaptera novaeangliae) were identified in the data from U.S. Navy Sound Surveilance System (SOSUS) and other hydrophone arrays. These data on calling whales from November 1995 through July 1999 have been listed here for four offshore, deep-water Regions along continental margins of the North and Northeast Pacific. The occurrence of calling whales was monitored during two-day periods each week. Call data recorded from each array identified species, call occurrence, variation, received beam, and relative numbers of calling whales. This allowed assessment of seasonal distribution of calls for the different species, and provided locations for sources received at multiple arrays. Blue whale tonal sounds were distributed widely, received most in the NW Region, with a peak in occurrence in the fall. Fin whale "20-Hz" repetitive pulse sequences were received from whales grouped in local areas in all Regions, with a peak in occurrence in midwinter. Humpback songs were received from December through May particularly in the SE Region. The offshore listening systems allowed basin-wide monitoring of the seasonal distribution of these callng whales.Funding was provided by the Office Naval Research under Grant No. N00014-96-1-1130, SERDP and CNO N45

    SWIR Emissive RosIndolizine Dyes With Nanoencapsulation In Water Soluble Dendrimers

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    Shortwave infrared (SWIR) emission has great potential for deep-tissue in vivo biological imaging with high resolution. In this article, the synthesis and characterization of two new xanthene-based RosIndolizine dyes coded PhRosIndz and tolRosIndz is presented. The dyes are characterized via femtosecond transient absorption spectroscopy as well as steady-state absorption and emission spectroscopies. The emission of these dyes is shown in the SWIR region with peak emission at 1097 nm. TolRosIndz was encapsulated with an amphiphilic linear dendritic block co-polymer (LDBC) coded 10-PhPCL-G3 with high uptake yield. Further, cellular toxicity was examined in vitro using HEK (human embryonic kidney) cells where a \u3e90% cell viability was observed at practical concentrations of the encapsulated dye which indicates low toxicity and reasonable biocompatibility

    Determining the Cosmic Distance Scale from Interferometric Measurements of the Sunyaev-Zel'dovich Effect

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    We determine the distances to 18 galaxy clusters with redshifts ranging from z~0.14 to z~0.78 from a maximum likelihood joint analysis of 30 GHz interferometric Sunyaev-Zel'dovich effect (SZE) and X-ray observations. We model the intracluster medium (ICM) using a spherical isothermal beta model. We quantify the statistical and systematic uncertainties inherent to these direct distance measurements, and we determine constraints on the Hubble parameter for three different cosmologies. These distances imply a Hubble constant of 60 (+4, -4) (+13, -18) km s-1 Mpc-1 for an Omega_M = 0.3, Omega_Lambda = 0.7 cosmology, where the uncertainties correspond to statistical followed by systematic at 68% confidence. With a sample of 18 clusters, systematic uncertainties clearly dominate. The systematics are observationally approachable and will be addressed in the coming years through the current generation of X-ray satellites (Chandra & XMM-Newton) and radio observatories (OVRO, BIMA, & VLA). Analysis of high redshift clusters detected in future SZE and X-ray surveys will allow a determination of the geometry of the universe from SZE determined distances.Comment: ApJ Submitted; 40 pages, 9 figures (fig 3 B&W for size constraint), 13 tables, uses emulateapj5 styl
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