551 research outputs found

    An NSTA Position Statement: Science-Technology-Society: Science Education for the 1980s

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    Science and technology influence every aspect of our lives. They are central to our welfare as individuals and to the welfare of our society. All around us are examples of the importance of science and technology for production of food, shelter, clothing, medicines, transportation, and various sources of energy. There are an increasing number of science- and technology-related societal problems as well as increasing societal benefits. Science and technology are central to our personal and cultural welfare and to many societal problems. We must insure appropriate science education for all citizens

    SNAKE: The Plain and Its People

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    Idaho\u27s longest river curves west through desert landscapes, cutting deep through ancient formations, flowing through space and time. How have humans dealt with the desert? How have we been shaped by the land? SNAKE: The Plain and Its People explores the physical and ecological roots of Idaho civilization through science, social science, photography and art.https://scholarworks.boisestate.edu/fac_books/1371/thumbnail.jp

    Joint Polar Satellite System (JPSS) Micrometeoroid and Orbital Debris (MMOD) Assessment

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    The Joint Polar Satellite System (JPSS) Project requested the NASA Engineering and Safety Center (NESC) conduct an independent evaluation of the Micrometeoroid and Orbital Debris (MMOD) models used in the latest JPSS MMOD risk assessment. The principal focus of the assessment was to compare Orbital Debris Engineering Model version 3 (ORDEM 3.0) with the Meteoroid and Space Debris Terrestrial Environment Reference version 2009 (MASTER-2009) and Aerospace Debris Environment Projection Tool (ADEPT) and provide recommendations to the JPSS Project regarding MMOD protection. The outcome of the NESC assessment is contained in this report

    Tracking a Medically Important Spider: Climate Change, Ecological Niche Modeling, and the Brown Recluse (Loxosceles reclusa)

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    Most spiders use venom to paralyze their prey and are commonly feared for their potential to cause injury to humans. In North America, one species in particular, Loxosceles reclusa (brown recluse spider, Sicariidae), causes the majority of necrotic wounds induced by the Araneae. However, its distributional limitations are poorly understood and, as a result, medical professionals routinely misdiagnose brown recluse bites outside endemic areas, confusing putative spider bites for other serious conditions. To address the issue of brown recluse distribution, we employ ecological niche modeling to investigate the present and future distributional potential of this species. We delineate range boundaries and demonstrate that under future climate change scenarios, the spider's distribution may expand northward, invading previously unaffected regions of the USA. At present, the spider's range is centered in the USA, from Kansas east to Kentucky and from southern Iowa south to Louisiana. Newly influenced areas may include parts of Nebraska, Minnesota, Wisconsin, Michigan, South Dakota, Ohio, and Pennsylvania. These results illustrate a potential negative consequence of climate change on humans and will aid medical professionals in proper bite identification/treatment, potentially reducing bite misdiagnoses

    Application of a low cost array-based technique — TAB-Array — for quantifying and mapping both 5mC and 5hmC at single base resolution in human pluripotent stem cells

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    Abstract5-hydroxymethylcytosine (5hmC), an oxidized derivative of 5-methylcytosine (5mC), has been implicated as an important epigenetic regulator of mammalian development. Current procedures use DNA sequencing methods to discriminate 5hmC from 5mC, limiting their accessibility to the scientific community. Here we report a method that combines TET-assisted bisulfite conversion with Illumina 450K DNA methylation arrays for a low-cost high-throughput approach that distinguishes 5hmC and 5mC signals at base resolution. Implementing this approach, termed “TAB-array”, we assessed DNA methylation dynamics in the differentiation of human pluripotent stem cells into cardiovascular progenitors and neural precursor cells. With the ability to discriminate 5mC and 5hmC, we identified a large number of novel dynamically methylated genomic regions that are implicated in the development of these lineages. The increased resolution and accuracy afforded by this approach provides a powerful means to investigate the distinct contributions of 5mC and 5hmC in human development and disease

    Possible Detection of Low Energy Solar Neutrons Using Boron Based Materials

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    Solar neutrons have been detected aboard the International Space Station (ISS), using lithium tetraborate and boron carbide detector elements. We find that evidence of a solar neutron flux, as detected in a neutron calorimeter following subtraction of the proton background, with an energy of about 2 to 4 MeV. This solar neutron flux is likely no more than 250 to 375 neutrons cm−2sec−1, with a lower bound of 50–75 neutrons cm−2sec−1 at one au

    Observation of Two Narrow States Decaying into Ξc+γ\Xi_{c}^{+}\gamma and Ξc0γ\Xi_{c}^{0}\gamma

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    We report the first observation of two narrow charmed strange baryons decaying to Ξc+γ\Xi_c^+\gamma and Ξc0γ\Xi_c^0\gamma, respectively, using data from the CLEO II detector at CESR. We interpret the observed signals as the Ξc+(csu)\Xi_c^{+\prime}(c{su}) and Ξc0(csd)\Xi_c^{0\prime}(c{sd}), the symmetric partners of the well-established antisymmetric Ξc+(c[su])\Xi_c^+(c[su]) and Ξc0(c[sd])\Xi_c^0(c[sd]). The mass differences M(Ξc+)M(Ξc+)M(\Xi_c^{+\prime})-M(\Xi_c^+) and M(Ξc0)M(Ξc0)M(\Xi_c^{0\prime})-M(\Xi_c^0) are measured to be 107.8±1.7±2.5107.8\pm 1.7\pm 2.5 and 107.0±1.4±2.5MeV/c2107.0\pm 1.4\pm 2.5 MeV/c^2, respectively.Comment: 11 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Revealing important nocturnal and day-to-day variations in fire smoke emissions through a multiplatform inversion

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    We couple airborne, ground-based, and satellite observations; conduct regional simulations; and develop and apply an inversion technique to constrain hourly smoke emissions from the Rim Fire, the third largest observed in California, USA. Emissions constrainedwithmultiplatform data show notable nocturnal enhancements (sometimes over a factor of 20), correlate better with daily burned area data, and are a factor of 2–4 higher than a priori estimates, highlighting the need for improved characterization of diurnal profiles and day-to-day variability when modeling extreme fires. Constraining only with satellite data results in smaller enhancements mainly due to missing retrievals near the emissions source, suggesting that top-down emission estimates for these events could be underestimated and a multi-platform approach is required to resolve them. Predictions driven by emissions constrained with multi-platform data present significant variations in downwind air quality and in aerosol feedback on meteorology, emphasizing the need for improved emissions estimates during exceptional events

    A Measurement of the Decay Asymmetry Parameters in \Xi_{c}^{0}\to \X^{-}\pi^{+}

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    Using the CLEO II detector at the Cornell Electron Storage Ring we have measured the Ξc0\Xi_c^{0} decay asymmetry parameter in the decay Ξc0Ξπ+\Xi_c^{0} \to \Xi^{-} \pi^+. We find αΞc0αΞ=0.26±0.18(stat)0.04+0.05(syst)\alpha_{\Xi_c^{0}} \alpha_{\Xi} = 0.26 \pm 0.18{(stat)}^{+0.05}_{-0.04}{(syst)}, using the world average value of αΞ=0.456±0.014\alpha_{\Xi} = -0.456 \pm 0.014 we obtain αΞc0=0.56±0.39(stat)0.09+0.10(syst)\alpha_{\Xi_c^{0}} = -0.56 \pm 0.39{(stat)}^{+0.10}_{-0.09}{(syst)}. The physically allowed range of a decay asymmetry parameter is 1<α<+1-1<\alpha<+1. Our result prefers a negative value: αΞc0\alpha_{\Xi_c^{0}} is <0.1<0.1 at the 90% CL. The central value occupies the middle of the theoretically expected range but is not yet precise enough to choose between models.Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN
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