735 research outputs found

    Convective Vortices on Mars: A Reanalysis of Viking Lander 2 Meteorological Data, Sols 1-50

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    On 7th August 1976 the Viking 2 lander touched down at Utopia Planitia, Mars. We have reanalysed Viking lander 2 meteorological data, and it is the object of this research to give not only annual but diurnal statistics of convective vortex formation for the Viking 2 landing site

    Natural resources of the Barron River catchment 1: stream habitat, fisheries resources and biological indicators

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    The Barron River drains into the Coral Sea, near Cairns, Queensland (Australia) and in comparison to other Queensland wet tropics streams, it has a relatively large catchment area of about 219,000 ha. The catchment has high fish diversity, with at least 209 estuarine and freshwater species and the Barron River Estuary is a spawning and nursery ground for a variety of fish and prawn species and supports a wide range of commercial and recreational fish species. The variance and abundance of benthic macroinvertebrates can provide valuable information on the ecological condition of a river system. Overall, the macroinvertebrate populations indicated a relatively healthy system although nutrient enrichment may be causing degradation. Reserves such as existing Fish Habitat Areas and a proposed marine park will provide ongoing protection for coastal wetlands. A series of potential management issues for the catchment and future monitoring strategies are discussed

    The effects of an experimental programme to support students’ autonomy on the overt behaviours of physical education teachers

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    Although the benefits of autonomy supportive behaviours are now well established in the literature, very few studies have attempted to train teachers to offer a greater autonomy support to their students. In fact, none of these studies has been carried out in physical education (PE). The purpose of this study is to test the effects of an autonomy-supportive training on overt behaviours of teaching among PE teachers. The experimental group included two PE teachers who were first educated on the benefits of an autonomy supportive style and then followed an individualised guidance programme during the 8 lessons of a teaching cycle. Their behaviours were observed and rated along 3 categories (i.e., autonomy supportive, neutral and controlling) and were subsequently compared to those of three teachers who formed the control condition. The results showed that teachers in the experimental group used more autonomy supportive and neutral behaviours than those in the control group, but no difference emerged in relation to controlling behaviours. We discuss the implications for schools of our findings

    Reflections on the Centenary of Sir William Osler: Science and Humanity are One, for Nursing and Medicine

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    Sir William Osler (1849-1991) was Regius Professor of Medicine at the University of Oxford in the UK and a founding professor at Johns Hopkins Hospital. The centenary of Osler’s death is a time for recognition in nursing, as well as medicine, of a pioneering and highly influential Oxford physician on both sides of the Atlantic, an influence that extended to nursing from the UK to the USA. This letter captures reflections and discussion on contemporary nursing issues from an Osler Seminar Series, held at the University of Oxford in 2019 to mark the Centenary of Sir William Osler’s death, focusing on his thinking and influence related to nursing. This extended letter illuminates issues on themes of science and humanity within a clinical and educational context, exploring a range of key contemporary nursing issues. These include the significance of interpersonal relations as they relate to care attitude and care technology; the therapeutic influence of the nurse; nursing education and clinical-academic development; the value of a life world perspective on nursing and wellbeing; and practice development within the context of person-centred workplace cultures. These issues are contextualised with examples from practice and include some from nursing developments and those illustrated in part by the clinical speciality of dermatological care. The letter concludes by considering the significance of the nursing service to promoting access to quality health care in the twenty-first century and its relevance to recognising the nursing contribution to universal health care through the WHO International Year(s) of the Nurse and Midwife in 2020-21

    Counter-stereotypical messaging and partisan cues: Moving the needle on vaccines in a polarized United States

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    This paper reports results from a large-scale randomized controlled trial assessing whether counter-stereotypical messaging and partisan cues can induce people to get COVID-19 vaccines. The study used a 27-s video compilation of Donald Trump's comments about the vaccine from Fox News interviews and presented the video to millions of U.S. YouTube users through a $100,000 advertising campaign in October 2021. Results indicate that the number of vaccines increased in the average treated county by 103 (with a one-tailed P value of 0.097). Based on this average treatment effect and totaling across our 1014 treated counties, the total estimated effect was 104,036 vaccines

    United classification of cosmic gamma-ray bursts and their counterparts

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    United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events consists in that, as the energy increases, the duration decreases (and vice versa). The given interrelation reflects the nature of the phenomenon and forms the E-T diagram, which represents a natural classification of all observed events in the energy range from 10E9 to 10E-6 eV and in the corresponding interval of durations from about 10E-2 up to 10E8 s. The proposed classification results in the consequences, which are principal for the theory and practical study of the phenomenon.Comment: Keywords Gamma rays: burst

    Solution and Solid-State Behavior of Amphiphilic ABA Triblock Copolymers of Poly(acrylic acid-stat-styrene)-block-poly(butyl acrylate)-block-poly(acrylic acid-stat-styrene)

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    A combination of statistical and triblock copolymer properties is explored to produce stable aqueous polymer dispersions suitable for the film formation. In order to perform an extensive structural characterization of the products in the dissolved, dispersed, and solid states, a wide range of symmetrical poly(acrylic acid-stat-styrene)x-block-poly(butyl acrylate)y-block-poly(acrylic acid-stat-styrene)x, poly(AA-st-St)x-b-PBAy-b-poly(AA-st-St)x, (x = 56, 108 and 140, y = 100–750; the AA:St molar ratio is 42:58) triblock copolymers were synthesized by reversible addition–fragmentation chain transfer (RAFT) solution polymerization using a bifunctional symmetrical RAFT agent. It is demonstrated that the amphiphilic statistical outer blocks can provide sufficient stabilization to largely hydrophobic particles in aqueous dispersions. Such a molecular design provides an advantage over copolymers composed only of homoblocks, as a simple variation of the statistical block component ratio provides an efficient way to control the hydrophilicity of the stabilizer block, which ultimately affects the copolymer morphology in solutions and solid films. It was found by small-angle X-ray scattering (SAXS) that the copolymers behaved as dissolved chains in methylethylketone (MEK) but self-assembled in water into stable and well-defined spherical particles that increased in size with the length of the hydrophobic PBA block. These particles possessed an additional particulate surface structure formed by the statistical copolymer stabilizer block, which self-folded through the hydrophobic interactions between the styrene units. SAXS and atomic force microscopy showed that the copolymer films cast from the MEK solutions formed structures predicted by self-consistent field theory for symmetrical triblock copolymers, while the aqueous dispersions formed structural morphologies similar to a close-packed spheres, as would be expected for copolymer particles trapped kinetically due to the restricted movement of the blocks in the initial aqueous dispersion. A strong correlation between the structural morphology and mechanical properties of the films was observed. It was found that the properties of the solvent cast films were highly dependent on the ratios of the hard [poly(AA-st-St)] and soft (PBA) blocks, while the aqueous cast films did not show such a dependence. The continuous phase of hard blocks, always formed in the case of the aqueous cast films, produced films with a higher elastic modulus and a lower extension-to-break in a comparison with the solvent-cast films

    Milagrito: a TeV air-shower array

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    Milagrito, a large, covered water-Cherenkov detector, was the world's first air-shower-particle detector sensitive to cosmic gamma rays below 1 TeV. It served as a prototype for the Milagro detector and operated from February 1997 to May 1998. This paper gives a description of Milagrito, a summary of the operating experience, and early results that demonstrate the capabilities of this technique.Comment: 38 pages including 24 figure
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