9,769 research outputs found

    Actic Law & Policy Year in Review: 2015

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    A review of significant legal developments affecting the Arctic, including treaties and other international agreements; actions by the U.S. Congress, President, and other federal agencies; developments from the European Union and ten foreign countries; and several international organizations. Also addressed are themes including arctic marine shipping; indigneous residents; marine resources; military activities; polar icebreakers; pollution prevention, response, and liability; and scientific research

    Resolving the Surfaces of Extrasolar Planets With Secondary Eclipse Light Curves

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    We present a method that employs the secondary eclipse light curves of transiting extrasolar planets to probe the spatial variation of their thermal emission. This technique permits an observer to resolve the surface of the planet without the need to spatially resolve its central star. We evaluate the feasibility of this technique for the HD 209458 system [..]. We consider two representations of the planetary thermal emission; a simple model parameterized by a sinusoidal dependence on longitude and latitude, as well as the results of a three-dimensional dynamical simulation of the planetary atmosphere previously published by Cooper & Showman. We find that observations of the secondary eclipse light curve are most sensitive to a longitudinal offset in the geometric and photometric centroids of the hemisphere of the planet visible near opposition. To quantify this signal, we define a new parameter, the ``uniform time offset,'' which measures the time lag between the observed secondary eclipse and that predicted by a planet with a uniform surface flux distribution. We compare the predicted amplitude of this parameter for HD 209458 with the precision with which it could be measured with IRAC. We find that IRAC observations at 3.6um a single secondary eclipse should permit sufficient precision to confirm or reject the Cooper & Showman model of the surface flux distribution for this planet. We quantify the signal-to-noise ratio for this offset in the remaining IRAC bands (4.5um, 5.8um, and 8.0um), and find that a modest improvement in photometric precision (as might be realized through observations of several eclipse events) should permit a similarly robust detection.Comment: AASTeX 5.2, 24 pages, 5 figures, accepted for publication in ApJ; v2: clarifications, updated to version accepted by ApJ; v3: try to reduce spacin

    Personality, Parenting Style, and Academic Cognitions: The Effects of Authoritarian Parenting Style on Personality Traits and Behaviors

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    Presented is an analysis of self-esteem as a moderator of the effect authoritarian parenting on personality trait and behavior development

    Direct health costs of inflammatory polyarthritis 10 years after disease onset:Results from the Norfolk Arthritis Register

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    Objectives: To explore the change in direct medical costs associated with inflammatory polyarthritis (IP) 10 to 15 years after its onset. Methods: Patients from the Norfolk Arthritis Register who had previously participated in a health economic study in 1999 were traced 10 years later and invited to participate in a further prospective questionnaire-based study. The study was designed to identify direct medical costs and changes in health status over a 6-month period using previously validated questionnaires as the primary source of data. Results: A representative sample of 101 patients with IP from the 1999 cohort provided complete data over the 6-month period. The mean disease duration was 14 years (SD 2.1, median 13.6, interquartile range 12.6–15.4). The mean direct medical cost per patient over the 6-month period was £1496 for IP (inflated for 2013 prices). This compared with £582 (95% CI £355–£964) inflated to 2013 prices per patient with IP 10 years earlier in their disease. The increased cost was largely associated with the use of biologics in the rheumatoid arthritis subgroup of patients (51% of total costs incurred). Other direct cost components included primary care costs (11%), hospital outpatient (19%), day care (12%), and inpatient stay (4%). Conclusion: The direct healthcare costs associated with IP have more than doubled with increasing disease duration, largely as a result of the use of biologics. The results showed a shift in the direct health costs from inpatient to outpatient service use

    Measuring atomic NOON-states and using them to make precision measurements

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    A scheme for creating NOON-states of the quasi-momentum of ultra-cold atoms has recently been proposed [New J. Phys. 8, 180 (2006)]. This was achieved by trapping the atoms in an optical lattice in a ring configuration and rotating the potential at a rate equal to half a quantum of angular momentum . In this paper we present a scheme for confirming that a NOON-state has indeed been created. This is achieved by spectroscopically mapping out the anti-crossing between the ground and first excited levels by modulating the rate at which the potential is rotated. Finally we show how the NOON-state can be used to make precision measurements of rotation.Comment: 14 preprint pages, 7 figure

    On the controlled electrochemical preparation of R4N+ graphite intercalation compounds and their host structural deformation effects

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    AbstractWe present electrochemical studies of tetraalkylammonium (R4N+) reduction chemistry at Highly Orientated Pyrolytic Graphite (HOPG) and glassy carbon (GC) electrodes. We show that by electrochemically controlled intercalation and formation of a graphite intercalation complex (GIC) into layered HOPG, the irreversible reduction of the tetraalkylammonium cation can be prevented and subsequent de-intercalation of the GIC via the use of potentiostatic control is achievable. R4N+ cations with varying alkyl chain lengths (methyl, ethyl and butyl) have been shown to exhibit excellent charge recovery effects during charge/discharge studies. Finally the effects of electrode expansion on the degree of recovered charge have been investigated and the observed effects of R4N+ intercalation on the graphite cathode have been probed by scanning electron microscopy (SEM) and X-ray diffraction (XRD)

    Accelerated Calvarial Healing in Mice Lacking Toll-Like Receptor 4

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    The bone and immune systems are closely interconnected. The immediate inflammatory response after fracture is known to trigger a healing cascade which plays an important role in bone repair. Toll-like receptor 4 (TLR4) is a member of a highly conserved receptor family and is a critical activator of the innate immune response after tissue injury. TLR4 signaling has been shown to regulate the systemic inflammatory response induced by exposed bone components during long-bone fracture. Here we tested the hypothesis that TLR4 activation affects the healing of calvarial defects. A 1.8 mm diameter calvarial defect was created in wild-type (WT) and TLR4 knockout (TLR4-/-) mice. Bone healing was tested using radiographic, histologic and gene expression analyses. Radiographic and histomorphometric analyses revealed that calvarial healing was accelerated in TLR4-/- mice. More bone was observed in TLR4-/- mice compared to WT mice at postoperative days 7 and 14, although comparable healing was achieved in both groups by day 21. Bone remodeling was detected in both groups on postoperative day 28. In TLR4-/- mice compared to WT mice, gene expression analysis revealed that higher expression levels of IL-1β, IL-6, TNF-α,TGF-β1, TGF-β3, PDGF and RANKL and lower expression level of RANK were detected at earlier time points (≤ postoperative 4 days); while higher expression levels of IL-1β and lower expression levels of VEGF, RANK, RANKL and OPG were detected at late time points (> postoperative 4 days). This study provides evidence of accelerated bone healing in TLR4-/- mice with earlier and higher expression of inflammatory cytokines and with increased osteoclastic activity. Further work is required to determine if this is due to inflammation driven by TLR4 activation. © 2012 Wang et al

    A map of the day-night contrast of the extrasolar planet HD 189733b

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    "Hot Jupiter" extrasolar planets are expected to be tidally locked because they are close (<0.05 astronomical units, where 1 AU is the average Sun-Earth distance) to their parent stars, resulting in permanent daysides and nightsides. By observing systems where the planet and star periodically eclipse each other, several groups have been able to estimate the temperatures of the daysides of these planets. A key question is whether the atmosphere is able to transport the energy incident upon the dayside to the nightside, which will determine the temperature at different points on the planet's surface. Here we report observations of HD 189733, the closest of these eclipsing planetary systems, over half an orbital period, from which we can construct a 'map' of the distribution of temperatures. We detected the increase in brightness as the dayside of the planet rotated into view. We estimate a minimum brightness temperature of 973 +/- 33 K and a maximum brightness temperature of 1212 +/- 11 K at a wavelength of 8 microns, indicating that energy from the irradiated dayside is efficiently redistributed throughout the atmosphere, in contrast to a recent claim for another hot Jupiter. Our data indicate that the peak hemisphere-integrated brightness occurs 16±\pm6 degrees before opposition, corresponding to a hot spot shifted east of the substellar point. The secondary eclipse (when the planet moves behind the star) occurs 120 +/- 24 s later than predicted, which may indicate a slightly eccentric orbit.Comment: To appear in the May 10 2007 issue of Nature, 10 pages, 2 black and white figures, 1 colo

    Natural fracture patterns at Swift Reservoir anticline, NW Montana : the influence of structural position and lithology from multiple observation scales

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    Acknowledgements We gratefully acknowledge constructive reviews by Amerigo Corradetti and an anonymous reviewer and thank Stefano Tavani for editorial handling. Adam J. Cawood is grateful to David Ferrill, Kevin Smart, and Paul Gillespie for helpful conversations about fracture patterns, although the data and interpretations shown here are of course the sole responsibility of the authors. This study was carried out as part of a University of Aberdeen doctoral programme supported by the Natural Environment Research Council (NERC) Centre for Doctoral Training in Oil and Gas. Additional funding for fieldwork was provided by the University of Aberdeen Fold–Thrust Research Group. Petroleum Experts (formerly Midland Valley Exploration) is acknowledged for allowing the academic use of Move 2016.1 software. Financial support This research has been supported by the Natural Environment Research Council (grant no. NE/M00578X/1).Peer reviewedPublisher PD

    Fracture distribution on the Swift Reservoir Anticline, Montana : implications for structural and lithological controls on fracture intensity

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    Title of special publication: Folding and Fracturing of Rocks: 50 Years of Research since the Seminal Text Book of J. G. Ramsay This research was funded by Oil Search Ltd, Santos Ltd and InterOil, through the University of Aberdeen Fold-Thrust Research Group. Electron Microscopy was performed in the ACEMAC Facility at the University of Aberdeen with assistance from John Still. Joyce Neilson is thanked for advice on the use of ImageJ software. Midland Valley are thanked for the use of their Move software for field data collection and model building. We thank Alfred Lacazette and Stefano Tavani for reviewing the manuscript and providing constructive comments.Peer reviewedPostprin
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