309 research outputs found

    LocaRDS: A Localization Reference Data Set

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    The use of wireless signals for the purposes of localization enables a host of applications relating to the determination and verification of the positions of network participants ranging from radar to satellite navigation. Consequently, this has been a longstanding interest of theoretical and practical research in mobile networks and many solutions have been proposed in the scientific literature. However, it is hard to assess the performance of these in the real world and, more importantly, to compare their advantages and disadvantages in a controlled scientific manner. With this work, we attempt to improve the current state of art methodology in localization research and to place it on a solid scientific grounding for future investigations. Concretely, we developed LocaRDS, an open reference data set of real-world crowdsourced flight data featuring more than 222 million measurements from over 50 million transmissions recorded by 323 sensors. We demonstrate how we can verify the quality of LocaRDS measurements so that it can be used to test, analyze and directly compare different localization methods. Finally, we provide an example implementation for the aircraft localization problem and a discussion of possible metrics for use with LocaRDS

    Potash Studies on Burley Tobacco in Owen County, Kentucky

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    Since the late 1970\u27s, farmers in the Wheatley Community of Owen county have reported seeing potassium (K) deficiency on tobacco during the growing season. Most of them had been following University of Kentucky fertilizer recommendations for burley production. Analyses of cured leaf samples from one such crop in 1980 confirmed K deficiency. It was decided that the problem warranted conducting some field experiments in order to define the problem and hopefully develop a solution. Consequently, we located a field on the Harold Malcomb farm near Wheatly, that tested low in soil K and designed a field experiment with the objectives of (1) testing the effectiveness of UK soil test recommendations for potash, (2) testing K rates applied pre-plant, sidedressed, and in combination, and (3) since soil Zinc (Zn) levels were low, we also decided to test for a tobacco yield response to fertilizer Zn. Subsequently, K studies were conducted in different fields of the Malcomb farm during 1981, 1984, 1985, 1986, and i987, and in a field on the Steve Simpson farm near New Columbus in 1986. The following report summarizes what we learned

    Reanalysis of two eclipsing binaries: EE Aqr and Z Vul

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    We study the radial-velocity and light curves of the two eclipsing binaries EE Aqr and Z Vul. Using the latest version of the Wilson & Van Hamme (2003) model, absolute parameters for the systems are determined. We find that EE Aqr and Z Vul are near-contact and semi-detached systems, respectively. The primary component of EE Aqr fills about 96% of its 'Roche lobe', while its secondary one appears close to completely filling this limiting volume. In a similar way, we find fill-out proportions of about 72 and 100% of these volumes for the primary and secondary components of Z Vul respectively. We compare our results with those of previous authors.Comment: 13 pages, 8 figures, 10 table

    Four-colour photometry of eclipsing binaries. XLI uvby light curves for AD Bootis, HW Canis Majoris, SW Canis Majoris, V636 Centauri, VZ Hydrae, and WZ Ophiuchi

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    CONTEXT: Accurate mass, radius, and abundance determinations from binaries provide important information on stellar evolution, fundamental to central fields in modern astrophysics and cosmology. AIMS: Within the long-term Copenhagen Binary Project, we aim to obtain high-quality light curves and standard photometry for double-lined detached eclipsing binaries with late A, F, and G type main-sequence components, needed for the determination of accurate absolute dimensions and abundances, and for detailed comparisons with results from recent stellar evolutionary models. METHODS: Between March 1985 and July 2007, we carried out photometric observations of AD Boo, HW CMA, SW CMa, V636 Cen, VZ Hya, and WZ Oph at the Str"omgren Automatic Telescope at ESO, La Silla. RESULTS: We obtained complete uvby light curves, ephemerides, and standard uvby\beta indices for all six systems.For V636 Cen and HW CMa, we present the first modern light curves, whereas for AD Boo, SW CMa, VZ Hya, and WZ Oph, they are both more accurate and more complete than earlier data. Due to a high orbital eccentricity (e = 0.50), combined with a low orbital inclination (i = 84.7), only one eclipse, close to periastron, occurs for HW CMa. For the two other eccentric systems, V636 Cen (e = 0.134) and SW CMa (e = 0.316), apsidal motion has been detected with periods of 5270 +/- 335 and 14900 +/- 3600 years, respectively.Comment: Only change is: Bottom lines (hopefully) not truncated anymore. Accepted for publication in Astonomy & Astrophysic

    Bayesian approach to cyclic activity of CF Oct

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    Bayesian statistical methods of Gregory-Loredo and the Bretthorst generalization of the Lomb-Scargle periodogram have been applied for studying activity cycles of the early K-type subgiant star CF Oct. We have used a ~45 year long dataset derived from archival photographic observations, published photoelectric photometry, Hipparcos data series and All Sky Automated Survey archive. We have confirmed the already known rotational period for the star of 20.16 d and have shown evidences that it has exhibited changes from 19.90 d to 20.45 d. This is an indication for stellar surface differential rotation.The Bayesian magnitude and time--residual analysis reveals clearly at least one long-term cycle. The cycle lenght's posterior distributions appear to be multimodal with a pronounced peak at a period of 7.1 y with FWHM of 54 d for time-residuals and at a period of 9.8 y with FWHM of 184 d for magitude data. These results are consistent with the previously postulated cycle of 9+/-3 years.Comment: The paper contains 6 figures and 3 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journa

    International consensus on (ICON) anaphylaxis

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    ICON: Anaphylaxis provides a unique perspective on the principal evidence-based anaphylaxis guidelines developed and published independently from 2010 through 2014 by four allergy/immunology organizations. These guidelines concur with regard to the clinical features that indicate a likely diagnosis of anaphylaxis -- a life-threatening generalized or systemic allergic or hypersensitivity reaction. They also concur about prompt initial treatment with intramuscular injection of epinephrine (adrenaline) in the mid-outer thigh, positioning the patient supine (semi-reclining if dyspneic or vomiting), calling for help, and when indicated, providing supplemental oxygen, intravenous fluid resuscitation and cardiopulmonary resuscitation, along with concomitant monitoring of vital signs and oxygenation. Additionally, they concur that H1-antihistamines, H2-antihistamines, and glucocorticoids are not initial medications of choice. For self-management of patients at risk of anaphylaxis in community settings, they recommend carrying epinephrine auto-injectors and personalized emergency action plans, as well as follow-up with a physician (ideally an allergy/immunology specialist) to help prevent anaphylaxis recurrences. ICON: Anaphylaxis describes unmet needs in anaphylaxis, noting that although epinephrine in 1 mg/mL ampules is available worldwide, other essentials, including supplemental oxygen, intravenous fluid resuscitation, and epinephrine auto-injectors are not universally available. ICON: Anaphylaxis proposes a comprehensive international research agenda that calls for additional prospective studies of anaphylaxis epidemiology, patient risk factors and co-factors, triggers, clinical criteria for diagnosis, randomized controlled trials of therapeutic interventions, and measures to prevent anaphylaxis recurrences. It also calls for facilitation of global collaborations in anaphylaxis research. In addition to confirming the alignment of major anaphylaxis guidelines, ICON: Anaphylaxis adds value by including summary tables and citing 130 key references. It is published as an information resource about anaphylaxis for worldwide use by healthcare professionals, academics, policy-makers, patients, caregivers, and the public

    Comparing nuclear power trajectories in Germany and the UK: from ‘regimes' to ‘democracies’ in sociotechnical transitions and Discontinuities

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    This paper focuses on arguably the single most striking contrast in contemporary major energy politics in Europe (and even the developed world as a whole): the starkly differing civil nuclear policies of Germany and the UK. Germany is seeking entirely to phase out nuclear power by 2022. Yet the UK advocates a ‘nuclear renaissance’, promoting the most ambitious new nuclear construction programme in Western Europe.Here,this paper poses a simple yet quite fundamental question: what are the particular divergent conditions most strongly implicated in the contrasting developments in these two countries. With nuclear playing such an iconic role in historical discussions over technological continuity and transformation, answering this may assist in wider understandings of sociotechnical incumbency and discontinuity in the burgeoning field of‘sustainability transitions’. To this end, an ‘abductive’ approach is taken: deploying nine potentially relevant criteria for understanding the different directions pursued in Germany and the UK. Together constituted by 30 parameters spanning literatures related to socio-technical regimes in general as well as nuclear technology in particular, the criteria are divided into those that are ‘internal’ and ‘external’ to the ‘focal regime configuration’ of nuclear power and associated ‘challenger technologies’ like renewables. It is ‘internal’ criteria that are emphasised in conventional sociotechnical regime theory, with ‘external’ criteria relatively less well explored. Asking under each criterion whether attempted discontinuation of nuclear power would be more likely in Germany or the UK, a clear picture emerges. ‘Internal’ criteria suggest attempted nuclear discontinuation should be more likely in the UK than in Germany– the reverse of what is occurring. ‘External’ criteria are more aligned with observed dynamics –especially those relating to military nuclear commitments and broader ‘qualities of democracy’. Despite many differences of framing concerning exactly what constitutes ‘democracy’, a rich political science literature on this point is unanimous in characterising Germany more positively than the UK. Although based only on a single case,a potentially important question is nonetheless raised as to whether sociotechnical regime theory might usefully give greater attention to the general importance of various aspects of democracy in constituting conditions for significant technological discontinuities and transformations. If so, the policy implications are significant. A number of important areas are identified for future research, including the roles of diverse understandings and specific aspects of democracy and the particular relevance of military nuclear commitments– whose under-discussion in civil nuclear policy literatures raises its own questions of democratic accountability

    Perdeuteration of cholesterol for neutron scattering applications using recombinant Pichia pastoris

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    Deuteration of biomolecules has a great impact on both quality and scope of neutron scattering experiments. Cholesterol is a major component of mammalian cells, where it plays a critical role in membrane permeability, rigidity and dynamics, and contributes to specific membrane structures such as lipid rafts. Cholesterol is the main cargo in low and high-density lipoprotein complexes (i.e. LDL, HDL) and is directly implicated in several pathogenic conditions such as coronary artery disease which leads to 17 million deaths annually. Neutron scattering studies on membranes or lipid-protein complexes exploiting contrast variation have been limited by the lack of availability of fully deuterated biomolecules and especially perdeuterated cholesterol. The availability of perdeuterated cholesterol provides a unique way of probing the structural and dynamical properties of the lipoprotein complexes that underly many of these disease conditions. Here we describe a procedure for in vivo production of perdeuterated recombinant cholesterol in lipid-engineered Pichia pastoris. Using flask and fed-batch fermenter cultures in deuterated minimal medium perdeuteration of the purified cholesterol was verified by mass spectrometry and its use in a neutron scattering study was demonstrated using neutron reflectometry
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