9,017 research outputs found

    A non-resonant dark-side solution to the solar neutrino problem

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    We re-analyse spin-flavour precession solutions to the solar neutrino problem in the light of the recent SNO CC result as well as the 1258--day Super-Kamiokande data and the upper limit on solar anti-neutrinos. In a self-consistent magneto-hydrodynamics approach the resulting scheme has only 3 effective parameters: Δm2\Delta m^2, μB\mu B_\perp and the neutrino mixing angle θ\theta. We show how a rates-only analysis for fixed μB\mu B_\perp slightly favours spin-flavour precession (SFP) solutions over oscillations (OSC). In addition to the resonant solution (RSFP for short), there is a new non-resonant solution (NRSFP) in the ``dark-side''. Both RSFP and NRSFP lead to flat recoil energy spectra in excellent agreement with the latest SuperKamiokande data. We also show that in the presence of a neutrino transition magnetic moment of 101110^{-11} Bohr magneton, a magnetic field of 80 KGauss eliminates all large mixing solutions other than the so-called LMA solution.Comment: 12 pages, 3 postscript figures, using elsart.cls. Published versio

    Temporal Electrical Response of V/W-shaped Chiral Smectic Liquid Crystal Displays

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    Chiral smectic liquid crystal cells showing V-shaped electrooptical switching have been reported as one of the most promising technologies for high-end display applications. In this work, time-resolved electrical behaviour of these devices has been obtained through a set of systematic measurements. The electrical equivalent circuit has been derived, a number of simulations at different frequencies have been performed using commercial software for analogue circuits. Performance of this electrical model to account for time domain variations of switching currents in chiral smectic LC displays with V/W-shaped electrooptical response has been analyzed as well

    Location, orbit and energy of a meteoroid impacting the moon during the Lunar Eclipse of January 21, 2019

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    During lunar eclipse of January 21, 2019 a meteoroid impacted the Moon producing a visible light flash. The impact was witnessed by casual observers offering an opportunity to study the phenomenon from multiple geographical locations. We use images and videos collected by observers in 7 countries to estimate the location, impact parameters (speed and incoming direction) and energy of the meteoroid. Using parallax, we achieve determining the impact location at lat. 29.430.21+0.30-29.43^{+0.30}_{-0.21}, lon. 67.890.09+0.07-67.89^{+0.07}_{-0.09} and geocentric distance as 356553 km. After devising and applying a photo-metric procedure for measuring flash standard magnitudes in multiple RGB images having different exposure times, we found that the flash, had an average G-magnitude G=6.7±0.3\langle G\rangle = 6.7\pm0.3. We use gravitational ray tracing (GRT) to estimate the orbital properties and likely radiant of the impactor. We find that the meteoroid impacted the moon with a speed of 146+714^{+7}_{-6} km/s (70% C.L.) and at a shallow angle, θ<38.2\theta < 38.2 degrees. Assuming a normal error for our estimated flash brightness, educated priors for the luminous efficiency and object density, and using the GRT-computed probability distributions of impact speed and incoming directions, we calculate posterior probability distributions for the kinetic energy (median KmedK_{\rm med} = 0.8 kton), body mass (MmedM_{\rm med} = 27 kg) and diameter (dmedd_{\rm med} = 29 cm), and crater size (DmedD_{\rm med} = 9 m). If our assumptions are correct, the crater left by the impact could be detectable by prospecting lunar probes. These results arose from a timely collaboration between professional and amateur astronomers which highlight the potential importance of citizen science in astronomy.Comment: 19 pages, 11 figures, 4 tables. Data and scripts available in https://github.com/seap-udea/MoonFlashes. Accepted for publication in MNRA

    The Impact of Stiffness in Bimanual Versus Dyadic Interactions Requiring Force Exchange.

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    During daily activities, humans routinely manipulate objects bimanually or with the help of a partner. This work explored how bimanual and dyadic coordination modes are impacted by the object's stiffness, which conditions inter-limb haptic communication. For this, we recruited twenty healthy participants who performed a virtual task inspired by object handling, where we looked at the initiation of force exchange and its continued maintenance while tracking. Our findings suggest that while individuals and dyads displayed different motor behaviours, which may stem from the dyad's need to estimate their partner's actions, they exhibited similar tracking accuracy. For both coordination modes, increased stiffness resulted in better tracking accuracy and more correlated motions, but required a larger effort through increased average torque. These results suggest that stiffness may be a key consideration in applications such as rehabilitation, where bimanual or external physical assistance is often provided

    Ideas and Enhancements Related to Mobile Applications to Support Type 1 Diabetes

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    Background: Mobile devices have become increasingly important to young people who now use them to access a wide variety of health-related information. Research and policy related to the integration of health information and support with this technology do not effectively consider the viewpoint of a younger patient. Views of young people with type 1 diabetes are vital in developing quality services and improving their own health-related quality of life (HRQOL), yet research on their lifestyle and use of Web and mobile technology to support their condition and in non–health-related areas is sparse. Objective: To develop insight into young people with type 1 diabetes and their current use of Web and mobile technology and its potential impact on HRQOL. This can be achieved by constructing an in-depth picture of their day-to-day experiences from qualitative interviewing and exploring how they make use of technology in their lives and in relation to their condition and treatment. The goal was then to build something to help them, using the researcher’s technical expertise and seeking users’ opinions during the design and build, utilizing sociotechnical design principles. Methods: Data were collected by semistructured, in-depth qualitative interviews (N=9) of young people with type 1 diabetes aged 18-21. Interviews were transcribed and loaded onto NVivo for theme identification. Data analysis was undertaken during initial interviews (n=4) to locate potential ideas and enhancements for technical development. Latter interviews (n=5) assisted in the iterative sociotechnical design process of the development and provided additional developmental ideas. Results: Six themes were identified providing an understanding of how participants lived with and experienced their condition and how they used technology. Four technological suggestions for improvement were taken forward for prototyping. One prototype was developed as a clinically approved app. A number of ideas for new mobile apps and enhancements to currently existing apps that did not satisfactorily cater to this age group’s requirements for use in terms of design and functionality were suggested by interviewees but were not prototyped. Conclusions: This paper outlines the nonprototyped suggestions from interviewees and argues that young people with type 1 diabetes have a key role to play in the design and implementation of new technology to support them and improve HRQOL. It is vital to include and reflect on their suggestions as they have a radically different view of technology than either their parents or practitioners. We need to consider the relationship to technology that young people with type 1 diabetes have, and then reflect on how this might make a difference to them and when it might not be a suitable mechanism to use

    Calculating Directivities with the 2D Simpson's Rule

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    [Abstract] C++ routines implementing the simple generalization of Simpson's rule to two dimensions for calculating antenna directivities compare well with methods currently available in common symbolic and numerical calculation packages

    Value Webs: Using Ontologies to Bundle Real-World Services

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    The difference between the Real-world services and the Web Services is discussed. Real-world services are software functionality, accessible and configurable over the Web. The Ontology-Based Electronic Integration of Complex Products and Value Chains (OBELIX) project has developed a component-based ontology for real-world services, along with methods and tools for graphical modeling of services and for knowledge-based configuration of service bundles. The development of ontologies, as formal conceptualizations, aims to bridge human and computer understanding. It is found that an ontology is good, if it is used in and validated against independent, external business scenarios and industrial use cases.The European Commission partially supported this work in the context of the EU-IST Project OBELIX (Ontology-Based Electronic Integration of Complex Products and Value Chains, EU-IST-2001-33144). For models, tools, and data on application examples, we’re indebted to Andrei Morch, Hanne Sæle, and Gunnar Salseggen (SINTEF Energy Research and TrønderEnergi, Norway); Hans-Peter Schnurr, Hans Trost, and Wolfgang Sperling (Ontoprise, Germany); Bert Hazelaar (SENA, Netherlands); and Tim Smithers, Jessica Aguado, Carlos Pedrinaci, and Amaia Bernaras (Technological Park of San Sebastian, Spain). Arthur Koks, Dennis Veltrop, Rashid Sohrabkhan, and Stephan Hoekstra (Free Univ.Amsterdam) did much of the tool development reported in this article. We also thank Terry Payne (Univ. of Southampton) for many in-depth discussions on DAML/ OWL-S, and the anonymous reviewers for several useful comments that we incorporated.Peer reviewe

    Estudio de expresión diferencial de genes y distribución de la vinculina en ovario de cerdas

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    Ponencia publicada en ITEA, vol.104El objetivo de este estudio es analizar las diferencias en la expresión de genes y proteínas en tres estadios reproductivos en cerdas. Con el fin de caracterizar los cambios en los perfiles de expresión, se hibridó RNA de ovario de cerdas en celo, 15 y 45 días de gestación en microchips porcinos. Se detectaron diferencias de expresión en 281 genes (probabilidad posterior <10-11) entre los tres momentos reproductivos analizados en ovario. Uno de estos genes, la vinculina, mostró una expresión 100 veces mayor en celo comparado con 45 días de gestación. Por ello, fue escogido para realizar un análisis de expresión proteica mediante inmunohistoquímica y análisis western blot. Los resultados obtenidos mediante inmunohistoquímica muestran mayor cantidad de vinculina en celo que a 30 días de gestación. Para esta misma proteína, los resultados sugieren la existencia de diferencias significativas entre ovarios de cerdas en celo y a 45 días de gestación mediante la técnica western blotStudy on the differential gene expression and distribution of the vinculin in the ovary of sows The objective of this experiment is to study genes and proteins differing across reproductive stages in swine. RNA from ovary, from sows on heat, 15 and 45 days of pregnancy have been hybridised in porcine oligonucleotide microchips to characterize changes in gene expression profile between different reproductive stages. Expression differences in 281 genes (posterior probability <10-11) have been found between expression at different stages in ovary. One of these genes, vinculin, showed 100 times more expression on heat than at 45 days of pregnancy, so we chose that gene for immunohistochemistry and western blot analysis. On immunohistochemistry we found that ovaries of sows on heat showed stronger vinculin staining than ovaries stroma of sows at 30 days of pregnancy. On western blot, significant differences appeared only between heat and 45 days of pregnancy

    A comparative study of extraction apparatus in HPLC analysis of ochratoxin A in muscle

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    Abstract Ochratoxin A (OTA) is a secondary fungal metabolite produced by several moulds, mainly by Aspergillus ochraceus and by Penicillium verrucosum, that occurs in meat products. The aim of this work was to optimize an efficient extraction procedure for the determination of OTA in muscle tissue in order to assess its occurrence in meat samples. Three different apparatus, a Waring blender, a switching apparatus, and an ultrasonic processor, were evaluated to verify the efficiency of extraction. The analytical methods proposed involve the extraction with chloroform-orthophosphoric acid, cleanup through an immunoaffinity column, high-performance liquid chromatography/fluorescence detection for separation and identification of OTA, and confirmation with liquid chromatography/FD after methylation of OTA in muscle tissue. The limit of quantification of the proposed method was 0.04 µg kg-1. Recoveries of OTA, using switching apparatus, ranged from 90.3 to 103.2% for chicken muscle spiked at 2.4 and 0.48 µg kg-1, respectively, with a within-day relative standard deviation of 17 and 15.3%. The proposed method was applied to 38 chicken, swine, and turkey muscle samples and the presence of OTA was confirmed in five samples. Finally, the estimated daily intake of OTA in this study was between 23 pg kg-1 body weight per day for swine samples and 18 pg kg-1 body weight per day for turkey samples
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