2,460 research outputs found

    Library of medium-resolution fiber optic echelle spectra of F, G, K, and M field dwarfs to giants stars

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    We present a library of Penn State Fiber Optic Echelle (FOE) observations of a sample of field stars with spectral types F to M and luminosity classes V to I. The spectral coverage is from 3800 AA to 10000 AA with nominal a resolving power 12000. These spectra include many of the spectral lines most widely used as optical and near-infrared indicators of chromospheric activity such as the Balmer lines (H_alpha, H_beta), Ca II H & K, Mg I b triplet, Na I D_{1} and D_{2}, He I D_{3}, and Ca II IRT lines. There are also a large number of photospheric lines, which can also be affected by chromospheric activity, and temperature sensitive photospheric features such as TiO bands. The spectra have been compiled with the goal of providing a set of standards observed at medium resolution. We have extensively used such data for the study of active chromosphere stars by applying a spectral subtraction technique. However, the data set presented here can also be utilized in a wide variety of ways ranging from radial velocity templates to study of variable stars and stellar population synthesis. This library can also be used for spectral classification purposes and determination of atmospheric parameters (T_eff, log{g}, [Fe/H]). A digital version of all the fully reduced spectra is available via ftp and the World Wide Web (WWW) in FITS format.Comment: Latex file with 17 pages, 4 figures. Full postscript (text and figures) available at http://www.ucm.es/info/Astrof/fgkmsl/FOEfgkmsl.html To be published in ApJ

    WiBAF : Within Browser Adaptation Framework

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    The objective of this thesis project is to develop a framework that provides mechanisms to the user to balance personalization and privacy on the web. To achieve this we suggest a browser based adaptation engine that allows the user to choose what portions of her user model will be stored on the client and what will be on the server, trading privacy for personalization. Given that the server can store some data, data-driven adaptation can be enabled, therefore a way to bring together data-driven and expert-driven adaptation has to be defined. Finally it would be interesting to perform meta-adaptation to enhance this data-driven personaliization. Keywords: Adaptation, client-side modeling, data-driven adaptation, expert-driven adaptation, meta-adaptation, server-side modeling, user modeling

    Epidemiological aspects of Claviceps africana, causal agent of Sorghum ergot

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    Sorghum ergot, caused by Claviceps africana Frederickson, Mantle & de Milliano, is a disease that affects non-fertilized ovaries in sorghum male-sterile plants and infects hybrids if there is pollen sterility at flowering time. Sphacelia containing macroconidia could play a role in the survival of the pathogen. This study developed risk assessment models and evaluated environmental conditions affecting viability of macroconidia and transition from sphacelial to sclerotial tissues. Effect of weather on ergot severity was evaluated under natural conditions (in monthly planting dates) in nine sorghum genotypes at College Station, Weslaco, Rio Bravo, and Celaya. Panicles were inoculated daily beginning at flower initiation with a suspension of 1.6 x 106 C. africana conidia ml-1. Weather triad values were used to identify weather parameters correlated with the disease. Ergot severity was statistically greater in A-lines than hybrids because of the possible interference of pollen on some dates. Celaya had the greatest amount of ergot in hybrids. A-line ATx2752 had the lowest average ergot severity throughout years, locations and planting dates, as did the hybrid NC+8R18. Maximum and minimum temperature had a negative correlation with ergot at Rio Bravo, College Station and Weslaco, while at Celaya it was positive. The highest correlation was 7 to 9 days before initiation of flowering, suggesting that cooler temperatures during this period could cause male sterility. A-lines showed the same relationships between ergot and maximum and minimum temperatures after initiation of flowering. Minimum relative humidity had a positive correlation with ergot after initiation of flowering in both sorghum plant types. Sphacelia stored under cool temperatures (-3oC to 7oC) maintained conidial viability, and newly-formed sphacelia located on the sphacelia surface had the highest conidial viability. However, they show a greater viability reduction through time compared with conidia from older sphacelia, showing that conidial maturity can play a role in the survival of the conidia. Sphacelia on plants grown at 10oC, 20oC and 30oC with low relative humidity did not had any sclerotial development up to 4 weeks after formation of sphacelia. However, higher temperatures promoted an increase in the sphacelia dry weight during that time

    The massive multiple system HD 64315

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    The O6 Vn star HD 64315 is believed to belong to the star-forming region known as NGC 2467, but previous distance estimates do not support this association. We explore the multiple nature of this star with the aim of determining its distance, and understanding its connection to NGC 2467. A total of 52 high-resolution spectra have been gathered over a decade. We use their analysis, in combination with the photometric data from All Sky Automated Survey and Hipparcos catalogues, to conclude that HD 64315 is composed of at least two spectroscopic binaries, one of which is an eclipsing binary. HD 64315 contains two binary systems, one of which is an eclipsing binary. The two binaries are separated by 0.09 arcsec (or 500 AU) if the most likely distance to the system, around 5 kpc, is considered. The presence of fainter companions is not excluded by current observations. The non-eclipsing binary (HD 64315 AaAb) has a period of 2.70962901+/-0.00000021 d. Its components are hotter than those of the eclipsing binary, and dominate the appearance of the system. The eclipsing binary (HD 64315 BaBb) has a shorter period of 1.0189569+/-0.0000008 d. We derive masses of 14.6+-2.3 M_\odot for both components of the BaBb system. They are almost identical; both stars are overfilling their respective Roche lobes, and share a common envelope in an overcontact configuration. The non-eclipsing binary is a detached system composed of two stars with spectral types around O6 V with minimum masses of 10.8 M_\odot and 10.2 M_\odot, and likely masses aprox. 30 M_\odot. HD 64315 provides a cautionary tale about high-mass star isolation and multiplicity. Its total mass is likely above 90 M_\odot,but it seems to have formed without an accompanying cluster. It contains one the most massive overcontact binaries known, a likely merger progenitor in a very wide multiple system.Comment: 14 pages, 13 figures, 8 Table

    My Problems Are Solvable: Idiographic Methods Offset Age Differences in Interpersonal Problem Solving Among Young, Middle-Aged, and Older Adults

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    This study tested the hypothesis that older adults retain high levels of everyday problem solving performance when confronting problems of maximal ecological relevance, identified through idiographic methods. Younger, middle-aged, and older adults completed a daily challenge questionnaire (DCQ) in which they reported problems of maximal personal relevance or idiographic problems. The large majority of the problems reported were interpersonal. We then assessed performance on an everyday problem-solving task in which participants generated solutions for idiographic problems as well as problems generated by group matched research participants representing each of two other age groups (e.g., older adults received their own problems plus problems generated by matched younger and middle-aged adults). Performance was measured by computing the total number of safe and effective solutions provided. Results fully supported our hypothesis; adults of all ages showed higher performance when solving their idiographic problems

    Adaptive applications to assist students with autism in succeeding in higher education

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    In this demo we discuss a few possible scenarios showing adaptation of presentation and information to assist autistic students in succeeding in higher education. These students not only have specific information need, they are also more concerned about their privacy. We use WiBAF (Within Browser Adaptation Framework) for user modeling and adaptation to give users control over the sharing of their data

    Ecological design of a crayfishing program to control population density of the invasive species Procambarus Clarkii in Doñana National Park freshwater marsh (Spain)

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    The exploitation of Procambarus clarkii in Doñana National Park’s freshwater marsh (DNP) has been economically important to the local human population since the 1970s. The high density of this crayfish species has been causing a major environmental impact in the Park by the substantial reduction of submerging aquatic macrophytes prairies due to its broad trophic spectrum and feeding habits, which turned the environmental frame (consisting in clear water equilibrium) into a turbid water balance. Differences in population dynamics of three population groups of P. clarkii in the DNP freshwater marsh were compared and analyzed from a fishery perspective. The objective is to reduce their ecological impact using optimal crayfishing management. Maximum growth curves showed that crayfish have different growth optimums. Recruitment of young crayfish varies between different populations; when there is an excessive increase in the density of juveniles in a population and conditions are stressful, their growth is deficient. If these conditions persist, the population could become stunted. Fishery for commercial gain is banned in DNP; however, a model of fisheries program aimed at controlling the excess population of crayfish can be effective in halting the ecological impact of this invasive species while providing an opportunity for poachers to have viable productive options. The model proposed can help to solve the problem of crayfish “poaching” through the legalization and strict control of harvesting practicesPedro J. Gutiérrez-Yurrita also thanks the ICI (Spain) for a subvention grant and CONACyT (México) for a financial complement of the former grant that enabled him to complete this researc

    City Angels

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    City Angels se desarrolla con el objetivo de conectar en caso de emergencia a las personas con necesidades especiales (que pueden ir desde niños pequeños que requieran supervisión adulta, a personas mayores con problemas de movilidad y/o lucidez) y las personas que desean ayudarlas o bien se dedican a su supervisión. Este sistema engloba una red social para el registro y gestión de usuarios, un panel de control y una aplicación móvil, cuyo objetivo es la notificación de alertas lanzadas por personas con necesidades y la búsqueda de personas dispuestas a ayudar que estén próximas a la alerta, proporcionando a ambas partes un sistema que cumpla con sus necesidades en cada caso (desde proporcionar contactos de emergencia, llamadas a servicios de emergencia o dar la información necesaria para llegar al lugar donde se encuentra la persona que necesita ayuda).City Angels has been developed with the goal of connecting, in an emergency case, the people with special needs (which can be kids, disabled individuals, elder people…) and the people who want to help them or have responsibility on their supervision. This system encompasses a social network, a control panel and a mobile application, that allows the notification of alerts from the people with special needs and the search of the closest people who can help, bringing a system that enables both parts to achieve their needs (providing emergency contacts, emergency calls or giving information to reach the person who needs help).City Angels es desenvolupa amb l'objectiu de connectar en cas d'emergència a les persones amb necessitats especials (les quals poden anar des de nens petits que requereixen supervisió d'un adult, a persones grans amb problemes de mobilitat i/o lucidesa) i les persones que desitgen ajudar-les o bé es dediquen a la seva supervisió. Aquest sistema engloba una xarxa social pel registre i gestió d'usuaris, un panell de control i una aplicació mòbil, l'objectiu de la qual és la notificació d'alertes creades per les persones amb necessitats i la cerca de les persones disposades a ajudar que estiguin pròximes a l'alerta, proporcionant a ambdues parts un sistema que compleixi les seves necessitats en cada cas (des de proporcionar contactes d'emergència, trucades als serveis d'emergència o donar la informació necessària per arribar al lloc on es troba la persona que necessita ajuda)

    My Problems Are Solvable: Idiographic Methods Offset Age Differences in Interpersonal Problem Solving Among Young, Middle-Aged, and Older Adults

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    This study tested the hypothesis that older adults retain high levels of everyday problem solving performance when confronting problems of maximal ecological relevance, identified through idiographic methods. Younger, middle-aged, and older adults completed a daily challenge questionnaire (DCQ) in which they reported problems of maximal personal relevance or idiographic problems. The large majority of the problems reported were interpersonal. We then assessed performance on an everyday problem-solving task in which participants generated solutions for idiographic problems as well as problems generated by group matched research participants representing each of two other age groups (e.g., older adults received their own problems plus problems generated by matched younger and middle-aged adults). Performance was measured by computing the total number of safe and effective solutions provided. Results fully supported our hypothesis; adults of all ages showed higher performance when solving their idiographic problems
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