3,204 research outputs found

    A ringed pole-on outflow from DO Tauri revealed by ALMA

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    We present new ALMA Band 6 observations including the CO (2-1) line and 1.3 mmcontinuum emission from the surroundings of the young stellar object DO Tauri. TheALMA CO molecular data show three different series of rings at different radial ve-locities. These rings have radii around 220 au and 800 au. We make individual fits tothe rings and note that their centers are aligned with DO Tauri and its optical high-velocity jet. In addition, we notice that the velocity of these structures increases withthe separation from the young star. We discuss the data under the hypothesis that therings represent velocity cuts through three outflowing shells that are possibly drivenby a wide-angle wind, dragging the environment material along a direction close to theline of sight (i= 19◦). We estimate the dynamical ages, the mass, the momentum andthe energy of each individual outflow shell and those of the whole outflow. The resultsare in agreement with those found in outflows from Class II sources. We make a roughestimate for the size of the jet/wind launching region, which needs to be of.15 au.We report the physical characteristics of DO Tauri?s disk continuum emission (almostface-on and with a projected major axis in the north-south direction) and its velocitygradient orientation (north-south), indicative of disk rotation for a 1-2 Mcentral star.Finally we show an HST [SII] image of the optical jet and report a measurement of itsorientation in the plane of the sky.Fil: Fernandez Lopez, Manuel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Zapata Gonzalez, Luis Alberto. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Rodríguez, Luis F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Guzman, Andrés E.. National Astronomical Observatory Of Japan; JapónFil: López, Rosario. Universidad Autónoma de Barcelona. Facultad de Física. Departamento Astronomía y Meteorología; Españ

    The Squeaky Wheel Gets the Oil? On the Interpersonal Effects of Boredom Expression

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    I explored how people react to employees who express boredom at work. I consider boredom expression as a social signal that the current situation does not adequately stimulate the expresser. The expression may then propel others to help stimulate the expresser, depending partly on others’ initial appraisals and reactions to the expression, and on the surrounding context. In Study 1, using qualitative surveys, I uncovered various affective, cognitive, and behavioral reactions to employees who expressed boredom. In Study 2, using experimental vignettes, I manipulated the emotion expressed by a “subordinate” (boredom, enthusiasm, or no emotion) and the manager’s beliefs about the task at hand (as interesting, boring, or neither) to examine managers’ emotions (anger, guilt), cognitions (inferences about the expresser’s job apathy), and behaviors (punishment, individualized consideration) following subordinates’ emotional expressions. I found that relative to other emotion expressions, boredom expressions led to greater anger, guilt, and inferences of job apathy. Expressions of boredom and enthusiasm both led to stronger desires to punish the expresser, relative to no expression. Lastly, boredom expressions indirectly led to more punishment and less individualized consideration toward the expresser via inferences of the expresser’s job apathy. My dissertation thus illuminates how expressions of boredom influence reactions to bored employee in favorable or unfavorable ways for the expresser and the organization

    Landscape Assessment via Regression Analysis

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    This paper presents a methodology for assessing the visual quality of agricultural landscapes through direct and indirect techniques of landscape valuation. The first technique enables us to rank agricultural landscapes on the basis of a survey of public preferences. The latter weighs the contribution of the elements and attributes contained in the picture to its overall scenic beauty via regression analysis. The photos used in the survey included man-made elements, positive and negative, agricultural fields, mainly of cereals and olive trees, and a natural park. The results show that perceived visual quality increases, in decreasing order of importance, with the degree of wilderness of the landscape, the presence of well-preserved man-made elements, the percentage of plant cover, the amount of water, the presence of mountains and the colour contrast.landscape assessment, visual quality, landscape elements, landscape value, Land Economics/Use, H41, Q21, Q26,

    Motor Deficits Are Produced By Removing Some Cortical Transplants Grafted Into Injured Sensorimotor Cortex of Neonatal Rats

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    Fetal frontal cortex was transplanted into cavities formed in the right, motor cortex of neonatal rats. As adults, the animals were trained to press two levers in rapid succession with their left forelimb to receive food rewards. Once they had reached an optimal level of performance, the effect of removing their transplants was assessed. Surgical removal of transplants significantly impaired the performance of 2 of 4 subjects. Placing a crossstrain skin graft to induce the immunological rejection of the transplants produced a behavioral deficit in 1 of 2 subjects with complete transplant removal. Skin grafts produced no behavioral effects in four subjects that had surviving transplants. Since the motor deficit produced by transplant removal resembled those observed following the removal of normal motor cortex, we propose that these three transplants functioned within the host brain

    Portuguese 16th to Early 18th Century tin Glazed Ceramics Found at the Tagus Estuary Saltpans

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    UID/NAN/50024/2019 M-ERA-MNT/0002/2015 UIDB/04209/2020 UIDP/04209/2020Salt was extracted from saltpans, in the South shore of Tagus River by evaporation of the salted sea water which penetrates into the estuary. The walls and the bottom of those saltpans were made of local clays to retain the sea water, and ceramic sherds have been used to endure those walls and also to allow people to walk on the saltpans’ walls. Those sherds constitute an example of the ceramics production in Lisbon workshops, starting in the mid-16th century and reaching high levels of quality in the 17th and 18th century. A detailed archaeometric study of 14 selected sherds dated from the 16th to the early 18th century has been made and the conjugation of the information provided by the micro-Raman, XRD and XRF experiments for those sherds and clays collected locally, allowed us the characterisation of the Lisbon ceramics in that period. Three main groups could be identified in the ceramic bodies; all made with locally collected clays of Miocene origin. In the first group, the potters used raw materials from the clay sources located at Santa Catarina area in Lisbon, most probably mixed with Lapa clays, which were fired at a high temperatures, ranging from 850ºC to 950ºC. Gehlenite and quartz are the dominant minerals of these ceramic bodies. In the second and third groups of Lisbon ceramic bodies, made with Prazeres clays, diopside was also detected but with variable amounts of gehlenite. Clay formations mineralogy mainly include kaolinite, muscovite/illite, quartz, calcite, and feldspars (albite and microcline).publishersversionpublishe

    “Where’s the I-O?” Artificial Intelligence and Machine Learning in Talent Management Systems

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    Artificial intelligence (AI) and machine learning (ML) have seen widespread adoption by organizations seeking to identify and hire high-quality job applicants. Yet the volume, variety, and velocity of professional involvement among I-O psychologists remains relatively limited when it comes to developing and evaluating AI/ML applications for talent assessment and selection. Furthermore, there is a paucity of empirical research that investigates the reliability, validity, and fairness of AI/ML tools in organizational contexts. To stimulate future involvement and research, we share our review and perspective on the current state of AI/ML in talent assessment as well as its benefits and potential pitfalls; and in addressing the issue of fairness, we present experimental evidence regarding the potential for AI/ML to evoke adverse reactions from job applicants during selection procedures. We close by emphasizing increased collaboration among I-O psychologists, computer scientists, legal scholars, and members of other professional disciplines in developing, implementing, and evaluating AI/ML applications in organizational contexts

    La reforma de la formación inicial del profesorado de ciencias de secundaria: propuesta de un diseño del currículo basado en competencias

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    El principal objetivo de este trabajo es proponer un mecanismo de selección de competencias específicas para la formación inicial del profesorado de ciencias experimentales, contando para ello con distintas fuentes relevantes para dicha formación. Con tal fin hemos hecho uso de un procedimiento consistente en ir incorporando de forma crítica las competencias procedentes de las siguientes fuentes curriculares: los modelos de formación inicial del profesorado vigentes en la literatura educativa, el currículo actual de ciencias en la educación secundaria obligatoria en España, el Programa internacional de evaluación PISA, la opinión del profesorado en activo mediante una encuesta cuyos resultados más relevantes son mostrados, las concepciones epistemológicas del profesorado, la profesionalización docente y las demandas que genera y, finalmente, la dimensión social de la ciencia.The primary objective of this paper is to propose a mechanism for selecting specific competences for preservice science teacher training, referring to relevant sources for such training. To this end we have used an trans-disciplinary procedure consistent with incorporating critical competences from the following curricular sources: Models of current preservice teacher training in educational literature, the current curriculum of Science in Compulsory Secondary Education in Spain, the Program for International Student Assessment (PISA), the views of in-service secondary school teachers (through a survey whose most relevant results are given), teachers' epistemological conceptions, the professionalization of teaching and the demands it generates and, finally the social dimension of science

    Experimental study and calculation of the electron transfer coefficients on the dissolution behavior of chitosan in organic acids

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    Chitosan (CH) consists of water-insoluble N-acetylglucosamine and D-glucosamine molecules and has a higher solubility at a pH below six. This studyevaluated the solubility of chitosan in solutions of organic acids for the formation of films. HyperChemTMsoftware was used to perform the quantum analysis. In the experimental trials, the total soluble mass (TSM) and the viscosity of the solutions were measured by capillary viscometer. The chitosan filmswere made by the plate melting method, and the filmcharacteristics were evaluated. A quantum simulation suggested that lactic acid (LA) has a greater stability to react with chitosan. It was then verified experimentally that LA is a better solvent for chitosan due to the increase in its viscosity. The chemical interaction between CH and LA in solution favors the polymerization of films with better physical properties. We thereforeconclude that the uniformity in the formation of films of this polymer depends on the chemical interaction between the CH and the acid and not on the degree of solubility of the polymer
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