995 resultados para Sean Ociepka


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Sunspots on the surface of the Sun are the observational signatures of intense manifestations of tightly packed magnetic field lines, with near-vertical field strengths exceeding 6,000 G in extreme cases1. It is well accepted that both the plasma density and the magnitude of the magnetic field strength decrease rapidly away from the solar surface, making high-cadence coronal measurements through traditional Zeeman and Hanle effects difficult as the observational signatures are fraught with low-amplitude signals that can become swamped with instrumental noise2, 3. Magneto-hydrodynamic (MHD) techniques have previously been applied to coronal structures, with single and spatially isolated magnetic field strengths estimated as 9–55 G (refs 4,5,6,7). A drawback with previous MHD approaches is that they rely on particular wave modes alongside the detectability of harmonic overtones. Here we show, for the first time, how omnipresent magneto-acoustic waves, originating from within the underlying sunspot and propagating radially outwards, allow the spatial variation of the local coronal magnetic field to be mapped with high precision. We find coronal magnetic field strengths of 32 ± 5 G above the sunspot, which decrease rapidly to values of approximately 1 G over a lateral distance of 7,000 km, consistent with previous isolated and unresolved estimations. Our results demonstrate a new, powerful technique that harnesses the omnipresent nature of sunspot oscillations to provide magnetic field mapping capabilities close to a magnetic source in the solar corona.

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Holocene cryptotephras of Alaskan and Pacific Northwestern origin have recently been detected ca. 7000 km away on the east coast of North America. This study extends the emerging North American tephrochronological framework by geochemically characterising seventeen cryptotephra layers from four newly explored peatlands. All detected tephras were deposited during the late Holocene, with no horizons present in the peat between ca. 3000–5000 years ago. The prevalence of the Alaskan White River Ash eastern lobe (AD 847 ± 1) is confirmed across the eastern seaboard from Newfoundland to Maine and a regional depositional pattern from Mount St Helens Set W (AD 1479–1482) is presented. The first occurrences of four additional cryptotephras in eastern North America are described, three of which may originate from source regions in Mexico, Kamchatka (Russia) and Hokkaido (Japan). The possibility of such tephras reaching eastern North America presents the opportunity to link palaeo-archives from the tropics and eastern Asia with those from the western Atlantic seaboard, aiding inter-regional comparisons of proxy-climatic records.

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We present the Coordinated Synoptic Investigation of NGC 2264, a continuous 30 day multi-wavelength photometric monitoring campaign on more than 1000 young cluster members using 16 telescopes. The unprecedented combination of multi-wavelength, high-precision, high-cadence, and long-duration data opens a new window into the time domain behavior of young stellar objects. Here we provide an overview of the observations, focusing on results from Spitzer and CoRoT. The highlight of this work is detailed analysis of 162 classical T Tauri stars for which we can probe optical and mid-infrared flux variations to 1% amplitudes and sub-hour timescales. We present a morphological variability census and then use metrics of periodicity, stochasticity, and symmetry to statistically separate the light curves into seven distinct classes, which we suggest represent different physical processes and geometric effects. We provide distributions of the characteristic timescales and amplitudes and assess the fractional representation within each class. The largest category (>20%) are optical "dippers" with discrete fading events lasting ~1-5 days. The degree of correlation between the optical and infrared light curves is positive but weak; notably, the independently assigned optical and infrared morphology classes tend to be different for the same object. Assessment of flux variation behavior with respect to (circum)stellar properties reveals correlations of variability parameters with Hα emission and with effective temperature. Overall, our results point to multiple origins of young star variability, including circumstellar obscuration events, hot spots on the star and/or disk, accretion bursts, and rapid structural changes in the inner disk. Based on data from the Spitzer and CoRoT missions. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain.

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The emergence of open innovation theory and practice, alongside the evolution to a quadruple helix system of innovation, has led to a need for universities to rethink their models of engagement with industry and wider society. One important element in this system is the entrepreneurial academics; however there is a lack of research considering the motivations of entrepreneurial academics, who differ from academic entrepreneurs, to engage in knowledge transfer in line with open innovation policy. This research offers practical insights on whether new models of engagement, increasingly offered by universities, really address the policy drivers for open innovation. Furthermore, this research explores whether these activities might motivate entrepreneurial academics to participate. Preliminary findings identify that many supposedly new collaboration activities do not really motivate entrepreneurial academics. This may have important implications on the ability of universities to become truly open and to encourage their academics to become engaged in collaboration and impact.

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Intestinal smooth muscle contracts rhythmically in the absence of nerve and hormonal stimulation because of the activity of pacemaker cells between and within the muscle layers. This means that the autonomic nervous system modifies rather than initiates intestinal contractions. The practical described here gives students an opportunity to observe this spontaneous activity and its modification by agents associated with parasympathetic and sympathetic nerve activity. A section of the rabbit small intestine is suspended in an organ bath, and the use of a pressure transducer and data-acquisition software allows the measurement of tension generated by the smooth muscle of intestinal walls. The application of the parasympathetic neurotransmitter ACh at varying concentrations allows students to observe an increase in intestinal smooth muscle tone with increasing concentrations of this muscarinic receptor agonist. Construction of a concentration-effect curve allows students to calculate an EC50 value for ACh and consider some basic concepts surrounding receptor occupancy and activation. Application of the hormone epinephrine to the precontracted intestine allows students to observe the inhibitory effects associated with sympathetic nerve activation. Introduction of the drug atropine to the preparation before a maximal concentration of ACh is applied allows students to observe the inhibitory effect of a competitive antagonist on the physiological response to a receptor agonist. The final experiment involves the observation of the depolarizing effect of K+ on smooth muscle. Students are also invited to consider why the drugs atropine, codeine, loperamide, and botulinum toxin have medicinal uses in the management of gastrointestinal problems.

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A suite of lipid biomarkers were investigated from surface sediments and particulate matter across hydrographically distinct zones associated with the western Irish Sea gyre and the seasonal bloom. The aim was to assess the variation of organic matter (OM) composition, production, distribution and fate associated with coastal and southern mixed regions and also the summer stratified region. Based on the distribution of a suite of diagnostic biomarkers, including phospholipid fatty acids, source-specific sterols, wax esters and C25 highly branched isoprenoids, diatoms, dinoflagellates and green algae were identified as major contributors of marine organic matter (MOM) in this setting. The distribution of cholesterol, wax esters and C20 and C22 polyunsaturated fatty acids indicate that copepod grazing represents an important process for mineralising this primary production. Net tow data from 2010 revealed much greater phytoplankton and zooplankton biomass in well-mixed waters compared to stratified waters. This appears to be largely reflected in MOM input to surface sediments. Terrestrial organic matter (TOM), derived from higher plants, was identified as a major source of OM regionally, but was concentrated in proximity to major riverine input at the Boyne Estuary and Dundalk Bay. Near-bottom residual circulation and the seasonal gyre also likely play a role in the fate of TOM in the western Irish Sea.

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El presente estudio ha sido realizado con la finalidad de determinar las causas que inducen a que los procesos administrativos sean lentos e ineficientes en la empresa Avícola Tanda – Quinche, en los años 2004. 2005, 2006 y 2007 y la proyección anual en los procesos administrativos hasta el año 2010. A la vez, se busca identificar en qué magnitud afectan los procesos administrativos lentos e ineficientes, en relación con la productividad del personal y los lineamientos estratégicos que se podrían emprender en el mejoramiento de los procesos administrativos de la empresa, con el fin de disminuir el porcentaje de salida del personal. Para ello es necesario conocer las características generales de la empresa, el contexto en el cual se desarrolla y de este modo realizar un análisis más real y objetivo del problema que la empresa enfrenta.

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Una nueva teoría debe ir más allá de la ventaja comparativa y llegar a la ventaja competitiva de una nación. Debe explicar por qué las empresas de una nación consiguen ventajas competitivas en todas sus formas, que no solamente en los limitados tipos de ventajas basadas en los factores que se contemplan en la teoría de la ventaja comparativa. La mayoría de las teorías del comercio se fijan exclusivamente en el costo y tratan como nota a pie de página la calidad y los productos diferenciados. Una nueva teoría debe reflejar un rico concepto de la competencia que comprenda los mercados segmentados, los productos diferenciados, las diferencias en las tecnologías y las economías de escala. La calidad, las características y la innovación en los nuevos productos son determinantes en los sectores y segmentos avanzados. Además, la ventaja en los costos se deriva tanto de los diseños que permiten una fabricación eficiente y de las tecnologías avanzadas de proceso cuanto de los costos de los factores o incluso de las economías de escala. Debemos comprender las razones de que algunas naciones sean mejores que otras en la creación de estas ventajas, tan esenciales para la alta y creciente productividad1. En el presente estudio se interrelacionó la investigación documental y la investigación de campo; permitiendo demostrar que la producción de tomate riñón (o Lycopersicum Esculentum, pertenece a la familia de las solanáceas) bajo invernadero, tal como se plantea es técnica y económicamente factible; ya que el cultivo de tomate riñón es uno de los más representativos en cuanto a hortalizas, además, dado que el tomate constituye uno de los principales productos que la gente consume diariamente en sus comidas, lo hace acreedor a una gran demanda diaria sea en su presentación natural o ya procesado, por ejemplo tomate enlatado, pasta de tomate, salsa de tomate, entre otras.

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La revisión de los perfiles profesionales relacionados con la lengua de signos española y su formación es una de las acciones más relevantes del Centro de Normalización Lingüística de la Lengua de Signos Española (CNLSE). El presente informe comienza con información relativa a la trayectoria seguida por el especialista en lengua de signos española, para continuar con los ámbitos de actuación y el perfil competencial actual. Con este análisis, se proponen actualizaciones y algunas novedades para que sean tenidas en cuenta en los planes de estudio que puedan surgir a partir de los nuevos requerimientos competenciales exigidos. El informe hace hincapié en la necesidad de abordar esta cuestión con celeridad debido a la situación actual de este perfil profesional.

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Continuaremos el trabajo del semestre anterior, es decir, que expondremos el filosofar tojolabal en su particularidad y a diferencia del filosofar occidental. El NOSOTROS sigue siendo el concepto clave a partir del cual se explica la organización socio-política, la particularidad de la educación y otros aspectos idiosincráticos de la cosmovisión y cosmovivencia del filosofar de éste y otros pueblos mayas y también de otros pueblos originarios. Los libros de texto y las lecturas recomendadas señalan los temas que enfocaremos. Otra vez notaremos que el idioma tojolabal nos abre la puerta para entrar al filosofar tan característico de los tojolabales. Pensamos que el mismo enfoque de las lenguas respectivas podría abrirnos una entrada al filosofar occidental, aunque los conceptos destacados no siempre se explicarían en los libros de filósofos occidentales. Lo observaremos al comparar conceptos claves del filosofar tojolabal con los correspondientes del español y otras lenguas de sociedades dominantes. Por ejemplo, personas occidentales se sienten bien al decirles que son jóvenes aunque no lo sean, y todo lo contrario al decirles que son viejos o ancianos. Nadie quiere ser anciano ni viejo. En tojolabal, en cambio, no se glorifica la juventud pero sí se respeta la vejez. Basta la breve referencia que a lo largo del semestre tendremos tiempo para ampliarla.

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It is now apparent that socio-cultural constructions of masculinity variously impact men’s experiences of their HIV positive status, yet how being a father can feature in this mix remains under-researched. This study employed in-depth semi-structured interviews and Foucauldian-informed discourse analysis to explore the accounts of six self-identifying heterosexual fathers (four black African migrants, two white European) who had been living with HIV from five to 24 years. While the HIV-related literature calls for the need to subvert ‘traditional’ expressions of masculinity as a means of promoting HIV prevention and HIV health, we argue that the lived experience for HIV positive men as fathers is more socially, discursively and thus more psychologically nuanced. We illustrate this by highlighting ways in which HIV positive men as fathers are not simply making sense of themselves as a HIV positive man for whom the modern (new) man and father positions are useful strategies for adapting to HIV and combating associated stigma. Discourses of modern and patriarchal fatherhoods, a gender-specific discourse of irresponsibility, and the neoliberal conflation of heath and self-responsibility are also at work in the sense making frames that HIV positive men, who are also fathers, can variously deploy. Our analysis shows how this discursive mix can underpin possibilities of often conflicted meaning and identity when living as a man and father with HIV in the UK, and specifically how discourses of fatherhood and HIV ‘positive’ health can complicate these men’s expressions and inhabitations of masculinity.

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In cases involving unionization of graduate student research and teaching assistants at private U.S. universities, the National Labor Relations Board has, at times, denied collective bargaining rights on the presumption that unionization would harm faculty-student relations and academic freedom. Using survey data collected from PhD students in five academic disciplines across eight public U.S. universities, the authors compare represented and non-represented graduate student employees in terms of faculty-student relations, academic freedom, and pay. Unionization does not have the presumed negative effect on student outcomes, and in some cases has a positive effect. Union-represented graduate student employees report higher levels of personal and professional support, unionized graduate student employees fare better on pay, and unionized and nonunionized students report similar perceptions of academic freedom. These findings suggest that potential harm to faculty-student relationships and academic freedom should not continue to serve as bases for the denial of collective bargaining rights to graduate student employees.

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Volunteer administrators from 105 hospitals in five states in the northeast and southern United States provided open-ended survey responses about what they perceived to be the most pressing challenges and opportunities facing healthcare volunteer management. Taken together, these 105 hospitals used a total of 39,008 volunteers and 5.3 million volunteer hours during a 12-month period between 2010 and 2011. A qualitative content analysis of administrator responses suggests that primary challenges include volunteer recruitment and retention, administrative issues, and operational difficulties brought about by the current economic crisis. Key opportunities include more explicitly linking the volunteer function to hospital outcomes and community impact, expanding volunteer recruitment pools and roles and jobs, and developing organizational support for volunteers and making the volunteer management function more efficient and effective.

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This article uses strategic human resource management theory to consider the ways in which volunteers can potentially enhance hospital patient satisfaction. Results of a structural equation modeling analysis of multi-source data on 107 U.S. hospitals show positive associations between hospital strategy, volunteer management practices, volunteer workforce attributes, and patient satisfaction. Although no causality can be assumed, the results shed light on the volunteer–patient satisfaction relationship and have important implications for hospital leaders, volunteer administrators, and future research.