947 resultados para TIPS-pentacene


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These slides give general tips on exam technique in the context of feedback from a previous exam the students took

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Speaker: Lynda Hardman Organiser: Time: 04/02/2015 12:30-13:30 Location: B32/3077 Abstract The challenges of addressing gender inequalities in science, technology, engineering, mathematics and medicine is widely acknowledged. We currently hold a bronze award and ECS is one of many academic units in the University which has gained Athena Swan Charter status. In this seminar, Professor Lynda Hardman, Chair of the Informatics Europe working group "Women in Informatics Research and Education” will be explaining the causes of issued underlying gender inequality and constructive routes to addressing this important agenda. In undertaking to commit to an action plan which is a prerequisite of gaining charter status, the University or academic department agreed to accept and incorporate the Athena Swan six principles listed below: * To address gender inequalities requires commitment and action from everyone, at all levels of the organisation * To tackle the unequal representation of women in science requires changing cultures and attitudes across the organisation * The absence of diversity at management and policy-making levels has broad implications which the organisation will examine * The high loss rate of women in science is an urgent concern which the organisation will address * The system of short-term contracts has particularly negative consequences for the retention and progression of women in science, which the organisation recognises * There are both personal and structural obstacles to women making the transition from PhD into a sustainable academic career in science, which require the active consideration of the organisation. This seminar is designed to provide an opportunity to explore these issues NOTE: Lynda will be basing here talk on some of the work she directed as chair of the "Women in Informatics Research and Education” working group. The purpose of the working group is to actively participate and promote actions that contribute to improve gender balance in Information and Communication Sciences and Technologies. The first concrete result of the working group's activities was the publication of the booklet "More Women in Informatics Research and Education" in 2013. The booklet is a compact source of clear and simple best practices to deans and heads of departments that aim to increase the participation of women as both students and employees in their institutions. Many tips included were also inspired by colleagues already in leading positions who have already implemented actions in their institutions to attract more women and ensure their continued participation in the organization at commensurate ratios with their male colleagues. The booklet is endorsed by the European Commission and features a foreword by Neelie Kroes, Vice-President of the European Commission, responsible for the Digital Agenda.

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In this session we'll explore how Microsoft uses data science and machine learning across it's entire business, from Windows and Office, to Skype and XBox. We'll look at how companies across the world use Microsoft technology for empowering their businesses in many different industries. And we'll look at data science technologies you can use yourselves, such as Azure Machine Learning and Power BI. Finally we'll discuss job opportunities for data scientists and tips on how you can be successful!

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Introducción A pesar de que los nevos melanocíticos son un motivo de consulta frecuente en nuestra población no existen estudios a nivel de Colombia acerca de su tratamiento, a nivel mundial existe muy poca literatura al respecto por lo que hay un vacío conceptual en este campo. Objetivos Evaluar los cambios en cuanto a la presencia de pigmento y cicatrización, en los nevos melanocíticos adquiridos tratados con láser, basados en la experiencia de un solo centro en Bogotá. Materiales y métodos Es un estudio observacional de antes y después, en una cohorte histórica, de 90 casos de nevos melanocíticos adquiridos, tratados con láser en Uniláser Medica, en los que se evaluó la presencia de pigmento, cicatrización, y otras variables, con un control realizado a no menos de 3 meses de la intervención. Resultados Se encontró un rango de edad entre los 18 -51 años, promedio 27,59 años; fototipo de III-V; en el 32% de los casos, solo fue requerida una sesión de láser de Co2 y Erbio, para el aclaramiento completo de la misma. La duración del eritema en el 54,4% los casos fue de 1 a 3 meses. En un 64,4% quedó pigmento residual al control, pero de éstos casos el 48,2% fue entre un 5 a un 10% del inicial. El 58,9% hizo cicatriz, de éstos el 63% fue estética. La satisfacción por parte de los pacientes es alta a pesar de la persistencia pigmentaria y/o la presencia de cicatriz. Discusión El tratamiento de nevos melanocíticos adquiridos con láser es una opción terapéutica que genera cambios estadísticamente significativos en cuanto a pigmento, cicatriz estética y alta satisfacción por parte de los pacientes. Se requieren estudios, analíticos, para determinar eficacia del tratamiento.

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El fin de la Guerra Fría supuso no sólo el triunfo del capitalismo y de la democracia liberal, sino un cambio significativo en el Sistema Internacional; siendo menos centralizado y más regionalizado, como consecuencia de la proximidad y relaciones de interdependencia entre sus actores (no sólo Estados) y permitiendo la formación de Complejos Regionales de Seguridad (CRS). Los CRS son una forma efectiva de relacionarse y aproximarse a la arena internacional pues a través de sus procesos de securitización y desecuritización consiguen lograr objetivos específicos. Partiendo de ello, tanto la Unión Europea (UE) como la Comunidad para el Desarrollo de África Austral (SADC) iniciaron varios procesos de securitización relacionados con la integración regional; siendo un ejemplo de ello la eliminación de los controles en sus fronteras interiores o libre circulación de personas; pues consideraron que de no hacerse realidad, ello generaría amenazas políticas (su influencia y capacidad de actuación estaban amenazadas), económicas (en cuanto a su competitividad y niveles básicos de bienestar) y societales (en cuanto a la identidad de la comunidad como indispensable para la integración) que pondrían en riesgo la existencia misma de sus CRS. En esta medida, la UE creó el Espacio Schengen, que fue producto de un proceso de securitización desde inicios de la década de los 80 hasta mediados de la década de los 90; y la SADC se encuentra inmersa en tal proceso de securitización desde 1992 hasta la actualidad y espera la ratificación del Protocolo para la Facilitación del Movimiento de personas como primer paso para lograr la eliminación de controles en sus fronteras interiores. Si bien tanto la UE como la SADC consideraron que de no permitir la libre circulación de personas, su integración y por lo tanto, sus CRS estaban en riesgo; la SADC no lo ha logrado. Ello hace indispensable hacer un análisis más profundo de sus procesos de securitización para así encontrar sus falencias con respecto al éxito de la UE. El análisis está basado en la Teoría de los Complejos de Seguridad de Barry Buzan, plasmada en la obra Security a New Framework for Analysis (1998) de Barry Buzan, Ole Waever y Jaap de Wilde y será dividido en cada una de las etapas del proceso de securitización: la identificación de una amenaza existencial a un objeto referente a través de un acto discursivo, la aceptación de una amenaza por parte de una audiencia relevante y las acciones de emergencia para hacer frente a las amenazas existenciales; reconociendo las diferencias y similitudes de un proceso de securitización exitoso frente a otro que aún no lo ha sido.

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Las estrategias tendientes a la diversificación de los mercados de exportación e internacionalización de la economía por parte del gobierno colombiano y sus políticas gubernamentales han incluido la firma de una serie de Tratados de Libre Comercio, entre ellos el TLC de última generación firmado con El Estado de Israel. Estos tratados además de abordar temas tradicionales de comercio, tratan nuevos capítulos en inversiones y servicios. Así mismo se analizan las principales políticas por parte del gobierno de Israel para la competitividad en términos empresariales y sociales. Más adelante se consideran aspectos generales de la economía colombiana y se analiza la relación comercial bilateral entre el Estado de Israel y la República de Colombia para entender su comportamiento histórico y el ambiente actual. Finalmente se hace un énfasis en el sector agrícola de Israel y sus aspectos que lo han dirigido al éxito, una observación corta del sector en Colombia y luego aspectos adicionales para a facilitación del comercio con Israel. El estudio va dirigido a empresarios, compañías o entes públicos a nivel local e internacional que vean en el sector agrícola colombiano una oportunidad de desarrollo, aprovechando los beneficios de comercio y conocimiento, con el objetivo de mejorar la competitividad y productividad del sector en Colombia. Se utilizan metodologías tanto cuantitativas como cualitativas para la investigación y análisis de caso tomando la información correspondiente de fuentes verídicas e independientes para así poder reseñar y describir las oportunidades y retos del sector agrícola.

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Una de las mayores brechas que tienen los empresarios colombianos es la falta de información sobre las opciones de exportación hacia otros países, especialmente con Estados Unidos siendo uno de los principales socios comerciales que tiene Colombia. Por esta razón el presente trabajo de investigación se propuso identificar y analizar las oportunidades de exportaciones de productos agrícolas y agro-industriales potenciales desde Colombia hacia Estados Unidos en el periodo de 2003 hasta 2012. Después de contextualizar el entorno de los dos países así como el del sector agrícola de cada uno de ellos; se procedió a la selección de diez sub-partidas arancelarias a través de las bases de datos de TRADE MAP y UN COMTRADE. Con base en los resultados observados, se eligieron los dos productos agrícolas o agro-industriales potenciales para la exportación hacia Estados Unidos; adicionalmente se exploró el Tratado de Libre Comercio con dicho país para reconocer las ventajas, beneficios y oportunidades que este acuerdo generó en los productos seleccionados. Por lo tanto se concluye que Estados Unidos influye significativamente en las relaciones tanto comerciales como financieras a nivel mundial. En el caso de Colombia ha alcanzado resultados positivos en la balanza comercial, niveles óptimos de inversión y crecimiento de la economía comercial. Finalmente se puede afirmar que el Tratado de Libre Comercio entre los dos países promueve el ingreso preferencial de manera permanente, genera mayor estabilidad, competitividad en el largo plazo y acceso a mercados al agilizar los procesos normativos de los productos agrícolas y agro-industriales.

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Partiendo de la premisa que las microempresas familiares están en auge por la formación emprendedora a la que se está dando énfasis en las universidades en la ciudad de Quito, la finalidad de este estudio es conocer las características del perfil que deben tener estas microempresas así como los factores que limitan su crecimiento y los factores claves que piensan los microempresarios y otros tips que deberían toman en cuenta en el día a día de sus negocios. La microempresa es uno de los pilares fundamentales en la economía de las naciones y más en países como el nuestro en donde los lazos familiares son tan arraigados que llevan a cometer errores en la dirección de empresas por quedar bien con los familiares o simplemente por dar oportunidades a la familia ubicándolos en lugares en los que no poseen la experiencia necesaria para tomar decisiones en pro de la empresa. En el primer capítulo analizaremos el marco teórico de la presente tesis que ayudará al lector a entender un poco más sobre el tema del escrito. Como segundo capítulo conoceremos la evolución que ha tenido la microempresa familiar en la ciudad de Quito a través de los datos obtenidos en las entrevistas y encuestas realizadas a los microempresarios. En el tercer capítulo identificaremos los factores que limitan el crecimiento de la microempresa familiar, además de la sucesión y la transición en la empresa. Por último determinaremos las claves de éxito para el crecimiento de las microempresas familiares; 4 factores muy importantes para que la empresa perdure a través del tiempo y generaciones.

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Throughout the central nervous system a dominant form of inhibition of neurotransmitter release from presynaptic terminals is mediated by G-protein-coupled receptors (GPCRs). Neurotransmitter release is typically induced by action potentials (APs), but can also occur spontaneously. Presynaptic inhibition by GPCRs has been associated with modulation of voltage-dependent ion channels. However, electrophysiological recordings of spontaneous, AP-independent (so-called ‘miniature’) postsynaptic events reveal an additional, important form of GPCR-mediated presynaptic inhibition, distinct from effects on ionic conductances and consistent with a direct action on the vesicle release machinery. Recent studies suggest that such miniature events might be of physiological relevance not only in signalling but also in development. In the cerebellum, neurotransmitter release onto Purkinje cells occurs by AP-dependent and AP-independent pathways. Here, I focus on inhibitory synapses between interneurons and Purkinje cells, which are subject to strong, identifiable regulation by endogenous GPCR agonists, to consider mechanisms of GPCR-mediated presynaptic inhibition.

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The translocation of C and N in a maize-Striga hermonthica association was investigated at three rates of nitrogen application in a glasshouse experiment. The objectives were to measure the transfer of C and N from maize to S. hermonthica and to determine whether the amount of N in the growing medium affected the proportions of C and N transferred. Young plants of maize were labelled in a (CO2)-C-13 atmosphere and leaf tips were immersed in ((NH4)-N-15)(2)SO4 Solution. The Striga x N interaction was not significant for any of the responses measured. Total dry matter for infected maize was significantly smaller than for uninfected maize from 43 to 99 days after planting, but N application increased total dry matter at all sampling times. Infected maize plants partitioned 39-45 % of their total dry matter to the roots compared with 28-31 % for Uninfected maize. Dry matter of S. hermonthica was not affected by the rate of N applied. S. hermonthica derived 100 % of its carbon from maize before emergence, decreasing to 22-59 % thereafter; the corresponding values for nitrogen were up to 59 % pre-emergence and Lip to 100 % after emergence. The relative proportions of nitrogen depleted from the host (up to 10 %) were greater than those of carbon (maximum 1.2 %) at all times of sampling after emergence of the parasite. The results show that the parasite was more dependent on the host for nitrogen than for carbon.

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The translocation of C and N in a maize-Striga hermonthica association was investigated at three rates of nitrogen application in a glasshouse experiment. The objectives were to measure the transfer of C and N from maize to S. hermonthica and to determine whether the amount of N in the growing medium affected the proportions of C and N transferred. Young plants of maize were labelled in a (CO2)-C-13 atmosphere and leaf tips were immersed in ((NH4)-N-15)(2)SO4 Solution. The Striga x N interaction was not significant for any of the responses measured. Total dry matter for infected maize was significantly smaller than for uninfected maize from 43 to 99 days after planting, but N application increased total dry matter at all sampling times. Infected maize plants partitioned 39-45 % of their total dry matter to the roots compared with 28-31 % for Uninfected maize. Dry matter of S. hermonthica was not affected by the rate of N applied. S. hermonthica derived 100 % of its carbon from maize before emergence, decreasing to 22-59 % thereafter; the corresponding values for nitrogen were up to 59 % pre-emergence and Lip to 100 % after emergence. The relative proportions of nitrogen depleted from the host (up to 10 %) were greater than those of carbon (maximum 1.2 %) at all times of sampling after emergence of the parasite. The results show that the parasite was more dependent on the host for nitrogen than for carbon.

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The suitability of cryopreservation for the secure, long-term storage of the rare and endangered species Cosmos atrosanguineus was investigated. Using encapsulation/dehydration of shoot tips in alginate strips, survival rates of up to 100 % and shoot regeneration of up to 35 % were achieved. Light and electron microscopy studies indicated that cellular damage to some regions of the shoot tip during the freeze/thaw procedure was high, although cell survival in and around the meristematic region allowed shoot tip regeneration. The genetic fingerprinting technique, amplified fragment length polymorphisms (AFLPs), showed that no detectable genetic variation was present between material of C. atrosanguineus at the time of initiation into tissue culture and that which had been cryopreserved, stored in liquid nitrogen for 12 months and regenerated. Wearied plantlets that were grown under glasshouse conditions exhibited no morphological variation from non-frozen controls. (C) 2003 Annals of Botany Company.

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Despite advances in tissue culture techniques, propagation by leafy, softwood cuttings is the preferred, practical system for vegetative reproduction of many tree and shrub species. Species are frequently defined as 'difficult'- or 'easy-to-root' when propagated by conventional cuttings. Speed of rooting is often linked with ease of propagation, and slow-to-root species may be 'difficult' precisely because tissues deteriorate prior to the formation of adventitious roots. Even when roots form, limited development of these may impair the establishment of a cutting. In this study we used softwood cuttings of cashew (Anacardium occidentale), a species considered as 'difficult-to-root'. We aimed to test the hypothesis that speed, and extent of early rooting, is critical in determining success with this species; and that the potential to form adventitious roots will decrease with time in the propagation environment. Using two genotypes, initial rooting rates were examined in the presence or absence of exogenous auxin. In cuttings that formed adventitious roots, either entire roots or root tips were removed, to determine if further root formation/development was feasible. To investigate if subsequent root responses were linked to phytohormone action, a number of cuttings were also treated with either exogenous auxin (indole-3-butyric acid-IBA) or cytokinin (zeatin). Despite the reputation of Anacardium as being 'difficult-to-root', we found high rooting rates in two genotypes (AC 10 and CCP 1001). Removing adventitious roots from cuttings and returning them to the propagation environment, resulted in subsequent re-rooting. Indeed, individual cuttings could develop new adventitious roots on four to five separate occasions over a 9 week period. Data showed that rooting potential increased, not decreased with time in the propagation environment and that cutting viability was unaffected. Root expression was faster (8-15 days) after the removal of previous roots compared to when the cuttings were first stuck (21 days). Exposing cuttings to IBA at the time of preparation, improved initial rooting in AC 10, but not in CCP 1001. Application of IBA once roots had formed had little effect on subsequent development, but zeatin reduced root length and promoted root number and dry matter accumulation. These results challenge our hypothesis, and indicate that rooting potential remains high in Anacardium. The precise mechanisms that regulate the number of adventitious roots expressed, remain to be determined. Nevertheless, results indicate that rooting potential can be high in 'difficult-to-root' species, and suggest that providing supportive environments is the key to expressing this potential. (c) 2006 Elsevier B.V. All rights reserved.

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The translocation of C and N in a maize-Striga hermonthica association was investigated at three rates of nitrogen application in a glasshouse experiment. The objectives were to measure the transfer of C and N from maize to S. hermonthica and to determine whether the amount of N in the growing medium affected the proportions of C and N transferred. Young plants of maize were labelled in a (CO2)-C-13 atmosphere and leaf tips were immersed in ((NH4)-N-15)(2)SO4 Solution. The Striga x N interaction was not significant for any of the responses measured. Total dry matter for infected maize was significantly smaller than for uninfected maize from 43 to 99 days after planting, but N application increased total dry matter at all sampling times. Infected maize plants partitioned 39-45 % of their total dry matter to the roots compared with 28-31 % for Uninfected maize. Dry matter of S. hermonthica was not affected by the rate of N applied. S. hermonthica derived 100 % of its carbon from maize before emergence, decreasing to 22-59 % thereafter; the corresponding values for nitrogen were up to 59 % pre-emergence and Lip to 100 % after emergence. The relative proportions of nitrogen depleted from the host (up to 10 %) were greater than those of carbon (maximum 1.2 %) at all times of sampling after emergence of the parasite. The results show that the parasite was more dependent on the host for nitrogen than for carbon.

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The suitability of cryopreservation for the secure, long-term storage of the rare and endangered species Cosmos atrosanguineus was investigated. Using encapsulation/dehydration of shoot tips in alginate strips, survival rates of up to 100 % and shoot regeneration of up to 35 % were achieved. Light and electron microscopy studies indicated that cellular damage to some regions of the shoot tip during the freeze/thaw procedure was high, although cell survival in and around the meristematic region allowed shoot tip regeneration. The genetic fingerprinting technique, amplified fragment length polymorphisms (AFLPs), showed that no detectable genetic variation was present between material of C. atrosanguineus at the time of initiation into tissue culture and that which had been cryopreserved, stored in liquid nitrogen for 12 months and regenerated. Weaned plantlets that were grown under glasshouse conditions exhibited no morphological variation from non-frozen controls.