Non-volatility of ferroelectric SBT thin fims, at 75ºC

[ES] El estudio de la no volatilidad de una memoria FeRAM de tantalato de bismuto y estroncio, SrBi2Ta2O9 (SBT) en condiciones reales de uso, requiere la caracterización ferroeléctrica del material en forma de lámina delgada a temperaturas por encima del ambiente. Para ello se han depositado láminas de SBT mediante un método sol-gel, sobre substratos de Pt/TiO2/SiO2/Si(100), seleccionándose condensadores de área 5.10-4 cm-2. Basándonos en las medidas de la variación de la polarización con el tiempo (retención) realizadas a temperatura ambiente y a 75ºC, analizamos la viabilidad del material como una FeRAM en condiciones reales de uso.[EN] The study of the non-volatility of Strontium bismuth tantalate SrBi2Ta2O9 (SBT) FeRAM memory, at real operating conditions, requires the ferroelectric characterisation of the material, as a thin film, above the room temperature.As a result, it has been deposited SBT films by the sol-gel method, onto Pt/TiO2/SiO2/Si (100) substrates, using capacitors of 5 x 10–4 cm-2 .In this work, we analysed the viability of this material as a FeRAM memory in real operating conditions, as a result of the variation of the polarisation measurements with time (retention), performed at room temperature and 75ºC.Este trabajo ha sido realizado con el apoyo del proyecto de la CICYT MAT98-1068.Peer reviewe

Feasibility of (Pb, Ca)TiO3 thin films deposited on Pt/TiO2/SiO2/Si(100) for switching applications

[ES] Se han depositado láminas delgadas de (Pb,Ca)TiO3 sobre substratos de Pt/TiO2/SiO2/Si(100) por centrifugación, partiendo de soluciones sintetizadas por sol -gel. La concentración de las soluciones y el contenido de PbO se seleccionaron para minimizar las tensiones de las láminas cristalizadas y obtener la adecuada estequiometria. La cristalización mediante un calentamiento rápido (RTP), conduce a láminas con orientaciones preferentes [001]/[001], reducida capa interfacial ferroeléctrico-Pt y composición deseada. Los parámetros ferroeléctricos obtenidos muestran una mejora de las propiedades. Estas láminas presentan una fatiga y envejecimiento mucho más moderados que otros materiales alternativos depositados sobre substratos iguales, lo que permite considerar al método descrito como muy valioso para conseguir materiales susceptibles de emplear en aplicaciones de conmutación.[EN] (Pb,Ca)TiO3 ferroelectric thin films have been spin-coated on Pt/TiO2/SiO2/Si(100) substrates from sol-gel synthesized solutions. Selecting the solution concentrations and the excess of PbO content, stoichiometric composicion with reduced strains are obtained. Crystallization process by rapid thermal treatment (RTP) promote preferred orientations [001]/[100] resulting a thiner ferroelectric-platinum interface layer, which causes the improvement of fatigue and retain behaviour, despite the use of platinum electrodes. These experimental finds let to cosider the described methode of processing very convenient to prepare thin films of this composition to use on switching applications such as non volatil RAM memories.Peer reviewe

Does she think it matters who makes more? Perceived differences in types of relationship arguments among female breadwinners and non-breadwinners

This mixed methods study used a sequential exploratory design and Becker’s (1973) Theory of Marriage to explore how female breadwinners and non-breadwinners perceive types of relationship arguments. Respondents completed an online survey targeted to women about money and relationships. Qualitative analyses using a multiple case study approach explored the contents of arguments among three groups: women who earn more than their partner/spouse, women who earn less, and women who earn the same. Quantitative analyses employed independent t-tests to identify differences between female breadwinners and non-breadwinners for variables related to the identified themes from the qualitative analyses. Findings from this mixed methods study suggest that female breadwinners tend to perceive their partners as not meeting their expectations, are more likely to use blame language, and are less likely to use “togetherness” language when describing relationship arguments. Implications for future research and practice are provided

Extracción con líquidos presurizados para la obtención de fracciones antioxidantes y anti-inflamatorias a partir de la microalga Isochrysis galbana

Trabajo presentado a las I Jornadas Científicas del CIAL celebradas el 5 de junio de 2014 en Madrid.Las microalgas son consideradas como una fuente innovadora para el desarrollo de nuevos productos alimentarios y farmacéuticos debido a su alto contenido en moléculas de alto interés biológico, como ácidos grasos, carotenoides, vitaminas, esteroles, polisacáridos y compuestos fenólicos. Este contenido en moléculas bioactivas se ha relacionado con efectos funcionales beneficiosos para la salud, como consecuencia, por ejemplo, de su efecto antioxidante y anti-inflamatorio. En los últimos años se han empleado nuevos métodos de extracción para la obtención de dichos compuestos de interés mediante tecnologías medioambientalmente limpias, entre las que cabe destacar la extracción con líquidos presurizados (PLE). En este trabajo se ha llevado a cabo la extracción de la fracción fenólica de la microalga Isochrysis galbana mediante PLE. Para obtener un extracto de alto contenido en compuestos fenólicos, se realizó un diseño experimental (3^2) estudiando el efecto de la temperatura y el porcentaje de etanol en el disolvente, factores influyentes en el proceso de extracción PLE. Las variables respuesta fueron rendimiento de extracción (%), contenido de fenoles totales y actividad antioxidante. Por último, se llevo a cabo la extracción PLE con las condiciones optimizadas marcadas por el diseño experimental para la obtención de un extracto rico en compuestos fenólicos. Los extractos obtenidos se caracterizaron funcionalmente en términos de actividad anitioxidante y actividad anti-inflamatoria.M.H. agradece al MICINN su contrato de investigación “Ramón y Cajal”. I.L-E. agradece al CSIC por su contrato JAE-DOC. Los autores agradecen la financiación del proyecto “MIRACLES - Multi-product Integrated bioRefinery of Algae: from Carbon dioxide and Light Energy to high-value Specialties (KBBE-613588)”.Peer reviewe

The resident-as-teacher educational challenge: a needs assessment survey at the National Autonomous University of Mexico Faculty of Medicine

<p>Abstract</p> <p>Background</p> <p>The role of residents as educators is increasingly recognized, since it impacts residents, interns, medical students and other healthcare professionals. A widespread implementation of resident-as-teacher courses in developed countries' medical schools has occurred, with variable results. There is a dearth of information about this theme in developing countries. The National Autonomous University of Mexico (UNAM) Faculty of Medicine has more than 50% of the residency programs' physician population in Mexico. This report describes a needs assessment survey for a resident as teacher program at our institution.</p> <p>Methods</p> <p>A cross-sectional descriptive survey was developed based on a review of the available literature and discussion by an expert multidisciplinary committee. The goal was to identify the residents' attitudes, academic needs and preferred educational strategies regarding resident-as-teacher activities throughout the residency. The survey was piloted and modified accordingly. The paper anonymous survey was sent to 7,685 residents, the total population of medical residents in UNAM programs in the country.</p> <p>Results</p> <p>There was a 65.7% return rate (5,186 questionnaires), a broad and representative sample of the student population. The residents felt they had knowledge and were competent in medical education, but the majority felt a need to improve their knowledge and skills in this discipline. Most residents (92.5%) felt that their role as educators of medical students, interns and other residents was important/very important. They estimated that 45.5% of their learning came from other residents. Ninety percent stated that it was necessary to be trained in teaching skills. The themes identified to include in the educational intervention were mostly clinically oriented. The educational strategies in order of preference were interactive lectures with a professor, small groups with a moderator, material available in a website for self-learning, printed material for self-study and homework, and small group web-based learning.</p> <p>Conclusions</p> <p>There is a large unmet need to implement educational interventions to improve residents' educational skills in postgraduate educational programs in developing countries. Most perceived needs of residents are practical and clinically oriented, and they prefer traditional educational strategies. Resident as teachers educational interventions need to be designed taking into account local needs and resources.</p

Participaci?n competitiva en las subastas RER: estrategia basada en la teor?a de opciones reales

Las energ?as o recursos energ?ticos renovables (RER) son una de las alternativas para reducir la emisi?n de gases de efecto invernadero, una de las causas de los cambios clim?ticos, y al mismo tiempo, un mercado en expansi?n vigorosa en la ?ltima d?cada, relevante para la atracci?n de inversiones y la generaci?n de empleos. El principal mecanismo de promoci?n de las energ?as renovables en el Per? son las subastas, instrumentos que permiten obtener resultados eficientes a partir de la competencia entre los postores. En el Per?, la estructura de las subastas RER es similar a la estructura de una composici?n de distintas opciones de compra financieras (call options) e involucra una secuencia de decisiones similares, respecto al pago de primas para adquisici?n de derechos de decisi?n en fechas establecidas, a aquellas asociadas al citado instrumento financiero derivativo. Por ello, en esta investigaci?n se trata de establecer si se puede utilizar la teor?a de las opciones reales (TOR) para comprender la racionalidad de invertir en un proyecto con gran incertidumbre respecto del VAN, como los elaborados para participar en una subasta RER. As?, en este trabajo se eval?an las estrategias que utilizaron los postores de proyectos e?licos en la cuarta subasta RER promovida por el Gobierno peruano, y la consecuente adjudicaci?n lograda para algunos de sus proyectos. Espec?ficamente, sobre la base de las opciones reales y considerando las garant?as requeridas, se trata de inferir la estrategia utilizada por una de las empresas postoras. Se pretende ayudar a los postores y a los reguladores a utilizar la teor?a de opciones reales para formular estrategias competitivas m?s eficientes en las pr?ximas subastas RER. Los postores podr?an desarrollar estrategias para aumentar su probabilidad de adjudicaci?n a un costo de participaci?n proporcionalmente m?s bajo, y los reguladores podr?an mejorar la definici?n de las garant?as de seguridad de la oferta y de fiel cumplimiento

Seed-set evaluation of four male-sterile, female-fertile soybean lines using alfalfa leafcutting bees and honey bees as pollinators

Male-sterile, female-fertile plants were used to produce hybrid soybean seed. Manual cross-pollination using male-sterile plants to produce large quantities of hybrid seed is difficult and time-consuming because of the low success rate in cross-pollination. Insect pollinators may be suitable vectors to transfer pollen, but the most suitable vector for pollen transfer from the male parent to the female parent has not been identified for soybean. The objective of the present study was to evaluate seed-set on four male-sterile, female-fertile soybean lines by using alfalfa leafcutting bees (Megachile rotundata (F.)) and honey bees (Apis mellifera (L.)) as pollinators. Seed-set was evaluated in summers 2003 and 2005 near Ames, Iowa, USA and in summers 2003, 2004, and 2005 near Wooster, Ohio, USA. Neither the effect of pollinator species nor the interaction effect of pollinator species×location was significant for any year. Honey bees performed similarly to alfalfa leafcutting bees at both locations. The results indicated significant differences for seed-set among male-sterile lines, suggesting preferential pollination. Male-sterile lines, ms1(Urbana) and ms2 (Ames 2), had higher cross-pollinated seed-set compared to ms6 (Ames 1), and ms6 (Corsoy 79). At the Ames location, ms1ms1 (Urbana) plants had the highest seed-set (50·16 seeds per male-sterile plant in 2005). At the Wooster location, ms1ms1 (Urbana) plants also had the highest seed-set (92·04 seeds per male-sterile plant) in 2005. Costs and local conditions need to be addressed to support the choice of either pollinator species as a pollination vector to produce hybrid soybean seed

El mercado alternativo de valores como mecanismo de financiamiento para la mediana empresa : propuesta normativa de mejora

Para lograr el desarrollo de un pa?s se requiere la mejora del sector empresarial en su conjunto, es decir, de todos sus tipos de empresas. Uno de los factores claves de ?xito en el Per? es el acceso al financiamiento, y como es sabido la gran empresa tiene sus propios mecanismos, y la peque?a y microempresa goza de un r?gimen promocional especial, pero ?qu? ocurre con la mediana empresa? Ante esta situaci?n, en el 2012 el Gobierno peruano aprob? el Reglamento del Mercado Alternativo de Valores (MAV) con la finalidad de fortalecer y fomentar el crecimiento empresarial mediante mecanismos que permitan acceder al financiamiento a menores costos y mayores plazos, la ampliaci?n de la oferta de instrumentos en el mercado, la mejora de la competitividad en la regi?n y la promoci?n del acceso de empresas de menor tama?o al mercado de valores. Precisamente, el MAV constituye un mercado alternativo para el desarrollo de la mediana empresa, ya que representa una opci?n para la obtenci?n de un mayor financiamiento. Por ello, la presente investigaci?n persigue el objetivo de analizar el MAV para establecer las causas de su limitado crecimiento y presentar una propuesta que impulse su desarrollo, tomando como referencia la legislaci?n comparada de diversos pa?ses con similares experiencias, como Espa?a, Colombia, Chile e Inglaterra

Transcriptional Regulator CNOT3 Defines an Aggressive Colorectal Cancer Subtype.

Cancer cells exhibit dramatic alterations of chromatin organization at cis-regulatory elements, but the molecular basis, extent, and impact of these alterations are still being unraveled. Here, we identify extensive genome-wide modification of sites bearing the active histone mark H3K4me2 in primary human colorectal cancers, as compared with corresponding benign precursor adenomas. Modification of certain colorectal cancer sites highlighted the activity of the transcription factor CNOT3, which is known to control self-renewal of embryonic stem cells (ESC). In primary colorectal cancer cells, we observed a scattered pattern of CNOT3 expression, as might be expected for a tumor-initiating cell marker. Colorectal cancer cells exhibited nuclear and cytoplasmic expression of CNOT3, suggesting possible roles in both transcription and mRNA stability. We found that CNOT3 was bound primarily to genes whose expression was affected by CNOT3 loss, and also at sites modulated in certain types of colorectal cancers. These target genes were implicated in ESC and cancer self-renewal and fell into two distinct groups: those dependent on CNOT3 and MYC for optimal transcription and those repressed by CNOT3 binding and promoter hypermethylation. Silencing CNOT3 in colorectal cancer cells resulted in replication arrest. In clinical specimens, early-stage tumors that included >5% CNOT3(+) cells exhibited a correlation to worse clinical outcomes compared with tumors with little to no CNOT3 expression. Together, our findings implicate CNOT3 in the coordination of colonic epithelial cell self-renewal, suggesting this factor as a new biomarker for molecular and prognostic classification of early-stage colorectal cancer. Cancer Res; 77(3); 766-79. ©2016 AACR