722 research outputs found

    Tracking the oxygen isotopic signature from the rainfall to the speleothems in Ortigosa de Cameros caves (La Rioja, Spain)

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    A one-year monitoring survey has been carried out in La Paz and La Viña Caves in the Ortigosa de Cameros Cave System (NE Iberian Peninsula), in order to track the oxygen isotope signal from rainfall to speleothem calcite, assessing the ability of this signal to retain environmental information. Oxygen isotope signals of rainfall events, drip water —sampled every three months—, and speleothem calcite, precipitated over three-months, are compared. Water dripping follows precipitation events in winter, spring and summer, more closely in the near-surface drip points than in the deeper ones. In autumn, dripping is delayed with respect to rainfall, suggesting that water stays in the epikarst before dripping resumes after summer. This delay causes a deviation of the total drip water signal (average δ<sup>18</sup>O=−8.39‰ V-SMOW) from the rainfall signal (average δ<sup>18</sup>O=−7.41‰ V-SMOW). On the contrary, in winter the isotopic signal of drip water keeps the rainfall signal. Calcite isotopic signal (total average δ<sup>18</sup>O=−6.83‰ V-PDB) shows a small offset (0.62–0.75%) with respect to the signal predicted by drip water oxygen composition; this points to a limited kinetic effect in calcite precipitation, therefore calcite retains the signal of rainfall, especially in winter.<br><br>Durante un año se han monitorizado las cuevas de La Paz y La Viña en el Sistema de Cuevas de Ortigosa de Cameros (NE de la Península Ibérica) para rastrear la señal isotópica del oxígeno desde la lluvia a la calcita espeleotémica, y así valorar la capacidad de esta señal para conservar información medioambiental. Se han comparado las señales isotópicas del oxígeno de los eventos de la lluvia, el agua de goteo (muestreada trimestralmente) y la calcita espeleotémica, precipitada también durante cada trimestre. El goteo en las cuevas responde a la precipitación en invierno, primavera y verano, más estrechamente en los puntos más próximos a la superficie que en los profundos. En otoño hay un retraso entre la lluvia y el goteo, lo que sugiere que el agua permanece por un tiempo en el epikarst, antes de que se reanude el goteo después del verano. Este retraso provoca que la señal isotópica del agua de goteo (media total de δ<sup>18</sup>O=−8.39‰ V-SMOW) se desvíe de la señal de la lluvia (media de δ<sup>18</sup>O=−7,41‰ V-SMOW). Por el contrario, en invierno la señal isotópica del agua de goteo es muy semejante a la de la lluvia. La composición isotópica de la calcita espeleotémica (media total de δ<sup>18</sup>O=−6,83‰ V-PDB) presenta un pequeño desfase (0,62–0,75%) respecto al valor que le correspondería por la composición isotópica del agua de goteo; esto indica que los efectos cinéticos durante la precipitación de la calcita son limitados, por lo que ésta conserva la señal de la lluvia, especialmente en invierno

    Proceso de construcci?n de una cultura de paz en los ni?os de transici?n de la instituci?n educativa Armando Romero Lozano de Sevilla Valle, a trav?s de estrategias did?cticas sensibilizadoras

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    121 p. Recurso Electr?nicoEl presente proyecto de investigaci?n ?proceso de construcci?n de una cultura de paz en los ni?os de preescolar, a trav?s de estrategias did?cticas sensibilizadoras? consiste en visibilizar los alcances en la mejora de las habilidades de resoluci?n de conflictos a trav?s de actividades l?dicas y art?sticas en los ni?os de preescolar de Instituci?n Educativa Armando Romero Lozano del municipio de Sevilla valle. Todo esto se realiz? partiendo del planteamiento de los objetivos, los cuales permitir?n lograr su cometido; en primer lugar, identificar a partir de los resultados qu? problem?ticas de comportamiento tienen los ni?os, en segundo lugar, implementar un plan de intervenci?n orientado a mejorar las relaciones interpersonales de los ni?os y en tercer lugar, evaluar el impacto generado con el plan de intervenci?n propuesto para tal fin. En cuanto al marco te?rico, se busc? el soporte en los postulados de diferentes autores, los cuales resultaron pertinentes para el abordaje conceptual de este, ya que hablan del desarrollo de la capacidad creadora, principios, normas y valores que hacen un clima escolar acorde para una educaci?n para la paz y una participaci?n democr?tica, como aspectos importantes a tener en cuenta en esta investigaci?n. Respecto a la metodolog?a, se desarroll? en base a la investigaci?n la investigaci?n acci?n-participativa y cooperativa, con un enfoque etnogr?fico, dentro del paradigma cualitativo. Tras esto, el resultado que se obtendr? del proceso estudiado, que junto a referentes te?ricos ayuda a explicar los procesos de la pr?ctica escolar estudiada.This research project process of building a culture of peace in preschool children through teaching strategies visible sensitizer is the scope in improving the skills of conflict resolution through recreational and artistic activities preschoolers educational institution Armando Romero Lozano the municipality of Seville valley. All this was done based on the approach of objectives, which will allow achieve its mission; first identified from the results which problematic behavior have children, secondly, implement an intervention plan aimed at improving interpersonal relationships of children and thirdly, to assess the impact generated with the intervention plan proposed for this purpose. As for the theoretical framework, support the propositions of different authors, which were relevant to the conceptual approach to this is sought, as they speak of the development of creativity, principles, norms and values that make a chord school climate for education for peace and democratic participation, as important aspects to consider in this research. Reading methodology was developed based on the research-participatory and cooperative action with an ethnographic approach, within the qualitative research paradigm. After this, the result you get the process under study, which together with theoretical framework helps explain the processes studied school practice Keywords: skills, peace, transition, norms, values and family

    Plan de negocio para la importaci?n y comercializaci?n de bicicletas, repuestos y accesorios en el mercado peruano

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    En el desarrollo del presente plan de negocio se determin? que el negocio de importaci?n y comercializaci?n de bicicletas, accesorios y repuestos en el mercado peruano es viable y rentable, ya que el valor actual neto (VAN) resulta ser de $20,562 y la tasa interna de retorno (TIR) de 14.25%, el cual supera al WACC (costo promedio de capital). Para lograr este escenario favorable y viable del negocio la empresa BIKELIFE deber? ejecutar los planes: estrat?gico, marketing, operaciones, recursos humanos y TI detallados en la presente tesis, que servir?n para la implementaci?n y buen funcionamiento de la empresa. De la misma forma se desarroll? las partes de la cadena de abastecimiento de tal forma de optimizar las operaciones en costo y tiempo

    Designability of alpha-helical Proteins

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    A typical protein structure is a compact packing of connected alpha-helices and/or beta-strands. We have developed a method for generating the ensemble of compact structures a given set of helices and strands can form. The method is tested on structures composed of four alpha-helices connected by short turns. All such natural four-helix bundles that are connected by short turns seen in nature are reproduced to closer than 3.6 Angstroms per residue within the ensemble. Since structures with no natural counterpart may be targets for ab initio structure design, the designability of each structure in the ensemble -- defined as the number of sequences with that structure as their lowest energy state -- is evaluated using a hydrophobic energy. For the case of four alpha-helices, a small set of highly designable structures emerges, most of which have an analog among the known four-helix fold families, however several novel packings and topologies are identified.Comment: 21 pages, 6 figures, to appear in PNA

    Producci?n y exportaci?n de mandarinas con variedades protegidas cultivadas en Salaverry- Trujillo, La Libertad para mercados de alto valor : plan de negocios para una nueva empresa

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    El presente trabajo tiene como objetivo principal demostrar la viabilidad econ?mica y financiera de implementar el cultivo de mandarinas de variedad protegida en la zona de Salaverry, el destino de esta producci?n es a mercados de alto valor. El proyecto contempla la siembra de 100 Has de mandarina de variedad Tango (protegida), teniendo como ventaja comparativa las excelentes condiciones agroecol?gicas de la zona de Salaverry (La Libertad) que le permiten acceder a mercados premium debido a la calidad obtenida

    Remarks on Semileptonic B and D Decays into Orbitally Excited Mesons

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    We have obtained the differential decay rate and calculated the branching ratios of the exclusive semileptonic decays B(D)→XlνB(D) \to Xl\nu, where XX is a p-wave meson, using the nonrelativistic ISGW quark model. Our results are compared with the predictions of the ISGW2 model. We have computed some branching ratios that were not reported or were reported with 0.00 in this model. For example, we find that Br(Bc−→Bs2∗0ˉl−νˉ)=4.03×10−5Br(B_c^- \to \bar{B_{s2}^{*0}}l^-\bar{\nu}) = 4.03 \times 10^{-5}, Br(Bc−→B2∗0ˉl−νˉ)=3.65×10−6Br(B_c^- \to \bar{B_2^{*0}}l^- \bar{\nu}) =3.65 \times 10^{-6} and Br(Ds+→f2l+ν)=2.7×10−5Br(D_s^+ \to f_2l^+\nu) = 2.7 \times 10^{-5}, which seems to be at the reach of forthcoming experiments. Furthermore, we have classified the Bu,d,s→TlνB_{u,d,s} \to Tl\nu decays in two groups and compared the semileptonic and nonleptonic decays including a tensor meson in the final state.Comment: 11 pages, LaTe

    Plan de negocio para la elaboraci?n de una bebida instant?nea saborizada a base de leche enriquecida con alb?mina de huevo en Lima Metropolitana

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    En el siguiente plan de negocios se plantea como objetivo principal determinar la viabilidad t?cnica, econ?mica y financiera para la producci?n y comercializaci?n de una bebida instant?nea saborizada a base de leche enriquecida con alb?mina de huevo en el mercado de Lima Metropolitana. Para el diagn?stico del entorno se utiliz? el an?lisis SEPTE y de cinco fuerzas de Porter evidenciando un entorno favorable para productos enriquecidos. El producto se presentar? en bolsas por 120g con las que se podr? preparar 1 Litro de bebida, adem?s en los sabores de Vainilla y Chocolate. Utilizando encuestas cualitativas y Focus group se determin? la intenci?n e intensidad del mercado y se segment? el mercado objetivo en los NSE B y C. Con este mercado se establece como meta posicionarse en un 4% del mismo, en funci?n de esto se dise?a la cadena de suministro, la cual consiste en un abastecimiento gestionado por la empresa, mientras las operaciones de producci?n, almacenamiento y distribuci?n son tercerizadas con una gesti?n de calidad para supervisarlas. Desarrollando esta operaci?n se obtienen en 5 a?os un VAN Financiero de S/. 449,622.92 y un TIR Financiero de 20.73% con un periodo de retorno del capital de 4 a?os y 3 meses

    Influence of Polymorphisms Involved in Platelet Activation and Inflammatory Response on Aspirin-Related Upper Gastrointestinal Bleeding: A Case-Control Study

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    Background: Despite the wide benefits of aspirin and its cost-effectiveness, aspirin prescriptions have been reduced due to idiosyncratic responses in susceptible individuals. Low-dose aspirin and single-nucleotide polymorphisms (SNPs) are independently associated with increased risk of gastrointestinal hemorrhage; however, to-date, no studies investigated the SNP-aspirin interaction effect on upper gastrointestinal hemorrhage (UGIH). Therefore, we aimed to evaluate the role of 25 SNPs in multiple genes involved in platelet activation, angiogenesis and inflammatory response in aspirin-related UGIH. Methods: A multicenter, full case-control study was conducted in patients exposed and unexposed to aspirin. Three hundred twenty-six cases diagnosed with UGIH were matched with 748 controls (1:3) by age, gender, health center, and recruitment date. Only adults of European origin were included. Participants were stratified by aspirin exposure and genotype [(Aspirin(-), wild-type), (Aspirin(+), wild-type), (Aspirin(+), genetic variation), (Aspirin(-), genetic variation)]. For each SNP, the Odds Ratio of UGIH and their 95% confidence intervals were estimated in each subgroup by using the generalized linear mixed models for dependent binomial variables. SNP-aspirin interaction effect was estimated through Relative Excess Risk due to Interaction (RERI) measures. Results: We observed two categories of SNPs that might modify the risk magnitude of UGIH in aspirin consumers. Seven SNPs (rs1387180 A > G, rs2238631 T > C, rs1799964 T > C, rs5050 T > C/T > G, rs689466 T > C, rs1799983 T > A/T > G, and rs7756935 C > A) were "positive modifiers" associated with an excess of risk from aspirin exposure and carrying that genetic variation (1.75 T, rs1131882 G > A, rs4311994 C > T, rs10120688 G > A, rs4251961 T > C, rs3778355 G > C, rs1330344 C > T, rs5275 A > G/A > T, and rs3779647 C > T) were "negative modifiers" and associated with a reduced risk in aspirin users (-2.74 </= RERI </= -0.95). Conclusion: This preliminary study suggests that polymorphisms in genes involved in platelets activity, angiogenesis and inflammatory response might modify the risk of aspirin-related UGIH. Further studies with larger sample size and in different populations are needed to confirm our findings. If confirmed, this might have great impact on public health, thanks to aspirin's prophylactic properties in diseases of high incidence and severity

    Non-Hermitian SUSY Hydrogen-like Hamiltonians with real spectra

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    It is shown that the radial part of the Hydrogen Hamiltonian factorizes as the product of two not mutually adjoint first order differential operators plus a complex constant epsilon. The 1-susy approach is used to construct non-hermitian Hamiltonians with hydrogen spectra. Other non-hermitian Hamiltonians are shown to admit an extra `complex energy' at epsilon. New self-adjoint hydrogen-like Hamiltonians are also derived by using a 2-susy transformation with complex conjugate pairs epsilon, (c.c) epsilon.Comment: LaTeX2e file, 13 pages, 6 EPS figures. New references added. The present is a reorganized and simplified versio

    3D magnetic configuration of ferrimagnetic multilayers with competing interactions visualized by soft X ray vector tomography

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    Full control of magnetic properties in exchange coupled systems requires a good understanding of 3D magnetic configuration with lateral and in depth resolution. Here we show results from a soft X ray tomographic reconstruction which allow determining, solely from the experimental data, a detailed description of the vector magnetic configuration of a ferrimagnetic Gd12Co88 Nd17Co83 Gd24Co76 trilayer with engineered competing anisotropy, exchange and magneto static interactions at different depths. The trilayer displays chevron patterns with a distorted closure structure. Near the top Gd24Co76 layer, local exchange springs with out of plane magnetization reversal, quasi domains with ripple like patterns and magnetic vortices and antivortices across the thickness are observed. The detailed analysis of the magnetic tomogram shows that the effective strength of the exchange spring at the NdCo GdCo interface can be finely tuned by GdxCo1 x composition and anisotropy determined by sample fabrication and in plane stripe orientation adjustable , demonstrating the suitability of 3D magnetic visualization techniques in magnetic engineering researc
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