Comovimientos entre mercados OCDE y el petróleo: enfoque intensidad condicional en valores extremos

42 p.En esta investigación analizamos el grado de comovimiento que existe en los eventos extremos entre los mercados de valores en las principales potencias de la organización para la cooperación y el desarrollo económico (OCDE) y los mercados del petróleo crudo Brent y West Texas Intermediate (WTI). Para esto se proponen los modelos autorregresivos de intensidad condicional puntos sobre el umbral (ACI-POT), los cuales son capaces de capturar la intensidad de ocurrencia y comovimiento durante períodos dinámicos de crisis, y detectar factores estilizados típicamente presentes en este tipo de series de tiempo. La gran ventaja de esta metodología es que además de considerar la distribución del tamaño de los eventos extremos, utiliza también como fuente de información la distribución temporal de los eventos extremos. Con esto, los modelos ACI-POT son capaces de capturar de mejor forma el comportamiento de los clusters, y por lo tanto, distribuir las violaciones del valor en riesgo (VaR) a través del tiempo. Los resultados muestran una dependencia significativa para la interdependencia negativa de la mayoría de los mercados de la OCDE, destacándose los países de EE.UU, Japón y Francia que presentan alta dependencia al analizar sus pérdidas con los retornos positivos de ambos mercados del petróleo. Mientras que en el análisis de interdependencia positiva no se observa alguna tendencia en el conjunto de países de la OCDE, con excepción de Corea del Sur. Palabras Claves: Teoría de valores extremos, Mercados financieros, Mercados energéticos, Valor en Riesgo, Comovimientos./ABSTRACT: In this research, we analyze the degree of comovement that exists between extreme events across the stock markets of the Organisation for Economic Co-operation and Development (OECD) member nations and the Brent and West Texas Intermediate (WTI) crude oil markets. For this analysis, the autoregressive conditional intensity point over threshold (ACI-POT) models are proposed which are able to dynamically capture the intensity of occurrence and comovement during periods of crisis. These models also capture the stylized factors that are typically present in these time series. The great advantage of this methodology is that, apart from using the size distribution of extreme events, it also uses the occurrence times of extreme events as a source of information. With this information, ACI-POT models are better able to capture the stylized facts of extreme events in financial markets such as clustering behavior and cross-excitement than other models are. The results show a significant, negative interdependence between most OECD markets, especially those of the USA, Japan and France, which display high dependency when parsing losses to positive returns of both oil markets. However, positive interdependence is not observed between any of the OECD countries except for South Korea.Keywords: Extreme Value Theory, Financial Markets, Energy Markets, Value at Risk, Comovements

Las habilidades blandas y su orientación hacia la gestión de calidad en el nuevo escenario laboral de la empresa agrícola Puemape S.A.C - año 2020

La presente investigación tiene como objetivo: Determinar cómo las habilidades blandas se orientan en la gestión calidad en el nuevo escenario laboral de la empresa agrícola Puemape S.A.C. año 2020. El tipo de estudio es el no experimental, el diseño de estudio es aplicada - correlacional. La población de estudio estuvo conformada por los 21 colaboradores de la empresa agrícola Puemape SAC, para definir la muestra se usó los mismos datos de la población. Para la recolección de datos de las variables en estudio se usó como técnica la encuesta y cuestionario, los cuales se procesaron a través del software estadístico SPSS V.25. El resultado de la investigación mostro que el valor de la prueba de Chi cuadrado es de V=21.850 con un grado de libertad de “df=9”; Este número es mayor al de la tabla de valores de chi – cuadrado x2 > 16,9190. Por ende, se acepta que la hipótesis planteada es afirmativa, con un nivel significativo regular, por lo que se corrobora que las habilidades blandas inciden positivamente en su orientación a la gestión de calidad en el nuevo escenario laboral de la empresa agrícola Puemape S.A.C. Por lo tanto, se concluyó que las habilidades blandas se orientan positivamente en la gestión de la calidad en el nuevo escenario laboral de la empresa agrícola Puemape SAC, año 2020.The present research aims to determine how soft skills are oriented in quality management in the new labor scenario of the agricultural company Puemape S.A.C. year 2020. The type of study is non-experimental, the study design is applied - correlational. The study population was made up of the 21 collaborators of the agricultural company Puemape SAC, to define the sample the same population data was used. For the data collection of the variables under study, the survey and questionnaire were used as a technique, which was processed through the statistical software SPSS V.25. The result of the investigation showed that the value of the Chi-square test is V = 21,850 with a degree of freedom of “df = 9”; This number is greater than the one in the table of chi-square values x2> 16.9190. Therefore, it is accepted that the hypothesis proposed is affirmative, with a regular significant level, which is why it is corroborated that soft skills positively affect their orientation to quality management in the new labor scenario of the agricultural company Puemape S.A.C. Therefore, it was concluded that soft skills are positively oriented in quality management in the new labor scenario of the agricultural company Puemape SAC, the year 2020.Tesi

Reassessing statistical downscaling techniques for their robust application under climate change conditions

The performance of statistical downscaling (SD) techniques is critically reassessed with respect to their robust applicability in climate change studies. To this end, in addition to standard accuracy measures and distributional similarity scores, the authors estimate the robustness of the methods under warming climate conditions working with anomalous warm historical periods. This validation framework is applied to intercompare the performances of 12 different SD methods (from the analog, weather typing, and regression families) for downscaling minimum and maximum temperatures in Spain. First, a calibration of these methods is performed in terms of both geographical domains and predictor sets; the results are highly dependent on the latter, with optimum predictor sets including near-surface temperature data (in particular 2-m temperature), which appropriately discriminate cold episodes related to temperature inversion in the lower troposphere. Although regression methods perform best in terms of correlation, analog and weather generator approaches are more appropriate for reproducing the observed distributions, especially in case of wintertime minimum temperature. However, the latter two families significantly underestimate the temperature anomalies of the warm periods considered in this work. This underestimation is found to be critical when considering the warming signal in the late twenty-first century as given by a global climate model [the ECHAM5-Max Planck Institute (MPI) model]. In this case, the different downscaling methods provide warming values with differences in the range of 1°C, in agreement with the robustness significance values. Therefore, the proposed test is a promising technique for detecting lack of robustness in statistical downscaling methods applied in climate change studies.Thiswork has been funded by the Spanish I1D1i 2008-11 Program: A strategic action for energy and climate change (ESTCENA, code 200800050084078) and the project CGL2010-21869 (EXTREMBLES). S.B. was supported by a JAE PREDOC grant (CSIC, Spain). The authors would like to especially thank the three anonymous reviewers who helped to considerably improve this manuscript

Reassessing model uncertainty for regional projections of precipitation with an ensemble of statistical downscaling methods

This is the second in a pair of papers in which the performance of Statistical Downscaling Methods (SDMs) is critically re-assessed with respect to their robust applicability in climate change studies. Whereas Part I focused on temperatures (Gutierrez et al., 2013), the present manuscript deals with precipitation and considers an ensemble of twelve SDMs from the analog, weather typing, and regression (GLM) families. In the first part, we assess the performance of the methods with perfect (reanalysis) predictors, screening different geographical domains and predictor sets. To this aim, standard accuracy and distributional similarity scores, and a test for extrapolation capability based on dry observed historical periods are considered. As in Part I, the results are highly dependent on the predictor sets, with optimum configurations including information of middle tropospheric humidity (in particular Q850). As a result of this analysis, deficient SDMs are discarded in order to properly assess the spread (uncertainty) of future climate projections, avoiding the noise introduced by unsuitable models. In the second part, the resulting ensemble of SDMs is applied to four Global Circulation Models (GCMs) from the ENSEMBLES (CMIP3) project to obtain historical (1961-2000, 20C3M scenario) and future (2001-2100, A1B) regional projections. The obtained results are compared with those produced by an ensemble of Regional Climate Models (RCMs) driven by almost the same GCMs in the ENSEMBLES project. In general, the mean signal is similar with both methodologies (with the exception of Summer, where the RCMs project drier conditions) but the spread is larger for the SDM results. Finally, the contribution of the GCM and SDM-derived components to the total spread is assessed using a simple analysis of variance previously applied to the ENSEMBLES RCM ensemble. Results show that the main contributor to the spread is the choice of the GCM, except for the autumn results in the Atlantic sub-region of Spain and the Autumn and Summer results in the Mediterranean sub-region, where the choice of the SDM dominates the uncertainty during the second half of the 21st century due mainly to the different projections obtained from different families of SDM techniques. The most noticeable difference with the RCMs is the magnitude of the interaction terms, which is larger in all cases in the present study.This work has been funded by the strategic action for energy and climate change by the Spanish R&D 2008–2011 program ‘‘Programa coordinado para la generación de escenarios regionalizados de cambio climático: Regionalización Estadística (esTcena),’’ code 200800050084078, and the project CGL2015-66583-R (MINECO/FEDER). The RCM simulations used in this study were obtained from the European Union–funded FP6 Integrated Project ENSEMBLES (Contract 505539)

Evolución de las cabañas ganaderas en Aragón (1995-2019) y su relación con factores geográficos y ambientales

En el presente Trabajo Fin de Grado se analiza la evolución de las cabañas ganaderas en la Comunidad Autónoma de Aragón en los últimos 25 años, así como su posible relación con factores ambientales y geográficos, utilizando como unidad de estudio la comarca y el municipio.Las cabañas seleccionadas como fuente de información corresponden tanto a la bovina, de características tanto extensivas como intensivas, como a las ganaderías ovina y caprina, con fuerte carácter extensivo en el territorio aragonés. Entre las variables estudiadas sobre las que se busca analizar la posible relación con la densidad de las cabañas ganaderas se encuentran la altitud, la superficie, temperatura y precipitación, superficie agrícola utilizada, y, por último, factores demográficos poblacionales de cada municipio.Los resultados obtenidos muestran que la cabaña bovina ha pasado en dos décadas (1995-99 al 2015-19) de 291.859 a 429.988 cabezas lo que significa un incremento del 47%. Por comarcas, siete comarcas han visto doblado su cabaña bovina (incremento mayor del 100%) y diez comarcas han aumentado su cabaña en al menos un 50%. Siete de las 33 comarcas aragonesas han mostrado una diminución de la cabaña bovina de más del 10%. La cabaña ovina ha pasado en dos décadas (1995-99 al 2015-19) de 2.740.588 a 2.031.376 lo que significa una disminución del 26%. Por comarcas, 24 de las 33 comarcas han mostrado una disminución de más del 10%, con cuatro comarcas mostrando disminuciones de más del 50% (Bajo Martín, Campo de Cariñena, La Litera y Campo de Belchite). Cuatro comarcas han mostrado aumento en la cabaña ovina de más del 10%, de las cuales tres son comarcas pirenaicas (Sobrarbe, Alto Gállego y Jacetania). Respecto a la cabaña caprina, al igual que sucede con la ovina, ésta ha experimentado un decrecimiento en torno a un 35% pasando de 67.888 cabezas a 43.986. Únicamente 5 comarcas (Somontano de Barbastro, La Ribagorza, Campo de Daroca, Valdejalón y Sierra de Albarracín) experimentan una variación positiva en la cabaña caprina. Por contra, de las 28 comarcas restantes que presentan una disminución del ganado caprino, 8 lo hacen en más de un 50%. Los resultados muestran una relación entre el tamaño de las cabañas ganaderas estudiadas y municipios situados a menor altitud, con condiciones climáticas de temperatura y precipitación más favorables, mayor superficie agrícola útil y una mayor densidad poblacional. Respecto de la evolución temporal, las variables demográficas fueron las de mayor capacidad explicativa, siendo aquellos municipios que menor pérdida han experimentado o que han visto aumentado su población, los que presentan un menor descenso de sus cabañas ganaderas.<br /

Evaluation of cytotoxicity, antimicrobial activity and physicochemical properties of a calcium aluminate-based endodontic material

A calcium aluminate-based endodontic material, EndoBinder, has been developed in order to reduce MTA negative characteristics, preserving its biological properties and clinical applications. Objectives: The aim of this study was to evaluate the cytotoxicity, antimicrobial activity, pH, solubility and water sorption of EndoBinder and to compare them with those of white MTA (WMTA). Material and Methods: Cytotoxicity was assessed through a multiparametric analysis employing 3T3 cells. Antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus. (ATCC 25923) and Candida albicans (ATCC 10556) was determined by the agar diffusion method. pH was measured at periods of 3, 24, 72 and 168 hours. Solubility and water sorption evaluation were performed following ISO requirements. Data were statistically analyzed by ANOVA and Tukey's test with a significance level of 5%. Results: EndoBinder and WMTA were non-cytotoxic in all tested periods and with the different cell viability parameters. There was no statistical differences between both materials (P>.05). All tested materials were inhibitory by direct contact against all microbial strains tested. EndoBinder and WMTA presented alkaline pH in all tested times with higher values of pH for WMTA (P.05). Conclusion: Under these experimental conditions, we concluded that the calcium aluminate-based endodontic material EndoBinder demonstrated suitable biological and physicochemical properties, so it can be suggested as a material of choice in root resorption, perforations and root-end filling221616

Evaluation of cytotoxicity, antimicrobial activity and physicochemical properties of a calcium aluminate-based endodontic material

A calcium aluminate-based endodontic material, EndoBinder, has been developed in order to reduce MTA negative characteristics, preserving its biological properties and clinical applications. Objectives: The aim of this study was to evaluate the cytotoxicity, antimicrobial activity, pH, solubility and water sorption of EndoBinder and to compare them with those of white MTA (WMTA). Material and Methods: Cytotoxicity was assessed through a multiparametric analysis employing 3T3 cells. Antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus. (ATCC 25923) and Candida albicans (ATCC 10556) was determined by the agar diffusion method. pH was measured at periods of 3, 24, 72 and 168 hours. Solubility and water sorption evaluation were performed following ISO requirements. Data were statistically analyzed by ANOVA and Tukey`s test with a significance level of 5%. Results: EndoBinder and WMTA were non-cytotoxic in all tested periods and with the different cell viability parameters. There was no statistical differences between both materials (P>;.05). All tested materials were inhibitory by direct contact against all microbial strains tested. EndoBinder and WMTA presented alkaline pH in all tested times with higher values of pH for WMTA (

The Origins of [CII] Emission in Local Star-forming Galaxies

The [CII] 158um fine-structure line is the brightest emission line observed in local star-forming galaxies. As a major coolant of the gas-phase interstellar medium, [CII] balances the heating, including that due to far-ultraviolet photons, which heat the gas via the photoelectric effect. However, the origin of [CII] emission remains unclear, because C+ can be found in multiple phases of the interstellar medium. Here we measure the fractions of [CII] emission originating in the ionized and neutral gas phases of a sample of nearby galaxies. We use the [NII] 205um fine-structure line to trace the ionized medium, thereby eliminating the strong density dependence that exists in the ratio of [CII]/[NII] 122um. Using the FIR [CII] and [NII] emission detected by the KINGFISH and Beyond the Peak Herschel programs, we show that 60-80% of [CII] emission originates from neutral gas. We find that the fraction of [CII] originating in the neutral medium has a weak dependence on dust temperature and the surface density of star formation, and a stronger dependence on the gas-phase metallicity. In metal-rich environments, the relatively cooler ionized gas makes substantially larger contributions to total [CII] emission than at low abundance, contrary to prior expectations. Approximate calibrations of this metallicity trend are provided.Comment: 8 pages, accepted for publication in Ap

Análise de Canais do YouTube como Objetos de Aprendizagem de Suporte ao Estudo de Cálculo I em Cursos da Área de Ciências Exatas

Video lessons are no longer just an adjunct to learning, they have been increasingly added to the study routine of students at different educational levels. The use of YouTube video lessons as a complementary tool is increasingly growing, regardless of the area of study. However, there is little literature regarding the effectiveness of the teaching models used in these videos. Considering the difficulties of students in learning mathematics, the objective of this work is to carry out a survey and analysis of the main Mathematics channels on YouTube watched by students, as complementarity to studies, from courses in the STEAM area of the Virtual University of the State of São Paulo. To achieve such goal the twelve principles of multimedia learning formulated by Richard Mayer were applied: Coherence, Signaling, Redundancy, Spatial Contiguity, Temporal Contiguity, Segmentation, Pre-training, Modality, Multimedia, Personalization, Voice, and Image. Information was collected from the channels accessed by students using forms and the five channels with the highest number of views on the YouTube platform were selected. After the analysis, it was found that a most of the principles are present in teaching strategies of the teachers who manage the channels, highlighting redundancy, temporal contiguity, modality, personalization, voice and image. Still, details related to visual issues and accessibility when playing videos can be improved.   Keywords:  Learning objects. Information and communication technologies. University. teaching, YouTube.Las videoaulas ya no son sólo un complemento del aprendizaje y cada vez se han incorporado más a la rutina de estudio de los estudiantes de los diferentes niveles educativos. Ante este interés cada vez mayor en este tipo de midia, surge la preocupación respecto a la efectividad de los modelos didácticos utilizados en estos materiales. El objetivo de este trabajo fue analizar los canales de Matemáticas de YouTube señalados por estudiantes de carreras de Ciencias Exactas de la Universidad Virtual del Estado de São Paulo que utilizan este recurso como complemento a sus estudios. Para ello utilizamos los 12 principios del aprendizaje multimedia formulados por Richard Mayer: Coherencia, Señalización, Redundancia, Contigüidad Espacial, Contigüidad Temporal, Segmentación, Pre-entrenamiento, Modalidad, Multimedia, Personalización, Voz e Imagen. Se recopiló información de los canales a los que accedieron los estudiantes mediante un formulario y se seleccionaron los cinco canales que contaban con mayor número de visualizaciones en la plataforma YouTube. Entre los canales analizados, se encontró que buena parte de los principios están presentes en la didáctica aplicada por los profesores, siendo los que más aparecieron: redundancia, contigüidad temporal, modalidad, personalización, voz e imagen, pero se pueden utilizar algunos ajustes para aumentar aún más la calidad de las clases.A videoaula deixou de ser apenas uma coadjuvante da aprendizagem, e tem sido cada vez mais agregada à rotina de estudos de alunos em diferentes níveis educacionais. Com o interesse cada vez mais crescente, surge a inquietação em relação à eficácia dos modelos de ensino utilizados nestes materiais. O objetivo deste trabalho foi realizar a análise de canais de Matemática do YouTube apontados por alunos dos cursos da área de Ciências Exatas da Universidade Virtual do Estado de São Paulo que fazem uso deste recurso como complementação aos estudos. Para isso, utilizou-se os 12 princípios da aprendizagem multimídia formulada por Richard Mayer: Coerência, A videoaula deixou de ser apenas uma coadjuvante da aprendizagem, e tem sido cada vez mais agregada à rotina de estudos de alunos em diferentes níveis educacionais. O uso de videoaulas do YouTube como ferramenta complementar é cada vez mais crescente, independente da área de estudo. Entretanto, é escassa a literatura em relação à eficácia dos modelos de ensino utilizados nestas videoaulas. Tendo em vista a dificuldade por parte dos alunos na aprendizagem em matemática, o objetivo deste trabalho foi realizar o levantamento e análise dos principais canais de Matemática do YouTube assistidos por alunos dos cursos da área de Ciências Exatas da Universidade Virtual do Estado de São Paulo como complementaridade aos estudos. Para isso, aplicaram-se os doze princípios da aprendizagem multimídia formulada por Richard Mayer: Coerência, Sinalização, Redundância, Contiguidade espacial, Contiguidade temporal, Segmentação, Pré-treinamento, Modalidade, Multimídia, Personalização, Voz e Imagem. Foram coletadas informações dos canais acessados pelos estudantes por meio de um formulário e selecionados os cinco canais com maior número de visualizações na plataforma YouTube. Após a análise constatou-se que boa parte dos princípios está presente na didática dos professores que dirigem os canais, sendo os que mais apareceram: redundância, contiguidade temporal, modalidade, personalização, voz e imagem. Ainda assim, detalhes relacionados à questões visuais e de acessibilidade na reprodução dos vídeos podem ser melhorados.   Palavras-chave: Objetos de aprendizagem. Tecnologias da informação e comunicação. Ensino superior.  YouTube