Lasso Estimation of an Interval-Valued Multiple Regression Model

A multiple interval-valued linear regression model considering all the cross-relationships between the mids and spreads of the intervals has been introduced recently. A least-squares estimation of the regression parameters has been carried out by transforming a quadratic optimization problem with inequality constraints into a linear complementary problem and using Lemke's algorithm to solve it. Due to the irrelevance of certain cross-relationships, an alternative estimation process, the LASSO (Least Absolut Shrinkage and Selection Operator), is developed. A comparative study showing the differences between the proposed estimators is provided

A Practical Environment to Apply Model-Driven Web Engineering

The application of a model-driven paradigm in the development of Web Systems has yielded very good research results. Several research groups are defining metamodels, transformations, and tools which offer a suitable environment, known as model-driven Web engineering (MDWE). However, there are very few practical experiences in real Web system developments using real development teams. This chapter presents a practical environment of MDWE based on the use of NDT (navigational development techniques) and Java Web systems, and it provides a practical evaluation of its application within a real project: specialized Diraya.Ministerio de Educación y Ciencia TIN2007-67843-C06-03Ministerio de Educación y Ciencia TIN2007-30391-

Is having difficulty meeting the recommended physical activity guidelines associated with cognitive difficulties in US adults?

This abstract summarizes and gives a brief overview of our analytical research study on the associations of meeting physical activity guidelines and cognitive difficulties such as difficulty remembering/concentrating

Evaluación de características de las personas mayores y su relación con la calidad percibida de la gestión deportiva

Sports management seeks at all times a greater loyalty and control of users who evaluate their service provided through questionnaires of perceived quality. The objective of the present investigation was to evaluate the perceived quality of three hundred and three people through the Questionnaire for the Evaluation of Perceived Quality in Sports Services (CECASDEP), validated in a Spanish sample. The results indicated that the most valued dimension is that of the teacher-monitor, although the rest of the dimensions (sports facilities, activity space, changing rooms and activity programs) also obtained a high score with respect to the average values, which leads to relate the satisfaction with the perceived quality, and therefore, the loyalty of users also increases, thanks in some way to the motivation that produces the service they have provided. It is concluded that the assessment of the sports technician is the most positive, obtaining a key role for all sports institutions.La gestión deportiva busca en todo momento una mayor fidelización y control de los usuarios que evalúan su servicio prestado a través de cuestionarios de calidad percibida. El objetivo de la presente investigación fue evaluar la calidad percibida en trescientas tres personas a través del Cuestionario de Evaluación de la Calidad Percibida en Servicios Deportivos (CECASDEP), validado en muestra española. Los resultados indicaron que la dimensión más valorada es la del profesor-monitor, aunque el resto de dimensiones (instalaciones deportivas, espacio de actividad, vestuarios y programas de actividades) también obtuvieron una puntuación elevada con respecto a los valores medios, lo que conlleva a relacionar la satisfacción con la calidad percibida, y por ende, la fidelización de los usuarios también aumenta, gracias en cierto modo a la motivación que le produce el servicio que le han prestado. Se concluye que la valoración del técnico deportivo es la más positiva, obteniendo un papel clave para todas las instituciones deportivas

Aislamiento e identificación molecular de microrganismos asociados a la caña de azúcar (Saccharum officinarum) variedad CP 722086

The cultivation of sugar cane contributes to the Nicaraguan economy generating 6.9% of the national GDP in 2016. Currently, it is at risk the growth of the sugar industry and its transformation into a bio factory, both by poor agricultural practices (excessive use of agrochemicals and soil degradation) as by the effects of climate change, ranging from droughts to emerging diseases and pests.One of the most promising alternatives for dealing with the problem is the knowledge of the native microorganisms (pathogens and beneficial) associated with the main crops and be able to make sound management decisions. In this work, we isolate these microorganisms, we identified them at the DNA level and obtained information of its role and relationship with the culture, constituting a biological database that will be used for the development of biological products and improved control strategies for emerging pathogens. This pioneering research developed in Nicaragua, focused on the microbiotic associated to the cultivation of sugarcane and contributes to the understanding of the plant-soil system relationship. These results are inputs to agricultural innovation, mitigation of the effects of climate change and environmental sustainability.El cultivo de la caña de azúcar contribuye a la economía nicaragüense generando el 6.9% del PIB nacional en 2016. Actualmente, está en riesgo el crecimiento de la industria azucarera y su transformación en una biofabrica, tanto por las malas prácticas agrícolas (uso excesivo de agroquímicos y degradación del suelo) como por los efectos del cambio climático, que van desde sequías hasta enfermedades y plagas emergentes. Una de las alternativas más prometedoras para enfrentar la problemática, es el conocimiento de los microorganismos nativos asociados a los principales cultivos (patógenos y benéficos) y poder tomar decisiones de manejo acertadas. En este trabajo, aislamos éstos microorganismos, los identificamos a nivel de ADN y obtuvimos información de su función y relación con el cultivo, constituyendo una base de datos biológica que en adelante será utilizada para el desarrollo de productos biológicos y las mejores estrategias de control para los patógenos emergentes. Esta pionera investigación desarrollada en Nicaragua, enfocada en la microbiota asociada al cultivo de la caña de azúcar, contribuye a la comprensión de la relación plantasuelo. Y los resultados aportan a la innovación agrícola, la mitigación de los efectos del cambio climático y la sostenibilidad ambiental

Aislamiento e identificación molecular de microrganismos asociados a la caña de azúcar (Saccharum officinarum) variedad CP 722086

The cultivation of sugar cane contributes to the Nicaraguan economy generating 6.9% of the national GDP in 2016. Currently, it is at risk the growth of the sugar industry and its transformation into a bio factory, both by poor agricultural practices (excessive use of agrochemicals and soil degradation) as by the effects of climate change, ranging from droughts to emerging diseases and pests.One of the most promising alternatives for dealing with the problem is the knowledge of the native microorganisms (pathogens and beneficial) associated with the main crops and be able to make sound management decisions. In this work, we isolate these microorganisms, we identified them at the DNA level and obtained information of its role and relationship with the culture, constituting a biological database that will be used for the development of biological products and improved control strategies for emerging pathogens. This pioneering research developed in Nicaragua, focused on the microbiotic associated to the cultivation of sugarcane and contributes to the understanding of the plant-soil system relationship. These results are inputs to agricultural innovation, mitigation of the effects of climate change and environmental sustainability.El cultivo de la caña de azúcar contribuye a la economía nicaragüense generando el 6.9% del PIB nacional en 2016. Actualmente, está en riesgo el crecimiento de la industria azucarera y su transformación en una biofabrica, tanto por las malas prácticas agrícolas (uso excesivo de agroquímicos y degradación del suelo) como por los efectos del cambio climático, que van desde sequías hasta enfermedades y plagas emergentes. Una de las alternativas más prometedoras para enfrentar la problemática, es el conocimiento de los microorganismos nativos asociados a los principales cultivos (patógenos y benéficos) y poder tomar decisiones de manejo acertadas. En este trabajo, aislamos éstos microorganismos, los identificamos a nivel de ADN y obtuvimos información de su función y relación con el cultivo, constituyendo una base de datos biológica que en adelante será utilizada para el desarrollo de productos biológicos y las mejores estrategias de control para los patógenos emergentes. Esta pionera investigación desarrollada en Nicaragua, enfocada en la microbiota asociada al cultivo de la caña de azúcar, contribuye a la comprensión de la relación plantasuelo. Y los resultados aportan a la innovación agrícola, la mitigación de los efectos del cambio climático y la sostenibilidad ambiental

Análisis del funcionamiento de la configuración del reactor anaerobio de flujo ascendente – filtro percolador para el tratamiento a escala real de aguas residuales domésticas

Además de la existencia de plantas de tratamiento de aguas residuales (PTAR), es necesario asegurar su efectividad y sostenibilidad en el tiempo a través de una adecuada selección de tecnologías, buen diseño y construcción y buenas prácticas de operación y mantenimiento. La configuración Reactor UASB seguida de Filtro Percolador, ha demostrado la obtención de un efluente acorde con los requerimientos de la legislación ambiental; el Departamento del Valle del Cauca-Colombia tiene 19PTAR y cinco de ellas presentan esta configuración. Aunque elanálisis realizado a estas PTAR, muestra debilidades asociadas a selección inadecuada de criterios de diseño y deficiencias de operación y mantenimiento, se encontró un desempeño adecuado en términos de eficiencias de remoción de DQO, DBO5 y SST (alrededor de 80%). Dadas las bondades de esta configuración para el tratamiento de aguas residuales domésticas, es recomendable establecer criterios de diseño, operación y mantenimiento apropiados, lo que resultará en una mayor capacidad y eficiencia del tratamiento

Recent experimental results in sub- and near-barrier heavy ion fusion reactions

Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus will be mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations over-predict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars.Comment: 40 pages, 63 figures, review paper accepted for EPJ

Potential-density pairs for axisymmetric galaxies: the influence of scalar fields

We present a formulation for potential-density pairs to describe axisymmetric galaxies in the Newtonian limit of scalar-tensor theories of gravity. The scalar field is described by a modified Helmholtz equation with a source that is coupled to the standard Poisson equation of Newtonian gravity. The net gravitational force is given by two contributions: the standard Newtonian potential plus a term stemming from massive scalar fields. General solutions have been found for axisymmetric systems and the multipole expansion of the Yukawa potential is given. In particular, we have computed potential-density pairs of galactic disks for an exponential profile and their rotation curves.Comment: 8 pages, no figures, corrected version to the one that will appear in Gen. Relativ. Gravit., where a small typo in eq. (13) is presen

Biogeochemistry of surface sediments in an Antarctic nearshore area affected by recent glacier retreat: Collins Harbour, King George Island

Biochemical composition of sedimentary organic matter, grain size, major and trace elements were analysed at 10 sampling stations in Collins Harbour, Maxwell Bay, to evaluate sources of particulate material in the seafloor. Surface sediment samples were taken with a grab, during the ANTAR XXV expedition in January 2018, onboard the BAP Carrasco from the Peruvian Navy. Coarse sediment fractions decreased, while mud content increased towards the centre of the bay. Positive correlation between mud and the biopolymeric carbon (BPC) indicated depositional conditions and organic material accumulation in the deepest central area. Proteins (PRT) predominated over other biochemical classes contributing to labile organic carbon, followed by lipids (LIP) and carbohydrates (CHO). PRT positive correlation with Ba, Ca and Al indicated that labile organic carbon inputs derived from marine primary production. Whereas, PRT positive correlation with K and Ti suggested also the influence of terrestrial supply through Collins Glacier meltwater runoff. Mn/Ti, Mn/Al and Fe/Al ratios decreased towards the centre of the bay, while the Ba/Al ratio showed the opposite trend. This distributional pattern suggested the diminish of glacial and terrigenous sedimentation towards the deepest central area of the bay, with the increment of marine particulate material deposition and accumulation. Igeo values between 0 and 1 showed unpolluted conditions in Collins Harbour for Cr, Ni, Cu, Zn, As and Pb, which concentrations may reflect background values for this area. Natural inputs from weathering, glacial runoff and marine primary production are main sources of particulate material in Collins Harbour, with none detected anthropogenic contributions