A reinterpretation of Volcano Ranch lateral distribution measurements to infer the mass composition of cosmic rays

In the course of its operation, the Volcano Ranch array collected data on the lateral distribution of showers produced by cosmic rays at energies above 1017 eV. From these data very precise measurements of the steepness of the lateral distribution function, characterized by the η parameter, were made. The current availability of sophisticated hadronic interaction models has prompted a reinterpretation of the measurements. We use the interaction models QGSJET and SIBYLL in the AIRES Monte Carlo code to generate showers together with GEANT4 to simulate the response of the detectors to ground particles. As part of an effort to estimate the primary mass composition of cosmic rays at this energy range, we present the results of our preliminary analysis of the distribution of η.Facultad de Ciencias Exacta

Electron Transfer Initiated Reactions Photoinduced by Pterins

Interest in the photochemistry and photophysics of pterins has increased since the participation of this family of compounds in different photobiological processes has been suggested or demonstrated in recent decades. Pterins participate in relevant biological processes, such as metabolic redox reactions, and can photoinduce the oxidation of biomolecules through both electron transfer mechanisms (Type I) and singlet oxygen production (Type II). This article describes recent findings on electron transfer-initiated reactions photoinduced by the triplet excited state of pterins and connects them in the context of photosensitized processes of biological relevance.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

High energy physics in the atmosphere: phenomenology of cosmic ray air showers

The properties of cosmic rays with energies above 106 GeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review we summarize the phenomenology of these giant air showers. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, and discuss the prospects for insights into forward physics at the LHC. We also describe the main electromagnetic processes that govern the longitudinal shower evolution, as well as the lateral spread of particles. Armed with these two principal shower ingredients and motivation from the underlying physics, we provide an overview of some of the different methods proposed to distinguish primary species. The properties of neutrino interactions and the potential of forthcoming experiments to isolate deeply penetrating showers from baryonic cascades are also discussed. We finally venture into a terra incognita endowed with TeV-scale gravity and explore anomalous neutrino-induced showers.Facultad de Ciencias Exacta

La dramaturgia del actor/actriz o la creación de sentido/discurso en la interacción con el espacio que lo circunda y con el mundo objetual

El propósito de este texto es exponer el recorrido metodológico del Proyecto de Investigación sobre la producción final de las carreras Tecnicatura en Actuación, Profesorado de Teatro y Tecnicatura en Escenografía en el espectáculo producido: Un cerdo Una jaula con antibióticos/ entre lo virtual y lo escénico. Los objetivos del proyecto son: - Abordar un material dramático que no centre su ejecución en un texto de autor clásico. - Generar una propuesta en relación al proceso de investigación y búsqueda personal de los y las estudiantes, valorando el aporte estético individual y personal, donde cada estudiante es su propio objeto de investigación. - Concertar la producción de un espectáculo teatral a partir de la investigación en el trabajo actoral como lenguaje vertebrador de la puesta en escena.Dramatiza La Plat

Evaluación de habilidades verbales, cuantitativas, de inteligencia fluida y generales de razonamiento en población estudiantil indígena de las zonas sur y atlántica de Costa Rica

Proyecto de Investigación (Código VIE 540117016070) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE); Vicerrectoría de Vida Estudiantil y Servicios Académicos. Departamento de Orientación y Psicología; Vicerrectoría de Docencia. Escuela de Matemática, 2013Un grupo de investigadores(as) de la Universidad de Costa Rica (UCR) y del Instituto Tecnológico de Costa Rica (ITCR) se propusieron evaluar las habilidades verbales, cuantitativas, de inteligencia fluida y generales de razonamiento asociadas al perfil de ingreso para el acceso a la educación superior en estudiantes de colegios indígenas. Para tal propósito se aplicaron las pruebas de admisión de ambas universidades y tres específicas de la UCR a estudiantes que cursaron en el 2011 y 2012 el último año de la educación secundaria de un colegio rural, urbano y de los pueblos indígenas Bribri, Brunca, Cabecar y Ngöbe. Es un estudio de tipo exploratorio, descriptivo y correlacional, basado en técnicas de recolección y análisis de datos cuantitativos y cualitativos. En general, los promedios obtenidos por los estudiantes autoclasificados como indígenas fueron relativamente más bajos en las distintas pruebas y, particularmente, aquellos que provenían de colegios indígenas y tenían extra edad estaban en desventaja con respecto a los dos grupos de control (urbano y rural). También se encontraron evidencias de validez de criterio entre la prueba de razonamiento de figuras y ambas pruebas de admisión, así como entre la prueba de Expresión Escrita y la de admisión de la UCR. A partir de hallazgos de este proyecto se logró generar algunas recomendaciones para establecer un futuro programa alternativo de admisión dirigido a estudiantes indígenas, que contribuyan a incrementar el acceso y éxito de estos jóvenes en la educación superior estatal de Costa Rica.Vicerrectoría de Investigación y Extensión del Instituto Tecnológico de Costa Rica y Universidad de Costa Rica

A reinterpretation of Volcano Ranch lateral distribution measurements to infer the mass composition of cosmic rays

In the course of its operation, the Volcano Ranch array collected data on the lateral distribution of showers produced by cosmic rays at energies above 1017 eV. From these data very precise measurements of the steepness of the lateral distribution function, characterized by the η parameter, were made. The current availability of sophisticated hadronic interaction models has prompted a reinterpretation of the measurements. We use the interaction models QGSJET and SIBYLL in the AIRES Monte Carlo code to generate showers together with GEANT4 to simulate the response of the detectors to ground particles. As part of an effort to estimate the primary mass composition of cosmic rays at this energy range, we present the results of our preliminary analysis of the distribution of η.Facultad de Ciencias Exacta

Haplotype profile comparisons cetween Spodoptera frugiperda (Lepidoptera: Noctuidae) populations from Mexico with those from Puerto Rico, South America, and the United States and their implications to migratory behavior

Fall armyworm [Spodoptera frugiperda (J. E. Smith)] is a major economic pest throughout the Western Hemisphere of maize, cotton, sorghum, and a variety of agricultural grasses and vegetable crops. Previous studies demonstrated extensive annual migrations occurring as far north as Canada from overwintering locations in southern Florida and Texas. In contrast, migratory behavior in the rest of the hemisphere is largely uncharacterized. Understanding the migration patterns of fall armyworm will facilitate efforts to predict the spread of pesticide resistance traits that repeatedly arise in this species and assess the consequences of changing climatic trends on the infestation range. Four independent fall armyworm colonies derived from widely separated populations in Mexico and two field collections were examined for their mitochondrial cytochrome oxidase I (COI) gene haplotypes and compared with other locations. The Mexico populations were most similar in their haplotype profile to those from Texas and South America, but also displayed some distinctive features. The data extend the haplotype distribution map in the Western Hemisphere and confirm that the previously observed regional differences in haplotype frequencies are stable over time. The Mexico collections were associated with haplotypes rarely found elsewhere, suggesting limited migratory interactions with foreign populations, including those in neighboring Texas.Fil: Nagoshi, Rodney N.. United States Department Of Agriculture. Agricultural Research Service; ArgentinaFil: Rosas Garcia, Ninfa M.. Instituto Politécnico Nacional; MéxicoFil: Meagher, Robert L.. United States Department Of Agriculture. Agricultural Research Service; ArgentinaFil: Fleischer, Shelby J.. State University Of Pennsylvania; Estados UnidosFil: Westbrook, John K.. United States Department Of Agriculture. Agricultural Research Service; ArgentinaFil: Sappington, Thomas W.. United States Department Of Agriculture. Agricultural Research Service; ArgentinaFil: Hay Roe, Mirian. United States Department Of Agriculture. Agricultural Research Service; ArgentinaFil: Thomas, Jean M. G.. United States Department Of Agriculture. Agricultural Research Service; ArgentinaFil: Murúa, María Gabriela. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Electron Transfer Initiated Reactions Photoinduced by Pterins

Interest in the photochemistry and photophysics of pterins has increased since the participation of this family of compounds in different photobiological processes has been suggested or demonstrated in recent decades. Pterins participate in relevant biological processes, such as metabolic redox reactions, and can photoinduce the oxidation of biomolecules through both electron transfer mechanisms (Type I) and singlet oxygen production (Type II). This article describes recent findings on electron transfer-initiated reactions photoinduced by the triplet excited state of pterins and connects them in the context of photosensitized processes of biological relevance.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

High energy physics in the atmosphere: phenomenology of cosmic ray air showers

The properties of cosmic rays with energies above 106 GeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review we summarize the phenomenology of these giant air showers. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, and discuss the prospects for insights into forward physics at the LHC. We also describe the main electromagnetic processes that govern the longitudinal shower evolution, as well as the lateral spread of particles. Armed with these two principal shower ingredients and motivation from the underlying physics, we provide an overview of some of the different methods proposed to distinguish primary species. The properties of neutrino interactions and the potential of forthcoming experiments to isolate deeply penetrating showers from baryonic cascades are also discussed. We finally venture into a terra incognita endowed with TeV-scale gravity and explore anomalous neutrino-induced showers.Facultad de Ciencias Exacta

Photodynamic Therapy in HeLa Cells Incubated with Riboflavin and Pectin-coated Silver Nanoparticles

Riboflavin (Rf) is an endogenous photosensitizer, which can participate in Type I and Type II processes. We have recently shown that the yield of the triplet excited states of Rf is enhanced in the presence of pectin-coated silver nanoparticles (Pec@AgNP) due to formation of a complex between Rf and Pec@AgNP (Rf-Pec@AgNP). Consequently, under aerobic conditions, the amounts of singlet molecular oxygen and superoxide radical anion generated are also larger in the presence of the nanoparticles. This result made us suspect that the nanoparticles could have a beneficial effect in Rf-based PDT. To prove this hypothesis, we here compared the photodamage in HeLa cells incubated with Rf in the presence and in the absence of Pec@AgNP applying several optical assays. We used fluorescence imaging of irradiated HeLa cells incubated with Annexin V and propidium iodide to evaluate the occurrence of apoptosis/necrosis, the reduction of the tetrazolium dye MTT to formazan and neutral red uptake to prove cell viability, as well as synchrotron infrared microscopy of single cells to evaluate possible structural changes of DNA and nuclear proteins. The enhanced photodamage observed in the presence of Pec@AgNP seems to indicate that Rf enters into the cells complexed with the nanoparticles.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasInstituto Multidisciplinario de Biología CelularConsejo Nacional de Investigaciones Científicas y Técnica