Estructuras de fijación de pelmatozoas (equinodermos) en el Ordovícico Medio de la Zona Centroibérica española

Se describen diversas estructuras discoidales a subcónicas, cementadas a restos esqueléticos de braquiópodos, moluscos, trilobites y cistideos. que constituyen los primeros elementos de fijación de pelmatozoos a sustratos firmes encontrados en el Ordovícico Medio de la Zona Centroibérica del Macizo Hespérico. El material proviene de cinco localidades de edad comprendida entre el Oretaniense inferior y el Dobrotiviense superior, y ha sido asignado a los morfogéneros Podolithus y Lichenocrinus?, el primero de los cuales se conocía previamente en las calizas del Ashgill de la Rama Aragonesa de la Cordillera Ibérica. Los ejemplares de Podolithus encontrados en las Capas con Tristani pertenecen al menos a dos morfoespecies distintas, tratadas en nomenclatura abierta, que sc diferencian por sus caracteres morfológicos y los fragmentos pluricolumnales asociados. [ABSTRACT] Pelmatozoan holdfasts, in Ihe form of discoid to subeonical multiplated structures, have been observed attached to shelly fragments ol articulate brachiopods. molluscs, trilobites and cystoids from five localities of the Central Iberian Zone of the Hesperian Massif. The described material ranges from lower Oretanian to upper Dobrotivian in age, and represents the first evidence of hard substrate colonization by echinoderms in the Middle Ordovician of Spain. The identified taxa belong to the morphogenera Podolithus and ?Lichenocrinus, the former also recorded from Ashgill limestones in the eastern Iberian Cordillera. At least two morphospecies of Podolithus, which have been left in open nomenclature, are distinguished on the basis of their overall morphology and stem characteristies

Desarrollo de una herramienta de análisis de movimiento para brazo humano

Este artículo presenta una metodología de evaluación de la funcionalidad del movimiento del brazo humano. La metodología incluye la definición de un modelo físico del brazo, la adquisición del movimiento, análisis cinemáticos, cinéticos y de activación muscular. Estas herramientas pueden ser utilizadas en el diagnóstico de patologías del miembro superior, como apoyo para estudios ergonómicos y en el análisis de gestos deportivos

Characterization of viroplasm formation during the early stages of rotavirus infection

Abstract Background During rotavirus replication cycle, electron-dense cytoplasmic inclusions named viroplasms are formed, and two non-structural proteins, NSP2 and NSP5, have been shown to localize in these membrane-free structures. In these inclusions, replication of dsRNA and packaging of pre-virion particles occur. Despite the importance of viroplasms in the replication cycle of rotavirus, the information regarding their formation, and the possible sites of their nucleation during the early stages of infection is scarce. Here, we analyzed the formation of viroplasms after infection of MA104 cells with the rotavirus strain RRV, using different multiplicities of infection (MOI), and different times post-infection. The possibility that viroplasms formation is nucleated by the entering viral particles was investigated using fluorescently labeled purified rotavirus particles. Results The immunofluorescent detection of viroplasms, using antibodies specific to NSP2 showed that both the number and size of viroplasms increased during infection, and depend on the MOI used. Small-size viroplasms predominated independently of the MOI or time post-infection, although at MOI's of 2.5 and 10 the proportion of larger viroplasms increased. Purified RRV particles were successfully labeled with the Cy5 mono reactive dye, without decrease in virus infectivity, and the labeled viruses were clearly observed by confocal microscope. PAGE gel analysis showed that most viral proteins were labeled; including the intermediate capsid protein VP6. Only 2 out of 117 Cy5-labeled virus particles colocalized with newly formed viroplasms at 4 hours post-infection. Conclusions The results presented in this work suggest that during rotavirus infection the number and size of viroplasm increases in an MOI-dependent manner. The Cy5 in vitro labeled virus particles were not found to colocalize with newly formed viroplasms, suggesting that they are not involved in viroplasm nucleation.</p

Mycobacterium tuberculosis in vivo-expressed genes detection during active pulmonary tuberculosis

Indexación: Web of Science; ScieloEl estudio de la expresión génica de Mycobacterium tuberculosis ha involucrado la experimentación "in vitro ", "ex vivo " e "in vivo " (modelos animales), pero aún sin el éxito esperado. Proponemos que revelar los factores clave de la tuberculosis humana requiere investigar la expresión génica de M. tuberculosis dentro del ser humano ("in vivo "). Para ello, aislamos el mRNA total de M. tuberculosis, desde muestras clínicas respiratorias de pacientes con diagnóstico de tuberculosis pulmonar; posteriormente, sintetizamos el dscDNA y lo analizamos mediante RT-PCR cualitativo. Detectamos la expresión de la secuencia de inserción IS6110 y de los genes "housekeeping " 16SrRNA y sigA en M. tuberculosis creciendo in vivo (tuberculosis pulmonar) así como cultivado in vitro. La expresión de los genes mprA y mprB, que codifican el sistema de transducción de señales MprAB, sólo se detectó en M. tuberculosis crecido in vitro. Con nuestros resultados damos el primer paso hacia la implementación de un método no invasivo para el estudio del transcriptoma de M. tuberculosis, dentro de su único hospedero natural, con el fin de analizar la regulación "in vivo" de los determinantes genéticos requeridos para su virulencia y patogénesis.Mycobacterium tuberculosis gene expression studies have involved "in vitro", "ex vivo" and "in vivo" experiments (animal models), but without the expected success. We propose that key features of human tuberculosis could be discovered by studying the M. tuberculosis gene expression within the human host. Therefore, we isolated totalM. tuberculosis mRNA from human clinical respiratory specimens of patients diagnosed with pulmonary tuberculosis; after this, we synthesized the dscDNA and tested it by qualitative RT-PCR assays. We detected the expression of IS6110 insertion sequence and of the "housekeeping" genes 16SrRNA andsigA in M. tuberculosis grown in vivo (pulmonary tuberculosis) as well as grown in vitro M. tuberculosis. mprA and mprB genes expression, which code the MprAB signal transduction system, were only detected in M. tuberculosis grown in vitro. Our results provide the first step towards a non invasive methodfor the study of the transcriptome of M. tuberculosis within its native host, to analyze "in vivo" regulation of the genetic determinants required for virulence and pathogenesis.http://www.scielo.cl/pdf/rcher/v28n4/art04.pd

Improving Underrepresented Minority Student Persistence in STEM.

Members of the Joint Working Group on Improving Underrepresented Minorities (URMs) Persistence in Science, Technology, Engineering, and Mathematics (STEM)-convened by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute-review current data and propose deliberation about why the academic "pathways" leak more for URM than white or Asian STEM students. They suggest expanding to include a stronger focus on the institutional barriers that need to be removed and the types of interventions that "lift" students' interests, commitment, and ability to persist in STEM fields. Using Kurt Lewin's planned approach to change, the committee describes five recommendations to increase URM persistence in STEM at the undergraduate level. These recommendations capitalize on known successes, recognize the need for accountability, and are framed to facilitate greater progress in the future. The impact of these recommendations rests upon enacting the first recommendation: to track successes and failures at the institutional level and collect data that help explain the existing trends

Internet use and academic success in university students

El uso de la tecnología provoca cambios sociales. Esto incluye el trabajo en el ámbito universitario en donde está cambiando tanto la forma de ejercer la docencia como la forma de aprender y se requiere conocer el efecto del uso de la tecnología sobre el rendimiento del alumnado. En este trabajo se investigó la incidencia del uso de Internet sobre el éxito académico del alumnado de cinco universidades de Ecuador. Se levantó una muestra aleatoria de 4.697 personas y se las categorizó en perfiles de uso de Internet para actividades académicas y para entretenimiento, utilizando análisis factorial y análisis clúster. Las categorías resultantes se utilizaron como variables independientes en modelos de regresión logística multinomial que buscaban determinar si el uso de Internet tenía incidencia sobre el éxito académico. Los resultados muestran que quienes realizan actividades interactivas con pares y profesores o quienes utilizan de forma balanceada las distintas herramientas de Internet tienden a un mayor éxito académico que aquellos que solo buscan información. En lo referente al entretenimiento, se encontró una incidencia positiva del uso de Internet sobre el éxito académico. Los estudiantes que realizan descargas de contenido de audio, video y software, y quienes utilizan todas las posibilidades de entretenimiento, presentan menor tendencia a suspender que los estudiantes que utilizan mínimamente Internet. En cuanto al género se presentan diferencias en los usos académicos y de entretenimientoThe use of technology is changing the way things are done, including the work in universities where the teaching and learning process are changing, and it is required to know the effect of technology on student achievement. In this research work, we present the influence of Internet use on academic success of students from five universities in Ecuador. A random sample of 4,697 people was got up and categorized in two groups: the use of Internet in academic activities and entertainment, using factor analysis and cluster analysis; the resulting categories were used as independent variables in multinomial logistic regression model which are seeking to determine if the use of Internet has impacted on academic success. The results show that people who perform interactive activities with peers and teachers or use in a balanced way the different internet tools tend to have more academic success than those who only seeks information. Regarding to the use of Internet in entertainment, a positive impact was found on academic achievement. Students who download audio, video and software, and students who use all the entertainment possibilities show less likely to fail than who using minimally Internet. In terms of gender, it has different effects for entertainment and academic purpose

Internet Use and Academic Success in University Students = Usos de Internet y éxito académico en estudiantes universitarios

The use of technology is changing the way things are done, including the work in universities where the teaching and learning process are changing, and it is required to know the effect of technology on student achievement. In this research work, we present the influence of Internet use on academic success of students from five universities in Ecuador. A random sample of 4,697 people was got up and categorized in two groups: the use of Internet in academic activities and entertainment, using factor analysis and cluster analysis; the resulting categories were used as independent variables in multinomial logistic regression model which are seeking to determine if the use of Internet has impacted on academic success. The results show that people who perform interactive activities with peers and teachers or use in a balanced way the different internet tools tend to have more academic success than those who only seeks information. Regarding to the use of Internet in entertainment, a positive impact was found on academic achievement. Students who download audio, video and software, and students who use all the entertainment possibilities show less likely to fail than who using minimally Internet. In terms of gender, it has different effects for entertainment and academic purposes

Purificación y caracterización preliminar de proteasas del látex de Vasconcellea candicans (A. Gray) A. DC (Mito)

Preliminary studies indicate that, the "Mito" fresh latex, has a specific activity of papain from 1.84 times greater than that found in the latex of papaya, so the objective of this study was to purify and characterize "Mito" fresh latex proteases that have activity of papain. The crude extract protease was obtained from the "Mito" latex which was re-suspended (1:1) in 10 mM Na acetate buffer at pH 5.0; immediately proteins were precipitated at pH 9.0 and then with 45% ammonium sulfate. Subsequently, the proteins were purified on a Sephadex G-100 column and were three fractions: A, B and C. Using as a substrate casein, the enzymatic specific activity (ESA) was measured and was found to be the fraction A was 87.74 nkat.mg-1protein, for fraction B was 14.93 nkat.mg-1protein and for fraction C it was 16.13 nkat.mg-1protein. ESA of fraction A against papain of fresh latex of C. papaya was 13.3 times greater. Electrophoretic analysis (12% denaturant gel) shows for A fraction, two protein bands having one of them a relation similar to the papain standard. In addition, there was observed that the A fraction (papain of "Mito") against different concentrations of casein, used as a substrate, displays a michaeliane sigmoid curve; different volumes of enzyme shows a linear behavior; it has an optimum pH of 7.5 and is active up to 60 °C.Estudios preliminares indican que, el látex fresco del “Mito” tiene una actividad específica de papaína de 1,84 veces mayor a la encontrada en el látex of papaya, por lo que el objetivo de este trabajo fue purificar y caracterizar las proteasas del látex fresco del “Mito” que tuvieran actividad de papaína. El extracto crudo de proteasas se obtuvo a partir del látex de “Mito” el cual fue resuspendido (1:1) en buffer acetato de Na 10 mM a pH 5,0; inmediatamente se precipitaron proteínas a pH 9,0 y luego con sulfato de amonio al 45%. Posteriormente se purificó en una columna de Sephadex G-100 y se obtuvieron tres fracciones: A, B y C; utilizando como sustrato caseína se midió la actividad enzimática específica (AEE). Se encontró que para la Fracción A la AEE fue de 87,74 nkat.mg-1proteína, para la Fracción B fue de 14,93 nkat.mg-1proteína y para la Fracción C fue de 16,13 nkat.mg-1proteína. La AEE de la fracción A frente a la de papaína de látex fresco de C. papaya fue 13,3 veces mayor. En el análisis electroforético (gel desnaturalizante, 12%) se observa para la fracción A dos bandas de proteínas teniendo una de ellas una “relación de frente” semejante al estándar de papaína. Además, se observó que la fracción A (papaína de “Mito”) frente a diferentes concentraciones de caseína, usada como sustrato, presenta una curva sigmoidea michaeliana; a diferentes volúmenes de enzima se muestra un comportamiento lineal; tiene un pH óptimo a 7,5 y es activa hasta 60 ºC

Toughening of Nb2O5 doped zirconia biomaterial fabricated by microwave sintering technology

Pòster presentat a Euromat 2017, Thessaloniki (Greece), 17-22 september 2017The aim of this research is to investigate the characteristics and mechanical properties of Nb2O5 doped zirconia. Samples of partially stabilized-zirconia (3Y-TZP) with Nb2O5 in amounts of 0.15-1.5 mol.% were prepared by sol–gel technique and sintered by non-conventional microwave process