Rebrote después de incendio e inversión reproductiva en Erica cinerea y E. vagans

Se estudió el crecimiento anual y la distribución de recursos de clones control y de rebrotes en áreas incendiadas y en zonas control en Erica vagans y E. cinerea, encontrándose que no existen diferencias significativas entre ambas especies. Sin embargo, el crecimiento de los rebrotes tras el incendio fue superior al estimado en los controles. La asignación reproductiva en el rebrote después de incendios disminuyó en ambas especies, sobre todo en E. cinerea. Los patrones de asignación reproductiva dependientes del tamaño que aparecen en los controles no se encuentran en el rebrote, lo cual sugiere una asignación reproductiva plástica.Post-fire growth and annual growth of control branches were studied in Erica vagans and E. cinerea in two northem Spain localities. The dry weight of the resprouts was greater than that of the control branches. However, neither growth of the control branches nor resprouts differed among species. Reproductive allocation did not show differences among species, but significantly decreased in burned areas, specially in E. cinerea. Reproductive allocation was size-dependent in control branches, but this pattem did not appear in the resprouts. This variations suggest a flexible reproductive strategy

Export of Commercial Hass Avocados From Argentina Poses Negligible Risk of Ceratitis capitata (Diptera: Tephritidae) Infestation

Argentina has to meet quarantine restrictions because of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), to export 'Hass' avocados, Persea americana Miller, to certain countries. Hass avocado at the hard, mature green stage is potentially a conditional nonhost for C. capitata and could open export markets without the need for a quarantine treatment. Trapping data from 1998 to 2006 showed that C. capitata was present in avocado orchards, particularly early in the harvest season. The host status of hard, mature green Hass avocado to C. capitata was evaluated using laboratory and field cage tests under no-choice conditions and by assessing natural levels of infestation in commercially harvested fruit from the main avocado production area. In total, 2,250 hard, mature green avocado fruit were exposed to 11,250 gravid females for 24 or 48 h after harvest in laboratory or field cages, and no infestations were found. During 11 seasons, 5,949 fruit in total were sampled from the trees and 992 fruit were collected from the ground, and in none of them were any live or dead fruit fly larvae found. Inspection of >198,000 commercial fruit at the packinghouse from 1998 to 2011 showed no symptoms of fruit fly infestation. These data exceed the published standards for determination of nonhost status, as well as the Probit 9 standard for development of quarantine treatments. Hass avocado harvested at the hard, mature green stage was not infested by C. capitata and seems to pose a negligible quarantine risk. As a consequence, no postharvest treatment or other quarantine actions should be required by importing countries.Fil: Elvira Villagrán, M.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Willink, Eduardo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Vera, María Teresa. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Follett, Peter. United States Department Of Agriculture; Estados Unido

How personal resources predict work engagement and self-rated performance among construction workers: A social cognitive perspective

Traditionally, research focussing on psychosocial factors in the construction industry has focused mainly on the negative aspects of health and on results such as occupational accidents. This study, however, focuses on the specific relationships among the different positive psychosocial factors shared by construction workers that could be responsible for occupational well-being and outcomes such as performance. The main objective of this study was to test whether personal resources predict self-rated job performance through job resources and work engagement. Following the predictions of Bandura's Social Cognitive Theory and the motivational process of the Job Demands-Resources Model, we expect that the relationship between personal resources and performance will be fully mediated by job resources and work engagement. The sample consists of 228 construction workers. Structural equation modelling supports the research model. Personal resources (i.e. self-efficacy, mental and emotional competences) play a predicting role in the perception of job resources (i.e. job control and supervisor social support), which in turn leads to work engagement and self-rated performance. This study emphasises the crucial role that personal resources play in determining how people perceive job resources by determining the levels of work engagement and, hence, their self-rated job performance. Theoretical and practical implications are discussed

Factors influencing the production of recombinant SV40 vectors

Most gene therapy approaches employ viral vectors for gene delivery. Ideally, these vectors should be produced at high titer and purity with well-established protocols. Standardized methods to measure the quality of the vectors produced are imperative, as are techniques that allow reproducible quantitation of viral titer. We devised a series of protocols that achieve high-titer production and reproducible purification and provide for quality control and titering of recombinant simian virus 40 vectors (rSV40s). rSV40s are good candidate vehicles for gene transfer: they are easily modified to be nonreplicative and they are nonimmunogenic. Further, they infect a wide variety of cells and allow long-term transgene expression. We report here these protocols to produce rSV40 vectors in high yields, describe their purification, and characterize viral stocks using quality control techniques that monitor the presence of wild-type SV40 revertants and defective interfering particles. Several methods for reproducible titration of rSV40 viruses have been compared. We believe that these techniques can be widely applied to obtain high concentrations of high-quality rSV40 viruses reproducibly

Social Learning Analytics en la Educación Superior. Una experiencia en el Grado de Educación Primaria

The concept of Learning Analytics, as we understand it today, is relatively new but the practice of evaluating user behavior is not innovative. For years, technological development, along with other educational aspects, have encouraged, developed and facilitated this practice as a way of providing a personalized quality experience to students. The main goal of this study, carried out in the Primary Education Degree of the University of Murcia, was to research, from the perspective of Social Learning Analytics, how students learn and collaborate in online environments, specifically through their use of social media. With the idea of improving and optimizing future teaching experiences, a pilot study was conducted using weblog, Twitter and Facebook to work with different topics on the subject. The method used in this research was a participant observation and the analysis performed was both quantitative, based mainly on the data gathered from the learning analytics, and qualitative (analyzing students’ content from comments). Results show that there was greater interaction on Facebook than weblogs, where students interacted to deal with aspects related to the learning process and the topic of the subject. This exchange of information grew during the development of the experience. In addition, learning analytics shows that there is a relationship between group members and their interaction and behavior in networks.El concepto de Learning Analytics es relativamente nuevo tal como lo entendemos hoy en día, pero la práctica de evaluar el comportamiento del usuario a través de registros previos de actividad no lo es tanto. Con el tiempo, los avances tecnológicos, junto con otros factores educativos han alentado, desarrollado y facilitado esta práctica para proporcionar una experiencia personalizada de calidad al alumnado. El objetivo general de este estudio, realizado en el Grado de Educación Primaria de la Universidad de Murcia, se centra en conocer desde la perspectiva de Social Learning Analytics, cómo aprende y colabora el alumnado en entornos virtuales, específicamente a través de medios sociales. Con la idea de mejorar y optimizar futuras experiencias docentes, se llevó a cabo un estudio piloto en el que se usó Facebook, Twitter y un blog grupal para el desarrollo de las tareas de la asignatura. El método empleado en esta investigación ha sido el de la observación participante y el tipo de análisis realizado ha sido tanto cuantitativo, basado principalmente en los datos obtenidos de las propias analíticas de aprendizaje, como cualitativo (análisis de contenido de las intervenciones y comentarios del alumnado). Los resultados obtenidos muestran que hubo una mayor interacción en Facebook que en el blog grupal, donde los alumnos interaccionaban para tratar aspectos relacionados con el proceso de aprendizaje y la temática de la asignatura. Este intercambio de información fue creciendo durante el desarrollo de la experiencia. Además, las analíticas de aprendizaje muestran que existe una relación en cuanto a los miembros del grupo y sus interacciones y comportamientos en las redes

Biological and reproductive parameters of Helicoverpa armigera and Helicoverpa zea reared on artificial diet in Argentina

Helicoverpa armigera and H. zea (Lepidoptera Noctuidae) are genetically and physiologically closely related species that havemating compatibility under laboratory conditions. Considering the presence of H. armigera in Argentina, the lack information aboutits biology and evolutionary relationship with H. zea, the aim of this study was to compare biological, reproductive, populationparameters and biotic potential (BP) of both species under controlled conditions. Egg and larva duration showed significant differences,being in both cases the longest duration in H. zea. Pre-oviposition, oviposition, and post-oviposition duration, and fertilitypresented significant differences. The only population parameter that did not differ between H. armigera (96.95) and H. zea (104.78)was the net reproductive rate (R0). The maximum rate of population growth occurred in the day 34 and 46 for H. armigera andH. zea respectively. Biotic potential value indicated that each female of H. armigera and H. zea can produce more than 36 quintillionand 454 trillion descendants per year respectively. These analyses determined that H. armigera and H. zea have the potential toincrease quickly their populations under controlled conditions. The results obtained provide additional information to plan andimplement strategies for the integrated management of these species with emphasis in H. armigera in Argentina.Fil: Murúa, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Fogliata, Sofia Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina. Syngenta Company; ArgentinaFil: Herrero, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Vera, M. Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Casmuz, Augusto Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; ArgentinaFil: Sosa Gómez, Daniel. Embrapa Soja; Brasi

Graphene-Based Sensors for the Detection of Bioactive Compounds: A Review

Over the last years, different nanomaterials have been investigated to design highly selective and sensitive sensors, reaching nano/picomolar concentrations of biomolecules, which is crucial for medical sciences and the healthcare industry in order to assess physiological and metabolic parameters. The discovery of graphene (G) has unexpectedly impulsed research on developing cost-effective electrode materials owed to its unique physical and chemical properties, including high specific surface area, elevated carrier mobility, exceptional electrical and thermal conductivity, strong stiffness and strength combined with flexibility and optical transparency. G and its derivatives, including graphene oxide (GO) and reduced graphene oxide (rGO), are becoming an important class of nanomaterials in the area of optical and electrochemical sensors. The presence of oxygenated functional groups makes GO nanosheets amphiphilic, facilitating chemical functionalization. G-based nanomaterials can be easily combined with different types of inorganic nanoparticles, including metals and metal oxides, quantum dots, organic polymers, and biomolecules, to yield a wide range of nanocomposites with enhanced sensitivity for sensor applications. This review provides an overview of recent research on G-based nanocomposites for the detection of bioactive compounds, providing insights on the unique advantages offered by G and its derivatives. Their synthesis process, functionalization routes, and main properties are summarized, and the main challenges are also discussed. The antioxidants selected for this review are melatonin, gallic acid, tannic acid, resveratrol, oleuropein, hydroxytyrosol, tocopherol, ascorbic acid, and curcumin. They were chosen owed to their beneficial properties for human health, including antibiotic, antiviral, cardiovascular protector, anticancer, anti-inflammatory, cytoprotective, neuroprotective, antiageing, antidegenerative, and antiallergic capacity. The sensitivity and selectivity of G-based electrochemical and fluorescent sensors are also examined. Finally, the future outlook for the development of G-based sensors for this type of biocompounds is outlined

Graphene Oxides Derivatives Prepared by an Electrochemical Approach: Correlation between Structure and Properties

Graphene oxide (GO) can be defined as a single monolayer of graphite with oxygen-containing functionalities such as epoxides, alcohols, and carboxylic acids. It is an interesting alternative to graphene for many applications due to its exceptional properties and feasibility of functionalization. In this study, electrochemically exfoliated graphene oxides (EGOs) with different amounts of surface groups, hence level of oxidation, were prepared by an electrochemical two-stage approach using graphite as raw material. A complete characterization of the EGOs was carried out in order to correlate their surface topography, interlayer spacing, defect content, and specific surface area (SSA) with their electrical, thermal, and mechanical properties. It has been found that the SSA has a direct relationship with the d-spacing. The EGOs electrical resistance decreases with increasing SSA while rises with increasing the D/G band intensity ratio in the Raman spectra, hence the defect content. Their thermal stability under both nitrogen and dry air atmospheres depends on both their oxidation level and defect content. Their macroscopic mechanical properties, namely the Young's modulus and tensile strength, are influenced by the defect content, while no correlation was found with their SSA or interlayer spacing. Young moduli values as high as 54 GPa have been measured, which corroborates that the developed method preserves the integrity of the graphene flakes. Understanding the structure-property relationships in these materials is useful for the design of modified GOs with controllable morphologies and properties for a wide range of applications in electrical/electronic devices

Características citopatológicas del carcinoma de células acinares (CCA) de glándula salival: a propósito de cuatro observaciones

Objetivo: Presentar las características citopatológicas del carcinoma acinar (CCA), así como su correlación cito-histológica, comentando los problemas de diagnóstico diferencial de esta entidad en base a cuatro observaciones estudiadas mediante PAAF. Casos clínicos: Dos varones de 52 y 53 años, una mujer de 79 años, y una niña de 12 años que presentaron tumoraciones localizadas en territorio parotídeo (casos 1, 2 y 4), y a nivel laterocervical (caso 3). En tres pacientes, la PAAF fue, junto a los estudios de imagen, la primera aproximación diagnóstica; correspondiendo el caso 3 a una punción de adenopatías laterocervicales metastásicas en una paciente con antecedentes de CCA de parótida. Hallazgos citológicos: Las extensiones citológicas mostraron abundante celularidad tumoral dispuesta en pequeñas placas monocapa, formando estructuras acinares, o como células aisladas. Es de destacar la abundancia de núcleos desnudos en el fondo de los frotis, y la ausencia de grasa y de epitelio ductal. Las células poseían núcleos monomorfos redondeados u ovales, nucleólo poco evidente y abundante citoplasma granular o finamente vacuolado. Discusión: La PAAF proporciona información esencial en la actuación diagnóstico-terapeútica de las tumoraciones de la glándula salival, resultando esta metodología muy sensible en su eficacia diagnóstica. La identificación de los CCA frecuentemente presenta dificultades, debido a la gran similitud citológica de las células tumorales con el componente acinar normal propio de la glándula salival. El diagnóstico diferencial se plantea, fundamentalmente, con carcinomas de células claras, con carcinomas mucoepidermoides, con el tumor de Warthin y con los oncocitomas. Nuestras observaciones confirman la validez de la PAAF en una primera aproximación diagnóstica de estas lesiones tumorales accesibles a la punción directa.Objective: To present the cytopathological characteristics of acinic cell carcinoma (ACC) as well as its cyto-histological correlation, commenting on the differential diagnostic problems of this entity based on four observations studied using fine-needle aspiration biopsy (FNAB). Clinical Cases: Two males of 52 and 53 years of age, one 79 year-old woman and a girl of 12 years of age, who presented tumors located in the parotid area (cases 1, 2 and 4) and at the laterocervical level (case 3). In 3 patients, the FNAB was, together with the image studies, the first diagnostic indication; case 3 corresponding to a puncture of metastatic laterocervical adenopathies in a patient with a history of parotid ACC. Cytological findings: The cytologic smears revealed abundant tumoral cellularity arranged in small monolayered sheets, forming acinar structures or isolated cells. The abundance of bare nuclei at the background of the smears, and the absence of adipose tissue and ductal epithelium are highlighted. The cells possessed round or oval monomorphic nuclei, few nucleoli and abundant granular or finely vacuolate cytoplasm. Discussion: FNAB provides essential information on the diagnostic- therapeutic management of salivary gland tumors; this methodology is highly sensitive in its diagnostic efficacy. The diagnosis of ACCs frequently presents difficulties, owing to the great cytologic similarity of the tumor cells with the normal acinar component of the salivary gland. The differential diag-nosis is considered, fundamentally, with clear cell carcinomas, mucoepidermoid carcinomas, Warthin's tumor, and oncocytomas. Our observations confirm the validity of FNAB in a first diagnostic approximation for those lesions accessible to direct puncture

Experiencia de uso de ECATHS en Quimica Inorgánica

Es objetivo de esta comunicación presentar los resultados de una encuesta en la que se indagó en alumnos ingresantes a carreras de orientación química sobre el uso y la utilidad del espacio virtual Ecaths creado en el año 2012 en la Asignatura Química Inorgánica, Facultad de Ciencias Exactas y Naturales y Agrimensura de la Universidad Nacional del Nordeste (Argentina). A través de los enlaces del Aula, se generó un espacio de interacción virtual como complemento y fortalecimiento de las actividades desarrolladas presencialmente. De acuerdo a las respuestas de los usuarios, ha resultado un medio apropiado para obtener información relevante y actualizada acerca de diferentes cuestiones generales, rever sus errores, manifestar y aclarar dudas, reforzar el estudio domiciliario, además de contribuir a una fluida comunicación en línea entre docentes y alumnos