Aspectos tecnológicos para la producción de maíz en Colombia.

Se describe de manera general la situación del cultivo de maiz para el año 1988. La superficie cultivada para cada uno de los últimos 10 años, los rendimientos y la producción por departamentos. Igualmente la utilización de insumos y los materiales mejorados disponibles para el semestre A de 1988. Se indican las limitantes tecnológicas y la oferta tecnológica del cultivo. Se relacionan los materiales mejorados disponibles de maiz por regiones y su rendimiento. Se describen los fundamentos tecnológicos del plan de producción de maiz, señalando los Centros de investigación donde se llevará a cabo y los proyectos de investigación que en ellos se adelantarán en el cultivo. Adicionalmente se hace referencia a las acciones de transferencia de tecnología, ajuste tecnológico, divulgación y capacitación y otros servicios técnicos de apoyo disponibles para el plan, así como los recursos y la cooperación internacional requeridaMaíz-Zea may

Sección 4: Vulnerabilidad socioeconómica del sector pesquero argentino al cambio climático

En primer lugar se caracterizan los aspectos más relevantes de las dimensiones económica y social del sector pesquero argentino. Luego se realizó un análisis de la vulnerabilidad socioeconómica del sector pesquero argentino, sobre la base de las propuestas del IPCC (2014), Allison et al. (2009) y Blasiak et al. (2017).Fil: Gaviola, Saúl Ricardo. Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP); Argentina.Fil: Verón, E. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Prosdocimi, L. Ministerio de Agricultura Ganadería y Pesca. Subsecretaría de Agricultura, Ganadería y Pesca; Argentina.Fil: De la Garza, J. Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP); Argentina.Fil: Martínez, P. Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP); Argentina.Fil: Navarro, G. Ministerio de Agricultura Ganadería y Pesca. Subsecretaría de Agricultura, Ganadería y Pesca; Argentina.Fil: Pájaro, M. Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP); Argentina.Fil: Piedrabuena, C. Ministerio de Agricultura Ganadería y Pesca. Subsecretaría de Agricultura, Ganadería y Pesca; Argentina.Fil: Rotta, Lautaro Daniel. Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP); Argentina

Comparación de la actividad in vitro de la tigeciclina mediante la prueba de difusión con disco, el método demicrodilución manual y el sistema automatizado Vitek 2

La tigeciclina es un antibiótico de amplio espectro conactividad frente a bacterias multirresistentes. Existen dificultades en la determinación de la actividad in vitro a travésde las técnicas microbiológicas convencionales. El objetivo del estudio fue evaluar tres marcas diferentes de medioagar Mueller-Hinton para utilizar en el método de difusión con disco y el método automatizado Vitek 2, y compararloscon la prueba tradicional de microdilución manual (Paneles Trek) frente a 200 aislamientos de microorganismos gramnegativos (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens y Acinetobacterbaumannii). Para el grupo de las enterobacterias, el medio con mejor desempeño fue el producido por Becton Dickinson,que tuvo 32,5% de errores menores y 3,8% de errores mayores. No se presentaron errores mayores con ningúnmedio. Se encontró una alta concordancia (94%) entre el método de microdilución manual y el Vitek 2. Para A.baumannii, el medio con mejor desempeño fue el Mueller-Hinton elaborado por Becton Dickinson, con 12,5% deerrores menores y 2,5% de errores mayores. Los resultados sugieren que el método Vitek 2 es una herramienta válidaen la determinación de la sensibilidad a la tigeciclina y que existen diferencias muy grandes en la prueba de difusióncon disco según la marca comercial de medio utilizado.Q4Q3Artículo breve208-211Tigecycline is a broad spectrum antibiotic having activity against multiresistant isolates. In vitro susceptibility testing is difficult to perform with the use of traditional microbiological techniques. The aim of this study was to evaluate the disk diffusion test with three different Mueller-Hinton agar brands, and the Vitek 2 automated system in comparison with the standard broth microdilution method against 200 gram-negative isolates (Escherichia coil, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens and Acinetobacter baumannii). Among Enterobacteriaceae, the Becton Dickinson agar had the lowest rate of minor (32.5%) and major errors (3.8%). No very major errors were found. For A. baumanni, the rate of minor and major errors was lower. A high rate of agreement (94%) was found between the broth microdilution method and the Vitek 2 system. Our results show that there are important differences between agars used for the disk diffusion test, and that Vitek 2 is a valid tool for susceptibility testing in clinical laboratories

e-Learning quality assessment in higher education: A mapping study

Quality assessment is today a success factor and a guarantee in the implementation and development of countless initiatives, programs and strategies in a very wide variety of fields. For this reason, in an educational field in a constant transformation, the evaluation of the quality of each process, phase and tool must be understood as an essential and basic part in teaching, betting on the implementation of quality evaluation processes in the virtual environment and also trying to adapt reality to new learning environments. In the present moment, in a society in which everything has to be evaluated, the establishment of evaluation standards for new instruments and the standardization of accepted and validated processes will also make virtual teaching-learning environments more reliable and effective. This research proposes a mapping study with the aim to find out the situation in which the research on quality evaluation in e-Learning in higher education finds itself. The criteria used for the selection of publications are concise and the complete process carried out is reflected in each of its phases. The results allow us to describe the current reality in a temporal perspective and the state of the art, in order to address the potential future lines of research in the field of quality assessment in virtual environments

Interaction Between Convection and Pulsation

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different formulations for how the convective turbulent velocity field couples with the global stellar oscillations. In this review we put emphasis on two, widely used, time-dependent convection formulations for estimating pulsation properties in one-dimensional stellar models. Applications to pulsating stars are presented with results for oscillation properties, such as the effects of convection dynamics on the oscillation frequencies, or the stability of pulsation modes, in classical pulsators and in stars supporting solar-type oscillations.Comment: Invited review article for Living Reviews in Solar Physics. 88 pages, 14 figure

Qualitative characteristics of meat from confined crossbred heifers fed with lipid sources

Lipids have been used in ruminant feed to replace high amounts of grain for increasing the diet energy density, performance and meat quality. This study evaluated the qualitative characteristics of meat from feedlot heifers fed with sources of lipid supplements. Twenty-one crossbred heifers (1/4Nelore × 1/4Santa Gertrudis × 1/2Braunvieh) were used. Each heifer received 60 % forage with a base of corn silage and 40 % concentrate, resulting in 5.8 % lipid content in the total diet. The following sources of lipids were used: soybeans, protected fat and soybean oil. There were no differences on physical characteristics of meat samples from heifers fed with the lipid sources. Soybeans increased the concentration of linoleic acid, content of polyunsaturated fatty acid and activity of the Δ9-desaturase C16 enzyme in the Longissimus muscle. The use of soybean oil in the diet increased the oleic acid, monounsaturated fatty acid, total cis- and trans-fatty acids (C18:0) and the activity of the Δ9-desaturase C16 enzyme in the subcutaneous fat. Diets with soybean grain had greater deposition of linoleic and linolenic acids than diets with fat protected and greater presence of these essential fatty acids are associated to a better composition and meat quality

Broker Fixed: The Racialized Social Structure and the Subjugation of Indigenous Populations in the Andes

Responding to calls to return racial analysis to indigenous Latin America, this article moves beyond the prejudicial attitudes of dominant groups to specify how native subordination gets perpetuated as a normal outcome of the organization of society. I argue that a naturalized system of indirect rule racially subordinates native populations through creating the position of mestizo “authoritarian intermediary.” Natives must depend on these cultural brokers for their personhood, while maintaining this privileged position requires facilitating indigenous exploitation. Institutional structures combine with cultural practices to generate a vicious cycle in which increased village intermediary success increases native marginalization. This racialized social structure explains my ethnographic findings that indigenous villagers continued to support the same coterie of mestizos despite their regular and sometimes extreme acts of peculation. My findings about the primacy of race suggest new directions for research into indigenous studies, ethnic mobilizations, and the global dimensions of racial domination

Bovine Lactoferrin Counteracts Toll-Like Receptor Mediated Activation Signals in Antigen Presenting Cells

Lactoferrin (LF), a key element in mammalian immune system, plays pivotal roles in host defence against infection and excessive inflammation. Its protective effects range from direct antimicrobial activities against a large panel of microbes, including bacteria, viruses, fungi and parasites, to antinflammatory and anticancer activities. In this study, we show that monocyte-derived dendritic cells (MD-DCs) generated in the presence of bovine LF (bLF) fail to undergo activation by up-modulating CD83, co-stimulatory and major histocompatibility complex molecules, and cytokine/chemokine secretion. Moreover, these cells are weak activators of T cell proliferation and retain antigen uptake activity. Consistent with an impaired maturation, bLF-MD-DC primed T lymphocytes exhibit a functional unresponsiveness characterized by reduced expression of CD154 and impaired expression of IFN-γ and IL-2. The observed imunosuppressive effects correlate with an increased expression of molecules with negative regulatory functions (i.e. immunoglobulin-like transcript 3 and programmed death ligand 1), indoleamine 2,3-dioxygenase, and suppressor of cytokine signaling-3. Interestingly, bLF-MD-DCs produce IL-6 and exhibit constitutive signal transducer and activator of transcription 3 activation. Conversely, bLF exposure of already differentiated MD-DCs completely fails to induce IL-6, and partially inhibits Toll-like receptor (TLR) agonist-induced activation. Cell-specific differences in bLF internalization likely account for the distinct response elicited by bLF in monocytes versus immature DCs, providing a mechanistic base for its multiple effects. These results indicate that bLF exerts a potent anti-inflammatory activity by skewing monocyte differentiation into DCs with impaired capacity to undergo activation and to promote Th1 responses. Overall, these bLF-mediated effects may represent a strategy to block excessive DC activation upon TLR-induced inflammation, adding further evidence for a critical role of bLF in directing host immune function