Crecimiento de renovales de Drimys winteri después de 16 años de aplicados distintos tratamientos de raleo en las cordilleras de los andes y de la costa en Chile

Secondary Drimys winteri forests are among the most common and productive forests in south-central Chile. However, their management has been scarce or many times inadequate due to lack of silvicultural knowledge. In 1986 and 1990 three field experiments were installed; one in the Coastal range of the province of Ranco (40° 09' S) and two in the Andean range of the province of Llanquihue (41° 30' S), to evaluate the effects of different intensities of thinning on the growth and mortality of 28-year-old Drimys winteri secondary forests. After 16 and 10 years of evaluation, great differences were observed among treatments within and between the three experiments. In Hueicoya (Coastal Range) plots thinned at a distance of 3 m had the highest productivity. In Lenca A (Andean Range) the high mortality rates due to windfalls in the plots with trees spaced at 3 and 4 m caused the control plots to have the highest productivity rates. In Lenca B (Andean Range) plots thinned at 2.5 m distance between trees had no significant differences with control plots. At an equal thinning intensity the responses were very different among experiments. We discuss that site quality, residual composition, exposure to winds and rooting characteristics may have influenced these results. In general, it is recommended to thin at 25-45% residual densities (2-3 m distance between trees at the age of thinning of 9-12 cm quadratic stand diameter), but always depending on the risk of windfall

Biological synthesis of fluorescent nanoparticles by cadmium and tellurite resistant Antarctic bacteria: exploring novel natural nanofactories

Indexación: Web of ScienceBackground: Fluorescent nanoparticles or quantum dots (QDs) have been intensely studied for basic and applied research due to their unique size-dependent properties. There is an increasing interest in developing ecofriendly methods to synthesize these nanoparticles since they improve biocompatibility and avoid the generation of toxic byproducts. The use of biological systems, particularly prokaryotes, has emerged as a promising alternative. Recent studies indicate that QDs biosynthesis is related to factors such as cellular redox status and antioxidant defenses. Based on this, the mixture of extreme conditions of Antarctica would allow the development of natural QDs producing bacteria. Results: In this study we isolated and characterized cadmium and tellurite resistant Antarctic bacteria capable of synthesizing CdS and CdTe QDs when exposed to these oxidizing heavy metals. A time dependent change in fluorescence emission color, moving from green to red, was determined on bacterial cells exposed to metals. Biosynthesis was observed in cells grown at different temperatures and high metal concentrations. Electron microscopy analysis of treated cells revealed nanometric electron-dense elements and structures resembling membrane vesicles mostly associated to periplasmic space. Purified biosynthesized QDs displayed broad absorption and emission spectra characteristic of biogenic Cd nanoparticles. Conclusions: Our work presents a novel and simple biological approach to produce QDs at room temperature by using heavy metal resistant Antarctic bacteria, highlighting the unique properties of these microorganisms as potent natural producers of nano-scale materials and promising candidates for bioremediation purposes.http://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-016-0477-

Integrated economic-hydrologic water modeling at the basin scale: the Maipo river basin

Increasing competition for water across sectors increases the importance of the river basin as the appropriate unit of analysis to address the challenges facing water resources management; and modeling at this scale can provide essential information for policymakers in their resource allocation decisions. This paper introduces an integrated economic-hydrologic modeling framework that accounts for the interactions between water allocation, farmer input choice, agricultural productivity, nonagricultural water demand, and resource degradation in order to estimate the social and economic gains from improvement in the allocation and efficiency of water use. The model is applied to the Maipo River Basin in Chile. Economic benefits to water use are evaluated for different demand management instruments, including markets in tradable water rights, based on production and benefit functions with respect to water for the agricultural and urban-industrial sectors.Resource allocation., Water resources development Chile., Chile.,

Sobre el Jurásico del Mencal y su relación con otras series sub-béticas de la transversal de Granada

Se describen nuevos términos pertenecientes a la serie jurásica del Mencal (Morrón de la Meseta), junto con otros de un corte próximo a Iznalloz (Granada). Ambas series se correlacionan entre si y con otras series que constituyen un umbral en la cuenca sedimentaria subbética

Reliability and validity of an instrument that uses photographs to measure the ability for differential diagnosis of injuries caused by pressure and/or incontinence

Indexación: Scopus; Scielo.Objetivo: Evaluar la fiabilidad y validez de un instrumento que permite medir la habilidad visual para identificar y clasificar Dermatitis Asociada a Incontinencia (DAI), Ulceras por Presión (UPP) y lesiones mixtas, por parte de profesionales de enfermería. Material y método: Se aplicó un instrumento autoadministrado conformado por 14 fotografías a una muestra por conveniencia de 28 profesionales de enfermería, donde se debía identificar la lesión y luego clasificar su estado de avance. A modo exploratorio se calculó la fiabilidad anidada con Alpha de Cronbach y la validez con Análisis de Componentes Principales (ACP). Resultados: La fiabilidad inicial de las 14 fotografías (Alpha de Cronbach= 0,174) fue baja y tras eliminar 7 la fiabilidad fue aceptable (Alpha de Cronbach= 0,709). Se estableció la presencia de dos dimensiones: por un lado, la habilidad de diagnosticar DAI que explica un 35% de la varianza y, por otro, la habilidad de diagnosticar UPP, que explica el 22% de la varianza, ya sea que se encuentren separadas o juntas en un mismo paciente. Las lesiones DAI son diagnosticadas en mayor proporción que las lesiones mixtas. Conclusión: El estudio aportó 6 fotografías fiables y válidas que pueden ser utilizadas en futuros trabajos para construir un instrumento más robusto que pueda ser utilizado en Chile para la capacitación en el área. La muestra estudiada tiene fortalezas en el diagnóstico de DAI y dificultades en el diagnóstico de lesiones mixtas.Aim: To evaluate the reliability and validity of an instrument that allows to measure the visual ability to identify and classify Incontinence Associated Dermatitis (IAD), Pressure Ulcers (PU) and mixed lesions, by nursing professionals. Material and method: A self-administered instrument consisting of 14 photographs was applied to a convenience sample of 28 nurses. A set of 14 photographs were shown in which they were asked to identify and then classify the state of the lesion. In an exploratory manner, the nested reliability was calculated with Cronbach’s Alpha and the validity with Principal Component Analysis (PCA). Results: The initial reliability of the 14 photographs was low (Cronbach Alpha = 0.174), after removing 7 photographs the reliability became acceptable (Cronbach Alpha = 0.709). The presence of two dimensions was established: on the one hand the ability to diagnose IAD, which explains 35% of the variance, and secondly, the ability to diagnose PU, which explains 22% of the variance, whether they are separated or together in the same patient. IAD is better diagnosed than mixed lesions. Conclusion: The study provided 6 reliable and valid photos that can be used in future work to build a more robust instrument that can be used in Chile for training in the area. The studied sample shows strengths when diagnosing IAD and difficulties when diagnosing mixed lesions. © 2017, Universidad de Concepcion. All rights reserved.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-95532017000300059&lng=en&nrm=iso&tlng=e

The macroecology of chemical communication in lizards: do climatic factors drive the evolution of signalling glands?

Chemical communication plays a pivotal role in shaping sexual and ecological interactions among animals. In lizards, fundamental mechanisms of sexual selection such as female mate choice have rarely been shown to be influenced by quantitative phenotypic traits (e.g., ornaments), while chemical signals have been found to potentially influence multiple forms of sexual and social interactions, including mate choice and territoriality. Chemical signals in lizards are secreted by glands primarily located on the edge of the cloacae (precloacal glands, PG) and thighs (femoral glands), and whose interspecific and interclade number ranges from 0 to >100. However, elucidating the factors underlying the evolution of such remarkable variation remains an elusive endeavour. Competing hypotheses suggest a dominant role for phylogenetic conservatism (i.e., species within clades share similar numbers of glands) or for natural selection (i.e., their adaptive diversification results in deviating numbers of glands from ancestors). Using the prolific Liolaemus lizard radiation from South America (where precloacal glands vary from 0-14), we present one of the largest-scale tests of both hypotheses to date. Based on climatic and phylogenetic modelling, we show a clear role for both phylogenetic inertia and adaptation underlying gland variation: (i) solar radiation, net primary productivity, topographic heterogeneity and precipitation range have a significant effect on number of PG variation, (ii) humid and cold environments tend to concentrate species with a higher number of glands, (iii) there is a strong phylogenetic signal that tends to conserve the number of PG within clades. Collectively, our study confirms that the inertia of niche conservatism can be broken down by the need of species facing different selection regimes to adjust their glands to suit the demands of their specific environments

Constructing a WISE High Resolution Galaxy Atlas

After eight months of continuous observations, the Wide-field Infrared Survey Explorer (WISE) mapped the entire sky at 3.4 {\mu}m, 4.6 {\mu}m, 12 {\mu}m and 22 {\mu}m. We have begun a dedicated WISE High Resolution Galaxy Atlas (WHRGA) project to fully characterize large, nearby galaxies and produce a legacy image atlas and source catalogue. Here we summarize the deconvolution technique used to significantly improve the spatial resolution of WISE imaging, specifically designed to study the internal anatomy of nearby galaxies. As a case study, we present results for the galaxy NGC 1566, comparing the WISE super-resolution image processing to that of Spitzer, GALEX and ground-based imaging. The is the first paper in a two part series; results for a much larger sample of nearby galaxies is presented in the second paper.Comment: Published in the AJ (2012, AJ, 144, 68

Exigência térmica e caracterização fenológica da videira Syrah no Vale do Rio São Francisco.

O objetivo deste trabalho foi caracterizar o comportamento fenológico da videira Syrah produzida no Submédio São Francisco, bem como caracterizar sua exigência térmica em grausdia. A área experimental foi instalada em um parreiral comercial pertencente à Fazenda Ouro Verde, Casa Nova, BA. As avaliações tiveram início a partir da poda de produção, realizada no primeiro e segundo semestres dos anos de 2005 e 2006. A fenologia das plantas foi avaliada quanto à duração em dias de cada um dos seguintes subperíodos: da poda à brotação, da poda à plena floração, da poda ao pintor (início da maturação das uvas) e da poda à colheita. A exigência térmica da videira Syrah foi calculada pelo somatório dos graus dia da poda até a colheita para os quatro ciclos de produção, bem como para cada um dos subperíodos fenológicos, considerando a temperatura base de 10°C. Os resultados mostraram que a duração do ciclo da poda à colheita da variedade de videira Syrah no Vale do Rio São Francisco é de 118 dias e sua exigência térmica é de 1.939,3 graus dia