Variaciones Intra-Específicas en el crecimiento primario de Nothofagus dombeyi (Nothofagaceae Intra-specific variations in the primary growth of Nothofagus dombeyi (Nothofagaceae

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Javier Puntieri

2005-07-01

Full Text Available Se evaluó el patrón de crecimiento bajo condiciones controladas de los ejes foliados de 16 plántulas de Nothofagus dombeyi. Los individuos fueron ubicados en una cámara de crecimiento y se evaluó el crecimiento del tronco en dos eventos de crecimiento sucesivos (julio 2002 - marzo 2004. Se identificaron tres patrones de crecimiento del primer brote medido: (1 crecimiento ininterrumpido por unos 8 meses, (2 crecimiento interrumpido por un período de reposo no menor de 7 semanas, con rebrote posterior y (3 crecimiento ininterrumpido por 6 a 7 meses. En los individuos con los patrones de crecimiento 1 y 2, la tasa máxima de producción de hojas del primer brote producido fue mayor que en los individuos con el tercer patrón de crecimiento. La tasa media de crecimiento fue mayor para los brotes del primer grupo que para los de los otros dos grupos. El segundo de los brotes medidos se alargó en un único pulso y alcanzó menor tamaño que el primero de los brotes. Se discute el posible rol de gradientes ontogenéticos o de variaciones genéticas entre individuos de coihue como explicación de los diferentes patrones de crecimiento registrados.

Encapsulado de Embriones Somáticos y Embriones Cigóticos para Obtención de Semillas Artificiales de Raulí (Nothofagus alpina (Poepp. & Endl.) Oerst.)

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Cartes R, Priscila; Castellanos B, Hermes; Ríos L, Darcy; Sáez C, Katia; Spierccolli H, Scarlette; Sánchez O, Manuel

2009-01-01

Somatic and zygotic embryos from mature seeds of rauli-beech, Nothofagus alpina (Poepp. & Endl.) Oerst., were encapsulated in different artificial endosperms in order to generate a cover that fulfills the function of nourishment and protection of the embryos, facilitating their later germination. The content of sodium alginate varied by 4%, 3%, and 2%, as did the immersion time in calcium chloride (CaCl2), which acts as complexing agent. The artificial endosperm components of the Murashige an...

Micropropagación in vitro de Nothofagus alpina utilizando fitohormonas

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Luz García Cruzatty

2015-09-01

Full Text Available Nothofagus alpina es una de las especies forestales más importantes del Sur de Chile y Argentina, países donde se ha empezado con programas de mejoramiento genético. La micropropagación es una técnica muy útil en la clonación de árboles con fines de mejoramiento, por tanto, los objetivos planteados en esta investigación fueron: determinar la mejor concentración de fitohormonas 6-bencilaminopurina (BAP y ácido indol butírico (AIB y, el medio de cultivo idóneo para inducir el enraizamiento de brotes y la brotación de secciones nodales de N. alpina. Se evaluaron los medios de Murashige Skoog (MS y Wood Plant Medium (WPM, con la mitad de los macronutrientes (enraizamiento y los micronutrientes completos (multiplicación, suplementado con peptone (0.1%, sacarosa (2.0%, agar (0.7% y diferentes concentraciones de auxinas. El medio MS suplementado con 2 mg L-1 de AIB resultó mejor para inducir la producción de las raíces, tanto en número como en la longitud de la raíz principal. El mayor porcentaje de enraizamiento se registró en el medio WPM suplementado con 2 mg L-1 AIB. Los tratamientos para inducir multiplicación que incluyeron citoquinina originaron callos y no enraizaron; siendo mayor la presencia de callos en el medio WPM. Se sugiere que la aplicación de citoquininas no es indispensable para la brotación, puesto que en los tratamientos testigos hubo una buena brotación; lo que hace suponer que el material vegetal utilizado tiene suficiente niveles endógenos de esta fitohormona.

Surface-bound phosphatase activity in living hyphae of ectomycorrhizal fungi of Nothofagus obliqua.

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Alvarez, Maricel; Godoy, Roberto; Heyser, Wolfgang; Härtel, Steffen

2004-01-01

We determined the location and the activity of surface-bound phosphomonoesterase (SBP) of five ectomycorrhizal (EM) fungi of Nothofagus oblique. EM fungal mycelium of Paxillus involutus, Austropaxillus boletinoides, Descolea antartica, Cenococcum geophilum and Pisolithus tinctorius was grown in media with varying concentrations of dissolved phosphorus. SBP activity was detected at different pH values (3-7) under each growth regimen. SBP activity was assessed using a colorimetric method based on the hydrolysis of p-nitrophenyl phosphate (pNPP) to p-nitrophenol phosphate (pNP) + P. A new technique involving confocal laser-scanning microscopy (LSM) was used to locate and quantify SBP activity on the hyphal surface. EM fungi showed two fundamentally different patterns of SBP activity in relation to varying environmental conditions (P-concentrations and pH). In the cases of D. antartica, A. boletinoides and C. geophilum, changes in SBP activity were induced primarily by changes in the number of SBP-active centers on the hyphae. In the cases of P. tinctorius and P. involutus, the number of SBP-active centers per μm hyphal length changed much less than the intensity of the SBP-active centers on the hyphae. Our findings not only contribute to the discussion about the role of SBP-active centers in EM fungi but also introduce LSM as a valuable method for studying EM fungi.

Morfología y Anatomía del Ápice Caulinar de Nothofagus dombeyi (Nothofagaceae a lo largo de un año Morfology and anatomy of the shoot apex of Nothofagus dombeyi (Nothofagaceae along a year

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Soledad García

2006-07-01

Full Text Available En el presente estudio se evaluó la posible variación anual de la morfología y la anatomía del ápice caulinar de coihue, Nothofagus dombeyi (Nothofagaceae. A partir de muestras tomadas a lo largo de un año calendario, se realizaron cortes longitudinales de las yemas terminales con micrótomo de congelación. Independientemente de la época del año, una yema terminal está conformada por un meristema apical y rudimentos de tallo y hojas. Los primordios foliares proximales tienen mayor tamaño y grado de diferenciación que los distales. En la axila de cada estípula se destaca la presencia de coléteres. Cada coléter se comunica vascularmente con la estípula correspondiente. El número de primordios foliares por yema es constante entre abril y octubre y disminuye posteriormente al incrementarse el número de hojas expandidas, aunque sin llegar a cero. Al final de la estación de crecimiento se distinguen yemas de mayor y yemas de menor tamaño; estas últimas se secan y desprenden del tallo antes de la primavera siguiente. Dentro de una yema se evidencian, en un momento dado, distintos grados de diferenciación entre primordios foliares proximales y distales y entre la lámina y las estípulas de los primordios más proximales.The present study evaluates the possible annual variation in the morphology and anatomy of the shoot apex of Nothofagus dombeyi (Nothofagaceae. From samples taken over one year, longitudinal slices of terminal buds were cut with a freezing microtome. Irrespective of the time of the year, a terminal bud consists of an apical meristem and rudiments of stem and leaves. Proximal primordia are larger and have a higher degree of differentiation than distal primordia. Around the axil of each stipule colleters are present. Each colleter is connected with the corresponding stipule through a conducting strand. The number of leaf primordia per bud is constant between April and October and diminishes later on as leaf expansion

Experimentação política da amizade em comunidades da internet a partir da teoria dos afetos de Espinosa

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Lívia Godinho Nery Gomes Azevedo

2015-08-01

Full Text Available A compreensão da amizade em sua qualidade política designa um vínculo privilegiado de abertura à alteridade que permite ao corpo experimentações de afetar outros corpos e por eles ser afetado, cujos efeitos podem suscitar transformações na potência de agir. A concepção do corpo em Espinosa, sustentada pela unidade corpo-alma e capacidade de afeto, constitui um elemento precioso para a compreensão da presença e das intensidades afetivas em jogo nas relações de amizades na internet, as quais excluem contato físico. O presente projeto buscou investigar e analisar a maneira com que as comunidades na internet estão sendo utilizadas favorecendo a experimentação política da amizade. As narrativas revelaram que as comunidades da internet se constituem um espaço propício de trocas de ideias e experiências que aumentam a capacidade de reflexão dos sujeitos. As relações mediadas pela internet também favorecem novos modos de organização política e de exercício da cidadania.

Patrones de dispersión de semillas y colonización de Misodendrum punctulatum (Misodendraceae en un matorral postfuego de Nothofagus antarctica (Nothofagaceae del noroeste de la Patagonia Misodendrum punctulatum (Misodendraceae seed dispersal and colonization patterns on a Nothofagus antarctica (Nothofagaceae post-fire shrubland from Northwestern Patagonia

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NORLAN TERCERO-BUCARDO

2010-01-01

Full Text Available El patrón espacial de la dispersión puede afectar el patrón espacial de establecimiento condicionando la estructura de la vegetación. Este trabajo analiza la magnitud de la dispersión y la colonización (infección de la planta hemiparásita Misodendrum punctulatum (Misodendraceae. Este estudio fue realizado en un matorral postfuego de Nothofagus antárctica (hospedador. Nuestra hipótesis plantea que el patrón de dispersión anemófila de las semillas de M. punctulatum condiciona el patrón de infección (colonización sobre N. antárctica y que ambos procesos (dispersión y colonización son asimétrico en la misma dirección en función del viento predominante. Se evaluó la dispersión a campo contando el número de semillas sobre troncos y ramas desde arbustos remanentes infectados (hospedadores focales hacia cada punto cardinal. La colonización se evaluó registrando el número de infecciones sobre cada hospedador a lo largo de franjas trazadas hacia cada orientación desde los arbustos focales. Se observó que la cantidad de semillas dispersadas declina con la distancia desde la fuente de semillas, ajustándose a una distribución exponencial negativa. La mayor distancia de dispersión primaria fue de 10 m hacia el este. Respecto a la colonización la mayor distancia de nuevos establecimientos fue 22.5 m en dirección sur. Por otro lado, el número de infecciones desde los arbustos focales fue menor al oeste (1 infectado: 10 no infectados que en las otras direcciones (1 infectado: 6 no infectados. Ambos procesos presentaron un patrón de distribución similar y asimétrica como consecuencia de la dirección de los vientos predominantes y se observó una alta correlación espacial entre la dispersión de semillas y el establecimiento de las infecciones. Estos resultados de dispersión y colonización permiten comprender los patrones de distribución espacial de esta planta hemiparásita y entender su dinámica de infección. Los

Individual-Tree Diameter Growth Models for Mixed Nothofagus Second Growth Forests in Southern Chile

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Paulo C. Moreno

2017-12-01

Full Text Available Second growth forests of Nothofagus obliqua (roble, N. alpina (raulí, and N. dombeyi (coihue, known locally as RORACO, are among the most important native mixed forests in Chile. To improve the sustainable management of these forests, managers need adequate information and models regarding not only existing forest conditions, but their future states with varying alternative silvicultural activities. In this study, an individual-tree diameter growth model was developed for the full geographical distribution of the RORACO forest type. This was achieved by fitting a complete model by comparing two variable selection procedures: cross-validation (CV, and least absolute shrinkage and selection operator (LASSO regression. A small set of predictors successfully explained a large portion of the annual increment in diameter at breast height (DBH growth, particularly variables associated with competition at both the tree- and stand-level. Goodness-of-fit statistics for this final model showed an empirical coefficient of correlation (R2emp of 0.56, relative root mean square error of 44.49% and relative bias of −1.96% for annual DBH growth predictions, and R2emp of 0.98 and 0.97 for DBH projection at 6 and 12 years, respectively. This model constitutes a simple and useful tool to support management plans for these forest ecosystems.

Evaluation of the physical, mechanical and biological properties of the combined wood-plastic in Nothofagus Pumilio wood

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Benedetto Acuna, Andres

2010-01-01

In this project he studied the physical, mechanical and biological properties of wood-plastic combinations (WPC) in timber Nothofagus pumilio (Lenga) impregnated with the monomer methyl methacrylate (MMA), trying to get a hold and maximum penetration into the wood . It was used for impregnation method fills the cell (Bethell). To achieve the polymerization, the MMA once absorbed by the specimens under study are irradiated with gamma rays at a dose of 25 kGy, ensuring a high percentage of final polymerization, which fluctuated between 55.09% and 84.48%. The tests applied to the specimens were moisture content, dimensional stability, density, compression perpendicular to grain, compression parallel to grain to grain compression 'new' Janka hardness, shear parallel to grain, static bending and termites. In general, except for the static bending test, the WPC had an increase in their property, being the tests of hardness, density and water absorption which achieved higher profits, increasing their properties at 104%, 79% and 75% respectively compared to untreated specimens. From the economic viewpoint, the production of an inch Lenga timber has a cost of $ 19,805, so it may be feasible marketing both domestically and internationally (author)

Encapsulated Somatic Embryos and Zygotic Embryos for Obtaining Artificial Seeds of Rauli-Beech (Nothofagus alpina (Poepp. & Endl. Oerst. Encapsulado de Embriones Somáticos y Embriones Cigóticos para Obtención de Semillas Artificiales de Raulí (Nothofagus alpina (Poepp. & Endl. Oerst.

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Priscila Cartes R

2009-03-01

Full Text Available Somatic and zygotic embryos from mature seeds of rauli-beech, Nothofagus alpina (Poepp. & Endl. Oerst., were encapsulated in different artificial endosperms in order to generate a cover that fulfills the function of nourishment and protection of the embryos, facilitating their later germination. The content of sodium alginate varied by 4%, 3%, and 2%, as did the immersion time in calcium chloride (CaCl2, which acts as complexing agent. The artificial endosperm components of the Murashige and Skoog medium (MS were added, supplemented with 0.5 mg L-1 indolacetic acid (IAA, 0.5 mg L-1 naphthaleneacetic acid (NAA, 2 mg L-1 6-benzylaminopurine (BAP and 30 g L-1 sucrose. The germinative behaviors of encapsulated somatic and zygotic embryos were evaluated after 4 wk. Comparing the percentages of germination reached by encapsulated somatic and zygotic embryos it was observed that they had similar germinative behavior according to the type of encapsulation applied. However, zygotic embryos substantially exceeded the germination levels reached by somatic embryos, 100% vs. 45% respectively.Embriones somáticos y cigóticos provenientes de semillas maduras de raulí, Nothofagus alpina (Poepp. & Endl. Oerst., se encapsularon en diferentes endospermas sintéticos con el fin de generar una cubierta que cumpla la función de nutrir y proteger al embrión para facilitar su posterior germinación. Se varió el contenido de alginato de sodio al 4%, 3% y 2% y el tiempo de inmersión en cloruro de calcio (CaCl2, el que actúa como agente acomplejante. Además, a la matriz artificial se adicionaron componentes del medio Murashige y Skoog (MS suplementado con: 0,5 mg L-1 de indolacetic acid (IAA, 0,5 mg L-1 de ácido naftalenacético (NAA, 2 mg L-1 de 6-bencilaminopurina (BAP y 30 gL-1 de sacarosa. Al cabo de 4 semanas el porcentaje de germinación de los embriones somáticos y cigóticos encapsulados tuvieron similar comportamiento germinativo según el tipo de

Intraspecific trait variation and covariation in a widespread tree species (Nothofagus pumilio) in southern Chile.

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Fajardo, Alex; Piper, Frida I

2011-01-01

• The focus of the trait-based approach to study community ecology has mostly been on trait comparisons at the interspecific level. Here we quantified intraspecific variation and covariation of leaf mass per area (LMA) and wood density (WD) in monospecific forests of the widespread tree species Nothofagus pumilio to determine its magnitude and whether it is related to environmental conditions and ontogeny. We also discuss probable mechanisms controlling the trait variation found. • We collected leaf and stem woody tissues from 30-50 trees of different ages (ontogeny) from each of four populations at differing elevations (i.e. temperatures) and placed at each of three locations differing in soil moisture. • The total variation in LMA (coefficient of variation (CV) = 21.14%) was twice that of WD (CV = 10.52%). The total variation in traits was never less than 23% when compared with interspecific studies. Differences in elevation (temperature) for the most part explained variation in LMA, while differences in soil moisture and ontogeny explained the variation in WD. Traits covaried similarly in the altitudinal gradient only. • Functional traits of N. pumilio exhibited nonnegligible variation; LMA varied for the most part with temperature, while WD mostly varied with moisture and ontogeny. We demonstrate that environmental variation can cause important trait variation without species turnover. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Yeast and yeast-like fungi associated with dry indehiscent fruits of Nothofagus nervosa in Patagonia, Argentina.

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Fernández, Natalia V; Mestre, M Cecilia; Marchelli, Paula; Fontenla, Sonia B

2012-04-01

Nothofagus nervosa (Raulí) is a native tree species that yields valuable timber. It was overexploited in the past and is currently included in domestication and conservation programs. Several research programs have focused on the characterization of epiphytic microorganisms because it has been demonstrated that they can affect plant-pathogen interactions and/or promote plant growth. Although the microbial ecology of leaves has been well studied, less is known about microorganisms occurring on seeds and noncommercial fruits. In this work, we analyzed the yeast and yeast-like fungi present on N. nervosa fruits destined for the propagation of this species, as well as the effects of fruit preservation and seed dormancy-breaking processes on fungal diversity. Morphological and molecular methods were used, and differences between fungal communities were analyzed using a similarity index. A total of 171 isolates corresponding to 17 species were recovered, most of which belong to the phylum Ascomycota. The majority of the species develop mycelia, produce pigments and mycosporines, and these adaptation strategies are discussed. It was observed that the preservation process considerably reduced yeast and yeast-like fungal diversity. This is the first study concerning microbial communities associated with this ecologically and economically important species, and the information presented is relevant to domestication programs. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Agrobacterium rhizogenes vs auxinic induction for in vitro rhizogenesis of Prosopis chilensis and Nothofagus alpina.

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Caro, Luis A; Santecchia, Natalia; Marinangeli, Pablo A; Curvetto, Néstor R; Hernández, Luis F

2003-12-01

The induction and improvement of in vitro rhizogenesis of microshoots of Prosopis chilensis (Mol.) Stuntz and Nothofagus alpina (Poep. et Endl. Oerst.) were compared using Agrobacterium rhizogenes (Ar) versus indole-3-butyric acid (IBA) in the culture media. Microshoots of P. chilensis (1-2 cm length), coming from in vitro grown seedlings, were cultivated in a modified Broadleaved Tree Medium (BTMm) containing half salt concentration of macronutrients and 0.05 mg x L(-1) benzilaminopurine (BAP). After 30 days, microshoots with 2-4 leaves were selected and cultured in BTMm-agar in presence or abscense of Ar and in combination with IBA. For N. alpina, the apical shoots with the first 2 true leaves, from 5 weeks old seedlings, were cultured in the abovementioned medium, but with 0.15 mg x L(-1) of BAP. After 2 months, microshoots with 2-3 leaves were selected and cultured in BTMm-agar, supplemented with 5 mg x L(-1) IBA or in liquid BTMm on perlite and, in the presence or absence of A. rhizogenes (Ar) and in combination with 3 mg x L(-1) IBA. Rooting in P. chilensis reached 100.0% when Ar infection was produced in the presence of IBA, increasing both, the number and dry weight of roots. In N. alpina, 90.0% of rooting efficiency was obtained when Ar infection was produced in liquid culture and in the absence of auxin.

Effect of ectomycorrhizal colonization and drought on reactive oxygen species metabolism of Nothofagus dombeyi roots.

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Alvarez, Maricel; Huygens, Dries; Fernandez, Carlos; Gacitúa, Yessy; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Infection with ectomycorrhizal fungi can increase the ability of plants to resist drought stress through morphophysiological and biochemical mechanisms. However, the metabolism of antioxidative enzyme activities in the ectomycorrhizal symbiosis remains poorly understood. This study investigated biomass production, reactive oxygen metabolism (hydrogen peroxide and malondialdehyde concentration) and antioxidant enzyme activity (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in pure cultures of the ectomycorrhizal fungi Descolea antartica Sing. and Pisolithus tinctorius (Pers.) Coker & Couch, and non-mycorrhizal and mycorrhizal roots of Nothofagus dombeyi (Mirb.) roots under well-watered conditions and drought conditions (DC). The studied ectomycorrhizal fungi regulated their antioxidative enzyme metabolism differentially in response to drought, resulting in cellular damage in D. antartica but not in P. tinctorius. Ectomycorrhizal inoculation and water treatment had a significant effect on all parameters studied, including relative water content of the plant. As such, N. dombeyi plants in symbiosis experienced a lower oxidative stress effect than non-mycorrhizal plants under DC. Additionally, ectomycorrhizal N. dombeyi roots showed a greater antioxidant enzyme activity relative to non-mycorrhizal roots, an effect which was further expressed under DC. The association between the non-specific P. tinctorius and N. dombeyi had a more effective reactive oxygen species (ROS) metabolism than the specific D. antartica-N. dombeyi symbiosis. We conclude that the combination of effective ROS prevention and ROS detoxification by ectomycorrhizal plants resulted in reduced cellular damage and increased plant growth relative to non-mycorrhizal plants under drought.

Estudio comparativo del crecimiento y la ramificación de brotes anuales en dos especies de Nothofagus (Nothofagaceae y en híbridos inter-específicos Comparative study of annual shoot growth and branching in two species of Nothofagus (Nothofagaceae and inter-specific hybrids

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Cristian Torres

2009-12-01

Full Text Available Las ramas principales y secundarias se diferencian en mayor o menor medida según las especies, lo cual puede observarse en base al crecimiento primario de los brotes que las originan. En ejemplares de vivero juveniles-adultos de Nothofagus obliqua, N. nervosa e híbridos entre ambas especies, se compararon la dinámica de alargamiento, el tamaño y la morfología de dos brotes distales de ramas principales: uno que continúa el alargamiento de la rama principal y el otro que inicia una rama secundaria. En N. alpina y en híbridos, los dos brotes más distales se diferencian más que en N. obliqua. A pesar de la homogeneidad ambiental en el vivero y el origen geográfico común para los ejemplares de N. nervosa y los híbridos, hubieron diferencias fenológicas y morfológicas entre estas entidades. La duración y tasa de alargamiento y la longitud final de los brotes fueron altamente variables en cada entidad. Las variaciones entre entidades en la diferenciación de ejes podrían indicar diferencias en sus capacidades de uso del espacio circundante. La diferenciación entre ramas principales y secundarias se iniciaría en el estado de yema. La variación intra-específica fenológica y morfológica es útil para programas de selección artificial de individuos.Main and secondary branches are more or less differentiated according to the species and this could be observed during the primary growth of the shoots that produce them. In young-adult trees of Nothofagus obliqua, N. nervosa and hybrids between them growing in a common garden, growth dynamics, size and morphology were compared between two distal shoots produced by main branches: one of these shoots continued the extension of the main branch whereas the other initiated a secondary branch. The two distal shoots differed from each other more notably in N. nervosa and in the hybrids than in N. obliqua. Despite the environmental homogeneities at the nursery and the common geographic origin of

Variación estacional y potencial enzimático de microhongos asociados con la descomposición de hojarasca de Nothofagus pumilio Seasonal variation and enzymatic potential of microfungi associated with the decomposition of Nothofagus pumilio leaf litter

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EDUARDO VALENZUELA

2001-12-01

Full Text Available Se estudió la variación estacional y el potencial enzimático de microhongos aislados desde el follaje y hojarasca de Nothofagus pumilio sometida a degradación natural durante 1 año. La investigación se realizó en un bosque de N. pumilio ubicado en una microcuenca del Valle de Antillanca, Parque Nacional Puyehue (40° 47' S, 72° 12' O, 1.120 m de altitud. Hojas senescentes colectadas desde árboles de N. pumilio se depositaron en bolsas de malla de nylon ("litter bags" y se sometieron a degradación natural en el piso del bosque durante 1 año (marzo 1997-marzo 1998, realizando muestreos trimestrales. Para el aislamiento de microhongos desde las hojas se utilizó el método de las diluciones, con agar extracto de malta al 2 % como medio de cultivo. Para determinar los potenciales degradativos de los aislamientos, se analizaron in vitro las actividades de amilasa, celulasa, pectinasa, proteasa, lacasa, oxidasa extracelular, peroxidasa, citocromo oxidasa, fosfatasa, esterasa y tirosinasa. Las principales especies aisladas en las hojas senescentes fueron Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Phialophora grupo hoffmannii y Rhodotorula aurantiaca. Las especies dominantes en la hojarasca fueron Hormonema prunorum, Mortierella ramanniana var. angulispora, Penicillium para-herquei y Trichoderma polysporum. El mayor potencial enzimático lo exhibieron Moniliales y micelios estériles, mientras el menor Sphaeropsidales y levaduras. Las especies más activas fueron Alternaria alternata, Cladosporium cladosporioides, Hormonema prunorum y Phialophora malorum. Las actividades de celulasa y amilasa fueron las más importantes. De las enzimas ligninolíticas, oxidasa extracelular y peroxidasa presentaron los más elevados potenciales enzimáticosThe seasonal variation and enzymatic potential of microfungi isolated from senescent leaves and leaf litter of Nothofagus pumilio was studied. The study was performed in a N

Site quality influence over understory plant diversity in old-growth and harvested Nothofagus pumilio forests

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E. A. Gallo

2013-04-01

Full Text Available Aim of study: The effects and interactions of shelterwood forest harvesting and site qualities over understory plant species diversity and composition were compared among primary and harvested Nothofagus pumilio forests.Area of study: Tierra del Fuego (Argentina, on three pure conditions (one and six year-old harvested, and primary without previous harvesting forests and three site qualities (high, medium and low.Material and Methods: Understory richness and cover (% were registered in five replicates of 1 hectare each per treatment. Taxonomic species were classified in categories (groups, origin and life forms. Two-way ANOVAs and multivariate analyses were conducted.Main results: Shelterwood harvesting and site quality significantly influenced understory cover and richness, which allow the introduction of native and exotic species and increasing of dicot and monocot covers. In dicots, monocots, exotics and total groups, higher richness and covers were related to time. Meanwhile, cover reached similar high values in all site qualities on dicot, native and total groups. On the other hand, monocot and exotic richness and cover remain similar in primary and recently harvested forests, and greatly increased in old harvested forests. Mosses and ferns were among the most sensitive groups.Research highlights: Impacts of shelterwood cut depend on site quality of the stands and time since harvesting occurs. For this, different site quality stands should received differential attention in the development of conservation strategies, as well as variations in the shelterwood implementation (as irregularity and patchiness should be considered to better promote understory plant species conservation inside managed areas.Key words: plant species conservation; years after harvesting; forest management; Tierra del Fuego.

Are trait-scaling relationships invariant across contrasting elevations in the widely distributed treeline species Nothofagus pumilio?

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Fajardo, Alex

2016-05-01

The study of scaling examines the relative dimensions of diverse organismal traits. Understanding whether global scaling patterns are paralleled within species is key to identify causal factors of universal scaling. I examined whether the foliage-stem (Corner's rules), the leaf size-number, and the leaf mass-leaf area scaling relationships remained invariant and isometric with elevation in a wide-distributed treeline species in the southern Chilean Andes. Mean leaf area, leaf mass, leafing intensity, and twig cross-sectional area were determined for 1-2 twigs of 8-15 Nothofagus pumilio individuals across four elevations (including treeline elevation) and four locations (from central Chile at 36°S to Tierra del Fuego at 54°S). Mixed effects models were fitted to test whether the interaction term between traits and elevation was nonsignificant (invariant). The leaf-twig cross-sectional area and the leaf mass-leaf area scaling relationships were isometric (slope = 1) and remained invariant with elevation, whereas the leaf size-number (i.e., leafing intensity) scaling was allometric (slope ≠ -1) and showed no variation with elevation. Leaf area and leaf number were consistently negatively correlated across elevation. The scaling relationships examined in the current study parallel those seen across species. It is plausible that the explanation of intraspecific scaling relationships, as trait combinations favored by natural selection, is the same as those invoked to explain across species patterns. Thus, it is very likely that the global interspecific Corner's rules and other leaf-leaf scaling relationships emerge as the aggregate of largely parallel intraspecific patterns. © 2016 Botanical Society of America.

Aplicación de relaciones de densidad-diámetro y de área potencial aprovechable en bosques de Nothofagus Dombeyi (mirb.) Oerst, como herramientas de planificación silvícola .

OpenAIRE

Cruz Johnson, Pablo Christian

2013-01-01

Uno de los objetivos de esta tesis de doctorado fue analizar la aplicación de relaciones de densidad ¿ diámetro en bosques de Nothofagus dombeyi (Mirb.) oerst, para la localidad del Río Mirta en la XI Región de Chile, como herramientas de planificación silvícola. El método de análisis consistió en la generación de una muestra de densidad¿diámetro a partir de la que se determinó el índice de densidad máximo (IDmax) a partir del cual se estimaron las máximas densidades que la especie podría alc...

Estructura del quiste hidatídico producido por Echinococcus oligarthrus en el hospedero intermediario Proechimys c.f. guairae (rata espinosa en Casanare, Colombia

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Gerzain Rodríguez

2000-09-01

Full Text Available La equinococosis es un parasitismo grave producido en el hombre y en los animales por larvas de tenias del género Echinococcus que se desarrollan en el higado, el pulmón, el bazo y en otras visceras y tejidos. De las cuatro tenias dei género Echinococcus, tres se presentan en Suramerica: E granulosus, E. vogeli y E. oligarihrus. En Colombia se han informado casos en humanos y en animales cuyo agente etiológico más frecuente es E. vogeli. En este trabajo presentamos la estructura macroscópica, microscópica y de microscopia electrónica de barrido de quistes hidatídicos múltiples y de sus protoescólices encontrados en un Proechimys c.f guairae o rata espinosa, capturado en la vereda La Plata del municipio de Pore, Casanare, durante la búsqueda de reservorios del virus de la encefalitis equina venezolana. En la autopsia del animal se encontraron quistes múltiples en el higado, el bazo y el pulmón, la gran mayoría fértiles. Están constituidos por una pared franjeada que origina cápsulas proligeras dentro de las cuales están los protoescólices. El protoescólex es el escólex inmaduro del parásito adulto formado por cuatro ventosas y un rostelo con ganchos, cuyo tamaño y morfologia corresponden con las medidas de E. oligaiihrus. Ilustramos las caracteristicas morfológicas de las larvas, el desarrollo de los protoescólices y revisamos las caracteristicas de la equinococosis en Colombia.

Ectomycorrhizal fungi enhance nitrogen and phosphorus nutrition of Nothofagus dombeyi under drought conditions by regulating assimilative enzyme activities.

Science.gov (United States)

Alvarez, Maricel; Huygens, Dries; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Drought stress conditions (DC) reduce plant growth and nutrition, restraining the sustainable reestablishment of Nothofagus dombeyi in temperate south Chilean forest ecosystems. Ectomycorrhizal symbioses have been documented to enhance plant nitrogen (N) and phosphorus (P) uptake under drought, but the regulation of involved assimilative enzymes remains unclear. We studied 1-year-old N. dombeyi (Mirb.) Oerst. plants in association with the ectomycorrhizal fungi Pisolithus tinctorius (Pers.) Coker & Couch. and Descolea antartica Sing. In greenhouse experiments, shoot and root dry weights, mycorrhizal colonization, foliar N and P concentrations, and root enzyme activities [glutamate synthase (glutamine oxoglutarate aminotransferase (GOGAT), EC 1.4.1.13-14), glutamine synthetase (GS, EC 6.3.1.2), glutamate dehydrogenase (GDH, EC 1.4.1.2-4), nitrate reductase (NR, EC 1.6.6.1), and acid phosphomonoesterase (PME, EC 3.1.3.1-2)] were determined as a function of soil-water content. Inoculation of N. dombeyi with P. tinctorius and D. antartica significantly stimulated plant growth and increased plant foliar N and P concentrations, especially under DC. Ectomycorrhizal inoculation increased the activity of all studied enzymes relative to non-mycorrhizal plants under drought. We speculate that GDH is a key enzyme involved in the enhancement of ectomycorrhizal carbon (C) availability by fuelling the tricarboxylic acid (TCA) cycle under conditions of drought-induced carbon deficit. All studied assimilative enzymes of the ectomycorrhizal associations, involved in C, N, and P transfers, are closely interlinked and interdependent. The up-regulation of assimilative enzyme activities by ectomycorrhizal fungal root colonizers acts as a functional mechanism to increase seedling endurance to drought. We insist upon incorporating ectomycorrhizal inoculation in existing Chilean afforestation programs.

Responses of two températe evergreen Nothofagus species to sudden and gradual waterlogging: relationships with distribution patterns Respuestas de dos especies siempreverdes de Nothofagus al anegamiento gradual y repentino: relaciones con patrones de distribución

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FRIDA PIPER

2008-06-01

Full Text Available The effects of gradual waterlogging on trees have been little studied. The températe evergreens Nothofagus nítida and N. dombeyi are differentially distributed on soil moisture gradients, only the former being common on poorly-drained sites. We compared the relative height growth rate (RGR H and foliage loss of seedlings subjected experimentally to normal drainage (soil at field capacity, sudden waterlogging and gradual waterlogging for two months to determine which waterlogging regime more accurately predicts interspecific differences in tolerance, as evident from natural distributions. RGR H was similar between species but differed between treatments (normal watering > gradual waterlogging = sudden waterlogging. Sudden waterlogging caused massive foliage loss in the two species, but gradual waterlogging caused much greater foliage loss in N. dombeyi than in N. nítida, indicating some degree of acclimation by the latter species. Linear regressions indicated that RGR H was negatively affected by foliage loss in both species, without differences between them. Since no difference in RGR H was found between species in the waterlogging treatments, but yet in foliage loss, other mechanisms may be in volved in the short term growth reduction of N. nítida. Effects of waterlogging on long-term performance in the field were evaluated by reciprocal transplants between a poorly-drained site naturally occupied by N. nítida, and a well drained site naturally occupied by N. dombeyi. After two growing seasons, N. dombeyi had significantly lower specific leaf área (SLA and RGR H, at the poorly drained site than at its original site. At the poorly drained site N. nítida achieved 100 % survival, compared with 73.5 % in N. dombeyi. Reduced growth and survival of N. dombeyi associated with the negative effects on carbón gain of extensive foliage loss and reduced SLA may thus exelude it from the wetter sites. We conclude that tolerance may be better

Estimación del índice de sitio en rodales de Nothofagus dombeyi a través de herramientas de teledetección espacial

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C. Esse

2013-12-01

Full Text Available La estimación del índice de sitio y la calidad del sitio constituyen herramientas básicas en la gestión de los ecosistemas forestales y la práctica de la silvicultura. El estudio de la distribución espacial y la dinámica temporal de índice de sitio y la calidad del sitio de los ecosistemas forestales aún carece de los avances tecnológicos. Este estudio propone la integración de las herramientas de teledetección para la estimación de la productividad forestal para áreas remotas. Se evaluó el potencial de aplicación de la metodología en amplias regiones y los bosques con la evaluación de la exactitud. Los resultados muestran que el índice del sitio de los bosques secundarios de Nothofagus dombeyi (Mirb. Oerst., están en correlación lineal con los índices de vegetación normalizada (NDVI, índice de diferencia de vegetación ajustado (TNDVI, banda Infrarroja pura de la imagen y transformación de componentes principales. Este estudio demostró que este enfoque puede ser utilizado en la estimación de la productividad de bosques secundarios en diferentes ecosistemas forestales.

Endogenous Quantification of Abscisic Acid and Indole-3-Acetic Acid in Somatic and Zigotic Embryos of Nothofagus alpina (Poepp. & Endl. Oerst Cuantificación Endógena de Ácido Abscísico y Ácido Indol-3 Acético en Embriones Somáticos y Cigóticos de Nothofagus alpina (Poepp. & Endl. Oerst

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Pricila Cartes Riquelme

2011-12-01

Full Text Available Abscisic acid (ABA and indole-3-acetic acid (IAA participate in the propagation of plants by somatic embryogenesis, causing polar structural differentiation of the embryo. The goal of the assay was to compare endogenous levels of ABA and IAA between somatic embryos (SE and zygotic embryos (ZE of Nothofagus alpina (Poepp. & Endl. Oerst. In this study, a somatic embryo maturation assay involving the addition of varying concentrations of exogenous ABA was performed on cotyledonary-stage of N. alpina. Furthermore, the endogenous levels of ABA and IAA were quantified in the immature ZE, the mature ZE, and the embryonic axis of a mature embryo of N. alpina. The current study utilized high performance liquid chromatography (HPLC for quantification. The maturation treatments performed did not present significant differences in the endogenous ABA levels in SE. However, significant differences did exist in levels of ABA and IAA between SE submitted to the different maturation treatments and mature ZE of N. alpina. The application of exogenous ABA to the culture medium increased endogenous ABA levels, therefore, increasing the number of germinated somatic embryos. Thus, the plant conversion process was also successfully completed in somatic embryos of N. alpina.El ácido abscísico (ABA y el ácido indol 3 acético (IAA participan en el proceso de propagación de plantas mediante embriogénesis somática, ya que permiten la diferenciación de la estructura polar del embrión, órganos y regiones meristemáticas de éste. En este estudio se llevó a cabo un ensayo de maduración de embriones somáticos en estado cotiledonar con la adición de diferentes concentraciones de ABA exógeno, además se determinaron niveles endógenos entre ZE inmaduro, ZE maduro, y eje embrionario aislado desde el embrión maduro para luego comparar niveles endógenos de ABA e IAA en embriones somáticos (SE y cigóticos (ZE de raulí, Nothofagus alpina (Poepp. & Endl. Oerst. La

Plant effects on soil carbon storage and turnover in montane beech (Nothofagus) forest and adjacent tussock grassland in New Zealand

International Nuclear Information System (INIS)

Tate, K.R.; Scott, N.A.; Ross, D.J.; Parshotam, A.; Claydon, J.J.

2000-01-01

Land cover is a critical factor that influences, and is influenced by, atmospheric chemistry and potential climate changes. As considerable uncertainty exists about the effects of differences in land cover on below-ground carbon (C) storage, we have compared soil C contents and turnover at adjacent, unmanaged, indigenous forest (Nothofagus solandri var. cliffortiodes) and grassland (Chionochloa pallens) sites near the timberline in the same climo-edaphic environment in Craigieburn Forest Park, Canterbury, New Zealand. Total soil profile C was 13% higher in the grassland than in the forest ( 19.9 v. 16.7 kg/m 2 ), and based on bomb 14 C measurements, the differences mainly resulted from more recalcitrant soil C in the grassland (5.3 v. 3.0 kg/m 2 ). Estimated annual net primary production was about 0.4 kg C/m 2 for the forest and 0.5 kg C/m 2 for the grassland; estimated annual root production was about 0.2 and 0.4 kg C/m 2 , respectively. In situ soil surface CO 2 -C production was similar in the grassland and the forest. The accumulation of recalcitrant soil C was unrelated to differences in mineral weathering or soil texture, but was apparently enhanced by greater soil water retention in the grassland ecosystem. Thus, contrary to model (ROTHC) predictions, this soil C fraction could be expected to respond to the effects of climate change on precipitation patterns. Overall, our results suggest that the different patterns of soil C accumulation in these ecosystems have resulted from differences in plant C inputs, soil aluminium, and soil physical characteristics, rather than from differences in soil mineral weathering or texture. Copyright (2000) CSIRO Australia

Establishment of ectomycorrhizal fungal community on isolated Nothofagus cunninghamii seedlings regenerating on dead wood in Australian wet temperate forests: does fruit-body type matter?

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Tedersoo, Leho; Gates, Genevieve; Dunk, Chris W; Lebel, Teresa; May, Tom W; Kõljalg, Urmas; Jairus, Teele

2009-08-01

Decaying wood provides an important habitat for animals and forms a seed bed for many shade-intolerant, small-seeded plants, particularly Nothofagus. Using morphotyping and rDNA sequence analysis, we compared the ectomycorrhizal fungal community of isolated N. cunninghamii seedlings regenerating in decayed wood against that of mature tree roots in the forest floor soil. The /cortinarius, /russula-lactarius, and /laccaria were the most species-rich and abundant lineages in forest floor soil in Australian sites at Yarra, Victoria and Warra, Tasmania. On root tips of seedlings in dead wood, a subset of the forest floor taxa were prevalent among them species of /laccaria, /tomentella-thelephora, and /descolea, but other forest floor dominants were rare. Statistical analyses suggested that the fungal community differs between forest floor soil and dead wood at the level of both species and phylogenetic lineage. The fungal species colonizing isolated seedlings on decayed wood in austral forests were taxonomically dissimilar to the species dominating in similar habitats in Europe. We conclude that formation of a resupinate fruit body type on the underside of decayed wood is not necessarily related to preferential root colonization in decayed wood. Rather, biogeographic factors as well as differential dispersal and competitive abilities of fungal taxa are likely to play a key role in structuring the ectomycorrhizal fungal community on isolated seedlings in decaying wood.

Influencias de las variaciones en el clima y en la concentración de C0(2 sobre el crecimiento de Nothofagus pumilio en la Patagonia Influences of climatic and C0(2 concentration changes on radial growth oí Nothofagus pumilio in Patagonia

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ANA M SRUR

2008-06-01

Full Text Available El objetivo de este trabajo fue evaluar las relaciones entre las variaciones en el clima y en la concentración de C0(2 durante el siglo XX con el crecimiento radial y la eficiencia en el uso del agua en los bosques de Nothofagus pumilio a lo largo de un gradiente altitudinal, en El Chaltén (49°22' S, Santa Cruz, Argentina. Se empleó una combinación de técnicas dendrocronológicas e isotópicas. Los patrones de crecimiento radial a lo largo del gradiente altitudinal reflejan las tendencias climáticas registradas en la zona durante el siglo XX. El crecimiento de los árboles ubicados en el límite superior muestra una tendencia positiva en respuesta al incremento regional de las temperaturas. Por el contrario, los bosques en contacto con la estepa patagónica presentan, en respuesta a una intensificación del déficit hídrico, una tendencia negativa de crecimiento durante el siglo pasado. Los árboles creciendo en bosques mésicos ubicados en alturas intermedias muestran una tendencia levemente negativa no significativa. Los valores de 6(13C reflejan en qué medida el contenido de humedad en el suelo regula en forma diferencial los procesos de conductancia estomática y tasa fotosintética a lo largo del gradiente altitudinal. En sitios donde el déficit hídrico varía desde leve a muy marcado, la eficiencia intrínseca en el uso del agua (EIUA parece estar influenciada por la disponibilidad de agua en el suelo. La relación entre la EIUA y las variables climáticas es más clara en sitios con reducido estrés hídrico. En sitios secos, el estrés hídrico muy marcado reduciría la tasa fotosintética en grado tal que el crecimiento no podría ser compensado por el aumento en EIUA. En contraste con el concepto tradicional en dendrocronología que postula una relación más estrecha entre el crecimiento radial y las variaciones climáticas en los bosques ecotonales, los valores isotópicos de 6(13C representan más claramente las

Effect of wildfire on soil physical and chemical properties in a Nothofagus glauca forest, Chile Efecto del fuego en las propiedades físicas y químicas en un bosque de Nothofagus glauca en Chile

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CREIGHTON M. LITTON

2003-12-01

Full Text Available Effects of a wildfire on soil chemical and physical properties in a Nothofagus glauca (Phil. Krasser forest in the Coastal Mountain Range of south-central Chile were investigated. Response of the soil during the first two years following a wildfire was examined, where data from soil in a burned forest were compared to that in an adjacent, unburned stand. The effects that wildfire have on soil properties in this highly fragmented ecosystem are not well understood, but results from this study suggest similar responses to those found in other mediterranean forest systems. Both physical (bulk density, percent soil moisture, and soil organic matter content and chemical properties (exchangeable inorganic nitrogen, extractable phosphorus, exchangeable potassium, and soil pH were examined, and data presented here suggest that soil properties vary in their initial response to fire in this ecosystem. Soil organic matter content and soil moisture decreased following fire and remained lower than values from unburned plots for the duration of the study. Exchangeable potassium increased initially after burning, but values in burned plots decreased with time and by the end of two years were significantly lower than in unburned soil. In turn, extractable phosphorus and soil pH both increased immediately following wildfire and values in burned plots remained significantly higher than unburned plots for the entire measurement period. Exchangeable inorganic nitrogen reached higher levels in soil of burned plots for the autumn measurements (April 1997 and 1998 and lower values in burned plots for the spring measurements (November 1997 and 1998. Soil bulk density remained unchanged following fire. In general, changes in soil properties following fire were greatest at the 0-5 cm layer and more modest at the 5-10 cm sampling depth. These changes were related primarily to oxidation of the detrital layer during fire and concurrent changes in the soil environment

Living on the edge: adaptive and plastic responses of the tree Nothofagus pumilio to a long-term transplant experiment predict rear-edge upward expansion.

Science.gov (United States)

Mathiasen, Paula; Premoli, Andrea C

2016-06-01

Current climate change affects the competitive ability and reproductive success of many species, leading to local extinctions, adjustment to novel local conditions by phenotypic plasticity or rapid adaptation, or tracking their optima through range shifts. However, many species have limited ability to expand to suitable areas. Altitudinal gradients, with abrupt changes in abiotic conditions over short distances, represent "natural experiments" for the evaluation of ecological and evolutionary responses under scenarios of climate change. Nothofagus pumilio is the tree species which dominates as pure stands the montane forests of Patagonia. We evaluated the adaptive value of variation in quantitative traits of N. pumilio under contrasting conditions of the altitudinal gradient with a long-term reciprocal transplant experimental design. While high-elevation plants show little response in plant, leaf, and phenological traits to the experimental trials, low-elevation ones show greater plasticity in their responses to changing environments, particularly at high elevation. Our results suggest a relatively reduced potential for evolutionary adaptation of high-elevation genotypes, and a greater evolutionary potential of low-elevation ones. Under global warming scenarios of forest upslope migration, high-elevation variants may be outperformed by low-elevation ones during this process, leading to the local extinction and/or replacement of these genotypes. These results challenge previous models and predictions expected under global warming for altitudinal gradients, on which the leading edge is considered to be the upper treeline forests.

Teledetección satelital cuantitativa para estimar el área basal del bosque de Nothofagus pumilio (Nothofagaceae: El rol del índice de área foliar como información auxiliar Quantitative remote sensing to estimate basal area in Nothofagus pumilio (Nothofagaceae forest: The role of leaf area index as ancillary information

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GASTÓN M DÍAZ

2011-12-01

Full Text Available Los bosques de lenga (Nothofagus pumilio son el recurso forestal más importante de la región andino patagónica argentina, sin embargo, para implementar planes de manejo en pos de prevenir o revertir su degradación es necesario disponer de mayor información sobre su estructura. Una alternativa para obtener esa información es relacionar datos satelitales con las características del bosque a través de modelos físicos y estadísticos. Pero, ¿cuál es el método más eficaz? El índice de área foliar (IAF se encuentra relacionado con la reflectividad del dosel vegetal a través del modelo de transferencia radiativa PROSAIL, lo que permite desarrollar técnicas de teledetección satelital para estimar el IAF con bases físicas, en vez de con modelos estadísticos. De ese modo se puede aprovechar la relación empírico-biológica existente entre el IAF y la estructura del bosque para estimar el área basal. El objetivo principal fue comparar la exactitud de tres métodos para estimar el área basal de la lenga con datos SPOT-5. Los métodos comparados fueron: estadístico directo (ED, estadístico de dos pasos (E2P y físico-estadístico de dos pasos (FE2P. La exactitud fue evaluada con 24 parcelas no involucradas en el ajuste o calibración de los modelos. No se hallaron diferencias significativas en la exactitud de la alternativa físico-estadística en comparación con las netamente estadísticas. Sin embargo, en base al análisis conjunto de los resultados y lo reportado por otros investigadores, se concluye que la ventaja de utilizar modelos físicos radica en la mayor robustez de la estimación y no en la mayor exactitud.Lenga forests (Nothofagus pumilio are the most important forest resource of the Argentinean Andean Patagonia, however, more information about their structure is needed to implement forest management policies and practices in order to prevent their degradation and revert it. One option to obtain this kind of information

Imprints of climate signals in a 204 year 18O tree-ring record of Nothofagus pumilio from Perito Moreno Glacier, southern Patagonia (50°S).

Science.gov (United States)

Grießinger, Jussi; Langhamer, Lukas; Schneider, Christoph; Saß, Björn-Lukas; Steger, David; Skvarca, Pedro; Braun, Matthias H.; Meier, Wolfgang J.-H.; Srur, Ana M.; Hochreuther, Philipp

2018-04-01

A 204 year-long record of 18O in tree-ring cellulose of southern beech (Nothofagus pumilio) from a site near Perito Moreno Glacier (50°S) in southern Patagonia was established to assess its potential for a climate reconstruction. The annually resolved oxygen isotope chronology is built out of seven individual tree-ring 18O series with a significant mean inter-series correlation (r = 0.61) and is the first of its kind located in Southern America south of 50°S. Over a common period from 1960 to 2013 of available stationary and high-resolution gridded CRU TS v. 4.01 data, the 18O chronology exhibits a strong sensitivity towards hydroclimatic as well as temperature parameters as revealed by correlation analyses. Among these, positive correlations with maximum temperature in the first part of the summer season (CRU rONDJ = 0.51, pAmerica. The modulation of positive and negative anomalies within this series can be interlinked to changes in moisture source origin as revealed by backward trajectory modeling. Additionally, these anomalies can be directly associated to positive or negative phases of the Antarctic Oscillation Index (AAOI) and therefore the strength of the Westerlies. Aligned by the analysis on the influence of different main weather types on the 18O chronology it is shown that such time-series hold the potential to additionally capture their respective influence and change during the last centuries.

Histología y ultraestructura del sistema reproductor masculino de la langosta espinosa de la India Panulirus homarus (Decapoda: Palinuridae

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S Lakshmi Pillai

2014-08-01

Full Text Available La langosta espinosa Panulirus homarus, distribuida a lo largo de las costas sudeste y sudoeste de la India, es una especie de importancia comercial con gran potencial para la mari-cultura. A pesar de su importancia, las características estructurales y ultraestructurales de las gónadas masculinas de esta especie han sido poco estudiadas. Debido a esto, el objetivo de este estudio fue describir el aparato reproductor masculino de dicha especie, utilizando técnicas convencionales de microscopía histológica y electrónica. Se procesaron 94 ejemplares de P. homarus de vizhinjam (costa suroeste de la India (70 individuos para histología y 24 para ultraestructura, cuyos caparazones variaron de 37 mm a 92 mm de longitud. El sistema reproductor masculino de esta especie consistió en un par de testículos y un conducto deferente situados en la región céfalo-torácica. Macroscópicamente, el aparato reproductor se observó en langostas con una longitud de caparazón >35mm. En testículos inmaduros, la espermatogonia midió 6.9-13.8μm de diámetro y se encontró presente en los testículos maduros primarios (5.4-5.9μm, espermatocitos secundarios (2.8 a 3 μm y espermátidas (2.2-2.4μm. Cada conducto deferente consistió de porciones proximales y distales. La formación de la masa espermatofórica comienza en los conductos deferentes proximales. En el conducto deferente distal espermatofórico, la masa que contiene los espermatozoides está dispuesta en paquetes hacia la periferia, en una matriz gelatinosa producida por el tiflosol. Ultraestructuralmente, las espermatogonias presentan una lámina, núcleo y mitocondrias, los espermatocitos primarios tienen núcleo, cromatina densa y citoplasma vacuolado, mientras que las espermátidas tienen mitocondrias, retículo endoplasmático y centríolos. En las espermátidas, el retículo endoplásmico y la envoltura nuclear forman el acrosoma. Los brazos radiales con microtúbulos se forman en asociaci

Sapling growth and crown expansion in canopy gaps of Nothofagus pumilio (lenga) forests in Chubut, Patagonia, Argentina

Energy Technology Data Exchange (ETDEWEB)

Lopez Bernal, P. M.; Defosse, G. E.; Quinteros, C. P.; Bava, J. O.

2012-07-01

In the province of Chubut in Patagonia, Argentina, Nothofagus pumilio forests (locally known as lenga), are managed through selective cuts, which imply the opening of canopy gaps. This management scheme is carried out without taking into consideration the changes of sapling requirements through either a cutting cycle or the precipitation gradient in which these forests thrive. To analyze these changes, we inferred the facilitation-competition balance between the canopy and regeneration, studying the effects of precipitation levels, gap size and gap age on saplings growth in height on 45 canopy gaps artificially created between 1960 and 1993. Results showed that during the first 20 years since gap opening, growth of regeneration is determined by light availability in mesic sites and by water availability in xeric sites. However, differences due to precipitation levels gradually decrease over time. Moreover, in the period between 20 and 35 years after gap opening, in both mesic and xeric sites, growth is limited by light availability. This indicates that in xeric sites, sapling growth requirements shift from a water-dependent situation to a light-dependent situation. The average closing rate of gaps due to lateral growth of bordering trees is high enough so that within the proposed gap size range, gap healing can occur before regeneration reaches the upper stratum. Consequently, in mesic sites gap opening can be done by a single operation that generates gaps with diameters of approximately twice the average height of the canopy (D/H). While in xeric environments, lenga seedling establishment and initial growth require the cover of small gaps, but advanced regeneration requires bigger gaps to reach the canopy. For this reason, gaps should be opened in two stages: the first gaps should be opened with a D/H between 0.8 and 1, and after a cutting cycle of 35 years, these openings should be enlarged to a D/H between 1.5 and 2. The close relationship maintained between the

Cuba in Transition: Communism vs Charisma Who Will Emerge as Cuba’s Next Leader

Science.gov (United States)

2001-04-04

38 Olivo Verde, Defense of the Socialist Homeland, 6 March 1986. 26 MajGen Frias LtGen Espinosa MajGen Sola Cuban forces.39 The FAR is...comprised of three separate branches: the Army (Ejercito 150,000 troops strong), the Navy [Marina de Guerra Revolucionaria (MG) 5,000 troops strong] and...Cintro Frias , and is headquartered in Havana. The Eastern Army Corps, is led by General Ramon Espinosa Martin, and is headquartered in Santiago de Cuba

Unraveling the Nature of Chemical Reactivity of Complex Systems

Science.gov (United States)

2009-01-13

28 J. Zhou, J. J. Lin, W. Shiu, and K. Liu, J. Chem. Phys. 119, 4997 2003. 29 S. C. Althorpe, F. Fernandez - Alonso , B. D. Bean, J. D. Ayers, A. E...Truhlar DG, Espinosa- Garcia J (2000) Potential energy surface, thermal, and state-selected rate coefficients, and kinetic isotope effects for Cl CH43...HCl CH3. J Chem Phys 112:9375–9389. 22. Rangel C, Navarrete M, Corchado JC, Espinosa- Garcia J (2006) Potential energy surface, kinetics, and

Mineralización del nitrógeno, carbono y actividad enzimática del suelo en un bosque de Nothofagus obliqua (Mirb Oerst y una plantación de Pinus radiata D. Don. del centro-sur de Chile Nitrogen and carbon mineralization and enzyme activity in soils of Nothofagus obliqua (Mirb Oerst stands and Pinus radiata D. Don plantation in south-central Chile

Directory of Open Access Journals (Sweden)

YESSICA RIVAS

2009-03-01

Full Text Available En Chile, el establecimiento de plantaciones comerciales de rápido crecimiento ha sido sostenido en las últimas décadas mediante la sustitución de bosques nativos y conversión de suelos agrícolas. Pinus radiata D. Don es la principal especie productiva, debido a su crecimiento acelerado y adaptabilidad al clima y los suelos. En el presente estudio se plantea que la actividad biológica del suelo es variable a través del año, en respuesta a variaciones de precipitación, temperatura y contenido de humedad de suelo y que el cambio de uso de suelo desde un bosque templado de Nothofagus obliqua (Mirb Oerst a una plantación con coniferas exóticas, modifica la química del suelo y consecuentemente los procesos de N-min, C-min y la actividad biológica del suelo. Esta hipótesis fue examinada en un bosque de N. obliqua y una plantación de P. radiata del centro-sur de Chile (40°07' S, 72° O. Se evaluó mensualmente la tasa mineralización de nitrógeno (N-min, cabono (C-min y la actividad enzimática potencial del suelo (ureasa, proteasa e hidrólisis de la fluoresceína diacetato entre septiembre 2003 y mayo 2005. Los resultados demuestran que los niveles de las variables de actividad biológica del suelo fueron significativamente diferentes entre las parcelas de bosque y plantación (Lambda de Wilk = 0,022; F 5,80 = 733; P In Chile, commercial forests plantations have increased during the last decades due in part to replacement of native forests and conversion of agricultural soils. Pinus radiata D. Don has been the main tree planted, due to its rapid growth and adaptability. In the present study we proposed that biological activity varies along the year due to changes of precipitation, temperature and soil water content and mainly because the conversion of native forest to exotic P. radiata plantations alters the soil chemistry, N and C mineralization and the potential enzymatic activity in these soils. This hypothesis was examined in a

An experimental approach to explain the southern Andes elevational treeline.

Science.gov (United States)

Fajardo, Alex; Piper, Frida I

2014-05-01

• The growth limitation hypothesis (GLH) is the most accepted mechanistic explanation for treeline formation, although it is still uncertain whether it applies across taxa. The successful establishment of Pinus contorta--an exotic conifer species in the southern hemisphere--above the Nothofagus treeline in New Zealand may suggest a different mechanism. We tested the GLH in Nothofagus pumilio and Pinus contorta by comparing seedling performance and carbon (C) balance in response to low temperatures.• At a southern Chilean treeline, we grew seedlings of both species 2 m above ground level, to simulate coupling between temperatures at the meristem and in the air (colder), and at ground level, i.e., decoupling air temperature (relatively milder). We recorded soil and air temperatures as well. After 3 yr, we measured seedling survival and biomass (as a surrogate of growth) and determined nonstructural carbohydrates (NSC).• Nothofagus and Pinus did not differ in survival, which, as a whole, was higher at ground level than at the 2-m height. The root-zone temperature for the growing season was 6.6°C. While biomass and NSC decreased significantly for Nothofagus at the 2-m height compared with ground level (C limitation), these trends were not significant for Pinus• The treeline for Nothofagus pumilio is located at an isotherm that fully matches global patterns; however, its physiological responses to low temperatures differed from those of other treeline species. Support for C limitation in N. pumilio but not in P. contorta indicates that the physiological mechanism explaining their survival and growth at treeline may be taxon-dependent. © 2014 Botanical Society of America, Inc.

Wellington Quaternary palynology

International Nuclear Information System (INIS)

Harris, W.F.; Mildenhall, D.C.

1984-01-01

Pollen samples from a profile at Taita indicate a grassland environment prior to and immediately after the deposition of the Aokautere Ash (Kawakawa Tephra) approximately 21,000 years B.P. This grassland gradually gave way to a Nothofagus menziesii montane forest followed by an abrupt change to a N. ''Fusca'' group dominant forest which continues to the top of the section. The top few centimetres of the profile may have been deposited in post-European time. The abrupt change in the species of beech represents an unconformity of unknown duration. Pollen samples from a number of profiles at Mangaroa (Wallaceville Swamp) indicate a change from a cool environment (Gramineae plus Phyllocladus) through successive phases of Nothofagus menziesii, Podocarpus species, Dacrydium cupressinum to Nothofagus ''fusca'' group close to the present day. These results are presented in an historical context based on notes left by Dr W.F. Harris, supplemented with additional data by the junior author

Micro-environmental changes induced by shape and size of forest openings: effects on Austrocedrus chilensis and Nothofagus dombeyi seedlings performance in a Pinus contorta plantation of Patagonia, Argentina

Energy Technology Data Exchange (ETDEWEB)

Pafundi, L.; Urretavizcaya, M.F.; Defosse, G.E.

2016-07-01

Aim of the study: to analyze, within a Pinus contorta plantation, the effects of artificially created small rectangular and small medium circular canopy gaps on: i) photosynthetic active radiation (PAR), and soil temperature and moisture, and ii) survival and growth of planted Austrocedrus chilensis and Nothofagus dombeyi seedlings, species which formerly composed the natural forest of the area. Study area: A 2 ha stand of a Pinus contorta stand in Los Alerces National Park, Argentina (42°43’S, 71°43’W, 490 m.a.s.l.). Material and methods: The Pinus contorta stand was 25 yr old, 22 m height and 26 cm DBH, presenting 1000 trees ha-1 of density and 53 m2 ha-1 of basal area. In 2009, rectangular and circular gaps were created within the stand and then seedlings were planted. During two growing seasons (2010-2011 and 2011-2012), PAR, soil temperature and moisture were measured in gaps and understory (control), and seedling survival and growth in gaps. Main results: During both seasons, soil temperature did not differ among gaps and control, whereas PAR and soil moisture were lower in control than in gaps. Seedling survival was high in all gaps regardless of species and season. Seedlings showed higher diameter growth in rectangular than in circular gaps. Research highlights: Austrocedrus chilensis and N. dombeyi seedlings survival is high and their growth slightly affected, when planted in differently-sized canopy gaps within a Pinus contorta plantation in Patagonia. However, other gap sizes and stand densities should be tested before recommending which one shows better results for reconverting monocultures into former native forests. Abbreviations used: PAR (Photosynthetic Active Radiation); DBH (Diameter at Breast Height); INTA (Argentinean Institute of Agricultural Technology); IFONA (Argentinean Forest Institute). (Author)

Influencia del ciclo lunar en la captura de langosta espinosa Panulirus argus (Decapoda: Palinuridae en el Golfo de Batabanó, Cuba

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Alexander Lopeztegui

2011-03-01

Full Text Available Muchos procesos biológicos tales como los comportamientos reproductivos y migratorios se han asociado con los ciclos de la luna. Con el objetivo de determinar la relación entre las capturas de langosta espinosa Panulirus argus (Decapoda: Palinuridae y el ciclo lunar, en la zona del Golfo de Batabanó, se correlacionaron los niveles de iluminación nocturna del ciclo lunar (INT con la captura diaria por barco (CDB durante siete meses lunares correspondientes al período de pesca del 2002. Los datos de captura provinieron de las tres empresas pesqueras que realizan su actividad en la zona del Golfo de Batabanó. La relación entre el ciclo lunar y las capturas de langostas fue examinada mediante varios procedimientos estadísticos. Los primeros gráficos realizados, cualitativos, mostraron que no existe relación entre las tasas de captura y el ciclo lunar. Los coeficientes de Spearman calculados, modularmente menores que 0.1 en todos los casos, demostraron cuantitativamente que no existe correlación entre las mencionadas variables. La prueba de Kruskal-Wallis detectó diferencias sólo en una de las tres áreas estudiadas. Las correlaciones cruzadas no detectaron significación en ninguna de las zonas, con coeficientes de correlación cruzada modularmente inferiores a 0.1. A diferencia de lo reportado por otros autores, las capturas de P. argus y el ciclo lunar no presentan correlación significativa en el Golfo de Batabanó.Influence of lunar cycle on catches of spiny lobster Panulirus argus (Decapoda: Palinuridae in the Gulf of Batabanó, Cuba. Many biological processes such as reproductive and migratory behaviours have been associated with moon cycles. In this study, the nocturnal light levels associated with lunar cycle (INT were correlated with daily catch rate of lobster P. argus, during seven lunar months of 2002 fishing period, to determine a possible relationship between these variables. The lobster catches were obtained from three

Imprints of Climate Signals in a 204 Year δ18O Tree-Ring Record of Nothofagus pumilio From Perito Moreno Glacier, Southern Patagonia (50°S

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Jussi Grießinger

2018-04-01

Full Text Available A 204 year-long record of δ18O in tree-ring cellulose of southern beech (Nothofagus pumilio from a site near Perito Moreno Glacier (50°S in Southern Patagonia was established to assess its potential for a climate reconstruction. The annually resolved oxygen isotope chronology is built out of seven individual tree-ring δ18O series with a significant mean inter-series correlation (r = 0.61 and is the first of its kind located in Southern America south of 50°S. Over a common period from 1960 to 2013 of available stationary and high-resolution gridded CRU TS v. 4.01 data, the δ18O chronology exhibits a strong sensitivity toward hydroclimatic as well as temperature parameters as revealed by correlation analyses. Among these, positive correlations with maximum temperature in the first part of the summer season (CRU rONDJ = 0.51, p < 0.01 and negative correlations with precipitation in the latter half of the vegetation period (CRU rONDJ = −0.54, p < 0.01 show the highest sensitivities. A strong supra-regional influence of the Southern Annular Mode (SAM is clearly recorded in this chronology as indicated by significant positive correlations during the vegetation period (rONDJ = 0.62, p < 0.01. This indicates that the presented δ18O-chronology shows great promise to reconstruct the influence and variability of the SAM within the last two centuries in southern South America. The modulation of positive and negative anomalies within this series can be interlinked to changes in moisture source origin as revealed by backward trajectory modeling. Additionally, these anomalies can be directly associated to positive or negative phases of the Antarctic Oscillation Index (AAOI and therefore the strength of the Westerlies. Aligned by the analysis on the influence of different main weather types on the δ18O chronology it is shown that such time-series hold the potential to additionally capture their respective influence and change during the last centuries.

Materia extraña

CERN Document Server

Gómez Cadenas, J J

2008-01-01

Enero, 1999. Unas extrañas burbujas se han colocado en el acelerador de particulas del CERN (Ginebra). Ante el riesgo de que esto desencadene una catástrofe a escala mundial, el centro ordena detener el experimento. Años después, Irene, una joven y promotedora científica, es contratada en la división de Física Teórica del CERN. Allí coincide con el mayor Espinosa, destinado a la sede suiza de la ONU para trabajar en un proyecto contra la proliferación de armas nucleares. La misión de Espinosa resulta ser mucho más arriesgada de lo que parecía. Irene ambiciosa y rebelde, toma una decisión de efectos imprevisibles.

Características del establecimiento e historia de vida de Misodendrum punctulatum (Misodendraceae un muérdago de Sudamérica austral Establishment and life history characteristics of the southern South American mistletoe Misodendrum punctulatum (Misodendraceae

Directory of Open Access Journals (Sweden)

Norlan Tercero-Bucardo

2004-09-01

Full Text Available Aprovechando la formación de anillos anuales de crecimiento en los hospedadores y que el sistema haustorial de los muérdagos va quedando sincrónicamente embebido en el xilema del hospedador, analizamos características edad dependientes de la historia de vida y del establecimiento de Misodendrum punctulatum cuando infecta a dos especies deciduas de Nothofagus en el noroeste de la Patagonia, Argentina. La determinación de la edad de establecimiento de las infecciones fue realizada examinando el número de anillos anuales de crecimiento del hospedador, en cortes transversales de ramas o troncos principales de Nothofagus, atravesados por el haustorio más profundo. Concomitantemente, se registró el número de eventos anuales de crecimiento (índice de edad aérea y el diámetro basal de los tallos de los muérdagos. Los anillos de crecimiento de los hospedadores precedentes al establecimiento de los muérdagos fueron usados para determinar la edad las ramas o troncos principales al ser infectados. La relación entre la edad haustorial y el índice de edad aérea indican que: (1 el recuento de los eventos de crecimiento de los tallos es un método no destructivo adecuado para estimar la edad de este muérdago mientras que el diámetro basal es un método menos eficiente, (2 al inicio del desarrollo M. punctulatum presenta un período de incubación holotrófico, de varios años, antes de producir estructuras aéreas, (3 la duración del período de incubación es sitio y/u hospedador dependiente siendo más extenso (4 a 6 años en bosques subalpinos de Nothofagus pumilio y más corto (2 años en matorrales de N. antarctica en bajas altitudes ,(4 cuando los muérdagos viven en bosques subalpinos de Nothofagus pumilio en sitios desfavorables crecen más lento y son más longevos que cuando están en matorrales de N. antarctica en bajas altitudes. Misodendrum punctulatum infecta principalmente ramas jóvenes (Taking advantage of host annual ring

Browse Title Index

African Journals Online (AJOL)

Items 251 - 300 of 1250 ... Ricardo Gomez-Flores, David Espinosa-Ramos, Ramiro ... Porfiria Barrón- Gonzalez, Patricia Tamez-Guerra, Reyes Tamez-Guerra, ... TC Fleischer, MLK Mensah, AY Mensah, G Komlaga, SY Gbedema, H Skaltsa.

Stand structure and regeneration of harvested Araucaria araucana ...

African Journals Online (AJOL)

Stand structure and regeneration of harvested Araucaria araucana–Nothofagus stands in central Chile. Rafael M Navarro-Cerrillo, Fernando Olave, Francisco Moreno, Sergio de Miguel, Margarita Clemente ...

Area Handbook Series: El Salvador: A Country Study

Science.gov (United States)

1990-01-01

the majority of these people was no longer completely Indian. Most were ladinoized, Hispanic acculturated, monolingual Spanish speakers who did not wear...Latin American Historical Dictionaries , No. 5.) Metuchen, New Jersey: Scare- crow Press, 1972. Harris, Kevin, and Mario Espinosa. "Reform

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Good linear correlations between IHB energies based on Espinosa's equation and -()/() values, total electronic density, Laplacian of total electronic density in critical points, -electron delocalization parameter (), hyper conjugative interaction energy of lp(N) → *(N-H), (,/,)2 parameter, natural charges of ...

Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients.

Science.gov (United States)

Fajardo, Alex; Piper, Frida I; Hoch, Günter

2013-08-01

The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations. Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra). Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.

Notes on bolete taxonomy

NARCIS (Netherlands)

Singer, R.

1973-01-01

Newly discovered mycorrhizal relationships of boletes (with Nothofagus, Shorea, Quercus humboldtii, Alnus jorullenses, Eucalyptus, and Leptospermum) are discussed. Type studies on Fistulinella, Boletus granulatus var. capricollensis, Boletogaster, and Gastroboletus are reported. The following new

El tamaño del daño

OpenAIRE

José Eduardo Rueda Enciso

2000-01-01

Chajeradó, el río de la caña flecha partida. Luz Marcela Duque, Iván Darío Espinosa, Afda Cecilia Gálvez, Diego Herrera y Sandra María Turbay. Premios Nacionales Colcultura 1996, Colcultura, Bogotá, 1997, 477 págs.

The sacral autonomic outflow is parasympathetic: Langley got it right.

Science.gov (United States)

Horn, John P

2018-04-01

A recent developmental study of gene expression by Espinosa-Medina, Brunet and colleagues sparked controversy by asserting a revised nomenclature for divisions of the autonomic motor system. Should we re-classify the sacral autonomic outflow as sympathetic, as now suggested, or does it rightly belong to the parasympathetic system, as defined by Langley nearly 100 years ago? Arguments for rejecting Espinosa-Medina, Brunet et al.'s scheme subsequently appeared in e-letters and brief reviews. A more recent commentary in this journal by Brunet and colleagues responded to these criticisms by labeling Langley's scheme as a historical myth perpetuated by ignorance. In reaction to this heated exchange, I now examine both sides to the controversy, together with purported errors by the pioneers in the field. I then explain, once more, why the sacral outflow should remain known as parasympathetic, and outline suggestions for future experimentation to advance the understanding of cellular identity in the autonomic motor system.

Strategies of the protozoan parasite Entamoeba histolytica to evade ...

Indian Academy of Sciences (India)

Unknown

and the subsequent migration of the amoeba to the liver where abscesses are formed (Espinosa-Cantellano and. Martinez-Paloma 2000; Stanley 2001). ..... activity of bacterial peroxiredoxins; Nature (London) 407. 211–215. Cario E and Podolsky D K 2000 Differential alteration in intes- tinal epithelial cell expression of ...

Influencia de la despolarización atrial en la velocidad de conduccion y refractariedad en la unión atrioventricular /

OpenAIRE

Molina Fernández de Lara, Luis Gerardo

2012-01-01

 tesis que para obtener el grado de Doctorado en Ciencias Medicas, presenta Luis Gerardo Molina Fernández de Lara ; asesor Ruy Pérez Tamayo, David Kershenobich Stalnikowitz, Juan Garduño Espinosa75 páginas : ilustracionesDoctorado en Ciencias Medicas UNAM, Facultad de Medicina, 2012

Resultados gestacionais e perinatais de gestações com insuficiência cervical submetidas a circlagem eletiva Gestational and perinatal outcomes of pregnancies with cervical incompetence submitted to elective cerclage

Directory of Open Access Journals (Sweden)

Marcelo Luís Nomura

2003-08-01

Full Text Available OBJETIVO: descrever os resultados gestacionais de uma série de gestantes submetidas a circlagem cervical eletiva. MÉTODOS: estudo retrospectivo descritivo de 123 gestações em 116 pacientes submetidas a circlagem eletiva por insuficiência cervical, pelas técnicas de Espinosa-Bahamondes, Palmer ou MacDonald, e acompanhadas no Ambulatório de Pré-Natal Especializado do CAISM/UNICAMP. As variáveis foram analisadas por meio frequência, média e desvio-padrão e comparadas pelo teste de c² ou o teste exato de Fisher. RESULTADOS: 73% das pacientes apresentavam pelo menos um abortamento prévio, 17,9% tinham 3 ou mais abortamentos anteriores e 48% tinham antecedente de parto prematuro. A idade gestacional média de realização da circlagem foi 16 semanas. Houve predomínio de utilização da técnica cirúrgica de Espinosa modificada por Bahamondes (94,3%. A incidência de complicações durante a gestação foi de 69%; a do trabalho de parto prematuro (31,7% foi a mais freqüente, seguido de vaginites/vaginose (26%, ruptura prematura pré-termo de membranas (10,5% e óbito fetal (8,7%, As principais intercorrências clínicas associadas foram infecção do trato urinário (5,6%, síndromes hipertensivas (4% e diabete gestacional (2,4%. O índice de perdas gestacionais foi de 8,9% (11 óbitos fetais. Houve 18% de partos prematuros e o antecedente de parto prematuro associou-se à ocorrência de partos prematuros na gestação em estudo. CONCLUSÕES: os antecedentes obstétricos compatíveis com insuficiência istmocervical foram freqüentes e o antecedente de parto prematuro associou-se a ocorrência de partos prematuros na gestação em estudo. A utilização de circlagem a Espinosa-Bahamondes resultou em taxa de 18% de partos prematuros e de 104 em mil de morte perinatal. São necessários estudos prospectivos controlados para avaliar o real benefício da circlagem cervical durante a gravidez.PURPOSE: to describe the pregnancy outcome of

El Lenguaje de los Chicanos (The Language of Chicanos). Regional and Social Characteristics of Language Used by Mexican Americans.

Science.gov (United States)

Hernandez-Chavez, Eduardo, Ed.; And Others

The following articles are included in this anthology on Chicano speech: (1) "Mexican Spanish," D.N. Cardenas; (2) "The Archaic and the Modern in the Spanish of New Mexico," J. Ornstein; (3) "Problemas Lexicograficos del Espanol del Sudoeste," A.M. Espinosa, Jr.; (4) "Associative Interference in New Mexican Spanish," J.B. Rael; (5) "Some Aspects…

Potential biotechnological application of mycorrhizas and yeasts associated with Nathofagus nervosa (Rauli)

Energy Technology Data Exchange (ETDEWEB)

Fernandez, N.; Fontenla, S.; Gallo, L.; Marchelli, P.

2009-07-01

Nothofagus nervosa is an ecologically and economically important species of south American temperate forests. In Argentina, it has a reduced natural distribution area due to over exploitation, overgrazing and forest fires. This critical situation led to the implementation of conservation and domestication programs. (Author)

Subantarctic forest ecology : case study of a conifer-broadleaved stand in Patagonia, Argentina

NARCIS (Netherlands)

Dezzotti, A.

2000-01-01

In the temperate rainforests of southern South America, the tree genus Nothofagus (Nothofagaceae) is the dominant in extension and abundance on zonal soils at different latitudes and altitudes, as well as on intrazonal (e.g., wetlands) and azonal soils (e.g., morrenic

Use of tree species by White-throated treerunner (Pygarrhichas albogularis King in a secondary native forest of southern Chile

Directory of Open Access Journals (Sweden)

Alberto Gantz

2015-06-01

Full Text Available ABSTRACT In forest ecosystems, numerous species of insectivorous birds use certain tree species as feeding and nesting substrates. Between 2009 and 2010, the use of different floristic components as feeding substrate by the Pygarrhichas albogularis King, 1831 was evaluated in a southern Chilean secondary native forest. From a total of 13 trees and bush species, six tree species were used by P. albogularis as a feeding substrate. Tree use was limited to intermediate heights (11-20 m and, mainly, to the trunk (40% of observations and secondary branches (26%. Pygarrhichas albogularis showed a disproportionated use of N. dombeyi and an important use of trees with a greater age structure (DBH 81-100 cm. Nothofagus dombeyi presented a significantly greater tree bark crevice depth than E. cordifolia. In turn, covariance between crevice depth and invertebrate supply in tree bark was positive and significant. We consider bark depth and invertebrate supply to be the proximate causes explaining P. albogularis disproportionated use of Nothofagus dombeyi.

Administración del capital intelectual y redes empresariales : estudio de la industria cerámica en México y en Italia /

OpenAIRE

Carreto Sanginés, Jorge sustentante.

2009-01-01

 tesis que para obtener el grado de Doctor en Ciencias de la Administración, presenta Jorge Carreto Sanginés ; asesor Sergio Javier Jasso Villazul, Jorge Basave Kunhardt, Roberto Moreno Espinosa. III, 284 páginas : ilustraciones. Doctorado en Ciencias de la Administración UNAM, Facultad de Contaduría y Administración, 2009

In Galápagos … and Uncomfortable with Evolution

Science.gov (United States)

Cotner, Sehoya; Graczyk, Hannah; Rodríguez Garcia, José Luis; Moore, Randy

2016-01-01

In June 2013, the third World Evolution Summit convened on San Cristóbal, hosting scientists from around the world (Paz-y-Miño-C and Espinosa 2013)--neither the first nor likely the last gathering of biologists on these remote islands. Clearly, both locals and an international audience perceive Galápagos as figuring prominently in discourse about…

NUEVA LOCALIDAD GEOGRAFICA PARA BERBERIS NEGERIANA TISCHLER (BERBERIDACEAE) EN LA PROVINCIA DE ARAUCO, REGION DEL BIO-BIO, CHILE

OpenAIRE

Gómez, Persy; Belov, Michail; San Martín, José

2008-01-01

This note reports the finding of a population of Berberis negeriana Tischler (Berberidaceae), in the province of Arauco, Bío-Bío Region (37°42'17" S y 73°19'43" W) in the center south of Chile. The population was found between Nothofagus obliqua and species of the Valdiviano Forest.

Modulation of Fire Regimes by Vegetation and Site Type in Southwestern Patagonia Since 13 ka

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Patricio I. Moreno

2018-04-01

Full Text Available The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51°S. We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, ~28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last ~13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last ~4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, ~12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.

The influence of canopy-layer composition on understory plant diversity in southern temperate forests

Directory of Open Access Journals (Sweden)

Luciana Mestre

2017-05-01

Full Text Available Background Understory plants represents the largest component of biodiversity in most forest ecosystems and plays a key role in forest functioning. Despite their importance, the influence of overstory-layer composition on understory plant diversity is relatively poorly understood within deciduous-evergreen broadleaved mixed forests. The aim of this work was to evaluate how tree overstory-layer composition influences on understory-layer diversity in three forest types (monospecific deciduous Nothofagus pumilio (Np, monospecific evergreen Nothofagus betuloides (Nb, and mixed N. pumilio-N. betuloides (M forests, comparing also between two geographical locations (coast and mountain to estimate differences at landscape level. Results We recorded 46 plant species: 4 ferns, 12 monocots, and 30 dicots. Canopy-layer composition influences the herb-layer structure and diversity in two different ways: while mixed forests have greater similarity to evergreen forests in the understory structural features, deciduous and mixed were similar in terms of the specific composition of plant assemblage. Deciduous pure stands were the most diverse, meanwhile evergreen stands were least diverse. Lack of exclusive species of mixed forest could represent a transition where evergreen and deciduous communities meet and integrate. Moreover, landscape has a major influence on the structure, diversity and richness of understory vegetation of pure and mixed forests likely associated to the magnitude and frequency of natural disturbances, where mountain forest not only had highest herb-layer diversity but also more exclusive species. Conclusions Our study suggests that mixed Nothofagus forest supports coexistence of both pure deciduous and pure evergreen understory plant species and different assemblages in coastal and mountain sites. Maintaining the mixture of canopy patch types within mixed stands will be important for conserving the natural patterns of understory plant

Anna Mouglalis kõikide vastu / Anna Mouglalis ; intervjueerinud Guillermo Espinosa

Index Scriptorium Estoniae

Mouglalis, Anna

2010-01-01

Prantsuse moekunstniku Coco Chaneli ja vene helilooja Igor Stravinki armuloost rääkivas filmis "Coco Chanel & Igor Stravinski" mängib peaosa Chaneli moemaja modell ja reklaaminägu. Intervjuus endast ja oma rollidest

A pollen-based record of late glacial-Holocene climatic variability in the southern lake district, Chile

NARCIS (Netherlands)

Vargas-Ramirez, L.; Roche, E.; Gerrienne, P.; Hooghiemstra, H.

2008-01-01

A pollen record from Puyehue area (40°S; 72°W) in the southern Lake District, Chile, indicates that prior to 13,410 14C yr BP (ca. 16,500-15,200 cal yr BP), cold resistant and hygrophilous vegetation, particularly Nothofagus forest and myricaceous vegetation, covered the area. From ca. 15,000 cal yr

Análise sobre as emoções no livro Teoría de las emociones (Vigotski

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Áurea Júlia de Abreu Costa

2012-01-01

Full Text Available O tratamento dado às emoções como objeto de investigação em psicologia transitou entre a negligência e a depreciação. Contudo, observamos atualmente o ressurgimento do interesse pelo estudo acerca dessa temática. Nesse contexto, consideramos pertinente retomar e discutir algumas contribuições de Vigotski concernentes às emoções. O presente trabalho buscou analisar aspectos apontados por Vigotski no manuscrito intitulado Teoría de las emociones - estúdio histórico-psicológico. Centramo-nos na crítica do autor ao dualismo que caracterizava tanto a teoria organicista das emoções (explicativa, quanto à apropriação puramente filosófica, idealista (descritiva dessas. Discutimos ainda o possível entrave de cunho teórico-metodológico ao projeto de Vigotski de fundamentar a sua teoria nas contribuições do filósofo Espinosa: as divergências entre a perspectiva materialista histórico-dialética e o racionalismo/idealismo de Espinosa. Embora não tenha alcançado o seu objetivo de produzir uma teoria materialista-dialética das emoções, Vigotski inovou ao buscar integrar arte, ética e ciência em sua análise.

Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

Science.gov (United States)

Juárez, Andrea; Arribére, María A; Arcagni, Marina; Williams, Natalia; Rizzo, Andrea; Ribeiro Guevara, Sergio

2016-09-01

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

Ill Posedness Results for Generalized Water Wave Models

OpenAIRE

Teyekpiti, Vincent Tetteh

2013-01-01

In the first part of the study, the weak asymptotic method is used to find singular solutions of the shallow water system in both one and two space dimensions. The singular solutions so constructed are allowed to contain Dirac-delta; distributions (Espinosa & Omel'yanov, 2005). The idea is to con- struct complex-valued approximate solutions which become real-valued in the distributional limit. The approach, which extends the range f possible singular solutions, is used to construct solutions ...

Prácticas de participación política desde la frontera sur cordobesa: redes, vínculos y faccionalismo a partir de un estudio de caso (fines del siglo XIX

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Luciano Nicola Dapelo

2015-01-01

Full Text Available Este artículo aborda la trayectoria vital de Manuel Antonio Espinosa, un militar deorigen tucumano que acciona políticamente desde la ciudad fronteriza de Río Cuarto.El objetivo de la investigación se concentra en reconstruir la vida Manuel, con elobjeto de elucidar las prácticas y estrategias implementadas por los individuos paraconstruir poder político, en el marco de la consolidación de la “Argentina Moderna”,en la segunda mitad del siglo XIX. Así, complementariamente, se analizará laconstitución de vínculos familiares y amistosos, como una herramienta clave en lacomprensión de las prácticas sociales de las élites finiseculares y sus movimientosestratégicos, que llevaron adelante, para consolidar su poder.De esta manera, se presenta el trayecto vital de Espinosa, como sujeto y como objetode la investigación, reconstruyendo parcialmente aspectos de su vida teniendo encuenta las dificultades respecto de las fuentes, que son fragmentarias y dispersas,pero que permiten armar un relato coherente, que posibilita identificar las prácticassociales de construcción y acumulación de poder. Esto constituye una herramientapara comprender los usos sociales que operan en y desde el espacio fronterizosurcordobés, de rol protagónico en la Argentina de la segunda mitad del siglo XIX.

New host-plant records for the defoliator Ormiscodes amphimone (Fabricius) (Lepidoptera: Saturniidae).

Science.gov (United States)

Paritsis, Juan; Elgueta, Mario; Quintero, Carolina; Veblen, Thomas T

2010-01-01

Ormiscodes amphimone (Fabricius) is a phytophagous moth species known to severely defoliate woody species in Chile and Argentina. Here we document new records of O. amphimonehost associations emphasizing the role of Nothofagus pumilio as its primary host in our study area. This new record for Argentina is highly significant given the economic importance of N. pumilio as a timber resource and the potential of O. amphimone to generate extensive outbreaks.

New host-plant records for the defoliator Ormiscodes amphimone (Fabricius) (Lepidoptera: Saturniidae)

OpenAIRE

Paritsis, Juan; Elgueta, Mario; Quintero, Carolina; Veblen, Thomas T

2010-01-01

Ormiscodes amphimone (Fabricius) is a phytophagous moth species known to severely defoliate woody species in Chile and Argentina. Here we document new records of O. amphimonehost associations emphasizing the role of Nothofagus pumilio as its primary host in our study area. This new record for Argentina is highly significant given the economic importance of N. pumilio as a timber resource and the potential of O. amphimone to generate extensive outbreaks.

Nova Talenta: 2014-2015

OpenAIRE

Aguilera Velandia, Mónica Natalia; Álvarez Rodríguez, María Isabel; Báez Millán, Christian Danilo; Cuestas Díaz, Andrea Patricia; Escobar Campos, Lina Marcela; Galindo Londoño, Ana María; García Sierra, María Camila; García, Lina María; Jaramillo Barrios, María Paola; Mesa Torres, Karen Eliana; Mora Barrero, Daniel; Morales Morales, Ángela Beatriz; Moreno, Ana María; Naranjo Pinilla, Juan Sebastian; Ochoa Rodríguez, Ángela Marcela

2015-01-01

Contenido Introducción 1. Inteligencia emocional, liderazgo transformacional y género: factores que influencian el desempeño organizacional / Ana María Galindo Londoño, Sara Urrego Mayorga; Director: Juan Carlos Espinosa Méndez. 2. El rol de la mujer en el liderazgo / Andrea Patricia Cuestas Díaz; Directora: Francoise Venezia Contreras Torres. 3. Liderazgo transformacional, clima organizacional, satisfacción laboral y desempeño. Una revisión de la literatura / Juliana Restrepo O...

Veinte años de experiencia en el manejo de la mujer embarazada infectada por VIH/SIDA en el Instituto Nacional de Perinatología

OpenAIRE

Plazola-Camacho, Noemí Guadalupe; Ortiz-Ibarra, Federico Javier

2009-01-01

Introducción. Objetivos: revisar las recomendaciones internacionales e informar la experiencia que se tiene en el manejo y seguimiento de mujeres embarazadas infectadas por virus de inmunodeficiencia humana (VIH)/síndrome de inmunodeficiencia adquirida (SIDA) en el Instituto Nacional de Perinatología Isidro Espinosa de los Reyes (INPerIER). Métodos. Se presenta la experiencia clínica de 20 años (1988-2008) en el manejo de una cohorte de mujeres embarazadas infectadas por VIH atendidas en el I...

Ecotopes, Natural Infection and Trophic Resources of Triatoma brasiliensis (Hemiptera, Reduviidae, Triatominae

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Jane Costa

1998-01-01

Full Text Available Triatoma brasiliensis is considered as one of the most important Chagas disease vectors in the northeastern Brazil. This species presents chromatic variations which led to descriptions of subspecies, synonymized by Lent and Wygodzinsky (1979. In order to broaden bionomic knowledge of these distinct colour patterns of T. brasiliensis, captures were performed at different sites, where the chromatic patterns were described: Caicó, Rio Grande do Norte (T. brasiliensis brasiliensis Neiva, 1911, it will be called the "brasiliensis population"; Espinosa, Minas Gerais (T. brasiliensis melanica Neiva & Lent 1941, the "melanica population" and Petrolina, Pernambuco (T. brasiliensis macromelasoma, Galvão 1956, the "macromelasoma population". A fourth chromatic pattern was collected in Juazeiro, Bahia the darker one in overall cuticle coloration, the "Juazeiro population". At the sites of Caicó, Petrolina and Juazeiro, specimens were captured in peridomiciliar ecotopes and in wilderness. In Espinosa the specimens were collected only in wilderness, even though several exhaustive captures have been performed in peridomicile at different sites of this municipality. A total of 298 specimens were captured. The average registered infection rate was 15% for "brasiliensis population" and of 6.6% for "melanica population". Specimens of "macromelasoma" and of "Juazeiro populations" did not present natural infection. Concerning trophic resources, evaluated by the precipitin test, feeding eclecticism for the different colour patterns studied was observed, with dominance of goat blood in household surroundings as well as in wilderness

Assessing the impact of plantation forestry on plant biodiversity

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Andreas Ch. Braun

2017-04-01

Full Text Available Effects of plantation forestry on biodiversity are controversially discussed in literature. While some authors stress positive effects, others tend to attribute a largely negative influence to plantations. One important factor steering the influence on biodiversity are management practices. A second important factor is the environmental matrix. Chile offers the option to analyse both factors jointly. The coastal range of central Chile has experienced rapid and widespread replacement of native Nothofagus spp. forests in favour of Pinus radiata plantations. Here, native forests remain limited to small patches surrounded by an environmental matrix of plantations. Management is rather intensive and not designed to maintain biodiversity. While in the coastal range of central Chile the transformation from native forests to non-native tree plantations has almost come to an end, spatial extension of P. contorta and P. ponderosa plantations has just recently begun in Chilean Patagonia. While the management is similar to central Chile, plantations rather exist as small patches surrounded by an environmental matrix of native plant formations (e.g. Nothofagus spp. forests and Nothofagus spp. scrublands. In the framework of this work, effects of the two diametric land usages on biodiversity are assessed and compared. Biodiversity is assessed at the α-, β- and γ-scale. At the α-scale, biodiversity impacts are inferred statistically, using one-way ANOVA and Tukey’s PostHoc test. Biodiversity of plants at both sites is significantly reduced in plantations when compared to native forests or scrublands. Plantation forestry lowers α-biodiversity and does not provide additional habitats for specialists. At the β-scale, weak edge effects due to the presence of native forests are observed. In total, plantation forestry tends to promote plant invasions and impairs the survival of endemics. At the γ-scale, plant species communities where predominantly native

Perfiles e indicadores psicológicos relacionados con la dispareunia y el vaginismo. Estudio cuantitativo. Primera parte

OpenAIRE

Sánchez Bravo, Claudia; Carreño Meléndez, Jorge; Corres Ayala, Norma Patricia; Henales Almaraz, Consuelo

2010-01-01

Antecedentes En el Departamento de Psicología del Instituto Nacional de Perinatología Isidro Espinosa de los Reyes (INPerIER), se encontró una alta prevalencia de disfunciones sexuales: 52% en las mujeres y 38.8% en los hombres, además de que otros estudios comparativos indican que la población que presentó alteraciones en la vida sexual mostró siempre desventaja en factores como el autoconcepto, la asertividad, la satisfacción marital, el estilo de comunicación y la comunicación marital, en ...

Preliminary data on growth and enzymatic abilities of soil fungus Humicolopsis cephalosporioides at different incubation temperatures.

Science.gov (United States)

Elíades, Lorena Alejandra; Cabello, Marta N; Pancotto, Verónica; Moretto, Alicia; Rago, María Melisa; Saparrat, Mario C N

2015-01-01

Nothofagus pumilio (Poepp & Endl.) Krasser, known as "lenga" is the most important timber wood species in southernmost Patagonia (Argentina). Humicolopsis cephalosporioides Cabral & Marchand is a soil fungus associated with Nothofagus pumilio forests, which has outstanding cellulolytic activity. However, there is no information about the ability of this fungus to use organic substrates other than cellulose, and its ability to produce different enzyme systems, as well as its response to temperature. The aim of this study was to examine the role of H. cephalosporioides in degradation processes in N. pumilio forests in detail by evaluating the in vitro ability of four isolates of this fungus to grow and produce different lytic enzyme systems, and their response to incubation temperature. The ability of the fungi to grow and produce enzyme systems was estimated by inoculating them on agar media with specific substrates, and the cultures were incubated at three temperatures. A differential behavior of each strain in levels of growth and enzyme activity was found according to the medium type and/or incubation temperature. A intra-specific variability was found in H. cephalosporioides. Likewise a possible link between the saprotrophic role of this fungus in N. pumilio forests and the degradation of organic matter under stress conditions, such as those from frosty environments, was also discussed. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

El mundo del libro: agosto de 1961

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Agustín Rodríguez Garavito

1961-08-01

Full Text Available El documento presenta las reseñas de los siguientes títulos: Afuera, las estrellas. Por Matilde Espinosa de Pérez. Editorial Guadalupe - Bogotá, D. E. Damazo Zapata o La reforma educacionista en Colombia. Por Ramón Zapata. Flor de corralitos de piedra. Por Daniel Lemaitre. Arrieros y fundadores. Por Eduardo Santa. Editorial Cosmos - Bogotá, D. E. De la pseudo-aristocracia a la autenticidad. Psicología social colombiana. Por José Gutierrez. Mexico, 1961. Caucania. Por Raúl Silva Holguín. Cali - Colombia. Gregorio Marañon, su vida y su obra. Por Luis S. Grajel.

EL CAMBIO CLIMÁTICO DURANTE LOS ÚLTIMOS 15.000 AÑOS EN PATAGONIA NORTE. RECONSTRUCCIONES DE LA VEGETACIÓN EN BASE A POLEN Y CARBÓN VEGETAL SEDIMENTARIO.

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María Martha Bianchi

2007-12-01

Full Text Available Los cambios de la vegetación, en cuencas lacustres en la región del bosque Andino Patagónico y el ecotono bosque-estepa, determinados a partir del análisis de polen y carbón vegetal sedimentario permitieron inferir cambios climáticos en el área de Patagonia norte desde la Tanscición Glacial-Post-glacial, 15.000 años A.P. Se presentan aquí algunos de los resultados más relevantes obtenidos con metodologías de alto nivel, en el área del Parque Nacional Nahuel Huapi durante 17 años de estudio, en los que se extrajeron y analizaron testigos sedimentarios en lagos y mallines: Lago Mascardi, Lago El Trébol, Lago Escondido y Mallín Aguado. Los análisis de polen y de carbón vegetal sedimentario de secuencias bien datadas con el método de 14C indican que una estepa arbustiva fue remplazada por un bosque abierto a comienzos de la Transición Glacial-post-glacial bajo un clima más seco y más frió que el actual. Hacia fines de la Transición se produjo la diversificación del bosque. Durante la Inversión Climática Huelmo Mascardi, el bosque se hizo más abierto hacia el oeste y se produjeron incendios de alta severidad hacia el este, sugiriendo una disminución en la temperatura hacia el oeste y en las condiciones de humedad a lo largo del gradiente Oeste- Este. El bosque de Nothofagus adquirió su mayor extensión y los incendios continuaron durante el Holoceno Inferior. Durante el Holoceno Medio se produjo el reemplazo del bosque de Nothofagus por el bosque mixto de Nothofagus y Austrocedrus chilensis, gracias a un incremento en las precipitaciones, principalmente de verano. La expansión del bosque hacia el este ocurrió gradualmente y fue acompañado por un cambio en el régimen de incendios, los que se hicieron más frecuentes pero menos severos. Durante el Holoceno Superior el bosque se hizo más denso y continuó expandiéndose bajo condiciones de mayor variabilidad climática. Actualmente las investigaciones contin

Construcción de viviendas de módulos hexagonales

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Editorial, Equipo

1975-05-01

Full Text Available This article describes the origin of this system of prefabrication with elements of reinforced concrete, based on the appropriate combination of numerical proportions; with a definition of each single piece that forms part of the construction of a housing block; mounting of the building, fabrication of the different pieces and the total number of pieces that each housing consists of. The idea of this type of housings, its construction form and assembly of pieces For préfabrication is an accomplishment of Dr. Emilio González Espinosa de los Monteros. Industrial Engineer. At present the system is being applied to the construction of a block of 88 housings, in 11 storeys which is a project by the architects Eduardo Ramos Guerbós and Antonio Garcia Garrido.Se describe en el artículo el origen creacional de este sistema de prefabricación con piezas de hormigón armado, basado en la adecuada combinación de proporciones matemáticas; con definición de todas y cada una de las piezas que intervienen en la construcción de un bloque en altura de viviendas; montaje del edificio, fabricación de las diferentes piezas y número de ellas que interviene en cada vivienda. La idea de este tipo de viviendas, su forma constructiva y conjunto de piezas para la prefabricación es del Doctor Ingeniero Industrial Emilio González Espinosa de los Monteros, y en la actualidad se está aplicando a la construcción de un bloque de 88 viviendas en 11 plantas, cuyo proyecto es de los arquitectos Eduardo Ramos Guerbós y Antonio García Garrido.

MÚSICA E COGNIÇÃO: INTERFACES ENTRE CULTURA, SOCIEDADE E INTERTEXTUALIDADE

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Onici Claro Flôres

2012-01-01

Full Text Available This paper aims at problematizing the interfaces between music and cognition. In this sense, we understand that the teaching of this hybrid genre, the song, either through the means of its relation with the literature, by intertextuality, or through the melodic-verb piece itself, its reading and or listening, meets the reduction of the differences, once it promotes socialization and interest for culture, literature, and for language, besides the cognitive development of the students. Towards this goal, the present study is based on scholars from several areas of knowledge such as Costa (2002, Espinosa (2011, Genette (2006, Friedrich (1991, Koch (2007, Sacks (2007, Tomasello (2003, Thwaites (1994, among others.

EFECTO DE LA VEGETACIÓN EN LA INTERCEPCIÓN DE LA PRECIPITACIÓN EN LA PRECORDILLERA DE LA REGIÓN DEL MAULE, CHILE

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O. S. Vallejos-Barra

2010-01-01

Full Text Available En este estudio se comparó el comportamiento de un bosque secundario de Roble-Hualo, donde las especies predominantes son Nothofagus obliqua y Nothofagus glauca y una plantación de Pinus radiata D. Don de 12 años de edad, en el proceso precipitación - intercepción. El estudio se desarrolló en la Estación Experimental El Picazo, comuna de San Clemente, Región del Maule, Chile, entre el mes de julio de 2007 a julio de 2008, en dos microcuencas vecinas de dimensiones reducidas con condiciones similares de suelo, exposición y pendiente pero que diferían en la cobertura vegetal. Se caracterizó la vegetación de cada microcuenca y se establecieron indicadores de densidad de parcela. Los indicadores de la cobertura nativa superaron ampliamente a los de las coberturas exóticas. Para registrar la precipitación se instalaron dos pluviógrafos del tipo Hobo en cada microcuenca. Equidistante de ellas se ubicó otro pluviógrafo sin cobertura vegetal. Se registraron 21 tormentas caracterizando temporal y espacialmente el comportamiento de la precipitación abierta y bajo dosel. Los resultados indican que pese a tener diferencias numéricas las coberturas vegetales, éstas no se transforman en diferencias estadísticamente significativas. Además se observó que la intercepción depende en mayor medida de la arquitectura de copa, distribución espacial de los árboles y tipo de hojas, que de la cantidad de árboles por parcela.

Holocene Dynamics of Temperate Rainforests in West-Central Patagonia

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Virginia Iglesias

2018-01-01

Full Text Available Analyses of long-term ecosystem dynamics offer insights into the conditions that have led to stability vs. rapid change in the past and the importance of disturbance in regulating community composition. In this study, we (1 used lithology, pollen, and charcoal data from Mallín Casanova (47°S to reconstruct the wetland, vegetation, and fire history of west-central Patagonia; and (2 compared the records with independent paleoenvironmental and archeological information to assess the effects of past climate and human activity on ecosystem dynamics. Pollen data indicate that Nothofagus-Pilgerodendron forests were established by 9,000 cal yr BP. Although the biodiversity of the understory increased between 8,480 and 5,630 cal yr BP, forests remained relatively unchanged from 9,000 to 2,000 cal yr BP. The charcoal record registers high fire-episode frequency in the early Holocene followed by low biomass burning between 6,500 and 2,000 cal yr BP. Covarying trends in charcoal, bog development, and Neoglacial advances suggest that climate was the primary driver of these changes. After 2,000 cal yr BP, the proxy data indicate (a increased fire-episode frequency; (b centennial-scale shifts in bog and forest composition; (c the emergence of vegetation-fire linkages not recorded in previous times; and (d paludification in the last 500 years possibly associated with forest loss. Our results therefore suggest that Nothofagus-Pilgerodendron dominance was maintained through much of the Holocene despite long-term changes in climate and fire. Unparalleled fluctuations in local ecosystems during the last two millennia were governed by disturbance-vegetation-hydrology feedbacks likely triggered by greater climate variability and deforestation.

Stratigraphy and paleontology of fossil hill Peninsula Fildes, Rey Jorge island, Antarctica: a new approach

International Nuclear Information System (INIS)

Perea, D.; Masquelin, H.; Verde, M.; Guerequiz, R.

1998-01-01

Results of the first Uruguayan paleontologic and biostratigraphical investigations in Antarctica are presented.The field work was performed in Fildes Peninsula, King George Island, near the Uruguayan station Base Cientifica Antartida Artigas. Some fossiliferous outcrops were geologic and pale ontologically analyzed, among them the Fossil Hill, placed in the middle part of the peninsula, in front of Ardley Island between the Chinese and Chilean stations. This hill is composed of fossil bearing piroclastic and epiclastic rocks, assigned to the Fossil Hill Fm.Vegetal remains (petrified wood and leaf impronts)were observed and collected in this unit and it is remarkable the presence of Nothofagus sp. and invertebrate trace fossils Cochlichnus isp and Helminthopsis isp.

Visit of Ambassadors from Latin America, Portugal and Spain to SM18.

CERN Multimedia

Patrice Loïez

2002-01-01

Left to right: Prof. Juan Antonio Rubio, Head of the Education and Technology Transfer Division; H.E. Mr Gustavo Albin, Ambassador, Permanent Representative of Mexico in Geneva; H.E. Mr Joaquìn Pérez-Villanueva y Tovar, Ambassador, Permanent Representative of Spain in Geneva; H.E. Mr Alvaro de Mendonça e Moura, Ambassador, Permanent Representative of Portugal in Geneva, Dr Norbert Siegel, Insertion, Correctors and Protection Group, LHC division; H.E. Mr Juan Enrique Vega, Ambassador, Permanent Representative of Chile in Geneva; Mr Rodrigo Espinosa, Counsellor, Permanent Mission of Chile in Geneva; H.E. Mr Horacio Emilio Solari, Ambassador, Permanent Representative of the Republic of Argentina in Geneva; Dr John Ellis, Adviser for Non-Member State Relations and Mr Enrique Ochoa, Third Secretary, Permanent Mission of Mexico in Geneva.

Hummingbirds and the plants they visit in the Tehuacán-Cuicatlán Biosphere Reserve, Mexico Colibríes y las plantas que visitan en la Reseva de la Biosfera Tehuacán-Cuicatlán, México

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Raúl Ortiz-Pulido

2012-03-01

colibríes más comunes, mientras que C. latirostris, A. violiceps y Cynanthus sordidus fueron las especies que visitaron a un mayor número de especies de plantas. Los colibríes estuvieron distribuidos diferencialmente entre los tipos de vegetación, con 12 especies presentes en la comunidad de plantas arbóreas de tierras bajas, 11 tanto en los bosques de cactus como en la comunidad de plantas perennes arbustivas espinosas, y seis en la comunidad de plantas arbustivas perennes no espinosas. Cercidium praecox (Fabaceae fue la especie con mayor número de especies de colibríes visitantes (10 especies. Las comunidades de bosque de cactus y plantas perennes arbustivas espinosas tuvieron los números más altos de posibles interacciones (57 y 51, respectivamente. El valor de conectancia de las matrices de interacciones fue similar entre las cuatro comunidades de plantas (cercano al 22%, pero más bajo que lo reportado previamente a nivel mundial. En la Reserva de la Biosfera Tehuacán-Cuicatlán el sistema de interacción colibrí-planta puede ser conservado si se protegen las especies de colibríes C. latirostris, A. violiceps, C. sordidus y L. clemenciae, y las de plantas C. praecox, I. arborescens, E. chiotilla y N. glauca.

Plant Responses to Increased UV-B Radiation: A Research Project

Science.gov (United States)

DAntoni, H. L.; Skiles, J. W.; Armstrong, R.; Coughlan, J.; Daleo, G.; Mayoral, A.; Lawless, James G. (Technical Monitor)

1994-01-01

because there is anecdotal evidence of plant damage on the saguaros that has been linked to increased UV radiation, and (3) the forests of Nothofagus spp. and the steppe of Patagonia where the risk of plant damage at 35S is 5% and increases to as much as 15% at 55S due to increased UV-B radiation. Measurements of UV-B radiation impinging on the surface at 55S largely exceed the predicted UV-B radiation values at 50 latitude and 0% ozone depletion. Preliminary HPLC analyses of UV-B absorbing compounds in Nothofagus antartica, N. pumilio, N. betuloides and Rumex sp. in natural conditions show species-specific patterns. The spectrum of N. antartica grown at 38S differs significantly from that of N. antartica in natural conditions in Ushuaia (55S). These results suggest that the selected main area (Patagonia) is appropriate for assessing the problem and its magnitude and that Nothofagus is appropriate for our study.

Algunas reflexiones más sobre una cuestión espinosa: la responsabilidad social de las empresas

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Jean Michel Servais

2010-12-01

Full Text Available En el marco de la Responsabilida Social Empresarial, el autor expone lo que denomina “códigos de conducta” que toda empresa o sociedad privada mantiene; analiza la relación existente entre ellas, además de analizar las actividades que promueven su difusión a nivel internacional tanto por las instituciones y los gobiernos; está principalmente dirigido a los estados miembros de la OIT, que están, urgidos de tomar medidas de ejecución, pero, sirve directamente de referencia para las empresas que redactan su código de conducta o que ponen en marcha otras iniciativas sociales, así como para las sociedades especializadas que definen los criterios que deben respetar las compañías que desean adherirse a su modelo.

Philodryas chamissonis (Reptilia: Squamata: Colubridae preys on the arboreal marsupial Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae Philodryas chamissonis (Reptilia: Squamata: Dipsadidae predando o marsupial arborícola Dromiciops gliroides (Mammalia: Microbiotheria: Microbiotheriidae

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S. Muñoz-Leal

2013-02-01

Full Text Available Philodryas chamissonis, the Chilean long-tailed snake, is a diurnal predator mainly of Liolaemus lizards, but also of amphibians, birds, rodents and juvenile rabbits. Dromiciops gliroides (Colocolo opossum is an arboreal marsupial endemic of temperate rainforest of southern South America. Little information is available about this marsupial's biology and ecology. Here we report the predation of one Colocolo opossum by an adult female P. chamissonis in a mixed Nothofagus forest, composed mainly by N. dombeyi, N. glauca and N. alpina trees, in the "Huemules de Niblinto" National Reserve, Nevados de Chillán, Chile. Since these two species have different activity and habitat use patterns, we discuss how this encounter may have occurred. Although it could just have been an opportunistic event, this finding provides insights into the different components of food chains in forest ecosystems of Chile.Philodryas chamissonis, cobra de cauda comprida ("Culebra de cola larga", é uma cobra diurna, predadora principalmente de lagartos do gênero Liolaemus, mas também de anfíbios, aves, roedores e coelhos jovens. Dromiciops gliroides (colocolo é um marsupial arborícola endêmico das florestas temperadas do sul da América do Sul. Há pouca informação disponível sobre a biologia e a ecologia deste marsulpial. É reportada, neste estudo, a predação de um colocolo por uma fêmea adulta de P. chamissonis, em uma floresta mista de Nothofagus, composta principalmente por árvores N. dombeyi, N. glauca e N. alpina, na Reserva Nacional de Huemules de Niblinto, Nevados de Chillán, Chile. Uma vez que estas duas espécies possuem diferentes padrões de atividade e de uso de habitat, discute-se como este evento poder ter ocorrido. Embora este possa ter sido apenas um evento oportunístico, o achado fornece novas informações sobre os diferentes componentes da cadeia alimentar nos ecossistemas florestais do Chile.

Can native plant species be preserved in an anthropogenic forest landscape dominated by aliens? A case study from Mediterranean Chile

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Steffi Heinrichs

2016-06-01

Full Text Available Plantations with fast growing exotic tree species can negatively affect native plant species diversity and promote the spread of alien species. Mediterranean Chile experienced major landscape changes with a vast expansion of industrial plantations of Pinus radiata in the past. However, with increasing knowledge of biodiversity effects on ecosystem services Chilean forest owners now aim to integrate the conservation of native biodiversity into forest management, but data on native species diversity and establishment within a plantation landscape is scarce. Here we investigated plant species diversity and composition in four forest management options applied within a landscape dominated by P. radiata plantations in comparison to an unmanaged reference: (i a clear cut, (ii a strip cut, (iii a native canopy of Nothofagus glauca and (iv a young P. radiata plantation. We wanted to assess if native plant species can be maintained either by natural regeneration or by planting of native tree species (Nothofagus glauca, N. obliqua, Quillaja saponaria within this landscape. Results show a high diversity of native and forest plant species within the different management options indicating a high potential for native biodiversity restoration within an anthropogenic landscape. In particular, herbaceous species can benefit from management. They are rare in unmanaged natural forests that are characterized by low light conditions and a thick litter layer. Management, however, also promoted a diversity of alien species. The rapid spread of alien grass species after management can deter an initial establishment of native tree species or the survival and growth after planting mainly under dry but less under sufficient moisture conditions. The most unsuccessful option for promoting native plant species was clear cutting in a dry area where alien grasses were abundant. For drought-tolerant tree species such as Quillaja saponaria, though

Recovery of gastrointestinal swine parasites in anaerobic biodigester systems Recuperação de parasitas gastrintestinais de suínos em biodigestores anaeróbicos

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William Alberto Cañon-Franco

2012-09-01

Full Text Available Solid and liquid wastes from livestock operations represent important challenges for animal production regarding their impact in the environment and public health. Parasitological tests performed on 80 samples of affluent and effluent waters from three anaerobic biodigestors with flexible structure from swine farms of Caldas - Colombia, showed the presence of Isospora suis (45%, Eimeria suis (42.5%, E. espinosa (35%, Strongyloides ransomi (28.8%, E. perminuta (12.5%, E. cerdonis (3.8%, and E. porci (2.5%. The additional finding of eggs of Taenia spp. in 10% of the samples was probably caused by a connection between the human sewage system and the biodigester. Although we observed a mean decrease of 65.6% of parasites, these levels were insufficient to meet the minimum requirement set by Engelberg's guidelines regarding water quality. This study demonstrates the serious environmental impact that an inadequately treated animal wastewater represents, and has important implications for water resources and human health.Resíduos sólidos e líquidos oriundos da suinocultura representam desafios importantes para a produção animal no que diz respeito ao impacto do meio ambiente e em saúde pública. Testes parasitológicos foram realizados em 80 amostras de águas afluentes e efluentes de três biodigestores anaeróbicos com estrutura flexível em granjas de Caldas - Colômbia, demonstrando a presença de Isospora suis (45%, Eimeria suis (42,5%, E. espinosa (35%, Strongyloides ransomi (28,8%, E. perminuta (12,5%, E. cerdonis (3,8% e E. porci (2,5%. A constatação adicional de ovos de Taenia spp. em 10% das amostras foi provavelmente causada pela conexão entre o sistema de esgoto humano e o biodigestor. Embora fosse observada uma diminuição média de 65,6% dos parasitas, estes níveis são insuficientes para atender ao requisito mínimo estabelecido pelas diretrizes Engelberg em relação à qualidade da água. Este estudo demonstra o grave

Especies nuevas del género Gibberula (Mollusca: Cystiscidae de Cuba y Venezuela New species of the genus Gibberula (Mollusca: Cystiscidae from Cuba and Venezuela

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José Espinosa

2011-03-01

Full Text Available Se describen 3 especies nuevas de moluscos marinos: Gibberula palmasola sp. n., recolectada en la vegetación asociada a rocas rodeadas de sedimentos blandos en una laguna costera cercada por mangle en la península de Guanahacabibes, Cuba, y caracterizada por presentar, el animal vivo, la cabeza negra y una distribución típica de bandas negras y pardas con lunares anaranjados en el manto bajo la concha; Gibberula dosmosquises sp. n., recolectada en fondos rocosos del Caribe insular de Venezuela, se caracteriza por una discreta coloración del manto y un patrón de manchas en el pie, y Gibberula thetisae sp. n, proveniente de los pastos marinos del golfo de Batabanó, Cuba, con 3 pliegues en la columela, el último muy débil, y un labio externo casi cortante, caracteres que permiten separarla de todas las demás especies conocidas en el área antillana, aunque se desconozca la anatomía del animal. Se discute la lista de especies válidas del género para Cuba y Venezuela, y se hacen adiciones y consideraciones al complejo de especies en torno a Gibberula ubitaensis Espinosa y Ortea, 2000.Three new species of marine molluscs are described. Gibberula palmasola new species, collected in vegetation associated with rocks surrounded by soft sediments in a coastal lagoon surrounded by mangroves in Guanahacabibes Peninsula, Cuba, and characterized by a black head and typical distribution of black and brown bands and orange spots in the mantle. Gibberula dosmosquises new species, collected in rocky bottoms of a Caribbean island from Venezuela, characterized by a simple staining in the mantle and a pattern of spots on the foot, and Gibberula thetisae new species, from sea grass in the gulf of Batabano, Cuba, with shell having 3 columellar folds, the last very weak, and a sharp outer lip; although, its anatomy is not known, these conchological characters separate it from all other known species in the Antilles. Aditionally, the list of valid species

Les recours dilatoires contre les sentences arbitrales devant la Cour d´Appel de Paris. Fabricio Mantilla Espinosa

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Fabricio Mantilla-Espinosa

2010-03-01

Full Text Available En este estudio de derecho francés se puede apreciar claramente cómo; por medio de los recursos interpuestos ante el juez ordinario contra los laudos arbitrales, las partes intentan desconocer o retar­ dar la ejecución  de la decisión proferida  por el tribunal  arbitral para resolver el conflicto que fue sometido a su consideración por disposición misma de las partes. En el derecho colombiano se puede apreciar la misma tendencia. En efecto, tanto nuestra legislación (Ley 23 de 1991, artículo 111, como nuestra jurisprudencia  (por ejemplo, C. E. del 7 de febrero de 2002. C.P. Jesús  María  Carrillo  Ballesteros, Exp.  20467,  le confieren al recurso  de anulación  efecto suspensivo  de la ejecución  lauda arbitral,   lo  cual,  sumado  a  la  inexistencia   de  sanciones eficaces contra los recursos abusivos y a la tendencia de nuestros jueces a desconocer las decisiones tomadas por los tribunales arbitrales, logra privar a la figura del arbitraje de su utilidad práctica. En los sistemas jurídicos  donde se presenta  esta misma  situación se están tomando medidas que permiten  contrarrestar  dicho problema. Sin embargo, nuestro legislador persiste en mantener las mismas soluciones (véase, por ejemplo, las reformas introducidas por el Congreso de la República a los artículos 44 y 45 del proyecto de Ley General de Arbitraje presentado por el gobierno, que van claramente en contra de la finalidad del arbitraje.

Recovery of gastrointestinal swine parasites in anaerobic biodigester systems.

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Cañon-Franco, William Alberto; Henao-Agudelo, Ricardo Andrés; Pérez-Bedoya, José Leandro

2012-01-01

Solid and liquid wastes from livestock operations represent important challenges for animal production regarding their impact in the environment and public health. Parasitological tests performed on 80 samples of affluent and effluent waters from three anaerobic biodigestors with flexible structure from swine farms of Caldas - Colombia, showed the presence of Isospora suis (45%), Eimeria suis (42.5%), E. espinosa (35%), Strongyloides ransomi (28.8%), E. perminuta (12.5%), E. cerdonis (3.8%), and E. porci (2.5%). The additional finding of eggs of Taenia spp. in 10% of the samples was probably caused by a connection between the human sewage system and the biodigester. Although we observed a mean decrease of 65.6% of parasites, these levels were insufficient to meet the minimum requirement set by Engelberg's guidelines regarding water quality. This study demonstrates the serious environmental impact that an inadequately treated animal wastewater represents, and has important implications for water resources and human health.

Influence of Cryogenic Treatments on the Wear Behavior of AISI 420 Martensitic Stainless Steel

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Prieto, G.; Tuckart, W. R.

2017-11-01

The objective of the present work is to characterize the wear behavior of a cryogenically treated low-carbon AISI 420 martensitic stainless steel, by means of ball-on-disk tribological tests. Wear tests were performed under a range of applied normal loads and in two different environments, namely a petrolatum bath and an argon atmosphere. Wear tracks were analyzed by both optical and scanning electron microscopy and Raman spectroscopy to evaluate wear volume, track geometry, surface features and the tribolayers generated after testing. This paper is an extension of the work originally reported in the VIII Iberian Conference of Tribology (Prieto and Tuckart, in: Ballest Jiménez, Rodríguez Espinosa, Serrano Saurín, Pardilla Arias, Olivares Bermúdez (eds) VIII Iberian conference of tribology, Cartagena, 2015). In this study, it has been experimentally demonstrated that cryogenically treated specimens showed a wear resistance improvement ranging from 35 to 90% compared to conventionally treated ones.

Materia strana romanzo scientifico

CERN Document Server

Gómez Cadenas, Juan José

2012-01-01

Nel Laboratorio europeo per la fisica delle particelle, il CERN di Ginevra, sta per vedere la luce uno dei più grandi progressi scientifici di tutti i tempi: la scoperta di un nuovo stato della materia, il cosiddetto "plasma di quark". La direttrice del CERN, Helena Le Guin, teme però che insieme al plasma si stiano formando grumi letali di materia strana, in grado di scatenare una reazione a catena che potrebbe distruggere l'intero pianeta. Mentre Helena cerca disperatamente di far fronte alla crisi, a Ginevra arrivano Irene de Ávila, una giovane e promettente fisica teorica, e il maggiore Héctor Espinosa, un militare americano assegnato alla sede dell'ONU per lavorare a un progetto ultrasegreto legato alla non proliferazione delle armi nucleari: inizia così un'appassionante vicenda in cui convergono rivalità scientifiche, peripezie personali e rischiose operazioni di spionaggio che porteranno i protagonisti fino in Iran.

Riparian leaf litter processing by benthic macroinvertebrates in a woodland stream of central Chile Procesamiento de detritus ripariano por macroinvertebrados bentónicos en un estero boscoso de Chile central

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CLAUDIO VALDOVINOS

2001-06-01

Full Text Available Leaf litter input from riparian landscapes has been identified as both a major energy flow to stream ecosystems and as a food source for stream macroinvertebrates. In riparian landscapes of woodland streams of central Chile, the native deciduous hardwoods are being artificially replaced by exotic coniferous trees at a large spatial scale. It is suggested that this process has a significant impact on the stream communities of central Chile. Today, exotic plantations occur throughout central Chile, with Pinus radiata (D. Don (Monterrey pine accounting for about 80 % of the more than 1,800,000 ha of exotic forests. The objective of this paper was to analyze the effect of the litter beds of a dominant native species (Nothofagus pumilio and an exotic species (P. radiata on the detritus processing carried out by benthic macroinvertebrates, in an experimental catchment of central Chile (Rucúe Creek; 36° 26'00" S, 71° 35'40" W. Results revealed that processing rates of native leaf packs are higher than rates of coniferous leaf packs, suggesting that the replacement of the native hardwoods by exotic coniferous riparian flora has an important impact on the stream energy flow in central Chile. The decay rate coefficients (k were 0.0072 for N. pumilio, and 0.0027 for P. radiata. The greater abundance and biomass of shredders per gram of leaf pack of native Nothofagus would explain the differences in leaf processing rates, especially through the activity of two Plecoptera Gripopterygidae, Limnoperla jaffueli and Antarctoperla michaelseniLa entrada de detritus foliar procedente de áreas riparianas ha sido reconocido como un componente importante en la energética de ecosistemas fluviales y como fuente de alimento de macroinvertebrados acuáticos. En áreas riparianas de esteros boscosos de Chile central los componentes nativos caducifolios están siendo artificialmente reemplazados a gran escala por coníferas exóticas, sugiriendo que este proceso tiene

Miocene Antarctic Terrestrial Realm

Science.gov (United States)

Ashworth, A. C.; Lewis, A.; Marchant, D. R.

2009-12-01

The discovery of several locations in the Transantarctic Mountains that contain macrofossils and pollen is transforming our understanding of late Cenozoic Antarctica. The most southerly location is on the Beardmore Glacier (85.1°S) about 500 km from the South Pole. The environment was an active glacial margin in which plants, insects and freshwater mollusks inhabited the sand and gravel bars and small lakes on an outwash plain. In addition to leaves and wood of dwarf Nothofagus (Southern Beech) shrubs, achenes of Ranunculus (Buttercup), in situ cushion growth forms of mosses and a vascular plant, the assemblages contains various exoskeletal parts of carabid and curculionid beetles and a cyclorrhaphan fly, the shells of freshwater bivalve and gastropod species and a fish tooth. Initially the deposits were assigned a Pliocene age (3.5 Ma) but a mid- to early Miocene age is more probable (c. 14 - 25 Ma) based on correlation of fossil pollen from the deposits with 39Ar/40Ar dated pollen assemblages from the McMurdo Dry Valleys locations. The oldest location within the Dry Valleys also involved an active ice margin but was part of a valley system that was completely deglaciated for intervals long enough for thick paleosols to develop. The Friis Hills fossil deposits of the Taylor Valley region (77.8°S) are at least 19.76 Ma based on the 39Ar/40Ar age of a volcanic ash bed. The valley floor during the non-glacial phases had poorly-drained soils and the extensive development of mossy mires. Wood and leaves of Nothofagus are abundant in lacustrine deposits. The silts of shallow fluvial channels contain abundant megaspores and spiky leaves of the aquatic lycopod Isoetes (Quillwort). Fossils of beetles are also present in these deposits. During the glacial phases, proglacial lakes were surrounded by dwarfed, deciduous Nothofagus shrubs. The youngest fossils recovered from the Dry Valleys are from the Olympus Range (77.5°S) with an age of 14.07 Ma. The environment was an

The early to mid-Miocene environment of Antarctica

Science.gov (United States)

Ashworth, A. C.; Lewis, A.

2012-12-01

Paleoecological studies in the Transantarctic Mountains of the McMurdo region provide evidence that the climate was both warmer and wetter in the early to mid-Miocene than it was during the late Miocene. The climate change was accompanied by a shift from wet- to cold-based glaciation in the TAM and the probable growth of the polar ice sheet. Terrestrial and freshwater aquatic fossil assemblages from the Friis Hills (77°S) and the Olympus Range (77°S), with endpoint 40Ar/39Ar ages on tephras of 19.76 Ma and 14.07 Ma, respectively, indicate climatic cooling during the interval. At c.14 Ma, the temperature dropped below the threshold required to support the plants and insects of a tundra biome, and they became extinct. This interpretation is supported by pollen studies from Ross Sea cores. The extinction of the tundra biota on the continent appears to have been time-transgressive, occurring at 12.8 Ma on the Antarctic Peninsula. Evidence of climatic cooling from early to mid-Miocene is based on a decrease in biodiversity. During interglacial phases of the early Miocene, the poorly drained valley of the Friis Hills supported a sexually-reproducing moss community dominated by Campylium cf. polygamum, which today grows on the margins of lakes and in soil between boulders. Wood and leaves of Nothofagus (Southern Beech), and the seeds of at least five other angiosperm species are preserved as fossils. In addition, there are abundant megaspores and spiny, curved leaves of the aquatic lycopod Isoetes (Quillwort), as well as chitinous remains of curculionid beetles and Chironomidae (midges). During glacial phases, the only fossils found are Nothofagus leaves of a species which appears to be different than that associated with the interglacial phases. Pollen supports the interpretation that there was more than one species of Nothofagus in the vegetation. The types and numbers of species indicate that the vegetation was a shrub tundra. The closest modern analog for the fossil

A new species of Alsodes (Anura: Alsodidae) from Altos de Cantillana, central Chile.

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Charrier, Andrés; Correa, Claudio; Castro, Camila; Méndez, Marco A

2015-02-05

Based on morphological and molecular evidence (mitochondrial and nuclear sequences) we describe a new species of spiny-chest frog, Alsodes cantillanensis, from central Chile (around 34°S). The type locality, Quebrada Infiernillo, is located in the Coastal Range at approximately 65 km from Santiago (Metropolitan Region), the capital of Chile. The distribution of the new species is included entirely in that of A. nodosus (32-36°S approximately), which was identified as the sister taxon according to molecular phylogenetic analyses. Moreover, both species are sympatric in the type locality. The new species was found in a Nothofagus macrocarpa relict forest potentially threatened by gold mining activities. We identify other threats for its conservation and some biological data needed for understanding the evolution of this species. This discovery reveals the scarce knowledge about biogeography, evolution and ecology of spiny-chest frogs from central Chile. 

A new species of Rhytidognathus (Carabidae, Migadopini) from Argentina.

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Roig-Juñent, Sergio; Rouaux, Julia

2012-01-01

The Migadopini are a small tribe of Carabidae with 47 species that occur in South America, Australia, and New Zealand, in the sub-Antarctic areas. In South America, most of the genera inhabit areas related to sub-Antartic Nothofagus forest except two monogeneric genera, the Ecuadorian genus Aquilex Moret and the Pampean genus Rhytidognathus Chaudoir. These two genera are geographically isolated from the remaining five South American genera. New material of Rhytidognathus from the northeast of Buenos Aires province and from Entre Ríos province permits establishing that the previous records of Rhytidognathus ovalis (Dejean) for Argentina were erroneous and that it belongs to a new species. Based on external morphological characters and from male and female genitalia we describe Rhytidognathus platensis as a new species. In this contribution we provide illustrations, keys, habitat characteristics and some biogeographic considerations on the distribution of Rhytidognathus.

A new species of Rhytidognathus (Carabidae, Migadopini from Argentina

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Sergio Roig-Junent

2012-11-01

Full Text Available The Migadopini are a small tribe of Carabidae with 47 species that occur in South America, Australia, and New Zealand, in the sub-Antarctic areas. In South America, most of the genera inhabit areas related to sub-Antartic Nothofagus forest except two monogeneric genera, the Ecuadorian genus Aquilex Moret and the Pampean genus Rhytidognathus Chaudoir. These two genera are geographically isolated from the remaining five South American genera. New material of Rhytidognathus from the northeast of Buenos Aires province and from Entre Ríos province permits establishing that the previous records of Rhytidognathus ovalis (Dejean for Argentina were erroneous and that it belongs to a new species. Based on external morphological characters and from male and female genitalia we describe Rhytidognathus platensis as a new species. In this contribution we provide illustrations, keys, habitat characteristics and some biogeographic considerations on the distribution of Rhytidognathus.

Present Status of Historical Seismicity Studies in Colombia and Venezuela

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Sarabia, A.; Cifuentes, H.; Altez Ortega, R.; Palme, C.; Dimate, C.

2013-05-01

After the publication of the SISRA (CERESIS-1985) regional project, a unified catalog of seismic parameters and intensities for South America, researchers in historical seismicity have continued advancing on different scales in the area of this study of seismic hazard. The most important initiatives carried out in this area in Colombia and Venezuela can be grouped as follows: a) Reviews of destructive earthquakes in national and international historic archives, principally by Altez and FUNVISIS in Venezuela and Espinosa, Salcedo, and Sarabia et al in Colombia, leading to the preparation of seismologic catalogues, scientific and dissemination articles, reports, books, among others. b) Organization and systematization of historic information to develop public domain data bases and information, specifically the Historic Seismologic Teleinformation System in Venezuela, carried out between 2004 and 2008 under the coordination of Christl Palme and accessible on-line: http://sismicidad.ciens.ula.ve. As well, the "Historia Sísmica de Colombia 1550-1830" (Seismic History in Colombia 1550-1830) data base, in CD-ROM, by Espinosa Baquero (2003) and the historic seismicity information system of Colombia (Servicio Geológico Colombiano-Universidad Nacional de Colombia), published on the internet in 2012: http://agata.ingeominas.gov.co:9090/SismicidadHistorica/. c) Macroseismic studies for the development of intensity attenuation equations and the quantification and revaluation of basic historic earthquake parameters using isoseismal maps (Rengifo et al., Palme et al., Salcedo et al., among others) and procedures such as Boxer and Bakun & Wentworth (Palme et al., Dimaté, among others), which have produced significant changes in the parameters of some of the large earthquakes. d) Symposiums of researchers to promote interest and development in the discipline, including Jornadas Venezolanas de Sismología Histórica (Venezuelan Congress of Historical Seismology), held

Entre el mito Bátavo y el mito de Venecia: identidad nacional y republicanismo en la Holanda de Espinosa

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Martínez, Francisco José

2005-12-01

Full Text Available The present paper opposes two ways of legitimizing the political systems: the appeal to the history and to the national identity and to emphasize the institutional mechanisms. For it centres on the Holland of the XVIIth century where they face the batavian myth and the myth of Venice; the first one reconstructs a mythical history that carries the love of the Dutches back to the freedom to the time of the revolt of the batavians against the Roman empire; the second one emphasizes in the institutional mechanisms that assured to the republic of Venice her maintenance in the time: asuitable scale of power, systems of voting secretes; etc. It ends up by being argued in favour of the second procedure, for his major rationality and capacity of adjustment opposite to the historical - mythical justifications of difficult control and scanty flexibility for the negotiation.

El presente trabajo contrapone dos formas de legitimar los sistemas políticos: la apelación a la historia y a la identidad nacional y el destacar los mecanismos institucionales. Para ello se centra en la Holanda del siglo XVII donde se enfrentan el mito bátavo y el mito de Venecia; el primero reconstruye una historia mítica que retrotrae el amor de los holandeses a la libertad al tiempo de la sublevación de los bátavos contra el imperio romano; el segundo hace hincapié en los mecanismos institucionales que aseguraron a la república de Venecia su perduración en el tiempo: una balanza adecuada de poderes, sistemas de votación secreta; etc. Se concluye argumentando a favor del segundo procedimiento, por su mayor racionalidad y capacidad de adaptación frente a las justificaciones histórico-míticas de difícil control y escasa flexibilidad para la negociación.

The taphonomy of a remarkable leaf bed assemblage from the Late Oligocene-Early Miocene Gore Lignite Measures, southern New Zealand

Energy Technology Data Exchange (ETDEWEB)

Ferguson, David K.; Zetter, Reinhard; Vavra, Norbert [Department of Paleontology, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria); Lee, Daphne E. [Department of Geology, University of Otago, PO Box 56, Dunedin (New Zealand); Bannister, Jennifer M. [Department of Botany, University of Otago, PO Box 56, Dunedin (New Zealand); Jordan, Gregory J. [School of Plant Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001 (Australia); Mildenhall, Dallas C. [GNS Science, PO Box 30-368, Lower Hutt (New Zealand)

2010-08-01

A diverse assemblage of fossil leaves showing cellular detail is reported from the Late Oligocene-Early Miocene Gore Lignite Measures, southern New Zealand. The leaf-remains include at least five conifers, such as the genera Agathis, Dacrycarpus, Phyllocladus and Dacrydium, as well as a number of angiosperms including Gymnostoma, Nothofagus Subgenus Brassospora, Phormium, Proteaceae, Sapindaceae and Ericaceae. A parallel palynological study has identified a number of the same elements. The leaf layers represent litter horizons laid down in pools on the surface of a subtropical ombrotrophic forest mire that formed on an extensive low-lying coastal plain. Highly acidic water ponded in tree-fall depressions prevented microbial decay of the foliage. Taxa represented by both leaves and pollen are considered to have been components of the autochthonous swamp forest. Some other pollen grains are thought to represent local elements, based on the pollination biology of their nearest living relatives. Other taxa whose extant representatives are wind-pollinated may have grown further away. (author)

Preliminary results of the first paleontologic investigations in Uruguayan Antarctica

International Nuclear Information System (INIS)

Perea, D.; Masquelin, E.; Verde, M.; Querequiz, R.

1998-01-01

Preliminary results of the first Uruguayan paleontollogic and biostratigraphical investigations in Antartica are presented. The field work was performed in fildes Peninsula, King George Island, near Uruguayan station Base Cientifica Antarctica Artigas.Some fossiliferous outcrops were geologic and paleontologically analyzed, among them Fossil Hills, situated in the center part of the peninsula, in front of Ardley Island, between the chinese and chilean stations.This hill is composed of fossil bearing piroclastic and epiclastic rocks, assigned to the fossil Hill Fm. Vegetal remains(petrified wood and leaf impronts) were observed and collected in this unit and it is remarkable the presence of Nothofagus sp. and invertebrate trace fossils, Cochlichmus isp and Helminthopsis isp.The depositional environment deduced from the fossil association in lacustrine, under a warm and humid climate.In the same deposits, other investigators have collected aquatic and ratite bird trace fossils. Paleontologic evidence is not contradictory with the Eocene age previously proposed for the studied deposits. (author)

Decoupling of unpolluted temperate forests from rock nutrient sources revealed by natural 87Sr/86Sr and 84Sr tracer addition

Science.gov (United States)

Kennedy, Martin J.; Hedin, Lars O.; Derry, Louis A.

2002-01-01

An experimental tracer addition of 84Sr to an unpolluted temperate forest site in southern Chile, as well as the natural variation of 87Sr/86Sr within plants and soils, indicates that mechanisms in shallow soil organic horizons are of key importance for retaining and recycling atmospheric cation inputs at scales of decades or less. The dominant tree species Nothofagus nitida feeds nearly exclusively (>90%) on cations of atmospheric origin, despite strong variations in tree size and location in the forest landscape. Our results illustrate that (i) unpolluted temperate forests can become nutritionally decoupled from deeper weathering processes, virtually functioning as atmospherically fed ecosystems, and (ii) base cation turnover times are considerably more rapid than previously recognized in the plant available pool of soil. These results challenge the prevalent paradigm that plants largely feed on rock-derived cations and have important implications for understanding sensitivity of forests to air pollution. PMID:12119394

Una nueva aportación al catálogo del pintor Vicente Alanís.

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Álvaro Cabezas García

2016-01-01

Full Text Available Recientemente pude estudiar con detenimiento la pintura que remata el retablo de ánimas ubicado en la nave del Evangelio de la iglesia de San Juan de la Palma de Sevilla. Se trata de una pieza de mediano tamaño, ejecutada con la técnica del óleo sobre lienzo, que presenta actualmente un estado de conservación muy deficiente –en la fotografía pueden apreciarse tres roturas en la tela, siendo una de ellas de considerables proporciones–, y que representa a San Lorenzo Mártir con sus atributos característicos. Por las amplias similitudes que presenta su forma considero justificado incluirla en el catálogo pictórico de Vicente Alanís Espinosa. A este autor he dedicado parte de mis estudios, pero, como es habitual en tantos artistas, la investigación científica sigue ofreciendo caminos de exploración que hacen posible proponer nuevas aportaciones a la nómina de las pinturas ya conocidas.

Alegrias e tristezas no cotidiano de trabalho do agente comunitário de saúde: cenários de paixões e afetamentos

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Heletícia Scabelo Galavote

2013-09-01

Full Text Available O estudo busca desvendar o processo de trabalho do agente comunitário de saúde (ACS com base na teoria das afecções de Espinosa. Considera o encontro como uma unidade de análise, e pretende compreendê-lo na sua dinâmica de produção do cuidado, analisando as afecções que se expressam por alegrias e tristezas e os seus efeitos no trabalho do ACS. Trata-se de estudo exploratório-descritivo, de caráter qualitativo, realizado na Unidade Jardim Catarina, São Gonçalo, Rio de Janeiro, Brasil. Os dados foram coletados em entrevista com dez ACS's, por meio de roteiro semiestruturado e observação etnográfica. O estudo revela um ACS múltiplo, exposto às afecções das relações que mantém, variando entre o reconhecimento e a submissão às lógicas instituídas, resultando em alegria e tristeza, aumento e redução da sua potência de agir, respectivamente.

Fernando vallejo: y la clausura ciudadanía estética de la literatura mundial

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Brantley Nicholson

2011-09-01

Full Text Available Este artículo encara deliberaciones actuales sobre la literatura global, desde la perspectiva de la novela urbana colombiana del siglo XX. Explorando la tensión entre las historias de las narrativas globales y locales, el autor examina hasta qué punto se puede defender que la literatura global y sus apéndices socioculturales se prestan a proyectos emancipatorios, y hasta qué punto esos apéndices simplifican en exceso los espacios de producción literaria densa. Ubicando la Weltliteratur de Goethe en el contexto de una Colombia estéticamente globalizada, e invocando la relación particularmente espinosa entre Fernando Vallejo y Gabriel García Márquez como caso de estudio, este artículo avanza que las casas editoriales internacionales y las culturas de la crítica crean una ciudadanía estética limitante que sigue siendo dominada por las decisiones de mercadeo de las grandes casas editoriales y el gusto de los públicos lectores, muy alejados del contexto de los bestsellers “periféricos”.

Retórica de la historia. Un desafío al exceso de las nuevas tecnologías.

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Pedro Javier Gómez Martínez

2013-01-01

Full Text Available El presente artículo se propone analizar un cierto tipo de figuras retóricas que se da en la obra audiovisual en el nivel de la propia historia, afectando al plano del contenido antes que al de la expresión. Hemos utilizado como caso de estudio la serie televisiva Pulseres vermelles ("Pulseras rojas", 2011, creada por Albert Espinosa y dirigida por Pau Freixas. El formato ha sido exportado más allá de nuestras fronteras. Steven Spielberg ha adquirido los derechos. Con un apreciable éxito de público y crítica, esta serie ha conquistado el corazón de numerosos espectadores a partir de temáticas emocionales de enorme compromiso, valiéndose además de un aparato retórico muy eficaz, parte del cual analizaremos aquí. Dichas circunstancias inducen a reflexionar sobre la importancia de la historia frente al discurso. Defendemos que la serie da prioridad a una retórica del contenido sobre la retórica de la expresión.

Eficiencia pesquera de la Nasa Amigable, en las capturas artesanales de langosta espinosa (P. argus en los Cayos Miskitus1

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Jadder Mendoza-Lewis

2012-02-01

Full Text Available La pesquería de langosta (Panulirus argus en el caribe nicaragüense se encuentra en estado de depresión consecuencia de la incidencia de la mortalidad por pesca, principalmente por las altas capturas de organismos juveniles, por debajo de las tallas permitidas por la legislación nacional; ante este efecto negativo para la sobre vivencia del recursos y el rendimiento sostenible pesquero, se han impulsado diversos esfuerzos de protecciónbiológica del recurso que van desde el establecimiento de tallas mínimas comerciales (Longitud mínima de cola de 140 mm y/o peso mínimo de cola de 5 onzas ó 140 gramos y la veda temporal de capturas entre el 1 de abril y el 30 de junio; así también se ha promovido la prohibición de la pesca por buceo, la cual haresultado de escasa aceptación por el rol económico de esta estrategia en la economía regional que genera empleo directo para más de 3000 buzos e igual número de cayuqueros.Ante esta situación del recurso langosta del caribe (P. argus la Universidad de las Regiones Autónomas de la Costa Caribe Nicaragüense (URACCAN y el Fondo Mundial para la Naturaleza (WWF promueven la pesca sostenible en la Reserva Biológica Marina de los Cayos Miskitus, sitio estratégico para la biologíadel recurso mencionado y el desarrollo de la pesca artesanal, para lo cual se impulsa las capturas con nasas (trampas que propicien la reducción de capturas de organismos con dimensiones por debajo de los parámetros pesqueros establecidos por laautoridad pesquera de Nicaragua.

Prática educativa bem-sucedida na escola: reflexões com base em L. S. Vigotski e Baruch de Espinosa

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ELIANA DE SOUSA ALENCAR MARQUES

2017-01-01

Full Text Available El texto reúne parte de los resultados de las investigaciones llevadas a cabo con el fin de investigar las mediaciones constitutivas de los profesores y estudiantes que desarrollan con éxito las prácticas educativas. El signifi - cado de la práctica educativa exitosa en la que nos basamos está anclado en las ideas de L. S. Vygotsky y Baruch Spinoza. Con base en los teóricos, entendemos prácticas educativas exitosas las que generan aprendizaje y desarrollo y permiten la expansión de afectos alegres que mejoran mentes y cuerpos humanos. La investigación tuvo lugar entre los años 2011 y 2014. Esto artículo presenta parte de los resultados alcanzados con los alumnos. Los resultados mostraron que, cuando alegres, las experiencias educativas convergen a la mayor potencia de ser un estudiante. El aumento de potencia reorienta la producción de nuevos sentidos que alteran significativamente la relación de estos con los estudios, con la escuela y con la vida.

Dendroecological analysis of a Fitzroya cupressoides and a Nothofagus nitida stand in the Cordillera Pelada, Chile

Science.gov (United States)

Margaret S. Devall; Bernard R. Parresol; Juan J. Armesto

1998-01-01

Lumbering of Fitzroya cupressoides in Chile began in 1599 and continued until 1976, when the species was declared a national monument and cutting of live trees was prohibited. Today, F. cupressoides is threatened; many of the remaining stands in the coastal range appear to be declining, with a predominance of standing dead stems and patchy, sparse regeneration. The...

Selection of Entomopathogenic Nematodes against Dalaca pallens (Lepidoptera: Hepialidae Selección de Nematodos Entomopatógenos para el Control de Dalaca pallens (Lepidóptera: Hepialidae

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Alexis Maldonado

2012-06-01

Full Text Available Dalaca pallens (Blanchard is a pest with great impact on grassland production in Chile. The objective of this research was to evaluate the use of entomopathogenic nematodes (EPN against D. pallens larvae. Twenty EPN isolates, collected along Chile, were used for nematode selection. The experimental unit consisted of five 50-mL plastic vials filled with Nothofagus dombeyi sawdust and inoculated with 40 dauers per vial. The experimental design was a completely randomized with four replicates per treatment. The results showed that isolate QU N3 (Steinernema australe and QU N13 (Steinernema unicornum produced the highest mortality, with 100 and 95% respectively and no differences (P Dalaca pallens (Blanchard es considerada una de las plagas de mayor incidencia para la producción de las praderas en Chile. El objetivo de esta investigación fue la selección de aislamientos nativos de nematodos entomopatógenos (EPN para el control de larvas de D. pallens. Se utilizaron 20 aislamientos nativos de EPN, para cada uno se inocularon 40 dauers por frascos cónicos con aserrin de Nothofagus dombeyi, y se agregó una larva de D. pallens de cuarto instar. Luego, se incubaron a 15 °C y oscuridad y se registró la mortalidad diaria. Se realizaron cuatro repeticiones por tratamiento y la unidad experimental fue de cinco frascos. Los resultados mostraron que el aislamiento QU N3 de Steinernema australe alcanzó el 100% de mortalidad a los 15 días de incubación, sin mostrar diferencias (P < 0,001 con el tratamiento QU N13 (Steinernema unicornum, el cual alcanzó un 95%. Para el cálculo de la concentración letal (CL50 y CL90 se usaron los dos aislamientos mencionados, y se evaluaron concentraciones de 0, 10, 20, 30, 40 y 50 dauers por frasco que contenian una larva de D. pallens de cuarto instar. Para el aislamiento QU N3 la CL50 y CL90 fue de 14 y 39 dauers mL-1, a los 13 d de incubación, mientras que para QU N13 estos valores fueron de 14 y 48 dauers mL-1

Screening and management of gestational diabetes in Mexico: results from a survey of multilocation, multi-health care institution practitioners

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Dainelli L

2018-04-01

Full Text Available Livia Dainelli,1 Alberto Prieto-Patron,1 Irma Silva-Zolezzi,1 Sandra G Sosa-Rubi,2 Salvador Espino y Sosa,3 Enrique Reyes-Muñoz,4 Ruy Lopez-Ridaura,5 Patrick Detzel1 1Nestlé Research Center, Lausanne, Switzerland; 2Health Economics Department, National Institute of Public Health, Cuernavaca, Morelos, Mexico; 3Clinical Research Branch, National Institute of Perinatology Isidro Espinosa de los Reyes, Mexico City, CDMX, Mexico; 4Endocrinology Department, National Institute of Perinatology Isidro Espinosa de los Reyes, Mexico City, CDMX, Mexico; 5Center for Research on Population Health, National Institute of Public Health, Cuernavaca, Morelos, Mexico Purpose: To identify the most common practices implemented for the screening and treatment of gestational diabetes mellitus (GDM and to estimate the GDM clinician-reported proportion as a proxy of the incidence in Mexico. Materials and methods: Three hundred fifty-seven physicians in four major cities were asked about their practices regarding GDM screening, treatment, clinical exams, and health care staff involved in case of GDM diagnosis, as well as the percentage of women with GDM they care for. Data management and statistical analyses were done with Stata 13. Results: The overall GDM clinician-reported proportion was 23.7%. Regional differences were expected and consistent with the data on the epidemiology of the obesity in the country. The most common screening test was the oral glucose tolerance test 75 g one step (46.6% of total cases. Diet and exercise were sufficient to treat GDM in 40.6% of cases; the rest of the sample relied on some form of medication, especially oral hypoglycemic agents (63.0% of cases, insulin (22.0%, or a combination of these (13.0%. To educate women on how to measure glycemia and eventually take medications, an average of 2–3 hours were necessary. The three most common prenatal screening tests were the “no stress”, the “Doppler ultrasound”, and the �

Knowing and doing: research leading to action in the conservation of forest genetic diversity of Patagonian temperate forests.

Science.gov (United States)

Gallo, Leonardo A; Marchelli, Paula; Chauchard, Luis; Peñalba, Marcelo Gonzalez

2009-08-01

Researchers dealing with conservation subjects usually do not put the results of their work into practice, even when the primary purpose of their research is the preservation of biodiversity. In the South American temperate forests we identified an area with the highest genetic diversity in Argentina of Nothofagus nervosa, one of the most relevant southern beech species. Based on the information of our scientific study and our recommendations, the authorities of Lanin National Park changed the protection status of this area to avoid logging. The new forestry management plans include consideration of "high genetic diversity" in decisions on where logging will be allowed. Results of our initial genetic study induced the analysis of biodiversity at the species and ecosystems levels, which yielded results similar to our genetic studies. A strong connection among researchers and managers from the onset of our study and the awareness of the former about the importance of the implementation of the research work were key to bridging the gap between conservation research and conservation practice.

Long-term monitoring of thinning for silvopastoral purposes in Nothofagus antarctica forests of Tierra del Fuego, Argentina

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Guillermo Martínez Pastur

2018-05-01

Research highlights: Monitoring of thinning for silvopastoral management must include easy and cheap measuring variables, e.g. diameter growth as a proxy for timber production objectives and hemispherical photos (crown cover and radiation as a proxy for pasture production. Long-term monitoring allowed to identify reliable indicators that assist new sustainable management alternatives.

Nucleus-size pinning for determination of nucleation free-energy barriers and nucleus geometry

Science.gov (United States)

Sharma, Abhishek K.; Escobedo, Fernando A.

2018-05-01

Classical Nucleation Theory (CNT) has recently been used in conjunction with a seeding approach to simulate nucleation phenomena at small-to-moderate supersaturation conditions when large free-energy barriers ensue. In this study, the conventional seeding approach [J. R. Espinosa et al., J. Chem. Phys. 144, 034501 (2016)] is improved by a novel, more robust method to estimate nucleation barriers. Inspired by the interfacial pinning approach [U. R. Pedersen, J. Chem. Phys. 139, 104102 (2013)] used before to determine conditions where two phases coexist, the seed of the incipient phase is pinned to a preselected size to iteratively drive the system toward the conditions where the seed becomes a critical nucleus. The proposed technique is first validated by estimating the critical nucleation conditions for the disorder-to-order transition in hard spheres and then applied to simulate and characterize the highly non-trivial (prolate) morphology of the critical crystal nucleus in hard gyrobifastigia. A generalization of CNT is used to account for nucleus asphericity and predict nucleation free-energy barriers for gyrobifastigia. These predictions of nuclei shape and barriers are validated by independent umbrella sampling calculations.

Um Inimigo do Povo: o Livre-Pensador e o Suicídio

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Ulisses Razzante Vaccari

Full Text Available RESUMO: Partindo de uma leitura da peça Um inimigo do povo, de Ibsen, o presente texto procurará definir o livre-pensador como aquele que se opõe ao pensamento ou aos pensamentos dominantes, ousando pensar por si próprio. Ao fazê-lo, o livre-pensador se sacrifica, cometendo uma espécie de suicídio (material e moral, proveniente de seu amor incondicional pela sua comunidade. A partir da definição de Ibsen, o artigo procurará alguns exemplos na história do pensamento que a corroborem, como Sócrates, Galileu e Espinosa. No caso da arte, o texto tecerá algumas considerações acerca da transposição dessa condição do livre-pensador para o teatro, como acontece com o Galileu, de Brecht, e A morte de Empédocles, de Hölderlin. Ao final do texto, pretende-se mostrar que também Nietzsche possui uma concepção a respeito do livre-pensador, o qual deve se tornar atemporal e póstumo.

Levaduras fermentadoras aisladas de Cyttaria hariotii (Fungi en bosques Andino-Patagónicos (Argentina Fermenting yeasts isolated from Cyttaria hariotii (Fungi in the Andean Patagonic Forest

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José Ulloa

2009-12-01

Full Text Available Las levaduras han estado asociadas al hombre desde épocas muy tempranas. Entre estas se destacan las fermentadoras debido a su importancia en la industria de los alimentos. Las implicancias biotecnológicas de estas levaduras han sido extensamente estudiadas, sin embargo la distribución en la naturaleza y la ecología de estas no se encuentra igualmente documentada. El presente estudio se realizó en el Parque Nacional Nahuel Huapi (Noroeste Patagónico, Argentina sobre Cyttaria hariotii, hongo ascomicético parásito de árboles del género Nothofagus. Mediante el uso de un medio selectivo con etanol 8 % se obtuvieron 72 aislamientos. Los mismos fueron ordenados en cinco grupos en base a pruebas morfológicas y fisiológicas, tres de los cuales fueron asignados a los géneros Saccharomyces, Pichia y Kloeckera. El grupo Saccharomyces presentó el mayor número de aislamientos y se subdividió en tres subgrupos, dos de ellos presentan alta afinidad con S. bayanus y/ó S. uvarum. La totalidad de los aislamientos fueron psicrotolerantes y la temperatura máxima de crecimiento osciló entre 35 y 37 _C. El presente trabajo contribuye al conocimiento de la biodiversidad de levaduras de la Patagonia y representa el primer aislamiento masivo de levaduras sacaromicéticas en ambientes naturales de la región.Yeasts have been associated with mankind from early ages. Among these, fermentative yeasts played the most relevant role, due to its importance in the food industry. The biotechnological implications of these yeasts have been extensively studied. However there is a lack of information about its distribution in nature and ecology. In this study samples of Cyttaria hariotii, ascomycete fungus parasite of trees of the genus Nothofagus, were collected in Nahuel Huapi National Park (Northwestern Patagonia, Argentina. 72 isolates were obtained using a selective culture medium with 8% ethanol. Identification of the isolates was based on morphological and

Restos lignocelulósicos de gran tamaño (necromasa en un bosque templado de antiguo crecimiento del sur de Chile

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Carlos Belezaca Pinargote

2015-11-01

Full Text Available Los restos lignocelulósicos de gran tamaño (RLC, constituyen la necromasa en ambientes boscosos, y cumplen variadas funciones ecosistémicas. Se evaluó el volumen, necromasa, y estados de descomposición de RLC muertos, en un bosque templado de antiguo crecimiento (BTAC dentro del Parque Nacional Puyehue, Centro-Sur de Chile. En 10 parcelas de 900 m2, se cuantificó los RLC (≥ 10 cmϕ, cuya necromasa se clasificó empleando una escala de cinco categorías/estados de descomposición (1= menor degradación y 5= mayor degradación. Se encontró 632 m3 ha-1 de madera muerta (= 231,5 Mg ha-1 de necromasa, representados principalmente por Nothofagus betuloides (95,2%, siendo los troncos (52,7%y ramas (35%, las estructuras vegetales más representativas (554,3 m3 ha-1≈ 203 Mg h-1. Estos resultados demuestran que los BTAC del sur de Chile son importantes reservas de litera leñosa gruesa, que contribuye a la biogeoquímica de estos complejos y remotos ecosistemas.

Hibridación social: un modelo conceptual para el análisis de la región y el territorio

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Sergio A. Sandoval Godoy

2003-01-01

Full Text Available A partir de un estudio sobre la población en el centro del país en el que se emplearon las escalas de bienestar subjetivo (Anguas,1997, auto concepto (La Rosa, 1986, locus de control (La Rosa, Díaz y Andrade, 1986, orientación al logro (Díaz, Andrade y La Rosa, 1989, evitación al éxito (Espinosa y Reyes, 1991 y enfrentamiento a lo problemas (Góngora, 1998, se procedió a investigar su validez y las diferencias por género, edad y educación en el estado de Sonora. Mediante un muestreo por cuota, edad, sexo y socialización, se seleccionaron 1000 personas pertenecientes a cinco grupos de edad: adolescentes (14-18, adolescentes tardíos (19-22, jóvenes adultos (23-30, adultos (31-38 y adultos tardíos (39-55. Los resultados evidenciaron la sensibilidad y precisión de las escalas, así como diferencias por grupo de edad, sexo, ocupación y escolaridad . Finalmente, se reafirma el papel que juega el bienestar subjetivo en la percepción de control y en los estilos de enfrentamiento que la persona manifiesta en las distintas situaciones o escenarios en los que participa.

Estructura del quiste hidatídico producido por Echinococcus oligarthrus en el hospedero intermediario Proechimys c.f. guairae (rata espinosa) en Casanare, Colombia

OpenAIRE

Gerzain Rodríguez; Margarita Tamayo; Jorge Boshell

2000-01-01

La equinococosis es un parasitismo grave producido en el hombre y en los animales por larvas de tenias del género Echinococcus que se desarrollan en el higado, el pulmón, el bazo y en otras visceras y tejidos. De las cuatro tenias dei género Echinococcus, tres se presentan en Suramerica: E granulosus, E. vogeli y E. oligarihrus. En Colombia se han informado casos en humanos y en animales cuyo agente etiológico más frecuente es E. vogeli. En este trabajo presentamos la estructura macroscópica,...

Palynostratigraphy and paleoenvironments of Wellington, New Zealand, during the last 80 ka, based on palynology of drillholes

International Nuclear Information System (INIS)

Mildenhall, D.C.

1994-01-01

About 20 pollen profiles from the Wellington area are correlated and zoned according to their pollen characteristics. Sequences from many of the larger sedimentary deposits are shown to contain little or no sediment of late Last Glacial and early Postglacial age, while late Postglacial sedimentation is restricted to a few localities. Sediments of middle and early Last Glacial age are well represented and widespread over the Wellington area. Pollen diagrams from Last Glacial and Postglacial sediments are zoned as follows: Zone A, 80,000-60,000 yr B.P. (lower end of range more likely) and provisionally correlated with oxygen isotope stages 5a and basal 4; Zone B, 70,000-50,000 yr B.P. (lower end of range more likely), provisionally correlated with upper oxygen isotope stages 4 and basal stage 3; Zone C, a short zone just beyond the range of radiocarbon dating at the top of Zone B of 60,000-50,000 yr B.P., correlated with the middle of oxygen isotope stage 3; Zone D, 50,000-10,000 yr B.P., with a major period of nondeposition or erosion between c. 18,000 and 10,000 yr B.P., correlated with the upper part of oxygen isotope stages 3 and all of 2; Zone E, 10,000-1000 yr B.P. (Postglacial); Zone F, last 1000 years (human occupation zone). During this time the vegetation changed from a beech forest (Zone A1) to a shrub/grassland, with pollen from the dominant tree taxa being Nothofagus fusca type (Zone A2), N. menziesii with Phyllocladus (Zones B, C), Phyllocladus with N. menziesii (Zone D), Dacrydium cupressinum (Zone E), and Nothofagus fusca with D. cupressinum (Zone F). Climatic conditions during the Last Glaciation were generally colder, drier, and stormier relative to the present day. The virtual absence of sediment of this age suggests widespread nondeposition or erosion under unstable conditions. Zones B-D represent the harshest conditions, with temperatures averaging up to 5 degrees C less than the present day. Basal Postglacial conditions were the reverse, with

Reseñas de libros

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Alfonso Galindo Lucas

2009-03-01

Full Text Available Ali, Tariq, Bush en Babilonia. La recolonización de Irak. Madrid, Alianza Editorial, 2004, 286 pp.Páginas 183-185Alfonso Galindo LucasÁlvarez Espinosa, Daniel, Cristianos y marxistas contra Franco. Cádiz, Servicio de Publicaciones de la Universidad de Cádiz, 2003, 454 pp.Páginas 185-187Gonzalo Ruiz BidónBonhoeffer, Dietrich, Resistencia y sumisión. Cartas y apuntes desde el cautiverio. Salamanca, Sígueme, 2003, 300 pp.Páginas 187-188Daniel Francisco Álvarez EspinosaCabrera, Miguel Ángel, Historia, Lenguaje y Teoría de la Sociedad. Madrid, Cátedra Universitat de Valencia, 2001, 188 pp.Páginas 188-191Alejandro Estrella GonzálezCobo Romero, Francisco, De campesinos a electores. Modernización agraria en Andalucía, politización campesina y derechización de los pequeños propietarios y arrendatarios. El caso de la provincia de Jaén, 1931-1936. Madrid, B. Nueva, 2003, 358 pp.Páginas 191-193David Molina RabadánColomer Viadel, Antonio, Crisis y Reformas en Iberoamérica ¿... y la Revolución? Valencia, Editorial Nomos, 2002, 231 pp.Páginas 193-196Jesús Fernández GarcíaCué, Carlos E., ¡Pásalo!: Los cuatro días de marzo que cambiaron el país. Barcelona, Ediciones Península Atalaya, 2004, 143 pp.Páginas 196-198Inmaculada Ramírez PérezCuenca Toribio, José Manuel, Catolicismo social y político en la España contemporánea (1870-2000. Madrid, Unión Editorial, 2003, 451 pp.Páginas 198-200Fernando López MoraKagan, Robert, Poder y debilidad. Europa y EEUU en el nuevo orden mundial. Madrid, Taurus, 2003, 165 pp.Páginas 201-202David Molina RabadánNapoleoni, Loretta, Yihad. Cómo se financia el terrorismo en la nueva economía. Barcelona, Ediciones Urano, 2004, 462 pp.Páginas 202-204Andrés Herrera FeligrerasPaksoy, H.B., How Governed, Who Pays? Lawrence (KS, Carrie, 2001, 79 pp.Páginas 204-206Dan KrejciReinares, Fernando, Terrorismo Global. Madrid, Taurus, 2003, 180 pp.Páginas 206-208Marcela Iglesias OnofrioSala Rose

Límites del dialecto leonés en la provincia de Zamora según los materiales del Cuaderno I del ALPI (1934-1935

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González Ferrero, Juan Carlos

2007-12-01

Full Text Available The validity of the isoglosses by which the boundaries of the Leonese dialect in the province of Zamora have been traditionally indicated, especially as a way of identifying the area where this dialect was spoken in the early 20th century, has always been held in doubt. It is uncertain that the authors of the isoglosses kept in mind the systematic character of the studied phenomena for establishing the boundaries of this dialect. In all likelihood, the isoglosses represent the area where the phenomena were more frequently lexicalized rather than the area where they were actually spoken. Here the author attempts to set the eartern and western boundaries of the dialect in the province of Zamora by considering the lexicalized or systematic character of the phenomena. In addition, he identifies the different areas and subareas within those boundaries and, thereafter, compares his results with the representation received from Leonese dialectology. Relevant materials from the province of Zamora for this comparison are those included in the Linguistic Atlas of the Iberian Peninsula (ALPI, gathered in 1934 and 1935 by Aurelio M. Espinosa Jr. and Anibal Otero; more specifically, the materials of Cuaderno 1, published by David Heap in www.alpi.ca..

La validez de las isoglosas con que tradicionalmente se han señalado los límites del dialecto leonés en la provincia de Zamora, especialmente en lo que se refiere a su valor para representar hasta dónde había un dialecto leonés vivo en este territorio a principios del siglo XX, es algo que siempre ha estado en entredicho, toda vez que no es seguro que cuando se trazaron se tuviera en cuenta el carácter sistemático de los fenómenos, y muy probablemente indican hasta dónde eran más abundantes los restos lexicalizados de este dialecto leonés, más que hasta dónde tales fenómenos estaban vivos. El trabajo que aquí presentamos tiene por objeto fijar los límites fon

From leaves to landscape: A multiscale approach to assess fire hazard in wildland-urban interface areas.

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Ghermandi, Luciana; Beletzky, Natacha A; de Torres Curth, Mónica I; Oddi, Facundo J

2016-12-01

The overlapping zone between urbanization and wildland vegetation, known as the wildland urban interface (WUI), is often at high risk of wildfire. Human activities increase the likelihood of wildfires, which can have disastrous consequences for property and land use, and can pose a serious threat to lives. Fire hazard assessments depend strongly on the spatial scale of analysis. We assessed the fire hazard in a WUI area of a Patagonian city by working at three scales: landscape, community and species. Fire is a complex phenomenon, so we used a large number of variables that correlate a priori with the fire hazard. Consequently, we analyzed environmental variables together with fuel load and leaf flammability variables and integrated all the information in a fire hazard map with four fire hazard categories. The Nothofagus dombeyi forest had the highest fire hazard while grasslands had the lowest. Our work highlights the vulnerability of the wildland-urban interface to fire in this region and our suggested methodology could be applied in other wildland-urban interface areas. Particularly in high hazard areas, our work could help in spatial delimitation policies, urban planning and development of plans for the protection of human lives and assets. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Quantitative Index of Forest Structural Sustainability

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Jonathan A. Cale

2014-07-01

Full Text Available Forest health is a complex concept including many ecosystem functions, interactions and values. We develop a quantitative system applicable to many forest types to assess tree mortality with respect to stable forest structure and composition. We quantify impacts of observed tree mortality on structure by comparison to baseline mortality, and then develop a system that distinguishes between structurally stable and unstable forests. An empirical multivariate index of structural sustainability and a threshold value (70.6 derived from 22 nontropical tree species’ datasets differentiated structurally sustainable from unsustainable diameter distributions. Twelve of 22 species populations were sustainable with a mean score of 33.2 (median = 27.6. Ten species populations were unsustainable with a mean score of 142.6 (median = 130.1. Among them, Fagus grandifolia, Pinus lambertiana, P. ponderosa, and Nothofagus solandri were attributable to known disturbances; whereas the unsustainability of Abies balsamea, Acer rubrum, Calocedrus decurrens, Picea engelmannii, P. rubens, and Prunus serotina populations were not. This approach provides the ecological framework for rational management decisions using routine inventory data to objectively: determine scope and direction of change in structure and composition, assess excessive or insufficient mortality, compare disturbance impacts in time and space, and prioritize management needs and allocation of scarce resources.

Equations of bark thickness and volume profiles at different heights with easy-measurement variables

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Cellini, J. M.; Galarza, M.; Burns, S. L.; Martinez-Pastur, G. J.; Lencinas, M. V.

2012-11-01

The objective of this work was to develop equations of thickness profile and bark volume at different heights with easy-measurement variables, taking as a study case Nothofagus pumilio forests, growing in different site qualities and growth phases in Southern Patagonia. Data was collected from 717 harvested trees. Three models were fitted using multiple, non-lineal regression and generalized linear model, by stepwise methodology, iteratively reweighted least squares method for maximum likelihood estimation and Marquardt algorithm. The dependent variables were diameter at 1.30 m height (DBH), relative height (RH) and growth phase (GP). The statistic evaluation was made through the adjusted determinant coefficient (r2-adj), standard error of the estimation (SEE), mean absolute error and residual analysis. All models presented good fitness with a significant correlation with the growth phase. A decrease in the thickness was observed when the relative height increase. Moreover, a bark coefficient was made to calculate volume with and without bark of individual trees, where significant differences according to site quality of the stands and DBH class of the trees were observed. It can be concluded that the prediction of bark thickness and bark coefficient is possible using DBH, height, site quality and growth phase, common and easy measurement variables used in forest inventories. (Author) 23 refs.

Males of Hylamorpha elegans burmeister (Coleoptera: Scarabaeidae) are attracted to odors released from conspecific females.

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Quiroz, Andrés; Palma, Ruben; Etcheverría, Paulina; Navarro, Vicente; Rebolledo, Ramón

2007-04-01

The behavioral responses of Hylamorpha elegans L. (Coleoptera: Scarabaeidae, Rutelinae) to the semiochemicals released from conspecific individual adults were studied, with particular attention paid to female attraction of males. Odors released from virgin females significantly attracted male conspecifics in both the field and laboratory olfactometer and wind tunnel bioassays. However, females did not attract other females, and males attracted no one. The response of male H. elegans to (1) compounds (1,4-hydroquinone and 1,4-benzoquinone) released only by unmated females; (2) the essential oil of the secondary host (Nothofagus obliqua); and (3) the blend of 1,4-hydroquinone and 1,4-benzoquinone with N. obliqua essential oil was studied. The blend of 1,4-benzoquinone mixed with essential oil at the trial concentration was attractive with males. The same response was found with 1,4-hydroquinone alone. The essential oil did not have the expected attractant effect on conspecific males. These results suggest that, when combined with essential oil, 1,4-benzoquinone may function in the sexual behavior of males and females. These findings are discussed in terms of the ecological role of this putative sexual pheromone and its potential use in a strategy of control of this pest.

Two new Liolaemus lizards from the Andean highlands of Southern Chile (Squamata, Iguania, Liolaemidae)

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Troncoso-Palacios, Jaime; Diaz, Hugo A.; Puas, German I.; Riveros-Riffo, Edvin; Elorza, Alvaro A.

2016-01-01

Abstract Liolaemus is a diverse genus of lizards, subdivided into two subgenera: Liolaemus (sensu stricto) and Eulaemus, distributed mainly in Chile and Argentina. The Liolaemus elongatus-kriegi complex is the most diverse group within Liolaemus (sensu stricto), especially the species closely related to Liolaemus elongatus, which form a clade currently comprising nine species. Several Chilean species of this group have been recently described, mainly from volcanoes and poorly explored mountains. Here molecular and morphological evidence are provided for a new species of the Liolaemus elongatus clade, which is characterized by its small size and lack of dorsal pattern, unusual features for the species of this group of lizards. Additionally, the lack of precloacal pores in males of Liolaemus (sensu stricto) is a trait found in few species, which do not constitute a monophyletic group. A second new southern Chilean species is also described, without precloacal pores and supported by molecular phylogenetics to be related to Liolaemus villaricensis. Both new species were found in the same locality, near a lake located in a pre-Andean zone with Araucaria and Nothofagus forest. The two species are dedicated to prominent Lonkos (tribal chiefs) of the Mapuche and Pehuenche people: Janequeo and Leftraru. Additionally, the phylogenetic results suggest that Liolaemus lonquimayensis is a synonym of Liolaemus elongatus. PMID:27920609

A new species of Lentiella (Cestoda: Anoplocephalidae from Proechimys simonsi (Rodentia: Echimyidae in Bolivia Una especie nueva de Lentiella (Cestoda: Anoplocephalidae de Proechimys (Rodentia: Echimyidae en Bolivia

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Terry R. Haverkost

2008-08-01

Full Text Available During a biodiversity survey of mammals and their parasites in the Beni, Bolivia in the summer of 2000, several spiny rats, Proechimys simonsi Thomas, 1900, were collected and examined for parasites. Herein we describe Lentiella lamothei n. sp. from one of these hosts. This species is can be distinguished from L. machadoi Rêgo, 1964 by having a greater total length but smaller maximum width, a greater number of segments, a smaller cirrus sac, a smaller scolex diameter, and in the eggs, a larger pyriform apparatus. In addition, we formally validate the genus Lentiella Rêgo, 1964, that had been placed in synonomy with Monoecocestus Beddard, 1914.Como parte del monitoreo de la biodiversidad de Bolivia, varias ratas espinosas (Proechimys simonsi Thomas, 1900 fueron examinadas en busca de parásitos durante el verano boreal del año 2000. En el presente trabajo se describe el céstodo Lentiella lamothei n. sp. recolectado en estos hospederos. Esta especie puede distinguirse de L. machadoi Rêgo, 1964 por tener una mayor longitud total pero menor ancho máximo, mayor número de proglótidos, bolsa del cirro más pequeña, escólex de menor diámetro, y un mayor aparato piriforme en los huevos. Además, se revalida formalmente al género Lentiella Rêgo, 1964, anteriormente sinonimizado con Monoecocestus Beddard, 1914.

Variabilidad genética en Prosopis ferox (Mimosaceae

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Alicia D. Burghardt

2004-01-01

Full Text Available Prosopis ferox (Mimosaceae es una especie arbustiva o arbórea espinosa que se distribuye desde el Sur de Bolivia hasta el noroeste de la Argentina. En la provincia de Jujuy se encuentra a grandes alturas (entre los 2400 y los 3700 m s.m.. Existe una gran variabilidad morfológica, especialmente en cuanto a las dimensiones del fruto y la cantidad de semillas por fruto, ambas características importantes debido al uso de esta planta como forraje. Con el objeto de verificar si existe además variabilidad genética, se realizó un estudio electroforético de proteínas seminales de árboles procedentes de distintas localidades de la provincia de Jujuy. Los patrones polipeptídicos obtenidos por SDS-PAGE presentaron en total 26 bandas. Cada población se caracterizó por sus patrones de presencia-ausencia de bandas, habiéndose encontrado variabilidad intrapoblacional (polimorfismo en algunas de ellas, siendo otras genéticamente homogéneas. Los índices polimórficos en poblaciones de P. ferox son comparables a los obtenidos previamente en P. ruscifolia. La variabilidad genética interpoblacional hallada por medio del estudio electroforético de las proteínas seminales hace suponer la existencia de ecotipos

Abundancia y distribución de larvas de Strombus gigas (Mesogastropoda: Strombidae durante el período reproductivo de la especie en el Caribe Mexicano

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José Francisco Chávez Villegas

2012-03-01

Full Text Available El caracol rosa (Strombus gigas, Linnaeus, 1758 es una especie de importancia económica en el Mar Caribe, por lo cual, en la década de 1980 representó la segunda pesquería después de la langosta espinosa, razón por la que actualmente se encuentra en estado de sobrepesca. Con el objetivo de determinar la variación en la abundancia de larvas durante la época reproductiva, cuatro localidades del Caribe Mexicano “CM” (México: Puerto Morelos, Sian Ka’an, Mahahual; Belice: San Pedro fueron muestreadas. Mensualmente, de mayo a octubre del 2008, se realizaron arrastres de plancton en cada localidad empleando una red cónica (300μm. Temperatura (°C, salinidad (ppm y oxígeno disuelto (mg L-1 fueron registrados para cada sitio. Una densidad media larval de 0.34±0.87 larvas•10m-3 fue registrada entre localidades, con un pico de abundancia entre agosto y septiembre (0.82±1.00 y 0.76±1.68 larvas 10m-3, respectivamente. La densidad larval tuvo una correlación del 60% con la salinidad (r=0.6063, p0.05. El 100% de las larvas capturadas corresponden al estadio I definido por Davis et al (1993, mostrando actividad reproductiva local, de esta manera, se considera que los sitios muestreados en el CM son fuente de larvas para la especie S. gigas.

Demanda e oferta no encontro entre profissionais de saúde mental e familiares de pessoas com sofrimento psíquico

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Teresinha Cid Constantinidis

2015-02-01

Full Text Available Este artigo é um desdobramento de tese de doutorado defendida pela Universidade Federal do Espírito Santo. Pretende-se analisar a elucidação de necessidades, a elaboração de demanda e oferta, no processo de produção de cuidado, na relação entre profissionais de saúde mental e familiares de pessoas com sofrimento psíquico. A perspectiva qualitativa de investigação configurou-se como método para alcançar os objetivos propostos. Foram realizadas entrevistas semi estruturadas com profissionais de saúde mental de dois centros de atenção psicossocial (CAPS do município de Vitória ES e com familiares de usuários destas instituições. Após análise temática do conteúdo, foram evidenciados sentidos, significados e valores atribuídos às necessidades, demandas e ofertas, presentes nessa relação. É evidenciada a disparidade entre demanda e oferta, a desvalorização, o desconhecimento das necessidades dos familiares e as demandas dos familiares relacionadas à lógica manicomial. Tendo como referência a ética na filosofia de Espinosa, são discutidas as consequências do encontro entre profissionais de saúde mental e familiares de pessoas com sofrimento psíquico e a micropolítica da produção de cuidado no contexto desses atores.

When learning a second language does not mean losing the first: bilingual language development in low-income, Spanish-speaking children attending bilingual preschool.

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Winsler, A; Díaz, R M; Espinosa, L; Rodríguez, J L

1999-01-01

This article discusses two investigations which explored the bilingual language development outcomes of comparable groups of low-income, Spanish-speaking, Mexican American children who either did or did not attended a bilingual (Spanish/English) preschool. Study 1 is a replication of a study by Rodríguez, Díaz, Duran, and Espinosa, involving a new sample of 26 children who attended bilingual preschool for one year and 20 control children who remained at home. Study 2 represents a 1-year, longitudinal follow-up of Rodríguez et al.'s, sample of children during and after the children spent another year at home or in the preschool. In both investigations, standardized, objective measures of three components of children's language proficiency (productive language, receptive language, and language complexity) in English and Spanish were obtained at the beginning and end of the academic year. Contrary to fears that have been expressed by some that early exposure to English would lead to children's native language loss, the results of both studies offered no evidence of Spanish proficiency loss for children attending bilingual preschool. Children who attended bilingual preschool, compared to those who remained at home, showed significant and parallel gains in Spanish language development as well as significant and greater increases in English language proficiency over time. Results are discussed in terms of the need for more systematic research to be conducted in this area to inform policy and practice in the early education and development of language-minority children.

The Gondwanan connection - Southern temperate Amanita lineages and the description of the first sequestrate species from the Americas.

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Truong, Camille; Sánchez-Ramírez, Santiago; Kuhar, Francisco; Kaplan, Zachary; Smith, Matthew E

2017-08-01

Amanita is a diverse and cosmopolitan genus of ectomycorrhizal fungi. We describe Amanita nouhrae sp. nov., a new hypogeous ('truffle-like') species associated with Nothofagus antarctica in northern Patagonia. This constitutes the first report of a sequestrate Amanita from the Americas. Thick-walled basidiospores ornamented on the interior spore wall ('crassospores') were observed consistently in A. nouhrae and its sister epigeous taxon Amanita morenoi, a rarely collected but apparently common species from northern Patagonia that has sometimes been misidentified as the Australian taxon Amanita umbrinella. Nuclear 18S and 28S ribosomal DNA and mitochondrial 16S and 26S DNA placed these two species in a southern temperate clade within subgenus Amanita, together with other South American and Australian species. Based on a dated genus-level phylogeny, we estimate that the southern temperate clade may have originated near the Eocene/Oligocene boundary (ca. 35 Ma ± 10 Ma). This date suggests a broadly distributed ancestor in the Southern Hemisphere, which probably diversified as a result of continental drift, as well as the initiation of the Antarctic glaciation. By comparison, we show that this clade follows an exceptional biogeographic pattern within a genus otherwise seemingly dominated by Northern Hemisphere dispersal. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Attraction and antennal response of the common wasp, Vespula vulgaris (L.), to selected synthetic chemicals in New Zealand beech forests.

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El-Sayed, Ashraf M; Manning, Lee-Anne; Unelius, C Rikard; Park, Kye Chung; Stringer, Lloyd D; White, Nicola; Bunn, Barry; Twidle, Andrew; Suckling, David M

2009-09-01

The common wasp, Vespula vulgaris (L.), and the German wasp, Vespula germanica (F.), are significant problems in New Zealand beech forests (Nothofagus spp.), adversely affecting native birds and invertebrate biodiversity. This work was undertaken to develop synthetic attractants for these species to enable more efficient monitoring and management. Seven known wasp attractants (acetic acid, butyl butyrate, isobutanol, heptyl butyrate, octyl butyrate and 2,4-hexadienyl butyrate) were field tested, and only heptyl butyrate and octyl butyrate attracted significantly higher numbers of wasps than a non-baited trap. Accordingly, a series of straight-chain esters from methyl to decyl butyrate were prepared and field tested for attraction of social wasps. Peak biological activity occurred with hexyl butyrate, heptyl butyrate, octyl butyrate and nonyl butyrate. Polyethylene bags emitting approximately 18.4-22.6 mg day(-1) of heptyl butyrate were more attractive than polyethylene bags emitting approximately 14.7-16.8 mg day(-1) of heptyl butyrate in the field. Electroantennogram (EAG) studies indicated that queens and workers of V. vulgaris had olfactory receptor neurons responding to various aliphatic butyrates. These results are the first to be reported on the EAG response and the attraction of social wasps to synthetic chemicals in New Zealand beech forests and will enable monitoring of social wasp activity in beech forests. Copyright 2009 Society of Chemical Industry.

Saccharomyces eubayanus and Saccharomyces uvarum associated with the fermentation of Araucaria araucana seeds in Patagonia.

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Rodríguez, M Eugenia; Pérez-Través, Laura; Sangorrín, Marcela P; Barrio, Eladio; Lopes, Christian A

2014-09-01

Mudai is a traditional fermented beverage, made from the seeds of the Araucaria araucana tree by Mapuche communities. The main goal of the present study was to identify and characterize the yeast microbiota responsible of Mudai fermentation as well as from A. araucana seeds and bark from different locations in Northern Patagonia. Only Hanseniaspora uvarum and a commercial bakery strain of Saccharomyces cerevisiae were isolated from Mudai and all Saccharomyces isolates recovered from A. araucana seed and bark samples belonged to the cryotolerant species Saccharomyces eubayanus and Saccharomyces uvarum. These two species were already reported in Nothofagus trees from Patagonia; however, this is the first time that they were isolated from A. araucana, which extends their ecological distribution. The presence of these species in A. araucana seeds and bark samples, led us to postulate a potential role for them as the original yeasts responsible for the elaboration of Mudai before the introduction of commercial S. cerevisiae cultures. The molecular and genetic characterization of the S. uvarum and S. eubayanus isolates and their comparison with European S. uvarum strains and S. eubayanus hybrids (S. bayanus and S. pastorianus), allowed their ecology and evolution us to be examined. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Estrés Laboral en Médicos Residentes del Hospital Nacional Carlos Alberto Seguín Escobedo y del Hospital Regional Honorio Delgado Espinosa. Arequipa, 2015

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Mazeyra Guillén, Alvaro Augusto

2017-01-01

El presente estudio tuvo como objetivos determinar el estrés laboral en los médicos residentes del Hospital “Carlos Alberto Seguín Escobedo” de EsSalud (HNCASE). y del Hospital Regional “Honorio Delgado Espinosa” (HRHDE) y establecer las semejanzas y diferencias del estrés laboral de los médicos residentes de ambos hospitales. La población estuvo conformada por 220 médicos residentes de primero, segundo y tercer año de residencia. Se aplicó el muestreo al azar estratifica...

¿Germanismo o romanismo? Una espinosa cuestión en el tránsito del mundo antiguo a la Edad Media: el caso de los visigodos

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Guzmán Armario, Francisco Javier

2005-06-01

Full Text Available Traditionally, the historiography has considered the Visigoths like a people with national identity totally constituted to its entrance in the Roman Empire (376 AD, and like the creators of a Hispanic State of germanic essence. Nevertheless, the Visigoths, like other barbarian peoples that penetrated in the imperial territory in IV and V centuries AD, lacked such national unit and were influenciated by the political and cultural force of the Roman civilisation. In that sense, the importance of romanitas is the preeminent element in the birth of the new States of western Europe at the beginning of the Middle Ages

Tradicionalmente, la historiografía ha considerado a los visigodos como un pueblo con identidad nacional plenamente constituida a su entrada en el Imperio Romano (376, y como los creadores de un Estado hispánico de esencia germánica. Sin embargo, los visigodos, como otros pueblos bárbaros que penetraron en el territorio imperial en los siglos IV y V d. C, carecían de tal unidad y estaban muy condicionados por la influencia política y cultural de la civilización romana. En ese sentido, la importancia de la romanidad es el elemento preeminente en el nacimiento de los nuevos Estados de Europa occidental a principios de la Edad Media.

Estado actual del conocimiento de la familia Ceratopogonidae en la Patagonia (Diptera: Nematocera Current knowledge of the family Ceratopogonidae in Patagonia (Diptera: Nematocera

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Gustavo R. Spinelli

2009-06-01

Full Text Available Ceratopogonidae incluye pequeños dípteros nematoceros que crían en hábitats acuáticos o semiacuáticos. Hasta los '80, el conocimiento de su taxonomía en la Patagonia se hallaba limitado a la contribución de los comienzos de los '30 de Ingram y Macfie, sobre la base de material capturado en 1926-27, en el área del Parque Nacional Nahuel Huapi y zonas vecinas de Chile. En los últimos 25 años, se pusieron en marcha diferentes proyectos, resultando la descripción o registro de numerosos taxones para la región. Si se contabilizan los datos publicados, 102 especies habitan en la Patagonia, de las cuales 86 (84,31% son endémicas para la región. Este alto porcentaje es evidente en los bosques de Nothofagus, con 71 especies endémicas de este bioma, nueve lo son de la estepa y seis presentan registros en bosque y estepa. Datos aún no publicados concuerdan con este esquema. Diecinueve géneros están representados en la Patagonia, diez de ellos con amplia distribución, tres de distribución transantártica y seis son endémicos para el área. Para la misma, se hallan publicadas las revisiones de Forcipomyia, Atrichopogon, Borkenthelea, Macrurohelea y Paradasyhelea; se han finalizado y aún no publicado aquellas de Dasyhelea y Palpomyia, está muy avanzada la de Stilobezzia y se prevé comenzar con las de Austrohelea, Austrosphaeromias, Physohelea y Bezzia. Se calcula que estos datos no divulgados contienen al menos 55 especies todavía no descriptas. Con respecto a los aspectos biogeográficos se pueden destacar estudios que tienden a establecer relaciones entre las áreas reconocidas en esquemas biogeográficos propuestos para la región andina.Ceratopogonidae includes small nematoceran Diptera which breed in aquatic and semiaquatic habitats. Until the 80´s its taxonomic knowledge in Patagonia was limited to the early 30´s contribution of Ingram and Macfie, from material collected in 1926-27 in the area of the Nahuel Huapi National

Late Holocene vegetation dynamics and lake geochemistry at Laguna Miranda, XI Region, Chile Dinámica vegetaciónal y geoquímica lacustre del Holoceno tardío en Laguna Miranda, XI Región, Chile

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S. G. HABERLE

2000-12-01

Full Text Available Palynological and geochemical analysis of late Holocene lake sediments and dendrochronological analysis of Pilgerodendron in a volcanically active region of southern Chile reveal the long-term impact of a series of tephra fall events and tectonic activity on lake sedimentation and local vegetation. An upper 0,75 m core overlaps with a 4,35 m long Livingstone piston core to give a 4,60 m long sediment record, extending back to 4800 yr BP. Geochemical data shows the shift from allogenic dominance to authigenic and biogenic dominance as waterlogged soils developed within the catchment. This is presumed to have occurred under the influence of continued addition of nutrients to the catchment from tephra deposition and the associated high sedimentation rates. The palynological record from this site is dominated by Nothofagus dombeyi-type and Filicales. The most prominent changes in the pollen record, however, are the gradual decline in Podocarpus nubigena pollen throughout the last 4800 yr; the appearance and increase of Gramineae pollen during the past 2100 yr; and the rapid increase in the pollen of Pilgerodendron uviferum within the past 300-400 yr. Pilgerodendron tree-ring analysis and the pollen results over the last 400 years show that the most recent expansion of Pilgerodendron at the northern and eastern margins of this site is a response to either, periodic tectonic induced watertable changes, or is part of a long-term trend in gymnosperm growth around a shallowing lake margin. The decline of shade-intolerant trees such as Weinmannia and Podocarpus within a Nothofagus-rich forest community towards an increased presence of Pilgerodendron and Gramineae (likely Chusquea bamboo, that began over 2100 yr BP, may have been due as much to autogenic processes such as a change in the disturbance regime resulting in the development of waterlogged soils, rather than to an episode of climate change. It is important to recognise the potential effects of

Morphological Studies on the Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae, Triatominae Genital Structures and Eggs of Different Chromatic Forms

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Jane Costa

1997-07-01

Full Text Available Triatoma brasiliensis is considered one of the most important Chagas disease vectors being a widespread species in semiarid areas of northeastern Brazil. The species displays distinct chromatic patterns of the cuticle in different localities. Four populations were analyzed in this study: 1-Caicó, Rio Grande do Norte, it will be called the brasiliensis population; 2-Espinosa, Minas Gerais, the melanica population; 3-Petrolina, Pernambuco, the macromelasoma population, and 4-Juazeiro, Bahia, the darker one in overall cuticle coloration, the Juazeiro population. In order to differentiate the four populations of T. brasiliensis, a comparative morphological analysis of external genital structures and of eggs were carried out. The analysis of the male genital structures evidenced minor individual structural variations that did not correlate with chromatic differences or the geographical origins, emphasizing the importance of examining sufficiently large and representative samples before using minor genital variations for taxonomic diagnosis. By scanning electron microscopy of the egg exochorion, each chromatic population presented a distinct ornamentation pattern. The melanica population differed mainly from the other populations studied since it had about 40.6%, 69.6% and 76.6% more perforations, on each cell exochorion, than the brasiliensis, the Juazeiro and the macromelasoma populations respectively. In the melanica population the perforation layout is also peculiar, with densely distributed perforations over all the egg surface. Morphometric measures of the eggs showed statistically significant differences: the macromelasoma population presented the longest length (2.43 mm while the shortest was recorded in the brasiliensis population (2.29 mm.

Tratamiento por Medicina Natural y Tradicional de la rinitis alérgica

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Yanelis Santos Díaz

2015-11-01

Full Text Available La rinitis alérgica es uno de los problemas de salud más comunes y una de las principales causas de consulta médica en el mundo y en Cuba. Los resultados de los métodos de Medicina Natural y Tradicional han sido contradictorios en la terapia de la enfermedad. Se estudiaron 50 pacientes atendidos en el Servicio de Medicina Natural y Tradicional del Policlínico “Aquiles Espinosa Salgado” del municipio de Las Tunas, desde septiembre del 2008 a septiembre de 2009. El esquema de tratamiento tuvo en cuenta los puntos V2, IG4, B10, VG20 y E3 en dos sesiones semanales durante ocho semanas, hasta completar 16 sesiones; al culminar la 2da, 4ta, 6ta, 8va semana se valoraron los resultados con una encuesta. La obstrucción nasal fue el síntoma más frecuente en los enfermos atendidos, en el 96% de los casos. Al finalizar el esquema de tratamiento, el 86% de los sujetos mejoraron la severidad y frecuencia de los síntomas. Solo se reportó un efecto adverso, con la formación de un hematoma en el sitio de aplicación, lo que fue catalogado como reacción leve. No ocurrieron salidas ni pérdidas de casos en el estudio. El esquema aplicado tuvo resultados satisfactorios, lo que refuerza la utilidad de los métodos de medicina natural y tradicional en el manejo de la rinitis alérgica.

Fractional hereditariness of lipid membranes: Instabilities and linearized evolution.

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Deseri, L; Pollaci, P; Zingales, M; Dayal, K

2016-05-01

In this work lipid ordering phase changes arising in planar membrane bilayers is investigated both accounting for elasticity alone and for effective viscoelastic response of such assemblies. The mechanical response of such membranes is studied by minimizing the Gibbs free energy which penalizes perturbations of the changes of areal stretch and their gradients only (Deseri and Zurlo, 2013). As material instabilities arise whenever areal stretches characterizing homogeneous configurations lie inside the spinoidal zone of the free energy density, bifurcations from such configurations are shown to occur as oscillatory perturbations of the in-plane displacement. Experimental observations (Espinosa et al., 2011) show a power-law in-plane viscous behavior of lipid structures allowing for an effective viscoelastic behavior of lipid membranes, which falls in the framework of Fractional Hereditariness. A suitable generalization of the variational principle invoked for the elasticity is applied in this case, and the corresponding Euler-Lagrange equation is found together with a set of boundary and initial conditions. Separation of variables allows for showing how Fractional Hereditariness owes bifurcated modes with a larger number of spatial oscillations than the corresponding elastic analog. Indeed, the available range of areal stresses for material instabilities is found to increase with respect to the purely elastic case. Nevertheless, the time evolution of the perturbations solving the Euler-Lagrange equation above exhibits time-decay and the large number of spatial oscillation slowly relaxes, thereby keeping the features of a long-tail type time-response. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Historical Foundations. Historical Architectural Treaty How Information Source of the Architectonic Heritage

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Fernando Da Casa

2011-12-01

Full Text Available In order to address architectural heritage conservation, we must be familiar with the medium with which we will be working, its function and response to incidents or external actions (natural or anthropogenic and how the buildings were conceived and constructed in order to understand how they will be affected by the intervention process to which they will be subjected and adopt the adequate measures so these processes will not harm the buildings. An important element is the foundation. This is a fundamental, yet often forgotten, element. It is important to know the history of the foundations, how and why they were constructed and for this, it is essential to study architectural treatises as the origin of their design. It is surprising to read classical architecture treatises and observe that they do not refer to calculations of dimensions, but to constructive solutions that today may seem clever because they are obvious, but in reality, they do not address the thoughts of the designer or builder. The historic architectural treatises on construction that significantly influenced Spanish construction, which we studied and will present in this article, include Vitruvius and Palladio as well as the developments in the eighteenth and nineteenth centuries, and even into the first half of the twentieth century: (Vitruvius (1st century BC, Palladio (1524, Alberti (1582, Cristóbal de Rojas (1598, Fray Laurencio San Nicolás (1639, Brizguz y Bru (1738, Rieger (1763, Fornes y Gurrea (1841, Espinosa (1859, Marcos y Bausá (1879, Ger y Lobez (1898 and Barberot (1927.

Las tecnologías de la información y la comunicación (tic en la Universidad Francisco de Paula Santander

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Jhon Franklin Espinosa-Castro

2011-01-01

Full Text Available The information and communication technologies (ICT, today are establishing a change in humans, especially in the university education system in the process of teaching and learning where to use and apply effectively. To help students acquire the skills necessary to gather the elements and techniques used in the processing and transmission of information, especially information technology, internet and telecommunications. Given the above, the University Francisco de Paula Santander was not found any records about the technologies of information and communication technologies (ICT. Due, not to establishing research, and also students are not knowledgeable in the use and implementation within the different careers that established information. He must, that 73% of students surveyed used the Internet for UFPS for different activities. Furthermore, accessing the service using a laptop in the green spaces, cubicles, rooms or in corridors of buildings, especially the green areas, because it is the place that has better coverage. Also, 436 students of 1000 established a score of 3 on a scale of 1 to 5. Where Las tecnologías de la información y la comunicación (tic en la Universidad Francisco de Paula Santander Jhon Franklin Espinosa Castro1 . 12 the university community uses the Internet chat service, social networking, music and games. At the same time, it is expected that this research, propose alternatives to improve the quality of teaching and learning, as students need to know the advantages provided by ICT to successfully work with technological advances.

Plesiosaur-bearing rocks from the Late Cretaceous Tahora Fm, Mangahouanga, New Zealand - a palaeoenvironmental study

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Vajda, Vivi; Raine, J. Ian

2010-05-01

Mangahouanga Stream, Hawkes Bay, New Zealand is world-famous for its high southern latitude vertebrate fossils including plesiosaurs, mosasaurs and more rarely, dinosaurs. The fossils are preserved in the conglomeratic facies of the Maungataniwha Sandstone Member of the Tahora Formation. A palynological investigation of sediments from the boulders hosting vertebrate fossils reveals well-preserved palynological assemblages dominated by pollen and spores from land plants but also including marine dinoflagellate cysts in one sample. The palynofacies is strongly dominated by wood fragments including charcoal, and the sample taken from a boulder hosting plesiosaur vertebrae is entirely terrestrially derived, suggesting a fresh-water habitat for at least some of these plesiosaurs. The key-pollen taxa Nothofagidites senectus and Tricolpites lilliei, together with the dinocyst Isabelidinium pellucidum and the megaspore Grapnelispora evansii, strongly indicate an early Maastrichtian age for the host rock. The terrestrial palynoflora reflects a mixed vegetation dominated by podocarp conifers and angiosperms with a significant tree-fern subcanopy component. The presence of taxa with modern temperate distributions such as Nothofagus (southern beech), Proteaceae and Cyatheaceae (tree-ferns), indicates a mild-temperate climate and lack of severe winter freezing during the latest Cretaceous, providing an ecosystem which most probably made it possible for polar dinosaurs to overwinter. The paper is dedicated to Mrs Joan Wiffen who with her great persistence, enthusiasm and courage put Mangahouanga on the world map, becoming a role model for many young scientists.

Assessing the interaction between mountain forests and snow avalanches at Nevados de Chillán, Chile and its implications for ecosystem-based disaster risk reduction

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Casteller, Alejandro; Häfelfinger, Thomas; Cortés Donoso, Erika; Podvin, Karen; Kulakowski, Dominik; Bebi, Peter

2018-04-01

Gravitational natural hazards such as snow avalanches, rockfalls, shallow landslides and volcanic activity represent a risk to mountain communities around the world. In particular, where documentary records about these processes are rare, decisions on risk management and land-use planning have to be based on a variety of other sources including vegetation, tree-ring data and natural hazard process models. We used a combination of these methods in order to evaluate dynamics of natural hazards with a focus on snow avalanches at Valle Las Trancas, in the Biobío region in Chile. Along this valley, natural hazards threaten not only the local human population, but also the numerous tourists attracted by outdoor recreational activities. Given the regional scarcity of documentary records, tree-ring methods were applied in order to reconstruct the local history of snow avalanches and debris flow events, which are the most important weather-related processes at respective tracks. A recent version of the model Rapid Mass MovementS (RAMMS), which includes influences of forest structure, was used to calculate different avalanche parameters such as runout distances and maximum pressures, taking into consideration the presence or absence of forest along the tracks as well as different modeled return periods. Our results show that local Nothofagus broadleaf forests contribute to a reduction of avalanche runout distances as well as impact pressure on present infrastructure, thus constituting a valuable ecosystem disaster risk reduction measure that can substitute or complement other traditional measures such as snow sheds.

Magellanic Woodpeckers in three national parks of central-southern Chile: habitat effects and population variation over the last two decades

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Pablo M. Vergara

2017-12-01

Full Text Available A major challenge for protected areas is providing wildlife with enough suitable habitat to cope with stochastic environment and increased pressure from the surrounding landscapes. In this study, we addressed changes in local populations of Magellanic Woodpeckers (Campephilus magellanicus occupying three national parks of central-southern Chile. We compared the breeding and postbreeding abundance of woodpeckers during the 1990s with the present (2016 abundance (n = 4 years, and assessed the extent to which abundance was explained by forest type and quality of foraging habitat (as quantified through the plant senescence reflectance index; PSRI. Results show a distinctive temporal variation in woodpecker abundance at each park, with local populations of Magellanic Woodpeckers declining by 42.2% in Conguillío National Park, but increasing by 34.3% in Nahuelbuta National Park. Woodpeckers responded to forest conditions within each park such that their abundance increased with high quality of foraging habitat, i.e., large PSRI values, and the presence of old-growth Monkey puzzle (Araucaria araucana - Nothofagus pumilio mixed forest. Anecdotal evidence suggests that populations of woodpeckers in Conguillío National Park might have responded negatively to large-scale disturbances from recent forest fires affecting part of the forest area within park. Because stochastic events seemed to strongly mediate population changes, our findings suggest that regional conservation of Magellanic Woodpeckers requires expanding the current conservation area network in central-southern Chile.

Paleoenvironmental and paleoclimatic investigations on Isla de los Estados, Argentina

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Björck, S.; Fernandez, M.; Hjort, C.; Ljung, K.; Martinez, O.; Möller, P.; Ponce, F.; Rabassa, J.; Roig, F.; Unkel, I.; Wohlfarth, B.

2007-05-01

The expedition in November-December 2005 to Isla de los Estados (Staten Island) off the southeastern tip of South America was a cooperative venture between Lund University (LU) and Stockholm University (SU) in Sweden and the CADIC-CONICET Institute in Ushuaia, Argentina. The aim of the expedition was threefold: (1) to extend the Swedish paleoclimatic "ATLANTIS"-project (Greenland, Iceland, Faroe Islands, Azores, Grenada, Tristan da Cunha; PI S Björck) to the southern part of the South American continent, (2) to connect earlier glacial and climate history reconstructions from the Antarctic Peninsula to equivalents north of the Drake Passage in southernmost South America, and (3) to complement paleo-information available from the Tierra del Fuego mainland with information from Isla de los Estados. Focus was on two areas in the northern and north-western part of the island, Bahía Colnett and Bahia Crossley. Detailed geomorphologic and stratigraphic mapping of glacial deposits were combined with sampling sediments for OSL dating. To reconstruct the paleoclimatic development of Isla de los Estados since the last ice retreat, four main peat bog/lake sites were cored and sampled. In addition, living trees of Nothofagus and old logs preserved in the peat were sampled for dendrochronological and dendroclimatological studies. Preliminary results show that the deglaciation of the study area occurred before 16500 cal yr BP. Detailed multi- proxy analyses of the four sequences are under way and first results will be presented.

Palynological analysis of camelid coprolites: seasonality in the use of the site Cerro Casa de Piedra 7 (Santa Cruz, Argentina)

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Velázquez, Nadia Jimena; Burry, Lidia Susana; Fugassa, Martín Horacio; Civalero, María Teresa; Aschero, Carlos Alberto

2014-01-01

Palynological, palaeoparasitological and paleobotanical studies of coprolites found in archaeological sites from Perito Moreno National Park (47°57‧S72°05‧W) yielded information on diet, palaeoenvironment and health. These studies allowed adding evidence to the reconstruction of life history of the hunter-gatherers that inhabited Patagonia during the Holocene. We examined the season of the year when camelid Lama guanicoe coprolites (5400 ± 64 yr 14C BP to 9640 ± 190 yr 14C BP) were deposited at Cerro Casa de Piedra 7 (site CCP7). The study used palynological evidence and comparison with pollen spectra of modern feces collected during summer, fall, winter and spring of 2010. The dominant types were: pollen of Nothofagus, Empetrum rubrum, Asteraceae subfam. Asteroideae, Nassauvia, Caryophyllaceae and Poaceae; fern spores; remains of Eimeria macusaniensis; and plant remains of Poaceae, Festuca pallescens, Stipa speciosa, Armeria maritima, Gaultheria mucronata and E. rubrum. Pollen spectra of modern and fossil feces were used for multivariate analysis. Coprolites associated to fall and winter modern feces. These results and those obtained from pollen concentration values and the presence of pollen types indicators of seasonality, allowed the determination of summer, fall and winter coprolites. However, caution must be taken with the seasonality results of coprolites dated earlier than 9000 years BP since the environmental conditions differed from now. The site was probably a camelid shelter during the unfavorable seasons.

VOCES EN EL BOSQUE: EL USO DE RECURSOS VEGETALES ENTRE CAZADORES-RECOLECTORES DE LA ZONA CENTRAL DE TIERRA DEL FUEGO

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Laura Caruso

2008-01-01

Full Text Available Se estudiaron las modalidades de aprovechamiento de las plantas entre los Selknam de Tierra del Fuego (Argentina y se presentan aquí los resultados obtenidos a partir del análisis de los restos de madera carbonizada y sin carbonizar del sitito Ewan, ocupado a principios del siglo XX para la realización de un ritual de iniciación. Los resultados permitieron una mejor comprensión de las estrategias de aprovechamiento de las plantas entre las sociedades cazadoras-recolectoras. La identificación de las especies empleadas y el registro de las principales características morfométricas permitió documentar el aprovechamiento del "ñire" (Nothofagus antarctica. Esta especie, dominante en el entorno, fue utilizada para la construcción de la vivienda y como combustible. En ambos casos se seleccionaron troncos de forma y tamaño adecuados. Los resultados del trabajo arqueobotánico y su confrontación con los datos etnográficos evidenciaron la importancia de los recursos vegetales dentro de la dinámica socioeconómica de este grupo humano. Los recursos vegetales, más allá de su rol alimentario, fueron relevantes en otros aspectos tales como la tecnología, la construcción, el combustible y debieron constituir una ventaja considerable en el ámbito de los bosques de la zona central de Tierra del Fuego.

Microbe domestication and the identification of the wild genetic stock of lager-brewing yeast

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Libkind, Diego; Hittinger, Chris Todd; Valério, Elisabete; Gonçalves, Carla; Dover, Jim; Johnston, Mark; Gonçalves, Paula; Sampaio, José Paulo

2011-01-01

Domestication of plants and animals promoted humanity's transition from nomadic to sedentary lifestyles, demographic expansion, and the emergence of civilizations. In contrast to the well-documented successes of crop and livestock breeding, processes of microbe domestication remain obscure, despite the importance of microbes to the production of food, beverages, and biofuels. Lager-beer, first brewed in the 15th century, employs an allotetraploid hybrid yeast, Saccharomyces pastorianus (syn. Saccharomyces carlsbergensis), a domesticated species created by the fusion of a Saccharomyces cerevisiae ale-yeast with an unknown cryotolerant Saccharomyces species. We report the isolation of that species and designate it Saccharomyces eubayanus sp. nov. because of its resemblance to Saccharomyces bayanus (a complex hybrid of S. eubayanus, Saccharomyces uvarum, and S. cerevisiae found only in the brewing environment). Individuals from populations of S. eubayanus and its sister species, S. uvarum, exist in apparent sympatry in Nothofagus (Southern beech) forests in Patagonia, but are isolated genetically through intrinsic postzygotic barriers, and ecologically through host-preference. The draft genome sequence of S. eubayanus is 99.5% identical to the non-S. cerevisiae portion of the S. pastorianus genome sequence and suggests specific changes in sugar and sulfite metabolism that were crucial for domestication in the lager-brewing environment. This study shows that combining microbial ecology with comparative genomics facilitates the discovery and preservation of wild genetic stocks of domesticated microbes to trace their history, identify genetic changes, and suggest paths to further industrial improvement. PMID:21873232

Organic matter characterization and decomposition dynamics in sub-Antarctic streams impacted by invasive beavers Caracterización de la materia orgánica y la dinámica de descomposición en arroyos subantárticos impactados por castores invasores

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Erica Ulloa

2012-11-01

Full Text Available Despite being a relatively remote and well conserved area, the sub-Antarctic ecoregion faces pressing global threats from climate change, the ozone hole and introduced species. Its freshwater ecosystems are one of the least studied components of this biome, but they are known to confront a host of invasive taxa including trout and beavers. We set out to understand the basic characterization and dynamics of organic matter processing and decomposition in sub-Antarctic streams under natural forest (NF conditions and in ponds constructed by North American beavers (Castor canadensis (BP. We found these streams have a naturally stable benthic organic matter regime throughout the year with a peak in leaf input from Nothofagus pumilio in autumn. Beaver ponds significantly increased the retention of organic matter and caused significantly higher decomposition rates, probably associated with increased density and biomass of Hyalella spp. As expected, leaf decay rates for N. pumilio, a deciduous species, were higher (NF: -0.0028 day- ± 0.0001 SE; BP: -0.0118 day-1 ± 0.0009 SE than N. betuloides (a broad-leaf evergreen (NF: -0.0018 day-1 ± 0.0005 SE; BP: -0.0040 day-1 ± 0.0003 SE. Overall these results indicate that the naturally low decomposition rates (slower than 89% of a global survey of decay rates for these cold, oligotrophic streams are being modified by introduced beavers to resemble more temperate latitudes.A pesar de ser una zona relativamente remota y bien conservado, la ecorregión subantártica se enfrenta a presiones por amenazas globales por el cambio climático, el agujero de ozono y las especies introducidas. Los ecosistemas de agua dulce son uno de los componentes menos estudiados de este bioma, pero se sabe que enfrentan una serie de taxones invasivos como la trucha y los castores. El propósito de este estudio es entender la caracterización básica y dinámica de descomposición de la materia orgánica en arroyos subantárticos de

Identificación de los mecanismos subyacentes a la invasión de Castor canadensis (Rodentia en el archipiélago de Tierra del Fuego, Chile Identifying the mechanisms underlying the invasion of Castor canadensis (Rodentia into Tierra del Fuego archipelago, Chile

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PETRA K WALLEM

2007-09-01

Full Text Available Castor canadensis es considerado un ingeniero ecosistémico arquetípico, ya que altera el estado de factores bióticos y abióticos, mediante interacciones no tróficas, modificando sustancialmente los ecosistemas que habita. Esta especie fue introducida en la Isla Grande de Tierra del Fuego en 1946 por el gobierno argentino, con el fin de estimular la industria peletera. Actualmente se encuentra presente en las principales islas del archipiélago, incluyendo Tierra del Fuego, Navarino, Dawson y Hoste y ocupando habitat tan contrastantes como los bosques subpolares magallánicos, el matorral y la estepa patagónica. Su éxito en estos habitat sugiere que su expansión solo se verá limitada por la disponibilidad de recursos hídricos. De acuerdo a lo observado en Tierra del Fuego, en ausencia de un programa de control poblacional, los castores amenazan con establecerse en todos los bosques templados nativos del continente (entre los 35 y 55° S y ocupar los habitat de matorral y pastizal circundantes a los mismos. El presente artículo propone tres hipótesis referentes a los mecanismos subyacentes al éxito de esta invasión: el escape de enemigos naturales, la oportunidad de recursos, y la autofacilitación mediante interacciones no tróficas. Los antecedentes disponibles develan patrones conductuales (e.g., el establecimiento de colonias en forma independiente de la cercanía de recursos maderables, un aparente crecimiento poblacional irruptivo, así como una explotación centrada en Nothofagus pumilio, especie dominante en los bosques magallánicos que sugieren la operación de los mecanismos de escape de enemigos naturales y oportunidad de recursos. También se observa una mayor densidad de colonias activas en habitat que presentan mayor extensión de modificación ambiental, sugiriendo el accionar del mecanismo de autofacilitación. Si bien la información reunida no permite poner a prueba las hipótesis propuestas, sí entrega un marco

Influencia de las especies del dosel en la disponibilidad de recursos y regeneración avanzada en un bosque templado lluvioso del sur de Chile Influence of overstorey species identity on resource availability and variation in composition of advanced regeneration in a temperate rainforest in southern Chile

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ALFREDO SALDAÑA

2003-12-01

Full Text Available La heterogeneidad de hábitat en el sotobosque es un factor que promueve el mantenimiento de la diversidad de especies de la comunidad forestal. En este estudio se evaluó la influencia de cuatro especies dominantes de un bosque templado del sur de Chile, Laureliopsis philippiana, Aextoxicon punctatum, Eucryphia cordifolia y Nothofagus dombeyi, sobre la disponibilidad de recursos y su relación con la composición de la regeneración avanzada. Se estimó el porcentaje de luz difusa, la disponibilidad de nitrógeno, fósforo y calcio, el contenido de nitrógeno, fósforo y calcio de la hojarasca, y se determinó la composición de la regeneración avanzada bajo los doseles de cada una de las cuatro especies. Además, se realizó una ordenación para evaluar la variación de la composición de la regeneración avanzada. Se encontraron diferencias significativas en la transmisión de luz bajo cada especie, así como en el contenido nutricional de la hojarasca y disponibilidad de los nutrientes N-NO3 y P. Los tres nutrientes evaluados presentaron escasa disponibilidad en el suelo, debido a baja mineralización y alta inmovilización. De acuerdo a la ordenación, la composición de la regeneración avanzada bajo N. dombeyi y L. philippiana, fue distinguible de la composición de la regeneración bajo E. cordifolia y A. punctatum. La luz fue el recurso que explicó la mayor parte de la variación en la composición de la regeneración avanzada en el sotobosque. En cambio, la variación en la disponibilidad de nutrientes no tuvo relación con la especie en el dosel. Postulamos que las especies que regeneran bajo este dosel difieren más en sus requerimientos lumínicos que nutricionales, siendo la luz el recurso más limitante en el sotobosqueUnderstory habitat heterogeneity is a factor promoting maintenance of species diversity in forest communities. The influence of over storey species identity on resource availability and variation in composition of

Host-guest complex of N-(2-chloroethyl), N-nitroso, N‧, N‧ -dicyclohexylsulfamid with β-cyclodextrin: Fluorescence, QTAIM analysis and structure-chemical reactivity

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Bensouilah, Nadjia; Fisli, Hassina; Bensouilah, Hamza; Zaater, Sihem; Abdaoui, Mohamed; Boutemeur-Kheddis, Baya

2017-10-01

In this work, the inclusion complex of DCY/CENS: N-(2-chloroethyl), N-nitroso, N‧, N‧-dicyclohexylsulfamid and β-cyclodextrin (β-CD) is investigated using the fluorescence spectroscopy, PM3, ONIOM2 and DFT methods. The experimental part reveals that DCY/CENS forms a 1:1 stoichiometric ratio inclusion complex with β-CD. The constant of stability is evaluated using the Benesi-Hildebrand equation. The results of the theoretical optimization showed that the lipophilic fraction of molecule (cyclohexyl group) is inside of β-CD. Accordingly, the Nitroso-Chloroethyl moiety is situated outside the cavity of the macromolecule host. The favorable structure of the optimized complex indicates the existence of weak intermolecular hydrogen bonds and the most important van der Waals (vdW) interactions which are studied on the basis of Natural Bonding Orbital (NBO) analysis. The NBO is employed to compute the electronic donor-acceptor exchanges between drug and β-CD. Furthermore, a detailed topological charge density analysis based on the quantum theory of atoms in molecules (QTAIM), has been accomplished on the most favorable complex using B3LYP/6-31G(d) method. The presence of stabilizing intermolecular hydrogen bonds and van der Waals interactions in the most favorable complex is predicted. Also, the energies of these interactions are estimated with Espinosa's formula. The findings of this investigation reveal that the correlation between the structural parameters and the electronic density is good. Finally, and based on DFT calculations, the reactivity of the interesting molecule in free state was studied and compared with that in the complexed state using chemical potential, global hardness, global softness, electronegativity, electrophilicity and local reactivity descriptors.

Towards Year 2009, a 25 000 person rehearsal

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Fierro Gossman, Julieta; Espinosa, M.

2008-05-01

In this presentations we will talk about the way we planned and achieved successfully a 25 000 people observation in Mexico City downtown taking advantage of a lunar eclipse. We shall guide people so they think about their own activities. We shall mention the way we planned the event, carried out found raising and advertisement. We shall describe the way we handled people mainly during the observations with one hundred telescopes and parallel activities. These included: a public lecture enhanced with dance and hands-on demonstrations, workshops for children, workshops on the night sky, talking to an astronomer, how to handle a telescope and a picture exhibit as well as music till midnight. We shall also mentioned written materials for that particular event and for Year 2009, some of which were specially crafted for teachers. Hector Dominguez y Julieta Fierro Galileo y el telescopio, 400 anios de ciencia Uribe y Ferrari Editores, 2007 ISBN 970 756 238-2 Hector Dominguez y Julieta Fierro, Galileo para Maestros I Correo del Maestro, Núm. 133, p. 15-26, Anios 12, Junio 2007. Hector Dominguez y Julieta Fierro, Galileo para Maestros II Correo del Maestro, Núm. 134, p. 17-26, Anio 12, 2007. Hector Dominguez y Julieta Fierro, Galileo para Maestros III Correo del Maestro, Num. 135, p. 10-18, Anio 12, 2007. Hector Dominguez y Julieta Fierro Experimentos sobre la caida de los cuerpos El Correo del Maestro, anio 12 Numero 142, p. 5-18, 2008. Mariana Espinosa, Julieta Fierro y Silvia Torres Fiesta de estrellas El Correo del Maestro, aceptado para su publicacion.

La serie audiovisual de la colección zuliana: alternativa para la preservación y reconstrucción del patrimonio e identidad del estado Zulia

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Egla Ortega González

2006-05-01

Full Text Available Se analiza la pertinencia del documental como opción para la preservación y divulgación de la identidad zuliana con base a los planteamientos teóricos de Biiri, García Espinosa, Flaherty, Calónico, Getino y Solanas. Igualmente se reflexiona sobre la necesidad de concebir este género cinematográfico de una forma mucho más reflexiva y abierta a las mltiples alternativas de narración, estilo y estructura, más allá de las convenciones mediáticas que lo han limitado y que niegan sus posibilidades dramáticas y estéticas en la reconstrucción y expresión de la cultura y el imaginario. Así mismo, a través de los planteamientos de Urrusti, Altamirano, Morales y Ortega se identifica y reafirma la importancia del testimonio audiovisual en el proceso de desarrollo de colecciones en las organizaciones documentales. Se puntualizan los criterios en el abordaje metodológico de los registros audiovisuales insertados en la Serie Audiovisual de la Colección Zuliana (SACZ. Entre las conclusiones se destaca la relevancia del relato audiovisual en la difusión histórica al preservar en el tiempo los eventos que marcan hito en la construcción y reconstrucción de la sociedad zuliana y se recalca que la circulación de los documentales generados en la SACZ reforzarán el diálogo intercultural, la comprensión y el conocimiento recíproco entre culturas latinoamericanas.

Foraging behaviour of the exotic wasp Vespula germanica (Hymenoptera: Vespidae) on a native caterpillar defoliator.

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Pietrantuono, A L; Moreyra, S; Lozada, M

2017-09-19

Vespula germanica is a social wasp and an opportunistic predator. While foraging, these wasps learn and integrate different kinds of cues. They have successfully invaded many parts of the world, including native Nothofagus and Lophozonia forests located in the Andean-Patagonian region, where they forage on native arthropods. Perzelia arda, a lepidopteron defoliator of Lophozonia obliqua, uses the foliage to hide in and feed on. The purpose of this work is to study whether V. germanica use olfactory cues when foraging on P. arda. To do this, we used a Y-tube olfactometer and established three treatments to compare pairs of all combinations of stimuli (larvae, leaves with larval traces, and leaves without larval traces) and controls. Data were analysed via two developed models that showed decisions made by V. germanica and allowed to establish a scale of preferences between the stimuli. The analysis demonstrates that V. germanica wasps choose P. arda as larval prey and are capable of discriminating between the offered stimuli (deviance information criterion (DIC) null model = 873.97; DIC simple model = 84.5, n = 152). According to the preference scale, V. germanica preferred leaves with traces of larvae, suggesting its ability to associate these traces with the presence of the prey. This may be because, under natural conditions, larvae are never exposed outside their shelters of leaves and therefore V. germanica uses indirect signals. The presence of V. germanica foraging on P. arda highlights the flexible foraging behaviour of this wasp which may also act as a positive biological control, reducing lepidopteran populations.

The determinants of the antibiotic resistance process

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Beatriz Espinosa Franco

2009-04-01

Full Text Available Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM, Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community.Objectives: To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem.Methods: We conducted a MedLine search using the key words “determinants”, “antibiotic”, and “antibiotic resistance” to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded.Results: The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance.Conclusions: Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.Keywords: antibiotic drug resistance

[Risk factors for bladder injuries during cesarean section].

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Alcocer Urueta, Jaime; Bonilla Mares, Marcela; Gorbea Chávez, Viridiana; Velázquez Valassi, Beatriz

2009-01-01

To identify risk factors for bladder injury during cesarean delivery, to let patients and doctors know them and their importance. We conducted a case-control study of women undergoing cesarean delivery at the Instituto Nacional de PerinatologíaIsidro Espinosa de los Reyes between January 2001 and December 2007. Cases were women with bladder injuries at the time of cesarean section. Two controls per case were selected randomly. Medical records were reviewed for clinical and demographic data to compare them. Twenty-one bladder injuries were identified among 24, 057 cesarean sections, (incidence 0.087%), only 19 were analized. Prior cesarean section was more prevalent among cases than controls (63% vs 42% p 0.134), with an OR of 2.35 (95% CI 0.759-7.319), when we take only patients with one cesarea in contrast with no cesarea the OR is 3.75 (95% CI 1.002- 14.07). Statistically significant differences (P values < .05) between cases and controls were found in gestacional age (38.16 vs 37.35 weeks), prior cesareans (42% vs 18%), adhesions (79% vs 5%), Odds ratio of 67.5 (95% CI 11.14- 408), VBAC (31.5 vs 3%), median skin incisión (16% vs 68%), Pfannenstiel (84% vs 32%), blood loss (744cc vs 509cc) and length of surgery 135 vs 58 minutes). No differences were found among age, BMI, prior surgery, labor, premature rupture of membranes, station, chorioamnioitis, induction, uterine incision, timing of delivery, uterine rupture. Prior cesarean section and adhesions are risk factors for bladder injury at the time of repeat cesarean delivery. Elective cesarean delivery is valid but it is duty of physicians to inform patients the risks of it.

Epitaxially influenced boundary layer model for size effect in thin metallic films

International Nuclear Information System (INIS)

Bazant, Zdenek P.; Guo Zaoyang; Espinosa, Horacio D.; Zhu Yong; Peng Bei

2005-01-01

It is shown that the size effect recently observed by Espinosa et al., [J. Mech. Phys. Solids51, 47 (2003)] in pure tension tests on free thin metallic films can be explained by the existence of a boundary layer of fixed thickness, located at the surface of the film that was attached onto the substrate during deposition. The boundary layer is influenced by the epitaxial effects of crystal growth on the dislocation density and texture (manifested by prevalent crystal plane orientations). This influence is assumed to cause significantly elevated yield strength. Furthermore, the observed gradual postpeak softening, along with its size independence, which is observed in short film strips subjected to pure tension, is explained by slip localization, originating at notch-like defects, and by damage, which can propagate in a stable manner when the film strip under pure tension is sufficiently thin and short. For general applications, the present epitaxially influenced boundary layer model may be combined with the classical strain-gradient plasticity proposed by Gao et al., [J. Mech. Phys. Solids 47, 1239 (1999)], and it is shown that this combination is necessary to fit the test data on both pure tension and bending of thin films by one and the same theory. To deal with films having different crystal grain sizes, the Hall-Petch relation for the yield strength dependence on the grain size needs to be incorporated into the combined theory. For very thin films, in which a flattened grain fills the whole film thickness, the Hall-Petch relation needs a cutoff, and the asymptotic increase of yield strength with diminishing film thickness is then described by the extension of Nix's model of misfit dislocations by Zhang and Zhou [J. Adv. Mater. 38, 51 (2002)]. The final result is a proposal of a general theory for strength, size effect, hardening, and softening of thin metallic films

Epitaxially influenced boundary layer model for size effect in thin metallic films

Science.gov (United States)

Bažant, Zdeněk P.; Guo, Zaoyang; Espinosa, Horacio D.; Zhu, Yong; Peng, Bei

2005-04-01

It is shown that the size effect recently observed by Espinosa et al., [J. Mech. Phys. Solids51, 47 (2003)] in pure tension tests on free thin metallic films can be explained by the existence of a boundary layer of fixed thickness, located at the surface of the film that was attached onto the substrate during deposition. The boundary layer is influenced by the epitaxial effects of crystal growth on the dislocation density and texture (manifested by prevalent crystal plane orientations). This influence is assumed to cause significantly elevated yield strength. Furthermore, the observed gradual postpeak softening, along with its size independence, which is observed in short film strips subjected to pure tension, is explained by slip localization, originating at notch-like defects, and by damage, which can propagate in a stable manner when the film strip under pure tension is sufficiently thin and short. For general applications, the present epitaxially influenced boundary layer model may be combined with the classical strain-gradient plasticity proposed by Gao et al., [J. Mech. Phys. Solids 47, 1239 (1999)], and it is shown that this combination is necessary to fit the test data on both pure tension and bending of thin films by one and the same theory. To deal with films having different crystal grain sizes, the Hall-Petch relation for the yield strength dependence on the grain size needs to be incorporated into the combined theory. For very thin films, in which a flattened grain fills the whole film thickness, the Hall-Petch relation needs a cutoff, and the asymptotic increase of yield strength with diminishing film thickness is then described by the extension of Nix's model of misfit dislocations by Zhang and Zhou [J. Adv. Mater. 38, 51 (2002)]. The final result is a proposal of a general theory for strength, size effect, hardening, and softening of thin metallic films.

Experimental and theoretical investigation of topological and energetic characteristics of Sb complexes reversibly binding molecular oxygen.

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Fukin, Georgy K; Baranov, Evgenii V; Jelsch, Christian; Guillot, Benoît; Poddel'sky, Andrey I; Cherkasov, Vladimir K; Abakumov, Gleb A

2011-07-28

The experimental distribution of electron density in Ph(3)(4,5-OMe-3,6-Bu(t)-Cat)Sb·MeCN (1*) and Ph(3)(4,5-N(2)C(4)H(6)-3,6-Bu(t)-Cat)Sb·MeOH (2*) complexes was studied. According to atoms in molecules theory, the Sb-C(Ph), Sb-O(catecholate), and Sb···N(O) bonds are intermediate, whereas the O-C and C-C bonds are covalent, respectively. The energy of the Sb···N(MeCN) and Sb···O(MeOH) bonds are 7.0 and 11.3 kcal/mol according to the Espinosa equation. Density functional theory and Hartree-Fock calculations were carried out for a series of catecholate and amidophenolate complexes of antimony(V). It was shown that such calculations reliably reproduce geometrical and topological parameters and therefore can be used for a criterion search of dioxygen reversible binding by the catecholate and amidophenolate complexes of antimony(V). It was found that the "critical" value of the HOMO energy vary in the range from -5.197 to -5.061 eV for reversible binding of dioxygen complexes. This can serve as a thermodynamic criterion to predict the possibility of the dioxygen reversible binding by the catecholate and amidophenolate complexes of Sb(V). The HOMO energies correlate with the conversion of the catecholate and amidophenolate complexes in corresponding spiroendoperoxide derivatives as well. The contribution of the atom orbitals of the carbon atoms in the five-membered metallocycle to HOMO in complexes with different substitutes in the 4- and 5-positions of the catecholate ligand allows predicting the place of dioxygen addition. © 2011 American Chemical Society

Review of atmospheric metallic elements in Asia during 2000-2004

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Fang, Guor-Cheng; Wu, Yuh-Shen; Huang, Shih-Han; Rau, Jui-Yeh

Metallic element transfer through the atmosphere is a significant part of the biogeochemical cycle of these elements. Natural and anthropogenic were two processes which can increase heavy metal concentrations in the atmosphere. Atmospheric particulates, especially secondary anthropogenic fine particles (PM 2.5), have been influence human health. Generally speaking, the total daily mortality increases by approximately 1% for every 10 μg m -3 increase in PM 10 concentration (Lippmann, 1998). This is why the PM 10 and PM 2.5 measurements are included in the US ambient air quality standards (US-EPA, 1987 for PM 10; 1996 for PM 2.5) (Querol et al., 2001). In recent years, since the great efforts made by Taiwan government towards the reduction of O 3 and PM 10 concentrations by controlling the emission rates of local pollutants sources, the frequency of exceeded PSI has gradually decrease the value of 4.9% in 1999 (Taiwan EPA, 2000). Urban populations are exposed to metals in suspended particles and these are often well above natural background levels owing to anthropogenic processes (Espinosa et al., 2002). This results in elevated metal concentrations that can pose an important risk to human health. Understanding emissions from traffic includes identification of the sources, which is also crucial for designing control measures. Road traffic involves numerous potential sources of metals, combustion products from fuel and oil, wear products from tires, brake linings, bearings, coach and road construction materials, and re-suspension of soil and road dust. The different sample collection devices, pretreatment and analysis methods were discussed in this study. The purpose of this study arranges the atmospheric metallic elements investigations in Asia regions. The data obtained here can also help to understand the sources, concentration, phase distribution and health impact of atmospheric metallic elements in Asian countries.

Caracterización del sistema agrosilvopastoril en la Depresión Central de Chiapas

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N. Ramírez-Marcial

2012-01-01

Full Text Available A través de talleres participativos, se analizó la importancia de algunos árboles para el manejo de los sistemas productivos en una comunidad zoque, del municipio de Ocozocuautla de Espinosa, Chiapas (México. En cinco unidades de producción se establecieron al azar tres parcelas concéntricas de 10, 100 y 1,000 m2, para cuantificar, respectivamente, el número de plántulas (individuos menores de un m de altura, juveniles (individuos 10 cm DAP. De 59 especies de árboles presentes en la localidad, se identificaron 28 de ellas en los sistemas silvopastoriles y hasta ocho tipos de uso, siendo la leña el más importante y Acacia pennatula la especie más utilizada. La densidad de plántulas en los potreros fue de 1.05 ± 0.45 ind/m2, la de juveniles (333 ± 11 ind/ha y la de árboles adultos (71 ±6 ind/ha. Para la alimentación del ganado se promueven varios zacates, siendo el brizantha (Brachiaria brizantha el más extendido (92%. En función de la disponibilidad de forraje, los productores permiten el acceso del ganado a áreas arboladas de donde, además, extraen leña, madera y abono. La mayor dominancia de A. pennatula en los potreros se explica por la dispersión del ganado de las semillas de esta especie que, al ser colonizadora de hábitats abiertos, puede establecerse con relativa facilidad y con la menor inversión de mano de obra y en condiciones de baja presión de pastoreo, lo cual acelera el proceso de regeneración del bosque tropical caducifolio.

Validating numerical simulations of snow avalanches using dendrochronology: the Cerro Ventana event in Northern Patagonia, Argentina

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A. Casteller

2008-05-01

Full Text Available The damage caused by snow avalanches to property and human lives is underestimated in many regions around the world, especially where this natural hazard remains poorly documented. One such region is the Argentinean Andes, where numerous settlements are threatened almost every winter by large snow avalanches. On 1 September 2002, the largest tragedy in the history of Argentinean mountaineering took place at Cerro Ventana, Northern Patagonia: nine persons were killed and seven others injured by a snow avalanche. In this paper, we combine both numerical modeling and dendrochronological investigations to reconstruct this event. Using information released by local governmental authorities and compiled in the field, the avalanche event was numerically simulated using the avalanche dynamics programs AVAL-1D and RAMMS. Avalanche characteristics, such as extent and date were determined using dendrochronological techniques. Model simulation results were compared with documentary and tree-ring evidences for the 2002 event. Our results show a good agreement between the simulated projection of the avalanche and its reconstructed extent using tree-ring records. Differences between the observed and the simulated avalanche, principally related to the snow height deposition in the run-out zone, are mostly attributed to the low resolution of the digital elevation model used to represent the valley topography. The main contributions of this study are (1 to provide the first calibration of numerical avalanche models for the Patagonian Andes and (2 to highlight the potential of Nothofagus pumilio tree-ring records to reconstruct past snow-avalanche events in time and space. Future research should focus on testing this combined approach in other forested regions of the Andes.

Insights into intraspecific wood density variation and its relationship to growth, height and elevation in a treeline species.

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Fajardo, A

2018-05-01

The wood economics spectrum provides a general framework for interspecific trait-trait coordination across wide environmental gradients. Whether global patterns are mirrored within species constitutes a poorly explored subject. In this study, I first determined whether wood density co-varies together with elevation, tree growth and height at the within-species level. Second, I determined the variation of wood density in different stem parts (trunk, branch and twigs). In situ trunk sapwood, trunk heartwood, branch and twig densities, in addition to stem growth rates and tree height were determined in adult trees of Nothofagus pumilio at four elevations in five locations spanning 18° of latitude. Mixed effects models were fitted to test relationships among variables. The variation in wood density reported in this study was narrow (ca. 0.4-0.6 g cm -3 ) relative to global density variation (ca. 0.3-1.0 g cm -3 ). There was no significant relationship between stem growth rates and wood density. Furthermore, the elevation gradient did not alter the wood density of any stem part. Trunk sapwood density was negatively related to tree height. Twig density was higher than branch and trunk densities. Trunk heartwood density was always significantly higher than sapwood density. Negative across-species trends found in the growth-wood density relationship may not emerge as the aggregate of parallel intraspecific patterns. Actually, trees with contrasting growth rates show similar wood density values. Tree height, which is tightly related to elevation, showed a negative relationship with sapwood density. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

In the right place at the right time: habitat representation in protected areas of South American Nothofagus-dominated plants after a dispersal constrained climate change scenario.

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Diego Alarcón

Full Text Available In order to assess the effects of climate change in temperate rainforest plants in southern South America in terms of habitat size, representation in protected areas, considering also if the expected impacts are similar for dominant trees and understory plant species, we used niche modeling constrained by species migration on 118 plant species, considering two groups of dominant trees and two groups of understory ferns. Representation in protected areas included Chilean national protected areas, private protected areas, and priority areas planned for future reserves, with two thresholds for minimum representation at the country level: 10% and 17%. With a 10% representation threshold, national protected areas currently represent only 50% of the assessed species. Private reserves are important since they increase up to 66% the species representation level. Besides, 97% of the evaluated species may achieve the minimum representation target only if the proposed priority areas were included. With the climate change scenario representation levels slightly increase to 53%, 69%, and 99%, respectively, to the categories previously mentioned. Thus, the current location of all the representation categories is useful for overcoming climate change by 2050. Climate change impacts on habitat size and representation of dominant trees in protected areas are not applicable to understory plants, highlighting the importance of assessing these effects with a larger number of species. Although climate change will modify the habitat size of plant species in South American temperate rainforests, it will have no significant impact in terms of the number of species adequately represented in Chile, where the implementation of the proposed reserves is vital to accomplish the present and future minimum representation. Our results also show the importance of using migration dispersal constraints to develop more realistic future habitat maps from climate change predictions.

Diversidad de musgos en ambientes degradados sujetos a restauración en el Parque Nacional Lago Puelo (Chubut, Argentina Moss diversity in degraded environments under restoring in the Lago Puelo National Park (Chubut, Argentina

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ADRIANA E ROVERE

2011-12-01

Full Text Available La restauración ecológica es una disciplina que intenta recuperar atributos perdidos en un ecosistema (diversidad de especies, estructura y función. El objetivo de este trabajo fue evaluar la diversidad de musgos y sus formas de vida en tres ambientes con diferentes niveles de degradación y los sustratos en los que estos se desarrollan. El área de estudio corresponde a un sector que se está restaurando dentro de la Reserva Nacional Lago Puelo. En ella se encuentran tres ambientes distintos: (1 área remanente de bosque maduro de Nothofagus dombeyi, (2 bosque secundario de Austrocedrus chilensis, y (3 matorral dominado por especies exóticas. Se recorrió cada uno de los ambientes, registrando los sustratos con musgos, formas de vida y géneros. Los resultados evidencian una reducción de los sustratos disponibles y de las especies presentes conforme avanza el grado de alteración, desde el área de bosque maduro de N. dombeyi (9 sustratos: 17 géneros: 7 formas de vida, al sector de bosque secundario de A. chilensis (6 sustratos: 8 géneros: 5 formas de vida, siendo menor en el matorral dominado por especies exóticas (1 sustrato: 4 géneros: 3 formas de vida. Los musgos desempeñan funciones importantes en los ecosistemas, son fundamentales en el balance hídrico, pioneros en suelos inestables controlando la erosión y colonizando sitios alterados, sirven como hábitat y alimento para invertebrados, y también constituyen sitios propicios para la germinación de plantas vasculares. Si bien algunas especies leñosas ven afectada su germinación por la presencia de musgos, estos facilitan la germinación de otras especies arbóreas de los bosques templados. Los resultados podrían ser utilizados en restauración, ya sea recreando los sustratos ausentes o realizando traslado de sustratos con musgos, a fin de favorecer la recuperación de áreas boscosas degradadas considerando la biodiversidad original.Ecological restoration is a discipline

Descomposición de hojarasca de Pinus radiata y tres especies arbóreas nativas Decomposition of leaf litter of Pinus radiata and three native tree species

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CHRISTOPHER H. LUSK

2001-09-01

Full Text Available En el centro-sur de Chile, las últimas décadas han sido testigo de una conversión masiva de bosques, matorrales y tierras agrícolas a plantaciones de árboles exóticos. Aunque se ha estudiado la influencia de dichos cambios sobre el balance hídrico, los posibles efectos sobre otros procesos ecosistémicos han recibido poca atención. En esta breve comunicación se presentan datos de un estudio de la descomposición de hojarasca de Pinus radiata y tres especies arbóreas nativas, llevado a cabo con el fin de explorar los posibles efectos del reemplazo de bosque nativo por plantaciones exóticas sobre el ciclaje de nutrientes. Se incubaron muestras de las cuatro especies en dos ambientes distintos en sitios colindantes: bajo un bosque nativo secundario, y bajo un rodal de P. radiata. Se registró la pérdida de peso seco después de dos meses y seis meses. Las tasas diarias de descomposición fueron mucho mayores durante los primeros dos meses de incubación que durante los cuatro meses subsiguientes. En ambas fechas hubo diferencias significativas entre las especies y entre los sitios: todas las especies presentaron mayores tasas de descomposición bajo P. radiata que bajo el bosque nativo. No hubo evidencia de interacción entre sitio y especie. Después de seis meses, el orden de pérdida de peso seco fue Nothofagus obliqua > P. radiata > Peumus boldus > Cryptocarya alba. La variación interespecífica en la tasa de descomposición presentó más relación con el área foliar específica que con el contenido de nitrógeno en la hojarasca. Dado que la hojarasca de P. radiata se descompuso más lentamente que la de la especie caducifolia N. obliqua, pero más rápidamente que las especies esclerófilas, los efectos de la sustitución o invasión sobre descomposición dependerían de la composición original del bosque nativo en cuestiónRecent decades have seen widespread conversion of native forests, shrublands and farmland in south

Lichen Persistence and Recovery in Response to Varied Volcanic Disturbances

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Nelson, P.; Wheeler, T. B.

2015-12-01

Volcanic eruptions produce many ecological disturbances that structure vegetation. While lichens are sensitive to disturbances, little is known about their responses to volcanic disturbances, except for colonization of lava. We examined lichen community responses through time to different disturbances produced by the May 1, 2008 eruption of Volcan Chaiten in south-central Chile. Pre-eruption vegetation near the volcano was old-growth Valdivian temperate rainforest dominated by closed-canopy Nothofagus sp... In 2012, we installed thirteen 1-acre plots across volcanic disturbance zones on which a time-constrained search was done for all macrolichen species, each of which was assigned an approximate log10 categorical abundance. We also installed a 0.2 m2 quadrat on two representative trees per plot for repeat photography of lichen cover. We remeasured at least one plot per disturbance zone in 2014 and re-photographed tree quadrats in 2013 and 2014. We then analyzed species composition and abundance differences among disturbance zones. In 2012, the blast (pyroclastic density flow), scorch (standing scorched forest at the edge of the blast) and deep tephra (>10 cm) zones had the lowest lichen species richness (5-13 species), followed by reference (unimpacted) and shallow (lichen species since 2012 while the light tephra and reference were essentially unchanged. Gravel rain, gravel rain + pumice and flooded forest plots all had about the same number of species in 2014 as 2012. Lichen colonization and growth in tree quadrats varied widely, from very little colonization in the blast to prolific colonization in the gravel rain + pumice zone. Lichen's varied responses to different volcanic disturbances were attributable to varying degrees of mortality and subsequent availability of substrate, quantity of light and removal of competitors. While sensitive to disturbance, lichens are apparently resilient to and can quickly recolonize after a variety of large, violent volcanic

Eocene age of the Baranowski Glacier Group at Red Hill, King George Island, West Antarctica

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Mozer Anna

2015-12-01

Full Text Available Radiometric and geochemical studies were carried out at Red Hill in the southern part of King George Island (South Shetland Islands, northern Antarctic Peninsula on the Bransfield Strait coast. The rock succession at Red Hill has been determined to represent the Baranowski Glacier Group that was previously assigned a Late Cretaceous age. Two formations were distinguished within this succession: the lower Llano Point Formation and the upper Zamek Formation. These formations have stratotypes defined further to the north on the western coast of Admiralty Bay. On Red Hill the Llano Point Formation consists of terrestrial lavas and pyroclastic breccia; the Zamek Formation consist predominantly of fine to coarse tuff, pyroclastic breccia, lavas, tuffaceous mud-, silt-, and sandstone, locally conglomeratic. The lower part of the Zamek Formation contains plant detritus (Nothofagus, dicotyledonous, thermophilous ferns and numerous coal seams (vitrinitic composition that confirm the abundance of vegetation on stratovolcanic slopes and surrounding lowlands at that time. Selected basic to intermediate igneous rocks from the succession have been analysed for the whole-rock K-Ar age determination. The obtained results indicate that the Red Hill succession was formed in two stages: (1 from about 51–50 Ma; and (2 46–42 Ma, i.e. during the Early to Middle Eocene. This, in combination with other data obtained from other Baranowski Glacier Group exposures on western coast of Admiralty Bay, confirms the recently defined position of the volcano-clastic succession in the stratigraphic scheme of King George Island. The new stratigraphic position and lithofacies development of the Red Hill succession strongly suggest its correlation with other Eocene formations containing fossil plants and coal seams that commonly occur on King George Island.

High-resolution coproecology: using coprolites to reconstruct the habits and habitats of New Zealand's extinct upland moa (Megalapteryx didinus.

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Jamie R Wood

Full Text Available Knowledge about the diet and ecology of extinct herbivores has important implications for understanding the evolution of plant defence structures, establishing the influences of herbivory on past plant community structure and composition, and identifying pollination and seed dispersal syndromes. The flightless ratite moa (Aves: Dinornithiformes were New Zealand's largest herbivores prior to their extinction soon after initial human settlement. Here we contribute to the knowledge of moa diet and ecology by reporting the results of a multidisciplinary study of 35 coprolites from a subalpine cave (Euphrates Cave on the South Island of New Zealand. Ancient DNA analysis and radiocarbon dating revealed the coprolites were deposited by the extinct upland moa (Megalapteryx didinus, and span from at least 6,368±31 until 694±30 (14C years BP; the approximate time of their extinction. Using pollen, plant macrofossil, and ancient DNA analyses, we identified at least 67 plant taxa from the coprolites, including the first evidence that moa fed on the nectar-rich flowers of New Zealand flax (Phormium and tree fuchsia (Fuchsia excorticata. The plant assemblage from the coprolites reflects a highly-generalist feeding ecology for upland moa, including browsing and grazing across the full range of locally available habitats (spanning southern beech (Nothofagus forest to tussock (Chionochloa grassland. Intact seeds in the coprolites indicate that upland moa may have been important dispersal agents for several plant taxa. Plant taxa with putative anti-browse adaptations were also identified in the coprolites. Clusters of coprolites (based on pollen assemblages, moa haplotypes, and radiocarbon dates, probably reflect specimens deposited at the same time by individual birds, and reveal the necessity of suitably large sample sizes in coprolite studies to overcome potential biases in diet interpretation.

Improvement of isotope-based climate reconstructions in Patagonia through a better understanding of climate influences on isotopic fractionation in tree rings

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Lavergne, Aliénor; Daux, Valérie; Villalba, Ricardo; Pierre, Monique; Stievenard, Michel; Srur, Ana Marina

2017-02-01

Very few studies of stable isotopes exist across the Andes in South America. This study is the first presenting annually resolved chronologies of both δ18 O and δ13 C in Nothofagus pumilio and Fitzroya cupressoides trees from Northern Patagonia. Interannual variability in δ18 O and δ13 C was assessed over the period 1952-2011. Based on these chronologies, we determined the primary climatic controls on stable isotopes and tree physiological responses to changes in atmospheric CO2 concentrations (ca), temperature and humidity. Changes in specific intrinsic water use efficiency (iWUE) were inferred from variations in δ13 C whereas the effects of CO2 increase on stomatal conductance were explored using δ18 O. Over the 60-year period, iWUE increased significantly (by ca. 25%) in coincidence with the rise of ca. The two species appear to have different strategies of gas-exchange. Whereas iWUE variations were likely driven by both stomatal conductance and photosynthetic assimilation rates in F. cupressoides, they were largely related to stomatal conductance in N. pumilio. After removing the low-frequency trends related to increasing ca, significant relationships between δ13 C and summer temperatures were recorded for both species. However, δ13 C variations in F. cupressoides were more strongly influenced by summer temperatures than in N. pumilio. Our results advocate for an indirect effect of summer temperatures on stable isotope ratios, which is mostly influenced by sunlight radiation in F. cupressoides and relative humidity/soil moisture in N. pumilio. δ13 C variations in F. cupressoides were spatially correlated to a large area south of 35°S in southern South America. These promising results encourage the use of δ13 C variations in F. cupressoides for reconstructing past variations in temperature and large-scale circulation indexes such as the Southern Annular Mode (SAM) in the Southern Hemisphere.

Deglacial palaeoclimate at Puerto del Hambre, subantarctic Patagonia, Chile

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Heusser, Calvin J.; Heusser, Linda E.; Lowell, Thomas V.; Moreira M., Andrés; Moreira M., Simón

2000-02-01

The primary objective of this study is to further substantiate multistep climatic forcing of late-glacial vegetation in southern South America. A secondary objective is to establish the age of deglaciation in Estrecho de Magallanes-Bahía Inútil. Pollen assemblages at 2-cm intervals in a core of the mire at Puerto del Hambre (53°3621S, 70°5553W) provide the basis for reconstructing the vegetation and a detailed account of palaeoclimate in subantarctic Patagonia. Chronology over the 262-cm length of core is regulated by 20 AMS radiocarbon dates between 14 455 and 10 089 14C yr BP. Of 13 pollen assemblage zones, the earliest representing the Oldest Dryas chronozone (14 455-13 000 14C yr BP) records impoverished steppe with decreasing frequencies and loss of southern beech (Nothofagus). Successive 100-yr-long episodes of grass/herbs and of heath (Empetrum/Ericaceae) before 14 000 14C yr BP infer deglacial successional communities under a climate of increased continentality prior to the establishment of grass-dominated steppe. The Bølling-Allerød (13 000-11 000 14C yr BP) is characterised by mesic grassland under moderating climate that with abrupt change to heath dominance after 12 000 14C yr BP was warmer and not as humid. At the time of the Younger Dryas (11 000-10 000 14C yr BP), grass steppe expanded with a return of colder, more humid climate. Later, with gradual warming, communities were invaded by southern beech. The Puerto del Hambre record parallels multistep, deglacial palaeoclimatic sequences reported elsewhere in the Southern Andes and at Taylor Dome in Antarctica. Deglaciation of Estrecho de Magallanes-Bahía Inútil is dated close to 14 455 14C yr BP, invalidating earlier dates of between 15 800 and 16 590 14C yr BP.

Targeting PD-1/PD-L1 in lung cancer: current perspectives

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González-Cao M

2015-07-01

Full Text Available María González-Cao,1 Niki Karachaliou,1 Santiago Viteri,1 Daniela Morales-Espinosa,1 Cristina Teixidó,2 Jesús Sánchez Ruiz,3 Miquel Ángel Molina-Vila,2 Mariacarmela Santarpia,4 Rafael Rosell1,2,5,61Translational Cancer Research Unit, Instituto Oncológico Dr Rosell, Quirón Dexeus University Hospital, Barcelona, Spain; 2Pangaea Biotech SL, Barcelona, Spain; 3Centro Nacional de Investigación Oncología (CNIO, Madrid, Spain; 4Medical Oncology Unit, Human Pathology Department, University of Messina, Messina, Italy; 5Cancer Biology and Precision Medicine Program, Catalan Institute of Oncology, Germans Trias i Pujol Health Sciences Institute and Hospital, Campus Can Ruti, Badalona, Barcelona, Spain; 6Fundación Molecular Oncology Research, Barcelona, SpainAbstract: Increased understanding of tumor immunology has led to the development of effective immunotherapy treatments. One of the most important advances in this field has been due to pharmacological design of antibodies against immune checkpoint inhibitors. Anti-PD-1/PD-L1 antibodies are currently in advanced phases of clinical development for several tumors, including lung cancer. Results from Phase I–III trials with anti-PD-1/PD-L1 antibodies in non-small-cell lung cancer have demonstrated response rates of around 20% (range, 16%–50%. More importantly, responses are long-lasting (median duration of response, 18 months and fast (50% of responses are detected at time of first tumor evaluation with very low grade 3–4 toxicity (less than 5%. Recently, the anti-PD-1 antibody pembrolizumab received US Food and Drug Administration (FDA breakthrough therapy designation for treatment of non-small-cell lung cancer, supported by data from a Phase Ib trial. Another anti-PD-1 antibody, nivolumab, has also been approved for lung cancer based on survival advantage demonstrated in recently released data from a Phase III trial in squamous cell lung cancer.Keywords: immunotherapy, immunoncology

Periodicity and repeatability in data

Science.gov (United States)

Southwood, D.

Using magnetic data from the first two years in Saturn orbit, the basic periodicity of apparent is examined with the aim of elucidating the `cam' shaft model of Espinosa et al. (2003) identifying the nature of the `cam' and giving a definitive period for its rotation. An initial hypothesis, supported by the spectral analysis of analysis of the first 8 months in orbit Gianpieri et al. (2006), is made that the source of the period is linked to something inside the planet and therefore that the source inertia means that the period effectively does not change over the 2 years. Moreover one expects that the source phase is fixed. Using this approach, not only can the period identified by spectral analysis (647.1 + 0.6 min.) be verified but also by phase analysis between successive passes over the 2 years the period can be refined to 647.6 + 0.1 min. The signal itself is remarkably reproducible from pass to pass. It appears in all three components of the field and its polarisation is unambiguously not attributable to direct detection of an internal field. Not only does the signal not decay rapidly with distance from the planet, but although it has the m=1 symmetry of a tilted dipole, the field lines diverge from the planet indicating an exterior source. This feature led to the `cam' model. The polarisation and comparisons of passes with different latitude profiles show a surprising north-south symmetry in the azimuthal field. The absence of asymmetry with respect to the magnetic equator rules out a direct magnetospheric-ionospheric interaction source. Accordingly, it is proposed that the basic `cam' effect is generated by a single hemisphere anomaly which creates hemisphere to hemisphere field aligned currents. The existence of Saturn phase related anomaly appears to produce a basic asymmetry in the inner magnetosphere that sets the phase of both an inflowing and outflowing sector in a rotating circulation system.

Science.gov (United States)

Angulo Tabernero, Marina; Suñén Sánchez, Enrique; Peña Jiménez, Diego; Loste Ramos, Antonio; Tabuenca Sánchez, Antonio; Chárlez Marco, Alfredo; Rodríguez Vela, Javier

2018-02-20

Las lesiones traumáticas de la columna cervical son infrecuentes en los niños, representando el 1% de las fracturas pediátricas y el 2% de todas las lesiones raquídeas.Es importante conocer que la columna cervical en la infancia presenta variaciones anatómicas que en ocasiones pueden interpretarse como patológicas ya que en los niños una adecuada exploración física muchas veces puede ser complicada.El objetivo de este caso clínico es mostrar un hallazgo radiológico fisiológico de la columna cervical infantil que tiende a ser malinterpretado como patológico: la pseudosubluxación C2-C3.Se presenta un caso de un niño de 5 años de edad que acude a urgencias de traumatología pediátrica de nuestro centro por dolor cervical tras caída desde un tobogán. Se realizan radiografías cervicales de urgencias observando una disrupción de la línea cervical anterior y posterior entre C2 y C3. Una adecuada anamnesis junto con un meticuloso examen clínico y radiológico permite su correcto diagnostico sin necesidad de otras pruebas complementarias. La pseudoluxación anterior de C2 sobre C3 se puede estar presente en el 40% de los niños menores de 8 años. Este hallazgo puede diferenciarse de la luxación traumatic valorando la línea espinolaminar o línea de Swischuk, línea entre el borde anterior de las apófisis espinosas de C1 a C3. La interpretación adecuada de las radiografías de la columna cervical en la infancia requiere del conocimiento de estas variantes radiológicas y de las peculiares características de este segmento vertebral en la edad pediátrica.

[The strategic purchasing of health services: a big opportunity for the National Universal Health System].

Science.gov (United States)

González-Block, Miguel Ángel; Alarcón Irigoyen, José; Figueroa Lara, Alejandro; Ibarra Espinosa, Ignacio; Cortés Llamas, Noemí

2015-01-01

proposed to establish a service packages, whether through a single obligatory list or through the definition of a flexible, high priority set to be offered to specific populations according to their economic possibilities. For the strategic purchasing of services, two alternatives are proposed: to assign the fund either to a single national manager or to each of the existing public provider institutions, with the expectation that they would contract across each other and with private providers to fulfill their complementary needs.The proposal does not consider the risks and alternatives to a single tax contribution fund, which could have been suggested given that it is not an essential part of a National Universal Health System. However, it is necessary to discuss in more detail the roles and strategies for a national single-payer, especially for the strategic purchasing of high-cost and specialized interventions in the context of public and private providers. The alternative of allocating funds directly to providers would undermine the incentives for competition and collaboration and the capacity to steer providers towards the provision of high quality health services.It is proposed to focus the discussion of the reform of the national health system around strategic purchasing and the functions and structure of a single-payer as well as of agencies to articulate integrated health service networks as tools to promote quality and efficiency of the National Universal Health System. The inclusion of economic incentives to providers will be vital for competition, but also for the cooperation of providers within integrated, multi-institutional health service networks.Health professionals and sector policy specialists coordinated by the Centro de Estudios Espinosa Yglesi as in Mexico propose a policy to anchor the health system in primary care centered on the individual. The vision includes effective stewardship,solid financing, and the provision of services by a

Efectos de la variación temporal y los métodos de captura en la eficiencia de un muestreo de coleópteros en la Reserva Natural Loma del Medio, El Bolsón, Río Negro Effects of temporal variation and trapping methods on the efficiency of Coleoptera sampling in Loma del Medio Nature Reserve, El Bolsón, Río Negro

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Paula Sackmann

2006-12-01

Full Text Available En este trabajo se analiza la eficiencia de un muestreo sistemático para una comunidad de coleópteros de bosque subantártico. En particular se evalúa: 1- la conveniencia de repartir el esfuerzo de muestreo a lo largo del tiempo (dentro de una misma temporada de actividad de insectos y entre años, y 2- la eficiencia del uso de dos tipos de trampas diferentes. Se seleccionaron 10 sitios en un bosque de Austrocedrus chilensis (Cupresaceae y Nothofagus dombeyii (Fagaceae en la Reserva Forestal Loma del Medio, El Bolsón, Río Negro. En cada sitio se colocaron nueve trampas de caída que abarcaban una superficie de 100 m² y una trampa Malaise. Se realizaron cuatro muestreos anuales (enero, febrero, marzo y abril durante tres años (2002-2004, y de una semana de duración cada uno. La abundancia de especies fue mayor en enero-febrero que en marzo-abril, la riqueza fue similar y la composición de la comunidad fue marcadamente distinta entre dichos períodos para los tres años. Por otro lado, la riqueza de especies fue similar al considerar uno, dos o tres años de muestreo, y en general la composición de la comunidad no varió entre años para períodos comparables. Sin embargo, la acumulación de especies raras sólo se estabilizó luego de tres años de muestreo. Aunque las trampas Malaise fueron más eficientes (número de especies observadas / individuos capturados que las trampas de caída, los métodos de captura fueron altamente complementarios (25% de especies en común. Para caracterizar esta comunidad en particular, se recomienda distribuir el esfuerzo de muestreo a lo largo de una misma temporada de actividad y aplicar diferentes métodos de muestreos. Con un año de muestreo, bajo las condiciones propuestas anteriormente, se podrá caracterizar la comunidad de forma general, pero hacen falta al menos tres años de muestreo para alcanzar un alto grado de integridad. Se incluye un apéndice con la lista de especies capturadas (N

Limitantes físicos y bióticos de la regeneración arbórea en matorrales sucesionales de la Isla Grande de Chiloé, Chile Physical and biotic constraints on tree regeneration in secondary shrublands of Chiloé Island, Chile

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MARÍA F DÍAZ

2007-03-01

Full Text Available Los matorrales sucesionales establecidos después de la corta y quema de bosques son frecuentes en Chiloé y territorios continentales vecinos. Estos sitios son dominados por arbustos de Baccharis patagonica, musgos en cojín del género Sphagnum, plantas palustres y helechos. En estos sitios hemos registrado escasa o nula colonización arbórea (Successional shrublands created by clearcutting and burning of forests are frequent in Chiloé Island and surrounding mainland in southern Chile. These areas are characterized by seasonally waterlogged soils, and vegetation dominated by sedges, ferns and shrubs, such as Baccharis patagonica, with thick carpets of Sphagnum moss occupying the spaces between shrubs. Tree regeneration in these sites was shown to be sparse or completely lacking (< 0.3 seedlings m-2 compared with 7.2 seedlings m-2 in adjacent forests. Colonization of shade-intolerant, pioneer trees may be reduced underneath Baccharis due to crown shading and on top of Sphagnum cushions, because of unfavorable conditions for tree establishment, including low pH and soil water saturation. We evaluated differences in germination rates among pioneer tree species grown in an experimental soil moisture gradient. Seed germination percentage was low for Drimys winteri and Nothofagus nitida unrelated to humidity conditions but differed between substrates (moss vs. soil. Embothrium had higher germination and survivorship when growing on Sphagnum cushions. We also monitored seedling survival of two pioneer tree species (Embothrium coccineum and Drimys winteri transplanted directly under Baccharis shrubs, in open areas, or on moss patches. Even though survivorship of Embothrium and Drimys under Baccharis was < 40 %, in one of the study sites, there were no differences between treatments. Waterlogged soils would constraint tree regeneration on successional shrublands due to a lack of elevated substrates. However, the presence of Sphagnum cushions favors

Modelling tree ring cellulose δ18O variations in two temperature-sensitive tree species from North and South America

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A. Lavergne

2017-11-01

Full Text Available Oxygen isotopes in tree rings (δ18OTR are widely used to reconstruct past climates. However, the complexity of climatic and biological processes controlling isotopic fractionation is not yet fully understood. Here, we use the MAIDENiso model to decipher the variability in δ18OTR of two temperature-sensitive species of relevant palaeoclimatological interest (Picea mariana and Nothofagus pumilio and growing at cold high latitudes in North and South America. In this first modelling study on δ18OTR values in both northeastern Canada (53.86° N and western Argentina (41.10° S, we specifically aim at (1 evaluating the predictive skill of MAIDENiso to simulate δ18OTR values, (2 identifying the physical processes controlling δ18OTR by mechanistic modelling and (3 defining the origin of the temperature signal recorded in the two species. Although the linear regression models used here to predict daily δ18O of precipitation (δ18OP may need to be improved in the future, the resulting daily δ18OP values adequately reproduce observed (from weather stations and simulated (by global circulation model δ18OP series. The δ18OTR values of the two species are correctly simulated using the δ18OP estimation as MAIDENiso input, although some offset in mean δ18OTR levels is observed for the South American site. For both species, the variability in δ18OTR series is primarily linked to the effect of temperature on isotopic enrichment of the leaf water. We show that MAIDENiso is a powerful tool for investigating isotopic fractionation processes but that the lack of a denser isotope-enabled monitoring network recording oxygen fractionation in the soil–vegetation–atmosphere compartments limits our capacity to decipher the processes at play. This study proves that the eco-physiological modelling of δ18OTR values is necessary to interpret the recorded climate signal more reliably.

Estado actual del conocimiento de la familia Ceratopogonidae en la Patagonia (Diptera: Nematocera

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Gustavo R. SPINELLI

2009-01-01

Full Text Available Ceratopogonidae incluye pequeños dípteros nematocerosque crían en hábitats acuáticos o semiacuáticos. Hasta los ‘80, el conocimiento de su taxonomía en la Patagonia se hallaba limitado a la contribución de los comienzos de los ‘30 de Ingram y Macfie, sobre la base de material capturado en 1926-27, en el área del Parque Nacional Nahuel Huapi y zonas vecinasde Chile. En los últimos 25 años, se pusieron en marcha diferentes proyectos, resultando la descripción o registro de numerosos taxones para la región. Si se contabilizan los datos publicados, 102 especies habitan en la Patagonia, de las cuales 86 (84,31% son endémicas para la región. Este alto porcentaje es evidente en los bosques de Nothofagus, con 71 especies endémicas de estebioma, nueve lo son de la estepa y seis presentan registros en bosque y estepa. Datos aún no publicados concuerdan con este esquema. Diecinueve géneros están representados en la Patagonia, diez de ellos con amplia distribución,tres de distribución transantártica y seis son endémicos para el área. Para la misma, se hallan publicadas las revisiones de Forcipomyia, Atrichopogon, Borkenthelea, Macrurohelea y Paradasyhelea; se han finalizado y aún no publicado aquellas de Dasyhelea y Palpomyia, está muy avanzada la de Stilobezzia y se prevé comenzar con las de Austrohelea, Austrosphaeromias, Physohelea y Bezzia. Se calcula que estos datos no divulgados contienen al menos 55 especies todavía no descriptas. Con respecto a los aspectos biogeográficos se pueden destacar estudios que tienden a establecer relaciones entre las áreas reconocidas en esquemas biogeográficos propuestos para la región andina.

Antarctotrechus balli sp. n. (Carabidae, Trechini: the first ground beetle from Antarctica

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Allan C. Ashworth

2016-11-01

Full Text Available Fossil elytra of a small trechine carabid are reported from the Oliver Bluffs on the Beardmore Glacier at lat. 85°S. They were compared with counterparts from the extant genera Trechisibus, Tasmanorites, Oxytrechus and Pseudocnides. The fossils share some characters but are sufficiently different to be described as a new genus and species. We named the new species Antarctotrechus balli in honour of George E. Ball who made major contributions to the study of carabids through his own research and the training of students while at the University of Alberta, Edmonton, Alberta, Canada. The closest extant relatives to the extinct A. balli are species of Trechisibus, which inhabit South America, the Falkland Islands and South Georgia, and Tasmanorites, which inhabit Tasmania, Australia. Plant fossils associated with A. balli included Nothofagus (southern beech, Ranunculus (buttercup, moss mats and cushion plants that were part of a tundra biome. Collectively, the stratigraphic relationships and the growth characteristics of the fossil plants indicate that A. balli inhabited the sparsely-vegetated banks of a stream that was part of an outwash plain at the head of a fjord in the Transantarctic Mountains. Other insects represented by fossils in the tundra biome include a listroderine weevil and a cyclorrhaphan fly. The age of the fossils, based on comparison of associated pollen with 40Ar/39Ar dated pollen assemblages from the McMurdo Dry Valleys, is probably Early to Mid-Miocene in the range 14–20 Ma. The tundra biome, including A. balli, became extinct in the interior of Antarctica about 14 Ma and on the margins of the continent by 10–13 Ma. A. balli confirms that trechines were once widely distributed in Gondwana. For A. balli and other elements of the tundra biome it appears they continued to inhabit a warmer Antarctica for many millions of years after rifting of Tasmania (45 Ma and southern South America (31 Ma.

Ignition probability of fine dead surface fuels of native Patagonian forests or Argentina

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Lucas O. Bianchi

2014-04-01

.Keywords: Austrocedrus chilensi; Nothofagus antarctica; wildfire; fire behavior; fuel moisture; fire weather index.

Emission factors of particulate matter, polycyclic aromatic hydrocarbons, and levoglucosan from wood combustion in south-central Chile.

Science.gov (United States)

Jimenez, Jorge; Farias, Oscar; Quiroz, Roberto; Yañez, Jorge

2017-07-01

In south-central Chile, wood stoves have been identified as an important source of air pollution in populated areas. Eucalyptus (Eucalyptus globulus), Chilean oak (Nothofagus oblique), and mimosa (Acacia dealbata) were burned in a single-chamber slow-combustion wood stove at a controlled testing facility located at the University of Concepción, Chile. In each experiment, 2.7-3.1 kg of firewood were combusted while continuously monitoring temperature, exhaust gases, burn rate, and collecting particulate matter samples in Teflon filters under isokinetic conditions for polycyclic aromatic hydrocarbon and levoglucosan analyses. Mean particulate matter emission factors were 2.03, 4.06, and 3.84 g/kg dry wood for eucalyptus, oak, and mimosa, respectively. The emission factors were inversely correlated with combustion efficiency. The mean emission factors of the sums of 12 polycyclic aromatic hydrocarbons in particle phases were 1472.5, 2134.0, and 747.5 μg/kg for eucalyptus, oak, and mimosa, respectively. Fluoranthene, pyrene, benzo[a]anthracene, and chrysene were present in the particle phase in higher proportions compared with other polycyclic aromatic hydrocarbons that were analyzed. Mean levoglucosan emission factors were 854.9, 202.3, and 328.0 mg/kg for eucalyptus, oak, and mimosa, respectively. Since the emissions of particulate matter and other pollutants were inversely correlated with combustion efficiency, implementing more efficient technologies would help to reduce air pollutant emissions from wood combustion. Residential wood burning has been identified as a significant source of air pollution in populated areas. Local wood species are combusted for home cooking and heating, which releases several toxic air pollutants, including particulate matter, carbon monoxide, and polycyclic aromatic hydrocarbons. Air pollutant emissions depend on the type of wood and the technology and operational conditions of the wood stove. A better understanding of emissions from

Performance of large open-top chambers for long-term field investigations of tree response to elevated carbon dioxide concentration

International Nuclear Information System (INIS)

Whitehead, D.; Hogan, K.P.; Rogers, G.N.D.; Byers, J.N.; Hunt, J.E.; McSeveny, T.M.; Hollinger, D.Y.; Dungan, R.J.; Earl, W.B.; Bourke, M.P.

1995-01-01

In preparation for an investigation of the effects of elevated carbondioxide (CO 2 ) concentration on the two tree species Pinus radiata D. Don and Nothofagus fusca (Hook. f. ) Oerst, the environmental conditions inside sixteen open-top chambers, of the design described by Heagle et al. (1989), were measured and compared with those outside. During a period in late summer, both air temperature and air saturation deficit were greater inside the chambers, with mean increases of 0.3 degreesC and 0.1 kPa, respectively. The increases were closely related to solar irradiance, reaching maximum differences for temperature and air saturation deficit of 4.3 degrees C and 0.8 kPa, respectively, when solar irradiance was greater than 1600 mu mol m -2 s -1 . The mean (± standard deviation) CO 2 concentrations for the ambient and elevated treatments were 362 ± 37 and 654 ± 69 mu mol mol -1 , respectively. However, the CO 2 concentration in the elevated treatment decreased as wind speed increased, owing to incursions of ambient air into the chambers. Transmittance of visible solar irradiance (400-700 nm) through the plastic wall material decreased by 7% after 1 year of exposure at the site. In cloudy conditions the mean transmittance of solar irradiance into the chambers was 81% and on clear days this decreased from 80% to 74% with increasing solar zenith angle. The ratio of diffuse to total solar irradiance in the chambers was 13% and 21% greater than that outside for cloudy and clear conditions, respectively. The implications of these differences on water use efficiency for the trees growing inside and outside the chamber are discussed. A cost effective system, built to separate the CO 2 required for the experiment from waste biogas, is described. This project is contributing to the Global Change and Terrestrial Ecosystems (GCTE) Core Research Programme by providing data on the long-term effects of elevated CO 2 concentration on the above and below-ground carbon balance for

LifePrint: a novel k-tuple distance method for construction of phylogenetic trees

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Fabián Reyes-Prieto

2011-01-01

Full Text Available Fabián Reyes-Prieto1, Adda J García-Chéquer1, Hueman Jaimes-Díaz1, Janet Casique-Almazán1, Juana M Espinosa-Lara1, Rosaura Palma-Orozco2, Alfonso Méndez-Tenorio1, Rogelio Maldonado-Rodríguez1, Kenneth L Beattie31Laboratory of Biotechnology and Genomic Bioinformatics, Department of Biochemistry, National School of Biological Sciences, 2Superior School of Computer Sciences, National Polytechnic Institute, Mexico City, Mexico; 3Amerigenics Inc, Crossville, Tennessee, USAPurpose: Here we describe LifePrint, a sequence alignment-independent k-tuple distance method to estimate relatedness between complete genomes.Methods: We designed a representative sample of all possible DNA tuples of length 9 (9-tuples. The final sample comprises 1878 tuples (called the LifePrint set of 9-tuples; LPS9 that are distinct from each other by at least two internal and noncontiguous nucleotide differences. For validation of our k-tuple distance method, we analyzed several real and simulated viroid genomes. Using different distance metrics, we scrutinized diverse viroid genomes to estimate the k-tuple distances between these genomic sequences. Then we used the estimated genomic k-tuple distances to construct phylogenetic trees using the neighbor-joining algorithm. A comparison of the accuracy of LPS9 and the previously reported 5-tuple method was made using symmetric differences between the trees estimated from each method and a simulated “true” phylogenetic tree.Results: The identified optimal search scheme for LPS9 allows only up to two nucleotide differences between each 9-tuple and the scrutinized genome. Similarity search results of simulated viroid genomes indicate that, in most cases, LPS9 is able to detect single-base substitutions between genomes efficiently. Analysis of simulated genomic variants with a high proportion of base substitutions indicates that LPS9 is able to discern relationships between genomic variants with up to 40% of nucleotide

Catch composition of the spiny lobster Panulirus gracilis (Decapoda: Palinuridae off the western coast of Mexico Composición de la captura de la langosta espinosa Panulirus gracilis (Decapoda: Palinuridae en la costa oeste de México

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Raúl Pérez-González

2011-07-01

Full Text Available The lobster fishery in the Gulf of California and the south-central region of the western coast of Mexico consists of small-scale artisanal activity supported by Panulirus gracilis and P. inflatus, with an annual average catch of 132 ton. The present study analyzes the landing composition of this fishery and the population structure of P. gracilis. Carapace lengths (CL for this species ranged from 35 to 125 mm, and the most frequent sizes were between 60 and 85 mm. The size distribution was approximately normal. This implies that the fishery is composed of several size classes, with annual recruitment to the fishing areas. For the 1989-1990 and 1990-1991 fishing seasons, the mean monthly sizes of males were between 70.18 ± 11.74 and 81.11 ± 6.76 mm CL, whereas females averaged from 73.60 ± 8.95 to 80.28 ± 7.53 mm CL. Power-law relationships between carapace length (CL in mm and total weight (TW in g were determined, resulting in the following equations: PT = 0.0021 CL27689 for males and PT = 0.0009 CL³ 0038 for females. During certain periods of the year, males dominated the catch; however, the overall annual male:female ratio was near 1:1.La pesquería de langosta en el golfo de California y en el centro-sur de la costa occidental de México es una actividad artesanal a pequeña escala y es sostenida por Panulirus gracilis y P. inflatus, con una captura promedio anual de 132 ton. En este estudio se analiza la composición de los desembarques de esta pesquería y la estructura de la población de P. gracilis. El intervalo de talla de esta especie fue de 35 a 125 mm de longitud del cefalotórax (LC y el más frecuente se encontró entre 60 y 85 mm. La distribución de tallas fue aproximadamente normal. Esto implica que la pesquería está compuesta por varias clases de tallas, con un reclutamiento anual a las áreas de pesca. La talla media mensual de machos fue entre 70,18 ± 11,74 y 81,11 ± 6,76 mm LC y en hembras de 73,60 ± 8,95 a 80,28 ± 7,53 mm LC, durante las temporadas de pesca 1989-1990 y 1990-1991. Se determinó la relación entre la LC (en mm y el peso total (PT, en g, obteniéndose las siguientes ecuaciones: PT = 0.0021 LC2.7689 en machos y PT = 0.0009LC3.0038 en hembras. Durante ciertos períodos del año los machos son dominantes en las capturas, pero la proporción machos:hembras durante todo el año es cercana a 1:1.

Abiotic alterations caused by forest fragmentation affect tree regeneration: a shade and drought tolerance gradient in the remnants of Coastal Maulino Forest Alteraciones abióticas causadas por la fragmentación del bosque afectan la regeneración arbórea: un gradiente de tolerancia a la sombra y la sequía en los remanentes del Bosque Maulino Costero

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PABLO C GUERRERO

2009-01-01

Full Text Available Plant regeneration is strongly determined by light and soil moisture differences between habitáis; both variables are modified by large-scale forest fragmentation. Several studies have indicated this alteration as the mechanism involved in tropical forest community change. The effects of fragmentation may be much more severe in Mediterranean and deciduous forests, because plant species in these forests show a stress tolerance tradeoff between shade and drought. Our study was performed in the deciduous fragmented Coastal Maulino Forest: Reserva Nacional Los Queules (RNLQ and surrounding small fragments. We hypothesised that Aristotelia chilensis (shade intolerant but drought tolerant should increase its regeneration in small patches as a consequence of the change in habitat suitability (i.e. luminous and drier, while Cryptocarya alba (shade tolerant but drought intolerant should have less regeneration in small fragments. We also expected that Nothofagus glauca and N. obliqua, which have shade and drought tolerances intermedíate between A. chilensis and C. alba, should respond less to forest fragmentation. We used two estimations of plant regeneration: (i seedling and sapling densities via field observations and (ii seed germination and seedling establishment via a field-based experiment. Natural regeneration patterns of C. alba indicated a depressed regeneration within small forest fragments compared to RNLQ, although experimental germination, establishment and recruitment proportions did not vary between habitáis. In contrast, A. chilensis regeneration was favored by forest fragmentation, with increased seedling and sapling densities and germination in small forest fragments. Both N. glauca and N. obliqua were less affected by forest fragmentation in their natural and experimental regeneration. This study highlights the relevance of studying changes in abiotic factors as a consequence of human activities, and considering safe sites (defined

A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego

Energy Technology Data Exchange (ETDEWEB)

Moy, C M; Dunbar, R B; Guilderson, T P; Waldmann, N; Mucciarone, D A; Recasens, C; Austin, J A; Anselmetti, F S

2010-11-19

Situated at the southern margin of the hemispheric westerly wind belt and immediately north of the Antarctic Polar Frontal zone, Tierra del Fuego is well-positioned to monitor coupled changes in the ocean-atmosphere system of the high southern latitudes. Here we describe a Holocene paleoclimate record from sediment cores obtained from Lago Fagnano, a large lake in southern Tierra del Fuego at 55{sup o}S, to investigate past changes in climate related to these two important features of the global climate system. We use an AMS radiocarbon chronology for the last 8,000 years based on pollen concentrates, thereby avoiding contamination from bedrock-derived lignite. Our chronology is consistent with a tephrochronologic age date for deposits from the middle Holocene Volcan Hudson eruption. Combining bulk organic isotopic ({delta}{sup 13}C and {delta}{sup 15}N) and elemental (C and N) parameters with physical sediment properties allow us to better understand sediment provenance and transport mechanisms and to interpret Holocene climate and tectonic change during the last 8,000 years. Co-variability and long-term trends in C/N ratio, carbon accumulation rate, and magnetic susceptibility reflect an overall Holocene increase in the delivery of terrestrial organic and lithogenic material to the deep eastern basin. We attribute this variability to westerly wind-derived precipitation. Increased wind strength and precipitation in the late Holocene drives the Nothofagus forest eastward and enhances run-off and terrigenous inputs to the lake. Superimposed on the long-term trend are a series of abrupt 9 negative departures in C/N ratio, which constrain the presence of seismically-driven mass flow events in the record. We identify an increase in bulk {delta}{sup 13}C between 7,000 and 5,000 cal yr BP that we attribute to enhanced aquatic productivity driven by warmer summer temperatures. The Lago Fagnano {delta}{sup 13}C record shows similarities with Holocene records of sea surface

LA GEOPEDOLOGIA COMO BASE PARA ZONIFICAR LA APTITUD FORESTAL EN UNA CUENCA DEL NOROESTE DE LA PATAGONIA ARGENTINA

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Maria Cristina Frugoni

2016-12-01

Full Text Available Geopedology at a semi-detailed scale (1:50.000 was carried out in Buta Mallín catchment which includes an area of 21.065ha, in the northwest of Neuquén province, Argentine Patagonia. Geopedology provides a spatial dimension of soil-landscape relations, which are displayed in a map and its legend, showing the geoforms (contours and their soils (content, based on the premise that soil is landscape as well as profile. According to this approach three landscapes were recognized: glacial modeled mountains, plateau and valley. The relief consists mainly of steep to very steep slopes, and valley bottoms with poorly drained soils. Lithology (parent material corresponds to holocene volcanic ash in the western sector of the study area, while the eastern sector is dominated by tuff. Twenty terrain forms and their soils were identified. With this basic information, attribute tables were constructed considering landscape and soil properties. Regarding soils, physical fertility properties were considered, since these are the most correlated ones with Pinus ponderosa (pino ponderosa growth, the main species used in afforestation in Patagonia. Those tables were included and analized with a GIS (Geographic Information System to obtain a forest suitability map. The study area shows four forest suitability classes. Suitable: 37ha; moderately suitable: 4.512ha; marginally suitable: 6.072ha; not suitable: 10.444ha. The main limitations of the area are the very steep slopes, height and the areas dominated by rock outcrops and detrital covers. Nothofagus antarctica (ñire shrubs cover part of the suitable areas; because of conservation criteria of these natural communities, these lands were considered not suitable. On the other side, there are more than 4.000 ha of moderately suitable lands, which can be considered for a more detailed study. Transhumant cattle raising is the main land use system in this catchment, which is an ancient culture of the Northern Neuquian

Multiproxy approach revealing climate and cultural changes during the last 26kyrs in south-central Chile

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Abarzua, Ana M.; Jarpa, Leonora; Martel, Alejandra; Vega, Rodrigo; Pino, Mario

2010-05-01

Multiproxy approach from Purén Lumaco Valley (38°S) describes the paleonvironmental history during the Last Maximum Glacial (LGM) in south-central Chile. Three sediment cores and severals AMS 14C dates were used to perform a complete pollen, diatoms, chironomids, and sedimentological records demonstrating the existence of a large and non profundal paleolake, between 25 and 20kyr BP. Some of these evidence are laminated silty-clay sediments (lacustrine rhythmites), associated with the presence of siderite mineral (FeCO3), besides biological proxies like Fragilaria construens and Stauroforma inermes (planctonic diatoms), and Dicrotendipes sp. and Tanytarsini tribe (littoral chironomids). The pollen ensemble reveals the first glacial refuge of Araucaria araucana forests in the low lands during the LGM. The lake was drained abruptly into a swamp/bog at 12kyr BP and colonized by Myrtaceae wet forest. This evidence suggest the dry/warm climate period of early Holocene in south-central Chile. Later, the sediments indicate variable lacustrine levels, and increase of charcoal particles, associated to current climatic conditions. The pollen spectrum dominated by Myrtaceae and Nothofagus contrasts with a strongly disturb current landscape. Actually, Purén-Lumaco valley constitutes a complex peat-bog system dominated by exotic grasses and forest species (Tritricum aestivum, Pinus radiata and Eucalyptus spp.). Some archaeological antecedents in the area document the human development at ca. 7yrs BP. The greatest archaeological characteristic present in the valley is the kuel, a Mapuche earth accumulation. The presence and extension of almost 300 kuel in the valley reflect the social/economic development, and partly explains why the region was the major resistance area for Spanish colonizer during XVI-XVII centuries. Also the archaeological findings reveal the presence of maize pollen (Zea mays) within their food consumption. The influence of climate and human impact in

Superstition, religion and the political / Superstição, religião e o político

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Michel Despland

2011-01-01

religious realms in modern Western civilization, provides us with “a good context for the confrontation with some of the fundamental problems of justice that remain before us today”. Religion as he sees it, therefore, is finally to be understood as psychologically and historically contingent human action. All the same, it takes place over against the irrational-rational background of some philosophically resilient categories: superstition and morality. Resumo/apresentaçãoCientista da religião reconhecido e respeitado em ambientes intelectuais da América do Norte e da Europa, Michel Despland é ainda pouco conhecido pela academia brasileira. Entre suas publicações estão, por exemplo: Kant on history and religion: with a translation of Kant's On the failure of all attempted philosophical theodicies (McGillQueen's University Press, 1973; The education of desire, Plato and the philosophy of religion (University of Toronto Press, 1985; Les hierarchies sont ebranlees, politiques et theologies au XIXe siècle, (Fides, 1998; Comparatisme et Christianisme: questions d'histoire et de methode (L'Harmattan, 2002. No texto ora publicado, apresentado durante o XII Simpósio da Associação Brasileira de História das Religiões (2011, UFJF, o prof. Despland assume a premissa antropológica de que “a religião é algo que as pessoas fazem.” Baseando-se em Espinosa, Despland elege a categoria da “superstição” como um instrumento de análise mais adequado para a análise do religioso do que, por exemplo, a do “sagrado”. O objetivo mais imediato de Despland é primeiramente entender como o próprio Espinosa constrói os âmbitos político e religioso em sua inter-relação, em continuidade e ruptura com as tradições herdadas da teologia política do Ocidente/do cristianismo. A partir daí, ele passa a sondar historiograficamente as dimensões morais e sociais da religião diante do Estado, tanto em suas próprias instituições, quanto no cada vez mais consp

Basic ecology of the Oaxacan Spiny-tailed Iguana Ctenosaura oaxacana (Squamata: Iguanidae, in Oaxaca, Mexico

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Tamara Rioja

2012-12-01

dry season, which can result in habitat loss and territorial displacement of individualsLa Iguana de Cola Espinosa Ctenosaura oaxacana es una especie restringida al Istmo de Tehuantepec en el Sureste de Oaxaca, México. Este reptil es uno de los iguánidos menos conocidos. Entre Mayo 2010 y Abril 2011 hicimos el seguimiento de una población al Sur de Niltepec, Oaxaca, México. A lo largo de un año, se colocaron y monitorearon un total de diez transectos en el área de estudio, para determinar la abundancia relativa, densidad y uso de hábitat (selva seca, Nanchal, pastizal, vegetación riparia y manglar de la especie. Esta investigación reporta una nueva población de C. oaxacana en el límite sureste de la distribución conocida para la especie. Aunque esta especie posee una distribución muy restringida y se encuentra en peligro de extinción, C. oaxacana presenta una alta densidad poblacional comparada con otras especies de Ctenosaura. Se registró un total de 108 individuos a lo largo del estudio. La selva seca (33.75ind/ha y el Nanchal (18.75ind/ha fueron los hábitats con densidad más alta. No se encontró diferencia significativa entre la selva seca y el Nanchal (W=15, p=0.0808. Al comparar entre estaciones el resultado fue similar. La Iguana de Cola Espinosa prefirió la selva seca y después al Nanchal, mientras que evitó el pastizal, la vegetación riparia y el manglar. No se registró diferencia en el uso de hábitat entre machos y hembras. La altura media de las perchas fue 1.23±0.32 (n=30 en Nanchal, 2.11±0.30 (n=9 en pastizal, 1.90±0.56 (n=54 en selva baja, 1.91±0.28 (n=9 en manglar y 2.30±0.37 (n=6 en vegetación riparia. Las especies observadas como refugio y percha fueron B. crassifolia (Nanchal; C. alata (pastizal; Tabebuia sp., Genipa americana, G. sepium, Acacia sp., Ficus sp. y Haematoxylon sp. (selva seca; G. sepium, Acacia sp. y Guazuma ulmifolia (vegetación riparia; y C. erecta (manglar. La especie utilizó agujeros y ramas de �

[State of food and nutritional care in public hospitals of Ecuador].

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Gallegos Espinosa, Sylvia; Nicolalde Cifuentes, Marcelo; Santana Porbén, Sergio

2014-10-03

The ELAN Ecuadorian Study of Hospital Malnutrition returned a malnutrition rate of 37.1% in public hospitals of Ecuador [Gallegos Espinosa S, Nicolalde Cifuentes M, Santana Porbén S; para el Grupo Ecuatoriano de Estudio de la Desnutrición Hospitalaria. State of malnutrition in hospitals of Ecuador. Nutr Hosp (España) 2014;30:425-35]. Hospital malnutrition could be the result of institutional cultural practices affecting the patient's nutritional status. To present the current state of food and nutritional care provided to patients assisted in public hospitals of Ecuador. The state of food and nutritional care provided to 5,355 patients assisted in 36 hospitals of 23 provinces of the country was documented by means of the Hospital Nutrition Survey (HNS), conducted as part of the ELAN Study. HNS recorded the completion of nutritional assessment exercises, the use of food-bymouth, fasting, use of oral nutritional supplements, and implementation and conduction of Artificial nutritional schemes (Enteral/Parenteral); respectively. Less than 0.1% of clinical charts had a diagnosis of malnutrition included in the list of the patient's health problems. Less than half of the patients had been measured and weighted on admission. Serum Albumin values and Total Lymphocytes Counts were annotated on admission in only 13.5% and 59.2% of the instances, respectively. Current weight value was registered in only 59.4% of the patients with length of stay ³ 15 days. An oral nutritional supplement was prescribed in just 3.5% of non-malnourished patients in which significant metabolic stress and/or reduced food intakes concurred. Although up to 10 different indications for use of Artificial nutrition were identified in the sample study, any of these techniques was administered to just 2.5% (median of observed percentages; range: 1.3 - 11.9%) of surveyed patients. Currently, nutritional status of hospitalized patient is not included within therapeutic goals, nutritional assessment

Perfluoroalkyl Substances, Sex Hormones, and Insulin-like Growth Factor-1 at 6-9 Years of Age: A Cross-Sectional Analysis within the C8 Health Project.

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Lopez-Espinosa, Maria-Jose; Mondal, Debapriya; Armstrong, Ben G; Eskenazi, Brenda; Fletcher, Tony

2016-08-01

Exposure to some perfluoroalkyl substances (PFAS), such as perfluorohexane sulfonate (PFHxS), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA), may alter levels of sex hormones and insulin-like growth factor-1 (IGF-1) in animals. Human studies on this topic are scarce, and none have been conducted in young children. We investigated the relationship between levels of PFAS and estradiol, total testosterone, and IGF-1 in 2,292 children (6-9 years of age) from the C8 Health Project who lived near a chemical plant in the Mid-Ohio Valley (USA) with local contamination from PFOA. Serum samples were collected in 2005-2006 and analyzed for PFAS, sex hormones, and IGF-1. Results from regression models were expressed as the adjusted percentage difference (95% CI) per sex-specific interquartile range (IQR) increment of each PFAS serum concentration. Analyses by PFAS quartiles were also conducted. Median concentrations of PFHxS, PFOA, PFOS, and PFNA were 8, 35, 22, and 1.7 ng/mL in boys and 7, 30, 21, and 1.7 ng/mL in girls. In boys, PFOA concentrations were significantly associated with testosterone levels (-4.9%; 95% CI: -8.7, -0.8%); PFOS with estradiol (-4.0%; 95% CI: -7.7, -0.1%), testosterone (-5.8%; 95% CI: -9.4, -2.0%), and IGF-1 (-5.9%; 95% CI: -8.3, -3.3%); and PFNA with IGF-1 (-3.5%; 95% CI: -6.0, -1.0%). In girls, significant associations were found between PFOS and testosterone (-6.6%; 95% CI: -10.1, -2.8%) and IGF-1 (-5.6%; -8.2, -2.9%); and PFNA and IGF-1 (-3.8%; 95% CI: -6.4, -1.2%). In both sexes, the magnitudes of the associations decreased monotonically across quartiles for both testosterone and IGF-1 in relation to PFOS, and for IGF-1 and PFNA in girls. To our knowledge, this is the first study suggesting that PFAS are associated with lower levels of IGF-1 and sex hormones in young children. Lopez-Espinosa MJ, Mondal D, Armstrong BG, Eskenazi B, Fletcher T. 2016. Perfluoroalkyl substances, sex hormones, and

Investigación sobre manejo forestal a largo plazo en Patagonia Sur -Argentina: Lecciones del pasado, desafíos del presente Long-term forest management research in South Patagonia - Argentina: Lessons from the past, challenges from the present

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GUILLERMO J MARTÍNEZ-PASTUR

2010-03-01

ón de tratamientos intermedios, (iii determinar líneas base y definir los impactos de distintos sistemas silvícolas, (iv proponer metodologías de monitoreo de amplio espectro y establecer áreas demostrativas de manejo, y (v proveer áreas y conocimientos para entrenar profesionales en prácticas de manejo forestal y conservación de la biodiversidad. Las parcelas permanentes ya establecidas en los bosques de Nothofagus de Patagonia Sur y las bases de datos obtenidas podrían servir como punto de partida para definir un núcleo regional que pueda participar en el International Long Term Ecological Research para asegurar el uso sustentable de los bosques nativos.Argentina has based its economy in agriculture and cattle production seeing forests as one of the main obstacles for future development. Forest harvesting in South Patagonia has been an activity based on colonization and exploitation of new areas. Harvesting is mainly carried out in old-growth forests without silviculture management after the first cuts. Beyond this mismanagement, scientific research defined the basis to conserve, protect and improve the present forest management for the South Patagonia native forests. The first long-term study permanent plots (1965-1966 monitored only economic and forest structure parameters, and near twenty plots were established in public forested lands of Tierra del Fuego. Most of these plots were destroyed or discontinued due to a lack of land use planning, scarce social interest for long-term researches, absence of commitment of institutions, and few contributions of forest companies. After this, a second group of nine long-term study permanent plots were established in South Patagonia (1993-2004 based in the collaboration between private companies and national research institutions. The objectives included economic as well as ecological parameters. The new plots were established on private lands based on several agreements and joint venture projects between national

Reconstrucción espacial y temporal de la ocurrencia de avalanchas de nieve en los Andes patagónicos utilizando técnicas dendrocronológicas Dendrochronological reconstruction of spatial and temporal patterns of snow avalanches in the Patagonian Andes

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ALEJANDRO CASTELLER

2009-06-01

Full Text Available Las avalanchas de nieve representan un importante riesgo natural en diversas regiones montañosas alrededor del mundo. Daños a infraestructura y pérdidas de vidas humanas son reportados frecuentemente en relación a eventos catastróficos de avalanchas. En los Andes, numerosas obras de infraestructura se ubican en zonas vecinas a senderos de avalanchas, de las que poco se conoce sobre sus alcances máximos, periodos de retorno y presiones de impacto. A través de la implementación de técnicas dendrocronológicas hemos reconstruido las fechas de ocurrencia y áreas de influencia de eventos pasados de avalanchas de nieve. Ejemplares de Nothofagus pumilio con perturbaciones visibles de avalanchas fueron muestreados en sectores del canal, bordes y zonas de frenado de 11 senderos de avalanchas ubicados en Loma de las Pizarras, próximo a El Chaltén, Santa Cruz, Argentina. Además, áreas de control fueron muestreadas para determinar las condiciones de crecimiento en árboles no afectados por avalanchas. Nuestros análisis indican que las cicatrices, las variaciones de excentricidad en el leño, los cambios abruptos de crecimiento y la presencia de leño de tensión son los principales indicadores dendrocronológicos en N. pumilio asociados a la ocurrencia de avalanchas. Basados en una ponderación cuantitativa de los indicadores y en la profundidad de muestreo, calculamos un índice de ocurrencia de eventos, el cual nos permitió determinar para cada sendero los años con ocurrencia de avalanchas. Considerando de manera integral la actividad de avalanchas en los 11 senderos muestreados, los años con mayor ocurrencia de eventos fueron 1936, 1966, 1978 y 1995. Complementariamente, registros climáticos fueron analizados con el objetivo de determinar las relaciones entre los años con ocurrencia de avalanchas y las variaciones mensuales de precipitación y temperatura. Se observa que los años con gran frecuencia de avalanchas est

The Neogene Environment of the Beardmore Glacier, Transantarctic Mountains

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Ashworth, A. C.; Cantrill, D. J.; Francis, J. E.; Roof, S. R.

2004-12-01

, the absence of solar heating for about 5.5 months, even though there would have been additional heat from open water in the fjord, would have resulted in a low mean annual temperature. Mean summer temperatures, based on the minimal thermal requirements for Nothofagus, listroderine weevils, and freshwater molluscs, are estimated to have been between 4 and 5°C for at least two summer months. The research is supported by NSF grant OPP-0230696

Long-term vegetation, climate and ocean dynamics inferred from a 73,500 years old marine sediment core (GeoB2107-3) off southern Brazil

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Gu, Fang; Zonneveld, Karin A. F.; Chiessi, Cristiano M.; Arz, Helge W.; Pätzold, Jürgen; Behling, Hermann

2017-09-01

Long-term changes in vegetation and climate of southern Brazil, as well as ocean dynamics of the adjacent South Atlantic, were studied by analyses of pollen, spores and organic-walled dinoflagellate cysts (dinocysts) in marine sediment core GeoB2107-3 collected offshore southern Brazil covering the last 73.5 cal kyr BP. The pollen record indicates that grasslands were much more frequent in the landscapes of southern Brazil during the last glacial period if compared to the late Holocene, reflecting relatively colder and/or less humid climatic conditions. Patches of forest occurred in the lowlands and probably also on the exposed continental shelf that was mainly covered by salt marshes. Interestingly, drought-susceptible Araucaria trees were frequent in the highlands (with a similar abundance as during the late Holocene) until 65 cal kyr BP, but were rare during the following glacial period. Atlantic rainforest was present in the northern lowlands of southern Brazil during the recorded last glacial period, but was strongly reduced from 38.5 until 13.0 cal kyr BP. The reduction was probably controlled by colder and/or less humid climatic conditions. Atlantic rainforest expanded to the south since the Lateglacial period, while Araucaria forests advanced in the highlands only during the late Holocene. Dinocysts data indicate that the Brazil Current (BC) with its warm, salty and nutrient-poor waters influenced the study area throughout the investigated period. However, variations in the proportion of dinocyst taxa indicating an eutrophic environment reflect the input of nutrients transported mainly by the Brazilian Coastal Current (BCC) and partly discharged by the Rio Itajaí (the major river closest to the core site). This was strongly related to changes in sea level. A stronger influence of the BCC with nutrient rich waters occurred during Marine Isotope Stage (MIS) 4 and in particular during the late MIS 3 and MIS 2 under low sea level. Evidence of Nothofagus pollen

Efficacy of a self-management plan in exacerbations for patients with advanced COPD

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Sánchez-Nieto JM

2016-08-01

Full Text Available Juan Miguel Sánchez-Nieto,1,2 Rubén Andújar-Espinosa,3 Roberto Bernabeu-Mora,1,2 Chunshao Hu,1 Beatriz Gálvez-Martínez,1 Andrés Carrillo-Alcaraz,1 Carlos Federico Álvarez-Miranda,3 Olga Meca-Birlanga,1 Eva Abad-Corpa4 1Division of Pneumology, Hospital Morales Meseguer, 2University of Murcia, 3Division of Pneumology, Hospital Arrixaca, Murcia, 4Department of Professional Development Unit, Murcia, Spain Background: Self-management interventions improve different outcome variables in various chronic diseases. Their role in COPD has not been clearly established. We assessed the efficacy of an intervention called the self-management program on the need for hospital care due to disease exacerbation in patients with advanced COPD.Methods: Multicenter, randomized study in two hospitals with follow-up of 1 year. All the patients had severe or very severe COPD, and had gone to either an accident and emergency (A&E department or had been admitted to a hospital at least once in the previous year due to exacerbation of COPD. The intervention consisted of a group education session on the main characteristics of the disease, an individual training session on inhalation techniques, at the start and during the 3rd month, and a written action plan containing instructions for physical activity and treatment for stable phases and exacerbations. We determined the combined number of COPD-related hospitalizations and emergency visits per patient per year. Secondary endpoints were number of patients with visits to A&E and the number of patients hospitalized because of exacerbations, use of antibiotics and corticosteroids, length of hospital stay, and all-cause mortality.Results: After 1 year, the rate of COPD exacerbations with visits to A&E or hospitalization had decreased from 1.37 to 0.89 (P=0.04 and the number of exacerbations dropped from 52 to 42 in the group of patients who received the intervention. The numbers of patients hospitalized, at 19 (40

Reseñas de Libros

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Joaquín Piñeiro Blanca

2009-12-01

Full Text Available Álvarez Rey, Leandro (Estudio preliminar, recopilación y edición, Diego Martínez Barrio. Palabra de republicano. Sevilla, Ayuntamiento de Sevilla-Instituto de la Cultura y las Artes, 2007, 1.046 pp.Páginas 177-179Joaquín Piñeiro BlancaBancalari Molina, Alejandro, Orbe romano e Imperio Global. La romanización desde Augusto a Caracalla. Santiago de Chile, Editorial Universitaria, 2007, 330 pp.Páginas 179-182Francisco de Paula Villatoro SánchezBernal-Meza, Raúl y Saha, Suranjit (comps., Economía mundial y desarrollo regional. Buenos Aires, GEL, 2005, 403 pp.Páginas 182-184David Molina RabadánDavis, Mike, Planeta de Ciudades Miseria. Madrid, Foca Editorial, 2007, 283 pp.Páginas 184-185Daniel Alcalde GüelfoElguero Olavide, Ignacio, Los niños de los Chiripitifláuticos: retrato generacional de los nacidos en los 60. Madrid, La Esfera de los Libros, 2006, 672 pp.Páginas 185-189Daniel Francisco Álvarez EspinosaEstulin, Daniel, Los secretos del Club Bilderberg. Editorial Planeta, Barcelona, 2006, 304 pp.Páginas 190-191Mª del Rocío Piñeiro ÁlvarezFernández Bessa, Cristina et al., Frontera Sur. Nuevas políticas de gestión y externalización del control de la inmigración en Europa. Bilbao, Virus Editorial, 2008, 272 pp.Páginas 191-192Manuel Baraja EscuderoGonzález Clavero, Mariano; Pelaz Pérez, José Vidal; Pérez López, Pablo, Castilla y León en democracia. Partido, elecciones y personal político. 1977-2007. Salamanca, Junta de Castilla y León, 2007, 345 pp.Páginas 192-194Francisco de Paula Villatoro SánchezKhanna, Parag, El segundo mundo. Barcelona, Paidós, 2008, 570 pp.Páginas 194-196David Molina RabadánSanmartín Barros, Israel, Entre dos siglos. Globalización y pensamiento único. Madrid, Ediciones Akal, 2007, 334 pp.Páginas 196-198Joaquín Piñeiro BlancaToscano Gil, Francisco, Autonomía y potestad normativa local. Granada, Comares. 2007, 202 pp.Páginas 198-200José Joaquín Fernández AllesVV.AA., Ernesto

Central corneal thickness, intraocular pressure, and degree of myopia in an adult myopic population aged 20 to 40 years in southeast Spain: determination and relationships

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Manuel Garcia-Medina

2011-02-01

Full Text Available Manuel Garcia-Medina1, Jose Javier Garcia-Medina2,3, Pablo Garrido-Fernandez1, Jose Galvan-Espinosa1, Jesus Martin-Molina1, Carlos Garcia-Maturana4, Sergio Perez-Pardo1, Maria Dolores Pinazo-Duran3 1Department of Ophthalmology, Torrecardenas Hospital, Almeria, Spain; 2Department of Ophthalmology, Huercal Overa Hospital, Almeria, Spain; 3Ophthalmology Research Unit “Santiago Grisolia”, University Hospital Doctor Peset, Valencia, Spain; 4University of Sevilla, SpainObjective: To determine the values of, and study the relationships among, central corneal thickness (CCT, intraocular pressure (IOP, and degree of myopia (DM in an adult myopic population aged 20 to 40 years in Almeria (southeast Spain. To our knowledge this is first study of this kind in this region.Methods: An observational, descriptive, cross-sectional study was done in which a sample of 310 myopic patients (620 eyes aged 20 to 40 years was selected by gender- and age-stratified sampling, which was proportionally fixed to the size of the population strata for which a 20% prevalence of myopia, 5% epsilon, and a 95% confidence interval were hypothesized. We studied IOP, CCT, and DM and their relationships by calculating the mean, standard deviation, 95% confidence interval for the mean, median, Fisher’s asymmetry coefficient, range (maximum, minimum, and the Brown-Forsythe’s robust test for each variable (IOP, CCT, and DM.Results: In the adult myopic population of Almeria aged 20 to 40 years (mean of 29.8, the mean overall CCT was 550.12 µm. The corneas of men were thicker than those of women (P = 0.014. CCT was stable as no significant differences were seen in the 20- to 40-year-old subjects’ CCT values. The mean overall IOP was 13.60 mmHg. Men had a higher IOP than women (P = 0.002. Subjects over 30 years (13.83 had a higher IOP than those under 30 (13.38 (P = 0.04. The mean overall DM was -4.18 diopters. Men had less myopia than women (P < 0.001. Myopia was stable in the

Perfluoroalkyl Substances, Sex Hormones, and Insulin-like Growth Factor-1 at 6–9 Years of Age: A Cross-Sectional Analysis within the C8 Health Project

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Lopez-Espinosa, Maria-Jose; Mondal, Debapriya; Armstrong, Ben G.; Eskenazi, Brenda; Fletcher, Tony

2016-01-01

Background: Exposure to some perfluoroalkyl substances (PFAS), such as perfluorohexane sulfonate (PFHxS), perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA), may alter levels of sex hormones and insulin-like growth factor-1 (IGF-1) in animals. Human studies on this topic are scarce, and none have been conducted in young children. Objectives: We investigated the relationship between levels of PFAS and estradiol, total testosterone, and IGF-1 in 2,292 children (6–9 years of age) from the C8 Health Project who lived near a chemical plant in the Mid-Ohio Valley (USA) with local contamination from PFOA. Methods: Serum samples were collected in 2005–2006 and analyzed for PFAS, sex hormones, and IGF-1. Results from regression models were expressed as the adjusted percentage difference (95% CI) per sex-specific interquartile range (IQR) increment of each PFAS serum concentration. Analyses by PFAS quartiles were also conducted. Results: Median concentrations of PFHxS, PFOA, PFOS, and PFNA were 8, 35, 22, and 1.7 ng/mL in boys and 7, 30, 21, and 1.7 ng/mL in girls. In boys, PFOA concentrations were significantly associated with testosterone levels (–4.9%; 95% CI: –8.7, –0.8%); PFOS with estradiol (–4.0%; 95% CI: –7.7, –0.1%), testosterone (–5.8%; 95% CI: –9.4, –2.0%), and IGF-1 (–5.9%; 95% CI: –8.3, –3.3%); and PFNA with IGF-1 (–3.5%; 95% CI: –6.0, –1.0%). In girls, significant associations were found between PFOS and testosterone (–6.6%; 95% CI: –10.1, –2.8%) and IGF-1 (–5.6%; –8.2, –2.9%); and PFNA and IGF-1 (–3.8%; 95% CI: –6.4, –1.2%). In both sexes, the magnitudes of the associations decreased monotonically across quartiles for both testosterone and IGF-1 in relation to PFOS, and for IGF-1 and PFNA in girls. Conclusions: To our knowledge, this is the first study suggesting that PFAS are associated with lower levels of IGF-1 and sex hormones in young children. Citation: Lopez-Espinosa

Transpiration and water use efficiency in native chilean and exotic species, a usefull tool for catchment management?

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Hervé-Fernández, P.; Oyarzun, C. E.

2012-04-01

Land-use and forest cover change play important roles in socio-economic processes and have been linked with water supply and other ecosystem services in various regions of the world. Water yield from watersheds is a major ecosystem service for human activities but has been altered by landscape management superimposed on climatic variability and change. Sustaining ecosystem services important to humans, while providing a dependable water supply for agriculture and urban needs is a major challenge faced by managers of human-dominated or increased antropical effect over watersheds. Since water is mostly consumed by vegetation (i.e: transpiration), which strongly depends on trees physiological characteristics (i.e: foliar area, transpiration capacity) are very important. The quantity of water consumed by plantations is influenced mainly by forest characteristics (species physiology, age and management), catchment water retention capacity and meteorological characteristics. Eventhough in Chile, the forest sector accounts for 3.6% of the gross domestic product (GDP) and 12.5% of total exports (INFOR, 2003), afforestation with fast growing exotic species has ended up being socially and politically questionable because of the supposed impact on the environment and water resources. We present data of trees transpiration and water use efficiency from three headwater catchments: (a) second growth native evergreen forest (Aetoxicon punctatum, Drimys winterii, Gevuina avellana, Laureliopsis philippiana); (b) Eucalyptus globulus plantation, and (c) a mixed native deciduous (Nothofagus obliqua and some evergreen species) forest and Eucalyptus globulus and Acacia melanoxylon plantation located at the Coastal Mountain Range in southern Chile (40°S). Annual transpiration rates ranged from 1.24 ± 0.41 mol•m-2•s-1 (0.022 ± 0.009 L•m-2•s-1) for E. globulus, while the lowest observed was for L. philippiana 0.44 ± 0.31 mol•m-2•s-1 (0.008 ± 0.006 L•m-2•s-1). However

Register of the last 1000 years of environmental, climatic and anthropogenic change in Isla Grande de Chiloé, inferred through a multi-proxy approach: Lake Pastahué, Chile-South Center (42°S)

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Troncoso, Jose; Alvarez, Denisse; Díaz, Gustavo; Fierro, Pablo; Araneda, Alberto; Torrejón, Fernando; Rondanelli, Mauricio; Fagel, Nathalie; Urrutia, Roberto

2017-04-01

Knowledge of the past environmental and climatic conditions of the lake ecosystems of the Isla Grande de Chiloé and its relationship with the anthropic effect, on a high temporal resolution scale, is scarcely known. Specifically, multi-proxy studies provide a better understanding of the context in which changes occurred in the past. This insular region is particularly interesting because environmental conditions (pre and post-Hispanic) and knowledge about the impacts generated in the ecosystems during the Spanish colonization process have so far been little studied, compared to the rest of Chile continental. This research is a new contribution to the scarce information existing for the last millennium of the Isla Grande de Chiloé. The objective of this work was to reconstruct the environmental and climatic history of the last 1000 years, from the Lake Pastahué, in the Isla Grande de Chiloé through a multi-proxy analysis and compare them with other records for the region. The core sediment was sub-sampled to perform sedimentological analysis (organic matter, carbonates, magnetic susceptibility and granulometry) and biological indicators (pollen, chironomids). The age model was constructed from the activity of 210Pb,137Cs and 14C. The pollen results reveal a composition of nordpatagónico forest represented by Nothofagus, Weinmannia, Drimys, Tepualia, Myrtaceae, Poaceae and Pteridophyta, while the anthropic effect for the last cm of the profile is represented by Rumex and Pinus. The results show a significant increase in magnetic susceptibility since the middle of the 20th century, suggesting an increase in allochthonous material to the lake. The sedimentological parameters and the chironomid assembly show similar variations along the profile, which also shows changes in the trophic state of the lake. The changes recorded in lake Pastahue are directly related to past climatic phenomena occurring in the last millennium, such as the medieval climatic anomaly (MCA

Aggregate and soil organic carbon dynamics in South Chilean Andisols

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D. Huygens

2005-01-01

Full Text Available Extreme sensitivity of soil organic carbon (SOC to climate and land use change warrants further research in different terrestrial ecosystems. The aim of this study was to investigate the link between aggregate and SOC dynamics in a chronosequence of three different land uses of a south Chilean Andisol: a second growth Nothofagus obliqua forest (SGFOR, a grassland (GRASS and a Pinus radiata plantation (PINUS. Total carbon content of the 0-10cm soil layer was higher for GRASS (6.7 kg C m-2 than for PINUS (4.3 kg C m-2, while TC content of SGFOR (5.8 kg C m-2 was not significantly different from either one. High extractable oxalate and pyrophosphate Al concentrations (varying from 20.3-24.4 g kg-1, and 3.9-11.1 g kg-1, respectively were found in all sites. In this study, SOC and aggregate dynamics were studied using size and density fractionation experiments of the SOC, δ13C and total carbon analysis of the different SOC fractions, and C mineralization experiments. The results showed that electrostatic sorption between and among amorphous Al components and clay minerals is mainly responsible for the formation of metal-humus-clay complexes and the stabilization of soil aggregates. The process of ligand exchange between SOC and Al would be of minor importance resulting in the absence of aggregate hierarchy in this soil type. Whole soil C mineralization rate constants were highest for SGFOR and PINUS, followed by GRASS (respectively 0.495, 0.266 and 0.196 g CO2-Cm-2d-1 for the top soil layer. In contrast, incubation experiments of isolated macro organic matter fractions gave opposite results, showing that the recalcitrance of the SOC decreased in another order: PINUS>SGFOR>GRASS. We deduced that electrostatic sorption processes and physical protection of SOC in soil aggregates were the main processes determining SOC stabilization. As a result, high aggregate carbon concentrations, varying from 148 till 48 g kg-1, were encountered for all land use

Book Reviews

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Redactie KITLV

2008-12-01

Full Text Available Aisha Khan; Callaloo Nation: Metaphors of Race and Religious Identity among South Asians in Trinidad (Kevin Birth Frances Henry; Reclaiming African Religions in Trinidad: The Socio-Political Legitimation of the Orisha and Spiritual Baptist Faiths (Alfrieta Parks Monagan Margarite Fernámdez Olmos, Lizabeth Paravisini-Gebert; Creole Religions of the Caribbean: An Introduction from Vodou and Santería to Obeah and Espiritismo (Raquel Romberg Johan Wedel; Santería Healing: A Journey into the Afro-Cuban World of Divinities, Spirits, and Sorcery (Raquel Romberg Gerard Aching; Masking and Power: Carnival and Popular Culture in the Caribbean (Stephen Stuempfle James Pritchard; In Search of Empire: The French in the Americas, 1670-1730 (Brett H. Rusforth Gerhard Menzel; Der schwarze Traum vom Glück: Haiti seit 1804 (Michael Zeuske Marcus Rediker; Villains of all Nations: Atlantic Pirates in the Golden Age (Dian Murray Joseph E. Inikori; Africans and the Industrial Revolution in England: A Study in International Trade and Economic Development (Richard Drayton Fernando Picó; Puerto Rico 1898: The War after the War (Mariola Espinosa Luis Martínez-Fernández; Protestantism and Political Conflict in the Nineteenth-Century Hispanic Caribbean (Michael Zeuske Gabino La Rosa Corzo; Runaway Slave Settlements in Cuba: Resistance and Repression (Daniel O. Sayers Bonham C. Richardson; Igniting the Caribbean?s Past: Fire in British West Indian History (Kenneth H. Orvis Bridget Brereton (ed., Theresa Martínez-Vergne, Rnené A. Römer, Blanca G. Silvestrini (co.eds; General History of the Caribbean. Volume V: The Caribbean in the Twentieth Century (Gert Oostindie Perry Mars, Alma H. Young (eds; Caribbean Labor and Politics: Legacies of Cheddi Jagan and Michael Manley (O. Nigel Bolland Euclid A. Rose; Dependency and Socialism in the Modern Caribbean (Obika Gray Bill Schwarz (ed.; West Indian Intellectuals in

Abundancia y distribución de larvas de Strombus gigas (Mesogastropoda: Strombidae durante el período reproductivo de la especie en el Caribe Mexicano Abundance and distribution of Strombus gigas (Mesogastropoda: Strombidae larvae during their reproductive period in the Mexican Caribbean

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José Francisco Chávez Villegas

2012-03-01

Full Text Available El caracol rosa (Strombus gigas, Linnaeus, 1758 es una especie de importancia económica en el Mar Caribe, por lo cual, en la década de 1980 representó la segunda pesquería después de la langosta espinosa, razón por la que actualmente se encuentra en estado de sobrepesca. Con el objetivo de determinar la variación en la abundancia de larvas durante la época reproductiva, cuatro localidades del Caribe Mexicano “CM” (México: Puerto Morelos, Sian Ka’an, Mahahual; Belice: San Pedro fueron muestreadas. Mensualmente, de mayo a octubre del 2008, se realizaron arrastres de plancton en cada localidad empleando una red cónica (300μm. Temperatura (°C, salinidad (ppm y oxígeno disuelto (mg L-1 fueron registrados para cada sitio. Una densidad media larval de 0.34±0.87 larvas•10m-3 fue registrada entre localidades, con un pico de abundancia entre agosto y septiembre (0.82±1.00 y 0.76±1.68 larvas 10m-3, respectivamente. La densidad larval tuvo una correlación del 60% con la salinidad (r=0.6063, p0.05. El 100% de las larvas capturadas corresponden al estadio I definido por Davis et al (1993, mostrando actividad reproductiva local, de esta manera, se considera que los sitios muestreados en el CM son fuente de larvas para la especie S. gigas.Abundance and distribution of Strombus gigas (Mesogastropoda: Strombidae larvae during their reproductive period in the Mexican Caribbean. The Queen Conch (Strombus gigas Linnaeus, 1758 is a species of economic importance in the Caribbean Sea, which, in the 1980’s represented the second fishery after de spiny lobster, reason that is currently in a state of overfishing. In order to determine the larval abundance variation during the reproductive season, four locations of the Mexican Caribbean “MC” (Mexico: Puerto Morelos, Sian Ka’an, Mahahual; Belize: San Pedro were sampled. Monthly, from May to October 2008, planktonic net drags (300μm were carried out at each location. Temperature (�

Colorectal Cancer and Long-Term Exposure to Trihalomethanes in Drinking Water: A Multicenter Case–Control Study in Spain and Italy

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Villanueva, Cristina M.; Gracia-Lavedan, Esther; Bosetti, Cristina; Righi, Elena; Molina, Antonio José; Martín, Vicente; Boldo, Elena; Aragonés, Nuria; Perez-Gomez, Beatriz; Pollan, Marina; Acebo, Ines Gomez; Altzibar, Jone M.; Zabala, Ana Jiménez; Ardanaz, Eva; Peiró, Rosana; Tardón, Adonina; Chirlaque, Maria Dolores; Tavani, Alessandra; Polesel, Jerry; Serraino, Diego; Pisa, Federica; Castaño-Vinyals, Gemma; Espinosa, Ana; Espejo-Herrera, Nadia; Palau, Margarita; Moreno, Victor; La Vecchia, Carlo; Aggazzotti, Gabriella; Nieuwenhuijsen, Mark J; Kogevinas, Manolis

2016-01-01

��control study population. Negative associations with chloroform concentrations and ingestion suggest differences among specific THMs, but these findings should be confirmed in other study populations. Citation: Villanueva CM, Gracia-Lavedan E, Bosetti C, Righi E, Molina AJ, Martín V, Boldo E, Aragonés N, Perez-Gomez B, Pollan M, Gomez Acebo I, Altzibar JM, Jiménez Zabala A, Ardanaz E, Peiró R, Tardón A, Chirlaque MD, Tavani A, Polesel J, Serraino D, Pisa F, Castaño-Vinyals G, Espinosa A, Espejo-Herrera N, Palau M, Moreno V, La Vecchia C, Aggazzotti G, Nieuwenhuijsen MJ, Kogevinas M. 2017. Colorectal cancer and long-term exposure to trihalomethanes in drinking water: a multicenter case–––control study in Spain and Italy. Environ Health Perspect 125:56–65; http://dx.doi.org/10.1289/EHP155 PMID:27383820

Dimorfismo sexual y ciclo reproductivo de la lagartija espinosa arbórea Sceloporus formosus Wiegmann (Squamata: Phrynosomatidae de la zona central del estado de Oaxaca, México Sexual dimorphism and reproductive cycle in the arboreal spiny lizard Sceloporus formosus Wiegmann (Squamata: Phrynosomatidae from central Oaxaca, México

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AURELIO RAMÍREZ-BAUTISTA

2009-12-01

Full Text Available It is well known that geographic variation oceurs in life history characteristics among populations of lizards. Variations in life histories found in some studies are possibly adaptations to environmental pressures. In southwestern México, the reproductive characteristics of the endemic species Sceloporus formosus have been poorly studied throughout its geographic range. We used specimens from scientific collections to describe male and female reproductive eyeles and sexual dimorphism of S. formosus. Other viviparous Sceloporus from high elevations show sexual dimorphism, with males being larger in many morphological characteristics than females. We therefore expected that S. formosus would show sexual dimorphism. However, we found no sexual dimorphism. Males reached sexual maturity at a smaller (47 mm snout-vent length (SVL than females (50 mm. There were no significant differences between sexes and months in liver mass. However, fat body mass in females was greater than in males. For males, there was significant relationship between log10-testis volume and log10-SVL. Testis volume was positively correlated with temperature and was smallest during October, November, and December. For females, there was no significant effect of month on gonad volume. Vitellogenesis oceurred from April to November. Vitellogenic follicles and embryonic development were significantly correlated with precipitation (Pearson correlation, r = 0.80, n = 10, P = 0.0081 and photoperiod (Pearson correlation, r = 0.72, n = 10, P Es bien conocido que la variación geográfica ocurre en las características de historias de vida entre poblaciones de especies de lagartijas. Las variaciones en las características de historias de vida encontradas en algunos estudios son posiblemente adaptaciones a las presiones del ambiente. En el suroeste de México, habita la especie endémica, Sceloporus formosus la cual ha sido poco estudiada en sus características reproductivas a través de su intervalo de distribución geográfica. En este estudio se usaron especímenes provenientes de colecciones científicas para describir el ciclo reproductivo de machos y hembras y dimorfismo sexual de S. formosus. En otras especies vivíparas de altitudes elevadas del género Sceloporus muestran dimorfismo, donde los machos son más grandes que las hembras en muchas características morfológicas; debido a esto, esperábamos que S. formosus mostrara dimorfismo sexual. Sin embargo, no encontramos dimorfismo sexual. Los machos alcanzaron la madurez sexual a menor talla (47 mm en longitud hocico-cloaca (LHC que las hembras (50 mm. En cuanto a la masa del hígado no hubo diferencias significativas entre sexos y meses. Sin embargo, los cuerpos grasos en las hembras fueron mayores que en machos. En los machos, no hubo relaciones significativas entre log10-volumen testicular y el log10-LHC. El volumen testicular se correlacionó positivamente con la temperatura y este fue más pequeño durante octubre, noviembre y diciembre. Para las hembras, no hubo efectos significativos del mes sobre el volumen de la gónada. La vitelogénesis ocurrió de abril a noviembre. Los folículos vitelógenicos y el desarrollo embrionario se correlacionaron significativamente con la precipitación (Correlación de Pearson, r = 0.80,n=10,P = 0.0081 y el fotoperiodo (Correlación de Pearson, r = 0.72, n = 10, P < 0.0001. El tamaño de la carnada basado con el número de embriones, se correlacionó con la LHC (Correlación de Pearson, r = 0.82, n = 10, P = 0.0034. La masa relativa de la carnada no se correlacionó con la LHC de las hembras (Correlación de Pearson, r = 0.43, n = 10, P = 0.2110. Este patrón reproductivo otoñal encontrado es típico de especies vivíparas que habitan altitudes elevadas, donde la temperatura es baja, la precipitación y la humedad son altas. Lo que sugiere que la convergencia en los ciclos reproductivos puede estar asociada con un cambio a las condiciones ambientales imperantes en altitudes elevadas.

Diseño de estrategias para el uso pedagógico de las redes sociales a fin de mejorar el bajo rendimiento académico en la asignatura desarrollo del pensamiento filosófico del primer año de bachillerato en la Unidad Educativa Julio Moreno Espinosa

OpenAIRE

Ramón Orellana, Edison Manuel

2013-01-01

El ser humano en los inicios de la historia se puede decir que se educó o aprendió solo, con el avance social fueron apareciendo filósofos (Sócrates, Platón, Aristóteles) y mentes brillantes que de a poco se fueron convirtiendo en “profesores” para sus comunidades. Los conocimientos se compartían a través de ideas y no necesariamente se necesitaban de cuatro paredes para desarrollar la ciencia del conocimiento y por más primitiva que sea la sociedad el hombre se ha educado. Las bases de la ed...

Salt-Induced Physical Weathering of Stone

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Schiro, M.; Ruiz-Agudo, E.; Rodriguez-Navarro, C.

2010-12-01

form within our porous system was the metastable heptahydrate (NaSO4●7H2O)4, followed by mirabilite (NaSO4●10H2O), and finally thenardite (NaSO4). Combining this sequence with data from TG/DSC, we calculated the supersaturation of the solution with respect to each crystallizing phase as well as the associated crystallization pressure5. In situ environmental scanning electron microscopy (ESEM) complemented 2D-XRD data by giving high magnification images of crystallization and phase transitions during dissolution/precipitation cycles. These results give us a clear understanding of sodium sulfate behavior during evaporative crystallization. Further studies will examine different salts and different substrates. This research will help us to better understand the crystallization of salts and associated weathering in cultural heritage, natural environments and possibly, in other planetary bodies. [1] Rodriguez-Navarro, C. (1998) Geophys. Res. Lett., 25, 3249-3252. [2] Rodriguez-Navarro, C., et al. (2000), Cement Concrete Res., 30, 1527-1534. [3] Espinosa, R., Scherer, G., (2008), Environ. Geol., 56, 605-621. [4] Hamilton, A., Hall, C., (2008), J. Anal. Atom. Spectrom., 23, 840-844. [5] Steiger, M., Asmussen, S., (2008), Geochim. Cosmochim. Acta, 72, 4291-4306.

Reconstructing streamflow variation of the Baker River from tree-rings in Northern Patagonia since 1765

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Lara, Antonio; Bahamondez, Alejandra; González-Reyes, Alvaro; Muñoz, Ariel A.; Cuq, Emilio; Ruiz-Gómez, Carolina

2015-10-01

The understanding of the long-term variation of large rivers streamflow with a high economic and social relevance is necessary in order to improve the planning and management of water resources in different regions of the world. The Baker River has the highest mean discharge of those draining both slopes of the Andes South of 20°S and it is among the six rivers with the highest mean streamflow in the Pacific domain of South America (1100 m3 s-1 at its outlet). It drains an international basin of 29,000 km2 shared by Chile and Argentina and has a high ecologic and economic value including conservation, tourism, recreational fishing, and projected hydropower. This study reconstructs the austral summer - early fall (January-April) streamflow for the Baker River from Nothofagus pumilio tree-rings for the period 1765-2004. Summer streamflow represents 45.2% of the annual discharge. The regression model for the period (1961-2004) explains 54% of the variance of the Baker River streamflow (R2adj = 0.54). The most significant temporal pattern in the record is the sustained decline since the 1980s (τ = -0.633, p = 1.0144 ∗ 10-5 for the 1985-2004 period), which is unprecedented since 1765. The Correlation of the Baker streamflow with the November-April observed Southern Annular Mode (SAM) is significant (1961-2004, r = -0.55, p < 0.001). The Baker record is also correlated with the available SAM tree-ring reconstruction based on other species when both series are filtered with a 25-year spline and detrended (1765-2004, r = -0.41, p < 0.01), emphasizing SAM as the main climatic forcing of the Baker streamflow. Three of the five summers with the highest streamflow in the entire reconstructed record occurred after the 1950s (1977, 1958 and 1959). The causes of this high streamflow events are not yet clear and cannot be associated with the reported recent increase in the frequency of glacial-lake outburst floods (GLOFs). The decreasing trend in the observed and reconstructed

Reseñas de Libros

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Jesús María Ramos Pérez

2009-12-01

Full Text Available Alfaro Monsalve, Karen et al., Historia sociopolítica del Concepción contemporáneo: memoria, identidad y territorio. Santiago-Concepción, Universidad ARCIS-Ediciones Escaparate, 2006 (Taller de Ciencias Sociales “Luis Vitale”.Páginas 195-196Jesús María Ramos PérezCarroll, Tim, La Gran Evasión. La verdadera historia de la fuga más famosa de la Segunda Guerra Mundial. Barcelona, Puzzle Editorial, 2005, 352 pp.Páginas 197-201Daniel Francisco Álvarez EspinosaCerón Torreblanca, Cristian Matías, “La paz de Franco”, la posguerra en Málaga: desde los oscuros años 40 a los grises años 50. Málaga, Servicio de Publicaciones de la Universidad de Málaga, 2007, 408 pp.Páginas 201-203Joaquín Piñeiro BlancaChang, Ha Joon; Grabel, Ilene, Reivindicar el desarrollo. Un manual de política económica alternativa. Barcelona, Intermón Oxfam, 2006, 208 pp.Páginas 203-206Fernando López CastellanoDel Amo, Mercedes; García Rey, Marcos y Ortega, Rafael (eds., El 11-M en la prensa árabe. Sevilla, Mergablum, 2004, 136 pp.Páginas 206-208Diego Iturriaga BarcoHardt, Michael; Negri, Antonio, Imperio. Barcelona, Paidós, 2002, 432 pp.Páginas 208-213Flavia PascarielloJudt, Tony, Postguerra. Una historia de Europa desde 1945. Madrid, Taurus, 2006, 1212 pp.Páginas 213-215David Molina RabadánLópez Castillo, Antonio, El republicanismo de centro. El Partido Republicano Radical de Almería durante la Segunda República (1931-1936. Almería, Instituto de Estudios Almerienses, 2006, 229 pp.Páginas 215-217Mónica Fernández AmadorMarsi, Luca, Estrategias corporativas. Aspectos sociales y consecuencias para la comunidad. Nanterre, Centre de Recherches Ibériques et Ibéro-Américaines, Universidad de Paris X–Nanterre, 2006, 295 pp.Páginas 217-219Alvar De la LlosaMorgan Philip, The Fall of Mussolini. Oxford-New York, Oxford University Press, 2007, 263 pp.Páginas 219-220Jan NelisPisanty Valentina, La difesa della razza. Antologia 1938-1943, con un

Variation in parental investment and relative clutch mass of the spiny-tail iguana, Ctenosaura pectinata (Squamata: Iguanidae in central México Variación en la inversión parental y masa relativa de la nidada en la iguana de cola espinosa Ctenosaura pectinata (Squamata: Iguanidae en el centro de México

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Rubén Castro-Franco

2011-03-01

Full Text Available We measured the length, width, volume, and weight of 871 freshly laid eggs of 28 clutches of Ctenosaura pectinata. The iguanas were obtained from a tropical dry forest area in central Mexico. The relative clutch mass was related positively to the average egg weight but not to average egg volume. Unlike what usually occurs in lizards, where the body length strongly predicts egg production, in C. pectinata clutch size and egg size were not correlated with female weight or snout-vent length. Observed differences revealed variation in the weight-size of the egg within an individual clutch. Therefore, there is not an optimization of the egg in the studied population of Ctenosaura, as usually occurs in small lizards. This variation associated with reproduction takes place in the middle of the dry season, and may be interpreted as an adaptation to facilitate the adjustment of different phenotypes in environments with extreme drought.Medimos la longitud, amplitud, volumen, y peso de 871 huevos recién puestos de 28 nidadas de Ctenosaura pectinata. Las iguanas fueron obtenidas en un área de bosque tropical seco en el centro de México. La masa relativa de la nidada estuvo relacionada positivamente con el peso promedio de los huevos pero no con el volumen promedio del huevo. A diferencia de lo que ocurre usualmente en lagartijas, donde la longitud del cuerpo determina la producción de huevos, en C. pectinata el tamaño de la puesta y el tamaño del huevo no se correlacionan con el peso y tamaño de las hembras. Las diferencias observadas revelan variación en el tamaño y peso de los huevos dentro de las puestas individuales. En consecuencia, no hay una optimización del huevo en la población estudiada de Ctenosaura, como usualmente ocurre en lagartijas de tamaño pequeño. Esta variación asociada con la reproducción tiene lugar a mitad de la estación seca, y puede ser interpretada como una adaptación para facilitar el ajuste de diferentes fenotipos en ambientes con sequía extrema.

Litterfall, litter decomposition and nitrogen mineralization in old-growth evergreen and secondary deciduous Nothofagus forests in south-central Chile Aporte, descomposición de hojarasca y mineralización de nitrógeno en bosques siempreverdes de antiguo crecimiento y bosques secundarios deciduos, centro-sur de Chile

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JEROEN STAELENS

2011-03-01

Full Text Available South Chilean forest ecosystems represent one of the largest areas of old-growth temperate rainforests remaining in the Southern hemisphere and have a high ecological value, but suffer from deforestation, invasion by exotic species, fragmentation, and increasing atmospheric nitrogen (N deposition. To support sustainable forest management, more knowledge is required on nutrient cycling of these ecosystems. Therefore, a descriptive study of nutrient dynamics was done in four Valdivian rainforests in the lower Andes range of south Chile: old-growth and altered evergreen stands and unmanaged and managed secondary deciduous stands. Time series were measured for (i mass (four year and nutrient content (N, K, Ca, and Mg; one year of litterfall, (ii decomposition and nutrient dynamics (N, C, K, Ca, Mg, and P; one year of leaf litter and Saxegothaea conspicua bark litter, and (iii in situ topsoil net N mineralization (one year. Litterfall in the four stands ranged from 3.5 to 5.8 ton ha-1 yr-1, was temporarily lower in the managed than in the unmanaged deciduous stand and had a different seasonality in the evergreen stands than in the deciduous stands. Leaf litter decomposed faster (on average 32 % mass loss after one year than bark litter (8 % but without significant differences between leaf litter types. Net N in evergreen leaf litter decreased during decomposition but increased in deciduous leaf litter. Net soil N mineralization was fastest in the pristine evergreen stand, intermediate in the deciduous stands and slowest in the altered evergreen forest. Given the absence of replicated stands, the definite impact of forest type or management regime on the internal nutrient cycling cannot be demonstrated. Nevertheless, the results suggest that management can affect nutrient turnover by altering species composition and forest structure, while recent (five years selective logging in secondary deciduous forest did not affect litter decomposition or N mineralization rates in the present study.Los ecosistemas forestales del sur de Chile presentan un gran valor ecológico pues constituyen una de las mayores áreas del hemisferio Sur con existencias de bosques templados lluviosos. Están sometidos a procesos de deforestación, invasión de especies exóticas, fragmentación e incremento de depositación de nitrógeno (N atmosférico. Para apoyar su manejo sustentable se requiere de mayor conocimiento en el ciclo de nutrientes de estos ecosistemas. Se estudia la dinámica de nutrientes en cuatro sitios de bosques lluviosos valdivianos de la precordillera de los Andes, centro-sur de Chile: un bosque siempreverde de antiguo crecimiento prístino y otro alterado, un bosque caducifolio secundario con manejo silvícola y otro sin. Durante el período octubre 2002 -septiembre 2006, se estimaron (i masa de la hojarasca (cuatro años y contenido de nutrientes de la hojarasca (un año, (ii descomposición y dinámica de nutrientes de hojarasca (un año y de la corteza de Saxegothaea conspicua, y (iii mineralización neta de nitrógeno (N-min en el suelo in situ (un año. El aporte de hojarasca en los cuatro sitios fluctúa desde 3.5 hasta 5.8 ton ha-1 año-1, y es temporalmente menor en bosque caducifolio manejado, respecto del caducifolio sin manejo. Además, presentan una estacionalidad en los siempreverdes que es diferente, respecto de los deciduos. La hojarasca se descompone más rápidamente (promedio 32 % pérdida de masa después de un año que la corteza (8 %, pero no se presentaron diferencias significativas en la hojarasca. El N neto en la hojarasca de los bosques siempreverdes disminuye durante la descomposición, pero se incrementa en la hojarasca de los deciduos. La N-mineralización neta del suelo fue completa en el bosque siempreverde prístino, intermedia en los bosques deciduos y el más baja en el bosque siempreverde alterado. Dada la ausencia de réplicas en las parcelas, no puede ser demostrado el impacto definido del tipo de bosque o régimen de manejo en el ciclo interno de nutrientes. Sin embargo, los resultados sugieren que el manejo silvícola puede afectar el reciclaje de nutrientes por la alteración en la composición de especies y estructura del bosque, aun cuando en el bosque secundario deciduo una extracción selectiva de madera en tiempo reciente (cinco años, no afecta la descomposición de la hojarasca o los montos de mineralización del nitrógeno.

The influence of production conditions, starting material and deposition environment on charcoal alteration in a tropical biome.

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Ascough, Philippa; Bird, Michael; Meredith, Will; Large, David; Snape, Colin; Manion, Corinne

2014-05-01

Natural and anthropogenic burning events are a key link in the global carbon cycle, substantially influencing atmospheric CO2 levels, and consuming c.8700 teragrams yr-1 of dry biomass [1,2,3]. An important result of this process is charcoal, when lignocellulosic structures in biomass (e.g. wood) are converted to aromatic domains with high chemical stability. Charcoal is therefore not readily re-oxidized to CO2, with estimates of 5-7 ky for the half-life of charcoal carbon in soils [3,4]. Charcoal's high carbon content coupled with high environmental resistance has led to the concept of biochar as a valuable means of global carbon sequestration, capable of carbon offsets comparable to annual anthropogenic fuel emissions [5,6,7]. Charcoal is not, however, an environmentally inert substance, and at least some components of charcoal are susceptible to alteration in depositional environments. Despite the importance of charcoal in global carbon cycling, the mechanisms by which charcoal is altered in the environment remain, as yet, poorly understood. This fact limits our ability to properly incorporate both natural environmental charcoal and biochar into global carbon budgets. This study aimed to improve understanding of charcoal alteration in the environment by examining the influence of production conditions, starting material and deposition environment on the physical and chemical characteristics of charcoal at a field site in the Daintree rainforest. These factors have been identified as critical in determining the dynamics of charcoal in depositional environments [8,9] and climatic conditions at the field site (in Tropical Queensland, Australia) are likely to result in extensive alteration of charcoal. Charcoal from wood (Nothofagus spp.), algae (Enteromorpha spp.), and sugarcane (Saccharum spp.) biomass was produced at temperatures over 300-500°C and exposed to conditions of varying pH and vegetation cover. The effect of these variables on charcoal chemistry

Factors affecting growth of the spiny lobsters Panulirus gracilis and Panulirus inflatus (Decapoda: Palinuridae in Guerrero, México

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Patricia Briones-Fourzán

2003-03-01

Full Text Available The effects of sex, injuries, season and site on the growth of the spiny lobsters Panulirus gracilis, and P. inflatus, were studied through mark-recapture techniques in two sites with different ecological characteristics on the coast of Guerrero, México. Panulirus gracilis occurred in both sites, whereas P. inflatus occurred only in one site. All recaptured individuals were adults. Both species had similar intermolt periods, but P. gracilis had significantly higher growth rates (mm carapace length week -1 than P. inflatus as a result of a larger molt increment. Growth rates of males were higher than those of females in both species owing to larger molt increments and shorter intermolt periods in males. Injuries had no effect on growth rates in either species. Individuals of P. gracilis grew faster in site 1 than in site 2. Therefore, the effect of season on growth of P. gracilis was analyzed separately in each site. In site 2, growth rates of P. gracilis were similar in summer and in winter, whereas insite 1 both species had higher growth rates in winter than in summer. This could be due to spatial differences in processes related to changes in population density and food resources, which were documented in previous works. The overall results show that P. gracilis grows faster than P. inflatus, and that growth rates of both species are highly variable and are affected by environmental factors such as site and season, which should be taken into account when attempting to produce population growth curves for each species.Se analizaron, por medio de marcado-recaptura, los efectos del sexo, heridas, estación del año y localidad sobre el crecimiento de las langostas espinosas Panulirus gracilis Streets, 1871, y Panulirus inflatus (Bouvier, 1895 en dos localidades con diferentes características ecológicas en la costa de Guerrero, México. Panulirus gracilis se presentó en ambas localidades, mientras que P. inflatus sólo se encontró en una de

Composición proximal, ácidos grasos y características fisicoquímicas de aceite de harina artesanal de caribe (Serrasalmus rhombeus Pisces: Characidae proveniente de Caicara del Orinoco-Venezuela

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Granados, Ángel

2006-12-01

Full Text Available Caribe (Serrasalmus rhoembeus is a Characidae fish that lives in the basins of the Orinoco and Amazon rivers. It is an  underutilized specie although in the last years has been marketed in the form of of a meal which is obtained through a handmade process but without information about its chemical composition. This research was conducted to evaluate the proximate composition of commercial caribe meal, the fatty acids profile and some physicochemical properties of its lipidic extract. Three aleatory samples of meal were selected in Caicara del Orinoco shops, Bolívar state –Venezuela. Moisture (6.00 ± 0.45 %, crude protein (N x 6.25: 52.78 ± 2.36 %, crude fat (22.47 ± 1.08 % and total ash (24.58 ± 3.12 % were determined in each sample. The fat was extracted with nhexane and it was analyzed for free fatty acids (5.66 ± 0.15 % as oleic acid, peroxide value (23.50 ± 1.02 meq O2/kg, iodine value (152.2 ± 0.5, saponification value (186.5 ± 0.3 mg KOH/g and unsaponifiable matter (2.3 ± 0.4 g/kg. The fatty acids profile showed an unsaturated acids/ saturated acids ratio of 5.62 with 59.9 % of monounsaturated fatty acids and 25.0 % of polyunsaturated fatty acids. Caribe meal is an important source of nutrients and a potential raw material for human food.El caribe (Serrasalmus rhombeus es un pez de la familia Characidae de la cuenca de los ríos Orinoco y Amazonas, de poco valor comercial debido a su estructura espinosa y a creencias relacionadas con su hábito alimentario, pero que en años recientes los pobladores de las zonas donde existe naturalmente le han dado utilidad mediante la obtención artesanal de una harina que es expendida para consumo humano; sin embargo, no se dispone de información referente a su composición química. El objetivo de esta investigación fue evaluar la composición química proximal del producto comercializado como harina de caribe y algunas características fisicoquímicas del extracto lipídico de la misma

Prioridades de conservación aplicando información filogenética y endemicidad: un ejemplo basado en Carabidae (Coleoptera de América del Sur austral Conservation priorities using phylogenetic information and endemicity: an example based on Carabid beetles from Southern South America

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Sergio Roig-Juñent

2004-12-01

species, 17 areas of endemism were defined. Gamma diversity, percentage of endemism, phylogenetic value, and complementarity, were estimated for each area of endemism, except for the Juan Fernández islands because no information of phylogenetic value was available for this area. Four phylogenetic values of taxonomic weight were calculated, using standardization and endemicity. Results show that standardization of phylogenetic value produce data bias when cladograms differ in size. Complementarity between areas appears as a useful secondary tool. Nevertheless, the results show that complementarity must be used in conjunction with specific diversity and endemicity, to determine the importance of areas. Comparisons of results obtained using W, We, and strict and modified complementarity analyses showed that phylogenetic value with endemicity (We can be applied as a unique value to determine the importance of each area. Using We, the six first areas selected, accumulated 72 % of phylogenetic value, and 74 % of gamma diversity of the southern South American carabids. None of the other used parameters accumulated 70 % of species before the seventh area is added. The six selected areas are the Valdivian rain forest, pampean mountains, Coquimbo, western Patagonia, central Chile, and Araucanian. It is worth to noting that pampean mountains and western Patagonia are grassland habitats, Coquimbo and central Chile are arid and semiarid habitats, and only the Valdivian rain forests and Araucanian are forests with Nothofagus trees

Book reviews

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Redactie KITLV

2011-12-01

Full Text Available Create Dangerously: The Immigrant Artist at Work, by Edwidge Danticat (reviewed by Colin Dayan Gordon K. Lewis on Race, Class and Ideology in the Caribbean, edited by Anthony P. Maingot (reviewed by Bridget Brereton Freedom and Constraint in Caribbean Migration and Diaspora, edited by Elizabeth Thomas-Hope (reviewed by Mary Chamberlain Black Europe and the African Diaspora, edited by Darlene Clark Hine, Trica Danielle Keaton & Stephen Small (reviewed by Gert Oostindie Caribbean Middlebrow: Leisure Culture and the Middle Class, by Belinda E dmondson (reviewed by Karla Slocum Global Change and Caribbean Vulnerability: Environment, Economy and Society at Risk, edited by Duncan McGregor, David Dodman & David Barker (reviewed by Bonham C. Richardson Encountering Revolution: Haiti and the Making of the Early Republic, by Ashli White (reviewed by Matt Clavin Red and Black in Haiti: Radicalism, Conflict, and Political Change, 1934-1957, by Matthew J. Smith (reviewed by Robert Fatton Jr. Cuba in the American Imagination: Metaphor and the Imperial Ethos, by Louis A. Pérez Jr. (reviewed by Camillia Cowling Seeds of Insurrection: Domination and Resistance on Western Cuban Plantations, 1808-1848, by Manuel Barcia (reviewed by Matt D. Childs Epidemic Invasions: Yellow Fever and the Limits of Cuban Independence, 1878-1930, by Mariola Espinosa (reviewed by Cruz Maria Nazario The Cuban Connection: Drug Trafficking, Smuggling, and Gambling in Cuba from the 1920s to the Revolution, by Eduardo Sáenz Rovner (reviewed by Ivelaw Lloyd Griffith Before Fidel: The Cuba I Remember, by Francisco José Moreno, and The Boys from Dolores: Fidel Castro’s Schoolmates from Revolution to Exile, by Patrick Symmes (reviewed by Pedro Pérez Sarduy Lam, by Jacques Leenhardt & Jean-Louis Paudrat (reviewed by Sally Price Healing Dramas: Divination and Magic in Modern Puerto Rico, by Raquel Romberg (reviewed by Grant Jewell

MORPHOMETRY OF THE PEDICLE OF FIRST SACRAL VERTEBRAE AND ITS APPLICATION IN POSTERIOR TRANSPEDICULAR SCREW FIXATION. Morfometría del pedículo de la primera vértebra sacra y su aplicación en la fijación posterior con tornillo transpedicular

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Mangala M Pai

2016-03-01

Full Text Available Los objetivos del presente estudio fueron determinar los parámetros anatómicos del pedículo S1 en la población India del sur para comparar los datos con respecto a los géneros masculinos y femeninos. El estudio incluyó 50 sacros secos (25 hombres y 25 mujeres que se obtuvieron en el laboratorio de anatomía de nuestra institución. En el presente estudio se observa que la longitud media del pedículo S1 fue 49.9± 3,6 mm para los hombres y 46.3± 4,8 mm para las mujeres. La altura céfalo-caudal del pedículo S1 fue 27.2±4.0 mm y 23.9±3.7 mm para el varón y la hembra respectivamente. La anchura antero-posterior del pedículo S1 fue 7.5± 1,3 mm, 7.5± 1.7 mm en varones y mujeres, respectivamente. La distancia antero-posterior de S1, desde el promontorio sacro a la apófisis espinosa de S1 fue 52.9± 5.2 mm y 50.4± 6.8 mm en los géneros masculino y femenino respectivamente. El presente estudio demostró que la longitud y la altura de céfalo-caudal eran más altos (p0.05 en varones que en mujeres. Los datos de mujeres y varones con respecto a la anchura antero-posterior y la distancia antero-posterior de S1 no eran estadísticamente diferentes. El presente estudio ha proporcionado datos morfométricos importantes del pedículo de la primera vértebra sacra de la muestra anatómica de la población India del sur. El conocimiento de los diámetros del pedículo de S1 es crucial para la colocación segura de tornillos para la fijación transpedicular posterior. Objectives of the present study were to determine the anatomical parameters of the S1 pedicle in South Indian population and to compare the data, with respect to male and female genders. The stud­­y included 50 dry sacra (25 male and 25 female, which were obtained from the anatomy laboratory of our institution. It is observed in the present study that the mean S1 pedicle length was 49.9± 3.6 mm for male and 46.3± 4.8 mm for the female. The cephalocaudal heights of S1 pedicle

Reseñas de Libros

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José Miguel Delgado Idarreta

2009-12-01

Editorial, Madrid, 2003, 504 pp.Páginas 222-224Alejandro Román AntequeraPacheco Silva, Arnoldo, Economía y sociedad de Concepción, siglo XIX: Sectores populares urbanos, 1800 – 1885. Concepción, Universidad de Concepción, 2003, 319 pp.Páginas 224-226Mario Valdés UrrutiaPaxton, Robert O., Anatomía del fascismo. Barcelona, Península, 2005, 366 pp.Páginas 226-228Miguel Ángel del Arco BlancoRashke, Richard, Escapar de Sobibor. Barcelona, Planeta, 2004, 592 pp.Páginas 228-230Daniel Francisco Álvarez EspinosaSaid, Edward W., Cultura e Imperialismo. Barcelona, Editorial Anagrama, 2004, 542 pp.Páginas 230-232Joaquín Piñeiro BlancaSkoutelsky, Rémi, Novedad en el frente. Las Brigadas Internacionales en la Guerra Civil. Madrid, Temas de Hoy, 2006, 503 pp.Páginas 232-234Alejandro Piñero González“Pratiques de l'histoire immédiate”. Cahiers d'histoire immédiate, 29 (2006, 501 pp. Número especial: Colección de artículos aparecidos en los Cahiers d'histoire immédiate entre 1991 y 2005, presentada por Jean-François Soulet.Páginas 234-236Iván López CabelloWacquant, Loïc (Dir. Repensar los Estados Unidos. Para una sociología del hiperpoder. Barcelona, Anthropos Editorial, 2005, 239 pp.Páginas 236-238Marcela Iglesias Onofrio

Descriptive study of 20 patients with schizophrenia in Boyacá, Colombia Schizophrenia = Estudio descriptivo de una muestra de pacientes con esquizofrenia residentes en el departamento de Boyacá, Colombia Zayda Lorena Corredor Rozo1 , Mayely Paola Sánchez Espinosa1 , Milena Rondón Lagos2 , Paola Liliana Páez Rojas3 , Carolina Cortés Duque4 , Ruth Maribel Forero Castro5 RESUMEN

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Zayda Lorena Corredor Rozo

2013-07-01

Full Text Available Schizophrenia is a multifactorial disease with high genetic heterogeneity and complex inheritance. In Boyacá, Colombia, we studied a group of 20 schizo- phrenic patients (16 men and four women in order to establish their socio-demographic and clinical characteristics, and the genetic and predisposing factors. Cytogenetic studies and a descriptive anal- ysis of qualitative and quantitative variables were done. More often the disease started in young adults (average age of initiation: 22.5 years. The predomi- nant subtype (8/20 was paranoid schizophrenia, with progressive start (14/20. Predisposing factors were found in 15 patients, namely: physical in nine, social in five and economic in one. All cariotypes were normal. Clinical features did not associate with either the sociodemographic characteristics or the genetic and predisposing factors; this is evidence of the clinical heterogeneity of schizophrenia. Patients and their families received genetic counseling and explanations on the results, the possibility of recur- rences and the risk of suffering the disease when a relative is affected by it. Further and larger studies are required in order to determine if the factors eval- uated in this work have influence on the develop- ment of the disease.

Decadal variability in growth of the Caribbean spiny lobster Panulirus argus (Decapoda: Paniluridae in Cuban waters

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Maria Estela de León

2005-09-01

Full Text Available Annual von Bertalanffy growth parameters of the Caribbean spiny lobster (Panulirus argus in Cuban waters were estimated from a long term study (40 years by length-based methods ELEFAN and the new version of SLCA. Data of around 800 000 lobsters (with carapace length ranging 14 to 199mm were randomly sampled in artificial shelters (a non selective fishing gear very common in the lobster fishery, through the field monitory program established for this species since 1963 in 14 localities of southwestern Cuban shelf. The software ELEFAN showed problems to converge in an optimal combination of the instantaneous growth coefficient (K and the asymptotic length (L8 of the von Bertalanffy equation, whereas the new SLCA software produced value estimates of K between 0.20 and 0.27 year-1 and values of L8 between 177 and 190 mm carapace length, all within the range reported in the literature. The standardized anomalies of both parameters showed the presence of cycles along the analyzed time series. Decadal variability in growth parameters was revealed through the spectral analysis indicating cycles of 16 and 20 years for K and of 16 years for L8. The incidence of some factors such as biomass and temperature that modulate growth in this crustacean was explored, using a nonlinear multiple regression model. These combined factors explained 33% and 69% of the variability of K and L8 respectively. The growth coefficient appeared to be maximum with annual mean sea surface temperature of 28.1º C and the largest L 8is reached at a annual men biomass level of 23 000 t. These results should be the basis to understand the Cuban lobster population dynamics. Rev. Biol. Trop. 53(3-4: 475-486. Epub 2005 Oct 3.Los parámetros de crecimiento anuales para la langosta espinosa del Caribe (Panulirus argus en aguas cubanas se estimaron para una serie de 40 años de datos de composición por longitud, a través de los métodos indirectos basados en la talla ELEFAN y el nuevo

Two-phase flow heat transfer in nuclear reactor systems

International Nuclear Information System (INIS)

Koncar, Bostjan; Krepper, Eckhard; Bestion, Dominique; Song, Chul-Hwa; Hassan, Yassin A.

2013-01-01

Complete text of publication follows: Heat transfer and phase change phenomena in two-phase flows are often encountered in nuclear reactor systems and are therefore of paramount importance for their optimal design and safe operation.The complex phenomena observed especially during transient operation of nuclear reactor systems necessitate extensive theoretical and experimental investigations. This special issue brings seven research articles of high quality. Though small in number, they cover a wide range of topics, presenting high complexity and diversity of heat transfer phenomena in two-phase flow. In the last decades a vast amount of research has been devoted to theoretical work and computational simulations, yet the experimental work remains indispensable for understanding of two-phase flow phenomena and for model validation purposes. This is reflected also in this issue, where only one article is purely experimental, while three of them deal with theoretical modelling and the remaining three with numerical simulations. The experimental investigation of the critical heat flux (CHF) phenomena by means of photographic study is presented in the paper of J. Park et al. They have used a high-speed camera system to observe the transient boiling characteristics on a thin horizontal cylinder submerged in a pool of water or highly wetting liquid. Experiments show that the initial boiling process is strongly affected by the properties and wettability of the liquid. The authors have stressed the importance of the local scale observation leading to better understanding of the transient CHF phenomena. In the article of G. Espinosa-Paredes et al. a theoretical work concerning the derivation of transport equations for two-phase flow is presented. The author proposes a novel approach based on derivation of nonlocal volume averaged equations which contain new terms related to nonlocal transport effects. These non-local terms act as coupling elements between the phenomena

Noticias de la Academia 1990

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Victoria Rodriguez

1991-03-01

Gonzalo Franco y Eduardo Estrada. “Adhesión al Tratamiento Médico” fué la ponencia de la Académica Eugenia Guzmán Cervantes. El académico Gonzalo López Escobar disertó sobre “Enfermedad Diverticular del Colon”. El Académico Hernández Sáenz presentó “La Pediatría en 1989-1990. El Foro sobre “Otitis Media en el Niño” fué promovido por el Académico Jorge García Gómez, la intervención del Académico Alberto Hernández Sáenz y asistió por invitación, el doctor Juan Manuel García Gómez.

Las Nuevas Tecnologías en Investigación Ortopédica en Países Desarrollados y en Vía de Desarrollo, fueron analizadas por el Académico Valentín Malagón. “La Enfermedad de Legg-Calvé-Perthes” fue presentada por el Académico Valentín Malagón Castro y los doctores Ernesto Pieschacón y Juan Manuel Malagón Santos, ambos por invitación. “Etica en Cirugía” y “Reflexiones Eticas alrededor de la Operación Cesárea”, fueron los temas tratados por los Académicos Joaquín Silva Silva y Fernando Sánchez Torres. El Académico Bernardo Tirado Plata, con la colaboración de los Académicos Hernando Forero Caballero y Tito Tulio Roa y por invitación el doctor Orlando Pérez trataron el tema sobre “Angiodisplasias”.

Visitantes: el doctor Jesús Martín Ramírez, de la Universidad de Sevilla, trató el tema de la “Investigación Psicobiológica de la Agresión”. El doctor Thomas J. Pentelényi, Jefe de Neurología del Instituto Nacional de Traumatología de Budapest.

Viaje a Barranquilla: la Junta Directiva de la Academia visitó al Capítulo de Barranquilla. En sesión solemne del 28 de septiembre, condecoró a los académicos José Manuel Baena Lavalle y Aquilea Hernández Barreto. Se recibió como nuevo académico Correspondiente al doctor Humberto Espinosa Taboada...

PREFACE: International Symposium on Ultrasound in the Control of Industrial Processes (UCIP 2012)

Science.gov (United States)

Segura, Luis Elvira; Resa López, Pablo; Salazar, Jordi; Benedito Fort, José Javier; Martínez Graullera, Óscar

2012-12-01

Multiple Scattering of Generic Waves in Particulate Composites' by Félix Alba Consulting. A total of 93 delegates from 21 countries participated actively in this event, and more than ten companies were involved through oral communications, tutorials, exhibition or sponsorship. Conference photograph Conference photograph Organizers Organizers SCIENTIFIC COMMITTEE Dr Luis Elvira, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Dr Pablo Resa, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Dr Oscar F Martinez-Graullera Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Dr Jordi Salazar Department of Electronic Engineering Universitat Politècnica de Catalunya, Spain Dr Jose Benedito Universitat Politècnica de València, Spain ORGANIZING COMMITTEE Dr Luis Elvira, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Prof Malcolm J W Povey, Procter Department of Food Science University of Leeds, United Kingdom Dr Jordi Salazar, Department of Electronic Engineering Universitat Politècnica de Catalunya, Spain Dr Jose Benedito, Universitat Politècnica de València, Spain Dr Oscar F Martinez-Graullera, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Carmen Duran, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Dr Pablo Resa, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Dra Cristina Aparicio, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Prof Francisco Montero de Espinosa, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Jaime Rodríguez-López, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Dr Carlos Sierra, Centro de Acústica Aplicada y Evaluación No Destructiva (CAEND), UPM-CSIC, Spain Shiva Kant Shukla, Centro de Acústica Aplicada y

Florística y fisonomía de un matorral xerófilo espinoso intervenido en Punta de Piedras, Municipio Miranda, Estado Zulia, Venezuela

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Antonio Vera

2009-06-01

gossypifolia, especies que presentaron las mayores abundancias relativas de 32.82, 15.60 y 15.14%, respectivamente. El matorral xerófilo espinoso de Punta de Piedras presentó un bajo número de especies en comparación con otras comunidades xerófilas, no intervenidas, del país. Sin embargo, a pesar de la intervención antropogénica presente en esta comunidad, los manchones de vegetación mostraron rasgos fisonómicos análogos a los correspondientes a otras formaciones xerófilas espinosas no perturbadas de Venezuela.Floristic and physiognomic characteristics of disturbed thorny xerophytic scrubland in Punta de Piedras, Miranda Municipality, Zulia State, Venezuela. We determined the floristic and physiognomic aspects of disturbed thorny xerophytic scrubland in Punta de Piedras, Miranda Municipality, Zulia State, Venezuela. Botanical sampling was done twice monthly (November 2005-June 2006, in both rainy and dry seasons, for a total of 16 samples. The sampling was done in 10 vegetation patches, in an average area of 718,2 ± 706,24 m², and adjacent graminoid floristic components were identified using three 400 m² (20 x 20 m plots, divided into 4 subplots (20 x 5 m² and in these, were delimited 12 subplots (1 x 1 m². In addition, human paths were carried out in order to identify other species plant. Thorny xerophytic scrubland showed human disturbances e.g. periodic fires, solid wastes, roads and human settlements and coastal semiarid thorny scrubland characteristics, similar to another Venezuelan localities. Forty-five species, in 22 families were identified, and the Poaceae (6, Mimosaceae (4, Boraginaceae (3, Cactaceae (3, Caesalpinaceae (3, Euphorbiaceae (3 and Fabaceae (3 presented the highest number of species. Human disturbances probably favor the appearance of vegetation patches and secondary grassland formations. In the last, Aristida venesuelae, Aristida pittieri y Portulaca pilosa showed the highest relative abundances and frequencies values with a summatory

¿Reforma del Estado o cambio en la matriz socio-política? El caso chileno

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Manuel Antonio GARRETÓN

2009-11-01

still persist some institutional and socioeconomic enclaves. Although this reform has not been outlined from a global perspective, it has been developed in some particular dimensions. Finally, Garretón and Espinosa pose the different aspects of a State Reform in a close future, underlying an autonomous and complementary strength of the three components of the sociopolitical matrix and studying the consequences for the State itself, in the sense of a recomposition of its apparatus and surpassing the agregation model for one of a complete transformation

Editorial. La naturaleza y comprensión del territorio a través del hecho y memoria social

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Jorge Inzulza Contardo

2015-12-01

, clama por una aún esperada sustentabilidad del crecimiento económico y el desarrollo social de la región. El autor agrega que es fundamental y urgente lograr una mejor distribución territorial del cobre, como el ”sueldo de Chile”, para con ello “reducir la brecha entre sus máximos ingresos per capita y su mayor pobreza multidimensional en sus áreas de vivienda, salud y educación; y tender hacia un crecimiento más sustentable”. Posteriormente, se explora la importancia del diseño urbano, a través de una trilogía de trabajos que se sitúan el hábitat residencial y diversos senderos y recorridos, tanto en el ambiente urbano como natural. Dentro de este grupo, Lorena Urbano y Monserrat Delpino nos invitan a explorar el paisaje penquista desde la convivencia y seguridad en espacios comunitarios del movimiento moderno. Usando como escenario la trascendida Remodelación Paicaví en Concepción, las autoras ponen en discusión la dialéctica que ofrece aplicar patrones urbanos como la supermanzana y sus implicancias en el espacio púbico y tejido urbano mayor, advirtiendo dificultades para la interacción de los habitantes y comprensión del barrio. De esta forma, las autoras abogan por las necesidad de metodologías imbricadas de análisis que permitan diagnosticar elementos del entorno tanto inmediatos como mediatos. Por su parte, Paulina Espinosa, Bruno de Meulder, Mabel Alarcón y Leonel Pérez nos presentan una investigación sobre el urbanismo del paisaje, sumergiéndose en el caso del Río Andalién, Concepción. Desde la relación dialéctica agua-ciudad, los autores construyen un atlas exploratorio que permite adentrarse en “la valoración y evaluación de los elementos del paisaje, en busca de conflictos y potencialidades en relación a la urbanización”. Es así que el análisis ha permitido detectar alteraciones en los ciclos del agua y en el territorio que ponen en cuestionamiento temas fundacionales como es el emplazamiento de la ciudad y

Selected Abstracts of the 2nd Congress of joint European Neonatal Societies (jENS 2017; Venice (Italy; October 31-November 4, 2017; Session "Neonatal Fetal Nutrition and Metabolism"

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--- Various Authors

2017-10-01

SUFFERING FROM WILSON’S DISEASE • T. Reicherzer, G. Schütze, M. Vogeser, A. Schulze, A.W. FlemmerABS 28. EARLY ENERGY AND PROTEIN INTAKE AFFECTS GROWTH AND MORBIDITY IN EXTREMELY PRETERM INFANTS • S. Klevebro, V. Westin, E. Stoltz Sjöström, M. Norman, M. Domellöf, A.-K Edstedt Bonamy, B. HallbergABS 29. USE OF PROBIOTICS IN PRETERM NEWBORNS. DOES FEEDING TOLERANCE IMPROVE? • M.I. Huescar, M.G. Espinosa, T. Sanchez, E. SalgueroABS 30. VALID AND RELIABLE EARLY IDENTIFICATION OF NEONATAL DYSPHAGIA • M. Viviers, A. KritzingerABS 31. EFFECT OF INFANT FORMULA WITH PROTEIN CONTENT OF 1.6 G/100 KCAL FED BETWEEN 3-12 MONTHS ON BODY COMPOSITION AND ADIPOSITY AT AGE 5 YEARS • E.E. Ziegler, D.A. Fields, S.D. Chernausek, D. Grathwohl, J.M. Jeter, S.E. Nelson, M. Chen, N.P. Hays, F. HaschkeABS 32. EARLY-LIFE PROTEIN INTAKE IN INFANTS BORN EXTREMELY PRETERM IS ASSOCIATED WITH HIGHER BLOOD PRESSURE AT SCHOOL-AGE • I. Zamir, E. Stoltz Sjöström, A.K. Edstedt Bonamy, L.A. Mohlkert, M. Norman, M. DomellöfABS 33. EXTRAUTERINE GROWTH RESTRICTION ASSOCIATED FACTORS IN SMALL AND APPROPRIATE FOR GESTATIONAL AGE INFANTS: A COHORT STUDY • C. Morcelli-Tovar, A.A. VieiraABS 34. IS THERE ANY ASSOCIATION BETWEEN LAMELLAR BODY COUNTS AND CORD BLOOD VITAMIN D LEVELS OF TERM AND LATE PRETERM INFANTS? • N. Okur, H.G. Kanmaz, M. Buyuktiryaki, H. Bezirganoglu, G.K. Simsek, F.E. Canpolat, N. Uras, S.S. OguzABS 35. NEONATAL BODY COMPOSITION OF INFANTS BORN TO MOTHERS WITH GESTATIONAL DIABETES MELLITUS • A.M. Pavel, M. O’Riordan, L. Culliney, T. Nabialek, J. De Meulemeester, F. Caulfield, A. Stanescu, Z. Coffrey, D. Coffey, A. DoolanABS 36. EFFECT OF ENTERAL IRON SUPPLEMENTA­TION ON HEALTH OUTCOMES IN PRETERM AND LOW BIRTH WEIGHT INFANTS: A SYS­TEMATIC REVIEW • E. McCarthy, M. KielyABS 37. NEONATAL INTESTINAL FAILURE IN THE UK – WHO CARES? • R. Jones, P. CairnsABS 38. PREVALENCE OF PREDIABETES AND TYPE 2 DIABETES IN YOUNG ADULTS BORN WITH VERY LOW BIRTH WEIGHT • M. Talman

Selected Abstracts of the 2nd Congress of joint European Neonatal Societies (jENS 2017; Venice (Italy; October 31-November 4, 2017; Session "Neonatal Pulmonology, Neonatal Respiratory Support, Resuscitation"

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--- Various Authors

2017-10-01

VOLUME GUAR­ANTEE USING VERY LOW TIDAL VOLUMES TO PREVENT LUNG DAMAGE IN IMMATURE NEWBORNS • N. González-Pacheco, A. Rodríguez-Sánchez de la Blanca, C. Ramos-Navarro, M. Velilla-Aparicio, I. Marsinyach-Ros, I. Pescador-Chamorro, M. Sánchez-LunaABS 106. MANAGEMENT OF PNEUMOTHORAX IN NEW­BORNS: A NEONATAL INTENSIVE CARE UNIT EXPERIENCE IN TUNISIA • K. Ben Ameur, T. Khemis, A. Ben Salem, H. Ben Hamida, F.Z. Chioukh, K. MonastiriABS 107. THE SAFE PROTOCOL: A SONOGRAPHIC AL­GORITHM FOR LIFE-THREATENING EMER­GENCIES IN THE NEONATAL INTENSIVE CARE UNIT • N. Yousef, S. Shankar-Aguilera, D. De LucaABS 108. MACROLIDE THERAPY AND INCREASED PA­TENT DUCTUS ARTERIOSUS TREATMENT IN UREAPLASMA-POSITIVE PREMATURE IN­FANTS • S. Kim, E. Jung, H. Kim, W.S. Song, J.H. Hwang, C.Y. Kim, B.S. Lee, E.A.-R. Kim, K.-S. KimABS 109. MALIGNANT PERTUSSIS. IS IT TIME FOR EXCHANGE TRANSFUSION? • R. Roldán, M. Huescar, M.G. Espinosa, A. Morales, E. SalgueroABS 110. DELAYED CORD CLAMPING DURING RE­SUSCITATION – A RANDOMIZED TRIAL • O. Andersson, A. KC, N. Rana, U. Ewald, M. MålqvistABS 111. PERI-OPERATIVE MANAGEMENT OF NEO­NATES WITH ESOPHAGEAL ATRESIA IN LOW-INCOME COUNTRIES: EXPERIENCE OF TUNISIA • F.Z. Chioukh, K. Ben Ameur, T. Khemis, A. Ksia, A. Ben Salem, H. Ben Hamida, K. MonastiriABS 112. LESS INVASIVE SURFACTANT AD­MIN­IS­TRATION IN PRETERM INFANTS. REVIEW AFTER 4 YEARS OF IMPLEMENTATION • C. Ramos-Navarro, S. Zeballos-Sarrato, N. Gonzalez-Pacheco, A. Rodriguez-De la Blanca, M. Arriaga-Redondo, S. Villar-Castro, I. Pescador-Chamorro, N. Navarro-PatiñoABS 113. COMPARISON OF RSV HOSPITALISATION IN PRETERM INFANTS WITH CHRONIC LUNG DISEASE WHO DO NOT QUALIFY FOR PALIVIZUMAB PROPHYLAXIS WITH THOSE WHO QUALIFY IN NOTTINGHAM, UK • S. Tsilika, D. BatraABS 114. AN UNUSUAL CAUSE OF RESPIRATORY DISTRESS IN NEONATES: CONGENITAL PULMONARY LYMPHANGIECTASIA (TWO CASE REPORTS • S. Nouri Merchaoui, N. Mahdhaoui, H. Ayache, M. Bellalah, I. Kacem, H. Barbouche, A. Ghith, M