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Se presenta un catálogo de las plantas vasculares que crecen en Chile. Está organizado por divisiones, Pteridophyta (Lycopodiopsida y Polypodiopsida), Pinophyta (Gnetopsida y Pinopsida) y Magnoliophyta (Liliopsida y Magnoliopsida), y dentro de cada grupo, las jerarquías taxonómicas (Familia, Género, Especies y taxones infraespecíficos) están ordenados alfabéticamente. Se incluye además un índice alfabético de géneros con indicación de la familia y grupo a que pertenecen. De acuerdo a este catálogo la flora de las plantas vasculares que crecen en Chile, comprende 186 familias, 1121 géneros y 5471 especies, de éstas, 4655 corresponden a especies nativas, de las cuales 2145 son endémicas de Chile y 816 las especies introducidas.

Variability in anatomical stem traits could be related with the environmental conditions where plants develop (e.g. low temperatures, drought, short growing season), and this variability reflects the ability of a species to be established in habitats that differ in these conditions. Maihuenia poeppigii (Otto ex Pfeiff.) K. Schum is not only one of the Cactaceae species with the southernmost distribution of America, but also presents populations along a wide range of altitudes (approx. from 15 to 2,600 masl.), where the climate varies greatly. This study evaluates the variability in stem anatomical traits related to xylem conduction (density, diameter and relative hydraulic conductivity of vessels) and to water storage (degree of succulence of stem and leaves), in three populations of M. poeppigii that are established in an altitudinal gradient in the South-Central Chile. Additionally, the maximum height of the M. poeppigii cushions was determined as a measure of its exposure to the environment. Average density, diameter and relative hydraulic conductivity of vessels differed significantly among populations from different altitudes. While vessel density and succulence of the stems increased in populations located at higher altitudes in the gradient, diameter of the vessels and plant height decreased. The succulence of the leaves did not differ among the three surveyed populations. The variation found in these anatomical traits reflects a differential strategy in the use and storage of water between the populations established in the altitudinal gradient. This pattern of functional responses can explain the ability of this species to occupy sites that differ in altitude.

The 96 Mount Everest Disaster refers to the events that took place from May 10 to 11, 1996, when eight people caught in a storm were died, some during the ascent and, those who had already reached the Summit, while they descended. The film Everest (2015) faithfully reflects the previous symptoms that occurred during ascension, an important reason to understand the effects of altitude and low gas pressures on the human body. In this paper we address both problems, Everest can help students to understand and reflect on the challenges for body homeostasis that take place at great heights.

Resumen Esta investigación evalúa los efectos de las mezclas de biodiésel de aceite de fritura usado (B10 y B20) con combustible convencional, en términos de emisiones, a gran altitud (entre 2619 y 2877 m s. n. m.), bajo condiciones reales de conducción en el Distrito Metropolitano de Quito, Ecuador. Se realizaron ensayos comparativos con dos vehículos con motor diésel; el primer sistema CRDI de inyección directa de common rail denominado M2.5C; el segundo, con sistema de bomba de inyección, denominado H2.5B, ambos alimentados inicialmente con diésel puro como línea base. Las tasas de emisiones de escape se cuantificaron en caliente mediante el sistema portátil de medición de emisiones (PEMS), a lo largo de una ruta de 15,7 km que incluyó condiciones de ascenso, descenso por carretera y tramos urbanos. Los resultados permiten concluir que las emisiones mínimas de CO se registran al utilizar diésel convencional en ambos motores (H2.5B y M2.5C); las emisiones de HC son mínimas con la mezcla B20, y las emisiones de NOx no presentan variaciones significativas, independientemente del combustible utilizado. En el circuito urbano, tampoco se observa una variación significativa de las emisiones de NOx según el tipo de combustible.

Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is one of the principal quarantine pests in Colombian fruit production. Studies have shown that the nominal species is a complex of cryptic species and that the more common biological entity that exists in Colombia, the “Andean morphotype,” is a species, different from others on the continent. The bioecological information available for this morphotype is scarce, yet it is essential for establishing integrated pest management programs and for defining the insect's quarantine status. Knowledge of the pest's population structure, whether biological, genetic or morphological, is a valuable tool in making management decisions. The goal of this study was to gain information on the phenotypic structure of the Colombian populations of this species complex through the morphometric study of the eggs, larvae, and adults. Populations of A. fraterculus s.l. from 2 fruit species widely known as hosts for this insect (coffee, Coffea arabica L. [Rubiaceae], at medium altitudes; feijoa, Acca sellowiana (O. Berg) [Myrtaceae]) at high altitudes) were collected at 9 Colombian localities from the south of the country (Nariño) to the northeast (Santander). Adults were obtained from the collected fruits, which were then used to rear insects in feijoa fruits. Significant variables were selected using a discriminant analysis, and the differences between the populations were analyzed using a multivariate analysis of variance. The variability of each significant variable was studied with a Kruskal-Wallis nonparametric analysis. The morphological variables studied were 21 for adult females, 7 for adult males, 24 for third-instar larvae, and 2 for the eggs. Intraspecific variability was found in the Colombian populations of the A. fraterculus Andean morphotype. In populations from higher altitudes, the adults and larvae are larger, whereas the eggs are smaller, compared to populations from lower altitudes. Variability might have a genetic component and be due to the limited movement of the individuals, which may favor the application of management activities in selected areas.

La pràctica del muntanyisme gaudeix en l’actualitat d’una gran popularitat entre els nostres esportistes. Els muntanyencs que es mouen en grans altituds es veuen exposats freqüentment a climatologies molt adverses i vies de gran dificultat física i tècnica, però possiblement l’enemic més temible al que s’han d’enfrontar té a veure amb els indesitjables efectes de la hipòxia. La present recerca se centra a constatar possibles deterioracions en les habilitats del pensament d’un grup de muntanyencs exposat a altituds extremes (per sobre dels 5.500 metres), sense l’ajuda d’oxigen suplementari. Per a això hem comptat amb la participació de muntanyencs de tres expedicions als “vuitmils” Manaslu, Makalu i Gasherbrum II als quals es van aplicar proves d’aptituds mentals abans, durant i després de cada expedició. La singularitat d’aquest estudi resideix a haver-hi incorporat resultats de proves realitzades en altituds extremes, en concret a 5.800, 6.200 i 6.000 metres respectivament. Els resultats posen de manifest que de totes les àrees i funcions cognitives avaluades, sembla que les més afectades pels efectes de la hipòxia han estat les relacionades amb la capacitat de raonament abstracte, espacial i verbal. Les deterioracions més evidents es van observar en altitud, persistint aquestes al cap d’una setmana de tornar. Després de sis mesos aquests dèficits es van recuperar per complet.

Comparison of 14C (carbon-14) in archived (pre-1963) and contemporary soils taken along an elevation gradient in the Sierra Nevada, California, demonstrates rapid (7 to 65 years) turnover for 50 to 90 percent of carbon in the upper 20 centimeters of soil (A horizon soil carbon). Carbon turnover times increased with elevation (decreasing temperature) along the Sierra transect. This trend was consistent with results from other locations, which indicates that temperature is a dominant control of soil carbon dynamics. When extrapolated to large regions, the observed relation between carbon turnover and temperature suggests that soils should act as significant sources or sinks of atmospheric carbon dioxide in response to global temperature changes

We explored the fine-scale distribution of cytotypes of the mountain plant Senecio carniolicus along an altitudinal transect in the Eastern Alps. Cytotypes showed a statistically significant altitudinal segregation with diploids exclusively found in the upper part of the transect, whereas diploids and hexaploids co-occurred in the lower range. Analysis of accompanying plant assemblages revealed significant differences between cytotypes along the entire transect but not within the lower part only, where both cytotypes co-occur. This suggests the presence of ecological differentiation between cytotypes with the diploid possessing the broader ecological niche. No tetraploids were detected, indicating the presence of strong crossing barriers.

Since 1998, the Ain-Karim Vineyard has been growing different grape varieties for the production of high-altitude tropical wines in the municipality of Sutamarchan, located in the Alto Ricaurte region of Boyaca (Colombia). Pruning is used to limit the number and length of branches, generating a suitable balance between plant vigor and production; thereby, regulating fruit quantity and quality and ensuring reserves for the subsequent production. This study aimed to evaluate the effect of three pruning types (short = two buds on two spurs; long = five buds on three spurs and mixed = combination of short and long pruning types) on the fruit quality of V. vinifera, Cabernet Sauvignon and Sauvignon Blanc varieties. To accomplish this, a completely randomized two-factor design was used. Physicochemical variables of fruit quality (fresh cluster weight, water content, total soluble solids (TSS), total titratable acidity (TTA), technical maturity index (TMI), and pH) were determined at harvest. The long pruning type presented the highest values for the fresh cluster weight and TSS of the fruits from both varieties and a higher TMI in the Cabernet Sauvignon variety. These results indicate that, under the conditions of the vineyard, long pruning is the most suitable.

Este artículo sirve para iniciarse en las bases docentes de la actual fisiología de la aviación, cuyo origen se remonta al comienzo de la Segunda Guerra Mundial. Bombarderos en picado (1941) de Michael Curtiz es un excelente material docente para ayudar en la comprensión de las distintas causas del síncope de los pilotos en las alturas, permitiendo la reflexión y la búsqueda de soluciones o alternativas a través de experimentos que permiten la recuperación de la homeostasis corporal. Su material audiovisual comparte escenas reales del ejército americano que permiten acceder a estos descubrimientos y al avance del estado actual de la moderna fisiología aeroespacial.