Publicaciones
Geomorphologic Hazards And Disasters In The South American Andes.
Lebedeva, E., Mikhalev, D., Novoa Jerez, J., & Kladovschikova, M.
Geological-and-tectonic and physiographical features of the South American Pacific coast caused high intensity of morpholitogenesis including disaster-like way of some geomorphologic processes. Their complex, interaction, and intensity of conductive factors increase the risk of disaster. The Andean terrain morphology and rock lithology, precipitation type, and vegetation status are the main drivers that influence the character and high potential intensity of the geomorphologic processes. The enormous hydrometeorological events, frequent seismic shocks, volcanic eruptions, and human impact cause disasters development. A schematic map of disaster and hazardous processes for the Central sector of Andes was compiled. 16 areas with different spectra of the dominant catastrophic processes were identified. The South American Andes extension allows drawing out principles of geomorphologic disasters of these continental marginal mountains in various natural zones – from temporal to subequatorial latitudes, which are characterized by the individual unique heat-moisture rate, which governs both typical and extreme geomorphologic processes. An important feature of the study area is the asymmetric distribution of geomorphologic processes within coastal and inland slopes of the mountain system, as well as latitudinal zoning of this distribution.
Año: 2014
Palabras claves: Geomorphologic hazard and disasters, South American Andes, intensity of geomorphologic processes, seismic and volcanic activity, unbalanced precipitation, mass movements of debris
A test of large-scale reproductive migration in females of the amphidromous shrimp Macrobrachium acanthurus (Caridea : Palaemonidae) from south-eastern Brazil.
Bertini, G., Baeza, J., & Perez, E.
Macrobrachium acanthurus inhabits estuaries and rivers in the western Atlantic. It is not clear whether females migrate towards estuaries to hatch larvae, as reported for other congeneric shrimps. We tested whether females of M. acanthurus exhibit reproductive migrations. The population dynamics of this shrimp was studied in the Ribeira de Iguape River, Brazil. Four sites that differ in position with respect to the coast were sampled monthly during 2007. In M. acanthurus, reproduction was seasonal and reproductive intensity did not vary among study sites. Females brooding early and late embryos were found at all study sites during the reproductive season. No disappearance of reproductive females was observed at the study site located furthest away (~150 km) from the coast. Thus, reproductive females of M. acanthurus do not exhibit reproductive migrations towards estuaries to hatch larvae. Maturity in females was reached at smaller body sizes during the austral summer and spring compared with winter and autumn. Growth rate and body size was sex-specific; males grew slower but attained larger average and final body sizes than females. This information needs to be considered in assessing stocks and establishing sustainable management plans for M. acanthurus in Brazil.
Año: 2014
Palabras claves: Freshwater prawn, growth, maturity, reproduction, sex ratio.
Efectos economicos de la estrategia de cosechas multiples en el cultivo del ostion del norte Argopecten purpuratus:una oportunidad para mejorar la competitividad.
Perez, E.
Una situación recurrente en el mercado de muchas especies bajo cultivo acuícola es la tendencia en la disminución del precio internacional en oposición al aumento en los costos de los insumos, lo que obliga a la industria a ser innovadora al momento de rentabilizar la inversión. Una opción poco explorada es el aumento del valor de la producción a través de una cuidadosa selección de tamaños y tiempos de cosechas. Las cosechas parciales permiten que calibres subóptimos puedan tener el tiempo necesario de crecimiento hasta alcanzar mejores atributos, al mismo tiempo que la fracción de mejor crecimiento es cosechada y puesta disponible en el mercado. Difiere significativamente de la estrategia alternativa de cosechas totales, donde la totalidad de la producción es cosechada al mismo tiempo. Así, el óptimo económico será resultado del tiempo de primera cosecha (DPC), de la longitud de cosecha (LC), número de cosechas (NC) e intervalo de tiempo (∆t) entre cosechas sucesivas. Mediante un modelo de simulación, alimentado con valores reales de una empresa de cultivo de ostión del norte (Argopecten purpuratus) se analizó el resultado económico de la estrategia de cosechas múltiples. Los resultados indican que las combinaciones alternativas de DPC, LC, ∆t y NC generan distintos niveles de rendimientos económicos, aspecto que debiera ser considerado por los productores. En los escenarios simulados de cosechas, una decisión incorrecta en este sentido podría generar una diferencia del orden de US$ 510.000.
Año: 2014
Palabras claves: Argopecten purpuratus, ostión del norte, cosechas múltiples, rendimiento económico,acuicultura.
Surface ocean response to synoptic-scale variability in wind stress and heat fluxes off south-central Chile.
Aguirre, C., Garreaud, R., & Rutllant, J.
The effect of the high frequency (synoptic) variability of wind and heat fluxes upon the surface ocean off south-central Chile (west coast of South America) is investigated using a regional ocean model. We focus our analysis in austral summer, when the regional wind experiences significant day-to-day variability superimposed on a mean, upwelling favorable flow. To evaluate the nature and magnitude of these effects, we performed three identical simulations except for the surface forcing: the climatological run, with long-term monthly mean wind-stresses and heat fluxes; the wind-synoptic run, with daily wind stresses and climatological heat fluxes; and the full-synoptic run, with daily wind-stresses and daily fluxes. The mean currents and surface geostrophic EKE fields show no major differences between simulations, and agree well with those observed in this ocean area. Nevertheless, substantially more ageostrophic EKE is found in the simulations which include synoptic variability of wind-stresses, impacting the total surface EKE and diffusivities, particularly south of Punta Lavapie (37° S), where the lack of major currents implies low levels of geostrophic EKE. Summer mean SSTs are similar in all simulations and agree with observations, but SST variability along the coast is larger in the runs including wind-stress synoptic variability, suggesting a rather linear response of the ocean to cycles of southerly wind strengthening and relaxation. We found that coastal SST variability does not change significantly in the first tenths of kilometers from the shore when including daily heat fluxes, highlighting the prominent role of wind-driven upwelling cycles. In contrast, in the offshore region situated beyond the 50 km coastal strip, it is necessary to include synoptic variability in the heat fluxes to account for a realistic SST variability.
Año: 2014
Palabras claves: Atmospheric forcing; Air–sea interaction; Surface currents; Surface temperature; Synoptic variability, Chile.
High hydrostatic pressure effect on chemical composition, color, phenolic acids and antioxidant capacity of Cape gooseberry pulp (Physalis peruviana L.).
Vega-Gálvez, A., López, J., Torres-Ossandón, M., Galotto, M., Puente-Díaz, L., Quispe-Fuentes, I., & Di Scala, K.
The aim of this study was to evaluate the effects of high hydrostatic pressure (HHP) at 300, 400 and 500 MPa/1, 3 and 5 min on nutritional and antioxidant properties of Cape gooseberry pulp after immediate application and after 60 days of storage. Proximal analysis, color, phenolic acids content and antioxidant capacity were determined. When analyzing the immediate effect of different treatments, a clear influence of HHP was observed in all the components of the proximal analysis. Regarding color, none of the three chromatic parameters showed significant differences with control leading to a minimum ΔE at 300 MPa/3 min. Changes in bound and free phenolic acids were evidenced after treatments. The maximum levels of TPC as well as antioxidant capacity were observed at 500 MPa/5 min. By the end of storage, all treated samples discolored leading to ΔE = 14.9 at 500 MPa/5 min. The profile of free and bound phenolic acids presented differences compared to Day 0. The antioxidant capacity by means of ORAC increased for treatments above 300 MPa/5 min indicating the effectiveness of these treatments for the production of functional products based on gooseberry pulp. For treatments above 400 MPa/3 min, molds and yeasts were not detected.
Año: 2014
Palabras claves: High hydrostatic pressure; Antioxidant capacity; Phenolic compounds; Functional foods; Cape gooseberry.
Formulated diets for giant chilean frog Calyptocephalella gayi tadpoles
Toledo, P., Suazo, R., & Viana, M.
In this study, we conducted an experiment to evaluate the overall effect of novel diets on the growth, metamorphosis and survival of tadpoles of the endangered giant Chilean frog Calyptocephalella gayi (previously known as Caudiverbera caudiverbera) to evaluate the potential of this species for culture and repopulation purposes. Using fishmeal as the main protein source with a substitution of either scallop viscera or Spirulina meal, three treatments were formulated to contain similar amounts of protein and energy. The experiment was run for 75 days, after which the tadpoles showed no significant differences among treatments in terms of their growth or survival. This is the first study to report positive effects of different diets on the growth and survival of tadpoles of the giant Chilean frog. Therefore, it might be possible to extend the farming of Calyptocephalella gayi for human consumption and repopulation. Nevertheless, more efforts are needed to understand their nutritional requirements to formulate appropriate diets for this endangered frog.
Año: 2014
Palabras claves: Artificial diet, nutrition, protein sources, Spirulina meal, survival.
Effect of Osmotic Dehydration Under High Hydrostatic Pressure on Microstructure, Functional Properties and Bioactive Compounds of Strawberry (Fragaria Vesca).
Núñez-Mancilla, Y., Vega-Gálvez, A., Pérez-Won, M., Zura, L., García-Segovia, P., & Di Scala, K.
Sliced strawberries were subjected to combined osmotic dehydration (40 °Brix) and high hydrostatic pressure (HHP) at 100, 200, 300, 400 and 500 MPa for 10 min. This research was carried out to study the effects of pressure on firmness, polysaccharides, total dietary fibre and microstructure, functional properties (rehydration ratio and water holding capacity) and bioactive compounds (anthocyanins, flavonoid and total phenolic). HHP affected the texture of the fruits leading to soft fruits due to increasing pressure. Fruit microstructure evidenced influence of pressure presenting the pressurised samples irregular matrices compared to samples treated at 0.1 MPa (control samples). Polysaccharides increased with pressure. Total dietary fibre, anthocyanins, flavonoids and total phenolic content showed a decrease with pressure when compared to control samples. Based on results, minor alterations of the mentioned quality parameters were evidenced when working in the range of 300–500 MPa.
Año: 2014
Palabras claves: Strawberry, High hydrostatic pressure, Osmotic dehydration, Microstructure, Anthocyanins, Firmness.
Influence of process temperature on drying kinetics, physicochemical properties and antioxidant capacity of the olive-waste cake.
Uribe, E., Lemus-Mondaca, R., Vega-Gálvez, A., Zamorano, M., Quispe-Fuentes, I., Pasten, A., & Di Scala, K.
The objective of this study was to determine the effect of drying temperature on the drying kinetics, proximal analysis, energy consumption and the antioxidant capacity of the olive-waste cake “Picual” variety from 40 to 90 °C. Evaluation of proximal analysis evidenced the influence of temperature on the waste parameters. Values of effective moisture coefficients were in the range of 1.97–6.05 × 10−9 m2 s−1 under the studied conditions. Activation energy was found to be 28.24 kJ mol−1. The Weibull model was successfully applied (r2 > 0.973). Specific energy consumption decreased as temperature increased, showing the effect of drying times over temperature. Although dehydrated samples decreased the initial total phenolic content, significant differences were not detected. Effects of drying temperatures did not present significant differences on antioxidant capacity (ORAC and DPPH) when compared to fresh samples. The oleic acid (main fatty acid in fresh samples) presented a maximum increased at 90 °C.
Año: 2014
Palabras claves: Olive-waste cake; Phenolic compounds; Antioxidant activity; Fatty acid profile; Convective dehydration.
Diversity of Quinoa in a Biogeographical Island: a Review of Constraints and Potential from Arid to Temperate Regions of Chile.
Bazile, D., Martínez, E., & Fuentes, F.
Chile, isolated by a hyper-arid desert in the north, the Andes Range to the east and the Pacific and Antarctic waters (west and south), has a highly endemic flora. This hotspot of biodiversity is in danger not only due to increasing desertification, but also because human activities can diminish agrobiodiversity. Quinoa (Chenopodium quinoa Willd.) is an Andean species producing highly nutritious grains, which almost disappeared from Chile during the Spanish colonization. Today less than 300 small-scale and highly isolated farmers still grow it as a rain-fed crop. This review describes the biogeographical-social context of quinoa in Chile, and its high genetic diversity as a product of a long domestication process, resulting in numerous local landraces whose conservation and use for breeding improved varieties is of paramount importance. We suggest the term “lighthouse crop” to emphasize its contribution to small scale ecological and bio diverse agriculture, particularly in stressful environments, to promote a healthier nutrition and more equitable markets in the world. Furthermore this crop and its exceptional nutritional properties were invoked by the United Nations Food and Agriculture Organization (FAO) to promote its use worldwide, and to declare 2013 the International Year of Quinoa.
Año: 2014
Palabras claves: Agrobiodiversity, agroecosystems, Chenopodium quinoa, conservation, cropping systems, lighthouse crop.
Nutritional status affects the capacity of the snail Concholepas concholepas to synthesize Hsp70 when exposed to stressors associated with tidal regimes in the intertidal zone.
Jeno, K. & Brokordt, K.
Synthesis of the heat shock protein Hsp70 is one of the most important physiological mechanisms that intertidal organisms possess to counteract damage to macromolecules caused by stressors associated with the tidal cycle. However, the synthesis and activity of Hsp70 involves an elevated energetic cost. We evaluated the effect of the nutritional status (fed vs. starved for 2 weeks) of juvenile Concholepas concholepas mollusc on their capacity to synthesize Hsp70 during emersion (i.e. low tide) and immersion (i.e. high tide) at high temperatures (24 °C, e.g. summer conditions) and at low temperatures (7 °C, e.g. winter conditions). In addition, we evaluated whether Hsp70 is induced directly upon exposure to stress (emersion) or during recovery (re-immersion). Starvation decreased the content of stored energy substrates of juveniles as well as their ability to synthesize Hsp70 during emersion under thermal stress, especially at high temperatures. Additionally, analysis of environmental factors associated with laboratory simulation of tidal regimes indicated that juveniles in starvation, in contrast to fed juveniles, did not significantly increase their levels of Hsp70 during cold emersion (7 °C) or warm emersion (24 °C) or upon re-immersion. Induction of Hsp70 occurred during exposure to stress (low-tide conditions) and not when juveniles returned to “normal” conditions (high-tide conditions). Thus, the synthesis of Hsp70 for the juveniles of this intertidal snail species was coordinated and adapted to the tidal cycle, and the species responds in a similar way to hot and cold emersion conditions. The observed levels of Hsp70 reflect the ability of the individual to synthesize these proteins, which is dependent on the nutritional status of the individual.
Año: 2014
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