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High hydrostatic pressure effect on chemical composition, color, phenolic acids and antioxidant capacity of Cape gooseberry pulp (Physalis peruviana L.).

Autores:

Vega-Gálvez, A., López, J., Torres-Ossandón, M., Galotto, M., Puente-Díaz, L., Quispe-Fuentes, I., & Di Scala, K.

Resumen:

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.

Referencia APA: Vega-Gálvez, A., López, J., Torres-Ossandón, M., Galotto, M., Puente-Díaz, L., Quispe-Fuentes, I., & Di Scala, K. (2014). High hydrostatic pressure effect on chemical composition, color, phenolic acids and antioxidant capacity of Cape gooseberry pulp (Physalis peruviana L.). LWT - Food Science And Technology, 58(2), 519-526.

Geomorphologic Hazards And Disasters In The South American Andes.

Autores:

Lebedeva, E., Mikhalev, D., Novoa Jerez, J., & Kladovschikova, M.

Resumen:

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

Referencia APA: Lebedeva, E., Mikhalev, D., Novoa Jerez, J., & Kladovschikova, M. (2014). Geomorphologic Hazards And Disasters In The South American Andes. Ges, 7(1), 80-98.

Recession flow analysis as a suitable tool for hydrogeological parameter determination in steep, arid basins.

Autores:

Oyarzún, R., Godoy, R., Núñez, J., Fairley, J., Oyarzún, J., Maturana, H., & Freixas, G

Resumen:

The analysis of baseflow recession of streamflow has been widely used in the evaluation of basin scale parameters because the required data are inexpensive to acquire, and the method is easy to use and generally gives good results. A literature review, however, shows that few studies have examined the applicability of recession methods to arid basins, particularly those set in mountainous landscapes. In this study, we apply a recession method that uses a non-dimensional theoretical curve matching technique to evaluate basin-wide, spatially-averaged hydraulic parameters for several watersheds (Culebrón, Punitaqui, Valle Hermoso, Hurtado, Chalinga, and Camisas), taking as case of study the Coquimbo Region, an arid, mountainous territory with steep topography in North-Central Chile. The studied watersheds range from 200 to 1500 km2. Results show hydraulic conductivity values in a reasonable range, i.e., 10−4 to 10−6 m s−1, rather close to those reported in the few existing studies for some of the basins. The method also yields estimates on the order of 10−5 for drainable porosity, with no major differences between the basins. The recession flow analysis provides a cost-effective approach to obtaining bulk hydrological parameters in arid and semi-arid steep basins such as those of the Coquimbo Region and elsewhere.

Año: 2014

Palabras claves: Boussinesq equation; Coquimbo Region; Drainable porosity; Hydraulic conductivity; Hydrogeology.

Referencia APA: Oyarzún, R., Godoy, R., Núñez, J., Fairley, J., Oyarzún, J., Maturana, H., & Freixas, G. (2014). Recession flow analysis as a suitable tool for hydrogeological parameter determination in steep, arid basins. Journal Of Arid Environments, 105, 1-11

On the use of Standardized Drought Indices under decadal climate variability: Critical assessment and drought policy implications.

Autores:

Núñez, J., Rivera, D., Oyarzún, R., & Arumí, J.

Resumen:

Since the recent High Level Meeting on National Drought Policy held in Geneva in 2013, a greater concern about the creation and adaptation of national drought monitoring systems is expected. Consequently, backed by international recommendations, the use of Standardized Drought Indices (SDI), such as the Standardized Precipitation Index (SPI), as an operational basis of drought monitoring systems has been increasing in many parts of the world. Recommendations for the use of the SPI, and consequently, those indices that share its properties, do not take into account the limitations that this type of index can exhibit under the influence of multidecadal climate variability. These limitations are fundamentally related to the lack of consistency among the operational definition expressed by this type of index, the conceptual definition with which it is associated and the political definition it supports. Furthermore, the limitations found are not overcome by the recommendations for their application. This conclusion is supported by the long-term study of the Standardized Streamflow Index (SSI) in the arid north-central region of Chile, under the influence of multidecadal climate variability. The implications of the findings of the study are discussed with regard to their link to aspects of drought policy in the cases of Australia, the United States and Chile.

Año: 2014

Palabras claves: Multidecadal climate variability; Drought; Standardized Precipitation Index; Drought policy; Pacific Decadal Oscillation; Arid zones.

Referencia APA: Núñez, J., Rivera, D., Oyarzún, R., & Arumí, J. (2014). On the use of Standardized Drought Indices under decadal climate variability: Critical assessment and drought policy implications. Journal Of Hydrology, 517, 458-470.

Climate and soil attributes determine plant species turnover in global drylands.

Autores:

Ulrich, W., Soliveres, S., Maestre, F., Gotelli, N., Quero, J., & Delgado-Baquerizo, M. Bowker, M.A., Eldridge, D.J., Ochoa, V., Gozalo, B., Valencia, E., Berdugo, M., Escolar, C., García-Gómez, M., Escudero, A., Prina, A., Alfonso, G., Arredondo, T., Bran, D., Cabrera, O., Cea, A.P., Chaieb, M., Contreras, J., Derak, M., Espinosa, C.I., Florentino, A., Gaitán, J., García Muro, V., Ghiloufi, W., Gómez-González, S., Gutiérrez, J.R., et al.

Resumen:

Geographical, climatic and soil factors are major drivers of plant beta diversity, but their importance for dryland plant communities is poorly known. The aim of this study was to: (1) characterize patterns of beta diversity in global drylands; (2) detect common environmental drivers of beta diversity; and (3) test for thresholds in environmental conditions driving potential shifts in plant species composition.

Año: 2014

Palabras claves: Aridity; beta diversity; climatic variability; global environmental change; habitat filtering; latitudinal gradient; plant community assembly; regression analysis; soil fertility; spatial soil heterogeneity.

Referencia APA: Ulrich, W., Soliveres, S., Maestre, F., Gotelli, N., Quero, J., & Delgado-Baquerizo, M. Bowker, M.A., Eldridge, D.J., Ochoa, V., Gozalo, B., Valencia, E., Berdugo, M., Escolar, C., García-Gómez, M., Escudero, A., Prina, A., Alfonso, G., Arredondo, T., Bran, D., Cabrera, O., Cea, A.P., Chaieb, M., Contreras, J., Derak, M., Espinosa, C.I., Florentino, A., Gaitán, J., García Muro, V., Ghiloufi, W., Gómez-González, S., Gutiérrez, J.R., et al. (2014). Climate and soil attributes determine plant species turnover in global drylands. Journal Of Biogeography, 41(12), 2307-2319.

Functional traits determine plant co-occurrence more than environment or evolutionary relatedness in global drylands.

Autores:

Soliveres, S., Maestre, F., Bowker, M., Torices, R., Quero, J., & García-Gómez, M., Cabrera, O., Ceag, A.P., Coaguila, D., Eldridge D.J., Espinosa, C.I., Hemmings, F., Monerris, J.J., Tighe, M., Delgado-Baquerizo, M., Escolar, C., García-Palacios, P., Gozalo, B., Ochoa, V., Blones, J., Derak, M., Ghiloufi, W., Gutiérrez, J.R., Hernández, R.M., Noumi, Z.

Resumen:

Plant–plant interactions are driven by environmental conditions, evolutionary relationships (ER) and the functional traits of the plants involved. However, studies addressing the relative importance of these drivers are rare, but crucial to improve our predictions of the effects of plant–plant interactions on plant communities and of how they respond to differing environmental conditions. To analyze the relative importance of – and interrelationships among – these factors as drivers of plant–plant interactions, we analyzed perennial plant co-occurrence at 106 dryland plant communities established across rainfall gradients in nine countries. We used structural equation modelling to disentangle the relationships between environmental conditions (aridity and soil fertility), functional traits extracted from the literature, and ER, and to assess their relative importance as drivers of the 929 pairwise plant–plant co-occurrence levels measured. Functional traits, specifically facilitated plants’ height and nurse growth form, were of primary importance, and modulated the effect of the environment and ER on plant–plant interactions. Environmental conditions and ER were important mainly for those interactions involving woody and graminoid nurses, respectively. The relative importance of different plant–plant interaction drivers (ER, functional traits, and the environment) varied depending on the region considered, illustrating the difficulty of predicting the outcome of plant–plant interactions at broader spatial scales. In our global-scale study on drylands, plant–plant interactions were more strongly related to functional traits of the species involved than to the environmental variables considered. Thus, moving to a trait-based facilitation/competition approach help to predict that: (1) positive plant–plant interactions are more likely to occur for taller facilitated species in drylands, and (2) plant–plant interactions within woody-dominated ecosystems might be more sensitive to changing environmental conditions than those within grasslands. By providing insights on which species are likely to better perform beneath a given neighbour, our results will also help to succeed in restoration practices involving the use of nurse plants.

Año: 2014

Palabras claves: Aridity; Competition; Facilitation; Phylogenetic distance; Semi-arid; Soil fertility.

Referencia APA: Soliveres, S., Maestre, F., Bowker, M., Torices, R., Quero, J., & García-Gómez, M., Cabrera, O., Ceag, A.P., Coaguila, D., Eldridge D.J., Espinosa, C.I., Hemmings, F., Monerris, J.J., Tighe, M., Delgado-Baquerizo, M., Escolar, C., García-Palacios, P., Gozalo, B., Ochoa, V., Blones, J., Derak, M., Ghiloufi, W., Gutiérrez, J.R., Hernández, R.M., Noumi, Z. (2014). Functional traits determine plant co-occurrence more than environment or evolutionary relatedness in global drylands. Perspectives In Plant Ecology, Evolution And Systematics, 16(4), 164-173.

Seed predation by rodents results in directed dispersal of viable seed fragments of an endangered desert shrub.

Autores:

Loayza, A., Carvajal, D., García-Guzmán, P., Gutierrez, J., & Squeo, F.

Resumen:

Seed predation and seed dispersal are important ecological processes with antagonistic effects on plant recruitment. In the southern edge of the Atacama Desert in Chile, Myrcianthes coquimbensis is an endangered, large-seeded, vertebrate-dispersed shrub that in the present-day has no known dispersers. Native rodents hoard and eat the seeds of M. coquimbensis but leave viable seed fragments at the hoarding sites; soil interspaces within rock outcrops where seedlings recruit. Here we examined whether rodents act as effective dispersers of M. coquimbensis by discarding viable seed fragments in sites suitable for recruitment. We simulated different levels of endosperm loss to determine if seedlings could develop from seed fragments. We assessed how frequently rodents discarded fragments, and the probability that these fragments produced seedlings. Finally, we compared emergence and seedling survival at the hoarding sites and in two other habitats where seeds arrive to evaluate the suitability of the hoarding sites. Seeds of M. coquimbensis developed seedlings even after 87% of their storage tissue was removed. Rodents left seed fragments in more than 50% of the trials; almost 60% of the discarded fragments produced seedlings. Seedlings did not emerge from open ground habitats, and emergence was higher under M. coquimbensis shrubs than in rock habitats. Survival of two-year-old seedlings was higher in rock habitats than under conspecific adult shrubs. Our results suggest that rodents may play a dual role in the recruitment dynamics of M. coquimbensis, acting simultaneously as seed predators and effective dispersers. Therefore, though seed predators impose costs, their net effect on plant fitness in this system—where dispersers of large-seeded species have been lost—is likely positive.

Año: 2014

Palabras claves: Anachronism; Atacama; captive feeding trials; hoarding; Myrcianthes coquimbensis; rodent; seedling establishment.

Referencia APA: Loayza, A., Carvajal, D., García-Guzmán, P., Gutierrez, J., & Squeo, F. (2014). Seed predation by rodents results in directed dispersal of viable seed fragments of an endangered desert shrub. Ecosphere, 5(4), art43.

Using stakeholders’ perspective of ecosystem services and biodiversity features to plan a marine protected area.

Autores:

Cárcamo, P., Garay-Flühmann, R., Squeo, F., & Gaymer, C.

Resumen:

The definition of a common vision that includes social and environmental goals, ecosystem services and/or biodiversity features that people are interested in maintaining or restoring is a great challenge for marine protected areas (MPAs). Recent initiatives have promoted broadening the focus from biodiversity conservation alone to the conservation of both ecosystem services and biodiversity, indicating that this integration should improve support and compliance from stakeholders. Using a Multiple-Use Coastal Marine Protected Area recently proposed in northern Chile, we investigated (i) stakeholders’ perceptions of the valuation of ecosystem services, threats to their provision, and the prioritization of ecosystem services, biodiversity features, and uses in a planning scenario, and (ii) stakeholders’ expectations for the establishment of a new MPA. The perceptions of different groups of stakeholders were compared and statistically analyzed, and the relationships among prioritizations were studied using a network approach. Stakeholders identified and valued 13 ecosystem services, 28 biodiversity features, 20 uses and activities, and 22 threats. Significant differences among the valuations and prioritizations of different stakeholder groups were attributable principally to artisanal fishermen's perceptions of some components that are directly related to their activities and livelihoods. High expectations of benefits from a new MPA implementation were observed for all categories of stakeholders. To relate the different valuated components, we proposed a network-based conceptual model that reduces complexity, and also as a strategy to communicate relationships and trade-offs occurring in this particular social–ecological system to the several stakeholders. We strongly recommend early stakeholder engagement so as to understand the variability in environmental perceptions and then reflect that variation in the planning and management actions of MPAs, thus improving support for their implementation and achieving conservation and societal goals. Our findings indicate that stakeholders’ perceptions and prioritizations of ecosystem services, biodiversity features and uses should be used as the basis for starting the MPA implementation and planning process.

Año: 2014

Palabras claves: Biodiversity; Chile; Ecosystem services; Fishermen; Multiple-Use Coastal Marine Protected Area; Stakeholders’ perceptions.

Referencia APA: Cárcamo, P., Garay-Flühmann, R., Squeo, F., & Gaymer, C. (2014). Using stakeholders’ perspective of ecosystem services and biodiversity features to plan a marine protected area. Environmental Science & Policy, 40, 116-131

Estudios socio-ecológicos de largo plazo en los sitios fundadores de la red LTSER-Chile: desafíos y oportunidades para el futuro.

Autores:

Gaxiola, A., Celis-Diez, J., Rozzi, R., & Gutiérrez, J.

Resumen:

The research carried out in the three foundational sites of the Chilean Long-Term Socio-Ecological Research Network (LTSER-Chile) aims to answer questions that reflect the regional context in which each site is immersed. The formation of the network in 2008 provided an opportunity to establish comparative studies and analyse the effects of the different components of global change could exert on different ecosystems in Chile. This study presents an analysis of the research programs of each of the three sites and presents the context in which these lines have been established. Each founder site has identified key aspects associated with local needs and the interests of the research groups that initiated and have directed the ecological or socio-ecological long-term studies. At the national scale these different approaches are complementary. First, we present an analysis and evaluation of the research conducted by each of these groups. Then, we develop a diagnosis of the research developed at each of the sites during the last two decades with the goal of identifying gaps and future research opportunities. Furthermore, this characterization will contribute to addressing the challenges and opportunities in basic and applied long-term socio-ecological research.

Año: 2014

Palabras claves: Global change, climatic change, Cape Horn, Chiloé, Fray Jorge National Park.

Referencia APA: Gaxiola, A., Celis-Diez, J., Rozzi, R., & Gutiérrez, J. (2014). Estudios socio-ecológicos de largo plazo en los sitios fundadores de la red LTSER-Chile: desafíos y oportunidades para el futuro. Bosque (Valdivia), 35(3), 421-428.

Influence of process temperature on drying kinetics, physicochemical properties and antioxidant capacity of the olive-waste cake.

Autores:

Uribe, E., Lemus-Mondaca, R., Vega-Gálvez, A., Zamorano, M., Quispe-Fuentes, I., Pasten, A., & Di Scala, K.

Resumen:

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.

Referencia APA: Uribe, E., Lemus-Mondaca, R., Vega-Gálvez, A., Zamorano, M., Quispe-Fuentes, I., Pasten, A., & Di Scala, K. (2014). Influence of process temperature on drying kinetics, physicochemical properties and antioxidant capacity of the olive-waste cake. Food Chemistry, 147, 170-176.

Effect of Osmotic Dehydration Under High Hydrostatic Pressure on Microstructure, Functional Properties and Bioactive Compounds of Strawberry (Fragaria Vesca).

Autores:

Núñez-Mancilla, Y., Vega-Gálvez, A., Pérez-Won, M., Zura, L., García-Segovia, P., & Di Scala, K.

Resumen:

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.

Referencia APA: Núñez-Mancilla, Y., Vega-Gálvez, A., Pérez-Won, M., Zura, L., García-Segovia, P., & Di Scala, K. (2014). Effect of Osmotic Dehydration Under High Hydrostatic Pressure on Microstructure, Functional Properties and Bioactive Compounds of Strawberry (Fragaria Vesca). Food Bioprocess Technol, 7(2), 516-524.

Morphogenesis by mass movements in western Andes (Chile).

Autores:

Novoa Jerez, J.

Resumen:

Numerous examples of mass movements on slopes of western Andes and related landforms are analyzed. Regionalization of the country is fulfilled, taking into account climatic and hydrologic factors. 9 regions were distinguished with more or less similar physical-geographical conditions for mass movements’ development. Recommendations are suggested concerning future investigations in the field of mass movements risk under the rising anthropogenic impact.

Año: 2013

Palabras claves: ground mass movements, slope, morphogenesis, the Andes, zoning, risk, danger, anthropogenic impact.

Referencia APA: Novoa Jerez, J. (2013). Morphogenesis by mass movements in western Andes (Chile). Geomorfologiâ (Mosk.), (2), 81