1,721,023 research outputs found
Plan de marketing : lanzamiento tapas “Gluten Free” La Salteña
Full text linkFil: Rodriguez, Maria Victoria. Universidad de San Andrés. Escuela de Negocios; Argentina
De especie vulnerable a 16 por km2
No full textGracias a la protección efectiva de la Reserva de Vida Silvestre San Pablo de Valdés en Chubut la población de guanacos se incrementó, al igual que la cobertura vegetal dentro de la reserva. Este artículo resume los resultados obtenidos luego de los primeros años de monitoreo de la comunidades vegetales y la población de guanacos en San Pablo de Valdés, luego de su conversión de establecimiento ganadero dedicado a la producción ovina a reserva de vida silvestre.Fil: Rodriguez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pazos, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arias, Alejandro. Fundacion Vida Silvestre Argentina; Argentin
On resource defense and sustainable grazing: Forage use by territorial and non-territorial guanaco groups
Full text linkRecent studies suggest that territorial defense can act as a regulating agent of herbivore density, buffering crowding effects and preventing vegetation depletion. The occurrence of territorial families and non-territorial male groups, both major social units in the social organization of guanacos, offers the unusual opportunity to test predictions about the role of territorial defense in buffering grazing impact. Under the hypothesis that forage use by guanacos in family groups would be less intense than that of male groups which lack territorial defense, we predicted that plant cover will be higher in areas used exclusively by family groups compared to that in areas used by male groups. The vegetation and the guanaco population at San Pablo reserve were being monitored for eight years showing that grass foliar and basal cover were reduced when non-territorial groups started using the monitored area, which was previously used exclusively by family groups. On a broader scale comparison, grass and basal cover were higher in areas used by territorial animals than in those used by non-territorial ones. The approximate area used intensively by the non-territorial groups represents less than 18% of the surveyed area, whereas most of the reserve is exposed to less intense use by the territorial family groups. Thus, temporal and spatial comparisons support the idea that the resource-defense system lowers the disturbance rate over vegetation resources by guanaco populations when compared with other ungulates lacking territorial behavior.Fil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Rodriguez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin
Guanacos: contributions to the study of population-regulation mechanisms and their links to resource availability
Full text linkEl principal objetivo del monitoreo de guanacos de la Reserva de Vida Silvestre San Pablo de Valdés (RSPV) es generar información útil para el manejo de la reserva, con énfasis en una línea de base y seguimiento posterior que permita registrar cambios poblacionales y comportamentales luego del cese de la actividad ganadera y la implementación del área protegida. En este capítulo se presentan resultados obtenidos a partir de dicho seguimiento, en combinación con proyectos de investigación desarrollados en el área durante 10 años de trabajo. Se resume información sobre el crecimiento poblacional, la organización social, el reclutamiento y la habituación a la presencia de vehículos. También se reportan patrones de distribución espacial y sus relaciones con la disponibilidad de alimento, así como la variabilidad en la capacidad de carga de las principales comunidades vegetales de la RSPV. Por último, se interpretan los resultados obtenidos a la luz de las hipótesis de regulación poblacional y se discuten las implicanciasde los mismos para el manejo y la conservación de las poblaciones de guanacos y los pastizales patagónicos.The main goal of the guanaco monitoring program at the Reserva de Vida Silvestre San Pablo de Valdés (RSPV) is to generate relevant information to support management decisions, with emphasis on a baseline and the subsequent monitoring to allow the detection of population and behavioral changes after the creation of the reserve. In this chapter we present the results obtained after 10 years of combined effort between this program and several research projects conducted in the area. We report results on population growth, social organization, recruitment and habituation to motorized vehicles. We also report local spatial patterns and their link to food availability and the variability in the carrying-capacity of the main vegetation communities in the RSPV. Finally, we interpret our findings in the light of the hypotheses of population regulation and discuss their implications in terms of management and conservation of guanaco populations and Patagonian grasslands.Fil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Rodriguez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; Argentin
Spatial patterns and chemical characteristics of root biomass in ecosystems of the Patagonian Monte disturbed by grazing
Full text linkWe hypothesized that the reduction in perennial-grass cover induced by grazing in shrublands would be associated with a reduction in fine-root biomass in the upper soil, an increase in the spatial heterogeneity of root biomass, and an increase in N and total phenolics concentrations in fine-root biomass. We analysed the spatial distribution of fine-, intermediate-, and thick-root biomass and the N and total phenolics concentrations in fine roots in sites with different aboveground-plant cover induced by grazing disturbance in the Patagonian Monte. We selected sampling sites varying in the distance to the watering point, the time since sheep grazing exclusion, and historical sheep stocking rates/paddock characteristics. Sites excluded from grazing and those far to the watering point showed the highest perennial-grass cover. Tall- and dwarf-shrub cover did not differ among sites. Fine-, intermediate-, and thick-root biomass and the chemistry of fine roots did not strongly differ among sites. At all sites, N concentration in fine roots was similar to that measured in tall shrubs while total phenolics concentration in fine roots fell within the range of that assessed for perennial grasses and tall shrubs. Results on N concentration would indicate that fine roots of tall shrubs are a main component of the bulk fine-root pool supporting previous evidence that life form shifts resulting from grazing has little effect on the root biomass and chemistry in the upper soil of rangelands.Fil: Rodriguez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Bertiller, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Sain, Claudia Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin
Resource-defense polygyny and self-limitation of population density in free-ranging guanacos
Full text linkAlthough ecologists and managers have been increasingly preoccupied with the crowding consequences of overabundant herbivores,the potential role of territorial behavior as a self-regulatory agent has seldom been considered. The crowding mechanism underlies most regulation models in ungulate demography and relies on the assumption of an equal share of available supplies among individuals. In contrast, in territorial systems dominant individuals monopolize resources, predicting deviations from the expected demographic outcomes under the crowding approach. We used empirical data on a protected guanaco (Lama guanicoe) population to test competing hypotheses about crowding and territorial defense as the mechanism driving density regulation in a resource-defense polygyny ungulate. We assessed density dependence on recruitment at different spatial scales and density effects on preferred forage availability. The guanaco density inside the reserve increased rapidly and then stabilized during the last third of the study period. The absence of density effects on recruitment questions the existence of crowding mechanisms. Guanaco numbers stabilized belowthe environmental carrying capacity predicted by an equal share of available forage, supporting territorial defense as the mechanism shaping population density in the area. Variability in forage cover was independent from changes in population density, rejecting crowding effects on food supplies. These results are consistent with the hypothesis of a self-regulatory mechanism derived fromresource defense that may prevent overgrazing. Our findings suggest that other factors in addition to food availability may determine the demographic carrying capacity under resource defense systems, stressing the importance of accounting for behavioral traits when addressing management issues.Fil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Rodriguez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Pazos, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin
Temporal asynchrony in fine-root biomass may contribute to shrub and grass coexistence in mixed patches
No full textWe described seasonal changes in fine-root biomass of a grass and a shrub dominant species in a plant community characteristic of the arid Patagonian Monte and then we inferred to want extent the observed differences could contribute to the species coexistence. We selected representative plant patches of the natural vegetation arrangement consisting of one isolated plant of the dominant shrub Larrea divaricata (Ld), grass patches formed by one or more bunches of the dominant grass Nassella tenuis (Nt), and mixed patches consisting of one individual of L. divaricata with bunches of N. tenuis under its canopy (LdNt). We assessed the biomass and temporal changes in fine roots of each species in the upper soil (50 cm depth) of each patch type at three-month intervals during 2 years. The temporal series of fine-root biomass were compared among patch types and in relation to above-ground phenology, as well as climate variables (precipitation, arid index and air temperature). Seasonal changes in fine-root biomass showed similar cycles in the three plant patches with a maximum in spring. The maximum increase in root biomass in Ld and Nt patches occurred during the onset of reproductive growth in winter and spring, respectively. Fine-root changes in LdNt patches mimicked that in Ld patches. Precipitation inputs were significantly positively and temperature negatively related to fine-root changes in Nt patches. Fine-root changes in Ld and LdNt patches were related to the aridity index (positively) and temperature (negatively). We concluded that the observed asynchronies in the date of the largest increases in root biomass and its climate control between the studied grass and shrub species could contribute to the coexistence of plants of both life forms when they overlap their root systems growing in mixed patches. Mechanisms underlying the root patterns observed should be further explored.Fil: Rodriguez, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Bertiller, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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