El objetivo principal de la tesis es evaluar, mediante el Análisis de Ciclo de Vida (ACV), los impactos ambientales y la demanda de energía y agua de la futura producción de biodiésel en Chile y de ...sus cultivos energéticos asociados, colza y girasol, bajo diferentes opciones de producción a escala nacional, en el corto plazo. Los objetivos adicionales son determinar las etapas críticas en el ciclo de vida del biodiésel, de colza y de girasol y evaluar ambientalmente opciones de mejora en la producción del biocombustible, usando recursos locales o renovables.En el inventario del ACV se emplearon datos agrícolas nacionales y se adaptaron datos de procesos de bases de datos internacionales a condiciones locales. Se evaluó el efecto de las emisiones de oxido nitroso asociadas a aplicación de fertilizantes y el efecto del cambio de uso de suelo.Los resultados indican que la producción de colza en Chile presenta mejor perfil ambiental y menor demanda de agua y de energía comparada con el cultivo de girasol. En ambos cultivos, los fertilizantes minerales aportan la mayor contribución a las cargas ambientales. Los principales sistemas de labranza de colza en Chile, labranza tradicional y labranza cero, presentan similar demanda de energía y perfil de impactos ambientales.Esta tesis muestra que la futura producción de biodiésel de colza en Chile, en un escenario base bajo las condiciones de producción más probables, presenta menor impacto que el diésel fósil en potencial de calentamiento global (PCG), demanda de energía, agotamiento de la capa de ozono y agotamiento de recursos abióticos. El PCG del biodiésel en este escenario es 2,1 kg CO2 equiv./kg, representando un 40% de ahorro de emisiones de efecto invernadero con respecto al diésel. En la demanda de energía, el biodiésel muestra un 62% de ahorro con relación al diésel y una eficiencia energética igual a 2,1. Sin embargo, el biodiésel presenta mayor impacto en 7 indicadores, tales como, acidificación, demanda de agua, eutrofización y los asociados a ecotoxicidad terrestre y acuática. Los impactos del biodiésel están dominados por la etapa de producción de colza.Para disminuir los impactos ambientales de biodiésel de colza en Chile se planteó una estrategia de producción asociada al uso de recursos locales o renovables, bajo el enfoque de la ecología industrial. Se analizaron 4 escenarios alternativos dentro de esta estrategia. La aportación de fertilizantes orgánicos ganaderos, con la correspondiente disminución de fertilizantes minerales, es el escenario con mayor reducción de impactos ambientales. El uso residuos forestales industriales, como fuente de energía para las plantas de biodiésel, y el transporte del biodiésel vía ferrocarril, también son escenarios recomendados desde el punto de vista ambiental. Otro escenario de importancia está asociado a la producción de colza en praderas muy degradadas. El escenario integrado, que combina a los cuatro escenarios alternativos, muestra que los impactos del biodiésel disminuirían entre 5% y 58% respecto al escenario base. Los escenarios alternativos podrían aplicarse en el corto plazo pero previamente deben estar respaldados por estudios económicos y sociales.La futura investigación sobre mejoras en el perfil ambiental del biodiésel de primera generación, tanto en Chile como en otros países de Sudamérica, puede enfocarse en la etapa agrícola, etapa clave en el perfil ambiental del biocombustible; especialmente las prácticas de fertilización, fuentes de fertilizantes y herbicidas y reducción de emisiones de campo de los agroquímicos.Todos los resultados de la tesis se encuentran publicados o en proceso de publicación en revistas científicas internacionales de revisión por pares.
The main objective of the thesis is to evaluate the environmental impacts and energy and water demand of the future production of biodiesel in Chile and of its associated energy crops, sunflower and rapeseed, under different options of production, on a national scale. Additional objectives are to identify the most important environmental loads of these energy systems and to evaluate options for improvement in the biodiesel supply chain, taking into consideration a strategy of production using renewable or local resources.National agricultural data are used for the LCA inventory and process data of international databases are adapted to local conditions. The effect of field nitrous oxide emissions and land use change (LUC) is evaluated.The results of this thesis indicate that rapeseed production in Chile has a better environmental performance and lower water and energy demand, compared to sunflower. Mineral fertilizers cause the highest environmental impact in both crops. The main tillage systems of Chilean rapeseed production, conventional tillage and zero tillage, present similar energy demand and environmental impacts profile.This thesis indicates that future production of biodiesel from rapeseed grown in Chile, in a standard scenario with the most likely productions conditions and technology, has less impact than fossil diesel in global warming, energy demand, ozone layer depletion and abiotic depletion. The global warming potential of biodiesel in this scenario is 2.1 kg CO2 equivalents/kg: a 40% greenhouse gas emissions saving compared to fossil diesel. For energy demand, biodiesel presents an energy saving of 62% in comparison to the fossil diesel reference, with an energy efficiency of 2.1, measured as the energy output/input ratio. However, biodiesel has greater impact in seven categories; for example, acidification, water demand, eutrophication and those linked to terrestrial and marine ecotoxicity. The major impacts of the biodiesel are in the rapeseed production stage.In order to reduce the environmental impact and improve the life cycle stages of biodiesel in Chile, it appears that a production strategy involving local, renewable resources should be used, with an industrial ecology approach. Four alternative scenarios were investigated. The use of animal manure, with a corresponding reduction in mineral fertilizer, has the greatest reduction in impacts. The use of industrial forest residues as an energy source for biodiesel plants and using the railway to transport the biodiesel are also recommended from the environmental point of view. The use of highly degraded grassland for rapeseed cultivation is also important, as this option reduces greenhouse gas emissions by 22% compared to using non-degraded grassland. By combining the four scenarios, the impacts of the biodiesel are reduced by between 5% and 58% compared to the standard scenario. The alternative settings could be used in the short term, but should be backed up by economic and social studies.
Carbon footprint of premium quality export bananas: Case study in Ecuador, the world's largest exporter Iriarte, Alfredo; Maria Gabriela AlmeidaauthorDepartment of Agricultural Economics, Faculty of Agricultural Sciences, Universidad de Talca, Casilla 747, Talca, Chile; Pablo VillalobosauthorDepartment of Agricultural Economics, Faculty of Agricultural Sciences, Universidad de Talca, Casilla 747, Talca, Chile
2015
Journal Article
The Muaco and Taima-Taima sites, in Falcón State of northwestern Venezuela, are among the earliest sites of human occupation in South America containing artifacts associated with preserved megafaunal ...remains and dating between 19,810 and 15,780 calybp. Here we report novel visual and CT scanning analysis of six glyptodont skulls of
Glyptotherium
cf.
cylindricum
from these sites, of which four exhibit distinct and similar patterns of breakages in the fronto-parietal region that suggest intentional blows by direct percussion by humans, with fractures not being diagenetic but instead antemortem or transmortem. This hypothesized and unreported hunting technique focused in an area of the skull where the cephalic shield becomes thin, thus increasing the effectiveness of the blow. From Taima-Taima other glyptodont remains included an inverted carapace, also previously reported as probable evidence of human–glyptodont interaction during the latest Pleistocene. We estimated that roughly 150-170 Kg of potentially accessible muscles and fat of an adult
Glyptotherium cylindricum
could be used as food sources.
Cellular transformation and cancer progression is accompanied by changes in the metabolic landscape. Master co-regulators of metabolism orchestrate the modulation of multiple metabolic pathways ...through transcriptional programs, and hence constitute a probabilistically parsimonious mechanism for general metabolic rewiring. Here we show that the transcriptional co-activator peroxisome proliferator-activated receptor gamma co-activator 1α (PGC1α) suppresses prostate cancer progression and metastasis. A metabolic co-regulator data mining analysis unveiled that PGC1α is downregulated in prostate cancer and associated with disease progression. Using genetically engineered mouse models and xenografts, we demonstrated that PGC1α opposes prostate cancer progression and metastasis. Mechanistically, the use of integrative metabolomics and transcriptomics revealed that PGC1α activates an oestrogen-related receptor alpha (ERRα)-dependent transcriptional program to elicit a catabolic state and metastasis suppression. Importantly, a signature based on the PGC1α-ERRα pathway exhibited prognostic potential in prostate cancer, thus uncovering the relevance of monitoring and manipulating this pathway for prostate cancer stratification and treatment.
The puma (Puma concolor) is widely distributed in the alpine highlands of the Andes, but its diet has rarely been described in ecosystems above 4300 m. We collected and examined 21 puma scats from ...the Salinas y Aguada Blanca National Reserve (RNSAB) between 2013 and 2015. We identified 10 species of prey, in addition to unidentified birds and small rodents. Small and medium animals were the most frequent prey, although wild camelids contributed the greatest proportion of biomass. We also recorded the presence of mesopredators and domestic dogs in puma scats. Our results suggest that the puma could play a key role in the configuration of trophic networks in the RNSAB, and that this can contribute considerably to the ecosystem balance.
The objective is to investigate the relation between cord blood mercury concentrations and child neurobehavioural functioning assessed longitudinally during childhood until pre-adolescence.
The study ...involves mothers and their offspring engaged in the Spanish INMA birth cohort (n = 1147). Total mercury (THg) was determined in cord blood. Behavioural problems were assessed several times during childhood using the ADHD-DSM-IV at age 4, SDQ at ages 7 and 11, CPRS-R:S and the CBCL at ages 7, 9 and 11. Covariates were obtained through questionnaires during the whole period. Multivariate generalised negative binomial (MGNB) models or mixed-effects MGNB (for those tests with information at one or more time points, respectively) were used to investigate the relation between cord blood THg and the children's punctuations. Models were adjusted for prenatal fish intake. Effect modification by sex, prenatal and postnatal fish intake, prenatal fruit and vegetable intake, and maternal polychlorinated biphenyl concentrations (PCBs) was assessed by interaction terms.
The geometric mean ± standard deviation of cord blood THg was 8.22 ± 2.19 μg/L. Despite adjusting for fish consumption, our results did not show any statistically significant relationship between prenatal Hg and the children's performance on behavioural tests conducted between the ages of 4 and 11. Upon assessing the impact of various factors, we observed no statistically significant interaction.
Despite elevated prenatal THg exposure, no association was found with children's behavioural functioning assessed from early childhood to pre-adolescence. The nutrients in fish could offset the potential neurotoxic impact of Hg. Further birth cohort studies with longitudinal data are warranted.
•The Spanish INMA cohort presented elevated prenatal exposure to Hg.•No relation was found between Hg and child behaviour from ages 4 to 11.•No influence of fish, fruit, and vegetable intake, sex or prenatal PCBs was observed.
The purpose of this investigation was to develop an exploratory two-step level A IVIVC for three telmisartan oral immediate release formulations, the reference product Micardis, and two generic ...formulations (X1 and X2). Correlation was validated with a third test formulation, Y1. Experimental solubility and permeability data were obtained to confirm that telmisartan is a class II compound under the Biopharmaceutic Classification System. Bioequivalence (BE) studies plasma profiles were combined using a previously published reference scaling procedure. X2 demonstrated in vivo BE, while X1 and Y1 failed to show BE due to the lower boundary of the 90% confidence interval for C max being outside the acceptance limits. Average plasma profiles were deconvoluted by the Loo-Riegelman method to obtain the oral fractions absorbed (f a). Fractions dissolved (f diss) were obtained in several conditions in USP II and USP IV apparatus, and later, the results were compared in order to find the most biopredictive model, calculating the f 2 similarity factor. The apparatus and conditions showing the same rank order than in vivo data were selected for further refinement of conditions. A Levy plot was constructed to estimate the time scaling factor and to make both processes, dissolution and absorption, superimposable. The in vitro dissolution experiment that reflected more accurately the in vivo behavior of the different formulations of telmisartan employed the USP IV dissolution apparatus and a dissolution environment with a flow rate of 8 mL/min and a three-step pH change, from 1.2 to 4.5 and 6.8, with a 0.05% of Tween 80. Thus, these conditions gave rise to a biopredictive dissolution test. This new model is able to predict the formulation differences in dissolution that were previously observed in vivo, which could be used as a risk-analysis tool for formulation selection in future bioequivalence trials.
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