71 research outputs found
La tasa de retorno energético desde un enfoque agroecológico y su aplicación a la evolución de la agricultura española, 1900-2010
Los análisis energéticos aplicados a la agricultura deben expresar algo más que el "coste energético" de la biomasa neta producida en beneficio de la sociedad. Deben, además, informar sobre los cambios estructurales y funcionales en los agroecosistemas que puedan afectar al mantenimiento de los servicios ambientales que éstos proporcionan. Con este fin, hemos desarrollado una propuesta metodológica que propone Tasas de Retorno Energético (TRE) con enfoque agroecológico, que complementan las TRE con enfoque económico existentes. Esta propuesta se ha aplicado a la agricultura española en tres momentos clave:
la agricultura orgánica equilibrada (año 1900), el comienzo de la industrialización de la agricultura (1960) y la plena industrialización agraria (2008). Los resultados muestran la pérdida de eficiencia energética debido al proceso de industrialización y cuestionan que la intensificación haya supuesto beneficios ambientales a causa del abandono parcial de las tierras agrarias.Energy analyses applied to agriculture should express something more than the “energy cost” of the net biomass produced for the benefit of society. They should also provide information about structural and functional changes in the agro-ecosystem which might affect the maintenance of the ecosystem services which the agro-ecosystem provides.
With this aim, a methodological proposal has been developed to add agro-ecological Energy Return on Investment (EROIs) to the existing economic EROIs. This proposal has been applied to Spanish agriculture at three key moments: one of balanced organic agriculture (1900), at the beginning of agriculture industrialization (1960) and full agricultural industrialization (2008). The results show the energy efficiency loss caused by industrialization and belie that intensification has caused environmental benefits due to the partial abandonment of agricultural land.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale
La tasa de retorno energético desde un enfoque agroecológico y su aplicación a la evolución de la agricultura española, 1900-2010
Los análisis energéticos aplicados a la agricultura deben expresar algo más que el "coste energético" de la biomasa neta producida en beneficio de la sociedad. Deben, además, informar sobre los cambios estructurales y funcionales en los agroecosistemas que puedan afectar al mantenimiento de los servicios ambientales que éstos proporcionan. Con este fin, hemos desarrollado una propuesta metodológica que propone Tasas de Retorno Energético (TRE) con enfoque agroecológico, que complementan las TRE con enfoque económico existentes. Esta propuesta se ha aplicado a la agricultura española en tres momentos clave:
la agricultura orgánica equilibrada (año 1900), el comienzo de la industrialización de la agricultura (1960) y la plena industrialización agraria (2008). Los resultados muestran la pérdida de eficiencia energética debido al proceso de industrialización y cuestionan que la intensificación haya supuesto beneficios ambientales a causa del abandono parcial de las tierras agrarias.Energy analyses applied to agriculture should express something more than the “energy cost” of the net biomass produced for the benefit of society. They should also provide information about structural and functional changes in the agro-ecosystem which might affect the maintenance of the ecosystem services which the agro-ecosystem provides.
With this aim, a methodological proposal has been developed to add agro-ecological Energy Return on Investment (EROIs) to the existing economic EROIs. This proposal has been applied to Spanish agriculture at three key moments: one of balanced organic agriculture (1900), at the beginning of agriculture industrialization (1960) and full agricultural industrialization (2008). The results show the energy efficiency loss caused by industrialization and belie that intensification has caused environmental benefits due to the partial abandonment of agricultural land.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale
La tasa de retorno energético desde un enfoque agroecológico y su aplicación a la evolución de la agricultura española, 1900-2010
Los análisis energéticos aplicados a la agricultura deben expresar algo más que el "coste energético" de la biomasa neta producida en beneficio de la sociedad. Deben, además, informar sobre los cambios estructurales y funcionales en los agroecosistemas que puedan afectar al mantenimiento de los servicios ambientales que éstos proporcionan. Con este fin, hemos desarrollado una propuesta metodológica que propone Tasas de Retorno Energético (TRE) con enfoque agroecológico, que complementan las TRE con enfoque económico existentes. Esta propuesta se ha aplicado a la agricultura española en tres momentos clave:
la agricultura orgánica equilibrada (año 1900), el comienzo de la industrialización de la agricultura (1960) y la plena industrialización agraria (2008). Los resultados muestran la pérdida de eficiencia energética debido al proceso de industrialización y cuestionan que la intensificación haya supuesto beneficios ambientales a causa del abandono parcial de las tierras agrarias.Energy analyses applied to agriculture should express something more than the “energy cost” of the net biomass produced for the benefit of society. They should also provide information about structural and functional changes in the agro-ecosystem which might affect the maintenance of the ecosystem services which the agro-ecosystem provides.
With this aim, a methodological proposal has been developed to add agro-ecological Energy Return on Investment (EROIs) to the existing economic EROIs. This proposal has been applied to Spanish agriculture at three key moments: one of balanced organic agriculture (1900), at the beginning of agriculture industrialization (1960) and full agricultural industrialization (2008). The results show the energy efficiency loss caused by industrialization and belie that intensification has caused environmental benefits due to the partial abandonment of agricultural land.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale
Morphological Analysis of Major Segments of Coronary Artery Occlusion: Importance in Myocardial Revascularization Surgery
Revascularization surgery should ensure morphological similarity between the coronary artery and the graft. This is an important factor for its duration and permeability. The aim of this study was to analyze the morphological characteristics and morphometrics of the coronary artery segments with greater occlusion. This was an observational, cross-sectional descriptive study that
consisted of two phases. A macroscopic phase in which 11 cadaveric hearts were extracted and coronary dominance and length of the anterior interventricular artery (AIA), the right coronary artery (RCA) and the circumflex artery (CXA) were determined. In the microscopic phase a total of 77 segments of these arteries were obtained and the luminal diameter, wall thickness, and amount of elastic fibers and the presence and size of the atheroma were determined. Right coronary dominance was the most frequent. Total vessel length was 15.65±1.17 cm for the AIA, 12.67±2.02 cm for the RCA and 8.79±2.5 cm for the CXA. Diameters ranged from 2.3 mm in the proximal segments and between 1.1 mm to 1.8 mm in the distal segments. Wall thickness in the proximal segments was between 354 µm and 396 µm and in the distal segments it ranged from 120 µm to 305 µm. The amount of elastic fibers showed that they were muscular arteries. Atheromas were present in 35% in the CXA, and in 32.5% in the AIA and the RCA. The largest ones were found in the proximal segments. This study examined the morphology and morphometry of the segments of the coronary arteries that are more frequently occluded. It provides information on the most significant parameters to be considered for election of the vascular graft in myocardial revascularization surgery
Agroecosystem energy transitions in the old and new worlds: trajectories and determinants at the regional scale
Energy efficiency in biomass production is a major challenge for a future transition to sustainable food and energy provision. This study uses methodologically consistent data on agroecosystem energy flows and different metrics of energetic efficiency from seven regional case studies in North America (USA and Canada) and Europe (Spain and Austria) to investigate energy transitions in Western agroecosystems from the late nineteenth to the late twentieth centuries. We quantify indicators such as external final energy return on investment (EFEROI, i.e., final produce per unit of external energy input), internal final EROI (IFEROI, final produce per unit of biomass reused locally), and final EROI (FEROI, final produce per unit of total inputs consumed). The transition is characterized by increasing final produce accompanied by increasing external energy inputs and stable local biomass reused. External inputs did not replace internal biomass reinvestments, but added to them. The results were declining EFEROI, stable or increasing IFEROI, and diverging trends in FEROI. The factors shaping agroecosystem energy profiles changed in the course of the transition: Under advanced organic and frontier agriculture of the late nineteenth and early twentieth centuries, population density and biogeographic conditions explained both agroecosystem productivity and energy inputs. In industrialized agroecosystems, biogeographic conditions and specific socio-economic factors influenced trends towards increased agroecosystem specialization. The share of livestock products in a region's final produce was the most important factor determining energy returns on investment
Yeasts associated with the production of distilled alcoholic beverages
Distilled alcoholic beverages are produced firstly by fermenting sugars emanating from cereal starches (in the case of whiskies), sucrose-rich plants (in the case of rums), fructooligosaccharide-rich plants (in the case of tequila) or from fruits (in the case of brandies). Traditionally, such fermentations were conducted in a spontaneous fashion, relying on indigenous microbiota, including wild yeasts. In modern practices, selected strains of Saccharomyces cerevisiae are employed to produce high levels of ethanol together with numerous secondary metabolites (eg. higher alcohols, esters, carbonyls etc.) which greatly influence the final flavour and aroma characteristics of spirits following distillation of the fermented wash. Therefore, distillers, like winemakers, must carefully choose their yeast strain which will be very important in providing the alcohol content and the sensory profiles of spirit beverages. This Chapter discusses yeast and fermentation aspects associated with the production of selected distilled spirits and highlights similarities and differences with the production of wine
Molecules with ALMA at Planet-forming Scales (MAPS). IV. Emission surfaces and vertical distribution of molecules
Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1).The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a unique opportunity to study the vertical distribution of gas, chemistry, and temperature in the protoplanetary disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. By using the asymmetry of molecular line emission relative to the disk major axis, we infer the emission height (z) above the midplane as a function of radius (r). Using this method, we measure emitting surfaces for a suite of CO isotopologues, HCN, and C2H. We find that 12CO emission traces the most elevated regions with z/r ∼< 0.3 , while emission from the less abundant 13CO and C18O probes deeper into the disk at altitudes of z/r ~< 0.2 . C2H and HCN have lower opacities and signal-to-noise ratios, making surface fitting more difficult, and could only be reliably constrained in AS 209, HD 163296, and MWC 480, with z/r ~< 0.1 , i.e., relatively close to the planet-forming midplanes. We determine peak brightness temperatures of the optically thick CO isotopologues and use these to trace 2D disk temperature structures. Several CO temperature profiles and emission surfaces show dips in temperature or vertical height, some of which are associated with gaps and rings in line and/or continuum emission. These substructures may be due to local changes in CO column density, gas surface density, or gas temperatures, and detailed thermochemical models are necessary to better constrain their origins and relate the chemical compositions of elevated disk layers with those of planet-forming material in disk midplanes. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe
Molecules with ALMA at planet-forming scales (MAPS). IV. Emission surfaces and vertical distribution of molecules
The Molecules with ALMA at Planet-forming Scales (MAPS) Large Program provides a unique opportunity to study the vertical distribution of gas, chemistry, and temperature in the protoplanetary disks around IM Lup, GM Aur, AS 209, HD 163296, and MWC 480. By using the asymmetry of molecular line emission relative to the disk major axis, we infer the emission height (z) above the midplane as a function of radius (r). Using this method, we measure emitting surfaces for a suite of CO isotopologues, HCN, and C2H. We find that 12CO emission traces the most elevated regions with z/r > 0.3, while emission from the less abundant 13CO and C18O probes deeper into the disk at altitudes of z/r ≲ 0.2. C2H and HCN have lower opacities and signal-to-noise ratios, making surface fitting more difficult, and could only be reliably constrained in AS 209, HD 163296, and MWC 480, with z/r ≲ 0.1, i.e., relatively close to the planet-forming midplanes. We determine peak brightness temperatures of the optically thick CO isotopologues and use these to trace 2D disk temperature structures. Several CO temperature profiles and emission surfaces show dips in temperature or vertical height, some of which are associated with gaps and rings in line and/or continuum emission. These substructures may be due to local changes in CO column density, gas surface density, or gas temperatures, and detailed thermochemical models are necessary to better constrain their origins and relate the chemical compositions of elevated disk layers with those of planet-forming material in disk midplanes. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement. © 2021. The American Astronomical Society. All rights reserved.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Revisiting individualization: The transitions to marriage and motherhood in Chile
The life course of Chilean women has experienced profound transformations in the past decades. It has been argued that transitions to marriage and motherhood are being postponed as they are experienced by women at an older age and are becoming events that characterize an increasingly smaller part of the female population. These changes have been often interpreted as part of a process of individualization that would have had reconfigured the cultural norms and social practices regarding gender roles and family formation in Chilean society. Nevertheless, the prevalence and diversification of the practices and norms that shape the transitions to marriage and motherhood at an empirical level remain unexplored. This paper aims to assess the individualization of the life course of women in Chile by empirically analyzing the destandardization of the practices and norms that shape the transitions to marriage and motherhood. By analyzing data from Encuesta Nacional Bicentenario Universidad Católica – Adimark (2009), it demonstrates that changes in the prevalence of the transitions to marriage and motherhood and the diversification of the practices and norms that shape their timing are ambivalent regarding destandardization. These results suggest that the life course of women in Chile is becoming individualized to some extent, but that this trend of cultural and social change is not consistent and uniform, but rather partial and fragmented, nonlinear, and significantly conditioned by the social structure
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