Paying the forest for electricity: A modelling framework to market forest conservation as payment for ecosystem services benefiting hydropower generation

Published in PESC Special issue: Payments for ecosystem services in conservation: performance and prospectsThe operation and longevity of hydropower dams are often negatively impacted by sedimentation. Forest conservation can reduce soil erosion, and therefore efforts to maintain upstream forest cover within a watershed contribute to the economic life span of a hydropower facility. The cost of forest conservation can be viewed as an investment in hydropower and be financed via a payment for ecosystem services (PES) scheme. A novel modelling framework is used to estimate payments for forest conservation consisting of: (1) land-use change projection; (2)watershed erosion modelling; (3) reservoir sedimentation estimation; (4) power generation loss calculation; and (5) PES scheme design. The framework was applied to a proposed dam in Cambodia (Pursat 1). The estimated net present value of forest conservation was US$4.7 million when using average annual climate values over 100 years, or US$ 6.4 million when considering droughts every eight years. This can be remunerated with annual payments ofUS$4.26ha-1 or US$ 5.78ha-1, respectively, covering forest protection costs estimated at US$ 0.9 ha-1 yr-1. The application of this type of PES represents a rational option that allows for conservation and development of hydropower watersheds susceptible to erosion and sedimentation

Paying the forest for electricity: A modelling framework to market forest conservation as payment for ecosystem services benefiting hydropower generation

Published in PESC Special issue: Payments for ecosystem services in conservation: performance and prospectsThe operation and longevity of hydropower dams are often negatively impacted by sedimentation. Forest conservation can reduce soil erosion, and therefore efforts to maintain upstream forest cover within a watershed contribute to the economic life span of a hydropower facility. The cost of forest conservation can be viewed as an investment in hydropower and be financed via a payment for ecosystem services (PES) scheme. A novel modelling framework is used to estimate payments for forest conservation consisting of: (1) land-use change projection; (2)watershed erosion modelling; (3) reservoir sedimentation estimation; (4) power generation loss calculation; and (5) PES scheme design. The framework was applied to a proposed dam in Cambodia (Pursat 1). The estimated net present value of forest conservation was US$4.7 million when using average annual climate values over 100 years, or US$ 6.4 million when considering droughts every eight years. This can be remunerated with annual payments ofUS$4.26ha-1 or US$ 5.78ha-1, respectively, covering forest protection costs estimated at US$ 0.9 ha-1 yr-1. The application of this type of PES represents a rational option that allows for conservation and development of hydropower watersheds susceptible to erosion and sedimentation

Pulsed electric fields as a green technology for the extraction of bioactive compounds from thinned peach by-products

Thinned fruits are agricultural by-products which nowadays have few economic or environmental benefits. However, previous studies have revealed that these immature fruits have a large amount of antioxidant compounds. The aim of this study was to evaluate whether pulsed electric fields (PEF) might be a suitable green technology for enhancing the extraction of phenols, flavonoids and antioxidant compounds from fresh thinned peaches, thus reducing the use of methanol. Moreover, response surface methodology has been used to determine the optimal PEF treatment conditions, observing that the solvent is the main factor. The highest amounts of bioactive compounds were extracted using 80% methanol and no PEF. Methanol combined with PEF produced a negative effect on the extraction yield. However, the use of water as a solvent increased the amount of total bioactive compounds and individual phenols (chlorogenic acid, coumaric acid and neochlorogenic acid). Thus, PEF-assisted extraction of bioactive compounds from thinned peach fruits using water as a solvent is an alternative to conventional extraction methods which require dried products, large amounts of organic solvents and long extraction times

One hundred years of solitude, accumulation and violence: A comparative historical analysis of the Sierra Nevada of Santa Marta Valley

This is an analysis of two moments in the Colombian history within a century of difference, where isolation, accumulation and violence interact in a region brought into the worlds’ imaginary by the Colombian novelist Gabriel García Márquez in One Hundred years of Solitude. A valley between four natural borderlines: the Sierra Nevada of Santa Marta, the Perijá hills, the Central and East ‘Cordilleras’ -mountain range- and the Magdalena River in the departments of Cesar and Magdalena (Colombia) part of what was called the department of ‘Magdalena Grande’ was blessed – or perhaps coursed – with wealth in natural resources; plenty of water streams, a unique biodiversity, cultural affluence and immense reserves of one of the purest steam coals. This paper attempts to draw a picture of the superimposed and persistent power structures that apparently facilitate the accumulative processes and imbalances within one century of difference, making use of violence as means to maintain equilibrium. Environment is changed trough politicized violent inflictions over society and nature. The resultant scars are the ones inflicted on a collective memory, as this valley is and will always be recalled by the poetic truth of the narrative of Gabriel García Marquez who recreated this mythic environment as ‘Macondo’. He remembers his own story of early childhood that here serves as an excuse to analyze a region that is again being bled by accumulation

Discovery of the first B[e] supergiants in M 31

B[e] supergiants (B[e]SGs) are transitional objects in the post-main sequence evolution of massive stars. The small number of B[e]SGs known so far in the Galaxy and the Magellanic Clouds indicates that this evolutionary phase is short. Nevertheless, the strong aspherical mass loss occurring during this phase, which leads to the formation of rings or disk-like structures, and the similarity to possible progenitors of SN1987 A emphasize the importance of B[e]SGs for the dynamics of the interstellar medium as well as stellar and galactic chemical evolution. The number of objects and their mass-loss behavior at different metallicities are essential ingredients for accurate predictions from stellar and galactic evolution calculations. However, B[e]SGs are not easily identified, as they share many characteristics with luminous blue variables (LBVs) in their quiescent (hot) phase. We present medium-resolution near-infrared K-band spectra for four stars in M 31, which have been assigned a hot LBV (candidate) status. Applying diagnostics that were recently developed to distinguish B[e]SGs from hot LBVs, we classify two of the objects as bonafide LBVs; one of them currently in outburst. In addition, we firmly classify the two stars 2MASS J00441709+4119273 and 2MASS J00452257+4150346 as the first B[e]SGs in M 31 based on strong CO band emission detected in their spectra, and infrared colors typical for this class of stars.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

¡De sexo sí se habla! Talleres de educación sexual y género

Este trabajo reflexiona acerca de las experiencias de un Proyecto de Extensión de la Universidad Nacional de Quilmes que realiza Talleres de sexualidad y género en escuelas secundarias, en el marco de la Ley 26150 y el Programa Nacional de Educación Sexual Integral. Trabajamos con alumnos de 14/17 años, de escuelas secundarias públicas de Quilmes, Berazategui y Florencio Varela. Los 10 coordinadores de los talleres somos docentes, administrativos y ex alumnos de UNQ, licenciados en psicopedagogía, psicología, educación y economía. Los contenidos fundamentales que trabajamos en los talleres son cuatro: género, sexualidad, salud reproductiva y derechos reproductivos y de género. El dispositivo involucra la participación de distintos actores de la escuela, directivos, docentes y equipo o gabinete. Se realizan tres encuentros con los alumnos, donde se presentan diferentes materiales audiovisuales y escritos, para ser analizados y elaborados en subgrupos. Utilizamos la metodología de aula taller, que favorece la participación, la expresión de las ideas previas de los adolescentes, su reflexión, comparación y crítica. Las respuestas que da cada grupo son leídas y comentadas en plenario. Los estudiantes se formulan preguntas y dudas sobre los distintos temas, y debaten intensamente. Para el último encuentro los grupos deben preparar un material con formato de lamina, afiche, historieta, video, canción, o logo. Este material debe ser ilustrativo de uno de los temas que abordamos en los talleres, y está destinado a sus compañeros del curso, de la escuela o de otras escuelas similares. Los alumnos obtienen la información sobre los contenidos del taller desde el Blog del Proyecto, y pueden contactarse con nosotros a través de Facebook. Todos los materiales presentados compiten en un concurso anual convocado por la Secretaría de Extensión de UNQ junto a la Jefatura Regional IV de Escuelas. Las producciones de los alumnos revelan cómo ellos construyen sus realidades subjetivas y colectivas de género. Se presenta una fuerte predominancia de los estereotipos de género tradicionales, que reproducen la binariedad heteronormativa, al mismo tiempo que hay tolerancia por la diversidad de género. En el aula aparece agresividad y violencia verbal, incluso física, lo cual trabajamos especialmente. La situación del taller no es sencilla, hay interrupciones, indiferencia, desafíos hacia la coordinación. La observación de estas expresiones y comportamientos nos llevó a modificar progresivamente el dispositivo y los contenidos de los talleres. A pesar de estas dificultades los estudiantes participan de manera activa y producen trabajos que revelan su interés y compromiso

El aclareo en fruto: ¿una nueva fuente de compuestos funcionales?

Estudio del contenido en compuestos antioxidantes de los frutos preocedentes del aclareo del melocotón, nectarina y paraguay

Testing postcombustion CO2 capture with CaO in a 1.7 MWt pilot facility

AbstractCalcium looping, CaL, is a new and rapidly developing technology that makes use of CaO as a high temperature regenerable sorbent of CO2. Previous theoretical and lab scale studies have shown that this technology could lead to a substantial reduction in the cost of CO2 capture and energy penalties because heat can be effectively recovered from this high temperature solid looping system. We report in this paper on the first results from a pilot plant designed to demonstrate the viability of postcombustion capture of CO2 using CaL under conditions comparable to those expected in a large scale plant. The pilot includes two interconnected circulating fluidized bed reactors of 15 m height: a CO2 absorber (carbonator) able to treat up to 2400kg/h (equivalent to about 1.7 MWth), and an oxy-fired CFB calciner with a firing power between 1-3 MWth. CO2 capture efficiencies over 90% have been experimentally observed, including continuous operation with highly cycled solids in the system (i.e. with modest CO2 carrying capacities). SO2 capture is shown to be extremely high, with concentrations of SO2 well below 10 ppmv at the exit of the carbonator. Closure of carbon and sulfur balances is satisfactory. These results should be valuable base for model validation and scaling up purposes in future stages of the EU FP7 “CaOling” project, under which this investigation has been carried out

Mechanical Identities of RNA and DNA Double Helices Unveiled at the Single-Molecule Level

[EN] Double-stranded (ds) RNA is the genetic material of a variety of viruses and has been recently recognized as a relevant molecule in cells for its regulatory role. Despite that the elastic response of dsDNA has been thoroughly characterized in recent years in single-molecule stretching experiments, an equivalent study with dsRNA is still lacking. Here, we have engineered long dsRNA molecules for their individual characterization contrasting information with dsDNA molecules of the same sequence. It is known that dsRNA is an A-form molecule unlike dsDNA, which exhibits B-form in physiological conditions. These structural types are distinguished at the single-molecule level with atomic force microscopy (AFM) and are the basis to understand their different elastic response. Force¿extension curves of dsRNA with optical and magnetic tweezers manifest two main regimes of elasticity, an entropic regime whose end is marked by the A-form contour- length and an intrinsic regime that ends in a low-cooperative overstretching transition in which the molecule extends to 1.7 times its A-form contour-length. DsRNA does not switch between the A and B conformations in the presence of force. Finally, dsRNA presents both a lower stretch modulus and overstretching transition force than dsDNA, whereas the electrostatic and intrinsic contributions to the persistence length are larger.This work was supported by grants from the Spanish Ministry of Science and Innovation (BFU2011-29038 and BFU2010-15703) and the Comunidad de Madrid (S2009/MAT/1507). IRA.-G. acknowledges a Ramon y Cajal contract from the Spanish Ministry of Science and Innovation (RYC-2007-01765). Work in the F.M.-H. laboratory was supported by a Starting Grant from the European Research Council (no. 206117) and a grant from the Spanish Ministry of Science and Innovation (FIS2011-24638). We thank M. S. Dillingham for kindly providing the pSP73-JY0 plasmid, M. Menendez for access to a spectropolarimeter, A. Monserrate for polylysine-AFM control experiments, and B. Ibarra for fruitful discussions.Herrero-Galán, E.; Fuentes-Perez. M.E.; Carrasco, C.; Valpuesta, J.; Carrascosa, J.; Moreno-Herrero, F.; Arias-Gonzalez, JR. (2013). Mechanical Identities of RNA and DNA Double Helices Unveiled at the Single-Molecule Level. Journal of the American Chemical Society. 135(1):122-131. https://doi.org/10.1021/ja3054755S122131135