Energy and carbon footprints of biofuel systems using banana and plantain waste

Waste that accumulates in Musa production systems (up to 40% of total fruit biomass) has a great potential to be processed into bioethanol due to high sugar contents of fruits, and can open new energy sources and markets for small-scale banana and plantain producers. However, the economical and ecological sustainability of biofuel systems strongly depends on how they are produced. The present study aimed to analyse energy and carbon footprints of Musa bioethanol production systems using a life cycle approach. The study compares three case studies differing in management practices, which are (1) a coffee producer's cooperative in Costa Rica using Musa as shade trees, (2) organic banana producers from Ecuador, and (3) conventional banana producers from Ecuador. The best net-energy balance (19.3 MJ L-1) was obtained for the case study from Costa Rica, closely followed by the organic producers from Ecuador (17.1 MJ L-1), which are Musa production systems operating with low external inputs. The net-energy balance for the conventional banana farms in Ecuador was significantly lower (7.2 MJ L?1), mainly due to the high amount of energy required for producing external inputs such as mineral fertilisers and pesticides. All three case studies yielded avoided carbon emissions (C emissions that are avoided when biofuels are used instead of petroleum based fuel), with the best value obtained for the Costa Rican case study (0.48 kg C L?1), followed by the organic (0.44 kg L?1) and the conventional (0.34 kg L?1) banana producers from Ecuador. 40-100% of gasoline consumption of farm households could be replaced by bioethanol, thereby saving C emissions in the range of 226-1038 kg yr-1. The study clearly showed the need to conduct feasibility studies that consider economic as well as ecological aspects. Biofuel systems should aim at having more favourable energy and carbon balances than fossil fuels, which will open opportunities for carbon credits and new markets. (Résumé d'auteur

Pleistocene-Holocene P. nigra traces on tufa archives in the Northern Meseta of the Iberian Peninsula

Molds preserved on travertines constitute exceptional species-informative material to reconstruct past vegetation. These are common on the High Ebro region. Here, the fluvial system erosion and karstification of the Mesozoic limestone since the Late Tertiary, origins extensive travertine complexes like the one studied in Tubilla del Agua (Burgos). In this site, three different travertine complexes are observed. The older one is represented by two disconnected edifices incised by the Valoria river. The age of this structure is established between > 300,000 and 240,000 yr BP, as from the U/Th dating on its base and top. The subsequent incision lasted until at least 90,000 yr BP, when another edifice erected upstream on the older one. The second travertine group comprises three platforms aged 60,000 yr BP the lower one, and 18,000 yr BP the middle one. The third travertine group is a lake-barrier complex 12,000 yr BP old, on which Tubilla del Agua was built, and a stratified travertine body that covers the valley bottom 10,000 to 2700 cal yr BP old. Some of the ages of the oldest travertines, and the most modern ones, coincide with the principal travertine formation cycles described by Durán (1996) for Spain. The matrix of precipitated calcium carbonate of all these complexes are rich in plant remain molds (mosses, stems, leaves, cones) of the surrounding flora. Pinus nigra Arnold cone molds have been localized and identified by comparative morphology studies. These remains are of high valuable information about the Pleistocene and Holocene presence of this taxon, in a site where no natural presence can be found today. This work was funded by project CGL2008-06005

Determinación de la capacidad parasitaria de la microbiota fúngica y de sus extractos acuosos en las semillas de cardo (Cynara cardunculus L.)

El presente estudio evalúa el efecto que 6 diferentes géneros hongos aislados a partir de semillas de 54 diferentes cultivares de cardo y sus extractos acuosos tienen sobre la germinación y nascencia de las semillas. Se han realizado pruebas de patogenicidad con dos aislados de cada uno de los seis géneros de mayor frecuencia del inventario (Aspergillus, Penicillium, Fusarium, Rhizopus, Cladosporium y Alternaria), así como de los extractos producidos tras 3, 7 y 11 días de incubación de los micetos. Los resultados de las inoculaciones con los micetos muestran efectos negativos sobre los porcentajes de germinación, con reducciones en la germinación que fueron máximas tras las inoculaciones con Rhizopus stolonifer (29% de disminución) y Fusarium verticillioides (23%). Los porcentajes de emergencia disminuyen tras duplicar la concentración del inóculo, aumentando además drásticamente el número de plántulas dañadas sobre el total de las emergidas. En el significativo caso de la inoculación con Cladosporium la duplicación del inóculo disminuyó la germinación hasta en un 31% respecto al testigo. Las plántulas emergidas tras las inoculaciones con los extractos obtenidos a partir de cultivos líquidos de los hongos ensayados presentaban los mismos síntomas de atrofias y daños sobre raíz y coleóptilo que los descritos para cada hongo. Los extractos acuosos de los géneros estudiados disminuyen también la germinación. Los resultados nos muestran la diferente capacidad parasitaria de cada una de las especies estudiadas apreciándose además diferencias según los diferentes periodos de agitación de los hongos y permiten asegurar que la producción de toxinas está regulada por el hongo, y que no aumenta linealmente con el crecimiento miceliar

Low X-ray Luminosity Galaxy Clusters. III: Weak Lensing Mass Determination at 0.18 << z << 0.70

This is the third of a series of papers of low X-ray luminosity galaxy clusters. In this work we present the weak lensing analysis of eight clusters, based on observations obtained with the Gemini Multi-Object Spectrograph in the $g'$, $r'$ and $i'$ passbands. For this purpose, we have developed a pipeline for the lensing analysis of ground-based images and we have performed tests applied to simulated data. We have determined the masses of seven galaxy clusters, six of them measured for the first time. For the four clusters with availably spectroscopic data, we find a general agreement between the velocity dispersions obtained via weak lensing assuming a Singular Isothermal Sphere profile, and those obtained from the redshift distribution of member galaxies. The correlation between our weak lensing mass determinations and the X-ray luminosities are suitably fitted by other observations of the $M-L_{X}$ relation and models

Near-Infrared and Star-forming properties of Local Luminous Infrared Galaxies

We use HST NICMOS continuum and Pa-alpha observations to study the near-infrared and star-formation properties of a representative sample of 30 local (d ~ 35-75Mpc) luminous infrared galaxies (LIRGs, infrared 8-1000um luminosities of L_IR=11-11.9[Lsun]). The data provide spatial resolutions of 25-50pc and cover the central ~3.3-7.1kpc regions of these galaxies. About half of the LIRGs show compact (~1-2kpc) Pa-alpha emission with a high surface brightness in the form of nuclear emission, rings, and mini-spirals. The rest of the sample show Pa-alpha emission along the disk and the spiral arms extending over scales of 3-7kpc and larger. About half of the sample contains HII regions with H-alpha luminosities significantly higher than those observed in normal galaxies. There is a linear empirical relationship between the mid-IR 24um and hydrogen recombination (extinction-corrected Pa-alpha) luminosity for these LIRGs, and the HII regions in the central part of M51. This relation holds over more than four decades in luminosity suggesting that the mid-IR emission is a good tracer of the star formation rate (SFR). Analogous to the widely used relation between the SFR and total IR luminosity of Kennicutt (1998), we derive an empirical calibration of the SFR in terms of the monochromatic 24um luminosity that can be used for luminous, dusty galaxies.Comment: Accepted for publication in ApJ. Contact first author for high qualitity version of figure

Differences between CO- and calcium triplet-derived velocity dispersions in spiral galaxies: evidence for central star formation?

We examine the stellar velocity dispersions (sigma) of a sample of 48 galaxies, 35 of which are spirals, from the Palomar nearby galaxy survey. It is known that for ultra-luminous infrared galaxies (ULIRGs) and merger remnants thesigma derived from the near-infrared CO band-heads is smaller than that measured from optical lines, while no discrepancy between these measurements is found for early-type galaxies. No such studies are available for spiral galaxies - the subject of this paper. We used cross-dispersed spectroscopic data obtained with the Gemini Near-Infrared Spectrograph (GNIRS), with spectral coverage from 0.85 to 2.5um, to obtain sigma measurements from the 2.29 $\mu$m CO band-heads (sigma_{CO}), and the 0.85 um calcium triplet (sigma_{CaT}). For the spiral galaxies in the sample, we found that sigma_{CO} is smaller than sigma_{CaT}, with a mean fractional difference of 14.3%. The best fit to the data is given by sigma_{opt} = (46.0+/-18.1) + (0.85+/-0.12)sigma_{CO}. This "sigma discrepancy" may be related to the presence of warm dust, as suggested by a slight correlation between the discrepancy and the infrared luminosity. This is consistent with studies that have found no sigma-discrepancy in dust-poor early-type galaxies, and a much larger discrepancy in dusty merger remnants and ULIRGs. That sigma_{CO}$ is lower than sigma_{opt} may also indicate the presence of a dynamically cold stellar population component. This would agree with the spatial correspondence between low sigma_{CO} and young/intermediate-age stellar populations that has been observed in spatially-resolved spectroscopy of a handful of galaxies.Comment: Published in MNRAS, 446, 282

Calculation of Response matrix of a BSS with 6LiI scintillator

The response matrix of a Bonner sphere spectrometer was calculated using MCNP 4C and MCNPX 2.4.0 codes. As thermal neutron detector a 0.4 cm £; 0.4 cm 6LiI which is located at the center of a set of polyethylene spheres. The response was calculated for 0, 2, 3, 5, 8, 10, and 12 inches-diameter polyethylene spheres for neutrons whose energy goes from 2.50E(-8) to 100 MeV. The response matrix was calculated for 23 neutron energies, the response functions were energy-interpolated to 51 neutron energies and were compared with a matrix response reported in the literature, in this comparison both response matrices are in agreement. The main differences were found in the bare detector and are attributed to the irradiation conditions and cross sections, for the other detectors the differences are due to the cross sections libraries

Estudio de caso de sindrome neurologico asociado a astrocitoma

El astrocitoma es una neoplasia primaria del sistema nervioso central que se puede presentar en los animales; de las especies domésticas se ha observado con mayor frecuencia en los perros, de éstos, la edad y la raza son factores que influyen en su presentación, en estudios anteriores han descrito que el astrocitoma es una neoplasia que se presenta con mayor frecuencia en perros de características braquicefalicas, además que su malignidad depende de la localización y del carácter invasivo que presenta. Se presenta el estudio de caso de un paciente canino Labrador, macho de 6 años de edad, con un cuadro clínico neurológico de origen compresivo y obstructivo, derivado de una neoplasia intracraneala. Se documentó el caso a través del método clínico, basado en la historia clínica y la evolución del caso, imagenología e histopatología. Lo observado a través de las placas, correspondieron a una masa tumoral en la región ventral correspondiente al diencéfalo cuya localización se refiere adyacente a la estructura hipotalámica con efecto obstructivo y compresivo compatible con un astrocitoma; al estudio anatomopatológico se observo un tumor localizado adyacente al hipotálamo del cerebro; histológicamente el tumor se identifico como un astrocitoma gemistocítico

El Hayedo de Montejo, mucho más que hayas

El Hayedo de Montejo, uno de los bosques más emblemáticos de la Comunidad de Madrid, es también uno de los mejor conocidos y más estudiados gracias a un convenio de colaboración entre la Comunidad de Madrid y la Escuela de Montes de la Universidad Politécnica de Madrid (UPM). Seguimiento del clima, inventarios forestales, estudios genéticos o ecofisiológicos y procesos de dispersión son algunos de los trabajos que vienen desarrollándose desde hace más de 17 años. Gracias a ellos descubrimos que El Hayedo de Montejo es mucho más que un bosque de hayas