Evaluation of the Impact of Climate Change on Runoff Generation in an Andean Glacier Watershed

Excluding Antarctica and Greenland, 3.8% of the world’s glacier area is concentrated in Chile. The country has been strongly affected by the mega drought, which affects the south-central area and has produced an increase in dependence on water resources from snow and glacier melting in dry periods. Recent climate change has led to an elevation of the zero-degree isotherm, a decrease in solid-state precipitation amounts and an accelerated loss of glacier and snow storage in the Chilean Andes. This situation calls for a better understanding of future water discharge in Andean headwater catchments in order to improve water resources management in glacier-fed populated areas. The present study uses hydrological modeling to characterize the hydrological processes occurring in a glacio-nival watershed of the central Andes and to examine the impact of different climate change scenarios on discharge. The study site is the upper sub-watershed of the Tinguiririca River (area: 141 km2), of which nearly 20% is covered by Universidad Glacier. The semi-distributed Snowmelt Runoff Model + Glacier (SRM+G) was forced with local meteorological data to simulate catchment runoff. The model was calibrated on even years and validated on odd years during the 2008–2014 period and found to correctly reproduce daily runoff. The model was then forced with downscaled ensemble projected precipitation and temperature series under the RCP 4.5 and RCP 8.5 scenarios, and the glacier adjusted using a volume-area scaling relationship. The results obtained for 2050 indicate a decrease in mean annual discharge (MAD) of 18.1% for the lowest emission scenario and 43.3% for the most pessimistic emission scenario, while for 2100 the MAD decreases by 31.4 and 54.2%, respectively, for each emission scenario. Results show that decreasing precipitation lead to reduced rainfall and snowmelt contributions to discharge. Glacier melt thus partly buffers the drying climate trend, but our results show that the peak water occurs near 2040, after which glacier depletion leads to reducing discharge, threatening the long-term water resource availability in this region

Phenolic profile and physicochemical characterization of quince (Cydonia oblonga Mill) fruits at different maturity index

The ripening of fruits is a determinant factor on the composition of phytochemical compounds such as phenolic compounds. In this study the phenolic profile of quince fruits was determined as a function of its maturity index. Based on the total soluble solids (TSS) and the acidity (TA) of the fruits, four maturity indexes were established (12.55, 14.56, 21.86 and 24.77), using the ratio of TSS/TA. The phenolic profile of quince fruits with different maturity indexes were obtained by a reversed-phase HPLC-DAD and HPLC-DAD/MS. A PCA loading plot was generated to explain the relationship between physicochemical parameters and the phenolic compounds. The phenolic compounds identified in the quince fruits were 3-0-caffeoylquinic acid, catechin, 4-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, coumaric acid, quercetin-3-0-rutinoside and quercetin-3-0-glycosides. The maturity index increase caused in general a reduction of phenolic compounds, these compounds were also influenced by pH and acidity of fruits. Quince is a valuable source of natural phenolic antioxidants, and can be used as raw material to elaborate diverse food products, providing important functional properties

Disponibilidad y costos de producción de biomasa forestal como materia prima para la producción de bioetanol

La biomasa forestal es una alternativa ecológica y económicamente viable para la generación de bioetanol debido a que su fuente es abundante, renovable y contribuye a la reducción de gases efecto invernadero. En este estudio, se propone y analiza una metodología para la estimación de la disponibilidad y costos de producción del uso potencial de la biomasa forestal como materia prima para la producción de bioetanol en bosques de pinos del estado de Durango, México. Se usó información del Inventario Forestal Periódico, programas de manejo forestal y datos de empresas de aserraderos e industriales forestales para estimar la biomasa forestal que incluye los restos de aprovechamientos forestales (puntas, ramas) y desperdicios industriales (aserrín, costeras). Se utilizaron simulaciones Monte Carlo para estimar costos de producción de la recolección, extracción y transporte de la biomasa a centros de transformación. Los resultados indican que alrededor de 322.000 toneladas pueden utilizarse para la producción de 38 millones de litros de etanol por año. Las simulaciones Monte Carlo indican que el costo promedio de residuos forestales es de US $23,8 por tonelada (US$0,20 L–1 etanol) mientras que el de residuos industriales es de US $22,6 por tonelada (US$0,19 L–1 etanol). Los factores más importantes en el análisis de sensibilidad fueron el costo pagado a dueños del material, eficiencia tecnológica y distancia de transporte. En el corto plazo, el uso de la biomasa forestal para la generación de biocombustibles tiene varios retos entre los que se encuentran los costos de transporte y la competencia generada por industrias similares como pulpa, papel y tableros aglomerados. Como alternativa se encuentra el desarrollo de biorefinerías integradoras y el uso de medios de transporte más eficientes.La biomasa forestal es una alternativa ecológica y económicamente viable para la generación de bioetanol debido a que su fuente es abundante, renovable y contribuye a la reducción de gases efecto invernadero. En este estudio, se propone y analiza una metodología para la estimación de la disponibilidad y costos de producción del uso potencial de la biomasa forestal como materia prima para la producción de bioetanol en bosques de pinos del estado de Durango, México. Se usó información del Inventario Forestal Periódico, programas de manejo forestal y datos de empresas de aserraderos e industriales forestales para estimar la biomasa forestal que incluye los restos de aprovechamientos forestales (puntas, ramas) y desperdicios industriales (aserrín, costeras). Se utilizaron simulaciones Monte Carlo para estimar costos de producción de la recolección, extracción y transporte de la biomasa a centros de transformación. Los resultados indican que alrededor de 322.000 toneladas pueden utilizarse para la producción de 38 millones de litros de etanol por año. Las simulaciones Monte Carlo indican que el costo promedio de residuos forestales es de US $23,8 por tonelada (US$0,20 L–1 etanol) mientras que el de residuos industriales es de US $22,6 por tonelada (US$0,19 L–1 etanol). Los factores más importantes en el análisis de sensibilidad fueron el costo pagado a dueños del material, eficiencia tecnológica y distancia de transporte. En el corto plazo, el uso de la biomasa forestal para la generación de biocombustibles tiene varios retos entre los que se encuentran los costos de transporte y la competencia generada por industrias similares como pulpa, papel y tableros aglomerados. Como alternativa se encuentra el desarrollo de biorefinerías integradoras y el uso de medios de transporte más eficientes

Linfoma cutáneo de células B tipo centro folicular con infiltración a médula ósea reporte de un caso

Los linfomas cutáneos primarios de células B constituyen cerca del 20-25% de todos los linfomas. Ellinfoma cutáneo primario de células B tipo centro folicular es el subtipo más frecuente y se manifiesta principalmente en pacientes adultos con una edad media de 58 años (1), la diseminación extra-cutánea es muy rara y se presenta con nódulos, tumores o placas solitarios o en grupo usualmente localizados en cabeza o tronco. Presentamos el caso de una paciente con un linfoma primario cutáneo tipo centro folicular con infiltración a médula ósea

Response to comment on 'Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity'

Lambert et al. question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species

Flower Development as an Interplay between Dynamical Physical Fields and Genetic Networks

In this paper we propose a model to describe the mechanisms by which undifferentiated cells attain gene configurations underlying cell fate determination during morphogenesis. Despite the complicated mechanisms that surely intervene in this process, it is clear that the fundamental fact is that cells obtain spatial and temporal information that bias their destiny. Our main hypothesis assumes that there is at least one macroscopic field that breaks the symmetry of space at a given time. This field provides the information required for the process of cell differentiation to occur by being dynamically coupled to a signal transduction mechanism that, in turn, acts directly upon the gene regulatory network (GRN) underlying cell-fate decisions within cells. We illustrate and test our proposal with a GRN model grounded on experimental data for cell fate specification during organ formation in early Arabidopsis thaliana flower development. We show that our model is able to recover the multigene configurations characteristic of sepal, petal, stamen and carpel primordial cells arranged in concentric rings, in a similar pattern to that observed during actual floral organ determination. Such pattern is robust to alterations of the model parameters and simulated failures predict altered spatio-temporal patterns that mimic those described for several mutants. Furthermore, simulated alterations in the physical fields predict a pattern equivalent to that found in Lacandonia schismatica, the only flowering species with central stamens surrounded by carpels

Porcine colonization of the Americas: a 60k SNP story.

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Mediterranean Sea response to climate change in an ensemble of twenty first century scenarios

The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and quantify the sensitivity of the Mediterranean Sea to the twenty-first century climate change, a set of numerical experiments was carried out with the regional ocean model NEMOMED8 set up for the Mediterranean Sea. The model is forced by air–sea fluxes derived from the regional climate model ARPEGE-Climate at a 50-km horizontal resolution. Historical simulations representing the climate of the period 1961–2000 were run to obtain a reference state. From this baseline, various sensitivity experiments were performed for the period 2001–2099, following different socio-economic scenarios based on the Special Report on Emissions Scenarios. For the A2 scenario, the main three boundary forcings (river runoff, near-Atlantic water hydrography and air–sea fluxes) were changed one by one to better identify the role of each forcing in the way the ocean responds to climate change. In two additional simulations (A1B, B1), the scenario is changed, allowing to quantify the socio-economic uncertainty. Our 6-member scenario simulations display a warming and saltening of the Mediterranean. For the 2070–2099 period compared to 1961–1990, the sea surface temperature anomalies range from +1.73 to +2.97 °C and the SSS anomalies spread from +0.48 to +0.89. In most of the cases, we found that the future Mediterranean thermohaline circulation (MTHC) tends to reach a situation similar to the eastern Mediterranean Transient. However, this response is varying depending on the chosen boundary conditions and socio-economic scenarios. Our numerical experiments suggest that the choice of the near-Atlantic surface water evolution, which is very uncertain in General Circulation Models, has the largest impact on the evolution of the Mediterranean water masses, followed by the choice of the socio-economic scenario. The choice of river runoff and atmospheric forcing both have a smaller impact. The state of the MTHC during the historical period is found to have a large influence on the transfer of surface anomalies toward depth. Besides, subsurface currents are substantially modified in the Ionian Sea and the Balearic region. Finally, the response of thermosteric sea level ranges from +34 to +49 cm (2070–2099 vs. 1961–1990), mainly depending on the Atlantic forcing

Measurement of the Crab Nebula Spectrum Past 100 TeV with HAWC

We present TeV gamma-ray observations of the Crab Nebula, the standard reference source in ground-based gamma-ray astronomy, using data from the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy-estimation methods that utilize extensive air shower variables such as the core position, shower angle, and shower lateral energy distribution. In contrast, the previously published HAWC energy spectrum roughly estimated the shower energy with only the number of photomultipliers triggered. This new methodology yields a much improved energy resolution over the previous analysis and extends HAWC's ability to accurately measure gamma-ray energies well beyond 100 TeV. The energy spectrum of the Crab Nebula is well fit to a log parabola shape $\left(\frac{dN}{dE} = \phi_0 \left(E/\textrm{7 TeV}\right)^{-\alpha-\beta\ln\left(E/\textrm{7 TeV}\right)}\right)$ with emission up to at least 100 TeV. For the first estimator, a ground parameter that utilizes fits to the lateral distribution function to measure the charge density 40 meters from the shower axis, the best-fit values are $\phi_o$=(2.35$\pm$0.04$^{+0.20}_{-0.21}$)$\times$10$^{-13}$ (TeV cm$^2$ s)$^{-1}$, $\alpha$=2.79$\pm$0.02$^{+0.01}_{-0.03}$, and $\beta$=0.10$\pm$0.01$^{+0.01}_{-0.03}$. For the second estimator, a neural network which uses the charge distribution in annuli around the core and other variables, these values are $\phi_o$=(2.31$\pm$0.02$^{+0.32}_{-0.17}$)$\times$10$^{-13}$ (TeV cm$^2$ s)$^{-1}$, $\alpha$=2.73$\pm$0.02$^{+0.03}_{-0.02}$, and $\beta$=0.06$\pm$0.01$\pm$0.02. The first set of uncertainties are statistical; the second set are systematic. Both methods yield compatible results. These measurements are the highest-energy observation of a gamma-ray source to date.Comment: published in Ap