407 research outputs found

    Splitting of the middle layer of LPW SAFNWC/MSG satellite product in order to improve the monitoring of pre-convective environments

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    International audienceSeven of the infrared channels from the Spinning Enhanced Visible and Infrared Imagery (SEVIRI) instrument, on board the Meteosat Second Generation (MSG), are used to retrieve Layer Precipitable Water (LPW) and Stability Analysis Imagery (SAI) in the SAFNWC framework. Both products are retrieved using a statistical retrieval based on neural networks; they are routinely generated every fifteen minutes at a satellite horizontal resolution of 3 km in NADIR only in cloud-free areas. Many factors are involved in the development of severe weather and these parameters are only some of the indicators. However, due to the high resolution of these products, the use of them in conjunction with satellite and radar images can help to identify mesoscale features related to convection. The MSG moisture and parcel instability time trend fields are especially useful during the period previous to convection. Once the outbreak of convection occurs, the products calculated in the clear air pixels surrounding the convective system can give us hints to anticipate its evolution. SAFNWC LPW and SAI were analyzed for a severe weather event during August 2004. A thunderstorm over Teruel (Spain) produced intense precipitation and hail; a tornado developed while this thunderstorm was moving towards SE. The pre-convective parcel potential buoyancy and moisture SAFNWC products changed in a way that was consistent with the observed intense convective activity. In previous studies, the atmospheric moisture in medium levels, which has been proven to be relevant in some cases, was represented by only one level parameter (ML: middle layer LPW). However, it was observed that this layer is too thick to do an adequate analysis of moisture available for convection. Hence, an improvement on the LPW algorithm has been carried out by splitting the middle layer into two new sub-layers (approximately separated at 700 hPa) and training two new neural networks. The impact of monitoring moisture in the new sub-layers separately in this severe weather event has been tested, and the improvements achieved have been evaluated

    N-transfer through aspen litter and feather moss layers after fertilization with ammonium nitrate and urea

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    When fertilizer is broadcast in boreal forest stands, the applied nutrients must pass through a thick layer of either feather moss or leaf litter which covers the forest floor. In a growth chamber experiment we tested the transfer of N through living feather moss or aspen litter when fertilized with urea ((NH2)2CO) or NH4NO3 at a rate of 100 kg ha−1 and under different watering regimes. When these organic substrates were frequently watered to excess they allowed the highest transfer of nutrients through, although 72% of the applied fertilizer was captured in the substrates. In a field experiment we also fertilized moss and aspen litter with urea ((NH2)2CO) or NH4NO3 at a more operationally relevant rate of 330 kg ha−1. We captured the NO3− or NH4+ by ion exchange resin at the substrate–mineral soil interface. In contrast to the growth chamber experiment, this fertilizer rate killed the moss and there was no detectable increase in nutrient levels in the aspen litter or feather moss layers. Instead, the urea was more likely transferred into the mineral soil; mineral soil of the urea treatment had 1.6 times as much extractable N compared to the NH4NO3 treatment. This difference between the growth chamber and field studies was attributed to observed fertilizer- damage to the living moss and possibly damage to the litter microflora due to the higher rate of fertilization in the field. In addition, the early and substantial rainfall after fertilization in the field experiment produced conditions for rapid leaching of N through the organic layers into the mineral soil. In the field, only 8% of the urea-N that was applied was captured by the ion exchange resin, while 34% was captured in for the NH4NO3 fertilization. Thus, the conditions for rapid leaching in the field moved much of the N in the form of urea through the organic layers and into the mineral soil before it was hydrolyzed

    Shifts in the suitable habitat available for brown trout (Salmo trutta L.) under short-term climate change scenarios

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    The impact of climate change on the habitat suitability for large brown trout (Salmo trutta L.) was studied in a segment of the Cabriel River (Iberian Peninsula). The future flow and water temperature patterns were simulated at a daily time step with M5 models' trees (NSE of 0.78 and 0.97 respectively) for two short-term scenarios (2011 2040) under the representative concentration pathways (RCP 4.5 and 8.5). An ensemble of five strongly regularized machine learning techniques (generalized additive models, multilayer perceptron ensembles, random forests, support vector machines and fuzzy rule base systems) was used to model the microhabitat suitability (depth, velocity and substrate) during summertime and to evaluate several flows simulated with River2D©. The simulated flow rate and water temperature were combined with the microhabitat assessment to infer bivariate habitat duration curves (BHDCs) under historical conditions and climate change scenarios using either the weighted usable area (WUA) or the Boolean-based suitable area (SA). The forecasts for both scenarios jointly predicted a significant reduction in the flow rate and an increase in water temperature (mean rate of change of ca. −25% and +4% respectively). The five techniques converged on the modelled suitability and habitat preferences; large brown trout selected relatively high flow velocity, large depth and coarse substrate. However, the model developed with support vector machines presented a significantly trimmed output range (max.: 0.38), and thus its predictions were banned from the WUA-based analyses. The BHDCs based on the WUA and the SA broadly matched, indicating an increase in the number of days with less suitable habitat available (WUA and SA) and/or with higher water temperature (trout will endure impoverished environmental conditions ca. 82% of the days). Finally, our results suggested the potential extirpation of the species from the study site during short time spans.The study has been partially funded by the IMPADAPT project (CGL2013-48424-C2-1-R) - Spanish MINECO (Ministerio de Economia y Competitividad) - and FEDER funds and by the Confederacion Hidrografica del Jucar (Spanish Ministry of Agriculture, Food and Environment). We are grateful to the colleagues who worked in the field and in the preliminary data analyses, especially Juan Diego Alcaraz-Henandez, David Argibay, Aina Hernandez and Marta Bargay. Thanks to Matthew J. Cashman for the academic review of English. Finally, the authors would also to thank the Direccion General del Agua and INFRAECO for the cession of the trout data. The authors thank AEMET and UC by the data provided for this work (dataset Spain02).Muñoz Mas, R.; López Nicolás, AF.; Martinez-Capel, F.; Pulido-Velazquez, M. (2016). Shifts in the suitable habitat available for brown trout (Salmo trutta L.) under short-term climate change scenarios. Science of the Total Environment. 544:686-700. https://doi.org/10.1016/j.scitotenv.2015.11.14768670054

    Presentación, clasificación y evolución de los pacientes con carcinoma hepatocelular en un centro de Veracruz, México

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    ResumenAntecedentesLa estadificación en el carcinoma hepatocelular (CHC) otorga pronóstico y orientación terapéutica. La resección y el trasplante hepático son opciones curativas y las terapias de ablación se aplican a pacientes que no reciben tratamiento curativo. La sobrevida tras la resección hepática o terapias de ablación es variada.ObjetivoDescribir la presentación, la estadificación, el manejo y la evolución de los pacientes con CHC en nuestro centro.Pacientes y métodosCuarenta y dos pacientes fueron seguidos prospectivamente durante 7 años. La sobrevida se calculó mediante Kaplan-Meier y log-rank entre los sistemas de estadificación (Okuda, BCLC y CLIP) y tipos de tratamiento (resección hepática, ablación por radiofrecuencia y ningún tratamiento quirúrgico).ResultadosLa edad media ± desviación estándar de los pacientes fue 68,9 ± 9,5 años; el 57% fueron mujeres y el 54% cirróticos. El 31% tenía infección por VHC. El tamaño medio del tumor fue 6.48 ± 2.52cm. Los estadios CLIP 0, Okuda I y BCLC A tuvieron mejor sobrevida que otros estadios (p<0.05). La resección tuvo mejor sobrevida (mediana: 32 meses y sobrevida a 1, 3 y 5 años del 83, el 39 y 19.7%) que ablación por radiofrecuencia (25 meses, y el 90 y el 17.2% a 1 y 3 años) y que ningún tratamiento quirúrgico (1 año<5%) (p<0.05).ConclusiónLos pacientes con CHC en nuestro centro al igual que otra población en México son diagnosticados tardíamente. El pronóstico usando CLIP y BCLC es similar a la literatura. Los mejores resultados se observaron en estadios tempranos y los que tuvieron resección quirúrgica del CHC.AbstractBackgroundHepatocellular carcinoma (HCC) staging provides a basis for calculating disease prognosis and therapeutic guidance. Liver resection and transplantation are curative options, and ablation therapies are applied to patients that are not candidates for curative treatment. Survival after liver resection or ablation therapies varies.AimsTo describe the presentation, staging, management, and outcome in patients with HCC in our center.Patients and methodsForty-two patients had a 7-year prospective follow-up. Survival was calculated with the Kaplan-Meier analysis and the log-rank test was used for its comparison between the staging systems (Okuda, BCLC, and CLIP) and types of treatment (liver resection, radiofrequency ablation, and no surgical treatment).ResultsThe mean age of the patients was 68.9 ± 9.5 years; 57% were women. A total of 54% of the patients presented with cirrhosis and 31% were infected with hepatitis C virus (HCV). The mean tumor size was 6.48 ± 2.52cm. The CLIP 0, Okuda I, and BCLC A stages had better survival rates than the other stages (P<0.05). Survival with resection was superior (median of 32 months and survival at 1, 3, and 5 years of 83, 39, and 19.7%, respectively) to that of both radiofrequency ablation (median of 25 months and survival at 1 and 3 years of 90 and 17.2%, respectively) and no surgical treatment (1 year < 5%) (P<0.05).ConclusionThe patients at our center were diagnosed at late stages of HCC, as is the case in other Mexican populations. Outcome in relation to CLIP and BCLC was similar to the prognoses reported in the literature. The best results were observed in the patients with early stage disease and those that underwent HCC resection surgery

    Hydrological Modeling of the Effect of the Transition From Flood to Drip Irrigation on Groundwater Recharge Using Multi-Objective Calibration

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    [EN] The replacement of flood-irrigation systems by drip-irrigation technology has been widely promoted with the aim of a more sustainable use of freshwater resources in irrigated agriculture. However, evidence for an irrigation efficiency paradox emphasizes the need to improve our understanding of the impacts of irrigation transformations on water resources. Here, we developed a distributed hydrological modeling approach to investigate the spatiotemporal effect of flood and drip irrigation on groundwater recharge. The approach recognizes differences in the water balance resulting from the localized application of water in surface drip-irrigated fields and the more extensive application of water in flood irrigation. The approach was applied to the semi-arid Mediterranean region of Valencia (Spain) and calibrated using a multi-objective framework. Multiple process scales were addressed within the framework by considering the annual evaporative index, monthly groundwater level dynamics, and daily soil moisture dynamics. Daily simulations from 1994 to 2015 suggested that, in our hydroclimatic conditions, (a) annual recharge is strongly related to annual rainfall, which had a four times higher impact on recharge than the type of irrigation practice, (b) flood-irrigated recharge tends to exceed drip-irrigated recharge by 10% at annual time scales, (c) however, recharge response to a particular precipitation event is smaller in flood irrigation than in drip irrigation, and (d) 8¿18 rainfall events could generate more than half of the annual recharge in drip and flood irrigation, respectively. Our results highlight the importance of understanding the hydrological dynamics under different irrigation practices for supporting irrigation infrastructure policies.The authors thank the Coop Research Program on ¿Sustainability in Food Value Chains¿ of the ETH Zurich World Food System Center and the ETH Zurich Foundation for supporting this project. The Coop Research Program is supported by the Coop Sustainability Fund. The authors also acknowledge the financial support from the Spanish Ministry of Science and Innovation through the research project TETISCHANGE (RTI2018-093717-B-100). This work was additionally supported by the ADAPTAMED research project funded by the Spanish Ministry of Science and Innovation (RTI2018-101483-B-I00) with European FEDER funds. The support of Andreas Scheidegger (Eawag) for statistical questions is also acknowledgedPool, S.; Francés, F.; Garcia-Prats, A.; Puertes, C.; Pulido-Velazquez, M.; Sanchis Ibor, C.; Schirmer, M.... (2021). Hydrological Modeling of the Effect of the Transition From Flood to Drip Irrigation on Groundwater Recharge Using Multi-Objective Calibration. Water Resources Research. 57(8):1-19. https://doi.org/10.1029/2021WR029677S11957

    Project: Center for Diabetes and Metabolism [Centro de Diabetes y Metabolismo: CeDiMet], a collaborative dream comes true

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    Reynosa urban area has 690,000 inhabitants (384,000 adults \u3e20 years old), 35% moved from other states. The use of cell phones is in 81%, personal computer or laptop with 29%. The prevalence of overweight is 39%, obesity 36%, and T2D 13%. The expected adult population with T2D is 49,900 individuals. The are 5 clinics prepared to attend T2D, and few with specialized personnel. The CeDiMet is a collaborative clinic involving health personnel and researchers from the Universidad Mexico Americana del Norte, Universidad Autonoma de Tamaulipas, Hospital General de Mexico “Dr. Eduardo Liceaga”, University of Texas Rio Grande Valley, and the Texas Diabetes Institute in San Antonio. The funding source comes from private companies in Reynosa. The clinical structure includes physicians, nurses, nutritionists, psychologists, and a section for telemedicine for consulting specialists from USA and Mexico City. Besides clinical attendance, the CeDiMet will conduct educational activities in offices, factories, churches, and schools for prevention of obesity complications (T2D and hypertension), early detection of diabetic foot, fatty liver, and endothelial damage. “Tree of Health in the Family” is a program to encourage youth to know and understand the metabolic problems in their families to focus on prevention. Recently, we obtained a grant from COTACyT to explore the effect of COVID-19 in a cohort of 200 students and their families. The analysis of post-traumatic stress due to confinement and antibodies concentration to detect contacts and its association with metabolic problems is an example of the research we can perform

    The 2HWC HAWC Observatory Gamma Ray Catalog

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    We present the first catalog of TeV gamma-ray sources realized with the recently completed High Altitude Water Cherenkov Observatory (HAWC). It is the most sensitive wide field-of-view TeV telescope currently in operation, with a 1-year survey sensitivity of ~5-10% of the flux of the Crab Nebula. With an instantaneous field of view >1.5 sr and >90% duty cycle, it continuously surveys and monitors the sky for gamma ray energies between hundreds GeV and tens of TeV. HAWC is located in Mexico at a latitude of 19 degree North and was completed in March 2015. Here, we present the 2HWC catalog, which is the result of the first source search realized with the complete HAWC detector. Realized with 507 days of data and represents the most sensitive TeV survey to date for such a large fraction of the sky. A total of 39 sources were detected, with an expected contamination of 0.5 due to background fluctuation. Out of these sources, 16 are more than one degree away from any previously reported TeV source. The source list, including the position measurement, spectrum measurement, and uncertainties, is reported. Seven of the detected sources may be associated with pulsar wind nebulae, two with supernova remnants, two with blazars, and the remaining 23 have no firm identification yet.Comment: Submitted 2017/02/09 to the Astrophysical Journa

    The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

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    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.Comment: 15 pages, 4 figures, version to be published in PR
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