2,647 research outputs found

    Experimental analysis of drainage and water storage of litter layers

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    International audienceMany hydrological studies of forested ecosystems focus on the study of the forest canopy and have partitioned gross precipitation into throughfall and stemflow. However, the presence of forest litter can alter the quantities of water available for soil infiltration and runoff. Little information exists regarding the value of storage and drainage parameters for litter layers. Vegetation parameters of this kind are required in physically-based and lumped conceptual models to quatify the availabilty and distribution of water. Using a rainfall simulator and laboratory conditions two main objectives were investigated using layers of recently seneced poplar leaves, fresh grass or woodchips: 1) Effect of rain intensity on storage. With this respect we found that: maximum storage (Cmax), defined as the detention of water immediately before rainfall cessation, increased with rainfall intensity. The magnitude of the increment was up to 0.5 mm kg?1 m?2 between the lowest (9.8 mm h?1) and highest (70.9 mm h?1) rainfall intensities for poplar leaves. Minimum storage (Cmin), defined as the detention of water after drainage ceased, was not influenced by rainfall intensity. Repeated wetting-draining cycles or layer thickness have no effect on Cmax or Cmin. 2) The evaluation of drainage coefficient for the Rutter model. This model was found accurate to predict storage and drainage in the case of poplar leaves, was less accurate for fresh grass and resulted in overestimations for woodchips. Additionally, the effect of an underlaying soil matrix on lateral movement of water and storage of poplar leaves was studied. Results indicated that the soil matrix have no effect on Cmax or Cmin of the litter layer. Lateral movement of water in the poplar layer was observed at intermediate rainfall intensities (30.2 and 40.4 mm h?1), but not a the lowest or highest rates

    Postharvest heat treatments to inhibit Penicillium digitatum growth and maintain quality of Mandarin (Citrus reticulata blanco)

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    Use of fungicides is a common practice as a postharvest treatment to control fruit decay. Nowadays, environment-friendly technologies, such as heat treatments, are viable replacements. This study evaluated the effects of post-harvest heat treatments (traditional and microwave-assisted) on mandarins intentionally inoculated with Penicillium digitatum. For the studied heat treatments, the target temperature was 50C, which was held for 2.5 min. After heating, mandarins were cooled and stored at 25C for 13 days. MW treatments effectively prevented mold growth during storage, while HW only delayed it. Control mandarins (without treatment) showed the highest significant weight loss. Neither thermal treatment nor storage affected fruit juice pH (p \u3e 0.05). Treated mandarins had a significantly lower vitamin C content than control fruits throughout storage, and all mandarins lost firmness by the 13th day (p \u3c 0.05). Control and MW-treated mandarins had lower citric acid content; however, they retained color, total soluble solids (TSS) and had a higher maturity index. While HW mandarins did not have changes in citric acid content, they had higher TSS, and lower maturity index. MW-assisted treatments were effective at inactivating molds and helped retain some nutritional and physical-chemical characteristics of mandarins. However, juice of MW-treated mandarins was not preferred by judges in the sensory tests, the juice was rated lower than that obtained from the other treatment. Postharvest heat treatments may constitute a helpful application to control mandarin’ fungal decay

    Impact of land use on the hydraulic properties of the topsoil in a small French catchment

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    The hydraulic properties of the topsoil control the partition of rainfall into infiltration and runoff at the soil surface. They must be characterized for distributed hydrological modelling. This study presents the results of a field campaign documenting topsoil hydraulic properties in a small French suburban catchment (7 km2) located near Lyon, France. Two types of infiltration tests were performed: single ring infiltration tests under positive head and tension disk infiltration using a mini-disk. Both categories were processed using the BEST Beerkan Estimation of Soil Transfer parameters- method to derive parameters describing the retention and hydraulic conductivity curves. Dry bulk density and particle size data were also sampled. Almost all the topsoils were found to belong to the sandy loam soil class. No significant differences in hydraulic properties were found in terms of pedologic units, but the results showed a high impact of land use on these properties. The lowest dry bulk density values were obtained in forested soils with the highest organic matter content. Permanent pasture soils showed intermediate values, whereas the highest values were encountered in cultivated lands. For saturated hydraulic conductivity, the highest values were found in broad leaved forests and small woods. The complementary use of tension disk and positive head infiltration tests highlighted a sharp increase of hydraulic conductivity between near saturation and saturated conditions, attributed to macroporosity effect. The ratio of median saturated hydraulic conductivity to median hydraulic conductivity at a pressure of -20 mm of water, was about 50. The study suggests that soil texture, such as used in most pedo-transfer functions, might not be sufficient to properly map the variability of soil hydraulic properties. Land use information should be considered in the parameterizations of topsoil within hydrological models to better represent in situ conditions, as illustrated in the paper

    Exploring the natural history of intrinsic capacity impairments: longitudinal patterns in the 10/66 study

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    Backgroundintrinsic capacity (IC) is a construct encompassing people’s physical and mental abilities. There is an implicit link amongst IC domains: cognition, locomotion, nutrition, sensory and psychological. However, little is known about the integration of the domains.Objectivesto investigate patterns in the presentation and evolution of IC domain impairments in low-and-middle-income countries and if such patterns were associated with adverse outcomes.Methodssecondary analyses of the first two waves of the 10/66 study (population-based surveys conducted in eight urban and four rural catchment areas in Cuba, Dominican Republic, Puerto Rico, Venezuela, Peru, Mexico and China). We applied latent transition analysis on IC to find latent statuses (latent clusters) of IC domain impairments. We evaluated the longitudinal association of the latent statuses with the risk of frailty, disability and mortality, and tested concurrent and predictive validity.Resultsamongst 14,923 participants included, the four latent statuses were: high IC (43%), low deterioration with impaired locomotion (17%), high deterioration without cognitive impairment (22%), and high deterioration with cognitive impairment (18%). A total of 61% of the participants worsened over time, 35% were stable, and 3% improved to a healthier status.Participants with deteriorated IC had a significantly higher risk of frailty, disability and dementia than people with high IC. There was strong concurrent and predictive validity. (Mortality Hazard Ratio = 4.60, 95%CI 4.16; 5.09; Harrel’s C = 0.73 (95%CI 0.72;0.74)).Conclusionshalf of the study population had high IC at baseline, and most participants followed a worsening trend. Four qualitatively different IC statuses or statuses were characterised by low and high levels of deterioration associated with their risk of disability and frailty. Locomotion and cognition impairments showed other trends than psychological and nutrition domains across the latent statuses

    Ocurrencia de la enfermedad Hoja de malvon en zonas vitícolas de Catamarca y La Rioja, Argentina

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    PosterLa ‘hoja de malvón’ (HM) es la principal enfermedad de la madera de la vid detectada en el país, en plantas adultas y diferentes variedades. Está asociada a especies de la familia Botryosphaeriaceae, Phaeoacremonium spp., Arambarria destruens y Phaeomoniella chlamydospora. En Catamarca y La Rioja, reviste un problema importante dada la elevada superficie de viñedos adultos con variedades susceptibles. El trabajo busca (i) determinar la incidencia y la severidad de la enfermedad y (ii) correlacionar síntomas aéreos, lesiones en madera y especies fúngicas aisladas. Durante el periodo 2019-2021, se prospectaron viñedos afectados y se extrajeron muestras de madera de plantas adultas sintomáticas. Las muestras fueron desinfectadas en hipoclorito de sodio al 2%, enjuagas en ADE y desinfectadas con alcohol 70°. Pequeñas porciones de madera de la zona de transición se sembraron en medio APG. Las cepas fúngicas obtenidas fueron diferenciadas por caracteres macro y micromorfólogicos y se utilizaron claves taxonómicas para aproximar al estado de género. En ambas provincias, la HM está presente en las zonas vitícolas, con elevada incidencia (85%) y severidad (75%) para las variedades Cabernet Sauvignon, Torrontés riojano y Malbec. Se identificaron cinco tipos de lesiones en madera (necrosis marginal, radial, central, puntuaciones negras y pudrición blanda) asociadas al mismo complejo de síntomas en la parte aérea. Lasiodiplodia spp., Botryosphaeria spp., y Phaeoacremonium spp., estuvieron relacionados a las necrosis, Phaeomoniella chlamydospora a las puntuaciones y Phaeoacremonium spp., a la pudrición blanda. Los resultados obtenidos aportan al conocimiento del patosistema HM.EEA CatamarcaFil: Carrasco, Franca Denise. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Catamarca; ArgentinaFil: Oviedo, Hector Javier. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Catamarca; ArgentinaFil: Gonzalez Ribot, Joaquin Victor. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chilecito; ArgentinaFil: Sosa, Pablo Antonio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Catamarca; ArgentinaFil: Sosa, Flavio Isaac. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Catamarca; ArgentinaFil: Maza, Claudia Elizabeth. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chilecito; ArgentinaFil: Bustos, E. Universidad Nacional de Catamarca. Facultad de Ciencias Agrarias; ArgentinaFil: Longone, Maria Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Escoriaza, Maria Georgina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin

    Comparación en los resultados de pacientes con bronquiolitis manejados con dos diferentes métodos de administrar oxígeno. Informe preliminar de avance del Hospital General de Niños Dr. Pedro de Elizalde

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    Introducción: La oxigenoterapia en el tratamiento de niños con bronquiolitis puede ser administrada mediantes cánulas nasales con bajo o alto flujo (CNAF). Las CNAF podrían ser una alternativa a la ventilación no invasiva, requiriendo menos recursos que los cuidados intensivos (UCIP). Objetivo: Evaluar si existe diferencia en la proporción de sujetos hospitalizados por bronquiolitis que requiere UCIP o en la duración de su hospitalización, según oxigenoterapia (convencional o CNAF). Métodos: Estudio observacional incluyendo lactantes hospitalizados por bronquiolitis en los meses de junio a agosto de 2017. Los pacientes fueron tratados según el servicio donde se encontraban (las unidades 1, 2 y 3 con oxigenoterapia convencional, y las unidades 4 y 5 con CNAF), al que fueron asignados según disponibilidad de cama. Resultados: Se incluyeron 329 pacientes, con edad promedio de 7,2 meses, que permanecieron hospitalizados 5,9 días y recibieron 4,6 días de oxigenoterapia. Todos recibieron oxigenoterapia, 84 (25,5%) CNAF y 245 (74,5%) convencional. Sólo 10 (3,1%) requirieron UCIP. De los que ingresaron a UCIP 5/84 recibieron CNAF y 5/245 recibieron terapia convencional (OR: 3,1; IC 95%: 0,8-10,7; p=0,07). Los pacientes con CNAF permanecieron significativamente más tiempo hospitalizados (6,9 ± 3,9 días vs. 5,6 ±3,2; p=0,003), luego de controlar por edad, la etiología viral y requerimiento de UCIP. Conclusión: En la población analizada no se observó diferencia en la proporción de pacientes que requirieron UTIP según hubieran recibido oxigenoterapia por CNAF o en forma convencional.Background: Oxygen in bronchiolitis treatment can be delivered by nasal cannulas using low or high flow (HFNC). HFNC can be an alternative to non-invasive ventilation or intensive care (PICU). Objective: To evaluate PICU requirement and length of stay (LOS) according to oxygen delivery method in children hospitalized for bronchiolitis. Methods: Observational study including infants hospitalized for bronchiolitis from June to August 2017. Patients received oxygen based on to the unit in which they were hospitalized (units 1, 2 and 3 received conventional oxygen therapy, while units 4 and 5 received HFNC), assigned according to bed availability. Results: We included 329 patients, aged 7.2 months, with a LOS of 5.9 days, and receiving oxygen for 4.6 days. All of them received oxygen, 84 (25.5%) HFNC and 245 (74,5%) conventional therapy. Only 10 (3.1%) required PICU, 5 using HFNC and 5 on conventional therapy (OR: 3,1; 95%IC: 0.8-10.7; p=0.07). After controlling for age, viral etiology and PICU requirement, patients on HFNC showed a significantly longer LOS (6.9 ± 3.9 vs. 5.6 ± 3.2 days; p=0.003). Conclusion: Patients who received oxygen trough HFNC required PICU less frequently than those in conventional therapy but showed a longer length of stay.Fil: Potasnik, J.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Golubicki, A.. Ministerio de Salud de la Nación; ArgentinaFil: Fernandez, A.. Gobierno de la Ciudad Autonoma de Buenos Aires. Hospital General de Agudos Carlos Durand.; ArgentinaFil: Raiden, Silvina Claudia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Sosa, R.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Gonzalez, N.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Cairoli, H.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: De Lillo, L.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Sanluis Fenelli, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Planovsky, H.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Checacci, E.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Lopez, M.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Gigliotti, E.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Torres, F.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Ferrero, F.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); Argentin

    The AVuPUR project (Assessing the Vulnerabiliy of Peri-Urbans Rivers): experimental set up, modelling strategy and first results

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    International audienceLe projet AVuPUR a pour objectif de progresser sur la compréhension et la modélisation des flux d'eau dans les bassins versants péri-urbains. Il s'agit plus particulièrement de fournir des outils permettant de quantifier l'impact d'objets anthropiques tels que zones urbaines, routes, fossés sur les régimes hydrologiques des cours d'eau dans ces bassins. Cet article présente la stratégie expérimentale et de collecte de données mise en ½uvre dans le projet et les pistes proposées pour l'amélioration des outils de modélisation existants et le développement d'outils novateurs. Enfin, nous présentons comment ces outils seront utilisés pour simuler et quantifier l'impact des modifications d'occupation des sols et/ou du climat sur les régimes hydrologiques des bassins étudiés. / The aim of the AVuPUR project is to enhance our understanding and modelling capacity of water fluxes within suburban watersheds. In particular, the objective is to deliver tools allowing to quantify the impact of anthropogenic elements such as urban areas, roads, ditches on the hydrological regime of suburban rivers. This paper presents the observation and data collection strategy set up by the project, and the directions for improving existing modelling tools or proposing innovative ones. Finally, we present how these tools will be used to simulate and quantify the impact of land use and climate changes on the hydrological regimes of the studied catchments

    Randomized Clinical Trials of obesity treatments in Mexican population. Systematic Review and Meta-Analysis

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    Background: Mexicans and Mexican Americans share similar culture, genetic background, and predisposition for obesity and diabetes. Randomized clinical trials (RCT) assessing obesity treatments (ObT) are reliable to assess efficacy. To date, there is no systematic review to investigate ObT tested by RCT in Mexican adults. Methods: We conducted systematic searches in Pubmed, Scopus, and Web of Science to retrieve ObT RCT from 1990 to 2019. The ObT included alternative medicine, pharmacological, nutritional, behavioral, and surgical interventions. The analyzed RCT were at least three months of duration, and reported: BMI, weight, waist circumference, triglycerides, glucose and blood pressure. Results: We found 634 entries; after removal of duplicates and exclusions based on eligibility criteria, we analyzed 43 and 2 multinational-collaborative studies. Most of the national studies had small sample sizes, and did not have replications from other studies. The nutrition/behavioral interventions were difficult to blind, and most studies had medium to high risk of bias. Random effects meta-analysis of nutritional/behavioral interventions and medications showed effects on BMI, waist circumference, and blood pressure. Simple measures like plain water instead of sweet beverages decreased triglycerides and systolic blood pressure. Participants with obesity and hypertension had beneficial effects with antioxidants, and the treatment with insulin increased weight in those with T2D. Conclusions: The RCT’s in Mexico reported effects on metabolic components despite small sample sizes and lack of replication. In the future we should analyze ObT in population living on the U.S.-Mexico border; therefore, bi-national collaboration is desirable to disentangle cultural effects on ObT response
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