142 research outputs found

    A practical method for gas changing time estimation using a simple gas-liquid mass transfer model

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    The present work explains a practical and simple method to calculate the gas changing time of anaerobic systems. It is substantiated under the physics of gas-liquid transfer theory and allows researchers to obtain an approximate value of gas changing time with few measurements of the gas composition in the outlet of the reactor. The only analytical equipment required is a gas analyzer, and calculations can be done using a spreadsheet. Along with the validation of the model, a short guide for its application in the laboratory is introduced. The model fits the experimental data with less than 1% error in the composition of the out-gas when no carbon dioxide is involved. This method will allow savings in valuable resources such as time and gases while providing greater comprehension of the characteristics of the gas-liquid transfer of the studied system

    Howard walnut trees can be brought into bearing without annual pruning

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    In traditionally managed Howard walnut orchards, trees are pruned annually during the orchard development phase, an expensive operation in terms of labor and prunings disposal costs. Our observations and some prior research by others had suggested that pruning may not be necessary in walnut. In a trial of pruned and unpruned hedgerow trees over 8 years, beginning a year after planting, we documented canopy growth, tree height, yield and nut quality characteristics and also the effects of fruit removal. Pruning altered canopy shape but did not lead to increases in canopy development, yield or nut quality. Although fruit removal stimulated more vegetative growth in both the pruned and unpruned treatments, fruit removal did not result in an increase in midday canopy photosynthetically active radiation interception or cumulative yield when fruit removal was stopped after year 4. After 8 years, there were no significant differences in tree height, nut quality or cumulative yield among any of the treatments, which suggests that not pruning young Howard orchards could provide a net benefit to growers

    Differences in proleptic and epicormic shoot structures in relation to water deficit and growth rate in almond trees (Prunus dulcis)

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    UMR 1334 AGAP : Equipe AFEF "Architecture et Fonctionnement des Espèces fruitières" ; Team AFFS "Architecture and Functioning of Fruit Species"International audienceBackground and Aims Shoot characteristics differ depending on the meristem tissue that they originate from and environmental conditions during their development. This study focused on the effects of plant water status on axillary meristem fate and flowering patterns along proleptic and epicormic shoots, as well as on shoot growth rates on 'Nonpareil' almond trees (Prunus dulcis). The aims were (1) to characterize the structural differences between pro-leptic and epicormic shoots, (2) to determine whether water deficits modify shoot structures differently depending on shoot type, and (3) to determine whether shoot structures are related to shoot growth rates. Methods A hidden semi-Markov model of the axillary meristem fate and number of flower buds per node was built for two shoot types growing on trees exposed to three plant water status treatments. The models segmented observed shoots into successive homogeneous zones, which were compared between treatments. Shoot growth rates were cal-culated from shoot extension measurements made during the growing season. Key Results Proleptic shoots had seven successive homogeneous zones while epicormic shoots had five zones. Shoot structures were associated with changes in growth rate over the season. Water deficit (1) affected the occurrence and lengths of the first zones of proleptic shoots, but only the occurrence of the third zone was reduced in epicormic shoots; (2) had a minor effect on zone flowering patterns and did not modify shoot or zone composition of axillary meristem fates; and (3) reduced growth rates, although patterns over the season were similar among treatments. Conclusions Two meristem types, with different latency durations, produced shoots with different growth rates and distinct structures. Differences between shoot type structure responses to water deficit appeared to reflect their onto-genetic characteristics and/or resource availability for their development. Tree water deficit appeared to stimulate a more rapid progression through ontogenetic states

    Studying the influence of livestock pressure on gully erosion in rangelands of SW Spain by means of the UAV+SfM workflow

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    Gully erosion in agrosilvopastoral systems of SW Spain represents a common degradation process, but has been hardly analysed. The suitability of using the Unmanned Aerial Vehicles (UAV) and Structure from Motion photogrammetry (SfM) workflow to map small valley-bottom gullies in these landscapes was tested. The results showed centimetre-level accuracy. Observed strengths and limitations of the UAV+SfM workflow in the study areas are discussed. The resulting cartography allowed mapping soil erosion forms at outstanding spatial scales. All study areas showed evidences of degradation

    Compliance with current dietary recommendations and geographical variability of diet in women participating in 7 screening programs for breast cancer in Spain

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    Introducción: Una dieta saludable es especialmente importante durante la menopausia, periodo en el que aumenta el riesgo de varios problemas de salud. Analizamos la dieta de mujeres peri y postmenopáusicas españolas y el grado de cumplimiento de las recomendaciones actuales. Material y métodos: Estudio transversal en 3.574 mujeres de 45-68 años que acuden al cribado de cáncer de mama en 7 centros (A Coruña, Barcelona, Burgos, Palma de Mallorca, Pamplona, Valencia y Zaragoza). Se recogió la dieta mediante un cuestionario de frecuencia de alimentos validado para población española. Para la valoración del cumplimiento de las recomendaciones actuales se utilizaron los rangos recomendados por la Sociedad Española de Nutrición Comunitaria para ingesta de grupos de alimentos y las Ingestas Diarias Recomendadas (IDR) para energía, vitaminas y minerales de la Federación Española de Nutrición, Alimentación y Dietética. Resultados: El 29% de las mujeres eran obesas y un 42% tenía sobrepeso. El aporte calórico medio fue de 2.053 kcal (DE: 480). El perfil calórico general fue de: 43% de la energía aportada por lo carbohidratos, 36% por las grasas, 20% por las proteínas. Se evidenció una ingesta deficiente de vitamina D en todos los nodos del estudio, con una ingesta media general de 2,14 μg/día. Se detectó a su vez una ingesta deficitaria de vitamina E en A Coruña y Burgos. Todos los centros presentaron una ingesta elevada de productos lácteos y de legumbres. El consumo de frutas y verduras fue muy heterogéneo siendo especialmente elevada su ingesta en Mallorca y Valencia mientras que fue baja para ambos grupos de alimentos en A Coruña. La ingesta de aceite de oliva fue elevada en todos los centros exceptuando Burgos con un 74,3% de las mujeres estudiadas por debajo de las 3 raciones al día recomendadas. Conclusiones: Una dieta con menos grasas y proteínas y más rica en vegetales, frutos secos y alimentos ricos en hidratos de carbono equilibraría el balance energético y mejoraría la calidad de la dieta corrigiendo las bajas ingestas de vitaminas D y E. Estas recomendaciones son especialmente importantes en las ciudades más alejadas de la costa mediterránea donde se han detectado mayores incumplimientos de las recomendaciones vigentes y una dieta más alejada de la dieta mediterránea.Introduction: A healthy diet is especially important during menopause, a period which increases the risk of various health problems. We analyzed the diet of periand postmenopausal Spanish women and the degree of compliance with current recommendations. Material and methods: We studied 3574 women 45-68 years old who attended breast cancer screening programmes in 7 centres (A Coruña, Barcelona, Burgos, Palma de Mallorca, Pamplona, Valencia and Zaragoza). Diet information was collected using a food frequency questionnaire validated for the Spanish population. For the assessment of compliance with current guidelines we used the recommendations by the Spanish Society of Community Nutrition for food groups intake and by the Spanish Federation of Nutrition, Food and Dietetics for energy, vitamins and minerals intake. Results: The 29% of women were obese and 42% overweight. The average caloric intake was 2.053 kcal (SD 480). The general energy profile was: 43% of the energy from the carbohydrates, 36% from fats, and 20% from proteins. There was a low vitamin D intake in all centres of the study, with an overall mean intake of 2.14 mg/day. A deficit of vitamin E intake in A Coruña and Burgos was also detected. Intake of dairy products and vegetables was high in all the study centers. The consumption of fruits and vegetables was very heterogeneous, with high intakes observed in Mallorca and Valencia and low for both food groups in A Coruña. The olive oil intake was high in all centers except Burgos with 74.3% of the women studied below the recommended 3 servings per day. Conclusions: A diet with less fat and protein and a higher consumption of vegetables, nuts and foods rich in carbohydrate might balance the energy intake and improve the quality of the diet correcting the low intakes of vitamins D and E. These recommendations are especially important in cities far from the Mediterranean coast where more breaches have been detected over the current recommendations with a lower adherence to the Mediterranean diet.Este estudio ha recibido financiación del Fondo de Investigación Sanitaria (proyecto PI060386) y de Astra-Zéneca (convenio de colaboración entre Astra- Zeneca y el Instituto de salud Carlos III 1306-1306 EPY

    Primer registro de Vespula vulgaris (Linnaeus 1758) (Hymenoptera: Vespidae) en la isla Navarino, Chile

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    The common wasp Vespula vulgaris (Linnaeus 1758) is an introduced species in the Southern Hemisphere that has been reported in Australia, New Zealand, Tasmania, Argentina and South-central Chile. This report documents the presence of V. vulgaris on Navarino Island, Cape Horn Biosphere Reserve, Southern Chile.La avispa común Vespula vulgaris (Linnaeus 1758) es una especie introducida en el Hemisferio Sur que ha sido registrada en Australia, Nueva Zelanda, Tasmania, Argentina y Chile central. Este trabajo documenta la presencia de V. vulgaris en la isla Navarino, Reserva de la Biósfera Cabo de Hornos, sur de Chile

    Energy Sprawl or Energy Efficiency: Climate Policy Impacts on Natural Habitat for the United States of America

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    Concern over climate change has led the U.S. to consider a cap-and-trade system to regulate emissions. Here we illustrate the land-use impact to U.S. habitat types of new energy development resulting from different U.S. energy policies. We estimated the total new land area needed by 2030 to produce energy, under current law and under various cap-and-trade policies, and then partitioned the area impacted among habitat types with geospatial data on the feasibility of production. The land-use intensity of different energy production techniques varies over three orders of magnitude, from 1.9–2.8 km2/TW hr/yr for nuclear power to 788–1000 km2/TW hr/yr for biodiesel from soy. In all scenarios, temperate deciduous forests and temperate grasslands will be most impacted by future energy development, although the magnitude of impact by wind, biomass, and coal to different habitat types is policy-specific. Regardless of the existence or structure of a cap-and-trade bill, at least 206,000 km2 will be impacted without substantial increases in energy efficiency, which saves at least 7.6 km2 per TW hr of electricity conserved annually and 27.5 km2 per TW hr of liquid fuels conserved annually. Climate policy that reduces carbon dioxide emissions may increase the areal impact of energy, although the magnitude of this potential side effect may be substantially mitigated by increases in energy efficiency. The possibility of widespread energy sprawl increases the need for energy conservation, appropriate siting, sustainable production practices, and compensatory mitigation offsets
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