325 research outputs found

    Reproductive cycle of the razor clam Solen marginatus (Pulteney, 1799) in Eo ria (northwestern Spain)

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    The reproductive cycle of the razor clam Solen marginatus (Pulteney, 1799) was investigated by routine histology. A new approach oriented towards fast monitoring of the gametogenic cycle based on macroscopic observation of gonads is presented. The method, aimed at estimating oocytes size with the aid of a micrometer eyepiece, is reviewed. Phase 0 (sexual rest) occurs in July-August. Phase I (proliferation of gonias) occurs in August-October. Phase II (gametogenesis) develops in November-April. Phase III (reproduction) takes place in May-June. The evolution of the gametogenesis is independent of the size of the specimens.Se estudia el ciclo reproductivo de Solen marginatus (Pulteney, 1799) en la ría del Eo (noroeste de España) mediante histología rutinaria. Se añade un nuevo procedimiento de seguimiento rápido del ciclo gametogénico de la especie basado en la observación de la gónada a escala macroscópica y se revisa el método de estimación del tamaño de los ovocitos mediante ocular micrométrico. La fase 0 (reposo sexual) ocurre en julio-agosto. La fase I (multiplicación de las gonias) sucede en agosto-octubre. La fase II (gametogénesis) se desarrolla en noviembre-abril. La fase III (reproducción) tiene lugar en mayo-junio. La evolución de la gametogénesis es independiente del tamaño de los individuos.Instituto Español de Oceanografí

    Density, biometry and sex ratio of the razor clam Solen marginatus (Pulteney, 1799) in Eo ria (northwestern Spain)

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    Data on the density, biometry and sex ratio of the razor clam Solen marginatus (Pulteney, 1799) are presented. Sampling was performed on the natural beds of Reme and La Reguerira, located in Eo ria, the largest inlet of Asturias region (northwest of Spain). The species was found to be widely distributed along both beds, with no significant differences in density among the different areas compared. The mean density of the species was 31 indiv m-2. Power regression: shell length vs. drained weight, was found to be the most suitable fit. Areas covered by the phanerogam Zostera marina were the most densely inhabited. S. marginatus is diecious, being distributed according to a sex ratio of 1:1. No hermaphrodite specimens were found.Se investiga la densidad, biometría y proporción de sexos de Solen marginatus (Pulteney, 1799) en los bancos naturales de Reme y La Regueira situados en la ría del Eo, el mayor estuario del Principado de Asturias (noroeste de España). La especie se encuentra ampliamente distribuida a lo largo de ambos bancos, sin existir diferencias significativas entre las distintas áreas comparadas. S. marginatus presenta una densidad media de 31 indiv m-2. El mejor ajuste biométrico de la relación longitud de valvas versus peso escurrido corresponde a la regresión potencial. Las áreas cubiertas por la fanerógama marina Zostera marina son las más densamente pobladas. S. marginatus es una especie dioica, distribuida según una proporción de sexos 1:1. No se encontraron individuos hermafroditas.Instituto Español de Oceanografí

    Green Carbon: Making sustainable agriculture real

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    The concept of sustainable development has evolved from a mere movement for the protection of the environment, to other multidimensional approaches. Indeed, today it calls for a holistic approach, seeking to preserve and improve not only the environment, but also to achieve social equity and economic sustainability. In Europe, society demands quality and safe products, not only in the industrial sector but also in agriculture. According to FAO, sustainable agriculture development is a key element of the new global challenges to meet human food security needs at 2050. Unsustainable practices based on intensive soil tillage and agro-chemical applications have increased agri-environmental risks. Whereas world’s food needs are expected to increase by 70% by 2050, agricultural land in Europe will also have to face environmental, economic and social challenges related to sustainable agriculture. As a result, in the EU 2020 Strategy, it is expressed that the new Common Agricultural Policy (CAP) is required to contribute to smart, sustainable and inclusive growth, enhancing social well-being, providing ecosystem services, managing resources sustainably while avoiding environmental degradation. There is broad consensus within the scientific sector that human actions generate a large portion of the greenhouse gas (GHG) emissions, causing global warming. Certainly, Kyoto Protocol states it. According to the European Environmental Agency (EEA), there has been a decrease of 17% in GHG emissions between 1990 and 2009. However, EEA also stressed the importance of the agricultural contribution to total emissions (10.3%). The fossil fuel used in agricultural field operations, along with increasing CO2 emissions from soil through tillage, are considered to be one of the main direct sources of GHG emissions from agriculture sector. Increased inputs required to sustain conventional agriculture also adds significantly to total GHG emissions. Therefore, intensification of production through tillage, agro-chemicals and heavy machinery, which characterizes conventional agriculture in Europe, strongly contributes to increased net GHG emissions instead of mitigating global warming. Sustainable agricultural soil management is crucial for mitigating climate change, especially for the restoration of lost soil organic carbon. In fact, "Agricultural soils management" is recognized as one of the 15 most promising technology options for reducing GHG emissions in the COM (2005) 35 final "Winning the battle against global climate change." The Green Carbon Conference aims to show sustainable management of agricultural soils can help to agriculture mitigate and adapt to climate change, being compatible with the objectives of environmental protection, enhancing biodiversity and supporting farmers’ welfare along with many other environmental, economic and social benefits. Over the last decade, Conservation Agriculture has become known as a set of interlinked agricultural practices, of no or minimum mechanical soil disturbance, maintenance of soil mulch cover, and diversified cropping system, capable of: (a) overcoming several of the severe sustainability limitations of conventional agriculture; and (b) raising productivity, enhancing resilience, reducing degradation and increasing the flow of ecosystem services. The discussion around both the Soil Thematic Strategy initiated in 2002, and the JRC SoCo (Soil Conservation) project clearly recognized the potential of Conservation Agriculture in mitigating and even reversing the problems of soil erosion, soil organic matter decline, soil compaction, loss of biodiversity, climate change vulnerability, among others. Whereas Conservation Agriculture is now practiced successfully on more than 125 million hectares worldwide, Europe has shown to be reluctant with regard to its adoption, despite many promising results confirming its suitability in Europe. Therefore, this European Conference on Green Carbon provides an opportunity to take a leap forward in terms of sharing farmers experiences on Conservation Agriculture across Europe, reviewing the recent progress made in knowledge generation regarding Conservation Agriculture, and to disseminate the outcomes of the currently running LIFE+ Agricarbon (LIFE08 ENV/E/000129). The slogan of ‘Green Carbon’ chosen for this Conference attempts to clarify and highlight the indivisible yet vital link between soil organic carbon and the role that soil health plays in the sustainability of agricultural production and in the flow of ecosystem services. Nevertheless, the topics addressed by the Green Carbon Conference are not only related to the importance of soil organic carbon for the overall soil quality and health, but also include other sustainability issues intimately related to the role of soil carbon such as landscape scale ecosystem functions and services, climate change mitigation and carbon offset, and economic aspects. This Conference also seeks to alert and inform EU policy stakeholders and technical officers of the urgent need to adopt sustainable soil and production practices of Conservation Agriculture to contribute to the objectives of Europe 2020, the EU's growth strategy for the coming decades

    Analyzing the Improvements of Energy Management Systems for Hybrid Electric Vehicles Using a Systematic Literature Review: How Far Are These Controls from Rule-Based Controls Used in Commercial Vehicles?

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    Featured Application This work is useful for researchers interested in the study of energy management systems for hybrid electric vehicles. In addition, it is interesting for institutions related to the market of this type of vehicle. The hybridization of vehicles is a viable step toward overcoming the challenge of the reduction of emissions related to road transport all over the world. To take advantage of the emission reduction potential of hybrid electric vehicles (HEVs), the appropriate design of their energy management systems (EMSs) to control the power flow between the engine and the battery is essential. This work presents a systematic literature review (SLR) of the more recent works that developed EMSs for HEVs. The review is carried out subject to the following idea: although the development of novel EMSs that seek the optimum performance of HEVs is booming, in the real world, HEVs continue to rely on well-known rule-based (RB) strategies. The contribution of this work is to present a quantitative comparison of the works selected. Since several studies do not provide results of their models against commercial RB strategies, it is proposed, as another contribution, to complete their results using simulations. From these results, it is concluded that the improvement of the analyzed EMSs ranges roughly between 5% and 10% with regard to commercial RB EMSs; in comparison to the optimum, the analyzed EMSs are nearer to the optimum than commercial RB EMSs

    Angiosarcoma del muslo: diagnóstico diferencial

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    Se presenta un caso de angiosarcoma de partes blandas en un paciente de 92 años localizado en extremidad inferior de seis meses de evolución. Estos tipos de tumores muestran probabilidades de ser confundidos con hematomas, incluso con estudios de Resonancia Nuclear. Se destaca la ayuda que ofrece para el diagnóstico la arteriografía, así como la agresividad de dichos tumores y los posibles abordajes terapéuticos actuales.A case of angiosarcoma is presented. The patient was 92 years old. The tumor was present 6 months before diagnosis. The tumor was diagnosed by MRN as haematoma of the muscle. Arteriography is a good diagnostic tool before the biopsy in that type of lesions. Alternative treatments of such letal neoplasms are discussed

    Mobilizing Greater Crop and Land Potentials Sustainably

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    The supply side of the food security engine is the way we farm. The current engine of conventional tillage farming is faltering and needs to be replaced. This presentation will address supply side issues of agriculture to meet future agricultural demands for food and industry using the alternate no-till Conservation Agriculture (CA) paradigm (involving no-till farming with mulch soil cover and diversified cropping) that is able to raise productivity sustainably and efficiently, reduce inputs, regenerate degraded land, minimise soil erosion, and harness the flow of ecosystem services. CA is an ecosystems approach to farming capable of enhancing not only the economic and environmental performance of crop production and land management, but also promotes a mindset change for producing ‘more from less’, the key attitude towards sustainable production intensification. CA is now spreading globally in all continents at an annual rate of 10 Mha and covers some 157 Mha of cropland. Today global agriculture produces enough food to feed three times the current population of 7.21 billion. In 1976, when the world population was 4.15 billion, world food production far exceeded the amount necessary to feed that population. However, our urban and industrialised lifestyle leads to wastage of food of some 30%-40%, as well as waste of enormous amount of energy and protein while transforming crop-based food into animal-derived food; we have a higher proportion of people than ever before who are obese; we continue to degrade our ecosystems including much of our agricultural land of which some 400 Mha is reported to be abandoned due to severe soil and land degradation; and yields of staple cereals appear to have stagnated. These are signs of unsustainability at the structural level in the society, and it is at the structural level, for both supply side and demand side, that we need transformed mind sets about production, consumption and distribution. CA not only provides the possibility of increased crop yields for the low input smallholder farmer, it also provides a pro-poor rural and agricultural development model to support agricultural intensification in an affordable manner. For the high output farmer, it offers greater efficiency (productivity) and profit, resilience and stewardship. For farming anywhere, it addresses the root causes of agricultural land degradation, sub-optimal ecological crop and land potentials or yield ceilings, and poor crop phenotypic expressions or yield gaps. As national economies expand and diversify, more people become integrated into the economy and are able to access food. However, for those whose livelihoods continue to depend on agriculture to feed themselves and the rest of the world population, the challenge is for agriculture to produce the needed food and raw material for industry with minimum harm to the environment and the society, and to produce it with maximum efficiency and resilience against abiotic and biotic stresses, including those arising from climate change. There is growing empirical and scientific evidence worldwide that the future global supplies of food and agricultural raw materials can be assured sustainably at much lower environmental and economic cost by shifting away from conventional tillage-based food and agriculture systems to no-till CA-based food and agriculture systems. To achieve this goal will require effective national and global policy and institutional support (including research and education)
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