3,177 research outputs found
Object oriented design of a thermo-mechanical FEM code
An object oriented design is presented for a computer program that can perform\ud
thermo-mechanically coupled analyzes. The target of the design is a \ud
exible and robust\ud
computer program. It should be easy to adapt and extend, re-using existing code, without\ud
interfering with already established algorithms.\ud
The program uses publicly available toolkits that are currently emerging as C++ pack-\ud
ages. First of all the Standard C++ Library (formerly Standard Template Library) is\ud
used for packing items in container classes. Secondly the matrix and vector operations\ud
are derived from the Template Numerical Toolkit (TNT) and �nally (not essentially for\ud
the numerical part) a graphical user interface is made, based on the wxWindows package,\ud
that can generate a GUI for Motif and MS-Windows with the same code.\ud
Attention is given to the design of classes such as speci�c elements and material classes\ud
based on more general classes. A hierarchy of classes is constructed where general behavior\ud
is put high in the hierarchy and speci�c behavior low. The choice between inheritance and\ud
aggregation is made at several levels
Future governance options for large-scale land acquisition in Cambodia:Impacts on tree cover and tiger landscapes
This paper investigates how large-scale land acquisitions (LSLAs) can be governed to avoid underuse and thereby spare room for other land claims, specifically nature conservation. LSLA underuse occurs when land in LSLAs is not converted to its intended use. Taking Cambodia as a case, we map converted and unconverted areas within LSLAs using remote sensing. We develop three scenarios of alternative LSLA policies until 2040, and use a land system change model to evaluate how governing the underuse of LSLAs affects overall land use. Specifically, we evaluate the impact of these policies on future tree cover, the size and spatial integrity of natural areas, and the potential these natural areas can offer to meet the conservation target of a successful tiger reintroduction. In 2015, only 32% of LSLA area was converted. Simulations suggest that both interventionist (reclaim unconverted areas) and preventive (avoid non-conversion) policies dramatically reduce underuse. Interventionist policies perform best in limiting tree cover loss and in preserving natural areas, but preventive measures lead to significantly less fragmentation. Noninterventionist policies (no enforced policies) make tiger reintroduction in the Eastern Plains impossible. Preventive policies with well-enforced protected areas succeed in creating the largest potential for tiger reintroduction. Our results suggest that Cambodia can reconcile LSLAs with tiger reintroduction in the Eastern Plains only when using preventive land use policies. In the absence of such policies, tiger survival in the Eastern Plains is unlikely and only the Cardamom or Virachey forest may offer such potential
Irrigation water strategies for the Buriti Vermelho watershed: towards a higher water productivity.
RESUMO: Com a necessidade de se utilizar a água de forma cada vez mais eficientemente, faz necessário melhorar a produtividade de uso da água em escala de bacia hidrográfica. Este estudo objetivou avaliar a produtividade de uso da água e a possibilidade de aumentar a área irrigada na bacia hidrográfica do Buriti Vermelho, Brasil. o modelo de Solo-Água-Atmosfera-Planta (SWAP) foi utilizado nas simulações. A bacia do Buriti Vermelho possui agricultura de sequeiro (soja e milho), e irrigada (milho, feijão e trigo). A produtividade de uso da água (CWP) foi calculada em função da lâmina total de água aplicada, que inclui a soma da irrigação e da precipitação. Avaliou-se também o período ideal para o plantio da soja, buscando-se o rendimento ótimo e a maior CWP. A CWP variou de 0,32 kg m-3, para a cultura da soja, a 1,90 kg m-3 para o trigo. Para o período estudado houve uma redução da CWP com o aumento da lâmina de irrigação. A irrigação mostrou ter grande influência no rendimento das culturas do feijão, do trigo e do milho. O rendimento ótimo e a máxima produtividade de uso da água para a soja foram observados no mês de novembro. O cenário futuro mostrou que haverá decréscimo na CWP e que será necessário aplicar mais água para se conseguir as mesmas produtividades. ABSTRACT: As water is required to be used more efficiently, the crop water productivity should be improved. The main objective of this paper was to assess both the crop water productivity and the possibility to expand irrigated land in the Buriti Vermelho experimental watershed, Brazil. Soil-Water-Atmosphere-Plant (SWAP) model was used to perform the analysis. Buriti Vermelho contains both rain fed (soybean and corn) and irrigated (corn, common beans and wheat) crops. The crop water productivity was calculated as a function of total applied water, which includes the sum of irrigation and precipitation. An additional study was performed to verify the most ideal rainfed soybean growth period. The crop water productivity varied from 0.32 kg m-3 for soybeans to 1.90 kg m-3 for wheat. The crop water productivity decreased when the irrigation amount increased. Irrigation showed to have a big influence on the crop yield of common beans, wheat and rainfed corn, caused by a combination of low rainfall and low actual evapotranspiration values with higher irrigation requirements. The results showed November as being the most optimal growth period for soybeans. This month showed both the optimal yield as maximum crop water productivity. The future forecasts a decrease in crop water productivity, what means more water will be needed to reach the same amount of crop yield
Veterinary antibiotic usage in the Netherlands in 2010
The objective of this study is to obtain detailed insight into the exposure of farm animals to antibiotics, by monitoring both sales data at the national level and more specifically data per animal species. The results of the study can be used by the Ministry of Economic Affairs, Agriculture and Innovation for policy evaluation. In addition, the usage data might play a role in explaining trends in resistance that have become apparent
Water for utilities: climate change impacts on water quality and water availability for utilities in Europe
This report provides an assessment of the consequences of changing water availability for production of drinking water, the manufacturing industry and power production in Europe, due to climate change and socio-economic developments. The report is based up on projections of demographic and socio-economic trends and climate change impacts, according to the SRES A2 and B1 scenario’s also used by IPC
Wild plant and animal genetic resources
Wild resources from ecosystems around the globe have been used for millennia to meet people’s basic needs for food, fuel, medicines, tools and materials, and for spiritual and cultural uses. Today, many species are still used for subsistence and as a basis for trade. This chapter provides an introduction to the range of species gathered from forests, shrub and grasslands, fresh water and oceans, and their uses. Two particularities distinguishing wild genetic resources from cultivated ones are discussed: Many wild species are governed as public goods or common property, raising questions about if and how they are managed, and by whom, and how access to, and benefits from, these resources is arranged. How these resources (and the ecosystems which provide them) are governed affects their sustainability. Sustainability also depends on factors such as (a) the abundance of the species from which a product originates; (b) direct anthropogenic factors such as forest degradation, as well as semi-natural ones such as climate change threats; (c) inherent species vulnerability which depends on the part(s) of the organism used; and (d) a species’ tolerance to harvesting. The chapter illustrates how knowledge of these aspects helps our understanding of why and when wild species have been domesticated and also, when resources are sourced only from the wild, the conservation issues which are likely to arise
Effects of Different Production Systems on the Nutrient Density of Beef
As concerns regarding beef production systems on human health and animal welfare become more apparent, consumer interest in pasture-raised livestock has been steadily on the rise in the US. Such interest has increasingly led to questions about potential nutritional composition differences in beef from different production systems, such as grass-fed beef and grain-fed beef. The goal of this work was to conduct untargeted metabolomics analysis on a broad range of samples from the US beef supply chain to provide insight into how different finishing systems impact the beef metabolome and nutrient density. Here, we found that 191 out of 802 profiled compounds were different between grass-fed and grain-fed ribeye steaks (all, p \u3c 0.05), with phytochemicals, vitamins, lipid, and amino acid metabolites emerging as the most discriminatory metabolite classes. On average, phytochemicals were 1.7-fold higher in grass-fed beef compared to grain-fed beef (p \u3c 0.05) with considerable variation (4.4-fold) amongst individual farms, particularly within grass-fed beef systems. Alpha-tocopherol was 2-fold elevated in grass-fed beef, while nicotinamide was 1.3-fold elevated in grain-fed beef, respectively (p \u3c 0.05). We also observed that 4- hydroxy-nonenal-glutathione, a common marker of oxidative stress, was 2.7-fold elevated in grain-fed beef samples (p \u3c 0.05), with a 20-fold variation across individual farms. Future work will identify the source(s) of variation and best practices in beef systems to improve beef nutrient density and animal metabolic health
Blood pressures, heart rate and locomotor activity during salt loading and angiotensin II infusion in protease-activated receptor 2 (PAR2) knockout mice
<p>Abstract</p> <p>Background</p> <p>In this study we used radiotelemetry to measure hemodynamic variables and locomotor activity in conscious unrestrained male Protease-Activated Receptor 2 (PAR-2) knockout mice in order to provide a detailed assessment of their blood pressure phenotype. In addition we tested for an influence of PAR-2 on salt-sensitivity (8% versus 0.5% NaCl diet, 2.5 weeks) and angiotensin II-induced hypertension (1 μg Ile<sup>5</sup>-angiotensin II/kg/min versus 0.25 μl/h saline, 2 weeks).</p> <p>Results</p> <p>Systolic arterial pressures of PAR-2 -/- (129 ± 1 mmHg, n = 21, P < 0.05) were statistically higher than those of C57BL/6J (124 ± 1 mmHg, n = 33) throughout the 24 h period under baseline conditions. Pulse pressures in PAR-2 -/- were also significantly elevated (33 ± 1 mmHg versus 30 ± 1 mmHg, P < 0.05), whereas diastolic arterial pressures were not. Heart rates in PAR-2 -/- were not significantly different than controls, with the exception that heart rate of PAR-2 -/- was 23 beats per min higher than controls (<it>P </it>< 0.001) during periods of nocturnal activity. The diurnal pattern and intensity of locomotor activity were not found to differ between strains. A high salt diet led to increased blood pressures, decreased heart rates, increased time spent active and decreased intensity levels of locomotor activity. Salt-induced changes in systolic and pulse pressures in PAR-2 -/- were less than in C57B/6J. Angiotensin II treatment increased pressures, decreased heart rates, decreased time spent active and decreased intensity levels of activity of PAR-2 -/-, all to the same extent as C57BL/6J. A trend of lower blood pressures during the middle period of angiotensin II treatment period was observed in individual PAR-2 -/-.</p> <p>Conclusion</p> <p>The data indicated gene knockout of PAR-2 was associated with a modest change in blood pressure phenotype. PAR-2 -/- mice exhibited moderate elevation of systolic arterial and pulse pressures, yet no increased diastolic arterial pressure, no increased blood pressure responses to high salt diet and a subtle difference in the time course of the blood pressure responses to angiotensin II infusion.</p
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