366 research outputs found

    Using a Crop Model to Benchmark Miscanthus and Switchgrass

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    Crop yields are important items in the economic performance and the environmental impacts of second-generation biofuels. Since they strongly depend on crop management and pedoclimatic conditions, it is important to compare candidate feedstocks to select the most appropriate crops in a given context. Agro-ecosystem models offer a prime route to benchmark crops, but have been little tested from this perspective thus far. Here, we tested whether an agro-ecosystem model (CERES-EGC) was specific enough to capture the differences between miscanthus and switchgrass in northern Europe. The model was compared to field observations obtained in seven long-term trials in France and the UK, involving different fertilizer input rates and harvesting dates. At the calibration site (Estrées-Mons), the mean deviations between simulated and observed crop biomass yields for miscanthus varied between −0.3 t DM ha−1 and 4.2 t DM ha−1. For switchgrass, simulated yields were within 1.0 t DM ha−1 of the experimental data. Observed miscanthus yields were higher than switchgrass yields in most sites and for all treatments, with one exception. Overall, the model captured the differences between both crops adequately, with a mean deviation of 0.46 t DM ha−1, and could be used to guide feedstock selections over larger biomass supply areas

    Integrated heterodyne array receivers for submillimeter astronomy

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    The advent of large format (~100 pixel) spectroscopic imaging cameras at submillimeter wavelengths would fundamentally change the way in which astronomy is performed in this important wavelength regime. While the possibility of such instruments has been discussed for more than two decades, only recently have advances in mixer technology, device fabrication, micromachining, digital signal processing, and telescope design made the construction of such an instrument possible and economical. In our paper, we will present the design concept for a 10×10 heterodyne camera

    New damage curves and multimodel analysis suggest lower optimal temperature

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    Economic analyses of global climate change have been criticized for their poor representation of climate change damages. Here we develop and apply aggregate damage functions in three economic Integrated Assessment Models (IAMs) with different degrees of complexity. The damage functions encompass a wide but still incomplete set of climate change impacts based on physical impact models. We show that with medium estimates for damage functions, global damages are in the range of 10% to 12% of GDP by 2100 in a baseline scenario with 3 °C temperature change, and about 2% in a well-below 2 °C scenario. These damages are much higher than previous estimates in benefit-cost studies, resulting in optimal temperatures below 2 °C with central estimates of damages and discount rates. Moreover, we find a benefit-cost ratio of 1.5 to 3.9, even without considering damages that could not be accounted for, such as biodiversity losses, health and tipping points

    Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

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    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed

    Integrated heterodyne array receivers for submillimeter astronomy

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    The advent of large format (~100 pixel) spectroscopic imaging cameras at submillimeter wavelengths would fundamentally change the way in which astronomy is performed in this important wavelength regime. While the possibility of such instruments has been discussed for more than two decades, only recently have advances in mixer technology, device fabrication, micromachining, digital signal processing, and telescope design made the construction of such an instrument possible and economical. In our paper, we will present the design concept for a 10×10 heterodyne camera

    Comparison of ankle-brachial pressure index and pulse wave velocity as markers of cognitive function in a community-dwelling population

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    <p>Abstract</p> <p>Background</p> <p>Vascular factors have been implicated in the development of cognitive decline and dementia. The purpose of this study is to determine the association of the Ankle Brachial pressure Index (ABI) and brachial-ankle Pulse Wave Velocity (ba-PWV) to cognitive impairment in a community-dwelling population.</p> <p>Methods</p> <p>The ABI and ba-PWV were measured using the volume-plethymographic apparatus in 388 subjects aged 60 years old and over. The Mini-Mental State Examination was also employed to measure global cognitive status. The effectiveness of the ABI and ba-PWV as putative markers of cognitive impairment were determined by using a multiple logistic regression analysis after adjusting for confounding factors.</p> <p>Results</p> <p>Subjects with poor cognition were significantly older and less well educated than those with normal cognition. According to the multiple logistic regression analysis, the lowest ABI tertile was found to be a significant independent risk factor (OR = 3.19, 95% CI = 1.30 to 7.82) of the cognitive impairment, whereas the highest brachial-ankle PWV tertile was not.</p> <p>Conclusions</p> <p>A low ABI was an independent risk factor for cognitive impairment in community-dwelling older populations, whereas a high ba-PWV may not be. Further research will be required to analyze ABI and PWV with greater accuracy.</p
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