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631.
Environmental Science and Pollution Research - Agri-food supply chains (AFSCs) are one of the significant building blocks of agricultural production, and their sustainability aims are advanced by...  相似文献   
632.
Environmental Science and Pollution Research - Aquatic organisms are continuously exposed to emerging contaminants coming from urban effluents of wastewater treatment plants. The contamination of...  相似文献   
633.
Environmental Monitoring and Assessment - Downstream water pollution resulting from anthropogenic pressures on upstream water can cause conflicts, especially in transboundary rivers basins. This...  相似文献   
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Prenatal diagnosis of congenital toxoplasmosis relies on the PCR test on amniotic fluid and ultrasound follow-up of the fetus. We report two cases of toxoplasma infection during the first trimester of gestation with a discrepant diagnosis of fetal infection. PCR performed more than four weeks after the estimated date of contamination was negative. Ultrasound follow-up was normal up to the third trimester when major hydrocephalus was detected, leading to pregnancy termination. In both cases, post-mortem examination revealed a diffuse infection with severe brain lesions. These observations confirm the necessity to continue a monthly ultrasound follow-up, even if amniocentesis is negative, in case of fetal toxoplasma infection in pregnancy. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
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We conducted experiments to determine the effect of the increasing ultrasonic/radio transmitter weight on the routine metabolic rate of sea bass. We measured the oxygen consumption (MO2) of fish tagged externally with a dummy transmitter made of a hollow pipe, the weight of which was adjusted with lead to represent in water 0, 1 and 4% (Rtf) of the animal weight. We then developed a theoretical model to estimate, for a given fish size, the range of added weight that fish can compensate for through swimbladder regulation. When RtfБ%, MO2 of untagged and tagged fish did not differ significantly. However, when Rtf reached 4%, fish that carried a tag incurred a significant elevation of oxygen consumption, which represented 28% of their total useable power (or metabolic scope). This result strongly supports the view that a high Rtf ratio contributes to a decrease in available metabolic energy by diverting energy from, e.g., growth or swimming performance. A comparison between the tagged fish and the theoretical model reinforced the hypothesis that, when Rtf attained 4%, the increase in metabolic rate reflected a supplementary and costly swimming effort necessary to maintain vertical position. In this condition, the swimbladder cannot regulate the buoyancy of tagged fish.  相似文献   
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The development of alternative pest-control strategies based on the spatial design of cropping systems requires a thorough understanding of the spatial links between the pest and its environment. Mechanistic models, especially individual-based models (IBMs), are powerful tools for integrating key behaviours, such as habitat selection and dispersal, with spatial heterogeneity. In this paper, we used an IBM calibrated and evaluated from real data to represent the spatial dynamics of the banana weevil in relation to the cropping system. We considered crop fragmentation and mass trapping as tools for suppressing pest numbers. Our simulation results showed that manipulating crop residues in the area surrounding each pheromone trap greatly improved trap efficiency. For an intensive banana plantation in fallow, traps were most effective when situated at the transition zone between banana area and fallow so as to maximize the trapping of weevils escaping the fallow. The model also showed that weevil numbers decreased when fragmentation of banana plantations was reduced.  相似文献   
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