1000 resultados para Stéphane Vial
Resumo:
Background: Carboxyl/cholinesterases (CCEs) are highly diversified in insects. These enzymes have a broad range of proposed functions, in neuro/developmental processes, dietary detoxification, insecticide resistance or hormone/pheromone degradation. As few functional data are available on purified or recombinant CCEs, the physiological role of most of these enzymes is unknown. Concerning their role in olfaction, only two CCEs able to metabolize sex pheromones have been functionally characterized in insects. These enzymes are only expressed in the male antennae, and secreted into the lumen of the pheromone-sensitive sensilla. CCEs able to hydrolyze other odorants than sex pheromones, such as plant volatiles, have not been identified. Methodology: In Spodoptera littoralis, a major crop pest, a diversity of antennal CCEs has been previously identified. We have employed here a combination of molecular biology, biochemistry and electrophysiology approaches to functionally characterize an intracellular CCE, SlCXE10, whose predominant expression in the olfactory sensilla suggested a role in olfaction. A recombinant protein was produced using the baculovirus system and we tested its catabolic properties towards a plant volatile and the sex pheromone components. Conclusion: We showed that SlCXE10 could efficiently hydrolyze a green leaf volatile and to a lesser extent the sex pheromone components. The transcript level in male antennae was also strongly induced by exposure to this plant odorant. In antennae, SlCXE10 expression was associated with sensilla responding to the sex pheromones and to plant odours. These results suggest that a CCE-based intracellular metabolism of odorants could occur in insect antennae, in addition to the extracellular metabolism occurring within the sensillar lumen. This is the first functional characterization of an Odorant- Degrading Enzyme active towards a host plant volatile.
Resumo:
Road safety has become an increasing concern in developed countries due to the significant amount of fatalities and the associated economic losses. Only in 2005 these losses rose to 200,000 million euros, a considerable sum ¿ approximately 2% of GDP ¿ that easily justifies any public intervention. One measure taken by governments to address this issue is to enact stricter policies and regulations. Since drunk driving is one of the greatest concerns among public authorities in this field, several European countries have lowered their illegal Blood Alcohol Content (BAC) levels to 0.5 mg/ml during the last decade. This study is the first evaluation of the effectiveness of this transition using European panel-based data (CARE) for the period 1991-2003 with the differences-in-differences method in a fixed effects estimation that allows for any pattern of correlation (Cluster-Robust). The results reveal a positive impact on certain groups of road users and on the whole population when the policy is accompanied by enforcement interventions. Moreover, positive results appeared after a time lag of over two years. Finally, I state the importance of controlling for serial correlation in the evaluation of this type of policy.
Resumo:
Road safety has become an increasing concern in developed countries due to the significant amount of fatalities and the associated economic losses. Only in 2005 these losses rose to 200,000 million euros, a considerable sum ¿ approximately 2% of GDP ¿ that easily justifies any public intervention. One measure taken by governments to address this issue is to enact stricter policies and regulations. Since drunk driving is one of the greatest concerns among public authorities in this field, several European countries have lowered their illegal Blood Alcohol Content (BAC) levels to 0.5 mg/ml during the last decade. This study is the first evaluation of the effectiveness of this transition using European panel-based data (CARE) for the period 1991-2003 with the differences-in-differences method in a fixed effects estimation that allows for any pattern of correlation (Cluster-Robust). The results reveal a positive impact on certain groups of road users and on the whole population when the policy is accompanied by enforcement interventions. Moreover, positive results appeared after a time lag of over two years. Finally, I state the importance of controlling for serial correlation in the evaluation of this type of policy.
Resumo:
OBJECTIVES: This study's aim was to describe the emotional status of parents to be before and after the first-trimester combined prenatal screening test. METHODS: One hundred three couples participated, of which 52 had undergone an in vitro fertilization/intracytoplasmic sperm injection treatment [assisted reproductive technology (ART)] and 51 had conceived spontaneously. Participants completed the state scale of the State-trait Anxiety Inventory, the Edinburgh Depression Scale, and the Maternal and Paternal Antenatal Attachment Questionnaire before the first-trimester combined prenatal screening test at around 12 weeks of gestational age (T1) and just after receiving the results at approximately 14 weeks of gestational age (T2). RESULTS: We observed a significant decrease in anxiety and depression symptoms and a significant increase in attachment from T1 to T2. Results showed no differences between groups at either time point, which suggests that ART parents are more similar to than different from parents conceiving spontaneously. Furthermore, given the importance of anxiety during pregnancy, a subsample of women with clinical anxiety was identified. They had significantly higher rates of clinical depression and lower attachment. CONCLUSIONS: These results indicate that, regardless of whether conception was through ART or spontaneous, clinical anxiety in women over the prenatal testing period is associated with more vulnerability during pregnancy (i.e. clinical depression and less attachment to fetus). © 2015 John Wiley & Sons, Ltd.