Macroeconomic Effects of Terrorist Shocks in Israel

This paper estimates a structural vector autoregression model to assess the dynamic effects of terrorism on output and prices in Israel over the post-1985 period. Long-run restrictions are used to obtain an interpretation of the effects of terrorism in terms of aggregate demand and supply curves. The empirical responses of output and prices suggest that the immediate effects of terrorism are similar to those associated with a negative demand shock. Such leftward shift of the aggregate demand curve is consistent with the adverse effects of terrorism on most components of aggregate expenditure, which have been documented in previous studies. In contrast, the long-term consequences of terrorism are similar to those related to a negative supply shock. Such leftward shift of the long-run aggregate supply curve suggests the potential existence of adverse effects of terrorism on the determinants of potential output, which have not been considered so far.Goods market, output, price, and terrorist indices, structural vector autoregressions, long-run identifying restrictions, dynamic responses and variance decompositions

Postprandial lipemia and fecal fat excretion in rats is affected by the calcium content and type of milk fat present in Cheddar-type cheeses

The aim of this study was to better understand the effect of calcium on the bioavailability of milk lipids from a cheese matrix using a rat model. Cheddar-type cheeses were manufactured with one of three types of anhydrous milk fat, control, olein or stearin, and salted with or without CaCl₂. The cheeses were fed to rats and postprandial lipemia was monitored. Feces were analyzed to quantify fatty acids excreted as calcium soaps. Higher calcium concentration in cheese caused a higher and faster triacylglycerol peak in blood, except for cheeses containing stearin. Furthermore, calcium soaps were more abundant in feces when the ingested cheese had been enriched with calcium and when the cheese was prepared with stearin. Increased lipid excretion was attributable to the affinity of saturated long-chain fatty acids for calcium. Results showed that lipid bioaccessibility can be regulated by calcium present in Cheddar cheese. This study highlights the nutritional interaction between calcium and lipids present in the dairy matrix and confirms its physiological repercussions on fatty acid bioavailability

Degradation of pathogen quorum-sensing molecules by soil bacteria: a preventive and curative biological control mechanism

The plasmid pME6863, carrying the aiiA gene from the soil bacterium Bacillus sp. A24 that encodes a lactonase enzyme able to degrade N-acyl-homoserine lactones (AHLs), was introduced into the rhizosphere isolate Pseudomonas fluorescens P3. This strain is not an effective biological control agent against plant pathogens. The transformant P. fluorescens P3/pME6863 acquired the ability to degrade AHLs. In planta, P. fluorescens P3/pME6863 significantly reduced potato soft rot caused by Erwinia carotovora and crown gall of tomato caused by Agrobacterium tumefaciens to a similar level as Bacillus sp. A24. Little or no disease reduction was observed for the wild-type strain P3 carrying the vector plasmid without aiiA. Suppression of potato soft rot was observed even when the AHL-degrading P. fluorescens P3/pME6863 was applied to tubers 2 days after the pathogen, indicating that biocontrol was not only preventive but also curative. When antagonists were applied individually with the bacterial plant pathogens, biocontrol activity of the AHL degraders was greater than that observed with several Pseudomonas 2,4-diacetylphloroglucinol-producing strains and with Pseudomonas chlororaphis PCL1391, which relies on production of phenazine antibiotic for disease suppression. Phenazine production by this well characterized biological control strain P. chlororaphis PCL1391 is regulated by AHL-mediated quorum sensing. When P. chlororaphis PCL1391 was co-inoculated with P. fluorescens P3/pME6863 in a strain mixture, the AHL degrader interfered with the normally excellent ability of the antibiotic producer to suppress tomato vascular wilt caused by Fusarium oxysporum f. sp. lycopersici. Our results demonstrate AHL degradation as a novel biocontrol mechanism, but also demonstrate the potential for non-target interactions that can interfere with the biocontrol efficacy of other strain

Le fonctionnement intellectuel d'étudiants réalisant des expériences : observation de séances de travaux pratiques en premier cycle universitaire scientifique

Ce travail tente de caractériser les opérations intellectuelles d'étudiants de début d'université, pendant l'activité même de manipulation, lors de travaux pratiques (TP). Les étudiants sont guidés par un polycopié apportant des informations théoriques et donnant des procédures expérimentales. Les observations ont été faites «in vivo» et les données récoltées interprétées avec des catégories utilisées par les psychologues dans le paradigme du traitement de l'information. Ainsi l'activité intellectuelle des étudiants peut être interprétée par la juxtaposition de «réseaux d'actions» et de «réseaux de concepts", les premiers étant les plus prégnants lors des TP qui ont été observés