Enforcing Secure Object Initialization in Java

Sun and the CERT recommend for secure Java development to not allow partially initialized objects to be accessed. The CERT considers the severity of the risks taken by not following this recommendation as high. The solution currently used to enforce object initialization is to implement a coding pattern proposed by Sun, which is not formally checked. We propose a modular type system to formally specify the initialization policy of libraries or programs and a type checker to statically check at load time that all loaded classes respect the policy. This allows to prove the absence of bugs which have allowed some famous privilege escalations in Java. Our experimental results show that our safe default policy allows to prove 91% of classes of java.lang, java.security and javax.security safe without any annotation and by adding 57 simple annotations we proved all classes but four safe. The type system and its soundness theorem have been formalized and machine checked using Coq

Trait-anxiety dependence of movement time performance in a bimodal choice task in subjects exposed to moderate anxiogenic conditions

International audienceRecent studies have provided insight into the interdependence between state-anxiety, trait-anxiety and motor performances. In the present study, we investigated in very low trait-anxiety (VLTA) and normal trait-anxiety (NTA) subjects, the effects of moderate state-anxiety induced by the video-recorded Stroop color word interference test, on reaction time and movement time in bimodal choice response time task providing either visual or auditory modality. We found that in anxiogenic condition, movement time performances were improved in visual modality in NTA subjects, and in auditory modality in VLTA subjects. Our results show that depending on their trait-anxiety level, individuals exposed to anxiogenic condition would allocate attentional resources towards a specific relevant modality. Such attentional resources would influence movement time, but not reaction time

What is the initiation step of the Grubbs-Hoveyda olefin metathesis catalyst?

Density function theory calculations reveal that the Grubbs-Hoveyda olefin metathesis pre-catalyst is activated by the formation of a complex in which the incoming alkene substrate and outgoing alkoxy ligand are both clearly associated with the ruthenium centre. The computed energies for reaction are in good agreement with the experimental values, reported here

Hand osteoarthritis: clinical phenotypes, molecular mechanisms and disease management

Osteoarthritis (OA) is a highly prevalent condition and the hand is the most commonly affected site. Patients with hand OA frequently report symptoms of pain, functional limitations, and frustration in undertaking everyday activities. The condition presents clinically with changes to the bone, ligaments, cartilage and synovial tissue, which can be observed using radiography, ultrasonography or MRI. Hand OA is a heterogeneous disorder and is considered to be multifactorial in aetiology. This review provides an overview of the epidemiology, presentation and burden of hand OA, including an update on hand OA imaging (including the development of novel techniques), disease mechanisms and management. In particular, areas for which new evidence has substantially changed the way we understand, consider and treat hand OA are highlighted. For example, genetic studies, clinical trials and careful prospective imaging studies from the past 5 years are beginning to provide insights into the pathogenesis of hand OA that might uncover new therapeutic targets in disease

Une horloge dans le cerveau

International audienc

Interruption dans la reproduction d'une durée : effet sur la précision du jugement temporel

International audienc

Rôle du cortrex frontal dans les processus mnésiques impliqués dans l'estimation du temps (apport des potentiels évoqués)

Le but de ce travail était d'étudier les corrélats électrophysiologiques de l'encodage, du maintien et de la récupération de durées brèves afin de déterminer l'implication du cortex frontal dans ces processus mnésiques. Nous avons enregistré l'activité électrique cérébrale de sujets jeunes (20-30 ans) dans des tâches temporelles mettant en oeuvre la mémoire de travail et la mémoire à long terme. La présence d'une Variation Contingente Négative (VCN) ample au niveau des régions frontales droites lors de l'encodage et de la récupération en mémoire des durées suggère que ces régions sous-tendent spécifiquement la formation du jugement temporel. L'amplitude de l'activité des régions frontales gauches dépendrait de la difficulté de la tâche et de l'implication de processus attentionnels nécessaires à une estimation précise du temps. Le niveau de l'activité frontale lors du maintien temporaire de durées varie en fonction du nombre de durées maintenues et de leur degré de manipulation pendant le maintien. Ces données attestent du rôle important du cortex frontal au sein des réseaux neuronaux qui sous-tendent l'estimation du temps.This work was aimed at examining the electrophysiological correlates of encoding brief durations, maintaining them in memory and retrieving them from it, in order to determine the involvement of frontal cortex in these memory processes. The cerebral electrical activity of young subjects (20-30 years) was recorded during temporal tasks implying working and long-term memory. A great Contingent Negative Variation (CNV) was recorded on right frontal sites during encoding and retrieval of target durations. This suggests that right frontal regions play a specific role in the formation of temporal judgments. Results also indicate that the amplitude of left frontal activity depend on the difficulty of the task and on the level of involvement of attentional mechanisms underlying accurate estimation of time. Finally, the amplitude of frontal activity during temporary maintaining of temporal information has been shown to vary in function of the quantity and degree of manipulation of this information. The whole results assess that the frontal cortex plays an important role in the neural networks which sub-serve the estimation of time.PARIS5-BU Saints-Pères (751062109) / SudocBOULOGNE-BU Psych. Henri Pieron (920125201) / SudocSudocFranceF