Corollary Discharge Failure in an Oculomotor Task Is Related to Delusional Ideation in Healthy Individuals

International audiencePredicting the sensory consequences of saccadic eye movements likely plays a crucial role in planning sequences of saccades and in maintaining visual stability despite saccade-caused retinal displacements. Deficits in predictive activity, such as that afforded by a corollary discharge signal, have been reported in patients with schizophrenia, and may lead to the emergence of positive symptoms, in particular delusions of control and auditory hallucinations. We examined whether a measure of delusional thinking in the general, non-clinical population correlated with measures of predictive activity in two oculomotor tasks. The double-step task measured predictive activity in motor control, and the in-flight displacement task measured predictive activity in trans-saccadic visual perception. Forty-one healthy adults performed both tasks and completed a questionnaire to assess delusional thinking. The quantitative measure of predictive activity we obtained correlated with the tendency towards delusional ideation, but only for the motor task, and not the perceptual task: Individuals with higher levels of delusional thinking showed less self-movement information use in the motor task. Variation of the degree of self-generated movement knowledge as a function of the prevalence of delusional ideation in the normal population strongly supports the idea that corollary discharge deficits measured in schizophrenic patients in previous researches are not due to neuroleptic medication. We also propose that this difference in results between the perceptual and the motor tasks may point to a dissociation between corollary discharge for perception and corollary discharge for action

Total synthesis of (–)-luminacin D

A second generation synthesis of (?)-luminacin D based on an early stage introduction of the trisubstituted epoxide group is reported, allowing access to the natural product in an improved yield and a reduced number of steps (5.4%, 17 steps vs 2.6%, 19 steps). A full account of the optimization work is provided, with the reversal of stereoselection in the formation of the C4 alcohol in equally excellent diastereoselectivity as key improvement

Profiling substrate promiscuity of wild-type sugar kinases for multifluorinated monosaccharides

Fluorinated sugar-1-phosphates are of emerging importance as intermediates in the chemical and biocatalytic synthesis of modified oligosaccharides, as well as probes for chemical biology. Here we present a systematic study of the activity of a wide range of anomeric sugar kinases (galacto- and N-acetylhexosamine kinases) against a panel of fluorinated monosaccharides, leading to the first examples of polyfluorinated substrates accepted by this class of enzymes. We have discovered four new N-acetylhexosamine kinases with a different substrate scope, thus expanding the number of homologs available in this subclass of kinases. Lastly, we have solved the crystal structure of a galactokinase in complex with 2-deoxy-2-fluoro galactose, giving insight into changes in the active site that may account for the specificity of the enzyme towards certain substrate analogues

Politique agricole, politique alimentaire, politique agro-alimentaire

[fre] Cet article définit trois champs d'analyse : agricole, alimentaire et agro-alimentaire. La politique alimentaire est plus particulièrement envisagée dans deux de ses aspects : la politique du pouvoir d'achat des consommateurs et celle de l'aide directe à la consommation alimentaire. L'Europe a certes une politique agricole, mais elle n'a pas de politique alimentaire proprement dite. La nouvelle PAC met l'accent sur la gestion de l'offre, mais la gestion de la demande ne semble pas avoir reçu l'attention qu'elle mérite. [eng] Agricultural policy, food policy, agrofood policy . This article defines three fields of analysis : one agricultural, one alimentary and one agro alimentary. Alimentary policy is more specially viewed under two of its aspects : consommers purchasing power policy ans direct help to alimentary consumption policy. Europe certainly has an agricultural policy but not a real alimentary policy. The new Common Agricultural Policy insist on the management of the offer, but the management of the demand do not seem to have received the merited attention.