Cap aux Suds. Une orientation globale de la mobilisation contre le sida ?

La pandémie du sida rentre dans sa troisième décennie et draine avec elle des luttes institutionnelles et des combats qui se déclinent sous plusieurs trames historiques et des lignes de différenciation géographique. En lançant notre appel à contributions sur « les mobilisations collectives face au sida dans le monde », nous manifestions une curiosité scientifique sur le Nord comme sur le Sud de la planète. Les réponses que nous avons reçues et les articles qui sont proposés dans ce numéro 7 s..

Parafoveal-on-foveal repetition effects in sentence reading: a co-registered eye-tracking and eeg study

International audienceWhen reading, can the next word in the sentence (word n+1) influence how you read the word you are currently looking at (word n)? Serial models of sentence reading state that this generally should not be the case, whereas parallel models predict that this should be the case. Here we focus on perhaps the simplest and the strongest para-foveal-on-foveal (PoF) manipulation: word n +1 is either the same as word n or a different word. Participants read sentences for comprehension, and when their eyes left word n, the repeated or unrelated word at position n +1 were swapped for a word that provided a syntactically cor-rect continuation of the sentence. We recorded EEG and eye-movements, and time-locked the analysis of fixation-related-potentials (FRPs) to fixation of word n. We found robust PoF repetition effects on gaze durations on word n. Most important is that we also observed significant effects in FRPs, reaching a conservative estimate of significance in a time-window spanning 250-400 ms post-fixation of word n. These effects were marginally significant (after correc-tion) in an earlier 120-250 ms time window and continued into the 400-550 ms time-window. Repetition of the target word n at position n+1 caused a reduced negativity in the FRPs. Given the timing of this effect we argue that it is driven by orthographic processing of word n+1 while read-ers’ eyes are still fixating word n

Social and implementation research for ending AIDS in Africa

International audienc

Chronic blockade of the melanocortin 4 receptor subtype leads to obesity independently of neuropeptide Y action, with no adverse effects on the gonadotropic and somatotropic axes

Neuropeptide Y (NPY) is a powerful orexigenic factor, and alphaMSH is a melanocortin (MC) peptide that induces satiety by activating the MC4 receptor subtype. Genetic models with disruption of MC4 receptor signaling are associated with obesity. In the present study, a 7-day intracerebroventricular infusion to male rats of either the MC receptor antagonist SHU9119 or porcine NPY (10 nmol/day) was shown to strongly stimulate food and water intake and to markedly increase fat pad mass. Very high plasma leptin levels were found in NPY-treated rats (27.1 +/- 1.8 ng/ml compared with 9.9 +/- 0.9 ng/ml in SHU9119-treated animals and 2.1 +/- 0.2 ng/ml in controls). As expected, NPY infusion induced hypogonadism, characterized by an impressive decrease in seminal vesicle and prostate weights. No such effects were seen with the SHU9119 infusion. Similarly, whereas the somatotropic axis of NPY-treated rats was fully inhibited, this axis was normally activated in the obese SHU9119-treated rats. Chronic infusion of SHU9119 strikingly reduced hypothalamic gene expression for NPY (65.2 +/- 3.6% of controls), whereas gene expression for POMC was increased (170 +/- 19%). NPY infusion decreased hypothalamic gene expression for both POMC and NPY (70 +/- 9% and 75.4 +/- 9.5%, respectively). In summary, blockade of the MC4 receptor subtype by SHU9119 was able to generate an obesity syndrome with no apparent side-effects on the reproductive and somatotropic axes. In this situation, it is unlikely that hyperphagia was driven by increased NPY release, because hypothalamic NPY gene expression was markedly reduced, suggesting that hyperphagia mainly resulted from loss of the satiety signal driven by MC peptides. NPY infusion produced hypogonadism and hyposomatotropism in the face of markedly elevated plasma leptin levels and an important reduction in hypothalamic POMC synthesis. In this situation NPY probably acted both by exacerbating food intake through Y receptors and by reducing the satiety signal driven by MC peptides