Géraldine Puccini-Delbey, La vie sexuelle à Rome

Aucun mot grec ou latin ne correspond au terme moderne de sexualité, qui n’appartient pas, de fait, aux catégories intellectuelles de l’Antiquité, mais l’étude de la sexualité antique n’en connaît pas moins un grand dynamisme depuis les travaux pionniers de Michel Foucault et Paul Veyne, au début des années 1980. Maître de conférences de littérature latine à l’Université de Bordeaux iii, Géraldine Puccini-Delbey nous en livre le bilan dans un ouvrage consacré à la vie sexuelle des Romains, ré..

Géraldine Puccini-Delbey, La vie sexuelle à Rome

Aucun mot grec ou latin ne correspond au terme moderne de sexualité, qui n’appartient pas, de fait, aux catégories intellectuelles de l’Antiquité, mais l’étude de la sexualité antique n’en connaît pas moins un grand dynamisme depuis les travaux pionniers de Michel Foucault et Paul Veyne, au début des années 1980. Maître de conférences de littérature latine à l’Université de Bordeaux iii, Géraldine Puccini-Delbey nous en livre le bilan dans un ouvrage consacré à la vie sexuelle des Romains, ré..

DYRK1A, a Novel Determinant of the Methionine-Homocysteine Cycle in Different Mouse Models Overexpressing this Down-Syndrome-Associated Kinase

BACKGROUND:Hyperhomocysteinemia, characterized by increased plasma homocysteine level, is associated with an increased risk of atherosclerosis. On the contrary, patients with Down syndrome appear to be protected from the development of atherosclerosis. We previously found a deleterious effect of hyperhomocysteinemia on expression of DYRK1A, a Down-syndrome-associated kinase. As increased expression of DYRK1A and low plasma homocysteine level have been associated with Down syndrome, we aimed to analyze the effect of its over-expression on homocysteine metabolism in mice. METHODOLOGY/PRINCIPAL FINDINGS:Effects of DYRK1A over-expression were examined by biochemical analysis of methionine metabolites, real-time quantitative reverse-transcription polymerase chain reaction, and enzyme activities. We found that over-expression of Dyrk1a increased the hepatic NAD(P)H:quinone oxidoreductase and S-adenosylhomocysteine hydrolase activities, concomitant with decreased level of plasma homocysteine in three mice models overexpressing Dyrk1a. Moreover, these effects were abolished by treatment with harmine, the most potent and specific inhibitor of Dyrk1a. The increased NAD(P)H:quinone oxidoreductase and S-adenosylhomocysteine hydrolase activities were also found in lymphoblastoid cell lines from patients with Down syndrome. CONCLUSIONS/SIGNIFICANCE:Our results might give clues to understand the protective effect of Down syndrome against vascular defect through a decrease of homocysteine level by DYRK1A over-expression. They reveal a link between the Dyrk1a signaling pathway and the homocysteine cycle

The location of the axon initial segment affects the bandwidth of spike initiation dynamics

The dynamics and the sharp onset of action potential (AP) generation have recently been the subject of intense experimental and theoretical investigations. According to the resistive coupling theory, an electrotonic interplay between the site of AP initiation in the axon and the somato-dendritic load determines the AP waveform. This phenomenon not only alters the shape of AP recorded at the soma, but also determines the dynamics of excitability across a variety of time scales. Supporting this statement, here we generalize a previous numerical study and extend it to the quantification of the input-output gain of the neuronal dynamical response. We consider three classes of multicompartmental mathematical models, ranging from ball-and-stick simplified descriptions of neuronal excitability to 3D-reconstructed biophysical models of excitatory neurons of rodent and human cortical tissue. For each model, we demonstrate that increasing the distance between the axonal site of AP initiation and the soma markedly increases the bandwidth of neuronal response properties. We finally consider the Liquid State Machine paradigm, exploring the impact of altering the site of AP initiation at the level of a neuronal population, and demonstrate that an optimal distance exists to boost the computational performance of the network in a simple classification task. Copyright

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

L’entourage gaulois de Constantin

International audienc

Tirage au sort et égalité des voix dans les élections romaines

International audienc

Les femmes dans les émeutes frumentaires à Rome (ier siècle av. J.-C.-iie siècle apr. J.-C.)

Le 5 octobre 1789, le petit peuple de Paris, excédé par les problèmes de ravitaillement, forme une longue colonne et marche sur Versailles pour obtenir le retour du « boulanger, de la boulangère et du petit mitron ». Les femmes dominent la manifestation et leur présence aux avant-postes du cortège a pour avantage d’attendrir les soldats et de rendre plus difficile la répression. Certains hommes se déguisent même en femme pour profiter des avantages liés à ce genre dans un tel contexte. En ces..

Jules César, une biographie expliquée par Christophe Badel - CD

4 CD - Livret 8 pagesLes Presses Universitaires de France et Frémeaux & Associés proposent cette biographie de Jules César, analysée et expliquée par Christophe Badel, professeur d’histoire romaine et spécialiste d’histoire sociale de la noblesse romaine. Le 15 mars 44 av. J.-C., Jules César est assassiné, suspecté de vouloir rétablir la royauté à Rome. Un soupçon qui nimbe de mystère, aujourd’hui encore, la vie du grand homme. En chroniqueur, Christophe Babel mène l’enquête et retrace le parcours d’une personnalité aux multiples facettes, patricien proche du peuple, successivement imperator et dictateur à vie. De l’alliance secrète avec Pompée et Crassus aux jeux somptueux donnés à Rome jusqu’aux campagnes militaires de Gaule, d’Espagne et d’Égypte, l’historien nous conte l’ascension d’une figure politique, à la fois homme d’action et écrivain, dont la postérité n’a que peu d’égal dans l’imaginaire occidental. (Editeur