A balanced gated-mode photon detector for qubit discrimination in 1550 nm

A photon detector combining the two avalanche photon diodes (APD) has been demonstrated for qubit discrimination in 1550 nm. Spikes accompanied with the signals in gated-mode were canceled by balanced output from the two APDs. The spike cancellation enabled one to reduce the threshold in the discriminators, and thus the gate pulse voltage. The dark count probability and afterpulse probability were reduced to 7x10^-7 and 10^-4, respectively, without affecting the detection efficiency (11 %) at 178 K.Comment: 6 pages, 5 figures, submitted to Optics Letters on March 1

Experimental Test of Two-way Quantum Key Distribution in Presence of Controlled Noise

We describe the experimental test of a quantum key distribution performed with a two-way protocol without using entanglement. An individual incoherent eavesdropping is simulated and induces a variable amount of noise on the communication channel. This allows a direct verification of the agreement between theory and practice.Comment: 4 pages, 3 figure

Quantum key distribution with realistic states: photon-number statistics in the photon-number splitting attack

Quantum key distribution can be performed with practical signal sources such as weak coherent pulses. One example of such a scheme is the Bennett-Brassard protocol that can be implemented via polarization of the signals, or equivalent signals. It turns out that the most powerful tool at the disposition of an eavesdropper is the photon-number splitting attack. We show that this attack can be extended in the relevant parameter regime such as to preserve the Poissonian photon number distribution of the combination of the signal source and the lossy channel.Comment: 4 page

Pathological findings on natural infection with Physaloptera praeputialis in cats

To study the pathological changes in the stomach of cat caused by Physaloptera praeputialis, 22 stray cats were euthanized. At necropsies, seven cats were found to be infected with this nematode. Thickening of the stomach wall, congestion and oedema, along with tiny erosions, were observed in gross pathology. Histopathology observations indicated congestion, oedema, leukocytic infiltration, necrosis, hyperplasia and cystic changes of glands and hyperplasia of muscular coat. These changes were indicative of inflammatory and degenerative reaction brought about by parasitic infection with P. praeputialis and its consequent irritating effects on the stomach. This is the second report of pathological observations of P. praeputialis infection in domestic cats

Monoaminergic Modulation of Motor Cortex Function

Elaboration of appropriate responses to behavioral situations rests on the ability of selecting appropriate motor outcomes in accordance to specific environmental inputs. To this end, the primary motor cortex (M1) is a key structure for the control of voluntary movements and motor skills learning. Subcortical loops regulate the activity of the motor cortex and thus contribute to the selection of appropriate motor plans. Monoamines are key mediators of arousal, attention and motivation. Their firing pattern enables a direct encoding of different states thus promoting or repressing the selection of actions adapted to the behavioral context. Monoaminergic modulation of motor systems has been extensively studied in subcortical circuits. Despite evidence of converging projections of multiple neurotransmitters systems in the motor cortex pointing to a direct modulation of local circuits, their contribution to the execution and learning of motor skills is still poorly understood. Monoaminergic dysregulation leads to impaired plasticity and motor function in several neurological and psychiatric conditions, thus it is critical to better understand how monoamines modulate neural activity in the motor cortex. This review aims to provide an update of our current understanding on the monoaminergic modulation of the motor cortex with an emphasis on motor skill learning and execution under physiological conditions

Préhistoire d’un thème

Le témoignage d’Andrée Duby confirme que le thème de l’histoire des femmes émerge progressivement de l’étude de la famille et du mariage conduite depuis le début des années 1960. Peu de participants au séminaire d’Aix ont suivi le maître dans cette voie. Les Procès de Jeanne d’Arc sont une oeuvre commune dont Andrée Duby a assumé la préparation. Mais Georges Duby était bien davantage attiré par la spiritualité franciscaine.Andrée Duby confirms that the theme of the history of women emerged progressively from her husband’s study of family and marriage, undertaken from the beginning of the sixties onwards. Very few of those present at his seminar at Aix followed him in this direction. The Trials of Joan of Arc is a joint-work, for which Andrée Duby was largely responsible. Georges Duby was more attracted, however, by Franciscan spirituality

Les verbes polysémiques en traduction: «glisser» et ses divers sens

L'objectif du présent article est l'étude des mots polysémiques français dont les verbes constituent l’un des problèmes de taille en traduction. Etant très nombreux et inspirant, chacun, une panoplie de sens, ces verbes se trouvent dans la plupart des textes d’où l’ambigüité qui perturbe en général la compréhension du message. Or la problématique relève pour une grande partie de leur variété sémantique et de la méconnaissance des traducteurs- amateurs de leur sens contextuel. Cette recherche a pour objectif de faire un tour d’horizon des verbes polysémiques et de leurs emplois sur les plans sémantico-grammaticaux. L’étude sera effectuée dans le cadre d’un corpus formé de phrases dont le noyau est le verbe polysémique glisser traduisant un large éventail de sens.

Single photon continuous variable quantum key distribution based on energy-time uncertainty relation

In previous quantum key distribution (QKD) protocols, information is encoded on either the discrete-variable of single-photon signal or continuous-variables of multi-photon signal. Here, we propose a new QKD protocol by encoding information on continuous-variables of a single photon. In this protocol, Alice randomly encodes her information on either the central frequency of a narrow-band single photon pulse or the time-delay of a broadband single photon pulse, while Bob randomly chooses to do either frequency measurement or time measurement. The security of this protocol rests on the energy-time uncertainty relation, which prevents Eve from simultaneously determining both frequency and time information with arbitrarily high resolution. In practice, this scheme may be more robust against various channel noises, such as polarization and phase fluctuations.Comment: 4 pages, 3 figure

Maria-Antonietta MACCIOCCHI, Eleonora. La vie passionnée d'Eleonora Fonseca Pimentel dans la Révolution napolitaine, Paris, éditions du félin, 1993, 381 p.

L'auteure, italienne antifasciste dès l'adolescence, ne cache pas, dans son introduction, qu'elle écrit ce livre « comme un récit à deux miroirs ». Intriguée dans son enfance par le personnage de la « savante et poétesse...martyre de la liberté » dont une plaque conserve, à Rome, le souvenir, elle s'identifie largement, devenue adulte, à celle qui dirige et rédige à Naples, sous la Révolution, il Monitore napoletano. Peu connue en France, l'héroïne de la révolution napolitaine, marquis..