Constraints on the parity-violating couplings of a new gauge boson

High-energy particle physics experiments allow for the possible existence of a new light, very weakly coupled, neutral gauge boson (the U boson). This one permits for light (spin-1/2 or spin-0) particles to be acceptable Dark Matter candidates, by inducing sufficient (stronger than weak) annihilation cross sections into e+e-. They could be responsible for the bright 511 keV gamma ray line observed by INTEGRAL from the galactic bulge. Such a new interaction may have important consequences, especially at lower energies. Parity-violation atomic-physics experiments provide strong constraints on such a U boson, if its couplings to quarks and electrons violate parity. With the constraints coming from an unobserved axionlike behaviour of this particle, they privilegiate a pure vector coupling of the U boson to quarks and leptons, unless the corresponding symmetry is broken sufficiently above the electroweak scale.Comment: 6 page

Light spin-1/2 or spin-0 Dark Matter particles

We recall and precise how light spin-0 particles could be acceptable Dark Matter candidates, and extend this analysis to spin-1/2 particles. We evaluate the (rather large) annihilation cross sections required, and show how they may be induced by a new light neutral spin-1 boson U. If this one is vectorially coupled to matter particles, the (spin-1/2 or spin-0) Dark Matter annihilation cross section into e+e- automatically includes a v_dm^2 suppression factor at threshold, as desirable to avoid an excessive production of gamma rays from residual Dark Matter annihilations. We also relate Dark Matter annihilations with production cross sections in e+e- scatterings. Annihilation cross sections of spin-1/2 and spin-0 Dark Matter particles are given by exactly the same expressions. Just as for spin-0, light spin-1/2 Dark Matter particles annihilating into e+e- could be responsible for the bright 511 keV gamma ray line observed by INTEGRAL from the galactic bulge.Comment: 10 page

Mihail Panteleev, Agenty Kominterna

En introduction de l’ouvrage, l’auteur rappelle le renversement radical qui s’est opéré ces deux dernières années en Russie à l’égard de l’image des agents du Komintern. Longtemps présentés en URSS comme des « chevaliers sans peur et sans reproche », ils sont aujourd’hui perçus dans l’opinion publique comme de vulgaires aventuriers solitaires ou d’aveugles fanatiques qui ont allègrement dilapidé l’argent russe sur l’autel de la révolution mondiale, et cela en pleine période de famine générali..

Ulrich Herbert, (Ed.), National Socialist Extermination Policies. Contemporary German Perspectives and Controversies

Prolongeant une série de conférences organisées durant l'hiver 1996/1997 par le Département d'histoire de l'Université Albert-Ludwig de Freiburg, ce recueil d'une dizaine de contributions rédigées par des historiens allemands de la jeune génération, affiche sa volonté de dépasser la controverse, désormais « stérile », des années quatre-vingt entre « intentionnalistes » et « fonctionnalistes ». Fortement marqués par les débats ayant eu lieu en Allemagne lors de la parution de l'ouvrage de Gold..

Ulrich Herbert, (Ed.), National Socialist Extermination Policies. Contemporary German Perspectives and Controversies

Prolongeant une série de conférences organisées durant l'hiver 1996/1997 par le Département d'histoire de l'Université Albert-Ludwig de Freiburg, ce recueil d'une dizaine de contributions rédigées par des historiens allemands de la jeune génération, affiche sa volonté de dépasser la controverse, désormais « stérile », des années quatre-vingt entre « intentionnalistes » et « fonctionnalistes ». Fortement marqués par les débats ayant eu lieu en Allemagne lors de la parution de l'ouvrage de Gold..

1905 de Varsovie à Berlin

RésuméLorsque l’écho de la révolution de 1905 atteignit l’Allemagne, celle-ci était confrontée à une vague de grèves sans précédent, liée à l’aggravation des tensions économiques et sociales. Or, après la révolution de 1905, la plupart des dirigeants révolutionnaires du royaume de Pologne se retrouvèrent en Allemagne qui constituait une base de retraite traditionnelle pour les militants polonais fuyant la répression de la police tsariste.Abstract1905, From Warsaw to Berlin : the Polonization of the German radical leftWhen echoes of the 1905 revolution reached Germany, the country was confronted with an unprecedented wave of strikes linked to increasing economic and social tensions. However, after the 1905 revolution, most of the revolutionary leaders of the Kingdom of Poland were in Germany, a traditional withdrawal position for Polish militants fleeing from the repression of the tsarist police

Real option approach to investments in electricity generating capacity

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000.Includes bibliographical references (leaves 101-105).by Jean-Baptiste Fayet.S.M

Probing Dark force at BES-III/BEPCII

We study an experimental search of a GeV scale vector boson at BES-III/BEPCII. It is responsible for mediating a new U(1)$_d$ interaction, as recently exploited in the context of weakly interacting massive particle dark matter. At low energy $e^+ e^-$ colliders this dark state can be efficiently probed. We discuss the direct productions of this light vector $U$ boson and the decay of this state with BES-III data and its foreseen larger data. In particular, we show that Higgs' strahlung in the dark sector can lead to multilepton signatures, which probe the physics range for kinetic mixing parameter $\epsilon \sim 10^{-4} -10^{-3}$ over a large portion of the parameter space.Comment: 8 pages and 4 figures, version to appear in Phys. Lett.

Semispecific TPPII inhibitor Ala-Ala-Phe-chloromethylketone (AAF-cmk) displays cytotoxic activity by induction of apoptosis, autophagy and protein aggregation in U937 cells

Introduction. The main component of extralysosomal proteolysis is the ubiquitin-proteasome system (UPS), which is supplemented by tripeptidyl peptidase II (TPPII). That system is a target for anticancer strategies by using proteasome inhibitors. Data from several studies on leukemic cells share evidence for the beneficial and potential role of TPPII in cell survivability. Therefore, the aim of this work was to analyze the effect of AAF-cmk, a membrane permeable semi-specific TPPII inhibitor, on human monocytic leukemic cells U937 for translational research. Material and methods. We studied the viability of U937 cells incubated with AAF-cmk using tetrazolium salt reduction assay (MTT) and apoptosis induction by assessing caspase activation by Western blotting and Annexin V binding assays. Transmission electron microscopy (TEM), a gold standard for apoptosis and autophagy detection, was used to assess the ultrastructure of U937 cells. Results. Incubation of cells with AAF-cmk reduced their viability and induced apoptosis by intrinsic pathway. In groups treated with AAF-cmk, activation of caspases 9 and 3 was observed and caspase inhibition by zVDA restored cell viability. TEM revealed the presence of ultrastructural features of apoptosis and authophagy. Moreover, we identified two types of protein aggregates. The first one was found in close proximity to the endoplasmic reticulum (ER) and corresponds to Aggresome-Like Structure (ALIS); however, the second novel type of aggregate was not related to ER elements, but rather to free cytosolic ribosomes. This type did not correspond to the aggresome neither in localization nor the structure, thus we referred these aggregates as ALiSNER (Aggresome-Like Structure Not Associated With the ER). Conclusions. Our results provide novel and important findings about the role of TPPII in protein homeostasis and cell survival. Since semispecific TPPII inhibitor AAF-cmk displays cytotoxic activity against leukemic U937 cells in vitro it can be considered as a potential anticancer agent