An original interferometric study of NGC 1068 with VISIR BURST mode images

We present 12.8 microns images of the core of NGC 1068 obtained with the BURST mode of the VLT/VISIR. We trace structures under the diffraction limit of one UT and we investigate the link between dust in the vicinity of the central engine of NGC 1068, recently resolved by interferometry with MIDI, and more extended structures. This step is mandatory for a multi-scale understanding of the sources of mid-infrared emission in AGNs. A speckle processing of VISIR BURST mode images was performed to extract very low spatial-frequency visibilities, first considering the full field of VISIR BURST mode images and then limiting it to the mask used for the acquisition of MIDI data. Extracted visibilities are reproduced with a multi-component model. We identify two major sources of emission: one compact < 85 mas, associated with the dusty torus, and an elliptical one, (< 140) mas x 1187 mas at P.A.=-4 degrees from N to E. This is consistent with previous deconvolution processes. The combination with MIDI data reveals the close environment of the dusty torus to contribute to about 83 percent of the MIR flux seen by MIDI. This strong contribution has to be considered in modeling long baseline interferometric data. It must be related to the NS elongated component which is thought to originate from individually unresolved dusty clouds and is located inside the ionization cone. Low temperatures of the dusty torus are not challenged, emphasizing the scenarios of clumpy torus.Comment: 10 pages, 7 figures, accepted for publication in A&

Trans-active factors controlling the IL-2 gene in adult human T-cell subsets

IL-2 secretion in total or subsets of PHA/PMA-stimulated PBMC-derived human T-lymphocytes was monitored and found to be largely due to CD4+CD8− cells. The presence and functional state of transcription factors (TF) was assessed by protein-DNA interaction assays and functional transactivation experiments in the Xenopts oocyte system, modulating IL-2 transcription by injection of proteins. The results reveal that CD4+CD8− cells contain both, functional silencer in their resting, and positive TF in their activated states while the CD4+CD8− group contains only non-functional positive TF. This demonstrates that the on/off switch of IL-2 transcription is based on the same mechanism in primary T-lymphocytes of mouse spleen and in peripheral human CD4+CD8− cells

Nonequilibrium Reweighting on the Driven Diffusive Lattice Gas

The nonequilibrium reweighting technique, which was recently developed by the present authors, is used for the study of the nonequilibrium steady states. The renewed formulation of the nonequlibrium reweighting enables us to use the very efficient multi-spin coding. We apply the nonequilibrium reweighting to the driven diffusive lattice gas model. Combining with the dynamical finite-size scaling theory, we estimate the critical temperature Tc and the dynamical exponent z. We also argue that this technique has an interesting feature that enables explicit calculation of derivatives of thermodynamic quantities without resorting to numerical differences.Comment: Accepted for publication in J. Phys. A (Lett.

Measuring memetic algorithm performance on image fingerprints dataset

Personal identification has become one of the most important terms in our society regarding access control, crime and forensic identification, banking and also computer system. The fingerprint is the most used biometric feature caused by its unique, universality and stability. The fingerprint is widely used as a security feature for forensic recognition, building access, automatic teller machine (ATM) authentication or payment. Fingerprint recognition could be grouped in two various forms, verification and identification. Verification compares one on one fingerprint data. Identification is matching input fingerprint with data that saved in the database. In this paper, we measure the performance of the memetic algorithm to process the image fingerprints dataset. Before we run this algorithm, we divide our fingerprints into four groups according to its characteristics and make 15 specimens of data, do four partial tests and at the last of work we measure all computation time

Quelle régulation pour l’arrêt d’un protocole de recherche clinique de thérapie génique somatique ? État des lieux auprès des cliniciens-chercheurs européens

Depuis 2002, le débat sur les risques associés à la thérapie génique est initié suite à l’annonce que deux enfants inclus dans un essai thérapeutique impliquant une thérapie génique ont développé des effets indésirables important. En Janvier 2005, le débat sur les risques reprit suite à l’interruption du protocole sur les enfants bulle du Pr Fischer à l’hôpital Necker de Paris. Nous avons donc étudié le processus impliqué ainsi que la réflexion éthique associée aux décisions d’arrêt de protocole de recherche. Notre travail a été mené par une équipe pluridisciplinaire combinant chercheurs en santé, généticiens et éthiciens. Nous avons étudié la participation des chercheurs, des patients, des institutions officielles, des comités d’éthique ainsi que des associations de patients dans le processus de décision d’interruption d’un protocole de recherche.Nous avons également analysé les critères jugés les plus pertinents dans l’arrêt d’un protocole de recherche. Enfin nous avons analysé le point de vue des personnes directement impliquées dans la thérapie génique au moyen d’un questionnaire. Toutes les personnes contactées ont présenté un poster de recherche au congrès de la Société Européenne de Thérapie Génique. 62 personnes d’autant d’équipes de recherche différentes, de 17 pays, sur les 350 contactés ont répondu. Selon eux, la décision d’arrêt d’un protocole de recherche doit être prise suite à une consultation des chercheurs, des patients, du ministère de tutelle, d’une agence nationale de régulation ou d’un comité d’éthique ; la légitimité étant accordée à des décisions prises en commun par les chercheurs, les patients et les comités d’éthique. Les incidents sérieux et de façon plus surprenante, les incidents moins graves sont jugés comme étant des critères suffisants pour interrompre un essai. Nous avons fini par analyser les conséquences éthiques, telles que balance bénéfice/risque, processus de régulation ou responsabilité, de ces critères sur l’arrêt d’un protocole de recherche.In 2002, the debate on the risks of gene therapy was initiated following the annoucement that two children included in a clinical trial developed serious adverse effects. In January 2005, the debate was reignited following the interruption of the “bubble kids protocol” at the Hôpital Necker in Paris. We have thus investigated the ethical stakes involved in decisions to stop protocols. This work was carried out by a multidisciplinary team combining ethics researchers and geneticists. We studied the specific participation of researchers, patients, official institution, ethics committees and patient associations in the processes that can lead to an interruption of trial.We also analysed the criterion judged most relevant for halting a trial. Finally, we analyzed the perspective of the actors implicated directly in the provision of gene therapy, by means of a questionnaire. All the individuals contacted had presented a scientific poster at the European Society of Gene Therapy. 62 out of 350 persons, from 17 countries, responded to our questionnaire. According to these respondants, decisions to stop a trial should be taken after consultation with researchers, patients, the ministry, national agencies or ethics committees. Legitimacy was accorded to joint decision-making by researchers, patients and committees. Serious incidents, and surprisingly less serious incidents, clearly emerge as criterion for stopping a trial. We conclude by analyzing the ethical consequences, such as risk/benefit ratios, regulatory processes and responsibility, associated with these criterions and decisions to stop a trial

Characterization of Serum Phospholipase A2 Activity in Three Diverse Species of West African Crocodiles

Secretory phospholipase A2, an enzyme that exhibits substantial immunological activity, was measured in the serum of three species of diverse West African crocodiles. Incubation of different volumes of crocodile serum with bacteria labeled with a fluorescent fatty acid in the sn-2 position of membrane lipids resulted in a volume-dependent liberation of fluorescent probe. Serum from the Nile crocodile (Crocodylus niloticus) exhibited slightly higher activity than that of the slender-snouted crocodile (Mecistops cataphractus) and the African dwarf crocodile (Osteolaemus tetraspis). Product formation was inhibited by BPB, a specific PLA2 inhibitor, confirming that the activity was a direct result of the presence of serum PLA2. Kinetic analysis showed that C. niloticus serum produced product more rapidly than M. cataphractus or O. tetraspis. Serum from all three species exhibited temperature-dependent PLA2 activities but with slightly different thermal profiles. All three crocodilian species showed high levels of activity against eight different species of bacteria

One pot Pd(OAc)2-catalysed 2,5-diarylation of imidazoles derivatives

International audienceThe regioselective 2- or 5-arylation of imidazole derivatives with aryl halides using palladium catalysts has been described in recent years; whereas the arylation at both C2 and C5 carbons of imidazoles in high yields has not been performed. We found conditions allowing the access to these 2,5-diarylimidazoles via a one pot reaction. The choice of the base was found to be crucial to obtain these products in high yields. Using CsOAc as the base, DMA as the solvent and only 2 mol % of the phosphine-free Pd(OAc)2 the catalyst, the target 2,5-diarylated imidazoles were obtained in moderate to good yields with a wide variety of aryl bromides. Substituents such as fluoro, trifluoromethyl, formyl, acetyl, propionyl, ester, nitro or nitrile on the aryl bromide were tolerated. Sterically congested aryl bromides or heteroaryl bromides can also be employed. Surprisingly the nature of the substituent at position 1 on the imidazole derivative exhibits a huge influence on the reaction

Multiple achromatic plumage ornaments signal to multiple receivers

We investigated whether achromatic plumage traits can act as multiple ornaments in an Arctic-breeding passerine, the snow bunting (Plectrophenax nivalis). Specifically, we examine whether multiple ornaments are providing multiple differing messages, are redundant, are unreliable signals of male quality, or are aimed at different receivers. We measured plumage reflectance and pigmentation patterns made conspicuous during male inter-and intrasexual displays that advertise different plumage regions. Our results indicate that although several aspects of male plumage may have redundant messages, different body regions appear aimed at different receivers. The wings of males-displayed primarily toward females during courtship-appear to indicate a pair\u27s future reproductive performance. Conversely, melanin-based plumage reflectance displayed during intrasexual threat displays provides information on territory features and a male\u27s capacity to defend it (i.e., territory size, territory quality, testosterone levels). Taken together, we suggest that snow buntings have multiple ornaments that provide information of differential importance in inter-versus intrasexual communication. This study demonstrates that achromatic plumage traits can serve in complex communication. © 2012 The Author

Bayesian model selection for the glacial-interglacial cycle

A prevailing viewpoint in paleoclimate science is that a single paleoclimate record contains insufficient information to discriminate between typical competing explanatory models. Here we show that by using SMC 2 (sequential Monte Carlo squared) combined with novel Brownian bridge type proposals for the state trajectories, it is possible to estimate Bayes factors to sufficient accuracy to be able to select between competing models, even with relatively short time series. The results show that Monte Carlo methodology and computer power have now advanced to the point where a full Bayesian analysis for a wide class of conceptual climate models is now possible. The results also highlight a problem with estimating the chronology of the climate record prior to further statistical analysis, a practice which is common in paleoclimate science. Using two datasets based on the same record but with different estimated chronologies, results in conflicting conclusions about the importance of the astronomical forcing on the glacial cycle, and about the internal dynamics generating the glacial cycle, even though the difference between the two estimated chronologies is consistent with dating uncertainty. This highlights a need for chronology estimation and other inferential questions to be addressed in a joint statistical procedure