M2000 : an astrometric catalog in the Bordeaux Carte du Ciel zone +11 degrees < {delta} < +18 degrees

During four years, systematic observations have been conducted in drift scan mode with the Bordeaux automated meridian circle in the declination band [+11 ; +18]. The resulting astrometric catalog includes about 2 300 000 stars down to the magnitude limit V_M=16.3. Nearly all stars (96%) have been observed at least 6 times, the catalog being complete down to V_M=15.4. The median internal standard error in position is about 35 mas in the V_M magnitude range [11 ; 15], which degrades to about 50 mas when the faintest stars are considered. M2000 provides also one band photometry with a median internal standard error of 0.04 mag. Comparisons with the Hipparcos and bright part of Tycho-2 catalogs have enabled to estimate external errors in position to be lower than 40 mas. In this zone and at epoch 1998, the faint part of Tycho-2 is found to have an accuracy of 116 mas in alpha instead of 82 mas deduced from the model-based standard errors given in the catalog.Comment: The catalogue can be fetched directly from: ftp://cdsarc.u-strasbg.fr/cats/I/272 or queried from: http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=I/272 More information at : http://www.observ.u-bordeaux.fr/~soubiran/m2000.ht

CLT in Functional Linear Regression Models

International audienceWe propose in this work to derive a CLT in the functional linear regression model to get confidence sets for prediction based on functional linear regression. The main difficulty is due to the fact that estimation of the functional parameter leads to a kind of ill-posed inverse problem. We consider estimators that belong to a large class of regularizing methods and we first show that, contrary to the multivariate case, it is not possible to state a CLT in the topology of the considered functional space. However, we show that we can get a CLT for the weak topology under mild hypotheses and in particular without assuming any strong assumptions on the decay of the eigenvalues of the covariance operator. Rates of convergence depend on the smoothness of the functional coefficient and on the point in which the prediction is made

S-100 protein positive cells in nasopharyngeal carcinoma (NPC): absence of prognostic significance. A clinicopathological and immunohistochemical study of 40 cases

An immunohistochemical study of S-100 protein in 43 nasopharyngeal carcinomas (NPC) of known clinical evolution (33 primary and 10 metastatic) is presented. Sixty per cent of primary site cases as well as all metastatic forms showed S-100 protein positive cells intermingled with tumour cells. These S-100 positive elements were identified as Langerhans cells. No significant differences were found when correlating S-100 protein positivity and histological NPC variants, neither in age nor in sex of patients. Statistical analysis failed to demonstrate any positive correlation between S-100 protein reactivity and clinical survival

Development and characterization of the control assembly system for the large 2400MWth Generation IV gas-cooled fast reactor

International audienceThe present paper is related to the design and neutronic characterization of the principal control assemblysystem for the reference large (2400 MWth) Generation IV gas-cooled fast reactor (GFR), which makesuse of ceramic–ceramic (CERCER) plate-type fuel-elements with (U–Pu) carbide fuel contained within aSiC inert matrix. For the neutronic calculations, the deterministic code system ERANOS-2.0 has been used,in association with a full core model including a European fast reactor (EFR)-type pattern for the controlassemblies as a starting point. More specifically, the core contains a total of 33 control (control systemdevice: CSD) and safety (diverse safety device: DSD) assemblies implemented in three banks. In thedesign of the new control assembly system, particular attention was given to the heat generation withinthe assemblies, so that both neutronic and thermal–hydraulic constraints could be appropriatelyaccounted for. The thermal–hydraulic calculations have been performed with the code COPERNIC, significantcoolant mass flow rates being found necessary to maintain acceptable cladding temperatures of theabsorber pins.Complementary to the design study, neutronic investigations have been performed to assess theimpact of the control assemblies in the GFR core in greater detail (rod interactions, shift of the flux, peakingfactors, etc.). Thus, considerable shadowing effects have been observed between the first bank and thesafety bank, as also between individual assemblies within the first bank. Large anti-shadowing effectsalso occur, the most prominent being that between the two CSD banks, where the total assembly worthis almost doubled in comparison to the sum of the individual values. Additional investigations have beenperformed and, in this context, it has been found that computation of the first-order eigenvalue and theeigenvalue separation is a robust tool to anticipate control assembly interactions in a large fast-spectrumcore. One interesting finding is that the interactions are lower when one of the control assembly banks islocated at a radial position corresponding to the minimum in the first-order eigenvalue (at approximatelyhalf the core radius).An important aspect of the design optimization process has been to obtain a low heterogeneity effectfor the control assembly worth. This was achieved by applying a methodology based on reactivity equivalence,with the optimization goal set at minimizing the shadowing effects between the absorber pins aswell as the self-shielding within the absorber pins. A relatively low reduction of aproximatively 13percent was obtained asthe heterogeneity effect for the control assembly worth, the corresponding value in the case of Superphénixbeing significantly higher, viz. about 20 percent