Ecal X5 Gif User Manual

This note describes the ECAL Gamma Irradiation Facility (GIF) set-up and how to identify and handle the different parts. It provides an action check list in order to avoid damage to the apparatus and to use it effectively. It describes the set-up in January 2000. A web version which will be updated when needed is available on CMS LAPP team site on LAPP web page at http://wwwlapp.in2p3.fr/cms/GIFUSERMANUAL-X5.html

A new experiment to search for the invisible decay of the orthopositronium

We propose an experiment to search for invisible decays of orthopositronium (o-Ps) with a 90% confidence sensitivity in the branching ratio as low as $10^{-8}$. Evidence for this decay mode would unambigously signal new physics: either the existence of extra--dimensions or fractionally charged particles or new light gauge bosons. The experimental approach and the detector components of the proposed experiment are described.Comment: Based on a talk given at Workshop on Positronium Physics, Zurich, Switzerland, 30-31 May 200

Microstructural dynamics of motor learning and sleep-dependent consolidation: A diffusion imaging study

Memory consolidation can benefit from post-learning sleep, eventually leading to long-term microstructural brain modifications to accommodate new memory representations. Non-invasive diffusion-weighted magnetic resonance imaging (DWI) allows the observation of (micro)structural brain remodeling after time-limited motor learning. Here, we combine conventional diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) that allows modeling dendritic and axonal complexity in gray matter to investigate with improved specificity the microstructural brain mechanisms underlying time- and sleep-dependent motor memory consolidation dynamics. Sixty-one young healthy adults underwent four DWI sessions, two sequential motor trainings, and a night of total sleep deprivation or regular sleep distributed over five days. We observed rapid-motor-learning-related remodeling in occipitoparietal, temporal, and motor-related subcortical regions, reflecting temporary dynamics in learning-related neuronal brain plasticity processes. Sleep-related consolidation seems not to exert a detectable impact on diffusion parameters, at least on the timescale of a few days

Study of the ηπo\eta\pi^o system in the mass range up to 1200 MeV

The reaction $\pi^-p \to \eta\pi^o n$ has been studied with GAMS-2000 spectrometer in the secondary 38 GeV/c $\pi^-$-beam of the IHEP U-70 accelerator. Partial wave analysis of the reaction has been performed in the $\eta\pi^o$ mass range up to 1200 MeV. The $a_0(980)$-meson is seen as a sharp peak in S-wave. The $t$-dependence of $a_0(980)$ production cross section has been studied. Dominant production of the $a_0(980)$ at a small transfer momentum $t$ confirms the hypothesis of Achasov and Shestakov about significant contribution of the $\rho_2$ exchange ($I^GJ^{PC}=1^+2^{--}$) in the mechanism of $a_0(980)$ meson production in $t$-channel of the reaction.Comment: 4 pages, 3 figures, talk given at HADRON'9

Anti-tumor activity of functionalized biomimetic magnetite nanoparticles produced in the presence of MamC protein of Magnetococcus marinus MC-1

Magnetite Nanoparticles (MNPs) find many applications, including biotechnology, as they can be manipulated by an external magnetic field and functionalized with different molecules. Magnetotactic bacteria bio-mineralize magnetosomes (membrane-enveloped magnetites), which are the ideal magnetic particle. However, scaling-up magnetosome production is still challenging, so bio-mimetics, i.e. in vitro magnetite synthesis mediated by magnetosome-associated proteins is being explored. Our group is working with MamC from Magnetococcus marinus MC-1 that controls the morphology and size of the crystals, producing well faceted Biomimetic Magnetic Nanoparticles (BMNPs) of ~40 nm, which are paramagnetic at room and body temperature while having a large magnetic moment per particle under an external magnetic field. These BMNPs were cytocompatible and biocompatible in vivo. BMNPs were functionalized (isothermal adsorption) with a monoclonal antibody (mAb) recognizing the ectodomain of the human Met/HGF receptor (overexpressed in many cancers) and the chemotherapeutic Doxorubicin (DOXO). The functionalized BMNPs present hyperthermia and were stable at physiological pH, while releasing the adsorbed DOXO at acidic pH. mAb functionalization of BMNPs favored their interaction with cells expressing the Met/HGFR and cellular DOXO uptake and toxicity, which was enhanced upon cell exposition to a continuous magnetic field. Real-time cytotoxicity of the BMNPs showed that DOXO-mAb-BMNPs were significantly more toxic than DOXO-BMNPs on Met/HGFR expressing cells, while no differential toxicity was observed on cells not expressing this receptor. When DOXO-BMNPs were injected intravenously in tumor bearing mice and an external magnetic field was applied there, a higher amount of BMNPs accumulated in the tumor and tumor growth was decreased in comparison to mice in which no magnetic field was applied. These BMNPs could thus represent effective nano-carriers for targeted drug delivery and might be combined with hyperthermia to increase efficiency, resulting in a targeted local treatment of tumors with a decrease in the deleterious systemic side effects

Search for an exotic three-body decay of orthopositronium

We report on a direct search for a three-body decay of the orthopositronium into a photon and two penetrating particles, o-Ps -> gamma + X1 + X2. The existence of this decay could explain the discrepancy between the measured and the predicted values of the orthopositronium decay rate. From the analysis of the collected data a single candidate event is found, consistent with the expected background. This allows to set an upper limit on the branching ratio < 4.4 \times 10^{-5} (at the 90% confidence level), for the photon energy in the range from 40 keV < E_gamma< 400 keV and for mass values in the kinematical range 0 gamma + X1 + X2 decay mode as the origin of the discrepancy.Comment: 9 pages, 3 figure

Encoding difficulty promotes postlearning changes in sleep spindle activity during napping

Learning-dependent increases in sleep spindle density have been reported during nocturnal sleep immediately after the learning session. Here, we investigated experience-dependent changes in daytime sleep EEG activity after declarative learning of unrelated word pairs. At weekly intervals, 13 young male volunteers spent three 24 h sessions in the laboratory under carefully controlled homeostatic and circadian conditions. At approximately midday, subjects performed either one of two word-pair learning tasks or a matched nonlearning control task, in a counterbalanced order. The two learning lists differed in the level of concreteness of the words used, resulting in an easier and a more difficult associative encoding condition, as confirmed by performance at immediate cued recall. Subjects were then allowed to sleep for 4 h; afterward, delayed cued recall was tested. Compared with the control condition, sleep EEG spectral activity in the low spindle frequency range and the density of low-frequency sleep spindles (11.25-13.75 Hz) were both significantly increased in the left frontal cortex after the difficult but not after the easy encoding condition. Furthermore, we found positive correlations between these EEG changes during sleep and changes in memory performance between pre-nap and post-nap recall sessions. These results indicate that, like during nocturnal sleep, daytime sleep EEG oscillations including spindle activity are modified after declarative learning of word pairs. Furthermore, we demonstrate here that the nature of the learning material is a determinant factor for sleep-related alterations after declarative learning

A study of the etapipi channel produced in central pp interactions at 450 GeV/c

The reaction pp -> pf (eta pi pi) ps has been studied at 450 GeV/c. There is clear evidence for an a2(1320)pi decay mode of the eta2(1645) and eta2(1870). In addition, there is evidence for an a0(980)pi$ decay mode of both resonances and an f2(1270)eta decay mode of the eta2(1870). No evidence is found for a JPC = 2++ a2(1320)pi wave.Comment: 15 pages, Latex, 4 Figures Branching ratio a2pi /f2 eta correcte