Studies of the decay Bs0→Ds∓K±B^{0}_{s} \to D^{\mp}_sK^{\pm}

The decay mode $B^{0}_{s} \to D^{\mp}_s K^{\pm}$ allows for one of the theoretically cleanest time dependent measurements of the CKM angle $\gamma$. This contribution reports the world best branching fraction of this decay relative to the Cabibbo--favoured mode $B^{0}_{s} \to D_{s}^{-}\pi^{+}$ based on data sample of 0.37 $\rm fb^{-1}$ proton--proton collisions at $\sqrt{s} = 7$ TeV collected with the LHCb detector in 2011, resulting in BR(\BsDK) = (1.90 \pm 0.12^{stat} \pm {{0.13^{syst}}^{+0.12}_{-0.14}}^{f_{s}/f_{d}})\times 10^{-4}.Comment: 4 pages, 3 figures, presented at Recontres de Moriond EW 201

Search for New Physics in SHiP and at future colliders

SHiP is a newly proposed fixed-target experiment at the CERN SPS with the aim of searching for hidden particles that interact very weakly with SM particles. The work presented in this document investigates SHiP's physics reach in the parameter space of the Neutrino Minimal Standard Model ($\nu$MSM), which is a theory that could solve most problems left open by the Standard Model with sterile neutrinos. A model introducing an extra $U(1)$ symmetry in the hidden sector, providing a natural candidate for dark matter, is also explored. This work shows that the SHiP experiment can improve by several orders of magnitude the sensitivity to Heavy Neutral Leptons below 2 GeV, scanning a large part of the parameter space below the $B$ meson mass. The remainder of the $\nu$MSM parameter space, dominated by right-handed neutrinos with masses above 2 GeV, can be explored at a future $e^+e^-$ collider. Similarly, SHiP can greatly improve present constraints on $U(1)$ dark photons.Comment: Proceedings for the INFIERI 2014 schoo

Analysis and correction of the magnetic field effects in the Hybrid Photo-Detectors of the RICH2 Ring Imaging Cherenkov detector of LHCb

The Ring Imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN are equipped with Hybrid Photo-Detectors. These vacuum photo-detectors are affected by the stray magnetic field of the LHCb magnet, which degrades their imaging properties. This effect increases the error on the Cherenkov angle measurement and would reduce the particle identification capabilities of LHCb. A system has been developed for the RICH2 Ring Imaging Cherenkov detector to perform a detailed characterisation of the magnetic distortion effects. It is described, along with the methods implemented to correct for these effects, restoring the optimal resolution.Comment: 16 pages, 11 figure

First measurement of the fragmentation fraction ratio fs/fd with tree level hadronic decays at 7 TeV pp collisions

Merk, M.H.M. [Promotor]Tuning, N. [Copromotor

Application of large area SiPMs for the readout of a plastic scintillator based timing detector

In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6 cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM anode readout ASIC (MUSIC R1) based on a novel low input impedance current conveyor has been used to read out and amplify SiPMs independently and sum the signals at the end. Prospects for applications in large-scale particle physics detectors with timing resolution below 100 ps are provided in light of the results

Application of large area SiPMs for the readout of a plastic scintillator based timing detector

In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6 cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM anode readout ASIC (MUSIC R1) based on a novel low input impedance current conveyor has been used to read out and amplify SiPMs independently and sum the signals at the end. Prospects for applications in large-scale particle physics detectors with timing resolution below 100 ps are provided in light of the results

Design and Validation of a Software Tool to Improve Methods for Creating Custom Analyses of Motion Capture Data: Analysis of Quarterback Throwing Biomechanics Based Upon a Coaching Perspective

The goal of this work was to develop a software platform to synchronize and facilitate the way in which researchers perform custom analysis of motion capture (MOCAP) data. The software was developed using Python and contains both frontend and backend tools to accomplish this goal. It includes a user interface which allows users to: access MOCAP trial data, view corresponding video files, display results of custom-programmed analyses, bulk analyze data, compile and save results, and generate PDF reports over the analysis. The backend contains a set of tools which: allow for easy access of MOCAP data stored in the C3D file format, establish a framework which future custom MOCAP analysis can follow, and efficiently stores results in a platform-independent, serialized, data file which can be opened at a later time for additional statistical processing of results. To validate the software platform a human subjects research study was designed to analyze quarterback (QB) throwing biomechanics in a manner consistent with what football coaches are teaching to players. Interviews were conducted with eight coaches from the middle school and high school levels to establish the common “coaching points” being taught to players. A custom marker-set was designed for the study, and fifteen QBs (ages 12-18, mean 15.1) were brought in for data capture. Subjects were asked to perform three throws (hitch, corner, comeback), each using a different foot pattern (quick game, 3-step drop, rollout), to each side of the field. Throwing data was captured using a twelve-camera Vicon Motion Capture System (Vantage V16), and four AMTI force plates (OR6-6-1000). Custom analyses were programmed to examine the coaching points from the interviews: elbow flexion, balance throughout the throwing motion, release time, release orientation, analysis of the stride, accuracy of the throw, and the hip leading angle were the points of interest. Additional analyses, from both the QB work and a separate MOCAP study, were programmed by undergraduate researchers in the lab, to verify the use of the software’s usefulness to multiple users and applications

Evaluación de los hifomicetos acuáticos como bioindicadores de calidad ambiental en el río Chirgua (Bejuma, Venezuela)

Actualmente la evaluación del recurso hídrico, emplea bioindicadores como sistemas adicionales de diagnóstico, ya que estos indican perturbaciones antropogénicas. Los hifomicetos acuáticos al ser parte de la cadena trófica de los ecosistemas acuáticos, son indicadores de calidad del agua, al variar su presencia y concentración de conidios en función a la afectación ambiental. Por lo tanto esta investigación evaluó su rol bioindicador de calidad ambiental en el Río Chirgua en Venezuela. Mensualmente durante el 2011, en dos zonas: 1) cabecera (sin afectación) y 2) zona aguas abajo (con afectación), se determinaron parámetros físico-químicos (O2, conductividad, pH, temperatura y sólidos totales), nutrientes (SO4-2, PO4-3, NO2-2 y NO3-3), coliformes (totales y fecales) y hifomicetos acuáticos (riqueza y conidios/mL). Se registraron 44 especies, 42 (20 exclusivas) en la zona 1 y 24 (2 exclusivas) en la zona 2. En el sector afectado disminuyó el número de especies y concentración de conidios en función del incremento de coliformes (totales y fecales), en comparación con la zona no afectada. Las especies sensibles a la perturbación ambiental por coliformes fueron: Brachiosphaera tropicalis, Camposporium antenatum, Campylospora filicladia, Campylospora parvula, Clavatospora tentacula, Clavatospora stellata, Culicidospora gravida, Diplocladiella scalaroides, Flabellospora acuminata, Helicomyces colligatus, Helicomyces sp., Helicomyces torquatus, Phalangispora constricta, Tetracladium marchalianum y Triscelophorus monosporus, mientras que las tolerantes fueron: Alatospora acuminata, Campylospora chaetocladia, Flabellospora crassa, Isthmotricladia gombakiensis, Tetraploa cf. aristata y Triscelophorus acuminatus.At present, the evaluation of water resources uses bioindicators, such as additional diagnostic systems, because they indicate anthropogenic disturbances. Aquatic hyphomycetes,  part of the trophic chain of aquatic ecosystems, are indicators of water quality through their varying  presence and concentration of conidia based on environmental disturbance; therefore, this research assessed their bioindicator role for environmental quality in the Chirgua River in Venezuela. In 2011 in two areas: 1) Headwaters (unaffected) and 2) downstream area (affected), physico-chemical parameters (O2, conductivity, pH, temperature and total solids) and nutrients were determined weekly (SO4-2, PO4-3, NO2-2 and NO3-3), along with coliforms (total and fecal) and water hyphomycetes (number of species and conidia/mL). We identified a total of 44 species, 42 (20 exclusive) in zone 1 and 24 (2 exclusive) in zone 2. In the affected sector, the number of species and conidia/mL of the coliforms (total and fecal) decreased, as compared to the unaffected zone. Sensitive species to environmental disturbance for coliforms included Brachiosphaera tropicalis, Camposporium antenatum, Campylospora filicladia, Campylospora parvula, Clavatospora tentacula, Clavatospora stellata, Culicidospora gravida, Diplocladiella scalaroides, Flabellospora acuminata, Helicomyces colligatus, Helicomyces sp., Helicomyces torquatus, Phalangispora constricta, Tetracladium marchalianum and Triscelophorus monosporus, while tolerant species included Alatospora acuminata, Campylospora chaetocladia, Flabellospora crassa, Isthmotricladia gombakiensis, Tetraploa cf. Aristata and Triscelophorus acuminatus

po 080 v atpase g1 expression in human glioma stem cells correlates with erk activation

Introduction The vacuolar ATPase (V-ATPase) is a multisubunit proton pump acting in multiple processes in eukaryotic cells. Alteration of V-ATPase activity is associated to a wide range of human diseases including cancer. We have recently showed that V-ATPase expression has a central role in glioma stem cells (GSC) maintenance. Therefore we aimed to get insights into the signalling associated with V-ATPase expression in GSC. Material and methods Signalling survey was performed using phospho-specific antibodies and the Cancer 10-pathway Reporter Luciferase Kit. GSC were treated with Ammonium chloride (NH4Cl) (10–50 mM), Bafilomycin A1 (BafA1) (10 nM) and the ERK inhibitor PD98059 (10 uM) Cell Invasion through collagen matrix and sphere formation were evaluated after 48 hour of drugs treatment, while cell cycle, apoptosis and ROS production were evaluated by flow cytometry after 24 hour. Mitochondrial depolarization and activity were evaluated by flow cytometry after TMRE staining and western blot, respectively. Autophagy was analysed by western blot using an antibody to p62. All experiments were performed using primary GSC cultures with high and low levels of V-ATPase G1 subunit (V1G1HIGH and V1G1LOW; n=3 each). Results and discussions The MAPK/Erk pathway was significantly upregulated in V1G1HIGH GSC and V-ATPase impairment by BafA1 reduced Erk phosphorylation, besides decreasing lysosomal acidification. Therefore we investigated if this effect was specific for the pump activity or if it was related to lysosomal dysfunction or to MAPK/Erk signalling. The comparison of the three drugs revealed that only BafA1 treatment induced cells death, reduced clonogenicity and invasion ability and decreased the phosphorylation level of proteins involved in proliferation and pro-apoptotic processes. Moreover BafA1 was the only drug that, at not lethal dosage, impaired cell cycle progression. This effect was associated with an increase in ROS production and mitochondrial depolarization and using a ROS inhibitor the effects of BafA1 were reverted. Conclusion Taken together these results indicate that the V-ATPase play a central role in GSC viability that goes beyond lysosomal activity or ERK phosphorylation. Further studies are needed to elucidate the roles of the proton pump in GSC and to target this molecule for innovative anti-cancer strategies