532 research outputs found
Chimie et neutrinos
Cet article illustre la synergie qui existe entre la chimie et la détection des neutrinos, ces particules élémentaires dont l'existence fut confirmée grâce à l'invention des détecteurs à liquide scintillant par des chimistes. Les progrès de ces détecteurs sont issus des recherches des chimistes. La résolution de l'énigme des neutrinos solaires fut rendue possible entre autres par l'obtention d'une extrême pureté radiochimique des différentes cibles utilisées
US-Guided Biopsies: Overarching Principles
Gathering synovial tissue from any swollen joint especially in early arthritis patients is critical for good quality research and to obtain further insight into the pathophysiology of inflammatory joint diseases. Multiplying biopsy sites is a challenge in terms of the techniques needed for each different joint but also in terms of safety and tolerability. It is important to provide the best care especially in very early arthritis patients who have only had the disease for a few months. This review discusses the minimal requirements applying to antiseptic techniques for the operator's hands, patient preparation, local anesthesia, and post-procedure care
Développement de méthodes bio-informatiques pour la découverte de variants codants et non codants dans le cadre des traits sanguins
La santé cardiovasculaire, la fonction immunitaire, l'hémostase et la réponse à d'autres maladies dépendent de l'abondance et des caractéristiques spécifiques des cellules sanguines. Au fil des années, un effort considérable a été fait pour trouver les variants génétiques, les gènes et les mécanismes de régulation impliqués dans la création de ces cellules.
L'inactivation d'un allèle, appelée "perte de fonction" (LoF), est un type de variant codant que nous aimerions associer aux phénotypes sanguins. Comme ces mutations ne peuvent pas être artificiellement induites chez l'humain, pour des raisons éthiques évidentes, nous observons les occurences naturelles de ces pertes de fonction et espérons que la taille des cohortes sera suffisante pour trouver des associations statistiquement significatives.
L'inactivation des deux allèles, appelée "knockout" (KO), peut avoir des conséquences plus fortes qu'une simple perte de fonction. Nous espérons également trouver des KO d'origine naturelle grâce à la taille des cohortes. La combinaison de deux variants LoF différents sur les deux allèles est appelée knockout hétérozygote composé.
Nous nous intéressons également aux variants non codants qui affectent l'expression des gènes impliqués dans l'hématopoïèse. Certains de ces variants créent ou perturbent des sites de liaison des facteurs de transcription (TF), ces protéines qui se lient à des séquences d'ADN spécifiques et régulent l'expression des gènes. Les sites de liaison (TFBS) des facteurs de transcription se trouvent dans les promoteurs des gènes et dans les amplificateurs spécifiques au type cellulaire.
Alors que certaines de ces mutations peuvent être bénignes ou même bénéfiques, la présence d'un LoF ou d'un KO peut être trop nuisible à la survie de l'individu. Les résultats de cette étude sont limités par le biais de survie.
Comparée à une étude d'association pangénomique, cette étude se concentre sur un plus petit nombre de variants génétiques pour augmenter la puissance statistique et offrir une interprétation pour les résultats statistiquement significatifs.
Le programme Trans-Omics for Precision Medicine (TOPMed) recueille et garantit la qualité des 45 000 séquences du génome entier que nous avons utilisées dans cette étude, ainsi que les bilans sanguins correspondants. Grâce à ces données, nous avons pu trouver plusieurs associations connues et nouvelles entre des variants rares et des phénotypes sanguins.Cardiovascular health, immune function, hemostasis and the response to other illnesses depend on the abundance and specific features of blood cells. Over the years, a considerable effort has been made to find which genetic variants, genes and regulatory mechanisms are involved in the creation of these cells.
The inactivation of an allele, called a loss-of-function (LoF), is a type of coding variant we would like to associate with blood phenotypes. For obvious ethical reasons, these mutations cannot be artificially induced in human, so we fall back on natural occurrences and hope that large cohorts will provide enough samples to find statistically significant associations.
The inactivation of both alleles, called a knockout (KO), may have stronger consequences than a simple loss-of-function. We also hope to find naturally occurring knockouts thanks to the size of a large cohort. The combination of two different LoF variants is called a compound heterozygote knockout.
We are also interested in non-coding variants that affect the expression of genes that are involved in hematopoiesis. Some of these variants create or disrupt the binding sites of transcription factors (TF), the proteins that bind to specific DNA sequences and regulate gene expression. Transcription factors binding sites (TFBS) are found in gene promoters and cell type specific enhancers.
While some of these mutations can be benign or even beneficial, the presence of a LoF or KO may be too detrimental for the individual to survive. The results of this study are limited by survival bias.
Compared to a genome-wide association study, this study focuses on a smaller number of genetic variants to increase statistical power and give an interpretation to the statistically significant findings.
The Trans-Omics for Precision Medicine (TOPMed) program collects and ensures the quality of the 45,000 whole-genome sequences we used in this study, as well as the corresponding complete blood counts. Thanks to this raw data, we were able to find several known and novel associations between rare variants and blood phenotypes
Comparison of the CERN-MEMPHYS and T2HK neutrino oscillation experiments
In this talk I compare the physics potential of possible future neutrino
oscillation experiments from CERN to a Mt scale water Cerenkov detector at
Frejus (MEMPHYS) and of the T2HK proposal in Japan, where for the CERN
experiments an SPL Superbeam and a Beta Beam are considered.Comment: Talk given at NOW 2006, 9-16 Sep 2006, Conca Specchiulla, Otranto,
Italy, 3 pages, 2 figure
First Results from Dark Matter Search Experiment in the Nokogiriyama Underground Cell
An experiment to search for hypothetical particle dark matter using cryogenic
thermal detector, or bolometer is ongoing. The bolometer consists of eight
pieces of 21 g LiF absorbers and sensitive NTD germanium thermistors attached
to them and is installed in the Nokogiriyama underground cell which is a
shallow depth site ( m w.e.). We report on the results from the first
running for about ten days using this arrayed bolometer system together with
appropriate shieldings and muon veto counters. From the obtained energy spectra
the exclusion limits for the cross section of the elastic neutralino-proton
scattering are derived under commonly accepted astrophysical assumptions. The
sensitivity for the light neutralino with a mass below 5 GeV is improved by
this work.Comment: 8 pages, Revtex, 4 figure
Quintessence, inflation and baryogenesis from a single pseudo-Nambu-Goldstone boson
We exhibit a model in which a single pseudo-Nambu-Goldstone boson explains
dark energy, inflation and baryogenesis. The model predicts correlated signals
in future collider experiments, WIMP searches, proton decay experiments, dark
energy probes, and the PLANCK satellite CMB measurements.Comment: 16 pages, 3 color figure
MEMPHYS:A large scale water Cerenkov detector at Fr\'ejus
A water \v{C}erenkov detector project, of megaton scale, to be installed in
the Fr\'ejus underground site and dedicated to nucleon decay, neutrinos from
supernovae, solar and atmospheric neutrinos, as well as neutrinos from a
super-beam and/or a beta-beam coming from CERN, is presented and compared with
competitor projects in Japan and in the USA. The performances of the European
project are discussed, including the possibility to measure the mixing angle
and the CP-violating phase .Comment: 1+33 pages, 14 figures, Expression of Interest of MEMPHYS projec
Ultrasound-Guided Synovial Biopsies of Wrists, Metacarpophalangeal, Metatarsophalangeal, Interphalangeal Joints, and Tendon Sheaths
Ultrasound-guided synovial biopsy (UGSB) is a minimally-invasive procedure which allows quality synovial tissue retrieval. In this article, we will discuss overarching principles of the procedure performed in wrists, metacarpophalangeal (MCP), metatarsophalangeal (MTP), interphalangeal joints (IP), and tendon sheaths, including basic sonoanatomy, entry site and biopsy technique, as well as special considerations for each structure whenever relevant
S-35 Beta Irradiation of a Tin Strip in a State of Superconducting Geometrical Metastability
We report the first energy loss spectrum obtained with a geometrically
metastable type I superconducting tin strip irradiated by the beta-emission of
S-35. (Nucl. Instr. Meth. A, in press)Comment: Compressed PostScript (filename.ps.Z), 9 pages, 2 figure
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