97 research outputs found

    Chirped Pulse Spectrometer Operating at 200 GHz

    Get PDF
    The combination of electronic sources operating at high frequencies and modern microwave instrumentation has enabled the recent development of chirped-pulse spectrometers for the millimetre and THz bands. This type of instrument can operate at high resolution which is particularly suited to gas phase rotational spectroscopy. The construction of a chirped pulse spectrometer operating at 200 GHz is described in detail while attention is paid to the phase stability and the data accumulation over many cycles. Validation using carbonyl sulphide has allowed the detection limit of the instrument to be established as function of the accumulation. A large number of OCS transitions were identified using a 10 GHz chirped pulse and include the 6 most abundant isotopologues, the weakest line corresponding to the fundamental R(17) transition of 16 O 13 C 33 S with a line strength of 4.3 x 10-26 cm-1 /(molec.cm-2). The linearity of the system response for different degrees of data accumulation and transition line strength was confirmed over 4 orders of magnitudes. A simple analysis of the time domain data was demonstrated to provide the line broadening coefficient without the need for conversion by a Fourier transform. Finally, the pulse duration is discussed and optimal values are given for both Doppler limited and collisional regimes

    Terahertz gas phase spectroscopy using a high finesse Fabry-P\'erot cavity

    Full text link
    The achievable instrument sensitivity is a critical parameter for the continued development of THz applications. Techniques such as Cavity-Enhanced Techniques and Cavity Ring Down Spectroscopy have not yet been employed at THz frequency due to the difficulties to construct a high finesse Fabry-P\'erot cavity. Here, we describe such a THz resonator based on a low-loss oversized corrugated waveguide with highly reflective photonic mirrors obtaining a finesse above 3000 around 620 GHz. These components enable a Fabry-Perot THz Absorption Spectrometer with an equivalent interaction length of one kilometer giving access to line intensities as low as 10-27cm- 1/(molecule/cm2) with a S/N ratio of 3. In addition, the intracavity optical power have allowed the Lamb-Dip effect to be studied with a low-power emitter, an absolute frequency accuracy better than 5 kHz can be easily obtained providing an additional solution for rotational spectroscopy.Comment: 7 pages, 4 figure

    Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

    Get PDF
    A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements

    Financial and relational impact of having a boy with posterior urethral valves

    Get PDF
    IntroductionChildhood chronic diseases affect family functioning and well-being. The aim of this study was to measure the impact of caring for a child with PUV, and the factors that most impact the burden of care.Patients and methodWe gave a questionnaire on the familial impact of having a child with posterior urethral valves to all parents of a child included in the CIRCUP trial from 2015 onwards. The questionnaire included questions about the parents' demographics, health, professional, financial and marital status and how these evolved since the child's birth as well as the “impact on family scale” (IOFS), which gives a total score ranging from 15 (no impact) to 60 (maximum impact). We then analyzed both the results of the specific demographic questions as well as the factors which influenced the IOFS score.ResultsWe retrieved answers for 38/51 families (74.5% response rate). The average IOFS score was 23.7 (15–51). We observed that the child's creatinine level had an effect on the IOFS score (p = 0.02), as did the parent's gender (p = 0.008), health status (p = 0.015), being limited in activity since the birth of the child (p = 0.020), being penalized in one's job (p = 0.009), being supported in one's job (p = 0.002), and decreased income (p = 0.004). Out of 38 mother/father binomials, 8/33 (24.2%) declared that they were no longer in the same relationship afterwards.ConclusionIn conclusion, having a boy with PUV significantly impacts families. The risk of parental separation and decrease in revenue is significant. Strategies aiming to decrease these factors should be put in place as soon as possible

    Baryon content in a sample of 91 galaxy clusters selected by the South Pole Telescope at 0.2 <z < 1.25

    Get PDF
    We estimate total mass (M500), intracluster medium (ICM) mass (MICM), and stellar mass (M) in a Sunyaev–Zel’dovich effect (SZE) selected sample of 91 galaxy clusters with masses M500 2.5 × 1014 M and redshift 0.2 < z < 1.25 from the 2500 deg2 South Pole Telescope SPT-SZ survey. The total masses M500 are estimated from the SZE observable, the ICM masses MICM are obtained from the analysis of Chandra X-ray observations, and the stellar masses M are derived by fitting spectral energy distribution templates to Dark Energy Survey griz optical photometry and WISE or Spitzer near-infrared photometry. We study trends in the stellar mass, the ICM mass, the total baryonic mass, and the cold baryonic fraction with cluster halo mass and redshift. We find significant departures from self-similarity in the mass scaling for all quantities, while the redshift trends are all statistically consistent with zero, indicating that the baryon content of clusters at fixed mass has changed remarkably little over the past ≈9 Gyr. We compare our results to the mean baryon fraction (and the stellar mass fraction) in the field, finding that these values lie above (below) those in cluster virial regions in all but the most massive clusters at low redshift. Using a simple model of the matter assembly of clusters from infalling groups with lower masses and from infalling material from the low-density environment or field surrounding the parent haloes, we show that the measured mass trends without strong redshift trends in the stellar mass scaling relation could be explained by a mass and redshift dependent fractional contribution from field material. Similar analyses of the ICM and baryon mass scaling relations provide evidence for the so-called ‘missing baryons’ outside cluster virial regions

    Optical–SZE scaling relations for DES optically selected clusters within the SPT-SZ survey

    Get PDF
    We study the Sunyaev–Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 deg² of the Dark Energy Survey (DES) science verification data, detecting a clear stacked SZE signal down to richness λ ∼ 20. The SZE signature is measured using matched-filtered maps of the 2500 deg2 SPT-SZ survey at the positions of the DES clusters, and the degeneracy between SZE observable and matched-filter size is broken by adopting as priors SZE and optical mass–observable relations that are either calibrated using SPT-selected clusters or through the Arnaud et al. (A10) X-ray analysis. We measure the SPT signal-to-noise ζ–λ relation and two integrated Compton-yY500–λ relations for the DES-selected clusters and compare these to model expectations that account for the SZE–optical centre offset distribution. For clusters with λ > 80, the two SPT-calibrated scaling relations are consistent with the measurements, while for the A10-calibrated relation the measured SZE signal is smaller by a factor of 0.61 ± 0.12 compared to the prediction. For clusters at 20 < λ < 80, the measured SZE signal is smaller by a factor of ∼0.20–0.80 (between 2.3σ and 10σ significance) compared to the prediction, with the SPT-calibrated scaling relations and larger λ clusters showing generally better agreement. We quantify the required corrections to achieve consistency, showing that there is a richness-dependent bias that can be explained by some combination of (1) contamination of the observables and (2) biases in the estimated halo masses. We also discuss particular physical effects associated with these biases, such as contamination of λ from line-of-sight projections or of the SZE observables from point sources, larger offsets in the SZE-optical centring or larger intrinsic scatter in the λ–mass relation at lower richnesses

    The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

    Get PDF
    The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article

    Utilisation de la phytothérapie chez les femmes atteintes de cancer du sein en France. Résultats de l'étude UTOPIa

    No full text
    Les patients atteints du cancer sont de plus en plus nombreux à se tourner vers la phytothérapie, notamment les patientes atteintes de cancer du sein. Pour les cliniciens, ce sujet est devenu inévitable lors de la prise en charge des patientes. L’utilisation des plantes en parallèle des traitements conventionnels n’est pas sans risques, en effet bien que naturelles, leur utilisation n’est pas pour le moins anodine. Les données bibliographiques sur ce sujet sont peu nombreuses en France. Notre étude a pour objectif principal d’identifier auprès de patientes traitées ou ayant été traitées pour un cancer du sein en France, leur consommation de phytothérapie réelle, afin d’analyser les risques d’interaction de celles-ci avec les anticancéreux reçu par les patientes. Les objectifs secondaires sont de décrire les habitudes de prise de phytothérapie des patientes en fonction de leur répartition géographique, leur âge, le stade de leur maladie, leur traitement, la personne ou le média à l’origine de la prise de phytothérapie, et de savoir quelle personne est avertie de cette prise de phytothérapie. Pour ce faire les patientes volontaires devaient répondre à un questionnaire en ligne sur le site www.seintinelles.com

    Régulation du cytosquelette neuronal par les neurofilaments

    No full text
    Nous avons montré que la redistribution des neurofilaments (NF) altère profondément le cytosquelette neuronal : 1) les agrégations de NF caractérisant les souris transgéniques NFH-LacZ et la Sclérose Latérale Amyotrophique s'accompagnent de la co-agrégation de la protéine STOP via une interaction directe STOP/NF (articles 1 & 2). 2) les NF peuvent lier directement la tubuline dépolymérisée, et par conséquent l'absence de NF dans les axones des souris NFH-LacZ permet à toute la tubuline de former des microtubules (MT). Les peptides correspondants à ces sites d'interaction altèrent la polymérisation des MT (article 3 & brevet). 3) Lorsque les NF sont retenus dans le corps cellulaire, ils subissent une forte diminution par un accroissement de leur sensibilité aux protéases, certaines étant co-agrégées avec les NF (article 4). Si ces propriétés peuvent être généralisables aux autres filaments intermédiaires, cela ouvre de nouvelles perspectives sur la dynamique du cytosquelette en général. La production de nouveaux modèles transgéniques (NFH-GFP (article 5), ou GFP-Tubuline) permettront d'aborder ces questions.ANGERS-BU Médecine-Pharmacie (490072105) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF
    corecore