1,385 research outputs found

    Inertial waves and modes excited by the libration of a rotating cube

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    We report experimental measurements of the flow in a cubic container submitted to a longitudinal libration, i.e. a rotation modulated in time. Velocity fields in a vertical and a horizontal plane are measured in the librating frame using a corotating particle image velocimetry system. When the libration frequency σ0\sigma_0 is smaller than twice the mean rotation rate Ω0\Omega_0, inertial waves can propagate in the interior of the fluid. At arbitrary excitation frequencies σ0<2Ω0\sigma_0<2\Omega_0, the oscillating flow shows two contributions: (i) a basic flow induced by the libration motion, and (ii) inertial wave beams propagating obliquely upward and downward from the horizontal edges of the cube. In addition to these two contributions, inertial modes may also be excited at some specific resonant frequencies. We characterize in particular the resonance of the mode of lowest order compatible with the symmetries of the forcing, noted [2,1,+]. By comparing the measured flow fields to the expected inviscid inertial modes computed numerically [L.R.M. Maas, Fluid Dyn. Res. \textbf{33}, 373 (2003)], we show that only a subset of inertial modes, matching the symmetries of the forcing, can be excited by the libration.Comment: Phys. Fluids (in press

    Ménard de La Groye et la question religieuse à l&#039;Assemblée nationale (1789-1791)

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    Un affrontement religieux feutré

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    A kinematical analysis of NGC 2992

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    We present long slit spectroscopy for the [OIII] and Hα\alpha wavelength ranges along nine different position angles for the Sa Seyfert 1.9 galaxy NGC 2992. Double profiles are present in several regions, suggesting that the gas is not simply following galaxy rotation. A simple kinematical model, which takes into account circular rotation together with a constant radial outflow, seems to be a good approximation to account for the observed kinematics.Comment: Accepted for publication in Astronomy & Astrophysic

    Optical-NIR spectroscopy of the puzzling gamma-ray source 3FGL 1603.9-4903/PMN J1603-4904 with X-shooter

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    The Fermi/LAT instrument has detected about two thousands Extragalactic High Energy (E > 100 MeV) gamma-ray sources. One of the brightest is 3FGL 1603.9-4903, associated to the radio source PMN J1603-4904. Its nature is not yet clear, it could be either a very peculiar BL Lac or a CSO (Compact Symmetric Object) radio source, considered as the early stage of a radio galaxy. The latter, if confirmed, would be the first detection in gamma-rays for this class of objects. Recently a redshift z=0.18 +/- 0.01 has been claimed on the basis of the detection of a single X-ray line at 5.44 +/- 0.05 keV interpreted as a 6.4 keV (rest frame) fluorescent line. We aim to investigate the nature of 3FGL 1603.9-4903/PMN J1603-4904 using optical to NIR spectroscopy. We observed PMN J1603-4904 with the UV-NIR VLT/X-shooter spectrograph for two hours. We extracted spectra in the VIS and NIR range that we calibrated in flux and corrected for telluric absorption and we systematically searched for absorption and emission features. The source was detected starting from ~6300 Ang down to 24000 Ang with an intensity comparable to the one of its 2MASS counterpart and a mostly featureless spectrum. The continuum lacks absorption features and thus is non-stellar in origin and likely non-thermal. On top of this spectrum we detected three emission lines that we interpret as the Halpha-[NII] complex, the [SII] 6716,6731 doublet and the [SIII] 9530 line, obtaining a redshift estimate of z= 0.2321 +/- 0.0004. The equivalent width of the Halpha-[NII] complex implies that PMN J1603-4904 does not follow the observational definition of BL Lac, the line ratios suggest that a LINER/Seyfert nucleus is powering the emission. This new redshift measurement implies that the X-ray line previously detected should be interpreted as a 6.7 keV line which is very peculiar.Comment: Published in Astronomy and Astrophysic

    Assessing the Health Impact of Water Quality Interventions in Low-Income Settings: Concerns Associated with Blinded Trials and the Need for Objective Outcomes.

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    BACKGROUND: A dramatic disparity between the results of blinded versus open trial designs has raised questions about the effectiveness of water quality interventions and other environmental interventions to prevent diarrhea, a leading killer of young children in low-income countries. OBJECTIVES: We summarize the results of blinded versus open trials of water quality interventions, describe evidence from a recent placebo-controlled trial in India suggesting that control households were put at risk from their participation, and suggest alternatives to blinded trials that could resolve continued uncertainty about the magnitude of the protective effect of water, sanitation, and hygiene (WASH) interventions without presenting ethical questions. DISCUSSION: Concerns about reporting bias in open trial designs continue to cause uncertainty about the effectiveness of WASH interventions. However, evidence suggests that despite instructions to the contrary, placebos may encourage control group participants in blinded trials to cease practicing traditional water treatment practices in the mistaken belief that they are protected by an active intervention. Although objective outcomes such as pathogen incrimination, seroconversion, biomarkers, and anthropometry can be helpful, these are often costly, nonspecific, and unsuitable for evaluating programmatic interventions. CONCLUSIONS: Unless researchers can be assured that a placebo will not cause those in a control group to change their behavior in a manner that increases their risk, it is incumbent on researchers to use alternatives. Validated objective measures are needed for assessing the health impact of WASH interventions that are reliable, affordable, and suitable both for research and program evaluation. CITATION: Clasen T, Boisson S. 2016. Assessing the health impact of water quality interventions in low-income settings: concerns associated with blinded trials and the need for objective outcomes. Environ Health Perspect 124:886-889; http://dx.doi.org/10.1289/ehp.1510532

    NicodĂ©misme et RĂ©vocation de l’édit de Nantes

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    Outre la conversion, l’opiniĂątretĂ© et l’exil, il existe un quatriĂšme comportement que l’on peut observer parmi les Nouveaux Convertis (NC) aprĂšs la RĂ©vocation de l’édit de Nantes : le nicodĂ©misme, c’est-Ă -dire le fait de cacher ses vĂ©ritables opinions et d’adopter un catholicisme de façade tout en restant intĂ©rieurement rĂ©formĂ©. Cette attitude a dĂ©jĂ  Ă©tĂ© dĂ©noncĂ©e par Calvin dans plusieurs ouvrages, comme en 1544 dans son Excuse Ă  Messieurs les NicodĂ©mites ou quinze ans plus tard dans le Petit traictĂ© monstrant que c’est que doit faire un homme fidĂšle cognoissant la vĂ©ritĂ© de l’Évangile, contestant mĂȘme le terme de « nicodĂ©mites » dans la mesure oĂč NicodĂšme a aussi soutenu le Christ contre tous et a mĂȘme enseveli son corps avec l’aide de Joseph d’Arimathie . Cette dĂ©nonciation est reprise au moment de la RĂ©vocation de l’édit de Nantes par les pasteurs du Refuge dans des ouvrages de controverse ou des lettres pastorales. Le terme de nicodĂ©mite est alors peu utilisĂ© dans la mesure oĂč, comme Calvin, des pasteurs tels Jacques Basnage trouvent le mot inadĂ©quat mais dĂ©noncent les comportements de ces NC qu’ils accusent d’avoir reniĂ© Dieu en abandonnant leur confession . Les causes de leurs chutes, selon ces mĂȘmes pasteurs, sont Ă  la fois les persĂ©cutions subies, les moyens mis en Ɠuvre par l’Église catholique pour attirer les NC, ce que Pierre Jurieu appelle « la sĂ©duction », mais aussi l’attachement des NC Ă  leurs biens et leur souhait de ne pas renoncer aux honneurs qu’ils pourraient perdre s’ils ne paraissaient pas de bons catholiques. Il est donc demandĂ© Ă  ceux qui ont abjurĂ© d’imiter l’apĂŽtre Pierre, de se repentir, et ainsi ils seront pardonnĂ©s . L’objectif de cette communication est avant tout d’étudier les moyens utilisĂ©s par les nicodĂ©mites pour tromper l’Église catholique et les difficultĂ©s rencontrĂ©es par l’historien pour analyser le nicodĂ©misme. C’est vĂ©ritablement durant cette fin du rĂšgne de Louis XIV que cette attitude des NC est la plus importante dans la mesure oĂč c’est au cours de cette pĂ©riode que les persĂ©cutions sont les plus fortes et la simulation un moyen d’échapper Ă  la rĂ©pression. AprĂšs la mort de Louis XIV, progressivement les enjeux ne sont plus les mĂȘmes

    A 3-Dimensional study of the Local Environment of Bright IRAS Galaxies: The AGN/Starburst connection

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    We present a 3-dimensional study of the local (≀100h−1\leq 100 h^{-1} kpc) and the large scale (≀\leq 1 h−1h^{-1} Mpc) environment of Bright IRAS Galaxies (BIRGs). For this purpose we use 87 BIRGs located at high galactic latitudes (with 0.008≀z≀\leq z \leq0.018) as well as a control sample of non-active galaxies having the same morphological, redshift and diameter size distributions as the corresponding BIRG sample. Using the Center for Astrophysics (CfA2) and Southern Sky Redshift Survey (SSRS) galaxy catalogues (mbâ‰Č15.5m_b\lesssim 15.5)as well as our own spectroscopic observations (mbâ‰Č19.0m_b\lesssim19.0) for a subsample of the original BIRG sample, we find that the fraction of BIRGs with a close neighbor is significantly higher than that of their control sample. Comparing with a related analysis of Sy1 and Sy2 galaxies of Koulouridis et al. (2006) we find that BIRGs have a similar environment as Sy2s, although the fraction of BIRGs with a bright close neighbor is even higher than that of Sy2 galaxies. An additional analysis of the relation between FIR colors and the type of activity of each BIRG shows a significant difference between the colors of strongly-interacting and non-interacting starbursts and a resemblance between the colors of non-interacting starbursts and Sy2s. Our results support the view where close interactions can drive molecular clouds towards the galactic center, triggering starburst activity and obscuring the nuclear activity. When the close neighbor moves away, starburst activity is reduced with the simultaneous appearance of an obscured (type 2) AGN. Finally, the complete disentanglement of the pair gives birth to an unobscured (type 1) AGN.Comment: Accepted for publication in The Astrophysical Journal,10 pages, 4 figure

    Recombinant gamma interferon provokes resistance of human breast cancer cells to spontaneous and IL-2 activated non-MHC restricted cytotoxicity.

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    Natural and lymphokine activated killer cells (NK and LAK) are believed to play an important role in the control of tumour progression and metastasis. Their specific receptors on tumours cells are still unknown. Several studies suggest that these cells recognise and eliminate abnormal cells with deleted or reduced expression of MHC class I molecules. Previous reports suggest that interferons (IFN), by increasing MHC class I expression on target cells, induce resistance to killing by NK cells. We investigated the role of MHC molecule expression by two human breast cancer cell lines T47D and ZR75-1 in their susceptibility to NK and LAK cells. These two cell lines spontaneously express low levels of HLA class I antigens but no HLA class II molecules. After IFN-gamma treatment they both overexpressed MHC class I and de novo expressed class II molecules as detected by flow cytometry, quantified by a radioimmunoassay and analysed by two-dimensional gel electrophoresis. Opposed to untreated cells these IFN-gamma treated cells were resistant to NK and LAK lysis. Furthermore, preincubation of IFN-gamma treated breast cancer cells with F(ab')2 fragments of monoclonal antibodies to HLA class I and HLA class II molecules was unable to restore lysis. In contrast, several complete monoclonal antibodies including anti-HLA class I and HLA class II induced the lysis of target cells whether or not they had been treated by IFN-gamma. The therapeutic use of monoclonal antibodies directed against antigens expressed on tumour cells (ADCC) in conjunction with interferon therapy should be discussed in lymphokine-based strategies for treatment of cancer patients
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