96 research outputs found
The Diabolo photometer and the future of ground-based millimetric bolometer devices
The millimetric atmospheric windows at 1 and 2 mm are interesting targets for
cosmological studies. Two broad areas appear leading this field: 1) the search
for high redshift star-forming galaxies and 2) the measurement of
Sunyaev-Zel'dovich (SZ) effect in clusters of galaxies at all redshifts. The
Diabolo photometer is a dual-channel photometer working at 1.2 and 2.1 mm and
dedicated to high angular resolution measurements of the Sunyaev--Zel'dovich
effect towards distant clusters. It uses 2 by 3 bolometers cooled down to 0.1 K
with a compact open dilution cryostat. The high resolution is provided by the
IRAM 30 m telescope. The result of several Winter campaigns are reported here,
including the first millimetric map of the SZ effect that was obtained by
Pointecouteau et al. (2001) on RXJ1347-1145, the non-detection of a millimetric
counterpart to the radio decrement towards PC1643+4631 and 2 mm number count
upper limits. We discuss limitations in ground-based single-dish millimetre
observations, namely sky noise and the number of detectors. We advocate the use
of fully sampled arrays of (100 to 1000) bolometers as a big step forward in
the millimetre continuum science. Efforts in France are briefly mentionned.Comment: 7 pages, 6 figures, to appear in the Proceedings of the 2K1BC
``Experimental Astronomy at millimeter wavelengths'', Breuil-Cervinia (AO)
Italy - July 9 - 13, 2001, Eds. M. De Petris et a
Charting the New Frontier of the Cosmic Microwave Background Polarization
The anisotropies of the cosmic microwave background are a gold mine for
cosmology and fundamental physics. ESA's Planck satellite should soon extract
all information from the temperature vein but will be limited concerning the
measurement of the degree of polarization of the anisotropies. This
polarization information allows new independent tests of the standard
cosmological paradigm, improves knowledge of cosmological parameters and last
but not least is the best window available for constraining the physics of the
very early universe, particularly the expected background of primordial
gravitational waves. But exploiting this vein will be a challenge, since the
sensitivity required is {\em at least} 10 times better than what Planck might
achieve at best, with the necessary matching level of control of all
systematics effects, both instrumental and astrophysical (foregrounds). We here
recall the cosmological context and the case for CMB polarization studies. We
also briefly introduce the SAMPAN project, a design study at CNES that aims at
detecting the primoridal gravitational wave background for a tensor to scalar
ratio T/S as small as 0.001.Comment: 4 pages, to appear in SF2A 2005 proceeding
Concomitant pulmonary and hepatic toxicity secondary to nitrofurantoin: a case report
<p>Abstract</p> <p>Background</p> <p>Concomitant pulmonary and hepatic toxicity secondary to nitrofurantoin is a rare but serious complication of the use of Nitrofurantoin.</p> <p>Case presentation</p> <p>A 72 year old woman taking Nitrofurantoin for recurrent urinary sepsis presenting with breathlessness abdominal discomfort and abnormal liver function tests is described. Drug toxicity secondary to Nitrofurantoin was diagnosed. Cessation of the drug and a course of steroids markedly improved her condition.</p> <p>Discussion</p> <p>We review the drug reactions associated with Nitrofurantoin and suggest an alternative treatment strategy for recurrent urinary sepsis.</p> <p>Conclusion</p> <p>Adverse drug reactions are an important cause of concomitant lung and liver toxicity and the mainstay of treatment is drug withdrawal.</p
Eosinophilic pneumonia associated with daptomycin: a case report and a review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Although several studies did not demonstrate that daptomycin may cause significantly higher rates of pulmonary adverse effects when compared with vancomycin or penicillinase-resistant penicillins, there have been a few case reports of severe pulmonary complications associated with daptomycin administration.</p> <p>Case presentation</p> <p>A rare case of eosinophilic pneumonia occurring 10 days after daptomycin administration in a 78-year-old Caucasian man with possible infectious endocarditis is described. He developed new onset fever, up to 38.5°C, with bilateral pulmonary crackles on physical examination and with no signs of severe respiratory failure. A chest computed tomography-scan showed bilateral nodular consolidations with air bronchograms and pleural effusions. Immediate discontinuation of daptomycin was followed by vigorous improvement of clinical signs and symptoms with progressive resolution of pulmonary consolidations a month later.</p> <p>Conclusion</p> <p>Physicians should be aware of this rare but serious complication during daptomycin treatment, and prompt discontinuation of the offending agent, with or without additional supportive treatment, must occur immediately.</p
Severe airway stenosis associated with Crohn's disease: Case report
BACKGROUND: Symptomatic respiratory tract involvement is not common in Crohn's disease. Upper-airway obstruction has been reported before in Crohn's disease and usually responds well to steroid treatment. CASE PRESENTATION: We report a case of a 32-year old patient with Crohn's disease who presented with progressively worsening dyspnea on exertion. Magnetic Resonance Imaging of the chest and bronchoscopy revealed severe tracheal stenosis and marked inflammation of tracheal mucosa. Histopathology of the lesion showed acute and chronic inflammation and extended ulceration of bronchial mucosa, without granulomas. Tracheal stenosis was attributed to Crohn's disease after exclusion of other possible causes and oral and inhaled steroids were administered. Despite steroid treatment, tracheal stenosis persisted and only mild symptomatic improvement was noted after 8 months of therapy. The patient subsequently underwent rigid bronchoscopy with successful dilatation and ablation of the stenosed areas and remission of her symptoms. CONCLUSION: Respiratory involvement in Crohn's disease might be more common than appreciated. Interventional pulmonology techniques should be considered in cases of tracheal stenosis due to Crohn's disease refractory to steroid treatment
First Detection of Polarization of the Submillimetre Diffuse Galactic Dust Emission by Archeops
We present the first determination of the Galactic polarized emission at 353
GHz by Archeops. The data were taken during the Arctic night of February 7,
2002 after the balloon--borne instrument was launched by CNES from the Swedish
Esrange base near Kiruna. In addition to the 143 GHz and 217 GHz frequency
bands dedicated to CMB studies, Archeops had one 545 GHz and six 353 GHz
bolometers mounted in three polarization sensitive pairs that were used for
Galactic foreground studies. We present maps of the I, Q, U Stokes parameters
over 17% of the sky and with a 13 arcmin resolution at 353 GHz (850 microns).
They show a significant Galactic large scale polarized emission coherent on the
longitude ranges [100, 120] and [180, 200] deg. with a degree of polarization
at the level of 4-5%, in agreement with expectations from starlight
polarization measurements. Some regions in the Galactic plane (Gem OB1,
Cassiopeia) show an even stronger degree of polarization in the range 10-20%.
Those findings provide strong evidence for a powerful grain alignment mechanism
throughout the interstellar medium and a coherent magnetic field coplanar to
the Galactic plane. This magnetic field pervades even some dense clouds.
Extrapolated to high Galactic latitude, these results indicate that
interstellar dust polarized emission is the major foreground for PLANCK-HFI CMB
polarization measurement.Comment: Submitted to Astron. & Astrophys., 14 pages, 12 Fig., 2 Table
Temperature and polarization angular power spectra of Galactic dust radiation at 353 GHz as measured by Archeops
We present the first measurement of temperature and polarization angular
power spectra of the diffuse emission of Galactic dust at 353 GHz as seen by
Archeops on 20% of the sky. The temperature angular power spectrum is
compatible with that provided by the extrapolation to 353 GHz of IRAS and DIRBE
maps using \cite{fds} model number 8. For Galactic latitudes deg
we report a 4 sigma detection of large scale ()
temperature-polarization cross-correlation and set upper limits to the and modes at . For Galactic latitudes deg, on the same
angular scales, we report a 2 sigma detection of temperature-polarization
cross-correlation . These
results are then extrapolated to 100 GHz to estimate the contamination in CMB
measurements by polarized diffuse Galactic dust emission. The signal is
then and for and 10 deg.
respectively. The upper limit on and becomes . If polarized dust emission at higher Galactic latitude cuts is
similar to the one we report here, then dust polarized radiation will be a
major foreground for determining the polarization power spectra of the CMB at
high frequencies above 100 GHz.Comment: 11 pages, 8 figures, submitted to A
Manipulation of Cell:Cell Contacts and Mesoderm Suppressing Activity Direct Lineage Choice from Pluripotent Primitive Ectoderm-Like Cells in Culture
In the mammal, the pluripotent cells of embryo differentiate and commit to either the mesoderm/endoderm lineages or the ectoderm lineage during gastrulation. In culture, the ability to direct lineage choice from pluripotent cells into the mesoderm/endoderm or ectoderm lineages will enable the development of technologies for the formation of highly enriched or homogenous populations of cells. Here we show that manipulation of cell:cell contact and a mesoderm suppressing activity in culture affects the outcome of pluripotent cell differentiation and when both variables are manipulated appropriately they can direct differentiation to either the mesoderm or ectoderm lineage. The disruption of cell:cell contacts and removal of a mesoderm suppressor activity results in the differentiation of pluripotent, primitive ectoderm-like cells to the mesoderm lineage, while maintenance of cell:cell contacts and inclusion, within the culture medium, of a mesoderm suppressing activity results in the formation of near homogenous populations of ectoderm. Understanding the contribution of these variables in lineage choice provides a framework for the development of directed differentiation protocols that result in the formation of specific cell populations from pluripotent cells in culture
The Cosmic Microwave Background Anisotropy Power Spectrum measured by Archeops
We present a determination by the Archeops experiment of the angular power
spectrum of the cosmic microwave background anisotropy in 16 bins over the
multipole range l=15-350. Archeops was conceived as a precursor of the Planck
HFI instrument by using the same optical design and the same technology for the
detectors and their cooling. Archeops is a balloon-borne instrument consisting
of a 1.5 m aperture diameter telescope and an array of 21 photometers
maintained at ~100 mK that are operating in 4 frequency bands centered at 143,
217, 353 and 545 GHz. The data were taken during the Arctic night of February
7, 2002 after the instrument was launched by CNES from Esrange base (Sweden).
The entire data cover ~ 30% of the sky.This first analysis was obtained with a
small subset of the dataset using the most sensitive photometer in each CMB
band (143 and 217 GHz) and 12.6% of the sky at galactic latitudes above 30
degrees where the foreground contamination is measured to be negligible. The
large sky coverage and medium resolution (better than 15 arcminutes) provide
for the first time a high signal-to-noise ratio determination of the power
spectrum over angular scales that include both the first acoustic peak and
scales probed by COBE/DMR. With a binning of Delta(l)=7 to 25 the error bars
are dominated by sample variance for l below 200. A companion paper details the
cosmological implications.Comment: A&A Letter, in press, 6 pages, 4 figures, see also
http://www.archeops.or
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