Validation of IFE-1.6 SCIAMACHY limb ozone profiles

International audienceThe IFE-1.6 scientific data set of SCIAMACHY limb ozone profiles is validated for the period August?December 2002. The data set provides ozone profiles over an altitude range of 15?45 km. The main uncertainty in the profiles is the imprecise knowledge of the pointing of the instrument, leading to retrieved profiles that are shifted in altitude direction. To obtain a first order correction for the pointing error and the remaining uncertainties, the retrieved profiles are compared to their a-priori value and ozone sondes based on absolute distance and equivalent latitude criteria. A vertical shift of the satellite profiles with 2 km downward is found to be an appropriate correction for the data set studied. A total root-mean-square difference between limb profiles and sondes of 10?15% remains for the stratospheric ozone profile after application of the correction. Small biases are left above and below the ozone maximum at mid latitudes, where the vertical gradients in the retrieved product are in general too strong

New high-sensitivity, milliarcsecond resolution results from routine observations of lunar occultations at the ESO VLT

(Abridged) Lunar occultations (LO) are a very efficient and powerful technique, that achieves the best combination of high angular resolution and sensitivity possible today at near-infrared wavelengths. Given that the events are fixed in time, that the sources are occulted randomly, and that the telescope use is minimal, the technique is very well suited for service mode observations. We have established a program of routine LO observations at the VLT observatory, especially designed to take advantage of short breaks available in-between other programs. We have used the ISAAC instrument in burst mode, capable of producing continuous read-outs at millisecond rates on a suitable subwindow. Given the random nature of the source selection, our aim has been primarily the investigation of a large number of stellar sources at the highest angular resolution in order to detect new binaries. Serendipitous results such as resolved sources and detection of circumstellar components were also anticipated. We have recorded the signal from background stars for a few seconds, around the predicted time of occultation by the Moon's dark limb. At millisecond time resolution, a characteristic diffraction pattern can be observed. Patterns for two or more sources superimpose linearly, and this property is used for the detection of binary stars. The detailed analysis of the diffraction fringes can be used to measure specific properties such as the stellar angular size and the presence of extended light sources such as a circumstellar shell. We present a list of 191 stars for which LO data could be recorded and analyzed. Results include the detection of 16 binary and 2 triple stars, all but one of which were previously unknown. The projected angular separations are as small as 4 milliarcseconds and magnitude differences as high as ?K=5.8 mag...Comment: 10 pages, 3 figures, to be published in A&

Improving cloud information over deserts from SCIAMACHY Oxygen A-band measurements

International audienceThe retrieval of column densities and concentration profiles of atmospheric trace gas species from satellites is sensitive to light scattered by clouds. The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument on the Envisat satellite, principally designed to retrieve trace gases in the atmosphere, is also capable of detecting clouds. FRESCO (Fast Retrieval Scheme for Clouds from the Oxygen A-band) is a fast and robust algorithm providing cloud information from the O2 A-band for cloud correction of ozone. FRESCO provides a consistent set of cloud products by retrieving simultaneously effective cloud fraction and cloud top pressure. The FRESCO retrieved values are compared with the SCIAMACHY Level 2 operational cloud fraction of OCRA (Optical Cloud Recognition Algorithm) but, also, with cloud information from HICRU (Heidelberg Iterative Cloud Retrieval Utilities), SACURA (SemiAnalytical CloUd Retrieval Algorithm) and the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument. The results correlate well, but FRESCO overestimates cloud fraction over deserts. Thus, to improve retrievals at these locations, the FRESCO surface albedo databases are decontaminated from the presence of desert dust aerosols. This is achieved by using the GOME Absorbing Aerosol Index. It is shown that this approach succeeds well in producing more accurate cloud information over the Sahara

The yellow hypergiants HR 8752 and rho Cassiopeiae near the evolutionary border of instability

High-resolution near-ultraviolet spectra of the yellow hypergiants HR 8752 and rho Cassiopeiae indicate high effective temperatures placing both stars near the T_eff border of the ``yellow evolutionary void''. At present, the temperature of HR 8752 is higher than ever. For this star we found Teff=7900+-200 K, whereas rho Cassiopeiae has Teff=7300+-200 K. Both, HR 8752 and rho Cassiopeiae have developed strong stellar winds with Vinf ~ 120 km/s and Vinf ~ 100 km/s, respectively. For HR 8752 we estimate an upper limit for the spherically symmetric mass-loss of 6.7X10^{-6}M_solar/yr. Over the past decades two yellow hypergiants appear to have approached an evolutionary phase, which has never been observed before. We present the first spectroscopic evidence of the blueward motion of a cool super/hypergiant on the HR diagram.Comment: 13 pages including 3 figures. Accepted for publication in ApJ Letter

REVISITING ANNA MOSCOWITZ\u27S KROSS\u27S CRITIQUE OF NEW YORK CITY\u27S WOMEN\u27S COURT: THE CONTINUED PROBLEM OF SOLVING THE PROBLEM OF PROSTITUTION WITH SPECIALIZED CRIMINAL COURTS

This article explores New York City\u27s non-traditional, judicially based response to prostitution. This article first recounts the history of New York City’s Women’s Court. It then examines the work of the Midtown Community Court, the “problem-solving court” established in 1993 to address criminal issues, like prostitution, in Midtown Manhattan. It also discusses the renewed concerns about sex work in New York and describe the movement, propelled by modern reformers, to address prostitution through specialty courts. It then contrasts the shared features and attributes of the Women’s Court and Midtown Court models. Finally, the article urges modern reformers to step back from the problem-solving court movement and their call for the creation of more such specialized criminal courts

An in-depth study of the pre-polar candidate WX Leonis Minoris

Optical photometry, spectroscopy, and XMM-Newton ultraviolet and X-ray observations with full phase coverage are used for an in-depth study of WXLMi, a system formerly termed a low-accretion rate polar. We find a constant low-mass accretion rate, ˙M ∼ 1.5 × 10−13 M yr−1, a peculiar accretion geometry with one spot not accessible via Roche-lobe overflow, a low temperature of the white dwarf, Teff < 8000 K, and the secondary very likely Roche-lobe underfilling. All this lends further support to the changed view on WXLMi and related systems as detached binaries, i.e. magnetic post-common envelope binaries without significant Rochelobe overflow in the past. The transfer rate determined here is compatible with accretion from a stellar wind. We use cyclotron spectroscopy to determine the accretion geometry and to constrain the plasma temperatures. Both cyclotron spectroscopy and X-ray plasma diagnostics reveal low plasma temperatures below 3 keV on both accretion spots. For the low-m˙ , high-B plasma at the accretion spots in WXLMi, cyclotron cooling dominates thermal plasma radiation in the optical. Optical spectroscopy and X-ray timing reveal atmospheric, chromospheric, and coronal activity at the saturation level on the dM4.5 secondary star

СВЧ плазмохимическое осаждение структур для высокоапертурных планарных оптических волноводов

Представлены результаты разработки технологии и исследования оптических характеристик высокоапертурных ПОВ на основе SiO₂-F | SiO₂ | SiO₂-F-структур, формируемых в плазме СВЧ-разряда

Loss of microbial topography between oral and nasopharyngeal microbiota and development of respiratory infections early in life

Rationale: The respiratory microbiota is increasingly being appreciated as an important mediator in the susceptibility to childhood respiratory tract infections (RTIs). Pathogens are presumed to originate from the nasopharyngeal ecosystem. Objectives: To investigate the association between early life respiratory microbiota and development of childhood RTIs. Methods: In a prospective birth cohort (Microbiome Utrecht Infant Study: MUIS), we characterized the oral microbiota longitudinally from birth until 6 months of age of 112 infants (nine regular samples/subject) and compared them with nasopharyngeal microbiota using 16S-rRNA–based sequencing. We also characterized oral and nasopharynx samples during RTI episodes in the first half year of life. Measurements and Main Results: Oral microbiota were driven mostly by feeding type, followed by age, mode of delivery, and season of sampling. In contrast to our previously published associations between nasopharyngeal microbiota development and susceptibility to RTIs, oral microbiota development was not directly associated with susceptibility to RTI development. However, we did observe an influx of oral taxa, such as Neisseria lactamica, Streptococcus, Prevotella nanceiensis, Fusobacterium, and Janthinobacterium lividum, in the nasopharyngeal microbiota before and during RTIs, which was accompanied by reduced presence and abundance of Corynebacterium, Dolosigranulum, and Moraxella spp. Moreover, this phenomenon was accompanied by reduced niche differentiation indicating loss of ecological topography preceding confirmed RTIs. This loss of ecological topography was further augmented by start of daycare, and linked to consecutive development of symptomatic infections. Conclusions: Together, our results link the loss of topography to subsequent development of RTI episodes. This may lead to new insights for prevention of RTIs and antibiotic use in childhood

Benchmarking laboratory processes to characterise low-biomass respiratory microbiota

Abstract The low biomass of respiratory samples makes it difficult to accurately characterise the microbial community composition. PCR conditions and contaminating microbial DNA can alter the biological profile. The objective of this study was to benchmark the currently available laboratory protocols to accurately analyse the microbial community of low biomass samples. To study the effect of PCR conditions on the microbial community profile, we amplified the 16S rRNA gene of respiratory samples using various bacterial loads and different number of PCR cycles. Libraries were purified by gel electrophoresis or AMPure XP and sequenced by V2 or V3 MiSeq reagent kits by Illumina sequencing. The positive control was diluted in different solvents. PCR conditions had no significant influence on the microbial community profile of low biomass samples. Purification methods and MiSeq reagent kits provided nearly similar microbiota profiles (paired Bray–Curtis dissimilarity median: 0.03 and 0.05, respectively). While profiles of positive controls were significantly influenced by the type of dilution solvent, the theoretical profile of the Zymo mock was most accurately analysed when the Zymo mock was diluted in elution buffer (difference compared to the theoretical Zymo mock: 21.6% for elution buffer, 29.2% for Milli-Q, and 79.6% for DNA/RNA shield). Microbiota profiles of DNA blanks formed a distinct cluster compared to low biomass samples, demonstrating that low biomass samples can accurately be distinguished from DNA blanks. In summary, to accurately characterise the microbial community composition we recommend 1. amplification of the obtained microbial DNA with 30 PCR cycles, 2. purifying amplicon pools by two consecutive AMPure XP steps and 3. sequence the pooled amplicons by V3 MiSeq reagent kit. The benchmarked standardized laboratory workflow presented here ensures comparability of results within and between low biomass microbiome studies