99 research outputs found

    Measurement of XUV-absorption spectra of ZnS radiatively heated foils

    Get PDF
    Time-resolved absorption of zinc sulfide (ZnS) and aluminum in the XUV-range has been measured. Thin foils in conditions close to local thermodynamic equilibrium were heated by radiation from laser-irradiated gold spherical cavities. Analysis of the aluminum foil radiative hydrodynamic expansion, based on the detailed atomic calculations of its absorption spectra, showed that the cavity emitted flux that heated the absorption foils corresponds to a radiation temperature in the range 55 60 eV. Comparison of the ZnS absorption spectra with calculations based on a superconfiguration approach identified the presence of species Zn6+ - Zn8+ and S5+ - S6+. Based on the validation of the radiative source simulations, experimental spectra were then compared to calculations performed by post-processing the radiative hydrodynamic simulations of ZnS. Satisfying agreement is found when temperature gradients are accounted for

    Investigation of extramammary sources of Group B Streptococcus reveals its unusual ecology and epidemiology in camels

    Get PDF
    Camels are vital to food production in the drylands of the Horn of Africa, with milk as their main contribution to food security. A major constraint to camel milk production is mastitis, inflammation of the mammary gland. The condition negatively impacts milk yield and quality as well as household income. A leading cause of mastitis in dairy camels is Streptococcus agalactiae, or group B Streptococcus (GBS), which is also a commensal and pathogen of humans and cattle. It has been suggested that extramammary reservoirs for this pathogen may contribute to the occurrence of mastitis in camels. We explored the molecular epidemiology of GBS in camels using a cross-sectional study design for sample collection and phenotypic, genomic and phylogenetic analysis of isolates. Among 88 adult camels and 93 calves from six herds in Laikipia County, Kenya, GBS was detected in 20% of 50 milk samples, 25% of 152 nasal swabs, 8% of 90 oral swabs and 3% of 90 rectal swabs, but not in vaginal swabs. Per camel herd, two to four sequence types (ST) were identified using Multi Locus Sequence Typing (MLST). More than half of the isolates belonged to ST617 or its single-locus variant, ST1652, with these STs found across all sample types. Capsular serotype VI was detected in 30 of 58 isolates. In three herds, identical STs were detected in milk and swab samples, suggesting that extramammary sources of GBS may contribute to the maintenance and spread of GBS within camel herds. This needs to be considered when developing prevention and control strategies for GBS mastitis. The high nasal carriage rate, low recto-vaginal carriage rate, and high prevalence of serotype VI for GBS in camels are in stark contrast to the distribution of GBS in humans and in cattle and reveal hitherto unknown ecological and molecular features of this bacterial species

    Investigation of extramammary sources of Group B Streptococcus reveals its unusual ecology and epidemiology in camels

    Get PDF
    Camels are vital to food production in the drylands of the Horn of Africa, with milk as their main contribution to food security. A major constraint to camel milk production is mastitis, inflammation of the mammary gland. The condition negatively impacts milk yield and quality as well as household income. A leading cause of mastitis in dairy camels is Streptococcus agalactiae, or group B Streptococcus (GBS), which is also a commensal and pathogen of humans and cattle. It has been suggested that extramammary reservoirs for this pathogen may contribute to the occurrence of mastitis in camels. We explored the molecular epidemiology of GBS in camels using a cross-sectional study design for sample collection and phenotypic, genomic and phylogenetic analysis of isolates. Among 88 adult camels and 93 calves from six herds in Laikipia County, Kenya, GBS was detected in 20% of 50 milk samples, 25% of 152 nasal swabs, 8% of 90 oral swabs and 3% of 90 rectal swabs, but not in vaginal swabs. Per camel herd, two to four sequence types (ST) were identified using Multi Locus Sequence Typing (MLST). More than half of the isolates belonged to ST617 or its single-locus variant, ST1652, with these STs found across all sample types. Capsular serotype VI was detected in 30 of 58 isolates. In three herds, identical STs were detected in milk and swab samples, suggesting that extramammary sources of GBS may contribute to the maintenance and spread of GBS within camel herds. This needs to be considered when developing prevention and control strategies for GBS mastitis. The high nasal carriage rate, low recto-vaginal carriage rate, and high prevalence of serotype VI for GBS in camels are in stark contrast to the distribution of GBS in humans and in cattle and reveal hitherto unknown ecological and molecular features of this bacterial species

    Radiative properties of stellar plasmas and open challenges

    Full text link
    The lifetime of solar-like stars, the envelope structure of more massive stars, and stellar acoustic frequencies largely depend on the radiative properties of the stellar plasma. Up to now, these complex quantities have been estimated only theoretically. The development of the powerful tools of helio- and astero- seismology has made it possible to gain insights on the interiors of stars. Consequently, increased emphasis is now placed on knowledge of the monochromatic opacity coefficients. Here we review how these radiative properties play a role, and where they are most important. We then concentrate specifically on the envelopes of β\beta Cephei variable stars. We discuss the dispersion of eight different theoretical estimates of the monochromatic opacity spectrum and the challenges we need to face to check these calculations experimentally.Comment: 6 pages, 5 figures, in press (conference HEDLA 2010

    Thermal and Optical Characterization of Undoped and Neodymium-Doped Y3ScAl4O12 Ceramics

    Get PDF
    Y3–3xNd3xSc1Al4O12 (x = 0, 0.01, and 0.02) ceramics were fabricated by sintering at high temperature under vacuum. Unit cell parameter refinement and chemical analysis have been performed. The morphological characterization shows micrograins with no visible defects. The thermal analysis of these ceramics is presented, by measuring the specific heat in the temperature range from 300 to 500 K. Their values at room temperature are in the range 0.81–0.90 J g1–K–1. The thermal conductivity has been determined by two methods: by the experimental measurement of the thermal diffusivity by the photopyroelectric method, and by spectroscopy, evaluating the thermal load. The thermal conductivities are in the range 9.7–6.5 W K–1 m–1 in the temperature interval from 300 to 500 K. The thermooptic coefficients were measured at 632 nm by the dark mode method using a prism coupler, and the obtained values are in the range 12.8–13.3 × 10–6 K–1. The nonlinear refractive index values at 795 nm have been evaluated to calibrate the nonlinear optical response of these materials.This work is supported by the Spanish Government under projects MAT2011-29255-C02-01-02, MAT2013-47395-C4-4-R, and the Catalan Government under project 2014SGR1358. It was also funded by the European Commission under the Seventh Framework Programme, project Cleanspace, FP7-SPACE-2010-1-GA No. 263044

    Detection of collagen triple helix repeat containing-1 and nuclear factor (erythroid-derived 2)-like 3 in colorectal cancer

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Collagen Triple Helix Repeat Containing-1 (CTHRC1) and Nuclear factor (erythroid-derived 2)-like 3 (NFE2L3) may be useful biomarker candidates for the diagnosis of colorectal cancer (CRC) since they have shown an increase messenger RNA transcripts (mRNA) expression level in adenomas and colorectal tumours when compared to normal tissues.</p> <p>Methods</p> <p>To evaluate CTHRC1 and NFE2L3 as cancer biomarkers, it was generated and characterised several novel specific polyclonal antibodies (PAb), monoclonal antibodies (MAbs) and soluble Fab fragments (sFabs) against recombinant CTHRC1 and NFE2L3 proteins, which were obtained from different sources, including a human antibody library and immunised animals. The antibodies and Fab fragments were tested for recognition of native CTHRC1 and NFE2L3 proteins by immunoblotting analysis and enzyme-linked immunosorbent assay (ELISA) in colorectal cell lines derived from tumour and cancer tissues.</p> <p>Results</p> <p>Both, antibodies and a Fab fragment showed high specificity since they recognised only their corresponding recombinant antigens, but not a panel of different unrelated- and related proteins.</p> <p>In Western blot analysis of CTHRC1, a monoclonal antibody designated CH21D7 was able to detect a band of the apparent molecular weight of a full-length CTHRC1 in the human colon adenocarcinoma cell line HT29. This result was confirmed by a double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with the monoclonal antibodies CH21D7 and CH24G2, detecting CTHRC1 in HT29 and in the colon adenocarcinoma cell line SW620.</p> <p>Similar experiments were performed with PAb, MAbs, and sFab against NFE2L3. The immunoblot analysis showed that the monoclonal antibody 41HF8 recognised NFE2L3 in HT29, and leukocytes. These results were verified by DAS-ELISA assay using the pairs PAb/sFab E5 and MAb 41HF8/sFab E5.</p> <p>Furthermore, an immunoassay for simultaneous detection of the two cancer biomarkers was developed using a Dissociation-Enhanced Lanthanide Fluorescent Immunoassay technology (DELFIA).</p> <p>Conclusions</p> <p>In conclusion, the antibodies obtained in this study are specific for CTHRC1 and NFE2L3 since they do not cross-react with unrelated- and related proteins and are useful for specific measurement of native CTHRC1 and NFE2L3 proteins. The antibodies and immunoassays may be useful for the analysis of CTHRC1 and NFE2L3 in clinical samples and for screening of therapeutic compounds in CRC.</p

    Octahedral molybdenum cluster complexes with aromatic sulfonate ligands

    Get PDF
    This article describes the synthesis, structures and systematic study of the spectroscopic and redox properties of a series of octahedral molybdenum metal cluster complexes with aromatic sulfonate ligands (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] (where X- is Cl-, Br- or I-; OTs- is p-toluenesulfonate and PhSO3 - is benzenesulfonate). All the complexes demonstrated photoluminescence in the red region and an ability to generate singlet oxygen. Notably, the highest quantum yields (>0.6) and narrowest emission bands were found for complexes with a {Mo6I8}4+ cluster core. Moreover, cyclic voltammetric studies revealed that (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] confer enhanced stability towards electrochemical oxidation relative to corresponding starting complexes (nBu4N)2[{Mo6X8}X6]

    Integrative genetic map of repetitive DNA in the sole Solea senegalensis genome shows a Rex transposon located in a proto-sex chromosome

    Get PDF
    Repetitive sequences play an essential role in the structural and functional evolution of the genome, particularly in the sexual chromosomes. The Senegalese sole (Solea senegalensis) is a valuable flatfish in aquaculture albeit few studies have addressed the mapping and characterization of repetitive DNA families. Here we analyzed the Simple Sequence Repeats (SSRs) and Transposable elements (TEs) content from fifty-seven BAC clones (spanning 7.9 Mb) of this species, located in chromosomes by multiple fluorescence in situ hybridization (m-BAC-FISH) technique. The SSR analysis revealed an average density of 675.1 loci per Mb and a high abundance (59.69%) of dinucleotide coverage was observed, being 'AC' the most abundant. An SSR-FISH analysis using eleven probes was also carried out and seven of the 11 probes yielded positive signals. 'AC' probes were present as large clusters in almost all chromosomes, supporting the bioinformatic analysis. Regarding TEs, DNA transposons (Class II) were the most abundant. In Class I, LINE elements were the most abundant and the hAT family was the most represented in Class II. Rex/Babar subfamily, observed in two BAC clones mapping to chromosome pair 1, showed the longest match. This chromosome pair has been recently reported as a putative sexual proto-chromosome in this species, highlighting the possible role of the Rex element in the evolution of this chromosome. In the Rex1 phylogenetic tree, the Senegalese sole Rex1 retrotransposon could be associated with one of the four major ancient lineages in fish genomes, in which it is included O. latipes
    corecore