782 research outputs found

    CMB Telescopes and Optical Systems

    Full text link
    The cosmic microwave background radiation (CMB) is now firmly established as a fundamental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB observations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1: Telescopes and Instrumentatio

    Antioxidants and Oral Health

    Get PDF
    The oral cavity is ubiquitous of various bacteria due to steady assaults of various food substances, soft drinks, alcohol, tobacco products etc. Antioxidants are substances that inhibit oxidation and prevent the formation of free radicals, which are responsible for cellular damage. Since the oral tissues are vulnerable to cellular damage caused by free radicals and oxidation process hence maintenance, a good level of antioxidants is very essential to achieve optimal oral health. This review highlights the role of antioxidants in the prevention of oral diseases

    Bacteriophage-encoded depolymerases: their diversity and biotechnological applications

    Get PDF
    Bacteriophages (phages), natural enemies of bacteria, can encode enzymes able to degrade polymeric substances. These substances can be found in the bacterial cell surface, such as polysaccharides, or are produced by bacteria when they are living in biofilm communities, the most common bacterial lifestyle. Consequently, phages with depolymerase activity have a facilitated access to the host receptors, by degrading the capsular polysaccharides, and are believed to have a better performance against bacterial biofilms, since the degradation of extracellular polymeric substances by depolymerases might facilitate the access of phages to the cells within different biofilm layers. Since the diversity of phage depolymerases is not yet fully explored, this is the first review gathering information about all the depolymerases encoded by fully sequenced phages. Overall, in this study, 160 putative depolymerases, including sialidases, levanases, xylosidases, dextranases, hyaluronidases, peptidases as well as pectate/pectin lyases, were found in 143 phages (43 Myoviridae, 47 Siphoviridae, 37 Podoviridae, and 16 unclassified) infecting 24 genera of bacteria. We further provide information about the main applications of phage depolymerases, which can comprise areas as diverse as medical, chemical, or food-processing industry.DPP acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the grant SFRH/BD/76440/2011. SS is an FCT investigator (IF/01413/2013). The authors also thank FCT for the Strategic Project of the UID/BIO/04469/2013 unit, FCT and European Union funds (FEDER/COMPETE) for the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER027462)

    A model to assess the technological level of small businesses

    Get PDF
    none2In this paper we present a three-dimensional framework (named Cu- be of Corporate Technological Level – CCTL) to evaluate the technological po- sition of small enterprises from different points of view. This framework has been developed from existing tools with similar goals, already proposed by oth- er authors. Compared to existing ones, this framework differs primarily for the inclusion of a collaborative perspective. It reflects the distinctive features of the latest interactive and web 2.0 tools (chat, blogs, forums, ...), that allow compa- nies to manage their relationships with the external stakeholders of the supply chain. The proposed framework has been applied to a sample of small business- es to test its validity. Some business cases with different positions in the Cube are described.This paper is the joint effort of the authors. Francesca Maria Cesaroni developed sections 1, 2 and 5 and Domenico Consoli sections 3 and 4.openF.M.Cesaroni; D.ConsoliCesaroni, FRANCESCA MARIA; D., Consol

    First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA

    Get PDF
    The NOvA experiment has seen a 4.4σ signal of ν̄e appearance in a 2 GeV ν̄μ beam at a distance of 810 km. Using 12.33×1020 protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ν̄μ→ν̄e candidates with a background of 10.3 and 102 ν̄μ→ν̄μ candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm322|=2.48-0.06+0.11×10-3 eV2/c4 and sin2θ23 in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δCP=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ23 values in the upper octant by 1.6σ

    Coffin-Siris syndrome with Mayer-Rokitansky-Küster-Hauser syndrome: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>We report the case of an unusual association of Coffin-Siris syndrome with Mayer-Rokitansky-Küster-Hauser syndrome. This association has never previously been reported in the medical literature.</p> <p>Case presentation</p> <p>A nine-year-old Indian girl was referred to our hospital for growth retardation, mental retardation, lax joints, generalized hypertrichosis, and hypoplastic fifth fingernails and toenails. A thorough medical examination and evaluation revealed she had phenotypic features of Coffin-Siris syndrome, with Mayer-Rokitansky-Küster-Hauser syndrome on radiological evaluation. The karyotype of our patient was normal.</p> <p>Conclusion</p> <p>In an unexplained case of mental retardation with facies suggestive of Coffin-Siris syndrome, association with Mayer-Rokitansky-Küster-Hauser syndrome should be considered and the patient should be evaluated for the same. Both of these syndromes may have a common pathogenesis, as yet unknown. This case report has broad implications, as similar cases in future may give insights into the pathogenesis of both these syndromes.</p

    Interaction of the tetracyclines with double-stranded RNAs of random base sequence: new perspectives on the target and mechanism of action

    Get PDF
    The 16S rRNA binding mechanism proposed for the antibacterial action of the tetracyclines does not explain their mechanism of action against non-bacterial pathogens. In addition, several contradictory base pairs have been proposed as their binding sites on the 16S rRNA. This study investigated the binding of minocycline and doxycycline to short double-stranded RNAs (dsRNAs) of random base sequences. These tetracyclines caused a dose-dependent decrease in the fluorescence intensities of 6-carboxyfluorescein (FAM)-labelled dsRNA and ethidium bromide (EtBr)-stained dsRNA, indicating that both drugs bind to dsRNA of random base sequence in a manner that is competitive with the binding of EtBr and other nucleic acid ligands often used as stains. This effect was observable in the presence of Mg2+. The binding of the tetracyclines to dsRNA changed features of the fluorescence emission spectra of the drugs and the CD spectra of the RNA, and inhibited RNase III cleavage of the dsRNA. These results indicate that the double-stranded structures of RNAs may have a more important role in their interaction with the tetracyclines than the specific base pairs, which had hitherto been the subject of much investigation. Given the diverse functions of cellular RNAs, the binding of the tetracyclines to their double-stranded helixes may alter the normal processing and functioning of the various biological processes they regulate. This could help to explain the wide range of action of the tetracyclines against various pathogens and disease condition

    A Systematic Analysis of Eluted Fraction of Plasma Post Immunoaffinity Depletion: Implications in Biomarker Discovery

    Get PDF
    Plasma is the most easily accessible source for biomarker discovery in clinical proteomics. However, identifying potential biomarkers from plasma is a challenge given the large dynamic range of proteins. The potential biomarkers in plasma are generally present at very low abundance levels and hence identification of these low abundance proteins necessitates the depletion of highly abundant proteins. Sample pre-fractionation using immuno-depletion of high abundance proteins using multi-affinity removal system (MARS) has been a popular method to deplete multiple high abundance proteins. However, depletion of these abundant proteins can result in concomitant removal of low abundant proteins. Although there are some reports suggesting the removal of non-targeted proteins, the predominant view is that number of such proteins is small. In this study, we identified proteins that are removed along with the targeted high abundant proteins. Three plasma samples were depleted using each of the three MARS (Hu-6, Hu-14 and Proteoprep 20) cartridges. The affinity bound fractions were subjected to gelC-MS using an LTQ-Orbitrap instrument. Using four database search algorithms including MassWiz (developed in house), we selected the peptides identified at <1% FDR. Peptides identified by at least two algorithms were selected for protein identification. After this rigorous bioinformatics analysis, we identified 101 proteins with high confidence. Thus, we believe that for biomarker discovery and proper quantitation of proteins, it might be better to study both bound and depleted fractions from any MARS depleted plasma sample
    corecore