708 research outputs found

    Interpretation of UV Absorption Lines in SN1006

    Get PDF
    We present a theoretical interpretation of the broad silicon and iron UV absorption features observed with the Hubble Space Telescope in the spectrum of the Schweizer-Middleditch star behind the remnant of Supernova 1006. These features are caused by supernova ejecta in SN1006. We propose that the redshifted SiII2 1260 A feature consists of both unshocked and shocked SiII. The sharp red edge of the line at 7070 km/s indicates the position of the reverse shock, while its Gaussian blue edge reveals shocked Si with a mean velocity of 5050 km/s and a dispersion of 1240 km/s, implying a reverse shock velocity of 2860 km/s. The measured velocities satisfy the energy jump condition for a strong shock, provided that all the shock energy goes into ions, with little or no collisionless heating of electrons. The line profiles of the SiIII and SiIV absorption features indicate that they arise mostly from shocked Si. The total mass of shocked and unshocked Si inferred from the SiII, SiIII and SiIV profiles is M_Si = 0.25 \pm 0.01 Msun on the assumption of spherical symmetry. Unshocked Si extends upwards from 5600 km/s. Although there appears to be some Fe mixed with the Si at lower velocities < 7070 km/s, the absence of FeII absorption with the same profile as the shocked SiII suggests little Fe mixed with Si at higher (before being shocked) velocities. The column density of shocked SiII is close to that expected for SiII undergoing steady state collisional ionization behind the reverse shock, provided that the electron to SiII ratio is low, from which we infer that most of the shocked Si is likely to be of a fairly high degree of purity, unmixed with other elements. We propose that the ambient interstellar density on the far side of SN1006 is anomalously low compared to the density around the rest of the remnant. ThisComment: 24 pages, with 8 figures included. Accepted for publication in the Astrophysical Journa

    Comparison of reproducibility, accuracy, sensitivity, and specificity of miRNA quantification platforms

    Get PDF
    Given the increasing interest in their use as disease biomarkers, the establishment of reproducible, accurate, sensitive, and specific platforms for microRNA (miRNA) quantification in biofluids is of high priority. We compare four platforms for these characteristics: small RNA sequencing (RNA-seq), FirePlex, EdgeSeq, and nCounter. For a pool of synthetic miRNAs, coefficients of variation for technical replicates are lower for EdgeSeq (6.9%) and RNA-seq (8.2%) than for FirePlex (22.4%); nCounter replicates are not performed. Receiver operating characteristic analysis for distinguishing present versus absent miRNAs shows small RNA-seq (area under curve 0.99) is superior to EdgeSeq (0.97), nCounter (0.94), and FirePlex (0.81). Expected differences in expression of placenta-associated miRNAs in plasma from pregnant and non-pregnant women are observed with RNA-seq and EdgeSeq, but not FirePlex or nCounter. These results indicate that differences in performance among miRNA profiling platforms impact ability to detect biological differences among samples and thus their relative utility for research and clinical use

    The role of the Maternity Liaison Officer in provision of primary health care: A values-based service model

    Full text link
    Background: A policy directive of the New South Wales government focused on ensuring that all ethnic groups within the community have appropriate and equitable access to services led to the introduction of the maternity liaison officer (MLO) program in the late 1990s. The role of the MLO is to work alongside health professionals to provide education, social support and counselling to pregnant refugee and migrant women of culturally and linguistically diverse backgrounds (CALD). Methods: We reviewed reports and policy documents from 2008 to examine the attributes of this hospital-based service model and share insights into how the MLOs deliver care to meet the needs of mothers and babies. Findings: Maternity liaison officers have readily assumed the responsibility of maintaining current knowledge and building competency in improving the health and wellbeing of refugee and migrant women and newborns. They act as important bridge between women and the health system enabling vulnerable women to competently navigate their maternity journey, gynaecological care and the care of newborn infants in a culturally sensitive and appropriate manner. Discussion and conclusion: This service model offers an acceptable way to support the delivery of maternity care to women and include those from refugee and CALD- backgrounds. Investment in the rigorous evaluation of this service is needed to provide strong evidence to optimise service delivery and guide future decision making

    Clonal dissemination of Klebsiella pneumoniae ST258 harbouring KPC-2 in Argentina

    Get PDF
    AbstractThe present work describes the abrupt emergence of Klebsiella pneumoniae carbapenemase (KPC) and characterizes the first 79 KPC-producing enterobacteria from Argentina (isolated from 2006 to 2010). The emergence of blaKPC-2 was characterized by two patterns of dispersion: the first was the sporadic occurrence in diverse enterobacteria from distant geographical regions, harbouring plasmids of different incompatibility groups and blaKPC-2 in an unusual genetic environment flanked by ISKpn8-ΔblaTEM-1 and ISKpn6-like. blaKPC-2 was associated with IncL/M transferable plasmids; the second was the abrupt clonal spread of K. pneumoniae ST258 harbouring blaKPC-2 in Tn4401a

    Monitoramento do propranolol plasmático em crianças operadas da tetralogia de Fallot através de micrométodo utilizando a cromatografia líquida de alta eficiência

    Get PDF
    OBJECTIVE: To evaluate the analytical micromethod using liquid chromatography for the quantification of propranolol in children submitted to surgery of tetralogy of Fallot (TLF). Methods: Only 0.2 mL of plasma is required for the assay. Peaks eluted at 8.4 (Propranolol) and 17.5 min (verapamil, internal standard) from a C18 column, with a mobile phase 0.1 M acetate buffer, pH 5.0, and acetonitrile (60:40, v/v) at flow rate 0.7 mL/min, detected at 290 nm (excitation) and 358 nm (emission). Surgery was started 776 min of drug administration (8.7mg, mean); seven blood samples were collected from six patients (4M/2F; 2.1yrs;11.5kg; 0.80m; 18.9kg/m²). RESULTS: Confidence limits of the method showed high selectivity and recovery, sensitivity of 0.02ng/mL, good linearity (0.05-1000ng/mL), precision of 8.6% and accuracy of 3.1%. The mean duration of surgery was 283.2min, with the patients remaining under cardiopulmonary bypass (CPB) for 114min. A declining curve of propranolol plasma concentration was obtained after the last dose in the night that preceded the day of surgery. Plasma concentration also was normalized with hematocrit due to the hemodilution caused by the CPB procedure. On the other hand a decrease on drug plasma concentration was obtained between periods, the beginning of surgery to the postoperative day 2 (7.09 ng/mL and 0.05 ng/mL, pOBJETIVO: Avaliar o micrométodo analítico empregando a cromatografia líquida para quantificação de propranolol em crianças operadas de tetralogia de Fallot (TLF). MÉTODO: Requereu-se apenas volumes de 0,2mL de plasma para a realização do ensaio. Os picos foram eluídos em 8.4 (Propranolol) e 17.5 min (verapamil, padrão interno) de uma coluna C18, com fase móvel (tampão acetato 0,1 M pH 5,0 e acetonitrila, 60:40, v/v) em fluxo de 0,7 mL/min, sendo detectados em 290 nm (excitação) e em 358 nm (emissão). A cirurgia iniciou-se 776 min depois da dose administrada (8,7mg, média) e sete amostras de sangue foram coletadas de seis pacientes (4M/2F; 2,1 anos;11,5kg; 0,80m;18,9kg/m²). RESULTADOS: Os limites de confiança do método analítico evidenciaram alta seletividade e recuperação, sensibilidade (0,02ng/mL), boa linearidade (0,05-1000ng/mL), precisão de 8,6% e exatidão de 3,1%. A duração média da cirurgia foi de 283,2min, com os pacientes em circulação extracorpórea (CEC) durante 114min. Uma curva de declínio do propranolol no plasma foi obtida após a última dose na noite que precedeu o dia da intervenção. A concentração plasmática foi normalizada com o hematócrito devido à hemodiluição causada pela CEC. Por outro lado obteve-se decréscimo nas concentrações plasmáticas entre os períodos início da cirurgia para o 2º dia de pós-operatório (7,09 ng/mL e0,05 ng/mL,

    Measurement of the Luminosity in the ZEUS Experiment at HERA II

    Full text link
    The luminosity in the ZEUS detector was measured using photons from electron bremsstrahlung. In 2001 the HERA collider was upgraded for operation at higher luminosity. At the same time the luminosity-measuring system of the ZEUS experiment was modified to tackle the expected higher photon rate and synchrotron radiation. The existing lead-scintillator calorimeter was equipped with radiation hard scintillator tiles and shielded against synchrotron radiation. In addition, a magnetic spectrometer was installed to measure the luminosity independently using photons converted in the beam-pipe exit window. The redundancy provided a reliable and robust luminosity determination with a systematic uncertainty of 1.7%. The experimental setup, the techniques used for luminosity determination and the estimate of the systematic uncertainty are reported.Comment: 25 pages, 11 figure
    corecore