3,141 research outputs found

    Strong evidence for an accelerating universe

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    A recent analysis of the Supernova Ia data claims a 'marginal' (3σ\sim3\sigma) evidence for a cosmic acceleration. This result has been complemented with a non-accelerating Rh=ctR_{h}=ct cosmology, which was presented as a valid alternative to the Λ\LambdaCDM model. In this paper, we use the same analysis to show that a non-marginal evidence for acceleration is actually found. We compare the standard Friedmann models to the Rh=ctR_{h}=ct cosmology by complementing SN Ia data with the Baryon Acoustic Oscillations, Gamma Ray Bursts and Observational Hubble datasets. We also study the power-law model which is a functional generalisation of Rh=ctR_{h}=ct. We find that the evidence for late-time acceleration is beyond refutable at a 4.56σ\sigma confidence level from SN Ia data alone, and at an even stronger confidence level (5.38σ5.38\sigma) from our joint analysis. Also, the non-accelerating Rh=ctR_{h}=ct model fails to statistically compare with the Λ\LambdaCDM having a Δ(AIC)30\Delta(\text{AIC})\sim30

    Developing an observational rubric of writing: Preliminary reliability and validity evidence

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    The purpose of this paper is (1) to report on the design of the early writing observational writing rubric designed to observe and describe change over time in the writing of children emerging into conventional literacy (ages 6–7) within an instructional setting and (2) to investigate the initial reliability and validity of the rubric. We used an extant data set that included 52 videos of writing instruction in Reading Recovery lessons (approximately 520 minutes) and pre- and post-intervention test data, for 24 students, taken at multiple time points across a 20-week period. Dependent sample t-tests and HLM were used to ascertain if the rubric was sensitive to change over occasions. We also considered if the scores correlated with external literacy measures. The findings suggest that the rubric has good initial reliability and validity and is a useful tool for researchers to observe and measure change over time as young children write in an instructional setting; further validation work is required for use in other settings

    Gestione dell'Autoparco dell'INGV - Sezione di Catania

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    L'autoparco è un settore di vitale importanza per la sezione, è importante sempre tenere sotto controllo la disponibilità dei mezzi e gli spostamenti effettuati dagli stessi. A tale scopo nel sito intranet della Sezione, è stata aggiunta una sezione per la gestione delle auto, da cui è possibile effettuare la prenotazione o disdetta, annotare l’avvenuto prelievo, riconsegna e manutenzione ordinaria delle auto. Nella Home Page del sito, selezionando la finestra “AMM. & SERV. TECNICI” (Amministrazione e Servizi tecnici) è possibile, cliccando sulle apposite voci del menù , accedere alle seguenti pagine interne (vedi Figura 1): 1. Prenotazione e/o la disdetta di un autoveicolo. 2. Prelievo / riconsegna. 3. Manutenzione automezzi. La pagina dedicata alla prenotazione e/o disdetta di un’autovettura è accessibile da tutto il personale. La pagina dedicata alla gestione del prelievo di autovettura, della sua riconsegna e/o del prelievo immediato di un autovettura, è riservato alla sola Vigilanza. Infine la pagina per la manutenzione ordinaria del parco auto l’accesso è riservato soltanto al responsabile. Ogni dipendente potrà, autonomamente, prenotare solamente una delle macchine assegnate alla Unità Funzionale (UF) di appartenenza. Nel caso in cui fosse necessario prenotare un autoveicolo appartenente ad un’altra UF, occorre farlo prenotare da un dipendente ad essa afferente che conosce la programmazione delle attività e farsi inserire come “autista”

    Perturbations of the local gravity field due to mass distribution on precise measuring instruments: a numerical method applied to a cold atom gravimeter

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    We present a numerical method, based on a FEM simulation, for the determination of the gravitational field generated by massive objects, whatever geometry and space mass density they have. The method was applied for the determination of the self gravity effect of an absolute cold atom gravimeter which aims at a relative uncertainty of 10-9. The deduced bias, calculated with a perturbative treatment, is finally presented. The perturbation reaches (1.3 \pm 0.1) \times 10-9 of the Earth's gravitational field.Comment: 12 pages, 7 figure

    A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen-1.

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    Babesiosis due to Babesia bigemina is a relevant tick‑borne disease, affecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA‑1) ‑ have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA‑1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA‑1 codifying region was amplified and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA‑1 was purified by affinity chromatography and used to set up the best condition for an ELISA protocol. Bovine field sera positive to B. bigemina were used to evaluate the presence of anti‑AMA‑1 antibodies. In order to verify the assay specificity, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Significant differences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No significant reaction was observed with T. annulata positive sera. The results showed that AMA‑1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies

    Monoclonal antibodies to treat multiple myeloma: A dream come true

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    Immunotherapy is increasingly used in the treatment of multiple myeloma (MM). Monoclonal antibodies (mAbs) are safe and effective ways to elicit immunotherapeutic responses. In 2015, daratumumab has become the first mAb approved by the Food and Drug Administration for clinical use in MM and, in the last 5 years, a lot of clinical and preclinical research has been done to optimize the use of this drug class. Currently, mAbs have already become part of standard-of-care combinations for the treatment of relapsed/refractory MM and very soon they will also be used in the frontline setting. The success of simple mAbs (‘naked mAbs’) prompted the development of new types of molecules. Antibody–drug conjugates (ADCs) are tumor-targeting mAbs that release a cytotoxic payload into the tumor cells upon antigen binding in order to destroy them. Bispecific antibodies (BiAbs) are mAbs simultaneously targeting a tumor-associated antigen and an immune cell-associated antigen in order to redirect the immune cell cytotoxicity against the tumor cell. These different constructs produced solid preclinical data and promising clinical data in phase I/II trials. The aim of this review article is to summarize all the recent developments in the field, including data on naked mAbs, ADCs and BiAbs

    Self-attraction effect and correction on three absolute gravimeters

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    The perturbations of the gravitational field due to the mass distribution of an absolute gravimeter have been studied. The so called Self Attraction Effect (SAE) is crucial for the measurement accuracy, especially for the International Comparisons, and for the uncertainty budget evaluation. Three instruments have been analysed: MPG-2, FG5-238 and IMPG-02. The SAE has been calculated using a numerical method based on FEM simulation. The observed effect has been treated as an additional vertical gravity gradient. The correction (SAC) to be applied to the computed g value has been associated with the specific height level, where the measurement result is typically reported. The magnitude of the obtained corrections is of order 1E-8 m/s2.Comment: 14 pages, 8 figures, submitted to Metrologi

    Comparison of Theoretical Starburst Photoionisation Models for Optical Diagnostics

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    We study and compare different examples of stellar evolutionary synthesis input parameters used to produce photoionisation model grids using the MAPPINGS V modelling code. The aim of this study is to (a) explore the systematic effects of various stellar evolutionary synthesis model parameters on the interpretation of emission lines in optical strong-line diagnostic diagrams, (b) characterise the combination of parameters able to reproduce the spread of local galaxies located in the star-forming region in the Sloan Digital Sky Survey, and (c) investigate the emission from extremely metal-poor galaxies using photoionisation models. We explore and compare the stellar input ionising spectrum (stellar population synthesis code [Starburst99, SLUG, BPASS], stellar evolutionary tracks, stellar atmospheres, star-formation history, sampling of the initial mass function) as well as parameters intrinsic to the H II region (metallicity, ionisation parameter, pressure, H II region boundedness). We also perform a comparison of the photoionisation codes MAPPINGS and CLOUDY. On the variations in the ionising spectrum model parameters, we find that the differences in strong emission-line ratios between varying models for a given input model parameter are small, on average ~0.1 dex. An average difference of ~0.1 dex in emission-line ratio is also found between models produced with MAPPINGS and CLOUDY. Large differences between the emission-line ratios are found when comparing intrinsic H II region parameters. We find that low-metallicity galaxies are better explained by a density-bounded H II region and higher pressures better encompass the spread of galaxies at high redshift.Comment: 33 pages, 26 figures, accepted for publication in Ap
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