108 research outputs found

    Fast and real-time electrical transistor assay for quantifying SARS-CoV-2 neutralizing antibodies

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    Due to the SARS-CoV-2 pandemic renewed attention has been directed towards viral neutralization assays and neutralizing antibodies quantification, for vaccine pre-clinical trials and determining vaccine efficacy over time. The gold standard to assess antibody titer is the plaque reduction neutralization test, an end-point assay which evaluates the highest serum antibody dilution that neutralizes viral replication, by inspecting the cytopathic effect induced on cell cultures. Here, we use planar, PEDOT:PSS-based organic electrochemical transistors for real-time, remote-controlled, reliable and fast electrical monitoring of the cytopathic effect induced by SARS29 CoV-2 on Vero E6 cell lines, allowing the quantification of serum neutralizing titer. Our low-cost and scalable device has the potential to speed-up large-scale viral neutralization screening without the need for cancerous staining or highly specialized operators. Finally, the technology could be easily transferred to assess neutralizing antibody response towards different viruses in their permissive cell substrates

    Search for Exotic Strange Quark Matter in High Energy Nuclear Reactions

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    We report on a search for metastable positively and negatively charged states of strange quark matter in Au+Pb reactions at 11.6 A GeV/c in experiment E864. We have sampled approximately six billion 10% most central Au+Pb interactions and have observed no strangelet states (baryon number A < 100 droplets of strange quark matter). We thus set upper limits on the production of these exotic states at the level of 1-6 x 10^{-8} per central collision. These limits are the best and most model independent for this colliding system. We discuss the implications of our results on strangelet production mechanisms, and also on the stability question of strange quark matter.Comment: 21 pages, 9 figures, to be published in Nuclear Physics A (Carl Dover memorial edition

    Search for Strange Quark Matter Produced in Relativistic Heavy Ion Collisions

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    We present the final results from Experiment 864 of a search for charged and neutral strange quark matter produced in interactions of 11.5 GeV/c per nucleon Au beams with Pt or Pb targets. Searches were made for strange quark matter with A>4. Approximately 30 billion 10% most central collisions were sampled and no strangelet states with A<100 were observed. We find 90% confidence level upper limits of approximately 10^{-8} per central collision for both charged and neutral strangelets. These limits are for strangelets with proper lifetimes greater than 50 ns. Also limits for H^{0}-d and pineut production are given. The above limits are compared with the predictions of various models. The yields of light nuclei from coalescence are measured and a penalty factor for the addition of one nucleon to the coalescing nucleus is determined. This is useful in gauging the significance of our upper limits and also in planning future searches for strange quark matter.Comment: 35 pages, 18 figures, submitted to Phys. Rev.

    SEARCH FOR SLOWLY MOVING MAGNETIC MONOPOLES WITH THE MACRO DETECTOR

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    A search for slowly moving magnetic monopoles in the cosmic radiation was conducted from October 1989 to November 1991 using the large liquid scintillator detector subsystem of the first supermodule of the MACRO detector at the Gran Sasso underground laboratory. The absence of candidates established an upper limit on the monopole flux of 5.6 x 10(-15) cm-2 sr-1 s-1 at 90% confidence level in the velocity range of 10(-4) less than or similar to beta < 4 x 10(-3). This result places a new constraint on the abundance of monopoles trapped in our solar system

    Giovani in scene di cura

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    Questo articolo intende introdurre alla lettura di una ricca sezione monografica dedicata a profili di giovani speciali, ‘non standard’ come dice il titolo: giovani che si muovono tra azione di cura prestata (young caregiver) e azione di cura ricevuta (care recipient/care leaver). Si tratta di bambini e adolescenti che si trovano a fronteggiare circostanze avverse, in un caso dovendo prestare troppo precocemente e intensamente aiuto a familiari bisognosi di cura; nell’altro trovandosi ai confini del consolidato sistema di tutela o costretti a fuoriuscirne e a gestire la propria vita di adolescenti come se fossero già adulti. L’articolo si compone di successivi cinque paragrafi. Il primo prova a definire cosa si intende per giovani, non solo dal punto di vista anagrafico, ma soprattutto in base alla lettura delle loro caratteristiche fornita dagli studi sociologici, psicologici e pedagogici. Il paragrafo successivo si presenta come una riflessione sulla logica che informa le politiche giovanili, soprattutto quelle rivolte agli adolescenti in cui si pone la questione del difficile equilibrio tra diritto alla protezione e diritto alla partecipazione. Il terzo ricostruisce l’identikit sia del giovane caregiver sia del care recipient/ leaver, evidenziandone punti di vicinanza e punti di lontananza. Il paragrafo seguente ripercorre il fil rouge della sezione monografica, entrando brevemente nel merito di ognuno dei sei articoli che la compongono. Infine, il paragrafo conclusivo riflette su tre temi principali che emergono dalla lettura dei sei articoli, ossia a) la difficoltà di far dialogare insieme il diritto alla tutela e quello alla partecipazione; b) la ‘difficoltà multidimensionale’ di fronte alla quale si trovano gli adulti quando interagiscono con questi giovani e c) la carenza di solide basi informative per supportare operatori sociale e policy maker in relazione all’entità del caregiving e del care leaving riferiti a soggetti giovani.The article aims at introducing the reading of a monographic section dedicated to different empirical studies on young (children, adolescents or young adults) caregiv- ers, young recipients and care leavers in the Italian context. They are faced with ad- verse circumstances, on the one hand because they have to provide too early and too much help to family members in need of care; on the other hand, because they find themselves on the borderline of the established care system or forced to leave it and manage their own lives as if they were already adults. Here we outline the con- tours of the problems faced by young people in contemporary societies and clarify what are the elements that distinguish them when they are involved in problems of care. Referring to the contributions in the monographic section, open questions are identified and some paths of action and further research are highlighted. Keywords: Young People, Caregiving, Care Leavers, Care Recipients, Social Policies

    C’era una volta l’Università? Analisi longitudinale delle carriere degli studenti prima e dopo la “grande Riforma”

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    Da alcuni decenni l’università italiana è rappresentata come un sistema attraversato da una profonda contraddizione. Temi quali l’abbandono, il ritardo negli studi, il basso numero di laureati e il carente collegamento con il mondo del lavoro ricorrono frequentemente nel dibattito politico, sociale e accademico del nostro Paese. Altrettanto frequentemente, però, viene sottolineata la capacità da parte dei nostri atenei di formare laureati preparati, capaci, dotati di profili formativi solidi, in grado di competere almeno alla pari, se non da una posizione di superiorità, con i colleghi laureati in altri Paesi. Le aree problematiche riguardano, da un lato, l’efficienza (interpretata come rapporto tra risultati ottenuti e costi sostenuti) e, dall’altro, l’efficacia (intesa come raggiungimento degli obiettivi prefissati). Entrambe le dimensioni dipendono, con modalità differenti e a diversi livelli di responsabilità, sia dalle logiche del sistema universitario sia dalle politiche in materia di istruzione e formazione, nonché dall’assetto economico e dalla capacità di assorbimento del mer-cato del lavoro. Questa contraddizione appariva costitutiva di quello che oggi viene definito Vecchio ordinamento didattico. Al fine di eliminare tale stato di contraddittorio equilibrio, aumentando l’efficienza e almeno mantenendo l’efficacia, il sistema universitario italiano è stato investito negli ultimi tre lustri da radicali riforme, tra le quali la più importante per contenuti e potenziale impatto innovativo è stata introdotta dal Dm 509/1999. Il quadro ricostruibile a livello nazionale è bene rappresentato dalla situazione del più grande ateneo italiano: la Sapienza Università di Roma. Il programma di ricerca i cui risultati sono qui presentati ha, infatti, permesso di evidenziare come, a una situazione piuttosto critica nei primi anni ’90, sia seguito nel primo Ateneo romano un periodo di importanti cambiamenti. La stagione positiva della Sapienza, però, non coincide, come si potrebbe immaginare, con l’avvento della Riforma, bensì risulta anticipata di qualche anno (nel volume si parla di effetto di retroazione del Dm 509/1999). Inoltre, questo periodo di relativa prosperità è destinato a durare poco

    Continuity and Innovation in Higher Education. A secondary analysis of longitudinal data

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    The paper presents the results of a research that aims at the evaluation of Italian Higher Education reform policies and their implementation outcomes. It is a secondary analysis of longitudinal administrative data for a description of the phenomena of late performance and student dropping out. Sapienza University of Rome was identified as an ideal context for this analysis, due to its dimensions and complexity, and because of its variety of scientific and educational areas of academic training. The research focuses on the cohorts of students enrolled in specific key moments before (from academic year 1991/1992 to 2000/2001) and after the reform (from 2001/2002 to 2012/2013). The assumption behind this research design is that the longitudinal perspective is able to provide an accurate frame of students’ curricula and to reconstruct the potentially relevant events to the outcomes of their university career. Longitudinal panel studies monitor the same generation of students over several years; consequently, these strategies are able to offer quite more accurate results because they reduce the risks related to the utilization of aggregate data. From a methodological point of view, we came to the creation of longitudinal multidimensional models of the students’ careers, aiming at identifying the “mechanisms” through which from an initial state t0, a subsequent state t1 is generated. In addition, we created two indexes related to the measurement of the distance in years and university credits to graduate according to the speed of achievement of credits maintained until that moment.The paper presents the results of a research that aims at the evaluation of Italian Higher Education reform policies and their implementation outcomes. It is a secondary analysis of longitudinal administrative data for a description of the phenomena of late performance and student dropping out. Sapienza University of Rome was identified as an ideal context for this analysis, due to its dimensions and complexity, and because of its variety of scientific and educational areas of academic training. The research focuses on the cohorts of students enrolled in specific key moments before (from academic year 1991/1992 to 2000/2001) and after the reform (from 2001/2002 to 2012/2013). The assumption behind this research design is that the longitudinal perspective is able to provide an accurate frame of students’ curricula and to reconstruct the potentially relevant events to the outcomes of their university career. Longitudinal panel studies monitor the same generation of students over several years; consequently, these strategies are able to offer quite more accurate results because they reduce the risks related to the utilization of aggregate data. From a methodological point of view, we came to the creation of longitudinal multidimensional models of the students’ careers, aiming at identifying the “mechanisms” through which from an initial state t0, a subsequent state t1 is generated. In addition, we created two indexes related to the measurement of the distance in years and university credits to graduate according to the speed of achievement of credits maintained until that moment
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