898 research outputs found

    Ripensare la documentazione archeologica: nuovi percorsi per la ricerca e la comunicazione

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    While the application of computer technology to archaeology has been characterized by numerous experiments, there has been no specific attempt to standardize processes. Archaeologists operating in the field seem to privilege “ad hoc” solutions in which the computer has been more or less actively featured. Without any pretence of presenting a model, this paper describes a series of field experiments conducted by the archaeology team of the University of Foggia, and reflections based on the growing use of computers in the various phases of our research. Beyond this, we hope to show the necessity and importance of reaching some kind of consensus regarding methodology and technological innovation. Computer technology has allowed us to rethink the process of documentation by introducing important innovations in all phases of research, from recovery of data to analysis, interpretation and reconstruction right through to the dissemination of results

    Optical feedback radiation forces: Intracavity optical trapping with feedback-locked diode lasers

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    We demonstrate a novel mechanism for optical tweezing, where a trapped particle dynamically alters an external cavity quality factor, reduceing the average intensity and photodamage, even employing low-numerical aperture lenses and wide fields-of-view. © OSA 2012

    The Impact of Quarantine and Physical Distancing Following COVID-19 on Mental Health : Study Protocol of a Multicentric Italian Population Trial

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    The COVID-19 pandemic and its related containment measures-mainly physical distancing and isolation-are having detrimental consequences on the mental health of the general population worldwide. In particular, frustration, loneliness, and worries about the future are common reactions and represent well-known risk factors for several mental disorders, including anxiety, affective, and post-traumatic stress disorders. The vast majority of available studies have been conducted in China, where the pandemic started. Italy has been severely hit by the pandemic, and the socio-cultural context is completely different from Eastern countries. Therefore, there is the need for methodologically rigorous studies aiming to evaluate the impact of COVID-19 and quarantine measures on the mental health of the Italian population. In fact, our results will help us to develop appropriate interventions for managing the psychosocial consequences of pandemic. The "COVID-IT-mental health trial" is a no-profit, not-funded, national, multicentric, cross-sectional population-based trial which has the following aims: a) to evaluate the impact of COVID-19 pandemic and its containment measures on mental health of the Italian population; b) to identify the main areas to be targeted by supportive long-term interventions for the different categories of people exposed to the pandemic. Data will be collected through a web-platform using validated assessment tools. Participants will be subdivided into four groups: a) Group 1-COVID-19 quarantine group. This group includes the general population which are quarantined but not isolated, i.e., those not directly exposed to contagion nor in contact with COVID-19+ individuals; b) Group 2-COVID-19+ group, which includes isolated people directly/indirectly exposed to the virus; c) Group 3-COVID-19 healthcare staff group, which includes first- and second-line healthcare professionals; d) Group 4-COVID-19 mental health, which includes users of mental health services and all those who had already been diagnosed with a mental disorder. Mental health services worldwide are not prepared yet to manage the short- and long-term consequences of the pandemic. It is necessary to have a clear picture of the impact that this new stressor will have on mental health and well-being in order to develop and disseminate appropriate interventions for the general population and for the other at-risk groups

    Measurement of W Polarisation at LEP

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    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

    Search for Anomalous Couplings in the Higgs Sector at LEP

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    Anomalous couplings of the Higgs boson are searched for through the processes e^+ e^- -> H gamma, e^+ e^- -> e^+ e^- H and e^+ e^- -> HZ. The mass range 70 GeV < m_H < 190 GeV is explored using 602 pb^-1 of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies sqrt(s)=189-209 GeV. The Higgs decay channels H -> ffbar, H -> gamma gamma, H -> Z\gamma and H -> WW^(*) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, db, Delta(g1z), Delta(kappa_gamma) and xi^2 are derived as well as limits on the H -> gamma gamma and H -> Z gamma decay rates

    Measurement of W Polarisation at LEP

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    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \pm 0.027 \pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation

    Bose-Einstein Correlations of Neutral and Charged Pions in Hadronic Z Decays

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    Bose-Einstein correlations of both neutral and like-sign charged pion pairs are measured in a sample of 2 million hadronic Z decays collected with the L3 detector at LEP. The analysis is performed in the four-momentum difference range 300 MeV < Q < 2 GeV. The radius of the neutral pion source is found to be smaller than that of charged pions. This result is in qualitative agreement with the string fragmentation model

    Z Boson Pair-Production at LEP

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    Events stemming from the pair-production of Z bosons in e^+e^- collisions are studied using 217.4 pb^-1 of data collected with the L3 detector at centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events with b quarks is also investigated. Combining these events with those collected at lower centre-of-mass energies, the Standard Model predictions for the production mechanism are verified. In addition, limits are set on anomalous couplings of neutral gauge bosons and on effects of extra space dimensions

    Neutral-Current Four-Fermion Production in e+e- Interactions at LEP

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    Neutral-current four-fermion production, e+e- -> ffff is studied in 0.7/fb of data collected with the L3 detector at LEP at centre-of-mass energies root(s)=183-209GeV. Four final states are considered: qqvv, qqll, llll and llvv, where l denotes either an electron or a muon. Their cross sections are measured and found to agree with the Standard Model predictions. In addition, the e+e- -> Zgamma* -> ffff process is studied and its total cross section at the average centre-of-mass energy 196.6GeV is found to be 0.29 +/- 0.05 +/- 0.03 pb, where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model prediction of 0.22 pb. Finally, the mass spectra of the qqll final states are analysed to search for the possible production of a new neutral heavy particle, for which no evidence is found
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