3,271 research outputs found

    NA60 results on phi production in the hadronic and leptonic channels in In-In collisions at 158 GeV

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    The NA60 experiment at the CERN SPS studied phi meson production in In-In collisions at 158 A GeV via muon and kaon decay channels. Results in the hadronic channel are presented for the first time. These are discussed in the framework of the so-called phi puzzle through the comparison with the previous NA60 measurements in the muon channel. The yield and inverse m_T slopes observed in the two channels are compatible within errors, showing that the large discrepancies seen in Pb-Pb collisions between NA50 (muon pairs) and NA49 (kaon pairs) are not seen in the NA60 In-In data.Comment: 4 pages, 4 figures - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

    Doctoral Education in Planning and Urban Studies in Italy: what is it really for? Introduction and Editorial note

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    Data show the reduction of academic positions in Italy and invite to reconsider the role of PhD education and training as the highest level of university education. In fact, although PhDs seem to have a little advantage over Master’s level graduates in the job market, only about 10% find a job at universities. This suggests that changes in PhD programmes might be needed to match students’ needs and job market requirements. However, the opposite is also true with employers, either in the public or private sector, who should try to absorb more PhDs and use their skills and expertise. The aim of this special issue is to analyse PhD education in Italy with a focus on planning and urban studies programmes by emphasising the perspectives of PhD candidates and freshly awarded Doctors since they are generally neglected in reform processes. All authors who contributed to this special issue reflected on the same aim stressing different implications and perspectives. The topics investigated are: matching between students’ expectations and institutional goals, the international mobility of PhD candidates, experiences of international PhD students in Italy, and the evolution of two of the oldest PhD programmes in planning in Italy at Sapienza, Rome and Iuav, Venice

    Gain assisted nanocomposite multilayers with near zero permittivity modulus at visible frequencies

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    We have fabricated a layered nano-composite by alternating metal and gain medium layers, the gain dielectric consisting of a polymer incorporating optically pumped dye molecules. Exploiting an improved version of the effective medium theory, we have chosen the layers thicknesses for achieving a very small value of the real part of the permittivity epsilon_\| (parallel to the layers plane) at a prescribed visible wavelength. From standard reflection-transmission experiments on the optically pumped sample we show that, at a visible wavelength, both the real and the imaginary parts of the permittivity epsilon_\ attain very small values and we measure | \epsilon_\| | = 0.04 at lambda = 604 nm, amounting to a 21.5-percent decrease of the minimum | \epsilon_\| | in the absence of optical pumping. Our investigation thus proves that a medium with a dielectric permittivity with very small modulus, a key condition which should provide efficient subwavelength optical steering, can be actually synthesized.Comment: Submitted for publication on Applied Physics Letter

    One-dimensional chirality: strong optical activity in epsilon-near-zero metamaterials

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    We suggest that electromagnetic chirality, generally displayed by 3D or 2D complex chiral structures, can occur in 1D patterned composites whose components are achiral. This feature is highly unexpected in a 1D system which is geometrically achiral since its mirror image can always be superposed onto it by a 180 deg rotation. We analytically evaluate from first principles the bi-anisotropic response of multilayered metamaterials and we show that the chiral tensor is not vanishing if the system is geometrically one-dimensional chiral, i.e. its mirror image can not be superposed onto it by using translations without resorting to rotations. As a signature of 1D chirality, we show that 1D chiral metamaterials support optical activity and we prove that this phenomenon undergoes a dramatic non-resonant enhancement in the epsilon-near-zero regime where the magneto-electric coupling can become dominant in the constitutive relations.Comment: 5 pages, 4 figures. Accepted for publication on Physical Review Letter

    Beauty physics with heavy ions and prospects

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    Heavy flavours are generally considered one of the fundamental probes of the Quark-Gluon Plasma (QGP), the state of matter in which partons are deconfined, that can be created in relativistic heavy-ion collisions. Due to their large mass, heavy quarks are predominantly produced in hard scattering processes during the early stages of the collision lie Open heavy flavour measurements may probe the energy density of the system by means of the energy loss through elastic scatterings and gluon radiation. The radiative energy loss is predicted by QCD to be larger for gluons than for quarks, and light quark energy loss should be larger than that for heavy quarks due to the dead cone effect. The measurement of the yield of beauty hadrons can therefore shed light on the energy loss mechanism and on the mass hierarchy. Quarkonia are another crucial probe of the QGP. They can melt in the medium due to color screening at a temperature which increases with the binding energy of the system, thus acting as a probe of the QGP temperature. Bottomonia are of particular interest in this respect, since they can provide a clear suppression pattern. Beauty and bottomonia measurements in heavy-ion collisions at the LHC are reviewed. Results based on semi-leptonic decays of charm and beauty hadrons, non-prompt J/y from B decays and b-tagged jets in Pb-Pb collisions are discussed, as well as the measurements of i suppression at mid and forward rapidity provided by the CMS and ALICE experiments. Cold nuclear matter effects are investigated through the measurements in p-Pb collisions

    Work addiction among bank employees in Italy: A contribution to validation of the Bergen Work Addiction Scale with a focus on measurement invariance across gender and managerial status

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    This study contributes to the validation of the Bergen Work Addiction Scale (BWAS) in the Italian context, with a focus on measurement invariance across gender and managerial status. The BWAS is a consolidated measure of work addiction (WA) anchored in general addiction theory that comprises seven items representing the core addiction components. Participants were 8419 bank workers (37.7% women, 12.9% managers) who completed a self-report questionnaire including the Italian version of the BWAS (BWAS-I) and the Dutch Work Addiction Scale, as well as measures of work engagement, perfectionism, workload, psycho-physical symptoms, work–family conflict, and job satisfaction. Results confirmed the single-factor structure of the BWAS-I. Partial scalar invariance held across gender and managerial status, meaning that most—but not all—item intercepts were equivalent across different populations. Furthermore, the BWAS-I showed adequate convergent, discriminant, criterion-related, and incremental validity. This study showed that the BWAS-I is a valuable instrument that can be used by researchers and practitioners to assess WA in the Italian context.publishedVersio

    Non-surgical treatment of hidradenitis suppurativa: the role of cryotherapy

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    Background. Hidradenitis suppurativa is a chronic and recurrent inflammatory disease with a great impact on a patient's quality of life, due to the painful involvement of very sensitive areas, such as the groin, mammary area, and genitals, with malodourous discharge. Multiple treatment options are available; however, no single treatment is effective for all patients, and usually, a combination of medical therapy with various surgical and physical procedures is provided. Cryotherapy is not a routine technique to treat HS, although usually available in the majority of medical clinics, and is cheaper than laser and surgical treatments. The aim of this study was to evaluate the effectiveness of cryotherapy on persistent HS nodules, to reduce the burden of local disease. Materials and methodsRetrospective observational study in all patients treated with liquid nitrogen cryotherapy for persistent nodules of hidradenitis suppurativa in the last 2 years, with at least 6 months of follow-up after the procedure. Disease severity was assessed with Hurley staging and sonographic staging according to SOS-HS (18 MHz probe, Esaote-MyLab (TM)). The results were scored with a 0-3 points scale, as complete remission (3), partial response (2 to 1), or no response (0), after one session of treatment. Local cleansing and antiseptic treatment after the procedure was the same as previously performed in each patient, not to influence recovery. ResultsIn total, 23 patients were included, with a total of 71 persistent nodules treated with a single cryotherapy session. The treatment has been effective in 63 out of 71 nodules treated (88.7%), and the patients attested that they recommend the treatment, the discomfort during recovery was minimal, and the management was not different from daily routine. Persistence was considered as having a failure rate (11.3% overall) and occurred in 7.5% of the nodules of the axillary region, 18.2% on the groin, and 11.2% for nodules of the gluteal region. ConclusionCryotherapy is a simple and effective procedure for the treatment of persistent nodules of HS not responding to medical therapy, and it is a valid alternative to local surgery or laser ablation
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