323 research outputs found

    Scanning electron microscopy of Rydberg-excited Bose-Einstein condensates

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    We report on the realization of high resolution electron microscopy of Rydberg-excited ultracold atomic samples. The implementation of an ultraviolet laser system allows us to excite the atom, with a single-photon transition, to Rydberg states. By using the electron microscopy technique during the Rydberg excitation of the atoms, we observe a giant enhancement in the production of ions. This is due to ll-changing collisions, which broaden the Rydberg level and therefore increase the excitation rate of Rydberg atoms. Our results pave the way for the high resolution spatial detection of Rydberg atoms in an atomic sample

    Polymorphous light eruption and benign summer light eruption

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    BACKGROUND/PURPOSE: Polymorphous light eruption (PLE) heterogeneity has been postulated, but the existence of benign summer light eruption (BSLE) is controversial. We studied the prevalence of the clinical patterns, criteria distinguishing BSLE from PLE, and diagnostic usefulness of phototest. METHODS: Five Italian Photodermatology Centres recruited retrospectively 346 patients with typical clinical history and/or presentation of PLE. Age, gender, skin type, family history and presence of atopy were considered. UVA and UVB MEDs and provocative phototests with UVA and UVB were obtained with a standardized procedure. Photopatch tests were applied according to the IRCDG rules. ANA were assessed by indirect immunofluorescence. RESULTS: Four criteria (predominance of women, shorter latency, uninvolvement of the face and absence of relapse during summer) identified BSLE in only 6.1% of cases. All had positive phototests, mostly with UVA. Uninvolvement of face, short latency and no seasonal relapses identified 11.7% patients, mostly with positive phototests to UVA. Short latency and no seasonal relapses in women identified 11.2% patients. Uninvolvement of face and no seasonal relapses in women identified 8.1% of patients. Uninvolvement of face and short latency in women identified 17.6% of patients. CONCLUSION: Criteria diagnosed BSLE in only a minority of patients, who were positive at phototesting, mostly with UVA

    catalase in the stratum corneum of patients with polymorphic light eruption

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    UV radiation generates reactive oxygen species, which may be involved in polymorphic light eruption. The endogenous enzymatic defense system includes catalase in the epidermis. Thirteen patients with a history of polymorphic light eruption, but free from lesions, and 13 controls were investigated from November to March. Catalase was analysed in the upper horny layer according to Colin et al.'s spectrophotometric technique. In polymorphic light eruption, catalase values were about 30% lower than in control subjects. Such deficiency was observed in patients free from the disease and not recently sun-exposed. The diminished skin catalase in irradiated polymorphic light eruption makes it possible that a longer restoration time of catalase is involved in the pathogenesis

    Disorder-enhanced phase coherence in trapped bosons on optical lattices

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    The consequences of disorder on interacting bosons trapped in optical lattices are investigated by quantum Monte Carlo simulations. At small to moderate strengths of potential disorder a unique effect is observed: if there is a Mott plateau at the center of the trap in the clean limit, phase coherence {\it increases} as a result of disorder. The localization effects due to correlation and disorder compete against each other, resulting in a partial delocalization of the particles in the Mott region, which in turn leads to increased phase coherence. In the absence of a Mott plateau, this effect is absent. A detailed analysis of the uniform system without a trap shows that the disordered states participate in a Bose glass phase.Comment: 4 pages, 4 figure

    Ethnobotanical remarks on Central and Southern Italy

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    <p>Abstract</p> <p>Background</p> <p>The present paper is a brief survey on the ethnobotanical works published by the Authors since 1981, concerning the research carried out in some southern and central Italian regions. Before Roman domination these territories were first inhabited by local people, while the southern areas were colonized by the Greeks. These different cultural contributions left certain traces, both in the toponyms and in the vernacular names of the plants and, more generally, in the culture as a whole.</p> <p>Methods</p> <p>Field data were collected through open interviews, mainly of farmers, shepherds and elderly people, born or living in these areas for a long time. Voucher specimens of collected plants are preserved in the respective herbaria of the Authors and in the herbarium of "Roma Tre" University. Important contributions have been made by several students native to the areas under consideration. A comparative analysis with local specific ethnobotanical literature was carried out.</p> <p>Results</p> <p>The paper reports several examples concerning human and veterinary popular medicine and in addition some anti-parasitic, nutraceutic, dye and miscellaneous uses are also described. Moreover vernacular names and toponyms are cited. Eight regions of central and southern Italy (particularly Latium, Abruzzo, Marche and Basilicata) were investigated and the data obtained are presented in 32 papers. Most of the species of ethnobotanical interest have been listed in Latium (368 species), Marche (274) and Abruzzo (203). The paper also highlights particularly interesting aspects or uses not previously described in the specific ethnobotanical literature.</p> <p>Conclusion</p> <p>Phyto-therapy in central and southern Italy is nowadays practised by a few elderly people who resort to medicinal plants only for mild complaints (on the contrary food uses are still commonly practised). Nowadays therapeutic uses, unlike in the past, are less closely or not at all linked to ritual aspects. Several plants deserve to be taken into consideration not only from the anthropological or cultural point of view, but also for further phyto-chemical investigation. Our studies, as well as those of other authors, try to provide an original picture of the local ethno-biodiversity.</p

    Continuous Coupling of Ultracold Atoms to an Ionic Plasma via Rydberg Excitation

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    We characterize the two-photon excitation of an ultracold gas of Rubidium atoms to Rydberg states analysing the induced atomic losses from an optical dipole trap. Extending the duration of the Rydberg excitation to several ms, the ground state atoms are continuously coupled to the formed positively charged plasma. In this regime we measure the nn-dependence of the blockade effect and we characterise the interaction of the excited states and the ground state with the plasma. We also investigate the influence of the quasi-electrostatic trapping potential on the system, confirming the validity of the ponderomotive model for states with 20≤n≤12020\leq n\leq 120

    Correlation function of weakly interacting bosons in a disordered lattice

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    One of the most important issues in disordered systems is the interplay of the disorder and repulsive interactions. Several recent experimental advances on this topic have been made with ultracold atoms, in particular the observation of Anderson localization, and the realization of the disordered Bose-Hubbard model. There are however still questions as to how to differentiate the complex insulating phases resulting from this interplay, and how to measure the size of the superfluid fragments that these phases entail. It has been suggested that the correlation function of such a system can give new insights, but so far little experimental investigation has been performed. Here, we show the first experimental analysis of the correlation function for a weakly interacting, bosonic system in a quasiperiodic lattice. We observe an increase in the correlation length as well as a change in shape of the correlation function in the delocalization crossover from Anderson glass to coherent, extended state. In between, the experiment indicates the formation of progressively larger coherent fragments, consistent with a fragmented BEC, or Bose glass.Comment: 16 pages, 8 figure

    SEEMP: A marketplace for the Labour Market

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    Employment Services are an important topic in the agenda of local governments and in the EU due to their social implications, such as sustainability, workforce mobility, workers’ re-qualification paths, training for fresh graduates and students. Many administrations started their own E-Government projects whose imitations emerge as the demand of workers mobility increases. The SEEMP system presented in this paper overcomes this issue in different ways: starting bilateral communications with near-border similar offices, building a federation of the local employment services, and merging isolate trials. The SEEMP approach relies on a distributed semantic service oriented infrastructure able to federate local projects, in order to create geographically aggregated services for employment by leveraging existing local ones. The social and technical aspects of the SEEMP project are presented, showing how the SEEMP system is integrated with National level systems

    SEEMP: A Semantic Interoperability Infrastructure for e-government services in the employment sector

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    This paper presents SEEMP, a marketplace to coordinate and integrate public and private employment services (ESs) around the EU Member States. The need for flexible collaboration in the marketplace gives rise to the issue of interoperability in both data exchange and share of services. SEEMP proposes a mixed approach that relies on the concepts of services and semantics. SEEMP approach combines Software Engineering and Semantic Web methodologies/tools in an infrastructure that allows for a meaningful service-based communication among ESs

    Epigenetic signatures of internal migration in Italy.

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    Observational studies have suggested that the risks of non-communicable diseases in voluntary migrants become similar to those in the host population after one or more generations, supporting the hypothesis that these diseases have a predominantly environmental (rather than inherited) origin. However, no study has been conducted thus far to identify alterations at the molecular level that might mediate these changes in disease risk after migration
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