390 research outputs found

    Coupling of phonons with orbital dynamics and magnetism in CuSb2O6

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOStrongly interacting phonons and orbital excitations are observed in the same energy range for CuSb2O6, unlocking a so-far unexplored type of electron-phonon interaction. An orbital wave at similar to 550 cm(-1) softens on warming and strongly interferes with a phonon at similar to 500 cm(-1), giving rise to a merged excitation of mixed character. An electronic continuum grows on warming to the orbital ordering temperature T-oo = 400 K, generating an important phonon decay channel. This direct and simultaneous observation of orbital and vibrational excitations reveals details of their combined dynamics. In addition, phonon frequency anomalies due to magnetic correlations are observed below similar to 150 K, much above the three-dimensional magnetic ordering temperature T-N(3D) = 8.5 K, confirming one-dimensional magnetic correlations along Cu-O-O-Cu linear chains in the paramagnetic state.971715FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2012/04870-7Sem informaçãoSem informaçãoAgĂȘncias de fomento estrangeiras apoiaram essa pesquisa, mais informaçÔes acesse artig

    INCIDENCE OF AMYOTROPHIC LATERAL SCLEROSIS IN SICILY: A POPULATION BASED STUDY.

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    Our objective was to investigate incidence of amyotrophic lateral sclerosis (ALS) in Sicily, southern Italy, by means of a population based study. We included people with ALS resident in fi ve Sicilian provinces, whose onset occurred in the two-year period 2005 2006 (population at 31 December 2006: 3,481,096 inhabitants). A multisource case-fi nding procedure was adopted and patients were classifi ed as affected by ALS according to revised El Escorial criteria. During the two-year surveillance period, 97 patients meeting eligibility criteria included 57 males (58.8%) and 40 females (41.2%). Crude annual incidence rate was 1.4/100,000 person years (95% CI 1.33 1.47). The incidence rate was higher in males (1.71/100,000; CI 1.61 1.81) than in females (1.11/100,000; CI 1.01 1.21). Standardized incidence rate for the total population in the 45 74-years-old age group was 3.22 (CI 3.11 3.33). Prevalence rate was 6.0/100,000 (CI 5.97 6.03), higher in males (7.1/100,000; CI 7.02 7.18) than females (4.9/100,000; CI 4.86 4.94). In conclusion, ALS rates observed in the present study are higher in males than females, with a peak of incidence at 70 years of age in both genders. These fi ndings are consistent with those of other population based European studie

    Multiple Sclerosis in the Mount Etna Region: Possible Role of Volcanogenic Trace Elements

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    Background: Trace elements have been hypothesised to be involved in the pathogenesis of Multiple Sclerosis and volcanic degassing is the major natural sources of trace elements. Both incidence of Multiple Sclerosis in Catania and volcanic activity of Mount Etna have been significantly increased during the last 30 years. Due to prevailing trade winds direction, volcanic gases from Etna summit craters are mostly blown towards the eastern and southern sectors of the volcano. Objective: To evaluate the possible association between Multiple Sclerosis and exposure to volcanogenic trace elements. Methods: We evaluated prevalence and incidence of Multiple Sclerosis in four communities (47,234 inhabitants) located in the eastern flank and in two communities (52,210 inhabitants) located in the western flank of Mount Etna, respectively the most and least exposed area to crater gas emissions. Results: A higher prevalence was found in the population of the eastern flank compared to the population of the western one (137.6/100,000 versus 94.3/100,000; p-value 0.04). We found a borderline significantly higher incidence risk during the incidence study period (1980–2009) in the population of the eastern flank 4.6/100,000 (95% CI 3.1–5.9), compared with the western population 3.2/100,000 (95% CI 2.4–4.2) with a RR of 1.41 (95% CI 0.97–2.05; p-value 0.06). Incidence risks have increased over the time in both populations reaching a peak of 6.4/100,000 in the eastern flank and of 4.4/100.000 in the western flank during 2000–2009. Conclusion: We found a higher prevalence and incidence of Multiple Sclerosis among populations living in the eastern flank of Mount Etna. According to our data a possible role of TE cannot be ruled out as possible co-factor in the MS pathogenesis. However larger epidemiological study are needed to confirm this hypothesis.Publishede742596A. Monitoraggio ambientale, sicurezza e territorioJCR Journalope

    Virtual Valcamonica: collaborative exploration of prehistoric petroglyphs and their surrounding environment in multi-user virtual reality

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    In this paper, we present a novel, multi-user, virtual reality environment for the interactive, collaborative 3D analysis of large 3D scans and the technical advancements that were necessary to build it: a multi-view rendering system for large 3D point clouds, a suitable display infrastructure and a suite of collaborative 3D interaction techniques. The cultural heritage site of Valcamonica in Italy with its large collection of prehistoric rock-art served as an exemplary use case for evaluation. The results show that our output-sensitive level-of-detail rendering system is capable of visualizing a 3D dataset with an aggregate size of more than 14 billion points at interactive frame rates. The system design in this exemplar application results from close exchange with a small group of potential users: archaeologists with expertise in rock-art and allows them to explore the prehistoric art and its spatial context with highly realistic appearance. A set of dedicated interaction techniques was developed to facilitate collaborative visual analysis. A multi-display workspace supports the immediate comparison of geographically distributed artifacts. An expert review of the final demonstrator confirmed the potential for added value in rock-art research and the usability of our collaborative interaction techniques
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