Insights into the explosive eruption history of the Campanian volcanoes prior to the Campanian Ignimbrite eruption

The Campanian Volcanic Zone (CVZ) comprises multiple active volcanoes and includes the highly productive Campi Flegrei and Ischia caldera systems. These caldera volcanoes have produced probably the largest eruptions in Europe in the past 200 ka, such as the Monte Epomeo Green Tuff (MEGT; Ischia) at ca. 56 ka and the Campanian Ignimbrite (CI; Campi Flegrei) at ca. 40 ka, which form widespread isochrons across the Mediterranean region. These closely-spaced volcanic centres erupt phonolitic to trachytic glass compositions that are similar, and thus it can be challenging to correlate tephra deposits to specific volcanic sources. Here we present a detailed tephrostratigraphy for pre-CI eruption activity using the units preserved within a sequence at the coastal Acquamorta outcrop, on the western side of the CI caldera rim. Both the MEGT and CI units are present in the section, and they bracket twelve eruption units that were logged and sampled. New major and trace element glass chemistry data have been acquired for these Acquamorta tephra deposits. Three eruption deposits from Ischia and nine from Campi Flegrei are identified, which helps constrain the tempo of volcanic activity of these centres between the large caldera-forming eruptions. The three Ischia tephra deposits between the MEGT and the CI are indistinguishable based on both major and trace element glass chemistry and cannot be correlated to a specific or known eruption in this interval, such as the Schiappone tephra. The compositional variations between the Campi Flegrei eruptions reveal temporal shifts in the composition of the tephra deposits that reflect changes in the magmatic system prior to the CI eruption. These deposits indicate that there were at least nine eruptions at Campi Flegrei within 16 ka of the enormous CI eruption, and suggest that there was no significant period of repose before the caldera generating eruption

An elementary approach to rigorous approximation of invariant measures

We describe a framework in which is possible to develop and implement algorithms for the approximation of invariant measures of dynamical systems with a given bound on the error of the approximation. Our approach is based on a general statement on the approximation of fixed points for operators between normed vector spaces, allowing an explicit estimation of the error. We show the flexibility of our approach by applying it to piecewise expanding maps and to maps with indifferent fixed points. We show how the required estimations can be implemented to compute invariant densities up to a given error in the $L^{1}$ or $L^\infty$ distance. We also show how to use this to compute an estimation with certified error for the entropy of those systems. We show how several related computational and numerical issues can be solved to obtain working implementations, and experimental results on some one dimensional maps.Comment: 27 pages, 10 figures. Main changes: added a new section in which we apply our method to Manneville-Pomeau map

Strontium ranelate reduces the risk of vertebral fracture in young postmenopausal women with severe osteoporosis

Early osteoporotic fractures have a great impact on disease progression, the first fracture being a major risk factor for further fractures. Strontium ranelate efficacy against vertebral fractures is presently assessed in a subset of women aged 50-65 years

Viabilidade do emprego de cinza de casca de arroz natural em concreto estrutural. Parte I: propriedades mecânicas e microestrutura

A casca de arroz, para ser utilizada em concreto estrutural, necessita de queima com temperatura controlada e de moagem prévia para lhe conferir maior reatividade pozolânica. Este trabalho discute o emprego da cinza de casca de arroz (CCA) natural e residual, queimada sem controle de temperatura e sem moagem, de forma a simplificar o processamento da CCA e ampliar seu uso em concretos convencionais, em locais próximos onde é produzido, Estudou-se a sequência de colocação e o tempo de mistura dos materiais na betoneira, para obtenção do melhor desempenho da automoagem no tambor. Foram testadas misturas de concreto de referência com cimento Portland e com 15% e 25% de substituição de cimento, em massa, por CCA natural e moída. Foram realizados ensaios de resistência à compressão axial, tração por compressão diametral, módulo de elasticidade, retração total, porosimetria por intrusão de mercúrio, água quimicamente combinada e MEV. A análise dos resultados revela a viabilidade da substituição de 15% de cimento por CCA natural, com perda não significativa de resistência à tração e módulo de elasticidade a 28 dias, com recuperação total a 91 dias, para concretos com resistências à compressão entre 25 MPa e 40 MPa

Life in harsh environments : carabid and spider trait types and functional diversity on a debris-covered glacier and along its foreland

1. Patterns of species richness and species assemblage composition of ground-dwelling arthropods in primary successions along glacier forelands are traditionally described using a taxonomic approach. On the other hand, the functional trait approach could ensure a better characterisation of their colonisation strategies in these types of habitat. 2. The functional trait approach was applied to investigate patterns of functional diversity and life-history traits of ground beetles and spiders on an alpine debris-covered glacier and along its forefield in order to describe their colonisation strategies. 3. Ground beetles and spiders were sampled at different successional stages, representing five stages of deglaciation. 4. The results show that the studied glacier hosts ground beetle and spider assemblages that are mainly characterised by the following traits: walking colonisers, ground hunters and small-sized species. These traits are typical of species living in cold, wet, and gravelly habitats. The diversity of functional traits in spiders increased along the succession, and in both carabids and spiders, life-history traits follow the \u2018addition and persistence model\u2019. Accordingly, there is no turnover but there is an addition of new traits and a variation in their proportion within each species assemblage along the succession. The distribution of ground beetles and spiders along the glacier foreland and on the glacier seems to be driven by dispersal ability and foraging strategy. 5. The proposed functional approach improves knowledge of the adaptive strategies of ground-dwelling arthropods colonising glacier surfaces and recently deglaciated terrains, which represent landforms quickly changing due to global warming

Guidelines for the diagnosis, prevention and management of osteoporosis

Osteoporosis poses a significant public health issue. National Societies have developed Guidelines for the diagnosis and treatment of this disorder with an effort of adapting specific tools for risk assessment on the peculiar characteristics of a given population. The Italian Society for Osteoporosis, Mineral Metabolism and Bone Diseases (SIOMMMS) has recently revised the previously published Guidelines on the diagnosis, riskassessment, prevention and management of primary and secondary osteoporosis. The guidelines were first drafted by a working group and then approved by the board of SIOMMMS. Subsequently they received also the endorsement of other major Scientific Societies that deal with bone metabolic disease. These recommendations are based on systematic reviews of the best available evidence and explicit consideration of cost effectiveness. When minimal evidence is available, recommendations are based on leading experts' experience and opinion, and on good clinical practice. The osteoporosis prevention should be based on the elimination of specific risk factors. The use of drugs registered for the treatment of osteoporosis are recommended when the benefits overcome the risk, and this is the case only when the risk of fracture is rather high as measured with variables susceptible to pharmacological effect. DeFRA (FRAX® derived fracture risk assessment) is recognized as a useful tool for easily estimate the long-term fracture risk. Several secondary forms of osteoporosis require a specific diagnostic and therapeutic management