Seven views on approximate convexity and the geometry of K-spaces

As in Hokusai's series of paintings "Thirty six views of mount Fuji" in which mount Fuji's is sometimes scarcely visible, the central topic of this paper is the geometry of $K$-spaces although in some of the seven views presented $K$-spaces are not easily visible. We study the interplay between the behaviour of approximately convex (and approximately affine) functions on the unit ball of a Banach space and the geometry of Banach K-spaces.Comment: 2 figure

Activation of MHD reconnection on ideal timescales

Magnetic reconnection in laboratory, space and astrophysical plasmas is often invoked to explain explosive energy release and particle acceleration. However, the timescales involved in classical models within the macroscopic MHD regime are far too slow to match the observations. Here we revisit the tearing instability by performing visco-resistive two-dimensional numerical simulations of the evolution of thin current sheets, for a variety of initial configurations and of values of the Lunquist number $S$, up to $10^7$. Results confirm that when the critical aspect ratio of $S^{1/3}$ is reached in the reconnecting current sheets, the instability proceeds on ideal (Alfv\'enic) macroscopic timescales, as required to explain observations. Moreover, the same scaling is seen to apply also to the local, secondary reconnection events triggered during the nonlinear phase of the tearing instability, thus accelerating the cascading process to increasingly smaller spatial and temporal scales. The process appears to be robust, as the predicted scaling is measured both in inviscid simulations and when using a Prandtl number $P=1$ in the viscous regime.Comment: Accepted for publication in Plasma Physics and Controlled Fusio

Reply to Comment on ``Can gravity distinguish between Dirac and Majorana neutrinos?''

This is a reply to a comment (gr-qc/0610098) written by Nieves and Pal about our paper (gr-qc/0605153) published in Phys. Rev. Lett. 97, 041101 (2006).Comment: 1 page, no figures, REVTe

The new “Vegetation map of Sicily (Italy)”: a synthetic overview of the distribution of European habitats on the territory.

The new "Vegetation map of Sicily (Italy)", recently published (Gianguzzi, Papini & Cusimano, 2015), shows also a synthetic overview of the distribution of European habitats in the territory; the study area has been extended to small islands circum-Sicilian (archipelago of the Aeolian; Aegadian, Pelagie Ustica and Pantelleria islands), for a total area of 25,703 km2. Our work allowed to resume the knowledge status of the phytosociological studies on vegetation carried out and to identify the actual plant landscape of the region; the map was compiled in a Geographical Information Systems (GIS) environment, in order to produce a cartographic representation in 1:10,000 scale (reduced to a 1:250,000 scale). At the reference scale 36 phytocoenotic types are represented, 16 of which related to European habitats of zonal vegetation (Mediterranean maquis, Quercus ilex woods, Quercus suber woods, Castanea sativa woods, Quercus pubescens deciduous woods, mesophilous deciduous woods, Fagus sylvatica woods, Betula aetnensis woods, woods dominated by woody gymnosperms, forest edge shrubs, orophilous pulvinate shrubs, shrublands and garrigues on substrates of carbonate nature and on substrates of siliceous nature, Ampelodesmos mauritanicus grasslands, mesophilous and sub-hygrophilous grasslands and pastures), 11 related to azonal vegetation (riparian vegetation, psammophilous herbaceous vegetation, chasmo-halophitic vegetation, etc.) and 9 related to anthropogenic vegetation (arable lands and extensive herbaceous crops, vineyards, olive groves and dry cultivation mosaics, hazelnut groves, irrigated citrus groves and orchards, greenhouses, built-up areas). Gianguzzi L., Papini F., Cusimano D., 2015 – Phytosociological survey vegetation map of Sicily (Mediterranean region). – Journal of Maps:1-7 (http://dx.doi.org/10.1080/17445647.2015.1094969)

Phytosociological survey vegetation map of Sicily (Mediterranean region)

We present the results of a study aimed at developing a vegetation map of Sicily (Italy) including the smaller circum-Sicilian islands, for an area of approximately 25,703 km2. The work is a synthesis of studies carried out in accordance with the survey methodology of phytosociology in the last 40 years over the whole study area. The vegetation map of Sicily was compiled in a Geographical Information Systems (GIS) environment, in order to produce a cartographic representation at a scale of 1:10,000 (reduced to a scale of 1:250,000). The physiognomic-structural characteristics of the plant landscape of Sicily are analyzed, providing a general and, at the same time, detailed overview of the phytocoenotic aspects represented on the territory, as well as of the relative bibliographic references. At the reference scale, 36 types are represented, 16 of which are related to zonal vegetation (Mediterranean maquis, Quercus ilex woods, Quercus suber woods, Castanea sativa woods, Quercus pubescens deciduous woods, mesophilous deciduous woods, Fagus sylvatica woods, Betula aetnensis woods, woods dominated by woody gymnosperms, forest edge shrubs, orophilous pulvinate shrubs, shrublands and garrigues, Ampelodesmos mauritanicus grasslands, mesophilous and sub-hygrophilous grasslands and pastures), 11 are related to azonal vegetation (riparian, psammophilous herbaceous, chasmo-halophitic, etc.) and 9 are related to anthropogenic vegetation (arable lands and extensive herbaceous crops, vineyards, olive groves and dry cultivation mosaics, hazelnut groves, irrigated citrus groves and orchards, greenhouses, built-up areas)

Methodological shortcomings of wrist-worn heart rate monitors validations

Wearable sensor technology could have an important role for clinical research and in delivering health care. Accordingly, such technology should undergo rigorous evaluation prior to market launch, and its performance should be supported by evidence-based marketing claims. Many studies have been published attempting to validate wrist-worn photoplethysmography (PPG)-based heart rate monitoring devices, but their contrasting results question the utility of this technology. The reason why many validations did not provide conclusive evidence of the validity of wrist-worn PPG-based heart rate monitoring devices is mostly methodological. The validation strategy should consider the nature of data provided by both the investigational and reference devices. There should be uniformity in the statistical approach to the analyses employed in these validation studies. The investigators should test the technology in the population of interest and in a setting appropriate for intended use. Device industries and the scientific community require robust standards for the validation of new wearable sensor technology