3D FEM and DEM Analyses of Underground Openings in Competent Rock Masses

The paper is aimed at comparing the results of numerical analyses of underground openings in competent rock masses like the Carrara Marble (Italy) by considering a real and well documented case study. More specifically, 3D FEM and DEM analyses were carried out on a rock-mass model interested by two faults and three sets of discontinuities. The geometrical model is representative of deep underground openings where spalling-cracks and rock bursts can occur. PLAXIS 3D and 3DEC were used for the analyses. Intact rock and rock mass characterization of Carrara Marble was inferred from available technical literature. The analysis results were compared in terms of principal stresses and displacements in a number of monitoring points around the opening. The main practical interest is to find out a reliable approach for evaluating the stability of very large openings in a competent rock mass like Carrara marble. For such a purpose, a number of available in-situ stress measurements were used

Overtourism: A literature review to assess implications and future perspectives

Overtourism is an emerging concept facing the world's main tourist destinations. The growth that tourism has undergone in recent decades is of two different types. On the one hand, the development of new technologies and the creation of low-cost airline carriers have increased tourism levels, leading to growth even in emerging economies. On the other hand, uncontrolled demand alongside a concentration of tourism in particular destinations impact negatively both territories and local communities. The problems caused in some destinations by the increasing, ongoing growth in tourism have created the issue of "overtourism," which is assuming an increasing significance in the literature. This paper contributes to the literature by providing an exploratory study with which to better understand the origins of overtourism, its implications, and predicted future perspectives in respect to the issue. Examination of the new evidence presented here contributes to the expanding knowledge of particular problems of tourism development

On the Reconstruction of Cavities in a Nonlinear Model Arising from Cardiac Electrophysiology

In this paper, we deal with the problem of determining perfectly insulating regions (cavities) from one boundary measurement in a nonlinear elliptic equation arising from cardiac electrophysiology. Based on the results obtained in [9] we propose a new reconstruction algorithm based on Gamma-convergence. The relevance and applicability of this approach are then shown through several numerical experiments

Intermittency in the large N-limit of a spherical shell model for turbulence

A spherical shell model for turbulence, obtained by coupling $N$ replicas of the Gledzer, Okhitani and Yamada shell model, is considered. Conservation of energy and of an helicity-like invariant is imposed in the inviscid limit. In the $N \to \infty$ limit this model is analytically soluble and is remarkably similar to the random coupling model version of shell dynamics. We have studied numerically the convergence of the scaling exponents toward the value predicted by Kolmogorov theory (K41). We have found that the rate of convergence to the K41 solution is linear in 1/N. The restoring of Kolmogorov law has been related to the behaviour of the probability distribution functions of the instantaneous scaling exponent.Comment: 10 pages, Latex, 3 Postscript figures, to be published on Europhys. Let

Female preference for male color is necessary and sufficient for assortative mating in 2 cichlid sister species

One fish, two fish, red fish, blue fish: in two cichlid fish species beauty is in the eye of the beholder. Females choose mates based on colour, blue or red, and chemical cues but only colour triggers divergent female preferences. Reliance on one prime male characteristic may have facilitated speciation in this species-pair, but in murky waters the opportunity for visual communication is dim and the fate of the two species uncertai

Hydrogeochemistry of Magra Valley (Italy) Aquifers: Geochemical Background of an Area Investigated for Seismic Precursors

AbstractWe present the results of a hydrogeochemical survey of 111 springs and wells from Magra Valley, a seismic area located in northern Tuscany, Italy. This survey was aimed at defining the geochemical background and the underground fluid circulation scheme of an area currently investigated for earthquake precursory phenomena, with the final goal of identifying a suitable location for installation of a continuous automatic monitoring station for the remote control of hydrogeochemical parameters. Six springs of the project were identified suitable for the purpose, and the Equi Na-Cl-type spring emerged as the best candidate for the installation of a monitoring station

Esthesioneuroblastoma is not a member of the primitive peripheral neuroectodermal tumour-Ewing’s group

Esthesioneuroblastoma (ENB) is a rare, site-specific, locally aggressive neuronal malignancy so far thought to belong to primitive peripheral neuroectodermal tumour-Ewing's tumour (pPNETs-ETs). Its anatomical location, in addition to morphologic, immunophenotypic and ultrastructural features, suggests its origin in the neuronal or neuroendocrine cells of the olfactory epithelium. However, the cytogenetic and molecular data currently available appear controversial on the presence of the typical translocation t(11;22)(q24;q12) and of trisomy 8, chromosomal changes that characterize the tumours belonging to the pPNETs-ETs. Herein we have analysed five ENB tumour specimens for trisomy 8 by fluorescence in situ hybridization (FISH), for the presence of EWS gene rearrangements by FISH, reverse transcription polymerase chain reaction and Southern blot analyses, as well as for the expression of the Ewing sarcoma-associated MIC2 antigen by immunohistochemistry. Neither EWS/FLI-I, EWS/ERG and EWS/FEV fusion genes nor MIC2 expression were found in any tumour, whereas trisomy 8 was found in one case only. Moreover, DNA from three cases analysed by Southern blot did not show EWS gene rearrangements. Our results support the evidence that ENB is not a member of the pPNETs-ETs. © 1999 Cancer Research Campaig

The Gap between Tobacco Treatment Guidelines, Health Service Organization, and Clinical Practice in Comprehensive Cancer Centres

Smoking cessation is necessary to reach a higher quality of life, and, for a cancer patient, it represents an important step in improving the outcome of both prognosis and therapy. Being a cancer patient addicted to nicotine may be a critical situation. We conducted a survey to monitor how many comprehensive cancer centres in Italy have an outpatient smoker clinic and which kinds of resources are available. We also inquired about inpatient services offering psychological and pharmacological support for smoking cessation, reduction, or care of acute nicotine withdrawal symptoms. What we have witnessed is a significant gap between guidelines and services. Oncologists and cancer nurses are overscheduled, with insufficient time to engage in discussion on a problem that they do not consider directly related to cancer treatment. Furthermore, smoking habits and limited training in tobacco dependence and treatment act as an important barrier and lead to the undervaluation of smokers' needs

IGFBP7: an oncosuppressor gene in thyroid carcinogenesis

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