The distribution of tuberculosis in Porto Alegre: analysis of the magnitude and tuberculosis-HIV coinfection

Objective Analyzing the geographical distribution of the tuberculosis (TB), its incidence and prevalence and TB-HIV coinfection in the districts of Porto Alegre from 2007 to 2011. Method An ecological, descriptive study of time series that used descriptive and geoprocessing techniques. Results In total, were recorded 3,369 incident cases and 3,998 prevalent cases of pulmonary TB. In both contexts, there was predominance of cases in males and in Caucasians. Seventeen districts showed prevalence rates above 79.2 cases/100,000 inhabitants, considering that 15 of them had incidence rates above 73.7 cases/100,000 inhabitants. The TB-HIV coinfection rates reached 67% in some districts, which is above the city average value (30%). Conclusion The distribution analysis showed that the reformulation and restructuring of policies and health services in Porto Alegre are essential

New insights in the relation between climate and slope failures at high-elevation sites

Climate change is now unequivocal; however, the type and extent of terrestrial impacts are still widely debated. Among these, the effects on slope stability are receiving a growing attention in recent years, both as terrestrial indicators of climate change and implications for hazard assessment. High-elevation areas are particularly suitable for these studies, because of the presence of the cryosphere, which is particularly sensitive to climate. In this paper, we analyze 358 slope failures which occurred in the Italian Alps in the period 2000–2016, at an elevation above 1500 m a.s.l. We use a statistical-based method to detect climate anomalies associated with the occurrence of slope failures, with the aim to catch an eventual climate signal in the preparation and/or triggering of the considered case studies. We first analyze the probability values assumed by 25 climate variables on the occasion of a slope-failure occurrence. We then perform a dimensionality reduction procedure and come out with a set of four most significant and representative climate variables, in particular heavy precipitation and short-term high temperature. Our study highlights that slope failures occur in association with one or more climate anomalies in almost 92% of our case studies. One or more temperature anomalies are detected in association with most case studies, in combination or not with precipitation (47% and 38%, respectively). Summer events prevail, and an increasing role of positive temperature anomalies from spring to winter, and with elevation and failure size, emerges. While not providing a final evidence of the role of climate warming on slope instability increase at high elevation in recent years, the results of our study strengthen this hypothesis, calling for more extensive and in-depth studies on the subject

DEM Modelling of Ice Filled Rock Joints

The research we present in this paper is part of a wider project about the modelling of climate change effects on the degradation of permafrost, with particular attention for the stability of rock masses. The presence of ice and/or mixtures of ice and granular materials in rock joints has a big impact on the shear resistance of joints and on the evolution of joint persistence. In previous research we modelled the mechanical behavior of ice and frozen soils with a Distinct Element model and compared the evolution of the resistance with ice content with experimental data available in the literature. In this paper, we are focusing on rock joints and we are modelling both fill material (ice and frozen soil mixtures) and rock as collections of Distinct Elements, taking advantage of the previous experience in terms of calibration of the parameters. In particular, in this preliminary study, we will focus on the shear resistance of joints as a function of the composition of the fill material. The purpose of this research is to study the mechanical behavior of joints and derive the corresponding force-displacement relationship to be assigned to the interfaces between blocks in a full scale model of rock masses

Centrifuge modelling of capillary rise

This paper reports results from centrifuge tests designed to investigate capillary rise in soils subjected to different gravitational fields. The experimental programme is part of the EU-funded NECER project (Network of European Centrifuges for Environmental Geotechnic Research), whose objective is to investigate the appropriateness of geotechnical centrifuge modelling for the investigation of geoenvironmental problems, particularly with reference to partially saturated soils. The tests were performed at the geotechnical centrifuge laboratories of Cardiff. Bochum. Manchester, and LCPC in Nantes. The aim was to determine the scaling laws of capillary rise under both equilibrium and transient conditions. In all laboratories, column wetting tests in fine poorly graded sands (Congleton Sand, Bochum Normsand, HPF5 Sand, and Fontaineblau Sand) were performed. Capillary rise above the phreatic surface of the sand model was distinguished in a continuous capillary zone (completely saturated) and a discontinuous capillary zone (partially saturated). The Cardiff Geotechnical Centrifuge Laboratory used matrix potential probes to follow the capillary rise of the continuous zone and, therefore, determine the suction above the phreatic zone during centrifuge testing. Ar Bochum, two cameras were used for optical and volumetric measurements, in order to follow the rise of the visible wetting front (upper limit of discontinuous zone) in the sand within the sample column. At Manchester. the movement of the wetting front was observed by video cameras over periods up to 8 h, whereas in LCPC pore pressure transducers recorded the changes in pressure caused by capillarity. A simple centrifuge similitude law for capillary rise in these sands has been established and the kinetic phenomena have been measured as a function of the gravitational field. The results from these experiments verify that both the continuous and discontinuous capillary zones are scaled at a factor 1/N whereas the time for rise seems to be scaled at a factor 1/N-2. This research suggests that capillary phenomena can be modelled using a geotechnical centrifuge. Therefore, centrifuge testing can be a useful tool for future modelling of boundary value problems involving complex transport phenomena. (C) 2001 Elsevier Science B.V. All rights reserved