The Rock Mass Quality Index (RQI): a quantitative tool for the quality evaluation of near-surface rock masses

The knowledge of rock masses behaviour is an important information in various fields such as civil engineering, land use planning and hazard/risk zoning. Different rock mass classification methods, initially aimed at assisting underground excavations (Hoek, 2007), are widely used nowadays for preliminary design procedures (Bieniawski, 1989; Hoek, 2007), like the RMR (Bieniawski, 1976) and the Q (Barton et al., 1974) and their modifications. These methods incorporate geological, geomechanical and geometric parameters in order to obtain a quantitative estimation of the rock mass quality, but, on the other hand, their implementation is time-consuming. Despite the dominance of these two methods, further rock mass classifications systems have been proposed in the last decades and, among these, the Geological Strength Index (GSI) classification system is currently widely used as it allows to estimate the strength of rock mass through empirical semiquantitative evaluation (Hoek, 1994; Cai et al., 2004), based on both rock mass structure and condition of the joints (Hoek et al., 1995). Estimating the GSI is straightforward and fast, but it comes at the cost of a certain degree of subjectivity. Moreover, the index does not adequately account for the lithology of the rock mass matrix. Hence, for the above reasons, these classification methods are not fully suitable to collect rock mass data over wide scale areas for engineering geological mapping. The Rock mass Quality Index (RQI, Disperati et al., 2016; Mammoliti et al., 2018) is a rock mass classification system developed for cartographic purposes and it is based on the systematic fieldwork measurement and processing of sets of the Schmidt hammer rebound values (R). Each representative rock mass outcrop is analysed by collecting ca. 20 R values at the 15-25 nodes of a regular grid conceived to investigate the typical features of the rock mass. This allows to perform statistical analyses and to calculate the RQI, a quantitative indicator of the global strength and quality of the rock mass. In the last decade, a dataset of ca 1100 outcrops sites spreading over a large area (ca. 12000 km2) were acquired in Tuscany (Italy), according to different lithology, weathering, jointing conditions. The dataset consists of both RQI measurements and GSI estimations for the main different lithological groups (flysch, limestones, marls, magmatic rocks and schists) of the Northern Apennines (Italy), as well as the laboratory determinations of the Slake Durability Index (Id2; Franklin & Chandra, 1974) obtained by testing representative outcrop rock samples. The large dataset has allowed to analyse the correlation among RQI, GSI and Id2 and to perform an in-depth critical analysis of the relationships among RQI, lithology, rock mass structure, as well as the suitability of the RQI as reference index for engineering geological mapping of near-surface rock mass quality

Dismantling a volcanic edifice by deep-seated landslides: the case of the eastern Monte Amiata (Italy)

The Monte Amiata is a volcano located in central Italy composed by trachytic to olivine latitic lava flows and domes emplaced between 305 and 231 ka (Pleistocene). These volcanic products, affected by saprolite alteration processes of spatially variable intensity, unconformably overlie Pliocene marine clayey sediments, as well as the Ligurian units stacked during the Northern Apennines orogeny. The Monte Amiata area has been attracting much attention from research and industry because of its economic importance in the field of geothermal energy, ore deposits and groundwater supply, hence a quite detailed geologic framework is available for this area. Instead, less efforts were made toward the understanding of the widespread gravitational processes affecting the eastern side of the volcanic edifice, often involving the transition between the volcanic rocks and the underlying sedimentary units, where many natural springs arise. The main urban agglomerations developed in this geologic setting, so buildings and infrastructures have been suffering damages caused by landslide processes over large areas. In this context, remote sensing imagery analysis, geomorphological surveys, engineering geology sub-surface investigations and ground displacement monitoring by integrating GNSS, robotic total station and geometric levelling allow us to map the main geomorphological features and infer the geometry and displacement rates of landslides occurring in the eastern side of the Monte Amiata volcano. The results suggest the occurrence of complex gravitational processes with different kinematic characteristics, state of activity and depth of the rupture surfaces. By cross-referencing the new quantitative data collected with the geomorphological evidences and the existing literature, we propose a model for the progressive dismantling of the eastern slopes of the Monte Amiata volcano caused by the interaction among complex gravitational movements affecting, at different structural levels, both the sedimentary units and the volcanic rocks. Moreover, detailed mapping of the saprolite derived by weathering of lava flows is provided and contextualised in the post-volcanic evolution of the Monte Amiata volcano

Investigating the relationships among vegetation characters, saturated hydraulic conductivity and surface morphology at catchment scale by integrating new field data and morphometric analysis

Shallow landslides susceptibility assessment by physically based methods relies on the parametrization of both hydraulic and geotechnical properties of soils, which in turn depend on the conditions of root structures and vegetation cover. Vegetation roots contribute to the shear strength of soils, but their quantitative contribution is currently uncertain. Saturated hydraulic conductivity (Ks) is also relevant for slope stability as it influences infiltration rates and runoff. While the literature clearly shows the dependence of Ks on soil texture, there is a general understatement of the role of root structures on this parameter. Moreover, the distribution patterns of vegetation follow relations with surface morphologies which are not fully understood and therefore, are worthy of further investigations. For these reasons, this work focuses on the quantitative assessment of the influence of vegetation on shear strength for shallow landsliding and the investigation of the relationships between vegetation characters, saturated hydraulic conductivity and topographic parameters. Study areas affected by shallow landslides are chosen in the Garfagnana and Alpi Apuane regions (Northern Apennines, Italy), as well as in the Mt. Amiata volcano area (Southern Tuscany, Italy), where field measurements of below-ground vegetation (Root Area Ratio - RAR), above-ground vegetation (Leaf Area Index - LAI and vegetation load) and Ks are acquired inside, in the neighbour and far from shallow landslide sites. To this aim, a multitemporal landslide inventory is already available for the study area. Below-ground data are collected in trench profiles, while above-ground data are acquired by using a digital relascope as well as implementing vegetation cover photography methods. Measurements of Ks are carried out by means of both constant and falling head approaches. The morphometric analysis is performed by using some morphometric variables (eg. slope and hillslope curvatures) derived from a digital elevation model with cell size of 10 m. Morphometric clustering of these variables allows us to extract a set of land units where the distribution of vegetation characters and Ks are assessed. First results show that: a) root reinforcement to soil in terms of root-related cohesion plays a relevant role within the soil depths involved in shallow landslides; b) the weight of above-ground vegetation plays a “mild” negative role on slope stability; c) Ks is correlated with both RAR and soil depth, suggesting possible criteria for the straightforward parametrization of input parameters

Involvement of 5-Lipoxygenase in Alzheimer's Disease: A Role for DNA Methylation

Lipoxygenases play a major role in the neuropathology of Alzheimer's disease (AD), even though the underlying mechanisms are as yet poorly understood. Here, we studied the epigenetic regulation of 5-lipoxygenase (5-LOX) in peripheral blood mononuclear cells of subjects with late-onset AD and age-matched controls. We found a significant increase in 5-LOX gene expression in AD subjects compared to healthy controls, paralleled by increased 5-LOX protein and leukotriene B-4, the 5-LOX product. In addition, a consistent reduction in DNA methylation at 5-LOX gene promoter was documented in AD versus healthy subjects. Taken together, our findings further support a role for 5-LOX in vulnerability to neurodegeneration. [...

Epigenetic regulation of the cannabinoid receptor CB1 in an activity-based rat model of anorexia nervosa

Objective: Both environmental and genetic factors are known to contribute to the development of anorexia nervosa (AN), but the exact etiology remains poorly under- stood. Herein, we studied the transcriptional regulation of the endocannabinoid sys- tem, an interesting target for body weight maintenance and the control of food intake and energy balance. Method: We used two well-characterized animal models of AN: (a) the activity-based anorexia (ABA) model in which rats, housed with running wheels and subjected to daily food restriction, show reductions in body weight and increase in physical activ- ity; (b) the genetic anx/anx mouse displaying the core features of AN: low food intake and emaciation. Results: Among the evaluated endocannabinoid system components, we observed a selective and significant down-regulation of the gene encoding for the type 1 cannabi- noid receptor (Cnr1) in ABA rats' hypothalamus and nucleus accumbens and, in the latter area, a consistent, significant and correlated increase in DNA methylation at the gene promoter. No changes were evident in the anx/anx mice except for a down- regulation of Cnr1, in the prefrontal cortex. Discussion: Our findings support a possible role for Cnr1 in the ABA animal model of AN. In particular, its regulation in the nucleus accumbens appears to be triggered by environmental cues due to the consistent epigenetic modulation of the promoter. These data warrant further studies on Cnr1 regulation as a possible target for treat- ment of AN

The Italian guidelines on ultrasound in obstetrics and gynecology: Executive summary of recommendations for practice

Recently the Italian Ministry of Health, through National Committee for the Clinical Excellence (CNEC), commissioned to different scientific societies a number of clinical guidelines, to be developed according to a standardized methodology [1]. The Italian Society of Ultrasound in Obstetrics and Gynecology (SIEOG), together with other Italian scien- tific societies (SIGO, AOGOI, AGUI, SIMP, Italian Society of Legal Medicine, SIDiP, SIRU), has produced guidelines on the use of ultra- sound in obstetrics and gynecology [2] following the Grading of Rec- ommendations, Assessment, Development and Evaluations (GRADE) methodology [3,4] and reported according to the Appraisal of Guide- lines for Research and Evaluation Instrument (AGREE II) [5