92 research outputs found
Probabilistic identification of rockfall source areas at regional scale in El Hierro (Canary Islands, Spain)
Abstract Modelling rockfall phenomena is complex and requires various inputs, including an accurate location of the source areas. Source areas are controlled by geomorphological, geological, or other geo-environmental factors and may largely influence the results of the modelling. In the Canary Islands, rockfalls are extremely common and pose a major threat to society, costing lives, disrupting infrastructure, and destroying livelihoods. In 2011, the volcanic event on the island of El Hierro triggered numerous rockfalls that affected strategic infrastructures, with a substantial impact on the local population. During the emergency, the efforts performed to map the source areas and to model the rockfalls in the considerably steep landscape characterising the island were not trivial. To better identify the rockfall source areas, we propose a probabilistic modelling framework that applies a combination of multiple statistical models using the source area locations mapped in the field as the dependent variable and a set of thematic data as independent variables. The models use as input morphometric parameters derived from the Digital Elevation Model and lithological data as an expression of the mechanical behaviour of the rocks. The analysis of different training and validation scenarios allowed us to test the model sensitivity to the input data, select the optimal model training configuration, and evaluate the model applicability outside the training areas. The final map obtained from the model for the entire island of El Hierro provides the probability of a given location being a potential source area and can be used as the input for rockfall runout simulation modelling
Control of natural fractures in historical quarries via 3D point cloud analysis
This paper applies remote sensing techniques and 3D point cloud (3DPC) analysis to the study of historical quarries and the relationship between old quarry landscapes and the natural fracture systems of rock massifs. Ancient quarry landscapes present particular characteristics and different features from those of modern quarries. Consequently, specific considerations are needed when historical extractive places are studied. The proposed method is based on terrestrial 3D laser scanners and the structure from motion technique with remotely piloted aircraft systems. Additional specific fieldwork is required to identify and characterise quarry faces from old, blurry outcrops. A case study of the 18th century “Rambla Honda” quarries in La Romana (Alicante, SE Spain) is presented. The comparison between the fieldwork and 3DPC analysis enables the numbers and orientations of both (1) the discontinuity sets within the rock mass facilitating extraction and (2) the planes resulting from block extraction (traditional quarry faces) to be determined. The comparative analysis reveals how the stonecutters managed the extraction. The results show that structural and stratigraphic discontinuities act as planes of weakness for block extraction and determine the optimum orientation of the quarry face for minimising efforts and rock waste. The final quarry landscape is formed from the superposition of natural and artificial surfaces, but currently they appear eroded and partially covered by silting and plants. The proposed methodology contributes to distinguishing both natural and artificial discontinuities and to achieving a comprehensive knowledge of these cultural places.This research was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2017-85244-C2-1-P, the University of Alicante (Vigrob-157 and GRE18-15), and the Spanish Ministry of Science and Innovation (Grants PID2020-116896RB-C21 and PID2020-116896RB-C22 funded by MCIN/AEI/10.13039/501100011033)
A brief review of the effect of wildfires on rockfall occurrence
Wildfires and rockfalls are among the major hazards in forested mountainous regions across Europe. Understanding processes and conditions that lead to rockfalls during and after a wildfire in different geological contexts is, therefore, of great relevance. The increase of rockfalls associated with the occurrence of wildfires is connected to several factors, not only in the detached area but also in the propagation and affected area. Wildfires cause changes in the mechanical properties of rocks and discontinuities as well as the loss of protective capacity from vegetation, complemented by the effect induced by firefighting activities and by extreme temperatures that may deteriorate the installed protective measures. After the occurrence of a wildfire, there is an increase in the frequency and intensity of rockfalls in the burned area, causing a major impact of rockfalls on road networks and inhabited areas. Additionally, the rockfall risk perception is usually increased due to the removal of vegetation by wildfires, exposing both rock blocks and the rock mass. In this review, the main factors that influence the occurrence of rockfalls after a wildfire are briefly reviewed
Peroxisome proliferator-activated receptor alpha plays a crucial role in behavioral repetition and cognitive flexibility in mice
Acknowledgments We thank Luca Giordano, Giovanni Esposito and Angelo Russo for technical assistance and Dr. Livio Luongo (Second University of Naples–Italy) for critical discussions. This work was supported by a Grant PRIN from Ministry of Education, Universities and Research (MIUR), Italy, to A.C. and the Wellcome Trust (WT098012) to L.K.H. and BBSRC (BB/K001418/1) to L.K.H. and G.D’A. G.D’A. received partial supports from a “FORGIARE” post-doctoral fellowship cofounded by the Polo delle Scienze e Tecnologie per la Vita, University of Naples Federico II and Compagnia di San Paolo Foundation, Turin, Italy (2010–2012).Peer reviewedPublisher PD
Gaia's Cepheids and RR Lyrae Stars and Luminosity Calibrations Based on Tycho-Gaia Astrometric Solution
Gaia Data Release 1 contains parallaxes for more than 700 Galactic Cepheids
and RR Lyrae stars, computed as part of the Tycho-Gaia Astrometric Solution
(TGAS). We have used TGAS parallaxes, along with literature () photometry and spectroscopy, to calibrate the zero point
of the Period-Luminosity and Period-Wesenheit relations of classical and type
II Cepheids, and the near-infrared Period-Luminosity,
Period-Luminosity-Metallicity and optical Luminosity-Metallicity relations of
RR Lyrae stars. In this contribution we briefly summarise results obtained by
fitting these basic relations adopting different techniques that operate either
in parallax or distance (absolute magnitude) space.Comment: 5 pages, 4 figures, proceedings for the 22nd Los Alamos Stellar
Pulsation Conference Series Meeting "Wide field variability surveys: a
21st-century perspective", held in San Pedro de Atacama, Chile, Nov. 28 -
Dec. 2, 201
When nutraceuticals reinforce drugs side effects: A case report
INTRODUCTION:
Nutraceutical is a term applied for a plethora of products ranging from isolated nutrients, herbal products to dietary supplements and recently, the interest for a nutraceutical approach to lipid and metabolic disorders is growing. Patients with metabolic conditions seem to appreciate a therapeutic management that does not involve drug treatment, particularly for the side effects due to statins, a class of drug used for lipid disorders. Statins directly induce skeletal muscle injury and in the elderly patients, under polytherapy treatments, this risk relies to an increase in adverse drug reactions due to drug interactions.
CASE DESCRIPTION:
Herein we report a 70-year-old woman under polytherapy who developed rhabdomyolysis after starting the administration of a dietary supplement containing monacolin K. Using the Drug Interaction Probability Scale, we postulated that rhabdomyolysis was possibly related to a drug interaction between sertraline, rosuvastatin and monacolin K. These treatments were discontinued leading to a remission of both clinical symptoms and biochemical parameters.
CONCLUSION:
This case report highlights how pharmacological treatment must be periodically reassessed, since elderly people could take drugs by themselves when they donot need
Pharmacokinetic-pharmacodynamic influence of N-palmitoylethanolamine, arachidonyl-2′-chloroethylamide and WIN 55,212-2 on the anticonvulsant activity of antiepileptic drugs against audiogenic seizures in DBA/2 mice
We evaluated the effects of ACEA (selective cannabinoid (CB)1 receptor agonist), WIN 55,212-2 mesylate (WIN; non-selective CB1 and CB2 receptor agonist) and N-palmitoylethanolamine (PEA; an endogenous fatty acid of ethanolamide) in DBA/2 mice, a genetic model of reflex audiogenic epilepsy. PEA, ACEA or WIN intraperitoneal (i.p.) administration decreased the severity of tonic-clonic seizures. We also studied the effects of PEA, WIN or ACEA after co-administration with NIDA-41020 (CB1 receptor antagonist) or GW6471 (PPAR-α antagonist) and compared the effects of WIN, ACEA and PEA in order to clarify their mechanisms of action. PEA has anticonvulsant features in DBA/2 mice mainly through PPAR-α and likely indirectly on CB1 receptors, whereas ACEA and WIN act through CB1 receptors. The co-administration of ineffective doses of ACEA, PEA and WIN with some antiepileptic drugs (AEDs) was examined in order to identify potential pharmacological interactions in DBA/2 mice. We found that PEA, ACEA and WIN co-administration potentiated the efficacy of carbamazepine, diazepam, felbamate, gabapentin, phenobarbital, topiramate and valproate and PEA only also that of oxcarbazepine and lamotrigine whereas, their co-administration with levetiracetam and phenytoin did not have effects. PEA, ACEA or WIN administration did not significantly influence the total plasma and brain levels of AEDs; therefore, it can be concluded that the observed potentiation was only of pharmacodynamic nature. In conclusion, PEA, ACEA and WIN show anticonvulsant effects in DBA/2 mice and potentiate the effects several AEDs suggesting a possible therapeutic relevance of these drugs and their mechanisms of action
Seasonal rockfall risk analysis in a touristic island: Application to the Tramuntana Range (Mallorca, Spain)
Rockfalls are an ever-present possibility in the mountainous context of the Tramuntana Region (Mallorca, Spain). Recent events have shown the high potential for direct and indirect impact on the safety of people and economic activities, lasting for weeks or even months. In the present study, we start from a probabilistic assessment of the rockfall hazard (spatial propensity and temporal recurrence), based on a detailed historical record of occurrences and rockfall modelling, which is subsequently superimposed on three exposure scenarios and on a social vulnerability assessment. Exposure considers the floating population at three seasons of the year, given the area's high tourist aptitude. Vulnerability considers on the one hand the intrinsic characteristics of individuals and, on the other, the characteristics of the surrounding territory that act to facilitate emergency operations, mitigate the immediate impact and enhance rapid recovery. Due to the characteristics of the island and the spatial distribution of tourism, the results show that the highest density of rockfall trajectories potentially affect areas of high exposure, whose access by emergency services is complex. Not being, in general, the areas of highest individual criticality, those areas have in most situations low support capability installed or nearby.
The results constitute a useful tool for emergency and risk management planning in multiple sectors linked to risk governance. Despite the high geographic detail of the analysis, these studies do not replace exposure and vulnerability analysis at the building level, for which the contribution of georeferenced Census data is fundamental
Pain Modulation in WAG/Rij Epileptic Rats (A Genetic Model of Absence Epilepsy): Effects of Biological and Pharmacological Histone Deacetylase Inhibitors
Epigenetic mechanisms are involved in epilepsy and chronic pain development. About that, we studied the effects of the natural histone deacetylase (HDAC) inhibitor sodium butyrate (BUT) in comparison with valproic acid (VPA) in a validated genetic model of generalized absence epilepsy and epileptogenesis. WAG/Rij rats were treated with BUT (30 mg/kg), VPA (300 mg/kg), and their combination (BUT + VPA) daily per os for 6 months. Rats were subjected at Randall-Selitto, von Frey, hot plate, and tail flick tests after 1, 3, and 6 months of treatment to evaluate hypersensitivity to noxious and non-noxiuous stimuli. Moreover, PPAR-γ (G3335 1 mg/kg), GABA-B (CGP35348 80 mg/kg), and opioid (naloxone 1 mg/kg) receptor antagonists were administrated to investigate the possible mechanisms involved in analgesic activity. The expression of NFkB, glutathione reductase, and protein oxidation (carbonylation) was also evaluated by Western blot analysis. WAG/Rij rats showed an altered pain threshold throughout the study (p < 0.001). BUT and BUT + VPA treatment reduced hypersensitivity (p < 0.01). VPA was significantly effective only after 1 month (p < 0.01). All the three receptors are involved in BUT + VPA effects (p < 0.001). BUT and BUT + VPA decreased the expression of NFkB and enhanced glutathione reductase (p < 0.01); protein oxidation (carbonylation) was reduced (p < 0.01). No effect was reported with VPA. In conclusion BUT, alone or in coadministration with VPA, is a valuable candidate for managing the epilepsy-related persistent pain
ADATools: a set of tools for the analysis of terrain movement maps obtained with SAR Interferometry
The SAR Interferometry techniques, Persistent Scatterer Interferometry (PSI) among them, are nowadays known as important tools for monitoring Earth surface movements. Several regional and national Ground Motion Services based on PSI already exist. Moreover, since 2022 the European Ground Motion Service will be operational and will annually provide an updated displacement map over the whole Europe. This will suppose a big amount of ground displacement measurements along the European territory. For each measurement EGMS will provide the annual velocity and the time series of deformation covering the period 2014 to one year prior to each delivery. In this context, it will be more and more necessary having tools to ease the management, analysis, and interpretation, of those wide areas and huge amount of data. We present here a first step in this direction: the ADATools are a set of tools to automatically have secondary, and more operational, products derived from a PSI map. Starting from a fast extraction of the most significant Active Deformation Areas (ADA), with the ADAFinder tool, then we can have a preliminary classification of the most probable phenomena (landslides, subsidence, settlements, or sinkholes) that is behind the detected movement, with the ADAClassifier tool. Moreover, LOS2hv tool allows to derive the horizontal (east-west) and vertical components of the movement in case we have maps of ascending and descending geometries. Finally, it is presented a product that analyzes the local displacement gradients to generate potential damage maps in urban areas. The tools will be presented thorough some results obtained on an area of the Granada County with the use of Sentinel-1 data. All the results have been achieved within the framework of the Riskcoast Project (financed by the Interreg Sudoe Program through the European Regional Development Fund, ERDF).This work was mainly supported by the European Regional Development Fund (ERDF) through the project “RISKCOAST” (SOE3/P4/E0868) of the Interreg SUDOE Programme
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