171 research outputs found
Sobre cómo representar y parametrizar la Peligrosidad, la Vulnerabilidad y el Daño para transmitir los resultados de un estudio de riesgo sísmico a escala regional/ On the representation and parameterization of Seismic Hazard, Vulnerability and Damag
This work presents different issues related to seismic risk assessment and styles of comunicating partial and final results on maps for remarkably distinct people, such as scientists, preparedness and response officers and general public. The convenience of making different classifications and representations of building vulnerability types, seismic hazard parameters and damage estimates in function of the final user of the results is highlighted. Results of recent risk assessment study of Murcia (south eastern Spain) carried out by the authors are used for illustration
Evaluación del riesgo sísmico con técnicas de información geográfica. Aplicación en Navarra
El SIG-RISNA es un sistema de información geográfica desarrollado en el marco de un proyecto de evaluación del riesgo sísmico en la Comunidad Foral de Navarra, Proyecto RISNA. El objetivo general del mismo es hacer una evaluación, de carácter científicotécnica, que sirva de base para desarrollar el Plan Especial de Emergencia de la región y para la identificación de municipios de especial riesgo de cara a su posterior estudio local. Para esta evaluación, se combinan diferentes factores influyentes en el riesgo sísmico, tales como la peligrosidad sísmica, las características geotécnicas del suelo y la vulnerabilidad de estructuras de la región. Todas estas variables se integran en la estimación del riesgo por medio un SIG, que constituye una herramienta de trabajo de gran utilidad, ya que facilita la interoperabilidad de los datos haciendo más manejable el gran volumen de información requerida y los numerosos procesos que intervienen en el cálculo. En este artículo de describirán las características y el esqueleto del SIG-RISNA, incluyendo los datos de partida necesarios y los procesos y análisis realizados para la consecución del mismo. El resultado de este estudio comprende un gran conjunto de variables que dan una visión global del riesgo sísmico en la región, como son la distribución de daños para diferentes tipologías, el daño medio y el número de edificaciones que quedarían inhabitables ante el movimiento esperado, entre otros. Estos resultados están destinados a la interpretación y toma de decisiones, de personal no especializado (técnicos y gestores de Protección Civil), hacia la gestión de la emergencia. Por este motivo, una transmisión comprensible de los resultados de forma que puedan ser correctamente interpretados se considera un apartado de especial importancia dentro del estudio. En este contexto se desarrolló el visualizador Web VISORRISNA, una aplicación Web que contiene todos los resultados del estudio expuestos por medio de un conjunto de capas de información temática y con un acceso múltiple a la correspondiente base de datos. Esta herramienta también fue diseñada para que los usuarios finales pudieran establecer diferentes niveles de actuación considerando el daño esperado en cada municipio, mediante un módulo específico creado con dicha finalidad
Sobre la medida del tamaño del terremoto y la peligrosidad sísmica en España/ On earthquake size measures and seismic hazard in Spain
The influence of earthquake size parameters contained on seismic catalogues on seismic hazard assessment studies is discussed. The topic is illustrated in the Spanish context, characterized by moderate seismic activity and consequently, limited availability of seismic data. The different objectives pursued by seismic catalogue providers and users (in this case, earthquake hazard analysts) may cause misunderstandings and possibly misuses of catalogued size parameters. As an example, it is shown that magnitude data sets should be treated separately depending on the geographic area considered. Accordingly, region-dependent correlations between magnitude scales, required for implementing seismic hazard analyses, are presented. Results of this work underline the need of composing earthquake catalogues with homogeneous earthquake size parameters not only for historical events, but also for recent and future ones
Natural Approaches for Neurological Disorders—The Neuroprotective Potential of Codium tomentosum
Parkinson’s disease (PD) is the second most common neurodegenerative disorder, and is characterized by a progressive degeneration of the dopaminergic neurons in the substantianigra. Although not completely understood, several abnormal cellular events are known to be related with PD progression, such as oxidative stress, mitochondrial dysfunction and apoptosis. Accordingly, the aim of this study was to evaluate the neuroprotective effects of Codium tomentosum enriched fractions in a neurotoxicity model mediated by 6-hydroxydopamine (6-OHDA) on SH-SY5Y human cells, and the disclosure of their mechanisms of action. Additionally, a preliminary chemical screening of the most promising bioactive fractions of C. tomentosum was carried out by GC-MS analysis. Among the tested fractions, four samples exhibited the capacity to revert the neurotoxicity induced by 6-OHDA to values higher or similar to the vitamin E (90.11 ± 3.74% of viable cells). The neuroprotective effects were mediated by the mitigation of reactive oxygen species (ROS) generation, mitochondrial dysfunctions and DNA damage, together with the reduction of Caspase-3 activity. Compounds belonging to different chemical classes, such as terpenes, alcohols, carboxylic acids, aldehydes, esters, ketones, saturated and unsaturated hydrocarbons were tentatively identified by GC-MS. The results show that C. tomentosum is a relevant source of neuroprotective agents, with particular interest for preventive therapeuticsThis work was supported by the Portuguese Foundation for Science and Technology (FCT) through the strategic project UID/MAR/04292/2020 to MARE—Marine and Environmental Sciences Centre and UID/Multi/04046/2020 and UIDB/04046/2020 granted to BioISI—BioSystems and Integrative Sciences Institute, through POINT4PAC project (Oncologia de Precisão: Terapias e Tecnologias Inovadoras, SAICTPAC/0019/2015-LISBOA-01-0145-FEDER-016405), through CROSS-ATLANTIC project (PTDC/BIA-OUT/29250/2017), co-financed by COMPETE (POCI-01-0145-FEDER-029250) and through Molecules for Health project (PTDC/BIA-BQM/28355/2017). This work was also funded by the Integrated Programme of SR&TD Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate (Centro-01-0145-FEDER-000018), co-funded by Centro 2020 Programme, Portugal 2020, European Union, through the European Regional Development FundS
Towards a new seismic hazard assessment in Spain
Seismic hazard is an evolving science that is fed by geological and seismological studies. As new data and models arise, the revision of hazard maps is compelling. Additionally, understanding the nature and the sources of the uncertainties involved in seismic hazard analyses is essential in order to reduce them. In this context, Spain is not an exception and a move towards a reassessment of the national hazard maps is pertinent. Several hazard-controlling factors needing to be updated and eventually revaluated are identified in this work in progress. The first one concerns the seismic catalogue. It must be homogenised, incorporating data from neighbouring countries and correlating magnitude scales for different regions and recording periods. A second factor refers to seismicity characterization by zoning and zoneless models: Neotectonic, seismological and other geological data that justify the development of a new zoning model for Spain and adjacent areas are disclosed. Revaluation of seismic areas that are traditionally considered as stable but show evidence of seismic activity at present and during Quaternary times needs to be considered. The interest of developing a neotectonic characterization of active faults is advanced. For zoneless models, the different elements that define the continuous spatial variation of the activity rate density have to be examined. For a zoneless model based on kernel functions, these elements would be the specific type of kernel function, the bandwidth and the reference years. A third factor requiring a modern analysis refers to the implementation of different strong motion prediction models. These include models based on local data and developed with data from other regions. Special attention is paid to the application of the next generation attenuation models originally developed for western North America to Spain. Criteria for selecting different models must be clearly and thoughtfully enumerated. The final goal of this work is to assess the variability of seismic hazard results to the new data and models that are becoming available. Such information will be of indubitable interest for forthcoming versions of the seismic code, national annexes of Eurocode 8 and research projects fomented by the Spanish Nuclear Security Counci
Seismic hazard assessment of Navarre (Northern Spain)
The RISNAV project, financed by the Civil Defence Department of Navarre (Northern Spain), aims at assessing seismic risk of the entire region. The final goal of the project is the definition of emergency plans for future earthquakes. With this purpose, four main topics are covered: seismic hazard characterization, geotechnical classification, vulnerability assessment and damage estimation. In this work, the seismic hazard and vulnerability assessment studies are presented
Uncertainty Analysis in New Seismic Hazard Study of Spain Aimed at the Revision of the Spanish Building Code.
In this paper we present a global overview of the recent study carried out in Spain for the new hazard map, which final goal is the revision of the Building Code in our country (NCSE-02). The study was carried our for a working group joining experts from The Instituto Geografico Nacional (IGN) and the Technical University of Madrid (UPM) , being the different phases of the work supervised by an expert Committee integrated by national experts from public institutions involved in subject of seismic hazard. The PSHA method (Probabilistic Seismic Hazard Assessment) has been followed, quantifying the epistemic uncertainties through a logic tree and the aleatory ones linked to variability of parameters by means of probability density functions and Monte Carlo simulations. In a first phase, the inputs have been prepared, which essentially are: 1) a project catalogue update and homogenization at Mw 2) proposal of zoning models and source characterization 3) calibration of Ground Motion Prediction Equations (GMPE’s) with actual data and development of a local model with data collected in Spain for Mw < 5.5. In a second phase, a sensitivity analysis of the different input options on hazard results has been carried out in order to have criteria for defining the branches of the logic tree and their weights. Finally, the hazard estimation was done with the logic tree shown in figure 1, including nodes for quantifying uncertainties corresponding to: 1) method for estimation of hazard (zoning and zoneless); 2) zoning models, 3) GMPE combinations used and 4) regression method for estimation of source parameters. In addition, the aleatory uncertainties corresponding to the magnitude of the events, recurrence parameters and maximum magnitude for each zone have been also considered including probability density functions and Monte Carlo simulations The main conclusions of the study are presented here, together with the obtained results in terms of PGA and other spectral accelerations SA (T) for return periods of 475, 975 and 2475 years. The map of the coefficient of variation (COV) are also represented to give an idea of the zones where the dispersion among results are the highest and the zones where the results are robust
Oxidative stress status in an institutionalised elderly group after the intake of a phenolic-rich dessert
The present study was supported by a grant from Hero España S.A. M. C. R.-T. and J. L. Q. are recipients of a ‘Ramón y Cajal’ contract from the Ministry of Science and Technology and the University of Granada, Spain. We also thank the Fundacio´n Se´neca of the C.A.R.M. (Murcia, Spain) for the fellowship of J. G.-A.The elderly population undergoes a series of physiological and sociological changes common to old age with a high probability of suffering degenerative illness and malnutrition. A dessert rich in phenolic compounds has been designed by using concentrated juices of grape, cherry, blackberry, blackcurrant and raspberry with the aim of it being used as a complementary food in adulthood. In the present study, we investigated the effect of the intake of this dessert (a jar of 200 g daily for a period of 2 weeks), with an antioxidant activity equivalent to ten servings of fruits and vegetables, on several markers of oxidative and antioxidant status in DNA and plasma in a group of elderly individuals. Non-smoking institutionalised elderly subjects were recruited from a pool of volunteers in an old-age home in Murcia (Spain). Twenty-two subjects (six men and sixteen women) participated in the study. The study was designed as a randomised intervention trial with a period of 2 weeks. At days 1 and 15, blood samples were collected to analyse total antioxidant capacity, biochemical parameters, antioxidant vitamins, LDL peroxidation, and DNA damage in peripheral blood lymphocytes. The conclusion of the present study is that a 2-week intervention with our dessert enriched with natural polyphenol compounds in elderly individuals does not give enough time to find changes in the antioxidant and oxidative status. Also, the view that the marked antioxidant ability of polyphenols in vitro does not translate to analogous effects in vivo was confirmed. Moreover, a highly oxidative stress status during ageing was confirmed, together with the need to perform follow-up nutritional studies to improve this situation
Aceleraciones registradas y calculadas del sismo del 12 de agosto de 2014 en Quito.
El 12 de agosto de 2014, se registró un sismo de magnitud 5.1, a una profundidad focal de 4 km., en el segmento de falla Bellavista Catequilla, el mismo que fue registrado en 8 estaciones localizadas en la ciudad de Quito. Estas se encuentran ubicadas a distancias epicentrales entre 12 y 19 km. En este artículo se comparan las aceleraciones máximas obtenidas en campo libre, con las que se obtienen al emplear las ecuaciones de movimientos fuertes de Campbell y Borzognia (2013) y el de Zhao et al. (2006). Para ello previamente se determina un plano de ruptura del sismo, utilizando las ecuaciones propuestas por Leonard (2010) y la geometría de las fallas ciegas propuestas por Alvarado (2014).
ABSTRACT: On August 12 th 2014, a magnitude 5.1 earthquake occurred at a depth of 4 km, in the Bellavista Catequilla fault segment. This event was recorded by 8 strong-motion stations located between 12 and 19 km from the epicenter, in the city of Quito.
In this article, the maximum ground accelerations recorded in free field are compared with the accelerations estimated using the models by Campbell y Borzognia (2013) and Zh ao et al. (2006). To this end, the earthquake rupture plane is determined using the equations proposed by Leonard (2010) and the geometry of the blind fault system of Quito proposed by Alvarado (2014)
Seismic hazard in Andalucia region (Southern Spain)
The global objective of the SISMOSAN Project has been to provide a general seismic risk assessment of Andalusian region (Southern Spain) associated with the ground motions expected for a return period of 475 years. The project was financed by Civil Defence of Andalusia and its results will be applied to the definition of regional emergency plans. We present here the study and main results of the first phase of the project, aimed at evaluating seismic hazard. In contrast to most of the previous studies in the region, which were performed for peak ground accelerations (PGA) making use of Intensity-to-PGA relationships, hazard was here calculated in terms of magnitude and using published spectral ground-motion models. Moreover, we have considered distinct models for the Atlantic earthquakes, since the attenuation of those motions seem to be slower, as evidenced by the extensive macroseismic areas of the 1755, 1969 and 2007 earthquakes. A comprehensive revision of the seismic catalogue, as well as of the seismogenic models proposed for the region (including those for North Africa, which is part of the influence area) has been done. In a first step, seismic hazard was evaluated at generic rock sites covering the entire region, using a seismic catalogue homogenized to moment magnitude and considering attenuation models in terms of PGA and spectral ordinates (SA). A Probabilistic Seismic Hazard Assessment (PSHA) methodology was followed using a logic tree, in order to constrain the epistemic uncertainty, including two nodes for different options of zonification and attenuation models. In a second step, a geotechnical characterization of the whole region has been carried out, mainly inferred from geological maps and refined with on-site data, which are combined with rock acceleration estimates, in order to compose hazard maps that incorporate local soil effects
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