Evaluation of analytical methodologies to derive vulnerability functions

The recognition of fragility functions as a fundamental tool in seismic risk assessment has led to the development of more and more complex and elaborate procedures for their computation. Although vulnerability functions have been traditionally produced using observed damage and loss data, more recent studies propose the employment of analytical methodologies as a way to overcome the frequent lack of post-earthquake data. The variation of the structural modelling approaches on the estimation of building capacity has been the target of many studies in the past, however, its influence in the resulting vulnerability model, impact in loss estimations or propagation of the uncertainty to the seismic risk calculations has so far been the object of restricted scrutiny. Hence, in this paper, an extensive study of static and dynamic procedures for estimating the nonlinear response of buildings has been carried out in order to evaluate the impact of the chosen methodology on the resulting vulnerability and risk outputs. Moreover, the computational effort and numerical stability provided by each approach were evaluated and conclusions were obtained regarding which one offers the optimal balance between accuracy and complexity

Development of an open-source platform for calculating losses from earthquakes

Risk analysis has a critical role in the reduction of casualties and damages due to earthquakes. Recognition of this relation has led to a rapid rise in demand for accurate, reliable and flexible risk assessment numerical tools and software. As a response to this need, the Global Earthquake Model (GEM) started the development of an open source platform called OpenQuake, for calculating seismic hazard and risk at different scales. Along with this framework, also several other tools to support users creating their own models and visualizing their results are currently being developed, and will be made available as a Modelers Tool Kit (MTK). In this paper, a description of the architecture of OpenQuake is provided, highlighting the current data model, workflow of the calculators and the main challenges raised when running this type of calculations in a global scale. In addition, a case study is presented using the Marmara Region (Turkey) for the calculations, in which the losses for a single event are estimated, as well as probabilistic risk for a 50 years time span

Developing a global risk engine

Risk analysis is a critical link in the reduction of casualties and damages due to earthquakes. Recognition of this relation has led to a rapid rise in demand for accurate, reliable and flexible risk assessment software. However, there is a significant disparity between the high quality scientific data developed by researchers and the availability of versatile, open and user-friendly risk analysis tools to meet the demands of end-users. In the past few years several open-source software have been developed that play an important role in the seismic research, such as OpenSHA and OpenSEES. There is however still a gap when it comes to open-source risk assessment tools and software. In order to fill this gap, the Global Earthquake Model (GEM) has been created. GEM is an internationally sanctioned program initiated by the OECD that aims to build independent, open standards to calculate and communicate earthquake risk around the world. This initiative started with a one-year pilot project named GEM1, during which an evaluation of a number of existing risk software was carried out. After a critical review of the results it was concluded that none of the software were adequate for GEM requirements and therefore, a new object-oriented tool was to be developed. This paper presents a summary of some of the most well known applications used in risk analysis, highlighting the main aspects that were considered for the development of this risk platform. The research that was carried out in order to gather all of the necessary information to build this tool was distributed in four different areas: information technology approach, seismic hazard resources, vulnerability assessment methodologies and sources of exposure data. The main aspects and findings for each of these areas will be presented as well as how these features were incorporated in the up-to-date risk engine. Currently, the risk engine is capable of predicting human or economical losses worldwide considering both deterministic and probabilistic-based events, using vulnerability curves. A first version of GEM will become available at the end of 2013. Until then the risk engine will continue to be developed by a growing community of developers, using a dedicated open-source platform

Critical exponents for the long-range Ising chain using a transfer matrix approach

The critical behavior of the Ising chain with long-range ferromagnetic interactions decaying with distance $r^\alpha$, $1<\alpha<2$, is investigated using a numerically efficient transfer matrix (TM) method. Finite size approximations to the infinite chain are considered, in which both the number of spins and the number of interaction constants can be independently increased. Systems with interactions between spins up to 18 sites apart and up to 2500 spins in the chain are considered. We obtain data for the critical exponents $\nu$ associated with the correlation length based on the Finite Range Scaling (FRS) hypothesis. FRS expressions require the evaluation of derivatives of the thermodynamical properties, which are obtained with the help of analytical recurrence expressions obtained within the TM framework. The Van den Broeck extrapolation procedure is applied in order to estimate the convergence of the exponents. The TM procedure reduces the dimension of the matrices and circumvents several numerical matrix operations.Comment: 10 pages, 2 figures, Conference NEXT Sigma Ph

Critical behavior of an Ising model with aperiodic interactions

We write exact renormalization-group recursion relations for a ferromagnetic Ising model on the diamond hierarchical lattice with an aperiodic distribution of exchange interactions according to a class of generalized two-letter Fibonacci sequences. For small geometric fluctuations, the critical behavior is unchanged with respect to the uniform case. For large fluctuations, the uniform fixed point in the parameter space becomes fully unstable. We analyze some limiting cases, and propose a heuristic criterion to check the relevance of the fluctuations.Comment: latex file, 5 figures, accepted by Braz. Jour. Phy

Utilization of Cholera Toxin B as an Adjuvant for the Subunit PspA Vaccine, Provides Effective Protection against Streptococcus pneumoniae Challenge

Streptococcus pneumoniae is a prevalent human pathogen associated with pneumonia. It is estimated that approximately 1 million people around the world die each year, specifically with young children and the elderly comprising a significant portion. Currently, antibiotics can treat the infection but individuals such as the young or elderly are more susceptible to bodily damage from symptoms, such as pneumonia, meningitis, and sepsis, thus require more preventive measures. As a result, vaccinations are a key solution to providing effective protection against infectious pathogens. Presently, two vaccinations exist in the market: PPSV23 and PCV13, which only protect against select 23 or 13 serotypes respectively of Streptococcus pneumoniae out of the possible 90. Researchers are searching for alternative antigenic markers conserved throughout the multitude of serotypes to formulate cross-protective vaccinations. One such proponent is known as Pneumococcal Surface Protein A (PspA) which is a surface protein conserved throughout most serotypes and a potential candidate as a subunit vaccine against Streptococcus pneumoniae. To increase the immunogenicity of PspA for long term and effective protection, this study utilizes Cholera Toxin B (CTB) as an adjuvant to effectively increase vaccine efficacy. We assessed the efficacy of the subunit vaccine, PspA, administered intranasally (i.n.) in conjunction with CTB as an adjuvant. Our results indicated increased survival in mice immunized with both PspA and CTB accompanied with reduced lung bacterial burden, increased levels of S. pneumoniae-specific IgG subclass antibodies, increased cytokine production, and a reduced acute inflammatory response

Portraits of change by farmers in Southern Guinea-Bissau

This photo essay, whose images and captions were created by farmers living in Cantanhez National Park, Guinea-Bissau, illustrates and analyzes the diverse ways in which these West African photographers and collaborative researchers chose to represent change. Some of the visual and narrative devices employed by the photographers include staging the past; representing before/after situations; and thoughtful composition in the visual depiction of changed and changing physical environments. Beyond our initial research focus on perceptions of climatic changes, these farmers turned photographers shared compelling portrayals of change in its social, economic, ecological and cultural complexity, in some cases offering counter-narratives to the dominant environmentalist narrative about this protected area.info:eu-repo/semantics/publishedVersio