Rui Filipe Pedreira Marques

A model for pushover analysis of confined masonry structures: implementation and validation

Confined masonry (CM) is a typical building technique in Latin American countries. This technique, due to its simplicity of construction and similarity with traditional practices of reinforced concrete building, presents a potential of use in European regions with moderate-to-high seismicity. However, most of the procedures for seismic design in codes for Latin America are force-based, which appears to be inadequate due to the high dissipative response observed for CM. This paper presents a simplified numerical-analytical approach to model CM structures using pushover analysis, aiming to apply performance-based design procedures. First, a data mining process is performed on a database of experimental results collected from lateral tests on CM walls to adjust prediction models for the wall shear strength and to determine the input relevance through a sensitivity analysis. Then, an analytical model of CM structures for pushover analysis is proposed with basis on a wide-column approach that employs an adaptive shear load-displacement constitutive relation. The proposed method is compared with a discrete element model that represents explicitly the confinements-masonry interaction, against the experimental results obtained in a quasi-static test of a full-scale tridimensional CM structure. The accuracy of the predictions from both methods is very satisfactory, allowing to capture the base shear-displacement envelope and also the damage patterns of the structure, thus, demonstrating the ability of the methods to be used in performance-based seismic assessment and design of CM buildings.

Artificial intelligence applications in transportation geotechnics

This paper presents a brief overview of artificial intelligence applications in transportation geotechnics, highlighting new approaches and current research directions, including issues related to data mining interpretability and prediction capacities. Several practical applications to earthworks, including the compaction management and quality control aspects of embankments, as well as pavement evaluation, design and management, and the mechanical behaviour of jet grouting material, are presented to illustrate the advantages of using data mining, including artificial neural networks, support vector machines, and evolutionary computation techniques in this domain. This study also propose a novel simplified compaction table for reusing geomaterials and compaction management in embankments and applied one- and two-dimensional advanced sensitivity analyses to better interpret the proposed data-driven models for the prediction of the deformability modulus of jet grouting field samples. These applications show the capabilities of data mining models to address complex problems in transportation geotechnics involving highly nonlinear relationships of data and optimisation needs.

Study of the Seismic Behavior of the “Old Municipal Chambers” Building in Christchurch, New Zealand

This article presents a study of the seismic behavior of the “Old Municipal Chambers” building in Christchurch, which was damaged by earthquakes in 2010 and 2011. In view of its seismic vulnerability and retrofitting, finite element and equivalent frame models were used for pushover analysis. Predictions allow identifying the weak parts of the building and its expected failure modes, which are in agreement with the observed damage. Computations seem conservative, however, because the building capacity curves provide insufficient strength to survive the registered earthquakes. By considering the floors as bidirectional diaphragms in the simplified model, a better behavior is observed.

Direct treatment costs of HIV/AIDS in Portugal

OBJETIVO Analisar dos custos diretos medicos com VIH/SIDA, de acordo com a perspetiva do Servico Nacional de Saude, em Portugal. METODOS Efetuou-se analise retrospectiva de registros medicos em amostra de 150 pacientes de cinco centros especializados em 2008. Foram obtidos dados de utilizacao de recursos medicos durante 12 meses e das caracteristicas dos pacientes nesse periodo. Aplicou-se o custo unitario a cada componente de custo, usando fontes oficiais e dados contabilisticos dos hospitais. RESULTADOS O custo medio anual de tratamento foi de 14.277 euros por paciente. A parcela de custo mais importante foi o custo com o tratamento antirretroviral (9.598 euros), seguido dos custos de internacao (1.323 euros). Os custos de tratamento com severidade aumentaram de 11.901 euros (> 500 CD4 celulas/µl) para 23.351 euros (CD4 ≤ 50 celulas/µl). A progressao dos custos deve-se principalmente ao aumento dos custos de internacao, dado que os custos com tratamento antirretroviral se mantem constantes ao longo dos estadios. CONCLUSOES O custo elevado do tratamento antirretroviral e compensado com o custo relativamente baixo da internacao, apesar deste aumentar com a severidade. A baixa progressao dos custos totais revela que estrategias de saude publica alternativas que nao alterem a transmissao da doenca terao apenas impacto limitado nas despesas, dado que os custos sao largamente influenciados pelo do tratamento antirretroviral.

Virologic suppression in treatment-experienced patients after virologic rebound or failure of therapy.

PURPOSE OF REVIEW To discuss factors related to virologic failure and review data from recent clinical trials evaluating re-suppression of viremia in extensively-treated HIV-infected patients with resistance. RECENT FINDINGS Factors associated with virologic failure can be related to the virus (e.g. resistance), the patient (e.g. adherence) or HIV therapy (e.g. availability) and must be analyzed to minimize the likelihood of a new failure. Recent clinical trials have shown that it is now possible to achieve virologic suppression in a large proportion of treatment-experienced patients with extensive drug resistance, with several newer agents demonstrating favorable potency, tolerability and long-term efficacy. SUMMARY The benefits of highly active antiretroviral treatment are well recognized, and adding at least two (preferably three) new active drugs to an optimized background regimen can provide effective suppression of viremia even in multidrug-experienced patients. Changing drugs or regimen simplification should be considered when treatment is inadequate, poorly tolerated or associated with poor adherence, and is made easier by the newer agents and formulations now available. Newer antiretrovirals may contribute to a better quality of life and life expectancy in patients with few or no therapy options, although adherence is paramount in ensuring their continued effectiveness.

Análisis mecánico de albañilería arqueológica de adobe bajo cargas de compresión uniaxial: El caso de Huaca de la Luna

Patronato Huacas del Valle Moche; Proyecto Piloto de Evaluacion del Estado Estructural Actual y Comportamiento Sismico del Complejo Arqueologico Moche Huaca de la Luna, Direccion de Gestion de la Investigacion (DGI PUCP), ref. 89-2014

Costos originados por tratamiento del VIH/SIDA en Portugal

OBJETIVO Analisar dos custos diretos medicos com VIH/SIDA, de acordo com a perspetiva do Servico Nacional de Saude, em Portugal. METODOS Efetuou-se analise retrospectiva de registros medicos em amostra de 150 pacientes de cinco centros especializados em 2008. Foram obtidos dados de utilizacao de recursos medicos durante 12 meses e das caracteristicas dos pacientes nesse periodo. Aplicou-se o custo unitario a cada componente de custo, usando fontes oficiais e dados contabilisticos dos hospitais. RESULTADOS O custo medio anual de tratamento foi de 14.277 euros por paciente. A parcela de custo mais importante foi o custo com o tratamento antirretroviral (9.598 euros), seguido dos custos de internacao (1.323 euros). Os custos de tratamento com severidade aumentaram de 11.901 euros (> 500 CD4 celulas/µl) para 23.351 euros (CD4 ≤ 50 celulas/µl). A progressao dos custos deve-se principalmente ao aumento dos custos de internacao, dado que os custos com tratamento antirretroviral se mantem constantes ao longo dos estadios. CONCLUSOES O custo elevado do tratamento antirretroviral e compensado com o custo relativamente baixo da internacao, apesar deste aumentar com a severidade. A baixa progressao dos custos totais revela que estrategias de saude publica alternativas que nao alterem a transmissao da doenca terao apenas impacto limitado nas despesas, dado que os custos sao largamente influenciados pelo do tratamento antirretroviral.

Custos diretos com tratamento do VIH/SIDA em Portugal

OBJETIVO Analisar dos custos diretos medicos com VIH/SIDA, de acordo com a perspetiva do Servico Nacional de Saude, em Portugal. METODOS Efetuou-se analise retrospectiva de registros medicos em amostra de 150 pacientes de cinco centros especializados em 2008. Foram obtidos dados de utilizacao de recursos medicos durante 12 meses e das caracteristicas dos pacientes nesse periodo. Aplicou-se o custo unitario a cada componente de custo, usando fontes oficiais e dados contabilisticos dos hospitais. RESULTADOS O custo medio anual de tratamento foi de 14.277 euros por paciente. A parcela de custo mais importante foi o custo com o tratamento antirretroviral (9.598 euros), seguido dos custos de internacao (1.323 euros). Os custos de tratamento com severidade aumentaram de 11.901 euros (> 500 CD4 celulas/µl) para 23.351 euros (CD4 ≤ 50 celulas/µl). A progressao dos custos deve-se principalmente ao aumento dos custos de internacao, dado que os custos com tratamento antirretroviral se mantem constantes ao longo dos estadios. CONCLUSOES O custo elevado do tratamento antirretroviral e compensado com o custo relativamente baixo da internacao, apesar deste aumentar com a severidade. A baixa progressao dos custos totais revela que estrategias de saude publica alternativas que nao alterem a transmissao da doenca terao apenas impacto limitado nas despesas, dado que os custos sao largamente influenciados pelo do tratamento antirretroviral.