Evaluation of Local & Global Ductility Relationships for Low-Rise Masonry-Infilled Reinforced Concrete Frame Structures

The paper presents the findings on a parametric study of the period lengthening effects of low-rise masonryinfilled reinforced concrete frame buildings using an incremental dynamic analysis (IDA). Simplified 2D building models utilizing Bouc-Wen model for describing strength, stiffness degradation and pinching effect were subjected to some selected ground motion records ranging from far to near field earthquakes in low to high seismicity regions. Simple equations correlating local to global ductilities derived from pushover (PO) analysis for buildings under soft storey failure mechanism are proposed. The equations take into account the governing factors like critical interstorey drift and number of storeys. The applicability of the equations was verified up to 7-storey buildings from the results of IDA. Such simple ductility relationships are likely to facilitate mostly the coefficient-based method, in which the typical PO analysis may be bypassed and allows making intuitive insight into the seismic performance of buildings.published_or_final_versio

Typical collapse modes of confined masonry buildings under strong earthquake loads

Confined masonry structures are a widely applied structural system in many developing countries. During the past Wenchuan Earthquake in 2008, numerous confined masonry buildings collapsed, while many others suffered damage. This study reviews the construction practices of confined masonry buildings in China. Simple models and hand calculation methods are proposed for quantifying the tearing failure of diaphragms, the tensile failure of tie-columns and the sway-mode strength of masonry buildings. The results indicate very good agreement with field observations. The seismic measures that are stipulated in the seismic design codes are very effective for increasing the strength and integrity, but not the ductility of masonry buildings. For those buildings that survived the earthquake, strength rather than ductility protected the confined masonry from collapse or serious damage. Design recommendations are suggested for preventing various types of premature failures and enhancing the lateral strength of masonry buildings. © Su et al.published_or_final_versio

Knowledge-based identification of sleep stages based on two forehead electroencephalogram channels

© 2014 Huang, Lin, Ko, Liu, Su and Lin. Sleep quality is important, especially given the considerable number of sleep-related pathologies. The distribution of sleep stages is a highly effective and objective way of quantifying sleep quality. As a standard multi-channel recording used in the study of sleep, polysomnography (PSG) is a widely used diagnostic scheme in sleep medicine. However, the standard process of sleep clinical test, including PSG recording and manual scoring, is complex, uncomfortable, and time-consuming. This process is difficult to implement when taking the whole PSG measurements at home for general healthcare purposes. This work presents a novel sleep stage classification system, based on features from the two forehead EEG channels FP1 and FP2. By recording EEG from forehead, where there is no hair, the proposed system can monitor physiological changes during sleep in a more practical way than previous systems. Through a headband or self-adhesive technology, the necessary sensors can be applied easily by users at home. Analysis results demonstrate that classification performance of the proposed system overcomes the individual differences between different participants in terms of automatically classifying sleep stages. Additionally, the proposed sleep stage classification system can identify kernel sleep features extracted from forehead EEG, which are closely related with sleep clinician's expert knowledge. Moreover, forehead EEG features are classified into five sleep stages by using the relevance vector machine. In a leave-one-subject-out cross validation analysis, we found our system to correctly classify five sleep stages at an average accuracy of 76.7 ± 4.0 (SD) % [average kappa 0.68 ± 0.06 (SD)]. Importantly, the proposed sleep stage classification system using forehead EEG features is a viable alternative for measuring EEG signals at home easily and conveniently to evaluate sleep quality reliably, ultimately improving public healthcare

Secondary structure in the core of amyloid fibrils formed from human βm and its truncated variant Δn6

Amyloid fibrils formed from initially soluble proteins with diverse sequences are associated with an array of human diseases. In the human disorder, dialysis-related amyloidosis (DRA), fibrils contain two major constituents, full-length human β-microglobulin (hβm) and a truncation variant, ΔN6 which lacks the N-terminal six amino acids. These fibrils are assembled from initially natively folded proteins with an all antiparallel β-stranded structure. Here, backbone conformations of wild-type hβm and ΔN6 in their amyloid forms have been determined using a combination of dilute isotopic labeling strategies and multidimensional magic angle spinning (MAS) NMR techniques at high magnetic fields, providing valuable structural information at the atomic-level about the fibril architecture. The secondary structures of both fibril types, determined by the assignment of ∼80% of the backbone resonances of these 100- and 94-residue proteins, respectively, reveal substantial backbone rearrangement compared with the location of β-strands in their native immunoglobulin folds. The identification of seven β-strands in hβm fibrils indicates that approximately 70 residues are in a β-strand conformation in the fibril core. By contrast, nine β-strands comprise the fibrils formed from ΔN6, indicating a more extensive core. The precise location and length of β-strands in the two fibril forms also differ. The results indicate fibrils of ΔN6 and hβm have an extensive core architecture involving the majority of residues in the polypeptide sequence. The common elements of the backbone structure of the two proteins likely facilitates their ability to copolymerize during amyloid fibril assembly

Application of the x-ray measurement model to image processing of x-ray radiographs

A computational model has been developed at which simulates the film response to the interaction of x-rays with a sample[1,2]. By using a CAD model as a virtual part, film densities of the radiograph are predicted. The number of photons which reach the film is based on the thickness of the part, part geometry, and the material absorption coefficient. Also taken into consideration are the x-ray beam characteristics, film properties, and the experimental configuration. The model generated images can vary in size and resolution, depending on the user chosen parameters. Noise is calculated using a Gaussian noise distribution and adjusted for the film type. The result of this simulation is a two-dimensional numerically generated digital image, which represents a radiograph of the part. This result can be used to analyze the flaws in an actual radiograph with the same set-up and exposure parameters

Erosion characteristics and floc strenght of Athabasca river cohesive sediments: towards managing sediment-related issues

Purpose: Most of Canada’s tar sands exploitations are located in the Athabasca river basin. Deposited cohesive sediments in Athabasca river and tributaries are a potential source of PAHs in the basin. Erosional behavior of cohesive sediments depends not only of fluid turbulence but on sediments structure and particularly the influence of organic content. This research tries to describe this behavior in Athabasca river sediments. Methods: An experimental study of cohesive sediments dynamics in one of the tributaries, the Muskeg river, was developed in a rotating annular flume. Variation of the shear stress allowed the determination of erosional strength for beds with different consolidation periods. Particle size measurements were made with a laser diffraction device operated in a continuous flow through mode. Optical analyses of flocs (ESEM and TEM) were performed with samples taken at the end of the experiments. Results: An inverse relationship between suspended sediment concentration (SS) and the consolidation period was found. The differences are related in this research to the increasing organic content of the sediments with consolidation period. The particle size measurements during the experiments showed differences on floc strength that are also related to changing organic content during different consolidation periods. ESEM and TEM observations confirm the structural differences for beds with different consolidation periods. The effects of SFGL on floc structure and in biostabilization of the bed are discussed. Conclusions: It is recommended in this paper that consolidation period should be taken into account for the modeling of erosion of cohesive sediments in the Athabasca river. Relating to transport models of pollutants (PAHs) it is highly recommended to consider flocs organic content, particularly algae, in the resuspension module.Environment Canada, CONACY

Inibidores de urease, serapilheira e adensamento do cafeeiro arábica: relações com a matéria orgânica do solo

O uso de tecnologias nas lavouras cafeeiras deve proporcionar melhorias nas condições de manejo, auxiliar na produção vegetal e promover qualidade ao solo e meio ambiente. Neste sentido, as tecnologias fertilizantes inibidores de urease, serapilheira foliar cafeeira e o adensamento cafeeiro foram avaliados atendendo há problemáticas no manejo das lavouras de cafeicultores familiares do Território do Caparaó- ES. O capítulo 1 teve por objetivo verificar o potencial dos inibidores de urease quanto à redução da volatilização NH3 e emissão de CO2 do solo, bem como avaliar a atividade da enzima urese do solo e a influência dos inibiores de urease sobre a matéria orgânica do solo. Os inibidores de urease NBPT e Cu+B mostraram ser promissores na redução da volatilização da NH3, principalmente o NBPT que volatilizou, em função das doses avaliadas, de 1,4 a 5,6 % do total de N aplicado. O efluxo de CO2 seguiu a ordem: Uréia> Uréia+Cu+B > Uréia+NBPT. De modo semelhante, os inibidores de urease reduziram a atividade da enzima urease do solo, sendo a uréia comum, o tratamento que proporcionou maior atividade da enzima. Apesar das fontes e doses de N não influenciarem sobre os teores de C orgânica do solo, verificou-se redução de 5,1 % no seu teor médio dos 16 para os 32 dias, ou seja, um curto período de tempo tem promovido redução na matéria orgânica do solo. O capítulo 2 teve por objetivo verificar o efeito da associação inibidores de urease e serapilheira sobre a volatilização da amônia e emissão de CO2 bem como a taxa de decomposição e liberação de nutrientes da serapilheira e seu efeito na matéria orgânica do solo. A ordem de volatilização da NH3 e emissão de CO2 foi: Uréia> Uréia+Cu+B > Uréia+NBPT. Contudo, o aumento da dose de serapilheira proporciona menor emissão de NH3, porém, maior emissão de CO2 (y=0,95x+3,82). Na dose equivalente a 4,5 Mg ha-1 de serapilheira e após 64 dias de decomposição, a quantidade liberada de C, N, P, K, Ca e Mg foi equivalente a 547,1; 49,0; 1,28; 17,4; 18,2 e 5,0 kg ha-1, respectivamente. Fontes de N e doses de serapilheira não influenciaram no teor de C orgânico total e N total do solo, entretanto, dos 16 aos 64 dias após a aplicação da serapilheira ocorreu redução nos seus teores em 15,4 e 21,1 %, respectivamente. O capítulo 3 teve por objetivo avaliar o efeito dos inibidores de urease juntamente com a serapilheira foliar cafeeira sobre os parâmetros biométricos, teor e acúmulo de N, atividade da urease foliar e % de clorofila no desenvolvimento inicial do cafeeiro IAC 144. Independente da fonte de N avaliada, a dose de 1,2 g vaso-1 de N foi suficiente para proporcionar altura da planta, diâmetro do caule, número de nós, pares de folhas, ramos plagiotrópicos e massa seca igual ou superiores as demais doses. Maiores teores de N foliar foram proporcionados pelos inibidores de urease e na maior dose aplicada impactando também, em maior atividade da enzima urease na folha. Não é recomendada a utilização de serapilheira no plantio do cafeeiro, pois ela proporcionou redução de 9,1; 3,3; 10,5 e 19,3 % na altura, número de nós, diâmetro do caule e número de ramos plagiotrópicos, respectivamente, e reduziu a produção de massa seca e o acúmulo de N na parte aérea. Fontes, doses de N e a serapilheira não influenciaram os teores de clorofila, entretanto, aumento dos teores de clorofila foram verificadas ao longo do tempo após a adubação nitrogenada. Já em condições de campo, o capítulo 4 da tese teve por objetivo determinar a influência do adensamento da lavoura cafeeira sobre os teores e estoques de COT e NT do solo, C e N da biomassa microbiana, matéria orgânica leve, labilidade da matéria orgânica do solo, as substâncias húmicas, densidade, porosidade e as emissões de CO2, temperatura e umidade do solo na região montanhosa do Território do Caparaó - Espírito Santo. O manejo cafeeiro adensado (8333 plantas ha-1) proporcionou aumento da MOL e C-MOL, menor densidade do solo, maior macroporosidade e porosidade total em relação ao cafeeiro convencional (3105 plantas ha-1). Épocas quentes e úmidas do ano favorecem as emissões de CO2 do solo, entretanto, o manejo do cafeeiro sob sistema adensado é o sistema que proporcionou menores emissões de CO2 do solo. A maior quantidade de serapilheira cafeeira do sistema adensado não estimula a atividade microbiológica do solo, entretanto, protege o solo contra erosão, aumenta a umidade e reduz a amplitude térmica. Palavras-chave: Espaçamento, agricultura familiar, volatilização, fertilizantes nitrogenados, Território do Capara

Breast cancer risk reduction:is it feasible to initiate a randomised controlled trial of a lifestyle intervention programme (ActWell) within a national breast screening programme?

BackgroundBreast cancer is the most commonly diagnosed cancer and the second cause of cancer deaths amongst women in the UK. The incidence of the disease is increasing and is highest in women from least deprived areas. It is estimated that around 42% of the disease in post-menopausal women could be prevented by increased physical activity and reductions in alcohol intake and body fatness. Breast cancer control endeavours focus on national screening programmes but these do not include communications or interventions for risk reductionThis study aimed to assess the feasibility of delivery, indicative effects and acceptability of a lifestyle intervention programme initiated within the NHS Scottish Breast Screening Programme (NHSSBSP).MethodsA 1:1 randomised controlled trial (RCT) of the 3 month ActWell programme (focussing on body weight, physical activity and alcohol) versus usual care conducted in two NHSSBSP sites between June 2013 and January 2014. Feasibility assessments included recruitment, retention, and fidelity to protocol. Indicative outcomes were measured at baseline and 3 month follow-up (body weight, waist circumference, eating and alcohol habits and physical activity. At study end, a questionnaire assessed participant satisfaction and qualitative interviews elicited women¿s, coaches and radiographers¿ experiences. Statistical analysis used Chi squared tests for comparisons in proportions and paired t tests for comparisons of means. Linear regression analyses were performed, adjusted for baseline values, with group allocation as a fixed effectResultsA pre-set recruitment target of 80 women was achieved within 12 weeks and 65 (81%) participants (29 intervention, 36 control) completed 3 month assessments. Mean age was 58¿±¿5.6 years, mean BMI was 29.2¿±¿7.0 kg/m2 and many (44%) reported a family history of breast cancer.The primary analysis (baseline body weight adjusted) showed a significant between group difference favouring the intervention group of 2.04 kg (95%CI ¿3.24 kg to ¿0.85 kg). Significant, favourable between group differences were also detected for BMI, waist circumference, physical activity and sitting time. Women rated the programme highly and 70% said they would recommend it to others.ConclusionsRecruitment, retention, indicative results and participant acceptability support the development of a definitive RCT to measure long term effects.Trial registrationThe trial was registered with Current Controlled Trials (ISRCTN56223933)

Identification of QTL genes for BMD variation using both linkage and gene-based association approaches

Low bone mineral density (BMD) is a risk factor for osteoporotic fracture with a high heritability. Previous large scale linkage study in Northern Chinese has identified four significant quantitative trait loci (QTL) for BMD variation on chromosome 2q24, 5q21, 7p21 and 13q21. We performed a replication study of these four QTL in 1,459 Southern Chinese from 306 pedigrees. Successful replication was observed on chromosome 5q21 for femoral neck BMD with a LOD score of 1.38 (nominal p value = 0.006). We have previously identified this locus in a genome scan meta-analysis of BMD variation in a white population. Subsequent QTL-wide gene-based association analysis in 800 subjects with extreme BMD identified CAST and ERAP1 as novel BMD candidate genes (empirical p value of 0.032 and 0.014, respectively). The associations were independently replicated in a Northern European population (empirical p value of 0.01 and 0.004 for CAST and ERAP1, respectively). These findings provide further evidence that 5q21 is a BMD QTL, and CAST and ERAP1 may be associated with femoral neck BMD variation

A Novel Unsupervised Method to Identify Genes Important in the Anti-viral Response: Application to Interferon/Ribavirin in Hepatitis C Patients

Background: Treating hepatitis C with interferon/ribavirin results in a varied response in terms of decrease in viral titer and ultimate outcome. Marked responders have a sharp decline in viral titer within a few days of treatment initiation, whereas in other patients there is no effect on the virus (poor responders). Previous studies have shown that combination therapy modifies expression of hundreds of genes in vitro and in vivo. However, identifying which, if any, of these genes have a role in viral clearance remains challenging. Aims: The goal of this paper is to link viral levels with gene expression and thereby identify genes that may be responsible for early decrease in viral titer. Methods: Microarrays were performed on RNA isolated from PBMC of patients undergoing interferon/ribavirin therapy. Samples were collected at pre-treatment (day 0), and 1, 2, 7, 14 and 28 days after initiating treatment. A novel method was applied to identify genes that are linked to a decrease in viral titer during interferon/ribavirin treatment. The method uses the relationship between inter-patient gene expression based proximities and inter-patient viral titer based proximities to define the association between microarray gene expression measurements of each gene and viral-titer measurements. Results: We detected 36 unique genes whose expressions provide a clustering of patients that resembles viral titer based clustering of patients. These genes include IRF7, MX1, OASL and OAS2, viperin and many ISG's of unknown function. Conclusion: The genes identified by this method appear to play a major role in the reduction of hepatitis C virus during the early phase of treatment. The method has broad utility and can be used to analyze response to any group of factors influencing biological outcome such as antiviral drugs or anti-cancer agents where microarray data are available. © 2007 Brodsky et al