78 research outputs found
Anisotropic behaviour of human gallbladder walls
Inverse estimation of biomechanical parameters of soft tissues from non-invasive measurements has clinical significance in patient-specific modelling and disease diagnosis. In this paper, we propose a fully nonlinear approach to estimate the mechanical properties of the human gallbladder wall muscles from in vivo ultrasound images. The iteration method consists of a forward approach, in which the constitutive equation is based on a modified Hozapfel–Gasser–Ogden law initially developed for arteries. Five constitutive parameters describing the two orthogonal families of fibres and the matrix material are determined by comparing the computed displacements with medical images. The optimisation process is carried out using the MATLAB toolbox, a Python code, and the ABAQUS solver. The proposed method is validated with published artery data and subsequently applied to ten human gallbladder samples. Results show that the human gallbladder wall is anisotropic during the passive refilling phase, and that the peak stress is 1.6 times greater than that calculated using linear mechanics. This discrepancy arises because the wall thickness reduces by 1.6 times during the deformation, which is not predicted by conventional linear elasticity. If the change of wall thickness is accounted for, then the linear model can used to predict the gallbladder stress and its correlation with pain. This work provides further understanding of the nonlinear characteristics of human gallbladder
Impact of mass distribution of free long-lasting insecticidal nets on childhood malaria morbidity: The Togo National Integrated Child Health Campaign
<p>Abstract</p> <p>Background</p> <p>An evaluation of the short-term impact on childhood malaria morbidity of mass distribution of free long-lasting insecticidal nets (LLINs) to households with children aged 9-59 months as part of the Togo National Integrated Child Health Campaign.</p> <p>Methods</p> <p>The prevalence of anaemia and malaria in children aged zero to 59 months was measured during two cross-sectional household cluster-sample surveys conducted during the peak malaria transmission, three months before (Sept 2004, n = 2521) and nine months after the campaign (Sept 2005, n = 2813) in three districts representative of Togo's three epidemiological malaria transmission regions: southern tropical coastal plains (Yoto), central fertile highlands (Ogou) and northern semi-arid savannah (Tone).</p> <p>Results</p> <p>In households with children <5 years of age, insecticide-treated net (ITN) ownership increased from <1% to >65% in all 3 districts. Reported ITN use by children during the previous night was 35.9%, 43.8% and 80.6% in Yoto, Ogou and Tone, respectively. Rainfall patterns were comparable in both years. The overall prevalence of moderate to severe anaemia (Hb < 8.0 g/dL) was reduced by 28% (prevalence ratio [PR] 0.72, 95% CI 0.62-0.84) and mean haemoglobin was increased by 0.35 g/dL (95% CI 0.25-0.45).</p> <p>The effect was predominantly seen in children aged 18-59 months and in the two southern districts: PR (95% CI) for moderate to severe anaemia and clinical malaria: Yoto 0.62 (0.44-0.88) and 0.49 (0.35-0.75); Ogou 0.54 (0.37-0.79) and 0.85 (0.57-1.27), respectively. Similar reductions occurred in children <18 months in Ogou, but not in Yoto. No effect was seen in the semi-arid northern district despite a high malaria burden and ITN coverage.</p> <p>Conclusions</p> <p>A marked reduction in childhood malaria associated morbidity was observed in the year following mass distribution of free LLINs in two of the three districts in Togo. Sub-national level impact evaluations will contribute to a better understanding of the impact of expanding national malaria control efforts.</p
High prevalence of germline STK11 mutations in Hungarian Peutz-Jeghers Syndrome patients
<p>Abstract</p> <p>Background</p> <p>Peutz-Jeghers syndrome (PJS) is a rare autosomal dominantly inherited disease characterized by gastrointestinal hamartomatous polyposis and mucocutaneous pigmentation. The genetic predisposition for PJS has been shown to be associated with germline mutations in the <it>STK11</it>/<it>LKB1 </it>tumor suppressor gene. The aim of the present study was to characterize Hungarian PJS patients with respect to germline mutation in <it>STK11</it>/<it>LKB1 </it>and their association to disease phenotype.</p> <p>Methods</p> <p>Mutation screening of 21 patients from 13 PJS families were performed using direct DNA sequencing and multiplex ligation-dependent probe amplification (MLPA). Comparative semi-quantitative sequencing was applied to investigate the mRNA-level effects of nonsense and splice-affecting mutations.</p> <p>Results</p> <p>Thirteen different pathogenic mutations in <it>STK11</it>, including a high frequency of large genomic deletions (38%, 5/13), were identified in the 13 unrelated families studied. One of these deletions also affects two neighboring genes (<it>SBNO2 </it>and <it>GPX4</it>), located upstream of <it>STK11</it>, with a possible modifier effect. The majority of the point mutations (88%, 7/8) can be considered novel. Quantification of the <it>STK11 </it>transcript at the mRNA-level revealed that the expression of alleles carrying a nonsense or frameshift mutation was reduced to 30-70% of that of the wild type allele. Mutations affecting splice-sites around exon 2 displayed an mRNA processing pattern indicative of co-regulated splicing of exons 2 and 3.</p> <p>Conclusions</p> <p>A combination of sensitive techniques may assure a high (100%) <it>STK11 </it>mutation detection frequency in PJS families. Characterization of mutations at mRNA level may give a deeper insight into the molecular consequences of the pathogenic mutations than predictions made solely at the genomic level.</p
PAMELA Observation of the 2012 May 17 GLE Event
The PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) satellite-borne experiment has been collecting data in orbit since July 2006, providing accurate measurements of the energy spectra and composition of the cosmic radiation from a few hundred MeVn up to hundred GeVn. This wide interval of measured energies makes PAMELA a unique instrument for Solar Energetic Particle (SEP) observations. Not only does it span the energy range between the ground-based neutron monitor data and the observations of SEPs from space, but also PAMELA carries out the first direct measurements of the composition for the highest energy SEP events, including those causing Ground Level Enhancements (GLEs). PAMELA has registered many SEP events in solar cycle 24 including the 2012 May 17 GLE event (GLE 71), offering unique opportunities to address the question of high-energy SEP origin. Experimental performances and preliminary results on the 2012 May 17 events will be presented. We will discuss the derived particle injection time and compare with other time scales at the Sun including the flare and CME onset times
The ethical contours of research in crisis settings: five practical considerations for academic institutional review boards and researchers.
The number of research studies in the humanitarian field is rising. It is imperative, therefore, that institutional review boards (IRBs) consider carefully the additional risks present in crisis contexts to ensure that the highest ethical standards are upheld. Ethical guidelines should represent better the specific issues inherent to research among populations grappling with armed conflict, disasters triggered by natural hazards, or health-related emergencies. This paper seeks to describe five issues particular to humanitarian settings that IRBs should deliberate and on which they should provide recommendations to overcome associated challenges: staged reviews of protocols in acute emergencies; flexible reviews of modification requests; addressing violence and the traumatic experiences of participants; difficulties in attaining meaningful informed consent among populations dependent on aid; and ensuring reviews are knowledgeable of populations' needs. Considering these matters when reviewing protocols will yield more ethically sound research in humanitarian settings and hold researchers accountable to appropriate ethical standards
Post-Truth: An Alumni Economist’s Perspective
Drawing upon 50 years as an academic economist, this lecture to alumni of SOAS’s Department of Economics reflects upon the continual ‘post-truth’ aspects of mainstream economics, ranging over its substantive, if shifting, content, and its treatment of methodology and interdisciplinarity. It draws upon a wide range of theory, empirical analysis, policy and anecdote to highlight both the need for alternatives and the continuing, even increased, failure of the mainstream to engage with criticism and alternatives
Caracterização da queixa escolar no Centro de Psicologia Aplicada da Universidade Federal de Juiz de Fora
A queixa escolar vem se constituindo, historicamente, como um dos motivos mais frequentes de encaminhamentos de crianças para os serviços-escola de Psicologia, traduzindo, pela sua complexidade, um desafio para a formação e práticas no âmbito da psicologia escolar/educacional. Diante da necessidade de aperfeiçoar o atendimento à clientela e o processo de triagem, o presente estudo objetivou analisar os prontuários referentes à queixa escolar de pacientes atendidos no Centro de Psicologia Aplicada da Universidade Federal de Juiz de Fora, Minas Gerais, Brasil, num total de 1.590 documentos, no período de 1996 a 2009. Os resultados quanto à clientela evidenciaram a prevalência de meninos na faixa entre 9 e 13 anos de idade, com predomínio de encaminhamentos oriundos de escolas de periférias da cidade. Quanto à queixa, constatou-se expressiva coocorrência de problemas comportamentais e de aprendizagem. Os dados permitem uma reflexão crítica acerca da queixa escolar e de alguns fatores contextuais, bem como a necessidade de aperfeiçoamento da ficha de triagem
Thyroid cancer complicating familial adenomatous polyposis: mutation spectrum of at-risk individuals
AVALIAÇÃO DOS BENEFÍCIOS DO PILATES NO SOLO EM MULHERES COM LOMBALGIAS NA FAIXA ETÁRIA DE 40 A 60 ANOS
O objetivo do estudo foi verificar os efeitos e possíveis benefícios do Método Pilates em solo em mulheres que apresentavam lombalgias. Foram incluídos no estudo 20 mulheres com idade entre 40 e 60 anos e diagnóstico clínico de lombalgia crônica. Foram aplicados o questionário de identificação OswestryLow BackPainDisability(QO) e de intensidade da dor avaliado pela escala visual analógica da dor. Foi observada uma significativa redução da intensidade de dor lombar de 3,7 para 2,1, o que demonstrou redução da sintomatologia dolorosa das participantes e também observamos melhora nas atividades diárias e diminuição das queixas de lombalgias demonstrando que o Método Pilates tem um importante papel na melhora da dor lombar e da qualidade de vida
Lack of association between the A118G polymorphism of the mu opioid receptor gene (OPRMI) and opioid defendence: A meta-analysis
Mu opioid receptor (OPRM1) gene variants, particularly the common A118G single nucleotide polymorphism (SNP), are among the most frequently studied candidate genes associated with opioid dependence. However, despite numerous case-control studies and meta-analyses, no definitive conclusion has been reached regarding the association of the A118G SNP and risk of developing opioid dependence. This study aimed to resolve this discrepancy by reinvestigating the association between A118G SNP allelic, and for the first time, genotype frequencies and opioid dependence. A meta-analysis of sixteen case-control studies of opioid dependence was performed with a total of 5169 subjects. No association between the A118G allele (P = 0.23) and genotype (P = 0.34) frequencies and opioid dependence was found. However, significant heterogeneity between studies precluded highly definitive conclusions. In addition, the possibility that other OPRM1 SNPs albeit rarer may influence the risk of opioid dependence remains to be investigated at this level. Nonetheless, despite no evidence of a direct association with risk of dependence, A118G may still influence the pharmacological response to opioids impacting on an individual’s dosage requirements.Janet K Coller, Julia Beardsley, James Bignold, Yibai Li, Florence Merg, Thomas Sullivan, Timothy C Cox and Andrew A Somogy
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