Superefficiency and Multiplier Adjustment in Data Envelopment Analysis

Copyright © 2013 Springer Netherlands.

Reliability of nasal auscultation and their relation to middle ear condition – a clinical interest to pediatrics respiratory physiotherapy

Background: Acute respiratory infections are usual in children under three years old occurring in upper respiratory tract, having an impact on child and caregiver’s quality of life predisposing to otitis media or bronchiolitis. There are few valid and reliable measures to determine the child’s respiratory condition and to guide the physiotherapy intervention. Aim: To assess the intra and inter rater reliability of nasal auscultation, to analyze the relation between sounds’ classification and middle ear’s pressure and compliance as well as with the Clinical Severity Score. Methods: A cross-sectional observational study was composed by 125 nursery children aged up to three years old. Tympanometry, pulmonary and nasal auscultation and application of Clinical Severity Score were performed to each child. Nasal auscultation sounds’ were recorded and sent to 3 blinded experts, that classified, as “obstructed” and “unobstructed”, with a 48 hours interval, in order to analyze inter and intra rater reliability. Results: Nasal auscultation revealed a substantial inter and intra rater reliability (=0,749 and evaluator A - K= 0,691; evaluator B - K= 0,605 and evaluator C - K= 0,724, respectively). Both ears’ pressure was significantly lower in children with an "unobstructed" nasal sound when compared with an “obstructed” nasal sound (t=-3,599, p<0,001 in left ear; t=-2,258, p=0,026 in right ear). Compliance in both ears was significantly lower in children with an "obstructed" nasal sound when compared with “unobstructed” nasal sound (t=-2,728, p=0,007 in left ear; t=-3,830, p<0,001 in right ear). There was a statistically significant association between sounds’ classification and tympanograms types in both ear’s (=11,437, p=0,003 in left ear; =13,535, p=0,001 in right ear). There was a trend to children with an "unobstructed" nasal sound that had a lower clinical severity score when compared with “obstructed” children. Conclusion: It was observed a good intra and substantial inter reliability for nasal auscultation. Nasal auscultation sounds’ classification was related to middle ears’ pressure and compliance.

A hybrid MLS technique for room impulse response estimation

The measurement of room impulse response (RIR) when there are high background noise levels frequently means one must deal with very low signal-to-noise ratios (SNR). if such is the case, the measurement might yield unreliable results, even when synchronous averaging techniques are used. Furthermore, if there are non-linearities in the apparatus or system time variances, the final SNR can be severely degraded. The test signals used in RIR measurement are often disturbed by non-stationary ambient noise components. A novel approach based on the energy analysis of ambient noise - both in the time and in frequency - was considered. A modified maximum length sequence (MLS) measurement technique. referred to herein as the hybrid MLS technique, was developed for use in room acoustics. The technique consists of reducing the noise energy of the captured sequences before applying the averaging technique in order to improve the overall SNRs and frequency response accuracy. Experiments were conducted under real conditions with different types of underlying ambient noises. Results are shown and discussed. Advantages and disadvantages of the hybrid MLS technique over standard MLS technique are evaluated and discussed. Our findings show that the new technique leads to a significant increase in the overall SNR. (C) 2008 Elsevier Ltd. All rights reserved.

Hepatite C em profissionais da saúde: prevalência e associação com fatores de risco

OBJETIVO: Avaliar a prevalência do vírus da hepatite entre profissionais da área da saúde e analisar fatores de risco. MÉTODOS: O estudo foi realizado em hospital universitário no município de São José do Rio Preto, SP, de janeiro 1994 a dezembro 1999. Participaram do estudo 1.433 profissionais da área da saúde, 872 funcionários da área administrativa e 2.583 candidatos a doador de sangue. Os dados foram coletados durante exames admissionais, periódicos e após acidentes de trabalho. Informações ocupacionais e não-ocupacionais foram obtidas por meio de questionário. Foram utilizados os testes qui-quadrado, Kruskal-Wallis e análise por regressão logística. RESULTADOS: A prevalência do vírus da hepatite entre os profissionais da saúde (1,7%) foi significativamente maior que nos funcionários administrativos (0,5%; p=0,007) e em candidatos a doadores (0,2%; p=0,001). Entre fatores ocupacionais, o tempo de serviço dos profissionais da saúde com sorologia positiva foi significativamente maior (p=0,016) que naqueles com sorologia negativa. A análise de regressão múltipla revelou que a cada cinco anos na idade, o risco aumenta em 50%. Houve associação significativa entre transfusão de sangue e profissionais de saúde com sorologia positiva. CONCLUSÕES: Profissionais da saúde apresentaram maior prevalência de vírus da hepatite que os profissionais administrativos e candidatos a doador. Naqueles com sorologia positiva, fatores ocupacionais e não-ocupacionais de maior risco foram idade, tempo de serviço e transfusão de sangue.

Monte Carlo simulation of the basic features of the GE Millennium MG single photon emission computed tomography gamma camera

Objective - To describe and validate the simulation of the basic features of GE Millennium MG gamma camera using the GATE Monte Carlo platform. Material and methods - Crystal size and thickness, parallel-hole collimation and a realistic energy acquisition window were simulated in the GATE platform. GATE results were compared to experimental data in the following imaging conditions: a point source of 99mTc at different positions during static imaging and tomographic acquisitions using two different energy windows. The accuracy between the events expected and detected by simulation was obtained with the Mann–Whitney–Wilcoxon test. Comparisons were made regarding the measurement of sensitivity and spatial resolution, static and tomographic. Simulated and experimental spatial resolutions for tomographic data were compared with the Kruskal–Wallis test to assess simulation accuracy for this parameter. Results - There was good agreement between simulated and experimental data. The number of decays expected when compared with the number of decays registered, showed small deviation (≤0.007%). The sensitivity comparisons between static acquisitions for different distances from source to collimator (1, 5, 10, 20, 30cm) with energy windows of 126–154 keV and 130–158 keV showed differences of 4.4%, 5.5%, 4.2%, 5.5%, 4.5% and 5.4%, 6.3%, 6.3%, 5.8%, 5.3%, respectively. For the tomographic acquisitions, the mean differences were 7.5% and 9.8% for the energy window 126–154 keV and 130–158 keV. Comparison of simulated and experimental spatial resolutions for tomographic data showed no statistically significant differences with 95% confidence interval. Conclusions - Adequate simulation of the system basic features using GATE Monte Carlo simulation platform was achieved and validated.

Nutritional status and overhydration: can bioimpedance spectroscopy be useful in haemodialysis patients?

Background: Protein-energy wasting (PEW), associated with inflammation and overhydration, is common in haemodialysis (HD) patients and is associated with high morbidity and mortality. Objective: Assess the relationship between nutritional status, markers of inflammation and body composition through bioimpedance spectroscopy (BIS) in HD patients. Methods: This observational, cross-sectional, single centre study, carried out in an HD centre in Forte da Casa (Portugal), involved 75 patients on an HD programme. In all participating patients, the following laboratory tests were conducted: haemoglobin, albumin, C-reactive protein (CRP) and 25-hydroxyvitamin D3 [25(OH)D3]. The body mass index of all patients was calculated and a modified version of subjective global assessment (SGA) was produced for patients on dialysis. Intracellular water (ICW) and extracellular water (ECW) were measured by BIS (Body Composition Monitor®, Fresenius Medical Care®) after the HD session. In statistical analysis, Spearman’s correlation was used for the univariate analysis and linear regression for the multivariate analysis (SPSS 14.0). A P value of <.05 was considered statistically significant. Results: PEW, inversely assessed through the ICW/body weight (BW) ratio, was positively related to age (P<.001), presence of diabetes (P=.004), BMI (P=.01) and CRP (P=.008) and negatively related to albumin (p=.006) and 25(OH)D3 (P=.007). Overhydration, assessed directly through the ECW/BW ratio, was positively related with CRP (P=.009) and SGA (P=.03), and negatively with 25(OH)D3 (P=.006) and BMI (P=.01). In multivariate analysis, PEW was associated with older age (P<.001), the presence of diabetes (P=.003), lower 25(OH)D3 (P=.008), higher CRP (P=.001) and lower albumin levels (P=.004). Over-hydration was associated with higher CRP (P=.001) and lower levels of 25(OH)D3 (P=.003). Conclusions: Taking these results into account, the ICW/BW and ECW/BW ratios, assessed with BIS, have proven to be good markers of the nutritional and inflammatory status of HD patients. BIS may be a useful tool for regularly assessing the nutritional and hydration status in these patients and may allow nutritional advice to be improved and adjusted.

Endothelial lipase correlated positively with EPA/AA ratio in RBCs membrane

The fatty acid profile of erythrocyte membranes has been considered a good biomarker for several pathologic situations. Dietary intake, digestion, absorption, metabolism, storage and exchange amongst compartments, greatly influence the fatty acids composition of different cells and tissues. Lipoprotein and hepatic lipases were also involved in fatty acid availability. In the present work we examined the correlations between fatty acid in Red Blood Cells (RBCs) membranes, the fatty acid desaturase and elongase activities, glycaemia, blood lipids, lipoproteins and apoproteins, and the endothelial lipase (EL) mass in plasma. Twenty one individuals were considered in the present study, with age >18 y. RBCs membranes were obtained and analysed for fatty acid composition by gas chromatography. The amount of fatty acids (as percentage) were analysed, and the ratios between fatty acid 16:1/16:0; 18:1/18:0; 18:0/16:0; 22:6 n-3/20:5 n-3 and 20:4 n-6/18:2 n-6 were calculated. Bivariate analysis (rs) and partial correlations were determined. SCD16 estimation activity correlated positively with BMI (rs=0.466, p=0.043) and triacylglycerols (TAG) (rs=0.483, p=0.026), and negatively with the ratio ApoA1/ApoB (rs=-0.566, p=0.007). Endothelial lipase (EL) correlated positively with the EPA/AA ratio in RBCs membranes (rs=0.524, p=0.045). After multi-adjustment for BMI, age, hs-CRP and dietary n3/n6 ratio, the correlations remained significant between EL and EPA/AA ratio. At the best of our knowledge this is the first report that correlated EL with the fatty acid profile of RBCs plasma membranes. The association found here can suggest that the enzyme may be involved in the bioavailability and distribution of n-3/n-6 fatty acids, suggesting a major role for EL in the pathophysiological mechanisms involving biomembranes’ fatty acids, such as in inflammatory response and eicosanoids metabolites pathways.

Invasion success and development of benthic assemblages: effect of timing, duration of submersion and substrate type

Copyright © 2013 Elsevier Ltd. All rights reserved.

Fibras óticas de plástico em redes de acesso

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Eletrónica e Telecomunicações

Efeito de um treino neuromuscular no tempo de reacção dos peroniais em jovens futebolistas

Objectivo: verificar a influência de um programa neuromuscular de 6 semanas no tempo de reacção dos peroniais, em jovens futebolistas. Métodos: Foi realizado um estudo quasi-experimental, cuja amostra foi constituída por um grupo experimental (n=14) e um de controlo (n=14). O grupo experimental realizou um programa de treino neuromuscular durante 6 semanas, com exercícios terapêuticos, enquanto o grupo controlo continuou com a sua actividade física habitual. Foi utilizado um trapdoor e electromiografia de superfície para avaliar o tempo de reacção dos músculos peroniais antes e após a aplicação do programa de exercícios, em ambos os grupos. O teste t para amostras independentes foi utilizado para comparar o tempo de reacção entre os dois grupos. O teste t para amostras emparelhadas foi efectuado para comparar a média das diferenças entre os dois momentos para ambos os grupos. Ambos os testes foram realizados para um nível de significância de 5%. Resultados: Verificou-se uma diminuição significativa no tempo de reacção do curto (p=0,022) e do longo peronial (p=0,007) no grupo experimental. Conclusão: O programa de treino neuromuscular promoveu uma diminuição do tempo de reacção dos peroniais.

Influência de um programa de exercícios específicos em estudantes de violino

Introdução: A elevada prevalência de problemas musculosqueléticos relacionados com a performance musical (PMRPM) em estudantes universitários de música, sobretudo violinistas, justifica uma abordagem preventiva junto destes, nomeadamente, através do exercício. Este deve ser específico e baseado nos padrões de movimento durante a performance musical do violinista. Objetivos: verificar a influência de um programa de exercícios específicos (PEE) nos sintomas relacionados com a prática musical, na incapacidade funcional e na autoperceção da performance física e musical, em estudantes universitários de violino. Métodos: estudo quase-experimental baseado num estudo piloto com 24 estudantes para pesquisa da sintomatologia, e 4 para análise cinemática e cinética do gesto técnico. No estudo principal participaram 22 violinistas divididos equitativamente, e por disponibilidade, entre grupo experimental (GE) e grupo de controlo (GC). O GE realizou o PEE bissemanalmente, durante 8 semanas. No momento inicial e após 8 semanas, os participantes preencheram: Questionário de Performance (incluiu Escala Visual Analógica), Disabilities of the Arm, Shoulder and Hand, Oswestry Disability Index versão 2.0, Pain Catastrophizing Scale e Escala de Borg Modificada. Resultados: do estudo piloto constatou-se que os sintomas mais frequentes, dor e fadiga, localizavam-se na cintura escapular, ombros e coluna lombar; os ombros aparentavam maior risco de PMRPM; era necessário aumentar a endurance dos mobilizadores dos membros superiores (principalmente deltóide) e relaxar os estabilizadores da coluna cervical (sobretudo trapézio superior). No final do PEE, o GE apresentou significativamente melhores pontuações do que o GC na percentagem de violinistas com “dor na coluna lombar esquerda” (p=0,007), frequência da dor (U=8,5; W=29,5; p=0,016), número de locais com sintomas (U=18; W=84; p=0,003) e amplificação (U=26; W=92; p=0,021). Conclusão: Um PEE pode produzir efeitos positivos na diminuição dos sintomas relacionados com a prática musical e incapacidade funcional, e na melhoria de alguns parâmetros da performance física autoreportada, em estudantes universitários de violino.

O uso do smartphone na avaliação da dorsiflexão da tibiotársica, do passo rápido anterior/lateral/posterior e da marcha em idosos

Introdução: A correta avaliação das capacidades do idoso será fundamental na diminuição do risco de queda inerente ao envelhecimento. Os Smartphones são uma boa ferramenta para a avaliação das capacidades em idosos. Objetivo: Verificar se o smartphone é uma ferramenta de avaliação do ângulo de dorsiflexão ativa da tibiotársica (Dors. TT) e em diferentes parâmetros relacionados com a marcha. ; Métodos: Estudo transversal correlacional, com amostra composta por 27 indivíduos com mais de 60 anos. Procedeu-se à recolha de dados através de um sistema de análise cinemática em 3D com conexão a uma plataforma de forças e de uma aplicação para Smartphone (Fraunhofer®, Porto, Portugal), de forma a verificar a funcionalidade desta última. As variáveis medidas foram a Dors. TT; e todas a variáveis relacionadas com a marcha. Resultados: A dors. TT apresentou uma correlação forte positiva (rs=0,8; p<0,001) entre os dados dos dois instrumentos, assim como no balanço pélvico (rp=0,8; p<0,001), na velocidade na marcha (rp=0,7; p<0,001) e no nº de passos posteriores (rs=0,8; p<0,001). Observou-se uma correlação moderada positiva na duração do passo direito, na duração do passo, na duração da passada, na cadência, no comprimento do passo esq., no comprimento do passo e no deslocamento lateral da pélvis (rp=0,6; p≤0.008). Na percentagem da fase de apoio (%FA) (rs =-0.6; p= 0.007) e na medição da cadência lateral (rs =-0.4; p= 0.042) observou-se uma correlação moderada negativa e na cad. post. (rs=-0,7; p<0,001) uma correlação forte negativa. Conclusão: A aplicação para Smartphone parece ser uma ferramenta útil para avaliar corretamente o ângulo de dorsiflexão da tibiotársica, a contagem do número de passos no sentido posterior, o balanço pélvico e a velocidade. Contudo, necessita ser reajustada para as outras variáveis.

Efeito da razão de submersão sobre os parâmetros hidrodinâmicos de uma coluna de recirculação de líquido através de um tubo exterior

No trabalho realizado nesta tese, procedeu-se ao estudo hidrodinâmico de uma coluna de borbulhamento de recirculação externa do líquido (CREL), que permitiu ampliar o conhecimento já existente sobre este tipo de colunas. Para realizar este estudo utilizaram-se líquidos viscosos Newtonianos, nomeadamente soluções aquosas de glicerina com viscosidades entre 0,007 e 0,522 Pa.s. Para a gama de caudais de ar injectados, 1,5x10-5 até 1,35x10-4 m3/s, o ar ascendia ao longo da coluna de borbulhamento sob a forma de bolhas tubulares. Após a realização dos ensaios, verificou-se que o regime de escoamento do líquido entre bolhas tubulares variou desde o tipo laminar até transição (1,9

Keep calm enfrenta a vergonha : contributos para um programa de competências sócio-emocionais

Trabalho apresentado em XIII Congreso Internacional Galego-Portugués de Psicopedagoxía, Área 1 Aprendizaje, memoria y motivación. Universidad da Coruña, 2 de Setembro de 2015.

10 kVp rule – An anthropomorphic pelvis phantom imaging study using a CR system: impact on image quality and effective dose using AEC and manual mode

Purpose - This study aims to investigate the influence of tube potential (kVp) variation in relation to perceptual image quality and effective dose (E) for pelvis using automatic exposure control (AEC) and non-AEC in a Computed Radiography (CR) system. Methods and materials - To determine the effects of using AEC and non-AEC by applying the 10 kVp rule in two experiments using an anthropomorphic pelvis phantom. Images were acquired using 10 kVp increments (60–120 kVp) for both experiments. The first experiment, based on seven AEC combinations, produced 49 images. The mean mAs from each kVp increment were used as a baseline for the second experiment producing 35 images. A total of 84 images were produced and a panel of 5 experienced observers participated for the image scoring using the two alternative forced choice (2AFC) visual grading software. PCXMC software was used to estimate E. Results - A decrease in perceptual image quality as the kVp increases was observed both in non-AEC and AEC experiments, however no significant statistical differences (p > 0.05) were found. Image quality scores from all observers at 10 kVp increments for all mAs values using non-AEC mode demonstrates a better score up to 90 kVp. E results show a statistically significant decrease (p = 0.000) on the 75th quartile from 0.37 mSv at 60 kVp to 0.13 mSv at 120 kVp when applying the 10 kVp rule in non-AEC mode. Conclusion - Using the 10 kVp rule, no significant reduction in perceptual image quality is observed when increasing kVp whilst a marked and significant E reduction is observed.