An advanced method for eliminating impacts from frequency deviations in power system signal processing

Frequency deviation is a common problem for power system signal processing. Many power system measurements are carried out in a fixed sampling rate assuming the system operates in its nominal frequency (50 or 60 Hz). However, the actual frequency may deviate from the normal value from time to time due to various reasons such as disturbances and subsequent system transients. Measurement of signals based on a fixed sampling rate may introduce errors under such situations. In order to achieve high precision signal measurement appropriate algorithms need to be employed to reduce the impact from frequency deviation in the power system data acquisition process. This paper proposes an advanced algorithm to enhance Fourier transform for power system signal processing. The algorithm is able to effectively correct frequency deviation under fixed sampling rate. Accurate measurement of power system signals is essential for the secure and reliable operation of power systems. The algorithm is readily applicable to such occasions where signal processing is affected by frequency deviation. Both mathematical proof and numerical simulation are given in this paper to illustrate robustness and effectiveness of the proposed algorithm. Crown Copyright (C) 2003 Published by Elsevier Science B.V. All rights reserved.

Sitting time and work patterns as indicators of overweight and obesity in Australian adults

BACKGROUND: Increasing levels of physical inactivity and sedentariness are contributing to the current overweight and obesity epidemic. In this paper, the findings of two recent studies are used to explore the relationships between sitting time ( in transport, work and leisure), physical activity and body mass index (BMI) in two contrasting samples of adult Australians. METHODS: Data on sitting time, physical activity, BMI and a number of demographic characteristics were compared for participants in two studies-529 women who were participants in a preschool health promotion project ('mothers'), and 185 men and women who were involved in a workplace pedometer study ('workers'). Relationships between age, number of children, physical activity, sitting time, BMI, gender and work patterns were explored. Logistic regression was used to predict the likelihood of being overweight or obese, among participants with different physical activity, sitting time and work patterns. RESULTS: The total reported time spent sitting per day ( across all domains) was almost 6 h less among the mothers than the workers (P

Optimising high-intensity treadmill training using the running speed at maximal O-2 uptake and the time for which this can be maintained

The aim of this study was to compare the effects of two high-intensity, treadmill interval-training programs on 3000-m and 5000-m running performance. Maximal oxygen uptake ((V) over dot O-2max), the running speed associated with (V) over dot O-2max (nu (V) over dot O-2max), the time for which nu (V) over dot O-2max can be maintained (T-max), running economy (RE), ventilatory threshold (VT) and 3000-m and 5000-m running times were determined in 27 well-trained runners. Subjects were then randomly assigned to three groups; (1) 60% T-max (2) 70% T-max and (3) control. Subjects in the control group continued their normal training and subjects in the two T-max groups undertook a 4-week treadmill interval-training program with the intensity set at nu (V) over dot O-2max and the interval duration at the assigned T-max. These subjects completed two interval-training sessions per week (60% T-max = six intervals/session, 70% T-max group = five intervals/session). Subjects were re-tested on all parameters at the completion of the training program. There was a significant improvement between pre- and post-training values in 3000-m time trial (TT) performance in the 60% T-max group compared to the 70% T,,a, and control groups [mean (SE); 60% T-max = 17.6 (3.5) s, 70% T-max = 6.3 (4.2) s, control = 0.5 (7.7) s]. There was no significant effect of the training program on 5000-m TT performance [60% T-max = 25.8 (13.8) s, 70% T-max = 3.7 (11.6) s, control = 9.9 (13.1) s]. Although there were no significant improvements in (V) over dot O-2max, nu (V) over dot (2max) and RE between groups, changes in (V) over dot O-2max and RE were significantly correlated with the improvement in the 3000-m TT. Furthermore, VT and T-max were significantly higher in the 60% Tmax group post-compared to pre-training. In conclusion, 3000-m running performance can be significantly improved in a group of well-trained runners, using a 4-week treadmill interval training program at nu (V) over dot O-2max with interval durations of 60% T-max.

The reliability of video based time motion analysis

Time motion analysis is extensively used to assess the demands of team sports. At present there is only limited information on the reliability of measurements using this analysis tool. The aim of this study was to establish the reliability of an individual observer's time motion analysis of rugby union. Ten elite level rugby players were individually tracked in Southern Hemisphere Super 12 matches using a digital video camera. The video footage was subsequently analysed by a single researcher on two occasions one month apart. The test-retest reliability was quantified as the typical error of measurement (TEM) and rated as either good (10% TEM). The total time spent in the individual movements of walking, jogging, striding, sprinting, static exertion and being stationary had moderate to poor reliability (5.8-11.1% TEM). The frequency of individual movements had good to poor reliability (4.3-13.6% TEM), while the mean duration of individual movements had moderate reliability (7.1-9.3% TEM). For the individual observer in the present investigation, time motion analysis was shown to be moderately reliable as an evaluation tool for examining the movement patterns of players in competitive rugby. These reliability values should be considered when assessing the movement patterns of rugby players within competition.

A comparison of two methods for the calculation of accumulated oxygen deficit

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a (V) over dotO(2peak) test and a 115% (V) over dotO(2peak) test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medbo et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P< 0.02) than that calculated from the second series: 52.3 +/- 11.7 and 43.9 +/- 6.4 ml . kg(-1), respectively (mean +/- s). Other significant differences between the two protocols were observed for (V) over dot O-2peak, total work and maximal heart rate; all were higher during the modified protocol (P

Differences in lung function, growth parameters and frequency of hospital admissions between adolescents with cystic fibrosis-related diabetes and controls

As survival of patients with CF increases,glucose intolerance and cystic fibrosisrelated diabetes (CFRD),ar e increasingly recognised common complications. CFRD may be preceded by a pre-diabetic state. Using markers identified as being associated with CFRD may improve targeted screening. Aim: To identify features consistently predicting CFRD in paediatric patients. Patients diagnosed with CFRD between January 1997–January 2002 were compared with age and sex matched controls. Clinical,micr obiological, and hospitalisation data was collected at time of CFRD diagnosis,and at six monthly intervals for 3 yr prior to diagnosis. Eight patients with CFRD were identified,mean age 13.7 yr (S.D. 3.49) at time of diagnosis. Control patients underwent OGTT to ensure normal glucose tolerance. Patients with CFRD had a lower FEV1 up to 12 months prior to diagnosis however, this was only significant at diagnosis. There was no difference in weight and height z scores between the 2 groups; however,the decrease in weight and height z scores in the CFRD group over 3 yr prior to diagnosis was significant. Mean number of days in hospital and admissions per patient significantly increased in the CFRD group,6 months prior to diagnosis. No other significant differences were observed between the 2 groups. Conclusions: This study has shown a difference in lung function,gr owth parameters and frequency of hospital admissions between patients with CFRD and controls. These differences may be utilised as tools for targeted screening in the paediatricyadolescent population. Further larger scale studies are required to improve guidelines for targeted screening in this population.

Coorte retrospectiva de crianças e adolescentes, infectados pelo HIV por transmissão vertical, no Espírito Santo : comorbidades, mortalidade e sobrevida

INTRODUÇÃO: O diagnóstico e terapia antirretroviral precoce em lactentes, infectados pelo HIV por transmissão vertical, reduz a progressão do HIV e comorbidades que podem levar ao óbito. OBJETIVO GERAL: Avaliar o perfil clínico e epidemiológico em uma coorte de crianças e adolescentes com aids, infectados por transmissão vertical do HIV, por um período de onze anos, atendidos em hospital estadual de referência, no Estado do Espírito Santo. OBJETIVOS ESPECÍFICOS: 1. Descrever a frequência das comorbidades diagnosticadas após o diagnóstico de HIV e verificar sua distribuição, segundo dados demográficos, epidemiológicos e clínicos, e segundo a classificação dos casos em uma coorte de crianças e adolescentes com aids. 2. Avaliar os fatores preditores de risco de progressão para aids e óbito e causas de morte. 3. Estimar a taxa de sobrevida. MÉTODOS: Coorte retrospectiva de crianças e adolescentes infectados pelo HIV, por transmissão vertical (TV), atendidas no Serviço de Atendimento Especializado (SAE) do Hospital Infantil Nossa Senhora da Glória (HINSG), de janeiro 2001 a dezembro 2011, em Vitória – ES/Brasil. A coleta de dados foi realizada em protocolo específico padronizado, e dados sobre as comorbidades, mortalidade e sua causa básica foram obtidos dos prontuários médicos, da Declaração de Óbito e do banco de dados SIM (Sistema de Informação sobre Mortalidade). O diagnóstico de aids e comorbidades foi de acordo com CDC (Centers for Disease Control and Prevention)/1994. RESULTADOS: Foi arrolado um total de 177 pacientes, sendo 97 (55%) do sexo feminino; 60 (34%) eram menores de1ano, 67 (38%) tinham de 1 a 5 anos e 50 (28%) tinham6 anos ou mais de idade no ingresso ao serviço. A mediana das idades na admissão foi de 30 meses (Intervalo Interquartis (IIQ) 25-75%: 5-72 meses). Em relação à classificação clínico-imunológica, 146 pacientes (82,5%) apresentavam a forma moderada/grave no momento do ingresso no Serviço e 26 (14,7%) foram a óbito. Os sinais clínicos mais frequentes foram hepatomegalia (81,62%), esplenomegalia (63,8%), linfadenopatia (68,4%) e febre persistente (32,8%). As comorbidades mais frequentes foram anemia (67,2%), pneumonia/sepses/meningite - primeiro episódio (64,2%), OMA/sinusite recorrente (55,4%), infecções bacterianas graves recorrentes (47,4%) e dermatites (43,1%). Encontrou-se associação entre classificação clínico-imunológica grave e ingresso no serviço com menos de um ano de idade com algumas comorbidades (p<0,001). O tempo total do acompanhamento dos pacientes foi de 11 anos, com mediana de cinco anos (IIQ: 2-8 anos). No final do período estudado, 132 (74,6%) pacientes estavam em acompanhamento, 11 (6,2%) foram transferidos para outros serviços eem oito (4,5%) houve perda de seguimento. Quanto ao óbito, observou-se uma redução de casos ao longo do tempo. A maioria dos pacientes que foram a óbito deu entrada no serviço com classificação clínica imunológica grave (77%-20/26), apresentava anemia moderada/grave e estava em uso de terapia antirretroviral (TARV) por mais de 3 meses (17/24-71%).Os principais fatores de risco para o óbito foram: faixa etária < 1 ano (p=0,005), pneumonia por P. jirovecii (p=0,010), percentual de linfócito T CD4+ nadir <15% (p=0,012), anemia crônica (p=0,012), estágio clínico imunológico grave (p=0,003), infecções bacterianas graves recorrentes(p=0,003) e tuberculose (p=0,037). Ter iniciado TARV antes dos 6 meses de vida (diagnóstico e tratamento precoces) foi associado à sobrevida(OR 2,86, [Intervalo de Confiança (IC) de 95%: 1,12-7,25] p=0,027).O principal diagnóstico registrado para os óbitos foram infecções bacterianas graves (12/21-57%). Foi encontrada uma elevada taxa de sobrevida, com 85,3% de probabilidade de sobrevivência por mais de 10 anos (IC 95% 9,6-10,7). CONCLUSÕES: A maioria das crianças teve diagnóstico tardio da infecção pelo HIV aumentando o risco de progressão para aids e óbito por falta de tratamento precoce. A tendência de mortalidade das crianças infectadas pelo HIV se mostrou uma constante com queda nos dois últimos anos do estudo, e ainda persistem as infecções bacterianas como maior causa de óbito. Portanto, melhoria no cuidado pré-natal e acompanhamento pediátrico com vista ao diagnóstico precoce das crianças infectadas verticalmente devem fazer parte do cuidado integral à criança com aids, o que poderia reduzir a mortalidade destas crianças.

Eventos de vida em mulheres com diagnóstico de câncer de mama

Introdução: A relação entre eventos de vida e o surgimento e progressão do câncer de mama tem sido investigada por alguns estudos. Objetivo: Identificar os eventos de vida ocorridos em mulheres com diagnóstico de câncer de mama, examinar o tempo transcorrido entre o evento e o diagnóstico, examinar a associação entre a sobrecarga ocasionada pelo evento no momento da ocorrência e após o diagnóstico e examinar a associação entre metástase e eventos de vida pós diagnóstico de câncer de mama. Metodologia: Estudo transversal realizado no Hospital Santa Rita de Cássia, Vitória – ES. Compõe-se a amostra por 300 mulheres. Coletaram-se os dados no período de setembro a dezembro de 2014. Utilizou-se o instrumento Life Events Units – LEU/VAS que se baseia na Escala de Avaliação de Reajustamento Social de Holmes e Rahe, que no Brasil foi adaptada por Vasconcellos. Utilizou-se o Pacote Estatístico para Ciências Sociais (SPSS), versão 20.0, para calcular a frequência, média, mediana, desvio padrão e aplicar os testes não paramétrico de Wilcoxon e qui-quadrado. Resultados: A média de idade foi de 53 anos. Predominou-se mulheres de raça/cor não branca (65%), com menos de 8 anos de estudo (64%) e casadas (54%). Identificou-se que a maioria da amostra relatou pelo menos um evento de vida (99,3%). O principal evento de vida relatado foi morte de alguém na família. As medianas do tempo transcorrido entre os eventos de vida mais relatados e o diagnóstico de câncer de mama variaram de 5 a 15 anos. Observou-se diferença significante (p< 0,05) entre a sobrecarga ocasionada pelos eventos de vida nos dois momentos examinados. Em relação à metástase, 31,7% das que tiveram recidivas relataram um ou mais eventos de vida (p= 0,001). Quando considerado o tempo transcorrido entre o diagnóstico e o surgimento da metástase nas 46 mulheres, observou-se uma mediana de 18,0 meses. Conclusão: Os resultados deste estudo são potencialmente importantes, pois dão suporte a uma possível interação entre eventos de vida pós diagnóstico de câncer de mama e metástase. Estudos futuros são necessários para melhor compreensão desta relação.

Collecting system percutaneous access using real-time tracking sensors: first pig model in vivo experience

Purpose: Precise needle puncture of the renal collecting system is an essential but challenging step for successful percutaneous nephrolithotomy. We evaluated the efficiency of a new real-time electromagnetic tracking system for in vivo kidney puncture. Materials and Methods: Six anesthetized female pigs underwent ureterorenoscopy to place a catheter with an electromagnetic tracking sensor into the desired puncture site and ascertain puncture success. A tracked needle with a similar electromagnetic tracking sensor was subsequently navigated into the sensor in the catheter. Four punctures were performed by each of 2 surgeons in each pig, including 1 each in the kidney, middle ureter, and right and left sides. Outcome measurements were the number of attempts and the time needed to evaluate the virtual trajectory and perform percutaneous puncture. Results: A total of 24 punctures were easily performed without complication. Surgeons required more time to evaluate the trajectory during ureteral than kidney puncture (median 15 seconds, range 14 to 18 vs 13, range 11 to 16, p ¼ 0.1). Median renal and ureteral puncture time was 19 (range 14 to 45) and 51 seconds (range 45 to 67), respectively (p ¼ 0.003). Two attempts were needed to achieve a successful ureteral puncture. The technique requires the presence of a renal stone for testing. Conclusions: The proposed electromagnetic tracking solution for renal collecting system puncture proved to be highly accurate, simple and quick. This method might represent a paradigm shift in percutaneous kidney access techniques

Collecting system percutaneous access using real-time tracking sensors: first pig model in vivo experience

Purpose: Precise needle puncture of the renal collecting system is an essential but challenging step for successful percutaneous nephrolithotomy. We evaluated the efficiency of a new real-time electromagnetic tracking system for in vivo kidney puncture. Materials and Methods: Six anesthetized female pigs underwent ureterorenoscopy to place a catheter with an electromagnetic tracking sensor into the desired puncture site and ascertain puncture success. A tracked needle with a similar electromagnetic tracking sensor was subsequently navigated into the sensor in the catheter. Four punctures were performed by each of 2 surgeons in each pig, including 1 each in the kidney, middle ureter, and right and left sides. Outcome measurements were the number of attempts and the time needed to evaluate the virtual trajectory and perform percutaneous puncture. Results: A total of 24 punctures were easily performed without complication. Surgeons required more time to evaluate the trajectory during ureteral than kidney puncture (median 15 seconds, range 14 to 18 vs 13, range 11 to 16, p ¼ 0.1). Median renal and ureteral puncture time was 19 (range 14 to 45) and 51 seconds (range 45 to 67), respectively (p ¼ 0.003). Two attempts were needed to achieve a successful ureteral puncture. The technique requires the presence of a renal stone for testing. Conclusions: The proposed electromagnetic tracking solution for renal collecting system puncture proved to be highly accurate, simple and quick. This method might represent a paradigm shift in percutaneous kidney access techniques.

Preliminary clinical trial in percutaneous nephrolithotomy using a real-time navigation system for percutaneous kidney access

Background: Precise needle puncture of renal calyces is a challenging and essential step for successful percutaneous nephrolithotomy. This work tests and evaluates, through a clinical trial, a real-time navigation system to plan and guide percutaneous kidney puncture. Methods: A novel system, entitled i3DPuncture, was developed to aid surgeons in establishing the desired puncture site and the best virtual puncture trajectory, by gathering and processing data from a tracked needle with optical passive markers. In order to navigate and superimpose the needle to a preoperative volume, the patient, 3D image data and tracker system were previously registered intraoperatively using seven points that were strategically chosen based on rigid bone structures and nearby kidney area. In addition, relevant anatomical structures for surgical navigation were automatically segmented using a multi-organ segmentation algorithm that clusters volumes based on statistical properties and minimum description length criterion. For each cluster, a rendering transfer function enhanced the visualization of different organs and surrounding tissues. Results: One puncture attempt was sufficient to achieve a successful kidney puncture. The puncture took 265 seconds, and 32 seconds were necessary to plan the puncture trajectory. The virtual puncture path was followed correctively until the needle tip reached the desired kidney calyceal. Conclusions: This new solution provided spatial information regarding the needle inside the body and the possibility to visualize surrounding organs. It may offer a promising and innovative solution for percutaneous punctures.

Real-time hand tracking for rehabilitation and character animation

Hand and finger tracking has a major importance in healthcare, for rehabilitation of hand function required due to a neurological disorder, and in virtual environment applications, like characters animation for on-line games or movies. Current solutions consist mostly of motion tracking gloves with embedded resistive bend sensors that most often suffer from signal drift, sensor saturation, sensor displacement and complex calibration procedures. More advanced solutions provide better tracking stability, but at the expense of a higher cost. The proposed solution aims to provide the required precision, stability and feasibility through the combination of eleven inertial measurements units (IMUs). Each unit captures the spatial orientation of the attached body. To fully capture the hand movement, each finger encompasses two units (at the proximal and distal phalanges), plus one unit at the back of the hand. The proposed glove was validated in two distinct steps: a) evaluation of the sensors’ accuracy and stability over time; b) evaluation of the bending trajectories during usual finger flexion tasks based on the intra-class correlation coefficient (ICC). Results revealed that the glove was sensitive mainly to magnetic field distortions and sensors tuning. The inclusion of a hard and soft iron correction algorithm and accelerometer and gyro drift and temperature compensation methods provided increased stability and precision. Finger trajectories evaluation yielded high ICC values with an overall reliability within application’s satisfying limits. The developed low cost system provides a straightforward calibration and usability, qualifying the device for hand and finger tracking in healthcare and animation industries.

A-scan ultrasound system for real-time puncture safety assessment during percutaneous nephrolithotomy

Background: Kidney stone is a major universal health problem, affecting 10% of the population worldwide. Percutaneous nephrolithotomy is a first-line and established procedure for disintegration and removal of renal stones. Its surgical success depends on the precise needle puncture of renal calyces, which remains the most challenging task for surgeons. This work describes and tests a new ultrasound based system to alert the surgeon when undesirable anatomical structures are in between the puncture path defined through a tracked needle. Methods: Two circular ultrasound transducers were built with a single 3.3-MHz piezoelectric ceramic PZT SN8, 25.4 mm of radius and resin-epoxy matching and backing layers. One matching layer was designed with a concave curvature to work as an acoustic lens with long focusing. The A-scan signals were filtered and processed to automatically detect reflected echoes. Results: The transducers were mapped in water tank and tested in a study involving 45 phantoms. Each phantom mimics different needle insertion trajectories with a percutaneous path length between 80 and 150 mm. Results showed that the beam cross-sectional area oscillates around the ceramics radius and it was possible to automatically detect echo signals in phantoms with length higher than 80 mm. Conclusions: This new solution may alert the surgeon about anatomical tissues changes during needle insertion, which may decrease the need of X-Ray radiation exposure and ultrasound image evaluation during percutaneous puncture.

Evaluation of the influence of the ADH3 ILE349VAL polymorphism in the frequency of genotoxicity biomarkers in workers exposed to formaldehyde and tobacco smoking

Formaldehyde (FA) is a colourless gas widely used in the industry and hospitals as an aqueous solution, formalin. It is extremely reactive and induces various genotoxic effects in proliferating cultured mammalian cells. Tobacco smoke has been epidemiologically associated to a higher risk of development of cancer, especially in the oral cavity, larynx and lungs, as these are places of direct contact with many carcinogenic tobacco’s compounds. Genetic polymorphisms in enzymes involved in the metabolism are very important and can make changes in the individual susceptibility to disease. Alcohol dehydrogenase class 3 (ADH3), also known as formaldehyde dehydrogenase dependent of glutathione, is the major enzyme involved in the formaldehyde oxidation, especially in the buccal mucosa. The polymorphism in study is a substitution of an isoleucine for a valine in codon 349. The cytokinesis-blocked micronucleus assay (CBMN) in human lymphocytes is one of the most commonly used methods for measuring DNA damage, namely the detection of micronucleus, nucleoplasmic bridges, and nuclear buds, classified as genotoxicity biomarkers.

Accessing Planktothrix species diversity and associated toxins using quantitative real-time PCR in natural waters

Tese de Doutoramento em Biologia apresentada à Faculdade de Ciências da Universidade do Porto, 2015.