561 |
Predicted versus actual psycho-socio-economic impacts of mining and infrastructure projectsLotter, Karien 06 July 2013 (has links)
In this study, the accuracy of predicted psycho-socio-economic impacts resulting from mining and infrastructure projects is investigated by comparing it to impacts shown to actually occur. A systems theoretical approach was followed in conjunction with a qualitative methodology in order to conceptualise impacts in the social systems they occur. Data was collected through a document review (which included a total of 17 documents pertaining to predicted impacts, and 24 documents pertaining to actual impacts) and analysed by means of thematic analysis, which rendered four main themes and 20 subthemes. The findings of the thematic analysis were subjected to second-order analysis, which enabled the categorisation of impacts according to the level of accuracy with which they are predicted. To understand why some impacts are incorrectly predicted, a third-order analysis was performed. The study suggests that many of the commonly predicted psycho-socio-economic impacts are less accurate than what they should ideally be, suggesting that some of the assumptions on which these predictions are based should be revised, as should the conceptualisation of the impacts. The researcher argues that, in order to make accurate predictions about the impacts resulting from mining and infrastructure projects, sufficient knowledge of the attributes of the project, the nature of the receiving environment, the causal processes by which the project will bring about changes in the receiving environment, and the value systems according to which communities judge whether a specific change constitutes a negative or positive impact, is required. This argument is substantiated by highlighting instances of inaccurate predictions relevant to each category of required information. More fundamentally, however, the researcher argues that inaccurate predictions are the result of inadequate consideration of the systemic nature of psycho-socio-economic impacts and the context in which they occur, precipitated by the incorrect use of the “social impact” metaphor. / Dissertation (MA)--University of Pretoria, 2013. / Psychology / unrestricted
|
562 |
Diagnosing DVT in the Emergency Department: Combining Clinical Predictors, D-dimer and Bedside UltrasoundBlecher, Gabriel E. January 2013 (has links)
I assessed the accuracy of two clinical prediction rules, the d-dimer blood test and point of care ultrasound for diagnosing lower limb deep vein thrombosis.
Emergency physicians were trained in ultrasound and prospectively scanned emergency department patients with suspected deep vein thrombosis. Accuracy of the Wells and AMUSE rules and the ultrasound result was compared to radiology-performed ultrasound and a 90-day clinical outcome. Univariate and multivariate analyses were performed assessing which factors were associated with the outcome.
The sensitivity and specificity of the Wells score for the clinical outcome was 85.7% and 68.5%; the AMUSE score 85.7% and 54.4%. Ultrasound had a sensitivity of 91.7% and specificity of 91.7% for radiology-diagnosed thrombus and 78.6% and 95.0% for clinical outcome. The odds ratio of a positive outcome with a positive ultrasound was 65.1.
After receiving the ultrasound training program, emergency physicians were unable to demonstrate sufficient accuracy to replace current diagnostic strategies.
|
563 |
3D Sensing and Tracking of Human GaitYang, Lin January 2015 (has links)
Motion capture technology has been applied in many fields such as animation, medicine, military, etc. since it was first proposed in the 1970s. Based on the principles applied, motion capture technology is generally classified into six categories: 1) Optical; 2) Inertial; 3) Magnetic; 4) Mechanical; 5) Acoustic and 6) Markerless. Different from the other five kinds of motion capture technologies which try to track path of specific points with different equipment, markerless systems recognize human or non-human body's motion with vision-based technology which focuses on analyzing and processing the captured images for motion capture. The user doed not need to wear any equipment and is free to do any action in an extensible measurement area while a markerless motion capture system is working. Though this kind of system is considered as the preferred solution for motion capture, the difficulty for realizing an effective and high accuracy markerless system is much higher than the other technologies mentioned, which makes markerless motion capture development a popular research direction. Microsoft Kinect sensor has attracted lots of attention since the launch of its first version with its depth sensing feature which gives the sensor the ability to do motion capture without any extra devices. Recently, Microsoft released a new version of Kinect sensor with improved hardware and and targeted at the consumer market. However, to the best of our knowlege, the accuracy assessment of the sensor remains to be answered since it was released. In this thesis, we measure the depth accuracy of the newly released Kinect v2 depth sensor from different aspects and propose a trilateration method to improve the depth accuracy with multiple Kinects simultaneously. Based on the trilateration method, a low-cost, no wearable equipment requirement and easy setup human gait tracking system is realized.
|
564 |
Robust, refined and selective matching for accurate camera pose estimation / Sélection et raffinement de mises en correspondance robustes pour l'estimation de pose précise de camérasLiu, Zhe 13 April 2015 (has links)
Grâce aux progrès récents en photogrammétrie, il est désormais possible de reconstruire automatiquement un modèle d'une scène 3D à partir de photographies ou d'une vidéo. La reconstruction est réalisée en plusieurs étapes. Tout d'abord, on détecte des traits saillants (features) dans chaque image, souvent des points mais plus généralement des régions. Puis on cherche à les mettre en correspondance entre images. On utilise ensuite les traits communs à deux images pour déterminer la pose (positions et orientations) relative des images. Puis les poses sont mises dans un même repère global et la position des traits saillants dans l'espace est reconstruite (structure from motion). Enfin, un modèle 3D dense de la scène peut être estimé. La détection de traits saillants, leur appariement, ainsi que l'estimation de la position des caméras, jouent des rôles primordiaux dans la chaîne de reconstruction 3D. Des imprécisions ou des erreurs dans ces étapes ont un impact majeur sur la précision et la robustesse de la reconstruction de la scène entière. Dans cette thèse, nous nous intéressons à l'amélioration des méthodes pour établir la correspondance entre régions caractéristiques et pour les sélectionner lors de l'estimation des poses de caméras, afin de rendre les résultats de reconstruction plus robustes et plus précis. Nous introduisons tout d'abord une contrainte photométrique pour une paire de correspondances (VLD) au sein d'une même image, qui est plus fiable que les contraintes purement géométriques. Puis, nous proposons une méthode semi-locale (K-VLD) pour la mise en correspondance, basée sur cette contrainte photométrique. Nous démontrons que notre méthode est très robuste pour des scènes rigides, mais aussi non-rigides ou répétitives, et qu'elle permet d'améliorer la robustesse et la précision de méthodes d'estimation de poses, notamment basées sur RANSAC. Puis, pour améliorer l'estimation de la position des caméras, nous analysons la précision des reconstructions et des estimations de pose en fonction du nombre et de la qualité des correspondances. Nous en dérivons une formule expérimentale caractérisant la relation ``qualité contre quantité''. Sur cette base, nous proposons une méthode pour sélectionner un sous-ensemble des correspondances de meilleure qualité de façon à obtenir une très haute précision en estimation de poses. Nous cherchons aussi raffiner la précision de localisation des points en correspondance. Pour cela, nous développons une extension de la méthode de mise en correspondance aux moindres carrés (LSM) en introduisant un échantillonnage irrégulier et une exploration des échelles d'images. Nous montrons que le raffinement et la sélection de correspondances agissent indépendamment pour améliorer la reconstruction. Combinées, les deux méthodes produisent des résultats encore meilleurs / With the recent progress in photogrammetry, it is now possible to automatically reconstruct a model of a 3D scene from pictures or videos. The model is reconstructed in several stages. First, salient features (often points, but more generally regions) are detected in each image. Second, features that are common in images pairs are matched. Third, matched features are used to estimate the relative pose (position and orientation) of images. The global poses are then computed as well as the 3D location of these features (structure from motion). Finally, a dense 3D model can be estimated. The detection of salient features, their matching, as well as the estimation of camera poses play a crucial role in the reconstruction process. Inaccuracies or errors in these stages have a major impact on the accuracy and robustness of reconstruction for the entire scene. In this thesis, we propose better methods for feature matching and feature selection, which improve the robustness and accuracy of existing methods for camera position estimation. We first introduce a photometric pairwise constraint for feature matches (VLD), which is more reliable than geometric constraints. Then we propose a semi-local matching approach (K-VLD) using this photometric match constraint. We show that our method is very robust, not only for rigid scenes but also for non-rigid and repetitive scenes, which can improve the robustness and accuracy of pose estimation methods, such as based on RANSAC. To improve the accuracy in camera position estimation, we study the accuracy of reconstruction and pose estimation in function of the number and quality of matches. We experimentally derive a “quantity vs. quality” relation. Using this relation, we propose a method to select a subset of good matches to produce highly accurate pose estimations. We also aim at refining match position. For this, we propose an improvement of least square matching (LSM) using an irregular sampling grid and image scale exploration. We show that match refinement and match selection independently improve the reconstruction results, and when combined together, the results are further improved
|
565 |
Improving Seed Spacing Uniformity of Precision Vegetable PlantersSiemens, M.C., Gayler, R.R. January 2016 (has links)
Equidistant, uniform seed placement is important in lettuce production as seeds are densely planted within the row, typically only about 5 cm apart. When seeds are sown too close together, it is time consuming to thin seedlings to the desired plant spacing of 20 to 30 cm by hand and very difficult to do mechanically. The overall goal of the project was to improve lettuce seed placement accuracy and reduce the percentage of seeds spaced closely together. Specific objectives were: 1) to compare vacuum and belt-type planters to determine which style of planter provides better planting performance, 2) to evaluate belt planter seeding performance with different types of furrow openers, and 3) to develop practical modifications for vacuum planters to improve lettuce seed placement accuracy. Three vacuum planter configurations, an unmodified and two reduced seed drop height designs and a belt planter equipped with two types of furrow openers were tested in situ with pelleted lettuce seed at four travel speeds ranging from 1.6 to 4.0 kph. Belt planter performance was significantly better than that of the vacuum planter. Vacuum and belt planters both provided acceptable levels of performance at speeds below 2.4 kph, but at higher speeds, seed placement accuracy declined rapidly. No differences in planter performance were found between the two belt planter configurations tested. The mid-level drop height vacuum planter configuration had significantly better seed placement precision and fewer closely spaced seed spacings as compared to the unmodified vacuum planter. These findings illustrate the significant effect planter type, travel speed, and drop height have on planter performance. They also contradict the common perception that vacuum planters deliver seed more precisely and with fewer closely-spaced seeds as compared to belt planters. Further study is needed to determine the extent to which planter performance affects hand thinning labor costs, automated machine performance, final plant stand uniformity, and crop yield.
|
566 |
Mensuração da alteração dimensional de uma silicona por condensação através de três métodos distintos / The dimensional change measurement of a silicone condensation trhough three different methodsCunha, Thaiana Damaceno 27 April 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-04T14:43:43Z
No. of bitstreams: 1
thaianadamacenocunha.pdf: 1265962 bytes, checksum: 6d8fb90304d78d671faf48a4a00e64e5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2015-12-07T03:22:42Z (GMT) No. of bitstreams: 1
thaianadamacenocunha.pdf: 1265962 bytes, checksum: 6d8fb90304d78d671faf48a4a00e64e5 (MD5) / Made available in DSpace on 2015-12-07T03:22:42Z (GMT). No. of bitstreams: 1
thaianadamacenocunha.pdf: 1265962 bytes, checksum: 6d8fb90304d78d671faf48a4a00e64e5 (MD5)
Previous issue date: 2015-04-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo deste estudo foi mensurar a alteração dimensional de uma silicona por condensação através de um paquímetro digital (Mitutuyo), de um estéreo microscópio (Olympus) e de uma máquina de medição tridimensional por coordenadas (Mitutuyo). Foram realizadas 4 moldagens através de um dispositivo específico com a silicona por condensação pesada e leve Speedex (Coltene/Vigodent). Em cada um dos 4 moldes 4 distâncias foram mensuradas pelos 3 instrumentos, em 4 tempos distintos: no momento da remoção do molde e após 30min, 1h e 7 dias. As médias das mensurações foram submetidas ao teste estatístico Kruskal-Wallis com nível de significância de 5%. Os resultados mostraram diferenças significantes entre as alterações dimensionais verificadas por cada um dos instrumentos de medição, as mensurações realizadas pelo paquímetro digital e pela máquina de medição tridimensional por coordenadas apresentaram alterações dimensionais significantes nos 4 tempos testados, enquanto as pelo estéreo microscópio não apresentaram diferença significante nos 4 tempos. Concluiu-se que as alterações dimensionais verificadas nos moldes da silicona por condensação testada obtidas através de cada instrumento de medição utilizado nesta pesquisa foram diferentes entre si, evidenciando que os diferentes métodos de medição utilizados podem fornecer resultados distintos, e consequentemente, indicações equivocadas. / The aim of this study was to measure the dimensional changes of a silicone condensation using a digital paquimeter (Mitutuyo), an estereomicroscope (Olympus) and a three-dimensional coordinate measuring machine (Mitutuyo). Were made 4 impressions trhough a specif device using the putty and light silicone condensation Speedex (Coltene/Vigodent). Four distances were measured at each impression through the 3 instruments at 4 different times: in the moment of removal of the die and after 30min, 1h e 7 days. The avarage of the measurements were subimitted to the statistical test Kruskal-Wallis with level of significance of 5%. The results shows significant diferences between the dimensional changes verified by each one of the measuring instruments, the measurements through the digital paquimeter and the measurements trhough the three-dimensional coordinate measuring machine showed significant dimensional changes in the 4 tested times, while the measurements through the estereomicroscope did not show significant difference in the 4 tested times. It concludes that the dimensional changes verified in the tested silicone condensation by each measurement instrument used in this study were diferente, indicating that the different measuring methods used can provide wrong results, and consequently, wrong indications.
|
567 |
Coordenação postural em adultos e idosos durante movimentos voluntários na postura ereta / Postural coordination in adults and elderly individuals during voluntary whole-body movementsSandra Maria Sbeghen Ferreira de Freitas 05 July 2005 (has links)
Este estudo investigou como padrões de coordenação postural durante movimentos voluntários do corpo todo durante a postura ereta são afetados pelo envelhencimento usando o paradigma da relação entre velocidade e acurácia. Dez idosos e dez adultos jovens permaneceram em pé sobre uma plataforma de força e tiveram a posição instantânea do centro de pressão (CP) mostrada como feedback visual em um monitor a um metro a frente. Os participantes executaram movimentos contínuos rápidos e acurados na direção ântero-posterior com o corpo todo movendo a posição do CP entre alvos de diferentes larguras ou em diferentes freqüências de movimento, durante 45 s. Tempo de movimento (TM), deslocamento do CP, excursão dos ângulos articulares e atividade eletromiográfica (EMG) dos músculos do tornozelo, joelho e quadril foram analisados. Análises de componentes principais (PC) dos ângulos articulares foram também efetuadas. Flexibilidade da coordenação postural foi avaliada usando a abordagem da variedade não controlada (UCM) para testar as hipóteses de estabilização do tronco e do centro de massa (CM). Ambos grupos aumentaram o TM, atividade EMG e variáveis cinemáticas com um aumento na acurácia e freqüência. Sujeitos idosos aumentaram a amplitude dos ângulos articulares e EMG comparados aos adultos. Análise de PC mostrou alto acoplamento entre as articulações e a análise do UCM confirmou as hipóteses de estabilização do tronco e do CM. Os resultados indicam que padrões de coordenação postural são afetados pela acurácia dos movimentos do corpo todo e algumas dessas alterações estão relacionadas ao envelhecimento / This study examined how postural coodination patterns during voluntary whole-body movements in standing are affected by aging using the speed-accuracy trade-off paradigm. Ten elderly subjects and ten young adults stood on a force plate and had their center of pressure (COP) instantaneous position shown as visual feedback on a computer monitor one meter ahead. The participants performed continuous fast and accurate movements in the anterior-posterior direction with the whole body shifting their COP position; between targets with different widths or in different movement frequencies, during 45 s. Movement time (MT), COP displacement, joint angle excursion and eletromyographic (EMG) activity of ankle, knee and hip muscles were analyzed. Principal component (PC) analyses of the joint angles were also carried out. Flexibility of the postural coordination was evaluated using uncontrolled manifold (UCM) approach to test the trunk and the center of mass (COM) stabilization hypothesis. Both groups increased the MT, EMG activity and kinematic variables with an increase in the accuracy and frequency. Elderly subjects increased joint angles and EMG amplitude compared to adults. PC analysis showed a high coupling among the joints and the UCM analysis confirmed the trunk and the COM stabilization hypothesis. The results indicated that postural coordination patterns are affected by accuracy of whole-body movements and some changes are correlated with to aging
|
568 |
Integração do controle postural e de ações manuais em função da previsibilidade de perturbação e da demanda de precisão espacial / Integration between postural control and manual tasks as a function of predictability of perturbation and spatial precision demandElke dos Santos Lima 01 April 2008 (has links)
O objetivo deste estudo foi analisar o controle postural diante da previsibilidade da carga elevada através de ação manual e da demanda atencional promovida pelo acréscimo de um alvo espacial na tarefa. Quinze sujeitos do sexo masculino (idade média 22,8+3,5 anos) realizaram a tarefa de elevação de uma caixa por meio da preensão manual, com massa variável (1, 3 e 5kg) nas condições previsível ou imprevisível. A tarefa também era executada em uma condição de maior demanda atencional promovida pela colocação de um alvo frontal, que deveria ser atingido por um facho de luz laser, cuja fonte estava fixada na caixa elevada pelo sujeito. Foram analisados o comportamento do centro de pressão (CP) e a cinemática das principais articulações e do movimento da caixa. Os resultados indicaram que a imprevisibilidade sobre a massa da caixa aumentou a oscilação do CP. Aumento da oscilação do CP também foi observado na situação de redução de massa, mesmo quando os sujeitos tinham conhecimento da mudança. A situação de pontaria em alvo induziu redução (a) do deslocamento do CP, (b) velocidade de elevação da caixa, e (c) amplitude de movimento do tornozelo e quadril. Estes resultados indicam que a previsibilidade sobre a ação de forças externas no corpo, demanda espacial da tarefa manual, e organização/feedback do movimento da tentativa anterior interagem para afetar o controle postural / The aim of this study was to analyze postural control as a function of predictability of a load lifted with the hands, and demand of spatial accuracy in the task. Fifteen males (mean age: 22.8 3.5 years) lifted boxes with variable masses (1, 3 and 5 kg), in conditions of predictable or unpredictable load. The task was performed either under lower spatial accuracy demand or aiming at a spatial target. Displacement of center of pressure (CP) and kinematics of the main joints/box motion were analyzed to access postural perturbation induced by the lifting task. Results showed that unpredictability about mass of the box enhanced CP displacement. Enhanced CP displacement was also observed in situations of decreased mass regarding the previous trial, even when participants were aware about the change. The pointing task induced decreased (a) CP displacement, (b) box lifting velocity, and (c) ankle and hip motion amplitude. These results indicate that predictability about external forces acting on the body, spatial demand of manual tasks, and movement organization/feedback of the previous trial interact to affect postural control
|
569 |
Impacto da reflexão estruturada na calibragem diagnóstica de alunos do 6º ano do curso de medicina da Unifenas BHCosta Filho, Galileu Bonifácio da 16 December 2017 (has links)
Submitted by Kely Alves (kely.alves@unifenas.br) on 2018-08-01T11:51:08Z
No. of bitstreams: 1
Dissertação Galileu Bonifácio.pdf: 1876947 bytes, checksum: 040bde4c33a32b1025e2822176ae0797 (MD5) / Approved for entry into archive by Kely Alves (kely.alves@unifenas.br) on 2018-08-01T11:52:29Z (GMT) No. of bitstreams: 1
Dissertação Galileu Bonifácio.pdf: 1876947 bytes, checksum: 040bde4c33a32b1025e2822176ae0797 (MD5) / Approved for entry into archive by Kely Alves (kely.alves@unifenas.br) on 2018-08-01T11:53:21Z (GMT) No. of bitstreams: 1
Dissertação Galileu Bonifácio.pdf: 1876947 bytes, checksum: 040bde4c33a32b1025e2822176ae0797 (MD5) / Made available in DSpace on 2018-08-01T11:53:40Z (GMT). No. of bitstreams: 1
Dissertação Galileu Bonifácio.pdf: 1876947 bytes, checksum: 040bde4c33a32b1025e2822176ae0797 (MD5)
Previous issue date: 2017-12-16 / Introduction: Diagnostic calibration can be defined as the relationship between diagnostic accuracy and the confidence in that accuracy. Reflective practice seems to be an interesting strategy to improve diagnostic calibration by improving performance insights and has been proposed to foster clinical reasoning by improving diagnostic accuracy. However, its effect on diagnostic calibration has yet to be assessed. Aim: This study seeks to evaluate the impact of structured reflection on diagnostic calibration, diagnostic accuracy, and the confidence in that accuracy while solving dermatology case vignettes. Methods: This study recruited sixth year medical students from Universidad José do Rosário Vellano, who were systematically allocated into one of two groups: reflection group (RG) or control group (CG). Students from both groups were presented the same 12 dermatology cases and were initially asked to point out the probable diagnosis and their confidence in that diagnosis. The students allocated to the RG were then told to reflect on the case using a structured tool. Those allocated to the CG engaged in a time-filler activity before providing their final diagnosis for each case and their final confidence in that diagnosis. Both groups were compared as to their diagnostic accuracy, confidence, and diagnostic calibration overall as well as stratified by dermatological syndrome and case difficulty. Results: Sixty-one students were included (33 in the RG and 28 in the CG). Age and self-assessed perception of knowledge/previous experience were similar in both groups. Gender was significantly different among the groups. Students from the RG showed a better diagnostic accuracy for both melanocytic and non-melanocytic lesions (p=0.025 and p=0.022, respectively). Regarding diagnostic calibration, both RG and CG showed better calibration for melanocytic lesions than for non-melanocytic lesions. Calibration for non-melanocytic lesions was more distant from zero, in a positive direction (i.e. greater overconfidence). It was observed that calibration was worse among more difficult cases, with students showing greater overconfidence when solving such cases. Reflection did not impact significantly on confidence nor on calibration (p=0.228 and p=0.197, respectively). It is worth noting that a significant difference was observed in the calibration in both groups when solving easier cases; students from the RG had a greater diagnostic accuracy, but their confidence did not differ from those in the CG, resulting in an opposite direction of calibration (i.e. among students in the RG, diagnostic accuracy was slightly greater than their confidence). Conclusion: Reflective practice increased the overall diagnostic accuracy, but it did not significantly change overall confidence and calibration. Calibration was worse when solving more difficult cases, and reflection was not enough to improve it. / Introdução: A calibragem diagnóstica pode ser definida como a relação entre acurácia e confiança do profissional em relação a esta acurácia. A prática reflexiva é uma potencial estratégia para melhorar a calibragem diagnóstica, pois pode aumentar o insight sobre a performance. O uso da reflexão estruturada para melhoria da calibragem diagnóstica ainda não foi avaliado. Objetivo: Avaliar o impacto da reflexão estruturada na calibragem diagnóstica, acurácia e confiança na resolução de casos dermatológicos. Métodos: estudo realizado entre alunos do 6º ano do curso de medicina da universidade José do Rosário Vellano (UNIFENAS-BH). Os alunos foram divididos em dois grupos (grupo reflexão (GR) e grupo controle (GC)). Os dois grupos avaliaram as mesmas 12 lesões dermatológicas, apontando diagnóstico inicial mais provável e a confiança diagnóstica. Em seguida, os alunos foram orientados a refletirem de maneira estruturada sobre o diagnóstico (GR) ou engajarem em atividade distratora (GC) e então fornecerem o diagnóstico final e o grau de confiança. Foram comparadas acurácia diagnóstica, confiança e calibragem diagnóstica globalmente, por síndrome dermatológica e por grau de dificuldade. Resultados: Foram incluídos 61 alunos, alocados 33 para GR e 28 para GC. Houve predominância de mulheres no GR, mas não houve diferença significativa de idade ou de auto-percepção do conhecimento/experiência prévios entre os grupos. Observou-se uma maior acurácia diagnóstica dos alunos do GR em relação ao GC tanto para síndromes melanocíticas (p=0,025) quanto para não-melanocíticas (p=0,022). Em relação à calibragem diagnóstica, tanto o GC (p=0,017) quanto o GR (p=0,001) apresentaram melhor calibragem para síndromes melanocíticas, sendo que para síndromes não-melanociticas o aluno apresenta maior excesso de confiança. A calibragem foi pior para os casos difíceis com os alunos apresentando excesso de confiança em relação ao seu real desempenho. A reflexão não impactou de maneira significativa em relação à confiança e calibragem de maneira global. Nos casos fáceis, houve diferença de calibragem entre GR e GC, observando-se no GR maior acurácia diagnóstica, mas com confiança semelhante à observada do GC, ocorrendo inversão do sinal da calibragem com os alunos tendo um desempenho levemente superior à sua confiança. Conclusão: A atividade reflexiva aumentou a acurácia diagnóstica de maneira global para as lesões dermatológicas testadas, mas não alterou globalmente a confiança e calibragem diagnóstica. A calibragem piorou nos casos mais difíceis e a reflexão não foi capaz de melhorar esta situação.
|
570 |
Albumina glicada como uma ferramenta de diagnóstico do diabetes mellitusChume, Fernando Chimela January 2018 (has links)
A prevalência de diabetes mellitus (DM) está aumentando constantemente em todo o mundo a uma taxa alarmante. Devido às suas complicações que causam uma maior morbidade, invalidez e mortalidade, o DM representa um enorme problema para a saúde pública. Com isso, ações, tanto em diagnóstico como em tratamento, são necessárias para desacelerar a tendência atual e prevenir o desenvolvimento das complicações do DM. Recentemente, a hemoglobina glicada (HbA1c) foi introduzida nos critérios diagnósticos de DM. Os resultados de HbA1c são igualmente apropriados para o diagnóstico, apesar de não necessariamente detectarem DM nos mesmos indivíduos detectados pelos critérios de glicemia. No entanto, os níveis de HbA1c podem ser influenciados por qualquer condição que altere a vida útil dos eritrócitos e metabolismo da hemoglobina, independentemente da glicemia, resultando em erro diagnóstico neste grupo da população com estas condições. Além disso, estudos epidemiológicos revelaram que a glicemia pós-prandial tem um maior risco de causar complicações cardiovasculares em relação à hiperglicemia persistente e pode ser acessada com precisão usando a albumina glicada (AG) e não a HbA1c. Nesse contexto, estudos recentes têm evidenciado que a AG pode ser um marcador para diagnóstico do DM e também ser utilizado como um marcador alternativo à HbA1c para o controle glicêmico. No entanto, esses estudos, foram realizados apenas na população asiática e podem não ser aplicáveis a outros grupos étnicos. Por isso, mais investigações para a validação do desempenho diagnóstico da AG na predição do DM em diferentes grupos etnicos são necessárias. Neste estudo avaliamos o desempenho da AG no diagnóstico do DM em 242 indivíduos brasileiros com idade média de 54,4 anos (+ 13,0). Baseando-se nos valores de glicose plasmática durante o teste oral de tolerância à glicose (TOTG), o DM foi detectado em 31,8%. AG ≥16,8% apresentou acurácia similar para a detecção de DM conforme definido por HbA1c >6,5%. O uso da razão glicemia de 2h pós-sobrecarga de 75g de glicose (2hPG) e AG (2hPG/AG) melhora a sensibilidade, reduz o número de diagnósticos incorretos por AG ou HbA1c >6,5% e possui um acurácia comparável ao TOTG, indicando que o uso de uma estratégia aplicando a razão da glicemia pós-prandial (GPP) real e AG (GPP/AG) pode ser mais conveniente para pacientes e aumentar o desempenho diagnóstico do teste. Estudos para validar esta estratégia são necessários. / The prevalence of diabetes mellitus (DM) is constantly increasing worldwide at an alarming rate. Due to its complications that cause greater morbidity, disability and mortality, DM represents a heavy burden on public health. Therefore, actions in both, diagnosis and treatment, are necessary to slow down the current tendency and avoid the development of DM complications. Recently, the glycated hemoglobin test (HbA1c) was introduced in the diagnostic criteria for DM. The HbA1c results are equally appropriate for diagnostic testing, though not necessarily detect DM in the same subjects detected by plasma glucose criteria. However, blood HbA1c levels may be influenced by any condition that changes the lifespan of erythrocytes and hemoglobin metabolism regardless of glycemia, resulting in the misdiagnosis of this population group. In addition, epidemiological studies have shown that postprandial glycemia has a higher risk of causing cardiovascular complications than chronic hyperglycemia and can be accurately assessed using the glycated albumin (GA) test rather than HbA1c. In this context, recent studies have shown that GA may be a marker for the diagnosis of DM and also be used as an alternative marker to HbA1c on many occasions. However, these studies have been conducted only in the Asian population and may not be applicable to other ethnic groups. Therefore, further investigations to validate the diagnostic performance of GA in the prediction of DM in different ethnic groups are necessary. In this study, we evaluated the GA performance in the diagnosis of DM in 242 Brazilian individuals with a mean age of 54.4 years (+ 13.0). Based on plasma glucose values during oral glucose tolerance test (OGTT), DM was detected in 31.8%. AG ≥16.8% presented similar accuracy for detecting DM as defined by a HbA1c >6.5%. The use of the 2-h plasma glucose after a 75-g OGTT and GA (2hPG/GA) ratio improves sensitivity, reduces the number of incorrect diagnoses by GA or HbA1c >6.5% and has an accuracy comparable to OGTT, indicating that the use of approach applying the postprandial glucose (PPG) and GA (PPG/GA) may be more convenient for patients and increase the diagnostic performance of the test. Studies to validate this approach are needed.
|
Page generated in 0.044 seconds