15 research outputs found

    Classification of Caesarean Section and Normal Vaginal Deliveries Using Foetal Heart Rate Signals and Advanced Machine Learning Algorithms

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    ABSTRACT – Background: Visual inspection of Cardiotocography traces by obstetricians and midwives is the gold standard for monitoring the wellbeing of the foetus during antenatal care. However, inter- and intra-observer variability is high with only a 30% positive predictive value for the classification of pathological outcomes. This has a significant negative impact on the perinatal foetus and often results in cardio-pulmonary arrest, brain and vital organ damage, cerebral palsy, hearing, visual and cognitive defects and in severe cases, death. This paper shows that using machine learning and foetal heart rate signals provides direct information about the foetal state and helps to filter the subjective opinions of medical practitioners when used as a decision support tool. The primary aim is to provide a proof-of-concept that demonstrates how machine learning can be used to objectively determine when medical intervention, such as caesarean section, is required and help avoid preventable perinatal deaths. Methodology: This is evidenced using an open dataset that comprises 506 controls (normal virginal deliveries) and 46 cases (caesarean due to pH ≤7.05 and pathological risk). Several machine-learning algorithms are trained, and validated, using binary classifier performance measures. Results: The findings show that deep learning classification achieves Sensitivity = 94%, Specificity = 91%, Area under the Curve = 99%, F-Score = 100%, and Mean Square Error = 1%. Conclusions: The results demonstrate that machine learning significantly improves the efficiency for the detection of caesarean section and normal vaginal deliveries using foetal heart rate signals compared with obstetrician and midwife predictions and systems reported in previous studies

    Simplified skin-effect formulation for power transmission lines

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)This study presents a simplified formulation to calculate the skin effect on transmission lines wires. The methodology is developed from the solution of the time-domain Maxwell's wave equations whose frequency-domain solutions are obtained using Fourier transforms. Results obtained from the proposed formulation are compared with those calculated using the conventional method based on the approach by Bessel functions. The proposed skin-effect formulation is also validated based on electromagnetic transients simulations in the time domain considering a conventional 69-kV transmission system.824753Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [Proc. 2013/00974-5]CAPES [Procs. PDSE 4570/11-1, PDSE 6851/12-6

    Nematode Parasites of Brazilian Corvid Birds (Passeriformes): A General Survey with a Description of Viktorocara brasiliensis n. sp. (Acuariidae, Schistorophinae)

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    This report deals with the identification of 139 samples of nematodes recovered from Brazilian jays. Viktorocara brasiliensis n. sp. is proposed and compared with V. capillaris, V. limosae, V. charadrii and V. garridoi which are the other species included in the genus. The differentiation of V. brasiliensis n. sp. was based on the ratios between muscular and glandular esophagus and spicules, as well. Other referred species are Acuaria mamillaris, A. mayori, Aprocta sp., Cheilospirura sp., Diplotriaena americana, D. bargusinica, Oxyspirura matogrosensis, Oxyspirura sp., Pelecitus helicinus, Procyrnea sp., Skrjabinura spiralis, Subulura papillosa, Synhimantus sp. and Tetrameres (Microtetrameres) sp., with the establishment of some new host record

    Nematode parasites of Brazilian piciformes birds: a general survey with description of Procyrnea anterovulvata n. sp. (Habronematoidea, Habronematidae)

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    Thirty species of nematodes recovered from Piciformes hosts are reported. Procyrnea anterovulvata n. sp. from Chelidoptera tenebrosa brasiliensis is described and compared to P. colaptes and P. pileata. The considered morphometric parameters are mainly related to the ratio between length of the body/distance of the vulva to the anterior end. It is approximately 1:0.5 in P. colaptes and P. pileata compared to 1:0.1 in the new species. The male of Synhimantus (Dispharynx) crassissima is described for the first time. Thelazia (Thelaziella) spizaeti is revalidated and new records are reported for some species
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