Color edges extraction using statistical features and automatic threshold technique: application to the breast cancer cells

BACKGROUND: Color image segmentation has been so far applied in many areas; hence, recently many different techniques have been developed and proposed. In the medical imaging area, the image segmentation may be helpful to provide assistance to doctor in order to follow-up the disease of a certain patient from the breast cancer processed images. The main objective of this work is to rebuild and also to enhance each cell from the three component images provided by an input image. Indeed, from an initial segmentation obtained using the statistical features and histogram threshold techniques, the resulting segmentation may represent accurately the non complete and pasted cells and enhance them. This allows real help to doctors, and consequently, these cells become clear and easy to be counted. METHODS: A novel method for color edges extraction based on statistical features and automatic threshold is presented. The traditional edge detector, based on the first and the second order neighborhood, describing the relationship between the current pixel and its neighbors, is extended to the statistical domain. Hence, color edges in an image are obtained by combining the statistical features and the automatic threshold techniques. Finally, on the obtained color edges with specific primitive color, a combination rule is used to integrate the edge results over the three color components. RESULTS: Breast cancer cell images were used to evaluate the performance of the proposed method both quantitatively and qualitatively. Hence, a visual and a numerical assessment based on the probability of correct classification (P( C )), the false classification (P( f )), and the classification accuracy (Sens(%)) are presented and compared with existing techniques. The proposed method shows its superiority in the detection of points which really belong to the cells, and also the facility of counting the number of the processed cells. CONCLUSIONS: Computer simulations highlight that the proposed method substantially enhances the segmented image with smaller error rates better than other existing algorithms under the same settings (patterns and parameters). Moreover, it provides high classification accuracy, reaching the rate of 97.94%. Additionally, the segmentation method may be extended to other medical imaging types having similar properties

A FETI method with a mesh independent condition number for the iteration matrix

We introduce a framework for FETI methods using ideas from the decomposition via Lagrange multipliers of H1 0 (Ω) derived by Raviart-Thomas [22] P.-A. Raviart, J.-M. Thomas, Primal Hybrid Finite Element Metho and complemented with the detailed work on polygonal domains developed by Grisvard [17] P. Grisvard, Singularities in Boundary value problems. Recherches en Mathématiques Appliquées, 22. Masson, 1992.. We compute the action of the Lagrange multipliers using the natural H 1/2 00 scalar product, therefore no consistency error appears. As a byproduct, we obtain that the condition number for the iteration matrix is independent of the mesh size and there is no need for preconditioning. This result improves the standard asymptotic bound for this condition number shown by Mandel-Tezaur in [19] J. Mandel, R. Tezaur, Convergence of a substructuring method with Lagrange multipliers. Numer. Math., 73 (1996), 473–487. Numerical results that confirm our theoretical analysis are presented.Nous proposons une nouvelle approche des méthodes FETI: la décomposition de domaine fait appel aux multiplicateurs de Lagrange tels qu’introduits par Raviart-Thomas [22] P.-A. Raviart, J.-M. Thomas, Primal Hybrid Finite Element Methods for second order eliptic equations. Math. Comp., 31 (1977), 391-413 et au traitement des domaines polygonaux dù á Grisvard [17] P. Grisvard, Singularities in Boundary value problems. Recherches en Mathématiques Appliquées, 22. Masson, 1992. Ces multiplicateurs utilisent le produit scalaire de H 1/2 00, de sorte qu’aucune erreur de consistance n’apparaît. En outre, nous prouvons que le nombre de condition de la matrice liée à chaque itération est indépendant de la taille du maillage, ce qui améliore le résultat de Mandel-Tezaur [19] J. Mandel, R. Tezaur, Convergence of a substructuring method with Lagrange multipliers. Numer. Math., 73 (1996), 473–487; par suite, aucun préconditionnement n’est nécessaire. Nous présentons des expériences numériques qui confirment notre analyse.Ministerio de Educación y Cienci

Intracardiac thrombus in Behçet's disease: Two case reports

Intracardiac thrombus in Behçet's disease is an extremely rare manifestation. We report two such cases. A 20-year-old man presented with dyspnoea, cough and haemoptysis. Right heart thrombus associated with pulmonary artery aneurysm and thromboembolism was identified by helical CT and transoesophageal echocardiography. The second case was a 29-year-old male admitted for fever and chest pain. A diagnosis of right atrial thrombosis associated with pulmonary embolism and hyperhomocysteinemia was made. Due to the absence of haemodynamic compromise, medical management consisting of immunosupressive and anticoagulation therapy was adopted which resulted in complete dissolution of the thrombus with dramatic clinical improvement in both cases of clinical status. Conclusion: intracardiac thrombus is a rare complication of Behçet's disease. As shown in our patients, medical treatment should be considered as the first line

Linear feature selection and classification using PNN and SFAM neural networks for a nearly online diagnosis of bearing naturally progressing degradations.

International audienceIn this work, an effort is made to characterize seven bearing states depending on the energy entropy of Intrinsic Mode Functions (IMFs) resulted from the Empirical Modes Decomposition (EMD).Three run-to-failure bearing vibration signals representing different defects either degraded or different failing components (roller, inner race and outer race) with healthy state lead to seven bearing states under study. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) are used for feature reduction. Then, six classification scenarios are processed via a Probabilistic Neural Network (PNN) and a Simplified Fuzzy Adaptive resonance theory Map (SFAM) neural network. In other words, the three extracted feature data bases (EMD, PCA and LDA features) are processed firstly with SFAM and secondly with a combination of PNN-SFAM. The computation of classification accuracy and scattering criterion for each scenario shows that the EMD-LDA-PNN-SFAM combination is the suitable strategy for online bearing fault diagnosis. The proposed methodology reveals better generalization capability compared to previous works and it’s validated by an online bearing fault diagnosis. The proposed strategy can be applied for the decision making of several assets

Evaluation of the implementation of the objective structured clinical examination in health sciences education from a low‐income context in Tunisia: A cross‐sectional study

© 2024 The Author(s). Health Science Reports published by Wiley Periodicals LLC. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Background: Objective structured clinical examination (OSCE) is well‐established and designed to evaluate students' clinical competence and practical skills in a standardized and objective manner. While OSCEs are widespread in higher‐income countries, their implementation in low‐resource settings presents unique challenges that warrant further investigation. Aim: This study aims to evaluate the perception of the health sciences students and their educators regarding deploying OSCEs within the School of Health Sciences and Techniques of Sousse (SHSTS) in Tunisia and their efficacity in healthcare education compared to traditional practical examination methods. Methods: This cross‐sectional study was conducted in June 2022, focusing on final‐year Health Sciences students at the SHSTS in Tunisia. The study participants were students and their educators involved in the OSCEs from June 6th to June 11th, 2022. Anonymous paper‐based 5‐point Likert scale satisfaction surveys were distributed to the students and their educators, with a separate set of questions for each. Spearman, Mann–Whitney U and Krusakll–Wallis tests were utilized to test the differences in satisfaction with the OSCEs among the students and educators. The Wilcoxon Rank test was utilized to examine the differences in students' assessment scores in the OSCEs and the traditional practical examination methods. Results: The satisfaction scores were high among health sciences educators and above average for students, with means of 3.82 ± 1.29 and 3.15 ± 0.56, respectively. The bivariate and multivariate analyzes indicated a significant difference in the satisfaction between the students' specialities. Further, a significant difference in their assessment scores distribution in the practical examinations and OSCEs was also demonstrated, with better performance in the OSCEs. Conclusion: Our study provides evidence of the relatively high level of satisfaction with the OSCEs and better performance compared to the traditional practical examinations. These findings advocate for the efficacy of OSCEs in low‐income countries and the need to sustain them.Peer reviewe

A life in waiting: Refugees' mental health and narratives of social suffering after European Union border closures in March 2016.

RATIONALE: In 2015, an estimated 856,723 refugees, predominantly from Syria, Afghanistan, and Iraq arrived in Greece as an entry point into the European Union. The border of the Former Yugoslav Republic of Macedonia closed in March 2016, blocking a popular route for refugees through Europe, and left around 60,000 people stranded in Greece. OBJECTIVE: A mixed-method study was conducted among refugees in the regions of Attica, Epirus, and Samos between November 2016 and February 2017. The epidemiological survey showed that depending on study sites between 73% and 100% of the refugees suffered from anxiety disorder. The explanatory qualitative study aimed to understand refugees' mental health and narratives of social suffering in regards to experienced violence, the effect of current border closures, and the lack of an onward journey. METHOD: The explanatory qualitative study included 47 in-depth interviews and five focus group discussions with refugees purposely recruited through the concomitant epidemiological survey, representing both genders and a range of nationalities and ages. Data were thematically analysed to identify emergent patterns and categories using NVivo 11. RESULTS: The refugees overwhelmingly reported experiencing uncertainty and lack of control over their current life and future, which caused psychosocial distress and suffering. The passivity of life in refugee camps aggravated feelings of meaninglessness and powerlessness. The disruption of key social networks and absence of interactions with the surrounding Greek society led to feelings of isolation and being unwelcome. CONCLUSIONS: Refugees in Greece experience psychosocial distress and social suffering as a consequence of their uncertain and disrupted lives and the loss of social networks. Faster and transparent asylum procedures, the development of meaningful and empowering activities, and fostered social interactions with the surrounding society would contribute to alleviating their psychosocial suffering

Frequency converter implementing an optical analogue of the cosmological redshift

According to general relativity, the frequency of electromagnetic radiation is altered by the expansion of the universe. This effect--commonly referred to as the cosmological redshift--is of utmost importance for observations in cosmology. Here we show that this redshift can be reproduced on a much smaller scale using an optical analogue inside a dielectric metamaterial with time-dependent material parameters. To this aim, we apply the framework of transformation optics to the Robertson-Walker metric. We demonstrate theoretically how perfect redshifting or blueshifting of an electromagnetic wave can be achieved without the creation of sidebands with a device of finite length.Comment: 6 pages, 3 figure

A comparison of self-report and antiretroviral detection to inform estimates of antiretroviral therapy coverage, viral load suppression and HIV incidence in Kwazulu-Natal, South Africa

Accurately identifying individuals who are on antiretroviral therapy (ART) is important to determine ART coverage and proportion on ART who are virally suppressed. ART is also included in recent infection testing algorithms used to estimate incidence. We compared estimates of ART coverage, viral load suppression rates and HIV incidence using ART self-report and detection of antiretroviral (ARV) drugs and we identified factors associated with discordance between the methods

Syrian refugees in Greece: experience with violence, mental health status, and access to information during the journey and while in Greece.

BACKGROUND: Since 2015, Europe has been facing an unprecedented arrival of refugees and migrants: more than one million people entered via land and sea routes. During their travels, refugees and migrants often face harsh conditions, forced detention, and violence in transit countries. However, there is a lack of epidemiological quantitative evidence on their experiences and the mental health problems they face during their displacement. We aimed to document the types of violence experienced by migrants and refugees during their journey and while settled in Greece, and to measure the prevalence of anxiety disorders and access to legal information and procedures. METHODS: We conducted a cross-sectional population-based quantitative survey combined with an explanatory qualitative study in eight sites (representing the range of settlements) in Greece during winter 2016/17. The survey consisted of a structured questionnaire on experience of violence and an interviewer-administered anxiety disorder screening tool (Refugee Health Screener). RESULTS: In total, 1293 refugees were included, of whom 728 were Syrians (41.3% females) of median age 18 years (interquartile range 7-30). Depending on the site, between 31% and 77.5% reported having experienced at least one violent event in Syria, 24.8-57.5% during the journey to Greece, and 5-8% in their Greek settlement. Over 75% (up to 92%) of respondents ≥15 years screened positive for anxiety disorder, which warranted referral for mental health evaluation, which was only accepted by 69-82% of participants. Access to legal information and assistance about asylum procedures were considered poor to non-existent for the majority, and the uncertainty of their status exacerbated their anxiety. CONCLUSIONS: This survey, conducted during a mass refugee crisis in a European Community country, provides important data on experiences in different refugee settings and reports the high levels of violence experienced by Syrian refugees during their journeys, the high prevalence of anxiety disorders, and the shortcomings of the international protective response