23 research outputs found

    CIFAR-10: KNN-based Ensemble of Classifiers

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    In this paper, we study the performance of different classifiers on the CIFAR-10 dataset, and build an ensemble of classifiers to reach a better performance. We show that, on CIFAR-10, K-Nearest Neighbors (KNN) and Convolutional Neural Network (CNN), on some classes, are mutually exclusive, thus yield in higher accuracy when combined. We reduce KNN overfitting using Principal Component Analysis (PCA), and ensemble it with a CNN to increase its accuracy. Our approach improves our best CNN model from 93.33% to 94.03%

    The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

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    DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Defected concrete post detection through antenna array coupling effect

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    In this paper, a proposed defected concrete post detection system is introduced. The proposed system consists of two compact microstrip broad side antenna arrays resonating at 1 GHz with dimensions of 45 cm by 13.2 cm for each antenna array and a weight of 800 gm for both antenna arrays. Also a portable vector network analyser is used for scattering parameters measurement purpose. For size comparison purpose, a conventional microstrip antenna array is designed and compared with the proposed one at the same resonant frequency. A size reduction of 23.4 % is obtained. The proposed antenna array directivity of 10.5 dBi and 3 dB beam width of 30.7 are obtained which are suitable for the concrete post defect detection. The detection principle is relied on the coupling between the two antenna array elements. Three cases are considered for simulation and measurement, air, good concrete block and defected concrete block. A 10 dB difference in coupling was obtained between the presence and the absence of the defect in the concrete block. A proposed measurement system is introduced. Good agreement is obtained between measured and simulated results. The proposed defected concrete post detection system is noticed to be light weight, simple, cheap and has a reasonable accuracy level

    The global retinoblastoma outcome study: A prospective, cluster-based analysis of 4064 patients from 149 countries

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    Background: Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival.Methods: We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models.Findings: The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0-36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8-100·0) for children from high-income countries, 91·2% (89·5-93·0) for children from upper-middle-income countries, 80·3% (78·3-82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76-50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44-18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23-1·56). For children aged 3-7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope).Interpretation: This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.Funding: Queen Elizabeth Diamond Jubilee Trust

    National screening for developmental delays and their determinants among Egyptian school age children: A step towards implementing life skills programs.

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    AimThis study aimed to estimate the national prevalence of developmental delays (DDs) and their determinants among Egyptian children aged 6 to 12 years. Such estimation is a prerequisite step toward the application of Life Skill Education (LSE) programs that will potentiate children's future capabilities.MethodsVineland Adaptive Behavior Scales" was used as a reliable and diagnostic test for DDs screening during this national cross sectional study. Gross motor (GM), fine motor (FM), daily living skills, communication, and socialization skills were assessed. The multivariate logistic regression analysis was used to identify factors associated with DDs. The Adjusted Odds Ratio (AOR) with a 95% Confidence Interval was estimated to indicate the strength of association. A p-value of ResultsOut of the 20324 surveyed school-aged children, 7.4% were found to have at least one delay. Communication deficits were the most common (6.4%) followed by delay in daily living skills (2.0%). The final model of logistic regression had a good fit for seven variables out of the sociodemographic, epidemiological characteristics, maternal and perinatal problems that were associated with a higher likelihood of at least one DD: Children suffering from any convulsions (AOR = 4.32; 95% CI: 3.18-5.88), male gender (AOR = 1.86; 95% CI: 1.65-2.09), birth weight less than 2.5 kg (AOR = 1.77; 95% CI: 1.40-2.24), history of maternal health problem during pregnancy (AOR = 1.64; 95% CI:1.34-2.01), children staying in an incubator for more than two days (AOR = 1.57, 95% CI: 1.29-1.91), having less educated fathers (AOR = 1.55, 95% CI: 1.24-1.95) and belonging to the middle social class (AOR = 1.40, 95% CI: 1.24-1.58).ConclusionThe identified types and determinants for each DD are allowing for the implementation of tailored programs for school children's life skills promotion for achieving the most sustainable effects on children's biological and psychological health and well-being
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