70 research outputs found

    Использование вейвлет-преобразования при локализации последовательностей символов

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    В статье предложен метод автоматического определения масштаба вейвлет-преобразования при локализации квазипериодических последовательностей (текстур, областей с символьной информацией и т.д.) путем анализа функции энергии коэффициентов вейвлет-преобразования. Реализация предложенного метода при разработке приложений, связанных с локализацией и распознаванием символьной информации, повысила универсальность таких систем за счет повышения точности локализации символьной информации путем автоматизации выбора масштаба вейвлет-преобразования.У статті запропоновано метод автоматичного визначення масштабу вейвлет-перетворення при локалізації квазіперіодичних послідовностей (текстур, областей з символьною інформацією (СІ) тощо) шляхом аналізу функції енергії коефіцієнтів вейвлет-перетворення. Реалізація методу при розробці додатків, які пов’язані з локалізацією та розпізнаванням символьної інформації, підвищила універсальність таких систем за рахунок збільшення точності локалізації СІ шляхом автоматизації вибору масштабу вейвлет-перетворення.Method of automatically determining wavelet transform scale on the base of analyzing the function of the energy wavelet transform coefficients is proposed. It is used for localization of quasiperiodic sequences (patterns, areas with character information, etc.). The proposed method is used in image processing systems related to the localization and recognition of the symbolic information. It is allowed to increase versatility of such systems by improving the accuracy localization of the symbolic information by automating choice of scale wavelet transform

    Trends over time in congenital malformations in live-born children conceived after assisted reproductive technology

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    IntroductionChildren born after assisted reproductive technology, particularly singletons, have been shown to have an increased risk of congenital malformations compared with children born after spontaneous conception. We wished to study whether there has been a change in the past 20 years in the risk of major congenital malformations in children conceived after assisted reproductive technology compared with children spontaneously conceived. Material and methodsPopulation-based cohort study including 90 201 assisted reproductive technology children and 482 552 children spontaneously conceived, born in Denmark, Finland, Norway and Sweden. Both singletons and twins born after in vitro fertilization, intracytoplasmatic sperm injection and frozen embryo transfer were included. Data on children were taken from when the national Nordic assisted reproductive technology registries were established until 2007. Multiple logistic regression analyses were used to estimate the risks and adjusted odds ratios for congenital malformations in four time periods: 1988-1992, 1993-1997, 1998-2002 and 2003-2007. Only major malformations were included. ResultsThe absolute risk for singletons of being born with a major malformation was 3.4% among assisted reproductive technology children vs. 2.9% among children spontaneously conceived during the study period. The relative risk of being born with a major congenital malformation between all assisted reproductive technology children and children spontaneously conceived remained similar through all four time periods (p = 0.39). However, we found that over time the number of children diagnosed with a major malformation increased in both groups across all four time periods. ConclusionWhen comparing children conceived after assisted reproductive technology and spontaneously conceived, the relative risk of being born with a major congenital malformation did not change during the study period.Peer reviewe

    Greenland surface mass-balance observations from the ice-sheet ablation area and local glaciers

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    Glacier surface mass-balance measurements on Greenland started more than a century ago, but no compilation exists of the observations from the ablation area of the ice sheet and local glaciers. Such data could be used in the evaluation of modelled surface mass balance, or to document changes in glacier melt independently from model output. Here, we present a comprehensive database of Greenland glacier surface mass-balance observations from the ablation area of the ice sheet and local glaciers. The database spans the 123 a from 1892 to 2015, contains a total of similar to 3000 measurements from 46 sites, and is openly accessible through the PROMICE web portal (http://www.promice.dk). For each measurement we provide X, Y and Z coordinates, starting and ending dates as well as quality flags. We give sources for each entry and for all metadata. Two thirds of the data were collected from grey literature and unpublished archive documents. Roughly 60% of the measurements were performed by the Geological Survey of Denmark and Greenland (GEUS, previously GGU). The data cover all regions of Greenland except for the southernmost part of the east coast, but also emphasize the importance of long-term time series of which there are only two exceeding 20 a. We use the data to analyse uncertainties in point measurements of surface mass balance, as well as to estimate surface mass-balance profiles for most regions of Greenland

    Comparison of vaccine-induced antibody neutralization against SARS-CoV-2 variants of concern following primary and booster doses of COVID-19 vaccines

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    The SARS-CoV-2 pandemic has, as of July 2022, infected more than 550 million people and caused over 6 million deaths across the world. COVID-19 vaccines were quickly developed to protect against severe disease, hospitalization and death. In the present study, we performed a direct comparative analysis of four COVID-19 vaccines: BNT162b2 (Pfizer/BioNTech), mRNA-1273 (Moderna), ChAdOx1 (Oxford/AstraZeneca) and Ad26.COV2.S (Johnson & Johnson/Janssen), following primary and booster vaccination. We focused on the vaccine-induced antibody-mediated immune response against multiple SARS-CoV-2 variants: wildtype, B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617.2 (Delta) and B.1.1.529 (Omicron). The analysis included the quantification of total IgG levels against SARS-CoV-2 Spike, as well as the quantification of antibody neutralization titers. Furthermore, the study assessed the high-throughput ACE2 competition assay as a surrogate for the traditional pseudovirus neutralization assay. The results demonstrated marked differences in antibody-mediated immune responses. The lowest Spike-specific IgG levels and antibody neutralization titers were induced by one dose of the Ad26.COV2.S vaccine, intermediate levels by two doses of the BNT162b2 vaccine, and the highest levels by two doses of the mRNA-1273 vaccine or heterologous vaccination of one dose of the ChAdOx1 vaccine and a subsequent mRNA vaccine. The study also demonstrated that accumulation of SARS-CoV-2 Spike protein mutations was accompanied by a marked decline in antibody neutralization capacity, especially for B.1.1.529. Administration of a booster dose was shown to significantly increase Spike-specific IgG levels and antibody neutralization titers, erasing the differences between the vaccine-induced antibody-mediated immune response between the four vaccines. The findings of this study highlight the importance of booster vaccines and the potential inclusion of future heterologous vaccination strategies for broad protection against current and emerging SARS-CoV-2 variants

    A registry-based follow-up study, comparing the incidence of cardiovascular disease in native Danes and immigrants born in Turkey, Pakistan and the former Yugoslavia: do social inequalities play a role?

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    <p>Abstract</p> <p>Background</p> <p>This study compared the incidence of cardiovascular disease (CVD) and acute myocardial infarction (AMI) between native Danes and immigrants born in Turkey, Pakistan and the former Yugoslavia. Furthermore, we examined whether different indicators of socioeconomic status (SES), such as employment, income and housing conditions influenced potential differences.</p> <p>Methods</p> <p>In this registry-based follow-up study individuals were identified in a large database that included individuals from two major regions in Denmark, corresponding to about 60% of the Danish population. Incident cases of CVD and AMI included fatal and non-fatal events and were taken from registries. Using Cox regression models, we estimated incidence rates at 5-year follow-up.</p> <p>Results</p> <p>Immigrant men and women from Turkey and Pakistan had an increased incidence of CVD, compared with native Danish men. In the case of AMI, a similar pattern was observed; however, differences were more pronounced. Pakistanis and Turks with a shorter duration of residence had a lower incidence, compared with those of a longer residence. Generally, no notable differences were observed between former Yugoslavians and native Danes. In men, differences in CVD and AMI were reduced after adjustment for SES, in particular, among Turks regarding CVD. In women, effects were particularly reduced among Yugoslavians in the case of CVD and in Turks in the case of CVD and AMI after adjustment for SES.</p> <p>Conclusions</p> <p>In conclusion, country of birth-related differences in the incidence of CVD and AMI were observed. At least some of the differences that we uncovered were results of a socioeconomic effect. Duration of residence also played a certain role. Future studies should collect and test different indicators of SES in studies of CVD among immigrants.</p
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