Prediction of arrhythmia susceptibility through mathematical modeling and machine learning

At present, the QT interval on the electrocardiographic (ECG) waveform is the most common metric for assessing an individual’s susceptibility to ventricular arrhythmias, with a long QT, or, at the cellular level, a long action potential duration (APD) considered high risk. However, the limitations of this simple approach have long been recognized. Here, we sought to improve prediction of arrhythmia susceptibility by combining mechanistic mathematical modeling with machine learning (ML). Simulations with a model of the ventricular myocyte were performed to develop a large heterogenous population of cardiomyocytes (n = 10,586), and we tested each variant’s ability to withstand three arrhythmogenic triggers: 1) block of the rapid delayed rectifier potassium current (IKr Block), 2) augmentation of the L-type calcium current (ICaL Increase), and 3) injection of inward current (Current Injection). Eight ML algorithms were trained to predict, based on simulated AP features in preperturbed cells, whether each cell would develop arrhythmic dynamics in response to each trigger. We found that APD can accurately predict how cells respond to the simple Current Injection trigger but cannot effectively predict the response to IKr Block or ICaL Increase. ML predictive performance could be improved by incorporating additional AP features and simulations of additional experimental protocols. Importantly, we discovered that the most relevant features and experimental protocols were trigger specific, which shed light on the mechanisms that promoted arrhythmia formation in response to the triggers. Overall, our quantitative approach provides a means to understand and predict differences between individuals in arrhythmia susceptibility.

Strain-Stress Distribution of Structural Components from Foam Concrete for Monolithic Construction

The problem of use of hi-tech macroporous concrete in load-carrying structures of low-rise buildings is designated and the forthcoming research problems of power resistance and deformation of the compressed and bent elements from foam concrete of natural solidification are formulated. Results of pilot researches of intense state of strain of the compressed and bent elements from foam concrete of average density of 1200-1600 kg/m3 of different structural modification in the conditions of short-term and long action of loading are provided. It is established that foam concrete meet for nonrigid indicators regulatory requirements and take the intermediate place between full-strength cellular and light concrete on expanded aggregates that creates premises for their successful application in the bearing concrete and reinforced concrete constructions. Deformation and strength characteristics of foam concrete of different structural modifications taking into account the impact of the long processes caused by solidification of concrete and external power factors, necessary for calculation and structural design are offered. The received results of researches will allow to project rationally bearing and enclosing structures from foam concrete that leads to increase in technological level of monolithic construction.

Efeito da nuliparidade na inserção, reações adversas e taxas de continuidade dos dispositivos intrauterinos

Introdução: Os dispositivos intrauterinos (DIU) são excelentes métodos contraceptivos, denominados LARCs (Long-Action Reversible Contraception). O DIU de cobre é um método contraceptivo muito utilizado, com alta eficácia (índice de Pearl de 0,2‒0,4), e tem excelente custo-benefício, podendo ser obtido e inserido na rede pública de saúde. Há alguns profissionais de saúde e pessoas leigas que advogam se a nuliparidade é um fator impeditivo para o uso do DIU, por haver maior dificuldade na inserção e maior taxa de expulsão da cavidade endometrial. Objetivos: Avaliar se a nuliparidade está associada ao maior desconforto na inserção e à taxa de sucesso quando realizada ambulatorialmente. Além disso, o estudo visou analisar a taxa de satisfação e continuidade do uso dos DIU entre mulheres com e sem filhos. Pacientes e Métodos: Estudo descritivo por meio da aplicação de formulário on-line (Google Forms®), não validado e desenvolvido pelos pesquisadores. O formulário foi distribuído em grupos específicos das redes sociais e do WhatsApp®, estando disponível para respostas entre os meses de abril e maio de 2020. Só participaram do estudo mulheres que afirmaram ter mais de 18 anos e que usam ou já utilizaram DIU de cobre. Para a análise do desconforto durante a inserção foi utilizada a escala visual analógica (EVA). Os dados foram inseridos no programa Microsoft Office Excel 2016®. Para identificar a homogeneidade da amostra, foram utilizados o programa GraphPad InStat v. 3.0 para Windows 10, GraphPad Software, San Diego California USA, e o teste de Kolmogorov-Smirnov; para variáveis categóricas, foi utilizado o teste χ2 ou de Fisher; e para variáveis contínuas, o teste de Mann-Whitney ou Kruskall-Wallis. Para significância estatística dos resultados, foi adotado p<0,05. Resultados: Participaram da pesquisa 3.066 mulheres, sendo 1.844 nuligestas e 1.222 com filhos. As nuligestas apresentaram maior desconforto na inserção do DIU (EVA 7 nuligestas versus EVA 5 mulheres com filhos; p<0,0001), mas não houve diferença nas taxas de sucesso de inserção desse método contraceptivo no consultório (97,3% nuligestas versus 97,8% mulheres com filhos, p=0,53). A síncope vasovagal não diferiu entre os grupos. As taxas de continuidade e as principais reações adversas foram poucas e não diferiram entre os grupos (p>0,05). Conclusões: A nuliparidade está associada ao maior desconforto durante a inserção do DIU, mas as taxas de sucesso da inserção ambulatorial são iguais entre nuligestas e mulheres com filhos. As taxas de continuidade e reações adversas são similares entre os grupos estudados. A nuliparidade não é fator impeditivo para uso do DIU.

Rewriting the Meaning of Silence: Latin American Migrant Workers from Kanagawa City Union

This chapter discusses how migrant workers of Kanagawa City Union (KCU), who are largely from Latin American countries, participated in the annual negotiation meeting with government representatives and the union's well-known activity called ‘Day Long Action’. Japanese is predominantly used in these events, with little effort to translate for non-Japanese-speaking participants. While the previous chapter looks at an instance where migrant protesters challenge the gap between their visibility and audibility, this chapter shows that they strategically use such a gap for their own benefit. For some migrants, being unable to understand Japanese is not a hindrance but a convenient pretext to follow what they are ordered to do. In this regard, silence gives them an opportunity to perform their loyalty to the trade unions they belong to. Demonstration of such loyalty is a key strategy for KCU migrant members because it is Japanese unionists who ultimately handle migrants' labour disputes.

PPIUCD: awareness and reasons for non-acceptance

Background: The recommended interval between pregnancies is at least 24 months in order to reduce the risk of adverse maternal, perinatal and infant outcomes. Ministry of Health & Family Welfare, Government of India has taken initiative for provision of IUCD in immediate postpartum period. Several training programs and awareness camps are conducted by NHM for health service providers and also for the public. The aim of the study was to determine proportion of women accepting post placental intrauterine Contraceptive Device insertion, and to describe the factors associated with acceptability and non-acceptance.Methods: The study was conducted at the Government Medical College Thrissur, Kerala, India and study period was 1 year (2014-2015). The study population included women who planned to deliver at Government Medical College, Thrissur during the study period including vaginal and caesarean section.Results: The awareness regarding PPIUCD was only 11.1% whereas for interval IUCD it was 94.9%. The acceptance rate of PPIUCD was very low (10.5%). The most common reason to accept was its long action (68.5%) The most common reason for rejection was that they wanted permanent sterilisation. The other reasons for non-acceptance include unwillingness of husband, fear of complications etc.Conclusions: The acceptance rate was very low even though majority of the study population were well educated. The most common reason for acceptance was long action followed by reversibility.The reasons for refusal like unwillingness of husband, fear of complications etc. can be overcome by proper counselling and public awareness programs.