The tobacco industry in South Korea since market liberalisation : implications for strengthening tobacco control

This research analyses transnational tobacco companies' (TTCs) broader strategies for market access and demand creation through understanding market liberalisation in South Korea's tobacco industry from the late 1980s in order to inform the strengthening of tobacco control policies within the country and other emerging markets. The research is mainly based on internal tobacco industry documents, made publicly available through litigation. Detailed analysis of industry documents related to South Korea has not been undertaken to date. Semistructured interviews and additional primary and secondary sources served as important supplementary data sources. The key finding of this research is that the market access strategies of TTCs, including direct and indirect lobbying on trade policies, were a response to South Korea's export-oriented economic development model and its negative attitude towards foreign investment. This was undertaken within the context of the transformation of the world trading system from the 1980s which created pressure on the country to open its market. After liberalisation, various aggressive marketing tactics to create demand for foreign brands were used by TTCs. The competition this engendered played a key role in the transformation of the Korean tobacco monopoly into a private, competitive business which emulated and refined the tactics used by TTCs. This, in turn, increased the extent and intensity of the aggressive marketing of tobacco products in Korea overall. Total volume of cigarette sales increased 25% as a result, making Korea the 8th largest tobacco market in the world by 1992, whilst smoking prevalence increased among young adults and females. The research concludes that a fuller understanding of TTCs' strategies for global expansion can be derived by locating them within the economic development models of specific countries or regions. Such analysis, in turn, offers important lessons for strengthening global tobacco control. Of foremost importance is the need for emerging markets to appropriately balance economic and public health policies when considering liberalisation. The South Korean experience also demonstrates that comprehensive tobacco control policies, as set out by the Framework Convention on Tobacco Control, must be implemented prior to any market liberalisation and strictly enforced within a competitive market environment

Huber means on Riemannian manifolds

This article introduces Huber means on Riemannian manifolds, providing a robust alternative to the Frechet mean by integrating elements of both square and absolute loss functions. The Huber means are designed to be highly resistant to outliers while maintaining efficiency, making it a valuable generalization of Huber's M-estimator for manifold-valued data. We comprehensively investigate the statistical and computational aspects of Huber means, demonstrating their utility in manifold-valued data analysis. Specifically, we establish minimal conditions for ensuring the existence and uniqueness of the Huber mean and discuss regularity conditions for unbiasedness. The Huber means are statistically consistent and enjoy the central limit theorem. Additionally, we propose a moment-based estimator for the limiting covariance matrix, which is used to construct a robust one-sample location test procedure and an approximate confidence region for location parameters. Huber means are shown to be highly robust and efficient in the presence of outliers or under heavy-tailed distribution. To be more specific, it achieves a breakdown point of at least 0.5, the highest among all isometric equivariant estimators, and is more efficient than the Frechet mean under heavy-tailed distribution. Numerical examples on spheres and the set of symmetric positive-definite matrices further illustrate the efficiency and reliability of the proposed Huber means on Riemannian manifolds.Comment: 72 pages, 9 figure

Differentially Private Multivariate Statistics with an Application to Contingency Table Analysis

Differential privacy (DP) has become a rigorous central concept in privacy protection for the past decade. Among various notions of DP, $f$-DP is an easily interpretable and informative concept that tightly captures privacy level by comparing trade-off functions obtained from the hypothetical test of how well the mechanism recognizes individual information in the dataset. We adopt the Gaussian differential privacy (GDP), a canonical parametric family of $f$-DP. The Gaussian mechanism is a natural and fundamental mechanism that tightly achieves GDP. However, the ordinary multivariate Gaussian mechanism is not optimal with respect to statistical utility. To improve the utility, we develop the rank-deficient and James-Stein Gaussian mechanisms for releasing private multivariate statistics based on the geometry of multivariate Gaussian distribution. We show that our proposals satisfy GDP and dominate the ordinary Gaussian mechanism with respect to $L_2$-cost. We also show that the Laplace mechanism, a prime mechanism in $\varepsilon$-DP framework, is sub-optimal than Gaussian-type mechanisms under the framework of GDP. For a fair comparison, we calibrate the Laplace mechanism to the global sensitivity of the statistic with the exact approach to the trade-off function. We also develop the optimal parameter for the Laplace mechanism when applied to contingency tables. Indeed, we show that the Gaussian-type mechanisms dominate the Laplace mechanism in contingency table analysis. In addition, we apply our findings to propose differentially private $\chi^2$-tests on contingency tables. Numerical results demonstrate that differentially private parametric bootstrap tests control the type I error rates and show higher power than other natural competitors

Cardiogenic shock

Cardiogenic shock is an acute circulatory failure due to compromised myocardial contractility associated with congenital heart diseases and cardiomyopathies, such as myocarditis. In this article, the authors present a 3-step overview of cardiogenic shock diagnosis and management to restore tissue oxygen delivery. The first step is early recognition of nonspecific signs of the shock. The second step is medical management, monitoring, and repeated assessment. In addition to conventional parameters, biomarkers may be useful to monitor the shock. The final step is mechanical circulatory support, such as ventricular assist devices, for children with the refractory shock. We also briefly describe the shock in multisystem inflammatory syndrome in children with coronavirus disease 2019

Association between heart rate variability metrics from a smartwatch and self-reported depression and anxiety symptoms: a four-week longitudinal study

BackgroundElucidating the association between heart rate variability (HRV) metrics obtained through non-invasive methods and mental health symptoms could provide an accessible approach to mental health monitoring. This study explores the correlation between HRV, estimated using photoplethysmography (PPG) signals, and self-reported symptoms of depression and anxiety.MethodsA 4-week longitudinal study was conducted among 47 participants. Time–domain and frequency–domain HRV metrics were derived from PPG signals collected via smartwatches. Mental health symptoms were evaluated using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) at baseline, week 2, and week 4.ResultsAmong the investigated HRV metrics, RMSSD, SDNN, SDSD, LF, and the LF/HF ratio were significantly associated with the PHQ-9 score, although the number of significant correlations was relatively small. Furthermore, only SDNN, SDSD and LF showed significant correlations with the GAD-7 score. All HRV metrics showed negative correlations with self-reported clinical symptoms.ConclusionsOur findings indicate the potential of PPG-derived HRV metrics in monitoring mental health, thereby providing a foundation for further research. Notably, parasympathetically biased HRV metrics showed weaker correlations with depression and anxiety scores. Future studies should validate these findings in clinically diagnosed patients