Fitting the Reproduction number from UK coronavirus case data, and why it is close to 1

We present a method for rapid calculation of coronavirus growth rates and R-numbers tailored to the publicly available data in the UK. The R-number is derived from time-series of case data, using bespoke data processing to remove systematic and errors and stochastic fluctuations. In principle, growth rate can be obtained by differentiating the reported case numbers, but in fact daily stochastic fluctuations disqualify this method. We therefore assume that the case data comprises a smooth, underlying trend which is differentiable and a noise term. The approach produces, up-to-date estimates of the R-number throughout the period of data availability. Our method is validated against published consensus R-numbers from the UK government, and shown to produce comparable results. A significant advantage of our method is that it is stable up to the most recent data, this enables us to make R-number estimates available over two weeks ahead of the published consensus. The short-lived peaks observed in the R-number and case data cannot be explained by a well-mixed model and are suggestive of spread on a localised network. Such a localised spread model tends to give an Rt number close to 1, regardless of how large R0. The case-driven approach is combined with Weight-Shift-Scale (WSS) methods to monitor trends in the epidemic and for medium term predictions. Using case-fatality ratios, we create a narrative for trends in the UK epidemic increased infectiousness of the alpha and delta variants, and the effectiveness of vaccination in reducing severity of infection.

CHARACTERISTICS OF THE COORDINATED MOTOR RESPONSE AND VOLUNTARY SHIFT OF THE CENTER OF GRAVITY IN WOMEN AGED 85-95

Цель работы - установить возрастные особенности скоординированных моторных реакций и целенаправленного движения центра тяжести (ЦТ) у женщин 85-95 лет. Были обследованы 68 женщин 85-95 лет (средний возраст - 89,3±3 года), которых разделили на две возрастные группы: 1-я - 37 женщин 85-89 лет (средний возраст - 86,9±1,6 года); 2-я - 31 женщина 90-95 лет (средний возраст - 92,1±1,4 года). Для реализации поставленной цели использовали компьютерный динамический постурографический (стабилометрический) комплекс «Smart Equitest Balance Manager» (США). Проводили следующие тесты: Motor Control Test (MCT) и тест Rhythmic Weight Shift (RWS). У большинства обследованных женщин 90-95 лет выявлено снижение композитной оценки латентности всего MCT (Composite of all Latencies), p=0,009. При этом сравнительный анализ теста RWS не выявил статистически значимых различий между возрастными группами. Установлены причинно-следственные связи показателей теста RWS и уровня возрастной самооценки. У женщин 90-95 лет не наблюдали снижения скорости целенаправленного движения и эффективного управления ЦТ во фронтальном и сагиттальном направлениях, при этом латентность скоординированных моторных реакций характеризовалась достоверно низкими значениями по сравнению с женщинами 85-89 лет. Таким образом, у женщин после 89 лет не происходит возрастных изменений процесса сенсомоторной интеграции, что также можно рассматривать как предиктор долгожительства. Полученные результаты позволили обозначить параметры MCT и теста RWS, которые можно учитывать при прогнозировании постуральных изменений и продолжительности жизни у женщин в старческом возрасте. The objective of this study was to identify the age-related peculiarities of the coordinated motor response and voluntary shift of the center of gravity (COG) in females aged 85-95. A total of 68 women within the age range of 85-95 were screened, mean age (М±SD) - 89,3±3. The first group comprised 37 women between the chronological ages of 85 and 89 (mean age: 86,9±1,6). The second group included 31 women aged 90-95 (mean age: 92,1±1,4). To achieve the stated objective the computer dynamic posturographic complex Smart Equitest Balance Manager (USA) was used. The following tests were conducted: Motor Control Test (MCT), Rhythmic Weight Shift Test (RWS). The tests revealed a decreasing Composite of all Latencies (p=0,009) in the majority of the surveyed women aged 90-95. However, a comparative analysis of the RWS test results showed no statistically significant differences between the age groups. Cause and effect relationships between the RWS test results and subjective perception of aging were established. Women aged 90-95 demonstrated no decrease in the speed of the voluntary shift and effective control of COG in frontal and sagittal planes, whereas the latency of their coordinated motor response was marked by reliably low numbers compared to women aged 85-89. Thus, women after 89 experience no age-related alterations in sensorimotor integration, which could be regarded as a predictor of longevity. The results obtained made it possible to outline the MCT and RWS parameters which can be taken into consideration in forecasting postural alterations and life expectancy for older women.

Anticipatory weight shift between arms when reaching from a crouched posture

Reaching movements performed from a crouched body posture require a shift of body weight from both arms to one arm. This situation has remained unexamined despite the analogous load requirements during step initiation and the many studies of reaching from a seated or standing posture. To determine whether the body weight shift involves anticipatory or exclusively reactive control we obtained force plate records, hand kinematics, and arm muscle activity from 11 healthy right-handed participants. They performed reaching movements with their left and right arm in two speed contexts - 'comfortable' and 'as fast as possible' - and two postural contexts - a less stable knees-together posture and more stable knees-apart posture. Weight-shifts involved anticipatory postural actions (APA) by the reaching and stance arms that were opposing in the vertical axis and aligned in the side-to-side axis similar to APAs by the legs for step initiation. Weight-shift APAs were correlated in time and magnitude, present in both speed contexts, more vigorous with the knees placed together, and similar when reaching with the dominant or non-dominant arm. The initial weight-shift was preceded by bursts of muscle activity in the shoulder and elbow extensors (posterior deltoid and triceps lateral) of the reach arm and shoulder flexor (pectoralis major) of the stance arm which indicates their causal role; leg muscles may have indirectly contributed but were not recorded. The strong functional similarity of weight-shift APAs during crouched reaching to human stepping and cats reaching suggests that they are a core feature of posture-movement coordination.

Effect of Smartphone Use on Static and Dynamic Postural Balance in Healthy Young Adults

Purpose The purpose of this study was to investigate the possible effects of smartphone usage in the biomechanical balance system. Method Twenty-five healthy young adults (10 men, 15 women) between the ages of 18 and 25 years without balance problems were included in the study. Sensory organization, adaptation, rhythmic weight shift, and functional limitation tests (unilateral stance, sit to stand, walk across, tandem walk, step quick turn, step up down, forward lunge) have been applied. Results Significant results were obtained in parameters of sensory organization, tandem walk, walk across, and unilateral stance tests ( p < .05). Conclusion The effects of using smartphones on postural control and balance in different circumstances, such as standing and walking, must be comprehensively determined to prevent accident.

Fall Patterns Are Independent Risk Factors for Mortality After Hip Fracture in Older Adults

Hip fracture is becoming a major health problem with high mortality and morbidity in older adults. However, whether specific fall patterns could act as independent risk factors for predicting mortality after hip fracture remains unknown. We aimed to investigate whether fall patterns can serve as an independent risk factor for mortality after hip fracture. Electronic medical records (EMR) of individuals who visited emergency room or admitted to the Severance hospital, Seoul, Korea, between January 2005 to December 2019 were reviewed to categorize fall patterns. Fall patterns were categorized upon review of explanatory description in EMR, using modified classification based on motion analysis of video-captured falls in a prior study. Among 1,991 study subjects (mean age 77 years, 71% women), 211 patients died (10.6%; median survival 296 days). Fall location was divided into home (67.4%) and outdoor (32.6%) with mortality rate of 11.9% and 8.0% (p=0.009), respectively. Fall patterns were specified by “cause of fall” (6 categories; slip [29.6%], trip or stumble [17.5%], etc.) and by “activity at time of fall” (6 categories; walking [54.8%], getting up or rising [14.1%], etc). Among the combinations of both causes and activities, individuals who sustained hip fracture during “incorrect weight shift while sitting down or lowering”(hazard ratio [HR] 3.35, p=0.003), “collapsed during unclassified activity”(HR 2.37, p=0.006), “incorrect weight shift while getting up or rising”(HR 2.13, p=0.003), and “slipped while walking”(HR 1.83, p=0.004) had increased mortality after hip fracture compared to those with outdoor falls, after adjustment for age, sex, and Charlson comorbidity index. Specific fall patterns in individuals who sustained hip fracture predicted excess mortality in older adults, independent of age, sex, and comorbidities. Acknowledgement: We thank Doori Cho of the the SENTINEL (Severance ENdocrinology daTa scIeNcE pLatform) team (4-2018-1215) for the data acquisition process. Conflict of Interest: SB, NH, and YR have nothing to declare.