Matryoshka Inspired Statistical Surrogate for Turbulent Mixing

Thermalhydraulics of reactor plena is often the most challenging problem due to turbulent mixing, role of jets and stratified flows. Due to which, the safety analysis of the overall reactor vessel or reactor system become complex. Inability of the system level analysis codes to accurately model the role of tur- bulent mixing in scalar transport leads to a major source of uncertainties. The computational cost of accurate CFD models renders the sensitivity studies using those for reactor safety ineffective. Reduced order models are needed which can effectively capture the effects of turbulent mixing and can be used for parametric studies important for safety analysis. Turbulent flows compose of many energetic scales which are hidden inside one another in a ‘Matryoshka’ like fashion and exhibit non-trivial interactions. These multi-scale interactions can be accurately captured by Direct Numerical Simulations (DNS) of Navier Stokes equations or high fidelity experimental data. Hence, if a data learning model can be trained to capture the energetic interactions it can serve as a statistical surrogate. For this study, DNS data for a channel flow problem is used to obtain statistical surrogates. A lagrangian description of the field is developed by removing the long time correlations or the fine scale structures of the turbulent system. To obtain this, Kramers-Moyal analysis [1, 2] of the measured time series was performed and parameters of the Itô’s equation (or the Eulerian Fokker-Planck equation) were calculated directly from the data. This data driven coarse-grained stochastic differential equation surrogate of the turbulent system which can be coupled to the Lagrangian- Lagrangian type of simulations for the transport of passive scalar quantity. References [1] R. Friedrich and J. Peinke, “Description of a turbulent cascade by a fokker- planck equation,” Physical Review Letters, vol. 78, no. 5, p. 863, 1997. [2] H. Risken, “Fokker-planck equation,” in The Fokker-Planck Equation, pp. 63–95, Springer, 1996

Stratification and Mixing in the Hot Plena of Liquid Metal-Cooled Reactors

Understanding or modeling the role of stratification and mixing in the plena or containments of nuclear reactors is of prime significance to their safety analysis. Particularly, in case of liquid metal-cooled reactors, thermal stratification in the hot pools under off-normal transients is one of the least understood problems that have multi-physics effects on thermo- mechanics and reactor physics. This is primarily due to lack of high fidelity experimental data for validating CFD or system scale models, which are essential for improved understanding. A scaled liquid metal thermal-hydraulic facility with a scaled hot plenum has been developed at Kansas State University to study different transients. Experimental results obtained from Rayleigh Backscattering based Swept Wavelength Interferometry and Acoustic Backscattering instrumentation deployed in the liquid metal loop will be presented in this talk. Critical parametric estimates such as critical Rayleigh number and turbulent Prandtl number are identified from the experimental studies to classify the molecular, transitional and energetic regimes of mixing extent. CFD codes using direct numerical simulations (DNS) or large eddy simulations (LES) have potential to be able to capture the physics of stratification or mixing with accuracy. However, it is well known that these approaches are computationally intensive and can not be used for sensitivity studies for design or safety analysis. On the other hand, system scale codes model the large enclosures such as containments or plena with the help of perfect mixing or1D coarse grained scalar transport. This talk will present the transient scenarios and demonstrate the performance of different models against experimental data

A sporting chance

No abstract available.For the IOC Mental Health in Elite Athletes Toolkit see https://stillmed.olympics.com/media/Document%20Library/IOC/Athletes/Safe-Sport-Initiatives/IOC-Mental-Health-In-Elite-Athletes-Toolkit-2021.pdfhttp://www.thelancet.com/psychiatryhj2021Sports Medicin

Minds matter : how COVID-19 highlighted a growing need to protect and promote athlete mental health

The Sports and Exercise Medicine community and other sport stakeholders are becoming increasingly aware of the mental health symptoms (eg, depression, anxiety, substance misuse) reported by athletes. In 2019, this led to the publication of the first International Olympic Committee (IOC) consensus statement on mental health in this cohort and the establishment of the IOC Mental Health Working Group.1 Over the past 2 years, the COVID-19 pandemic and related public health measures have presented additional challenges to the well-being of all populations, including athletes. This editorial reflects on how the COVID-19 pandemic has highlighted a growing need to protect and promote athlete mental health.http://bjsm.bmj.comhj2022Sports Medicin

Mental health management of elite athletes during COVID-19: a narrative review and recommendations.

Elite athletes suffer many mental health symptoms and disorders at rates equivalent to or exceeding those of the general population. COVID-19 has created new strains on elite athletes, thus potentially increasing their vulnerability to mental health symptoms. This manuscript serves as a narrative review of the impact of the pandemic on management of those symptoms in elite athletes and ensuing recommendations to guide that management. It specifically addresses psychotherapy, pharmacotherapy and higher levels of care. Within the realm of psychotherapy, crisis counselling might be indicated. Individual, couple/family and group psychotherapy modalities all may be helpful during the pandemic, with novel content and means of delivery. Regarding pharmacotherapy for mental health symptoms and disorders, some important aspects of management have changed during the pandemic, particularly for certain classes of medication including stimulants, medications for bipolar and psychotic disorders, antidepressants and medications for substance use disorders. Providers must consider when in-person management (eg, for physical examination, laboratory testing) or higher levels of care (eg, for crisis stabilisation) is necessary, despite potential risk of viral exposure during the pandemic. Management ultimately should continue to follow general principles of quality health care with some flexibility. Finally, the current pandemic provides an important opportunity for research on new methods of providing mental health care for athletes, and consideration for whether these new methods should extend beyond the pandemic. [Abstract copyright: © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.

International Olympic Committee consensus statement: Methods for recording and reporting of epidemiological data on injury and illness in sport 2020 (including STROBE Extension for Sport Injury and Illness Surveillance (STROBE-SIIS))

Injury and illness surveillance, and epidemiological studies, are fundamental elements of concerted efforts to protect the health of the athlete. To encourage consistency in the definitions and methodology used, and to enable data across studies to be compared, research groups have published 11 sport-specific or setting-specific consensus statements on sports injury (and, eventually, illness) epidemiology to date. Our objective was to further strengthen consistency in data collection, injury definitions and research reporting through an updated set of recommendations for sports injury and illness studies, including a new Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist extension. The IOC invited a working group of international experts to review relevant literature and provide recommendations. The procedure included an open online survey, several stages of text drafting and consultation by working groups and a 3-day consensus meeting in October 2019. This statement includes recommendations for data collection and research reporting covering key components: defining and classifying health problems; severity of health problems; capturing and reporting athlete exposure; expressing risk; burden of health problems; study population characteristics and data collection methods. Based on these, we also developed a new reporting guideline as a STROBE Extension -the STROBE Sports Injury and Illness Surveillance (STROBE-SIIS). The IOC encourages ongoing in-and out-of-competition surveillance programmes and studies to describe injury and illness trends and patterns, understand their causes and develop measures to protect the health of the athlete. Implementation of the methods outlined in this statement will advance consistency in data collection and research reporting. © Author(s) (or their employer(s)) 2020

Mental health in elite athletes: International Olympic Committee consensus statement (2019)

Mental health symptoms and disorders are common among elite athletes, may have sport related manifestations within this population and impair performance. Mental health cannot be separated from physical health, as evidenced by mental health symptoms and disorders increasing the risk of physical injury and delaying subsequent recovery. There are no evidence or consensus based guidelines for diagnosis and management of mental health symptoms and disorders in elite athletes. Diagnosis must differentiate character traits particular to elite athletes from psychosocial maladaptations. Management strategies should address all contributors to mental health symptoms and consider biopsychosocial factors relevant to athletes to maximise benefit and minimise harm. Management must involve both treatment of affected individual athletes and optimising environments in which all elite athletes train and compete. To advance a more standardised, evidence based approach to mental health symptoms and disorders in elite athletes, an International Olympic Committee Consensus Work Group critically evaluated the current state of science and provided recommendations

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely