Hyperledger fabric platform for healthcare trust relations—Proof-of-Concept

In recent years,blockchain technologies have expanded from the finance field to other areas that rely on trustbased solutions.The healthcare industry represents one such area,as digital transformation disrupts relationships between patients,healthcare professionals,and healthcare institutes.Patients and healthcare institutes lack a proficient tool to verify the credentials of medical professionals in a digital environment.Furthermore,healthcare professionals lack a tool where they are in control over their credentials.The first contribution of this paper is a proposal of a solution that leverages the private permissioned Hyperledger Fabric blockchain and smart contracts to provide a source of transparent trust for relationships within the healthcare industry.Second,we pave the ground for GDPR compliance by storing only the hash values on the blockchain.Third,we solve the problem of patient authentication by utilizing cryptographic techniques.Finally,we prove the usability of the proposed solution by implementing a user interface and creating a live deployment.

Preparing for the Nordic Skiing Events at the Beijing Olympics in 2022: Evidence-Based Recommendations and Unanswered Questions

At the 2022 Winter Olympics in Beijing,the XC skiing,biathlon and nordic combined events will be held at altitudes of~1700 m above sea level,possibly in cold environmental conditions and while requiring adjustment to several time zones.However,the ongoing COVID-19 pandemic may lead to sub-optimal preparations.The current commentary provides the following evidence-based recommendations for the Olympic preparations:make sure to have extensive experience of training(>60 days annually)and competition at or above the altitude of competition(~1700 m),to optimize and individualize your strategies for acclimatization and competition.In preparing for the Olympics,10-14 days at~1700 m seems to optimize performance at this altitude effectively.An alternative strategy involves two-three weeks of training at>2000 m,followed by 7-10 days of tapering off at~1700 m.During each of the last 3 or 4 days prior to departure,shift your sleeping and eating schedule by 0.5-1 h towards the time zone in Beijing.In addition,we recommend that you arrive in Beijing one day earlier for each hour change in time zone,followed by appropriate timing of exposure to daylight,meals,social contacts,and naps,in combination with a gradual increase in training load.Optimize your own individual procedures for warming-up,as well as for maintaining body temperature during the period between the warm-up and competition,effective treatment of asthma(if necessary)and pacing at~1700 m with cold ambient temperatures.Although we hope that these recommendations will be helpful in preparing for the Beijing Olympics in 2022,there is a clear need for more solid evidence gained through new sophisticated experiments and observational studies.

Methodological Guidelines Designed to Improve the Quality of Research on Cross-Country Skiing

Cross-country(XC)ski races involve a variety of formats,two different techniques and tracks with highly variable topography and environmental conditions.In addition,XC skiing is a major component of both Nordic combined and biathlon competi-tions.Research in this area,both in the laboratory and field,encounters certain difficulties that may reduce the reliability and validity of the data obtained,as well as complicate comparisons between studies.Here,13 international experts propose specific guidelines designed to enhance the quality of research and publications on XC skiing,as well as on the biathlon and Nordic combined skiing.We consider biomechanical(kinematic,kinetic and neuromuscular)and physiological methodology(at the systemic and/or muscle level),providing recommendations for standardization/control of the experimental setup.We describe the types of measuring equipment and technology that are most suitable in this context.Moreover,we also deal with certain aspects of nomenclature of the classical and skating sub-techniques.In addition to enhancing the quality of stud-ies on XC skiing,Nordic combined and biathlon,our guidelines should also be of value for sport scientists and coaches in other disciplines where physiological and/or biomechanical measurements are performed in the laboratory and/or outdoors.

Pole Length Influences Performance During On-Snow Skating in Female Cross-Country Skiers

Purpose The purpose of this study was to examine the effect of pole length on performance and technique selection during a simulated skating cross-country(XC)skiing competition on snow in female XC skiers.Methods Nine female XC skiers and biathletes(VO2max 63.6±6.2 mL/min/kg,age 22.9±3.5 years,body height 1.69±0.1 m and body mass 60.8±4.6 kg)completed two 5-km skating time-trail with maximal effort.The athletes had a minimum 4.5 h of rest between the two races,which were performed in a random order:one with self-selected poles(89.0%±0.6%of body height)and one with 7.5 cm increased pole length(94.0%±0.5%of body height).Speed in set terrain sections was determined and the selection of sub-technique was self-reported immediately after each race based on a detailed review of the entire track.Results Skiers performed on average 7.1±7.1 s(P=0.029)faster with the long poles,with this difference occurring during the first 200 m and in the uphill parts of the track,in which~5% more G3 and~5% fewer G2 sub-techniques were chosen(both P<0.05).The rating of perceived exertion was 1±0.9 point lower(P=0.04)and skiing technique was perceived to be~1.2±1.5 points better with long poles(P=0.038),while the physiological responses(i.e.,peak and average heart rate,and blood lactate concentration)did not differ between trials.Conclusion In conclusion,poles 7.5 cm longer than self-selected ones improved performance in skating,by enhancing speed in the initial phase(first 200 m)and in the uphill section of the track.In addition,the longer poles induced more use of the G3 skating sub-technique.