We report the controlled injection of near-isolated micron-sized liquid droplets into a low temperature He-Ne steady-state rf plasma at atmospheric pressure. The H 2 O droplet stream is constrained within a 2 mm diameter quartz tube. Imaging at the tube exit indicates a log-normal droplet size distribution with an initial count mean diameter of 15 m falling to 13 m with plasma exposure. The radial velocity profile is approximately parabolic indicating near laminar flow conditions with the majority of droplets travelling at > 75% of the local gas speed and having a plasma transit time of < 100 s. The maximum gas temperature, determined from nitrogen spectral lines, was below 400 K and the observed droplet size reduction implies additional factors beyond standard evaporation, including charge and surface chemistry effects. The successful demonstration of controlled microdroplet streams opens up possibilities for gas-phase microreactors and remote delivery of active species for plasma medicine.
Background:Eventing is an equestrian sport that tests athletes' and horses' skill over three phases: dressage, jumping and cross-country. Falls during the cross-country phase can have very serious outcomes up to and including death for both horse and athlete. Therefore, understanding risk factors associated with falls is essential for improving equine and human welfare.Objectives: To provide descriptive statistics and identify risk factors at the horse-, athlete-and course-level affecting horses competing in Fédération Equestre Internationale (FEI) events worldwide.
Study design: Retrospective cohort study.Methods: Data collected by the FEI of every horse start worldwide in all international (CI), championship (CH), Olympics (OG) and World Equestrian Games (WEG) competitions between January 2008 and December 2018 were analysed. Descriptive statistics followed by univariable logistic regression to identify risk factor candidates for inclusion in the final multivariable logistic regression model. Models were constructed stepwise using a bi-directional process and assessed using the Akaike information criterion.Results: Factors associated with increased risk of falls and or unseated rider included: higher event levels, longer course distances, more starters at cross-country phase and less experienced horses and athletes.
Main limitations:The data set is geographically comprehensive but covers only FEI competitions, not National Federation events, that is not every competition started by every individual horse. Nor does the data set include any prior veterinary information or data on training or schooling. Conclusions: This is the first large-scale epidemiological study of cross-country falls in FEI eventing. Results suggest that a potential risk profile can be constructed for each horse-athlete combination prior to entering a given competition, based on individual histories and course-level factors. This could lead to interventions that can reduce the number of falls, thus protecting equine and human welfare.
An epidemiological study of elite endurance riding was conducted using data from every Fédération Equestre Internationale (FEI) endurance event from 2010 to 2015, comprising 82,917 starts. The aim of the study was to identify risk factors associated with failure to qualify outcomes for horses during FEI endurance rides. The FEI endurance rules state that, during a ride, horses must be assessed by veterinarians several times, giving veterinarians the opportunity to prevent those horses exhibiting signs of lameness or metabolic problems from continuing further. Multivariable logistic regression models were constructed to identify horse, ride and rider level risk factors associated with failure to qualify. Risk factors particularly associated with increased likelihood of failure to qualify due to lameness included age of horse≥9 years, male horse, male rider, field size≥61 horses and if the ride was held in region group II (Northern and Eastern Europe). Factors associated with increased likelihood of failure to qualify due to metabolic problems included whether the ride was held in region group VII (North Africa and the Middle East), ride distance≥100km and male rider. Some risk factors, such as field size, may be modifiable at the ride level. Other risk factors such as horse age or sex are unmodifiable, but awareness of the risk contributed by these factors can provide veterinarians with additional information while treating horses during endurance rides.
This study examined the association between riding speed and elimination in Fédération Equestre Internationale (FEI) endurance events. A total of 35,061 horse starts from 1st July 2012 to 31st December 2015 were included in a multivariable logistic regression model containing 25 different risk factors. Riding speeds in individual stages ('loops') were included as individual risk factors in studying the progress of horses through loops 1-3 of each endurance ride. The possibility of real-time, 'mid-ride' predictive modelling was explored by modelling both riding speeds and sudden changes in speed between loops as potential risk factors. Faster riding speeds, especially during loops 1 and 2, were associated with deleterious outcomes. Furthermore, sudden drops in riding speed during loop 3 were associated with an increased likelihood of elimination.
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