Evaluation of models to predict the stoichiometry of volatile fatty acid profiles in rumen fluid of lactating Holstein cows

Volatile fatty acids (VFA), produced in the rumen by microbial fermentation, are the main energy source for ruminants. The VFA profile, particularly the nonglucogenic (acetate, Ac; butyrate, Bu) to glucogenic (propionate, Pr) VFA ratio (NGR), is associated with effects on methane production, milk composition, and energy balance. The aim of this study was to evaluate extant rumen VFA stoichiometry models for their ability to predict in vivo VFA molar proportions. The models were evaluated using an independent data set consisting of 101 treatments from 24 peer-reviewed publications with lactating Holstein cows. All publications contained a full diet description, rumen pH, and rumen VFA molar proportions. Stoichiometric models were evaluated based on root mean squared prediction error (RMSPE) and concordance correlation coefficient (CCC) analysis. Of all models evaluated, the 1998 Friggens model had the lowest RMSPE for Ac and Bu (7.2 and 20.2% of observed mean, respectively). The 2006 Bannink model had the lowest RMSPE and highest CCC for Pr (14.4% and 0.70, respectively). The 2008 Bannink model had comparable predictive performance for Pr to that of the 2006 Bannink model but a larger error due to overall bias (26.2% of MSPE). The 1982 Murphy model provided the poorest prediction of Bu, with the highest RMSPE and lowest CCC (24.6% and 0.15, respectively). The 1988 Argyle and Baldwin model had the highest CCC for Ac with an intermediate RMSPE (0.47 and 8.0%, respectively). The 2006 Sveinbjörnsson model had the highest RMSPE (13.9 and 34.0%, respectively) and lowest CCC (0.31 and 0.40, respectively) for Ac and Pr. The NGR predictions had the lowest RMSPE and highest CCC in the 2 models of Bannink, whereas the lowest predictive performance was in the 2006 Sveinbjörnsson model. It appears that the type of VFA produced is not a simple linear relationship between substrate inputs and pH as currently represented. The analysis demonstrates that most rumen VFA stoichiometric approaches explain a large part of the variation in VFA molar proportions among diets, in particular for Ac, whereas predictive power for Pr and Bu differ largely among approaches. The move toward feed evaluation systems based on animal response might necessitate an improved representation of rumen fermentation, focused on improving our understanding of VFA proportions in diets that vary from the mean

Judo ukemis: a tool for protecting the health and quality of life of children. Safe fall-safe school

Postprint (author's final draft

Analysing the body pressure mapping during the Ushiro Ukemi fall technique by means of an e-textile sensor array.

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024) Judo, often referred to as the "gentle way," is an Olympic and Paralympic sport founded by Jigoro Kano in the late 19th century, draws inspiration from traditional Japanese martial arts, practised in over 200 countries worldwide. Thissport has captivated practitioners and enthusiasts worldwide for over a century. The purpose of Judo is not to inflict harm on an opponent but rather to use an opponent's energy and force against them in order to throw him. Therefore, one of the key elements that set Judo is the emphasis on safe falling techniques (Ukemis). Ukemi is a fundamental component of Judo training, teaching practitioners how to land safely when thrown is mandatory. These techniques not only protect the Judoka from injury but also facilitate a seamless transition between defence and offence. In order to do a safe fall, some requirements must be fulfilled; Keep the head under control and close to the chin, flex legs to lower body gravity centre, arched back and hit with the hand on the ground with stretched elbows during landing. The aim of this work is to experimentally validate the functionality of an e-textile pressure sensor array to be used to analyse the Judo fall techniques.  </p