Indirect calorimetry (IC) is a widely used method to study animal energy metabolism by measuring gas exchange. The accuracy of IC depends on detecting variations in signals reflecting the metabolic response, which can be challenging due to measurement noise and external factors. In this study, we propose a methodology to validate IC systems, including an easy-to-use spreadsheet for data computing, to verify accuracy and detect whole-system leaks. We conducted a re-covery test using a simulation of CO2 dynamics in MS Excel and injecting a known CO2 concentration into four respirometry chambers. The clearance rate of CO2 was observed and compared to the expected clearance rate from the simulation. The results from the recovery test in our system show that the proposed methodology is accurate and precise. The proposed methodology and recovery test can be used to standardize the validation of IC systems, providing accurate measurements of animal energy metabolism in different environmental conditions and energy utilization from feeds.

Objective: to analyze the relationships between sociodemographic variables, intolerance to uncertainty (INT), social support and psychological distress (i.e., indicators of Common Mental Disorders [CMDs] and perceived stress [PS]) in Brazilian men during the COVID-19 pandemic. Methods: a cross-sectional study with national coverage, of the web survey type, and conducted with 1,006 Brazilian men during the period of social circulation restriction imposed by the health authorities in Brazil, for suppression of the coronavirus and control of the pandemic. Structural equation modeling analysis was performed. Results: Statistically significant direct effects of race/skin color (λ=0.268; p-value<0.001), socioeconomic status (SES) (λ=0.306; p-value<0.001), household composition (λ=0.281; p-value<0.001), PS (λ=0.513; p-value<0.001) and INT (λ=0.421; p-value<0.001) were evidenced in the occurrence of CMDs. Black-skinned men, with higher SES, living alone and with higher PS and INT levels presented higher prevalence values of CMDs. Conclusions: high levels of PS and INT were the factors that presented the strongest associations with the occurrence of CMDs among the men. It is necessary to implement actions to reduce the stress-generating sources, as well as to promote an increase in resilience and the development of intrinsic reinforcements to deal with uncertain threats.