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To evaluate various influencing factors of rumination time (RT) variation in Holstein cattle in China, data from 38 consecutive months from 864 lactating cows using three-axis accelerometer based wearable neck sensors were collected. Year, season, parity, THI, bihourly rumination time in minutes (R2h), and days in milk (DIM) had a significant effect on the diurnal rhythm of rumination. The average daily rumination time in minutes (DRT) was 527, increased in spring (550), and declined in summer (514). A prenatal decline in DRT from 557 at −18DIM to 344 at DIM0 and its gradual rise (597) on DIM4, gave valuable insights regarding periparturient management. A stable return of DRT was observed by DIM30, later rumination time gradually decreased with increasing DIM. From 22:00 to 04:00 the R2h was higher and had a strong correlation (0.45) with DRT. Milking and feeding time drop in R2h pattern, though significant (P < 0.05), was consistent between concerning parity and season. The average DRT of the first parity cows was lower (29 min/d) than multiparous cows, while this difference was greater (47 min d−1) in summer. DRT reached the highest daily average upon THI63–65, decreased gradually in winter, and touched the lowest during extreme summer. A chronological influencing concomitance of THI63 and THI68 with the RT of dairy cows provided valuable insights into THI thresholds for RT decline and heat stress. RT was maximum at THI63, while higher the duration spent above the THI thresholds of 68 and 72, more pronounced was the RT decline. • Three-axis accelerometer-based wearable reliably predicts the rumination behaviour. • Daily rumination time (DRT) is lower in summer months, cooling measures helps. • DRT of primiparous dairy cows is higher than multiparous cows. • DRT decline sharply around parturition and rise back to maximum at day 4. • DRT is highest at THI 63–65, decrease at THI 68 and declines markedly after THI 72. [ABSTRACT FROM AUTHOR]

The article presents a study on fractal and linear heart rate dynamics during sleep and at high altitudes. It states that the study involves electrocardiogram (ECG) monitoring of subjects at high altitude levels in Mount Everest. Results show that cardiac response during sleep at high altitudes can hardly be explored through heart rate variability (HRV) estimation. It also suggests supporting results with more sophisticated fractal and nonlinear cardiac variability features.

• Environmental exposures were assessed for adults (aged 60–69) monthly for 5 months. • Passive sampler wristbands detected personal exposures to 70 airborne chemicals. • Distinct mixtures of chemical exposures were identified across seasons. • Individuals formed distinct exposure clusters based on trajectories across seasons. • Phthalate personal exposures were positively correlated with outdoor temperatures. The health impact of airborne contaminants has been challenging to assess due to current limitations in measurement technologies. The emergence of wearable passive samplers coupled with high resolution mass spectrometry (HR-MS) chemical analysis has enabled comprehensive characterization of personal exposures. We conducted a repeated-measure study among 84 older adults in Jinan, China, as part of the Biomarkers for Air Pollutants Exposure (China BAPE) study. Study objectives were: 1) to characterize the occurrence, magnitude, and distribution of personal exposure to airborne contaminants; 2) to evaluate the temporal variation of chemical exposures across the study population; and 3) to identify behavioral and environmental factors that influence the observed variance in chemical exposures. The FreshAir wristband was worn by participants for three consecutive days each month from September 2018 to January 2019 and collected with paired time-activity logs. Passive air samplers were also deployed in parallel at a local outdoor air monitoring station. Spearman's Rho trend test and trajectory cluster analysis were used to identify exposure trends and variation patterns, respectively. Out of the 70 airborne compounds of potential concern screened, 26 compounds from 10 chemical classes were found to be above detection thresholds across >70% of the study population. Personal exposures were predominantly characterized by nine polycyclic aromatic hydrocarbons (PAHs), four phthalates, three nitroaromatics, and two volatile organic compounds (VOCs). Phthalate personal exposures were positively correlated with outdoor temperatures while the inverse relationship was observed for certain PAHs (p < 0.05). Specifically, dimethyl phthalate (r s = 0.31) decreased as temperatures declined, while nitrobenzene (r s = −0.35) and naphthalene (r s = −0.40) increased as temperatures decreased. Compared to levels measured at the outdoor air monitoring site, personal exposure of phthalates was elevated (p < 0.05) and hexachlorobutadiene was lower across participants (p < 0.01). Personal exposure of these chemicals was further found to be weakly associated with daily duration participants spent outdoors. Individuals formed distinct clusters based on trajectories of chemical exposures across the sampling period (September to January), potentially suggestive of distinct emission sources. In conclusion, we demonstrate the feasibility of characterizing the occurrence and magnitude of personal exposure to airborne chemical contaminants using passive wristband samplers. The temporal variability of these personal exposure profiles was highlighted and with distinct trends identified across different groups of individuals. Future studies will integrate this data with other omics datasets collected from this population of Chinese older adults to investigate associations between exposure profiles and health relevant biomarkers, to provide evidence in feasibility of disease prevention through environmental improvements. [ABSTRACT FROM AUTHOR]