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Validity of the VO2 Master Pro device for maximal oxygen consumption prediction and the measurement of resting metabolism
Goldschmidt, Tobiáš ; Nohel, Michal (referee) ; Chlíbková, Daniela (advisor)
Measurements of maximal oxygen uptake and resting metabolic rate are one of the most important things in testing athletes and madical patients. For these measurements are used breath analyzers. These analyzers are usually non-portable costly devices. VO2 Master Pro is on the other hand portable breath analyzer with much lower prize. It is biggest disadvantage is that it contains only O2 sensor and not CO2 sensor as madically aproved devices. Aim of this study is to determinate validity and difference of measurements between VO2 Master Pro and reference device for measuring maximal oxygen uptake and resting metabolic rate. Difference for measuring maximal oxygen uptake was 4,15 ± 4,41 %. For measuring of resting metabolic rate difference was 41,20 ± 11,44 %. For measuring of maximal oxygen uptake is VO2 Master Pro valid but for measuring of resting metabolic rate it is not. It was also confirmed, that size of measured value have non-linear corelation with size of difference in measuring maximal oxygen uptake.
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Retinal S-opsin dominance in Ansell's mole-rats (Fukomys anselli) is a consequence of naturally low serum thyroxine.
MLADĚNKOVÁ, Nella
Mammals usually possess a majority of medium-wavelength sensitive (M-) and a minority of short-wavelength sensitive (S-) opsins in the retina, enabling dichromatic vision. Unexpectedly, subterranean rodents from the genus Fukomys exhibit an S-opsin majority, which is exceptional among mammals, albeit with no apparent adaptive value. Because thyroid hormones (THs) are pivotal for M-opsin expression and metabolic rate regulation, we have, for the first time, manipulated TH levels in the Ansell's mole-rat (Fukomys anselli) using osmotic pumps. In Ansell's mole-rats, the TH thyroxine (T4) is naturally low, likely as an adaptation to the harsh subterranean ecological conditions by keeping resting metabolic rate (RMR) low. We measured gene expression levels in the eye, RMR, and body mass (BM) in TH-treated animals. T4 treatment increased both, S- and M-opsin expression, albeit M-opsin expression at a higher degree. However, this plasticity was only given in animals up to approximately 2.5 years. Mass-specific RMR was not affected following T4 treatment, although BM decreased. Furthermore, the T4 inactivation rate is naturally higher in F. anselli compared to laboratory rodents. This is the first experimental evidence that the S-opsin majority in Ansell's mole-rats is a side effect of low T4, which is downregulated to keep RMR low.
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Validity of the VO2 Master Pro device for maximal oxygen consumption prediction and the measurement of resting metabolism
Goldschmidt, Tobiáš ; Nohel, Michal (referee) ; Chlíbková, Daniela (advisor)
Measurements of maximal oxygen uptake and resting metabolic rate are one of the most important things in testing athletes and madical patients. For these measurements are used breath analyzers. These analyzers are usually non-portable costly devices. VO2 Master Pro is on the other hand portable breath analyzer with much lower prize. It is biggest disadvantage is that it contains only O2 sensor and not CO2 sensor as madically aproved devices. Aim of this study is to determinate validity and difference of measurements between VO2 Master Pro and reference device for measuring maximal oxygen uptake and resting metabolic rate. Difference for measuring maximal oxygen uptake was 4,15 ± 4,41 %. For measuring of resting metabolic rate difference was 41,20 ± 11,44 %. For measuring of maximal oxygen uptake is VO2 Master Pro valid but for measuring of resting metabolic rate it is not. It was also confirmed, that size of measured value have non-linear corelation with size of difference in measuring maximal oxygen uptake.
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Social thermoregulation in the subterranean Mashona mole-rat (\kur{Fukomys darlingi}): the role of socio-physiological effect
WIEDENOVÁ, Pavlína
Life underground is one of the most challenging tasks for animals. The subterranean environment is seasonally and diurnally stable and provides shelter from predators. On the other hand food is scarce, the cost of digging is very high and closed burrows create hypoxic and hypercapnic conditions. Thus the physiological and behavioral adaptations to save energy are very important for underground dwellers. Social thermoregulation is such behavioral adaptation. Additionally, it has been suggested that social animals suffer from ?isolation stress? and that they decrease their metabolic rates when other family members are present = socio-physiological effect. In this study I measured the resting metabolic rates (RMR) of social Mashona mole-rats (Fukomys darlingi) in isolated individuals, pairs and groups of three to eight individuals. Measurements were carried out at two ambient temperatures, in the thermoneutral zone (TNZ; 30°C) to test the presence of a socio-physiological effect and below their TNZ (20°C) to test the effect of social thermoregulation. A socio-physiological effect was distinctive neither in pairs nor in larger groups. At temperature below the TNZ the Mashona mole-rat saved 21% of its energetic expense in pairs due to social thermoregulation. With an increase in group size, energetic savings rose up to four animals. In larger groups, social thermoregulation did not influence the energetic expenditure, possibly because Mashona mole-rat´s families naturally contain around four to five adults.
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