scholarly journals EXTERNAL AND INTERNAL BODY TEMPERATURE OF THE COMMON ADDER

Author(s):  
N. D. Ganyushina ◽  
◽  
A. V. Korosov ◽  
N. A. Litvinov ◽  
N. A. Chetanov ◽  
...  
Author(s):  
Jane I Khudyakov ◽  
Michael D Treat ◽  
Mikayla C Shanafelt ◽  
Jared S Deyarmin ◽  
Benjamin A Neely ◽  
...  

Many mammals use adaptive heterothermy (e.g. torpor, hibernation) to reduce metabolic demands of maintaining high body temperature (Tb). Torpor is typically characterized by coordinated declines in Tb and metabolic rate (MR) followed by active rewarming. Most hibernators experience periods of euthermy between bouts of torpor during which homeostatic processes are restored. In contrast, the common tenrec, a basoendothermic Afrotherian mammal, hibernates without interbout arousals and displays extreme flexibility in Tb and MR. We investigated the molecular basis of this plasticity in tenrecs by profiling the liver proteome of animals that were active or torpid with high and more stable Tb (~32°C) or lower Tb (~14°C). We identified 768 tenrec liver proteins, of which 50.9% were differentially abundant between torpid and active animals. Protein abundance was significantly more variable in active cold and torpid compared to active warm animals, suggesting poor control of proteome abundance. Our data suggest that torpor in tenrecs may lead to mismatches in protein pools due to poor coordination of anabolic and catabolic processes. We propose that the evolution of endothermy leading to a more realized homeothermy of boreoeutherians likely led to greater coordination of homeostatic processes and reduced mismatches in thermal sensitivities of metabolic pathways.


2018 ◽  
Vol 42 (2) ◽  
pp. 328-337 ◽  
Author(s):  
Andrew M. Herberg ◽  
Véronique St-Louis ◽  
Michelle Carstensen ◽  
John Fieberg ◽  
Daniel P. Thompson ◽  
...  

Author(s):  
Richard T. Meyer ◽  
Bin Yao

Previous research has assumed that a perfect Proton Exchange Membrane Fuel Cell (PEMFC) body temperature manager is available. Maintaining this temperature at a desired value can ensure a high reaction efficiency over all operation. However, fuel cell internal body temperature control has not been specifically presented so far. This work presents such control, using a Multiple Input Single Output (MISO) fuel cell cooling system to regulate the internal body temperature of a PEMFC intended for transportation. The cooling system plant is taken from a recently developed hydrogen/air PEMFC total system model. It is linearized and used to design a series of controllers via μ-synthesis. μ-synthesis is chosen since system nonlinearities can be handled as parameter uncertainties. A controller must coordinate the desired fuel cell internal temperature and commanded mass flow rates of the coolant and cooling air. Each linear controller is created for a segment of the expected current density range. Plant parameters are expected to vary over their linearized values in each segment. Also, a common set of μ-synthesis weighting functions has been developed to ease controller design at different operating points. Thus, the nonlinear cooling subsystem can be controlled with a series of current density scheduled linear controllers. Current density step change simulations are presented to compare the controller closed loop performance and open loop response which uses cooling system flow rates taken from an optimal steady state solution of the whole fuel cell system. Furthermore, a closed loop sinusoid response is also given. These show that the closed loop driven internal fuel cell temperature will vary little during operation. However, this will only be true over the range that the cooling system is required to be active.


2018 ◽  
Vol 1 (1) ◽  
pp. 65-74
Author(s):  
Tomaz Martini ◽  
Jürgen Ripperger ◽  
Urs Albrecht

The interplay between the circadian system and metabolism may give animals an evolutionary advantage by allowing them to anticipate food availability at specific times of the day. Physiological adaptation to feeding time allows investigation of animal parameters and comparison of food anticipation between groups of animals with genetic alterations and/or post pharmacological intervention. Such an approach is vital for understanding gene function and mechanisms underlying the temporal patterns of both food anticipation and feeding. Exploring these mechanisms will allow better understanding of metabolic disorders and might reveal potential new targets for pharmacological intervention. Changes that can be easily monitored and that represent food anticipation on the level of the whole organism are a temporarily restricted increase of activity and internal body temperature.


2016 ◽  
Vol 283 (1839) ◽  
pp. 20161551 ◽  
Author(s):  
Glenn J. Tattersall ◽  
Damien Roussel ◽  
Yann Voituron ◽  
Loïc Teulier

This study aimed to examine thermoregulatory responses in birds facing two commonly experienced stressors, cold and fasting. Logging devices allowing long-term and precise access to internal body temperature were placed within the gizzards of ducklings acclimated to cold (CA) (5°C) or thermoneutrality (TN) (25°C). The animals were then examined under three equal 4-day periods: ad libitum feeding, fasting and re-feeding. Through the analysis of daily as well as short-term, or ultradian, variations of body temperature, we showed that while ducklings at TN show only a modest decline in daily thermoregulatory parameters when fasted, they exhibit reduced surface temperatures from key sites of vascular heat exchange during fasting. The CA birds, on the other hand, significantly reduced their short-term variations of body temperature while increasing long-term variability when fasting. This phenomenon would allow the CA birds to reduce the energetic cost of body temperature maintenance under fasting. By analysing ultradian regulation of body temperature, we describe a means by which an endotherm appears to lower thermoregulatory costs in response to the combined stressors of cold and fasting.


2021 ◽  
Vol 325 (1) ◽  
pp. 99-112
Author(s):  
N.D. Ganyushina ◽  
A.V. Korosov

The results of processing the data of continuous recording of body temperature using loggers obtained with the enclosure keeping 23 individuals of the common viper Vipera berus L. in Karelia (62.068310°N, 33.958824°E) are presented. Nine temperature characteristics, subdivided into 2 groups, were quantitatively evaluated – thermoecological, describing the dependence of the course of the viper’s body temperatures on the heat flux of the medium, and thermophysiological, stable parameters of thermoregulation. The factors that determine the variability of temperature characteristics are considered: time of day, weather conditions, morphometric indicators of an individual. A wide individual variability of thermoecological indicators and low variability of thermophysiological indicators were revealed, which was not associated with significant differences in different individuals. The parameter “maximum voluntary temperature”, which characterizes body temperature while avoiding overheating, is the closest to the physiological parameter of thermoregulation; obtaining such data is a very laborious process associated with deciphering the snake’s behavior from video recordings. An indicator that gives close values to the maximum voluntary temperature, which has a very simple calculation algorithm – “median active temperature (for a sample of temperatures above 30°C)”; however, it requires a volumetric series of continuously recorded temperature records for analysis. An accurate, statistically robust “maximum typical temperature” parameter gives an idea of the true maximum temperature characteristic of a species, but has a complex calculation method. These thermophysiological parameters are recommended to be used for intrapopulation and interspecies comparisons.


2020 ◽  
Vol 13 (5) ◽  
pp. 264-274
Author(s):  
Р.В. Клейманов ◽  
С.Е. Александров

Авторами статьи предлагается высокопроизводительное устройство для подачи жидкого реагента в установку для химического осаждения высокочистого кварца в пламени. Подача жидкого кремнийсодержащего реагента осуществляется путем преобразования его в аэрозоль при помощи аэродинамического распылителя с плоским соплом Лаваля с внутренним телом. Разработанная конструкция позволяет достичь больших расходов жидкого реагента путем изменения сечений сопла для регулировки скорости газа-распылителя. Предложенная конструкция отличается более высокой технологичностью и простотой изменения расхода реагента в широких пределах, в отличие от распространенных коаксиальных конструкций сопел. The authors propose a high-performance device for supplying a liquid reagent for the chemical vapor deposition of high-purity quartz. The liquid silicon-containing reagent is supplied by converting it into an aerosol using an aerodynamic nebulizer with a flat Laval nozzle incorporating an internal body. The developed design allows of achieving a high flow rate of the liquid reagent by changing the nozzle cross-sections so as to adjust the speed of the nebulizer gas. The proposed design features higher manufacturability and simple adjustment of the reagent flow rate over a wide range, as distinct from the common coaxial nozzle designs.


2020 ◽  
Vol 16 (3) ◽  
pp. 55-65
Author(s):  
Iwona Janczarek ◽  
Izabela Wilk ◽  
Anna Wiśniewska ◽  
Roland Kusy ◽  
Katarzyna Cikacz ◽  
...  

The aim of the study was to analyse selected air parameters in a stable (microclimate) and the basic physiological parameters of horses housed in the stable in different seasons of the year. The research material was 12 adult hot-blooded horses kept in a brick stable with stalls. Air parameters in the stable (temperature in the passageway, temperature in the stall at two points, relative humidity in the passageway, and relative humidity in the stall at two points) were determined four times in one year, in summer, autumn, winter and spring. Measurements were made with a Bluetooth BLE-LOGGER LB-518 battery-operated cordless thermo-hygrometer at 12 noon at five points in the stable located 300 cm apart. Physiological parameters of the horses, i.e. internal body temperature (Veterinär SC 12 veterinary thermometer), heart rate (Polar ELECTRO OY RS800CX with PolarProTrainer 5.0. software), and respiratory rate (with a manual stopwatch) were measured at 6 a.m. and 6 p.m. on each day of the study. The season of the year was found to have a significant influence on the microclimate of the stable. To ensure optimal air humidity, airing of the stable should be limited only in winter and periodically in autumn. It is also worth emphasizing that the stable microclimate has a marked effect on the basic physiological parameters of horses. High temperature and relative humidity in the stable can cause unfavourable changes in the form of an increase in evening body temperature in the summer and a decrease in the winter. The remaining parameters, i.e. heart rate and respiratory rate, can also unfavourably increase, mainly in the summer. Horses should have fewer problems maintaining normal physiological parameters in winter, even fewer in autumn, and the fewest in spring.


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