scholarly journals Thyroid-Mediated Metabolic Differences Underlie Ecological Specialization of Extremophile Salmonids in the Arctic Lake El’gygytgyn

2021 ◽  
Vol 9 ◽  
Author(s):  
Evgeny V. Esin ◽  
Grigorii N. Markevich ◽  
Dmitriy V. Zlenko ◽  
Fedor N. Shkil
Keyword(s):  
Metabolic Rate ◽  
Wide Spectrum ◽  
Physiological Adaptation ◽  
The Arctic ◽  
Cellular Respiration ◽  
Third Wave ◽  
Ecological Specialization ◽  
Thyroid Status ◽  
Metabolic Characteristics ◽  
Quaternary Climate

El’gygytgyn, the only “ancient lake” in the Arctic (3.6 MY), is a deep (176 m) and extremely cold (always ≤ 4°C) waterbody inhabited by unique salmonids, which colonized the ecosystem stepwise during the global fluctuations of the Quaternary climate. The descendant of the first-wave-invaders (long-finned charr) dwells in the deep waters and feeds on amphipods. The second-wave-invaders (smallmouth charr) consume copepods in the mid-waters. Recent third-wave-invaders (Boganida charr) are spread throughout the ecosystem and feed on insects when they are young shifting to piscivory at an older age. Here, we present the data on the charrs’ thyroid status and metabolic characteristics, confirming their ecological specialization. The long-finned charr exhibits an extremely low thyroid content, the substitution of carbohydrates for lipids in the cellular respiration, an increased hemoglobin level and a high antioxidant blood capacity. These traits are likely to be the legacy of anaerobic survival under perennial ice cover during several Quaternary glaciations. Moderate thyroid status and reduced metabolic rate of the smallmouth charr, along with an inactive lifestyle, could be regarded as a specialization to saving energy under the low food supply in the water column. The piscivorous Boganida charr could be sub-divided into shallow-water and deep-water groups. The former demonstrates a significantly elevated thyroid status and increased metabolism. The latter is characterized by a reduced thyroid level, metabolic rate, and lipid accumulation. Thus, the endemic El’gygytgyn charrs represent a wide spectrum of contrast physiological adaptation patterns essential to survive in sympatry under extremely cold conditions.

scholarly journals Temperature and Relative Humidity Profile Retrieval from Fengyun-3D/HIRAS in the Arctic Region

2021 ◽  
Vol 13 (10) ◽  
pp. 1884
Author(s):  
Jingjing Hu ◽  
Yansong Bao ◽  
Jian Liu ◽  
Hui Liu ◽  
George P. Petropoulos ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Real Time ◽  
Wide Spectrum ◽  
Warm Season ◽  
Arctic Region ◽  
Cold Season ◽  
The Arctic ◽  
Practical Applications ◽  
A New Technique ◽  
The Arctic Region

The acquisition of real-time temperature and relative humidity (RH) profiles in the Arctic is of great significance for the study of the Arctic’s climate and Arctic scientific research. However, the operational algorithm of Fengyun-3D only takes into account areas within 60°N, the innovation of this work is that a new technique based on Neural Network (NN) algorithm was proposed, which can retrieve these parameters in real time from the Fengyun-3D Hyperspectral Infrared Radiation Atmospheric Sounding (HIRAS) observations in the Arctic region. Considering the difficulty of obtaining a large amount of actual observation (such as radiosonde) in the Arctic region, collocated ERA5 data from European Centre for Medium-Range Weather Forecasts (ECMWF) and HIRAS observations were used to train the neural networks (NNs). Brightness temperature and training targets were classified using two variables: season (warm season and cold season) and surface type (ocean and land). NNs-based retrievals were compared with ERA5 data and radiosonde observations (RAOBs) independent of the NN training sets. Results showed that (1) the NNs retrievals accuracy is generally higher on warm season and ocean; (2) the root-mean-square error (RMSE) of retrieved profiles is generally slightly higher in the RAOB comparisons than in the ERA5 comparisons, but the variation trend of errors with height is consistent; (3) the retrieved profiles by the NN method are closer to ERA5, comparing with the AIRS products. All the results demonstrated the potential value in time and space of NN algorithm in retrieving temperature and relative humidity profiles of the Arctic region from HIRAS observations under clear-sky conditions. As such, the proposed NN algorithm provides a valuable pathway for retrieving reliably temperature and RH profiles from HIRAS observations in the Arctic region, providing information of practical value in a wide spectrum of practical applications and research investigations alike.All in all, our work has important implications in broadening Fengyun-3D’s operational implementation range from within 60°N to the Arctic region.

Stability of basal metabolic rate on a polar expedition

1961 ◽  
Vol 16 (3) ◽  
pp. 397-400 ◽  
Author(s):  
H. E. Lewis ◽  
J. P. Masterton ◽  
S. Rosenbaum
Keyword(s):  
Young Adults ◽  
Metabolic Rate ◽  
Basal Metabolic Rate ◽  
Field Work ◽  
Basal Metabolism ◽  
The Arctic ◽  
Polar Regions ◽  
Exposure To Cold ◽  
Efficient Protection ◽  
At Home

The basal metabolism studied in 29 young adults on 349 occasions over 2 years in the Arctic was 37.4 (sd α 3.7) kcal/m-2/hr-1, and well within the normal British standards. The variability showed no relationship to season. On polar expeditions, men's physiologically significant exposure to cold is small because of efficient protection by clothing and shelter. Information is needed about precise differences of microclimate in the polar regions and at home. Field work could more profitably be directed to the cognate problem of costs of various activities in the cold rather than basal metabolic rate. Submitted on April 25, 1960

Beyond BMI: Personality Traits’ Associations With Adiposity and Metabolic Rate

2021 ◽  
Author(s):  
Kadri Arumäe ◽  
René Mõttus ◽  
Uku Vainik
Keyword(s):  
Metabolic Rate ◽  
Personality Traits ◽  
Personality Trait ◽  
Genetic Associations ◽  
Psychological Traits ◽  
Neo Personality Inventory ◽  
Metabolic Characteristics ◽  
Metabolic Marker ◽  
Polygenic Scores ◽  
Metabolic Variables

Various personality traits are known to correlate with body mass index (BMI). However, rarely have studies looked beyond BMI to understand how adiposity and other metabolic characteristics relate to psychological traits. We explored personality traits’ phenotypic and genetic associations with basal metabolic rate (BMR) and an improved index of adiposity—relative fat mass (RFM)—and assessed how personality traits’ associations with RFM differ from their associations with BMI. In a subsample of the Estonian Biobank (N = 3,535), we correlated RFM, BMI, and BMR, as well as their polygenic scores, with the five domains and 30 facets of NEO Personality Inventory-3. Various traits, notably Openness and its facets, associated with RFM above and beyond BMI. Assertiveness consistently correlated with BMR, mirroring associations with conceptually similar traits in non-human animals, but not with RFM as may have been expected based on previous studies. Genetic analyses suggested that some personality trait–metabolic marker associations have genetic bases while others may be environmental in origin. The use of BMI can lead to both attenuated and inflated estimates of personality trait–adiposity associations. Personality traits may be involved in the development of overweight, but metabolic variables may additionally contribute to differences in personality traits.

scholarly journals Energy Cost of Running in an Arctic Fox, Alopex lagopus

2003 ◽  
Vol 117 (3) ◽  
pp. 430 ◽  
Author(s):  
Eva Fuglei ◽  
Nils A. Øritsland
Keyword(s):  
Heart Rate ◽  
Metabolic Rate ◽  
Energy Cost ◽  
The Arctic ◽  
Arctic Fox ◽  
Alopex Lagopus ◽  
Energy Cost Of Running ◽  
Radio Transmitters ◽  
The Relationship ◽  
Determine Effect

This work was conducted to determine effect of season and starvation on metabolic rate during running in the Arctic Fox (Alopex lagopus) on Svalbard (78°55’N, 11°56’E), Norway. Indirect calorimetry was used to measure metabolic rate of foxes running on a treadmill and heart rate was monitored using implanted radio transmitters. The relationship between heart rate and metabolic rate was also examined. Metabolic rate increased with running speed. In July the metabolic rate during running almost fitted general equations predicted for mammals, while it was up to 20% lower in January, indicating seasonal variation in metabolic rate. There was a significant positive linear relationship between heart rate and weight specific metabolic rate, suggesting that heart rate can be used as an indicator of metabolic rate. Starvation for 11 days decreased the net cost of running by 13% in January and 17% in July, suggesting that a starved fox runs more energetically efficient than when fed. Heart rate measured in July decreased by 27% during starvation. Re-feeding reversed the starvation-induced reduction in metabolic rate and heart rate during running almost up to post-absorptive levels. The present results are from one fox, and must be considered as preliminary data until further studies are conducted.

scholarly journals Laboratory Metabolism of Incubating Semipalmated Plovers

The Condor ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 966-970
Author(s):  
Mark Williamson ◽  
Joseph B. Williams ◽  
Erica Nol
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Breeding Season ◽  
Basal Metabolic Rate ◽  
Low Temperatures ◽  
Thermal Conductance ◽  
Basal Metabolism ◽  
The Arctic ◽  
Lower Critical Temperature ◽  
Metabolic Data

Abstract Abstract The Semipalmated Plover (Charadriussemipalmatus), anarctic-nesting migratory shorebird, regularlyencounters low temperatures during the breedingseason. We measured the basal metabolism of adultsduring incubation at Churchill, Manitoba, Canada todetermine basal metabolic rate (BMR),lower critical temperature(Tlc), total evaporative waterloss (TEWL), and dry thermal conductance(Cm). BMR and Tlcwere 47.4 kJ day−1and 23.3°C, respectively, TEWL was2.5 mL H2O−d,and Cm was1.13 mW g−1 °C−1.Measured BMR and Tlc were consistentwith high values found for other shorebird speciesbreeding in the Arctic, while Cm was18% higher than predicted from allometricequations. These metabolic data suggest thatSemipalmated Plovers are adapted to balance therequirements of incubation against energetic andthermoregulatory demands in the Arctic, especiallyin harsh early breeding season conditions.

Regulation of metabolic rate in Svalbard and Norwegian reindeer

1984 ◽  
Vol 247 (5) ◽  
pp. R837-R841 ◽  
Author(s):  
K. J. Nilssen ◽  
J. A. Sundsfjord ◽  
A. S. Blix
Keyword(s):  
Body Weight ◽  
Critical Temperature ◽  
Food Intake ◽  
Metabolic Rate ◽  
Seasonal Changes ◽  
Serum Levels ◽  
Physiological Adaptation ◽  
Conservation Of Energy ◽  
Winter Food ◽  
Lower Critical Temperature

Food intake, body weight, serum levels of triiodothyronine (T3) and free thyroxine (FT4), and metabolic rate were measured at intervals in Svalbard (SR) and Norwegian (NR) reindeer. From summer to winter food intake decreased 57 (SR) and 55% (NR), while body weight decreased 8.6 (SR) and 3.8% (NR). In SR T3 and FT4 changed seasonally, whereas this was only evident for T3 in NR. Resting (standing) metabolic rate (RMR) in winter was 1.55 (SR) and 2.05 W X kg-1 (NR), lower critical temperature (TLC) being -50 (SR) and -30 degrees C (NR). RMR in summer was 2.15 (SR) and 2.95 W X kg-1 (NR), TLC being -15 (SR) and 0 degrees C (NR). Seasonal changes in T3 and FT4 did not coincide with changes in food intake or RMR in either SR or NR. RMR did, however, correlate with food intake. This indicates that seasonal changes in RMR are due to the thermic effects of feeding and represent no physiological adaptation aimed at conservation of energy during winter.

Interaction Between Thyroxine and Dibenzyline on Metabolic Rate

1957 ◽  
Vol 191 (3) ◽  
pp. 573-576 ◽  
Author(s):  
Neena B. Schwartz ◽  
Gerald E. Hammond ◽  
Gerald A. Gronert
Keyword(s):  
Oxygen Consumption ◽  
Synergistic Effect ◽  
Metabolic Rate ◽  
Pressor Effect ◽  
Metabolic Rates ◽  
Thyroid Status ◽  
Experimental Animals ◽  
Rate Of Oxygen Consumption

Doses of Dibenzyline adequate to block the pressor effect of epinephrine were administered to rats with various degrees of chronic hypo- or hyperthyroidism. Rate of oxygen consumption was measured under barbiturate anesthesia. Dibenzyline decreased or did not change hypothyroid metabolic rates, but increased metabolic rates in hyperthyroid rats. The data indicated that Dibenzyline exerts a synergistic effect with thyroxine on metabolism resembling the previously reported synergism between thyroxine and epinephrine. Apparently discrepant findings presented in the literature regarding the interaction of thyroxine and Dibenzyline probably result from differences in the thyroid status of the experimental animals.

Metabolic rate does not scale with body mass in cultured mammalian cells

2007 ◽  
Vol 292 (6) ◽  
pp. R2115-R2121 ◽  
Author(s):  
Melanie F. Brown ◽  
Tyson P. Gratton ◽  
Jeffrey. A. Stuart
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Oxygen Delivery ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Mammalian Species ◽  
Cellular Respiration ◽  
Metabolic Rates ◽  
Respiration Rates ◽  
Species Specific

The allometric scaling of metabolic rate with organism body mass can be partially accounted for by differences in cellular metabolic rates. For example, hepatocytes isolated from horses consume almost 10-fold less oxygen per unit time as mouse hepatocytes [Porter and Brand, Am J Physiol Regul Integr Comp Physiol 269: R226–R228, 1995]. This could reflect a genetically programmed, species-specific, intrinsic metabolic rate set point, or simply the adaptation of individual cells to their particular in situ environment (i.e., within the organism). We studied cultured cell lines derived from 10 mammalian species with donor body masses ranging from 5 to 600,000 g to determine whether cells propagated in an identical environment (media) exhibited metabolic rate scaling. Neither metabolic rate nor the maximal activities of key enzymes of oxidative or anaerobic metabolism scaled significantly with donor body mass in cultured cells, indicating the absence of intrinsic, species-specific, cellular metabolic rate set points. Furthermore, we suggest that changes in the metabolic rates of isolated cells probably occur within 24 h and involve a reduction of cellular metabolism toward values observed in lower metabolic rate organisms. The rate of oxygen delivery has been proposed to limit cellular metabolic rates in larger organisms. To examine the effect of oxygen on steady-state cellular respiration rates, we grew cells under a variety of physiologically relevant oxygen regimens. Long-term exposure to higher medium oxygen levels increased respiration rates of all cells, consistent with the hypothesis that higher rates of oxygen delivery in smaller mammals might increase cellular metabolic rates.

scholarly journals Circum-Antarctic coastal environmental shifts during the Late Quaternary reflected by emerged marine deposits

1998 ◽  
Vol 10 (3) ◽  
pp. 345-362 ◽  
Author(s):  
Paul A. Berkman ◽  
John T. Andrews ◽  
Svante Björck ◽  
Eric A. Colhoun ◽  
Steven D. Emslie ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Late Quaternary ◽  
Marine Species ◽  
Coastal Areas ◽  
The Arctic ◽  
Marine Habitat ◽  
Marine Deposits ◽  
Quaternary Climate ◽  
Antarctic Marine ◽  
The Antarctic

This review assesses the circumpolar occurrence of emerged marine macrofossils and sediments from Antarctic coastal areas in relation to Late Quaternary climate changes. Radiocarbon ages of the macrofossils, which are interpreted in view of the complexities of the Antarctic marine radiocarbon reservoir and resolution of this dating technique, show a bimodal distribution. The data indicate that marine species inhabited coastal environments from at least 35 000 to 20 000 yr BP, during Marine Isotope Stage 3 when extensive iceberg calving created a ‘meltwater lid’ over the Southern Ocean. The general absence of these marine species from 20 000 to 8500 yr BP coincides with the subsequent advance of the Antarctic ice sheets during the Last Glacial Maximum. Synchronous re-appearance of the Antarctic marine fossils in emerged beaches around the continent, all of which have Holocene marine-limit elevations an order of magnitude lower than those in the Arctic, reflect minimal isostatic rebound as relative sea-level rise decelerated. Antarctic coastal marine habitat changes around the continent also coincided with increasing sea-ice extent and outlet glacial advances during the mid-Holocene. In view of the diverse environmental changes that occurred around the Earth during this period, it is suggested that Antarctic coastal areas were responding to a mid-Holocene climatic shift associated with the hydrological cycle. This synthesis of Late Quaternary emerged marine deposits demonstrates the application of evaluating circum-Antarctic phenomena from the glacial-terrestrial-marine transition zone.

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