Transiting to depth disrupts overall dynamic body acceleration and oxygen consumption rate in freely diving Steller sea lions

2016 ◽  
Vol 562 ◽  
pp. 221-236 ◽  
Author(s):  
BL Volpov ◽  
ET Goundie ◽  
DAS Rosen ◽  
JPY Arnould ◽  
AW Trites
2015 ◽  
Vol 185 (6) ◽  
pp. 695-708 ◽  
Author(s):  
Beth L. Volpov ◽  
David A. S. Rosen ◽  
Andrew W. Trites ◽  
John P. Y. Arnould

2020 ◽  
Author(s):  
Evan E. Byrnes ◽  
Karissa O. Lear ◽  
Lauran R. Brewster ◽  
Nicholas M. Whitney ◽  
Matthew J. Smukall ◽  
...  

ABSTRACTLife history, reproduction, and survival are fundamentally linked to energy expenditure and acquisition. Dynamic Body Acceleration (DBA), measured through animal-attached data-loggers or transmitters, has emerged as a powerful method for estimating field metabolic rates of free-ranging individuals. After using respirometry to calibrate oxygen consumption rate with DBA in captive settings, predictive models can be applied to DBA data collected from free-ranging individuals. However, laboratory calibrations are generally performed on a narrow size range of animals, which may introduce biases when predictive models are applied to differently sized individuals in the field. Here, we tested the influence of scale effects on the ability of a single predictive model to predict over a range of body sizes. We performed respirometry experiments with individuals spanning one order of magnitude in body mass (1.74–17.15 kg) and used a two-step modelling process to assess the intra-specific scale dependence of the -DBA relationship and incorporate such dependencies into the covariates of predictive models. The final predictive model showed scale dependence; the slope of the -DBA relationship was strongly allometric (M1.55), whereas the intercept term scaled closer to isometry (M1.08). Using bootstrapping and simulations, we tested the performance of this covariate-corrected model against commonly used methods of accounting for mass effects on the -DBA relationship and found lowest error and bias in the covariate-corrected approach. The strong scale dependence of the -DBA relationship indicates that caution must be exercised when models developed using one size class are applied to individuals of different sizes.Summary statementThe relationship between oxygen consumption rate and dynamic body acceleration is allometrically dependent, and models incorporate different slope and intercept scaling rates estimate metabolic rates more accurately than mass-specific approaches.


Author(s):  
Grażyna Mazurkiewicz-Boroń ◽  
Teresa Bednarz ◽  
Elżbieta Wilk-Woźniak

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.


2021 ◽  
Vol 22 (9) ◽  
pp. 4366
Author(s):  
Rebecca L. Paszkiewicz ◽  
Richard N. Bergman ◽  
Roberta S. Santos ◽  
Aaron P. Frank ◽  
Orison O. Woolcott ◽  
...  

The authors wish to make the following corrections to this paper [...]


2021 ◽  
Vol 22 (16) ◽  
pp. 8367
Author(s):  
Hien Lau ◽  
Shiri Li ◽  
Nicole Corrales ◽  
Samuel Rodriguez ◽  
Mohammadreza Mohammadi ◽  
...  

Pre-weaned porcine islets (PPIs) represent an unlimited source for islet transplantation but are functionally immature. We previously showed that necrostatin-1 (Nec-1) immediately after islet isolation enhanced the in vitro development of PPIs. Here, we examined the impact of Nec-1 on the in vivo function of PPIs after transplantation in diabetic mice. PPIs were isolated from pancreata of 8–15-day-old, pre-weaned pigs and cultured in media alone, or supplemented with Nec-1 (100 µM) on day 0 or on day 3 of culture (n = 5 for each group). On day 7, islet recovery, viability, oxygen consumption rate, insulin content, cellular composition, insulin secretion capacity, and transplant outcomes were evaluated. While islet viability and oxygen consumption rate remained high throughout 7-day tissue culture, Nec-1 supplementation on day 3 significantly improved islet recovery, insulin content, endocrine composition, GLUT2 expression, differentiation potential, proliferation capacity of endocrine cells, and insulin secretion. Adding Nec-1 on day 3 of tissue culture enhanced the islet recovery, proportion of delta cells, beta-cell differentiation and proliferation, and stimulation index. In vivo, this leads to shorter times to normoglycemia, better glycemic control, and higher circulating insulin. Our findings identify the novel time-dependent effects of Nec-1 supplementation on porcine islet quantity and quality prior to transplantation.


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