scholarly journals Consumer trait responses track change in resource supply along replicated thermal gradients

2021 ◽  
Vol 288 (1964) ◽  
Author(s):  
E. R. Moffett ◽  
D. C. Fryxell ◽  
F. Lee ◽  
E. P. Palkovacs ◽  
K. S. Simon

Rising temperatures may alter consumer diets through increased metabolic demand and altered resource availability. However, current theories assessing dietary shifts with warming do not account for a change in resource availability. It is unknown whether consumers will increase consumption rates or consume different resources to meet increased energy requirements and whether the dietary change will lead to associated variation in morphology and nutrient utilization. Here, we used populations of Gambusia affinis across parallel thermal gradients in New Zealand (NZ) and California (CA) to understand the influence of temperature on diets, morphology and stoichiometric phenotypes. Our results show that with increasing temperature in NZ, mosquitofish consumed more plant material, whereas in CA mosquitofish shifted towards increased consumption of invertebrate prey. In both regions, populations with plant-based diets had fuller guts, longer relative gut lengths, better-orientated mouths and reduced body elemental %C and N/P. Together, our results show multiple pathways by which consumers may alter their feeding patterns with rising temperatures, and they suggest that warming-induced changes to resource availability may be the principal determinant of which pathway is taken.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Benjamin A. H. Jensen ◽  
Jacob B. Holm ◽  
Ida S. Larsen ◽  
Nicole von Burg ◽  
Stefanie Derer ◽  
...  

AbstractInteractions between host and gut microbial communities are modulated by diets and play pivotal roles in immunological homeostasis and health. We show that exchanging the protein source in a high fat, high sugar, westernized diet from casein to whole-cell lysates of the non-commensal bacterium Methylococcus capsulatus Bath is sufficient to reverse western diet-induced changes in the gut microbiota to a state resembling that of lean, low fat diet-fed mice, both under mild thermal stress (T22 °C) and at thermoneutrality (T30 °C). Concomitant with microbiota changes, mice fed the Methylococcus-based western diet exhibit improved glucose regulation, reduced body and liver fat, and diminished hepatic immune infiltration. Intake of the Methylococcu-based diet markedly boosts Parabacteroides abundances in a manner depending on adaptive immunity, and upregulates triple positive (Foxp3+RORγt+IL-17+) regulatory T cells in the small and large intestine. Collectively, these data point to the potential for leveraging the use of McB lysates to improve immunometabolic homeostasis.


1985 ◽  
Vol 248 (5) ◽  
pp. R595-R600 ◽  
Author(s):  
J. W. Hicks ◽  
S. C. Wood

Temperature regulation during external (lowered lung PO2) and internal hypoxia (anemia) was examined in four species of lizards. Exposure to a hypoxic gas mixture in a thermogradient resulted in the animals lowering their selected (preferred) body temperature. A 50% reduction in the O2 carrying capacity of the blood also reduced the selected body temperature. Lizards "shuttle" when forced to select a temperature either above or below their normal selected temperature. Exposure to hypoxia decreases the upper and lower exit temperatures during shuttling. Furthermore, a decrease in the inspired O2 causes the rate of heating to no longer exceed the rate of cooling as is normal. The behavioral reduction of body temperature and the altered neural and physiological aspects of temperature regulation appear to be generalized responses to impaired O2 transport and not PO2 per se. The reduced body temperature, by lowering metabolic demand, provides an effective, even life-saving, adaptation to hypoxia.


1997 ◽  
Vol 506 ◽  
Author(s):  
W. J. Cho ◽  
J. O. Lee ◽  
K. S. Chun

ABSTRACTThe hydraulic conductivities in water saturated bentonites at different densities were measured within temperature range of 20 to 80 °C. The results show that the hydraulic conductivities increase with increasing temperature. The hydraulic conductivities of bentonites at the temperature of 80 °C increase up to about 3 times as high as those at 20 °C. The measured values are in good agreement with those predicted. The change in viscosity of water with temperature contributes greatly to increase of hydraulic conductivity.


1995 ◽  
Vol 50 (9) ◽  
pp. 864-870 ◽  
Author(s):  
P. Krajnik ◽  
R. M. Quint ◽  
S. Solar ◽  
N. Getoff ◽  
G. Sontag

AbstractThe formation of tyrosine isomers by γ-radiolysis of neutral aqueous phenylalanine solutions was found to be strongly dependent on oxygen concentration and temperature. Changing the dose rate did not influence the degradation process. In the presence of 0.25 x 10-3 mol dm-3 oxygen at room temperature the yields of o-tyrosine as well as of m- and p-tyrosine drop from G(o-Tyr) = 0.5 and G(m-Tyr) = G(p-Tyr) = 0.4 at a dose of 0.3 kGy to 0.18 and 0.16 at 2.5 kGy, respectively. In solutions containing 1.25 x 10-3 mol dm-3 oxygen the initial yields remain unchanged but decrease at 2.5 kGy only to G(o-Tyr) = 0.3 and G(m-Tyr) = G(p-Tyr) = 0.20. Under the latter reaction conditions also 3,4-dihydroxyphenylalanine was found.Samples irradiated in frozen state did not show remarkable radiolysis of phenylalanine and tyrosine formation. In the range between 5 and 20°C no essential influence of temperature on the phenylalanine radiolysis and tyrosine yields was observable. The obtained results are important for methods using the tyrosine yields as markers for the detection of irradiated food. Storage conditions and irradiation temperature play an essential role on radiation induced changes of food.


2019 ◽  
Vol 37 (9-10) ◽  
pp. 745-763 ◽  
Author(s):  
Zhijun Wang ◽  
Xiaojuan Wang ◽  
Weiqin Zuo ◽  
Xiaotong Ma ◽  
Ning Li

The capacity of coal to adsorb methane is greatly affected by temperature and, in recent years, temperature-dependent adsorption has been studied by many researchers. Even so, comprehensive conclusions have not been reached and conflicting experimental results are common. This paper reviews the current state of research regarding the temperature-dependent adsorption of methane in coal and catalogs the conclusions from experiments conducted on that subject by 28 researchers, as published between 1995 and 2017. Probability theory and statistics are used to show that the conclusion generally accepted by most researchers is that the amount of methane adsorbed by coal decreases with increasing temperature. It is highly likely that the Langmuir volume decreases as the temperature rises, and it is also probable that the Langmuir pressure increases at higher temperatures. Equations are presented that express the relationships between methane adsorption, Langmuir volume, Langmuir pressure, and temperature. Future research should be directed toward determining the relationship between Langmuir pressure and temperature. The results of the study presented herein provide a theoretical basis for predicting the gas content in coal seams and improving the efficiency of coalbed methane development.


1988 ◽  
Vol 254 (4) ◽  
pp. R611-R615 ◽  
Author(s):  
C. D. Moyes ◽  
L. T. Buck ◽  
P. W. Hochachka

Mitochondria isolated from red muscle of carp (Cyprinus carpio) were used to investigate the effects of temperature and extramitochondrial pH (pHe) on the mitochondrial pH gradient and respiratory properties. Mitochondria from animals acclimated to 10 degrees C were isolated and incubated in KCl-based media with 0.2 mM lauroylcarnitine (C-12) as substrate. Maximal respiratory control ratios (RCR = state 3/state 4) were 16-18 between pH 6.7 and 7.4 at 10 degrees C; RCR values were 9-12 between pH 6.5 and 7.1 at 30 degrees C. Changes in RCR values were due primarily to changes in the state 3 rate (in the presence of ADP). Mitochondrial pH was determined by measuring 5,5-[2-14C]dimethyloxazolidine-2,4-dione distribution, using [14C]sucrose as an extramatrical marker. The pH gradient was inversely related to pHe. At any particular pHe, the mitochondrial pH gradient decreased with increasing temperature. However, if pHe was varied in the same manner that intracellular pH changes with temperature in vivo, the pH gradient was maintained constant at approximately 0.4 U at 10, 20, and 30 degrees C. These data suggest that carp red muscle mitochondria defend an appropriate mitochondrial pH gradient with temperature-induced changes in intracellular pH.


2020 ◽  
Vol 9 (7) ◽  
pp. 2108
Author(s):  
Paulo Ávila-Gómez ◽  
Pablo Hervella ◽  
Andrés Da Silva-Candal ◽  
María Pérez-Mato ◽  
Manuel Rodríguez-Yáñez ◽  
...  

Although hyperthermia is associated with poor outcomes in ischaemic stroke (IS), some studies indicate that high body temperature may benefit reperfusion therapies. We assessed the association of temperature with effective reperfusion (defined as a reduction of ≥8 points in the National Institute of Health Stroke Scale (NIHSS) within the first 24 h) and poor outcome (modified Rankin Scale (mRS) > 2) in 875 retrospectively-included IS patients. We also studied the influence of temperature on thrombolytic (cellular fibronectin (cFn); matrix metalloproteinase 9 (MMP-9)) and inflammatory biomarkers (tumour necrosis factor-alpha (TNF-α), interleukin 6 (IL-6)) and their relationship with effective reperfusion. Our results showed that a higher temperature at 24 but not 6 h after stroke was associated with failed reperfusion (OR: 0.373, p = 0.001), poor outcome (OR: 2.190, p = 0.005) and higher IL-6 levels (OR: 0.958, p < 0.0001). Temperature at 6 h was associated with higher MMP-9 levels (R = 0.697; p < 0.0001) and effective reperfusion, although this last association disappeared after adjusting for confounding factors (OR: 1.178, p = 0.166). Our results suggest that body temperature > 37.5 °C at 24 h, but not at 6 h after stroke, is correlated with reperfusion failure, poor clinical outcome, and infarct size. Mild hyperthermia (36.5–37.5 °C) in the first 6 h window might benefit drug reperfusion therapies by promoting clot lysis.


2012 ◽  
Vol 706-709 ◽  
pp. 768-773
Author(s):  
Masahiro Nishida ◽  
Koichi Hayashi ◽  
Junichi Nakagawa ◽  
Yoshitaka Ito

The influence of temperature on crater formation and ejecta composition in thick aluminum alloy targets were investigated for impact velocities ranging from approximately 1.5 to 3.5 km/s using a two-stage light-gas gun. The diameter and depth of the crater increased with increasing temperature. The ejecta size at low temperature was slightly smaller than that at high temperature and room temperature. Temperature did not affect the size ratio of ejecta. The scatter diameter of the ejecta at high temperature was slightly smaller than those at low and room temperatures.


2014 ◽  
Vol 1052 ◽  
pp. 137-142
Author(s):  
Jun Jie Sheng ◽  
Yu Qing Zhang ◽  
Shu Yong Li ◽  
Hua Ling Chen

Temperature can significantly affect the performance of a viscoelastic dielectric elastomer (DE). In the current study, we use a thermodynamic model to characterize the influence of temperature on the viscoelastic electromechanical response undergoing a constant electric load by taking into account the temperature dependent elastic modus and dielectric constant. Due to the significant viscoelasticity in the dielectric elastomer, DE membrane creeps in time and the inelastic stretch of DE is smaller than that of the total stretch. The results show that the total stretch of the viscoelastic electromechanical deformation increases with the increasing temperature until suffering electromechanical instability at a high temperature; the actuation performance is dominated by the moduli of the elastomer. This may be used to guide the design of dielectric elastomer actuators undergoing temperature variation.


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