Do the high energy lifestyles of shorebirds result in high maximal metabolic rates? Basal and maximal metabolic rates in least and pectoral sandpipers during migration

2019 ◽  
Vol 50 (4) ◽  
Author(s):  
Nathan E. Thomas ◽  
David L. Swanson
Keyword(s):  
High Energy ◽  
Metabolic Rates

scholarly journals Reproductive energetics of adult male yellow-bellied marmots (Marmota flaviventris)

1995 ◽  
Vol 73 (10) ◽  
pp. 1791-1797 ◽  
Author(s):  
Carmen M. Salsbury ◽  
Kenneth B. Armitage
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Adult Male ◽  
Reproductive Investment ◽  
High Energy ◽  
Male Reproductive Success ◽  
Metabolic Rates ◽  
Marmota Flaviventris ◽  
Term Survival ◽  
Active Season

We examined the energy expenditure of adult male yellow-bellied marmots (Marmota flaviventris) and its relationship to various female-defense characteristics critical to male reproductive success. Resting metabolic rates of males were estimated in the laboratory via oxygen-consumption analysis, and field metabolic rates were estimated using a doubly labeled water technique. Male home-range size, number of females defended by males, dispersion of females in the habitat, and date into the active season were considered to be predictors of male energy expenditure in excess of maintenance costs (field metabolic rate minus resting metabolic rate). Energy expenditure was best explained by a defensibility index based on the number and dispersion of females defended; expenditure increased with number and dispersion of females. Energy expenditure increased with date into the active season. Environmental constraints on male activity during the mating season may have led to a shift in male reproductive investment to later in the season, when intruder pressure by conspecifics increased. No short-term survival costs were associated with high energy expenditure; males appeared to engage in reproductive behaviors congruent with their physiological capabilities.

A Comparison of the Effects of Hypothermia, Pentobarbital, and Isoflurane on Cerebral Energy Stores at the Time of Ischemic Depolarization 

1995 ◽  
Vol 82 (5) ◽  
pp. 1209-1215 ◽  
Author(s):  
Marleen Verhaegen ◽  
Paul A. Iaizzo ◽  
Michael M. Todd
Keyword(s):  
Nitrous Oxide ◽  
Large Dose ◽  
Energy Charge ◽  
Adenosine Diphosphate ◽  
High Energy ◽  
Metabolic Rates ◽  
Atp Concentration ◽  
The Moment ◽  
The Brain ◽  
Oxide Anesthesia

Background In an accompanying article, we report that hypothermia (27-28 degrees C) delayed postischemic cortical depolarization longer than did large-dose pentobarbital or isoflurane anesthesia, even though preischemic cerebral metabolic rates for glucose were similar in the three groups. To examine the mechanism that may underlie these differences, we measured the cerebral concentrations of high-energy phosphates (including adenosine triphosphate [ATP] and adenosine diphosphate) in normal conditions and at the moment of depolarization. Methods Rats were anesthetized with 0.8% halothane/50% N2O and prepared for measurement of the cortical direct-current potential by glass microelectrodes. Animals were assigned to one of four groups: (1) halothane/nitrous oxide anesthesia, pericranial temperature approximately 38 degrees C; (2) halothane/nitrous oxide, approximately 28 degrees C; (3) halothane/nitrous oxide anesthesia with pentobarbital added to achieve electroencephalographic isoelectricity, approximately 38 degrees C; or (4) 2.4% isoflurane/50% N2O anesthesia (with electroencephalographic isoelectricity), approximately 38 degrees C. The latter three groups were chosen on the basis of earlier work showing similar cerebral metabolic rates for glucose. In a subgroup of each, circulatory arrest was induced with KCl and the brain was frozen in situ (with liquid nitrogen) at the moment of cortical depolarization. In remaining animals, the brain was frozen without any ischemia. Tissue ATP, adenosine diphosphate, adenosine monophosphate, and phosphocreatine concentrations were measured by high-performance liquid chromatography. Results High-energy phosphate concentrations in nonischemic brain tissue were similar in all groups (e.g., ATP concentration 2.47-2.79 mumol/g brain). With ischemia, depolarization occurred when ATP concentrations had decreased to 13-18% of normal. There were no significant differences in the concentration of any compound or in the energy charge among the groups, even though the time until depolarization was much longer in hypothermic animals (242 s) than in animals receiving large doses of anesthesia (119 and 132 s) or in normothermic halothane/nitrous oxide animals (73 s). Conclusions The ATP/energy charge threshold for cortical depolarization was similar in all groups despite differing temperature or anesthetic conditions. Because hypothermia increased the time until depolarization, the rate of decrease in ATP concentration must have been slower in these animals than in the two groups receiving large-dose anesthetics, despite similar preischemic cerebral metabolic rates for glucose. This finding is similar to that of earlier studies and indicates that factors other than preischemic metabolic rate are responsible for controlling energy utilization after ischemia.

The constraints on cephalopods: why squid aren't fish

1986 ◽  
Vol 64 (8) ◽  
pp. 1591-1605 ◽  
Author(s):  
R. K. O'Dor ◽  
D. M. Webber
Keyword(s):  
Convergent Evolution ◽  
High Energy ◽  
Life Cycles ◽  
Metabolic Rates ◽  
Short Life ◽  
Jet Propulsion ◽  
Reproductive Patterns ◽  
Anatomical Basis ◽  
Physiology And Biochemistry ◽  
Physiological And Biochemical

The convergent evolution of cephalopods and fish has often been discussed on an anatomical basis, but recent advances in the knowledge of cephalopod life cycles, physiology, and biochemistry suggest that there are constraints on cephalopods that prevent them from competing directly with fish. These advances are reviewed against the background of detailed information on fish from the perspective that the basic inefficiency of the jet-propulsion system has required bioenergetic, physiological, and biochemical adaptations in squid which maximize their metabolic rates. Such "high-energy" adaptations are suggested to have resulted in the short life history and semelparous reproductive patterns that seem to characterize these coleoid cephalopods. Conversely, the physiology and biochemistry offish give them distinct advantages for long lives and iteroparity.

The high-energy aerial insectivore lifestyle of swallows does not produce clear thermogenic side effects

The Auk ◽  
2021 ◽  
Author(s):  
Yufeng Zhang ◽  
Kang Nian Yap ◽  
Kyle T David ◽  
David L Swanson
Keyword(s):  
Side Effects ◽  
High Energy ◽  
Foraging Strategies ◽  
Activity Levels ◽  
Metabolic Rates ◽  
Aerobic Activity ◽  
Pace Of Life ◽  
Aerial Insectivore ◽  
Aerial Insectivores ◽  
Temperate Birds

AbstractEcological traits related to pace of life, such as foraging strategies and activity levels, influence daily energy expenditure (DEE) and can affect fitness. A fast pace of life tends to be supported by high-energy aerobic activity and is positively correlated with high DEE and basal and maximal metabolic rates in some endotherms. Given that maximal capacities for exercise and thermogenesis are both functions of aerobic muscle output and are often positively correlated with each other, high-energy aerobic lifestyles might be associated with high aerobic capacities, which would be expected to produce high thermogenic capacities as a side effect. We tested whether the high-energy aerial insectivore lifestyle in swallows is correlated with elevated basal and maximal thermogenic metabolic rates. We measured basal (BMR) and summit (Msum = maximum cold-induced metabolic rate) metabolic rates in 6 species of swallows (Hirundinidae) and combined these data with literature data for additional swallows (n = 10 for BMR; n = 8 for Msum) and non-aerial insectivore birds (n = 215 for BMR; n = 64 for Msum) to address the hypothesis that swallows have higher BMR and Msum than non-aerial insectivores. BMR in swallows was significantly higher than for non-aerial insectivore birds for phylogenetically adjusted analyses after correcting for body mass and region of origin (tropical vs. temperate). In contrast, Msum did not differ significantly between swallows and non-aerial insectivores. Thermogenic scope (Msum – BMR), however, was lower in tropical non-aerial insectivore birds compared with tropical swallows and temperate birds. This suggests that the aerial insectivore lifestyle elevates maintenance costs, but maximum thermogenic capacities are not clearly upregulated, despite tropical swallows having higher thermogenic scope than tropical non-aerial insectivores. These data suggest that the high-energy aerial insectivore lifestyle does not produce strong thermogenic side effects in swallows.

High-energy turnover at low temperatures: recovery from exhaustive exercise in Antarctic and temperate eelpouts

1998 ◽  
Vol 274 (6) ◽  
pp. R1789-R1796 ◽  
Author(s):  
I. Hardewig ◽  
P. L. M. Van Dijk ◽  
H. O. Pörtner
Keyword(s):  
Low Temperatures ◽  
White Muscle ◽  
Antarctic Fish ◽  
High Energy ◽  
Aerobic Metabolism ◽  
Metabolic Rates ◽  
Energy Turnover ◽  
Muscle Lactate ◽  
Pronounced Increase ◽  
The Antarctic

Earlier work on Notothenioids led to the hypothesis that a reduced glycolytic capacity is a general adaptation to low temperatures in Antarctic fish. In our study this hypothesis was reinvestigated by comparing changes in the metabolic status of the white musculature in two related zoarcid species, the stenothermal Antarctic eelpout Pachycara brachycephalum and the eurythermal Zoarces viviparus during exercise and subsequent recovery at 0°C. In both species, strenuous exercise caused a similar increase in white muscle lactate, a drop in intracellular pH (pHi) by about 0.5 pH units, and a 90% depletion of phosphocreatine. This is the first study on Antarctic fish that shows an increase in white muscle lactate concentrations. Thus the hypothesis that a reduced importance of the glycolytic pathway is characteristic for cold-adapted polar fish cannot hold. The recovery process, especially the clearance of white muscle lactate, is significantly faster in the Antarctic than in temperate eelpout. Based on metabolite data, we calculated that during the first hour of recovery aerobic metabolism is increased 6.6-fold compared with resting rates in P. brachycephalum vs. an only 2.9-fold increase in Z. viviparus. This strong stimulation of aerobic metabolism despite low temperatures may be caused by a pronounced increase of free ADP levels, in the context of higher levels of pHi and ATP, which is observed in the Antarctic species. Although basal metabolic rates are identical in both species, the comparison of metabolic rates during situations of high-energy turnover reveals that the stenothermal P. brachycephalum shows a higher degree of metabolic cold compensation than the eurythermal Z. viviparus. Muscular fatigue after escape swimming may be caused by a drop of the free energy change of ATP hydrolysis, which is shown to fall below critical levels for cellular ATPases in exhausted animals of both species.

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

Observation of Superlattice Dislocations on Cube Planes in Ni3Al

1973 ◽  
Vol 31 ◽  
pp. 174-175 ◽  
Author(s):  
J. M. Oblak ◽  
W. H. Rand
Keyword(s):  
Nearest Neighbor ◽  
Antiphase Boundary ◽  
Nearest Neighbors ◽  
High Energy ◽  
Cross Slip ◽  
Octahedral Plane ◽  
Trapping Mechanism ◽  
Slip Traces

The energy of an a/2 <110> shear antiphase. boundary in the Ll2 expected to be at a minimum on {100} cube planes because here strue ture is there is no violation of nearest-neighbor order. The latter however does involve the disruption of second nearest neighbors. It has been suggested that cross slip of paired a/2 <110> dislocations from octahedral onto cube planes is an important dislocation trapping mechanism in Ni3Al; furthermore, slip traces consistent with cube slip are observed above 920°K.Due to the high energy of the {111} antiphase boundary (> 200 mJ/m2), paired a/2 <110> dislocations are tightly constricted on the octahedral plane and cannot be individually resolved.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Void-Lattice Formation in Natural Fluorite by Electron Irradiation

1976 ◽  
Vol 34 ◽  
pp. 614-615 ◽  
Author(s):  
L.E. Murr
Keyword(s):  
Electron Microscope ◽  
Electron Irradiation ◽  
Heavy Ion ◽  
High Energy ◽  
Stoichiometric Ratio ◽  
Direct Observations ◽  
Transmission Electron ◽  
Anion Vacancies ◽  
Cation And Anion Vacancies ◽  
Lattice Formation

The production of void lattices in metals as a result of displacement damage associated with high energy and heavy ion bombardment is now well documented. More recently, Murr has shown that a void lattice can be developed in natural (colored) fluorites observed in the transmission electron microscope. These were the first observations of a void lattice in an irradiated nonmetal, and the first, direct observations of color-center aggregates. Clinard, et al. have also recently observed a void lattice (described as a high density of aligned "pores") in neutron irradiated Al2O3 and Y2O3. In this latter work, itwas pointed out that in order that a cavity be formed,a near-stoichiometric ratio of cation and anion vacancies must aggregate. It was reasoned that two other alternatives to explain the pores were cation metal colloids and highpressure anion gas bubbles.Evans has proposed that void lattices result from the presence of a pre-existing impurity lattice, and predicted that the formation of a void lattice should restrict swelling in irradiated materials because it represents a state of saturation.

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