Measurements of Growth and Consumption of Sauger (Stizostedion canadense): Implication for Fish Energetics Studies

1982 ◽  
Vol 39 (10) ◽  
pp. 1396-1403 ◽  
Author(s):  
Joseph W. Minton ◽  
Richard B. McLean
Keyword(s):  
Energy Equation ◽  
Specific Dynamic Action ◽  
Metabolic Efficiency ◽  
High Food ◽  
Age Classes ◽  
Energetic Costs ◽  
Stizostedion Canadense ◽  
Energy Stores ◽  
Fish Energetics ◽  
Body Energy

The energy budget of sauger (Stizostedion canadense), in Watts Bar Reservoir, Tennessee, was studied over a 17-mo period. Field determinations of consumption and laboratory determinations of metabolism were incorporated into the balanced energy equation of Winberg to predict growth in energy value of sauger in age-classes I+ and II+. The equation included energetic costs of specific dynamic action and the metabolic efficiency penalty of metabolizing body energy stores. Observed and predicted growth during the warm months, March through October, agreed within 2.5–9.6% for the I+ and II+ age-classes, respectively. Observed and predicted growth over the winter for the only age-class modeled, the I+, did not agree. High food consumption during winter did not result in the amount of growth expected, suggesting that the physiological assumptions of the balanced energy equation are invalid for describing the winter energetics of sauger. We emphasize the potential error in inferring consumption from growth and metabolism.Key words: sauger, Stizostedion, bioenergetics, feeding, growth, modeling

scholarly journals Influence of a nonforage diet on plasma leptin in dairy goats throughout lactation

2002 ◽  
Vol 2002 ◽  
pp. 97-97
Author(s):  
F. Rosi ◽  
L. Rapetti
Keyword(s):  
Energy Homeostasis ◽  
Peptide Hormone ◽  
Dairy Goats ◽  
Lactating Goats ◽  
Energy Stores ◽  
The Status ◽  
Plasma Leptin ◽  
Body Energy ◽  
The Brain ◽  
By Products

Leptin is a 16kDa peptide hormone mainly secreted by fat cells to regulate of food intake and energy homeostasis, and to signal the status of body energy stores to the brain (Houseknecht et al., 1998). In ruminant, reducing feedstuffs particle size increases DM intake, particularly if feedstuffs quality is poor, due to a shorter retention time of the particles in the rumen. By-products are included in the ration to supply energy and protein, but they have often a high content of fibre. The by-product fibre has different properties than forage NDF, being characterised by particles of small dimensions and a high density. The aim of this study was to compare the plasma level of leptin in lactating goats fed a traditional silage-based diet or a totally free forage diet, throughout lactation and during the pre and post-feeding state.

Interactions between insulin and glucocorticoids in the maintenance of genetic obesity

1992 ◽  
Vol 263 (3) ◽  
pp. E550-E555
Author(s):  
P. U. Dubuc
Keyword(s):  
Body Fat ◽  
Type I Diabetes ◽  
Combined Treatment ◽  
Somatic Growth ◽  
Percent Body Fat ◽  
Immunoreactive Insulin ◽  
Type I ◽  
Obese Mice ◽  
Energy Stores ◽  
Body Energy

Glucoregulation and body composition were examined in 3-mo-old C57BL/6 ob/ob mice 6 wk after streptozotocin (STZ) or STZ plus adrenalectomy. STZ depressed somatic growth in ob/ob mice but did not cause hyperglycemia until immunoreactive insulin (IRI) was 40% (100 microU/ml) that of intact ob/ob mice. When IRI approached that of lean mice (40 microU/ml), ob/ob mice displayed severe hyperglycemia (800+ mg/dl) and other sequelae of type I diabetes but still maintained the same 50% body fat as untreated obese mice. In contrast, STZ diabetes in lean mice caused disproportionate reductions in body fat. Adrenalectomy before STZ led to the same insulinopenia, depressed growth, and hyperglycemia as STZ alone, but, after combined treatment, percent body fat declined in proportion to IRI. Thus a subgroup of severely diabetic adrenalectomized STZ obese mice with very low IRI (20 microU/ml) had body fat contents and fat-free masses equal to those of weight-matched lean mice. The data suggest that hypercorticoidism rather than hyperinsulinemia is largely responsible for obesity in ob/ob mice. However, in the absence of adrenal glucocorticoids, or perhaps with just their normalization, hyperinsulinemia appears necessary for maintaining excessive body energy stores.

Energy expenditure and requirement while climbing above 6,000 m

1996 ◽  
Vol 81 (3) ◽  
pp. 1306-1311 ◽  
Author(s):  
S. M. Pulfrey ◽  
P. J. Jones
Keyword(s):  
Energy Expenditure ◽  
Energy Requirement ◽  
Barometric Pressure ◽  
Skinfold Thickness ◽  
Doubly Labeled Water ◽  
Dietary Record ◽  
Extreme Altitude ◽  
Energy Stores ◽  
Daily Energy ◽  
Body Energy

Humans survive the low barometric pressure of altitudes above 6,000 m only by making a complex series of adaptations. However, the effects of such adaptations on energy metabolism have not been widely studied. To determine daily energy requirement at extreme altitude, energy expenditure (EE) was measured by doubly labeled water (DLW) and energy intake-balance (IB) methods in five men and one woman while climbing between 5,900 and 8,046 m over a 7-day period. Energy intakes were determined by dietary record (13.8 +/- 2.0 MJ/day). Change in body energy stores, estimated from differences in body weight, skinfold thickness, limb circumference, and isotope-dilution techniques, was -5.1 +/- 1.6 MJ/day. DLW (19.4 +/- 1.2 MJ/day) and IB (18.9 +/- 2.7 MJ/day) measurements of EE provided similar estimates of group mean EE. These results suggest that IB and DLW techniques can yield comparable estimates of group mean EE at extreme altitude. It is concluded that problems of meeting energy requirements while climbing at extreme altitude are related to energy intakes amounting to only roughly 70% of EE.

scholarly journals The Role of Leptin in the Development of Energy Homeostatic Systems and the Maintenance of Body Weight

2021 ◽  
Vol 12 ◽  
Author(s):  
Charles A. LeDuc ◽  
Alicja A. Skowronski ◽  
Michael Rosenbaum
Keyword(s):  
Neural Systems ◽  
Future Research ◽  
Intrauterine Environment ◽  
Neuronal Circuitry ◽  
Leptin Signaling ◽  
Energy Stores ◽  
Pleiotropic Gene ◽  
Nutritional Environment ◽  
Body Energy

LEP is a pleiotropic gene and the actions of leptin extend well beyond simply acting as the signal of the size of adipose tissue stores originally proposed. This is a discussion of the multi-system interactions of leptin with the development of the neural systems regulating energy stores, and the subsequent maintenance of energy stores throughout the lifespan. The prenatal, perinatal, and later postnatal effects of leptin on systems regulating body energy stores and on the energy stores themselves are heavily influenced by the nutritional environment which leptin exposure occurs. This review discusses the prenatal and perinatal roles of leptin in establishing the neuronal circuitry and other systems relevant to the adiposity set-point (or “threshold”) and the role of leptin in maintaining weight homeostasis in adulthood. Therapeutic manipulation of the intrauterine environment, use of leptin sensitizing agents, and identification of specific cohorts who may be more responsive to leptin or other means of activating the leptin signaling pathway are ripe areas for future research.

scholarly journals Energy efficient synaptic plasticity

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Ho Ling Li ◽  
Mark CW van Rossum
Keyword(s):  
Synaptic Plasticity ◽  
Energy Efficient ◽  
Back Propagation ◽  
Neural Computation ◽  
Metabolic Efficiency ◽  
Multiple Forms ◽  
Energetic Costs ◽  
Metabolic Costs ◽  
Synaptic Tagging And Capture ◽  
Stable Forms

Many aspects of the brain’s design can be understood as the result of evolutionary drive toward metabolic efficiency. In addition to the energetic costs of neural computation and transmission, experimental evidence indicates that synaptic plasticity is metabolically demanding as well. As synaptic plasticity is crucial for learning, we examine how these metabolic costs enter in learning. We find that when synaptic plasticity rules are naively implemented, training neural networks requires extremely large amounts of energy when storing many patterns. We propose that this is avoided by precisely balancing labile forms of synaptic plasticity with more stable forms. This algorithm, termed synaptic caching, boosts energy efficiency manifold and can be used with any plasticity rule, including back-propagation. Our results yield a novel interpretation of the multiple forms of neural synaptic plasticity observed experimentally, including synaptic tagging and capture phenomena. Furthermore, our results are relevant for energy efficient neuromorphic designs.

Doubly labeled water measurement of human energy expenditure during strenuous exercise

1991 ◽  
Vol 71 (1) ◽  
pp. 16-22 ◽  
Author(s):  
R. W. Hoyt ◽  
T. E. Jones ◽  
T. P. Stein ◽  
G. W. McAninch ◽  
H. R. Lieberman ◽  
...  
Keyword(s):  
Food Intake ◽  
Isotope Dilution ◽  
Cold Weather ◽  
Strenuous Exercise ◽  
Control Group ◽  
Doubly Labeled Water ◽  
Energy Stores ◽  
Energy Store ◽  
Body Energy ◽  
Field Exercise

The energy expenditures (EE) of 23 adult male Marines were measured during a strenuous 11-day cold-weather field exercise at 2,200- to 2,550-m elevation by both doubly labeled water (2H2 18O, DLW) and intake balance methods. The DLW EE calculations were corrected for changes in baseline isotopic abundances in a control group that did not receive 2H2 18O. Intake balance EE was estimated from the change in body energy stores and food intake. Body energy-store changes were calculated from anthropometric [-1,574 +/- 144 (SE) kcal/day] and isotope dilution (-1,872 +/- 293 kcal/day) measurements made before and after the field exercise. The subjects kept daily logbook records of ration consumption (3,132 +/- 165 kcal/day). Mean DLW EE (4,919 +/- 190 kcal/day) did not differ significantly from intake balance EE estimated from food intake and either anthropometric (4,705 +/- 181 kcal/day) or isotope dilution (5,004 +/- 240 kcal/day) estimates of the change in body energy stores. The DLW method can be used with at least the same degree of confidence as the intake balance method to measure the EE of active free-living humans.

scholarly journals Does foraging mode affect metabolic responses to feeding? A study of pygopodid lizards

2013 ◽  
Vol 59 (5) ◽  
pp. 618-625 ◽  
Author(s):  
Michael Wall ◽  
Michael B. Thompson ◽  
Richard Shine
Keyword(s):  
Specific Dynamic Action ◽  
Metabolic Responses ◽  
Metabolic Rates ◽  
Energetic Costs ◽  
Foraging Mode ◽  
Organismal Biology ◽  
Lower Standard ◽  
The Common ◽  
Active Forager ◽  
Ambush Foraging

Abstract Foraging mode (ambush vs. active) profoundly affects many aspects of organismal biology, including metabolic rates and their relationship with food intake. Previous studies on snakes suggest that ambushers tend to have lower standard metabolic rates (SMR) and higher energetic costs of digestion and assimilation of prey (specific dynamic action, or SDA) than do active foragers. However, phylogenetic considerations may be at least partly responsible for such patterns, as foraging mode is strongly conserved evolutionarily and most SDA studies have focused on species from only two lineages of ambush foragers (pythonid and viperid snakes) and one lineage of active foragers (colubrid snakes). We sought to deconfound the effects of phylogeny and foraging mode, investigating SMR and SDA in two closely related pygopodid lizards, the common scaly-foot Pygopus lepidopodus (active forager) and Burton’s legless lizard Lialis burtonis (ambush forager). Consistent with the pattern seen in snakes, L. burtonis exhibits a significantly lower SMR and a higher SDA than does P. lepidopodus. The magnitude of SDA in L. burtonis is comparable to that of some pythons and vipers, providing yet more evidence for the remarkable convergence between this species and ambush-foraging snakes.

Assessment of energy status in hill sheep using computer tomography

1999 ◽  
Vol 1999 ◽  
pp. 103-103
Author(s):  
M.J. Young ◽  
A. Leboulanger ◽  
K.A. McLean ◽  
J. Fraser ◽  
J. Conington ◽  
...  
Keyword(s):  
Computer Tomography ◽  
Cost Effective ◽  
Harsh Environments ◽  
Energy Reserves ◽  
Energy Status ◽  
X Ray ◽  
Fat Depots ◽  
Energy Stores ◽  
Tissue Size ◽  
Body Energy

Breeding leaner sheep is a desirable goal provided reductions in fatness do not compromise survival and productivity, particularly in harsh environments. Whether some energy stores are more labile than others, the internal fat depots in particular, is not clear. Genetic variation in this trait could be usefully exploited in hill sheep where carcass fat is undesirable but energy reserves are important. Patterns of change in body energy stores need to be examined to determine when it is best to assess energy stores in animals. X-ray computer tomography (CT) provides a means to examine depletion and repletion of body energy but scans are not cheap. In order to use CT in a cost effective way, a number of variables need to be assessed from just a few scans. This report presents results of a study designed to define such a scanning approach in terms of which scans were most informative and which produced most accurate predictions of tissue size.

The metabolic basis of dual periodicity of feeding in rats

1981 ◽  
Vol 4 (4) ◽  
pp. 561-575 ◽  
Author(s):  
Jacques Le Magnen
Keyword(s):  
Energy Levels ◽  
Ventromedial Hypothalamus ◽  
Glucose Uptake Rate ◽  
Fat Mobilization ◽  
Energy Stores ◽  
The Difference ◽  
Metabolic Basis ◽  
Body Energy ◽  
Small Capacity

AbstractThis article examines how the depletion and replenishment of various energy stores give rise to periodic eating and how constant body-energy levels are maintained over time.Measures of the energy expended throughout the 24-hour feeding pattern in rats indicate that two different energy stores (one of small capacity and one of large) determine two superimposed feeding periodicities: one from meal to meal (prandial), the other from day to night (nycthemeral). The article reviews how experimental overrepletion or overdepletion of gastrointestinal content, blood glucose, or body fats affect food intake. These data suggest that gastrointestinal content determines both meal size and meal-to-meal periodicity. Other evidence indicates that glucose uptake rate in tissues, which is modulated by fat synthesis and fat mobilization, affects the periodic onset of feeding and the difference between nocturnal and diurnal postprandial satiety.There follows an examination of the neuroendocrine bases for the interacting mechanisms governing energy input and output balance and of the role of the ventromedial hypothalamus in body-fat regulation and the lateral hypothalamus in feeding.

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