scholarly journals Construction of energy landscapes can clarify the movement and distribution of foraging animals

2011 ◽  
Vol 279 (1730) ◽  
pp. 975-980 ◽  
Author(s):  
Rory P. Wilson ◽  
Flavio Quintana ◽  
Victoria J. Hobson
Keyword(s):  
Energy Expenditure ◽  
Optimal Foraging ◽  
Energy Landscape ◽  
Movement Ecology ◽  
Net Energy ◽  
Energy Landscapes ◽  
Breeding Colony ◽  
Free Living ◽  
Net Energy Gain

Variation in the physical characteristics of the environment should impact the movement energetics of animals. Although cognizance of this may help interpret movement ecology, determination of the landscape-dependent energy expenditure of wild animals is problematic. We used accelerometers in animal-attached tags to derive energy expenditure in 54 free-living imperial cormorants Phalacrocorax atriceps and construct an energy landscape of the area around a breeding colony. Examination of the space use of a further 74 birds over 4 years showed that foraging areas selected varied considerably in distance from the colony and water depth, but were characterized by minimal power requirements compared with other areas in the available landscape. This accords with classic optimal foraging concepts, which state that animals should maximize net energy gain by minimizing costs where possible and show how deriving energy landscapes can help understand how and why animals distribute themselves in space.

Adaptations to prolonged fasting in free-living weaned gray seal pups

1991 ◽  
Vol 260 (2) ◽  
pp. R267-R272 ◽  
Author(s):  
J. J. Reilly
Keyword(s):  
Energy Expenditure ◽  
Tritiated Water ◽  
Urinary Output ◽  
Turnover Rates ◽  
Prolonged Fasting ◽  
Water Turnover ◽  
Free Living ◽  
Gray Seal ◽  
Composition Changes

The water and energy metabolism of 12 free-living gray seal pups during their postweaning fast was investigated using tritiated water for determination of rates of energy expenditure and water turnover and changes in body composition. Changes in serum composition and urinary output were also measured. The duration of the postweaning fast ranged from 10 to greater than 28 days. The mean daily energy expenditure of pups was 12.0 +/- 1.0 (SE) MJ, equivalent to 2.7 times the basal metabolic rate predicted from M. Kleiber (The Fire of Life. Huntington, NY: Krieger, 1975). On average, lipid catabolism provided 94% of the energy used. Water-turnover rates were lower than predicted from C. R. Richmond, W. H. Langham, and T. T. Trujillo (J. Cell. Comp. Physiol. 59: 45-55, 1962). Urinary output of water and solute were also low, and these declined as the fast progressed. Although pups were in negative water balance, there was no evidence that they experience dehydration during the post-weaning fast. The principal adaptations to prolonged fasting in weaned gray seals are, therefore, lowering of field metabolic and water-turnover rate and reliance on stored lipid as fuel.

scholarly journals Nanomaterials - what energy landscapes can tell us

2015 ◽  
Vol 9 (3) ◽  
pp. 157-168 ◽  
Author(s):  
Johann Schön
Keyword(s):  
Thin Films ◽  
Structural Analysis ◽  
Sapphire Substrate ◽  
Energy Landscape ◽  
Nano Materials ◽  
Energy Landscapes ◽  
Crystalline Materials ◽  
Chemical Systems ◽  
Nano Size

Nanomaterials bridge the gaps between crystalline materials, thin films, and molecules, and are of great importance in the design of new classes of materials, since the existence of many modifications of a nano-object for the same overall composition allows us to tune the properties of the nanomaterial. However, the structural analysis of nano-size systems is often difficult and their structural stability is frequently relatively low. Thus, a study of their energy landscape is needed to determine or predict possible structures, and analyse their stability, via the determination of the minima on the landscape and the generalized barriers separating them. In this contribution, we introduce the major concepts of energy landscapes for chemical systems, and present summaries of four applications to nano-materials: a MgO monolayer on a sapphire substrate, possible quasitwo- dimensional carbon-silicon networks, the ab initio energy landscape of Cu4Ag4-clusters, and the possible arrangements of ethane molecules on an ideally smooth substrate.

Adolescent athletes and nutrition – analysis of two groups of children

2020 ◽  
pp. 1-6
Author(s):  
Tatyana Dzimbova
Keyword(s):  
Energy Expenditure ◽  
Energy Intake ◽  
Eating Habits ◽  
Energy Deficit ◽  
Young Athletes ◽  
Adolescent Athletes ◽  
Basketball Players ◽  
Calcium Magnesium ◽  
The Right

Introduction. Proper nutrition is crucial for child and adolescent athletes to maintain growth and development and to achieveoptimal results in sports. It is very important to balance the energy expenditure with the energy intake in order to prevent the energy deficit or excess.Materials and methods. Subjects involved in two different sports participated in the study: 13 gymnasts (age 13.8 ± 4.1 years, height 153.4 ± 11.3 cm, weight 47.1 ± 10.5 kg) and 15 basketball players (age 15.5 ± 1.1 years, height 176.7 ± 7.9 cm, weight 65.2 ± 10.7 kg). Determination of total energy expenditure was made by prediction equations. The subjects maintained a food records for 5 consecutive days, which were processed in the ASA24 system of the NCI. Results and discussion. Energy intake in both groups is sufficient to meet the daily needs, development of young athletes andprovide the energy needed in training. The intake of three minerals (calcium, magnesium and potassium) and three vitamins (D, E and A) was lower than recommended values in both groups.Conclusion. As a result of the busy schedule of adolescent athletes, their main meals are out of home, and the proportion of highly processed foods containing small amounts of important vitamins and minerals is high. The main recommendations include dairy products, fruits, vegetables and whole grains. The idea behind the changes is to give young athletes the right diet and the right eating habits.

scholarly journals Universally bistable shells with nonzero Gaussian curvature for two-way transition waves

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nikolaos Vasios ◽  
Bolei Deng ◽  
Benjamin Gorissen ◽  
Katia Bertoldi
Keyword(s):  
Gaussian Curvature ◽  
Energy Landscape ◽  
Propagation Distance ◽  
Energy Landscapes ◽  
Bending Energy ◽  
Nonlinear Dynamic Response ◽  
One Dimensional ◽  
Doubly Curved Shells ◽  
Doubly Curved ◽  
The Waves

AbstractMulti-welled energy landscapes arising in shells with nonzero Gaussian curvature typically fade away as their thickness becomes larger because of the increased bending energy required for inversion. Motivated by this limitation, we propose a strategy to realize doubly curved shells that are bistable for any thickness. We then study the nonlinear dynamic response of one-dimensional (1D) arrays of our universally bistable shells when coupled by compressible fluid cavities. We find that the system supports the propagation of bidirectional transition waves whose characteristics can be tuned by varying both geometric parameters as well as the amount of energy supplied to initiate the waves. However, since our bistable shells have equal energy minima, the distance traveled by such waves is limited by dissipation. To overcome this limitation, we identify a strategy to realize thick bistable shells with tunable energy landscape and show that their strategic placement within the 1D array can extend the propagation distance of the supported bidirectional transition waves.

Changes in 24-h substrate oxidation in older and younger men in response to exercise

2007 ◽  
Vol 103 (5) ◽  
pp. 1576-1582 ◽  
Author(s):  
Edward L. Melanson ◽  
William T. Donahoo ◽  
Gary K. Grunwald ◽  
Robert Schwartz
Keyword(s):  
Fatty Acids ◽  
Energy Expenditure ◽  
Free Fatty Acids ◽  
Plasma Free Fatty Acid ◽  
Fat Oxidation ◽  
Substrate Oxidation ◽  
Net Energy ◽  
Younger Men ◽  
Response To Exercise ◽  
Time Point

The purpose of this study was to compare 24-h substrate oxidation in older (OM; 60–75 yr, n = 7) and younger (YM; 20–30 yr, n = 7) men studied on sedentary day (Con) and on a day with exercise (Ex; net energy expenditure = 300 kcal). Plasma glucose and free fatty acids were also measured at several time points during the 24-h measurement. Weight was not different in OM and YM (means ± SD; 84.8 ± 16.9 vs. 81.4 ± 10.4 kg, respectively), although percent body fat was slightly higher in OM (25.9 ± 3.5 vs. 21.9 ± 9.7%; P = 0.17).Values of 24-h energy expenditure did not differ in OM and YM on the Con (means ± SE; 2,449 ± 162 vs. 2,484 ± 104 kcal/day, respectively) or Ex (2,902 ± 154 vs. 2,978 ± 122 kcal/day) days. Under both conditions, 24-h respiratory quotient was significantly lower and fat oxidation significantly higher in OM. Glucose concentrations were not different at any time point, but plasma free fatty acid concentrations were higher in OM, particularly following meals. Thus, under these controlled conditions, 24-h fat oxidation was not reduced and was in fact greater in OM. We speculate that differences in the availability of circulating free fatty acids in the postprandial state contributed to the observed differences in 24-h fat oxidation in OM and YM.

Determination of total energy expenditure, resting metabolic rate and physical activity in lean and overweight people

1997 ◽  
Vol 36 (4) ◽  
pp. 310-312 ◽  
Author(s):  
F. Thielecke ◽  
J. Möseneder ◽  
A. Kroke ◽  
K. Klipstein-Grobusch ◽  
H. Boeing ◽  
...  
Keyword(s):  
Physical Activity ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Total Energy ◽  
Resting Metabolic Rate ◽  
Total Energy Expenditure ◽  
Overweight People

Validation of the BIOPAC indirect calorimeter for determining resting energy expenditure in healthy free-living older people

2009 ◽  
Vol 29 (8) ◽  
pp. 531-541 ◽  
Author(s):  
Kerstin Khalaj-Hedayati ◽  
Anja Bosy-Westphal ◽  
Manfred J. Müller ◽  
Manuela Dittmar
Keyword(s):  
Energy Expenditure ◽  
Older People ◽  
Resting Energy Expenditure ◽  
Free Living ◽  
Resting Energy
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