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Knut Schmidt-Nielsen

Bio: Knut Schmidt-Nielsen is an academic researcher from Duke University. The author has contributed to research in topics: Salt gland & Psammomys. The author has an hindex of 53, co-authored 112 publications receiving 13870 citations. Previous affiliations of Knut Schmidt-Nielsen include Colorado State University & University of Pennsylvania.


Papers
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Book
01 Jan 1984
TL;DR: The importance of animal size in animal function is discussed in this paper, where it is shown that physical laws are equally important, for they determine rates of diffusion and heat transfer, transfer of force and momentum, strength of structures, the dynamics of locomotion, and other aspects of the functioning of animal bodies.
Abstract: This book is about the importance of animal size. We tend to think of animal function in chemical terms and talk of water, salts, proteins, enzymes, oxygen, energy, and so on. We should not forget, however, that physical laws are equally important, for they determine rates of diffusion and heat transfer, transfer of force and momentum, the strength of structures, the dynamics of locomotion, and other aspects of the functioning of animal bodies. Physical laws provide possibilities and opportunities for an organism, yet they also impose constraints, setting limits to what is physically possible. This book aims to give an understanding of these rules because of their profound implications when we deal with animals of widely different size and scale. The reader will find that the book raises many questions. Remarkable and puzzling information makes it read a little like a detective story, but the last chapter, instead of giving the final solution, neither answers all questions nor provides one great unifying principle.

2,736 citations

Book
01 Jan 1962
TL;DR: In this article, the authors present an overview of the physiological properties of the human body, including Oxygen, Respiration, Food and Energy, Water and osmotic regulation, control and integration, and Hormone control.
Abstract: Preface Part I. Oxygen: 1. Respiration 2. Blood 3. Circulation Part II. Food and Energy: 4. Food and fuel 5. Energy metabolism Part III. Temperature: 6. Temperature effects 7. Temperature regulation Part IV. Water: 8. Water and osmotic regulation 9. Excretion Part V. Movement, Information, Integration: 10. Movement, muscle, biomechanics 11. Control and integration 12. Hormonal control 13. Information and senses Appendices Index.

2,520 citations

Book
01 Jan 1979
TL;DR: Bargaining with reading habit is no need as mentioned in this paper, reading is not kind of something sold that you can take or not, it is a thing that will change your life to life better.
Abstract: Bargaining with reading habit is no need. Reading is not kind of something sold that you can take or not. It is a thing that will change your life to life better. It is the thing that will give you many things around the world and this universe, in the real world and here after. As what will be given by this adaptation to desert environment a study on the jerboa rat and man, how can you bargain with the thing that has many benefits for you?

524 citations

Journal ArticleDOI
TL;DR: The rectal temperature of normal healthy camels at rest may vary from about 34°C to more than 40°C, and the diurnal variations in the winter are usually in the order of 2°C.
Abstract: The rectal temperature of normal healthy camels at rest may vary from about 34°C to more than 40°C. Diurnal variations in the winter are usually in the order of 2°C. In summer the diurnal variation...

300 citations


Cited by
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Journal ArticleDOI
01 Jul 2004-Ecology
TL;DR: This work has developed a quantitative theory for how metabolic rate varies with body size and temperature, and predicts how metabolic theory predicts how this rate controls ecological processes at all levels of organization from individuals to the biosphere.
Abstract: Metabolism provides a basis for using first principles of physics, chemistry, and biology to link the biology of individual organisms to the ecology of populations, communities, and ecosystems. Metabolic rate, the rate at which organisms take up, transform, and expend energy and materials, is the most fundamental biological rate. We have developed a quantitative theory for how metabolic rate varies with body size and temperature. Metabolic theory predicts how metabolic rate, by setting the rates of resource uptake from the environment and resource allocation to survival, growth, and reproduction, controls ecological processes at all levels of organization from individuals to the biosphere. Examples include: (1) life history attributes, including devel- opment rate, mortality rate, age at maturity, life span, and population growth rate; (2) population interactions, including carrying capacity, rates of competition and predation, and patterns of species diversity; and (3) ecosystem processes, including rates of biomass production and respiration and patterns of trophic dynamics. Data compiled from the ecological literature strongly support the theoretical predictions. Even- tually, metabolic theory may provide a conceptual foundation for much of ecology, just as genetic theory provides a foundation for much of evolutionary biology.

6,017 citations

Journal ArticleDOI
04 Apr 1997-Science
TL;DR: The model provides a complete analysis of scaling relations for mammalian circulatory systems that are in agreement with data and predicts structural and functional properties of vertebrate cardiovascular and respiratory systems, plant vascular systems, insect tracheal tubes, and other distribution networks.
Abstract: Allometric scaling relations, including the 3/4 power law for metabolic rates, are characteristic of all organisms and are here derived from a general model that describes how essential materials are transported through space-filling fractal networks of branching tubes. The model assumes that the energy dissipated is minimized and that the terminal tubes do not vary with body size. It provides a complete analysis of scaling relations for mammalian circulatory systems that are in agreement with data. More generally, the model predicts structural and functional properties of vertebrate cardiovascular and respiratory systems, plant vascular systems, insect tracheal tubes, and other distribution networks.

4,272 citations

Journal ArticleDOI
TL;DR: The peak age of onset for many psychiatric disorders is adolescence, a time of remarkable physical and behavioural changes and answers to these questions might enable the understanding of mental health during adolescence.
Abstract: The peak age of onset for many psychiatric disorders is adolescence, a time of remarkable physical and behavioural changes. The processes in the brain that underlie these behavioural changes have been the subject of recent investigations. What do we know about the maturation of the human brain during adolescence? Do structural changes in the cerebral cortex reflect synaptic pruning? Are increases in white-matter volume driven by myelination? Is the adolescent brain more or less sensitive to reward? Finding answers to these questions might enable us to further our understanding of mental health during adolescence.

2,436 citations

Journal ArticleDOI
04 Mar 1989-BMJ
TL;DR: In national samples of 10 year olds and adults in Britain systolic blood pressure was inversely related to birth weight, which suggests that the intrauterine environment influences blood pressure during adult life.
Abstract: In national samples of 9921 10 year olds and 3259 adults in Britain systolic blood pressure was inversely related to birth weight. The association was independent of gestational age and may therefore be attributed to reduced fetal growth. This suggests that the intrauterine environment influences blood pressure during adult life. It is further evidence that the geographical differences in average blood pressure and mortality from cardiovascular disease in Britain partly reflect past differences in the intrauterine environment. Within England and Wales 10 year olds living in areas with high cardiovascular mortality were shorter and had higher resting pulse rates than those living in other areas. Their mothers were also shorter and had higher diastolic blood pressures. This suggests that there are persisting geographical differences in the childhood environment that predispose to differences in cardiovascular mortality.

2,233 citations

Journal ArticleDOI
TL;DR: 3D printed rigid filament networks of carbohydrate glass are used as a cytocompatible sacrificial template in engineered tissues containing living cells to generate cylindrical networks which could be lined with endothelial cells and perfused with blood under high-pressure pulsatile flow.
Abstract: In the absence of perfusable vascular networks, three-dimensional (3D) engineered tissues densely populated with cells quickly develop a necrotic core [1]. Yet the lack of a general approach to rapidly construct such networks remains a major challenge for 3D tissue culture [2–4]. Here, we 3D printed rigid filament networks of carbohydrate glass, and used them as a cytocompatible sacrificial template in engineered tissues containing living cells to generate cylindrical networks which could be lined with endothelial cells and perfused with blood under high-pressure pulsatile flow. Because this simple vascular casting approach allows independent control of network geometry, endothelialization, and extravascular tissue, it is compatible with a wide variety of cell types, synthetic and natural extracellular matrices (ECMs), and crosslinking strategies. We also demonstrated that the perfused vascular channels sustained the metabolic function of primary rat hepatocytes in engineered tissue constructs that otherwise exhibited suppressed function in their core.

1,577 citations