Abstract：
:The amount of energy used to run a mile is nearly the same whether it is run at top speed or at a leisurely pace (although it is used more rapidly at the higher speed). This puzzling independence of energy cost and speed is found generally among running animals, although, on a per gram basis, cost is much higher for smaller animals. Running involves little work against the environment; work is done by muscles and tendons to lift and accelerate the body and limbs. Some of the work is recovered from muscle-tendon springs without metabolic cost and work rate does not parallel metabolic rate with either speed or size. Regardless of the amount of work muscles do, they must be activated and develop force to support the weight of the body. Load-carrying experiments have shown that the cost of supporting an extra newton of load is the same as the weight-specific cost of running. Size differences in cost are proportional to stride frequency at equivalent speeds, suggesting that the time available for developing force is important in determining cost. We report a simple inverse relationship between the rate of energy used for running and the time the foot applies force to the ground during each stride. These results support the hypothesis that it is primarily the cost of supporting the animal's weight and the time course of generating this force that determines the cost of running.
journal_name
Naturejournal_title
Natureauthors
Kram R,Taylor CRdoi
10.1038/346265a0subject
Has Abstractpub_date
1990-07-19 00:00:00pages
265-7issue
6281eissn
0028-0836issn
1476-4687journal_volume
346pub_type
杂志文章相关文献
NATURE文献大全abstract：: ...
journal_title：Nature
pub_type： 新闻
doi：10.1038/d41586-018-07283-3
更新日期：2018-11-01 00:00:00
abstract：:Phylogenetic analysis of early tetrapod evolution has resulted in a consensus across diverse data sets in which the tetrapod stem group is a relatively homogenous collection of medium- to large-sized animals showing a progressive loss of 'fish' characters as they become increasingly terrestrial, whereas the crown grou...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature22966
更新日期：2017-06-29 00:00:00
abstract：:Neurons in the developing rodent cortex are generated from radial glial cells that function as neural stem cells. These epithelial cells line the cerebral ventricles and generate intermediate progenitor cells that migrate into the subventricular zone (SVZ) and proliferate to increase neuronal number. The developing hu...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature08845
更新日期：2010-03-25 00:00:00
abstract：:Self-incompatibility in flowering plants is often controlled by a single nuclear gene (the S-gene) having several alleles. This gene prevents fertilization by self-pollen or by pollen bearing either of the two S-alleles expressed in the style. Sequence analysis shows that three alleles of the S gene of Nicotiana alata...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/342955a0
更新日期：1989-12-21 00:00:00
abstract：:A T-cell-mediated immune response is initiated by the T-cell receptor (TCR) interacting with peptide-bound major histocompatibility complex (pMHC) on an infected cell. The mechanism by which this interaction triggers intracellular phosphorylation of the TCR, which lacks a kinase domain, remains poorly understood. Here...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature11220
更新日期：2012-07-05 00:00:00
abstract：:The distribution of fitness effects of protein mutations is still unknown. Of particular interest is whether accumulating deleterious mutations interact, and how the resulting epistatic effects shape the protein's fitness landscape. Here we apply a model system in which bacterial fitness correlates with the enzymatic ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature05385
更新日期：2006-12-14 00:00:00
abstract：:To understand the molecular basis of microtubule-associated motility during mitosis, the mechanochemical factors that generate the relevant motile force must be identified. Myosin, the ATPase that interacts with actin to produce the force for muscle contraction and other forms of cell motility, is believed to be invol...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/318483a0
更新日期：1985-12-05 00:00:00
abstract：:The collagens represent an interesting example of a structurally related but genetically distinct family of proteins. Type I, the most abundant of the vertebrate collagens, comprises two pro alpha 1(I) chains and one pro alpha 2(I) chain, each containing terminal propeptides and a central domain of 338 (Gly, X, Y) rep...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/310337a0
更新日期：1984-07-26 00:00:00
abstract：:To understand the processes that regulate the abundance and persistence of wild populations is a fundamental goal of ecology and a prerequisite for the management of living resources. Variable abundance data, however, make the demonstration of regulation processes challenging. A previously overlooked aspect in underst...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature06605
更新日期：2008-03-20 00:00:00
abstract：:Sensory transduction in taste and olfaction, the principal chemical senses, seems to be mediated by membrane-associated proteins on the apical surfaces of the respective receptor cells. The recent isolation and characterization of soluble 'odorant-binding proteins' secreted from the nasal glands of rat, cow and frog, ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/343366a0
更新日期：1990-01-25 00:00:00
abstract：:Volcanic eruptions contribute to climate variability, but quantifying these contributions has been limited by inconsistencies in the timing of atmospheric volcanic aerosol loading determined from ice cores and subsequent cooling from climate proxies such as tree rings. Here we resolve these inconsistencies and show th...
journal_title：Nature
pub_type： 历史文章,杂志文章
doi：10.1038/nature14565
更新日期：2015-07-30 00:00:00
abstract：:Current human immunodeficiency virus-1 (HIV-1) vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in approximately 20% of HIV-1-infected individuals, and details of their generation could provide a blueprint for effective vaccination. Here we report the isola...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature12053
更新日期：2013-04-25 00:00:00
abstract：:The species diversity of natural communities is often strongly related to their productivity. The pattern of this relationship seems to vary: diversity is known to increase monotonically with productivity, to decrease monotonically with productivity, and to be unimodally related to productivity, with maximum diversity...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/35020060
更新日期：2000-08-03 00:00:00
abstract：:Bilingual individuals need effective mechanisms to prevent interference from one language while processing material in the other. Here we show, using event-related brain potentials and functional magnetic resonance imaging (fMRI), that words from the non-target language are rejected at an early stage before semantic a...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/4151026a
更新日期：2002-02-28 00:00:00
abstract：:Gut commensal microbes shape the mucosal immune system by regulating the differentiation and expansion of several types of T cell. Clostridia, a dominant class of commensal microbe, can induce colonic regulatory T (Treg) cells, which have a central role in the suppression of inflammatory and allergic responses. Howeve...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature12721
更新日期：2013-12-19 00:00:00
abstract：:How diverse cell fates and complex forms emerge and feed back to each other to sculpt functional organs remains unclear. In the developing heart, the myocardium transitions from a simple epithelium to an intricate tissue that consists of distinct layers: the outer compact and inner trabecular layers. Defects in this p...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-020-2946-9
更新日期：2020-12-01 00:00:00
abstract：:Viable tumour-derived epithelial cells (circulating tumour cells or CTCs) have been identified in peripheral blood from cancer patients and are probably the origin of intractable metastatic disease. Although extremely rare, CTCs represent a potential alternative to invasive biopsies as a source of tumour tissue for th...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature06385
更新日期：2007-12-20 00:00:00
abstract：:The structure of foot-and-mouth disease virus has been determined at close to atomic resolution by X-ray diffraction without experimental phase information. The virus shows similarities with other picornaviruses but also several unique features. The canyon or pit found in other picornaviruses is absent; this has impor...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/337709a0
更新日期：1989-02-23 00:00:00
abstract：:Pinocytosis and membrane ruffling are among the earliest and most dramatic cellular responses to stimulation by growth factors or other mitogens. The small Ras-related G proteins Rho and Rac have a regulatory role in membrane ruffling and activated Rho has been shown to stimulate pinocytosis when microinjected into Xe...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/382177a0
更新日期：1996-07-11 00:00:00
abstract：:Blood coagulation can be initiated when factor VII or VIIa, a plasma protease, binds to its essential cofactor, tissue factor (TF), and proteolytically activates factors IX and X, triggering a cascade of events which eventually leads to the formation of thrombin and a fibrin clot. Plasma contains a lipoprotein-associa...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/338518a0
更新日期：1989-04-06 00:00:00
abstract：:Black holes become visible when they accrete gas, a common source of which is a close stellar companion. The standard theory for this process (invoking a 'thin accretion disk') does not explain some spectacular phenomena associated with these systems, such as their X-ray variability and relativistic outflows, indicati...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/35102515
更新日期：2001-11-08 00:00:00
abstract：:Schistosoma japonicum is a parasitic flatworm that causes human schistosomiasis, which is a significant cause of morbidity in China and the Philippines. Here we present a draft genomic sequence for the worm. The genome provides a global insight into the molecular architecture and host interaction of this complex metaz...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature08140
更新日期：2009-07-16 00:00:00
abstract：:The neurotransmitter dopamine has been demonstrated by biochemical, histochemical and immunocytochemical techniques to be unevenly distributed in the mammalian central nervous system. DARPP-32 (dopamine- and cyclic-AMP-regulated phosphoprotein of molecular weight 32,000) is a neuronal phosphoprotein that displays a re...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/310503a0
更新日期：1984-08-09 00:00:00
abstract：:The reliable detection of single quantum particles has revolutionized the field of quantum optics and quantum information processing. For several years, researchers have aspired to extend such detection possibilities to larger-scale, strongly correlated quantum systems in order to record in situ images of a quantum fl...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature09378
更新日期：2010-09-02 00:00:00
abstract：:Several organisms have evolved the ability to measure daylength, or photoperiod, allowing them to adjust their development in anticipation of annual seasonal changes. Daylength measurement requires the integration of temporal information, provided by the circadian system, with light/dark discrimination, initiated by s...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature00996
更新日期：2002-09-19 00:00:00
abstract：:Emerging infectious diseases present a formidable challenge to the conservation of native species in the twenty-first century. Diseases caused by introduced pathogens have had large impacts on species abundances, including the American chestnut, Hawaiian bird species and many amphibians. Changes in host population siz...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature05829
更新日期：2007-06-07 00:00:00
abstract：:Acetylcholine and dopamine are key neurotransmitters in the extrapyramidal motor system, where they are thought to lie in a 'functional balance' brought about by interactions between the terminals of the dopamine-containing nigrostriatal tract and the cholinergic interneurones of the striatum. The precise nature of th...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/323625a0
更新日期：1986-10-16 00:00:00
abstract：:How environmental cues regulate adult stem cell and cancer cell activity through surface receptors is poorly understood. Angiopoietin-like proteins (ANGPTLs), a family of seven secreted glycoproteins, are known to support the activity of haematopoietic stem cells (HSCs) in vitro and in vivo. ANGPTLs also have importan...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature11095
更新日期：2012-05-30 00:00:00
abstract：:Rous sarcoma virus (RSV) is an acutely oncogenic avian retrovirus which induces sarcomas in animals and transforms fibroblasts in cell culture. Genetic analysis indicates that the viral src gene (v-src) mediates neoplastic transformation. The product of v-src is a 60,000 molecular weight (MW) phosphoprotein (pp60v-src...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/302837a0
更新日期：1983-04-28 00:00:00
abstract：:When mountains form through the collision of lithospheric plates, uplift of the Earth's surface is accompanied by thickening of the crust, and the buoyancy of these deep crustal roots (relative to the surrounding mantle) is thought to contribute to the support of mountain topography. Once active tectonism ceases, cont...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature00855
更新日期：2002-06-27 00:00:00
