Terminology of Relative Growth

Huxley, Julian; Teissier, Georges

doi:10.1038/137780b0

Cited by 589 publications

(388 citation statements)

References 5 publications

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“…Crown diameter was regressed against stem diameter using an allometric power relation (Huxley and Teissier 1936): CD = CD int dbh CDslo , where CD is crown diameter (m), CD int is the crown diameter intercept (for trees of 1-cm dbh) and CD slo represents the crown diameter ''slope'' (i.e., the diameter exponent or scaling component). The power relation for crown length is CL = CL int dbh CLslo , where CL int represents the crown length intercept (for trees of 1-cm dbh) and CL slo is the crown length ''slope'' (i.e., the diameter exponent or scaling component).…”

Section: Discussionmentioning

confidence: 99%

Architecture of Iberian canopy tree species in relation to wood density, shade tolerance and climate

et al. 2012

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Tree architecture has important consequences for tree performance as it determines resource capture, mechanical stability and dominance over competitors. We analyzed architectural relationships between stem and crown dimensions for 13 dominant Iberian canopy tree species belonging to the Pinaceae (six Pinus species) and Fagaceae (six Quercus species and Fagus sylvatica) and related these architectural traits to wood density, shade tolerance and climatic factors. Fagaceae had, compared with Pinaceae, denser wood, saplings with wider crowns and adults with larger maximal crown size but smaller maximal height. In combination, these traits enhance light acquisition and persistence in shaded environments; thus, contributing to their shade tolerance. Pinaceae species, in contrast, had low-density wood, allocate more resources to the formation of the central trunk rather than to branches and attained taller maximal heights, allowing them to grow rapidly in height and compete for light following disturbances; thus, contributing to their high light requirements. Wood density had a strong relationship with tree architecture, with dense-wooded species having smaller maximum height and wider crowns, probably because of cheaper expansion costs for producing biomechanically stable branches. Species from arid environments had shorter stems and shallower crowns for a given stem diameter, probably to reduce hydraulic path length and assure water transport. Wood density is an important correlate of variation in tree architecture between species and the two dominant families, with potentially large implications for their resource foraging strategies and successional dynamics.

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Section: Discussionmentioning

confidence: 99%

Architecture of Iberian canopy tree species in relation to wood density, shade tolerance and climate

et al. 2012

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“…Commonly used shape metrics, such as maximal height and the width, do not represent the geometry of a structure in any detailed, or in an unambiguous way, and do not lend themselves well to interpretive visualizations of shape variation [1,12]. In addition, many biological hypotheses are concerned with allometry, or correlations between the overall size of an organism and the shape of its anatomy [59,61,41], and so e↵ectively separating an object's relative scale from its shape is an important consideration. Since linear measures are often correlated with size, for example, allometric questions are better addressed by shape metrics that are invariant to size.…”

Section: A Brief History Of Morphometricsmentioning

confidence: 99%

Shape Modeling and Analysis with Entropy-Based Particle Systems

Cates

Fletcher

Styner

et al. 2007

Lecture Notes in Computer Science

138

224

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Many important fields of basic research in medicine and biology routinely employ tools for the statistical analysis of collections of similar shapes. Biologists, for example, have long relied on homologous, anatomical landmarks as shape models to characterize the growth and development of species. Increasingly, however, researchers are exploring the use of more detailed models that are derived computationally from three-dimensional images and surface descriptions. While computationally-derived models of shape are promising new tools for biomedical research, they also present some significant engineering challenges, which existing modeling methods have only begun to address.In this dissertation, I propose a new computational framework for statistical shape modeling that significantly advances the state-of-the-art by overcoming many of the limitations of existing methods. The framework uses a particle-system representation of shape, with a fast correspondence-point optimization based on information content. The optimization balances the simplicity of the model (compactness) with the accuracy of the shape representations by using two commensurate entropy metrics and no free parameters. The idea is to maximize both the geometric accuracy and the statistical simplicity of the shape model, in accordance with the principle of parsimony in model selection. The nonparametric representation allows the method to be applied to a larger class of problems than existing methods, including nonspherical surfaces, open surfaces, and sets of multiple surfaces.The relative simplicity of the surface representation and the low number of free parameters results in a framework that is easy to use and can operate directly on image segmentations. In collaboration with scientists from several important areas of biomedicine, I have demonstrated that the proposed method is indeed an e↵ective tool for scientific research.The specific research contributions of this dissertation are as follows. First, I describe a mathematical framework and a robust numerical algorithm for computing optimized correspondence-point shape models using an entropy-based optimization and particle-system technology. Second, I develop a series of extensions of the framework to more general classes of shape analysis problems, including the analysis of multiple-object complexes, the generalization to correspondence based on generic functions of position, an extension to handle surfaces with open boundaries, and shape modeling with simple regression. Third, I describe the application of statistical hypothesis testing, regression analysis, and multiple-analysis of covariance to the proposed shape models. I also introduce new techniques for visualization and interpretation of these statistics. Finally, in cooperation with biomedical researchers, I present validation of the above research contributions by their successful application to real-world research problems.

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“…Data are expressed as mean ± standard error of the mean (SEM). Abdominal fat deposition rate was evaluated by the allometric coefficient β (beta) value in the allometric growth equation: log y (abdominal fat) = α + β [log x (body weight)], as proposed by Huxley & Teissier (1936). In order to assess allometric nature, the hypothesis was tested β=1 vs β>1 by Student's t test.…”

Section: Methodsmentioning

confidence: 99%

Effect of energy intake on performance and carcass composition of broiler chickens from two different genetic groups

Rosa

Filho

Dahlke

et al. 2007

Rev. Bras. Cienc. Avic.

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In order to evaluate the effect of energy intake and broiler genotype on performance, carcass yield, and fat deposition, 600 one-day-old male chicks from two different genetic groups (AgRoss 308 -commercial line and PCLC -Embrapa non-improved line) were fed diets with different metabolizable energy level (2950, 3200 and 3450 kcal/kg). A completely randomized experimental design in a 2X3 factorial arrangement with four replications of 25 birds per treatment was applied. In order to ensure different energy intake among treatments within each strain, feed intake was daily adjusted by pair-feeding schemes. AgRoss 308 broilers had better performance and carcass yield, and presented lower abdominal fat deposition rate. In both genetic groups, the highest dietary energy level increased weight gain, heart relative weight, and fat deposition. However, it reduced the difference between AgRoss 308 and PCLC for feed conversion ratio and carcass protein deposition. These findings allow concluding that genetic improvement had a significant effect on broiler energy metabolism, and that the highest performance differences between genetic groups are found when low-energy intake is imposed.

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Terminology of Relative Growth

Cited by 589 publications

References 5 publications

Architecture of Iberian canopy tree species in relation to wood density, shade tolerance and climate

Architecture of Iberian canopy tree species in relation to wood density, shade tolerance and climate

Shape Modeling and Analysis with Entropy-Based Particle Systems

Effect of energy intake on performance and carcass composition of broiler chickens from two different genetic groups

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