نتایج جستجو برای: allometric ratio

تعداد نتایج: 505094  

Journal: :Ecology 2006
Annikki Mäkelä Harry T Valentine

Allometric theories suggest that the size and shape of organisms follow universal rules, with a tendency toward quarter-power scaling. In woody plants, however, structure is influenced by branch death and shedding, which leads to decreasing crown ratios, accumulation of heartwood, and stem and branch tapering. This paper examines the impacts on allometric scaling of these aspects, which so far ...

Journal: :Journal of applied physiology 1995
A M Nevill R L Holder

The practice of scaling or normalizing physiological variables (Y) by dividing the variable by an appropriate body size variable (X) to produce what is known as a "per ratio standard" (Y/ X), has come under strong criticism from various authors. These authors propose an alternative regression standard based on the linear regression of (Y) on (X) as the predictor variable. However, if linear reg...

Journal: :Journal of evolutionary biology 2016
J Neustupa

The surface area-to-volume ratio of cells is one of the key factors affecting fundamental biological processes and, thus, fitness of unicellular organisms. One of the general models for allometric increase in surface-to-volume scaling involves fractal-like elaboration of cellular surfaces. However, specific data illustrating this pattern in natural populations of the unicellular organisms have ...

2016
Yunfeng Peng Yuanhe Yang

Allometric and optimal hypotheses have been widely used to explain biomass partitioning in response to resource changes for individual plants; however, little evidence has been reported from measurements at the community level across a broad geographic scale. This study assessed the nitrogen (N) effect on community-level root to shoot (R/S) ratios and biomass partitioning functions by synthesiz...

اخوان, رضا, متاجی, اسداله, واحدی, علی‌ اصغر ,

Modelling allometric equations for saplings of hybrid poplar clone produce a highly accurate estimate of pure productivity and C sequestration, leading to better sales and determination of the capacity of cellulose resources and bio-energy pools. Twenty five cuttings with 25 cm length were planted within a 1×1 m2 area in the Talookola nursery, Sari, in 2011. Ten saplings were selected from the ...

Journal: :The Journal of orthopaedic and sports physical therapy 2014
Terese L Chmielewski Christine Martin Trevor A Lentz Susan M Tillman Michael W Moser Kevin W Farmer Slobodan Jaric

STUDY DESIGN Cross-sectional study. OBJECTIVES To examine the effect of different normalization methods on unilateral seated shot put test results. BACKGROUND The unilateral seated shot put test could assist clinical decision making in upper extremity rehabilitation, but test results must be normalized to compare across patients. The effect of normalization methods based on body size and up...

2015
Chan Zhou Zhengwen Wang Junyue Guo Zhuo Zhang Yunfei Yang Mai-He Li

Reproductive allocation is critically important for population maintenance and usually varies with not only environmental factors but also biotic ones. As a typical rhizome clonal plant in China's northern grasslands, Leymus chinensis usually dominates the steppe communities and grows in clonal patches. In order to clarify the sexual reproductive allocation of L. chinensis in the process of the...

2017
Laura Duncanson Wenli Huang Kristofer Johnson Anu Swatantran Ronald E McRoberts Ralph Dubayah

BACKGROUND Carbon accounting in forests remains a large area of uncertainty in the global carbon cycle. Forest aboveground biomass is therefore an attribute of great interest for the forest management community, but the accuracy of aboveground biomass maps depends on the accuracy of the underlying field estimates used to calibrate models. These field estimates depend on the application of allom...

Journal: :The Biological bulletin 2000
S V Vollmer P J Edmunds

Although most physiological traits scale allometrically in unitary organisms, it has been hypothesized that modularity allows for isometric scaling in colonial modular taxa. Isometry would allow increases in size without functional constraints, and is thought to be of central importance to the success of a modular design. Yet, despite its potential importance, scaling in these organisms has rec...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید