DEPENDENCE OF THE INDIVIDUAL GROWTH PROCESS UPON ALLOMETRIC SCALING EXPONENTS AND OTHER PARAMETERS

2008 ◽  
Vol 16 (01) ◽  
pp. 151-163 ◽  
Author(s):  
D. BISWAS ◽  
S. K. DAS ◽  
S. ROY
Keyword(s):  
Growth Rate ◽  
Energy Production ◽  
Growth Process ◽  
Metabolic Cost ◽  
Individual Growth ◽  
Scaling Exponent ◽  
Intake Rate ◽  
Mass Variation ◽  
Surplus Energy ◽  
The Individual

In the present study, the individual growth process of an organism has been shown with the help of a mathematical model. The surplus energy production rate, i.e. intake rate minus metabolic cost, plays a crucial role in controlling the growth rate. Considering the existence of an optimum mass, which maximizes the surplus energy, it has been found that the scaling exponent for the metabolic cost has to be greater than the exponent for the intake rate. On the basis of the consideration that the system always generates some surplus energy, a relationship among the empirical constants has been established. The growth is found to continue with an ever decreasing rate. When the system attains its optimum mass, the growth rate is found to be the maximum. The mass variation with time has been graphically shown using the expression obtained by solving a differential equation involving surplus energy. Using figures, the dependence of mass variation upon various scaling parameters, has been thoroughly discussed. As mass increases, the surplus energy production rate per unit mass is found to decrease and this may be the probable reason for the smaller number of organisms with larger mass. As the scaling exponent regarding intake increases, the maximum attainable mass increases along with an increase in the time required for its attainment.

Visualization of Individual Growth-Related Craniofacial Changes Based on Cephalometric Landmark Data: A Pilot Study

2002 ◽  
Vol 39 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Christopher J. Lux ◽  
Jens Starke ◽  
Jan Rübel ◽  
Angelika Stellzig ◽  
Gerda Komposch
Keyword(s):  
Dynamic Behavior ◽  
Growth Process ◽  
Shape Change ◽  
Individual Growth ◽  
Craniofacial Skeleton ◽  
Size And Shape ◽  
Lateral Cephalograms ◽  
Landmark Data ◽  
The Individual ◽  
Shape Changes

Objective: An approach based on Euclidean distances between cephalometric landmarks is presented (1) to visualize and localize the individual shape changes of the complex craniofacial skeleton during growth and (2) to depict the individual dynamic behavior of developmental size and shape changes. Patients and Method: Growth-related craniofacial changes were investigated exemplarily for two male orthodontically untreated subjects from the Belfast Growth Study on the basis of lateral cephalograms at 7, 9, 11, 13, and 15 years. The interlandmark distances among seven skeletal cephalometric landmarks served as a database for the study. A modified Karhunen-Loèvedecomposition based on orthogonal modes and time-dependent scalar amplitudes was used to describe the growth process. The individual shape changes of the various craniofacial regions were visualized by allocation of colors to the respective distances, and overdrawn representations were reconstructed by means of multidimensional scaling. Results and Conclusions: This visualization technique allows anatomical regions to be characterized with respect to reduced or strengthened growth, compared with pure size changes. The clinically relevant mechanisms of craniofacial changes are visualized (e.g., shifts in the anteroposterior or vertical dimensions of the jaws in relation to cranial base and structural imbalances during development). In addition, overdrawing the effects of shape change on the skeletal structures gives a more readily comprehensible impression of the growth process. Taking account of the methodical limitations of this approach (e.g., the restrictions concerning the number of landmarks), the clinician may take advantage of this technique in orthodontic or surgical diagnostics to gain additional insight into the individual complex size and shape changes during development along with their dynamic behavior.

scholarly journals Development and population growth of Hydra viridissima Pallas, 1766 (Cnidaria, Hydrozoa) in the laboratory

2008 ◽  
Vol 68 (2) ◽  
pp. 379-383 ◽  
Author(s):  
FC. Massaro ◽  
O. Rocha
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Generation Time ◽  
Doubling Time ◽  
Test Organism ◽  
Laboratory Culture ◽  
Individual Growth ◽  
Population Doubling ◽  
Population Doubling Time ◽  
The Individual

Hydras, the most representative freshwater Cnidaria, are of common occurrence in bodies of water in every continent except Antarctica. This study was planned with the aim of maintaining a population of Hydra viridissima in laboratory culture to enable the determination of the individual and population growth-rates of this species, as well as its population doubling time and generation time, with a view to employing these common animals as test-organisms in ecotoxicological assays. The organisms were maintained in reconstituted water at 20 ± 2 °C, illuminated at 800 lux with a photoperiod of 12 hours light: 12 hours dark, and were fed on neonates of the cladoceran Ceriodaphnia silvestrii (3 or 4 neonates per hydra, 3 times a week). The individual growth-rate (k) of the species was 0.43, the maximum length of the column 2.53 mm and the generation time 6.6 ± 1.5 days on average. The hydra population showed an intrinsic growth-rate (r) of 0.0468, according to the fitted curve, and a doubling time of 14.8 ± 2.63 days. Hydra viridissima is easy to grow in the laboratory and performs well in the conditions used in this study. It is thus a promising candidate test-organism for ecotoxicological studies.

The theory of differential growth analysis

1950 ◽  
Vol 137 (889) ◽  
pp. 470-474 ◽  
Keyword(s):  
Growth Rate ◽  
Growth Process ◽  
Growth Analysis ◽  
Specific Growth ◽  
Differential Growth ◽  
Mathematical Symbolism ◽  
Absolute Growth Rate ◽  
Absolute Growth ◽  
Living Organisms ◽  
The Individual

Growth will be defined as that attribute of living organisms which is manifested by a change of size of the individual, and we shall first consider growth formulae and curves. If y represents the size of any individual at time t , and if the growth process is regarded as continuous, we may define the absolute growth rate as dy/dt and the specific growth rate (which represents the change in y for change in time per unit amount of y ) as 1/ y dy/dt . Any statement which relates the size or growth rate of an organism to other variables will be called a growth formula; such statements are usually expressed in mathematical symbolism. Many growth formulae have been published and they have been derived by one of three methods.

Assessing the production and the impact of cultivated oysters in the Thau lagoon (Mediterranee, France) with a population dynamics model

2001 ◽  
Vol 58 (5) ◽  
pp. 1012-1020 ◽  
Author(s):  
A Gangnery ◽  
C Bacher ◽  
D Buestel
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Standing Stock ◽  
Individual Growth ◽  
Economic Activities ◽  
Daily Growth ◽  
Mediterranean Mussel ◽  
Thau Lagoon ◽  
The Individual ◽  
The Impact

The Thau lagoon (France) has been studied for many years because of its ecological interest related to economic activities: shellfish cultivation, tourism, and industry. The standing stock of cultivated filter feeders is around 20 000 t and consists of two main species, the Japanese oyster Crassostrea gigas and the Mediterranean mussel Mytilus galloprovincialis. To predict changes in the standing stock and the annual production, a mathematical model of the population dynamics was defined. It was based on the continuous equation of the density as a function of the mortality rate, the individual growth rate, and the interindividual variability. The daily growth rate was derived from field surveys and depended on the phytoplankton concentration and individual weight. The model also took into account the rearing strategy of the producers defined by the timetable of seeding and harvesting, obtained by an inquiry among the producers and used to simulate real cases of standing stock changes. The model was also used to assess the potential impact on the environment through the computation of the food consumption, which was compared with the residence time and the primary production.

scholarly journals “IT’S OVER 9000.” APEIRON NARRATIVE CONFIGURATIONS IN CONTEMPORARY MEDIASCAPE

2018 ◽  
Vol 1 (1) ◽  
pp. 79-94
Author(s):  
Vincenzo Idone Cassone
Keyword(s):  
New Media ◽  
Growth Process ◽  
Digital Games ◽  
Role Playing ◽  
Individual Growth ◽  
The Internet ◽  
Internet Culture ◽  
Role Playing Games ◽  
The Individual

Recently, a peculiar narrative configuration has developed and is spreading through the internet culture and new media. Characterised by a specific representation of the individual growth process, Apeiron narratives find their origin in pen & paper role-playing games, but it is only after the development of digital games and the diffusion of the Japanese cultural codex through the contemporary mediascape that they have become a coherent, autonomous and viral phenomenon. In the following pages, this narrative configuration will be described through a series of paradigmatic examples; its roots will be traced back to the peculiar traits of role-playing games, and the importance of recent digital adaptation will be highlighted. Finally, I will describe its diffusion beyond the domain of fictional text, hinting at possible environments for its diffusion.

scholarly journals The effect of growth rate on otolith-based discrimination of cod (Gadus morhua) ecotypes

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0247630
Author(s):  
Einar Pétur Jónsson ◽  
Steven E. Campana ◽  
Jón Sólmundsson ◽  
Klara B. Jakobsdóttir ◽  
Hlynur Bárðarson
Keyword(s):  
Growth Rate ◽  
Gadus Morhua ◽  
Sampling Period ◽  
Individual Growth ◽  
Discrete Wavelet ◽  
Shape Variation ◽  
Otolith Shape ◽  
Individual Growth Rate ◽  
The Individual ◽  
The Relationship

Otolith shape has previously been used to identify ecotypes within the Icelandic cod (Gadus morhua) stock, using DST profiles to validate the results. Fish otolith shape variation has repeatedly been found to be largely determined by growth rate. To examine the effect of growth rate on the relationship between otolith shape and cod ecotypes (using the Pan I genotype as a proxy for ecotype), 826 archived sagittal otoliths collected over a 58 year sampling period were retrieved, the individual growth rate calculated, and otolith shape described using both Normalized Elliptic Fourier transform and Discrete Wavelet transform. Discriminant functions of otolith shape successfully classified ecotype, whether using Fourier or Wavelet descriptors, but only when excluding a heterozygous genotype from the analysis. The otolith shape variability of this genotype lowered the classification success, while otolith shape, in turn, was significantly affected by growth rate and cohort. Growth rate differences previously reported for the ecotypes were present, but were less marked than expected and indeed, growth rate variance attributable to ecotype identity was dwarfed by cohort- and location-related variance in growth. Such a strong effect of growth rate suggests that cod ecotype discrimination based on otolith shape is sensitive to both temporal and spatial variations in growth, which can mask the effect of ecotype-related growth rate differences on otolith shape.

scholarly journals Otolith-based discrimination of cod ecotypes and the effect of growth rate

2021 ◽  
Author(s):  
Einar Pétur Jónsson ◽  
Steven E. Campana ◽  
Jón Sólmundsson ◽  
Klara B. Jakobsdóttir ◽  
Hlynur Bárðarson
Keyword(s):  
Growth Rate ◽  
Gadus Morhua ◽  
Sampling Period ◽  
Individual Growth ◽  
Discrete Wavelet ◽  
Shape Variation ◽  
Otolith Shape ◽  
Individual Growth Rate ◽  
The Individual ◽  
The Relationship

AbstractOtolith shape has previously been used to identify ecotypes within the Icelandic cod (Gadus morhua) stock, using DST profiles to validate the results. Fish otolith shape variation has repeatedly been found to be largely determined by growth rate. To examine the effect of growth rate on the relationship between otolith shape and cod ecotypes (using the Pan I genotype as a proxy for ecotype), 826 archived sagittal otoliths collected over a 52 year sampling period were retrieved, the individual growth rate calculated, and otolith shape described using both Normalized Elliptic Fourier transform and Discrete Wavelet transform. Discriminant functions of otolith shape yielded high ecotype classification success, whether using Fourier or Wavelet descriptors, but only when excluding a heterozygous genotype from the analysis. The otolith shape variability of this genotype lowered the classification success, while otolith shape, in turn, was significantly affected by growth rate and cohort. Growth rate differences previously reported for the ecotypes were present, but were less marked than expected and indeed, growth rate variance attributable to ecotype identity was dwarfed by cohort- and location-related variance in growth. Such a strong effect of growth rate suggests that cod ecotype discrimination based on otolith shape is sensitive to both temporal and spatial variations in growth, which can mask the effect of ecotype-related growth rate differences on otolith shape.

Graphical Estimation of Rates of Mortality and Growth

1970 ◽  
Vol 27 (1) ◽  
pp. 204-208 ◽  
Author(s):  
Roger H. Green
Keyword(s):  
Growth Rate ◽  
Mortality Rate ◽  
Individual Growth ◽  
Individual Growth Rate ◽  
Population Mortality ◽  
The Individual ◽  
Average Size ◽  
Individual Size

A method is presented by which the individual growth rate and the population mortality rate can be estimated graphically in certain populations, given only knowledge of maximum individual size and of average size at two times of the year. The four graphs that are given may be used in several different ways, depending on the information available.

scholarly journals Studies of Comparative Fleece Growth in Sheep I. The Quantitative Nature of Inherent Differences in Wool-Growth Rate

1949 ◽  
Vol 2 (1) ◽  
pp. 42 ◽  
Author(s):  
KA Ferguson ◽  
HB Carter ◽  
Margaret H Hardy
Keyword(s):  
Growth Rate ◽  
Nutrient Intake ◽  
Intake Rate ◽  
Asymptotic Value ◽  
Wool Growth ◽  
Diminishing Returns ◽  
Rate Characteristic ◽  
The Individual ◽  
Quantitative Nature

Since wool-growth rate is strongly influenced by the plane of nutrition, any measure of inherent wool-producing capacity in the sheep must take this into account, and the relation of these three factors to each other must be known. On general grounds, the relation of wool-growth rate to nutrient intake seems likely to follow the familiar law of diminishing returns which introduces the concept that for each sheep there may be an asymptotic value of wool-growth rate characteristic of the individual. From this and other considerations, it was postulated that these relationships could be described by an equation of the form where y = wool-growth rate, x = nutrient intake rate at or above maintenance levels, Xo = the nutrient intake rate for which y = 0, A = the asymptotic value of y, and k' = a constant dependent on the nutritive qualities of the diet employed:

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