scholarly journals Individual growth model for the appendicularian Oikopleura dioica

2003 ◽  
Vol 248 ◽  
pp. 141-163 ◽  
Author(s):  
F Touratier ◽  
F Carlotti ◽  
G Gorsky
Keyword(s):  
Growth Model ◽  
Individual Growth ◽  
Oikopleura Dioica

scholarly journals Comparison of growth models to describe growth from birth to 6 years in a Beninese cohort of children with repeated measurements

BMJ Open ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. e035785
Author(s):  
Shukrullah Ahmadi ◽  
Florence Bodeau-Livinec ◽  
Roméo Zoumenou ◽  
André Garcia ◽  
David Courtin ◽  
...  
Keyword(s):  
Growth Model ◽  
Goodness Of Fit ◽  
Growth Models ◽  
Information Criterion ◽  
Height Growth ◽  
Sub Saharan Africa ◽  
Individual Growth ◽  
Secondary Outcome ◽  
Growth Trajectories ◽  
Best Fitting

ObjectiveTo select a growth model that best describes individual growth trajectories of children and to present some growth characteristics of this population.SettingsParticipants were selected from a prospective cohort conducted in three health centres (Allada, Sekou and Attogon) in a semirural region of Benin, sub-Saharan Africa.ParticipantsChildren aged 0 to 6 years were recruited in a cohort study with at least two valid height and weight measurements included (n=961).Primary and secondary outcome measuresThis study compared the goodness-of-fit of three structural growth models (Jenss-Bayley, Reed and a newly adapted version of the Gompertz growth model) on longitudinal weight and height growth data of boys and girls. The goodness-of-fit of the models was assessed using residual distribution over age and compared with the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The best-fitting model allowed estimating mean weight and height growth trajectories, individual growth and growth velocities. Underweight, stunting and wasting were also estimated at age 6 years.ResultsThe three models were able to fit well both weight and height data. The Jenss-Bayley model presented the best fit for weight and height, both in boys and girls. Mean height growth trajectories were identical in shape and direction for boys and girls while the mean weight growth curve of girls fell slightly below the curve of boys after neonatal life. Finally, 35%, 27.7% and 8% of boys; and 34%, 38.4% and 4% of girls were estimated to be underweight, wasted and stunted at age 6 years, respectively.ConclusionThe growth parameters of the best-fitting Jenss-Bayley model can be used to describe growth trajectories and study their determinants.

Individual Growth and Reproduction

2019 ◽  
pp. 38-56
Author(s):  
Ken H. Andersen
Keyword(s):  
Life History ◽  
Growth Model ◽  
Life Histories ◽  
Maximum Size ◽  
Individual Growth ◽  
Energy Budgets ◽  
Asymptotic Size ◽  
The Individual ◽  
Growth And Reproduction

This chapter develops descriptions of how individuals grow and reproduce. More specifically, the chapter seeks to determine the growth and reproduction rates from the consumption rate, by developing an energy budget of the individual as a function of size. To that end, the chapter addresses the question of how an individual makes use of the energy acquired from consumption. It sets up the energy budgets of individuals by formulating the growth model using so-called life-history invariants, which are parameters that do not vary systematically between species. While the formulation of the growth model in terms of life-history invariants is largely successful, there is in particular one parameter that is not invariant between life histories: the asymptotic size (maximum size) of individuals in the population. This parameter plays the role of a master trait that characterizes most of the variation between life histories.

Length-at-Age Analysis: Can You Get What You See?

1992 ◽  
Vol 49 (4) ◽  
pp. 632-643 ◽  
Author(s):  
T. J. Mulligan ◽  
B. M. Leaman
Keyword(s):  
Growth Model ◽  
Time Trend ◽  
Single Point ◽  
Mortality Rates ◽  
Individual Growth ◽  
Parameter Estimates ◽  
Von Bertalanffy ◽  
Model Ambiguity ◽  
Von Bertalanffy Growth Model ◽  
Single Set

Observations at a single point in time of length-at-age (LAA) for a long-lived rockfish (Sebastes alutus) show that old fish are shorter than intermediate-aged fish. Fitting of a von Bertalanffy growth model to these data produces a systematic trend in the residual of observed versus calculated LAA. We examined how such LAA data can lead to erroneous conclusions about individual growth, and whether asymptotic growth can give rise to such data. We considered two hypotheses: (i) that a time trend in growth rate resulted in larger fish in more recent years and (ii) that there are multiple growth types, where growth and mortality rates are directly related. Using a general growth model that incorporated both (i) and (ii), we show that both hypotheses can generate data identical to those for the rockfish. A single set of LAA data is inadequate for describing individual growth; however, if sufficient data are available, model ambiguity can be resolved and reasonable parameter estimates obtained. Analysis of the rockfish data indicates that (ii) is more likely to explain the observations than (i). We show how fisheries on such species may preclude our understanding these biological relationships.

Prototype Individual Growth Model For Inpatient Recovery of Motor Function in Persons Recovering From Stroke

2017 ◽  
Vol 98 (10) ◽  
pp. e97
Author(s):  
Allan Kozlowski ◽  
Frank Hyland ◽  
Sandra Marrone ◽  
Susan Golden ◽  
Nicole Yenser ◽  
...  
Keyword(s):  
Motor Function ◽  
Growth Model ◽  
Individual Growth ◽  
Recovery Of Motor Function

Growth Model of Daphnia

1982 ◽  
Vol 39 (4) ◽  
pp. 598-606 ◽  
Author(s):  
J. E. Paloheimo ◽  
S. J. Crabtree ◽  
W. D. Taylor
Keyword(s):  
Growth Model ◽  
Aquatic Ecosystems ◽  
Cell Concentration ◽  
Daphnia Pulex ◽  
Assimilation Efficiency ◽  
Somatic Growth ◽  
Individual Growth ◽  
Nutrient Level ◽  
Model Predictions ◽  
Growth And Reproduction

Data from experiments on feeding, assimilation, and reproduction of Daphnia pulex grown in different cell concentrations of Chlamydomonas reinhardtii formed the basis for an individual growth model for D. pulex. The model predictions of both the somatic growth and reproduction agree with subsequent experimental results. Contrary to many higher organisms, the assimilation efficiency increases with increasing body size. This may be, at least in part, the reason why larger body-sized zooplankton tend to dominate in aquatic ecosystems when not controlled by predators. The uptake rate per body weight as a function of cell concentration can be described by Michaelis–Menten type equations, but not the assimilation rate. Contrast between the feeding and assimilation rates suggest that as the nutrient level increases, a higher proportion of uptake is channeled by Daphnia into the detritus/bacterial compartment.Key words: Daphnia pulex, feeding, energetics, assimilation, growth model, nutrient level

Ontogeny of energetic relationships and potential effects of tissue turnover: a comparative modeling study on lake trout

1998 ◽  
Vol 55 (11) ◽  
pp. 2518-2532 ◽  
Author(s):  
Jixiang He ◽  
Donald J Stewart
Keyword(s):  
Growth Model ◽  
Lake Trout ◽  
Somatic Growth ◽  
Complex Model ◽  
Individual Growth ◽  
Metabolic System ◽  
New Model ◽  
Gonadal Growth ◽  
Tissue Turnover ◽  
Energy Assimilation

Tissue turnover is endogenous energy flow and may play a regulatory role in the metabolic system of an organism. We developed a general growth model addressing potential effect of tissue turnover on energy acquisition and partitioning. We applied the model to estimate energy assimilation of lake trout (Salvelinus namaycush) in Lake Michigan and compared the model with a commonly used complex model. Both models are expansions of the Pütter - von Bertalanffy growth model. The new model suggested a consistent decreasing trend in energy net conversion efficiency (NCE) for somatic growth versus body energy. The complex model suggested that NCE is relatively stable in early ages and decreases slowly in comparison with the pattern suggested by the new model. The new model estimated higher specific assimilation rate and NCE for gonadal growth than for somatic growth of mature fish. The complex model did not distinguish gonadal growth from somatic growth. For a lake trout growing from the start of age-1 to the end of age-10, our new model suggested a total energy assimilation 25% higher than the complex model. The above comparisons support the inference that tissue turnover is an important bioenergetic component. Inclusion of tissue turnover in bioenergetic modeling analyses may be critical for studying the linkages among individual growth, reproduction, and population dynamics.

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