scholarly journals Comparative Study of Four Growth Models Applied to Weight and Height Growth Data in a Cohort of US Children from Birth to 9 Years

2014 ◽  
Vol 65 (2-3) ◽  
pp. 167-174 ◽  
Author(s):  
Nolwenn Regnault ◽  
Matthew W. Gillman ◽  
Ken Kleinman ◽  
Sheryl Rifas-Shiman ◽  
Jérémie Botton
Keyword(s):  
Comparative Study ◽  
Growth Models ◽  
Height Growth ◽  
Growth Data ◽  
Us Children

scholarly journals Dynamic Top Height Growth Models for Eight Native Tree Species in a Cool-Temperate Region in Northeast China

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 965
Author(s):  
Sandra-Maria Hipler ◽  
Heinrich Spiecker ◽  
Shuirong Wu
Keyword(s):  
Tree Species ◽  
Northeast China ◽  
Growth Models ◽  
Growth Curves ◽  
Height Growth ◽  
Shoot Length ◽  
Growth Data ◽  
Annual Shoot ◽  
Picea Asperata ◽  
Length Measurements

In this study, we developed dynamic top height growth models for the eight important Chinese tree species Larix gmelinii var. principis-rupprechtii, Pinus tabuliformis Carr., Pinus sylvestris var. mongolica Litv., Picea asperata Mast., Quercus mongolica Fisch. ex Ledeb, Betula platyphylla Suk., Betula dahurica Pall. and Populus davidiana Dode based on age-height relationships. For this purpose, commonly growth data from long-term observations of permanent experimental plots are used, which ideally cover all development stages from stand establishment to final harvest. As such data were not available in the research area of Hebei Province in Northeast China, we used stem analysis data as well as tree height and annual shoot length measurements. The dataset consisted of 72 stands, 233 dominant trees and 10,195 observations of stem discs and annual shoot length measurements. Five dynamic base-age invariant top height growth models were derived from four base models with the Generalized Algebraic Difference Approach and fitted to our age-height data using nested regression techniques. According to biological plausibility and model accuracy the Chapman–Richards model showed the best performance for Picea asperata. This selected model accounted for 99% of the total variance in age-height relationship with average absolute bias of 0.2322 m, root mean square error of 0.3337 m and of 0.9979, respectively. The distribution of the residuals was scattered around 0 and without visible trends, indicating that the fitness of the models was good. All developed models are able to generate top height growth curves representing the analyzed height growth data and can be utilized for predicting height growth on the base of current height and age of dominant trees. Additionally, they are the base for calculating the development of other relevant stand attributes such as basal area and volume growth. The determination of potential site productivity by the use of top height growth curves is a practical and convenient method for a simplified presentation of complex growth processes in stands and helps to create growth models, which facilitate implementing sustainable forest management practices in Mulan Forest.

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.

Dynamic Predictive Model for Growth of Bacillus cereus from Spores in Cooked Beans

2017 ◽  
Vol 81 (2) ◽  
pp. 308-315 ◽  
Author(s):  
Vijay K. Juneja ◽  
Abhinav Mishra ◽  
Abani K. Pradhan
Keyword(s):  
Bacillus Cereus ◽  
Growth Rates ◽  
Linear Models ◽  
Growth Models ◽  
Maximum Growth ◽  
Effect Of Temperature ◽  
Coefficient Of Determination ◽  
Growth Data ◽  
Three Phase ◽  
Primary Model

ABSTRACT Kinetic growth data for Bacillus cereus grown from spores were collected in cooked beans under several isothermal conditions (10 to 49°C). Samples were inoculated with approximately 2 log CFU/g heat-shocked (80°C for 10 min) spores and stored at isothermal temperatures. B. cereus populations were determined at appropriate intervals by plating on mannitol–egg yolk–polymyxin agar and incubating at 30°C for 24 h. Data were fitted into Baranyi, Huang, modified Gompertz, and three-phase linear primary growth models. All four models were fitted to the experimental growth data collected at 13 to 46°C. Performances of these models were evaluated based on accuracy and bias factors, the coefficient of determination (R2), and the root mean square error. Based on these criteria, the Baranyi model best described the growth data, followed by the Huang, modified Gompertz, and three-phase linear models. The maximum growth rates of each primary model were fitted as a function of temperature using the modified Ratkowsky model. The high R2 values (0.95 to 0.98) indicate that the modified Ratkowsky model can be used to describe the effect of temperature on the growth rates for all four primary models. The acceptable prediction zone (APZ) approach also was used for validation of the model with observed data collected during single and two-step dynamic cooling temperature protocols. When the predictions using the Baranyi model were compared with the observed data using the APZ analysis, all 24 observations for the exponential single rate cooling were within the APZ, which was set between −0.5 and 1 log CFU/g; 26 of 28 predictions for the two-step cooling profiles also were within the APZ limits. The developed dynamic model can be used to predict potential B. cereus growth from spores in beans under various temperature conditions or during extended chilling of cooked beans.

scholarly journals Multi-level modelling of longitudinal child growth data from the Birth-to-Twenty Cohort: a comparison of growth models

2013 ◽  
Vol 41 (2) ◽  
pp. 168-179 ◽  
Author(s):  
Esnat D. Chirwa ◽  
Paula L. Griffiths ◽  
Ken Maleta ◽  
Shane A. Norris ◽  
Noel Cameron
Keyword(s):  
Growth Models ◽  
Child Growth ◽  
Growth Data ◽  
Multi Level

scholarly journals Prediction of Mold Spoilage for Soy/Polyethylene Composite Fibers

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Chinmay Naphade ◽  
Inyee Han ◽  
Sam Lukubira ◽  
Amod Ogale ◽  
James Rieck ◽  
...  
Keyword(s):  
Growth Models ◽  
Storage Period ◽  
Weibull Model ◽  
Mold Growth ◽  
Growth Data ◽  
Final Model ◽  
Polyethylene Composite ◽  
Interaction Term ◽  
Environmental Temperatures ◽  
Best Fit

Mold spoilage was determined over 109 days on soy/PE fibers held under controlled temperatures (T) ranging from 10°C to 40°C and water activities(aw)from 0.11 to 0.98. Water activities were created in sealed containers using saturated salt solutions and placed in temperature-controlled incubators. Soy/PE fibers that were held at 0.823awor higher exhibited mold growth at all temperatures. As postulated, increased water activity (greater than 0.89) and temperature (higher than 25°C) accelerated mold growth on soy/PE fibers. A slower mold growth was observed on soy/PE fibers that were held at 0.87awand 10°C. A Weibull model was employed to fit the observed logarithmic values ofT, aw, and an interaction termlog⁡T×log⁡awand was chosen as the final model as it gave the best fit to the raw mold growth data. These growth models predict the expected mold-free storage period of soy/PE fibers when exposed to various environmental temperatures and humidities.

Suitability of two methods of evaluating site quality for sugar maple in central Ontario

2006 ◽  
Vol 82 (5) ◽  
pp. 733-744 ◽  
Author(s):  
Nicholas J Buda ◽  
Jian R Wang
Keyword(s):  
Sugar Maple ◽  
Quality Evaluation ◽  
Growth Models ◽  
Site Index ◽  
Height Growth ◽  
Site Quality ◽  
Dominant Height ◽  
Index Site ◽  
Species Mixture ◽  
Stand Conditions

Stem analyses data collected in central Ontario stands were used to develop site index (height and age) and site form (height and diameter) models and curves for sugar maple. The suitability of both methods for evaluating sugar maple site productivity was examined. Two different equation forms were evaluated for both site index and site form models. A common modification of Richard's (1959) equation was most suitable for predicting dominant height at index age (site index) and reference diameter (site form). Potential effects of species mixture on sugar maple site index were examined. We found no significant effects on sugar maple height growth and site index in mixed stand conditions common in the region when compared to pure stands. The potential of site form as an alternative to site index was investigated through correlation analyses with site index and other site variables known to influence sugar maple height growth. Site form was not related to site index, nor any site variables related to sugar maple height growth. It is therefore inadequate for evaluating sugar maple site quality. We recommend height growth models and site index curves developed in this study be used to replace those from other regions currently used in central Ontario. Key words: site index, site form, sugar maple, site quality evaluation, mixedwood, uneven-aged

Comparison and estimation of the growth curve models of Hanwoo steer (Bos taurus coreanae)

2018 ◽  
Author(s):  
Hu-Rak Park ◽  
Seung-Hoon Eum ◽  
Seung-Hee Roh ◽  
Jakyeom Seo ◽  
Seong-Keun Cho ◽  
...  
Keyword(s):  
Body Weight ◽  
Logistic Model ◽  
Bos Taurus ◽  
Growth Models ◽  
Logistic Models ◽  
Regression Equations ◽  
Von Bertalanffy ◽  
Growth Data ◽  
Growth Ratio ◽  
Mean Square Errors

The present study was conducted to estimate and compare the three types of growth models in Hanwoo steer (Bos aurus coreanae). The Gompertz, Von Bertalanffy, and Logistic nonlinear models were used. A total of 2,239 Hanwoo steers (Bos taurus coreanae) from 6 months to 24 months old (2003 to 2014) and 8,916 growth data from the Hanwoo improvement Center were used to estimate the growth model which included three parameters. These parameters were A, mature body weight; b, growth ratio; and k, intrinsic growth rate. Regression equations using the Gompertz, Von Bertalanffy, and Logistic models were calculated as respectively. The mean square errors (MSEs) for each model were 1945.9, 1958.7, and 1935.0, respectively. The equation using the Logistic model showed the lowest value among three models. The estimated birth weights from the Gompertz, Von Bertalanffy, and Logistic models were 50.35 kg, 36.94 kg, and 74.13 kg, respectively. Furthermore, the estimated mature weights from the Gompertz, Von Bertalanffy, and Logistic models were 919.0 kg, 1043.3 kg, and 770.0 kg, respectively. In addition, the estimated age and body weight at inflection from the Gompertz, Von Bertalanffy, and Logistic models were 349.0 days and 338.1 kg, 317.9 days and 308.2 kg, and 397.8 days and 385.0 kg, respectively. Based on the results, we concluded that the regression equation using the Logistic model was the most appropriate among the growth models for measuring data. However, further studies would be needed in order to obtain more accurate parameters using a much wider period of data from birth to shipping age.

Probabilities of small-gap capture by sugar maple saplings based on height and crown growth data from felled trees

2005 ◽  
Vol 35 (3) ◽  
pp. 643-655 ◽  
Author(s):  
William G Cole ◽  
Craig G Lorimer
Keyword(s):  
Sugar Maple ◽  
Initial Conditions ◽  
Tree Height ◽  
Height Growth ◽  
Stochastic Simulations ◽  
Gap Formation ◽  
Growth Data ◽  
Stochastic Variation ◽  
Single Tree ◽  
Advance Regeneration

We simulated the probability that Acer saccharum Marsh. saplings in single-tree gaps would reach the overstory before lateral gap closure. The model was calibrated with height and crown growth data from destructively sampled trees that ranged from 1 to 27 m tall. Each of the major initial conditions and growth processes was evaluated separately to determine its effect on gap-capture probabilities. Factors such as sapling height at the time of gap formation, continued height growth of border trees, and stochastic growth variation had pronounced effects on the outcome. Stochastic variation generally increased chances of sapling success by delaying closure times in some of the gaps and allowing some saplings to grow at above-average rates. In stochastic simulations with continued (asymptotic) border-tree height growth, probabilities of successful gap capture ranged from <20% of saplings 1–2 m tall to 35%–86% for saplings 7–8 m tall. The results suggest that some saplings may be able to capture gaps after one gap event, but probabilities are low for small saplings and for all saplings in small and medium gaps. Based on the mechanisms simulated here, most of the larger single-tree gaps (78 m2) are captured by advance regeneration more than 4 m tall.

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