scholarly journals Growth-related life-history traits of an invasive gammarid species: evaluation with a Laird–Gompertz model

2003 ◽  
Vol 81 (12) ◽  
pp. 2006-2014 ◽  
Author(s):  
Christophe Piscart ◽  
Simon Devin ◽  
Jean-Nicolas Beisel ◽  
Jean-Claude Moreteau
Keyword(s):  
Growth Rate ◽  
Growth Curve ◽  
Environmental Conditions ◽  
Sexual Maturity ◽  
Growth Models ◽  
Gompertz Model ◽  
Biological Traits ◽  
Freshwater Species ◽  
Dikerogammarus Villosus ◽  
Forcing Function

Although the invasive gammarid Dikerogammarus villosus (Crustacea, Amphipoda) is a recent successful invader of Western Europe's lakes and rivers and a threat to North American aquatic ecosystems, its biology is scarcely known. Different growth models for each sex were established for the first time for a natural population of a freshwater gammarid. The Laird–Gompertz growth curve was used because it best fit our data, and it was associated with an environmental forcing function to adjust the growth rate according to seasonal variations in environmental conditions. The growth curve was applied to a length decomposition obtained using the Bhattacharya method, realised on data obtained from a 1-year population dynamics study. The models allowed an assessment of biological traits such as life-span, the age of sexual maturity, the potential number of generations per year, and the growth rate as a function of environmental conditions. Differences in growth rate between males and females were consistent with biological processes such as allocation of energy for reproduction. Dikerogammarus villosus had higher rates of growth and earlier sexual maturity than all other taxa studied, which may explain its invasive tendencies and its ability to colonize numerous new ecosystems, thus becoming a cosmopolitan freshwater species.

Application of non-linear mixed models for modelling the quail growth curve for meat and laying

2018 ◽  
Vol 156 (10) ◽  
pp. 1216-1221 ◽  
Author(s):  
H. B. Santos ◽  
D. A. Vieira ◽  
L. P. Souza ◽  
A. L. Santos ◽  
F. R. Santos ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Curve ◽  
Mixed Models ◽  
Gompertz Model ◽  
Average Growth ◽  
Relative Growth ◽  
Female Quail ◽  
Absolute Growth ◽  
Growth Profiles ◽  
Best Fit

AbstractThe objective of the current paper was to apply mixed models to adjust the growth curve of quail lines for meat and laying hens and present the rates of instantaneous, relative and absolute growth. A database was used with birth weight records up to the 148th day of female quail of the lines for meat and posture. The models evaluated were Brody, Von Bertalanffy, Logistic and Gompertz and the types of residues were constant, combined, proportional and exponential. The Gompertz model with the combined residue presented the best fit. Both strains present a high correlation between the parameters asymptotic weight (A) and average growth rate (k). The two strains presented a different growth profile. However, growth rates allow greater discernment of growth profiles. The meat line presented a higher growth rate (6.95 g/day) than the lineage for laying (3.65 g/day). The relative growth rate was higher for lineage for laying (0.15%) in relation to the lineage for meat (0.13%). The inflection point of both lines is on the first third of the growth curve (up to 15 days). All results suggest that changes in management or nutrition could optimize quail production.

scholarly journals Development and growth curve of the pine cones of Araucaria angustifolia (Bert.) O. Ktze, in the region of Curitiba - PR

2008 ◽  
Vol 51 (4) ◽  
pp. 465-469 ◽  
Author(s):  
Justina Inês Anselmini ◽  
Flávio Zanette
Keyword(s):  
Growth Rate ◽  
Growth Curve ◽  
Environmental Conditions ◽  
Maximum Growth ◽  
Araucaria Angustifolia ◽  
Pine Cone ◽  
Pine Cones ◽  
Cone Growth ◽  
Made In

The objectives of this work were to describe the development and growth rate of the pine cones of Araucaria angustifolia during and after the pollination period, to identify the period of maximum growth of the cones and the period of pollination and maturation of the pine nuts. The adult individuals were found at the Setor de Ciencias Agrarias of the UFPR, in Curitiba - PR. Collections and measurements of pine cones were made in 2003 and 2005. The diameter and the length of the pine cones were measured 15 different times in both the years. In the studied environmental conditions, the period between the pollination and maturation of the pine nuts was 20 months. The maximum pine cone growth was achieved between October and January after the pollination, and between October and April of the following year.

A New Growth Rate Measure in Identifying Extended Gompertz Growth Curve and Development of Goodness-of-fit Test

2021 ◽  
pp. 000806832110372
Author(s):  
Farhana Yeasmin ◽  
Ranadeep Daw ◽  
Bratati Chakraborty ◽  
Arindam Gupta ◽  
Sabyasachi Bhattacharya ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Curve ◽  
Goodness Of Fit ◽  
Growth Models ◽  
Broad Class ◽  
Growth Dynamics ◽  
Living Organism ◽  
Fundamental Aspect ◽  
Mathematical Form ◽  
Goodness Of Fit Test

Growth is a fundamental aspect of a living organism. Growth curves play an important role in explaining the complex dynamics of growth trajectories. The development of a large class of growth models provides more choices to explain complex growth dynamics. However, identifying a suitable growth curve from a broad class of growth models becomes a challenging task. Relative Growth Rate (RGR) is the most popular measure in the growth-related study. It serves many purposes in growth curve literature, including constructing any goodness-of-fit index of some growth dynamics. However, the goodness-of-fit test based on RGR is restricted to only simple growth models. This study aims to develop a new growth rate function, instantaneous maturity rate (IMR), which can play an important role in identifying growth models. We have explored that the measure has synergy in mathematical form with IMR. However, unlike the hazard rate, IMR is a random variable when the size/RGR variable is stochastic. We have derived the exact and asymptotic distribution of this measure under the Gaussian setup of both the size and RGR variables. We have constructed a goodness-of-fit test for the extended Gompertz growth model based on the instantaneous maturity rate. We have checked the performance of the test through simulation studies as well as real data. AMS 2010 subject classifications: 62Mxx, 92Bxx, 62P10

scholarly journals A generalized Gompertz growth model with applications and related birth-death processes

2020 ◽  
Author(s):  
Majid Asadi ◽  
Antonio Di Crescenzo ◽  
Farkhondeh A. Sajadi ◽  
Serena Spina
Keyword(s):  
Growth Model ◽  
Growth Curve ◽  
Goodness Of Fit ◽  
Gompertz Model ◽  
Death Process ◽  
Birth Process ◽  
Failure Data ◽  
First Case ◽  
Gompertz Growth Model ◽  
Birth Death

AbstractIn this paper, we propose a flexible growth model that constitutes a suitable generalization of the well-known Gompertz model. We perform an analysis of various features of interest, including a sensitivity analysis of the initial value and the three parameters of the model. We show that the considered model provides a good fit to some real datasets concerning the growth of the number of individuals infected during the COVID-19 outbreak, and software failure data. The goodness of fit is established on the ground of the ISRP metric and the $$d_2$$ d 2 -distance. We also analyze two time-inhomogeneous stochastic processes, namely a birth-death process and a birth process, whose means are equal to the proposed growth curve. In the first case we obtain the probability of ultimate extinction, being 0 an absorbing endpoint. We also deal with a threshold crossing problem both for the proposed growth curve and the corresponding birth process. A simulation procedure for the latter process is also exploited.

scholarly journals Morphological Variations of Wild Populations of Brycon dentex (Characidae, Teleostei) in the Guayas Hydrographic Basin (Ecuador). The Impact of Fishing Policies and Environmental Conditions

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1901
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Environmental Conditions ◽  
Anthropogenic Activity ◽  
Freshwater Species ◽  
Fishing Pressure ◽  
Wild Populations ◽  
Morphometric Variation ◽  
Morphological Variations ◽  
Body Development ◽  
The Impact

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.

scholarly journals Teacher Effects on Chilean Children’s Achievement Growth: A Cross-Classified Multiple Membership Accelerated Growth Curve Model

2018 ◽  
Vol 40 (3) ◽  
pp. 473-501 ◽  
Author(s):  
Lorena Ortega ◽  
Lars-Erik Malmberg ◽  
Pam Sammons
Keyword(s):  
Student Achievement ◽  
Growth Curve ◽  
Growth Models ◽  
Teacher Effects ◽  
Combined Use ◽  
Achievement Growth ◽  
Children's Achievement ◽  
Accelerated Growth ◽  
Multiple Membership ◽  
Achievement Trajectories

We investigated teacher effects (magnitude, predictors, and cumulativeness) on primary students’ achievement trajectories in Chile, using multilevel cross-classified (accelerated) growth models (four overlapping cohorts, spanning Grades 3 to 8; n = 19,704 students, and 851 language and 812 mathematics teachers, in 156 schools). It was found that teacher effects on achievement growth are large, exceeding school effects. Also, the contribution of teachers to student achievement growth was found to accumulate over time. The study advances the field by exploring teacher effects in the context of an emerging economy, contributing further evidence on the properties of teacher effects on student achievement growth and demonstrating the combined use of accelerated longitudinal designs, growth curve approaches, and cross-classified and multiple membership models.

Additive and non-additive genetic effects of growth-curve parameters of Holstein, Ayrshire and crossbred females

1994 ◽  
Vol 74 (3) ◽  
pp. 401-409 ◽  
Author(s):  
D. Perotto ◽  
R. I. Cue ◽  
A. J. Lee ◽  
A. J. McAllister ◽  
J. R. Batra ◽  
...  
Keyword(s):  
Growth Rate ◽  
Dairy Cattle ◽  
Growth Curve ◽  
Growth Traits ◽  
Individual Performance ◽  
Breeding Value ◽  
Average Lifetime ◽  
Additive Effects ◽  
Positive Effects ◽  
Maternal Performance

Crossbreeding parameters (line additive, dominance and additive × additive epistatic effects for individual and for maternal performance) on growth traits of females from a crossbreeding experiment between Holstein-based (HS) and Ayrshire-based (AS) lines were estimated by individual animal models, incorporating all known additive genetic relationships among animals, through restricted maximum likelihood and mixed-model methodologies. The growth traits [asymptotic weight (A), rate parameter (k), inflection parameter (m), average lifetime absolute growth rate (AGR), average lifetime absolute maturing rate (AMR) and average lifetime relative growth rate (RGR)] were estimated by fitting the Richards function to the observed growth curve of 3076 individuals. The statistical model included the random effect of the animal breeding value and the fixed effects of genetic group and station–year–season of birth. Results indicated that the HS exceeded (P < 0.001) the AS in additive effects for individual performance for both A and AGR. The HS exceeded (P < 0.05) the AS in additive effects for maternal performance for A. Individual heterosis was positive for A (P < 0.001) and for AGR (P < 0.01). Maternal heterosis was negative for A (P < 0.05) and positive for AMR (P < 0.05). Total heterosis (TH) had positive effects on both AGR and AMR (P < 0.05). Heterosis retained in advanced crossbred generations was not significant (P > 0.05) for any of the studied traits. The results suggest that crossbreeding designed to exploit TH can alter the shape of the growth curve of dairy cattle. Key words: Crossbreeding, dairy cattle, growth curve

Structure of Economic Growth of the Countries of the Eurasian Union

2020 ◽  
Vol 152 ◽  
pp. 112-123
Author(s):  
Oleg S. Sukharev ◽  
Keyword(s):  
Economic Growth ◽  
Growth Rate ◽  
Mixed Model ◽  
Raw Materials ◽  
Growth Models ◽  
Structural Formula ◽  
Industrial Growth ◽  
Economic Relations ◽  
Macroeconomic Analysis ◽  
Investment Structure

The purpose of the study is to determine the existing growth models of the countries of the Eurasian Union by GDP expenditures and sectors (manufacturing, transactional raw materials). The research methodology is a macroeconomic analysis of the dynamics of the main indicator of economic development — gross domestic product. The research method is a structural analysis that allows you to get a structural formula for calculating the contribution of each component of GDP to the growth rate, as well as a comparative analysis of the dynamics models of the countries in question — Armenia, Belarus, Kazakhstan, Kyrgyzstan, Russia. The result of the study is the obtained structural relationships that make it possible to measure the influence of the investment structure on the growth rate, the criteria describing economic growth with a corresponding change in the country's national wealth, as well as the identification of models of economic dynamics by the countries of the Eurasian Union. It is indicative that the transaction sector dominates in Kazakhstan and Russia, while in other countries a mixed model is found, or industrial growth as in Belarus. According to the components of GDP and expenditures of the country, either a mixed or a consumer model is found (Kyrgyzstan, Russia), however, the contribution of government spending to the growth rate is provided only in Kazakhstan. It was also revealed that the reaction to the crisis of 2009 and 2015 was fundamentally different for the countries of the Eurasian Union. The search for the factor conditions of such a prevailing dynamics, as well as the influence of union economic relations on the formation of a growth model in each country, requires an expansion of research and an analytical perspective

scholarly journals Growth curve of Atlantoscia floridana (van Name) (Crustacea, Isopoda, Philosciidae) from a Brazilian Restinga Forest

2004 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Paula Beatriz Araujo ◽  
Georgina Bond-Buckup
Keyword(s):  
Growth Rate ◽  
Growth Curve ◽  
Urban Areas ◽  
Field Data ◽  
Growth Curves ◽  
Rio Grande ◽  
Rio Grande Do Sul ◽  
Differential Growth ◽  
Estimate Life Expectancy ◽  
Males And Females

The terrestrial isopod Atlantoscia floridana (van Name, 1940) occurs from the U.S.A. (Florida) to Brazil and Argentina. In the southernmost Brazilian State, Rio Grande do Sul, the species is recorded in many localities, in urban and in non-urban areas. The growth curve of Atlantoscia floridana based on field data is presented. The specimens were sampled from April, 2000 to October, 2001 at the Reserva Biológica do Lami (RBL), Rio Grande do Sul. Captured individuals were sexed and had their cephalothorax width measured, with the data analyzed with von Bertalanffy's model. The growth curves for males and females are described, respectively, by the equations: Wt = 1.303 [1 - e-0.00941 (t + 50.37)] and Wt = 1.682 [1 - e-0.00575 (t + 59.13)]. The curves showed differential growth between sexes, where females reach a higher Wµ with a slower growth rate. Based on the growth curves it was also possible to estimate life expectancy for males and females.

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