Nonlinear Growth Models Research Articles

Allocation of maize varieties according to temperature for use in mechanical kernel harvesting in Ningxia, China

The reasonable assessment of maize varieties in different ecological regions can allow temperature resources to be fully exploited and reach the goal of high yield and efficiency and is thus an important direction of modern maize development in China. In this study, a logistic power nonlinear growth model was used to simulate the accumulated temperature required for kernel dehydration to moisture contents of 25%, 20%, and 16% for various maize cultivar, which were divided into six types based on the accumulated temperature required for kernel dehydration to a moisture content of 25%. The relationship between the yield of maize cultivars and the accumulated temperature required for kernel dehydration to a moisture content of 25% was found to follow a unary function model. Changing the planted maize variety was found to increase economic returns by more than 7000 RMB/hm2 in Ningxia, Northwest China. Under the conditions of mechanical grain harvesting, economic benefits can be further increased by means of selecting high yields and fast-dehydrating varieties, selling when the grain dehydration is below 16%. A better way to achieve grain dehydration to a moisture content below 16% is to postpone the harvest date as much as possible rather than drying after the harvest at physiological maturity. The areas of various types of maize varieties can be dehydrated to moisture contents of 25%, 20%, and 16% were marked. Based on the distribution of heat resources in different regions of Ningxia from the normal sowing date to October 31 before winter irrigation, the appropriate cultivars for various regions in the province were determined based on production benefits. Therefore, in different areas of Ningxia, selecting suitable maize varieties according to temperature resources can reach a high yield and mechanical kernel harvesting, and ultimately obtain higher economic benefits. Keywords: maize, dehydration, grain yield, economic return, mechanical kernel harvesting DOI: 10.25165/j.ijabe.20201401.6035 Citation: Li H Y, Wang Y H, Xue J, Xie R Z, Wang K R, Zhao R L, et al. Allocation of maize varieties according to temperature for use in mechanical kernel harvesting in Ningxia, China. Int J Agric & Biol Eng, 2021; 14(1): 20–28.

Genetically Determined Differences in Annual Shoot Elongation of Young Norway Spruce

The annual shoot elongation could be described by a non-linear growth model to characterize differences in its dynamics among spruce genotypes, the effect of each shoot elongation phase on the total shoot length, and the genetic differences for a particular growth phase. The terminal shoot length was measured in two open-pollinated progeny trials of Norway spruce on average once per week during the ninth growing season. For the analysis, 10% of families with the longest annual increment (shoot) and 10% with the shortest were selected for each trial. The Gompertz model was fitted to individual tree data, and the mean values of its coefficients for each group of families were obtained. Family significantly (p < 0.001) affected total shoot length and all growth rhythm parameters, with similar trends reported in both studied sites. Heritability of Gompertz model coefficients in most cases exceeded that of the tree height. The superior10% of families started shoot elongation slightly but non-significantly earlier (all p > 0.05) than the other groups of families and had more intense shoot elongation (mm per day) during the entire growing season. A strong negative relation was found between the slope coefficient of the cumulative shoot elongation lines and the total height increment. The group of families with the longest increment had flatter relative shoot elongation lines, indicating relatively more evenly distributed growth within the growing season. In contrast, families with the shortest increment tended to accumulate a higher proportion of height increment during the active growth phase and reduced relative growth intensity more rapidly. The 10% of families with the largest annual increment showed superior characteristics in all shoot elongation phases, resulting in 30–40% longer shoots compared to the 10% of families with the smallest annual increment. The significant differences in Gompertz model coefficients indicate that genotypes with favorable growth patterns might be selected.

A Seasonal Dynamic Measurement Model for Summer Learning Loss

Abstract Research conducted in US schools shows summer learning loss in test scores. If this summer loss is not incorporated into models of student ability growth, assumptions will be violated because fall scores will be overestimated and spring scores will be underestimated, which can be particularly problematic when evaluating teacher or school effectiveness. Statistical methods for summer loss have remained relatively undeveloped and often rely on lagged-time or piecewise models, which commonly saturate the mean structure and become reparameterizations of empirical means. Compound polynomial models have recently been introduced and simultaneously model within-year and between-year growth processes in test scores. However, these models operate with polynomial functions of time, which can have limited interpretative utility. In this article, we propose incorporating seasonality within the dynamic measurement modelling (DMM) framework. DMM reparametrizes non-linear growth models to directly estimate interpretable quantities (e.g. learning capacity as an upper asymptote on growth). Borrowing from ecological models proposed for body mass of cold-climate species, we show how DMM can incorporate seasonality to provide more interpretable parameters as well as to explicitly include summer learning loss as a parameter in the model.

Analytical Solution of Nonlinear Fractional Volterra Population Growth Model Using the Modified Residual Power Series Method

In this paper, we introduce an analytical approximate solution of nonlinear fractional Volterra population growth model based on the Caputo fractional derivative and the Riemann fractional integral of the symmetry order. The residual power series method and Adomain decomposition method are implemented to find an approximate solution of this problem. The convergence analysis of the proposed technique has been proved. A numerical example is given to illustrate the method.

Simple Surveillance Is Not So Simple

The fate of the distal aorta is largely unknown after acute type A repair. In this issue of The Annals of Thoracic Surgery, the study by Ismaguilova and colleagues1Ismaguilova A. Martufi G. Gregory A.J. et al.Multidimensional analysis of descending aortic growth after acute type A aortic dissection.Ann Thorac Surg. 2021; 111: 615-622Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar identified a group of 40 patients who had undergone type A dissection repair (DeBakey I/II) with adequate postoperative computed tomography scan angiography imaging. Using 3-dimensional (3D) reconstructions and a centerline, the diameters of these aortas were measured at 100 points along the aorta from the subclavian to the renals. These diameters were then tracked over time with the aid of a 3D nonlinear growth model. This study found that the distal aorta grew considerably after DeBakey type I repair, whereas after DeBakey type II repair the aorta did not. The largest diameter of the aorta grew much slower than the that of the fastest growing segment (type 1: 0.6 versus 3.8 mm/y; type 2: 0.03 versus 1.8 mm/y). The aorta at the maximum diameter grew at about the same rate in both DeBakey groups, whereas the DeBakey type I group had a higher rate of growth at the fastest growing slice of aorta. This area typically did not correlate with the original area of maximum diameter. Another, similar study by Martufi and colleagues2Martufi G. Auer M. Roy J. et al.Multidimensional growth measurements of abdominal aortic aneurysms.J Vasc Surg. 2013; 58: 748-755Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar analyzed abdominal aortic aneurysms using similar centerline measurements and software and came to similar conclusions. Other studies found that abdominal aortic growth is more exponential in nature,3Hirose Y. Hamada S. Takamiya M. Predicting the growth of aortic aneurysms: a comparison of linear vs exponential models.Angiology. 1995; 46: 413-419Crossref PubMed Scopus (35) Google Scholar and that it also occurs in an irregular,4Vega de Céniga M. Gómez R. Estallo L. et al.Analysis of expansion patterns in 4-4.9 cm abdominal aortic aneurysms.Ann Vasc Surg. 2008; 22: 37-44Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar “staccato” fashion.5Kurvers H. Veith F.J. Lipsitz E.C. et al.Discontinuous, staccato growth of abdominal aortic aneurysms.J Am Coll Surg. 2004; 199: 709-715Abstract Full Text Full Text PDF PubMed Scopus (70) Google Scholar This rebuts a few older studies suggesting that the aorta undergoes slow, linear growth over time. Halstead and colleagues6Halstead J.C. Meier M. Etz C. et al.The fate of the distal aorta after repair of acute type A aortic dissection.J Thorac Cardiovasc Surg. 2007; 133: 127-135Abstract Full Text Full Text PDF PubMed Scopus (236) Google Scholar made this conclusion based on follow-up of 89 patients after undergoing type A repair (median growth: 1.0 mm/y). They found that a patent false lumen and larger initial size were associated with faster expansion (1.2 versus 0.8 mm/y). More recent studies make this analysis of progressing aortic diameters seem crude, even though Halstead and coworkers used segmental analysis and linear modeling. However, this older study had incomplete computed tomography follow-up and probably underestimated aneurysm growth. The only data they had for comparison were decades old7Haverich A. Miller D.C. Scott W.C. et al.Acute and chronic aortic dissections—determinants of long-term outcome for operative survivors.Circulation. 1985; 72: II22-II34PubMed Google Scholar and probably no longer useful. We must commend the authors for arguing, probably correctly, that one cannot simply examine the widest part of the remaining aorta at follow-up and be complacent. As our imaging methods move toward 3D rendering, our analysis of the aorta after surgery must evolve as well (especially after a patient survives a type A dissection). Changes in the aortic diameter are likely an interplay among regional geometry, flow dynamics, and local inflammatory or genetic changes. It would have been interesting to see how false lumen patency influenced the findings and affected all of these diameters, but that would have been exceedingly complex. Unfortunately, the lack of clinical data for these patients makes this more of a mathematical imaging study. We have no idea what these small changes in aortic size mean clinically. With a larger sample size and more clinical data, we may be able to predict stability versus degeneration better. Multidimensional Analysis of Descending Aortic Growth After Acute Type A Aortic DissectionThe Annals of Thoracic SurgeryVol. 111Issue 2PreviewAfter repair of acute type A aortic dissection, typical geometric variables of conventional aortic surveillance focus on maximum diameter and its rate of growth, potentially missing important geometric changes elsewhere. We determined additional information provided by a semiautomated, 3-dimensional (3D), nonlinear growth model of the descending thoracic aorta after repair of type A aortic dissection. Full-Text PDF

Multiphasic nonlinear mixed growth models for laying hens

Appropriate evaluation of BW and gain during rearing is required for optimal extended laying performance in laying hens. The objective of this study was to compare monophasic, diphasic, and triphasic Gompertz and logistic models describing BW and gain in individually fed free-run laying hens and to study the variation between individuals in shape parameters. Fifteen Lohmann Brown Lite hens were fed ad libitum from week 0 to 43 with a precision feeding system, measuring feed intake and BW individually in a group housed setting. Random variables related to mature weight and timing of maximum gain during the pubertal growth phase were introduced into the multiphasic model for BW with the best fit. For both the weight-age and gain-age functions, the diphasic and triphasic Gompertz and logistic model models fitted the data better than the monophasic models. The Gompertz model was able to identify the ages at the highest gain at similar time points for both BW and gain, whereas the logistic models failed to do so. The derivative of the multiphasic Gompertz models for the gain-age relationship identified age at the highest gain at similar ages as compared with the logistic models for gain. The mixed models predicted that the individual mature BW ranged from 1.83 kg to 2.10 kg and the variability in the timing of the highest rate of gain during the pubertal growth spurt ranged from 15.26 wk to 19.79 wk. Including random terms associated with the mature BW and the second inflection point of the diphasic Gompertz growth model allowed for identification of variability in the growth curve shape between individuals, which can be a tool to study the relationship between the individual growth curve shape and performance parameters.

Comparison of nonlinear growth models and factors affecting body weight at different ages in Toy Poodles

Limited information is available to evaluate optimal growth in Toy Poodles. This work aimed at comparing three growth curves, proposing centile charts and developing a model to estimate the adult body weight (BW) in Toy Poodles. A total of 65 puppies (male = 30, female = 35) born in the same breeding centre were used. BW at birth and, weekly BW, for 53 weeks, BW of parents, litter size, type of management, daily activity and neutering were recorded. Forty-six puppies were sold, and their data were reported by the new owners. Three growth curves (i.e. Hawthorne, Brody and Gompertz) were constructed and compared; Linear Mixed Models including demographic characteristics and management habits were built. The BW at birth was 154 ± 35 g and adult BW was 3208 ± 860 g. Based on the goodness-of-fit and accuracy indices, Gompertz was the best growth model and was selected to plot centile curves based on sex. Toy Poodles achieved 50% of their adult weight at 11–12 weeks, with an overall growth rate of 11.8%. Adult BW was affected by birth BW (p < .01), sex (p < .05) and mother’s BW (p < .01) and their effects varied depending on the age. Extrinsic factors, including litter size, type of management and daily activity were less significant, probably due to the standardised and high-level management of these Toy Poodles. These new and applicable tools for monitoring the growth and predicting adult BW could be useful for veterinarians, breeders and owners for early diagnosis of poor health and welfare. Subject classification codes: companion animals sections Highlights Performance of three logistic models for describing the growth curve in Italian Toy Poodles were compared Based on the goodness of fit and accuracy indices, Gompertz was the best growth model The centile growth curves were constructed for males and females using the Gompertz Adult body weight (BW) was mainly affected by the sex and birth BW, and less by BW of the parents and litter size Monitoring BW of puppies may be useful to enhance their health and welfare

Predictive effects of pubertal timing and tempo on adolescent depressive symptoms: a 6-year prospective cohort study

Objective: To examine the prospective association of pubertal timing and tempo with depressive symptoms in adolescents. Methods: Since 2013, 2 084 students in grade 1-3 were selected from two primary schools in Bengbu, Anhui Province were selected by using convenience sampling method to establish the adolescence pubertal development cohort. Followed up for 6 years, physical examination, secondary sexual development evaluation (testicular volume for boys and breast development for girls) and depressive symptoms were evaluated biennially. Non-linear growth model was used to estimate pubertal timing and tempo for boys and girls respectively. Depressive symptoms were interviewed by using the Short Mood & Feeling Questionnaire (SMFQ) at baseline and Mood & Feeling Questionnaire (MFQ) during follow-up for students in grade 1-2. Children Depression Inventory (CDI) was used for students in grade 3 at baseline and during follow-up. Depressive symptom scores were standardized by using the Z-score method. Multivariate linear regression model was used to analyze the predictive effects of modeling pubertal timing and tempo on depressive symptoms of adolescence boys and girls. Results: There were 1 909 students with complete questionnaire and puberty development information, including 1 052 boys (59.19%) and 857 girls (43.81%), with average age about (13.94±0.87) years and 91.60 percent follow-up rate. The average modeling pubertal timing of girls (11.25 years) was earlier than that of boys (12.70 years), and the average pubertal tempo of girls about 1.47 Tanner stage/year was faster than that of boys about 1.28 Tanner stage/year. After controlling for depressive symptoms, maternal education and adverse childhood experiences at baseline and age, body mass index (BMI) classification and sleep time during follow-up, this predictive effect of pubertal timing and tempo on depressive symptoms was only significant among girls. Compared with girls with on time pubertal timing, girls in the delay timing group had a lower level of depressive symptoms (β=-0.19, 95% CI:-0.34,-0.01). Compared with girls in average pubertal tempo group, the fast tempo group associated with an increasing risk of depressive symptoms (β=0.23, 95%CI: 0.05, 0.40), while the slow tempo group associated with an decreasing risk of depressive symptoms (β=-0.21, 95％CI:-0.39,-0.03). Insignificant effects were found in puberty timing and tempo on depressive symptoms of boys (P>0.05). Conclusion: Fast pubertal tempo increases the risk of development of depressive symptoms of adolescent girls. There is no predictive effect of pubertal timing and tempo on depression symptoms of adolescent boys.

Does the financial system support economic growth in times of financialisation? Evidence for Portugal

ABSTRACT This paper conducts a time series econometric analysis in order to examine empirically the relationship between the financial system and economic growth in Portugal from 1977 to 2016. The Portuguese financial system has experienced a strong wave of privatisations, liberalisations and deregulations since the adhesion of Portugal to the European Economic Community in 1986, which has not favoured a sustained path of strong economic growth since then. The paper estimates a linear growth model and a non-linear growth model, which includes four proxies for the financial system (money supply, credit, financial value added and stock market capitalisation) and four further control variables (inflation, government consumption, trade openness and education). The paper finds a negative linear relationship between the banking system and Portuguese economic growth, a positive linear relationship between the stock markets and Portuguese economic growth, a concave quadratic relationship between the banking system and Portuguese economic growth, and a convex quadratic relationship between the stock markets and Portuguese economic growth. This suggests that Portuguese policy makers should canalise efforts to decrease the importance of banking system and to increase the importance of stock markets in order to support more robust economic growth in the coming years.

A Novel 2-Stage Fractional Runge–Kutta Method for a Time-Fractional Logistic Growth Model

In this paper, the fractional Euler method has been studied, and the derivation of the novel 2-stage fractional Runge–Kutta (FRK) method has been presented. The proposed fractional numerical method has been implemented to find the solution of fractional differential equations. The proposed novel method will be helpful to derive the higher-order family of fractional Runge–Kutta methods. The nonlinear fractional Logistic Growth Model is solved and analyzed. The numerical results and graphs of the examples demonstrate the effectiveness of the method.

Multidimensional Analysis of Descending Aortic Growth After Acute Type A Aortic Dissection

After repair of acute type A aortic dissection, typical geometric variables of conventional aortic surveillance focus on maximum diameter and its rate of growth, potentially missing important geometric changes elsewhere. We determined additional information provided by a semiautomated, 3-dimensional (3D), nonlinear growth model of the descending thoracic aorta after repair of type A aortic dissection. Computed tomographic angiography data were retrospectively collected after hemiarch repair of type A aortic dissection. The descending aorta was systematically reconstructed to generate a 3D model made up of individual segments. The baseline and follow-up diameters were measured semiautomatically for each segment, and the nonlinear interval growth was determined. The fastest growing segment expanded at a rate of 3.8 mm/y (interquartile range, 2.2 to 5.4 mm/y) vs 0.6 mm/y (interquartile range,-0.3 to 1.7 mm/y) when measured at the original site of maximum diameter (P < .01). The maximum baseline diameter was a poor predictor of location with fastest growth (r= 0.10, P > .1). Using the society recommended growth limits, a greater proportion of patients would be considered "at risk" when assessed by our method vs conventional surveillance measures. Our model identifies areas of rapid aortic growth after repair of type A dissection that would likely be missed using current surveillance techniques. The increased precision, resolution, and reproducibility provided by our technique may improve on limitations of current surveillance techniques, provide novel geometric data on aortic remodeling, and contribute to the pursuit of a comprehensive patient-specific approach to aortic risk stratification.

First-passage times and normal tissue complication probabilities in the limit of large populations

The time of a stochastic process first passing through a boundary is important to many diverse applications. However, we can rarely compute the analytical distribution of these first-passage times. We develop an approximation to the first and second moments of a general first-passage time problem in the limit of large, but finite, populations using Kramers–Moyal expansion techniques. We demonstrate these results by application to a stochastic birth-death model for a population of cells in order to develop several approximations to the normal tissue complication probability (NTCP): a problem arising in the radiation treatment of cancers. We specifically allow for interaction between cells, via a nonlinear logistic growth model, and our approximations capture the effects of intrinsic noise on NTCP. We consider examples of NTCP in both a simple model of normal cells and in a model of normal and damaged cells. Our analytical approximation of NTCP could help optimise radiotherapy planning, for example by estimating the probability of complication-free tumour under different treatment protocols.

A statistical modeling approach of area, production and productivity of maize crop in Dindigul district

The present study has been undertaken to identify the best Linear and Non-Linear growth models, time series models like ARIMA to predict the future forecasts (up to 2021 A.D) in area, production and productivity of Maize during the study period from 1990-91 to 2016-17. The best fitted model was chosen based on model selection criteria like highest coefficient of determination (R2), Adjusted R2 and with least MAPE, RMSE and MAE values for the purpose of future forecasts up to 2021 A.D. The time series data pertaining to area, production and productivity of Maize in Dindigul district of Tamil Nadu were collected from Seasonal crop report of Tamil Nadu and Ministry of Agriculture, Govt. of India, www.indiastat.com for the period of 27 years i.e., from 1990 to 2016.The analysis of area, production and productivity of Maize in Dindigul district of Tamil Nadu revealed the following features over a period of time. It is observed that the average area, production and productivity under maize in Dindigul district of Tamil Nadu during the study period were 27128 thousand hectares, 97686 thousand tonnes and 3417 kg/ ha respectively. The future forecasts by cubic model were indicated that there would be substantial decreasing in area and production and increasing trend in productivity in the future. It was observed that the forecasted area by 2021 AD would be 6706.26 hectares hectares. The forecasted production and productivity would be 125781.96 tonnes and 9838.36 kg /ha respectively by 2021 AD.

Selection of nonlinear mixed models for growth curves of dairy buffaloes (Bubalus bubalis)

AbstractThe determination of livestock growth patterns is important for meat or milk production systems, and nonlinear models are used to summarize and interpret the information. The aim of this study was to more accurately estimate growth curve parameters in buffalo cows by evaluating and selecting nonlinear mixed models that employ different types of residuals and include or not contemporary groups (CG) as a covariate. Weight records from 720 animals obtained over a period of 60 months were used. The growth curves were fit using nonlinear mixed-effects models. The Bertalanffy, Gompertz and Logistic models were evaluated. Modelling residuals using four structures (constant, combined, exponential and proportional) and the inclusion or not of CG in the models were also evaluated. The Akaike information criterion (AIC) and Bayesian information criterion (BIC) were used to select the model. In addition to estimating the parameters of the nonlinear growth models and their correlations, the instantaneous growth rate and inflection point were obtained. The Bertalanffy model with a combined residual structure and CG exhibited the lowest AIC and BIC values. Asymptotic weight (A) estimates ranged from 621.8 to 742.1 kg, and the maturity rate (k) ranged from 0.068 to 0.115 kg/month. The correlation between A and k ranged from −0.32 to −0.82 among the models evaluated. The selection criteria indicated that the Bertalanffy model was the most suitable for growth curve analysis in buffaloes.

Application of Piecewise and Polynomial non-linear latent growth models for the modeling of trajectories of career maturity

Application of Piecewise and Polynomial non-linear latent growth models for the modeling of trajectories of career maturity

Comparison of four nonlinear growth models in Creole chickens of Mexico

Animal growth is a complex and dynamic process that involves physiological and morphological changes from hatching to maturity. It is defined as the increase in body size per time unit. Mathematical functions, called growth models, have been used to explain growth patterns. The aim of this study was to compare the Gompertz-Laird, logistic, Richards, and Von Bertalanffy growth models to determine which best fits the data of the Creole chickens (CC). Three hundred forty-seven CC were individually weighed from hatching until 177 D of age. Birds were fed a starter diet (0–18 D of age; 19% crude protein (CP) and 3,000 kcal of ME/kg) and grower diet (19–177 D of age; 18% CP and 2,800 kcal of ME/kg). Data were analyzed using PROC NLIN to fit the nonlinear growth curve. The coefficient of determination (R2), Akaike information criteria (AIC), and Bayesian information criteria (BIC) were used to compare the goodness of fit of the models. The Von Bertalanffy (R2: 0.9382, 0.9415; AIC: 2,224.1, 2,424.8; BIC: 2,233.5, 2,434.3, for females and males, respectively) was the model that best explained growth of the birds. On the other hand, both the Gompertz-Laird and logistic models overestimated hatching BW and underestimated the final BW of CC. Females reached age of maximum growth faster than males. The asymptotic weight was higher in males (3,011 g) than in females (2,011 g). Body weight at inflection point was 892 g at 64 D of age for males and 596 g at 54 D for females. In conclusion, the best fit of the data was obtained with the Von Bertalanffy growth model; the information is intended to serve as the basis for utilizing CC.

Roughening in Nonlinear Surface Growth Model

The aim of this paper is to examine the coarsening process in the evolution of the surface morphology during molecular beam epitaxy (MBE). A numerical approach for modeling the evolution of surface roughening in film growth by MBE is proposed. The model is based on the nonlinear differential equations by Kuramoto–Sivashinsky (KS) namely, KS and CKS (conserved KS). In particular, we propose a “combined version” of KS and CKS equations, which is solved as a function of a parameter r for the 1 + 1 dimensional case. The computation provides film height as a function of space and time. From this quantity the change of the width of the film over time has numerically been studied as a function of r. The main result of the research is that the surface width is exponentially increasing with increasing time and the change in surface width for smaller r values is significantly greater over longer time interval.

Dynamics of social interactions, in the flow of information and disease spreading in social insects colonies: Effects of environmental events and spatial heterogeneity

The relationship between division of labor and individuals’ spatial behavior in social insect colonies provides a useful context to study how social interactions influence the spreading of elements (which could be information, virus or food) across distributed agent systems. In social insect colonies, spatial heterogeneity associated with variations of individual task roles, affects social contacts, and thus the way in which agent moves through social contact networks. We used an Agent Based Model (ABM) to mimic three realistic scenarios of elements’ transmission, such as information, food or pathogens, via physical contact in social insect colonies. Our model suggests that individuals within a specific task interact more with consequences that elements could potentially spread rapidly within that group, while elements spread slower between task groups. Our simulations show a strong linear relationship between the degree of spatial heterogeneity and social contact rates, and that the spreading dynamics of elements follow a modified nonlinear logistic growth model with varied transmission rates for different scenarios. Our work provides important insights on the dual-functionality of physical contacts. This dual-functionality is often driven via variations of individual spatial behavior, and can have both inhibiting and facilitating effects on elements’ transmission rates depending on environment. The results from our proposed model not only provide important insights on mechanisms that generate spatial heterogeneity, but also deepen our understanding of how social insect colonies balance the benefit and cost of physical contacts on the elements’ transmission under varied environmental conditions.

Effects of cadmium toxicity on sesame seed germination explained by various nonlinear growth models

This experiment was conducted to evaluate the effects of cadmium toxicity on the seed germination properties of sesame cultivars (Halil, Nazok Shakhei, Oltan, and Yellow White) using non-linear growth models. Seeds were germinated in petri dishes (90 mm diameter), with a double layered of filter paper soaked in distilled water as control treatment or cadmium (CdSO4) solutions in concentrations of 0, 100, 200, 400, 600, 800 and 1000 ppm. Each treatment was replicated four times and included 50 seeds in each petri dishes. Hyperbolastic growth models for the description of seed germination data were compared to Richards, Weibull, Logistic and Gompertz models. Our results revealed that all studied cultivars were germinated at the cadmium-polluted germination medium to a maximum of 200 ppm without reduction in germination fraction, while seed germination rate was decreased at this concentration compared to 0 and 100 ppm. Increasing cadmium concentration resulted in the germination fraction reduction from 1 to 0.4 at the 400 ppm. The recommended hyperbolastic growth model was type III or (H3) as it provided the best model with the lowest Corrected Akaike Information Criterion for cv. Halil (AICc = −14.6) and cv. Nazok Shakhei, (AICc = −14.2).

Effect of insulin-like growth factor 1 gene on growth traits of Kejobong goat and its growth analysis.

Aim:This study aimed to identify the effect of the insulin-like growth factor 1 (IGF1) gene on growth, to uncover the genetic marker at the IGF1 gene, and to predict growth performance by analyzing growth models of Kejobong goats based on their genotype.Materials and Methods:DNA and records of body weight (BW) and body measurements (BM) of Kejobong goats were collected, the IGF1 gene was amplified from the DNA template by polymerase chain reaction (PCR); the PCR products were then sequenced to determine single nucleotide polymorphisms (SNP). Linear mixed model (LMM) was used to analyze the association between SNP and growth traits. Four non-linear growth models were analyzed using non-LMM to describe the growth model and to compare the growth within genotypes.Results:An SNP at intron 4 (g5752G→C) genotyped into GG and CC was significantly associated with BW and BM. Goats of genotype GG had a significantly higher BW and BM (p<0.05) than those of genotype CC. Growth analysis showed that the von Bertalanffy model was the most fit for describing BW, the Brody model for chest width and hip height, the Gompertz and Logistic models for heart girth, and the von Bertalanffy and Gompertz models for hip width.Conclusion:An SNP at intron 4 of the IGF1 gene was associated with the growth trait and was usable as a genetic marker candidate for improvement of growth traits of Kejobong goats while von Bertalanffy model provides proper and accurate estimates of parameters to describe the growth performance of Kejobong goats.