Mathematical Modelling of the Growth of Bacillus cereus Strain wwcp1on Malachite Green Dye

In this paper, various growth models such as Von Bertalanffy, Huang, Baranyi-Roberts, Modified Gompertz, Buchnam-3-phase, Modified-Richards and Modified-Logistics, were presented in fitting and evaluating the growth of Bacillus cereus wwcp1 on Malachite green dye. The Von Bertalanffy model was found to be the best model with the lowest RMSE and highest R2 values. The Accuracy and Bias factor values were near unity (1.0). The von Bertalanffy parameters such as A (lower asymptote bacterial growth), μ (bacterial growth rate) and k (curve fitting parameter) were found to be 2.757 (95% confidence interval from 2.131 to 3.382 ), 0.287 (95% confidence interval from 0.244 to 0.329) and 4.323 (95% confidence interval from 4.285 to 4.361) respectively.

Age and growth of pompano, Trachinotus ovatus, from the Strait of Messina (central Mediterranean Sea)

This is the first paper to provide detailed information on the age and growth of Trachinotus ovatus. The size of the 244 individuals collected in the Strait of Messina ranged from 2.7 to 30.4 cm in fork length (LF) and 0.31 to 508.6 g in body mass (M). The relationship between these parameters (M - LF) was investigated and showed a good fit. Age estimation based on vertebrae and otoliths yielded similar results, suggesting a maximum age of five years. However, the precision and accuracy tests, such as percentage of agreement (PA), mean coefficient of variation (ACV) and average percent error (APE) indicated that the otolith readings (97.83% PA, 0.54% ACV and 0.38% APE) were more reliable for age estimation than vertebrae readings (82.17% PA, 5.33% ACV and 3.77% APE). The multi-model inference approach allowed us to compare different non-linear growth models. The von Bertalanffy model (L∞=29.139, k=0.496 and t0=−0.347) fitted the length-at-age data best. This species has a relatively rapid growth and an estimated longevity of five to seven years. This information could be used for management and first stock assessment studies on T. ovatus in the Mediterranean Sea.

Growth and Fecundity of Marginopora Vertebralis and Amphistegina Lobifera in Laboratory Culture

ABSTRACT The shells of large benthic foraminifers (LBF) are key contributors to the development and maintenance of coastal landforms in the Pacific as well as to Paleogene and Miocene carbonates deposited along the Neotethys Seaway and tropical Pacific islands. The current study assessed growth and fecundity of two species, Marginopora vertebralis and Amphistegina lobifera, collected from sites in Viti Levu, Fiji, based on shell diameter, shell weight, fecundity, and survival. Specimens were cultured without supplemental nutrients or food for 15 months under controlled laboratory conditions. Physicochemical parameters, including salinity, alkalinity, pH, and temperature, varied by <5% throughout the experiment. Asexual reproduction by M. vertebralis produced ∼270 offspring per brood, while A. lobifera produced ∼500 offspring per brood. The minimum size at reproduction for M. vertebralis was 15 mm, and A. lobifera reproduction occurred at diameters ≥0.9 mm. These observations were consistent with those of previous studies that predicted asexual fecundity related to parent size. Four non-linear mathematical functions (exponential, Gompertz, logistic, and von Bertalanffy) were compared to describe the age-weight relationship for each species. Results revealed that the logistic model best fits M. vertebralis growth, and von Bertalanffy model best fits A. lobifera growth. The growth model for A. lobifera predicted trends in juvenile growth and maximum size consistent with a previously published von Bertalanffy model based on cultures in which the foraminifers were provided nutrient sources and grew much faster than those observed in this study. These observations support published hypotheses that many LBF are exceptionally well-adapted to extreme oligotrophy, a characteristic that accounted for their dominance as carbonate producers in the Paleogene and Miocene of the Neotethys and Pacific islands.

Growth parameters of Brycinus longipinnis (Günther, 1864) from the Aghien Lagoon (South East of Côte D’ivoire)

The growth of Brycinus longipinnis caught at Aghien Lagoon was studied between June 2014 and May 2015 through growth type, condition factor and growth parameters according to the Von Bertalanffy model. Sampling was conducted using experimental fisheries. Growth type was determined from the length-weight relationship and growth parameters according to the Von Bertalanffy model from the FiSAT software. The growth was of negative allometric type (b = 2.59). The Brycinus longipinnis population grows faster towards the asymptotic length ((L∞ = 92.40 mm SL) with a growth coefficient K of 0.36 year-1. It is also a long-lived fish species with maximum longevity (tmax) of 8.32 years.

Growth Models for Covid-19 Death Figures of Turkey

This paper presents modeling of the COVID-19 pandemic deaths to understand behavior of it, predict the peak point of the deaths and cases and produces a short-term forecast using the growth models for the reported data of Turkey. The data which is used in this study are gathered of daily announced by Minister of Health. Von Bertalanffy model has outperformed to the other models considered in this study. However, exponential model has predicted the total deaths and total cases better than the others. And, exponential model has given the best prediction errors among them regarding to the death and positive case figures for last months. Observed data have tended to increase since the last days of August. This could mean that the COVİD-19 threat has reached to a critical stage to crack down on prevention of pandemics spread. Or it could sign the beginning of a second wave of epidemics. More studies must be realized to learn more about the pandemic when the new data are available.

PARAMETERIZATIONS OF THE VON BERTALANFFY MODEL FOR DESCRIPTION OF GROWTH CURVES

The growth curves of animals, in general, have an “S” shape, also known as sigmoidal curves. This type of curve is well fitted by nonlinear regression models, including von Bertalanffy’s model, which has been widely applied in several areas, being presented in literature through different parameterizations, which in practice, can complicate its understanding, affect nonlinearity measures and inferences about parameters. To quantify the nonlinearity present in a Bates and Watts model, a geometric concept of curvature has been used. The aim of this work was to analytically develop three parameterizations of the von Bertalanffy’s nonlinear model referring to its nonlinearity, implications for inferences and to establish relationships between parameters in the different ways of expressing the models. These parameterizations were adjusted to the growth data of sheep. For each parameterization, the intrinsic and parametric curvature measurements described by Bates and Watts were calculated. The parameterization choice affects nonlinearity measures, consequently, influences the reliability and inferences about estimated parameters. The forms most used in literature showed the greatest deviations from linearity, showing the importance of analyzing these measures in any growth curve study. Parameterization should be used in which the b estimate represents the abscissa of the inflection point, as it presents minor linearity deviations and direct biological interpretation for all parameters.

Growth rates in two natural populations of Gasterosteus aculeatus in northwestern Spain: relationships with other life history parameters

We analysed growth rates of two natural populations of the three–spined stickleback fish, Gasterosteus aculeatus, in Galicia (north–west of Spain) where it has a strictly annual life cycle. We used the von Bertalanffy growth model to estimate nonlinear function for length–at–age data sets. These European peripheral populations reach the highest growth rates (k of the von Bertalanffy model > 0.4 month–1) known for this species. Instantaneous mortality rates and fecundity were computed using von Bertalanffy model parameters for each population. Mortality rates found in Galician populations were 2.0–2.3 higher times than those observed in general for Gasterosteidae. Combining both mortality and fertility, different intermediate fitness optima in each population were obtained for mature females. Overall, these differences in life history compared to other studied populations of sticklebacks can be interpreted as local adaptations to a Mediterranean climate type with high degree–days. Consequently, these populations at the edges of the species’ range may have adapted to the unique environmental conditions and may be of interest in ecology and conservation.

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.