Comparative assessment of growth curves in Brazilian white Morada Nova hair sheep breed.

The Morada Nova sheep breed is essential for the economy of the semi-arid region of Northeast Brazil, standing out for its adaptability, resistance to parasites and reproductive ability. However, the white variant is endangered, highlighting the importance of studies on its productivity to support conservation efforts. This study focuses on the growth curve of the Morada Nova sheep breed, using nonlinear models and analyzing flock profiles. Total of 764 observations of 165 animals from four farms in Ceará and Rio Grande do Norte, Brazil, were analyzed. Canonical discriminant analysis (CDA) was used for the exploratory analysis and four nonlinear models were used to study the growth curve. Weight from birth to 270 days of age, absolute growth rate (AGR), and the impact of sex on growth curves were assessed. Sex and farm are significant discriminating variables (P < 0.05) for the studied effects (weight and age). Weight was the primary phenotypic biomarker that discriminated between the two indicators, while age was a discriminating indicator only for the core effect. The Gompertz model was the most efficient, presenting the lowest residuals and greatest convergence. The study reveals new information about the growth of Morada Nova sheep, the white variety, including weight differences between the sexes at all analyzed ages and an inflection point before 90 days of age. These discoveries contribute to the understanding of the breed's growth and help in the formulation of conservation strategies.

Bone Growth and Meat Quality of Quails Submitted to Different Lighting Programs

The present study was executed to evaluate the effect of lighting programs for meat quails on their bone growth and development. A total of 1500 sexed European quails (Coturnix coturnix coturnix) were distributed using a completely randomized design in a 2 × 3 factorial arrangement, with two sexes and three lighting programs (natural, intermittent, and continuous) with five replicates of 50 quails. The lighting programs were applied in the period from 7 to 49 d of age. Weekly slaughterings were performed to remove the tibiotarsus and femur and subsequently determine weight, length, dry and mineral matter content. The growth and deposition curves of dry and mineral matter in the bones were obtained using the Gompertz model. There was no significant interaction between lighting programs and sex for the estimates of the Gompertz curve parameters of all variables studied. There was an effect of the lighting programs only on the time needed to reach the maximum deposition rate of the growth curve and dry and mineral matter deposition. Females showed higher weight and deposition of mineral matter at maturity, and took longer to reach the maximum deposition rate value for these variables. There was influence of the lighting programs on resistance and bone deformity of the tibiotarsus. For quails raised in the tropical region, a natural or intermittent lighting program must be used, as it does not compromise the development of bones and assures bone quality.(AU)

Anaerobic co-digestion of leachate and glycerol for renewable energy generation.

Anaerobic digestion is a versatile biotechnology that produces bioenergy, biogas, from wastewater. Biogas production and wastewater treatment can be optimized by associating substrates with complementary characteristics. In this context, the aim of this study was to evaluate the performance of the anaerobic co-digestion of different contents of landfill leachate and crude glycerol compared to the organic matter removal and specific biogas production, the effects of the factors (time, glycerol content and substrate/inoculum ratio) and their interactions on kinetic parameters of specific biogas production using the modified Gompertz model. A Central Composite Rotational Design (CCRD) was performed for the experimental variables: time (16.6, 20, 25, 30 and 33.4 days), glycerol content (0.43, 0.70, 1.10, 1.50 and 1.77%) and substrate/inoculum ratio (0.23, 0.30, 0.40, 0.50 and 0.57 g COD/g VSS). From the optimization, it was possible to maximize the efficiency of organic matter removal (90.15%) and specific biogas production (403.15 mL/g VSS) in the conditions of 33.2 days, glycerol content of 1.71% and substrate/inoculum ratio of 0.37 g COD/g VSS. Concerning the modified Gompertz model of the optimal condition performed, an average of 20.3 times higher specific biogas production was obtained when compared to the monodigestion of leachate. Therefore, the association of leachate and glycerol was found to be feasible in terms of stability, biodegradability and biogas production.

Closed-form expressions to Gompertz-Makeham life expectancies: a historical note / Expressões de forma fechada para as expectativas de vida de Gompertz-Makeham: uma nota histórica / Expresiones de forma cerrada a las esperanzas de vida de Gompertz-Makeham: una nota histórica

Abstract Results well known in the actuarial community about closed-form expressions to Gompertz and Gompertz-Makeham life expectancies for a person aged x are still being independently rediscovered to this day. This note seeks to acknowledge previous results about closed-form expressions to Gompertz-Makeham life expectancies, especially in the actuarial science field, hoping to stimulate interdisciplinarity and provide the background for further developments, especially since the derivation of closed-form expressions for life expectancy (and annuities) based on particular mortality laws are matters of interest for multiple fields such as actuarial science, biology, demography, statistics among others.

Resumo Resultados bem conhecidos pela comunidade atuarial sobre expressões de forma fechada para esperança de vida de Gompertz e Gompertz-Makeham para uma pessoa de idade x ainda estão sendo redescobertos de forma independente nos dias atuais. Esta nota visa fornecer algum reconhecimento aos resultados anteriores sobre expressões de forma fechada para expectativa de vida de Gompertz e Gompertz-Makeham, especialmente no campo das ciências atuariais, na esperança de estimular a interdisciplinaridade e fornecer o pano de fundo para novos desenvolvimentos, em especial porque a derivação de expressões de forma fechadas para expectativa de vida (e anuidades) com base em leis de mortalidade despertam o interesse de várias áreas, como ciências atuariais, biologia, demografia, estatística, entre outras.

Resumen Los resultados bien conocidos por la comunidad actuarial sobre las expresiones de forma cerrada de las esperanzas de vida de Gompertz y Gompertz-Makeham para una persona de edad x todavía se están redescubriendo de forma independiente en la actualidad. Esta nota pretende reconocer algunos resultados anteriores sobre expresiones cerradas para la esperanza de vida de Gompertz y Gompertz-Makeham, en especial en el campo de las ciencias actuariales, con la esperanza de fomentar la interdisciplinariedad y proporcionar el telón de fondo para futuros desarrollos, sobre todo desde que la derivación de expresiones cerradas para la esperanza de vida (y anualidades) basado en leyes de mortalidad despertó el interés de varias áreas, como las ciencias actuariales, biología, demografía, estadística, entre otras.

The Gudermannian Growth Model: Theory, Application and Statistical Analysis

Abstract: Processes producing sigmoid curves are common in many areas such as biology, agrarian sciences, demography and engineering. Several mathematical functions have been proposed for modeling sigmoid curves. Some models such as the logistic, Gompertz, Richards and Weibull are widely used. This work introduces the Gudermannian function as an option for modeling sigmoid growth curves. The original function was transformed and the resulting equation was called the "Gudermannian growth model." This model was applied to four sets of experimental growth data to illustrate its practical application. The results were compared with those obtained by the logistic and Gompertz models. Since all these models are nonlinear in the parameters, the statistical properties of the least squares estimators were evaluated using measures of nonlinearity. For each experimental data set, the Akaike's corrected information criterion was utilized to discriminate among the models. In general, the Gudermannian model fitted better to the experimental data than the logistic and Gompertz models. The results showed that the Gudermannian model can be a good alternative to the classical sigmoid models.

Comparative growth and performance of two generations of tilapia (Oreochromis niloticus)

The growth of generations of the Genomar Supreme Tilapia (GST) strain, specifically G20 and G25, was evaluated. Tilapias 8 g were reared in a recirculating aquaculture system with 0.25 m³ tanks, 80 fish m-³, with four replicates. During growth, eight fish from each tank were weighed and measured at day 1, 30, 60, 90, 120, 150, 180 and 210. Survival, weight gain, feed conversion and batch homogeneity were determined. Weight-age data were fit to Gompertz model. In addition, absolute and relative growth rates and weight and age at inflection were determined. Final weight showed 26.7% higher in G25 when compared to G20 (920.05 and 725.87 g, respectively). The feed conversion and homogeneity indexes were better in G25 than G20. The estimate of asymptotic weight was higher in G25 (1202.0 g) when compared to G20 (912.7 g). G20 presented smaller weight (335.76 g), age (108.87 days) and absolute growth rate (4.87 g day-1) when compared with G25 (442.19 g, 113.77 days and 6.41 g day-1). Carcass characteristics were similar, but G25 presented about 25% higher fillet weight than G20. After five years in the GST breeding program, results indicated that a sustained improvement of harvest weight was achieved, as well as 6 to 10% gain in performance by generation.(AU)

Au@Ag Core@Shell Nanoparticles Synthesized with Rumex hymenosepalus as Antimicrobial Agent.

In this work, we used a sequential method of synthesis for gold-silver bimetallic nanoparticles with core@shell structure (Au@AgNPs). Rumex hymenosepalus root extract (Rh), which presents high content in catechins and stilbenes, was used as reductor agent in nanoparticles synthesis. Size distribution obtained by Transmission Electron Microscopy (TEM) gives a mean diameter of 36 ± 11 nm for Au@AgNPs, 24 ± 4 nm for gold nanoparticles (AuNPs), and 13 ± 3 nm for silver nanoparticles (AgNPs). The geometrical shapes of NPs were principally quasi-spherical. The thickness of the silver shell over AuNPs is around 6 nm and covered by active biomolecules onto the surface. Nanoparticles characterization included high angle annular dark field images (HAADF) recorded with a scanning transmission electron microscope (STEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-Ray Diffraction (XRD), UV-Vis Spectroscopy, Zeta Potential, and Dynamic Light Scattering (DLS). Fourier Transform Infrared Spectrometer (FTIR), and X-ray Photoelectron Spectroscopy (XPS) show that nanoparticles are stabilized by extract molecules. A growth kinetics study was performed using the Gompertz model for microorganisms exposed to nanomaterials. The results indicate that AgNPs and Au@AgNPs affect the lag phase and growth rate of Escherichia coli and Candida albicans in a dose-dependent manner, with a better response for Au@AgNPs.

Comparison of an artificial neural network and Gompertz model for predicting the dynamics of deaths from COVID-19 in México.

The present work is focused on modeling and predicting the cumulative number of deaths from COVID-19 in México by comparing an artificial neural network (ANN) with a Gompertz model applying multiple optimization algorithms for the estimation of coefficients and parameters, respectively. For the modeling process, the data published by the daily technical report COVID-19 in Mexico from March 19th to September 30th were used. The data published in the month of October were included to carry out the prediction. The results show a satisfactory comparison between the real data and those obtained by both models with a R2 > 0.999. The Levenberg-Marquardt and BFGS quasi-Newton optimization algorithm were favorable for fitting the coefficients during learning in the ANN model due to their fast and precision, respectively. On the other hand, the Nelder-Mead simplex algorithm fitted the parameters of the Gompertz model faster by minimizing the sum of squares. Therefore, the ANN model better fits the real data using ten coefficients. However, the Gompertz model using three parameters converges in less computational time. In the prediction, the inverse ANN model was solved by a genetic algorithm obtaining the best precision with a maximum error of 2.22% per day, as opposed to the 5.48% of the Gompertz model with respect to the real data reported from November 1st to 15th. Finally, according to the coefficients and parameters obtained from both models with recent data, a total of 109,724 cumulative deaths for the inverse ANN model and 100,482 cumulative deaths for the Gompertz model were predicted for the end of 2020.

Modeling the Growth and Death of Staphylococcus aureus against Melaleuca armillaris Essential Oil at Different pH Conditions.

Essential oils (EO) are a great antimicrobial resource against bacterial resistance in public health. Math models are useful in describing the growth, survival, and inactivation of microorganisms against antimicrobials. We evaluated the antimicrobial activity of Melaleuca armillaris EO obtained from plants placed in the province of Buenos Aires (Argentina) against Staphylococcus aureus. The minimum inhibitory and bactericidal concentrations were close and decreased, slightly acidifying the medium from pH 7.4 to 6.5 and 5.0. This result was also evidenced by applying a sigmoid model, where the time and EO concentration necessaries to achieve 50% of the maximum effect decreased when the medium was acidified. Moreover, at pH 7.4, applying the Gompertz model, we found that subinhibitory concentrations of EO decreased the growth rate and the maximum population density and increased the latency period concerning the control. Additionally, we established physicochemical parameters for quality control and standardization of M. armillaris EO. Mathematical modeling allowed us to estimate key parameters in the behavior of S. aureus and Melaleuca armillaris EO at different pH. This is interesting in situations where the pH changes are relevant, such as the control of intracellular infections in public health or the development of preservatives for the food industry.

Temporal Progress of Huanglongbing Epidemics and the Effect of Noncommercial Inoculum Sources on Citrus Orchards in São Paulo State, Brazil.

Huanglongbing (HLB) incidence is increasing and threatening citrus production in São Paulo State, Brazil, despite multiple efforts to control the disease and its vector, the Asian citrus psyllid (ACP) (Diaphorina citri). The objective of this research was to study the temporal dynamics of HLB epidemics, under intensive disease management, in 177 individual commercial citrus blocks on a single property in São Paulo State. The effect of internal and external sources of HLB-associated bacteria and its vector were explored based on the disease epidemics and vector dynamics in the studied area. To manage HLB, the property owner used healthy nursery plants, eradicated symptomatic trees, and used insecticides to control ACPs. Logistic and Gompertz models were fitted to the data to describe dynamics of HLB incidence for all blocks. The average number of ACPs per yellow sticky trap was determined for the same blocks for a period of four consecutive years. Both logistic and Gompertz models described the HLB epidemics well, although the Gompertz model provided a slightly better fit. Disease progress rates, HLB incidences, and average ACP count per trap in the 177 blocks were low compared with reports in the literature. HLB incidence and number of ACPs per trap were higher (P ≤ 0.05) in some citrus blocks located on the periphery of the property. A large number of noncommercial trees were found near the property and were a potential primary inoculum source of HLB-associated bacteria, accounting for the higher incidence of HLB and ACPs per trap in blocks located on the periphery of the property. These results support the recommended preventive measures to HLB management and the necessity of external actions, to include trees in commercial orchards, and noncommercial trees located near commercial citrus properties, in an attempt to maximize the effectiveness of these preventive measures.

Prospective production of fructose and single cell protein from date palm waste

BACKGROUND: Fructose and single cell protein are important products for the food market. Abundant amounts of low-grade dates worldwide are annually wasted. In this study, highly concentrated fructose syrups and single cell protein were obtained through selective fermentation of date extracts by Saccharomyces cerevisiae. RESULTS: The effect of air flow (0.1, 0.5, 0.75, 1, 1.25 and 1.5 vvm) and pH (4.5, 4.8, 5, 5.3 and 5.6) was investigated. Higher air flow led to lower fructose yield. The optimum cell mass production of 10 g/L was achieved at air flow of 1.25 vvm with the fructose yield of 91%. Similar cell mass production was obtained in the range pH of 5.0­5.6, while less cell mass was obtained at pH less than 5. Controlling the pH at 4.5, 5.0 and 5.3 failed to improve the production of cell mass which were 5.6, 5.9 and 5.4 g/L respectively; however, better fructose yield was obtained. CONCLUSIONS: Extension of the modified Gompertz enabled excellent predictions of the cell mass, fructose production and fructose fraction. The proposed model was also successfully validated against data from literatures. Thus, the model will be useful for wide application of biological processes.

Modeling and prediction of COVID-19 in Mexico applying mathematical and computational models.

This work presents the modeling and prediction of cases of COVID-19 infection in Mexico through mathematical and computational models using only the confirmed cases provided by the daily technical report COVID-19 MEXICO until May 8th. The mathematical models: Gompertz and Logistic, as well as the computational model: Artificial Neural Network were applied to carry out the modeling of the number of cases of COVID-19 infection from February 27th to May 8th. The results show a good fit between the observed data and those obtained by the Gompertz, Logistic and Artificial Neural Networks models with an R2 of 0.9998, 0.9996, 0.9999, respectively. The same mathematical models and inverse Artificial Neural Network were applied to predict the number of cases of COVID-19 infection from May 9th to 16th in order to analyze tendencies and extrapolate the projection until the end of the epidemic. The Gompertz model predicts a total of 47,576 cases, the Logistic model a total of 42,131 cases, and the inverse artificial neural network model a total of 44,245 as of May 16th. Finally, to predict the total number of COVID-19 infected until the end of the epidemic, the Gompertz, Logistic and inverse Artificial Neural Network model were used, predicting 469,917, 59,470 and 70,714 cases, respectively.

Adjusting the growth curve of sugarcane varieties using nonlinear models / Ajuste da curva de crescimento de variedades de cana-de-açúcar utilizando modelos não lineares

Assessing sugarcane (Saccharum spp.) stalk growth helps to adequately manage the phenological stages of the crop. The aim of this study was to describe the height-growth curve of four sugarcane varieties (RB92579, RB93509, RB931530 and SP79-1011), in irrigated plant-cane and ratoon cane plantations, using the Logistic and Gompertz nonlinear models, while considering all deviations from assumptions. The model parameters were estimated based on the least squares method using the Gauss-Newton algorithm. To select the most suitable model, nonlinear measures, adjusted coefficient of determination (R2 adj), residual standard deviation (RSD), and corrected Akaike information criterion (AICc) were used. Based on the best models, stalk height growth rates and crop phenological stages were determined using critical points. All tests were performed in the free software environment for statistical computing and graphics, R. In general, the Logistic and Gompertz models without AR(1) better described the plant-cane and ratoon cane stalk height, respectively. All varieties showed early growth, and the RB92579 variety presented higher rates in both cycles.(AU)

A avaliação do crescimento dos colmos de cana-de-açúcar (Saccharum spp.) ajuda a adequar o manejo com as fases fenológicas da cultura. Objetivou-se com este trabalho descrever a curva de crescimento da altura de quatro variedades de cana-de-açúcar (RB92579, RB93509, RB931530 e SP79-1011), nos cultivos de cana planta e cana soca irrigados, utilizando os modelos não lineares Logístico e Gompertz, e considerando eventuais desvios de pressupostos. A estimação dos parâmetros dos modelos foi feita com base no método dos mínimos quadrados utilizando o Algoritmo de Gauss-Newton. Para selecionar o modelo mais adequado foram utilizadas as medidas de não linearidade, o coeficiente de determinação ajustado (R2 aj), o desvio padrão residual (DPR) e o critério de informação de Akaike corrigido (AICc). Com base nos melhores modelos foram determinadas as taxas de crescimento da altura dos colmos e as fases fenológicas da cultura por meio dos pontos críticos. Todas as análises foram realizadas no software estatístico R. No geral, os modelos Logístico e Gompertz sem AR(1) descreveram melhor a altura dos colmos em cana planta e cana soca, respectivamente. Todas as variedades apresentaram crescimento precoce, a variedade RB92579 apresentou maiores taxas em ambos os ciclos.(AU)

Nonlinear mixed effects models for comparing growth curves for Guzerá cattle / Modelos não lineares mistos para comparar curvas de crescimento de bovinos da raça Guzerá

The objective of the present work was to evaluate the accuracy of the fitted Gompertz and von Bertalanffy models for male and female Guzerá cattle, respectively. Four production regions in Northeast Brazil were included in the models as a fixed effect, and the animals were included as a random effect. In addition, the coefficients of the growth models in the production regions were compared. The accuracy of the fit equations was assessed with the Akaike information criterion, Bayesian information criterion, mean absolute deviation, mean squared error, and coefficient of determination. Confidence intervals were used for comparing the production regions. The Guzerá males in the Gado-Algodão and Serra Geral da Bahia production regions were statistically equal in asymptotic weight, and the animals in the Itapetinga-Valadares and Mata-Agreste regions had equivalent maturity rates. The Guzerá females in the Itapetinga-Valadares and Serra Geral da Bahia regions had the same asymptotic weight. The maturity rates in Itapetinga-Valadares were equal to those estimated for Mata-Agreste and Serra Geral da Bahia. The inclusion of the fixed effect of the production region and the random effect of the animals in the models improved the fit quality and increased the possibility of generating growth curves for each region.(AU)

O objetivo do presente trabalho foi avaliar a acurácia dos modelos Gompertz e Von Bertalanffy ajustados, respectivamente, para machos e fêmeas da raça Guzerá, sendo incorporado nos modelos o efeito fixo de quatro regiões de produção do nordeste brasileiro e efeito aleatório de animal, além de comparar os coeficientes dos modelos de crescimento entre regiões de produção. A acurácia das equações ajustadas foi avaliada por meio do critério de informação de Akaike, critério de informação Bayesiano, desvio médio absoluto, erro quadrático médio e o coeficiente de determinação. Para comparar as regiões de produção foram utilizados intervalos de confiança. Verificou-se que machos da raça Guzerá das regiões de produção Gado-Algodão e Serra Geral da Bahia possuem peso assintótico estatisticamente igual, enquanto que a taxa de maturidade é equivalente para animais das regiões Itapetinga-Valadares e Mata-Agreste. As fêmeas da raça Guzerá das regiões de Itapetinga-Valadares e Serra Geral da Bahia possuem o mesmo peso assintótico. A taxa de maturidade em Itapetinga-Valadares é igual a estimada para Mata-Agreste e Serra Geral da Bahia. Ao incluir o efeito fixo de região de produção e aleatório de animal nos modelos, houve melhora na qualidade de ajuste e a possibilidade de gerar curvas de crescimento para cada região.(AU)

Nonlinear mixed effects models for comparing growth curves for Guzerá cattle / Modelos não lineares mistos para comparar curvas de crescimento de bovinos da raça Guzerá

The objective of the present work was to evaluate the accuracy of the fitted Gompertz and von Bertalanffy models for male and female Guzerá cattle, respectively. Four production regions in Northeast Brazil were included in the models as a fixed effect, and the animals were included as a random effect. In addition, the coefficients of the growth models in the production regions were compared. The accuracy of the fit equations was assessed with the Akaike information criterion, Bayesian information criterion, mean absolute deviation, mean squared error, and coefficient of determination. Confidence intervals were used for comparing the production regions. The Guzerá males in the Gado-Algodão and Serra Geral da Bahia production regions were statistically equal in asymptotic weight, and the animals in the Itapetinga-Valadares and Mata-Agreste regions had equivalent maturity rates. The Guzerá females in the Itapetinga-Valadares and Serra Geral da Bahia regions had the same asymptotic weight. The maturity rates in Itapetinga-Valadares were equal to those estimated for Mata-Agreste and Serra Geral da Bahia. The inclusion of the fixed effect of the production region and the random effect of the animals in the models improved the fit quality and increased the possibility of generating growth curves for each region.

O objetivo do presente trabalho foi avaliar a acurácia dos modelos Gompertz e Von Bertalanffy ajustados, respectivamente, para machos e fêmeas da raça Guzerá, sendo incorporado nos modelos o efeito fixo de quatro regiões de produção do nordeste brasileiro e efeito aleatório de animal, além de comparar os coeficientes dos modelos de crescimento entre regiões de produção. A acurácia das equações ajustadas foi avaliada por meio do critério de informação de Akaike, critério de informação Bayesiano, desvio médio absoluto, erro quadrático médio e o coeficiente de determinação. Para comparar as regiões de produção foram utilizados intervalos de confiança. Verificou-se que machos da raça Guzerá das regiões de produção Gado-Algodão e Serra Geral da Bahia possuem peso assintótico estatisticamente igual, enquanto que a taxa de maturidade é equivalente para animais das regiões Itapetinga-Valadares e Mata-Agreste. As fêmeas da raça Guzerá das regiões de Itapetinga-Valadares e Serra Geral da Bahia possuem o mesmo peso assintótico. A taxa de maturidade em Itapetinga-Valadares é igual a estimada para Mata-Agreste e Serra Geral da Bahia. Ao incluir o efeito fixo de região de produção e aleatório de animal nos modelos, houve melhora na qualidade de ajuste e a possibilidade de gerar curvas de crescimento para cada região.

Anaerobic co-digestion of industrial landfill leachate and glycerin: methanogenic potential, organic matter removal and process optimization.

The objective of this study was to evaluate the performance of the anaerobic co-digestion of different concentrations of industrial landfill leachate associated with crude residual glycerin, in relation to the methanogenic potential, COD removal, accumulated methane production, the effects of the factors (food/microorganism ratio and percentage of glycerin added to the leachate) and their interactions on kinetic parameters of methane production (CH4) using the modified Gompertz model. Co-digestion tests were carried out in bench scale (400 mL of useful volume) under batch mode at 30 ± 1°C during 30-day incubation of anaerobic sewage sludge as inoculum. The parameters glycerin addition to the leachate (v/v) (0%, 1.5%, 5%, 8.5% and 10%) and F/M ratio (0.3, 0.5, 1, 1.5 and 1.7) were investigated using Central Composite Rotational Design method (CCRD). The results indicated significant effect to the response variables: methanogenic potential, COD removal, accumulated production of CH4 and maximum estimated production of CH4, considering a confidence interval of 95% (p < .05). The ideal mixture of 95.13% of leachate with 4.87% of raw glycerin was obtained by desirability test to F/M of 1.61 gCOD of substrate per gVSS (volatile suspended solids) of sludge. Methanogenic potential was 0.19 LNCH4 gTVSrem -1, and the average removal of COD was 92%, resulting in accumulated production and maximum estimated production of CH4 of 74 and 80 mL, respectively. It was noted that the process of co-digestion of the industrial landfill leachate with the crude residual glycerin is promising, due to is potential of complementing and balancing organic materials, nutrients and other components that influence the biological process. Abbreviations: AN: ammoniacal nitrogen; BMP: biochemical methane potential; CCRD: central composite rotational design; COD: chemical oxygen demand; F/M ratio: food/microorganism ratio; FSS: fixed suspended solids; NTP: normal temperature and pressure; TSS: total suspended solids; TA: total alkalinity; TFS: total fixed solids; TKN: total Kjeldahl nitrogen; TP: total phosphorus; TS: total solids; TVA: total volatile acids; TVS: total volatile solids; VSS: volatile suspended solids; WWTP: wastewater treatment plant.

Growth curve of pacu and the patinga hybrid farmed in a semi-intensive system / Curva de crescimento do pacu e do híbrido patinga produzidos em sistema semi-intensivo

The growth curve is a tool that can be used to determine the performance potential of fish at different ages. The aim of this study was to evaluate the growth curve of pacu (P. mesopotamicus) and the patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in a semi-intensive system. In the initial phase of the experiment, the pacu and patinga fish weighed 32.6 ± 7.5 g and 24.9 ± 7.1 g, respectively. The Gompertz model was adopted to describe the growth curve. At the end of the experiment, body weight, standard length, head length, body height and body width did not differ significantly between the pacu (625.9 g; 25.6 cm; 7.2 cm; 12.1 cm; 4.5 cm) and the patinga hybrid (727.1 g; 27.3 cm; 7.6 cm; 13.2 cm; 4.9 cm). The asymptotic value (parameter A), relative growth rate (parameter B), and age at the inflection point (parameter C) of the growth curve of the two species were similar for weight and for the evaluated morphometric traits. The asymptotic values obtained for weight in the pacu and the patinga hybrid were 1212.0 g and 1348.0 g, respectively. The growth curve of the patinga hybrid is similar to that of pacu, contrasting with the belief of many fish farmers.(AU)

A curva de crescimento possibilita determinar o potencial de desempenho dos peixes em diferentes idades. O objetivo do estudo foi avaliar a curva de crescimento do pacu (P. mesopotamicus) e do híbrido patinga (P. mesopotamicus x P. brachypomus) produzidos em sistema semi-intensivo. Foram utilizados no início do experimento pacu e patinga com peso de 32,6 ± 7,5 g e 24,9 ± 7,1 g, respectivamente. Foi utilizado o modelo Gompertz para descrever a curva de crescimento. No final do experimento, o peso corporal, comprimento padrão, comprimento da cabeça, altura do corpo e largura do corpo não diferiram significativamente entre o pacu (625,9 g; 25,6 cm; 7,2 cm; 12,1 cm; 4,5 cm) e o híbrido patinga (727,1g; 27,3 cm; 7,6 cm; 13,2 cm; 4,9 cm). O valor assintótico (parâmetro A), taxa de crescimento relativo (parâmetro B) e idade no ponto de inflexão (parâmetro C) da curva de crescimento do pacu e patinga foram semelhantes para peso e características morfométricas avaliadas. O valor assintótico obtido para peso no pacu e no híbrido patinga foi de 1212,0 g e 1348,0 g, respectivamente. O híbrido patinga apresenta curva de crescimento semelhante ao pacu, contrastando com a crença de muitos piscicultores.(AU)

Growth curve of pacu and the patinga hybrid farmed in a semi-intensive system / Curva de crescimento do pacu e do híbrido patinga produzidos em sistema semi-intensivo

The growth curve is a tool that can be used to determine the performance potential of fish at different ages. The aim of this study was to evaluate the growth curve of pacu (P. mesopotamicus) and the patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in a semi-intensive system. In the initial phase of the experiment, the pacu and patinga fish weighed 32.6 ± 7.5 g and 24.9 ± 7.1 g, respectively. The Gompertz model was adopted to describe the growth curve. At the end of the experiment, body weight, standard length, head length, body height and body width did not differ significantly between the pacu (625.9 g; 25.6 cm; 7.2 cm; 12.1 cm; 4.5 cm) and the patinga hybrid (727.1 g; 27.3 cm; 7.6 cm; 13.2 cm; 4.9 cm). The asymptotic value (parameter A), relative growth rate (parameter B), and age at the inflection point (parameter C) of the growth curve of the two species were similar for weight and for the evaluated morphometric traits. The asymptotic values obtained for weight in the pacu and the patinga hybrid were 1212.0 g and 1348.0 g, respectively. The growth curve of the patinga hybrid is similar to that of pacu, contrasting with the belief of many fish farmers.

A curva de crescimento possibilita determinar o potencial de desempenho dos peixes em diferentes idades. O objetivo do estudo foi avaliar a curva de crescimento do pacu (P. mesopotamicus) e do híbrido patinga (P. mesopotamicus x P. brachypomus) produzidos em sistema semi-intensivo. Foram utilizados no início do experimento pacu e patinga com peso de 32,6 ± 7,5 g e 24,9 ± 7,1 g, respectivamente. Foi utilizado o modelo Gompertz para descrever a curva de crescimento. No final do experimento, o peso corporal, comprimento padrão, comprimento da cabeça, altura do corpo e largura do corpo não diferiram significativamente entre o pacu (625,9 g; 25,6 cm; 7,2 cm; 12,1 cm; 4,5 cm) e o híbrido patinga (727,1g; 27,3 cm; 7,6 cm; 13,2 cm; 4,9 cm). O valor assintótico (parâmetro A), taxa de crescimento relativo (parâmetro B) e idade no ponto de inflexão (parâmetro C) da curva de crescimento do pacu e patinga foram semelhantes para peso e características morfométricas avaliadas. O valor assintótico obtido para peso no pacu e no híbrido patinga foi de 1212,0 g e 1348,0 g, respectivamente. O híbrido patinga apresenta curva de crescimento semelhante ao pacu, contrastando com a crença de muitos piscicultores.

Adjusting the growth curve of sugarcane varieties using nonlinear models / Ajuste da curva de crescimento de variedades de cana-de-açúcar utilizando modelos não lineares

ABSTRACT: Assessing sugarcane (Saccharum spp.) stalk growth helps to adequately manage the phenological stages of the crop. The aim of this study was to describe the height-growth curve of four sugarcane varieties (RB92579, RB93509, RB931530 and SP79-1011), in irrigated plant-cane and ratoon cane plantations, using the Logistic and Gompertz nonlinear models, while considering all deviations from assumptions. The model parameters were estimated based on the least squares method using the Gauss-Newton algorithm. To select the most suitable model, nonlinear measures, adjusted coefficient of determination (R2 adj), residual standard deviation (RSD), and corrected Akaike information criterion (AICc) were used. Based on the best models, stalk height growth rates and crop phenological stages were determined using critical points. All tests were performed in the free software environment for statistical computing and graphics, R. In general, the Logistic and Gompertz models without AR(1) better described the plant-cane and ratoon cane stalk height, respectively. All varieties showed early growth, and the RB92579 variety presented higher rates in both cycles.

RESUMO: A avaliação do crescimento dos colmos de cana-de-açúcar (Saccharum spp.) ajuda a adequar o manejo com as fases fenológicas da cultura. Objetivou-se com este trabalho descrever a curva de crescimento da altura de quatro variedades de cana-de-açúcar (RB92579, RB93509, RB931530 e SP79-1011), nos cultivos de cana planta e cana soca irrigados, utilizando os modelos não lineares Logístico e Gompertz, e considerando eventuais desvios de pressupostos. A estimação dos parâmetros dos modelos foi feita com base no método dos mínimos quadrados utilizando o Algoritmo de Gauss-Newton. Para selecionar o modelo mais adequado foram utilizadas as medidas de não linearidade, o coeficiente de determinação ajustado (R2 aj), o desvio padrão residual (DPR) e o critério de informação de Akaike corrigido (AICc). Com base nos melhores modelos foram determinadas as taxas de crescimento da altura dos colmos e as fases fenológicas da cultura por meio dos pontos críticos. Todas as análises foram realizadas no software estatístico R. No geral, os modelos Logístico e Gompertz sem AR(1) descreveram melhor a altura dos colmos em cana planta e cana soca, respectivamente. Todas as variedades apresentaram crescimento precoce, a variedade RB92579 apresentou maiores taxas em ambos os ciclos.

Effect of process parameters on enhanced biohydrogen production from tequila vinasse via the lactate-acetate pathway.

In this study, a lactate-type fermentation entailing the consumption of lactate and acetate (lactate-acetate pathway) is proposed to deal with lactic acid bacteria (LAB) inhibition during the production of biohydrogen (bioH2) from tequila vinasse. The effects of total solids content, substrate concentration, nutrient formulation and inoculum addition on bioH2 production performance were investigated. Batch experiments were performed in a 3-L completely mixed reactor at 35 °C and pH 6.5-5.8. The lactate-acetate pathway mediated consistent bioH2 production which was influenced by inoculum addition followed by substrate concentration, nutrient formulation and solids content. Maximum bioH2 production rate (225 NmL/L-h) and yield (124 NmL/g VSadded) were achieved by removing suspended solids and enhancing nutrient content, respectively. Illumina sequencing-based analysis revealed a dominance of Clostridium in the inoculum, which together with LAB and acetic acid bacteria shaped a keystone cluster for avoiding LAB inhibition while ensuring consistent bioH2 production performance.