Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike’s information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Mathematical models to describe the growth curves of Vietnamese Ri chicken

Abstract Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaikes information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights () were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Resumo O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos () foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Mathematical models to describe the growth curves of Vietnamese Ri chicken / Modelos matemáticos para descrever as curvas de crescimento do frango Ri vietnamita

Abstract Ri chicken is the most popular backyard chicken breed in Vietnam, but little is known about the growth curve of this breed. This study compared the performances of models with three parameters (Gompertz, Brody, and Logistic) and models containing four parameters (Richards, Bridges, and Janoschek) for describing the growth of Ri chicken. The bodyweight of Ri chicken was recorded weekly from week 1 to week 19. Growth models were fitted using minpack.lm package in R software and Akaike's information criterion (AIC), Bayesian information criterion (BIC), and root mean square error (RMSE) were used for model comparison. Based on these criteria, the models having four parameters showed better performance than the ones with three parameters, and the Richards model was the best one for males and females. The lowest and highest value of asymmetric weights (α) were obtained by Bridges and Brody models for each of sexes, respectively. Age and weight estimated by the Richard model were 8.46 and 7.51 weeks and 696.88 and 487.58 g for males and for females, respectively. Differences in the growth curves were observed between males and female chicken. Overall, the results suggested using the Richards model for describing the growth curve of Ri chickens. Further studies on the genetics and genomics of the obtained growth parameters are required before using them for the genetic improvement of Ri chickens.

Resumo O frango Ri é a raça de frango de quintal mais popular do Vietnã, mas pouco se sabe sobre a curva de crescimento dessa raça. Este estudo comparou o desempenho de modelos com três parâmetros (Gompertz, Brody e Logistic) e modelos contendo quatro parâmetros (Richards, Bridges e Janoschek) para descrever o crescimento do frango Ri. O peso corporal do frango Ri foi registrado semanalmente da semana 1 à semana 19. Os modelos de crescimento foram ajustados usando o pacote minpack.lm no software R e o critério de informação de Akaike (AIC); critério de informação bayesiano (BIC) e erro quadrático médio (RMSE) foram usados ​​para comparação de modelos. Com base nesses critérios, os modelos com quatro parâmetros apresentaram melhor desempenho do que os com três parâmetros, sendo o modelo de Richards o melhor para homens e mulheres. O menor e o maior valor dos pesos assimétricos (α) foram obtidos pelos modelos Bridges e Brody para cada um dos sexos, respectivamente. A idade e o peso estimados pelo modelo de Richard foram de 8,46 e 7,51 semanas e 696,88 e 487,58 g para homens e mulheres, respectivamente. Diferenças nas curvas de crescimento foram observadas entre frangos machos e fêmeas. No geral, os resultados sugeriram o uso do modelo de Richards para descrever a curva de crescimento de frangos Ri. Mais estudos sobre a genética e genômica dos parâmetros de crescimento obtidos são necessários antes de usá-los para o melhoramento genético de frangos Ri.

Antibiofilm activity of alpha-mangostin loaded nanoparticles against Streptococcus mutans

Objective: To investigate the antibiofilm activity of alpha-mangostin (AMG) loaded nanoparticle (nanoAMG) against dental caries pathogen Streptococcus mutans. Methods: AMG was isolated from the peels of Garcinia mangostana L. using silica gel columns and chemically analysed by high performance liquid chromatography and nuclear magnetic resonance. NanoAMG was prepared using the solvent evaporation method combined with high-speed homogenization. The nanoparticles were characterized using dynamic light scattering, field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). The toxicity of nanoAMG in fibroblast NIH/3T3 cell line was determined using MTT method. The antibiofilm effect of nanoAMG was determined through the evaluation of biofilm formation by Streptococcus mutans using a 96-well plate. Biofilm biomass was quantified using crystal violet. Cell viability was observed under confocal microscopy using LIVE/DEAD BacLight staining. Moreover, gene expression was determined by quantitative real-time PCR and membrane permeabilization activity by measuring the uptake of o-nitrophenol-β-D-galactoside. Results: NanoAMG size was in a range of 10-50 nm with a polydispersity index of < 0.3 and zeta potential value of -35.2 mV. The size and the incorporation of AMG in the nanoparticles were confirmed by FE-SEM and FTIR analyses. The IC50 values of the test agents on NIH/3T3 cells were (9.80 ± 0.63) μg/mL for AMG and (8.70 ± 0.81) μg/mL for nanoAMG, while no toxicity was generated from excipients used to prepare nanoparticles. In the early stage of biofilm formation, treatment with 6.25 μmol/L nanoAMG caused a reduction in biofilm biomass up to 49.1％, compared to 33.4％ for AMG. In contrast, biofilms at the late stage were more resistant to the test agents. At 96 μmol/L (= 10 × MIC), nanoAMG reduced only 20.7％ of biofilm biomass while AMG did not show any effect. Expressions of gtfB and gtfC genes involved in biofilm formation were down-regulated 3.3 and 12.5 folds, respectively, compared to AMG (2.4 and 7.6 folds, respectively). LIVE/DEAD BacLight fluorescence staining and microscopy observation indicated that biofilm cells were killed by both nanoAMG andAMG at 48 μmol/L (= 5 × MIC). In addition, membrane permeabilization activity was increased in a time dependent manner and higher in nanoAMG treated cells compared toAMG.Conclusions: AMG coated nanoparticle can enhance AMG bioactivity and can be used as a new and promising antibiofilm agent.

Species composition and level of infestation of cockroaches in three areas in Hanoi

A study on the species composition and the level of infestation of cockroaches was carried out from April 2013 to October 2014 in three localities of Hanoi, Vietnam, namely the Lan Ong-Old Town, Linh Dam condominium and Tan Da Resort. Out of the 187 units of premises examined, 44.9% of units were infested with cockroaches. A total of 576 cockroaches were trapped, of which six species were identified: Periplaneta americana (L.) was the most dominant species (72.1%), followed by Blattella germanica (L.) (14.8%), Pycnoscelus surinamensis (L.) (7.3%), Periplaneta australasiae (Fabricius) (2.9%), Periplaneta fuliginosa (Serville) (1.9%) and Supella longipalpa (Fabricius) (1.0%). Infestation was the highest in Lan Ong (74.0%), followed by Linh Dam (40.5%) and Tan Da (25.9%). Cockroaches were abundantly found in warehouses (100%), electrical distribution room (56.3%), and kitchens (46.7%).

Impact of prenatal care on perinatal mortality.

This study aimed to estimate the perinatal mortality rate (PMR) in Ho Chi Minh City, Vietnam, and to assess the association between perinatal death (PD) and prenatal care (PC). During January 1st to December 31st, 1992, among 4,809 births ascertained from 22 communes randomly selected in two areas, urban and rural, of Ho Chi Minh City, 48 still births and 66 early neonatal deaths were recorded, resulting in a weighted PMR of 25 (95% confidence interval: 20-29) per thousand. Major causes of PD were prematurity 33%, congenital malformation 15%, perinatal asphyxia 12%, perinatal infection 11%, birth injury 4%, others 8% and unknown 16%. From the whole sample, a nested case-control study was conducted on 103 cases (all the mothers whose infants died) and 309 controls (selected among the mothers of surviving infants) to assess the relationship between PD and prenatal care (PC). During unconditional logistic regression, starting prenatal care (PC) within the 1st trimester was associated with a lower risk of PD, giving an odds ratio of 0.11 (95% CI: 0.02-0.61), whereas having 4 to 8 visits gave an odds ration of 0.15 (95% CI: 0.03-0.67). It is concluded that early onset of prenatal care and having four to eight visits provide significant protection against perinatal mortality.