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.

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The inhibition of copper nanoparticles produced in a nec_BES to plant pathogens was investigated in this study.

The synthesis of CdS nanoparticles was developed based on the unconventional design of bioelectrochemical system (BES) inoculated with Shewanella sp. HN-41. The BES configuration included two bottle chambers separated by silicon membrane but directly connected by a graphite electrode perforating through silicon membrane, namely, non-external circuit bioelectrochemical system (nec_BES). Shewanella sp. HN-41 in the anode of nec_BES consumed lactate and transferred electrons to the graphite electrode end in the anode and, in its turn, the graphite electrode end in the cathode reduced directly thiosulfate to sulphide, forming CdS nanoparticles after 21 days. CdS nanoparticles with the average size of approximately 17 nm were synthesized in the cathode solution. The hollow, spherical, and void structure of particles was observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images. The energy dispersive X-ray spectroscopy (EDS) study confirmed the nanoparticles contained Cd and S elements, and X-ray diffraction (XRD) data showed a strong crystalline phase and mixed crystallites of CdS nanoparticles. The UV-Vis absorption spectra of CdS nanoparticles revealed the blue shift in excitonic transition with respect to CdS bulk material, suggesting its potential application in optical studies. The bioelectrochemical system can be applied for the removal and preparation of other sulphide heavy metals.

Avocado is a significant cash crop in Vietnam, while little is known about its genetic diversification. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were performed to investigate the genetic diversity of twenty-eight imported and domestic avocado cultivars being maintained at Western Highlands Agriculture and Forestry Science Institute, Dak Lak, Vietnam. 18 RAPD and 15 ISSR primers produced 3183 and 2807 scorable bands, of which 83.92% and 71.72% were polymorphic, respectively. The RAPD markers exhibited an average PIC of 0.27 and Rp index of 12.63 whereas the mean PIC and Rp values of ISSR primers were 0.21 and 13.37, respectively. The correlation between RAPD and ISSR markers was low (r = 0.338), suggesting that the ability to resolve genetic variation among varieties may relate to the number of detected polymorphisms rather than the marker employed. Nevertheless, the correlation between ISSR and combined data was high (r = 0.791) and the correlation between RAPD and combined matrices was even higher (r = 0.897). This indicates that RAPD markers have slightly higher efficiency over ISSR to resolve genetic variation among 28 avocado cultivars. High genetic diversity among 28 avocado cultivars was revealed with the Jaccard’s similarity coefficient ranging from 0.623 to 0.913 based on combined data analysis. The UPGMA dendrogram generated from combined RAPD and ISSR data grouped Vietnamese domestic and imported avocado cultivars into three different groups at 72% similarity. These results could be applied to the avocado conservation and breeding programs