Raw materials of corn stalk and Japanese watercress at four volumetric ratios of 4:1, 3:1, 2:1, 1:2 were composted for 40 days using compost (PP compost) and bokashi (PP bokashi) methods. The quality of organic fertilizer products as solid (RComp) and liquid (LComp & LBoka) was analyzed for physico-chemical properties and initially evaluated for spinach (Spinacia oleracea L.) in a pot study. The single-factor experiment was arranged in a completely randomized design with seven treatments and three replications. The treatments differed in application rates, types and dilution ofliquid organic fertilizers. The PP compost had a thermophilic phase (t > 40oC) lasting for 15 days, which was three times longer than the PP bokashi. Accordingly, RComp(2:1) had a high EC (electrical conductivity) value (3.8 mS/cm) and organic matter (77.7%), and macronutrient concentrations of total N, available phosphorus and potassium were 26.3 g/kg, 13.6 g P2O5/kg and 63.0 g K2O/kg, respectively. Total aerobic plate counts in LComp(2:1) reached 2.5 × 107 CFU/mL. Meanwhile, L Boka(1:2) had an EC value of 19.8 mS/cm, and nutrient concentrations of total N, available phosphorus and potassium were 0.35 g N/kg, 0.09 g P2O5/kg and 9.93 g K2O/kg, respectively. Total humic and fulvic acids in LBoka(1:2) reached 2,300 mg/kg. The results of the trial rate of 0.5 kg RComp/m2 as a single or combined application with LComp(2:1) and LBoka(1:2) at diluted concentrations of total dissolved solids (TDS) 500 ppm gave a similar performance of plant heights, number of leaves, and yields of 1,278.9 - 1,425.7 g/m2, and were significantly different from those of the control treatment (526.8 g/m2).

This study aimed to evaluate some major physical and mechanical properties of 7 year old Acacia hybrid BV10 planted in Quy Chau district, Nghe An province. Small specimens with dimensions of 20 (Radial) × 20 (Tangential) × 320 (Longitudinal) mm3 were cut near the pith and near the bark at breast height from each sample tree, then placed in a standard laboratory setting until their weightsreached a constant value. The resulting mean air-dry density (AD), stress wave velocity (SWV), static modulus of elasticity (MOE) and modulus of rupture (MOR) were 0.53 g/cm3, 4,241 m/s, 10.00 GPa, and 82.17 MPa, respectively. Statistical analysis showed that SWV and these wood properties examined near the bark were always higher than those values measured near the pith. Stress wave technology can be used to predict MOE and MOR; however, AD is still a more reliable indicator for predicting mechanical properties since it showed a strong correlation with MOE (r = 0.86; P < 0.001) and MOR (r = 0.80; P < 0.001).

 The objective of this study was to analyze the variation in timber production in Acacia hybrid plantations based on age and different sites. Data were collected from 50 standard plots (25 × 20 m) of different plantation ages ranging from 2 to 10 years. The site condition of Acacia hybrid plantations were assessed using 5 site indices from I to V. Site index functions were developed from the height of 50 dominant trees at the age of 10. Production functions at the average tree level were constructed using data from 50 trees at age 10. The research results showed that 5 site indices of Acacia hybrid plantations had values of 28, 25, 22, 19 & 16 m, respectively. Timber production of Acacia hybrid plantations has changed markedly with age and site indices. The age of 2 could be the time when diameter and height of Acacia hybrid plantations change from the fast growing stage to the slow growing stage. By the age of 5, the timber volume of Acacia hybrid plantations changes from the fast growing stage to the slow growing stage. The average timber productivity of 10 year old Acacia hybrid plantations on 5 site indices from I đến V was 38.8, 28.6, 20.2, 13.6, & 8.5 m3/ha per year, respectively. The age of quantitative maturity of Acacia hybrid plantations on 5 site indices was 9 years of age.

The study was carried out to determine the suitable stocking densities and harvesting methods, and to evaluate the economic efficiency of Artemia biomass culturing in tarpaulin tanks in Ho Chi Minh City. The experiment consisted of 8 treatments arranged in a completely randomized block design with 3 replicates of 2 stocking densities (M1: 1,500 & M2: 2,000 individuals/L) and 4 harvesting frequencies (T1: 1 day/time - 10%, T3: 3 days/time - 30%, T5: 5 days/time - 50% and T14: 14 days collecting 100% amount of Artemia biomass in the tank). The study results showed that the average size of males and females ranged from 9.12 - 9.55 mm and 9.84 - 11.01 mm, respectively. At day 14, the survival rate at a density of 1,500 individuals/L accounted for 63.68 ± 2.50% which was statistically significant (P < 0.05) compared to the density of 2,000 individuals/L (60.95 ± 1.39%). The mean fecundity of female Artemia ranged from 70 to 72 embryos/female and tended to increase gradually from 92 to 101 embryos/female. The harvesting frequency affected Artemia population composition, density and biomass yield. After 29 days, the T3M1 treatment yielded the highest biomass (3.33 ± 0.39 kg/m3) and the most optimal profit with 225.53 ± 9.08 thousand VND/kg. The treatment DCM2 gave the lowest yield (1,22 ± 0.27 kg/m3) with a profit of 78.04 ± 58.58 thousand VND/kg.

Post-weaning diarrhea is one of the most common diseases in pigs, affecting pigs in the first two weeks after weaning, causing significant economic losses. The main cause of this disease is Enterotoxigenic Escherichia coli (ETEC), which is characterized by two pathogenic factors: fimbriae and enterotoxins. These fimbriae are considered to mediate bacterial adhesion through binding to the receptor present in the pig intestine. Several studies indicate that F4 and F18 fimbriae account for a high percentage of the fimbriae in ETEC and are detected in most of the isolated ETEC strains. Currently, oral vaccines are a potential preventive measure used with the ability to generate IgA, stimulate the mucosal immune system, and be widely noticed by researchers. However, the vaccines are only effective against ETEC-F4 and less effective against ETEC-F18, so more research is needed to improve the effectiveness of ETEC-F18 vaccines in the future. In this review, we presented the structure, function, and potential application of the F18 in vaccine development.

Microalgae have currently been considered as a promising feedstock for biodiesel production. The accumulation of microalgal lipids is species-specific and largely dependent upon cultivation conditions. The present study aimed to investigate the biomass productivity and lipid content of Scenedesmus obliquus cultivated under nitrogen (N)- and phosphorus (P)-depleted conditions. The highest microalgal density was 38.0 ± 3.5 × 106 cell/mL after 12 days of cultivation in the standard Bold’s Basal Medium (BBM) and significantly decreased with decreasing N conentrations in the media, with the density of 1.4 ± 0.5 ×106, 21.5 ± 1.4 × 106, 25.7 ± 4.9 × 106, and 33.5 ± 1.2 × 106 cell/mL in the nutrient solutions containing 0, 25, 50, and 75% N, respectively. Conversely, the P concentrations showed negligible effects on the growth of S. obliquus across all treatments. Overall, the lipid accumulation of S. obliquus increased with decreasing N and P concentrations. The results revealed that N-starvation yielded the highest microalgal lipid content of 184.1 ± 17.4 mg/g d.w., whereas that under N-sufficient condition was only 80.0 ± 9.8 mg/g d.w. Likewise, the lipid content was almost double when S. obliquus was grown in the modified BBM containing half of P concentration of the standard medium. Taken together, this study demonstrates that alteration of the nutrients is an effective approach for enhancing lipid accumulation in S. obliquus.