Large-Scale Application of Double-Stranded RNA Shows Potential for Reduction of Sacbrood Virus Disease in Apis cerana Apiaries.

Sacbrood virus (SBV) infection has emerged as a remarkable threat to Apis cerana colonies in South Korea, necessitating prompt control measures. In this study, RNA interference (RNAi) targeting the VP3 gene was developed to assess its safety and efficacy in protecting and treating SBV in vitro and in infected colonies in South Korean apiaries. The efficacy of VP3 double-stranded RNA (dsRNA) was demonstrated in laboratory-based experiments, wherein infected larvae treated with VP3 dsRNA exhibited a 32.7% increase in survival rate compared to untreated larvae. Data from a large-scale field trial indicate the efficacy of dsRNA treatment since none of the treated colonies had symptomatic SBV infections, whereas disease was observed in 43% (3/7) of the control colonies. In the 102 colonies exhibiting symptoms of SBV disease, RNAi treatment provided partial protection with weekly treatment, prolonging the survival period of colonies to 8 months compared to 2 months in colonies treated at 2- and 4-week intervals. Therefore, this study demonstrated that RNAi is a valuable tool for preventing SBV disease outbreaks in healthy and low-level SBV-infected colonies.

Role of L2 Motivational Self System on Willingness to Communicate of Korean EFL University and Secondary Students.

This study investigated the role of the L2 motivational self system on L2 willingness to communicate (L2 WTC) by Korean EFL university and secondary students. Drawing on a purposive sampling technique and an explanatory sequential mixed methods design, quantitative data (105 university and 112 high school students) were first collected and analyzed. Then, qualitative data (one focus group discussion with nine participants and five in-depth individual interviews) were collected and analyzed to further explain quantitative findings. Results showed that high school students, who exhibited stronger ideal L2 self and ought-to L2 self, had a higher level of L2 WTC inside and outside the classroom. In contrast, university students, who exhibited a stronger sense of ideal L2 self, had a higher level of L2 WTC in both communicative settings. While high-stakes English tests still seem to shape EFL secondary students' motivational mindset (ought-to L2 self), this study also suggests that pedagogical supports, such as offering performance-based English tasks, cultivating one's ideal L2 self image, and encouraging production-oriented English activities in out-of-class digital environments, could enhance contemporary students' L2 WTC in test-oriented EFL countries.

Influence of emulsifier blends having different hydrophilic-lipophilic balance value on growth performance, nutrient digestibility, serum lipid profiles, and meat quality of broilers.

Energy is a major cost component in diets for poultry. We hypothesized that the supplementation of emulsifier blends in broiler diets may contribute to the efficient utilization of energy and in increasing fat digestibility, thereby improving performance. To test our hypothesis, an experiment was conducted to evaluate the effect of a blend of emulsifiers on growth performance, nutrient digestibility, serum lipid profiles, and meat quality of broilers. A total of 768 1-d-old Ross 308 male broiler chicks with an average initial body weight of 45.55 ± 0.34 g were used in a 35 days feeding trial. Broilers were sorted into 4 treatments, 12 replications per treatment, and 16 birds per pen. Dietary treatments consisted of corn-soybean meal based basal diet and the basal diet supplemented with 0.05%, 0.075%, and 0.10% emulsifier. As a result of this study, the inclusion of 0.05%, 0.075%, and 0.10% emulsifier blends (sodium stearoyl-2-lactylate (SSL) and Tween 20) in the basal diet linearly increased (P = 0.0001) body weight gain (BWG) and improved feed conversion ratio (FCR) (linear effect P = 0.0001) on d 7 to 21, d 21 to 35 as well as overall. Broilers fed with different levels of emulsifier blends also showed a linear increment (P < 0.05) in dry matter (DM) and fat digestibility. A trend of linear reduction (P = 0.051) in low density lipoprotein (LDL) in the serum of broilers fed emulsifier blend was observed. The lightness value of breast muscle color linearly increased (P = 0.001), the redness and yellowness values tended to increase (P = 0.072 and P = 0.094 respectively), and the water holding capacity (WHC) showed trends in reduction (P = 0.078) with an increase in the level of emulsifier blends. With regards to relative organ weight, spleen weight was linearly (P = 0.001) reduced with the increase in the supplemental levels of emulsifier blends. A positive correlation between emulsifier content in the diet and BWG, DM and fat digestibility, and breast muscle color indices, were also observed. In conclusion, emulsifier blend supplementation positively influenced growth performance and nutrient digestibility in broiler chickens.