Background: The tiger frog (Hoplobatrachus rugulosus) is widely raised by many farms in southern region of China as an economically edible frog. The growth, development, and sexual differentiation of amphibians are influenced by temperature and steroid hormone level. However, the problem of hormone residues is caused by the addition of exogenous hormones in frog breeding, it is worth considering whether non-sterol aromatase inhibitors can be used instead of hormones.Methods: In our study,H. rugulosustadpoles were subjected to two water temperatures (29 °C and 34 °C) and three letrozole concentrations in the feed (0, 0.1 and 1 mg/g) to examine the effects of temperature, aromatase inhibitor and their interaction on metamorphosis, locomotion, and sex ratios. AG-test and contingency table were used to analyze the metamorphosis rate of tadpoles and the survival rate of froglets after feeding for 90 days. AG-test was also used to analyze sex ratios in different treatment groups.Results: Metamorphosis time and body size (snout–vent length, body mass and condition factor) were significantly different between the two temperature treatments. Metamorphosis time was longer and body size was increased at 29 °C compared to those at 34 °C. Letrozole concentration and the temperature × letrozole interaction did not affect these variables. The jumping distance of froglets following metamorphosis was positively associated with the condition factor; when controlling for condition factor, jumping distance was not affected by temperature, letrozole concentration and their interaction. Temperature and letrozole concentration also did not affect metamorphosis and survival rate. Sex ratio of the control group (0 mg/g letrozole) was 1:1 at 29 °C, but there were more males at 34 °C. The sex ratios ofH. rugulosustreated with letrozole at 29 °C and 34 °C were significantly biased toward males, and male ratio increased as letrozole concentration increased. Furthermore, more males were produced at 34 °C than at 29 °C at each letrozole concentration.

Background: The liver-expressed antimicrobial peptide 2 (LEAP2) is essential in host immunity against harmful pathogens and is only known to act as an extracellular modulator to regulate embryonic development in amphibians. However, there is a dearth of information on the antimicrobial function of amphibian LEAP2. Hence, a LEAP2 homologue from Leptobrachium liui was identified, characterized, and chemically synthesized, and its antibacterial activities and mechanisms were determined. Results: In this study, LEAP2 gene (Ll-LEAP2) cDNA was cloned and sequenced from the Chong’an Moustache Toad (Leptobrachium liui). The predicted amino acid sequence of Ll-LEAP2 comprises a signal peptide, a mature peptide, and a prodomain. From sequence analysis, it was revealed that Ll-LEAP2 belongs to the cluster of amphibian LEAP2 and displays high similarity to the Tropical Clawed Frog (Xenopus tropicalis)‘s LEAP2. Our study revealed that LEAP2 protein was found in different tissues, with the highest concentration in the kidney and liver of L. liui; and Ll-LEAP2 mRNA transcripts were expressed in various tissues with the kidney having the highest mRNA expression level. As a result of Aeromonas hydrophila infection, Ll-LEAP2 underwent a noticeable up-regulation in the skin while it was down-regulated in the intestines. The chemically synthesized Ll-LEAP2 mature peptide was selective in its antimicrobial activity against several in vitro bacteria including both gram-positive and negative bacteria. Additionally, Ll-LEAP2 can kill specific bacteria by disrupting bacterial membrane and hydrolyzing bacterial gDNA. Conclusions: This study is the first report on the antibacterial activity and mechanism of amphibian LEAP2. With more to uncover, the immunomodulatory functions and wound-healing activities of Ll-LEAP2 holds great potential for future research.

Given the information age, an important educational objective is cultivating innovators who can propose unique ideas. Learner-centred education is a way to achieve this objective; however, what is the current effectiveness of learner-centred education? A meta-analysis was conducted to analyse 72 effect sizes from 42 quantitative studies to determine the effect of learner-centred education on students’ academic achievement across a 10-year period (2010–2020). The overall effect size was 0.5446 (95% CI [0.3754, 0.7138]), which was medium, positive, and significant (P < 0.001). Thus, learner-centred education can significantly improve students’ academic achievement. There were significant differences (all P < 0.05) in the influence of learner-centred education on academic achievement among six independent variables (subject, region, education phase, learning environment, teaching strategies, and autonomous learning form). Future research should focus on the positive impact of learner-centred education and choosing teaching strategies and learning forms to the discipline to promote it.

Non-academic achievement refers to the positive learning quality, personality, and social adaptability students develop during the learning process, which is essential for growth and social development. Can popular student-centered education assume the responsibility of cultivating learners with excellent learning qualities and extraordinary social competencies, as expected by educators globally? Using a meta-analysis, we reviewed and summarized 65 effect sizes from 31 quantitative research papers on the impact of student-centered education on students’ non-academic achievements, published from January 2010 to April 2021. The results showed that student-centered education had a positive impact on students’ non-academic achievements. The impact was greatest at the secondary and higher education levels and over a 3-month experimental period; however, no significant differences were found in curricula, teaching models, teaching strategies, or learning forms. Our results confirm that student-centered education should be widely adopted and accepted in the long term, at secondary and higher education levels.