Yulin University

Taking the course "Fundamentals of Tourism Guiding" as the carrier, based on the development trend of cultural and tourism integration, this study constructs a construction framework of ideological and political demonstration course featuring "value guidance - content integration - practice empowerment - evaluation closed-loop". By excavating ideological and political elements from Northern Shaanxi's red culture, traditional culture, and ecological resources, core literacy such as national awareness, cultural confidence, professional ethics, and ecological responsibility are integrated into the entire teaching process. An implementation path of "five-minute ideological and political introduction before class, ideological and political penetration through in-class cases, and ideological and political tempering through after-class practice" is innovated. Empirical study shows that this construction mode has effectively realized the trinity educational goal of "knowledge impartment, ability training, and value shaping". Students' cultural confidence, professional identity, and social responsibility have been significantly improved, providing a replicable and promotable practical paradigm for the ideological and political construction of similar courses.

Amylase, an enzyme with significant industrial applications, can be produced sustainably and economically using agricultural waste. This study investigates amylase production from Bacillus species utilizing potato peel substrates, aiming to achieve both environmental and economic benefits. Bacterial strains capable of producing amylase were isolated and characterized. Using response surface methodology, key variables, substrate concentration, pH, and temperature, were optimized to enhance enzymatic activity. The effects of acidic and alkaline pretreatments on potato peel substrates were also assessed. Amylase was purified through dialysis and salting out and analyzed using sodium dodecyl sulfate-polyacrylamide electrophoresis (SDS-PAGE). Enzyme immobilization in calcium alginate beads was performed to evaluate stability for industrial reuse. Optimal production was achieved at a substrate concentration of 17.4%, pH 10.8, and temperature 54.2°C, with alkaline pretreatment significantly improving yield. Purification increased enzyme concentration and purity, confirmed by the presence of a distinct 55kDa band in SDS-PAGE. Immobilization enhanced enzyme stability, indicating potential for repeated industrial applications. These findings highlight the viability of producing amylase from agricultural waste while reducing costs and environmental impact. The results also emphasize the value of substrate pretreatment and enzyme immobilization in developing efficient and sustainable biotechnological processes.

This study aimed to evaluate the efficacy of estrus synchronization protocols in goats and to identify the most cost-effective regimen for intensive farming. The protocols assessed used progesterone (P4) sponges or controlled internal drug release (CIDR) devices, with supplemented with pregnant mare serum gonadotropin (PMSG) and prostaglandin (PG), for inducing estrus and pregnancy in goats, and to identify the most cost-effective regimen for intensive farming. During both breeding and non-breeding seasons, does were assigned totreatments: Group I (P4 sponge + PMSG), Group II (P4 sponge + PMSG + PG), and Group III (CIDR + PMSG + PG). We measured estrus response after device removal and pregnancy rates after artificial insemination (AI) were evaluated and analyzed serum hormone dynamics. Additionally, medication costs were calculated for each protocol. For the most effective protocol, we also determined ovulation timing, performed laparoscopic-assisted AI. Estrus onset occurred earlier in Groups II and III than in Group I during both trial seasons. Nevertheless, overall estrus and pregnancy rates did not differ significantly among the groups (P > 0.05), with Group II exhibiting the lowest pregnancy rate. Medication cost per does and per pregnancy were lowest for Group I. Under the Group I protocol, ovulation occurred at 32 h after estrus onset, and laparoscopic-assisted AI yielded a significantly higher pregnancy rate with fresh semen than with chilled semen (P < 0.05). Serum estradiol (E2) concentration at estrus onset was significantly higher in Group I than in Group II (P < 0.05), and luteinizing hormone (LH) levels at estrus onset and ovulation were significantly higher in Groups I and III than in Group II (P < 0.05). Serum P4, LH, and E2 profiles during the estrous cycle followed similar patterns across all groups. In conclusion, there was no significant difference in pregnancy rates between the three estrus synchronization protocols. However, Protocol I demonstrated the lowest per doe and per pregnancy medication costs. Based on cost-effectiveness considerations, the P4 sponge + PMSG protocol is recommended for use in intensive goat production systems.

To clarify the age-related differences in growth performance, meat quality, and the underlying molecular mechanisms of Shanbei white cashmere (SWC) goats, the slaughter performance and meat quality of 6-month-old (S group) and 12-month-old (T group) male goats were analyzed. This was combined with muscle transcriptome and untargeted metabolome analyses. The results showed that the T group had better growth performance, while the S group had superior meat quality. A total of 138 differentially expressed genes (DEGs) and 158 differentially expressed metabolites (DEMs) were identified, which are enriched in multiple pathways, and a meat quality-related gene-metabolite regulatory network was constructed. This study reveals the molecular mechanisms of age-dependent differences, providing theoretical support for goat breeding and slaughter strategy optimization.

The accumulation of heavy metals (HMs) from coal resource exploitation and coal-related industries poses serious ecological and health risks in the hinterland river sediments of Shenfu coal field in Northern China. Using data from 59 samples, the geo-accumulation index and ecological health risks of HMs were assessed probabilistically using Monte Carlo Simulation. Two coupling models were constructed in this study, integrating both the Positive Matrix Factorization and ecological health risk models to identify the risk levels of pollution sources in the Kuye River. The risk of HMs during the wet season was explored due to the lower concentrations and a broader range of pollution sources compared to the dry season. The Igeo value of Hg was greater than 1 in 69% of the samples, suggesting moderately contaminated sediments. According to the source-oriented coupling models (PMF-RI/HRA), coal-mining sources contributed to the overall ecological risk by 48.79%, primarily due to Hg (98.50%). Industrial sources (51.48%) were the largest contributors to carcinogenic risk, with Ni corresponding to the target HM. This indicated that different HMs originating from distinct pollution sources were responsible for ecological or carcinogenic health risks. The probabilistic health risk evaluation results indicated that children faced higher risks than adults, with over 94.07% of carcinogenic risks exceeding thresholds. Traffic sources followed, contributing 34.41% to ecological and 41.09% to carcinogenic risks. The results highlight the priority sources and target HMs based on specific sources in the mixed 'mining-industrial-traffic' areas, providing valuable insights for environmental protection and the development of risk prevention strategies in a typical energy industry area.