Critical Public Health最新文献

This study aimed to assess the effects of embryonic developmental stage, quality grade, and fresh or frozen/thawed conditions on the pregnancy rate and sex ratio of live offspring in Hanwoo (Bos taurus coreanae) cows. The quality and developmental stage of in vivo-derived (IVD) transferred embryos were evaluated using the standard criteria of the International Embryo Technology Society. The recipient cows were synchronized using conventional (estradiol benzoate and progesterone) protocols before embryo transfer. Embryos were transferred to 297 cows, and pregnancy was monitored for 60-70 days after embryo transfer. The pregnancy rates of fresh and frozen/thawed embryos were 56.90% and 52.49%, respectively. Pregnancy rates varied according to embryo quality (56.18% for grade 1 vs. 36.67% for grade 2). Pregnancy rates also varied by developmental stage and cryopreservation (67.86% vs. 63.49% for stage 4-1, 64.00% vs. 54.72% for 5-1, and 50.00% vs. 47.83% for 6-1, in fresh embryos vs. frozen/thawed embryos, respectively). For stage 7-1, the pregnancy rates were 72.73% for fresh embryos and 20.00% for frozen/thawed embryos. In 66 fresh embryos, the sex ratio of live offspring was 5:5, whereas it was 4(female):6(male) for frozen/thawed embryos among the 95 frozen/thawed embryos. The miscarriage rate was approximately 3% higher for frozen/thawed embryos than for fresh embryos (18.1% for fresh vs. 21.1% for frozen). Seasonal fertility rates were 33.3% in spring, 55.67% in summer, 52.8% in autumn, 60.0% in winter. The following male-to-female ratios were observed in different seasons: 6.7:3.3 in spring, 4.0:6.0 in summer, 5.5:4.5 in autumn, and 3.3:6.7 in winter. The current data revealed no significant differences in pregnancy rates between fresh and frozen/thawed IVD embryos. However, there was a lower pregnancy rate with advanced-stage frozen/thawed embryos (stage 7-1). The current study provides comprehensive results for the better optimization of embryo transfer in Hanwoo cattle to obtain the desired fertility rate, pregnancy rate, and sex ratio of calves. These results provide important insights into the factors that influence the viability and success of IVD embryo transfer in Hanwoo cows and may have practical applications for improving breeding programs and reducing production costs.

Antimicrobial resistance (AMR) is often referred to as a complex problem embedded in a complex system. Despite this insight, interventions in AMR, and in particular in antibiotic prescribing, tend to be narrowly focused on the behaviour of individual prescribers using the tools of performance monitoring and management rather than attempting to bring about more systemic change. In this paper, we aim to elucidate the nature of the local antibiotic prescribing 'system' based on 71 semi-structured interviews undertaken in six local areas across the United Kingdom (UK). We applied complex systems theory and systems mapping methods to our qualitative data to deepen our understanding of the interactions among antibiotic prescribing interventions and the wider health system. We found that a complex and interacting set of proximal and distal factors can have unpredictable effects in different local systems in the UK. Ultimately, enacting performance management-based interventions in the absence of in-depth contextual understandings about other pressures prescribers face is a recipe for temporary solutions, waning intervention effectiveness, and unintended consequences. We hope our insights will enable policy makers and academics to devise and evaluate interventions in future in a manner that better reflects and responds to the dynamics of complex local prescribing systems.