The Effects of Switching to On-Demand on Learning Outcomes in First-Year PBL Courses

本研究では，対面授業とオンデマンド授業の違いが，初年次PBL科目における学習成果の違いに与える影響を検討した。分析の結果，オンデマンド授業において協同作業認識尺度における協同効用のスコアが対面授業より高い傾向がみられた一方で，協同作業をネガティブに評価する尺度である互恵懸念のスコアが対面授業より低い傾向がみられた。加えて，学習成果全体を観察した場合，オンデマンド授業において，授業に適応的でない学生数が減少し適応的な学生数が増加するという改善がみられた。In this study, we examined the effect of the difference between face-to-face and on-demand classes on the differences in learning outcomes in first-year PBL courses. As a result, it was found that the score of the usefulness of cooperation in the belief in cooperation scale tended to be higher in the on-demand class than in the face-to-face class, while the score of inequity, which is a scale to evaluate collaborative work negatively, tended to be lower in the on-demand class than in the face-to-face class. In addition, when observing the overall learning outcomes, the number of students who were not adaptive to the class decreased and the number of adaptive students increased in the on-demand class

An inducible RNA interference system in Physcomitrella patens reveals a dominant role of augmin in phragmoplast microtubule generation

Mitosis is a fundamental process of eukaryotic cell proliferation. However, the molecular mechanisms underlying mitosis remain poorly understood in plants partly because of the lack of an appropriate model cell system in which loss-of-function analyses can be easily combined with high-resolution microscopy. Here, we developed an inducible RNA interference (RNAi) system and three-dimensional time-lapse confocal microscopy in the moss Physcomitrella patens that allowed in-depth phenotype characterization of the moss genes essential for cell division. We applied this technique to two microtubule regulators, augmin and γ-tubulin complexes, whose mitotic roles remain obscure in plant cells. Live imaging of caulonemal cells showed that they proceed through mitosis with continual generation and self-organization of acentrosomal microtubules. We demonstrated that augmin plays an important role in γ-tubulin localization and microtubule generation from prometaphase to cytokinesis. Most evidently, microtubule formation in phragmoplasts was severely compromised after RNAi knockdown of an augmin subunit, leading to incomplete expansion of phragmoplasts and cytokinesis failure. Knockdown of the γ-tubulin complex affected microtubule formation throughout mitosis. We conclude that postanaphase microtubule generation is predominantly stimulated by the augmin/γ-tubulin machinery in moss and further propose that this RNAi system serves as a powerful tool to dissect the molecular mechanisms underlying mitosis in land plants

Isolation of Shiga Toxin-Producing Escherichia coli from the Surfaces of Beef Carcasses in Slaughterhouses in Japan

Shiga toxin-producing E. coli (STEC) is an important foodborne pathogen worldwide. It is necessary to control and prevent STEC contamination on beef carcasses in slaughterhouses because STEC infection is associated with beef consumption. However, the frequencies of STEC contamination of beef carcasses in various slaughterhouses in Japan are not well known. Herein, we investigated the contamination of beef carcasses with STEC in slaughterhouses to assess the potential risks of STEC. In total, 524 gauze samples were collected from the surfaces of beef carcasses at 12 domestic slaughterhouses from November 2020 to February 2023. The samples were measured for aerobic plate counts and tested for pathogenic genes (stx and eae) and major O-serogroups (O26, O45, O103, O111, O121, O145, and O157) by real-time PCR screening. Subsequently, immunomagnetic separation (IMS) was performed on samples positive for stx, eae, and at least one of the seven O-serogroups of STEC. Isolation process without IMS was performed on samples positive for stx, including those subjected to IMS. STEC O157:H7 and stx-positive E. coli other than serotype O157:H7 were isolated from 0.6% and 4.6% of beef carcass surfaces, respectively. Although the STEC O157:H7 isolation rate was low and stx-positive E. coli other than serotype O157:H7 belonged to minor O-serogroups, the results mean a risk of foodborne illness. Furthermore, a moderate correlation was observed between aerobic plate counts and detection rates of stx-positive samples by real-time PCR screening. The STEC O157:H7 isolated facilities showed higher values on aerobic plate counts and detection rates of stx-positive samples than the mean values of total samples. Therefore, these results suggest that it is important to evaluate hygiene treatments against beef carcasses for the reduction of STEC contamination risk, particularly in facilities with high aerobic plate counts