Signal recognition particle binds to translating ribosomes before emergence of a signal anchor sequence.

The bacterial signal recognition particle (SRP) is part of the machinery that targets ribosomes synthesizing membrane proteins to membrane-embedded translocons co-translationally. Recognition of nascent membrane proteins occurs by virtue of a hydrophobic signal-anchor sequence (SAS) contained in the nascent chain, usually at the N terminus. Here we use fluorescence-based stopped-flow to monitor SRP-ribosome interactions with actively translating ribosomes while an SRP substrate is synthesized and emerges from the peptide exit tunnel. The kinetic analysis reveals that, at cellular concentrations of ribosomes and SRP, SRP rapidly binds to translating ribosomes prior to the emergence of an SAS and forms an initial complex that rapidly rearranges to a more stable engaged complex. When the growing peptide reaches a length of ∼50 amino acids and the SAS is partially exposed, SRP undergoes another conformational change which further stabilizes the complex and initiates targeting of the translating ribosome to the translocon. These results provide a reconciled view on the timing of high-affinity targeting complex formation, while emphasizing the existence of preceding SRP recruitment steps under conditions of ongoing translation

Alien Registration- Mercier, Edmond E J. (Auburn, Androscoggin County)

https://digitalmaine.com/alien_docs/30606/thumbnail.jp

Physical Education Teachers\u27 Experiences With Remote Instruction During The Initial Phase Of The Covid-19 Pandemic

This study investigated physical education (PE) teachers\u27 experiences with remote instruction in the United States during the initial outbreak of COVID-19. PE teachers (n = 4,362) from all 50 states completed a survey identifying their experiences with remote instruction in May, 2020. Survey responses were analyzed by geographic region, district type, and school level. Teachers reported having students submit assignments (51% yes), using video instruction (37% yes), being less effective when instructing remotely (20% yes), and emphasizing student outcomes focused on health-related fitness (32% yes), and physical activity value/ enjoyment (43% yes). Access to technology (40% yes) and required student assignments (43% yes) were lowest among teachers from the South. Rural teachers reported the least access to technology (37% yes) and rated themselves as least effective (24% yes). Secondary level teachers reported the highest percentage of required assignments (84% yes). Teachers\u27 responses identify unique challenges to delivering equitable and effective remote PE instruction

The effects of room design on computer-supported collaborative learning in a multi-touch classroom.

While research indicates that technology can be useful for supporting learning and collaboration, there is still relatively little uptake or widespread implementation of these technologies in classrooms. In this paper, we explore one aspect of the development of a multi-touch classroom, looking at two different designs of the classroom environment to explore how classroom layout may influence group interaction and learning. Three classes of students working in groups of four were taught in the traditional forward-facing room condition, while three classes worked in a centered room condition. Our results indicate that while the outcomes on tasks were similar across conditions, groups engaged in more talk (but not more off-task talk) in a centered room layout, than in a traditional forward-facing room. These results suggest that the use of technology in the classroom may be influenced by the location of the technology, both in terms of the learning outcomes and the interaction behaviors of students. The findings highlight the importance of considering the learning environment when designing technology to support learning, and ensuring that integration of technology into formal learning environments is done with attention to how the technology may disrupt, or contribute to, the classroom interaction practices

Twitter in the collaborative classroom: micro-blogging for in-class collaborative discussions

While small group discussion during undergraduate classes is an important pedagogic strategy, there are two primary concerns for instructors how to monitor the conversation that goes on within groups, and how to ensure that ideas that emerge within the groups become part of the classroom discourse. In this paper, we describe a design-experiment conducted in two sections of the same undergraduate education class, exploring the use of Twitter, and a shared display of the Twitter-chat, to address these issues. We describe three iterations of the use of Twitter in the classes, and our reflections on how it influenced the teaching experience. Data from student surveys indicates that students had minimal experience using Twitter for academic activities prior to participation in this class and that they felt Twitter was a valuable tool to support their in-class learning activities. The teaching team found that the use of Twitter kept students on task and focused on the activity, but expressed some concern about the depth of engagement with ideas during the task

International media and economic policy: A comparative media analysis of 2002 U.S. steel tariffs [abstract]

Abstract only availableThis paper compares American and European media coverage of the U.S. Emergency Safeguard Measures for steel which were imposed from March 2002-Dec. 2003 and levied tariffs of up to 30% on some steel imports. Of European Union members, the United Kingdom and France were among the most heavily affected by the tariffs. Mainstream newspapers in those countries presented mainly negative information and opinions of the U.S. policy. There were no significant differences between British and French coverage of this issue. In comparison, U.S. sources were predominantly neutral. However, headlines and prominent articles in all countries often reflected negative attitudes, and the most opinionated language came from journalists themselves, not outside sources, giving quantitative support to theories of chronic press negativity