Structure of ratcheted ribosomes with tRNAs in hybrid states

During protein synthesis, tRNAs and mRNA move through the ribosome between aminoacyl (A), peptidyl (P), and exit (E) sites of the ribosome in a process called translocation. Translocation is accompanied by the displacement of the tRNAs on the large ribosomal subunit toward the hybrid A/P and P/E states and by a rotational movement (ratchet) of the ribosomal subunits relative to one another. So far, the structure of the ratcheted state has been observed only when translation factors were bound to the ribosome. Using cryo-electron microscopy and classification, we show here that ribosomes can spontaneously adopt a ratcheted conformation with tRNAs in their hybrid states. The peptidyl-tRNA molecule in the A/P state, which is visualized here, is not distorted compared with the A/A state except for slight adjustments of its acceptor end, suggesting that the displacement of the A-site tRNA on the 50S subunit is passive and is induced by the 30S subunit rotation. Simultaneous subunit ratchet and formation of the tRNA hybrid states precede and may promote the subsequent rapid and coordinated tRNA translocation on the 30S subunit catalyzed by elongation factor G.     

Choroidal vascularity index in pseudoexfoliative glaucoma

International Ophthalmology - To evaluate choroidal vascular involvement in pseudoexfoliative glaucoma (PEXG) by applying the choroidal vascularity index (CVI) to optic coherence tomography (OCT)...     

The Status of Legal Authority for Injury Prevention Practice in State Health Departments

Despite the potential for public health strategies to decrease the substantial burden of injuries, injury prevention infrastructure in state health departments is underdeveloped. We sought to describe the legal support for injury prevention activities at state health departments.We searched the Lexis database for state laws providing authority for those activities, and categorized the scope of those laws. Only 10 states have authority that covers the full scope of injury prevention practice; in the others, legal authority is piecemeal, nonspecific, or nonexistent.More comprehensive legal authority could help health departments access data for surveillance, work with partners, address sensitive issues, and garner funding. Efforts should be undertaken to enhance legal support for injury prevention activities across the country.APPROXIMATELY 50 MILLION nonfatal injuries1 and 180 000 deaths from injury occur each year in the United States. Lifetime costs associated with medical expenses and lost productivity from all injury types are estimated to exceed $400 billion.2 The public health approach to injury prevention, based on the core public health functions of assessment, policy development, and assurance,3 includes surveillance to define the scope of the problem, identification of risk and protective factors, development and testing of prevention and control strategies, and assurance of widespread adoption of those strategies that prove to be effective.4 This approach could have a large positive impact on the public’s health.Although injuries impose a substantial public health burden, and effective public health strategies could decrease that burden, public health practice has been relatively slow to take on injury prevention. In recognition that public health needed to increase its focus on injury prevention, the Centers for Disease Control and Prevention created its National Center for Injury Prevention and Control in 1992 (although injury and violence work at the agency dates back to the late 1970s and early 1980s). State and local health department infrastructure to address injuries has been growing since that time as well, but the injury prevention infrastructure in most health departments, if it exists at all, remains small and underfunded relative to the magnitude of the injury problem.Government public health agencies function within an authorizing environment defined by statute and sometimes clarified by rule or regulation.5 Although broad statutory authority allows agency leaders some freedom to define their activities, if the agency moves into a new arena without unambiguous legal authority, its activities may be open to challenge, particularly if they involve regulation or are fraught with political implications, as are so many issues in public health, including injury prevention. Clear authority to engage in injury prevention activities is essential if public health agencies are to engage robustly in this area.We investigated laws in all 50 states that pertain to authorizing health departments to undertake a robust slate of injury prevention activities. We found that the scope of legal authority for injury prevention activities varies widely across the country regarding which kinds of injuries are addressed and which legal tools an injury prevention program is explicitly authorized to use. If state health departments are to fully realize their potential to prevent injuries, efforts to make the legal basis for the full range of injury prevention activities more comprehensive across the country should be undertaken.     

Sail training: an innovative approach to graduate nurse preceptor development.

A 1-day sail-training program that aims to increase graduate nurse preceptor skills was evaluated. Preliminary results suggest that this experiential learning is an effective way to develop graduate nurse preceptors. Awareness of graduate nurses' needs has been heightened, and skills in clinical teaching have been developed. It is indicated from the limited results that the outcomes are sustained over time, but further evaluation is needed.