The RNA species SHR1 reacts with biocytin (epsilon-biotinoyl-L-lysine) in the presence of Ni(2+) or Pt(2+) to produce a metal-bridged complex that migrates more slowly than unreacted RNA in the presence of streptavidin (StrAv) on denaturing polyacrylamide gels. Mapping of reverse transcription pause sites identified G79 as a reactive nucleotide. G79 is near the 3' end of a 37 nucleotide core motif that is nearly as reactive as SHR1. SHR1 reacts with biocytin in the presence of Pt(2+) to yield a product that comigrates with the Ni(2+) product but that is much more stable, suggesting that the metal ion used in the reaction is present in the product, possibly linking the RNA to the amino acid. In support of this model, SHR1 shows a strong affinity for Ni(2+) in immobilized metal ion chromatography.
Nodes can behave as spring-like joints in woody plants. For plagiotropic shoots, distichous phyllotaxy results in stems that resist up-and-down bending more than lateral back-and-forth movement. Thus, they may more effectively absorb applied loads from fruits, animals, wind, rain, and snow and resist stresses due to gravity without cracking and breaking. Under windy conditions, nodes may improve damping by absorbing vibrational energy and thus reducing oscillation damage. The effect of plant nodes also has biomimetic design implications for architects and material engineers.
A node is the point of attachment of the leaf to the stem of a plant; gaps associated with nodes have been viewed as discontinuities of the stem vascular system. We tested the hypothesis that the node/gap is a spring-like joint that impacts stem flexibility even well after the leaves have been shed, with some stems specialized for elongation and others for flexibility. Four-point bending tests were done using an Instron Mechanical Testing Device with the independent variable being the number of nodes in the stem segment and dependent variables being Modulus of Elasticity (MOE), Modulus of Rupture (MOR), and xylem density. Node anatomy was examined microscopically to assess structure and function. The stiffness of the stem was inversely proportional to the frequency of leaf nodes. Surprisingly, xylem density was inversely proportional to the frequency of leaf nodes in stems of adult trees. The tissue around nodes/gaps consisted of twisted and contorted cells that may be effective at absorbing compressive and tensile stresses. Because nodes behave as spring-like joints, the frequency of nodes relates to function, with some stems specialized for vertical expansion and others for light capture and damping of wind stress. The ultimate stems on a tree are the most bendable, which may allow the trees to avoid breakage.
Numerous medical schools currently offer a master of arts (MA) in bioethics dual degree for physicians. A degree in bioethics enhances the care physicians provide to patients and prepares physicians to serve on ethics committees and consult services. Additionally, they may work on institutional and public policy issues related to ethics. Several physician assistant (PA) programs currently offer a master of public health (MPH) dual degree for PAs. A degree in public health prepares PAs for leadership roles in meeting community health needs. With the success of PA/MPH dual degree programs, we argue here that a PA/bioethics dual degree would be another opportunity to advance the PA profession and consider how such a program might be implemented. The article includes the individual perspectives of the authors, one of whom completed a graduatelevel certificate in bioethics concurrently with his 2-year PA program, while the other served as a bioethics program director.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.