5,394 research outputs found

    A CA+ Pair Adjacent to a Sheared GA or AA Pair Stabilizes Size-Symmetric RNA Internal Loops†

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    ABSTRACT: RNA internal loops are often important sites for folding and function. Residues in internal loops can have pKa values shifted close to neutral pH because of the local structural environment. A series of RNA internal loops were studied at different pH by UV absorbance versus temperature melting experiments and imino proton nuclear magnetic resonance (NMR). A stabilizing CA pair forms at pH 7 in the CG CA AA and AA nearest neighbors when the CA pair is the first noncanonical pair (loop-terminal pair) in 3 3 nucleotide and larger size-symmetric internal loops. These CG C

    Making a financial time machine:a multitouch application to enable interactive 3-D visualization of distant savings goals

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    Financial planning and decision making for the general public continues to vex and perplex in equal measure. Whilst the tools presented by a typical desktop computer should make the task easier, the recent financial crisis confirms the increasing difficulty that people have in calculating the benefits of deferring consumption for future gains (i.e. Saving). We present an interactive concept demonstration for Microsoft SurfaceTM that tackles two of the key barriers to saving decision making. Firstly we show an interface that avoid the laborious writing down or inputting of data and instead embodies the cognitive decision of allocation of resources in a physical gesture based interface, where the scale of the investment or expenditure correlates with the scale of the gesture. Second we show how a fast-forward based animation can demonstrate the impact of small increments in savings to a long term savings goal in a strategy game-based, interactive format. The platform uses custom software (XNATM format) as opposed to the more usual WPFTM format found on Surface applications. This enables dynamic 3-D graphical icons to be used to maximize the interactive appeal of the interface. Demonstration and test trial feedback indicates that this platform can be adapted to suit the narrative of individual purchasing decisions to inform educate diverse user groups about the long term consequences of small financial decisions

    Practices and perceptions of strength and conditioning in female golf: a survey study of touring professional players

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    The aim of the study was to provide an understanding of current practices and perceptions of strength and conditioning (S&C) training in female touring professionals. A cross-sectional, explorative survey was undertaken and contained 30 questions separated into four sections: i) general participant information, ii) S&C practices, iii) Likert scale questions on S&C for golf performance, and iv) knowledge and awareness of S&C. A total of 102 players completed the survey with a combination of multiple-choice questions (MCQs), open-ended questions, and Likert Scale style questions utilised throughout. Results showed that ≥ 94% of players believed that strength and power in both the lower and upper body, in addition to flexibility, were the most important physical characteristics to complement golf shot metrics (e.g., clubhead speed [CHS], ball speed, carry distance, etc.). However, 26% of players conducted S&C training only in the off-season, with 21% suggesting that they had a fear of injury from S&C training. When considering the barriers to undertaking S&C training, the most common reasons included time constraints (20%) and players wanting to prioritise golf practice (15%). Finally, 58% of players believed that training in the weight room should replicate the golf swing. Although it is positive to see that the main physical characteristics for golf are well-understood by professional players, it is also evident that further education and knowledge translation is required relating to the application of S&C training for performance enhancement and injury risk mitigation purposes

    Observations of Outflowing UV Absorbers in NGC 4051 with the Cosmic Origins Spectrograph

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    We present new Hubble Space Telescope (HST)/Cosmic Origins Spectrograph observations of the Narrow-Line Seyfert 1 galaxy NGC 4051. These data were obtained as part of a coordinated observing program including X-ray observations with the Chandra/High Energy Transmission Grating (HETG) Spectrometer and Suzaku. We detected nine kinematic components of UV absorption, which were previously identified using the HST/Space Telescope Imaging Spectrograph. None of the absorption components showed evidence for changes in column density or profile within the \sim 10 yr between the STIS and COS observations, which we interpret as evidence of 1) saturation, for the stronger components, or 2) very low densities, i.e., n_H < 1 cm^-3, for the weaker components. After applying a +200 km s^-1 offset to the HETG spectrum, we found that the radial velocities of the UV absorbers lay within the O VII profile. Based on photoionization models, we suggest that, while UV components 2, 5 and 7 produce significant O VII absorption, the bulk of the X-ray absorption detected in the HETG analysis occurs in more highly ionized gas. Moreover, the mass loss rate is dominated by high ionization gas which lacks a significant UV footprint.Comment: 41 pages, 10 Figures; accepted for publication in the Astrophysical Journa

    Exact Results for the Bipartite Entanglement Entropy of the AKLT spin-1 chain

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    We study the entanglement between two domains of a spin-1 AKLT chain subject to open boundary conditions. In this case the ground-state manifold is four-fold degenerate. We summarize known results and present additional exact analytical results for the von Neumann entanglement entropy, as a function of both the size of the domains and the total system size for {\it all} four degenerate ground-states. In the large l,Ll,L limit the entanglement entropy approaches ln(2)\ln(2) and 2ln(2)2\ln(2) for the STz=±1S^z_T=\pm 1 and STz=0S^z_T=0 states, respectively. In all cases, it is found that this constant is approached exponentially fast defining a length scale ξ=1/ln(3)\xi=1/\ln(3) equal to the known bulk correlation length.Comment: 11 pages, 3 figure

    Conformational ensembles of RNA oligonucleotides from integrating NMR and molecular simulations

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    RNA molecules are key players in numerous cellular processes and are characterized by a complex relationship between structure, dynamics, and function. Despite their apparent simplicity, RNA oligonucleotides are very flexible molecules, and understanding their internal dynamics is particularly challenging using experimental data alone. We show how to reconstruct the conformational ensemble of four RNA tetranucleotides by combining atomistic molecular dynamics simulationswith nuclear magnetic resonance spectroscopy data. The goal is achieved by reweighting simulations using a maximum entropy/Bayesian approach. In this way, we overcome problems of current simulation methods, as well as in interpreting ensemble- and time-averaged experimental data. We determine the populations of different conformational states by considering several nuclear magnetic resonance parameters and point toward properties that are not captured by state-of-the-art molecular force fields. Although our approach is applied on a set of model systems, it is fully general and may be used to study the conformational dynamics of flexible biomolecules and to detect inaccuracies in molecular dynamics force fields
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