4,657 research outputs found

    Life History Attributes of Asian Carps in the Upper Mississippi River System

    Get PDF
    INTRODUCTION: The Upper Mississippi River (UMR) system starts at the confluence of the Ohio River at Cairo, Illinois, and serves as a conduit for many aquatic invasive species to enter the waterways of the central and northern interior of the United States, including the Great Lakes. One well-established group found in this waterway is the Asian carps including the common carp Cyprinus carpio, grass carp Ctenopharyngodon idella, and two recent invaders, the bighead car

    Models of Cuspy Triaxial Galaxies

    Get PDF
    We construct numerical models of mildly triaxial elliptical galaxies with central density cusps. Using a technique we call ``adiabatic squeezing'', we begin with a spherical gamma=1 Hernquist model and apply a drag to the velocities of the particles along each principle axis. The final models are stable in isolation, preserving their density structure and figure shape over many dynamical timescales. The density profile and axial ratios compare well to the observed properties of elliptical galaxies. The orbital structure of these models show a mixture of tubes, boxes, and boxlets, as expected for triaxial systems, with very few chaotic orbits. These N-body realizations of cuspy triaxial galaxies provide a basis for the study of the dynamical evolution of elliptical galaxies.Comment: 14 pages, 7 figures. Accepted by Ap

    One-step volumetric additive manufacturing of complex polymer structures.

    Get PDF
    Two limitations of additive manufacturing methods that arise from layer-based fabrication are slow speed and geometric constraints (which include poor surface quality). Both limitations are overcome in the work reported here, introducing a new volumetric additive fabrication paradigm that produces photopolymer structures with complex nonperiodic three-dimensional geometries on a time scale of seconds. We implement this approach using holographic patterning of light fields, demonstrate the fabrication of a variety of structures, and study the properties of the light patterns and photosensitive resins required for this fabrication approach. The results indicate that low-absorbing resins containing ~0.1% photoinitiator, illuminated at modest powers (~10 to 100 mW), may be successfully used to build full structures in ~1 to 10 s

    Elevated O-GlcNAc levels activate epigenetically repressed genes and delay mouse ES cell differentiation without affecting naive to primed cell transition

    Get PDF
    The differentiation of mouse embryonic stem (ES) cells is controlled by the interaction of multiple signaling pathways, typically mediated by post-translational protein modifications. The addition of O-linked N-acetylglucosamine (O-GlcNAc) to serine and threonine residues of nuclear and cytoplasmic proteins is one such modification (O-GlcNAcylation), whose function in ES cells is only now beginning to be elucidated. Here we demonstrate that the specific inhibition of O-GlcNAc hydrolase (Oga) causes increased levels of protein O-GlcNAcylation and impairs differentiation of mouse ES cells both in serum-free monolayer and in embryoid bodies (EBs). Use of reporter cell lines demonstrates that Oga inhibition leads to a reduction in the number of Sox1-expressing neural progenitors generated following induction of neural differentiation, as well as maintained expression of the ES cell marker Oct4 (Pou5f1). In EBs expression of mesodermal and endodermal markers is also delayed. However, the transition of naïve cells to primed pluripotency indicated by Rex1 (Zfp42), Nanog, Esrrb and Dppa3 downregulation and Fgf5 upregulation remains unchanged. Finally, we demonstrate that increased O-GlcNAcylation results in upregulation of genes normally epigenetically silenced in ES cells, supporting the emerging role for this protein modification in the regulation of histone modifications and DNA methylation. Stem Cells 2014

    Active Gaming as a Form of Exercise to Induce Hypoalgesia

    Get PDF
    Objective: An acute bout of moderate-to-vigorous exercise temporarily reduces pain sensitivity in healthy adults. Recently, active gaming has been rising in popularity as a means of light-to-moderate exercise and may be particularly suitable for deconditioned individuals. Whether the physical activity elicited in active games can produce a hypoalgesic effect remains unknown. The purpose of this study was to determine whether active videogames can reduce pressure and heat pain sensitivity in healthy adults. We also evaluated the relationship between the physical activity elicited by the games and the magnitude of the hypoalgesic response. Materials and Methods: Twenty-one healthy adults played four different active games on separate days, including Microsoft® Kinect Xbox® One's Fighter Within and Sports Rival's Tennis, and Nintendo® Wii™ Sports' Boxing and Tennis. Heat pain thresholds on the forearm and pressure pain thresholds (PPTs) on the trapezius and forearm were assessed immediately before and after a 15-minute active gaming or control session. Minutes spent in sedentary time and moderate-to-vigorous physical activity (MVPA) during active gaming were measured with an accelerometer. Results: The analyses revealed that PPTs at the forearm and trapezius significantly increased from pretest to posttest following Kinect Fighter Within. PPTs at the trapezius also significantly increased from pretest to posttest following Wii Boxing. The magnitude of the hypoalgesic response was significantly correlated with MVPA and sedentary time during gameplay. Conclusion: These results suggest that an active gaming session played at a moderate intensity is capable of temporarily reducing pain sensitivity

    Valuing Transgenic Cotton Technologies Using a Risk/Return Framework

    Get PDF
    Stochastic Efficiency with Respect to a Function (SERF) is used to rank transgenic cotton technology groups and place an upper and lower bound on their value. Yield and production data from replicated plot experiments are used to build cumulative distribution functions of returns for nontransgenic, Roundup Ready, Bollgard, and stacked gene cotton cultivars. Analysis of Arkansas data indicated that the stacked gene and Roundup Ready technologies would be preferred by a large number of risk neutral and risk averse producers as long as the costs of the technology and seed are below the lower bounds calculated in this manuscript.cotton, financial risk, market value, SERF, transgenic, Agribusiness, Crop Production/Industries, Risk and Uncertainty, Q12, Q16,
    corecore