An investigation into rugby union players' knowledge and understanding of concussion

Concussion amongst rugby union players’ is one of the highest and most common injuries that has been happening in the modern game. However, recently, previous rugby players have come forward with the physical effect that concussion has had on them from their early playing days, reducing their quality of like with everlasting effects. This means the uncertainty of players knowledge and understanding was at large, and wondering whether if players did know this information, would they take encountering a concussion more seriously. Therefore, this research study aims to investigate current rugby union players’ knowledge and understanding of concussion. The sample size consisted of 62 participants, including both males and females from both a university and a club setting, to get a comparison on their current knowledge. This research used a mixed methods approach by carrying out semi structured interviews and questionnaires to collect data. A process of coding a thematic analysis revealed key themes such as education players have had regarding concussion, what they believed were common signs and symptoms of concussion and their current knowledge to returning to play. The findings from this research indicated that males and females both from a university and a club setting had a large gap of knowledge regarding concussion including 62 responses in the questionnaires believed that headguards, mouth guards or shoulder pads prevent concussion. Other gaps included identifying incorrect signs and symptoms of concussion, such as neck pain, knocked out and ear discharge, as well as not having knowledge regarding the correct return to play protocol. There were also 4 participants who were unsure or did not believe players needed to be removed from play after sustaining a concussion. This study has shown the need to implement more concussion prevention strategies for both male and female’s players that can be disturbed to captains within a team as well as different settings such as club and university

The higher order C_n dispersion coefficients for the alkali atoms

The van der Waals coefficients, from C_11 through to C_16 resulting from 2nd, 3rd and 4th order perturbation theory are estimated for the alkali (Li, Na, K and Rb) atoms. The dispersion coefficients are also computed for all possible combinations of the alkali atoms and hydrogen. The parameters are determined from sum-rules after diagonalizing the fixed core Hamiltonian in a large basis. Comparisons of the radial dependence of the C_n/r^n potentials give guidance as to the radial regions in which the various higher-order terms can be neglected. It is seen that including terms up to C_10/r^10 results in a dispersion interaction that is accurate to better than 1 percent whenever the inter-nuclear spacing is larger than 20 a_0. This level of accuracy is mainly achieved due to the fortuitous cancellation between the repulsive (C_11, C_13, C_15) and attractive (C_12, C_14, C_16) dispersion forces.Comment: 8 pages, 7 figure

Detecting the Dusty Debris of Terrestrial Planet Formation

We use a multiannulus accretion code to investigate debris disks in the terrestrial zone, at 0.7-1.3 AU around a 1 solar mass star. Terrestrial planet formation produces a bright dusty ring of debris with a lifetime of at least 1 Myr. The early phases of terrestrial planet formation are observable with current facilities; the late stages require more advanced instruments with adaptive optics.Comment: 11 pages of text, 3 figures, accepted for ApJ Letters, additional info at http://cfa-www.harvard.edu/~kenyon/pf/terra/td

Does in utero exposure of antiepileptic drugs lead to failure to reach full cognitive potential?

AbstractA clinical scenario of a young female on 800mg of sodium valproate (VPA) who has recently failed lamotrigine (LTG) and levetiracetam (LEV) and who is currently planning a pregnancy is presented. Currently available data pertaining to the longer-term development of children exposed to antiepileptic drugs (AEDs) are reviewed along with considerations around the methodology and interpretation of such research. There is an accumulation of data highlighting significant risks associated with prenatal exposed to VPA, with the level of risk being mediated by dose. The majority of published evidence does not find a significant risk associated with carbamazepine (CBZ) exposure in utero for global cognitive abilities however the evidence for more specific cognitive skills are unclear. Limited data indicate that LTG may be a preferred treatment to VPA in terms of foetal outcome but further evidence is required. Too little data pertaining to LEV exposure is available and a lack of evidence regarding risk of this and other new AEDs should not be interpreted as evidence of safety

Transverse excitations of ultracold matter waves upon propagation past abrupt waveguide changes

The propagation of ultracold atomic gases through abruptly changing waveguide potentials is examined in the limit of non-interacting atoms. Time-independent scattering calculations of microstructured waveguides with discontinuous changes in the transverse harmonic binding potentials are used to mimic waveguide perturbations and imperfections. Three basic configurations are examined: step-like, barrier-like and well-like with waves incident in the ground mode. At low energies, the spectra rapidly depart from single-moded, with significant transmission and reflection of excited modes. The high-energy limit sees 100 percent transmission, with the distribution of the transmitted modes determined simply by the overlap of the mode wave functions and interference.Comment: 20 pages, 7 figures, under review PR

Planet formation around low mass stars: the moving snow line and super-Earths

We develop a semi-analytic model for planet formation during the pre-main sequence contraction phase of a low mass star. During this evolution, the stellar magnetosphere maintains a fixed ratio between the inner disk radius and the stellar radius. As the star contracts at constant effective temperature, the `snow line', which separates regions of rocky planet formation from regions of icy planet formation, moves inward. This process enables rapid formation of icy protoplanets that collide and merge into super-Earths before the star reaches the main sequence. The masses and orbits of these super-Earths are consistent with super-Earths detected in recent microlensing experiments.Comment: accepted by ApJ Letter

The Challenge of the Future

Commencement address given by D. Allan Bromley, Director of the White House Office of Science and Technology and Chair of the President's Council of Science and Technology, to the Winter 1991 graduating class of The Ohio State University, St. John Arena, Columbus, Ohio, March 22, 1991

Ilmu Ekonomi Dan Pembangunan Indonesia (a Development Manifesto for Indonesia)

Economic development must be thought of as a process in which a gradual and self-reinforcing evolution of institutions (“working rules”) gets underway, all the while being informed and guided by the explicit purpose of: (1) encouraging economic growth; (2) enhancing the equality with which the benefits of that growth are shared; and (3) assuring that natural assets are not degraded in a manner that will compromise in the future either continued growth, or continued sharing of the benefits of growth. We see that institutions are central to growth, poverty alleviation, and sustainability. We also see that economic growth – increases in per capita GDP (or GNP) – is not sufficient unless it is also accompanied by a simultaneous and plausibly sustainable decrease in social inequality, and unless growth is not destructive of future growth and development.The process of economic development must incorporate three central ideas. These concepts concern ethics, law, and economics. Ethics concern collective perceptions of what is good and just not only in the present, but in terms of objectives to be pursued in the future. Law concern the application of the collective power to mediate and to enforce that ethical consensus – always with an eye to the future. Economics concerns the calculation of profit and loss predicated upon: (1) the ethical base of the nation state as a going concern; and (2) upon the legal foundations that give substance and content to the prior ethical foundations of that nation state

The periodic standing-wave approximation: post-Minkowski computation

The periodic standing wave method studies circular orbits of compact objects coupled to helically symmetric standing wave gravitational fields. From this solution an approximation is extracted for the strong field, slowly inspiralling motion of black holes and binary stars. Previous work on this model has dealt with nonlinear scalar models, and with linearized general relativity. Here we present the results of the method for the post-Minkowski (PM) approximation to general relativity, the first step beyond linearized gravity. We compute the PM approximation in two ways: first, via the standard approach of computing linearized gravitational fields and constructing from them quadratic driving sources for second-order fields, and second, by solving the second-order equations as an ``exact'' nonlinear system. The results of these computations have two distinct applications: (i) The computational infrastructure for the ``exact'' PM solution will be directly applicable to full general relativity. (ii) The results will allow us to begin supplying initial data to collaborators running general relativistic evolution codes.Comment: 19 pages, 3 figures, 1 table, RevTe