59,453 research outputs found

    Look right! A retrospective study of pedestrian accidents involving overseas visitors to London

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    Introduction: Research within the European Union has shown international visitors to have a higher injury mortality than residents. Traffic accidents are the leading cause of injury-related death among overseas visitors and evidence suggests overseas visitors are at a greater risk of being involved in road traffic accidents than the resident population. Little information looks specifically at pedestrian injuries to overseas visitors. Pedestrian deaths account for 21% of all UK road deaths. Methods: A retrospective database review of London helicopter emergency medical service (HEMS) missions was undertaken to examine the number and type of missions to overseas visitors, specifically examining pedestrian incidents. Results: Of 121 missions to overseas visitors, 74 (61%) involved the visitor as a pedestrian struck by a vehicle. Thirty-five pedestrians (47%) were struck by a bus and 20 by a car (27%). Fourteen patients (19%) had an initial Glasgow coma scale score of 3–8, suggesting severe head injury and half of all patients required prehospital intubation (38/74, 51%). Mortality was 16% (12/74%) and 62 patients (84%) survived to hospital discharge. Of 39 patients admitted to the Royal London Hospital, the average injury severity score (ISS%) was 23.0 (ISS >15 denotes severe trauma) with a mean inpatient stay of 17.9 days. Conclusion: During the 7-year period studied, 61% of HEMS missions to overseas visitors involved a pedestrian being struck by a vehicle, compared with 16% of missions to UK residents. For HEMS missions, serious trauma to pedestrians is disproportionally more common among the visitor population to London

    A 10-year Study of Factors Associated with Alcohol Treatment Use and Non-use in a U.S. Population Sample

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    Background This study seeks to identify changes in perceived barriers to alcohol treatment and predictors of treatment use between 1991–92 and 2001–02, to potentially help understand reported reductions in treatment use at this time. Social, economic, and health trends during these 10 years provide a context for the study. Methods Subjects were Whites, Blacks, and Hispanics. The data were from the National Longitudinal Alcohol Epidemiologic Survey (NLAES) and the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). We conducted two analyses that compared the surveys on: 1) perceived treatment barriers for subjects who thought they should get help for their drinking, and 2) variables predicting past-year treatment use in an alcohol use disorder subsample using a multi-group multivariate regression model. Results In the first analysis, those barriers that reflected negative beliefs and fears about seeking treatment as well as perceptions about the lack of need for treatment were more prevalent in 2001–02. The second analysis showed that survey year moderated the relationship between public insurance coverage and treatment use. This relationship was not statistically significant in 1991–92 but was significant and positive in 2001–02, although the effect of this change on treatment use was small. Conclusions Use of alcohol treatment in the U.S. may be affected by a number of factors, such as trends in public knowledge about treatment, social pressures to reduce drinking, and changes in the public financing of treatment

    Shapeshifting as Infrastructural Storytelling:Comics about the Taxibot’s Conflicting Narratives

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    What are the stories we tell about infrastructures and what stories do infrastructures tell (about) us? We propose a paper in a hybrid verbo-visual format, including comic-pages created by Giada Peterle and based on Tina Harris’s keynote at the 2022 GMHC conference, autoethnographic notes, and visuals collected during fieldwork. Through experimenting with graphic storytelling, we highlight examples of infrastructural revelation and concealment, drawing on the figure of the shapeshifter as both a metaphor and a method for mobilising infrastructural imagination. What unites shapeshifters in many of the stories and myths we read is how they are taken up in different ways; how they simultaneously present both the potential to improve human lives as well as produce fear due to their unpredictability. By focusing specifically on the narrative of one shapeshifting infrastructure—the Taxibot, a vehicle designed to cut down on carbon emissions and improve efficiency at airports—we use comics as a research practice for exploring this metaphor and developing a broader understanding of how mobile lives and imaginaries shape infrastructure (and vice versa). We argue that paying closer attention to storytelling can generate new understandings of the uneven nexus between infrastructures and mobile lives, weaving in our understanding of infrastructural im/mobilities

    Landau Expansion for the Kugel-Khomskii t2gt_{2g} Hamiltonian

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    The Kugel-Khomskii (KK) Hamiltonian for the titanates describes spin and orbital superexchange interactions between d1d^1 ions in an ideal perovskite structure in which the three t2gt_{2g} orbitals are degenerate in energy and electron hopping is constrained by cubic site symmetry. In this paper we implement a variational approach to mean-field theory in which each site, ii, has its own n×nn \times n single-site density matrix \rhov(i), where nn, the number of allowed single-particle states, is 6 (3 orbital times 2 spin states). The variational free energy from this 35 parameter density matrix is shown to exhibit the unusual symmetries noted previously which lead to a wavevector-dependent susceptibility for spins in α\alpha orbitals which is dispersionless in the qαq_\alpha-direction. Thus, for the cubic KK model itself, mean-field theory does not provide wavevector `selection', in agreement with rigorous symmetry arguments. We consider the effect of including various perturbations. When spin-orbit interactions are introduced, the susceptibility has dispersion in all directions in q{\bf q}-space, but the resulting antiferromagnetic mean-field state is degenerate with respect to global rotation of the staggered spin, implying that the spin-wave spectrum is gapless. This possibly surprising conclusion is also consistent with rigorous symmetry arguments. When next-nearest-neighbor hopping is included, staggered moments of all orbitals appear, but the sum of these moments is zero, yielding an exotic state with long-range order without long-range spin order. The effect of a Hund's rule coupling of sufficient strength is to produce a state with orbital order.Comment: 20 pages, 5 figures, submitted to Phys. Rev. B (2003

    Breakdown of Hydrodynamics in a Simple One-Dimensional Fluid

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    We investigate the behavior of a one-dimensional diatomic fluid under a shock wave excitation. We find that the properties of the resulting shock wave are in striking contrast with those predicted by hydrodynamic and kinetic approaches, e.g., the hydrodynamic profiles relax algebraically toward their equilibrium values. Deviations from local thermodynamic equilibrium are persistent, decaying as a power law of the distance to the shock layer. Non-equipartition is observed infinitely far from the shock wave, and the velocity-distribution moments exhibit multiscaling. These results question the validity of simple hydrodynamic theories to understand collective behavior in 1d fluids.Comment: 4 pages, 5 figure

    Quantum Gravity Effects in Black Holes at the LHC

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    We study possible back-reaction and quantum gravity effects in the evaporation of black holes which could be produced at the LHC through a modification of the Hawking emission. The corrections are phenomenologically taken into account by employing a modified relation between the black hole mass and temperature. The usual assumption that black holes explode around 11 TeV is also released, and the evaporation process is extended to (possibly much) smaller final masses. We show that these effects could be observable for black holes produced with a relatively large mass and should therefore be taken into account when simulating micro-black hole events for the experiments planned at the LHC.Comment: 14 pages, 8 figures, extended version of hep-ph/0601243 with new analysis of final products, final version accepted for publication in J. Phys.

    Unveiling Palomar 2: The Most Obscure Globular Cluster in the Outer Halo

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    We present the first color-magnitude study for Palomar 2, a distant and heavily obscured globular cluster near the Galactic anticenter. Our (V,V-I) color-magnitude diagram (CMD), obtained with the UH8K camera at the CFHT, reaches V(lim) = 24 and clearly shows the principal sequences of the cluster, though with substantial overall foreground absorption and differential reddening. The CMD morphology shows a well populated red horizontal branch with a sparser extension to the blue, similar to clusters such as NGC 1261, 1851, or 6229 with metallicities near [Fe/H] = -1.3.Fromanaverageofseveralindicators,weestimatetheforegroundreddeningatE(B−V)=1.24+−0.07andobtainatruedistancemodulus(m−M)0=17.1+−0.3. From an average of several indicators, we estimate the foreground reddening at E(B-V) = 1.24 +- 0.07 and obtain a true distance modulus (m-M)_0 = 17.1 +- 0.3, placing it about 34 kpc from the Galactic center. We use starcounts of the bright stars to measure the core radius, half-mass radius, and central concentration of the cluster. Its integrated luminosity is M_V = -7.9, making it clearly brighter and more massive than most other clusters in the outer halo.Comment: 25 pages, aastex, with 8 postscript figures; accepted for publication in AJ, September 1997. Also available by e-mail from [email protected]. Please consult Harris directly for (big) postscript files of Figures 1a,b (the images of the cluster
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