129,705 research outputs found

    [Review of] Constance Wall Holt. Welsh Women: An Annotated Bibliography of Women in Wales and Women of Welch Descent in America

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    To be a Welsh woman, it seems, was to be doubly doomed to obscurity. Not only were women a less-public sector of society, but there was Welshness to contend with. It has been a case of Bibliographic Ethnic Discrimination. Too often entries have read: Women, Welsh, See Women, English. And this occurs in spite of the fact that Welsh, being Celts, are a distinct group with their own language and culture, though they have long been subject to English rule

    On the politics of lapdogs, Jim's dog, and crittercams

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    A three dimensional finite element model of wind effects upon higher harmonics of the internal tide.

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    A non-linear three dimensional unstructured grid model of the M2 tide in the shelf edge area off the west coast of Scotland is used to examine the spatial distribution of the M2 internal tide and its higher harmonics in the region. In addition the spatial variability of the tidally induced turbulent kinetic energy and associated mixing in the area are considered. Initial calculations involve only tidal forcing, although subsequent calculations are performed with up-welling and down-welling favourable winds in order to examine how these influence the tidal distribution (particularly the higher harmonics) and mixing in the region. Both short and long duration winds are used in these calculations. Tidal calculations show that there is significant small scale spatial variability particularly in the higher harmonics of the internal tide in the region. In addition turbulence energy and mixing exhibit appreciable spatial variability in regions of rapidly changing topography, with increased mixing occurring above seamounts. Wind effects significantly change the distribution of the M2 internal tide and its higher harmonics, with appreciable differences found between up- and down-welling winds, and long and short duration winds due to differences in mixing and the presence of wind induced flows. The implications for model validation, particularly in terms of energy transfer to higher harmonics, and mixing are briefly discussed

    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

    Autonomous Locomotion Mode Transition Simulation of a Track-legged Quadruped Robot Step Negotiation

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    Multi-modal locomotion (e.g. terrestrial, aerial, and aquatic) is gaining increasing interest in robotics research as it improves the robots environmental adaptability, locomotion versatility, and operational flexibility. Within the terrestrial multiple locomotion robots, the advantage of hybrid robots stems from their multiple (two or more) locomotion modes, among which robots can select from depending on the encountering terrain conditions. However, there are many challenges in improving the autonomy of the locomotion mode transition between their multiple locomotion modes. This work proposed a method to realize an autonomous locomotion mode transition of a track-legged quadruped robot steps negotiation. The autonomy of the decision-making process was realized by the proposed criterion to comparing energy performances of the rolling and walking locomotion modes. Two climbing gaits were proposed to achieve smooth steps negotiation behaviours for energy evaluation purposes. Simulations showed autonomous locomotion mode transitions were realized for negotiations of steps with different height. The proposed method is generic enough to be utilized to other hybrid robots after some pre-studies of their locomotion energy performances

    Tadpole renormalization and relativistic corrections in lattice NRQCD

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    We make a comparison of two tadpole renormalization schemes in the context of the quarkonium hyperfine splittings in lattice NRQCD. Improved gauge-field and NRQCD actions are analyzed using the mean-link u0,Lu_{0,L} in Landau gauge, and using the fourth root of the average plaquette u0,Pu_{0,P}. Simulations are done for ccˉc\bar c, bcˉb\bar c, and bbˉb\bar b systems. The hyperfine splittings are computed both at leading and at next-to-leading order in the relativistic expansion. Results are obtained at lattice spacings in the range of about 0.14~fm to 0.38~fm. A number of features emerge, all of which favor tadpole renormalization using u0,Lu_{0,L}. This includes much better scaling behavior of the hyperfine splittings in the three quarkonium systems when u0,Lu_{0,L} is used. We also find that relativistic corrections to the spin splittings are smaller when u0,Lu_{0,L} is used, particularly for the ccˉc\bar c and bcˉb\bar c systems. We also see signs of a breakdown in the NRQCD expansion when the bare quark mass falls below about one in lattice units. Simulations with u0,Lu_{0,L} also appear to be better behaved in this context: the bare quark masses turn out to be larger when u0,Lu_{0,L} is used, compared to when u0,Pu_{0,P} is used on lattices with comparable spacings. These results also demonstrate the need to go beyond tree-level tadpole improvement for precision simulations.Comment: 14 pages, 7 figures (minor changes to some phraseology and references

    On eigenfunction approximations for typical non-self-adjoint Schroedinger operators

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    We construct efficient approximations for the eigenfunctions of non-self-adjoint Schroedinger operators in one dimension. The same ideas also apply to the study of resonances of self-adjoint Schroedinger operators which have dilation analytic potentials. In spite of the fact that such eigenfunctions can have surprisingly complicated structures with multiple local maxima, we show that a suitable adaptation of the JWKB method is able to provide accurate lobal approximations to them.Comment: 17 pages, 11 figure
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