5,107 research outputs found
MacromamĂferos (Ă©quidos, bĂłvidos) de la cueva de Praducelos (Suegos, Luego)
[Resumen] En este trabajo se describen restos -Ăłseos: 1 mandibula,l tibia derecha de Equus Cabalus aff.gallicus, y un fragmento de maxilar y otro de base de cuerna de Bos sp.(o Bison sp.), procedentes de la cueva de Praducelos(Suegos,Lugo).[Abstract] the note describe bone rests:one mandibule and one tibia of Equus Cabalus aff. and a maxilar fragment and horn base of Bos sp.( or Bison sp.),from Praducelos, (Suegos,Lugo,Spain)
Propagation and spectral properties of quantum walks in electric fields
We study one-dimensional quantum walks in a homogeneous electric field. The
field is given by a phase which depends linearly on position and is applied
after each step. The long time propagation properties of this system, such as
revivals, ballistic expansion and Anderson localization, depend very
sensitively on the value of the electric field , e.g., on whether
is rational or irrational. We relate these properties to the
continued fraction expansion of the field. When the field is given only with
finite accuracy, the beginning of the expansion allows analogous conclusions
about the behavior on finite time scales.Comment: 7 pages, 4 figure
Multivariate Empirical Mode Decomposition analysis of Swarm data
The magnetosphere and the ionosphere of the Earth are populated by different current systems with well-structured spatial patterns. In this paper, by using low-resolution (1 Hz) Swarm A data, we present an application of the Multivariate Empirical Mode Decomposition (MEMD) to the external variations of the geomagnetic field, allowing us to identify magnetospheric and ionospheric current
systems patterns. By using both quiet and disturbed periods, we show that MEMD is able to clearly discern between magnetospheric and ionospheric contributions,
evidencing magnetospheric ring current pattern, field aligned currents, ionospheric Solar quiet (Sq) and equatorial electrojet (EEJ) currents, with well-defined spatial patterns, in addition to which we observe both short- and large-scale contributions
On fine differentiability properties of horizons and applications to Riemannian geometry
We study fine differentiability properties of horizons. We show that the set
of end points of generators of a n-dimensional horizon H (which is included in
a (n+1)-dimensional space-time M) has vanishing n-dimensional Hausdorff
measure. This is proved by showing that the set of end points of generators at
which the horizon is differentiable has the same property. For 1\le k\le n+1 we
show (using deep results of Alberti) that the set of points where the convex
hull of the set of generators leaving the horizon has dimension k is ``almost a
C^2 manifold of dimension n+1-k'': it can be covered, up to a set of vanishing
(n+1-k)-dimensional Hausdorff measure, by a countable number of C^2 manifolds.
We use our Lorentzian geometry results to derive information about the fine
differentiability properties of the distance function and the structure of cut
loci in Riemannian geometry.Comment: Latex2e, 13 pages in A4 forma
Fidelity and Concurrence of conjugated states
We prove some new properties of fidelity (transition probability) and
concurrence, the latter defined by straightforward extension of Wootters
notation. Choose a conjugation and consider the dependence of fidelity or of
concurrence on conjugated pairs of density operators. These functions turn out
to be concave or convex roofs. Optimal decompositions are constructed. Some
applications to two- and tripartite systems illustrate the general theorem.Comment: 10 pages, RevTex, Correction: Enlarged, reorganized version. More
explanation
Revealing the reality of undergraduate GP teaching in UK medical curricula: a cross-sectional questionnaire study
BACKGROUND: Time in general practice offers medical students opportunities to learn a breadth of clinical knowledge and skills relevant to their future clinical practice. Undergraduate experiences shape career decisions and current recommendations are that 25% of undergraduate curriculum time should be focused on general practice. However, previous work demonstrated that GP teaching had plateaued or reduced in UK medical schools. Therefore, an up-to-date description of undergraduate GP teaching is timely. AIM: To describe the current picture of UK undergraduate GP teaching, including the amount of time and resources allocated to GP teaching. DESIGN AND SETTING: A cross-sectional questionnaire study across 36 UK medical schools. METHOD: The questionnaire was designed based on a previous survey performed in 2011–2013, with additional questions on human and financial support allocated to GP teaching. The questionnaire was piloted and revised prior to distribution to leads of undergraduate GP teaching in UK medical schools. RESULTS: The questionnaire response rate was 100%. GP teaching constituted an average of 9.2% of medical curricula; this was lower than previous figures, though the actual number of GP sessions has remained static. The majority (n = 23) describe plans to increase GP teaching in their local curricula over the next 5 years. UK-wide average payment was 55.60 GBP/student/session of in-practice teaching, falling well below estimated costs to practices. Allocation of human resources was varied. CONCLUSION: Undergraduate GP teaching provision has plateaued since 2000 and falls short of national recommendations. Chronic underinvestment in GP teaching persists at a time when teaching is expected to increase. Both aspects need to be addressed to facilitate high-quality undergraduate GP teaching and promotion of the expert medical generalist role
Trace fossils of an amalgamated storm-bed succession from the Jurassic of the Kachchh Basin, India : the significance of time-averaging in ichnology
The uppermost part of the Upper Bathonian Sponge Limestone member, Patcham Formation, of the Jhura Dome of Kachchh Mainland is a thickening- and shallowing-upward succession topped by medium- to thick-bedded hummocky cross-stratified grainstones deposited by storm waves. Occasionally, thin, commonly lenticular, intraclastic–bioclastic silty marl intercalations between the grainstones are highly bioturbated, in contrast to the grainstones, in which, for the most part, trace fossils occur scattered. Large exposures of bedding planes of the grainstones allow the detailed investigation of ichnological features, whereas the high density of traces in the soft marls precludes the identification of any ichnotaxa. Eighteen ichnotaxa have been recorded including Ophiomorpha, Thalassinoides, Taenidium, Gyrophyllites, Chondrites, Dactyloidites, Teichichnus, Bolonia, and Ancorichnus. Except for Ophiomorpha nodosa and Thalassinoides, which generally indicate moderate to high energy conditions and are the dwelling burrows of suspension-feeding to omnivorous crustaceans, the ichnotaxa represent a deposit-feeding behaviour of their producers and thus are characteristic of low-energy environments. The trace fossils form three ichnoassemblages characterized by (1) Ophiomorpha nodosa and Thalassinoides suevicus, (2) ?Thalassinoides isp. A, Taenidium, and Bolonia lata, and (3) Ancorichnus. The dominance of traces of deposit-feeders in rocks indicative of high-energy events is counterintuitive and points to their non-contemporaneity. The sediments were deposited during brief high-energy events, whereas the trace fossils were produced when, after waning of storms low-energy conditions prevailed. This time-averaging is particularly pronounced in trace fossils that extend vertically downwards and may reach strata deposited under distinctly different conditions. Thus, environmental interpretations based on trace fossils should refer to colonisation surfaces rather than to the sediment surrounding the trace fossils. In the latter case, interpretations may be erroneous, especially when erosion subsequently destroyed sedimentary evidence of their original environment
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