137,620 research outputs found
Book Review of "Molecular Mechanisms of Parasite Invasion" by Barbara A.Burleigh and Dominique Soldati-Favre
Book review of "Molecular Mechanisms of Parasite Invasion" by Barbara A. Burleigh and Dominique Soldati-Favr
A note on the motion of an ocean bacterium in a linear shear flow
This paper treats a simple model, which can be exactly solved, motivated by the back-and-forth motion of ocean bacteria. In particular, the probability is determined that a bacterium moving randomly along a fluid line through the origin in a linear shear flow hits the origin before time
Bi-algebras, generalised geometry and T-duality
A study of sigma models whose target space is a group G that admits a
compatible Poisson structure is presented. The natural action of O(D,D;Z) on
the generalised tangent bundle TG+T*G and a generalisation of the Courant
bracket that appears are reviewed. This background provides a concrete example
where the generalised geometry and doubled geometry descriptions are both well
understood. Connections between the two formalisms are discussed and the
world-sheet theory from Hamiltonian and Lagrangian perspectives is
investigated. The comparisons between the approaches given by generalised
geometry and doubled geometry suggest possible ways of generalising the
analysis beyond the known examples.Comment: 43 page
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Characterizing the epoch of reionization with the small-scale CMB: Constraints on the optical depth and duration
Patchy reionization leaves a number of imprints on the small-scale cosmic microwave background (CMB) temperature fluctuations, the largest of which is the kinematic Sunyaev-Zel'dovich (kSZ), the Doppler shift of CMB photons scattering off moving electrons in ionized bubbles. It has long been known that in the CMB power spectrum, this imprint of reionization is largely degenerate with the kSZ signal produced by late-time galaxies and clusters, thus limiting our ability to constrain reionization. Following Smith & Ferraro (2017), it is possible to isolate the reionization contribution in a model independent way, by looking at the large scale modulation of the small scale CMB power spectrum. In this paper we extend the formalism to use the full shape information of the small scale power spectrum (rather than just its broadband average), and argue that this is necessary to break the degeneracy between the optical depth τ and parameters setting the duration of reionization. In particular, we show that the next generation of CMB experiments could achieve up to a factor of 3 improvement on the optical depth τ and at the same time, constrain the duration of reionization to ∼25%. This can help tighten the constrains on neutrino masses, which will be limited by our knowledge of τ, and shed light on the physical processes responsible for reionization
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Feline vestibular disorders. Part II: diagnostic approach and differential diagnosis.
Results of a neurological examination usually permit localisation of a vestibular disorder to either the central or peripheral parts of the vestibular system. Many different disorders located in the same part of the vestibular system will produce similar clinical signs. Therefore, additional diagnostic tests beyond a neurological examination are required in order to make an accurate diagnosis. The objectives of this review are to outline a diagnostic approach for disorders affecting the feline vestibular system, and to summarise the clinically important features of frequently diagnosed diseases affecting the vestibular system of cats
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