On the existence and evolution of a spanwise vortex in laminar shallow water dipoles

The present work investigates the existence and evolution of a spanwise vortex at the front of shallow dipolar vortices. The vortex dipoles are experimentally generated using a double flap apparatus. Particle image velocimetry measurements are performed in a horizontal plane and in the vertical symmetry plane of the flow. The dynamics of such vortical structures is investigated through a parametric study in which both the Reynolds number Re=U0D0/ν∈[90,470] and the aspect ratio α = h/D0∈[0.075,0.7],associated with the shallowness of the flow, are varied, where U0 is the initial velocity of the vortex dipole, D0 is the initial diameter, h is the water depth, and v is the kinematic viscosity of the fluid. The present experiments confirm the numerical results obtained in a companion paper by Duran-Matute et al. [Phys. Fluids 22, 116606 (2010)], namely that the flow remains quasi parallel with negligible vertical motions below a critical value of the parameter α2Re. By contrast, for large values of α2Re and α≲0.6, a three-dimensional regime is observed in the shape of an intense spanwise vortex generated at the front of the dipole. The present study reveals that the early-time motion and dynamics of the spanwise vortex do not scale on the unique parameter α2Re but is strongly influenced by both the aspect ratio and the Reynolds number. A mechanism for the generation of the spanwise vortex is proposed. For α≳0.6, a third regime is observed, where the spanwise vortex is replaced by a vorticity tongu

Politics and History experience

¿Cómo pensar la historia más allá de la tradición hegeliano-marxista y al mismo tiempo contra la perspectiva contingencialista? El presente artículo buscará responder a esta pregunta a través de un recorrido por la obra de Merleau-Ponty, focalizando en la imbricación entre lo político y lo histórico a partir de una filosofía de la carne y una teoría política de la acción. Para ello, intentaremos enhebrar el hilo conceptual que dibuja la relación entre lo histórico y lo político a partir de la lectura merleau-pontyana de Max Weber y Georg Lukács, porque sólo a través de ella podremos entrever el surco que trazó Merleau-Ponty a fin de eludir las trampas del materialismo histórico (sin necesidad de renunciar a Marx), los restos dispersos del hegelianismo y, en suma, la idea de Historia como teología secularizada. En síntesis: la intelección de ese surco que cruza lo político con la experiencia de la historia será el objetivo central del presente artículo.How to think History beyond Marxist tradition and at the same time against contingency perspective? This article will attempt to answer this question focusing on Merleau-Ponty’s work; particularly, on the overlap between the political and the historical, as regarded by a Philosophy of “Flesh” and a Political Theory of action. For this, we will follow the conceptual thread that draws the relationship between the historical and political from merleau-pontian reading of Max Weber and Georg Lukacs, because it is only through it that can we glimpse the furrow delineated by Merleau-Ponty to avoid the pitfalls of historical materialism (without having to renounce to Marx), the scattered remnants of hegelianism and the idea of History as secularized theology. In synthesis: the intelección of this groove that crosses the political with the experience of the history will be the central aim of the present article.Fil: Eiff, Leonardo Daniel. Universidad Nacional de General Sarmiento. Instituto del Desarrollo Humano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Comprehending Amma: The Influence of Linguistic Ideology Upon A Contemporary Godperson

This paper examines the significance of differing linguistic ideologies present within the international religious following of contemporary Indian godperson, Sri Mata Amritanandamayi Devi. With particular reference to A.K. Ramanujan’s discussion of speech typical to Indian and American individuals, it argues that the varying linguistic ideologies present within this linguistically diverse community inform contesting worldviews that are manifested in equally contesting perceptions of their spiritual leader; thus, bringing about different ways in which She is engaged

Fatal case due to methicillin-resistant Staphylococcus aureus small colony variants in an AIDS patient.

We describe the first known case of a fatal infection with small colony variants of methicillin-resistant Staphylococcus aureus in a patient with AIDS. Recovered from three blood cultures as well as from a deep hip abscess, these variants may have resulted from long-term antimicrobial therapy with trimethoprim/sulfamethoxazole for prophylaxis of Pneumocystis carinii pneumonia

Fine‐Sediment Erosion and Sediment‐Ribbon Morphodynamics in Coarse‐Grained Immobile Beds

In rivers, fine sediments are often transported over immobile coarse grains. With low sediment supply, they tend to aggregate in longitudinal ribbons. Yet, the long-term evolution of such ribbons and the influence of immobile grains on the erosion of fine sediments are still not well understood. Flume experiments without sediment supply were therefore performed to investigate the erosion of an initially uniform fine-sediment bed covering an immobile bed of staggered spheres through topographic and flow measurements. The topographic measurements yielded the spheres\u27 protrusion above the fine sediment (P) and revealed long-lived ribbons with ridges and troughs. The ridges are the main long-term sediment source as the troughs are quickly eroded to a stable bed level resulting from the spheres\u27 sheltering. The ridges stabilize with a spacing of 1.3 effective water depths, their number resulting from the integer number of wavelengths fitting into the effective channel width which excludes side-wall accumulations. The ridges\u27 erosion is damped by the local upflow of secondary current cells, which displaces the strongest sweep events above the bed. The upflow intensity is controlled by the ridges\u27 height for low P, while for high P by the lateral roughness heterogeneity. The trends in erosion rates over ridges and troughs are similar and characterized by the following sequence of four regimes with increasing P: a drag sheltering, a turbulence-enhancement, a wake-interference sheltering, and a skimming-flow sheltering regime. The critical P levels at the transitions are independent of the flow above the canopy, depending only on the geometrical configuration of the immobile bed

The power of low-resolution spectroscopy: On the spectral classification of planet candidates in the ground-based CoRoT follow-up

Planetary transits detected by the CoRoT mission can be mimicked by a low-mass star in orbit around a giant star. Spectral classification helps to identify the giant stars and also early-type stars which are often excluded from further follow-up. We study the potential and the limitations of low-resolution spectroscopy to improve the photometric spectral types of CoRoT candidates. In particular, we want to study the influence of the signal-to-noise ratio (SNR) of the target spectrum in a quantitative way. We built an own template library and investigate whether a template library from the literature is able to reproduce the classifications. Including previous photometric estimates, we show how the additional spectroscopic information improves the constraints on spectral type. Low-resolution spectroscopy ($R\approx$1000) of 42 CoRoT targets covering a wide range in SNR (1-437) and of 149 templates was obtained in 2012-2013 with the Nasmyth spectrograph at the Tautenburg 2m telescope. Spectral types have been derived automatically by comparing with the observed template spectra. The classification has been repeated with the external CFLIB library. The spectral class obtained with the external library agrees within a few sub-classes when the target spectrum has a SNR of about 100 at least. While the photometric spectral type can deviate by an entire spectral class, the photometric luminosity classification is as close as a spectroscopic classification with the external library. A low SNR of the target spectrum limits the attainable accuracy of classification more strongly than the use of external templates or photometry. Furthermore we found that low-resolution reconnaissance spectroscopy ensures that good planet candidates are kept that would otherwise be discarded based on photometric spectral type alone.Comment: accepted for publication in Astronomische Nachrichten; 12 pages, 4 figures, 7 table

Making God\u27s Love Manifest : American Expressions and Productions of Charisma in Sri Mata Amritanandamayi Devi\u27s Global Following

While situating it in a changing American religious landscape marked by increasing participation in metaphysical religion, this dissertation examines the appeal of contemporary Indian godperson, Sri Mata Amritanandamayi Devi (Amma), to Americans. Although replete with portraits of individual Indian spiritual leaders’ charisma, the anthropology of religion literature seldom addresses the processes whereby such figures’ charisma gets produced. Drawing on thirteen months of multi-sited ethnographic research conducted between 2015-2016, this dissertation uses Max Weber’s theory of charisma to answer the following questions: what extraordinary capacity do American devotees attribute to Amma; what is the process whereby they and she co-produce this particular expression of her charisma; and what is the role of seva (selfless service) in this process? Three key findings resulted from this study. First, over the course of their progression through what I identify as the “admirer,” “initiate,” “ashramite,” and “renunciate” stages the American Devotee Life Cycle, American devotees modify their seva practices to perform them on behalf of a wider variety of beneficiaries in a wider variety of contexts as well as in more of an ongoing manner. Second, American devotees attribute to Amma the extraordinary capacity to transform people. By this, I mean the extraordinary capacity to encourage spiritual seekers not only to understand themselves and the world in which they live but also to act in that world according to what I term a “sevite habitus” informed by the spiritual truth that all are essentially one. According to American devotees, such is “god’s love,” which Amma makes manifest in them - by virtue of her necessarily transformative divine powers, or “grace” - in the form of a desire to perform seva practices on behalf of all always. This is Amma’s charisma and the reason for her appeal to Americans. Third, the process whereby Amma’s charisma gets produced is collaborative. Motivated by proxemic desire, American devotees pursue opportunities to be near Amma. These include opportunities to perform seva practices in her presence. Upon interpreting praising and scolding behaviors that Amma displays as guidance to do so, American devotees diversify their seva practices. They also perform their seva practices more frequently. As a result, they perform the transforming personhoods that they attribute to Amma. Together, these findings contribute to the anthropology of religion literature on charismatic Indian spiritual leaders by illustrating the role that spiritual seekers play in the construction of the power that such figures wield in the material world

Relativistic Mean Field Calculations of Λ\Lambda and Σ\Sigma Hypernuclei

Single--particle spectra of $\Lambda$ and $\Sigma$ hypernuclei are calculated within a relativistic mean--field theory. The hyperon couplings used are compatible with the $\Lambda$ binding in saturated nuclear matter, neutron-star masses and experimental data on $\Lambda$ levels in hypernuclei. Special attention is devoted to the spin-orbit potential for the hyperons and the influence of the $\rho$-meson field (isospin dependent interaction).Comment: 18 pages, including 2 figs., figs. 1 and 4-6 available as postscript-datasets on request; written in Latex, report# LBL-3303

Nuclear surface properties in relativistic effective field theory

We perform Hartree calculations of symmetric and asymmetric semi-infinite nuclear matter in the framework of relativistic models based on effective hadronic field theories as recently proposed in the literature. In addition to the conventional cubic and quartic scalar self-interactions, the extended models incorporate a quartic vector self-interaction, scalar-vector non-linearities and tensor couplings of the vector mesons. We investigate the implications of these terms on nuclear surface properties such as the surface energy coefficient, surface thickness, surface stiffness coefficient, neutron skin thickness and the spin-orbit force.Comment: 30 pages, 15 figures. Submitted to Nuclear Physics