3,316 research outputs found
Combination of magnesium sulphate and ropivacaine epidural analgesia for hip arthroplasty in dogs
The aim of this study was to determine
whether lumbosacral epidural administration of
magnesium sulphate added to ropivacaine prolongs
and improves perioperative analgesia,
without adverse effects on motor block duration or
hind limb neurological function, in dogs undergoing
hip arthroplast
The cluster Abell 780: an optical view
The Abell 780 cluster, better known as the Hydra A cluster, has been
thouroughly analyzed in X-rays. However, little is known on its optical
properties. We derive the galaxy luminosity function (GLF) in this apparently
relaxed cluster, and search for possible environmental effects by comparing the
GLFs in various regions, and by looking at the galaxy distribution at large
scale around Abell 780. Our study is based on optical images obtained with the
ESO 2.2m telescope and WFI camera in the B and R bands, covering a total region
of 67.22x32.94 arcmin^2, or 4.235x2.075 Mpc^2 for a cluster redshift of 0.0539.
In a region of 500 kpc radius around the cluster centre, the GLF in the R band
shows a double structure, with a broad and flat bright part and a flat faint
end that can be fit by a power law with an index alpha=-0.85+-0.12 in the
20.25<R<21.75 interval. If we divide this 500 kpc radius region in North+South
or East+West halves, we find no clear difference between the GLFs in these
smaller regions. No obvious large scale structure is apparent within 5 Mpc from
the cluster, based on galaxy redshifts and magnitudes collected from the NED
database in a much larger region than that covered by our data, suggesting that
there is no major infall of material in any preferential direction. However,
the Serna-Gerbal method reveals the presence of a gravitationally bound
structure of 27 galaxies, which includes the cD, and of a more strongly
gravitationally bound structure of 14 galaxies. These optical results agree
with the overall relaxed structure of Abell 780 previously derived from X-ray
analyses.Comment: Accepted for publication in Astronomy & Astrophysic
Multimodality and superdiversity: evidence for a research agenda
In recent years, social science research in superdiversity has questioned notions such as multiculturalism and pluralism, which hinge on and de facto reproduce ideological constructs such as separate and clearly identifiable national cultures and ethnic identities; research in language and superdiversity, in translanguaging, polylanguaging and metrolingualism have analogously questioned concepts such as multi- and bi-lingualism, which hinge on ideological constructs such as national languages, mother tongue and native speaker proficiency. Research in multimodality has questioned the centrality of language in everyday communication as well as its paradigmatic role to the understanding of communicative practices. While the multimodality of communication is generally acknowledged in work on language and superdiversity, the potential of a social semiotic multimodal approach for understanding communication in superdiversity has not been adequately explored and developed yet – and neither has the concept of superdiversity been addressed in multimodal research. The present paper wants to start to fill this gap. By discussing sign-making practices in the superdiverse context of Leeds Kirkgate Market (UK), it maps the potentials of an ethnographic social semiotics for the study of communication in superdiversity and sketches an agenda for research on multimodality and superdiversity, identifying a series of working hypotheses, research questions, areas of investigations and domains and fields of enquiry
Shaping the Social Through the Aesthetics of Public Places: The Renovation of Leeds Kirkgate Market
This chapter shows how social semiotic multimodal analysis can contribute to understanding the social dynamics beyond, and reflected by, the regulatory practices shaping the aesthetics of the visual landscapes of public spaces. The visual and material landscape of our urban environments has semiotic and social significance. The chapter examines the case of Kirkgate Market, in Leeds (UK), focusing on the changes in sign-making practices deriving from the undergoing renovation of the place, which is affected by increasing semiotic regulation in the institution's attempts to brand its image. It provides background information on Kirkgate Market. The chapter then introduces the semiotically unregulated character of the place before it underwent renovation, and analyses the changes in its visual landscape following renovation. It concludes by identifying the gains and losses produced in the change, in terms of semiotic practices and related social effects
Styling the self online: semiotic technologization in weblog publishing
Testing on digital semiotic production the concepts of (self-)styling and technologization of discourse, developed for offline linguistic phenomena, the article investigates the role of digital platforms in shaping the relation between self-expression online, semiotic regulation and the social construction of taste. By focusing on the use of semiotic resources of webdesign for identity expression, the study analyses the semiotic regimes emerging from regulatory practices and webdesign styles on WordPress, and their influence on the changes in the projected identity of a personal blogger. In spite of the participatory character of WordPress, results show the role of the platform in objectifying/technologizing hegemonic semiotic preferences, with consequent normalising effects in bloggers’ self-styling practices. The conclusions relate the findings to broader power dynamics in the social construction of taste and their implications for both online and offline forms of self-expression
A Wideband, Four-Element, All-Digital Beamforming System for Dense Aperture Arrays in Radio Astronomy
Densely-packed, all-digital aperture arrays form a key area of technology
development required for the Square Kilometre Array (SKA) radio telescope. The
design of real-time signal processing systems for digital aperture arrays is
currently a central challenge in pathfinder projects worldwide. We describe
interim results of such work; an heirarchical, frequency-domain beamforming
architecture for synthesising a sky beam from the wideband antenna feeds of
digital aperture arrays.Comment: 4 pages, 6 figure
A Possible Case of Neurogenic Pulmonary Edema in a Sheep following Intracranial Surgery
A 3-year-old female crossbred sheep weighing 64 kg was anaesthetized for intracranial surgery as a part of a research project. Premedication and induction of anesthesia were uneventful as well as tracheal intubation. Anesthesia was maintained with isoflurane in a 50% mixture of oxygen and air, fentanyl (5-15 µg kg-1h-1) and lidocaine (1.8 mg kg-1h-1). During anesthesia, an increased alveolar-arterial oxygen gradient was calculated on the basis of arterial blood gas analysis: inspiratory fraction of oxygen was increased and a recruitment manoeuvre was performed. After 210 minutes of anesthesia, the sheep was let recover with oxygen supplementation under monitoring of pulse-oxymetry, capnography, inspired and expired oxygen, temperature and invasive blood pressure. At tracheal extubation no signs of regurgitation or aspiration were noticed. Twenty-five minutes later, the sheep showed deterioration of neurological status and clonic seizure responsive to diazepam. After transient tachycardia, blood pressure rose acutely and sinus bradycardia followed. Severe tachypnea started in few minutes accompanied by loud respiratory noises and harsh diffuse crackles on both sides of the thorax. Foamy blood nasal exudates discharged from the nostrils. Neurogenic pulmonary edema as a sequel of increased intracranial pressure was suspected and treated with intravenous mannitol (0.5 gkg-1) and furosemide (4 mgKg-1). Hypoxemia was successfully managed with oxygen supplementation. Motor and cognitive functions improved progressively and were deemed normal within 12 hours from the episode, when arterial partial pressure of oxygen was 11.7 kPa (88 mmHg) at room air
Stability and symmetry-breaking bifurcation for the ground states of a NLS with a interaction
We determine and study the ground states of a focusing Schr\"odinger equation
in dimension one with a power nonlinearity and a strong
inhomogeneity represented by a singular point perturbation, the so-called
(attractive) interaction, located at the origin. The
time-dependent problem turns out to be globally well posed in the subcritical
regime, and locally well posed in the supercritical and critical regime in the
appropriate energy space. The set of the (nonlinear) ground states is
completely determined. For any value of the nonlinearity power, it exhibits a
symmetry breaking bifurcation structure as a function of the frequency (i.e.,
the nonlinear eigenvalue) . More precisely, there exists a critical
value \om^* of the nonlinear eigenvalue \om, such that: if \om_0 < \om <
\om^*, then there is a single ground state and it is an odd function; if \om
> \om^* then there exist two non-symmetric ground states. We prove that before
bifurcation (i.e., for \om < \om^*) and for any subcritical power, every
ground state is orbitally stable. After bifurcation (\om =\om^*+0), ground
states are stable if does not exceed a value that lies
between 2 and 2.5, and become unstable for . Finally, for and \om \gg \om^*, all ground states are unstable. The branch of odd
ground states for \om \om^*,
obtaining a family of orbitally unstable stationary states. Existence of ground
states is proved by variational techniques, and the stability properties of
stationary states are investigated by means of the Grillakis-Shatah-Strauss
framework, where some non standard techniques have to be used to establish the
needed properties of linearization operators.Comment: 46 pages, 5 figure
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