560 research outputs found

    Early tissue responses in psoriasis to the antitumour necrosis factor‐α biologic etanercept suggest reduced interleukin‐17 receptor expression and signalling

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108076/1/bjd12937-sup-0005-TableS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108076/2/bjd12937-sup-0004-TableS1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108076/3/bjd12937.pd

    Constraining scalar fields with stellar kinematics and collisional dark matter

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    The existence and detection of scalar fields could provide solutions to long-standing puzzles about the nature of dark matter, the dark compact objects at the centre of most galaxies, and other phenomena. Yet, self-interacting scalar fields are very poorly constrained by astronomical observations, leading to great uncertainties in estimates of the mass mϕm_\phi and the self-interacting coupling constant λ\lambda of these fields. To counter this, we have systematically employed available astronomical observations to develop new constraints, considerably restricting this parameter space. In particular, by exploiting precise observations of stellar dynamics at the centre of our Galaxy and assuming that these dynamics can be explained by a single boson star, we determine an upper limit for the boson star compactness and impose significant limits on the values of the properties of possible scalar fields. Requiring the scalar field particle to follow a collisional dark matter model further narrows these constraints. Most importantly, we find that if a scalar dark matter particle does exist, then it cannot account for both the dark-matter halos and the existence of dark compact objects in galactic nucleiComment: 23 pages, 8 figures; accepted for publication by JCAP after minor change

    NGPaaS framework for enriched and customized virtual network functions-as-a-service

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    This paper describes how the novel Next Generation Platform-as-a-Service (NGPaaS) framework can facilitate major benefits for Network Operators and Vertical Service Providers (VSPs) who wish to leverage Virtual Network Functions-as-a-Service (VNFaaS) capabilities. Network Operators can benefit by providing an "on demand" PaaS with required features for the VSPs, thus generating new revenue streams but with low operational overhead due to the high degree of automation. VSPs can benefit from the PaaS-oriented approach, by being able to flexibly on-board new VNF types and "value-added" service capabilities like monitoring, healing and profiling, to deliver customized service blueprints to meet the needs of their end customers. The paper outlines the design of an early prototype, built on the Open-CORD platform and using industry-standard Virtualised Network Functions (VNFs)

    Striatal Acetylcholine Helps to Preserve Functional Outcomes in a Mouse Model of Stroke

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    Acetylcholine (ACh) has been suggested to facilitate plasticity and improve functional recovery after different types of brain lesions. Interestingly, numerous studies have shown that striatal cholinergic interneurons are relatively resistant to acute ischemic insults, but whether ACh released by these neurons enhances functional recovery after stroke is unknown. We investigated the role of endogenous striatal ACh in stroke lesion volume and functional outcomes following middle cerebral artery occlusion to induce focal ischemia in striatum-selective vesicular acetylcholine transporter-deficient mice (stVAChT-KO). As transporter expression is almost completely eliminated in the striatum of stVAChT-KO mice, ACh release is nearly abolished in this area. Conversely, in other brain areas, VAChT expression and ACh release are preserved. Our results demonstrate a larger infarct size after ischemic insult in stVAChT-KO mice, with more pronounced functional impairments and increased mortality than in littermate controls. These changes are associated with increased activation of GSK-3, decreased levels of ÎČ-catenin, and a higher permeability of the blood–brain barrier in mice with loss of VAChT in striatum neurons. These results support a framework in which endogenous ACh secretion originating from cholinergic interneurons in the striatum helps to protect brain tissue against ischemia-induced damage and facilitates brain recovery by supporting blood–brain barrier function

    Gravity-induced Wannier-Stark ladder in an optical lattice

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    We discuss the dynamics of ultracold atoms in an optical potential accelerated by gravity. The positions and widths of the Wannier-Stark ladder of resonances are obtained as metastable states. The metastable Wannier-Bloch states oscillate in a single band with the Bloch period. The width of the resonance gives the rate transition to the continuum.Comment: 5 pages + 8 eps figures, submitted to Phys. Rev.

    Effects of peroxisome proliferator-activated receptor-  activation in endothelin-dependent hypertension

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    Aims We analysed the chronic effects of the peroxisome proliferator-activated receptor ÎČ/ÎŽ (PPAR-ÎČ) agonist GW0742 on the renin-independent hypertension induced by deoxycorticosterone acetate (DOCA)-salt. Methods and results Rats were treated for 5 weeks with: control-vehicle, control-GW0742 (5 or 20 mg kg−1 day−1), DOCA-vehicle, DOCA-GW0742 (5 or 20 mg kg−1 day−1), DOCA-GSK0660 (1 mg kg−1 day−1), and DOCA-GSK0660-GW0742. Rats receiving DOCA-vehicle showed increased systolic blood pressure, left ventricular and kidney weight indices, endothelin-1 (ET-1), and malondialdehyde plasma levels, urinary iso-PGF2α excretion, impaired endothelium-dependent relaxation to acetylcholine, and contraction to ET-1 when compared with controls. Aortic reactive oxygen species content, NADPH oxidase activity, and p47phox, p22phox, NOX-4, glutathione peroxidase 1, hemeoxygenase-1, and preproET-1 expression were increased, whereas catalase and regulators of G protein-coupled signalling proteins (RGS)5 expression were decreased in the DOCA-vehicle group. GW0742 prevented the development of hypertension in a dose-dependent manner but the reduction of renal and cardiac hypertrophy, systemic and vascular oxidative stress markers, and improvement of endothelial dysfunction were only observed after the higher dose. GW0742, at 20 mg kg−1 day−1, attenuated ET-1 contraction by increasing RGS5 expression and restored the intracellular redox balance by reducing NADPH-oxidase activity, and by increasing the antioxidant genes expression. The PPAR-ÎČ antagonist GSK0660 prevented all vascular changes induced by GW0742 but not its antihypertensive effects. Conclusion Vascular protective effects of GW0742 operate via PPAR-ÎČ by interference with the ET-1 signalling as a result of increased expression of RGS5 and up-regulation of antioxidant genes and via PPAR-ÎČ-independent mechanisms to decrease blood pressure

    An Atom Laser Based on Raman Transitions

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    In this paper we present an atom laser scheme using a Raman transition for the output coupling of atoms. A beam of thermal atoms (bosons) in a metastable atomic state ∣1>|1 > are pumped into a multimode atomic cavity. This cavity is coupled through spontaneous emission to a single mode of another cavity for the ground atomic state, ∣2>|2 >. Above a certain threshold pumping rate a large number of atoms, N2N_2, builds up in this single quantum state and transitions to the ground state of the cavity become enhanced by a factor (N2+1)(N_2 + 1). Atoms in this state are then coupled to the outside of the cavity with a Raman transition. This changes the internal state of the atom and imparts a momentum kick, allowing the atoms to leave the system.Comment: 8 pages, 4 postscript figures, uses RevTex, home page at http://online.anu.edu.au/Physics/Welcome.html (Some aspects of the exact physical model have changed from original version. Other general improvements included

    Minimum mass of galaxies from BEC or scalar field dark matter

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    Many problems of cold dark matter models such as the cusp problem and the missing satellite problem can be alleviated, if galactic halo dark matter particles are ultra-light scalar particles and in Bose-Einstein condensate (BEC), thanks to a characteristic length scale of the particles. We show that this finite length scale of the dark matter can also explain the recently observed common central mass of the Milky Way satellites (∌107M⊙\sim 10^7 M_\odot) independent of their luminosity, if the mass of the dark matter particle is about 10−22eV10^{-22} eV.Comment: 10 pages, 1 figure, accepted in JCA

    Input-output theory for fermions in an atom cavity

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    We generalize the quantum optical input-output theory developed for optical cavities to ultracold fermionic atoms confined in a trapping potential, which forms an "atom cavity". In order to account for the Pauli exclusion principle, quantum Langevin equations for all cavity modes are derived. The dissipative part of these multi-mode Langevin equations includes a coupling between cavity modes. We also derive a set of boundary conditions for the Fermi field that relate the output fields to the input fields and the field radiated by the cavity. Starting from a constant uniform current of fermions incident on one side of the cavity, we use the boundary conditions to calculate the occupation numbers and current density for the fermions that are reflected and transmitted by the cavity
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