2,436 research outputs found
On finite-temperature holographic QCD in the Veneziano limit
Holographic models in the T=0 universality class of QCD in the limit of large
number N_c of colors and N_f massless fermion flavors, but constant ratio
x_f=N_f/N_c, are analyzed at finite temperature. The models contain a
5-dimensional metric and two scalars, a dilaton sourcing TrF^2 and a tachyon
dual to \bar qq. The phase structure on the T,x_f plane is computed and various
1st order, 2nd order transitions and crossovers with their chiral symmetry
properties are identified. For each x_f, the temperature dependence of p/T^4
and the quark-antiquark -condensate is computed. In the simplest case, we find
that for x_f up to the critical x_c\sim 4 there is a 1st order transition on
which chiral symmetry is broken and the energy density jumps. In the conformal
window x_c<x_f<11/2, there is only a continuous crossover between two conformal
phases. When approaching x_c from below, x_f\to x_c, temperature scales
approach zero as specified by Miransky scaling.Comment: 66 pages, 29 figure
Pathological Angiogenesis Requires Syndecan-4 for Efficient VEGFA-Induced VE-Cadherin Internalization
Objective:
VEGFA (Vascular endothelial growth factor A) and its receptor VEGFR2 (vascular endothelial growth factor receptor 2) drive angiogenesis in several pathologies, including diabetic retinopathy, wet age-related macular degeneration, and cancer. Studies suggest roles for HSPGs (heparan sulfate proteoglycans) in this process, although the nature of this involvement remains elusive. Here, we set to establish the role of the HSPG SDC4 (syndecan-4) in pathological angiogenesis.
Approach and Results:
We report that angiogenesis is impaired in mice null for SDC4 in models of neovascular eye disease and tumor development. Our work demonstrates that SDC4 is the only SDC whose gene expression is upregulated during pathological angiogenesis and is selectively enriched on immature vessels in retinas from diabetic retinopathy patients. Combining in vivo and tissue culture models, we identified SDC4 as a downstream mediator of functional angiogenic responses to VEGFA. We found that SDC4 resides at endothelial cell junctions, interacts with vascular endothelial cadherin, and is required for its internalization in response to VEGFA. Finally, we show that pathological angiogenic responses are inhibited in a model of wet age-related macular degeneration by targeting SDC4.
Conclusions:
We show that SDC4 is a downstream mediator of VEGFA-induced vascular endothelial cadherin internalization during pathological angiogenesis and a potential target for antiangiogenic therapies
The experience of long-term opiate maintenance treatment and reported barriers to recovery: A qualitative systematic review
Background/Aim: To inform understanding of the experience of long-term opiate maintenance and identify barriers to recovery. Methods: A qualitative systematic review. Results: 14 studies in 17 papers, mainly from the USA (65%), met inclusion criteria, involving 1,088 participants. Studies focused on methadone prescribing. Participants reported stability; however, many disliked methadone. Barriers to full recovery were primarily ‘inward focused'. Conclusion: This is the first review of qualitative literature on long-term maintenance, finding that universal service improvements could be made to address reported barriers to recovery, including involving ex-users as positive role models, and increasing access to psychological support. Treatment policies combining harm minimisation and abstinence-orientated approaches may best support individualised recovery
Lake eutrophication and brownification downgrade availability and transfer of essential fatty acids for human consumption
Fish are an important source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for birds, mammals and humans. In aquatic food webs, these highly unsaturated fatty acids (HUFA) are essential for many physiological processes and mainly synthetized by distinct phytoplankton taxa. Consumers at different trophic levels obtain essential fatty acids from their diet because they cannot produce these sufficiently de novo. Here, we evaluated how the increase in phosphorus concentration (eutrophication) or terrestrial organic matter inputs (brownification) change EPA and DHA content in the phytoplankton. Then, we evaluated whether these changes can be seen in the EPA and DHA content of piscivorous European perch (Perca fluviatilis), which is a widely distributed species and commonly consumed by humans. Data from 713 lakes showed statistically significant differences in the abundance of EPA- and DHA-synthesizing phytoplankton as well as in the concentrations and content of these essential fatty acids among oligo-mesotrophic, eutrophic and dystrophic lakes. The EPA and DHA content of phytoplankton biomass (mg HUFA g(-1)) was significantly lower in the eutrophic lakes than in the oligo-mesotrophic or dystrophic lakes. We found a strong significant correlation between the DHA content in the muscle of piscivorous perch and phytoplankton DHA content (r = 0.85) as well with the contribution of DHA-synthesizing phytoplankton taxa (r = 0.83). Among all DHA-synthesizing phytoplankton this correlation was the strongest with the dinoflagellates (r = 0.74) and chrysophytes (r = 0.70). Accordingly, the EPA + DHA content of perch muscle decreased with increasing total phosphorus (r(2) = 0.80) and dissolved organic carbon concentration (r(2) = 0.83) in the lakes. Our results suggest that although eutrophication generally increase biomass production across different trophic levels, the high proportion of low-quality primary producers reduce EPA and DHA content in the food web up to predatory fish. Ultimately, it seems that lake eutrophication and brownification decrease the nutritional quality of fish for human consumers. (C) 2016 The Authors. Published by Elsevier Ltd.Peer reviewe
A New Mechanism for Generating a Single Transverse Spin Asymmetry
We propose a new mechanism for generating a single transverse spin asymmetry
(STSA) in polarized proton-proton and proton-nucleus collisions in the
high-energy scattering approximation. In this framework the STSA originates
from the q->q G splitting in the projectile (proton) light-cone wave function
followed by a perturbative (C-odd) odderon interaction, together with a C-even
interaction, between the projectile and the target. We show that some aspects
of the obtained expression for the STSA of the produced quarks are in
qualitative agreement with experiment: STSA decreases with decreasing
projectile x_F and is a non-monotonic function of the transverse momentum k_T.
In our framework the STSA peaks at k_T near the saturation scale Q_s. Our
mechanism predicts that the quark STSA in proton-nucleus collisions should be
much smaller than in proton-proton collisions. We also observe that in our
formalism the STSA for prompt photons is zero.Comment: 28 pages, 17 figues; v2: minor corrections, a subsection, discussion
and references added; v3: minor corrections and a new figure added; v4: minor
corrections; v5: minor corrections in figure
Cassini Plasma Spectrometer and hybrid model study on Titan's interaction: Effect of oxygen ions
During the Cassini Titan flyby on 2 July 2006 (T15), Titan was surrounded by a magnetospheric plasma flow with density about 0.1 cm‑3 as measured by Cassini Plasma Spectrometer (CAPS). A very low fraction of water group ions (O+) was detected in the flow dominated by hydrogen ions. We show that Titan's plasma interaction can be highly sensitive to the small fraction of oxygen ions in the magnetospheric flow. The ion quantities of the magnetospheric flow during the flyby were obtained from numerical moments calculated from the CAPS measurements; the average ambient magnetic field was determined using the Cassini magnetometer data. We simulated the flyby using a global hybrid model; the water group abundance in the flow was varied in three simulation runs. Based on the simulation results, the oxygen content has an especially notable effect on the extent of Titan's induced magnetosphere. A multi-instrument analysis was performed comparing with the simulations, whereby a comprehensive picture of the plasma properties around Titan during this flyby was obtained. Comparisons between the hybrid model simulations and Cassini measurements during the flyby point toward O+ density in the undisturbed magnetospheric flow having been around 0.008 cm‑3, which would have accounted for one half of the dynamic pressure of the flow.Fil: Sillanpää, I.. Southwest Research Institute; Estados UnidosFil: Young, D. T.. Southwest Research Institute; Estados UnidosFil: Crary, F.. Southwest Research Institute; Estados UnidosFil: Thomsen, M.. Los Alamos National Laboratory,; Estados UnidosFil: Reisenfelc, D.. University of Montana; Estados UnidosFil: Wahlund, J. E.. Swedish Institute of Space Physics; SueciaFil: Bertucci, Cesar. Consejo Nacional de Investigaciónes CientÃficas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de AstronomÃa y FÃsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomÃa y FÃsica del Espacio; ArgentinaFil: Kallio, E.. Finnish Meteorological Institute,; FinlandiaFil: Jarvinen, R.. Finnish Meteorological Institute; FinlandiaFil: Janhunen, P.. Finnish Meteorological Institute,; Finlandi
Association of 1,5-Anhydroglucitol and 2-h Postprandial Blood Glucose in Type 2 Diabetic Patients
OBJECTIVE—To assess the association of 1,5-anhydroglucitol (1,5-AG) with 2-h postprandial glucose values in type 2 diabetic patients followed over 12 months in an outpatient setting
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