336 research outputs found
Quality Difference in Craniofacial Pain of Cardiac vs. Dental Origin
Craniofacial pain, whether odontogenic or caused by cardiac ischemia, is commonly referred to the same locations, posing a diagnostic challenge. We hypothesized that the validity of pain characteristics would be high in assessment of differential diagnosis. Pain quality, intensity, and gender characteristics were assessed for referred craniofacial pain from dental (n = 359) vs. cardiac (n = 115) origin. The pain descriptors “pressure” and “burning”
were statistically associated with pain from cardiac origin, while “throbbing” and “aching” indicated an odontogenic cause. No gender differences were found. These data should now be added to those craniofacial pain characteristics already known to point to acute cardiac disease rather than dental pathology, i.e., pain provocation/aggravation by physical activity, pain relief at rest, and bilateralism. To initiate prompt and appropriate
treatment, dental and medical clinicians as well as the public should be alert to those clinical characteristics of craniofacial pain of cardiac origin
Mode Shift to Arlanda Airport for Sustainable Development
For the past 20 years, the GPCRDB (G protein-coupled receptors database; http://www.gpcr.org/7tm/) has been a 'one-stop shop' for G protein-coupled receptor (GPCR)-related data. The GPCRDB contains experimental data on sequences, ligand-binding constants, mutations and oligomers, as well as many different types of computationally derived data, such as multiple sequence alignments and homology models. The GPCRDB also provides visualization and analysis tools, plus a number of query systems. In the latest GPCRDB release, all multiple sequence alignments, and >65,000 homology models, have been significantly improved, thanks to a recent flurry of GPCR X-ray structure data. Tools were introduced to browse X-ray structures, compare binding sites, profile similar receptors and generate amino acid conservation statistics. Snake plots and helix box diagrams can now be custom coloured (e.g. by chemical properties or mutation data) and saved as figures. A series of sequence alignment visualization tools has been added, and sequence alignments can now be created for subsets of sequences and sequence positions, and alignment statistics can be produced for any of these subsets
Schild's Null Strings in Flat and Curved Backgrounds
Schild's null (tensionless) strings are discussed in certain flat and curved
backgrounds. We find closed, stationary, null strings as natural configurations
existing on the horizons of spacetimes which possess such null hypersurfaces.
Examples of these are obtained in Schwarzschild and Rindler spacetimes. A
dynamic null string is also identified in Rindler spacetime. Furthermore, a
general prescription (with explicit examples) is outlined by means of which
null string configurations can be obtained in a large class of cosmological
backgrounds.Comment: RevTex 3.0, 14 Pages, no figure
Identification of the first surrogate agonists for the G protein-coupled receptor GPR132
We report the first pharmacological tool agonist for in vitro characterization of the orphan receptor GPR132, preliminary structure–activity relationships based on 32 analogs and a suggested binding mode from docking.M.A.S. was supported by a research scholarship from the
Drug Research Academy and Novo Nordisk A/S. D.E.G.
and H.B.-O. gratefully acknowledge financial support by
the Carlsberg Foundation. D.E.G. and D.S.P. gratefully
acknowledges financial support by the Lundbeck
Foundation. Nils Nyberg is acknowledged for help with
NMR spectroscopy. NMR equipment used in this work
was purchased via a grant from The Lundbeck
Foundation (R77-A6742).This is the accepted manuscript. The final version is available at http://pubs.rsc.org/en/Content/ArticleLanding/2015/RA/c5ra04804d#!divAbstract
Effective dynamics of an electrically charged string with a current
Equations of motion for an electrically charged string with a current in an
external electromagnetic field with regard to the first correction due to the
self-action are derived. It is shown that the reparametrization invariance of
the free action of the string imposes constraints on the possible form of the
current. The effective equations of motion are obtained for an absolutely
elastic charged string in the form of a ring (circle). Equations for the
external electromagnetic fields that admit stationary states of such a ring are
revealed. Solutions to the effective equations of motion of an absolutely
elastic charged ring in the absence of external fields as well as in an
external uniform magnetic field are obtained. In the latter case, the frequency
at which one can observe radiation emitted by the ring is evaluated. A model of
an absolutely nonstretchable charged string with a current is proposed. The
effective equations of motion are derived within this model, and a class of
solutions to these equations is found.Comment: 14 pages, 3 figures, format changed, minor change
Fermionic Coset, Critical Level W^(2)_4-Algebra and Higher Spins
The fermionic coset is a limit of the pure spinor formulation of the AdS5xS5
sigma model as well as a limit of a nonlinear topological A-model, introduced
by Berkovits. We study the latter, especially its symmetries, and map them to
higher spin algebras.
We show the following. The linear A-model possesses affine
\AKMSA{pgl}{4}{4}_0 symmetry at critical level and its \AKMSA{psl}{4}{4}_0
current-current perturbation is the nonlinear model. We find that the
perturbation preserves -algebra symmetry at critical
level. There is a topological algebra associated to \AKMSA{pgl}{4}{4}_0 with
the properties that the perturbation is BRST-exact. Further, the
BRST-cohomology contains world-sheet supersymmetric symplectic fermions and the
non-trivial generators of the -algebra. The Zhu functor
maps the linear model to a higher spin theory. We analyze its
\SLSA{psl}{4}{4} action and find finite dimensional short multiplets.Comment: 25 page
An Infinite Dimensional Symmetry Algebra in String Theory
Symmetry transformations of the space-time fields of string theory are
generated by certain similarity transformations of the stress-tensor of the
associated conformal field theories. This observation is complicated by the
fact that, as we explain, many of the operators we habitually use in string
theory (such as vertices and currents) have ill-defined commutators. However,
we identify an infinite-dimensional subalgebra whose commutators are not
singular, and explicitly calculate its structure constants. This constitutes a
subalgebra of the gauge symmetry of string theory, although it may act on
auxiliary as well as propagating fields. We term this object a {\it weighted
tensor algebra}, and, while it appears to be a distant cousin of the
-algebras, it has not, to our knowledge, appeared in the literature before.Comment: 14 pages, Plain TeX, report RU93-8, CTP-TAMU-2/94, CERN-TH.7022/9
Quaternary structure of a G-protein coupled receptor heterotetramer in complex with Gi and Gs
Background: G-protein-coupled receptors (GPCRs), in the form of monomers or homodimers that bind heterotrimeric G proteins, are fundamental in the transfer of extracellular stimuli to intracellular signaling pathways. Different GPCRs may also interact to form heteromers that are novel signaling units. Despite the exponential growth in the number of solved GPCR crystal structures, the structural properties of heteromers remain unknown. Results: We used single-particle tracking experiments in cells expressing functional adenosine A1-A2A receptors fused to fluorescent proteins to show the loss of Brownian movement of the A1 receptor in the presence of the A2A receptor, and a preponderance of cell surface 2:2 receptor heteromers (dimer of dimers). Using computer modeling, aided by bioluminescence resonance energy transfer assays to monitor receptor homomerization and heteromerization and G-protein coupling, we predict the interacting interfaces and propose a quaternary structure of the GPCR tetramer in complex with two G proteins. Conclusions: The combination of results points to a molecular architecture formed by a rhombus-shaped heterotetramer, which is bound to two different interacting heterotrimeric G proteins (Gi and Gs). These novel results constitute an important advance in understanding the molecular intricacies involved in GPCR function
Ordinary-derivative formulation of conformal totally symmetric arbitrary spin bosonic fields
Conformal totally symmetric arbitrary spin bosonic fields in flat space-time
of even dimension greater than or equal to four are studied. Second-derivative
(ordinary-derivative) formulation for such fields is developed. We obtain gauge
invariant Lagrangian and the corresponding gauge transformations. Gauge
symmetries are realized by involving the Stueckelberg and auxiliary fields.
Realization of global conformal boost symmetries on conformal gauge fields is
obtained. Modified de Donder gauge condition and de Donder-Stueckelberg gauge
condition are introduced. Using the de Donder-Stueckelberg gauge frame,
equivalence of the ordinary-derivative and higher-derivative approaches is
demonstrated. On-shell degrees of freedom of the arbitrary spin conformal field
are analyzed. Ordinary-derivative light-cone gauge Lagrangian of conformal
fields is also presented. Interrelations between the ordinary-derivative gauge
invariant formulation of conformal fields and the gauge invariant formulation
of massive fields are discussed.Comment: 51 pages, v2: Results and conclusions of v1 unchanged. In Sec.3,
brief review of higher-derivative approaches added. In Sec.4, new
representations for Lagrangian, modified de Donder gauge, and de
Donder-Stueckelberg gauge added. In Sec.5, discussion of interrelations
between the ordinary-derivative and higher-derivative approaches added.
Appendices A,B,C,D and references adde
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The orphan G protein-coupled receptor GPR139 is activated by the peptides: adrenocorticotropic hormone (ACTH), α-, and β-melanocyte stimulating hormone (α-MSH, and β-MSH), and the conserved core motif HFRW
GPR139 is an orphan G protein-coupled receptor that is expressed primarily in the brain. Not much is known regarding the function of GPR139. Recently we have shown that GPR139 is activated by the amino acids L-tryptophan and L-phenylalanine (EC50 values of 220 μM and 320 μM, respectively), as well as di-peptides comprised of aromatic amino acids. This led us to hypothesize that GPR139 may be activated by peptides. Sequence alignment of the binding cavities of all class A GPCRs, revealed that the binding pocket of the melanocortin 4 receptor is similar to that of GPR139. Based on the chemogenomics principle "similar targets bind similar ligands”, we tested three known endogenous melanocortin 4 receptor agonists; adrenocorticotropic hormone (ACTH) and α- and β-melanocyte stimulating hormone (α-MSH and β-MSH) on CHO-k1 cells stably expressing the human GPR139 in a Fluo-4 Ca2+-assay. All three peptides, as well as their conserved core motif HFRW, were found to activate GPR139 in the low μM range. Moreover, we found that peptides consisting of nine or ten N-terminal residues of α-MSH activate GPR139 in the submicromolar range. α-MSH1-9 was found to correspond to the product of a predicted cleavage site in the prepro-protein pro-opiomelanocortin (POMC). Our results demonstrate that GPR139 is a peptide receptor, activated by ACTH, α-MSH, β-MSH, the conserved core motif HFRW as well as a potential endogenous peptide α-MSH1-9. Further studies are needed to determine the functional relevance of GPR139 mediated signaling by these peptides.This work was supported by the Lundbeck Foundation (separate grants to H.B.-O., D.S.P and D.E.G. [R169-2013-16327]), the A. P. Møller Foundation for the Advancement of Science (H.B.-O.), the European Research Council (DE-ORPHAN 639125; DEG), the Carlsberg Foundation (D.S.P.) and The Danish Council for Independent Research (DFF – 1331-00180) and the Wellcome Trust (098497/Z/12/Z), NIHR Biomedical Research Centre, MRC, Bernard Wolfe Endowment and ERC (282374) (I.S.F.
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