1,223 research outputs found
Status and subdivision of the Parmeener Super-group
Late Palaeozoic and Early Mesozoic rocks of the Parmeener Super-Group
are subdivided on a strict lithostratigraphical basis, and not in the time terms
'Permian' and 'Triassic'
UBE2QL1 is Disrupted by a Constitutional Translocation Associated with Renal Tumor Predisposition and is a Novel Candidate Renal Tumor Suppressor Gene
Investigation of rare familial forms of renal cell carcinoma (RCC) has led to the identification of genes such as VHL and MET that are also implicated in the pathogenesis of sporadic RCC. In order to identify a novel candidate renal tumor suppressor gene, we characterized the breakpoints of a constitutional balanced translocation, t(5;19)(p15.3;q12), associated with familial RCC and found that a previously uncharacterized gene UBE2QL1 was disrupted by the chromosome 5 breakpoint. UBE2QL1 mRNA expression was downregulated in 78.6% of sporadic RCC and, although no intragenic mutations were detected, gene deletions and promoter region hypermethylation were detected in 17.3% and 20.3%, respectively, of sporadic RCC. Reexpression of UBE2QL1 in a deficient RCC cell line suppressed anchorage-independent growth. UBE2QL1 shows homology to the E2 class of ubiquitin conjugating enzymes and we found that (1) UBE2QL1 possesses an active-site cysteine (C88) that is monoubiquitinated in vivo, and (2) UBE2QL1 interacts with FBXW7 (an F box protein providing substrate recognition to the SCF E3 ubiquitin ligase) and facilitates the degradation of the known FBXW7 targets, CCNE1 and mTOR. These findings suggest UBE2QL1 as a novel candidate renal tumor suppressor gen
Modifying the Sum Over Topological Sectors and Constraints on Supergravity
The standard lore about the sum over topological sectors in quantum field
theory is that locality and cluster decomposition uniquely determine the sum
over such sectors, thus leading to the usual theta-vacua. We show that without
changing the local degrees of freedom, a theory can be modified such that the
sum over instantons should be restricted; e.g. one should include only
instanton numbers which are divisible by some integer p. This conclusion about
the configuration space of quantum field theory allows us to carefully
reconsider the quantization of parameters in supergravity. In particular, we
show that FI-terms and nontrivial Kahler forms are quantized. This analysis
also leads to a new derivation of recent results about linearized supergravity.Comment: 17 pages, minor change
String theoretic QCD axions in the light of PLANCK and BICEP2
The QCD axion solving the strong CP problem may originate from antisymmetric
tensor gauge fields in compactified string theory, with a decay constant around
the GUT scale. Such possibility appears to be ruled out now by the detection of
tensor modes by BICEP2 and the PLANCK constraints on isocurvature density
perturbations. A more interesting and still viable possibility is that the
string theoretic QCD axion is charged under an anomalous U(1)_A gauge symmetry.
In such case, the axion decay constant can be much lower than the GUT scale if
moduli are stabilized near the point of vanishing Fayet-Illiopoulos term, and
U(1)_A-charged matter fields get a vacuum value far below the GUT scale due to
a tachyonic SUSY breaking scalar mass. We examine the symmetry breaking pattern
of such models during the inflationary epoch with the Hubble expansion rate
10^{14} GeV, and identify the range of the QCD axion decay constant, as well as
the corresponding relic axion abundance, consistent with known cosmological
constraints. In addition to the case that the PQ symmetry is restored during
inflation, there are other viable scenarios, including that the PQ symmetry is
broken during inflation at high scales around 10^{16}-10^{17} GeV due to a
large Hubble-induced tachyonic scalar mass from the U(1)_A D-term, while the
present axion scale is in the range 10^{9}-5\times 10^{13} GeV, where the
present value larger than 10^{12} GeV requires a fine-tuning of the axion
misalignment angle. We also discuss the implications of our results for the
size of SUSY breaking soft masses.Comment: 29 pages, 1 figure; v3: analysis updated including the full
anharmonic effects, references added, version accepted for publication in
JHE
Aidnogenesis via Leptogenesis and Dark Sphalerons
We discuss aidnogenesis, the generation of a dark matter asymmetry via new
sphaleron processes associated to an extra non-abelian gauge symmetry common to
both the visible and the dark sectors. Such a theory can naturally produce an
abundance of asymmetric dark matter which is of the same size as the lepton and
baryon asymmetries, as suggested by the similar sizes of the observed baryonic
and dark matter energy content, and provide a definite prediction for the mass
of the dark matter particle. We discuss in detail a minimal realization in
which the Standard Model is only extended by dark matter fermions which form
"dark baryons" through an SU(3) interaction, and a (broken) horizontal symmetry
that induces the new sphalerons. The dark matter mass is predicted to be
approximately 6 GeV, close to the region favored by DAMA and CoGeNT.
Furthermore, a remnant of the horizontal symmetry should be broken at a lower
scale and can also explain the Tevatron dimuon anomaly.Comment: Minor changes, discussion of present constraints expanded. 16 pages,
2 eps figures, REVTeX
Notes on Operator Equations of Supercurrent Multiplets and the Anomaly Puzzle in Supersymmetric Field Theories
Recently, Komargodski and Seiberg have proposed a new type of supercurrent
multiplet which contains the energy-momentum tensor and the supersymmetry
current consistently. In this paper we study quantum properties of the
supercurrent in renormalizable field theories. We point out that the new
supercurrent gives a quite simple resolution to the classic problem, called the
anomaly puzzle, that the Adler-Bardeen theorem applied to an R-symmetry current
is inconsistent with all order corrections to functions. We propose an
operator equation for the supercurrent in all orders of perturbation theory,
and then perform several consistency checks of the equation. The operator
equation we propose is consisitent with the one proposed by Shifman and
Vainshtein, if we take some care in interpreting the meaning of non-conserved
currents.Comment: 28 pages; v2:clarifications and references added, some minor change
Innate Recognition of Fungal Cell Walls
The emergence of fungal infections as major causes of morbidity and mortality in immunosuppressed individuals has prompted studies into how the host recognizes fungal pathogens. Fungi are eukaryotes and as such share many similarities with mammalian cells. The most striking difference, though, is the presence of a cell wall that serves to protect the fungus from environmental stresses, particularly osmotic changes [1]. This task is made challenging because the fungus must remodel itself to allow for cell growth and division, including the conversion to different morphotypes, such as occurs during germination of spherical spores into filamentous hyphae. The cell wall also connects the fungus with its environment by triggering intracellular signaling pathways and mediating adhesion to other cells and extracellular matrices. Here, important facts and concepts critical for understanding innate sensing of the fungal cell wall by mammalian pathogens are reviewed
General Argyres-Douglas Theory
We construct a large class of Argyres-Douglas type theories by compactifying
six dimensional (2,0) A_N theory on a Riemann surface with irregular
singularities. We give a complete classification for the choices of Riemann
surface and the singularities. The Seiberg-Witten curve and scaling dimensions
of the operator spectrum are worked out. Three dimensional mirror theory and
the central charges a and c are also calculated for some subsets, etc. Our
results greatly enlarge the landscape of N=2 superconformal field theory and in
fact also include previous theories constructed using regular singularity on
the sphere.Comment: 55 pages, 20 figures, minor revision and typos correcte
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