168 research outputs found
Quarkonium from the Fifth Dimension
Adding fundamental matter of mass m_Q to N=4 Yang Mills theory, we study
quarkonium, and "generalized quarkonium" containing light adjoint particles. At
large 't Hooft coupling the states of spin<=1 are anomalously light (Kruczenski
et al., hep-th/0304032). We examine their form factors, and show these hadrons
are unlike any known in QCD. By a traditional yardstick they appear infinite in
size (as with strings in flat space) but we show that this is a failure of the
yardstick. All of the hadrons are actually of finite size ~ \sqrt{g^2N}/m_Q,
regardless of their radial excitation level and of how many valence adjoint
particles they contain. Certain form factors for spin-1 quarkonia vanish in the
large-g^2N limit; thus these hadrons resemble neither the observed J/Psi
quarkonium states nor rho mesons.Comment: 57 pages, LaTeX, 5 figure
Lepton flavor violating decay in the general two Higgs Doublet model with the inclusion of non-universal extra dimensions
We predict the branching ratios of Z -> e^{\pm} \mu^{\pm}, Z -> e^{\pm}
\tau^{\pm} and Z -> \mu^{\pm} \tau^{\pm} decays in the model III version of the
two Higgs doublet model, with the inclusion of one and two spatial
non-universal extra dimensions. We observe that the the branching ratios are
not sensitive to a single extra dimension, however, this sensitivity is
considerably large for two extra dimensions.Comment: 21 pages, 7 Figure
Sialome of a Generalist Lepidopteran Herbivore: Identification of Transcripts and Proteins from Helicoverpa armigera Labial Salivary Glands
Although the importance of insect saliva in insect-host plant interactions has been acknowledged, there is very limited information on the nature and complexity of the salivary proteome in lepidopteran herbivores. We inspected the labial salivary transcriptome and proteome of Helicoverpa armigera, an important polyphagous pest species. To identify the majority of the salivary proteins we have randomly sequenced 19,389 expressed sequence tags (ESTs) from a normalized cDNA library of salivary glands. In parallel, a non-cytosolic enriched protein fraction was obtained from labial salivary glands and subjected to two-dimensional gel electrophoresis (2-DE) and de novo peptide sequencing. This procedure allowed comparison of peptides and EST sequences and enabled us to identify 65 protein spots from the secreted labial saliva 2DE proteome. The mass spectrometry analysis revealed ecdysone, glucose oxidase, fructosidase, carboxyl/cholinesterase and an uncharacterized protein previously detected in H. armigera midgut proteome. Consistently, their corresponding transcripts are among the most abundant in our cDNA library. We did find redundancy of sequence identification of saliva-secreted proteins suggesting multiple isoforms. As expected, we found several enzymes responsible for digestion and plant offense. In addition, we identified non-digestive proteins such as an arginine kinase and abundant proteins of unknown function. This identification of secreted salivary gland proteins allows a more comprehensive understanding of insect feeding and poses new challenges for the elucidation of protein function
The effects of non-universal extra dimensions on the radiative lepton flavor decays \mu\to e\gamma and \tau\to \mu\gamma in the two Higgs doublet model
We study the effect of non-universal extra dimensions on the branching ratios
of the lepton flavor violating processes \mu\to e\gamma and \tau\to \mu\gamma
in the general two Higgs doublet model. We observe that these effects are small
for a single extra dimension, however, in the case of two extra dimensions
there is a considerable enhancement in the additional contributions.Comment: 16 Pages, 9 Figure
The influence of statins on the free intracellular calcium concentration in human umbilical vein endothelial cells
BACKGROUND: Statins are cholesterol-lowering drugs that are widely used to reduce the risk of cardiac infarction. Their beneficial clinical effects, however, are not restricted to their influence on cholesterol production. As several studies have shown that they have a potency of relaxing blood vessels. METHODS: We measured the effects of statins on the intracellular free calcium concentration ([Ca(2+)](i)) in human umbilical vein endothelial cells (HUVEC) after acute application and 24-h-preincubation of statins. RESULTS: Incubation of the cells for 24 h with cerivastatin or fluvastatin significantly increased the resting [Ca(2+)](i). For cerivastatin this effect manifested at a concentration of 1 ÎŒM. Increase of resting [Ca(2+)](i )in the presence of cerivastatin also occurred when the nitric oxide synthase was inhibited. Transient Ca(2+ )release induced by histamine was not affected. CONCLUSIONS: The increase of resting [Ca(2+)](i )after incubation with cerivastatin or fluvastatin may provide an explanation for the direct effects of statins on the endothelial-dependent vasodilatation and restoration of endothelial activity in vivo
New Results on Holographic Three-Point Functions
We exploit a gauge invariant approach for the analysis of the equations
governing the dynamics of active scalar fluctuations coupled to the
fluctuations of the metric along holographic RG flows. In the present approach,
a second order ODE for the active scalar emerges rather simply and makes it
possible to use the Green's function method to deal with (quadratic)
interaction terms. We thus fill a gap for active scalar operators, whose
three-point functions have been inaccessible so far, and derive a general,
explicitly Bose symmetric formula thereof. As an application we compute the
relevant three-point function along the GPPZ flow and extract the irreducible
trilinear couplings of the corresponding superglueballs by amputating the
external legs on-shell.Comment: v2: reference added, typos corrected v3: sign convention for
background changed, agrees with version published in JHE
Running Scaling Dimensions in Holographic Renormalization Group Flows
Holographic renormalization group flows can be interpreted in terms of
effective field theory. Based on such an interpretation, a formula for the
running scaling dimensions of gauge-invariant operators along such flows is
proposed. The formula is checked for some simple examples from the AdS/CFT
correspondence, but can be applied also in non-AdS/non-CFT cases.Comment: 14 pages, 2 figure
On higher derivative gravity, c-theorems and cosmology
We consider higher derivative gravity lagrangians in 3 and 4 dimensions,
which admit simple c-theorems, including upto six derivative curvature
invariants. Following a suggestion by Myers, these lagrangians are restricted
such that the fluctuations around (anti) de Sitter spaces have second order
linearized equations of motion. We study c-theorems both in the context of
AdS/CFT and cosmology. In the context of cosmology, the monotonic function is
the entropy defined on the apparent horizon through Wald's formula. Exact black
hole solutions which are asymptotically (anti) de Sitter are presented. An
interesting lower bound for entropy is found in de Sitter space. Some aspects
of cosmology in both D=3 and D=4 are discussed.Comment: 23 pages, v3: clarifications added, references adde
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