4,599 research outputs found
Quantum Back Reaction to asymptotically AdS Black Holes
We analyze the effects of the back reaction due to a conformal field theory
(CFT) on a black hole spacetime with negative cosmological constant. We study
the geometry numerically obtained by taking into account the energy momentum
tensor of CFT approximated by a radiation fluid. We find a sequence of
configurations without a horizon in thermal equilibrium (CFT stars), followed
by a sequence of configurations with a horizon. We discuss the thermodynamic
properties of the system and how back reaction effects alter the space-time
structure. We also provide an interpretation of the above sequence of solutions
in terms of the AdS/CFT correspondence. The dual five-dimensional description
is given by the Karch-Randall model, in which a sequence of five-dimensional
floating black holes followed by a sequence of brane localized black holes
correspond to the above solutions.Comment: 13 pages, 10 figure
The roles of the DAZ family in spermatogenesis: More than just translation?
The DAZ family of genes are important fertility factors in animals,
including humans. The family consists of Y-linked DAZ, and autosomal
homologs Boule and Dazl. All three genes encode
RNA-binding proteins that are nearly exclusively expressed in germ cells. The
DAZ family is highly conserved, with ancestral Boule
present in sea anemones through humans, Dazl conserved among vertebrates,
and DAZ present only in higher primates. Here we review studies on
DAZ family genes from multiple organisms, and summarize the common
features of each DAZ gene and their roles during spermatogenesis in
animals. DAZ family proteins are thought to activate the translation of RNA targets, but
recent work has uncovered additional functions. Boule,
Dazl, and DAZ likely function through similar
mechanisms, and we present known functions of the DAZ family in
spermatogenesis, and discuss possible mechanisms in addition to translation
activation
Purification of human albumin by the combination of the method of Cohn with liquid chromatography
Conformal Bulk Fields, Dark Energy and Brane Dynamics
In the Randall-Sundrum scenario we analyze the dynamics of a spherically
symmetric 3-brane when the bulk is filled with matter fields. Considering a
global conformal transformation whose factor is the symmetric warp we
find a new set of exact dynamical solutions for which gravity is bound to the
brane. The set corresponds to a certain class of conformal bulk fields. We
discuss the geometries which describe the dynamics on the brane of polytropic
dark energy.Comment: 12 pages, latex, 2 figures. Talk given by Rui Neves at the Fourth
International Conference on Physics Beyond the Standard Model, Beyond the
Desert 03, Fundamental Experimental and Theoretical Developments in Particle
Physics, Accelerator, Non-Accelerator and Space Approaches, Max Planck
Institut f. Kernphysik/MPI Heidelberg, Castle Ringberg, Tegernsee, Germany,
9-14 June 2003. To be published in the Conference Proceedings,
Springer-Verlag, Heidelberg, German
Perimembrane Aurora-A Expression is a Significant Prognostic Factor in Correlation with Proliferative Activity in Non-Small-Cell Lung Cancer (NSCLC)
Enhanced Tubulation of Liposome Containing Cardiolipin by MamY Protein from Magnetotactic Bacteria
Lipid tubules are of particular interest for many potential applications in nanotechnology. Among various lipid tubule fabrication techniques, the morphological regulation of membrane structure by proteins mimicking biological processes may provide the chances to form lipid tubes with highly tuned structures. Magnetotactic bacteria synthesize magnetosomes (a unique prokaryotic organelle comprising a magnetite crystal within a lipid envelope). MamY protein is previously identified as the magnetosome protein responsible for magnetosome vesicle formation and stabilization. Furthermore, MamY is shown in vitro liposome tubulation activity. In this study, the interaction of MamY and phospholipids is investigated by using a lipids-immobilized membrane strip and a peptide array. Here, the binding of MamY to the anionic phospholipid, cardiolipin, is found and enhanced liposome tubulation efficiency. The authors propose the interaction is responsible for recruiting and locating cardiolipin to elongate liposome in vitro. The authors also suggest a similar mechanism for the invagination site in magnetosomes vesicle formation, where the lipid itself contributes further to increasing the curvature. These findings are highly important to develop an effective biomimetic synthesis technique of lipid tubules and to elucidate the unique prokaryotic organelle formation in magnetotactic bacteria
New AdS solitons and brane worlds with compact extra-dimensions
We construct new static, asymptotically AdS solutions where the conformal
infinity is the product of Minkowski spacetime and a sphere . Both
globally regular, soliton-type solutions and black hole solutions are
considered. The black holes can be viewed as natural AdS generalizations of the
Schwarzschild black branes in Kaluza-Klein theory. The solitons provide new
brane-world models with compact extra-dimensions. Different from the
Randall-Sundrum single-brane scenario, a Schwarzschild black hole on the Ricci
flat part of these branes does not lead to a naked singularity in the bulk.Comment: 28 pages, 4 figure
Decitabine impact on the endocytosis regulator RhoA, the folate carriers RFC1 and FOLR1, and the glucose transporter GLUT4 in human tumors.
BackgroundIn 31 solid tumor patients treated with the demethylating agent decitabine, we performed tumor biopsies before and after the first cycle of decitabine and used immunohistochemistry (IHC) to assess whether decitabine increased expression of various membrane transporters. Resistance to chemotherapy may arise due to promoter methylation/downregulation of expression of transporters required for drug uptake, and decitabine can reverse resistance in vitro. The endocytosis regulator RhoA, the folate carriers FOLR1 and RFC1, and the glucose transporter GLUT4 were assessed.ResultsPre-decitabine RhoA was higher in patients who had received their last therapy >3 months previously than in patients with more recent prior therapy (Pā=ā0.02), and varied inversely with global DNA methylation as assessed by LINE1 methylation (rā=ā-0.58, Pā=ā0.006). Tumor RhoA scores increased with decitabine (Pā=ā0.03), and RFC1 also increased in patients with pre-decitabine scores ā¤150 (Pā=ā0.004). Change in LINE1 methylation with decitabine did not correlate significantly with change in IHC scores for any transporter assessed. We also assessed methylation of the RFC1 gene (alias SLC19A1). SLC19A1 methylation correlated with tumor LINE1 methylation (rā=ā0.45, Pā=ā0.02). There was a small (statistically insignificant) decrease in SLC19A1 methylation with decitabine, and there was a trend towards change in SLC19A1 methylation with decitabine correlating with change in LINE1 methylation (rā=ā0.47, P <0.15). While SLC19A1 methylation did not correlate with RFC1 scores, there was a trend towards an inverse correlation between change in SLC19A1 methylation and change in RFC1 expression (rā=ā-0.45, Pā=ā0.19).ConclusionsIn conclusion, after decitabine administration, there was increased expression of some (but not other) transporters that may play a role in chemotherapy uptake. Larger patient numbers will be needed to define the extent to which this increased expression is associated with changes in DNA methylation
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