1,554 research outputs found
Intertwining Relations for the Deformed D1D5 CFT
The Higgs branch of the D1D5 system flows in the infrared to a
two-dimensional N=(4,4) SCFT. This system is believed to have an "orbifold
point" in its moduli space where the SCFT is a free sigma model with target
space the symmetric product of copies of four-tori; however, at the orbifold
point gravity is strongly coupled and to reach the supergravity point one needs
to turn on the four exactly marginal deformations corresponding to the blow-up
modes of the orbifold SCFT. Recently, technology has been developed for
studying these deformations and perturbing the D1D5 CFT off its orbifold point.
We present a new method for computing the general effect of a single
application of the deformation operators. The method takes the form of
intertwining relations that map operators in the untwisted sector before
application of the deformation operator to operators in the 2-twisted sector
after the application of the deformation operator. This method is
computationally more direct, and may be of theoretical interest. This line of
inquiry should ultimately have relevance for black hole physics.Comment: latex, 23 pages, 3 figure
Donor cell engineering with GSK3 inhibitor–loaded nanoparticles enhances engraftment after in utero transplantation
Host cell competition is a major barrier to engraftment after in utero hematopoietic cell transplantation (IUHCT). Here we describe a cell-engineering strategy using glycogen synthase kinase-3 (GSK3) inhibitor–loaded nanoparticles conjugated to the surface of donor hematopoietic cells to enhance their proliferation kinetics and ability to compete against their fetal host equivalents. With this approach, we achieved remarkable levels of stable, long-term hematopoietic engraftment for up to 24 weeks post-IUHCT. We also show that the salutary effects of the nanoparticle-released GSK3 inhibitor are specific to donor progenitor/stem cells and achieved by a pseudoautocrine mechanism. These results establish that IUHCT of hematopoietic cells decorated with GSK3 inhibitor–loaded nanoparticles can produce therapeutic levels of long-term engraftment and could therefore allow single-step prenatal treatment of congenital hematological disorders
Excitations in the deformed D1D5 CFT
We perform some simple computations for the first order deformation of the
D1D5 CFT off its orbifold point. It had been shown earlier that under this
deformation the vacuum state changes to a squeezed state (with the further
action of a supercharge). We now start with states containing one or two
initial quanta and write down the corresponding states obtained under the
action of deformation operator. The result is relevant to the evolution of an
initial excitation in the CFT dual to the near extremal D1D5 black hole: when a
left and a right moving excitation collide in the CFT, the deformation operator
spreads their energy over a larger number of quanta, thus evolving the state
towards the infrared.Comment: 26 pages, Latex, 4 figure
Deforming the D1D5 CFT away from the orbifold point
The D1D5 brane bound state is believed to have an `orbifold point' in its
moduli space which is the analogue of the free Yang Mills theory for the D3
brane bound state. The supergravity geometry generated by D1 and D5 branes is
described by a different point in moduli space, and in moving towards this
point we have to deform the CFT by a marginal operator: the `twist' which links
together two copies of the CFT. In this paper we find the effect of this
deformation operator on the simplest physical state of the CFT -- the Ramond
vacuum. The twist deformation leads to a final state that is populated by pairs
of excitations like those in a squeezed state. We find the coefficients
characterizing the distribution of these particle pairs (for both bosons and
fermions) and thus write this final state in closed form.Comment: 30 pages, 4 figures, Late
Lifshitz black holes in Brans-Dicke theory
We present an exact asymptotically Lifshitz black hole solution in
Brans-Dicke theory of gravity in arbitrary dimensions in presence of
a power-law potential. In this solution, the dynamical exponent is
determined in terms of the Brans-Dicke parameter and . Asymptotic
Lifshitz condition at infinity requires , which corresponds to
. On the other hand, the no-ghost condition
for the scalar field in the Einstein frame requires . We
compute the Hawking temperature of the black hole solution and discuss the
problems encountered and the proposals in defining its thermodynamic
properties. A generalized solution charged under the Maxwell field is also
presented.Comment: 32 pages, no figure. v2: revised version. Section 3.1 and Appendix B
improved. The argument in Appendix A clarified. v3: References added. v4:
analysis on the black hole thermodynamical properties corrected. Final
version to appear in JHE
Prevalence and intensity of Haemoproteus columbae in three species of wild doves from Brazil
Tendências da internação e da mortalidade infantil por diarréia: Brasil, 1995 a 2005
Uso de diferentes critérios para avaliação da inadequação do pré-natal: um estudo de base populacional no extremo Sul do Brasil
Identification of Type 1 Diabetes-Associated DNA Methylation Variable Positions That Precede Disease Diagnosis
Monozygotic (MZ) twin pair discordance for childhood-onset Type 1 Diabetes (T1D) is similar to 50%, implicating roles for genetic and non-genetic factors in the aetiology of this complex autoimmune disease. Although significant progress has been made in elucidating the genetics of T1D in recent years, the non-genetic component has remained poorly defined. We hypothesized that epigenetic variation could underlie some of the non-genetic component of T1D aetiology and, thus, performed an epigenome-wide association study (EWAS) for this disease. We generated genome-wide DNA methylation profiles of purified CD14(+) monocytes (an immune effector cell type relevant to T1D pathogenesis) from 15 T1D-discordant MZ twin pairs. This identified 132 different CpG sites at which the direction of the intra-MZ pair DNA methylation difference significantly correlated with the diabetic state, i.e. T1D-associated methylation variable positions (T1D-MVPs). We confirmed these T1D-MVPs display statistically significant intra-MZ pair DNA methylation differences in the expected direction in an independent set of T1D-discordant MZ pairs (P = 0.035). Then, to establish the temporal origins of the T1D-MVPs, we generated two further genome-wide datasets and established that, when compared with controls, T1D-MVPs are enriched in singletons both before (P = 0.001) and at (P = 0.015) disease diagnosis, and also in singletons positive for diabetes-associated autoantibodies but disease-free even after 12 years follow-up (P = 0.0023). Combined, these results suggest that T1D-MVPs arise very early in the etiological process that leads to overt T1D. Our EWAS of T1D represents an important contribution toward understanding the etiological role of epigenetic variation in type 1 diabetes, and it is also the first systematic analysis of the temporal origins of disease-associated epigenetic variation for any human complex disease
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