3,331 research outputs found
The Holographic RG flow to conformal and non-conformal theory
We review some aspects of the AdS supergravity description of RG flows. The
case of a flow to an IR CFT can be rigorously studied within the framework of
supergravity. Here we discuss various central charges of the conformal theory
(included the usually neglected ones) and we compare them with QFT
expectations. The case of flows to non-conformal theories is more problematic
in that one usually encounters a naked singularity. We mainly focus on the flow
to an IR N=1 super Yang-Mills theory. We discuss the properties of the solution
and we briefly comment on the fate of the singularity. We also compare the
supergravity results with the expectations of an N=1 SYM at strong coupling.Comment: LaTex,13 pages, 3 embedded eps figures, minor changes.Contribution to
the proceedings of the TMR Conference on Quantum Aspects of Gauge Theories,
Supersymmetry and Unification, Paris, 1-7 September 199
Confinement and Condensates Without Fine Tuning in Supergravity Duals of Gauge Theories
We discuss a solution of the equations of motion of five-dimensional gauged
type IIB supergravity that describes confining SU(N) gauge theories at large N
and large 't Hooft parameter. We prove confinement by computing the Wilson
loop, and we show that our solution is generic, independent of most of the
details of the theory. In particular, the Einstein-frame metric near its
singularity, and the condensates of scalar, composite operators are universal.
Also universal is the discreteness of the glueball mass spectrum and the
existence of a mass gap. The metric is also identical to a generically
confining solution recently found in type 0B theory.Comment: 19 pages, Late
Novel Local CFT and Exact Results on Perturbations of N=4 Super Yang Mills from AdS Dynamics
We find new, local, non-supersymmetric conformal field theories obtained by
relevant deformations of the N=4 super Yang Mills theory in the large
limit. We contruct interpolating supergravity solutions that naturally
represent the flow from the N=4 super Yang Mills UV theory to these
non-supersymmetric IR fixed points. We also study the linearization around the
N=4 superconformal point of N=1 supersymmetric, marginal deformations. We show
that they give rise to N=1 superconformal fixed points, as expected from
field-theoretical arguments.Comment: Version accepted by JHE
AdS vacua with scale separation from IIB supergravity
Only two kinds of compactification are known that lead to four-dimensional
supersymmetric AdS vacua with moduli stabilisation and separation of scales at
tree-level. The most studied ones are compactifications of massive IIA
supergravity on SU(3) structures with smeared O6 planes, for which a general
ten-dimensional expression for the solution in terms of the SU(3) structure was
found. Less studied are compactifications of IIB supergravity with smeared
O5/O7 planes. In this paper we derive a general ten-dimensional expression for
the smeared O5/O7 solutions in terms of SU(2) structures. For a specific choice
of orientifold projections, we recover the known examples and we also provide
new explicit solutions.Comment: 27 + 16 pages; v2 references added and typos in few equations
correcte
Comment on "Germinal center helper T cells are dual functional regulatory cells with suppressive activity to conventional CD4+ T cells"
http://www.jimmunol.org/content/179/2/731.1.ful
On the rate of convergence in periodic homogenization of scalar first-order ordinary differential equations
In this paper, we study the rate of convergence in periodic homogenization of
scalar ordinary differential equations. We provide a quantitative error
estimate between the solutions of a first-order ordinary differential equation
with rapidly oscillating coefficients and the limiting homogenized solution. As
an application of our result, we obtain an error estimate for the solution of
some particular linear transport equations
More on donor-derived T-cell leukemia after bone marrow transplantation
http://www.nejm.org/doi/full/10.1056/NEJMc06105
Temsirolimus in the treatment of relapsed and/or refractory mantle cell lymphoma
Patients with mantle cell lymphoma (MCL) have a poor prognosis; consequently, new therapeutic approaches, such as rapamycin and its derivates, mammalian target of rapamycin (mTOR) inhibitors, are warranted. Temsirolimus (also known as CCI-779), a dihydroester of rapamycin, in MCL cell lines inhibited mTOR, downregulated p21 and v-Raf, and induced autophagy. The first clinical trial in MCL patients was performed using 250 mg of temsirolimus weekly for 6–12 cycles. The overall response rate was 38%; the median time to progression was 6.5 months, median overall survival was 12 months, and the median duration of response was 6.9 months. At lower dose (25 mg/week), the overall response rate was 41%, median overall survival was 14 months, and time to progression was 6 months. In another trial, 162 patients were randomly assigned to receive temsirolimus at 2 different doses (175 mg/week for 3 weeks, then 75 mg or 25 mg/week) or a treatment chosen by the investigator among the most frequently adopted single agents for treatment of relapsed MCL. Patients treated with 175/75 mg of temsirolimus had significantly higher response rates and longer progression-free survival than those treated with investigator’s choice therapy. These data support the use of mTOR inhibitors for the treatment of MCL, probably in combination with other agents, such as antiangiogenic drugs or histone acetylase inhibitors
High frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex modulates sensorimotor cortex function in the transition to sustained muscle pain
Based on reciprocal connections between the dorsolateral prefrontal cortex (DLPFC) and basal-ganglia regions associated with sensorimotor cortical excitability, it was hypothesized that repetitive transcranial magnetic stimulation (rTMS) of the left DLPFC would modulate sensorimotor cortical excitability induced by muscle pain. Muscle pain was provoked by injections of nerve growth factor (end of Day-0 and Day-2) into the right extensor carpi radialis brevis (ECRB) muscle in two groups of 15 healthy participants receiving 5 daily sessions (Day-0 to Day-4) of active or sham rTMS. Muscle pain scores and pressure pain thresholds (PPTs) were collected (Day-0, Day-3, Day-5). Assessment of motor cortical excitability using TMS (mapping cortical ECRB muscle representation) and somatosensory evoked potentials (SEPs) from electrical stimulation of the right radial nerve were recorded at Day-0 and Day-5. At Day-0 versus Day-5, the sham compared to active group showed: Higher muscle pain scores and reduced PPTs (P < 0.04); decreased frontal N30 SEP (P < 0.01); increased TMS map volume (P < 0.03). These results indicate that muscle pain exerts modulatory effects on the sensorimotor cortical excitability and left DLPFC rTMS has analgesic effects and modulates pain-induced sensorimotor cortical adaptations. These findings suggest an important role of prefrontal to basal-ganglia function in sensorimotor cortical excitability and pain processing
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