549 research outputs found
Geometry of open strings ending on backreacting D3-branes
We investigate open string theory on backreacting D3-branes using a spacetime
approach. We study in detail the half-BPS supergravity solutions describing
open strings ending on D3-branes, in the near horizon of the D3-branes. We
recover quantitatively several non-trivial features of open string physics
including the appearance of D3-brane spikes, the polarization of fundamental
strings into D5-branes, and the Hanany-Witten effect. Finally we detail the
computation of the gravitational potential between two open strings, and
contrast it with the holographic computation of Wilson lines. We argue that the
D-brane backreaction has a large influence on the low-energy gravity, which may
lead to experimental tests for string theory brane-world scenarios.Comment: 64 pages, 20 figure
Allergic Rhinitis and its Associated Co-Morbidities at Bugando Medical Centre in Northwestern Tanzania; A Prospective Review of 190 Cases.
Allergic rhinitis is one of the commonest atopic diseases which contribute to significant morbidity world wide while its epidemiology in Tanzania remains sparse. There was paucity of information regarding allergic rhinitis in our setting; therefore it was important to conduct this study to describe our experience on allergic rhinitis, associated co-morbidities and treatment outcome in patients attending Bugando Medical Centre. This was descriptive cross-sectional study involving all patients with a clinical diagnosis of allergic rhinitis at Bugando Medical Centre over a three-month period between June 2011 and August 2011. Data was collected using a pre-tested coded questionnaire and analyzed using SPSS statistical computer software version 17.0. A total of 190 patients were studied giving the prevalence of allergic rhinitis 14.7%. The median age of the patients was 8.5 years. The male to female ratio was 1:1. Adenoid hypertrophy, tonsillitis, hypertrophy of inferior turbinate, nasal polyps, otitis media and sinusitis were the most common co-morbidities affecting 92.6% of cases and were the major reason for attending hospital services. Sleep disturbance was common in children with adenoids hypertrophy (χ2 = 28.691, P = 0.000). Allergic conjunctivitis was found in 51.9%. The most common identified triggers were dust, strong perfume odors and cold weather (P < 0.05). Strong perfume odors affect female than males (χ2 = 4.583, P = 0.032). In this study family history of allergic rhinitis was not a significant risk factor (P =0.423). The majority of patients (68.8%) were treated surgically for allergic rhinitis co morbidities. Post operative complication and mortality rates were 2.9% and 1.6% respectively. The overall median duration of hospital stay of in-patients was 3 days (2 - 28 days). Most patients (98.4%) had satisfactory results at discharge. The study shows that allergic rhinitis is common in our settings representing 14.7% of all otorhinolaryngology and commonly affecting children and adolescent. Sufferers seek medical services due to co-morbidities of which combination of surgical and medical treatment was needed. High index of suspicions in diagnosing allergic rhinitis and early treatment is recommended
Mellin Amplitudes for Dual Conformal Integrals
Motivated by recent work on the utility of Mellin space for representing
conformal correlators in /CFT, we study its suitability for representing
dual conformal integrals of the type which appear in perturbative scattering
amplitudes in super-Yang-Mills theory. We discuss Feynman-like rules for
writing Mellin amplitudes for a large class of integrals in any dimension, and
find explicit representations for several familiar toy integrals. However we
show that the power of Mellin space is that it provides simple representations
even for fully massive integrals, which except for the single case of the
4-mass box have not yet been computed by any available technology. Mellin space
is also useful for exhibiting differential relations between various multi-loop
integrals, and we show that certain higher-loop integrals may be written as
integral operators acting on the fully massive scalar -gon in
dimensions, whose Mellin amplitude is exactly 1. Our chief example is a very
simple formula expressing the 6-mass double box as a single integral of the
6-mass scalar hexagon in 6 dimensions.Comment: 29+7 page
Natural coagulates for wastewater treatment; a review for application and mechanism
The increase of water demand and wastewater generation is among the global concerns in the world. The less effective management of water sources leads to serious consequences, the direct disposal of untreated wastewater is associated with the environmental pollution, elimination of aquatic life and the spread of deadly epidemics. The flocculation process is one of the most important stages in water and wastewater treatment plants, wherein this phase the plankton, colloidal particles, and pollutants are precipitated and removed. Two major types of coagulants are used in the flocculation process included the chemical and natural coagulants. Many studies have been performed to optimize the flocculation process while most of these studies have confirmed the hazardous effects of chemical coagulants utilization on the ecosystem. This chapter reviews a summary of the coagulation/flocculation processes using natural coagulants as well as reviews one of the most effective natural methods of water and wastewater treatment
Bile duct involvement by hepatocellular carcinoma: A rare occurrence and poor prognostic indicator in bile duct brushing samples
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153086/1/cncy22185_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153086/2/cncy22185.pd
More stories on Th17 cells
For more than two decades, immunologists have been using the so-called Th1/Th2 paradigm to explain most of the phenomena related to adaptive immunity. the Th1/Th2 paradigm implied the existence of two different, mutually regulated, CD4(+) T helper subsets: Th1 cells, driving cell-mediated immune responses involved in tissue damage and fighting infection against intracellular parasites; and Th2 cells that mediate IgE production and are particularly involved in eosinophilic inflammation, allergy and clearance of helminthic infections. A third member of the T helper set, IL-17-producing CD4(+) T cells, now called Th17 cells, was recently described as a distinct lineage that does not share developmental pathways with either Th1 or Th2 cells. the Th17 subset has been linked to autoimmune disorders, being able to produce IL-17, IL-17F and IL-21 among other inflammatory cytokines. Interestingly, it has been reported that there is not only a cross-regulation among Th1, Th2 and Th17 effector cells but there is also a dichotomy in the generation of Th17 and T regulatory cells. Therefore, Treg and Th17 effector cells arise in a mutually exclusive fashion, depending on whether they are activated in the presence of TGF-beta or TGF-beta plus inflammatory cytokines such as IL-6. This review will address the discovery of the Th17 cells, and recent progress on their development and regulation.Crohn's and Colitis Foundation of AmericaNIHLa Jolla Inst Allergy & Immunol, La Jolla, CA 92037 USAUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilNIH: RO1 AI050265-06Web of Scienc
On Feynman rules for Mellin amplitudes in AdS/CFT
The computation of CFT correlation functions via Witten diagrams in AdS space
can be simplified via the Mellin transform. Recently a set of Feynman rules for
tree-level Mellin space amplitudes has been proposed for scalar theories. In
this note we derive these rules by explicitly evaluating all of the relevant
Witten diagram integrals for the scalar phi^n theory. We also check that the
rules reduce to the usual Feynman rules in the flat space limit.Comment: minor corrections, published versio
Granular cell tumors of the urinary bladder
BACKGROUND: Granular cell tumors (GCTs) are extremely rare lesions of the urinary bladder with only nine cases being reported in world literature of which one was malignant. Generally believed to be of neural origin based on histochemical, immunohistochemical, and ultrastructural studies; they mostly follow a clinically benign course but are commonly mistaken for malignant tumors since they are solid looking, ulcerated tumors with ill-defined margins. MATERIALS AND METHODS: We herein report two cases of GCTs, one benign and one malignant, presenting with gross hematuria in a 14- and a 47-year-old female, respectively. RESULTS: Histopathology revealed characteristic GCTs with positive immunostaining for neural marker (S-100) and negative immunostaining for epithelial (cytokeratin, Cam 5.2, AE/A13), neuroendocrine (neuron specific enolase, chromogranin A, and synaptophysin) and sarcoma (desmin, vimentin) markers. The benign tumor was successfully managed conservatively with transurethral resection alone while for the malignant tumor, radical cystectomy, hysterectomy with bilateral salpingo-oophorectomy, anterior vaginectomy, plus lymph node dissection was done. Both cases show long-term disease free survival. CONCLUSION: We recommend careful pathologic assessment for establishing the appropriate diagnosis and either a conservative or aggressive surgical treatment for benign or localized malignant GCT of the urinary bladder, respectively
AdS Field Theory from Conformal Field Theory
We provide necessary and sufficient conditions for a Conformal Field Theory
to have a description in terms of a perturbative Effective Field Theory in AdS.
The first two conditions are well-known: the existence of a perturbative `1/N'
expansion and an approximate Fock space of states generated by a finite number
of low-dimension operators. We add a third condition, that the Mellin
amplitudes of the CFT correlators must be well-approximated by functions that
are bounded by a polynomial at infinity in Mellin space, or in other words,
that the Mellin amplitudes have an effective theory-type expansion. We explain
the relationship between our conditions and unitarity, and provide an analogy
with scattering amplitudes that becomes exact in the flat space limit of AdS.
The analysis also yields a simple connection between conformal blocks and AdS
diagrams, providing a new calculational tool very much in the spirit of the
S-Matrix program.
We also begin to explore the potential pathologies associated with higher
spin fields in AdS by generalizing Weinberg's soft theorems to AdS/CFT. The AdS
analog of Weinberg's argument constrains the interactions of conserved currents
in CFTs, but there are potential loopholes that are unavailable to theories of
massless higher spin particles in flat spacetime.Comment: 31+7 pages, 5 figure
Cloning, expression and nuclear localization of human NPM3, a member of the nucleophosmin/nucleoplasmin family of nuclear chaperones
BACKGROUND: Studies suggest that the related proteins nucleoplasmin and nucleophosmin (also called B23, NO38 or numatrin) are nuclear chaperones that mediate the assembly of nucleosomes and ribosomes, respectively, and that these activities are accomplished through the binding of basic proteins via their acidic domains. Recently discovered and less well characterized members of this family of acidic phosphoproteins include mouse nucleophosmin/nucleoplasmin 3 (Npm3) and Xenopus NO29. Here we report the cloning and initial characterization of the human ortholog of Npm3. RESULTS: Human genomic and cDNA clones of NPM3 were isolated and sequenced. NPM3 lies 5.5 kb upstream of FGF8 and thus maps to chromosome 10q24-26. In addition to amino acid similarities, NPM3 shares many physical characteristics with the nucleophosmin/nucleoplasmin family, including an acidic domain, multiple potential phosphorylation sites and a putative nuclear localization signal. Comparative analyses of 14 members of this family from various metazoans suggest that Xenopus NO29 is a candidate ortholog of human and mouse NPM3, and they further group both proteins closer with the nucleoplasmins than with the nucleophosmins. Northern blot analysis revealed that NPM3 was strongly expressed in all 16 human tissues examined, with especially robust expression in pancreas and testis; lung displayed the lowest level of expression. An analysis of subcellular fractions of NIH3T3 cells expressing epitope-tagged NPM3 revealed that NPM3 protein was localized solely in the nucleus. CONCLUSIONS: Human NPM3 is an abundant and widely expressed protein with primarily nuclear localization. These biological activities, together with its physical relationship to the chaparones nucleoplasmin and nucleophosmin, are consistent with the proposed function of NPM3 as a molecular chaperone functioning in the nucleus
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