132 research outputs found
Large-N reduction in QCD-like theories with massive adjoint fermions
Large-N QCD with heavy adjoint fermions emulates pure Yang-Mills theory at
long distances. We study this theory on a four- and three-torus, and
analytically argue the existence of a large-small volume equivalence. For any
finite mass, center symmetry unbroken phase exists at sufficiently small volume
and this phase can be used to study the large-volume limit through the
Eguchi-Kawai equivalence. A finite temperature version of volume independence
implies that thermodynamics on R^3 x S^1 can be studied via a unitary matrix
quantum mechanics on S^1, by varying the temperature. To confirm this
non-perturbatively, we numerically study both zero- and one-dimensional
theories by using Monte-Carlo simulation. Order of finite-N corrections turns
out to be 1/N. We introduce various twisted versions of the reduced QCD which
systematically suppress finite-N corrections. Using a twisted model, we observe
the confinement/deconfinement transition on a 1^3 x 2-lattice. The result
agrees with large volume simulations of Yang-Mills theory. We also comment that
the twisted model can serve as a non-perturbative formulation of the
non-commutative Yang-Mills theory.Comment: 34 pages, 12 figures, version accepted for publication in PR
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AdS/CFT and Large-N Volume Independence
We study the Eguchi-Kawai reduction in the strong-coupling domain of gauge theories via the gravity dual of N=4 super-Yang-Mills on R{sup 3} x S{sup 1}. We show that D-branes geometrize volume independence in the center-symmetric vacuum and give supergravity predictions for the range of validity of reduced large-N models at strong coupling
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Multiflavor QCD* on R_3 * S_1: Studying Transition From Abelian to Non-Abelian Confinement
The center-stabilized multiflavor QCD* theories formulated on R{sub 3} x S{sub 1} exhibit both Abelian and non-Abelian confinement as a function of the S{sub 1} radius, similar to the Seiberg-Witten theory as a function of the mass deformation parameter. For sufficiently small number of flavors and small r(S{sub 1}), we show occurrence of a mass gap in gauge fluctuations, and linear confinement. This is a regime of confinement without continuous chiral symmetry breaking ({chi}SB). Unlike one-flavor theories where there is no phase transition in r(S{sub 1}), the multiflavor theories possess a single phase transition associated with breaking of the continuous {chi}S. We conjecture that the scale of the {chi}SB is parametrically tied up with the scale of Abelian to non-Abelian confinement transition
Isolated interrupted inferior vena cava with azygos continuation mimicking paraesophageal lymph node enlargement
We report a case of interrupted inferior vena cava with azygos continuation diagnosed as a isolated finding in a patient with lung carcinoma. Findings of the unopacified CT scan initially simulated a paraesophageal lymphadenopathy. The contrast - enhanced spiral CT scan showed a dilated azygos vein in the absence of definable inferior vena cava
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On Yang--Mills Theories with Chiral Matter at Strong Coupling
Strong coupling dynamics of Yang-Mills theories with chiral fermion content remained largely elusive despite much effort over the years. In this work, we propose a dynamical framework in which we can address non-perturbative properties of chiral, non-supersymmetric gauge theories, in particular, chiral quiver theories on S{sub 1} x R{sub 3}. Double-trace deformations are used to stabilize the center-symmetric vacuum. This allows one to smoothly connect smaller(S{sub 1}) to larger(S{sub 1}) physics (R{sub 4} is the limiting case) where the double-trace deformations are switched off. In particular, occurrence of the mass gap in the gauge sector and linear confinement due to bions are analytically demonstrated. We find the pattern of the chiral symmetry realization which depends on the structure of the ring operators, a novel class of topological excitations. The deformed chiral theory, unlike the undeformed one, satisfies volume independence down to arbitrarily small volumes (a working Eguchi-Kawai reduction) in the large N limit. This equivalence, may open new perspectives on strong coupling chiral gauge theories on R{sub 4}
Skin to calyx distance is not a predictive factor for miniaturized percutaneous nephrolithotomy outcomes
Modeling the Effects of Cell Cycle M-phase Transcriptional Inhibition on Circadian Oscillation
Circadian clocks are endogenous time-keeping systems that temporally organize biological processes. Gating of cell cycle events by a circadian clock is a universal observation that is currently considered a mechanism serving to protect DNA from diurnal exposure to ultraviolet radiation or other mutagens. In this study, we put forward another possibility: that such gating helps to insulate the circadian clock from perturbations induced by transcriptional inhibition during the M phase of the cell cycle. We introduced a periodic pulse of transcriptional inhibition into a previously published mammalian circadian model and simulated the behavior of the modified model under both constant darkness and light–dark cycle conditions. The simulation results under constant darkness indicated that periodic transcriptional inhibition could entrain/lock the circadian clock just as a light–dark cycle does. At equilibrium states, a transcriptional inhibition pulse of certain periods was always locked close to certain circadian phases where inhibition on Per and Bmal1 mRNA synthesis was most balanced. In a light–dark cycle condition, inhibitions imposed at different parts of a circadian period induced different degrees of perturbation to the circadian clock. When imposed at the middle- or late-night phase, the transcriptional inhibition cycle induced the least perturbations to the circadian clock. The late-night time window of least perturbation overlapped with the experimentally observed time window, where mitosis is most frequent. This supports our hypothesis that the circadian clock gates the cell cycle M phase to certain circadian phases to minimize perturbations induced by the latter. This study reveals the hidden effects of the cell division cycle on the circadian clock and, together with the current picture of genome stability maintenance by circadian gating of cell cycle, provides a more comprehensive understanding of the phenomenon of circading gating of cell cycle
Disrupting Circadian Homeostasis of Sympathetic Signaling Promotes Tumor Development in Mice
and why disruption of circadian rhythm may lead to tumorigenesis. oncogenic potential, leading to tumor development in the same organ systems in wild-type and circadian gene-mutant mice. is a clock-controlled physiological function. The central circadian clock paces extracellular mitogenic signals that drive peripheral clock-controlled expression of key cell cycle and tumor suppressor genes to generate a circadian rhythm in cell proliferation. Frequent disruption of circadian rhythm is an important tumor promoting factor
Malnutrition in patients treated for oral or oropharyngeal cancer—prevalence and relationship with oral symptoms: an explorative study
This study aimed to assess prevalence of malnutrition after treatment for oral/oropharyngeal cancer and to explore how oral symptoms relate to malnutrition after treatment. In this cross-sectional study, malnutrition (weight loss a parts per thousand yenaEuro parts per thousand 10% in 6 months or a parts per thousand yen5% in 1 month), oral symptoms (EORTC QLQ-H&N35 questionnaire and additional questions to assess chewing problems), dental status, trismus and dietary intake were assessed in 116 adult patients treated for oral/oropharyngeal cancer. Prevalence of malnutrition was 16% (95%CI: 10% to 23%). Prevalence of malnutrition in the period 0-3 months after treatment was significantly higher (25%) than in the periods > 3-12 months (13%) and > 12-36 months after treatment (3%, p = 0.008). Logistic multivariate regression analysis revealed that swallowing problems (p = 0.021) and insufficient protein intake were significantly related to malnutrition (p = 0.016). In conclusion, malnutrition is a considerable problem in patients treated for oral/oropharyngeal cancer, shortly after treatment. Of all oral symptoms, only swallowing problems were significantly related to malnutrition in the period after treatment for oral/oropharyngeal cancer
An international collaborative evaluation of central serous chorioretinopathy: different therapeutic approaches and review of literature. The European Vitreoretinal Society central serous chorioretinopathy study
Purpose: To study and compare the efficacy of different therapeutic options for the treatment of central serous chorioretinopathy (CSCR). Methods: This is a nonrandomized, international multicentre study on 1719 patients (1861 eyes) diagnosed with CSCR, from 63 centres (24 countries). Reported data included different methods of treatment and both results of diagnostic examinations [fluorescein angiography and/or optical coherent tomography (OCT)] and best-corrected visual acuity (BCVA) before and after therapy. The duration of observation had a mean of 11 months but was extended in a minority of cases up to 7 years. The aim of this study is to evaluate the efficacy of the different therapeutic options of CSCR in terms of both visual (BCVA) and anatomic (OCT) improvement. Results: One thousand seven hundred nineteen patients (1861 eyes) diagnosed with CSCR were included. Treatments performed were nonsteroidal anti-inflammatory eye drops, laser photocoagulation, micropulse diode laser photocoagulation, photodynamic therapy (PDT; Standard PDT, Reduced-dose PDT, Reduced-fluence PDT), intravitreal (IVT) antivascular endothelial growth factor injection (VEGF), observation and other treatments. The list of the OTHERS included both combinations of the main proposed treatments or a variety of other treatments such as eplerenone, spironolactone, acetazolamide, beta-blockers, anti-anxiety drugs, aspirin, folic acid, methotrexate, statins, vitis vinifera extract medication and pars plana vitrectomy. The majority of the patients were men with a prevalence of 77%. The odds ratio (OR) showed a partial or complete resolution of fluid on OCT with any treatment as compared with observation. In univariate analysis, the anatomical result (improvement in subretinal fluid using OCT at 1 month) was favoured by age <60 years (p < 0.005), no previous observation (p < 0.0002), duration less than 3 months (p < 0.0001), absence of CSCR in the fellow eye (p = 0.04), leakage outside of the arcade (p = 0.05) and fluid height >500 \u3bcm (p = 0.03). The OR for obtaining partial or complete resolution showed that anti-VEGF and eyedrops were not statistically significant; whereas PDT (8.5), thermal laser (11.3) and micropulse laser (8.9) lead to better anatomical results with less variability. In univariate analysis, the functional result at 1 month was favoured by first episode (p = 0.04), height of subretinal fluid >500 \u3bcm (p < 0.0001) and short duration of observation (p = 0.02). Finally, there was no statistically significant difference among the treatments at 12 months. Conclusion: Spontaneous resolution has been described in a high percentage of patients. Laser (micropulse and thermal) and PDT seem to lead to significant early anatomical improvement; however, there is little change beyond the first month of treatment. The real visual benefit needs further clarification
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