2,312 research outputs found
Classicalization and Unitarity
We point out that the scenario for UV completion by "classicalization",
proposed recently is in fact Wilsonian in the classical Wilsonian sense. It
corresponds to the situation when a field theory has a nontrivial UV fixed
point governed by a higher dimensional operator. Provided the kinetic term is a
relevant operator around this point the theory will flow in the IR to the free
scalar theory. Physically, "classicalization", if it can be realized, would
correspond to a situation when the fluctuations of the field operator in the UV
are smaller than in the IR. As a result there exists a clear tension between
the "classicalization" scenario and constraints imposed by unitarity on a
quantum field theory, making the existence of classicalizing unitary theories
questionable.Comment: Some clarifications and refs added. Accepted as a JHEP publication;
12 page
Genome-Wide Methylation Profiling in 229 Patients With Crohn's Disease Requiring Intestinal Resection: Epigenetic Analysis of the Trial of Prevention of Post-operative Crohn's Disease (TOPPIC).
Background & Aims: DNA methylation alterations may provide important insights into gene-environment interaction in cancer, aging, and complex diseases, such as inflammatory bowel disease (IBD). We aim first to determine whether the circulating DNA methylome in patients requiring surgery may predict Crohn's disease (CD) recurrence following intestinal resection; and second to compare the circulating methylome seen in patients with established CD with that we had reported in a series of inception cohorts. Methods: TOPPIC was a placebo-controlled, randomized controlled trial of 6-mercaptopurine at 29 UK centers in patients with CD undergoing ileocolic resection between 2008 and 2012. Genomic DNA was extracted from whole blood samples from 229 of the 240 patients taken before intestinal surgery and analyzed using 450KHumanMethylation and Infinium Omni Express Exome arrays (Illumina, San Diego, CA). Coprimary objectives were to determine whether methylation alterations may predict clinical disease recurrence; and to assess whether the epigenetic alterations previously reported in newly diagnosed IBD were present in the patients with CD recruited into the TOPPIC study. Differential methylation and variance analysis was performed comparing patients with and without clinical evidence of recurrence. Secondary analyses included investigation of methylation associations with smoking, genotype (MeQTLs), and chronologic age. Validation of our previously published case-control observation of the methylome was performed using historical control data (CD, n = 123; Control, n = 198). Results: CD recurrence in patients following surgery is associated with 5 differentially methylated positions (Holm P <.05), including probes mapping to WHSC1 (P = 4.1 × 10 -9, Holm P =.002) and EFNA3 (P = 4.9 × 10 -8, Holm P =.02). Five differentially variable positions are demonstrated in the group of patients with evidence of disease recurrence including a probe mapping to MAD1L1 (P = 6.4 × 10 -5). DNA methylation clock analyses demonstrated significant age acceleration in CD compared with control subjects (GrimAge + 2 years; 95% confidence interval, 1.2–2.7 years), with some evidence for accelerated aging in patients with CD with disease recurrence following surgery (GrimAge +1.04 years; 95% confidence interval, -0.04 to 2.22). Significant methylation differences between CD cases and control subjects were seen by comparing this cohort in conjunction with previously published control data, including validation of our previously described differentially methylated positions (RPS6KA2 P = 1.2 × 10 -19, SBNO2 = 1.2 × 10 -11) and regions (TXK [false discovery rate, P = 3.6 × 10 -14], WRAP73 [false discovery rate, P = 1.9 × 10 -9], VMP1 [false discovery rate, P = 1.7 × 10 -7], and ITGB2 [false discovery rate, P = 1.4 × 10 -7]). Conclusions: We demonstrate differential methylation and differentially variable methylation in patients developing clinical recurrence within 3 years of surgery. Moreover, we report replication of the CD-associated methylome, previously characterized only in adult and pediatric inception cohorts, in patients with medically refractory disease needing surgery.</p
The Orbital Structure of Triaxial Galaxies with Figure Rotation
We survey the properties of all orbit families in the rotating frame of a
family of realistic triaxial potentials with central supermassive black holes
(SMBHs). In such galaxies, most regular box orbits (vital for maintaining
triaxiality) are associated with resonances which occupy two-dimensional
surfaces in configuration space. For slow figure rotation all orbit families
are largely stable. At intermediate pattern speeds a significant fraction of
the resonant box orbits as well as inner long-axis tubes are destabilized by
the "envelope doubling" that arises from the Coriolis forces and are driven
into the destabilizing center. Thus, for pattern rotation periods .2 Gyr < Tp <
5 Gyr, the two orbit families that are most important for maintaining
triaxiality are highly chaotic. As pattern speed increases there is also a
sharp decrease in the overall fraction of prograde short-axis tubes and a
corresponding increase in the retrograde variety. At the highest pattern speeds
(close to that of triaxial bars), box-like orbits undergo a sudden transition
to a new family of stable retrograde loop-like orbits, which resemble orbits in
three-dimensional bars, and circulate about the short axis. Our analysis
implies that triaxial systems (with central cusps and SMBHs) can either have
high pattern speeds like fast bars or low patten speeds like triaxial
elliptical galaxies or dark matter halos found in N-body simulations.
Intermediate pattern speeds produce a high level of stochasticity in both the
box and inner long-axis tube orbit families implying that stable triaxial
systems are unlikely to have such pattern speeds.Comment: Version accepted for publication in ApJ, Vol 727, Feb. 1 issue, 201
Serum Calprotectin - A novel diagnostic and prognostic marker in Inflammatory Bowel Diseases
OBJECTIVES:
There is an unmet need for novel blood-based biomarkers that offer timely and accurate diagnostic and prognostic testing in inflammatory bowel diseases (IBD). We aimed to investigate the diagnostic and prognostic utility of serum calprotectin (SC) in IBD.
METHODS:
A total of 171 patients (n=96 IBD, n=75 non-IBD) were prospectively recruited. A multi-biomarker model was derived using multivariable logistic regression analysis. Cox proportional hazards model was derived to assess the contribution of each variable to disease outcomes.
RESULTS:
SC correlated strongly with current biomarkers, including fecal calprotectin (FC) (n=50, ρ=0.50, P=1.6 × 10−4). SC was the strongest individual predictor of IBD diagnosis (odds ratio (OR): 9.37 (95% confidence interval (CI): 2.82–34.68), P=4.00 × 10−4) compared with other markers (C-reactive protein (CRP): OR 8.52 (95% CI: 2.75–28.63), P=2.80 × 10−4); albumin: OR 6.12 (95% CI: 1.82–22.16), P=0.004). In a subset of 50 patients with paired SC and FC, the area under receiver operating characteristic discriminating IBD from controls was better for FC than for SC (0.99, (95% CI 0.87–1.00) and 0.87 (95% CI:0.78–0.97), respectively; P=0.01). At follow-up (median 342 days; interquartile range: 88–563), SC predicted treatment escalation and/or surgery in IBD (hazard ratio (HR) 2.7, 95% CI: 1.1–4.9), in particular Crohn’s disease (CD) (HR 4.2, 95% CI 1.2–15.3). A model incorporating SC and either CRP or albumin has a positive likelihood ratio of 24.14 for IBD. At 1 year, our prognostic model can predict treatment escalation in IBD in 65% of cases (95% CI: 43–79%) and 80% (95% CI: 31–94%) in CD if ≥2 blood marker criteria are met.
CONCLUSIONS:
A diagnostic and prognostic model that combines SC and other blood-based biomarkers accurately predicts the inflammatory burden in IBD and has the potential to predict disease and its outcomes. Our data warrant further detailed exploration and validation in large multicenter cohorts
Thermodynamics of the N=2^* strongly coupled plasma
Gauge/string duality is a potentially important framework for addressing the
properties of the strongly coupled quark gluon plasma produced at RHIC.
However, constructing an actual string theory dual to QCD has so far proven
elusive. In this paper, we take a partial step towards exploring the QCD plasma
by investigating the thermodynamics of a non-conformal system, namely the N=2^*
theory, which is obtained as a mass deformation of the conformal N=4 gauge
theory. We find that at temperatures of order the mass scale, the
thermodynamics of the mass deformed plasma is surprisingly close to that of the
conformal gauge theory plasma. This suggests that many properties of the quark
gluon plasma at RHIC may in fact be well described by even relatively simple
models such as that of the conformal N=4 plasma.Comment: 41 pages, 22 figure
Can inflationary models of cosmic perturbations evade the secondary oscillation test?
We consider the consequences of an observed Cosmic Microwave Background (CMB)
temperature anisotropy spectrum containing no secondary oscillations. While
such a spectrum is generally considered to be a robust signature of active
structure formation, we show that such a spectrum {\em can} be produced by
(very unusual) inflationary models or other passive evolution models. However,
we show that for all these passive models the characteristic oscillations would
show up in other observable spectra. Our work shows that when CMB polarization
and matter power spectra are taken into account secondary oscillations are
indeed a signature of even these very exotic passive models. We construct a
measure of the observability of secondary oscillations in a given experiment,
and show that even with foregrounds both the MAP and \pk satellites should be
able to distinguish between models with and without oscillations. Thus we
conclude that inflationary and other passive models can {\em not} evade the
secondary oscillation test.Comment: Final version accepted for publication in PRD. Minor improvements
have been made to the discussion and new data has been included. The
conclusions are unchagne
Prostate cancer arising in ectopic prostatic tissue within the left seminal vesicle: a rare case diagnosed with multi-parametric magnetic resonance imaging and magnetic resonance imaging-transrectal ultrasound fusion biopsy
Altered DNA methylation within DNMT3A, AHRR, LTA/TNF loci mediates the effect of smoking on inflammatory bowel disease
This work aims to investigate how smoking exerts effect on the development of inflammatory bowel disease (IBD). A prospective cohort study and a Mendelian randomization study are first conducted to evaluate the association between smoking behaviors, smoking-related DNA methylation and the risks of Crohn’s disease (CD) and ulcerative colitis (UC). We then perform both genome-wide methylation analysis and co-localization analysis to validate the observed associations. Compared to never smoking, current and previous smoking habits are associated with increased CD (P = 7.09 × 10−10) and UC (P < 2 × 10−16) risk, respectively. DNA methylation alteration at cg17742416 [DNMT3A] is linked to both CD (P = 7.30 × 10−8) and UC (P = 1.04 × 10−4) risk, while cg03599224 [LTA/TNF] is associated with CD risk (P = 1.91 × 10−6), and cg14647125 [AHRR] and cg23916896 [AHRR] are linked to UC risk (P = 0.001 and 0.002, respectively). Our study identifies biological mechanisms and pathways involved in the effects of smoking on the pathogenesis of IBD
RNA splicing is a key mediator of tumour cell plasticity and a therapeutic vulnerability in colorectal cancer
Tumour cell plasticity is a major barrier to the efficacy of targeted cancer therapies but the mechanisms that mediate it are poorly understood. Here, we identify dysregulated RNA splicing as a key driver of tumour cell dedifferentiation in colorectal cancer (CRC). We find that Apc-deficient CRC cells have dysregulated RNA splicing machinery and exhibit global rewiring of RNA splicing. We show that the splicing factor SRSF1 controls the plasticity of tumour cells by controlling Kras splicing and is required for CRC invasion in a mouse model of carcinogenesis. SRSF1 expression maintains stemness in human CRC organoids and correlates with cancer stem cell marker expression in human tumours. Crucially, partial genetic downregulation of Srsf1 does not detrimentally affect normal tissue homeostasis, demonstrating that tumour cell plasticity can be differentially targeted. Thus, our findings link dysregulation of the RNA splicing machinery and control of tumour cell plasticity
- …