2,086 research outputs found
Type II Seesaw Dominance in Non-supersymmetric and Split Susy SO(10) and Proton Life Time
Recently type II seesaw dominance in a supersymmetric SO(10) framework has
been found useful in explaining large solar and atmospheric mixing angles as
well as larger values of while unifying quark and lepton masses.
An important question in these models is whether there exists consistency
between coupling unification and type II seesaw dominance. Scenarios where this
consistency can be demonstrated have been given in a SUSY framework. In this
paper we give examples where type II dominance occurs in SO(10) models without
supersymmetry but with additional TeV scale particles and also in models with
split-supersummetry. Grand unification is realized in a two-step process via
breaking of SO(10) to SU(5) and then to a TeV scale standard model supplemented
by extra fields and an SU(5) Higgs multiplet at a scale about
GeV to give type-II seesaw. The predictions for proton lifetime in
these models are in the range yrs. to yrs.. A number of recent numerical fits to GUT-scale fermion
masses can be accommodated within this model.Comment: 7 pages LaTeX, 3 figures, related areas: hep-ex, hep-th, astro-ph;
Reference added, typo corrected, version to appear in Physical Review
An Experimental Study and Database for Tip Vortex Flow From an Airfoil
An experimental investigation of tip vortices from a NACA0012 airfoil is conducted in a low-speed wind tunnel at a chord Reynolds number (Rc) of 410(exp 4 ). Data for the stationary airfoil at various angles of attack (alpha) are first discussed. Detailed flow-field surveys are done for two cases: alpha = 10deg with attached flow and alpha = 25deg with massive flow separation. Data include mean velocity, streamwise vorticity, and turbulent stresses at various streamwise locations. For all cases, the vortex core is seen to involve a mean velocity deficit. The deficits in these cases trace to the airfoil wake, part of which gets wrapped up by the tip vortex. Comparison with data from the literature suggests that with increasing Rc, the deficit turns into an excess, with the transition occurring in the approximate Rc range of 210(exp 5) to 510(exp 5). Survey results for various shapes of the airfoil wingtip are then presented. The shapes include square and rounded ends and a number of winglet designs. Finally, data under sinusoidal pitching condition, for the airfoil with square ends, are documented. All pitching cases pertain to a mean alpha = 15deg, while the amplitude and frequency are varied. Amplitudes of +/-5deg, +/-10deg, and +/-15deg and reduced frequencies k = 0.08, 0.2, and 0.33 are covered. Digital records of all data and some of the hardware design are made available on a supplemental CD with the electronic version of the paper for those interested in numerical simulation
Statistical Mechanics of the Chinese Restaurant Process: lack of self-averaging, anomalous finite-size effects and condensation
The Pitman-Yor, or Chinese Restaurant Process, is a stochastic process that
generates distributions following a power-law with exponents lower than two, as
found in a numerous physical, biological, technological and social systems. We
discuss its rich behavior with the tools and viewpoint of statistical
mechanics. We show that this process invariably gives rise to a condensation,
i.e. a distribution dominated by a finite number of classes. We also evaluate
thoroughly the finite-size effects, finding that the lack of stationary state
and self-averaging of the process creates realization-dependent cutoffs and
behavior of the distributions with no equivalent in other statistical
mechanical models.Comment: (5pages, 1 figure
Mirror Symmetry and a Flop
By applying mirror symmetry to D-branes in a Calabi-Yau geometry we shed
light on a flop in M-theory relevant for large dualities in supersymmetric gauge theories. Furthermore, we derive superpotential for
M-theory on corresponding manifolds for all A-D-E cases. This provides an
effective method for geometric engineering of gauge theories for
which mirror symmetry gives exact information about vacuum geometry. We also
find a number of interesting dual descriptions.Comment: Identification of parameters as well as the computation of the
superpotential is extended to all A-D-E cases. Additional references are also
include
Femtosecond photonic viral inactivation probed using solid-state nanopores
We report on detection of virus inactivation using femtosecond laser radiation by measuring the
conductance of a solid state nanopore designed for detecting single particles. Conventional methods
of assaying for viral inactivation based on plaque forming assays require 24–48 h for bacterial growth.
Nanopore conductance measurements provide information on morphological changes at a single
virion level.We show that analysis of a time series of nanopore conductance can quantify the detection
of inactivation, requiring only a few minutes from collection to analysis. Morphological changes were
verified by dynamic light scattering. Statistical analysis maximizing the information entropy provides
a measure of the log reduction value. This work provides a rapid method for assaying viral inactivation
with femtosecond lasers using solid-state nanopores.First author draf
Advanced age and left atrial enlargement predict postoperative atrial fibrillation in patients undergoing cardiac valve surgery
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Autophagy gene haploinsufficiency drives chromosome instability, increases migration, and promotes early ovarian tumors.
Autophagy, particularly with BECN1, has paradoxically been highlighted as tumor promoting in Ras-driven cancers, but potentially tumor suppressing in breast and ovarian cancers. However, studying the specific role of BECN1 at the genetic level is complicated due to its genomic proximity to BRCA1 on both human (chromosome 17) and murine (chromosome 11) genomes. In human breast and ovarian cancers, the monoallelic deletion of these genes is often co-occurring. To investigate the potential tumor suppressor roles of two of the most commonly deleted autophagy genes in ovarian cancer, BECN1 and MAP1LC3B were knocked-down in atypical (BECN1+/+ and MAP1LC3B+/+) ovarian cancer cells. Ultra-performance liquid chromatography mass-spectrometry metabolomics revealed reduced levels of acetyl-CoA which corresponded with elevated levels of glycerophospholipids and sphingolipids. Migration rates of ovarian cancer cells were increased upon autophagy gene knockdown. Genomic instability was increased, resulting in copy-number alteration patterns which mimicked high grade serous ovarian cancer. We further investigated the causal role of Becn1 haploinsufficiency for oncogenesis in a MISIIR SV40 large T antigen driven spontaneous ovarian cancer mouse model. Tumors were evident earlier among the Becn1+/- mice, and this correlated with an increase in copy-number alterations per chromosome in the Becn1+/- tumors. The results support monoallelic loss of BECN1 as permissive for tumor initiation and potentiating for genomic instability in ovarian cancer
Validation of the lupus nephritis clinical indices in childhood-onset systemic lupus erythematosus
OBJECTIVE: To validate clinical indices of lupus nephritis (LN) activity and damage when used in children against the criterion standard of kidney biopsy findings. METHODS: In 83 children requiring kidney biopsy the SLE Disease Activity Index Renal Domain (SLEDAI-R); British Isles Lupus Assessment Group index Renal Domain (BILAG-R), Systemic Lupus International Collaborating Clinics Renal Activity (SLICC-RAS) and Damage Index Renal Domain (SDI-R) were measured. Fixed effect and logistic models were done to predict International Society of Nephrology/Renal Pathology Society (ISN/RPS) class; low/moderate vs. high LN-activity [NIH Activity Index (NIH-AI) score:10; Tubulointerstitial Activity Index (TIAI) score:5) or the absence vs. presence of LN chronicity [NIH Chronicity Index (NIH-CI) score: 0 vs. \u3e/= 1]. RESULTS: There were 10, 50 and 23 patients with class I/II, III/IV and V, respectively. Scores of the clinical indices did not differentiate among patients by ISN/RPS class. The SLEDAI-R and SLICC-RAS but not the BILAG-R differed with LN-activity status defined by NIH-AI scores, while only the SLEDAI-R scores differed between LN-activity status based on TIAI scores. The sensitivity and specificity of the SDI-R to capture LN chronicity was 23.5% and 91.7%, respectively. Despite designed to measure LN-activity, SLICC-RAS and SLEDAI-R scores significantly differed with LN chronicity status. CONCLUSION: Current clinical indices of LN fail to discriminate ISN/RPS Class in children. Despite its shortcomings, the SLEDAI-R appears to best for measuring LN activity in a clinical setting. The SDI-R is a poor correlate of LN chronicity. This article is protected by copyright. All rights reserved
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