π+π+\pi^+\pi^+ and π+π−\pi^+\pi^- colliding in noncommutative space

By studying the scattering process of scalar particle pion on the noncommutative scalar quantum electrodynamics, the non-commutative amendment of differential scattering cross-section is found, which is dependent of polar-angle and the results are significantly different from that in the commutative scalar quantum electrodynamics, particularly when $\cos\theta\sim \pm 1$. The non-commutativity of space is expected to be explored at around $\Lambda_{NC}\sim$TeV.Comment: Latex, 12 page

Age, gender, neck circumference, and Epworth sleepiness scale do not predict obstructive sleep apnea (OSA) in moderate to severe chronic obstructive pulmonary disease (COPD): The challenge to predict OSA in advanced COPD

The combination of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) is associated with substantial morbidity and mortality. We hypothesized that predictors of OSA among patients with COPD may be distinct from OSA in the general population. Therefore, we investigated associations between traditional OSA risk factors (e.g. age), and sleep questionnaires [e.g. Epworth Sleepiness Scale] in 44 patients with advanced COPD. As a second aim we proposed a pilot, simplified screening test for OSA in patients with COPD. In a prospective, observational study of patients enrolled in the UCSD Pulmonary Rehabilitation Program we collected baseline characteristics, cardiovascular events (e.g. atrial fibrillation), and sleep questionnaires [e.g. Pittsburgh Sleep Quality Index (PSQI)]. For the pilot questionnaire, a BMI =25 kg/m2 and the presence of cardiovascular disease were used to construct the pilot screening test. Male: 59%; OSA 66%. FEV1 (mean ± SD) = 41.0±18.2% pred., FEV1/FVC = 41.5±12.7%]. Male gender, older age, and large neck circumference were not associated with OSA. Also, Epworth Sleepiness Scale and the STOP-Bang questionnaire were not associated with OSA in univariate logistic regression. In contrast, BMI =25 kg/m2 (OR = 3.94, p = 0.04) and diagnosis of cardiovascular disease (OR = 5.06, p = 0.03) were significantly associated with OSA [area under curve (AUC) = 0.74]. The pilot COPD-OSA test (OR = 5.28, p = 0.05) and STOP-Bang questionnaire (OR = 5.13, p = 0.03) were both associated with OSA in Receiver Operating Characteristics (ROC) analysis. The COPD-OSA test had the best AUC (0.74), sensitivity (92%), and specificity (83%). A tenfold cross-validation validated our results. We found that traditional OSA predictors (e.g. gender, Epworth score) did not perform well in patients with more advanced COPD. Our pilot test may be an easy to implement instrument to screen for OSA. However, a larger validation study is necessary before further clinical implementation is warranted

On the IR/UV mixing and experimental limits on the parameters of canonical noncommutative spacetimes

We investigate some issues that are relevant for the derivation of experimental limits on the parameters of canonical noncommutative spacetimes. By analyzing a simple Wess-Zumino-type model in canonical noncommutative spacetime with soft supersymmetry breaking we explore the implications of ultraviolet supersymmetry on low-energy phenomenology. The fact that new physics in the ultraviolet can modify low-energy predictions affects significantly the derivation of limits on the noncommutativity parameters based on low-energy data. These are, in an appropriate sense here discussed, ``conditional limits''. We also find that some standard techniques for an effective low-energy description of theories with non-locality at short distance scales are only applicable in a regime where theories in canonical noncommutative spacetime lack any predictivity, because of the strong sensitivity to unknown UV physics. It appears useful to combine high-energy data, from astrophysics, with the more readily available low-energy data.Comment: 14 page

Pair Production of Neutral Higgs Bosons through Noncommutative QED Interactions at Linear Colliders

We study the feasibility of detecting noncommutative (NC) QED through neutral Higgs boson (H) pair production at linear colliders (LC). This is based on the assumption that H interacts directly with photon in NCQED as suggested by symmetry considerations and strongly hinted by our previous study on \pi^0-photon interactions. We find the following striking features as compared to the standard model (SM) result: (1) generally larger cross sections for an NC scale of order 1 TeV; (2) completely different dependence on initial beam polarizations; (3) distinct distributions in the polar and azimuthal angles; and (4) day-night asymmetry due to the Earth's rotation. These will help to separate NC signals from those in the SM or other new physics at LC. We emphasize the importance of treating properly the Lorentz noninvariance problem and show how the impact of the Earth's rotation can be used as an advantage for our purpose of searching for NC signals.Comment: 12 pages, 3 figures using axodraw.sty; v2: proof version in Phys. Rev. D, minor rewordin

Vacuum configurations for renormalizable non-commutative scalar models

In this paper we find non-trivial vacuum states for the renormalizable non-commutative $\phi^4$ model. An associated linear sigma model is then considered. We further investigate the corresponding spontaneous symmetry breaking.Comment: 17 page

Fixture knowledge model development and implementation based on a functional design approach

The development of a knowledge model applied to fixture design is a complex task. The main purpose of such model is the development of a knowledge-based application to assist fixture designers. It comprises a detailed specification of the types and structures of data involved in the execution of the inference process needed to create a fixture solution for machining a raw part. A development method together with a knowledge model for automating fixture design is proposed. The development was divided into three parts: Design Process Model, definition of Top-level functional functions and Product Knowledge Model. Adopting a functional design approach, the fixture design solution was created in two levels: functional and detailed. The functional level is based on fixture functional elements and the detailed one is based on fixture commercial elements. The definitions and concepts used in the application are specified in several Units of Knowledge (UoK) that comprises the Fixture Knowledge Model. Common Knowledge Analysis and Design Structuring (CommonKADS), Methodology and software tools Oriented to KBE Applications (MOKA), Integrated DEFinition for Function Modelling (IDEF0) and Unified Modelling Language (UML) are the methodologies and techniques used in the proposed method. Finally, a prototype KBE application for fixture design was developed

Law of Genome Evolution Direction : Coding Information Quantity Grows

The problem of the directionality of genome evolution is studied. Based on the analysis of C-value paradox and the evolution of genome size we propose that the function-coding information quantity of a genome always grows in the course of evolution through sequence duplication, expansion of code, and gene transfer from outside. The function-coding information quantity of a genome consists of two parts, p-coding information quantity which encodes functional protein and n-coding information quantity which encodes other functional elements except amino acid sequence. The evidences on the evolutionary law about the function-coding information quantity are listed. The needs of function is the motive force for the expansion of coding information quantity and the information quantity expansion is the way to make functional innovation and extension for a species. So, the increase of coding information quantity of a genome is a measure of the acquired new function and it determines the directionality of genome evolution.Comment: 16 page

USP37 promotes deubiquitination of HIF2α in kidney cancer

Clear cell renal cell carcinoma (ccRCC) is characterized by loss of tumor suppressor Von Hippel Lindau (VHL) function, which leads to accumulation of hypoxia inducible factor α (including HIF1α and HIF2α). HIF2α was previously reported to be one of the major oncogenic drivers in ccRCC, however, its therapeutic targets remain challenging. Here we performed a deubiquitinase (DUB) complementary DNA (cDNA) library binding screen and discovered that ubiquitin-specific peptidase 37 (USP37) is a DUB that binds HIF2α and promotes HIF2α deubiquitination. As a result, USP37 promotes HIF2α protein stability in an enzymatically dependent manner, and depletion of USP37 leads to HIF2α down-regulation in ccRCC. Functionally, USP37 depletion causes decreased cell proliferation measured by MTS, two-dimensional (2D) colony formation as well as three-dimensional (3D) anchorage- independent growth. USP37 is also essential for maintaining kidney tumorigenesis in an orthotopic xenograft model and its depletion leads to both decreased primary kidney tumorigenesis and spontaneous lung metastasis. Our results suggest that USP37 is a potential therapeutic target in ccRCC

Generalized quantum Fokker-Planck, diffusion and Smoluchowski equations with true probability distribution functions

Traditionally, the quantum Brownian motion is described by Fokker-Planck or diffusion equations in terms of quasi-probability distribution functions, e.g., Wigner functions. These often become singular or negative in the full quantum regime. In this paper a simple approach to non-Markovian theory of quantum Brownian motion using {\it true probability distribution functions} is presented. Based on an initial coherent state representation of the bath oscillators and an equilibrium canonical distribution of the quantum mechanical mean values of their co-ordinates and momenta we derive a generalized quantum Langevin equation in $c$-numbers and show that the latter is amenable to a theoretical analysis in terms of the classical theory of non-Markovian dynamics. The corresponding Fokker-Planck, diffusion and the Smoluchowski equations are the {\it exact} quantum analogues of their classical counterparts. The present work is {\it independent} of path integral techniques. The theory as developed here is a natural extension of its classical version and is valid for arbitrary temperature and friction (Smoluchowski equation being considered in the overdamped limit).Comment: RevTex, 16 pages, 7 figures, To appear in Physical Review E (minor revision