Brief studies of turbojet combustor and fuel-system operation with hydrogen fuel at -400 deg f

Turbojet combustor and fuel system operation with hydrogen fuel at -400 deg

Mammalian oocytes are targets for prostaglandin E2 (PGE2) action

<p>Abstract</p> <p>Background</p> <p>The ovulatory gonadotropin surge increases synthesis of prostaglandin E2 (PGE2) by the periovulatory follicle. PGE2 actions on granulosa cells are essential for successful ovulation. The aim of the present study is to determine if PGE2 also acts directly at the oocyte to regulate periovulatory events.</p> <p>Methods</p> <p>Oocytes were obtained from monkeys and mice after ovarian follicular stimulation and assessed for PGE2 receptor mRNA and proteins. Oocytes were cultured with vehicle or PGE2 and assessed for cAMP generation, resumption of meiosis, and in vitro fertilization.</p> <p>Results</p> <p>Germinal vesicle intact (GV) oocytes from both monkeys and mice expressed mRNA for the PGE2 receptors EP2, EP3, and EP4. EP2 and EP4 proteins were detected by confocal microscopy in oocytes of both species. Monkey and mouse oocytes responded to PGE2 as well as agonists selective for EP2 and EP4 receptors with elevated cAMP, consistent with previous identification of EP2 and EP4 as Gαs/adenylyl cyclase coupled receptors. Incubation of mouse GV stage oocytes with PGE2 delayed oocyte nuclear maturation in vitro, but PGE2 treatment did not alter the percentage of mouse oocytes that fertilized successfully. PGE2 treatment also decreased the percentage of monkey oocytes that resumed meiosis in vitro. In contrast with mouse oocytes, the percentage of monkey oocytes which fertilized in vitro was lower after treatment with PGE2. Monkey oocytes with intact cumulus showed delayed nuclear maturation, but fertilization rate was not affected by PGE2 treatment.</p> <p>Conclusions</p> <p>Monkey and mouse oocytes express functional PGE2 receptors. PGE2 acts directly at mammalian oocytes to delay nuclear maturation. Surrounding cumulus cells modulate the effect of PGE2 to alter subsequent fertilization.</p

Irreversible Quantum Mechanics in the Neutral K-System

The neutral Kaon system is used to test the quantum theory of resonance scattering and decay phenomena. The two dimensional Lee-Oehme-Yang theory with complex Hamiltonian is obtained by truncating the complex basis vector expansion of the exact theory in Rigged Hilbert space. This can be done for K_1 and K_2 as well as for K_S and K_L, depending upon whether one chooses the (self-adjoint, semi-bounded) Hamiltonian as commuting or non-commuting with CP. As an unexpected curiosity one can show that the exact theory (without truncation) predicts long-time 2 pion decays of the neutral Kaon system even if the Hamiltonian conserves CP.Comment: 36 pages, 1 PostScript figure include

General analysis of time evolution of decay spectrum in B^0 -> pi^+ pi^- l^+ l^-

Using the general, model independent form of effective Hamiltonian, the decay spectrum of B^0 -> pi^+ pi^- l^+ l^- decay is studied. The sensitivity of experimentally measurable asymmetries to the new Wilson coefficients and time is studied. It is observed that different asymmetries are sensitive to the new Wilson coefficients and they can serve as an efficient tool for establishing new physics beyond SM.Comment: 15 pp, 4 figures (postscript formatted), LaTex formatte

T violation and the unidirectionality of time

An increasing number of experiments at the Belle, BNL, CERN, DA{\Phi}NE and SLAC accelerators are confirming the violation of time reversal invariance (T). The violation signifies a fundamental asymmetry between the past and future and calls for a major shift in the way we think about time. Here we show that processes which violate T symmetry induce destructive interference between different paths that the universe can take through time. The interference eliminates all paths except for two that represent continuously forwards and continuously backwards time evolution. Evidence from the accelerator experiments indicates which path the universe is effectively following. This work may provide fresh insight into the long-standing problem of modeling the dynamics of T violation processes. It suggests that T violation has previously unknown, large-scale physical effects and that these effects underlie the origin of the unidirectionality of time. It may have implications for the Wheeler-DeWitt equation of canonical quantum gravity. Finally it provides a view of the quantum nature of time itself.Comment: 24 pages, 5 figures. Final version accepted for publishing in Foundations of Physics. The final publication is available at http://www.springerlink.com/content/y3h4174jw2w78322

Sputum microbiome profiling in COPD: beyond singular pathogen detection.

Culture-independent microbial sequencing techniques have revealed that the respiratory tract harbours a complex microbiome not detectable by conventional culturing methods. The contribution of the microbiome to chronic obstructive pulmonary disease (COPD) pathobiology and the potential for microbiome-based clinical biomarkers in COPD are still in the early phases of investigation. Sputum is an easily obtainable sample and has provided a wealth of information on COPD pathobiology, and thus has been a preferred sample type for microbiome studies. Although the sputum microbiome likely reflects the respiratory microbiome only in part, there is increasing evidence that microbial community structure and diversity are associated with disease severity and clinical outcomes, both in stable COPD and during the exacerbations. Current evidence has been limited to mainly cross-sectional studies using 16S rRNA gene sequencing, attempting to answer the question 'who is there?' Longitudinal studies using standardised protocols are needed to answer outstanding questions including differences between sputum sampling techniques. Further, with advancing technologies, microbiome studies are shifting beyond the examination of the 16S rRNA gene, to include whole metagenome and metatranscriptome sequencing, as well as metabolome characterisation. Despite being technically more challenging, whole-genome profiling and metabolomics can address the questions 'what can they do?' and 'what are they doing?' This review provides an overview of the basic principles of high-throughput microbiome sequencing techniques, current literature on sputum microbiome profiling in COPD, and a discussion of the associated limitations and future perspectives

Atrial fibrillation impairs the diagnostic performance of cardiac natriuretic peptides in dyspneic patients. results from the BACH Study (Biomarkers in ACute Heart Failure)

Objectives: The purpose of this study was to assess the impact of atrial fibrillation (AF) on the performance of mid-region amino terminal pro-atrial natriuretic peptide (MR-proANP) in comparison with the B-type peptides (BNP and NT-proBNP) for diagnosis of acute heart failure (HF) in dyspneic patients. Background: The effects of AF on the diagnostic and prognostic performance of MR-proANP in comparison with the B type natriuretic peptides have not been previously reported. Methods: A total of 1,445 patients attending the emergency department with acute dyspnea had measurements taken of MR-proANP, BNP, and NT-proBNP values on enrollment to the BACH trial and were grouped according to presence or absence of AF and HF. Results: AF was present in 242 patients. Plasma concentrations of all three peptides were lowest in those with neither AF nor HF and AF without HF was associated with markedly increased levels (p &lt; 0.00001). HF with or without AF was associated with a significant further increment (p &lt; 0.00001 for all three markers). Areas under receiver operator characteristic curves (AUCs) for discrimination of acute HF were similar and powerful for all peptides without AF (0.893 to 0.912; all p &lt; 0.001) with substantial and similar reductions (0.701 to 0.757) in the presence of AF. All 3 peptides were independently prognostic but there was no interaction between any peptide and AF for prediction of all-cause mortality. Conclusions: AF is associated with increased plasma natriuretic peptide (MR-proANP, BNP and NT-proBNP) levels in the absence of HF. The diagnostic performance of all three peptides is impaired by AF. This warrants consideration of adjusted peptide thresholds for diagnostic use in AF and mandates the continued search for markers free of confounding by AF

Time Reversal Violation from the entangled B0-antiB0 system

We discuss the concepts and methodology to implement an experiment probing directly Time Reversal (T) non-invariance, without any experimental connection to CP violation, by the exchange of "in" and "out" states. The idea relies on the B0-antiB0 entanglement and decay time information available at B factories. The flavor or CP tag of the state of the still living neutral meson by the first decay of its orthogonal partner overcomes the problem of irreversibility for unstable systems, which prevents direct tests of T with incoherent particle states. T violation in the time evolution between the two decays means experimentally a difference between the intensities for the time-ordered (l^+ X, J/psi K_S) and (J/psi K_L, l^- X) decays, and three other independent asymmetries. The proposed strategy has been applied to simulated data samples of similar size and features to those currently available, from which we estimate the significance of the expected discovery to reach many standard deviations.Comment: 17 pages, 2 figures, 6 table