89 research outputs found
Developments in determining the gravitational potential using toroidal functions
have shown how the integration/summation expression for the Green's function in cylindrical coordinates can be written as an azimuthal Fourier series expansion, with toroidal functions as expansion coefficients. In this paper, we show how this compact representation can be extended to other rotationally invariant coordinate systems which are known to admit separable solutions for Laplace's equation
On the influence of the cosmological constant on gravitational lensing in small systems
The cosmological constant Lambda affects gravitational lensing phenomena. The
contribution of Lambda to the observable angular positions of multiple images
and to their amplification and time delay is here computed through a study in
the weak deflection limit of the equations of motion in the Schwarzschild-de
Sitter metric. Due to Lambda the unresolved images are slightly demagnified,
the radius of the Einstein ring decreases and the time delay increases. The
effect is however negligible for near lenses. In the case of null cosmological
constant, we provide some updated results on lensing by a Schwarzschild black
hole.Comment: 8 pages, 1 figure; v2: extended discussion on the lens equation,
references added, results unchanged, in press on PR
Educator pathway project
The project, entitled Preparing a Nursing Workforce to Advance Health Services: A 3-Year Pilot
Project to Build Nursing Educator Capacity in the Health Authorities, was implemented to
address the nursing shortage by: developing nurse educator competencies through a set of
levelled educational programs, and increasing the mobility of nurse educators between the
service and academic sectors in order to increase the integration of nursing curriculum∗ and
clinical practice education. As evidenced in this report, the project met its goals and objectives
and was deemed a success after close examination of evaluation findings and program
outcomes.Applied Science, Faculty ofNursing, School ofUnreviewedFacult
Recommended from our members
Performance of the front-end signal processing electronics for the drift chambers of the Stanford Large Detector
This paper reports on the performance of the front-end analog and digital signal processing electronics for the drift chambers of the Stanford Large Detector (SLD) detector at the Stanford Linear Collider. The electronics mounted on printed circuit boards include up to 64 channels of transimpedance amplification, analog sampling, A/D conversion, and associated control circuitry. Measurements of the time resolution, gain, noise, linearity, crosstalk, and stability of the readout electronics are described and presented. The expected contribution of the electronics to the relevant drift chamber measurement resolutions (i.e., timing and charge division) is given
Influenza A virus infection dysregulates the expression of microRNA-22 and its targets; CD147 and HDAC4, in epithelium of asthmatics
Background:
Specific microRNAs (miRNAs) play essential roles in airway remodeling in asthma. Infection with influenza A virus (IAV) may also magnify pre-existing airway remodeling leading to asthma exacerbation. However, these events remain to be fully defined. We investigated the expression of miRNAs with diverse functions including proliferation (miR-20a), differentiation (miR-22) or innate/adaptive immune responses (miR-132) in primary bronchial epithelial cells (pBECs) of asthmatics following infection with the H1N1 strain of IAV.
Methods:
pBECs from subjects (n = 5) with severe asthma and non-asthmatics were cultured as submerged monolayers or at the air-liquid-interface (ALI) conditions and incubated with IAV H1N1 (MOI 5) for up to 24 h. Isolated miRNAs were subjected to Taqman miRNAs assays. We confirmed miRNA targets using a specific mimic and antagomir. Taqman mRNAs assays and immunoblotting were used to assess expression of target genes and proteins, respectively.
Results:
At baseline, these miRNAs were expressed at the same level in pBECs of asthmatics and non-asthmatics. After 24Â h of infection, miR-22 expression increased significantly which was associated with the suppression of CD147 mRNA and HDAC4 mRNA and protein expression in pBECs from non-asthmatics, cultured in ALI. In contrast, miR-22 remained unchanged while CD147 expression increased and HDAC4 remained unaffected in cells from asthmatics. IAV H1N1 mediated increases in SP1 and c-Myc transcription factors may underpin the induction of CD147 in asthmatics.
Conclusion:
The different profile of miR-22 expression in differentiated epithelial cells from non-asthmatics may indicate a self-defense mechanism against aberrant epithelial responses through suppressing CD147 and HDAC4, which is compromised in epithelial cells of asthmatics.Medicine, Faculty ofNon UBCAnesthesiology, Pharmacology and Therapeutics, Department ofReviewedFacult
Differential rotation of epsilon eridani detected by most
The Microvariability and Oscillations of STars (MOST) photometric satellite observed three rotations of e Eri continuously in late 2005. We detected two spots (?m ~ 0.01) at different latitudes (20°.0, 31°.5) revolving with different periods (11.35 days, 11.55 days), from which we derive a differential rotation coefficient, k = 0.11-0.2+.03, in agreement with the prediction by Brown and coworkers for a young Sun-like star having roughly twice the solar angular velocity. The light curve was analyzed with the program StarSpotz, a modification of SPOTMODEL by RibaŽrik and coworkers. The best-fitting value for the inclination angle i = 30° 3° is compatible with inclinations already estimated for the disk (~25°) and planetary orbit (26°.2). The inclination also leads to an equatorial rotation speed of 3.42 km s-1 and the photometric value of v sin i = 1.7 km s-1. When compared with spectroscopically determined values, the photometric v sin i allows, in principle, an independent estimate of the macroturbulent velocity. Both spots would have distorted the radial velocity curve ~10 m s-1 by the Rossiter-McLaughlin effect, which is similar to the stellar radial velocity "noise" detected by others. Details of the StarSpotz model and of the uniqueness tests that we applied in order to arrive at a best solution and realistic estimates of errors in the derived parameters are given. 2006. The American Astronomical Society. All rights reserved
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