4,381 research outputs found
Hypomagnesemia: a clinical perspective
No full textPhuong-Chi T Pham,1 Phuong-Anh T Pham,2 Son V Pham,3 Phuong-Truc T Pham,4 Phuong-Mai T Pham,5 Phuong-Thu T Pham61Olive View–UCLA Medical Center, Los Angeles, CA, USA; 2Veterans Administration Central California Health Care System, Fresno, CA, USA; 3South Texas Veterans Health Care System and University of Texas Health Science Center, San Antonio, TX, USA; 4Pennsylvania State University Wilkes-Barre, Lehman, PA, USA; 5Greater Los Angeles Veterans Administration, Sepulveda, CA, USA; 6David Geffen School of Medicine at UCLA, Los Angeles, CA, USAAbstract: Although magnesium is involved in a wide spectrum of vital functions in normal human physiology, the significance of hypomagnesemia and necessity for its treatment are under-recognized and underappreciated in clinical practice. In the current review, we first present an overview of the clinical significance of hypomagnesemia and normal magnesium metabolism, with a focus on renal magnesium handling. Subsequently, we review the literature for both congenital and acquired hypomagnesemic conditions that affect the various steps in normal magnesium metabolism. Finally, we present an approach to the routine evaluation and suggested management of hypomagnesemia.Keywords: hypomagnesemia, magnesium, diabetes mellitus, alcohol, TRPM6, cisplati
A PC parallel port button box provides millisecond response time accuracy under Linux
No full textFor psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
Millisecond accuracy video display using OpenGL under Linux
No full textTo measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
Frontmatter (Titlepage, Table of Contents, Author List, PC List, Reviewer List)
No full textFront matter including table of contents, author list, PC list, and reviewer list
ESTIMATION OF THE LOCAL MASS DENSITY FROM AN F-STAR SAMPLE OBSERVED BY HIPPARCOS H.A. Pham
No full textThis work is dedicated to the determination of the local mass density from an F-stars sample observed by Hipparcos. We present here a maximum likelihood method in order to estimate the scale height of a tracer sample together with the Sun height. This method takes into account the limiting apparent magnitude of the tracer sample. Applying this method on a sample of F stars observed by Hipparcos, we find a scale height of 165 \Sigma 5 pc. The estimated sun height is 9 \Sigma 4 pc. The local volume mass density is 0:11 \Sigma 0:01 M fi pc \Gamma3 . Key words: local volume mass density; scale height; Sun height; likelihood maximum method; apparent magnitude censorship. 1. INTRODUCTION Since the first dynamical determinations of the local mass density, performed by Kapteyn (1922) and by Oort (1932), many other studies have been carried out, leading to values between 0.09 and 0.28 M fi pc \Gamma3 . As the observed local mass density is 0.10 M fi pc \Gamma3 , these dynamical determinat..
High efficiency implementation of PC and PC stable algorithms yields three-dimensional graphs of information flow for the Earth' atmosphere
No full textSeptember 3, 2014.Causal discovery algorithms have recently been applied to several climate applications. In particular, in prior work we have developed methods to recover pathways of interaction in the global climate system, using the classic PC algorithm. However, standard implementations of the PC algorithm cannot handle the large number of variables and temporal models required for this application. This technical report shows that a more efficient implementation of the PC algorithm can provide speed gains of a factor of 1,000 or more. This in turn enables us to calculate graphs of information flow with much higher resolution grids. Furthermore, we can now - for the first time ever - calculate information flow graphs that extend over three dimensions, i.e. rather than just including one layer of the planet's atmosphere we can now capture interactions across several height layers
State variable simulation package for IBM-PC
No full textThis thesis was scanned from the print manuscript for digital preservation and is copyright the author.
Researchers can access this thesis by asking their local university, institution or public library to
make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
Degradation of bisphenol-a-polycarbonate (BPA-PC) optical lenses under simulated harsh environment conditions
No full textThis paper investigates degradation and failure mechanisms of BPA-PC lenses in simulated harsh environment conditions. Exposure of secondary optics in Light Emitting Diode LED-based systems or any other similar applications to environmental stresses can adversely effect the performance and lifetime of products. This paper simulates a harsh environment condition, using a salt bath oven. Salt spray exposure/ageing tests at 45° C were carried out up to four months. Fourier transform infrared-attenuated total reflection FTIR-ATR spectrometer and Lambda 950 Ultraviolet-Visible (UV-VIS) spectrophotometer were used to study the optical and chemical characteristics of aged plates. Results showed that salt bath exposure test resulted in the severe deterioration of optical characteristics BPA-PC samples. Degradation of optical properties of BPA-PC plates is attributable to the oxidation of samples.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Heavy pentaquark states Pc(4380) and Pc(4450) in the J/ψ production induced by pion beams off the nucleon
No full textAbstractIn this study, we investigate the J/ψ production induced by pion beams off the nucleon, particularly the heavy pentaquarks Pc(4380) and Pc(4450) in intermediate states, based on a hybridized Regge model. The process involving ρ and π meson exchange in the t channel is considered as background, and the heavy pentaquark exchange is included in the s channel. The coupling constants such as the ρNN and πNN vertices are taken from the NN potentials, whereas those for the J/ψρπ and J/ψππ vertices are determined by using experimental data based on the branching ratios. In order to estimate the Pc(4380) and Pc(4450) coupling constants, we use the experimental upper limit on the total cross section as a guide for the πN→J/ψN reaction. The background total cross section is the order of 10−4–10−3 nb. In the vicinity of the heavy pentaquark masses, the total cross section reaches about 1 nb
Data Assimilation for Full 4D PC-MRI Measurements: Physics-Based Denoising and Interpolation
No full textPhase-Contrast Magnetic Resonance Imaging (PC-MRI) surpasses all other imaging methods in quality and completeness for measuring time-varying volumetric blood flows and has shown potential to improve both diagnosis and risk assessment of cardiovascular diseases. However, like any measurement of physical phenomena, the data are prone to noise, artefacts and has a limited resolution. Therefore, PC-MRI data itself do not fulfil physics fluid laws making it difficult to distinguish important flow features. For data analysis, physically plausible and high-resolution data are required. Computational fluid dynamics provides high-resolution physically plausible flows. However, the flow is inherently coupled to the underlying anatomy and boundary conditions, which are difficult or sometimes even impossible to adequately model with current techniques. We present a novel methodology using data assimilation techniques for PC-MRI noise and artefact removal, generating physically plausible flow close to the measured data. It also allows us to increase the spatial and temporal resolution. To avoid sensitivity to the anatomical model, we consider and update the full 3D velocity field. We demonstrate our approach using phantom data with various amounts of induced noise and show that we can improve the data while preserving important flow features, without the need of a highly detailed model of the anatomy.Computer Graphics and Visualisatio
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