1,310 research outputs found
Raman Characterization Studies Of Synthetic And Natural Mgal 2o4 Crystals
Raman studies are reported for one natural and four synthetic MgAl 2O4 spinel crystals and symmetry assignments for the phonon modes of the spinel crystal structure are given. Deviations in the Raman selection rules are observed for the synthetic spinel crystals in the form of additional modes over and above those theoretically predicted. Also, detailed studies of one of the synthetic crystals show a probable disordering in the Mg-Al sites. Raman linewidths and violations of selection rules, as reported here, can aid in the characterization and quality control of synthetically grown crystals.5893585359
Canonical lossless state-space systems: Staircase forms and the Schur algorithm
A new finite atlas of overlapping balanced canonical forms for multivariate
discrete-time lossless systems is presented. The canonical forms have the
property that the controllability matrix is positive upper triangular up to a
suitable permutation of its columns. This is a generalization of a similar
balanced canonical form for continuous-time lossless systems. It is shown that
this atlas is in fact a finite sub-atlas of the infinite atlas of overlapping
balanced canonical forms for lossless systems that is associated with the
tangential Schur algorithm; such canonical forms satisfy certain interpolation
conditions on a corresponding sequence of lossless transfer matrices. The
connection between these balanced canonical forms for lossless systems and the
tangential Schur algorithm for lossless systems is a generalization of the same
connection in the SISO case that was noted before. The results are directly
applicable to obtain a finite sub-atlas of multivariate input-normal canonical
forms for stable linear systems of given fixed order, which is minimal in the
sense that no chart can be left out of the atlas without losing the property
that the atlas covers the manifold
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Failure rate analysis using GLIMMIX
This paper illustrates use of a recently developed SAS macro, GLIMMIX, for implementing an analysis suggested by Wolfinger and O`Connell (1993) in modeling failure count data with random as well as fixed factor effects. Interest in this software tool arose from consideration of modernizing the Failure Rate Analysis Code (FRAC), developed at Los Alamos National Laboratory in the early 1980`s by Martz, Beckman and McInteer (1982). FRAC is a FORTRAN program developed to analyze Poisson distributed failure count data as a log-linear model, possibly with random as well as fixed effects. These statistical modeling assumptions are a special case of generalized linear mixed models, identified as GLMM in the current statistics literature. In the nearly 15 years since FRAC was developed, there have been considerable advances in computing capability, statistical methodology and available statistical software tools allowing worthwhile consideration of the tasks of modernizing FRAC. In this paper, the approaches to GLMM estimation implemented in GLIMMIX and in FRAC are described and a comparison of results for the two approaches is made with data on catastrophic time-dependent pump failures from a report by Martz and Whiteman (1984). Additionally, statistical and graphical model diagnostics are suggested and illustrated with the GLIMMIX analysis results
Nutritional factors and cardiovascular disease risk in Black African and Black Caribbean women: a cross-sectional study
People of Black African (BA) and Caribbean (BC) heritage form the third largest ethnic group in England and Wales. Evidence shows they experience higher rates of overweight/obesity, stroke and type 2 diabetes compared to the general population but lower risk of heart disease, which may be explained by the favourable lipid profile they exhibit (2,3). There are limited UK studies on their dietary habits and health. The aim of the current study was to assess nutritional intake and cardiovascular disease (CVD) risk factors in UK BA and BC women.
A convenience sample of self-ascribed BA and BC women, aged 19-64 years, were recruited (n = 44) from the ATTITUdinal DEterminants of diet and lifestyle (ATTITUDE) study. Cholesterol was measured using a portable CardioChek Blood Analyser, blood pressure using a digital blood pressure monitor and dietary intake via triple pass 24hr recall. Ethical approval was obtained from London Metropolitan University, King’s College London and Westminster University. Percentage energy, total fat, saturated fat, carbohydrate, and fibre and salt intake were calculated and under-reporting was assessed using the Goldberg equation. A sensitivity analysis conducted on nutrient intakes with under-reporters removed.
Nutritional intake and CVD risk factors are shown in Table 1. Sixty three percent of participants were overweight or obese. Analysis of the dietary data revealed higher intakes salt, free sugars, fat and saturated fat than recommendations and lower intake of carbohydrate. Sensitivity analysis was conducted to investigate the impact of under-reporting (n = 22). Reported data remained unchanged except for fibre intake, which was lower in the under-reporters (14.9g compared to 21.0g) (P = 0.004). Blood lipid profiles and blood pressure data were within recommendations. In conclusion, the anthropometric and certain dietary measures would indicate increased risk for developing CVD in BA and BC women, however, blood lipid profile and blood pressure measures were within healthy ranges
Creating Bell states and decoherence effects in quantum dots system
We show how to improve the efficiency for preparing Bell states in coupled
two quantum dots system. A measurement to the state of driven quantum laser
field leads to wave function collapse. This results in highly efficiency
preparation of Bell states. The effect of decoherence on the efficiency of
generating Bell states is also discussed in this paper. The results show that
the decoherence does not affect the relative weight of and in the
output state, but the efficiency of finding Bell states.Comment: 4 pages, 2figures, corrected some typo
Entangling Two Bose-Einstein Condensates by Stimulated Bragg Scattering
We propose an experiment for entangling two spatially separated Bose-Einstein
condensates by Bragg scattering of light. When Bragg scattering in two
condensates is stimulated by a common probe, the resulting quasiparticles in
the two condensates get entangled due to quantum communication between the
condensates via probe beam. The entanglement is shown to be significant and
occurs in both number and quadrature phase variables. We present two methods of
detecting the generated entanglement.Comment: 4 pages, Revte
Determination of 2,4,6-trichloroanisole by cyclic voltammetry
The electrochemical reduction of 2,4,6-trichloroanisole (TCA), a chlorinated arene with electron-donating substituents, was evaluated by cyclic voltammetry (CV). TCA is a major concern for the winery industry since it is related with “cork taint”, a wine defect. The results obtained showed that CV could be used to detect and quantify TCA in standard solutions. Linear relationships could be set between the current amplitude and TCA concentrations (R>0.990) with detection and quantification limits of 0.08 and 0.26 ppm. Although, these preliminary limits are higher than the human sensory threshold (5 ppt in wine), the simplicity of the methodology confers this study a possible role in the development of more efficient and less expensive process for TCA detection in the industry.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia
Approximate particle number projection with density dependent forces: Superdeformed bands in the A=150 and A=190 regions
We derive the equations for approximate particle number projection based on
mean field wave functions with finite range density dependent forces. As an
application ground bands of even-A superdeformed nuclei in the A=150 and A=190
regions are calculated with the Gogny force.
We discuss nuclear properties such as quadrupole moments, moments of inertia
and quasiparticle spectra, among others, as a function of the angular momentum.
We obtain a good overall description.Comment: 31 pages, 10 figures, 3 appendices. In press in Nucl. Phy
The role of RHAMM in cancer: Exposing novel therapeutic vulnerabilities
PUBLISHED 10 August 2022Receptor for hyaluronic acid-mediated motility (RHAMM) is a cell surface receptor for hyaluronic acid that is critical for cell migration and a cell cycle protein involved in microtubule assembly and stability. These functions of RHAMM are required for cellular stress responses and cell cycle progression but are also exploited by tumor cells for malignant progression and metastasis. RHAMM is often overexpressed in tumors and is an independent adverse prognostic factor for a number of cancers such as breast and prostate. Interestingly, pharmacological or genetic inhibition of RHAMM in vitro and in vivo ablates tumor invasiveness and metastatic spread, implicating RHAMM as a potential therapeutic target to restrict tumor growth and improve patient survival. However, RHAMM's pro-tumor activity is dependent on its subcellular distribution, which complicates the design of RHAMM-directed therapies. An alternative approach is to identify downstream signaling pathways that mediate RHAMM-promoted tumor aggressiveness. Herein, we discuss the pro-tumoral roles of RHAMM and elucidate the corresponding regulators and signaling pathways mediating RHAMM downstream events, with a specific focus on strategies to target the RHAMM signaling network in cancer cells.Josephine A. Hinneh, Joanna L. Gillis, Nicole L. Moore, Lisa M. Butler and Margaret M. Centener
Generation of atom-photon entangled states in atomic Bose-Einstein condensate via electromagnetically induced transparency
In this paper, we present a method to generate continuous-variable-type
entangled states between photons and atoms in atomic Bose-Einstein condensate
(BEC). The proposed method involves an atomic BEC with three internal states, a
weak quantized probe laser and a strong classical coupling laser, which form a
three-level Lambda-shaped BEC system. We consider a situation where the BEC is
in electromagnetically induced transparency (EIT) with the coupling laser being
much stronger than the probe laser. In this case, the upper and intermediate
levels are unpopulated, so that their adiabatic elimination enables an
effective two-mode model involving only the atomic field at the lowest internal
level and the quantized probe laser field. Atom-photon quantum entanglement is
created through laser-atom and inter-atomic interactions, and two-photon
detuning. We show how to generate atom-photon entangled coherent states and
entangled states between photon (atom) coherent states and atom-(photon-)
macroscopic quantum superposition (MQS) states, and between photon-MQS and
atom-MQS states.Comment: 9 pages, 1 figur
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