3,689 research outputs found
Are Asians comfortable with discussing death in health valuation studies? A study in multi-ethnic Singapore
BACKGROUND
To characterize ease in discussing death (EID) and its influence on health valuation in a multi-ethnic Asian population and to determine the acceptability of various descriptors of death and "pits"/"all-worst" in health valuation.
METHODS
In-depth interviews (English or mother-tongue) among adult Chinese, Malay and Indian Singaporeans selected to represent both genders and a wide range of ages/educational levels. Subjects rated using 0–10 visual analogue scales (VAS): (1) EID, (2) acceptability of 8 descriptors for death, and (3) appropriateness of "pits" and "all-worst" as descriptors for the worst possible health state. Subjects also valued 3 health states using VAS followed by time trade-off (TTO). The influence of sociocultural variables on EID and these descriptors was studied using univariable analyses and multiple linear regression (MLR). The influence of EID on VAS/TTO utilities with adjustment for sociocultural variables was assessed using MLR.
RESULTS
Subjects (n = 63, 35% Chinese, 32% Malay, median age 44 years) were generally comfortable with discussing death (median EID: 8.0). Only education significantly influenced EID (p = 0.045). EID correlated weakly with VAS/TTO scores (range: VAS: -0.23 to 0.07; TTO: -0.14 to 0.11). All subjects felt "passed away", "departed" and "deceased" were most acceptable (median acceptability: 8.0) while "sudden death" and "immediate death" were least acceptable (median acceptability: 5.0). Subjects clearly preferred "all-worst" to "pits" (63% vs. 19%, p < 0.001).
CONCLUSION
Singaporeans were generally comfortable with discussing death and had clear preferences for several descriptors of death and for "all-worst". EID is unlikely to influence health preference measurement in health valuation studies
Structural and electronic properties of Al nanowires: an ab initio pseudopotential study
The stability and electronic structure of a single monatomic Al wire has been
studied using the ab initio pseudopotential method. The Al wire undergoes two
structural rearrangements under compression, i.e., zigzag configurations at
angles of and . The evolution of electronic structures of the Al
chain as a function of structural phase transition has been investigated. The
relationship between electronic structure and geometric stability is also
discussed. The 2p bands in the Al nanowire are shown to play a critical role in
its stability. The effects of density functionals (GGA and LDA) on cohesive
energy and bond length of Al nanostructures (dimmer, chains, and monolayers)
are also examined. The link between low dimensional 0D structure (dimmer) to
high dimensional 3D bulk Al is estimated. An example of optimized tip-suspended
finite atomic chain is presented to bridge the gap between hypothetical
infinite chains and experimental finite chains.Comment: 11 pages, 5 figure
Predictable arguments of knowledge
We initiate a formal investigation on the power of predictability for argument of knowledge systems for NP. Specifically, we consider private-coin argument systems where the answer of the prover can be predicted, given the private randomness of the verifier; we call such protocols Predictable Arguments of Knowledge (PAoK).
Our study encompasses a full characterization of PAoK, showing that such arguments can be made extremely laconic, with the prover sending a single bit, and assumed to have only one round (i.e., two messages) of communication without loss of generality.
We additionally explore PAoK satisfying additional properties (including zero-knowledge and the possibility of re-using the same challenge across multiple executions with the prover), present several constructions of PAoK relying on different cryptographic tools, and discuss applications to cryptography
One-dimensional collision carts computer model and its design ideas for productive experiential learning
We develop an Easy Java Simulation (EJS) model for students to experience the
physics of idealized one-dimensional collision carts. The physics model is
described and simulated by both continuous dynamics and discrete transition
during collision. In the field of designing computer simulations, we discuss
briefly three pedagogical considerations such as 1) consistent simulation world
view with pen paper representation, 2) data table, scientific graphs and
symbolic mathematical representations for ease of data collection and multiple
representational visualizations and 3) game for simple concept testing that can
further support learning. We also suggest using physical world setup to be
augmented complimentary with simulation while highlighting three advantages of
real collision carts equipment like tacit 3D experience, random errors in
measurement and conceptual significance of conservation of momentum applied to
just before and after collision. General feedback from the students has been
relatively positive, and we hope teachers will find the simulation useful in
their own classes. 2015 Resources added:
http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/46-one-dimension-collision-js-model
http://iwant2study.org/ospsg/index.php/interactive-resources/physics/02-newtonian-mechanics/02-dynamics/195-elastic-collisionComment: 6 pages, 8 figures, 1 table, 1 L. K. Wee, Physics Education 47 (3),
301 (2012); ISSN 0031-912
Enhanced self-field critical current density of nano-composite YBa(2)Cu(3)O(7) thin films grown by pulsed-laser deposition
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ EPLA, 2008.Enhanced self-field critical current density Jc of novel, high-temperature superconducting thin films is reported. Layers are deposited on (001) MgO substrates by laser ablation of YBa2Cu3O7−δ(Y-123) ceramics containing Y2Ba4CuMOx (M-2411, M=Ag, Nb, Ru, Zr) nano-particles. The Jc of films depends on the secondary-phase content of the ceramic targets, which was varied between 0 and 15 mol%. Composite layers (2 mol% of Ag-2411 and Nb-2411) exhibit Jc values at 77 K of up to 5.1 MA/cm2, which is 3 to 4 times higher than those observed in films deposited from phase pure Y-123 ceramics. Nb-2411 grows epitaxially in the composite layers and the estimated crystallite size is ~10 nm.The Austrian Science Fund, the Austrian Federal Ministry of Economics and Labour, the European Science Foundation and the Higher Education Commission of Pakistan
Cationic vacancy induced room-temperature ferromagnetism in transparent conducting anatase Ti_{1-x}Ta_xO_2 (x~0.05) thin films
We report room-temperature ferromagnetism in highly conducting transparent
anatase Ti1-xTaxO2 (x~0.05) thin films grown by pulsed laser deposition on
LaAlO3 substrates. Rutherford backscattering spectrometry (RBS), x-ray
diffraction (XRD), proton induced x-ray emission (PIXE), x-ray absorption
spectroscopy (XAS) and time-of-flight secondary ion mass spectrometry
(TOF-SIMS) indicated negligible magnetic contaminants in the films. The
presence of ferromagnetism with concomitant large carrier densities was
determined by a combination of superconducting quantum interference device
(SQUID) magnetometry, electrical transport measurements, soft x-ray magnetic
circular dichroism (SXMCD), XAS, and optical magnetic circular dichroism (OMCD)
and was supported by first-principle calculations. SXMCD and XAS measurements
revealed a 90% contribution to ferromagnetism from the Ti ions and a 10%
contribution from the O ions. RBS/channelling measurements show complete Ta
substitution in the Ti sites though carrier activation was only 50% at 5% Ta
concentration implying compensation by cationic defects. The role of Ti vacancy
and Ti3+ was studied via XAS and x-ray photoemission spectroscopy (XPS)
respectively. It was found that in films with strong ferromagnetism, the Ti
vacancy signal was strong while Ti3+ signal was absent. We propose (in the
absence of any obvious exchange mechanisms) that the localised magnetic
moments, Ti vacancy sites, are ferromagnetically ordered by itinerant carriers.
Cationic-defect-induced magnetism is an alternative route to ferromagnetism in
wide-band-gap semiconducting oxides without any magnetic elements.Comment: 21 pages, 10 figures, to appear in Philosophical Transaction - Royal
Soc.
CEACAM1 negatively regulates platelet-collagen interactions and thrombus growth in vitro and in vivo
Carcinoembryonic antigen cell adhesion molecule-1 (CEACAM1) is a surface glycoprotein expressed on various blood cells, epithelial cells, and vascular cells. CEACAM1 possesses adhesive and signaling properties mediated by its intrinsic immunorecep-tor tyrosine-based inhibitory motifs that recruit SHP-1 protein-tyrosine phosphatase. In this study, we demonstrate that CEACAM1 is expressed on the surface and in intracellular pools of platelets. In addition, CEACAM1 serves to negatively regulate signaling of platelets by collagen through the glycoprotein VI (GPVI)/Fc receptor (FcR)-?-chain. ceacam1 -/- platelets displayed enhanced type I collagen and GPVI-selective ligand, collagen-related peptide (CRP), CRP-mediated platelet aggregation, enhanced platelet adhesion on type I collagen, and elevated CRP-mediated alpha and dense granule secretion. Platelets derived from ceacam1-/- mice form larger thrombi when perfused over a collagen matrix under arterial flow compared with wild-type mice. Furthermore, using intravital microscopy to ferric chloride-injured mesenteric arterioles, we show that thrombi formed in vivo in ceacam1-/- mice were larger and were more stable than those in wild-type mice. GPVI depletion using monoclonal antibody JAQ1 treatment of ceacam1-/- mice showed a reversal in the more stable thrombus growth phenotype. ceacam1-/- mice were more susceptible to type I collagen-induced pulmonary thromboembolism than wild-type mice. Thus, CEACAM1 acts as a negative regulator of platelet-collagen interactions and of thrombus growth involving the collagen GPVI receptor in vitro and in vivo
Are symbols useful and culturally acceptable in health-state valuation studies? An exploratory study in a multi-ethnic Asian population
10.2147/PPA.S4142Patient Preference and Adherence2271-27
Survey for Transiting Extrasolar Planets in Stellar Systems. II. Spectrophotometry and Metallicities of Open Clusters
We present metallicity estimates for seven open clusters based on
spectrophotometric indices from moderate-resolution spectroscopy. Observations
of field giants of known metallicity provide a correlation between the
spectroscopic indices and the metallicity of open cluster giants. We use \chi^2
analysis to fit the relation of spectrophotometric indices to metallicity in
field giants. The resulting function allows an estimate of the target-cluster
giants' metallicities with an error in the method of \pm0.08 dex. We derive the
following metallicities for the seven open clusters: NGC 1245,
[m/H]=-0.14\pm0.04; NGC 2099, [m/H]=+0.05\pm0.05; NGC 2324, [m/H]=-0.06\pm0.04;
NGC 2539, [m/H]=-0.04\pm0.03; NGC 2682 (M67), [m/H]=-0.05\pm0.02; NGC 6705,
[m/H]=+0.14\pm0.08; NGC 6819, [m/H]=-0.07\pm0.12. These metallicity estimates
will be useful in planning future extra-solar planet transit searches since
planets may form more readily in metal-rich environments.Comment: 38 pages, including 12 figures. Accepted for publication in A
Two-State Spectral-Free Solutions of Frenkel-Moore Simplex Equation
Whilst many solutions have been found for the Quantum Yang-Baxter Equation
(QYBE), there are fewer known solutions available for its higher dimensional
generalizations: Zamolodchikov's tetrahedron equation (ZTE) and Frenkel and
Moore's simplex equation (FME). In this paper, we present families of solutions
to FME which may help us to understand more about higher dimensional
generalization of QYBE.Comment: LaTeX file. Require macros: cite.sty and subeqnarray.sty to process.
To appear in J. Phys. A: Math. and Ge
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