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This paper poses a hypothetical WTO challenge to the Passenger Name Records (PNR) Transfer Agreements the European Union has signed with the United States (as well as Australia and Canada). The focus will be on a possible citation of GATS Article XIV National Security Exception by the EU, and the viability of such a defense. Because of the absence of case law, this paper will also attempt to synthesize an acceptable standard for assessing GATS National Security Exception citations.
Little is known about the combined use of benzodiazepines and antidepressants in older psychiatric patients. This study examined the prescription pattern of concurrent benzodiazepines in older adults treated with antidepressants in Asia, and explored its demographic and clinical correlates.
The data of 955 older adults with any type of psychiatric disorders were extracted from the database of the Research on Asian Psychotropic Prescription Patterns for Antidepressants (REAP-AD) project. Demographic and clinical characteristics were recorded using a standardized protocol and data collection procedure. Both univariate and multiple logistic regression analyses were performed.
The proportion of benzodiazepine and antidepressant combination in this cohort was 44.3%. Multiple logistic regression analysis revealed that higher doses of antidepressants, younger age (<65 years), inpatients, public hospital, major comorbid medical conditions, antidepressant types, and country/territory were significantly associated with more frequent co-prescription of benzodiazepines and antidepressants.
Nearly, half of the older adults treated with antidepressants in Asia are prescribed concurrent benzodiazepines. Given the potentially adverse effects of benzodiazepines, the rationale of benzodiazepines and antidepressants co-prescription needs to be revisited.
The relationship between knowledge, risk perceptions, health belief towards seasonal influenza and vaccination and the vaccination behaviours of nurses was explored. Qualified nurses attending continuing professional education courses at a large London university between 18 April and 18 October 2010 were surveyed (522/672; response rate 77·7%). Of these, 82·6% worked in hospitals; 37·0% reported receiving seasonal influenza vaccination in the previous season and 44·9% reported never being vaccinated during the last 5 years. All respondents were categorized using two-step cluster analyses into never, occasionally, and continuously vaccinated groups. Nurses vaccinated the season before had higher scores of knowledge and risk perception compared to the unvaccinated (P<0·001). Nurses never vaccinated had the lowest scores of knowledge and risk perception compared to other groups (P<0·001). Nurses' seasonal influenza vaccination behaviours are complex. Knowledge and risk perception predict uptake of vaccination in nurses.
Characterization of defect and impurity reactions, dissociation and migration in semiconductors requires detailed understanding of rates and pathways of vibrational energy flow, of energy transfer channels and of coupling mechanisms between local modes and the phonon bath of the host material. Significant progress in reaching this goal has been accomplished in recent landmark studies exploring the excitation and dynamics of vibrational states associated with hydrogen in silicon. We describe recent experiments which measure the vibrational lifetime of the Si-H bond in various defect configurations and show the relationship between these lifetimes and silicon MOSFET reliability.
We continue our previous investigations (Yang, Zabusky,
& Chern, 1990; Zabusky & Zhang,
2002) of the interaction of a shock with a planar, inclined curtain
(slow/fast/slow) to a wider Mach number range (M =
1.5, 2.0, and 5.0) and longer times. In all cases, the generic features
may be explained in terms of the opposite-signed vortex layers
(deposited by the shock wave), which approach and collide to form a
complex vortex bilayer (VBL). At M ≤ 2.0, the VBL
traverses the shock tube and eventually collides with the opposite
horizontal boundary and evolves into upstream and downstream moving
inhomogeneous vortex projectiles (VPs) (Zabusky & Zeng, 1998). This is manifested as
early-time “breakthrough” (Yang, Zabusky,
& Chern, 1990). During the traversal, we observe and scale a
strong secondary baroclinic circulation enhancement. We track and quantify
the VPs and show that their velocities compare well to that from a simple
vortex model. We also display turbulent domains and a new rapid early time
turbulization at M = 5, when the VBL is narrower.
We examine the interaction of both cylindrical and spherical bubbles
(2D) and a complex blast wave, which consists of an
approaching shock/contact discontinuity/shock (Kang et
al., 2001a, 2001b). Such configurations may arise
following a supernova explosion, for example, SN 1987A, where a complex
blast wave is presently approaching a high density “circumstellar
ring” (CR) (Borkowski et al., 1997).
Using simulations with the piecewise parabolic method algorithm (Colella & Woodward, 1984), we emphasize the
appearance of vortex bilayers, vortex projectiles, and turbulent domains
on the downstream and upstream sides of the bubble. We believe that the
interfacial deformation of the CR is associated with a strong blast-wave
driven accelerated inhomogeneous flow instability in a high
density medium and thus will have a different character than the more
common planar shock-driven Richtmyer–Meshkov instability.
We suggest an easily obtained laboratory configuration to observe jet
and vortex flows for the Richtmyer–Meshkov (accelerated
inhomogeneous flow) environment. A hemispherical bubble in air
with density ratio of 5 is placed against an ideally reflecting wall
and struck by a planar shock. This also models a spherical bubble
struck symmetrically by two identical approaching shocks, that is, a
“reshock” configuration. For all Mach numbers
(M = 1.2, 1.5, and 2.0), our axisymmetric simulations show
that the heavy hemispherical bubble expands axially away from the wall
as a jet, and a weaker vortex ring moves radially along the wall. In
addition, when M = 1.5, a ringlike vortex projectile (VP) of
small diameter follows closely behind the reflected shock and is
associated with its moving triple point. This VP contains an entrained
shocklet and quadrupole structure of dilatation. Various methods are
applied to quantify the emerging coherent structures.
We present a numerical study to late times of a
Richtmyer–Meshkov environment: a weak shock (M = 1.095)
interacting with a heavy cylindrical bubble. The bubble interface is
modeled as a diffuse interfacial transition layer (ITL) with finite
thickness. Our simulation with the piecewise parabolic method (PPM)
yields very good agreement in large- and intermediate-scale features
with Jacobs' experiment (Jacobs, 1993).
We note the primary circulation enhancement deposited baroclinically
upon the incident shock wave, and significant secondary baroclinic
circulation enhancement, first observed in Zabusky and Zhang (2002). We propose that this vortex-accelerated
circulation deposition is universal. These baroclinic processes are
mediated by a strong gradient intensification and stretching of the ITL
and result in close-lying vortex bilayers (VBLs) and the emergence of
vortex projectiles (VPs). These account for the elongated,
kidney-shaped morphology of the rolled up bubble domain at late
Two interesting and important aspects of spontaneous CuPt ordering in III-V semiconductor alloys, which have only been investigated recently, are reviewed in this paper. The first aspect addresses the statistical effects that should be considered as the most unique consequence of the phenomenon of ordering, more specifically, how ordering affects the alloy fluctuations and hence the physical properties of the alloy. The second aspect tackles some intriguing properties of the domain twins of two CuPt ordered variants, specifically, considering the transmission of a ballistic electron beam through such a domain twin and its analogy to a highly interesting phenomenon, negative refraction, for light.
Experimental and theoretical studies are reported for a quadruple period ordering found in GaAsSb alloy layers grown by molecular beam epitaxy at high growth temperatures. We propose a growth model that accounts for the observed three-dimensional (3D) ordered structure. It is shown that the already-ordered material in the previously grown layer affects the reconstruction of the growth front with respect to the underlying alloy template resulting in the correct stacking of the individual 2D ordered layers into the observed 3D ordered structure.
Cu(II) doped ZnSe nanoparticles were synthesized using molecular cluster precursors. The Cu(II) dopant had the effect of quenching the ZnSe band edge emission, yet only weak emission from Cu(II) centers was observed. An X-ray Absorption Fine Structure (XAFS) experiment was performed on the Cu(II) doped ZnSe nanoparticles. It was determined that the Cu(II) occupies a tetrahedral site in the lattice in an environment similar to that of Cu in bulk Cu2Se, and is likely to have substituted for Zn(II) in the lattice.
The induced magnetic moment of a biased semiconductor tunnel-coupled parallel double quantum wire system is examined here. The wires are in a series arrangement with tunnel coupling to each other and to leads. Their parallel lengths and associated continuous spectrum are taken in the direction perpendicular to the lead-to-lead current. The equations of motion for the double-wire electron Green's function are formulated and analyzed using the transfer-tunneling Hamiltonian formalism. We determine the average magnetic moment of the double-wire system induced by a magnetic field applied perpendicular to the plane of the structure and we show that there are crossovers between diamagnetic and paramagnetic behavior, depending on the bias voltage, equilibrium chemical potential of the leads and temperature.
Dietary supplementation with 6000 mg of Zn2+/kg of feed has been shown to modify the clinicopathologic expression of Brachyspira hyodysenteriaeinfection in a laboratory mouse model of swine dysentery. However, this concentration impaired the body weight gain of the mice. The purpose of the present study was to determine a minimal prophylactic concentration of feed-grade zinc compounds that would not affect the growth of mice challenge-exposed with B. hyodysenteriae. A total of 440, 6- to 8-week-old, C3H/HeN mice were allocated randomly to groups and fed either a defined diet or a defined diet containing either 1000, 2000 or 4000 mg/kg ZnO, ZnSO4 or zinc-methionine for 7 days before intra- gastric inoculation with B. hyodysenteriae. From days 7 to 35 after inoculation, mice in each group were necropsied at weekly intervals for determination of body weight, presence of B. hyodysenteriae in the cecum, and histological assessment of cecal lesions. Only ZnO fed at 2000 mg/kg had a prophylactic effect against B. hyodysenteriaeinfection without affecting the body weight gain of the mice. The prophylactic effect of Zn2+ against infection with B. hyodysenteriae was also affected by the relative concentration of Fe2+ and Zn2+/Fe2+ratio of the diet.
Quantum confinement effects in opto-electronic materials have typically been limited to onedimensional confinement due to the constraints of epitaxial growth techniques. One method of forming higher degrees of confinement is the spontaneous lateral modulation seen in InAlAs shortperiod superlattices (SPS) grown on InP(00l). Here, a small number of monolayers (0.5 ˜ 2) of InAs and AlAs is alternately deposited by MBE to build a layer that exhibits lateral modulation on the 10 ˜ 25 nm scale. These materials show strong polarization and a large red shift (˜500meV) of the photo-emission spectra.
A key to understanding and predicting the properties of these films is determining their composition distribution. Using an HB-501 STEM, we have investigated the detailed composition distribution within a strongly modulated sample. The sample was grown in slight tension with respect to the InP substrate, a condition in which lateral modulation is known to be strong. Figure 1 shows a highangle annular dark-field (HAADF) image together with an intensity line scan from the image.
In the last ten years, the scanning transmission electron microscope (STEM) has become capable of forming electron probes of atomic dimensions making possible a new approach to high-resolution electron microscopy, Z-contrast imaging. Formed by mapping the intensity of high-angle scattered electrons as the probe is scanned across the specimen, the Z-contrast image represents a direct map of the specimen scattering power at atomic resolution. It is an incoherent image, and can be directly interpreted in terms of atomic columns. High angle scattering comes predominantly from the atomic nuclei, so the scattering cross section depends on atomic number (Z) squared. Z-contrast microscopy can therefore be used to study compositional ordering and segregation at the atomic scale. Here we present three examples of ordering: first, ferroelectric materials, second, III-V semiconductor alloys, and finally, cooperative segregation at a semiconductor grain boundary, where a combination of Z-contrast imaging with first principles theory provides a complete atomic-scale view of the sites and configurations of the segregant atoms.
We use resonance Raman scattering (RRS) and electroreflection (ER) measurements to profile the the composition and strain variations in laterally composition-modulated (CM) GaP/InP short-period superlattices (SPS's). The ER spectra of a GaP2.2/InP2.0 SPS give the fundamental band-gap energy at 1.69±0.05eV, which is about 210 meV lower than the band gap energy of a GaInP random alloy with the same overall composition. The RRS measurements reveal strong dependences of the phonon spectrum on the polarization and the excitation energy. In RRS spectra measured with the polarization of both excitation and scattered photons along the composition modulation direction, the GaP-like longitudinal optical (LO) phonon redshifts by 4.0±0.5 cm−1 near the resonance with the fundamental energy gap. On the other hand, when the polarizations are orthogonal to the composition modulation, the LO phonons redshift as much as 16 cm−1 at low excitation energies. A comparison of the experimental data with a model calculation gives the average In composition in the In-rich region as 0.70±0.02, and the average Ga composition in the Ga-rich region as 0.68±0.02. Our result also indicates that there are small volumes (less than 1% volume fraction) with very high In mole fraction.