2,329 research outputs found
A novel missense mutation in the gene for gap-junction protein α3 (GJA3) associated with autosomal dominant “nuclear punctate” cataracts linked to chromosome 13q
No evidence that mask-wearing in public places elicits risk compensation behavior during the COVID-19 pandemic
No evidence that mask-wearing in public places elicits risk compensation behavior during the COVID-19 pandemic
Scaling Flows and Dissipation in the Dilute Fermi Gas at Unitarity
We describe recent attempts to extract the shear viscosity of the dilute
Fermi gas at unitarity from experiments involving scaling flows. A scaling flow
is a solution of the hydrodynamic equations that preserves the shape of the
density distribution. The scaling flows that have been explored in the
laboratory are the transverse expansion from a deformed trap ("elliptic flow"),
the expansion from a rotating trap, and collective oscillations. We discuss
advantages and disadvantages of the different experiments, and point to
improvements of the theoretical analysis that are needed in order to achieve
definitive results. A conservative bound based on the current data is that the
minimum of the shear viscosity to entropy density ration is that eta/s is less
or equal to 0.5 hbar/k_B.Comment: 32 pages, prepared for "BCS-BEC crossoverand the Unitary Fermi Gas",
Lecture Notes in Physics, W. Zwerger (editor), Fig. 5 corrected, note added;
final version, corrected typo in equ. 9
Digital Imaging and Analysis of Dusty Plasmas
Dust particles immersed within a plasma environment, such as those found in
planetary rings or cometary environments, will acquire an electric charge. If
the ratio of interparticle potential energy to average kinetic energy is high
enough the particles will form either a 'liquid' structure with short-range
ordering or a crystalline structure with long-range ordering. Since their
discovery in laboratory environments in 1994, such crystals have been the
subject of a variety of experimental, theoretical, and numerical
investigations. Laboratory experiments analyzing the behavior of dust grains in
a plasma rely on optical diagnostics to provide data about the system in a
non-perturbative manner. In the past, capturing, imaging, and analyzing
crystalline structure in dusty plasmas has been a non-trivial problem.
Utilizing digital imaging and analysis systems, data capture, image formatting,
and analysis can be done quickly. Following data capture, image analysis is
conducted using modified Particle Image Velocimetry (PIV) and Particle Tracking
Velocimetry (PTV) algorithms. The data extracted is then used to construct
Voronoi diagrams, calculate particle density, inter-particle spacing, pair
correlation functions, and thermal energy. From this data other dust plasma
parameters can be inferred such as inter-particle forces and grain charges.Comment: 6 pages, Presented at COSPAR '0
Longitudinal Predictors of Self-Reliance for Coping with Mental Health Problems in the Military
Military personnel encounter occupational hazards that make them vulnerable to developing mental health symptoms; however, many soldiers who experience a problem do not seek treatment. A major barrier to treatment is self-reliance, a preference to manage problems oneself rather than seek help from a professional. In the present study, we sought a more comprehensive understanding of factors that contribute to self-reliance. Active-duty soldiers (N = 485) were surveyed at two time points. The sample was 93% male, 67% Caucasian, and most were aged 20-24 (49%). The survey included: factors that affect treatment-seeking, deployment experiences, and mental health symptoms. Results indicated that stigmatizing beliefs about those who seek treatment and negative beliefs about treatment at Time 1 were related to higher preferences for self-reliance at Time 2, while positive beliefs about treatment at Time 1 were related to lower self-reliance. Combat exposure, mental health symptoms, social support for treatment-seeking, and stigma from others were not significant predictors. These results demonstrate that self-reliance may not be unique to combat soldiers and may not diminish as symptoms become severe. Instead one’s views of treatment and others who seek treatment may be more impactful, and should be the target of interventions to encourage treatment-seeking
Dynamics of a Dust Crystal with Two Different Size Dust Species
A self-consistent three-dimensional model for a complex (dusty) plasma is
used to study the effects of multiple-sized dust grains in a dust crystal. In
addition to the interparticle forces, which interact through a Yukawa
potential, the model includes the effects of gravity, the variation of the
sheath potential above the powered electrode, and a radial confining potential.
Simulations studied various ratios of a mix of 6.5- and 8.9-micron monodisperse
particles and compared their correlation functions, electric potential energy
of the crystal formations, and the dispersion relations for in-plane and
out-of-plane dust lattice wave (DLW) modes for two different sheath
thicknesses. In the 7 mm sheath, the particles formed two layers in the
vertical direction by size, and acted as a two-layer crystal with weak
correlation between the layers. In the 3 mm sheath, the particles formed an
essentially monolayer crystal; however the crystal dynamics showed some
characteristics of a bilayer crystal
A novel method for the quantification of tire and polymer-modified bitumen particles in environmental samples by pyrolysis gas chromatography mass spectroscopy
Expression of apoplast-targeted plant defensin \u3ci\u3eMtDef4.2\u3c/i\u3e confers resistance to leaf rust pathogen \u3ci\u3ePuccinia triticina\u3c/i\u3e but does not affect mycorrhizal symbiosis in transgenic wheat
Rust fungi of the order Pucciniales are destructive pathogens of wheat worldwide. Leaf rust caused by the obligate, biotrophic basidiomycete fungus Puccinia triticina (Pt) is an economically important disease capable of causing up to 50 % yield losses. Historically, resistant wheat cultivars have been used to control leaf rust, but genetic resistance is ephemeral and breaks down with the emergence of new virulent Pt races. There is a need to develop alternative measures for control of leaf rust in wheat. Development of transgenic wheat expressing an antifungal defensin offers a promising approach to complement the endogenous resistance genes within the wheat germplasm for durable resistance to Pt. To that end, two different wheat genotypes, Bobwhite and Xin Chun 9 were transformed with a chimeric gene encoding an apoplast-targeted antifungal plant defensin MtDEF4.2 from Medicago truncatula. Transgenic lines from four independent events were further characterized. Homozygous transgenic wheat lines expressing MtDEF4.2 displayed resistance to Pt race MCPSS relative to the non-transgenic controls in growth chamber bioassays. Histopathological analysis suggested the presence of both pre- and posthaustorial resistance to leaf rust in these transgenic lines. MtDEF4.2 did not, however, affect the root colonization of a beneficial arbuscular mycorrhizal fungus Rhizophagus irregularis. This study demonstrates that the expression of apoplast-targeted plant defensin MtDEF4.2 can provide substantial resistance to an economically important leaf rust disease in transgenic wheat without negatively impacting its symbioti
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