2,405 research outputs found
Designing probiotic therapies with broad-spectrum activity against a wildlife pathogen
Host-associated microbes form an important component of immunity that protect
against infection by pathogens. Treating wild individuals with these protective microbes,
known as probiotics, can reduce rates of infection and disease in both wild and captive
settings. However, the utility of probiotics for tackling wildlife disease requires that
they offer consistent protection across the broad genomic variation of the pathogen
that hosts can encounter in natural settings. Here we develop multi-isolate probiotic
consortia with the aim of effecting broad-spectrum inhibition of growth of the lethal
amphibian pathogen Batrachochytrium dendrobatidis (Bd) when tested against nine
Bd isolates from two distinct lineages. Though we achieved strong growth inhibition
between 70 and 100% for seven Bd isolates, two isolates appeared consistently
resistant to inhibition, irrespective of probiotic strategy employed. We found no evidence
that genomic relatedness of the chytrid predicted similarity of inhibition scores, nor that
increasing the genetic diversity of the bacterial consortia could offer stronger inhibition
of pathogen growth, even for the two resistant isolates. Our findings have important
consequences for the application of probiotics to mitigate wildlife diseases in the face of
extensive pathogen genomic variation
Implications and Considerations Concerning the Status, Habitat and Distribution of the Least Brook Lamprey, Lampetra aepyptera (Abbott) (Pisces: Petromyzontidae) in Arkansas
Equilibrium states and their entropy densities in gauge-invariant C*-systems
A gauge-invariant C*-system is obtained as the fixed point subalgebra of the
infinite tensor product of full matrix algebras under the tensor product
unitary action of a compact group. In the paper, thermodynamics is studied on
such systems and the chemical potential theory developed by Araki, Haag,
Kastler and Takesaki is used. As a generalization of quantum spin system, the
equivalence of the KMS condition, the Gibbs condition and the variational
principle is shown for translation-invariant states. The entropy density of
extremal equilibrium states is also investigated in relation to macroscopic
uniformity.Comment: 20 pages, revised in March 200
Off-Diagonal Long-Range Order: Meissner Effect and Flux Quantization
There has been a proof by Sewell that the hypothesis of off-diagonal
long-range order in the reduced density matrix implies the Meissner
effect. We present in this note an elementary and straightforward proof that
not only the Meissner effect but also the property of magnetic flux
quantization follows from the hypothesis. It is explicitly shown that the two
phenomena are closely related, and phase coherence is the origin for both.Comment: 11 pages, Latex fil
Off-Diagonal Long-Range Order in Bose Liquids: Irrotational Flow and Quantization of Circulation
On the basis of gauge invariance, it is proven in an elementary and
straightforward manner, but without invoking any {\it ad hoc} assumption, that
the existence of off-diagonal long-range order in one-particle reduced density
matrix in Bose liquids implies both the irrotational flow in a simply connected
region and the quantization of circulation in a multiply connected region, the
two fundamental properties of a Bose superfluid. The origin for both is the
phase coherence of condensate wave-functions. Some relevant issues are also
addressed.Comment: Revtex, 4 pages, no figure
On the Question of Temperature Transformations under Lorentz and Galilei Boosts
We provide a quantum statistical thermodynamical solution of the long
standing problem of temperature transformations of uniformly moving bodies. Our
treatment of this question is based on the well established quantum statistical
result that the thermal equilibrium conditions demanded by both the Zeroth and
Second Laws of Thermodynamics are precisely those of Kubo, Martin and Schwinger
(KMS). We prove that, in both the special relativistic and nonrelativistic
settings, a state of a body cannot satisfy these conditions for different
inertial frames with non-zero relative velocity. Hence a body that serves as a
thermal reservoir, in the sense of the Zeroth Law, in an inertial rest frame
cannot do so in a laboratory frame relative to which it moves with non-zero
uniform velocity. Consequently, there is no law of temperature transformation
under either Lorentz or Galilei boosts, and so the concept of temperature
stemming from the Zeroth Law is restricted to states of bodies in their rest
frames.Comment: A few minor corrections have been made. The article will be published
in J. Phys.
Growth, processing, and optical properties of epitaxial Er_2O_3 on silicon
Erbium-doped materials have been investigated for generating and amplifying light in low-power chip-scale optical networks on silicon, but several effects limit their performance in dense microphotonic applications. Stoichiometric ionic crystals are a potential alternative that achieve an Er^(3+) density 100× greater. We report the growth, processing, material characterization, and optical properties of single-crystal Er_2O_3 epitaxially grown on silicon. A peak Er^(3+) resonant absorption of 364 dB/cm at 1535nm with minimal background loss places a high limit on potential gain. Using high-quality microdisk resonators, we conduct thorough C/L-band radiative efficiency and lifetime measurements and observe strong upconverted luminescence near 550 and 670 nm
Numerically implemented perturbation method for the nonlinear magnetic moment of an anisotropic superconductor
We present a method to compute the magnetic moment of a bulk, finite-size,
three-dimensional, anisotropic superconductor. Our numerically implemented
perturbative procedure is based on a solution of the nonlinear Maxwell- London
equations, where we include the nonlinear relation between current and gauge
invariant velocity. The method exploits the small ratio of penetration depth to
sample size. We show how to treat the open boundary conditions over an infinite
domain and the continuity requirement at the interface. We demonstrate how our
method substantially reduces the computational work required and discuss its
implementation to an oblate spheroid. The numerical solution is obtained from a
finite difference method. We briefly discuss the relevance of this work to
similar problems in other fields.Comment: 43 pages RevTex ms and four postscript figures. To appear in Journal
of Computational Physic
Intraocular solitary extramedullary plasmacytoma presenting as unilateral anterior and intermediate uveitis preceded by refractory glaucoma
Background: Solitary extramedullary plasmacytoma (SEP) is a localised proliferation of monoclonal plasma cells involving soft tissue with no or minimal bone marrow involvement and no other systemic evidence of multiple myeloma. Intraocular involvement is exceedingly rare. Case presentation: We report a 78-year-old man who was referred with glaucoma in the right eye. He subsequently developed anterior chamber (AC) inflammation and refractory glaucoma then dense vitritis. A vitrectomy was performed with the biopsy revealing numerous plasma cells with atypical findings. In conjunction with the flow cytometry results, and a systemic work up excluding multiple myeloma, a diagnosis of SEP was made. The patient was treated with ocular external beam radiotherapy with resolution of the intraocular inflammation and control of the intraocular pressure. He remains well with no local recurrence and no development of multiple myeloma over a follow up period of 2.5 years. Conclusions: This is the first case report of SEP presenting as intraocular inflammation without a uveal tract mass
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