7,445 research outputs found
Hepatitis Associated with a Sarcocystis canisâlike Protozoan in a Hawaiian Monk Seal (Monachus schauinslandi)
A Hawaiian monk seal (Monachus schauinslandi) died in captivity at the National Marine Fisheries Service, Kewalo Basin Facility in Honolulu, Hawaii. The animal was icteric, and the liver was friable. Microscopic lesions were detected in the colon and liver. Colonic lesions included multifocal, necrohemorrhagic colitis associated with gram-negative bacilli. The liver lesions included random hepatic necrosis and cholestasis. Asexual stages of a Sarcocystis canisâlike apicomplexan were detected in hepatocytes. The parasite divided by endopolygeny. Merozoites occasionally formed rosettes around a central residual body. Ultrastructurally, merozoites lacked rhoptries. This is the first report of S. canis infection in M. schauinslandi, which is an endangered pinniped in U.S. waters
Deformed two center shell model
A highly specialized two-center shell model has been developed accounting for
the splitting of a deformed parent nucleus into two ellipsoidaly deformed
fragments. The potential is based on deformed oscillator wells in direct
correspondance with the shape change of the nuclear system. For the first time
a potential responsible for the necking part between the fragments is
introduced on potential theory basis. As a direct consequence, spin-orbit {\bf
ls} and {\bf l} operators are calculated as shape dependent. Level scheme
evolution along the fission path for pairs of ellipsoidaly deformed fragments
is calculated. The Strutinsky method yields the shell corrections for different
mass asymmetries from the superheavy nucleus 122 and Cf all
along the splitting process.Comment: 32 pages, 8 figure
Recommended from our members
The influence of shock pressure, pre-shock temperature, and host rock composition on the survival rate of endolithic microorganisms during impact ejection from Mars
Petrographic and biological analysis of shock recovery experiments confirms the possible life transport due to an impact from Mars to Earth
Carotenoid Raman signatures are better preserved in dried cells of the desert cyanobacterium Chroococcidiopsis than in hydrated counterparts after high-dose gamma irradiation
Carotenoids are promising targets in our quest to search for life on Mars due to their
biogenic origin and easy detection by Raman spectroscopy, especially with a 532 nm excitation thanks to resonance effects. Ionizing radiations reaching the surface and subsurface of Mars are however detrimental for the long-term preservation of biomolecules. We show here that desiccation can protect carotenoid Raman signatures in the desert cyanobacterium Chroococcidiopsis sp. CCMEE 029 even after high-dose gamma irradiation. Indeed, while the height of the carotenoids Raman peaks was considerably reduced in hydrated cells exposed to gamma irradiation, it remained stable in dried cells irradiated with the highest tested dose of 113 kGy of gamma rays, losing only 15-20% of its non-irradiated intensity. Interestingly, even though the carotenoid Raman signal of hydrated cells lost 90% of its non-irradiated intensity, it was still detectable after exposure to 113 kGy of gamma rays. These results add insights into the preservation potential and detectability limit of carotenoid-like molecules on Mars over a prolonged period of time and are crucial in supporting
future missions carrying Raman spectrometers to Marsâ surface
Symmetric Anderson impurity model with a narrow band
The single channel Anderson impurity model is a standard model for the
description of magnetic impurities in metallic systems. Usually, the bandwidth
represents the largest energy scale of the problem. In this paper, we analyze
the limit of a narrow band, which is relevant for the Mott-Hubbard transition
in infinite dimensions. For the symmetric model we discuss two different
effects: i) The impurity contribution to the density of states at the Fermi
surface always turns out to be negative in such systems. This leads to a new
crossover in the thermodynamic quantities that we investigate using the
numerical renormalization group. ii) Using the Lanczos method, we calculate the
impurity spectral function and demonstrate the breakdown of the skeleton
expansion on an intermediate energy scale. Luttinger's theorem, as an example
of the local Fermi liquid property of the model, is shown to still be valid.Comment: 4 pages RevTeX, 2 eps figures included, final versio
CASAM: Collaborative Human-machine Annotation of Multimedia.
The CASAM multimedia annotation system implements a model of cooperative annotation between a human annotator and automated components. The aim is that they work asynchronously but together. The system focuses upon the areas where automated recognition and reasoning are most effective and the user is able to work in the areas where their unique skills are required. The systemâs reasoning is influenced by the annotations provided by the user and, similarly, the user can see the systemâs work and modify and, implicitly, direct it. The CASAM system interacts with the user by providing a window onto the current state of annotation, and by generating requests for information which are important for the final annotation or to constrain its reasoning. The user can modify the annotation, respond to requests and also add their own annotations. The objective is that the human annotatorâs time is used more effectively and that the result is an annotation that is both of higher quality and produced more quickly. This can be especially important in circumstances where the annotator has a very restricted amount of time in which to annotate the document. In this paper we describe our prototype system. We expand upon the techniques used for automatically analysing the multimedia document, for reasoning over the annotations generated and for the generation of an effective interaction with the end-user. We also present the results of evaluations undertaken with media professionals in order to validate the approach and gain feedback to drive further research
Dual equivalence in models with higher-order derivatives
We introduce a class of higher-order derivative models in (2,1) space-time
dimensions. The models are described by a vector field, and contain a
Proca-like mass term which prevents gauge invariance. We use the gauge
embedding procedure to generate another class of higher-order derivative
models, gauge-invariant and dual to the former class. We show that the results
are valid in arbitrary (d,1) space-time dimensions when one discards the
Chern-Simons and Chern-Simons-like terms. We also investigate duality at the
quantum level, and we show that it is preserved in the quantum scenario. Other
results include investigations concerning the gauge embedding approach when the
vector field couples with fermionic matter, and when one adds nonlinearity.Comment: RevTex4, 14 pages; new version includes duality at the quantum level,
and new references. To be published in J. Phys.
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