475 research outputs found
Humanities World Report 2015
Social Policy, Culture and Media Policy, Literature, Cultural Theor
Superconducting proximity effect and long-ranged triplets in dirty metallic antiferromagnets
Antiferromagnets have no net spin-splitting on the scale of the
superconducting coherence length. Despite this, antiferromagnets have been
observed to suppress superconductivity in a similar way as ferromagnets, a
phenomenon that still lacks a clear understanding. We find that this effect can
be explained by the role of impurities in antiferromagnets. Using
quasiclassical Green's functions, we study the proximity effect and critical
temperature in diffusive superconductor-metallic antiferromagnet bilayers. The
non-magnetic impurities acquire an effective magnetic component in the
antiferromagnet. This not only reduces the critical temperature but also
separates the superconducting correlations into short-ranged and long-ranged
components, similar to ferromagnetic proximity systems.Comment: 5 pages, 4 figure
Ossification of ungular cartilages in front feet of cold-blooded trotters - a clinical radiographic evaluation of development over time
BACKGROUND: It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-blooded trotters’ front hooves. A hundred and forty-seven of the horses were re-examined 3-13 years (mean age 9, median 8 years) after the first occasion. All radiographs were evaluated blind, using two different grading systems for OUC. Work load, in form of number of races completed, and body size score were collected from official data. Four statistical ordinal regression models were used, compared and evaluated. RESULTS: We identified a breakpoint at 2.8 ± 0.38 years of age when ossification ends and proposed a simpler grading system with more consistent results. There was no significant correlation between body size and grade of OUC. Comparison of different statistical methods for evaluation of ordinal data revealed a piecewise linear regression model as most suitable. CONCLUSIONS: Individuals with OUC developed this condition during the stage of life when their hooves develop in size. Results from this study can assist equine practitioners when examining and for understanding this condition in their clinical work and is also beneficial for the Scandinavian equine industry when devising breeding programs
The expression, processing and localization of polymorphic membrane proteins in Chlamydia pneumoniae strain CWL029
BACKGROUND: Chlamydiae are obligate intracellular bacteria, which are important human pathogens. Genome sequences of C. trachomatis and C. pneumoniae have revealed the presence of a Chlamydia specific gene family encoding polymorphic outer membrane proteins, Pmps. In C. pneumoniae the family comprises twenty-one members, which are all transcribed. In the present study, the expression, processing and localisation of the sixteen full-length Pmps in C. pneumoniae strain CWL029 have been further investigated by two-dimensional gel electrophoresis and immunofluorescence microscopy. RESULTS: Ten Pmps were identified in elementary bodies (EBs). Eight of these were investigated with respect to time dependent expression and all were found to be up-regulated between 36 and 48 hours post infection. Antibodies against Pmp6, 8, 10, 11 and 21 reacted with chlamydiae when infected cells were formalin fixed. Pmp6, Pmp20 and Pmp21 were found in cleaved forms, and the cleavage sites of Pmp6 and Pmp21 were identified. CONCLUSIONS: The Pmps are heavily up-regulated at the time of conversion of RB to EB, and at least ten Pmps are present in EBs. Due to their reaction in formalin fixation it is likely that Pmp6, 8, 10, 11 and 21 are surface exposed. The identified cleavage sites of Pmp6 and Pmp21 are in agreement with the theory that the Pmps are autotransporters
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