2,627 research outputs found
The two components of the SO(3)-character space of the fundamental group of a closed surface of genus 2
We use geometric techniques to explicitly find the topological structure of
the space of SO(3)-representations of the fundamental group of a closed surface
of genus 2 quotient by the conjugation action by SO(3). There are two
components of the space. We will describe the topology of both components and
describe the corresponding SU(2)-character spaces by parametrizing them by
spherical triangles. There is the sixteen to one branch-covering for each
component, and the branch locus is a union of 2-spheres or 2-tori. Along the
way, we also describe the topology of both spaces. We will later relate this
result to future work into higher-genus cases and the SL(3,R)-representations
Grasses as Biofactories: Scoping out the Opportunities
Key points
1. Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins.
2. The choice of plant species depends on a multitude of factors and is determined on a caseby- case basis.
3. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa.
4. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming
Growth and Characterization of Ce- Substituted Nd2Fe14B Single Crystals
Single crystals of (Nd1-xCex)2Fe14B are grown out of Fe-(Nd,Ce) flux.
Chemical and structural analysis of the crystals indicates that
(Nd1-xCex)2Fe14B forms a solid solution until at least x = 0.38 with a
Vegard-like variation of the lattice constants with x. Refinements of single
crystal neutron diffraction data indicate that Ce has a slight site preference
(7:3) for the 4g rare earth site over the 4f site. Magnetization measurements
show that for x = 0.38 the saturation magnetization at 400 K, a temperature
important to applications, falls from 29.8 for the parent Nd2Fe14B to 27.6
(mu)B/f.u., the anisotropy field decreases from 5.5 T to 4.7 T, and the Curie
temperature decreases from 586 to 543 K. First principles calculations carried
out within density functional theory are used to explain the decrease in
magnetic properties due to Ce substitution. Though the presence of the
lower-cost and more abundant Ce slightly affects these important magnetic
characteristics, this decrease is not large enough to affect a multitude of
applications. Ce-substituted Nd2Fe14B is therefore a potential high-performance
permanent magnet material with substantially reduced Nd content.Comment: 11 Pages, 8 figures, 5 table
Grasses as Biofactories: Scoping out the Opportunities
Plant biopharming is set to dominate commercial recombinant protein expression for specific proteins. The choice of plant species depends on a multitude of factors and is determined on a case- by-case basis. As a leaf based expression system grasses would have to compete predominantly with tobacco and alfalfa. The grass-endophyte symbiosis offers a number of unique possibilities for biopharming
An evidence based clinical aid for cardiovascular disease
Copyright to Australian Family Physician. Reproduced with permission. Permission to reproduce must be sought from the publisher, The Royal Australian College of General Practitioners.Cardiovascular disease is the commonest cause of mortality in Australia, accounting for more than 30% of deaths. Hypertension, diabetes and lipid disorders account for 15.6% of the total problems encountered in general practice. Therefore all doctors should be familiar with well known risk factors for cardiovascular disease, as well as the benefits of interventions with them.Brian R McAvoy; Greg R Fulcher; John V Amerena; Greg W Conner; John F Beltrame; Graeme J Hankey; Anthony C Keech; Brian L Lloyd; Michael L Neale; Carol A Pollock; Krishna Sudhir; Robert D Waltham; Malcolm J Wes
Recommended from our members
Gut microbiota utilize immunoglobulin A for mucosal colonization
The immune system responds vigorously to microbial infection while permitting lifelong colonization by the microbiome. Mechanisms that facilitate the establishment and stability of the gut microbiota remain poorly described. We found that a regulatory system in the prominent human commensal Bacteroides fragilis modulates its surface architecture to invite binding of immunoglobulin A (IgA) in mice. Specific immune recognition facilitated bacterial adherence to cultured intestinal epithelial cells and intimate association with the gut mucosal surface in vivo. The IgA response was required for B. fragilis (and other commensal species) to occupy a defined mucosal niche that mediates stable colonization of the gut through exclusion of exogenous competitors. Therefore, in addition to its role in pathogen clearance, we propose that IgA responses can be co-opted by the microbiome to engender robust host-microbial symbiosis
Disorder-dependent superconducting phase-diagram at high magnetic fields in FeSeTe ()
We compare the superconducting phase-diagram under high magnetic fields (up
to T) of FeSeTe single crystals originally
grown by the Bridgman-Stockbarger (BRST) technique, which were annealed to
display narrow superconducting transitions and the optimal transition
temperature K, with the diagram for samples of similar
stoichiometry grown by the traveling-solvent floating-zone technique as well as
with the phase-diagram reported for crystals grown by a self-flux method. We
find that the so-annealed samples tend to display higher ratios ,
particularly for fields applied along the inter-planar direction, where the
upper critical field exhibits a pronounced downward curvature
followed by saturation at lower temperatures . This last observation is
consistent with previous studies indicating that this system is Pauli limited.
An analysis of our data using a multiband theory suggests the
emergence of the Farrel-Fulde-Larkin-Ovchnikov state at low temperatures. A
detailed structural x-ray analysis, reveals no impurity phases but an
appreciable degree of mosaicity in as-grown BRST single-crystals which remains
unaffected by the annealing process. Energy-dispersive x-ray analysis showed
that the annealed samples have a more homogeneous stoichiometric distribution
of both Fe and Se with virtually the same content of interstitial Fe as the
non-annealed ones. Thus, we conclude that stoichiometric disorder, in contrast
to structural disorder, is detrimental to the superconducting phase diagram of
this series under high magnetic fields. Finally, a scaling analysis of the
fluctuation conductivity in the superconducting critical regime, suggests that
the superconducting fluctuations have a two-dimensional character in this
system.Comment: 13 pages, 10 figures, submitted to Physical Review
- …