877 research outputs found
Neutron diffraction study of lunar materials Final report
Apollo 12 lunar samples studied with neutron diffraction at room and cryogenic temperature
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Uncovering changes in proteomic signature of rat pelvic floor muscles in pregnancy.
BackgroundStructural and functional changes of the rat pelvic floor muscles during pregnancy, specifically, sarcomerogenesis, increase in extracellular matrix content, and higher passive tension at larger strains protect the integral muscle components against birth injury. The mechanisms underlying these antepartum alterations are unknown. Quantitative proteomics is an unbiased method of identifying protein expression changes in differentially conditioned samples. Therefore, proteomics analysis provides an opportunity to identify molecular mechanisms underlying antepartum muscle plasticity.ObjectiveTo elucidate putative mechanisms accountable for pregnancy-induced adaptations of the pelvic floor muscles, and to identify other novel antepartum alterations of the pelvic floor muscles.Materials and methodsPelvic floor muscles, comprised of coccygeus, iliocaudalis, and pubocaudalis, and nonpelvic limb muscle, tibialis anterior, were harvested from 3-month-old nonpregnant and late-pregnant Sprague-Dawley rats. After tissue homogenization, trypsin-digested peptides were analyzed by ultra-high-performance liquid chromatography coupled with tandem mass spectroscopy using nano-spray ionization. Peptide identification and label free relative quantification analysis were carried out using Peaks Studio 8.5 software (Bioinformatics Solutions Inc., Waterloo, ON, Canada). Proteomics data were visualized using the Qlucore Omics Explorer (New York, NY). Differentially expressed peptides were identified using the multi-group differential expression function, with q-value cutoff set at <0.05. Proteomic signatures of the pelvic floor muscles were compared to nonpelvic limb muscle and between nonpregnant and pregnant states.ResultsUnsupervised clustering of the data showed clear separation between samples from nonpregnant and pregnant animals along principal component 1 and between pelvic and nonpelvic muscles along principal component 2. Four major gene clusters were identified segregating proteomic signatures of muscles examined in nonpregnant vs pregnant states: (1) proteins increased in the pelvic floor muscles only; (2) proteins increased in the pelvic floor muscles and tibialis anterior; (3) proteins decreased in the pelvic floor muscles and tibialis anterior; and (4) proteins decreased in the pelvic floor muscles alone. Cluster 1 included proteins involved in cell cycle progression and differentiation. Cluster 2 contained proteins that participate in mitochondrial metabolism. Cluster 3 included proteins involved in transcription, signal transduction, and phosphorylation. Cluster 4 comprised proteins involved in calcium-mediated regulation of muscle contraction via the troponin tropomyosin complex.ConclusionPelvic floor muscles gain a distinct proteomic signature in pregnancy, which provides a mechanistic foundation for the antepartum physiological alterations acquired by these muscles. Variability in genes encoding these proteins may alter plasticity of the pelvic floor muscles and therefore the extent of the protective pregnancy-induced adaptations. Furthermore, pelvic floor muscles' proteome is divergent from that of the nonpelvic skeletal muscles
Applications of Commutator-Type Operators to -Groups
For a p-group G admitting an automorphism of order with exactly
fixed points such that has exactly fixed points,
we prove that G has a fully-invariant subgroup of m-bounded nilpotency class
with -bounded index in G. We also establish its analogue for Lie
p-rings. The proofs make use of the theory of commutator-type operators.Comment: 11 page
LDA+DMFT computation of the electronic spectrum of NiO
The electronic spectrum, energy gap and local magnetic moment of paramagnetic
NiO are computed by using the local density approximation plus dynamical
mean-field theory (LDA+DMFT). To this end the noninteracting Hamiltonian
obtained within the local density approximation (LDA) is expressed in Wannier
functions basis, with only the five anti-bonding bands with mainly Ni 3d
character taken into account. Complementing it by local Coulomb interactions
one arrives at a material-specific many-body Hamiltonian which is solved by
DMFT together with quantum Monte-Carlo (QMC) simulations. The large insulating
gap in NiO is found to be a result of the strong electronic correlations in the
paramagnetic state. In the vicinity of the gap region, the shape of the
electronic spectrum calculated in this way is in good agreement with the
experimental x-ray-photoemission and bremsstrahlung-isochromat-spectroscopy
results of Sawatzky and Allen. The value of the local magnetic moment computed
in the paramagnetic phase (PM) agrees well with that measured in the
antiferromagnetic (AFM) phase. Our results for the electronic spectrum and the
local magnetic moment in the PM phase are in accordance with the experimental
finding that AFM long-range order has no significant influence on the
electronic structure of NiO.Comment: 15 pages, 6 figures, 1 table; published versio
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On Automorphisms and Focal Subgroups of Blocks
Given a p-block B of a finite group with defect group P and fusion system on P, we show that the rank of the group is invariant under stable equivalences of Morita type. The main ingredients are the construction, due to Broué and Puig, a theorem of Weiss on linear source modules, arguments of Hertweck and Kimmerle applying Weiss’ theorem to blocks, and connections with integrable derivations in the Hochschild cohomology of block algebras
Galois theory and Lubin-Tate cochains on classifying spaces
We consider brave new cochain extensions F(BG +,R) → F(EG +,R), where R is either a Lubin-Tate spectrum E n or the related 2-periodic Morava K-theory K n , and G is a finite group. When R is an Eilenberg-Mac Lane spectrum, in some good cases such an extension is a G-Galois extension in the sense of John Rognes, but not always faithful. We prove that for E n and K n these extensions are always faithful in the K n local category. However, for a cyclic p-group C p r, the cochain extension F(BC p r +,E n ) → F(EC p r +, E n ) is not a Galois extension because it ramifies. As a consequence, it follows that the E n -theory Eilenberg-Moore spectral sequence for G and BG does not always converge to its expected target
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