2,028 research outputs found
Stabilization of internal space in noncommutative multidimensional cosmology
We study the cosmological aspects of a noncommutative, multidimensional
universe where the matter source is assumed to be a scalar field which does not
commute with the internal scale factor. We show that such noncommutativity
results in the internal dimensions being stabilizedComment: 8 pages, 1 figure, to appear in IJMP
Association of the TCF7L2 rs12255372 (G/T) variant with type 2 diabetes mellitus in an Iranian population
In various populations worldwide, common variants of the TCF7L2 (Transcription factor 7-like 2) gene are associated with the risk of type 2 diabetes mellitus (T2DM). The aim was to investigate the association between rs12255372 (G/T) polymorphism in the TCF7L2 gene and T2DM in an Iranian population. 236 unrelated patients with T2DM, and 255 normoglycemic controls without diabetes were studied. The PCR-RFLP method was used for genotyping rs12255372 (G/T) polymorphism, and the SPSS version 18.0 for Windows for statistical analysis. The minor T allele of TCF7L2 rs12255372 was found to significantly increase the risk of T2DM, with an allelic odds ratio (OR) of 1.458 (95% CI 1.108-1.918, p = 0.007). A significant difference in TT genotype was observed between T2DM patients and normoglycemic controls (OR 2.038, 95% CI 1.147-3.623; p = 0.014). On assuming dominant and recessive models, ORs of 1.52 [95% CI (1.05-2.21) p = 0.026)] and 1.74 [95% CI (1.01-3.00) p = 0.043] were obtained, respectively, thereby implying that the co-dominant model would best fit the susceptible gene effect. This study further confirms the TCF7L2 gene as enhancing susceptibility to the development of T2DM. © 2012, Sociedade Brasileira de Genética
The electromagnetic field near a dielectric half-space
We compute the expectations of the squares of the electric and magnetic
fields in the vacuum region outside a half-space filled with a uniform
non-dispersive dielectric. This gives predictions for the Casimir-Polder force
on an atom in the `retarded' regime near a dielectric. We also find a positive
energy density due to the electromagnetic field. This would lead, in the case
of two parallel dielectric half-spaces, to a positive, separation-independent
contribution to the energy density, besides the negative, separation-dependent
Casimir energy. Rough estimates suggest that for a very wide range of cases,
perhaps including all realizable ones, the total energy density between the
half-spaces is positive.Comment: Latex2e, IOP macros, 15 pages, 2 eps figure
The Association of the Human Leukocyte Antigen (HLA) with the Pathogenesis of Helicobacter pylori
H. pylori pathogenesis is related to various virulence factor which some of them involved to adhesions. Urease as a main pathogenecity factor to attach to HLA-II is expressed on the surface of Gastric Epithelial Cells (GECs). Apoptosis induced by caspase3 activation as a result of urease effects on Spermine-Spermidine cycle. There is a contribution of HLA-DQA1 gene to the host's response against H. pylon. HLA allele type as an immune-genetic factors are related to host susceptibility to H. pylori. HLA-DQA1 might be contributed to the susceptibility or resistance to H. pylori infection. Based on the existed evidences the current review aimed to evaluate the results obtained by different studies carried out so far on correlation of human HLA and the pathogenesis of the H. pylori in gastric epithelial cells
Inequalities involving Hadamard product for sector matrices
Important inequalities for some operator mean inequalities involving Hadamard
product have been proved, recently. In this paper, we extend these inequalities
to inequalities for sector matrices which involve the mean of sector matrices,
the positive linear maps and operator monotone functions
Asymptotically Non-Static Kerr-deSitter Spacetime With No Event Horizon
We present our derivations for Kerr-deSitter metric in a proper comoving
coordinate system.It asymptotically approaches to the deSitter metric in
Robertson-walker form.This has been done by considring the stationary
axially-symmetric spacetime in which motion of particle is integrable.That is
the Hamilton-Jacobi and Klein-Gordon equations are separable.In this form it is
asymptotically consistent with comoving frame.Comment: Title changed,revised arguments,results unchanged
Variations in fish body and scale shape among Aphanius dispar (Cyprinodontidae) populations: insights from a geometric morphometric analysis
Phenotypic variations in fish body and scale shape were investigated among the three populations of Aphanius dispar (Rüppell, 1829) in Southern Iran through the use of landmark-based geometric morphometric analyses.This species is widely distributed in the region, and therefore, considerable morphological variations exist among the geographically allopatric populations. Based on the Principle Component Analysis (PCA), variation in body shape of the females is prominently related to the dorsal fin region, while in the males it is related to the dorsal fin and caudal peduncle. Moreover, the shape variations in the scales are obviously linked to the tip of anterior portion of the scales, and the left and right boundaries between anterior and posterior regions of the scales. The lateral sides of the fish scales in site I are concave, while they are laterally convex in sites II and III. The observed variation seen in the fish body shape and scales among the three studied sites are probably caused by the different ecological conditions of their habitats particularly variation in water flow
Horizon Problem Remediation via Deformed Phase Space
We investigate the effects of a special kind of dynamical deformation between
the momenta of the scalar field of the Brans-Dicke theory and the scale factor
of the FRW metric. This special choice of deformation includes linearly a
deformation parameter. We trace the deformation footprints in the cosmological
equations of motion when the BD coupling parameter goes to infinity. One class
of the solutions gives a constant scale factor in the late time that confirms
the previous result obtained via another approach in the literature. This
effect can be interpreted as a quantum gravity footprint in the coarse grained
explanation. The another class of the solutions removes the big bang
singularity, and the accelerating expansion region has an infinite temporal
range which overcomes the horizon problem. After this epoch, there is a
graceful exiting by which the universe enters in the radiation dominated era.Comment: 13 pages, 2 figures, to appear in GER
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