Familial and sporadic GJB2-related deafness in iran: Review of gene mutations

Background: Mutations in the GJB2 gene encoding connexin 26 protein, are the main cause for autosomal recessive and sporadic non syndromic hearing loss in many populations. Here, we have taken together and reviewed results from our six previous publications, our unpublished data from ten Iranian provinces, as well as data from two previous mutation reports to provide a comprehensive collection of data for GJB2 mutations and deafness in Iran. Methods: In all, 1095 hearing impaired students and their deaf siblings from 890 families in 10 provinces of Iran were studied. The prevalence and type of the GJB2 gene mutations were investigated using nested PCR Ore screening strategy and direct sequencing of the coding exon of the gene. Results: Altogether 31 different genetic variants were detected from which 17 GJB2 mutations were identified. GJB2 mutations were found in 14.6% of deaf families (18.29% of familial and 12.7% of sporadic cases). We found GJB2 mutations in both alleles in 78% of GJB2 mutations chromosomes. However, 35deIG mutation was the most common GJB2 mutation accounting for 74.5% of the mutations in populations studied. Conclusion: Our data indicated that a specific combination of GJB2 mutations types and frequencies was presented in different populations of Iran. These results also highlight the importance of GJB2 mutations in development of hearing loss in familial and sporadic deaf families in different parts of the country and can be used as a basis of genetic counseling and clinical guideline in Iran

A model-theoretic interpretation of environmentally-induced superselection

Environmentally-induced superselection or "einselection" has been proposed as an observer-independent mechanism by which apparently classical systems "emerge" from physical interactions between degrees of freedom described completely quantum-mechanically. It is shown that einselection can only generate classical systems if the "environment" is assumed \textit{a priori} to be classical; einselection therefore does not provide an observer-independent mechanism by which classicality can emerge from quantum dynamics. Einselection is then reformulated in terms of positive operator-valued measures (POVMs) acting on a global quantum state. It is shown that this re-formulation enables a natural interpretation of apparently-classical systems as virtual machines that requires no assumptions beyond those of classical computer science.Comment: 15 pages, 1 figure; minor correction

Magnetic Anisotropy of Co2MnSn1−xSbx Thin Films Grown on GaAs (001)

Heusler alloy Co2MnSn1−xSbx (x = 0.0, 0.5, and 1.0) thin films were grown on GaAs (001) substrates using pulsed laser deposition techniques. Growth parameters have been determined that result in highly magnetically anisotropic, crystalline, and oriented (001) films. The angular dependences, relative to the GaAs (001) crystallographic directions, of the coercive field Hc(θ) and the remanence Mr(θ) were determined from angle dependent magneto-optic Kerr effect (MOKE) measurements. It was found that Hc(θ) revealed higher order symmetry contributions to the magnetic anisotropy than did Mr(θ). The Fourier analysis of rotational MOKE data was used to determine the symmetry contributions to the total anisotropy

Nernst Effect and Anomalous Transport in Cuprates: A Preformed-Pair Alternative to the Vortex Scenario

We address those puzzling experiments in underdoped high $T_c$ superconductors which have been associated with normal state "vortices" and show these data can be understood as deriving from preformed pairs with onset temperature $T^* > T_c$. For uncorrelated bosons in small magnetic fields, and arbitrary $T^*/T_c$, we present the exact contribution to \textit{all} transport coefficients. In the overdoped regime our results reduce to those of standard fluctuation theories ($T^*\approx T_c$). Semi-quantitative agreement with Nernst, ac conductivity and diamagnetic measurements is quite reasonable.Comment: 9 pages, 4 figures; Title, abstract and contents modified, new references added, figures changed, one more figure added; to be published on PR