Purely radiative irrotational dust spacetimes

We consider irrotational dust spacetimes in the full non-linear regime which are "purely radiative" in the sense that the gravitational field satisfies the covariant transverse conditions div(H) = div(E) = 0. Within this family we show that the Bianchi class A spatially homogeneous dust models are uniquely characterised by the condition that $H$ is diagonal in the shear-eigenframe.Comment: 6 pages, ERE 2006 conference, minor correction

Perfectionism Search Algorithm (PSA): An Efficient Meta-Heuristic Optimization Approach

This paper proposes a novel population-based meta-heuristic optimization algorithm, called Perfectionism Search Algorithm (PSA), which is based on the psychological aspects of perfectionism. The PSA algorithm takes inspiration from one of the most popular model of perfectionism, which was proposed by Hewitt and Flett. During each iteration of the PSA algorithm, new solutions are generated by mimicking different types and aspects of perfectionistic behavior. In order to have a complete perspective on the performance of PSA, the proposed algorithm is tested with various nonlinear optimization problems, through selection of 35 benchmark functions from the literature. The generated solutions for these problems, were also compared with 11 well-known meta-heuristics which had been applied to many complex and practical engineering optimization problems. The obtained results confirm the high performance of the proposed algorithm in comparison to the other well-known algorithms

Couplinator: A simple computational tool for synthesis of multi-section coupled-line filter based on MPCM-TLM technique

A new simple computational tool is proposed for the synthesis of multi-section coupled-line filters based on combined modified planar circuit method (MPCM) and transmission line method (TLM) analysis, referred to as MPCM-TLM. Due to its fundamentally simple architecture, the presented tool offers significantly faster optimization of coupled-line filters – for exactly the same initial simulation set-up – than other costly commercially-available tools, giving equally reliable results. Validity and accuracy of the proposed tool have been verified through the design of 3rd, 5th, and 7th order coupled-line filters and comparative analysis between results obtained from the proposed approach and the high-frequency structure simulator. A remarkable 99% time reduction in the analysis is recorded in the case of 7th order filter using the proposed tool, for almost identical results to HFSS. Therefore, it can be confidently claimed that the proposed technique can be used as a reliable alternative to existing complex, costly, processor-intensive CAD tools

Purely radiative perfect fluids with degenerate shear tensor

We consider non-rotating geodesic perfect fluid spacetimes which are purely radiative in the sense that the gravitational field satisfies the covariant transverse conditions div H = div E = 0. We show that when the shear tensor S is degenerate, H, E and S necessarily commute and hence the resulting spacetimes are hypersurface homogeneous of Bianchi class A (modulo some purely electric exceptions).Comment: 8 pages, references added, typos corrected, simplified some algebraic manipulation

Arg399Gln substitution in XRCC1 as a prognostic and predictive biomarker for prostate cancer: Evidence from 8662 subjects and a structural analysis

Abstract Background The Arg399Gln polymorphism in the X ray repair cross complementing group 1 gene ( XRCC1 ) may alter the risk of prostate cancer (PCa). The present study aimed to investigate the association of the XRCC1 Arg399Gln poly- morphism with PCa risk in an Iranian population, as followed by a meta analysis and an in silico analysis. Methods In a case control study, 360 subjects were included (180 men with PCa and 180 healthy controls). XRCC1 Arg399Gln genotyping was performed using the polymerase chain reaction restriction fragment length polymorphism method. In the meta analysis, 14 eligible studies were included to which our case control data were added to estimate the pooled odds ratios. Some bioinformatics tools were employed to evaluate the effects of Arg399Gln substitution on molecular aspects of the XRCC1 protein. Results Our case control study revealed a significant association between the XRCC1 Arg399Gln polymorphism and PCa risk. The data from overall meta analysis showed significant associations between the mentioned polymorphism and PCa risk in allelic and recessive genetic models. In addition, we observed statistically significant associations in stratified analyses by ethnicity, sample size and source of controls. Our in silico analysis showed that Arg399Gln substitution could be damaging with respect to the function and structure of the XRCC1 protein. Conclusions Based on these results, the XRCC1 Arg399Gln polymorphism might be a risk factor for PCa and it could be considered as a prognostic and predictive biomarker for susceptible men. KEYWORDS in silico analysis, meta analysis, prostate cancer, XRCC1 gen

Synthesis and biological activity of some heterocyclic compounds contains N-benzylidene heterocycle and beta-lactam moiety

A number of N-benzylidene heterocycle derivatives have been synthesized and their antibacterial activities tested. The new chemical structures synthesized compounds were verified on the basis of spectral and elemental methods of analyses.the antimicrobial activity of the compounds was done by disc diffusion method We synthesized two different types of compounds, a combination of compounds based on the structure of isatin and other compounds based on the structure of thiazole. Synthesis of thiazole was performed using green chemistry method and a three-step reaction was used in the synthesis of isatin compounds. We used the Stoell-Becker method to synthesize compounds based on the isatin structure. The synthesized product was characterized by its physical properties, melting point, TLC and then subjected to the in vitro antibacterial activities against gram-positive and gram-negative strains of microbe

Detection and evaluation of damage in aircraft composites using electromagnetically coupled inductors

The paper presents a quantitative damage evaluation of carbon-fibre reinforced polymer (CFRP) plates using a non-contact electromagnetic (EM) sensor. The EM sensor with coupled spiral inductors (CSI) is employed here to detect both impact induced and simulated damage leading to an accurate evaluation of the location, depth and width of sub-surface defects. The effect of inspection frequency, standoff distance and signal power are also investigated leading to the development of an engineering circuit design tool that relates the set up and calibration of the sensor to its detection performance. It is found that the dynamic range of the transmission coefficient is the limiting factor in the original Salski CSI sensor and this problem is addressed by adding ferrite layers to reduce the reluctance of the magnetic circuit, improving damage sensing by 22%. The study leads to a further development of utilising an open ferrite yoke with a pair of encircling coils, which shows a 57% sensitivity improvement and clearer identification of air gaps (voids) and delamination in CFRP laminates. The proposed EM yoke design CSI sensor is low cost and could be assembled into an array for non-contact, in situ mechatronic scanning of aircraft composite wings

Shearfree perfect fluids with solenoidal magnetic curvature and a gamma-law equation of state

We show that shearfree perfect fluids obeying an equation of state p=(gamma -1) mu are non-rotating or non-expanding under the assumption that the spatial divergence of the magnetic part of the Weyl tensor is zero.Comment: 11 page

Purely radiative perfect fluids

We study `purely radiative' (div E = div H = 0) and geodesic perfect fluids with non-constant pressure and show that the Bianchi class A perfect fluids can be uniquely characterized --modulo the class of purely electric and (pseudo-)spherically symmetric universes-- as those models for which the magnetic and electric part of the Weyl tensor and the shear are simultaneously diagonalizable. For the case of constant pressure the same conclusion holds provided one also assumes that the fluid is irrotational.Comment: 12 pages, minor grammatical change

Relationship Between Quality of Life and Depression in Pregnant Women

Background: Quality of life differs for different people in different situations and is related to one's self-satisfaction with life. Quality of life is affected by health status. Objectives: The current study examined the relationship between quality of life and depression in pregnant women in Kashan city. Patients and Methods: A Case - control study was performed on 112 depressed pregnant women (Case Group) and 353 Non-depressed pregnant women (Control Group) who referred to the prenatal health care centers of Kashan University of Medical Sciences .They completed Short Form 36 Health Survey (SF-36) to assess the quality of life and the Beck Depression Inventory to assess the level of depressive symptoms. T-test, chi-square and Pearson correlation coefficient statistical tests were used for data analysis. Results: The findings showed that there was an inverse relationship between quality of life and depression in pregnancy (P = 0.0001). Average scores in all eight domains of quality of life were significantly lower in depressed pregnant women compared to non- depressed women. The strongest relationship was observed between depression and vitality (r =-0.52, P = 0.0001), mental health (r = -0.50, P = 0.001) and social functioning (r =-0.38, P = 0.001). Conclusion: Depressed pregnant women had a lower quality of life. The proper management of depression during pregnancy can improve the quality of life in women. It is recommended that antenatal services integrate screening for depression into routine antenatal care