Effect of surface layer thickness on the performance of lime and cement treated aggregate surfaced roads

A gravel layer of adequate thickness, laid over a subgrade, forms the most basic structure of aggregate surfaced roads. Since the pavement system of such roads consists of only a base layer, the thickness of this layer has considerable effects on the performance of the roads. In this study, both laboratory experiments and finite element analysis were conducted to evaluate the performance of lime and cement treated base layers with different thicknesses. To achieve this, five types of lime and cement treated mixtures were defined, three of which were chosen and modelled as base layers with different thicknesses using the finite element software, PLAXIS. The PLAXIS models were then loaded, analysed and compared by vertical deformation under a specific load as well as the maximum applicable load. Analytical and numerical modelling of the lime and cement treated soils requires a number of soil parameters that are usually obtained from expensive and time-consuming laboratory experiments. An alternative method was proposed in this study, in which the soil parameters required for the finite element analysis were obtained from unconfined compressive strength tests, and estimated using the failure criteria available in existing literature. Results of this study showed that an increase in the base layer thickness leads to a reduction in the vertical deformation of the pavement system under a specific load; however, the increase in the thickness of the base layer does not necessarily result in the increase in bearing capacity of the pavement system

A novel variant of SLC26A4 and first report of the c.716T>A variant in Iranian pedigrees with non-syndromic sensorineural hearing loss

The autosomal recessive non-syndromic hearing loss (ARNSHL) can be associated with variants in solute carrier family 26, member 4 (SLC26A4) gene and is the second most common cause of ARNSHL worldwide. Therefore, this study aims to determine the contribution of the SLC26A4 genotype in the hearing loss (HL) of 40 ARNSHL pedigrees in Iran. A cohort of the 40 Iranian pedigrees with ARNSHL, having no mutation in the GJB2 gene, was selected. The linkage analysis with five short tandem repeat (STR) markers linked to SLC26A4 was performed for the 40 ARNSHL pedigrees. Then, two out of the 40 pedigrees with ARNSHL that linked to DFNB4 locus were further screened to determine the variants in all exons of SLC26A4 gene by direct DNA sequencing. The 21 exons of SCL26A4 were analyzed for the two pedigrees. A known variant (c.716T>A homozygote), it is the first reported incidence in Iran, a novel variant (c.493A>C homozygote) were detected in the two pedigrees and pathogenesis of c.493A>C confirmed in this study with review 100 hearing ethnically matched controls by PCR-RFLP analysis. The present study suggests that the SLC26A4 gene plays a crucial role in the HL occurring in Iranian pedigrees. Also, the results probably support the specificity and unique spectrum of SLC26A4 variants among Iranian HL patients. Molecular study of SLC26A4 gene may lead to elucidation of the profile of the population-specific variants which has importance in diagnostics of HL

Electrically Small Supergain Arrays

The theory, computer simulations, and experimental measurements are presented for electrically small two-element supergain arrays with near optimal endfire gains of 7 dB. We show how the difficulties of narrow tolerances, large mismatches, low radiation efficiencies, and reduced scattering of electrically small parasitic elements are overcome by using electrically small resonant antennas as the elements in both separately driven and singly driven (parasitic) two-element electrically small supergain endfire arrays. Although rapidly increasing narrow tolerances prevent the practical realization of the maximum theoretically possible endfire gain of electrically small arrays with many elements, the theory and preliminary numerical simulations indicate that near maximum supergains are also achievable in practice for electrically small arrays with three (and possibly more) resonant elements if the decreasing bandwidth with increasing number of elements can be tolerated.Comment: 10 pages, 11 figures, submitted to IEEE Transactions on Antennas and Propagation (December 2006

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

Background and Objectives: : Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: : Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: : A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: : Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this populatio

The serious games ecosystem: Interdisciplinary and intercontextual praxis

This chapter will situate academia in relation to serious games commercial production and contextual adoption, and vice-versa. As a researcher it is critical to recognize that academic research of serious games does not occur in a vaccum. Direct partnerships between universities and commercial organizations are increasingly common, as well as between research institutes and the contexts that their serious games are deployed in. Commercial production of serious games and their increased adoption in non-commercial contexts will influence academic research through emerging impact pathways and funding opportunities. Adding further complexity is the emergence of commercial organizations that undertake their own research, and research institutes that have inhouse commercial arms. To conclude, we explore how these issues affect the individual researcher, and offer considerations for future academic and industry serious games projects

Evaluation of the performance of lime and cement treated base layers in unpaved roads

Mechanical properties of road subgrades and pavement layers, which consequently result in better performance, both in paved and unpaved roads. In this study, both laboratory experiments and finite element analysis were conducted to evaluate the performance of lime and cement treated base layers on soft clay subgrade. To achieve this, a number of mixtures with different lime and cement contents were defined and modelled, using finite element software, namely PLAXIS, as base layers under different loadings. The models were then analysed and compared in terms of vertical deformation under loads and the maximum applicable load. Analytical and numerical modelling of lime and cement treated soils require a number of soil parameters, which are usually obtained from expensive and time-consuming laboratory experiments. An alternative method was proposed in this study, in which the soil parameters required for the finite element analysis were obtained from the unconfined compressive strength tests, and estimated using the estimating functions available in available literature. The results of this study have showed that the application of the mixture with the highest modulus of elasticity for a base layer does not necessarily result in a pavement with the greatest bearing capacity. Rather, a correspondence should exist between the stiffness of the subgrade and that of the base layer

Paraoxonase-1 L55M Polymorphism with Fatty Acid Composition of Phospholipids in High-Density Lipoproteins

Background: Paraoxonase-1 (PON1) moves with high-density lipoprotein (HDL) particles in blood and prevents low-density lipoprotein (LDL) particles from oxidation. The aims of this study were to investigate the correlation between fatty acid composition of HDL phospholipids with pon-1 polymorphisms and response to lovastatin treatment in people with high blood cholesterol. Methods: In this descriptive study, 265 patients were selected and divided into two groups based on LDL-C concentrations; 131 patients with LDL-C greater than 130 mg/dl (cases) and 134 patients with LDL-C lower than 130 mg/dl (controls). Fatty acids of HDL phospholipids were measured with gas chromatography and lipid profile (cholesterol, triglyceride, LDL-C, HDL-C), apolipoprotein A1 and apolipoprotein B were measured by relevant commercial kits. Oxidized LDL was measured by ELISA method and activity of paraoxonase was determined by a relevant standard manual method. Genotypes of L55M polymorphism were determined by polymerase chain reaction-restriction fragment length polymorphism procedure. Results: Prevalence of L allele from L55M polymorphism was 0.65 and 0.53 in the case and control groups, respectively (P=0.04). PON1 paraoxonase activity in LL homozygote genotype was higher than other genotypes upon treatment with lovastatin. Concentrations of oleic, linoleic and eicosapentaenoic acids in LL genotype were increased by lovastatin administration. Conclusion: Allele (L) from L55M polymorphism had a higher frequency in patients with higher LDL-C concentrations. PON1 genotypes seemed to have a modifying role on paraoxonase-1 activity after lovastatin therapy