THE VARIABILITY OF MULTI-DRUG RESISTANCE ABCB1 GENE IN THE ROMA POPULATION FROM CROATIA

When overexpressed, a large transmembrane P-glycoprotein, the product of the ABCB1 gene, is a notable impediment to brain-targeted therapies (like antiepileptics) and chemotherapies. Some of the genetic biomarkers with evidence of multi-drug resistance in ABCB1 ― rs1045642, rs1128503, and rs3213619 ― were analyzed in 440 subjects, members of three socio-culturally different Roma (Gypsy) groups of Croatia. Minor allele frequencies (MAFs) of rs1045642 and rs1128503 were the highest in the Balkan Roma (63.6% and 69.4%, respectively) when compared to the Baranja (52.3% and 62.5%) and the Međimurje Roma (48.8% and 54.5%) (p=0.0005 and p=0.0011, respectively). rs3213619 was monomorphic in the Međimurje group, while its MAFs in other two Roma groups were very low (<1.9%). The distribution of five detected haplotypes (four in the Međimurje group) significantly differed between the Roma subpopulations (p<0.0001), just like the frequencies of diplotypes (p=0.0008). At a global scale, the positive relationship between genetic and geographic distances between the 21 investigated populations indicates isolation by spatial distance. However, this is not true for the relationship between Roma and other populations due to their population history. The analyzed ABCB1 loci indicate genetic distinctiveness of the Roma population

Genetic Variation at Nine Short Tandem Repeat Loci Among Islanders of the Eastern Adriatic Coast of Croatia

We have analyzed the extent of genetic variation at nine autosomal short tandem repeat loci (D3S1358, VWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, D7S820) among six populations from Croatia: five distributed in the islands of the eastern Adriatic coast and one from the mainland. The purpose is to investigate the usefulness of these loci in detecting regional genetic differentiation in the studied populations. Significant heterogeneity among the island and mainland populations is revealed in the distributions of allele frequencies; however, the absolute magnitude of the coefficient of gene differentiation is small but significant. The summary measures of genetic variation, namely, heterozygosity, number of alleles, and allele size variance, do not indicate reduced genetic variation in the island populations compared to the mainland population. In contrast to the two measures of genetic variation, allele size variance and within-locus heterozygosity, the imbalance index ( ) indicates evidence of recent expansion of population sizes in all islands and in the mainland. High mutation rates of the studied loci together with local drift effects are likely explanations for interisland genetic variation and the observed lack of reduced genetic diversity among the island populations

Influence of Nd3+: YAG laser irradiation on the properties of composites with carbon fibers

The carbon fiber based composites: carbon fiber reinforced plastic and 3D carbon fiber reinforced carbon composites were exposed to the Nd3+: YAG laser beams (1064 nm). Experimental parameters for the interaction of the laser beam with 1.5 Hz pulse frequency and with pulse duration 0.7 ms varied: energy density between 128 and 1915 J cm(-2), pulse energy from 1 to 3 J and mean power in the range between 0.4 and 6.5 kW. Apparently, the energy absorbed by the composite samples was mainly converted into thermal energy, causing a range of damages, from instantaneous evaporation to cracking and melting, which resulted in a crater-like damage. Program ImageJ was executed for quantitative analysis of generated damages based on micrographs obtained by SEM and light microscopes. Obtaied results enable identification of the laser induced changes in the material. (C) 2017 Elsevier Ltd. All rights reserved

Evaluation of laser beam interaction with carbon based material - glassy carbon

Laser beam interaction with carbon based material (glassy carbon) is analyzed in this paper. A Nd3+:YAG laser beam (1.06 mu m, i.e., near infrared range (NIR)) in ms regime with various energy densities is used. In all experiments, provided in applied working regimes, surface damages have occurred. The results of laser damages are analyzed by light and scanning electron microscopy (SEM). Image J software is used for quantitative analysis of generated damages based on micrographs obtained by light and SEM microscopes. Temperature distribution in the exposed samples is evaluated by numerical simulations based on COMSOL Multiphysics 3.5 software in a limited energy range

Characterization of laser beam interaction with carbon materials

This paper presents simulation and experimental results for the exposure of some carbon-based materials to alexandrite and Nd3+:YAG (yttrium aluminum garnet) laser radiation. Simulation of the heating effects was carried out using the COMSOL Multiphysics 3.5 package for samples of carbon-based P7295-2 fiber irradiated using an alexandrite laser and carbon-based P4396-2 fiber irradiated using an Nd3+:YAG laser, as well as by applying finite element modeling for P7295-2 samples irradiated using an Nd3+:YAG laser. In the experimental part, P7295-2 samples were exposed to alexandrite laser radiation while samples of carbon-based composite 3D C/C were exposed to Nd3+:YAG laser radiation. Micrographs of the laser induced craters were obtained by light and scanning electron microscopy, and the images analyzed using the ImageJ software. The results obtained enable identification of the laser-material interaction spots, and characterization of the laser induced changes in the materials investigated

3000 years of solitude: extreme differentiation in the island isolates of Dalmatia, Croatia

Communities with increased shared ancestry represent invaluable tools for genetic studies of complex traits. '1001 Dalmatians' research program collects biomedical information for genetic epidemiological research from multiple small isolated populations ('metapopulation') in the islands of Dalmatia, Croatia. Random samples of 100 individuals from 10 small island settlements (n<2000 inhabitants) were collected in 2002 and 2003. These island communities were carefully chosen to represent a wide range of distinct and well-documented demographic histories. Here, we analysed their genetic make-up using 26 short tandem repeat (STR) markers, at least 5 cM apart. We found a very high level of differentiation between most of these island communities based on Wright's fixation indexes, even within the same island. The model-based clustering algorithm, implemented in STRUCTURE, defined six clusters with very distinct genetic signatures, four of which corresponded to single villages. The extent of background LD, assessed with eight linked markers on Xq13-21, paralleled the extent of differentiation and was also very high in most of the populations under study. For each population, demographic history was characterised and 12 'demographic history' variables were tentatively defined. Following stepwise regression, the demographic history variable that most significantly predicted the extent of LD was the proportion of locally born grandparents. Strong isolation and endogamy are likely to be the main forces maintaining this highly structured overall population

Origin and Diffusion of mtDNA Haplogroup X

A maximum parsimony tree of 21 complete mitochondrial DNA (mtDNA) sequences belonging to haplogroup X and the survey of the haplogroup-associated polymorphisms in 13,589 mtDNAs from Eurasia and Africa revealed that haplogroup X is subdivided into two major branches, here defined as “X1” and “X2.” The first is restricted to the populations of North and East Africa and the Near East, whereas X2 encompasses all X mtDNAs from Europe, western and Central Asia, Siberia, and the great majority of the Near East, as well as some North African samples. Subhaplogroup X1 diversity indicates an early coalescence time, whereas X2 has apparently undergone a more recent population expansion in Eurasia, most likely around or after the last glacial maximum. It is notable that X2 includes the two complete Native American X sequences that constitute the distinctive X2a clade, a clade that lacks close relatives in the entire Old World, including Siberia. The position of X2a in the phylogenetic tree suggests an early split from the other X2 clades, likely at the very beginning of their expansion and spread from the Near East

Runs of Homozygosity in European Populations

Estimating individual genome-wide autozygosity is important both in the identification of recessive disease variants via homozygosity mapping and in the investigation of the effects of genome-wide homozygosity on traits of biomedical importance. Approaches have tended to involve either single-point estimates or rather complex multipoint methods of inferring individual autozygosity, all on the basis of limited marker data. Now, with the availability of high-density genome scans, a multipoint, observational method of estimating individual autozygosity is possible. Using data from a 300,000 SNP panel in 2618 individuals from two isolated and two more-cosmopolitan populations of European origin, we explore the potential of estimating individual autozygosity from data on runs of homozygosity (ROHs). Termed Froh, this is defined as the proportion of the autosomal genome in runs of homozygosity above a specified length. Mean Froh distinguishes clearly between subpopulations classified in terms of grandparental endogamy and population size. With the use of good pedigree data for one of the populations (Orkney), Froh was found to correlate strongly with the inbreeding coefficient estimated from pedigrees (r = 0.86). Using pedigrees to identify individuals with no shared maternal and paternal ancestors in five, and probably at least ten, generations, we show that ROHs measuring up to 4 Mb are common in demonstrably outbred individuals. Given the stochastic variation in ROH number, length, and location and the fact that ROHs are important whether ancient or recent in origin, approaches such as this will provide a more useful description of genomic autozygosity than has hitherto been possible