Search results for " polymorphism"
showing 10 items of 1028 documents
Crossed 2D versus Slipped 1D π-Stacking in Polymorphs of Crystalline Organic Thin Films
2019
Polymorphs of organic semiconductors are of great interest as they shed light to structure-property relationships. The full X-ray thin film structure analysis of two polymorphs (B, G) of an important n-type semiconducting dicyano-distyrylbenzene based small molecule (CN-TFPA) is reported. Drastically different structures of the monotropic phases are revealed, that is an uncommon 2D crossed π-stacked arrangement for the B-phase versus a 1D slipped π-stack for G. Both phases exhibit a layered structure in the (100) plane with high structural integrity, driven by the hydrophobic contacts of the terminal CF3 groups; as (100) coincides with the film surface, this allows for exfoliation by scotch…
Further investigations on populations of the deep-water blue and red shrimp Aristeus antennatus (Risso, 1816) (Decapoda, Dendrobranchiata), as inferr…
2012
The aim of this study was to integrate existing mitochondrial DNA data relating to the deep-sea blue and red shrimp Aristeus antennatus (Risso, 1816) with data obtained by Amplified Fragment Length Polymorphism (AFLP). A total of 145 AFLP polymorphic loci were scored in 236 specimens collected from one Atlantic and seven Mediterranean sample sites. AMOVA results revealed that the overall genetic variation among-populations was lower (11.81%) than within-populations (88.19%). The genetic variation between the Atlantic and Mediterranean samples was found to be not significant ( Φ CT = − 0 . 007 ; N.S.), indicating that the transition area between the Atlantic Ocean and the Mediterranean Sea d…
Education modulates the association of the FTO rs9939609 polymorphism with body mass index and obesity risk in the Mediterranean population
2012
Objective To define whether the rs9939609 FTO (fat mass and obesity associated) single nucleotide polymorphism (SNP) is associated with anthropometric measurements and its modulation by educational level in a Mediterranean population. Methods We studied 3 independent adult samples: a random sample (n = 1580) from the general population (GP), obese hospital patients (OHP) (n = 203) and elderly subjects (n = 1027) with high cardiovascular risk (HCR). Weight and height were directly measured. Education and physical activity (PA) were measured using questionnaires. Results The rs9939609 presented heterogeneous associations with BMI. In the GP, the minor A-allele was significantly associated wit…
Chromosomal location polymorphism of major rDNA sites in two Mediterranean populations of the killifih Aphanius fasciatus (Pisces: Cyprinodontidae)
2005
The chromosomes of the Mediterranean killifish, Aphanius fasciatus from two populations, the Lagoon of Venice (LV, 15 specimens) and the Lagoon ‘Stagnone di Marsala’ (Sicily) (SM, 48 specimens), have been investigated using conventional Ag-staining and fluorescent in situ hybridization (FISH) with 18S rDNA probe. The two methods revealed variation in the number of major rDNA sites ranging from 8 to 14 (LV) and from 1 to 4 (SM) per individual. The fact that each individual possessed its own number of sites implies that observed variation was structural. Moreover, overlapping of silver staining and FISH patterns demonstrated that all ribosomal genes were transcriptionally active in each speci…
Genetic Structure of Wild and Cultivated Olives in the Central Mediterranean Basin
2006
Background and Aims: Olive cultivars and their wild relatives (oleasters) represent two botanical varieties of Olea europaea subsp. europaea (respectively europaea and sylvestris). Olive cultivars have undergone human selection and their area of diffusion overlaps that of oleasters. Populations of genuine wild olives seem restricted to isolated areas of Mediterranean forests, while most other wild-looking forms of olive may include feral forms that escaped cultivation. Methods: The genetic structure of wild and cultivated olive tree populations was evaluated by amplified fragment length polymorphism (AFLP) markers at a microscale level in one continental and two insular Italian regions. Key…
Development of microbial populations in the anaerobic hydrolysis of grass silage for methane production
2010
Six batch leach bed (LB) reactors, installed in parallel and connected to a common upflow anaerobic sludge blanket reactor, were fed with grass silage and operated at 35 (+/-1) degrees C. The development and distribution of microorganisms, which firmly and loosely attached to solid materials, and presented in the leachate in the LB reactors, were investigated by 16S rRNA gene-based terminal restriction fragment length polymorphism and clone library analyses. The phylotypes and their relative abundance changed in the respective bacterial community throughout the 49-day run and showed differences between the communities. Large numbers of phylotypes were detected from day 10 onwards. On day 17…
The methylenetetrahydrofolate reductase C677T polymorphism and the risk of congenital heart diseases: a literature review
2014
Congenital Heart Diseases (CHDs) are the most commonand serious developmental anomaly and the leading non-infectious cause of mortality in the first year of life. Despite the advances in diagnosis and treatment, understanding of the developmental causes and aetiologies of CHDs has been limited. The hyperhomocysteinemia is one of the proved risk factors related to the occurrence of CHDs. The connection between cardiac defects, folate and hyperhomocysteinemia could be explained by a mutation in the methylenetetrahydrofolate reductase (MTHFR) gene. Indeed, the C677T MTHFR mutation produces a thermolabile variant of MTHFR with reduced enzymatic action resulting in higher plasma levels of homocy…
Rapid microarray-based typing of forensic SNPs
2006
The single base extension-tag array (SBE-Tag Array) method is carried out on glass slides and combines the specificity of minisequencing for SNP typing with the high throughput capacity of microarrays. Following multiplex PCR, a single tube SBE reaction is carried out, and the fluorescent labelled extension products are hybridized to the complementary DNA sequence tag (cTag) immobilized on a glass slide for locus-specific laser scan analysis. The aim is to prove and optimise the conventional microarray reaction on accuracy and efficiency for forensic applications. © 2005 Elsevier B.V. All rights reserved.
Analyzing Illumina Gene Expression Microarray Data from Different Tissues: Methodological Aspects of Data Analysis in the MetaXpress Consortium
2012
Microarray profiling of gene expression is widely applied in molecular biology and functional genomics. Experimental and technical variations make meta-analysis of different studies challenging. In a total of 3358 samples, all from German population-based cohorts, we investigated the effect of data preprocessing and the variability due to sample processing in whole blood cell and blood monocyte gene expression data, measured on the Illumina HumanHT-12 v3 BeadChip array. Gene expression signal intensities were similar after applying the log(2) or the variance-stabilizing transformation. In all cohorts, the first principal component (PC) explained more than 95% of the total variation. Technic…
Mutations in the rpoB and katG Genes Leading to Drug Resistance in Mycobacterium tuberculosis in Latvia
2002
ABSTRACT To characterize the genetic basis of drug resistance in Mycobacterium tuberculosis in Latvia, mutations involved in rifampin ( rpoB gene) and isoniazid ( katG gene) resistance in DNA from 19 drug-susceptible and 51 multidrug-resistant M. tuberculosis complex isolates were analyzed. The most frequent rpoB gene mutations found by the Line Probe assay were the S531L (14 of 34 isolates), D516V (7 of 34), H526D (4 of 34), and D516Y plus P535S (4 of 34) mutations. Direct sequencing of seven isolates with unclear results from Line Probe assay showed the presence of the L533P mutation and the Q510H plus H526Y (1 of 34) and D516V plus P535S (4 of 34) double mutations, neither of which has b…