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Oral subchronic exposure to silver nanoparticles in rats, DOI: 10.1016/j.fct.2016.04.010, Because of their extremely small size, silver nanoparticles (AgNPs) show unique physical and chemical properties, with specific biological effects, which make them particularly attractive for being used in a number of consumer applications. However, these properties also influence the potential toxicity of AgNPs. In this study, we assessed the potential toxic effects of an in vivo oral sub-chronic exposure to polyvinyl pyrrolidone coated AgNPs (PVP-AgNPs) in adult male rats. We also assessed if oral PVP-AgNPs exposure could alter the levels of various metals (Fe, Mg, Zn and Cu) in tissues. Rats were orally given 0, 50, 100 and 200 mg/kg/day of PVP-AgNPs. Silver (Ag) accumulation in tissues, Ag excretion, biochemical and hematological parameters, metal levels, as well as histopathological changes and subcellular distribution following PVP-AgNPs exposure, were also investigated. After 90 days of treatment, AgNPs were found within hepatic and ileum cells. The major tissue concentration of Ag was found in ileum of treated animals. However, all tissues of PVP-AgNPs-exposed animals showed increased levels of Ag in comparison with those of rats in the control group. No harmful effects in liver and kidney, as well as in biochemical markers were noted at any treatment dose. In addition, no hematological or histopathological changes were found in treated animals. However, significant differences in Cu and Zn levels were found in thymus and brain of PVP-AgNPs-treated rats.

The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence of a sex-biased, admixed genetic background. This work further explores the genetics of the Greenlanders by analysing autosomal and X-chromosomal data to obtain deeper insights into the factors that shaped the genetic diversity in Greenlanders. Fourteen Greenlandic subsamples from multiple geographical settlements were compared to assess the level of genetic substructure in the Greenlandic population. The results showed low levels of genetic diversity in all sets of the genetic markers studied, together with an increased number of X-chromosomal loci in linkage disequilibrium in relation to the Danish population. In the broader context of worldwide populations, Greenlanders are remarkably different from most populations, but they are genetically closer to some Inuit groups from Alaska. Admixture analyses identified an Inuit component in the Greenlandic population of approximately 80%. The sub-populations of Ammassalik and Nanortalik are the least diverse, presenting the lowest levels of European admixture. Isolation-by-distance analyses showed that only 16% of the genetic substructure of Greenlanders is most likely to be explained by geographic barriers. We suggest that genetic drift and a differentiated settlement history around the island explain most of the genetic substructure of the population in Greenland.European Journal of Human Genetics advance online publication, 7 May 2014; doi:10.1038/ejhg.2014.90.

Mitochondrial genomes are generally thought to be under selection for compactness, due to their small size, consistent gene content, and a lack of introns or intergenic spacers. As more animal mitochondrial genomes are fully sequenced, rearrangements and partial duplications are being identified with increasing frequency, particularly in birds (Class Aves). In this study, we investigate the evolutionary history of mitochondrial control region states within the avian order Psittaciformes (parrots and cockatoos). To this aim, we reconstructed a comprehensive multi-locus phylogeny of parrots, used PCR of three diagnostic fragments to classify the mitochondrial control region state as single or duplicated, and mapped these states onto the phylogeny. We further sequenced 44 selected species to validate these inferences of control region state. Ancestral state reconstruction using a range of weighting schemes identified six independent origins of mitochondrial control region duplications within Psittaciformes. Analysis of sequence data showed that varying levels of mitochondrial gene and tRNA homology and degradation were present within a given clade exhibiting duplications. Levels of divergence between control regions within an individual varied from 0–10.9% with the differences occurring mainly between 51 and 225 nucleotides 3′ of the goose hairpin in domain I. Further investigations into the fates of duplicated mitochondrial genes, the potential costs and benefits of having a second control region, and the complex relationship between evolutionary rates, selection, and time since duplication are needed to fully explain these patterns in the mitochondrial genome.

[EN] This study demonstrates that Anthemis chrysantha, a 'Critically Endangered' annual plant, produces two morphs of achenes: white and dark achenes, which differ in size, mass, anatomy and germination behaviour. Fresh white achenes germinated at all temperatures assayed from 10 to 25 degrees C in both continuous darkness and 12-h photoperiod, ranging between 24% at 25 degrees C in darkness and 89% at 12/20 degrees C in light, whereas fresh dark achenes did not germinate under any temperature or light conditions. To identify differences in dormancy type between the two morphs, germination of dry-stored achenes, and achenes stratified at 5 or 25 degrees C for 2 months were tested in both darkness and light at 5, 15 and 12/20 degrees C for dry-stored and warm-stratified (25 degrees C) achenes; and at 15, 25 and 12/20 degrees C for cold-stratified (5 degrees C) achenes. Of the white achenes, 90% germinated during the cold stratification period. In general, dry storage and warm stratification did not increase germination compared to fresh achenes. However, dark achenes did not germinate under any conditions. Dark achene dormancy was only broken by mechanical scarification or by excising the embryo (germination reached 71%). An anatomical study showed that the mesocarp of dark achenes had no intercellular spaces and was much thicker and stronger than that of white achenes, making the entry of water difficult, and also preventing germination by mechanical restriction. This study demonstrated that dormancy in the dark achenes is likely caused by the thickness of their pericarp, physically impeding germination and hampering imbibition of water.

Vehicle-to-vehicle (V2V) communications have seen growing attention in the last few years. In this work, we address the use of the 3GPP Long Term Evolution (LTE) standard technology applied to V2V. We employ empirical models for the V2V channel, and show results from comprehensive computer simulations, based upon both the uplink (UL) and downlink (DL) standards for LTE. We provide results for 10 MHz and 20 MHz channels, in terms of BER, BLER, spectral efficiency and throughput, using multiple MIMO modes. Results show the attractive feasibility of the LTE technology in V2V communication systems. © 2011 IEEE.

Prediction of human eye colour by forensic genetic methods is of great value in certain crime investigations. Strong associations between blue/brown eye colour and the SNP loci rs1129038 and rs12913832 in the HERC2 gene were recently described. Weaker associations between eye colour and other genetic markers also exist. In 395 randomly selected Danes, we investigated the predictive values of various combinations of SNP alleles in the HERC2, OCA2 and MATP (SLC45A2) genes and compared the results to the eye colours as they were described by the individuals themselves. The highest predictive value of typing either the HERC2 SNPs rs1129038 and/or rs12913832 that are in strong linkage disequilibrium was observed when eye colour was divided into two groups, (1) blue, grey and green (light) and (2) brown and hazel (dark). Sequence variations in rs11636232 and rs7170852 in HERC2, rs1800407 in OCA2 and rs16891982 in MATP showed additional association with eye colours in addition to the effect of HERC2 rs1129038. Diplotype analysis of three sequence variations in HERC2 and one sequence variation in OCA2 showed the best discrimination between light and dark eye colours with a likelihood ratio of 29.3.

Udgivelsesdato: 2010-May-18, BACKGROUND: The analysis of X-chromosome markers can be valuable in particular situations, for example, deficiency kinship cases, where the putative father cannot be typed. X-chromosome short-tandem repeats (X-STRs) are widely used in forensic genetics, while the use of X-chromosome single-nucleotide polymorphisms (X-SNPs) is still limited. STUDY DESIGN AND METHODS: The forensic usefulness of a set of 25 SNPs located across the X-chromosome was analyzed in 13 populations. The applicability of the 25 X-SNPs in kinship testing was illustrated in two immigration cases where the conclusions based on the analysis of 15 autosomal STRs were ambiguous and, in one of the cases, misleading. The samples in the two cases were also typed for eight X-STRs, 52 autosomal SNPs, and seven autosomal variable number of tandem repeats. RESULTS: The combined power of discrimination of the 25 X-chromosome markers varied from one in 1.7 x 10(6) males to one in 7.8 x 10(9) females and the combined mean chance of exclusion varied between 99.78% in duos to 99.998% in trios. In the two immigration cases, the use of X-linked markers increased the number of genetic inconsistencies and the cases could be solved. The usefulness of X-chromosome markers was particularly illustrative in Case 1, where the typing of 25 X-SNPs would have been sufficient to exclude paternity. CONCLUSION: The high level of polymorphism, low degree of linkage disequilibrium, and very low probability of mutation of the 25 X-SNPs makes this set of markers suitable as a supplementary set of markers in relationship testing.

With the aim to establish a Y-STR haplotype database, a total of 554 males from seven Western Mediterranean populations were genotyped for the 12 Y-chromosome STR loci (minimal haplotype extended by loci DYS437, DYS438 and DYS439) included in the Powerplex Y System (Promega). Among the 554 males analyzed, 443 different haplotypes were obtained, of which 372 were unique. The other haplotypes were shared by two to seven men. The two most frequent haplotypes were both found in seven Ibiza men. A remarkable haplotype diversity of 0.9988á¦á0.0002 was observed. The haplotypes were searched against the Y-haplotype reference database (YHRD) and 149 haplotypes matched to at least one YHRD sample

We have developed a PCR multiplex method that in a fast, inexpensive and reliable manner can detect if a person has two, one or no GSTM1 and GSTT1 genes and which at the same time can detect the allelic status of the GSTP1 Ile105Val genetic variant. A total of 200 Danes, 100 Somalis and 100 Greenlanders were genotyped. This multiplex PCR assay enables future large-scale studies to investigate the role of GSTs

Udgivelsesdato: 2008-Dec, The MC1R gene encodes a protein with key regulatory functions in the melanin synthesis. A multiplex PCR and a multiplex single base extension protocol were established for genotyping six exonic MC1R variations highly penetrant for red hair (R), four exonic MC1R variations weakly penetrant for red hair (r), two frameshift variations highly penetrant for red hair (R) and three variations in the promoter region. We genotyped 600 individuals from Denmark using either CE or MALDI-TOF MS as the detection platform. A total of 62 individuals were genotyped R/R and among the 62 individuals, 57 had red hair and five had blond hair colour. Two different R alleles may be located in cis (RR/-) position or trans (R/R) position, and the phenotype associated with RR/- and R/R may be different. Two allele-specific PCRs were established with primers targeting the -G445A variation in the MC1R promoter and the allele-specific PCR products were used in the multiplex single base extension assay. In all 62 individuals, the MC1R variants were situated in trans position. Another 18 individuals with red hair colour were either genotyped R/- or R/r, suggesting that other genes influence hair colour.

Udgivelsesdato: 2008-Apr-3, The timing of the first human migration into the Americas and its relation to the appearance of the Clovis technological complex in North America ca. 11-10.8 thousand radiocarbon years before present ((14)C ka B.P.) remains contentious. We establish that humans were present at Paisley 5 Mile Point Caves, south-central Oregon, by 12,300 (14)C yr. B.P., through recovery of human mtDNA from coprolites, directly dated by accelerator mass spectrometry. The mtDNA corresponds to Native American founding haplogroups A2 and B2. The dates of the coprolites are >1000 (14)C years earlier than currently accepted dates for the Clovis-complex.

Extensive collections of formalin-fixed paraffin-embedded (FFPE) tissues exist that could be exploited for genetic analyses in order to provide important insights into the genetic basis of disease or host/pathogen cointeractions. We report here an evaluation of a 44 SNP multiplex genotyping method, multiplex PCR with minisequencing (MPMS), on 92 DNA extractions performed on six archival FFPE samples of variable DNA quality, which date between 9 and 25 years old. On the three extracts with highest quality, we found the assay efficiency to be near 100%. However, the efficiency of the lowest quality extracts varied significantly. In this study, we demonstrate that although direct measures of DNA concentration in the extracts provide no useful information with regard to subsequent MPMS success, the success of the assay can be determined to some degree a priori, through initial screening of the DNA quality using a simple quantitative real-time PCR (qPCR) assay for nuclear DNA, and/or an assay of the maximum PCR amplifiable size of nuclear DNA. MPMS promises to be of significant use in future genetic studies on FFPE material. It provides a streamlined approach for retrieving a large amount of genetic information using simple, single reactions and minute amounts of archival tissue/DNA. In the light of this evidence, we suggest that the systematic screening of FFPE collections may in the future provide valuable insights into the past. Udgivelsesdato: 2007-Jul