Pattern formation on carbon nanotube surfaces

Calculations of fluorine binding and migration on carbon nanotube surfaces show that fluorine forms varying surface superlattices at increasing temperatures. The ordering transition is controlled by the surface migration barrier for fluorine atoms to pass through next neighbor sites on the nanotube, explaining the transition from semi-ionic low coverage to covalent high coverage fluorination observed experimentally for gas phase fluorination between 200 and 250°C. The effect of solvents on fluorine binding and surface diffusion is explored

Ab initio infrared vibrational modes for neutral and charged small fullerenes (C 20 , C 24 , C 26 , C 28 , C 30 and C 60 )

International audienc

Ab initio infrared vibrational modes for neutral and charged small fullerenes (C20, C24, C26, C28, C30 and C60)

We calculate the infrared (IR) absorption spectra using DFT B3LYP(6–311G) for a range of small closed-cage fullerenes, Cn, n=20, 24, 26, 28, 30 and 60, in both neutral and multiple positive and negative charge states. The results are of use, notably, for direct comparison with observed IR absorption in the interstellar medium. Frequencies fall typically into two ranges, with C−C stretch modes around 1100–1500 cm−1 (6.7–9.1 μm) and fullerene-specific radial motion associated with under-coordinated carbon at pentagonal sites in the range 600–800 cm−1 (12.5–16.7 μm). Notably, negatively charged fullerenes show significantly stronger absorption intensities than neutral species. The results suggest that small cage fullerenes, and notably metallic endofullerenes, may be responsible for many of the unassigned interstellar IR spectral lines

Allelic heterogeneity of Crooked Tail Syndrome: result of balancing selection?

peer reviewed« RILOUKE ! » Tares et Pathologies à Composante Héréditaire en Race Blanc-Bleu Belge, Vers le Développement d’un Réseau Intégré de Lutt

Confounding factors affecting faecal egg count reduction tests for anthelmintic efficacy

Anthelmintic resistance (AR) is a major global problem in livestock and humans and increasingly drives parasite management decisions. Assessment of AR relies on the faecal egg count reduction test (FECRT). Despite technical improvements to the FECRT and its interpretation, multiple confounding factors can affect results yet are usually ignored, such as pharmacokinetic behaviour among drugs, parasites, and host types and individuals that affecting the therapeutic anthelmintic response; helminth demographics affecting test repeatability; and technical errors. Confounding factors are numerous, highly likely to occur in farm environments, and rarely possible to control. Evaluation of AR in practical and research settings should attempt to reduce and account for confounders in FECRT and, where possible, consider trends in observed efficacy against a background of natural variation. To examine this aim, simulations were performed based on species identification data within FECRT for nematodes in sheep and cattle, to quantify the effects of variation in species composition on AR classification. Results show that misclassification is likely to be common and could account for seasonal inconsistency in FECRT outcomes. Improved methods for species identification have the potential to greatly improve FECRT accuracy. Pharmacokinetic and pharmacodynamic confounders are more difficult to surmount, and it is already widely recommended to reduce their influence where possible, and consider their potential role in cases of treatment failure. Given the frequency of pharmacokinetic / pharmacodynamic drivers of reduced anthelmintic efficacy in livestock, however, repeated assessment is an important tool to detect trends and reach robust conclusions. Simulations are extended to consider the relative value of thorough but rare FECRT, and frequent but imprecise forms of FECR-based monitoring, to provide early warning of AR. This approach shows the limitations of optimising FERCT for maximum technical accuracy. Holistic and pragmatic consideration of anthelmintic efficacy is needed to provide evidence to support farm decisions.Fil: Morgan, Eric. The Queens University of Belfast; IrlandaFil: Lanusse, Carlos Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Rinaldi, Laura. Università degli Studi di Napoli Federico II; ItaliaFil: Charlier, Johannes. No especifíca;Fil: Henry, Nicole. The Queens University of Belfast; IrlandaFil: McFarland, Chris. The Queens University of Belfast; IrlandaFil: Airs, Paul. The Queens University of Belfast; IrlandaFil: Vercruysse, Jozef. University of Ghent; Bélgica28th International Conference of the World Association for the Advancement of Veterinary ParasitologyDublinIrlandaWorld Association for the Advancement of Veterinary ParasitologyUniversity College of Dubli

KCNQ2 and KCNQ3 potassium channel genes in benign familial neonatal convulsions: expansion of the functional and mutation spectrum.

Benign familial neonatal convulsions (BFNC) is a rare autosomal dominant generalized epilepsy of the newborn infant. Seizures occur repeatedly in the first days of life and remit by approximately 4 months of age. Previously our laboratory cloned two novel potassium channel genes, KCNQ2 and KCNQ3, and showed that they are mutated in patients with BFNC. In this report, we characterize the breakpoints of a previously reported interstitial deletion in the KCNQ2 gene and show that only KCNQ2 is deleted. We identify 11 novel mutations in KCNQ2 and one novel mutation in the KCNQ3 potassium channel genes. In one family, the phenotype extends beyond neonatal seizures and includes rolandic seizures, and a subset of families has onset of seizures in infancy. In the Xenopus oocyte expression system, we characterize five KCNQ2 and one KCNQ3 disease-causing mutations. These mutations cause a variable loss of function, and selective effects on the biophysical properties of KCNQ2/KCNQ3 heteromultimeric channels. We report here the first dominant negative mutation in KCNQ2 that has a phenotype of neonatal seizures without permanent clinical CNS impairment

Higher male than female recombination rate in cattle is controlled by genetic variants effective in both sexes

We herein study genetic recombination in three dairy cattle populations from France, New-Zealand and the Netherlands. We apply a new phasing algorithm extracting familial information suited for large half-sib families to reconstruct haplotypes and detect cross-overs (CO). The software is robust to genotyping and map errors. We identify more than 2,000,000 CO events in sperm cells transmitted by 3008 sires to 94,603 offspring, and more than 500,000 CO events in oocytes transmitted by 11,497 cows to 25,390 offspring. When measured in identical family structures, the average number of CO in males (24.0) was found to be larger than in females (21.8). In males, recombination rates were higher closer to telomeres whereas in females, recombination rates dropped at both centromeres and telomeres (probably as a result of lower informativity). The heritability of the global recombination rate (GRR) was close to 0.20 in males and to 0.08 in females. Genetic correlation ranged from 0.38 to 0.69 depending on the population, indicating that shared variants are influencing GRR in both genders. Haplotype-based genome-wide association studies revealed four genome-wide significant QTL, including two previously identified ones (involving REC8 and RNF212). For all QTLs, there was a positive correlation between haplotype effects across sexes, ranging from 0.35 to 0.68. We selected two reference panels of respectively 122 and 215 bulls sequenced at cover > 15x to impute variants in the New-Zealand and French populations. All variants identified by next-generating sequencing in 5 Mb windows encompassing the QTL peaks were imputed with Beagle in order to perform a sequence-based association study. For three QTLs, we identified missense mutations in genes known to be involved in meiosis among the most significantly associated variants. These variants were perfectly associated with the haplotypes underlying the QTL effects. The variant identified in RNF212 had already been reported, whereas missense mutations in MLH3 (N408S) and HFM1 (S1189L) are new findings. Surprisingly, variants previously identified in REC8 did not capture the QTL effect whereas variants in RNF212B, PPP1R3E, BCL2L2, HOMEZ and PABPN1 had much stronger association with the phenotype. The three missense mutations were significant in both genders with two of them accounting for approximately 10% of the genetic variance in males (the allelic substitution effect being approximately equal to one additional CO per genome). Our results are very different from reports of recombination in other species. For instance, in human, recombination rate is higher in females, distinct variants affect recombination rate in males and females and the genetic correlation is close to 0 whereas in cattle, we observed a higher recombination rate in males controlled by shared variants effective in both sexes