20 research outputs found

    A fluidic device for the controlled formation and real-time monitoring of soft membranes self-assembled at liquid interfaces

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    The work was supported by the European Research Council Starting Grant (STROFUNSCAFF) and the Marie Curie Career Integration Grant (BIOMORPH). L.B. acknowledges fnancial support from the European Community through grant no. 618335 ‘FlowMat: Flow and Capillarity in Materials Science’ and ERC Starting Grant FLEXNANOFLOW no. 715475. Te authors thank Karla E. Inostroza-Brito for the constructive support in this work

    Chronic ventricular pacing in children: toward prevention of pacing-induced heart disease

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    In children with congenital or acquired complete atrioventricular (AV) block, ventricular pacing is indicated to increase heart rate. Ventricular pacing is highly beneficial in these patients, but an important side effect is that it induces abnormal electrical activation patterns. Traditionally, ventricular pacemaker leads are positioned at the right ventricle (RV). The dyssynchronous pattern of ventricular activation due to RV pacing is associated with an acute and chronic impairment of left ventricular (LV) function, structural remodeling of the LV, and increased risk of heart failure. Since the degree of pacing-induced dyssynchrony varies between the different pacing sites, ‘optimal-site pacing’ should aim at the prevention of mechanical dyssynchrony. Especially in children, generally paced from a very early age and having a perspective of life-long pacing, the preservation of cardiac function during chronic ventricular pacing should take high priority. In the perspective of the (patho)physiology of ventricular pacing and the importance of the sequence of activation, this paper provides an overview of the current knowledge regarding possible alternative sites for chronic ventricular pacing. Furthermore, clinical implications and practical concerns of the various pacing sites are discussed. The review concludes with recommendations for optimal-site pacing in children

    Cisgenesis and intragenesis as new strategies for crop improvement

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    Cisgenesis and intragenesis are emerging plant breeding technologies which offer great promise for future acceptance of genetically engineered crops. The techniques employ traditional genetic engineering methods but are confined to transferring of genes and genetic elements between sexually compatible species that can breed naturally. One of the main requirements is the absence of selectable marker genes (such as antibiotic resistance genes) in the genome. Hence the sensitive issues with regard to transfer of foreign genes and antibiotic resistance are overcome. It is a targeted technique involving specific locus; therefore, linkage drag that prolongs the time for crop improvement in traditional breeding does not occur. It has great potential for crop improvement using superior alleles that exist in the untapped germplasm or wild species. Cisgenic and intragenic plants may not face the same stringent regulatory assessment for field release as transgenic plants which is a clear added advantage that would save time. In this chapter, the concepts of cis/intragenesis and the prerequisites for the development of cis/intragenesis plants are elaborated. Strategies for marker gene removal after selection of transformants are discussed based on the few recent reports from various plant species

    Avian β-defensin variation in bottlenecked populations : the Seychelles warbler and other congeners

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    β-defensins are important components of the vertebrate innate immune system responsible for encoding a variety of anti-microbial peptides. Pathogen-mediated selection is thought to act on immune genes and potentially maintain allelic variation in the face of genetic drift. The Seychelles warbler, Acrocephalus sechellensis, is an endemic passerine that underwent a recent bottleneck in its last remaining population, resulting in a considerable reduction in genome-wide variation. We genotyped avian β-defensin (AvBD) genes in contemporary (2000–2008) and museum samples (1876–1940) of the Seychelles warbler to investigate whether immunogenetic variation was lost through this bottleneck, and examined AvBD variation across four other Acrocephalus species with varying demographic histories. No variation was detected at four of the six AvBD loci screened in the post-bottleneck population of Seychelles warbler, but two silent nucleotide polymorphisms were identified at AvBD8 and one potentially functional amino-acid variation was observed at AvBD11. Variation in the Seychelles warbler was significantly lower than in the mainland migratory congeneric species investigated, but it similar to that found in other bottlenecked species. In addition, screening AvBD7 in 15 museum specimens of Seychelles warblers sampled prior to the bottleneck (1877–1905) revealed that this locus possessed two alleles previously, compared to the single allele in the contemporary population. Overall, the results show that little AvBD variation remains in the Seychelles warbler, probably as a result of having low AvBD diversity historically rather than the loss of variation due to drift associated with past demographic history. Given the limited pathogen fauna, this lack of variation at the AvBD loci may currently not pose a problem for this isolate population of Seychelles warblers, but it may be detrimental to the species’ long-term survival if new pathogens reach the population in the future

    Phylogenetic Properties of 50 Nuclear Loci in Medicago (Leguminosae) Generated Using Multiplexed Sequence Capture and Next-Generation Sequencing

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    Next-generation sequencing technology has increased the capacity to generate molecular data for plant biological research,including phylogenetics, and can potentially contribute to resolving complex phylogenetic problems. The evolutionaryhistory of Medicago L. (Leguminosae: Trifoliae) remains unresolved due to incongruence between published phylogenies.Identification of the processes causing this genealogical incongruence is essential for the inference of a correct speciesphylogeny of the genus and requires that more molecular data, preferably from low-copy nuclear genes, are obtainedacross different species. Here we report the development of 50 novel LCN markers in Medicago and assess the phylogeneticproperties of each marker. We used the genomic resources available for Medicago truncatula Gaertn., hybridisation-basedgene enrichment (sequence capture) techniques and Next-Generation Sequencing to generate sequences. This alternativeproves to be a cost-effective approach to amplicon sequencing in phylogenetic studies at the genus or tribe level andallows for an increase in number and size of targeted loci. Substitution rate estimates for each of the 50 loci are provided,and an overview of the variation in substitution rates among a large number of low-copy nuclear genes in plants ispresented for the first time. Aligned sequences of major species lineages of Medicago and its sister genus are made availableand can be used in further probe development for sequence-capture of the same markers
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