121 research outputs found

    Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC): Compound heterozygous mutation in the claudin 16 (CLDN16) gene

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    <p>Abstract</p> <p>Background</p> <p>Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) is an autosomal recessive disorder of renal calcium and magnesium wasting frequently complicated by progressive chronic renal failure in childhood or adolescence.</p> <p>Methods</p> <p>A 7 year old boy was investigated following the findings of marked renal insufficiency and nephrocalcinosis in his 18-month old sister. He too was found to have extensive nephrocalcinosis with increased fractional excretion of magnesium: 12.4% (<4%) and hypercalciuria: 5.7 mmol (< 2.5/24 hours). He had renal impairment, partial distal renal tubular acidosis and defective urinary concentrating ability. Therapy with thiazide diuretics and magnesium supplements failed to halt the progression of the disorder. Both children subsequently underwent renal transplantation. Both children's parents are unaffected and there is one unaffected sibling.</p> <p>Results</p> <p>Mutation analysis revealed 2 heterozygous mutations in the claudin 16 gene <it>(CLDN16</it>) in both affected siblings; one missense mutation in exon 4: C646T which results in an amino acid change Arg216Cys in the second extracellular loop of <it>CLDN16 </it>and loss of function of the protein and a donor splice site mutation which changes intron 4 consensus splice site from 'GT' to 'TT' resulting in decreased splice efficiency and the formation of a truncated protein with loss of 64 amino acids in the second extracellular loop.</p> <p>Conclusion</p> <p>The mutations in <it>CLDN16 </it>in this kindred affect the second extra-cellular loop of claudin 16. The clinical course and molecular findings suggest complete loss of function of the protein in the 2 affected cases and highlight the case for molecular diagnosis in individuals with FHHNC.</p

    A Comprehensive DNA Barcode Library for the Looper Moths (Lepidoptera: Geometridae) of British Columbia, Canada

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    The construction of comprehensive reference libraries is essential to foster the development of DNA barcoding as a tool for monitoring biodiversity and detecting invasive species. The looper moths of British Columbia (BC), Canada present a challenging case for species discrimination via DNA barcoding due to their considerable diversity and limited taxonomic maturity.By analyzing specimens held in national and regional natural history collections, we assemble barcode records from representatives of 400 species from BC and surrounding provinces, territories and states. Sequence variation in the barcode region unambiguously discriminates over 93% of these 400 geometrid species. However, a final estimate of resolution success awaits detailed taxonomic analysis of 48 species where patterns of barcode variation suggest cases of cryptic species, unrecognized synonymy as well as young species.A catalog of these taxa meriting further taxonomic investigation is presented as well as the supplemental information needed to facilitate these investigations

    DNA Barcoding the Geometrid Fauna of Bavaria (Lepidoptera): Successes, Surprises, and Questions

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    BACKGROUND: The State of Bavaria is involved in a research program that will lead to the construction of a DNA barcode library for all animal species within its territorial boundaries. The present study provides a comprehensive DNA barcode library for the Geometridae, one of the most diverse of insect families. METHODOLOGY/PRINCIPAL FINDINGS: This study reports DNA barcodes for 400 Bavarian geometrid species, 98 per cent of the known fauna, and approximately one per cent of all Bavarian animal species. Although 98.5% of these species possess diagnostic barcode sequences in Bavaria, records from neighbouring countries suggest that species-level resolution may be compromised in up to 3.5% of cases. All taxa which apparently share barcodes are discussed in detail. One case of modest divergence (1.4%) revealed a species overlooked by the current taxonomic system: Eupithecia goossensiata Mabille, 1869 stat.n. is raised from synonymy with Eupithecia absinthiata (Clerck, 1759) to species rank. Deep intraspecific sequence divergences (>2%) were detected in 20 traditionally recognized species. CONCLUSIONS/SIGNIFICANCE: The study emphasizes the effectiveness of DNA barcoding as a tool for monitoring biodiversity. Open access is provided to a data set that includes records for 1,395 geometrid specimens (331 species) from Bavaria, with 69 additional species from neighbouring regions. Taxa with deep intraspecific sequence divergences are undergoing more detailed analysis to ascertain if they represent cases of cryptic diversity

    Supporting the Construction of Workflows for Biodiversity Problem-Solving Accessing Secure, Distributed Resources

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    In the Biodiversity World (BDW) project we have created a flexible and extensible Web Services-based Grid environment for biodiversity researchers to solve problems in biodiversity and analyse biodiversity patterns. In this environment, heterogeneous and globally distributed biodiversity-related resources such as data sets and analytical tools are made available to be accessed and assembled by users into workflows to perform complex scientific experiments. One such experiment is bioclimatic modelling of the geographical distribution of individual species using climate variables in order to explain past and future climate-related changes in species distribution. Data sources and analytical tools required for such analysis of species distribution are widely dispersed, available on heterogeneous platforms, present data in different formats and lack inherent interoperability. The present BDW system brings all these disparate units together so that the user can combine tools with little thought as to their original availability, data formats and interoperability. The new prototype BDW system architecture not only brings together heterogeneous resources but also enables utilisation of computational resources and provides a secure access to BDW resources via a federated security model. We describe features of the new BDW system and its security model which enable user authentication from a workflow application as part of workflow execution

    Congruence and diversity of butterfly-host plant associations at higher taxonomic levels

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    We aggregated data on butterfly-host plant associations from existing sources in order to address the following questions: (1) is there a general correlation between host diversity and butterfly species richness?, (2) has the evolution of host plant use followed consistent patterns across butterfly lineages?, (3) what is the common ancestral host plant for all butterfly lineages? The compilation included 44,148 records from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea) and 1,193 genera (66.3%). The overwhelming majority of butterflies use angiosperms as host plants. Fabales is used by most species (1,007 spp.) from all seven butterfly families and most subfamilies, Poales is the second most frequently used order, but is mostly restricted to two species-rich subfamilies: Hesperiinae (56.5% of all Hesperiidae), and Satyrinae (42.6% of all Nymphalidae). We found a significant and strong correlation between host plant diversity and butterfly species richness. A global test for congruence (Parafit test) was sensitive to uncertainty in the butterfly cladogram, and suggests a mixed system with congruent associations between Papilionidae and magnoliids, Hesperiidae and monocots, and the remaining subfamilies with the eudicots (fabids and malvids), but also numerous random associations. The congruent associations are also recovered as the most probable ancestral states in each node using maximum likelihood methods. The shift from basal groups to eudicots appears to be more likely than the other way around, with the only exception being a Satyrine-clade within the Nymphalidae that feed on monocots. Our analysis contributes to the visualization of the complex pattern of interactions at superfamily level and provides a context to discuss the timing of changes in host plant utilization that might have promoted diversification in some butterfly lineages

    Assessing the Value of DNA Barcodes and Other Priority Gene Regions for Molecular Phylogenetics of Lepidoptera

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    BACKGROUND: Despite apparently abundant amounts of observable variation and species diversity, the order Lepidoptera exhibits a morphological homogeneity that has provided only a limited number of taxonomic characters and led to widespread use of nucleotides for inferring relationships. This study aims to characterize and develop methods to quantify the value of priority gene regions designated for Lepidoptera molecular systematics. In particular, I assess how the DNA barcode segment of the mitochondrial COI gene performs across a broad temporal range given its number one position of priority, most sequenced status, and the conflicting opinions on its phylogenetic performance. METHODOLOGY/PRINCIPAL FINDINGS: Gene regions commonly sequenced for lepidoptera phylogenetics were scored using multiple measures across three categories: practicality, which includes universality of primers and sequence quality; phylogenetic utility; and phylogenetic signal. I found that alternative measures within a category often appeared correlated, but high scores in one category did not necessarily translate into high scores in another. The DNA barcode was easier to sequence than other genes, and had high scores for utility but low signal above the genus level. CONCLUSIONS/SIGNIFICANCE: Given limited financial resources and time constraints, careful selection of gene regions for molecular phylogenetics is crucial to avoid wasted effort producing partially informative data. This study introduces an approach to assessing the value of gene regions prior to the initiation of new studies and presents empirical results to help guide future selections

    Assessing the Value of DNA Barcodes for Molecular Phylogenetics: Effect of Increased Taxon Sampling in Lepidoptera

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    BACKGROUND: A common perception is that DNA barcode datamatrices have limited phylogenetic signal due to the small number of characters available per taxon. However, another school of thought suggests that the massively increased taxon sampling afforded through the use of DNA barcodes may considerably increase the phylogenetic signal present in a datamatrix. Here I test this hypothesis using a large dataset of macrolepidopteran DNA barcodes. METHODOLOGY/PRINCIPAL FINDINGS: Taxon sampling was systematically increased in datamatrices containing macrolepidopteran DNA barcodes. Sixteen family groups were designated as concordance groups and two quantitative measures; the taxon consistency index and the taxon retention index, were used to assess any changes in phylogenetic signal as a result of the increase in taxon sampling. DNA barcodes alone, even with maximal taxon sampling (500 species per family), were not sufficient to reconstruct monophyly of families and increased taxon sampling generally increased the number of clades formed per family. However, the scores indicated a similar level of taxon retention (species from a family clustering together) in the cladograms as the number of species included in the datamatrix was increased, suggesting substantial phylogenetic signal below the 'family' branch. CONCLUSIONS/SIGNIFICANCE: The development of supermatrix, supertree or constrained tree approaches could enable the exploitation of the massive taxon sampling afforded through DNA barcodes for phylogenetics, connecting the twigs resolved by barcodes to the deep branches resolved through phylogenomics

    Fissure Seal or Fluoride Varnish? A Randomized Trial of Relative Effectiveness

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    Fissure sealant (FS) and fluoride varnish (FV) are effective in preventing dental caries when compared with a no-treatment control. However, the relative clinical effectiveness of these interventions is uncertain. The objective of the study was to compare the clinical effectiveness of FS and FV in preventing dental caries in first permanent molars (FPMs) in 6- to 7-y-olds. The study design was a randomized clinical trial, with 2 parallel arms. The setting was a targeted-population program that used mobile dental clinics in schools located within areas of high social and economic deprivation in South Wales. A total of 1,016 children were randomized 1:1 to receive either FS or FV. Resin-based FS was applied to caries-free FPMs and maintained at 6-mo intervals. FV was applied at baseline and at 6-mo intervals for 3 y. The main outcome measures were the proportion of children developing caries into dentine (D4-6MFT) on any 1 of up to 4 treated FPMs after 36 mo. At 36 mo, 835 (82%) children remained: 417 in the FS arm and 418 in the FV arm. A smaller proportion of children who received FV (n = 73, 17.5%) versus FS (n = 82, 19.6%) developed caries into dentine on at least 1 FPM (odds ratio [OR] = 0.84; 95% CI, 0.59 to 1.21; P = 0.35), a nonstatistically significant difference between FS and FV treatments. The results were similar when the number of newly decayed teeth (OR = 0.86; 95% CI, 0.60 to 1.22) and tooth surfaces (OR = 0.85; 95% CI, 0.59 to 1.21) were examined. In a community oral health program, semiannual application of FV resulted in caries prevention that was not significantly different from that obtained by applying and maintaining FS after 36 mo (EudraCT: 2010-023476-23; ISRCTN: ISRCTN17029222)

    Seven HCI Grand Challenges

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    This article aims to investigate the Grand Challenges which arise in the current and emerging landscape of rapid technological evolution towards more intelligent interactive technologies, coupled with increased and widened societal needs, as well as individual and collective expectations that HCI, as a discipline, is called upon to address. A perspective oriented to humane and social values is adopted, formulating the challenges in terms of the impact of emerging intelligent interactive technologies on human life both at the individual and societal levels. Seven Grand Challenges are identified and presented in this article: Human-Technology Symbiosis; Human-Environment Interactions; Ethics, Privacy and Security; Well-being, Health and Eudaimonia; Accessibility and Universal Access; Learning and Creativity; and Social Organization and Democracy. Although not exhaustive, they summarize the views and research priorities of an international interdisciplinary group of experts, reflecting different scientific perspectives, methodological approaches and application domains. Each identified Grand Challenge is analyzed in terms of: concept and problem definition; main research issues involved and state of the art; and associated emerging requirements
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