Publications by authors named "Paul Ley"

Article Synopsis
  • * Researchers describe the first complete mitogenome of an enoplian nematode, Campydora demonstrans, which shows a unique structure reminiscent of chloroplast genomes in land plants, differing from other nematode lineages.
  • * This work enhances the mtDNA representation within Nematoda and supports using the cox1 gene as a valuable tool for understanding nematode evolutionary relationships.
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Biocrusts are the living skin of drylands, comprising diverse microbial communities that are essential to desert ecosystems. Despite there being extensive knowledge on biocrust ecosystem functions and lichen and moss biodiversity, little is known about factors structuring diversity among their microbial communities. We used amplicon-based metabarcode sequencing to survey microbial communities from biocrust surface and subsurface soils at four sites located within the Mojave Desert.

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A post-traumatic, infected, non-union of a long bone is a significant challenge to orthopaedic surgeons, especially in zones of conflict and humanitarian settings. We describe a 32-year-old man treated with the two-stage Masquelet procedure for an infected non-union, and the processes required to achieve clinical bony union. The initial injury was a gunshot wound through the left proximal tibia, which lay untreated for three months before the first definitive surgical procedure.

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Background: Symbioses between metazoans and microbes are widespread and vital to many ecosystems. Recent work with several nematode species has suggested that strong associations with microbial symbionts may also be common among members of this phylu. In this work we explore possible symbiosis between bacteria and the free living soil bacteriovorous nematode Acrobeloides maximus.

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Microbial eukaryotes (nematodes, protists, fungi, etc., loosely referred to as meiofauna) are ubiquitous in marine sediments and probably play pivotal roles in maintaining ecosystem function. Although the deep-sea benthos represents one of the world's largest habitats, we lack a firm understanding of the biodiversity and community interactions amongst meiobenthic organisms in this ecosystem.

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Contrary to textbook dogma, nematodes are not only highly diverse, but often also complex and biologically specialized metazoans. Just a few of the many fascinating adaptations are reviewed in this chapter, as a prelude to a quick tour through phylogenetic relationships within the phylum. Small Subunit rDNA sequences have confirmed several controversial prior hypotheses, as well as revealing some unexpected relationships, resulting in a recent proposal for revised classification.

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Phylogenetic reconstructions of relations within the phylum Nematoda are inherently difficult but have been advanced with the introduction of large-scale molecular-based techniques. However, the most recent revisions were heavily biased towards terrestrial and parasitic species and greater representation of clades containing marine species (e.g.

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Nematodes of the suborder Cephalobina include an ecologically and morphologically diverse array of species that range from soil-dwelling microbivores to parasites of vertebrates and invertebrates. Despite a long history of study, certain of these microbivores (Cephaloboidea) present some of the most intractable problems in nematode systematics; the lack of an evolutionary framework for these taxa has prevented the identification of natural groups and inhibited understanding of soil biodiversity and nematode ecology. Phylogenetic analyses of ribosomal (LSU) sequence data from 53 taxa revealed strong support for monophyly of taxa representing the Cephaloboidea, but do not support the monophyly of most genera within this superfamily.

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Molecular surveys of meiofaunal diversity face some interesting methodological challenges when it comes to interstitial nematodes from soils and sediments. Morphology-based surveys are greatly limited in processing speed, while barcoding approaches for nematodes are hampered by difficulties of matching sequence data with traditional taxonomy. Intermediate technology is needed to bridge the gap between both approaches.

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Article Synopsis
  • New properties of external fixators, like dynamization and improved stability, are enhancing their use in treating children's lower limb fractures, making them more of a standard treatment option rather than just a choice.
  • A study of 21 children with lower limb fractures revealed benefits such as lower infection rates, effective healing without additional surgeries, and simpler physiotherapy and wound care.
  • However, there are potential complications associated with external fixators, including vascular injuries, pin tract infections, and unintentional fractures.
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Phylogenies were inferred from nearly complete small subunit (SSU) 18S rDNA sequences of 12 species of Meloidogyne and 4 outgroup taxa (Globodera pallida, Nacobbus abberans, Subanguina radicicola, and Zygotylenchus guevarai). Alignments were generated manually from a secondary structure model, and computationally using ClustalX and Treealign. Trees were constructed using distance, parsimony, and likelihood algorithms in PAUP* 4.

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Morphological identification and detailed observation of nematodes usually requires permanent slides, but these are never truly permanent and often prevent the same specimens to be used for other purposes. To efficiently record the morphology of nematodes in a format that allows easy archiving, editing, and distribution, we have assembled two micrographic video capture and editing (VCE) configurations. These assemblies allow production of short video clips that mimic multifocal observation of nematode specimens through a light microscope.

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Restriction fragment length polymorphism and direct sequencing of the internal transcribed spacer rDNA region of 19 isolates of Radopholus similis yielded significant diversity, both among isolates and within some individuals. Restriction fragment length polymorphism with HaeIII, AluI and Tru9I yielded two sets of patterns. Digestion with RsaI revealed one or two supernumerary bands in single nematodes from five isolates, and sequencing confirmed microheterogeneity in four of these.

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