672 research outputs found

    Gregarious settlement by the larvae of Hydroides dianthus (Polychaeta, Serpulidae)

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    Also published as: Marine Ecology Progress Series 5 (1981): 69-74Larval development of the serpulid polychaete worm, Hydroides dianthus Verrill 1893 parallels that of other closely related species. The larvae prefer to settle upon surfaces already inhabited by other members of their own species rather than to colonize surfaces without such conspecific residents. However, very wide variations in the intensity of settlement are observed. These differences in the amount of settlement cannot presently be attributed to any single variable. Gregarious settlement appears to be typical for sessile species which do not have the ability to reproduce asexually after settlement.Prepared for the Office of Naval Research under Contract N00014-79-C-0071; NR 083-004 and for the National Science Foundation under Grant EAR-7926381

    Metabolomics to unveil and understand phenotypic diversity between pathogen populations

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    Visceral leishmaniasis is caused by a parasite called Leishmania donovani, which every year infects about half a million people and claims several thousand lives. Existing treatments are now becoming less effective due to the emergence of drug resistance. Improving our understanding of the mechanisms used by the parasite to adapt to drugs and achieve resistance is crucial for developing future treatment strategies. Unfortunately, the biological mechanism whereby Leishmania acquires drug resistance is poorly understood. Recent years have brought new technologies with the potential to increase greatly our understanding of drug resistance mechanisms. The latest mass spectrometry techniques allow the metabolome of parasites to be studied rapidly and in great detail. We have applied this approach to determine the metabolome of drug-sensitive and drug-resistant parasites isolated from patients with leishmaniasis. The data show that there are wholesale differences between the isolates and that the membrane composition has been drastically modified in drug-resistant parasites compared with drug-sensitive parasites. Our findings demonstrate that untargeted metabolomics has great potential to identify major metabolic differences between closely related parasite strains and thus should find many applications in distinguishing parasite phenotypes of clinical relevance

    Utilization of multiparametric prostate magnetic resonance imaging in clinical practice and focal therapy: report from a Delphi consensus project

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    To codify the use of multiparametric magnetic resonance imaging (mpMRI) for the interrogation of prostate neoplasia (PCa) in clinical practice and focal therapy (FT). An international collaborative consensus project was undertaken using the Delphi method among experts in the field of PCa. An online questionnaire was presented in three consecutive rounds and modified each round based on the comments provided by the experts. Subsequently, a face-to-face meeting was held to discuss and finalize the consensus results. mpMRI should be performed in patients with prior negative biopsies if clinical suspicion remains, but not instead of the PSA test, nor as a stand-alone diagnostic tool or mpMRI-targeted biopsies only. It is not recommended to use a 1.5 Tesla MRI scanner without an endorectal or pelvic phased-array coil. mpMRI should be performed following standard biopsy-based PCa diagnosis in both the planning and follow-up of FT. If a lesion is seen, MRI-TRUS fusion biopsies should be performed for FT planning. Systematic biopsies are still required for FT planning in biopsy-naïve patients and for patients with residual PCa after FT. Standard repeat biopsies should be taken during the follow-up of FT. The final decision to perform FT should be based on histopathology. However, these consensus statements may differ for expert centers versus non-expert centers. The mpMRI is an important tool for characterizing and targeting PCa in clinical practice and FT. Standardization of acquisition and reading should be the main priority to guarantee consistent mpMRI quality throughout the urological communit

    Pair-matched patient-reported quality of life and early oncological control following focal irreversible electroporation versus robot-assisted radical prostatectomy

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    Purpose: The design, conduct and completion of randomized trials for curative prostate cancer (PCa) treatments are challenging. To evaluate the effect of robot-assisted radical prostatectomy (RARP) versus focal irreversible electroporation (IRE) on patient-reported quality of life (QoL) and early oncological control using propensity-scored matching. Methods: Patients with T1c–cT2b significant PCa (hig

    Probabilistic assignment of formulas to mass peaks in metabolomics experiments

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    <b>Motivation</b>: High-accuracy mass spectrometry is a popular technology for high-throughput measurements of cellular metabolites (metabolomics). One of the major challenges is the correct identification of the observed mass peaks, including the assignment of their empirical formula, based on the measured mass.<p></p> <b>Results</b>: We propose a novel probabilistic method for the assignment of empirical formulas to mass peaks in high-throughput metabolomics mass spectrometry measurements. The method incorporates information about possible biochemical transformations between the empirical formulas to assign higher probability to formulas that could be created from other metabolites in the sample. In a series of experiments, we show that the method performs well and provides greater insight than assignments based on mass alone. In addition, we extend the model to incorporate isotope information to achieve even more reliable formula identification.<p></p&gt

    Hard and soft anatomy in two genera of Dondersiidae (Mollusca, Aplacophora, Solenogastres)

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    Author Posting. © Marine Biological Laboratory, 2012. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 222 (2012): 233-269.Phylogenetic relationships and identifications in the aplacophoran taxon Solenogastres (Neomeniomorpha) are in flux largely because descriptions of hard parts––sclerites, radulae, copulatory spicules––and body shape have often not been adequately illustrated or utilized. With easily recognizable and accessible hard parts, descriptions of Solenogastres are of greater use, not just to solenogaster taxonomists, but also to ecologists, paleontologists, and evolutionary biologists. Phylogenetic studies of Aplacophora, Mollusca, and the Lophotrochozoa as a whole, whether morphological or molecular, would be enhanced. As an example, morphologic characters, both isolated hard parts and internal anatomy, are provided for two genera in the Dondersiidae. Five species are described or redescribed and earlier descriptions corrected and enhanced. Three belong to Dondersia: D. festiva Hubrecht, D. incali (Scheltema), and D. namibiensis n. sp., the latter differentiated unambiguously from D. incali only by sclerites and copulatory spicules. Two species belong to Lyratoherpia: L. carinata Salvini-Plawen and L. californica (Heath). Notes are given for other species in Dondersiidae: L. bracteata Salvini-Plawen, Ichthyomenia ichthyodes (Pruvot), and Heathia porosa (Heath). D. indica Stork is synonymized with D. annulata. A cladistic morphological analysis was conducted to examine the utility of hard parts for reconstructing solenogaster phylogeny. Results indicate monophyly of Dondersia and Lyratoherpia as described here.Major funding was by a U. S. National Science Foundation grant (DEB-9521930) under the PEET program (Partnerships for Enhancing Expertise in Taxonomy)

    XGAP: a uniform and extensible data model and software platform for genotype and phenotype experiments.

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    We present an extensible software model for the genotype and phenotype community, XGAP. Readers can download a standard XGAP (http://www.xgap.org) or auto-generate a custom version using MOLGENIS with programming interfaces to R-software and web-services or user interfaces for biologists. XGAP has simple load formats for any type of genotype, epigenotype, transcript, protein, metabolite or other phenotype data. Current functionality includes tools ranging from eQTL analysis in mouse to genome-wide association studies in humans.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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