1,720,991 research outputs found
Determining the sub-cellular localization of proteins within Caenorhabditis elegans body wall muscle.
Get PDFDetermining the sub-cellular localization of a protein within a cell is often an essential step towards understanding its function. In Caenorhabditis elegans, the relatively large size of the body wall muscle cells and the exquisite organization of their sarcomeres offer an opportunity to identify the precise position of proteins within cell substructures. Our goal in this study is to generate a comprehensive "localizome" for C. elegans body wall muscle by GFP-tagging proteins expressed in muscle and determining their location within the cell. For this project, we focused on proteins that we know are expressed in muscle and are orthologs or at least homologs of human proteins. To date we have analyzed the expression of about 227 GFP-tagged proteins that show localized expression in the body wall muscle of this nematode (e.g. dense bodies, M-lines, myofilaments, mitochondria, cell membrane, nucleus or nucleolus). For most proteins analyzed in this study no prior data on sub-cellular localization was available. In addition to discrete sub-cellular localization we observe overlapping patterns of localization including the presence of a protein in the dense body and the nucleus, or the dense body and the M-lines. In total we discern more than 14 sub-cellular localization patterns within nematode body wall muscle. The localization of this large set of proteins within a muscle cell will serve as an invaluable resource in our investigation of muscle sarcomere assembly and function
Membrane extensions are associated with proper anterior migration of muscle cells during Caenorhabditis elegans embryogenesis
No full textC. elegans body wall muscle is formed after a series of well-orchestrated steps. With the onset of specification embryonic muscle cells accumulate under the hypodermal seam cells at the left and right sides of the embryo. Shortly thereafter they begin to migrate dorsally and ventrally resting beneath the dorsal and ventral hypodermis eventually forming the four muscle quadrants present upon hatching. In this study we describe the plasma membrane dynamics of these migrating cells and observe the extension of filopodia and lamellipodia during dorso-ventral migration but not during the earlier stages of accumulation. We also describe an anterior migration event during embryonic muscle morphogenesis, whereby the anterior-most pair of cells in each of the four muscle quadrants extends long processes to the anterior tip of the developing embryo. Anteriormost muscle cells then follow these extensions into their final positions in the developing embryo. Using RNAi and mutant analysis, we have identified laminin as being involved in mediating the dorsal-ventral muscle migrations. Finally we show that the α-integrin INA-1, the ephrin VAB-2 and its receptor VAB-1 and the Robo receptor SAX-3 indirectly promote the proper extension of the ventral anterior muscle processes by organizing the embryonic neurons so as to provide a clear path for muscle membrane extension.Peer reviewedfinal article publishedsax-3LamininC. elegansMuscleCell migrationina-1vab-
Discovery and characterization of novel manganese-selective cation diffusion facilitators as putative anthelminthic drug targets in Caenorhabditis elegans
No full textParasitic nematodes infect over 1.5 billion people worldwide and are a burden on the agricultural
and veterinary industries. Widespread use of the few available classes of anthelmintics have led
to the development of anthelmintic resistance amongst these parasitic helminths. It is imperative
that we find new therapeutics to address the looming threat of anthelminthic resistance. One
method for developing new chemotherapies is through rational drug design. Using C. elegans as
a surrogate for parasitic nematodes, we have taken the first steps to identify and characterize a
small group of putatively druggable “nematode-specific” proteins by generating null mutants and
endogenously-tagged reporters using CRISPR-Cas9 gene-editing technology. To our knowledge,
this work is the first to define a family of novel manganese-selective cation diffusion facilitators
in C. elegans. Although these are not essential proteins and are unlikely to be good drug targets,
their newly discovered role in manganese tolerance advances our knowledge of the mechanisms
that underlie manganese biology and toxicity.Medicine, Faculty ofGraduat
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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