117,275 research outputs found

    Amberlite XAD-4 is a convenient tool for removing Triton X-100 and Sarkosyl from protein solutions

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    Amberlite has been shown to be an appropriate material for the adsorption of organic contaminants from aqueous solutions. In addition, Amberlite XAD-2 has been successfully used, as an alternative to Bio-Beads, to remove Triton X-100 from protein solutions, such as from samples of solubilized membrane proteins. However, Amberlite has not been tested as an adsorbent when a mixture of detergents is necessary to solubilize and refold a target protein. Here the authors show that Amberlite XAD-4 can be appropriately used to aid the purification process of proteins solubilized from inclusion bodies with the ternary detergent system consisting of Sarkosyl, Triton X-100 and CHAPS

    High-yield production in Escherichia coli and convenient purification of a candidate vaccine against SARS-CoV-2

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    Objectives: The aim of the present work was to identify a time-saving, effective, and low-cost strategy to produce in Escherichia coli a protein chimera representing a fusion anti-SARS-CoV-2 candidate vaccine, consisting of immunogenic and antigenic moieties. Results: We overexpressed in E. coli BL21(DE3) a synthetic gene coding for CRM197-RBD, and the target protein was detected in inclusion bodies. CRM197-RBD was solubilized with 1 % (w/v) of the anionic detergent N-lauroylsarcosine (sarkosyl), the removal of which from the protein solution was conveniently accomplished with Amberlite XAD-4. The detergent-free CRM197-RBD was then separated from contaminating DNA using polyethylenimine (PEI), and finally purified from PEI by salting out with ammonium sulfate. Structural (CD spectrum) and functional (DNase activity) assays revealed that the CRM197-RBD chimera featured a native and active conformation. Remarkably, we determined a yield of purified CRM197-RBD equal to 23 mg per litre of culture. Conclusions: To produce CRM197-RBD, we devised the use of sarkosyl as an alternative to urea to solubilize the target protein from E. coli inclusion bodies, and the easy removal of sarkosyl by means of Amberlite XAD-4

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?

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    In this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We 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

    Letter from unknown writer to Jesse L. Boyce

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    Letter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing

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    Hear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing. Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal. Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp

    Lillian L. Lambert, Author, Speaker, and Entrepreneur

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    Lillian L. Lambert, Author, Speaker, and Entrepreneu

    Letter to Alfred L. Shoemaker, February 10, 1948

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    A handwritten letter from an unknown author addressed to Alfred L. Shoemaker, dated February 10, 1948. Within, the author discusses the Pennsylvania Dutch word for Ash Wednesday, along with traditions associated with this day.https://digitalcommons.ursinus.edu/shoemaker_documents/1118/thumbnail.jp
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