1,721,241 research outputs found
PEMI Talks
No full textCome listen to students, faculty, and staff talk about the work they are passionate about. Modeled after TED Talks, PEMI Talks are 10-15 talks focused on Pedagogy, Entrepreneurship, Meaning, and Innovation. This session will energize and inspire you for the coming school year
Role of PemI in the Staphylococcus aureus PemIK toxin–antitoxin complex: PemI controls PemK by acting as a PemK loop mimic
No full textStaphylococcus aureus is a notorious and globally distributed pathogenic bacterium. New strategies to develop novel antibiotics based on intrinsic bacterial toxin–antitoxin (TA) systems have been recently reported. Because TA systems are present only in bacteria and not in humans, these distinctive systems are attractive targets for developing antibiotics with new modes of action. S. aureus PemIK is a type II TA system, comprising the toxin protein PemK and the labile antitoxin protein PemI. Here, we determined the crystal structures of both PemK and the PemIK complex, in which PemK is neutralized by PemI. Our biochemical approaches, including fluorescence quenching and polarization assays, identified Glu20, Arg25, Thr48, Thr49, and Arg84 of PemK as being important for RNase function. Our study indicates that the active site and RNA-binding residues of PemK are covered by PemI, leading to unique conformational changes in PemK accompanied by repositioning of the loop between β1 and β2. These changes can interfere with RNA binding by PemK. Overall, PemK adopts particular open and closed forms for precise neutralization by PemI. This structural and functional information on PemIK will contribute to the discovery and development of novel antibiotics in the form of peptides or small molecules inhibiting direct binding between PemI and PemK.11Nsciescopusothe
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
The role of PemIK (PemK/PemI) type II TA system from Klebsiella pneumoniae clinical strains in lytic phage infection
Get PDFSince their discovery, toxin-antitoxin (TA) systems have captivated the attention of many scientists. Recent studies have demonstrated that TA systems play a key role in phage inhibition. The aim of the present study was to investigate the role of the PemIK (PemK/PemI) type II TA system in phage inhibition by its intrinsic expression in clinical strains of Klebsiella pneumoniae carrying the lncL plasmid, which harbours the carbapenemase OXA-48 and the PemK/PemI TA system. Furthermore, induced expression of the system in an IPTG-inducible plasmid in a reference strain of K. pneumoniae ATCC10031 was also studied. The results showed that induced expression of the whole TA system did not inhibit phage infection, whereas overexpression of the pemK toxin prevented early infection. To investigate the molecular mechanism involved in the PemK toxin-mediated inhibition of phage infection, assays measuring metabolic activity and viability were performed, revealing that overexpression of the PemK toxin led to dormancy of the bacteria. Thus, we demonstrate that the PemK/PemI TA system plays a role in phage infection and that the action of the free toxin induces a dormant state in the cells, resulting in inhibition of phage infections
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
Pengaruh Ekstrak Kulit Kayu Manis (Cinnamomum burmanii) Terhadap Kadar Malondialdehida Darah, Aktivitas Katalase dan Gambaran Histopatologi Pankreas Pada Tikus Hiperglikemia
Get PDFABSTRAK
PENGARUH EKSTRAK KULIT KAYU MANIS (Cinnamomum burmanii) TERHADAP KADAR MALONDIALDEHIDA DARAH, AKTIVITAS KATALASE DAN GAMBARAN HISTOPATOLOGI PANKREAS PADA TIKUS HIPERGLIKEMIA
Oleh : Pemi Perisnawati (2120312010)
Dibawah bimbingan : Prof. Dr. Eti Yerizel, MS dan dr. Tofrizal, Sp.PA, M.Biomed, PhD
Hiperglikemia merupakan suatu kondisi peningkatan kadar glukosa darah melebihi batas normal dikarenakan tubuh tidak memproduksi insulin atau insulin tidak bekerja dengan baik yang dapat memicu stres oksidatif. Kulit Kayu manis dapat meningkatkan kapasitas antioksidan dan menurunkan penanda stres oksidatif. Penelitian ini bertujuan untuk mengetahui pengaruh ekstrak kulit kayu manis terhadap marker oksidatif dan histopatologi pankreas pada tikus hiperglikemia.
Penelitian ini menggunakan rancangan eksperimental dengan post test only group design. Tikus dibagi menjadi 5 kelompok yaitu kelompok kontrol negatif (K-), kelompok kontrol positif (K+), kelompok perlakuan 1 (dosis 100 mg/kgBB), perlakuan 2 (dosis 200 mg/kgBB) dan perlakuan 3 (dosis 300 mg/kgBB) dengan masing-masing sejumlah 6 tikus. Uji normalitas dilakukan menggunakan Shapiro-Wilk test dilanjutkan dengan One Way ANOVA.
Pemberian ekstrak kulit kayu manis terbukti mampu menurunkan kadar Malondialdehida darah dimana penurunan yang terbaik pada Dosis 1 dengan rerata 2,31 nmol/ml lebih rendah dibanding K+ yaitu 4,88 nmol/ml. Aktivitas katalase pada kelompok yang diberi ekstrak kulit kayu manis terjadi peningkatan, dimana peningkatan yang paling baik pada kelompok dosis 1 dengan rerata mencapai 5,62 Unit/mg lebih tinggi dibanding K+ yaitu 3,88 Unit/mg. Gambaran histopatologi pankreas yang diberi ekstrak kulit kayu manis terjadi perbaikan dibandingkan dengan kelompok kontrol positif.
Pemberian ekstrak kulit kayu terbukti mampu menurunkan kadar Malondialdehida (MDA), meningkatkan aktivitas katalase, dan memperbaiki histopatologi pancreas pada tikus hiperglikemia.
Kata Kunci : Hiperglikemia, Malondialdehyde, Aktivitas Katalase, Histopatologi Pankreas
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
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