1,723,314 research outputs found
15 Years : Goldstein Goodman Post 6909
Goldstein-Goodman Post 6909, Veterans of Foreign Wars of the United States was started on May 2, 1946 at the Jewish Community Center in Toledo, Ohio. The Post was a community service organization run by Jewish veterans. This book outlines the history of the Post and highlights its members
Quorum sensing in the cyanobacterium Gloeothece PCC 6909.
The thesis sought to study whether cyanobacteria utilise the process of quorum sensing during their growth, to identify any quorum sensing molecules produced by the cyanobacteria Gloeothece PCC 6909/1 and to study the effect of any such molecules in aexenic cultures of the organism. The study presents the first evidence of N-octanoyl homoserine lactone (C8-HSL) quorum sensing molecule from axenic cultures of the cyanobacterium PCC 6909 and its sheathless mutant PCC 6909/1 and that the production of this molecule followed a density dependent accumulation, a common feature of many quorum sensing systems. The response of the Gloeothece proteome to exogenous concentrations of C8-HSL was examined, indicating changes in 43 protein spots on a 2D-PAGE gel, thereby indicating a response through global changes in protein expression. Among the 15 proteins that showed more than 2 fold expression changes, RuBisCo, glutamate synthase, chorismate synthase, a LysR family of transcriptional regulator (all up regulated) enolase and aldolase (down regulated) could be identified. A number of phosphorylated proteins also showed increased accumulation suggesting changes in the phosphoproteome of Gloeothece. A response to C8-HSL was also detected in physiological changes of the organism through decreased accumulation of extracellular soluble carbohydrates and an increased acid phosphatase activity from cell extracts. In conclusion, this study presents evidence that the cyanobacterium Gloeothece employs a C8-HSL based quorum sensing system through the accumulation and response to a C8-HSL signal. These findings can help increase our understanding of how colonial cyanobacteria encounter stress at high cell densities
Effect of sulfur starvation on the morphology and ultrastructure of the cyanobacterium gloeothece sp. PCC 6909
Gloeothece sp. PCC 6909 is a unicellular, nitrogen-fixing cyanobacterium that accumulates sulfate in its sheath. An ultrastructural study of sulfate- deficient and normal Gloeothece sp. PCC 6909 cells was carried out. The physiological alterations, caused by sulfur starvation, were related to important morphological alterations in the cell: a structureless sheath, accumulation of cyanophycin, polyhydroxybutyrate and glycogen granules, and disintegration of thylakoidal membranes. Most of these changes were reversed by the addition of sulfate to the culture medium. The important role of sulfate in the sheath structure was demonstrated.Peer Reviewe
20th anniversary, Goldstein-Goodman Post 6909, V. F. W.
Goldstein-Goodman Post 6909, Veterans of Foreign Wars of the United States was started on May 2, 1946 at the Jewish Community Center in Toledo, Ohio. The Post was a community service organization run by Jewish veterans. This book celebrates the organization's 20th anniversary, outlines the history of the Post, and highlights its members
Going Beyond Counting First Authors in Author Co-citation Analysis
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
Variations on the Author
“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
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
Dispelling the Myths Behind First-author Citation Counts
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
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