1,721,082 research outputs found
Copper metabolism and gut morphology in rainbow trout (Oncorhynchus mykiss) during chronic sublethal dietary copper exposure
No full textJuvenile rainbow trout (Oncorhynchus mykiss) were exposed to 11 (control), 300 (medium), and 1000 mug Cu.g(1) (high) (as CuSO(4)5H(2)O) in the diet for 28 days at a daily ration of 4% wet body weight, with a background waterborne Cu concentration of 3 mug.L-1. There was no effect of dietary Cu on growth, condition factor, or food conversion efficiency. Whole-body Cu content increased continuously over the exposure period in all groups and was twofold and fourfold higher than controls at day 28 for the medium- and high-Cu diets, respectively. Copper accumulated mainly in liver and gut tissue, with the latter stabilizing by day 14. Accumulation also occurred in gill, kidney, and carcass. Plasma Cu concentration was not different from the controls whereas Cu in bile was greatly elevated, an indication of increased hepatobiliary excretion. Dietary Cu pre-exposure decreased the uptake of waterborne Cu across the gills, providing the first evidence of homeostatic interaction between the two routes of uptake. Electron microscopic observations of the midintestine revealed numerous mitochondria, lysosomes, lamellated bodies, and extensive lamellar processes in the enterocytes. Apoptosis, mitosis, and eosinophilic granule cells were more apparent in Cu-exposed fish.PT: J; CR: BERNTSSEN MHG, 1999, AQUAT TOXICOL, V46, P87 CAMPBELL HA, 1999, AQUAT TOXICOL, V46, P177 COLMAN JR, 1979, SCANNING ELECT MICRO, V11, P801 CRESPO S, 1986, J FISH BIOL, V28, P68 DALLINGER R, 1985, OECOLOGIA, V67, P82 DALLINGER R, 1987, OECOLOGIA, V73, P91 EZEASOR DN, 1980, J FISH BIOL, V17, P529 FARAG AM, 1994, ENVIRON TOXICOL CHEM, V13, P2021 GATLIN DM, 1986, AQUACULTURE, V54, P277 GROSELL M, 2000, IN PRESS AM J PHYSL GROSELL MH, 1997, AQUAT TOXICOL, V38, P257 GROSELL MH, 1998, AQUAT TOXICOL, V40, P275 GUASTADISEGNI C, 1999, J TOXICOL ENV HEAL A, V57, P415 HANDY RD, 1992, ARCH ENVIRON CON TOX, V22, P74 HANDY RD, 1993, AQUAT TOXICOL, V27, P1 HANDY RD, 1996, TOXICOLOGY AQUATIC P, P29 HANDY RD, 1999, AQUAT TOXICOL, V47, P23 HUGHES GM, 1984, FISH PHYSIOL, V10, P1 JULSHAMN K, 1988, AQUACULTURE, V73, P143 LANNO RP, 1985, AQUACULTURE, V49, P257 LANNO RP, 1987, AQUAT TOXICOL, V10, P251 LULLMANNRAUCH R, 1979, LYSOSOMES APPLIED BI, V6, P49 MACRAE RK, 1999, ENVIRON TOXICOL CHEM, V18, P1180 MARR JCA, 1996, AQUAT TOXICOL, V36, P17 MCDONALD DG, 1993, FISH ECOPHYSIOLOGY, P270 MILLER PA, 1993, CAN J FISH AQUAT SCI, V50, P1683 MOUNT DR, 1994, ENVIRON TOXICOL CHEM, V13, P2031 MURAI T, 1981, AQUACULTURE, V22, P352 NONNOTTE L, 1986, CELL TISSUE RES, V243, P619 OGINO C, 1980, NIPPON SUISAN GAKK, V46, P455 TAYLOR LN, 2000, ENVIRON TOXICOL CHEM, V19, P2298 WEIS P, 1986, ENVIRON HEALTH PERSP, V65, P167 WOLF K, 1963, PROGRE FISH CULT, V25, P135 WOOD CM, 1992, AQUAT TOXICOL, V22, P239 WOODWARD DF, 1994, T AM FISH SOC, V123, P51 WOODWARD DF, 1995, CAN J FISH AQUAT SCI, V52, P1994; NR: 36; TC: 24; J9: CAN J FISHERIES AQUAT SCI; PG: 13; GA: 399WRSource type: Electronic(1
Cytosolic carbonic anhydrase in the Gulf toadfish is important for tolerance to hypersalinity.
No full textCarbonic anhydrase (CA) is a ubiquitous enzyme involved in acid-base regulation and osmoregulation. Many studies have demonstrated a role for this enzyme in fish osmoregulation in seawater as well as freshwater. However, to date CA responses of marine fish exposed to salinities exceeding seawater (similar to 35 ppt) have not been examined. Consequently, the aim of the present study was to examine CA expression and activity in osmoregulatory tissues of the Gulf Toadfish, Opsanus beta, following transfer to 60 ppt. A gene coding, for CAc of 1827 bp with an open reading frame of 260 amino acids was cloned and showed high expression in all intestinal segments and gills. CAc showed higher expression in posterior intestine and rectum than in anterior and mid intestine and in gills of fish exposed to 60 ppt for up to 4 days. The enzymatic activity, in contrast, was higher in all examined tissues two weeks following transfer to 60 ppt. Comparing early expression and later activity levels of acclimated fish reveals a very different response to hypersalinity among tissues. Results highlight a key role of CAc in osmoregulation especially in distal regions of the intestine; moreover, CAc play a role in the gill in hypersaline environments possibly supporting elevated branchial acid extrusion seen under such conditions
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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