1,721,015 research outputs found
Involvement of H+-ATPase and carbonic anhydrase in inorganic carbon uptake for endosymbiont photosynthesis
No full textSymbiotic cnidarians absorb inorganic carbon from seawater to supply intracellular dinoflagellates with CO2 for their photosynthesis. To determine the mechanism of inorganic carbon transport by animal cells, we used plasma membrane vesicles prepared from ectodermal cells isolated from tentacles of the sea anemone, Anemonia viridis. H14CO3/- uptake in the presence of an outward NaCl gradient or inward H+ gradient, showed no evidence for a Cl- or H+- driven HCO3/- transport. H14CO3/- and 36Cl- uptakes were stimulated by a positive inside-membrane diffusion potential, suggesting the presence of HCO3/- and Cl- conductances. A carbonic anhydrase (CA) activity was measured on plasma membrane (4%) and in the cytoplasm of the ectodermal cells (96%) and was sensitive to acetazolamide (IC50 = 20 nM) and ethoxyzolamide (IC50 = 2.5 nM). A strong DIDS-sensitive H+ATPase activity was observed (IC50 = 14 μM). This activity was also highly sensitive to vanadate and allyl isothiocyanate, two inhibitors of P-type H+-ATPases. Present data suggest that HCO3/- absorption by ectodermal cells is carried out by H+ secretion by H+-ATPase, resulting in the formation of carbonic acid in the surrounding seawater, which is quickly dehydrated into CO2 by a membrane-bound CA. CO2 then diffuses passively into the cell where it is hydrated in HCO3/- by a cytosolic CA
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Production of wild Chlorella sp. cultivated in digested and membrane-pretreated swine manure derived from a full-scale operation plant
No full textA wild Chlorella sp.was isolated from amanure storage tank and then cultivated under semi-continuous production conditions on four substrates, including digested swine manure (DIG) and digestate-derived liquid fractions obtained by digestate centrifugation (CLF) and ultrafiltration (ULF) in a full-scale digestate treatment plant, in order to evaluate differences in growth and depuration capacities. The microalga was capable of fast growth on some of the substrates, comparable to that obtained with 3N-BBM synthetic medium, productivities being 0.21 g L-1 d-1 of biomass for ULF and 3N-BBM media, 0.17 g L-1 d-1 biomass for CLF media and 0.10 g L-1 d-1 biomass for DIG media. Algal growthwas affected, above all, by the chemical oxygen demand (COD) of the starting culture mediawhich directly affected turbidity and also light availability. Nutrient contents, i.e. N and P, did not seem to affect the process. Chlorella sp.was capable of reducing about 95%-98% of N-NH4 + and 61-73% of COD,while micronutrients were almost completely removed from the cultures. However, most of the ammonia nitrogen was lost to the atmosphere due to the stripping phenomena caused by aeration and high pH during algal growth, so that only 30% of the nitrogen was successfully incorporated in the microalgal biomass. The isolated Chlorella proved to be a strong strain, capable of reducing macro- and micronutrient contents in the digested liquid streams. The full-scale digestate membrane treatment proved to be a suitable process to integrate with microalgae cultivation, improving the growth medium performance in terms of final biomass productivity
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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