1,720,958 research outputs found
Leaf area is stimulated in Populus by free air CO2 enrichment (POPFACE), through increased cell expansion and production
No full textThe effects of free-air CO2 enrichment (FACE) on leaf growth in Populus, was studied. For the first time in field conditions, both the production and expansion of leaf cells were shown to be sensitive to atmospheric carbon dioxide. Leaf area expansion rate and final leaf size were stimulated under FACE for three species (Populus x euramericana (I-214), P. nigra (Jean Pourtet) and P. alba (2AS-11), with the largest effect observed for P. x euramericana (61%). In this species and in P. nigra, both epidermal cell size and cell number were increased, whereas for P. alba, only cell production was increased in FACE. Two findings suggest that changes in the cell wall may be important in explaining larger leaf cells in FACE: (i) Leaf cell wall extensibility of rapidly growing leaves increased in all species in FACE; and (ii) an increase in xyloglucan endotransglycosylase activity, a cell wall-loosening enzyme, was increased in FACE and associated with leaf growth rate. The results suggest that the mechanisms by which FACE promotes leaf growth differ, depending on species. Despite this, increases in final leaf size provide an important component driving increased biomass accumulation in POPFACE, during this first year of rapid growth, prior to canopy closure. The question as to whether these effects are the result of a direct response to CO2, or are driven indirectly through substrate availability remains unresolved, although evidence from the literature suggests that the latter mechanism is most likely
Functional expression of AtHMA4, a P-1B-type ATPase of the Zn/Co/Cd/Pb subclass
No full textMechanisms are required by all organisms to maintain the concentration of essential heavy metals (e.g. Zn and Cu) within physiological limits and to minimise the detrimental effects of non-essential heavy metals (e.g. Cd). Heavy-metal P-type ATPases (HMAs) are a subgroup of the P-type ATPase superfamily that may contribute to metal homeostasis in plants. We cloned and characterised a member of this family, AtHMA4, from Arabidopsis thaliana that clusters with the Zn/Co/Cd/Pb subclass of HMAs on phylogenetic analysis. Sequencing of the AtHMA4 cDNA showed that it contained the conserved motifs found in all P-type ATPases and also motifs that are characteristic of heavy-metal ATPases. Escherichia coli mutants defective in the HMAs, CopA and ZntA , were used in functional complementation studies. AtHMA4 was able to restore growth at high [Zn] in the zntA mutant but not at high [Cu] in the copA mutant, suggesting a role in zinc transport. Heterologous expression of AtHMA4 in Saccharomyces cerevisiae made the yeast more resistant to Cd but did not affect sensitivity to other metals compared with vector-transformed controls. The organ specificity of AtHMA4 was analysed in Arabidopsis and showed that AtHMA4 was expressed in a range of tissues with highest expression in roots. AtHMA4 was upregulated in roots exposed to elevated levels of Zn and Mn but downregulated by Cd. Possible physiological roles of this transporter in Arabidopsis are discussed. <br/
The Reconstruction of Proto-South-Sulawesi
No full textIII. 1) Roger F. Mills (University of Michigan) mengadakan perban- dingan dari beberapa bahasa (atau golongan bahasa) di Sula- wesi-Selatan : Makasar, Bugis, bahasa-bahasa Massénrémpulu', Mandar, bahasa-bahasa Pitu Ulunna Salu, dan Sa'dan. Dengan jelas penulis menunjukkan hubungan yang dekat, dengan pengaruh yang sporadis dan kecil sekali dari "Substratum" yang mungkin ada, yang barangkali berhubungan dengan bahasa-bahasa Sulawesi-Tengah. Penulis kemudian memberikan pendapatnya tentang hubungan fonologis, yang dapat dilihat dengan mengadakan perbandingan kata-kata yang bersamaan artinya dari berbagai bahasa tersebut. Penulis pada akhirnya mengemukakan penyusunan kembali sebagian dari perbenda- haraan kata bahasa yang menjadi dasar bahasa-bahasa tersebut dan yang disebut "proto-South-Sulawesi".III. 1) Roger F. Mills (University of Michigan) compares here the various languages (or groups of languages) of the South Celebes : Makassar, Bugis, the languages of Massénrémpulu', Mandar, the languages of the Pitu Ulunna Salu, and the "Sa'dan", for whom he clearly proves the close affiliation, only slightly clouded by the sporadic influence of an eventual substrate which may have some connection with the languages of central Celebes. The author then fixes the discernable phonetic correspondances by comparison of related words in these various languages, and by way of a conclusion proposes a highly-probable reconstruction of a part of the vocabulary of the original common language which he designates by the name of "Proto-South-Sulawesi".III. 1) Roger F. Mills (University of Michigan) compare ici les diverses langues (ou groupes de langues) de Célèbes-Sud : Makassar, Bugis, langues des Massénrépulu', Mandar, langues des Pitu Ulunna Salu, et "Sa'dan", dont il montre avec évidence l'étroite parenté, à peine troublée par l'influence sporadique d'un éventuel substrat qui pourrait avoir eu quelque rapport avec les langues de Célèbes-Centre. L'auteur détermine ensuite les correspondances phonologiques discernables par la comparaison de mots apparentés de ces diverses langues, et propose finalement une reconstruction hautement probable d'une partie du vocabulaire de la langue originelle commune qu'il désigne sous le nom de "Proto-South-Sulawesi".Mills R.F. The Reconstruction of Proto-South-Sulawesi. In: Archipel, volume 10, 1975. pp. 205-224
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
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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