1,721,024 research outputs found
Removal And Insertion Of Pollinia In Flowers Of Oxypetalum (asclepiadaceae) In Southeastern Brazil
No full textPollinarium removal and pollinium insertion of seven Oxypetalum species (O. alpinum var. alpinum, O. appendiculatum, O. banksii subsp. banksii, O. jacobinae, O. mexiae, O. pachyglossum and O. subriparium) were recorded in Viçosa, Minas Gerais. They presented a tendency of one or two pollinanum removals and one pollinium insertion (single insertion), except O. appendiculatum. In this species, mainly, two pollinia of the same pollinarium were inserted per stigmatic chamber (double insertion), resulting exceptionally in 6-10 inserted pollinia in a flower, an unusual occurrence among the Asclepiadaceae. No association between removal and insertion was found, e.g., O. subriparium and O. banksii subsp. banksii had the highest pollinarium removal (1.78 and 1.45, respectively) and one of the lowest pollinium insertions (0.02 in both species), per flower. Oxypetalum mexiae showed the lowest pollinarium removal and pollinium insertion per flower (0.09 and 0.01, respectively) among the studied species and other Asclepiadaceae. Oxypetalum subriparium, O. banksii subsp. banksii and O, mexiae might be having reproductive limitations. Pollinarium removal and pollinium insertion per flower of the studied species varied from site to site, similarly to what was recorded for other Asclepiadaceae.5013743Bookman, S.S., The floral morphology of Asclepias speciosa (Asclepiadaceae) in relation to pollination and a clarification in terminology for the genus (1981) Amer. J. Bot., 68, pp. 675-679Bookman, S.S., Evidence for selective fruit production in Asclepias (1984) Evolution, 38, pp. 72-86Cabin, R.J., Ramstetter, J., Engel, R.E., Reproductive limitations of a locally rare Asclepias (1991) Rhodora, 93, pp. 1-10Fishbein, M., Venable, D.L., Diversity and temporal change in the effective pollinators of Asclepias tuberosa (1996) Ecology, 77, pp. 1061-1073Kunze, H., Structure and function in asclepiad pollination (1991) Plant Syst. Evolut., 176, pp. 227-253Kunze, H., Liede, S., Observations on pollination in Sarcostemma (Asclepiadaceae) (1991) Plant Syst. Evolut., 178, pp. 95-105Liede, S., Some observations on pollination in Mexican Asclepiadaceae (1994) Madroño, 41, pp. 266-276Liede, S., Whitehead, V., Studies in the pollination biology of Sarcostemma viminale R.Br. sensu lato (1991) South Afr. J. Bot., 57, pp. 115-122Lipow, S.R., Wyatt, R., Reproductive biology and breeding system of Gonolubus suberosus (Asclepiadaceae) (1998) J. Torrey Bot. Soc., 125, pp. 183-193Lynch, S.P., The floral ecology of Asclepias solanoana Woods (1977) Madroño, 24, pp. 159-177Macior, L.W., Insect adaptation and behavior in Asclepias pollination (1965) Bull. Torrey Bot. Club, 92, pp. 114-126Moore, R.J., Investigations on rubber-bearing plants. V. Notes on the flower biology and pod yield of Asclepias syriaca L (1947) Can. Field-natur., 61, pp. 40-46Ollerton, J., Liede, S., Pollination systems in the Asclepiadaceae: A survey and preliminary analysis (1997) Biol. J. Linn. Soc., 62, pp. 593-610Pleasants, J.M., Chaplin, S.J., Nectar production rates of Asclepias quadrifolia: Causes and consequences of individual variation (1983) Oecologia, 59, pp. 232-238Sage, T.L., Broyles, S.B., Wyatt, R., The relationship between the five stigmatic chambers and the two ovaries of milkweeds flowers: A three-dimensional assessment (1990) Isr. J. Bot., 39, pp. 187-196Sparrow, F.K., Pearson, N.L., Pollen compatibility in asclepias syriaca (1948) J. Agr. Res., 77, pp. 187-199Vieira, M.F., (1998) Biologia Reprodutiva de Espécies de Oxypetalum (Asclepiadaceae), na Região de Viçosa, MG, Sudeste Brasileiro, , PhD Thesis, Universidade Estadual de Campinas, Campinas, Brasil. 141 pVieira, M.F., Shepherd, G.J., Pollinators of oxypetalum (asclepiadaceae) in southeastern brazil (1999) Rev. Brasil. Biol., 59, pp. 693-704Vieira, M.F., Shepherd, G.J., Sistema reprodutivo de oxypetalum appendiculatum mart. e oxypetalum banksii subsp. banksii (asclepiadaceae) (1999) Acta Bot. Bras., 13, pp. 237-241Willson, M.F., Rathcke, B.J., Adaptive design of the floral display in asclepias syriaca l (1974) Amer. Midi Natur., 92, pp. 47-57Wyatt, R., Broyles, S.B., Ecology and evolution of reproduction in milkweeds (1994) Ann. Rev. Ecol. Syst., 25, pp. 423-44
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
Oxypetalum Banksii Subsp. Banksii: A Taxon Of Asclepiadaceae With An Extragynoecial Compitum
No full textThe floral morphology of seven Oxypetalum species and, in particular, the spatial relationship between the five stigmatic chambers and two separate ovaries of their flowers with respect to transmission of the pollen tube are studied. In all species, except O. banksii subsp. banksii, floral morphology is similar to that in other Asclepiadeae, and the flowers pollinated with one pollinium develop only one follicle, which means compitum absence. In O. banksii subsp. banksii flowers, the secretory interstaminal tissue lines the inner walls of the stigmatic chambers as in the other species studied, but it also reaches the upper part of the inner surface of the filament tube, where it surrounds the styles, an unprecedented feature for Asclepiadaceae. This tissue secretes nectar and mucilage; the latter acts as transmitting medium for the growth of pollen tubes from pollinia inserted and hydrated in stigmatic chambers ("hyperstigmas"). Mucilage also functions as an extragynoecial compitum: in flowers pollinated with one pollinium both carpels develop into a follicle.2333-4199206Baker, H.G., Baker, I., Floral nectar sugar constitutents in relation to pollinator type (1983) Handbook of Experimental Pollination Biology, pp. 117-141. , Jones C. E., Little R. J. (eds.). Van Nostrand Reinhold Company Inc., New YorkBookman, S.S., The floral morphology of Asclepias speciosa (Asclepiadaceae) in relation to pollination and a clarification in terminology for the genus (1981) Amer. J. Bot., 68, pp. 675-679Carr, S.G.M., Carr, D.J., The functional significance of syncarpy (1961) Phytomorphology, 11, pp. 249-256Christ, P., Schnepf, E., The nectaries of Cynanchum vincetoxicum (Asclepiadaceae) (1985) Israel J. Bot., 34, pp. 79-90Cronquist, A., (1988) The Evolution and Classification of Flowering Plants, , Allen Press, LawrenceEndress, M.E., Bruyns, P.V., A revised classification of the Apocynaceae s.l. (2000) Bot. Rev., 66, pp. 1-56Endress, P.K., Noncarpellary pollination and "hyperstigma" in an angiosperm (Tambourissa religiosa, Monimiaceae) (1979) Experientia, 35, p. 45Endress, P.K., Ontogeny, function and evolution of extreme floral construction in Monimiaceae (1980) Plant Syst. Evol., 134, pp. 79-120Endress, P.K., Syncarpy and alternative modes of escaping disadvantages of apocarpy in primitive angiosperms (1982) Taxon, 31, pp. 48-52Endress, P.K., (1994) Diversity and Evolutionary Biology of Tropical Flowers, , Cambridge University Press, CambridgeFallen, M.E., Floral structure in the Apocynaceae: Morphological, functional, and evolutionary aspects (1986) Bot. Jahrb. Syst., 106, pp. 245-286Fontella-Pereira, J., Schwarz, E.D.A., Estudos em Asclepiadaceae, XIX. Uma nova espécie de Gonolobus Mich e novas combinações em Oxypetalum R (1984) Br. Bol. Mus. Bot. Munic. Curitiba, (61), pp. 1-8Fontella-Pereira, J., Valente, M.D.C., De Alencastro, F.M.M.R., Contribuição ao estudo das Asclepiadaceae brasileiras, V. Estudo taxonômico e anatômico de Oxypetalum banksii Roem. et Schult (1971) Rodriguésia, (38), pp. 261-281Fontella-Pereira, J., Valente, M.D.C., Schwarz, E.D.A., Contribuição ao estudo das Asclepiadaceae brasileiras, XXI. Asclepiadaceae do município de Ouro Preto, Estado de Minas Gerais - Uma sinopse (1984) Bol. Mus. Bot. Kuhlmann, (2), pp. 63-127Galil, J., Zeroni, M., Nectar system of Asclepias curassavica (1965) Bot. Gaz., 126, pp. 144-148Gerlach, G., (1969) Botanische Mikrotechnik, Eine Einführung, , Georg Thieme, StuttgartHolm, R.W., The American species of Sarcostemma R. Br. (Asclepiadaceae) (1950) Ann. Missouri Bot. Gard., 37, pp. 477-560Johansen, D.A., (1940) Plant Microtechnique, , McGraw-Hill, New YorkKevan, P.G., Eisikowitch, D., Rathwell, B., The role of nectar in the germination of pollen in Asclepias syriaca L. (1989) Bot. Gaz., 150, pp. 266-270Kunze, H., Structure and function in asclepiad pollination (1991) Plant Syst. Evol., 176, pp. 227-253Kunze, H., Evolution of the translator in Periplocaceae and Asclepiadaceae (1993) Plant Syst. Evol., 185, pp. 99-122Kunze, H., Morphology of the stamen in the Asclepiadaceae and its systematic relevance (1996) Bot. Jahrb. Syst., 118, pp. 547-579Kunze, H., Corona and nectar system in Asclepiadinae (Asclepiadaceae) (1997) Flora, 192, pp. 175-183Kunze, H., Liede, S., Observations on pollination in Sarcostemma (Asclepiadaceae) (1991) Plant Syst. Evol., 178, pp. 95-105Liede, S., Anther differentiation in the Asclepiadaceae - Asclepiadeae: Form and function (1996) The Anther: Form, Function and Phylogeny, pp. 221-235. , D'Arcy W. G., Keating R. C. (eds.). Cambridge University Press, CambridgeLiede, S., Albers, F., Tribal disposition of genera in the Asclepiadaceae (1994) Taxon, 43, pp. 201-231Martin, F.W., Staining and observing pollen tubes in style by means of fluorescence (1959) Stain Techn., 34, pp. 125-128Morse, D.H., The twinning of follicles by common milkweed (Asclepias syriaca) (1993) Amer. Midl. Nat., 130, pp. 56-61Occhioni, P., Notas sôbre o gênero Oxypetalum - II (As espécies do Estado do Rio de Janeiro) (1953) Dusenia, 4, pp. 251-271Sage, T.L., Williams, E.G., Structure, ultrastructure, and histochemistry of the pollen tube pathway in the milkweed Asclepias exaltata L. (1995) Sex. Plant Repr., 8, pp. 257-265Sage, T.L., Broyles, S.B., Wyatt, R., The relationship between the five stigmatic chambers and two ovaries of milkweeds flowers: A three-dimensional assessment (1990) Israel J. Bot., 39, pp. 187-196Sennblad, B., Bremer, B., The familial and subfamilial relationships of Apocynaceae and Asclepiadaceae evaluated with rbcL data (1996) Plant Syst. Evol., 202, pp. 153-175Sparrow, F.K., Pearson, N.L., Pollen compatibility in Asclepias syriaca (1948) J. Agr. Res., 77, pp. 187-199Swarupanandan, K., Mangaly, J.K., Sonny, T.K., Kishorekumar, K., Chand Basha, S., The subfamilial and tribal classification of the family Asclepiadaceae (1996) Bot. J. Linn. Soc., 120, pp. 327-369Vieira, M.F., (1998) Biologia Reprodutiva de Espécies de Oxypetalum (Asclepiadaceae) na Região de Viçosa, MG, Sudeste Brasileiro, , Ph. D. Thesis, Campinas, São Paulo, BrazilVieira, M.F., Shepherd, G.J., Pollinators of Oxypetalum (Asclepiadaceae) in southeastern Brazil (1999) Rev. Brasil. Biol., 59, pp. 693-704Vieira, M.F., Shepherd, G.J., Sistema reprodutivo de Oxypetalum appendiculatum Mart. e Oxypetalum banksii Roem. & Schult. subsp. banksii (Asclepiadaceae) (1999) Acta Bot. Bras., 13, pp. 237-241Vieira, M.F., Shepherd, G.J., Removal and insertion of pollinia in flowers of Oxypetalum (Asclepiadaceae) in southeastern Brazil (2002) Rev. Biol. Trop., p. 50. , in pressWalker, D.B., Postgenital carpel fusion in Catharanthus roseus (Apocynaceae). IV. Significance of the fusion (1978) Amer. J. Bot., 65, pp. 119-121Woodson, R.E., The North American species of Asclepias L. (1954) Ann. Missouri Bot. Gard., 41, pp. 1-21
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
- …
