1,721,188 research outputs found
Cytogenetic Markers As Diagnoses In The Identification Of The Hybrid Between Piau&u (leporinus Macrocephalus) And Piapara (leporinus Elongatus)
No full textThe genetic monitoring of interspecific hybrids involves the application of methodologies able to provide an easy and indubitable genetic characterization of both parental and hybrid individuals. In the present work, cytogenetic techniques were used to identify a hybrid lineage of "Piaupara" in order to caracterize them in relation to the parental species, Leporinus macrocephalus (piauçu) and L. elongatus (piapara). The cytogenetic analysis revealed that L. macrocephalus presented 2n = 54 chromosomes and a nucleolar organizer regions (NOR) at the telomere of the long arm of the submetacentric chromosome pair 2. Analysis of constitutive heterochromatin (C-banding) revealed a conspicuous block at the pericentromeric region on the long arm of a submetacentric chromosome pair. L. elongatus presented the same diploid number, 2n = 54, and a karyotypic formula similar to that of L. macrocephalus. The NORs were also at the telomere of the long arm of the submetacentric pair 2, which was morphologically different from that of L. macrocephalus. Heterochromatic blocks were observed at both telomeres of a submetacentric chromosome pair. The hybrid "Piaupara" presented the same diploid number (2n = 54) and karyotypic formula as the parental species and there were no visible differences between parental and hybrid individuals. Differently from the Giemsa staining, NOR- and C-banding analysis showed marked differences which allowed the identification of the hybrids by the different morphology and/or size of the chromosomes carrying the NORs and patterns of heterochromatin distribution in their chromosomes. Such genetic studies are important for fish culture since they can provide tools for monitoring natural and artificial hybridization. They are also useful in biological conservation programmes and in the proper management of natural and reared fish stocks. Copyright © 2008, Sociedade Brasileira de Genética.311 SUPPL. 1195202Almeida-Toledo LF, Foresti F, Toledo-Filho SA, Bernardino G, Ferrari VA and Alcantara RCG (1987) Cytogenetic studies in C. mitrei, C. macropomum and their interspecific hybrid. In: Tiews K (ed) Selection, Hybridization and Genetic Engineering in Aquaculture. Berlin Heenemann Verlagsgesellshaft mb II v. 1, pp 189-195Almeida-Toledo, L.F., Foresti, F., Ramos, S.M., Ormanezi, R., Carosfeld, V.J.S., Toledo-Filho, S.A., Estudos citogenéticos de híbridos entre fêmeas de pacu (Piaractus mesopotamicus) e machos de tambaqui (Colossoma macropomum) (1988) B Tec CEPTA, 1, pp. 1-17Brinn, M.N.A., Porto, J.I.R., Feldberg, E., Karyological evidence for interspecific hybridization between Cichla monoculus and C. temensis (Perciformes, Cichlidae) in the Amazon (2004) Hereditas, 141, pp. 252-257Durica, D.S., Krider, H.M., Studies on the ribosomal RNA cistrons in Drosophila hybrids. II. Heterochromatic regions mediating nucleolar dominance (1978) Genetics, 89, pp. 37-64Foresti, F., Almeida-Toledo, L.F., Toledo-Filho, S.A., Polymorphic nature of nucleolus organizer regions in fishes (1981) Cytogenet Cell Genet, 31, pp. 137-144Galetti Jr, P.M., Foresti, F., Evolution of the ZZ/ZW system in Leporinus (Pisces, Anostomidae) (1986) Cytogenet Cell Genet, 43, pp. 43-46Galetti Jr, P.M., Foresti, F., Two new cases of ZZ/ZW heterogamety in Leporinus (Anostomidae, Characiformes) and their relationships in the phylogeny of the group (1987) Braz J Genet, 10, pp. 135-140Galetti Jr, P.M., Foresti, F., Bertollo, L.A.C., Moreira-Filho, O., Karyotypic similarity in three genera (Leporinus, Leporellus and Schizodon) of the family Anostomidae (Pisces, Teleostei) (1981) Braz J Genet, 4, pp. 11-15Galetti Jr, P.M., Foresti, F., Bertollo, L.A.C., Moreira-Filho, O., Heteromorphic sex chromosomes in three species of the genus Leporinus (Pisces, Anostomidae) (1981) Cytogenet Cell Genet, 29, pp. 138-142Galetti Jr, P.M., Foresti, F., Bertollo, L.A.C., Moreira-Filho, O., Characterization of eight species of Anostomidae (Cypriniformes) fish on the basis of the nucleolar organizing region (1984) Caryologia, 37, pp. 401-406Galetti Jr, P.M., Cesar, A.C.G., Venere, P.C., Heterochromatin and NORs variability in Leporinus fish (Anostomidae, Characiformes) (1991) Caryologia, 44, pp. 287-292Galetti Jr, P.M., Mestriner, C.A., Venere, P.C., Foresti, F., Heterochromatin and karyotype reorganization in fish of the family Anostomidae (Characiformes) (1991) Cytogenet Cell Genet, 56, pp. 116-121Galetti Jr, P.M., Lima, N.R.W., Venere, P.C., A monophyletic ZW chromosome system in Leporinus (Anostomidae, Characiformes) (1995) Cytologia, 60, pp. 375-382Garavello, J.C., Britski, H.A., A Family Anostomidae (Headstanders) (2003) Check list of the freshwater fishes of South and Central America, pp. 71-84. , Reis RE, Kullander SO and Ferraris Jr CJ eds, EDIPUCRS, Porto Alegre, ppGéry J (1977) Characoids of the World. T.F.H. Publications, Neptune City, 672 ppGold, J.R., Li, Y., Schmidt, T.R., Tave, D., Nucleolar dominance in interspecific hybrids of cyprinid fishes (1991) Cytobios, 65, pp. 139-147Howell, W.M., Visualization of ribosomal gene activity: Silver stains proteins associated with rRNA transcribed from oocyte chromosomes (1977) Chromosoma, 62, pp. 361-367Howell, W.M., Black, D.A., Controlled silver-staining of nucleolus organizer regions with a protective colloidal developer: A 1-step method (1980) Experientia, 36, pp. 1014-1015Hubbs, C.L., Hybridization between fish species in nature (1955) Syst Zool, 4, pp. 1-20Jordan, G., At the heart of the nucleolus (1987) Nature, 329, pp. 489-490Koehler, M.R., Dehm, D., Guttenbach, M., Nanda, I., Haaf, T., Molina, W.F., Galetti Jr, P.M., Schmid, M., Cytogenetics of the genus Leporinus (Pisces, Anostomidae). 1. Karyotype analysis, heterochromatin distribution and sex chromosomes (1997) Chromosome Res, 5, pp. 12-22Kossowski, Q., Bracamonte, N.O., Velasco, J.Q., Cariotipo del hibrido de Colossoma macropomum (hembra) (Cuvier) 1818 Mylossoma duriventris (macho) (Cuvier) 1818 y sus progenitores (1983) Acta Científica Venezolana, 34, pp. 173-175Levan, A., Fredga, K., Sandbreg, A.A., Nomenclature for centromeric position on chromosomes (1964) Hereditas, 52, pp. 201-220Martini, G., O'Dell, M., Flavell, R.B., Partial inactivation of wheat nucleolus organizers by the nucleolus organizer from Aegilops umbellulata (1982) Chromosoma, 84, pp. 687-700Molina, W.F., Galetti Jr, P.M., Early replication banding in Leporinus species (Osteichthyes, Characiformes) bearing differentiated sex chromosomes (ZW) (2006) Genetica, 1, pp. 1-15Molina, W.F., Schmid, M., Galetti Jr, P.M., Heterochromatin and sex chromosomes in the Neotropical fish genus Leporinus (Characiformes, Anostomidae) (1998) Cytobios, 94, pp. 141-149Porto-Foresti, F., Foresti, F., Genética e biotecnologia em piscicultura: Usos na produção, manejo e conservação dos estoques de peixes (2004) Tópicos especiais em piscicultura de água doce tropical intensiva. TecArt, pp. 195-215. , São Paulo, ppReeder, R.H., Roan, J.G., The mechanism of nucleolar dominance in Xenopus hybrids (1984) Cell, 38, pp. 39-44Ryman, N., Utter, F.M., (1987) Population Genetics & Fishery Management, , University of Washington Press, Seattle, 420 ppSumner, A.T., A simple technique for demonstrating centromeric heterochromatin (1972) Exp Cell Res, 75, pp. 304-306Toledo-Filho, S.A., Almeida-Toledo, L.F., Foresti, F., Calcagnotto, D., Fonteles-Santos, S.B.A., Bernardino, G., (1998) Cadernos de Ictiogenética 4: Programas Genéticos de Seleção, Hibridação e Endocruzamento Aplicados à Piscicultura, , Universidade de São Paulo, São Paulo, 56 ppVari, R.P., Phylogenetic relationships of the families Curimatidae, Prochilodontidae, Anostomidae and Chilodontidae (Pisces, Characiformes) (1983) Smithsonian Contributions to Zoology, 378, pp. 1-6
L’immagine della destinazione turistica: il Trentino Alto Adige
No full textL’importanza dell’immagine della destinazione turistica è universalmente riconosciuta e sempre più crescente è l’attenzione da parte dei ricercatori del settore in quanto non solo permette di differenziare tra loro le località ma è parte integrante ed influente del processo di decisone e scelta della vacanza stessa.
La ricerca, che ha come obiettivo l’analisi dei messaggi pubblicitari del Trentino Alto Adige apparsi negli ultimi dieci anni, si configura come un’esplorazione del mondo pubblicitario trentino con l’intento di rinvenire informazioni relative alle scelte di immagine promosse dalla regione. Modello teorico di riferimento è la teoria «push-pull» del costrutto di immagine primaria elaborata da Chon (1989, 1991).
Sono stati analizzati i messaggi pubblicitari del Trentino pubblicati dal 1995 al 2004, per un totale di 63 messaggi. I messaggi pubblicitari sono stati esaminati mediante un’analisi del contenuto, effettuata con l’ausilio del software Atlas.ti. L’immagine viene maggiormente creata da elementi pull (la frequenza totale dei codici degli elementi pull è 433). Il Trentino rappresenta la «montanità», intesa come un ambiente naturale, unico, sorprendente, ricco di valori etici e spirituali, di grande qualità, dotato di strutture ricettive più che soddisfacenti. Il Trentino è presentato come terra dell’intrattenimento e dello svago, con l’offerta di eventi che coinvolgono il turista offrendo la possibilità di divertimento, di gusto e di arricchimento conoscitivo. I fattori push (la frequenza totale dei codici degli elementi push è 314) su cui punta maggiormente la pubblicità e che vanno a completare l’immagine sono i bisogni fisiologici e quelli di autorealizzazione.
Nei dieci anni presi in considerazione la pubblicità ha mantenuto invariato il tono dei suoi messaggi (ovviamente sono cambiati gli slogan e il tipo di immagine) che risulta amichevole, rassicurante, emotivo e coerente con l’offerta. La comunicazione contribuisce al rafforzamento dell’immagine e a consolidare la forte identità del territorio
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
Karyotype And Nucleolus Organizer Regions Of Ophisternon Aenigmaticum (teleostei: Synbranchiformes: Synbranchidae) From Venezuela (in English)
No full textThe first cytogenetic analysis by conventional Giemsa staining, silver nitrate impregnation of nucleolus organizer regions (Ag-NOR), and fluorescence in situ hybridization (FISH) carried out on Ophisternon aenigmaticum from Margarita Island, Venezuela, is reported. Two cytotypes were found: cytotype C1, 2n=46, composed of 6 medium size metacentrics, 2 subtelocentrics and 38 acrocentrics; and cytotype C2, 2n=45, composed of one large metacentric plus 5 medium size metacentrics, 1 subtelocentric and 38 acrocentric chromosomes. In cytotype C1, major ribosomal DNA (rDNA) cistrons are located in the terminal position of the short arms of the first metacentric pair as determined by Ag-NORs and FISH with the 18S rDNA probe. In cytotype C2, silver staining revealed only one positive signal in a single chromosome of the pair 1 whereas FISH with the 18S rDNA probe hybridized in two different chromosomes: One coincident with the Ag-NOR (pair 1) and other in one acrocentric chromosome, suggesting the occurrence of a peri-centric inversion. In both cytotypes, FISH with 5S rDNA probe produced hybridization signals in subtelomeric position of the short arm of the chromosome pair No. 3. Chromosome evolution in Synbranchidae is discussed.363229233Favorito-Amorim, S.A., (1998) Relações Filogenéticas da Orden Synbranchiformes e Revisão Sistemática da Familia Synbranchidae, p. 217. , Thesis. Instituto de Biociências, Universidade de São Paulo, BrazilFavorito, S.E., Zanata, A.M., Assumpção, M.I., A new Synbranchus (Teleostei: Synbranchiformes: Synbranchidae) from Ilha de Marajó, Pará, Brazil, with notes on its reproductive biology and larval development (2005) Neotrop. Ichthyol., 3, pp. 319-328Foresti, F., Oliveira, C., Tien, O.S., Cytogenetic studies of the genus Synbranchus (Pisces, Synbranchiformes, Synbranchidae) (1992) Naturalia, 17, pp. 129-138Foresti, F., Oliveira, C., Foresti De Almeida-Toledo, L., A method for chromosome preparations from large fish specimens using in vitro short-term treatment with colchicine (1993) Experientia, 49 (9), pp. 810-813Froese, R., Pauly, D., Fishbase, 2009. , www.fishbase.org, version (Cons. 10/2009)Howell, W.M., Visualization of ribosomal gene activity: silver proteins associated with rRNA transcribed from oocyte chromosomes (1977) Chromosoma, 62 (4), pp. 361-367. , DOI 10.1007/BF00327034Howell, W.M., Black, D.A., Location of the nucleolus organizer regions on the sex chromosomes of the banded killifish, Fundulus diaphanous (1979) Copeia, 3, pp. 544-546Howell, W.M., Black, D.A., Controlled silver staining of nucleolus organizer regions with a protective colloidal developer: A 1-step method (1980) Experientia, 3, pp. 1014-1015Kullander, S.O., Family synbranchidae (Swamp-eels) (2003) Check List of the Freshwater Fishes of South America, pp. 594-595. , Reis RE, Kullander SO, Ferraris CJ (Eds.), Edipucrs. Porto Alegre, BrazilLevan, A., Fredga, A., Sandburg, A., Nomenclature for centromeric position on chromosomes (1964) Hereditas, 52, pp. 201-220Long, E.O., David, I.D., Repeated genes in eukaryotes (1980) Annu. Rev. Biochem., 49, pp. 727-764Melillo, I.F.M., Foresti, F., Oliveira, C., Additional cytogenetic studies on local populations of Synbranchus marmoratus (Pisces, Synbranchiformes, Synbranchidae) (1996) Naturalia, 21, pp. 201-208Messias, L.H.V., Ferreira, D.C., Wasko, A.P., Oliveira, C., Foresti, F., Martins, C., 5S rDNA organization in the fish Synbrachus marmoratus (Synbrachidae, Synbranchiformes) (2003) Hereditas, 139 (3), pp. 228-231. , DOI 10.1111/j.1601-5223.2003.01759.xNelson, J.S., (2006) Fishes of the World, p. 601. , Wiley. New York, USAPendas, A.M., Moran, P., Freije, J.P., Garcia-Vazquez, E., Chromosomal mapping and nucleotide sequence of two tandem repeats of Atlantic salmon 5S rDNA (1994) Cytogenetics and Cell Genetics, 67 (1), pp. 31-36Pinkel, D., Straume, T., Gray, J.W., Cytogenetic analysis using quantitative, high-sensitivity, fluorescence hybridization (1986) Proceedings of the National Academy of Sciences of the United States of America, 83 (9), pp. 2934-2938Porto-Foresti, F., Oliveira, C., Gomes, E.A., Tabata, Y.A., Rigolino, M.G., Foresti, F., A lethal effect associated with polymorphism of the NOR-bearing chromosomes in rainbow trout (Oncorhynchus mykiss) (2004) Genetics and Molecular Biology, 27 (1), pp. 51-54Sambrook, J., Russell, D.W., (2001) Molecular Cloning: A Laboratory Manual, p. 2344. , Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, USASanchez, S., Fenocchio, A.S., Karyotypic analysis in three populations of the South-American eel like fish Synbranchus marmotatus (1996) Caryologia, 49 (1), pp. 65-71Torres, R.A., Roper, J.J., Foresti, F., Oliveira, C., Surprising genomic diversity in the Neotropical Synbranchus marmoratus (Teleostei, Synbranchidae): How many species? (2005) Neotrop. Ichthyol., 3, pp. 277-28
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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