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Search Results: 1 - 10 of 93 matches for " Pavanelli "
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A Calabi-Yau threefold with Brauer group (Z/8Z)^2
Mark Gross,Simone Pavanelli
Mathematics , 2005,
Abstract: We calculate the Brauer group of a certain Calabi-Yau threefold discovered by Mark Gross and Sorin Popescu, which is a small resolution of a complete intersection of type (2,2,2,2) with 64 ordinary double points. We find the Brauer group is (Z/8Z)^2, which is the largest known example of a Brauer group of a Calabi-Yau threefold.
A new Tatia (Ostariophysi: Siluriformes: Auchenipteridae) from the rio Igua?u basin, Paraná State, Brazil
Pavanelli, Carla Simone;Bifi, Alessandro Gasparetto;
Neotropical Ichthyology , 2009, DOI: 10.1590/S1679-62252009000200010
Abstract: a new species of tatia is described from the lower rio igua?u basin, paraná state, brazil. the new species is distinguishable from congeners by having large, irregular pale blotches over dark brown base coloration, absent longitudinal stripe, caudal fin with round to striate dark brown spots over light base in adults or entirely dark in juveniles, and by having a long humeral process. sexual dimorphism of the new species is marked by differences among genital and urinary apertures, size proportions between upper and lower lobe of caudal fin, and size, width and presence of antrorse and retrorse spines on anal-fin rays.
A redescription of Astyanax gymnodontus (Eigenmann, 1911), new combination, a polymorphic characid fish from the rio Igua?u basin, Brazil
Pavanelli, Carla Simone;Oliveira, Carlos Alexandre Miranda;
Neotropical Ichthyology , 2009, DOI: 10.1590/S1679-62252009000400003
Abstract: astyanax gymnodontus (eigenmann, 1911), new combination, a polymorphic characid fish endemic to the rio igua?u basin in southern brazil, is redescribed. the species was originally described as belonging to the monotypic genus psalidodon, distinguished from astyanax by the possession of a single series of teeth on the premaxilla (vs. two series), by the presence of relatively compressed teeth on the premaxillary and dentary bones (vs. relatively bulky teeth), and by the absence of lips (vs. lips present). examination of a large number of specimens from the rio igua?u basin that present dental and lip features that were intermediate between psalidodon and astyanax indicated that specimens attributed to psalidodon show extreme characters observed within a polymorphic astyanax species. accordingly, the genus psalidodon is synonymized under astyanax. specimens of "astyanax sp. f" morphotype from the rio igua?u basin belong to the species astyanax gymnodontus and display a regular tooth arrangement and morphology, and their lip development is similar to that of other astyanax species.
Cria??o de conhecimento na indústria de alta tecnologia: estudo de casos em projetos de diferentes graus de inova??o
Stefanovitz, Juliano Pavanelli;Nagano, Marcelo Seido;
Gest?o & Produ??o , 2009, DOI: 10.1590/S0104-530X2009000200008
Abstract: the main objective of this research is to provide a characterization of the knowledge creation process involved in high-tech product development projects with different innovations degrees. as theoretical contribution, this work joins some of the most important approaches of this process in a framework that organizes concepts in four main dimensions. a study of cases done in a company that develops high-tech systems for the industrial automation market is presented investigating three projects in the r&d division of the company. a comparative analysis of the knowledge creation processes observed in each of these projects is made. the main result is the identification of creative process characteristics that are influenced by the innovation degree.
Spasskyellina mandi n. sp. (Proteocephalidea: Monticelliidae), parasite of Pimelodus ornatus Kner, 1857 (Pisces: Pimelodidae) of the Paraná River, Paraná, Brazil
Pavanelli, Gilberto C;Takemoto, Ricardo M;
Memórias do Instituto Oswaldo Cruz , 1996, DOI: 10.1590/S0074-02761996000600013
Abstract: spasskyellina mandi n. sp. (proteocephalidea: monticelliidae) is described from the siluriform fish pimelodus ornatus kner, 1857, caught in the paraná river, paraná, brazil. the new species differs from other species of the same genus mainly by a fewer number of testes and by a larger osmoregulatory canal. this is the second species of proteocephalidean cestode collected in p. ornatus.
New species of Proteocephalus (Cestoda - Proteocephalidae) parasitic in fishes from the Paraná River, Paraná, Brazil
Pavanelli, Gilberto C.;Takemoto, Ricardo M.;
Memórias do Instituto Oswaldo Cruz , 1995, DOI: 10.1590/S0074-02761995000500009
Abstract: two species of the genus proteocephalus (cestoda: proteocephalidae) were collected in fishes from the paraná river. proteocephalus vazzolerae n. sp. from piaractus mesopotamicus and proteocephalus chubbi, n. sp. from gymnotus carapo are new species, and are described and illustrated. proteocephalus vazzolerae n. sp. is characterized mainly by the number of testes and the development of vitellaria. proteocephalus chubbi n. sp. can be differentiated from its congeners by a combination of characters which include, number of testes, number of proglottids, strobila length, scolex shape and disposition of vitellaria. this is the first record of proteocephalidean in p. mesopotamicus and g. carapo.
Megathylacus travassosi sp. n. and Nomimoscolex sudobim Woodland, 1935 (Cestoda - Proteocephalidea) parasites of Pseudoplatystoma corruscans (Agassiz, 1829) (Siluriformes - Pimelodidae) from the Itaipu reservoir and Parana River, Parana State, Brazil
Pavanelli, Gilberto Cezar;Rego, Amilcar Arandas;
Memórias do Instituto Oswaldo Cruz , 1992, DOI: 10.1590/S0074-02761992000500036
Abstract: it is described megathylacus travassosi sp. n., parasite of pseudoplatystoma corrusccans (agassiz,1829), a pimelodid fish caught in itaipu reservoir and paraná river, brazil. nomimoscolex sudobim woodland, 1935 is redescribed and for the first time referred parasitising p. corruscans. the list of proteocephalid cestodes of genus pseudoplatystoma bleeker, 1862, with its geographic distribution is given.
Temporal and spatial distribution of the ichthyofauna in two streams of the upper Rio Paraná basin
Pavanelli, Carla Simone;Caramaschi, érica Pellegrini;
Brazilian Archives of Biology and Technology , 2003, DOI: 10.1590/S1516-89132003000200019
Abstract: the temporal and spatial distribution of the ichthyofauna was assessed in two streams, caracu and s?o pedro, affluents of the rio paraná, from march 1991 through february 1992. samples were taken along the streams, using sieves (three sites on the caracu and two on the s?o pedro), and gill nets (two sites on the s?o pedro). a total of 6,664 specimens belonging to 71 species were captured. cpe was calculated for each fishing gear. the data for cumulative frequency indicated that only the mouths of streams did not reach an asymptote. constancy analysis showed that occasional and accessory species predominated. the spectrum of spatial diversity indicated that diversity increased toward the mouth of streams and temporal diversity increased in the high water season. the results of correspondence analysis for sieved fishes and s?rensen similarity for netted ones showed that the sites located at the same position on the streams were more similar than between adjacent sites in the same stream.
Ecology of endoparasites of the fluvial stingray Potamotrygon falkneri (Chondrichthyes: Potamotrygonidae) from the upper Paraná River floodplain, Brazil
Lacerda, ACF.;Takemoto, RM.;Pavanelli, GC.;
Brazilian Journal of Biology , 2009, DOI: 10.1590/S1519-69842009000200009
Abstract: the present study investigated the ecological relationships between endoparasites and the host potamotrygon falkneri from the upper paraná river by using as indicators the host's relative condition factor (kn), sex and hepatosomatic relation (hsr). forty-seven specimens of p. falkneri were analyzed between march 2005 and september 2006. statistical analysis showed that the kn was positively correlated with the abundance of acanthobothrium regoi and rhinebothrium paratrygoni; only the abundance of a. regoi was positively correlated to the hsr, whereas r. paratrygoni did not present correlation and there was no influence of the host's sex on the abundance and prevalence of parasites. this is the first study concerning the ecology of parasites of potamotrygonids.
Aspects of the ecology of proteocephalid cestodes parasites of Sorubim lima (Pimelodidae) of the upper Paraná River, Brazil: I. Structure and influence of host's size and sex
Revista Brasileira de Biologia , 2000, DOI: 10.1590/S0034-71082000000400006
Abstract: between march 1992 and february 1996, 107 specimens of sorubim lima were collected in the floodplain of the upper paraná river. ninety-five (88.78%) specimens were parasitized with at least one species of proteocephalid cestodes. 7,573 specimens of four different species were collected (average intensity 79.71 parasites/host): paramonticellia itaipuensis pavanelli & rego, 1991; nupelia portoriquensis pavanelli & rego, 1991; spatulifer maringaensis pavanelli & rego, 1989 and spasskyellina spinulifera woodland, 1935. s. maringaensis was the most prevalent and abundant. there were three dominant species p. itaipuensis, s. maringaensis and n. portoriquensis) and one co-dominant species (s. spinulifera). the three environments (lotic, semilotic and lentic) in which collection was undertaken showed high similarity with regard to parasitic fauna. a high simpson index value (0.359) indicates dominance tendency among species of parasites. concerning s. maringaensis significant positive correlation was observed between parasite intensity and standard length of hosts. no species had negative correlation. with regard to s. maringaensis and n. portoriquensis prevalence was positive and significantly correlated with standard length of hosts. no species had negative correlation. in the case of s. maringaensis and n. portoriquensis influence of host's sex was noted on parasite intensity. there was no sex influence on parasite prevalence in any species.
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