302 research outputs found

    Parasites component community in wild population of Pterophyllum scalare Schultze, 1823 and Mesonauta acora Castelnau, 1855, cichlids from the Brazilian Amazon.

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    The aim of the present study was to compare the component parasite communities of the Pterophyllum scalare and Mesonauta acoracichlids in the Amazon River system in northern Brazil. From September to December 2012, 42 specimens of P. scalareand 38 specimens of M. acorawere captured using hand nets and gillnets in the Igarape Fortaleza basin, a tributary of the Amazon River in the state of Amapa. Of the P. scalarespecimens examined, 97.6% were parasitized by Ichthyophthirius multifiliis, Tripartiellasp., Trichodina nobilis, Gussevia spiralocirra, Posthodiplostomum sp., Capillaria pterophylli, Ichthyouris sp. and Gorytocephalus spectabilis. Similarly, all specimens of M. acorawere parasitized by I. multifiliis, Tripartiellasp,T. nobilis, Sciadicleithrum joanae, Posthodiplostomum sp., Pseudoproleptus sp., Ichthyouris sp. and G. spectabilis. However, for both hosts the dominance was of I. multifiliisand with an overdispersion of parasites. Parasite communities of P. scalare and M. acorawere similar and only Pseudoproleptussp. and Posthodiplostomum sp. were larvae. Brillouin diversity, parasite species richness and evenness were higher forM. acorathan for P. scalare, which presented a negative correlation of parasite abundance with body size. Both cichlid species had parasite communities characterized by low diversity and low species richness, with a predominance of ectoparasite species and greatest richness of helminth species, with a low abundance of endoparasites. This was the first study on the parasite diversity in wild P. scalareandM. acora

    Insetos associados a macrófitas aquáticas na ressaca da Lagoa do Índios em Macapá, AP.

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    As ressacas são ecossistemas complexos que sofrem efeitos de ação das marés e pluviosidade.Resumo 1504-2

    Self-gravitating domain walls and the thin-wall limit

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    We analyse the distributional thin wall limit of self gravitating scalar field configurations representing thick domain wall geometries. We show that thick wall solutions can be generated by appropiate scaling of the thin wall ones, and obtain an exact solution for a domain wall that interpolates between AdS_4 asymptotic vacua and has a well-defined thin wall limit.Solutions representing scalar field configurations obtained via the same scaling but that do not have a thin wall limit are also presented.Comment: 10 pages, revte

    Identification of ‘Candidatus Phytoplasma’ species in “huanglongbing” infected citrus orchards in the Caribbean

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    “Huanglongbing” (HLB) is one of the most devastating diseases of citrus orchards worldwide. Samples from 183 citrus plants of different cultivars and rootstock/cultivar combinations, showing HLB symptoms in three Caribbean countries (Cuba, Jamaica, and Guadeloupe-France), were collected to verify the possible co-infection of ‘Candidatus Phytoplasma’ and ‘Candidatus Liberibacter’ species. The 64% of the samples resulted positive to the ‘Ca. L. asiaticus’ and the 27% to diverse ‘Ca. Phytoplasma’-related species, moreover about the 14% of the samples infected with ‘Ca. Liberibacter’ were also found positive to phytoplasmas, indicating the presence of mixed infection especially in the orchards located in Cuba. Moreover, in one of the samples from Jamaica mixed phytoplasma infection was detected. Moreover the detection of only phytoplasmas in 11 symptomatic citrus samples collected from Cuba and Guadeloupe without ‘Ca. Liberibacter’ detection, confirmed that the symptomatology cannot be the sole criterium to discriminate between the presence of the two pathogens, and molecular detection is necessary to identify single or mixed infections. Diaphorina citri insects collected from Cuba and Guadeloupe resulted infected with ‘Ca. L. asiaticus’ confirming its active role in the dissemination of the pathogen. Only one insect of the Cicadidae family, collected in Guadeloupe, was found positive for phytoplasma presence. Considering that the phytoplasmas belonging to some ‘Candidatus species’ were detected in the three countries in different citrus varieties, a relevant role as phytoplasma reservoir can be attribute to citrus orchards
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