19 research outputs found

    BLOQUEIO DO ESCRITOR E OS DESAFIOS DA REDAÇÃO CIENTÍFICA

    Get PDF
    Diariamente, estudantes (graduação e pós-graduação) e pesquisadores jovens ou experientes estão diante do desafio da redação científica, incluindo a escrita de projetos de pesquisa, ensino, extensão e inovação, propostas para financiamento, relatórios técnico-científicos, trabalhos de conclusão de curso, dissertações, teses, artigos científicos, capítulos de livros, livros, resumos simples ou expandidos para eventos científicos, dentre outros. Entretanto, o fenômeno da tela branca ou bloqueio do escritor, também conhecido como “síndrome da página em branco” ou “Writer’s block”, pode impactar significativamente na produtividade e na qualidade das produções acadêmico-científicas, bem como na saúde mental do estudante e pesquisador. A síndrome da tela branca é um fenômeno temporário ou duradouro caracterizado por um bloqueio criativo no início ou progressão na escrita1. Diversos fatores podem contribuir para o bloqueio de escritor, tais como falta de formação e experiência teórica e/ou prática na área do conhecimento, pressões internas (perfeccionismo, autocobrança, medo do fracasso, falta de inspiração, saúde física e mental) e pressões externas (prazos rigorosos, expectativas de desempenho, processos avaliativos

    Antifungal susceptibility of the endophytic fungus Rhinocladiella similis (URM 7800) isolated from the Caatinga dry forest in Brazil

    Get PDF
    The present study reports a new occurrence of Rhinocladiella similis isolated as an endophytic fungus in the Caatinga dry tropical forest in Brazil and describes its antifungal susceptibility. The isolate R. similis URM 7800 was obtained from leaves of the medicinal plant Myracrodruon urundeuva. Its morphological characterization was performed on potato dextrose agar medium and molecular analysis using the ITS rDNA sequence. The antifungal susceptibility profile was defined using the Clinical and Laboratory Standards Institute (CLSI) protocol M38-A2. The colony of isolate URM 7800 showed slow growth, with an olivaceous-gray color and powdery mycelium; in microculture, it showed the typical features of R. similis. In the antifungal susceptibility test, isolate URM 7800 showed high minimal inhibitory concentration (MIC) values for amphotericin B (>16 μg/mL), voriconazole (16 μg/mL), terbinafine (>0.5 μg/mL), and caspofungin (>8 μg/mL), among other antifungal drugs. Pathogenic melanized fungi are frequently isolated in environments where humans may be exposed, and these data show that it is essential to know if these isolates possess antifungal resistance

    Pathogenicity of Beauveria bassiana and production of cuticle-degrading enzymes in the presence of Diatraea saccharalis cuticle

    Get PDF
    The sugarcane borer, Diatraea saccharalis, is one of the worst pests in Brazilian sugarcane crop, causing high levels of financial losses every year. Beauveria bassiana is an entomopathogenic fungus widely used in the biological control of several agricultural pests. The aims of this study were to: (1) evaluate the pathogenicity of B. bassiana strains against D. saccharalis (2) investigate the production of proteases and chitinase by B. bassiana in the presence of the cuticle of sugarcane borer; and, (3) evaluate the relation between the production of enzymes and pathogenicity of the strains. All isolates tested were pathogenic to D. saccharalis and the mortality ranged from 36 to 88%. The production of enzymes was higher in the medium containing cuticle, showing that the process is stimulated by specific components found in the cuticle of the host. Pr1 activity was higher than Pr2 and both were produced at 24 h. The highest production of chitinase was obtained at 96 h of culture for all strains tested. Levels of specific cuticle-degrading enzymes such as proteases correlated positively with specific virulence parameters. B. bassiana URM2915 showed promising features to be used in a biological control program of D. saccharalis.Key words: Biological control, sugarcane, subtilisin-like protease, trypsin-like protease, chitinase

    A Multigene phylogeny of Umbellidion revealed a novel lineage in Leotiomycetes

    No full text
    Novel sequences generated in this study were deposited in Genbank, (http://www.ncbi.nlm.nih.gov). Aligments file for Bayesian inference and Maximum likelihood, are deposited here.The dataset is based on LSU, ITS, SSU, RPB2 and TEF1.</p

    Genetic Diversity and Pathogenicity of <i>Botryosphaeriaceae</i> Species Associated with Symptomatic Citrus Plants in Europe

    No full text
    This study represents the first survey studying the occurrence, genetic diversity, and pathogenicity of Botryosphaeriaceae species associated with symptomatic citrus species in citrus-production areas in five European countries. Based on morphological features and phylogenetic analyses of internal transcribed spacer (ITS) of nuclear ribosomal DNA (nrDNA), translation elongation factor 1-alpha (TEF1) and β-tubulin (TUB2) genes, nine species were identified as belonging to the genera Diplodia, Dothiorella, Lasiodiplodia, and Neofusicoccum. Isolates of Neofusicoccum parvum and Diplodia pseudoseriata were the most frequently detected, while Dothiorella viticola had the widest distribution, occurring in four of the five countries sampled. Representative isolates of the nine Botryosphaeriaceae species used in the pathogenicity tests caused similar symptoms to those observed in nature. Isolates assayed were all re-isolated, thereby fulfilling Koch’s postulates. Isolates of Diplodia pseudoseriata and Diplodia olivarum are recorded for the first time on citrus and all species found in our study, except N. parvum, are reported for the first time on citrus in Europe

    Brazilian tropical dry forest (Caatinga) in the spotlight: An overview of species of aspergillus, penicillium and talaromyces (eurotiales) and the description of p. vascosobrinhous sp. nov.

    No full text
    A literature-based checklist of species of Aspergillus, Penicillium, and Talaromyces recorded in the Brazilian tropical dry forest (Caatinga), the largest tropical dry forest region in South America, is provided. A total of 130 species (60 Aspergillus, 57 Penicillium, and 13 Talaromyces) are reported. Soil was the most common substrate, with 122 species records. Various reported species are well known in biotechnological processes. This checklist reflects the limited knowledge of fungal species in tropical dry environments. These data provide a good starting point for biogeographical studies on species of Aspergillus, Penicillium, and Talaromyces in dry environments worldwide. In addition, the new species Penicillium vascosobrinhous is introduced, an endophytic fungus isolated from cactus of the Caatinga forest in Brazil

    Insights into the Bioprospecting of the Endophytic Fungi of the Medicinal Plant Palicourea rigida Kunth (Rubiaceae): Detailed Biological Activities

    No full text
    A multitude of plants from the Brazilian savanna are known for their medicinal properties. Many plants contain endophytic fungi, which lead to the production of bioactive compounds by both the fungi and their hosts. This study investigated the bioprospecting of endophytic fungi recovered from the leaves of Palicourea rigida, a native medicinal plant of the Brazilian savanna. Four fungal taxa (Colletotrichum sp. SXS649, Pestalotiopsis sp. SXS650, the order Botryosphaeriales SXS651, and Diaporthe sp. SXS652) were recovered. The phenolic, flavonoid, extracellular degrading enzymes (amylase, cellulase, protease, and tannase) and antioxidant activity of these taxa were determined. Evaluation of the antimicrobial activity showed that the Botryosphaeriales SXS651 extract displays a minimum inhibitory concentration (MIC) of 23.20 mg mL−1 against Staphylococcus epidermidis and Pseudomonas aeruginosa, and the Diaporthe sp. SXS652 extract exhibited an MIC of 27.00 mg mL−1 against Escherichia coli. The Colletotrichum sp. SXS649 isolate inhibited tumors in potato discs by 69% at a concentration of 9.70 mg mL−1. All isolates had potential bioremediation criteria against soil contaminated with soybean oil, as proved by a high percentage of germination of Lactuca sativa and a reduction in phytotoxicity. Furthermore, the taxa under investigation demonstrated antagonistic action to phytopathogenic fungi, namely, Aspergillus niger, Inonotus rickii, Pestalotiopsis mangiferae, and Coniophora puteana, with an inhibition range between 34.2% and 76.9%. The preliminary toxicity assessment showed that all isolates possessed an LC50 of less than 100 mg mL−1 to the microcrustacean Artemia salina. These results indicate that the endophytic fungi of the Brazilian savanna are promising candidates for biotechnological and industrial applications and, in agricultural applications, for the biological control of phytopathogenic fungi

    Fungal endophyte diversity in the leaves of the medicinal plant Myracrodruon urundeuva in a Brazilian dry tropical forest and their capacity to produce L-asparaginase

    No full text
    ABSTRACT We studied the fungal endophyte community of the leaves of Myracrodruon urundeuva in Brazil along with their potential to produce L-asparaginase. In total, 187 endophytes were isolated. The colonization rate of leaf fragments from caatinga (10.41 %) was lower than those from brejo de altitude (39.58 %). Sequences of ITS rDNA from all endophytes revealed relationships with Ascomycota (Botryosphaeriales, Chaetothyriales, Diaporthales, Eurotiales, Glomerellales, Hypocreales, and Pleosporales) and Basidiomycota (Polyporales). The most frequent endophytes were members of the genus Diaporthe. Talaromyces was an indicator genus for caatinga while Phyllosticta, Diaporthe, and Colletotrichum were for brejo de altitude. The composition of endophytic fungi in caatinga and brejo de altitude differed significantly, its richness and diversity (H' = 3.41) being significantly higher in brejo de altitude. Diaporthe sp. URM 7793 was the best producer of L-asparaginase (2.41 U/g), followed by Diaporthe sp. URM 7779 (2.00 U/g), Talaromyces sp. URM 7785 (1.91 U/g), and Diaporthe sp. URM 7792 (1.47 U/g). The composition of endophytic fungi assemblages is strongly influenced by the type of ecosystem. In its natural habitat, M. urundeuva harbors an important diversity of endophytes, which could be used to produce L-asparaginase

    Mycological Diversity Description I

    No full text
    Here, Quambalaria fabacearum and Neopestalotiopsis brasiliensis are introduced as new species from Brazil, isolated as endophyte from Mimosa tenuiflora and causing post-harvest rot disease on fruits of Psidium guajava, respectively. Diaporthe inconspicua is emended to include a more detailed morphological description. Neopestalotiopsis egyptiaca is reported as new to the Americas and as causing post-harvest rot disease on fruits of Psidium guajava, while Umbelopsis isabellina is reported as endophyte
    corecore