549 research outputs found

    Qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem

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    The objective of this work was to evaluate the physiological quality of osmoprimed eggplant seeds subjected to drying. Eggplant seeds of the cultivar Embu, primed in aerated KNO3 (‑0.8 MPa) solution, at 25ºC, for 48 hours, were used. The seeds were subjected to the following procedures: reduction of initial moisture content (r), heat shock (CT), and slow (SL) or fast drying (SR) for 48 hours. The combination of these procedures formed the treatments: primed seeds without drying, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL, and rCTSR, besides a control (seeds without priming). Seeds primed and those dried slowly expressed higher germination percentage. No difference was observed among treatments for seedling emergence percentage. The control took more time to express maximum emergence than the other treatments. Seeds subjected to heat shock presented higher values of electrical conductivity than those that did not undergo this treatment. The physiological quality of eggplant seeds gained with priming is maintained after drying. The drying of primed eggplant seeds should be preferably performed slowly, with or without reduction of initial moisture content.O objetivo deste trabalho foi avaliar a qualidade fisiológica de sementes de berinjela osmocondicionadas submetidas à secagem. Utilizaram-se sementes de berinjela, cultivar Embu, condicionadas em solução aerada de KNO3 (‑0,8 MPa), a 25ºC, por 48 horas. As sementes foram submetidas aos seguintes procedimentos: redução do teor de água inicial (r), choque térmico (CT) e secagem lenta (SL) ou rápida (SR) por 48 horas. As combinações desses procedimentos constituíram os tratamentos: sementes condicionadas e sem secagem, SL, SR, CTSL, CTSR, rSL, rSR, rCTSL e rCTSR, além da testemunha (sementes sem condicionamento). As sementes condicionadas e as secas lentamente expressaram maior percentagem de germinação. Não houve diferença entre os tratamentos quanto à percentagem de emergência de plântulas. A testemunha levou mais tempo para alcançar a máxima emergência do que os demais tratamentos. As sementes submetidas ao choque térmico apresentaram maiores valores de condutividade elétrica do que as que não passaram por esse tratamento. A qualidade fisiológica das sementes de berinjela obtida com o condicionamento é mantida após a secagem. A secagem de sementes de berinjela condicionadas deve ser realizada preferencialmente de forma lenta, com ou sem redução do teor de água inicial

    Extending the ecological distribution of Desmonostoc genus: proposal of Desmonostoc salinum sp. nov., a novel Cyanobacteria from a saline–alkaline lake

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    Cyanobacteria is an ancient phylum of oxygenic photosynthetic microorganisms found in almost all environments of Earth. In recent years, the taxonomic placement of some cyanobacterial strains, including those belonging to the genus Nostoc sensu lato, have been reevaluated by means of a polyphasic approach. Thus, 16S rRNA gene phylogeny and 16S–23S internal transcribed spacer (ITS) secondary structures coupled with morphological, ecological and physiological data are considered powerful tools for a better taxonomic and systematics resolution, leading to the description of novel genera and species. Additionally, underexplored and harsh environments, such as saline–alkaline lakes, have received special attention given they can be a source of novel cyanobacterial taxa. Here, a filamentous heterocytous strain, Nostocaceae CCM-UFV059, isolated from Laguna Amarga, Chile, was characterized applying the polyphasic approach; its fatty acid profile and physiological responses to salt (NaCl) were also determined. Morphologically, this strain was related to morphotypes of the Nostoc sensu lato group, being phylogenetically placed into the typical cluster of the genus Desmonostoc. CCM-UFV059 showed identity of the 16S rRNA gene as well as 16S–23S secondary structures that did not match those from known described species of the genus Desmonostoc, as well as distinct ecological and physiological traits. Taken together, these data allowed the description of the first strain of a member of the genus Desmonostoc from a saline–alkaline lake, named Desmonostoc salinum sp. nov., under the provisions of the International Code of Nomenclature for algae, fungi and plants. This finding extends the ecological coverage of the genus Desmonostoc, contributing to a better understanding of cyanobacterial diversity and systematics

    Checklist of the birds of Mato Grosso do Sul state, Brazil: diversity and conservation

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    Several phytogeographic regions (Cerrado, Pantanal, Atlantic Forest, Gran Chaco, and Chiquitano Dry Forests) converge in the state of Mato Grosso do Sul, Brazil, and influence regional biodiversity. Despite a list of birds in the state of Mato Grosso do Sul being published by Nunes et al. (2017), it is necessary to update and critically review avifauna records. In this study, we gathered the results of several records obtained from species lists and online data platforms of the 336 sites in this state over the last decades and grouped them into Main (Primary and Secondary) and Tertiary Lists. The avifauna of Mato Grosso do Sul is composed of 678 species, of which 643 (95%) have records proving their occurrence (Primary List), whereas 34 still lack documentation (Secondary List). The number of related species for Mato Grosso do Sul represents 34% of the Brazilian avifauna. Some species stand out for their unique occurrence in Mato Grosso do Sul, such as Melanerpes cactorum, Celeus lugubris, Phaethornis subochraceus, and Cantorchilus guarayanus, reflecting the influence of different phytogeographic regions of the Chaco and Chiquitano Dry Forests. Migrants represent 20% of the bird community occurring in the state, of which 93 species correspond to migrants from various regions of South America (south and west) and 40 to boreal migrants. Thirty-three species perform nomadic movements across the Pantanal Plain and other regions of the state. Thirty-one species are included in some conservation-threatened categories of global and/or national endangered species lists. Other 30 species are included in the near-threatened category at the global level and 23 at the national level. In addition, species typical of dry forests (in Serra da Bodoquena and Maciço do Urucum) and those from the Atlantic Forest in the south of the state deserve attention due to their restricted distribution and the high anthropogenic pressure on their habitat

    Checklist of the birds of Mato Grosso do Sul state, Brazil: diversity and conservation

    Get PDF
    Several phytogeographic regions (Cerrado, Pantanal, Atlantic Forest, Gran Chaco, and Chiquitano Dry Forests) converge in the state of Mato Grosso do Sul, Brazil, and influence regional biodiversity. Despite a list of birds in the state of Mato Grosso do Sul being published by Nunes et al. (2017), it is necessary to update and critically review avifauna records. In this study, we gathered the results of several records obtained from species lists and online data platforms of the 336 sites in this state over the last decades and grouped them into Main (Primary and Secondary) and Tertiary Lists. The avifauna of Mato Grosso do Sul is composed of 678 species, of which 643 (95%) have records proving their occurrence (Primary List), whereas 34 still lack documentation (Secondary List). The number of related species for Mato Grosso do Sul represents 34% of the Brazilian avifauna. Some species stand out for their unique occurrence in Mato Grosso do Sul, such as Melanerpes cactorum, Celeus lugubris, Phaethornis subochraceus, and Cantorchilus guarayanus, reflecting the influence of different phytogeographic regions of the Chaco and Chiquitano Dry Forests. Migrants represent 20% of the bird community occurring in the state, of which 93 species correspond to migrants from various regions of South America (south and west) and 40 to boreal migrants. Thirty-three species perform nomadic movements across the Pantanal Plain and other regions of the state. Thirty-one species are included in some conservation-threatened categories of global and/or national endangered species lists. Other 30 species are included in the near-threatened category at the global level and 23 at the national level. In addition, species typical of dry forests (in Serra da Bodoquena and Maciço do Urucum) and those from the Atlantic Forest in the south of the state deserve attention due to their restricted distribution and the high anthropogenic pressure on their habitat

    Lutzomyia longipalpis Saliva Induces Heme Oxygenase-1 Expression at Bite Sites

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    Sand flies bite mammalian hosts to obtain a blood meal, driving changes in the host inflammatory response that support the establishment of Leishmania infection. This effect is partially attributed to components of sand fly saliva, which are able to recruit and activate leukocytes. Our group has shown that heme oxygenase-1 (HO-1) favors Leishmania survival in infected cells by reducing inflammatory responses. Here, we show that exposure to sand fly bites is associated with induction of HO-1 in vivo. Histopathological analyses of skin specimens from human volunteers experimentally exposed to sand fly bites revealed that HO-1 and Nrf2 are produced at bite sites in the skin. These results were recapitulated in mice ears injected with a salivary gland sonicate (SGS) or exposed to sand fly bites, indicating that vector saliva may be a key factor in triggering HO-1 expression. Resident skin macrophages were the main source HO-1 at 24–48 h after bites. Additionally, assays in vivo after bites and in vitro after stimulation with saliva both demonstrated that HO-1 production by macrophages was Nrf2-dependent. Collectively, our data demonstrates that vector saliva induces early HO-1 production at the bite sites, representing a major event associated with establishment of naturally-transmitted Leishmania infections

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Bird-termite interactions in Brazil: A review with perspectives for future studies

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    Ibicaba revisitada outra vez: espaço, escravidão e trabalho livre no oeste paulista

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    Ibicaba Farm, property of Senator Nicolau Pereira de Campos Vergueiro during the 19th century, was the subject of studies that focused on the experience with the sharecropping system. This article intends to undertake a revisit to Ibicaba through new lenses of observation. At first, it tries to insert Vergueiro's farm in the context of the changing World-economy of the first decades of the nineteenth century, and then highlight the importance of the spatial dimension of reality in this historical context. In the following two subitems, which constitute the core of the article, an analysis is made of the protocols - especially spatial - of control of the workers, used by the Vergueiros in order to extract the maximum of labor from slaves and sharecroppers, as well as the strategies that captives and immigrants used to escape from this surveillance. Finally, a brief recapitulation of the main points exposed and some considerations about the tensions that emerged in Ibicaba during the studied period are made.A Fazenda Ibicaba, propriedade do Senador Nicolau Pereira de Campos Vergueiro ao longo do século XIX, foi objeto de estudos que enfocaram a experiência com o sistema de parceria que ela abrigou. Este artigo pretende revisitar Ibicaba por meio de novas lentes de observação. Em um primeiro momento, buscar-se-á inserir a fazenda de Vergueiro no contexto de mudança pela qual a Economia-mundo passava nas primeiras décadas do Oitocentos para, em seguida, salientar a importância que a dimensão espacial da realidade cumpria nesse contexto histórico. Nos dois subitens seguintes, que constituem o núcleo do artigo, analisam-se os protocolos - sobretudo espaciais - de controle da mão de obra utilizados pelos Vergueiro, com vistas à máxima extração de trabalho de escravos e colonos, bem como as estratégias de que cativos e imigrantes lançaram mão para escapar dessa vigilância. Faz-se, ao fim, uma breve recapitulação dos principais pontos expostos e algumas considerações sobre as tensões que emergiram em Ibicaba durante o período estudado
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