14 research outputs found

    Helmintos de duas espécies do gênero Amazona Lesson, 1830 apreendida e recolhida pelo Cetas/Ibama no Estado do Piauí / Helminths of two species of the Amazona genus Lesson, 1830 seized and collected by Cetas / Ibama in the State of Piaui

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    O Brasil apresenta as aves como o grupo de animais mais afetados pelo comércio ilegal, devido principalmente o alto valor econômico e beleza. Além da redução na biodiversidade, as condições precárias das aves provenientes do tráfico também podem trazer riscos, pois muitos destes animais silvestres transmitem doenças ao homem. Esta pesquisa teve como objetivo identificar a fauna parasitária de duas espécies do gênero Amazona apreendidas e recolhidas pelo Cetas/Ibama no Estado do Piauí. No período de maio de 2018 a junho de 2019, foram recebidas nove aves já mortas, sendo oito Amazona aestiva e uma Amazona farinosa. Dos exemplares examinados, 55.5% (n = 5), quatro A. aestiva e uma A. farinosa, apresentaram resultado positivo para nematoides. Todos os nematoides foram identificados como Ascaridia hermaphrodita. Pesquisas envolvendo parasitismo em animais oriundos de tráfico podem contribuir para o entendimento da saúde ambiental, o qual poderá ser utilizado em ações de prevenção, visto que as aves do presente estudo culturalmente são capturadas para serem domesticadas podendo apresentar riscos à saúde pública

    Efeito da percentagem de finos na ativação alcalina de adobes / Effect of fines percentage on alkaline activation of adobes

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    A construção com terra tem grande potencial pelos menores custos, energia incorporada e impactos ambientais gerados. Porém, o adobe, técnica construtiva que utiliza terra, apresenta elevada suscetibilidade à ação da água. A ativação alcalina é um método de estabilização que pretende melhorar esta característica. A presente pesquisa trata-se da análise da influência da quantidade de ligante alcalino ativado e de diferentes percentagens de finos na resistência mecânica e à ação da água dos adobes. A pesquisa tem como objetivo identificar a influência do teor de ligante alcalino (1%, 2% e 3%) no desempenho dos blocos; verificar a influência da quantidade de finos (10%, 20% e 30%) no desempenho da ativação alcalina; e verificar o efeito das variáveis anteriores na resistência à ação da água e à compressão nos adobes ativados alcalinamente. No estudo foram utilizados os seguintes materiais: solo, caulim, metacaulim (MK), resíduo cerâmico (RC), silicato de sódio, hidróxido de sódio, água destilada e água. Primeiramente o solo foi caracterizado. Logo após passou-se a produção dos ligantes utilizando o método de Polisialatosiloxo de sódio. O ligante foi misturado manualmente ao solo, acrescido de diferentes quantidades de caulim, e logo após foram moldados corpos de prova cúbicos com 5 cm de aresta, que passaram 7 e 28 dias de cura em estufa a 65º C. Posteriormente foram realizados os ensaios de resistência à água e à compressão. A resistência à ação da água diminuiu com o aumento da quantidade de finos. Inverso do que ocorreu com o aumento da quantidade de ligante, que fez aumentar a durabilidade. No que diz respeito à resistência à compressão os resultados mostram-se similares ao da resistência à água. A resistência mecânica dos blocos tende a diminuir com o aumento do tempo em estufa, sendo os de 7 dias mais resistentes que os de 28

    Estabilização alcalina de solos Cauliníticos para fabricação de Adobes / Alkaline stabilization of kaolinitic soils for adobe manufacturing

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    O adobe é certamento um dos materiais mais antigo da humanidade e de menor custo energético entre os materiais de construção. Devido ao seu processo produtivo esse material se torna suceptível á ação da água, dessa forma, sendo necessário a sua estabilização. Um novo método de estabilização que vem com a proposta de aumentar a durabilidade do adobe é a ativação alcalina. Nesse caso o ligante alcalino é formado pela dissolução de partículas ricas em sílica e alumina submetidos a um ambiente alcalino. O presente trabalho tem como objetivo realizar a estabilização do solo caulinitico por meio da ativação alcalina para fabricação de adobes sem a adição de precursores geopoliméricos, com o intuito de melhorar suas caracteristicas mecânicas e resistência a ação da agua. Foram elaboradas misturas com o solo no estado natural (SN) e solo calcinado (SC) com dois tipos de concentrações molares para as soluções alcalinas (10 mols e 12 mols). Para que o solo tivesse uma reatividade melhor o mesmo foi moído até passar na peneira de nº 325. As amostras foram submetidas a dois proceso de cura diferentes (cura ambiente 28ºC e cura eletrônica 65ºC) e realizada os ensaios de imersão à agua e resistência à compressão simples. Os resultados parciais mostram que os adobes produzidos com essas misturam tem uma grande durabilidade à ação da água com absorção dentro do previsto em norma para solo-cimento e resistência á compressão que variam de 6,3 MPa à 21,7 MPa. Possibilitando a produção em larga escala de adobes para produção de residências de interesse social com baixo custo energético no proceso produtivo

    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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    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

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    Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

    Consistent patterns of common species across tropical tree communities

    No full text
    International audienceAbstract Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations 1–6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories 7 , we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

    Consistent patterns of common species across tropical tree communities

    No full text
    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1–6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees
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