17 research outputs found

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

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    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets

    Pervasive gaps in Amazonian ecological research

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    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

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

    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 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

    Eimerid coccidia from capybaras (Hydrochoerus hydrochaeris) in southern Bahia, Brazil CoccĂ­dios eimerĂ­dios em capivaras (Hydrochoerus hydrochaeris) no sul da Bahia

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    Two eimerid coccidia are reported in a capybara (Hydrochoerus hydrochaeris) population kept in captivity in the south of Bahia, northeastern Brazil (14Âș 47' 57.89"S and 39Âș 10' 10.58" W). Oocysts of Eimeria ichiloensis are subspheroidal to ellipsoidal, 26.2 x 21.7mm with bi-layered wall, the outer yellow and sculptured and the inner, dark and smooth. Residuum is absent, but usually 2-3 polar granules are present. Sporocysts are ovoid, 12.0 x 7.6mm. Stieda body and sporocyst residuum are present. Oocysts of Eimeria trinidadensis are subspheroidal to ellipsoidal, 22.2 x 19.6mm with bi-layered wall, the outer yellow and smooth, and the inner dark and smooth. Residuum is absent, but one polar granule is present. Sporocysts are ovoid, 11.0 x 6.9mm. Stieda body and sporocyst residuum are present. Based on these descriptions and previous ones it can be concluded that these coccidea species are widely dispersed in capybaras in South America.Duas espĂ©cies de Eimeria foram relatadas em capivaras Hydrochaeris hydrochaeris cativas no sul da Bahia, nordeste do Brasil (14Âș 47' 57.89"S and 39Âș 10' 10.58" W). Os oocistos de Eimeria ichiloensis sĂŁo sub-esferoidais a elipsoidais, 26,2 x 21,7mm. Apresentam parede dupla, sendo a externa amarela e esculpida e a interna, escura e lisa. ResĂ­duo estĂĄ ausente, mas usualmente 2-3 grĂąnulos polares estĂŁo presentes. Os esporocistos sĂŁo ovĂłides, 12,0 x 7,6mm. Corpo de Stieda e resĂ­duo do esporocisto estĂŁo presentes. Oocistos de Eimeria trinidadensis sĂŁo sub-esferoidais a elipsoidais, 22,2 x 19,6mm. Apresentam parede dupla, sendo a externa amarela e lisa e a interna, escura e lisa. ResĂ­duo estĂĄ ausente, mas um grĂąnulo polar estĂĄ presente. Os esporocistos sĂŁo ovĂłides, 11,0 x 6,9mm. Corpo de Stieda e resĂ­duo do esporocisto estĂŁo presentes. Baseado nestas descriçÔes e em descriçÔes prĂ©vias foi possĂ­vel concluir que estas espĂ©cies estĂŁo amplamente dispersas em capivaras na AmĂ©rica do Sul

    A nova polĂ­tica dos governadores The new politics of governors

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    Este artigo analisa o incremento do poder dos governadores e o ressurgimento dos interesses polĂ­ticos estaduais como determinantes do comportamento dos congressistas durante a transição democrĂĄtica. Para isso, os autores explicam como os governos militares fracassaram em reduzir a influĂȘncia das redes polĂ­ticas estaduais sobre a classe polĂ­tica e como os governadores remergiram e tornaram-se atores fundamentais para derrubar o regime autoritĂĄrio. Por fim, fornecem exemplos de como os interesses estaduais e os governadores tiveram papel-chave durante a transição e ainda continuam a tĂȘ-lo na polĂ­tica brasileira contemporĂąnea.<br>This article analyzes the increase in the power of state governors and the resurgence of the state-based interests of the members of the National Congress during Brazil's transition to democracy. The 1964-85 military regime's failure to reduce the influence of state-based interests and the reemergence of the state governors as powerful political actors in Brazil are explained. Examples are provided of how state interests and state governors have influenced the transition process and continue to play key roles in contemporary Brazilian politics

    ContribuiçÔes da Sociologia na América Latina à imaginação sociológica: anålise, crítica e compromisso social Sociology's contribution in Latin America to sociological imagination: analysis, critique, and social commitment

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    O artigo aborda o papel desempenhado pela Sociologia na anålise dos processos de transformação das sociedades latino-americanas, no acompanhamento do processo de construção do Estado e da Nação, na problematização das questÔes sociais na América Latina. São analisados seis períodos na Sociologia na América Latina e no Caribe: I) a herança intelectual da Sociologia ; II) a sociologia da cåtedra; III) O período da "Sociologia Científica" e a configuração da "Sociologia Crítica"; IV) a crise institucional, a consolidação da "Sociologia Crítica" e a diversificação da sociologia; V) a sociologia do autoritarismo, da democracia e da exclusão; VI) a consolidação institucional e a mundialização da sociologia da América Latina (desde o ano de 2000), podendo-se afirmar que os traços distintivos do saber sociológico no continente foram: o internacionalismo, o hibridismo, a abordagem crítica dos processos e conflitos das sociedades latino-americanas e o compromisso social do sociólogo.<br>The article focuses on the role played by Sociology in the analysis of processes of change in Latin American societies, in the process of construction of Nation and State, in the debate of social issues in Latin America and the Caribbean. Six periods in Sociology in Latin America and the Caribbean are examined: I) sociology's intellectual legacy; II) sociology as a cathedra; III) the period of "Scientific Sociology"; IV) the institutional crisis, the consolidation of "Critical Sociology", and the diversifying of sociology; V) sociology of authoritarianism, democracy and exclusion; VI) institutional consolidation and globalization of Latin American sociology (since 2000). It may be said that the distinctive features of sociological knowledge in the continent were: internationalism, hybridism, the critical approach to processes and conflicts of Latin American societies, and the sociologist social commitment
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