8 research outputs found

    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

    Get PDF

    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

    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

    Caracterização molecular de isolados de Toxoplasma gondii obtidos de crianças com toxoplasmose congênita no Estado de Minas Gerais

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    Exportado OPUSMade available in DSpace on 2019-08-13T20:54:15Z (GMT). No. of bitstreams: 1 tese_29_1_.06.11_depois_da_banca.pdf: 10031144 bytes, checksum: a15f59aaee65e4d8ad756e48192cd134 (MD5) Previous issue date: 31Toxoplasma gondii é um parasito apicomplexo amplamente distribuído de grande importância médica. Em humanos, a transmissão congênita tem sido responsabilizada pela ocorrência de abortos, natimortos, debilidade e mortalidade neonatal. A infecção por T. gondii pode ser diagnosticada indiretamente, através de métodos sorológicos, e diretamente por isolamento do parasito em camundongos (bioensaio) e pela Reação em Cadeia da Polimerase (PCR). Através do Programa Estadual de Triagem Neonatal em Minas Gerais, 146.307 crianças foram submetidas à pesquisa de anticorpos IgM anti-T. gondii, em amostras de sangue seco em papel filtro. Dessas, 220 que apresentaram resultado positivo/duvidoso foram selecionadas para esteestudo. Foram coletadas amostras de sangue periférico desses recémnascidos para PCR e bioensaio. A toxoplasmose foi confirmada em 178crianças que apresentaram anticorpos IgG persistentes até o 12º mês de vida. A amplificação do gene B1 por nested PCR foi realizada em todas as amostras de sangue verificando 64/220 (29,1%) crianças positivas por PCR (31,46% de sensibilidade e 80,95% de especificidade). A nested PCR do gene B1 não se mostrou suficientemente sensível e específica para ser uma ferramenta útilpara o diagnóstico da toxoplasmose congênita em amostras de sangueperiférico de recém-nascidos. Através do bioensaio foram obtidos 27 isolados de T. gondii. A presença do T. gondii foi evidenciada no sangue em 15,2% (27/178) dos recém-nascidos com toxoplasmose congênita. Os isolados foram divididos em três grupos de acordo com o fenótipo de virulência para camundongos. Quatorze isolados (54%) foram caracterizados como de virulência intermediária, dez (38%) como virulentos e apenas dois (8%) foram identificados como avirulentos. A variabilidade genética dos isolados foi analisada por Tamanho de Fragmento de Restrição (PCR-RFLP) em 11 loci (SAG1, 53SAG2, SAG2 alt, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico). As cepas RH (Tipo I), ME49 (Tipo II) e VEG (Tipo III) foram utilizadas como cepas de referência. O genótipo completo foi obtido em 25/27 (92,6%) dos isolados. Quatorze genótipos diferentes foram identificados, sendo dozenovos genótipos, e um isolado com infecção mista. Dois genótipos encontrados são comuns no Brasil (BrII e BrIII). Não foi identificado nenhum genótipo arquétipo tipo I, II ou III nos isolados estudados. Não foi observada associação entre os sinais clínicos da toxoplasmose congênita e os resultados obtidos pelo diagnóstico molecular, bioensaio, virulência e genotipagem dos isolados. Este estudo confirma a variabilidade genotípica do parasito no Brasil além de ser oprimeiro registro de genotipagem de isolados de sangue de recém nascidos em nosso país.Toxoplasma gondii is a widely distributed Apicomplexa parasite with great medical importance. Congenital toxoplasmosis has been associated with abortion and stillborn, debility and neonatal mortality. Toxoplasmosis can be diagnosed through serologic methods or by directed methods: parasite isolation in mice (bioassay) or Polimerase Chain Reaction assay (PCR). The Programa Estadual de Triagem Neonatal (Neonatal Screening State Program) in Minas Gerais state, evaluated 146.307 children by anti-T. gondii IgM antibodies search, using blood samples dried in filter paper. Out of those, 220 newborns presented positive/doubtful results and were selected for this study. New blood samples were collected from newborns for PCR and bioassay. Toxoplasmosis was confirmed in 178 children who had specific IgG antibodies after 12 months. The B1 gene amplification by nested PCR was performed on all 220 blood samples. Sixty-four (29,1%) children presented positive results by PCR (31,46% sensibility and 80,95% specificity). This PCR in peripheral blood was not sufficiently sensitive or specific to be considered as an useful tool for the diagnosis of congenital toxoplasmosis in newborns. Using bioassay in mice, 27 T. gondii isolates were obtained. Parasitemia was detected in 15,2% (27/178) ofnewborns with congenital toxoplasmosis. T. gondii isolates were divided into three different groups according to the virulence in mice: Fourteen isolates (54%) were characterized as intermediate virulence, ten (38%) as virulent and only two (8%) as avirulent isolates. The genetic variability was assessed by Restricted Fragment Length Polymorphism (PCR-RFLP) in 11 loci (SAG1, 5+3SAG2, SAG2 alt, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico). The strains RH (Type I), ME49 (Type II) and VEG (Type III) were used as references strains. The complete genotyping was achieved in 25/27 isolates (92,6%). Fourteen different genotypes were identified: two previously described genotypes, common in Brazil (BrII and BrIII) and twelve new genotypes. One isolate presented mixed infection. No archetypal I, II or III genotype were found in the isolates studied. It was not observed association between clinical signs of congenital toxoplasmosis and the results obtained by molecular diagnosis, bioassay, virulence or genotyping of the isolates. This is the first report of isolation and genotyping of T. gondii from newborns blood in Brazil and confirms the genotypic variability of the parasites in our country

    Soroepidemiologia da toxoplasmose caprina e ovina no estado de Minas Gerais.

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    Exportado OPUSMade available in DSpace on 2019-08-13T19:11:08Z (GMT). No. of bitstreams: 1 dissertacaoufmg_carneiro2006_.pdf: 864291 bytes, checksum: 4db33ee4972632af2c744f54e8bec8c8 (MD5) Previous issue date: 29RESUMOO objetivo deste trabalho foi realizar um estudo soroepidemiológico da toxoplasmose caprina e ovina no Estado de Minas Gerais. Foram avaliados soros de 767 caprinos e 711 ovinos provenientes das regiões Centro, Oeste e Sul do Estado além de questionários com dados da propriedade e individuais de cada animal. O ELISA se mostrou sensível, específico e reprodutível no diagnóstico da toxoplasmose caprina e ovina. Para os caprinos, a prevalência encontrada foi de 43,0% e 46,0% através do ELISA e RIFI, respectivamente. Foi identificado uma maior prevalência de anticorpos anti-T. gondii em caprinos de raça pura. Não foi observada associação significativa entre a positividade para toxoplasmose e o sexo ou idade dos animais. Os fatores de risco para a infecção por T. gondii em caprinos foram: idade superior a 36 meses (OR= 1,21 IC 95% 1,02 1,44), presença de aprisco (OR= 1,83 IC 95%1,01 3,31) e tipo racial puro (OR= 2,49 IC 95% 1,11 5,59). Para os ovinos, foi encontrada uma prevalência de 31,0% através do ELISA e 43,0% utilizando a RIFI. Foi observada diferença estatística na relação entre a prevalência da toxoplasmose e a faixa etária dos ovinos. Para as variáveis sexo e tipo racial não foram observadas associações. O único fator de risco encontrado para infecção por T. gondii em ovinos do Estado de Minas Gerais foi a idade. Animais com idade superior a 36 meses tiveram risco 1,45 maior de estarem infectados, quando comparados com os mais novos (IC 95% 1,20 1,74). Foi observado que 26,8% e 19,0% dos caprinos e ovinos, respectivamente, possuem anticorpos IgG para T. gondii de baixa avidez. Este resultado sugere a presença de animais em fase recente da toxoplasmose nas regiões do Estado de Minas Gerais

    Early diagnosis of congenital toxoplasmosis in newborn infants using IgG subclasses against two Toxoplasma gondii recombinant proteins

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    The aim of this work was to evaluate the utility of ELISA-based testing of total IgG (IgGt) antibodies and its subclasses (IgG1, IgG2, IgG3 and IgG4) against soluble (STAg) and recombinant (rSAG1 and rMIC3) antigens of Toxoplasma gondii for diagnosing congenital toxoplasmosis. Sera from 217 newborns initially testing positive for specific IgM in filter paper dried blood spots were tested for specific IgM and IgG by ELFA-VIDAS®. Congenital toxoplasmosis was confirmed in 175 and ruled out in 42 infants. The validity of the ELISA tests was determined using the persistence of IgG antibodies (ELFA-VIDAS® kit) at the end of 12 months, which is considered the reference test for the diagnosis of congenital toxoplasmosis. The frequency of positivity with IgGt against STAg, rSAG1 and rMIC3 was found in 97.2%, 96.3% and 80.2%, respectively, of the newborns with confirmed congenital toxoplasmosis. IgG1 reacted with all three antigens, while IgG3 and IgG4 reacted preferentially with rMIC3. Higher mean values of reactivity (sample optical density/cut-off) were found for all subclasses when using rMIC3. All of the antigens showed high sensitivity and low specificity in detecting anti-T. gondii IgGt and IgG1 and low sensitivity and high specificity in detecting IgG3 and IgG4. In conclusion, the combined detection of IgG antibody subclasses against recombinant toxoplasmic antigens may be useful for the early diagnosis of congenital toxoplasmosis

    Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

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    International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora
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