52 research outputs found

    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

    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

    The nature of rhetoric in the chanson de geste

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    Upper Gastrointestinal Involvement in Crohn Disease: Histopathologic and Endoscopic Findings

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    Studies describing the prevalence of upper gastrointestinal (GI) Crohn disease (CD) and its histopathologic changes have been inconsistent as a result of different definitions used for upper GI involvement, diverse populations, and varying indications for endoscopy. We reviewed the literature describing endoscopic findings and histologic lesions in gastric and duodenal mucosa of patients with established CD. PubMed, EMBASE, and the Cochrane Library were searched for gastroduodenal biopsy findings in patients with CD from 1970 to 2014. We included all retrospective and prospective studies in adults. We calculated the prevalence of the most common endoscopic and histopathological findings among patients with overall CD and upper GI CD. Of the 385 articles identified, 20 eligible studies were included. A total of 2511 patients had CD and 815 had upper GI CD. In the CD group, the most common histopathological finding was nonspecific gastric inflammation in 32% of patients, followed by gastric granuloma in 7.9%. Focal gastritis was prevalent in 30.9% of patients. In the upper GI CD group, gastric inflammation was present in 84% of patients, followed by duodenal inflammation in 28.2% and gastric granuloma in 23.2%. The most common gastric endoscopic finding in patients with CD was erythema in 5.9%, followed by erosions in 3.7%. Duodenal endoscopic findings included ulcers and erythema in 5.3% and 3.0% of patients, respectively. We found a prevalence of 34% for CD involving the upper GI tract across these 20 studies. Routine upper endoscopy with biopsies of the upper GI tract in the diagnostic workup of patients with CD can correctly classify the distribution and extent of the disease
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