20 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

    NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

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    Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset

    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

    Nutritional status of zinc and activity superoxide dismutase in chronic renal patients undergoing hemodialysis Estado nutricional del zinc y actividad de la enzima superóxido dismutasa en pacientes con enfermedad renal crónica en hemodiálisis

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    Introduction: Chronic kidney disease promotes changes in the zinc nutritional status and in the antioxidant defense system. This study assessed the relationship between the parameters of the zinc nutritional status and the activity of superoxide dismutase in patients with chronic renal failure who are receiving hemodialysis. Methods: 134 individuals, aged between 18 and 85 years, were divided into two groups: case group (hemodialyzed patients, n = 63) and control group (n = 71). Zinc concentrations in plasma and erythrocytes were determined using the flame atomic absorption spectrophotometry technique. The activity of superoxide dismutase enzyme was determined according to Ransod kit. Results: The mean values of plasma zinc were 62.02 &plusmn; 13.59 &mu;g/dL and 65.58 &plusmn; 8.88 &mu;g/dL, and for erythrocytary zinc the values were 54.52 &plusmn; 22.82 &mu;gZn/gHb and 48.01 &plusmn; 15.08 &mu;gZn/gHb for the chronic renal patients and the control group, respectively. The activity of superoxide dismutase was significantly lower in patients when compared with the control group (p Introducción: La enfermedad renal crónica produce cambios en el estado nutricional del zinc y en el sistema de defensa antioxidante. Por lo tanto, este estudio investigó la relación entre parámetros del estado nutricional del zinc y la actividad de la enzima superóxido dismutase en pacientes con enfermedad renal crónica en hemodiálisis. Métodos: Se incluyeron 134 personas, de 20 a 59 años de edad que fueron divididos en dos grupos: grupo caso (pacientes en hemodiálisis, n = 63) y grupo control (n = 71). El zinc plasmático y eritrocitario fueron analizados según el método de espectrofotometría de absorción atómica. La actividad de la enzima superóxido dismutasa fue analizada de acuerdo con Kit Ransod. Resultados: Los valores medios de zinc plasmatico fueron 62,02 &plusmn; 13,59 &mu;g/dL y 65,58 &plusmn; 8,88 &mu;g/dL y los valores de zinc eritrocitario fueron 54,52 &plusmn; 22,82 &mu;gZn/gHb y 48,01 &plusmn; 15,08 &mu;gZn/gHb, en los pacientes en hemodialisis y en el grupo control, respectivamente. La actividad de la superoxido dismutasa fue significantemente inferior en los pacientes que en controles (p < 0,05). Conclusiones: La actividad de la superóxido dismutasa en pacientes con enfermedad renal crónica en hemodiálisis, que es influenciada por la concentración del zinc, fue significantemente inferior. Hubo una respuesta inadecuada por la enzima al estrés oxidativo en pacientes en hemodiálisis

    ERICA: prevalências de hipertensão arterial e obesidade em adolescentes brasileiros

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    OBJECTIVE:To estimate the prevalence of arterial hypertension and obesity and the population attributable fraction of hypertension that is due to obesity in Brazilian adolescents. METHODS: Data from participants in the Brazilian Study of Cardiovascular Risks in Adolescents (ERICA), which was the first national school-based, cross-section study performed in Brazil were evaluated. The sample was divided into 32 geographical strata and clusters from 32 schools and classes, with regional and national representation. Obesity was classified using the body mass index according to age and sex. Arterial hypertension was defined when the average systolic or diastolic blood pressure was greater than or equal to the 95th percentile of the reference curve. Prevalences and 95% confidence intervals (95%CI) of arterial hypertension and obesity, both on a national basis and in the macro-regions of Brazil, were estimated by sex and age group, as were the fractions of hypertension attributable to obesity in the population. RESULTS:We evaluated 73,399 students, 55.4% female, with an average age of 14.7 years (SD = 1.6). The prevalence of hypertension was 9.6% (95%CI 9.0-10.3); with the lowest being in the North, 8.4% (95%CI 7.7-9.2) and Northeast regions, 8.4% (95%CI 7.6-9.2), and the highest being in the South, 12.5% (95%CI 11.0-14.2). The prevalence of obesity was 8.4% (95%CI 7.9-8.9), which was lower in the North region and higher in the South region. The prevalences of arterial hypertension and obesity were higher in males. Obese adolescents presented a higher prevalence of hypertension, 28.4% (95%CI 25.5-31.2), than overweight adolescents, 15.4% (95%CI 17.0-13.8), or eutrophic adolescents, 6.3% (95%CI 5.6-7.0). The fraction of hypertension attributable to obesity was 17.8%. CONCLUSIONS:ERICA was the first nationally representative Brazilian study providing prevalence estimates of hypertension in adolescents. Regional and sex differences were observed. The study indicates that the control of obesity would lower the prevalence of hypertension among Brazilian adolescents by 1/5. DESCRIPTORS:Adolescent. Obesity, epidemiology. Hypertension, epidemiology. Cross-Sectional Studies.OBJETIVO: Estimar as prevalências de hipertensão arterial e obesidade e a fração atribuível populacional de hipertensão arterial devida à obesidade em adolescentes brasileiros. MÉTODOS: Foram avaliados dados dos participantes do Estudo de Riscos Cardiovasculares em Adolescentes, estudo seccional l nacional de base escolar. A amostra foi dividida em 32 estratos geográficos e conglomerados de escolas e turmas, com representatividade nacional, macrorregional e de capitais. Obesidade foi classificada pelo índice de massa corporal segundo idade e sexo. Considerou-se hipertensão arterial a média da pressão arterial sistólica ou diastólica maior ou igual ao percentil 95 da curva de referência. Foram estimadas prevalências e intervalos de confiança de 95% (IC95%) de hipertensão arterial e de obesidade, nacionais e nas macrorregiões do País, por sexo e grupo etário, assim como as frações de hipertensão atribuíveis à obesidade na população. RESULTADOS: Foram avaliados 73.399 estudantes, 55,4% do sexo feminino, com média de idade 14,7 anos (DP = 1,6). A prevalência de hipertensão arterial foi 9,6% (IC95% 9,0-10,3); sendo as mais baixas observadas nas regiões Norte, 8,4% (IC95% 7,7-9,2) e Nordeste, 8,4% (IC95% 7,6-9,2) e a mais alta na região Sul, 12,5% (IC95% 11,0-14,2). A prevalência de obesidade foi 8,4% (IC95% 7,9-8,9), mais baixa na região Norte e mais alta na Sul. As prevalências de hipertensão arterial e obesidade foram maiores no sexo masculino. Adolescentes com obesidade tiveram prevalência de hipertensão arterial mais elevada, 28,4% (IC95% 25,5-31,2), do que aqueles com sobrepeso, 15,4% (IC95% 13,8-17,0), ou eutróficos, 6,3% (IC95% 5,6-7,0). A fração de hipertensão arterial atribuível à obesidade foi de 17,8%. CONCLUSÕES: O ERICA foi o primeiro estudo brasileiro com representatividade nacional a estimar a prevalência de hipertensão arterial aferida em adolescentes. A fração da prevalência de hipertensão arterial atribuível à obesidade mostrou que cerca de 1/5 dos hipertensos poderiam não ser hipertensos se não fossem obesos. DESCRITORES: Adolescente. Obesidade, epidemiologia. Hipertensão, epidemiologia. Prevalência. Estudo Transversal

    Sealing Ability of Root-end Filling Materials

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    Álbum fotográfico: um mapa de cenários discursivos na produção acadêmica brasileira sobre aulas experimentais de Ciências

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