Universidade Federal de Rondônia

About: Universidade Federal de Rondônia is a education organization based out in Porto Velho, Brazil. It is known for research contribution in the topics: Population & Snake venom. The organization has 2232 authors who have published 2614 publications receiving 18062 citations.

Spatial-temporal dynamics and sources of total Hg in a hydroelectric reservoir in the Western Amazon, Brazil

Abstract: Damming rivers to construct hydroelectric reservoirs results in a series of impacts on the biogeochemical Hg cycle. For example, modifying the hydrodynamics of a natural watercourse can result in the suspension and transport of Hg deposits in the water column, which represents an exposure risk for biota. The objective of this study was to evaluate the influences of seasonality on the dispersion of total Hg in the Hydroelectric Power Plant (HPP)-Samuel Reservoir (Porto Velho/Brazil). Sampling campaigns were performed during the three following hydrological periods characteristic of the region: low (Oct/2011), ebbing (May/2012), and high (Feb/2013) water. Sediment profiles, suspended particulate matter (SPM), and aquatic macrophytes (Eicchornia crassipes and Oryza spp.) were collected, and their Hg concentrations and isotopic and elemental C and N signatures were determined. The drainage basin significantly influenced the SPM compositions during all the periods, with a small autochthonous influence from the reservoir during the low water. The highest SPM Hg concentrations inside the reservoir were observed during the high water period, suggesting that the hydrodynamics of this environment favor the suspension of fine SPM, which has a higher Hg adsorption capacity. The Hg concentrations in the sediment profiles were ten times lower than those in the SPM, indicating that large particles with low Hg concentrations were deposited to form the bottom sediment. Hg concentrations were higher in aquatic macrophyte roots than in their leaves and appeared to contribute to the formation of SPM during the low water period. In this environment, Hg transport mainly occurs in SPM from the Jamari River drainage basin, which is the primary source of Hg in this environment.

Acuracidade do professor na identificação de alunos com dificuldade de aprendizagem

Abstract: International studies have pointed out the teachers’ accuracy in identifying children with learning problems. In Brazil, however, there are no researches exploring this accuracy with direct indicators of students’ academic performance. The present study aimed: (1) compare the teachers’ rating with a direct evaluation of children’s academic performance; (2) probe the possibility of behavior problems affecting the teachers’ accuracy in the Academic Competence scale (AC) of the Social Skills Rating System (SSRS-BR); and (3) present preliminary validation data of this subscale. In two correlation studies with 49 children from Sao Paulo (SP) and 22 from Cacoal (RO), the results showed that the two indicators of academic competence were positively correlated each other and negatively with behavior problems, evidencing the validity for the teachers’ accuracy in the AC scale of SSRS-BR. Methodological and practical implications for further studies and for the screening of learning problems are discussed.

Influence of Maternal Fish Intake on the Anthropometric Indices of Children in the Western Amazon.

Abstract: We studied trends in fish intake among pregnant women living in the Madeira River Basin in Rondonia State, Brazil, to investigate the influence of maternal fish intake on anthropometric indices of children followed up to 5 years. Maternal fish intake was assessed using hair mercury concentrations of mothers and children at delivery and 6, 24, and 59 months. Data analysis was performed using a linear mixed-effect model. Mothers were predominantly young, had low incomes and limited schooling, and breastfed for >6 months. Only 1.9% of children had low birth weight. Anthropometric indices in approximately 80% of the study population showed Z-score values ranging from ≥−2 to ≤1. The influence of maternal fish intake on anthropometric indices, including height-to-age (H/A), weight-to-age (W/A), and weight-to-height (W/H) were not statistically significant after model adjustments. However, higher income and larger birth weight had a positive influence on H/A and W/A, whereas W/H gain was favored by higher maternal educational status and breastfeeding duration. Other variables (hemoglobin concentration and maternal age) had a positive significant influence on anthropometric indices. Maternal fish intake (or its attendant MeHg exposure) did not affect children growth. Nevertheless, it is advisable to avoid mercury-contaminated fish during pregnancy and childhood.

Dengue na Amazônia: aspectos epidemiológicos no Estado de Rondônia, Brasil, de 1999 a 2010

Abstract: Dengue is a viral, acute, and systemic disease that is mainly transmitted by the mosquito Aedes aegypti. It is spread through all 26 states of the Brazilian Federation and in the Federal District, and approximately 70% of all the world's notifications of dengue are recorded in Brazil. The objective of the present study is to analyze the epidemiology of dengue between 1999 and 2010 in Rondonia State, comparing the data obtained with that of the country as a whole during this period. As information sources, we used the official records from the National System for Notifiable Diseases (Sistema Nacional de Agravos de Notificacao), the State Agency of Sanitary Surveillance (Agencia Estadual de Vigilância Sanitaria), and the Department of Informatics (Departamento de Informatica) of the Brazilian Unified Health System (DATASUS). The data refer to the period from 1999 (the beginning of the notifications) to 2010 (the last year with complete data). Information was collected regarding the notified and confirmed cases, severe forms of the disease, the incidence rate, and the number of deaths. From the beginning of documentation, there was an exponential increase in the cases of dengue in the state. The number of reported cases increased from 969 in 1999 to 27,910 in 2010, which represents a 2,880% increase in notifications. The notifications were concentrated mainly in the capital, Porto Velho. In addition, the incidence rate increased from 7.63 to 365.9 per 100,000 inhabitants. Regarding the reporting of severe cases, there were increases in the number of all types of severe case expression and in the occurrence of deaths. It is necessary to develop public policies that prevent future epidemics to avoid a greater occurrence of the severe forms of the disease and, consequently, an increase in the number of deaths.

Heterogeneity of Multimedia Exposures to Neurotoxic Elements (Al, As, Cd, Pb, Mn, and Hg) in Breastfed Infants from Porto Velho, Brazil.

Abstract: Infant exposure to neurotoxic elements is a public health issue that needs monitoring with regard to breast milk composition. We studied six neurotoxic elements in breast milk samples at different stages of lactation in mothers from Porto Velho, Brazil. We used a flow-injection mercury system (FIMS) to determine total Hg concentrations and an inductively coupled plasma optical emission spectrometer (ICP-OES) to determine the concentrations of Al, As, Cd, Pb, and Mn in 106 donors of a human milk bank. Association rules analyses were applied to determine the pattern of binary and ternary mixtures of the measured exposants. The metal concentration was mostly below the limit of detection (LOD) for Cd (99%), Pb (84%), and Hg (72%), and it was above the LOD for As (53%), Mn (60%), and Al (82%), respectively. Median concentrations (dry weight) of Al, As, Hg, Mn, and Pb were 1.81 μg/g, 13.8 ng/g, 7.1 ng/g, 51.1 ng/g, and 0.43 μg/g, respectively. Al is singly the most frequent element to which infants are exposed. Occurring binary combination (> LOD) was 56% for Al-Mn, 41% for Al-As, 22% for Al-Hg, and 13% for Al-Pb. In 100% of neonates, exposure to Al-ethylmercury (EtHg) occurred through immunization with thimerosal-containing vaccines (TCV). Association rules analysis revealed that Al was present in all of the multilevel combinations and hierarchical levels and that it showed a strong link with other neurotoxic elements (especially with Mn, As, and Hg). (a) Nursing infants are exposed to combinations of neurotoxicants by different routes, dosages, and at different stages of development; (b) In breastfed infants, the binary exposures to Al and total Hg can occur through breast milk and additionally through TCV (EtHg and Al);