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PubMed | Centro Universitario Of Brasilia, Laboratorio Of Ecotoxicologia, Federal University of Rondônia and University of Brasilia
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

This study aims to evaluate the effects of maghemite nanoparticles (-Fe2O3) coated with meso-2, 3-dimercaptosuccinic acid (DMSA) stabilizer on the survival and reproduction of the aquatic snail Biomphalaria glabrata. The cumulative means of egg masses and eggs per individual in the control group at the end of 4weeks were 18.8 and 326.7, respectively. These values at the concentration of 1mg/L were 17.2 and 291.6; at 10mg/L, they were 19.6 and 334.4 ,and at 100mg/L, they were 14.3 and 311.1. Results showed no significant differences between the tested and the control groups at the level of p<0.05. Exposure of embryos for 10days showed absence of mortality, malformation, or hatching delay. X-ray microtomography confirmed the presence of nanoparticles in exposed individuals and showed the complete elimination of the nanoparticles after 30days in clean water. In the studied conditions, it is clear that -Fe2O3 coated with stabilizing DMSA did not alter the fecundity or the fertility of the snail B. glabrata after 4weeks of exposure, and accumulation was not present after 30days in clean water.

Dias R.I.,University of Brasilia | Dias R.I.,Centro Universitario Of Brasilia | Lima M.R.,University of Brasilia | Lima M.R.,State University Londrina
Wilson Journal of Ornithology | Year: 2015

Different ecological parameters are associated with the selection of nests and breeding sites in birds. Understanding nest-site selection and the subsequent consequences for reproductive success are critical to a full understanding of how natural selection shapes birds' nesting behavior. Between 2007 and 2008, we evaluated nest-site characteristics and nesting success of Tropical Screech-Owls (Megascops choliba) in an area of Cerrado interspersed with cultivated areas in central Brazil. We compared the characteristics of cavities used for nesting by owls and unused nesting cavities and modeled nest survival in MARK. Models were assessed using Akaike's Information Criterion for small sample sizes (AICc) and model averaging was used to infer model parameters. Tropical Screech-Owls nested in tree and termite-mound cavities. Nest success was 44.4%, with predation being the main cause of nest failure. We found that Tropical Screech-Owls nested in cavities with different orientations, and closer to the ground than unused cavities. Although the top-ranked models included nest height and nest concealment, multimodel inference showed that these variables had no clear effect on nest survival. Despite the lack of effect of these variables on nest survival, nest-site characteristics commonly associated with a cavity's microclimate (i.e., orientation of cavity entrance) may still have a stronger influence on nest-site selection. © 2015 The Wilson Ornithological Society.

PubMed | Pontifical Catholic University of Parana, Federal University of Bahia, Federal University of Health Sciences, Porto Alegre, Centro Universitario Of Brasilia and 2 more.
Type: Journal Article | Journal: Jornal de pediatria | Year: 2014

there are many questions and little evidence regarding the diagnosis and treatment of gastroesophageal reflux disease (GERD) in children. The association between GERD and cows milk protein allergy (CMPA), overuse of abdominal ultrasonography for the diagnosis of GERD, and excessive pharmacological treatment, especially proton-pump inhibitors (PPIs) are some aspects that need clarification. This review aimed to establish the current scientific evidence for the diagnosis and treatment of GERD in children.a search was conducted in the MEDLINE, PubMed, LILACS, SciELO, and Cochrane Library electronic databases, using the following keywords: gastroesophageal reflux; gastroesophageal reflux disease; proton-pump inhibitors; and prokinetics; in different age groups of the pediatric age range; up to May of 2013.abdominal ultrasonography should not be recommended to investigate gastroesophageal reflux (GER). Simultaneous treatment of GERD and CMPA often results in unnecessary use of medication or elimination diet. There is insufficient evidence for the prescription of prokinetics to all patients with GER/GERD. There is little evidence to support acid suppression in the first year of life, to treat nonspecific symptoms suggestive of GERD. Conservative treatment has many benefits and with low cost and no side-effects.there have been few randomized controlled trials that assessed the management of GERD in children and no examination can be considered the gold standard for GERD diagnosis. For these reasons, there are exaggerations in the diagnosis and treatment of this disease, which need to be corrected.

da Silva N.A.P.,Centro Universitario Of Brasilia | Frizzas M.R.,University of Brasilia | de Oliveira C.M.,Embrapa Cerrados
Revista Brasileira de Entomologia | Year: 2011

Seasonality in insect abundance in the "Cerrado" of Goiás State, Brazil. Many studies have provided evidence that tropical insects undergo seasonal changes in abundance and that this is partly due to alternation between the dry and rainy seasons. In the Brazilian "Cerrado" (savannah), this season alternation is particularly evident. The purpose of this work was to study the seasonal abundance of insects in a "Cerrado" area in the municipality of Pirenópolis, Goiás State, Brazil. The insects were captured fortnightly using a light trap between September 2005 and August 2006. The insects collected were separated at the order level and counted. Faunistic analysis was performed to select the predominant insect orders, a multiple linear regression to examine the relation between climatic variables (temperature and precipitation) with the abundance of insects and a circular distribution analysis to evaluate the existence of seasonality in the abundance of insect orders. A total of 34,741 insect specimens were captured, belonging to 19 orders. The orders with the greatest number of specimens were Hymenoptera (8,022), Coleoptera (6,680), Diptera (6,394), Lepidoptera (6,223), Isoptera (2,272), Hemiptera (2,240) and Trichoptera (1,967), which represent 97.3% of all the specimens collected. All the orders, except for Diptera, Isoptera and Trichoptera, showed a relationship with the climate variables (temperature), and all the orders, except for Diptera, presented a grouped distribution, with greater abundance in the transition from the end of the dry season (September) to the start of the rainy one (October/November). A discussion about seasonality on the abundance of the insects is presented.

Fernandes A.A.,Centro Universitario Of Brasilia | Freitas F.D.,Centro Universitario Of Brasilia | Ishihara J.Y.,Centro Universitario Of Brasilia
CHILECON 2015 - 2015 IEEE Chilean Conference on Electrical, Electronics Engineering, Information and Communication Technologies, Proceedings of IEEE Chilecon 2015 | Year: 2015

This paper presents an alternative procedure for solution of the linear sub-problem that arises in solving the load flow problem in electric power systems. The procedure aims highlight a solver based on Broyden method which is used to solve iteratively a reordered and preconditioned linear system. To evaluate the performance of the solver, tests are performed on four power system models. The results are confronted with solvers based on the direct method (Gaussian elimination and LU) and the traditional iterative method GMRES. The superior performance of the proposed solver based on Broyden method is demonstrated comparing the CPU time required for each technique. © 2015 IEEE.

Diniz P.,Centro Universitario Of Brasilia | Diniz P.,University of Brasilia | Ramos D.M.,University of Brasilia | Chemin N.,Centro Universitario Of Brasilia | Chemin N.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária
Wilson Journal of Ornithology | Year: 2013

The Coal-crested Finch (Charitospiza eucosma) is a rare, globally near threatened and poorly known species, endemic to the savannas of central Brazil and Bolivia. We investigated this species' breeding biology in the Brazilian savannas between 2008-2010. We found 44 nests of Coal-crested Finches during one and a half breeding seasons. Coal-crested Finches reproduced in two discrete peaks within the rainy season (i.e., bimodal breeding). Nests were cup-shaped and built on trees with a mean height of 2.18 ± 1.34 m (n = 42). Modal clutch size was 2 (range = 1-3). Eggs averaged 16.32 ± 1.16 mm (length; n = 46), 11.30 ± 1.06 mm (width; n = 46) and 1.40 ± 0.14 g (mass; n = 44). Incubation and nestling periods lasted on average 13.4 ± 0.42 days (n = 5) and 12.0 ± 2.63 days (n = 7), respectively. Young (0-4 days old), middle-aged (5-9 days old) and late nestlings (10-13 days old) weighed from 1.25-6.35 g (n = 10), from 5.30-12.65 g (n = 12) and from 9-11.90 g (n = 9), respectively. Estimated nesting success was 20.08% (n = 38). The Coal-crested Finch has similarities (e.g., nest material, clutch size, eggs, nestling period, nestlings and nesting success) and differences (e.g., nest structure, nest sites, incubation period, breeding season) with other Neotropical finches. We suggest that their bimodal breeding season may have evolved in response to two annual peaks of food resource abundance: arthropods followed by grass seeds. © 2013 by the Wilson Ornithological Society.

Charao A.P.S.,Centro Universitario Of Brasilia | Batista M.H.R.E.S.,Regional Asa Sul | Ferreira L.B.,Centro Universitario Of Brasilia
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2012

Introduction: Food security remains to be one of the world's biggest problems and is found to be related to HIV/AIDS. The objective was to examine food insecurity in HIV/AIDS patients from Brasilia, Brazil. Methods: Short version of the Food Security Scale was applied to patients with HIV/AIDS. Results: A total of 103 patients participated (65 HIV+ and 38 with AIDS). Food insecurity was found in 33.8% of HIV+ patients and 36.8% of patients with AIDS. A relation between food insecurity and low educational and social levels was established. Conclusions: Food security should be an important component in HIV/AIDS treatment programs.

Jose S.C.B.R.,Embrapa Recursos Geneticos e Biotecnologia | Salomao A.N.,Embrapa Recursos Geneticos e Biotecnologia | Costa T.S.A.,Embrapa Recursos Geneticos e Biotecnologia | da Silva J.T.T.T.,Centro Universitario Of Brasilia | Curi C.C.S.,Embrapa Recursos Geneticos e Biotecnologia
Revista Brasileira de Sementes | Year: 2010

The significant progress in Brazilian agricultural production has been due its capacity to incorporate and use genetic resources. Embrapa Genetic Resources and Biotechnology is the institution responsible for the long-term conservation of the seed germplasm of many crops, stored at -20 °C. Appropriate storage is necessary for correct germplasm management, to ensure the quality of the material stored and minimize the deterioration process. The objectives of this study were to evaluate the effect of seed water content on the tolerance to storage at sub-zero temperatures of -20 °C and -196 °C, to associate the tolerance level with physiological and biochemical aspects and to verify the effect of the pre-humidification of seeds on physiological quality after storage. Seed quality was evaluated by tests of electrical conductivity, first and final count of germination and determination of the peroxide index. Sunflower seeds can be dried to 3.2% of water content in silica gel or in a drying chamber and stored at -20 °C or -196 °C without loss of germination and vigor. Seed deterioration, evaluated by the peroxide index, was lower in seeds stored in NL. The humidification treatment was important for the evaluation of seedlings in the first count of germination test and the electrical conductivity test.

Lima F.M.S.,University of Brasilia | Venceslau G.M.,University of Brasilia | Brasil G.T.,Centro Universitario Of Brasilia
Revista Brasileira de Ensino de Fisica | Year: 2014

In hydrostatics, the Archimedes principle predicts an upward force whenever a body is submerged in a liquid. In contrast to common sense, this physical law is not free of exceptions, as for example when the body touches the container. This is more evident when a rectangular block less dense than the liquid rests on the bottom, with no liquid underneath it, a case in which a downward force is expected, according to a recent work by the first author. In the present work, we describe a simple, low-cost experiment which allows the detection of such force. This counterintuitive result shows the inadequacy of Archimedes' principle for treating "contact" cases. © Sociedade Brasileira de Física.

Ramirez P.E.,Central American Business University | Mariano A.M.,Centro Universitario Of Brasilia
Informacion Tecnologica | Year: 2014

This study analyzes the scientific production in the field of business studies in Chile and Brazil. The methodology is based on scientometric tools, using as sources 7955 papers published in Scopus indexed journals between 2004 and 2013. In summary, the results indicate that although in both countries the scientific production has significantly increased, a reduction of the impact of these articles is detected. In addition, there are differences between Chile and Brazil associated to cooperation with other countries, the variety of journals where studies are published, and the structure of the ranking of the institutions that publish. The main conclusions indicate that research in this area is carried out in universities, cooperation between countries is significant in this scientific production, and dissemination is carried out mainly through regional journals. © 2014, Centro de Informacion Tecnologica. All rights reserved.

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