434 research outputs found

    Dynamic separation on a pitching and surging airfoil as a model for flow over vertical axis wind turbine blades

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    Vertical axis wind turbine (VAWT) blades undergo dynamic separation due to the large angle of attack variation they experience during a turbine rotation. The flow over a single blade was modeled using a sinusoidally pitching and surging airfoil in a constant free stream flow at a mean chord Reynolds number of 10^5. Two-dimensional, time resolved velocity fields were acquired using particle image velocimetry (PIV). Vorticity contours were used to visualize shear layer and vortex activity. A low order model of dynamic separation was developed using Dynamic Mode Decomposition (DMD). A primary and secondary dynamic separation mode were identified as the critical drivers for the unsteady flow field

    Prenatal diagnosis of idic(9)

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    Tetrasomy of the short arm of chromosome 9 is a rare chromosome imbalance that may result from a supernumerary isochromosome 9 with the most recurrent breakpoints being 9p10, 9q12 and 9q13. On ultrasound, it usually presents with intrauterine growth restriction (IUGR), abnormal facial profile and ventriculomegaly. However, few reports establish a correlation between fetal features and the size of isochromosome or the presence of isodicentric 9. We report the clinical case of a 32-year-old pregnant woman, G2P1, underwent amniocentesis at 13 weeks of gestation with fetal increased nuchal translucency (7mm). The fetus also presented IUGR, cystic higroma, generalized subcutaneous edema, cardiac malformations, facial anomalies and fetal death. The karyotype was performed by standard in situ methods. Fluorescence in situ hybridization (FISH) was performed using centromeric probe CEP9. Conventional cytogenetic and FISH analyses revealed a supernumerary chromosome idic(9)(q12) in all cells examined. After counseling the couple opted for termination of pregnancy. The post-mortem analysis revealed a single umbilical arteria, IUGR, cystic higroma, facial dysmorphism with cleft lip and palate, hypertelorism and low set ears. These findings are in accordance with other reports. Nevertheless, the hypertelorism is not commonly described and such an early detection of a cardiac anomaly is uncommon. Additionaly the fetal death occurred early than in the most cases described in literature. Although breakpoint position effect on the severity on the phenotype is not consensual it has proposed that cases presenting with breakpoints on p10, on q12 or on q13 show a similar phenotype. However, cardiac defects seem more frequent on cases in which the abnormality includes 9q material. This work aims to contribute to a better karyotype-phenotype correlation in cases with tetrasomy 9p and isodicentric chromosomes idic(9)

    Compartimentalização e dinâmica de potássio em plantas de milho.

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    A extração de potássio (K) pela cultura do milho é elevada e impacta a fertilidade do solo. O conhecimento da dinâmica de acúmulo e remobilização desse nutriente na planta pode ser importante no estabelecimento de estratégias otimizadas de manejo da adubação e de melhor controle da sua ciclagem em sistemas agrícolas. Objetivou-se caracterizar os compartimentos de acúmulo do K absorvido pelo milho e sua dinâmica entre a fase de formação da espiga e o final do ciclo, sob dois níveis de investimento tecnológico. Foram coletadas plantas no início do enchimento de grãos e após a maturação fisiológica, quantificando-se o teor e acúmulo de K nos componentes da parte aérea. A absorção de K até a fase de enchimento de grãos provoca importante redução da disponibilidade do nutriente no solo nessa época. A maior parte do K presente nas folhas é remobilizado para os grãos ou lavado pela chuva/irrigação no final do ciclo. A exportação na colheita dos grãos corresponde de 31 a 39 % do total acumulado na parte aérea. O colmo, sobretudo o seu terço inferior, é o principal compartimento de armazenamento do K no milho

    Socio-economic characterization of olive groves in a region in the south of Portugal

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    Serpa and Moura region, in the South of Portugal, have important agricultural potential as well as important agricultural resources that can and should be used and developed, in spite of economic and social depression signs reinforced by demographic difficulties that can lead to desertification in some areas. The main farms' Technical-Economic Orientation (TEO) is olives production, to produce olive oil, since this region has excellent conditions for the activity development. Some mobilizations traditionally made in olive groves lead to soil erosion and make the farm vehicles mobility much more difficult, namely those used in cultural operations. The maintenance of a soil cover in the olive grove space between lines is good, both because it favours the vehicles mobility, it promotes the rain water infiltration and, last but not the least, the soil airing. The objective of this work has been to make a socio-economic characterization of a zone of Serpa and Moura Councils in which a project of soil covers under olive trees is being developed. At the same time cultural accounts were made for the different situations under the study - irrigated olive grove with spontaneous vegetation in the space between lines, irrigated olive grove with seeded vegetation in the space between lines, irrigated olive grove with herbicide application in the space between lines, dry olive grove with spontaneous vegetation in the space between lines, dry olive grove with seeded vegetation in the space between lines and dry olive grove with herbicide application in the space between lines. The survey shows farmers in this area are younger then usual, although they don't have a high level of formal education, general or specific in agriculture. Farm areas are usually high, which can be determinant for the proposed technology adoption. Installation and operation costs for the olive grove are higher on the irrigated olive grove, but of course expected productions are also higher. For this production technology profits coming from olives production are higher then the operation costs. However, in the dry olive grove technology costs are always higher then the profits, being profitability only due to subsidies. The importance of soil cover maintenance, in this region, beside the benefits in what concerns erosion, infiltration and soil airing, is also due to its capacity to minimize the risk farmer's face

    Cellulose nanocrystals from fibers of Macauba (Acrocomia Aculeata) and Gravata (Bromelia Balansae) from Brazilian Pantanal.

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    Cellulose nanocrystals (CNC) were obtained from macauba and gravata fibers. Macauba (or Bocaiuva) is a palm tree found throughout most of Brazil and Gravata is an abundant kind of bromeliab with 1-2m long leaves, found in Brazilian Pantanal and Cerrado. The raw fibers of both fibers were mercerized with NaOH solutions and bleached; they were then submitted to acid hydrolysis using H2SO4 at 45 ?C, varying the hydrolysis time from 15 up to 75 min. The fibers were analyzed by X-ray diffraction (XRD), FTIR Spectroscopy, scanning electron microscopy (SEM) and thermal stability by thermogravimetric analysis (TG). XRD patterns did not present changes in the crystal structure of cellulose after mercerization, but it was observed a decrease of hemicellulose and lignin contents, and consequently an increase of cellulose content with the increase of NaOH solution concentration in the mercerization. After acid hydrolysis, the cellulose nanocrystals (CNC) were also analyzed by transmission electron microscopy (TEM) which showed an acicular or rod-like aspect and nanometric dimensions of CNC from both fibers, but the higher values of aspect ratio (L/D) were found on CNC obtained from gravata after 45 min of acid hydrolysis. The mercerization and subsequent bleaching of fibers influenced the crystallinity index and thermal stability of the resulting CNC, but their properties are mainly influenced by the hydrolysis time, i. e., there is an increase in crystallinity and thermal stability up to 45 min of hydrolysis, after this time, both properties decrease, probably due to the cellulose degradation by the sulfuric acid

    Searching for the roots of the first free African American community

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    San Basilio de Palenque is an Afro-descendant community near Cartagena, Colombia, founded in the sixteenth century. The recognition of the historical and cultural importance of Palenque has promoted several studies, namely concerning the African roots of its first inhabitants. To deepen the knowledge of the origin and diversity of the Palenque parental lineages, we analysed a sample of 81 individuals for the entire mtDNA Control Region as well as 92 individuals for 27 Y-STRs and 95 for 51 Y-SNPs. The results confirmed the strong isolation of the Palenque, with some degree of influx of Native American maternal lineages, and a European admixture exclusively mediated by men. Due to the high genetic drift observed, a pairwise FST analysis with available data on African populations proved to be inadequate for determining population affinities. In contrast, when a phylogenetic approach was used, it was possible to infer the phylogeographic origin of some lineages in Palenque. Contradicting previous studies indicating a single African origin, our results evidence parental genetic contributions from widely different African regions.We thank all sample donors for their contribution to this work and all the people who helped with sample collection, namely, Regina Miranda from the Community of San Basilio de Palenque, the personnel of the Benkos Biojó Rural school, and Miguel Obeso from the etnoeducación program. This work was supported by the University of Cartagena and FPIT—Fundación para la promoción de la investigación y la tecnología del Banco de la República, Colombia (FPIT-388) and partially financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the projects “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). FS was supported by Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ (E-26/202.275/2019). LG was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico—CNPq (ref. 306342/2019-7), and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ (CNE-2018). VG was supported by FCT, under the program contract provided in Decree-Law no.57/2016 of August 29. The IPATIMUP integrates the i3S research unit, which is partially supported by the Portuguese Foundation for Science and Technology

    Functional status and impact of the disease in people with COPD according to symptoms’ burden

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    Background: COPD is a heterogeneous disease. Better understanding of its trajectory, especially considering symptoms level, may help improving disease management. We described the evolution of functional status and impact of the disease in people with COPD according to symptoms level. Methods: People with COPD were assessed monthly for 6 months. Participants were grouped by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria in low (GOLD A & C) or high (GOLD B & D) symptom burden, based on the baseline values in the modified medical research council dyspnoea scale. Quadriceps muscle strength (QMS)–handheld dynamometry, 1-minute sit-to-stand test (1STS) and COPD assessment test (CAT) were collected. Differences within/between groups over time were explored with (non-)parametric mixed ANOVAs and Bonferroni-adjusted pairwise comparisons. Results: 87 people (85%♂, 68±9y, FEV1 51±20pp, 54% high symptoms) participated. People with low symptoms presented higher 1STS (p=0.01) and lower CAT (p<0.01). Improvements in 1STS and CAT over time (p<0.01) were found regardless of group allocation (Fig. 1). There were no group*time interaction or other significant differences. Conclusion: The pattern of progression in functional status and impact of the disease seems similar in people with COPD independently of symptoms’ burden, with improvements in CAT and 1STS over time. Reasons for this finding must be explored.publishe
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