110 research outputs found

    Study on the model to determine riverbed scour and the influence of bridge construction on riverbed deformation

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    River geomorphic features can dramatically change over time. It is undoubtedly the most dynamic geomorphic system that engineers have to manage in the design and maintenance of bridges. In the event of major floods, significant changes can take place within a short period of time. In contrast to rivers which are dynamic, bridges generally do not move except in accordance with planned structural deflections caused by anticipated static and dynamic loading. The stability and safety of bridges can be jeopardized in several ways as a result of riverbed channel changes, being the removal of bed material in the vicinity of bridge foundations (as a result of local scouring phenomenon) the most common cause of several bridge collapses worldwide. Due to the complex nature of the fluid flow, there are still many uncertainties that affect the design process of bridge piers. Therefore, different approaches have been used comprising empirical formulations, experimental studies, sophisticated numerical simulations, and, whenever possible, underwater survey activities as a manner of monitoring the scouring process at bridge piers founded in alluvial/movable riverbeds. Therefore, the present study analyses the local scour phenomenon around the bridge piers of an intervened Vietnam bridge – Doan Hung bridge, by using different monitoring inspection surveys over a period of time. Research results will clarify the influence of bridge piers’ design and construction on movable beds, indicate future predictions to monitor and control the severity of the scouring process, and propose management measures for the safety of bridge infrastructures.This work was supported by the Project PTDC-ECI-EGC-5177-2020 (POSEIDON project), funded by national funds through the FCT – Portuguese Foundation for Science and Technology. This work was partly financed by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020 and Vingroup and supported by Innovation Foundation (VINIF) under project code VINIF.2021.DA00192. Tran Quang Minh was supported by the doctoral Grant reference PRT/BD/154268/2022 financed by Portuguese Foundation for Science and Technology (FCT), under MIT Portugal Program (2022 MPP2030-FCT). Hélder S. Sousa acknowledges the funding by FCT through the Scientific Employment Stimulus - 4th Edition

    Genetic Characterization of Melipona subnitida Stingless Bee in Brazilian Northeast

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    The study of M. subnitida, stingless bee well adapted to extreme environmental conditions, is noteworthy once the Northeastern Brazil faces climate changing predictions in which the precipitation rates are expected to decrease, and the average of temperatures to increase. The well-studied populations are limited to the Caatinga biome, where the species was considered endemic. However, the occurrence of this species has been reported in contrasting environments from arid region, such as mangrove and sandbanks in Maranhão state. Our primary goal was to characterize samples from these different environments and compare them with previously studied populations. We identified a unique mitochondrial haplotype per region. The haplotype found in Lençóis Maranhenses National Park was exclusive from this location and differed regarding the amino acid sequence when compared to the literature presented haplotypes from Caatinga, which might be related with different evolutionary processes in the distinct environments, though further studies are needed to confirm. Melipona subnitida is highly adapted to extreme environmental conditions and can survive under long drought periods, since during water and resource scarcity, the bees reduce the colony size to a minimum number of brood and workers. Thus, the species maintains only essential tasks for the nest, being an important mechanism to save the resources stored during the bloom of rainy periods (Maia-Silva et al., 2014; 2015). Assuming the climate change predictions for Northeastern Brazil (Marengo et al., 2011) in the semi-arid region, where average reductions in precipitation rates of up to 40–50% are expected (PBMC, 2013), the study bees resistant to these conditions, such as M. subnitida, is noteworthy. Considering the importance of this species regarding resistance to extreme climatic conditions, distributional modelin

    X-linked Adrenal Hypoplasia Congenita: report of two families and a new NR0B1 mutation

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    Background: X-linked Adrenal Hypoplasia Congenita (X-linked AHC) tipically manifests as adrenal insufficiency in a bimodal clinical presentation (5–60 days and 2–13 years) and, at pubertal age, hypogonadotropic hypogonadism (HH) in males. It is caused by mutations in NR0B1 (present in Xp21.2), a gene with a critical role in the development of adrenals and hypothalamic-pituitary-gonadal (HPG) axis. It represents ~1% of all causes of primary adrenal insufficiency under age 18. We present two kindreds with NR0B1 mutations, one with a previously unreported mutation. Clinical case - family A: The proband presented with adrenal crisis at day 18 of life. Family history was relevant for an uncle death as a newborn. Hormonal assays revealed elevated ACTH (34,5 pmol/L, reference: T, leading to a premature stop codon, p.Lys362*, in exon 1. His mother and sister were both asymptomatic carriers for this mutation. This mutation, not described previously, leads probably to a non-functional truncated protein. Clinical case - family B: Kindred B had two males who presented with adrenal crisis at the newborn age (proband: 14 days; brother: 16 days). At 6 months of age, the proband had elevated ACTH (193.2 pmol/L, reference: G; p.Tyr81*, in exon 1, present in the two affected males. His mother and one sister were also asymptomatic carriers. Conclusion: Our kindreds highlights the clinical aspects of the rare X-linked AHC and its challenging differential diagnosis. The diagnosis was based on …. Completar … and an apparently X-linked mode of inheritance. Molecular analysis of the NR0B1 gene allowed the identification of the molecular defect in both families. Two different nonsense mutation in exon 1 were identified, giving rise most probably to truncated non-functional proteins, confirming the disease severity or the clinical phenotype of the affected boys. Mutation identification was relevant for genetic counseling of the parents, as well as for the patient’s sisters

    Corrosion Grade on Anchor Rods of Guyed Transmission Towers Applying Machine Committee / Grau de Corrosão em Hastes de Âncora de Torres de Transmissão Guiadas Comitê de Aplicação de Máquinas

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    The use of guyed structures in electric power transmission lines is a growing practice because of their cost efficiency. However, the anchor systems are subject to corrosion, which can lead to their rupture and loss of tower support. Monitoring the evolution of the corrosion of the anchor rods by visual inspection is a destructive and costly method; therefore, there is considerable interest in developing methods and tools that are capable of generating a maintenance diagnosis of the system. This work aimed to propose a classification tool for guyed towers in terms of the corrosion degree by a machine committee with neural networks and applied it to the Paraiso-Açu line located in Rio Grande do Norte in Brazil. Thirty-eight samples were collected and 33 variables related to the soil corrosion along the line were analyzed. The targets for training the networks were obtained from the inspection of anchor rods taken from the field. A simplification of the problem's dimension was proposed by principal component analysis, describing the phenomenon with 6 variables instead of 33, simplifying the practical application by massively reducing the requirements for data sampling in the field. Several network typologies were trained and the best ones in terms of their generalist and specialist capacities were combined in a machine committee for the final proposal of this work. The classification obtained by the application of the committee for 10 towers was compared with the classification from non-destructive impulse reflectometry tests and showed an 80% correlation

    Resistividade em solos: efeito dos índices físicos e condições de análise / Soil resistivity: phisical indexes and analysis conditions influence

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    A resistividade elétrica é um parâmetro amplamente utilizado na avaliação da corrosividade dos solos. Entretanto, algumas metodologias de análise em laboratório têm divergência nos procedimentos e resultados obtidos, o que pode impactar na correta avaliação da propriedade e sua consequente correlação com a resistência à corrosão. Neste estudo foi realizado uma revisão dos ensaios de resistividade de solo propostos pelos procedimentos adotados pelas normas ABNT NBR 16254-1:2014 (Anexo C), ASTM G-187-15 e ASTM G-187-15 modificada pela adoção de cálculos dos índices físicos para obtenção do grau de saturação da amostra de solo. A avaliação dos resultados indicou que o os procedimentos realizados pela norma ASTM-G187-15 e pelo mesmo procedimento modificado, adotando os índices físicos foram compatíveis. Já o ensaio realizado pela norma ABNT NBR 16254-1:2014 (Anexo C) não teve resultados satisfatórios

    A commercial blend of macroalgae and microalgae promotes digestibility, growth performance, and muscle nutritional value of European seabass (Dicentrarchus labrax L.) juveniles

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    Algae can leverage aquaculture sustainability and improve the nutritional and functional value of fish for human consumption, but may pose challenges to carnivorous fish. This study aimed to evaluate the potential of a commercial blend of macroalgae (Ulva sp. and Gracilaria gracilis) and microalgae (Chlorella vulgaris and Nannochloropsis oceanica) in a plant-based diet up to 6% (dry matter basis) on digestibility, gut integrity, nutrient utilization, growth performance, and muscle nutritional value of European seabass juveniles. Fish (11.3 ± 2.70 g) were fed with isoproteic, isolipidic, and isoenergetic diets: (i) a commercial-type plant-based diet with moderate fishmeal (125 g kg−1 DM basis) and without algae blend (control diet; Algae0), (ii) the control diet with 2% algae blend (Algae2), (iii) the control diet with 4% algae blend (Algae4), and (iv) the control diet with 6% algae blend (Algae6) for 12 weeks. The digestibility of experimental diets was assessed in a parallel study after 20 days. Results showed that most nutrients and energy apparent digestibility coefficients were promoted by algae blend supplementation, with a concomitant increase in lipid and energy retention efficiencies. Growth performance was significantly promoted by the algae blend, the final body weight of fish fed Algae6 being 70% higher than that of fish fed Algae0 after 12 weeks, reflecting up to 20% higher feed intake of algae-fed fish and the enhanced anterior intestinal absorption area (up to 45%). Whole-body and muscle lipid contents were increased with dietary algae supplementation levels by up to 1.79 and 1.74 folds in Algae 6 compared to Algae0, respectively. Even though the proportion of polyunsaturated fatty acids was reduced, the content of EPA and DHA in the muscle of algae-fed fish increased by nearly 43% compared to Algae0. The skin and filet color of juvenile European seabass were significantly affected by the dietary inclusion of the algae blend, but changes were small in the case of muscle, meeting the preference of consumers. Overall results highlight the beneficial effects of the commercial algae blend (Algaessence®) supplementation in plant-based diets for European seabass juveniles, but feeding trials up to commercial-size fish are needed to fully assess its potential

    A complex scenario of tuberculosis transmission is revealed through genetic and epidemiological surveys in Porto

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    Tuberculosis (TB) incidence is decreasing worldwide and eradication is becoming plausible. In low-incidence countries, intervention on migrant populations is considered one of the most important strategies for elimination. However, such measures are inappropriate in European areas where TB is largely endemic, such as Porto in Portugal. We aim to understand transmission chains in Porto through a genetic characterization of Mycobacterium tuberculosis strains and through a detailed epidemiological evaluation of cases.This work was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER), and supported by contributions from Iceland, Liechtenstein and Norway through the European Economic Area Grants under the Public Health Initiative programme, (PT06, Project 000138DT1). TR is supported by the Portuguese Foundation for Science and Technology (FCT) through a post-doctoral grant (SFRH/BPD/108126/2015)info:eu-repo/semantics/publishedVersio

    A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing

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    Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe
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