979 research outputs found
Hemodinâmica em aneurisma cerebral: estudo numérico
Neste trabalho estudaram-se escoamentos sanguíneos laminares em estado estacionário num aneurisma cerebral obtido por imagiologia médica. Nas simulações realizadas o sangue foi considerado um fluido Newtoniano, assim como não-Newtoniano, tendo-se verificado que, para as condições de operação estabelecidas, as propriedades não-Newtonianas não influenciaram propriedades como a tensão de corte na parede e as quedas de pressão.info:eu-repo/semantics/publishedVersio
Hemodinâmica ema aneurisma cerebral: estudo numérico
Neste trabalho estudaram-se escoamentos sanguíneos laminares em estado estacionário num aneurisma cerebral obtido por imagiologia médica. Com este trabalho pretende dar-se um contributo para o melhor entendimento das propriedades dos escoamentos sanguíneos no interior de aneurismas cerebrais, tais como: velocidade, pressão e tensão de corte na parede. As equações governativas foram resolvidas recorrendo ao software de dinâmica de fluidos computacional ANSYS-FLUENT®, sendo consideradas duas equações constitutivas distintas para descrever a reologia do sangue – modelo de Carreau e modelo Newtoniano. Desta forma foi possível analisar o impacto das características não-Newtonianas do sangue nas propriedades dos escoamentos, tendo-se verificado que, para as condições de operação estabelecidas, estas não influenciam as propriedades do escoamento referidas anteriormente.info:eu-repo/semantics/publishedVersio
Sward Structural Characteristics of Perennial Peanut Genotypes as Affected by Harvest Frequency
Despite the high potential of tropical forage species, herbage production, nutritive value and animal productivity in Brazilian livestock production systems are lower than what can be obtained from both a biological and operational point of view (Pedreira and Mello 2000, Da Silva and Sbrissia 2000). Even with these limitations, the livestock industry is often able to sustain high productivity levels (animal product per hectare) by using good animal genetics and supplementation. Reducing production costs, however, will likely depend on the identification and incorporation of a high-quality forage resource, in terms of both improving diet quality of grazing animals and sustaining pasture soil productivity. The search for economically viable and sustainable forage production alternatives has been the subject of a great deal of research in many parts of the world. Among the alternatives explored, the diversification of pastures by the introduction of forage legumes in traditional production systems has been suggested, mainly to improve soil chemical characteristics (increased nitrogen levels) and improve forage quality (Perez 2004, Valentim and Andrade 2004). Promising legume germplasm is available in the tropics, but before these materials are incorporated into commercial systems, they need to be evaluated for adaptation, productivity and persistence in specific micro-environments. In addition, interactions involving grazing management strategies and genotypes should be described and explained, so that their agronomic potential can be explored.
The aim of this study was to characterise sward structure of 4 perennial peanut genotypes subjected to 2 harvest management strategies, in south-eastern Brazil
An Overview of Sustainability Assessment Frameworks in Agriculture
Recent research established a link between environmental alterations due to agriculture intensification, social damage and the loss of economic growth. Thus, the integration of environmental and social dimensions is key for economic development. In recent years, several frameworks have been proposed to assess the overall sustainability of farms. Nevertheless, the myriad of existing frameworks and the variety of indicators result in difficulties in selecting the most appropriate framework for study site application. This manuscript aims to: (i) understand the criteria to select appropriate frameworks and summarize the range of those being used to assess sustainability; (ii) identify the available frameworks to assess agricultural sustainability; and (iii) analyze the strengths, weaknesses and applicability of each framework. Six frameworks, namely SAFA, RISE, MASC, LADA, SMART and public goods (PG), were identified. Results show that SMART is the framework that considers, in a balanced way, the environmental, sociocultural and economic dimensions of sustainability, whereas others focused on the environmental (RISE), environmental and economic (PG) and sociocultural (SAFA) dimension. However, depending on the scale assessment, sector of application and the sustainability completeness intended, all frameworks are suitable for the assessment. We present a decision tree to help future users understand the best option for their objective
The Influence of Research and Innovation Strategies for Smart Specialization (RIS3) on University-Industry Collaboration
This study aims to understand better research and innovation strategies for smart specialization (RIS3) and assess how they influence university-industry (U-I) collaboration empirically. Primary data were collected from a focus group consisting of representatives of universities and government entities from Portugal and Spain. Secondary European Union (EU) data on the application of smart specialization measures and the innovation in these two countries were also included. The results reveal difficulties in implementing RIS3, resulting in decreased investment in research and innovation in all production sectors. Evidence also pointed to the negative impact of smart specialization measures on U-I collaboration and, consequently, on the respective knowledge transfer.info:eu-repo/semantics/publishedVersio
Valorization of watermelon fruit (Citrullus lanatus) byproducts: phytochemical and biofunctional properties with emphasis on recent trends and advances
Watermelon (Citrullus lanatus) a fruit crop, is an herbaceous creeping plant belonging to the family
Cucurbitaceae. It is a tropical plant, mainly propagated by seeds and thrives best in warm areas. While the
fruit pulp is consumed, seeds are often discarded. The continuously growing global market for the main
tropical fruits is currently estimated at 85 million tons, of which approximately half is lost or wasted
throughout the whole processing chain. Developing novel processes for the conversion of these byproducts
into value‐added products could provide a viable way to manage this waste problem, aiming at the same
time to create a sustainable economic growth within a bio‐economy perspective. Given the ever‐increasing
concern about sustainability, complete valorization through a bio‐refinery approach, that is, zero waste
concepts is therefore most important. This paper aims to report the status on the valorization of tropical
fruit byproducts, more specifically in watermelon seeds and their content in bioactive compounds, such as
phenolic acids, flavonoids, carotenoids, alkaloids. Moreover, the bioactivity of the different types of
phytochemicals and their possible application as a resource for different sectors (food, pharmaceutical, and
environmental sciences) is discussed. Consequently, this review presents the concepts of tropical fruit
byproducts recovery, and the potential applications of the isolated fractions.info:eu-repo/semantics/publishedVersio
An historical survey of the botanical research done at the Lousã mountain system (Portugal)
This work is intended to be the first contribution to a checklist of the vascular plant flora of the Lousã mountain system. Only bibliographic records are included, specially the ones extracted from studies dating from the 19th century, for a future comparison with the present diversity. A total of 225 taxa where recorded, of which at least 86 % can still actually be found in the study area, according with our field observations. However, at least four are most probably extinct, because no population are actually known.Con este trabajo se publica una primera contribución para el catálogo florístico de la Sierra de Lousã. Se incluyen sólo citas bibliográficas,especialmente las extraídas de estudios de antiguos botánicos, para una comparación futura con la biodiversidad actual. Se encontraron 225 citas correspondientes a taxones de la flora vascular de las cuales por lo menos un 86 % están confirmadas en base a nuestras primeras observaciones de campo. Por lo menos cuatro de los taxones citados están, muy probablemente, extinguidos porque no se conocen poblaciones actuales
Blood flow in cylindrical stenosed channel – numerical approach
Arthrosclerosis means literally “arteries hardening”. However, arthrosclerosis it is a generic term that is related with three patterns of vascular diseases, which have the hardening and loss of elasticity of the arteries walls as a common factor [1]. The dominant pattern is atherosclerosis, characterized by the formation of atheroma, which is comprised by fibrous plaques that generally exhibit a centre rich in lipids.
In the present work, the flow of blood in a cylindrical channel, containing an atheroma at the walls, has been numerically studied using the finite-element software package POLYFLOW®. In the simulations, blood was considered an incompressible homogenous fluid and the flow regime was the laminar regime. The rheology of the mentioned fluid was described by distinct constitutive equations [2] - constant viscosity, power-law model and Carreau model. The local behaviour of properties such as pressure, interstitial velocities, shear rate and shear stress was explored in the present investigation. The local behaviour of these properties can help to understand the formation and detachment of thrombi
Genome scale metabolic network reconstruction of pathogen – Enterococcus faecalis
Enterococcus faecalis is a Gram-positive bacterium that
is getting more attention due to its “two-face” behavior.
This natural inhabitant of the gastrointestinal
mammalian tract is also an opportunist pathogen
responsible for urinary tract infections, nosocomial
infections, bacteremia and infective endocarditis (1).
Since the metabolic reconstruction of Haemophilus
influenzae was published in 1999 (2), many other
researchers have focused their attention into the
possibilities that the new era of genome-scale metabolic
models could bring to the scientific scene, both in
prokaryotic and eukaryotic organisms
Metabolic network reconstruction of the central carbon metabolism of Enterococcus faecalis
The profound advance in experimental high throughput techniques (generally referred to as
“omics techniques”) has enabled the analysis of a large number of components within a living
cell. The vast amount of data obtained from the different “omics” (genomics, proteomics,
fluxomics, metabolomics, transcriptomics) demands the use of bioinformatics tools. These
methods comprise the development of comparative tools and maintenance of databases for the
analysis of genomics data, in addition to the construction of models for the analysis and
integration of data in a system-wide approach. Enterococcus faecalis is a Gram-positive
bacterium that is getting more attention due to its “two-face” behavior. This natural inhabitant of
the mammalian gastrointestinal tract is also an opportunist pathogen responsible for urinary tract
infections, nosocomial infections, bacteremia and infective endocarditis. Besides, its intrinsic
physiological properties such as inherent antibiotic resistance and exceptional ability to adapt to
harsh conditions provide this organism with an enormous advantage in the infection processes.
Here, we propose to reconstruct the genome scale metabolic network of the central carbon
metabolism of Enterococcus faecalis using genome sequencing information available on
different databases as well as proteomics and metabolomics data. The first metabolic model
generated for this bacterium will allow correlating metabolite levels and fluxes which enables
identification of key control points in its metabolism. As it has been previously shown for other
organisms, the metabolic network reconstruction may serve as a valuable tool to predict the
phenotypic behaviour under various genetic and environmental conditions
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