690 research outputs found
Short-term exposure to elevated CO2 stimulates growth and metabolic responses that alleviate early-stage iron deficiency symptoms in soybean
Elevated CO2 (eCO(2)) increase plant biomass and might lead to nutritional losses. The results showed that eCO(2) under Fe-deficiency stimulates root dry weight from 0.37-0.80 g plant(-1) and shoot dry weight from 0.82-2.10 g plant(-1), without compromising root/shoot ratio. Besides, eCO(2) improved the chlorophyl content of Fe-deficient plants. However, downregulation of photosynthesis, reduction in stomatal conductance and transpiration rate, and an increase in water-use efficiency was observed due to eCO(2). Moreover, under Fe-deficiency, eCO(2) decreased K and Mg in roots, and Mg in leaves, whereas increased P and Zn in roots and leaves. In Fe-sufficient plants, eCO(2) increased K, P, Mn, Zn and Fe in leaves and did not change the concentration in roots. The Fe-deficiency-induced responses in roots, including the increase in FCR activity, and the expression of Fe-uptake genes were stimulated by eCO(2), but were not sufficient to increase Fe concentration in Fe-deficient plants.info:eu-repo/semantics/publishedVersio
Numerical modeling and optimization of an air handling unit
Concerns about the efficiency of Heating, Ventilating, and Air Conditioning systems, including Air Handling Units (AHUs), started in the last century due to the energy crisis. Thenceforth, important improvements on the AHUs performance have emerged. Among the various improvements, the control of the AHUs and the redesign of the fans are the most important ones. Although, with increasingly demanding energy efficiency requirements, other constructive solutions must be investigated. Therefore, the objective of this work is to investigate, using a computational fluid dynamics (CFD) tool, the fluid flow inside an AHU and to analyze different constructive solutions in order to improve the AHU performance. The numerical model provided a reasonable agreement with the experimental results in terms of air flow rate, despite the assumed simplifications. Regarding the constructive solution concept, the CFD results for the two different flow control units (FCUs) showed improvements in terms of fan static pressure rise. Under real conditions, improvements of 15.1% when compared with the case without the FCU were obtained. Nevertheless, it was concluded that the axial component of the air velocity, at the fan exit, can have a determinant impact on the FCU viability. Finally, an improved FCU geometry, with a new body shape, which resulted in an additional improvement of 6.1% in the fan static pressure rise.The second author would like to express his gratitude for the support given by FCT through the Grant SFRH/BD/130588/2017
Effect of the interaction between elevated carbon dioxide and iron limitation on proteomic profiling of soybean
Elevated atmospheric CO2 (eCO2) and iron (Fe) availability are important factors affecting plant growth that may impact the proteomic profile of crop plants. In this study, soybean plants treated under Fe-limited (0.5 mM) and Fe-sufficient (20 mM) conditions were grown at ambient (400 μmol mol−1) and eCO2 (800 μmol mol−1) in hydroponic solutions. Elevated CO2 increased biomass from 2.14 to 3.14 g plant−1 and from 1.18 to 2.91 g plant−1 under Fe-sufficient and Fe-limited conditions, respectively, but did not affect leaf photosynthesis. Sugar concentration increased from 10.92 to 26.17 μmol g FW−1 in roots of Fe-sufficient plants and from 8.75 to 19.89 μmol g FW−1 of Fe-limited plants after exposure to eCO2. In leaves, sugar concentration increased from 33.62 to 52.22 μmol g FW−1 and from 34.80 to 46.70 μmol g FW−1 in Fe-sufficient and Fe-limited conditions, respectively, under eCO2. However, Fe-limitation decreases photosynthesis and biomass. Pathway enrichment analysis showed that cell wall organization, glutathione metabolism, photosynthesis, stress-related proteins, and biosynthesis of secondary compounds changed in root tissues to cope with Fe-stress. Moreover, under eCO2, at sufficient or limited Fe supply, it was shown an increase in the abundance of proteins involved in glycolysis, starch and sucrose metabolism, biosynthesis of plant hormones gibberellins, and decreased levels of protein biosynthesis. Our results revealed that proteins and metabolic pathways related to Fe-limitation changed the effects of eCO2 and negatively impacted soybean production.info:eu-repo/semantics/publishedVersio
Disciplinas de custos: uma análise nos cursos de Ciências Contábeis das IES do sistema ACAFE
A informação de custos, diante de um mercado de competitividade crescente, apresenta-se como uma base importante ao processo decisório, além de implicar novos paradigmas na gestão dos negócios. Desta forma, torna-se relevante o oferecimento de disciplinas de custos no Curso de Ciências Contábeis onde a contabilidade de custos e seu processo de ensino devem direcionar o aluno, a partir do estudo acadêmico, ao processo externo, ou seja, ao mercado tomador do profissional provido de conhecimento contábil.Considerando a relevância das disciplinas de custos no Curso de Ciências Contábeis das Instituições de Ensino Superior (IES), este artigo tem como objetivo verificar as congruências e divergências destas disciplinas ofertadas nos Cursos de Ciências Contábeis das universidades ligadas à Associação Catarinense das Fundações Educacionais (ACAFE). A metodologia da pesquisa consubstancia-se de um estudo exploratório, realizado por meio de levantamento, com abordagem predominantemente qualitativa. Utilizou-se para análise o conteúdo de ementa, a carga horária e a disposição das disciplinas de custos na grade curricular nestas instituições. A técnica estatística empregada foi análise de clusters. Diante deste estudo que teve como objetivo a verificação das congruências e divergências das disciplinas de custos ofertadas nos Cursos de Ciências Contábeis das instituições ligadas à ACAFE, conclui-se que estas instituições estabelecem um agrupamento predominante, mesmo que na análise isolada de algumas variáveis isto não ocorra. Os resultados da pesquisa evidenciam que na variável ementa, o cluster mais representativo apontou 9 instituições, representando o maior grupo com 56,25% do total de instituições pesquisadas. Na variável fase, 10 instituições apresentaram congruência, pois oferecem as disciplinas de custos em períodos semelhantes. Na variável carga horária, 10 instituições apresentam similaridade no oferecimento das disciplinas de custos e análise de custos com 120 h/a. Conclui-se que, num contexto geral, há um acentuado nível de congruência nas disciplinas de custos entre as universidades analisadas, apesar de divergências encontradas na análise isolada de algumas variáveis
Collaborative methodologies in island fishing communities of cape verde
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© 2021 by the authors. Licensee MDPI, Basel, Switzerland.Marine litter has been considered one of the most serious global challenges, requiring urgent action by governmental bodies, especially in African Small Island Developing States (SIDS), where resources and research are limited. In addition to this, waste management and environmental education and ocean literacy programs in schools are scarce, with islands suffering more seriously from these problems. Despite the amount of literature regarding causes and impacts of marine litter, there is still not enough research conducted concerning the public perceptions on both the problem and the potential solutions. This is even more noticeable in African developing countries, where resources and research are scarce. Perception plays a key role for ecosystem management and conservation policies. This study intends to explore the perceptions of local island fishing communities in Cape Verde regarding marine litter, in order to contribute for an improvement of marine ecosystem management and development of conservation policies. To achieve that, two participatory sessions were conducted in two communities in the island of Santiago—Porto Mosquito and Porto Gouveia—where brainstorming and active listening were used to create shared and authentic spaces for dialogue between the members of the community. Results show that the population of both communities were very aware of the marine litter problem. They were able to identify the lack of a proper waste management system in the island and the inappropriate behaviours of the population as the main causes of this problem. Equipment damages and the presence of plastic inside the fish were the most relevant impacts identified by the participants. These findings reinforce previous research on the importance of public engagement and environmental education to contribute to the conservation of marine ecosystems and to build a strong collaborative ocean governance.publishersversionpublishe
Thermal computational model to predict thermal necrosis in bone sarcomas
Sarcomas are heterogeneous tumors that form frombonetissue, connective tissue, cartilaginous tissue,muscle tissue, adipose tissue, peripheral nerves, and blood vessels,usually atits extremities. These tumors occur at any age and in any region of the patient's body.info:eu-repo/semantics/publishedVersio
Preserving the nutritional quality of crop plants under a changing climate: importance and strategies
Background: Global climate is changing more rapidly than ever, threatening plant growth and productivity while exerting considerable direct and indirect effects on the quality and quantity of plant nutrients. Scope: This review focuses on the global impact of climate change on the nutritional value of plant foods. It showcases the existing evidence linking the effects of climate change factors on crop nutrition and the concentration of nutrients in edible plant parts. It focuses on the effect of elevated CO2 (eCO2), elevated temperature (eT), salinity, waterlogging and drought stresses, and what is known regarding their direct and indirect influence on nutrient availability. Furthermore, it provides possible strategies to preserve the nutritional composition of plant foods under changing climates. Conclusions: Climate change has an impact on the accumulation of minerals and protein in crop plants, with eCO2 being the underlying factor of most of the reported changes. The effects are clearly dependent on the type, intensity and duration of the imposed stress, plant genotype and developmental stage. Strong interactions (both positive and negative) can be found between individual climatic factors and soil availability of nitrogen (N), potassium (K), iron (Fe) and phosphorous (P). The development of future interventions to ensure that the world's population has access to plentiful, safe and nutritious food may need to rely on breeding for nutrients under the context of climate change, including legumes in cropping systems, better farm management practices and utilization of microbial inoculants that enhance nutrient availability.info:eu-repo/semantics/publishedVersio
Conjugation of cell-penetrating peptides with poly(Lactic-co-glycolic acid)-polyethylene glycol nanoparticles improves ocular drug delivery
In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)- polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavail- ability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG- peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confrmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flur- biprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory effcacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment effciency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective preven- tion of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen’s egg test-chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery.This work was supported by the Cooperation Research Program CSIC-CITMA and a project (MAT2011-26994) funded by the Spanish Ministry of Science and Technology. AV is a recipient of a PhD grant from the CSIC. The authors thank Nacho Pérez of the IQAC-CSIC for performing the cytotoxicity assays.Peer reviewe
Numerical thermal study in bone tumor lesion
With the evolution of science and new diagnostic technologies, it was possible to observe a continuous improvement in the treatments in general and in the aid of the patients' quality of life. Malignant tumors can be primary or secondary (metastases), with abnormal growth of cells able to invade other types of tissues and organs through systemic dissemination. Sarcomas are rare primary malignancies formed from mesenchymal tissue and often located at the extremities. In this work, the main objective is to evaluate the minimization of the evolution of bone tumor lesion through the injection of bone cement, filling in the space of the lytic tumor lesion. This methodology allows to verify at the adjacent cement – bone tissue interface, an increase in temperature that can control the local growth of bone metastasis. Different computational models, obtained by medical image processing, will be carried out for two analyses (patient younger than 70 years and older than 70 years). The computational model allows a transient thermal analysis using the finite element method. The temperature results may determine the thermal necrosis effect in the bone tumor lesion. Results will be compared using three different bone cements.info:eu-repo/semantics/publishedVersio
Modelos de Maturidade Digital: Um Estudo de Caracterização Baseado na Revisão Sistemática de Literatura
Knowing the characteristics of digital maturity models is fundamental to achieving an effective evaluation of organisations regarding the use of digital technologies. To this end, this article analyses, through a systematic literature review, the approaches used by digital maturity models. 40 models were analysed, and it was noted that the characteristic “dimensions”, responsible for the structuring of the models, varies little or not at all according to the domain of application, hindering flexibility in the use of the models and making a more realistic organisational assessment impossible. Thus, a grouping of the dimensions was prepared, favouring a future investigation toward the development of a collaborative methodology able to better define and prioritise the dimensions according to the organisational domain, thereby providing greater effectiveness in the preparation and application of a digital maturity model, as well as allowing a better vision of the progress of digital transformation.Conhecer as características dos modelos de maturidade digital é fundamental para possibilitar um eficaz processo de avaliação das organizações quanto ao uso das tecnologias digitais. Para tanto, este artigo tem como objetivo analisar, por meio de uma revisão sistemática da literatura, as abordagens utilizadas pelos modelos de maturidade digital. Com o delineamento metodológico, obteve-se a análise de quarenta modelos. Como resultado, percebeu-se que a característica “dimensões”, responsável pela estruturação dos modelos, praticamente não varia de acordo com o domínio de aplicação, dificultando a flexibilidade na utilização dos modelos e impossibilitando uma avaliação organizacional mais realística. Assim, foi elaborado um agrupamento das dimensões, favorecendo uma investigação futura para o desenvolvimento de uma metodologia colaborativa capaz de melhor definir e priorizar as dimensões de acordo com o domínio organizacional, proporcionando maior efetividade na elaboração e aplicação de um modelo de maturidade digital, além de permitir uma melhor avaliação do progresso da transformação digital
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