6,279 research outputs found
Biomarkers: a strategic tool in the assessment of environmental quality of coastal waters
Ecosystems are under the pressure of complex mixtures of contaminants whose effects are not always simple to assess. Biomarkers, acting as early warning signals of the presence of potentially toxic xenobiotics, are useful tools for assessing either exposure to, or the effects of these compounds providing information about the toxicant bioavailability. In fact, it has been argued that a full understanding of ecotoxicological processes must consider an integrated multi-level approach, in which molecular impact is related with higher-order biological consequences at the individual, population and community levels. Monitoring programs should make use of this tool to link contaminants and ecological responses fulfilling strategies like those launched by OSPAR (Commissions of Oslo and Paris) Convention on the protection of the marine environment of the North-East Atlantic and the International Council for the Exploration of the Sea (ICES). An overview of the work done in the past few years using biomarkers as in situ tools for pollution assessment in Portuguese coastal waters is presented as a contribution to the set up of a biomonitoring program for the Portuguese coastal zone. Considering the data set available the biomonitoring proposal should include the analysis of biomarkers and effects at individual levels. The aim of the program will include a spatial and temporal characterization of the biomarkers acetyl-cholinesterase, metallothioneins, DNA damage, adenylate energy charge and scope-for-growth levels. The investigation of the spatial variation of biomarkers is crucial to define sites for long term monitoring, which will be integrated with a chemical monitoring program. This framework will be a major contribution to the implementation of a national database for the use of biomarkers along the Portuguese coast.info:eu-repo/semantics/publishedVersio
Predicting calcium in grape must and base wine by FT-NIR spectroscopy
Calcium content in sparkling wines may not exceed 80 mg/L due to the risk of aggregation with alginate capsules.
The high calcium content usually found in wine and must emphasizes the need to develop alternative and
appropriate techniques faster and cleaner than atomic absorption spectrometry (AAS). To obtain a robust model
to predict calcium content, FT-NIR spectroscopy was used in 98 base white wine samples and 60 must samples
from an Alentejo winery. The reference method for calcium determination was AAS technique, with a dry ashing
sample procedure, as a prior treatment.
Results confirmed the ability of FT-NIR as an alternative technique to AAS, to predict calcium content in
grape must and base wine. Advance knowledge of the calcium content in the grape must will help avoid obtaining
a mixture of musts with a high calcium content in the same container
A reserva legal nas cooperativas: um estudo de caso de uma cooperativa centenária portuense
O objetivo da presente comunicação consiste em refletir sobre as principais diferenças
entre o tratamento jurídico e contabilístico da reserva legal nas cooperativas e nas sociedades
comerciais. Assim, partindo de uma análise crítica do regime previsto no Código Cooperativo
Português, e tendo por referência os documentos contabilísticos da Cooperativa dos Pedreiros,
esta comunicação procura responder a questões pertinentes no que concerne à constituição e
utilização da reserva legal e à sua finalidade quer durante a vida das cooperativas quer no
momento da dissolução e liquidação do seu património.
Os resultados do estudo confirmam que a reserva legal nas cooperativas tem um regime
jurídico diferente face ao das sociedades comerciais, nomeadamente quanto ao destino da
reserva legal, que nas cooperativas se circunscreve à cobertura de perdas, bem como a sua
irrepartibilidade.
Tendo em conta o caráter variável do capital social cooperativo, a reserva legal apresentase
como o recurso financeiro de melhor qualidade nas cooperativas. Impõe-se, no entanto,
uma alteração ao normativo jurídico português aplicável às cooperativas quanto a aspetos
particulares do regime jurídico das cooperativas, destacando-se a necessidade do
estabelecimento de uma hierarquia entre as diferentes reservas, no sentido de que, para efeitos
de cobertura de prejuízos, a reserva legal só seja movimentada depois de esgotadas as outras
reservas
Oscillatory behaviour in functional differential systems of neutral type
AbstractIn this paper are obtained several criteria for oscillations of a class of autonomous functional differential systems of neutral type
Supplier selection and procurement in SMEs: Insights from the literature on key criteria and purchasing strategies
Effective strategic purchasing and supplier selection in companies provides businesses with leverage in acquiring goods and services. Thus, companies are in a better position to negotiate prices, discounts, delivery times and logistic channels. Also, strategic purchasing allows for performing a risk assessment to ensure the company's profitability. This research aimed to identify the key currently deliberated by SMEs for supplier selection, considering such purchasing strategies as (1) cost reduction, (2) risk management, (3) global sourcing, (4) total quality management, (5) sustainable management and (6) supplier management. Also, it aimed to identify the emerging issues related to purchasing strategies. This research work performed a content analysis following a literature review. The Scopus indexation database was selected to conduct the document search. After the refinement process, based on 59 analysed documents, bibliometric assessment tools were applied to identify the key criteria for supplier selection. The TOP6 highest ranked criteria, which corresponds to 80 % of the most referred criteria, include: (1) the quality of goods; (2) compliance with the delivery times; (3) price/cost; (4) supplier reputation and/or market positioning; (5) geographical location; and (6) supplier performance history. The goal of strategic purchasing is to support the companies in achieving long-term goals through its integration into the company's strategic planning process. It should be identified by the managers as an important resource. Several factors elevate the importance of strategic purchasing, namely, environmental protection, technology advances related to logistics 4.0, and risk assessment related to global sourcing and sustainability. The present research is in line with the findings of the referred literature, i.e., the application of prioritised criteria for the procurement and supplier selection operations in the industrial context, aiming to reduce lead times and logistic costs. The criteria must be aligned w- (undefined
Purification, characterization and clinical applications of therapeutic fungal enzymes
This book chapter presents an overview of therapeutic fungal enzymes and their developments in biopharmaceuticals for the treatment of several diseases, clinical applications and investigation. Enzymes are biocatalysts of many reactions with widespread use in the pharmaceutical industry and medicine. Due to their high specificity, greater affinity, and high catalytic efficiency, enzymes have been widely used for therapeutic purposes. More specifically, therapeutic enzymes are being used in the treatment of several diseases, such as leukemia, cancer, pancreatic disorders, etc. For instance, L-asparaginase, which presents antineoplastic properties, has been used for the treatment of leukemia, namely acute lymphoblastic leukemia. Nowadays, more than 50% of the enzymes are produced by fungal sources, including the therapeutic enzymes, due to the advantages of being an economically feasible and consistent process, since it has high yield and is easy for modification and optimization of new therapeutic products. In this book chapter, readers from academies, research institutes and industries will gain useful information and in-deep knowledge on the emerging therapeutic fungal enzymes, their purification processes, characterization and medical applications.publishe
Lipid-free Antigen B subunits from echinococcus granulosus: oligomerization, ligand binding, and membrane interaction properties
Background:
The hydatid disease parasite Echinococcus granulosus has a restricted lipid metabolism, and needs to harvest essential lipids from the host. Antigen B (EgAgB), an abundant lipoprotein of the larval stage (hydatid cyst), is thought to be important in lipid storage and transport. It contains a wide variety of lipid classes, from highly hydrophobic compounds to phospholipids. Its protein component belongs to the cestode-specific Hydrophobic Ligand Binding Protein family, which includes five 8-kDa isoforms encoded by a multigene family (EgAgB1-EgAgB5). How lipid and protein components are assembled into EgAgB particles remains unknown. EgAgB apolipoproteins self-associate into large oligomers, but the functional contribution of lipids to oligomerization is uncertain. Furthermore, binding of fatty acids to some EgAgB subunits has been reported, but their ability to bind other lipids and transfer them to acceptor membranes has not been studied.<p></p>
Methodology/Principal Findings:
Lipid-free EgAgB subunits obtained by reverse-phase HPLC were used to analyse their oligomerization, ligand binding and membrane interaction properties. Size exclusion chromatography and cross-linking experiments showed that EgAgB8/2 and EgAgB8/3 can self-associate, suggesting that lipids are not required for oligomerization. Furthermore, using fluorescent probes, both subunits were found to bind fatty acids, but not cholesterol analogues. Analysis of fatty acid transfer to phospholipid vesicles demonstrated that EgAgB8/2 and EgAgB8/3 are potentially capable of transferring fatty acids to membranes, and that the efficiency of transfer is dependent on the surface charge of the vesicles.<p></p>
Conclusions/Significance:
We show that EgAgB apolipoproteins can oligomerize in the absence of lipids, and can bind and transfer fatty acids to phospholipid membranes. Since imported fatty acids are essential for Echinococcus granulosus, these findings provide a mechanism whereby EgAgB could engage in lipid acquisition and/or transport between parasite tissues. These results may therefore indicate vulnerabilities open to targeting by new types of drugs for hydatidosis therapy.<p></p>
Apparent Splitting of S Waves Propagating Through an Isotropic Lowermost Mantle
Observations of shear wave anisotropy are key for understanding the mineralogical structure and flow in the mantle. Several researchers have reported the presence of seismic anisotropy in the lowermost 150–250 km of the mantle (i.e., D urn:x-wiley:jgrb:media:jgrb52636:jgrb52636-math-0002 layer), based on differences in the arrival times of vertically (SV) and horizontally (SH) polarized shear waves. By computing waveforms at a period > 6 s for a wide range of 1‐D and 3‐D Earth structures, we illustrate that a time shift (i.e., apparent splitting) between SV and SH may appear in purely isotropic simulations. This may be misinterpreted as shear wave anisotropy. For near‐surface earthquakes, apparent shear wave splitting can result from the interference of S with the surface reflection sS. For deep earthquakes, apparent splitting can be due to the S wave triplication in D urn:x-wiley:jgrb:media:jgrb52636:jgrb52636-math-0003, reflections off discontinuities in the upper mantle, and 3‐D heterogeneity. The wave effects due to anomalous isotropic structure may not be easily distinguished from purely anisotropic effects if the analysis does not involve full waveform simulations
Mucosal Immunity, Stress, Cognition and Functional Fitness in Sedentary and Active Elderly Men
Physical activity in the elderly has been shown to have positive effects on several chronic diseases and to improve immunity, mental health and cognition. Chronic stress as also been shown to have immuno-suppressive effects and to accelerate immunosenescence. Recently it as also been found that different types of exercise may affect cognition and dementia risk to different extents.
This cross-sectional study compared a group of 16 sedentary men with a mean age of 74,5+10,17 years old and a group of 17 men engaged in moderate regular exercise, mean age 69,99+6,36 years old, and aimed to identifying markers involved in maintaining immune and mental health in the elderly. Immune and physiological markers of stress (salivary IgA, CRP, cortisol, alpha-amylase, testosterone and DHEA), psychological variables (perceived stress, self-esteem, physical self, satisfaction with life) and functional fitness (using the Rikli and Jones test battery) were evaluated. A smaller sample of subjects (8 sedentary and 10 active) was also evaluated for cognitive function using the Vienna Test System Software (Schuhfried, Austria). Four different tests were used: evaluation of reaction time to a visual stimulus, evaluation of reaction time to sound, evaluation of different components of cognitive speed and evaluation of complex and multiple reactions to different stimuli. Statistical analysis was performed using the independent samples T-test and the bivariate Pearson’s correlation for the association between variables. For the cognition tests variables the Mann-Whitney and Spearman tests were used.
Results showed that the active group had significantly better results in all components of functional fitness, including upper and lower strength and flexibility, agility and balance as well as aerobic resistance. Saliva levels of CRP and IgA concentration, but not IgA secretion rates, were lower in the active group. In the psychological variables, differences between groups were only found for Physical Self in the Physical Function domain. The active group performed better for cognitive speed and for complex and multiple reactions test. Correlations were found for the navel perimeter and salivary flow rate (r=-0.32, p=0.02) and CRP (r=0.34, p=0.012) and mean reaction time to sound (r=-0.47, p=0.049); for salivary cortisol and total perceived stress (r=0.29, p=0.034). Two components of the cognitive speed test (reaction time to choose and reaction time to visual search) negatively correlated with saliva flow rate (r=-0.64, p=0.003; r=-0.52, p=0.02). Several correlations were also found for aerobic resistance and the complex and multiple reactions test.
Inflammation and cognition were improved in active groups
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