Within-row advection and stomatal conductance of an irrigated crop

The effects of soil water deficit (edaphic stress) and air vapour-pressure-deficit (atmospheric stress) on stomatal conductance of tomato (Lycopersicon esculentum Mill.) were separately analysed for the range of predawn leaf water potential (Ψp) normally observed in an irrigated crop. Three separate experiments under field conditions were used. In this respect, the main experimental results were: (i) noon stomatal conductance (gs) correlated well with Ψp but poorly with leaf water status expressed via noon leaf water potential; (ii) the scattering sometimes obtained in the relationship between Ψp and gs, for high values of Ψp (above -0.4 MPa) can be explained by a preponderant effect of air vapour-pressure-deficit on stomatal behaviour, compared to the effect of soil water deficit; (iii) the reason for the change on leaf-to-air VPD, responsible for the stomatal closure seems to be the clothesline effect i.e. the positive within-row advection from dry inter-row space. The discussion suggests that the slope of the relationship Ψp - gs can change with the soil cover, the size of the plots and their surrounding conditions. What we observed for this crop and irrigation system is extendable to other crops with important dry soil around, to analyse the implications of the air humidity near the leaves on the stomatal behaviour and water fluxes. This hypothesis can also explain opposite tendencies on the transpiration versus evapotranspiration efficiency.Os efeitos do stress edáfico e do stress atmosférico, na condutância estomática de uma cultura em linhas, ocorrem naturalmente de forma simultânea; aqui foram analisados separadamente, em condições naturais. Foram utilizadas três experiências separadas, numa cultura de tomate, na região de Coruche, sendo as duas últimas conduzidas especificamente para averiguar a causa da aparente falta de relação entre condutância estomática cerca do meio-dia solar, gs e potencial foliar de base, Ψp (estado hídrico do solo na zona perizírrica) em condições de stress hídrico moderado (0> Ψp > -0.4 MPa). Os resultados mostraram que: (i) gs correlaciona bem com Ψp e mal com o estado hídrico das folhas expressas pelo seu potencial medido ao meio-dia solar; (ii) a dispersão encontrada entre Ψp e gs, para Ψp >-0.4 MPa é aqui explicada por um efeito preponderante da secura atmosférica, expressa pelo défice de pressão de vapor do ar junto às folhas, no fecho estomático, em relação ao efeito da secura edáfica (expressa por Ψp.); (iii) nesta gama de Ψp, a advecção lateral (massa de ar quente do espaço entre as linhas para as linhas) parece ser a razão principal para as alterações na humidade do ar responsáveis pelo fecho estomático. Sugere-se que o declive da relação Ψp - gs mudará com a cobertura do solo (solo seco ou molhado, mulch, maior densidade de plantas ou outras coberturas verdes), o tamanho das parcelas, e as condições circundantes, estabelecendo efeitos de micro-advecção entre linha e entre-linha combinados com possíveis efeitos oásis ou de ilha, para plantas isoladas ou pequenas parcelas. O que foi observado para esta cultura e sistema de rega pode ser estendido a outras culturas esparsas ou em linhas com solo seco à sua volta (rega localizada: gota-a-gota ou micro-aspersão), analisando-se as implicações das alterações da humidade na vizinhança das folhas no comportamento estomático e fluxos de água. Esta hipótese pode contribuir para analisar as situações em que a eficiência da transpiração se altera no sentido oposto à eficiência da evapotranspiração, e até analisar os impactos de mudanças de clima no uso da água.N/

Evaluation of the effect of irrigation on biometric growth, physiological response and essential oil of Mentha spicata (L.)

A field experiment was performed on spearmint (Mentha spicata L.) under different irrigation regimes in a hilly area of Southern Italy. Objectives of the study include evaluating the physiological and biometrical response of mint from plant establishment up to its complete maturation, as well as the yield composition in essential oil at two different dates. Increasing levels of water stress affected later developing leaves and plant’s water status and net photosynthesis (from the beginning of stress (DAT 63), while affecting negatively the biometric response very soon and significantly from 35 DAT. Photosynthesis limitation played a critical role from DAT 53 on, namely later, in the harvest period (DAT 35–70). Under severe water stress, crop restricted water losses by modulating stomatal closure and, at harvest, showing lowered mesophyll conductance. Irrigation treatments did not affect the concentration of organic compounds, while the yield of essential oils was negatively affected by water stress due to reduced crop growth, in terms of total and leaf biomass, leaf area index (LAI) and crop heightinfo:eu-repo/semantics/publishedVersio

Hydrological approaches to measure or estimate crop water use – A theoretical background

Hydrological methods are used to retrieve actual evapotranspiration (ETa) as an alternative to micrometeorological techniques. This approach consists in performing the mass balance at a well-defined control volume. Despite the apparent theoretical simplicity of these methods, it is very common to witness their incorrect use, due to the lack of consistency in the definition of their terms by different authors, not only in measurements but also and mainly in common estimations for irrigation scheduling. Therefore, this article aims to review the main concepts and basic definitions of the hydrological methods, especially in the context of irrigation applications in climates with dry summer. The main topics addressed consist of: i) Mass balance and control volume; ii) Soil water thresholds for engineering applications; iii) Evapotranspiration or its components as output variables of water balance equation; iv) Applications of the water balance equation using actual evapotranspiration as input variable. This article is meant as a didactic text in the field of irrigation and drainage to support the learning of concepts related to the water balance. It also includes a set of application exercises to improve the comprehension of this subject.N/

Comportamentos (des)adaptados: causa ou efeito da deficiência mental?

p. 59-70As mudanças operadas, ao nível das concepções sobre a deficiência mental, conduziram a uma perspectiva multidimensional, donde o contributo mais significativo, preconizado pelas várias instituições especializadas, se centra no sentido de conferir uma maior relevância ao comportamento adaptativo. Assim, a classificação do atraso mental não assenta somente na valorização do QI, mas consubstancia-se, na funcionalidade do indivíduo perante as exigências ambientais. As limitações existentes no funcionamento de uma criança com deficiência mental acarretam dificuldades na adequação comportamental em contexto social. Deste modo e, visando uma melhoria na sua inclusão social, importa proceder ao estudo dessas limitações, nomeadamente, ao nível cognitivo, pessoal e social, por se considerar que, a adopção de um determinado comportamento, resulta de processos inerentes a estas dimensões. Constatando-se certos défices nestes domínios e, compreendendo a sua natureza, preconizamos uma intervenção ao nível preventivo, com a finalidade de proporcionar competências de modo a promover a aquisição e/ou execução de skills sócio-afectivos e, de remediação, no sentido da eliminação do comportamento desadaptado, tornando possível a inserção social do individuo com deficiência mental. Acredita-se, assim, na possibilidade da educação da criança com deficiência mental, através da adequação de apoios. Esta nova postura, preconizada pelas mais recentes concepções, conduzirá a uma nova visão e respectiva operacionalização. Deste modo, a criança, portadora de deficiência mental, estará em condições de ser incluída de forma plena no seu contexto social envolvente, tornando- a num ser válido e indispensável para a evolução do pensamento e das atitudes da própria sociedade

Trace elements accumulation in the sea lamprey along the major hydrographic basins of Portugal

Trace elements accumulation in the sea lamprey along the major hydrographic basins of Portuga

Indicadores de Qualidade na Prestação de Serviços de Gestão de Resíduos Urbanos – Caso de Estudo

Nos últimos anos, o setor dos serviços dos resíduos sólidos urbanos tem vindo a sofrer grandes desenvolvimentos, estabelecendo-se metas ambiciosas em termos de tratamento de resíduos produzidos. Esta conjuntura tem-se traduzido em operações de recolha e tratamento destes resíduos, cada vez mais exigentes, tanto a nível económico (controlo dos custos), como a nível da procura de um serviço eficiente. Por conseguinte, torna-se necessário avaliar o desempenho das entidades gestoras e a Entidade Reguladora dos Serviços de Águas e Resíduos (ERSAR) tem assumido essa tarefa, sendo os indicadores de desempenho (ID) um bom instrumento de avaliação de qualidade, quer para a entidade reguladora, quer para as entidades gestoras. Este estudo teve por objetivo analisar os ID utilizados pela RESINORTE, S. A. - Unidade de Produção de Lamego e definir alternativas, nomeadamente na vertente operacional, com benefícios evidentes na gestão do serviço, e visando a melhoria da gestão integrada dos resíduos. Pela análise dos ID, houve a necessidade de proceder à sua reestruturação, através quer da exclusão quer da inclusão de indicadores. Globalmente, da análise efetuada constata-se que o sistema apresenta bons níveis de qualidade do serviço, embora haja necessidade de melhoria de alguns ID.In recent years, the solid waste management sector has been growing with ambitious targets in terms of waste treatment. This fact promotes the improvement of the wastes collection and treatment, in an economic approach (cost control) and as a higher demand of an efficient service. Therefore, it is necessary evaluate the management entities performance. The Regulatory Authority for Water and Waste Services (Entidade Reguladora dos Serviços de Águas e Resíduos - ERSAR) has undertaken this task. The performance indicators (Indicadores de desempenho - ID) are an important quality assessment tool for the regulatory authority and for companies’ management. This study intend to evaluate the development of the ID used by RESINORTE, S. A. - production unit of Lamego. It was found that the Resinorte, S. A., between 2010 and 2013, had acceptable ID, comparing with the goals defined by ERSAR, although several improvements are expected to be implemented.info:eu-repo/semantics/publishedVersio

Extended cheese whey fermentation produces a novel casein-derived antibacterial polypeptide that also inhibits gelatinases MMP-2 and MMP-9

Our previous works produced a whey fermentation methodology that yielded antibacterial activity and potential inhibition of matrix metalloproteases (MMP)-2 and -9. Here, we evaluated if these activities were due to fermentation-produced peptides. Prolonged fermentation was carried out in the presence of our specific lactic acid bacteria (LAB) consortium. LAB fermentation yielded a total of 11 polypeptides, which were predominantly produced after 6 days of fermentation. One which was derived from beat casein presented a particularly high antibacterial activity against food pathogenic bacteria and was more effective than standard food disinfectants. This polypeptide was further studied and was also found to be active against several strains of pathogenic bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), in a dose-dependent manner. It also inhibited MMP-2 and MMP-9 whilst reducing HT29 cancer cell migration in vitro. Overall, this novel whey-derived polypeptide presents dual antibacterial and anti-inflammatory activity, revealing a strong potential to be used in functional foods or as a nutraceutical. Its identification and further characterization can open novel perspectives in the field of preventive/curative diets related to gut microbiota, gut inflammation, and cancer prevention, particularly if used in in vivo studiesinfo:eu-repo/semantics/publishedVersio

Exotic fruits as a source of important phytochemicals: improving the traditional use of Rosa canina fruits in Portugal

Several exotic fruits are used in folk medicine as potential sources of healthy compounds. Rosa canina L. (dog rose) fruits and other parts used to be widely consumed in rural areas from Portugal. The present work intends to highlight the presence of bioactive compounds in those different parts, in order to improve their use based on scientific studies. The antioxidant activity was screened through: radical scavenging effects, reducing power, and inhibition of lipid peroxidation in brain homogenates. Phytochemical characterization included determination of sugars by HPLC-RI, fatty acids by GC-FID, tocopherols by HPLC-fluorescence, phenolics, flavonoids, carotenoids, chlorophylls and ascorbic acid, by spectrophotometric techniques. Galls revealed the highest antioxidant potential, ripen hips showed the highest tocopherols and -carotene contents, as also the most adequate n-6/n-3 fatty acids ratios. Unripe hips gave the highest levels of ascorbic acid and petals revealed the highest concentration of sugars. Ethnobotanical studies conducted have mentioned different use-reports for seeds, petals, flowers and galls, as well as for fruits in different stages of maturity and, therefore, the comparison between chemical compounds and antioxidant properties of those different parts is a key-point of the present study. Furthermore, the levels of antioxidants found would make them suitable sources of compounds to be used commercially to retard rancidity in fatty materials in food manufacturing, to reduce the effects of ageing and to help to prevent oxidative-stress related diseases such as cancer and heart disease

A novel way for whey: cheese whey fermentation produces an effective and environmentally-safe alternative to chlorine

Cheese whey has been described as an environmental hazard due to its high organic content. Although it has been suggested that whey can be used as food disinfectant, it continues to pose an environmental problem because it still contains a high organic load. Here, we aimed to develop a low-cost, scalable fermentation protocol to produce a disinfectant from dairy waste that has very little organic content and high levels of lactic acid. Fermentation was achieved with industrial whey from ewe, goat, and cow’s milk, using a specific mesophilic-lactic acid bacteria starter mix over 120 h, which yielded the highest lactic acid production and the lowest lactose content. Antibacterial activity was observed against Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7, plus a total of thirteen other food pathogenic and spoilage strains, and antibacterial activities were determined to be highest after 120 h. We further validated this whey’s application as a disinfectant in shredded lettuce and compared its e cacy to that of chlorine, evaluating microbial quality, texture, color, and sensory perception, pH, and O2 and CO2 determinations. Results showed that not only was microbial quality better when using our whey solution (p < 0.05), but also the quality indicators for whey were statistically similar to those treated with chlorine. Hence, our work validates the use of an industrial waste whey as a low-cost, e cient, and environmentally safe disinfectant, with potential applications for minimally processed foodstu s as an alternative to chlorineinfo:eu-repo/semantics/publishedVersio

The nutritional composition of fennel (Foeniculum vulgare): shoots, leaves, stems and inflorescences

The chemical composition and the nutritional value of different parts of Foeniculum vulgare (fennel): shoots, leaves, stems and inflorescences, were determined. The evaluation of chemical composition included the determination of moisture, total fat, crude protein, ash, carbohydrates, and nutritional value. The composition in individual sugars was determined, being fructose and glucose the most abundant sugars. The analysis of fatty acid composition, allowed the quantification of twenty one fatty acids. Polyunsaturated fatty acids were the main group in all the fennel parts; linoleic acid predominated in shoots, stems and inflorescences, while a-linolenic acid predominated in leaves. The higher levels of u-3 fatty acids found in leaves contributed to its lowest ratio of u-6 to u-3 fatty acids. Also, the lower levels of u-3 fatty acids found in inflorescences contributed to its highest ratio of u-6 to u-3 fatty acids