Spinach production in cocopeat: effects of soil block number and the number of emitters per styrofoam box on plant growth, nitrate concentration, and antioxidant activity

Currently, the interest in using cocopeat or coir dust alone as a growing medium to produce leafy vegetables has increased. This research aimed to evaluate the effects of soil block number and of the number of emitters per styrofoam box on plant growth, nitrate (NO3-) concentration, and antioxidant activity in spinach (Spinacia oleracea L. 'Manatee') cultivated in cocopeat. The experiment was carried out with four treatments, 8 and 14 soil blocks (160 and 280 plants m‑2) and 4 and 8 emitters per styrofoam box. The crop was irrigated and fertigated daily with a complete nutrient solution. The yield (kg m‑2) was increased significantly with soil block number and with the number of the emitters by styrofoam box, reaching 5.4 kg m‑2 in the treatment with 14 soil blocks (280 plants m‑2) and 8 emitters. Soil block number had no effect on shoot dry weight plant‑1, leaf-blade and petiole nitrate concentration and total phenols content. The increase in the number of emitters per styrofoam box decreased leaf-blade total phenol sand leaf-blade antioxidant activity. Ferric-reducing antioxidant activity (FRAP) values in the leaf-blade treatments with four emitters ranged from 7.3 to 9.7 mg eq. trolox g‑1 FW. The leaf-blade phenols content and FRAP values were ≈8 and 9 times higher than in the petioles, respectively. These results indicate that cocopeat is a very suitable growing medium for spinach production

Effects of Municipal Solid Waste Compost Supplemented with Inorganic Nitrogen on Physicochemical Soil Characteristics, Plant Growth, Nitrate Content, and Antioxidant Activity in Spinach.

In this study, we evaluated the effects of municipal solid waste compost supplemented with inorganic N on the physicochemical properties of soil, plant growth, nitrate concentration, and antioxidant activity in spinach. Experiments were carried out in neutral and acidic soils that were low in organic matter. A fertilized soil was used as a control, while four compost treatments—two compost rates of 35 and 70 t ha−1, supplemented or not with inorganic N (92 kg N ha−1 as Ca (NO3)2)—were applied by fertigation. The addition of compost increased the soil organic matter content and pH in both soils. The compost supplementation with N greatly increased the shoot dry weight and spinach fresh yield by nearly 109%. With the highest compost rate and 43% N applied, the yield increased in both soils, similar to results obtained in fertilized soil (3.8 kg m−2). The combined application of compost and N could replace inorganic P and K fertilization to a significant extent. The compost application at both rates and in both soils considerably decreased shoot Mn concentrations

Comparative Effects of Nitrogen Fertigation and Granular Fertilizer Application on Growth and Availability of Soil Nitrogen during Establishment of Highbush Blueberry

A 2-year study was done to compare the effects of nitrogen (N) fertigation and granular fertilizer application on growth and availability of soil N during establishment of highbush blueberry (Vaccinium corymbosum L. “Bluecrop”). Treatments included four methods of N application (weekly fertigation, split fertigation, and two non-fertigated controls) and four levels of N fertilizer (0, 50, 100, and 150 kg·ha−1 N). Fertigation treatments were irrigated by drip and injected with a liquid urea solution; weekly fertigation was applied once a week from leaf emergence to 60 d prior to the end of the season while split fertigation was applied as a triple-split from April to June. Non-fertigated controls were fertilized with granular ammonium sulfate, also applied as a triple-split, and irrigated by drip or microsprinklers. Weekly fertigation produced the smallest plants among the four fertilizer application methods at 50 kg·ha−1 N during the first year after planting but the largest plants at 150 kg·ha−1 N in both the first and second year. The other application methods required less N to maximize growth but were less responsive than weekly fertigation to additional N fertilizer applications. In fact, 44–50% of the plants died when granular fertilizer was applied at 150 kg·ha−1 N. By comparison, none of the plants died with weekly fertigation. Plant death with granular fertilizer was associated with high ammonium ion concentrations (up to 650 mg·L−1) and electrical conductivity (>3 dS·m−1) in the soil solution. Early results indicate that fertigation may be less efficient (i.e., less plant growth per unit of N applied) at lower N rates than granular fertilizer application but is also safer (i.e., less plant death) and promotes more growth when high amounts of N fertilizer is applied

) Fresh yield and phytochemical accumulation on spinach grown in different coir types

The objective of this study was to evaluate if coir can replace peat as growing media in spinach production in phytonutrient content and antioxidant activity terms. The effects of four commercial substrates peat; and three coir types: cocopeat, coir-crush chips, and coir medium, on growth, chlorophyll a and chlorophyll b, total:carotenoids, flavonoids, anthocyanins, proline, glutathione content, and glutathione reductase activity were evaluated in spinach (Spinacia oleracea L. ‘Manatee’). Soil blocked spinach seedlings (five seedlings per block) were transplanted into styrofoam planting boxes (100-cm long × 25-cm wide × 10-cm high) filled with 14 L of substrate. Each planting box was irrigated daily by drip with a complete nutrient solution. Yield (fresh yield) in cocopeat and coir medium were similar to those obtained in peat. Leaf-blade total chlorophyll was higher in peat than in the other substrates. However, leaf-blade total carotenoids and anthocyanins were not affected by substrate type and leaf-blade flavonoids and total glutathione (GSH+GSSG) contents were higher in plants grown in the different types of coir than in peat. Leaf-blade proline levels in plants grown in different types of coir were similar to that recorded in plants grown in peat ranging from 3.5 to 4.5 mg 100 g-1 FW. The findings of this study indicate that coir could be an alternative to peat but depends on the coir type

A fuzzified systematic adjustment of the robotic Darwinian PSO

The Darwinian Particle Swarm Optimization (DPSO) is an evolutionary algorithm that extends the Particle Swarm Optimization using natural selection to enhance the ability to escape from sub-optimal solutions. An extension of the DPSO to multi-robot applications has been recently proposed and denoted as Robotic Darwinian PSO (RDPSO), benefiting from the dynamical partitioning of the whole population of robots, hence decreasing the amount of required information exchange among robots. This paper further extends the previously proposed algorithm adapting the behavior of robots based on a set of context-based evaluation metrics. Those metrics are then used as inputs of a fuzzy system so as to systematically adjust the RDPSO parameters (i.e., outputs of the fuzzy system), thus improving its convergence rate, susceptibility to obstacles and communication constraints. The adapted RDPSO is evaluated in groups of physical robots, being further explored using larger populations of simulated mobile robots within a larger scenario

Virtualidades do livro-álbum A árvore da escola para a promoção da ecoliteracia

A presente proposta de póster decorre de um trabalho de investigação realizado no âmbito da unidade curricular Discursos, Textos e Estratégias Interpretativas, do 1.º ano do Mestrado em Educação Pré-escolar e Ensino do 1.º Ciclo do Ensino Básico da Universidade do Minho. A análise da obra parte da noção de sequência narrativa (Adam e Revaz, 1997) e de literatura para a infância (Ramos, 2010), para identificar como a narrativa em questão constrói e promove uma visão do mundo onde os seres humanos tomam consciência da sua interação com o meio, em particular com os elementos naturais – e, assim, fomenta a criação de uma visão tendencialmente “ecológica” do mundo, com as suas redes de interação que ultrapassam a mera exploração irrefletida e linear dos “recursos” naturais (Capra, 2002). Dito de outra forma: pretende-se analisar como esta obra pode promover a ecoliteracia dos jovens leitores a que é destinada (Orr, 1998), sem deixar de ser marcada pelo que a define como obra literária. Entende-se aqui “ecoliteracia” como “a capacidade de os cidadãos desenvolverem um tipo de pensamento favorável à desconstrução do paradigma antropocêntrico que carateriza as sociedades ocidentais e as suas consequências mais diretas, nomeadamente a conceção do homem como legítimo explorador do meio natural em seu proveito e a da natureza como uma inesgotável fonte de bens ao dispor de todas as necessidades e desejos humanos” (Ramos e Ramos, 2013: 17). No caso, o protagonista é uma criança e o cenário da narrativa uma escola. A personagem principal repara numa pequena árvore que cresce no recreio. Tornar a árvore objeto de discurso individualiza-a e dá-lhe um estatuto especial, torna-a visível e atuante no mundo da criança-protagonista e das crianças-leitoras. Nesta narrativa, a fragilidade da árvore, decorrente do seu pequeno tamanho e da indiferença/invisibilidade de que é alvo, torna-a carente de cuidado e proteção. Protegendo a árvore, a criança-protagonista torna-se agente na edificação do meio e leva os seus colegas e a relutante professora a assumirem uma atitude semelhante. A obra reifica o passar do tempo, associado ao lento crescimento da árvore, e este transforma-se, tal como a relação afetiva estabelecida com a árvore, numa experiência significativa para as crianças. Assim, a obra oferece aos leitores uma experiência mediada, convidando-os a reposicionarem-se na sua relação com os elementos naturais do seu meio, promovendo a sua ecoliteracia.Fundos Nacionais através da FCT – Fundação para a Ciência e a Tecnologia no âmbito do projeto do CIEC (Centro de Investigação em Estudos da Criança da Universidade do Minho) com a referência UID/CED/00317/2019.info:eu-repo/semantics/draf

Probable Person-to-Person Transmission of Legionnaires’ Disease

Correspondence to the Editor.Legionnaires’ disease is an often severe form of pneumonia that is typically acquired by susceptible persons (e.g., elderly persons and smokers) through inhalation of aerosols that contain legionella species.1-4 A cluster of cases of this disease occurred in Vila Franca de Xira, Portugal, in 2014

A systematic analysis of printed circuit boards bending during in-circuit tests

When performing In-Circuit Tests (ICTs) of Printed Circuit Boards (PCBs), there are certain phenomena related with strain analysis that must be known in order to obtain stronger and more accurate testing results. During testing, PCBs are often subjected to mechanical bending efforts that induce excessive strain. This study focuses on the building of a Finite Elements Analysis (FEA) methodology that prevents excessive bending strain in critical points of a PCB during an ICT. To validate this methodology, a set of experimental tests, matched with a set of FEA, were carried out. Thus, companies, before the development of an ICT machine (fixture), will be able to use this FEA methodology to predict whether the maximum strain of a PCB under study, when subjected to its ICT, will damage it, thus reducing unnecessary production costs. A guideline was thus designed to enable the creation of the most representative Finite Elements Model (FEM) for any PCB, based on its amount and direction of copper traces.This work is co-funded by the European Regional Development Fund (ERDF) through the North Regional Operational Program (NORTE 2020) of the Portugal 2020 Program (Project No. 43922, with acronym “iFixturing”; Funding Reference NORTE-01-0247-FEDER-043922)

β-ketoenamine covalent organic frameworks—effects of functionalization on pollutant adsorption

Water pollution due to global economic activity is one of the greatest environmental concerns, and many efforts are currently being made toward developing materials capable of selectively and efficiently removing pollutants and contaminants. A series of β-ketoenamine covalent organic frameworks (COFs) have been synthesized, by reacting 1,3,5-triformylphloroglucinol (TFP) with different C2-functionalized and nonfunctionalized diamines, in order to evaluate the influence of wall functionalization and pore size on the adsorption capacity toward dye and heavy metal pollutants. The obtained COFs were characterized by different techniques. The adsorption of methylene blue (MB), which was used as a model for the adsorption of pharmaceuticals and dyes, was initially evaluated. Adsorption studies showed that –NO2 and –SO3H functional groups were favorable for MB adsorption, with TpBd(SO3H)2-COF [100%], prepared between TFP and 4,4′-diamine- [1,1′-biphenyl]-2,2′-disulfonic acid, achieving the highest adsorption capacity (166 ± 13 mg g−1). The adsorption of anionic pollutants was less effective and decreased, in general, with the increase in –SO3H and –NO2 group content. The effect of ionic interactions on the COF performance was further assessed by carrying out adsorption experiments involving metal ions. Isotherms showed that nonfunctionalized and functionalized COFs were better described by the Langmuir and Freundlich sorption models, respectively, confirming the influence of functionalization on surface heterogeneity. Sorption kinetics experiments were better adjusted according to a second-order rate equation, confirming the existence of surface chemical interactions in the adsorption process. These results confirm the influence of selective COF functionalization on adsorption processes and the role of functional groups on the adsorption selectivity, thus clearly demonstrating the potential of this new class of materials in the efficient and selective capture and removal of pollutants in aqueous solutions.This work was funded by the Coimbra Chemistry Centre (CQC), which is supported by the Fundação para a Ciência e a Tecnologia (FCT), Portugal, through the grants ref. UID/QUI/00313/2020 and ref. UI/BD/150809/2020, co-funded by COMPETE2020-UE