1,104 research outputs found

    A fileira da maça em Portugal - produção e mercados

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    A maçã é um dos principais frutos à escala mundial. Em Portugal a macieira está entre as principais espécies frutícolas ocupando cerca de 14 mil hectares, com produções próximas das 300 mil toneladas anuais. O mercado evoluiu para a diferenciação, apostando na certificação e qualificação, com nomes e modos de produção protegidos, bem como, produtos dirigidos a segmentos de mercado específicos, explorando a diversidade e possibilidade de escolha dos consumidores. Todavia, o sucesso do setor depende das ações coordenadas de toda a fileira, especialmente, no reforço da garantia da quantidade e qualidade do produto. Com o presente estudo pretende-se contribuir para o desenvolvimento e competividade da produção frutífera nacional, nomeadamente, de maça. Assim, analisa-se o setor da maça, retratando-o ao nível da produção, comercialização, consumo e comércio externo, incluindo, as estratégias de incremento do valor acrescentado adotadas. O estudo abarca o período 2005-2015 e tem por base múltipla informação estatística, complementada com outras fontes secundárias e informação primária, obtida junto de agentes integrantes na fileira.Este trabalho foi financiado por: Projeto PRODER, Medida 4.1. Introdução de telas anti granizo em macieira: avaliação de efeitos colaterais e impacte económico (PA 54823).info:eu-repo/semantics/publishedVersio

    Gestão de fertilizantes de libertação gradual de nutrientes em relvados municipais

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    Os fertilizantes de libertação lenta podem ajudar a reduzir as perdas de azoto (N) para o meio ambiente, disponibilizando os nutrientes à medida da necessidade das plantas. Neste trabalho apresentam-se resultados da utilização de fertilizantes de libertação gradual de nutrientes em relvados da Câmara Municipal de Valpaços. Foram implementados os tratamentos: Floranid permanent 16:7:15 (adubo de libertação lenta, IBDU/Isodur); Basacote plus 9M 16:8:12 (adubo de libertação controlada, copolímero etlileno acrílico); Nitroteck 20:8:10 (fertilizante estabilizado, DCD como inibidor da nitrificação + revestimento de politerpeno); Nitrolusal (20,5% N); e uma modalidade testemunha sem N. Os fertilizantes foram aplicados à razão de 120 kg N ha-1 em 11 de Março de 2007. O nitrolusal foi fracionado em duas aplicações. Determinou-se a produção de biomassa, em cortes sequênciais de março a setembro, a dinâmica do N, recorrendo a membranas de troca aniónica enterradas no solo, e a dinâmica da vegetação através de levantamentos florísticos. Foram calculados índices de eficiência económica do uso dos fertilizantes. A produção de matéria seca foi significativamente diferente entre tratamentos. Basacote produziu mais que testemunha e menos que Floranid, Nitroteck e Nitrolusal. Basacote retardou a libertação de N relativamente aos outros fertilizantes. Os índices de eficiência económica foram favoráveis a Nitroteck e desfavoráveis a Basacote, devido à grande diferença nos preços

    Nitrogen-use efficiency and economic efficiency of slow-release N fertilisers applied to irrigated turfs in a Mediterranean environment

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    The effect of three fertilisers that delay the bioavailability of nitrogen (N) in the soil was compared with ammonium nitrate and a zero N control in two irrigated turfs in NE Portugal. The fertilisers used were: Floranid permanent 16-7-15 (slow-release, IBDU/Isodur fertiliser); Basacote plus 9M 16-8-12 (controlled-release fertiliser, copolymer ethylene acrylic); Nitroteck 20-8-10 (stabilized fertiliser, dicyandiamide as nitrification inhibitor + coating with polyterpene) and Nitrolusal (ammonium nitrate, 20.5% N), applied all at a rate of 120 kg N ha-1. Nitrolusal was split into two fractions of 60 kg N ha-1. Phosphorus (P) and potassium (K) rates were balanced among treatments by using superphosphate (18% P2O5) and potassium chloride (60% K2O). The turf dry matter (DM) yield and N concentration in dry material were determined from several cuts of biomass throughout the growing season. Based on DM yield, N concentration in dry material and fertilisation costs, indices of N use efficiency and economic efficiency were estimated. Soil nitrate levels were monitored by using anion exchange membranes inserted directly into the soil. Basacote gave significantly lower DM yields than the other fertilised treatments. The apparent N recovery of Basacote was also the lowest. The results showed that Basacote released less N than that required for an adequate plant growth in the beginning of the growing season, hampered the flush of spring growth. Furthermore, the release period of this Basacote formulation, in the environmental conditions of these experiments, seemed to be longer than the length of the growing season. Nitroteck and Floranid yielded similar or even higher DM and apparent N recovery values than did Nitrolusal. The indices of economic efficiency ordered the fertilisers as Nitroteck > Nitrolusal > Floranid > Basacote or Nitrolusal > Nitroteck > Floranid > Basacote, if the costs of P and K fertilisers used to balance the P and K rates in the experimental design were, respectively, taken or not taken into account

    Effects of foliar and soil boron fertilization on yield, leaf physiological traits and fruit attributes in rainfed almond orchards

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    Boron (B) fertilizers are recognized as essential for ensuring yield and fruit quality. However, the importance of soil and foliar B fertilization in almond orchards under rainfed conditions is presently unclear. To address this literature gap, in the present study, the impact of soil and foliar application of B on leaf gas exchange, leaf photosynthetic pigments, yield, and fruit quality in almonds was investigated across three consecutive growing seasons. Boron fertilizer was applied to the soil at four rates (0, 1, 2, and 3 kg ha−1) in the presence or absence of foliar application (0.36 g L−1) of the same micronutrient. Borax pentahydrate was used as the B source. When compared to foliar B fertilization, the soil application of B positively affected the gas exchange parameters, mainly the net CO2 assimilation rate, stomatal conductance, and transpiration rate (percentage of gain between 15% and 80%), but did not influence the chlorophyll content. The almond yield and fruit characteristics were also enhanced (about 25–72%) in response to lower soil B fertilization rates. In the 3 kg ha−1 dose, B had an adverse effect on the yield and resulted in lighter fruits. On the other hand, foliar B fertilization did not benefit any of the evaluated parameters. Overall, these results suggest that, under the studied conditions, almond orchards do not respond to higher B rates in soil or foliar B fertilization.This research work was funded by the project “Estratégias integradas para o aumento da produtividade da amendoeira em Trás-os-Montes”, no. 54611, funded by the EAFRD (European Agricultural Fund for Rural Development), and by the Portuguese State through the “Medida 4.1. Cooperação para a Inovação do programa PRODER-Programa de Desenvolvimento Rural”. The authors also acknowledge to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020) and CITAB (UIDB/04033/2020).info:eu-repo/semantics/publishedVersio

    Periodontal disease and diabetes : review of the literature

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    Aims: To provide updated knowledge on the relationship between periodontal disease and diabetes from an oral health perspective. Methods: A review of the English-language literature was performed, gathering articles on the two diseases published over the past 10 years. Results: Both diseases result from the confluence of various triggering and modifying factors, and there are inter-individual differences in the risk of their development. Recent research has shown that diabetes may increase the risk of periodontitis, and it has been proposed that chronic periodontal disease may influence the natural course of diabetes. There appears to be an association among oral infections, impaired sugar metabolism, and atherosclerosis, indicating a theoretical link between metabolic syndrome and periodontal disease. Clinical implications: Control of periodontal disease may enhance glycemic control in patients with type 2 diabetes. In turn, improved glycemic control may contribute to a better control of periodontal disease. © Medicina Oral S. L

    Ovulatory and metabolic effects of D-chiro-inositol in the polycystic ovary syndrome

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    BACKGROUND Women with the polycystic ovary syndrome have insulin resistance and hyperinsulinemia, possibly because of a deficiency of a d-chiro-inositol–containing phosphoglycan that mediates the action of insulin. We hypothesized that the administration of d-chiro-inositol would replenish stores of the mediator and improve insulin sensitivity. METHODS We measured steroids in serum and performed oral glucose-tolerance tests before and after the oral administration of 1200 mg of d-chiro-inositol or placebo once daily for six to eight weeks in 44 obese women with the polycystic ovary syndrome. The serum progesterone concentration was measured weekly to monitor for ovulation. RESULTS In the 22 women given d-chiro-inositol, the mean (±SD) area under the plasma insulin curve after the oral administration of glucose decreased from 13,417±11,572 to 5158±6714 μU per milliliter per minute (81±69 to 31±40 nmol per liter per minute) (P=0.007; P=0.07 for the comparison of this change with the change in the placebo group); glucose tolerance did not change significantly. The serum free testosterone concentration in these 22 women decreased from 1.1±0.8 to 0.5±0.5 ng per deciliter (38±28 to 17±17 pmol per liter) (P=0.006 for the comparison with the change in the placebo group). The women\u27s diastolic and systolic blood pressure decreased by 4 mm Hg (Pchiro-inositol ovulated, as compared with 6 of the 22 women in the placebo group (P\u3c0.001). CONCLUSIONS d-Chiro-inositol increases the action of insulin in patients with the polycystic ovary syndrome, thereby improving ovulatory function and decreasing serum androgen concentrations, blood pressure, and plasma triglyceride concentrations

    Parallel Cellular Automata-based Simulation of Laser Dynamics using Dynamic Load Balancing

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    We present an analysis of the feasibility of executing a parallel bioinspired model of laser dynamics, based on cellular automata (CA), on the usual target platform of this kind of applications: a heterogeneous non-dedicated cluster. As this model employs a synchronous CA, using the single program, multiple data (SPMD) paradigm, it is not clear in advance if an appropriate efficiency can be obtained on this kind of platform. We have evaluated its performance including artificial load to simulate other tasks or jobs submitted by other users. A dynamic load balancing strategy with two main differences from most previous implementations of CA based models has been used. First, it is possible to migrate load to cluster nodes initially not belonging to the pool. Second, a modular approach is taken in which the model is executed on top of a dynamic load balancing tool – the Dynamite system – gaining flexibility. Very satisfactory results have been obtained, with performance increases from 60% to 80%.Ministerio de Ciencia e Innovación TIN2007-68083-C02Junta de Extremadura PRI06A22

    Solid-liquid phase equilibrium of trans-cinnamic acid, p-coumaric acid and ferulic acid in water and organic solvents: Experimental and modelling studies

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    The solubility of the trans isomers of cinnamic acid, p-coumaric acid and ferulic acid was measured in water and seven organic solvents (methanol, ethanol, 1-propanol, 2-propanol, 2-butanone, ethyl acetate and acetonitrile), at 298.2 K and 313.2 K, using the analytical shake-flask technique. The melting temperatures and enthalpies of the solutes were studied by differential scanning calorimetry, while solute solid structures were identified by powder and single X-ray diffraction. The NRTL-SAC model was applied to calculate the solubility of trans-cinnamic acid and trans-ferulic acid in pure solvents. For trans-p-coumaric acid, the NRTL-SAC was combined with the Reference Solvent Approach, as the solute melting properties could not be determined. The global average relative deviations (ARD) were 32% and 41%, in the correlation and prediction stages, respectively. The Abraham solvation model was also applied. The global ARD were 20% for correlation and 29% for predictions, which can be considered very satisfactory results for these semi-predictive models.This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/ 50011/2020, and CIMO-Mountain Research Center, UIDB/00690/ 2020, both financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. We also acknowledge the support of the projects “AIProcMat@N2020 - Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE-01-0145-FEDER- 000006, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); and project AllNat - POCI-01-0145-FEDER-030463, funded by the European Regional Development Fund (ERDF) through the Competitiveness and Internationalization Operational Program (COMPETE2020-POCI) and national funding from the Foundation for Science and Technology (FCT, Portugal). S. M. Vilas-Boas thanks the financial support provided by FCT PhD grant (SFRH/BD/138149/ 2018).info:eu-repo/semantics/publishedVersio

    Surface characterization of human serum albumin and sodium perfluorooctanoate mixed solutions by pendant drop tensiometry and circular dichroism

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    The interfacial behavior of mixed human serum albumin (HSA)/sodium perfluorooctanoate (C8FONa) solutions is examined by using two experimental techniques, pendant drop tensiometry and circular dichroism spectroscopy. Through the analysis of the surface tension of the mixed solutions, surface competitive adsorption at the air-water interface between C8FONa and HSA is detected. The dynamic adsorption curves exhibit the distinct regimes in their time-dependent surface tension. The nature of these regimes is further analyzed in terms of the variation of the molecules surface areas. As a consequence, a compact and dense structure was formed where protein molecules were interconnected and overlapped. Thus, a reduction of the area occupied per molecule from 100 to 0.2 nm2 is interpreted as a gel-like structure at the surface. The presence of the surfactant seems to favor the formation of this interfacial structure. Finally, measurements of circular dichroism suggests a compaction of the protein due to the association with the surfactant given by an increase of α-helix structure in the complexes as compared to that of pure protein.Fil: Messina, Paula Verónica. Universidad de Santiago de Compostela; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Prieto, Gerardo. Universidad de Santiago de Compostela; EspañaFil: Dodero, Veronica Isabel. Universidad de Santiago de Compostela; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Cabrerizo-Vilchez, M.A.. Universidad de Granada. Facultad de Ciencias; EspañaFil: Maldonado Valderrama, J.. Universidad de Granada. Facultad de Ciencias; EspañaFil: Ruso, Juan M.. Universidad de Santiago de Compostela; EspañaFil: Sarmiento, Félix. Universidad de Santiago de Compostela; Españ
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