997 resultados para Grafting influence


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The effect of organic and conventional agricultural systems on the physicochemical parameters, bioactive compounds content, and sensorial attributes of tomatoes (‘‘Redondo’’ cultivar) was studied. The influence on phytochemicals distribution among peel, pulp and seeds was also accessed. Organic tomatoes were richer in lycopene (+20%), vitamin C (+30%), total phenolics (+24%) and flavonoids (+21%) and had higher (+6%) in vitro antioxidant activity. In the conventional fruits, lycopene was mainly concentrated in the pulp, whereas in the organic ones, the peel and seeds contained high levels of bioactive compounds. Only the phenolic compounds had a similar distribution among the different fractions of both types of tomatoes. Furthermore, a sensorial analysis indicated that organic farming improved the gustative properties of this tomato cultivar.

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Cubic cobalt nitride films were grown onto different single crystalline substrates Al2O3 (0 0 0 1) and (1 1 View the MathML source 0), MgO (1 0 0) and (1 1 0) and TiO2 (1 0 0) and (1 1 0). The films display low atomic densities compared with the bulk material, are ferromagnetic and have metallic electrical conductivity. X-ray diffraction and X-ray absorption fine structure confirm the cubic structure of the films and with RBS results indicate that samples are not homogeneous at the microscopic scale, coexisting Co4+xN nitride with nitrogen rich regions. The magnetization of the films decreases with increase of the nitrogen content, variation that is shown to be due to the decrease of the cobalt density, and not to a decrease of the magnetic moment per cobalt ion. The films are crystalline with a nitrogen deficient stoichiometry and epitaxial with orientation determined by the substrate.

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We investigate the structural chain-to-ring transition at low temperature in a gas of dipolar hard spheres (DRS). Due to the weakening of entropic contribution, ring formation becomes noticeable when the effective dipole-dipole magnetic interaction increases, It results in the redistribution of particles from usually observed flexible chains into flexible rings. The concentration (rho) of DI-IS plays a crucial part in this transition: at a very low rho only chains and rings are observed, whereas even a slight increase of the volume fraction leads to the formation of branched or defect structures. As a result, the fraction of DHS aggregated in defect-free rings turns out to be a non-monotonic function of rho. The average ring size is found to be a slower increasing function of rho when compared Lo that of chains. Both theory and computer simulations confirm the dramatic influence of the ring formation on the rho-dependence of the initial magnetic susceptibility (chi) when the temperature decreases. The rings clue to their zero total dipole moment are irresponsive to a weak magnetic field and drive to the strong decrease of the initial magnetic susceptibility. (C) 2014 Elsevier B.V. All rights reserved.

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Different anthropogenic sources of metals can result from agricultural, industrial, military, mining and urban activities that contribute to environmental pollution. Plants can be grown for phytoremediation to remove or stabilize contaminants in water and soil. Copper (Cu), manganese (Mn) and zinc (Zn) are trace essential metals for plants, although their role in homeostasis in plants must be strictly regulated to avoid toxicity. In this review, we summarize the processes involved in the bioavailability, uptake, transport and storage of Cu, Mn and Zn in plants. The efficiency of phytoremediation depends on several factors including metal bioavailability and plant uptake, translocation and tolerance mechanisms. Soil parameters, such as clay fraction, organic matter content, oxidation state, pH, redox potential, aeration, and the presence of specific organisms, play fundamental roles in the uptake of trace essential metals. Key processes in the metal homeostasis network in plants have been identified. Membrane transporters involved in the acquisition, transport and storage of trace essential metals are reviewed. Recent advances in understanding the biochemical and molecular mechanisms of Cu, Mn and Zn hyperaccumulation are described. The use of plant-bacteria associations, plant-fungi associations and genetic engineering has opened a new range of opportunities to improve the efficiency of phytoremediation. The main directions for future research are proposed from the investigation of published results.

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This work intends to evaluate the (mechanical and durability) performance of concrete made with coarse recycled concrete aggregates (CRCA) obtained using two crushing processes: primary crushing (PC) and primary plus secondary crushing (PSC). This analysis intends to select the most efficient production process of recycled aggregates (RA). The RA used here resulted from precast products (P), with strength classes of 20 MPa, 45 MPa and 65 MPa, and from laboratory-made concrete (L) with the same compressive strengths. The evaluation of concrete was made with the following tests: compressive strength; splitting tensile strength; modulus of elasticity; carbona-tion resistance; chloride penetration resistance; capillary water absorption; and water absorption by immersion. These findings contribute to a solid and innovative basis that allows the precasting industry to use without restrictions the waste it generates. © (2015) Trans Tech Publications, Switzerland.

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At this moment, the duality of species suggested for E. histolytica is being considered for discussion. In order to contribute to settling this question, we investigated the possibility of conversion of avirulent ameba to virulent ones, as well as, the possibility of increasing virulence of virulent strains, by means of association with bacteria. Five strains of E. histolytica were employed, two of them regarded as avirulent and three virulent ones. Amebas were associated with the bacteria Escherichia coli 055 and 0115, previously demonstrated as capable to modify the pathogenic behavior of E. histolytica. Changes in virulence of amebas were assessed by cytopathic effect upon cultured mammal cells and erythrophagocytosis. The virulence of pathogenic strains was significantly increased after bacteria association in opposition to what was observed for nonpathogenic ones, which were not influenced by bacteria association.

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In these experiments the ratio of male to female S. mansoni larvae in D. glabrata from Belo Horizonte and Ribeirão das Neves Minas Gerais, Brazil, either reared in laboratoty or collected in the field, varied from 1:1 to 1:1.3 or 1.4:1. Cercariae of LE strain of Schistosoma mansoni, shed by 39 snails maintained at 25±0.5ºC were used to infect mice on a weekly basis. Subsequent perfusion resulted in 76.6% male and 23.4% female worms. The cercariac produced by 32 infected snails maintained at 27+0.5°C were inoculated into mice and produced 43.4% male and 56.6% female worms (p<0.05). Cercariae eliminated by snails collected in Barreiro and Ressaca, Belo Horizonte, during hot months, produced 45.7 to 47.7% male and 52.3 to 54.3% female worms. A lower number of cercariae shed by snails collected in Gorduras, Belo Horizonte, at 20+3.0°C, produced 51.6% male and 48.4% female worms. Thus, in this region the infection of vertebrate hosts with S. mansoni cercariae would be more severe in the summer due to the higher level of parasites and the number of eggs.

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This chapter examines the cross-cultural influence of training on the adjustment of international assignees. We focus on the pre-departure training (PDT) before an international assignment. It is an important topic because in the globalized world of today more and more expatriations are needed. The absence of PDT may generate the failure of the expatriation experience. Companies may neglect PDT due to cost reduction practices and ignorance of the need for it. Data were collected through semi-structured interviews to 42 Portuguese international assignees and 18 organizational representatives from nine Portuguese companies. The results suggest that companies should develop PDT programs, particularly when the cultural distance to the host country is bigger and when there is no previous experience of expatriation to that country in the company. The study is original because it details in depth the methods of PDT, its problems, and consequences. Some limitations linked to the research design and detailed in the conclusion should be overcome in future studies.

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The increase of electricity demand in Brazil, the lack of the next major hydroelectric reservoirs implementation, and the growth of environmental concerns lead utilities to seek an improved system planning to meet these energy needs. The great diversity of economic, social, climatic, and cultural conditions in the country have been causing a more difficult planning of the power system. The work presented in this paper concerns the development of an algorithm that aims studying the influence of the issues mentioned in load curves. Focus is given to residential consumers. The consumption device with highest influence in the load curve is also identified. The methodology developed gains increasing importance in the system planning and operation, namely in the smart grids context.

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Energy resource scheduling is becoming increasingly important, as the use of distributed resources is intensified and of massive electric vehicle is envisaged. The present paper proposes a methodology for day-ahead energy resource scheduling for smart grids considering the intensive use of distributed generation and Vehicle-to-Grid (V2G). This method considers that the energy resources are managed by a Virtual Power Player (VPP) which established contracts with their owners. It takes into account these contracts, the users' requirements subjected to the VPP, and several discharge price steps. The full AC power flow calculation included in the model takes into account network constraints. The influence of the successive day requirements on the day-ahead optimal solution is discussed and considered in the proposed model. A case study with a 33-bus distribution network and V2G is used to illustrate the good performance of the proposed method.

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Brazil's nosologic profile has been sustaining profound modifications. Some occurred because of massive immunization campaigns and socioeconomic and demographic trends. Some yet were pure nosologic transitions, such as the emergence of AIDS. In this demand study it is described how these changes reflected on the 8,630 admissions of an Infectious Diseases Department in Niterói, along a thirty year period. Brazilian rural endemic diseases were infrequent (3.45%). Men predominated (62%) all the time, in all age strata and in nearly all diseases. Children under fifteen predominated until 1983. There was, in the case of tetanus, a striking rise in age strata. Institutional mortality dropped from 31% in 1965 to 10% in 1984, but rose since then to 15% in 1994. However, if AIDS patients had not been computed, mortality would have kept descending till 8% at the end of the study period. The crescent unimportance of immunopreventable diseases paralleled with the growing prominence of AIDS. In less than a decade, AIDS ranked fifth among the most frequent diseases in the whole period of thirty years. As opposed to the immunopreventable diseases, neither meningitides nor pneumonia appear to be in decline. AIDS, by its exponential incidence, by its chronic character, and by the uncountable opportunistic infections it determines, imposes itself as a challenge for the coming years.

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Risk acceptance has been broadly discussed in relation to hazardous risk activities and/or technologies. A better understanding of risk acceptance in occupational settings is also important; however, studies on this topic are scarce. It seems important to understand the level of risk that stakeholders consider sufficiently low, how stakeholders form their opinion about risk, and why they adopt a certain attitude toward risk. Accordingly, the aim of this study is to examine risk acceptance in regard to occupational accidents in furniture industries. The safety climate analysis was conducted through the application of the Safety Climate in Wood Industries questionnaire. Judgments about risk acceptance, trust, risk perception, benefit perception, emotions, and moral values were measured. Several models were tested to explain occupational risk acceptance. The results showed that the level of risk acceptance decreased as the risk level increased. High-risk and death scenarios were assessed as unacceptable. Risk perception, emotions, and trust had an important influence on risk acceptance. Safety climate was correlated with risk acceptance and other variables that influence risk acceptance. These results are important for the risk assessment process in terms of defining risk acceptance criteria and strategies to reduce risks.

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Germfree (GF) and conventional (CV) mice were fed on diets containing 4.4, 13.2 or 26.4% of protein (weight/weight). CV mice fed on low protein diet did not gain weight during four weeks, whereas the protein deficient diet did not affect the growth of GF mice. After four weeks on these diets, the mice were inoculated with 5x103 trypomastigotes of Trypanosoma cruzi. The protein deficiency affected less the GF than the CV mice, according to the following parameters: weight gain, hemoglobin, plasma protein and albumin levels and water and protein contents of the carcass. Infection with T. cruzi produced a significant decrease in hemoglobin levels, red blood cell count, and water and protein contents in the carcass. This decrease was more pronounced in the GF mice. Histopathologically, there was no difference between the treatments in animals with the same microbiological status (GF or CV). However, the disease was more severe in the GF than in the CV mice.

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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Química e Bioquímica

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Infection of Swiss/NIH mice with Leishmania major was compared with infection in isogenic resistant C57BL/6 and susceptible BALB/c mice. Swiss/NIH mice showed self-controlled lesions in the injected foot pad. The production of high levels of interferon-g (IFN-g) and low levels of interleukin-4 (IL-4) by cells from these animals suggests that they mount a Th1-type immune response. The importance of the indigenous microbiota on the development of murine leishmaniasis was investigated by infecting germfree Swiss/NIH in the hind footpad with L. major and conventionalizing after 3 weeks of infection. Lesions from conventionalized Swiss/NIH mice were significantly larger than conventional mice. Histopathological analysis of lesions from conventionalized animals showed abscesses of variable shapes and sizes and high numbers of parasitized macrophages. In the lesions from conventional mice, besides the absence of abscess formation, parasites were rarely observed. On the other hand, cells from conventional and conventionalized mice produced similar Th1-type response characterized by high levels of IFN-g and low levels of IL-4. In this study, we demonstrated that Swiss/NIH mice are resistant to L. major infection and that the absence of the normal microbiota at the beginning of infection significantly influenced the lesion size and the inflammatory response at the site of infection.