483 research outputs found
Cistus monspeliensis L. as a potential species for rehabilitation of soils with multielemental contamination under Mediterranean conditions
Conservation Biolog
Decomposition and nutrient release of leguminous plants in coffee agroforestry systems.
Leguminous plants used as green manure are an important nutrient source for coffee plantations, especially for soils with low nutrient levels. Field experiments were conducted in the Zona da Mata of Minas Gerais State, Brazil to evaluate the decomposition and nutrient release rates of four leguminous species used as green manures (Arachis pintoi, Calopogonium mucunoides, Stizolobium aterrimum and
Stylosanthes guianensis) in a coffee agroforestry system under two different climate conditions. The initial N contents in plant residues varied from 25.7 to 37.0 g kg-1 and P from 2.4 to 3.0 g kg-1. The lignin/N, lignin/polyphenol and(lignin+polyphenol)/N ratios were low in all residues studied. Mass loss rates were highest in the first 15 days, when 25 % of the residues were decomposed. From 15 to 30 days, the decomposition rate decreased on both farms. On the farm in Pedra Dourada (PD), the decomposition constant k increased in the order C. mucunoides < S. aterrimum < S. guianensis < A. pintoi. On the farm in Araponga (ARA), there was no difference in the decomposition rate among leguminous plants. The N release rates varied from 0.0036 to 0.0096 d-1. Around 32 % of the total N content in the plant material was released in the first 15 days. In ARA, the N concentration in the S. aterrimum residues was always significantly higher than in the other residues. At the end of 360 days, the N released was 78 % in ARA and 89 % in PD of the initial content. Phosphorus was the most rapidly released nutrient (k values from 0.0165 to 0.0394 d-1). Residue decomposition and nutrient release did not correlate with initial residue chemistry and biochemistry, but differences in climatic conditions between the two study sites modified the decomposition rate constants
Дискусійні питання історії ЗУНР
У статті аналізуються питання, які все ще залишаються в історіографії Західноукраїнської Народної Республіки. Автор звертає увагу на контроверсійні точки зору щодо революційних подій, які відбулися 1 листопада 1918 р. у Львові, стосовно часу існування ЗУНР, Акту злуки УНР та ЗУНР, причин поразки Української Галицької армії тощо.The author of the article analyses the questions that are still disputable in modern
Ukrainian historiography. The author attracts our attention to the controversial points
of view concerning the type of revolutionary events which took place on the 1 st of
November 1918 in Lviv, concerning the time of WUPR existence, concerning the Act of
Unification of Western Ukrainian People’s Republic end Ukrainian People’s Republic ,
concerning the reasons of the defeat of Ukrainian army, etc
Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.
The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground
biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main
factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by
the altitude and position of the area relative to the sun
UPLC-MS-ESI-QTOF analysis and antifungal activity of the spondias tuberosa arruda leaf and root hydroalcoholic extracts
The aim of this study was to identify and evaluate the chemical compositions and effects of the S. tuberosa leaf and root hydroalcoholic extracts (HELST and HERST) against different strains of Candida. Chemical analysis was performed by Ultra-Performance Liquid Chromatography Coupled to Quadrupole/Time of Flight System (UPLC-MS-ESI-QTOF). The Inhibitory Concentration of 50% of the growth (IC50) as well as the intrinsic and combined action of the extracts with the antifungal fluconazole (FCZ) were determined by the microdilution method while the minimum fungicidal concentrations (MFCs) and the effect on fungal morphological transitions were analyzed by subculture and in humid chambers, respectively. From the preliminary phytochemical analysis, the phenols and flavonoids were the most abundant. The intrinsic IC50 values for HELST ranged from 5716.3 to 7805.8 \ub5g/mL and from 6175.4 to 51070.9 \ub5g/mL for the HERST, whereas the combination of the extracts with fluconazole presented IC50 values from 2.65 to 278.41 \ub5g/mL. The MFC of the extracts, individually, for all the tested strains was 6516384 \ub5g/mL. When fluconazole was combined with each extract, the MFC against CA URM 5974 was reduced (HELST: 2048 and HERST: 4096 \ub5g/mL). Synergism was observed against standard C. albicans (CA) and C. tropicalis (CT) strains and with the root extract against the CT isolate. The leaf extract inhibited the morphological transition of all strains while the root extract inhibited only CT strains
Application Of The Hsu Model To Soybean Grain Hydration [aplicação Do Modelo De Hsu à Hidratação De Grãos De Soja]
A comparative analysis of the theoretical-experimental study, developed by Hsu on the hydration of Amsoy 71 soybean grain, was performed through several soaking experiments using CD 202 soybean at 10, 20, 30, 40, and 50 °C, measuring moisture content over time. The results showed that CD 202 soybean equilibrium moisture content, Xeq, does not depend on temperature and is 21% higher than that found by Hsu, suggesting that soybean cultivar exerts great influence on Xeq. The Hsu model was numerically solved and its parameters were adjusted by the least squares method, with maximum deviations of +/- 10% relative to the experimental values. The limiting step in the mass transfer process during hydration corresponds to water diffusion inside the grain, leading to radial moisture gradients that decrease over time and with an increase in temperature. Regardless of the soybean cultivar, diffusivity increases as temperature or moisture content increases. However, the values of this transport property for Amsoy 71 were superior to those of CD 202, very close at the beginning of hydration at 20 °C and almost three times higher at the end of hydration at 50 °C.301Adeyemi, I.A., Dry-milling of sorghum for ogi manufacture (1983) Journal of Cereal Science, 1 (3), pp. 221-227Ahromrit, A., Ledward, D.A., Niranjan, K., High pressure induced water uptake characteristics of Thai glutinous rice (2006) Journal of Food Engineering, 72 (3), pp. 225-233Barrozo, M.A.S., Calado, V.M.A., Calçada, L.A., Secagem de soja em leito deslizante e recirculação pneumática: Influência da umidificação artificial (1991) ENCONTRO SOBRE ESCOAMENTO EM MEIOS POROSOS, 1, pp. 327-337. , Campinas. Anais... São Paulo: UNICAMP, 1991Beckert, O.P., Miguel, M.H., Marcos Filho, J., Absorção de água e potencial fisiológico em sementes de soja de diferentes tamanhos (2000) Scientia Agrícola, 57 (4), pp. 671-675Calado, V.M.A., (1993) Modelagem E Simulação De Secadores Em Leitos Fixo E Deslizante, , Tese (Doutorado em Engenharia Química) - Universidade Federal doRio de Janeiro - UFRJ, Rio de JaneiroChopra, R., Prasad, D.N., Standardization of soaking conditions for soybean seeds/cotyledons for improved quality of soymilk (1994) Indian Journal of Animal Sciences, 64 (4), pp. 405-410Ciabotti, S., Características sensoriais e físicas de extratos e tofus de soja comum processada termicamente e livre de lipoxigenase (2007) Ciência E Tecnologia De Alimentos, 27 (3), pp. 643-648Coutinho, M.R., Modelagem e validação da hidratação de grãos de soja (2005) Ciência E Tecnologia De Alimentos, 25 (3), pp. 603-610Coutinho, M.R., Novo modelo de parâmetros concentrados aplicado à hidratação de grãos (2007) Ciência E Tecnologia De Alimentos, 27 (3), pp. 451-455Crank, J., (1975) The Mathematics of Diffusion, , 2 ed. London: Oxford University PressEngels, C., Modelling water diffusion during long-grain rice soaking (1986) Journal of Food Engineering, 5 (1), pp. 55-73Hsu, K.H., A diffusion model with a concentration-dependent diffusion coefficient for describing water movement in legumes during soaking (1983) Journal of Food Science, 48 (2), pp. 618-622+645Hsu, K.H., Effect of temperature on water diffusion in soybean (1983) Journal of Food Science, 48 (4), pp. 1364-1365INSTITUTO ADOLFO LUTZ - IAL. Normas analíticas do Instituto Adolfo Lutz. 3 ed. São Paulo, 1985. (v. 1)Klamczynska, B., Czuchajowska, Z., Baik, B., Composition, soaking, cooking properties and thermal characteristics of starch of chickpeas, wrinkled peas and smooth peas (2001) International Journal of Food Science and Technology, 36 (5), pp. 563-572Lo, W.Y.L., Soaking soybeans before extraction as it affects chemical composition and yield of soymilk (1968) Food Technology, 22 (9), pp. 1188-1190Long, F.A., Richman, D., Concentration gradients for diffusion of vapor in glassy polymers and their relation to time dependent diffusion phenomena (1960) Journal of The American Chemical Society, 82 (3), pp. 513-519Nelson, A.I., Steinberg, M.P., Wei, L.S., Illinois process for preparation of soymilk (1976) Journal of Food Science, 41 (1), pp. 57-61Pan, Z., Tangratanavalee, W., Characteristics of soybeans as affected by soaking conditions (2003) Lebensmittel-Wissenschaft Und-Technologie, 36 (1), pp. 143-151Peleg, M., An empirical model for the description of moisture sorption curves (1988) Journal of Food Science, 53 (4), pp. 1216-1219Singh, B.P.N., Kulshrestha, S.P., Kinetics of water sorption by soybean and pigeonpea grains (1987) Journal of Food Science, 52 (6), pp. 1538-1544Sopade, P.A., Obekpa, J.A., Modelling water absorption in soybean, cowpea and peanuts at three temperatures using Peleg's equation (1990) Journal of Food Science, 55 (4), pp. 1084-1087Wang, H.L., Hydration of whole soybeans affects solids losses and cooking quality (1979) Journal of Food Science, 44 (5), pp. 1510-151
The COVID-19 pandemic, emergency aid and social work in Brazil.
This essay reflects on the implementation of federal government emergency aid in Brazil in the context of the COVID-19 pandemic, highlighting elements from the work of Social Workers in the context of growing demand for the supply of material provisions. Economic and social conditions in Brazil have particularities that impact the operationalisation of this benefit, which is aimed at the poor, that add complexity and impose limits. When considering the structural limits set, this context imposes challenges on the work of Social Workers. The need to reconnect and enhance the struggle for social rights is emphasised through the different strategies of the working class
Reproductive dynamics of Leporinus obtusidens captured downstream from an important hydropower Station in Brazil
Produtividade de raízes de mandioca consorciada com milho e caupi em sistema orgânico.
Foram avaliados sistemas orgânicos de produção de mandioca “de mesa”, em Seropédica (RJ). O experimento constou dos seguintes tratamentos: monocultivo de mandioca (cv. IAC 576-70) e consórcios com milho experimental (cv. Eldorado), caupi (cv. Mauá) e milho+caupi. O manejo orgânico foi padronizado e toda a área experimental irrigada durante o período de permanência do milho no sistema. Do milho, foram colhidas espigas verdes (imaturas) e a parte aérea acamada na superfície do solo. O caupi foi incluído como adubo verde e cortado na floração, sendo mantidos os resíduos na superfície do solo. Ambos os consortes ocuparam as entrelinhas da mandioca, de modo alternado, semeados após a primeira capina da cultura principal. A cultivar IAC 576-70 mostrou-se adaptada ao manejo orgânico, com produtividade de raízes de padrão comercial próxima a 31 Mg ha-¹. Não houve diferenças significativas entre o monocultivo e os três tipos de consórcios testados. A inclusão do milho representou potencial de renda adicional ao produtor, colhendo-se,em média, 18.125 espigas ha-¹, o que correspondeu a 5,1 Mg ha-¹. Os resíduos provenientes da roçada do caupi proporcionaram um aporte de biomassa fresca de 12 Mg ha-¹, com uma expressiva contribuição em nitrogênio (cerca de 44 kg de N ha-1). A fabácea leguminosa cobriu por completo as entrelinhas da mandioca,demonstrando seu potencial de controle à erosão e a ervas espontâneas. O consórcio triplo mostrou-se vantajoso tendo em vista que a receita obtida com a venda do milho verde justificaria os custos da irrigação, além dos benefícios da inclusão do caupi e da não interferência dos consortes na produtividade da mandioca
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