991 resultados para Maize and U. ruziziensis intercropped
Resumo:
Esta investigación se centra en analizar la danza del vientre como una práctica sociocultural que transforma las subjetividades de sus practicantes, en el caso particular de las mujeres integrantes de la academia Anasi de Bogotá. Basada en la autoetnografía y a partir de experiencias individuales y colectivas de las mujeres integrantes del lugar, la danza es presentada como un proceso que conduce al empoderamiento femenino individual y colectivo. Esto sucede en el marco de una sociedad patriarcal, donde los cuerpos femeninos están cargados de connotaciones y limitaciones. Además de que el estilo dancístico ha sido dotado histórica y socialmente de prejuicios y nociones sexistas y machistas en torno a él y a sus bailarinas.
Resumo:
La monografía pretende explicar el rol desempeñado por Exxon Mobil y Chevron en la formulación de la Gran Estrategia del gobierno Bush hacia Irak. Especialmente, se sostiene que las dos compañías multinacionales mencionadas lograron que la intervención militar en Irak, fuera pensada como un objetivo fundamental de la política energética del gobierno Bush. Para lograr este objetivo, Chevron y Exxon aprovecharon principalmente su posición en la economía nacional estadounidense. De hecho, lograron celebrar contratos a largo plazo para la extracción del crudo y de gas en Irak. Fundamentándose en un análisis documental, estas compañías son analizadas como grupos de presión empresarial y grupos económicos, cuyos beneficios derivados de la invasión en Irak pueden encontrarse incluso durante el gobierno Obama.
Resumo:
La presente investigación parte del declive de la hegemonía de los Estados Unidos y el paralelo asenso económico de la República Popular China en las últimas décadas. De este modo, se plantea como objetivo principal analizar cómo China mediante su política económica desafía a la hegemonía monetaria de los Estado Unidos en el Sudeste Asiático, durante el periodo de 2003 a 2015. Con el fin de lograr este objetivo, se elabora un estudio de la hegemonía de los Estados Unidos y sus dinámicas en el Sudeste Asiático. Asimismo, se analiza la política económica de la República Popular China y su incidencia frente a la hegemonía estadounidense en el Sudeste Asiático.
Resumo:
The late Paleozoic collision between Gondwana and Laurussia resulted in the polyphase deformation and magmatism that characterizes the Iberian Massif of the Variscan orogen. In the Central Iberian Zone, initial con- tinental thickening (D1; folding and thrusting) was followed by extensional orogenic collapse (D2) responsible for the exhumation of high-grade rocks coeval to the emplacement of granitoids. This study presents a tectonometamorphic analysis of the Trancoso-Pinhel region (Central Iberian Zone) to ex- plain the processes in place during the transition froman extension-dominated state (D2) to a compression-dom- inated one (D3).Wereveal the existence of low-dipping D2 extensional structures later affected by several pulses of subhorizontal shortening, each of them typified by upright folds and strike-slip shearing (D3, D4 and D5, as identified by superimposition of structures). The D2 Pinhel extensional shear zone separates a low-grade domain from an underlying high-grade domain, and it contributed to the thermal reequilibration of the orogen by facil- itating heat advection from lower parts of the crust, crustal thinning, decompression melting, and magma intru- sion. Progressive lessening of the gravitational disequilibrium carried out by this D2 shear zone led to a switch from subhorizontal extension to compression and the eventual cessation and capture of the Pinhel shear zone by strike-slip tectonics during renewed crustal shortening. High-grade domains of the Pinhel shear zone were folded together with low-grade domains to define the current upright folded structure of the Trancoso-Pinhel re- gion, the D3 Tamames-Marofa-Sátão synform. Newdating of syn-orogenic granitoids (SHRIMP U\\Pb zircon dat- ing) intruding the Pinhel shear zone, together with the already published ages of early extensional fabrics constrain the functioning of this shear zone to ca. 331–311 Ma, with maximum tectonomagmatic activity at ca. 321–317 Ma. The capture and apparent cessation of movement of the Pinhel shear zone occurred at ca. 317– 311 Ma.
Resumo:
L’elaborato affronta il tema della massiccia diffusione di disinformazione tramite internet sotto il profilo del diritto costituzionale, nell’ottica di indagare se le dimensioni del fenomeno richiedano l’elaborazione di principi e soluzioni nuove ovvero se i paradigmi costituzionali enucleati dalla tradizione costituzionalistica con riferimento alla libertà d’espressione forniscano gli strumenti sufficienti per un intervento efficace. In tale ottica, il lavoro premette una ricostruzione del fenomeno della disinformazione nel tentativo di individuare il perimetro socio-cognitivo e tecnologico entro cui la medesima prolifera, descrivendo gli elementi che distinguono l’informazione diffusa dai nuovi media rispetto a quella veicolata dai media mainstream. Ciò premesso, lo studio passa a delineare lo “statuto costituzionale” del falso, indagando la rilevanza che la menzogna assume sotto il profilo costituzionale nel suo rapporto con la libertà di manifestazione del pensiero negli ordinamenti interno, europeo e statunitense. L’analisi prosegue poi con l’esame delle politiche di contrasto alla disinformazione introdotte da singoli Stati (prevalentemente Germania, Francia e Italia), Unione europea, e piattaforme, con l’obiettivo di mettere in luce vantaggi e limiti dei modelli di eteroregolamentazione, coregolamentazione e autoregolamentazione. Da ultimo, l’elaborato scompone alcune delle azioni e misure passate in rassegna e le analizza con la lente d’ingrandimento della libertà di manifestazione del pensiero, ordinandone i contenuti secondo la specifica propensione a comprimere la libertà d’espressione. L’indagine si conclude con alcuni brevi spunti conclusivi che evidenziano l’esigenza, in base ai principi costituzionali analizzati, che eventuali interventi normativi siano se del caso volti alla regolazione delle piattaforme, ovvero dei “contenitori”, lasciano i contenuti al libero scambio delle idee.
Resumo:
The 1d extended Hubbard model with soft-shoulder potential has proved itself
to be very difficult to study due its non solvability and to competition between terms of the Hamiltonian. Given this, we tried to investigate its phase diagram for filling n=2/5 and range of soft-shoulder potential r=2 by using Machine Learning techniques. That led to a rich phase diagram; calling U, V the parameters associated to the Hubbard potential and the soft-shoulder potential respectively, we found that for V<5 and U>3 the system is always in Tomonaga Luttinger Liquid phase, then becomes a Cluster Luttinger Liquid for 5
Resumo:
Maize demand for food, livestock feed, and biofuel is expected to increase substantially. The Western U.S. Corn Belt accounts for 23% of U.S. maize production, and irrigated maize accounts for 43 and 58% of maize land area and total production, respectively, in this region. The most sensitive parameters (yield potential [YP], water-limited yield potential [YP-W], yield gap between actual yield and YP, and resource-use efficiency) governing performance of maize systems in the region are lacking. A simulation model was used to quantify YP under irrigated and rainfed conditions based on weather data, soil properties, and crop management at 18 locations. In a separate study, 5-year soil water data measured in central Nebraska were used to analyze soil water recharge during the non-growing season because soil water content at sowing is a critical component of water supply available for summer crops. On-farm data, including yield, irrigation, and nitrogen (N) rate for 777 field-years, was used to quantify size of yield gaps and evaluate resource-use efficiency. Simulated average YP and YP-W were 14.4 and 8.3 Mg ha-1, respectively. Geospatial variation of YP was associated with solar radiation and temperature during post-anthesis phase while variation in water-limited yield was linked to the longitudinal variation in seasonal rainfall and evaporative demand. Analysis of soil water recharge indicates that 80% of variation in soil water content at sowing can be explained by precipitation during non-growing season and residual soil water at end of previous growing season. A linear relationship between YP-W and water supply (slope: 19.3 kg ha-1 mm-1; x-intercept: 100 mm) can be used as a benchmark to diagnose and improve farmer’s water productivity (WP; kg grain per unit of water supply). Evaluation of data from farmer’s fields provides proof-of-concept and helps identify management constraints to high levels of productivity and resource-use efficiency. On average, actual yields of irrigated maize systems were 11% below YP. WP and N-fertilizer use efficiency (NUE) were high despite application of large amounts of irrigation water and N fertilizer (14 kg grain mm-1 water supply and 71 kg grain kg-1 N fertilizer). While there is limited scope for substantial increases in actual average yields, WP and NUE can be further increased by: (1) switching surface to pivot systems, (2) using conservation instead of conventional tillage systems in soybean-maize rotations, (3) implementation of irrigation schedules based on crop water requirements, and (4) better N fertilizer management.
Resumo:
The feasibility of no-tillage in the Cerrado (Savanna-like vegetation of Brazil) depends on the production of sufficient above-ground crop residue, which can be increased by corn-forage intercropping. This study evaluated how above-ground crop residue production and yields of soybean and late-season corn in a soybean-corn rotation were influenced by the following crops in the year before soybean: corn (Zea mays L.) intercropped with Brachiaria (Urochloa) brizantha cv. Marandu, B. decumbens cv. Basilisk, B. ruziziensis, cv. comum., Panicummaximum cv. Tanzânia, sunn hemp (Crotalaria juncea L.), pigeon pea [Cajanus cajan (L.) Millsp]; sole corn, forage sorghum [Sorghum bicolor (L.) Moench (cv. Santa Elisa)], and ruzi grass. In March 2005, corn and forage species were planted in alternate rows spaced 0.90 m apart, and sole forage species were planted in rows spaced 0.45 m apart. In October 2005, the forages were killed with glyphosate and soybean was planted. After the soybean harvest in March 2006, sole late-season corn was planted in the entire experimental area. Corn grain and stover yields were unaffected by intercropping. Above-ground crop residue was greater when corn was intercropped with Tanzania grass (10.7 Mg ha-1), Marandu (10.1 Mg ha-1), and Ruzi Grass (9.8 Mg ha-1) than when corn was not intercropped (4.0 Mg ha-1). The intercropped treatments increased the percentage of soil surface covered with crop residue. Soybean and corn grain yields were higher after sole ruzi grass and intercropped ruzi grass than after other crops. The intercropping corn with Brachiaria spp. and corn with Panicum spp. increases above-ground crop residue production and maintains nutrients in the soil without reducing late-season corn yield and the viability of no-till in the midwestern region of Brazil.
Resumo:
Agricultural production systems that include the production of mulch for no-tillage farming and structural improvement of the soil can be considered key measures for agricultural activity in the Cerrado region without causing environmental degradation. In this respect, our work aimed to evaluate the chemical and physical-hydric properties of a dystrophic Red Latosol (Oxisol) in the municipality of Rio Verde, Goias, Brazil, under different soil management systems in the between-crop season of soybean cultivation five years after first planting. The following conditions were evaluated: Brachiaria brizantha cv. Marandu as a cover crop during the between-crop season; Second crop of maize intercropped with Brachiaria ruziziensis; Second crop of grain alone in a no-tillage system; Fallow soil after the soybean harvest; and Forest (natural vegetation) located in an adjacent area. Soil samples up to a depth of 40 cm were taken and used in the assessment of chemical properties and soil structure diagnostics. The results demonstrated that the conversion of native vegetation areas into agricultural fields altered the chemical and physical-hydric properties of the soil at all the depths evaluated, especially up to 10 cm, due to the activity of root systems in the soil structure. Cultivation of B. brizantha as a cover crop during the summer between-crop season increased soil water availability, which is important for agricultural activities in the region under study.
Resumo:
Light and water are among essential resources required for production of photosynthates in plants. A study on the effects of weeding regimes and maize planting density on light and water use was conducted during the 2001/2 short and 2002 long rain seasons at Muguga in - the central highlands of Kenya. Weeding regimes were: weed free (W1), weedy (W2), herbicide (W3) and hand weeding twice (W4). Maize planting densities were 9 (D1) and 18 plants m-2 (D2) intercropped with Phaseolus vulgaris (beans). The experiment was laid as randomized complete block design replicated four times and repeated twice. All plots were thinned to 4 plants m-2 at tasseling stage (96 DAE) and thinnings quantified as forage. Soil moisture content (SMC), photosynthetically active radiation (PAR) interception, evapo-transpiration (ET crop), water use efficiency (WUE), and harvest index (HI), were determined. Percent PAR was higher in D2 than in D1 before thinning but higher in D1 than in D2 after thinning in both seasons. PAR interception was highest in W2 but similar in W1, W3 and W4 in both seasons. SMC was significantly lower in W2 but similar in W1, W3 and W4. D2 had lower SMC than D1 in season two. Weeding regime significantly influenced ET crop, while planting density and weeding regime significantly influenced WUE and HI. D2 maximizes water and light use for forage production but results to increased intra-specific plant competition for water and light severely before thinning (96 DAE) that reduce grain yield in dual purpose maize, relative to D1.
Resumo:
Dietary management of the human gut microbiota towards a more beneficial composition is one approach that may improve host health. To date, a large number of human intervention studies have demonstrated that dietary consumption of certain food products can result in significant changes in the composition of the gut microbiota i.e. the prebiotic concept. Thus the prebiotic effect is now established as a dietary approach to increase beneficial gut bacteria and it has been associated with modulation of health biomarkers and modulation of the immune system. Promitor™ Soluble Corn Fibre (SCF) is a well-known maize-derived source of dietary fibre with potential selective fermentation properties. Our aim was to determine the optimum prebiotic dose of tolerance, desired changes to microbiota and fermentation of SCF in healthy adult subjects. A double-blind, randomised, parallel study was completed where volunteers (n = 8/treatment group) consumed 8, 14 or 21 g from SCF (6, 12 and 18 g/fibre delivered respectively) over 14-d. Over the range of doses studied, SCF was well tolerated Numbers of bifidobacteria were significantly higher for the 6 g/fibre/day compared to 12g and 18g/fibre delivered/day (mean 9.25 and 9.73 Log10 cells/g fresh faeces in the pre-treatment and treatment periods respectively). Such a numerical change of 0.5 Log10 bifidobacteria/g fresh faeces is consistent with those changes observed for inulin-type fructans, which are recognised prebiotics. A possible prebiotic effect of SCF was therefore demonstrated by its stimulation of bifidobacteria numbers in the overall gut microbiota during a short-term intervention.
Resumo:
One of the most fascinating aspects of plant morphology is the regular geometric arrangement of leaves and flowers, called phyllotaxy. The shoot apical meristem (SAM) determines these patterns, which vary depending on species and developmental stage. Auxin acts as an instructive signal in leaf initiation, and its transport has been implicated in phyllotaxy regulation in Arabidopsis (Arabidopsis thaliana). Altered phyllotactic patterns are observed in a maize (Zea mays) mutant, aberrant phyllotaxy1 (abph1, also known as abphyl1), and ABPH1 encodes a cytokinin-inducible type A response regulator, suggesting that cytokinin signals are also involved in the mechanism by which phyllotactic patterns are established. Therefore, we investigated the interaction between auxin and cytokinin signaling in phyllotaxy. Treatment of maize shoots with a polar auxin transport inhibitor, 1-naphthylphthalamic acid, strongly reduced ABPH1 expression, suggesting that auxin or its polar transport is required for ABPH1 expression. Immunolocalization of the PINFORMED1 (PIN1) polar auxin transporter revealed that PIN1 expression marks leaf primordia in maize, similarly to Arabidopsis. Interestingly, maize PIN1 expression at the incipient leaf primordium was greatly reduced in abph1 mutants. Consistently, auxin levels were reduced in abph1, and the maize PIN1 homolog was induced not only by auxin but also by cytokinin treatments. Our results indicate distinct roles for ABPH1 as a negative regulator of SAM size and a positive regulator of PIN1 expression. These studies highlight a complex interaction between auxin and cytokinin signaling in the specification of phyllotactic patterns and suggest an alternative model for the generation of altered phyllotactic patterns in abph1 mutants. We propose that reduced auxin levels and PIN1 expression in abph1 mutant SAMs delay leaf initiation, contributing to the enlarged SAM and altered phyllotaxy of these mutants.
Resumo:
The aim of this study was to evaluate the susceptibility of winter crops to Pratylenchus brachyurus and their effect on the population of phytonematodes in the maize. To study the effect of the plants on nematodes, an experiment was set up in sandy, naturally-infested soil. The area was divided into strips, consisting of six blocks of 16 treatments, with eight winter treatments, subdivided on the basis of the fertilizer used (organic: bird litter, and synthetic: NPK). The initial nematode population was determined by sampling the soil (100 cm(3)) and weeds (10 g of root). The winter treatments put in place (bristle oats, chickpea, vetch bean, common bean, oilseed radish, wheat, intercropped bristle oats + oilseed radish and fallow), and the nematode population determined 100 days after sowing. Subsequently, two maize crops (summer and short season) were planted, and the nematode population in the soil and roots determined during crop full bloom. To evaluate the susceptibility of winter crops to nematodes, an experiment was conducted under controlled conditions, determining the nematode reproduction factor (RF) in the treatments described above. Both in the field and under controlled conditions, it was observed that the bristle oats, oilseed radish and intercropped oats + oilseed radish exhibited lower reproduction rates for P. brachyurus. In the field, lower population of nematodes was observed with the application of bird litter. Under controlled conditions, the highest RF were observed in the fallow plot and under common bean and chickpea, in that order.
Resumo:
2016
Resumo:
Genetically modified foods are a major concern around the world due to the lack of information concerning their safety and health effects. This work evaluates differences, at the proteomic level, between two types of crop samples: transgenic (MON810 event with the Cry1Ab gene, which confers resistance to insects) and non-transgenic maize flour commercialized in Brazil. The 2-D DIGE technique revealed 99 differentially expressed spots, which were collected in 2-D PAGE gels and identified via mass spectrometry (nESI-QTOF MS/MS). The abundance of protein differences between the transgenic and non-transgenic samples could arise from genetic modification or as a result of an environmental influence pertaining to the commercial sample. The major functional category of proteins identified was related to disease/defense and, although differences were observed between samples, no toxins or allergenic proteins were found.