646 research outputs found
Melhoramento do Panicum maximum apresentacao do projeto e do material.
bitstream/item/137547/1/PESQ-EM-ANDAMENTO-24.pdfCNPGC
Effects of Selection on Morphological Characteristics in \u3ci\u3eSetaria sphacelata\u3c/i\u3e (Schumach.) Moss
Cattle production in Florida is limited by the lack of available warm-season forages adapted to the cool winters of the region. Setaria (S. sphacelata) has demonstrated green growth during cool conditions in subtropical climates around the world, and has the potential to fill this niche in cattle production in Florida. Four populations were selected in Gainesville and Ona, Florida: two cycles of selection for increased head number, one cycle for increased leaf width and one cycle for grazing tolerance. The objectives of this research were to compare these populations morphologically to determine changes due to selection. Selection for leaf width increased this trait while maintaining other morphological characteristics constant. Selection for head number decreased plant height and increased head number in each cycle, and decreased leaf width and inflorescence length in the second cycle. Selection for grazing regrowth resulted in reduced plant height and inflorescence length. Concern regarding susceptibility of Setaria to chinch bug and possible winter killing in Florida remain to be resolved before this species may be commercialized in Florida
Registro de 25 acessos selecionados de Panicum maximum.
bitstream/item/104715/1/Registro-de-25-acesso.pd
Utilization of an Electron-Beam Tester for Determining Internal Electric Field Profiles in Micro-Structured Thin-Film Semiconductor Devices
An electron-beam tester was used to determine the depth profile of the internal potential distribution in an a-Si:H solar cell and hence the internal electric field profile. The a-Si:H solar cells were prepared for the measurements with the electron-beam tester by low-energy chemical plasma beam etching through a plasma-resistant mask structured by electron-beam lithography. In contrast to an earlier work, the solar cells were in situ illuminated and the electric field profiles were determined for new, degraded and in situ annealed solar cells at various cell temperatures. The measuring results demonstrate that the electron-beam testing technique in combination with a suitable micro-structure preparation method is appropriate to measure internal electric field profiles in semiconductor devices as, e.g., solar cells for arbitrarily chosen bias and illumination states
Pasture diversification through selection of new Panicum maximum cultivars in Brazil.
Cattle rearing in Brazil depends almost exclusively on pastures, of which, 35 °/o consist of cultivated introduced species. Guineagrass, Panicun maximum Jacq. is the main introduced forage grass species in cattle finishing, because of its ease of propagation, fast establishment after sowing and rapid and abundant growth of high quality forage during the rainy season. About 10 cultivars are commercialized in the country, the most important being « Colonião » : a tall. tufted perennial plant (up to 3.5 m) with erect stems and long leaves (up to l.0 m). It presents management problems however; when allowed to grow excessively, leaf/stem ratio decreases reducing quality, and stems are rejected by cattle. Excessive extraction of nutrients from the soil to permit this growth, and little or no regrowth in the dry season result in pasture degradation after a few years
Selection of morphological traits to improve forage characteristics of Setaria sphacelata grown in Florida.
A genetically diverse population of Setaria sphacelata was developed at Gainesville, Florida by intercrossing the cultivars ?Narok?, ?Kazungula? and ?Solander? and a local persistent population. To determine heritability of traits that may improve setaria as a forage plant in Florida, progeny of the intercrossed population underwent two cycles of selection for inflorescence number and one cycle for leaf width. The selected populations, together with cultivars and introductions, were evaluated for morphological characters, yield and forage quality in field experiments with close- and wide-spaced plants. Increase of inflorescence number was not obtained by selection but resulted in decreased plant height, inflorescence length, yield, leaf width, and leafiness. Leaf width was increased by selection and was associated with increased leafiness and whole-plant crude protein content. The results suggest good prospects for selection of setaria cultivars suited to Florida with improved yield and quality providing they tolerate winter cold and reliably produce seed
Competition Between Auctions
Even though auctions are capturing an increasing share of commerce, they are typically treated in the theoretical economics literature as isolated. That is, an auction is typically treated as a single seller facing multiple buyers or as a single buyer facing multiple sellers. In this paper, we review the state of the art of competition between auctions. We consider three different types of competition: competition between auctions, competition between formats, and competition between auctioneers vying for auction traffic. We highlight the newest experimental, statistical and analytical methods in the analysis of competition between auctions.auctions, bidding, competition, auction formats, auction houses
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