983 resultados para Sercial variety
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Sequence-Characterized Amplified Region (SCAR) appears as a useful technique for genetic purity testing and variety discrimination, applicable to species in which some other techniques have failed. In particular, this technique is very attractive with species in which RAPD results were not consistent. The RAPD polymorphic bands were cloned, sequenced and from the sequence information, primers pairs for normal PCR were developed. Since the probability of obtaining successful SCAR primers from RAPD polymorphic bands was about 50%, a larger number of RAPD polymorphic bands are needed to develop sufficient SCAR primers for varietal discrimination in vinca. In addition, the efficiency of the SCAR technique is strongly affected by the quality of DNA extracted from seeds. The SCAR banding patterns obtained from vinca seed were consistent and repeatable making the results reliable for genetic purity testing and variety discrimination. The SCAR technique is simple, fast, relatively inexpensive and allows the use of DNA extracted from dry seeds, which is very important in a seed-quality evaluating program
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Among the environmental factors that can affect food intake is the extent of dietary variety available in the environment. Numerous studies have demonstrated that variety in a meal can increase the amount of food consumed in humans, rats, and other species. A physiological mechanism that has been demonstrated to affect food intake is the gut peptide cholecystokinin (CCK) which is released from the upper small intestine during the ingestion of food. Peripherally administered CCK has a robust inhibitory effect on the intake of a single-food meal. Thus, dietary variety and CCK both affect meal size, with dietary variety increasing intake and CCK decreasing intake. This raises the question ofhow dietary variety and CCK might interact to affect meal size. Previous studies of CCK's effects have focused on situations in which only one food was available for consumption. However, in an animal's natural environment it would frequently occur that the animal would come across a number of foods either simultaneously or in quick succession, thus providing the animal access to a variety of foods during a meal. Accordingly, the effect ofCCK on food intake in single-food and multiple-food meals was examined. It was found that food intake was greater in multiple-food than in single-food meals provided that foods in the multiplefood meal were presented either simultaneously or in increasing order of preference. When foods in the multiple-food meal were presented in decreasing order of preference, intake was similar to that observed in single-food meals. In addition, it was found that CCK inhibited food intake in a dose-dependent manner, and that its effects on food intake were similar regardless of meal type. Therefore, the inhibitory effects ofCCK were not diminished when a variety of foods were available for consumption. Furthermore, the finding that CCK did not differentially affect the intake of the two types of meals does not provide support for the recent-foods hypothesis which postulates that CCK decreases food intake by reducing the palatability of only recently consumed foods. However, it is consistent with the all-foods hypothesis, which predicts that CCK reduces food intake by decreasing the palatability of all foods. The 600 ng/kg dose of the CCK^-antagonist lorglumide significantly antagonized the inhibitory effect of exogenous CCK on food intake, and the magnitude of this effect was similar for both types of meal. These results suggest that exogenous CCK inhibits food intake through the activation ofCCK^ receptors. However, when administered by itself, the 600^ig/kg dose of lorglumide did not increase food intake in either single-food or multiple-food meals, suggesting that peripheral endogenous CCK may not play a major role in the control of food intake.
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Ordered gene problems are a very common classification of optimization problems. Because of their popularity countless algorithms have been developed in an attempt to find high quality solutions to the problems. It is also common to see many different types of problems reduced to ordered gene style problems as there are many popular heuristics and metaheuristics for them due to their popularity. Multiple ordered gene problems are studied, namely, the travelling salesman problem, bin packing problem, and graph colouring problem. In addition, two bioinformatics problems not traditionally seen as ordered gene problems are studied: DNA error correction and DNA fragment assembly. These problems are studied with multiple variations and combinations of heuristics and metaheuristics with two distinct types or representations. The majority of the algorithms are built around the Recentering- Restarting Genetic Algorithm. The algorithm variations were successful on all problems studied, and particularly for the two bioinformatics problems. For DNA Error Correction multiple cases were found with 100% of the codes being corrected. The algorithm variations were also able to beat all other state-of-the-art DNA Fragment Assemblers on 13 out of 16 benchmark problem instances.
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UANL
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The objectives were to compare the chemical composition, nutritive value, feed intake, milk production and composition, and presence in milk of transgenic DNA and the encoded protein Cry1Ab when corn silages containing 2 transgenes (2GM: herbicide tolerance: mepsps and insect resistance: cry1Ab) were fed as part of a standard total mixed ration (TMR) compared with a near isogenic corn silage ( C) to 8 multiparous lactating Holstein dairy cows in a single reversal design study. Cows were fed a TMR ration ad libitum and milked twice daily. Diets contained [ dry matter (DM) basis] 45% corn silage, 10% alfalfa hay, and 45% concentrate (1.66 Mcal of net energy for lactation/kg of DM, 15.8% crude protein, 35% neutral detergent fiber, and 4.1% fat). Each period was 28-d long. During the last 4 d of each period, feed intake and milk production data were recorded and milk samples taken for compositional analysis, including the presence of transgenic DNA and Cry1Ab protein. There was no significant difference in the chemical composition between C and 2GM silages, and both were within the expected range (37.6% DM, 1.51 Mcal of net energy for lactation/kg, 8.6% crude protein, 40% neutral detergent fiber, 19.6% acid detergent fiber, pH 3.76, and 62% in vitro DM digestibility). Cows fed the 2GM silage produced milk with slightly higher protein (3.09 vs. 3.00%), lactose ( 4.83 vs. 4.72%) and solids-not-fat (8.60 vs. 8.40%) compared with C. However, the yield (kg/d) of milk (36.5), 3.5% fat-corrected milk (34.4), fat (1.151), protein (1.106), lactose (1.738), and solids-not-fat ( 3.094), somatic cell count (log(10): 2.11), change in body weight (+ 7.8 kg), and condition score (+ 0.09) were not affected by type of silage, indicating no overall production difference. All milk samples were negative for the presence of transgenic DNA from either trait or the Cry1Ab protein. Results indicate that the 2GM silage modified with 2 transgenes did not affect nutrient composition of the silages and had no effect on animal performance and milk composition. No transgenic DNA and Cry1Ab protein were detected in milk.
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The effect of variety, agronomic and environmental factors on the chemical composition and energy value for ruminants and non-ruminants of husked and naked oats grain was studied. Winter oats were grown as experimental plots in each of 2 years on three sites in England. At each site two conventional husked oat cultivars (Gerald and Image) and two naked cultivars (Kynon and Pendragon) were grown. At each site, crops were sown on two dates and all crops were grown with the application of either zero or optimum fertiliser nitrogen. Variety and factors contained within the site + year effect had the greatest influence on the chemical composition and nutritive value of oats, followed by nitrogen ferfiliser treatment. For example, compared with zero nitrogen, the optimum nitrogen fertiliser treatment resulted in a consistent and significant (P < 0.001) increase in crude protein for all varieties at all sites from an average of 95 to 118 g kg(-1) DM, increased the potassium concentration in all varieties from an average of 4.9 to 5.1 g kg(-1) DM (P < 0.01) and reduced total lipid by a small but significant (P < 0.001) amount. Optimum nitrogen increased (P < 0.001) the NDF concentration in the two husked varieties and in the naked variety Pendragon. Naked cultivars were lower in fibre, had considerably higher energy, total lipid, linoleic acid, protein, starch and essential amino acids than the husked cultivars. Thus nutritionists need to be selective in their choice of naked or husked oat depending on the intended dietary use. (C) 2004 Elsevier B.V. All rights reserved.
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Data from 60 multiparous Holstein cows were used in a 12-wk continuous design feeding trial. Cows were allocated to 1 of 4 experimental treatments (T1 to T4). In T1 and T2, the total mixed ration (TMR) contained either corn silage from the genetically modified (GM) variety Chardon Liberty Link, which is tolerant to the herbicide glufosinate ammonium, or its near isogenic nonGM counterpart, whereas the TMR used in T3 and T4 contained corn silage from the commercially available nonGM varieties Fabius and Antares, respectively. The objectives of the study were to determine if the inserted gene produced a marked effect on chemical composition, nutritive value, feed intake, and milk production, and to determine if transgenic DNA and the protein expressed by the inserted gene could be detected in bovine milk. The nutritive value, fermentation characteristics, mineral content, and amino acid composition of all 4 silages were similar. There were no significant treatment effects on milk yield, milk composition, and yield of milk constituents, and the dry matter (DM) intake of the GM variety was not significantly different from the 2 commercial varieties. However, although the DM intake noted for the nonGM near-isogenic variety was similar to the commercial varieties, it was significantly lower when compared with the GM variety. Polymerase chain reaction analyses of milk samples collected at wk 1, 6, and 12 of the study showed that none of the 90 milk samples tested positive, above a detection limit of 2.5 ng of total genomic DNA/mL of milk, for either tDNA (event T25) or the single-copy endogenous Zea mays gene, alcohol dehydrogenase. Using ELISA assays, the protein expressed by the T25 gene was not detected in milk.
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This paper explores concentration levels in the ownership of intellectual property rights over plant varieties worldwide. An analysis of data for 30 UPOV member-countries shows a high degree of concentration in the ownership of plant variety rights for six major crops at the national level in the developed world. Much of this concentration has arisen owing to the rapid consolidation of the seed industry through mergers and acquisitions, especially in the 1990s. A high degree of concentration in the ownership of plant variety rights, in combination with recent efforts to strengthen plant variety protection regimes, is likely to have significant effects on the prospects for future innovation in plant breeding and the distribution of market power between companies. For developing countries, concentration in intellectual property right ownership may have important implications for the structure of domestic seed industries and access to protected varieties and associated plant breeding technologies. These implications for developing countries are likely to become apparent in the context of the rapid spread of plant variety protection and access legislation, emerging changes in the international exchange regime for plant material and liberalised investment policies permitting foreign investment in the seeds sector.
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This paper explores concentration levels in the ownership of intellectual property rights over plant varieties worldwide. An analysis of data for 30 UPOV member-countries shows a high degree of concentration in the ownership of plant variety rights for six major crops at the national level in the developed world. Much of this concentration has arisen owing to the rapid consolidation of the seed industry through mergers and acquisitions, especially in the 1990s. A high degree of concentration in the ownership of plant variety rights, in combination with recent efforts to strengthen plant variety protection regimes, is likely to have significant effects on the prospects for future innovation in plant breeding and the distribution of market power between companies. For developing countries, concentration in intellectual property right ownership may have important implications for the structure of domestic seed industries and access to protected varieties and associated plant breeding technologies. These implications for developing countries are likely to become apparent in the context of the rapid spread of plant variety protection and access legislation, emerging changes in the international exchange regime for plant material and liberalised investment policies permitting foreign investment in the seeds sector. (C) 2003 Elsevier Ltd. All rights reserved.
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Many developing countries are currently engaged in designing and implementing plant variety protection systems. Encouraging private investment in plant breeding is the key rationale for extending intellectual property rights to plant varieties. However, the design of plant variety protection systems in developing countries has been dominated by concerns regarding the inequities of a plant variety protection system, especially the imbalance in the reward structure between plant breeders and farmers. The private seed industry, a key stakeholder in plant variety protection, appears to be playing only a peripheral role in the design of the intellectual property rights regime. This paper explores the potential response of the private seed industry in India to plant variety protection legislation based on a survey of major plant breeding companies. The survey finds that the private seed industry in India is generally unenthusiastic about the legislation and plant variety protection is likely to have only a very limited impact on their research profile and expenditures on plant breeding. Measures designed to curb the 'excessive' profits of breeders, farmers' rights provisions and poor prospects for enforcement of rights are seen to be seriously diluting breeders' rights, leaving few incentives for innovation. If the fundamental objective of plant variety protection is to stimulate private investment in plant breeding, then developing countries need to seriously address the question of improving appropriability of returns from investment.
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Under the Agreement on Trade-Related Aspects of Intellectual Property Rights, all member-countries of the World Trade Organization are required to provide an "effective" system of plant variety protection within a specific time frame. In many developing countries, this has led to a divisive debate about the fundamental desirability of extending intellectual property rights to agriculture. Empirical studies on the economic impacts of plant variety protection, especially its ability to generate large private sector investments in plant breeding and to facilitate the transfer of technology, have been very limited. This paper examines two aspects of the international experience of plant variety protection: (a) the relationship between legislation, research, and development expenditures and plant variety protection grants, i.e., the innovation effect and (b) the role of plant variety protection in facilitating the flow of varieties across countries, i.e., the transferability effect.