816 resultados para technological transformation
Resumo:
Chronic myeloid leukemia (CML) is a rare disease in childhood which is almost exclusively associated with bcr-abl p210 (M-bcr) rearrangements. It has been suggested that co-expression of p 190 and p210 may be a pathway of CML progression in adult patients. We report two cases of pediatric patients with a diagnosis of CML who presented co-expression of the p210 and p190 transcripts during progression to the blastic phase. The present data suggest that p190 may be a secondary event in at least some cases of childhood CML, suggesting an association with progression to a blastic crisis in these patients. (c) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Transgenic plants of the model legume Lotus japonicus were regenerated by hypocotyl transformation using a bar gene as a selectable marker. The bar encodes for Phosphinothricin Acetyl Transferase that detoxifies phosphinothricin (PPT), the active ingredient of herbicides such as Ignite (AgrEvo) and Basta (Hoechst). Transgenic L. japonicus plants resistant to PPT were positive upon PCR by bar gene-specific primers. In 5 out of 7 independent lines tested, PPT resistance segregated as a single dominant allele indicating a single T-DNA insertion into the plant genome. All regenerated plants were fertile and void of visible somaclonal abnormalities contrary to 14% infertility when antibiotic selectable markers were used. The lack of somaclonal variation, ease of PPT application and low cost of PPT makes this protocol an attractive alternative for the regeneration of transgenic L. japonicus. The production of PPT herbicide-resistant L. japonicus plants may have significant commercial applications in crop production.
Resumo:
From the mid-1970s through the 1980s and into the 1990s, wage inequality and skill differentials in earnings and employment increased sharply in OECD countries. After 1973 and especially in the 1980s, the US experienced a dismal real wage performance for the less skilled. Among the factors singled out by economists as possible major contributors to this development are economic globalisation processes and skill-biased technological change. Although these are most commonly considered as independent influences, after critically outlining views about these factors, this article argues that strong interdependence exists between them. The article then examines potential policy responses to this growing inequality.
Resumo:
We evaluated the efficiency of callus induction and plantlet regeneration from hypocotyl explants of broccoli (Brassica oleracea var. italica). The cultivars were ‘Marathon’, ‘Greenbelt’, and ‘Shogun’. Transformation success was not affected by the presence of tobacco feeder-cell layers on the culture media. The frequency of shoot regeneration was greater from 10-d-old hypocotyls than from 14-d-old hypocotyls. Both ‘Marathon’ and ‘Greenbelt’ had higher potentials for tissue regeneration than did ‘Shogun’. We found that for transformation selection, the optimum concentration was either 50 mg/L kanamycin or 100 mg/L genetkin.
Resumo:
In recent years, studies on environmental samples with unusual dibenzo-p-dioxin (PCDD) congener profiles were reported from a range of countries. These profiles, characterized by a dominance of octachlorinated dibenzodioxin (OCDD) and relatively low in dibenzofuran (PCDF) concentrations, could not be attributed to known sources or formation processes. In the present study, the processes that result in these unusual profiles were assessed using the concentrations and isomer signatures of PCDDs from dated estuarine sediment cores in Queensland, Australia. Increases in relative concentrations of lower chlorinated PODS and a relative decrease of OCDD were correlated with time of sediment deposition. Preferred lateral, anaerobic dechlorination of OCDD represents a likely pathway for these changes. In Queensland sediments, these transformations result in a distinct dominance of isomers fully chlorinated in the 1,4,6,9-positions (1,4-patterns), and similar 1,4-patterns were observed in sediments from elsewhere. Consequently, these environmental samples may not reflect the signatures of the original source, and a reevaluation of source inputs was undertaken. Natural formation of PCDDs, which has previously been suggested, is discussed; however, based on the present results and literature comparisons, we propose an alternative scenario. This scenario hypothesizes that an anthropogenic PCDD precursor input (e.g. pentachlorophenol) results in the contamination. These results and hypothesis imply further investigations are warrented into possible anthropogenic sources in areas where natural PCDD formation has been suggested.