863 resultados para To-monomer Transformation


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Plasmodium falciparum malaria parasites were transformed with plasmids containing P. falciparum or Toxoplasma gondii dihydrofolate reductase-thymidylate synthase (dhfr-ts) coding sequences that confer resistance to pyrimethamine. Under pyrimethamine pressure, transformed parasites were obtained that maintained the transfected plasmids as unrearranged episomes for several weeks. These parasite populations were replaced after 2 to 3 months by parasites that had incorporated the transfected DNA into nuclear chromosomes. Depending upon the particular construct used for transformation, homologous integration was detected in the P. falciparum dhfr-ts locus (chromosome 4) or in hrp3 and hrp2 sequences that were used in the plasmid constructs as gene control regions (chromosomes 13 and 8, respectively). Transformation by homologous integration sets the stage for targeted gene alterations and knock-outs that will advance understanding of P. falciparum.

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Prolonged incubation of NIH 3T3 cells under the growth constraint of confluence results in the death of some cells in a manner suggestive of apoptosis. Successive rounds of prolonged incubation at confluence of the surviving cells produce increasing neoplastic transformation in the form of increments in saturation density and transformed focus formation. Cells from the postconfluent cultures are given a recovery period of various lengths to remove the direct inhibitory effect of confluence before their growth properties are studied. It is found that with each round of confluence the exponential growth rate of the cells at low densities gets lower and the size of isolated colonies of the same cells shows a similar progressive reduction. The decreased growth rate of cells from the third round of confluence persists for > 60 generations of growth at low density. The proportion of colonies containing giant cells is much higher after a 2-day recovery from confluence than after a 7-day recovery. Retardation of growth at low density and increased saturation density appear to be two sides of the same coin: both occur in the entire population of cells and precede the formation of transformed foci. We propose that the slowdown in growth and the formation of giant cells result from heritable damage to the cells, which in turn drives their transformation. Similar results have been reported for the survivors of x-irradiation and of treatment with chemical carcinogens and are associated with the aging process in animals. We suggest that these changes result from free radical damage to membrane lipids with particular damage to lysosomes. Proteases and nucleases would then be released to progressively modify the growth behavior and genetic stability of the cells toward autonomous proliferation.

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The European Union’s leadership spent the last five years fighting an acute and existential crisis. The next five years, under your leadership, will be no less difficult. You will have to tackle difficult economic and institutional questions while being alert to the possibility of a new crisis. You face three central challenges: (1) The feeble economic situation prevents job creation and hobbles attempts to reduce public and private debt; (2) EU institutions and the EU budget need reform and you will have to deal with pressing external matters, including neighbourhood policy and the EU’s position in the world; (3) You will have to prepare and face up to the need for treaty change to put monetary union on a more stable footing, to review the EU’s competences and to re-adjust the relationship between the euro area and the EU, and the United Kingdom in particular.

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In recent years, Ukraine’s agriculture has been consistently improving and has been the only part of the country’s economy to buck the recession. According to preliminary estimates, in 2013 agricultural production increased by 13.7% - in contrast to a 4.7% decline in the industrial sector. According to official statistics, Ukraine’s industrial production was up 40% in the final months of 2013 when compared to the same period of 2012. This translated into an unexpected gain in fourth-quarter GDP growth (+3.7%) and prevented an annual drop in GDP. Crop production, and particularly the production of grain, hit a record high: in 2013, Ukraine produced 63 million tonnes of grain, outperforming its best ever harvest of 2011 (56.7 million tonnes). The value of Ukraine’s agricultural and food exports increased from US$4.3 billion in 2005 to US$17.9 billion in 2012, and currently accounts for a quarter of Ukraine’s total exports. Economic forecasts suggest that in the current marketing year (July 2013 - June 2014) Ukraine will sell more than 30 million tonnes of grain to foreign markets, making it the world’s second biggest grain exporter, after the United States.

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relrank generates the so called (quasi-) relative data of a variable compared to an empirical reference distribution. This is also called the grade transformation.

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"August 1980."

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There is growing urgency to enhance the sustainability of existing and emerging cities. The science of ecology, especially as it interacts with disciplines in the social sciences and urban design, has contributions to make to the sustainable transformation of urban systems. Not all possible urban transformations may lead toward sustainability. Ecological science helps identify components of resilience that can favor transformations that are more sustainable. To summarize the dynamics and choices involved in sustainable transformations, a “metacity” framework is presented, embracing ecological processes in cities as complementary to those involving society, power, and economy.

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This paper chronicles White South African journalist Donald Woods’ life (1933-2001) as he transformed from holding racist beliefs that Blacks were “people who were there to be your servants,” to becoming one of his country’s leading anti-apartheid activists. Adult learning and development via perspective transformation theory are explored.

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The emergence of grassroots social movements variously preoccupied with a range of external threats, such as diminishing supplies of fossil energy or climate change, has led to increased interest in the production of local food. Drawing upon the notion of cognitive praxis, this article utilises transition as a trajectory guided by an overarching cosmology that brings together a broad social movement seeking a more resilient future. This ‘grand narrative’ is reinforced by ‘transition movement intellectuals’ who serve to shape an agenda of local preparedness in the face of uncertainty, rather than structural analysis of the global system. In this context, growing and producing food offers important multi-functional synergies by reconnecting people to place and its ecological endowments and serves to provide a vital element in civic mobilisation. Yet, local food could also become a means to build international solidarity in defence of food sovereignty and establish a global coalition opposed to the corporate agri-food agenda of biotechnologies, land grabbing and nutritional impoverishment.

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Several different acquired resistance mechanisms of EGFR mutant lung adenocarcinoma to EGFR-tyrosine kinase inhibitor (TKI) therapy have been described, most recently transformation to small cell lung carcinoma (SCLC). We describe the case of a 46-year-old female with relapsed EGFR exon 19 deletion lung adenocarcinoma treated with erlotinib, and on resistance, cisplatin-pemetrexed. Liver rebiopsy identified an afatinib-resistant combined SCLC and non-small cell carcinoma with neuroendocrine morphology, retaining the EGFR exon 19 deletion. This case highlights acquired EGFR-TKI resistance through transformation to the high-grade neuroendocrine carcinoma spectrum and that that such transformation may not be evident at time of progression on TKI therapy.

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To define specific pathways important in the multistep transformation process of normal plasma cells (PCs) to monoclonal gammopathy of uncertain significance (MGUS) and multiple myeloma (MM), we have applied microarray analysis to PCs from 5 healthy donors (N), 7 patients with MGUS, and 24 patients with newly diagnosed MM. Unsupervised hierarchical clustering using 125 genes with a large variation across all samples defined 2 groups: N and MGUS/MM. Supervised analysis identified 263 genes differentially expressed between N and MGUS and 380 genes differentially expressed between N and MM, 197 of which were also differentially regulated between N and MGUS. Only 74 genes were differentially expressed between MGUS and MM samples, indicating that the differences between MGUS and MM are smaller than those between N and MM or N and MGUS. Differentially expressed genes included oncogenes/tumor-suppressor genes (LAF4, RB1, and disabled homolog 2), cell-signaling genes (RAS family members, B-cell signaling and NF-kappaB genes), DNA-binding and transcription-factor genes (XBP1, zinc finger proteins, forkhead box, and ring finger proteins), and developmental genes (WNT and SHH pathways). Understanding the molecular pathogenesis of MM by gene expression profiling has demonstrated sequential genetic changes from N to malignant PCs and highlighted important pathways involved in the transformation of MGUS to MM.