1,968 research outputs found

    Using photo-elicitation to explore social representations of community multimedia centers in Mozambique.

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    Ten Mozambican Community Multimedia Centers (CMCs) were investigated by analyzing Social Representations of users and staff members. Photo-elicitation, an underexplored methodological approach in the domain of Information and Communication Technologies for Development (ICT4D), was employed to conduct the study, and a three-step qualitative content analysis was performed on both visual and textual data. Results tend to confirm and build upon outcomes from the existing literature on Public Access Venues (PAVs). Local communities value these centers because they bring social recognition to people working or learning there. The venues are associated with a symbolism that extends from the social recognition of the individual to the development and social inclusion of the whole community, which, because of the presence of the venue, does not feel left behind. In this vein, the study also shows that the importance of CMCs is often not related to the newest technology available, but to the technology that reaches the most of the community. The study also highlights neglected dimensions of CMCs, such as the importance of the exterior appearance of the venue, and the perception of a switch in their nature from static centers funded by third parties towards more entrepreneurial-driven ones. The presented research also contributes to the ICT4D field by proposing a promising research protocol, which is able to elicit representations otherwise difficult to obtain

    Overexpression of ultraconserved region 83-induces lung cancer tumorigenesis

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    The expression of non–coding RNAs (ncRNAs) is dysregulated in human cancers. The transcribed ultraconserved regions (T-UCRs) express long ncRNAs involved in human carcinogenesis. T-UCRs are non-coding genomic sequence that are 100% conserved across humans, rats and mice. Conservation of genomic sequences across species intrinsically implies an essential functional role and so we considered the expression of T-UCRs in lung cancer. Using a custom microarray we analyzed the global expression of T-UCRs. Among these T-UCRs, the greatest variation was observed for antisense ultraconserved element 83 (uc.83-), which was upregulated in human lung cancer tissues compared with adjacent non cancerous tissues. Even though uc.83- is located within the long intergenic non-protein coding RNA 1876 (LINC01876) gene, we found that the transcribed uc.83- is expressed independently of LINC01876 and was cloned as a 1143-bp RNA gene. In this study, functional analysis confirmed important effects of uc.83- on genes involved in cell growth of human cells. siRNA against uc.83- decreased the growth of lung cancer cells while the upregulation through a vector overexpressing the uc.83- RNA increased cell proliferation. We also show the oncogenic function of uc.83- is mediated by the phosphorylation of AKT and ERK 1/2, two important biomarkers of lung cancer cell proliferation. Based on our findings, inhibition against uc.83- could be a future therapeutic treatment for NSCLC to achieve simultaneous blockade of pathways involved in lung carcinogenesis

    Exploring the meanings of community multimedia centers in Mozambique : a social representations perspective

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    This article presents extensive research conducted in Mozambique that aims to deeply understand how different social groups understand community multimedia centers (CMCs), which are structures combining a community radio and a telecenter. The social representations theory was adopted to interpret narratives of 231 interviewees from 10 Mozambican provinces. Interviewees included representatives of initiating agencies, local staff members, CMC users (both the radio and telecenter components), users of only the community radio, and community members not using the CMCs. Following the analysis of transcribed interviews, six main clusters were identified, each of them shedding light on a specific understanding of a CMC. These are discussed according to a set of sociodemographic variables. This study suggests that the social representations theory is a valuable framework to provide an integrated view of ICT4D interventions by giving a voice to local perspectives without overlooking the initiating agencies’ expectations

    Efficiency of transient transformation in tobacco protoplasts is independent of plasmid amount

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    An optimized protocol for the transient transformation of tobacco protoplasts mediated by polyethylene\u2013glycol (PEG) is here described. As expected, the quantitative b\u2013glucuronidase (Gus) activity driven by pCaMVGus was dependent on the amount of plasmid used. Nevertheless, we demonstrate by an immunodetection method that transformation efficiency did not depend on the amount of plasmid used but on the limitation imposed by cell competence. In fact, we obtained the same percentage of transformed cells (about 60%) using a wide range of plasmid concentrations (0.1\u201310 mg per test). Finally, we show that, when we used two plasmid types in a mixture at a concentration ranging from 0.1 to 10 mg for each, all transformed cells expressed proteins encoded by both plasmids. Transient expression and co-transformation experiments are routinely used methods and, probably, the major results from this work were assumed by many researchers in this field, but our data experimentally support this assumption

    Antisense reduction of thylakoidal ascorbate peroxidase in Arabidopsis enhances Paraquat-induced photooxidative stress and Nitric Oxide-induced cell death

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    The production and characterization of Arabidopsis plants containing a transgene in which the Arabidopsis tAPX is inserted in antisense orientation, is described. tAPX activity in these transgenic tAPX plants is around 50% of control level. The tAPX antisense plants are phenotypically indistinguishable from control plants under normal growth conditions; they show, however, enhanced sensitivity to the O 2- -generating herbicide, Paraquat. Interestingly, the tAPX antisense plants show enhanced symptoms of damage when cell death is triggered through treatment with the nitric oxide-donor, SNP. These results are in accordance with the ones recently obtained with transgenic plants overexpressing tAPX; altogether, they suggest that tAPX, besides the known ROS scavenging role, is also involved in the fine changes of H 2O2 concentration during signaling events

    Thermodynamical features of multifragmentation in peripheral Au + Au Collisions at 35 A.MeV

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    The distribution of fragments produced in events involving the multifragmentation of excited sources is studied for peripheral Au + Au reactions at 35 A.MeV. The Quasi-Projectile has been reconstructed from its de-excitation products. An isotropic emission in its rest frame has been observed, indicating that an equilibrated system has been formed. The excitation energy of the Quasi-Projectile has been determined via calorimetry. A new event by event effective thermometer is proposed based on the energy balance. A peak in the energy fluctuations is observed related to the heat capacity, suggesting that the system undergoes a liquid-gas type phase transition at an excitation energy about 5 A.MeV and a temperature 4 - 6 MeV, dependent on the freeze-out hypothesis. By analyzing different regions of the Campi-plot, the events associated with the liquid and gas phases as well as the critical region are thermodynamically characterized. The critical exponents, tau, beta,gamma, extracted from the high moments of the charge distribution are consistent with a liquid-gas type phase transition.Comment: 44 pages, 16 Postscript figures, Fig14_nucl-ex.eps in colors, to be published in Nucl.Phys.A (1999

    Overexpression of Osmyb4 enhances compatible solute accumulation and increases stress tolerance of arabidopsis thaliana

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    In this paper, we report the metabolic and molecular changes in response to cold and drought induced in Osmyb4 transgenic Arabidopsis thaliana compared with the wildtype (WT). The rice Osmyb4 gene codes for a transcription factor (Myb4) induced by cold treatment and, in Arabidopsis transgenic plants, improves cold and freezing tolerance [Vannini C, Locatelli F, Bracale M, Magnani E, Marsoni M, Osnato M, Mattana M, Baldoni E, Coraggio I (2004) Plant J 37: 115-127]. Here, we report the ability of Myb4 to induce also drought tolerance in Arabidopsis transgenic plants. By the use of nuclear magnetic resonance (NMR) and enzymatic assays, we showed that several compatible solutes (glucose, fructose, sucrose, proline, glycine betaine and sinapoyl malate) accumulate in higher amount in Osmyb4-overexpressing plants with respect to the WT, both under normal and stress conditions. Considering proline, we also found that in transgenic plants the levels of the mRNAs coding for \u3941- pyrroline-5-carboxylate synthase (EC not assigned) and for \u3941- pyrroline-5-carboxylate dehydrogenase (EC 1.5.1.12) were higher and lower, respectively. The constitutive activation of several stress-inducible pathways and different kinetics in the accumulation of several metabolites, in Myb4 transgenic plants, may represent an advantage to prepare plants to face the stress condition. Moreover, these results taken together suggest that Myb4 integrates the activation of multiple components of stress response

    Negative heat capacity in the critical region of nuclear fragmentation: an experimental evidence of the liquid-gas phase transition

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    An experimental indication of negative heat capacity in excited nuclear systems is inferred from the event by event study of energy fluctuations in AuAu quasi-projectile sources formed in Au+AuAu+Au collisions at 35 A.MeV. The excited source configuration is reconstructed through a calorimetric analysis of its de-excitation products. Fragment partitions show signs of a critical behavior at about 5 A.MeV excitation energy. In the same energy range the heat capacity shows a negative branch providing a direct evidence of a first order liquid gas phase transition.Comment: 4 Postscript figures, submitted to Phys. Rev. Lett. on 14-apr-199
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