857 resultados para Bridging


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Lodestar, a Drosophila maternal-effect gene, is essential for proper chromosome segregation during embryonic mitosis. Mutations in lodestar cause chromatin bridging in anaphase, preventing the sister chromatids from fully separating and leaving chromatin tangled at the metaphase plate. Drosophila lodestar protein was originally identified, in purified fractions of Drosophila Kc cell nuclear extracts, by its ability to suppress the generation of long RNA polymerase II transcripts. The human homolog of this protein (hLodestar) was cloned and studied in comparison to the Drosophila lodestar activities. The results of these studies show, similar to the Drosophila protein, hLodestar has dsDNA-dependent ATPase and transcription termination activity in vitro. hLodestar has also been shown to release RNA polymerase I and II stalled at a cyclobutane thymine dimer. Lodestar belongs to the SNF2 family of proteins, which are members of the DExH/D helicase super-family. The SNF2 family of proteins are believed to play a critical role in altering protein-DNA interactions in a variety of cellular contexts. We have recently isolated a human cDNA (hLodestar) that shares significant homology to the Drosophila lodestar gene. The 4.6 kb clone contains an open reading frame of 1162 amino acids, and shares 55% similarity and 46% identity to the Drosophila Lodestar protein sequence. Our studies looking for hLodestar interacting proteins revealed an association with CDC5L in the yeast two-hybrid system and co-immunoprecipitation experiments. CDC5L has been well documented to be a component of the spliceosome. Our data suggests hLodestar is involved in splicing through in vitro assembly and splicing reactions, in addition to its association with spliceosomes purified from HeLa nuclear extract. Although many other members of the DExH/D helicase super-family have been linked to splicing, this is the first SNF2 family member to be implicated in the splicing reaction. ^

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An unusual polyketide with a new carbon skeleton, lindgomycin (1), and the recently described ascosetin (2) were extracted from mycelia and culture broth of different Lindgomycetaceae strains, which were isolated from a sponge of the Kiel Fjord in the Baltic Sea (Germany) and from the Antarctic. Their structures were established by spectroscopic means. In the new polyketide, two distinct domains, a bicyclic hydrocarbon and a tetramic acid, are connected by a bridging carbonyl. The tetramic acid substructure of compound 1 was proved to possess a unique 5-benzylpyrrolidine-2,4-dione unit. The combination of 5-benzylpyrrolidine-2,4-dione of compound 1 in its tetramic acid half and 3-methylbut-3-enoic acid pendant in its decalin half allow the assignment of a new carbon skeleton. The new compound 1 and ascosetin showed antibiotic activities with IC50 value of 5.1 (±0.2) µM and 3.2 (±0.4) µM, respectively, against methicillin-resistant Staphylococcus aureus.

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We present a new dataset of geographical production-, final (embodied) production-, and consumption-based carbon dioxide emission inventories, covering 78 regions and 55 sectors from 1997 to 2011. We extend previous work both in terms of time span and in bridging from geographical to embodied production and, ultimately, to consumption. We analyse the recent evolution of emissions, the development of carbon efficiency of the global economy, and the role of international trade. As the distribution of responsibility for emissions across countries is key to the adoption and implementation of international environmental agreements and regulations, the final production- and consumption-based inventories developed here provide a valuable extension to more traditional geographical production-based criteria.

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This paper explores the possibilities of two unique Japanese concepts - the One Village One Product Movement (OVOP) and Michino Eki (or Roadside Stations) - as potential tools for bridging the gap between cities and rural areas through community-driven development. From the viewpoint of spatial economics and endogenous growth theory, this paper considers both OVOP and Michino Eki as rural development strategies of a broader nature based on "brand agriculture." Here, brand agriculture represents a general strategy for community-based rural development that identifies, cultivates and fully utilizes local resources for the development of products or services unique to a certain "village." Selected examples of OVOP and Michino Eki from Japan and developing countries are introduced.

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We have determined the cross-section σ for color center generation under single Br ion impacts on amorphous SiO2. The evolution of the cross-sections, σ(E) and σ(Se), show an initial flat stage that we associate to atomic collision mechanisms. Above a certain threshold value (Se > 2 keV/nm), roughly coinciding with that reported for the onset of macroscopic disorder (compaction), σ shows a marked increase due to electronic processes. In this regime, a energetic cost of around 7.5 keV is necessary to create a non bridging oxygen hole center-E′ (NBOHC/E′) pair, whatever the input energy. The data appear consistent with a non-radiative decay of self-trapped excitons.

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Problem-based learning has been applied over the last three decades to a diverse range of learning environments. In this educational approach, different problems are posed to the learners so that they can develop different solutions while learning about the problem domain. When applied to conceptual modelling, and particularly to Qualitative Reasoning, the solutions to problems are models that represent the behaviour of a dynamic system. The learner?s task then is to bridge the gap between their initial model, as their first attempt to represent the system, and the target models that provide solutions to that problem. We propose the use of semantic technologies and resources to help in bridging that gap by providing links to terminology and formal definitions, and matching techniques to allow learners to benefit from existing models.

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Survey Engineering curricula involves the integration of many formal disciplines at a high level of proficiency. The Escuela de Ingenieros en Topografía, Cartografía y Geodesia at Universidad Politécnica de Madrid (Survey Engineering) has developed an intense and deep teaching on so-called Applied Land Sciences and Technologies or Land Engineering. However, new approaches are encouraged by the European Higher Education Area (EHEA). This fact requires a review of traditional teaching and methods. Furthermore, the new globalization and international approach gives new ways to this discipline to teach and learn about how to bridge gap between cultures and regions. This work is based in two main needs. On one hand, it is based on integration of basic knowledge and disciplines involved in typical Survey Engineering within Land Management. On the other, there is an urgent need to consider territory on a social and ethical basis, as far as a part of the society, culture, idiosyncrasy or economy. The integration of appropriate knowledge of the Land Management is typically dominated by civil engineers and urban planners. It would be very possible to integrate Survey Engineering and Cooperation for Development in the framework of Land Management disciplines. Cooperation for Development is a concept that has changed since beginning of its use until now. Development projects leave an impact on society in response to their beneficiaries and are directed towards self-sustainability. Furthermore, it is the true bridge to reduce gap between societies when differences are immeasurable. The concept of development has also been changing and nowadays it is not a purely economic concept. Education, science and technology are increasingly taking a larger role in what is meant by development. Moreover, it is commonly accepted that Universities should transfer knowledge to society, and the transfer of knowledge should be open to countries most in need for developing. If the importance of the country development is given by education, science and technology, knowledge transfer would be one of the most clear of ways of Cooperation for Development. Therefore, university cooperation is one of the most powerful tools to achieve it, placing universities as agents of development. In Spain, the role of universities as agents of development and cooperation has been largely strengthened. All about this work deals to how to implement both Cooperation for Development and Land Management within Survey Engineering at the EHEA framework.

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A model of the mammalian retina and the behavior of the first layers in the visual cortex is reported. The building blocks are optically programmable logic cells. A model of the retina, similar to the one reported by Dowling (1987) is presented. From the model of the visual cortex obtained, some types of symmetries and asymmetries are possible to be detected

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Replication Data Management (RDM) aims at enabling the use of data collections from several iterations of an experiment. However, there are several major challenges to RDM from integrating data models and data from empirical study infrastructures that were not designed to cooperate, e.g., data model variation of local data sources. [Objective] In this paper we analyze RDM needs and evaluate conceptual RDM approaches to support replication researchers. [Method] We adapted the ATAM evaluation process to (a) analyze RDM use cases and needs of empirical replication study research groups and (b) compare three conceptual approaches to address these RDM needs: central data repositories with a fixed data model, heterogeneous local repositories, and an empirical ecosystem. [Results] While the central and local approaches have major issues that are hard to resolve in practice, the empirical ecosystem allows bridging current gaps in RDM from heterogeneous data sources. [Conclusions] The empirical ecosystem approach should be explored in diverse empirical environments.