58 research outputs found

    Gecko CD59 Is Implicated in Proximodistal Identity during Tail Regeneration

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    Several adult reptiles, such as Gekko japonicus, have the ability to precisely re-create a missing tail after amputation. To ascertain the associated acquisition of positional information from blastemal cells and the underlying molecular mechanism of tail regeneration, a candidate molecule CD59 was isolated from gecko. CD59 transcripts displayed a graded expression in the adult gecko spinal cord with the highest level in the anterior segment, with a stable expression along the normal tail. After tail amputation, CD59 transcripts in the spinal cord proximal to the injury sites increased markedly at 1 day and 2 weeks; whereas in the regenerating blastema, strong CD59 positive signals were detected in the blastemal cells anterior to the blastema, with a gradual decrease along the proximodistal (PD) axis. When treated with RA following amputation, CD59 transcripts in the blastema were up-regulated. PD confrontation assays revealed that the proximal blastema engulfed the distal one after in vitro culture, and rabbit-anti human CD59 antibody was able to block this PD engulfment. Overexpression of the CD59 during tail regeneration causes distal blastemal cells to translocate to a more proximal location. Our results suggest that position identity is not restricted to amphibian limb regeneration, but has already been established in tail blastema of reptiles. The CD59, a cell surface molecule, acted as a determinant of proximal–distal cell identity

    The importance of open and closed styles of energy research

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    This paper explores the styles of research associated with wind turbines, ethanol and fuel cells in six countries. The concept of a ‘research style’ emphasizes that values and interests, along with deeper historical and cultural influences, shape research and get built into technology. Open research styles are epitomized by a broad inclusion of actors in the research process, participatory ownership of its results, cooperation among stakeholders and users, and experimentation and flexibility. Closed research styles are distinguished by limited access and ownership, competition among researchers, centralization of the research process and rigidity in dictating programme goals and preferences. The paper uses the concept of open and closed research styles to compare the experiences of Denmark, Brazil and China (open) with those in the USA, France and Norway (closed)

    The return of the Phoenix: the 1963 International Congress of Zoology and American zoologists in the twentieth century

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    This paper examines the International Congress of Zoology held in Washington D.C. in 1963 as a portrait of American zoologists’ search for effective and rewarding relationships with both each other and the public. Organizers of the congress envisioned the congress as a last ditch effort to unify the disparate subdisciplines of zoology, overcome the barriers of specialization, and ward off the heady claims of more reductionist biologists. The problems zoologists faced as they worked to fulfill these ambitious goals illuminate some of the challenges faced by members of the naturalist tradition as they worked to establish disciplinary unity while seeking public support in the competitive world of twentieth century science
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