2,581 research outputs found

    The replication of DNA in Escherichia coli

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    Studies of bacterial transformation and bacteriaphage infection (1-5) strongly indicate that deoxyribonucleic acid (DNA) can carry and transmit hereditary information and can direct its own replication. Hypotheses for the mechanism of DNA replication differ in the predictions they make concerning the distribution among progeny molecules of atoms derived from parental molecules.(6

    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 144

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    This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

    Aerospace Medicine and Biology

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    This bibliography lists 184 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during October 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Aerospace Medicine and Biology: a Continuing Bibliography with Indexes (supplement 330)

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    This bibliography lists 156 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System during November 1989. Subject coverage includes: aerospace medicine and psychology, life support system and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Bringing maker practices to school : tracing discursive and materially mediated aspects of student teams' collaborative making processes

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    The present investigation aimed to analyze the collaborative making processes and ways of organizing collaboration processes of five student teams. As a part of regular school work, the seventh-grade students were engaged in the use of traditional and digital fabrication technologies for inventing, designing, and making artifacts. To analyze complex, longitudinal collaborative making processes, we developed the visual Making-Process-Rug video analysis method, which enabled tracing intertwined with social-discursive and materially mediated making processes and zoomed in on the teams' efforts to organize their collaborative processes. The results indicated that four of the five teams were able to take on multifaceted epistemic and fabrication-related challenges and come up with novel co-inventions. The successful teams' social-discursive and embodied making actions supported each another. These teams dealt with the complexity of invention challenges by spending a great deal of their time in model making and digital experimentation, and their making process progressed iteratively. The development of adequate co-invention and well-organized collaboration processes appeared to be anchored in the team's shared epistemic object.Peer reviewe

    Aeronautical engineering: A special bibliography with indexes, supplement 82, April 1977

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    This bibliography lists 311 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1977
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