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We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of(More)
We review a striking array of recent experiments and their theoretical interpretations on the superfluid transition in 4 He in the presence of a heat flux Q. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If Q is in the(More)
The article that follows was written in 1994, and first appeared in The American Scholar (vol. 63 p. 527). In the three years since then much has happened, but little has changed. There have been reports of increasingly reliable production of excess heat, and of the detection of 4 He residue, and much more. Nevertheless, the most remarkable fact remains(More)
We present the first experimental evidence that the heat capacity of superfluid 4 He, at temperatures very close to the lambda point T l , is enhanced by a constant heat flux Q. The heat capacity at constant Q, C Q , is predicted to diverge at a temperature T c ͑Q͒ , T l at which superflow becomes unstable. In agreement with previous measurements, we find(More)
We review a striking array of recent experiments, and their theoretical interpretations, on the superfluid transition in 4 He in the presence of a heat flux, Q. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If Q is in the(More)
We discuss aspects of the theory of critical phenomena and explore the superfluid transition in 4 He. We review some of the recent experimental and theoretical work on helium in nonequilibrium conditions and summarize some future space experiments that might shed light on disagreements between theory and experiment.