Search
Search Results
Sort by
- ArticleMcLaren A.Science. 2000 Jun 09;288(5472):1777.Human cloning has fired the imaginations of many writers since Aldous Huxley published Brave New World in 1932, though no hint of cloning is seen in prior works such as the science fiction writings of H. G. Wells or Mary Shelley's Frankenstein. Where did Huxley's ideas come from?
- ArticleMcGrew WC.Science. 2000 Jun 09;288(5472):1747.
- ArticleStokstad E.Science. 2000 Jun 09;288(5472):1731.Useful as they are for probing subtle features of fossil specimens, computed tomography (CT) scans are equally adept at singling out parts that don't belong. At the University of Texas's CT lab, one researcher has identified mismatches that fooled even expert eyes.
- ArticleStokstad E.Science. 2000 Jun 09;288(5472):1729.To figure out the posture and gait of large dinosaurs, researchers must examine the way their limbs articulate. But that's tough to do when a single meter-long shoulderblade can weigh as much as a bag of cement. Now, thanks to industrial scanning and rapid prototyping, researchers can create replicas that can fit in a briefcase.
- ArticleNormile D.Science. 2000 Jun 09;288(5472):1721.Last week, Chinese scientists presented evidence from a new specimen dug up in Liaoning Province that they say strengthens the case for the bird-dinosaur link. The finding, one of several fossils displayed at a meeting here, is the third known specimen of a strange creature known as Caudipteryx which, unlike any other known dinosaur fossil, shows the unmistakable imprints of feathers. The researcher who described the new specimen at the meeting has identified 16 characteristics of the new fossil that are more similar to dinosaurs than to early birds, reinforcing the views of most Western scientists.
- ArticleKaiser J.Science. 2000 Jun 09;288(5472):1715.
- ArticlePennisi E.Science. 2000 Jun 09;288(5472):1726.In 1998, an anonymous millionaire, hoping to clone his pet dog Missy, awarded a Texas A&M University animal scientist $2.3 million to develop the necessary techniques. Now several companies are cashing in on the boom in frozen-tissue storage of pets for future cloning.
- ArticleFarr NL.Science. 2000 Jun 09;288(5472):1747.
- ArticleMcLaren A.Science. 2000 Jun 09;288(5472):1778.Embryonic stem cells, which have the potential to become any type of cell in the body, could one day provide a readily available supply of any tissue for the repair of damaged or diseased organs. But because they are derived from early human embryos, their use raises ethical problems.
- ArticleGaskell G, Bauer M, Durant J, Allum N.Science. 2000 Jun 09;288(5472):1751.
- ArticleMcGrew WC.Science. 2000 Jun 09;288(5472):1747b.
- ArticleKaiser J.Science. 2000 Jun 09;288(5472):1715a.Even before the first genetic sequence of a flowering plant, a wild mustard called Arabidopsis thaliana, is completed, a group of plant scientists has hatched an ambitious plan for the next phase: figuring out the functions of all 25,000 genes. Announced last week, the plan, which has the blessing of the National Science Foundation, came with another bit of good news for the Arabidopsis community: the unexpected release of a set of molecular markers for finding those genes.
- ArticleFarr NL.Science. 2000 Jun 09;288(5472):1747c.
- ArticleHillis DM.Science. 2000 Jun 09;288(5472):1757-9.Establishing the date when immunodeficiency viruses were transmitted from nonhuman primates to humans should provide a clue to the origin of the AIDS pandemic. In his Perspective, Hillis discusses an important analysis of the molecular divergence of SIV and HIV genes (Korber et al.). This analysis establishes 1931 as the date of origin of the HIV-1 M-group viruses (the principal cause of the AIDS pandemic). Hillis discusses three possible hypotheses of immunodeficiency virus transmission that are consistent with this date.
- ArticlePennisi E, Vogel G.Science. 2000 Jun 09;288(5472):1722-7.Often left out of news reports of cloned animals is the fact that for every 100 attempts, just two or three live offspring typically result. Now many researchers are going back to the lab to attempt to find out why. They are probing fundamental questions of cell biology, as well as trying to figure out whether there is something inherently flawed in "asexual" reproduction in mammals, or whether some problem lies in the in vitro component of the process. For now, the serious obstacles suggest that human cloning may be a long way off.
- ArticleScholl A.Science. 2000 Jun 09;288(5472):1762-3.The drive to smaller and smaller computational devices demands control over the structure, composition, and magnetic properties of materials on a sub-100-nanometer scale. In his Perspective, Scholl highlights a report by Heinze et al., who have been able to image an antiferromagnetic Mn monolayer at atomic resolution using a technique called spin-polarized scanning tunneling microscopy. Because of its unrivaled resolution, this technique is likely to provide insights into magnetic interactions that are of fundamental importance to magnetic devices.
- ArticleXu RX, Hassell AM, Vanderwall D, Lambert MH, Holmes WD, Luther MA, Rocque WJ, Milburn MV, Zhao Y, Ke H, Nolte RT.Science. 2000 Jun 09;288(5472):1822-5.Cyclic nucleotides are second messengers that are essential in vision, muscle contraction, neurotransmission, exocytosis, cell growth, and differentiation. These molecules are degraded by a family of enzymes known as phosphodiesterases, which serve a critical function by regulating the intracellular concentration of cyclic nucleotides. We have determined the three-dimensional structure of the catalytic domain of phosphodiesterase 4B2B to 1.77 angstrom resolution. The active site has been identified and contains a cluster of two metal atoms. The structure suggests the mechanism of action and basis for specificity and will provide a framework for structure-assisted drug design for members of the phosphodiesterase family.
- ArticlePennisi E.Science. 2000 Jun 09;288(5472):1717-8.Biomechanists have uncovered the secret of how the gecko manages to run up walls and across ceilings: rows of tiny hairs with multiple split ends on the bottom of each toe pad. As they report in the 8 June issue of Nature, weak attractive forces between the 1000 or so split ends on each hair and the ceiling help the gecko grab even the smoothest surface. Armed with that knowledge, the researchers hope to design synthetic "footpads" to improve the maneuverability of robots and perhaps to design an entirely new type of adhesive.
- ArticleMarshall E.Science. 2000 Jun 09;288(5472):1715-7.