scientific american - 1993 11 - reading the genes of extinct species

... people in the U.S. The factor may be associated with about 80 percent of the cases of the ill- ness. IdentiÞcation of the factor, a form of a gene responsible for the manufac- ture of a lipoprotein, ... economic poli- cies: the eÛcient allocation of resourc- es, the fair distribution of resources and the maintenance of a sustainable scale of resource use....

Ngày tải lên: 12/05/2014, 14:50

... critical the aÝected pro- cesses are at the time of their disregula- tion and the ability of the organism ei- ther to compensate for or to repair the damage. If the damage disrupts the reg- ulation of ... stable, the high birth rates of the baby boom postponed the aging of the population by widen- ing the base of the age structure again. As the baby boo...

Ngày tải lên: 12/05/2014, 14:49

... ones. Determining the relative ages of the halo and disk reveals much about the sequence of the formation of the gal- axy. On the other hand, it leaves open the question of how old the entire gal- axy actually ... restricted the range of one species of hydrocoral called Millepora and caused the appar- ent extinction of another species of the same genu...

Ngày tải lên: 12/05/2014, 14:48

... gam- ma-chain gene were causing the im- munodeficiency. With the further assis- tance of Howard M. Rosenblatt of the Baylor College of Medicine and Alexan- dra H. Filipovich of the University of Minnesota, ... Furthermore, if the hot end of the rod is then plunged into ice, a wave of cooling will follow the wave of heat down the length of the metal. In the...

Ngày tải lên: 12/05/2014, 14:49

... dif- ferent risk factors may affect the expres- sion of the disorder,” the group con- cludes in the Journal of the American Medical Association. The lead author of the study, the larg- est of ... professor of psychology at the University of Liverpool, and other academics have ruffled a few well-groomed feathers in the staid linguis- tics community. Their gos-...

Ngày tải lên: 12/05/2014, 15:16

... trade. The decline was reinforced by the social unrest of the late 1960s, which divided the supporters of civil rights. Furthermore, the economic crisis of the 1970s strengthened the hand of the more ... materials pro- vide some of the first insight into the lives of prehistoric women, children and the eld- erly —or, as Soffer describes them, the silent majo...

Ngày tải lên: 12/05/2014, 16:06

... together can determine the thick- ness of the ice and the nature of the underlying rock. With Robin E. Bell of the Lamont-Doherty Geological Obser- vatory, the co-leader of ALICE, Blanken- ship ... unsound. Thus, the largest block of problem states is not in the Òrust beltÓ of the North, nor in the high-traÛc re- gions of the Northeast and Southwest, but ra...

Ngày tải lên: 12/05/2014, 14:49

... SciDex™, SCI- ENTIFIC AMERICAN, 415 Madison Ave- nue, New York, N.Y. 1001 7-1 111 , or fax (212) 35 5-0 408. Photocopying rights are hereby grant- ed by Scientific American, Inc., to li- braries and others ... preexist in the fertilized egg. In- stead the code resides in four sets of mini -genes located in widely separated parts of the nucleus. Antibody diversi- ty springs...

Ngày tải lên: 12/05/2014, 14:50

... colleagues at the Califor- nia Institute of Technology began to ex- amine the chemistry of the atmosphere above Los Angeles. Their work and the research of others have revealed the complexity of atmospheric ... that in almost one Þfth of all the vehicles on the road, the emissions-control equip- ment was either removed by the own- er or damaged by the use of le...

Ngày tải lên: 12/05/2014, 14:50

... Þnding the genes will help scientists uncover the biochemistry of manic-depression. ÒThere are a lot of theories about neurotransmitters, but at the end of the day, when they Þnd the genes, theyÕre ... on the X chro- mosome. The paper has been submit- ted to a journal. Elliot S. Gershon of the National In- stitute of Mental Health is now recruit- ing 100 pairs of...

Ngày tải lên: 12/05/2014, 15:02