Psychiatrists use a diagnosis criteria for major depression that arbitrarily overlook the continuum of symptoms of varying severity and duration.

References:

Kendler, K.S., C.O. Gardner. 1998. Boundaries of major depression: An evaluation of DSM-IV criteria. American Journal of Psychiatry 155(February):172.

Tucker, G.J. 1998. Putting DSM-IV in perspective. American Journal of Psychiatry 155(February):159.

Further Readings: 

Bower, B. 1995. Family docs show depression prowess. Science News 147(March 11):148.

Eleven years after astronomers witnessed supernova 1987A, a shock wave from that cataclysm has begun ramming into a surrounding ring of gas.

References:  

Kirshner, R.P., R. McCray, and G. Sonneborn. 1998. NASA press briefing. Washington, D.C.

Further Readings: 

Cowen, R. 1997. A supernova turns 10. Science News 152(Feb. 22):120.

References:  

Michiels, N.K., and L.J. Newman. 1998. Sex and violence in hermaphrodites. Nature 391(Feb. 12):647.

Further Readings: 

Eberhard, W.G. 1996. Female control: Sexual selection by cryptic female choice. Princeton, N.J.: Princeton University Press.

______. 1985. Sexual selection and animal genitalia. Cambridge, Mass.: Harvard University Press.

References: 

Kawamori, T. . . . B.S. Reddy. 1998. Chemopreventive activity of celecoxib, a specific cyclooxygenase-2 inhibitor, against colon carcinogenesis. Cancer Research (Feb. 1):409.

Further Readings: 

Bhattacharya, I. 1996. Outcome predictor for colorectal cancer reported. Lancet 384(Dec. 21):1725.

Majerus, P.W. 1998. Prostaglandins: Critical roles in pregnancy and colon cancer. Current Biology 8(Jan. 29):R87.

Sternberg, S. 1996. Colorectal cancer: To screen or not? Science News 150(Dec. 7):358.

Symmons, D.P.M. 1996. Safety profile of low-dose aspirin. Lancet 348(Nov. 23):1394.

Watson, A.J.M., and R.N. DuBois. 1997. Lipid metabolism and APC: Implications for colorectal cancer prevention. Lancet 349(Feb. 15):444.

Studies of two proteins suggest how the deadly Ebola virus avoids the immune system and infects cells.

References: 

Yang, Z. . . . G.J. Nabel. 1998. Distinct cellular interactions of secreted and transmembrane Ebola virus glycoproteins. Science 279(Feb. 13):1034.

Further Readings: 

Seppa, N. 1998. Ebola virus vaccine protects guinea pigs. Science News 153(Jan. 10:)22.

A tiny tube made from a stack of ring-shaped peptides allows small ions to pass from one side of a membrane to the other.

References:  

Clark, T.D., L.K. Buehler, and M.R. Ghadiri. 1998. Self-assembling cyclic b ³-peptide nanotubes as artificial transmembrane ion channels. Journal of the American Chemical Society 120(Feb. 4):651.

Further Readings: 

Motesharei, K., and M.R. Ghadiri. 1997. Diffusion-limited size-selective ion sensing based on SAM-supported peptide nanotubes. Journal of the American Chemical Society 119(Nov. 19):11306.

New fossils show that deep-rooted land plants appeared at least 10 million years earlier than previously thought.

References:

Elick, J.M., S.G. Driese, and C.I. Mora. 1998. Very large plant and root traces from the Early to Middle Devonian: Implications for early terrestrial ecosystems and atmospheric p(CO₂). Geology 26 (February):143.

Further Readings: 

Berner, R.A. 1997. The rise of plants and their effect on weathering and atmospheric CO₂. Science 276(April 25):544.

Monastersky, R. 1994. Rooting around for missing carbon. Science News 146(Sept. 17):180.

______. 1993. Plants and soils may worsen global warming. Science News 143(Feb. 13):100.

______. 1993. The leaf annals. Science News 144(Aug. 28):140.

______. 1990. Fossils push back origin of land animals. Science News 138(Nov. 10):292.

______. 1989. Supersoil. Science News 136(Dec. 9):376.

Retallack, G.J. 1997. Early forest soils and their role in Devonian global change. Science 276(April 25):583.

Global warming may boost the intensity of the strongest hurricanes.

References:  

Henderson-Sellers, A., et al. 1998. Tropical cyclones and global climate change: A post-IPCC assessment. Bulletin of the American Meteorological Society 79(January):19.

Knutson, T.R., R.E. Tuleya, and Y. Kurihara. 1998. Simulated increase of hurricane intensities in a CO₂-warmed climate. Science 279(Feb. 13):1018.

African wild dogs burn more energy than predicted during a day, an insight that has forced scientists to rethink the energetics of chasing down dinner and worry about the dogs' loss of food to hyenas.

References: 

Gorman, M.L., et al. 1998. High hunting costs make African wild dogs vulnerable to kleptoparasitism by hyaenas. Nature 391(Jan. 29):479.

The part of a male canary’s song that really excites females—a rapid-fire two-note trill—may be so difficult to produce that it gives clues about the physical condition of the singer.

References:  

Vallet, E., I. Beme, and M. Kreutzer. 1998. Two-note syllables in canary songs elicit high levels of sexual display. Animal Behaviour 55(February):291.

Further Readings: 

Allan, S.E., and R.A. Suthers. 1994. Lateralization and motor stereotypy of song production in the brown-headed Cowbird. Journal of Neurobiology 25:1154.

Vallet, E., and M. Kreutzer. 1995. Female canaries are sexually responsive to special song phrases. Animal Behaviour 49:1603.

Fruit flues exposed to crack cocaine exhibit behavioral responses similar to those displayed by crack-addled humans.

References:  

McClung, C., and H. Hirsh. 1998. Stereotypic behavioral responses to free-base cocaine and the development of behavioral sensitization in Drosophila. Current Biology 8(Jan. 15):109

Scientists have used a vastly more efficient method of cloning to produce two identical calves.

References:  

1998. UMass researchers announce birth of genetically modified cloned calves. University of Massachusetts at Amherst press release.

Further Readings: 

Travis, J. 1997. A fantastical experiment. Science News 151(April 5):214.

_____. 1997. Dolly, Polly, Gene—send in the clones. Science News 152(Aug. 23):127.

Consuming folate and vitamin B₆ at levels well in excess of the recommended daily allowance may lower the risk of heart disease and stroke.

References:  

Rimm, E.B., et al. 1998. Folate and vitamin B₆ from diet and supplements in relation to risk of coronary heart disease among women. Journal of the American Medical Association 279(Feb. 4):359.

Robinson, K., et al. 1998. Low circulating folate and vitamin B₆ concentrations: Risk factors for stroke, peripheral vascular disease, and coronary artery disease. Journal of the American Heart Association(Feb. 10):1.

Further Readings: 

McCully, K.S. 1998. Homocysteine, folate, vitamin B₆, and cardiovascular disease. Journal of the American Medical Association 279(Feb. 4):392.

Omenn, G.S., S.A.A. Beresford, and A.G. Motulsky. 1997. Preventing coronary heart disease: B vitamins & homocysteine. Journal of the American Heart Association(Oct. 14).

Raloff, J. 1997. New heart risk from too much coffee? Science News 151(Jan. 11):22.

______. 1996. More B vitamin benefits. Science News 149(April 13):230.

______. 1996. Folate supplements needed by allergenic. Science News 149(March 30):198.

Travis, J. 1996. Nitric oxide at war with homocysteine? Science News 149(April 27):269.

Prolonged microwave cooking can inactivate much of the vitamin B₁₂ in foods.

References:  

Watanabe, F., et al. 1998. Effects of microwave heating on the loss of vitamin B₁₂ in foods. Journal of Agricultural and Food Chemistry 46(January):206.

Further Readings: 

Travis, J. 1996. Nitric oxide at war with homocysteine? Science News 149(April 27):269.

In the human brain, one neural system perceives the defining qualities of objects whereas another directs visual control of skilled actions.

References:  

Haffenden, A.M., and M.A. Goodale. 1998. The effect of pictorial illusion on prehension and perception. Journal of Cognitive Neuroscience 10(January):122

 Detailed pictures of DNA polymerase show how these enzymes create new DNA strands.

References:  

Watson, J.D., and F.H.C. Crick. 1953. A structure for deoxyribose nucleic acid. Nature 171(April 25):737.

Doublie, S. . . . T. Ellenberger. 1998. Crystal structure of a bacteriophage T7 DNA replication complex at 2.2 A. Nature 391(Jan. 15):251.

Kiefer, J.R. . . . L. S. Beese. 1998. Visualizing DNA replication in a catalytically active Bacillus DNA polymerase crystal. Nature 391(Jan. 15):304.

Further Readings: 

Kunkel, T.A., and S.H. Wilson. 1998. DNA polymerases on the move. Nature Structural Biology 6(February):95.

Patches of partially molten rock at the bottom of Earth’s mantle may profoundly influence conditions at the planet’s surface.

References:  

Helmberger, D.V., L. Wen, and X. Ding. 1997. Extremes in CMB structure beneath Europe and Africa. Meeting of the American Geophysical Union. San Francisco.

Lay, T. 1997. Structure of the boundary layer at the base of the mantle. Meeting of the American Geophysical Union. San Francisco.

Revenaugh, J., Q. Williams, and E. Garnero. 1997. A correlation between ultra-low basal velocities in the mantle and hot spots. Meeting of the American Geophysical Union. San Francisco.

Vidale, J.E., and M.A. Hedlin. 1997. Intense scattering at the core-mantle boundary north of Tonga: Evidence for partial melt. Meeting of the American Geophysical Union. San Francisco.

Williams, Q., and E.J. Garnero. 1996. Seismic evidence for partial melt at the base of Earth’s mantle. Science 273(Sept. 13):1528.

Further Readings: 

Monastersky, R. 1997. Global graveyard. Science News 152(July 19):46.