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August 2, 1997
Early Flowering Tree Discovered
An ancient plant lineage rediscovered in Madagascar is expected to provide new insights into the evolution of flowering plants.
Further Readings:
Crane, P.A., E.M. Friis, and K.R. Pedersen. 1995. The origin and early diversification of angiosperms. Nature 374(March 2):27.
Two research groups have independently identified a protein used by the intestines to grab needed iron out of food.
References:
Fleming, M., et al. 1997. Microcytic anaemia mice have a mutation in Nramp2, a candidate iron transporter gene. Nature Genetics 16(August):383.
Gunshin, H., et al. 1997. Cloning and characterization of a mammalian proton-coupled metal-ion transporter. Nature 388(July 31):482.
Further Readings:
Fackelmann, K. 1997. Rusty organs. Science News 151(Jan. 18):46.
Vulpe, C., and J. Gitschier. 1997. Ironing out anaemia. Nature Genetics 16(August):319.
Whistling a superfluid quantum melody
Helium-3 atoms can quantum mechanically shuttle back and forth between two reservoirs connected by an array of tiny apertures, demonstrating the superfluid analog of the Josephson effect in superconductors.
References:
Pereverzev, S.V., et al. 1997. Quantum oscillations between two weakly coupled reservoirs of superfluid helium-3. Nature 388(July 31):449.
Further Readings:
McClintock, P. 1997. Whistles from superfluid helium. Nature 388(July 31):421.
Peterson, I. 1997. Superfluid gyro detects Earth's spin. Science News 151(April 12):223.
Additional information about the Josephson effect in superfluid helium-3 is available at http://physics1.berkeley.edu/research/jcdavis/ .
Is synergy of estrogen mimics an illusion?
The withdrawal of a much-touted, year-old scientific article describing extraordinary synergy between estrogenlike pollutants has catalyzed discussion of what constitutes synergy.
References:
McLachlan, J.A. 1997. Synergistic effect of environmental estrogens: Report withdrawn. Science 277(July 25):462.
Further Readings:
Arnold, S.F., and J.A. McLachlan. 1996. Synergistic activation of estrogen receptor with combinations of environmental chemicals. Science 272(June 7):1489.
Bergeron, J.M., D. Crews, and J.A. McLachlan. 1994. PCB's as environmental estrogens: Turtle sex determination as a biomarker of contamination. Environmental Health Perspectives 102(September):780.
Dees, C. 1997. The effects of xenoestrogens are addictive in stimulating human breast cancer cells entry into the cell cycle. NIH meeting on Estrogens in the Environment IV. Arlington, Va.
Raloff, J. 1997. A new world of pollutant effects. Science News 151(March 1):S19.
______. 1996. 'Estrogen' pairings can increase potency. Science News 149(June 8):356.
______. 1995. Beyond estrogens. Science News 148(July 15):44.
______. 1994. Gender-bending PCB's. Science News 145(October 8):239.
______. 1994. That feminine touch. Science News 145(Jan. 22):56.
______. 1994. The gender benders. Science News 145(Jan. 8):24.
______. 1993. EcoCancers. Science News 144(July 3):10.
Rammamoorthy, K., et al. 1997. Potency of combined estrogenic pesticides. Science 275(Jan. 17):405.
Safe, S., et al. 1997. Estrogenic activity of a dieldrin/toxaphene mixture in the mouse uterus, MCF-7 human breast cancer cells and yeast-based estrogen receptor assays: No apparent synergism. NIH meeting on Estrogens in the Environment IV. Arlington, Va.
Wade, M. 1997. Interactions between endosulfan and dieldring on estrogen-mediated processes in vitro and in vivo: Lack of synergy. NIH meeting on Estrogens in the Environment IV. Arlington, Va.
Wiese, T.E., et al. 1997. Lack of synergistic estrogen effects of dieldrin and endosulfan mixtures in mammalian cells. NIH meeting on Estrogens in the Environment IV. Arlington, Va.
Preschoolers get grip on hidden emotions
Children between 3 and 5 years old can distinguish between real and feigned emotions, as well as the social rules guiding emotional expression.
References:
Banerjee, M. 1997. Hidden emotions. Social Cognition 15(Summer):107.
Further Readings:
Bower, B. 1997. Social sense may heed uneven inheritance. Science News 151(June 14):365.
______. 1993. A child's theory of mind. Science News 144(July 17):40.
Odd companions create unusual environment
Oil and water both adhere to a specially treated titanium dioxide surface.
References:
Wang, R., et al. 1997. Light-induced amphiphilic surfaces. Nature 388(July 31):431.
Further Readings:
Lipkin, R. 1995. Coating self-cleans glass and paints. Science News 148(Sept. 2):157.
Fetal cells may trigger autoimmune
disease
Lingering fetal cells may cause a woman's immune cells to attack her tissue.
References:
Bianchi, D. 1997. Jackson Laboratory and Johns Hopkins University's Press Week 1997. Bar Harbor, Maine.
Craters and extinctions: Time of reckoning
A buried crater discovered last year in South Africa may explain extinctions at the end of the Jurassic period.
References:
Bottomley, R., et al. 1997. The age of the Popigai impact event and its relation to events at the Eocene/Oligocene bundary. Nature 388(July 24):365.
Koeberl, C., R.A. Armstrong, and W.U. Reimold. 1997. Morokweng, South Africa: A large impact structure of Jurassic Cretaceous boundary age. Geology 25(August):731.
Further Readings:
Monastersky, R. 1997. The call of catastrophes. Science News 151(March 1):S20.
Research Notes:
Behavior
Factual brains, uneventful lives
Three people who suffered brain damage early in life yield evidence that different cerebral regions take responsibility for event memory and fact memory.
References:
Vargha-Khadem, F., et al. 1997. Differential effects of early hippocampal pathology on episodic and semantic memory. Science 277(July 18):376.
Further Readings:
Squire, L., and B. Knowlton. 1994. Memory, hippocampus, and brain systems. In The Cognitive Neurosciences, M. Gazzaniga, ed. Cambridge, Mass.: MIT Press.
Heading out of the hippocampus
Rat experiments suggest that, contrary to prior scientific assumptions, brain areas outside the hippocampus can direct some forms of spatial memory.
References:
Golob, E., and J. Taube. 1997. Head direction cells and episodic spatial information in rats without a hippocampus. Proceedings of the National Academy of Sciences 94(July 8):7645.
Earth Science
El Nino gathers steam in Pacific
The equatorial Pacific is warming rapidly in response to a strong El Nino.
References:
The National Oceanic and Atmospheric Administration issued an El Nino/Southern Oscillation climate advisory on July 15. The information is available on the web at http://nic.fb4.noaa.gov:80/products/analysis_monitoring/enso_advisory/index.html .
Further Readings:
Monastersky, R. 1997. Pacific warmth augurs weird weather. Science News 151(May 24):316.
Flying on sunlight
A pilotless solar-powered plane has soared to record-breaking heights.
Articles:
Spying Diseases from the Sky
Satellite data may predict where infectious microbes will strike
Scientists studying Lyme disease, cholera, and other infectious diseases are testing whether remote sensing data can be used to identify regions likely to be afflicted.
References:
Colwell, R.R. 1997. American Society for Microbiology. Miami Beach, Fla.
Further Readings:
Colwell, R.R. 1996. Global climate and infectious disease: The cholera paradigm. Science 274(Dec. 20):2025.
NASA's Center for Health Applications of Aerospace Related Technologies maintains a website at: http://geo.arc.nasa.gov/sge/health/chaart.html .
Computers have conquered tic-tac-toe, checkers, and chess. What's next?
Researchers and software developers have used a variety of strategies to bring computer programs that play games, including chess, checkers, backgammon, bridge, Go, and Scrabble, to the expert level.
References:
Newborn, M. 1997. Kasparov versus Deep Blue: Computer Chess Comes of Age. New York: Springer-Verlag.
Schaeffer, J. 1997. One Jump Ahead: Challenging Human Supremacy in Checkers. New York: Springer-Verlag.
Further Readings:
Levy, D. 1983. Computer Gamesmanship: Elements of Game Design. New York: Simon & Schuster.
Levy, D., and M. Newborn. 1991. How Computers Play Chess. New York: W.H. Freeman.
Marsland, A.T., and J. Schaefer, eds. 1990. Computers, Chess, and Cognition. New York: Springer-Verlag.
The Hall of Champions event at the Fourteenth National Conference on Artificial Intelligence has a home page at http://www.aaai.org/Conferences/National/1997/champions.
Deep Blue's most recent match against Garry Kasparov is detailed at http://www.chess.ibm.com.
L. Victor Allis describes various games that he has solved, including connect-4, Qubic, and Go-Moku, in his book Searching for Solutions in Games and Artificial Intellligence (http://www.cs.vu.nl/~victor/thesis.html).
You can find out more about the checkers program Chinook and play against it at http://www.cs.ualberta.ca/~chinook.
The WWW Backgammon Page is at http://www.gamesdomain.com/backgammon. Details of how Gerald Tesauro's TD-Gammon functions are posted at http://www.research.ibm.com/massdist/tdl.html. The program itself is available free with OS-2 software available from IBM (http://www.austin.ibm.com/pspinfo/fundtdgammon.html). You can obtain information about playing JellyFish, developed by Fredrik Dahl, at http://www.effect.no/what is.html.
Matthew Ginsberg describes his bridge-playing program GIB at http://www.cirl.uoregon.edu/ginsberg/bridge.html.
An extensive introduction to the computer Go field is available at http://www.psyuq.edu.au/~jay/go/CS-TR-339.hmtl. The program HandTalk, available as a commercial product, is described at http://commerce1.ba.best.com/~webwind2/go/soft/ECC19.html. One of the strongest computer Go players is The Many Faces of Go at http://pw1.netcom.com/~fotland/manyfaces.html. The American Go Association has a website at http://www.usgo.org/.
Scrabble information, including a section on computer Scrabble, is available at http://www.teleport.com/~stevena/scrabble/faqtext.html.
A large number of links related to machine learning in games is posted at http://forum.swarthmore.edu/~jay/learn-game/index.html.
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