March 29, 1997

First Peek at DNA Transcription

Atomic force microscope images show an enzyme molecule straddling a strand of DNA and pulling it along to complete the transcription phase of manufacturing proteins in cells.

References:

Kasas, S., et al. 1997. Escherichia coli RNA polymerase activity observed using atomic force microscopy. Biochemistry 36(Jan. 21):461.

Thomson, N.H. 1997. Observing protein motion with atomic force microscopy. 1997 March meeting of the American Physical Society. Kansas City, Mo.

Eye pigments may depend on one amino acid

Changing one amino acid in light-sensitive pigments alters their molecular properties.

References:

Imai, H., et al. 1997. Single amino acid residue as a functional determinant of rod and cone visual pigments. Proceedings of the National Academy of Sciences 94(March 18):2322.

Further Readings:

Lipkin, R. 1995. Additional genes may affect color vision. Science News 147(Feb. 18):100.

_____. 1994. The eye's photochemistry: A quick snap. Science News 146(Oct. 29):279.

_____. 1994. A keen view of vision: Seeing cone cells. Science News 146(Oct. 8):231.

Peterson, I. 1991. Ultrafast first step for light into sight. Science News 140(Oct. 26):261.

Conscience grows on temperamental ground

Children take different paths in developing an internal guide to right and wrong behavior, depending on how well early temperament meshes with a mother's child-rearing practices.

References:

Kochanska, G. 1997. Multiple pathways to conscience for children with different temperaments. Developmental Psychology 33(March):228.

Newman, D., A. Caspi, et al. 1997. Antecedents of adult interpersonal functioning. Developmental Psychology 33(March):206.

Further Readings:

Grusec, J., and L. Kuczynski, eds. 1997. Handbook of Parenting and the Transmission of Values. New York: Wiley.

Swapping insulin syringes for tiny beads

Coating substances with plastics that cling to tissue and slowly erode holds promise as a way to deliver medicines.

References:

Mathiowitz, E., et al. 1997. Biologically erodable microspheres as potential oral drug delivery systems. Nature 386(March 27):410.

Raloff, J. 1997. New glucose test on the way for diabetes. Science News 152(March 29):190.

Further Readings:

1996. A shot in the arm for protein delivery. Science News 150(July 27):63.

Travis, J. 1996. Swallowing shigella: Can bacteria that cause food poisoning deliver oral DNA vaccines? Science News 149(May 11):302.

Meteorite still holds inklings of life

Researchers discuss the latest findings about the possibility that traces of ancient, primitive life remain in a Martian meteorite.

References:

Kirschvink, J.L., et al. 1997. Annual Lunar and Planetary Science Conference. Houston.

Leshin, L.A., et al. 1997. Annual Lunar and Planetary Science Conference. Houston.

Steele, A., et al. 1997. Annual Lunar and Planetary Science Conference. Houston.

Thomas-Keprta, K.L., et al. 1997. Annual Lunar and Planetary Science Conference. Houston.

Valley, J.W., et al. 1997. Annual Lunar and Planetary Science Conference. Houston.

Further Readings:

Cowen, R. 1997. More findings about life on the Red Planet. Science News 151(Feb. 8):87.

______. 1996. Searching for life in a Martian meteorite. Science News 150(Dec. 14):380.

______. 1996. Meteorite hints at early life on Mars. Science News 150(Aug. 10):84.

Cowen, R., and R. Monastersky. 1996. Pursuing life on two frontiers. Science News 150(Nov.9):292.

New glucose test on the way for diabetes

A novel polymer offers the possibility of lowering the cost and increasing the reliability of blood-sugar monitoring.

References:

Chen, G. . . .F.H. Arnold. 1997. A glucose-sensing polymer. Nature Biotechnology 14(April):354.

Wilson, G.W. 1997. Making an imprint on blood-glucose monitoring. Nature Biotechnology 14(April):322.

Further Readings:

Centofanti, M. 1995. Diabetes complications: More than sugar? Science News 148(Dec. 23&30):421.

Fackelmann, K. 1993. Regimen slows diabetic complications. Science News 143(June 19):388.

Raloff, J. 1993. Fats may influence insulin sensitivity. Science News 143(Jan. 30)68.

______. 1993. Diabetes: Clarifying the role of obesity. Science News 143(Jan. 2):7.

Smaglik, P. 1997. Swapping insulin syringes for tiny beads. Science News 151(March 29):189.

Newfound gene linked to several cancers

Investigators have found a single gene whose inactivation may contribute to a variety of cancers, including a rare malignancy that affects the brain and a common form of breast cancer.

References:

Li, J. . . .R. Parsons. 1997. PTEN, a putative protein tyrosine phosphatase gene mutated in human brain, breast and prostate cancer. Science 275(March 28):1943.

Steck, P.A., et al. 1997. Identification of a candidate tumor suppressor gene, MMAC1, at chromosome 10q23.3 that is mutated in multiple advanced cancers. Nature Genetics 15:356.

Florida manatees' future: Grim or golden?

A population viability analysis of Florida's manatees paints a precarious future for the animals.

References:

Maromontel, M., S.R. Humphrey, and T.J. O'Shea. 1997. Population viability analysis of the Florida manatee (Trichechus manatus latirostris), 1976-1991. Conservation Biology 11(April):1.

Further Readings:

O'Shea, T.J., B.B. Ackerman, and H.F. Percival, eds. 1995. Population Biology of the Florida Manatee. U.S. Department of the Interior National Biological Service Information and Technology Report 1. Washington, D.C.

Research Note:

Biomedicine

Study casts doubt on breast self-exam

Malignant tumors are detected at the same rate in a self-exam group as in a control group.

References:

Thomas, D.B., et al. 1997. Randomized trial of breast self-examination in Shanghai: Methodology and preliminary results. Journal of the National Cancer Institute 89(March 5):355.

A complicating view of breast implants

One-quarter of all women with breast implants develop serious complications.

References:

Gabriel, S., et al. Complications leading to surgery after breast implantation. New England Journal of Medicine 336(March 6):677.

Earth Science

When glaciers covered the entire Earth

Twice in the planet's distant past, ice ages have engulfed the globe.

References:

Evans, D.A. 1997. Low-latitude glaciation in the Palaeoproterozoic era. Nature 386(March 20):262.

Further Readings:

Monastersky, R. 1997. Could gas blast have warmed globe? Science News 151(March 22):181.

______. 1996. The mother lode of natural gas. Science News 150(Nov. 9):298.

Searching for life in fire and ice

Scientists are gearing up to hunt for microbes hiding out in unusual places.

References:

Juniper, S.K., and M. Purdy. 1997. Press Conference at the American Geophysical Union.

Further Readings:

Monastersky, R. 1997. Deep dwellers. Science News 151(March 29):192.

Physics

Particle tracking and liquid flow

Tracking the erratic path of a microsphere immersed in a tiny volume of fluid allows researchers to determine the liquid's flow properties.

References:

Mason, T.G., et al. Preprint. Particle tracking microrheology of complex fluids.

Mason, T.G., S. Kuo, and D. Wirtz. 1997. Optical microrheology of concentrated linear DNA. Bulletin of the American Physical Society 42(March):35.

Cooking up carbon doughnuts

The ends of a cylindrical carbon nanotube can join to form a doughnut-shaped ring.

References:

Liu, J., et al. 1997. Fullerene "crop circles." Nature 385(Feb. 27):780.

Probing atomic migration in thin wires

Researchers can use X-ray microbeams to track atomic rearrangements in narrow wires and measure stress buildup during electromigration.

References:

Cargill, G.S. 1997. X-ray microprobe study of electromigration. Bulletin of the American Physical Society 42(March):5.

Further Readings:

Peterson, I. 1997. X-ray microprobe unveils biostructures. Science News 151(March 22):172.

Articles:

Deep Dwellers

Microbes thrive far below ground

Once considered sterile, Earth's deep crust turns out to be rife with life.

References:

Krumholz, L.R., et al. 1997. Confined subsurface microbial communities in Cretaceous rock. Nature 386(March 6):64.

Pedersen, K. 1996. Microbial life in granite rock. 1996 International Symposium on Subsurface Microbiology. Davos, Switzerland.

Tseng, H.Y., T.C. Onstott, and M. Person. 1996. A Mesozoic age for the deep subsurface bacteria within the Triassic Taylorsville Basin, Virginia. American Geophysical Union meeting. San Francisco.

Further Readings:

Adler, T. 1995. Living free of photosynthesis. Science News 148(Oct. 21):263.

Gold, T. 1992. The deep, hot biosphere. Proceedings of the National Academy of Sciences 89(July):6045.

Stevens, T.O., and J.P. McKinley. 1995. Lithoautotrophic microbial ecosystems in deep basalt aquifers. Science 270(Oct. 20):450.

Information on Onstott's work is available at http://geo.princeton.edu/geomicrobio.

Forbidden Flavors

Scientists consider how disgusting tastes can linger surreptitiously in memory

The tendency of a wide variety of animals to avoid food or drink associated with nausea has spawned research into the biology of taste aversion, predator control, social communication about dangerous food, and anorexia nervosa.

References:

Bermudez-Rattoni, F., et al. 1995. The role of the insular cortex in the acquisition and long-lasting memory for aversively motivated behavior. In Plasticity in the Central Nervous System, J. McGaugh, et al., eds. Mahwah, N.J.: Lawrence Erlbaum Associates.

Garcia, J. 1990. Learning without memory. Journal of Cognitive Neuroscience 2(July):287.

Garcia, J., F. Ervin, and R. Koelling. 1966. Learning with prolonged delay of reinforcement. Psychonomic Science 5:121.

Garcia, J., D.F. Quick, and B. White. 1984. Conditioned disgust and fear from mollusk to monkey. In Primary Neural Substrates of Learning and Behavioral Change, D. Alkon and J. Farley, eds. New York: Cambridge University Press.

Gustavson, C., et al. 1988. Estrogen induced malaise. In Control of Reproductive Function, J. Lakoski, et al., eds. New York: Alan Liss, Inc.

______. 1974. Coyote predation control by aversive conditioning. Science 184:581.