Tiny specks of carbon discovered in 3.85-billion-year-old rocks indicate that life on Earth arose far earlier than previously thought and in a period of asteroid bombardment.

Hayes, J.M. 1996. The earliest memories of life on Earth. Nature 384(Nov. 7).

Mojzsis, S.J., et al. 1996. Evidence for life on Earth before 3,800 million years ago. Nature 384(Nov. 7):55.

Pendick, D. 1993. Fossils show early diversity of life. Science News 143(May 1):276.

On Mars:

A British team announced that the abundance of organic compounds in a young Martian meteorite, as well as their isotopic ratio of carbon-13 to carbon-12, suggests bacteria may have thrived on Mars as recently as 600,000 years ago.

Grady, M.M., C.T. Pillinger, and I.P. Wright. 1996. Meeting on the possibility of life in the solar system. Royal Society, London.

Amato, I. 1989. Meteorite may carry organic Martian cargo. Science News (July 22):53.

Cowen, R. 1996. Interplanetary Odyssey. Science News 150(Sept. 28):204.

_____. 1996. Meteorite Hints at Early Life on Mars. Science News 150(Aug. 10):84.

McDonald, G.D., and J.L. Bada. 1995. A search for endogenous amino acids in the Martian meteorite EETA79001. Geochimica et Cosmochimica Acta 59(6):1179.

Wright, I.P., M.M. Grady, and C.T. Pillinger. 1989. Organic materials in a Martian meteorite. Nature 340(July 20):220.

Boning up on postmenopausal hormones

Lens gets X rays to a point

An aluminum lens focuses high-energy X rays to a spot only a few micrometers wide.

Snigirev, A., et al. 1996. A compound refractive lens for focusing high-energy X-rays. Nature 384(Nov. 7):49.

1991. Glass tubes for concentrating X-rays. Science News 139(April 13):236.

Peterson, I. 1992. New glass 'lens' for intensifying X-rays. Science News 141(June 27):422.

Deadly Ebola virus seen to thrive in bats

By inoculating jungle-dwelling animals and plants with lethal Ebola virus, researchers have shown that healthy bats may harbor the virus, whose source in nature remains a mystery.

Swanepoel, R., et al., 1996. Experimental inoculation of plants and animals with Ebola virus. Emerging Infectious Diseases (an online journal of the Centers for Disease Control and Prevention) 2(October-December):4.

Depression fails to scar personality

A long-term study finds that people who suffer an initial episode of major depression do not experience lasting personality changes, such as becoming more introverted or dependent on others.

Shea, M., et al. 1996. Does major depression result in lasting personality change? American Journal of Psychiatry 153(November):1404.

Kendler, K., et al. 1993. A longitudinal twin study of personality and major depression in women. Archives of General Psychiatry 50(November):853.

Gene variations sway prostate cancer risk

An enzyme that converts testosterone to a more potent hormone comes in two versions; which one a man has may partially determine his risk of prostate cancer.

Reichardt, J., et al. 1996. Genetic variation of SRD5A2 gene encoding sterorid 5-alpha reductase type II and prostate cancer risk (poster 1067). Annual meeting of the American Society of Human Genetics. San Francisco, CA.

Reichardt, J., et al. 1995. Genetic variability of the human SRD5A2 gene: Implications for prostate cancer risk. Cancer Research 55(Sept. 15):3973

Ant life: It's a sister-eat-brother world.

To increase the chances of passing their genes on to future generations, some female ants seem to kill off male siblings.

Sundström, L., M. Chapuisat, and L. Keller. 1996. Conditional manipulation of sex ratios by ant workers: A test of kin selection theory. Science. 274(Nov. 8):993.

Seger, J. 1996. Exoskeletons out of the closet. Science. 274(Nov. 8):941.

Research Notes:

Astronomy:

Hailing Hale-Bopp

After a fallow period this spring, in which it looked like Comet Hale-Bopp might prove a fizzle, the icy body has become more active, so it still may be the most dramatic comet of the century when it nears Earth next March.

Weaver, H.A. 1996. Annual meeting of the American Astronomical Society's Division of Planetary Sciences. Tucson

Cowen, R. 1995. Keeping track of a bright comet ... . Science News 148(Dec. 23 & 30):428.

_____. 1995. ...And estimating its size. Science News 148(Dec. 23 & 30):428.

_____. 1995. Hubble finds surprises in the solar system. Science News 148(Oct. 14):244.

_____. 1995. Picturing Hale-Bopp in the infrared. Science News 148(Sept. 23):200.

_____. 1995. New comet might be quite a sight. Science News 148(Aug. 12):103.

Biology:

Does parenting or prolactin hit first?

The hormone prolactin appears to direct some birds to take on parenting responsibilities for their relatives' offspring.

Schoech, S., R. Mumme, and J. Wingfield. 1996. Prolactin and helping behaviour in the cooperatively breeding Florida scrub-jay, Aphelocoma c. coerulescens. Animal Behaviour 52(September):445.

Birds keep close track of seed business

Chickadees replace missing seeds from their winter food caches on almost a one-for-one basis.

Lucas, J. R. 1996. Annual meeting of the Animal Behavior Society. Flagstaff, Ariz.

Lucas, J.R. 1994. Regulation of cache stores and body mass in Carolina Chickadees (Parus carolinensis). Behavioral Ecology. 5:171.

Lucas, J.R., L.J. Peterson, and R. Boudinier. 1993. The effects of time constraints and changes in body mass and satiation on the simultaneous expression of caching and diet-choice decisions. Animal Behaviour 45:639.

Lucas, J.R., and L. R. Walter. 1991. When should chickadees hoard food? Theory and experimental results. Animal Behaviour 41:579.

Behavior:

Out-of-order memories

The act of trying not to think about an episode, such as a traumatic experience, makes it difficult to remember the sequence in which events occurred and may lead to a repression-like memory loss.

Wegner, D., F. Quilian, and C. Houston. 1996. Memories out of order. Journal of Personality and Social Psychology 71(October):680.

Wegner, D. 1994. Ironic processes of mental control. Psychological Review 101(January):34.

Anatomy of apprehension

The amygdala, an almond-shaped brain structure, appears to specialize in picking up signs of threat and danger in the social world, according to a new brain-scan investigation.

Morris, J. . . .R. Dolan. 1996. A differential neural response in the human amygdala to fearful and happy facial expressions. Nature 383(Oct. 31):812.

Biochemistry:

Molasses recruit bacteria for cleanup

Mixing molasses with TNT-contaminated soil spurs bacteria to break down the explosive into harmless molecules.

Pelkie, D.J. Researchers find sweet solution to TNT-contaminated soil. Press release from Argonne National Laboratory, Argonne Ill. Oct. 7, 1996.

Pseudomonas and Prince William Sound. 1990. Science News 137(April 14):236.

Magnetic bacteria probe for proteins

Scientists have hitched antibodies to tiny magnetic particles made by bacteria in order to pull proteins out of a solution.

Matsunaga, T., et al. 1996. Chemiluminescence enzyme immunoassay using bacterial magnetic particles. Analytical Chemistry 68(Oct. 15):3551.

Sakaguchi, T., Burgess, J.G., and T. Matsunaga. 1993. Magnetite formation by a sulphate-reducing bacterium. Nature 365(Sept. 2):47.

Sternberg, S. 1996. Mother's Blood Shows Baby's Future. Science News 150(Nov. 2):276.

Articles:

The Mother Lode of Natural Gas

Methane hydrates stir tales of hope and hazard

Vast deposits of frozen methane beneath the seafloor could be the fuel of the future.

Holbrook, W. S., et al. 1996. Methane hydrate and free gas on the Blake Ridge from Vertical Seismic Profiling. Science 273(Sept. 27):1840.

Kvenvolden, K. A. 1993. Gas hydrates--Geological Perspective and global change. Reviews of Geophysics 31(May):173.

Gastrointestinal Blues

Research finds bugs that inflame the human gut

Microbes may cause gastrointestinal inflammation in people who are genetically susceptible.

Mishina, D., Greenstein, R., et al. 1996. On the etiology of Crohn disease. Proceedings of the National Academy of Sciences 93(September 3):9816.

Rath, H., Sartor, B., et al. 1996. Normal luminal bacteria, especially bacteroides species, mediate chronic colitis, gastritis, and arthritis in HLA-B27/human (2 microglobulin transgenic rats. The Journal of Clinical Investigation 98 (August):1.