Chains of magnetite crystals in the meteorite ALH84001: Evidence of biological origin

The presence of magnetite crystal chains, considered missing evidence for the biological origin of magnetite in ALH84001 [Thomas-Keprta, K. L., Bazylinski, D. A., Kirschvink, J. L., Clemett, S. J., McKay, D. S., Wentworth, S. J., Vali, H., Gibson, E. K., Jr., & Romanek, C. S. (2000) Geochim. Cosmochim. Acta 64, 4049–4081], is demonstrated by high-power stereo backscattered scanning electron microscopy. Five characteristics of such chains (uniform crystal size and shape within chains, gaps between crystals, orientation of elongated crystals along the chain axis, flexibility of chains, and a halo that is a possible remnant of a membrane around chains), observed or inferred to be present in magnetotactic bacteria but incompatible with a nonbiological origin, are shown to be present. Although it is unlikely that magnetotactic bacteria were ever alive in ALH84001, decomposed remains of such organisms could have been deposited in cracks in the rock while it was still on the surface on Mars.

Frieze -- Biological Sciences

Frieze located in front of building. Smith, Hinchman & Grylls, architects. W.B. Wood Co., construction

Precipitation and inactivation of phosphorus as a lake restoration technique /

Mode of access: Internet.

Analysis of specialized pesticide problems : invertebrate control agents-efficacy test methods /

"EPA-540/10-77-001--EPA-540/10-77-007."

Minnesota wildlife disease investigation : a compilation of monthly reports to the Division of Game and Fish, Minnesota Department of Conservation /

"Conducted by University of Minnesota, Bureau of Biological Survey, Minnesota Department of Conservation."

Annual summary of biological investigations at Carlyle Lake.

"Annual report submitted to the U.S. Army Corps of Engineers, St. Louis District, St. Louis, Missouri."

Annual summary of biological investigations at Rend Lake.

"Annual report submitted to the U.S. Army Corps of Engineers, St. Louis District, St. Louis, Missouri."

Graduate education in biological sciences /

"Report to the Board of Higher Education for its use in developing 'Master Plan--Phase III.'"

The crime-- : a glimpse at the workings of the Illinois State Police : Division of Forensic Services.

"01/99"--Colophon.

The crime : a glimpse at the workings of the Illinois State Police : Division of Forensic Services.

"7/07"--Colophon.

The crime : a glimpse at the workings of the Illinois State Police, Division of Forensic Services /

"5/10"--Colophon.

Bulletin of the Buffalo Society of Natural Sciences.

GeoRef

Orientation of biological cells using plane-polarized gaussian beam optical tweezers

Optical tweezers are widely used for the manipulation of cells and their internal structures. However, the degree of manipulation possible is limited by poor control over the orientation of the trapped cells. We show that it is possible to controllably align or rotate disc-shaped cells-chloroplasts of Spinacia oleracea-in a plane-polarized Gaussian beam trap, using optical torques resulting predominantly from circular polarization induced in the transmitted beam by the non-spherical shape of the cells.