IMAGES: Neurons on Display
The Cell Centered Database from the University of California, San Diego, is a destination for everyone from anatomists charting the nuances of neuron branching to modelers hoping to devise more realistic cell simulations. Launched in 2002, the archive houses images, reconstructions, and models of nerve cells of brain neurons based on microscopy data, including confocal and electron. The site helps fill the gap between gene and protein databases and those holding images of larger brain structures, says project leader Maryann Martone. Visitors can access images and raw data on more than 30 nervous system cells. Included, for instance, is an image in which the colors indicate the different dendrite segments in a Purkinje neuron from a rat's cerebellum. The listings also include measurements such as the cell's surface area and the lengths of major branches. So far the archive only encompasses nerve cells, but Martone and colleagues will soon add mitochondrial data.
EXHIBITS: Lakota Timekeeping
Today, photos, videos, history books, and newspaper archives help us hold on to the past. The Lakota people of the U.S. Great Plains relied on their memories and on winter counts, illustrated calendars that feature an evocative drawing for each year. Visitors can peruse a collection of winter counts and anthropologists can analyze their iconography at this new exhibit from the Smithsonian Institution. The records served as mnemonics, helping Lakota oral historians keep events in the right order. The symbol the count keeper chose to represent a particular year depicted an occurrence that everyone would recall. The site lets users scroll through 10 counts covering mainly the 18th and 19th centuries, such as the one kept by Battiste Good, a Lakota in South Dakota. Click on the drawings to read a description of what happened during those years. The 1849 symbol in Good's count records an attack on a Crow man disguised as a woman, and the 1850 illustration shows Crow warriors taking refuge on a butte after a reprisal raid.
DATABASE: Foundations of Fertility
A female mouse can ovulate a fresh batch of eggs about every 4 to 6 days. To learn more about the genes that sustain egg production and orchestrate other ovarian functions, click on this collection from researchers at Stanford University. The Ovarian Kaleidoscope Database describes more than 1800 genes that work in the ovaries of humans, mice, rats, and other animals. Entries indicate the gene's function, where it's active in the ovary, what controls its expression, the effects of particular mutations, and more. Links lead to additional information about the gene's structure and its roles in biochemistry and diseases.
LINKS: Stuck on Sugars
Like many unsuccessful dieters, the proteins called lectins are drawn to carbohydrates. The molecules, which range from the poison ricin to infection-squelching compounds in the blood, glom onto sugars and kindred substances. Delve into the world of lectins with this sprawling collection of some 2000 links from Thorkild Bøg-Hansen of the University of Copenhagen in Denmark. A primer on lectins introduces groups such as the collectins, which recognize carbohydrates in bacterial cell walls and rouse the body's defensive proteins. Visitors can also scan a database with 3D lectin structures or read up on the lectin in kidney beans that occasionally causes food poisoning.
COMMUNITY SITE: Herp Haven
How many species of corn snakes are slithering around the United States? Were any new kinds of salamanders discovered last year? Catch up on the latest developments in reptile and amphibian taxonomy at the Center for North American Herpetology, headed by Joseph Collins of the University of Kansas, Lawrence. There you can check the standard scientific and common names for 596 species of reptiles and amphibians—including the two species of corn snakes, one of which scientists recognized only in 2002, and the striking gray-banded king snake (Lampropeltis alterna) of Texas and Mexico. The site announces newly described species and records classification and nomenclature updates for existing ones.