The researchers' computer model, published this week in the early online edition of the journal Proceedings of the National Academy of Sciences, reproduces nearly all known shell shapes, ranging from scallops to whelks, and nearly all the shell patterns that make beachcombing so popular."The model gives us a remarkable ability to explain much of the dramatic diversity of both shape and pattern that we see in the natural world," Boettiger said. Jump to the link for great animations.
*No representation is made that the person listed here is currently on the state's offenders registry.
He and George Oster, a UC Berkeley biophysicist, along with University of Pittsburgh mathematical neuroscientist Bard Ermentrout, have written a computer program that generates the complex patterns of seashells using simple principles developed to explain how the brain works and how memories are stored.
The "neural net" model explains how mollusks build their seashells based on the finding that the mollusk's tongue-like mantle, which overlaps the edge of the growing shell, senses or "tastes" the calcium carbonate layer laid down the day before in order to generate a new layer."The pattern on a seashell is the mollusk's memories," said Oster, a professor of environmental science, policy and management and of molecular and cell biology.
By adjusting nine parameters in a single equation, a computer model can generate patterned shells (right example in each pair above) that closely resemble real mollusk shells.
(Jump to original article in the link below for great animations.)University of California, Berkeley, graduate student Alistair Boettiger has amassed a beautiful collection of seashells, but not by combing the beach. A simple neural network model of seashell growth can generate realistic mollusk shells based on a simple principle discovered 140 years ago.
Nebraska parents who marry or move in with registered sex offenders could have a harder time maintaining custody under a bill heard by a legislative committee Thursday that opponents say unfairly stigmatizes offenders. Brett Lindstrom, of Omaha, introduced the measure in response to a 2016 Nebraska Supreme Court decision that prevented a father from gaining custody of his teenage daughters.
The divorced father sued for custody after learning from a public registry that his daughters' new stepfather was a registered sex offender.
Stockham-area historical tornado activity is slightly above Nebraska state average. The bill also would require everyone with custody or access rights to be notified that a sex offender is living with or has unsupervised access to the child.The father in the case spoke in favor of Lindstrom's bill."What it comes down to is a matter of common sense," he said.All names presented here were gathered at a past date.Some persons listed might no longer be registered offenders and others might have been added.