Clipmarks | abailart's clips

Crossed (evolutionary) signals?

Tue, 01 Jul 2008 23:43:05 GMT

clipped by: Silkweaver
clipper's remarks: Animals depend on tyrosine phosphorylation to conduct a number of important communications between their cells, including immune system responses, hormone system stimulation and other crucial functions. These phospho-tyrosine signaling pathways utilize a three-part system of molecular components to make these communications possible.

Clip Source: www.physorg.com

What do humans and single-celled choanoflagellates have in common? More than you'd think.

New research into the choanoflagellate genome shows these ancient organisms have similar levels of proteins that cells in more complex organisms, including humans, use to communicate with each other.

According to a paper published last week in the Proceedings of the National Academies of Sciences, these findings help confirm choanoflagellates' role as an evolutionary link between single-celled and multi-celled organisms.

They also contend that these insights into the organism's genome may mean that the proteins used to help cells communicate may have other roles as well.

By analyzing the recently-sequenced choanoflagellate genome, the researchers discovered another similarity between choanoflagellates and most metazoans--their genetic code caries the markers of three types of molecules that cells use to achieve phospho-tyrosine signaling proteins.

Tags: evolution, dna, cell signalling

Wonderful Kurt Vonnegut Interview

Tue, 01 Jul 2008 17:25:58 GMT

clipped by: papananook
clipper's remarks: Well worth the whole read...I loved Vonnegut.

Clip Source: cathy-edgett.livejournal.com

As war against Iraq looms, I asked Vonnegut, a reader and supporter of this magazine, to weigh in. Vonnegut is an American socialist in the tradition of Eugene Victor Debs, a fellow Hoosier whom he likes to quote: “As long as there is a lower class, I am in it. As long as there is a criminal element, I am of it. As long as there is a soul in prison, I am not free.”

—Joel Bleifuss

You have lived through World War II, Korea, Vietnam, the Reagan wars, Desert Storm, the Balkan wars and now this coming war in Iraq. What has changed, and what has remained the same?

even somebody as old as I am, which is 80, only just got here. There were already all these games going on when I got here. … An apt motto for any polity anywhere, to put on its state seal or currency or whatever, might be this quotation from the late baseball manager Casey Stengel, who was addressing a team of losing professional athletes: “Can’t anybody here play this game?”

Shift Happens

Tue, 01 Jul 2008 13:54:45 GMT

clipped by: Sheroug
clipper's remarks: Check the source for the slideshow or click to download

Clip Source: www.slideshare.net

This is a stylization of a slideshow originally created by Karl Fi more

Download file

10 Important Differences Between Brains and Computers

Tue, 01 Jul 2008 10:34:22 GMT

clipped by: wildcat

Clip Source: scienceblogs.com

Although the brain-computer metaphor has served cognitive psychology well, research in cognitive neuroscience has revealed many important differences between brains and computers. Appreciating these differences may be crucial to understanding the mechanisms of neural information processing, and ultimately for the creation of artificial intelligence. Below, I review the most important of these differences (and the consequences to cognitive psychology of failing to recognize them): similar ground is covered in this excellent (though lengthy) lecture.

Difference # 1: Brains are analogue; computers are digital

Difference # 2: The brain uses content-addressable memory

Difference # 3: The brain is a massively parallel machine; computers are modular and serial

Difference # 4: Processing speed is not fixed in the brain; there is no system clock

Difference # 5 - Short-term memory is not like RAM

Difference # 6: No hardware/software distinction can be made with respect to the brain or mind

Tags: computers, brains, metaphors