Why doesn't Cu/ZnSOD affect lifespan in mice?
Posted 10:10 AM

Superoxide dismutase is a critical factor in reducing damage to cells. So why isn't more better?

Looking at the pathways, it's possible that overexpression of SOD in mice merely creates a bottleneck at the pathways for conversion of hydrogen peroxide. In other words, in accordance with Kascer's enzyme activity predictions, without overexpression of GSHPx (and others perhaps) no lifespan increase need be observed. This was proposed by Kurata, et al in 1993 (1)

This argument is sound, but there's more to it.

There are multiple pathways of aging. Just as a single enzyme's activity cannot predict the flux of a pathway, so too a single aging vector (mitochondrial damage) might not impact the overall lifespan of a complex organism. If the mitochondrial damage doesn't kill you the advanced glycation end-products will.

I would image that the more complex the organism, the more pathways of aging there are. Thus the more "multipath" an intervention would have to be in order to have an effect.


(1) HUANG et al. (2000) "Ubiquitous overexpression of CuZn superoxide dismutase does not extendlife span in mice"
(2) Kurata, Masatoshi Suzuki, et al (1993) "Antioxidant systems and erythrocyte life-span in mammals"

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I completely love this site
Posted 12:16 AM

I mean...

1. A HOWTO for DNA extraction.

2. A step-by-step guide for building a gele electrophoresis chamber

3. Animated tours of DNA basics

How can you resist? I'm going through the whole thing with Noakai (he's 5). We both like it a lot.
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Please Support Net Neutrality!
Posted 8:23 AM

Opponents of net neutrality say it will suppress "innovation". Since its inception, the internet has been neutral. Now, all of the sudden, companies are trying to give preferential access to their partners, friends and associates.

There is nothing "innovative" about big companies doing favors for other big companies in order to push out competition from small or new businesses.

I run a web site, I don't have political connections. On my website, I sell products that compete with the likes of WalMart and QVC. WalMart and QVC have negotiated with Comcast and Verizon so that my website is slower than theirs... even though I pay much more for bandwidth per gig of transfer - than they do. They are able to do this because of their political and social connections, and because there's no law to stop them.

This is "innovation"? No, it's abuse of power. And I'm surprised at how many people are on the clearly wrong (meaning morally) side of this debate.

Can a phone company in Chicago who owns a brokerage firm prevent or harrass you when you call a competing firm? No... it's illegal. And that's partly why the U.S. phone system works so well. The Internet should work that way too.
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Will Work for Praise
Posted 2:31 AM

I'm involved in several open source projects and free services that people seem to use. The SMX web development language, a couple CPAN modules, some tools at google code, a captcha generator, etc.

Most of them I built because I needed them, and open sources because of shameless self-promotion. I've noticed that, after releasing code, I completely ignore it unless either a) someone (usually me) needs new feature/fix or b) someone emails me and says they like it.

Praise is, apparently, the bigger motivator. After someone emails me to ask for a patch/fix... I fix it, sure. But after I get praise... I find myself, usually within a few weeks, adding things like testing suites, transaction support, plugins.... or some other major overhaul. Not sure *why* I do that. But after 10 years, I've noticed a pattern.

Labels: politics, programming

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