Ha...I recognize the panel on the tape drive here:

http://www.google.com/about/datacenters/gallery/#/all/18

I wasn't around then, but I've been reading up on him and all the rest of the Apollo astronauts since. I'm filled with wonder every time I think about it.

Thank you for everything, sir. I hope your eternity is a pleasant one.

Well put. Fare well, Mr. Armstrong.

(Whoops, just saw that you said it was part of textual criticism...)

Thanks for the term "stemmatics" -- I was familiar w/the concept but knew it as "textual criticism", which I think is probably a great deal more broad than this. What's always bugged me about this concept -- perhaps unfairly -- is whether or not it has any experimental evidence to back it up. My impression is that it's a bunch of heuristics based on a preference for simplicity. Is there any experimental evidence to suggest that texts do grow/change the way these rules say? (I'm not asking for you to chip in (although you're welcome to - hey, your journal :-), more just outlining my next bout of reading in my spare time.)

Sorry to jump in, but I happened to read a neat paper in Nature about something like this a while back. It was called Rise and fall of political complexity in island South-East Asia and the Pacific. TThe article is behind a paywall, but there's a general summary from Wired magazine here, and another aimed at fellow researchers here.

My half-assed summary: the researchers use phylogenetic methods -- ways of looking at genomes from organisms and estimating how long ago they had common ancestors (I'm sure Samantha could give a better/actually accurate explanation) -- and see if it can be applied to societies to see how they change over time. In this study, they looked at a bunch of different groups in the south Pacific and tested different models about how political organization could change (would people go from loose tribes to highly-organized kingdoms in one step? what about the other way around?). It was interesting stuff.

Many thanks for the explanations!

The researchers I work with deal with microarray data a lot, and have built a tool to help compare datasets (http://www.chibi.ubc.ca/Gemma). I'm becoming more familiar with the technology as I go along, but the heat maps and the dendrogram legends (is that what they're called?)...man, those are some dense infodumps.

Heyo -- thanks for the heads-up on Twitter. I'm the sysadmin at a small university department, and I work with scientsts studying gene expression. They're good and patient people, but sometimes I feel a bit like I'm questioning the foundations of their work...which feels either rude or ignorant.

First off, I'd always been under the impression that DNA was only/mainly used during reproduction -- a cell divides under DNA direction, some bit of the cell is the machinery that makes whatever protein is needed during its life, and DNA isn't involved much after that. However, I'm starting to understand (I think...) that I've got it all wrong. My understanding now that gene expression can basically turn on a dime, and that *this* is the usual way a cell makes a protein: something happens to a cell, it says "Whoah, I need protein X", and it starts transcribing the DNA so it can manufacture it (modulo things like gene regulation). This process can take very little time (hours or less). Have I got that right?

Second: one of the things they study is datasets of gene expression in post-mortem brains. (Well, technically I guess I've got that wrong, since genes aren't expressed post-mortem... :-) As I understand it, someone dies -- say, someone with schizophrenia -- their brains are donated to science, and at some point someone does microarray sequencing of blendered neurons. This is compared to brains of control subjects, gene X is found to be over/under-expressed in schizophrenic brains, and so gene X is involved somehow in schizophrenia. (This is a gross simplification, especially in the case of schizophrenia; my understanding is that these signatures cover many, many genes, they're subtle at best, and there's nothing like "a gene for schizophrenia".)

What I don't understand:

a) Since time passes between death and sequencing, how much fidelity does/can this have do what was going on at the point of death?

b) Even if it is a good indication of what was going on at death, how does that relate to a long-term illness like schizophrenia when (assuming I've got this bit right) gene expression can turn on and off in a very short time? I realize there are (ahem) ethical problems with doing brain biopsies on living subjects, and that post-mortem is the best that can be done -- but how good can it be?

Many, many thanks for your time. Any questions about system administration, let me know. :-)

1. What's their methodology? How exactly did they get this info? I see nothing here like a link to a full paper.
2. Who are they and why should I trust them? Disclaimer: I could turn out to be woefully ignorant, and maybe I should just get my head out of my ass. But their main web page appears to be amazingly content-free, and there are two posts on the blog -- this is one of them. (To be fair, the
3. They only present two data points here -- Jan 18 and Jan 19. What's happened since? Why the breathless summary (Slashdot's and the blog post) saying file sharing is all going to Europe now?
4. The post-Jan 19 diagram says the hosting provider breakdown changed, which is presumably why they're breathless about Europe. But there's no data presented on where those new providers are located -- no corporate info, no datacentre locations, nothing.

If there's something to see here, I'm missing it.

I was going to post something similar but you beat me to it. Many thanks!

I think that what you want is The Ephemerizer, by Radia Perlman (she of OSPF fame). I heard about this a few years ago at the LISA conference, and a bit of digging turned it up. From the abstract:

This paper is about how to keep data for a finite time, and then make it unrecoverable after that. It is difficult to ensure that data is completely destroyed. To be available before expiration it is desirable to create backup copies. Then absolute deletion becomes difficult, because even after explicitly deleting it, copies might remain on backup media, or in swap space, or be forensically recoverable. The obvious solution is to store the data encrypted, and then delete the key after expiration.

Google turns up this copy in PDF.

Hope that helps!

You could try something like:

• Keep a list of passwords (I use Emacs + GPG, but there's bound to be something out there that'll work for you if that's not your style)
• Print out the list monthly (if that really is how often you change passwords)
• Seal it and put it in a safety deposit box at your local bank
• Tell everyone "In case of my death, go here for passwords"

(Alternately, this could be something a lawyer could help with -- something like holding passwords in trust, only to be given up in the event of X, Y, Z...)

Yes, it's a pain in the ass. But it would work, and it would mean your executor/spouse/etc would only have one set of people to convince that you're dead.