See here.

Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials

Gordon C S Smith, professor1, Jill P Pell, consultant2
1 Department of Obstetrics and Gynaecology, Cambridge University, Cambridge CB2 2QQ, 2 Department of Public Health, Greater Glasgow NHS Board, Glasgow G3 8YU

Abstract

Objectives To determine whether parachutes are effective in preventing major trauma related to gravitational challenge.

Design Systematic review of randomised controlled trials.

Data sources: Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists.

Study selection: Studies showing the effects of using a parachute during free fall.

Main outcome measure Death or major trauma, defined as an injury severity score > 15.

Results We were unable to identify any randomised controlled trials of parachute intervention.

Conclusions As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute.

Hat tip to Overcoming Bias

Just got them back from the 1-hour photo place this afternoon. Took the rest of the afternoon off work, scanned them, and then uploaded them to the Internet website Flickr.

One of the good things about not being able to blog about my work is that I can upload random charts and not have to exert the keyboard bashing required to explain my thoughts.[1]

X axis would be current account balance.[2]
Y axis is loan to deposit ratios for random banks

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[1] Which are largely derived from another happily married Aussie bloke.
[2] Dada thanks to another Aussie bloke.

Just so folks know, I'm heading on honeymoon for almost two weeks starting Friday. My posting frequency will be undisturbed by this event.

Should be fun.

despite getting married outside in pouring rain, a good time was had by all.

I spent Saturday afternoon at a birthday picnic for one of S.'s good friends who works in the film biz. The great thing about that crowd is that I get to both live vicariously through their stories and also I am reminded of the brief period when I worked in film post production. No offense to my current coworkers, but there is something special about working with creative creative people, rather than technically or financially creative people.

In a conversation with a guy who does indy film distribution, after fawning over his current project with Werner Herzog, we got into a discussion about the future of the industry with all the youtube and whatnot. I made some throw-away line about how branding isn't yet well established online and there may be some possibilities there. But what really got me thinking was the lack brand identities in the re-democratization of arts and entertainment.

Directors, record labels, musicians and producers succeed when they become brands. As much as I wish it weren't so, I would have never sat through all of Gerry if I didn't know it was a Gus Van Sant film. Countless songs would have missed out on the critical 5th replay required for them to catch on if I didn't know that they were written by X or released by Y. Sure, it is not a hard and fast rule and I discover new and unknown stuff all the time. But we all go the extra mile in accepting familiar brands. I am loyal.

If it weren't for the coin slot, people would have no qualms in stealing their morning newspaper, or so would be the case if we were all Homo Economicus. Plenty-o-folk download music without worrying about paying their dues to the artists. But would we do so if the band was watching us at the time? Radiohead's great experiment in behavioral economics showed us that when given the option of free, many people still elected to pay. I posit that it was merely the act of making the consumer aware of the option at the time of download that resulted in this. Not a really stunning observation, but I think it is key.

And it wouldn't work for bands who weren't brands. If you don't know what you are getting, you probably won't pay. However, if you were aware of the artists situation, you might come back and pay. Online, this might be as simple as putting up a download link with a big message along side: "The band remains poor and starving. Please help." But being a technologist, I think we can do better.

Imagine a system whereby independent artists collected payments, voluntary or not, through a central clearinghouse. That way each artist could accurately display how much income they are making from their music, and various stats about downloads. Starving artists can use their prandially challenged status to help convince listeners to share a few dollars. And popular artists will get all the benefits of popularity.

This could easily be another feature of last.fm or similar. But they are busy building a walled garden of listener behavior data. However there is no reason why this needs to be a centralized service. Distribute this sucker. That way record labels can do whatever it is that online record labels do, and can collect the cash. They can then distribute the cash to the artists, which I hear they do, on rare occasion, do.

Production costs are decreasing. Anyone with talent & a computer can make a great film or album. Companies yearn for strong brands as consumers can then align their personal images with these brand identities. Art and entertainment is a visceral identifier of personal characteristics. I like the music that I like because it says something about me. I strongly believe that given repeated exposure anyone can at least enjoy, if not love, any form of art. At some stage I chose the music, film and art that I wanted to be identified with, and later did the deep connection and enjoyment grow. As individuals the clothes we buy, the food we eat and the entertainment that we enjoy often provides a shortcut to our own deeper identity.

So, why do entertainer incomes follow a power distribution? Why does Coldplay have the benefit of being able to turn down multi-million dollar advertising deals when countless other musicians have to rely on government subsidies to feed themselves? These poorer artists are not always lesser in their art. I can understand that in a world where search costs are high, attention is focussed on a smaller set of well marketed artists. However with the diminished cost of search, consumers should be more selective in their choice of art brands. And if the audience is free to sample unrestricted digital works, but are aware of the status, needs and micro-brand of the artists, I would like to think that we can arrive at a more even distribution of wealth across the arts.

And then I'd find a way of sticking a fiver in this guy's cap.

After some email goading from Jerry[1] I have decided to share a few of my thoughts on the problems with twitter. First off, let me say that I don't know the people behind twitter and I have no access to the sort of information I'd want to see before I could even come close to forming a cogent opinion. So everything from here on is most definitely wrong and bone-headed.

In my reply to Jerry I made some claims based on my initial rumination about Twitter's problems. I decided to do some further digging and found that Jeff Atwood's[1] opinion is pretty close to mine. Namely, that the first order of business is to stop blaming Ruby or Rails (neither of which I have used), and instead thinking about the underlying platform. For me, this means thinking long and hard about their database.

Whatever I'm actually paid to do in my career, I always seem to end up working with sizeable datasets. And I think databases are totally swell. Bees knees. I'm one transaction shy of putting a poster of Codd on my wall. But sometimes, not due to lack of effort, I give up on databases and end up rolling my own data crunching application. Databases are so swimmingly handsome because they let you approach them and make general queries on data. Sure, there is an art and science to optimizing a database for specific queries, but 90% of the time you don't have to think about that.

c.f. The Twitter API specification[1]

When Twitter was just an Obvious twinkle in someone's eye, a database made perfect sense. Who knew what Twitter would become and the flexibility of a database is a huge advantage. But now Twitter is Twitter: A messaging service. And save the discovery of a business model, the announced coming features don't dramatically impact architectural requirements for the service. Oh, and since the original implementation of the prototype service, Twitter has experienced massive growth and downtime is crushing goodwill. I say, ditch the general purpose database, implement a custom solution. The great thing about a custom database is that it really doesn't take much time to build if you know your usage patterns. Whereas a RDBMS has to make guesstimates as to how to execute a query, and optimize that execution against a set of generic index types, a custom solution can use custom index algorithms. For example, as part of a recent bit of hacking I got a few thousand fold speed improvement from moving an app from a well managed commercial database to some hand rolled C. For a key join, the RDBMS was performing its best, but we were able to perform better by making a merge-bsearch-linear scan algorithm that made perfect sense for this application.

In short, if you are database bound, and your database is well managed, and your application has known query patterns - ditch the database. People seem to forget the computational bandwidth at their fingertips. Grab the nearest napkin, scrible down a rough estimate of the bandwidth requirements of your app and then compare that to your computer. If A << B and you are suffering performance issues, then you are in a happy place - it should be easy and rewarding to solve.

Step away from your computer and just think about what it means to have 2 GILLION CYCLES PER SECOND. Thems be a lot. Use them.

My napkin calculations based on over-heard numbers suggest that a platform change would suffice and make Twitter as happy as Larry. But let's say that someone goes along and implements what I'm talking about and that's still not enough. Well, then it gets to be _real_ fun. I took a wee bit of graph theory at school, but I also have the pleasure of having friends who took an unhealthy amount of graph theory. It is a well studied domain. If platform level optimization isn't enough there is a wealth of knowledge in this space on optimially placing resources to maximize bandwidth. Twitter is probably pretty close to a fully connected graph. But where are the cut points? How lumpable is the distance matrix? How does the matrix evolve over time? (Pretty slowly, I guess) What is the optimal time period for relocating clusters of users across your horizontally scaled system? And why am I not hearing any discussion online about these questions? (Probably because I haven't looked.)

OK. It is 4:30AM and I should be packing for the move tomorrow. So I'll cut it short. Edgar[2] and Edsger[3]. People have been thiking about these types of problems for a long time. I know how daunting it can be when you are running a system and everything goes to shit. Immediate reaction is to patch stuff. Sometimes that just makes it worse. Read the literature, mine your operational data and find a better way.

And whatever you do, don't listen to some wacky Australian on the blog-o-sphere.

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[1]: I'll come back tomorrow and add links to this blog after I become a Brooklynite.
[2]: Codd
[3]: Dijkstra