Check out this summary of results on aging in nematodes. The layman’s summary is this:
Aging is thought to be due to accumulated damage. As we age our bodies get lots of microscopic injuries and accumulated cellular damage. Over time it adds up and our bodies break down and we die. This is the prevailing hypothsis because it’s easy to see the mechanism for how it came to evolve.
An alternate hypothesis is that our genes dictate that we age and die, and it’s programmed into us. So rather than breaking down, aging is the result of changes in metabolic regulation.
This study finds evidence supporting the latter model, which is pretty interesting. To summarize their experiment they used gene-chips to exhaustively search for genes that change their expression level in old worms, and linked many of them to a single regulatory protein (transcription factor). Then they tried to put stresses on young worms to see if they could increase the level of this transcription factor, effectively making the worm age faster. They were not able to, which indicates that the transcription factor levels are not a function of stress. Of course, this is only true if they were using the “right” stresses on the worms.
In any case, I’m always excited to see work done that supports any sort of programmed-senescence model, because it points toward the possibility of regulating aging by only tweaking a few things.
Ok, this is a departure from my normal biotech / research stuff, but there’s so much internet-stupidity going on that I want to post something about basic financial math.
Everyone has their panties in a bunch because the iPhone 3G costs less up front but “costs more over the life of the contract!” This is a bunch of crap, and people who believe that are also going to get screwed when they buy a car or a house.
Here’s the thing: you cannot compare 2 financial deals simply by adding up all of the payments and seeing which is bigger, because there is such a thing as the “time value of money.”
Continue reading ‘iPhone 3G costs are unchanged over first gen’
I wanted to share this great youtube video demonstrating a classic kitchen-science non-newtonian fluid: cornstarch and water. The creator puts this mixture on a cookie plate and presses the plate against a subwoofer. The result is pretty great!
A little background on newtonian fluids
In a newtonian fluid the shear rate (rate of flow) is directly proportional to the shear force (how hard you push on the liquid), and the constant of proportionality is the viscosity. So if you double the shear force, you double the shear rate. In a non-newtonian fluid that’s not true, and it can be untrue in different ways. The most straightforward comment is that you can get a non newtonian fluid if the viscosity is not constant. In the case of cornstarch and water you have a fluid where the harder you shear it the more viscous it gets. Compare this to water where the harder you shear it the faster it flows.
Wikipedia has a decent article on non newtonian fluids that you could check out.
A group of oceanographic scientists are in the process of publishing results indicating that the ocean has stripes. They used successive levels of data filtering to remove large scale variations like currents and waves and temperature gradients, and they were left with these bands of very small variation in temperature and velocity.
An interesting observation here is that they repeated their approach on the output from a Japanese computer running the “Earth Simulator” and found very similar stripes in the output from that model.
Maybe I’m just overly skeptical, but it seems to me that if you run a bunch of data filtering and end up with a bunch of surprisingly fine-scale features you have to wonder if it’s an artifact of the analysis. And the fact that they found the same features in the model output, when presumably the model wasn’t programmed to have this behavior, seems to indicate that the stripes are coming from the data filtering and are not real phenomena. Otherwise that seems to say that the Earth Simulator model is so accurate that it was predicting previously unimagined phenomena in the ocean, which would be pretty remarkable in itself.
For the record: I’m not an expert in oceanography, I’ve just got some experience modeling physical systems. They may be right, and there may be tons of stripes overlaid on the ocean. I’m sure their first thought was that it was an artifact, and it must have checked out after reviewing the analysis. It just seems a little fishy.
I came across this in summary for at Ars.
Andy Grove, the famous CEO of Intel, has spoken out publicly against the pharmaceutical industry. I’d like to comment on a few of his statements.
First a few words on my perspective. Before moving to biotech I actually had a stint in process development at Intel, so I’m pretty familiar with the industry and the technology. Now I’m in R&D in the biotech industry which, while not really the same as pharma in general, still gives me a good perspective on the challenges of drug development.
Mr. Grove is a very smart guy who’s been very successful in his industry. He’s not just a management-focused CEO, but an actual technical expert who’s made it to the top. My point here is just that he’s got a credible reputation for technical matters.
I picked the semiconductor industry because it’s the one I know; I spent 40 years in it, during which it became the foundation for all of electronics. It has done a bunch of unbelievable things, powering computers of increasing power and speed. But in the treatment of Parkinson’s, we have gone from levodopa to levodopa. ALS [Lou Gehrig's disease] has no good treatment; Alzheimer’s has none.
This is, unfortunately, a nonsensical comparison. Grove’s main point is that the semiconductor industry has made huge strides in 40 years but the pharma industry has not.
Continue reading ‘Andy Grove is mistaken about the drug industry’
Ars technica wrote an article using explanations of homeopathy as an example of how you can tell pseudoscience from real science. It’s not the most clearly written argument, but it covers the points.
A quick explanation of homeopathy: you put some “stuff” in water, then you dilute it. The real kicker is that in homeopathy you dilute the original solution so much that there are zero molecules of the original “stuff” in it. In fact, it’s claimed that the more you dilute it the more powerful it gets. When you drink the water it will have medicinal powers as a result of the water having “memory” of the stuff that was in it. And there really are zero molecules of stuff in the water. Let’s be clear: homeopathy has beneficial effect only through the placebo effect. There’s no evidence at all that there is such a thing as “water memory” or an inverse dose response (more diluted water works better).
Continue reading ‘Homeopathy as a case study of bad science’
You may have seen the stories going around the net today about a scientist who’s discovered how to burn salt water, and that the DOE is going to investigate this as an alternative source of energy. Let me explain why this is stupid.
Dr. Roy said the salt water isn’t burning per se, despite appearances. The radio frequency actually weakens bonds holding together the constituents of salt water — sodium chloride, hydrogen and oxygen — and releases the hydrogen, which, once ignited, burns continuously when exposed to the RF energy field. Mr. Kanzius said an independent source measured the flame’s temperature, which exceeds 3,000 degrees Fahrenheit, reflecting an enormous energy output.
Let me break this down for you, serious science style:
Continue reading ‘Burning salt water will not fuel your car’
I’m writing this for friends and family who may not be aware of the value of using RSS to keep up with news and periodically updated sites. If you learned about this post via your feed reader then you can skip this article…
Continue reading ‘Why you should use RSS & Google Reader’
I’ve been involved in a few discussions recently about stem cell research, and I think there’s a lot of misunderstanding, in addition to outright deception, going on in the public debates.
By way of introduction, I’m a Ph.D. researcher at a biotech drug company and I’ve been involved in research in academia as well. While I am involved in bacterial / mammalian cell fermentation, and not stem cells, I have a good understanding of this issue, and the technologies involved. It’s another example of attempts to politicize science, and politicize facts. The science says embryonic stem cells are the way to go. Period. End of story. If you think there’s a morally unjustifiable cost associate with those benefits then just say that. That’s an intellectually honest debate to have, and one that could be had in the public sphere.
Continue reading ‘Stem Cell Research’
Clinical trials are the statistical testing of new drug molecules in human patients to determine safety and effectiveness. You frequently hear about drugs having “promising results after Phase II clinical trials” and you may not know exactly what that means.
First, to be clear, a great deal of development effort goes into a candidate molecule before it ever enters a person. There will have been extensive lab tests, tests in animal models (an animal, such as a rat, which has a condition that mimics the human disease of interest) as well as toxicity tests in animals. In general, perhaps 1 in 1000 molecules makes it all the way to phase 1 trials. In biotech, the ratio is probably higher, but that should give you an idea. And once you enter into clinical trials, the majority (perhaps the great majority) of candidate drugs fail at each phase.
A quick summary is:
- Phase I – is it safe?
- Phase II – does it work?
- Phase III – fully, statistically define the drug
Continue reading ‘What are clinical trials?’