Orac is pessmistic and depressed about the future of science and science-based medicine. I share his concern, but am significantly more optimistic. This is exactly the reason why I want to become an MD/PhD; to apply research directly to medicine. I even wrote about it on my application essay.
I didn’t write it explicitly, but Orac and some other science bloggers played a big role in this decision. So, Orac, don’t slip into dispair, you’re doing great work and reaching a lot of people in important ways.
As part of the the new Colbert report’s greenscreen challenge, the goal is to make presidential nominee seem more interesting. These are my two favorites:
A while ago I posted a bit about my research woes. Well, I’m happy to report that my efforts since then have been fruitful. Creating the new constructs seem to have done the trick. There must have been something wrong with the original recombinant plasmid I was using (one that I didn’t actually create myself, by the way).
I’d never thought I would be so happy about seeing a little purple band appear on a little peice of paper before, but that band indicates the right protein is getting expressed and I can see it via western blot.
DaveScot, an IDiologist who writes for the uncommondescent blog has claimed to have found a mistake in Richard Lenski’s paper. (which I first talked about here)
He points to a statement made by Lenski: (DaveScot’s emphasis)
However, selection requires heritable variation
generated by random mutation, and even beneficial mutations
may be lost by random drift.
And then points to a study done by the Scripps institute that would seem to contradict this statement:
The bold portion is patently wrong. Selection operates on any heritable variation whether random or not… The Scripps researchers, in a nutshell, discovered that E. coli, when stressed (such as running out of food as in Lenski’s experiment or in the presence of antibiotics in the Scripps experiment) selectively increases the mutation rate on certain genes.
What DaveScot has wrong (and I believe he was refering to this experiment) is that the study says that mutations are purposefully induced on specific genes. However, the doesn’t say that only beneficial mutations are induced or that mutations were localized only to specific genes. This is a case of an organism increasing the rate of random mutations, which is a good survival strategy for a population to increase its genetic diversity. However, it does not appear to be the case, that the bacteria is select for their own survival.
So DaveScot is wrong in saying:
Thus the mutations in this case are not random but rather directed at a certain area in an attempt to solve a certain problem.
There is no basis to this teleological statement. Bacteria aren’t attempting to solve a problem, not in the same humans do when we create a new medicine or drug. They are simply increasing their genetic diversity (and probably not on purpose either, more likely in response to selection pressures), so that when antibiotics are around, the probability of a random mutation conferring antibiotic resistance is increased.
Richard Lenski, whose groundbreaking work witnessed the evolution of citrate-using E. coli in a mere 44,000 generations over 20 years of work.
He responds directly to conservapedia’s ignorant creationism populace published by conservapedia (amazingly enough) here:
Lenski’s second letter is particularly good, filled with lots of good biochemistry, scientific philosophy and general good sense. A highly recommended read.
This story is quite bizarre. Random human feet, encased in sneakers, are washing up on the shore of Vancuver and small islands off the coast. Nobody has a clue as to where they’re coming from, why they keep turning up in the same general location or why most of them seem to be the right foot.
I haven’t been blogging much recently, prefering to spend my time studying for the MCATs or working on some of the research projects I’m currently involved with. Hopefully soon I’ll be off to some hospital to shadow a doctor. But, I just had to share this story.
Sciencedaily reports on chimp behavior, saying that chimps keep quiet during copulation, in order to evade detection of other chimps. I suspect that this is a mechanism chimps use to obscure paternity, which is interesting considering that chimps also make it quite obvious when they’re in estrus.
At any rate, it doesn’t seem to be a trait we share with chimps, at least judging from some of the shadier motels I’ve had the misfortune of staying at.
This continues the series I started the other day, answering questions about the physics of bicycles. Well, now I have some questions of my own. Questions that need answers. Answers that are worth millions of Shrute bucks.
I made some observations while on my daily bike ride today that I couldn’t explain the physics of. It was related to this statement I wrote in my previous post:
Another interesting affect about turning while on a bicycle is called “counter-steering.” If you were to travel along a straight path and simply turn the wheel to the right, you’d simply fall over. This is because the center of mass must be under the bicycle in order to remain upright. Turning the wheel moves the center of mass out from under the bike. In order to successfully turn, you must first steer the bike slightly in the opposite direction of the turn in order to shift the center of mass to the correct position so you can later lean for the turn. It’s the same principle as balancing any object on your hand. You have to move the bottom of the object to the direction that the top of the object is falling, in order to reposition the center of mass. While this slight turn in the opposite direction is necessary for all speeds, it’s more noticeable at high speeds, which is why decreasing velocity for a tighter turn in a good idea. But, if you decrease the speed too much, momentum will be lost (to friction) and the bike and rider will fall over.
Given that this is true (and I believe that it is) I wanted to test some other aspects of leaning versus steering control. I found that leaning is necessary to alter your course by small angles, when traveling on a relatively straight path. However, for 90 degree turns, simply leaning is not going to get the job done.
I tried to simply turn the front wheel via the handlebars in the direction I wanted to make such a 90 degree turn, while traveling a straight path. I noticed that I soon as a turned the handlebars even slightly I felt the bike start to tip. Almost immediately following that, however, the back part of my bike seem to “catch up” with the front wheel, causing me to continue on a straight path.
My question is if this is some physical property (perhaps my momentum?) which makes the bike want to continue on a straight path, or is it some unconscious steering on my part? I assume it has to do with the repositioning of the center of mass, so that the bike doesn’t tip, but is this because I don’t want it to tip, or because the bike can’t physically tip when traveling forward at a significant velocity?
What I find interesting, as well, is that it is impossible to turn without first steering in the opposite direction of the turn and then leaning to make the turn. This seems to be the only possible way to reposition your center of mass in order to make a successful turn. Is this also true?
The scientists behind Dolly, the world’s first cloned sheep, have been announced as the winners of the Shaw Prize, the million-dollar award known as the Nobel Prize of the east.
Work worthy of a prize, to be sure. But, I find the name of the Shaw Prize a little confusing. Aren’t ’scientists of the East’ already eligible for the Nobel prize? Or is it just that its awarded from the east?
It’s been a while since I’ve blogged about my own work. I thought I’ve give an update.
I have the chaperone of the CS1 pathway cloned onto a vector and in a host strain. But for some reason, I haven’t been able to induce expression to high enough levels to be useful for an overlay assay, in the periplasm prep.
In english, Gram-negative Enterotoxigenic E. coli (ETEC) have two membranes. I strip the outher membrane off and collect the proteins in the periplasm space. But, for some reason, the protein I’m trying to collect, which chaperones other CS1 pilus proteins between the two membranes, is not to be found in the periplasm.
Therefore, I’m going to take the gene out of the plasmid vector its currently in and try putting it into a different one. Wish me luck.
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