You mentioned lipid rafts, and to drive the point home, I would cite a type of lipid called inositol phosphates. These lipids have 5 positions available for modification by phosphorylation. And there are 7 possible lipids that are commonly found in the cell (http://dx.doi.org/10.1016/j.tibs.2008.07.002). Separating these things apart is a nightmare...
There are also many nonstandard nucleic acid bases. If you take any cellular transfer RNA (tRNA), there are modifications to the different bases. Common examples are pseudouridine, dihydrouridine, inosine, methylated A and G, and there are many, many more. Lysine tRNA has a modified base in the anticodon stem (the part that the ribosome uses to match to the messenger RNA to code for proteins) that alters its specificity to make it better decode the correct message. There are dozens of examples like these which go to show how evolved the decoding process is.
I think there is a difference in the definition of "replicate" that you are using. Prions are "misfolded" proteins. For prions to propagate, there need to be ribosomes, protein synthesis, etc. So, in one sense, the prions are not self-replicating because they rely on cellular machinery (as most viruses do). On the other hand, a prion protein can refold a precursor protein and in this sense can self-replicate. The resulting prion aggregates are what can be damaging to the cell. If you have access to PNAS, here's a recent commentary on what goes into determining the structure of prions (http://www.pnas.org/content/early/2008/09/03/0806234105.full.pdf+html).
Some proteins also aggregate, and these aggregates can lead to disease (tau or amyloid-beta proteins in Alzheimer's, for example). The aggregated structure is often different from the soluble structure, so in this sense these proteins also undergo a refolding event. Interestingly, some dyes can stop this aggregation from occurring, and I suspect there are similar molecules that will hinder the aggregation of prions. Then again, the commentary linked above argues why prions are different from protein aggregates.
Access Brutal honesty, we don't really care about the access restrictions. Every university has license to pretty much all the major journals. We can get them from wherever with a quick login and so can everyone we know. Sorry, but that's the truth.
This is simply not true. I work at a very large university, and it still amazes me to find that some electronic journals have not been purchased by the university. When I need these articles pronto, I must email friends at other universities. But what about smaller colleges? Enthusiasts? (I doubt there are that many biochemistry enthusiasts, but I'm sure there are a few who would love reading the new Methods in Enzymology or Nature, Science, Cell, what have you. The field needs these enthusiasts.)
I would also add to this that some journals (Journal of Biological Chemistry comes to mind) have 10000+ pages per year. It's quite expensive to purchase the printed version of this journal, as it is expensive to publish it. No one that I know goes to the library anymore for journal articles as most are online. And at our university the ones that are not online are available via a copying service.
I think that if the moral problems are resolved, it would be very beneficial to go ahead with obtaining knockout embryos. This has been accomplished for yeast and is underway for other higher eukaryotes. Having knockout embryos/fetuses/cells for all human genes could have great potential in curing any number of diseases. It would also facilitate a much deeper understanding of the human body in the sense that the effect of knocking out genes on early development would be better understood.
Of course, the moral problems are incredibly difficult, and that aside, the knockouts would take a long, long time to procure. But in my opinion, this proof of principle is a step in the right direction.
Slashdot Mirror
So the choice is still (ahem) up in the air?
So they'll get 20 million dollars for passing or failing the class?
yes but you forgot to mention: YAY I'm level 8, wow I got my wish for a silver dragon scale mail ... You've been killed by a newt.
...
repeat, and that's where the depression comes in
You mentioned lipid rafts, and to drive the point home, I would cite a type of lipid called inositol phosphates. These lipids have 5 positions available for modification by phosphorylation. And there are 7 possible lipids that are commonly found in the cell (http://dx.doi.org/10.1016/j.tibs.2008.07.002). Separating these things apart is a nightmare ...
There are also many nonstandard nucleic acid bases. If you take any cellular transfer RNA (tRNA), there are modifications to the different bases. Common examples are pseudouridine, dihydrouridine, inosine, methylated A and G, and there are many, many more. Lysine tRNA has a modified base in the anticodon stem (the part that the ribosome uses to match to the messenger RNA to code for proteins) that alters its specificity to make it better decode the correct message. There are dozens of examples like these which go to show how evolved the decoding process is.
I didn't see selenocysteine ... that makes 69
I think there is a difference in the definition of "replicate" that you are using. Prions are "misfolded" proteins. For prions to propagate, there need to be ribosomes, protein synthesis, etc. So, in one sense, the prions are not self-replicating because they rely on cellular machinery (as most viruses do). On the other hand, a prion protein can refold a precursor protein and in this sense can self-replicate. The resulting prion aggregates are what can be damaging to the cell. If you have access to PNAS, here's a recent commentary on what goes into determining the structure of prions (http://www.pnas.org/content/early/2008/09/03/0806234105.full.pdf+html).
Some proteins also aggregate, and these aggregates can lead to disease (tau or amyloid-beta proteins in Alzheimer's, for example). The aggregated structure is often different from the soluble structure, so in this sense these proteins also undergo a refolding event. Interestingly, some dyes can stop this aggregation from occurring, and I suspect there are similar molecules that will hinder the aggregation of prions. Then again, the commentary linked above argues why prions are different from protein aggregates.
Lawyers would definitely say the campaign has been a success.
the competition was organized by OPEC?
if he were really that good, he would have done all of this during his job interview
Access Brutal honesty, we don't really care about the access restrictions. Every university has license to pretty much all the major journals. We can get them from wherever with a quick login and so can everyone we know. Sorry, but that's the truth.
This is simply not true. I work at a very large university, and it still amazes me to find that some electronic journals have not been purchased by the university. When I need these articles pronto, I must email friends at other universities. But what about smaller colleges? Enthusiasts? (I doubt there are that many biochemistry enthusiasts, but I'm sure there are a few who would love reading the new Methods in Enzymology or Nature, Science, Cell, what have you. The field needs these enthusiasts.)
After all, they would buy out the rights to Godel, Escher, Bach ...
I would also add to this that some journals (Journal of Biological Chemistry comes to mind) have 10000+ pages per year. It's quite expensive to purchase the printed version of this journal, as it is expensive to publish it. No one that I know goes to the library anymore for journal articles as most are online. And at our university the ones that are not online are available via a copying service.
didn't you see stargate sg-1? we're not in the reality that has met the asgaard yet either ...
And that's on 640x480
So 28139?
I don't have a desk, you insensitive clod!
The Russkies probably already have a firewall doomsday device.
I strongly suggest that we either abandon our botnet plans or we get ourselves one of these doomsday devices.
Ingredient 1: Botnet
... kick back and watch the rise of our impending doom ...
Ingredient 2: Robot that reassembles when kicked apart
Ingredient 3: U.S. military's armed robots
I think that if the moral problems are resolved, it would be very beneficial to go ahead with obtaining knockout embryos. This has been accomplished for yeast and is underway for other higher eukaryotes. Having knockout embryos/fetuses/cells for all human genes could have great potential in curing any number of diseases. It would also facilitate a much deeper understanding of the human body in the sense that the effect of knocking out genes on early development would be better understood.
Of course, the moral problems are incredibly difficult, and that aside, the knockouts would take a long, long time to procure. But in my opinion, this proof of principle is a step in the right direction.
Also, a cabinet is only as good as its leader, making the cutoff of 20 far lower for the U.S. right now ... I would suggest a number like 4, or 1 ...
I think it's worthy to note that Vista costs as much as the low-cost PCs.
(I base this on the near 300 dollars for Vista Ultimate and near 200 dollars for Home Basic.)
What about bin and hex?
Hey, I live in Ohio, and I guarantee you that the crops grown around here look like mud and grass to me ...
Oh not quite. China will then eat the U.S., thus approaching singularity