This is the same mechanism of action as the Complement System used by your Immune System. Antibodies recognize and bind to a bacteria and recruit the first part of the system, which inserts itself into the cell membrane. The first part of the system recruits other proteins, which recruit other proteins, etc., until a ring of proteins is made in the cell membrane. Since the concentration of salt, protein, sugar, and everything else is higher inside the cell than outside, water rushes in through the tiny hole and the cell membrane ruptures from the rapid expansion of volume.
Wow, someone on/. that actually knows something from real life experience. I'm to understand that your reclusive group is scheduled to be classified as an endangered species.
Disappointing, ne?
I thought that any damage to cartilage caused it to calcify into bone after a long period of painful tenderness. I'm a wrestler, thereby being very familiar with cauliflower ear. For those who don't know, a painful condition whereby the cartilage of the ear becomes tender and inflamed after being pounded upon by a competitor (also developed from talking on the phone too much). Older wrestlers tend to have knobby, hard ear lobes. How do you put new cartilage in without causing damage and the corresponding calcification?
The condition you are talking about isn't really a transformation into bone material. Also, it's not 'any' trauma that will result in it. You need wide spread crushing damage to the tissue to get the necessary disruption. A small laceration such as from a scalpel shouldn't do enough damage to starve out all the local cells.
Here's a little more information about it. Note the bit about 'treatment'.
Hope this helps.
Okay, I've actually worked in the Vacanti Tissue Engineering laboratory, the lab that did the Ear-on-the-back-of-the-mouse experiment. I've since moved on doing other work on stem cells.
Cartilage usually doesn't repair appreciably on its own because it is one of the least densely populated tissues in the body. Cartilage is mostly extracellular matrix (ECM) proteins like collagen with a few cells scattered here and there to put out enough protein to maintain the tissue structure. It's also very poorly fed as few blood vessels travel through the cartilage so the few cartilage cells (chondrocytes) present operate at a slow metabolic pace too.
Cartilage has been an early and popular target of tissue engineering efforts. First of all it's a relatively homogenous, simple tissue. Secondly, alot of people have problems with damaged cartilage. What's done is that a porous 'scaffolding' of some material which will break down in the body is molded into the desired shape and then cells are 'seeded' onto the scaffolding with the intention that they will colonize it and grow. The breakdown characteristics are matched as closely as possible to the ECM buildup of proteins released by the cells. Eventually the artificial scaffolding is replaced by tissue. That's what the 'ear' on the back of the mouse is (by implanting it in a mouse, the engineered tissue gets fed in an 'in vivo' environment). Tissue engineered this way has yet to match the physical properties of normally produced cartilage, but there are approaches being investigated to improve these characteristics such as growing the tissue under a physical stress load.
The limiting reagent in this process is the supply of cells for seeding. That's why this story is news. During development, cells take cues from their environment and long range chemical signals to decide where they are and consequently what cell type would be apporpriate to differentiate into. However, not all of the cells in the body move into a final specific cell type. Some of them remain generalized as a pool or reserve of cells. Bone marrow is the easiest example of this. That's what has been taken advantage of here. The chondrocytes in this experiment were developed from stromal cells (not fat cells like the headline states). These are a less specific cell type than either chondrocytes or fat cells (adipocytes). They were grown in a physical environment and fed chemical signals that 'convinced' the cells they needed to become chondrocytes. Figuring out these conditions and signals is a nice piece of work.
There are quite a few pieces of research like this coming to light in the last two years. The direction of research in the stem cell field is moving towards trying to turn 'stem' cells from one particular tissue into developed cells of another tissue. Some labs are even trying to take fully differentiated and presumably committed cells and get them to turn into other cell types, sometimes referred to as 'trans-differentiation'. In that regard, this research isn't earth shattering, it's one more piece of confirmation. Also, if trans-differentiation is confirmed as a general trend, then you could conceivably get chondrocytes from many many different tissues in the body.
As a source for engineered tissue though, this has the practical advantage of being from a readily available source. Nicely done.
Imagine the joy that one station would feel if it caught another doctoring footage and the shit storm that would erupt. Checks, balances, redundancy and indepenant sources keep everyone honest (more or less)
Unless of course all of the major networks are put under pressure by the same large organization. There aren't many organizations with the resources and the reach to do something like that. But some governments do fit the bill.
The experimenters will likely find, when the bacterial cultures have returned to Earth, that one of the cultures now has the ability to extend pseudopods many times their original length, one of them has formed a hard mineralized outer covering, one of them has burst into flames, and one of them has just flat disappeared.
There's even more too it than that. Speaking as someone working in academia on biotech research: without the biotech companies funding research _at universities_, alot of peoples' work would be dead in the water.
Also, companies _do_ share research with university labs. It's not necessarily common, but there is a flow of data between company labs working on proprietary work and university labs working on related projects with the result of both groups getting more work done. The biotech companies get marketable products (which the university labs buy) and the university labs produce more grant-attracting papers (which provide background data for the companies to work from). Everybodies happy.
This reminds me of a story told to me by some of my AE friends. An aerospace company was bought out by a holding company that had mainly owned grocery stores and warehouses before this acquisition. After the purchase of the company, they sent in their accountants to do an audit based on their standard criteria: dollars in profit per square footage of space allocated to each department. They returned with the recomendations of getting rid of the metallurgy and fluid dynamics divisions. The holding company was then surprised when the aerospace company financially imploded.
You can't just look at numbers on paper and pick the bigger (or smaller) one. You need to look at all the particulars of where the numbers came from. Petroleum fuels are used because they are _denser_ sources of energy than solar or wind. Solar and wind may be cheaper per unit depending on how you run the numbers. But you get a larger _total_ amount of energy using Petroleum
That's interesting handing a bill for health problems to the oil companies. Can I send computer monitor companies a bill for all the childrens' eyeglasses in the developed world?
"We are facing a serious social, political and philosophical dilemma: what happens when those of us in our 20s-30s are in our 70s-80s, and the new generation of people are genetically enhanced super-humans?"
Now, what this boils down to is 'I'm concerned that someone will have access to an advantage I can't get at'. Just how did you come to this conclusion?
The current 'easy way' to engineer an organism is to work on germ line and embyonic cells, but 'gene therapy' on _mature_ animals is going on too. When developed to a useable technology, which one (only yet-to-be-born kids or _all_ humans) do you think would be more profitable. I'd say the wider number of applications and more possible customers would push (and is pushing) research into the ability to introduce new traits to anyone at any time in their life.
Of course the next comment down the line would be: "But...but...it would only be available for the RICH!". If this occured to you, then geez, don't you plan on being rich in your life? And what technology didn't start out so rare that it was 'only available for the rich' whether it's cars or computers or cancer treatment? Again, that gleaming gem of additional customers should push the technology and the price down; a kind of 'model T' of gene therapy.
Now, if you're going to start telling me that humans "shouldn't be allowed" to do this. Deal with it. It's my code. Myself. My existence. I will develop myself as I choose.
The Human Genome Project is only to map out the general sequence of genes in the human chromosomes. It's a map that lets you know where a gene might be. It tells you nothing by itself about what that gene may do. That information is put together from biochemical and genetic data.
Genes in Eukaryotes (everything as complex or more than yeast) are individually organized and separated. They have a known 'start of transcription' site that is pretty much universal with slight variations and universal 'stop' sequences. Everything between these two must be a gene. This is called an 'open reading frame' or ORF.
The genes that have been found so far, such as Huntington's etc., have been because someone knew from genetic crosses already that gene A is closely related to B which is on the other side of C. If you know that A is _here_ and C is _there_ and there is only one open reading frame between them, then _that_ must be the location of gene B.
Or, if you've isolated the protein for gene Z, but don't know where the gene is or what nucleic acids code for it, but you know what amino acids compose the protein, then you can do a computer search for possible matches (multiple nucleic acid triplets will code for the same amino acid, CAG and CAA both code for Glutamine etc.)
The human genome project doesn't mean we'll suddenly be able to do new things, it just means they can be done faster and with more surety, less redundancy. It allows two groups to find out they have both been working on the same gene, or that two seperate proteins that people have been working on are actually the same gene spliced in a different way.
Also, the sequencing techniques being used are inherently error prone. The sequencing people aren't shooting for a perfect map, just a percentage of accuracy. After the genome project is 'completed' there will follow _years_ of submissions of corrections and omissions.
If you have concerns (up to you) about various ethical issues surrounding the discovery of this or that gene for this or that condition, the genome project isn't what you need to look at. Honestly Mr Katz, not as a flame or an insult but to make you think, this article is analogous to: Porn is bad! There is porn on the internet. If we shut down/restrict the internet, no one will get/look at porn anymore.
It's not really alternate history, but Tesla makes appearances in Spider Robinson's "Lady Slings The Booze" and "Calahan's Legacy". Mostly in "Lady Slings The Booze".
Something I don't think they made clear in the article is that most of the work that is being done nowadays is with undifferentiated progenitor/stem cells. In the article it sounds as if you are taking heart muscle cells or skin cells or whatever and getting them to position themselves in a static scaffold. This is what the very early work in the late 80s was, as proof of concept. The current work is done with some sort precursor to the cell type that you are interested in and an interactive, biodegradable scaffolding. A cell knows what it is and what it needs to turn into by its environment. The local chemical and protein signals for the tissue type you want are embedded in the scaffolding matrix, the cells adhere to them and decide "A-hah! I'm in the heart and need to be a cardiac cell". The scaffolding is usually made of the same material as resorbable sutures, the tissue eventually eats it after its own extracellular matrix has made it supperfluous.
The cells are refered to as either progenitor cells or stem cells take your pick. There is currently a debate over what makes a cell 'really' a stem cell or not that resembles the discussions of what *really* makes something GPL or not.
These cells do _not_ have to come from fetal tissue. Fetal tissue can be used and it can be argued that using it is better, but it's not necessary. Dr M. Vacanti of the University of Massachusetts is doing work with attempts at regrafting together severed rat spinal chords using progenitor nerve cells harvested from a nerve in the rat's own body.
The blood supply issue is also a matter of signalling. There are chemical calls that cells put out to request that blood vessels grow into their area and provide more food. This usually doesn't happen in tissue engineering because A. you didn't start out with blood vessel cells in the first place and B. you want the cells to grow so you've been feeding them all they can eat anyway. What's usually needed is to artificially add the appropriate signals. Remember the work on the anti-cancer proteins angiostatin and endostatin? D etangling these signals is being worked on.
There are some hospitals that are already looking forward to the time when these techniques are hammered out and publicly availavble by collecting undifferentiated cells from the placenta of newborns and freezing them for the day when the person they belong to may need replacement tissues. Then you get the 'fetal' cell advantage without having another baby get killed for it. If you're having a kid soon, you might ask if the local hospital does this.
As a side note about the start up smoking 'cause it can be replaced idea: Do you *really* want to have to have someone crack you open, rip out your lungs, replace them with custom constructs, and then bill you for all that? And you thought replacing your car's catalytic converter was an expensive inconvenience!
Yes there have been quite a few underground neutrino detectors over the last ten years or so. However all of them keep returning anomalous results. They were intended to measure the level of neutrinos streaming out of the sun from fusion reactions. However, the measurement from the detectors has uniformly been below the predicted level of neutrinos by a factor of three. Originally it was merely thought to be an error in measurement or faulty detectors. But as more facilities and more sensitive detectors were built, the measurement of 1/3 of the neutrinos that calculations predict has gotten increasingly solid.
Perhaps this one will finally shed some light on the 'puzzle'.:)
Hey, sorry for being naive but I'd just wanted to point out to DNA design becoming a reality. Blindly tinkering with nucleotids, disabling/*commenting out*/ a gene or two, patching genes up and observing is one thing. Designing novel organisms is another.
? It appears you may have taken some sort of offence to my post? Anyway... Gene design is a reality right now, has been since the late '80s. Just not on a large scale or at a time frame measured in less than days. This is because of the difficulties in manipulation. It's not 'random' or 'tinkering', just slow. The actual work is the limiting step.
As to designing things, mathematical modeling isn't the only method of approaching it or sometimes even the most practical. The vast majority of modern drug design is done on a chaotic basis; with multiple iterations being screened and recombined until a specific effect is reached. The drug designers have very little idea of the specific path used to move from A to B, but arrived there nonetheless. Also, the semantics you are referring to 1. aren't known and 2. aren't contained in the gene itself. The coding of a gene _only_ contains the sequence of amino acids for a particular protein. The 'information' for the function of a protein is only imputed when the peptide sequence interacts with the unique environment into which it has been released and with itself and assumes a mutable tertiary conformation. It is itself and is interacting with a chaos system; said another way it is empirically impossible to determine all of the variables effecting the system. I thought the same things you are saying when I started protein work, specifically that if one could simply make dynamic electron density maps then the full range of reactions of a given protein could be determined. Not so. It's far more complex than that. There are modeling tools out there, like Sybil and O, but only as visual aids. There are sequence tools like GCG, but only for scanning long strings of symbols and comparing them. If all possible factors could be determined and accounted for in a program, then yes you could model a cell, but it would be such a herculean task that it would be impractical in comparisson to the method used to produce the original proteins: selection towards the desired effect. Like I said, 'Not any time soon'. It's easier to just do it, then see where it came from than to try and guess where it's going to go. The same problem shows up in a lot of fluid dynamics. Two of my best friends are Aerospace Engineers and they continually complain about how aerodynamic models continually fail to live up to actual wind tunnel tests on mock ups. The programs help, but they miss subtle things. There's a lot of talk in the biotech community about 'moving towards more rational drug design'. But again this is refining the selection criteria. As to 'grasping the concept of a gene' causing a 'stack overflow' in the human brain, most of the Proffessors, Post-docs, and Students on this floor would object to that, including me since I've got a modification of hemoglobin being produced by bacterial culture in the shaker right now... Again, once it's there it's quite possible to comprehend but you have to have it there first to know that. I can guess what this iteration is going to produce, which is why it's being tried, but we won't know until it's done. --- BTW, it's great if the actuation of genes is a probability and function of chemical equilibrium (or the probabilistic fun. of;) since you can compute that.
It's called an equilibrium constant. K such that for A + B -> C, K = [C]/[A][B] where [ ] represents concentration. Further ^Go = -RTln(K) where R is the gas constant, T is temperature in degrees Kelvin, and ^Go is the Gibb's Free Energy under standard conditions. With one more step ^Go=^Ho-T^So where T is again temperature and ^Ho and ^So are the standard enthalphy and standard entropy respectively. Nice, solid, well-trodd mathematical basis, yet Kd (binding equilibrium) for proteins is _only_ determined experimentally. Developmental systems do not necessarily assume order. They tend to _approach_ order as seen in homeostasis, but do not achieve it until all inputs stop. In a living system this event is death and it doesn't matter anymore.
In some previous/. discussion, it'd been expressed that genetic engineering is still unlike software engineering in which one designs systems from scratch or in most cases from some level above that.
That might change.
Not any time soon. The difficulty with gene work right now is that you can't do fast large scale editing of any kind. Small, minor changes are quite practical which means you can modify and move around existing genes. Even this though is a process of a few days from start to finish. You don't decide you want to change something and type it out on a keyboard. Without a template to start from, chains of nucleotides are usually only constructed in pieces of 100 bases or less. This is enough for the 'primers' used for the start and finish of a polymerase chain reaction (PCR) amplification, but would make only a teensy fraction of a given gene which may cover a few thousand base pairs or more in the genome. You can't really link chains of a hundred or so together sequentially either because it's too difficult to get right. Use of existing genes and single base pair changes are usually the way things are done.
If someone were to come up with a higher resolution, more directed method for determining sequence, handling and manipulating the DNA chain without damaging it (it snaps easy!); i.e. if we could see what we were doing in real time, then 'Bio-Hacking' [I actually think of myself that way sometimes] would shift into high gear.
Taking a microbiology class wouldn't net you much on this scale. It's more concerned with types, care, and feeding of cultured cells and single-celled organisms ("this is a car"). Molecular biology is the large scale molecular structure, cytoskeleton, chromatin, and manipulation of same ("this is an engine"). Biochemistry is the small scale function of individual amino-acids in proteins, bases in DNA, organic co-factors, reaction mechanisms, interactions with chemical environment, etc ("this is combustion in the cylinder").
'Bio-hackers' probably won't borrow all that much from modern software design. The actuation for the genes via the proteins they code for is more a probability and function of chemical equilibrium than an all-or-nothing program execution. Though as an aside: with gene systems layering of one function on the previous abilities of another which only works with the presence of a third, there is a striking resemblance to a Unix system. Chaotic evolution in both cases:).
As for gene-libraries being General Public Liscense... Er, alot of them already are:
The thought that occurs to me when I see things like this, is that people are saying they need to reinvent the wheel, and this time give it square corners for improved safety.
The groups that have put together these projects have certainly made a chemical accomplishment, but why is everyone looking to this as a 'nano-motor'? Bacterial flagella already exist, function off of ATP, they average 0.25 micrometers (250 nanometers) in diameter, come in a variety of lengths, have been clocked at 2400 rpm, can be assembled in minutes from informational schematics in large quantities, and have repair and maintenance facilities preexisting. To me it's like hearing someone say they've assembled something they call ENIAC and that it is unquestionably superior to the SGI I use for molecular modeling...
Nanomotors, switches, levers, atomic pumps, and power stations already exist. I don't understand why the 'Nano' researchers aren't using them.
'Machines' don't have to be made of metal, after all the two in the article aren't.
Yes. While we have good statistical data to use for mutations and "genetic drift" in most chromosomal DNA, applying that to mtDNA is a bit questionable since it exists in a different chemical and enzymatic environment. Similar effects can be seen with the Y chromosome. Since the Y chromosome, with normal genetic segragation, never has a complementary chromosome to pair with, it lacks the final last ditch repair mechanism wherein the homoloqous chromosomes synapse and trade half their strands in hopes of patching over a damaged sequence. This has led to some rather bizarre gene arrangements accumulating over time like eight copies of the same gene in a row. Human mtDNA only codes for 13 genes. All other proteins used are imported from the cytosol. For sequenceing purposes, you can have a rather rapid mutation rate with individual bases changing. For genetic purposes you don't see much change in protein function because any large change tends to be catastrophic.
Okay, in hair and nail clippings there is no DNA. They are both composed of proteins. Skin is a bit problematic in that the (surface) cells are already dead. You can still get some sequence from them using the Polymerase Chain Reaction (PCR) protocol, but that's more diagnostic than clinical. PCR has been developed to the point that, with the highest end setups, only one copy of the target sequence needs to be there for you to amplify and detect it.
DNA is usually stored by extracting it from cells, supporting it in a buffer solution of correct pH and concentration, and freezing it at -80C. The thing is that while DNA as a molecule is rather robust, DNA as a storage medium is not. The information in it is rather fragile under chemical attack (free radicals or nitrites) enzymatic attack (from DNAse enzymes say) or harsh conditions (UV light). You only have to break two chemical bonds to sever the molecule. That's just as permanent as cutting a video tape with a pair of scissors. The best place to store DNA is in a living, respirating, cell that will take care of the DNA and make repairs to it.
As to how long DNA can be stored with the sequence unaltered, we don't know yet. Watson and Crick published their paper about the physical structure of the DNA double helix in 1953. Large scale formal work with the information coded by DNA has only kicked into high gear since the late '70s, early '80s with PCR, Sanger sequencing, and restriction (DNA cutting) endonucleases. It's barely been 20 years so far.
After thinking about it for a minute, the lack of mtDNA from Dolly's 'genetic' mother makes sense. Since only the female parent's mitochondria are present in offspring, there has to be a mechanism for recognizing 'native' mitochondria and either destroying or directing to self destruction 'foreign' mitochondria. All functioning spermatocytes from every animal contain at least one mitochondrion. It's usually coiled about the protein "engine housing" for the flagelum that drives the cell. So every sperm/egg fusion event brings with it a 'foreign' mitochondrion, whether it is easily liberated into the egg cell cytosol or not. So what is the mechanism? A possible MHC for cellular organelles or something simpler?
Slashdot Mirror
This is the same mechanism of action as the Complement System used by your Immune System. Antibodies recognize and bind to a bacteria and recruit the first part of the system, which inserts itself into the cell membrane. The first part of the system recruits other proteins, which recruit other proteins, etc., until a ring of proteins is made in the cell membrane. Since the concentration of salt, protein, sugar, and everything else is higher inside the cell than outside, water rushes in through the tiny hole and the cell membrane ruptures from the rapid expansion of volume.
Here's a brief link or two
Disappointing, ne?
I thought that any damage to cartilage caused it to calcify into bone after a long period of painful tenderness. I'm a wrestler, thereby being very familiar with cauliflower ear. For those who don't know, a painful condition whereby the cartilage of the ear becomes tender and inflamed after being pounded upon by a competitor (also developed from talking on the phone too much). Older wrestlers tend to have knobby, hard ear lobes. How do you put new cartilage in without causing damage and the corresponding calcification?
The condition you are talking about isn't really a transformation into bone material. Also, it's not 'any' trauma that will result in it. You need wide spread crushing damage to the tissue to get the necessary disruption. A small laceration such as from a scalpel shouldn't do enough damage to starve out all the local cells.
Here's a little more information about it. Note the bit about 'treatment'.
Hope this helps.
Okay, I've actually worked in the Vacanti Tissue Engineering laboratory, the lab that did the Ear-on-the-back-of-the-mouse experiment. I've since moved on doing other work on stem cells.
Cartilage usually doesn't repair appreciably on its own because it is one of the least densely populated tissues in the body. Cartilage is mostly extracellular matrix (ECM) proteins like collagen with a few cells scattered here and there to put out enough protein to maintain the tissue structure. It's also very poorly fed as few blood vessels travel through the cartilage so the few cartilage cells (chondrocytes) present operate at a slow metabolic pace too.
Cartilage has been an early and popular target of tissue engineering efforts. First of all it's a relatively homogenous, simple tissue. Secondly, alot of people have problems with damaged cartilage. What's done is that a porous 'scaffolding' of some material which will break down in the body is molded into the desired shape and then cells are 'seeded' onto the scaffolding with the intention that they will colonize it and grow. The breakdown characteristics are matched as closely as possible to the ECM buildup of proteins released by the cells. Eventually the artificial scaffolding is replaced by tissue. That's what the 'ear' on the back of the mouse is (by implanting it in a mouse, the engineered tissue gets fed in an 'in vivo' environment). Tissue engineered this way has yet to match the physical properties of normally produced cartilage, but there are approaches being investigated to improve these characteristics such as growing the tissue under a physical stress load.
The limiting reagent in this process is the supply of cells for seeding. That's why this story is news. During development, cells take cues from their environment and long range chemical signals to decide where they are and consequently what cell type would be apporpriate to differentiate into. However, not all of the cells in the body move into a final specific cell type. Some of them remain generalized as a pool or reserve of cells. Bone marrow is the easiest example of this. That's what has been taken advantage of here. The chondrocytes in this experiment were developed from stromal cells (not fat cells like the headline states). These are a less specific cell type than either chondrocytes or fat cells (adipocytes). They were grown in a physical environment and fed chemical signals that 'convinced' the cells they needed to become chondrocytes. Figuring out these conditions and signals is a nice piece of work.
There are quite a few pieces of research like this coming to light in the last two years. The direction of research in the stem cell field is moving towards trying to turn 'stem' cells from one particular tissue into developed cells of another tissue. Some labs are even trying to take fully differentiated and presumably committed cells and get them to turn into other cell types, sometimes referred to as 'trans-differentiation'. In that regard, this research isn't earth shattering, it's one more piece of confirmation. Also, if trans-differentiation is confirmed as a general trend, then you could conceivably get chondrocytes from many many different tissues in the body.
As a source for engineered tissue though, this has the practical advantage of being from a readily available source. Nicely done.
Anti goverment paranoia is downright unamerican?
Absolutely right! Why I'd wonder if maybe all those encryptors are actually pinko commie traitors.
We'd better scan their mail and hard disks. We need to find out how many other communists they know.
Hey wait a minute....
Unless of course all of the major networks are put under pressure by the same large organization. There aren't many organizations with the resources and the reach to do something like that. But some governments do fit the bill.
The experimenters will likely find, when the bacterial cultures have returned to Earth, that one of the cultures now has the ability to extend pseudopods many times their original length, one of them has formed a hard mineralized outer covering, one of them has burst into flames, and one of them has just flat disappeared.
There's even more too it than that. Speaking as someone working in academia on biotech research: without the biotech companies funding research _at universities_, alot of peoples' work would be dead in the water.
Also, companies _do_ share research with university labs. It's not necessarily common, but there is a flow of data between company labs working on proprietary work and university labs working on related projects with the result of both groups getting more work done. The biotech companies get marketable products (which the university labs buy) and the university labs produce more grant-attracting papers (which provide background data for the companies to work from). Everybodies happy.
This reminds me of a story told to me by some of my AE friends. An aerospace company was bought out by a holding company that had mainly owned grocery stores and warehouses before this acquisition. After the purchase of the company, they sent in their accountants to do an audit based on their standard criteria: dollars in profit per square footage of space allocated to each department. They returned with the recomendations of getting rid of the metallurgy and fluid dynamics divisions. The holding company was then surprised when the aerospace company financially imploded.
You can't just look at numbers on paper and pick the bigger (or smaller) one. You need to look at all the particulars of where the numbers came from.
Petroleum fuels are used because they are _denser_ sources of energy than solar or wind. Solar and wind may be cheaper per unit depending on how you run the numbers. But you get a larger _total_ amount of energy using Petroleum
That's interesting handing a bill for health problems to the oil companies. Can I send computer monitor companies a bill for all the childrens' eyeglasses in the developed world?
Okay, let's look at that statement for a minute:
"We are facing a serious social, political and philosophical dilemma: what happens when those of us in our 20s-30s are in our 70s-80s, and the new generation of people are genetically enhanced super-humans?"
Now, what this boils down to is 'I'm concerned that someone will have access to an advantage I can't get at'. Just how did you come to this conclusion?
The current 'easy way' to engineer an organism is to work on germ line and embyonic cells, but 'gene therapy' on _mature_ animals is going on too. When developed to a useable technology, which one (only yet-to-be-born kids or _all_ humans) do you think would be more profitable. I'd say the wider number of applications and more possible customers would push (and is pushing) research into the ability to introduce new traits to anyone at any time in their life.
Of course the next comment down the line would be: "But...but...it would only be available for the RICH!". If this occured to you, then geez, don't you plan on being rich in your life? And what technology didn't start out so rare that it was 'only available for the rich' whether it's cars or computers or cancer treatment? Again, that gleaming gem of additional customers should push the technology and the price down; a kind of 'model T' of gene therapy.
Now, if you're going to start telling me that humans "shouldn't be allowed" to do this. Deal with it. It's my code. Myself. My existence. I will develop myself as I choose.
The Human Genome Project is only to map out the general sequence of genes in the human chromosomes. It's a map that lets you know where a gene might be. It tells you nothing by itself about what that gene may do. That information is put together from biochemical and genetic data.
Genes in Eukaryotes (everything as complex or more than yeast) are individually organized and separated. They have a known 'start of transcription' site that is pretty much universal with slight variations and universal 'stop' sequences. Everything between these two must be a gene. This is called an 'open reading frame' or ORF.
The genes that have been found so far, such as Huntington's etc., have been because someone knew from genetic crosses already that gene A is closely related to B which is on the other side of C. If you know that A is _here_ and C is _there_ and there is only one open reading frame between them, then _that_ must be the location of gene B.
Or, if you've isolated the protein for gene Z, but don't know where the gene is or what nucleic acids code for it, but you know what amino acids compose the protein, then you can do a computer search for possible matches (multiple nucleic acid triplets will code for the same amino acid, CAG and CAA both code for Glutamine etc.)
The human genome project doesn't mean we'll suddenly be able to do new things, it just means they can be done faster and with more surety, less redundancy. It allows two groups to find out they have both been working on the same gene, or that two seperate proteins that people have been working on are actually the same gene spliced in a different way.
Also, the sequencing techniques being used are inherently error prone. The sequencing people aren't shooting for a perfect map, just a percentage of accuracy. After the genome project is 'completed' there will follow _years_ of submissions of corrections and omissions.
If you have concerns (up to you) about various ethical issues surrounding the discovery of this or that gene for this or that condition, the genome project isn't what you need to look at.
Honestly Mr Katz, not as a flame or an insult but to make you think, this article is analogous to: Porn is bad! There is porn on the internet. If we shut down/restrict the internet, no one will get/look at porn anymore.
It's not really alternate history, but Tesla makes appearances in Spider Robinson's "Lady Slings The Booze" and "Calahan's Legacy". Mostly in "Lady Slings The Booze".
Something I don't think they made clear in the article is that most of the work that is being done nowadays is with undifferentiated progenitor/stem cells. In the article it sounds as if you are taking heart muscle cells or skin cells or whatever and getting them to position themselves in a static scaffold. This is what the very early work in the late 80s was, as proof of concept. The current work is done with some sort precursor to the cell type that you are interested in and an interactive, biodegradable scaffolding. A cell knows what it is and what it needs to turn into by its environment. The local chemical and protein signals for the tissue type you want are embedded in the scaffolding matrix, the cells adhere to them and decide "A-hah! I'm in the heart and need to be a cardiac cell". The scaffolding is usually made of the same material as resorbable sutures, the tissue eventually eats it after its own extracellular matrix has made it supperfluous.
The cells are refered to as either progenitor cells or stem cells take your pick. There is currently a debate over what makes a cell 'really' a stem cell or not that resembles the discussions of what *really* makes something GPL or not.
These cells do _not_ have to come from fetal tissue. Fetal tissue can be used and it can be argued that using it is better, but it's not necessary. Dr M. Vacanti of the University of Massachusetts is doing work with attempts at regrafting together severed rat spinal chords using progenitor nerve cells harvested from a nerve in the rat's own body.
The blood supply issue is also a matter of signalling. There are chemical calls that cells put out to request that blood vessels grow into their area and provide more food. This usually doesn't happen in tissue engineering because A. you didn't start out with blood vessel cells in the first place and B. you want the cells to grow so you've been feeding them all they can eat anyway. What's usually needed is to artificially add the appropriate signals. Remember the work on the anti-cancer proteins angiostatin and endostatin? D etangling these signals is being worked on.
There are some hospitals that are already looking forward to the time when these techniques are hammered out and publicly availavble by collecting undifferentiated cells from the placenta of newborns and freezing them for the day when the person they belong to may need replacement tissues. Then you get the 'fetal' cell advantage without having another baby get killed for it. If you're having a kid soon, you might ask if the local hospital does this.
As a side note about the start up smoking 'cause it can be replaced idea: Do you *really* want to have to have someone crack you open, rip out your lungs, replace them with custom constructs, and then bill you for all that? And you thought replacing your car's catalytic converter was an expensive inconvenience!
Yes there have been quite a few underground neutrino detectors over the last ten years or so. However all of them keep returning anomalous results. They were intended to measure the level of neutrinos streaming out of the sun from fusion reactions. However, the measurement from the detectors has uniformly been below the predicted level of neutrinos by a factor of three. Originally it was merely thought to be an error in measurement or faulty detectors. But as more facilities and more sensitive detectors were built, the measurement of 1/3 of the neutrinos that calculations predict has gotten increasingly solid.
:)
Perhaps this one will finally shed some light on the 'puzzle'.
Hey, sorry for being naive but I'd just wanted to point out to DNA design becoming a reality. Blindly tinkering with nucleotids, disabling /*commenting out*/ a gene or two, patching genes up and observing is one thing. Designing novel organisms is another.
;) since you can compute that.
? It appears you may have taken some sort of offence to my post? Anyway... Gene design is a reality right now, has been since the late '80s. Just not on a large scale or at a time frame measured in less than days. This is because of the difficulties in manipulation. It's not 'random' or 'tinkering', just slow. The actual work is the limiting step.
As to designing things, mathematical modeling isn't the only method of approaching it or sometimes even the most practical. The vast majority of modern drug design is done on a chaotic basis; with multiple iterations being screened and recombined until a specific effect is reached. The drug designers have very little idea of the specific path used to move from A to B, but arrived there nonetheless. Also, the semantics you are referring to 1. aren't known and 2. aren't contained in the gene itself. The coding of a gene _only_ contains the sequence of amino acids for a particular protein. The 'information' for the function of a protein is only imputed when the peptide sequence interacts with the unique environment into which it has been released and with itself and assumes a mutable tertiary conformation. It is itself and is interacting with a chaos system; said another way it is empirically impossible to determine all of the variables effecting the system.
I thought the same things you are saying when I started protein work, specifically that if one could simply make dynamic electron density maps then the full range of reactions of a given protein could be determined. Not so. It's far more complex than that. There are modeling tools out there, like Sybil and O, but only as visual aids. There are sequence tools like GCG, but only for scanning long strings of symbols and comparing them.
If all possible factors could be determined and accounted for in a program, then yes you could model a cell, but it would be such a herculean task that it would be impractical in comparisson to the method used to produce the original proteins: selection towards the desired effect. Like I said, 'Not any time soon'.
It's easier to just do it, then see where it came from than to try and guess where it's going to go.
The same problem shows up in a lot of fluid dynamics. Two of my best friends are Aerospace Engineers and they continually complain about how aerodynamic models continually fail to live up to actual wind tunnel tests on mock ups. The programs help, but they miss subtle things.
There's a lot of talk in the biotech community about 'moving towards more rational drug design'. But again this is refining the selection criteria.
As to 'grasping the concept of a gene' causing a 'stack overflow' in the human brain, most of the Proffessors, Post-docs, and Students on this floor would object to that, including me since I've got a modification of hemoglobin being produced by bacterial culture in the shaker right now... Again, once it's there it's quite possible to comprehend but you have to have it there first to know that. I can guess what this iteration is going to produce, which is why it's being tried, but we won't know until it's done.
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BTW, it's great if the actuation of genes is a probability and function of chemical equilibrium (or the probabilistic fun. of
It's called an equilibrium constant. K such that for A + B -> C, K = [C]/[A][B] where [ ] represents concentration. Further ^Go = -RTln(K) where R is the gas constant, T is temperature in degrees Kelvin, and ^Go is the Gibb's Free Energy under standard conditions. With one more step ^Go=^Ho-T^So where T is again temperature and ^Ho and ^So are the standard enthalphy and standard entropy respectively. Nice, solid, well-trodd mathematical basis, yet Kd (binding equilibrium) for proteins is _only_ determined experimentally.
Developmental systems do not necessarily assume order. They tend to _approach_ order as seen in homeostasis, but do not achieve it until all inputs stop. In a living system this event is death and it doesn't matter anymore.
In some previous /. discussion, it'd been expressed that genetic engineering is still unlike software engineering in which one designs systems from scratch or in most cases from some level above that.
:).
That might change.
Not any time soon. The difficulty with gene work right now is that you can't do fast large scale editing of any kind. Small, minor changes are quite practical which means you can modify and move around existing genes. Even this though is a process of a few days from start to finish. You don't decide you want to change something and type it out on a keyboard. Without a template to start from, chains of nucleotides are usually only constructed in pieces of 100 bases or less. This is enough for the 'primers' used for the start and finish of a polymerase chain reaction (PCR) amplification, but would make only a teensy fraction of a given gene which may cover a few thousand base pairs or more in the genome. You can't really link chains of a hundred or so together sequentially either because it's too difficult to get right. Use of existing genes and single base pair changes are usually the way things are done.
If someone were to come up with a higher resolution, more directed method for determining sequence, handling and manipulating the DNA chain without damaging it (it snaps easy!); i.e. if we could see what we were doing in real time, then 'Bio-Hacking' [I actually think of myself that way sometimes] would shift into high gear.
Taking a microbiology class wouldn't net you much on this scale. It's more concerned with types, care, and feeding of cultured cells and single-celled organisms ("this is a car"). Molecular biology is the large scale molecular structure, cytoskeleton, chromatin, and manipulation of same ("this is an engine"). Biochemistry is the small scale function of individual amino-acids in proteins, bases in DNA, organic co-factors, reaction mechanisms, interactions with chemical environment, etc ("this is combustion in the cylinder").
'Bio-hackers' probably won't borrow all that much from modern software design. The actuation for the genes via the proteins they code for is more a probability and function of chemical equilibrium than an all-or-nothing program execution. Though as an aside: with gene systems layering of one function on the previous abilities of another which only works with the presence of a third, there is a striking resemblance to a Unix system. Chaotic evolution in both cases
As for gene-libraries being General Public Liscense... Er, alot of them already are:
http://www.ncbi.nlm.nih.gov/BLAST/
http://blast.wustl.edu/
http://www.tigr.org/tdb/
The thought that occurs to me when I see things like this, is that people are saying they need to reinvent the wheel, and this time give it square corners for improved safety.
The groups that have put together these projects have certainly made a chemical accomplishment, but why is everyone looking to this as a 'nano-motor'? Bacterial flagella already exist, function off of ATP, they average 0.25 micrometers (250 nanometers) in diameter, come in a variety of lengths, have been clocked at 2400 rpm, can be assembled in minutes from informational schematics in large quantities, and have repair and maintenance facilities preexisting. To me it's like hearing someone say they've assembled something they call ENIAC and that it is unquestionably superior to the SGI I use for molecular modeling...
Nanomotors, switches, levers, atomic pumps, and power stations already exist. I don't understand why the 'Nano' researchers aren't using them.
'Machines' don't have to be made of metal, after all the two in the article aren't.
Yes. While we have good statistical data to use for mutations and "genetic drift" in most chromosomal DNA, applying that to mtDNA is a bit questionable since it exists in a different chemical and enzymatic environment. Similar effects can be seen with the Y chromosome. Since the Y chromosome, with normal genetic segragation, never has a complementary chromosome to pair with, it lacks the final last ditch repair mechanism wherein the homoloqous chromosomes synapse and trade half their strands in hopes of patching over a damaged sequence. This has led to some rather bizarre gene arrangements accumulating over time like eight copies of the same gene in a row. Human mtDNA only codes for 13 genes. All other proteins used are imported from the cytosol. For sequenceing purposes, you can have a rather rapid mutation rate with individual bases changing. For genetic purposes you don't see much change in protein function because any large change tends to be catastrophic.
Okay, in hair and nail clippings there is no DNA. They are both composed of proteins. Skin is a bit problematic in that the (surface) cells are already dead. You can still get some sequence from them using the Polymerase Chain Reaction (PCR) protocol, but that's more diagnostic than clinical. PCR has been developed to the point that, with the highest end setups, only one copy of the target sequence needs to be there for you to amplify and detect it.
DNA is usually stored by extracting it from cells, supporting it in a buffer solution of correct pH and concentration, and freezing it at -80C. The thing is that while DNA as a molecule is rather robust, DNA as a storage medium is not. The information in it is rather fragile under chemical attack (free radicals or nitrites) enzymatic attack (from DNAse enzymes say) or harsh conditions (UV light). You only have to break two chemical bonds to sever the molecule. That's just as permanent as cutting a video tape with a pair of scissors. The best place to store DNA is in a living, respirating, cell that will take care of the DNA and make repairs to it.
As to how long DNA can be stored with the sequence unaltered, we don't know yet. Watson and Crick published their paper about the physical structure of the DNA double helix in 1953. Large scale formal work with the information coded by DNA has only kicked into high gear since the late '70s, early '80s with PCR, Sanger sequencing, and restriction (DNA cutting) endonucleases. It's barely been 20 years so far.
But what counts as a 'stupid genetic problem'? Anything that isn't the result of your enviroment? Who gets to decide if something is a problem?
I do.
It's my code. I can recompile myself if I want.
After thinking about it for a minute, the lack of mtDNA from Dolly's 'genetic' mother makes sense. Since only the female parent's mitochondria are present in offspring, there has to be a mechanism for recognizing 'native' mitochondria and either destroying or directing to self destruction 'foreign' mitochondria. All functioning spermatocytes from every animal contain at least one mitochondrion. It's usually coiled about the protein "engine housing" for the flagelum that drives the cell. So every sperm/egg fusion event brings with it a 'foreign' mitochondrion, whether it is easily liberated into the egg cell cytosol or not. So what is the mechanism? A possible MHC for cellular organelles or something simpler?