It's not blood that makes red meat red; it's the myoglobin concentration in the muscle, which in turn relates to that muscle's use of oxygen. Meat from adult mammalian tissues on average contains about ten times as much myoglobin as meat from poultry. In poultry, meat can be further differentiated into "light and dark" meat based on what part of the bird it comes from- muscles in the wings, thighs, and legs need more oxygen to sustain activity, have more myoglobin, and are darker- but still have less myoglobin than most beef.
Draining blood out of the meat isn't going to change its color; the myoglobin is within the muscle itself. The color of meat can be affected by the animal's age and diet however: veal, for instance, can be nearly white in color when taken from calves fed only on milk. Myoglobin, like its bloodborne relative hemoglobin, does contain iron, and does represent a major dietary source if you eat red meat.
Want to know what the copyright is really being asserted on? Here's a picture of the back of an Omega Seamaster watch, the article in question. (No affiliation with the site, just what Google turned up first). Omega isn't asserting copyright on their main logo; they've been using it for over a century. Also, it's the Greek letter omega, not exactly a highly stylized and unique design. They aren't asserting copyright on the Seamaster seahorse that dominates the back, though you'd think that desgin qualifies as the best example of artistic authorship on the watch. Omega has been making Seamasters for about 60 years, so I would think that image could still be copyrighted. But that's not what Omega is claiming infringement on either.
The artwork Omega is enforcing a copyright on is that pattern of circles with an omega in it, just to the right of the pronounced Omega logo and above the "825" in the linked picture. That little doodle is about 0.5 centimeters in diameter, and apparently Omega is arguing that when you buy an Omega Seamaster, you are buying an authorized reproduction of that triumph of human artistic endeavor for the agreed-upon price of two thousand dollars. Omega just happens to be so generous as to frame your purchase with a diving watch.
In this case, the stamp on the watch is being considered as "artwork," which falls under copyright. From the FAQ on the US Copyright Office page:
Copyright does not protect names, titles, slogans, or short phrases. In some cases, these things may be protected as trademarks. Contact the U.S. Patent & Trademark Office, 800-786-9199, for further information. However, copyright protection may be available for logo artwork that contains sufficient authorship. In some circumstances, an artistic logo may also be protected as a trademark.
In particular, it mostly illustrates that in flatworms, body plan genes can be routinely reactivated throughout an organism's life. Most multicellular animals on Earth have a series of genes known as Hox or homeobox genes whose role is to determine the correct placement of structures on the body- depending on the form of the organism, "structures" can mean things like organs, limbs, eyes, tails, etc. The activity of these genes is so important that they tend to have been strongly conserved sequences throughout time- we have some Hox genes that are very similar to those in flies, for instance. This conservation is helped along by the fact that the Hox genes ultimately work by signaling other genes to work; the signaling cascade functions whether the signal is for the development of insect wings or for bird wings.
According to the paper, the signaling involved in the development of the posterior end of planaria (Wnt/beta-catenin) had already been identified; the discovery of Smed-prep explains how the development of anterior structures (the trunk and head of the animal) are regulated. In addition, they found that the anterior and posterior pathways normally work in opposition (to avoid growing a tail on the head or head on the tail), and by silencing the posterior signaling, then activating head regeneration, a head would grow at both ends.
From what we know of human Hox genes, the picture is not so simple- even at the most basic level of developmental organization there are several genes that direct development of the head, so there isn't a master gene we can reactivate to grow an ectopic head, but many of the same developmental pathways (Wnt, for instance) are the same or similar across organisms.
That's because, contrary to what the summary says, this is a cosmic ray detector, not a gamma ray detector. The point of the big magnet is that there will be charged particles streaming through that can be steered by a magnetic field (and so identified). Of course, most cosmic rays are protons, but a significant fraction are alpha particles, and one of the major objectives of the experiment is to look for alpha antiparticles (antihelium nuclei, in other words).
Just throwing a question out there: What's holding back the use of high critical-temperature superconductors in applications like the AMS magnet? Helium cooling is a vital, yet difficult and expensive proposition for many high-profile physics projects, to say nothing of innummerable NMR and MRI magnets out there. I realize that as ceramic-type substances, cuprate superconductors aren't as easily drawn into wire as the niobium alloys commonly used, but it seems like those technical challenges are worth dealing with in order to cool with liquid nitrogen rather than liquid helium. Particularly the superfluid helium that was planned for AMS- that stuff abhors a container. Is there some other physical limitation to cuprates that I'm missing, or is it just that the multi-decade nature of the big projects have kept them from adopting newer materials?
I found a nice little illustration of the effect temperature has on the equilibrium of this reaction here. The calculation is actually for the related reaction using carbon (as coke) instead of methane, but the equilibrium constants are about equal for the temperatures discussed here. At atmospheric conditions on Earth, the equilibrium can be considered as shifted completely to the left. Virtually no carbon monoxide is produced from this reaction at temperatures less than about 600K. At a temperature of 956.7K, the levels of carbon and carbon monoxide are equal, and at higher temperatures, carbon monoxide is On GJ 436b, with a temperature of 800K, the equilibrium should still strongly disfavor CO production, and the calculation suggests that there should be around 13.6 times as much carbon (or methane in the case of GJ 436b) as there is carbon monoxide.
However, the researchers determined that "GJ 436b's atmosphere is abundant in CO and deficient in methane (CH4) by a factor of ~7,000." The only way the planet could have gotten an atmosphere like that through this reaction equilibrium alone is if its temperature is really around 2000K instead of 800K. The researchers therefore argue that it's far more likely that some other mechanism is disrupting this equilibrium, like polymerization of methane that pulls it out of the system. In their Nature paper, they include a a chart of the atmospheric ratios of gas giants, both in our solar system and exoplanets; nothing else known has a CH4/CO ratio like that seen for GJ 436b.
The reaction being looked at here is interesting because it is the same reaction used on Earth in the steam reforming of methane to produce hydrogen, with the same equilibrium issues. Methane (or many other hydrocarbons) can be reacted with water vapor to produce carbon monoxide and hydrogen. However, this reaction is not going to proceed forward under normal atmospheric conditions on Earth, and at least was not expected to proceed forward under the conditions of GJ 436b. The reaction needs enough energy put in to break apart methane and water molecules before their components can be recombined to form CO and hydrogen. In the absence of catalysts, you should expect this step to occur at temperatures no lower than around 920K, while GJ 436b is believed to be at 800K.
We can look at some of the possibilities of what could be happening on GJ 436b:
CH4 + H2O is in equilibrium with CO + 3 H2 (with a change in enthalpy of +206kJ/mol)
The temperature of GJ 436b could be higher than what is measured. If the temperature is actually above around 920K, then the necessary activation energy is present to get this reaction headed to the right side of the equation. This solves the mystery, but then opens a new mystery of why the temperature measurement is off by over 100K.
A reaction product is rapidly being taken away after formation. If either carbon monoxide or hydrogen were somehow continuously removed from the site of the reaction, the reaction equilibrium would keep favoring the generation of more CO and H2 rather than reversing to make more methane and water. This is what the suggestion of "vertical mixing" is alluding to: if the "steam methane reforming" reaction is isolated to one region of the atmosphere, but the reaction products rapidly migrate to another, then the reaction equilibrium makes sense.
When steam reforming of methane is done as an industrial process on Earth, the reactions are carried out at temperatures of about 700-800K, right around the temperature of GJ 436b. The necessary activation energy is lowered by metal catalysts (usually nickel) Could the interaction of the atmosphere with the rocky core be catalyzing this reaction? It's unlikely that there's enough surface area to transform the whole atmosphere in this manner, but it's an intriguing possibility.
Or much eariler, Kurt Vonnegut's Player Piano (1952), where the giant computer EPICAC XIV resided in Carlsbad Caverns. I guess Google's servers won't require an army of workers to swap out vacuum tubes though.
The US participates via a parallel project in The Cancer Genome Atlas administered by the National Institutes of Health, which while remaining independent of the international project, shares data and tailors it's foci to not overlap with those of the ICGC.
It wouldn't be demoted in terms of moving out of its present category. I think the sense is more that the class of dwarf planets, which now comprise only five known objects (Ceres, Pluto, Haumea, Makemake, and Eris) would admit many more members if the minimum radius necessary for the category were revised far downward. The argument then is that the category would be somehow less "special" if there were hundreds or thousands of dwarf planets instead of a handful.
At least from an aesthetic viewpoint, I actually like this proposed new definition though- the size at which an object forms a spherical shape under its own gravity seems like a significant transition. I feel that if an icy sphere the size of Enceladus were discovered out in the Kuiper belt, an assignation of "dwarf planet" would be logical, but such an object would be considered too small under the current IAU definition.
There's a lot of work being done in this area right now- with good reason; there's tremendous potential, and the advance highlighted here is more of an incremental step in a rapidly maturing field than a breakthrough. As the parent notes, Dr. Fiona Wood pioneered a spray-on cell suspension over 15 years ago. She eventually founded a company (now called Avita Medical) which has commercialized this technology. In the last decade, it has been discovered that with minimal modification, an off-the-shelf inkjet printer can print living cells- this article is an example.
The story here from Wake Forest is apparently a successful test of using an inkjet to print directly on wounds using multiple cell types. The group reported these results at the Translational Regenerative Medicine Forum which took place the last few days. Who else happened to be at that forum? Avita Medical, where Dr. Wood still sits on the board.
Apparently, this same guy had a similar project called "Dodgeball" which Google bought out in 2005- and then killed in 2009 to replace with Google Latitude. I don't know how much he got for Dodgeball, but it may be that he really can afford to walk away from offers now. Both Dodgeball and "Foursquare" are/were location-based social networking services for mobile devices- Foursquare appears to tweak the concept by turning it into a sort of Zynga-style game where you earn awards for using the service. 100 million bucks for that.
All right, I may have gone a little overboard with the jargon there. All I was trying to say is that by using hydrogenosomes rather than mitochondria, this organism misses out on a lot of the available chemical energy in its food. In most enviroments on earth, a multicellular organism that tried to live like this would be strongly outcompeted by its oxygen-gulping rivals. However, living attached to anoxic sediments at the seafloor, this organism has little need for mobility, food is abundant from things dying above (the journal article uses the charming term "rain of cadavers"), and anything that competes with it must also cope with the lack of oxygen.
It actually points to the former- a multicellular aerobe adapting to an anoxic niche. The particular evidence is in its use of hydrogenosomes. Hydrogenosomes are believed to be a degenerate form of the aerobic mitochondrion. They have the same double membrane structure, import pyruvate from glycolysis, and include various other components like coenzyme A and ferredoxin. They however lack most of the electron carriers and enzymes of the citric acid cycle and oxidative phosphorylation. The metazoans discovered are known to have close obligate aerobe relatives; it is likely that having hydrogenosomes- broken mitochondria- allowed this species to exploit hypoxic and eventually anoxic conditions, at the expense of reduced energy production.
Contrast the alternative scenario- descent from unicellular anaerobic eukaryotes. Those organisms primarily look to forms of fermentation to provide energy from pyruvate- and it would be about the same energy this thing gets from breaking down pyruvate via the reduction of protons in a far more complicated process. Given the evidence, it seems more likely that this organism descends from multicellular aerobic organisms.
These creatures apparently are essentially immobile, attaching firmly to marine sediments. This applies to their aerobic relatives as well, so it seems that lack of motility likely has little to do with their anerobic respiration. A more active organism would probably struggle to survive using hydrogenosomes, however since the hydrogenosome reaction only makes ATP for energy via substrate-level phosphorylation. In aerobic respiration, most of the ATP ultimately produced is from oxidative phosphorylation, where a series of reduction-oxidation reactions are used to create a proton gradient that powers an ATP synthase to make ATP. For all known aerobic eukaryotes, this process uses diatomic oxygen as the final electron acceptor.
There are (single-celled) prokaryotes that use alternatives- nitrates, sulfates, iron ions, etc., but it would appear that this organism has not adopted anything of the sort. That would have required many fundamental changes in its biochemistry, whereas a hydrogenosome seems to be an adaptation from a mitochondrion (and specifically, an adaptation largely by subtraction, where most of the sophisticated electron carriers of a mitochondrion are absent)
The hydrogenosome basically gives this organism a pathway to convert one molecule of pyruvate to acetate and produce 1 molecule of ATP. Combined with the net of 2 ATP from susbtrate-level phosphorylation in glycolysis, that would suggest the creature can make 3 ATP per molecule of glucose. Depending on specifics, aerobic eukaryotes can produce 36-38 ATP per molecule of glucose. So an animal relying on hydrogenosomes instead of mitochondria could very roughly be expected to subsist on about 1/12 the energy for the same amount of food.
My first thought was it it seems totally obvious that atomic clocks would make a superior standard. The comparison is monitoring a controlled ensemble of atoms versus monitoring pulses from a star, light-years away, with proper motion relative to the earth. Atomic clocks are also continuously tuned to provide a consistent signal, and ultimately are dependent on atomic transitions that are governed by fundamental constants, while as the parent notes, pulsars are like motors that gradually spin down over time. However, in the introduction of the paper, the authors do indeed cite over a dozen papers that state that natural astrophysical oscillators are or at least could be the best clocks in the the universe, so the authors do not appear to merely knock down a straw man.
From the paper, it appears at least some of these claims highlight the accuracy of some of these natural oscillators while not taking into account the increased random noise from a stellar source, or the long-term decay of the natural system. It appears that other claims are simply due to the claimants not keeping up with the rapid pace of advancement in atomic clock design, such that whatever super-accurate pulsar or white dwarf an astrophysicist finds is really only as good as the best atomic clocks used to be.
The Wikipedia page for the K-159 submarine includes a picture of how it looked right before its sinking. (The sub in the picture faces the opposite direction as on the sonar image, so it is difficult to get an idea of the damage sustained in the sinking.) While on its final voyage, it was kept afloat with pontoons, which evidently are no longer with the sub. According to this article from 2007, one of the sources for the wiki article, the sub was crumbling at the end of its operational lifetime, and it may have had the hatches open at the time of sinking. So it will be a challenge to raise it. Notably, that Times article discusses a recovery "next summer" from the vantage point of Jan. 2007; it obviously has yet to occur.
The abstract of the Nature Nanotechnology article notes the superconducting transition temperature for the bulk material is around 8 Kelvin, which is definitely liquid helium range (nitrogen boils at 77K). They do go on to note, however, that at very small levels of this molecule, the superconducting gap decays exponentially with the number of linked molecules, and that 4 pairs is the minimum number where any effect at all was seen. So I don't have an exact temperature, but at least liquid helium (boils at 4K), and just as a guess, the minimal four paired molecule version might be something that might only work at the millikelvin range. Those dilution refrigerators are rather bulky items.
Except when complications arise, gonorrhea generally does not get serious enough to actually kill people. It has historically been an aggressive nuisance, but not a great plague even before the discovery of penicillin. Of course, without proper courses of treatment, there would be more complications: there would be occasional cases of gonorrhea developing into heart and brain infections, cases of it causing pelvic inflammatory disease in women, but mostly we'd hear about newborns blinded a few days after birth. It's not just a disease of lust, you know. "Superbug" status aside, we do have plenty of drugs still in the pharmacy that will be able to treat resistant infections. Ceftriaxone and cefixime are third generation cephalosporins; the fourth generation have started seeing service.
One issue is that many of the new and remaining drugs are IV only; from the discovery of penicillin on, gonorrhea has usually been something you filled a prescription and took a pill to treat (of course, in such places where medicine was available). Also, while drug resistance in Neisseria gonorrhoeae is certainly a problem, a concern on the horizon is having its relative Neisseria meningitidis, the causative agent of meningococcal meningitis, develop resistance to cephalosporin antibiotics.
The real issue, in my opinion, with these patents is that Myriad tries to make the information of the gene sequence essential to any detection method for that gene. Take a look at Myriad's patent for the breast cancer-related gene BRCA2. Right at the beginning, "Specifically, the present invention relates to methods and materials used to isolate and detect a human breast cancer predisposing gene (BRCA2), some mutant alleles of which cause susceptibility to cancer, in particular breast cancer. More specifically, the invention relates to germline mutations in the BRCA2 gene and their use in the diagnosis of predisposition to breast cancer." So at first glance, you might think that this patent refers to a diagnostic test for BRCA2, which seems to be an acceptable place for a patent for many people. After all, DNA sequences are just molecules, and there are any number of non-contentious patented tests for biological molecules already- think of glucose test strips, for instance. Manufacturers have found ways to patent various advances in testing for blood glucose without actually asserting a patent on glucose itself.
However, when you test for something like glucose, the test result is going to be a concentration. When you talk about performing a test for BRCA2-based cancer susceptibility, you don't just need to "detect" BRCA2, but be able to isolate it and determine whether it differs from the wild-type BRCA2. So Myriad had the idea that in their patent claims they could define their "methods and materials" to be both the likely molecular bio technique intermediates, and also the molecules that are the theoretical outcomes of any BRCA2 test.
Paraphrasing some of their claims:
-We claim the isolated normal BRCA2 sequence, and any isolated subset of that sequence comprised of at least 15 contiguous nucleotides.
-We claim the isolated major mutant sequence of BRCA2 known to be involved in susceptibility to cancer, and any isolated subset of that sequence comprised of at least 15 contiguous nucleotides.
-We claim nearly 40 different variants of the major mutant sequence.
-We claim any sort of cloning vector, expression vector, recombinant cell line, or PCR primer involving an at least 15 contiguous nucleotide stretch of any of the above sequences.
So Myriad was trying to claim that the invention was a diagnostic method, just that any molecule corresponding to the nucleotide sequences they claimed were an intrinsic part of the "method." What's interesting about the "15 contiguous nucleotides" mention that keeps cropping up is that BRCA2 is over 11000 nucleotides long, producing a protein 3400 amino acids long, such that Myriad laid claim to tiny fragments of the gene which would have had no BRCA2 function on their own.
Yes, normal cells could be expected to have a smaller density of transferrin receptors than cancer cells, but almost all cells could be expected to have some, given the importance of iron ions in cells. The reason transferrin receptors are of such interest is primarily a mechanical issue. Each of your cells is covered with complicated receptors that serve many purposes, and if you're looking for a way for cancer cells to stand out, there are many receptors involved in growth and division whose numbers are typically swollen on cancer cells. The issue is that most of the candidates simply meet messengers at the cell membrane, and pass along the information of the message into the cell via a second messenger. Others like the glucose transporters let cargo through a narrow and specific channel. When transferrin receptors bind to transferrin at the cell surface, however, a vesicle forms around the bound transferrin+receptor complex and pulls the whole thing inside the cell. Once deep inside, the transferrin is induced to let go of its iron ion cargo, and the iron-less complex heads back to the surface.
Given that cells will essentially swallow anything that can be made to bind to a transferrin receptor, this could become an important future route for drug delivery.
However, yes, it is like chemotherapy in that it will affect proliferating healthy cells as well as cancer cells (could be a lot less toxic in terms of metabolic clearance compared to current oncolytics). The protein they cut production on using RNA interference, ribonucleotide reductase, is already targeted by a few chemo drugs in use like gemcitabine. Any cell that needs to make DNA bases needs a working copy of ribonucleotide reductase; rapidly dividing cancer cells just have a much more urgent need. However, this nanoparticle/siRNA system has the advantage of being highly adaptable. Find a new oncogene target? Write a new siRNA to silence it, and you have the equivalent of a whole new class of cancer drug.
The nanoparticles have a component that attaches to the transferrin receptor on the surface of a cancer cell. Transferrin receptors are highly abundant on cancer cells because iron (what transferrin carries) is needed for cell division processes. Coincidentally, this is a fact I learned the first time this story was posted a few days ago.
A few things are going on chemically with hot peppers. Capsaicin is an alkaloid, which is just a term for a nitrogen-containing naturally produced base (caffeine would be another example; something like sodium hydroxide would be a non-alkaloid base). Capsaicin is not a particularly strong base, and is not very water soluble, behaving more like a wax. This is why pure water is not regarded as particularly effective in relieving the pain sensation produced by capsaicin. Peppers as a whole are generally very mildly acidic, with notable quanitities of weak acids like ascorbic acid (vitamin C). However, they are generally not acidic enough to resist spoilage, so preserved forms of chiles usually involve vinegar, which might be the acidity you taste in a hot sauce or canned chile.
Slashdot Mirror
It's not blood that makes red meat red; it's the myoglobin concentration in the muscle, which in turn relates to that muscle's use of oxygen. Meat from adult mammalian tissues on average contains about ten times as much myoglobin as meat from poultry. In poultry, meat can be further differentiated into "light and dark" meat based on what part of the bird it comes from- muscles in the wings, thighs, and legs need more oxygen to sustain activity, have more myoglobin, and are darker- but still have less myoglobin than most beef.
Draining blood out of the meat isn't going to change its color; the myoglobin is within the muscle itself. The color of meat can be affected by the animal's age and diet however: veal, for instance, can be nearly white in color when taken from calves fed only on milk. Myoglobin, like its bloodborne relative hemoglobin, does contain iron, and does represent a major dietary source if you eat red meat.
Want to know what the copyright is really being asserted on? Here's a picture of the back of an Omega Seamaster watch, the article in question. (No affiliation with the site, just what Google turned up first). Omega isn't asserting copyright on their main logo; they've been using it for over a century. Also, it's the Greek letter omega, not exactly a highly stylized and unique design. They aren't asserting copyright on the Seamaster seahorse that dominates the back, though you'd think that desgin qualifies as the best example of artistic authorship on the watch. Omega has been making Seamasters for about 60 years, so I would think that image could still be copyrighted. But that's not what Omega is claiming infringement on either.
The artwork Omega is enforcing a copyright on is that pattern of circles with an omega in it, just to the right of the pronounced Omega logo and above the "825" in the linked picture. That little doodle is about 0.5 centimeters in diameter, and apparently Omega is arguing that when you buy an Omega Seamaster, you are buying an authorized reproduction of that triumph of human artistic endeavor for the agreed-upon price of two thousand dollars. Omega just happens to be so generous as to frame your purchase with a diving watch.
In particular, it mostly illustrates that in flatworms, body plan genes can be routinely reactivated throughout an organism's life. Most multicellular animals on Earth have a series of genes known as Hox or homeobox genes whose role is to determine the correct placement of structures on the body- depending on the form of the organism, "structures" can mean things like organs, limbs, eyes, tails, etc. The activity of these genes is so important that they tend to have been strongly conserved sequences throughout time- we have some Hox genes that are very similar to those in flies, for instance. This conservation is helped along by the fact that the Hox genes ultimately work by signaling other genes to work; the signaling cascade functions whether the signal is for the development of insect wings or for bird wings.
According to the paper, the signaling involved in the development of the posterior end of planaria (Wnt/beta-catenin) had already been identified; the discovery of Smed-prep explains how the development of anterior structures (the trunk and head of the animal) are regulated. In addition, they found that the anterior and posterior pathways normally work in opposition (to avoid growing a tail on the head or head on the tail), and by silencing the posterior signaling, then activating head regeneration, a head would grow at both ends.
From what we know of human Hox genes, the picture is not so simple- even at the most basic level of developmental organization there are several genes that direct development of the head, so there isn't a master gene we can reactivate to grow an ectopic head, but many of the same developmental pathways (Wnt, for instance) are the same or similar across organisms.
That's because, contrary to what the summary says, this is a cosmic ray detector, not a gamma ray detector. The point of the big magnet is that there will be charged particles streaming through that can be steered by a magnetic field (and so identified). Of course, most cosmic rays are protons, but a significant fraction are alpha particles, and one of the major objectives of the experiment is to look for alpha antiparticles (antihelium nuclei, in other words).
Just throwing a question out there: What's holding back the use of high critical-temperature superconductors in applications like the AMS magnet? Helium cooling is a vital, yet difficult and expensive proposition for many high-profile physics projects, to say nothing of innummerable NMR and MRI magnets out there. I realize that as ceramic-type substances, cuprate superconductors aren't as easily drawn into wire as the niobium alloys commonly used, but it seems like those technical challenges are worth dealing with in order to cool with liquid nitrogen rather than liquid helium. Particularly the superfluid helium that was planned for AMS- that stuff abhors a container. Is there some other physical limitation to cuprates that I'm missing, or is it just that the multi-decade nature of the big projects have kept them from adopting newer materials?
I found a nice little illustration of the effect temperature has on the equilibrium of this reaction here. The calculation is actually for the related reaction using carbon (as coke) instead of methane, but the equilibrium constants are about equal for the temperatures discussed here. At atmospheric conditions on Earth, the equilibrium can be considered as shifted completely to the left. Virtually no carbon monoxide is produced from this reaction at temperatures less than about 600K. At a temperature of 956.7K, the levels of carbon and carbon monoxide are equal, and at higher temperatures, carbon monoxide is On GJ 436b, with a temperature of 800K, the equilibrium should still strongly disfavor CO production, and the calculation suggests that there should be around 13.6 times as much carbon (or methane in the case of GJ 436b) as there is carbon monoxide.
However, the researchers determined that "GJ 436b's atmosphere is abundant in CO and deficient in methane (CH4) by a factor of ~7,000." The only way the planet could have gotten an atmosphere like that through this reaction equilibrium alone is if its temperature is really around 2000K instead of 800K. The researchers therefore argue that it's far more likely that some other mechanism is disrupting this equilibrium, like polymerization of methane that pulls it out of the system. In their Nature paper, they include a a chart of the atmospheric ratios of gas giants, both in our solar system and exoplanets; nothing else known has a CH4/CO ratio like that seen for GJ 436b.
We can look at some of the possibilities of what could be happening on GJ 436b:
CH4 + H2O is in equilibrium with CO + 3 H2 (with a change in enthalpy of +206kJ/mol)
Or much eariler, Kurt Vonnegut's Player Piano (1952), where the giant computer EPICAC XIV resided in Carlsbad Caverns. I guess Google's servers won't require an army of workers to swap out vacuum tubes though.
The US participates via a parallel project in The Cancer Genome Atlas administered by the National Institutes of Health, which while remaining independent of the international project, shares data and tailors it's foci to not overlap with those of the ICGC.
It is pitch black. You are likely to have run out of money and had the lights shut off.
It wouldn't be demoted in terms of moving out of its present category. I think the sense is more that the class of dwarf planets, which now comprise only five known objects (Ceres, Pluto, Haumea, Makemake, and Eris) would admit many more members if the minimum radius necessary for the category were revised far downward. The argument then is that the category would be somehow less "special" if there were hundreds or thousands of dwarf planets instead of a handful.
At least from an aesthetic viewpoint, I actually like this proposed new definition though- the size at which an object forms a spherical shape under its own gravity seems like a significant transition. I feel that if an icy sphere the size of Enceladus were discovered out in the Kuiper belt, an assignation of "dwarf planet" would be logical, but such an object would be considered too small under the current IAU definition.
There's a lot of work being done in this area right now- with good reason; there's tremendous potential, and the advance highlighted here is more of an incremental step in a rapidly maturing field than a breakthrough. As the parent notes, Dr. Fiona Wood pioneered a spray-on cell suspension over 15 years ago. She eventually founded a company (now called Avita Medical) which has commercialized this technology. In the last decade, it has been discovered that with minimal modification, an off-the-shelf inkjet printer can print living cells- this article is an example.
The story here from Wake Forest is apparently a successful test of using an inkjet to print directly on wounds using multiple cell types. The group reported these results at the Translational Regenerative Medicine Forum which took place the last few days. Who else happened to be at that forum? Avita Medical, where Dr. Wood still sits on the board.
Apparently, this same guy had a similar project called "Dodgeball" which Google bought out in 2005- and then killed in 2009 to replace with Google Latitude. I don't know how much he got for Dodgeball, but it may be that he really can afford to walk away from offers now. Both Dodgeball and "Foursquare" are/were location-based social networking services for mobile devices- Foursquare appears to tweak the concept by turning it into a sort of Zynga-style game where you earn awards for using the service. 100 million bucks for that.
All right, I may have gone a little overboard with the jargon there. All I was trying to say is that by using hydrogenosomes rather than mitochondria, this organism misses out on a lot of the available chemical energy in its food. In most enviroments on earth, a multicellular organism that tried to live like this would be strongly outcompeted by its oxygen-gulping rivals. However, living attached to anoxic sediments at the seafloor, this organism has little need for mobility, food is abundant from things dying above (the journal article uses the charming term "rain of cadavers"), and anything that competes with it must also cope with the lack of oxygen.
It actually points to the former- a multicellular aerobe adapting to an anoxic niche. The particular evidence is in its use of hydrogenosomes. Hydrogenosomes are believed to be a degenerate form of the aerobic mitochondrion. They have the same double membrane structure, import pyruvate from glycolysis, and include various other components like coenzyme A and ferredoxin. They however lack most of the electron carriers and enzymes of the citric acid cycle and oxidative phosphorylation. The metazoans discovered are known to have close obligate aerobe relatives; it is likely that having hydrogenosomes- broken mitochondria- allowed this species to exploit hypoxic and eventually anoxic conditions, at the expense of reduced energy production.
Contrast the alternative scenario- descent from unicellular anaerobic eukaryotes. Those organisms primarily look to forms of fermentation to provide energy from pyruvate- and it would be about the same energy this thing gets from breaking down pyruvate via the reduction of protons in a far more complicated process. Given the evidence, it seems more likely that this organism descends from multicellular aerobic organisms.
These creatures apparently are essentially immobile, attaching firmly to marine sediments. This applies to their aerobic relatives as well, so it seems that lack of motility likely has little to do with their anerobic respiration. A more active organism would probably struggle to survive using hydrogenosomes, however since the hydrogenosome reaction only makes ATP for energy via substrate-level phosphorylation. In aerobic respiration, most of the ATP ultimately produced is from oxidative phosphorylation, where a series of reduction-oxidation reactions are used to create a proton gradient that powers an ATP synthase to make ATP. For all known aerobic eukaryotes, this process uses diatomic oxygen as the final electron acceptor.
There are (single-celled) prokaryotes that use alternatives- nitrates, sulfates, iron ions, etc., but it would appear that this organism has not adopted anything of the sort. That would have required many fundamental changes in its biochemistry, whereas a hydrogenosome seems to be an adaptation from a mitochondrion (and specifically, an adaptation largely by subtraction, where most of the sophisticated electron carriers of a mitochondrion are absent)
The hydrogenosome basically gives this organism a pathway to convert one molecule of pyruvate to acetate and produce 1 molecule of ATP. Combined with the net of 2 ATP from susbtrate-level phosphorylation in glycolysis, that would suggest the creature can make 3 ATP per molecule of glucose. Depending on specifics, aerobic eukaryotes can produce 36-38 ATP per molecule of glucose. So an animal relying on hydrogenosomes instead of mitochondria could very roughly be expected to subsist on about 1/12 the energy for the same amount of food.
My first thought was it it seems totally obvious that atomic clocks would make a superior standard. The comparison is monitoring a controlled ensemble of atoms versus monitoring pulses from a star, light-years away, with proper motion relative to the earth. Atomic clocks are also continuously tuned to provide a consistent signal, and ultimately are dependent on atomic transitions that are governed by fundamental constants, while as the parent notes, pulsars are like motors that gradually spin down over time. However, in the introduction of the paper, the authors do indeed cite over a dozen papers that state that natural astrophysical oscillators are or at least could be the best clocks in the the universe, so the authors do not appear to merely knock down a straw man.
From the paper, it appears at least some of these claims highlight the accuracy of some of these natural oscillators while not taking into account the increased random noise from a stellar source, or the long-term decay of the natural system. It appears that other claims are simply due to the claimants not keeping up with the rapid pace of advancement in atomic clock design, such that whatever super-accurate pulsar or white dwarf an astrophysicist finds is really only as good as the best atomic clocks used to be.
The Wikipedia page for the K-159 submarine includes a picture of how it looked right before its sinking. (The sub in the picture faces the opposite direction as on the sonar image, so it is difficult to get an idea of the damage sustained in the sinking.) While on its final voyage, it was kept afloat with pontoons, which evidently are no longer with the sub. According to this article from 2007, one of the sources for the wiki article, the sub was crumbling at the end of its operational lifetime, and it may have had the hatches open at the time of sinking. So it will be a challenge to raise it. Notably, that Times article discusses a recovery "next summer" from the vantage point of Jan. 2007; it obviously has yet to occur.
The abstract of the Nature Nanotechnology article notes the superconducting transition temperature for the bulk material is around 8 Kelvin, which is definitely liquid helium range (nitrogen boils at 77K). They do go on to note, however, that at very small levels of this molecule, the superconducting gap decays exponentially with the number of linked molecules, and that 4 pairs is the minimum number where any effect at all was seen. So I don't have an exact temperature, but at least liquid helium (boils at 4K), and just as a guess, the minimal four paired molecule version might be something that might only work at the millikelvin range. Those dilution refrigerators are rather bulky items.
Except when complications arise, gonorrhea generally does not get serious enough to actually kill people. It has historically been an aggressive nuisance, but not a great plague even before the discovery of penicillin. Of course, without proper courses of treatment, there would be more complications: there would be occasional cases of gonorrhea developing into heart and brain infections, cases of it causing pelvic inflammatory disease in women, but mostly we'd hear about newborns blinded a few days after birth. It's not just a disease of lust, you know. "Superbug" status aside, we do have plenty of drugs still in the pharmacy that will be able to treat resistant infections. Ceftriaxone and cefixime are third generation cephalosporins; the fourth generation have started seeing service.
One issue is that many of the new and remaining drugs are IV only; from the discovery of penicillin on, gonorrhea has usually been something you filled a prescription and took a pill to treat (of course, in such places where medicine was available). Also, while drug resistance in Neisseria gonorrhoeae is certainly a problem, a concern on the horizon is having its relative Neisseria meningitidis, the causative agent of meningococcal meningitis, develop resistance to cephalosporin antibiotics.
The real issue, in my opinion, with these patents is that Myriad tries to make the information of the gene sequence essential to any detection method for that gene. Take a look at Myriad's patent for the breast cancer-related gene BRCA2. Right at the beginning, "Specifically, the present invention relates to methods and materials used to isolate and detect a human breast cancer predisposing gene (BRCA2), some mutant alleles of which cause susceptibility to cancer, in particular breast cancer. More specifically, the invention relates to germline mutations in the BRCA2 gene and their use in the diagnosis of predisposition to breast cancer." So at first glance, you might think that this patent refers to a diagnostic test for BRCA2, which seems to be an acceptable place for a patent for many people. After all, DNA sequences are just molecules, and there are any number of non-contentious patented tests for biological molecules already- think of glucose test strips, for instance. Manufacturers have found ways to patent various advances in testing for blood glucose without actually asserting a patent on glucose itself.
However, when you test for something like glucose, the test result is going to be a concentration. When you talk about performing a test for BRCA2-based cancer susceptibility, you don't just need to "detect" BRCA2, but be able to isolate it and determine whether it differs from the wild-type BRCA2. So Myriad had the idea that in their patent claims they could define their "methods and materials" to be both the likely molecular bio technique intermediates, and also the molecules that are the theoretical outcomes of any BRCA2 test.
Paraphrasing some of their claims: -We claim the isolated normal BRCA2 sequence, and any isolated subset of that sequence comprised of at least 15 contiguous nucleotides.
-We claim the isolated major mutant sequence of BRCA2 known to be involved in susceptibility to cancer, and any isolated subset of that sequence comprised of at least 15 contiguous nucleotides.
-We claim nearly 40 different variants of the major mutant sequence.
-We claim any sort of cloning vector, expression vector, recombinant cell line, or PCR primer involving an at least 15 contiguous nucleotide stretch of any of the above sequences.
So Myriad was trying to claim that the invention was a diagnostic method, just that any molecule corresponding to the nucleotide sequences they claimed were an intrinsic part of the "method." What's interesting about the "15 contiguous nucleotides" mention that keeps cropping up is that BRCA2 is over 11000 nucleotides long, producing a protein 3400 amino acids long, such that Myriad laid claim to tiny fragments of the gene which would have had no BRCA2 function on their own.
Yes, normal cells could be expected to have a smaller density of transferrin receptors than cancer cells, but almost all cells could be expected to have some, given the importance of iron ions in cells. The reason transferrin receptors are of such interest is primarily a mechanical issue. Each of your cells is covered with complicated receptors that serve many purposes, and if you're looking for a way for cancer cells to stand out, there are many receptors involved in growth and division whose numbers are typically swollen on cancer cells. The issue is that most of the candidates simply meet messengers at the cell membrane, and pass along the information of the message into the cell via a second messenger. Others like the glucose transporters let cargo through a narrow and specific channel. When transferrin receptors bind to transferrin at the cell surface, however, a vesicle forms around the bound transferrin+receptor complex and pulls the whole thing inside the cell. Once deep inside, the transferrin is induced to let go of its iron ion cargo, and the iron-less complex heads back to the surface. Given that cells will essentially swallow anything that can be made to bind to a transferrin receptor, this could become an important future route for drug delivery.
However, yes, it is like chemotherapy in that it will affect proliferating healthy cells as well as cancer cells (could be a lot less toxic in terms of metabolic clearance compared to current oncolytics). The protein they cut production on using RNA interference, ribonucleotide reductase, is already targeted by a few chemo drugs in use like gemcitabine. Any cell that needs to make DNA bases needs a working copy of ribonucleotide reductase; rapidly dividing cancer cells just have a much more urgent need. However, this nanoparticle/siRNA system has the advantage of being highly adaptable. Find a new oncogene target? Write a new siRNA to silence it, and you have the equivalent of a whole new class of cancer drug.
The nanoparticles have a component that attaches to the transferrin receptor on the surface of a cancer cell. Transferrin receptors are highly abundant on cancer cells because iron (what transferrin carries) is needed for cell division processes. Coincidentally, this is a fact I learned the first time this story was posted a few days ago.
A few things are going on chemically with hot peppers. Capsaicin is an alkaloid, which is just a term for a nitrogen-containing naturally produced base (caffeine would be another example; something like sodium hydroxide would be a non-alkaloid base). Capsaicin is not a particularly strong base, and is not very water soluble, behaving more like a wax. This is why pure water is not regarded as particularly effective in relieving the pain sensation produced by capsaicin. Peppers as a whole are generally very mildly acidic, with notable quanitities of weak acids like ascorbic acid (vitamin C). However, they are generally not acidic enough to resist spoilage, so preserved forms of chiles usually involve vinegar, which might be the acidity you taste in a hot sauce or canned chile.