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Everything posted by GDG
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Only if you ignore Relativity. You're trying to set up a universal preferred reference frame: Relativity proves that you cannot.
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From the reference frame of the stuff falling in, everything just falls straight into the BH. The earlier matter cannot exert any back pressure on the later matter.
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Yes, viruses can swap genes. If you have a host cell that is infected with two different viruses, you can have "crossing over" of the viral genes (especially if the viruses already have similar genes), resulting in new viruses that have an assortment of genes from each of the "parent" viruses. This is actually what happens each year with the flu virus, and why your flu shot from last year won't help you this year. We classify flu viruses (at least the type A viruses) based on which of several "H" (hemagluttinin) and "N" (neuraminidase) antigens they display. Thus, you see reports of the current swine flu being "H1N1", which means type 1 hemagluttinin and type 1 neuraminidase, or the bird flu being H5N1. Flu (in general) infects humans, birds, and pigs: farming practices in which pigs and poultry are raised together are thought to provide a reservoir of virus and contribute to the reassortment of flu antigens.
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The main obstacle is getting the gene transfer to work. It is difficult to get the genes taken up by the appropriate cells, difficult to get it integrated, difficult to get the cell to express the genes appropriately, and difficult to prevent the cells from essentially spitting out their medicine (OK, they somehow disable the inserted genes). Typically, the introduced genes are expressed for, at most, a few weeks. This might be enough for treating an acute infection. But on the other hand, gene therapy has had a few catastrophic (and fatal) failures.
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Modern Day Selection Pressures.
GDG replied to Psycho's topic in Evolution, Morphology and Exobiology
Although heavily outnumbered by brown eyes, as long as blue eyes are considered attractive to some, they will probably remain in the gene pool After all, attracting a mate is one of the clearest selection pressures. -
First problem: creationism is not a theory (nor is "intelligent design"). In some respects, both creationism and ID are "anti-theories", because they cannot be used to make any useful prediction, and cannot be falsified by an experiment. The theory of the origin of life is generally called "abiogenesis" -- you may want to start with that. As for unifying it with the laws of physics, I'm not sure I see the problem. Any scientific theory will of necessity comport with the laws of physics. As a practical matter, however, you may want to start with those branches of "applied physics" known as chemistry and biology.
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NEOCORTEX and CEREBRAL CORTEX WHat do they actually do?
GDG replied to Kylon's topic in Anatomy, Physiology and Neuroscience
On the other hand, you find savants like Kim Peek, who have no corpus callosum at all... Interestingly, some research has shown that a number of brain areas have inhibitory functions, and that if you inhibit the inhibitors in a subject (e.g., using fMRI), the subject can exhibit savant-like behavior, like instant calculation or perfect pitch. As if we're driving around with one foot on the accelerator, and the other foot on the brake all the time... -
How would you define the concept of "passing" without talking about time? It seems to me that you have only two choices: (a) you describe "before" and "after" positions, but "before" and "after" inherently require the passage of time; or (b) you talk about one having a greater velocity than the other, but again velocity inherently depends on distance traveled per unit of time. Time as a dimension exists. Units of time (minutes, seconds) are arbitrary.
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Probably the easiest way to do that would be using iRNA. You would insert genes (by gene therapy, a technology still under development) that would express short RNA strands that interfere (hence "iRNA") with the viral RNA transcripts. Basically, the iRNA hybridizes to the target RNA and makes a double strand: an enyzme in the cytoplasm ("dicer") recognizes double-stranded RNA and chops it up. It is conceivable that one could insert genes that make antiviral proteins (or even chemicals), but this would probably be more difficult. As for soap, it solubilizes bacteria and viruses, and can denature their proteins and lipid membranes. Your skin isn't harmed because the outer layer is already dead.
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NEOCORTEX and CEREBRAL CORTEX WHat do they actually do?
GDG replied to Kylon's topic in Anatomy, Physiology and Neuroscience
No need for drugs. The most effective way to enhance your neocortex is to exercise it. Learn lots, from a variety of different subjects. Learn a musical instrument, and practice it (or them) regularly. Exercise, especially in activities that require more thought and coordination (less running, more dancing). It wouldn't help to have more neurons if they weren't connected up and used. Simply growing more cortex would be like adding another gigabyte of memory to a computer that only runs MS-DOS: there, but not useful for anything. Doesn't sound like the girls I grew up with -
slowing down virus reproduction
GDG replied to cameron marical's topic in Biochemistry and Molecular Biology
The tactics that your immune system use include: shutting down protein production (this is one of the functions of interferon); and killing off infected cells (this is what cytotoxic T cells do) Approaches used by drug companies include: inhibiting the activity of any viral protein, thus interfering with its life cycle; blocking virus entry into host cells: if the virus cannot get inside, it cannot replicate -
The tree could be monoecious, having both male and female flowers on the same tree.
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Does he carry a lot of radiation shielding? It seems to me that there are a couple of things that might screw up your results: First, if you were to jack the car up so that none of the tires were touching the ground, the tires would still register a pressure. So what are you measuring? The air is compressed before you start: you have an initial pressure before you load the tires with the car's weight. Perhaps if you subtract the "unloaded" pressure from the pressure you read, your answer may be closer. The second thing, which is probably minor, is that the tire sidewalls have some degree of stiffness, and probably account for a fraction of the support.
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The Dangers of Staphylococcus Epidermidis
GDG replied to Green Xenon's topic in Microbiology and Immunology
Strangely, this bacterium is one of the most common species found on human skin, and normally does not cause disease. -
Earth's Rotational Axis as Related to the Sun
GDG replied to SwampeastMike's topic in Astronomy and Cosmology
No, most of those lines will only be parallel to a tangent. A "tangent" to a circle must contact the circle at one (and only one) point. Uranus is the only planet for which this is possible. -
It would be more accurate to say that the most distant stars are used to estimate the age of the universe. If the most distant star is (for example) 90 billion light years away, then we know that the universe is at least 90 billion years old. And since the light from the star that we observed took 90 billion years to get here, that should make it one of the oldest as well.
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I've burried a couple... Sure there is: it's called "chaos theory"
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slowing down virus reproduction
GDG replied to cameron marical's topic in Biochemistry and Molecular Biology
Slowing down viral reproduction generally helps, but does not guarantee a cure. There are some pathogens that replicate very slowly, and evade the immune system by other means. TB, for example (not a virus, but bear with me), reproduces very slowly (it can take weeks to culture the bacterium), but has a thick mucopolysaccharide coat that protects it from the host's immune system. Other pathogens secrete proteins that turn off immune responses directly. -
Planet sailing through the cosmos very fast?
GDG replied to Baby Astronaut's topic in Astronomy and Cosmology
Planets can be ejected from a solar system by gravitational interaction with other planets or a passing star. The galaxy does have gravity. Whether your passing planet kept its original velocity or not would depend to some extent on whether is was headed in or out. If headed toward the galactic center, it might even be accelerating. Actual planetary collision is probably not as likely as a gravitational pas de deux, resulting in the planet in a new orbit (or possibly ejected from the system). However, there are plenty of craters in our system that attest to the fact that astronomical collisons do occur. -
It doesn't have to collapse asymmetrically: the star is already spinning. As the radius decreases, the rotation rate has to increase. Like a spinning ballet dancer, who speeds up as she brings her arms in close. For another example, find one of those playground merry-go-rounds, Grab on, and run it around until you have it moving pretty well, then jump on, staying out at the rim. Notice the rotation rate. Now climb toward the center of the merry-go-round: you'll notice that the rotation rate speeds up quite a bit. If you get several people to copy you, you can really accelerate the rotation rate -- to a nauseating degree
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Just to forestall confusion, there is a second recognition system that is employed in the ribosomes. Proteins that bind directly to DNA or RNA work as described. In the ribosome, the process of translating mRNA codons into the correct amino acids is basically due to transfer RNA ("tRNA") molecules. tRNA molecules have an "anti-codon" that hybridizes to the codon that is being read. There is a separate tRNA for each anticodon (although some of the anticodons accomodate "wobble", and can bind to several different codons): thus, you have less than the theoretical maximum number of tRNAs. The correct amino acid is attached to each tRNA before it goes to the ribosome, by an enzyme known as an aminoacyl-tRNA synthetase. This enzyme binds an amino acid, recognizes the anticodon on the tRNA, and binds the amino acid to the tRNA. You have one aminoacyl-tRNA synthetase enzyme for each different amino acid. The ribosome (which is a big complex of proteins and ribonuclear RNA (rRNA) takes care of finding the appropriate spot on the mRNA to start translating, matching up the tRNAs to the codons, taking the tRNA's amino acid and attaching it to the end of the growing protein chain, ejecting the "empty" tRNA, and moving down to the next codon. There's a decent animation at .
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The radio-frequency photons do not have enough energy to disrupt a H-O bond (ionizing the water).
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You set up the webcam; I'll get the stopwatch