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LucidDreamer

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Posts posted by LucidDreamer

  1. I think you are making too much of the brainwave data collected from eeg machines. They do not measure anything near specific enough that you could identify somebody from them. The eegs only collect very general information about brain activity. It is an interesting thought though. Maybe sound waves can be made that have alpha patterns in them to see if it will induce coma patients to wake up.

  2. Which are the few cells programmed to die i.e. how are they chosen?

    I didn't mean it in the sense that some cells were preordained to die while others weren’t. I meant that some cells will experience problems, such as viruses, environmental damage, or problems in replication, that will cause them to commit suicide for the greater good of the colony. Or, as Zyncod pointed out, some neurons must die so that the brain can be wired for efficiency and specificity to the organism’s environment.

     

    However, some kinds of cells do experience cell death more than others. Some cells don't suicide themselves unless they experience a certain trigger event (certain cells of the immune system) or environmental damage (neurons). Some cells go through mitosis frequently and die after a certain number of reproductions (epithelia cells). Some cells kill themselves early during development. Whether or not cells experience programmed cell death ultimately is determined from what kinds of cells they have become. Skin cells have a different life expectancy than liver cells. How they became liver cells or skin cells was determined by differentiation events. So whether a cell is likely to commit programmed cell death any time soon is determined first by what kind of cell it is, second by what stage of development the organism is in, and third by random environmental events (such as a virus infection).

  3. I´m not a native english speaker so correct me if I´m wrong: Isn´t he saying that all actions taken were according to the law instead of saying that everything they do was ok because it´s for a "good cause"? My reading of the passage you provided is the former while your comment on it seems to imply the latter.

    It can be interpreted either way. I'm hoping, for all our sakes, that he meant it in your interpretation.

  4. Programmed cell death is a reaction to environmental damage and the natural degradation of macro-molecules. Programmed cell death and a limited life span are the ways that life deals with environmental damage, degradation, and mutation. Without these things our existence would not be possible. Without them our earth would still host millions of immortal simple macro-molecules (assuming that abiogenises on earth is correct). Degradation of macromolecules is a natural occurrence that is related to entropy. Mutation is a necessary evil. An imperfect means of information storage and replication is the method that life deals with its hostile and changing environment and evolves into a more efficient and capable form, but with it comes the price of disease. Programmed cell death is a sacrifice of the few to ensure the survival and reproduction of the many. Without programmed cell death our bodies would be constantly plagued by disease, such as cancer, and unable to survive until we reproduce.

     

    Check out these wikis: http://en.wikipedia.org/wiki/Programmed_cell_death

    http://en.wikipedia.org/wiki/Apoptosis

  5. What's your point? So there are some extreeme examples where poeple have vitamin C deficiency' date=' no one here is denying it exists. But the fact remains that a typical human diet contains more than adequate vitamin C, which is why we no long need to have the ability to produce it.

    [/quote']

    What's a typical human diet? The American diet? The French diet? The English diet? The Greek diet? The South American diet? The African diet? Or one of the diets of one of their subcultures or one of their individuals? Who is talking extreme examples? If you were to remove all of the food enrichment (adding of vitamins to our food) then more than half of America would be deficient in one vitamin or another, such as vitamin c (don't know exact numbers on this). Many groups of people have lived off animals or just one kind of crop, like corn or rice over the centuries and thousands of years before it.

    Seeing as how poeple in poorer nations are more likley to starve to death it's beneficial for their bodies to not waste energy in producing a vitamin they're getting enough of for the most part. Are you trying to dispute this? Would you suggest giving starving people vitamins instead of food? Which as I last recall contains vitamins.

    It's called regulation. Our bodies make chemicals, such as vitamins, when we need more of them and stop producing them when we don't. If I am not mistaken, the genes in other mammals that produce vitamin c work this way. If those starving people were already getting enough vitamin c, then their bodies wouldn't waste energy producing it. I don't believe that loosing the ability to produce vitamin c was beneficial in the long run. I just think there was a period in time when our ancestor’s population was small and there were plentiful amounts of vitamin c in their diet. I believe they lived in the jungle at the time and had their fill of vitamin c rich foods. I don't believe that vitamin c was so plentiful after they moved out into the savanna, or when they starting living off of wild meat and following herds. There is not very much vitamin c in meat and some groups of people have lived almost exclusively off of meat.

     

    Answer this question: Do you believe that Homo sapiens would have been better off or worse off with a gene that produces vitamin c when it is absent and stops making it or makes small quantities when it is present in the diet? Think of all the different situations he has been in and diets that man has had over the thousands of years of his existence.

     

     

    Well maybe you shouldn't be assuming that. That's not an arguement. From what I've read and I have read research on this. There are far more respectible studies debunking the use of vitamins than there are supporting it. Any search on the internet will find this information. Actually the only solid research on vitamins shows that excess of many vitamins especially the fat soluble ones can be very detrimental to your health.

     

    If you do a quick search on the net you'll find that info on vitamins just a big pot of conflicting information. Except for the dangers of over consumptions which are very clear.

     

    Like why not just eat a balanced diet and get all you need from that' date=' Instead of eating crap trying to compensate for it with vitamins which may or may not help and accept the risks that come from that?[/quote']

    Well, if you look at what I said, I only mentioned talking a single multi-vitamin. I have seen the research on taking mega-doses as well and I agree it will probably do more harm than good. The majority of sources that I have researched recommend taking a single multi-vitamin. It's not always so easy to consume large amount of fruits, vegetables, and other healthy whole foods everyday. A multi-vitamin only has small amounts of vitamins that act as an insurance policy against deficiencies and are not likely to harm you and probably do more good than harm for the majority of people. People should eat more spinach and strawberries but they don't, and they would be better off taking a vitamin if they won't give up their McDonalds.

  6. Look vitamins exist for a reason. They're chemicals that we've lost the ability to produce due to their abundant supply in our diet. We don't need to produce them because we get enough as is.

     

    There are many places in the world where people are not as rich and well-fed as the western world. For most of the history of mankind man was not as well-fed as he is today. Additionally, mankind has not lived in the jungle where food with vitamin c was much more plentiful then in the forests, plains, and savannas. Our ancestors that lost the ability to produce vitamin c may have had a plentiful supply, but we know of at least some examples of their descendants that would have benefited from the ability to produce it.

    Sure maybe if you're stupid enought to try to survive off of kraft dinner alone eating a multi-vitamin might help you. But for a person that eats a varied diet all vitamins do is give you expensive pee.

     

    Really they give nutritionists more to talk about, but for someone who doesn't eat a stupid diet or has some underlying problem extra vitamins serve no purpose.

     

    Most nutritionists recommend taking a multi-vitamin a day, which, I'm assuming, is based on research.

  7. One of the main problems with explaining emotions scientifically is that it requires knowledge that we don't have. In order to fully understand how emotions work, we would have to understand how the brain works. However, there is still a great deal that we do know, so here are some links:

    http://en.wikipedia.org/wiki/Affective_neuroscience

    http://www.news.wisc.edu/packages/emotion/

    http://www.hss.bond.edu.au/psyc12-214/lectures/week10notes.htm

  8. Smoking can cause various problems. It's possible that is might cause ED, but it is more likely that it won't. As you probably know, smoking can cause a lot of serious problems other than ED. If you are worried about getting ED or other problems from smoking but you can't give it up, then you should concentrate on other healthy habits. You should exercise regularly, eat right, and reduce stress as much as possible. Somebody that does those things but still smokes a few cigarettes a day would be doing ok.

  9. i heard the rate of mutation in some strains of HIV is decreasing. but since drug use increases the level of mutant strains of HIV why is this happening???

    The terminology gets a little confusing when we use the words rate of mutation. DNA mutation rate in the same environment is constant, but the variables in the environment are numerous (including the method of replication). The anti-HIV drugs actually reduce the amount of overall mutations in the population because there are fewer viruses to mutate. If we are determining the rate of mutation of a virus by how many different forms or clades that we observe in a population over a period of time, then we would conclude that the rate of mutation of HIV has decreased after the introduction of the drugs. But if we were to study the rate of mutation by factoring in the total amount of virus, then the mutational rate would be the same. Drugs don't increase the mutational rate; they only provide a selection process that leads to a form of virus that is more resistant to drugs. At the same time, with the cocktail there is very little chance that a virus will be able to mutate into a viable form because it will have to triple mutate.

  10. The average number of connections in the human brain does not exceed the amount of atoms in the universe. If we assume that each connection is made of a dendrite/axon connection, then each connection requires many atoms. Therefore, if each connection requires many atoms, it is impossible that the connections could exceed the number of atoms in the universe.

     

    Furthermore, the amount of potential connections could not exceed the amount of atoms in the universe. If each connection requires at least two atoms (they really require more) then the amount of connections in the brain could not possibly be more than 1/2 the amount of atoms in the universe. Obviously the brain could not have anywhere near this amount of connections because a human skull could not contain half the mass of the universe.

     

    I'm guessing that when people use the term "potential connections" they are referring to the amount of possible different connections that could be made. If there are 10^11 neurons and each one can make 100 connections then the total possible number of different connections is 10^13 times 10^13, which is only 10^26 and much smaller than the estimated 10^80 or so atoms in the universe. Note that I don't know the average number of connections that each neuron makes, but it would have to be a very large number for the amount of possible connections to equal the amount of atoms in the universe.

  11. "Nitric oxide acts as a slow-down and search signal in developing neurites.

     

    Nitric oxide (NO) has been demonstrated to act as a signaling molecule during neuronal development, but its precise function is unclear. Here we investigate whether NO might function at the neuronal growth cone to affect growth cone motility. We have previously demonstrated that growth cones of identified neurons from the snail Helisoma trivolvis show a rapid and transient increase in filopodial length in response to NO, which was regulated by soluble guanylyl cyclase (sGC) [s. Van Wagenen and V. Rehder (1999) J. Neurobiol., 39, 168-185]. Because in vivo studies have demonstrated that growth cones have longer filopodia and advance more slowly in regions where pathfinding decisions are being made, this study aimed to establish whether NO could function as a combined 'slow-down and search signal' for growth cones by decreasing neurite outgrowth. In the presence of the NO donor NOC-7, neurites of B5 neurons showed a concentration-dependent effect on neurite outgrowth, ranging from slowing at low, stopping at intermediate and collapsing at high concentrations. The effects of the NO donor were mimicked by directly activating sGC with YC-1, or by increasing its product with 8-bromo-cGMP. In addition, blocking sGC in the presence of NO with NS2028 blocked the effect of NO, suggesting that NO affected outgrowth via sGC. Ca2+ imaging of growth cones with Fura-2 indicated that [Ca2+]i increased transiently in the presence of NOC-7. These results support the hypothesis that NO can function as a potent slow/stop signal for developing neurites. When coupled with transient filopodia elongation, this phenomenon emulates growth cone searching behavior."

     

    http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15009128&query_hl=1

  12. from his OP, i thought he was refering to wether or not spacetime had quanta. i often here people saying that plank lenth/time might be the quanta since gravity gets very strong at that short range and length/time don't always make sense.

    That would mean that spacetime exists as a grid, like a checkerboard, correct? What would be between the squares? Or if there is no "space" between the squares, why is it quantized?

  13. Does everything in the universe affect every other thing in the universe? If a butterfly flaps its wings in South America, will something across the universe feel that effect in some small way, directly or indirectly, no matter how long it might take? Electromagnetic radiation and the force of gravity will travel in all directions forever until they react with something. That something will feel the effects of that reaction, will change in some small way, and will in turn send out its own electromagnetic radiation and gravity. Is my typing right now creating a chain of events that will eventually be felt on the other side of the universe? Is you mouse click going to be eventually felt by every other thing in the universe?

  14. Only if you use enzymes compatible with double stranded DNA. Who is to say that extraterristrial life could form a ligase to replicate 3 or 4 or n [/i']strands of DNA?

    I wouldn't say that it would be impossible, but I believe that it might be improbable. I admittedly don't know a great deal about 4 stranded DNA, but from what I know about double stranded DNA I don't think that a 4 stranded DNA molecule would be very stable. Since we assume that chemistry on other planets will work similar to our own I think a 4 stranded molecule would not be useful and therefore it would be not selected during evolution.

  15. You could try reading some of Carl Sagan's books. Most of his books are interesting and easy to understand. His books are not really up to date though, but since he didn't present a lot of cutting edge material I think it should still be ok.

     

    Also, you could ask for a telescope for Christmas or your birthday :)

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