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CharonY

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Everything posted by CharonY

  1. CharonY

    Zombie Plan

    Still depends on how transmissible the zombie-agent is. Zombiefying the ocean might be a bad idea. Also a question might be, how long they have to burn to become "inactivated". Normally you die from suffocation rather than burns, I guess. But how about zombies? Also, if it is human specific, can't we train all meat eaters in our local zoo to hunt them down? Of course it may cause other problems later on, but one thing at a time. I shall start by training colibris.
  2. Especially if the info is wrong. Or at least it is given here in the wrong context. As you mention Propecia, which acts on male baldness, I have to assume that you are talking about male baldness. FSH only stimulates estrogen production in ovaries. In males FSH acts on Sertoli cells. While it is known that it is involved in second messenger pathways their precise role in spermatogenesis was still unknown (at least when I was an undergrad, things may have changed a lot). Secondly male pattern baldness cannot be protected against by high estrogen levels. Of the androgens DHT has been identified as to be detrimental for the follicels and Propecia acts by blocking a reductase that converts testosterone to DHT. Not by blocking testosterone or any androgen itself. The basis for males is therefore (AFAIK) overexpression of the ype II 5alpha-reductase, coupled with a highe sensitivity of the follicles against DHT. Again, Mokele was correct, at least with respect to males. In females I recall that baldness might occur due to an imbalance of androgen/estrogen ration. In that case FSH might play some kind of role.
  3. No, these are elements of classic ethology. It would help if you gave a little more information about what precisely you would like to know more. I have to admit that have not been dealing with it since my undergrad times (simply because I found out that in that field there was hardly any funding ), so what I remember might (or is likely) to be out of date. Though it appears to me that you are interested mainly in the basics. Just to add, ethology is of course related to neurobiological aspects. When I studied there was a big effort to find correlation between behaviour (patterns) and neurobiological activity and changes. There was some progress in a group using song learning in zebra finches as a model (was a fun time, btw. catching zebra finches that escaped the cages, or simply had no intention of singing when being watched...), but funding at that time kindof dried up. Also, imprinting and conditioning are forms of learning that work differently though (and are effective under different conditions), whereas fixed action patterns (FAP) are a behavioral sequence that may or may not be triggered by learned cues. Traditionally it was believed that FAPs are completely innate, however I faintly recall that while the pattern itself may be rigid, the trigger might in some cases be modified. Other argued that it would not be a FAP at all in that case.
  4. There is of course more to that. What is considered as beauty will be overlaid with a lot of cultural background, however there are some things that work universally. However, "hardwired" is the critical part here. If we only consider a genetic basis then you need at least two components: -first: genes that result in something that we describe as beautiful -second: genes that make us feel attracted to those carrying the first set of genes, so that we perceive them as beuatiful You will have noticed that while a number of things associated with beauty can be objectively measured like symmetry etc, the concept of beauty in general is also down to perception.
  5. This will only be visible on plate. And these typically "clumped" colonies are fairly easy to spot.
  6. Dotsie, thank you for the clarification. See, what you said makes a whole world of difference beacause you ask whether the cultures in question are currently performing aerobic respiration. Now the tricky part here is that a part of the culture could do it, whereas the others don't. This is especially likely in larger volumes. The thing is how sensitive the test needs to be. It depends on the the composition of your medium, though. I will assume that you used glucose as C-source, in this case you could simply add a pH indicator to monitor acidification due to fermentation. Depending on the overall media composition, though, even aerobic respiration might shift the pH somewhat, so for larger and older cultures this is a bit tricky. If you use a more sensitive method (as RT-PCR) you will generally find that in very old and thick cultures and very there is almost always a portion of the population either switching to anaerobic metabolism, or at least express mRNA generally associated with oxygen limitation. Even in absence of fermentation products.
  7. Interests are overrated anyway.
  8. All I see is an incoherent rant. Does anyone mind if I remove it?
  9. Actually you would benefit most from lectures, if you read beforehand and only use the info in the lecture to fill up anything you did not understand. It is hard to concentrate throughout the whole lecture, write up everything relevant and at the same time invest enough brainpower to not only memorize but understand what is being said.
  10. CharonY

    Zombie Plan

    And that it is not transmissible by fish.
  11. This does not invalidate medicine as one of the adaptive mechanisms per se. For one Darwin himself did not reject the possibility of Lamarckian inheritance (that came later with neo-darwinism and then modern synthesis), but even so it would at best be a historical distinction. Now one could argue that the modern synthesis assumes a genetic basis for evolution, however, as others already mentioned, the ability to relay information across generations does ultimately has a genetic basis. Medicine would only be a sub-part of it.
  12. Heh, I could think of half a dozen ones. Though the question is do you want to know whether it can survive oxygen, or whether it requires oxygen?
  13. It depends what is recognized as the epitope. Even then it depends on the amount of conformational changes upon binding to it. If you want to make a very precise quantitation, one should use (monoklonal) antibodies directed against an epitope not undergoing conformational changes upon ligand binding, of course. If your goal is just to see whether there is am up-regulation, it may mot be an issue, as with more receptors you would also see more signal. There might be a competition with the ligands, however, so this would only be a qualitative analysis. But again, it really depends where the epitope is. If it is not in the pocket it should work reasonably well (depending on the precision you require).
  14. CharonY

    Zombie Plan

    I think I should start breeding super flesh eating flies then. Anyone who is going to whack zombies with melee weapons: you are aware how bloody tiring swinging such a thing is? For the (very) untrained like me mere 10 minutes (or less) of kendo is sufficient let one drown in ones own sweat. And that is one-on-one and not one-on-horde.
  15. Maybe it correlates (negatively) with the intelligence of the woman? I recall a study in which it was found that females might find more masucline faces more (sexually) attractive, but slightly femalized faces were considered more trustworthy and were more desirable as partners. This does not really translate into bad vs nice boys, though.
  16. Well there are other modes of horizontal gene transfer, including transduction via phages or natural transformation (though Eschericia and Enterococcusspecies are unable to that).
  17. CharonY

    Life?

    Plants and in fact all cells react to a host of stimuli. Both external and internal. Only because they do not run around does not mean that they do not sense and react to stimuli.
  18. This is an oversimplification. What is [math]\Delta[/math]H in this case?
  19. CharonY

    Life?

    Heh, it has been mentioned countless times now, that formal definitions of life do not exist. But regarding viruses, if one thinks of them as living organisms, so can be our individual genes. See, they also reproduce and proliferate, albeit with the help of other genes and their respective gene products, not unlike viruses. So is the complete unit "life" or already sub-parts? Again, this is a question that is not possible to answer easily, as there is not a simple property of life vs. non-life. Rather this distinction was historically done instinctively (bird alive, rock not alive) and then a definition was made from the bottom up. Mind you, there are a number of consensus definitions, but they are basically based on a priori distinction.
  20. Deinococcus radiodurans is radiation resistant, but it does not generate energy. The names of the fungi are given in iNows post (as is the link to the publication itself). Not to rain onto the parade, however the study only shows that the fungi grew faster if irradiated. They still require all the other nutrients. How the works and whether it is really feeding on the radiation or a more obscure secondary effect, is still unknown. Regarding the bacteria, those mentioned in the OP do not (as already mentioned) directly utilize radiation, however there are bacteria that breathe metals, including uranium, instead of oxygen, for instance (a process termed dissimilatory metal reduction, btw). Well it sure isn't. At least not if you look at bacteria. They have a lot of different means of energy metabolism, of which the above mentioned metal reduction was likely one of the earliest forms of energy generation. In theory this energy could also be utilized for carbon fixation, though few bacteria nowadays actually do that (most likely as photosynthesis is more effective in that regard). However the first bacteria were strict anaerobes so the food chain in that time could not start with photosynthesis. Edit: kind of cross-posted with iNow
  21. CharonY

    Life?

    Simple and for the same reason plasmids are not considered alive. It does not have a metabolism. Truth is, however, that "alive "is not really a physical property itself, but rather a collection of properties. Simply put: there is no clear-cut demarcation between alive and not-alive. As with many biological aspects everything exists in continua (to put it simply).
  22. Bloody hell. Missed it. Now there is a second that I will never see again. Oh wait, here is another one...
  23. Well, apparently economists disagree. One aspect often uttered was that the New Deal enhanced unemployment by raging wages. But according to Krugman: And to my simple and rudimentary understanding this makes a lot of sense.
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