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CharonY

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Everything posted by CharonY

  1. OK, so how do you prevent that? The news (especially, but not limited to the US) are more interested in narratives than in facts. So you (as a scientists) tell them something, carefully pointing out the caveats and they blow it out of proportion, or misinterpret it. You call them and say what they did was wrong and they shrug and tell you that it is old news anyway. Another thing is that very few media are interested in properly reporting science news to begin with. Of course one could preach that scientists should do more outreach (on top of the extremely busy schedule I should add), but on what platform? Blog it, with the hope that a few students may end up reading it?
  2. If you mean whether there have been measurement of thermodynamic stability of wobble base pairs, then the answer is yes. The physical forces involved are essentially the same as for normal base pairing though the resulting geometries are slightly different.
  3. The hypothesis was formulated in the 60s. Since then wobble base pairing has become an often observed and known phenomenon.
  4. And also, when humans are involved often rigorous controlled environments are neither feasible nor desirable. In these cases even studies with thousands of subjects can see associations that are spurious or miss important clues because the sample composition obscures it. One will hardly find simple yes or no answers, but only mounting evidence for the one or the other. Over time. The WHO's job is to give recommendations based on the data that is currently available. If new data suggests adverse effects it would be foolish to ignore it. Yet they generally give rather cautious advise. The media is complete other thing, though.
  5. More precisely, they have an additional regulatory mechanism, triggering contact inhibition.
  6. Depends on what you want to talk about. Most of the time I use Powerpoint with a tablet notebook so that I can scribble when there is need (I tend to hand write formulas). It really depends on the topic, and audience, though.
  7. How do you determine the pH of a dried substance?
  8. This is kind of off topic, but this is actually quite an interesting point. The problem is, of course that without extensive studies it is hard to figure out if a treatment really cures cancer, or whether it was just an isolated event in the lab. Of course patients with terminal cancer are prime candidates for the early rounds for clinicals as in principle they can only benefit from it. In addition, the routine timeline for clinical trials is around 6-8 years. So 50 years would probably include the discovery of a substance with yet unknown function. In fact I heard of examples of the identification of proteins that were identified around 40 years ago and are now undergoing phase II trials...
  9. And for those that do not- welcome to the club
  10. I think you are confusing who wants what. The companies are not per se interested in creating certain behaviors with their drugs. This is between the doctor and the patient to decide. They do provide pharmaceuticals that have demonstrated to influence conditions/diseases/whatever in a certain way that patients/doctors may find to be an improvement compared to their current condition. What precisely the drug causes is what clinical trials are for. In the given test population the reactions are monitored and communicated to the FDA who will then approve (or not) whether the given medication will be useful in treating a given condition (that is the short of it, anyway). One should also note that no medication works precisely in a given way. Organisms are terribly complicated systems and there can and will be several effects associated with any given medication. The trials are there to find out what, on average they may be. However individual differences can lead to unforeseeable results. Medicine is not deterministic and it cannot guarantee precisely the desired result. However, any medication has to be shown that in most cases improvements will be seen. In future there is the vision for individualized therapies in which omics data will be used to assess, for each person, whether any given medication may or may not be effective. But this is just a vision right now. But to answer the initial question: I cannot see how providing medication does, in any way interfere with patient's rights. Of course a doctor can misinform a patient, maybe even due to incitement by pharma companies, but that is a different matter altogether.
  11. Let's blindfold the communicator, mix up the letters on the touchscreen and try again.
  12. That is what I get roughly, too. Show the calculations. Also did you consider that you only used a part of each dilution (i.e. that your sample is even more diluted by a factor)?
  13. Very, actually. Just two pointers Salmonella as mentioned above and Clostridium. Read up on both.
  14. Well, I have grown plants on nutrient medium with agar. The agar plates are whitish translucent and you can see the plant pretty well in it. The plants probably do not really benefit from the agar itself, but it allows you to solidify the nutrient solution.
  15. Actually I would not necessarily call them equations, precisely as it conjures mathematical equations, but rather mechanistic models. Laws in sciences tend to be very specific models that can be described mathematically precisely because they are so well defined. However they do describe physical relationships rather than mathematical ones. Most constants used throughout physics and chemistry are based on empirical studies and have no direct relationship from purely mathematically derived relations. They just behave and scale in a way that can be described mathematically.
  16. The very basic information is the order of the bases. It can refer to regions (or loci) that are coding for RNA but it may also apply to regulatory regions that are not transcribed. Nothing tells the bases how they are ordered per se, one strand just gets replicated complementary to the existing one. I.e. there is no higher ordering mechanism.
  17. I assume that you are supposed only to count plates which have between 25-250 colonies. If there are more counting them may be considered tricky (though actually quite feasible). The other reason may be that, if you look at the numbers, there was obviously some kind of mistake between 10-4 and 10-5 dilutions. Yes, you count the colonies for each plate and then calculated back based on the dilution on how many were initially in one ml. In theory you would also want to give average and standard deviation but with two data points it is not very informative.
  18. The description of the experiment is missing (what is being measured with what means). That being said it appears to me that only a description of what the differences between the enzymes might be is asked (what does the Km and Kcat tell you, describe the differences). Without knowing what experiment that is I can only guess but I think this should be sufficient. Especially as those abbreviations generally are not helpful in identifying them nor do I think that the sequence will help you in any way.
  19. There is some weird use of amplification here. Once inserted the plasmid may or may not be replicated in a given cell. If the gene product is not the desired one, generally a different strategy (e.g. different vector) has to be employed. Amplification generally for PCR reactions of particular DNA sequences which does not make sense in this context. Again, you amplify the gene you want to clone, put it into the vector, then into the cell. There is no need for further amplification unless you want to verify the gene inside a given cell. Generally integration occurs via homologous recombination. If there are sequence similarities between vector and chromosome (regardless of whether it was in the cloned fragment or the somewhere else on the vector) it can integrate as a whole into it. Depending on whether a second event occurs the whole plasmid or parts of it can be integrated. Additionally the plasmid can be lost again with, or without the exchange of the homologous region. The rate of the event depends on the similarity and the length of the respective sequence. There are several counter-selection methods out there. It works by disrupting a given gene due to the successful integration of a fragment into the MCS. In other words, the loss of the function of the counter selective gene, you can determine which of those which have been selected for the presence of the plasmid also have an insert. It does, of course not tell you whether it is the correct fragment so that you would have to make a another analysis (usually analytical PCR , sometimes with digestion or Southern). Fusing the fragment in question with another functional gene is more cumbersome and then you have the problem that you still have to verify if your fusion-construct is correct. This kind of defies the convenience that you get from the standard cloning vectors. Counter selection can be based on the classic blue-white selection or what many have, based on suicide genes. That is, genes without a disruption of the gene (i.e. with an insertion of a desired fragment) will die under selective conditions. So by including the selective properties of the vector only those cells survive that a) have the vector (e.g. selected by AB resistance) as well as a disruption in the suicide gene by a cloned fragment.
  20. First thing is to determine what kind of microorganisms are supposed to grow on the plates you used. This will limit the overall possibilities. The problem with fungi is that they tend to be a tad unspecific if grown on bacterial media. The diameter is itself not diagnostic as they continue to grow, of course. To put in other words, if the medium is highly selective and if what you have was a bacterium then the colony morphology itself could provide good hints on what possibly could be there, but if it is a fungus and the medium is just a full medium I am not sure how the teacher can expect proper identification without further analyzes. And btw. fungi tend to be a bit more unspecific in their habitats (or so it appeared to me). It is quite possible that the fungi were growing due to some contamination (i.e. they were not actively growing on chicken). And if the medium is highly selective it is possible that you won't get anything grown from chicken (I assume it is not a live one). And only now do I realize that actually two people have asked the same question.
  21. So it is better that the limits are defined by the insurance companies?
  22. What precisely do you have trouble understanding?
  23. jimmy, it is not quite correct to say that the carriers of the genes are not important. The gene-centered view just sees them as vehicles. As such it almost mean the opposite of If you are good at surviving as an organism then the genes also survive.. The reason for the gene-centric view is that organisms exhibit behaviour that are precisely contraproductive for survival. But they are important for successful procreation. From the viewpoint of an organism this behaviour is bad for survival. From the viewpoint of the gene, it precisely allow its survival. The survival of the gene, that is. And rather not try to divine the meaning from pioneer's post. Last time I tried I my eyes started bleeding and I messed up an important experiment.
  24. If the ion concentration on both sides are equal there is not gradient through which the molecules would move. If a gradient is made by pumps the molecules would diffuse freely from higher to lower concentrated areas. This can be harnessed by specialized proteins. And just btw. proton pumps have also been found to play a role in regulating the membrane potential.
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