Jump to content

CharonY

Moderators
  • Posts

    12631
  • Joined

  • Last visited

  • Days Won

    125

Everything posted by CharonY

  1. CharonY

    Suicide

    It depends on what you mean with most developed. But according to Wiki the highest suicide rates are in: Lithuania, South Korea, Guyana, Kazakhstan, Belarus, Hungary, Japan, Latvia, China and Slovenia. And I do not think that any of the parameters listed correlates well with the data. Chances are that cultural norms are going to play a role, but also the simple act of correctly reporting and counting suicides...
  2. That is incorrect, or rather only half of the story. The binding efficiency between receptor and target is also relevant. Hence different compounds with the same receptor can elicit different response strengths. This is incorrect, too. Only the trimethylxanthine is caffeine. The dimethylxanthine is also named theophyline, but not caffeine. Coffee and tea both contain caffeine as well as theophylline. The latter has a stronger physiological effect, IIRC.
  3. There are certainly rhodamine esters or isothicyanates that can be used for labeling of primary amines. Check Invitrogen (now probably part of Thermo), for instance.
  4. It depends on the type of analyses you want to run. For phylogenetic analyses you would therefore look for genes that are under more or less universal selective pressure (that is why ribosomal sequences are useful).
  5. Normally you build up skills during the PhD, so a good grasp of fundamentals and the willingness to work hard are more important. No one expects someone to pick up serious research skills during a short period of time (e.g. over the summer), Unfortunately there is also a certain focus on grades, unless you have already done undergrad research in someone's lab and he or she would like you to join (or at least write a letter of recommendation). That said, you should be aware that there are comparatively few pure research positions (i.e. being in the lab and doing experiments) out there.
  6. Basically these are all terms that relate to statistical analyses of sequences. In very simple terms, if you compare sequences and see differences, you have to somehow come up with a means to quantify these changes in a meaningful way, as you assume that the smaller the distance, the closer the sequences are related to each other. There are a large number of statistical methods to do this that are based on different models. Parsimony analysis is one of these methods. Further methods mentioned are then used to evaluate the quality and stability of this resulting tree.
  7. So termites are superior to, say wolves, because they are able to change their environment (i.e. in form of climatized hives)? And by the same note beavers are superior to most apes? What you demonstrate is a perfectly anthropocentric view that neglects the complexity of the interaction of organisms with their environment and with each other. In any case the OP was already deep in the speculation area and it should be continued from there (especially as no evidence has been provided why evolutionary trajectories should be similar).
  8. Antibiotics are used by bacteria (and fungi) way longer than humans even existed. Also thinking in terms of superiority does not make sense, biologically. Biology is dependent on complex interactions. There is really not top or bottom in it.
  9. That is an odd view. Why should bacteria kill us off? We are a nice habitat and an excellent source of food? Also terms such as stronger or weaker have little biological meaning.
  10. Agar is only a solidifier and it specifcally chosen as most bacteria cannot use it (and thereby degrade it). What allows them to grow is what else is in the medium. The selectivity of the medium can be rather low as in many complex media, or fairly selective.
  11. Yet, we happily serve as vessels for bacteria. And if they are unhappy we get all kind of conditions, ranging from acne to diarrhea to worse things. We clearly dominate those little bastards. Also good luck with maintaining decent nitrogen and carbon cycles without them. Or any kind of ecosystem, for that matter.
  12. HIV, maybe. Vaccines may become a reality (even if they do not offer perfect protection), and currently the progression of the resulting disease is relatively well controlled. Universal virus cure is very hypothetical at this point. It works in culture (afaik) but it is a big difference to have real clinical value. Schizophrenia: not a chance. We do not even have established a foundation of what it comprises of. Cancer has similar issues. Also, as they are not not diseases caused by an identifiable external agent (usually) but most likely due to normal bodily functions plus confounding factors, a remedy does appear highly unlikely. It is not that that we can simply remove something foreign from the body (such as a virus or bacterium) and suddenly turn healthy. Regarding genomics, there are gazillions of bioinformatical approaches used to investigate genomes. However, the real stumbling block is less the bioinformatics tools, but the biological knowledge on which they are built on. Or knowledge on some very basic aspects are lacking. Or rather, our total knowledge, while impressive, is still but a drop in the ocean of biological complexity. Biofinromatics can e.g. help us search or predict patterns, but they do not tell us what the biological consequences of these patterns might be.
  13. CharonY

    A Idiots Idea

    The problem with controlling stuff via EEG is that it is still relatively crude. Details such as words are not possible to decipher from the information you can currently got. But something like movement or facial expression can be read out and used to translate into a simple control interface, such as mouse movements, for examples. One of the examples is this here My link and OCZ had also a relatively cheap version.
  14. In short, they made a metagenome project and among the sequences they found gene homologs that looked very distinct from available sequences. The big question is whether this is due to the fact that these differences are due to low relatedness to known organisms, or whether it just means that we have not explored sufficient genomes yet. The dark matter alludes to the assumption that (if they really are a distinct domain) these organisms are unknown until now. One possible source are giant viruses and they were some studies that alluded that they belong to a very old lineage (which includes the paper mentioned in the OP as well as another from a French group under Raoult late 2010). However, subsequent studies (Williams et al 2011, also in Plos One) using different evolutionary models indicate that there is really little evidence hinting at a fourth domain based on these viruses. My personal take is also on the conservative side and I do not think that the experimental evidence is currently strong enough.
  15. That is historically correct, however, note that it is not a mechanism per se, but used to describe events at a given level. Events that span several gene pools as e.g. the split of species can be referred to as macroevolution. Or the investigation of divergence in different species. However it is not quite correct to say that macroevolution leads to speciation. The molecular mechanisms are essentially the same for macro and microevolution, just the viewpoint (and timescale) of investigation is different.
  16. A macro lens would be really useful for that.
  17. Well there are antiviral thiol-compounds, however IIRC they contain metals (which ultimately are responsible for inactivating viruses). The main point to remember is that viruses do not have a metabolism that could be disrupted, as such antiviral agents either harm the viral particles in some way (e.g. denaturation of the protein, oxidative damage etc.) or target infected host cells. Outside of hosts viruses tend to be relatively fragile as the protein hull is basically the only thing that protects their genetic material.
  18. Paraffin, wax and similar coatings delay blood clotting (but does not prevent it completely).
  19. This is because not all organism are pathogenic all the time. With a functioning immune system and a healthy flora many of these are harmless. Only once something happens to upset this (e.g. some other infections, weakening of the immune system etc.) do they start to become harmful.
  20. That is precisely the point. The hypothesis that certain areas have to be stimulated in a very specific way is most likely false (or at least there is no support for it). However, the big question is what placebo really is. It is an effect, as it has physiological consequences. More likely placebo may actually be a variety of mechanisms, and lumping them in a common catch phrase may actually make it harder to precisely define it.
  21. Ah, in that case it really looks like salt contamination of sorts. If the buffer already has different conductivity it is a source of concern.
  22. Most likely it refers to the analysis of protein expression under different conditions. E.g. a cell line under normal conditions (whatever is defined as normal) and the same cell line exposed to some kind of stimulus. Or a comparison of wild-type to mutant. The test then shows whether the protein(s) under investigation are expressed at different levels and are hence affected in their regulation by the stimulus/mutation.
  23. Moreover many animals including crows, monkeys and apes show culture (i.e. transmitting learned things from generation to generation). The assumption that humans are somehow special compared to other animals is based on an anthropocentric view, rather than on hard data. Not to mention the general problem in defining what consciousness is at all. How can we test other species when we are not sure of the mechanism in ourselves? Finally, regarding instincts. It is unfortunately a word that has been heavily misused. In the simplest sense it refers to innate behavioral pattern. However, almost all animals show the ability to learn. Except for very simple organisms their behavior is clearly not only instinctive.
  24. Not that many good ones, unfortunately. At least to my limited knowledge. I dabble into these matters every now and then as I found it quite interesting, but have not found any definite studies. Also much less that delves into the fundamentals of stress or pain perception. Or rather there is a lot, but there is a knowledge gap between mechanisms (also on the neuronal level) to the perception part, on which placebo (or whatever) could work. It is another typical case of insufficient biological knowledge to allow definite answers.
  25. It is quite possible, even likely that the placebo effect plays a role. The original theories behind it are clearly non-scientific (or at least have to my knowledge not put into a modern model with explanatory powers yet). The problem with these uses (pain control, sleep, etc.) are highly affected by the placebo effect. A quick overview of the published papers with trials showed that the placebo effect was mostly not accounted for (e.g. Chen et al Int J Nurs Stud. 2012 Mar 3). In at least one case acupressure was only simulated by touching rather then massaging ( J Midwifery Womens Health. 2012 Mar;57(2):133-8). But if te placebo is due to general massaging (and associated prolonged contact), it would still be an insufficient control. Finally a short study showed that acupressure, placebot-acupressure and relaxation CDs had similar effects for stress reduction: (McFadden et al. Complementary Therapies in Medicine Volume 20, Issue 4, August 2012, Pages 175–182). As a general note, the complexity of pain, stress etc. makes it really difficult to distinguish "placebo" from "real" effects. If lying down relaxes you and thus reduces pain sensation, is that a placebo or successful intervention?
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.