CharonY

Species are kind of tricky to apply to bacteria, in terms of distinguishable phylotypes the last sequencing publication I remember put it slightly below 400 for the intestine flora and around 100 for skin IIRC. However, these habitats are very specialized ones. A minimum would probably involve chemoautolithotrophic bacteria. Depending on habitat, technically a single well-suited bacterium could easily survive (evolution would take care of diversity over time, however). Indeed.

This is interesting. I assume the research council is one of the major funding sources in the UK?

I think ajb means luck with the topic. Especially in experimental areas you may have great ideas but a) the experiments take bloody long and may still fail and b) the idea may have been excellent, unfortunately nature decides not to work that way. The very bright part can accelerate the undergrad time, but in the actual lab work things are slowed down by external factors, usually. However, sometimes (too rarely, though) things fall neatly into place.

First, I am not familiar with the effects of hypoxia, so consider my response in this context. However, house-keeping genes are rarely stable under each condition (especially during stress). This is something that has driven qPCR guys nuts. My question is therefore whether there is data to indicate that alpha tubulin is a suitable reference protein during hypoxia. You may want to check this out: J Matern Fetal Neonatal Med. 2004 Jul;16(1):55-9. The effects of hypoxia on growth cones in the ovine fetal brain. Morgan BL, Chao CR. Source For normalization purposes I therefore usually first test whether the reference (in this case house-keeping protein) is indeed stable throughout the experiment.

The requirements appear to vary between countries, disciplines and even between universities a bit. Most of the time it will require something published or at least publishable, though in some cases it does not need to be a peer-reviewed paper. In some rare cases it is admissible to self-publish, for instance, but usually only after approval by the adviser. Cases for this include e.g. someone beating the student in the publication race or money running out. The German system, on average, gave students a bit more freedom while pursuing their research, mostly due to the fact that most Profs have permanent position as part of their contracts on which they can put students. In the US many students are paid via projects or by TAing, which may limit time and/or scope. Of course in the end it depends on the style of the adviser how it really plays out (regardless of the system).

I would extend it to texting, which is probably worse than phoning. One advantage I might see from hands-free devices is that you cannot text and that you cannot drop it.

The fact part applies to the observation that allele frequencies change over time. In fact, only under very limited conditions can you expect these changes (i.e. evolution) not to happen. Just to clarify, evolution is defined as the change of allele frequency within a population over time. Everything else, including speciation, is basically a consequence thereof. The theory part mostly deals with the kind kind of mechanism that are involved an their relative contribution. For instance the role of horizontal gene transfer is quite a hot topic.

I meant it as comment to the OP, specifically to the academic timeline (I cross-posted with ajb), which depends quite a bit on the academic system. The field referred to physics in general, as there may also be certain differences when it comes to disciplines (especially post-graduation timelines). An interesting point is also the length of postdocs. In biology and in Germany the average postdoc length used to be basically 2x2 years, for example. In the US postdocs are, on average, more often associated with a project and can go up to five years. But then, it is expected that you find a tenure-track position earlier than in Germany (just to highlight some rough differences). This is basically what I heard, too. I also heard (anecdotically) that in marketing they also sometimes hire theoretical physicists especially in conjunction with the development if some statistical models.

This is an incredibly inaccurate description of the science landscape. Japan always was close to or better than leading European countries (as e.g. UK, Germany and France). China had little to offer when 10-15 years back but boy do they catch up. Not only in quantity but now also in quality. Some extrapolations even propose that they may overtake USA at some point, but right now I am still skeptical about it for a variety of reason. However, if they mange to overcome these and maybe create an even better structure than the one existing in many Western countries (instead of trying to emulate), all bets are off. Their hiring and expansion push and overall investment in science infrastructure over the last years is astounding, to say the least. India is also pushing heavily, especially in the area of bioinformatics. Also, recently I noticed very interesting publications coming from Brazil. For a more detailed analysis see My link. This, however does not really address the OP, which I still do not get. Science as a whole is pretty globalized as it is. Grants are for instance not awarded based on national progress, but on the overall existing scientific corpus. If it is not new and interesting in China, it is not in the USA, either. However, there may be frameworks that focus on different areas. NIH funds applied biomed science more likely than basic research, for instance. But these are usually very rough categories. Finally, there of course programs that are aimed to strengthen specific areas of research in a given country, but the overall progress would still be benchmarked against the whole body of science.

Not my field, but I assume that it may also depend on the country?

Did a lengthy answer and then the browser crashed. In short, your limiting factor is most likely to be your low mutation rate (i.e. a singular event). From memory (i.e. better check it out somewhere else, it may be wrong) the time to fixation for a neutral allele in the diploid case and for very low mutation rates goes towards 4N (i.e. four times the population size in generations). For selected traits it is (2/s)ln(2N) generations, with s being the selection coefficient. Note that these are average times (finally it may or may not happen). Note that even deleterious mutations can become fixed. For more details you may want to check out the papers from Kimura or some text books (e.g. Futuyma).

We are far from able to create a balanced ecosystem. The space station is not self-sustaining. The Biosphere 2 is an example to recreate a small ecosystem, which ultimately failed. Also, why would you consider an organism to be worth more than others due to their ability to communicate in a specific manner? Are you less worth if your abilities are in some way limited?

You are probably thinking of fixation. However, assuming that there is a positive selection for AA as well as Aa, it will take a long time before a gets eliminated (the probability function is a bit complicated, it depends on the selection coefficient, frequency in the population, dominance parameter, mutation rate etc. Note that fixation is always probabilistic, if your question is whether one or the other allele may get extinct or fixated, the answer is yes. It is just the probability that varies.

Well, depending on the country tuition fees can be pretty low. Germany has excellent unis and extremely low tuition fees (compared to the US or UK that is). In the long run it really depends on what kind of job you are looking for. I know, at this early stage it is really hard to envision what one would love to do for the rest of ones working life, also the mental image that one may have for certain jobs may be fairly inaccurate, if one does not talk to people who work there directly. An important point, however, is that a certain degree will not give you a job in a given field. If you want to go int biomed, you should first figure out what you would like to do. E.g. work in a pharma company, work in academia, etc. For instance, if you want to be an analyst in a given company, maybe check job listings and see what their requirements are. Most of the time degrees in biochem, molecular biology and similar are interchangeable, for instance. But as Timo pointed out, the first bit is figuring out what one wants to do.

This is odd. Normally I would have assumed that there is something wrong with the pocket or during the loading step, but you say that it is not the case and it happens with each gel? Does it only happen in the outermost lanes, i.e. have you tried running fewer lanes and see if it persists? Also, what loading buffer do you use?

As well as damaging several other organs, including kidney and heart.

Regarding the turnover: yes the regulation of oxidative stress response is usually fast. However, while it explains the increase of SOD activity, it would not explain catalase decrease. Usually enzymes like this are allowed to linger around before being degraded. If you really want to figure out whether there is some kind of modulation of activity as opposed to enzyme abundance change, I would advise you to quantify the SOD and catalase content directly. The easiest ways is mass spectrometrically, if you got access, or via Western. qPCR would be even faster but it is not trivial to translate mRNA changes into actual protein abundance changes. Also, as a matter of habit re-validate the assays, and see how significant the differences really are.

You may want to check whether there papers out there that have time-course experiments on oxidative stress. I cannot point you to a particular paper off the top of my head, but I know that I read some years ago. From a biological point of view expression changes of proteins within minutes is quite reasonable time for protein turnover. It depends on the specific stimulus and the respective underlying regulatory mechanism, of course. However, from my own experiments (again, years ago) I saw mRNA level changes in bacteria during oxidative stresses well below one minute (basically below time resolution). The effect thereof on protein levels is cumulative. The question that I have is in which time frame you expect DA exposure to result in oxidative stress (and by which mechanism). Direct exposure to oxidative stress (e.g. using paraquat or H2O2) only takes minutes to result in observable expression changes and does not require activity attenuation for that time frame.

What do you mean with free-trade in this context? Also, why would nation-based specialization be a consequence of it?

Darn, fell for it.

Isn't that vertical thinking?

Ideally you should work with cultured bacteria rather than swabs. It is kind of tricky go get good lawn based on a swab, especially as you are going to have a very heterogeneous growth including fungi. Also, streaking often does not result in a nice lawn, diluting the bacteria into soft agar and pour it tends to work better, or dilute them into media and use a spreader (not deionized water, as some bacteria are not osmotically stable enough to survive that). The well method is more accurate than using droplets. Alternatively, use a sterile piece of filter paper (with defined size) and soak it in the compound to be tested.

IIRC it was named this way because it is a glycoprotein (gp) with a molecular weight of 120 kDa. gp120 thus became its name.

There are a lot of varying reasons. Many of which are not centered on humans of the only worthwhile animal on earth. But even assuming that everything should only be geared towards human survival (something that I do not subscribe to) then the question is what do we need to conserve the ecosystem or at least maintain it at a level that may sustain human life. Just keeping foodstock around is clearly insufficient.

a) With PCR you can only detect DNA and (after RT) RNA. b) Activity is dependent on concentration and activation status.