CharonY

Just to nitpick, that would be an approximation, not a lie. Other than that, Ophiolite's post applies.

The most robust and universal lysis method is mechanical disruption. But there are literally thousands of protocols for further steps. My main question would be what you are interested in looking at and how. E.g. 2D-PAGE requires something else compared to other chromatographic techniques. Also targeted protein analysis is different from proteome analyses and so on.

Bl21(DE3) is deficient in the Lon protease, thus reducing the chance of the degradation of the product to be overexpressed. Moreover, it carries an IPTG inducible T7 RNA polymerase. I.e. you can control the overexpression by cloning your gene downstream of a T7 promoter.

You have several values. Those that have cancer, those that don't, those that were tested positive, and those that were not. Draw a table with the FP, TP, FN an TN and try to assign the values. Tip 1: you can calculate percentages out of those numbers. Tip 2: If a population consists of two groups and the percentage belonging to one is 84%, what is the percentage of the other (remaining group)?

No, science is rarely about the data, but the hypotheses that explains them. A talk is always about a story, e.g. a problem and how it was solved or a question and the answer. The data is just to support the claim (and refute alternative hypotheses). Pure data collection results in data dumps generally of little value (with few exceptions).

PE is the observation of a possibly rapid change, due to a variety of effects. It could very well caused by the occurrence of a strong selective pressure. In that case a radical sweep through the population may occur resulting in a very different composition (as all with or without certain alleles essentially have low or no offspring) from a few generations back. This will then be observed as PE. Of course, stochastic effects are also likely (maybe even more likely) causes. PE is generally not that suddenly new phenotypes sweep through the population and are then selected. PE still relies on the gradual occurrence of mutations, for instance.

Punctuated equilibrium and gradualism are not really mechanisms, but just different and PE a slightly expanded viewpoints on the evolutionary history. Both are, in essence, descriptors for certain patterns. The mechanisms could be, in cases of PE, for instance the isolation of daughter populations.

First of all, who claims that evolution is step-wise? The only true steps are generations. Second, the papers themselves discuss models under which the existence and evolutionary relationship of these systems can be explained. In fact Woese already stated in the 70s that this was to be expected. Why? Because they promoted the view of an RNA world and the common ancestor of archaea and bacteria are assumed to have originated then. Edit: actually that was also in the paper. In the introduction section. Sometimes it pays off to read a paper.

It is a very French attitude and tradition. They love their strikes and protests. Similar things happened when they cut subventions for farmers, for example. I also recall a general strike in the 90s while the government tried to enact some kind of social reform or other (I assume social cutbacks). There were a few smaller ones, too. Essentially, if sufficient people are unhappy with government policy there, they strike and take it to the streets. More often than not, there are a lot of sympathizers (or people who just love enjoy a nice protest). Actually, I think that the first general strike ever held was held in France, too.

The media coverage definitively is. There is also an interesting comment from Shape (2010) discussing this issue. The main points being that the toxic effects of BPA have contrasting results in two large studies, with the newest one challenging the older. It has to be noted that all results on humans will, by necessity, be association studies. Right now the evidence is not strong enough to support any acute concerns.

I would like to point out a few things. First the study concludes that the media coverage is biased towards the more radical signs rather than showing a representative overview of all the messages displayed. This by itself is not surprising, considering how the media operates, but is still interesting. It does not, however, allow the conclusion whether racism is prevalent in the tea party (or rather more prevalent than in the average population). I could not find a precise methodology either, the only info I found after quick googling was that she photographed 250 signs. If that was all I do not think that the study is very strong (though would still allow first conclusion). Another study is more directed to this question, for example: My link But even if there were more racists within the tea party than the average populations, it does not mean that their basis is racism. It could be for instance that their composition is e.g. mainly white and thus their sample is not representative of the population. In other words, it could be a correlation effect.

Because all medicine/chemicals have a bunch of effects on the body.

No, it only means that a cell that is still maintaining its membrane potential is still alive. Membrane functions are just an indicator of cell viability, not the sole cause.

One should add that the concerns for BPA are not based on acute toxicity and hence the LD50 is less informative than one might think. the basic idea is that it disrupts normal endocrine signaling, leading to problems during development and, but the evidence is far less here, possibly also to various health issues in adults. In general exposure analyses do not deal with acute toxicity but rather with long-term and accumulation effects.

Also, from the viewpoint of the presenter it appears that you are not going to make an effort to understand his/her points, but are just going to collect data instead.

To be precise, there is no such thing as side-effect. It is part of their whole effect. It is just not the one that is desire under a given condition. However, the side-effect of a given medication in one condition can be used as an effect (or cure) for another condition. Essentially it is like saying that a potential side-effect of sugar is obesity.

For individual cells it is fairly easy to answer. The moment they are not able to sustain their membrane potential, they die. Integral to a cell is a separation of their cytoplasm with their surrounding. Once that is compromised, it cannot recover anymore.

That is not easy to assess. Theoretically one would have to measure each source of contamination and then figure out whether the intake could cumulatively lead to adverse effects. In most cases the levels are not high enough for acute effects and most likely infants or small children are more affected by it (due to the endocrine disrupting properties). Unless very unusually made something like a water cooker alone should not a sufficient source for toxic effects.

From what I understood the goal was to figure whether total expression levels have changed (which would be indicative of e.g. reduced activity/growth) rather than the occurrence and expression of individual proteins, which could be resolved in a proteome experiment.

Predicting the job market is almost impossible and most of the time it does not make too much sense to use the current market situation as choose a career. Note that getting degrees is not the same as building a career. If you are interested in a career, you should inform yourself what kind of positions are available in the field of your interest and what kind of people they need. Again, I am not necessarily talking about degrees, but the whole package. If you are interested in the alternative energy field, how about approaching companies (e.g. at job fairs) and ask about what careers they have available, and what you to have to get to become attractive to them. Purely academic positions are notoriously fickle, even if the economy is stable.

The format is not comparable to a lecture and there are essentially only a few main points that one should try to remember. Though I can see that for someone not familiar in the topic and/or being a student it is hard to figure out what the main points were. And sometimes the talks are so bad that actually no one is able to figure it out. In short, write down who the guy was, what the topic is,write down key references (knowing the topic should be sufficient in many cases to track them down even if only name and years are given). You will likely encounter parts that you do not understand (yet), do not fret, but make a short note and try to follow the rest of the talk. The conclusion slide is where you should pay a lot of attention. Do not try to make note of everything. It will keep you from listening. And again, the key is to find the main arguments, the data is just to justify the conclusions.

Moved to homework. Give a shot at an answer and we will give you hints. The general statement that enzymes can function in two different locations with respect to the cell is, as it is stands, erroneous, though.

KEGG is a very comprehensive database of metabolic pathways, if you already got targets you may want to look into the swissprot (one of the best curated protein databases). What I do not understand is what you try to accomplish. Which DNA sequences are you looking at and why do you think they will change? Or do you really mean expression?

Note that it depends also a bit on the status of your immune system. If you got antibodies against it your resistance is very high, but if your immune system is otherwise compromised, it may not be able to mount a thorough immune response and thus render you vulnerable. The chances are generally low, though.

Agar generally refers to the supplement to solidify culture media (as opposed to agarose for electrophoresis).