CharonY
Moderators-
Posts
13257 -
Joined
-
Last visited
-
Days Won
149
Content Type
Profiles
Forums
Events
Everything posted by CharonY
-
In addition, Chinese grad students are almost aggressively sent abroad. Quite often they are preferentially accepted as students (at the very least because of their work ethics). This again results in further similarities. A general theme upon recently was that in China (and India) the technical skills were less developed (comparing to German students, I am not sure regarding American students, as to my feeling practical courses are also underrepresented here) mostly because the universities rarely had top-notch equipment. But this too has changed. Certain elite institutes have popped up with the proper equipment. With some luck they will be able to catch up. One can also follow this quite nicely in the quantity and quality of Chinese research papers during the last 10 years or so.
-
The Practical Importance of Evolutionary Theory?
CharonY replied to Flukec's topic in Evolution, Morphology and Exobiology
As already mentioned, evolution puts biological data into context. Without the evolutionary context you cannot assign functions to DNA areas, for instance. You would only have the pure biochemistry (ACTG), but no possibility of interpretation of this data. And this is only the simplest example I could come up with on the way to the coffee machine. Just wanted to add: this is because we assume an underlying phylogenetic relationship of proteins (and hence, certain DNA loci) and can infer functionality (though often not the precise one). Where is the bloody sugar? -
Technically you cannot get the correct molecular weight by using markers (at least not electrophoretically). The reason is that the electrophoresis separates by size, however the different bases possess different MWs and such at best you can only estimate the MW based on the DNA size. So my question is, do you really want to know the molecular weight, or the length of the DNA? Of course, both correlate, but the measurement of either may differ.
-
Actually the cut-off of silica columns can be tweaked. Regarding the microchips, what is emphasized just means that the material itself is hydrophilic. All microchip based DNA separation require a hydrophilic surface. This can be a property of the material, or you have to treat the surface (e.g. with oxygen plasma). In any case again, you require something in the channels (e.g. linear acrylamide, a sieving matrix, whatever) to allow for size separation. In other words, you employ similar techniques (with few exceptions as dielectrophoresis) in microchips as in conventional DNA electrophoresis. Advantages are mostly speed and sample consumption.
-
Ah, I am not a grad student anymore, however at least a part of what you describe is found quite often (at least according to own experience, as well as from mentoring grad students) . Maybe I should add that I am talking as a postdoc working so far in three different institutes (University as well as research institutes) in two different countries (Germany and USA). Just to put it a little bit into perspective on what I am writing here. First of all you are concerned what the PI thinks about you and the lack of communication between you two. The more serious part is lack of communication, however you are also overly concerned regarding your performance (in his eyes). I do not have details, so I cannot easily evaluate it, however in many, if not most groups the contact between PIs and grad students can be rather sporadic. That is, unfortunately, not unusual. However, you must be aware that you are building your own career. Your PI does not have to be a mentor (in fact, these cases are rather rare). If you cannot find any labmates, you will have to teach the stuff yourself or look in another groups for help. During my undergrad and grad times for "administrative" reasons I essentially had the lab for me alone and wrote my own grant proposals. It is slower than simply to do as you are told, but you learn a lot this way. Either way, do not be too concerned what the PI thinks about you, you are not in a popularity contest. You do have to get a grasp on your project, or draft a poject that better suits you, that is still within the scope of what the group does and which can be published. Publication being the main point here. Hardly any PI would deny you working on something publishable. If you think that you are not up to this and need more mentoring you can look for another PI. This again has its risk. People that jump ship are sometimes regarded with caution. Also you may run into precisely the same problems. So if you do change, check the group carefully and talk the both, the potential new PI, as well as your potential labmates. Be aware though, in many groups you will have to claw your way through your phd anyway. In my opinion the best way is to read the papers in the respective field, draft out a proposal that will allow you to publish (in most computational disciplines one should roughly aim for three publications or more during the phd, though there are differences in sub-discipines). Then talk to you PI and try to see how appreciative he is. If he wants to control every aspects of your work, but does not give any suggestions, then it is probably better to leave. If he lets you do the proposed stuff, then you got a chance. If he denies it, but gives a good counter-proposal, think about it. Edit: noticed a lot of typos, but cannot correct them all atm. sorry.
-
Actually this is not limited to microbiology. In botany cultivars are often used. I am not aware of a similar typification in animals, which makes sense as they were not categorized as excessively as crops or diseases.... Subspecies are sometimes but rarely used in microbiology (afaik, but then I am not a microbiologist). Mostly "strain" is used to designate certain lines. The same goes for (lab-) animals. These are, however, usually clonal lines.
-
Sorry, this does not make it really clear to me. Size separation are usually done in a matrix of whatever kind to exploit the morphological or weight differences (as DNA of different sizes do not differ in their overall chemical properties). Another method is for instance to exploit dielectric properties of DNA. While it does not require a matrix per se, one has to create areas of different electric potentials. Using e.g. silica columns only allows a very rough separation, that is, everything below a certain cut-off will not be retained within the filter. All of this can be done in an aqueous solution (though a certain amount of ions are needed), without an actual agarose gel.
-
No argument from me here. I tried to make clear that the call for a revision (however it is called) is not from a single source (like evo-devo) but from a variety of disciplines. Moreover it is less the need to integrate new findings, but to discard some obsolete one, which is more important in my opinion. Of course due to the fragmentation of biology proposals will always have a big influence from the discipline of the respective proponent. Just to get it correct, you mean you fear that there is a "selection-centric" view on evolution? Again, no argument from me here. Integration of molecular data is often rather complicated to translate into population genetics as some features were driven towards persistence within an organisms without actually benefiting the organism as whole, but yes I do agree to this point, too.
-
Also the density is dependent on the concentration of HCl 1.18 g/ml is at around 37%, around 32% it drops to roughly 1.15 g/ml
-
So it sounds to me that in Harvard alcohol is cheap and abundant?
-
Well, actually those classification are taxonomically meaningless, but are used as an ad hoc distinction in a variety of fields, usually focussing on one particular diagnostic or physiolgocal aspect like serovars, pathovars, biovars, etc. They often lose their significance outside the respective fields.
-
Could we survive without the bacteria in our guts?
CharonY replied to mrsemmapeel's topic in Biology
Let us put it into the right context. The only reason why lack of colon bacteria is lethal is due to the fact that harmful bacteria can reside there easily, killing off the organism. This can be even simply a bacterium from another part of the body. However, it will never happen within two hours. Period. A sterile organism in a sterile environment lives (with adjustments of the diet). Oh, I forgot to add, you get inoculated with bacteria while being in the womb. -
Actually I would not be disturbed by "simultaneously " either. And Y or V is a pretty dumb distinction. If you monitor it you either see blobs (microscopy) a three-dimensional mess (crystallization, AFM). Hardly except for idealized drawings will you see anything precisely like a Y or V. I would possibly give extra points for mentioning that.
-
Which build did you download?
-
Separation according to size or from other molecules?
-
Do you Think We Grow Thermophilic Bacteria in Our Kettles?
CharonY replied to jimmydasaint's topic in Biology
Hardly so. Most thermophilic bacteria also require a rather high pressure for stabilization. Also there is quite a large physiological jump between the aerobic bacteria you will find and (anaerobic) thermophilic ones. In other words, the temp changes are too fast, and there is not enough pressure to prevent the the water from boiling. What one can do, however, is to select for heat resistant strains. That is, having some rich media and keep it at 40-50° maybe. -
Could we survive without the bacteria in our guts?
CharonY replied to mrsemmapeel's topic in Biology
It is virtually impossible to simply sterilize the gut just by intake of antibiotics. In the worst case you would just select for resistant strains. Also you cannot take in a high enough concentration to kill all bacteria and still survive (as ABs are also quite toxic to begin with). In general, residual bacteria are of concern for intestine transplants, for instance. Stable sterile models are usually only established e.g. in mice. However, I recall a rather recent report in which a colon was sterilized and the de novo colonization by bacteria was monitored. I just cannot bloody recall the authors... -
Psst, thymine is methylated uracil. The T-arm requires to be highly conserved as it is one of the anchor form to maintain the shape of the tRNA. The modification (in this case methylation) ensure a higher stability. Also, the thymine is not directly involved in the codon pairing, so it does not have a direct effect on the translation per se, but rather has structural functions.
-
How about genomics and postgenomics (e.g. proteomics, metabolomics or any other omics that might eventually pop up). Biophysics is normally in the firm hand of physicists. Well not in our case cause we barged in and demanded to be heard but still....
-
One with a lot of function is the Staden package (probably more than you need). I think there is a built for Mac around now (OSX that is).
-
Wait a tick. What precisely are you doing with them? Seqman is normally used for sequence assemblies. So do you sequence your putative mutated area and use Seqman to assemble it? Or do you actually need a sequence alignment programm? Or in other words, what parts of Seqman do you really need? Sequence editors are around aplenty. I have to check whether there are Mac compatibles, though (I normally run them on a solaris or linux system)
-
Could we survive without the bacteria in our guts?
CharonY replied to mrsemmapeel's topic in Biology
In that case the documentary is clearly faulty. Especially because it has both been shown in humans and mice not to be the case. -
expression of Indy gene in drosophila
CharonY replied to ecoli's topic in Biochemistry and Molecular Biology
AFAIK the indy gene was primarily analysed as a potentially life expanding gene in Drosophila (which has been challenged recently). Given the fact that the transporter itself has been identified not so long ago, I doubt that there are very deep analyses regarding the regulation yet. Much less specific tissue-dependent regulatory networks.