dttom

A rapid cooling is required for supersaturated solution.

Though I think it won't be so appropriate to reply thread few years ago, but I still want to have a few words on genetic level or individual level of selection. I should agree that for each time of selection (who dies, who lives), natural selection acts on individual level, so at genomic level; however, in long run, why shouldn't it act on genes' level, fostered by crossing over in meiosis? A complication arrives with speciation that, as genes in a genome are bundled together, if a gene could not be resolved (if a gene is resolved, it got the chances to be in different genomes (of course in different individuals) for natural selection) before microevolution occurs, probably the selection level could stay at a higher level than a gene. When talking about a gene could only exert its effect in a given genetic environment (together with other genes), as in the case of any individual, I have to admit that this is definitely the fact. But does this fact affect or change the consideration in selective level is another matter. For me this is a fact stating that a gene could have different effects in different combinations of genes (actually I would prefer, and better to, use the word gene assembly), but as long as a gene could be resolved, it got the chances to be in different genomes, and individual gene effect could be selected by natural selection. The result could be a gene might exert more advantageous effect when combining with a set of other genes (actually this is usually the case as a phenotype, no matter is the traditional definition of phenotype or the extended phenotype, is usually determined not by a single gene), in this case, such a gene assembly would be advantageous if they have a low COV relative to each other (harder to resolved from each other), ultimate result might be fusion to a single gene (please beware of the use of the word 'gene', not cistron, a 'gene' here could refer to a number of encoded polypeptides) which is selected later as single unit (this might be refered to by someone as an evidence to support the allegation of selection at a level higher than gene, so for me it is not a matter of concept but a matter of definition, view of phenomenon and explanation).

I see, that means the ratio represents a coupling of the effects.

In this case there are more beta form (~64%) than alpha form (~36%), yet through anomeric effect the alpha form should be preferred with its anomeric hydroxyl group in axial conformation. So is this a counterargument or there are some other reasons?

Could you show the reference of this result?

They actually should have the potential to get cancer if our til-now understanding of cancer is rational. Also, experimental mice could get cancer otherwise they would have no value in cancer research study. So this potential is confirmed but if they do freqently get one in nature, it seems not to be the case as this disease grew popular together with the increase in lifespan of human. Hence probably it is not a freqent case in nature.

If the increase in oxygen partial pressure is caused by photosynthesis of a large amount of plant, probably it would spend the partial pressure of carbon dioxide. But carbon dioxide plays a role in stimulating breathing, and this is also why pure oxygen is not applied in securing people from inconsciousness without breating, so probably it has limited advantage on the other hand.

I think the percentage absorption depends on the oxygen partial pressure but not the percentage. So if the ambient oxygen partial pressure is applied, probably more oxygen would enter the body, beyond a threshold value this would pose the body into potential toxicity, maybe owing to the free radical nature and related species resulted of and from oxygen. Yet, oxygen generated from plant wouldn't change the partial pressure much, even people in tropical rainforest would not intake too much oxygen. So in general case it just wouldn't make much difference.

About your question of alkalinity helps opening up of ring form, would it be possible to be related to deprotonation of hydroxyl group on C1 favoring cleavage of COC bond? If this is a possibility, will acidic condition protonate hydroxyl group on C5, also favoring ring opening?

Maybe I put the question in a rather unclear way, let's clarify the matter. So I think the vibrational energy is quantized in this way, where the separation is constant in most of the cases. If assuming the ground state is at the tip of the well, and vibrational normal mode 1 is IR active, and now an IR-range photon with an energy hv = energy difference between vibrational normal mode 1 and the tip is given to the molecule, the molecule just does not absorb it. This seems to be quite a strange phenomenon to me. Now heat instead is given, there is another molecule colliding with that molecule mentioned, energy equal to the energy difference between mode 1 and tip is transferred, in this case the molecule absorbs the energy and vibrates with normal mode 1. This contrasts with the event when IR is given.

I actually don't know the name of its, but probably it's mechanism bases mainly on pressure and heat. When you grab the lower bulb, as shown at the beginning of the movie, the air is heated up and expands, pushing the blue liquid up to the upper bulb through the vessel; when you grab the upper one instead, the same happens and the liquid is squeezed back to the lower bulb.

So you mean there is a range of energy in heat energy transfer so virtually it could take any magnitude of energy so as to excite the molecule to different motion like translation and vibration? I understand that heat could transfer a range of energy but a photon in EM could only take a certain quantized energy. But in the example, the molecule was both given heat and EM (certain frequency). In case of heat given, certainly there were circumstances when the molecule was bumped by another molecule and transfered just enough energy for the molecule to vibrate in a certain manner. In the case of EM, though the frequency matches the vibrational frequency, the molecule just did not absorb the photon energy as it is IR inactive. It is actually the fact that the molecule was treated with the same magnitude of energy but in one case it took it yet in another case it just missed it which confuses me.

You got to check the stability of this compound, calcium peroxide. And you will see it really is an unstable one. Calcium ion is small compared to the large and polarizable peroxide ion, significant distortion in electron cloud resluts in instability. Other explanation should be possible, like if you treat this ionic compound as an acid-base adduct, based on the principle of hard-soft-acid-base theory you probably got the same conclusion.

I am not sure about the context of the question. You are talking about the extent of the reaction as that in eqm or the rate or any other aspect?

Thanks for the details explanation from Mr Skeptic and CharonY, I got the idea now.

It has been known that a molecule would absorb or not absorb an energy given to it depending on the method of energy delivery. For example, a molecule may not absorb a photon with an IR-range wavelength compatible to a vibration mode which is not IR-active, hence no IR peak at that wavelength would be observed. Yet, if the method of energy delivery is not through IR but heat, that molecule would absorb the energy given in form of heat and vibrate. My confusion is, both methods confer the same energy, one in form of EM wave, another in form of heat, why the molecule absorb one but not the other? I am not sure if it is about the energy quality of the given energy form (EM probably has a higher quality than heat, so in this sense the molecule absorbs a lower quality form of energy, which personally I think is quite weird...).

The basic principle in this biotech is the cut-open of a plasmid which acts as a cloning vector, better work with the one containing antiobiotic favorable for later selection process, followed by insertion of desired gene or gene fragment. After amplification and proper induction in gene expression, the protein product could be harvested. If it is not the protein wanted, simple amplification is enough for harvesting of the desired gene or gene fragment. However, there are instances when the sequence in the vector would be incorporated into the bacterial host genome, which I can't see to cause a trouble in the amplification process, but this makes the bacterial composition differential. This makes me to have a concern in under what circumstance would a plasmid be integrated into host genome with a comparatively high probability. Besides, one of the method in selecting those bacterial having absorbed the cloning vector is by alpha-complementation of an enzyme (adding a second part of an enzyme with a polyclonal site to an antibioticase-containing vector), which, though, is a rather old method. So there should be some more recent and more efficient method doing the same job. I wonder what would they be. I am actually considering ligating the desired gene fragment with an antiobioticase gene, forming an operon with single promotor. In a medium with suitable transcription factors and antibiotic, theoretically only those which have absorbed the desired gene should survive. But I am not sure of the actual feasibility of this method. Welcome discussion ^^

My question is short, how are the normal modes of stretching of C-H bonds in benzene look like? I think there are 12 of them, my thinking is: 1) s orbital of H interact with sp2 orbital of C 2) there are 6 pairs of them 3) each pair can either exist in bonding or antibonding so (A for antibonding; B for bonding): a) BBBBBB b) BBBBBA c) BBBBAA d) BBBABA e) BBABBA f) BBBAAA g) BABABA h) AAAABB i) AAABAB j) AABAAB k) AAAAAB l) AAAAAA I don't know why, but I think this thinking is wrong, please point it out and illustrate how can I figure out the number of normal mode and how they are look like when a certain molecular is given. Thanks.

reactivation with regulation measures might be an aspect... but definitely it costs lots of control work.

Usually a high concentration of RNA implies large demand for protein synthesis. Leukocytes in fact could be divided into lymphocytes and granulocytes. The former, especially B cell series, need to produce a significant amount of immunoglobulin, T-cell series also need numerous protein messenger molecules like cytokines; the latter needs to synthesise pharmacalogically active polypeptides.

I see the logic between Grignard reagent and phenol or aniline now. But what about that between Mg metal and phenol or aniline, would phenol be converted to Ar-MgOH, it seems a bit ugly though the aromaticity is still there if considering Ar-...

This reagent is able to convert aryl halide to Ar-MgX through formation of free radical of Ar., but I wonder why this could be done, as there should be resonance over seven atoms, but it becomes over six atoms after the reaction. I am not sure if the 3p orbital of Mg could participate in resonance. I also wonder if the Grignard reagent could be used for the same purpose with phenol or aniline, or those which more significant delocalization of pi electrons. Thanks very much.

But the acidity of bisulfate is far lower than sulfuric acid, so probably it is not a good substitute, and many reactions sulfuric acid could understand become very difficult or nearly infeasible with bisulfate.

Too hot the water would destroy enzymes. So I think this is to mobilize and dissolve the cell contents into the solvent rather than for enzymatic actions.

Thank you very much, that helps a lot.