

CharonY
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It is not a closed system. The formation of bonds releases energy, i.e. the folded protein is in a lower energy state than the unfolded one (in aqueous medium).
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Does an amoeba experience "hunger"?
CharonY replied to petrushka.googol's topic in Biochemistry and Molecular Biology
There are numerous metabolites that act as signal for energy and/or nutrient deficiency. This may include ATP itself or cAMP, for example. Nutrients are generally sensed via receptors on the cell surface which trigger signaling cascades that in turn control cell motility. -
Debating creationist - evolution and genetics
CharonY replied to SlavicWolf's topic in Evolution, Morphology and Exobiology
Most people do not enjoy these "discussions" as there is usually a distinct lack of knowledge that has to be cleared before any discussion could start. Do to various reasons, creationist are resilient to information, however. With regards to the genes, that discussion is mostly worthless, if one does not understand the nature of genes and how e.g. similarities are assessed. All human share the same genes, for example, but there are different allelic variances. That being said, all organisms share a large amount similar genes, though the precise number is not clear as we do not know the precise number of genes in humans either (estimates are in the order of 20-25k). But the large overlap between organism is very much expected for evolutionary reasons as most higher eukaryotes for example have very similar basal metabolic activities, cellular structure etc. Another thing to consider that fruit flies only have about 15k genes. So if all of them were homologous to human genes it would account to roughly 60% of the human genes. This just highlights that these comparisons without proper context are pretty much worthless. -
Yupp, it should be added that they are the result of the insertion of a fluorescent protein such as GFP or dsRed.
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That question is somewhat meaningless without context. Even point mutations that are not neutral (i.e. the altered genetic code yields the same amino acid, but even then there are certain exceptions) will at the very least result in an altered phenotype on the biochemical (i.e. protein) level. The effects increase with the amount of changes (a knockout will have stronger effects, for example). Whether these has any further effects depends on how and at which resolution you look at the organism. For example, if your criterion is survival, under certain environmental conditions a complete deletion may be harmless (e.g. if it disrupts some synthesis reactions, but you feed the fly the nutrient externally it may not matter), but looking at it on the biochemical level, the disruption would be fairly obvious.
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Debating creationist - evolution and genetics
CharonY replied to SlavicWolf's topic in Evolution, Morphology and Exobiology
That would be incredibly silly as it would have no connection to evolution whatsoever. -
Well, according to standard language use GMO specifically refers to genetically engineered organisms using a set of techniques that directly alter genetic material. Mutation breeding of plants is the only thing coming close but is usually specifically excluded (as well as regular breeding). Edit: and sorry, no pet giraffes in the foreseeable future.
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IQ heritability -a question to knowledgeable users
CharonY replied to SlavicWolf's topic in Genetics
Here is the thing, there is no Native American DNA. You will have mix of alleles (gene variants) that are found in almost all human groups (with very few exceptions in very small, highly inbred populations, maybe). In your population (depending on how isolated it is) certain combinations may be more common than in other populations. Also note that the composition of alleles in each population are not static and have changed massively over time. This is not only due to interbreeding but also due to selection and changes thereof. And example could be the accessibility of new food sources. -
Some conservative estimates place bacteria around 10E30 cells (based on soil estimates). Further, most larger organisms often carry a multitude of bacterial cells relative to their own with them (i.e. in a single human bacteria are about 10-20 times the number of cells found in a human!). Taking this together I would estimate the rate of bacteria much higher than 70% of all organisms (especially assumin that archaea and bacteria are both meant by it).
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Realistically this would have a higher chance of success by breeding rather than genetic manipulation. The current scope is usually limited expressing a limited number of proteins transgenetically, which would not work for a complex phenotype such as size.
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The first group, as you put it, refers to the knowledge of chemistry and physics, while acknowledging that there is a knowledge gap somewhere. The second just assumes that there is something there but has not inkling as to what nature it may be. The first assumption and any hypotheses derived from there can be subjected to scientific scrutiny. The latter provides no explanatory power whatsoever. However, this has been repeated ad nauseam.
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I am not familiar with anti-depressants, but for other forms of medication there are genetic markers that are associated with a lower efficacy of certain drugs. However, it would only be worthwhile if the genetic link is strong and the MD should be able to provide either FDA (or equivalent) and/or studies that have established that link (i.e. more than a single exploratory study). With regards to the actual DNA analysis, again I would go for approved diagnostic suites. Companies that make private analyses are often not approved as a diagnostic tool, mostly because there is little info with regards how accurate their analyses are. Note that most do not actually sequence but use a much cheaper but more error prone hybridization assay. If the MD is unable or unwilling to discuss these things in detail, it may be time to look for a different practitioner,
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Typical methods include re-isolation from gel, chromatography and equilibrium density centrifugation. Standard centrifugation would not allow separation.
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The dark stains? Bromphenol blue.
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As it was implied, promise of authorship is not worth terribly much. For starters there are no guarantees that a work will ever yield publishable results and even if there is one and even if authorship is granted, it may be at best at limited usefulness. Based on the available information there does not appear to be a good reason to stay, unless you are really considering joining the lab at some point. But then you should have more info on the likelihood of funding etc. Personally, I would not have made any promises unless I have the money (and actually want someone to join). And if it is dependent on external factors such as funding I would make it very clear before taking anyone in for volunteering. Problem with grants is that there is no way of predicting success but promising something and going back on this promises is usually not indicative of a good work relationship.
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Unfortunately, loopholes are really the big issue here. For the most part it appears to be voluntarily, something that has so far not impacted antibiotics use in livestock very much. And very unfortunately farms are the single biggest source of antibiotics release into the environment. Costly changes in the the way livestock is being raised are likely consequences, and I fear most farmers would no go that route.
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The energy flow is usually used in the context of energy loss during each step of the flow. I.e. the directionality does not refer to the cyclic nature of ecosystems (in which microorganisms can play multiple roles, for example), but rather to the steps of biomass consumption As such a given species can be at different levels depending on how the food chain is built. That, in turn depends on the aspects and details of a given ecosystem one tries to describe. Cycling is usually discussed in relation to material but not to energy (i.e. energy flow) as energy is obviously not recycled, but gradually lost at each step as heat (however the food web is structured).
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It is based on the very definition. Generally speaking, it refers to the energy flow through a food chain. During each step of consumption energy is obviously lost and there is no way that you can "unconsume" something.
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IQ heritability -a question to knowledgeable users
CharonY replied to SlavicWolf's topic in Genetics
That is a very unlikely scenario. Within the Ashkenazi Jews social status was largely coupled to family lines and there is no evidence that e.g. higher intelligence would improve reproductive success. Moreover, as it is a very closed society there is only a small gene pool on which selection could work. If there was a genetic basis a founder effect would be more likely. At the very least the high incidence of certain genetic diseases is probably the result of that. On the other hand, Ashkenazi Jews highly value scholarship, similar to many Asian cultures, which incidentally also score above average on IQ tests. Edit: I vaguely remember a few papers on this, but IIRC the one paper that argued for selection was more speculative and was based on conjecture instead of hard data (which is admittedly not an easy task). -
No, Craig Venter claimed it twice and in both cases they essentially just created a pruned down a bacterial chromosome (using two different methods) and inserted it into a bacterium that got its chromosome removed. Moreover, the reduced reduced genome originated from the very same organism. Claiming that a synthetic cell is a huge stretch.
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That is quite interesting, I had a student in my lab that sounded quite similarly. It was less in exam situations, but during working through protocol where the student would follow things very closely, except that it was not the correct protocol halfway through. It helped to write the protocols down, by hand, each time before an experiment was done (and inspected by me). But I really did not understand the issue. Interesting indeed.
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While interesting the big issue is the integration of parts into a sustainable entity (i.e. cell). We have been quite successful in manipulating or recreating bits and pieces, embedding proteins in vesicles and so on. So far we still have to put the stuff into an actual living cell so that things work (unless we talk about a simple membrane system, for example).
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I am not sure how pharmaceuticals could push for that. More likely is that they invest little into curing, unless there is a profit to be had. Health insurers on the other hand would love to have cures or support healthy life styles (though depending on system they offer various degrees to achieve this). I am not terribly sure how one could regulate that other than investing in research.
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IQ heritability -a question to knowledgeable users
CharonY replied to SlavicWolf's topic in Genetics
Your are quite ignoring relevant info given e.g. by iNow and Arete. The first paragraph could be true. However, the reverse is also true. If you take someone who scored well in IQ tests but do not provide sufficient support he/she inevitably will underperform. If anything that I have seen in college (and I think most of my colleagues will agree) is that academic achievement most strongly correlates with the willingness to learn, the ability to learn in an organized fashion and a strong personal interest in the subject matter. Oftentimes children that are labelled as "gifted" who are able to skip classes and get earlier college admission, eventually lose ground to their peers. Personal experience as well as studies showed that the advantage these kids have tend to diminish the more advanced they are in the academic curriculum. At PhD level there is rarely a notable difference (in some cases they underperform for a variety of reasons). Reducing everything to genes and neglecting the relevance and interaction with environmental parameters for intelligence is akin to claiming that obesity is solely the effect of genetics and has nothing to do with the quality and quantity of food intake. -
I have been reviewing quite a bit and I think I would agree with most points. Some comments though: Timeliness is an issue but it is very tricky to resolve. One has the editorial process to consider (including finding reviewers in the first place and then reading the reviews and rendering a verdict) but as a reviewer the problem is often to find the time to do it properly. Ideally, you want to have a few hours to read the whole thing, read up on recent lit in case you (or the authors have missed something) etc. Practically, reviewers (and often also editors) are providing free service, but are busy themselves (between class, lab organizing, doing research, trying to get funding, mentoring students/postdocs, department work etc.). Finding the hours to do a proper review can be challenging at times. Especially in multidisciplinary areas or areas that are in a more applied direction but without a strong theoretical framework reviews are tricky. In biomedical sciences for example (which tend to be high risk high reward type of research) often precise mechanisms are not known or extrapolated in order to find associations of diagnostic value or to define new treatments (to give some random examples). Even if statistically sound it is not trivial to assess whether the study will ultimately be validated. And ideal panel that would able to assess every aspect of a study (analytic methods, cell types, statistical methods, expert on specific pathways etc.) would be very unwieldy and would need additional experts that have specialized in multidisciplinary studies to be able to pull together all the individual aspects into a bigger body. Obviously that amount of effort would not be sustainable and could delay further research significantly. In some cases it is easier to throw out all the good and bad stuff and let the community figure out what is which. Admittedly, with the ever increasing amount of publications it is getting harder and harder. Replicate findings: This is basically impossible in most of the bio field, but not necessarily due to lack of info. Conducting the experiments tend to be in the order of months, more for more complex studies (e.g. establishing a cell line alone can take up to half a year). In addition, no one would pay for the work in the first place (molecular biology is notoriously expensive). In the end, the validity of a study in these areas have to be assessed over time, and demonstrated by subsequent work and citations. Professional reviewers: Sounds like an interesting proposal on the surface, However, without doing active research it will be hard to do but the most superficial research. Of course, things like statistical validity can be relatively easily assessed (although without knowing the analytical approach they may have a hard time figuring out e.g. if the data sets are dependent or not, for example). But if you are not an expert in the area, you will miss the fact that e.g. the method only has a certain dynamic range and hence the presented data looks just too neat. Or that a particular cell line has the propensity to behave a certain way under the given experimental condition etc. These kinds of things are widely known within the given communities, but a professional reviewer who is not up date with current lab practices and techniques will have a hard time to do proper review. And in my assessment, the longer they are away from active research, the harder it gets. It will depend on the are of course, and the stronger the theoretical background is, the easier I presume it is. On the flip side, the more experimental/empirical the area is,the more it will rely on experience.