

CharonY
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Contamination on a cell culture
CharonY replied to A.B.C's topic in Biochemistry and Molecular Biology
I would need higher magnification, but it could be yeast contamination (though the shape is a bit odd). Maybe also high aggregates of bacteria. Is the medium cloudy? Unfortunately this typically means that may be screwed as contaminated cultures are often hellishly difficult to purify. Normally you would decontaminate your workplace/incubation chamber etc. and reinitialize the culture. Even if separation is successful, your culture is compromised due to contact and exposure to endotoxins, so that you cannot trust any results you get from the otherwise. There are some people who will suggest things like e.g. antibiotics rinsing. But again, you will get compromised results with low reproducibility. -
Career in genetic engineering - wrong undergrad degree?
CharonY replied to jellybeans's topic in Science Education
Degrees account to astonishingly little, it is more important to figure out the career path. E.g. genetic engineering is not a career in itself, but a discipline. You mentioned you wanted to to do research. From there you have to ask yourself where and what type of positions. The vast majority of jobs will be in the private sector, though not necessarily in research. Academia, on the other hand, is more research-focused but is very competitive with very few jobs. So the first step is figuring out what job you want to have and decide from there what strategic decisions you have to make. Courses will not give you that. -
Agreed. Rapidly forgetting things is a symptom of rote learning (there is a very nice German expression: Bulimie Lernen = bulimia learning, where you stuff as much info as possible into your head, then regurgitate everything in exams. Establishing context in your mind will organize the knowledge in a way that allows you to apply that knowledge. Thus later on you will start deriving info based on context rather than just rely on memorization.
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If you want to look at protein folding specifically (which is a bit odd to me, considering how early in you decided on a specific topic), you should check out the local department of biochemistry and see what is going on there. If you have identified labs with work that you are interested in, ask them if you could work for them as an undergrad and go from there. If you are at a small teaching college or equivalent and want to go to a grad school elsewhere things are a bit trickier, though a good letter of recommendation tends to help in either case (to get into contact with research groups). Other than that, you may want a stronger focus on biochem or molecular biology. However, competing just based on GPAs usually boils down to the luck of draw, as the best unis tend to be overrun with candidates with excellent grades. But again, if you know what you want to research you should focus on the groups, not the school.
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It is the same for all STEM and for certain in North America as well in Western Europe. There are always exceptions in some specialized areas in a given time. However, once the new graduates are done, the trend may have changed (various branches of engineering have experienced this).
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I am not sure whether that is true. Sun-Tzu is not really that focused on deception though he highlights it as a very important aspect if it provides significant or essential advantages. The core aspect seems more to be the proper use of intel and exploitation of the situation and improving/optimizing military structures (there is quite a bit about moral and discipline, for example). The importance of intelligence and associated deception is likely the reason why Sun-Tzu is seen that outwitting is important. However, there are large overlaps between Clausewitz and Sun-Tzu in acknowledging the shifting nature of war and both have comments on assymetric warfare. The major differences I see is that Sun-Tzu has a broader view on the subject, whereas Clausewitz has a very systematic view on the nature of war as a conflict and approaches the issue with a very tactical mindset (war as an extended duel comes to mind). Sun-Tzu seems to promote situational awareness to a higher degree (though Clausewitz also has elements of it), and repeatedly highlight the importance of intelligence. The broader view of Sun-Tzu also extends to further consequences of the conflict, including drain on the populace and impact. Some are too detailed to be relevant nowadays (e.g. estimated costs of war chariots).
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Too much reductionism loses salient points. And the term outflanking is used in a weird way: Which kind of defies the point that Sun-Tzu makes that with proper intelligence, planning, military command structure and use of the environment you can overcome opponents that are superior in strength. Not in a given battle, but by draining resources (i.e. guerrilla tactics). You could use the term "outflank" here again, but then it would be used in opposing contexts and pretty much lose the meaning (i.e. the inferior group can outflank the superior one with tactics although the superior outflanks the inferior one with troops...). Another thing that is lost is that Sun-Tzu discusses warfare ranging from a global perspective (i.e. drain on markets and countries) down to tactical minutae.
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I think this assertion is very problematic and masks a lot of important points. Specifically the term "muslims" has to be more specific in this context. Specifically, the conflict involves different denominations of Islam as well as conflicts between various ethnic groups. ISIS is comprised of Sunni insurgent groups and are known for their anti-Shiasm. Thus one could interpret it that their goal is to create a Sunni rather than an Islamic state (which would incorporate other denominations). Even worse, they follow an extreme interpretation and acting out brutalities which are so bad that even al-Qaeda severed their ties with them. It is somewhat impossible to discuss this group without a closer look at their ideology. Even the declaration of a caliphate can be interpreted as a stab at other Muslim groups since they criticized the Ottoman empire and the later caliphates as impure. As such they are collection of radicalized Sunni insurgents but likely have little hope to gain support from the general Muslim population.
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Well, to be fair, even organisms that are close to us (i.e. those found on Earth) are quite alien and different if you look into them. In fact, biology has delivered us more varied and alien lifestyles than Hollywood. I would be curious to know whether extraterrestrial life could be any weirder than what we already have...
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Well, price and support does vary to some extent between countries so it is not that easy to generalize. We had bought large amounts from Abcam and Pierce mostly but also sourced from many other major companies. Unfortunately for custom antibodies it is a bit hit and miss. We never found a single company that could make all ABs work. Sometimes, for some reasons, a specific one would not work from one company, but sourced from another company (with same parameters) it worked in our hands. Some do not work at all, etc. In the end I would could go according to price (if you plan to do many customs they may quote you a better price) and just try them out.
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The main reasons for stroke is that they create lesions in the brain. If these are the areas that receive afferent information from a given part of your body, you will lose the ability to sense it. Re-learning is typically done by having other brain areas take over that function. Obviously for sensing the actual pathway (i.e. fibers leading from transducing neurons to specific brain areas) is used in conjunction with the the integrated signal (as typically heavy processing is done before signals reach the brain).
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Not even using old knowledge was the assumption you made 100% correct. The main issue is that you have a limited knowledge of the subject (which, again, is quite alright), which lead you to overinterpret things you need (which is slightly less alright). I feel there is too much I would need to convey to demonstrate all the points that you are simply wrong. And even worse, you like to argue from a position of ignorance rather than trying to fix the knowledge gaps. For example the Zotterman reference most likely just refers to the detection of certain fibers that react to both extremes. Yet, this does not mean that this is the only mechanism of thermoception, nor does it explain at all the illusion of the grill. That actually requires the action of two parallel afferent pathways. Again, something completely ignored (presumably because it was not understood). You claim that the mechanism behind the grill is a simple one and proposed early speculations as facts, whereas the actual understanding of the mechanism was elucidated around the 90s (though many speculations were debunked much earlier). A basic ignorance on the way neurons function is somewhat revealed in this quote: As I wrote above, thermosensors (and again, it is a different pathway than nociception) fire constantly at body temperature. However, for cold sensitive sensors, the frequency goes down, when the temperature rises, whereas for heat sensitive ones the frequency increases (and vice versa for cold sensation). It is not that suddenly there is an overflow of both types of neurons that suddenly than charge up or trigger nociceptors. They react to distinct stimuli. In fact, the way the grill works is because the cold sensitive fibers are not acting (as they have an inhibitory effect). Pretty much the opposite to your claim. You really have to understand that the sensation caused by the grill is physiologically distinct from actual harmful temps, in the latter case the nociceptors are triggered, whereas on the grill only the thermosensors are (and due to higher-level interaction it is perceived as burn). I really do not get the childish insistence on being right. The claim can be summarized that temperature and associated pain perception requires different afferent pathways that interact on the intermediate level and can be tricked using setups such as the thermal grill. The claim that every heat perception is requiring both cold and warm sensor neurons being triggered is simply wrong.
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Are we biologically adapted to living in North America?
CharonY replied to Anopsology's topic in Ecology and the Environment
Or to reiterate a point that Ophiolite made, if humans were not adapted to the situation found in the various geographic locations, we would not find humans there. -
No, it would not. Above a certain temperature the thermosensors do not react. That is what makes the illusion weird. I.e. it actually activates thermosensors that do not elicit the stinging pain, whereas during actual pain only the nociceptors are active, whereas the thermosensors are not. This is quite distinct from overloading. I.e. if the temperature is very high, the actual thermoreceptors are not firing at all. With regard to hot coffee and cold receptors, your answer/speculation is quite wrong again. The actual response is highly dependent on the type of thermosensory cell (or rather, its decoration with heat or cold sensitive channels). Some integrate information from high and low temps and change firing frequency accordingly. So typically fibers associated with cold sensing will fire continuously at body temp, increase firing rate at cold temps and, in case of hot coffee, will reduce their firing rate. What you mention is a speculation that was formed quite a while back, but is not substantiated by current knowledge anymore. See for example Craig and Bushnell, Science 1994 265/5169 p.252. Also note that you should have started off with the citation (dated as may be) rather than with own speculations to streamline the discussion. The reason for the presence of the pseudoscience is less the content, but rather the way information is presented. I.e. you were presenting speculations as facts and only now added a pdf that at least somewhat supported that claim. Of course, the pdf itself is not actual primary literature and only presented speculation by itself, which, as I pointed out, is simply not in line with current (well, about as current as I can remember last time reading about it, which is easily a decade year old) knowledge.
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It is mostly due to the rather liberal use of definition that resulted in the erroneous conclusions drawn in OP. There is a reason why precise language in science is quite important. For example this summary: Is a nice narrative, but either slightly wrong, if we keep things on the analogy level, or very wrong if we want to be slightly precise how the receptors actually work. The receptors are not coupled in any way, so there is no overload of one and another kicking in. Rather, you have a wide range of ion channels that are temperature sensitive. Their opening results in action potentials that are then subsequently (to keep it simple) interpreted as temperature sensation. These belong to the TRP family of ion channels and various members react to different temperatures. E.g. TRPV4 is activated at moderate temperatures (up to roughly low 30s) whereas TRPV2 reacts if a temperature of more than 50 is reached. While the mechanisms are, to my knowledge, not fully elucidated, it allows sensory neurons to react distinctly to a quite broad range of temperatures. Note that this is in reference to the "detect" part of the OP; i.e. The tricky part, however, is that in addition to thermosensors (i.e. neurons with these channels) nociceptors exist and react to a broad range stimuli (polymodal C-nociceptors are activated by heat, cold and pinching, for example). However, it is not that one system is overloaded and thus activating the others but there are parallel processing of this information as well as interactions of various levels. This forms the basis of the Thurnberg illusion, which, just to make clear, is physiologically distinct from how we typically sense harmful temperature. One important and somewhat confusing element is the grill activates thermoceptors, but not nociceptors. What actually happens is the following. The activity of polymodal C-nociceptors (that invoke the pain) are typically masked by the activity of thermoceptors that react to cooling. On the grill however, their activity is inhibited by the application of warmth. Thus the information from the thermosensors no longer blocks the activity of the the nociceptors letting the brain interpret the resulting signal as pain. Note that physiologically this is closer to what happens when the body actually experiences noxious cold (not heat). Thus the grill evokes a patterns that confuses the circuits by interfering with proper cold-sensing. To put it crudely it fuddles with the normal thermosensory circuits in such a way that the pain receptors suddenly tell the brain what is going on (wrongly) rather than using the proper pathways. Obviously, actual exposure to harmful temperatures would activate the nociceptors instead of the thermosensory circuits (i.e. not an overload, but parallel processing). In other words, OP is misinterpretating the illusion with the way how typical heat sensing is processed, which is alright, as it is actually quite complicated. However, the further extrapolation based on this misinterpretation is what pushed this to the pseudoscience area.
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Unfortunately degrees do not guarantee jobs anymore, as already mentioned a couple of times. The best chances are by networking, typically.
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Starting a lab for my daughter. Input appreciated!!!
CharonY replied to Crimson's topic in Science Education
The lab coat and goggles have very specific functions as protective gear. I would discourage using them outside of these situations, especially if there is a chance that she may want to become a student in an actual lab at some point. If she is used to wear them for fun it may put her in the wrong mindset. Likewise, at that age she should not do any experiments that require protective gear. Just to clarify, dressing up for a Halloween shot, certainly, but dressing up on a more constant basis, potentially not such a good idea. -
Whole Human Genome Restriction with Mfl I
CharonY replied to incub0x's topic in Biochemistry and Molecular Biology
In that case, the restriction looks pretty much as expected. It is just not resolved in the high MW area (the top would be around 1 kb). To see more (and see if it worked) you should go with 0.5-0.8%. -
Starting a lab for my daughter. Input appreciated!!!
CharonY replied to Crimson's topic in Science Education
You may want to pick up bird watching, if that is possible in your area. This has zoological and ecological aspects and gets her outside, too. -
Whole Human Genome Restriction with Mfl I
CharonY replied to incub0x's topic in Biochemistry and Molecular Biology
I presume you are using ultrapure water (or double-distilled) not merely deionized? More importantly, what % is the gel and is it really a 100bp ladder (a 6-mer enzyme should yield fragments with an average size of about 4 kb... -
Are we biologically adapted to living in North America?
CharonY replied to Anopsology's topic in Ecology and the Environment
Excellent information and just to emphasize, individual health issues did arise due to the agricultural revolution (not specific to wheat). However, this was also the only way to sustain the population and the eventual rise of civilization. Together, this has allowed humans to change their environment in a way that not not merely allow survival but ensures success in an unprecedented scale. Without wheat or other agriculture crops the vast majority of humans would simply have not lived, celiac disease or not. -
Protein isolation from mucus
CharonY replied to GeneMan's topic in Biochemistry and Molecular Biology
That is not going to work well. For OP, acetone precipitation is pretty much one of the fastest ways to concentrate and (to some extent) desalt proteins. With regards to cell removal it is not clear to me how lengthy your procedure is but typically involves centrifugation and/or filtration. In some cases there is even further extraction to remove polysaccharides but how crude the extraction could be really depends on what type of analyses you want to do downstream. -
Yeah, I need a citation for that.
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Short answer is: yes, most of the time. Depends on a lot of factors, though (e.g. length, purity buffer etc.).