How does toothpaste affect the microbial flora of the mouth? |
- How does toothpaste affect the microbial flora of the mouth?
- How did the ancients discover the value/concept of Pi? In what ways was it useful to their lives?
- What makes electomagnetic waves able to propagate without a medium and other not other waves??
- What two creatures are most closely related genetically, but look the most different physically?
- Is there any evidence of two seperate planets orbiting an object in the same path but not colliding?
- Are there the same number of Protons as Electrons in the Universe? If so, why?
- What happens when you use ackermann's function with graham's number as it's arguments?
- How does nuclear binding energy work and what are it's uses?
- Is there a way to do floor and ceiling functions using only 4 operators ( + , - , * , / )?
- How do electrostatic forces play a role in accretion and agglomeration of cosmic dust?
- What rare elements are used in modern CPU and GPU designs, and are there viable substitutes?
- Do each of our nerves have separate connections to the brain or do signals travel up a common pathway?
- How does the stop/start technology work in a modern car and why isn't the radio cut off when it starts again, like when I start an older car?
- Does saltwater have a net electrical charge? If so, how would you go about calculating it?
- If most average galaxy groups are discovered to contain supermassive black holes, like the recently measured NGC 1600, would that provide any evidence to contradict our current theories of dark matter being primarily nonbaryonic?
- Why do photons have energy?
- Why is time not divided into tens?
| How does toothpaste affect the microbial flora of the mouth? Posted: 15 Apr 2016 10:15 AM PDT Hi! I'm a microbial ecology M.Sc. candidate that works predominantly in soil. In soils, there is quite a bit of evidence that anthropogenic changes to the soil affect the microbial community and it seems (at least from what I read and work on) that this can sometimes severely limit the diversity of microbes to species and genera that are capable of withstanding the changes. For example fertilization can limit the ammonia oxidation community to a small subset of species that are capable of surviving at high ammonia concentrations and make better use of the substrate. The human microbiome is a pretty interesting subject to me even though my understanding of it is pretty limited. I've always wondered about toothpaste. I'm not sure what sorts of antibacterial properties it has and what exactly it's supposed to be doing to teeth... Does brushing your teeth 1 to 3 times a day cause the microbial community to shift towards species that can resist the perturbation? Could this practice cause us to have higher concentrations of bacteria that have negative effects on our health and hygiene (such as increasing the proportion of bacteria that cause bad breath or tooth decay)? It seems pretty amazing to me that we still follow a practice that has been around since before PCR and as far as I know, we kind of just accept it. Please enlighten me! Edit: As I watched the upvotes climb and the comments stay at 0, I thought about the similar scenario with soap. We wipe out most of the microbes every time we wash and let them colonize anew. I remember seeing some evidence that some bacteria metabolize odour-causing chemicals, but that by washing the "bugs" away, we end up stinking when we're no longer "clean". There is anecdotal evidence from a reporter that tried not washing with soap for a while and after a few weeks of applying bacteria (coincidentally the same ones I study in soil), when his skin microbiome had reached some sort of equilibrium (presumably), he stopped stinking. [link] [comments]  |
| How did the ancients discover the value/concept of Pi? In what ways was it useful to their lives? Posted: 15 Apr 2016 04:36 PM PDT |
| What makes electomagnetic waves able to propagate without a medium and other not other waves?? Posted: 16 Apr 2016 03:50 AM PDT |
| What two creatures are most closely related genetically, but look the most different physically? Posted: 15 Apr 2016 10:23 AM PDT |
| Is there any evidence of two seperate planets orbiting an object in the same path but not colliding? Posted: 15 Apr 2016 03:23 PM PDT |
| Are there the same number of Protons as Electrons in the Universe? If so, why? Posted: 15 Apr 2016 02:39 PM PDT This article (http://cosmology.berkeley.edu/Education/CosmologyEssays/The_Standard_Cosmology.html) states that Proton creation and Electron creation after the Big Bang occurred on different schedules. As such, there would seem to be no reason for their numbers to be equal. Are they equal and, if so, why? [link] [comments]  |
| What happens when you use ackermann's function with graham's number as it's arguments? Posted: 15 Apr 2016 03:42 PM PDT |
| How does nuclear binding energy work and what are it's uses? Posted: 15 Apr 2016 11:30 AM PDT |
| Is there a way to do floor and ceiling functions using only 4 operators ( + , - , * , / )? Posted: 16 Apr 2016 12:49 AM PDT |
| How do electrostatic forces play a role in accretion and agglomeration of cosmic dust? Posted: 15 Apr 2016 02:56 PM PDT This has a few parts to it.... first, how does the charge get attached to the dust? Second, if like charges repel, and unlike charges attract, how is it that the asymmetry of charges comes about which allows particles to stick together? Shouldn't a similar charging process make it so that the cosmic dust is charged with like charges making it repulsive? another related bonus question: how are dust bunnies formed? [link] [comments]  |
| What rare elements are used in modern CPU and GPU designs, and are there viable substitutes? Posted: 15 Apr 2016 08:54 AM PDT There has been a lot of talk about things like Indium for transparent semiconductors becoming scarce, but what about the most crucial chips in computing, the CPU and GPU? I know the chips are mostly made from silicon with small amount of dopants, but are these particular dopants rare, and how long could we go if they continue being used at accelerating rates? Moreover, supposing we wanted to change to a more sustainable alternative, do they exist? Could you make today's high-speed microchips with commonly available elements, or are we basically boned if we run out of certain rare earth metals? [link] [comments]  |
| Posted: 15 Apr 2016 08:20 AM PDT For the moment I'm considering our senses of touch, hot, cold... If the signals merge into some kind of central line then they would have to have some method of telling the brain where they originated. Otherwise, there must be a TON of wiring going up there! [link] [comments]  |
| Posted: 15 Apr 2016 08:16 AM PDT |
| Does saltwater have a net electrical charge? If so, how would you go about calculating it? Posted: 15 Apr 2016 02:17 PM PDT |
| Posted: 15 Apr 2016 10:19 AM PDT After reading about the recently measured supermassive black hole at the center of NGC 1600, which is considered to be surprising because it contradicts our current theories of such large black holes usually being found in large dense clusters, I wondered if this discovery (or, more accurately, the potential discovery of many more similarly-sized black holes in non-large and non-dense clusters) would have any impact on our current hypotheses that dark matter is likely comprised primarily of nonbaryonic matter. After reviewing the current evidence in favor of nonbaryonic dark matter (i.e., baryonic gas or dust would be visible, the observed abundance of chemical elements, not enough gravitational microlensing, and CMB anistropies showing most matter interacts only through gravitational effects), it seemed to a layman like myself that the potential discovery of supermassive black holes at the heart of most clusters, instead of only at the heart of large dense clusters, would offer evidence to refute these current lines of evidence. But I would appreciate someone pointing out how this would not, in fact, refute the current lines of evidence. Thank you. [link] [comments]  |
| Posted: 15 Apr 2016 07:56 AM PDT Thinking about photons as a particle, they are massless (as in, I assume, they have no rest mass). So by E=mc2, they should have no energy. The thought that comes to mind (and I've seen this 'explained' with), is that the actual form of that equation is: E2=m2c4+p2c2 Where more energy could come from the momentum of the photon. But isn't momentum defined as the product of the mass and the velocity? Is this different for photons, or is there another reason for their energy? [link] [comments]  |
| Why is time not divided into tens? Posted: 15 Apr 2016 03:48 AM PDT One day has 24 hours, one hour has 60 minutes and one minute has 60 seconds. This makes it harder to convert a year into seconds. Or for example if you said 2.5 hours had passed it would actually be 2 hours and 30 minutes that has passed. This seems illogical. In all European countries (as far as I know) we use the metric system which is basically everything divided into tens and makes convertion of meters to centimeters or any other conversion easy. To me, it seems illogical not having time be divisible by ten. Is it because seconds (or rather centihours?(a hundredth of an hour)) would span such a short time it would be impossible to count? Even seeing how much of the day has passed would be easier if you said there is 10 hours in 1 day. After 2.5 hours you would know that a quarter of the day has passed. And 2.5 hours would be 2 hours and 5 decihours. Or 2 hours and 50 centihours. (Edit: fixed spelling errors) [link] [comments]  |
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