source string | id string | question string | options list | answer string | reasoning string |
|---|---|---|---|---|---|
OpenBookQA | OpenBookQA-4001 | biochemistry, metabolism, bioenergetics
Title: What is the energy source for adipocytes? Since adipocytes export fatty acids and glycerol and don't use them as an energy source, what is the main source of energy for adipocytes? Adipocytes use glucose as an energy source. They express the insulin-responsive glucose transporter GLUT4 just like muscle cells so that when blood glucose levels rise they are primed to take the glucose up for fatty acid biosynthesis, but they also use glucose as a fuel molecule.
The following is multiple choice question (with options) to answer.
What is a source of energy for animals? | [
"food charts",
"fire",
"grasshoppers",
"gales"
] | C | food is a source of energy for animals |
OpenBookQA | OpenBookQA-4002 | zoology, ecology, species-distribution, migration
Title: How do animals end up in remote areas? I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough.
They usually don't seem to be connected to each other. If it were any other land animal I would figure they walk from one spot to another, but in the case of frogs, I don't imagine their range is very vast. But often these marshy spots can be separated by fairly large distances to a frog.
So this brings me to my question: how do each of these spots end up with frogs in them? I don't imagine a frog is going to go hopping over a hill to get to a marsh on the other side, is it? This question pertains to organism dispersal, which is a very active field of study with relation to it's impact on conservation efforts. Much of what I will say below has been covered in this wiki.
Definition: From the Wiki
Technically, dispersal is defined as any movement that has the
potential to lead to gene flow.
It can be broadly classified into two categories:
Density dependent dispersal
Density independent dispersal
The question of frogs and fishes both refer to Density independent dispersal, while an example of density independent dispersal can be the competition for habitat space between big cats and humans (this is a WWF pdf)
From the wiki:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage
of various forms of kinetic energy occurring naturally in the
environment. This is referred to as density independent or passive
dispersal and operates on many groups of organisms (some
invertebrates, fish, insects and sessile organisms such as plants)
that depend on animal vectors, wind, gravity or current for dispersal.
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends
on factors such as local population size, resource competition,
habitat quality, and habitat size.
Currently, some studies suggest the same.
This study in particular studied the movement and habitat occupancy patterns within ephemeral and permanent water bodies in response to flooding. They found that during flooding these frogs moved out to flooded ephemeral water bodies and later on moved back again to the permanent ones.
Other suggested readings for those highly interested in the subject may include this (a phd thesis) and this (a project report)
The following is multiple choice question (with options) to answer.
amphibians hatch from | [
"trees",
"rocks",
"the sky",
"calcium life pods"
] | D | amphibians hatch from eggs |
OpenBookQA | OpenBookQA-4003 | java, reinventing-the-wheel, console, unix
With clothes the new are best, with friends the old are best.
He is truly wise who gains wisdom from another's mishap.
Beware of a dark-haired man with a loud tie.
Today is the last day of your life so far.
Flee at once, all is discovered.
Man who falls in vat of molten optical glass makes spectacle of self.
Go directly to jail. Do not pass Go, do not collect $200.
For a good time, call 8367-3100.
Those who can, do; those who can't, simulate.
Those who can, do; those who can't, write. Those who can't write work for the Bell Labs Record.
God does not play dice.
This fortune is inoperative. Please try another.
Laugh, and the world ignores you. Crying doesn't help either.
No amount of genius can overcome a preoccupation with detail.
You will feel hungry again in another hour.
You now have Asian Flu.
God made the integers; all else is the work of Man.
Disk crisis, please clean up!
You auto buy now.
Many are called, few are chosen. Fewer still get to do the choosing.
Try the Moo Shu Pork. It is especially good today.
Many are cold, but few are frozen.
The early worm gets the bird.
He who hesitates is sometimes saved.
Time is nature's way of making sure that everything doesn't happen at once.
The future isn't what it used to be. (It never was.)
Can't open /usr/lib/fortunes.
If God had wanted you to go around nude, He would have given you bigger hands.
It is better to have loved and lost than just to have lost.
A journey of a thousand miles begins with a cash advance from Sam.
Disk crunch - please clean up.
Center meeting at 4pm in 2C-543
I will never lie to you.
Spock: We suffered 23 casualties in that attack, Captain.
Your computer account is overdrawn. Please reauthorize.
1 bulls, 3 cows
It's hard to get ivory in Africa, but in Alabama the Tuscaloosa.
Waste not, get your budget cut next year.
Old MacDonald had an agricultural real estate tax abatement.
Snow Day - stay home.
Save gas, don't eat beans.
The following is multiple choice question (with options) to answer.
Cola and mentos combined will | [
"expand quickly",
"evaporate",
"freeze",
"disappear"
] | A | combining two substances chemically causes chemical reactions |
OpenBookQA | OpenBookQA-4004 | materials, optics
The problem is, all of this research is fairly recent and doesn't seem to have found its way to industry yet. I can't find many coating houses who sell super-hydrophobic optical coatings. Aculon's website says that they sell one, but they don't publish the contact angle, and the picture they show makes it appear to only be ~90$^\circ$.
Aculon also claims to sell an oleophobic (oil repelling) coating. This may work for you, but you would need to test a sample with the materials you plan to use. The video on their website shows someone trying to write on it with a Sharpie and it just won't take to the surface.
The problem with all of these coatings is longevity. Rain-X is an excellent example of a hydrophobic coating, but it must be reapplied once a month or so. My eyeglasses came with a hydrophobic coating which was very impressive when they were new. Now that they are 10 months old, everything sticks to them again. So, whatever you decide to build, you should be able to service it regularly.
The following is multiple choice question (with options) to answer.
Beach gear that protects your peepers and looks cool is | [
"sand",
"bikini beach volleyball",
"tinted glasses",
"swimming trunks"
] | C | tinted lenses reflect ultraviolet rays |
OpenBookQA | OpenBookQA-4005 | everyday-life
Due to friction effects though, option c is still best. Pedaling hard will quickly deplete energy reserves while pedaling at a slow but steady rate will allow you to cycle for much longer. From a physics point of view, we cannot help you spend less energy, it will inevitable take about the same amount of energy regardless of your method (some +/- due to friction, etc). But by keeping your power usage low, you can go much farther before needing a rest. It is much the same as with running and walking. Simplistic physics says both use the same amount of energy, but you won't get as far by running due to the massive power requirements.
The following is multiple choice question (with options) to answer.
Which of these can you use as much as you'd like of without diminishing it at all? | [
"natural gas",
"sunlight",
"good will",
"fossil fuels"
] | B | solar energy is an inexhaustible resource |
OpenBookQA | OpenBookQA-4006 | human-anatomy
Taken from here such people would be able to dislocate then get their hands in front and relocate.
The body can be trained to be quite flexible through training like gymnastics etc...
The following is multiple choice question (with options) to answer.
If a human has all their bones removed | [
"they are dancing",
"they can stand",
"organs are safe",
"organs will fail"
] | D | the skeletal system protects internal organs |
OpenBookQA | OpenBookQA-4007 | # Conditional probability exercise
Charlotte87
I have some problems getting conditional probability right... Does this look like it should?
## Homework Statement
Assume that there are bags of tulip bulbs in the basement, ant that they contain 25 bulbs each. yellow bags contain 20 yellow tulips and 5 red tuplips, and red bags contain 15 red and 10 yellow tulips. 60% of the bags in the basement are yellow, the others are red. One bulb is chosen at random from a random bag in the basement, and then planted
a) what is the probabilit that the tulip turns out yellow?
b) given that the tulip turns out yellow, what is the probability that it came from a yellow bag?
## Homework Equations
Let RB be redbag, YB yellowbag, RT red tulip and YT yellow tulip. Then as far as I can read from this exercise I have the following information:
P(YB)=0.6
P(RB)=0.4
P(YT|YB)=20/25=4/5
P(RT|YB)=1/5
P(YT|RB)=10/25=2/5
P(RT|RB)=3/5
## The Attempt at a Solution
a) $P(YT)=P(YB\cap YT)+P(RB\cap YT)=(0.6*4/5)+(0.4*2/5)=16/25$
b) $P(YB|YT)=P(YB \cap YT)/P(YT) = (0,6*4/5)/(16/25)=3/4$
It is particularly this last one I am unsure about.
Homework Helper
Gold Member
Staff Emeritus
Homework Helper
I have some problems getting conditional probability right... Does this look like it should?
## Homework Statement
Assume that there are bags of tulip bulbs in the basement, ant that they contain 25 bulbs each. yellow bags contain 20 yellow tulips and 5 red tuplips, and red bags contain 15 red and 10 yellow tulips. 60% of the bags in the basement are yellow, the others are red. One bulb is chosen at random from a random bag in the basement, and then planted
The following is multiple choice question (with options) to answer.
a student leaves a bag of acorns on the playground, which one of these will most likely take it? | [
"a fish in the pond",
"a dog in the house",
"a stray local chipmunk",
"a tiger in the zoo"
] | C | a chipmunk eats acorns |
OpenBookQA | OpenBookQA-4008 | human-biology, food, lungs
Title: What happens to the food you accidentally aspire? I'm well aware of the health effects of aspirating solid food and liquids, but I'm interested in the reaction of the body on the biological level to the strange body on our lungs.
After I almost aspirated corn, I started to wander: what does the body do when food got on our lungs?
Will it be eventually absorbed? Destroyed by our white cells? Or just lie there forever until it fully decomposes?
The body has mechanisms to prevent food to get into the lungs, so the body is aware that eventually some food will get into the lungs. As a result, it makes sense to believe that our body would have a mechanism to deal with such issue if all other mechanisms fail ( coughing and etc.,) yet I couldn't find anything on Google. People can drown because of aspired food. If they don't then it can cause diseases, for example pneumonia. In extreme cases a tree can grow in the lungs. There are other aspiration/inhalation related diseases like silicosis or asbestos lung cancer. So it depends on the composition of the object (or liquid or powder) and other factors whether it causes a disease or not. I did not find anything about what exactly happens with these objects in the lungs. Probably the lung tries to get rid of them mechanically, if there is no success in that, then they cause a local inflammation, which can lead to diseases if it becomes chronic and/or the object contains pathogens.
Common presenting symptoms (information available in 36 cases)
included dyspnea (14), fever (9), and cough (6). A history of
recurrent pneumonia was present in 9.
2007 - Pulmonary Disease due to Aspiration of Food and Other Particulate Matter: A Clinicopathologic Study of 59 Cases Diagnosed on Biopsy or Resection Specimens
The annual overall inpatient cost associated with pediatric bronchial
foreign-body aspiration is approximately $12.8 million. Combined, the
rate of death or anoxic brain injury associated with pediatric foreign
body is approximately 4%.
2014 - The national cost burden of bronchial foreign body aspiration in children
The following is multiple choice question (with options) to answer.
if a person takes in more food than their body needs at the time, what happens? | [
"they will become smarter",
"they will become tubbier",
"they will become lighter",
"they will become shorter"
] | B | if food is not immediately used by the body for energy then that food will be stored for future use |
OpenBookQA | OpenBookQA-4009 | ocean, ocean-currents, tides
Physical effects, then, are likely to include direct effects on current speed, sediment, and stratification.
The obvious possible biological effect is from collisions. This is not my field, but as I understand it no effect is likely on small fish populations from collisions, although individuals may be affected. Collision risk for large animals (e.g. sharks and marine mammals) and for diving birds is a topic of active research, and is likely (especially for mammals) to depend on their behaviour around the devices. No large animal collisions have been reported on any of the prototypes undergoing testing so far.
A good review of possible effects on benthic organisms is provided by Shields et al (2011). These may include,
The following is multiple choice question (with options) to answer.
As bad water increases in an environment the number of aquatic animals such as zooplankton will | [
"face extinction",
"stagnate",
"grow",
"hibernate"
] | A | if a population decreases to zero then that organism is extinct |
OpenBookQA | OpenBookQA-4010 | newtonian-mechanics
I should add that the above is simply what I, as a physicist with a fairly long experience, suspect is what is going on. It is not something I have read about and I am sure there is somewhere a more thorough discussion. So I hope I am right; I think I have a good argument. As I have described it above, I have in mind mainly the last part of the process where the wood only moves a little relative to the metal. In the earlier part, when the wood moves through a larger distance, it is inertia that is the main consideration, just like in the party trick where you abruptly whisk away a table cloth and the dishes on the table stay where there are. The more abrupt the better.
Added remark
It occurred to me that there is another thing worth mentioning here, that makes this method preferable to resting the axe head on something, or supporting the handle on a work top and hitting the head. It is that by hitting the end of the handle, with the head just hanging, you are going to deliver the force more accurately at the join, because it travels along the handle in exactly the direction you want. If instead you strike the head then there is a danger it will be knocked slightly obliquely, introducing a random tilt with each blow, which is liable to deform the wood and thus loosen the fit.
The following is multiple choice question (with options) to answer.
A pendant whipping indicates | [
"bulk air movement",
"patriotic magnets",
"a still atmosphere",
"aliens are attacking"
] | A | windy means high wind speeds |
OpenBookQA | OpenBookQA-4011 | organic-chemistry, physical-chemistry, biochemistry, alcohols
Title: Storage of Urine Not all may be favorable to this project, but I will explain what I am trying to do. I work at home, and instead of walking a moderate distance to the bathroom and loosing my focus, I've been, at times, peeing in a 3 Quart Poland Springs water bottle. If you take offense at this, please do not continue reading except to be helpful in the scientific goal. I know this subject won't suit many types of people, so just ignore it if that is your case.
I noticed first of all that urine is not at all as sterile as people say that it is. The rate of growth of bacteria is relatively slow, but as a precaution, I found the need to use additional measures to prevent the growth of bacteria. I settled on the following method: I have two bottles and I add to each bottle about enough salt as can be soluble in the urine and sometimes maybe a little more. The one bottle then fills up throughout the day and is emptied, washed, and refilled with salt. The salt helps to kill the bacteria which would be lingering in the empty bottle. The next day, the bottle stays empty and the other is used.
I would add that I discovered that the bacteria (without the salt) does not usually grow unless the bottle is left with urine for two days. After this, however, that same bottle (without the salt) would retain the bacteria and immediately grow, if used again.
This system works relatively well, so long as it is done every day. It will even withstand 2 days with only moderate growth. (If I should leave it by mistake for longer it can get ugly). Nevertheless, I am still looking to improve upon this. One reason is that, if I drink less water or relieve myself normally, the bottle does not fill in one day. I am looking for someone with knowledge of chemistry to help me find a substance that can be added to this solution which fits a number of common sense criteria. I will also add a list of the substances that I have tried or already considered.
Necessary qualities
The following is multiple choice question (with options) to answer.
Which likely can hydrate without moving? | [
"a panda",
"a bamboo stalk",
"a raccoon",
"a dog"
] | B | roots are a vehicle for absorbing water and nutrients from soil into the plant |
OpenBookQA | OpenBookQA-4012 | thermodynamics, atoms, phase-transition
But let's look at how the states change. In a solid, you have a bunch of atoms that can be thought of as masses connected by springs. As heat is added to the system, the atoms begin to vibrate in the lattice of springs. As more heat is added, they vibrate enough to break the springs. This is when the solid begins to melt and turn to a liquid.
Now you have a liquid where the atoms are all moving around but they aren't free to move wherever they want. More heat is added to the system and the atoms begin to translate faster and faster. Eventually they translate fast enough to overcome the forces that are holding them together in a liquid. Now they fly free and are a gas.
So ultimately, heat is energy that makes atoms and molecules move in some way. They may translate, rotate, vibrate, or the electrons may begin moving around depending on how much heat is there and what configuration the molecule has.
The following is multiple choice question (with options) to answer.
A solid has a fixed shape. When liquid is boiled and turns into gas, its shape is | [
"impermanent",
"talk",
"play games",
"smile"
] | A | Matter in the gas phase has variable shape |
OpenBookQA | OpenBookQA-4013 | evolution, taxonomy, ornithology
Title: Birds and Dinosaurs This came up in an argument with some friends. I know that birds are direct descendants of dinosaurs, shown pretty clearly through the fossil record. However, is it proper to say that birds are dinosaurs, or is there an actual distinction? I bet you'll be interested about the concept monophyly. Any human-made group of species (or taxon) like birds dinosaurs, primate, bacteria, angiosperm, reptiles, … are either monophyletic, polyphyletic or paraphyletic. This picture explain the concept When the taxon is monophyletic it is called a clade.
Monophyletic taxon are those groups of species that can be considered to be objective in the sense that it represents a group of species where each species in the taxon is more related (in terms of time to common ancestor, not according to their genetic similarity) to any other species within the same taxon than to any other species outside this taxon. This is obviously not the case for paraphyletic or polyphyletic taxon.
Typically, we do not consider a parrot or a deer to be reptiles. Therefore, the ususal understanding of "reptiles" makes this taxon paraphyletic. Now, one should not confound the common understanding (what is a reptile in our everyday life) with the strict definition of the taxon Reptilia, which is a monophyletic taxon (or a clade in other words). Probably the best source for exploring the tree of life is tolweb.org. Here, you will find the clade Reptilia (who include birds, snakes, turtles and lizards). Note: Mammals are within the Reptiliomorpha, not the Reptilia.
It is exactly the same issue with the dinosaurs. When we talk about dinosaurs in our everyday life we do not mean birds. But there is a clade called Dinosauria, which include both dinosaurs and birds.
In short, I would say that a bird is a Dinosauria (monophyletic taxon) but is not a dinosaur (paraphyletic taxon). But this little play on word is not a scientific issue but an issue of english usage.
You will also find in this post an introduction to phylogeny
The following is multiple choice question (with options) to answer.
Unlike bird eggs, reptile's eggs are | [
"symmetrical",
"Neon green",
"magical",
"watermelons"
] | A | reptiles lay eggs |
OpenBookQA | OpenBookQA-4014 | newtonian-mechanics, thermodynamics, energy-conservation, potential-energy, dissipation
Title: Potential, Kinetic, Thermal Energy? When things move, potential energy turns into Kinetic energy, right? Then how does Kinetic energy convert to thermal energy? "Thermal energy" is just kinetic energy.
When people talk about temperature, a typically good (but largely classical) idea is that tenperature is a measure of the average kinetic energy of the particles. When people talk about an increase or decrease of thermal energy, they usually mean something has gotten hotter or colder. This suggests that thermal energy is really just kinetic energy.
The following is multiple choice question (with options) to answer.
An example of thermal energy is | [
"crying in a school bathroom",
"trying to kiss someone",
"typing on a computer",
"Drying our clothes in the sun"
] | D | a thermal energy conductor transfers heat from hotter objects to cooler objects |
OpenBookQA | OpenBookQA-4015 | entomology, ethology, habitat
Title: Preferred criteria for new bee colony location As a human I want a house with a roof, indoor plumbing, bug free, and make my wife happy. I don't want to drive too far to work, and it has to be well-suited for offspring.
What are the criteria that define a "good spot" for a new location for honey bees. I'm sure it involves water, shade, access to nectar, and defensibility, but I don't know any of the details.
Has anyone ever made measures of this? Beekeepers? Apiologists? What are the things bees think are important, and what values of those do they think are "best"? According to Thomas Seeley, in his book, Honeybee Democracy, he gives the following as important criteria for honeybees when selecting a nest site when a bee colony moves to swarm:
Larger volume (the minimum nesting capacity was found to be around 14 liters with more preference to nests with a capacity of approximately 30 to less than 100 liters)
Relatively small entrance (10 to 30 centimeters squared)
Nest with the entrance located near the floor of a tree cavity
Direction of the nest entrance (south facing for thermoregulation during the winter)
Nest height (preference given to higher nests for colony defense)
Remnants of previous honeycombs (saves work and energy in building the nest structure)
Interestingly enough, bees did not necessarily display a preference for the shape of the entrance, the shape of the nest, the draftiness or dryness of the nest cavity (they are able to plug and waterproof nests).
Flower/nectar/food availability is not necessarily a direct factor as this changes quite frequently throughout the seasons and honeybees are not able to leave their honey stores (which are necessary to sustain the colony throughout the winter) or take them with them every time the colony has trouble finding food. Honeybees have a complex and efficient system for optimized location and sharing of food sources, therefore distance is not as large a factor.
The following is multiple choice question (with options) to answer.
If a hive of bees used to sleep through cold snaps, but now stay awake and productive during them, the hive probably | [
"melted",
"adjusted",
"subtracted",
"froze"
] | B | adaptation is when an organism develops a trait over time for survival |
OpenBookQA | OpenBookQA-4016 | # A stick is broken and its left part is discarded.Probability that one of them $>1$ [duplicate]
A stick of length $$2$$ m is made of uniformly dense material. A point is chosen randomly on the stick and the stick is broken at that point. The left portion of the stick is discarded and now again another point is chosen randomly on the remaining right portion of the stick and the stick is broken again at that point and the left part is again discarded.The process is continued indefinitely.What is the probability that one of the discarded left parts has length $$>1$$ m?
Formulating this problem we basically have a sequence of random variables {$$X_n$$} where $$X_1 \sim U(0,2)$$ , $$X_2|X_1 \sim U(0,2-X_1)$$,$$X_3|X_1,X_2 \sim U(0,2-X_1-X_2)$$ and so on. The probability that any one of the discarded parts is more than $$1$$ m is equivalent to say that it is $$1-P(\cap$${$$X_i<1$$}) But I cannot find the probability explicitly as it is dependent on $$X_1$$. Help!
The following is multiple choice question (with options) to answer.
If a thing is tossed and goes uncaught, then it will | [
"reproduce",
"fall",
"dissolve",
"burn"
] | B | dropping something causes that something to fall |
OpenBookQA | OpenBookQA-4017 | fluid-dynamics, states-of-matter
Title: Why does sweetness of coke change after freezing completely I freeze my coke in a freezer completely to solid and then keep it out to melt and as it melts portion by portion I starts to drink, initially It will be very sweet and later it wont be sweet at all. why does this happen?
We know that all sugar in coke will be dissolved (Solid solution) but how a major portion of this melts faster than water in the juice their by getting more sweet? How these sucrose can escape through the crystals formed by the ice and join in the water.
I measured the sweetness (Brix) and found it varies. Substances in solution have the effect of decreasing the temperature of the freezing point of the liquid they are dissolved in. This is called freezing-point depression. This is one of the reasons why adding salt to ice helps it melt.
Your coke is a complicated solution + colloid and sugar is one of the main substances dissolved in it.
During freezing:
What happens is that during the freezing process, as the coke cools a lot of sugar is pushed out of solution which allows the less-saturated water to freeze first. The last bit of liquid to freeze has much more sugar in it and takes a while to freeze because it is a concentrated solution and the freezing point has been lowered a lot.
During melting:
The last portion of the coke to freeze has the bulk of the sugar and the lowest freezing point and will melt first when warmed. When you allow the coke to start melting the most saturated portions melt the fastest and you consume most of the sugar in this stage. Later when the drink continues to warm the rest of the water starts melting with much less sugar in it, thereby making the remaining portion less sweet.
More information about sugar solubility:
One common way to grow sugar crystals is by slowly cooling the solution to push the sugar out of solution. There is some information about this here and they provide a nice sugar (sucrose) solubility versus temperature graph too:
As you can see the temperature dependence for solubility is dramatic. I haven't been able to find a curve for fructose (the primary sugar in coke in the United States) but I suspect the curve is very similar.
The following is multiple choice question (with options) to answer.
Skittles left in snow become | [
"hot",
"mushy",
"hard",
"soft"
] | C | something in a cold place becomes cold |
OpenBookQA | OpenBookQA-4018 | photosynthesis
Title: Photosynthesis in oxygen free enviornment If a plant is grown in an oxygen free enviornment would it live longer in light or darkness?
It is evident that oxygen would compete with carbon dioxide during various processes like competing with carbon dioxide for reducing power, also oxygen quenches the excited electron of chlorophyll etc.
But all these effects to me don't give any sense of the extent of oxygen on these reactions. What does the absense of oxygen have on the system? Except ofcourse the plant not being able to respire properly. If that "environment" is a closed vessel or bell-jar; certainly the plant would survive in light (when it simultaneously perform respiration and photosynthesis), and in darkness (when it can perform only the respiration) it would survive upto certain time due to the oxygen it accumulated. But should die at prolonged darkness when the plant would finish all the oxygen.
(as suggested by Priestley's classic 1870 experiment * there was enough oxygen to keep a mouse for certain time)
(image link)
However, if we look the effect of various concentration of O2 on photosynthesis rate without altering the CO2 concentration; yes the photosynthesis rate get affected; one known effect is called Warburg effect or Inhibition of photosynthesis by O2.
In this effect, photosynthesis rate only decrease if O2 concentration is increased. And in vice-versa, with O2 concentration decrease, photosynthesis rate only increase. (source: this, this, this and this)
This take place due to mainly 2 causes: 1. O2 work in competitive way with CO2 for binding with the enzyme RuBisCO, the key enzyme for CO2 fixation in plants. 2. And that induces photorespiration (in C3 plants). (Wikipedia shows reference to here). (However this old paper also tells other hypotheses)
The following is multiple choice question (with options) to answer.
What is a source of oxygen through photosynthesis? | [
"lakes",
"car engines",
"sunflowers",
"people"
] | C | plants are a source of oxygen through photosynthesis |
OpenBookQA | OpenBookQA-4019 | water, flow
Title: How is it that a cistern can collect rainfall, but a well cannot, even though both of them are holes? I imagined that a regular downpour or flood of rain would fall into the well directly, so I did a search on Google and was surprised to find this answer. But the article didn't make sense other than that the water would seep through the ground and in ten years, it would be at the water table, where it might, perhaps, refill the well. Still, I'm not sure what sets a cistern apart at being able to collect rainwater, since the gravity should be able to pull rain down.
If there is a better SE site for this question, feel free to move it. Without directing runoff rainwater into an open well it can only catch the rain that lands on its exposed surface area. This could only add a few inches at most in a single rainfall. A cistern directs runoff from a larger area into it, so it is fed by a much larger area than just the surface area of the tank.
The following is multiple choice question (with options) to answer.
If rain is something other than clean, then water in that area will | [
"be unsafe",
"be great",
"be safe",
"be clean"
] | A | acid rain has a negative impact on water quality |
OpenBookQA | OpenBookQA-4020 | kinematics, ideal-gas
translational (move from one place to another => linear momentum)
rotational (turn around => angular momentum)
vibrational (oscillate)
This last one (vibrational modes) is probably the most complex, especially for large molecules with lots of bonds which can 'stretch, bend and twist'... but thats a topic for another question.
The 'ideal' gas which forms the basis of the kinetic gas theory ignores rotational and vibrational modes, which is usually valid for monatomic gases such as helium.
The following is multiple choice question (with options) to answer.
Which is most characterized by the vibration of air? | [
"a viola",
"a brick",
"a blood cell",
"a flashlight"
] | A | matter vibrating can cause sound |
OpenBookQA | OpenBookQA-4021 | zoology, ecology, population-biology, ecosystem, predation
Title: Predator prey interaction I went through a line in my textbook which read:
"But for predators, prey species could achieve very high population densities and cause ecosystem instability."
I was not able to understand the meaning 'but for predators'. Can anyone please help me to interpret it's meaning?link to page where this line is mentioned
Edit: In terms of biology, I was unable to understand the meaning of the sentence, and I wanted to make sure that I don't misunderstand things... And this is why I posted the question.. I feel that the answer given is correct and in case, you find better explanation, please do post. I disagree with GForce's explanation; the meaning is not that growth of prey populations causes instability in predator species.
The sentence is merely saying that without predation, prey population growth is more likely to be at a level which leads to ecosystem instability. The term "but for predation" means "if it wasn't for the effects of predation". In other words:
"Ecosystem instability can occur when population growth of some species goes unchecked by predation."
See here for more explanation, where this example comes from in which it says that running a red light caused a crash:
"but for running the red light, the collision would not have occurred"
Biologically this makes sense in the sentence you show; without predators a species is limited by its supply of resources, and it can use these resources at an unsustainable level, whereas if you add predators to the mix there is additional extrinsic effects on population size, not determined by ecosystem properties such as space or nutrients.
The following is multiple choice question (with options) to answer.
An example of being a predator is | [
"an eagle landing on a branch",
"a mouse taking shelter in a hole",
"a wolf having a litter of pups",
"a bird catching worms in its mouth"
] | D | a beak is used for catching prey by some birds |
OpenBookQA | OpenBookQA-4022 | measurements, machining, metrology
http://www.tool-precision.com/kpt-62.htm
Or even a coordinate measuring machine (which will measure the actual height):
https://www.sinowon.com/micromea10128-moving-bridge-scanning-coordinate-measuring-machine
However, these bely what you actually need: You do not need to measure (i.e. quantify) the height to do this. You do not even need to measure the variance in height.
In the most primitive approach, your hands can feel the resistance decreasing, increasing, or staying due to the height decreasing, increasing, or staying the same as you run it along the surface.
Therefore, you need is a base, a vertical beam, and a sharp horizontal point that can be mounted on the vertical beam at any height. A so-called surface gauge:
https://www.starrett.com/category/111601
Now, you could then freehand and continuously check it until it is parallel. But from what I said above you can probably extrapolate that a much easier method in this case is to run a cutting tool at a fixed height similar to the probe. But if you so desired, you could freehand it to shape it. What you can't do is freehand the measurement part.
You use this to build your parallels. The longer you make your parallels (which also requires making a larger surface plate) higher the resolution you can check for parallelism.
Once you have your parallels you can start working on squares. For initial checks, you choose one arm of the square as a reference edge and align it to the parallel and trace the vertical edge. You then flip it and the more square it is the more closely the mirrored vertical edge will overlap/be parallel to the first traced vertical edge. Again, the longer you make the arms the more resolution you will have to check for squareness.
The following is multiple choice question (with options) to answer.
I can use a ruler to measure | [
"The smell of popcorn",
"the space between my toes",
"The length of air",
"how angry I am"
] | B | a ruler is used for measuring the length of an object |
OpenBookQA | OpenBookQA-4023 | newtonian-mechanics, waves, earthquake
The group of curves inside the envelope but outside (2)
As the quake starts to show up, the pendulum notes down every fractional increase of the it's magnitude. And so, the inclination of the ellipses totally curve out (perpendicularly) thereby forming new ellipses at right angles to the previous ones. Now you might ask me a question...
Why are the perpendicular ellipses confined to a small region and do not spread out?
As you can see in the image, each and every fringe in the larger ellipses are equidistant (somewhat) from each other. As the magnitude increases, the fringes begin to compress which could be noticed in the small ellipses. This shows that the quakes weren't too smooth. As the pendulum starts the ellipse, the quake forces it to wiggle in the exactly opposite direction. For this reason,
The group of intertwined curves at the center
This is very very simple than the others. The earthquake has increased to its utmost magnitude. Now, the ground has shaken in every direction which has confused the pendulum to oscillate everywhere. Luckily, it has also made a rose by its random twist & twirl...
The following is multiple choice question (with options) to answer.
an earthquake causes the ground to | [
"recite poetry",
"bounce and jump",
"grow fruit",
"run marathons"
] | B | an earthquake causes the ground to shake |
OpenBookQA | OpenBookQA-4024 | physical-chemistry, thermodynamics, gas-laws
Title: What will happen to the entropy and free energy of the gasses when the partition is removed?
Consider a container of volume $ 5.0$ L that is divided into two compartments of
equal size. In the left compartment there is nitrogen at $1.0$ $atm$ and $25 °C$; in the
right compartment there is hydrogen at the same temperature and pressure. What
will happen when the partition is removed?
$A) $The entropy decreases, and the free energy decreases.
$B)$ The entropy increases, and the free energy decreases.
$C) $The entropy increases, and the free energy increases.
$D) $The entropy decreases, and the free energy increases.
Logic tells that upon removing the partition, randomness increases and hence entropy increases. I am confused about free energy. First law of thermodynamics has to be applied , I think. But I can't seem to get the right direction. A Spontaneous process is characterized by an increase in the total entropy (for both system and surroundings).
Spontaneous processes are characterized by a decrease in free energy (analogous to the decrease in gravitational potential energy occurring for a ball rolling downhill).
The following is multiple choice question (with options) to answer.
Gas will rise when what happens to it? | [
"blazing temps",
"cooling",
"melting",
"freezing"
] | A | if gas is heated then that gas will rise |
OpenBookQA | OpenBookQA-4025 | species-identification, zoology, bone-biology, bone
Title: What is this bone from? This object showed up on my fire escape in New York city. It appears to be some kind of bone. It's a bit smaller than an adult human hand. What animal is it from? Given the size and thin/elongated ilia as well as the urban location, I think a domestic cat and/or a raccoon are likely candidates. I'm leaning toward cat.
Cat pelvis:
VCA Hospitals
Ventral view of domestic cat pelvis; Source: BoneID
Raccoon Pelvis
Anterior view of raccoon pelvis; Source: BoneID
I'm not an expert in differentiating these two species' bones. I will note that your specimen is more or less in between the sizes of these two species. Your size is probably closer to the raccoon, but a cat is just more likely given the location.
The most noticeable trait that stands out to me is the size/pointedness of the ischial tuberosity, which better matches that of the cat.
The following is multiple choice question (with options) to answer.
Which is likely to be in a zoo exhibit? | [
"an osprey",
"bacteria",
"a human",
"a dinosaur"
] | A | some animals live in zoo exhibits |
OpenBookQA | OpenBookQA-4026 | blood-circulation, kidney
Title: Why does glomerulus don't allow white blood cells to leave? The glomerulus in nephrons are just a ball of capillaries, so why can't it allow the white blood cells to squeeze though the epithelial cells into Bowman's capsule just like the formation of tissue fluid in other capillaries by filtration? Red blood cells, White blood cells, platelets and proteins with large molecular weight cannot pass through the podocyte and fenestrations in glomerular capillary, but small molecules like water, salts and sugars are filtered out as part of urine.
As these cells and proteins are large to cross through this filter, they remain in the capillary and create osmotic pressure within the capillary. Bowman’s space has osmotic pressure approximately zero. So, only hydrostatic pressure works in this state and help in movement of fluid across the capillary wall.
Via: https://opentextbc.ca/anatomyandphysiology/chapter/25-5-physiology-of-urine-formation/
The following is multiple choice question (with options) to answer.
What do white blood cells allow to stay in the body? | [
"viruses",
"oxygen",
"parasites",
"bacteria"
] | B | white blood cell destroys pathogens in the body |
OpenBookQA | OpenBookQA-4027 | evolution, taxonomy, phylogenetics, hybridization
Title: Are wild cats the same species as house cats? I thought that the definition of species is "can interbreed"
From Wikipedia:
The wildcat (Felis silvestris) is a small cat found throughout most of
Africa, Europe, and southwest and central Asia into India, China, and
Mongolia. Because of its wide range, it is classed by the IUCN as
Least Concern. However, crossbreeding with housecats is extensive and
has occurred throughout almost the entirety of the species' range.[2]
So why does it have a different name than the house cat?
From Species at Wikipedia:
A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, the difficulty of defining species is known as the species problem.
The following is multiple choice question (with options) to answer.
Bringing a stray cat to your home to live will be hard for it at first, but since animals adapt, it will | [
"fly away",
"go to space",
"get acclimated",
"breathe underwater"
] | C | animals adapt to their environment |
OpenBookQA | OpenBookQA-4028 | • Rotterdam apartments for students.
• Injury waiver form.
• Belgian Shepherd for sale Adelaide.
• Yugioh Card search.
• Vincenzo cast Instagram.
• The Grand Hotel entertainment.
• Biosphere 2 Discount Tickets.
• Disco Biscuits sessions.
• Is caviar good for Weight Loss.
• Frosted LED globe bulbs cool white.
• Human faces Drawing.
• Izuku has a horse quirk fanfiction.
• Party Venues with dance floor near me.
• Baby Girl Cowgirl Outfit.
• WordPress homepage settings missing.
• Instagram screen cut off iPhone 12.
• Beaumont children suspects.
• Avanade technology.
• Zolpidem efeitos colaterais.
• Facts about getting older.
• Advanced baby milestones.
• Izuku has a horse quirk fanfiction.
• MJ'' Harris net worth 2020 Forbes.
• String light Christmas tree DIY.
• Lemon basmati rice in rice cooker.
• Bahamas diving.
• Vinyl Works Pool deck.
• Makelaardij Friesland.
• Neewer Professional Panoramic Gimbal Camera Tripod 360 Panoramic ball head.
• Great Dane breeders in Michigan.
• Don't touch my phone wallpaper scary.
• How to sit with a fractured pelvis.
• Dr Brighten supplements.
• Harry and David promo code.
• How to fit bathroom ceiling panels.
• German Shepherd puppies for sale Wirral.
• Which president annexed texas?.
• Hampshire Garden Centre delivery.
• Helen Keller Pictures of her life.
• How to recover Viber pictures.
• How to fix watercolor painting.
The following is multiple choice question (with options) to answer.
Paul's dog has just pooped on the lawn. The dog has | [
"had a nutritious meal within the last day",
"gotten himself into trouble",
"had a lot to drink",
"been a good boy"
] | A | the digestive system breaks food into nutrients for the body |
OpenBookQA | OpenBookQA-4029 | thermodynamics, thermal-radiation, thermal-conductivity
Title: What can I do to be invisible for the IR-camera on board of a police helicopter? I think we all have seen the images of crime suspects, running in the dark of the night to escape the police, made with the help of infrared cameras. What can I do to be invisible to these cameras when I run from a bank I just robbed, through gardens, jumping over fences, but not running through long tunnels, or through woods with densely packed trees? When I run without having done anything (except robbing the bank) I show up on the screens connected to these cameras as a highlighted "blob" looking remotely human.
Should I wear a suit filled with ice, enclosing my entire body? Or would that also be visible, because in that case, I can imagine you see a dark human blob on the screen because the temperature of that suit is lower than my surroundings (unless it's a cold winter night, but let's assume it's a normal summer night or winter night if I lived on the southern hemisphere).
Should I wear a suit with excellent heat-isolation enclosing my body and which I've prepared in such a way that it has the same temperature as the air that night?
Keeping something (a big heat-isolating plate) above my head seems unpractical to me, and some parts of my body will certainly show up on the screen helicopter with the cops in it.
What else can I do to be invisible while still being able to run freely?
By the way, I'm not planning anything... Military gear is typically pretty good at trumping police gear. BAE systems recently came out with an adaptive camouflage system that can make a tank's IR signature look like anything they please
The next best approach is probably confusion. There's a long history of using Craigslist to put a "want ad" for people dressed exactly like you, then you rob a bank and the police don't know who to go after.
Failing that, an IR camera picks up heat, so anything highly insulative will be effective. My recommendation is something fuzzy, or made of foam. The fuzzy things tend to stay very close to room temperature
What could possibly go wrong.
The following is multiple choice question (with options) to answer.
What can humans hide from weather in? | [
"a shady tree",
"a local museum",
"a soda can",
"a playground"
] | B | shelter can protect humans from weather |
OpenBookQA | OpenBookQA-4030 | electricity, electric-circuits, electrons, electric-current, charge
Title: Electrons in an electric circuit , its movement and power delivered Does an electrical appliance convert electrons into its respective work , I mean is electron being consumed by appliance (say bulb ) and then this mass gives us energy.
or the same number of electron , just revolve around the circuit, then from where does power comes from, Electrons have charge and so when there is a potential difference across a circuit, this charge moves through it. In an incandescent light bulb, there is a high resistance, meaning that there are many atoms with which the charges collide, transferring some of their kinetic energy. No electrons are being "consumed" by the light bulb, i.e. the number of electrons in the circuit does not change. The ability of the charges to do work is because of a potential difference, which can be achieved through a number of means, e.g. using voltaic cells or electromagnetic induction.
To gain a better idea of why potential difference moves charges, consider two isolated point charges of opposite charges, one positive and one negative. If you pull the negative charge away from the positive one, you are doing work on it in the form of potential energy, as you are opposing the electric field of the positive charge. If you let go, the negative charge will convert this potential energy into kinetic energy, as it is attracted to the positive test charge. A potential difference across a circuit, albeit simplified, essentially does this – it brings electrons from a higher potential to a lower potential, converting potential energy into the kinetic energy in the process.
The following is multiple choice question (with options) to answer.
What provides the energy to open a doorknob? | [
"you",
"a ghost's hand",
"alloys",
"electricity"
] | A | a simple machine requires mechanical energy to function |
OpenBookQA | OpenBookQA-4031 | ocean, ocean-currents, tides
Physical effects, then, are likely to include direct effects on current speed, sediment, and stratification.
The obvious possible biological effect is from collisions. This is not my field, but as I understand it no effect is likely on small fish populations from collisions, although individuals may be affected. Collision risk for large animals (e.g. sharks and marine mammals) and for diving birds is a topic of active research, and is likely (especially for mammals) to depend on their behaviour around the devices. No large animal collisions have been reported on any of the prototypes undergoing testing so far.
A good review of possible effects on benthic organisms is provided by Shields et al (2011). These may include,
The following is multiple choice question (with options) to answer.
People dumping their trash in the ocean does what to the animals and plant life | [
"flies",
"types",
"dirties their habitat",
"reads minds"
] | C | humans discarding waste in an environment causes harm to that environment |
OpenBookQA | OpenBookQA-4032 | home-experiment, metallurgy
Title: Home foundry — melting aluminum, mitigating undesirables I am going to be melting aluminum cylinder head and some soda cans in the home foundry. I am aware the sulphur and the hydrogen present in the melt can make aluminum prone to cracks and brittle.
Are there recommended ingredients that can be put inside the molten aluminum besides flux that precipitates or remove undesirables? I never encountered S or C as problems in Al. The problem with hydrogen is that it can cause porosity as it is dissolved in the molten Al and comes out as a gas during freezing. Engine blocks and heads are usually Si alloys ( 5 to 12 %) like the wheels. They may have some Cu to make it hardenable. I expect contamination problems would be more likely Fe and Cu ( getting too high ). The cans usually have very little alloy.
The following is multiple choice question (with options) to answer.
a retailer gets an order of aluminum delivered weekly. Where is the aluminum likely coming from? | [
"it is coming from a school",
"it is coming from a mystery place",
"it is coming from santa claus",
"it is coming from a merchant"
] | D | a source of something supplies that something |
OpenBookQA | OpenBookQA-4033 | evolution, biochemistry, plant-physiology, plant-anatomy, life
Title: Plants without bacteria? is it theoretically possible? I know from school, that all live on the Earth need bacteria as low-level "machines" that break down/extract/convert/produce chemical elements and combinations, other high-level organisms needed. But it is a natural way.
But is it possible to have a world with plants (without mammals or microorganisms and without bacteria) that could exist in the long term. Saying the atmosphere of these world has already enough nitrogen, oxygen and CO2, and of course there is water.
What could break this artificially created world with such conditions (say the world created not from low-level living structures)?
Could bacteria emerge in the world? This is the sort of question that should be considered from more than one perspective. Since this is speculation, take it as a given that there is a lot of 'what if' here.
I doubt most animals and plants can do entirely without bacteria - as you say most of the essential nutrients come from bacteria, who fix nitrogen. If only plants were left on earth, eventually the plants would use up all the nitrogen and they would have to find a way to fix more.
Can bacteria emerge from just a world of plants? I don't think viruses arise spontaneously, but since genomes often have viruses embedded in them, over the course of a billion years or so, its possible since bacteria and viruses continue to be impressed upon our genomes. Would it happen in time? Most would be skeptical whether that timing could work out.
In practice it would be hard to create a world like this. I would be interested to see whether you could sterilize the microorganisms off of seeds without killing the plant for instance. If you're asking about a small sterile environment with only plants, you could do it by adding the nutrients the plants need and giving them sunlight. Such self sustaining systems have been made with cyanobacteria and i'd be surprised if plants could not be included. But these are closed systems and judged by limited amounts of time, so whether this is an answer to your question is not clear. Here it looks like some water plants and fish have been done. If there was a plant that created CO₂ at an adequate rate its possible.
The following is multiple choice question (with options) to answer.
Plants might use water and sucrose to create their own | [
"provender",
"pandas",
"friends",
"emotions"
] | A | an organism breaking down sugar is a source of water |
OpenBookQA | OpenBookQA-4034 | "Opposite" is a term lacking adequate mathematical definition. Opposite words for Root Vegetable. In simple arithmatic, they might simply mean the negative of the number, so the answer would be - ���3. The opposite of squaring and cubing are called square root and cube root. X Research source For example, suppose you wish to find the derivative of 3 x + 2 {\displaystyle {\sqrt {3x+2}}} . The final answer is . DNS: Admin: "Use root hints if no forwarders are available" results in the opposite behavior if toggled in W2K8 DNS snap-in Install a Windows Server 2008 SP1 or SP2 DNS Server. Thus reciprocal of 8 would be 1/8 One Dimensional Root (Zero) Finding Description The function uniroot searches the interval from lower to upper for a root (i.e., zero) of the function f with respect to its first argument. When you need to use the opposite of basic operations ��� addition, subtraction, multiplication, and division ��� you need to remember how the additive inverse and multiplicative inverse work: The additive inverse is the number with the opposite sign. sqrt2/2 The reciprocal of a number is 1 divided by the number. Substitute the value into . Root definition, a part of the body of a plant that develops, typically, from the radicle and grows downward into the soil, anchoring the plant and absorbing nutriment and moisture. a bound inflectional or derivational element, as a prefix, infix, or suffix, added to a base or stem to form a fresh stem or a word, as -ed added to want Is the opposite of metaX that is sought here supposed to be (1) something that stands to X in the relationship that is the opposite of the relationship expressed by meta-, or (2) X that is not metaX? Cytokinins play opposite roles in lateral root formation, and nematode and Rhizobial symbioses Plant J . Additionally, we discussed a specific type of tear ��� the bucket handle tear.. Opposite definition is - set over against something that is at the other end or side of an intervening line or space. Also known as the [analog root] (Opposite of the digital root!The digital root of a number is the continuous summation of its digits until it is a single digit, for
The following is multiple choice question (with options) to answer.
which one of these is approximately opposite in acquisition to doing chores? | [
"instinctive behavior",
"cleaning the yard",
"mowing the lawn",
"washing the dishes"
] | A | doing chores is a learned characteristic |
OpenBookQA | OpenBookQA-4035 | evolution, botany, development, fruit, seeds
What is the point of fruit if not to be eaten? It’s my understanding that organisms will adapt to survive and thrive. I understand that being eaten can spread seeds, but this just seems like too much of a risky tactic to rely on.
Following on from part one: If being eaten is the best way to spread seed, why do some plants avoid this (such as by being poisonous or thorny)? Seeds are spread by many mechanisms
Wind dispersal: When air currents used to spread seeds. Often these plants have evolved features to facilitate wind catching, for example dandelions. Aka, anemochory.
Propulsion & bursting: When seeds are propelled from the plant in an such as in these videos. This is called Ballochory.
Water: Similarly to wind dispersal plants can spread seeds by water movement/currents, aka Hydrochory. This is used by many algae and water living plants.
Sticky Seeds: There are many ways a seed can attach to the outside of an animal - by using hooks, barbs, sticky excretions, hairs. Seeds then get carried by an animal and fall off later. This is epizoochory.
Fruiting: Plants can use seed-bearing fruit to encourage animals to eat the seeds. They will then be spread when the waste is excreted after digestion. This is a process of endozoochory.
More than one way to spread a seed
The following is multiple choice question (with options) to answer.
When a varmint eats a pear and discards the seeds what will develop | [
"a tree",
"flower",
"debt",
"an ant mound"
] | A | An example of seed dispersal is animals eating seeds |
OpenBookQA | OpenBookQA-4036 | thermodynamics, energy, electricity, efficient-energy-use
Title: Cutting down on power by bypassing mechanical to electrical conversions: Why not? The only answer to this I can think of is energy portability issues.
Another modern-world insanity is converting mechanical energy to electrical, only to turn it back into mechanical. The example I like to use is a refrigerator's reciprocating compressor.
If we directly attach a steam turbine's axle to the crankshaft of the compressor, we will not need to suffer losses in heat in our conversion of mechanical to electrical (at the power plant) then back to mechanical energy (in our appliance). Long ago, a primitive factory used one big engine or turbine or water wheel to rotate a set of overhead shafts, from which leather belts were suspended at intervals to power small pieces of machinery scattered throughout the factory. This arrangement was inflexible in that when the single big engine stopped, so did the entire factory, and when electricity came into common use, this overhead shafting arrangement fell quickly out of favor.
The power losses in long-distance electrical power transmission are more than made up for by the ease with which it is performed and the flexibility it affords. This makes "local power generation" as you describe it impractical because a hundred small steam turbines are much more wasteful of heat energy than one large turbine.
The only practical exception is integrated co-generation in which a small engine running on, for example, natural gas powers a generator while also spinning the shaft of a heat pump. The waste heat from the engine's cooling system makes residential hot water, the waste heat from its exhaust goes through a heat exchanger to provide hot air for space heating, the heat pump furnishes air conditioning (or pulls heat from outside the dwelling) and the electricity from the generator powers up your small appliances in the home while also charging a set of batteries.
Overall thermodynamic efficiency of such a device can exceed 95%, and examples of this technology are just now coming onto the market.
The following is multiple choice question (with options) to answer.
Within a power station meant to process coal, electricity is | [
"reaped",
"broken",
"destroyed",
"devasted"
] | A | coal is used to produce electricity by burning in coal-fire power stations |
OpenBookQA | OpenBookQA-4037 | rainfall, tropical-cyclone
But perhaps to visualize the scale involved in creating a catastrophic largescale flood such as Harvey, this plot, created from a base image from pivotalweather.com, best shows the conditions around the storm (from the GFS model):
Basically the atmosphere of the entire Gulf (and beyond) is being pumped into the southeast Texas area. So although the air can only hold a couple inches (some 50 mm) of water, and evaporation rates are typically only a fraction of an inch (several mm) per day... bringing that together from such a large source region, and focusing it down into one small area... can lead to these awful extreme deluges.
Addendum: It should also be highlighted that the NHC adds in their report on Harvey that rising motion was also enhanced by a front which had stalled in the area. Air being advected in by Harvey's flow would naturally rise over that layer of cooler air when moving inland (a process called isentropic lift), which proves particularly efficient in condensing out the (abundant) moisture en masse into rainfall. Most substantial regional floods require similar existence of a significant broad lifting mechanisms overlaid with such a relentless inflow of warm, moist air.
The following is multiple choice question (with options) to answer.
An extremely rapid surge of rising flood water that moves across usually dry land at about 30 feet or more each second is powerful enough to | [
"keep the land dry",
"lift and carry a tall mountain",
"lift a 250-ton object off the ground",
"reach high in the sky"
] | C | when a body of water receives more water than it can hold , a flood occurs |
OpenBookQA | OpenBookQA-4038 | ### Show Tags
07 May 2016, 04:31
[quote="marcodonzelli"]A nickel, a dime, and 2 identical quarters are arranged along a side of a table. If the quarters and the dime have to face heads up, while the nickel can face either heads up or tails up, how many different arrangements of coins are possible?
A. 12
B. 24
C. 48
D. 72
E. 96
No of ways when nickel face head=4!/2!=12
no of ways when nickel face tail= 4!/2!=12
total no of ways =24
Verbal Forum Moderator
Joined: 02 Aug 2009
Posts: 4565
Re: A nickel, a dime, and 2 identical quarters are arranged [#permalink]
### Show Tags
07 May 2016, 04:39
2
KUDOS
Expert's post
Hi, shouldn't the answer be 48.
For the Nickel and the Dime, we can select 2 places out of 4 in 4C2 ways followed by the arrangement in 2! ways. The two quarters then can have 4 combinations (HH, HT, TH, TT).
Hence the answer = 4C2 * 2! * 4 = 48. Please suggest Bunuel.
Please ignore any typos as I am new to this forum.
Hi,
It says that quarters and dime have to be faced heads up..
ONLY Nickel can be either head or tail..
so Nickel can be placed in two ways..
ans 4C2*2!*2= 24..
_________________
Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
Intern
Joined: 11 Apr 2016
Posts: 10
Re: A nickel, a dime, and 2 identical quarters are arranged [#permalink]
### Show Tags
12 May 2016, 10:08
chetan2u - yes, misread the question. thanks.
Intern
Joined: 10 Sep 2016
Posts: 18
Re: A nickel, a dime, and 2 identical quarters are arranged [#permalink]
### Show Tags
The following is multiple choice question (with options) to answer.
a person places a dime next to an object on a table. The dime moves toward the object on its own. Which of these is likely to be that object? | [
"a piece of paper",
"a can of coke",
"a loaf of bread",
"a piece of carbon steel"
] | D | carbon steel is always magnetic |
OpenBookQA | OpenBookQA-4039 | python, parsing, numpy, scipy
if 'electric' in producer.energy:
recipe = self.produce(cls, producer, **kwargs)
recipe.rates['Energy'] = energy
yield recipe
elif 'heat' in producer.energy:
recipe = self.produce(cls, producer, **kwargs)
recipe.rates['Heat'] = energy
yield recipe
elif 'burner' in producer.energy:
for fuel_name in producer.valid_fuel.split('+'):
fuel_name = fuel_name.strip().lower()
fuel = all_items[fuel_name]
fuel_value = parse_power(fuel.fuel_value)
new_kwargs = dict(kwargs)
if self.title:
title = self.title
else:
title = f'{self.resource} ({producer})'
new_kwargs['title'] = f'{title} fueled by {fuel_name}'
recipe = self.produce(cls, producer, **new_kwargs)
recipe.rates[fuel.title] = energy / fuel_value
yield recipe
else:
raise NotImplementedError()
tree_re = re.compile(r'(\d+) .*?\|([^}|]+)\}')
def wood_mining(self) -> Iterable[MiningRecipe]:
miners = tuple(
ManualMiner(tool)
for tool in all_items.values()
if tool.prototype_type == 'mining-tool'
)
for m in self.tree_re.finditer(self.resource.mining_time):
mining_time, source = int(m[1]), m[2]
for miner in miners:
yield self.produce(
MiningRecipe, miner,
mining_hardness=float(self.resource.mining_hardness),
mining_time=mining_time,
title=f'{self.resource} ({miner} from {source})')
The following is multiple choice question (with options) to answer.
Which is a producer? | [
"cloudy mornings",
"vinyl",
"team Alicia",
"strawberries"
] | D | a producer is a source of sugar in an ecosystem |
OpenBookQA | OpenBookQA-4040 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
Jays find nutrition in | [
"mulberries",
"plastic beads",
"philosophy",
"metal blue bells"
] | A | a tree is a source of food for birds in an ecosystem |
OpenBookQA | OpenBookQA-4041 | photons, vision
Title: Dark room lights When I lay down in my room at night it's pretty much completely dark but I observe this strange phenomenon going on.
When I lay down and look at my ceiling I can see my white fluorescent white bulbs and white fan blades but when it's dark I can't. But, as soon as I avert my eyes from the fan and lightbulbs about 1 foot I can see them in the dark but why? If it helps there is a very slight illumination from the street lights. And, also I can't see anything not white on the ceiling.
Why can I see the objects only when I avert my eyes? This is really a biology topic, rather than a physics one.
The light sensing cells in your eyes come in two (or four depending on how you count) types. The cones are color sensitive. The rods are sensitive over almost the whole visible spectrum and offer no color discrimination, but they are considerably more sensitive than the cones.
The rods and cones are not evenly distributed in the eye. Cones are concentrated in the central part of the retina and rods are more common in your peripheral visual region. Which makes your peripheral vision more sensitive to very dim sources than your central vision.
In fact, naked-eye star-gazers learn to look near-but-not-at very dim observing target exactly to take advantage of this effect. But it take a lot of will-power to do at first. You'll find your self having a "Ah-ha!" reaction and then looking right at the target every time you make the trick work. At which point you have to go around again.
The following is multiple choice question (with options) to answer.
What uses eyes to see by sensing light? | [
"trees",
"algae",
"worms",
"elephants"
] | D | eyes are used for seeing by animals by sensing light |
OpenBookQA | OpenBookQA-4042 | algorithm-analysis
Title: Calculating the average waiting time of tasks I have proposed a load balancing algorithm for a group of homogeneous processing devices and now I want to measure the average waiting time to see if my algorithm is successful in decreasing the waiting time. I have considered number of tasks on each device as the load of that device.
Imagine at first there are 54 tasks that is distributed like this between devices:
device1 = 32
device2 = 20
device3 = 2
And after load balancing 15 tasks are transferred from device1 to device3 and these values change to:
device1 = 17
device2 = 20
device3 = 17
Now I want to calculate and compare average waiting time before and after the load balancing, but I'm confused about which tasks to consider.
Should I consider all 54 tasks and measure the waiting time of all these 54 tasks
Or
should I only consider 15 tasks that were transferred and calculate the waiting time of these 15 tasks before and after load balancing? From the two options, the first is the (only) reasonable approach. The second one is absolutely useless; details follow:
If you are trying to minimize the waiting time of the tasks that were shifted, then the best algorithm simply reschedules no tasks at all. The total time of transferred tasks is zero and, thus, optimal. Even if you require at least one task to be transferred, the best algorithm then simply picks the one with the least running time and transfers it to the least loaded queue. In both cases it could hardly be said the algorithm does something useful.
If you are trying to maximize the waiting time of the tasks which were rescheduled, then consider the algorithm which permutates all tasks between the devices. This naturally maximizes said measure and, again, hardly qualifies as a sensible load balancing algorithm.
The following is multiple choice question (with options) to answer.
A crowd-source worker wants to track when a certain task drops. They would | [
"use a notebook",
"randomly play tracks",
"buy expensive sneakers",
"run for miles"
] | A | An example of collecting data is measuring |
OpenBookQA | OpenBookQA-4043 | \begin{align} \dbinom{6}{2} & \longleftrightarrow \dbinom{6}{6-2} \\[8pt] AB & \longleftrightarrow CDEF \\ AC & \longleftrightarrow BDEF \\ AD & \longleftrightarrow BCEF \\ AE & \longleftrightarrow BCDF \\ AF & \longleftrightarrow BCDE \\ BC & \longleftrightarrow ADEF \\ BD & \longleftrightarrow ACEF \\ BE & \longleftrightarrow ACDF \\ BF & \longleftrightarrow ACDE \\ CD & \longleftrightarrow ABEF \\ CE & \longleftrightarrow ABDF \\ CF & \longleftrightarrow ABDE \\ DE & \longleftrightarrow ABCF \\ DF & \longleftrightarrow ABCE \\ EF & \longleftrightarrow ABCD \end{align} There are exactly as many ways to choose $2$ out of $6$ as to choose $6-2$ out of $6$ because each way of choosing $2$ out of $6$ has a corresponding way of choosing $6-2$ out of $6$ and vice-versa.
• NOTE TO FUTURE USERS: This combined with TheSparkThatThought's answer and Ned's comment at the original question will guide you to the way someone must think. Jun 27 '14 at 23:12
Consider a collection of $n$ objects. Choosing $k$ of them to place into a set is equivalent to choosing $n-k$ to leave out.
Edit: Consider a high school dodgeball game with a red team and a blue team. There are $n$ total students, and the blue team has $k$ students. Since every student plays, there are $n-k$ students on the red team.
Because the PE teacher is biased, he lets the blue team pick all of their players first. They have $\binom{n}{k}$ ways to do this. After that, the red team has no choices. They must pick all of the remaining $n-k$ students.
The following is multiple choice question (with options) to answer.
Falcons reside best in | [
"volcanoes",
"Scottish moors",
"tar pits",
"ocean trenches"
] | B | animals live and feed near their habitats |
OpenBookQA | OpenBookQA-4044 | algorithms, graphs, optimization
There is one final component of your problem we have not addressed, i.e., there is a set of books $S_1$ that MUST go into box 1 and a set $S_2$ that MUST go into box 2.
Off the top of my head, I do not see a way to fix this without incorporating a source and sink $s$ and $t$ (for box 1 and 2 respectively). The formulation I've given above is almost sufficient. If $j\in S_1$ (book j MUST go into box 1), make $p_{sj}$ arbitrarily large (much more than $W$). This ensures an arbitrarily large cost will be charged if you try to but a book that must go into box 1 into box 2. Similarly, if $i\in S_2$, make $p_{jt}$ arbitrarily large.
Assuming $S_1$, and $S_2$ are non-empty (that books are already forced into each box), $W$ can be taken as 0 (since a proper partition is enforced by $S_1,S_2$) and $p_{sj}=p_{it}$ for $j\in S_1, i\in S_2$ can be as little as $\sum_{{i,j} \in N:\ i<j} p_{ij}$ (assuming each $p_{ij}\geq 0$).
The following is multiple choice question (with options) to answer.
What might have more closely packed matter | [
"air",
"wood",
"gold",
"water"
] | C | matter is made of molecules |
OpenBookQA | OpenBookQA-4045 | entomology
Title: Constantly wiggling moth pupa - will it emerge soon? Today I found a moth pupa in the soil in my garden in western Sweden. It's about 15 mm long.
I have found similar ones before, but this one is wiggling a lot more, even after I put it down and put a bit of dirt over it. It's been moving for more than an hour now, but less now than in the beginning.
I was hoping to see it emerge, but if it will take more than a day or so, I will probably put it back. So, what I'm wondering is if this wiggling is any indication of how soon it will emerge. Or if there are other ways to tell.
Update: an hour later it has stopped moving. Maybe it was just very disturbed by my presence. I'm keeping it in a jar with soil and a stick for climbing up on, and I'll decide what to do with it tomorrow.
Update: 12 hours later and it seems very still. But I'm letting the question remain since I really want to know if there are any signs to look for.
Final update: After 16 days it had turned almost black, and was still very active when handled.
And after 17 days this moth came out: I posted the same question on tumblr and got an answer:
It depends on the species. This one looks like a Noctuid. I’d give it
two weeks to a month or so. You may be able to see its wings showing
through the darkening pupal case when the time draws near! Just make
sure you give it somewhere to climb up and expand its wings when it
ecloses.
After keeping it until the moth emerged, I now know that wiggliness is not an indication of maturity, but turning dark is.
The following is multiple choice question (with options) to answer.
if an animal skips the pupa stage in its metamorphosis, what does that characterize? | [
"a process of incomplete transition",
"a very passive metamorphosis",
"a true and complete metamorphosis",
"a very aggressive metamorphosis"
] | A | the pupa stage is a stage in the metamorphosis process of some animals |
OpenBookQA | OpenBookQA-4046 | mechanical-engineering, motors, hydraulics, engines
So long story short, does anyone have any ideas how to replicate a DC stepper motor with a gasoline engine (assuming constant low RPM) that does not require any DC motor on its own? Mechanical power can be suddenly applied and cut off with commercially-available electromagnetic clutches. These are commonly used to turn on and off the refrigerant compressor in your car's AC system and to turn on and off the PTO drives in tractors. I do not know if they can turn on and off suddenly enough for your purposes.
The following is multiple choice question (with options) to answer.
which one of these would be an original form of what powers most autos? | [
"a can of water",
"a deposit of crude",
"a large river dam",
"a big oak tree"
] | B | oil is a source of gasoline |
OpenBookQA | OpenBookQA-4047 | optics, reflection, geometry
Title: How to see the image of an object in the mirror from another position? Say I have a large mirror and in front of the mirror, there is an object and I'm standing at a different position in front the mirror. At what position should I look in the mirror so that I can see the object in the mirror?
For example: If I stand at the point $(2,6)$ and object is at $(4,9)$ and the mirror is on the x-axis and has infinite length. What position should I look at to see the object? The basic idea is, you can think of the mirror as a window, when you look through it, you see the symmetric version of your own dimension. If the mirror is on the x-axis, the objects distance to the mirror will be the same on both sides;
if the object is at (4,9), its distance to the mirror is 9 units, meaning it will be 9 units away from the 'window' when you look out. So the objects 'virtual position' will be at (4,-9), that's where you will see it. Similarly you will see yourself at (2, -6).
Notice that this means while the actual object is on the left of your real position, the virtual object is on the right of your virtual position.
Where you need to look on the mirror is now a geometry problem. Draw this system with both the real and virtual points on the coordinate system, then draw a line straight from your real position to the virtual position of the object. Then draw a right triangle with this line being the hypotenuse, and the other side of it connecting to your real position perpendicularly.
What we need to find is where on the x-axis the hypotenuse you drew is passing from, that's the point where you'll look to see the object. To find this point we use the following ratio;
$$
\frac{2}{15} = \frac{d}{6}
$$
The following is multiple choice question (with options) to answer.
What can you see yourself in? | [
"a tar pit",
"a deep cave",
"clear mountain lake",
"an abyss"
] | C | shiny things reflect light |
OpenBookQA | OpenBookQA-4048 | entomology, ethology, habitat
Title: Preferred criteria for new bee colony location As a human I want a house with a roof, indoor plumbing, bug free, and make my wife happy. I don't want to drive too far to work, and it has to be well-suited for offspring.
What are the criteria that define a "good spot" for a new location for honey bees. I'm sure it involves water, shade, access to nectar, and defensibility, but I don't know any of the details.
Has anyone ever made measures of this? Beekeepers? Apiologists? What are the things bees think are important, and what values of those do they think are "best"? According to Thomas Seeley, in his book, Honeybee Democracy, he gives the following as important criteria for honeybees when selecting a nest site when a bee colony moves to swarm:
Larger volume (the minimum nesting capacity was found to be around 14 liters with more preference to nests with a capacity of approximately 30 to less than 100 liters)
Relatively small entrance (10 to 30 centimeters squared)
Nest with the entrance located near the floor of a tree cavity
Direction of the nest entrance (south facing for thermoregulation during the winter)
Nest height (preference given to higher nests for colony defense)
Remnants of previous honeycombs (saves work and energy in building the nest structure)
Interestingly enough, bees did not necessarily display a preference for the shape of the entrance, the shape of the nest, the draftiness or dryness of the nest cavity (they are able to plug and waterproof nests).
Flower/nectar/food availability is not necessarily a direct factor as this changes quite frequently throughout the seasons and honeybees are not able to leave their honey stores (which are necessary to sustain the colony throughout the winter) or take them with them every time the colony has trouble finding food. Honeybees have a complex and efficient system for optimized location and sharing of food sources, therefore distance is not as large a factor.
The following is multiple choice question (with options) to answer.
Where is a mama bear likely to find food? | [
"on top of the highest trees",
"in the deepest mines",
"in the inside of a felled oak",
"at the bottom of the lake"
] | C | bears eat insects |
OpenBookQA | OpenBookQA-4049 | Kudos [?]: 4 [2] , given: 0
Re: Good set of PS 2 [#permalink] 19 Oct 2009, 08:02
2
KUDOS
Bunuel wrote:
4. A contractor estimated that his 10-man crew could complete the construction in 110 days if there was no rain. (Assume the crew does not work on any rainy day and rain is the only factor that can deter the crew from working). However, on the 61-st day, after 5 days of rain, he hired 6 more people and finished the project early. If the job was done in 100 days, how many days after day 60 had rain?
(A) 4
(B) 5
(C) 6
(D) 7
(E) 8
This one was solved incorrectly:
Days to finish the job for 10 people 110 days.
On the 61-st day, after 5 days of rain --> 5 days was rain, 55 days they worked, thus completed 1/2 of the job, 1/2 is left (55 days of work for 10 people).
Then 6 more people was hired --> speed of construction increased by 1.6, days needed to finish 55/1.6=34.375, BUT after they were hired job was done in 100-60=40 days --> so 5 days rained. They needed MORE than 34 days to finish the job, so if it rained for 6 days they wouldn't be able to finish the job in 100(40) days.
I solved in a more easier way I think:
1) 10 man 110 days --> need for 1100 man.days
2) 55 days with 10 men --> 550 man.days
3) 40 days with 16 men --> 640 man.days
--> total man.days equals 1190 vs need for 1100 --> days of rain equals 90/16 max --> 5.625 --> rounded to 5
Senior Manager
Joined: 31 Aug 2009
Posts: 420
Location: Sydney, Australia
Followers: 6
Kudos [?]: 165 [1] , given: 20
The following is multiple choice question (with options) to answer.
You can work longer when | [
"Autumn changes to Winter",
"spring changes to summer",
"tree leaves start falling",
"the first snow starts falling"
] | B | when the season changes , the amount of daylight will change |
OpenBookQA | OpenBookQA-4050 | everyday-chemistry
Vinegar is used by many DIY people, but it is not a popular commercial product because it smells kind of bad, it's not very effective, and if it is mixed with bleach (WARNING) it can cause a serious health hazard. Also, 5% acetic acid is not extremely germicidal (it will work to kill bacteria in food after a few days); many spores will survive for hours in acetic acid. Vinegar is most effective against non-spore forming (gram negative) bacteria- which are often the more nasty kinds of bacteria (Salmonella, E. coli, Serratia, Pseudomona, etc.)... but it's less effective against spore forming (gram positive) bacteria (Candida, Bacillus, Streptococcus, Micrococcus, etc.). Again, it is an effective preservative in food... as is 5% ethanol (ie., beer). 50% acetic acid is much more effective and it works faster... as does 50% ethanol. pH is a factor, so vinegar is a bit more effective than ethanol, but in general, a high pH is much more effective than a low pH. So, ammonia or lye solutions are more effective than organic acids.
70% isopropanol and 60% ethanol are a common hand and wound disinfectants. They are fairly antimicrobial and antiviral, but again, spores (and other gram positive bacteria) can survive in dilute alcohols (for a little while).
The following is multiple choice question (with options) to answer.
Which is likely the least helpful for the good bacteria that help your body? | [
"hot showers",
"eating well",
"keeping hydrated",
"using probiotics"
] | A | good bacteria grow on the skin |
OpenBookQA | OpenBookQA-4051 | zoology, ecology
Giraffes' this is an energy saving feature. Giraffes don't need to use muscles to hold their neck. They just use when flexing their necks down, when drinking water etc.
According to Wikipedia, for an alternative hypothesis Ouranosaurus have a hump. (Other hypothesis is display sail or termoregulation sail of course. Also spinosaurus have this kind of alternative hypotesis but this hypothesis not accepted much as sail. and spinosaurus' spine different from bisons. Bison spines concentrating at shoulder but spinosaurs' not at the shoulder. You can find spinosaurus info from this page.)
The following is multiple choice question (with options) to answer.
Alligators have a | [
"carrot",
"glasses",
"scarf",
"wide nose"
] | D | alligators eat fish |
OpenBookQA | OpenBookQA-4052 | light, jupiter, natural-satellites, life, europa
Title: Is there enough light to grow plants in the ocean of Europa? What is the underwater temperature of Europa?
I know Jupiter emits infrared light but does it emit any light able to support plant life of any type on near by Moons? Can under water volcanic activity of Europa produce enough light to support plant life? The surface of Europa gets some sunlight direct from the sun and some long wave radiation from Jupiter so it's not in darkness. It's also in Jupiter's radiation belt so it gets hit with high energy charged particles and the surface of Europa, despite being bombarded by particles is still a vacuum. The surface of Europa is a terrible place to look for life, with the exception being that the liquid ocean of Europa explodes onto it's surface regularly, so evidence of life, if it exists, may well be found on the surface, but it's unlikely that anything can live there for long. It's very inhospitable.
The inside of Europa is more interesting. That's why Neil deGrass Tyson says he wants to go "ice fishing on Europa" to see what "licks the camera" and if we find life there we'll "Call them Europeans" . . . funny comments aside, the inside of Europa is probably dark, outside of some infra-red rays due to temperature. Photosynthesis doesn't work well in darkness and with just long wave light, though maybe it's possible, it wouldn't nearly as much growth due to far lower energy levels.
As noted in the answer to your other question, if there is life in Europa's ocean, it's more likely to be something like chemotrophs.
What makes Europa interesting is the energy it gets from tidal forces being stretched between Jupiter and Ganymede, so it gets a regular influx of heat and perhaps internal volcanism, so it may have undersea vents similar to our oceans. The energy influx and possibility of underwater volcanoes makes it more interesting than most other moons or dwarf planets.
If life is found in Europa's oceans, even if it's very primitive life by most standards, it would still be a very cool discovery because it could tell us something about how life starts and that's a big unknown right now. The discovery of life outside the Earth would be a very big story.
The following is multiple choice question (with options) to answer.
which of these is the primary source of light of our planet? | [
"the cluster of Orion stars",
"the moon which orbits earth",
"the closest star to us",
"the meteorites flying by"
] | C | the sun is a source of light called sunlight |
OpenBookQA | OpenBookQA-4053 | materials, plastics
Title: Which material to use for athletic accessories? I'm looking for some guidance in selecting the right material for dance shoes heels and women's self-defense accessories.
I'm looking for a material that 1) has a superb strength-to-weight ratio, can withstand punishing and frequent impact, and very light (like plastic).
The part for the shoe will be very, very slender (stiletto heel), but will have to be able to endure hours of jumping, sliding, stomping, spinning, and skidding dancers… is compression strength the right term?
2) The material must also be safe to use as jewelry, so nothing toxic. Also, I am looking for something that tends to snap, rather than shatter, when it fails under pressure.
3) Lastly, it would be great if this material can be 3D printed, although that is not a must.
An inexpensive material would be ideal, of course, but I am open to learning about a fuller range of materials, including the more expensive ones. I am willing to consider a higher priced material if it will offer substantial value to the accessories in terms of strength, quality, and safety. For plastics, my first instinct for the first two properties would be a polycarbonate plastic. Polycarbonates are known to be very strong plastics (tensile strength up to ~70 MPa) and deform without breaking under many conditions, which is why they're commonly used in things like safety glasses and bullet-resistant glass. It also looks very interesting as it's quite optically clear. PC is 3D printable, I've seen a few people using it in hobby printers (http://www.protoparadigm.com/blog/2011/12/printing-polycarbonate/) and in very high end StrataSys printers, but it's not a super common material so it might take some experimenting.
Another option is a nylon. There are a number of different types available and many have similar properties to polycarbonates (minus the optical clarity). Nylons seem to be a bit more popular for 3D printing and I've heard good things about the Taulman filaments.
The following is multiple choice question (with options) to answer.
which of these would make a better material for an electronic device component? | [
"a brown copper panel",
"a string of cotton",
"a coil of rubber",
"a strip of plastic"
] | A | wiring requires an electrical conductor |
OpenBookQA | OpenBookQA-4054 | forces, water, surface-tension
Now, if we suddenly boost up this adhesion a billion times stronger (limit: imagination) from what is the real and cohesion stays same, then it's gonna suck. Literally. Everything the water or any liquid comes to contact with, it will immediately start to evenly spread out, clothing every nooks and cranny on that surface of that object. It'd be much like when we spill water on the floor. But now it'd be happening EVERYWHERE, on the sides and on the roofs. The rivers, lakes and oceans start allowing a layer of water to swallow everything up, and a carpet of water will cover the world. Trees and plants burst as there is an immense rush of water inside them. The large droplets of water we adored will never form, a droplet release in the air will torn into tiny minuscule droplets, that we can't see. Maybe into water vapor. And Life? I wonder... ;)
Hope that helped. Went a little overboard. :D
The following is multiple choice question (with options) to answer.
If all the water in the Atlantic ocean evaporated, the Atlantic ocean will | [
"get bigger",
"become a lake",
"cease to exist",
"get smaller"
] | C | if a body of water loses all water then that body of water does not exist any more |
OpenBookQA | OpenBookQA-4055 | • $P_2$ will fly $\big[1-(d+r+y)\big]$ distance away from the airport in the counter-clockwise direction to meet up with $P_3$.
• At this point, $P_2$ will donate $z$ fuel to $P_3$.
• $P_2$ and $P_3$ will then both fly back $z$ distance, arriving at a distance of $1-d-r-y-z$ from the airport with no fuel.
• After refuelling at the airport, $P_1$ will fly the distance towards $P_2$ and $P_3$ and refund each of them for that much fuel. All three planes will then head back to the airport together.
From this, we must have
• $0 \leqslant s\leqslant d/3$: $P_1$ can fly $s$ distance forward and backwards, and refund $P_2$ for $s$ distance
• $z\geqslant 0$: cannot donate negative fuel
• $2x + 1-d-r-y \leqslant d+r+y$: $P_3$ must not run out of fuel before $P_2$ can reach it again
• $1-d-r-y - z \leqslant d/4$: $P_1$ can reach $P_2$ and $P_3$, refund them both, and the three of them will have enough fuel to head back to the airport
• $2x + 2s + 1-d-r-y - z\leqslant d+r+y + z$: $P_2$ and $P_3$ must not run out of fuel before $P_1$ can reach them again
Putting these together:
The following is multiple choice question (with options) to answer.
A plane travels through the air surrounding a | [
"planet",
"black hole",
"submarine",
"cave"
] | A | a plane travels through the atmosphere |
OpenBookQA | OpenBookQA-4056 | home-experiment, oxidation-state
Title: the perfect campfire As far as chemistry goes, there are laws or observations that can be useful to determine the perfect shape and disposition of the wood in a campfire ?
For example what chemistry says about the 2 most popular "shapes"
teepee
log cabin
or even other variations such as the swedish stove ( 1 log with the top splitted in multiple segments )
The properties that I'm looking for:
- easy to start
- long lasting
The properties that I would like to have but I can discard:
- significant heat generation From many years as a trained firefighter, I can tell you that there is certainly science involved. There are a number of very heavy calculations for calculating things like solid combustible burn time and heat release rates for combustible materials, which might possibly be useful to predict the perfect shape, fuel size and arrangement for a campfire, but are probably well beyond the scope of producing the perfect sausage sizzle. However, a number of key factors that influence fire behaviour, and which must be considered in building the best campfire include:
The following is multiple choice question (with options) to answer.
What is most likely to set the woods alight? | [
"lightning bugs",
"a flood",
"a storm",
"hot red peppers"
] | C | wildfire is when a forest catches fire |
OpenBookQA | OpenBookQA-4057 | geology, glaciology, geomorphology, ice-age, glaciation
Title: How old are Chile's fjords? Do we have any knowledge about the age of Chile's fjords, more specifically, those found near the Northern Patagonian Ice Field?
Is it reasonable to conclude that they were formed in Quaternary given the fact that there exist glaciers there at this point in time? The Quaternary is definitely a good guess. But it is difficult to answer your question because the "age of a fjord" is a rather ambiguous concept.
Also, I'll asume you are interested in the bedrock topography associated to the fjords, and not only the sea inlets (as in that case they would have formed very recently, just when the glaciers receded enough to allow the ocean water to take their place). With that said let's try to answer the question:
The fjords of western Patagonia are a feature created by the Pleistocene glaciations, therefore you can definitely say that the fjords as a feature of the landscape were formed during the Quaternary. However, they are in constant evolution, so you can arguably also say that the fjords as you see them today, were formed today.
Glacier erosion rates in Patagonia range roughly from a few tenths of millimeters to a few centimeters per year. Faster rates probably happening at the edges of the ice sheets were glacier basal sliding velocities are higher. Long term averages (~10 ka) are probably between 0.5 mm/yr and 1 mm/yr, meaning that in the 2.6 Ma of the Quaternary you would erode just about one to two kilometers. As some fjords can be much deeper than that (when measured from the mountain tops), it is clear that the fjords as a geographical feature are not in steady state, and they are now more dramatic than ever throughout the Quaternary.
The following is multiple choice question (with options) to answer.
Glaciers have | [
"magic",
"feelings",
"emotions",
"slow, hidden rivers"
] | D | a glacier is made of ice |
OpenBookQA | OpenBookQA-4058 | microcontroller
Title: Beaglebone Black power draw What is the minimum amount of power that a beaglebone needs to start up? This would be with no peripherals attached besides host usb. The getting started guide claims that it can run off of a computer's usb power, but makes no mention of how many amps are actually needed. I saw a mention of older kernels limiting current draw to .5 amps when working off of usb, although that was all I could find.
Could one start a BeagleBone Black off of .3 amps? If not, how many? If the getting started guide claims you can run it of a computers USB port, it will work at about .5 amps. A normal computer power supply limits the current to a USB port to .5 amps. Doing some research on the Beaglebone Black's site http://beagleboard.org/Support/FAQ, I found this:
When powered up over USB, the regulators are somewhat limited in what they can supply the system. Power over USB is sufficient as long as the software and system running perform some management to keep it under the USB current limit threshold.
and
The recommended supply current is at least 1.2A (or 6W), but at least 2A (or 10W) is recommended if you are going to connect up anything over the USB. The actual power consumption will vary greatly with changes on the USB load.
So it seems like the .5 amps from the computers USB port, is about as low as it gets.
The following is multiple choice question (with options) to answer.
Which requires an outlet? | [
"cold iced tea",
"usb tape player",
"frothy beer",
"blowing leaves"
] | B | electricity is made of moving charged particles |
OpenBookQA | OpenBookQA-4059 | telescope, newtonian-telescope
Bottom line: don't buy a refractor because you "want to watch planets". But do buy a refractor if simplicity of use and the low maintenance are very important to you (and you don't care much about price).
A decent refractor on an excellent mount can do pretty good astrophotography. More on that below.
CATADIOPTRICS (CASSEGRAIN, MAKSUTOV, DALL-KIRKHAM, RITCHIE-CHRETIEN)
Broadly speaking, these are for astrophotography (not always, but usually). But can you do visual astronomy with them? Sure. It's just that it's easier to optimize them for photo, with this design.
Usually, they come installed on a motorized mount. All but the very cheapest ones have a computer on-board; you just punch the name of the object into the remote control, and the scope will turn around automatically to face the object. Sounds cool, right?
Well, I am going to say something a little controversial here: this is not a good place to start.
First off, astrophotography has an extremely steep learning curve. It's very easy to take a little blurry photo of Jupiter that will impress nobody. It's very hard to take a great, high resolution photo like these:
http://www.acquerra.com.au/astro/
The skills and knowledge required to take that kind of photos are more easily acquired by doing purely visual astronomy, on a dob or whatever, for a couple years or more. Also, the equipment required for that sort of stunt costs many thousands of dollars - your cheap little Cassegrain cannot do it.
So why buy a small Cass? Well, if you have an overwhelming interest in astrophoto, and are prepared to deal with the difficult learning, then go ahead. But realize that the first images are not going to be very impressive, and the motorized mount will not teach you some valuable skills that you would acquire more easily pushing a dob around and keeping your eye plugged into the ocular for a while. Also, money spent on the motorized mount is money NOT spent on aperture, and the aperture is so important for overall performance.
The following is multiple choice question (with options) to answer.
On what product might you find a reflector? | [
"Xbox",
"Toyota",
"Samsung",
"Apple"
] | B | a reflector is used to reflect light especially on vehicles |
OpenBookQA | OpenBookQA-4060 | safety, gas
Title: Rotten Egg Gas Smell Background context for question
When I was young, we'd go fishing. And Dad would put a camper on the back of the truck. One time we came back in after fishing and the camper smelled like rotten eggs. He used that as an opportunity to teach us how some gases are tasteless/odorless. And as a result that sort of rotten egg smell is added as a safety measure.
Question:
My question is this: What are those gases that are odorless that then have that rotten egg smell added to them? Rotten eggs happen much less frequently than 50-60 years ago because of better hen-consumer refrigeration. Most people today have not had the pleasure of smelling them. H2S and low molecular weight mercaptans [AKA thiols] have distinct more or less unpleasant odors tho at low concentrations they can smell sweet, and we can develop tolerances to many at higher concentrations when they can be deadly. H2S is supposedly the active ingredient in rotten eggs; Methylsulfide CH3SH the active gas in human feces, and thioglycolic acid in eau de skunk.
Manufactured gas, no longer used, was a mix of H2 and CO and is toxic. It was flavored with mercaptan at rather high levels; smelling gas then was almost a death sentence, we were trained to open windows and leave immediately. There was also the explosion hazard. Manufactured gas was replaced by "natural", really fossil fuel, gas that is mostly methane CH4. Methane is odorless, not toxic, but it can be soporific, and it can explode. A warning is still necessary tho it seems to me the odorant is now less noxious and less intense than before [It could be my sense of smell has waned.]. It is to protect from explosion, again evacuate and ventilate. Odorants are added to propane and LPG, I do not know about hydrogen. Perfumes are added to many products to overcome odors or enhance odors and Bitrex is added to some drugs to make them less palatable so it works both ways.
The following is multiple choice question (with options) to answer.
a couple sits on a meadow enjoying a nice picnic, when something runs by with a terrible smell. what could it be? | [
"a raccoon wandering the meadows",
"a person with a great cologne",
"a little skunk going about its business",
"a scarecrow come to life"
] | C | a skunk produces a bad odor |
OpenBookQA | OpenBookQA-4061 | plant-physiology
Title: Would a plant survive if it was watered using hard-water? Hard water is water with high mineral/salt content. I'm told that a potted plant watered with a salt solution dries out sooner or later. Is this true?
If so, would a plant survive if watered using hard-water? It would depend on the content of the hard-water. If the water contained heavier metals like lead or radioactive elements like tritium (Hydrogen-3), the plant would most likely die. Most land plants cannot survive when watered with massive amounts of salt water as the salt would absorb the water from the leaves.
The following is multiple choice question (with options) to answer.
An plant that requires lots of watering would do better in | [
"craters on Earth's moon",
"a sandy, barren desert",
"a lush elm-filled area",
"a large expanse of frozen tundra"
] | C | a forest environment receives more rainfall than a desert |
OpenBookQA | OpenBookQA-4062 | anatomy, ichthyology
Title: Is the fin of ray-finned fish live tissue or more similar to scales? In ray-finned fishes, are what exactly are the fins made of? Is it modified skin, dead tissue like scale or nail on humans, or something completely different? Can the fin heal? In teleosts, the fin skeleton is made of structures called lepidotrichia and actinotrichia, whereas homologue structures called ceratotrichia are found in the fins of the chondrichties. These are covered by living skin.
Lepidotrichia are calcified, segmented and branched bone-like rays that extend along the whole length of the fin, shaping it. Actinotrichia are mostly made of collagen and are found at the distal end of the ray, where they provide flexible support to the fin edge1.
Fins are able to regenerate, and this capability has been studied in a few different teleosts2,3,4.
References:
The following is multiple choice question (with options) to answer.
In some fish, their fins may be used for | [
"back pats",
"evenness",
"high-fives",
"magical spells"
] | B | large fins can be used to move quickly through water |
OpenBookQA | OpenBookQA-4063 | species-identification
Title: Trying to identify the tree in this picture. Shot from the Nepenthe restaurant, Big Sur, California I'm trying to identify the tree in this picture. This was shot from the Nepenthe restaurant, Big Sur, California.
Any help is appreciated!
Thanks,
Robert It's difficult to make out the leaves in the photo, but the tree in the foreground appears to be a coast live oak (Quercus agrifolia). The tree has hairy lichen growing on its branches.
The following is multiple choice question (with options) to answer.
A dead giant sequoia | [
"turns into mistletoe",
"flies away",
"drops pine needles",
"falls down"
] | D | if a tree falls then that tree is dead |
OpenBookQA | OpenBookQA-4064 | hearing, senses
Title: Can somebody be deaf to voices of some people only? The voice of females is generally of high frequency, while that of males is generally of low frequency.
Also, as we age, we gradually keep losing the ability of hearing sounds of high frequencies.
So, can such a situation occur when a person is not able to hear voices of females, or maybe of certain people, while he can hear the voices of other people? I tried searching about it, but found nothing. Although you loose the high frequencies in your hearing with age (20kHz and below), this is highly unlikely. The frequency spectrum of our voice is pretty much limited, which is also shown by the fact the for normal telephone, the spectrum transmitted is located between 300 and 3400Hz and the spectrum band between 300 and 3000Hz is named the "voice band". See here for some details.
According to reference 1 the "voice fundamental frequency" for men is between 85 and 180Hz (depending on the reference) and for women between 165 and 255Hz. These frequencies are close enough together to rule out specific hearing of male or female voices. Furthermore the frequencies even overlap.
What happens in age-related pathological hearing loss (also termed Presbycusis) is that voices generally get muffled due to losses in the spectrum and hearing intensity. See the Wikipedia link and also reference 2 for more details.
Reference:
The frequency range of the voice fundamental in the speech of male
and female adults
Presbycusis
The following is multiple choice question (with options) to answer.
Who can hear sounds? | [
"boulders",
"giraffes",
"rocks",
"stone statues"
] | B | when sound reaches the ear , that sound can be heard |
OpenBookQA | OpenBookQA-4065 | quantum-mechanics, hilbert-space, observers, superposition, schroedingers-cat
Title: Schrödinger's cat question what would happen if a CC Camera or videocorder is put along with Schrödinger's cat inside the sealed box? Would it influence the outcome? I assume that the camera in your thought experiment is not a gate out the box i.e. it also doesn't interact with external world until you open the box.
The crucial point about the Schrödinger's cat thought experiment is that it's not the cat who is in the superposition of the macroscopically distinct states. As a matter of fact you can't assign a pure quantum state to the cat alone, only to the whole interior of the box. So what you get is basically a bigger Schrödinger's cat - the cat, the detector, the air, your camera should all be considered a "Cat" that is in the quantum superposition.
If you ask whether the addition of the camera destroys the quantum superposition of the macroscopically distinct states of the interior the answer is no.
However you can ask the following question. If you open the box and measure the interior what is the probability that the cat is found to be dead whereas the recording of the camera shows it to be alive?
If your cat and camera actually consist of several atoms this probability actually may be quite significant. However for macroscopic system for those few degrees of freedom you're actually measure the process of the quantum decoherence happens. In that case this probability may actually be so small that it should be considered zero for all practical purposes.
So while for the external observer the whole interior should be considered to be in the very nonclassical state until you open the box, the camera recording extracted in the end will show the approximately classical behavior. The "collapse" happens for the camera, not for you.
If instead the camera is constantly translating to you through some little hole in the box (and this is the only interaction of the interior with the external) then you will destroy the superposition. To what extent is actually a difficult question to answer without details of your communication with the camera. If it is very weak you may get too little bits and too much noise to distinguish dead cat from alive with high degree of certainty and that will determine how much the superposition inside decoheres.
The following is multiple choice question (with options) to answer.
What would a polecat leave in a chair? | [
"poles",
"poetry",
"hair",
"dusk"
] | C | shedding is when an animal loses hair |
OpenBookQA | OpenBookQA-4066 | food, nutrition, energy-metabolism
Title: What are the bare minimum nutrients required to survive as a human? I am trying to determine the bare minimum nutritional requirements to survive as a human, ignoring energy (caloric) requirements. Another way to ask this question is: What elements can humans not live without? I am not inquiring solely about what nutrients are needed, but also their approximate amounts.
Imagine pills that a person can take that covers all their base nutritional needs and that after taking this pill the person can eat whatever they want to meet their caloric requirements. Hypothetically, this pill could have some amount (how much?) fat, carbohydrates, protein, fiber, minerals, and vitamins, and the person could subsequently eat any other food to meet their caloric requirements knowing their nutritional needs would already be otherwise met. Lets ignore the possibility of the person suffering from health issues due to eating too much of any specific food to meet their caloric requirements (e.g., taking the magic pills and then eating only butter).
A person in this situation could think "Ok I've got most of my bases covered, now I just need to ingest another 1000 calories of (almost) anything I want).
What nutrients are absolutely necessary for humans to survive indefinitely, and how much of these nutrients are required?
I am hoping for a complete list with approximate amounts (e.g., 20g fat, 20g carbohydrates, 1mg Vitamin X, .05mg Vitamin Y, 10mg mineral X). Essential nutrients include (NutrientsReview):
Water
9 amino acids: histidine, isoleucine, leucine, lysine, methionine,
phenylalanine, tryptophan, threonine, valine
2 fatty acids (alpha linolenic and linoleic acid)
Vitamins: A, B1, B2, B3, B5, B6, folic acid, biotin, B12, C,
D, E and K (and choline, which is considered a vitamin-like substance)
Minerals: calcium, chromium, chloride, copper, iodine, iron,
manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc
The following is multiple choice question (with options) to answer.
What requires nutrients for survival? | [
"sand",
"plastic",
"metal",
"an anaconda"
] | D | an animal requires nutrients for survival |
OpenBookQA | OpenBookQA-4067 | forces, free-fall, scaling
Assuming the last assumption is correct, how are assumptions 2 and 3 related? Is there anything I missed?
Overall, which person can withstand falls from greater heights: a lighter one, or a heavier one? It is difficult to determine which will fare better.
Small mammals can survive a fall from arbitrary distances. Here's one article I found talking about cats. A chief contributor to small mammals' survival is that they have a lower terminal velocity due to the way wind resistance scales. Wind resistance scales with the area of the animal, while weight scales with the volume, so large animals fall faster because they have a higher volume-surface area ration. On a long fall (hundreds of times the animal's body length), body size influences impact velocity
Even without this effect, small animals may have an advantage. In humans, we can study the statistics of plane crash survivors. According to Wikipedia "Since 1970, two-thirds of lone survivors of airline crashes have been children or flight crew." Children make up a small percentage of passengers, so it follows they have a better chance of surviving. It's no great leap to attribute this to their body size. However, a BBC news story has an expert saying there is no physiological advantage to being a child when it comes to surviving a plane crash.
I have occasionally seen this sort of question addressed with dimensional analysis, but the difficulty is that it's difficult to pin down what you want to try to scale. The peak force or pressure, the energy dissipated per unit mass, the peak power dissipation per unit mass?
Here's an example argument:
If we assume the two people are impacting at the same speed, they need to dissipate the same amount of energy per unit mass. Assume that people can dissipate a certain amount of energy per unit mass in a given time without harm. Then whoever can make the impact last for a longer time will fare better. A taller person can bend their legs through a longer distance, and therefore can make the impact take a longer time, and therefore can fare better.
However, the assumptions in this argument would need to be verified before we can take it very seriously.
Here's another argument:
The following is multiple choice question (with options) to answer.
which of these would get bigger and recover from injuries better? | [
"a child who eats thrice a day",
"a malnourished little child",
"a child who gets insufficient diet",
"a child who eats six times a week"
] | A | an animal requires nutrients to grow and heal |
OpenBookQA | OpenBookQA-4068 | newtonian-mechanics, energy-conservation, momentum, conservation-laws
So the answer is that regardless of the current motion of $M$ it is always possible to shoot $m$ at $M$ such that it transfers all its kinetic energy to $M$ and thus the maximum amount is 100%.
The following is multiple choice question (with options) to answer.
What will, for all intents and purposes, never run out? | [
"gasoline",
"sunlight",
"coal",
"natural gas"
] | B | a renewable resource can be replaced |
OpenBookQA | OpenBookQA-4069 | human-biology, biochemistry
Title: Pasteurization and Bioavailability of Antioxidants in Beet Juice What are the effects of pasteurization on the antioxidants found in beet juice ? Does the process render most of the beneficial nutrients (betaine) useless and make them unable for the body to process as efficiently as it would with raw beet juice? Also, does the pasteurization process do this to most fruit and vegetable juices ? I appreciate any insight, I've seen a lot of conflicting reports and am curious of anyones thoughts. Thank you So, when they subjected "ready to drink" beetroot juice to thermal pasteurization, they found the betacyanin and betaxanthin (our major antioxidants, and pigment molecules) content to be 39.9 and 42.28% degraded, respectively (1). Their conclusion was as follows:
Standardization of process condition and
quality degradation of beetroot juice due to thermal
pasteurization was studied. The standardized T2
batch
with total heating time (fh) of 720 s thermal in-pack
pasteurization leads to the minimal degradation of
color, betalain content (Betacyanin and Betaxanthin),
antioxidant activity and complete inactivation of
micro flora of beetroot juice. The color, betalain
content (Betacyanin and Betaxanthin) antioxidant
activity and sensory of the beetroot juice was
significantly (p < 0.05) reduced during 180 days
ambient (27-30°C) storage, but still the quality of the
juice was adequate upto 180 days. We concluded that
thermal pasteurization of 96 °C for a total heating time
(fh) of 720 seconds with P-values of 11.16 would be
a good method to produce microbiologically stable
beetroot juice with the retention of quality attributes.
So our goal is to get a juice that retains as many "good" attributes as possible, while producing a product that isn't going to get anyone a foodborne illness. As for the net effect of pasteurization on fruit juice in general, im still coming to a conclusion there. The process shouldn't render too much of the fruit/vegetable ineffective, though I'd still expect some degradation either in storage or processing.
The following is multiple choice question (with options) to answer.
Pasteurization kills | [
"mammary glands",
"illness causing agents",
"bottles",
"women"
] | B | pasteurization reduces the amount of bacteria in milk |
OpenBookQA | OpenBookQA-4070 | human-biology, neuroscience, brain, endocrinology, sleep
Title: Is it possible for a human to wake up in a wrong way? There's an old folk saying that goes like "He got out of bed on a wrong foot" - to indicate that the person's day is going poorly because of the way that person woke up.
Is it is possible for a human to disrupt the awakening process, causing negative cognitive side effects for the rest of the day? If so, how long does it take to restore normal cognition?
There's this related question that I asked - if different parts of a human brain can be asleep independently of each other? This question is a variation on that one, and specifically deals with the process of awakening or activating brain regions in the morning.
I'm aware of the concept of "Sleep inertia". However, it does not seem to be the phenomenon in question, as sleep inertia is frequently mentioned in the context of napping. (where napping over a certain time leads to sleep inertia). Additionally, sleep inertia has been described in terms of decline of motor activity, and not as cognitive side effects lasting for a whole day.
From personal experience, it seems that I'm doing best if I get out of bed immediately following a natural awakening, even if it is rather early, as opposed to snoozing for another 30-40 minutes. I did a quick search and found some research in this area. Sleep inertia is the technical term for feeling groggy for a while after waking up.
In a review article by Patricia Tassi, Alain Muzet (Sleep inertia. Sleep Medicine Reviews. Volume 4, Issue 4, August 2000, Pages 341–353), they define sleep inertia as
Sleep inertia is a transitional state of lowered arousal occurring immediately after awakening from sleep and producing a temporary decrement in subsequent performance.
and also says,
Depending on the studies, it [sleep inertia] can last from 1 min to 4 h. However, in the absence of major sleep deprivation, the duration of sleep inertia rarely exceeds 30 min.
Same article reviews several studies (first report in 1964) on sleep inertia relating to sleep stages:
Abrupt awakening during a slow wave sleep (SWS) episode produces more sleep inertia than awakening in stage 1 or 2, REM sleep being intermediate.
The following is multiple choice question (with options) to answer.
Insomniacs are less healthy than other people because they | [
"are in space",
"rarely slumber",
"sleep too much",
"fly away"
] | B | a human requires rest to be healthy |
OpenBookQA | OpenBookQA-4071 | immunology, sleep, immunosuppression
Title: Is the immune system suppressed during sleep? Of course we have heard that during stress our immune system is suppressed. This leads me to wonder, does the immune system get suppressed when we are sleeping and why? During both these conditions the body might need to save energy for other biochemical processes, so I wouldn't be surprised that the immune system is suppressed while a person is asleep. During stress glucocorticoids, which are steroid hormones produced by adrenal glands (such as cortisol and corticosterone), are released into the blood-stream. These hormones have anti-inflammatory effects. You may say that they suppress the immune system.
The circadian rhythm, which controls the sleep-wake cycle, also controls glucocorticoid secretion, thereby reinforcing the sleep-wake responses [1]. Sleep deprivation is a form of stress and it causes an elevation in the levels of glucocorticoids. The effect of sleep deprivation could be replicated by adrenectomy (surgical removal of adrenal glands); there is a transcriptional downregulation of several neuroprotective genes [2]. Via glucocorticoid mediated signalling, sleep deprivation also results in inhibition of adult neurogenesis in the hippocampus [3].
Another study says that cytokine (TNFα and IL6) secretion by immune-system cells, are inherently affected by circadian rhythm via a glucocorticoid independent mechanism [4].
Overall, sleep is inversely correlated with reduced inflammation because both the processes are under the control of the circadian clock. Sleep deprivation, as a form of stress, is also correlated with glucocorticoid secretion. It should be understood that sleep doesn't necessarily inhibit glucocorticoid secretion and it would be incorrect to say that reduced inflammatory effects are because of sleep.
The following is multiple choice question (with options) to answer.
More sleep leads to | [
"worst health",
"restlessness",
"insomnia",
"sense of well-being"
] | D | a human requires rest to be healthy |
OpenBookQA | OpenBookQA-4072 | only balances, deposits and withdrawals. Pollen is one of the most common allergens in the United States. 2% and specificity of 94. Then the only non-zero values of ǫijk are those with j,k= 2,3 or j,k= 3,2. [email protected] The annual rate of growth of Ontario’s population is projected to ease gradually from 1. Duke Energy today announced the completion and operation of its new 74. Give results in atomic units. If is then measured and then again, show that the probability of obtaining a second time is. For a long time it was thought that the ear responded logarithmically to sound intensity, i. Because the Hamiltonian, like most operators in quantum mechanics, is a Hermitian operator,. You too can get an idea of how much pawn shops pay you if you’re planning on selling or pawning with a pawn shop. 158), in matrix form, is H -yBoS: The eigenstates of H are the same as those of S With energy E+ — -(vBoh)/2,. The corresponding density matrix operator is given by,. Jaffe 2003 1 Introduction We have spent the first part of 8. Calculate the expectation values of potential and kinetic energies for the 1s state of of a hydrogenlike atom. Hamilton earns approximately $500,000 weekly on Broadway and is expected to surpass$1 billion in sales. Property values in Franklin County are expected to rise by double digits when results from a reappraisal are finalized this year, the Franklin County auditor's office said. Hamilton, New Zealand. Various trees, grasses and weeds create pollen, which can cause hay fever, irritate your eyes and skin. In addition, the risk-free rate must be set (along with. Let the nucleus lie at the origin of our coordinate system, and let the position vectors of the two electrons be and , respectively. Hamilton’s Propane is a family-owned-and-operated propane business, with three locations servicing 17 counties in Lower Michigan. $$I want to know if I set this up properly. The expected value of is a weighted average of the values that can take on. How to calculate expectation values of position and momentum - Real Chemistry - Duration: 10:47. --(Business Wire)--Alliance Resource Partners, L. Optimism definition is - a doctrine
The following is multiple choice question (with options) to answer.
A coal miner would is most likely to get | [
"wet",
"dirty",
"sunburned",
"windburned"
] | B | coal mine is a source of coal under the ground |
OpenBookQA | OpenBookQA-4073 | newtonian-mechanics
I should add that the above is simply what I, as a physicist with a fairly long experience, suspect is what is going on. It is not something I have read about and I am sure there is somewhere a more thorough discussion. So I hope I am right; I think I have a good argument. As I have described it above, I have in mind mainly the last part of the process where the wood only moves a little relative to the metal. In the earlier part, when the wood moves through a larger distance, it is inertia that is the main consideration, just like in the party trick where you abruptly whisk away a table cloth and the dishes on the table stay where there are. The more abrupt the better.
Added remark
It occurred to me that there is another thing worth mentioning here, that makes this method preferable to resting the axe head on something, or supporting the handle on a work top and hitting the head. It is that by hitting the end of the handle, with the head just hanging, you are going to deliver the force more accurately at the join, because it travels along the handle in exactly the direction you want. If instead you strike the head then there is a danger it will be knocked slightly obliquely, introducing a random tilt with each blow, which is liable to deform the wood and thus loosen the fit.
The following is multiple choice question (with options) to answer.
When a stick is smashed across the side of an oak, their interiors, on a microscopic level, | [
"enunciate",
"quake",
"mate",
"scream"
] | B | tapping two objects together causes the particles in those objects to vibrate |
OpenBookQA | OpenBookQA-4074 | Thanks once again for the perfectly clear answer. You have understood the problem well. I think that I can work things out myself now.
• All times are GMT -7. The time now is 09:21 AM.
The following is multiple choice question (with options) to answer.
In December around 3pm I will avoid using | [
"time travel",
"planets",
"magic",
"sungoggles"
] | D | when the seasons change from the summer to the fall , the amount of daylight will decrease |
OpenBookQA | OpenBookQA-4075 | climate, seasons, ice-age, axial-obliquity
Image originally from The Petroleum System Blog
Using that formula, the temperature at the poles (reduced to sea level) would be -16.8 °C (from the figure actual data points it can be seen that in real life the south pole is much colder than the north pole).
Now, the previous assumptions contradicts the requirement of "equilibrium", because the above scenario is far from steady state.
So now I will go on to try to describe what would happen to Earth's climate in your hypothetical scenario:
One thing that we learned by studying how the Milankovitch cycles trigger and reverse Pleistocene ice ages, is that to initiate an ice age cold winters are not necessary, what is needed are cold or mild summers.
Currently, the inclination of Earth axis (a.k.a. obliquity) varies between 22° and 24.5° , with a mean period of 41,040 years. When the inclination is 22°, mild summers occur and, therefore, the perfect condition to initiate an ice age (specially when combined with other ad-hoc orbital conditions). The permanent equinox situation you propose, is equivalent to an obliquity of 0°, that would lead to the coldest possible summer (this is, no summer at all). Therefore, such condition would set the Earth on track for an intense and never-ending ice age.
Let me explain how this could work: Using the formula above, the temperatures would be permanently below zero between the poles and latitudes 58.3°. Therefore, snow would start to accumulate in those areas, building an ice sheet and once the ice sheet gets thick enough it would start flowing outwards.
Figure from Lumen Learning.
The ice sheet then becomes self-sustaining due to two positive feedbacks:
Due to its high albedo, it would reflect most of the solar radiation back to the space, cooling down the Earth.
As the ice sheet advance, its thickness adds to the elevation of the terrain, therefore the surface is higher and colder, allowing snowfall beyond the 58.3° of latitude. The thicker it grows the more it can advance towards the equator.
The following is multiple choice question (with options) to answer.
If the days are more chilled than before, and yet still avoid freezing degrees, a likely assumption is that | [
"daylight lasts longer",
"daylight has lessened",
"daylight is brighter",
"nights are shorter"
] | B | when the seasons change from the summer to the fall , the amount of daylight will decrease |
OpenBookQA | OpenBookQA-4076 | home-experiment, food-chemistry, color
For cooking food, this above synthesis method seems unreasonable and overkill. I urge you to experiment with a few methods of forming the red curcumin-phospholipid complex yourself, with soy lecithin/eggs. I would have tried some methods out but I don't have these ingredients at home. see edit.
The advantage of having curcumin in a liposome is that it is much more stable: unlike the acid-base action, curcumin in a liposome remains stable across a wider range of pH's, as shown in this graph. This method does show promise, but as I mentioned, you would have to give this a try yourself.
Other practical solutions
Seasoned Advice would probably give you would get a better answer in this field, but I'll drop in my two cents. Generally, chilli powder is used to provide the red colour to Tandoori. More specifically, Kashmiri chilli powder is specifically used for tandoor preparations, such as tandoori chicken and chicken tikka. This powder is applied as a dressing (in combination with oil, rice flour etc after cooking the food) and during marination (chicken is marinated with curd, red chilli powder and turmeric).
Happy cooking!
References:
Kuntal Maiti, Kakali Mukherjee, Arunava Gantait, Bishnu Pada Saha, Pulok K. Mukherjee; Curcumin–phospholipid complex: Preparation, therapeutic evaluation and pharmacokinetic study in rats, International Journal of Pharmaceutics, Volume 330, Issues 1–2,
Sam-ang Supharoek, Kraingkrai Ponhong, Watsaka Siriangkhawut, Kate Grudpan;
Employing natural reagents from turmeric and lime for acetic acid determination in vinegar sample, Journal of Food and Drug Analysis, Volume 26, Issue 2,
Hong-Hao Jin, Qun Lu, Jian-Guo Jiang; Curcumin liposomes prepared with milk fat globule membrane phospholipids and soybean lecithin, Journal of Dairy Science, Volume 99, Issue 3,
Research gate: Why does curcumin have a red colour in the alkaline condition
Wikipedia: Phospholipids, Curcumin
The following is multiple choice question (with options) to answer.
Powdered substances such as oregano and pepper that are used to add flavor to foods come from | [
"beef",
"petroleum",
"cheese",
"producers"
] | D | plants are the source of spices |
OpenBookQA | OpenBookQA-4077 | species-identification, botany
Title: Identification of a plant Please help me to identify this plant
The plants can be found on italian balconies and I would like to buy one, but I do not know what I should look for.
The habit of the plant is trailing. This is likely to be a stone plant (Aizoaceae), depending on habit, it could well be the ice plant (Carpobrotus edulis). Stone plants are a quite diverse family of succulents from southern Africa, but are widespread throughout the western world as stabilizers of sand-dunes and in gardens as they are very tolerant of lack of watering and high salinity.
Ice plants are very common in the Mediterranean region, having become an invasive pest on much of the coastline.
If it is ice plant, then you can sub-cultivate it by taking a small part of the plant, usually leaves with a bit of stem, but even a leaf by itself may work, and placing it in water or on sandy soil. With regular watering, it should grow roots and then be plantable.
Apparently the leaves of ice plant are edible (hence the edulis part of the name), similar to Aloe I suspect.
The following is multiple choice question (with options) to answer.
You can use plants like star anise for | [
"hugging",
"running",
"swimming",
"sustenance seasoning"
] | D | plants are the source of spices |
OpenBookQA | OpenBookQA-4078 | the-sun, space, stellar-atmospheres
However, when you have something the Sun or even fog, the optical depth varies with the distance you're looking into that object. I'll talk about fog since it's familiar, but the same idea applies to the Sun's atmosphere. Say you're standing in a forrest and its very foggy out. There's a tree 1 meter away from you that you can see. You could measure your optical depth, $\tau$, of the fog between you and tree and might find that $\tau = 0.15$. Since $\tau$ is less than one, that implies you can see the tree, but the value of $\tau$ also implies how well you can see it. If $\tau = 0$, there's nothing between you and the tree to impede your ability to see it. Let's say there's another tree that's 5 meters away. Now there's more fog between you and the tree and while you can still see it, it is harder to see it. The optical depth of the fog between you and the tree 5 meters away might be $\tau = 0.75$. It's still less than one, implying the tree is visible, but because there's more fog between you and the tree, the optical depth is higher. Finally, there may be a tree 10 meters away with so much fog between you and the tree that the optical depth is $\tau = 1.5$. You can't see this tree because there's too much fog in the way. Hopefully you now realize that anything which is at a distance where $\tau > 1$ is not visible to you. That effectively defines a "surface" around you precisely when $\tau = 1$. Anything beyond that point is not visible and anything closer is visible.
If you're talking about the Sun, you can look at the Sun, but you'll only see light which originates from a point where $\tau < 1$. There are countless photons bouncing around inside the Sun, but you can't see them because they're in an opaque part of the Sun. Astronomers use the optical depth as a metric for defining the "surface" of the Sun.
The following is multiple choice question (with options) to answer.
Large trees block sunlight from reaching what? | [
"moons",
"outdoor floor",
"clouds",
"coffee grounds"
] | B | large trees block sunlight from reaching the ground |
OpenBookQA | OpenBookQA-4079 | cellular-respiration
Title: Do cold blooded animals generate any heat? In explaining energy and work to an 8 year-old I said that all conversion of energy generates heat as a by-product. For example, cars generate heat in their engines and running generates heat in our bodies. Then the 8 year-old said, except for cold-blooded animals.
So my question is, do cold-blooded animals generate any heat in their conversion of stored energy (food, fat, etc) into motion? If they generate heat, why are they cold-blooded? They do generate heat. They just do not SPEND energy specifically on heating their bodies by raising their metabolisms. This is a form of energy conservation. The metabolic rate they need to live is not nearly enough to heat their bodies.
An example of spending energy to heat the body is seen in humans shivering. Here muscle is activated not for its usual purpose, but to function as a furnace. "Warm-blooded" and "cold-blooded" is somewhat a misnomer. The correct way to think of it is...
Endotherm or ectotherm. Does the heat primarily come from within (endo) or from the surroundings (ecto). Endothermic animals include mammals. Most of their body heat is generated by their own metabolisms. Ectothermic animals include reptiles and insects. They absorb most of their body heat from the surroundings. This is not the same as saying they let their body temperature fluctuate with their surroundings, some avoid this by moving around to accomodate themselves.
Homeotherm or poikilotherm. Homeotherms want to maintain homeostasis for their body temperatures. They don't want it to change. Poikilotherms do not exhibit this behaviour, instead their body temperatures vary greatly with the environment.
We can have endotherm poikilotherms, such as squirrels, who let their body temperature drop while hibernating. Endotherm homeotherms, such as humans, where temperature is constant by means of complex thermoregulation. Ectotherm homeotherms, such as snakes (moving into shadow or into the sun to regulate temperature), and ectotherm poikilotherms, such as maggots.
The following is multiple choice question (with options) to answer.
All animals need to be what during cold conditions in order to survive? | [
"in space",
"warm enough",
"Freezing",
"lying down"
] | B | an animal requires warmth for survival |
OpenBookQA | OpenBookQA-4080 | astrophysics
Title: Is there any way to survive solarwinter like in Sunshine - movie? Is there any way to survive solarwinter like in Sunshine - movie?
Solar winter is where for some reason sun looses its capasity to produce radiation( heat etc.). It doesn't loose everything but some of its radiation energy( say 50 %) That causes earth to cool down causing next "ice age" Food could be grown using UV lights, powered by nuclear fission.
We could probably do it.
But it would be the spece equivalent of a human being on a life support machine - all our time and energy would be consumed just with survival, so while humans as a species might survive, our society, culture and science would probably slow down to a crawl, or disappear completely. Most other species would die off, so it would be a pretty dismal future.
The following is multiple choice question (with options) to answer.
What requires warmth for survival? | [
"the moon",
"an ocean",
"a bloodhound",
"a computer"
] | C | an animal requires warmth for survival |
OpenBookQA | OpenBookQA-4081 | resources, soil
Title: Is soil a renewable resource? My geology textbook tells me that soil is not renewable, and I agree with this, but there was some question in my class as to whether this is true.
Some soils take more than a human lifetime to regenerate. However, in crop production, it seems as if soil can be regenerated with additives.
In the scientific community of soil scientists, is soil considered a renewable resource by most of those scientists? Is there strong evidence to support this? Soil is an interesting case because although it is non-renewable (at any useful rate) as a 'bulk material' once removed from the ground, the nutrient content of soil can be renewed with fertilizers.
What a soil-scientist would understand as 'soil' is ultimately produced from the physical and chemical breakdown of solid bedrock at the base of the soil horizon. The rate at which this happens for natural soil production can vary substantially depending on the climatic conditions and other factors, but typically could range from 0.1 to 2.0 mm/yr.
In many intensively farmed regions, (top)soil is being removed by erosion much faster than it is being replaced by natural process. Removal of vegetation cover is enough to expose bare soil to rainsplash erosion at rates much greater than it is renewed. Once soil is bare, it becomes much more susceptible to erosion.
I think the additives you are referring to replenish the nutrient content of the soil, and not the the bulk material that would be produced by bedrock decomposition. With careful management, the fertility of existing soil can be maintained. But if the soil is allowed to be washed off or erode, for all practical purposes, the rate of replenishment is not fast enough for it to be classed as renewable in that sense.
This site has links to more aspects surrounding this issue.
The following is multiple choice question (with options) to answer.
A thing which is renewable and is also a resource is definitely | [
"obtained without fear of using up",
"likely to be gone soon",
"used up in short order",
"made to be extinct"
] | A | renewable resources can be used over again |
OpenBookQA | OpenBookQA-4082 | resources, soil
Title: Is soil a renewable resource? My geology textbook tells me that soil is not renewable, and I agree with this, but there was some question in my class as to whether this is true.
Some soils take more than a human lifetime to regenerate. However, in crop production, it seems as if soil can be regenerated with additives.
In the scientific community of soil scientists, is soil considered a renewable resource by most of those scientists? Is there strong evidence to support this? Soil is an interesting case because although it is non-renewable (at any useful rate) as a 'bulk material' once removed from the ground, the nutrient content of soil can be renewed with fertilizers.
What a soil-scientist would understand as 'soil' is ultimately produced from the physical and chemical breakdown of solid bedrock at the base of the soil horizon. The rate at which this happens for natural soil production can vary substantially depending on the climatic conditions and other factors, but typically could range from 0.1 to 2.0 mm/yr.
In many intensively farmed regions, (top)soil is being removed by erosion much faster than it is being replaced by natural process. Removal of vegetation cover is enough to expose bare soil to rainsplash erosion at rates much greater than it is renewed. Once soil is bare, it becomes much more susceptible to erosion.
I think the additives you are referring to replenish the nutrient content of the soil, and not the the bulk material that would be produced by bedrock decomposition. With careful management, the fertility of existing soil can be maintained. But if the soil is allowed to be washed off or erode, for all practical purposes, the rate of replenishment is not fast enough for it to be classed as renewable in that sense.
This site has links to more aspects surrounding this issue.
The following is multiple choice question (with options) to answer.
What resources can be used over again? | [
"finite",
"fuels",
"sustainable",
"one use"
] | C | renewable resources can be used over again |
OpenBookQA | OpenBookQA-4083 | meteorology, climate-change, gas, pollution
Title: Regarding various types of atmospheric pollution Does all the car pollution (from about 150 million cars at least in the U.S. and a lot more in all of North America and the rest of the world) all the smoke-stack pollution of various factories and all the Airline pollution running day after day have a deleterious and damaging effect on the general atmosphere and, over time, the climate?
Given all the observed pollution that China has caused itself and some of the resulting weird weather events there this certainly seems to be evidence of the damaging effects of car and factory pollution. Has anyone calculated how much exhaust from cars is produced in one day on average in a 'moderate' sized city?
Of course it seems with all the increased oil production in the U.S. and elsewhere we, human beings are going to keep are love-affair with gas-powered cars for the next 200 or 300 years. That is if we don't use up all the oil and gas in the ground before then. As a USA resident, the EPA is the best place to start when wondering about the emissions inventory of atmospheric pollutants or pollutant precursors that affect the National Ambient Air Quality Standards (e.g. Particulate Matter, Carbon Monoxide, Sulfur Dioxide, Lead, Nitrogen Oxides, Volatile Organic Compounds). The EPA compiles a comprehensive emissions inventory of all criteria pollutants at the county level which is available in the National Emissions Inventory (compiled once every 3 years). You can see the summary of your county at http://www.epa.gov/air/emissions/where.htm. As for the effects of atmospheric pollution, it is important to consider the lifetime of said pollutants in the atmosphere in order to put their environmental impacts into perspective. For instance, the air pollutants covered by the National Ambient Air Quality Standards have immediate health effects when high concentrations are breathed in regularly. Both animals and plants are adversely affected by these irritating and sometimes toxic chemicals, but these pollutants are also reactive and do not last long in the atmosphere unless they are constantly being replenished (e.g. daily traffic). Air quality also impacts critical nitrogen loads on ecosystems and possible production of acid rain.
The following is multiple choice question (with options) to answer.
Pollution is | [
"trees in a green forest",
"when wind carries seeds",
"throwing a candy wrapper down",
"Fish swimming in the sea"
] | C | pollution is a source of pollutants |
OpenBookQA | OpenBookQA-4084 | meteorology, climate-change, gas, pollution
Title: Regarding various types of atmospheric pollution Does all the car pollution (from about 150 million cars at least in the U.S. and a lot more in all of North America and the rest of the world) all the smoke-stack pollution of various factories and all the Airline pollution running day after day have a deleterious and damaging effect on the general atmosphere and, over time, the climate?
Given all the observed pollution that China has caused itself and some of the resulting weird weather events there this certainly seems to be evidence of the damaging effects of car and factory pollution. Has anyone calculated how much exhaust from cars is produced in one day on average in a 'moderate' sized city?
Of course it seems with all the increased oil production in the U.S. and elsewhere we, human beings are going to keep are love-affair with gas-powered cars for the next 200 or 300 years. That is if we don't use up all the oil and gas in the ground before then. As a USA resident, the EPA is the best place to start when wondering about the emissions inventory of atmospheric pollutants or pollutant precursors that affect the National Ambient Air Quality Standards (e.g. Particulate Matter, Carbon Monoxide, Sulfur Dioxide, Lead, Nitrogen Oxides, Volatile Organic Compounds). The EPA compiles a comprehensive emissions inventory of all criteria pollutants at the county level which is available in the National Emissions Inventory (compiled once every 3 years). You can see the summary of your county at http://www.epa.gov/air/emissions/where.htm. As for the effects of atmospheric pollution, it is important to consider the lifetime of said pollutants in the atmosphere in order to put their environmental impacts into perspective. For instance, the air pollutants covered by the National Ambient Air Quality Standards have immediate health effects when high concentrations are breathed in regularly. Both animals and plants are adversely affected by these irritating and sometimes toxic chemicals, but these pollutants are also reactive and do not last long in the atmosphere unless they are constantly being replenished (e.g. daily traffic). Air quality also impacts critical nitrogen loads on ecosystems and possible production of acid rain.
The following is multiple choice question (with options) to answer.
Pollution is a source of what? | [
"dirtying agents",
"purity",
"fertilization",
"cleanliness"
] | A | pollution is a source of pollutants |
OpenBookQA | OpenBookQA-4085 | evolution, homework
Title: Can someone help me analyze this article? I need to read this article — "Beyond the rainbow" by
Marie-Claire Koschowitz et al., for an exam.
Following are some questions for which I could not figure the answer out after reading.
1) Why does this miniaturization necessitates insulation ? Following is quote from article: "For fast-growing, presumably warm- blooded animals , such miniaturization would only have been possible with sufficient body insulation. "
2) Dinosaurs suppose to have tetrachromacy. The article mentions "dinosaurs were endowed with the highly differentiated color vision of birds". Does this mean Dinosaur's "inherited" their tetrachromacy from birds ? Why does the article mention reptiles before that ? Are birds reptiles ?
3) The article starts talking about how mammals develop fur and lost their highly differentiated color vision because they gave up structural color signaling. What is the direct connection between mammals and the dinosaurs ? I don't see the parallel here....why bring the mammals into the discussion ?
4) What is the connection between pennaceous feather and planar feathers ?
Any or all questions answered is welcome ! Thanks ! I will answer the questions one by one-
Why does this miniaturization necessitates insulation ?
An organism's volume determines the total amount of heat that can be stored. The loss (exchange) of heat between the body and external environment mainly occurs on the skin's surface. Hence, body volume determines how much heat is stored, while body surface determines how fast that heat is dissipated to the environment. Volume increases with a power of three with radius, while surface increases with a power of two. Hence, smaller animals have large surface-to-volume ratios, which decreases rapidly with body size. Hence, small animals will dissipate relatively more heat per unit of time.
Dinosaurs suppose to have tetrachromacy. The article mentions "dinosaurs were endowed with the highly differentiated color vision of birds". Does this mean Dinosaur's "inherited" their tetrachromacy from birds ?
No, birds are the closest living relatives to dinosaurs, and birds can be said to have inherited tetrachromacy from dinosaurs - see the cladogram below.
The following is multiple choice question (with options) to answer.
Small reptiles in Texas can be brown or green on command, we call this | [
"sunscreen",
"concealment",
"social media",
"cooling agent"
] | B | An example of camouflage is when something changes color in order to have the same color as its environment |
OpenBookQA | OpenBookQA-4086 | quantum-mechanics, electromagnetism, electromagnetic-radiation
Thus one can imagine such a scenario, but can never actually do it except over some finite area. You can actually see such calm areas if you have a nice water table with two sources of waves operating in synch; you can also sometimes see it in nature.
The following is multiple choice question (with options) to answer.
A thing which is invisible to the passing gaze, yet has a visible form is probably | [
"a bald eagle",
"a stonefish",
"a cow",
"a hippo"
] | B | An example of camouflage is when something changes color in order to have the same color as its environment |
OpenBookQA | OpenBookQA-4087 | When morning comes and all $N$ pirates wake up, they see the greatly diminished pile and a happy fat monkey.
The question is: how many bananas could there have been in the original pile for this to occur?
• Is this for all sets of possible bananas? – awesomepi May 22 '14 at 15:58
• ...The number of possible bananas is limited depending on N, N can be any natural number (except 1). – kaine May 22 '14 at 16:27
• The way I remember it, concludes with the pirates waking up, finding a greatly diminished pile of bananas, each taking their share of $x$ bananas, and feeding the final banana to the monkey. That would give you a starting pint, but I'm not sure it's correct. – SQB May 23 '14 at 7:01
• @SQB I did not remember it ending that way but that could be my bad memory. Mathematically though, I am pretty sure that would be the same as N+1 pirates so Ross's answer still applies. – kaine May 23 '14 at 12:52
• @kaine it is not the same, since N+1 pirates would always divide by (N+1) here it is always a division by N, only it happens N+1 times with the waking up part. – Falco Aug 6 '14 at 11:22
The basic idea is to work backwards.
The last pirate must have found $N+1$ bananas, because he had to find enough bananas remaining for at there to be least 1 banana in the pile left for each pirate. He took 1, fed 1 to the monkey, and left $N-1$. That $N+1$ means that the next to last pirate found $\frac N{N-1}\cdot (N+1)+1$ and so on.
A cute trick is to recognize that there could have been
$-(N-1)$ bananas. Each pirate gives the monkey $1$, takes $-1$, and leaves the pile the same size as before. Since we need to divide it by $N$ for each pirate, the next solution is higher by $N^N$, so the minimal positive solution is $N^N-N+1$ bananas.
The following is multiple choice question (with options) to answer.
A monkey grabs a banana in order to | [
"build a shelter",
"find a mate",
"hit enemies",
"gain nutrients"
] | D | eating food is used to get nutrients by living things |
OpenBookQA | OpenBookQA-4088 | rain, natural-disasters, flooding
Edit 2 August 2020
Concerning successful flood control measures, two quickly come to mind, the Thames Barrier in London, England and the Aswan Dam in Egypt, particularly the Aswan High Dam.
The Thames Barrier is a movable barrier system that is designed to prevent the floodplain of most of Greater London from being flooded by exceptionally high tides and storm surges moving up from the North Sea. It has been operational since 1982. When needed, it is closed (raised) during high tide; at low tide, it can be opened to restore the river's flow towards the sea.
Based on the success of the Low Dam, then at its maximum utilization, construction of the High Dam became a key objective of the government following the Egyptian Revolution of 1952; with its ability to better control flooding, provide increased water storage for irrigation and generate hydroelectricity the dam was seen as pivotal to Egypt's planned industrialization. Like the earlier implementation, the High Dam has had a significant effect on the economy and culture of Egypt.
The following is multiple choice question (with options) to answer.
Blocking a river creates homes for | [
"satellites",
"fish",
"rocks",
"mermaids"
] | B | damming a river can cause a lake to form |
OpenBookQA | OpenBookQA-4089 | newtonian-mechanics, conservation-laws
So generally the plate will move : it could translate and also rotate. Constraining forces (and torques) would be needed to keep it in place. If it is released it will move.
The following is multiple choice question (with options) to answer.
If a thing is going to be relocated with a shove, then | [
"someone is forced to eat crackers",
"some exertion is necessary",
"someone needs to lose weight",
"a gym needs to be opened"
] | B | pushing an object requires force |
OpenBookQA | OpenBookQA-4090 | control, motion-planning, algorithm
The issue I have to treat is, how to optimally bypass the blue obstacle even I don't know how deep it is. Driving to the left and to the right only to capture better data points (to generate a 3D model) is not possible.
The following is multiple choice question (with options) to answer.
Relocating a stalled vehicle requires a lot of | [
"slopes",
"force",
"wind",
"gravity"
] | B | pushing an object requires force |
OpenBookQA | OpenBookQA-4091 | geology
Title: Where do riverbed stones come from? Have they always been here since the river was formed? Are some newer than others? Riverbed 'stones' - I assume you mean things like pebbles, boulders, etc. are pieces of rock that have weathered out and been deposited in the river. Some come from rock that is very close to where they are located and some have been transported from very far away. In general (and it is a very broad generalization) the rounder the stone, the longer it has been in the river and the more likely it is to have come from far away. Of course that depends on the hardness of the rock, and other factors, too.
Some rocks are newer than others. Some have been formed quite recently and some are billions of years old.
The following is multiple choice question (with options) to answer.
Things occurring in stoney areas produces all of these: | [
"species of orange bees",
"places where geese breed",
"paper towel holding tubes",
"materials such as talc"
] | D | all minerals are formed by natural geological processes |
OpenBookQA | OpenBookQA-4092 | mantle, crystallography, crystals, pressure, diamond
That’s because the Botswana diamond also contained a high-pressure form of ice as well as another high-pressure mineral known as wüstite (SN: 3/8/18). The presence of those inclusions helped narrow down the rough pressures at which the davemaoite might have formed: somewhere between 24 billion pascals and 35 billion pascals, Tschauner says. It’s hard to say exactly what depth that corresponds to, he adds. But the discovery directly links heat generation (the radioactive materials), the water cycle (the ice) and the carbon cycle (represented by the formation of the diamond itself), all in the deep mantle, Tschauner says.
From the article I think that I'm being told that the diamond is preserving enough pressure to keep both the "davemaoite" and " a high-pressure form of ice" and the wüstite stable as well.
Am I understanding this correctly?
Question: When diamonds "migrate" from deep underground to the surface, do they maintain pressure inside when there is no more pressure outside? If so, how?
I would think that as the diamond rises to the surface and the pressure relaxes outside it would relax and expand uniformly and the pressure would relax inside as well. If that's not the case, why not?
The following is multiple choice question (with options) to answer.
Diamonds are made and dispersed by | [
"volcanoes",
"gypsies",
"giants",
"clouds"
] | A | all minerals are formed by natural geological processes |
OpenBookQA | OpenBookQA-4093 | genetics
I will discuss a few concepts and slowly introduce the concept of heritability in both senses.
Phenotypic trait
The phenotype is the consequence of the genotype on the world. In brief, a phenotypic trait is any trait that an individual is made of!
Quantitative trait
A quantitative trait is any trait that you can measure and ordinate, that is any trait that you can measure with numbers. For example, height is a quantitative trait as you can say that individual A is taller than individual B which is itself taller that individual C.
Variance of a quantitative trait
In a population, different individuals can have different values for a given phenotypic trait $x$. Because we are talking about quantitative traits we can calculate the variance of the trait in the population. Let's call this variance $V_P$ such as
$$V_P=\frac{1}{N}\sum_i (x_i - \bar x)^2$$
In the above equation, $x_i$ is the value of the phenotypic trait $x$ of individual $i$. $N$ is the population size (there are $N$ individuals in the population) and $\bar x$ is the average phenotypic trait $x$ in the population.
$$\bar x = \frac{1}{N}\sum_i x_i$$
What is causing phenotypic variance
Why would a population display any phenotypic variance? Why wouldn't we just look exactly the same? What explains these differences?
For some traits, we see very little variance. To consider the example the OP gave in the post, the number of arms in the human population shows very little variance. However, there is quite a bit of variance in terms of the number of IQ, in terms of height or of weight.
There are two (main) sources of variance that are underlying this phenotypic variance. The first one is the genetic variance and the second one is the environmental variance. We will call the genetic variance $V_G$ and the environment variance $V_E$.
The following is multiple choice question (with options) to answer.
Which of these animal traits is generally determined by environmental factors rather than heredity? | [
"eye color",
"height",
"hair length",
"number of chromosomes"
] | C | genes are a vehicle for passing inherited characteristics from parent to offspring |
OpenBookQA | OpenBookQA-4094 | species-identification, zoology, bone-biology, bone
Title: What is this bone from? This object showed up on my fire escape in New York city. It appears to be some kind of bone. It's a bit smaller than an adult human hand. What animal is it from? Given the size and thin/elongated ilia as well as the urban location, I think a domestic cat and/or a raccoon are likely candidates. I'm leaning toward cat.
Cat pelvis:
VCA Hospitals
Ventral view of domestic cat pelvis; Source: BoneID
Raccoon Pelvis
Anterior view of raccoon pelvis; Source: BoneID
I'm not an expert in differentiating these two species' bones. I will note that your specimen is more or less in between the sizes of these two species. Your size is probably closer to the raccoon, but a cat is just more likely given the location.
The most noticeable trait that stands out to me is the size/pointedness of the ischial tuberosity, which better matches that of the cat.
The following is multiple choice question (with options) to answer.
A tiger with a stubby tail most likely | [
"has children with long tails",
"had ancestors with that trait",
"has siblings with long tails",
"had parents with long tails"
] | B | genes are a vehicle for passing inherited characteristics from parent to offspring |
OpenBookQA | OpenBookQA-4095 | ecology
Title: Statement about Tropical Rainforests I made a statement about tropical rainforests, and I want to know if it's somewhat true or not:
The soil in tropical rainforests is not exceptionally fertile, because it contains few minerals. The reason that a tropical rainforest has a huge amount of vegetation is because of the quick mineralisation. If a dead leaf falls onto the ground, it immediately gets turned into minerals, which the plants immediately use for sustaining theirselves There are many websites which describe this phenomenon. They all seem to confirm the basic premise of the question: in tropical rain forests most of the minerals are held in the biomass and rapid decomposition contributes to the recycling of these nutrients for new growth. One example is here.
Tropical rainforests are noted for the rapid nutrient cycling that occurs on the ground. In the tropics, leaves fall and decompose rapidly. The roots of the trees are on the surface of the soil, and form a thick mat which absorbs the nutrients before they reach the soil (or before the rain can carry them away). The presence of roots on the surface is a common phenomenon in all mature forests; trees that come along later in succession win out in competition for nutrients by placing their roots over top of the competitors, and this pattern is seen in the temperate rainforest as well. What does not occur in the temperate rainforest, however, is a rapid cycling of nutrients. Because of the cold conditions and the acidity released by decomposing coniferous needles on the forest floor, decomposition is much slower. More of the nutrients are found in the soil here than would be the case in a tropical forest, although like the tropical forest most of the nutrients are held in the plants and animals themselves.
I looked for actual evidence of these differences in rates of decomposition and I found this:
Salinas, N. et al. (2011) The sensitivity of tropical leaf litter decomposition to temperature: results from a large-scale leaf translocation experiment along an elevation gradient in Peruvian forests. New Phytologist 189: 967-977
The following is multiple choice question (with options) to answer.
A producer is relocated from a small pot into a wild forest. The producer is able to do this with relative ease: | [
"acclimate",
"rhyme",
"befriend",
"float"
] | A | changes in an environment cause plants to adapt to survive |
OpenBookQA | OpenBookQA-4096 | meteorology, atmosphere, wind, air-currents
Title: Where does wind come from? Wind is (according to Wikipedia) the flow of gases on a large scale.On the surface of the Earth, wind consists of the bulk movement of air.
What forces would cause such a mass movement of air? Wind is caused by pressure differences. Think of a balloon full of air; poke a hole in it and the air comes out. Why? Because the pressure in the balloon is higher than outside, and so to regain equal pressure, mass moves and that is the wind.
There is a bit more to this in the atmosphere as the Earth rotates and near the surface friction also plays a role. The equation of motion is the Navier-Stokes and in vector form in Cartesian space is:
$$\dfrac{\partial\mathbf u}{\partial t} = - \mathbf u \cdot \nabla \mathbf u -\dfrac{1}{\rho}\nabla p-2 \mathbf \Omega \times \mathbf u + \mathbf g + \mathbf F$$
In this equation, $\mathbf u$ is the vector wind, $(\mathbf u \cdot \nabla)$ is the advection operator, $\rho$ is density, $\mathbf \Omega$ is the vector rotation of the Earth, $\mathbf g$ is effective gravity and $\mathbf F$ is friction.
The LHS is the time rate of change of the wind at a point in space (as opposed to following the parcel). The RHS represent a number of factors that produce a change in the wind. From left to right:
Advection of momentum (non-linear)
Pressure gradient force (this is wind blowing from high to low pressure)
Coriolis force (this turns wind to the right in the NH and left in the SH and causes the wind to flow parallel to isobars)
gravity (provides hydrostatic balance with the PGF in the vertical)
Friction (in the boundary layer you may see this as $\nu\nabla^2\mathbf u$)
The following is multiple choice question (with options) to answer.
Which two forces are likely the cause of canyons? | [
"water plus fire",
"fire and brimstone",
"water plus gravity",
"H20 and lemmings"
] | C | most canyons are formed by flowing rivers through erosion over long periods of time |
OpenBookQA | OpenBookQA-4097 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
If a thing is using other animals for nourishment, then the thing is a | [
"predator",
"producer",
"inanimate",
"herbivore"
] | A | a predator eats other animals for food |
OpenBookQA | OpenBookQA-4098 | zoology
Capybara, rabbits, hamsters and other related species do not have a complex ruminant digestive system. Instead they extract more nutrition from grass by giving their food a second pass through the gut. Soft fecal pellets of partially digested food are excreted and generally consumed immediately. Consuming these cecotropes is important for adequate nutritional intake of Vitamin B12. They also produce normal droppings, which are not eaten.
Young elephants, pandas, koalas, and hippos eat the feces of their mother to obtain the bacteria required to properly digest vegetation found on the savanna and in the jungle. When they are born, their intestines do not contain these bacteria (they are completely sterile). Without them, they would be unable to obtain any nutritional value from plants.
Eating garbage and human feces is thought to be one function of dogs during their early domestication, some 12,000 to 15,000 years ago. They served as our first waste management workers, helping to keep the areas around human settlements clean. A study of village dogs in Zimbabwe revealed that feces made up about 25% of the dogs’ overall diet, with human feces making up a large part of that percentage.
Coprophagia
Daily rhythms of food intake and feces reingestion in the degu, an herbivorous Chilean rodent: optimizing digestion through coprophagy
Coprophagia as seen in Thoroughbred Foals
The following is multiple choice question (with options) to answer.
What eats other animals for food? | [
"marlins",
"goats",
"rabbits",
"elephants"
] | A | a predator eats other animals for food |
OpenBookQA | OpenBookQA-4099 | zoology, ecology, species-distribution, migration
Title: How do animals end up in remote areas? I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough.
They usually don't seem to be connected to each other. If it were any other land animal I would figure they walk from one spot to another, but in the case of frogs, I don't imagine their range is very vast. But often these marshy spots can be separated by fairly large distances to a frog.
So this brings me to my question: how do each of these spots end up with frogs in them? I don't imagine a frog is going to go hopping over a hill to get to a marsh on the other side, is it? This question pertains to organism dispersal, which is a very active field of study with relation to it's impact on conservation efforts. Much of what I will say below has been covered in this wiki.
Definition: From the Wiki
Technically, dispersal is defined as any movement that has the
potential to lead to gene flow.
It can be broadly classified into two categories:
Density dependent dispersal
Density independent dispersal
The question of frogs and fishes both refer to Density independent dispersal, while an example of density independent dispersal can be the competition for habitat space between big cats and humans (this is a WWF pdf)
From the wiki:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage
of various forms of kinetic energy occurring naturally in the
environment. This is referred to as density independent or passive
dispersal and operates on many groups of organisms (some
invertebrates, fish, insects and sessile organisms such as plants)
that depend on animal vectors, wind, gravity or current for dispersal.
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends
on factors such as local population size, resource competition,
habitat quality, and habitat size.
Currently, some studies suggest the same.
This study in particular studied the movement and habitat occupancy patterns within ephemeral and permanent water bodies in response to flooding. They found that during flooding these frogs moved out to flooded ephemeral water bodies and later on moved back again to the permanent ones.
Other suggested readings for those highly interested in the subject may include this (a phd thesis) and this (a project report)
The following is multiple choice question (with options) to answer.
Which likely would be a reason a deer leaves its habitat? | [
"a light rain makes its habitat unlivable",
"it wants to see the ocean",
"dry brush has accumulated and a camper left a lit cigar",
"the temperature is slightly colder than it was the day before"
] | C | a deer lives in a forest |
OpenBookQA | OpenBookQA-4100 | zoology, ecology, species-distribution, migration
Title: How do animals end up in remote areas? I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough.
They usually don't seem to be connected to each other. If it were any other land animal I would figure they walk from one spot to another, but in the case of frogs, I don't imagine their range is very vast. But often these marshy spots can be separated by fairly large distances to a frog.
So this brings me to my question: how do each of these spots end up with frogs in them? I don't imagine a frog is going to go hopping over a hill to get to a marsh on the other side, is it? This question pertains to organism dispersal, which is a very active field of study with relation to it's impact on conservation efforts. Much of what I will say below has been covered in this wiki.
Definition: From the Wiki
Technically, dispersal is defined as any movement that has the
potential to lead to gene flow.
It can be broadly classified into two categories:
Density dependent dispersal
Density independent dispersal
The question of frogs and fishes both refer to Density independent dispersal, while an example of density independent dispersal can be the competition for habitat space between big cats and humans (this is a WWF pdf)
From the wiki:
Density-independent dispersal
Organisms have evolved adaptations for dispersal that take advantage
of various forms of kinetic energy occurring naturally in the
environment. This is referred to as density independent or passive
dispersal and operates on many groups of organisms (some
invertebrates, fish, insects and sessile organisms such as plants)
that depend on animal vectors, wind, gravity or current for dispersal.
Density-dependent dispersal
Density dependent or active dispersal for many animals largely depends
on factors such as local population size, resource competition,
habitat quality, and habitat size.
Currently, some studies suggest the same.
This study in particular studied the movement and habitat occupancy patterns within ephemeral and permanent water bodies in response to flooding. They found that during flooding these frogs moved out to flooded ephemeral water bodies and later on moved back again to the permanent ones.
Other suggested readings for those highly interested in the subject may include this (a phd thesis) and this (a project report)
The following is multiple choice question (with options) to answer.
Whitetail are found in what kind of habitat | [
"the ocean",
"temperate",
"arctic",
"dessert"
] | B | a deer lives in a forest |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.