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Saturday, March 26, 2022

Why are our intestines so dang long?

Why are our intestines so dang long?


Why are our intestines so dang long?

Posted: 26 Mar 2022 07:35 PM PDT

What would happen if the vasa recta flowed in the same direction as the loop of Henle?

Posted: 26 Mar 2022 09:10 PM PDT

I am trying to better understand nephron physiology by thinking of what would happen if things were changed around.

My understanding is that the vasa recta is vascular tissue (fenestrated capillary) whose purpose is mainly to provide perfusion to the tissues of the medullary cortex, and which also helps with h2o and solute re-absorption from the nephron.

I also somewhat understand that the design of the vasa recta is set up in a clever way so as not to 'wash out' and 'carry away' the cortico-medullary salt concentration gradient created by the countercurrent multiplication system of the loop of Henle, while it is busy carrying out its mission of perfusion.

It sort of makes sense to me that the hairpin turn of the vasa recta, combined with low speed of flow, allows for salt to leave the VR on its ascent from the medulla almost as much as it was entering during the descent.

But my A&P2 textbook really stresses the importance of the reversed flows, and I don't see the significance. Why would a co-current flow between the vasa recta and the loop of Henle be problematic in steady state?

The only relevant asymmetry I can pinpoint is the differing permeability of the limbs of the loop of Henle.

Could it be as simple as: the sodium leaving the ascending limb of Henle would diffuse into the cocurrent vasa recta AFTER it has already completed its descent, causing complete washout of the gradient?

I'm not so sure, and this is where my tiny brain stops working.

submitted by /u/gorplo
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Has domesticating livestock influenced micro biome in animals?

Posted: 26 Mar 2022 05:25 PM PDT

Changes in diet and even chemical control with the use of antibiotics has surely had an effect on the gut flora of so many animals no?

If so has there been new species evolve - possibly like the plastic eating variety mentioned in a recent post - entirely made possible due to the changed biochemistry of the domestication history?

Lastly could some of those have migrated to wild animals, or crossed species ?

submitted by /u/daynomate
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How does an adrenal tumor affect the eyes?

Posted: 26 Mar 2022 02:09 PM PDT

What lead Kepler to discover his third law ?

Posted: 26 Mar 2022 05:23 PM PDT

What lead Kepler to discover his third law ?

submitted by /u/Representative_Loss
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Why can't we transplant Femoral head?

Posted: 26 Mar 2022 11:14 AM PDT

Like any other transplant, what stops us from transplanting cadaver or donor femur heads with intact major terminal arteries and then anastomose that to patient rather than doing THR, provided theoretically no limit of donors/sizes/matches. What stops us then, just fine vessel suturing? If we can do transtrochanteric osteotomies, then why not total femur head grafting?

submitted by /u/Lord_Crawley
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Since the Dragon capsule is fully autonomous could it be used to “park” next to Hubble and provide the ability for a repair/upgrade mission?

Posted: 25 Mar 2022 03:58 PM PDT

I understand interior volume is limited but maybe be reconfigured for 2 pilots and room for spacesuits and tools/equipment. Or launch cargo Dragon and put it into close proximity with the equipment for repair or upgrade. Then be able to bring it closer when the crew Dragon arrives. The cost of a Falcon 9 launch is tiny compared to a shuttle launch. And then there is Starship coming within a few years.

submitted by /u/Clueless_dope
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when did modern elephants diverge into the african and asian varieties?

Posted: 25 Mar 2022 04:40 PM PDT

So basically I was reasearching elephants out of boredom and got confused. Im sure this sounds stupid but when and how did the 2 groups diverge? And how did mammoths and the american mastodonts fit into the picture?

Edit: another stupid question, why is it both species of african elephant have a scientific name starting with laxodonta but not asian elephants?

submitted by /u/Sea_Charity_3927
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How far from Earth does an object need to be before it no longer makes sense to say “it’s high up?”

Posted: 25 Mar 2022 05:12 PM PDT

We would commonly say birds/planes/clouds are "high" relative to us. When a rocket is launched we ask "how high?"

How high does something need to be before we just talk about it in terms of "distance from earth" rather than "height off the ground?" Is there a specific scientific consensus for that?

submitted by /u/Grandclosing
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When soup, broth, or nutmilk is sold in a Tetra-Pak or similar cardboard carton, is it boiled (canned) in the packaging?

Posted: 25 Mar 2022 04:05 PM PDT

And if so, wouldn't that lead to chemicals from the packaging leaching into the liquid?

submitted by /u/orangegore
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Why does Hydrochloric Acid dissociates more than Sulfuric Acid, or more than most other acids for that matter?

Why does Hydrochloric Acid dissociates more than Sulfuric Acid, or more than most other acids for that matter?


Why does Hydrochloric Acid dissociates more than Sulfuric Acid, or more than most other acids for that matter?

Posted: 26 Mar 2022 10:39 AM PDT

This question comes from one I asked my chemistry teacher: how can we tell apart strong acids and bases from weaker acids and bases by JUST knowing their name (ie KOH, H3PO4, etc) and properties we can derive from the periodic table, atomic structure, so on. My teacher's answer kept coming down "strong acids and bases dissociates more than weak acids and bases" and I kept asking "Why? Why does [random acid] dissociate more than [weaker random acid]? What properties do they differ that allows one acid to be stronger than the other?" . . . and eventually my teacher just said "I don't know." Needless to say I'm unsatisfied, any help please?

submitted by /u/DaybreakHonor
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Why did evolution make things that can impact your health negatively generally taste better than things that are good for your health?

Posted: 25 Mar 2022 04:30 PM PDT

How does anesthesia "tax the body"?

How does anesthesia "tax the body"?


How does anesthesia "tax the body"?

Posted: 25 Mar 2022 04:21 PM PDT

I recently had surgery and the doctor recommended spinal painkiller instead of general anesthesia due to the latter being very "taxing on the body", and that it takes a while to recover from it. Why is this the case?

submitted by /u/rodionraskol
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Why don't steel bridges e.g. the Sydney Harbour Bridge, suffer metal fatigue?

Posted: 24 Mar 2022 08:28 PM PDT

Millions of tons of moving, vibrating trains, trucks, busses and cars every day. Forces of wind and rain. Fierce heat and cold yet no-one ever talks about fatigue in the steel. Especially in cables like Brooklyn bridge or the Golden Gate Bridge?

submitted by /u/Nodsworthy
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Can each ring of a tree be carbon dated to its respective year?

Posted: 25 Mar 2022 08:20 AM PDT

If we carbon date a piece of wood, is it an approximation of all the years or a specific ring? Do the inside layers of a tree regenerate along the way that the whole tree is the same newness as the most recent ring?

submitted by /u/toomeynd
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Do people with Face Blindless still experience the uncanny valley effect from looking at messed-up Faces?

Posted: 24 Mar 2022 05:48 AM PDT

So, most people are creeped out by human faces that have been altered or are just a bit 'off", such as the infamous "Ever Dream This Man?" face, or the many distorted faces featured in the "Mandela Catalogue" Youtube series, because of the Uncanny Valley effect. But when it comes to people with Prosopagnosia (face blindness), does that instinctive revulsion still happen? I mean, the reason we find altered faces creepy is because our brains are hard-wired to recognize faces, so something that strongly resembles a face but is unnatural in some way confuses our brain. But if someone who literally can't recognize a face as a face looks at something like that, would they still be creeped out?

EDIT: Well, after reading some comments from actual faceblind people, I have learned I have been gravely misinformed about the nature of face blindness. Still, this is all very fascinating.

submitted by /u/Omny87
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How do subterranean animals cope without sunlight?

Posted: 25 Mar 2022 04:23 PM PDT

Humans and many other species depend on sunlight for vitamin-D, regulating blood sugar and serotonin. Prolonged lack of sun-exposure will lead to many health issues and eventual death.

But there are lots of animals that get little to no sunlight, for example moles and naked mole-rats that live most of their lives deep underground with no ill effect.

What adaptions do subterranean animals have that allows them to live without light?

submitted by /u/valonianfool
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Why is there a desert on the Arabian peninsula?

Posted: 24 Mar 2022 06:29 PM PDT

The Arabian peninsula is surrounded on water on 3 sides and has mountain ranges that could catch precipitation coming from the red sea, Persian gulf and Arabian sea. I know that its an extension of the Sahara but shouldn't there be areas on the peninsula that do have good amounts of precipitation?

submitted by /u/SomePoorAfricanChild
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Can someone explain how Thrombopoiesis Works, especially in terms of how Megakaryocytes insert mRNA and translational machinery inside platelets?

Posted: 25 Mar 2022 02:48 PM PDT

I am a highschool student researching vestigial mRNA inside platelets, and I could use some help with understanding this topic. If you have any articles that you think I should check out as well, that would be much appreciated.

Thank you!

submitted by /u/redhairinthesun
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Do bears lose muscle/strength while hibernating?

Posted: 24 Mar 2022 09:08 AM PDT

I'm just thinking how human muscles degrade after a while of not using them. For example, if a person is bed-bound for a while or even astronauts coming back home from the ISS, they need some sort of rehab to gain strength back. Does that happen to bears?

submitted by /u/ElevatedTreeMan
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Why does coffee work as a laxative?

Posted: 24 Mar 2022 06:51 AM PDT

Does particle handedness affect matter-antimatter annihilation?

Posted: 24 Mar 2022 08:21 AM PDT

For example, is there any theoretical difference between a left-handed electron interacting with a right-handed antielectron and a left-handed electron interacting with a left-handed antielectron?

submitted by /u/CatgirlsAndFemboys
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What makes a Portugese man o' war different from other animals?

Posted: 24 Mar 2022 06:29 AM PDT

According to wikipedia, a Portugese man o' war (and other Siphonophorae) isn't a single organism per-se, but actually a colony of zooids all working together, which can't exist separately.

But how is this different to 'regular' animals? Animals are also composed of multiple components (organs) made of cells, which also can't exist separately. So how are man o' wars and zooids different to other animals?

submitted by /u/TheCoop1986
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Does every star system have its own habitable zones?

Posted: 24 Mar 2022 08:39 AM PDT

Just curious, incase we were to become Interstellar travellers, can we just insert space-stations in an orbit around stars where the temperature, gravity etc are optimal

submitted by /u/pzuz
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What is the physiological mechanism through which fatigue/tiredness can cause visual/auditory anomalies?

Posted: 24 Mar 2022 07:36 AM PDT

I'm a very fatigued medical student studying not-neuro right now, but I always notice these little visual anomalies when I am very tired. Like when I stare at words on a computer screen, they will start to ripple, or I'll see color start to materialize on a white screen. (I know I need sleep, thank you)

I'm curious how fatigue produces this. I have heard that extreme exhaustion will cause visual/auditory hallucinations, but never figured out the mechanism. What kind of "wires" are crossing to form this? Is it some sort of 5-HT mediated supplementary pathway that is altering the cortical processing of cranial nerve sensory inputs? That's my first guess.

Thank you for your help! I'm outsourcing help so I don't end up going down another google scholar rabbit hole the day before a final...

submitted by /u/TheineandTheobromine
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Why does cAMP not interfere with other cell signalling responses?

Posted: 24 Mar 2022 11:40 AM PDT

From my A-level understanding is that a hormone will bind to a receptor, the receptor will release cAMP or another second messenger and that will start an enzyme cascade. But if this (or any other second messenger) is being released into the cell, how does it only activate the PKA for this response? If this is a common second messenger and multiple hormone receptors are releasing this generic messenger molecule into the cell why does it not travel to the start of a different enzyme cascade and trigger that response?

submitted by /u/The_Armadillo_Boi_
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How are biological substrates (tRNAs, free nucleic acids, etc.) localised for use in building larger molecular structures?

Posted: 23 Mar 2022 10:35 PM PDT

To give a specific example, I was watching a video of an animation of DNA replication (https://www.youtube.com/watch?v=7Hk9jct2ozY&list=PLD0444BD542B4D7D9&ab_channel=WEHImovies). How are the free nucleic acids necessary to build the DNA strands localised to the replication site?

In general, this is something that has always confused me about biology - it seems unfathomable that the "ingredients" necessary for these complex cellular processes are so readily available in such a huge and "dumb" cell - another example being tRNA for protein synthesis.

submitted by /u/natpat
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How is the rate of infection calculated in diseases like Mers, Sars and Covid-19?

Posted: 24 Mar 2022 04:25 AM PDT

What happens to matter when disolved in acid?

Posted: 24 Mar 2022 03:56 AM PDT

On a molecular level, do atoms just cease to exist? Are they added to the acid? What happens?

submitted by /u/Kreagerrr
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What happens in our brain that causes up to wake up naturally?

Posted: 23 Mar 2022 12:45 PM PDT

Inspired by my napping toddler. I am always doing mental calculations about how much is "enough" sleep. Obviously it seems like a good gauge of "enough" is if she wakes up naturally by herself. But of course she sometimes wakes up naturally when it's clear that she is still tired.

What is the trigger in our brain that wakes us up in the absence of external noise, light, etc.?

submitted by /u/steadyachiever
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What is the mechanism for severe tachycardia (>180 bpm) in DKA?

Posted: 24 Mar 2022 09:53 AM PDT

Would a rate this high only result from a reentrant rhythm? Or is it a sinus tachycardia from a combination of metabolic demand, dehydration, and catecholamine release? How high can the SA node actually pace?

submitted by /u/mister305worldwide
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Why are inactivated vaccines generally less effective than live-attenuated vaccines?

Posted: 23 Mar 2022 07:57 PM PDT

I would think that both forms of the vaccine would display the same antigens on the surface, so what could make live-attenuated vaccines much more effective?

submitted by /u/onyxperihelion
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Most eggs we buy are unfertilized, i.e. they will not hatch chicken. Can hens distinguish between fertilized and un fertilized eggs? Or do they sit on either type and get disappointed after sometime.

Posted: 23 Mar 2022 09:05 AM PDT

Most eggs we buy are unfertilized, i.e. they will not hatch chicken. Can hens distinguish between fertilized and un fertilized eggs? Or do they sit on either type and get disappointed after sometime.

submitted by /u/kunalkhatri
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Wednesday, March 23, 2022

Why do all storms dissipate eventually?

Why do all storms dissipate eventually?


Why do all storms dissipate eventually?

Posted: 23 Mar 2022 05:13 PM PDT

Why can't the earth get its own perma-storm like Jupiter's Great Red Spot? Is it because of the fact that the earth has land masses that affect cold/warm and dry/humid air distribution? If so, would the southern latitudes be more conducive to long-lasting, powerful storms as there is less land mass over there? What limits how long a storm can last, how stable a storm system can be, and how powerful it can get?

Thanks!

submitted by /u/MoiJaimeLesCrepes
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Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Posted: 23 Mar 2022 07:00 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Economics, Political Science, Linguistics, Anthropology

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here. Ask away!

submitted by /u/AutoModerator
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Plenty of animals produce highly acidid fluids (e.g. stomach acid). Do any animals produce highly basic fluids?

Posted: 22 Mar 2022 10:38 AM PDT

Does breathing salty air dehydrate you more than inland air?

Posted: 22 Mar 2022 06:17 PM PDT

I'm wondering if the salty air when near the ocean, or on a boat can dehydrate the human body faster than if you were away from the ocean. Also, what amount of concentration of salt is in the air that you're breathing. Many times I have found piles of salt in my bags, when on a long voyage on a boat. Thanks for the information anyone can give me!

submitted by /u/Natepeeeff
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Why do pain relievers (NSAID/acetaminophen) relieve chronic pain while seemingly not affecting acute pain?

Posted: 22 Mar 2022 10:27 AM PDT

On the rare occasion I have a headache, I'll often reach for a Tylenol to help relieve the pain.

Usually this is relatively effective. Either it'll eliminate the pain completely or reduce it to a much more manageable level.

Yet, even under the effects of something like Tylenol or Ibuprofen, if I were to say, pinch my arm, I'd still feel essentially the same amount of pain as normal.

Is there a biochemical reason for this? Is there a difference between acute and chronic pain? Or is there perhaps some psychological component to it?

submitted by /u/kherven
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If colorblind people with protanopia do not perceive red, then why, if they are placed in a dark room and a red LED is directed at them, will they see light?

Posted: 23 Mar 2022 03:31 AM PDT

If colorblind people with protanopia do not perceive red, then why, if they are placed in a completely dark room and a red LED is directed at them, will they see light? After all, red, in theory, should be outside their visible spectrum and work as infrared light for a person with normal vision (to be invisible)?

submitted by /u/AngryMonkey39
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Is there a study on the average/ most common answers for the original Rorschach test?

Posted: 22 Mar 2022 06:56 PM PDT

Why can't batteries be charged faster? Is it just because the heat accelerates dendrit formation?

Posted: 22 Mar 2022 06:01 PM PDT

Do animals masturbate MORE while in captivity?

Posted: 22 Mar 2022 07:22 PM PDT

What are the landmarks of the foot bone?

Posted: 22 Mar 2022 06:21 PM PDT

I am really interested in bone anatomy and have tried googling this question, but got some different answers. I learned there are 15 bony landmarks of the foot, so would anyone know the exact names of them?

submitted by /u/rainynoodles
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Would a monitor lizard (or other egg loving creature) prefer to eat a fresh laid egg with the yolk or one that was nearly ready to hatch? which would be more valuable as food?

Posted: 22 Mar 2022 07:31 PM PDT

How do astronomers measure planets, galaxies, etc?

Posted: 22 Mar 2022 09:35 PM PDT

Is nicotine itself, in lower doses, actually that harmful to the body? Is it just the forms in which it is administered?

Posted: 22 Mar 2022 04:04 PM PDT

I've heard that nicotine itself is a poison, but what is the main cause of carcinogens or cancer inviting effects commonly associated with using nicotine? If someone were to inject the same amount of nicotine as what they would get in their usually vape/smoke break, would there be any noticeable long or short term negative consequences?

submitted by /u/imforry
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Why is milk in liquid state and beef in solid state although they are both high in protein and have high water content(7~80%)?

Posted: 23 Mar 2022 04:53 AM PDT

I can't catch a clue of this question. I've also searched water activity of these two but they were almost similar (0.99). Is it related to some concepts like water holding capacity or structure of protein or free/bound/entrapped water?

submitted by /u/More-Bill5236
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Can you culture neurons?

Posted: 22 Mar 2022 05:06 AM PDT

If you can't, can you use a virus to change their DNA to make it possible?

submitted by /u/ripMyTime0192
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