Wikipedia:Reference desk/Archives/Science/2017 December 16

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December 16

What is the opposite of Nootropics?

Nootropics are defined as memory enhancers. Then my question is what is the name of those substances that cause to forgetfulness? 185.191.178.183 (talk) 09:51, 16 December 2017 (UTC)

Amnesics. Looie496 (talk) 16:08, 16 December 2017 (UTC)

Interesting. I didn't find usage of this word for substances that cause loss of memory or forgetfulness. Can you show me please where there is a source for that? 185.191.178.183 (talk) 19:07, 16 December 2017 (UTC)

The word amnesic is normally used as an adjective (and very rarely as a synonym for amnesiac), but I can imagine that someone somewhere has used it as a noun meaning amnesic drug (but I can't find anywhere other than Bill's usage above). Dbfirs 21:00, 16 December 2017 (UTC)

It is used with that meaning in the SCP Foundation fictional universe, though I think the more common term is "amnestic". In either case, it denotes a drug used to erase memory (like a pharmaceutical equivalent of the device in Men in Black). 169.228.159.225 (talk) 21:18, 16 December 2017 (UTC)

Ah, yes, "An amnestic is an amnesia-inducing agent that can take many different forms", but use of the noun in a fictional universe does not qualify the neologism for a dictionary entry until it escapes into our universe (as it may well do in future). As an adjective, amnesic is more common than amnestic. Dbfirs 22:00, 16 December 2017 (UTC)

• There is anterograde and retrograde amnesia. Midazolam is used intentionally as part of mild sedation to produce anterograde amnesia. Propranolol administered when a traumatic memory is recalled can help disassociate the memory from the traumatic emotional aspect of it. There is, according to Harvard, just normal forgetfulness as well. And many drugs have the undesired effect of retrograde amnesia, including, e.g., Cholesterol-lowering drugs (Statins) ...Antiseizure drugs. ...Antidepressant drugs (Tricyclic antidepressants) ...Narcotic painkillers. ...Parkinson's drugs (Dopamine agonists) ...Hypertension drugs (Beta-blockers) μηδείς (talk) 02:40, 17 December 2017 (UTC)

The benzodiazepines, like midazolam, and other classes can be described as 'amnestic drugs' in scientific articles like:

• Galizio, M; Mathews, M; Mason, M; Panoz-Brown, D; Prichard, A; Soto, P (November 2017). "Amnestic drugs in the odor span task: Effects of flunitrazepam, zolpidem and scopolamine". Neurobiology of learning and memory. 145: 67–74. doi:10.1016/j.nlm.2017.09.006. PMID 28893667.
• Han, CJ; Pierre-Louis, J; Scheff, A; Robinson, JK (1 September 2000). "A performance-dependent adjustment of the retention interval in a delayed non-matching-to-position paradigm differentiates effects of amnestic drugs in rats". European journal of pharmacology. 403 (1–2): 87–93. PMID 10969148.

Klbrain (talk) 00:26, 18 December 2017 (UTC)

on sugars and carbohydrates

I was told that carbohydrates are sugar (the white sugar). Now if there is a product without sugar, but it has carbohydrates, does it mean that these are same as sugar? then in the end of the day, carbohydrate has influence on the body the same as sugar, and from both should be avoid. Isn't it? --185.191.178.183 (talk) 09:56, 16 December 2017 (UTC)

Sugar is a specific type of carbohydrate. Carbohydrates, protein and lipids are the 3 different classes of substances that the body can derive caloric value from. All three are part of a balanced diet. Simple sugars sometimes can sometimes be metabolized faster than starches or other carbohydrates but avoidance would only be necessary if other health issues are present. --DHeyward (talk) 10:14, 16 December 2017 (UTC)

As a slight caveat, the body can derive caloric value from several other substances, most notably ethanol. Looie496 (talk) 16:12, 16 December 2017 (UTC)

Ethanol contains carbon, hydrogen and oxygen. That would make it a carbohydrate.--Phil Holmes 17:26, 16 December 2017 (UTC)

That's incorrect. Carbon, hydrogen and oxygen are the fundamental elements of organic life and are not an indicator of being a carbohydrate. --DHeyward (talk) 04:09, 17 December 2017 (UTC)

I'm just trying to understand the pathophysiology of diabetes melitus for example that it has to do with high levels of sugars in the blood. Now, if all carbohydrates are sugars, and white sugar is the same as carbohydrate in the end of the day (because any carbohydrate become to glucose (C6H12O6)) so why does it matter if a specific food has sugars or carbohydrates, they are the same! and a person who never touched white sugars can get DM (type 2 of course) just from consuming carbohydrates (such as 'natural' bread which contains flour and water only) Isn't it? 185.191.178.183 (talk) 10:44, 16 December 2017 (UTC)

Have you read carbohydrate, sugar, glycemic load, glycemic index, diabetes mellitus type 2, low-glycemic diet, etc.? Those articles would be a better place to start.--William Thweatt ^TalkContribs 10:58, 16 December 2017 (UTC)

• There are many different types of simple (glucose, fructose) and disaccharide sugars; lactose (made of galactose and glucose), sucrose "table sugar" (made of glucose and fructose). And there are starches and fibers which are more and less digestible chains of sugars/carbohydrate. So it's a common error, but wrong to think that table sugar is the basic type of sugar.

The body converts carbohydrates to glucose for transport by the blood and as a general fuel source in normal conditions. The main problem in diabetes II is carbs with, as William mentioned, high glycemic loads/glycemic index. Eating significant amounts of simple sugars or easily digested starches (the saliva digests starch) can cause glucose spikes, and glucose reacts with proteins in the body causing direct and indirect damage to tissues and blood vessels, especially in the kidneys, eyes, and extremities.

I am a type II diabetic, and although it is in total remission now, after I lost over 1/3 of my body weight with medical treatment (a good endocrinologist working with a nutritionist and a gastric sleeve surgeon basically saved my life) even when my diabetes was full blown, I could eat beans and whole corn without getting spikes. Even though those foods were high in carbs, they were of the kinds that are difficult to digest and are very slowly released to the bloodstream, if at all, before being excreted by the bowel.

So, not all carbs are equal, nor are they identical to table sugar. There are diagnostic tools (blood glucose and A1c tests, regular physical exams, and symptom reviews (like thirst and frequent urination) as well as excellent medicines, procedures and regimes to treat the issue if a medical professional recommends it. See a physician if you have any concerns. μηδείς (talk) 17:53, 16 December 2017 (UTC)

Thank you. It's not about medical concerns. The issue is that a lot of health people avoid the use of sugars (sucrose) but they don't know that in the end of the day carbs are become glucose (C6H12O6) and I wondered why they should avoid sugars while they eating carbs. But now I understand from your answer that the problem is not the glucose but the rate of the absorption of ant carbs, meaning that sucrose is absorbed fast (high glicemic index) and therefore it causes spikes (=hyperglycemia?) and resulting in many diseases that made by high level of glucose in the blood. Therefore, any carb with high glicemic index is the same (or worse than) as sucrose. For example the GI of sucrose is 68 while French baguette has 95 GI! therefore in this case it's better to eat sucrose than French baguette. So in the end of the day everything is about GI, and the way of absorption. Did I get you properly? 185.191.178.183 (talk) 19:04, 16 December 2017 (UTC)

My pleasure. You understood me correctly; yes hyperglycemia is the proper term. As an aside, my nutritionist suggested I try to give up coffee to deal with my regularity; that wasn't happening. Then she suggested almond milk, which I love, instead of cow's milk, since she suspected maybe I was lactose intolerant. But there was no difference after going off lactose (which I have tried before to no effect), and almond milk has only 1/8th the protein content of skim milk at almost twice the retail price. So I told her I would compromise, and now I add a baguette to my coffee rather than a teaspoon of sugar. :) μηδείς (talk) 19:46, 16 December 2017 (UTC)

Thank you. I couldn't think that it can be so easy to understand. Now my goal is to understand how the GI is determined for foods. 185.191.178.183 (talk) 20:24, 16 December 2017 (UTC)

Well, googling "how is the glycemic index calculated" gives the featured result that it is measured by monitoring the blood after the "consumption of test foods" aswell as lots of links. It seems rather odd to think you'd have enough volunteers to do that, especially for unpatented foods where there's no corporate monetary incentive. I suspect there's a lot of fudging and interpolation being done.

In the 80's, my chemistry teacher advised us that they actually measured the caloric content of foods by burning them in a bomb calorimeter. We did an experiment where we burnt a sugar doughnut. The hypothesis was that the experimental result would be higher than the actual metabolic result, given not all that is burnt is efficiently digested. So we obviously were getting proxy results maybe good by an order of magnitude. That may have been a holiday "lab", like when we made peanut brittle under the guise of studying caramelization as an oxidative process on the last day before winter break. μηδείς (talk) 21:14, 16 December 2017 (UTC)

A key thing to bear in mind here is that polysaccharides are made up of simple sugars and often digest quite readily to them. However, there are exceptions like cellulose and insoluble fiber that are put together in a way that isn't readily undone. Oddly, something as simple as allowing pasta to cool and reheating it later [1] reduces the glycemic effect. Bear in mind that much of the effect is related to how polysaccharides crystallize rather than the actual chemical difficulty of breaking the bonds -- a little acid or base (I think) can break down starch or cellulose to sugar (wood sugar wood hydrolysis [2]) though it is not to be recommended. Converting one sugar into another, even though they have the same formula, is not a simple process! So fructose has different (generally bad) effects on diabetes compared to glucose, for example. Other sugars like erythritol are used as calorie-free sweeteners because they don't get converted at all. (though actually that has a different formula, smaller sugar) Wnt (talk) 15:50, 17 December 2017 (UTC)

Safety in construction vs transport

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

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Why is safety not a top priority in construction, compared to in transport? 82.17.228.64 (talk) 11:31, 16 December 2017 (UTC)

Be aware that we don't answer requests for opinions, predictions or debate. Dolphin (t) 11:49, 16 December 2017 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

seashore crustacean ID (Southern California)

What is the crustacean this willet is eating? I took the photos in La Jolla, San Diego. 169.228.156.206 (talk) 19:49, 16 December 2017 (UTC)

Blepharipoda occidentalis, the spiny mole crab of So. Cal.

It looks very much like a mole crab, although the ones I am used to from the Jersey shore are a light blueish grey, and I am not sure what that long strand hanging down is, whether it's an appendage or damaged tissue or just debris. μηδείς (talk) 19:59, 16 December 2017 (UTC)

Yep, fits the pictured Western Spiny Mole Crab down to the color and oversized antennae compared to ours out East. These critters burrow in the sand at the tide level and filter food from the breaking and retreating waves. They can be dug up by children by the hundreds and in all sizes from fly-sized juveniles to fig-sized adults. μηδείς (talk) 20:04, 16 December 2017 (UTC)

I thought it might be a mole crab of the species you mention, though the long antennae (or whatever that is) looked odd. Thank you for the reply. 169.228.159.225 (talk) 21:03, 16 December 2017 (UTC)