Wikipedia:Reference desk/Archives/Science/2017 October 20

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

October 20

What is a "nucleated brain"?

I'm auditing a class on Evolution of the Human Brain. Most of the people in the class have a much deeper knowledge of biology than I do so there are some questions I feel aren't appropriate to ask (or I'm egotistical and just don't want to look dumb). A while ago some people here helped me out with a question I had about neurotransmitters. Here is another one. Every once in a while when the professor is talking about non-human animals, and also (I think) about non mammals he says they have "nucleated brains". In a recent lecture talking about the history of early neurobiology and the work of Marie Jean-Pierre Flourens on birds he said (reconstructed from notes but I think this is accurate):

"the more telencephalon was damaged the more the animal was impaired... he said that the size of the ablation correlated with the extent of the problem but the localization within the telencephalon didn't effect specific functions... it [the bird brain] is not organized in maps the way the mammal brain is, remember that the bird brain is NUCLEATED, damage to the bird brain is not going to be as localized as in mammals"

I get the point that mammal brains are more likely to show damage to specific functions due to where a lesion occurs (e.g. vision in one area hearing in another) but I don't understand what the professor means when he says that bird brains (and I think he says this of all brains that don't have cerebral cortex, i.e., most non mammals) is nucleated. I looked up nucleated and found the definition for individual cells but I don't think that is what he means here. --MadScientistX11 (talk) 17:45, 20 October 2017 (UTC)

Nucleus (neuroanatomy)? --Jayron32 17:48, 20 October 2017 (UTC)

I think the basic distinction here is between brain areas where the neurons are organized into two-dimensional sheets and areas where they are organized as three-dimensional "nuclei". Actually all types of animals have both types of brain areas -- in mammals, for example, the cerebral cortex is layered but the basal ganglia have a nuclear organization. However, there are some areas of the bird brain that have a nuclear organization but appear to correspond with areas of the mammal brain that are layered. The most important example is the dorsal ventricular ridge, which is nuclear in structure but is thought, by at least some anatomists, to correspond to at least part of the mammal cerebral cortex. Looie496 (talk) 19:07, 21 October 2017 (UTC)

(Wow, how can that be a red link? Gotta fix that! Looie496 (talk) 19:09, 21 October 2017 (UTC))

@Looie496: thanks, I think that is the point. I think I understand about layering in two dimensional sheets -- I assume an example would be layers V1, V2, etc. in the visual cortex(?) but didn't know about the three dimensional "nuclei". I had to miss one week (had a consulting gig, still need to pay the bills) and I think I missed the week he discussed that. But whenever it comes up he's always talking about the difference between bird and reptile brains vs. mammal brains and also talking about areas such as the basal ganglia. This was very helpful, I think I have enough to follow up on my own. thanks much! --MadScientistX11 (talk) 04:51, 24 October 2017 (UTC)

Death toll due to anti-vaccin movement

I am looking for reliable sources for this number. I have located this, however, it does not cite any source.

An ideal account would be based on death toll in the industrialized countries only from preventable disease, because that's where vaccines availability is high so any death due to preventable-by-vaccine disease is sure to be through lack thereof. אילן שמעוני (talk) 18:53, 20 October 2017 (UTC)

Have you looked at the FAQ section of the page you pointed at? It is got at by a link at the top. It seems to use the sorts of sources you talk about. Dmcq (talk) 19:21, 20 October 2017 (UTC)

Thank you! I have missed that. אילן שמעוני (talk) 21:54, 20 October 2017 (UTC)

There are age limits to giving vaccines, possible failure to develop or sustain antibodies and also cases of immune-system deficiency and allergies which may prevent vaccine usage even where the is high vaccine availability which are reasons that herd immunity is important. We cannot be certain a death from a vaccine-preventable disease is due to anti-vax intentions. Rmhermen (talk) 17:07, 21 October 2017 (UTC)

While true, the best way to estimate the damage is comparing the number of deaths from preventable disease (through vaccines) before and after the anti-vaccine movement. The figures I located so far suggest 2 magnitudes increase, which make the CDC numbers reliable with only few percents margin. Thanks for the input. אילן שמעוני (talk) 18:27, 22 October 2017 (UTC)

Zero because the anti-vaccine movement doesn't physically prevent anyone from getting vaccinated. They do make propaganda, but they don't have control over the media. So, if people end up not getting the vaccines they need, it is because they didn't get the right education in school. It's not because stupid people are saying stupid things, because that's a factor that's always in play. Count Iblis (talk) 04:05, 22 October 2017 (UTC)

Misinformation is going to have an effect, no matter how well educated people are to begin with. Unfortunately, the way people judge things to be true is mostly based on how often they hear it, so if those sending out the misinformation manage to get more air time than those with the sensible but boring message, they will convince people. And if the crazy message happens to come from somebody famous, like a former TV actor or reality TV star, then they are even more likely to believe it. If it comes from somebody they never heard of, like a competent scientist, then they ignore it. StuRat (talk) 04:51, 22 October 2017 (UTC)

Could you leave out the guns don't kill forum type argument and stick a bit closer to the question like Rmhermen did thanks. Dmcq (talk) 10:16, 22 October 2017 (UTC)

The source is the Centers For Disease Control (see this and following tables [1]) as its source. They also mention that not all death can be computed as caused by anti-vaxx movement. There are other reasons for not getting vaccinated (like being an illegal alien from a third world country). Hofhof (talk) 23:21, 22 October 2017 (UTC)