Agent Smith

2 hours ago, CharonY said:

It is not so much the inherent stability of the molecule that causes mutations, but rather the difference in copying the genetic material (which is more prone to errors in RNA viruses for a variety of reasons).

Si, that's correct. Could one reason be that RNA isn't protected by complementary strand pairing like DNA? ssRNA I know exists, but dsRNA, my files return null.

Quite possibly it's more correct to say [math]s < n \iff P(all \space numbers \space deleted) = 0[/math]

10 hours ago, CharonY said:

The mechanisms are actually known and is largely related to their replication mechanism. RNA viruses, including poliovirus have fairly high mutation rates and SARS-CoV-2 is actually on the lower end for RNA viruses. Conversely, poliovirus is on the higher end of the scale. Conversely, poliovirus has a much smaller genome (7.5 k vs 30k). 

The reason why we have so many SARS-CoV-2 variants is likely related to yet another factor, namely the fact that so many people have been infected. For example, at the peak of polio outbreaks in the USA ca. 50k individuals were found to be infected in a year. At the peak of the SARS-CoV-2 pandemic, the USA had over 900k cases per day.  The high circulation ultimately means more mutations and higher chance of positively selectable traits. 

Perhaps due to their usual function/purpose, RNA is more unstable than DNA. 🙂

For [math]n[/math] random numbers, [math]P(all \space numbers \space deleted) > 0 \iff s \geq n[/math]

That's on target, but not all viruses are like that. Per my files (rather outdated), the polio virus has not undergone any significant mutation in the last 50 or so years, at least none that would affect the efficacy of the 2 vaccines that are around (one live, the other killed). I wonder why some viruses have such high degrees of genomic instability. There origins too remain a mystery, to me at least. 

Would I be correct if I said that if we make radio contact now, the alien civilization has to be on/within a radio bubble that has a maximum radius of 4.5 billion light years?

On 2/13/2023 at 12:29 PM, MonDie said:

Psychology is categorically obscure, but reducing psychology to brain imaging is like reducing physics or biology to telescopy or microscopy.  Quantifying the content of communication should matter.

Neuroscientists, like all scientists, rely on the reliability of a basic willingness to communicate.  Psychologists and anthropologists quantify not only communication, but communication patterns and ability, and the emerging social behavior and cultural activities.  You can ignore good communication when it works and superfluous communication when it's insubstantial, but don't forget that bad communication will waste resources, time, cognition, public trust, and everybody's credibility.  Of course, that might seem insubstantial to a narrow-minded person awaiting a paycheck.

How about any logical framework of mental representation, adaptive behavior, or verbal communication that mutually reinforces the data analysese? 

Looks like a good place to build a launch pad. 

On 2/5/2023 at 4:26 PM, MonDie said:

Psychologists use experimental and mathematical techniques to more precisely quantify the relationships among the observable variables that are only passively observed by the layman, like personality traits for instance. If the development of a reliable and precise measurement tool isn't scientific, then what is? But the layman might not understand the math, and what is psychology separate of these mathematical techniques if there isn't any unifying psychological theory that unites the discipline of psychology? This can make it seem more like a massive data collection operation than a scientific endeavor.

Or Behavioral Ecology bolstered by the occasional MRI data.

 

Most measurement tools are trained on ordinary people whom the rater already can intuitively understand.  Yet, the most extreme aberrations are the source of the most intrigue and the most worry, and they may have nothing to teach, especially if they're lying.  Nature doesn't lie, nature isn't machiavellian. 

Many would probably fancy themselves to be the real psychologist in the room.

What's this unifying psychological theory you refer to?

On 1/20/2023 at 9:00 PM, Genady said:

One can get many inconsistencies if one mixes freely these two different models. To be consistent, one should not generally do it, although it works sometimes if applied very carefully and in a restricted domain.

In particular, if you use Newtonian perspective, then there is no speed limit. And if use GR, then the galaxies do not move faster than light. Each picture is consistent within itself. 

So Newton is inconsistent with Einstein. So, depending on the theory we use, either no work is being done or some work is being done. 🧒

On 1/20/2023 at 9:00 PM, Bufofrog said:

No, the galaxies are not moving away from us through space at that speed. 

 The galaxies are not moving through space at that speed relative to us so the KE equation you presented does not apply.

Thank you for the reply

38 minutes ago, Genady said:

No, it is not.

A Newtonian perspective would need to find an energy source causing the observed acceleration of galaxies. You said above that there is no mass, but this is not so. Galaxies have mass.

You've also said above that the universe expansion is "space stretching", but it is not so from a Newtonian perspective. It is so from the GR perspective. 

Some of these galaxies are moving away from us at speeds exceeding the speed of light I believe. Does that mean anything? Hence the space stretching patch I suppose. From Newton's perspective then the kinetic energy of some of these galaxies = [math]\frac{1}{2}mc^2[/math] which in Einstein's theory should be impossible. 

30 minutes ago, Genady said:

But we already have a correction to Newtonian perspective. It is GR. Newtonian perspective doesn't work in this domain.

So, from a Newtonian perspective, dark energy is a wild goose.

46 minutes ago, Genady said:

Why? Is there a problem?

From a Newtonian perspective yes. Kindly go through the thread, it's short.

On 1/19/2023 at 1:04 AM, Genady said:

AFAIK, expansion of the universe is a GR effect, and it cannot be consistently described in term of Newtonian mechanics. Specifically, there is no Newtonian 'F' in GR formulation.

Einstein field equations, EFE, relate geometry of spacetime (LHS of the equations) with distribution of energy-momentum in the spacetime (RHS). To get an accelerated expansion in these equations, you need either an extra term on the LHS or an extra term on the RHS. The former leads to inclusion of a "cosmological constant" in the EFE. The latter leads to inclusion of a peculiar energy source in the universe, the "dark energy."

Could we be on a wild goose chase?

8 hours ago, Genady said:

If any line is unclear, let me know

I would like an intuitive explanation also please, if possible. 

I've noticed the word "independent" appears in almost all answers to this question. What does it mean exactly and how does [math]F \propto m[/math] independent of mass and [math]F \propto a[/math] independent of acceleration lead to the conclusion that [math]F \propto ma[/math]

On 5/4/2022 at 7:02 PM, Genady said:

1. F=xm where x does not depend on m

2. F=ya where y does not depend on a

3. F=xma/a=ya

4. y=xm/a

5. since y does not depend on a, xm/a does not depend on a

6. x/a does not depend on a

7. x=za where z does not depend on a or on m

8. F=zma

@Agent Smith

Can you explain a little bit more about how the constants being independent of acceleration and mass matter to understanding this rule that if ...

[math]n \propto q ~ \& ~ n \propto r, then ~ n \propto qr[/math]

On 6/15/2022 at 11:11 AM, uncool said:

And the only way that can happen is if f(a)/a = g(m)/m is constant - is independent of both mass and acceleration.

Thanks a million. I got most of what you said except the part quoted above. 

43 minutes ago, Janus said:

Dark energy is not required for the universe to expand, it is needed to explain why the rate of expansion has been increasing over time.

The original assumption was that, starting from some initial impetus, the universe began to expand, and that over time, the mutual gravitational attraction of its matter would slow the expansion rate. 

From this there were two possibilities:

1. Gravity would eventually win, the universe would stop expanding and then collapse back in on itself.

2. The universe didn't have quite enough mass to stop the expansion completely, and it would continue to expand forever.

The study that opened the whole dark energy can of worms was trying to determine which of these was true.

What they did was measure the recession velocity of various galaxies at various distances.  Since the further a galaxy is from us the longer it took its light to reach us, you were looking further and further into the past as you looked at more and more distant galaxies.

You then plot a distance/recession graph.  If the rate of expansion had been constant over time, you would get a straight line. Of course, this was not what they expected to see, they expected to get a curve, the degree of which would indicate how fast the expansion was slowing. 

They got a curve, but one that curved the opposite direction, indicating that the expansion rate had increased over time.  Something was causing it to speed up.

They settled on calling it "dark energy" just for the simple fact that the term "dark matter" had already been in usage (And this is the only thing the two have in common).

As to the exact nature of dark energy, it is still an unsolved mystery.

Okay Work = Fd 

F = ma

Work = mad 

The expansion is acclerating, but there's no mass i.e. Work = 0 × a × d = 0 joules.

From what I know, dark energy is the posited energy driving cosmic expansion. This seems to imply cosmic expansion is work (requiring energy), but then I was told cosmic expansion is the space stretching and space has no mass. How is work being done in cosmic expansion when no mass in involved, a work that requires dark energy?

2 hours ago, Bufofrog said:

That is correct.  I'm not sure how the method that yeast use to reproduce is related to the OP.

Last I checked, they reproduce by budding.

Heat denatures proteins i.e. it disrupts their structure which as you know means proteins lose their function. HSP's, probably by binding to proteins, make them, in a sense, heat-resistant.

Que sais-je?

On 6/8/2022 at 11:25 AM, deappri said:

two genotypes D/D and D/d are Rh+ and d/d is Rh-. The frequency of Rh- people in the population is about 16/100.

DD & dd OR Dd & dd

1. DD & dd: Dd or Dd or Dd or Dd (all Rh+)

OR

2. Dd & dd: Dd or Dd or dd or dd (2 Rh-)

P(Rh-): 2/8 = 1/4 = 25%

5 hours ago, dimreepr said:

How about fear? Is that a mental illness?

If someone like Putin learns to fear, is he mental or ambivalent? 

We'd have to first work out what mental illnesses are. Then see if fear fulfills any criteria for a particular psychiatric malady.

4 hours ago, Peterkin said:

You think so? For two months I was convinced I had an impacted salivary gland. An acquaintance (met while undergoing radiation) was convinced she was cancer-free following extensive treatments, only to die of an undiscovered liver metastasis a month later. Cancer can be pretty tricky, too.

Diagnosing physical illnesses is much easier and more precise than mental ones. 

11 hours ago, Peterkin said:

I'm leery of words like 'claim'; it's pejorative by association, but too general to answer. Doctors and nurses working in that area have their own vocabulary, like every other professional community. Recently, the trend has been more toward naming in English, rather than Latin or German, so that it's easier to communicate with caregivers, relatives and the patient himself. Mental illness is difficult to classify and codify, yes; lots of grey areas. Cancer hasn't been cured yet, either, and nobody's picking on surgeons or radiologists. It's just harder to troubleshoot software; always will be: brains are more fragile and complicated than bones. Have you tried turning it off and on again? Sometimes that actually works. Psychology and neuroscience are still quite young, growing and adapting - but at least we no longer execute soldiers who suffer from PTSD.

I have some idea how schizophrenia was/is diagnosed.

Look for cardinal symptoms like, as per Eugene Bleuler, autism, ambivalence, inappropriate affect, loosening of association. How exactly these are determined to be present in a suspected schizophrenic is an unknown to me.

11 hours ago, Sensei said:

Cancer, at least you know you have it or not..

Indeed!

2 minutes ago, Peterkin said:

Actually, that is the branch of which I'm most skeptical. I have never been particularly well versed in clinical psychology; my only experience is in counselling college students. The heavy stuff, I only know at second hand, from the patient's side: two close friends with long-standing mental issues who have tried a number of approaches over the years. Approaches, rather than treatments; it's really not like mainstream medicine. I understand hardware pretty well; I'm comfortable in most hospital departments. The psych ward, though, behind the closed doors with wire mesh in the glass panels... that's another country - which, I suppose, is why so many people are reluctant to acknowledge it.

The more interesting condition to me is chronic depression. It's a bitch of an illness: it turns bright, talented, interesting people into morbid slugs. And I'm glad somebody's willing to help them - I don't care if it's a priest, a psychiatrist or a voodoo mambo!  Not every approach works - not by a long chalk! And what works for one person might be no use to somebody else. There are some constants, but successful therapies are usually arrived-at through trial and error.

The other friend has ADHD, well controlled now, with a combination drug and personal routine regimen. As a child in the late 50's, he was called hyperkinetic and there was very little anyone could do for him, except the exercise I mentioned earlier. He should have become a great soccer player - except that he literally could not keep his eyes on the ball.  Since the medical and educational establishments have been taking the problem seriously, he's had considerable coaching in how to manage the symptoms himself, so that he can live a normal life.

Interesting. Pathophysiological description of mental illnesses consist of many claims that could be, in principle, rephrased so to speak in terms familiar to a doctor/nurse.  This however hasn't happened.