Monday, 3 May 2021

A short history of Sex Chromosomes

In 1890, the X and Y chromosomes were discovered. It was found that the men who were tested had 46 chromosomes, including an X and a Y, while women who were tested also had 46 chromosomes, including 2 X chromosomes. 

So obviously the conclusion was that the Y chromosome defined masculinity. A reasonable conclusion. 

 Fast forward 50 years... and it was found that some men had 47 chromosomes, including 2 X's and a Y, while some women had 45, including only one X. Still no problem with the "Y chromosome defines masculinity" idea.

 Then... it was found that fully 1 in 300 men weren't 46,XY. Some women were. 


 After DNA was discovered in the 50s, it was found that the SrY gene, usually found on the Y chromosome, sometimes was missing. And sometimes had been translocated to another chromosome, hence 46,XX men and 46,XY women. So SrY defined masculinity. Whew!

Then.. it was found out that some men didn’t have an SrY chromosome, not anywhere. Some women did. Other genes were involved sometimes.

Oops again.

. Worse, other factors, such as Androgen Insensitivity made 46,XY people female, and Congenital Adrenal Hyperplasia masculinised 46,XX people. 

Then in the 70s, other syndromes, such as 5alpha-reductase-2 deficiency were identified, which caused babies to look like one sex at birth, then the other at ppuberty.Even worse, in some places 1 in 50 infants had this natural sex change, it was not rare there. 

 Science 1974 Dec 27; 186 (4170): 1213-5

 In an isolated village of the southwestern Dominican Republic, 2% of the live births were in the 1970's, guevedoces....These children appeared to be girls at birth, but at puberty these 'girls' sprout muscles, testes, and a penis. For the rest of their lives they are men in nearly all respects.

 In the 90s, it was found that hormonal hiccups in the womb caused some parts of the body to develop as one sex, othersbas the other, regardless of genetics.

Male–to–female transsexuals have female neuron numbers in a limbic nucleus. Kruiver et al J Clin Endocrinol Metab (2000) 85:2034–2041 

 The present findings of somatostatin neuronal sex differences in the BSTc and its sex reversal in the transsexual brain clearly support the paradigm that in transsexuals sexual differentiation of the brain and genitals may go into opposite directions

 It's a matter of timing during foetal development.

 Sometimes a boy is born looking like a girl, sometimes a girl is born looking like a boy, regardless of chromosomes. 

This is complex stuff. We don't teach the Theory of General Relativity in grade school, Newtonian physics, or at most Special Relativity (far simpler than General) is enough. Similary, "XX is female, XY is male" is good enough unless you do medicine or biology in college.

 It's only really relevant when talking about Trans or Intersex people, just as Relativistic effects only become relevant in the domain of the very big, very small, or very very fast, close to 186,000 miles a second.

 People do *not* need psychiatric help when they think that things get heavier, more massive, as they go faster... while lengths contract. People do *not* need help when they think their sex is something different from their genetics.

 Intersex people exist. Trans people exist. They are unusual, so trying to apply the usual approximations is as silly as trying to apply Newtonian physics to things moving close to or at light speed. Legislating such things is as insane as legally ruling that Pi=3... as has been done in the past.

Sunday, 17 January 2021

Masks - from the Journal of Hospital Infection


Dismantling myths on the airborne transmission of severe acute respiratory syndrome coronavirus (SARS-CoV-2)

Tang et al, Journal of Hospital Infection, Jan 2021 pre print

Several laboratory studies have already shown that surgical and home-made masks are somewhat (but incompletely) effective in both limiting exhaled particles, and in protecting wearers from inhaling particles from others. Surgical masks can contain, and therefore reduce, the dissemination of viruses shed by an infected wearer by up to 3-4-fold (i.e. ∼67-75%), and even 100% in the case of seasonal coronaviruses., When an infectious person wears a mask or face covering, the size of the exhaled plume is also reduced and this also helps to reduce the risk of exposure to those nearby.
Surgical masks also protect the wearer, by reducing the exposure to incoming droplets and aerosols from infected individuals by an average of 6-fold (range 1.1 to 55-fold)., The filtration capacity of surgical masks in the micron size range is often considerable, although it varies between brands. We know that the filtration capacity of N95/FFP2 respirators is better if they have been appropriately fit-tested, to avoid leakage of aerosols around the side of the respirator into the breathing zone.
Even home-made cloth masks (made from tea cloths or cotton t-shirts) can reduce the exposure from incoming particles by up to 2-4-fold (i.e. ∼50-75%).
This mainly depends on how the mask is made, what materials it is made from, the number of layers, and the characteristics of respiratory secretions to which it is exposed. Based on the evidence supporting a role for airborne transmission of COVID-19, the use of N95/FFP2/FFP3 respirators by frontline healthcare workers should be recommended. For those that cannot tolerate wearing these masks for long periods, the less restrictive surgical masks still offer some protection, but it needs to be acknowledged that these won’t be quite so effective

Saturday, 9 January 2021

Meet Elizabeth from Knoxville Tennessee who stormed the Capitol.

Treason doth never prosper, what's the reason? For if it prosper, none dare call it Treason.

Corollary: it's only a Revolution if you win. Otherwise it's Treason. Really. Not joking.

Worse, in the US, if someone was killed during the course of a crime, everyone involved in the commission of that crime is guilty of homicide. Even lookouts or getaway drivers who had no direct connection with the death. As icing on the cake, if the person who died was a law enforcement officer, all those involved are deemed "cop killers" and hunted without mercy. One Capitol policeman died from head injuries after one of the mob bashed him with a fire extinguisher.

This naive idiot is about to find out that in real life, actions have consequences. Legal ones.

 The crime of Treason in the US is very, very rarely charged. The bar is set very high. However, the Death Penalty is on the table if found guilty. I hope this child in a woman's body gets good legal representation, and that the prosecutor is not out for blood. Literally. If she's really unlucky, she'll  be tried as if she were Black.