@KatyMontgomerie @ElPolloDiabloX @AbigailShrier @chadfelixg Okay, so you haven't read the study in the British Journal of Sports Medicine, you've read a Guardian story about it.
I have now read the study, and I teach critical appraisal as part of my job, so let's dive into it a bit.

Roberts, Timothy A., Joshua Smalley, and Dale Ahrendt. "Effect of gender affirming hormones on athletic performance in transwomen and transmen: implications for sporting organisations and legislators." British Journal of Sports Medicine (2020).
More from Health
1/16
Why do B12 and folate deficiencies lead to HUGE red blood cells?
And, if the issue is DNA synthesis, why are red blood cells (which don't have DNA) the key cell line affected?
For answers, we'll have to go back a few billion years.
2/
RNA came first. Then, ~3-4 billion years ago, DNA emerged.
Among their differences:
🔹RNA contains uracil
🔹DNA contains thymine
But why does DNA contains thymine (T) instead of uracil (U)?
https://t.co/XlxT6cLLXg
3/
🔑Cytosine (C) can undergo spontaneous deamination to uracil (U).
In the RNA world, this meant that U could appear intensionally or unintentionally. This is clearly problematic. How can you repair RNA when you can't tell if something is an error?
https://t.co/bIZGviHBUc
4/
DNA's use of T instead of U means that spontaneous C → U deamination can be corrected without worry that an intentional U is being removed.
DNA requires greater stability than RNA so the transition to a thymine-based structure was beneficial.
https://t.co/bIZGviHBUc
5/
Let's return to megaloblastic anemia secondary to B12 or folate deficiency.
When either is severely deficient deoxythymidine monophosphate (dTMP*) production is hindered. With less dTMP, DNA synthesis is abnormal.
[*Note: thymine is the base in dTMP]
https://t.co/AnDUtKkbZh
Why do B12 and folate deficiencies lead to HUGE red blood cells?
And, if the issue is DNA synthesis, why are red blood cells (which don't have DNA) the key cell line affected?
For answers, we'll have to go back a few billion years.

2/
RNA came first. Then, ~3-4 billion years ago, DNA emerged.
Among their differences:
🔹RNA contains uracil
🔹DNA contains thymine
But why does DNA contains thymine (T) instead of uracil (U)?
https://t.co/XlxT6cLLXg

3/
🔑Cytosine (C) can undergo spontaneous deamination to uracil (U).
In the RNA world, this meant that U could appear intensionally or unintentionally. This is clearly problematic. How can you repair RNA when you can't tell if something is an error?
https://t.co/bIZGviHBUc

4/
DNA's use of T instead of U means that spontaneous C → U deamination can be corrected without worry that an intentional U is being removed.
DNA requires greater stability than RNA so the transition to a thymine-based structure was beneficial.
https://t.co/bIZGviHBUc

5/
Let's return to megaloblastic anemia secondary to B12 or folate deficiency.
When either is severely deficient deoxythymidine monophosphate (dTMP*) production is hindered. With less dTMP, DNA synthesis is abnormal.
[*Note: thymine is the base in dTMP]
https://t.co/AnDUtKkbZh

Sarcomeres in cardiac myocytes (heart muscle cells) are mechanically coupled to focal adhesions through dorsal stress fiber-like structures. #cardiotwitter #CellBiology
1/13
A thread based on Figure 1
A mature adult cardiac myocyte is packed with sarcomeres, whose contractile forces are coupled to the extracellular environment. With sarcomeres so close to the plasma membrane, how can we study the nature of this coupling?
2/13
Short answer: find a model system where the sarcomeres are not so close to what the cardiac myocyte is attached to. Enter, iPS cell-derived cardiac myocytes. These are “immature” in culture as they resemble fetal or neonatal cardiac myocytes.
3/13
Our previous work on iPS cardiac myocytes reported that sarcomere containing myofibrils assembled on the top surface of the myocyte.
https://t.co/xIBCu3hG1W
4/13
The sarcomeres seemed to be connected to focal adhesions on the bottom of the cell by thin actin bundles that resembled the dorsal stress fibers (DSF) commonly found in non-muscle cells. This movie steps through a Z stack of a myocyte starting at the bottom of the cell.
5/13
1/13
A thread based on Figure 1
A mature adult cardiac myocyte is packed with sarcomeres, whose contractile forces are coupled to the extracellular environment. With sarcomeres so close to the plasma membrane, how can we study the nature of this coupling?
2/13

Short answer: find a model system where the sarcomeres are not so close to what the cardiac myocyte is attached to. Enter, iPS cell-derived cardiac myocytes. These are “immature” in culture as they resemble fetal or neonatal cardiac myocytes.
3/13

Our previous work on iPS cardiac myocytes reported that sarcomere containing myofibrils assembled on the top surface of the myocyte.
https://t.co/xIBCu3hG1W
4/13

The sarcomeres seemed to be connected to focal adhesions on the bottom of the cell by thin actin bundles that resembled the dorsal stress fibers (DSF) commonly found in non-muscle cells. This movie steps through a Z stack of a myocyte starting at the bottom of the cell.
5/13

You May Also Like
Recently, the @CNIL issued a decision regarding the GDPR compliance of an unknown French adtech company named "Vectaury". It may seem like small fry, but the decision has potential wide-ranging impacts for Google, the IAB framework, and today's adtech. It's thread time! 👇
It's all in French, but if you're up for it you can read:
• Their blog post (lacks the most interesting details): https://t.co/PHkDcOT1hy
• Their high-level legal decision: https://t.co/hwpiEvjodt
• The full notification: https://t.co/QQB7rfynha
I've read it so you needn't!
Vectaury was collecting geolocation data in order to create profiles (eg. people who often go to this or that type of shop) so as to power ad targeting. They operate through embedded SDKs and ad bidding, making them invisible to users.
The @CNIL notes that profiling based off of geolocation presents particular risks since it reveals people's movements and habits. As risky, the processing requires consent — this will be the heart of their assessment.
Interesting point: they justify the decision in part because of how many people COULD be targeted in this way (rather than how many have — though they note that too). Because it's on a phone, and many have phones, it is considered large-scale processing no matter what.
It's all in French, but if you're up for it you can read:
• Their blog post (lacks the most interesting details): https://t.co/PHkDcOT1hy
• Their high-level legal decision: https://t.co/hwpiEvjodt
• The full notification: https://t.co/QQB7rfynha
I've read it so you needn't!
Vectaury was collecting geolocation data in order to create profiles (eg. people who often go to this or that type of shop) so as to power ad targeting. They operate through embedded SDKs and ad bidding, making them invisible to users.
The @CNIL notes that profiling based off of geolocation presents particular risks since it reveals people's movements and habits. As risky, the processing requires consent — this will be the heart of their assessment.
Interesting point: they justify the decision in part because of how many people COULD be targeted in this way (rather than how many have — though they note that too). Because it's on a phone, and many have phones, it is considered large-scale processing no matter what.
And here they are...
THE WINNERS OF THE 24 HOUR STARTUP CHALLENGE
Remember, this money is just fun. If you launched a product (or even attempted a launch) - you did something worth MUCH more than $1,000.
#24hrstartup
The winners 👇
#10
Lattes For Change - Skip a latte and save a life.
https://t.co/M75RAirZzs
@frantzfries built a platform where you can see how skipping your morning latte could do for the world.
A great product for a great cause.
Congrats Chris on winning $250!
#9
Instaland - Create amazing landing pages for your followers.
https://t.co/5KkveJTAsy
A team project! @bpmct and @BaileyPumfleet built a tool for social media influencers to create simple "swipe up" landing pages for followers.
Really impressive for 24 hours. Congrats!
#8
SayHenlo - Chat without distractions
https://t.co/og0B7gmkW6
Built by @DaltonEdwards, it's a platform for combatting conversation overload. This product was also coded exclusively from an iPad 😲
Dalton is a beast. I'm so excited he placed in the top 10.
#7
CoderStory - Learn to code from developers across the globe!
https://t.co/86Ay6nF4AY
Built by @jesswallaceuk, the project is focused on highlighting the experience of developers and people learning to code.
I wish this existed when I learned to code! Congrats on $250!!
THE WINNERS OF THE 24 HOUR STARTUP CHALLENGE
Remember, this money is just fun. If you launched a product (or even attempted a launch) - you did something worth MUCH more than $1,000.
#24hrstartup
The winners 👇
#10
Lattes For Change - Skip a latte and save a life.
https://t.co/M75RAirZzs
@frantzfries built a platform where you can see how skipping your morning latte could do for the world.
A great product for a great cause.
Congrats Chris on winning $250!

#9
Instaland - Create amazing landing pages for your followers.
https://t.co/5KkveJTAsy
A team project! @bpmct and @BaileyPumfleet built a tool for social media influencers to create simple "swipe up" landing pages for followers.
Really impressive for 24 hours. Congrats!

#8
SayHenlo - Chat without distractions
https://t.co/og0B7gmkW6
Built by @DaltonEdwards, it's a platform for combatting conversation overload. This product was also coded exclusively from an iPad 😲
Dalton is a beast. I'm so excited he placed in the top 10.

#7
CoderStory - Learn to code from developers across the globe!
https://t.co/86Ay6nF4AY
Built by @jesswallaceuk, the project is focused on highlighting the experience of developers and people learning to code.
I wish this existed when I learned to code! Congrats on $250!!
