Recent comments in /f/askscience

Coffeinated t1_j3rlegu wrote

If I remember correctly, the reduction in peak BAC stems from the fact that the absorption if alcohol is heavily delayed or rather slowed down, thus flattening the curve. Compare drinking a bottle of wodka on the spot to drinking beer with the same alcohol content (roundabout 5.5 liters of beer) over the course of a whole evening.

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Captain_Poodr t1_j3rl36n wrote

Drain the water away and allow the ice to be in contact with air. Raising the temperature of water requires many times more input energy than raising the temperature of air. Also, air will flow over the exposed surface area of the block at a larger temperature differential than the melted water. This will encourage faster melting. When ice is melting in a glass of water, the temperature of the water itself remains close to 32F until the ice has melted. All of the energy being absorbed into the water from the environment is essentially going straight to phase changing the ice back to a liquid, but as mentioned above it requires far more energy to raise the temperature of water than air

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Archy99 t1_j3r13t9 wrote

Can neutrophils decide to be autoimmune?

No, because they don't have adaptive receptors targeted towards self antigens.

It is important not to confuse autoinflammitory with autoimmunity. Autoimmunity is based on either T-cells or B-cells (or plasma cells which are derived from B-cells) having their characteristic adaptive receptor (B cell receptor or T cell receptor) strongly bind to specific self antigens.

Note that T-cell autoimmune diseases are still hypothetical.

(More specifically, no one has characterised the T-cell receptor repertoire and demonstrated close to 100% sensitivity or specificity for a T-cell receptor subset for any disease - anyone claiming I am wrong is going to have trouble citing proof). T-cells undergo a strong selection process in the thymus to prevent autoimmunity, whereas no such process occurs for B-cells. B-cell autoimmunity doesn't necessarily need T-cell autoimmunity either.

Whereas all currently well-characterised autoimmune diseases are either B-cell diseases (associated with autoantibodies) or are in fact autoinflammatory, rather than autoimmune diseases. For example the Arthropathies do involve self-reactive T-cells but this self reactivity isn't primary driven due to self-reactive T-cell receptors, but rather they are causing inflammation regardless of what the T-cell receptor codes for.

There are parenoplastic diseases (T-cell cancers) that can rarely be autoreactive but these are extremely rare and the primary disease is the cancer.

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