Schizophrenia is more common in individuals born in the wintertime. This lead scientists to suspect that it was caused by a virus. A person's immune system is not as strong in cold weather, and therefore a winter newborn is more susceptible to infections.

The hypothesis of a viral cause of schizophrenia seemed to be bolstered by findings that the strongest genetic markers that predict schizophrenia code for proteins in the immune system.

But as scientists investigated further, the immune systems role in schizophrenia seems to have nothing to do with infections, viral or otherwise. 

It appears that the immune system plays a non-immunological role in the brain. Specifically, the immune system appears to mediate the process of synaptic pruning. Synaptic pruning is where unneeded connections between neurons are removed. Such an unneeded connection is "labeled" for elimination in a manner similar to how a infectious bacterium is "labeled" for elimination.

Dysfunction in this part of the immune system could therefore cause the process go haywire and end up pruning far too many neural connections, as is seen happening in a part of the brain called the "pre-frontal cortex" of schizophrenia patients.

My oven seemed to have developed a penchant for burning food.

I thought perhaps the the temperature of the oven is higher than what is indicated on the dial. I tried reducing the cooking temperature by 25 degrees (so cook at 375, if the box says cook at 400). But the the food still burned.

So I bought an oven thermometer to figure out what the temperature actually was. I made several measurements at different set temperatures to get an idea what the general relationship was between the the set temperature on the dial and what the actual temperature of the oven (as measured by the oven thermometer). In each case, I waited at least ten minutes for the oven to reach the set temperature before making a reading.

What I found out was quite surprising. There is a marked difference between the set and actual temperature. Interestingly the discrepancy widens at lower set temperatures. Indeed the lowest measurement is at a set temperature of 200 degrees, but the actual temperature of the oven was about 330 degrees. This is a 130 degree difference! Wow! I am glad I know this now.