What are the main causes of hypotension?

Shock is is defined as hypotension + end organ damage, such as in the kidney, heart, liver, GI tract, or brain, and there are three big buckets of kinds of shock -- cardiogenic, distributive, and hypovolemic. Cardiogenic shock is a result of decreased cardiac function, resulting from a number of conditions such as acute myocardial infarction (heart attack) or heart failure. Distributive shock means that fluid is "pooling" elsewhere in the body and not returning to the heart, causing decreased preload and reduced cardiac output; the most common cause of distributive shock is sepsis, which dilates blood vessels throughout the body. Hypovolemic shock, which people commonly cause dehydration, means there just isn't enough blood volume, either because someone has not been taking enough fluids in or has lost a lot of blood due to trauma or internal injury.

What is "statistically significance" all about?

Basic statistics is all about accounting for randomness and chance. We don't want to have to survey *every* person in a country to know whether men and women have different salaries - that would be way too expensive and take too long! Instead, we want to be able to *sample* a small number of people and *infer* what our data tells us about the whole population. So, when we report whether a piece of information is *statistically significant,* that's code for, "I am reasonably confident this is true, even though I didn't ask everyone." In the example mentioned, we would say, "our data shows that women in the US earn less than men, and our result is significant at the 5% level." That means that, even though we didn't ask EVERYONE in the country how much they earn, we're pretty confident (given the information from people we *did* ask) that the average woman's salary is less than the average man's. More precisely, it means that there's only a 5% chance of us getting our results if there weren't, in fact, a difference in salaries between men and women.

What effect did World War II have on the political environment of sub-Saharan Africa?

WWII influenced economic growth, independence movements, and political boundaries of sub-Saharan Africa. --The post-war boom increased demand for raw materials, and newly secure sea routes decreased the cost of trade, contributing to economic growth throughout the region. --Decolonization movements were energized by the return of young men who had fought for British and French forces in the war. They put their lives on the line for colonial powers and received more education and training than had previously been available, but there were limited employment opportunities for them when they returned home and they were granted few (if any) political rights. Their discontentment and rising political consciousness fueled independence movements. --After Germany's defeat, control over several colonies was transferred to the victors of WWII, which would have long-term consequences for political development (particularly in places like Namibia, DRC, and Rwanda).