22

You're talking about long-wave UV, or UV-A radiation. In the 80s, experts claimed that this was a safe wavelength. Protection against UV-A was not part of sunscreen in the early days. Consequently, UV-A was (and still is) used in tanning beds due to its perceived safety over UV-B. However, a lot of research has been done since. UV-A is well understood now ...


8

Tarrare Tarrare was a showman who was renowned for his insatiable appetite including eating cats, dogs, and snakes sometimes raw. He is also said to have eaten many inedible items. At the time, he was alleged to have committed cannibalism of a 14-month-old baby and was caught in the act of cannibalising cadavers by hospital staff. He was given away as a ...


5

The histogram you show isn't a distribution of age-at-death for individuals, it's a distribution of life expectancies for different countries. The post you link takes data from a table on this page. Interpreting the histogram you posted, we see average life expectancy seems to hit a wall around 85. This does not mean that individual human life span is not ...


4

There are (at least) two sides to this story. One is direct DNA damage being caused by UV-B light which happens to have photons with just the right amount of energy to interact with thymine. This has been known, and assumed not just during the 80s, but until the late 2000s to be The One major thing that causes cancer, or trouble in general (there's papers ...


4

Stress response has 2 main components: Quick response, within minutes, is by the Sympathomedullary Pathway (SAM): hypothalamus > sympathetic nervous system > release of adrenaline and noradrenaline from the adrenal medulla > stimulation of the heart, dilation of the muscle arteries, constriction of the gut and skin arteries, glcogenolysis (the breakdown of ...


3

Tarrare had these symptoms: Grossly increased appetite, eating raw meat and other inedible things Excessive sweating with bad body odor Chronic diarrhea, which was "fetid beyond all conception" Wide jaw, abnormally large esophagus and stomach Loose skin around his cheeks and stomach Heavily stained teeth Unusually soft fair hair Apathetic temperament He ...


2

There's no particular reason everything in nature needs to fit a normal distribution; normal distributions are just one of many different types of naturally-occurring distributions. In some cases, the other types can be transformed (e.g. by logarithms) into a normal distribution (e.g. a log-normal distribution), in other cases not so much. As to why it ...


2

There is no genetic basis for these classifications. Most human genetic diversity is in Africa. Diversity only decreases with geographic distance from this continent. There are geographic clines, not the clusters that one might call race. Here are some results from Rosenberg's 2002 Genetic Structure of Human Populations: 93-95% of variation occurs within ...


1

The ratio you are referring to is indeed computed aggregating multiple observations and thus it is a "statistical average". Any individual (or couple, in this case) can have a specific ratio that differs from the average one. Many factors may affect sex ratio, among which sperm/egg viability, chromosomal aberrations, and hormones misbalance are the ones ...


1

You're right that both polygeny and polymorphism contribute to the diversity of a given gene in the population correctly described what they mean individually. However, you missed that the polygeny of MHC means that the human genome has 3 different loci/genes (called MHC-I A,B & C) in the haploid genome, meaning that any given human as actually 6 ...


1

LARGE MEALS AND ABSORPTION When consumed in usual amounts, the percent of absorbed macronutrients (carbohydrates, proteins, fats, alcohol) should not differ significantly when coming from one large or several small meals. As an example of the composition of a single large meal, let's imagine something that fits into Acceptable Macronutrient Distribution ...


1

In short: skipping a meal lowers blood glucose levels, which can reduce cognitive performance, for example, memory. Let's say that between meals you are in fasting state for 8 hours during which you do some desk work and some moderate exercise for 1.5 hours. With such level of physical activity, your last meal and your glycogen stores should provide enough ...


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