scienceyoucanlove

scienceyoucanlove:

Bloodletting

Phlebotomy, or bloodletting, is the longest-running tradition in medicine. It originated in the ancient civilizations of Egypt and Greece, persisted through the Medieval, Renaissance, and Enlightenment periods, flourished in Arabic and Indian medicine, and lasted through the second Industrial Revolution. The practice continued for 2,500 years until it was replaced by the techniques of modern medicine. 


Doctors bled patients for every ailment imaginable. They bled for pneumonia and fevers, back pain and rheumatism, headaches and melancholia; even to treat bone fractures and other wounds. Yet there never was any evidence that phlebotomy did any good.

Bloodletting was based on an ancient system of medicine in which blood and other bodily fluid were considered to be “humors” whose proper balance maintained health. Sick patients were thought to have an imbalance of their humors, which bloodletting was thought to restore. 

Most bloodletters would open a vein in the arm, leg or neck with small, fine knife called a lancet. They would tie off the area with a tourniquet and, holding the lancet delicately between thumb and forefinger, strike diagonally or lengthwise into the vein. (A perpendicular cut might sever the blood vessel.) They would collect the blood in measuring bowls, exquisitely wrought of fine Venetian glass.

Bleeding was as trusted and popular in ancient days as aspirin is today. The Talmudic authors laid out complex laws for bloodletting. Medieval monks bled each other several times a year for general maintenance of health. Doctors devised elaborate charts indicating the most favorable astrological conditions for bleeding.

It wasn’t until well into the 19th century that people began to question the value of bloodletting. Scientists such as Louis Pasteur, Joseph Lister, and Robert Koch showed that germs, not humors, were responsible for disease. Furthermore, medical statisticians tracking case histories began to collect evidence that bloodletting was not effective. Eventually the practice died, although it continued in some parts of rural America into the 1920s.

Phlebotomy is almost never used anymore, except for certain rare conditions. One is hemachromatosis, a genetic condition affecting 600,000 to 1,000,000 Americans in which the body stores too much iron. One way to treat this is to periodically drain some of their iron-rich blood, which restores the mineral’s proper balance.

-Douglas Starr

text source 

photos from wiki article

read about the history of blood letting here 

scienceyoucanlove
sinobug:

Female Iceryine Scale Insect (Icerya sp., Monophlebidae, Coccoidea, Hemiptera)  I have immense difficulties coming to terms with these extraordinary insects and admit to barely understanding their biology, taxonomy or physiology.  The fringe of “fingers” (no they are not legs) are secreted by special glands on the body of the female. In this case some of those “fingers” (normally or abnormally) have been initiated in a spiral motif. Males have one pair of wings and look completely different.   by Sinobug (itchydogimages) on Flickr. Pu’er, Yunnan, China  See more Chinese insects and spiders on my Flickr site HERE……

sinobug:

Female Iceryine Scale Insect (Icerya sp., Monophlebidae, Coccoidea, Hemiptera)

I have immense difficulties coming to terms with these extraordinary insects and admit to barely understanding their biology, taxonomy or physiology.

The fringe of “fingers” (no they are not legs) are secreted by special glands on the body of the female. In this case some of those “fingers” (normally or abnormally) have been initiated in a spiral motif. Males have one pair of wings and look completely different.

Iceryine Scale Insect (Icerya sp., Monophlebidae, Coccoidea)

by Sinobug (itchydogimages) on Flickr.
Pu’er, Yunnan, China

See more Chinese insects and spiders on my Flickr site HERE……

techstuffhsw
neurosciencestuff:

Why Do Our Brains Sometime Mess Up Simple Calculations?

If the human brain is comparable to a computer, why does it so often make mistakes that its electronic counterpart does not? New research suggests it all has to do with how various problems are presented.
Scientists typically like to make this comparison because both the human brain and a computer typically follow a set of rules in which to make decisions, communicate and perform other tasks. However, University of Wisconsin-Madison cognitive scientist and psychology professor Gary Lupyan said people can get tripped up on even the simplest logic problems because they get caught up in contextual information.
For example, even a simple challenge like determining whether or not a number is odd or even can be tricky, under the right circumstances. Lupyan said that there is a significant minority of people, even if they are well-educated, that can mistake a number such as 798 for an odd number – because, even though deep down we know that only the last number is used to determine whether it is even or odd, we can be fooled by the presence of two odd numbers.
“Most of us would attribute an error like that to carelessness, or not paying attention, but some errors may appear more often because our brains are not as well equipped to solve purely rule-based problems,” the professor, whose work appears in a recent edition of the journal Cognition, explained in a statement Friday.
In multiple trials involving such tasks as sorting numbers, shapes and even people into easy categories like evens, triangles and grandmothers, Lupyan found study participants often broke simple rules based on context.
For instance, when asked to consider a contest that was only open to grandmothers and that each eligible individual had an equal chance of winning, the subjects believed a 68-year-old woman with six grandchildren was more likely to emerge victorious than a 39-year-old female with one single, newborn grandchild.
“Even though people can articulate the rules, they can’t help but be influenced by perceptual details,” he explained. “Thinking of triangles tends to involve thinking of typical, equilateral sorts of triangles. It is difficult to focus on just the rules that make a shape a triangle, regardless of what it looks like exactly.”
Lupyan said that in many cases, not only is overlooking these types of rules overly detrimental, but doing so can actually be beneficial when it comes to evaluating unfamiliar things. The lone exception, he said, is when it comes to mathematics, where rules are unequivocally necessary in order to achieve a successful outcome.
“After all, although some people may mistakenly think that 798 is an odd number, not only can people follow such rules – though not always perfectly – we are capable of building computers that can execute such rules perfectly,” Lupyan said. “That itself required very precise, mathematical cognition. A big question is where this ability comes from and why some people are better at formal rules than other people.”
He added this issue could be especially important to math and science teachers: “Students approach learning with biases shaped both by evolution and day-to-day experience. Rather than treating errors as reflecting lack of knowledge or as inattention, trying to understand their source may lead to new ways of teaching rule-based systems while making use of the flexibility and creative problem solving at which humans excel.”

neurosciencestuff:

Why Do Our Brains Sometime Mess Up Simple Calculations?

If the human brain is comparable to a computer, why does it so often make mistakes that its electronic counterpart does not? New research suggests it all has to do with how various problems are presented.

Scientists typically like to make this comparison because both the human brain and a computer typically follow a set of rules in which to make decisions, communicate and perform other tasks. However, University of Wisconsin-Madison cognitive scientist and psychology professor Gary Lupyan said people can get tripped up on even the simplest logic problems because they get caught up in contextual information.

For example, even a simple challenge like determining whether or not a number is odd or even can be tricky, under the right circumstances. Lupyan said that there is a significant minority of people, even if they are well-educated, that can mistake a number such as 798 for an odd number – because, even though deep down we know that only the last number is used to determine whether it is even or odd, we can be fooled by the presence of two odd numbers.

“Most of us would attribute an error like that to carelessness, or not paying attention, but some errors may appear more often because our brains are not as well equipped to solve purely rule-based problems,” the professor, whose work appears in a recent edition of the journal Cognition, explained in a statement Friday.

In multiple trials involving such tasks as sorting numbers, shapes and even people into easy categories like evens, triangles and grandmothers, Lupyan found study participants often broke simple rules based on context.

For instance, when asked to consider a contest that was only open to grandmothers and that each eligible individual had an equal chance of winning, the subjects believed a 68-year-old woman with six grandchildren was more likely to emerge victorious than a 39-year-old female with one single, newborn grandchild.

“Even though people can articulate the rules, they can’t help but be influenced by perceptual details,” he explained. “Thinking of triangles tends to involve thinking of typical, equilateral sorts of triangles. It is difficult to focus on just the rules that make a shape a triangle, regardless of what it looks like exactly.”

Lupyan said that in many cases, not only is overlooking these types of rules overly detrimental, but doing so can actually be beneficial when it comes to evaluating unfamiliar things. The lone exception, he said, is when it comes to mathematics, where rules are unequivocally necessary in order to achieve a successful outcome.

“After all, although some people may mistakenly think that 798 is an odd number, not only can people follow such rules – though not always perfectly – we are capable of building computers that can execute such rules perfectly,” Lupyan said. “That itself required very precise, mathematical cognition. A big question is where this ability comes from and why some people are better at formal rules than other people.”

He added this issue could be especially important to math and science teachers: “Students approach learning with biases shaped both by evolution and day-to-day experience. Rather than treating errors as reflecting lack of knowledge or as inattention, trying to understand their source may lead to new ways of teaching rule-based systems while making use of the flexibility and creative problem solving at which humans excel.”