Learn Node: Helmets to prevent brain injury 79 AD and 2007 AD

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Posted on 27th October 2007 by Judy Breck in design | engineering | health

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football helmet gladiator helmetAs this learn node shows, the recent publicity and concern for concussion injuries in sports provides a demonstration of the way networking online knowledge can produce comparative studies from distant fields. When it comes to helmets, history, sports and brain science form a focused network of ideas from all three fields.

Earlier this month, the National Athletic Trainers Association issued a press release describing their new campaign for sports concussion education. The release explains:

The Centers for Disease Control estimate that 300,000 brain injuries occur in sports each year. Of these reported concussions, an estimated 63,000 occur among high school athletes. Even though these numbers alone suggest that concussions represent a significant public health concern, it is likely that many athletes with concussions fail to report their symptoms to medical personnel.

The New York Times today is carrying the story of a new football helmet being developed by former Harvard quarterback Vin Ferrara. The football helmet in the image above is from an interactive graphic that can now be used freely online because of the NY Times new open content policy.

There is, of course, nothing new about the need to protect the human head from blows. Helmet designers have been scratching their heads for centuries to come up with a better way to prevent battering brains by external blows.

The image of the Roman helmet in the graphic above is a Helmet of a Thracian Gladiator on exhibit at the Louve Museum in Paris, France and on their museum website. In this caption the Louvre curators describe the helmet�where there is, like modern sports helmets, distinctive decoration as well as protective features:

Several examples of highly enveloping helmets of this type have been found at Pompeii. They were part of the equipment used by the most heavily armed gladiators – those from the northeast of Greece, the “Thraces” (Thracians), and those from Gaul, the “mirmillones”. The shell of the helmet is highly rounded, with a broad brim, and has a crest decorated with overlapping plumes and terminating in a griffin’s head. This mythological creature was the companion of Nemesis, the goddess of fate, who was venerated by gladiators (there was often a chapel dedicated to her inside the amphitheater). On the front of the helmet, the silver-plated head of the Gorgon Medusa stands out. On either side of the helmet are plume holders to which feathers were attached. The face and neck of the gladiator were protected by a movable visor made up of four riveted plates, two of them solid, the other two pierced.

One of the marvelous resources for open education are museums. Because textbooks must be brief and general, the helmet of a Thracian Gladiator would not survive the first round of editing battles.

Head injury in the past was invisible. A Thracian helmet designer or doctor would have been unable to look inside the skull to see the brain injury of a gladiator whose head had been struck in battle. But today, we can examine brain injuries inside the brain with methods like Computed Tomography (CT) of the head, which is also to be found among open knowledge resources online.

To venture into the future, how about a look at cloning brains in 3D animation of androids at Tufts University?

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Learn node: Muscle motor units and neurons from the bottom up

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Posted on 19th October 2007 by Judy Breck in biology | design | sciences

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motor neuron muscle

The image for this learn node is from Dr. Emad Eskandar’s Harvard-MIT Health Sciences and Technology Neuroscience course handout (Motor Systems I). Page 2, With the image the handout explains:

We will begin our discussion from the bottom up starting with the physiology of the muscles and the spinal cord. An important concept to grasp is that of the motor unit. The following points should be kept in mind.
- A whole muscle is made up of many muscle fibers
- A muscle fiber is a single mutlinucleated cell
- Each muscle fiber is innervated by only one alpha motor neuron
- Each alpha motor neuron innervates numerous muscle fibers within a muscle
- A single neuron and all the muscle fibers it innervates are a motor unit
- The motor unit is the smallest division that the system can control individually

You can connect the muscle concepts above to another superb academic source by going to the Tufts Dental School course: Histology: Study of Cells, Tissues and Organs. Lecture 9: Muscle, on page 5 of the PDF summarizes the sequence of events of a muscle contraction. This Tufts muscle lecture can flex the most curious young mind � one that wants move past the medium learning fare.

To drop by and look over the shoulders of some scientists learning about muscle motor neurons from the transparent spinal cord of the zebrafish, click into The Journal of Neuroscience, where the articles are freely open online for the benefit of scientists, students and teachers.

For a look at the same information in non-academic, non-medical terms: How Muscles Work at HowStuffWorks.com.

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Learn node: Mechanics of stone structures

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Posted on 13th September 2007 by Judy Breck in design | engineering | math | mechanics

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arch structure

This learn node features a video called “The Arch Never Sleeps” in which professors explain the mechanics of the support arches provide for structures. One professor points out the limitations of laying a block of stone across two others. The professor whose foot is shown as he stands on an arch (that is not glued together) is demonstrating the strength of stone arches. The video is on a page from the Open University Mathematics and Statistics modeling problems open courseware.

If the concepts of arches and mechanical forces get curiosity strongly aroused, a popular online set of notes for the mathematics of mechanics can be found at the University of Nebraska-Lincoln. Included are algebra, geometry, trigonometry, analytical geometry, calculus and vectors � as each of them relates to mechanics. Or for more concrete contemplations of arches mathematics and more, there is a page titled Geometry of Bridge Construction by a Jesuit teacher of math. That site includes a quick explanation of the famed seven Bridges of Konigsberg problem and Euler’s solution that provides a key basis for understanding how the connectivity of the Internet makes it possible for learn nodes to form the webs from which ideas can emerge. Related in time and math concepts are the Medieval breakthroughs in math visible in mosaics from Islamic buildings.

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