Every node is a synapse in webs of ideas.
This outstanding medical website about radiology is a learn node unto itself. There are articles richly illustrated with radiological images — X-rays — organized by anatomy. Major groups are abdomen, cardiovascular, chest, mammography, musculoskeletal, pediatrics, and neuroradiology. The Top Sites page connects to many more articles and websites, forming a cluster of nodes about radiological imaging.
via: Scout Report
To begin to learn how hearing and balance work a good introduction is an online overview from the American Speech-Language-Hearing Association. The overview begins:
Hearing is one of the five senses. It is a complex process of picking up sound and attaching meaning to it. The human ear is fully developed at birth and responds to sounds that are very faint as well as sounds that are very loud. Even in utero, infants respond to sound. The ability to hear is critical to the attachment of meaning to the world around us.
The ASHA webpage then explains the functions of the five sections of the hearing mechanism: 1. Outer ear, 2. Middle ear, 3. Inner ear, 4. Acoustic nerve, and 5. Brain’ s auditory processing centers.
Much more about hearing can be learned in the Open University’s Science and Nature materials about Hearing. The illustration with this learn node is from those Open University materials in the section about neural processing of auditory information. To get into even more minute details, the Proceedings of the National Academy of Sciences of the United States have an in-depth article on how visual speech speeds up the neural processing of auditory speech. Together these resources, and the links they in turn provide, are a starting learn node for many related hearing subjects.
In this learn node illustration you are seeing structure inside a Monarch butterfly brain. It is from a research article in PLOS Biology on what may underlie sun compass navigation, shown on this page in Figure S10. CRY2 RNA Distribution in Monarch Brain. If the circadian clock mechanism of butterfly brains seems too detailed for what you want to learn or teach now, you could find less specialized material in the latest news on Monarch Butterfly migration and Journey North. Each of these butterfly sources provides links to other good materials about these beautiful insects. So does this Wikipedia Monarch butterfly article, which includes a reference to the video below of a Monarch butterfly emerging from its chrysalis. Within the brain of the emergent baby butterfly is the RNA that science is learning will inform his flight north, guided by the sun. All of these materials are open, free, richly connected nodes in the global learning commons.
The image in this learn node of mouse neurons of many colors is from a Harvard Science video called Somewhere, inside the Brainbow which you can view by clicking its title in this sentence. The accompanying HARVARDSCIENCE article here overviews the project, which is led by Harvard’s Jean Livet, Joshua R. Sanes, and Jeff W. Lichtman. The article explains:
By activating multiple fluorescent proteins in neurons, neuroscientists at Harvard University are imaging the brain and nervous system as never before, rendering their cells in a riotous spray of colors dubbed a “Brainbow.” . . .
“There are few tools neuroscientists can use to tease out the wiring diagram of the nervous system; Brainbow should help us much better map out the brain and nervous system’s complex tangle of neurons,” Lichtman said.
Equal parts pointillism, fauvism, and abstract expressionism, the resulting images could also help scientists identify how brain wiring goes awry in many different diseases. Brainbow could also help track the complicated development of the mammalian nervous system, currently understood only in general terms. This, in turn, could elucidate the origins of the many brain disorders that arise early in development.
Drawing upon a mix of genetic tricks and special proteins that cause cells to glow, Brainbow uses a well-known genetic recombination system known as Cre/lox in a new way, to shuffle genes encoding green, yellow, orange, and red fluorescent proteins. The researchers painstakingly assembled the Brainbow transgene from snippets of DNA, and inserted it into neuronal DNA. As they predicted, the cut-and-paste recombination occurred totally at random, in the process assigning scores of different colors to neurons. This variation makes neurons leap out from one another visually under ordinary confocal microscopy.
Photonics.com picked up on the Brainbow story from the scientific imaging perspective, with an article called ‘Neurons Glow in ‘Brainbow’: “Brainbow allows researchers to tag neurons with roughly 90 distinct colors, a huge leap over the mere handful of shades possible with current fluorescent labeling. By permitting visual resolution of individual brightly colored neurons, this increase should greatly help scientists in charting the circuitry of the brain and nervous system.”
Chemistry World calls its report on this research Brain’s wiring seen in Technicolor, and includes nine still images of different Brainbow perspectives.
If you visit the the Brainbow links above, and others such as a report today in the New York Science Times, you will note that they all mention that Brainbow is the cover story of this week’s Nature magazine. The report in Nature magazine is not, however, a learnode (a node for learning in the open Internet) because it is not open. All of the other sources mentioned, and the supplementary links that they offer are open. What makes Nature not open is more than the fact that it is closed except to paid subscribers and purchasers of its Brainbow article. The Nature article is also not open because it cannot be a node in a network cluster of Brainbow links. Only open links can be learnodes in subject clusters where the links enrich each other and keep each other up-to-date. By analogy to the neuron image above: the open articles interconnect like the different colored neurons do; the Nature article is an isolated dot with no extending dendrite.
GOTO more biology learn node clusters.
More learn nodes at: learnodes.com
As 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?
More learn nodes at: learnodes.com
Visit GoldenSwamp.com for discussions of the way learning is emerging in the 21st century.
