Stem cells have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new cell has the potential to either remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.

Harvard Science describes how bone marrow stem cells may help control inflammatory bowel disease in “the first demonstration of their ability to suppress a broad-based autoimmune reaction and protect gastrointestinal tissue.” Science News headlines: Bone Marrow Alternative: Stem Cells From Umbilical Cord May Be Used To Treat Hepatic Diseases, in an article pointing to stories about several other uses for bone marrow stem cells.

The Learn.Genetics project at the University of Utah offers a section on Stem Cell Therapies Today with illustrated explanations and links to related tropics. The National Cancer Institute provides detailed discussions of Bone Marrow Transplantation and Peripheral Blood Stem Cell Transplantation.

This learn node about the discovery of 150,000 western lowland gorillas is prompted by a New York Times Science Times report. The image with this post is from a slide show accompanying the Science Times article. The discovery was announced by the Wildlife Conservation Society. The Society’s information section on the Western Lowland Gorilla does not yet have the good news of the new discovery as this learn node is written. By the time you are reading this it probably will because online resources are usually the first science to be updated. Although the new discovery makes some of the gorilla numbers happily out of date in this Gorilla Rescue video, the presentation is an excellent introduction for young humans to the challenge that lies ahead in their lifetime for caring for their fellow creatures of our planet.

From the Metropolitan Museum of Art’s podcast program, this learn node begins with a link to an RSS distributed podcast of a classic fable recorded for a family audience. The story on the podcast is The Lion and the Mouse, which can also be found in the Aesop’s Fables collection at the University of Massachusetts Amherst. The Amherst collection has been built by students since 1994 and now includes some of the famed fables told with animations and interactivity. The Prelinger Archives offers a 1947 state-of-the-then art version (a frame captured above) of Aesop’s fable of The Hare and the Tortoise.

Using the network node is the first key to the effectiveness in creating superior knowledge content in the open Internet. The second key is the creation of the nodes by people who are experts in their subject. The About page of APOD explains:

Astronomy Picture of the Day (APOD) is originated, written, coordinated, and edited since 1995 by Robert Nemiroff and Jerry Bonnell. The APOD archive contains the largest collection of annotated astronomical images on the internet.

In real life, Bob and Jerry are two professional astronomers who spend most of their time researching the universe. Bob is a professor at Michigan Technological University in Houghton, Michigan, USA, while Jerry is a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland USA.

The illustration for this learn node is from a Tufts University on “Emerging Infections and Agents of Biological Warfare.” The West Nile Virus transmission cycle is also illustrated in a chart at the Centers for Disease Control and Prevention (CDC). An interesting angle on the transmission is that protecting biodiversity of birds slows it down, as described in a Public Library of Science article:

We found there is lower incidence of human WNV in eastern US counties that have greater avian (viral host) diversity. This pattern exists when examining diversity-disease relationships both before WNV reached the US (in 1998) and once the epidemic was underway (in 2002). The robust disease-diversity relationships confirm that the dilution effect can be observed in another emerging infectious disease and illustrate an important ecosystem service provided by biodiversity, further supporting the growing view that protecting biodiversity should be considered in public health and safety plans.

This learn node points you to definitions by the Whole Grain Council, Mayo Clinic explanations of natural whole grain nutrition, and Johns Hopkins School of Public Health lectures on Popular Diets and Dietary Supplements. For learning the role of whole grains in healthy, nutrition, and anti-aging, these three excellent, authoritative sources bring together nutrition facts for natural whole grain and studies of nutrition supplements.

The image with this post is Bob’s Red Mill’s drawing of the basic whole grain anatomy: bran, endosperm, and germ, plus a slide from Lecture 6 of the Johns Hopkins Bloomberg School of Public Health course on Critical Analysis of Popular Diets and Dietary Supplements.

This image includes a synapse drawing from the Sanger Institute. I have inverted the colors in the drawing because they are striking, and have added a learn node drawing for comparison. The Sanger team studying “Genes to Cognition” observes on the page where the drawing is placed:

The synapse the junction between nerve cells is the most important component of the nervous system. It not only transmits electrical information between neurons, but also is responsible for converting the electrical signals into biochemical changes of long term memory.

Without being “spooky” about assuming what is true for the brain is true for the Net - it is fair to say that it is worth a careful look to see what can be done with Net nodes to improved the quality of learning online. In this blog, I will continue to attempt to create learn nodes that apply network laws, search engine optimization techniques, and a few things we learn from synapses. Educators and experts who use what they know about a subject to create and strengthen Net nodes are doing something very important.

More in early July, when I return from talking about this subject at Microlearning2008.

Looking at the little tiny world - at things like bilayer formation of cells, veins, and neurons in biological membranes - is becoming more an more sophisticated and productive. The image with this post from page 7of Lecture 6: AFM imaging II: Artifacts and Applications from the MIT lecture notes for a course on Nanomechanics of Materials and Biomaterials. The image originates in the LadyofHats collection of public domain images, which is a source of superb drawings of dinosaurs, biology, and other subjects.

A general article describing micro and nanomechanics is available on the IMES Institute of Mechanical Systems website. This is its introductory overview:

Micro- and nanomechanics are concerned with the modelling, design, fabrication and application of three-dimensional structures and systems with dimensions in the range of micrometers and below. These systems incorporate a number of interesting features: The classical fabrication methods of micromachining are extended by those developed in the semiconductor industry during the passed decades. Different quantities scale differently when moving from large to small structures demanding new models to describe the physical behaviour observed on a small scale.Devices used to perform a certain function and found to be optimal for the macroscopic scale are replaced by others exploiting various physical effects suited to the microscopic world.

Last but not least, the limits of classical continuum mechanics have to be explored and extended. New methods need to be developed in order to quantify bonding properties between different layers, residual stresses which are caused by manufacturing processes as well as the elastic constants itself, just to mention a few examples.

The New York Times report on the biodiversity topic “Forest Disappearing in Papua New Guinea” is a learn node connecting to interrelated topics of significance and urgency. The full rain forest report can be downloaded from the PGN Remote Sensing Center whose homepage is shown in the image with this post. For background on the Papua New Guinea location of this specific biodiversity challenge, the New York Times has a detailed PNG country section. Enriching this learn node from the sciences side are Connexions learning objects on the definition of biodiversity and an introduction to biodiversity.

Phoenix Mars Lander is the topic of a magnificent learn node in the New York Science times today. Like any quality learn node, this one in the Times focuses on a small hunk of a subject: the scheduled landing of the vehicle this week on Mars. The node has internal links to superb supporting materials such as the graphic from which a piece is shown at the top of this post - although the graphic regretfully does not have a url of its own. Other internal links do, such as the slide show.

The node aspects are stunted here because there are not links beyond the NY Times to related material, such as The University of Arizona’’s Phoenix Mars Mission home webpage and NASA’s Phoenix Mars Lander homepage. The great news is that the New York Times no longer posts its science materials for free and then a few days later closes them behind a paid subscription. Since it will remain open online, this Phoenix Mars Lander node will remain available to link into other networks of space exploration and related subjects.