Learn node: dinosaur teeth and the reptile mouth


Posted on 18th November 2008 by Judy Breck in biology | general science | paleontology | sciences

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This learn node features a tiny dinosaur with big canine teeth that the Natural History Museum reports shows for the first time how one of the earliest dinosaurs grew into an adult. The webpage explains:

The turkey-sized reptile called Heterodontosaurus lived around 190 million years ago in the Early Jurassic period and had an unusual combination of molar-like and canine teeth.

Reptiles usually have small same-sized teeth along the length of their mouth but Heterodontosaurus had 2 fang-like canines at the front.

The image posted here is from a video narrated by Dr. Richard Butler, a dinosaur expert at the museum and featured on the page linked above.

For nodes of related learning: An excellent overview article about Anatomy and Physiology of the Reptile Mouth is provided at PetEducation.com. For time frames for the dinosaurs, the big picture can be seen in the Chart of Geological Ages at Connexions.

Learn node: Origins of World War I


Posted on 12th November 2008 by Judy Breck in biography | geography | history

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The Origins of World War I is a lecture from a Yale University on which this learn node is based. The topic is from the Open Yale course France Since 1871 taught by Professor John Merriman, shown teaching in the image. The 45-minute lecture is offered in transcript, mp3 audio, and Flash or Quicktime video. The course overview explains:

The traditional, diplomatic history of World War I is helpful in understanding how a series of hitherto improbable alliances come to be formed in the early years of the twentieth century. In the case of France and Russia, this involves a significant ideological compromise. Along with the history of imperial machinations, however, World War I should be understood in the context of the popular imagination and the growth of nationalist sentiment in Europe.

A major player in the era that led to World War I was Otto von Bismarck. Internet Archive provides his book online: Bismarck, the man and the statesman; being the reflections and reminiscences of Otto, Prince von Bismarck 1898. His image here is from that books frontispiece. The Encyclopedia of 1848 Revolutions is an online source that of a sort the internet has made possible. Dozens of scholars contribute articles to the encyclopedia about the era from in the causes of World War I percolated. The Assassination of Archduke Franz Ferdinand, a kick-off point in World War I, is described in a report in the WWI Document Archive housed at Brigham Young University.

Learn node: steam technology history and practices


Posted on 6th November 2008 by Judy Breck in energy | engineering

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This learn node links out to “The story of steam power [that] stretches from attempts to harness atmospheric pressure in the 1600s to the steam turbines we depend upon today.” (Science Museum Energy Hall, source of the flywheel image above.) A steam industry source, spiraxsarco, provides an excellent steam overview. A US Department of Energy Best Practices page for Steam provides extensive practical information and explains:

Over 45% of all the fuel burned by U.S. manufacturers is consumed to raise steam. Steam is used to heat raw materials and treat semi-finished products. It is also a power source for equipment, as well as for building heat and electricity generation. Many manufacturing facilities can recapture energy through the installation of more efficient steam equipment and processes.

An interesting page on nuclear warfare at Notre Dame Open Courseware includes the mention that military tanks were tried with steam power, but it was the internal combustion engine that made tanks successful.

Learn Node: Trojan War, Troy and Homer ancient Greek history


Posted on 26th October 2008 by Judy Breck in archeaology | geography | history | literature

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This learn node points to the archeology of Troy, the Trojan War memorialized in Homer’s epics, and the century-long story of the rediscovery of the famed ancient city. Troy has not only emerged from thousands of years of burial in the dirt of Anatolia. Troy has come alive out of older printed sources, leaving dusty book shelves to become a shining city in the new virtual world online.

At an educational website sponsored by the Troia Project and the University of Cincinnati, follow an animated timeline, investigate 3-D reconstructions, and explore legends and facts. A Dartmouth University classics lesson provides Troy facts and theories concerning the historicity of the Trojan War. You can visit a work in progress by scholars cataloging Greek, Roman and Byzantine Pottery at Ilion (Troia). The Homer’s Trojan Theater project, hosted at the University of Virginia, provides a look into the mind’s eye of the great classic bard Homer, with battlefield animations in a timeline of The Iliad.

Each of these online projects use digitally-based methods to move far beyond what can be conveyed in print. They are all available globally. The future of learning is emerging through learn nodes like these.

Learn Node: Anglo-Saxon history and literature


Posted on 21st October 2008 by Judy Breck in history | literature

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From this learn node link out to visit virtually the Anglo-Saxon times of Old England. The Ashmolean Museum offers a web-based learning resource aimed at schools and anyone interested in the Anglo-Saxons. It is based on the archive and artefacts held in the Ashmolean Museum. The venerable Bede, great figure of the Anglo-Saxon era, can be studied at Bede’s World — a permanent online exhibition of the Museum of Early Medieval Northumbria at Jarrow that includes topics such as the Anglo-Saxon monastery of St Paul’s, Jarrow, founded in 681/2 AD and St Paul’s Church dedicated in 685 AD. Nearby are Bedes Farm podcasts with audio for guided tours of the online exhibits, source of this post’s farm image.

For a node to learn about the Anglo-Saxon impact that remains up to our times turn to a Modern Poetry lecture from Open Yale courses. These people of long ago echo to us in Ezra Pound: Here is an expatriate poet writing in the voice of the Anglo-Saxon wanderer, a figure deprived of his kinsmen, who is out in the elements, far from land, far from his nation and home.

For much more from the Anglo-Saxons, browse at Georgetown the Labyrinth Old English resources. Western Michigan University’s Medieval Institute has an excellent introduction to The Anglo-Saxons and Their Language and a page at the University of Pittsburgh diagrams Anglo-Saxon church structures.

Learn Node: How Fish Muscles Work


Posted on 14th October 2008 by Judy Breck in biology | general science | sciences

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How fish muscles work from the molecular to the whole organ level is a lecture from the University of Southern Maine that gives focus to this learn node. A basic concept for the subject is that:

Two contrasting behaviors: The first is steady swimming at slow and intermediate speeds using low amplitude axial undulations (i.e. the side to side displacement of the body is small). The second is burst swimming and escape responses using high amplitude axial undulation. In the escape response, a fish bends into a C-like posture then whips its tail in the opposite direction, accelerating a mass of water behind the fish, which causes the fish to accelerate forward. The key is that body bending is small in steady swimming and large in bursts and escapes. Also, the escape response can be very fast, that is less than 1/10th of a second.

The toadfish is an important fish muscle specimen because it has been found that its swim bladder muscles are the fastest twitching muscles in the vertebrate world. The image by Robert Golder shown here is from an article at the Marine Biological Laboratory on this talented but ugly fish. Several articles at the St. Andrews University website of its Fish Muscle Research Group provide the latest ideas and theories in this important subject for mechanics, anatomy, genetics, and aquaculture.

Learn node: Fossil reveals ancient arthropod species chain gang


Posted on 14th October 2008 by Judy Breck in general science | paleontology | sciences

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Early Cambrian arthropod chain gangs this learn node describes are fossilized in chain formation that reveals community behavior. The chain gang 525-million-year-old fossils were found in southern China’s Chengjiang Lagerstatte fossil field. A Science News report of the discovery says that the discovery site is “a treasure trove of fossils often compared to Canada’s Burgess Shale.” The above image from Science News (credit Derek Siviter) shows the that newly discovered species of Early Cambrian arthropod formed sturdy chains of about 20 individuals. In the report:

Nigel Hughes, a paleobiologist from the University of California, Riverside comments that these types of finds provide snapshot scenes of “normal” life.

“Of the millions of fossils, the chances of getting an occurrence where we can determine collective behavior is quite rare,” says coauthor Derek Siveter of the University of Oxford in England. He and his colleagues found 22 complete or partial chains, but only one solitary specimen.

A Brief History of Life on Earth provided at Connexions sets the time frame for these fossils

Learn Node: Dinosaur sinus clues to bird breath

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Posted on 7th October 2008 by Judy Breck in biology | sciences

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Comparing the sinuses in some newly studied dinosaur bones from Argentina with bird anatomy, this learn node from the Public Library of Science lets students go online to peer over the shoulders of working scientists. The drawing is from Figure 1 in the article. In their recent work concerning the the anatomical relationships of dinosaurs and birds, the scientists here tell us:

In this paper, we describe a new large-bodied theropod from the Late Cretaceous of Argentina, Aerosteon riocoloradensis gen. et sp. nov., characterized by cranial and postcranial bones that are exceptionally pneumatic. Some of its postcranial bones show pneumatic hollowing that can be linked to intrathoracic air sacs that are directly involved in lung ventilation. As a result of an extraordinary level of pneumatization, as well as the excellent state of preservation of much of the axial column and girdles, Aerosteon helps to constrain hypotheses for the evolution of avian-style respiration.

For background on the general subject, the University of California Museum of Paleontology has an overview article: Are Birds Really Dinosaurs?

Learn Node: Galileo Pendulum and Spacecraft


Posted on 7th October 2008 by Judy Breck in biography | general science | sciences

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pendulum clock galileo

galileo spacecraft

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Galileo and the Pendulum is a node for learning that is part of a rich cluster and course, The Galileo Project at Connexions. Other sections of the Galileo Project are his biography, family life, the Inquisition, and descriptions of his work on motion, mechanical devices, and the telescope.

Surely the great Galileo Galilei of 14th century Italy would gaze in pride on the achievements of his namesake, the Galileo spacecraft that explored the solar system from 1989-2003.

Learn Node: Radiology Assistant – all about imaging the body


Posted on 26th September 2008 by Judy Breck in biology | health | sciences

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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