Author Archive

Things Change: Remembering the Mt. Saint Helens Volcanic Eruption

May 24th, 2010

Written by Dr. Keith Verner, Founder of LabLearner

On May 16, 1980 I was working as a young biologist for the National Marine Fisheries Service at a field station in the small town of Hammond, Oregon. Jimmy Carter was president and gas was nearly $1.00 per gallon. The field station, an old converted Coast Guard outpost, was located at the mouth of the Columbia River estuary. And for good reason, the Columbia River bar is one of the most deadly bodies of water anywhere.

Field Station in Hammond, Oregon in 1980

Our group studied the Coho and Chinook salmon population that ran annually up the Columbia River. We crisscrossed the massive four-mile wide (6.2km) estuary on a daily basis in our forty-foot fishing boat, the Egret.

One of the things I loved about the estuary was the feeling of its great size and a sense of its permanence. Tides were predictable each day. Juvenile salmon ran downstream after growing to fingerlings in the tributaries where they hatched, and adult salmon ran upstream after growing to enormous size feeding a few years in the Pacific Ocean. Commercial fishermen waited for them and they arrived each year like clockwork. These things were constant. In fact, except for the number of fish, Lewis and Clark saw the same thing we did when they reached the estuary in the first decade of the nineteenth century.

Mt. St. Helens Before Eruption

Perhaps offering even more of a sense of permanence than the estuary itself, was one of the large peaks of the Cascade mountain range, Mt. Saint Helens. On clear days, we saw its 9,677 ft (2,950 m) snow capped profile from the Egret. Even from our distance, we could see the snow cap increase and recede with the change of the seasons. Mt. Saint Helens has stood there for some 50 million years.

One of the most distinctive characteristics of Mt. Saint Helens was its smooth, conical peak – considerably different from the more jagged peaks of Mt. Hood and Mt. Rainer, for example. If one can have a “favorite” mountain, then I would say Mt. Saint Helen was mine for this reason – For its almost perfect, graceful, smooth symmetry from our vantage point. That was Friday.

Two days later, on Sunday, May 18, at 8:32 in the morning, Mt. Saint Helens erupted. With an enormous blast that hurled pulverized rock down the side of the mountain at speeds approaching 670 mph (1080 km/h), Mt. Saint Helens dropped from 9,677 ft (2,950 m) to 8,365 ft (2,550 m) in elevation. It changed from a perfectly smooth cone to a jagged peak. A crater approximately 2 to 3 miles wide (3.2 to 4.8 km) and 2,100 ft (640 m) deep replaced the symmetrical cone within a period of 10 seconds.

Mt. St. Helens After Eruption

After hearing about the eruption, several of us NMFS biologists rushed from home to the field station and scrambled up the three stories of stairs to the lookout tower on the roof. From there, we could clearly see the plume of volcanic ash billowing straight up into the atmosphere, reaching a vertical height of about 80,000 ft (24,400 m), where it then abruptly turned at a ninety-degree angle and headed east, presumably, we thought, because it must have reached the stratosphere. This cloud of ash would eventually come to settle on 11 U.S. states.

Gas, mud, rock, and debris, collectively known as pyroclastic flow, rushed down the side of the mountain at speeds up to 155 mph (250 km/h), destroying trees out to 19 miles (30 km) away, covering highways, and filling in lakes and river valleys with up to 600 ft (180 m) of mud. The flow of material down river valleys eventually reached the Columbia River, dumping enormous amounts of mud and felled trees that would then head downstream to the estuary, where we were, about 70 miles (113 km) from the blast.

Next morning, the field station chief, Terry Durkin, organized a biological and sediment study of fish and benthic (bottom) samples in the river and estuary and we boarded the Egret soon after for a 36-hour, non-stop collection trip. We all knew this was likely a once in a lifetime chance to directly observe the immediate impact of a volcanic eruption on a commercial fishery.

It is difficult to forget the sound of the many Mt. Saint Helens tree logs banging the side of the Egret all night as we worked aboard in the dark. I recall looking over the gunnel into the dark water and seeing bright, baseball-sized objects floating by. We reached down and grabbed one. It was a floating rock from the volcano, a pumice stone. We saw them on the river for several weeks afterward.

The Egret

Mt. Saint Helen is one of the many volcanoes in the Cascade mountain range that extends from Canada to Northern California. During the blast and the mudslides that followed, 57 people were killed. Most of them died on the day of the blast by asphyxiation, being buried alive, or burns. When the pyroclastic flow reached the first humans it was still as hot as 660 oF (349 oC).

The thermo energy released from the blasts was 1,600 times that of the atomic bomb dropped on Hiroshima. In a few seconds, Mt. Saint Helens lost 1,313 ft (400 m) in elevation of solid rock, roughly the height of the Empire State Building. Approximately 13% of the mountain’s volume was gone.

We learned many scientific lessons from our Columbia River estuary studies in May of 1980. Over the years, however, the one thing that “sticks” more than any single detail is the absolute certainty of enormous and awesome change on Earth. With time, forests can evolve into desserts. Lakes can fill in and become grasslands. Given enough time, continents can even drift over the surface of our planet like pumice stones over water. If an entire mountain could be so radically transformed before our very eyes, then nothing is permanent. Things change.

  • Share/Save/Bookmark

Microbes, Beware! Developing a New Kind of “Band-Aid”

May 24th, 2010

Image credit: Zhou, et al. ©2010 American Chemical Society.

Warmer weather and the summer season will soon be upon us.  For many extended time outdoors has the potential to produce more cuts and bruises and ultimately the need for more band-aids.  Although not ready yet, the band-aids of the future may be smarter and more effective at stopping infection if research by a group in England is successful.

Dr. Toby Jenkins and his colleagues at the University of Bath in England have pioneered a new type of dressing for wounds.  His engineered fabric contains small capsule-like vesicles containing antibiotics.  While this may not seem remarkable or different from some of the products on the market, what is different is the way in which bacteria “see” these vesicles.  The vesicles appear to bacteria like human cells that are prime targets for infection.  As a result, bacteria attack the vesicles, bursting them.  The burst releases the antibiotic, which then kills the infecting bacteria and any similar bacteria nearby.  What’s even more amazing is that his preliminary research has shown that the vesicles are only burst by pathogenic but not by non-pathogenic bacteria.  This means that the fabric can be selective in its targets, a major plus when treating wounds on the human body, an area that is covered and filled with many non-pathogenic and even beneficial bacteria.

So how exactly does this fabric work and how can it be selective?  One of the keys to this fabric lies in its ability to select pathogenic bacteria.  Pathogenic bacteria are generally defined as those bacteria that cause disease.  Examples of pathogenic bacteria include Staphylococcus aureas (pneumonia, toxic shock syndrome), Clostridium botulinum (botulism), and Streptococcus pyogenes (strep throat). Examples of non-pathogenic bacteria include certain strains of E.coli which are found in human intestines, Staphylococcus epidermis found as a normal part of human skin, and Lactobacillus acidophilus, a normal part of our intestines.

Structurally and chemically there are differences between pathogenic and non-pathogenic bacteria.  Many of these differences account for why pathogenic bacteria can invade the body and destroy human cells and tissues.  Two of the differences between pathogenic and non-pathogenic bacteria are invasiveness and toxigenesis.  In other words, pathogenic bacteria can invade and overcome host defenses (invasiveness) and can produce toxins (toxigenesis).  Toxins are lipids and proteins that can cause damage to cells and tissues through a variety of mechanisms.  Some toxins are specific such as botulinum neurotoxin, which attacks nerve cells and stops them from firing.  Other toxins are more broad in their actions and simply lyse (break apart) cells or travel through the blood stream and cause effects such as inflammation or inhibition the synthesis of proteins in cells.  Non-pathogenic bacteria are generally defined as those that do not invade tissue or produce toxins.

The idea behind the vesicles on the wound fabric is that they burst as a result of the toxins produced by pathogenic bacteria but remain intact around non-pathogenic bacteria since these bacteria do not produce toxins.  Jenkins and colleagues tested their design by using two types of pathogenic bacteria: Staphylococcus aureas and Pseudomonas aeruginosa and one type of non-pathogenic bacteria: a certain strain of E.coli.  They placed the wound fabric in petri dishes along with each type of bacteria and took samples of the bacteria populations every 20 minutes for 4 hours.  Over that period they found steady decreases in the concentration of the two pathogenic bacteria, Staphylococcus aureas and Pseudomonas aeruginosa, to the point of almost complete inhibition of growth.  In contrast they found almost no reduction in the growth of the E.coli. The very minimal reduction in E.coli growth was attributed to some leaking from the vesicles themselves.  They suggest that these results show the ability of the vesicle-coated fabric to select pathogenic versus non-pathogenic bacteria.  Jenkins and his group are quick to point out that this was a preliminary test and that more research and work needs to be done in order for this type of product to find its ways to hospitals.   One of the next steps is to expand the testing to include many, many more types of bacteria.  Others in the field agree, suggesting that for use in hospitals, a discrimination based only on the ability to produce toxins may not be as effective as other specific criteria.

However, most scientists in the field see this preliminary work as a step in the right direction, particularly since the medical field is facing a new era of antibiotic resistance.  Many theorize that this type of “smart” wound fabric would help to curb the rapid pace of antibiotic resistance since the antibiotic would only be released if pathogenic bacteria are “on site.”   This mechanism would reduce what scientists term “the selection pressure” on bacteria that helps drive the evolution of resistance to antibiotics.

For LabLearner students the research in this article emphasizes some of the major concepts they encounter in CELLs and GAP Units such as Cellular Organization, Genes and Proteins, Properties of Matter, Chemical Reactions, Adaptation, Classification. These concepts include an understanding of cellular membranes, organism and cellular reproduction, specificity of chemical reactions and selection, evolution and adaptation.   In addition it highlights the combination of problem solving and experimental design that students experience in LabLearner Labs and Performance Assessments.  And who knows where this research and research by LabLearner students will take us.  The next time you’re looking for band-aids, you might find the answer.

If you’re interested in learning more about bacterial pathogenesis or the evolution of antibiotic resistance check out these links:

The Microbial World: Bacterial Resistance to Antibiotics

The Microbial World: The Mechanisms of Bacterial Pathogenicity

  • Share/Save/Bookmark

LabLearner Introduces New High School Program: Exploration21

April 21st, 2010

Experts agree that one of the major problems with American science education is that it is a “mile wide and an inch deep”. That is, we tend to cover too many different subjects too superficially. We plow through massive, expensive textbooks, covering chapter after chapter, never spending enough time on any topic for students to really understand what they are learning. We test and quiz regularly while students can still remember what they have been told or read. This doesn’t work for most students. Few remember a thing, let alone are able to apply what they have learned.

As many readers know very well, Cognitive Learning Systems’ preK-8 science education system, LabLearnerTM, was designed to address all of these issues. We have been successful in applying cutting edge knowledge from cognitive neuroscience and education theory to create an innovative system that consists of a full curriculum, functioning in-school lab, teacher professional development, and ongoing program support. Since its roll out, LabLearner has rapidly spread across the country into both public and private schools. However, once LabLearner students leave eighth grade and enter high school, they’re often well ahead of their peers who have not experienced LabLearner science education and are faced with a steady diet of lectures and textbook assignments rather than meaningful lab experiences and problem-solving activities.

Now, at the request of high school administrators who enroll students from LabLearner middle schools, Cognitive Learning Systems is introducing its first high school science education program for the ninth grade, Exploration21TM. Exploration 21 offers in-depth, cross-disciplinary science education by focusing the entire academic year on only three units, or “Sectors”, designed to be of particular interest to first-year high school students. The first Sector, ASTEROID IMPACT, is based on the real-life asteroid, Apophis, which will arrive near the Earth in 2029. In the second Sector, CONCUSSION, students follow a ninth-grade soccer player, Nickie, as she recovers from a head injury obtained in a game. The third Sector, NASCAR, focuses on the physics, chemistry, and biology involved in racing.

Not only does focusing the curriculum on just three Sectors allow in-depth coverage of each subject, but the very nature of the Sectors are such that they can be used to teach scientific concepts across the entire spectrum of state and federal science education standards. Also, unlike other curricula, Exploration21 addresses each and every scientific concept in real-life context, with weekly hands-on laboratories. Each Sector spans months, as opposed to days or weeks. Simply stated, Exploration21 is the antithesis of “mile wide, inch deep” science education! As in all other Cognitive Learning Systems programs, students learn rigorous science because they are interested and are having fun while learning!

Exploration21 will first be introduced to ninth grade students at Archbishop Wood High School in the Archdiocese of Philadelphia this Fall! Exploration21 will then become available for national distribution for the 2011/12 school year. We are looking forward to working with Archbishop Wood principal, Mary Harkins, and her science faculty to bring the very best in science education to their students. Watch for more information as it becomes available on the Exploration21 website at exploration21.com.

  • Share/Save/Bookmark

Photosynthesis: A Scientist’s Guide to Alternative Energy?

April 21st, 2010

By: Dr. Christine Jurasinski; LabLearner Staff Scientist

“Why do we need to understand photosynthesis?” This may be a question that students all over the world, including LabLearner students ask. For many, the information about a plant process may seem unrelated to their current or future interests. But, what research has shown us over and over again is that one never knows how fields, concepts, and technology will interact. Some of the latest research from MIT proves just that.

Dr. Angela Belcher and colleagues have found a way to use a photosynthetic-like process to split water in order to create hydrogen fuel. For years, researchers have been contemplating how to create this type of artificial photosynthesis. Dr. Belcher and her team now appear to have taken the first step in not only creating artificial photosynthesis but also in using it as a way to produce alternative fuels.

From an energy level, LabLearner students should recall that photosynthesis involves the conversion of light to chemical energy. Light from the sun is used to drive a chemical reaction which produces oxygen and sugars from carbon dioxide and water. Many will recognize the chemical equation for this overall process

Although the equation above makes it appear as if all of this occurs in one step, in reality, photosynthesis involves many steps and reactions. Essential to the process are plant pigments including the pigment chlorophyll. Plant pigments absorb or capture photons and thus the energy of light. Ultimately, in most plants, the energy is transferred to molecules of chlorophyll. Once absorbed, this energy then causes the transfer of electrons from chlorophyll molecules to other molecules within a plant’s cell. These molecules in turn transport electrons to other molecules. This process is called electron transfer and produces energy. This energy is used to drive the reactions that produce sugar from carbon dioxide. In addition, as a part of this electron transfer, water molecules are split producing hydrogen and oxygen.

Dr. Belcher and her colleagues have mimicked these processes on a nano-scale. To do this they used a harmless virus called M13, a pigment called zinc porphyrin, and a catalyst called iridium oxide. They altered the virus so that it would attract and bind to the molecules of pigment and catalyst. The final structure resembled a thin wire with a coating around it. The virus was the wire and the pigments and catalysts the coating. When exposed to sunlight, the pigments absorbed photons of light and transferred energy down the length of the virus/wire much like the chlorphyll and other pigments in plants. This energy was then used by the catalyst to split water that surrounded the virus/wire into oxygen and protons and electrons; a process similar to that which occurs during electron transfer in plant cells.

(image: A computer visualization of the biologically-based system shows the virus itself (in yellow) with molecules of pigment (in pink) and of the metal catalyst (brown spheres) attached to its surface. The pigment and catalyst cause water molecules to split apart when they come in contact. Click on image to view original article. Graphic courtesy of Angela Belcher.)

Once the protons and electrons produced from the splitting of water re-combine, hydrogen can be produced. It is this last half of the process on which Dr. Belcher and colleagues are currently working. They anticipate completing this last step as well as making a more affordable prototype for artificial photosynthesis within the next two years.

So why is all of this important and how does it relate to what LabLearner students learn? Well, currently water can be split, and hydrogen made using electricity. However, the generation of electricity often comes from fossil fuels. Other researchers have used solar panels to produce electricity, which is then used to split water, but this system is less efficient because of its multiple steps. The system created by Dr. Belcher would skip many of the intermediate steps and create hydrogen directly from sunlight, just like photosynthesis. If this type of system can be created on a larger scale, solar energy could be used to split water into oxygen and hydrogen. The hydrogen could be stored in fuel cells and then used later to produce electricity or converted into other liquid fuels. The result would be a more efficient and “green” method of producing alternative fuels.

As for relating to the LabLearner curriculum, artificial photosynthesis requires knowledge of the photosynthetic process, properties of light, energy transfer, chemical reactions, and electron flow. These topics are those studied by both elementary and middle school students in CELLs such as Chemistry, Matter and Interactions, Forms of Energy, Light, Exploring Electricity, Chemical Reactions, Electricity and Magnetism, Photosynthesis, and Light and Optics.

Finally, consider whether this and future research would evolve if Dr. Belcher and others had never learned about photosynthesis. Her research as well as that of researchers in all other fields is showing us that the future lies in the combination rather than the isolation of knowledge. You just never know when you will use what you’ve learned and how it will affect the future.

  • Share/Save/Bookmark

Light As A Neuronal Switch

March 29th, 2010

Dr. Christine Jurasinski
LabLearner Staff Scientist


How can you control brain activity?  It’s a question that has fascinated us for centuries.  Now, new research suggests that one way may lie with a strategy called optogenetics- the combination of optical and genetics techniques.

Neuroengineer Edward Boyden and his colleagues at MIT have recently discovered a way to use optogenetics to turn neurons within the brain on and off by simply exposing them to a certain wavelength of light.  Their research has far reaching implications for the treatment of conditions such as epilepsy, chronic pain and post-traumatic stress disorder as well as providing a new way for understanding and studying cognition, emotion and other functions of the brain.

Boyden and his collaborators discovered a protein found in a special type of bacteria called archeabacteria that inhabits the Dead Sea. Archeabacteria are a type of bacteria that tend to inhabit extreme environments like hot springs, arctic environment, sulfurous springs or the high salt concentration of the Dead Sea.

The protein they discovered acts as a pump in cells, moving protons out of the cells when active.  They also discovered that this protein, called the Arch protein, can be activated or turned on by light of yellow/green wavelength. Because protons carry a single positive charge, the movement of protons out of a cell changes the voltage within the cell.  The inside of the cell becomes more negative as compared to the outside of the cell.  As neurons work in part through electrical signals, changes in voltage are key to controlling their activity and their ability to fire and signal other neurons.

But, it’s what came next that illustrates that controlling the brain through light may not be as far off in the future as it seems.  These researchers engineered the neurons of mice to produce the Arch protein.  They then implanted a light source in the brain of the mice and found that when the Arch protein was activated in the neurons by the yellow/green light, it pumped protons outside the cells.  As a result the voltage inside the neurons dropped and stopped them from firing! In essence the researchers were able to use light to stop neurons within the brain from firing, silencing an area of the brain.

Once the light was turned off, the Arch protein turned off and “reset” itself.  Within seconds it was able to be activated by light again.  Thus, a combination of yellow/green light and the Arch protein, acted as an “electrical switch” for neurons controlling their active and inactive state.

In addition to the Arch protein, Boyden and his colleagues have found several other proton pumps that respond to other wavelengths of light including those in the red and blue ends of the spectrum.  What they hope is that by combining the different proteins and wavelengths of light different neurons and different areas of the brain could be controlled simultaneously.

How does this related to LabLearner students? Students in the LabLearner Program spend time in 4th and 6th grade studying the properties of light including how absorption and transmission of different wavelengths of light affect our perception of color and control biological processes such as photosynthesis.  This new research shows that understanding light and its properties may be just as important in uncovering the processes of cognition, emotion and in treating brain disorders and diseases.

  • Share/Save/Bookmark

Thinking About Evolution? Think Lizards!

March 29th, 2010

Dr. Christine Jurasinski
LabLearner Staff Scientist


Mutation, allele, gene.  What do you think of when you hear these words?  Perhaps DNA comes to mind or disease or the workings of a cell.  But what about evolution?  For many, evolution brings to mind words like Darwin, finches, beaks, and fossils rather than mutations, alleles and genes.

But what about LabLearner students?  While they may begin their exploration of evolution, adaptation, mutations and natural selection by focusing on each of these topics in discrete CELLs such as Ecosystems and Adaptation,  Inheritance and Adaptation, and Genes and Proteins, they have the opportunity to combine all of this knowledge into a more complex and more scientifically “real” concept in the 7th grade CELL Adaptation: a CELL that sets them up for understanding some of the latest research into the molecular mechanisms for how species adapt and evolve.

This newest research comes out of the lab of Dr. Erica Rosenblum of the University of Idaho.  She and her colleagues have uncovered some intriguing information about the genetic process of evolution.  Their research is centered around three species of lizards. Each of these three species exist with dark skin in many areas around the world but have evolved a white skinned variation in the White Sands of New Mexico.  And what strikes the researchers as amazing is that in two of the species, it was accomplished by DIFFERENT MUTATIONS in the SAME GENE.  Even more interesting is that one mutation is DOMINANT while the other is RECESSIVE.

As fifth grade LabLearner students learn, many organisms have two copies of each gene.  One copy on one chromosome.  The other on the other chromosome.  The two copies of the gene are called alleles.  In one of the simplest examples of inheritance of traits, one allele is dominant the other is recessive.  Organisms with two dominant alleles will show the dominant version of a trait such as brown fur.  Organisms with one dominant and one recessive allele will also have the dominant brown fur trait.  However, organisms with two recessive alleles will have the recessive trait of white fur.

What Dr. Rosenblum discovered was that in one species of lizard, the white skin was the result of a dominant allele but in the other species of lizard, the white skin was the result of a recessive allele.  In both cases, the lizards evolved from having brown skin, but it was through different methods of inheritance.

How did this happen?  The answer involves selection pressure and mutations.  About 5000 to 7000 years ago, evaporating lakes in that area of New Mexico left behind huge deposits of gypsum which eroded away leaving an entirely white area of desert in what had once been a brown area.  Lizards which had been living there were brown skinned, which served as excellent camouflage from aerial predators.  However, as the terrain began to change, brown skin against and increasingly white background no longer served to camouflage the lizards, making them easy prey.

What scientists believe happened is that a mutation, a change in the DNA in the gene that controls the color of pigment in the lizards’ skin occurred.  This mutation may have occurred before but would not have likely been retained in the lizard population because white skinned lizards in a brown desert would have been an easy target for predators.  However, a mutation that occurred when the sands were white would have produced white skinned lizards that blended in with their surroundings.  These lizards would have been more likely than the brown skinned lizards to survive to produce offspring.  These offspring would have the mutated gene for producing white skin.  Thus, more and more lizards with allele for white skin would be born because the white sands now “selected for” this allele.

In one species of lizard, the mutation was dominant meaning the trait produced by the gene required only one copy of the gene in order for the skin to be white. The gene on only one chromosome had to be present. In the other species of the lizard, the mutation was recessive.  In other words, in order for the skin to be white, both copies of the mutated gene (one on each chromosome) had to be present.

For 7th grade LabLearner students, this real life example with the lizards epitomizes the concepts they have learned in the Adaptation and Genes and Proteins CELLs.  Evolution and natural selection occur because of changes in DNA.  Changes in DNA can result in differences in proteins and thus traits produced in an organism.  These types of changes can be seen by looking at the frequency of alleles for a trait.  If one trait is selected over another than the allele which produces that trait will appear more frequently in the population.  This is what Dr. Rosenblum and her colleagues would expect to see when comparing the alleles for skin color in lizards in the White Sands area to those same species of lizards in other areas of the world with a brown habitat.

For LabLearner students, the next question would be:

Which species of lizard would you expect to evolve faster, the ones with the dominant or recessive allele?

Based on what they know about modes of inheritance, those 7th grades and even 5th graders should predict—lizards with the dominant allele.  It’s what Dr. Rosenblum predicts and what she and her colleagues will continue to explore.

From her research and those of so many others we see that evolution and our study of it continues. What makes it different from Darwin’s time is that we now have the molecular tools to better understand how and why.

  • Share/Save/Bookmark

Uncovering the Principles Behind the Chilean Earthquake and Tsunamis

March 1st, 2010


Dr. Christine Jurasinski
LabLearner Staff Scientist

On Saturday February 27th, the world was once again reminded of the awesome forces that are at work on our planet as an earthquake awakened Chileans in the early morning. The earthquake, which was centered just off the coast of Chile, measured an 8.8 on the Richter scale and generated enough force to generate tsunamis across the Pacific Ocean. The quake came only a day after a 7.0 earthquake in Ryukyu, Japan and a month and a half after the 7.0 earthquake that devastated Haiti.

What is happening here? Are we experiencing more earthquakes than in previous periods of history? While the answer is likely “No, we just are a more populated and therefore a more aware, more affected and more technologically savvy planet than in the past.” these are questions that scientists are actively researching. Their research takes them into the fields not only of geology, but also physics, fields that LabLearner students explore as they investigate principles in CELLs such as Forms of Energy, Earth’s Forces, Potential and Kinetic Energy, and Sound Waves and Pressure and in GAP Units such as Earth’s Changing Surface, The Changing Earth, and Geologic Time.

The earthquake that struck Chile occurred along the boundary that separates two tectonic plates: the Nazca Plate and the South American Plate.

As LabLearner students learn in the The Changing Earth GAP, this is a type of convergent boundary known as a subduction zone. In this particular boundary the Nazca plate moves below or beneath the South American Plate at a rate of 8.9 cm per year.

As this occurs, there are places in which the plates encounter resistance and get stuck. Tension builds between the plates until it becomes so great that the plates “rupture.” To understand rupture, think of a safety pin with the needle of the pin tucked safely under the protective casing. When the needle is depressed and moved out of the area of the casing, it springs open. There is a recoil associated with the release of the needle. This is similar to what happened on Saturday. The two plates were stuck and the tension was so great that the crust on the South American plate suddenly “sprung” above the Nazca plate. As a result, the Earth’s crust was lifted and then settled. This type of movement is called elastic rebound and results, as you can imagine, in the displacement of the Earth’s surface.

However, what seems relatively mild in description produces devastating results. Much of the damage in an earthquake is due to this elastic rebound. However, seismic waves, which are generated as the rupture occurs, also contribute to the devastation. Seismic waves are essentially sound waves that originate from the earth as the rupture is occurring. As the rupture occurs, the waves move the particles of earth in different directions. P waves are seismic longitudinal waves that alternately compress and expand particles of the solid and liquid portion of the Earth through which they move. LabLearner students studying the Sound Waves and Pressure CELL should be familiar with these types of waves as longitudinal waves are responsible for the generation of sound in solids, liquids and gases. In addition to P waves, the rupture causes another type of deep wave within the Earth’s surface called S waves and two types of waves on the surface of the Earth. It is the surface waves that cause additional horizontal and vertical movement of the Earth’s crust and much of the damage from an earthquake.

But as illustrated by Saturday’s event in Chile, the damage caused by the earthquake itself may not be the only concern. Often earthquakes can set off tsunamis- huge masses of moving water that when coming ashore produce their own destruction to both coast and inland areas. Tsunamis occur when there is a significant enough displacement of water to generate waves that have incredibly long wavelengths. They can be caused by earthquakes such as the one in Chile, by volcanic eruptions, and by landslides. Much of what is understood about tsunamis is still evolving.

One of the most devastating tsunamis occurred on December 26, 2004 off the coast of Sumatra and much of what we understand and how we predict tsunamis has come from that event. Luckily the tsunamis that resulted from Chilean earthquake on February 27th were nowhere near the same power. So, how were the tsunamis this past weekend generated?

Again, imagine the events that happened between the two converging plates. The build up of tension resulted in the plates that were “stuck” to suddenly move. In doing this, the South American plate was vaulted upward momentarily and then came back down. What then happened was the column of water above the plate was also pushed upward and then pulled back down by gravity. The result was a wave with a crest and trough that then spread outward like a ripple in a pond creating multiple waves extending from the epicenter of the quake. The energy that drove those waves came from the potential energy of the water as it was lifted. As gravity acted on the uplifted water, the gravitational potential energy was transferred into the kinetic energy of a moving wave. The higher the lift, the greater the potential energy and the greater the kinetic energy of the wave, a concept that LabLearner students explore in the Forms of Energy and Kinetic and Potential Energy CELLs.

What makes tsunami waves different from other types of ocean waves are their potentially crippling power. This power stems in part from their incredibly long wavelengths. As students learn in the Sound Waves and Pressure CELL, the wavelength is the distance between the crest or trough of one wave to the crest or trough of another. The ocean waves generated by wind that we are used to seeing have wavelengths of about 150 m. Tsunami waves are longitudinal waves that have wavelengths of 100 km. This means that normal ocean waves occur with a wave passing approximately every 10 seconds where as the time between successive waves in a tsunami can be more on the order of one every hour. In addition, tsunami waves move at incredible speeds such as 700 km/hr, which means they can travel huge distances across an ocean without losing much energy.

But one of the most intriguing things about tsunamis is the relationship between the height of the wave, its wavelength and the depth of the water. Tsunami waves generated in deep water tend to have relatively small amplitudes (heights) and long wavelengths. This is because the mass and energy of the wave is spread over a large and deep column of water. Thus, when these waves are in the open ocean they are only a few centimeters high and not easily detected by ships or cameras. As a result, tsunami waves are considered shallow water waves. As the tsunami wave moves closer to shore, the rising land of the continental slope or shore decrease the depth of water. Because of the Law of Conservation of Energy, the wavelength of the wave decreases and the height or amplitude of the wave increases. Although the wave slows from 700 km/hr (500 mph) to 50 km/hr (30 mph) as a result of friction with the land and as a result of a decrease in water depth, the incredible energy of the wave is “compacted” into a series of waves closer together and with much greater heights. Waves that impact the shore can be up to 9 meters (30 ft) in height. Thus, these waves can contain an enormous amount of energy and may move water inland for miles with great force. In addition, tsunami waves often do not break like normal ocean waves and dissipate energy. Rather, they move in like tides as great walls of water.

The tsunamis of December 26, 2004 were such waves. Luckily, the tsunamis of February 2010 were not. Tsunamis did reach Hawaii, Japan, the Philippines and the west coast of the United States. However, the amplitude of the waves as the reached shore ranged from several centimeters to approximately 1.8 meters (6 feet). Why these tsunamis differed from those that occurred in Sumatra will be heavily investigated for months to come.

However, what is becoming clear is that at this time in our species history, we can benefit from engaging our students’ interest in the forces that drive and govern our planet. Enhancing their understanding of the geology, physics, chemistry and biology of our planet can ultimately lead to better predictive models, warning systems, preparedness and even solutions in our planet’s future.

Find out more about both earthquakes and tsunamis by investigating the links below.

Tsunamis

http://walrus.wr.usgs.gov/tsunami/basics.html
http://www.ess.washington.edu/tsunami/index.html
http://www.pbs.org/wgbh/nova/tsunami/anatomy.html
http://www.tsunami.noaa.gov/
http://www.tsunami.noaa.gov/tsunami_story.html
http://www.pbs.org/wnet/savageearth/tsunami/index.html
http://faculty.gvsu.edu/videticp/waves.htm

Earthquakes

http://www.pbs.org/wnet/savageearth/index.html
http://www.seismo.unr.edu/ftp/pub/louie/class/100/seismic-waves.html
http://www.geo.mtu.edu/UPSeis/waves.html
http://pubs.usgs.gov/gip/dynamic/dynamic.html

  • Share/Save/Bookmark

Want Information? LabLearnerLinks to the Rescue!

January 21st, 2010

A Message from the President
Dr. Keith Verner

As all LabLearner students, teachers, and parents know, the LabLearner program does not assign a particular textbook. Since it is a 100% hands-on curriculum, most of the learning that occurs in LabLearner takes place in the lab, through first-hand observation. However, students obtain additional scientific information in their workbooks (Scientist Data Records), lecture notes, and NOW on the web.

The Internet is an exceptionally good source of information for LabLearner students. First, there is a nearly limitless number of excellent websites focused on essentially every science topic imaginable. Second, the form of information on the Internet is multimedia in nature. One may easily find live color video transmissions from the surface of Mars, virtual experiments involving essentially any physics principle, extensive photographs and video of every ecological biome on Earth, or a millimeter-by-millimeter trip through a real human body – all in color and with sound if necessary! In addition, students may download, store, and share absolutely any information they find with their teachers and peers. It is simply impossible to duplicate such a resource with any textbook.

It is also important to consider that the form of information available on the Internet – its multimedia, interactive nature – plays directly into the hands of K-8 LabLearner students. This is the form of information that they are brought up with and will need to use every day in the future, regardless of where they go to school, college, or where their careers ultimately take them. How many of us adults, in our professional work, find ourselves on the phone looking at the same website as the person we are talking to. How many times have we ended the discussion with something like “OK, I’ve just sent you the link.” or “I’ll print that for the staff meeting tomorrow?” LabLearner students can use the Internet exactly the same way… it is the future.

Finally, it is easy to find scientific websites directed at virtually any age/grade level. For example, if one types in – heat transfer eighth grade – into Google, over 32,000 sites appear, while if only – heat transfer – is typed in, over 36,000,000 hits are obtained! It is amazing how quickly information can be filtered on the web. On the other hand, it is still a daunting task for LabLearner students, teachers, or parents to pick the most relevant of these sites to relate to specific LabLearner curriculum CELLs. Therefore, LabLearner has done this for them. Our new LabLearnerLinks website provides from three to five relevant, quality websites for each curriculum CELL. It’s that simple.

It is our hope that LabLearnerLinks will be the beginning of a lifelong relationship between the search for scientific knowledge and the Internet, for all of our students, their teachers, and parents.

  • Share/Save/Bookmark

Imaging Cancer: Taking Microscopy to the Next Level

January 21st, 2010

Dr. Christine Jurasinski
LabLearner Staff Scientist

What do you get when you combine a microscope, lasers, a mouse and some fluorescently labeled molecules? Well, if you are Erik Sahai and colleagues, you get the opportunity to discover why some cancer cells spread and why some do not.

In October 2009, Sahai published results that showed that a special protein called Transforming Growth Factor Beta (TGF β) acted as a signal for single breast cancer cells to leave a tumor and move through the blood to other areas of the body. What is even more fascinating is that he and his colleagues were able to visualize and capture the moving single breast cancer cells on video while these cells were still inside a living, breathing mouse!

So how was this research performed and how does it relate to what LabLearner students are currently studying? For LabLearner students, Sahai’s research combines concepts of microscopy, light, optics, proteins, cells and cancer that students investigate in the Microscopic Explorations, Light and Optics, Light, Genes and Proteins, and Cell Cycle and Cancer CELLs.

Although the Microscopic Explorations CELL is not the first time LabLearner students work with the compound microscope, it is the first time they use it to investigate animal, plant and bacterial cells. In this CELL students explore how changes in resolution and field of view can provide different types of information about cells and the structures within CELLs. Understanding these concepts provides the groundwork for the principles of microscopy and a framework for thinking about how microscopy can be used to study various cellular and microscopic questions. In the case of this latest research, students may be surprised to find that microscopy can be performed on living tissues and animals. However, when discussed, student should be able to understand the terms resolution and field of view and to appreciate some of the differences between their compound microscope and the confocal microscope used in this research.

For 4th and 6th grade students who perform the Light and Optics and Light CELLs, this latest discovery illustrates how knowledge of the electromagnetic spectrum and the wavelength of light can be applied in the forms of lasers and in the field of microscopy.

For 7th grade students, Sahai’s research provides an example of how concepts they learned from the Genes and Proteins and Cell Cycle and Cancer CELLs are not separate, but rather merge as scientists approach “real-life” problems. From these two CELLs, students should understand that cells proceed through a programmed sequences of events called the cell cycle that result in DNA synthesis and cell division. During the cell cycle, proteins are produced from a series of processes involving DNA and RNA. Changes in genes and proteins can result in changes in how the cell cycle is regulated, and some changes in cell cycle regulation can result in cancer and in the metastasis of cancer cells.

This newest research illustrates only one of the signals that scientists think causes cancer cells to metastasize. To answer the question of why some cancer cells leave a tumor and others do not, Sahai and his colleagues attached a fluorescent molecule to a protein located within breast cancer cells in mice. The protein would “glow” blue when it was activated. This protein was special in that another protein called TFG β could only activate it or turn it on. As a result, if TGF β turned on the protein, it glowed blue. Sahai then used a technique called multiphoton confocal microscopy to visualize the breast cancer cells within the mice. Multiphoton confocal microscopy is unique in that it is a non-invasive way to look at cells within a specimen, culture of living cells, living tissue or living organism. It involves using a laser to excite the fluorescent molecules in a sample. The laser sends a certain wavelength of light through the specimen. When the light hits the fluorescent molecule, another wavelength or “color” of light is given off. In this case, the color blue. A scanner at another part of the microscope detects the blue light and records its presence. All of this happens over a very small space of the sample. As the laser moves through the sample, any fluorescent light is recorded. Computers then build a digital, three-dimensional image of the fluorescent area of the sample.

For this study, mice that had fluorescently labeled proteins in their cells were given anesthesia and placed under the objective of the confocal microscope. The laser was then able to non-invasively scan or “section” the area of the breast cancer tumor as well as other areas of the body. Using this technique, Sahai and his colleagues were able to show that single cells that broke off of the tumor “glowed blue.” That is, they received a signal from the protein TFG β. Sahai was able to follow these cells as they traveled through the blood to other areas of the body including the lungs. In addition, the researchers found that while the genes activated by TFG β were turned on, the breast cancer cells could move but could NOT attach to other organs. Only when the genes activated by TFG β were turned off (the cells no longer glowed blue) could the cancer cells attach to other organs. In other words, TFG β acted as a switch for the activity of the single cancer cells. When genes were turned on by TGF β, the cancer cells could metastasize (move), but they could not attach to an organ or further divide. Only when the signal from TGF β was no longer present could the cancer cells attach to an organ and begin dividing and creating another tumor.

In contrast, Sahai found that cancer cells that broke off in clumps from the tumor were NOT activated by TFG β. That is they did not glow blue. Because these cells broke off in clumps, they could not cross the lymphatic barrier from the tissue into the blood and stayed within the breast tissue. That is they were unable to metastasize to other areas of the body.

These finding represent a significant leap in understanding how metastases occur and which cells present the most danger for the spread of cancer.

As for LabLearner students, Sahai’s research illustrates exactly what the power of combining concepts can do. His research takes us one step closer to understanding the spread of cancer and to potential new therapies that can be used to stop and treat the disease.

  • Share/Save/Bookmark

LabLearner November Newsletter: Catching up – What works when students miss a lab?

November 15th, 2009

Tina Bryn                                                                 LabLearner Teacher

With school back in session and flu season fast approaching, many of us teachers find ourselves asking the same question.  ‘What are we going to do to catch children up who miss labs and discussions?’

The answer to this ‘simple’ question is not so easy.  We need to look at some different variables. When having to schedule lab times it is difficult to have a student make-up a lab.  Here is one way that I used to catch a student up; I had the student who missed time just discuss with his/her group and ask what happened.  I found this strategy to be ineffective.  What ended up happening is the group members would just let the student copy his/her student data record. Instead of relying on their group members I would have the student just get the data information and then make sure they were present for the post lab discussions. This doesn’t seem to affect the auditory learners, but in some cases the kinesthetic and visual learners will need the lab to associate and put all the pieces of the puzzle together.

Another approach that I have tried this year is to have the student watch the video of the lab process, give him/her data, and discuss what they would have observed in the lab.  They will get the rest of the concepts when we discuss the questions in the post lab and focus questions the following days.  If a student misses multiple days I will meet with the student individually before, after, or during school.  I follow this same process as I mentioned above.  My only concern is that the student is not able to acquire the hands on experience and see the results of the investigations or get rephrasing in the class discussions.  The only down fall I have noticed is that when missing multiple labs, the student doesn’t perform as well on the post-test.

Knowing our students as well as we do, we will be able to decide which ones will need the hands on part for some of the labs.  With this in mind I have meet with some students before or afterschool and we will do the lab together.  I will have as much set up before hand as possible.  Obviously this takes extra time on the part of the teacher and in most cases time doesn’t allow for this.

As a teacher, I also look at the student’s strengths and weaknesses to best fit their needs of understanding concepts.  I have found that if a student only misses a day or two, it is easy to catch the student up since discussion is on the same concepts for a month.  However, this year I am finding students missing weeks at a time, and this is why I am trying the video and discussion method.  The hard part about this is that the lower elementary doesn’t have videos available.

Lower elementary teachers seem to be approaching this idea from different angles.  Some of the teachers have waited to do the lab day until all of the students are present.  This is easier for the lower elementary since teachers do not need to do a lab every week to complete the curriculum before the end of the school year.  Other teachers have chosen to go ahead with the lab making sure that the student is in attendance during the post lab, or had a peer explain what they observed during the lab.  This seems to work with the lower elementary.  Not only does the missing child get caught up with what happened, but the student getting to do the explanation is reviewing the concepts in his/her own words without even realizing it.

One teacher that I have visited with has even sent home labs to be done with the parents.  With us being a small rural school we get to know our families well.  She doesn’t send home the missed lab with all students, but she will send it home with parents that she’s knows will do the lab and return the materials.  She has done this twice in the last two years with good results.  One was the Exploring Electricity investigation 3 and the other one was the Property of Matter investigation 4.  Both times she gathered the needed materials and using one of the experiment only containers, sent everything home.  She found this way to be beneficial.  The student didn’t miss the lab and she wasn’t trying to find the time to fill the student in on what was missed.  Understand that this won’t work with all families.  She doesn’t do this will all labs or all parents; just easy to do labs and to parents that are involved and will complete it.  The student is then able to become involved with the post-lab discussions and not just have to sit back and listen.

Tina Bryn – I teach for the Barnes County North School District at the North Central campus near Rogers, North Dakota.  We are a K-12 school with an enrollment of about 155 students.  I teach 6th grade, except for Social Studies, and 7th and 8th grade Science.  This is my third year teaching the middle school curriculum for LabLearner.  Being a kinesthetic learner myself, I love the lab base approach.  I also love this program from a parent standpoint.  My children are in preschool, first grade, and third grade, and they are already loving science and using terminology that I didn’t use until much later.

  • Share/Save/Bookmark