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.

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

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

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.

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.

Dr. Christine Jurasinski                     LabLearner Staff Scientist

Interdependence.  It’s a word that comes up when talking about virtually everything in today’s world, from climate change to the global economy.  When students in the LabLearner Program hear it they are likely to think about ecosystems and the relationship between producers, consumers and detrivores (decomposers such as scavengers, and microbes), and between prey and predator. For 4^th grade LabLearner students, interdependence is explored through their study of food chains and food webs in the Ecosystems and Adaptation CELL. 8^th grade LabLearner students take this knowledge farther investigating the flow of energy and biomass within ecosystems in the Ecosystems CELL. In addition, both elementary and middle school LabLearner students focus on how competition between herbivores or predation of herbivores by carnivores could increase or decrease the production of producers.  For example, the more herbivores killed by carnivores or omnivores, the fewer herbivores to consume producers and the more producer biomass that will result.

This concept of the effect of competition and predator/prey relationship on producers has long been thought to be the mechanism by which carnivores influenced the diversity and abundance of producers in ecosystems.  Now, new research from wildlife biologists at Michigan Technological University has suggested that carnivores may have a more direct and important effect on producers and the diversity of producers within ecosystems.

Joseph Bump, Rolf Peterson and John Vucetich have been studying the relationship between two parts of the ecosystem at Isle Royale National Park in Michigan: moose (herbivores) and wolves (carnivores).  Their most recent findings have produced what they describe as a somewhat surprising link between the prey/predator relationship and the producers in the ecosystem.   Bump, Peterson and Vucetich studied a 50 year record of the moose/wolf relationship that included observing the location of over 3600 moose carcasses. In addition, they conducted a 3.5 year study that compared the plant growth, soil microbes and fungi,  and nutrient deposition in plant leaves and soil from control sites and those containing carcasses of wolf killed moose.  Control sites were those that did not have moose carcasses. What they found was that soil at the wolf killed moose sites had 100 to 600 percent more potassium, nitrogen and phosphorus than soil at the control sites.  In addition, plants from the wolf killed moose sites possessed 25 to almost 50 percent more nitrogen than plants from control sites.  Bacteria and fungi were also higher at the wolf killed moose sites than the control sites.

When they combined this data with the 50 year record of moose carcasses what they found were “hot spots” of forest fertility- places in which nutrient, microbe and plant life were enriched.   In essence, the researchers say that the wolf/moose prey/predator relationship created a cycle in which the decomposition of moose carcasses increased the nutrient deposition of the soil, resulting in an increase in the amount of plant (producer) biomass and an increase in the nutrient composition of the plants.  Moose, which are attracted to nitrogen rich plants, were then drawn to these nutrient rich locations, depositing feces and urine further increasing the nutrient deposition into the soil.  In addition, the increase in moose frequency to these areas increased the likelihood of predation by wolves and ultimately the increase of even more moose carcasses.

While these findings may seem intuitive, they are shockingly new to the study of ecosystems, which up to this point, has not had evidence of such a direct relationship between predators and soil fertility.   In addition, the finding also suggests that there may be a direct relationship between predator activity and producer (plant) diversity because changes in nutrient availability often promote competition between different tree seedlings.  Thus, the diversity and location of producers within an ecosystem may be directly related to predator behavior – a relationship that once seemed as unrelated as oil and water.  Now, it’s just another example of interdependence.

Dr. Christine Jurasinski                         LabLearner Staff Scientist

What images does the word “fungi” bring to mind? Well, chances are they’re not images of weathering or erosion. Yet, a recent discovery by researchers in Great Britain has shown that fungi play a significant role in the erosion process.

For years, scientists have known that the roots of plants and trees contribute to the erosion of rock. Ask a 6^th grade LabLearner student about the causes of erosion and weathering of rocks, and tree roots are likely to be one of their answers. However, unlike the answer to “what is a cause,” the answer to “HOW do roots cause erosion” was not known. That is, until recently.

Dr. Bonneville and colleagues from Leeds University in Great Britain set out to answer this question. They investigated the erosion of rocks by plants on a nanoscale. Remember, that the prefix “nano” means one billionth of something, so the events and processes they investigated were not something that could be seen by the human eye or even a compound microscope. When analyzing their results, they used an electron microscope to view changes in rocks. What they found was that fungi on the roots of trees caused the physical and chemical breakdown of rocks, something long hypothesized, but never shown.

So, what exactly happens on the nanoscale when plant roots invade a rock? First, it’s important to remember that almost all plants, including trees, have fungi called mycorrhiza that grow on their roots. Dr. Bonneville and his colleagues created an experiment that modeled this. They obtained a pine tree seedling with mycorrhiza on its roots and placed it in a transparent pot containing nutrient-poor soil and a specific kind of mineral called biotite. Biotite is a mineral commonly found in rock and it is rich in potassium, iron and magnesium. No other fungi or microorganisms were in the soil or on the roots. Then the researchers waited three months. After three months they examined the biotite along a single root using an electron microscope. They found that the biotite at the tip was bent as a result of mechanical pressure from the fungi, a pressure that can reach as high as the pressure in a car tire. This pressure if you think about it, is pretty amazing since the mycorrhiza are microscopic organisms. After performing other tests, they found that the fungi had also chemically altered the biotite, removing its potassium and causing the break-down of the biotite into other soil minerals, vermiculite and ferrihydrate.

Their results suggest that at the nanoscale, tree and plants roots cause erosion of rock through both physical and chemical means. The fungi bend and weaken the crystal structure of rock first and then chemically alter its composition by removing potassium. In addition, the wedging and bending of the biotite’s crystal structure allows other iron compounds in the rock to chemically react with oxygen in the air. In the end, the potassium and other released nutrients are passed onto the roots of the trees or plants and the area around the root that was once rock becomes soil.

For LabLearner students these experiments bridge some of the concepts they learn in the Weathering and Erosion CELL and the Classification GAP Unit. In the Weathering and Erosion CELL, students investigate differences between physical and chemical weathering and erosion of rocks. In doing so, they learn that in nature both types of weathering and erosion occur and that physical weathering and erosion aids chemical weathering and erosion by first breaking down rock into smaller pieces that can be more systemically “attacked” by chemicals. In the Classification GAP Unit, students learn about various multi-cellular organisms, one of which is fungi. They also learn about some properties that are characteristic of fungi, including a symbiotic relationship with other organisms such as plants, and the secretion of enzymes that breakdown matter in their environment.

In the past, students may not have linked the concepts described above together. This latest research, however, illustrates once again that LabLearner students will benefit from exploring all areas of science and hopefully finding new and intriguing connections between them.

Dr. Christine Jurasinski                             LabLearner Staff Scientist

For third, fourth and eighth grade students in the LabLearner Program, learning about charges and circuits means learning about electricity. From electrical power plants to microchips, electricity has been one of the mainstays of our world’s technology and a key component in telecommunication devices. A recent discovery from scientists at Yale University, however, may pave the way for that to change.

Dr. Hong Tang and a team of researchers at Yale University work in a field called nanophotonics. To understand what that means let’s take the word “nanophotonics” apart. Photonics describes technology that uses light to transfer information. Fiber optics, optical scanners, lasers, and satellite imaging are all examples of photonic technologies. What makes ‘nanophotonics” different is that the technological research or applications occur on a much, much smaller scale. “Nano” literally means one billionth of something. For Dr. Tang and his team, their research in nanophotonics deals with silicon microchips. Recently, these scientists made a discovery that may allow silicon microchips and other nanodevices to work using light rather than electricity.

So, why is this exciting news and what may this mean about what LabLearner students learn about electricity?

What’s exciting is that Dr. Tang and his associates discovered a repulsive and attractive force of light. Since about 2005 many scientists have theorized that small beams of light could attract or repel each other when placed very close together- such as on a silicon chip. This attraction or repulsive force was proposed to be similar to the electromagnetic forces that occur between positive and negative charges, a phenomenon that LabLearner students investigate in the Exploring Electricity CELL in third grade and the Electricity and Magnetism CELL in eighth grade.

Now, however, that phenomenon is no longer theory. The researchers at Yale University showed that they can produce a beam of light on a silicon microchip that has a repulsive force and a beam of light that has an attractive force. What’s more they showed that that both beams of light could physically MOVE very small switches called nanoswitches in circuits on the microchip, turning circuits in the microchip on and off.

Does this mean that soon we’ll be able to take flashlights and move objects around? An interesting thought, but no. These newly discovered optical forces are very strong on the nanoscale, but too weak on much larger scales. For example, even focused light such as that found in two laser pointers can’t cause the laser pointers to attract or repel each other.

However, when you think about the type of energy and scale that is involved in something like fiber optic communications, this discovery could be potentially revolutionary. The reason is that many technologies such as fiber-optic communications work by converting light signals into electrical signals and then converting the electrical signals back to light signals, all on a micro and nanoscale. This new discovery suggests that light alone could be used to manipulate signals and move switches. This would make telecommunication and other nanodevices like microchips much, much faster and cheaper.

And what about those LabLearner students? Will this leap in technology make learning about electricity a thing of the past? As with all new technology and with all areas of science, understanding basic principles provides a solid foundation on which to build. Although the repulsive and attractive forces of light are a new and complex discovery, the basic principles of attraction and repulsion remain. These principles are the basis of students’ experiments about static electricity in the third grade CELL Exploring Electricity. In this CELL, students explore what is meant by positive and negative charges, and attraction and repulsion. Through their experiments they see and FEEL a very tangible example of how difference in charges can create at attractive or repulsive force. It is this type of knowledge that sets the stage for understanding what is meant by an attractive or repulsive force of light. As students move into fourth grade they explore energy transformations in the Forms of Energy CELL. Understanding that energy is neither created or destroyed but only changes forms can help students understand the energy transformations of technologies like fiber-optics. Finally as students move into eighth grade and the Electricity and Magnetism CELL, they begin to combine mathematical formulas with tangible evidence of electric and magnetic attractive and repulsive forces. The basic foundation about charges, attraction, repulsion and forces that they build through the LabLearner Program may just lead them to be the designers that harness the attraction and repulsive forces of light in the decades to come.

How Do Sunspots Affect Our Weather?

Dr. Christine Jurasinski                       LabLearner Staff Scientist

Whether you turn on the TV, hit the Internet or open the paper, the changes in the weather during this time of year are making headlines. Hurricanes and tropical storms are developing in the Atlantic and Pacific and the continued dry weather in the Southwest has fueled the wildfires in California.

Now, our ability to predict and prepare for the ramifications of weather events may have just increased. New research by an international group of scientists at the National Center for Atmospheric Research has suggested connections between the 11-year solar cycle, the stratosphere and the tropical Pacific Ocean that may be responsible for changes in global weather patterns. These connections may help scientists better predict the timing and intensity of climatic events such as the Indian monsoon and rainfall in the tropical Pacific.

Scientists have known for centuries that the energy released from the Sun each year varies little. However, over an 11-year period, there is a cyclical difference in the sunspots that erupt from the Sun. As sunspots erupt there is a release of charged particles that alters the magnetic activity and radiation that reaches the Earth. During the 11-year cycle, there is a period at which sunspot activity is at its maximum and a period at which it is at its minimum. This new research suggests a correlation between the maximum period of the 11-year cycle and changes in the equatorial Pacific weather.

The atmosphere of the Earth can be divided into different sections. The troposphere is the section closest to the surface of the Earth. Just above it lies the stratosphere. The stratosphere is heated directly by radiation from the Sun. During the period at which sunspot activity is at its maximum, increases in radiation from sunspots increases the warming of the stratosphere, particularly along the equator where the Sun’s ray are the most direct and intense, something LabLearner students learn in the Solar System and Space CELLs. The result is a more pronounced heating of air around the air in the stratosphere around the equator than “normal.” This change results in changes in stratospheric winds, which can change tropical precipitation, dumping rain in the western equatorial Pacific region. This part of the effect is what researchers are calling the “top down” effect of the sunspots.

For older LabLearner students, another portion of the 11-year solar cycle, the “bottom up” effect, is directly related to concepts they will learn in the Atmosphere CELL and the Clouds and Storms GAP Unit.

As LabLearner students learn in the Atmosphere CELL, radiation from the Sun heats the Earth and its atmosphere. As air is heated, its volume increases. This relationship, called Charles’ Law is one of the key principles students learn in the Atmosphere CELL. This change in volume with heating results in a change in the density of air. The warmer air becomes less dense and rises in the atmosphere. Ultimately it will cool, become less dense and sink back towards the Earth’s surface. This cycle of rising and falling creates global convection currents that affect the climates of different areas on Earth. The rising and falling of different densities of air is also responsible for formation of clouds, precipitation, fronts, hurricanes and tornadoes.

So, how does this recent research fit in with what LabLearner students are discovering through their investigations? The second portion of the new research deals with what is called the “bottom up” effect. The “bottom up” effect is an example of Charles’ Law and the changes that the differences in air density can produce. The increased energy during sunspot maximum also causes a slight warming of the ocean surface waters along the equatorial Pacific (“bottom up” effect). This causes an increase in less dense warm air that rises from the equator and ultimately in more evaporation of water. As a result, there is an increase in the water vapor that is transported by the trade winds to the western tropical Pacific, increasing the amount of precipitation in this region. In addition, the eastern Pacific sees less rain and cooler temperatures because of this movement of air and moisture.

Ultimately, the western tropical Pacific region experiences an increase in heat and rainfall and the eastern tropical Pacific a cooler and dryer year because of both the “top down” effect from stratospheric heating and the “bottom up” effect of ocean water and tropospheric warming. This latest research reinforces what scientists have known and what LabLearner students should discover: that understanding the effects of the Sun’s energy on the Earth is a key to understanding our weather.

Music and Reading

How Can Music Training Help Students Read?

Dr. Christine Jurasinski             LabLearner Staff Scientist

First grade students in LabLearner schools across the country have or are about to embark on a discovery and study of their five senses. In the Our Senses CELL students learn about the senses of sight, hearing, touch, smell and taste. As they explore each of these senses, they learn that each sense not only uses a sense organ such as the eyes, but also uses the brain to interpret and process information. But, exactly what type of cognitive processing occurs in our five senses? Recently, researchers have completed studies that shed some light on our sense of hearing and the interesting relationship between hearing, reading and music.

Through their experiments, scientists at Northwestern University have found that musicians are better at identifying spoken words when mixed with background noise than people who do not have musical training. Not surprising? For many people, this finding may seem intuitive. Through their training musicians learn to recognize pitch, timing and other spectral elements of sound. Thus, it would seem logical that these people may possess greater precision within their auditory and nervous systems for interpreting sound.

However, this new study presents information that the processes that occur when transcribing and encoding sound are enhanced in musicians as compared to “non-musicians” and that these same processes are deficient in children with dyslexia. Thus, there appears to be a relationship between sound encoding in the brain and linguistic abilities suggesting that poor or struggling readers may benefit from musical training.

Just how would musical training produce changes? One theory is that there are certain consonants that are often misinterpreted by the brain especially when heard in a noisy environment. Misinterpretation of consonants can make a difference in how words are read. Musical training may help by enhancing the ability of the brain to hear certain acoustic features of speech such as these consonants. A second theory is that musical training is linked to better working memory and improved auditory memory. Still another is that musical training includes a focus on timing which is related to temporal processing or the time to process auditory stimuli. Various aspects of temporal processing are affected in dyslexia and other auditory disorders. By emphasizing timing, musical training may help to alter or enhance temporal processing.

Research in this area will continue to provide answers that can help not only struggling readers, but the population in general. Maybe a song a day will be just what the doctor orders.