LabLearner

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

admin L2 Newsletter Articles

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.

admin Uncategorized

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.

admin L2 Newsletter Articles

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.

admin L2 Newsletter Articles

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.

admin L2 Newsletter Articles

St. Agnes school in West Chester, PA. A short interview with Meghan Setting, a student teacher from Immaculata College.

admin TPD (Job Embedded)

St. Agnes school in West Chester, PA. Students have just tasted a freshly sliced lemon. They have to decide if the taste is sweet, sour, or salty. Check out their faces!

admin TPD (Job Embedded)

St. Agnes school in West Chester, PA. Student teacher Meghan Setting from nearby Immaculata College teaches a first grade lab on Our Senses. This Investigation deals with the sense of taste.

admin TPD (Job Embedded)

Colleen Hannigan is a certified teacher who has been assigned to oversee the LabLearner lab at Our Lady of Calvary in Philadelphia, PA. The school is one of 27 others in the Archdiocese of Philadelphia who use the LabLearner program for their entire PreK-8 science curriculum.

admin TPD (Summer Sessions) Philadelphia, summer, TPD

Third year LabLearner teacher, Mrs. Marko, discusses her pedagogical methods for constantly relating LabLearner laboratory experiences to the appropriate scientific concepts.

admin TPD (Job Embedded)