In Inquiry into Biology, the opening story for chapter 4 describes why biting into a chili pepper produces a burning sensation in your mouth. This is because chili peppers contain a compound called capsaicin that activates the pain receptors in your mouth, which is interpreted by the brain as the “burn.” And as every chili-head can tell you, not all peppers are equal. While many may think that the chili peppers are producing capsaicin for our benefit, there is a much more interesting story behind this compound.

Several years ago, in one of my introductory biology classes, I mentioned that one of the most promising ways to fight diseases, such as malaria, might be to genetically engineer a better mosquito. As you may expect, the looks from the around the classroom were fairly consistent - their usually slightly-off center instructor had finally stepped over the edge. After all, shouldn't we be getting rid of mosquitos, not making them better?

While humans may be fairly adept at driving species into extinction, we seem to have a problem when it comes to mosquitoes. For diseases such as dengue  and yellow fever, the mosquito we are dealing with, Aedes aegypti (shown below), has proven to be a formidable foe. The species has a very short generation time (10-14 days), and can reproduce in environments with very small amounts of water (planters and old tires are frequently used). In addition, they have exhibited the ability to very quickly evolve resistance to many forms of insecticides. Despite modern efforts to control this species, it is not only surviving, but doing well.


One of the diseases that this mosquito is involved with is dengue fever. This is a multistage infection. The disease starts off with a high fever, pain behind the eyes, and muscle pain. But the real damage starts to occur about 24-48 hours after the fever breaks, when the capillaries of the body can become leaky, resulting in dengue hemorrhagic fever (DHF) , which may result in circulatory system failure and death. Like many hemorrhagic fevers, there are no medications or treatments.



Despite the fact that dengue fever is caused by a virus, there are no vaccinations, and preventive mechanisms focus on avoiding mosquito bites. But since dengue occurs in the tropical regions of the globe, over 40% of the world's population is exposed to the mosquito, and there are believed to be over 100 million new cases per year. Avoidance of mosquito bites for densely populated areas within the range of Aedes mosquitoes is becoming increasingly difficult.

So how does one control the spread of a disease that utilizes a host species that is resilient to most of our efforts? The answer might be not to kill the mosquito, but rather to make it an inhospitable host for the virus that causes dengue. And the secret to this is Wolbachia, a species of bacteria that is a common parasite of many insect species. Wolbachia has been studied extensively in species of insects such as Drosophila (the fruit fly) and it is well-recognized as having the ability to moves rapidly through populations of insects.

Researchers have shown that the dengue virus does not reproduce well within a Wolbachia-infected mosquito. Since dengue fever can only be passed on using the mosquito as an intermediate (there is no person-to-person transmission), if the number of dengue-carrying mosquitoes can be reduced over an extended period of time, it may be possible to break the cycle of infection. This opens up the possibility of actually releasing millions of Wolbachia-infected Aedes mosquitoes into a given area, with the hopes of breaking the dengue-virus life cycle. Trials are currently underway, and if successful, may open up a new chapter in how humans regulate the spread of some of the most deadly diseases on the planet.

Additional Resources

• Additional information on how Wolbachia may reduce spread of dengue fever
• CDC site on dengue fever, including an interactive map of dengue fever locations
  

Communicating with your online students can be challenging. While most course management systems (CMSs or LMSs) have discussion boards and email capability, the reality is that somehow as an instructor you need to drive them onto the site to get the course information -for as we all know, students will not "surf" course pages.

One solution is Twitter. In my Human Genetics class, which has been taught as both a hybrid and online course for the past five years, I use a Twitter site to inform the students of upcoming events such as assignments, quizzes, and tests.


Some best practices for using Twitter for this audience:

Provide specific instructions on how to set up a Twitter account

While the 18-25 age group may be the social network generation -the reality is that most of them do not have a Twitter account, nor even understand why they might want one. At the start of each semester I post a pre-course checklist that contains instructions on how to set up a Twitter account and subscribe to the course Twitter site. It is important that this checklist contain screenshots of exactly how to setup their accounts. Increasingly, I am abandoning the checklist aspect of the course in favor of video tutorials on how to set up and use an account. 

One thing that you want to inform your students of is the fact that they do not need to have your course tweets sent to their cell phones - especially of they do not have unlimited text messaging on their cell phones. Instead, I inform the students that they can set up programs such as Tweetdeck that allow them to subscribe, and filter, a variety of Twitter sources.

One additional note on Tweetdeck - it provides an easy way for an instructor to not only manage multiple Twitter accounts, but to also post information rapidly to their students. If you are going to use Twitter in your classes, I highly recommend the Tweetdeck program (and iPad app as well).

Limit the number of tweets and tell your students how to follow them

The last thing that your students want to know is what you are up to this weekend, or your political views on a certain candidate. Therefore, you need to limit the number of tweets that you send each day - and make them specific for the course.

For my course, I send out one tweet per day (usually Monday-Friday) informing the students on what is coming up over the next few days, due dates for assignments, etc. Occasionally I include tweets about current event topics that are related to the current course content - but it is important that you make it relevant to the current material, otherwise you are simply bombarding them with tweets - and that is not the goal of the course Twitter site.

Set up a second Twitter site for your other posts

On the course checklist I inform my students of a second Twitter site, RicochetScience, that they can subscribe to for information on a variety of sources. Most students actually pursue this option, but since it is not required, they do not feel obligated to read every link or tweet.


While there are many ways of communicating with your students using social media - the use of a Twitter account is by far one of the easiest for both the instructor and the student.

Additional Links

• ASU Genetics Twitter Site - for the Human Genetics course at Appalachian State
• Ricochet Science Twitter site science- weekly updates on news for the introductory science classroom
• Tweetdeck website
  

First of all, what is LearnSmart? Basically - LearnSmart is an adaptive learning platform that provides a student-centered assessments of learning. In other words - the program responds to what the student does and does not know, and designs a custom learning path to allow the student to obtain certain learning objectives. 

While I have given numerous workshops on the benefits of LearnSmart, I have also discovered that many instructors do not yet know how to effectively assign LearnSmart for their students. They make the mistake of assigning too much material, or weighing it too heavily in their final grades. The instructors at my institution have requested that I outline a series of steps to get them into the program. Below, I have provided a brief overview that will allow an instructor to quickly and easily engage their students in the LearnSmart platform. Please note that this is just one set of guidelines on how to use the program - after you become familiar with the system, you should feel free to experiment and develop your own, course-specific best practices.

Step 1:  Assigning Content

In my classes I use LearnSmart to get my students prepared for the lecture, be it virtual or traditional. Therefore, the initial assignments usually focus on the core terminology and concepts of the chapter. I have found that if I can get the students to understand key terms and concepts before class, I can spend more time developing the more difficult concepts and applications.

Most of the time - the core concepts are located in the first few major headings of the chapter (10.1, 10.2, etc). Therefore, for the pre-class assignment, I only assign those sections of the text (Step 4 will show you how to integrate the entire chapter).

The other key item in generating an assignment is to give the students time to complete the work. The goal is not to overwhelm them in scientific terminology, but to build a foundation. Therefore, using the slider bar I usually set the assignment for around 20-30 minutes average worth of work. 

As you move the slider bar from right to left, you are increasing the focus on the core materials, and reducing more of the application-related content.

Step 2:  Due Dates

For due dates - when possible, I assign LearnSmart material 5 days prior to the lecture. This allows the student, who increasingly has a busy schedule of classes, work, and family, ample time to complete the assignment. One of the nice aspects of LearnSmart is the fact that you do not need to complete the entire assignment at one time - so 20-30 minutes of work can easily be spread over a few days if needed.

I also always assign the same time each day for the assignments to be due. I happen to choose 1155pm (never choose 12 pm, too easily confused with 12 am), but other instructors choose the start of class for their traditional or hybrid courses. Be consistent and you will greatly reduce the number of emails from your students!

Step 3:  Assigning Points

My goal for using LearnSmart is to develop an understanding of how the course material - a foundation on which I can build more difficult concepts. Therefore, I award points based on 100% completion. If you complete 100% of the LearnSmart assignment - you get 10 points towards the module grade (usually 100 or 200 points total in my classes). The eliminates the focus on right/wrong, and greatly reduces the student appeals of specific cards. 

Step 4:  Entering the Playground

Even though I do not assign all of the sections, I encourage the students to work on the complete chapter in LearnSmart before their exams. Actually, most of my students request this feature.

To access the complete chapter, simply enter what I call the "playground" . On each Connect site, in the lower right is an icon similar to the one below. By clicking on this icon, the students enter the LearnSmart program for the entire book.

One note of caution - it is important that you inform your students that assignments need to be completed from the Assignment list, and not from within the playground, since no grades are recorded from within the playground.

In later postings, I will discuss how you can run reports using LearnSmart, and how these reports can transform your classrooms from an instructor-focused environment to a student-centered learning arena that utilizes both adaptive learning and adaptive-taching strategies.

If you are a user of LearnSmart, I also encourage you to enroll in The Connect Community, a site where you can find active discussions on adaptive learning, case studies on classroom effectiveness, and more importantly, a community of educators who are exploring new ways of interacting with students. 

Additional Resources

There is a paradox in ecology education. The fact is that most students are very interested in the diversity of life on the planet - that is why they take biology rather than chemistry or physics for their general education requirements. But, when most professors get to the biodiversity lectures, they run through an seemingly endless series of PowerPoint slides of different organisms. And to be honest with you.. PowerPoint slides are not all that interesting.

What are the general characteristics of a prokaryote shown below? Lack of a nucleus? Cell walls made of specialized sugars called peptidoglycans? Lack of membrane-bound organelles? All of the above?

What about none of the above? What if we found a prokaryote that lacked all of the items listed above, but was by all other characteristics, a prokaryote? What would that tell us about the evolution of the bacteria?

Many times in the classroom we are ask students to take an evolutionary "leap of faith". Since bacteria do not easily form fossils, then we may never really find the elusive link between the prokaryotes and eukaryotes. The evolution of the eukaryotes is a logical series of events, shown nicely by the endosymbiotic theory - but to be truthful, something tangible that we can point to in the classroom has been hard to come by. There has always been Giardia, the parasitic eukaryote (protistan) that lacks a mitochondria, but most evidence suggests that Giardia evolved from a eukaryote that possessed a mitochondria - so it is probably not our missing link.

However, scientists at the University of Queensland have identified a group of bacteria - called the planctomycetes, that are closer to a missing link than anything we have had in the past. 

Planctomycetes are an interesting group of bacteria. They possess a form of intercellular compartments that appear to have specialized metabolic functions. One of these, called an anammoxosome (breaks down ammonia) that appears to have a similar function to the eukaryotic mitochondria. The DNA of a planctomycetes is contained within a membrane-bound nucleoid region - not quite a nucleus, but it definitely represents an internal compartment for the genetic material. Also, most of the planctomycetes lack peptidoglycans (a sugar-amino acid combination) in their cell walls. The presence of peptidoglycans is a defining characteristic of bacteria in general, and is the target of many forms of antibiotics - the fact that the planctomycetes are lacking this compound suggests that they are not a common form of bacteria. In addition, planctomycetes tend to (but not always) reproduce by budding instead of binary fission. Yeasts, a one-celled eukaryote, reproduce by budding. (Looking for a comparison of a planctomycete with a common bacteria?- download our PowerPoint for use in the classroom)

As I have been traveling across campuses this spring I have had many requests for resources to integrate current event topics into the classroom. Most instructors do not have time to look  daily for level-appropriate resources, so the staff at RicochetScience have prepared several resources to help you quickly get the content you need.

One of these  is Delicious - an online bookmarking site that allows users to set up networks and share bookmarks.

A really nice tutorial for using Delicious in the classroom is available on YouTube

For those of you who are still looking for additional resources, you can also generate RSS feeds from the RicochetScience Twitter site or the MaderBiology twitter site. The RicochetScience Twitter contains daily updates on a number of topics associated with introductory biology, whereas the MaderBiology Twitter site contains areas specific for the Mader series of textbooks from McGraw-Hill. Both of these contain appropriate content for your course management systems.


Of course, you can always link directly to this blog using any of the links to the right.

Additional Links

• MaderBiology Twitter Site
• Ricochet Science Twitter Site
• RicochetScience Bookmarks on Delicious
  

While it is clear that plants evolved from a green algal ancestor some 470-500 MYA, the question has always been.. which one? We know that plants and the green algae share the same photosynthetic pigments (chlorophyll a and b), store their energy as starch, and contain the fiber cellulose in their cell walls. But that is a general description for many of the green algae. After all, there are lots of green algae, from the mobile Chlamydomonas to the multicellular Ulva. Saying that the ancestor of the plants was a green algae is like saying that your ancestors came from Europe, a nice general statement, but it really doesn't tell you much about who you are.


Spirogyra is no stranger to the introductory biology classroom. Since it is easy to culture and observe, it is a common specimen in freshman labs. Furthermore, as can be seen in the video below, it has a unique configuration of its cloroplasts that gives the organism its name.

Additional Links

• EarthSky article on Spirogyra and plant origins
• EOL page on Spirogyra
• BMC Evolutionary Biology paper "Origin of land plants: Do conjugating green algae hold the key?"