Horton Hears a Who – Hidden Communities in Leaves

Maybe you remember reading the classic Dr. Seuss tale as a child, Horton Hears a Who! Or you may have also seen the 2008 movie adaptation on TV or at some recent family vacation? For those who haven’t, or whose memory might be a little fuzzy, Horton the elephant discovers, and becomes the sole champion of, an entire microscopic community living on a speck of dust: the fabled city of Whoville.

A cartoon elephant holds a tiny flower close to his ear using his trunk. On this tiny flower is an even tinier speck of dust.
An image of Horton the elephant listening to the sounds of the Whos from Whoville, who live on a speck of dust. Taken from the popular children’s novel “Horton Hears a Who”, originally written by Dr. Seuss.

A similar champion for the hidden microscopic communities of our world can be found here at IU–a research scientist by the name of Natalie Christian from Dr. Keith Clay’s lab in the biology department. However, instead of a speck of dust, Natalie’s microscopic communities form inside of plant leaves, and instead of the Whos of Whoville, the inhabitants of these leaf communities are tiny fungi called endophytes, for which the Latin translation literally means “inside plant.” One of Natalie’s central research goals is to better understand the importance of these microscopic communities for the health and well-being of their host plants. (more…)

Roots of the Langlands Program

The Langlands Program has been progressing for a long time, with many of the big names in mathematics involved. Dr. Matthias Strauch, an Associate Professor in the Indiana University Mathematics Department, and I discussed some of the history of the field.

The story begins with linear equations, although the modern scope of research has flown far beyond. These are equations containing no squares or higher powers, no roots, no dividing by anything weird. (Dividing by numbers is fine, but not dividing by a variable.) These equations might be familiar, depending on how long it’s been since you took algebra.

Believe it or not, we can solve almost all of these. Only one thing can go wrong, and that is if, after grouping like terms, the coefficient on the x term is 0. Then solutions might not even exist. But when the coefficient is not zero, we get a solution. In fact, it has a formula.

If ax=b,then:

x = \frac{b}{a}

 

Say we have a quadratic equation like ax^2+bx+c=0 , where a is nonzero. Now we have a more complicated formula:

x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}

 

But what if x^3 gets involved? Is there a formula then? (more…)

Ordering Disordered Materials

Pictures of snowflakes, a flower, a beehive, and table salt are shown.
Examples of order and symmetry: snowflakes (top left) [2], flower (top right) [3], beehive (bottom left) [4], and table salt (bottom right).
When we look around the world, we see order and symmetry. It’s evident in snowflakes, flowers, and beehives, just to name a few. Going beyond what the plain eye can see, we also know that several chemical structures consist of ordered atoms. For example, think of sodium chloride (more plainly known as table salt). Its patterned structure consists of alternating atoms of sodium and chlorine. Nature seems to have a good handle on producing materials which are ordered and symmetric, but as humans, how do we control the order in the materials we make? (more…)

Makerspaces and their growing role in STEM education

As a young child, years before the first Harry Potter book was published, I sat at my mother’s kitchen table mixing together anything I could find into a tall glass and calling it a potion. Now, this was just pure imagination and I’m sure that none of my concoctions were palatable, possibly even so bad that I’ve blocked out having tried them, but why did I even partake in this activity? Why did I also make all sorts of rather insane looking robots out of empty tins leftover from dog food, popcorn, or cookies? Well, this may just be simple childhood creativity (before the internet came into existence), but it may also serve as a clue as to why some people choose to pursue a STEM (Science, Technology, Engineering, and Math) career, or even just possess a strong interest in STEM, over other options. (more…)

Deuterium: Heavy Water, Tiny Probe

My grandfather was a big fan of the old sitcom Hogan’s Heroes, and to some extent, I’ve inherited his taste in comedy.  The episode which sticks out in my mind the most, centers around a heavily guarded barrel of water.  Numerous rumors circulate about why the barrel of water is so important, including one that the water is from the Fountain of Youth, but eventually it is revealed that the barrel simply contains “heavy” water.  Prior to my days as a student of chemistry,  this begged the question: what makes the water  so “heavy”?

You may be aware that a molecule of water consists of three atoms: two hydrogen atoms and one oxygen atom.  Water becomes “heavy” when the hydrogen atoms in water are substituted with a rare isotope of hydrogen. In case you’re not familiar with isotopes, you can think of isotopes as being the same basic building blocks of a molecule, only with a tiny bit of extra mass. This brings me to our main topic of discussion: deuterium.

A hydrogen atom, represented by a white sphere, is turned into a deuterium atom, represented by a green sphere, by the addition of a neutron, represented by a lowercase letter "n".
Addition of one neutron (n) to an atom of hydrogen (H) produces deuterium (D).

Both deuterium (D) and hydrogen (H) consist of one electron and one proton, but deuterium also has a neutron, which is what provides the extra mass in heavy water.  More succinctly, it can be said that deuterium is an isotope of hydrogen.  This subtle subatomic difference is all that distinguishes heavy water (D2O) from regular water (H2O), but the unique properties of D2O permit a myriad of applications in chemistry and physics.   (more…)

Earth Day 2017: Onwards and Upwards

“Unless someone like you cares a whole awful lot,
 nothing is going to get better. It’s not.”
Dr. Seuss, The Lorax

Less than fifty years ago on April 22, 1970, the modern day environmental movement was born and the first Earth Day was celebrated. Rachel Carson, scientist and writer, is credited with raising environmental awareness with the publication of her book, Silent Spring, in 1962. That publication, the political climate of the time, and a series of human-caused environmental disasters led twenty million people to come together and rally for the protection of the environment. On April 22, 2017 it is estimated that over 200 million people worldwide will follow suit and celebrate Earth Day. (more…)

Earth Day 2017: Reclaiming Climate Science

When scientists communicate with the public about politics, they often frame the issue as “science vs. politics.”  For instance, some scientists champion speaking truth to power, while others suggest that they stay out of the political fray altogether.  Both arguments assume that science and politics are independent and mutually exclusive.  Furthermore, they presuppose that science could and should remain politically neutral.  I’d like to discuss why this framing is problematic and how we might instead understand the political role of science.  Since Earth Day is just around the corner, let’s focus on climate science in the public discourse.

This same science-vs.-politics framing has arisen in the discussion of the recent actions of the Trump administration.  Many scientists and science supporters consider the White House to have an “anti-science agenda,” especially regarding environmental science and climate change.  This agenda included a temporary suspension of all Environmental Protection Agency grants, removal of the White House’s climate change webpage, and restriction of public communications for agencies such as the National Park Service.  In response, many scientists condemned the White House’s actions as politics interfering with sound science.  Following the Women’s March on Washington, they focused their energy toward a public demonstration, now officially “the March for Science,” which is planned for Earth Day (April 22) 2017.

Science activists wearing white lab coats hold signs such as “Scientists serving the common good,” “Stand up for science,” and “Scientists speaking truth to power.” They are gathered at a rally in Boston to “Stand Up for Science.” Many of the rally participants were also attendees at the AAAS annual conference during the same afternoon.
Coinciding with the annual meeting of the American Association for the Advancement of Science (AAAS), science activists rally to “Stand Up for Science” in Boston this past February. Marches and rallies for science are becoming an increasingly common form of political activism (Credit: Sarah McQuate at Sciencemag.org).

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Heritability: what it means and why it’s important

A cluster of points is plotted on a coordinate plane with x values randing from 155 to 180 and y values ranging from 160 to 180. A best-fit line is plotted against them
Simulated data for 1000 families representing heritability for some trait, say height in centimeters. Each point represents the mean of the offspring plotted against the mean of the parents. In this case, heritability, or the slope of the line, is 0.60.

In a previous post, I briefly discussed something called genetic correlation and how this might be important for the evolution of a trait. Now, I hope to further clarify that concept and add to that a discussion of a very important concept in evolutionary biology—heritability—and tie it back to my initial discussion of the evolution of pesticide resistance.

Consider your siblings or the siblings of a friend and you will likely observe that inheritance of a trait is not a binary distinction.  In other words, it is not always as simple as either having or not having a trait from a parent.  Chances are, neither you nor your siblings are exactly the same height as either of your parents, or their mean (or average). This is because height–and virtually every other quantitative trait, or one that is variable along some continuum—has an associated heritability (or h2). As an aside, the notation of this is a bit confusing; we’re not actually squaring anything, but this notational weirdness is an accident of history. At any rate, the most straightforward, but perhaps least intuitive way of thinking about heritability is that it is the slope of the best-fit linear regression of offspring trait means on parent trait means. If your parents’ mean height is x, and you and your siblings’ mean height is y, and you plot this as a point (x,y) on a coordinate plane along with those of many other families, heritability is the slope of the line that most closely follows this cluster of points. Incidentally, the technique of linear regression taught in introductory statistics was developed for just this purpose.

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How Do You Get Adolescents to Meditate?

a person sitting quietly in a meditation poseIn the health behavior field, we often focus on what health professionals should help young people avoid, such as risk behaviors, rather than positive health behaviors that we could help them acquire. So, when I decided to start working on my PhD, and I wanted to study health promoting behaviors, I knew I would be met with some resistance or challenges from the more well established health behavior researchers.  Fortunately, I ended up at Indiana University where this type of thinking is not only accepted, but encouraged within the Applied Health Science Department.

The adolescent period has traditionally been viewed as a time in life to ‘just survive’.  Remember the three As of adolescence- Acne, Awkward, and Apathetic.  However, due to advances in neuroscience, researchers are now singing a different tune when studying adolescents.  Traditionally, it was thought that a majority of the development that occurs in the brain happens during early childhood.  The neuroimaging studies from the last 10-15 years suggest otherwise (Giedd, 2008).  Around age 12, the brain goes through another massive restructuring as it eliminates connections between brain cells that aren’t used and strengthens those that are.   (more…)

Nanomaterials that Inhibit Bacterial Growth

Nanomaterials are fast becoming the materials of the future. Just this year three scientists were awarded the Nobel Prize in Chemistry for their work in understanding Molecular Machines. Each time period in human history has been defined by the materials that we are able to harness–the Stone Age, the Bronze Age, and now, the Nanomaterial Age? The better scientists are able to design, create, and manipulate nanoscale objects, the more advanced our technology will become.

But let’s back up a little. What is the nanoscale? You would be correct if you said really, really, really small, but let’s be more precise about it. A nanometer is 0.000000001 meters or, in scientific notation, 1 × 10-9 meters (move the decimal over 9 spaces). As you can see from the image below, you can’t see nanoscale objects with the naked eye, but they are still much bigger than individual molecules or x-rays. (more…)