Two hypotheses were presented in the previous post about chipped marbles. The first was that the incidence of marble chipping was independent of color, while the second was that one particular color of marble (e.g., only blue marbles) chips.

If chipping is random throughout all colors, what is statistically significant is the RATE of chipping, or number of marbles chipped per set of 100. If, however, only the blue marbles are chipped, that fact is also statistically significant, because now being blue seems related to being chipped. So, there could be two hypotheses drawn, depending on which scenario is found.

In scenario #1, we might then go on to look into what process in marble making might be responsible for chipping the marbles.

–For instance, could chipping be due to the molding process? Could it due to how quickly or slowly the marble mixture is cooled in the molds? Maybe the temperature difference between the marble mixture and the mold causes the marble to be more brittle, and thus more susceptible to chipping? Or maybe it happens as the top mold is clamped to the bottom mold?

–Could chipping be due to the polishing process? Is the arm that pinches and holds the marble chipping the marble, or is the arm agitated at too quickly such that polishing becomes abrasive? Is the buffing material too rough?

–Could the bagging process be chipping the marbles? Do the marbles tumble out too fast so as to bash against the shoot too harshly? Is the drop into the bag too great a distance?

In each of these processes, can you think of other investigations we'd need to do to follow up?

Now that we've touched on vetting sources, let's talk about another method of scientific analysis, and that is, statistics. Let's face it, the subject of statistics is NOT something we want to read about in our spare time. But it's an integral part of interpreting data gathered by experimentation. In general, statistics tells us about the validity of a data set, and ultimately reflects upon the design of the study and the hypothesis itself.

By way of example, let's turn to marbles. If chips on marbles truly occur randomly, there's no way to conclude anything specific about a certain marble that has a chip, except that marbles get chipped. Now, say that the 100 marbles in the pic represent 100 people. If you know that diseases like the flu, for example, infects birds, pigs, and people, but that only people can die from infection, then you can reasonably say that the flu is only deadly to people. But scientists don't just stop there! They will test that hypothesis further by gathering data from testing populations of pigs and birds that are infected with the flu. If neither pigs nor birds die, this is further evidence that supports their hypothesis, "Only people are susceptible to dying from the flu."

Now let's go back to the marbles as being marbles. If we find that every chipped marble is also one specific color, what do you think we can deduce from that?

Over and over I've said, "Scrutinize your sources" when searching the internet for science/medical information. But how does one truly determine whether or not the site is credible? If you can discern what true motivation lies behind the site, this will give you much insight as to whether or not the site is a credible one.

This flowchart demonstrates the process MY brain goes through when I search the internet. When it comes to finding credible information about diseases/ailments in particular, what determines credibility focuses on several main issues: WHO is authoring the site? WHAT are their credentials/sources/citations for their claims? Is there an ULTERIOR MOTIVE, for instance, a spine clinic/chiropractor trying to convince you to become a patient, or purchase their very expensive nerve stimulation gizmo? What kind of FEEDBACK does this site receive? Has the information been directly copied from another site (I've encountered this often!)? Was that info. then properly cited?

Medical topics are especially difficult because without the basic foundation of biology, chemistry, physiology, or biochemistry, it is very easy to NOT understand holistically how our body is impacted when trying a new treatment. But it doesn't mean you can't logically deduce the credibility of the site, you just have to be prepared to accept another viewpoint if it's well-supported. A number of websites tout treatments based only on anecdotes and testimony. There's a good reason why we have regulations on the medical industry/research, because un-tested treatments can be HARMFUL. Blogs, websites, etc, are NOT always written by credible individuals, nor are their claims backed up by anything other than "It works for me!" I'm not saying it didn't work for that person, but it is simply not enough to make whatever it is a treatment for all, and what's more, side effects can have worse outcomes than the treatments itself. Starting with an opposite hypothesis might make you more critical of what you are reading.

In case you are wondering, I do have my biases too. I'll trust anything that comes out of Johns Hopkins, the Mayo Clinic, the CDC, NIH, FDA, R1-research universities, or any reputable hospital (e.g., MD Anderson or Memorial Sloan-Kettering Cancer Center, for cancer questions). AND, I shamelessly use Wiki to get those all-important key words to help refine my search!

Here is where we get to bust another myth, just as we did for DEET. Acrylamide, shown in "shorthand" in this pic (no intermediates), is produced by the reaction between the sugar glucose and the amino acid Asparagine under high heat. It is the focus of investigation behind the act of charring, grilling or roasting techniques in causing cancer.

According to the American Cancer Society, while acrylamide isn’t something we should go out and gobble up by the bowl, we should be aware that in fact a link between acrylamide and cancer has NOT yet been established.

Fried foods like french fries (sorry), potato chips (again, sorry) and coffee (SO sorry) are among the foods that have the most acrylamide. Grilling/charring of meats produce acrylamide, but many foods also naturally contain acrylamide. Foods lower in acrylamide are your lean meats, like poultry and fish, and eggs, beans, nuts, fruits, veggies, whole grains, and fat-free or low-fat dairy.

The best strategy we have is to eat as much non-processed stuff as possible. Now, I’m the first to complain about having to meal plan every day of the week, and the first to give myself a break from this routine with a frozen, ergo processed, meal. Be wary of any company or individual claiming an absolute, and when doing your own research BE SKEPTICAL about what you read and your sources. When in doubt, moderate!

As a last-gasp ode to summer, this topic–lead in beautifully from our mosquito talks–will be about grilling! We are going to unpack a few things about grilling, starting with how that smoky, charred, delicious flavor and smell are created. And we really can’t talk about that without our beloved chemistry.

Since we discussed how mosquitoes use odor molecules to identify us as tasty morsels, we can expand on this with looking at a chemical reaction that is generally responsible for producing the odor molecules produced in grilling meat: the Maillard Reaction. There are additional products produced by this reaction: flavor, and the physical “browning” on the surface of the protein, which occurs when sugars react with proteins and amino acids as sufficient heat is applied.

To analyze this reaction a little more closely, in the first line you’ll see that there are 2 molecules, a sugar and a protein. In the 2nd line, now these two molecules are combined into one, and that atoms from each are lost, two hydrogen molecules and an oxygen (released as water). In the 2nd line, when a carbon dioxide is released, a double bond is formed in its place. Chemistry is very elegant because whatever is on the left of the arrow has to be equivalent to what is on the right.

Now comes to the grilling CONTROVERSY: we have heard about how charring/grilling/smoking can cause cancer. What in this process could be responsible for this? Hint, it's a possible product found in the 3rd line....

Let’s wrap up this topic with discussing some alternatives to DEET. These compounds have shown some mosquito-repelling characteristics, and are mainly the extracted oils from certain fragrant plants. To show you what the chemical formulas for these oils look like, I’ve drawn a few of them here. I think you’ll see that there’s a certain resemblance in chemical structure to DEET? If you remember back to the days where I talked about how mosquitoes likely identify odors, you’ll recall that it takes two proteins with specific shapes to form the receptor that captures the odor molecule. So, if another molecule can fit into these same receptors used to identify something tasty, but actually doesn't trigger anything identifiable because it's a different chemical, then guess who gets "confused"  and can't find dinner after all?

I know that fun is relevant, but to me, it's fun to understand how things work and to dispel myths in the process!

So, how does DEET work?
A) Like an invisibility cloak, masking your smell to the mosquito.
B) Like a stink bug, making the wearer disgusting to smell.
C) Like a common cold, whereby the mosquito can’t smell properly.

And the answer is....D!
We don’t quite know, but all three of these answers seem to have some basis in the working theory, and is backed up by the scant research that has been done on the subject. What has been determined is that DEET interferes with the mechanism by which the mosquito uses to identify odors. It may “scramble” our emitted scent, in a way cloaking it, or, it may dull the mosquito's olfactory sensors, rendering it unable to detect the scents it seeks. So, in a way this too is a method of cloaking. DEET may also cloak by instead masking us with another, let’s say less desirable, smell. Research has yet to answer this part of the question.

Next obvious question is, is DEET harmful?
Believe it or not, according to the CDC’s Agency for Toxic Substances and Disease Registry, the answer is a resounding NO.
(http://www.atsdr.cdc.gov/consultations/deet/relevance.html). Unless you drink it.

But if you follow the application instructions you are good to go. Yee HAW.

A very important survival skill for the mosquito is to be able to seek out its prey (AKA, me). We humans are running about all over the place, and some of us spend way more time out of doors than others. So, I always wondered why mosquitoes seemed to seek out some (ME) more zestily than others. Some say it’s blood type, others say it’s wearing clothes that stand out against a background. Some say it’s eating too many bananas, others say it’s how much carbon dioxide you exhale....

None of these theories have been proven conclusively. For example, since mosquitoes do detect human presence by carbon dioxide, then beer drinkers should be more readily targeted. But we all know that this isn’t the way it works.

What we do know is that mosquitoes use their antennae to sniff the air. Within the antennae are odor receptors, made of two protein components: Orco, and another chosen from a variety of proteins to which Orco can couple. When they couple, together they bind a very specific odor molecule that then signals a neuron, which then tells the mosquito who/what is nearby.
Here’s the real reason I bring this up. I can't help the odor molecules I put out, that's something genetic and therefore cannot be altered. So, how does a chemical like DEET save me from these tiny little terrors? Well, the “answer” begins here with the partnered Orco receptor, and will “end” in the next post!