More “Turkey Day” Trivia: Thanksgiving dinner

Turkey meat:  white vs. dark - What causes the color difference between white and dark turkey meat? The type of muscle fiber determines the color of the meat. Dark turkey meat has slow contraction muscle fibers. Slow contraction muscle fibers, sometimes called slow twitch muscle fibers, are used for extended muscle contraction in endurance activities and are supplied with lots of blood vessels, mitochondria, and myoglobin pigments, which give the red color to the meat. White turkey meat, on the other hand, has fast twitch muscle fibers for short bursts of strength and speed. Fast twitch fibers have a poorer blood supply, and fewer mitochondria and myoglobin, and tire quickly.

Cranberries – Of all fresh fruits, cranberries contain the most phenols, a type of disease-fighting antioxidant. Phenols and polyphenols are strong antioxidants and many scientists believe antioxidants protect the heart.

Yams vs. sweet potatoes - A yam is not the same thing as a sweet potato. Although yams and sweet potatoes are both angiosperms (flowering plants), they are not related botanically. Yams, native to Africa and Asia, are a monocot (a plant having one embryonic seed leaf) and are related to lilies and grasses. Sweet Potatoes are a dicot (a plant having two embryonic seed leaves) and are in the morning glory family. Yams are starchier and dryer than sweet potatoes.

Pumpkin pie - Most pumpkin fillings are really custard-type fillings with eggs acting as "gelling agents". They're able to do this because proteins in the eggs unwind as they are beaten and hold the pumpkin and liquids in a gentle mesh. As it cooks, it coagulates or sets and forms a custard-like filling. If the filling is cooked too long, the protein network contracts and shrinks, causing the filling to crack across the top. To prevent the cracking, cook it a little less this year. Remove it from the oven while the center still jiggles slightly if you give it a gentle shake. It may look like it still needs a little more cooking, but remember because of latent heat, it will continue to cook after it is removed from the oven.

Why Hot Sauce is Hot…..

By Fernando Luna Vera

Ph.D. Candidate, Chemistry Department, VCU

Science Museum of Virginia Volunteer

“Can you please pass me the hot sauce?” a friend of mine asked. “This one?” I replied, holding up and showing him a warm spinach dip cup. “No! The spicy one,” he said. As I passed it to him, I mentally wondered an almost childish question, “Why do we call it hot sauce if it is not really hot…nor is it even served warm!” Appreciating and feeling the taste of food involves a complex mechanism that uses the sense of taste, smell and touch. This rise of sensations and perceptions sparked by food requires hundreds of chemical signals and our brain acting as traffic officer to control them.

After you bite a spicy taco your body can recognize that familiar, pungency sensation thanks to a well equipped network of sensors called neurons. Neurons, as do all animal cells, contain a boundary layer called a membrane, where specific receptors are allocated. These receptors are like the geometric figures on the surface of a shape sorter toy which recognizes specific shapes. Certain neurons, called nociceptors, have the specialized job of sensing pain. These kinds of neurons contain a specific receptor for capsaicin, the molecule found in high concentration within chili peppers. One can image then, capsaicin molecules traveling to the tongue and getting caught later by the nociceptors, which immediately after recognizing them, trigger an electrical signal that travels to the brain and makes us aware of the irritating sensation of the hot sauce. That specific capsaicin receptor is called TRPV-1.

But why does our brain read the signal produced by capsaicin as an increment in temperature? An experiment performed in 2000 by scientist of UCLA helped us to better understand this outcome. By using genetic techniques, they “knocked out” the gene that produces the capsaicin receptor (TRPV-1) from a group of mice and compared it with other group that still had the TRPV-1. After exposing the two groups to capsaicin, the one lacking TRPV-1 showed to be insensitive to the irritant substance, as expected. However, surprisingly the same group showed a high insensibility to temperatures above 43ºC, which is when pain is normally sensed. This result implied that the same receptor for the chili peppers irritant molecule is the same receptor for sensing high temperature. So when neurons bind capsaicin, the brain interprets the signal produced as an increase in temperature, like something “hot” is touching your tongue.

Additionally, neurons possess certain receptors called TRM8, which are activated by low temperatures (> 12 ºC). These receptors also happen to be sensitive to menthol, the compound found in high concentration within peppermint and used in products like mouthwashes and toothpaste. By then using the same mechanism for associating capsaicin and hot temperatures, the menthol bond to a TRM8 receptor sends a signal that tricks the brain; therefore, by just the taste of mint, makes you feel cool!

References:

http://student.biology.arizona.edu/honors2007/group12/home12.html

Sven-Eric Jordt, David D McKemy and David Julius, Current Opinion in Neurobiology, 2003, 13:487–492.

M. J. Caterina, A. Lefßer, A. B. Malmberg, W. J. Martin, J. Trafton, K. R. Petersen-Zeitz, M. Koltzenburg, A. I. Basbaum, D. Julius, Science, 2000, 288, 306-313

Flying Squirrels Play Baseball?

Play ball! It’s Opening Day at the Diamond! Today Richmond welcomes its new baseball team, the Richmond Flying Squirrels, with a sold-out Diamond! So why Flying Squirrels???
Well, flying squirrels are rather cute! And Virginia boasts 2 species: the Northern Flying Squirrel, whose range includes a few isolated high altitude locations (it is more common in states farther north) and the Southern Flying Squirrel, whose range includes the entire state except its westernmost tip.
Flying squirrels are nocturnal so they are rarely seen by humans. Their eyes are quite large to help them see in the dark. They spend most of their time high up in trees but come to the ground occasionally to hunt for food. Their predators are creatures of the night, including owls, raccoons, weasels, coyotes and domestic cats.
Flying squirrels do not actually fly but glide. Gliding is facilitated by the patagium, a flap of skin between the front and hind legs, which acts as a sort of parachute when the squirrel jumps from a tree. The patagium contains muscles that hold it taut while gliding and keep it close to the body while at rest. The fur on the patagium is short to reduce air flow resistance or drag.
A flying squirrel’s diet includes mast crops (acorns, hickory nuts, pecans, walnuts), seeds, insects, snails, plant buds and flowers, fruit, fungi, tree bark and sap. Flying squirrels are “scatter hoarders,” often stashing small quantities of nuts in tree notches and in shallow digs under leaf litter and logs. Southern Flying Squirrels are also known to store larger quantities of nuts and other “goodies” in "larder cavities."
For shelter, flying squirrels use several types of nests. The most common nest type is the cavity nest, often a natural tree cavity or a tree cavity made and then abandoned by another animal. In summer, flying squirrels often use outside nests called “dreys,” which are usually made of plant material. Aggregate nests are often used in winter. Flying squirrels are the most social of all squirrel species and they do not hibernate; therefore, to keep warm in winter, they will gather in a communal or aggregate nest for warmth. Other nesting sites may include birdhouses, stacked firewood and attics. We had flying squirrels living in our attic for a couple of winters until we figured out how to humanely “evict” them, but that is a story for another day…

Most of this material came from http://www.flyingsquirrels.com/ , an excellent source for almost anything you’d like to know about flying squirrels. Information more specific to Virginia can be found at http://www.dgif.virginia.gov/wildlife/information/?s=050068 and http://www.dgif.virginia.gov/wildlife/information/?s=050065.

Something From Nothing

This spring, I've been tasked with creating a one-acre farm for the Science Museum of Virginia. Ever since I was a child, I've been fascinated with growing plants. I still remember growing a bean in a wet paper towel wadded up into a baby food jar when I was in third grade. I remember my fourth grade teacher taking us to her parents' farm to visit on a field trip. It's experiences like these that I hope to be able to pass on to a new generation of students.

I'm excited and lucky that Richmond Public Schools will be growing plants for our garden. I'm still hammering out the details about which grade level to focus on and how many schools we'll have participate. I have, howevver, developed a proposal of what I'd like them to do. I'm hoping to do a small-ish demonstration "pizza garden" as part of our acre. They've been done before. I'm not looking to reinvent the wheel. It would be a 15- to 20-foot round bed divided into slices. Each slice would be an ingredient found on pizza. A slice of tomato plants, a slice of pepper plants, a slice of jalapeno pepper plants, a slice of onions, a slice of basil and a slice of oregano. There are 29 elementary schools in Richmond. I'd like to cover every third grade class in every school. We'll see what happens!

We've partnered with Tricycle Gardens to make this farm happen. Check them out at www.tricyclegardens.org. They're doing some pretty cool stuff throughout the city. I spoke with Lisa Taranto, our Tricycle Gardens contact, about what types of growing experiments we could potentially do in our garden. There was a brief discussion of permaculture gardening, which is similar to companion planting, but focuses more on planting some items that serve only to enrich the soil and cause a different crop to grow better (I think!). It sounds quite interesting.

So what does someone need to do to get an idea like this off the ground? Well money doesn't hurt! The museum has been lucky to receive a grant from the Gwathmey Trust for $30,000. We're hoping to build a small greenhouse onsite. We'll also need to purchase all the tools necessary to maintain a farm, as well as topsoil, manure, etc. For irrigation, we're using a rainwater harvesting cistern that will be constructed onsite thanks to a separate National Fish and Wildlife Foundation grant. This system will harvest rainwater from the IMAX Dome and pump it out to the farm. I'm not sure of the date of completion for this system, so we may need to figure another watering system out in the meantime. I believe the first item on my plate, however, will be soil testing.

Today I bought a small "greenhouse" kit, some potting soil and seeds. Tomorrow I plan to get those started just to get myself in a growing frame of mind. This will also allow me to see how long it will take to germinate the various plants I hope the RPS kids will grow for us.

Guess that's all for now!

Which vegetable is #1?

Would you believe it’s the sweet potato? According to nutritionists at the Center for Science and Public Interest, the sweet potato ranked #1 in nutrition when compared to other vegetables. Foods were given points for their content of dietary fiber, naturally occurring sugars and complex carbohydrates, protein, vitamins A and C, iron and calcium. Points were deducted for fat content, sodium, cholesterol, added refined sugars and caffeine. The sweet potato, with a score of 184, easily beat out the second place vegetable, the white potato, by more than 100 points. It’s easy to see why: sweet potatoes have twice the daily allowance of vitamin A, 42% of the vitamin C recommendation and 4 times the RDA of beta carotene. So this Thanksgiving Day, enjoy this yummy and good-for-you treat!