Corpse Flies

Flesh flies, otherwise known as sarcophagus flies feed on dead or decaying tissue. They're in incredible asset to forensic entomologists because certain species of Sarcophagidae will lay eggs OR live larvae on the body at a certain stage of decay. In other words, some flies like it warm. Others like it cold, and yet others like it nice and mushy. But based on the life cycle of the fly maggot/pupae, forensic entomologists can determine when the individual died.

See a lot of flies like these buzzing around? Chances are that you're at a farm (they eat manure too), something died (like that mouse in the wall of your basement), or your neighbor is hiding something.

On Aging and Memory

A friend of mine asked me a question relating to aging and memory loss. I thought that it would make a great blog topic, so I put my response here! ^.^

Aging is caused by two factors, both linked to cell division. Cells divide and grow for three purposes: growth of organism, replacement of dead/dying cells, and fortifying the immune system during an infection. Obviously as adults, we no longer grow, so our cells must divide in order to replace other cells. The process of a cell division is called mitosis.

As we age, we lose our ability for our cells to divide. -Cells have the ability to divide continually for a certain amount of time, then as we age, this ability gets lost. This is the reason why older individuals have a very hard time healing, whereas young kids seem to heal overnight!

Why do we lose the ability to divide? The theory is that each time we divide, our cells have to make a new copy of DNA to go into the next cell, right? Well, each time we make a copy, we lose bits of DNA, called telomeres in the process. These telomeres protect the actual ends of the DNA, and keep it from going crazy and haywire. Because they get shorter each time a cell divides, eventually, they run out. The current theory is that THIS is what causes aging.

Think about a photocopy of a sheet of paper. In the "first generation," the original copy and the photocopy don't look very different. But if I keep photocopying the copies of paper, eventually, I begin to lose resolution, things get blurry and fuzzy, and after a long amount of time, you begin to start losing important bits of information.... signs of aging.

-Incidentally, this is also a problem that we are encountering with the cloning process. It seems that when you make a clone using "old" DNA, the organisms that come from it also seem to be "aged" as well, and can suffer complications.

Now the mechanism behind memory loss is different. In general, our brain cells and nerve cells don't divide. This is why when someone has nerve damage, it's usually permanent. There's a lot of research on nerve tissue regeneration (and a whole lot of discussion on stem cells), but right now, we're not there yet. Anyways, we retain a set number of brain cells that retain our memories. However, like the rest of our body, eventually, the "machinery" runs down, and our cells begin to die. Because we can't replace these cells, our memory starts to go away because we don't have as many brain cells as we did before.

*As a sidenote, when you drink alcohol, you kill brain cells. The theory that you get stupider the more you drink? Yup. 'fraid so.

Although another new theory has come out in regards to memory as well. The idea is that we have not necessarily lost our memory cells per se, but we have become desensitized to the things around us. We lose our awareness of the things such as routines, and therefore, do not commit them to memory like we did when we were younger. Studies have shown that when older individuals go through mental exercises to practice mental awareness, they can actually increase memory retention!

So memory loss is actually caused by two things: dead brain cells, and loss of mental awareness and acuity.

What do we do about it? Go to your nearest biotech company and present them with a big fat check to help stimulate the economy of course!

Maryland Entomology

My first year in Maryland, I've encountered hummingbird-sized wasps, vampire mosquito hordes, and creatures that have way too many legs and move too fast for my comfort. I won't even go into the size of the spiders.

After a thorough research investigation (like bringing in a dead bug to my co-workers and asking them what the heck the thing is), here are a few insects that I have NEVER seen on the West coast but seem to thrive in the Maryland ecosystem:

1. Scutigera coleoptrata, otherwise known as the house centipede. The first time I saw one of these dashing across my basement at speeds faster than a German cockroach, I practically jumped out of my skin. Their legs are like long hairs, and they have eyes and antennae. I was so creaped out that the only thing left of it was a smudge on the wall and an indentation where I was a tad bit overzealous with my shoe.

Surprisingly, these little guys are actually quite beneficial in the house. They eat insects. What I don't like is that they inject venom through a pair of their legs, and that, although rare, it can penetrate human skin. Bleh.

2. Vespa crabro, or the European hornet, likes to hunt at night. Another insectivore, these large and very loud insects hunt yellow jackets and bees. They also like to fly into your house at night when you leave the porch light on and it takes approximately half a can of Raid and 15 minutes to kill one. It probably takes a little longer if we didn't squish it with a shoe after it falls, buzzing angrily across the wood floor. They have a nasty sting, and I'm making sure I never get to experience it! Next spring when they buzz around again, I may try smacking these 1.5 inchers with a baseball bat, but I have this fear that it'll come chasing after me.

3. Photinus pyralis, or the firefly, has become one of my most favorite insects of all time. Considering that I've never seen one until moving to Maryland, you can only imagine my childlike wonderment at seeing green and yellow glowing lights almost magically zipping around and disappearing in clumps of woods in our front yard. I remember driving home from work, almost crashing into the neighbor's car as I watched their magical dance across my lawn. First thing I did, dressed in a smart business suit and slim boots, mind you, was to jump out of my car and catch one in the garden! OMG! THEY'RE BEETLES!!! Too cool. I have to admit, both my son and I thoroughly enjoyed watching the jar full of fireflies under the covers that night. ^.^

We let them all go in the morning, of course.

Rumor Bustin'

Two nasty biological rumors that I want to clarify and set aside for the general benefit of mankind:

1. Being cold will make you catch a cold.

My mother still believes this. However, you can't catch a cold unless you have a virus first! No virus = no cold. Why is it that we get more colds in the winter? For one, school is in session, and unfortunately, classrooms are a virtual cesspool for spreading diseases. Also, people tend to stay indoors where the likely hood of contact with an infectious person increases.

Bottom line: You have a higher chance of catching a cold by licking a doorknob than being outside in zero degree weather with just your skivvies on.

2. Cloning is bad because Hitler will be reborn and take over the world.

Psht! First of all, clones are genetically identical. That's it. Identical twins are clones. The cells in your body are clones. Did you know that your eye cell, your bone cell, and your nerve cells are clones? They have (hopefully) the same genetic makeup, do they not? But do they look alike? Nope!

Just because an individual has the same genetic makeup as another individual doesn't mean they will be or act the same. Hitler's clone could grow to be the world's greatest figure skater for all we know!

Also, this rumor that we mad, evil scientists are making clones of each other in the lab so that we can rip out their organs for medical research? ...not happening. Here's why:

a. Remember Dolly the cloned sheep? It took 227 surrogate ewes (female sheep) in order to produce one successful Dolly. Last I checked, we don't have that many human women willing to do something like that.

b. By the time the clone reaches an age where its organs would be "ripe" for harvesting, you will either be dead already, or too old to care.

c. Your clone, being a complete, sentient individual with human rights like you, will probably protest.

d. It's illegal.

Incidentally, we eat cloned cattle all the time. Plants...MOST plants that we eat are now produced from clones (been doing it since forever). In fact, most bananas are genetically identical!

Can you clone your cat? Well, yes. In 2001, CC (stands for Copy Cat) was the first cloned cat produced by Genetic Savings and Clone. Unfortunately, the company went belly up in 2006. Is it possible that we'll have another pet cloning service in the future?
ABSOLUTELY!

Maybe after the recession picks up though... >.>

Democracy Among the Microbes

In light of today's historical events, I decided to NOT talk about our new president. I figure there's a lot of other bloggers out there that can do a way better job of it than I can! So instead, I shall talk about democracy of a different kind: quorum sensing.

In a nutshell, quorum sensing is how certain bacterial communities determine when to do something once they reach a particular population density. What they "do" depends on bacterial species and where that particular species is growing.

For example, see that picture of glowing green bacteria? These bacteria, found in squid eyes, are called Vibrio fischeri. At populations of less than 10^11, (that's a 1 with 11 zeros behind it), they don't glow. However, when they reach populations of over 100,000,000,000 cells, we get glow!!!

Bacteria also use quorum sensing to secret toxins that stop the growth of other bacteria. -Or to orchestrate an effort to suddenly overthrow a host's immune system and give it a bad case of pneumonia! Muhuhahahaaa!

In any case, quorum sensing allows bacteria to not only sense how many other bacterial cells are out there, but it also directs a large population of bacteria into doing something that, in small numbers, would be impossible to do.

How is it done? Err... that would be a topic for another day.

Quorum sensing - committees that actually work!

Nude Mice and Naked Chickens

There's a difference between a genetically modified organism (GMO) and a selectively bred animal. Selective breeding involves grabbing a boy animal and a girl animal, a comfy nest or bedding material, low lights and lots of Barry White. -This is the "traditional" method.

GMO organisms involve the manipulation of specific genes in a lab (under ultra sterile conditions), lots of petri dishes, and the ambiance akin to a dentist's office with a running drill. In both cases, the organisms come out with (hopefully) traits that we want.

Take the featherless chicken, which was created purely from selective breeding. This "greener" chicken produces no feathers to clog up landfills and pollute the environment like a typical chicken would. There's a lot of opposition towards its existence even though, in the traditional sense, these chickens are no more Frankensteinish than your pure bred German Shepherd. It's hideous looking, as you can see, and more susceptible to sunburns, parasites and other things.

Another selectively bred animal is the nude mouse. Bred since 1937 (before GMO technology), this mouse has no immune system. Because of that, nude mice have helped studies such as leukemia, cancer, organ transplantation and many, many others. From the picture, you can probably surmise why the nude mouse got it's name.

Seriously though....

...aren't all mice nude?

Green Ham?! Triumph of the GloPig!

Another biotech miracle, or freak of nature:GloPigs!

Well, actually they aren't called that. BUT, these little piggies DO glow green when hit with a blacklight. In fact, when these green porkers first came out in 2006, it was a HUGE deal in the scientific community too! Here's why:

A glopig is actually a transgenic animal. -An animal that has had its genes altered. In other words, Taiwanese scientists placed a jellyfish gene into their pigs' DNA to make it glow. Now, before you guys freak out on me, do understand that we've been messing with genes for YEARS! DECADES! CENTURIES! I mean, do you think that something like this sharpei is normal?!

Before the advent of gene splicing, humans have been altering genes through a process called artificial selection. This is how we've made such foods like corn and tomatoes, and animals like cows, chickens and chihuahuas. Cows and chickens were "domesticated," meaning that before gene technology, we picked the dumbest, meatiest, tastiest animals we could find to breed. Corn is an actual genetic derivative of maize, a naturally occurring plant similar to wheat...a weed!

Current biotech, and transgenic organisms are just a better, more efficient, sexier way of swapping genes than artificial selection. We still get what we want without the nasty side effects (think about that little doggie up there). Besides, it'd be damned near impossible to breed a pig with a jellyfish... Even Barry White can't help us with that one!

Anyhoo, going back to glopigs... The idea of putting a glowing gene into an animal's DNA has been around for quite a while to study and understand gene expression. Thinking back to basic bio, remember that not all of our genes are turned on at the same time. By putting a glowing gene into specific places in our DNA, you can figure out what genes are turned "on" (when it glows) and what's turned "off."

Case in point, look at these mice. The jellyfish gene, which codes for the Green Fluorescent Protein, or GFP, only glows in their ears, tail and feet. What this means is that the particular gene that these scientists are studying is ONLY turned on in these areas.

By knowing where genes are expressed, and HOW they get expressed, we can find better ways to control certain genetic defects or disorders. Conversely, if we can find genes that are expressed everywhere and every time, we may be able to find gene therapies for the entire animal. Remember "gene therapy?" It was a huge thing in the 80's and 90's.

Dr. Wu Shinn-Chih's glopigs are a hit because he was the first one to express GFP in the entire organism! The FIRST!!! The ENTIRE organism! Meaning, green skin, green eyes, green liver, green tongue, green BACON. Green everything! Now THAT is pretty damn cool.

Once we get chickens involved, we've got Dr. Suess's book allllll taken care of!

Green Eggs and Ham anyone?

On Farting, Flatulence and Making Cheese

Gas. Everyone has it. In fact, we poot 1-4 pints of gas (called flatus) on an average of 14 times a day!

What causes it? We eat, drink, and swallow small amounts of air which can either be released through belching or, if it goes through the entire system, farting.

As Colin Powell will tell you though, flatus isn't JUST about the intake of air. Hence the term, "Silent but deadly." In addition to ingested air, the bacteria in our lower intestine LOVE to break down certain carbohydrates found in foods. This breakdown creates a combination of byproducts such as hydrogen, methane and sulfur! (The stinky egg smell that brings tears to your eyes.) These gasses build up in our lower intestine and rectum until thar she blows.

Incidentally flatus, only it's not called flatus, is what forms the holes in swiss cheese. To make swiss cheese, bacteria are introduced into a milk/enzyme slushie and incubated at body temperature. As the cheese forms, bacteria eat the lactose (a type of sugar) in the milk and produce gas. This gas gets trapped and makes holey cheese! Fondue anyone?

...and you wonder why they call it, "Cutting the cheese..."

More farting facts:

1. The "fart" you hear from ripping one is caused by (and I quote from Wikipedia) "vibration of the anal sphincter, and occasionally by the closed buttocks." So instead of clenching to hold the gas in, unclench and let your flatus go! If it's silent, maybe someone else will get the blame.

2. One third of the human population actually produces methane in their flatus. How do you know if your among the lucky 33.3%? Your feces floats!

3. Flatus odor varies depending on a person's unique bacterial mix in their lower intestine, and on what they ate. Take broccoli for instance. In some people, it's a harmless vegetable. To others, it becomes a deadly biological weapon of war and mass destruction. Broccoli + Fluffy = Destroyer of Worlds.

4. Bacteria love carbohydrates like fiber and sugar (found in beans, legumes and fruits). Eat a low carb diet high in fat and protein, and chances are that your gasage will significantly decrease.

5. Beano is an enzyme product you can buy over the counter to silence one's chuff. It works by breaking down raffinose, a sugar found in beans, before it gets to the gas-producing microbes in your lower intestine. Go Biotech!

6. Can you light a fart? I have no idea! But when I lived in an apartment with four guys in college, it helped to keep a box of matches in the bathroom. Believe it or not, it's more effective than an air freshener after a post poop experience.

7. Herrings communicate with each other by farting at night. Fish fart?! Yup! Check it out!

8. Want more? How about a Farting Blog!

9. Run out of fun vocabulary for describing one's toot? Go to the Unabridged Dictionary of Fart Slang." There you'll find ways to colorfully describe your natural passage of gas. My favorite? ASSASSINATION! Get it? :D

Fine, I'll stop writing before my samurai takes away the keyboard...

Toot away my biological brethren!

Dance of the Banana Slug - Yes, Size DOES Matter!

Up in the redwood covered mountains of Santa Cruz, CA, bright yellow mollusks called banana slugs reside in great abundance. Larger than the palm of your hand, rumor has it that their slime tastes like bananas. However, I've never had the guts to lick one myself, nor have I found a victim willing to do it for me as of yet.

In addition to their unusual appearance, banana slugs are also hermaphroditic and possess hunormous penises. In fact, in the Latin name of one species of banana slug, Ariolimax dolichophallus, dolichophallus means "giant penis." So much so that during mating, if the penis gets *ahem* stuck, its mate will chew it off in a process called "apophallation". (Who said biologists don't have a sense of humor?)

No wonder it's the mascot for U.C. Santa Cruz!

For more info on strange animal mating habits, check out the Neatorama blog. They had stuff even I didn't know!!!

If I Were A Squirrel, My Nuts Would Be Frozen

To quote my boss, "It's colder than a witch's tit out there!" Struggling to survive yet another butt-arsed cold Maryland winter using a fire, blankets and hot cocoa (I'm not allowed to have coffee after what I did Thursday night… >.<), this tropical Californian transplant looks outside to see our resident squirrel boinging his furry little body on the bungie, stealing more dried corn and sunflower from the feeder.

WHOA. I thought squirrels hibernated!

Not so. After a brief internet research expedition on Squirrel Facts, it turns out that in winter, tree squirrels stay active while most ground squirrels hibernate. To survive, tree squirrels rely on nut reserves that they buried in the dirt and stored in trees during summer and fall. They also supplement their winter fare with the occasional foraged juicy bug, dried corn, peanut or eggroll.

According to Wiki, there's differing degrees of hibernation depending on the species. Hibernation means that the animal goes into a deep 'sleep.' Breathing and metabolism slow down to an almost undetectable crawl and the body temperature drops. A "true" hibernator, like frogs, are unresponsive throughout the winter. They cannot be roused in any way unless you raise the temperature.

Other types of hibernators sleep for intermittent periods of time, waking up occasionally to forage for food and water. I've got a few Biotech students like this. Fortunately, the vending machines are one floor away, so they can quickly find sustenance before returning to their winter slumber in class.

You're probably wondering, "What do frogs and turtles do during the winter?". Fear not dear reader, for I have the answer! Frogwatch says that aquatic frogs and turtles bury themselves in the leaf litter and dirt at the pond bottom. During this time, frogs become inactive and "mushy"; looking rather dead and brown. As long as the pond doesn't freeze over, and as long as the frog isn't moldy, decomposing, or upside-down, they're fine!

If you have an overwintering pet turtle, keep him in a box of dry straw in a cool place. Again, as long as he doesn't start to smell bad, Raphael will be back weilding his sai when things warm up in spring.

Remember the differing degrees of hibernation? Enchanted Learning's Hibernating Animal page, and the Environmental Education for Kids page can help you tell the difference! Bats, woodchucks and ground squirrels are true hibernators. Hibernating skunks and bears are not, and can be easily roused from their winter beauty sleep.

My advice? Think twice about kicking that sleeping bear. Otherwise, you'll become its Christmas dinner! Incidentally, it's okay to disturb a hibernating student. They may actually learn something from the experience.

Here's another cute book in case you're interested: Children's Book on Wintering Animals

Stay warm and cozy everyone!