Sunday, October 28, 2012

so far, this school year has been a killer, so i'm on a hiatus of an undetermined length. i'm hoping to be back in 2013.

Sunday, September 9, 2012

bats on 'science friday'

image via WSSU ram pages

so obviously i have to share this. this past friday, 'science friday' featured the research of nickolay hristov of UNC's center for design innovation and winston-salem state university, pictured above. hristov specializes in using technology to better capture the flight of bats and better understand what goes on in a bat cave during the day. there's a really beautiful video on the science friday website, but the code for embedding it is incomplete, so i can't post it here. you'll just have to go check it out.

a little more background on the brazilian free-tailed bats at the beginning of the video: i believe the bats pictured are leaving bracken cave, outside san antonio. if i'm right, they are all males. where are all the ladies, you ask? well, they summer under the congress avenue bridge in austin. they give birth to their pups under the bridge, and they'll meet up with the males again when they head south for the winter to escape the cold, and, uh, make more bats.

want to learn more about brazilian free-tailed bats? check bat conservation international's species profile.

want to learn more about dr. hristov's work? check out this article from 'science careers.'

Monday, June 11, 2012

the original human social network

the misunderstood hero of our story. it's the brown part. image via wikipedia.

i have felt for some time that the whole 'kill 'em all' anti-bacterial craze is maybe not the best thing ever, and i am not alone--just look at all the probiotic supplements on the market. however, we're still treating just about everything with antibiotics and slathering ourselves in hand sanitizer. we want the bacteria we have designated as good in our bellies and THAT IS ALL, THANK YOU. fueled by the idea that the existence of some good bacteria might mean that there are more good bacteria, researchers have been working hard to identify the types of bacteria we carry around with us, how much this varies from person to person, and what exactly those bacteria are doing that might be helpful, harmful, or neutral to humans.

this month's issue of 'scientific american' has a great cover story this month that summarizes some of the findings from this research. a few facts to set the stage: there are more bacterial cells living in or on us that there are cells that make up our bodies. if you watched bonnie bassler's ted talk that i posted a few months ago, then you might remember her saying that she thinks of us as mostly made of bacteria with a little bit of human thrown in. furthermore, if you pool the genomes of all the different bacterial species that take up residence on humans, there are way, way more bacterial genes in use than human genes.

if you aren't sure of the significance of this, you can think of every gene being responsible for making at least one protein. your body can't do much of anything without an army of proteins, particularly the chemical-reaction-stoking set of proteins known as enzymes. need oxygen? then you need some hemoglobin in your bloodstream. hemoglobin is a protein. want to digest the ice cream you just ate? then you need some lactase in your stomach, the enzyme that breaks down the lactose found in dairy. i think you see where i'm going with this: proteins, like ron burgundy, are kind of a big deal.

microorganisms that might live somewhere in or on your body. image via pharmaceutical microbiology.

so let's recap: we have millions of bacteria living somewhere in or on our bodies, and those bacteria are making millions of different proteins and enzymes, some of which will be secreted outside of their little cell bodies and into our own human bodies. finding out what these proteins are doing in our bodies and how important that is is a major area of current research. are the bacterial proteins helpful? are they harmful? are any of them so helpful that they are, in fact, totally necessary for our bodies to function as they should? we tend to think of bacteria as harmful, causing issues that require a trip to the doctor and a course or two of antibiotics, but what if we need them just as much as they need us?

if you want all the details, you should obviously go buy the current issue of 'scientific american,' but i am going to share a bit about one of the parasitic-turned-commensal species of bacteria, and it's going to get personal. there's this one species of bacteria that has been blamed for intestinal conditions like chronic acid reflux (also known as GERD), stomach ulcers, and even stomach cancer. it's name is H. pylori, and most people have it. not all people who have an H. pylori infection will develop these symptoms, and someone can have GERD without ulcers and ulcers without cancer. like many things biological, it varies from individual to individual. in other words, H. pylori is one bad mother, and, if you have it, you should definitely take antibiotics immediately to get rid of it. or that is what a doctor might tell you, if you go to them complaining that your heartburn medicine has stopped working, like i did this past fall.

making the stomach a safer place? image via Helicobacter pylori symptoms.

well, well, well, lo and behold, new studies show that H. pylori is probably not a parasite at all. in fact, not only is likely not a parasite, but it is quite possibly extremely important to the functioning of a healthy human stomach. it seems that these tiniest of guys play a role in maintaining the optimal pH of the stomach. the contents of your stomach need to be very acidic, but not any more so than a pH of 2. when the pH drops below this, bad things happen. maybe even bad things like GERD. there do seem to be a small percentage of people whose body just doesn't like some of the proteins produced by H. pylori, and these people do have some of the GERD/ulcers kind of issues. but again, we're talking about a small percentage.

H. pylori "infection" is probably so common because it helps your body maintain itself. we need this bacterium to function properly, so it probably isn't a good thing that my screening for the bacterium came back negative. why don't i and others have it? well, as my doctor knows, it's pretty easy to kill H. pylori with a round of antibiotics. while there might not really be enough research completed at this point to make this call, i'm going to suggest that my GERD might actually be caused the absence of H. pylori. it doesn't explain all of my symptoms, but it does suggest a possible reason for the hyper-acidic pit of pain i get in my stomach that lets me know it's time to chug some alka-seltzer. so maybe instead of prescribing a round of antibiotics for those who test positive for H. pylori, we need to "infect" those whose test results come back negative. when you take antibiotics, maybe you also get a prescription for a probiotic to replace the good bacteria you will certainly accidentally destroy along with the bad. and maybe, just in general, we should drop the obsession with cleanliness. we really know so little about the bacterial world, but we do know that we have been coexisting with them well before there were antibiotics. there are some nasty buggers are there for sure, but it seems like the vast majority of them might be friendly. let's give them a chance to help us.

**disclaimer: if you, like me, have a freakish case of GERD, please do not take medicine into your own hands and try to infect yourself with bacteria. let's try to be patient and wait for medicine to catch up with us.

Wednesday, April 25, 2012

the tiniest social network: addendum

those of you who watched bonnie bassler's ted talk below already know about this, but i feel like this is important to point out:

social networking at its most useful? courtesy of xkcd
not everyone loves social behavior like i do. there aren't even that many biologists that would consider sitting down to construct a social network (yes, that's something other than facebook) to be fun. however, everyone gets sick, and often that sickness is due to bacterial infection.

you've probably heard about the problem of antibiotic resistance. when bacteria are exposed to antibiotics some of them randomly have genes that give them to resistance to the drug. if the drug kills bacteria by popping their cell membranes, these bacteria are un-poppable. the bacteria survive the antibiotic invasion, and can live another day. they obviously have a huge genetic advantage in environments where antibiotics are present, and, because it's genetic, their offspring will also be resistant. because bacteria reproduce so quickly, before you know it, you have an entire population of drug-resistant bacteria. (hello, evolution!)

image via health news

different strains of bacteria can become resistant to entire suites of antibiotics, and then those infections become very, very hard to treat. MRSA (aka Staph infection) has been in the news quite a bit lately as a strain of bacteria that is particularly hard to treat. MRSA stands for methicillin-resistanct Staphylococcus aureus, methicillin being an antibiotic, and S. aureus being the bacterial species. MRSA isn't just resistant to methicillin. methicillin was developed specifically to deal with bacterial infections resistant to penicillin. this is the state of medicine: bacteria respond to antibiotics as quickly as or even faster than we can synthesize new ones.

here's where the bassler lab comes into play: bacteria do not produce the toxins that make you sick if they are alone. they just hang out and wait for the population to get large enough to do some damage. if you can convince a population of bacteria that they are alone, they will stop producing toxins. once the toxins are good, you will start to feel better, and your immune system can clear the infection. read more about this concept and the work the bassler lab has been doing at their lab website.

Tuesday, April 24, 2012

the tiniest social network

for those of you who don't know me personally, before i became a teacher i got a master's degree in biology. even though i no longer do my own research, i still get excited about all of the research coming out of academia, especially those studies related to animals. i have a tendency to think that anything related to animal behavior is far superior to just about anything else.

attending an AP bio prep session with my students a few weeks ago, one of the presenters showed the ted talk above, and it BLEW. MY. FREAKING. MIND. 

as i said, i'm typically not much for single-celled organisms, so i had never really considered bacteria as a source of interesting research. a terribly ignorant bias, i know. obviously research on bacteria is important; it can help keep you healthy, but interesting? related to my love of social behavior? i think not. or i thought not, until i heard bonnie bassler speak.

turns out, bacteria communicate using small chemicals that they excrete and receive from other individuals. not only do they communicate, they use these chemical 'words' to make collective decisions in a process called quorum sensing. 

those decisions can result in something pretty (make fluorescent protein and glow) or something harmful (release toxic chemicals and try to overthrow the human host) among other things. looks like the greeks weren't the first to invent democracy after all.

as a grad student, i studied things like how animals make decisions and interact with others with the unconscious assumption that a brain would be a prerequisite for such behavior. oh how wrong i was. the ancient, single-celled versions of life we are constantly trying to kill with hand sanitizer and clorox are talking to each other, and i would guess they've been doing this since before humans were even on the scene. they can talk to members of their own species, and, even crazier, they can talk to members of other species. there are species-specific chemical messages as well as chemical messages that bacteria of all stripes can understand.

just think about that for a second... while we tend to lump bacteria into one big group, they are actually extremely diverse. 

it would be a bit like humans all being able to communicate with a single language, and then also having a separate 'mammals' language. 

when was the last time you got together with all the mammals in your neighborhood for a meeting? never, you say? well bacteria are doing it all the time. no wonder they've been here so long.

have you ever learned something about science that was totally unexpected? when was the last time someone shared something scientific with you that changed the way you view the world? please share your eye-opening experiences here. i would love to hear them!

want to learn more about bacteria and quorum sensing? click here for information about the bassler lab.

Sunday, April 15, 2012

on the lighter side...

image via skip dinner, have a big dessert

let's end bat appreciation week on a positive note, and what's more positive than good food and adorable baby animals?

one of my favorite cookbooks is called "bats in the pantry," put together by the wonderful people at bat world sanctuary. not only are the recipes delicious, but there are also bat facts sprinkled throughout the pages and a bat icon by each ingredient brought to you by bats. a little more about bats from dottie hyatt, vice president of bat world sanctuary:

"roughly one out of every four mammals on earth is a bat. consider this: if your day includes soap, shampoo, cosmetics, a toothbrush and toothpaste, coffee, margarine, paper or ink, cushions, wood furniture, fuel or lubricating fluids, rope or twine, timber, boats or canoes, ornamental trees, life-saving medicines, air fresheners, candles, rubber, chewing gum, spices, vegetables, fruits, chocolate or even margaritas and beer, you are are not only involved with bats, you are dependent upon bats. yes, it is true."

that's the thing about science: it happens whether you notice it or not.

even if you are not aware of bats, you benefit from them. you will also be touched by their dwindling numbers in the form of higher prices on the goods listed above.

image via cute overload

ok, i promised a lighter post after yesterday's WNS downer. to bring bat appreciation week to a close, i'm going to make a chilled cream of mango soup, garnished with blueberries and strawberries, and stuffed squash, both recipes from "bats in the pantry." pull out your favorite mango or squash recipe, and then watch this video about baby fruit bats. be warned: it doesn't get much cuter than baby bats wrapped in blankets. prepare for cute overload.

what did you learn from bat appreciation week? what are your favorite mango or squash recipes? will you be toasting bats with a beer or margarita? does it get any cuter than this?

image via zooborns
**all of the images in this post are of orphaned bats living in bat sanctuaries. if you have been touched by this or any other post in my bat appreciation week series, please consider donating to bat conservation international, bat world sanctuary, lubee bat conservancy, or one of the many other bat conservancy groups around the world.

Friday, April 13, 2012

breaking news on white-nose syndrome

the already-endangered indiana myotis, one of the faces of WNS
image via the daily green

a new study confirms that white-nose syndrome, a fungal infection devastating bat populations throughout north america, came from europe and arrived here via humans. if you're familiar with white-nose syndrome, i don't think this comes as a surprise. it travels from cave to cave incredibly quickly for a non-motile fungus, and animals rarely travel from caves in new england to caves in tennessee in a matter of months. people are really the only vector capable of spreading a disease so quickly.

if you aren't familiar with white-nose syndrome, it is unbelievably depressing and horrifying. the disease is caused by a fungus that grows over the bat's face, and it causes the bat to come out of hibernation early. small, insect-eating bats like the ones that tend to hibernate in caves stay asleep until there are sufficient insects to eat. when they wake up early, they fly around night after night searching for food that isn't there. they quickly burn through their winter fat reserves, and you can guess the end result: the bats end up starving to death (assuming they don't freeze to death first), and the fungus continues to spread until it reaches the entire colony. a bat colony can be made up of thousands of bats, so we're talking catastrophic die-outs. some bats are able to survive the fungus, but, in general, animals that live in large colonies don't always fare so well in small numbers. the mortality rate in many caves is very close to 100%.

gray myotis, doing what it does best
image also via the daily green

there has been some reluctance on the part of the park service to close the caves where bats live to human traffic. i get it--you make money from tourists who want to explore the caves, but is that revenue worth millions of lives? so far, the death toll is around 5.7 million bats. that's slightly less than the population of los angeles and houston combined. i don't think you have to be obsessed with bats to know that 5.7 million is an astounding number of lives to lose.

the virginia big-eared bat, via the ward house

if you read my inaugural post, you know that there are some major benefits to keeping bats around, so let's all do our part to help out them out. you can donate to bat conversation international to help fund research, you can get the word out about white-nose and the virtues of bats, or you can simply pledge to stay out of caves and properly sterilize all of your outdoor gear before visiting a new site. the disease has spread far enough. there is not enough time to wait for a cure. let's put a stop to it before the damage gets any worse.

Wednesday, April 11, 2012

welcome to science happens, and welcome to bat appreciation week!

why bats to kick off a blog about science? 

why not?! as a biology teacher, this blog will have some serious life-sciences bias, and as a major bat lover, expect to see our furry, winged friends showing up from time to time. bats are one of my favorite animals to talk about because, obviously, i think they're the best, and people often have misconceptions about them. some people are so freaked out by their tiny, wrinkled (and, might i add, adorable) faces and nocturnal lifestyle that they think they must be up to something. well, they are up to something, but it isn't trying to attack you, get in your hair, give you rabies, or drink your blood.

get ready for some bat education--here's what they're really up to:

1. eating mosquitoes. yep, that's right--people give bats a bad rap as rabies-spreaders, but when the Microchiroptera (small bats) head out for a meal, they're actually cutting down on the likelihood that you'll later be bitten by a mosquito. mosquitos are vectors for all kinds of nasty illnesses (west nile virus, anyone?), so bats are actually keeping you safe just by doing their batty thing.

2. eating other pests. in addition to cutting down on the mosquito population, many bats also consume pests that would decimate crops if left unchecked. like organic foods? then bats are your new bffs. bats are two-in-one natural pesticides and fertilizers (guano happens). there aren't many approved organic fertilizers or pesticides, and few are as cost-effective for farmers as a night-shift that works for free. lower costs for farmers means lower costs for you.

3. pollinating plants and distributing seeds. have you been known to enjoy the occasional margarita? how about a mango? then you should thank a bat. nectar-eating bats pick up pollen as they visit flowers for a snack, and then they transfer that pollen to other plants as they go about their business. megachiroptera (big bats) tend to be fruit eaters, and, like any good fruit eater, they end up consuming and then, ahem, releasing seeds in new areas.

4. providing inspiration for technology and medicine. sonar has been around for awhile, but our technology still hasn't caught up with what comes naturally to bats. studying how their brain processes sound can help us improve our own sonar systems. similarly, vampire bats produce a chemical in their saliva that prevents clotting. if you're going to go to the trouble of sneaking up on some unsuspecting livestock and taking a bite, you don't want the blood to clot before you're full. a blood clot floating around your blood stream can cause serious problems, especially if the blood clot ends up in your brain. this is what triggers a stroke, and a drug synthesized from the afore-mentioned anticoagulant in vampire bat spit can break up a clot incredibly quickly, limiting damage to the patient. vampire bats scary? i think not!

does everyone need to be a one-woman bat pride parade like me? no. but there have been (and still are) places where people feared bats so much that they attempted to destroy them all. 

it's ok if you'd prefer that bats do their thing as far away from you as possible, but they are beautiful and unique creatures worthy of our respect, and they make our lives better just by existing. 

they take a lot of heat for having the potential to spread disease, like in the movie 'contagion,' but getting rid of bats means losing the great advantages to humankind listed above. north american bats are particularly in trouble right now as the fungus responsible for white nose syndrome spreads and decimates entire populations of bats. if you would like to be sure that bats are around for the long haul, head over to my favorite bat website, bat conservation international, for ways to help.