----------------------

Tuesday, March 23, 2010

We're Moving!!

Hello Everyone!

I have been invited move Observations of a Nerd to Science Blogs, an opportunity I simply could not pass up. As such, this blog will be moving. This site will remain as an archive and in case I ever decide to leave, but for the forseeable future, Observations of a Nerd will be found at http://scienceblogs.com/observations.

The new feed is: here , so please update your subscriptions. I hope that all of you will continue to follow this blog and will join me over at Science Blogs! 

Aloha,
Christie

Monday, March 15, 2010

Picky Octopuses Don't Settle For Less Than The Best HDTV

ResearchBlogging.orgOctopuses* and their cephalopod relatives are some of the smartest animals on the planet. Accordingly, many scientists want to understand how their mind works. To gain insights into the complex minds of cephalopods, researchers have been studying behavior in individual animals for years by presenting different animals with various visual stimuli. But many of the methods have downsides - for example, if you want to see how an octopus reacts to another octopus, you can add an octopus to the tank, but doing so introduces other variables. There may be variation in response based on how the introduced octopus looks, moves, etc, and these factors are hard to control. Ideally, you'd want something that you could repeat exactly every time - like a movie.

When researchers have tried in the past to use movies to stimulate behavioral responses, however, they found that the octopuses didn't respond. They weren't sure exactly why. Mirrors and pictures revealed that octopuses can clearly see the 2-D images, so that's not the issue. It was as if they just weren't interested in videos.

Dr. Renata Pronk and her colleagues from Macquarie University had a theory - they thought that the octopuses didn't believe them. Cephalopods rely heavily on their sight, and their vision is highly developed, so it's possible that the animals easily realized that poor quality videos weren't real life. If this were the case, Pronk realized, octpuses might respond to the breakthrough visuals of HDTV.

To test this hypothesis, she collected wild gloomy octopuses (Octopus tetricus) and subjected them to high-definition videos of things that might interest an octopus - a tasty crab, another octopus, or a jar to play with.

Incredibly, when she played the first video of a crab for her first test octopus, it grabbed at the screen. HDTV fooled it! Heres a video of a thoroughly-tricked octopus c/o New Scientist:


With their method working, the researchers tested 31 octopuses on 3 different days over a ten-day period to see if their behaviors varied temporally. Furthermore, they compared the individual animals, to look for evidence of personalities.

Behavioral biologists define a "personality" as behavioral differences between individuals that are consistent over time and across ecologically important contexts. In other words, Pronk wanted to know if some octopuses are consistently more aggressive or passive than others when exposed to the same situation.

The researchers found that the octopuses did react differently from each other, but they also reacted differently on different days. Some days they were highly reactive, other days they were less so. There was no consistent reaction from a given octopus.

These data suggest that octopuses have what is called "episodic personalities." This means that they do show differences in behavior between individuals, but they also show differences over time. This isn't necessarily "bad" or suggest they are "less intelligent." Indeed, this may be a sign of their intellect - after all, humans exhibit individual and temporal variation in behavioral response, too.

Moreover, this study gives biologists a new method to study octopus behavior. Of course, the most important questions have yet to be answered - like which American Idol contestant the octopuses will root for, or whether they will detest Jersey Shore as much as I do.


*Not Octopi. I was very disappointed to learn that it's not Octopi.

Citation:
Pronk, R., Wilson, D., & Harcourt, R. (2010). Video playback demonstrates episodic personality in the gloomy octopus Journal of Experimental Biology, 213 (7), 1035-1041 DOI: 10.1242/jeb.040675

Monday, March 8, 2010

Duck to avoid parasites

ResearchBlogging.orgDuring the summer, strange formations can be found on some species of Goldenrod. The stems become enlarged and form a hardened golf-ball like object called a gall. Cut into this weird sphere and you'll quickly find what causes the plant to create such a strange object: the larvae of the Goldenrod Gall Fly.

The Goldenrod Gall Fly (Eurosta solidaginis) is a parasite which uses the Goldenrod for protection and nutrition for a whole year while it grows and pupates. When it does, it can seriously damage the Goldenrod, even prevent the plant from flowering and producing seeds. This is a serious blow to the plant, so the Goldenrod doesn't just take this kind of damage laying down. When the flies are flitting about searching for rods to lay their eggs in, the rods in turn try to avoid their pests in a very recognizable way: they duck.

Scientists had found that during the few weeks that adult flies spend mating and laying their eggs, some Goldenrod stems undergo an odd behavior: they stop growing upward and instead curl and grow downward, creating a "candy-cane" like stem (see L). Once the mating season is over, they straighten up again, just in time to flower and seed.It had been found that this odd downturn made the rods twice as resistant to the flies, but scientists weren't sure if it was the behavior causing this resistance or something intrinsic about those plants that made them resistant and turn down.

Luckily, they discovered that bent plants straighten when placed in the shade, and this gave them the unique and rare opportunity to investigate causation. Researchers took both straight and bending plants and place them in a greenhouse both in the sun and in the shade. As the shaded bent plants un-curled, they set Eurosta solidaginis upon the lot, and recorded which ones ended up parasitized.

The straight variety were parasitized heavily whether in the sun or the shade. But the 'ducking' plants completely avoided parasites - if they were still bent (see R). Those that began to straighten by being placed in the shade were parasitized just as much as the non-bending variety, strongly supporting the hypothesis that the bending behavior itself created the observed resistance to parasitism.

Moreover, the experiment explained why the ducking behavior works. Unlike when people duck, the plants did not cause the flies to miss. Indeed, female flies often landed on the bent stems. However, the researchers explained, the flies appeared confused or disoriented by the plant's behavior. It's possible they didn't recognize the bud where they usually lay because of its orientation, or interpreted the bend as a damaged or unhealthy plant that won't last long enough to nurture their young. For whatever reason, the female flies decided that the plant was not a good choice, and moved on to other plants instead of depositing eggs.

The researchers have yet to understand, though, why the bending behavior is relatively rare in Goldenrod populations. Their future research hopes to learn more about how this behavior occurs.

Wise, M., Abrahamson, W., & Cole, J. (2010). The role of nodding stems in the goldenrod-gall-fly interaction: A test of the "ducking" hypothesis American Journal of Botany, 97 (3), 525-529 DOI: 10.3732/ajb.0900227

Sunday, March 7, 2010

Weekly Dose of Cute: World's Biggest Bunny!

Often, the cutest things come in small packages. Not so with Ralph - at 42 lbs, he's a record-breaking rabbit.

Ralph comes from a huge family - both his mother and father previously held the world records for largest rabbit in length and weight. And though he's already the biggest bunny in the world, Ralph is still growing! No one knows how immense this ball off fluff will get, but however big he ends up being, he's sure to still be 100% adorable.

Friday, March 5, 2010

Link Love, etc

First off, the e-mails have been sent, and if you're a member of ResearchBlogging.Org, then you should haev a vote to cast in the ResearchBlogging Awards! So go vote for Observations of a Nerd for the best lay-level and biology blog as well as best research post of the year *cough* *cough* your favorites!

If you aren't a member, then I guess you'll just have to wait to see what happens. Good luck to all the contestants!

Anyhow, I've been awful busy this week starting my last rotation in a whole new lab, so I've been lagging on the goods. If you follow my twitter, you've gotten a little more, but for everyone else here are some fun things to go check out:

Carl wants to give in to the microbes - what do you think?

A little warm and fuzzy after that: A dog and his feline best friend

Need something to do? How about you take your peeps places!

And of course, the most important question you'll get asked all day: Do your balls hang low?

Hopefully that'll keep y'all busy until I can force myself to sit down in front of the computer a little longer and give you a real post.

(and, PS, if you're still bored, scroll down a little and check out the "Fun Reads" and "Other Fun Reads" sticky notes on the right-hand side of the page...)

Tuesday, March 2, 2010

Bejeweling bugs to inspire bioadhesives?

ResearchBlogging.orgRemember those perhaps gross but cool insect jewelry artists I mentioned before? Now, their incredible tube-making skill might be used in an entirely different field: medicine.

Dr. Russell Stewart, an assistant professor at the University of Utah, has been studying natural adhesives for years. He was drawn to the caddisfly because it's one of the few creatures in this world to have accomplished a very difficult feat: it sticks things together underwater.

Creating an adhesive that works when wet isn't easy - just think of what happens to your average band-aid in the shower. But the caddisfly has mastered underwater engineering, and Stewart wanted to know exactly how it sticks together its living quarters.

Like many other organisms including spiders and silkworms, caddisfly larvae spin silk. It's their silken strands that stitch together their makeshift mobile homes. But scientists didn't understand how this worked while underwater - until now. A new study published online first in the journal Biomacromolecules reveals the caddisfly's architectural secrets.

The caddisfly larvae uses its silk like tape, researchers explain. They took larvae and placed them in aquaria with glass beads. Once the bugs had created their homes, the researchers analyzed their homes with a wide variety of technical tools, including scanning electron microscopy. The SEM images on the right show the criss-crossed strands of silk that have woven together the beads into the larvae's tube.

They learned that unlike the silk produced by terrestrial creatures, the caddisfly's silk works underwater because it's covered in phosphates (blue color in image F). Up to 95% of the serine residues in the silk protein are phosphorylated! We use phosphates in our own adhesives, including fillings and latex paints. In the caddisfly, these negatively-charged groups line up with positively charged proteins and cations like calcium, and the strong attraction between them holds the fiber together.

What's so special about this adhesive is that it can be used on just about anything, as artist Hubert Duprat found out when he placed caddisfly larvae in aquaria with gold flakes and precious gems. Their silk can bind all kinds of things, and this unique trait may make it an ideal candidate for medical use.

The hope is that since caddisfly silk works when wet, it could inspire a new kind of way to suture surgical wounds or even help repair small bone breaks. Characterizing the silk fibers is the first step towards copying the caddisfly's technology and creating a new line of medical glues or tapes that one day may replace sutures or stitches in sealing up wounds.

Stewart, R., & Wang, C. (2010). Adaptation of Caddisfly Larval Silks to Aquatic Habitats by Phosphorylation of H-Fibroin Serines Biomacromolecules DOI: 10.1021/bm901426d

Sunday, February 28, 2010

There's always a biological excuse...

ResearchBlogging.orgIt's almost a given that, during any discussion about male infidelity, someone will throw out some variation of "men are biologically programmed to spread their seed."

Why is there this theory that men are more driven to cheat? Part of it has to do with the size of their gametes. If bigger is better, then men are pathetic, for their little sperm are 1/100th the size of a woman's egg. Because women have such a greater investment in each offspring right from the get-go, the assumption is that women are pickier when it comes to who they allow to fertilize their eggs. Men, since it doesn't cost them much anyway, are better off getting as many women to agree to let them fertilize. In mammals (like us), this difference in investment is further exacerbated by long, internal pregnancies and lactation, which place even more of the burden on the mother. It just makes so much sense - it's clear, simple, and like most biological explanations that are clear and simple, it's nowhere near the whole story.

Even still, we've internalized this supposed biological explanation so much so that it's almost an excuse. In an article about why men cheat, for example, it's carefully explained that "The biological urge to mate with many different partners is stronger in men than it is in women" and that "males mate with multiple females to ensure the survival of the species." Well, I guess if it's to ensure the survival of the species...

Perhaps, then, my female readers will appreciate a new study published in Current Biology which suggests that it's the women whose infidelity is important in ensuring species survival. Indeed, as they explain, females having multiple male partners may be vital in preventing extinction!

Ever since the "spreading the seed" explanation for why males are so sexually liberal was proposed, there have been a few issues with it. The most glaring one was that in many animals, women, too, have multiple partners. Some species seem to have the roles reversed, where women are dominant and have harems of male suitors. Even in species that seemed monogomous, it turned out the women were cheating - in many species of monogomous birds, for example, females actively seek "extra-pair copulations" (ornithologist speak for affairs), and up to 75% of the chicks were being raised by males that were not their dad!

Biologists began to realize that women, too, can benefit from sneaking around. In monogamous species, a female is stuck with whatever guy she gets to raise her young, even if isn't the biggest or the brightest. It's a shame, to her, that she can't have better babies, for surely her lackluster hubby's offspring will be less than ideal. Cheating, it was believed, gave a woman the best of both worlds. She gets to have a dedicated, loyal sub-par male take care of her young, but the young are born from better stock that she secured on the side.

The problem is, nothing explained polyandry - a mating system where women have multiple "husbands" or partners. Considering that there is a higher biological cost to the female to mate, why would she ever want to have a permanent array of suitors demanding her attention? It seemed like there was something missing. Biologists Tom Price, Greg Hurst, and Nina Wedell believed there was more to the story.

It turns out that the bigger picture may be genetic. Mutations in chromosomes can lead to what is called sex ratio distortion. There are certain alterations that, for whatever reason, cause the sperm containing either the X (female) or Y (male) chromosome to fail to fertilize. They are termed Sex-Ratio Distorter Genes or Chromosomes (SR genes or chromosomes) because they alter the balance of males to females in a population. Because mutations are constantly occurring, there is always a risk that all-male or all-female broods will be born, the result of which is potential extinction of a population or a species, if the altered gene becomes widespread.

The team hypothesized that female promiscuity may help protect against SR chromosomes that develop in males. They tested their hypothesis using a known SR chromosome in the the fruitfly Drosophila pseudoobscura. This particular mutation, when carried by a male, causes all of his sperm that carry a Y chromosome to die before they can fertilize, though it has no clear effect on eggs when carried by females. Because it doesn't detriment female gametes, this kind of mutation can persist and spread until, eventually, not enough males are being produced to maintain a population.

They created populations of fruitflies where 30% of the flies carried the SR mutation. They then had one population breed freely, where females mated with a number of males, while in the other, females were restricted to a male apiece. They bred these populations for several generations to see if there were any differences between the two.

In just fifteen generations, almost half of the monogamous populations became extinct because there weren't enough men around. Meanwhile, none of the populations with the promiscuous girls died out. In the monogamous populations that survived, the SR chromosome was far more prevalent than in the polyandrous ones.

Why did those populations fare so much better? It's likely the effect of sperm competition. When a female mates with many males, each of their sperm is vying to fertilize her eggs. Since the SR males produce half the sperm that normal males do, they've got an instant disadvantage in a system where they have to compete, meaning the damaging chromosome is less likely to spread.

This study is the first to suggest that a polyandrous mating system could have evolved as a means to protect against sex-ratio distortion-induced extinction. Of course, extrapolating these results to other species is more difficult, so it's impossible to say that this study has any grand relevance to humans. It does, however, plant the seed of possibility that female promiscuity is healthy and vital in a population.

So boys, next time I hear you say that men are dogs because it's 'biological', expect to hear a lecture about how girls can sleep with whomever they want because it will save the species. Jus' sayin'.

Price, T., Hurst, G., & Wedell, N. (2010). Polyandry Prevents Extinction Current Biology DOI: 10.1016/j.cub.2010.01.050

Saturday, February 27, 2010

How Twitter Made Me Into A Citizen Journalist

I awoke this morning at 5:50 am because of a nightmare, only to hop online and find out another one had occurred in Chile. An 8.8 magnitude earthquake had struck. Ten minutes later, the first tsunami warning siren sounded.

It was deafening.

I remember when I was a little kid growing up in Hawaii Kai, there was a tsunami warning. In the end the water only raised by a few inches. In the past few months since I'd started my PhD, there have been a couple other tsunami watches, none of which resulted in anything of interest. But there's something about a haunting siren at 6 am that makes you take something seriously, and not wanting to be left in the dark, Barry and I immediately began closely watching the news. At about 6 am I (@NerdyChristie) tweeted my first tweet of the day: "Ah fuck. Serious tsunami warning. Not cool."

Immediately friends and blog followers began pouring in their support and good wishes, and asking for me to "keep them updated." So I did. I started tweeting the interesting anecdotes from the news, retweeting other information posted on the tsunami, and adding in what was going on around me as I headed to get extra water and prepared for the worst.

I'm not really sure what caught everyone's attention, but suddenly, I started getting followers. I started getting A LOT of followers. Within an hour or so, I had another 200 people tuning into my twitter feed, and every minute more followers tuned in.

Somehow, I had crossed a line; I had become a citizen journalist.

Why did so many people find my updates so interesting? I think it was because I cared. I cared about getting it all. I cared about being quick. But more importantly, I cared about being accurate. And apparently, the major news outlets didn't.

It was amazing to me how much the major networks - Fox, CNN, MSNBC - got wrong. Simple things, like locations, were just annoying. But they got large things wrong, too - Fox reported waters receding 15 feet from Waikiki before Hilo had even been hit. None of them seemed to have anyone who actually knew what was going on.

That's not to say that there weren't news programs that had accurate and up to date information: there were. The local news network, KGMB/KHNL and the local papers did a great job. What was most interesting to me, though, was what they had in common - they were all actively incorporating Twitter into their news.

Today really revealed to me how Twitter has revolutionized modern journalism. The Honolulu Advertiser (@honadv), the Star Bulletin (@starbulletin) and the major news network (@hawaiinewsnow) were live tweeting tsunami updates.

These media outlets weren't just putting out updates via twitter - they were taking them in. The Honolulu Advertiser had up a twitstream of the hashtag "#hawaiitsunami" on their homepage. Hawaii News Now constantly provided viewers with updates of different areas sent to them by twitterers, and I learned as much about what was going on watching twitter feeds as I did watching the news.

It was truly incredible was how much information was being gathered by nobodies like me, people just sharing their personal experiences on the web. And in turn, those that looked to twitter and social networking to stay informed got accurate, real-time information, while those who looked to CNN and Fox got much, much less.

Should it be shocking that someone following my feed got more information and better information than someone watching TV? Maybe not. Because of twitter, I was able to synthesize and pass along information from a variety of sources instantly. Instead of being one journalist talking to one person, I was every journalist in Hawaii that was talking to every person. I was every live camera and every online update that was out there. In essence, I had every TV channel, every newspaper, and every person tweeting in Hawaii working for me, gathering information that I then passed along. This kind of journalism has never been possible before, though it's clear why it is perfect for a disaster-type scenario. Journalism has been forever changed by twitter, and I suspect that feeds like mine was today will become more and more popular as sources for accurate, up to date information about breaking news.

In the end, the tsunami definitely came, causing water level fluctuations of up to 10 feet in Hilo. Here on Oahu, the effects were smaller, though we still got to see our share of the water rushing in and out. The ocean will still be acting unpredictably for the next day or two, but, thanks to the on-target predictions by scientists and effective prevention measures by the local officials, the worst has passed and no damage has been reported from anywhere in Hawaii. As for me, I'm off to get some much needed rest after tweeting constantly for seven hours straight.