Monday, January 31, 2011

Gateway Bacon

A couple of days ago NPR's Health Blog posted an interesting, and rather fun, story. The post was about bacon and vegetarians. Now, vegetarians are not normally known for their consumption of bacon, but you may be surprised at how many crave it and even eat it. Yep, bacon is the gateway food. In fact, I have a vegetarian friend who considers bacon a condiment and therefore considers it not breaking the vegetarian rules. I don't blame her. That sizzling, glistening goodness, that smell, not to mention that delicious taste. Am I drooling?

The bloggers over at NPR decided to find out what makes even the strictest vegetarians go all gaga over bacon. They decided to ask some scientists who study how food tantalizes the brain just what's up with the bacon-craves. One such scientist was Johan Lunstrom, who studies how the brain processes sensory information, like smell. Did you know that bacon is one- to two-thirds fat? True. It also has lots of protein. Because of that it likely speaks to our evolutionary quest for calories. That oh-so-yummy smell also contributes. Considering that 90% of what we taste is related to odor, it isn't all that surprising that bacon's strong and delightful smell hits our olfactory centers with a powerful "eat me" message. Additionally, odor is strongly connected to emotion and memory. All you have to do is think about a weekend breakfast and you'll likely include the taste and smell of bacon. The social aspect of said big breakfast also seems to be important and helps to solidify the memories. Add in to the mix the desire to try new and interesting bacon concoctions - like chocolate-covered bacon - and you've got a vegetarian on the edge! Bacon has also gained all kinds of status in foodie circles. This status adds a whole new layer of enticement to vegetarians. Forbidden

Here's the NPR Story:

Fun Bacon Links:
The bacon explosion! I've actually tried this one:

TurBacon Epic!

Fungi Phylum Fun

I love great, musical biology projects. Fungi!

Cry Me a River

I'm a little behind on this story. Not reading it but posting it. This one is all about tears and their effect on people. When you are near someone who is crying how does it make you feel? We know that seeing tears has an effect on people but is there something more to it than that? Is there a chemical component as well? After all, tears are glandular secretions.

Emotional tearing is a distinctly human behavior. Evolutionarily speaking, tears started out as an emotion-relevant function before turning into an emotion-signal alone. Charles Darwin suggested that one. If you think about it, it is a bit of a paradox. Tears serve as an emotional signal but do not serve an emotionally relevant function. Now keep in mind that, for the purposes of this article, we are not talking about tears as an adaptation to protect the eye or a mechanism to expel toxic substances. The authors of this study are looking for the functional significance of emotional tears.

Tears are produced by the lacrimal, accessory lacrimal, and Meibomian glands. The cornea (the transparent front part of the eye) is covered by a pre-corneal tear film which is replenished during blinking. This film creates a smooth surface, keeps the eye moist, helps supply oxygen to the eye, contains enzymes that prevent bacterial infections, and generally flush out the eye. The film is composed of three layers: oil (lipid), water (lacrimal or aqueous), and mucous (mucoid or mucin). The Meibomian glands (which line the edge of the eyelids) produce the oil, the lacrimal gland (lies underneath the outer orbital rim bone, just below the eyebrow) produces the water, and goblet cells in the conjunctiva produce the mucous. The lacrimal gland is the major producer of tears when a person cries.

It is known that the chemical makeup of human emotional tears differs from that of reflexive eye protective tears. The authors of this study took a closer look at some of those chemical differences, but not so much the actual components but their effects on the emotions/reactions of other people.

They had two female volunteers watch sad films in isolation and collected their tears. Separatately, they collected saline solution running down the same womens' cheeks to control for any skin-bound odor sources. In a blind test they presented the tears to 24 men to test whether they could smell a difference between the fresh tears and the saline. Next, they asked whether sniffing such odorless tears influences perception in order to see if tears contain a chemosignal related to a sadness context or if tears signal information related to sociosexual behavior. So they asked the male volunteers to again sniff a jar containing a compound (the tears or the saline), rate the intensity, pleasantness, and familiarity of the compound, and then with a pad of the compound stuck under their nose to rate the sadness and sexual attractiveness of a series of female subjects shown in a collection of photographs and answer questions that assess empathy.

The researchers found that tears did not differ from saline in perceived intensity, pleasantness, or familiarity - basically, they were odorless. They did not find a significant result in the ratings of sadness with tears. They did find that the ratings of faces differed after sniffing the tears or saline. A shift in the sexual attractiveness attributed to faces was observed. The men rated faces as less sexually attractive after sniffing the tears versus sniffing the saline. This result prompted the researchers to do another study. Perhaps the tears failed to influence sadness/empathy because the experimental context was not sad, and this was their chance to look at several other factors that influence these reactions.

The same procedure was followed for tear gathering. They tested 50 male volunteers using a paradigm that generates negative emotions. They measured psychophysiological arousal (galvanic skin response, heart rate, respiration rate, and skin temperature), self-ratings of mood, salivary levels of testosterone (before, during, and after sniffing the tears), and even did some brain imaging. Again, they found the tears to be perceived as odorless. The analysis showed that the men who sniffed the tears had a reduced self-rating of sexual arousal after a sad film, but this was only a moderate effect. The psychophysiology and hormonal responses, however, were pronounced. Several of the above listed arousal responses increased while sniffing the tears only to decrease dramatically afterwards. The men were also found to have lower testosterone levels following tear exposure, a significant indicator of reductions in sexual arousal in men. The brain scans showed that, in areas associated with sexual arousal, brain activity was lower after sniffing tears than after watching a sad movie.

All of these results together suggest that there is a chemosignal in women's emotional tears that reduces sexual arousal in men. When you consider that exposure to tears is, in many cases, in close proximity, at least in Western culture, it is not so difficult to believe. Just look at the act of comforting a crying loved one. In a hug you place your nose near a teary cheek and so will inhale some of these chemosignals. It is not usual for mammals, including humans, to use these signals, this is just the first study to show it.

Here's the paper:

Gelstein, Shani, et al. Human Tears Contain a Chemosignal. Science: 331 (6014), 226-230. (DOI: 10.1126/science.1198331)

And here are a couple of story links (although, this was picked up by a lot of news outlets so all you have to do is Google it to find more):

Thursday, January 20, 2011

Rapping ATP

I featured these guys in my "Rappin' Science" post back in April rapping about gene regulation and oxidation. Here is another one of their videos, this one about making ATP.

Monday, January 17, 2011

Tiger Tales

Tigers are the largest of the Asian big cats. There are currently 8 recognized subspecies of tiger (Panthera tigris):

1. Amur (Siberian) tigers (Panthera tigris altaica)
2. Bengal (Indian) tigers (Panthera tigris tigrisn)
3. Indochinese tigers (Panthera tigris corbetti)
4. South China tigers (Panthera tigris amoyensis)
5. Sumatran tigers (Panthera tigris sumatrae)
6. Bali tigers (Panthera tigris balica)
7. Javan tigers (Panthera tigris sondaica)
8. Caspian tigers (Panthera tigris virgata)

In the past tigers ranged across Asia, northern Iran, Afghanistan, Thailand, Vietnam, Laos, Cambodia, Malaysia, parts of Pakistan, and the islands of Bali and Java. These days tigers are not so common and wide ranging. In fact, they are extinct in most of these areas with the Caspian, Bali, and Javan tigers completely gone. Some populations are more stable than others, but the remaining subspecies are in danger due to the illegal wildlife trade, poaching, and conflict with people.

Here, I'm going to focus on the Bengal Tiger (Panthera tigris tigris) which are found mostly in India. Since 2008 the Bengal Tiger has been listed by the IUCN (International Union for Conservation of Nature) as Endangered. India has recently revamped its national tiger census methodology to include more updated and scientific methods. They are now using camera trap and sign surveys using GIS to extrapolate site-specific tiger densities. The results of this work (which includes some areas outside of India) has estimated the current tiger population of India at 1,411 adult/sub-adult tigers. Now, when it comes to conserving the genetic diversity of tigers, biologists like to quantify the breeding population (the number of animals raising offspring to reproductive adulthood). The breeding population of Bengal Tigers has been estimated at just 40% of the adult population. Why such a small number? Likely it is due to the small ranges which are not large enough to support an effective population, and those ranges are still shrinking.

There are all sorts of tiger conservation groups out there. They are all very interesting and most very worthy of donating to, but today I'm going to talk about some interesting programs at colleges and universities. There are a few American universities that have the tiger as their school mascot: The University of Missouri, Clemson University, and Auburn University. To save the animal that is also their mascot they have each created organizations to help educate themselves and others about this endangered animal. Recently, these schools have also joined forces with WWF (World Wildlife Fund) and its work in protecting the tiger. WWF has given these schools the challenge of raising $75,000 to help end the illegal tiger trade in China and the Eastern Himalayas. As of today $7,446 has been raised, with Auburn University in the lead.

Let's take a quick look at the goals of these individual groups, and I'll give you the links to their websites so you can learn more about them and possibly help them out.

University of Missouri:

In 1998 an Michael Baltz, a PhD student in biological sciences, wrote an editorial for the Columbia Daily Tribune where he suggested that students could take the lead in implementing a program that would support the conservation of their mascot. Soon after, in 1999, Mizzou Tigers for Tigers was organized. It was the nation's first tiger mascot conservation program. Here, faculty, staff, students, and alumni work together to conserve wild tigers. This organization works to raise awareness about the endangered status of tigers by working with local schools and educating students about conservation on a global scale. They bring in experts in the field to present public lectures on tigers and tiger conservation, and they also work to raise funds to aid in conservation efforts.

Goals: Raise awareness about the conservation status of wild tigers, fund projects benefiting wild tigers and people living near tigers, and enhancing educational and research opportunities for the university's students while contributing to tiger conservation.

University of Missouri Tigers for Tigers Homepage:
This organization works closely with the Save the Tiger Fund:

Clemson University:

A Clemson student returning from a trip to India decided to start a student organization to help wild tiger conservation efforts. This was the beginning for Clemson Tigers for Tigers. The organization struggled its first few years but grew to become a special topics class within the Biological Sciences department, bringing in experts to speak, volunteering at the Central Florida Animal Reserve, and even takes students to India to tour and learn about various tiger conservation initiatives. The club includes a "Cubs for Cubs" program that teaches local school-aged children about wild tigers, the "Adopt-a-Park" program which is leading towards sponsoring a tiger reserve in India, and, of course, fundraising.

Goals: Increase awareness and interest in tiger-range countries and enhance Clemson's reputation for social responsibility and public service.

Clemson Tigers for Tigers Homepage:
An article in Clemson's school paper The Tiger:
This organization works closely with the Tiger Trust:

Auburn University:

Auburn also has a Tigers for Tigers organization. It is part of their chapter of The Society of Conservation Biology. Members of the organization work with local outreach programs and the Montgomery Zoo to provide activities for their various educational programs. They are trained by and work with Project WILD, one of the most widely-used conservation and environmental education programs among educators of students kindergarten through high school. They use the tiger to teach students about conservation on a global scale and use these themes to education students on conservation closer to home.

Goals: Raising funds for the conservation of wild tigers, becoming a partner in a nationwide Tigers for Tigers program, and educating on conservation in Auburn schools.

Auburn Tigers for Tigers Homepage:

You would like to help? Easy. You can visit WWF's page highlighting the Tigers for Tigers challenge and find links to donate to each school's fund here:

I also recommend visiting the Tiger Trust and the Save the Tiger Fund websites I linked to above. Additionally, you can donate $10 to WWF's tiger conservation fund by texting TIGERS to 20222.

(image from

Wednesday, January 12, 2011

Water Sculpture

I suppose this video is more art than science but as it is water related, and water is chemistry, then I'm going to count it as science too. Enjoy!

Water Sculpture from Shinichi Maruyama on Vimeo.

Wednesday, January 5, 2011

Survival of the Fittest

In 1980 Calvin Klein Jeans came out with a commercial featuring Brooke Shields and a unique take on jeans...I mean genes...

Saturday, January 1, 2011

Bad Movie Physics Report Card

Movies. I love them. I'm not sure if I would call myself a film connoisseur but I just may be on the road to full-fledged film geek. I often find myself enjoying the bad ones almost as much as the good ones, particularly those with some oh-so-wrong science: man-eating anaconda in Antarctica, extant giant dinosaur crocodiles, men turning into mosquitoes. Basically, any SyFy original movie you can think of. What does grate though are serious, mainstream films about a scientific subject (or one that just has a lot of science in it) that just plain get the science wrong. Movies that clearly have a budget for, or even hired a, science advisor and then ignored it. Ignoring science that, had it been correct, would not have detracted from the plot. My all-time favorite bad science movie line: "That looks like human DNA!" from Mission to Mars. *facepalm*

Anyway, that's my mini-rant. A rant that is related to the subject matter for today's post.

IO9 has posted a Bad Movie Physics Report Card where they rated 18 movies based on how many laws of physics they broke. We all know that space movies bend, if not outright mangle, the rules of physics just to travel around in their chosen media. After all, a light year does, in fact, take a year to complete, and who wants to watch that? For the most part, the categories that IO9 used are pretty self explanatory but they expanded on them a bit anyway:
  • There's no sound in space
  • Not all planets have Earth gravity
  • Planets should have diverse climates, instead of one unified climate across a "desert planet" or "forest planet"
  • It shouldn't be too easy to communicate with alien creatures, without some kind of high-technology "translator" explanation
  • And it definitely shouldn't be too easy for humans to interbreed with aliens
  • Humans exposed to vacuum without a spacesuit shouldn't explode or shatter. And a "hull breach" where the ship's crew is exposed to vacuum should kill everyone instantly
  • You can't have fires in space, unless there's oxygen leaking out somehow
  • Asteroids or other objects shouldn't be able to float close together without falling into each other's gravity
  • People shouldn't be able to dodge lasers or other speed-of-light weapons
  • And there's no reason why someone would move in slow-motion in zero gravity
  • Faster-than-light travel is probably not ever going to be possible
Here's IO9's infographic (click to enlarge):

This is the article:
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