Tuesday, August 21, 2012

daddy swagger

The Berkeleyside news site highlighted a new music video today (below) by DJ Dave (David Wittman (creator of the “Whole Foods Parking Lot” video, and the “Berkeley Enough” video).  David Wittman's company is called Fog and Smog a "creative collective of culture vultures from the SF Bay Area and Los Angeles."  Check out their YouTube channel - great, funny stuff!

This video reminds me of another hip hop parenting video, Swagger Wagon, strangely enough by Toyota, featuring the "Sierra parents" to promote the coolness of the Toyota Sierra minivan.

This "genre" of mommy/daddy rap is new to me, but it makes sense.  The history of hip hop music tells us that "hip-hop's roots can be found in a variety of African-influenced musical styles... gospel, folk, blues, jazz and R&B music ... calypso, salsa, soca, ska, reggae and other Afro-Caribbean styles."  Kool Herc (Clive Campbell) and Grandmaster Flash (Joseph Saddler) were among the first DJs to use turn-tabling in the 1970s and early 1980s.  Then, in the 1980s, "modern" hip hop really took off, with artists like  Run–D.M.C., Public Enemy, and the Beastie Boys.  Later, in the early 1990s,  gangsta rap took hold - artists like Dr. Dre and Snoop (Doggy) Dogg.

So, if you were a slightly dorky teenager in the late 1980s, hip hop was cool. You may have spent your college years listening to 2 Live Crew, Biz Markie, DJ Jazzy Jeff & The Fresh Prince and Naughty by Nature.  Now, almost 25 years later, you would be nearing 40 and likely a parent with young kids.  Hence mommy / daddy rap has found their market!

Fitting this age demographic myself, I must say I find both videos hilarious.

Sunday, August 19, 2012

bike parkour ?!

DISCLAIMER TO MY STUDENTS:  I am in NO WAY endorsing this activity, or encouraging you to try it.  I just think it's one of the craziest things I've ever seen, and I encourage you to WATCH and not DO this.

Well, I expend enough vigilant energy biking up the SF hills and down Market St. during commute hours, but these guys take urban biking to a level I never knew existed.

The trial-rider best known for his "bike parkour" skill is 26 year old Danny MacAskill from Scotland (visit his webpage).  You can read a Twitter-esque interview with MacAskill here. His two most-viewed videos on YouTube are: Inspired Bicycles - Danny MacAskill April 2009 video (30 million views) and his more recent video Danny MacAskill - "Way Back Home" (21 million views).  The "Way Back Home" video is embedded here:

One of the newer guys on the block is Andrew Dickey from Melbourne, Australia.

Dickey made an earlier video, called Art of Bike, where he takes the viewer on "a bicycle tour of Melbourne's cultural icons."  It's pretty cool.

I guess, technically, what these guys do is not called "bike parkour."  In reality, it is a sport considered "bike trials," started in 1980.
CC-BY-SA by S. Bennett
Bike trials is an individual sport that incorporates the use of a special bicycle which the rider must maneuver and balance on in order to complete specially designed artificial or natural "sections." The objective is to pass through the sections with as little physical contact with the ground as possible, hence obtaining minimum penalty points.

Bike Trials comes from Motorcycle Trials. Motorcycle trials riders wanted to give their kids something to practice on before moving up to motorcycles, and some of the kids grew up to love bike trials more.

Of course, my question is, don't these guys break their bones all the time?  According to a Men's Health interview with Danny MacAskill, the worst injury he sustained was breaking his collarbone three times in a row in 6 months.  Other than that he "tries not to injure [him]self."!  (ouch)

Finally, MacAskill recommends "Some good tricks to start off with include the manual, track stand, wheelie, skid, stoppie and bunny hop. "

No thanks, I think I'll just watch.

Sunday, August 12, 2012

bioluminescent dinoflagellates (or awesome glowing water!)

I got to play with bioluminescence this weekend!  Some friends invited me out on a short kayak trip and we able to experience the magical glowing water firsthand!  But, of course, it wasn't magic... it was science!

Bioluminescence is the production and emission of light by a living organism.  The name comes from the Greek word bios for “living” and the Latin word lumen for “light.”  So, put it together and you have “living lights"!  Animals most often use bioluminescence to communicate with each other, to find mates, to catch prey or to defend themselves.  You may be most familiar with bioluminescence from fireflies - though other organisms can produce it, including squid, deep-sea fish, some bacteria and even mushrooms!  However, dinoflagellates (single-celled protists) are the most common source of bioluminescence.

I've heard about this phenomenon in Puerto Rico.  On the southern shore of the island of Isla de Vieques, there is a bay called Puerto Mosquito (Mosquito Bay).  Apparently, this bioluminescent bay has been officially declared the brightest recorded in the world by Guinness Book of World Records 2008.  Check out this video - the part about the glowing water is 1:38 -  2:12, though the rest of the video has some INCREDIBLE footage of a cuttlefish. (This particular dinoflagellate is Pyrodinium bahamense.)

There is also some incredible footage of luminescent algae (dinoflagellate) blooms in Southern California, where the waves appear to glow!  (This particular dinoflagellate is Lingulodinium polyedrum)

I have also had the opportunity to see some bioluminescent organisms at the Marin Headlands - Noctiluca scintillans in the sand!

But little did I know this also occurred right here in northern California in Tomales Bay!  According to the Blue Waters Kayaking site, "bluish flickers are visible in the water column, which come from blooms of bioluminescent "dinoflagellates". These tiny creatures emit short flashes of light when disturbed, and at certain times of the year put on quite a show for kayakers. Schools of fish in the bay create a phosphorescent trail which can look like a glowing cloud in the water. Seals chasing the fish may create a phosphorescent event which can be very exciting to watch. … All this glowing activity is only visible at night when the sun and moon are both down. In 2012, this will be the case on the days July 21, July 28, August 11, August 18, August 25, September 8, September 15, September 22, October 6, October 13, October 20 from sunset until the moon rises."  (You should go!)

In the daylight, we saw pelicans, sea jellies, seals, and even a bat ray!  By 9:30 pm, the light show had begun.  Along the edges, where the water met the sand, you could see little glowing spots.  Once we pushed off in the kayaks, we could see an eerie glow emanating from the bow of each boats as it moved through the water.  Paddling created swirling, glowing eddies.  Fish, as stated above, made themselves known by the glowing streaks they left in the wave of their movements.  And, perhaps most fun of all, dangling your fingers over the edge of the boat created all sorts of glowing patterns... splashing made a liquid fireworks display!

Why only those dates?

According to the Vieques site, the best time to observe the bioluminesence aligns with particular phases of the moon, between full and new moon, to be exact.  Other sites are more vague, for example, "bioluminescence is only present for a couple of months a year when the variables all align: water temperature, air temperature, winds, currents, and tides."

However, the moon phase connection makes sense.  You want it to be very dark with little to no moonlight.  Yesterday, on August 11, the Moon rose at 12:57 am and set at 3:47 pm, leaving our ideal viewing time (around 9 - 10 pm) without any moonlight.  The Moon's phase was waning crescent, partway between a 3rd quarter (moon rise at midnight, moonset at noon) and new moon (moonrise at sunrise, moonset at sunset).

My roommate and I also discussed the fact that it may have to do with the wind.  She says it is much foggier lately because of the cold upwelling (read more if you are interested).  This same upwelling brings nutrients to the surface, providing good conditions for dinoflagellate population growth.  And according to this sobering article about the effect of climate change on coastal ecosystems, the most intensive upwelling occurs in Tomales Bay during the summer, "in response to strong, often persistent northwesterly winds."  This also aligns with the dates the bioluminescence is best viewed.

What's making all the glow?

Dinoflagellates are single celled protists; with some animal characteristics like locomotion and some plant characteristics such as photosynthesis. According to Wikipedia, more than 18 genera of dinoflagellates are bioluminescent and the phylum containing dinoflagellates is termed Pyrrophyta, meaning "fireplant"!  (The following list of facts comes directly from the Dinoflagellates and Red Tides page from the Latz Laboratory at the Scripps Institution of Oceanography - if you want to learn more, those pages contain a wealth of information!)
  • Dinoflagellates are planktonic - 90% of all dinoflagellates are marine plankton.
  • Dinoflagellates are small. - many of them are microscopic and range from 15 to 40 microns in size, the largest, Noctiluca, may be as large as 2 mm in diameter!
  • Dinoflagellates are motile - dinoflagellates swim by means of two flagella… as a result of the action of the two flagella the cell spirals as it moves.
  • Some dinoflagellates are photosynthetic, some are heterotrophic
    • Many dinoflagellates are photosynthetic, manufacturing their own food using the energy from sunlight, and providing a food source for other organisms. The photosynthetic dinoflagellates are important primary producers in coastal waters.
    • Some photosynthetic dinoflagellates are symbiotic, living in the cells of their hosts, such as corals. Called zooxanthellae, they are found in many marine invertebrates, including sponges, corals, jellyfish, and flatworms, as well as within protists, such as ciliates, foraminiferans, and colonial radiolarians.
    • Approximately half of all species are heterotrophic, eating other plankton, and sometimes each other, by snaring or stinging their prey. Non-photosynthetic species of dinoflagellates feed on diatoms or other protists (including other dinoflagellates); Noctiluca is large enough to eat zooplankton and fish eggs. Some species are parasites on algae, zooplankton, fish or other organisms.
  • Dinoflagellates usually reproduce asexually - the most form of reproduction is asexual, where daughter cells form by simple mitosis and division of the cell. The daughter cells will be genetically identical to that of the original cell. 

Why do they do it?

The most common trigger for dinoflagellates glow is mechanical stimulation, like the disturbance of a boat, paddle, swimmer, fish, or our fingers!  Apparently, they can react to chemical stimulation as well - reducing the pH of their environment can cause some dinoflagellates to glow continuously (source).

The most common theory on why these organisms bioluminescence is that the reaction acts as a type of "burglar alarm" defense mechanism.  When the dinoflagellate is disturbed, it is likely it is going to get eaten (most often by a shrimp).  So it sends out a brief flash, which may distract the predator, or attract a secondary predator that might eat the predator that is trying to eat the dinoflagellate.  Or, perhaps the dinoflagellate will get eaten anyway, but by attracting a secondary predator to eat the first predator, the dinoflagellate is saving the rest of its protist buddies from being eaten.

How do they do it?

SHORT STORY: There basically needs to be a chemical mix of a luciferin (a "light-producing substance") and a luciferase (an enzyme that helps the interaction among luciferin, oxygen and water) to produce a new substance that emits light.  When a dinoflagellate is disturbed, these substances are mixed in the cell and emit light.  (kind of, but not exactly, like how a glo stick works)

LONG VERSION: According to some studies, including this one, here is the general idea of how this reaction goes down:  Inside the cells, luciferin is packed in vesicles called scintillons.  This luciferin is produced throughout daylight hours.  The luciferin is usually bound to a protein called a Luciferin Binding Protein or LBP. At a neutral pH, LBP stabilizes the luciferin from being spontaneously oxidized.

When movement of surrounding water bends the cell membrane, it sends electrical impulses around the vacuole - which holds a bunch of protons (why?  I don't know).  These electrical impulses open proton channels, and those protons can now move from the vacuole into the cytoplasm (where the scintillons are kept).  The cytoplasm becomes acidified, and the process is activated in the scintillons.

When the pH drops to around 6, the luciferin and the LBP dissociate. In the process of being oxidized, luciferin briefly exists in an excited state, after which it decays to the ground state- releasing energy in the form of light.  The oxidation of the luciferin by the luciferase results in inactive oxyluciferin.  This reaction can happen more than once, but once the luciferin is used up, that dinoflagellate is done for the night, until it can replenish its supplies the next day.

Ready for the NSF image?  (It's government work, so it should be in the public domain.)

If you want to read more, or know where I got my information, you can check out this source (although I am not sure as to its reliability), or you can read the HowStuffWorks article on bioluminescence - esp this page, which has the more technical details of the chemical reactions.  Or, this Science Daily article is pretty good.  And if that's not technical enough, you may want to visit this UCSB biolum page for more information than you'll ever need. :)

Can I get some dinoflagellates and make them glow?

Yep.  Last year, some of my students did their science fair project on bioluminescence.  So, I bought some dinoflagellates (Pyrocystis fusiformis) from Sunnyside SeaFarms.  They basically do this:

Final randomness

Check out this art installation using bioluminesence (although using bacteria, not protists).  (From the NSF site) "This arch was composed with Petri dishes painted with bioluminescent bacteria. The piece--approximately 9 feet high by 5 feet wide--was installed in December 2002 at the O'Malley Library, Manhattan College, Riverdale, N.Y.  "Bioglyphs" was an exhibition of living bioluminescent paintings that brought science and art together in the form of a collaborative project involving students from the MSU School of Art, and science and engineering students from MSU's Center for Biofilm Engineering (CBE)."  (read more about the project)

That is about as cool as that giant petri dish Contagion billboard!

UPDATE 8.21.13:  Yonder Biology started a Kickstarter campaign to create a Dino Pet, a "dinosaur-shaped habitat for a species of bioluminescent marine algae that photosynthesizes during the day and glows at night."  Hilarious! Update 2019: Biopop is no longer in business.

Saturday, August 4, 2012

hermit crab in a glass shell

 Robert DuGrenier is an artist whose "sculptural work has had to do with creating environments which change over time due to forces in nature."  I was quite struck by the image of this hermit crab in a glass shell!  DuGrenier calls these "perfected" glass shells - crabitats!  (See more examples here.)

Two other works of his that sound intriguing (from his website)
  • [His] current work with honeybees creating sculptures in their hives is an example — [He'll] introduce blown glass objects into beehives that the bees will encase in honey comb patterns; these, in turn, become [his] sculptures.
  • A new series [DeGrenier] started is called “Llama-LLicks,” where, by licking their salt-blocks, animals will create interesting shapes which eventually will be cast into pillars of glass. (Unfortunately, I do cannot find any images of this on the web... I'd love to see it!)

Hermit crabs (Kingdom: Animalia, Phylum: Arthropoda, Subphylum: Crustacea, Class: Malacostraca, Order: Decapoda) belong to six families containing around 1100 species in total in 120 genera.  Unlike regular crabs, hermit crabs have a soft abdomen, so they need to inhabit abandoned shells for protection.  (that's where their name "hermit" comes from ... "one who lives alone")  Anyway, when they outgrow their shells, they need to leave and find a new, bigger shell to inhabit.  Usually, they find snail shells, but hermit crabs have been known to inhabit broken bottles, and maybe even a teacup?!

Personally, I have a grudge against hermit crabs stemming back from 3rd grade.  Upon returning from a field trip, I was tasked to feed the class pet.  It clamped on the soft flesh of my inner finger and would not let go.  My helpful peers and teachers did things like tap it, run it underwater, etc... while my 3rd grade self was convinced it would never come off.  Finally, it did, leaving me with a wicked blood blister.  Needless to say, I've been wary ever since. :)  But I do enjoy these glass shells as art!

Thursday, August 2, 2012

shadow QR code

Emart, one of the largest retailers in Korea, noticed that their sales slumped during the lunch hour each day, and they came up with a pretty darn innovative way to change this midday trend.

Their "Sunny Sale" solution was brilliant!  The company placed 3D QR codes across the city which could only be scanned between 12pm and 1 pm each day, when the sunlight cast the shadows correctly to complete the QR code.  Once the code was scanned, customers would be rewarded with special offers that could be used in the store or online.  Wow!  If you want to know more specifics on QR codes work, see my previous post on QR codes.

Seriously, what an amazing idea!  Check out the video below.

Wednesday, August 1, 2012

DNA tested dog poop

Wikimedia Commons
So, this is pretty crazy.  Apparently, a condo association in Palm Beach, Florida is requiring that residents pay $200 fee and the money will pay DNA Pet World Registry to take the dog's genetic fingerprint to be kept the information on file.

Why?  I'm so glad you asked.  To protect them from dog-nappers?  For research purposes?  Nope.  The DNA profile will be kept on file so that unclaimed dog poop left on the property can be collected, sent to DNA Pet World, profiled, matched to the offending dog.  The negligent owner will then be required to pay a fine of up to $1,000.

According to the article, "Feces identification is a booming business. DNA Pet World and PooPrints - its motto is "Match the Mess through DNA" - are spinoffs from BioPet Vet Labs."

It's totally worth taking the time to check out the PooPrints site.  Hilarious.

DNA sequencing is simply a technique that gives the order of nucleic acids (A, T, G, C) in someone’s (or some dog's) DNA.  This is what the folks are paying $200 to do - get the code for their dog and have that code put into a special database for future use.  Then, when a mystery poop sample is received, the same test can be run and the resulting poop's code compared to that database to find the guilty dog.  If you'd like to know the specifics of how DNA sequencing works - check out this great Cycle Sequencing Interactive from the DNA Learning Center.