Monday, June 28, 2010

Has Amelia Earhart Finally Been Found?

Okay, it may not be too science-y, but it's really cool to think that the folks at The International Group for Historic Aircraft Recovery (TIGHAR), may have actually found the remains of Amelia Earhart and Fred Noonan's crash.

Amidst the remains of campfires filled with fish skeletons and other animal parts, researcher Ric Gillespie and his team found a woman's compact, clothing, and even a pocket knife that was smashed to separate the parts. It helps that the discovery took place on Nikumamoro, the island in the South Pacific where the two are thought to have landed when they ran out of fuel in the June of 1937. In 1940, the skeletal remains of a female castaway were found on the island (though lost). The team is testing for contact DNA on many of the 100 items recovered from the site, hoping to find enough information to determine if this was, in fact, Earhart and Noonan's last resting place.

You can view an audio slide show here, where Gillespie discusses the expedition and the findings.

Wednesday, June 23, 2010

Praise for Skloot's New Profile of HeLa

There are few things here at Visionlearning that get us more excited than seeing the incorporation of the process and history of science with the practical aspects. That's why it was so thrilling to read Rebecca Skloot's new book, The Immortal Life of Henrietta Lacks.

If it's been a long time since you heard the word "HeLa," here's a brief reminder. HeLa cells, named after the woman they were taken from (Henrietta Lacks), are used in essentially every form of cell research that has been done since the 1950s. Jonas Salk's discovery of the polio vaccine, our understanding of the effects of radiation on the human body, current treatments for cancer -- none of these would exist if it wasn't for the existence of Henrietta Lacks. But for as long as we've celebrated new discoveries in cell biology and the treatment of disease, rarely does this include the celebration of the woman from whom this immortal cell line came.

That is, until now.

In Skloot's thorough book, over a decade of research and interviews with the Lacks family, scientists involved in the treatments of Henrietta, and an assortment of professionals at Johns Hopkins culminates in a wonderfully engaging story of Henrietta and her unintentional contribution to science. The text honestly explores the question of ethics in research, how racial segregation impacted treatment, and brings to light a pressing question yet to be solved -- What rights do we retain when our body tissues are removed from our body?

It's difficult reading at times, not because of composition, but because of the reality with which we are confronted. While it wasn't customary in the 1950s, nor in many instances today, to ask a patient whether their excised tissues can be used in research, Henrietta's case was a bit more extreme. It's not just that the woman whose aggressive cancer cells continue to aid science 60 years after her death was never asked to donate tissue for research. Her family was never asked if researchers could take samples of her cervix once they realized what they'd stumbled upon, nor told after they had done so. And the affronts and exploitation continued well into the new millennium, with the family being asked to donate blood samples and given little information as to why. As Skloot shows, it wasn't until she was well into the research of this book and speaking with the family that they even understood what was so important about Henrietta's cells.

Alongside the history of the Lacks family, we get a well-written explanation of the evolution of HeLa's use. From Gey's first culture in the lab, to the sharing of HeLa cells with other researchers, to the multi-million dollar cell culturing businesses that grew out of that initial culture, we see how important ethics, creativity, communication, and proper laboratory techniques are to the world of scientific research.

Skloot's profile of the Lacks family and use of HeLa cells in research is a must read for everyone. It's not just for those interested in understanding the process and history of cell biology and disease research, but for anyone who has every wondered about the discoveries in medicine that have helped to prolong life and cure once-deadly diseases. Without Henrietta Lacks, we would certainly be living in a very different world.

Interested in seeing more about this book? Click here: The Immortal Life of Henrietta Lacks

Friday, June 18, 2010

Oooooh, Pollination!

June 21st kicks off National Pollinators Week, and good thing, too. These often-forgotten heroes deserve a little attention now and again. After all, they support our delicate ecosystems by sharing the love, helping in the reproductive process of the plants that provide nourishment and protection. If you're interested in participating in the US Department of Agriculture's activities from the 21st to the 27th, click here.

If you're interested in learning more about pollinators and their important role in our worldwide ecosystems, pick up The Forgotten Pollinators by Stephen Buchmann and Gary Nabhan. This book has been around for over a decade, but is as poignant and relevant as ever. Combining Buchmann's entymology with Nabhan's ethnobotany and skill at nature writing, they give us a wonderfully entertaining text that is full of useful information. It's a must for any novice naturalist, or for the student of ecology.

Wednesday, June 16, 2010

One Fish, Two Fish...Sharks and Other Open-water Predators Using Their Math Skills

Look up the word "fractal" in the Merriam-Webster Dictionary and you get the definition shown at right. Accurate, but not terribly enlightening. In more layman's terms, think of fractals in this way: a fern frond is a long stem with lots of smaller "leaves" on it. The large frond is somewhat elliptical in shape, with the mid-section of the frond being much wider than the base or tip. Now, if we look even closer at the frond, we see that those small "leaves" that run along either side of the frond are, in essence, much smaller fronds. They look the same as the larger whole. This is one example of fractal geometry at play in nature. The small parts that make up the whole are the same shape and proportion as the whole itself.

How does this relate to sharks and other open-water predators? For many years, scientists have been trying to see whether such fractal geometry occurs in the actions of living organisms -- the so-called Lévy-flight foraging hypothesis. This hypothesis suggests that a foraging pattern is composed of long trajectories, followed by short, random movements that when looked at on a large scale over time resemble the smaller patterns. Studies have been conducted on birds such as albatross, on deer and other foraging animals and have shown that such fractal patterns exist. Unfortunately, discrepancies in the data collection have cast much of this research into question. That is, until now.

In June 9th's issue of Nature, Humphries et al. show that the Lévy-flights are adopted by fourteen separate fish species when food resources are scarce and irregularly dispersed. Rather than following a random Brownian movement pattern, when food resources were significantly reduced, the sharks and other fishes in the study resorted to following more deliberate search patterns. They would swim long distances in one direction, then stop and make a series of shorter, random movements looking for food. In areas where food resources were abundant, the fishes resorted back to the random Brownian movements.

The research, which you can read in full here, shows that environmental circumstances more than any other factor determine foraging behavior of these specific fish species. Further research will need to be conducted to see if these "animals evolved such that they exploit Lévy flights as an optimal search strategy for life in complex, highly changeable landscapes."

For more on mathematics in nature, read Visionlearning's Wave Mathematics module.

Friday, June 11, 2010

The Frustration of Flow Rate

Since the Deepwater Horizon explosion on April 20th, there has been a lot of speculation about the amount of oil that is actually flowing into the Gulf. The estimates have varied considerably. Yesterday, the US government announced that the amount of oil is likely to be double what was originally estimated, approximately 25,000 to 30,000 barrels per day. But we still do not know for certain, and this is frustrating to many who feel that with the technology we have and the amount of time this has been going on, we should be able to come up with definitive numbers.

Leaving aside speculation about whether or not BP is being upfront about their data, let's take a moment to look at how flow rate is generally calculated and why some of these estimates have been drastically different.

Whether you're a plumber or an oil driller, there is a general formula used to understand the flow rate of a liquid leaving a pipe:

Velocity  X  Pipe Area = Flow Rate

Velocity is a vector quantity and is measured by the speed of an object over time. When we talk about the speed/time, it refers to constant velocity -- both the size of the object and the direction remain the same. Because a pipe is a fixed object, the direction of the oil within it is obviously not going to change. But when it leaves the pipe, it encounters the pressure of water one mile beneath the surface (approximately 500 times greater than at sea level) and other particulates, which can deflect the direction of the flow. How scientists are calculating velocity thus far has been a bit murky. Measuring it within the pipe will generate one number; outside the pipe, another.

Now, the pipe area. This is one number that should actually be pretty straight-forward. The area of a cylinder is the perimeter of the opening multiplied by the height. In this case, it's the perimeter of the pipe opening multiplied times the length of the pipe. One of the reasons we include pipe area in calculating flow rate is because the friction of the inside of the pipe applies force on the liquid.The longer the pipe or shorter the diameter, the greater the force applied. Cutting the pipe increased the perimeter because it removed the valve that was slowing the flow down -- so the flow rate has actually increased since this was done.

In the case of the Gulf, we want to know more than the flow rate -- we want to know the mass flow rate. We want to know how much oil is coming into the area, not just how quickly.

In order to calculate mass flow rate, we need to incorporate density into the equation:

Mass Flow Rate = Density X  Velocity X Pipe Area

Density is measured by dividing the mass of an object by its volume (for more on density, click here). When you have a fixed object, calculating density is rather straight-forward: find its mass, measure its volume, do the math, et viola. Unfortunately, the crude oil coming out of the sea bed in the Gulf is not uniform. It is composed of solid particulate, gas and liquid. And the concentrations of these will vary over time. Add to the mix that BP is injecting dispersants into the pipe, and density becomes even more difficult to calculate. 

Clearly, the fact that this leak is occurring in three places 5,000 feet below the surface of the ocean means that there are more factors at play than simply multiplying a few numbers together. It becomes a matter of getting numbers that accurately reflect the averages for density and velocity, which has been quite difficult considering the locations of the three leaks.

With luck, the leaks will be stopped soon enough so that we no longer have to worry about whose numbers are correct.

Tuesday, June 8, 2010

Taking "Obsession" to a Whole New Level

The Wall Street Journal published an article today on some interesting scientific research. Apparently, Calvin Klein's cologne, Obsession, is more than just for men.

As the article notes, zoos all over the world have long been using the practice of spraying perfumes and colognes throughout animal grounds in order to keep them stimulated and curious. At the Bronx Zoo in New York, Curator Pat Thomas decided to see if the types of scent had much affect on the response of cheetahs to the new odors. While a cat's sense of smell may not be as developed as its other senses, the average cat's ability is still 14 times greater than a human's -- which makes those perfumes and colognes particularly pungent, and Thomas' study showed that the big cats have very particular tastes.

Using 24 different types of perfume and cologne, Thomas measured the amount of time it took for the cats to first notice the new scent, and then how long they spent investigating it. The results were varied. Estee Lauder's Beautiful apparently interested the cheetahs for a whopping two seconds. But Klein's Obsession? 11.1 minutes. More than simply investigating the scent, the animals tended to cuddle up next to whatever was sprayed with the cologne.

This research was impressive enough to convince Thomas to share his finding with other scientists studying big cats, and has since had a significant impact on field research. Now, scientists all over the world are able to get better information about the big cats they are studying. As the article noted, one researcher studying jaguars has had a significant increase in usable data. Relying on motion-detecting cameras to record the presence and distinct markings of jaguars, he has managed to lure more of the elusive animals to his camera areas by leaving objects spritzed with the cologne nearby. The Wildlife Conservation Society has even decided to make the use of Obsession-spritzing a regular part of all of their jaguar studies!

Many of these organizations and zoos rely on donations from the public in order to operate -- and this includes donations of scents. If you happen to have some Obsession lying around that you don't think you'll use, contact your local zoo to see if they might like it. And if that's your favorite cologne, you might want to think twice about wearing it the next time you are in the area of big cats...

For more on research methods, visit's Process of Science page.

Image courtesy of Bernie Condon at

Monday, June 7, 2010

To Caffeinate or Not to Caffeinate

Researchers at Bristol University in the UK have something to tell us regular coffee, tea and soda drinkers. That morning pick-me-up isn't really picking us up, it's pushing us down.

In the study about to be published in Nature's journal Neuropsychopharmacology, Rogers et al. share with us that our regular caffeine habits are actually causing a dependency that leaves us in withdrawl. After 16 hours without caffeine, regular caffeine consumers and non-consumers were divided up. Some were given caffeine tablets and others a placebo. The results show that the "post-caffeine levels of alertness [in regular caffeine consumers] were actually no higher than the non/low consumers who received a placebo, suggesting caffeine only brings coffee drinkers back up to 'normal'."*

So what does that tell us regular visitors to the coffee pot? If we want to increase our alertness, we might think about skipping the "regular," grabbing the decaf, and doing something that is proven to increase blood flow to the brain -- like taking a walk.

Image courtesy of Michelle Meiklejohn from