June 2013 – Science Everyday

June 29, 2013 ScienceEveryday (medical imaging is separate) Post a Comment

Color me magenta..

Color me magenta..

Because magenta doesn’t exist; at least not in the electromagnetic spectrum. http://en.wikipedia.org/wiki/Electromagnetic_spectrum

Steve Mould explains that magenta or pink is created because we only have 3 different cones for color vision: red, green, and blue. It’s not surprising that most tv’s and photographs use the RGB colormap, i.e., only combinations of red, green, and blue.

In my research we often use different color spaces. I’ve mentioned RGB (red-green-blue). Some journals ask for figures in CMYK (cyan-magenta-yellow-black). But have you heard of CIE L*a*b* (CIELAB)? It’s an interesting color space. It can be helpful for image segmentation. http://en.wikipedia.org/wiki/Lab_color_space

Here are more color vision related posts:

Real color

http://goo.gl/PjQpT via Rajini Rao

Neurosciene and color

http://goo.gl/wgbpt via Rajini Rao

Epic why barns are red post

http://goo.gl/40F1J via Yonatan Zunger

Vision: How the World Gets into the Brain

http://goo.gl/jHh5z via Allison Sekuler (vision scientist/neuroscientist extraordinaire)

For some amazing vision science about the infamous mantis shrimp:

The Mantis Shrimp: From Rainbow Vision to Death Claws

http://goo.gl/U4F3k via Allison Sekuler

Mantis shrimp-photoreceptors

http://goo.gl/4g3bl via Rich Pollett

#ScienceEveryday when it isn’t #ScienceSunday

http://www.youtube.com/watch?v=iPPYGJjKVco&feature=share

June 22, 2013 ScienceEveryday (medical imaging is separate) Post a Comment

Jumpin’ jerboa

Jumpin’ jerboa

I have a hard time doing #Caturday but my friend Mz Maau suggested I add some kittens to my stream. I hope this jerboa is cute enough.

This one was caught in Afghanistan. Jerboa hop like kangaroos as you could guess. They use their long tail for balance while moving and for stability while standing. They can move as fast as 15 mph or 24 kph. Because they live in the desert and they have large eyes, you can guess that they are nocturnal. They are solitary and build permanent burrows; one for winter and one for summer.

The only interesting science tidbit I found, outside of the Wiki, is that they have a high level of vasopressin in their brains relative to other rodents. Vasopressin is a hormone involved with two things, vasoconstriction (closing of blood vessels) and retention of water. Being a desert animal, the later makes sense.

http://goo.gl/b6tPp

http://en.wikipedia.org/wiki/Jerboa

Image source: http://www.uncp.edu/biology/new/trace_landreth.html

#ScienceEveryday

June 11, 2013 ScienceEveryday (medical imaging is separate) Post a Comment

It does matter, Alijah should not have been in ICU

It does matter, Alijah should not have been in ICU

This story is precisely why I and other pro-science friends on G+ are relentless against anti-vaxxers and anti-science. You might ask why anti-science. This article clearly makes the case why I am against anti-vaxxers. From the article:

“If you google vaccines you get a lot of pros and a lot of cons, and you start to read all the cons and they start to weigh on you and you start to believe all the things that are said.”

“It looks like a fifty-fifty argument.”

Williams says that he was influenced by stories he read on the internet that the MMR (Measles, mumps and rubella) vaccine was linked to children developing autism; that they contain mercury and aluminium and that vaccines are promoted by drug companies purely for profit.

The reason that I’m against anti-science is many-fold. I’m a scientist and I have a passion for science and research. Anti-science people also tend to be conspiracy theorists. Herein lies the connection. The mentality that anti-science and conspiracy theorists spread can be the seed for doubt when it comes to important issues like vaccination. People think that it’s a personal decision, it’s not. Here’s a great article by Liza Gross, Doubt and Denialism: Vaccine Myths Persist in the Face of Science

http://goo.gl/f7Y1f

Herd immunity, in addition to not seeing kids like Alijah suffer, is another reason to vaccinate. If you have a minute, really just 60 seconds, and you want to learn what herd immunity is Herd Immunity – One Minute Medical School

Honey bee boo boo?

Honey bee boo boo?

There is a lot of concern about the decline in bee colonies. As most people know, if there are no bees, then many crops will suffer as they need the bees to pollinate them.

Wenfu Mao, Mary A. Schuler, and May R. Berenbaum, from the University of Illinois, recently published in PNAS that feeding high fructose corn syrup, as honey is taken away from bees, might be contributing to Colony Collapse Disorder. Since the 70s, corn syrup has been given to bees in colonies as their honey is harvested from them. Mao et al found that the bees immune system was stronger when exposed to p-coumaric, an enzyme that turns on detoxification genes. It’s found in pollen walls.

Reference:

Researchers find high-fructose corn syrup may be tied to worldwide collapse of bee colonies

http://goo.gl/mLWNz via physorg

What about pesticides?

Most of the focus has been on neonicotinoids, which are a class of neuro-active insecticides chemically related to nicotine. Pyrethroid is a compound used in commercial insecticides that is similar to pyrethrum, which is the active ingredient in Chrysanthemum flowers. Chrysanthemum flowers were used to kill lice for centuries. http://en.wikipedia.org/wiki/Pyrethroid

In this article by Frazier et al, they explain how neonicotinoids aren’t the sole problem. The amount of neonicotinoids found does not add up.

This is in contrast to pyrethroids which were found in 79.4% of samples at 36-times higher amounts than the neonicotinoids, on average.

Pesticides and Their Involvement in Colony Collapse Disorder

http://goo.gl/3BgDE

Here’s another article that explains more about neonicotinoids.

Neonicotinoid Seed Treatments and Honey Bee Health

http://goo.gl/pCYSe

Here’s a good site for bee info:

http://www.extension.org/bee_health

Image source: http://goo.gl/dXckv

#ScienceSunday

June 5, 2013 ScienceEveryday (medical imaging is separate) Post a Comment

When in Rome, build something concrete

When in Rome, build something concrete

Researchers at UC Berkeley are studying ancient Roman concrete in an effort to come up with a durable, yet green concrete. Shipping was instrumental to the expansion and sustainability of the Roman Empire. Using volcanic ash and seawater, the Romans developed concrete that has withstood the harsh marine environment for over 2,000 years. Scientist used the Advanced Light Source at Lawrence Berkeley National Laboratory (Berkeley Lab) to look at fine structures in the Roman concrete for the first time.

Roman concrete has a smaller carbon footprint because the modern cement (Portland cement) burns calcium carbonate (limestone) and clays at 1,450 deg C while lime used in Roman concrete requires only two thirds of that.

If Roman concrete is so good, why is it not still used? As the Roman Empire declined, the need for shipping and therefore the need marine concrete diminished. Also, modern concrete takes a fraction of the time to cure, compared to Roman concrete.

Edit

I should have defined what concrete is. Concrete is a composite material, made of “filler” (e.g. pebbles) and a binder (cement). So what is cement? More importantly, what is Portland cement, which is mentioned in the article and is the most common type of cement used. Portland cement is calcium silicates mixed with aluminum and iron containing clinker phases. (http://en.wikipedia.org/wiki/Portland_cement). So what are clinker phases? Clinkers are balls of sintered (baked) material made by taking a mixture of materials and heating them with very high heat. So the big difference between Roman concrete and modern concrete is really the clinker, not so much the filler. Also note that Roman concrete does not use steel reinforcing bars (rebar), so modern concrete has much higher tensile strength.

Cement Clinker on the Belt

More here:

http://newscenter.lbl.gov/news-releases/2013/06/04/roman-concrete/

Image source and reference: http://newscenter.berkeley.edu/2013/06/04/roman-concrete/