A blog about scientific and medical visualization and all that’s involved.

Archive for May, 2008

Interview–Walter Tschinkel

Posted by Janet on May 22, 2008

Last Sunday I saw a segment on the morning news about Dr. Walter Tschinkel, an entomologist at Florida State University who studies ant nest architecture. On the news, Dr. Tschinkel and his team melted pieces of aluminum in a large can, poured it down the opening of an ant nest. When the metal hardened, the team then excavated a large beautiful cast underground that represented the tunnels and chambers of the ant colony. After seeing this, I became fascinated by the process and immediately contacted Dr. Tschinkel to find out more about his work:

me:How did you become interested in ants?
Walter Tschinkel: “I first became interested in the chemical communication in [social] insects and began working with ants. This then led to [the study of] social biology of ants and eventually I started studying the architecture in nests (about 15 years ago). I began casting nests first using dental plaster, and 6 years ago started using metal.”

me:How did you come up with the idea of making casts of ants’ nests?
Walter Tschinkel: “I was trying to pioneer the study of nest architecture by describing the range of architecture between species and within species. I would find nests and make plaster casts. The disadvantage of plaster casts is that they break easily so after you dig them up, you have to glue the pieces back together again. But the advantage is that you can break them into pieces, soak them in water for about a month to break the pieces further, and study the ants. Occasionally we use metal [casting] for display, or we use them for nests with narrow channels. Zinc is what we use. The disadvantage is [in addition to] sacrificing all the ants, you can’t count them afterwards.”

Above: Stereo Images of casts of ant nests. Cross your eyes to see the form in 3D.

me:Wow. So when you break apart your plaster casting, do you place different chambers in separate containers to compare the ants?
Walter Tschinkel: “Sometimes we do, but mostly we look at all the ants at the same time. Usually we look at all the ants together when the chambers are close together, but if the species’ nests have a long vertical shaft with horizontal chambers on the bottom, we may separate the part and look at it on the side.
I have three or four papers on this topic. Did I send them to you? They’re posted on my website.”

me:I don’t believe I got those links, but I’ll definitely look for them on your website later. *brief silence* Did you have any unexpected findings the first time you saw the cast?
Walter Tschinkel: “Ohh yes. At the time I was studying fire ant colonies and had theories about their nest architecture, so I decided to take a plaster cast [to compare with my theory]. The plaster cast showed something completely unexpected, which shows just how complicated the nests can be and how difficult it is to study something three-dimensional that you can’t see. So after that I expanded on that idea and started making casts of other species.”

me:How do the nests of different species compare with nests of the same species of ants? Is there anything else that’s interesting and you would like to share?
Walter Tschinkel: “A typical ant nest is made up of one or more vertical shafts that link together the horizontal chambers. Details vary between species. [In general] different species have different nests architecture; related species have similar nest architecture. Also interesting is the strong [positive] relationship between the number of ants [in the nest] and size of that nest…actually, the nests are built by different ants, so the majority of the ants living in a nest are not the ones who built that nest, but the relationship holds anyway. *brief pause* The ants are born in bottom of the nest. During their life cycle they gradually move up and change jobs. Near the last part of their lives they go out onto the surface and these are the ants that we usually see looking for food.”

me:That’s very interesting! How do you experimentally determine their age in relation to which part of the nest they occupy?
Walter Tschinkel: “We do so by tracing the pigmentation of the ants—the ants are pale when first becoming the adult, so we can look at color of ants throughout different parts of the nest and find that there are more pale ants near the bottom. Or we look at mandible wear—the older the ant, the more wear there is on their mandible. With this method we judge their relative age based on relative wear.

*long pause as I go through my list of questions to make sure I didn’t miss anything*
me:Ummm…ok….can you share the details about the process and materials of casting the nest?
Walter Tschinkel: “I use orthodontal plaster because it’s cheap and you can buy it online in any dental supply store. For metal I chose zinc for its low melting point. I get the zinc free from old anodes at marine shipyards. Zinc corrodes and steel doesn’t, so they attach zinc bars to the hull of the ship, and replace them when they are about half corroded away. Sometimes I use aluminum from old aluminum scuba tanks. We place charcoal in an insulated garbage can, and put the aluminum in the bottom half of a steel scuba tank to melt metal [placed in a smaller container within the tank and then pour the molten metal down the nest opening].”

Above: Materials used for metal casting, including the kiln (big metal container in the center).

Above: Pouring metal into a nest opening.

At this point we concluded the bulk of the interview and began chatting a little about other things. I learned that Dr. Tschinkel used to do pen and ink illustrations for his own publications, and now does color pencil illustrations while traveling. Here is a color pencil drawing he shared with me:

For more information on Walter Tschinkel and his work, go to: (there are a few stereo images on this site)

Posted in biology, interviews | Tagged: , , , , | 2 Comments »

DNA Art at MoMA Store

Posted by Janet on May 21, 2008

DNA print

For about $500, you can have your DNA profile printed and framed through the Museum of Modern Art online store website, putting a new spin on the concept of family portrait. This full service is offered through a company called DNA 11, which controls the entire process from running a gel to the printing and varnishing. Artists who work on your print even sign the back to ensure authenticity. A swab kit is provided with each purchase to collect a sample from you, a family member, a pet, or anything that contains DNA (but why would you want to pay $500 to frame chicken liver DNA?). Once the company receives your DNA sample, it can take up to six weeks to deliver your high-quality print.

Speaking of DNA art, the MoMA store also features DNA-inspired jewelries by Andrea Valentini such as this bracelet shown below. Earrings and necklaces are also part of this collection.

DNA bracelet

Posted in photography/imaging, stores/products | Tagged: , , , | Leave a Comment »

Ear Prosthesis Part 5 (final)

Posted by Janet on May 19, 2008

I know it’s been a long time since my last post with the prosthesis. There were some major changes with the project schedule, but I finally finished the last part–the extrinsic coloring.

We started by visually analyzing the prosthetic ear from the last step to see how the colors match up with the patient’s skin. Then we decide which colors to apply for a better color match. In my case, the ear came out of the intrinsic coloring process a little too green and yellow, so I will apply various shades of red to even out the tone and bring the ear back to life.

The materials: color pigments and silicone (a different type from the ones used for the intrinsic part of the ear).


I put some pigments on a piece of palette paper and some silicone in a cup. Then I gradually mixed the pigments with silicone using a blunt brush until I got the desired color. The colors can be painted or stippled onto the ear. I found that when I stippled the colors, they tend to stick to parts of the ear in clumps. I actually preferred applying the colors onto the general section and then buffing the colors away using a piece of gauze to create a more subtle transition between the layers. Sometimes buffing the colors can make the ear too glossy, so I’ll reapply some texture by dabbing the ear using a textured surface.


Below: the prosthetic ear completed with extrinsic coloring.


Posted in my projects, prosthesis | Tagged: , , | 1 Comment »

Pop Quiz Solutions

Posted by Janet on May 18, 2008

The winner of the pop quiz has been contacted by e-mail today. The answers I was looking for were 913.1 kilobytes for question 1 and 3.57 megabytes for question 2. I have accepted a few other reasonable responses as well. These numbers can either be calculated or looked up in Photoshop by entering the parameters.

Here is the most detailed (and correct) response I received. This reader was unfortunately not the winner, but he gets credit for showing the calculation:

1). Assume that there are 256 greyscale levels. This means that each dot
takes up log2(256) = 8 bits = 1 byte of storage space. At 100 dpi (where
dpi is a linear measure), the number of dots in one square inch is 100 x 100
= 10000 dots per square inch.

An 8.5″x11″ image occupies 93.5 square inches. The number of dots in this
space is therefore 93.5*10^4 = 9.35*10^5. At 1 byte per dot, this
corresponds to 9.35*10^5 bytes. Under the strict definition of 2^10 bytes
per kilobyte, this becomes approximately:

(9.35*10^5)/(2^10) = 913.09 kilobytes.

2). For a CMYK image, assume 8 bits each are allocated to the C,M,Y, and K
channels for a total of 32 bits = 4 bytes per dot. As calculated in (1), an
8.5″x11″ image has 9.35*10^5 dots total. This results in an image size of:

9.35*10^5*4 = 3740000 bytes

Under the convention that 2^20 bytes = 1 megabyte, this is:

3740000/(2^20) = 3.57 megabytes

Posted in math/engineering, quiz/giveaway | Leave a Comment »

Pop Quiz Giveaway

Posted by Janet on May 15, 2008

Here is our first pop quiz giveaway. E-mail the correct answer of both questions below and how you came up with the answer to by 11:59pm this Saturday, May 17 and I will pick a random winner of a brand new ipod shuffle. You must provide the correct answer and describe your method of deriving it in order to win. Please do not post in the comments section unless you want everyone to see your answer.

1. What is the file size of a 8.5″ x 11″ grayscale image at 100dpi? Give answers in units of kilobytes.
2. Give the file size (in megabytes) of a 8.5″ x 11″ CMYK image at 100dpi.

Posted in math/engineering, quiz/giveaway | Leave a Comment »

Orphan Works Act Follow Up

Posted by Janet on May 11, 2008

Dena Matthews, partner, illustrator, and animator of LifeHouse Productions, has drafted an letter to be passed along to anyone who are to be affected by the Orphan Works Act. Her letter indicates that ANYONE, not just visual artists, can be affected negatively by this. Please read her letter below and forward it to anyone you know.


Dear friends and artists,

I encourage you to support all American artists by voicing opposition to the Orphan Works Acts that are being fast-tracked through Congress. It’s important that you act now – because Congress (both House and Senate) could be voting on this legislation this month.

Here is a brief summary of the problem.

* The Orphan Works Acts, if enacted would change copyright law in such a way that it would be too costly (time and money) to make a living as a visual artist. There would be less of a need for new art because all one’s existing and new work would be open for others to use for free. Today we call those people- who use art without asking- infringers, those who steal art for their own profit.

* The Orphan Works Acts would affect visual artists who do not make a living from their art (create just for the joy of it). Someone, an infringer, would be able to use your art anywhere they like to make a buck and potentially in ways you would object.

* The Orphan Works Acts would also affect anyone who takes snapshot photos and shares them through email or on the web. Your personal family memories could be used by unscrupulous people or in ways you may object – again just to make a buck. The Orphan Works Acts also opens up privacy issues- by allowing others to distribute and sell pictures of your family members and friends.

The Copyright Act of 1976 was created to allow artists to profit from their work thereby encouraging artists to create- a priceless gift that we presently are able to give to the world.

There may be a desire for libraries, museums, etc to acquire truly orphaned works – those in which the author will never be located. Most visual artists would support this cause for the greater good. But these Orphan Works Acts being pushed through congress are written so broadly, they do not take into account the devastating impact they will have on living and available (who can be located) artists.

Please ask your congressmen to vote in opposition to this act- in both house and senate.

Here’s a link to a web tool that allows you to do so effortlessly:
Select the letter that best represents you and edit it as you see fit. Then click to submit – and your letter will be sent immediately electronically to all your congressmen.

Please forward and crosspost widely.

Thank you,
Dena Matthews


LifeHouse Productions
Specializing in 3D medical animation

ph: 860.432.9177


Posted in business | Tagged: , , | Leave a Comment »

Chris Welch Art

Posted by Janet on May 10, 2008

Some really nice illustrations/animations/sketches by digital artist Christ Welch– Thanks Scott for finding this link!

A few images from the site:




Posted in miscellaneous | Tagged: , , , , , | 1 Comment »

Copyright and the Orphan Works Bill

Posted by Janet on May 10, 2008

I have not yet talked about the business aspect of an illustrator, but perhaps I should, seeing how it is actually a huge part of what we do behind the scene. We all enjoy the drawing part a little too much, and sometimes that’s all we want to do. But when this is what you do for a living, you must learn how to play by the rules.

The current copyright law states that a work is yours from the moment you create it. It sounds crazy, because it means that you don’t have to do anything other than creating something for the work to be “protected” under copyright law. It’s a little bit easier to reinforce your rights by putting a copyright symbol and a date next to your signature, and you can enforce your rights by actually registering the work, but the bottom line is, if you make it, it’s yours. So a lot of times when the illustrator is making a living, he/she is not selling the actual work, but the right to use a piece of work under specific conditions.

Now, the Orphan Works Act of 2008 wants to take away that right by declaring any work an “orphan” if the creator or copyright owner cannot be found. It will allow anyone to use your work without permission or payment as long as they have done a “search” and are unable to find the creator or copyright owner. In other words, it devalues our works and this is bad. Very bad. Here is a YouTube version of Mark Simon’s interview with Brad Holland of the Illustrator’s Partnership about the Orphan Works bill and how it affects illustrators.

Additional resources:
-A full version of the interview can be downloaded here.
Orphan Works resource page from the Illustrators’ Partnership website.
Legislative Action Center.

Posted in business, videos | Tagged: , , | Leave a Comment »

AMI Meeting Update

Posted by Janet on May 8, 2008

The AMI 63rd annual meeting is held this year in Indianapolis, IN from July 16-20. Registration is now open. Register before June 1 for the advanced rate. Otherwise you will pay $100 more. Students can reduce the registration fee by up to $120 (for student members) or up to $100 (for student non-members) by volunteering through the AMI Work Study Program. Registration information can be found on

Professional and student members can enter works into the AMI Salon. There is a separate registration for the Salon. The deadline for Salon registration is June 9. Animations and interactive media must be delivered by June 16, and other artworks must be shipped by July 7 and arrive by July 11. Salon registration fees are $50 for professional members and $45 for student members. For more information on the AMI Salon, go to

General Information regarding the conference:

Posted in announcements | Tagged: | Leave a Comment »


Posted by Janet on May 7, 2008

Comic from (# 331).

Posted in miscellaneous | Tagged: , | Leave a Comment »