Saturday, August 9, 2014

Photon Hunting in the Twilight Zone

Deep in the twilight zone of the ocean, small, glowing sharks have evolved special eye features to maximize the amount of light they see, researchers report this week in PLOS ONE. The scientists mapped the eye shape, structure, and retina cells of five deep-sea bioluminescent sharks, predators that live 200 to 1000 meters deep in the ocean, where light hardly penetrates.

The sharks have developed many coping strategies. Their eyes possess a higher density of rods than those of nonbioluminescent sharks, which might enable them to see fast-changing light patterns. Such ability would be particularly useful when the animals emit light to communicate with one another. Some species also have a gap between the lens and the iris to allow extra light in the retina, a feature previously unknown in sharks.

Claes JM, Partridge JC, Hart NS, Garza-Gisholt E, Ho H-C, et al. (2014) Photon Hunting in the Twilight Zone: Visual Features of Mesopelagic Bioluminescent Sharks. PLoS ONE 9(8): e104213. doi:10.1371/journal.pone.0104213

In the eyes of lantern sharks (Etmopteridae), the scientists discovered a translucent area in the upper socket. The researchers suspect this feature might help the sharks adjust their glow to match the sunlight for camouflage.

I wonder if we computer nerds will evolve our visual system similarly.

Citation (Open Access):

Claes JM, Partridge JC, Hart NS, Garza-Gisholt E, Ho H-C, et al. (2014) Photon Hunting in the Twilight Zone: Visual Features of Mesopelagic Bioluminescent Sharks. PLoS ONE 9(8): e104213. doi:10.1371/journal.pone.0104213

Tuesday, July 29, 2014

Traffic Lights and Visualization


Photo Attribution: Helgi Halldórsson

From Susanne Tak and Alexander Toet comes "Color and Uncertainty: It is not always Black and White" which finds that:

'A 'traffic light' configuration (with red and green at the endpoints and either yellow or orange in themiddle) communicates uncertainty most intuitively. '

A video presentation is also online.


Thursday, July 17, 2014

Tic-tac-toe patent 8,770,625 in color

As noted on lines 23 and 24 in column 4 of the printed version of patent 8,770,625,
the U.S. Patent Office procedure discourages the use of color drawings. This makes Fig. 4 a little hard to visualize for the non color scientist (there are no color figures in Wyszecki & Stiles), so here it is in color (right pane):

Figure 4 of US patent 8770625

The invention is relatively simple. The general field is anti-counterfeiting as it applies to packaging. Professional counterfeiters have no problem faking ordinary measures like serial numbers and holograms, so the trick is to embed information that cannot easily be perceived by a counterfeiter, hence is omitted in the facsimile. Fortunately color does not exist in nature, it is just an illusion happening in our minds. Therefore, all we have to do is to create an illusion you can only perceive if you expect it.

As described in patent 8,770,625, a number computed from the—possibly counterfeited—serial number on the package can be encoded positionally in a tic-tac-toe grid. The marking is just above the visual threshold, so the naive counterfeiter will reproduce the same pattern on all packages. The trained inspector can then quickly assert whether an actual positional code corresponds, for example, to the possibly fake serial number.

Patent 8,770,625 is relatively short with just three claims, but reducing it to practice is a little tricky, even when all the steps are disclosed in the patent. The difficult part is to design the tool to determine experimentally the visual thresholds for the print process being used and the light conditions under which the inspections are expected to happen. You need to be skilled in the art.

The above figure is a screen-shot of that tool. To implement it you need to write a spectral color management system with CIE colorimetry to simulate the press on the display and vision colorimetry to model what the actual human visual system perceives. The details of the controls are explained in patent 8,770,625.

Depending on your viewing conditions, the above color version of Fig. 4 might be under the visual threshold. If that is the case, in the figure below we crank up the saliency and decrease the background coverage, so you will see the encoding for sure. If you have aliasing problems, you can click on the figures to display them at the original resolution in which they were created eight years ago, early July 2006 (time flies).

a more salient alternate to figure 4 of US patent 877,625

Wednesday, July 16, 2014

Why peacocks have eyespots on their feathers

"BIRD PARK 8 0189" by Myloismylife - LOKE SENG HON - Own work by uploader - LOKE SENG HON. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:BIRD_PARK_8_0189.jpg#mediaviewer/File:BIRD_PARK_8_0189.jpg"BIRD PARK 8 0189" by Loke Seng Hon (Own work) via Wikimedia Commons

Charles Darwin ventured that the magnificent trains on male peacocks, which feature ornamental eyespots called ocelli, evolved because of sexual selection. He speculated that there was a single origin, which sexual selection then enhanced. A new genetic study of peacocks and closely related pheasants found that this trait appears in some birds but not others, which suggests that it independently evolved repeatedly.

Article: Keping Sun, Kelly A. Meiklejohn, Brant C. Faircloth, Travis C. Glenn, Edward L. Braun, and Rebecca T. Kimball: The evolution of peafowl and other taxa with ocelli (eyespots): a phylogenomic approach. Proc. R. Soc. B September 7, 2014 281 1790 20140823; doi:10.1098/rspb.2014.0823 1471-2954

Friday, July 11, 2014

Red and Romantic Rivalry

Viewing another woman in red increases perceptions of sexual receptivity, derogation, and intentions to mate-guard.

Woman worker dressed in red in the Douglas Aircraft Company plant 1942

Research has shown that men perceive women wearing red, relative to other colors, as more attractive and more sexually receptive; women’s perceptions of other women wearing red have scarcely been investigated. Adam D. Pazda, Pavol Prokop and Andrew J. Elliot hypothesized that women would also interpret female red as a sexual receptivity cue, and that this perception would be accompanied by rival derogation and intentions to mate-guard. Experiment 1 demonstrated that women perceive another woman in a red, relative to white, dress as sexually receptive. Experiment 2 demonstrated that women are more likely to derogate the sexual fidelity of a woman in red, relative to white. Experiment 3 revealed that women are more likely to intend to guard their romantic partner from a woman wearing a red, relative to a green, shirt. These results suggest that some color signals are interpreted similarly across sex, albeit with associated reactions that are sex-specific.

Adam D. Pazda, Pavol Prokop, and Andrew J. Elliot: Red and Romantic Rivalry: Viewing Another Woman in Red Increases Perceptions of Sexual Receptivity, Derogation, and Intentions to Mate-Guard. Pers Soc Psychol Bull 0146167214539709, first published on July 11, 2014 doi:10.1177/0146167214539709

Wednesday, July 2, 2014

Venture capital

We used to talk about the Silicon Valley, but nowadays it seems more appropriate to talk about that triad comprising San Francisco, the Peninsula, and San Jose. People prefer to talk about the Bay Area, but that includes too much "regular economy" to define correctly the locus of the current gold rush.

The previous gold rush was about the commercialization of the Internet and was called the .com boom. Today's rush is nicknamed Web 2.0, but it is much less of a technology rush. While .com came after the end of the cold war and the end of research labs spilling redundant scientists and researchers to fill the cubicles of technical entrepreneurs, Web 2.0 is much more about business.

The analogy is with patents. Gold diggers take an old business idea, add the word computer, get a patent, then sue the incumbents for patent infringement and get away with plenty of dollars.

In the real economy, the Web 2.0 entrepreneurs come up with an idea for a service that can be implemented on the Web. Today's various cloud providers make this very cheap and simple. The monetization consists in giving the impression that the service is free. In reality, the customers are used to crowd-source information by coaxing them to provide detailed information about themselves. This information can then be sold to one of the more than a thousand personal information brokers operating in the USA.

Recently, companies have been valued at up to $100 per customer, which is very high. Accordingly, investors are poring billions of dollars into this area. Because this is gambling and speculation, the amount of money is not a good indicator of the real economy here.

I tried to look at a more conventional technology, namely the storage industry. My data is just accumulated from press releases and is not authoritative nor complete, because I have not gathered it systematically. However, here it is:

On the abscissa we have funding dates, categorized by quarters. On the ordinate we have companies related to storage (my apologies for mistakes). Each point is an investment round. The diameter represents the accumulated funding so far of the company. You can click on a ball to see the details.

When there is a long horizontal line of regularly spaced balls of the same diameter, the start-up is not really taking off. When the diameter is rapidly increasing, the company is getting a lot of interest from the investors.

We see that as we move forward in time, many more companies are getting funded and some companies are real winners. This is a good sign, because it means that investors are not just gambling their money on social network companies but also investing in the nut and bold technologies that allow for a healthy sustainable future-oriented economy.

Monday, June 30, 2014

These days the moon is made of cheese

From the remarks by President Obama at University of California-Irvine Commencement Ceremony, Angel Stadium Anaheim, California, June 14, 2014, 12:10 P.M. PDT.

Part of what’s unique about climate change, though, is the nature of some of the opposition to action. It’s pretty rare that you’ll encounter somebody who says the problem you’re trying to solve simply doesn’t exist. When President Kennedy set us on a course for the moon, there were a number of people who made a serious case that it wouldn’t be worth it; it was going to be too expensive, it was going to be too hard, it would take too long. But nobody ignored the science. I don’t remember anybody saying that the moon wasn’t there or that it was made of cheese.

Official transcript of the remarks: The White House Office of the Press Secretary

President Barack Obama

Thursday, June 26, 2014

Appearance of flamingos reloaded

A few years ago we mused on the color appearance of flamingos:

Now Daniel B. Thomas, Kevin J. McGraw, Michael W. Butler, Matthew T. Carrano, Odile Madden and Helen F. James have studied the issue in general for plumed animals and more importantly, over time.

They visually surveyed modern birds for carotenoid-consistent plumage colors. They then used high-performance liquid chromatography and Raman spectroscopy to chemically assess the family-level distribution of plumage carotenoids, confirming their presence in 95 of 236 extant bird families. Using their data for all modern birds, they modeled the evolutionary history of carotenoid-consistent plumage colors on recent supertrees. Results support multiple independent origins of carotenoid plumage pigmentation in 13 orders, including six orders without previous reports of plumage carotenoids. Based on time calibrations from the supertree, the number of avian families displaying plumage carotenoids increased throughout the Cenozoic, and most plumage carotenoid originations occurred after the Miocene Epoch (23 Myr). The earliest origination of plumage carotenoids was reconstructed within Passeriformes, during the Palaeocene Epoch (66–56 Myr), and not at the base of crown-lineage birds.

Link to the paper: Ancient origins and multiple appearances of carotenoid-pigmented feathers in birds

Tuesday, June 24, 2014

Portraits reveal rare disorders

Doctors faced with the tricky task of spotting rare genetic diseases in children may soon be asking parents to email their family photos. A computer program can now learn to identify rare conditions by analysing a face from an ordinary digital photograph. It should even be able to identify unknown genetic disorders if groups of photos in its database share specific facial features.

Read the article in the New Scientist: Computer spots rare diseases in family photos

Friday, June 20, 2014

Staring at computers all day alters your eyes

As a color scientist you already know that you have to position your display and chair combination so that the top bezel is at the same height as your eyes. The reason is so your eyes are not wide open and dry out. You also avoid sticking a personal fan in the display's USB port and tilt the display face slightly down so you cannot see light fixture reflections.

To my surprise, although this is usually explained in the ergonomics booklets shipping with computers, this is not generally known and scientists can still get research grants to study it (The Osaka Study):

The data obtained in the present study suggest that office workers with prolonged VDT (visual display terminal) use, as well as those with an increased frequency of eye strain, have a low MUC5AC (mucin 5AC) concentration in their tears. Furthermore, MUC5AC concentration in the tears of patients with DED (dry eye disease) may be lower than that in individuals without DED.

Citation: Uchino Y, Uchino M, Yokoi N, et al. Alteration of Tear Mucin 5AC in Office Workers Using Visual Display Terminals: The Osaka Study. JAMA Ophthalmol. Published online June 05, 2014. doi:10.1001/jamaophthalmol.2014.1008.

The paper costs $30, but you can read the current JAMA issue for free if you register.