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Saturday, March 10, 2012

Time-lapse video of an ant colony eating a scanner, captured with the scanner in question

[This is one of the most beautiful artistic collaborations with animals I've seen yet. I really think you should watch it. I suggest watching it on mute; I think the music is a poor choice. -egg]
Time-lapse video of an ant colony eating a scanner, captured with the scanner in question:

Fran├žois Vautier infested his flatbed scanner with an ant-colony and scanned the burgeoning hive-organism every week for five years, producing a beautiful, stylized stop-motion record of the ants' slow consumption of his electronics.

Five years ago, I installed an ant colony inside my old scanner that allowed me to scan in high definition this ever evolving microcosm (animal, vegetable and mineral). The resulting clip is a close-up examination of how these tiny beings live in this unique ant farm. I observed how decay and corrosion slowly but surely invaded the internal organs of the scanner. Nature gradually takes hold of this completely synthetic environment.

ANTS in my scanner > a five years time-lapse!

(via Kottke)

Friday, March 9, 2012

Seduced by Food: Obesity and the Human Brain

[Boy, this is a really great summary of the current understanding of obesity and appetite. -egg]
Seduced by Food: Obesity and the Human Brain:

Photo: grahamc99, CC BY 2.0.

In 1960-1962, the US government collected height and weight measurements from thousands of US citizens. Using these numbers, they estimated that the prevalence of obesity among US adults at the time was 13 percent. Fast forward to the year 2007-2008, and in the same demographic group, the prevalence of obesity was 34 percent (1). Most of this increase has occurred since 1980, when obesity rates have more than doubled among US adults, and extreme obesity has more than tripled. Welcome to the ‘obesity epidemic’. Today, more than one third of US adults are considered obese, an additional third are overweight, and largely as a consequence, each child born today has an estimated one in three risk of developing diabetes in his or her lifetime.

Since the obesity epidemic is a serious threat to public health and well-being, scientists have made it a research priority, and our understanding of its causes and consequences is rapidly expanding. Obesity can be the result of many interacting factors, including genetic makeup, developmental factors, physical inactivity, stress, insufficient sleep, social factors and smoking cessation. But dietary changes are clearly an outsized contributor. The obesity epidemic has closely paralleled a large (~20%) increase in per capita calorie intake, and according to the best available mathematical models, this increase can single-handedly account for the increase in body fatness over the last 30 years (2, 3).

Calories are interesting, but let’s delve deeper. We didn’t just wake up one day and decide to eat more—something is driving our increased food intake. But what? Research accumulated over the last two centuries has revealed that the answer lies in the intricacies of the human brain.

The Human Brain and Obesity

In 1840, a German doctor named B. Mohr made a critical observation while performing autopsies on obese subjects: some of them had damage in a part of the brain called the hypothalamus (B. Mohr. Wschr Heilkd, 6:565–574. 1840). Over the ensuing century and a half, researchers gradually uncovered a network of circuits in the hypothalamus dedicated to maintaining the stability (homeostasis) of body fat stores, by regulating food intake, energy expenditure, and the deposition of energy in fat tissue. This research culminated in the discovery of an extraordinary hormone called leptin in 1994. Produced by fat tissue in proportion to its mass, leptin enters the circulation and acts in the hypothalamus to regulate body fat stores. If you consistently restrict food intake, fat mass declines and so does leptin, and this signals the hypothalamus to stimulate hunger and make the body use calories more efficiently, in an attempt to regain lost body fat (4). Conversely, if you consistently overeat, the increase in fat mass and leptin suppresses appetite and increases calorie use until body fat stores have declined back to baseline (5, 6). Leptin and a few other hormones are part of a negative feedback loop that acts unconsciously to keep fat mass in a specific range, sort of like a thermostat does for temperature (7, 8). This is called the ‘energy homeostasis system’.

So if we have this built-in system to regulate body fatness, how does anyone become obese? Some researchers believe the energy homeostasis system defends against fat loss more effectively than fat gain. However, most obese people regulate their body fat just fine, but their brains ‘defend’ it at a higher level than a lean person. Going back to the thermostat analogy, in obese people it’s like the ‘temperature’ has been gradually turned up. That’s why it’s so hard to maintain weight loss—when body fat stores decline, the brain thinks it’s starving even if fat mass remains high—and it acts to regain the lost fat. If we want to understand how to prevent and treat obesity, first we have to understand why obese people defend a higher level of fat mass than lean people.

The most Fattening Diet in the World

To understand how this happens, let’s turn to animal research. Although rodents aren’t humans, they resemble us in many ways. Just like humans, rodents evolved to regulate body fat around an ‘optimal’ level to maximize survival and reproduction, and their systems for doing this are very similar to ours. Rodents also offer us the ability to control variables much more tightly than in human research. There are many ways to make a rat obese, but some are more effective than others. High-fat pelleted diets, composed of refined ingredients, are most common because they’re reliably fattening and their composition can be tightly controlled. But another diet, seldom used, is the most fattening of all: the ’cafeteria diet’. This diet has a lot to tell us about the expanding American waistline.

First described in 1976 by Anthony Sclafani, the cafeteria diet is basically a rat-sized buffet of human junk food, in addition to regular rat chow (9). The menu for a recent cafeteria diet study included such delectable items as Froot Loops, mini hot dogs, peanut butter cookies, Cheez-its, Cocoa Puffs, nacho cheese Doritos, cake, and BBQ pork rinds (10). These are what's known in the business as ‘palatable’, or pleasurable to the taste. On this regimen, rats ignored their regular chow, ate junk food to excess and gained fat at an extraordinary rate, far outpacing two comparison groups fed high-fat or high-sugar pelleted diets. Yes, human junk food happens to be the most effective way to overwhelm the body fat homeostasis system in rats, and neither fat nor sugar alone is able to fully explain why it’s so fattening. Importantly, over time, rats become highly motivated to obtain this diet—so motivated they’ll voluntarily endure extreme cold temperatures and electric shocks to obtain it, even when regular bland rodent pellets are freely available (11, 12).

The cafeteria diet is an exaggerated version of an unhealthy human diet, and not many people eat quite that poorly. However, have a look at the top six calorie sources in the current US diet, in order of calorie contribution: grain-based desserts (cake, cookies, etc.), yeast breads, chicken-based dishes, sweetened beverages, pizza and alcoholic beverages (13). Our eating habits aren’t as different from the cafeteria diet as we might like to believe.

In 1992, Eric Ravussin and collaborators tried to repeat the rodent experiment in humans. They gave volunteers unlimited access to a large variety of palatable energy-dense foods, in a setting where the researchers could monitor exactly what was eaten. Over the course of the next week, the volunteers more than doubled their usual calorie intake, gaining an average of five pounds (14). Further studies showed a similar effect (15, 16). Just as in rats, exposing humans to a large variety of palatable energy-dense foods causes an increase in food intake and rapid fat gain. To explain this, we need to bring our attention back to the brain.

My Neurons Made Me Fat

To understand why junk food causes fat gain in rats and humans, we have to explore two other circuits in the brain, beginning with the reward system. The reward system acts to gauge the desirability of food (among other stimuli) and reinforce and motivate behaviors that favor the acquisition of desirable food.  For example, if you eat a strong cheese for the first time, maybe it won't taste very good to you.  As it's digested, your reward system gets wind that it's full of calories, and the next few times you eat it, it tastes better and better until you like the flavor (17, 18).  This is called an acquired taste, and the reward system is what does the acquiring, motivating you to obtain a food it has deemed safe and desirable.  This is the same process that allows children to learn to like vegetables—which are low-calorie, often bitter foods that are initially unpalatable-- if they’re repeatedly paired with fat, salt or some other desirable quality. The reward system does the same thing with foods/beverages that contain drugs, such as coffee and beer, gradually making bitter fluids palatable and then delicious. 

Eventually, you may go out of your way to purchase the cheese or beer at the grocery store, and maybe you'll consume cheese or beer even if you aren't hungry or thirsty, simply because you like it.  This is an example of the reward system reinforcing and motivating behaviors related to foods it considers desirable.  What does the reward system consider desirable?  Calorie density, fat, starch, sugar, salt, free glutamate (umami), certain textures (easily chewed, soft or crunchy, solid fat), certain flavors, an absence of bitterness, food variety, and drugs such as alcohol and caffeine. Our brains are highly attuned to these qualities because they’re all elements of nutritious, calorie-dense foods that would have sustained our ancestors in a natural environment, but today, the exaggerated combinations of these qualities used by processed food manufacturers, chefs and sometimes even home cooks overstimulate our natural reward pathways (19).  Commercial foods are professionally designed to maximize reward, because reward is precisely what keeps you coming back for more. Processed junk foods such as ice cream, fast food, sweetened soda, cookies, cake, candy, pizza and deep fried foods are all archetypal hyper-rewarding foods.

Palatability is a related concept—it’s determined in part by inborn preferences (e.g., a taste for sugar and energy dense foods), and in part by the reward system (acquired tastes).  Palatability is governed by the hedonic system in the brain, which is closely integrated with the reward system. Imagine yourself sitting at the dinner table, stuffed after a large meal. Then the cake and ice cream appear, and suddenly you have enough room left for another 250 calories of food. Would you have eaten a large, unseasoned baked potato (250 calories) if someone had put one in front of you at that point? Foods that stimulate the hedonic system have a well known ability to increase food intake, and this effect can be replicated using drugs that activate these circuits directly (20).
The reward system is what motivates you to get food and put it to your lips, every time you eat.  When scientists shut it down in mice, they stop seeking food, even though they’ll still eat if it’s put into their mouths (21).  The hedonic system influences how much you eat once you begin a meal (22).  Together, reward and hedonic circuitry in the brain determine in large part how often you seek food, what foods you select, and how much you eat at a sitting.

Reward and hedonic systems, if stimulated in the right way by food or drugs, can increase food intake and body fatness. The marijuana ‘munchies’ (whose existence have been confirmed by science) are a good example of what happens when they’re chemically stimulated via the CB1 cannabinoid receptor in the brain (23). One of the most effective weight loss drugs ever developed, Rimonabant, is basically ‘reverse marijuana’, blocking the very same CB1 receptor that marijuana activates. Although it clearly reduces food intake and body fatness, it has failed to gain FDA approval because of negative psychological side effects (big surprise).

The ability of reward and palatability to influence food intake and body weight is mediated by connections between reward/hedonic and energy homeostasis systems. For example, if you haven’t eaten in a while, your brain detects declining energy stores and acts to increase food intake. It does this by increasing your motivation to obtain food, and your enjoyment of food once you obtain it— known as ‘hunger’, this sensation is caused in large part by energy homeostasis systems activating reward and hedonic systems. But the connection goes both ways. Reward and hedonic systems also influence energy homeostasis systems, such that excessively rewarding/palatable food can increase food intake and the level of body fat that’s ‘defended’ by the brain (24, 25, 26, 27). According to findings from my own research group (lab of Michael W. Schwartz) and others, the hypothalamus can also develop inflammation and chronic cellular damage that likely contributes to the defense of a higher fat mass as well, contributing to fat gain and making fat loss more difficult (28, 29), but the reason for this is not yet clear.

Addiction is what happens when the reward system is over-stimulated by drugs, sex, food or other high-reward stimuli. In susceptible people (about 3 percent of the US population), highly palatable/rewarding foods are quite literally addictive, leading to binge eating behavior. For the rest of us, these foods may not literally be addictive, but they do often drive us to eat them more than we think we should, despite negative consequences to our weight and health.

Living in a Toxic Food Environment

How has the American diet changed over the years, as obesity rates have soared? Taking a broad perspective, the largest change is that our food has become more like the ‘cafeteria diet’, awash in a large variety of packaged foods, restaurant meals and sweetened beverages. This is illustrated by the following graph, showing the remarkable shift away from home-cooked food over the last 130 years. It shows the percentage of total food spending dedicated to food eaten at home, away from home, or as fast food between 1889 and 2009:

Diet trials have shown that a ‘simple’ diet, low in palatability and reward value, reduces hunger and causes fat loss in obese humans and animals, apparently by lowering the ‘defended’ level of fat mass (30, 31, 32, 33). This may be a reason why virtually any diet in which food choices are restricted (e.g., Paleo, vegan, fruitarian), including diametrically opposed approaches like low-fat and low-carbohydrate diets, can reduce food intake and body fatness in clinical trials. As stated by Nora Volkow, director of the National Institute on Drug Abuse, “The common denominator of such diets is that neither allows consumption of the very caloric and seductive foods that combine high fat with high carbohydrates” (34). Hyper-rewarding/palatable foods—candy, chocolate, ice cream, chips, cookies, cakes, fast food, sweetened beverages and pizza—are uniquely fattening and should be the first foods to go in any fat loss attempt. Some people will benefit from further simplifying the diet.

Dietary changes over the last several decades have contributed to the obesity epidemic. The solution to this problem is at once simple and challenging. Returning to a diet of simple home-cooked food, made from minimally refined ingredients, would probably stop the obesity epidemic in its tracks, although it would not be enough to return all currently obese people to a lean state. The challenge is finding the time and discipline to do this while commercial junk foods and sweetened beverages are tasty, cheap and constantly under our noses.

[Stephan's blog is Whole Health Source - Mark]

Macro photos of the inside of musical instruments

Macro photos of the inside of musical instruments:

On Behance, art director Bjoern Ewers shows off the gorgeous macro-photo ads he produced for the Berlin Philharmonic, which depict the insides of instruments as airy atria (or, as Colossal has it, "vast and spacious, almost as if you could walk around inside them.")


(via Colossal)

Thursday, March 8, 2012

Invisible car

[Nice. -egg]
Invisible car:

[video link]

To promote its new B-Class car, Mercedes made it "invisible." Essentially, they draped one side of it in a fabric of LEDs that displayed an image of the scene behind the car, creating the illusion of invisibility. (This approach is similar to the active camouflage prototypes demonstrated by the University of Tokyo and elsewhere.) While a startling demo, it's not very practical -- it required 1,100 pounds of gear inside and $263,000 worth of LEDs.

"Invisible Mercedes brings James Bond technology to life" (Motoramic, thanks Gabe Adiv!)

DIY telerobot for photographing wildlife

DIY telerobot for photographing wildlife:

 Img Beetlecam-Wildlife-Photo-Robot-Lion-Closeup-1331226515393

Wildlife photographer Will Burrard-Lucas and his brother Matt devised a remote-controlled rover outfitted with a DSLR camera to get up close and personal with elephants, lions, and buffalo. After their first trip to Africa with their BeetleCam, they improved upon the design with a sturdier exoskeleton, telerobotic camera tilt, and HD video. The men have since gone back to Africa and captured some amazing lion images. If you want a BeetleCam of your own, they'll custom build it for you starting at GBP £1,250. BeetleCam Project 2011 (via IEEE Spectrum)

Mathematical origami exhibit at UC Santa Cruz

[Oooooooh. -egg]
Mathematical origami exhibit at UC Santa Cruz:


"Origami: Art + Mathematics" is a new exhibit opening at UC Santa Cruz on April 8. The exhibit is focused on computational origami, in honor of the late UCSC computer scientist and mathematical origami pioneer David Huffman. You may recognize some of the artists in the show from their appearance in the fantastic documentary film, "Between The Folds," which apparently inspired this new exhibit. It runs through June 16 at the UCSC Eloise Pickard Smith Gallery. Above, two pieces from the show: (left) "Black Man" by Eric Joisel; (right) "Suigintu," from "Rozen Maiden" anime and manga, by Brian Chan. "Origami exhibit at Cowell College"

Tuesday, March 6, 2012

A Complete Understanding is No Longer Possible

[An important reminder for older programmers; we grew up in a different world. -egg]
A Complete Understanding is No Longer Possible:
Let's say you've just bought a MacBook Air, and your goal is to become master of the machine, to understand how it works on every level.

Amit Singh's Mac OS X Internals: A Systems Approach is a good place to start. It's not about programming so much as an in-depth discussion of how all the parts of the operating system fit together: what the firmware does, the sequence of events during boot-up, what device drivers do, and so on. At 1680 pages, it's not light summer reading.

To truly understand the hardware, Intel has kindly provided a free seven volume set of documentation. I'll keep things simple by recommending Intel 64 and IA-32 Architectures Software Developer's Manual Volume 1: Basic Architecture (550 pages) and the two volumes describing the instruction set (684 pages and 704 pages respectively).

Objective-C is the language of OS X. We'll go with Apple's thankfully concise The Objective-C Programming Language (137 pages).

Of course Objective-C is a superset of C, so also work through the second edition of The C Programming Language (274 pages).

Now we're getting to the core APIs of OS X. Cocoa Fundamentals Guide is 239 pages. Application Kit Framework Reference is a monster at 5069 pages. That's help a file-like description of every API call. To be fair I'll stop there with the Cocoa documentation, even though there are also more usable guides for drawing and Core Audio and Core Animation and a dozen other things.

Ah, wait, OpenGL isn't part of Cocoa, so throw in the 784 page OpenGL Reference Manual. And another 800 pages for OpenGL Shading Language, Second Edition.

The total of all of this is 79 pages shy of eleven thousand. I neglected to include man pages for hundreds of system utilities and the Xcode documentation. And I didn't even touch upon the graphics knowhow needed to do anything interesting with OpenGL, or how to write good C and Objective-C or anything about object-oriented design, and...

(If you liked this, you might enjoy Things That Turbo Pascal is Smaller Than.)

Sunday, March 4, 2012

Winged, kinetic rings that flap

Winged, kinetic rings that flap:

Jeweler/metalworker Dukno Yoon makes beautiful, animated kinetic winged rings, sculptures and towers that flap when you flex your finger.

The contrast between metal structural form and natural feather, together with the repetitive and whimsical movements of fragile wings, provokes the imagination and evolves the intimate relationship between work and viewer/wearer.

Although the recent series, segmented wings have been focused on the formal challenge to engineer an intricate movement that simulates bird wings,

these works are intended to be a series of poems in which I develope my own formal language, interpret the nature of wings, create various structural forms with movements, and share the metaphor, imagination, humor, with viewer/wearer.


(via Craft)

Ten stone baby teased with chocolate

[Odd. -egg]
Ten stone baby teased with chocolate:

Entertainment in 1935. "The trouble is nowadays he refuses to be weighed at all so we don't really know if he's solid or hollow."

[Video Link]

Ten Stone Baby, a British Pathe newsreel from 1935.

Despite the newsreel's original title "Ten Stone Baby", the boy Leslie Downes is actually 3-years-old. Seen with his parents in a kind of pen, Leslie is sat in an armchair. Somebody then dangles a bar of chocolate into the pen and he immediately sets to work at fetching it.

We also see Leslie playing with bricks.