Tibet from above, NASA/Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center

This image via Boston.com’s Big Picture feature.

More satellite images via NASA: http://earthobservatory.nasa.gov/NaturalHazards/category.php?cat_id=11

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Not all researchers agree that relative amounts should be the only focus.  Two Harvard papers, both written in part by WC Willett, concluded that the issue is more about raising omega-3’s, and that lowering omega-6’s showed no appreciable benefits.  But still, even though there’s disagreement over the ratio, everyone seems to agree that omega-3’s have importance.  Abstracts here and here.

So finally, what food sources contain which kinds of fats?  These two PUFA’s come from a range of meats, vegetables, nuts, and their oils, often both in one kind of food.  But still there are certain foods that are clearly dominated by one and not the other.

Good sources of Omega-3’s:

ALA: flaxseed and oil, walnuts and walnut oil, canola oil, leafy green vegetables like broccoli and spinach, grains

EPA/DHA: wild fish (especially salmon), grass fed beef, eggs. In general the more natural the animals eat, the better.

Good sources of Omega-6’s:

LA: safflower, sunflower seeds, vegetable oils, corn oil

AA: animal meats, farmed fish, eggs.  In general, animals that have a heavily processed and corn derived diet have higher omega-6 to 3 ratios.

The bottom line behind all this research and nutrition hype seems to be that we should eat what evolution carved us out to eat.  More omega-3’s, less omega-6’s.  More real food, less processed and overly preserved.

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Starting with basics, both omega-3 and omega-6 fatty acids are essential polyunsaturated fatty acids (PUFA’s).  The ‘essential’ term refers to the fact that even though our bodies need both these fats for healthy functioning (all cells are surrounded by lipid membranes), they can’t manufacture them on their own.  There’s another PUFA – omega-9 – that isn’t nearly as well known, and is not an essential fatty acid.

Nothing in the body is simple; there are several types of omega-3 and omega-6 fatty acids, both involved in a lovely web of reactions, at times competing for the same enzymes. For a poorly designed but accurate diagram, go here.

The major types of omega-3 fatty acids are ALA (alpha linolenic acid), EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid).  All of these are found in foods, but to a small extent ALA helps produce EPA and DHA.

Both EPA and DHA are antiarrythmic (keep the heart beating steadily), decrease triglycerides, decrease VLDL cholesterol, increase HDL cholesterol, and decrease cytokines (short messengers between or within cells, usually involved in inflammation).  EPA also decreases platelet aggregation, vasoconstriction, and other inflammation mediators.  DHA is also well known for its importance in brain functioning and development, making up a significant amount of infant brain mass.

Omega-6 has two well known stars: LA (linoleic acid) and AA (arachidonic acid).  Like the Omega-3 acids, both of these are found in food sources, but to an extent the body also makes AA from LA.  AA has been shown to lower LDL cholesterol.  AA acts more strongly opposing the omega-3 EPA by increasing platelet aggregation, vasoconstriction, and inflammation.

All the actions listed above are healthy body responses, in certain situations. The issue is that you can have too much of a good thing.  Inflammation, for instance, is how the body rightly deals with cuts and some foreign invaders.  However, when kicked into overdrive, it is also a symptom and/or cause of many modern diseases – heart disease, arthritis, type 2 diabetes, some cancers, and asthma.

More on this topic to follow, including which fats are found in which foods, and reasons behind recommended intake amounts.

Some sources:
Dietary n-6 and n-3 polyunsaturated fatty acids: From biochemistry to clinical implications in cardiovascular prevention.

Metabolic Pathways of Omega-3 and Omega-6 Fatty Acids

Omega-3 Oils: The Essential Nutrients

MedlinePlus

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Ergo, I’m posting the non-Caucasian image of Jesus that hit the covers of Popular Mechanics in December of 2002.  The goal had been to establish the most historically accurate image of Jesus possible.  Of note is that Richard Neave, a retired medical artist from the University of Manchester in England largely directed the project.  The group used visualization techniques that were common for forensic and archeological projects.

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I thought this article, which can be found nearly all over the web and has no clear author, was worth posting.  When Science has it’s say, and if Santa is real, he’s much more impressive than any of us ever thought!  Other extreme forms of life are really no match:

“There are about 2 billion children (people under 18 in the world. However, since Santa does not visit children of Muslim, Hindu, Buddhist, or Jewish religions, this reduces the workload for Christmas Night to 15% of the total, or 378 million. At an average (census) rate of 3.5 children per household, which comes to 108 million homes, presuming that there is at least one good child in each. Santa has about 31 hours of Christmas to work with, thanks to the different time zones and the rotation of the earth, assuming he travels east to west (which seems logical).

This works out to 967.7 visits per second. This is easy to say that for each Christian household with a good child, Santa has to jump down the chimney, fill the stockings, distribute the remaining presents under the tree, eat whatever snacks have been left for him, get back up the chimney, jump into the sleigh, and get on to the next house. Assuming that each of these 108 million stops are evenly distributed around the earth (which of course we know to be false, but will accept for the purposes of our calculations), we are now talking about 0.78 miles per household; a total trip of 75.7 million miles,
not counting bathroom stops or breaks.

This means Santa’s sleigh is moving at 650 miles per second-3,000 times the speed of sound. For the purpose of comparison, the fastest man-made vehicle moves at only 27.4 miles per second and a conventional reindeer can run (at best) at 15 miles per hour. The payload of the sleigh adds another interesting element.

Assuming that each child gets nothing more than a medium sized Lego set (two pounds). The sleigh is carrying over 500 thousand tons, not counting Santa himself. On land, a conventional reindeer can pull no more than 300 pounds. Even granting that the “flying” reindeer could pull ten times the normal amount, the job couldn’t be done with eight or even nine of them Santa would need 360,000 of them. This increases the payload, not counting the weight, another 54,000 tons, or roughly 7 times of the Queen Elizabeth (the ship, not the monarch).

600,000 tons travelling at 650 miles per second creates enormous airresistance-this would heat up the reindeer in the same fashion as a spacecraft re-entering the Earth’s atmosphere. The lead pair of reindeer would absorb 14.3 quintillion joules of energy per second each. In short, they would burst into flames almost instantaneously, exposing the reindeer behind them and creating deafening sonic booms in their wake. The reindeer team would be vaporized within 4.26 thousands of a second, or right about the time Santa reached his fifth house on his trip.

Not that that matters, however, since Santa, as a result of accelerating from a dead stop to 650 miles per second, in .001 seconds, would be subjected to forces of 17,500 g’s. A 250 lb Santa would be pinned to the back of his sleigh by 4,315,015 pounds of force, instantly crushing his bones and organs and reducing him to a quivering blob of pink goo.”

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I’ve found in my sketching lately that the past semester has driven into me an even more intense way of observing my subjects.  Foremost is composition and page placement. Following that is proportions and the structure of the subject: overall proportions to measure against small proportions with my eye, and the drawing’s proportions to match these.  Form, planes, angles, and dimension all come into play.  Then there’s line weight to consider, the lighting to record, shadows and highlights.  Your eyes are jumping between the subject and the drawing – measuring, studying, and informing your hand what to do.

For the most part you’re working on one of these elements of the drawing and not the others, but it’s important to constantly be aware of how your lighting choices are affecting proportion, how form interacts with the whole composition.  It’s the constant battle of being highly involved with the mark being made at the present without losing awareness of how it’s changing the piece as a whole – a bit of a catch 22.  To add another analogy, you need to see the forest and the trees at the same time, and not crash into anything.  In the end, everything should interact gracefully.

To see some great observational drawing and painting in actiona, browse a blog I love that I only wished was updated more frequently: http://www.artdemonstrations.com/

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The first issue is simplest to tackle.  While it’s true there are a myriad of medical illustration images available online, it’s hardly true that everything is known about the body or that everything has been shown in every possible way.  It would be like saying all the music has already been composed or all the books written, and there isn’t a single thing to say that hasn’t been said before.  Micro and cell biology on it’s own is exploding as a field.  There are new entries and structures added daily to the invaluable Protein Data Bank, new designer drugs being tested, and new research on diseases.  These all need to be illustrated and visually clarified, for the benefit of other researchers, doctors, and the public.  Even in the field of gross anatomy, I know from my studies this semester that there are images that don’t exist yet that would helped greatly in understanding certain structures.

And as far as the assumption that photography – although a valuable field in and of itself – can take care of everything, you only need to realize that most of what goes on in the body happens at a microscopic level to understand why illustrators are still valuable.  As current technology and limits of science go, it really isn’t possible to record a video of a given pathway inside a cell.  Some aesthetic choices need to be used to really understand certain mechanisms.

But beyond the size and technology issue, there’s the larger idea that drawings are often more useful because they can show things in a way more fitting to how our brains see. Although there’s a panorama of details in our field of vision, we only really focus on one thing at a time.  Illustration (whether the end product is traditional or digital) can enhance some structures and downplay others; they can show things as accurately as they can didactically.  Fat can easily be eliminated, fascia transparantized, and vasculature ghosted.  What needs to be there is, and what isn’t critical to the artwork, isn’t.  Well researched and executed illustrations get to the heart of the image’s message well.

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As a note, all of the sketches were done with graphite on 9×12 sized paper, some bristol and others marker paper.

Left ventricle of heart

Small intestine arteries

Spermatic cord and testicle

Kidney and renal vasculature

Piriformis muscle and related vasculature

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