Monday, April 29, 2013

The actual reasons behind sickle-cell anemia

It's week 8 of my MIT Biology course delivered online via EdX.org, with the lectures by the highly-esteemed Eric S. Lander, director of the Broad Institute, a man largely involved in the recent Human Genome Project.

During weeks 6 and 7, there was a bunch of really cool things.

We had a long discussion (a few lectures) about hemoglobin, the protein that carries oxygen from the lungs and throughout the body. Well, the only protien worth mentioning under normal circumstances.
Most everyone knows that sickle-cell anemia is caused by defetive hemoglobin, which is sickle-shaped rather than the normal cell shape. But why is it defective? How? And what makes the sickle shape and why?

It turns out the answer is in the molecular biology of the human genome. The lecture explains what particular error makes the gene (that makes hemoglobin) defective, and how that error might occur. It then explains the molecular results of the error, which are simply a misalignment of negative charges. Those negative charges result in a string of hemoglobin proteins, which crystallizes into a rod which then shapes the sickle cell. Thus the visible shape of the diseased cells is a consequence, not a cause, of the disease.


Anyone with anemia should really get to watch these lectures. I really hate that the videos might not be readiy available online.

Another really cool thing I learned was why some viruses are especially awful and hard to get rid of, like HIV. These are called retroviruses, and as I understand it insert their destructive genetic material into the genetic code of the host, becoming an integral part of the cell and pretty much impossible to excise.

And then the lectures go on to explain things I had not learned in high school, but thought I had. I thought it was impossible to have a offspring have a phenotype unknown in their ancestry. Right after high school, I went so far as to explain to a Chinese friend that first generation Chinese children could never have blue eyes because there were no blue eyed genes in the Chinese parents (or even in a marriage between a Chinese and a blue-eyed Caucasian).

Turns out, its not as simple as I had been taught. Yes, what I had been taught was a good foundation, but it didn't address all sorts of genetic hanky-panky that can go on, such as recombinant DND and transposons.

After all this, there was yet more. I was especially intrigued by the "computer logic" of DNA and proteins. Many genetic sequences are like "switches" that turn on or off a specific gene under specific circumstances.

I gotta go watch another lecture.
Jolan tru.

meet the cat-legged armoured-croc-lizard

Here, I'm referring to another Triassic reptile, the aetosaurs, who are contemporaneous with the sheep-lizards and the pig-lizards mentioned before.
And just like the others mentioned, the aeotosaurs are easily confused with the dinosaurs.

To be quite frank, at a quick glance I don't blame anyone for confusing the two.

The aetosaurs are actually archsaurs, the same group as the rhychosaurs (pig-lizards). The archosaurs were a crocodile-like group who are ancestral to both crocodilians and dinosaurs both. Terms such as pseudocrocodiles and paracrocodiles have been mentioned. Sometimes their armor has been likened to the much later ankylosaurs (which I didn't know is grouped closely with stegosaurs, although I see why).

It's not entirely clear that the "armor" was used primarily for defense, nor is their cat-like posture universally accepted. These ideas are widely thought, however.

And since I am talking about Triassic fauna, don't forget the croc-sized salamanders and the early dinosaurs of this era, such aspisanosaurus. I think it's terribly funny that an especially small dinosaur was named 'pisant lizard', but as it turns out it is just a coincidence of the last name of a famous Argentine paleontologist was honored with his own dino.

Cool link about these guys:
http://chinleana.fieldofscience.com/2009/04/amazing-convergence-crustacean-vs.html

Tuesday, April 16, 2013

kaiju emotion

It is hard to convey distinct emotion in monsters, but I saw this photo of a diorama recently that did a very good job. Despite the fact that these are "real animals" represented, I think my use here is justified.

http://archosaurmusings.wordpress.com/2008/11/01/being-eaten-alive-arrrrrgggggghhhhhh/

http://archosaurmusings.files.wordpress.com/2008/10/rhyncho-herrera-model.jpg


Also, I have been impressed with art in the Kill All Monsters webcomic. Heck, the webcomic in general. They appear to have a published form for sale, but at the moment I am broke. And truth be told, I try to restrain my whimsical purchases.

meet the sabre-toothed sheep-lizard

(I'm not kidding)
The dicynodont was another Triassic animal, also known in other geologic eras.
(it goes PERMAIN -> MESOZOIC (Parts 123: Triassic -> Jurassic -> Cretaceous) -> CENOZOIC)

These are hardy fellows, having as a group survived the Permian-Triassic Extinction event, the Jurassic Ecologic Chaos, and the competition with the well-adapted dinosaurs. Their heyday was apparently in the early and middle Triassic, however, when they were as numerous as perhaps 95% of all land animals.

http://eonsepochsetc.com/Mesozoic/Triassic/Tri_Animals/Dicynodonts.html
http://www.abc.net.au/science/ozfossil/ageofreptiles/northern/dicynodont.htm
http://darrennaish.blogspot.com/2006/05/dicynodonts-that-didnt-die-late.html

Among other things, the dicynodonts are amazing as a survivor from the early Triassic to the early Cretaceous. They were once though to have all died out in the Triassic for various reasons.

meet the owl-headed pig-lizard

Rhynchosaurs were a group of reptiles that lived about 220 million years ago during the Triassic period. They're not considered dinosaurs, although neither are pterodactyls nor dimetrodons, although popular culture considers them to be such.
My readings recently in a book about dinosaurs has often mentioned the other non-dinosaurs with whom they lived, which is pretty cool to me.
http://en.wikipedia.org/wiki/Rhynchosaur
http://www.darwincountry.org/assets/userfiles/medium/sy2129.jpg

These triassic reptiles are considered to be archosauromorphs, a group ancestral to both crocodilians and dinosaurs. The archosaurs and archosauromorphs are generally crocodile-like, although some such as the rhynchosaurs were plant-eaters.

In this case, the rhynchosaurs are at least "distant cousins" to the dinosaurs. Other prehistoric fauna, such as giant amphibians and therapsids (mammal-like lizards who ruled the Earth before dinosaurs), are not really part of the extended dinosaur relations.

Doing a casual search on Google, I discovered a rather unexpected connection with Dungens and Dragons.

Friday, April 12, 2013

Recipes: Quick-n-cheap $7 Mac-N-Cheese

Quick-n-cheap $7 Mac-n-Cheese:
Dress to impress. I thought this name made a good description of the value, although I am now worried people might think it costs $7 to make. It is actually very very cheap, maybe $1.50 for 4 servings or a meal for myself. But also very important is how elegent and fancy this meal is. Regular Mac-N-Cheese doesn't impress anyone except little children.

All you need is one box of Mac-n-Cheese (Kraft or store brand works).
One half stick butter.
One box Stove Top Stuffing (maybe a store brand works)
Milk, salt, pepper are all optional.

You make the quick Mac-n-Cheese on the stovetope mostly like it says on the box, although use extra water to replace milk, and thus double water (unless you want to use milk, then follow box).

Once made, drain pasta if you need to (depending on how the box diretions are), and then mix in butter, cheese sauce packet.

Up to now you just have made plain old Mac the way the box says. Its ready to eat, but nothing fancy. Here's the fun part. Open up the box of stove top, and shake in pre-flavored crunch and herbs to taste. I would recommend about one fourth of the box and save the rest for later.

Voila!

Recipe: Fish Pie

I am going to be posting a few recipes, some I have made up myself, some from books, some I've tried with success but written by others. Next I'll post my Quick $7 Mac-n-Cheese, my Easy Supposedly Indian Soup and tried and true broccoli cornbread.

Fish Pie:
1 pound preffered fish
1 pint oysters
2 tablespoons capers
Sprig of thyme
3 Sprigs of parsley
1/4 pound butter
1 tablespoon vinegar
3/4 cup arichoke bottoms
1/2 pound mushrooms
4 hard-boiled eggs
1 1/2 cups mutton gravy
Salt and pepper
Pastry

Fillet of sole makes a delicious pie. It should be poached in court bullion for eight miinutes and then cut in strips. Add to it the oysters, which have been set on the fire to simmer until the edges curl. [Add] the capers, thyme, parsley, artichoke bottoms, eggs cut in eighths, mushrooms which have been sliced and cooked gently for ten minutes, salt and pepper. Add the vinegar to the gravy and moisten the fish mixture with it. Line a deep dish with pastry and dot with half the butter. Fill with the mixture and add remaining butter. Cover with a top crust of puff paste and bake until a golden brown.