Conjoined Twins: What went wrong?

My cousins are identical twins. I actually wasn't able to tell them apart until they were 17.

Identical twins share more than their matchy-matchy outfits. Identical twins, or monozigotic twins, start as one fertilized egg, which later splits into two. This causes their DNA to be the same. Two exact copies.

So where does it go wrong for conjoined twins?

In the case of conjoined twins, a woman only produces a single egg, which does not fully separate after fertilization. The developing embryo starts to split into identical twins during the first few weeks after conception, but stops before the process is complete. The partially separated egg develops into a conjoined fetus.

Abigail and Brittany Hensel, born March 7, 1990 in Carver County, Minnesota, United States of America, dicephalic conjoined twins, two heads, two arms, two legs, cannot be separated.

About 40 to 60 percent of conjoined twins are still born, they die during birth. And, for some reason, female siblings seem to have a better shot at survival than their male counterparts. Although more male twins conjoin in the womb than female twins, females are three times as likely as males to be born alive. Approximately 70 percent of all conjoined twins are girls.

Surgical separation is tough one. Doctors need to see which organs the conjoined twins share. Also, the difficulty level rises depending on where the twin is joined. For example, twins joined at the sacrum at the base of the spine have a 68 percent chance of successful separation, whereas, in cases of twins with conjoined hearts at the ventricular (pumping chamber) level, there are no known survivors.

Although success rates have improved over the years, surgical separation is still rare. Since 1950, at least one twin has survived separation about 75 percent of the time.

Even after survival of surgical separation, twins will have to undergo intensive rehabilitation because of the malformation and position of their spines. The muscles in their backs are constantly being flexed and they often have a difficult time bending their backs forward and backwards and sitting up straight.


Source: http://www.umm.edu/conjoined_twins/facts.htm

Omnipresent Corn

I've loved corn since I was a kid. In Mexico, when you bought corn, it most of the time came with a green corn worm. My brother and I loved the worms, it was a cute pest! We probably enjoyed playing with the worm as much as eating the corn.

Corn is a staple in many families' dinners all over the world, and corn is good. It has vitamin C and A, iron, and fiber. But what about when it stops being a whole food? Oh no... we get corn syrup and high-fructose corn syrup.

Credit: Natalie Dee

Corn syrup is everywhere. Why? Because it's a cheap and serves multiple purposes: thickener, sweetener, and humectant (an ingredient that retains moisture and thus maintains a food's freshness). In the United States, cane sugar quotas raise the price of sugar; hence, domestically produced corn syrup and high-fructose corn syrup are less expensive alternatives that are often used in American-made processed and mass-produced foods, candies, soft drinks and fruit drinks to help control cost. In a nutshell, using corn syrup instead of sugar lower expenses, therefore raising company's profits. Companies main purpose is t make money, but it's sad when it takes a toll on people's health.

Corn is also fed to cows and other livestock, because (as I learned in Food, Inc.) it's cheap, fattens the animals quickly. and allows for year round beef production in colder climates. The fatter corn fed cows have a more marbled meat than grass fed cows and this is what the consumer in today’s beef market has come to know as the standard.

Though “corn finishing” produces bigger, fatter cows in less time, corn is not a natural diet for a cow. Because of this unnatural corn rich diet, some unhealthy side effects take place. Most notably, a higher incidence of E. coli O157:H7 occurs in corn fed beef than in grass fed beef. In 1998, a Cornell University study revealed that cows fed on a natural grass diet had at least 80% less E. coli O157:H7 than grain fed cows.

http://www.nbafoodadvocate.com/corn-fed-cattle-bigger-cows-bigger-e-coli-threat-more-foodborne-illness-1177

Food, Inc.

Old MacDonald had a farm,
Ee i ee i oh!
And on that farm he had some genetically modified chickens,
Ee i ee i oh!

Today during Lab we watched the movie Food, Inc. I really liked it, it made me feel glad that I'm a vegetarian, but it still left me a bit very freaked out. It portrayed companies as evil corporations who only care about profit and not about the health of it's consumers.

One of the many things that made me feel a bit sick were the chicken scenes. I felt disgusted when they showed the difference between a genetically modified chicken and a normal chicken. The birds were given antibiotics and couldn't even move and sat in their own feces for their entire 45-day-life. How about some KFC for lunch?! :]

It also showed how the food industry affected low income families. They work a lot and it's easier and cheaper to eat fast food than go to the supermarket, buy whole foods, go home and cook them. This same issue also leads to obesity and diabetes. Why would a family buy vegetables and cook a nice meal, when they can get a burger for a $1? Instant gratification.

Commodity crops: corn, wheat, and corn, where also mentioned in this film. They are in almost everything.

I enjoyed this eye-opening film, and I wish everyone could have chance to watch it. Maybe it wont make people become vegan or vegetarian or organic eaters, but it will definately make them aware and they'll see the story behind their dinner.


http://www.foodincmovie.com/img/downloads/Press_Materials.pdf

Cancer Immunity

Naked mole rats are special. They have an "immunity" to cancer. Or at least a high resistance to it as scientists haven't found evidence of it. These hair-less rodents live up to 28 years, which is the longest for any rodent.

Biologists at the Unversity of Rochester believe they have found the reason. The findings show that the mole rat’s cells express a gene called p16 that makes the cells “claustrophobic,” stopping the cells’ proliferation when too many of them crowd together, cutting off runaway growth before it can start. The effect of p16 is so pronounced that when researchers mutated the cells to induce a tumor, the cells’ growth barely changed, whereas regular mouse cells became fully cancerous.
The reason, the researchers discovered, is that naked mole rat cells rely on two proteins--named p27 and p16--to stop cell growth when they touch, whereas human and mouse cells rely mainly on p27. "They use an additional checkpoint," says Gorbunova, whose study appears in the Proceedings of the National Academy of Sciences (PNAS). The additional level of protection may explain how the rodents remain cancer-free for their entire lives.


Sources:
http://www.neatorama.com/2009/10/27/naked-mole-rats-immune-to-cancer/
http://www.the-scientist.com/blog/display/56123/
http://news.sciencemag.org/sciencenow/2009/10/26-02.html

Wrinkly fingers and toes.

Everyone's experienced this: After taking a bath or a long shower, our fingers and toes get wrinkled.

What causes this? One word: osmosis. Osmosis is the movement of water across a membrane from high concentration to low concentration. In this case there is a higher concentration of water in the bathtub than in your skin.

So then why is it that only our fingers and toes get wrinkly, but not our arms or legs? This is because our skin has a layer of waterproof keratin on the surface, preventing both water loss and uptake. On the hands and feet, especially the toes and fingers, this layer of keratin is continually worn away by friction. Water can then penetrate these cells by osmosis and cause them to become wrinkled.

Low Iron in Vegetarians: Lentils

Two years ago, when I decided I wanted to become a vegetarian, my mother's main concern was how I would make up for the nutrients I would miss out from animals. I'm not a picky eater, so maintaining a well balanced diet is not hard for me at all: I love all kinds of vegetables, fruits, and legumes.
One of my favorite legumes are lentils. These legumes are insanely high in proteins, including the essential amino acids isoleucine and lysine. Lentils are deficient in two essential amino acids, methionine and cystine, however, sprouted lentils contain sufficient levels of all essential amino acids, including methionine and cystine.
Lentils are actually one of the best vegetable sources of iron. This makes them an important part of a vegetarian diet, and useful for preventing iron deficiency.

And yet another great thing about this legume is that it's cheap, so it is a relatively good substitute for those who can't afford meat.

Cockroaches and Junk Food

Cockroaches are known to live anywhere, and surviving eating anything.But just like people, roaches on a junk food diet don’t fare well. According to one study, even cockroaches get fat and unwell when their diet is less than healthy.

Researchers at the University of Exeter, in England, fed one group of young roaches a well‑balanced diet of high‑protein fish food and oatmeal. A second group dined only on fish food–which in the roach world is the equivalent to a diet consisting mainly of burgers and fries.

Overall, the roaches raised on a poorly balanced diet were fatter and took longer to mature than the insects that enjoyed a more healthful diet. Even when some junk food‑eating roaches were switched to the more healthy diet midway through the experiment, they still weren’t as healthy as roaches that ate healthful meals from the beginning.

Similarly, another similar British study found that baby crows that scavenge junk food from city garbage cans are less healthy than crows in rural areas eating more natural, healthier stuff.

So why should we care about the diets of cockroaches and crows?

We already know that too much junk food is bad for our health. But learning that it’s unhealthy even for animals supposedly able to thrive on just about anything, well that drives the point home just a little bit more. If roaches and crows suffer from a poor diet, we’re all the more vulnerable.

http://mblogs.discovermagazine.com/discoblog/2009/07/07/small-comfort-cockroaches-too-get-fat-on-an-unbalanced-diet/
http://www.esajournals.org/doi/abs/10.1890/08-0140.1

The Truth About Hand Sanitizer

I know I'm not the only person who carries around a bottle of hand sanitizer. And since the H1N1 scare, there are hand sanitizers dispensers all over the school. But does it really make a difference?

Hand Sanitizer vs. Soap and Water
We are sold this product (hand sanitizer) with the claim that it can replace hand washing. But what we ignore is that this should only be so in situations when there is no water and soap available. The Food and Drug Administration, in regards to regulations concerning proper procedures for food services, recommends that hand sanitizers not be used in place of soap and water but only as an adjunct.

This basically says that even though it may somehow help (and it is better than not washign hands at all), hand sanitizer is not fully effective when it is used on it own.

Kills 99.9% of Bacteria
This statement is mostly untrue. Manufacturers of these products can continue to claim that the sanitizers are up to 99.9 percent effective in killing germs because they were tested on inanimate surfaces rather than human hands.

Manufacturers perform the germ killing test on a inanimate objects, such as tables, and chairs. The human hand though is complex, a warm, living surface that is much more vulnerable to germ growth and attack. These manufacturers also perform these experiments in controlled situations with constant variables. Daily life is not controlled, and so is susceptibility to germs. If these tests were to have been conducted using live humans, the %99.9 claim would have to be removed.

"The physiological complexity of human skin makes
it very difficult to use for testing of this nature,"
Almanza (Barbara Almanza, associate professor of
restaurant, hotel, institutional and tourism manage-
ment) says. "The most clear and consistent results
were going tocome from using surfacesfor which the
variables can be controlled, and that's just not real life.
Real life is not neat and tidy."

Is it really necessary to strip bacteria from skin?
Actually, you can't fully kill all bacteria from the skin. Researchers have discovered that there are at least 250 kinds of bacteria that live on our skin. Some of the kinds they found were completely unknown.

Bacteria are natural, even necessary in human bodies. There are more bacterial cells in the human body than human cells. Not all bacteria are bad for you. The bacteria in our bodies are there for a reason. For example, bacteria in our intestines are important for digestion. It’s likely that the bacteria on our skin play important roles in keeping skin soft and enabling it to do what skin is supposed to do.

Conclusion
So why is hand sanitizer popular? Maybe because we’re obsessed with cleanliness, though it’s impossible to completely rid the skin of bacteria, and in any case it wouldn’t be a good idea to try.

There’s evidence that the bacteria that live in, and on us. They help protect us from microbes that do cause infections. Getting rid of our natural bacteria could pave the way for harmful bacteria to move in.


http://biology.about.com/gi/o.htm?zi=1/XJ&zTi=1&sdn=biology&cdn=education&tm=46&f=10&su=p897.8.336.ip_&tt=2&bt=0&bts=1&zu=http%3A//news.uns.purdue.edu/UNS/html4ever/000211.Almanza.sanitizers.html
http://hubpages.com/hub/Hand-Sanitizers-The-Real-Truth

Pequin Peppers

Today during Lab we "dissected" peppers and we got to see what makes them spicy: capsaicin. We also learned that the smaller the pepper, the higher concentration of capsaicin it will have.

Which brings me to pequin peppers. My grandma brings us pequin peppers from the Sierra of Chihuahua, and they're really spicy. They are tiny , but just one will make you food spicy enough (sometimes more than enough). They have a rating of 30,000-60,000 units in the Scoville scale, which is a scale that measures the spicy heat of a chili pepper according to its capsaicin content.