E2science

Tetrahydrogestrinone, also known as THG or less technically The Clear, is an anabolic steroid chemically similar to gestrinone and trenbolone. THG is a potent agonist for androgen receptors, estimated to be at least 10 times as potent as the comparable steroid trenbolone, meaning that it builds muscle and burns fat extremely quickly at very small dosages (about 5mg or "just a few drops under the tongue"). Unfortunately for the people using it, it is also an extremely potent agonist for progesterone receptors, so it's also likely to halt natural testosterone production, leading to significant side effects.

It was invented by Patrick Arnold in the late 1990s with funding provided by Victor Conte's company, Bay Area Laboratory Co-operative. BALCO was a legitimate distributor of dietary supplements on the surface, but was also involved in the distribution of various illegal steroids to professional-level coaches and athletes. THG was intended to be another one of their designer drugs, which could be used by athletes to increase physical performance while still fooling anti-doping tests. It worked for a while until a disgruntled Trevor Graham, sick of being beaten by BALCO-enhanced players, sent a sample of the drug to the U.S. Anti-Doping Agency. Within a few years the USADA developed a test that responded to THG, limiting its usefulness and effectively removing it from the professional sports scene. It was classified as a Schedule III controlled substance by the Food and Drug Administration in 2005.

Although inventions like THG have landed him in prison a few times, Patrick Arnold insists that what he does is admirable. He was bullied at a young age due to his "nerdy" obsession with chemistry, and as a result became obsessed with self-improvement. During high school he worked out extensively and created his own protein bars, but was frustrated by the lack of visible muscle mass. After sampling steroids for the first time in university, he devoted his life to creating what he calls "performance enhancers", and insists that his drugs have been "given a bad rap". Most people disagree.

[S]ome steroid precursors are clearly outside the scope of the dietary supplement definition and are subject to regulation as drugs because they are intended to affect the structure or function of the body. For example, FDA considers tetrahydrogestrinone ... a new drug under [the Food, Drug, and Cosmetic Act]. Our analysis demonstrates that this is a purely synthetic, non-naturally occurring, highly potent anabolic steroid. It is a designer steroid in the truest sense. --John M. Taylor, Associate Commissioner for Regulatory Affairs

Notable athletes who have abused tetrahydrogestrinone include Barry Bonds, Jason Giambi, and Dwain Chambers. Tim Montgomery and Marion Jones have lost medals over their use of THG.

The media frenzy created after the discovery and listing of THG went down in history as the BALCO Scandal. The scandal caused Major League Baseball to strengthen its policy against performance-enhancing drugs and, obviously, destroyed BALCO as a company. However, Victor Conte has since founded a new company called Scientific Nutrition for Advanced Conditioning, which allegedly does not deal illegal drugs like his old company did.

Sources

1. http://www.steroid.com/the-clear.php
2. http://sportsillustrated.cnn.com/vault/article/magazine/MAG1104278/1/index.htm
3. http://www.fda.gov/NewsEvents/Testimony/ucm114985.htm

Along with a traditional Roux-en-Y operation, other variations are options for patients suffering from morbid obesity. Staples can be applied to the stomach to reduce its effective volume, so that the patient feels satiated with a lower food volume. An advantage to this type of surgery is that it takes less effort to reverse.

A Roux-en-Y operation requires severing the upper and lower portions of the stomach to create a bypass. Normally food enters follows the following path:
esophagus >>> fundus of stomach >>> stomach >>> pyloric sphincter >>> duodenum >>> jejunum >>> ileum >>> large intestine.
after the Roux-en-Y, food will usually follow this modified path:
esophagus >>> fundus of stomach >>> jejunum >>> ileum >>> large intestine.

bypassing the stomach and duodenum serve two important purposes when trying to reduce a patient's weight. First, the effective volume of the stomach is reduced, so its fills sooner. The fundus also contains barorecptors that signal a patient when they are satiated. The baroreceptors are positioned at the top of the stomach, so that they activate when the stomach fills. Secondly, food will bypass the duodenum, which absorbs the most nutrients while food normally passes through the GI tract. This double-edged attack reduces both the total amount of food consumed, and the amount of nutrients absorbed.

While the Roux-en-Y procedure is effective, it is difficult if not impossible to reverse and requires the patient to live with the condition for the rest of their lives. It can also have unpleasant side effects from the reduced absorption of nutrients.

A relatively new technology are implants that alter effective stomach volume or change the way food is digested within the GI tract. These do not require restructuring of the GI tract, and can be removed after the patient has reached a healthy weight.

One category of implants reduce the stomach by squeezing it into a smaller volume. Known as "lap-band surgery," this type of implant surrounds the stomach with an inelastic cord. Some versions use an inflatable tube, something like an inner tube in a car tire. A computer-controlled pump can inflate or deflate the band to varying degrees, to adjust the effective stomach volume.

Another category of implants produce an artificial feeling of satiety by expanding within the stomach. Wire scaffolding, somewhat like expandable intravascular structures used to counteract atherosclerosis in cardiac vessels is placed in the stomach and holds it open to simulate the presence of food.

Another type reduces the absorption of nutrients from food passing through the GI tract by physically isolating it as it travels through. Frequently, a tube is placed within the GI tract starting at the gastroesophogeal junction, passes through the stomach and downstream into the small intestine. The tube can be permeable, to allow digestive secretions from the stomach to enter the lumen of the implant but not exit until they reach a downstream opening. This way, food travels along its natural pathway but does not interact with enzymes to extract nutrients.

In a reverse of this method, some implants isolate digestive secretions such as bile by coupling to the ampulla of vader and isolate them from food in the small intestine until they reach a downstream segment or the large intestine. this way, nutrients do not get a chance to be absorbed by the more effective duodenum, and leave the body.

One major advantage to these types of implants is that the surgery is reversible. To return a patient's GI tract to its previous condition, a surgeon can detach the implant at its anchor points, and remove it endoscopically. An incision in the abdomen is not required, since all the manipulations can be performed with an endoscope through the esophagus. Some implants are made of biodegradable materials, and are designed to pass through the GI tract after a set period of time.

While gastrointestinal bypass surgery and implants offer a solution to morbid obesity, they are only used as a last attempt when changes in diet and exercise have failed.

Middle ear infections (otitis media) are so common that 75% of all toddlers have had at least one by their third birthday. Some children are constantly plagued by this most common of all childhood illnesses and may need surgery to install tubes in their ears or to have their adenoids removed. Others may suffer from high fever, ruptured eardrums or hearing loss that can hurt their ability to learn to talk and understand new words.

Otitis media is a very old human ailment; examinations of 2600-year-old Egyptian mummies show evidence of perforated eardrums and damage to the mastoid bone (the bulging bone behind the ear) from infection spreading into the skull. Such skull infections were common in the days before modern antibiotics. In 1932, purulent otitis media accounted for 32% of all the admissions to Bellevue Hospital in New York City.

My own father suffered from such an infection when he was a little boy; when he had a raging ear infection, the doctors wrapped him in a sheet and stuck a long, skinny knife into his ear to pierce the eardrum and release the pus and pressure. This was completely without anaesthesia, of course. Eventually he had to have part of his mastoid removed. He still has a deep scar behind his ear.

There are two types of otitis media:

1. acute otitis media: (AOM) The interior of the ear and the eustacian tubes are infected and swollen, and mucus and fluid are trapped inside the ear. This is often very painful, but a few children experience no pain.
   
   
2. otits media with effusion (OME): in this condition, fluid stays trapped in the ear after the infection is over. This can cause hearing and balance problems and also provides a fertile ground for new infections.

Children are most at risk of developing ear infections because their immune systems are not fully formed and because their eustacian tubes are shorter and angled in such a way as to make them get clogged with mucus more easily.

But ear infections may soon become a thing of the past.

Scientists are working on developing safe vaccines against the bacteria that commonly cause ear infections. Such bacteria include:

• Moraxella catarrhalis
• Streptococcus pneumoniae
• Staphylococcus aureus
• Haemophilus influenzae

One bad bug researchers at Children's Hospital in Columbus, OH have targeted is Haemophilus influenzae. In addition to ear infections, it can also cause pneumonia and, rarely, meningitis (an infection of the covering of the brain).

So, a vaccine against H. influenzae and its kin could give infants a powerful dose of protection to keep them healthy throughout childhood.

One vaccine is already on the market. Prevnar, which was approved for use in the U.S. in 2000, protects children from Streptococcus pneumoniae bacteria. Such pneumococcal bacteria are common culprits behind ear infections (like H. influenzae, they can also cause meningitis). Nobody knows when the other vaccines will be ready, but parents can help protect their children in the meantime.

If you have a baby, breastfeed him or her if you can. Infants get antibodies from their mothers' milk that defend against infections. Conversely, there has been some indication that formula in bottles can become easily contaminated with bacteria that then reinfect children drinking from them. Babies who get ear infections in their first year are most prone to chronic infections later because they tend to develop a colony of bacteria in their throats that doesn't go away easily.

Keep a close watch on your children's health. Don't let people smoke around them, because smoke can damage the delicate membranes of children's throats and ears and give bacteria a foothold to grow. If your child complains of ear pain, seems to have balance problems, or if your toddler is crying and pulling at his or her ears, take your child to the doctor as soon as you can.

If your doctor gives you antibiotic medicine for your child, make sure you and childcare providers know when to give doses. The type of antibiotic and treatment depends on whether the infection is acute or recurrent and on what type of bacteria are the cause, but children will often need to take antibiotics for 10-14 days to fully clear up an infection.

Make sure your child finishes all the medicine. Some children may need treatment up to two weeks, and they may look and feel better before the medicine bottle's empty. If you stop giving them their medicine too soon, bacteria lurking in their systems could come back stronger than ever before (and newly-resistant to the antibiotic your child was taking).

Until more vaccines are ready, prompt and complete antibiotic treatment is the best way to ensure that your child doesn't suffer from ear infections again.

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References:

http://www.nicd.nih.gov/heathl/parents/otitismedia.htm
http://www.ccri.net/ccri/
http://www.research.buffalo.edu/quarterly/vol09/num04/n2.shtml
http://www.utmb.edu/otoref/Grnds/

A Liter of Light is a project aimed at providing poor homes in developing (and not so developing) countries almost no-cost daytime light.

It is carried on mainly in the Philippines by MyShelter foundation (with government funding for the materials), and it's based on the work done by students at the MIT under the concept of appropiate technologies, which was in turn based on what Brazilian engineer Alfredo Moser did in 2002 to be able to keep working in his workshop during power shortages.

The Concept

The concept behind the project is so straightforward you won't believe it: transparent plastic (water or soda) bottles filled with purified or distilled water and bleach. That's it. Oh, well, and some holes in the roof.

The preparation and installation of these so-called solar bulbs consists of three main steps, explained at a zillion places, including the project's homepage:

1. Making a circular hole in a square piece of galvanized iron sheet matching the shape of the roof, making half the bottle go through it, and sealing the borders so as to avoid leaks.
2. Cleaning the bottle and filling it with distilled/purified water and bleach, and sealing its cap.
3. Cutting a hole in the roof and putting the sheet with the bottle over it, so that half the bottle is inside the house and the other half remains outside. Then fastening it with rivets.

(This is a quick and dirty run-down, if you are planning to actually do it refer to the real instructions, which were written by people who - I hope - know what they are doing).

"And why not just cut holes in the roof and cover them with some transparent sheet of something?" You may be wondering, like I did at the beginning. The answer is by doing this you get a greater spread of light across the room, similar to that obtained by using a lightbulb.

It blinds me with its science

As simple as it is, the project relies heavily on physics and (bio)chemistry.

The innocent water-filled bottle behaving much like a 50-60W incandescent lightbulb is made possible by two optical phenomenons: refraction (described by Snell's Law) and total internal reflection.

Refraction happens when a ray of light passes from a medium with a certain refractive index to another medium with a different index (air and water in this case), and its angle of incidence is different than 90º and 0º.

Total internal reflection occurs when light tries to pass from a medium with a higher refractive index to a medium with a lower one, and its incidence angle is greater than a certain angle called critical angle.

These two phenomenons combined make the light inside the bottle feel utterly confused, and it ends up going out in all directions.

As for the chemistry involved, NaClO, the active ingredient in bleach, prevents the growth of mold in the internal surface of the bottle, hence keeping it clear.

NaClO dissociates in water forming sodium cations (Na⁺), hypochlorite ions (ClO^-) and hypochlorous acid (HClO). Hypoclorite ions and hypoclorous acid are thought to be capable of destroying the membrane and cellular proteins, and to interfere with the cellular metabolism of mold.

What's cool about it

• Even if it only works during the day, it can prove to make a huge difference in lighting conditions of otherwise unilluminated rooms.


• It reduces the probability of fires caused by defective electrical wiring, which are way too common in precarious homes.


• It saves some money in the power bill (which can be a lot to families that take advantage of this technology) and has a negligible carbon footprint.


• Each solar bottle costs nearly nothing to make, between $2 and $5, and has a lifespan of about 5 years.


• It creates jobs, which despite being perhaps temporary, may help many people (like Solar Demi, the guy that appears in the project's official ad) in poor countries.

What's not cool about it

• As these bottles don't store energy, they are only effective during the day.


• The roof has to be made of metal, and you have to be willing to cut a hole in it.


• If you happen to arrive from a party in the morning and want to get some sleep, you won't be able to. Unless you devise a way to cover the damn thing without much effort.


• It looks like a permanent temporary solution for poor people to use in their single-room fragile and almost subhuman homes while the rest of us carry on with our comfortable and wasteful way of life.

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References

Liter of Light Homepage

Solar Bulb Out of One Liter Water and Bleach

Q: How does bleach kill mold?

Solar Bottle SuperHero @ Physics Central

Snell's Law

Total internal reflection

It's been a while since I took physics so let's see how well I do:

The Oberth Effect is the observation that the total kinetic energy imparted by a rocket is greater when the rocket is moving at higher speeds. In simpler terms, a rocket engine is more efficient at harnessing the energy in its fuel when it is moving faster.

At first this seems counter-intuitive—force is force, right? The rocket should provide the same change in velocity no matter how fast it's going. However, we can prove it conceptually by centering the frame of reference on the rocket. If the rocket fires at the apoapsis of its orbit—the point furthest away from the body it's orbiting around and the point where the rocket is moving the slowest—you get a certain change in velocity based on the thrust. Now imagine the rocket moves towards periapsis, the closest and nearest point. As it moves towards the object, the rocket picks up speed due to gravity, following Newton's Second Law of Motion: force = mass X acceleration (in this case, gravity). If the rocket fires its engine at periapsis, not only does it get the thrust from burning the propellant itself, but it also reduces its mass so when it starts climbing back to apoapsis, the force of gravity is smaller than it was before. This means that its apoapsis will rise because it will take longer for gravity to counteract the rocket's velocity.

Not only that, but because the rocket was carrying that propellant on the fall down to periapsis, it got a little extra velocity in the fall. So the rocket is gaining energy from the propellant just by falling into a gravity well because the potential energy of the propellant is being converted into kinetic energy as it falls. By burning the propellant at periapsis instead of apoapsis, not only did the rocket gain the velocity in the chemical bonds of the fuel but it also stole a little bit of its kinetic energy too.

To prove it mathematically is a different exercise. We start with the mathematical definition of work (which in this case is a stand-in for kinetic energy): E (work or kinetic energy) = F (force) * S (distance traveled). From this it's fairly intuitive that if you increase the distance over which you apply the force, you also increase the total amount of energy imparted, despite keeping the force constant.

With a little calculus you can get a more literal explanation of the phenomenon. By differentiating the equation for work, we can calculate the instantaneous rates of change in each of the variables:

 dE  = F *  dS      (Since we're holding F constant, it is a constant factor and so is not differentiated)
 dt         dt    

In words, that equation says that rate of change in energy = force * rate of change in distance (velocity). Again, you can see that the energy imparted depends on the velocity, even if force remains constant.

This effect has obvious applications to space travel as it allows a spacecraft to get different amounts of delta-v from the same fuel depending on the rocket's speed and location. If a spacecraft's journey is planned to always take advantage of this effect, you can actually design it with less fuel than you'd nominally need to travel that far/fast, freeing up weight for instruments and other devices. The greatest gain in velocity due to the Oberth effect occurs on close approaches to gravitational bodies in a powered slingshot maneuver, a variation of a gravity assist. As a spacecraft approaches the planet/moon/star, the gravitational potential energy stored in the mass of the fuel begins to be converted into kinetic energy. If the spacecraft fires its rocket at closest approach, it has gained kinetic energy not only from the chemical energy of the fuel but also from the potential energy that was released as it fell toward the body. Since the closest approach is also when the spacecraft is moving the fastest, the Oberth effect adds additional energy to the spacecraft (by taking it away from the fuel). Finally, since burning fuel also reduces the mass of the rocket, the resulting velocity is greater due to the conservation of momentum.

ScienceQuest 2012

Sources:
http://en.wikipedia.org/wiki/Oberth_effect
http://www.projectrho.com/rocket/mission.php#id--Oberth_Effect
http://clowder.net/hop/railroad/Oberth.html For some diagrams way over my head.
http://en.wikipedia.org/wiki/Constant_factor_rule_in_differentiation And because I've completely forgotten everything about calculus by now.