Monday, April 13, 2009

Media's Role in Performance-Enhancing Drugs

Our society has become a media-driven one in which people seem to be influenced by what they see in television. The media dictates and reinforces acceptable social norms and behavior, which has created a huge problem in terms of performance-enhancing drugs. Entertainment, news, and advertising are three aspects of television that play a role in shaping the way people view our society. In the entertainment aspect, people watch television and see attractive-looking people with great bodies while they’re lifting weights or in a pool, which influences people into wanting to be like that. Seeing attractive people motivates viewers into purchasing supplements even if they don’t know anything about them. In the news, there are so many reports of so many athletes, famous and non-famous, who use performance-enhancing drugs. The reports may say how the athletes are getting punished for using performance-enhancing drugs, but they also may mention that there are many athletes who don’t get caught. Athletes, especially young ones, see this and thing to themselves that if professional athletes can get away with using performance-enhancing drugs and make millions of dollars, then they can do it too, which creates many problems. In advertising, supplements use men and women with ripped bodies and words that attract people like “10 pounds of muscle in just weeks.” People believe in this and don’t find the need to research what they put into their bodies. This becomes a problem for the health of people who are influenced by these three things and a problem for society.

Unfamiliar Terms:
None

I love this article, because it is very educational and it helps people understand the motives behind what they see in television. When people watch television, they are so unconscious about what commercials and advertisements are trying to do. They are trying to convince people to purchase the products by influencing them using words and images that are attractive and it works. It’s not even just television. I subscribe to Men’s Health Magazine and I have learned that supplement companies are in contract with magazines and they both profit off of each other, but I wouldn’t have known this without reading and educating myself about something like this. Athletes, especially young ones, need to get educated about performance-enhancing drugs so that they don’t make decisions that will affect their health negatively.

Blechman, Robert K. Performance Enhancing Drugs. 31 Jan. 2008. 27 Mar. 2009 .

Thursday, April 9, 2009

Diamonds Are a Girl's Best Friend!

Diamonds Are a Girl’s Best Friend!
The formation of diamonds occur deep underground in the earth’s mantle under extreme pressure and high temperatures on carbon containing materials. These diamonds are natural uplifted by volcanoes that have erupted. Diamonds that are man-made are also created by using carbon containing materials under high temperatures but are inserted in such molten metals as nickel and iron. The diamonds will crystallize or form crystals inside the molten metals because they are more stable at higher temperatures. A pure and genuine diamond has no color and if a diamond does have a color it is due to an impurity such as a mixture with another substance. The colors we can see on a diamond are a reflection of lights around it. The diamond absorbs the lights, which are then internalized and dispersed as different hues or colors. Although diamonds absorb and reflect light easily they do not conduct electricity very sufficiently. They remain very cool and can be tested for their authenticity by this.

Crystallize- to form crystals

Molten- changed into a liquid form by heat

Graphite- a soft dark carbon that conducts electricity, occurs naturally as a mineral, and is also produced industrially. Use: batteries, lubricants, polishes, electric motors, nuclear reactors, carbon fibers, pencil lead.

Interconvert- the mutual conversion or two or more things

Diamonds have very distinct and distinct characteristics which probably makes them so valuable in the world. Synthetic diamonds seem as though they would not be as valued as naturally occurring diamonds, which leads me to wonder if the marketing for each are different. I also question what they do with impure diamonds. Their ability to reflect up to one sixth of the surrounding light, which gives it a very appealing look. What can I say that is probably why they are a girl’s best friend!

Baird, C., The Formation and Color of Diamonds, Chemistry in Your Life 2nd Ed.,W.H. Freeman and Company, 2006. P. 195-196.

Recycling: Not as Beneficial as We Thought?

Recycling turns out to have it's own environmental problems. According to Baird, landfills are reaching their maximum levels and most countries are opposed to burning the excesses. Some countries have even started to hold legal responsibility to companies for the recollection and recycling of the packaging of their products.

Resistance to recycling comes mainly from the plastics industry. They argue that unused plastic material is cheaper to produce than it is to prepare used plastics for recycling. Contrary to this, environmentalists argue that the plastics industry does not factor in the environemental costs into their price projection of recycling the plastic. They also note that burning some plastics releases more toxic organic compounds and hydrogen chloride (HCl) gas, which readily dissolves in water, can be extremely damaging to human health.

Developed countries utilize recycling abundantly. The most commonly recycled plastics are HDPE, LDPE, and PET. In the late '90s, nearly half of people living in urban areas recycled with programs providing curbside pickup.


So with all this in mind, is recycling still beneficial? Is it something that will help us in our attempts to become more earth-friendly? These are just some of the questions that arise from this reading. There are issues that we must learn to deal with and adapt our methods in order to effectively combat the damage that has already been done.


Baird, Colin. The recycling of plastic is a controversial topic. Chemistry in Your Life. 2nd ed. New York: W. H. Freeman, 2006: 190-91

Smokers Beware of Radon

Although radon may not be as dangerous as some people believe it to be, combined with cigarette smoking, it can be lethal. In the mid 1990’s, 22,000 people died of lung cancer per year. About 14% of these deaths were related to radon exposure indoors. 90% of the people exposed to the radon were also smokers. This led the U.S. National Research Council to conclude that although radon is dangerous under any conditions of exposure, it’s especially dangerous if someone smokes in addition to this exposure. Radon is detected through home test systems that identify large amounts of radon in the basement. Once the radon is revealed, homeowners can either seal off their basement from the rest of the house or re-route the air circulation in their house. Only about 7% of houses in America actually contain high levels of radon. Often times, homeowners in America never notice the radon in their homes since Americans move homes so frequently. Likewise, once they discover the radon they are more likely to move anyways rather than do anything to stop/prevent the problem.
In my opinion, since you never know when you are or are not going to be exposed to radon, more or less you should just not smoke! Only 14% of the deaths of lung cancer were related to radon. Thus we can consider the possible explanation that the remaining percent of people with lung cancer must have contracted it some other way, for instance, through smoking. Another curious thought is: how do scientists know if someone has been exposed to radon or not? Once someone has died, where is the proof that a person was or was not exposed to radon? It’s not as if a track record of homes with radon follows a person around through the duration of his/her life. Also, what about people who were exposed to radon but had no effects from it? The people who were exposed to radon and never suffered a consequence would go completely under the radar as far as exposure. Therefore, while some scientists can easily say and prove that 90% of people who died of radon exposure also smoked, what about the amount of people who smoked and were exposed to radon poisoning but never developed any problems? Or even the people who were exposed to radon alone also never developed any sort of conditions? Therefore, based on these questions that have been left open, further research needs to be conducted in order to study the correlation between being medically affected by radon and smoking.



Baird, Colin. “Is radon dangerous to our health?” Chemistry In Your Life: Second Edition. W.H. Freeman and Company, New York. 2006. P. 631

Breakfast at Tiffany's

Summary:

Diamonds are created 150-200 meters down in the Earth's mantle. They are made when carbon containing material is subjected to extreme temperatures and pressures. They are then ejected to the surface through volcanoes. Synthetic diamonds, on the other hand, are made by subjecting carbon containing material to high temperatures and pressures in a molten metal such as nickel or iron. The diamond crystallizes in the molten metal. These methods work because although graphite may be stabler at normal conditions, diamond is more stable at high temperature and pressure. These metals are not easy to interconvert because they both have strong bonds that must be first broken in order for the transition to be possible. A pure diamond is completely colorless while those with color tinges in them contain impurities. For instance, a diamond with a yellow tinge usually contains iron oxide as an impurity. These impurities get into the diamond while it is forming. The inherent color of a diamond is determined by the flashes of color it reflects when light hits it from different angles. A diamond reflects one fifth of the light that hits its surface. Glass is only able to reflect four percent of the light. The light that does enter the diamond is dispersed into hues which gives it the rainbow effect. Diamonds are not good conductors of electricity, but they are great conductors of heat. They feel cool to the touch because they conduct the heat away from your fingers. Experts can determine a fake from a real diamond by putting it on their tongue. Real diamonds will feel cool to the touch.

Terms:

Interconvert- to transition or interchange

Impurity- Inferior component or additive

Response:

I never knew this much about diamonds. I knew that diamonds were made when carbon was combined with heat and pressure, but I didn't know that they were ejected from volcanoes or how they were mad synthetically in a lab. The part about how impurities change the color of it was pretty interesting too. Most of the diamonds I have seen in my life have had some tinge of color in them. I just hope my girlfriend doesn't see this article. I know that she wants a pure diamond that isn't made in a lab. Who knows where I'll get the money for that? I do love the fact that pure diamonds give off that rainbow effect when you shine light on them. They definitely are beautiful. I just wish they weren't so expensive!

Diamonds!

While owning a diamond ring is nice, it is more interesting to understand the process by which diamonds are made. According to the text, diamonds are made through a process that occurs anywhere from 150 to 200 kilometers within the earth’s mantle. At this level, the carbon containing material that makes up a diamond is under both high temperature and pressure. Interestingly, diamonds are removed from the mantle through the eruption of volcanoes! Other forms of diamonds can be made, although they are synthetic, they appear to look similar. These synthetic diamonds are made similarly to real diamonds, by using carbon-containing material and subjecting it to high temperatures and pressures. Synthetic diamonds are made in molten metals like iron or nickel, which is what crystallizes the diamond. It is common that we can detect synthetic diamonds from real ones, because our skin reacts negatively to synthetic diamonds usually.
While consumers may prefer colored diamonds over the basic, colorless diamonds, it was interesting to learn that diamonds containing color are actually imperfections that were stuck inside of the crystal during its formation. However, this only applies to permanent coloring of diamonds. Diamonds that give off color when held up to light are not impure. Diamonds are also great heat conductors, and this is the reason for the intense coldness felt if touching a diamond. Many diamond specialists will actually place the diamonds on their tongue in order to know whether or not it is real! Lastly, diamonds are not good electricity conductors.
While I personally do not like diamonds, it was interesting to understand how they are made, and how easy it is to make synthetic copies. I do not want a diamond when I am married, I do not find them attractive. It seems as though our society has become obsessed with diamonds because they show a sense of status, and it has become a “fad” to have a diamond ring upon marriage. For this reason, I do not want a diamond! However, I respect whoever chooses to wear diamonds because I understand that receiving a diamond ring is many people’s dream, and it is a personal and sentimental experience for many!

Baird, Colin. Chemistry in Your Life. 2nd Ed, W.H. Freeman and Company, New York. 2006. (195-196)

The Plastic Recycling Debate

In our world, resources are limited and recycling is something that we ask of our society so that we can get the most efficient use of them. Plastic, but not all plastics, is known as a common recyclable material, but there has become a controversial issue. There are numerous reasons why many plastics are now collected from consumers and recycled, and a major reason is the overcrowding of landfills, especially throughout Europe. Even the plastics industry has been resisting the recycling of plastics in some places, because virgin plastic is a low-cost material made from low-cost raw materials, such as natural gas and crude oil. The result is that the amount of energy used to make plastics is very small compared to the amount used to produce aluminum or steel from its raw materials. “The cost of cleaning used plastic and converting it back into its monomers so it can again be polymerized is substantial, compared to the current cost of oil” (Baird 191). There are many people in the plastics industry who argue that the natural disposal method for plastics is to burn them, because the presence of plastics makes the other materials in garbage burn more cleanly and reduces the need for the addition of fossil fuel. This process will create heat energy, which can be utilized. Plastics make up more than a third of the energy content in garbage even though they account for less than 10% of the mass of garbage(Baird 190).

The counterargument by environmentalists is that recycled plastic would be the cheaper choice if environmental impacts were included in determining the costs of virgin materials. Additionally, the combustion of some plastics like PVC produces some toxic compounds and releases HCl, which attacks mucous membranes and damages the lungs when it is inhaled (Baird 190).

Although this debate is controversial, societies, including many developed countries, are embracing the recycling of plastics. “By the late 1990s, about half the urban communities in the US had curbside recycling programs that included plastics” (Baird 190). Consumers can identify the types of plastic collected in their area by the numbers stamped inside of the three-arrow triangle on each plastic object. In the mid-1990s, most of the plastics recycled in the US were HDPE and LDPE (Baird 190).

Unfamiliar Terms:
1) Virgin plastic: the material yet unused and just synthesized from fossil fuels
2) Combustion: rapid oxidation accompanied by heat and, usually, light
3) HDPE: a polyethylene thermoplastic made from petroleum
4) LDPE: a thermoplastic made from oil

Recycling is very important to me for the simple fact that there are limited resources in our world. I normally recycle anything that can be recycled, because I believe I am helping our resources last longer. In terms of plastic, I don’t use a water bottle and throw it in the recycling bin; I reuse water bottles all the time. I’m not positive if that’s unhealthy or not, but as long as I live a healthy lifestyle I’m not too worried about it unless something happens to me. Also, along with recycling, I believe that people should limit their use of resources. If you buy a case of water, then reuse the water bottles (assuming it’s not unhealthy) or even buy a reusable water bottle. If you are in the shower or washing your hands, then turn off the water if you are not using it. In the long run, I believe that we can make the world a better place by living this way.

Baird, Colin. Chemistry in Your Life. New York: W.H. Freeman and Company, 2006. 190-91.

Diamonds are a Girls Best Friend

Diamonds are sometimes called a girls best friend, but how are they made? It all started deep in the earth, around 150-200 kilometers. At this depth carbon-containing materials are subjected to high temperatures and pressures. The diamonds are then thrown out from the eruption of a volcano. Synthetic diamonds are made in molten metals within the volcano, metals that diamonds can be made in are iron or nickel. The diamonds are crystallized in these metals. Unlike the other form of the elemental carbon, graphite, diamond can be stable under higher temperatures and pressure. If a diamond is pure then it is colorless and if there is any color, it is due to the fact that the imperfections were trapped inside when the diamond was made. This should not be confused with any color that the diamond gives off when it is put up to light. Diamonds conduct heat and thus they feel cool to the touch. Some diamond experts can tell a real diamond from a fake by putting it on his/her tongue. If it is real it should be cold, kind of like a metal in your mouth.

Diamonds are great. I never new that they were made in a volcano. Although diamonds may be a girls best friend, I've always heard that they were not actually a rare diamond. That they were actually common, but most of the worlds supply is controlled by one person and that is why they are so expensive. Needless to say, I will probably still buy one at some point in my life. Not I know what to look for when I am buying a diamond. I will make sure to stay away from the fakes.


Baird, Colin. Chemistry in Your Life. 2nd Ed, W.H. Freeman and Company, New York. 2006. (195-196)

The Formation and Color of Diamonds

The article in Chapter 5 from section 5.13 is titled “The formation and Color of Diamonds”. The article explained how diamonds are formed 150-200 kilometers deep in Earth’s mantle from carbon-containing material that is subjected to high temperatures and pressures. The diamonds are taken from the Earth’s mantle along with rock, usually by erupting volcanoes. The article also explains that synthetic diamonds are produced by subjecting carbon-containing substances to very high pressures and temperatures in a molten metal such as nickel or iron. Although the diamond is not real it still crystallizes in the molten metal. This works efficiently because although graphite is stabler than diamond under moderate conditions, diamond is stable even at high temperatures and pressures.
Some new concepts that I did not know before reading this article is that real diamond is colorless. And that any permanent color that a diamond displays is due to impurities that were trapped in the crystal when it was forming. Another concept that I learned is that diamonds do not conduct electricity well, but they are good heat conductors. Finally I learned that experts can distinguish a real diamond from a fake one by placing it on their tongue. The real diamond feels cool like a metal.
I am very surprised as to how it is possible to make synthetic diamonds, and how easy it is for our own body to be able to tell the difference from a fake one. It is almost as if our bodies were designed to be able to distinguish some of the most treasured objects in the world.

Baird Colin, “The Formation and Color of Diamonds” Chemistry in Your Life. Second edition. W.H Freeman and Company, New York.

The Issue of Nuclear Waste

In the Baird text it is mention in Chapter 17.12 that while there are several proposals on how to solve the problem of nuclear waste, the issue currently is still unresolved in finding the best method of disposing the waste. One of the methods in disposing of nuclear waste is by vitrifying the waste or turning into glass where it can be buried underground. A second known method is is to cover it in Pu02, better known as plutonium dioxide and mix it with a uranium oxide to create a mixed oxide fuel that can be used in nuclear power plants. However, there is still no currently accepted ultimately decided method as to disposing of nuclear waste.

Some terms I found interesting in this portion of the text was the oxides used in the second method of waste disposal as I personally think that this method of waste disposal is probably the most practical and realistic due to it having a way of recycling energy. I also think it is very important that we find some other more effective way of solving the waste problem as the dumping of nuclear waste can be a severe health hazard to the communities that surround areas where waste is dumped. But in the meantime if we still have no currently accepted method then at the very least I think we should focus on the mixed oxide fuel method as we can also recycle energy in the process. But ultimately we must find a method sooner or later or we will certainly face the risks of health hazards in many surrounding areas where waste is dumped.

Baird,Colin, Chemistry in Your Life,2nd ed. ,pg. 638

The Recycling of Plastics: The Price of Cheap

The inventor of plastic products could not have foreseen the repercussions of his creation. Landfills across Europe are filling up, and our landfills here aren't looking too good either. We need to find a way to recycle the plastic we consume, since limiting the levels of consumption is out of the question.

The recycling of plastics seems logical, but it is still an issue that is causing great controversy. One of the biggest arguments against the recycling of this material is that virgin plastic is cheap, and remaking it into reusable material is expensive. The cost of this manufacturing would cause a level of accountability to those producing and consuming the plastic in the first place. But the producers and users of plastic don't want to be held accountable for what they're doing to destroy the planet if it means it will cost them something.

Some in the plastics industry argue that it would be better to just burn the plastic and use the heat energy provided. It sounds logical, since we already use energy from burning other forms of fossil fuel such as oil. This argument sounds viable as well, since the presence of plastic makes other garbage burn cleaner. One thing is wrong with this argument, however. The burning of some plastics, such as PVC, lets a number of toxic chemicals into the atmosphere. With current events pointing to the destruction caused by global warming, the last thing we need is to put more toxins into the air.

All we can hope for is that the majority of the developed countries, and undeveloped countries, will follow the benefits that recycling plastics bring.

'The Recycling of Plastics is a Controversial Issue.' Baird, Colin. Chemistry in Your Life. W.H. Freeman and Company. New York: 2006. pgs. 190-191.

Monday, April 6, 2009

Diamonds are a girls best friend...

This article discusses how diamonds are formed and the way in which they get their color. Diamonds come from almost 200 kilometers deep in the earth. Natural diamonds are made from carbon-containing material that experience high temperatures and pressure. Volcanoes help eject the diamonds from the Earth’s mantle. Humans make diamonds by increasing the heat and pressure exerted on carbon-containing materials in molten metal. This is where the diamond crystallizes. Diamonds are very stable at high temperatures and pressures, and that is how they are made. A pure diamond has no color even though we often see colored diamonds. The color on these diamonds comes from impurities that get trapped inside the diamond during formation. Iron oxide causes a yellow color for example. Diamonds can also reflect light very well. Other characteristics of diamonds include good heat conduction, poor electricity conduction, and cool to touch and to taste.

Diamond: a carbon containing material in which all the carbon atoms are bonded to four others in a specific, reoccurring pattern. The structure consists of six-membered rings with each ring also fusing to neighboring rings.

I have always wondered what is so special about diamonds and why they are so expensive. I can see that natural diamonds that come from the earth’s center must be really hard to come by and are worth a lot, but I still do not see why making synthetic diamonds is so fancy and expensive. I have heard a lot about the “blood diamonds” in Africa and I am still a little puzzled on why it is so violent in Africa when it comes to diamonds. I also always thought that colored diamonds were really rare and special, when in actuality a pure, perfect diamond does not have any color because it contains no other materials or impurities. Section 5.12 also helped give me a little bit of an insight on the structure and bonding of diamonds as well. Since Diamonds are bonded together so tightly they are the hardest substance on earth. Diamonds can scratch other materials but not themselves.

Colin Baird. “The formation and color of diamonds”, Chemistry In Your Life. 2nd ed. 2006. 195-196

Colin Baird. “Diamond: Its structure and bonding”, Chemistry In Your Life. 2nd ed. 2006. 194-195

Friday, March 27, 2009

Can a special diet really improve Autistic symptoms?

Scientists have witnessed a steadily growing correlation between certain gastrointestinal dysfunctions and Autism. One particular theory states that perhaps one cause of Autism includes the fact that some children’s digestive systems can’t digest certain elements (whether due to genes or not), and thus a child develops Autism. In addition to improperly working digestive tracks, recent studies have shown that gluten and casein from a child’s diet can help improve their behavior, speech, and therefore mental abilities. “Gluten and gluten-like proteins are found in wheat and other grains, including oats, rye, barley, bulgar, durum, kamut and spelt, and foods made from those grains. They are also found in food starches, semolina, couscous, malt, some vinegars, soy sauce, flavorings, artificial colors and hydrolyzed vegetable proteins. Casein is a protein found in milk and foods containing milk, such as cheese, butter, yogurt, ice cream, whey and even some brands of margarine. It also may be added to non-milk products such as soy cheese and hot dogs in the form of caseinate.” Gluten and casein form peptides in the body, which in turn can alter a person's behavior, perceptions, and responses to his/her environment. It is also thought that peptides trigger an unusual immune system response in certain people. Research in the U.S. and Europe has found peptides in the urine of a significant number of children with autism, signifying that proteins are not being digested properly. Although not every Autistic child has gastrointestinal problems, many of them do. The gluten-free casein-free diet has shown to be helpful in many cases whether the Autistic individual has digestive problems or not.

Peptides- substances that act like opiates in the body.

Paul Shattock and Dr. Paul Whiteley say: “The hypothesis may appear 'off the wall' in many respects, there are a number of pieces of evidence, which seem to support them. The ideas are compatible with virtually all the accepted biological data on autism and are therefore worthy of consideration. The dietary method must still be considered as experimental and no positive results can be promised or are claimed for every person." This shows very productive research in the search to getting closer the cause and treatment of Autism. My cousin Kyler has Autism, he has been on the GFCF diet for over a year now, and significant results have become of it. When gluten and casein are removed from his diet, Kyler has less tantrums, can interact with people more often than usual, and he sleeps better. At times, it is more difficult to get Kyler to like foods that are GFCF diet approved, and the diet can be a pricey one, but it is well worth the efforts. Although this diet may not prove hopeful for other cases of Autism, is still has proven more than beneficial for others.

http://www.autismweb.com/diet.htm

Thursday, March 26, 2009

China is our e-waste dumping ground

This article talks about the effects of electronic waste that goes from the United States to China. 80% of the electronic waste produced by Americans gets shipped to China. That is enough “to cover a football field and go a mile high”, this is only for one year! Why? One motivation would be that this way empty vessels that carry merchandise for Wal-Mart do not return empty to China. There is one city in particular that has a higher concentration on e-waste, Guiyu. This town several hours away form Hong Kong is lined up by many small “scavenger enterprises” that called themselves the “recyclers.” Guiyu is so greatly overwhelmed with e-waste that reeks with fumes and other toxics. Among some of the toxins are mercury and lead. These toxins gets into the citizens body and over a short or long time of exposure it turns into either lead or mercury poising or any other toxin. 82% of the kids six years or younger have some degree of lead poisoning. Lead poising, like other toxins, have many effects on the body. Kids, for example, develop problems in their reproductive systems. Other effects of poising include, respiratory problems and damage to the brain.
This should not be a surprise to anybody since the United States is one of the main contributors of electronic waste in the world because of the populations constant upgrading and purchasing of electronics. There are good civilians that “recycle,” however although they have done their part, recycling plants do not follow on their part of the deal. 90% of the claimed recycled electronics actually ends up on the grounds of electronics waste. This is also obvious due to the fact that we do not see any electronic dump sites around the states.

SKINNY SKINNY SKINNY- The American Dream

Years and years of research have found countless "cures" or "miracle" diets for obese individuals or those just interested in being thinner (especially with the media portraying anorexic bodies of models as beautiful). A new study found at UC Berkeley finds a particular gene significant in causing weight gain. As most people have heard of the atkin's diet which rules out the consumption of carbs. The Atkin's diet targets carbs as a problem nutrient causing people to become fatter. It stays in your body and carbs are transformed into fat. But a cure has been found. Studies on one lucky mouse have shown the lack of one gene actually keeps the mouse thin. It is the DNA-PK that "prevents weight gain from carbs". The gene is key in converting "excess glucose into fatty acids". It is not unhealthy either. The mouse without the gene is not only skinnier (thus more attractive, possibly happier?) but healthier, having a lower risk of heart disease. The mice were a womping 40% leaner without the DNA-PK in their genes. Crazy. At Hei Sook Sul's Nutritional Science and Toxicology Lab, they are not suggesting surgery to remove the DNA-PK from the system of obese patients but instead providing a new avenue for researching something to interfere with the conversion process, thus having the same affects. "Drug developers might look at how the DNA-PK gene calls out other actors to set in motion the conversion of excess calories to fat and find an agent that might disrupt the process."

This is very beneficial and a great find but are there ethical problems with this? Is this a invasion of nature? Then again, we are invaders of nature and possibly would not have to deal with obesity if we did not abuse it? If they cannot find a disrupter, would people be so desperate to be skinny or healthier that they would request and push for the surgery to remove the DNA-PK? Will the surgery be done underground (like abortion once was) if it is not publically/officially approved? What would the risks be?
It seems somewhat damaging to be able to eat as much as you want and because of the lack of a natural part of your body, people are still able to not gain weight. It sounds great but I feel there may be many side effects.

Healy, Melissa. "Lab Creates An All-It-Can-Eat Mouse". Los Angeles Times. March 21, 2009.

The Picturesque Dream of Grass Fed Cows No Longer Exists

John explains how today most farms are factory farm animals are fed corn, growth hormones, antibiotics, protein supplements, where the animal is slaughtered after 14-16 months instead of after 4-5 years like how it was done. The reason why the cows are given anti-biotics, is so they do not die from eating all of the corn, what they naturally are not supposed to be eating. The factory farm owners want more money, so they feed the cows much corn over a short period of time, to quickly fatten them up. Since these cows are fed much grain, a higher occurrence of E. coli 0157:H7 bacteria exists, and this E-coli has the ability to possibly kill humans, because the acidity of the cows is similar to humans. Also, these grain fed cows have more fat, saturated fat, and 15-50 percent less omega 3’s than grass fed cows. To look on the environmental side, grain-fed animals produce much waste that can pollute rivers and the atmosphere. According to Cornell ecologist David Pimentel, to grow all of the corn to feed the cows, many fertilizers are necessary, meaning a great deal of oil is needed. Now from a humanitarian view, the animals do not need to live in close confinement, where cows are standing knee deep in their own excretement or are forced to stand in tight pens. Although surprising, grass fed is not the best option either, because cows that are raised on a pasture create more methane than grain fed, and the U.S. has too high of a demand for meat for grass fed farming to be economically feasible. Yet, it does need to be understood that although grass fed meat is more expensive, grass fed meat does not mean that it is organic, and same for the other way around. Also, grazing can take up much space, such as how in the Mid-west, where any land that can be grazed by cattle is, and wildlife is being threatened. The best option would probably just be for someone to reduce their consumption of meat.

No difficult concepts.

This article was interesting in that it discussed how cows that are corn fed are not as healthy as everyone thinks, and that actually grass fed cows are. Although the author John is not too biased, in that he also lists the negative side to grass-fed cows, not just that all cows should be grass-fed. He actually at the end of the article explains how you are better off just eating less meat, and that you should only buy grass fed beef if you are to buy meat. I already knew about how factory cows have less omega 3 acids, but I am curious as to currently (this article is 8 years old) how much less omega 3 acids factory farm cows have. I am asking this because the only reason why cows eat omega 3 acids is, after fish die in rivers they end up on the shore where the grass is, where they then decompose into the soil. But what is the average population of fish in rivers now? I suppose one of the reasons why people like to eat much meat, is that grain fed cows have more fat than grass fed, and humans are naturally attracted to fatty foods, so maybe that is the reason why it is hard for people to eat less meat.

Overall, this article could be a real eye opener to beef eaters who think that the benefit of the protein they consume outweighs the negative effects of the fat. It also discusses the humanitarian perspective, but mainly focuses on the environmental and health perspective. Even for those who do not care about the environment, maybe them seeing how meat is really not as healthy for them to eat as they think will cause them to eat less meat. I am doing my part by not eating any meat, but unfortunately one person who does not eat meat will not do a whole lot to combat this issue, so it probably has to be the controllers of the media who need to unveil this issue.

Robbins, John. “What About Grass Fed Beef?” The Food Revolution : How Your Diet Can Help Save Your Life and the World. Conari Press. Berkeley, CA. January, 2001.
Or here is website: “http://www.foodrevolution.org/grassfedbeef.htm”

Stress, Cortisol, and Weight Gain: Is there a connection?

Stress has a multitude of physiological effects, including increased weight gain. Stress is the physiological representation of the body failing to respond to real or imagined threats. Such effects can include clenched jaw, tight neck and back, mood changes, and also biochemical changes. These biochemical changes can be positive or negative, and are controlled by the hypothalamic-pituitary-adrenal axis (HPA). When triggered, the HPA axis releases various hormones, including the “stress hormone” cortisol.

The release of cortisol causes blood sugar and blood pressure to increase. Current theories suggest that high levels of cortisol are a factor in weight gain, particularly in belly-fat. The exact relationship between stress and weight gain is still being researched. What is known currently is that lack of sleep increases cortisol levels, which causes an increase in appetite. Other studies have concluded that cortisol levels serve as a means of predicting weight gain. Another study conducted in December of 2008 at the University of Oregon found a connection between cortisol levels and weight gain at a genetic level. One other correlation that has been found is that when people are stressed, they are less likely to follow a proper, normal diet, possibly adding to the connection between cortisol and weight gain.

Cortisol has amazing effects throughout the body. It is important to note that such things as a lack of sleep can seriously alter your eating habits. It is certainly surprising to learn this type of correlation has been made scientifically, because there are so many more lay-men explanations for weight gain (psychological problems, not eating healthily, not exercising enough, etc). Perhaps this knowledge can potentially help fight obesity in the future?

Sygo, Jennifer. "Which came first, the belly or the stress?" National Post 26 Jan. 2009. 15 Mar. 2009 .

Going, going...gone?

Going, going…gone?
Due to pollution, disease and global warming coral reefs are dying off at astounding rates. Scientists are trying to create new and effective ways of preserving these reefs in order to protect biodiversity, human economies and the coral reefs themselves. The article claims that if the rise of carbon dioxide does not diminish the oceans will be “chemically inhospitable” for reefs. Ocean acidification is a major contributor to coral bleaching, which is a major threat in the killing of coral worldwide. Once the coral becomes “stressed” by warming waters and acidification, they will expel the algae that serve as its food and gives it its color. Once the coral becomes pale or white it will soon die off. As a result the ecosystem that relies on it will suffer. On a brighter note, there have been studies that prove that coral bleaching can be reversed even in its most extreme stages. If we reduce other stressors such as over fishing and also introduce new types of algae that can survive the rising temperature may help inoculate the coral.

Coral Bleaching- is the loss of color of corals, due to stress-induced expulsion of symbiotic unicellular algae or due to the loss of pigmentation within the algae.

Although the extent to which this article describes the negativity of coral bleaching is rather extreme, it just gives a very "worst care scenario" type of depiction. The process by which coral is bleached is very complex and is very reversable if caught in time. Many stressors around them dissallow any recovery from the bleaching process. Thus, as the article mentions, a possible way to reduce the extent to which corals are bleaching is by removing such stresses.

Platt, John. "CORAL REEFS: VITAL TO THE OCEANS, VITAL TO HUMANS." Scientific American 11 Feb 2009 26 Mar 2009 ..

The Malaria Parasite Is More Powerful Than You Think

In his New York Times article entitled Manipulative Malaria Parasite Makes You More Attractive (To Mosquitos), Carl Zimmer discusses a recent study which has found that the malaria parasite, plasmodium, is able to manipulate mosquitoes to make them more attracted to humans. The malaria parasite has been on this planet longer than humans and scientists have always been intrigued by its incredible ability to survive. This new discovery gives them a little bit more understanding of how this tiny, single-celled parasite has managed to evade their attempts to eradicate it. Scientists first started making discoveries about the ability of some parasites to manipulate their hosts in the 1970s. They found that this ability to manipulate is common for parasites which require more than one host during their life-cycle. The first discoveries about plasmodium’s abilities to manipulate their hosts were discovered in mosquitoes. When mosquitoes drink the malaria-infected blood of a human, the malaria parasites immediately begin to manipulate their new host by making it more cautious about finding another human or animal to feed on. The parasites manipulate the mosquito in this way to make the mosquitoes survival more likely. The parasites want the mosquito to survive because they need a period of time to develop within this host before they can be transferred into another one for further development. When the parasite is prepared to move on to a new host, it changes its manipulation of the mosquito. The parasite causes their host mosquito to become twice as likely to bite more than one person in a night as well as causing it to spend more time drinking the blood of its victim. The most recent malaria studies show that these parasites are also able to manipulate humans as a mode of survival. After the plasmodium enters the human body, it spends time developing in the liver. The parasite then multiplies and invades blood cells. The parasites feed off these blood cells, continuing to multiply, until the blood cells burst. This process is then repeated. These parasites can then be picked up by mosquitoes, enabling the survival of the species. Scientists have discovered that this survival has been facilitated by the parasite’s manipulations of humans. Research indicates that mosquitoes are more attracted to humans who are infected with malaria than humans who are not. Thus, the spread of the disease is facilitated. Scientists are still unsure of how the parasites make infected humans more attractive to mosquitoes. However, they feel that once this discovery is made, huge advances could be made in the fight against malaria.
Unknown Terms
Gametocytes: a cell capable of dividing to produce gametes (Biology Online)

The more I read about the malaria parasite, the more impressed I become at how advanced it is. It is incredible that something as tiny as a parasite can have the ability to control the behavior of a mosquito. It is no wonder that it has been such an uphill battle to control the spread of malaria. It gives me hope that scientists are making so many discoveries about this parasite that kills over one million people per year. Once researchers discover what plasmodium does to attract mosquitoes to humans, they could formulate a way to interfere with that manipulation and hinder the spread of the disease. However, malaria has proven to be a master of adaptation and even this might not bring about an end to the disease.

"Gametocytes." Biology Online. 3 Oct. 2005. 26 Mar. 2009.

Zimmer, Carl. "Manipulative Malaria Parasite Makes You More Attractive (To Mosquitoes)." New York Times 9 Aug. 2005. 26 Mar. 2009 .

Can vitamin supplements fight cancer?

Contrary to popular belief, vitamin supplements such as Vitamin C, Vitamin E, and selenium cannot fight cancer or disease. Recent studies have repudiated the long-held belief that such supplements could fight heart disease, cancer, stroke, and other illnesses, by showing that they have had no effect on preventing ailments, and in some cases they can be harmful. In December of last year, long-term trials involving 50,000 participants irrefutably proved that vitamin supplements have no effect on reducing the risk of lung, colorectal, bladder, prostate, or pancreatic cancer. Furthermore, more recent studies have shown that over-the-counter minerals and vitamins also cannot help fight strokes, cardiovascular disease, and other cancers. Instead, physicians recommend getting a healthy daily diet of fruits and vegetables, instead of relying on “wonder pill” that can even be harmful to one’s health. However, scientists still remain puzzled at how essential vitamins for the human body, such as selenium and Vitamin E, are not effective as supplements in randomized controlled trials.

Unfamiliar terms:
Selenium: is a trace mineral that is essential to good health but required only in small amounts .Selenium is incorporated into proteins to make selenoproteins, which are important antioxidant enzymes. The antioxidant properties of selenoproteins help prevent cellular damage from free radicals

Reaction:
I thought this article was helpful in correcting the mistaken belief that vitamin pills can make up for eating fruits and vegetables, and if there was a pill for every vitamin or mineral that we need, we could take each one and be perfectly healthy, as well as be at a lesser risk of developing cancer or other diseases. For me, this was important to realize, not only because people spend money on buying pills to be “healthy,” but also because taking these pills can have harmful effects, which many people are unaware of. It was also interesting to me that scientists still are not sure why vitamin supplements, which apparently contain nutrients crucial for human life, are so ineffective when taken as pills and are not found in our diets.

References:
Kaplan, Karen. “Vitamin supplements don’t fight cancer, studies show.” LA Times. 21 Dec. 2008. 26 Mar. 2009. http://articles.latimes.com/2008/dec/21/science/sci-vitamins21
“Dietary Supplements Fact Sheet: Selenium” Office of Dietary Supplements. 26 Mar. 2009.
http://ods.od.nih.gov/factsheets/selenium.asp

Obescity and Genetics?

In a study lead by the Genetic Investigation of Anthropomorphic Traits (G.I.A.N.T.) there has been six new genetic variants that are associated with body mass index or BMI for short. In a nutshell the body mass index is a method for measuring the comparison between height and weight. According to the study, the effects of each of these genetic variants were modest and much like many common problems with studying genetics only a small fraction of the regions of the human genome have been mapped at least in these regions that this study believes helps contribute to obesity. According to the paper sub,itted by the study team, thier is an estimation that one percent of the people who in thier bodies have these particular varients have an average of being ten pounds heavier than people who have one percent with the fewest varients as well as being about four pounds heavier than the average person. These six newly discovered genes have been shown by this study to have a relation to BMI and four of these varients have relations to adult and childhood obescity. Also in additon to this study two more genes (FTO), (MC4R) which were suspected last year to have association with BMI have been confirmed to be associated with the BMI.

I think this study is very important due to health risks of obescity. With the end of the HGP the field of genetics has been opened up to all sorts of possibilities and with studies such as these health problems such as obescity may have a chance to become more regulated and ways to combat it at a genetic level may emerge from this. Its very intresting to see the new applications genetics research has found and this shows that genetics research is far from being over and all sorts of new studies such as this one show a bright future for genetics and solving some of humanities problems concerning health and the body.


National Human Genome Research Website
http://genome.gov/27529231

Wednesday, March 25, 2009

The Acids in Our Food

The Acids in Our Food 

Many foods have the ability to send the message “sour” to our brain when consumed. This is because of low pH levels that result from H+ ions reacting temporarily with molecules on the side of the tongue. This causes a change in shape, which sends the “sour” message to the brain. This entire process is due to the presence of weak acids. All citrus fruits contain citric acid and the overall flavor in these fruits is due in part to ascorbic acid. Ascorbic acid is also known as vitamin C. The pH levels of these fruits vary usually from 2 to 4, which correspond to H+ concentrations of 0.01 and 0.0001 moles per liter. This means that the level of hydrogen ions in things such as lemon and lime juice is 100 times greater than things like oranges and tomatoes. Wine also contains weak acid, usually at about 0.7%. Even milk contains an acid, known as lactic acid. Vinegar, which is produced by the fermentation of sugars when they are oxidized beyond the alcohol state, has a pH of about 3. It is a dilute solution in water of acetic acid. This process of oxidization is why some drinks become too sour to drink when exposed to air for a long period of time.

Unfamiliar terms:

• pH: a shorthand way of indicating H+ concentrations; the power of 10, without the negative sign, for the molarity of an H+-containing solution (G-8)  

As a child I liked the taste of anything sour and have even tried to eat lemons and limes all by themselves. It always seemed funny to me when others found this strange or did not like sour things as much as I did. While I do not know the reasons behind mine and other’s preferences, I found it interesting to learn about this odd taste. I did not know before about pH levels and that in the weak acids I consume these levels are usually low. While I had heard of citric acid before, I had not known about ascorbic acid, which is vitamin C. I also found it interesting that the level of hydrogen ions in lemon and lime juice is so much higher than those of oranges and tomatoes. After reading this section I also learned that the cola drinks I drink every day have phosphoric acid in them. Learning about these many different types of acids made me realize that I consume much higher levels of acid-containing foods and beverages than I previously knew. I love citrus fruits and drinks, and also drink soda on a regular basis. I will also have vinegar in my food as well as milk, which has lactic acid.

In the future, I wonder if there will be new discoveries as to how all of these different types of acids can be utilized. On the side note of this section it explains that washing your hair with an acidic substance such as vinegar makes it shiny. This is because the acidic substance shrinks the hair cuticles and hardens them, making them lie flat. I did not know about this trick, and would possibly try it if vinegar had a better smell. This section also states that vinegar can help dissolve soap scum, which increases the luster of hair. This means that vinegar can also be used to clean other things. Possibly in the future, chemists will be able to use the various acids found in our food and beverages and extract them for further use along the same lines as vinegar.

Baird, Colin. Chemistry in Your Life. W.H. Freeman & Company, New York. 2006. 429-430. 

Drug Addiction=Drug Trafficking

Recently the Obama administration announced that it would rapidly send hundreds of federal agents to the Mexican border with special technology in an attempt to ease the flow of drug cartels entering the United States from Mexico. The goal is to prevent the violence that is occurring in Mexico from entering the United States. In the past year and half drug problems and violence have reached an alarming and very dangerous level in Mexico and the President of Mexico Felipe Calderon has been seeking help from the United States. The United States says that it will spend hundreds of millions of dollars this year to not only protect the borders, but to decrease the demand for illegal drugs in the United States and to lower the number of weapons and amount of money sent into Mexico for drugs. According to many people in Washington the plan looks promising, impressive and is expected to have a huge impact on the problems occurring in Mexico and around the borders.

Unfamiliar Terms
Felipe Calderon: “the current President of Mexico. He assumed office on December 1, 2006, and was elected for one six-year term that will end in 2012 without the possibility of re-election.”

Although the article itself does not directly relate to chemistry, there are indirect relations. People in the United States are becoming very addicted to drugs and will do anything to get drugs. When someone begins using drugs and continues to use the drug over a period of time, their brain and body develops a tolerance to the drug and need more of the drug to produce the effects. This keeps increasing and people need more and more drugs. Addicts become so involved in their drugs that they can’t function without them and they find themselves resorting to violence and illegal activities in order to get the drugs. This is a major social problem related to drug use. Drug violence does not only affect the user, but has serious consequences on family members, friends, and even innocent bystanders. With the Mexican border less than 2 hours away from my home this problem is very alarming to me. I used to be able to go to Mexico for nice beach vacations or cruises, but now it is much too dangerous. There is constant violence associated with drugs not only in Mexico, but beginning to leak into the United States as well. Drug dealers in Mexico know that there are many Americans that are so addicted to drugs that they will do anything to get the drugs. Since the Mexican economy is a struggling one, the Mexican dealers will, lie, steal, and murder in order to make the money off of the drugs. This is a serious problem and personally the first aspect of Obama’s administration that I am pleased about.

Josh Meyer. “Mexico Under Siege; U.S. unveils anti-cartel border plan; Hundreds of agents and analysts are being sent to target drug trafficking and to curb the spread of violence” Los Angeles Times. Los Angeles, Ca. March 25, 2009 pg. A1

“Felipe Calderon” Wikipedia. March 25, 2009. http://en.wikipedia.org/wiki/Felipe_calderon

Monday, March 16, 2009

Protein is vital to the body and requires about one gram per day per kilogram of your body weight. “Your body synthesizes the protein molecules it needs by polymerizing amino acids from a pool of them that originally was part of the protein in your food” (Baird). Your body decomposes dietary proteins into amino acids, using digestive enzymes, which is the essential protein required by the body. Sources of protein in the human diet vary from culture to culture. Fish is a common source of protein that is easily digestible since it contains little connective tissue that is difficult for the body to break down. Meat is also a common source of protein, but sometimes it needs to be “tenderized” before it becomes pleasurable to consume. There are only 10 out of the 20 amino acids required to make proteins that are essential to have in your diet, which are called the essential amino acids. The other 10 are nonessential, meaning that they are not essential in your diet.

Unfamiliar Terms:
1) Synthesize: to combine into a single or unified entity
2) Polymerize: The bonding of two or more monomers to form a polymer
3) Tenderize: breaking down proteins into smaller, more tender, and more flavorful components using natural materials that contain enzymes
4) Essential amino acid: an amino acid that is required for human life and well-being but cannot be synthesized by the body from other compounds

This information is very useful to me and anyone else who is interested in lifting weights and building their bodies. Protein is essential in building muscle and the overall health of the body, but a lot of people these days don’t eat the right foods that contain it. Powered proteins and protein pills are sold in stores, but there’s no need to buy them if you eat correctly. Many athletes choose to buy protein supplements, but good eating habits will provide you with enough protein. Also, too many people rely on the protein supplements, because they think that as long as they are taking them then they are getting the protein they need, which is not true. If you are relying on protein supplements, then you are just wasting your money. I believe it is very important to understand this, because too many people are influenced by the media and feel that they have to buy a lot of supplements to maintain their health.

Baird, Colin. Chemistry in Your Life. 2nd ed. New York: W.H. Freeman and Company, 2006. 349-50.

Chemistry In Our Lives

Chemistry is a part of our daily lives even though we don’t always think about it or find it relevant to our own individual lives. Sports and fitness have become a very important and popular part of our culture, which have both been affected by chemistry. The value and importance of chemistry has led to an increase in student interest to promote it to others. Everyday athletes interact with synthetic and natural chemicals that play a vital role in their performance. The advancement and progression of science has led to a dramatic increase in its use in sports, which in turn has made sports more complex and questionable as well. Race cars are using lighter materials to drive faster; basketball players are using lighter shoes to move quicker; fishermen are using more complex materials to catch more fish. These advanced materials are known as “high-performance” equipment. It is true that supplements and technology do not make the athlete, but it is not to say that athletes are without the benefits of chemistry. Chemistry plays an extremely important role in athletic performance, and sports would not be what they are today without its use.

The impact of chemistry is evident in a wide range of sports. Golf clubs, once composed of aluminum or steel shafts, are now made of composite fibers or polymers, such as Kevlar, to launch golf balls at higher velocities while maintaining accuracy (Giffin 814). “On the course itself, polymers are used to encapsulate fertilizers that slowly release their nutrients to ensure immaculate fairways and a smooth roll of the golf ball on lush greens” (Giffin 814). In football, modern shoulder pads are made of polyethylene and and polycarbonates, and much of the clothing is made of polyesters (Giffin 814). In tennis, rackets are composed of carbon composite materials that can have a larger head and a larger sweet spot, resulting in increased power and control (Giffin 814). In track, modern pole-vaulting poles are composite materials of carbon and fiberglass, which provide greater flexibility and strength to propel the pole-vaulters to higher marks. Many athletes in these sports use polyester clothing, which provides low air resistance and moves perspiration away from the body. Elasticity, strength, and lightweight are all characteristics of this type of clothing, which is valuable to the athletes. This “high-performance” sporting equipment not only benefits athletes because of their chemical composition but also how they are constructed and designed. Even though sports have become as complex as they are right now, scientific research is continually progressing and scientists are searching for new ways to develop materials.

In relation to the chemistry involved in athletic materials, the chemical compounds in sports medicine and supplements are also used to help the athlete. Steroids and Creatine are two of the most popular performance-enhancing drugs that athletes use for athletic enhancement. Not only do athletes use drugs for muscle enhancement, there are other widely accepted supplements such as sports drinks like Gatorade. “Sports drinks are a lucrative market with more than $2.4 billion in sales in 1999” (Giffin 815). They provide energy sources such as fructose and replace lost electrolytes such as sodium and potassium. In conclusion, it is important to understand how chemistry is involved in our daily lives.

Unfamiliar Terms:
1) High-performance: materials that are stronger, more resilient, and lighter weight than traditional materials such as wood and steel
2) Polymers: high-molecular-weight organic compounds comprising many smaller repeating molecular units
3) Polyethylene: a plastic polymer of ethylene used chiefly for containers, electrical insulation, and packaging
4) Polycarbonate: a synthetic thermoplastic resin, a linear polymer of carbonic acid, used for molded products, films, and nonbreakable windows
5) Polyester: any of numerous synthetic polymers produced chiefly by reaction of dibasic acids with dihydric alcohols and used primarily as light, strong, weather-resistant resins in boat hulls, textile fibers, adhesives, and molded parts
6) Creatine: an amino acid, C4H9N3O2, that is a constituent of the muscles of vertebrates and is phosphorylated to store energy used for muscular contraction
7) Electrolytes: any of certain inorganic compounds, mainly sodium, potassium, magnesium, calcium, chloride, and bicarbonate, that dissociate in biological fluids into ions capable of conducting electrical currents and constituting a major force in controlling fluid balance within the body



I think this article is very interesting and love the point it is making to athletes and students. It is trying to get us to realize how much chemistry is involved in our daily lives and how important it is to realize it. Chemistry has very valuable information to offer and the more educated we are about drugs, supplements, and scientific materials the better decisions we can make for ourselves and pass on that knowledge to others. Also, knowledge about drugs and supplements will have a great effect on our psychological and physiological health so it pays to be well informed. Many people are too easily persuaded by advertisements and the media that they buy and consume whatever they believe could work for them, which results in the loss of a lot of money and a loss of health sometimes. And understanding how chemistry works helps so much in creating products for athletes that keep them safe and comfortable. If football players today wore leather helmets like they used to, then there would probably many deaths in the sport, which is why they wear such protective pads. This knowledge will really pay off in the long run for everyone.

Giffin, Guinevere A., Steven R. Boone, and Scott E. Mckay. "Modern Sport and
Chemistry: What a Chemically Aware Sports Fanatic Should Know." Chemistry for
Everyone 79. 7: 813-19.

Disease and Parasites: YUCK!

Monica Ek
Disease and Parasites: Yuck!
Although, recently new findings have linked harmful affects from byproducts from chlorine used as a disinfectant, the consequences of not using the chemical are worse. Disinfecting the water is one of the best uses of chemistry in our world in benefiting humans. Public health is better, disease has decreased and the well-being of people can be better managed. The fear of the byproducts has had a bad affect on its usage. The reality is though, that disinfectant has saved millions of lives. “Typhoid and Cholera were widespread in Europe and North America a century ago, but they have been almost completely eradicated in the developed world thanks largely to chlorination and the other methods for disinfecting drinking water.” This isn’t the same case for developing countries that do not use disinfectant in their water system. Water is living and nesting place for lots of bacteria, parasites and diseases especially if it is not treated. When the water sits their underground, anything can leak into it. The use of wells is also a nesting ground for illness. Many villages in under developed countries are unaware of the risks they are taking all the time with the water they drink. Most countries don’t use disinfectants because lack of awareness, lack of funds or sometimes the fear of the byproducts. “20 million people die each year from water-borne diseases” where water is not treated.
It still is also a concern in developed countries especially with new illness such as the pathogen Cryptosporidium in Milwaukee, Oxford, England and North Battleford, Saskatchewan. This was a problem because it was resistant to the usual disinfectants such as chlorination and chlorine dioxide. It is also is very small so easily passes through filters. But research was done to find that other disinfectants worked including ozonation and ultraviolet treatment so it was eradicated. This extra money for research would be helpful but unavailable for those villages in developing countries. Cleanliness and overall sanitation would help a lot as well especially in the placement of human and animal feces. Water disinfectants would be so helpful in preventing illnesses worldwide.
Also, the equipment for water purification has to be carefully monitored as it can fail or be ineffective if it is monitored improperly. The importance of disinfectants is shown when, for example, in Walkerton, Ontario the equipment failed and the population was quickly affected with sickness as well as a few deaths by a deadly bacteria. Disinfectants are needed and important,.

How much research has been done on disinfectants? Can we eradicated more than we know ? Are we only paying attention on the diseases and waterborne illnesses within developed nations as there is funding? What is the potential for disinfectants? Can we research more to come up with something other than chlorine with less harmful byproducts, possibly a green disinfectant? How can we spread awareness to developing countries? How can we clean wells and water systems without being nationalistic?
What are we currently doing? If we can create the equipment in developing countries, how can we make sure is properly maintained to be affective?

Baird, Colin. “Chemistry in Your Life”. W.H. Freeman and Company. New York. 2006.

Thursday, March 12, 2009

Batteries Can Power Electric Cars

Our society has constantly been trying to reduce the air pollution in our atmosphere and one way is the use of electric cars. Many of the electric cars that have already been marketed use similar lead-acid batteries that gasoline-powered vehicles use to operate the starter motor, and many batteries need to be connected together to produce the power that is needed (Baird). Future electric cars might use nickel-cadmium, nickel-metal hydride, and lithium-based batteries (Baird).

Although battery-powered vehicles might reduce pollution, there are many practical difficulties that discourage their use: high cost, the short driving range before the batteries need recharging, the length of the battery recharge period, and the heaviness of the batteries (Baird). Secondly, electric cars are not entirely free of pollution. “Some pollution is emitted into the environment if the electricity required to charge the batteries is generated from fossil fuel combustion” (Baird). Also, lead pollution from the manufacture, handling, disposal, and recycling of lead-acid batteries would cause a rise in lead emissions into the environment according some economists and engineers.

Now several automobile manufacturers offer “hybrid-electric” cars with electric motors that run from power stored in batteries. For example, the Toyota Prius has a small gasoline engine that charges the battery and supplements its power at high road speeds (Baird). Also, “the energy lost by a conventional gasoline engine during idling is eliminated since the electric motor is switched off at these times” (Baird). The battery is recharged without the use of fuel during braking by using the energy of the motion of the vehicle that is usually lost as heat, which occurs in all hybrid-electric vehicles (Baird). Because of these features, the efficiency of the electric motor, and its lack of pollutant emissions, these cars are much more energy-efficient and cleaner than normal gasoline-powered cars.

Unfamiliar Terms:
1) Combustion: rapid oxidation accompanied by heat and, usually, light.
2) Nickel-cadmium: The principal advantages of NiCd over other rechargeable types is lower weight for a given quantity of stored energy, good charging efficiency, small variation in terminal voltage during discharge, low internal resistance, and non-critical charging conditions. They can be used in place of regular batteries in most applications.
3) Nickel-metal hydride: A nickel-metal hydride battery, abbreviated NiMH, is a type of rechargeable battery similar to a nickel-cadmium (NiCd) battery but using a hydrogen-absorbing alloy for the negative electrode instead of cadmium. As in NiCd batteries, the positive electrode is nickel oxyhydroxide (NiOOH). A NiMH battery can have two to three times the capacity of an equivalent size NiCd. However, compared to the lithium-ion battery, the volumetric energy density is lower and self-discharge is higher.
4) Lithium: Lithium hydride is used as a source of hydrogen; lithium hydroxide is used as an additive in storage batteries and to absorb carbon dioxide.

This excerpt from from Chemistry in Your Life is exactly why chemistry is so important to understand. Understanding chemistry can help us improve the future so that we can have a healthy world to live in. It is so amazing to me how we have such complex techonology that we can create different types of car batteries to decrease pollution. I believe it is so important to recognize that pollution is a huge problem in our world today, because it jeopardizes our health. Businesses are so concerned with making money that they don't care about the ethics involved. Pollution is a major concern in our society today, but I do believe we are on the right track to realizing we need to take care of the world we live in.



Baird, Colin. Chemistry in Your Life. New York: W.H. Freeman and Company, 2006. 461-62.

Is This the United States of America, or Is This the Contamination Nation?

In the 1960s Lake Erie got extremely polluted with phosphates, leaving many fish to die and rot, meaning this once admired beach was turned into a wasteland. Phosphate ions come from point and non-point sources. Point sources are particular locations like towns, cities, and factories that each, produce much pollutant waste. Non-point sources are places such as farms, home septic tanks, housing developments, and golf courses that each, produce less waste. Although, non-point sources actually can produce more waste than point sources, because there are many non-point locations that can combine to create much waste, such as how many farms do. Too much phosphate in freshwater lakes and rivers can cause environmental issues. The extra phosphate in the water, which is not supposed to be there, helps much more algae grow to the point of an algae bloom, meaning a lot of oxygen is taken in by the algae as it decomposes, and then much fish die. To help clean the Great Lakes of these nasty phosphates, 8 billion dollars has been spent in creating sewage treatment plants that remove phosphate before it goes into the lakes. Ontario and other states around the Great Lakes were restricted in the amount of phosphate that could be put in detergents, which has led to a decrease in two thirds of the amount of the total phosphate going into the lakes. Now Lake Erie has fish life back in it, meaning commercial fisheries are gaining business, and the public is visiting it once again.

There were no difficult terms in this article.

I knew a little bit about this topic area since I have taken Environmental Studies classes, but I actually do not remember learning about the poor shape Lake Erie used to be in. The pictures in the book were so surprising! Someone is showing their hand covered in green much from the water before, because of the algae blooms. It looks as if they put their hand in a can of green paint! This article explains why sometimes I see “no phosphates” written on the back of laundry detergents. This article really makes me open my eyes to the amount of sources where pollutants come from, and the fact that they cannot all be controlled. It is interesting although, how these non-point sources can be indirectly controlled to reduce the amount of phosphates by not putting phosphates in laundry detergents, and point sources can be built to remove phosphates before they get into these freshwater lakes. Although, this article really makes you wonder if, how do we know that there are not many other pollutants that are put into these rivers? Much phosphate was put into these lakes, but we only figured this out because of all the algae blooms, so what about other pollutants that are put into the lakes that do not have effects like phosphate that can be seen with the naked eye. How do we know that these lakes are safe to swim in, even thought they are clear?

This article reveals that we as people can make big differences in our environment with whatever chemicals we use. Even though Clorox Bleach may seem convincing on T.V., because the people in the T.V. commercials list all of the diseases/germs that Clorox can protect you from, but is it really worth it to buy this Clorox that will leach nasty chemicals into our groundwater? Also, even if an item says that it does not have phosphate in it, it does not automatically mean that it is safe to use. Although, just because I know this, does not mean that everyone else will, so how are consumers going to know? Well, it would have to mean that more environmentally friendly products would need to be advertised, but I highly doubt that will happen anytime soon. This is really what would help stop pollutants from going into our groundwater and into freshwater areas. If advertisements were put on T.V., telling people to buy organic groceries, because non-organic ones have so many chemicals in them, then at least that would be the start of the change of the agricultural industry.

Baird, Colin. “Phosphates From Point and Non-point Sources.” Chemistry in Your Life. Second Edition. W. H. Freeman and Company. New York. 2006. Pg. 509.

Natural or Enhanced?

Natural or Enhanced?
The list of ingredients on the side of any food package, not only tell you the main ingredients, but also a list of chemical names that may not seem as significant. In fact they are a list of food additives which are used in order to enhance the taste, texture and color of the food you are eating. Some of these names also include antioxidants, sweeteners, emulsifiers and preservatives. Colors and bleaching agents are added to food in order to give an appetizing and expected color to the food. There are seven certified food coloring in the United States, and others that have been found to be carcinogenic have been banned. Thickening agents and texture modifiers include carrageenan, a carbohydrate that is taken from Irish moss and modified natural substances. Flavor enhancers exaggerate the taste of a food, such as meat so that they do not have to use as much of the real food, of products that may be deemed inferior in a specific dish or food product. Some flavor enhancers such as MSG or monosodium glutamate are used in foods like Chinese food and can give some people headaches.
Antioxidant- A substance that prevents the occurrence of oxidative damage from free radicals.
Emulsifying agent- A substance that is soluble in two substances which are insoluble in each other and that enables them to form an emulsion.

Additives seem to be a way of making food seem better that it occurs naturally. This may be a good or bad thing depending on whose perspective you are looking at. They are good in making food more appetizing, which is beneficial especially when feeing young children. However I do not think that they can be all that healthy for you, but I could be wrong. It also seems that flavor enhancers are a way of cutting the cost in producing food, since you are using less of the “real thing” and more of the “fake” stuff. This is a good way of cutting back economically, but seems like a very cheap way to make food. It does seem better to use food enhancers instead of “inferior-quality” ingredients, but it is still making the food not as good of quality as it would be if you used the “real thing”. So is the food we are eating the real, natural thing or is it enhanced? I suppose by reading the ingredient label we could figure it out!

Baird, C., The Ages of History, Chemistry in Your Life 2nd Ed.,W.H. Freeman and Company, 2006. P. 385-386.

Enhancing Our Food

Enhancing Our Food
On the back of most packaged food contains the ingredients in descending order based on amounts. The main component listed usually is followed by a list of chemical names. These chemicals are additives similar to antioxidants, preservatives, sweeteners and emulsifiers. Three other additives that are commonly added to food are colors and bleaching agents, thickening agents and texture modifiers as well as flavor enhancers. Colors and bleaching agents give food whatever color consumers expect and find appetizing. About 30 different substances, either synthetic or naturally occurring can be used for food coloring. In the United States, only seven of these have been certified for use. Thickening agents and texture modifiers included natural carbohydrates extracted from Irish moss, different types of gum and other modified natural substances or cellulose derivatives. Finally, flavor enhancers such as MSG are used in Chinese food and soups. This sodium salt is a naturally occurring amino acid glutamic acid. Often, MSG negatively affects certain people, by incurring headaches for example. All flavor enhancers exaggerate the taste of meat and are ionic compounds produced from organic acids.

Unfamiliar terms:
• Carrageenan: a carbohydrate extracted from Irish moss used as a thickening agent.
• Xanthan gum: a thickening agent.
• Locust bean gum: a thickening agent.
• Propylene glycol alginate: a modified natural substance used as a thickening agent.
• Monosodium glutamate: the sodium salt of the naturally occurring amino acid glutamic acid known as MSG.
• Disodium guanylate: a flavor enhancer.
• Disodium inosinate: a flavor enhancer.

Being a college student, I ingest candy, soda and goldfish daily. While this section of the text may not get me to cut out these food groups entirely, it has made me think twice about what I am putting into my body. While all of these substances are safe, because they are not all organic or natural, they cannot be very healthy or nutritious. I often read the back labels of the food substances I eat and drink and have wondered what some of these chemical names mean. I feel that now, even if I continue eating the unhealthy food I love so much, I will at least understand what I am ingesting. More often than not, food is bleached and colored to look like what consumers think it should look like. This makes me wonder why such products don’t already look as they are supposed to. It also worries me that there are food colorings that have been found to be carcinogenic in test animals, however, these additives have been banned in the United States. As for thickening agents and texture modifiers, I had no idea that I often eat derivatives of Irish moss. This fact might make me think twice before eating more Sour Patch Kids, but probably only for a moment. And finally, I had heard of the flavor enhancer MSG, but did not know the details of this additive. I did not know that it often has negative side effects such as headaches when added to Chinese food or soups. This makes me wonder why MSG is used so often. Also, I did not previously think about the fact that flavor enhancers not only exaggerate taste, but also allow producers to use less of the “real” thing and use inferior quality ingredients.

In the future, I hope that more organically grown products will be more widely used. Even though these food additives that have been certified in the United States are not hazardous, they still give us no nutritional value and can lead to poor health if consumed too regularly. After reading this section I was surprised to realize just how many of these additives I consume on any given day. Hopefully, new technology will start being used to make these additives in an organic and natural way. In the future I may think twice about what additives I consume and will also look more closely at the back labels of my food.

Baird, Colin. Chemistry in Your Life. W.H. Freeman & Company, New York. 2006. 385-386.

Chemicals in Food...Yum Yum!

Summary:
Although we may not notice it, many of the foods we eat contain coloring and bleaching agents to change the appearance of what we eat. Using these additives entices consumers to buy these products, that might otherwise appear boring or unappetizing. There are seven food colorings that the United States as certified to be acceptable for use. These colorings are: Blue No.1 and 2, Green No. 3, Red No. 40, Red No. 3, Yellow No. 5 and 6. The first, Brilliant Blue FCF, has a bright blue hue and is commonly used in beverages, dairy product powders, jellies and syrups. Indigotine (Blue No. 2) has a royal blue hue and is commonly used in baked goods, cereals, ice cream, and cherries. Fast Green FCF (Green No. 3) has a sea green hue and is also used for beverages, ice cream, sherbet, etc. Allura Red AC (Red No. 40) has an orange-red hue and is found in gelatins, condiments, and some beverages as well. Erythrosine (Red No. 3) is a cherry-red color and is found in canned fruits, confections, and snack foods. Tartrazine (Yellow No. 5) is a lemon yellow color and is found in custards, cereals, and confections. Lastly, Sunset Yellow (Yellow No. 6) is an orange color, found in dessert powders, baked goods, and beverages. Some colorings have been found to be carcinogenic, and these have been banned from use.
Thickening agents and texture modifiers are also used to alter the way food appears. Some are natural, such as carrageenan which comes from a moss in Ireland. Other natural agents include xanthan gum and locust been gum. For similar reasons, these agents are commonly used in many of the foods we eat. However, the most important additives in food are the flavor enhancers. MSG is more widely understood and popular than it was, and is found in many soups and Chinese cuisine. MSG, monosodium glutamate, is “the sodium salt of the naturally occurring amino acid glutamic acid.” Many people get very ill after consuming MSG, and minor symptoms are headaches and swelling. There are other flavor enhancers as well, but MSG is the most widely used. Flavor enhancers enhance the foods flavoring, allowing manufacturers or producers to use less-quality goods, or less amounts of goods.
Words:
Antioxidants- a substance that prevents the occurrence of oxidative damage from free radicals
Emulsifiers- substances that are soluble in two substances which are insoluble in each other and that enables them to form an emulsion
Reaction:
Although it is understandable to me why certain companies would see the benefits in using these additives with their foods, the use of these modifiers and agents in food is unhealthy and unnecessary. I have had personal negative experiences from eating food with MSG, such as severe headaches and an upset stomach. I believe, with the recent trend of environmentally-friendly products and going green, and just an overall desire to be more healthy, the use of these additives will decrease somewhat. Already we are seeing more and more products be “organic,” and while I realize that that term is quite vague, it is a step in the right direction.

Baird, Colin. Chemistry in Your Life. W.H. Freeman and Company: New York, 2006.

DNA Helps to Solve Crimes!

Summary
Crime scene investigators often look for fingerprints, blood types, and protein profiles to help solve crimes. Fingerprints are unique to each person and they are difficult to find a perfect print at a crime scene. Blood found at a crime scene can only show that there may be a connection between the suspect and the crime. Every individual’s blood is categorized into classifications such as type A, type B, type AB and type O. Although some of these blood groups are found more common than other individuals it can’t prove that because the suspect has the same blood type found at the crime scene they were the perpetrator. There is always something left behind in a crime scene from the criminal, it is just left up to the investigators to look for clues. For example, crime scene investigators look for clues that provide DNA evidence such as hair, saliva residue, or cells from fingernail scrapings. Due to the fact that DNA is unique to each individual, the evidence is used in courts to convict people. However, if the crime scene is not properly secure and the protocol to ensure evidence is tampered with, then the evidence may not be admissible in court. Once evidence is collected the technique polymerase chain reaction is used. For fingerprints the length of the of the DNA sequences vary amount people and can distinguish one individual from another. This technique is used to compare individuals directly to see if they match or not. It is best to use the DNA from the nucleus of cells. Mitochondrial DNA can be extracted from dead samples and can be easily mutated, thus making DNA from the nucleus of cells better for analysis.

Terms:
Polymerase chain reaction: a process that copies a small segment of DNA millions of times to obtain a sample large enough for analysis.

My Reaction
I think the fact that technology has progressed so significantly that crimes are able to be solved by molecular cells is amazing. Unfortunately, I know I personally like shows such as CSI and it really does provide a false truth as to what the crime scene investigators are capable of doing at crime scenes in a small amount of time. I think if technology keeps progressing it will provide an advantage for victims whose criminals who have not been yet convicted. It is also important to make sure that people know the unrealistic things that crime scene investigators can do because families who have been victim to crime get upset when they set standards that are too high and unrealistic for the those trying to help solve the crime.

PCBs, Furons, and Dioxins Are No Fun

Supplemental Reading 10.19 discusses the health problems that PCBs, furans, and dioxins can cause in humans. Over the past few years, scientists have learned a great deal about the impact exposure to PCBs can have on human health. The most common effect of high levels of exposure to PCBs is chloracne, a disfiguring acne. Scientists have also discovered that PCBs have a toxic effect on human reproduction. Scientists fear that PCBs have done the most reproductive damage to women who have consumed large amounts of fish which had PCBs stored in their fatty tissue. By conducting studies on the children of these mothers, scientists were able to deduce that PCBs toxic effects on the reproduction process can disrupt the cognitive development of the child. The reading goes on to discuss a recent U.S. Environmental Protection Agency report which stated that 2,3,7,8- TCDD is a human carcinogen, meaning that it is highly likely that the mixture of PCDDs is also a carcinogen. The report also states that, in addition to cancer, these compounds could also have serious effects on reproduction, sexual development, and the immune system. A frightening estimate from this report states that “an upper limit of one thousand of the one million new cancer cases diagnosed each year in the United States could arise from the intake of a mixture of dioxins, furans, and PCBs (Baird, 404).” The reading concludes with a discussion of the debate over how dangerous PCBs really are. While some groups believe that the negative effects of PCBs have been blown out of proportion, others argue that the high levels of PCBs in our environment have most certainly caused negative effects to human health. The debate continues to rage on as scientists seek a greater understanding of the impact PCBs have had on our lives.

Unknown Terms
PCBs (polychlorinated biphenyls): a group of industrial organochlorine chemicals that became a major environmental concern in the 1980s and 1990s.
Chloracne: a disfiguring acne that is characteristic of exposure to organochlorine compounds
Dibenzofuran: These compounds are structurally similar to dioxins; they differ in that they are missing one oxygen in the central ring. The dibenzofurans give rise to health effects similar to those of dioxins. Their production is the result of strong heating of PCBs in the presence of a source of oxygen.
2,3,7,8-TCDD: the most potent carcinogen known
Before reading this, I had never heard of PCBs, let alone the health problems they can cause. It makes me happy I’m a vegetarian so I won’t be eating any fish full of PCBs anytime soon. However, from what I got from the reading, it seems as though, no matter what I do, I could possibly be exposed to PCBs. Moreover, the reading didn’t offer any kind of solution to this problem. It seems as though more research has to be conducted before any major initiatives against PCBs are undertaken. I can’t offer much of my own opinion on this subject because, admittedly, much of the reading went over my head. However, I hope that someone with a better understanding of PCBs will soon be able to prevent it from causing further health problems to humans and animals.

Baird, Colin. “10.19 The Health Effects of PCBs, Furans, and Dioxins.” Chemistry In Your Life. 2nd ed. New York: W.H. Freeman and Company, 2006.

Eww! That is too sour!

There are foods and beverages that when consumed taste sour to us. How does that happen exactly? The H+ ions react with some of the molecules on the side the tongue and then an action is sent to the brain telling it that it “sour.” Weak acids, that have a low pH number, are that give the sour or tangy taste to drinks and other foods. Citrus fruits like lemons, limes or oranges have citric acid as well which contributes to the week acids.

This is what makes foods and beverages sour. If consumed a lot in a short amount of time the tongue does get “injured” and eating after that is painful for some people. It is as though the acid is attacking your tongue. Another way that is easily seen how acid react in your tongue after having a large quantity is with candy. If consumed enough sour skittles you can cause your tongue to bleed and after it is very hard to eat or drink anything without being uncomfortable.

What's in your water?

Although some may oppose chlorination, there are significant health advantages of disinfecting water that you drink. Before chlorination was widespread diseases such as typhoid and cholera spread across America because of bacterial infested drinking water. Poor drinking water also affects the lives of peoples in other countries as well. In Peru in the 1990’s there were almost half a million of cases of cholera reported because drinking water was not chlorinated. The reason that some people are against chlorination is because they are fearful of the by-products. Although people may think that unsafe drinking water only affects developing countries, there have been many recent cases of diseases linked to poor drinking water in the United States as well. In Milwaukee in 1993, Oxford in 1989, and in North Battleford in 2001 a deadly parasite killed many people and caused hundreds of thousands of cases of diarrhea. Chlorination and chlorine dioxide do not have a huge effect on the parasite and the only effective methods of disinfectant against it are ozonation and ultraviolet treatment. Although disinfectants usually work very well the equipment can sometimes break and unhealthy water can be distributed to the public.

Unfamiliar Terms
Chlorination: a common water purification process; the use of hypochlorous acid
(HOCL) to disinfect water.
Ozonation: the use of ozone to disinfect water supplies. Ozone air is bubbled through
water for about 10 minutes to kill waterborne viruses.
Ultraviolet treatment: the use of ultraviolet light to disinfect and purify water. Powerful
lamps containing mercury vapor, which emit ultraviolet light are immersed in the water flow. After a few seconds toxic microorganisms are destroyed.

The Sections in chapter 13 right before the short exert helped me understand the process of chlorination, ozonation and ultraviolet treatment and showed me the advantages and disadvantages of each. When most people, including myself, think of chlorination they think of chlorine swimming pools. People are turned off by the term “chlorination” because they imagine drinking swimming pool water. The chlorination of drinking water is not the same thing as the chlorination of swimming pools. In chlorination HOCL is used to kill microorganisms. Unlike swimming pool water, drinking water does not need to be continually disinfected. Swimming pool water must be constantly disinfected because microorganisms can build up in the pool. A high level of HOCl must be maintained. Some people are against chlorination because products of chlorinated organic substances are inevitable, are formed during chlorination and can be toxic. If water contains phenol, chlorinated phenols will form which have nasty odors and tastes and are toxic. Another compound that forms that concerns people is chloroform and even small amounts of chloroform in drinking water raises concern. Chloroform is a supposed liver carcinogen and can also have effects on the reproductive system. Besides these two other chlorinated organic compounds have cause DNA mutations. Because of these risks come places have stopped chlorination and have used ozone or chlorine dioxide instead.

After reading all of these sections (13.10- 13.17) I can see the advantages of chlorination, the inexpensive price and the almost certain disinfection of water; but I am also concerned about the health risks. Obviously any disinfectant is better than none, but I think communities should try to find and use the safest ways possible to disinfect drinking water. If ozone, ultraviolet light, and chlorine dioxide are safer than chlorination then those methods should be used even if they are more expensive. I think there is a general lack of knowledge about drinking water in the United States. Everyday we just turn on our faucets, showers, or sinks and use water without knowing where it came from and what is in it. Some people use distillers or other forms of disinfection, but there are many people in the country that are poor and are not educated about the water they are drinking. These are probably the areas where unhealthy water is most likely to be found. Water is such an important part of everyday life and more serious measures should be taken to make sure that everyone gets clean water around the United States and around the world.

Colin Baird. “the advantages of disinfecting drinking water”, Chemistry In Your Life. 2nd ed. 2006. 498-499

Colin Baird. Chemistry In Your Life. 2nd ed. 2006 493-499