Posts about science facts

Nobel Prize in Physiology or Medicine 2012 for Reprogramming Cells to be Pluripotent

The Nobel Prize in Physiology or Medicine 2012 was awarded “for the discovery that mature cells can be reprogrammed to become pluripotent.” The prize goes jointly to Sir John B. Gurdon, Gurdon Institute in Cambridge, UK and Shinya Yamanaka, Kyoto University (he is also a senior investigator at the Gladstone Institutes in the USA).

The Nobel Prize recognizes two scientists who discovered that mature, specialised cells can be reprogrammed to become immature cells capable of developing into all tissues of the body. Their findings have revolutionised our understanding of how cells and organisms develop.

John B. Gurdon discovered (in 1962) that the specialisation of cells is reversible. In a classic experiment, he replaced the immature cell nucleus in an egg cell of a frog with the nucleus from a mature intestinal cell. This modified egg cell developed into a normal tadpole. The DNA of the mature cell still had all the information needed to develop all cells in the frog.

Shinya Yamanaka discovered more than 40 years later, in 2006, how intact mature cells in mice could be reprogrammed to become immature stem cells. Surprisingly, by introducing only a few genes, he could reprogram mature cells to become pluripotent stem cells, i.e. immature cells that are able to develop into all types of cells in the body.

These groundbreaking discoveries have completely changed our view of the development and cellular specialisation. We now understand that the mature cell does not have to be confined forever to its specialised state. Textbooks have been rewritten and new research fields have been established. By reprogramming human cells, scientists have created new opportunities to study diseases and develop methods for diagnosis and therapy.

All of us developed from fertilized egg cells. During the first days after conception, the embryo consists of immature cells, each of which is capable of developing into all the cell types that form the adult organism. Such cells are called pluripotent stem cells. With further development of the embryo, these cells give rise to nerve cells, muscle cells, liver cells and all other cell types – each of them specialised to carry out a specific task in the adult body. This journey from immature to specialised cell was previously considered to be unidirectional. It was thought that the cell changes in such a way during maturation that it would no longer be possible for it to return to an immature, pluripotent stage.

Related: 2011 Nobel Prize in Physiology or MedicineNobel Prize in Physiology or Medicine 20082012 Nobel Prize in Chemistry to Robert Lefkowitz and Brian Kobilka

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Why is the Sky Dark at Night?

The answer isn’t quite as simple as it seems. I find the wording in the video a bit confusing.

The point I believe, is that the sky is dark instead of light. But not that the brightness would be huge (so for example, you couldn’t necessarily read my book outside just by starlight). The light would be very faint, it is just that it would be lightish instead of blackish, due to the reasons explained (redshift etc.). At least that is my understanding.

Related: Why is it Colder at Higher Elevations?Why Does the Moon Appear Larger on the Horizon?Why is the Sky Blue?Why Wasn’t the Earth Covered in Ice 4 Billion Years Ago – When the Sun was Dimmer

Add Over-Fishing to the Huge Government Debt as Examples of How We Are Consuming Beyond Our Means

Fish are hidden under the water so the unsustainable harvesting isn’t quite as obvious as the unsustainable government debt but they both are a result of us living beyond our sustainable production. You can live well by consuming past wealth and condemning your decedents to do without. That is the way we continue to live. Over-fishing a century ago was not as obviously dangerous as it is today. But we have witnessed many instances of overfishing devastating the fishing economy (when the fishing is unsustainable the inevitable result is collapse and elimination of the vast majority of the food and income that previous generations enjoyed).

The normal pattern has been to turn to more aggressive fishing methods and new technology to try and collect fish as over-fishing devastates yields. This, of course, further devastates the state of the resources and makes it so recovery will take much much longer (decades – or more).

New research shows the existing problems and the potential if we apply science and planning to manage fisheries effectively.

Using new methods to estimate thousands of unassessed fisheries, a new comprehensive study provides a new view of global fish stocks. The results show that the overall state of fisheries is worse than previously thought. Unassessed stocks, which are often left out of global analyses because of a lack of data, are declining at disturbing rates. When these fisheries are taken into account, the results indicate that over 40 percent of fisheries have crashed or are overfished, producing economic losses in excess of $50 billion per year.

The good news is that this decline is not universal: fisheries are starting to rebound in many areas across the globe and we can learn from these examples. Recovery trends are strongest for fisheries where data on the status of the fishery exists, and in which managers and fishermen have made science-based decisions and stuck with them in the face of political pressure.

The amount of fish brought to shore could increase 40 percent on average – and double in some areas – compared to yields predicted if we continue current fishing trends.

The management solutions to overfishing are well known, tested and proven to work. While these solutions are not “one-size-fits-all” for fisheries, there are common themes. Specifically, managers and fishermen must: 1. Reduce fishing to allow stocks to rebuild; 2. Set catches at a sustainable level that is based on the best available scientific and economic information rather than short-term political pressures; and 3. Prevent dangerous fishing activities that destroy habitat, wildlife, or breeding fish.

The over fishing problem is difficult because our nature is to ignore problems that are not immediate. But the costs of doing so are very large. If we don’t behave more wisely our children will pay the price. And, in fact, this problem is so acute now that those of us that expect to live a couple decades can expect to pay the price. In rich countries this will be tolerable, a bit less fish at much higher prices. In rich countries food prices are a minor expense compared to the billions of those not living in rich countries. They will suffer the most. As will those that have jobs directly dependent on fishing.

Related: Fishless FutureEuropean Eels in Crisis After 95% Decline in Last 25 yearsLet the Good Times Roll (using Credit)SelFISHingRunning Out of FishThe State of the Oceans is Not GoodChinook Salmon Vanish Without a Trace

Science Explained: Cool Video of ATP Synthase, Which Provides Usable Energy to Us

This webcast shows animations of ATP synthase structure and the mechanism for synthesizing ATP. Biology is incredibly cool. Too bad they didn’t have stuff like this when I was in school, instead biology was mainly about memorizing boring lists of stuff.

ATP (adenosine tri-phosphate) transports chemical energy within cells. When one of the phosphates is released by ATP energy is given off (and ATP becomes ADP (adenosine di-phosphate) + Pi (inorganic phosphate). And then the synthase structure can then turn it back into ATP to be used again.

The human body, which on average contains only 250 grams of ATP, turns over its own body weight equivalent in ATP each day.

Related: ATP synthase lecture notes University of IllinoisWebcast on the makeup and function of eukaryotic cellsScience Explained: PhotosynthesisVideo showing malaria breaking into cell

Great Webcast Explaining the Digestive Systems

You will learn things like why it is so important to chew your food well (increase the surface area for enzymes to get at the food). Our bodies also have adapted to provide a huge surface area for the digestive system to work; the small intestine alone has a surface area of 250 square meters (larger than the size of most apartments). Your small intestine is 4.5 to 10.5 meters long.

Related: Staphylococcal Food PoisoningEnergy Efficiency of DigestionTracking the Ecosystem Within UsWaste from Gut Bacteria Helps Host Control Weight

Physical Activity for Adults: Inactivity Leads to 5.3 Million Early Deaths a Year

Obviously health care doesn’t only mean sickness treatment. Avoiding sickness is much better than treating it. Sadly we spend far too little energy on creating health and far too much on treating sickness.

Physical activity guidelines for adults (follow link for more details and guidelines for others) from the UK National Health Service

To stay healthy, adults aged 19-64 should try to be active daily and should do:

  • At least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity such as cycling or fast walking every week, or
  • 75 minutes (1 hour and 15 minutes) of vigorous-intensity aerobic activity such as running or a game of singles tennis every week
  • and muscle-strengthening activities on 2 or more days a week that work all major muscle groups (legs, hips, back, abdomen, chest, shoulders and arms).

Sedentary lifestyle can kill

one in three adults worldwide fails to do the recommended 150 minutes of moderate aerobic physical activity per week. In the UK two out of three adults don’t manage it.

So rather than stressing the health benefits of exercise, the Lancet researchers have opted to show the harm caused by inactivity. They estimate lack of exercise is responsible for about 5.3m deaths a year – about the same number as smoking.

This is based on estimates of the impact on inactivity on coronary heart disease, Type 2 diabetes, and two specfic cancers – breast and bowel – where lack of exercise is a major risk factor.

Related: Today, Most Deaths Caused by Lifetime of InactionStudy Finds Obesity as Teen as Deadly as SmokingCan Just A Few Minutes of Exercise a Day Prevent Diabetes?An Apple a Day is Good Advice

Effect of physical inactivity on major non-communicable diseases worldwide: an analysis of burden of disease and life expectancy

Worldwide, we estimate that physical inactivity causes 6% (ranging from 3·2% in southeast Asia to 7·8% in the eastern Mediterranean region) of the burden of disease from coronary heart disease, 7% (3·9—9·6) of type 2 diabetes, 10% (5·6—14·1) of breast cancer, and 10% (5·7—13·8) of colon cancer. Inactivity causes 9% (range 5·1—12·5) of premature mortality, or more than 5·3 million of the 57 million deaths that occurred worldwide in 2008. If inactivity were not eliminated, but decreased instead by 10% or 25%, more than 533 000 and more than 1·3 million deaths, respectively, could be averted every year. We estimated that elimination of physical inactivity would increase the life expectancy of the world’s population by 0·68 (range 0·41—0·95) years.

Scientific Illiteracy Leads to Failure to Vaccinate Which Leads to Death

Anti-vaccination propagandists help create the worst whooping cough epidemic in 70 years by Steven Salzberg is a professor at Johns Hopkins School of Medicine:

When the vaccination rates drop, everyone becomes more vulnerable to infectious diseases. When more than 90% of the population is vaccinated, we have “herd immunity” – this means the disease can’t spread because there aren’t enough susceptible people in the community. So the high rate of vaccine refusal in Washington makes it easier for whooping cough (and other diseases) to spread.

And now we learn that the U.S. is in the midst of the worst whooping cough epidemic in 70 years. One of the most hard-hit states is Washington, which the CDC just announced (on 20 July) has suffered 2,520 cases so far this year, a 1300% increase over last year. This is the highest number of cases reported in Washington since 1942.

The U.S. has had over 17,000 cases this year, putting it on track for the worst year since 1959. The highest rate of infection in the nation is in Wisconsin (which has also been hit hard by anti-vaccine effects), followed by Washington and Montana. 10 deaths have been reported, mostly in infants who were too young to be vaccinated. For all this, we can thank the anti-vaccination movement.

The failure of our society to appreciate the value of science has dire consequences. We are lucky to benefit from the results of scientific advances around us everyday. Some people, instead of appreciating the value of science waste these great gifts we have been given.

What people want to believe is up to them. When people’s actions risk others lives that is not ok. Drunk drivers risk others lives; therefore we don’t allow drunk driving. Society requires that people respect others right to live. It is sensible to require people to cooperate to limit damaging behavior: such as drunk driving or not being properly vaccinated.

Pertussis (whooping cough) is a highly contagious bacterial disease that causes uncontrollable, violent coughing. The coughing can make it hard to breathe. Pertussis, or whooping cough, is an upper respiratory infection caused by the Bordetella pertussis or Bordetella parapertussis bacteria. It is a serious disease that can cause permanent disability in infants, and even death.

Related: Vaccines Can’t Provide Miraculous Results if We Don’t Take ThemDeadly Choices: How the Anti-Vaccine Movement Threatens Us All (book)CDC Report on Failures to VaccinateOur Dangerous Antibiotic Practices Carry Great Risks

The Chemistry of Fireworks

The video features John A. Conkling, Ph.D., who literally wrote the book on fireworks — he is the author of The Chemistry of Pyrotechnics.

The earliest documentation of fireworks dates back to 7th century China.

A Syrian named Hasan al-Rammah wrote of rockets, fireworks, and other incendiaries, using terms that suggested he derived his knowledge from Chinese sources, such as his references to fireworks as “Chinese flowers”.

Chinese fireworks began to gain popularity around the mid-17th century.

Related: Cooking with Chemistry, Hard CandyThe Chemistry of CookingVideo of Briggs-Rauscher Oscillating Chemical Reaction

Video of Young Richard Feynman Talking About Scientific Thinking

The enjoyable video above shows a young Richard Feynman discussing how scientific thinking can advance our understanding of the world.

Related: Feynman “is a second Dirac, only this time human”Science and the Excitement, the Mystery and the Awe of a FlowerClassic Feynman: All the Adventures of a Curious Character

Using Nanocomposites to Improve Dental Filling Performance

After a dentist drills out a decayed tooth, the cavity still contains residual bacteria. Professor Huakun (Hockin) Xu says it is not possible for a dentist to remove all the damaged tissue, so it’s important to neutralize the harmful effects of the bacteria, which is just what the new nanocomposites are able to do.

Rather than just limiting decay with conventional fillings, the new composite he has developed is a revolutionary dental weapon to control harmful bacteria, which co-exist in the natural colony of microorganisms in the mouth.

“Tooth decay means that the mineral content in the tooth has been dissolved by the organic acids secreted by bacteria residing in biofilms or plaques on the tooth surface. These organisms convert carbohydrates to acids that decrease the minerals in the tooth structure,” says Xu, director of the Division of Biomaterials and Tissue Engineering in the School’s Department of Endodontics, Prosthodontics and Operative Dentistry.

The researchers also have built antibacterial agents into primer used first by dentists to prepare a drilled-out cavity and into adhesives that dentists spread into the cavity to make a filling stick tight to the tissue of the tooth. “The reason we want to get the antibacterial agents also into primers and adhesives is that these are the first things that cover the internal surfaces of the tooth cavity and flow into tiny dental tubules inside the tooth,” says Xu.

The main reason for failures in tooth restorations, says Xu, is secondary caries or decay at the restoration margins. Applying the new primer and adhesive will kill the residual bacteria, he says.

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New Blog with Simple Demonstrations and Scientific Explanations

Try this at home is a new blog by Dr Mark Lorch, a chemistry lecturer at the University of Hull, with instructions for the citizen scientist. This example shows how to move a can with a ballon without touching the can.

The posts include instructions on how to do these simple demonstrations and a nice explanation on the scientific reason for what is going on:

Rubbing the balloon on your hair charges it up with static electricity which makes the balloon negatively charged. When you put the balloon near the can it pushes electrons (which are also negatively charged) to the other side of the can. This makes the side which is nearest the balloon positively charged. Positive charges are attracted to negative charges so the can moves towards the balloon.

It is quite a nice site (especially if you have kids interested in science or are a kid interested in science – no matter how old you are), add it to your RSS reader. Here are some more science blogs you may enjoy.

Related: The DIY Movement Revives Learning by DoingHome Engineering: Building a HovercraftTeaching Through Tinkering

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