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Science Facts About Cats

Posted on April 4, 2013  Comments (0)

Related: Domestic Cats Remain Successful Predators – Backyard Wildlife: Mountain Lion – Friday Fun: Cats and Kids with iPads

People are Superorganisms With Microbiomes of Thousands of Species

Posted on February 25, 2013  Comments (2)

In a recent article in National Geographic Carl Zimmer has again done a good job of explaining the complex interaction between our bodies and the bacteria and microbes that make us sick, and keep us healthy.

The damage done by our indiscriminate use of antibiotics is not just the long term resistance that we create in bacteria (making the future more dangerous for people) that I have written about numerous times but it also endangers the person taking the anti-biotics in the short term. Sometimes the other damage is a tradeoff that should be accepted. But far too often we ignore the damage taking antibiotics too often does.

When You Swallow A Grenade

While antibiotics can discriminate between us and them, however, they can’t discriminate between them and them–between the bacteria that are making us sick and then ones we carry when we’re healthy. When we take a pill of vancomycin, it’s like swallowing a grenade. It may kill our enemy, but it kills a lot of bystanders, too.
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If you think of the human genome as all the genes it takes to run a human body, the 20,000 protein-coding genes found in our own DNA are not enough. We are a superorganism that deploys as many as 20 million genes.
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Before he started taking antibiotics, the scientists identified 41 species in a stool sample. By day 11, they only found 13. Six weeks after the antibiotics, the man was back up to 38 species. But the species he carried six weeks after the antibiotics did not represent that same kind of diversity he had before he took them. A number of major groups of bacteria were still missing.
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They found that children who took antibiotics were at greater risk of developing inflammatory bowel disease later in life. The more antibiotics they took, the greater the risk. Similar studies have found a potential link to asthma as well.

The human body contains trillions of microorganisms — outnumbering human cells by 10 to 1. Because of their small size, however, microorganisms make up only about 1% to 3% of the body’s mass, but play a vital role in human health.

Where doctors had previously isolated only a few hundred bacterial species from the body, Human Microbiome Project (HMP) researchers now calculate that more than 10,000 microbial species occupy the human ecosystem. Moreover, researchers calculate that they have identified between 81% and 99% of all microorganismal genera in healthy adults.

“Humans don’t have all the enzymes we need to digest our own diet,” said Lita Proctor, Ph.D., NHGRI’s HMP program manager. “Microbes in the gut break down many of the proteins, lipids and carbohydrates in our diet into nutrients that we can then absorb. Moreover, the microbes produce beneficial compounds, like vitamins and anti-inflammatories that our genome cannot produce.” Anti-inflammatories are compounds that regulate some of the immune system’s response to disease, such as swelling.

“Enabling disease-specific studies is the whole point of the Human Microbiome Project,” said Barbara Methé, Ph.D., of the J. Craig Venter Institute, Rockville, MD, and lead co-author of the Nature paper on the framework for current and future human microbiome research. “Now that we understand what the normal human microbiome looks like, we should be able to understand how changes in the microbiome are associated with, or even cause, illnesses.”

Read the full NIH press release on the normal bacterial makeup of the body

Related: Tracking the Ecosystem Within Us – What Happens If the Overuse of Antibiotics Leads to Them No Longer Working? – Antibacterial Products May Do More Harm Than Good – Antibiotics Too Often Prescribed for Sinus Woes

Human Gene Origins: 37% Bacterial, 35% Animal, 28% Eukaryotic

Posted on February 17, 2013  Comments (3)

The percent of human genes that emerged in various stages of evolution: 37% bacterial, 28% eukaryotic, 16% animal, 13% vertebrate, 6% primate. The history that brought us to where we are is amazing. Eukaryotes include animals, plants, amoebae, flagellates, amoeboflagellates, fungi and plastids (including algae). So eukaryotic genes are those common to us and other non-animal eukaryotes while those classified as animal genes are shared by animals but not non-animal eukaryotes.

We are living in a bacterial world, and it’s impacting us more than previously thought by Lisa Zyga

Bacterial signaling is not only essential for development, it also helps animals maintain homeostasis, keeping us healthy and happy. As research has shown, bacteria in the gut can communicate with the brain through the central nervous system. Studies have found that mice without certain bacteria have defects in brain regions that control anxiety and depression-like behavior. Bacterial signaling also plays an essential role in guarding an animal’s immune system. Disturbing these bacterial signaling pathways can lead to diseases such as diabetes, inflammatory bowel disease, and infections. Studies also suggest that many of the pathogens that cause disease in animals have “hijacked” these bacterial communication channels that originally evolved to maintain a balance between the animal and hundreds of beneficial bacterial species.
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Scientists have also discovered that bacteria in the human gut adapts to changing diets. For example, most Americans have a gut microbiome that is optimized for digesting a high-fat, high-protein diet, while people in rural Amazonas, Venezuela, have gut microbes better suited for breaking down complex carbohydrates. Some people in Japan even have a gut bacterium that can digest seaweed. Researchers think the gut microbiome adapts in two ways: by adding or removing certain bacteria species, and by transferring the desired genes from one bacterium to another through horizontal gene transfer. Both host and bacteria benefit from this kind of symbiotic relationship, which researchers think is much more widespread than previously thought.
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We want badly for the message in ‘Animals in a bacterial world,’ to be a call for the necessary disappearance of the old boundaries between life science departments (e.g., Depts of Zoology, Botany, Microbiology, etc.) in universities, and societies (e.g., the American Society for Microbiology, etc.). We also want the message disseminated in college and university classes from introductory biology to advanced courses in the various topic areas of our paper.”

Very cool stuff. This amazing facts scientists discover provide an amazing view of the world we live in and how interconnected we are to other life forms in ways we don’t normally think of.

Related: People’s Bodies Carry More Bacterial Cells than Human Cells – Microbes Flourish In Healthy People – Tracking the Ecosystem Within Us – Foreign Cells Outnumber Human Cells in Our Bodies – Bacteria Beneficial to Human Health

Quick Webcast With a Few Interesting Science Facts

Posted on January 7, 2013  Comments (1)

Interesting facts: I didn’t know that we require 13 minerals or that alcoholic beverages contain amounts of all the minerals we need. An amazing fact: the average person walks the equivalent of 3 times around the earth in a lifetime.

The minerals we need (and the recommended daily amount)

Calcium – 1,200 mg
Magnesium – 320 mg
Phosphorus – 700 mg
Potassium – 4.7 g
Sodium – ?
Chloride?

trace amounts needed
Cobalt (as Vitamin B12) – 2.4 mcg
Copper – 1,156 mcg
Iodine – 150 mcg
Iron – 8 mg
Manganese – 1.8 mg
Niacin – 14 mg
Riboflavin – 1.1 mg
Selenium – 55 mcg
Thiamin – 1.1 mg
Zinc – 8 mg
Chromium?, Molybdenum? Fluoride?

Frankly, in my quick looks around the internet I am not sure what they base the claim we need only 13 minerals on. It seems we need trace amounts of more minerals – did they just ignore those not in alcohol?

I couldn’t find good sources confirming just what minerals are needed. Many list some minerals but don’t list others. I am not really sure what the answer is. I am glad I seem to somehow get whatever I need just by eating somewhat healthfully. It is pretty cool we get these things that way. Of course if we didn’t our ancestors wouldn’t have survived to create descendants that finally became us – as they had a much harder time than me (who can just go the restaurant and grocery store and get all sorts of wonderful food).

Related: the atoms that make up the human body, were created in the crucible of stars – Science Explained: Cool Video of ATP Synthase, Which Provides Usable Energy to Us – Video of Young Richard Feynman Talking About Scientific Thinking – Scientific Illiteracy Leads to Failure to Vaccinate Which Leads to Death

How Caffeine Affects Your Body

Posted on November 15, 2012  Comments (15)

From the video by Alex Dainis: Caffeine prevents adenosine from slowing down your nervous system, by binding to the same receptors adenosine would. Caffeine also stimulates the production of adrenaline. And it increases the amount of dopamine present. The average half life of caffeine in the human body is about 6 hours.

Related: Does Diet Soda Result in Weight Gain? – Mental Pick-Me-Ups: The Coming Boom – Ritalin Doesn’t Show Long Term Effectiveness for ADHD

I have been curious about the caffeine content of various drinks and writing this post is a good enough reason to actually look it up.

  • expresso (2oz) 100 mg (varies – 60 mg to 180 mg)
  • coffee (8oz) 100 mg – this can vary quite a bit, 50 to over 100 mg is common. Brewed coffee has more caffeine 100-200 mg.
  • Red Bull (8.2 oz) 80 mg
  • tea (8oz) 20 to 80 mg (depending on strength and type, can also be higher, green tea is on the lower end)
  • Mountain Dew (12 oz) 54 mg (diet has 54 mg also)
  • Diet Coke 46 mg (regular Coke 34mg)
  • Pepsi 38 mg, Diet Pepsi 36 mg

Sprite, 7Up and some root beers have no caffeine.
Chocolate can also be a significant source of caffeine – dark chocolate can have over 80 mg per 100 g (approximately 4 ounces).

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

Posted on October 17, 2012  Comments (2)

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 Medicine – Nobel Prize in Physiology or Medicine 2008 – 2012 Nobel Prize in Chemistry to Robert Lefkowitz and Brian Kobilka

Continue reading →

Why is the Sky Dark at Night?

Posted on October 11, 2012  Comments (8)

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

Posted on October 4, 2012  Comments (3)

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.
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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.
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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 Future – European Eels in Crisis After 95% Decline in Last 25 years – Let the Good Times Roll (using Credit) – SelFISHing – Running Out of Fish – The State of the Oceans is Not Good – Chinook Salmon Vanish Without a Trace

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

Posted on September 17, 2012  Comments (2)

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 Illinois – Webcast on the makeup and function of eukaryotic cells – Science Explained: Photosynthesis – Video showing malaria breaking into cell

Great Webcast Explaining the Digestive Systems

Posted on August 11, 2012  Comments (0)

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 Poisoning – Energy Efficiency of Digestion – Tracking the Ecosystem Within Us – Waste from Gut Bacteria Helps Host Control Weight

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

Posted on July 29, 2012  Comments (2)

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 Inaction – Study Finds Obesity as Teen as Deadly as Smoking – Can 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.

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