Tag Archives: science facts

Monarch Butterflies Use Medicinal Plants

Monarch butterflies eat toxic plants (that they have evolved to tolerate and make the butterflies themselves toxic to predators). They use medicinal plants to treat their offspring for disease, research by Emory biologists shows. When the butterflies are infected by certain parasites the butterflies have a strong preference to lay their eggs on a plant (tropical milkweed) that will help the caterpillar fight the parasite when it eats those leaves (it serves as a drug for them). Their experiments may be the best evidence to date that animals use medication.

The Mystery of Empty Space

Get ready to re-think your ideas of reality. Join UCSD physicist Kim Griest as he takes you on a fascinating excursion, addressing some of the massive efforts and tantalizing bits of evidence which suggest that what goes on in empty space determines the properties of the three-dimensional existence we know and love, and discusses how that reality may be but the wiggling of strings from other dimensions.

CDC Urges Reduction in Salt Intake to Save Hundreds of Thousands of Lives

Most people know we eat far too much salt and that it is killing lots of us. It is still amazing that we have over 100,000 people in the USA every year die this way and yet we barely pay attention. Doesn’t it seem like we should care more about life?

Excessive dietary sodium consumption increases blood pressure, which increases the risk for stroke, coronary heart disease, heart failure, and renal disease. Based on predictive modeling of the health benefits of reduced salt intake on blood pressure, a population-wide reduction in sodium of 1,200 mg/day would reduce the annual number of new cases of coronary heart disease by 60,000—120,000 cases and stroke by 32,000—66,000 cases.

Fewer than 10% of all adults in the USA met their recommended limit. U.S. adults consumed an average of 3,466 mg/day of sodium. Most of the daily sodium consumed came from grains (1,288 mg; 36.9%) and meats, poultry, fish, and mixtures (994 mg; 27.9%).

In the United States, an estimated 77% of dietary sodium intake comes from processed and restaurant foods and approximately 10% comes from table salt and cooking. More details from the CDC.

Vaccines Can’t Provide Miraculous Results if We Don’t Take Them

Vaccine preventable diseases used to ravage our health. In the USA, we are lucky to live in a society where those before us have taken vaccines and reduced to very low levels the attack vectors for these diseases. If nearly everyone is vaccinated for polio, even if it crops up with one person, most likely it won’t spread. As more people chose to risk the health of others in the society by failing to vaccinate, an infection can spread rapidly. There are some people who can’t be vaccinated for one reason or another (normally dangerous allergies) and vaccines, while very effective are not 100% effective. So any person that fails to vaccinate their kids endangers society and those who cannot be vaccinated.

Six Top Vaccine Myths

Myth 1: It’s not necessary to vaccinate kids against diseases that have been largely eradicated in the United States.
Reality: Although some diseases like polio and diphtheria aren’t often seen in America (in large part because of the success of the vaccination efforts), they can be quite common in other parts of the world. The Centers for Disease Control and Prevention warns that travelers can unknowingly bring these diseases into the United States, and if we were not protected by vaccinations, these diseases could quickly spread throughout the population. At the same time, the relatively few cases currently in the U.S. could very quickly become tens or hundreds of thousands of cases without the protection we get from vaccines. Brown warns that these diseases haven’t disappeared, “they are merely smoldering under the surface.”

Most parents do follow government recommendations: U.S. national immunization rates are high, ranging from 85 percent to 93 percent, depending on the vaccine, according to the CDC.

See the 2010 Child & Adolescent Immunization Schedules from the CDC and protect your children and society. The suffering caused by preventable diseases like polio and small pox was huge. We should not delude ourselves into thinking that those diseases are not dangerous. They are. We have been protected by all those taking vaccines. If people in the society don’t take vaccines that increases the health risks to the society at large.

Routine smallpox vaccination among the American public stopped in 1972 after the disease was eradicated in the United States. The United States government has enough vaccine to vaccinate every person in the United States in the event of a smallpox emergency (mainly due to concerns about bio-terrorism).

U.S. Adults Dying of Preventable Diseases

Diseases easily preventable by adult vaccines kill more Americans each year than car wrecks, breast cancer, or AIDS.
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“We have a chronic disease epidemic in the U.S. It is taxing our families and taxing our economy,” the CDC’s Anne Schuchat, MD, said at the news conference. “We have a need for culture change in America. We worry about things when they are really bad rather than focusing on prevention, which can keep us out of the hospital and keep our families thriving.”

In other parts of the world the danger is not from those who chose not to vaccinate their children but those who are not provided the opportunity to.

Bill Gates’ war on disease, poverty is an uphill battle
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Parasites in the Gut Help Develop a Healthy Immune System

It has long been known that microbes in the gut help to develop a healthy immune system, hence the rise in popularity of probiotic yoghurts that encourage ‘friendly’ bacteria. But new research by Professors Richard Grencis and Ian Roberts shows that larger organisms such as parasitic worms are also essential in maintaining our bodily ‘ecosystem’. “The worms have been with us throughout our evolution and their presence, along with bacteria, in the ecosystem of the gut is important in the development of a functional immune system.”

Parasite Rex is a great book, I have written about previously looking at parasites and their affect on human health.

Professor Grencis adds: “If you look at the incidence of parasitic worm infection and compare it to the incidence of auto-immune disease and allergy, where the body’s immune system over-reacts and causes damage, they have little overlap. Clean places in the West, where parasites are eradicated, see problems caused by overactive immune systems. In the developing world, there is more parasitic worm infection but less auto-immune and allergic problems.

“We are not suggesting that people deliberately infect themselves with parasitic worms but we are saying that these larger pathogens make things that help our immune system. We have evolved with both the bugs and the worms and there are consequences of that interaction, so they are important to the development of our immune system.”

Whipworm, also known as Trichuris, is a very common type of parasitic worm and infects many species of animals including millions of humans. It has also been with us and animals throughout evolution. The parasites live in the large intestine, the very site containing the bulk of the intestinal bacteria.

Heavy infections of whipworm can cause bloody diarrhoea, with long-standing blood loss leading to iron-deficiency anaemia, and even rectal prolapse. But light infections have relatively few symptoms.
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A Breakthrough Cure for Ebola

A breakthrough cure for Ebola By Steven Salzberg

Last week, in what may be the biggest medical breakthrough of its kind in years, a group of scientists published results in The Lancet describing a completely new type of anti-viral treatment that appears to cure Ebola. They report a 100% success rate, although admittedly the test group was very small, just 4 rhesus monkeys.

This is a breakthrough not only because it may give us a cure for an uncurable, incredibly nasty virus, but also because the same method might work for other viruses, and because we have woefully few effective antiviral treatments. We can treat bacterial infections with antibiotics, but for most viruses, we have either a vaccine or nothing. And a vaccine, wonderful as it is, doesn’t help you after you’re already infected.

The scientists, led by Thomas Geisbert at Boston University, used a relatively new genomics technique called RNA interference to defeat the virus. Here’s how it works.
First, a little background: the Ebola virus is made of RNA, just like the influenza virus. And just like influenza, Ebola has very few genes – only 8. One of its genes, called L protein, is responsible for copying the virus itself. Two others, called VP24 and VP35, interfere with the human immune response, making it difficult for our immune system to defeat the virus.

Geisbert and his colleagues (including scientists from Tekmira Pharmaceuticals and USAMRIID) designed and synthesized RNA sequences that would stick to these 3 genes like glue. How did they do that? We know the Ebola genome’s sequence – it was sequenced way back in 1993. And we know that RNA sticks to itself using the same rules that DNA uses. This knowledge allowed Geisbert and colleagues to design a total of 10 pieces of RNA (called “small interfering RNA” or siRNA) that they knew would stick to the 3 Ebola genes. They also took care to make sure that their sticky RNA would not stick to any human genes, which might be harmful. They packaged these RNAs for delivery by inserting them into nanoparticles that were only 81-85 nanometers across.
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Why Does the Moon Appear Larger on the Horizon?

Why does the Moon look so huge on the horizon?

If you’ve ever seen the Moon rising over the horizon, looking so fat and looming that you felt like you could fall right into it, then you’ve been a victim of the famous Moon Illusion. And it is an illusion, a pervasive and persuasive one.
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When the Moon is on the horizon, your brain thinks it’s far away, much farther than when it’s overhead. So the Ponzo Illusion kicks in: your brain sees the Moon as being huge, and it looks like you could fall into it. The Illusion works for the Sun, too. In fact, years ago I saw Orion rising over a parking lot, and it looked like it was spread across half the sky. It’s an incredibly powerful illusion.

Oddly enough, when it’s on the horizon, the Moon actually is farther away than when it’s overhead. Not by much, really, just a few thousand kilometers (compared to the Moon’s overall distance of about 400,000 kilometers).
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So the Moon Illusion is just that. It’s not the air acting like a lens, or foreground objects making it look big by comparison. It’s just the way we see the shape of the sky together with the well-known Ponzo Illusion.
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Science taking something we perceive as real, breaking it down, and showing it to be an interesting but decidedly unreal illusion? Well, that’s what science does! It helps us not only understand the world better, but it also makes the world cooler, too.

Trying to Find Pest Solutions While Hoping Evolution Doesn’t Exist Doesn’t Work

How To Make A Superweed

Melander wondered why some populations of scales were becoming able to resist pesticides. Could the sulfur-lime spray trigger a change in their biology, the way manual labor triggers the growth of callouses on our hands? Melander doubted it. After all, ten generations of scales lived and died between sprayings. The resistance must be hereditary, he reasoned. He sometimes would find families of scales still alive amidst a crowd of dead insects.

This was a radical idea at the time. Biologists had only recently rediscovered Mendel’s laws of heredity. They talked about genes being passed down from one generation to the next, yet they didn’t know what genes were made of yet. But they did recognize that genes could spontaneously change–mutate–and in so doing alter traits permanently.
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In the short term, Melander suggested that farmers switch to fuel oil to fight scales, but he warned that they would eventually become resistant to fuel oil as well. In fact, the best way to keep the scales from becoming entirely resistant to pesticides was, paradoxically, to do a bad job of applying those herbicides. By allowing some susceptible scales to survive, farmers would keep their susceptible genes in the scale population. “Thus we may make the strange assertion that the more faulty the spraying this year the easier it will be to control the scale the next year,” Melander predicted.
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What’s striking is how many different ways weeds have found to overcome the chemical. Scientists had thought that Roundup was invincible in part because the enzyme it attacks is pretty much the same in all plants. That uniformity suggests that plants can’t tolerate mutations to it; mutations must change its shape so that it doesn’t work and the plant dies. But it turns out that many populations of ryegrass and goosegrass have independently stumbled across one mutation that can change a single amino acid in the enzyme. The plant can still survive with this altered enzyme. And Roundup has a hard time attacking it thanks to its different shape.
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Another way weeds fight off Roundup is through sheer numbers. Earlier this year an international team of scientists reported their discovery of how Palmer amaranth resists glyphosate. The plants make the ordinary, vulnerable form of the enzyme. But the scientists discovered that they have many extra copies of the gene for the enzyme–up to 160 extra copies, in fact.
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What makes the evolution of Roundup resistance all the more dangerous is how it doesn’t respect species barriers. Scientists have found evidence that once one species evolves resistance, it can pass on those resistance genes to other species. They just interbreed, producing hybrids that can then breed with the vulnerable parent species.

Another great article from Carl Zimmer.

A single Liter of Seawater Can Hold More Than One Billion Microorganisms

Mat of microbes the size of Greece discovered on seafloor

mighty microbes, which constitute 50 to 90 percent of the oceans’ total biomass, according to newly released data.

These tiny creatures can join together to create some of the largest masses of life on the planet, and researchers working on the decade-long Census of Marine Life project found one such seafloor mat off the Pacific coast of South America that is roughly the size of Greece.

A single liter of seawater, once thought to contain about 100,000 microbes, can actually hold more than one billion microorganisms, the census scientists reported. But these small creatures don’t just live in the water column or on the seafloor. Large communities of microscopic animals have even been discovered more than one thousand meters beneath the seafloor. Some of these deep burrowers, such as loriciferans, are only a quarter of a millimeter long.

“Far from being a lifeless desert, the deep sea rivals such highly diverse ecosystems as tropical rainforests and coral reefs,”
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Microbes help to turn atmospheric carbon dioxide into usable carbon, completing about 95 percent of all respiration in the Earth’s oceans…

Why Planes Need to Avoid Fine Volcanic Ash

Volcanic ash: why it’s bad for planes

Aircraft avoid any airspace that has volcanic ash in it for a simple reason: the ash can wreck the function of propeller or jet aircraft, because it is so fine [less than 2mm in diameter, and some as fine as 6 microns] that it will invade the spaces between rotating machinery and jam it – the silica melts at about 1,100C and fuses on to the turbine blades and nozzle guide vanes (another part of the turbine assembly), which in modern aircraft operate at 1,400C.

That, in turn, can be catastrophic – as the crew of two aircraft, including a British Airways Boeing 747, discovered in 1982 when they flew through an ash cloud from the Galunggung volcano in Indonesia. On both planes, all four engines stopped; they dived from 36,000ft (11km) to 12,000ft before they could restart them and make emergency landings.
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The Icelandic plume has been thrown to between 6km and 11km into the atmosphere – exactly the height that aircraft would be flying.

Passengers on the BA flight that hit the cloud in 1982 said the engines looked unusually bright: soon after all four flamed out. “I don’t believe it – all four engines have failed!” said the flight engineer. The crew were prepared to ditch, and the captain told the passengers: “Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them under control. I trust you are not in too much distress.”

Luckily, three of the engines could be restarted. The plane landed safely, and nobody was injured.