The Risks of Scanning

The Risks of Scanning by Nayer Khazeni, M.D

When ordered by your doctor in the proper setting, any risks of CT scans are far outweighed by their potential benefits. They are one of modern medicine’s greatest diagnostic tools, used to examine any part of your body and, increasingly, to guide minimally invasive procedures previously performed with surgery. CT rapidly rotates X-ray beams around you, obtaining images from different angles that a powerful computer then compiles to build, slice by slice, highly detailed pictures of your insides.
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The impressive level of detail that CT provides can also cause confusion. In CTs of healthy adults, more than 90 percent of findings are “false positives.”
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Full-body CT scans cost $500 to $1,000. Insurance companies do not cover the cost, but may use any detected abnormality to raise your premiums or limit future coverage. There are no public health organizations that advocate the use of full body or cardiac CT scans in healthy adults, and the American College of Radiology and American Heart Association have released statements recommending against them.

Some Bacteria Might Fight Cancer

Cancer and the bacterial connection

today, some scientists think Coley had it right: Germs can teach our bodies how to fight back against tumors. Dr. John Timmerman, a cancer immunotherapy expert at UCLA’s Jonsson Cancer Center, says this revolution has produced “the most exciting sets of compounds in cancer immunolog
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The studies also imply that our cleaner, infection-free lifestyles may be contributing to the rise in certain cancers over the last 50 years, scientists say, because they make the immune system weaker or less mature. Germs cause disease but may also fortify the body, a notion summed up in a 2006 report by a team of Canadian researchers as “whatever does not kill me makes me stronger.”
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Other groups have been experimenting with injections of other types of heat-killed bacteria, including Myobacterium vaccae, a tuberculosis relative. In two studies in January’s European Journal of Cancer, researchers report that these bacteria may help fight certain lung and renal cancers.

The rich interplay of complex systems are often very difficult to grasp simply. I discusses this concept in the post on the excellent book, Parasite Rex.

Grand Challenges for Engineering

Here are the Grand Challenges for engineering as determined by a committee of the National Academy of Engineering:

* Make solar energy economical
* Provide energy from fusion
* Develop carbon sequestration methods
* Manage the nitrogen cycle
* Provide access to clean water
* Restore and improve urban infrastructure
* Advance health informatics
* Engineer better medicines
* Reverse-engineer the brain
* Prevent nuclear terror
* Secure cyberspace
* Enhance virtual reality
* Advance personalized learning
* Engineer the tools of scientific discovery

Committee members included: J. Craig Venter, President, The J. Craig Venter Institute; Dean Kamen, Founder and President, DEKA Research and Development Corp; Raymond Kurzweil, Chairman and Chief Executive Officer, Kurzweil Technologies, Inc and Larry Page, Co-Founder and President of Products, Google, Inc.

The web site (which by the way fails to even display the text on many pages without javascript – phb design) goes into more details on each challenge and will chronicle the ideas the public shares based on the challenges.

One Reason Bacteria Gain Tolerance So Quickly

I recently read Good Gems, Bad Germs as part of my effort to learn more about bacteria, viruses, how are bodies work, cells, microbiology etc.. It is a great book, I highly recommend it. Page 111:

In 1951 the husband-wife team of Joshua and Esther Lederberg, microbiologists at the University of Wisconsin, demonstrated that their elegantly simple proof that preexisting mutations, not gradual tolerance, accounted for the many instances of new drug resistance… This meant that every new antibiotic became a powerful new force for bacterial evolution, winnowing away every bacterium but the otherwise unremarkable one that could survive its effects. With its competition gone, that lucky mutant could populate, giving rise to a newly resistant colony overnight.

Since bacteria can grow remarkably quickly, eliminating all but a small number just means that the new population boom will come from those few, resistant, ancestors. But that is not the only reason bacteria are so challenging to fight. They have been around billions or years and have survived because they can adapt well. Bacteria, in fact, can get their genes from distantly related bacteria. So if one bacteria gains immunity another bacteria can get that immunity by getting genes from that other bacteria (seems like science fiction but it is actually science fact).

Science Explains: Flame Color

Have you ever wondered why some flames are yellow, while others are blue? Growing up, I was always told that it was a matter of temperature, that hot flames were blue and cooler flames were yellow. While there is a temperature difference, that difference is a “symptom” of what is going on, not the cause of the color difference.
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Does that mean that there is solid stuff inside the candle flame? Let’s find out. Light the candle and be sure it is steady and won’t fall over. Hold the bottom of the plate in the candle flame for a few seconds. When you remove the plate, it has turned black!!! Don’t worry. You have not ruined it. Let it cool for a minute. Remember, it is HOT! Once it has cooled, rub your finger over the black spot. The black rubs off.

Really Old Coral – Over 2,000 Years Old

photo of sea coral (leiopathes_glaberrima)

Worlds oldest animal aged to 4000 years

deep-sea gold corals (Geradia sp.) and black corals (Leiopathes glaberrima, pictured left) indicate these animals live between two and four millennia
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The new findings break all records previously claimed for marine invertebrates like the cold seep tubeworms (estimated 200 years old), quahog clams (estimated 400 years old), as well as the deep-sea wannabees Primnoa spp. and bamboo corals (45 – 300 years old). Given the new results, deep-sea animals can finally measure up to the longevity of the “Methuselah tree”, the Bristlecone Pine, estimated to be near 5000 years old.
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perhaps the most important thing to mention is that gold and black corals are colonial zoantharians. No single polyp is thought to be this old, just the skeletal axis.

How is Coral an animal?

Coral is an animal that belongs to the phylum cnidaria…
During the mating season coral polyp release eggs and sperm into the water (picture below) and when an egg and a sperm meet they form a larva known as a planula…
The baby coral looks like a little tiny jellyfish and it floats around in the water until it finds a hard place to attach to, usually a coral reef. Then it lands and starts to build itself a shell. It builds it by combining carbon dioxide (CO2) and calcium (Ca) in the water to make calcium carbonate (CaCO3) also known as limestone. This shell is shaped like a round vase and the coral polyp lives inside…

Parasitic Worms Reduce Hay Fever Symptoms

Parasitic worms reduce hay fever symptoms

Researchers are seeking to use the ability of the hookworm, Necator americanus, to suppress immune system responses that occur in conditions including Crohn’s disease, multiple sclerosis, asthma and other allergies. Recently-completed studies suggest giving worms to people with hay fever is safe, and potentially beneficial.
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Scientists have suggested a lack of such intestinal parasites has left those in the developed world more vulnerable to diseases caused an overactive immune system.

Parasite Rex is an excellent book exploring similar ideas and more on the interaction of parasites with hosts. And from Good Germs Bad Germs, page 100:

in 1999 the Dutch biologist Maria Yazdanbakhsh found that eliminating intestinal worms from infected children in African villages immediately predisposed them to allergies.”

Superconducting Surprise

Assistant Professor of Physics Eric Hudson transfers liquid helium to cool the scanning tunneling microscope

Research Finds Superconducting Surprise

Most superconductors only superconduct at temperatures near absolute zero, but about 20 years ago, it was discovered that some ceramics can superconduct at higher temperatures (but usually still below 100 Kelvin, or -173 Celsius). Such high-temperature superconductors are now beginning to be used for many applications, including cell-phone base stations and a demo magnetic-levitation train. But their potential applications could be much broader. “If you could make superconductors work at room temperature, then the applications are endless,” said Hudson.

Superconductors are superior to ordinary metal conductors such as copper because current doesn’t lose energy as wasteful heat as it flows through them, thus allowing larger current densities. Once a current is set in motion in a closed loop of superconducting material, it will flow forever.
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The new MIT study shows that scattering by impurities occurs in the pseudogap state as well as the superconducting state. That finding challenges the theory that the pseudogap is only a precursor state to the superconductive state, and offers evidence that the two states may coexist.

This method of comparing the pseudogap and superconducting state using STM could help physicists understand why certain materials are able to superconduct at such relatively high temperatures, said Hudson. “Trying to understand what the pseudogap state is is a major outstanding question,” he said.

Photo: Assistant Professor of Physics Eric Hudson transfers liquid helium to cool the scanning tunneling microscope he is using in his research on high-temperature superconductivity. Photo by Donna Coveney.

Dead Zones in the Ocean

Oceanic Dead Zones Off West Coast are the ‘New Normal’

Ever since it was first noticed by crab fishermen who hauled up hundreds of dead and dying crabs in 2002, the “dead zone” that popped up in the waters along the northwestern coastal shelf just off the coast of Oregon has claimed unknown millions of lives. This oxygen-depleted region has transformed formerly rich seafloor communities teeming with life into vast graveyards filled with the bodies of crabs, echinoderms, molluscs, sea worms and other creatures.
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a low-oxygen zone appears each spring off the coast of Louisiana due to fertilizers in farm runoff and sewage present in the Mississippi River. When the Mississippi flows into the sea, it creates a nutrient-rich area that triggers huge but short-lived algal blooms that soon die, sink to the seafloor and are decomposed by bacteria that produce toxic sulfide gases.
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the dead zone off the West Coast of North America has another cause: global warming. Here’s how it works: Winds cause the oceanic rivers of nutrients, such as the California Current in this case, to flow upwards from the deep, carrying nutrients and phyoplankton into the sunlight, which triggers the phytoplankton to reproduce, to “bloom”. This is the normal state of things, but since global warming has been causing land temperatures to increase, these winds have become stronger and more persistent. This is not normal because it prolongs the oceanic upwelling, producing a surplus of phytoplankton that isn’t consumed and subsequently dies, and sinks to the seafloor to decay. As the bacterial-mediated breakdown occurs, dissolved oxygen in the surrounding water is depleted to dangerously low levels

Polar Bears and Huskies

I posted about Polar Bear and Dogs previously. Now here is a video: