Zark's

Long Weekend Because the Earth is Slowing Down

The primary time and frequency standard for the United States, NIST-F1 Cesium Fountain Atomic Clock
Image Credit: NIST

Just in time for a long holiday weekend for the U.S., clocks will receive an extra second today (June 30).  The reason - "The solar day is gradually getting longer because Earth's rotation is slowing down ever so slightly," says Daniel MacMillan of NASA's Goddard Space Flight Center in Greenbelt, Md."

NASA Explains Why Clocks Will Get an Extra Second on June 30 tells that Earth's rotation is slowing down because of tidal forces between the Earth and the moon.  Every 100 years, the day becomes 1.4 milliseconds longer.  Over time, those milliseconds add up.  In fact, at the time of the dinosaurs, the day was about 23 hours long. 

Because the Earth is not a very reliable time keeper, scientists changed the definition of a second to a cesium standard, or atomic clock in 1967.  NIST-F1 picture above creates a cesium ball of atoms that is excited by a microwave signal.  A laser then measures the frequency of the photons produced by the cesium.  Since that is precisely known as 9,192,631,770 Hz, it permits the uncertainty of the clock to be less than 3x10^-16.  That means it will not change a second in 100 million years.  (Click on the NIST-F1 link for the complete description.)

 

 

Why Coal Stopped Forming

Mineral collection of Brigham Young University Department of Geology, Provo, Utah. Photograph by Andrew Silver.
Image Credit: USGS

The title isn't quite accurate.  Actually about 300 million years ago, the Earth's formation of coal slowed down substantially, not stopped.

A fascinating story, White Rot Fungi Slowed Coal Formation explains mushrooms changed a world. In Improving Biofuels, I explained that one of the obstacles to creating hydrocarbons from biomass is a polymer named lignin.  This provides strength and stiffness to a plant's stalk, but it binds tightly to the cellulose, which prevents efficent transformation into a biofuel. 

Enter in the mushroom, or more specifically, wood-decay fungus.  White-rot fungi break down the lignin in wood, but don't decompose the cellulose.  In particular, honey fungus is a mushroom that grows on wood and is responsible for the white-rot root disease of forests.

The Scientific American article tells that from genetic analysis of mushroom fungi, scientists have traced back the first ability to break down lignin to 300 million years ago.  Prior to that genetic change, wood did not rot, instead it simply sank into the soil, destined to become the coal seams that we exploit today.  But when the mushrooms developed the ability to digest wood, the raw material for coal was much reduced.

Scientists are still trying to determine how white-rot breaks down lignin.  That knowledge will help preserve wood products like your backyard fence, but more importantly, how to dissolve the lignin from biomass so that we can produce biofuels more efficiently.

 

FDA Approves First Weight Loss Drug in 13 Years

Runner in Georgia
Image Credit: CDC/ Amanda Mills

Mmm.  Instead of showing a negative image, I decided to show a positive image while writing about obesity. 

MedlinePlus explains that obesity is having too much body fat.  That is different from being overweight, or weighing too much, which includes muscle and bone. 

Generally obesity is the gradual accumulation of fat caused by eating more calories than you burn.  There is a high correlation between obesity and many diseases, including heart disease, stroke, arthritis, and some cancers.  The good news is that even losing 5 to 10 percent of your weight can significantly improve your health.

FDA approves Belviq to treat some overweight or obese adults tells that lorcaserin hydrochloride has been approved in coordination with a reduced calorie diet and increased exercise.  In addition, it is for individuals with a body mass index index greater than 30, or 27 if they have high blood pressure or diabetes.

There are some side effects - headache, dizziness, fatigue, nausea, dry mouth, and constipation.  The BBC adds that the drug has marginal success - perhaps 5 percent weight loss. 

Aspirin: Good or Bad?

Adding a chemical tag called an acetyl group (shaded yellow box, bottom) to a molecule derived from willow bark (salicylate, top) makes the molecule less acidic (and easier on the lining of the digestive tract), but still effective at relieving pain.

Image Credit: National Institute of General Medical Sciences

Mmm.  Do you remember that terribly boring college chemistry experiment where you supposedly produce aspirin?  I never sampled my aspirin, but I had a roommate that ingested a lot of chemicals.  But that is a different story...

For several years now, there have been several groups that advocate adults taking an aspirin a day to decrease the probability of a heart attack or stroke.  Although not a doc, I haven't agreed with this prescription, and Daily Aspirin: Work the Risk? tells cautions that aspirin can lead to major bleeds.  Further, that although the data suggests aspirin may help prevent a second heart attack, the data is fuzzy on whether it reduces the chances of the first one. 

But the real surprise today was, Aspirin may not prevent blood clots that cause heart attacks and strokes among diabetics.  New data reveals many type-2 diabetes patients are aspirin-resistant.  Hence, the standard low-dosage aspirin may provide no benefit at all to someone with type-2 diabetes.  Science Daily tells that elevated urine levels of 11-dehydro-thromboxane beta-2, or 11DhTx2, indicate resistance to aspirin. Curiously, these are not associated with insulin levels, although they may be an indicator of kidney disease in diabetes.

Especially surprising from the study is that 53 percent of the type-2 patients were aspirin-resistant.  Clearly though, anyone with type-2 diabetes should consult a doc about the relevance of the study to their particular regimen.

 

 

Sea Level Rising Faster on U.S. East Coast

Areas that would be under water should a sea-level rise of four meters occur.
Image credit: Weiss and Overpeck, The University of Arizona.

As I have blogged in the past, one of the most sensitive regions to sea level change is Chesapeake Bay.  The U.S. Navy has replaced its waterfront at Norfolk with a double decker pier, the top deck originally 21 feet above water level. 

Global Climate Change Briefing at William and Mary tells that 125,000 years ago, sea levels were 12 to 18 feet higher than today.  Scientists don't know how long the glaciers will last, but the thermal expansion of water alone will result in a one to two foot sea level rise by the end of the century.

Sea Levels Rising Fast on U.S. East Coast tells that region is rising three to four times faster than the rest of the world.  Wind and ocean currents cause the ocean's water to pile up in some areas more than others.  The trade winds push the Pacific water so that the sea level at Ecuador is one-half meter lower than Indonesia.  So that explains why some regions are experiencing greater sea level changes. 

Sea Level Rise Accelerating in U.S. Atlantic Coast explains that USGS researchers studied sea level changes from 1990 and discovered that sea levels in the 600 mile stretch from Cap Hatteras, NC, to Boston, MA, have increased 2 - 3.7 mm per year.  USGS warns that cities like Norfolk, New York, and Boston will suffer increasingly greater flooding as the waters continue to rise.

The Gulf of Mexico Dead Zone

Satellite image of the Gulf of Mexico and coastline
Image Credit: USGS

Artfully captured as early Americana by Mark Twain, the largest river system in North America, the Mississippi, begins in northern Minnesota and winds 2,530 miles to empty into the Gulf of Mexico.  After contributions from 31 states, it discharges, on average, 593,000 cubic feet of water per second into the gulf.  That is 4,436,000 gallons per second, or as WolframAlpha helpfully adds, 6.7 times the volume of an Olympic-sized swimming pool every second. Lest we become pompous, this is only about 8 percent of the discharge of the Amazon River.

On the long journey from St. Paul Minnesota, the river accumulates chemicals and other things that are not water.  Particularly harmful are nitrogen and phosphorus that are primarily agricultural runoff, although there are other sources.  These two nutrients result in algae growth.  The real problem is not while they are alive and producing oxygen, but instead, when they die, drop to the bottom of the gulf and decompose.  The massive decomposition robs sealife of oxygen, creating a dead zone.

Dead Zone: The Source of the Gulf of Mexico's Hypoxia tells that in 2002, the dead zone was 8400 square miles.  Most recently the dead zone has been about the size of Connecticut and Rhode Island combined - 6700 sequare miles.  This year though, there has been a drought in the midwest, and the Mississippi has dumped a little more than 1/2 the normal amount of nutrients into the gulf.  Hopefully that will reduce the dead zone to only the size of Rhode Island, sparing Gulf of Mexico aquatic life and the fishing industries.

If you are interested, USGS has produced a new online research tool for assessments of streams and rivers.

 

 

Making the Universe Obey Theorems

The diagram at left shows the changes in the rate of expansion since the universe's birth 15 billion years ago.  Astronomers theorize that the faster expansion rate is due to a mysterious, dark force that is pulling galaxies apart.
Image and text courtesy of NASA/STScI/Ann Feild.

The universe is strange, and I"m not even considering your local Star Wars bar scene.  One of the strangest phenomena is that the universe is expanding.  What is curious is that the distances between the many galaxies is increasing, but the galaxies themselves are not getting larger.  That is pretty strange isn't, it?  Everything is moving away from each other, in all directions, but nothing is getting larger.

NASA tells us that the expansion rate is 73.8 kilometers per second per megaparsec. This means for every 3.26 million light years a galaxy is from Earth, it is traveling 73.8 km/sec faster away from us.

The Friedmann-Lemaître-Robertson-Walker equation, describes the expansion of the universe.  It relates three constansts - the Hubble expansion, the curvature of space, and the density of energy in the universe.  But we need something that we have never seen, to make the theory work - dark energy.  There is not enough visible energy to make the equation work with the rate of expansion and space curvature we have measured.

Remember the units of the expansion?  km/sec.  That means the expansion is accelerating, it is not the result of the Big Bang, but some mysterious energy is pushing everything apart.   Further, because the expansion is the same in all directions, dark energy, which we can neither see, nor measure, must be uniform throughout the universe.

To help explain the mystery, Dark Energy Mapping Space Mission Get Final Approval tells that the European Space Agency has approved a new science telescope with the intent of studying the universe's expansion.  NASA will provide some funding, but the heavy investment will be provided by the international community.

 

NASA Unfurls A New Telescope

Artist's Depiction of NuSTAR
Image Credit: NASA/JPL/Caltech

The full name is nuclear spectroscopic telescope array (NuSTAR).  As illustrated in the graphic, the mast is 33 feet long and it allows the observation of x-rays.

Regular 2012 Hurricane Season Expected

This photo of Hurricane Frances was taken by Astronaut Mike Fincke aboard the International Space Station as he flew 230 miles above the storm at about 10 a.m. EDT Friday, Aug. 27, 2004.
Image Credit: NASA

Never mind that Wednesday evening, there was a trough of low pressure in the southeastern Gulf of Mexico that had a 30 percent chance of forming a tropical cyclone.

From my recent course on meteorology, I learned that hurricanes and tornadoes are very different.  Tornadoes require wind shear in order to form, and wind shear is death to a hurricane.  Tornadoes do not mind land, whereas traveling over land is also death to a hurricane. 

Another bit of trivia, which I learned from Tom Wolfe's The Right Stuff, test-pilots and would-be astronauts woudl invariably describe a flight in which a wing or engine came off as reg-U-larr, with the accent on the last syllable. 

NOAA predicts a near-normal 2012 Atlantic hurricane season predicts this will be a reg-U-larr seaaon with nine to fifteen named storms, and one to three major hurricanes.  The prediction explains that conditions are looking a little unfavorable for tropical cyclones this year.  There is strong wind shear and also cooler water temperatures in the eastern Atlantic which is the hatching ground for hurricanes.  Also, La Nina may be dissipating and transition into El Nino, which produces less favorable conditions for hurricanes.

On the negative side - if a hurricane does form and make it across the Atlantic, the water temperatures in the Gulf of Mexico and Carribean are warmer than usual, which provides fuel for hurricanes to grow large.  

One sobering thought - August will be the 20th anniversary of Hurricane Andrew, which made landfall at Homestead, Florida as a Category 5 hurricane.  It circled back into the Gulf of Mexico and made landfall again, this time at Morgan City Louisiana as a Category 3 hurricane.

Despite Media Impressions, No Increase in Flesh-Eating Bacteria

Image of Streptococcus, a type (genus) of spherical bacteria that can colonize the throat and back of the mouth.
Image Credit: Tina Carvalho, University of Hawaii at Manoa

Georgia flesh-eating bacteria victim's condition upgraded reminds us of the horrific disease contracted by Aimee Copeland.  The 24-year old college student has endured multiple amputations in the fight to save her from the bacteria. 

The CDC explains that the flesh-eating disease is more accurately named necrotizing fasciitis.  It can be caused by more than one type of bacteria - such as A strep), Klebsiella, Clostridium, E. coli, Staphylococcus aureus, and Aeromonas hydrophila.

Generally the skin is protection against the bacteria, but when they enter through a deep puncture wound, there are rare 'perfect storm' conditions that result in necrotizing fasciitis.  The name fasciitis describes the layers of a membrane, fascia, which lay beneath the skin and surrounds muscles, nerves, fat, and blood vessels.  The bacteria infect these membranes and sometimes the tissue next to the fascia. Necrotizing means, 'causing the death of tissue.'

The CDC tracks incidences of necrotizing fasciitis and there are typically 650-800 cases of necrotizing fasciitis in the U.S. each year, so it is a rare, but deadly infection.  The CDC reports that despite the publicity, the number of cases do not appear to be increasing.