Monday, July 21, 2014

Sandstone Arch Formation

"The fantastical arch shapes of sandstone formations have long been thought to be sculpted by wind and rain. But a team of researchers has now found that the shapes are inherent to the rock itself.
'Erosion gets [excess] material out, but doesn’t make the shape,' says Jiri Bruthans, a hydrogeologist at Charles University in Prague, who led the research. Rather, erosion is merely a 'tool' that works in combination with more fundamental factors embedded in the rock.
These factors are stress fields created by the weight of overlying rock. Under low stress, Bruthans says, sandstone erodes easily. But as stress mounts — as parts of a cliff or pillar are eroded away, for example — the sand grains on the surface of the remaining rock lock together and become more resistant to further erosion." - Richard A. Lovett, July 20, 2014, Sandstone arches form under their own stress, Nature International Weekly Journal of Science

Wednesday, July 16, 2014

Marijuana Abusers Less Responsive to Dopamine

Marijuana Leaf, SEM - JA5445
With the legalization of marijuana becoming increasingly prevalent (but no less controversial) in states like Colorado and Washington, research pertaining to the drug's chemical components and their long term effects on the human body remain scarce.  The challenge of studying the affects of marijuana can become quite difficult, as it involves approval from numerous federal agencies that become speed-bumps along the road to research.

However researchers from the National Institute on Drug Abuse in Bethesda, M.D., were able to take a closer look at brain imaging scans of marijuana abusers to see how the dopamine system (the brain's "pleasure chemical") was affected by excessive, long-term use of the drug.  Their findings showed that while both the control group and marijuana abusers produced similar levels of dopamine, marijuana abusers exhibited almost none of the physical responses such as increased blood pressure and heart rate, restlessness, or feeling high.

Cocaine and alcohol abuse has been known to cause a decrease in dopamine production in the brain, though the same cannot be said for marijuana.  This latest research suggests that marijuana abusers can still produce normal amounts of dopamine, but may experience less reward or pleasure from their normal activities, fueling further dependence on the drug that can damage the brain's reward circuitry.

Learn more


Monday, July 14, 2014

Oxygen and Evolution

Tiger Iron BU7005
"One of the biggest riddles in Earth's history is why animals did not evolve after a spike in oxygen levels approximately 2.3 billion years ago. Instead, despite what scientists had thought was a period of relatively high oxygen, the evolution of life on Earth stalled for what is dubbed the ‘boring billion’." - Jane Qiu, July 14, 2014, Oxygen fluctuations stalled life on Earth, Nature International Weekly Journal of Science

To read more click here.


Wednesday, July 9, 2014

Samples of Smallpox Found in Old NIH Lab

Smallpox Virus, TEM - BV2384
An old laboratory on the National Institutes of Health (NIH) campus in Bethesda, MD., was in the process of being cleaned out in preparation for moving the lab to the main campus.  During that time, scientists uncovered six vials of the smallpox virus in a storage room, prompting an immediate response by the Centers for Disease Control and Prevention (CDC) to transport the frozen samples to a secure facility.  Once there, the CDC will test the virus to see if it is still viable before destroying it.  There was no evidence of the samples being breached or lab workers being exposed to infection.

Smallpox is caused by the airborne variola virus, and results in flu-like symptoms which eventually develop into lesions appearing on the skin, which rapidly enlarge and rupture.  It is estimated that smallpox was responsible for 300-500 million deaths in the 20th century, until a vaccine was discovered and the disease eradicated in 1977.  Since then, only two facilities in the world are allowed to keep samples of the virus under tight security.

Learn more.


Monday, July 7, 2014

Evolution: Continuing Discoveries

Peking Man BD8800
"A trio of anthropologists has decided it's time to rewrite the story of human evolution.
That narrative has always been a work in progress, because almost every time scientists dig up a new fossil bone or a stone tool, it adds a new twist to the story. Discoveries lead to new arguments over the details of how we became who we are.
But anthropologists generally agree on this much: A little more than 2 million years ago in Africa, the human lineage emerged. Smithsonian anthropologist Rick Potts says the conventional wisdom is that much of Africa changed about then from forest to dry savanna. Our ape-like ancestors had to adapt or die, leave the forest and embrace the savanna — and in doing so, they evolved into something more like us." - Christopher Joyce, Dance Of Human Evolution Was Herky-Jerky, Fossils Suggest, NPR, July 4, 2014
To read more click here.


Wednesday, July 2, 2014

Battling the Ebola Outbreak

Ebola virus, molecular model - SP4493
The World Health Organization is attempting to contain an outbreak of Ebola which is "out of control" in regions of west Africa.  The outbreak, which experts believe may have started in February in southeast Guinea, has killed 468 of its 763 infected hosts.  The virus has since spread to neighboring parts of Liberia and Sierra Leone, mostly due to the high volume of commercial and social activity across the border.  WHO has begun gathering health officials from 11 countries in the region in an attempt to better educate the public about the virus and contain the outbreak as much as possible.

Ebola hemorrhagic fever (EHF) is a disease caused by the Ebola virus after close contact with contaminated blood or body fluids.  Patients develop a fever, sore throat, muscle pains, nausea, vomiting, diarrhea, and decreased liver and kidney function.  Eventually patients can develop severe internal bleeding, with an estimated 90% mortality rate.  There is no known cure or vaccine available to combat the virus, and the current situation in west Africa is seen as the largest outbreak in recorded history.

Learn more.


Wednesday, June 25, 2014

How Does Stress Affect Our Arteries?

Most people are aware that long term stress can have negative affects on the cardiovascular system, and increase your risk of heart attacks or stroke.  New research from Harvard Medical School has revealed some of the physiological changes taking place in our blood when exposed to chronic stress, and its link to atherosclerosis. 
Pressure Gauge in Heart - BM1944

Researchers found that mice exposed to constant stress had higher levels of monocytes and neutrophils circulating through their blood.  The accumulation of these white bloods cells are often found in fatty plaques that have been lodged in the walls of blood vessels.  Researchers then performed another experiment where they blocked bone marrow protein receptors responsible for stimulating the production of these immune cells.  They found that mice with reduced levels of active immune cells developed less plaque in their arteries.

Stress stimulates the body to prepare for oncoming danger, and the release of white blood cells will help the body heal injuries or combat infection.  However with chronic stress caused by work, money, or relationships, there aren't any infections or wounds to heal, leaving immune cells to continue circulating through the blood.  Researchers hope that a new approach to combat or monitor atherosclerosis can utilize white blood cell counts and regulate its stress-induced production.

Learn more.


Thursday, June 19, 2014

Whooping Cough Epidemic in California

NBC News reports on Whooping Cough Epidemic:
Bordetella pertussis, SEM
The number of whooping cough cases in California has officially reached epidemic proportions, the California Department of Public Health reported.
Whooping cough, known to doctors as pertussis, has experienced a resurgence this year with more than 3,400 new cases reported between Jan. 1 and June 10, according a statement released by the department.
Bleeding in eye from whooping cough
The department said whooping cough is cyclical, peaking every three to five years. The last big spike in cases was in 2010.

Los Angeles County has experienced about 350 new cases so far this year with Long Beach being hit especially hard. The city has seen more than 90 new infections, making up nearly 20 cases per 100,000 people.Read More...


Celiac Disease and the Rise of Gluten-free Diets

Gluten Free Groceries - BT2485
The gluten-free diet has been gaining increased popularity for its purported health benefits, though the truth behind its emergence can be attributed to the rise of celiac disease among the general population.  Celiac disease occurs in individuals with a genetic predisposition, and is an autoimmune disorder which attacks the lining of the small intestine when in the presence of the gluten protein.  Gluten is found in wheat, barley, rye, and other grains, and is commonly used as an additive in various foods and drinks.
Normal & Abnormal Jejunum (Celiac Disease) - BW5565

A celiac patient's intestinal lining can degrade overtime, limiting their ability to absorb nutrients and leading to other health problems such as osteoporosis, fatigue, anemia, or infertility.  This differs from an individual suffering from gluten sensitivity, a condition in which the digestive system has difficulty metabolizing gluten, resulting in short-term gastrointestinal symptoms and discomfort.  As a result, celiac patients must restrict their diet to meats, fruits, vegetables, and other gluten-free grains and starch such as rice, corn, and potatoes, while avoiding most processed foods containing gluten.

The sudden popularity of gluten-free diets seems to correspond with an increase in celiac disease diagnoses in the United States.  Though celiac disease only affects an estimated 1% of the population, those numbers are four times higher than they were in the 1950's. 

Monday, June 16, 2014

A Faster Way to Find the Origin of Malaria

The New York Times Writes:
By using a DNA “bar code” of 23 short snips from the genes of parasites that cause malaria, scientists can now often quickly determine where they originated, British researchers report.
The information could be useful in fighting local outbreaks, which may be caused by parasites from other parts of the world. And it should be possible to make a test kit that will get that information from a spot of dried blood in two hours — far less time than is needed to sequence a whole genome.  More...