WHAT'S AT THE BOTTOM OF THE DEEPEST HOLE ON EARTH?
Remove this rusted metal cap and the world's deepest hole tunnels miles into the Earth. However, we know more about certain distant galaxies than we do about what lies miles beneath our very own feet. For that reason, Soviet scientists in the 1970s decided to probe deeper than humanity has ever done before. For the next 24 years, they drilled on and off into the Earth's crust.
The result was the Kola Super deep Borehole and a drill-depth of more than 7.5 miles (12 kilometers). To put that in perspective, Kola descends further than the deepest point of the ocean, which lies at nearly 6.8 miles (11 kilometers). The borehole is located on the Kola Peninsula of Russia.
So did we learn anything from these decades of labor? Thankfully, yes! Scientists found microscopic fossils of single-celled organisms at 4.3 miles (7 kilometers) down. And at nearly the same depth, they discovered water. They also found that the temperature at the bottom of the hole reached a blistering 356°F (180°C). Being too hot to continue, drilling officially halted in 1994. However, what's even more impressive is that scientists estimate that the distance to the center of the Earth is nearly 4,000 miles (6,400 kilometers). Turns out, 7.5 miles barely scratches the surface.
Drug Restores Brain Function and Memory in Early Alzheimer's Patients
A novel therapeutic approach for an existing drug reverses a condition in elderly patients who are at high risk for dementia due to Alzheimer's disease, researchers at Johns Hopkins University found.
The drug, commonly used to treat epilepsy, calms hyperactivity in the brain of patients with amnestic mild cognitive impairment (aMCI), a clinically recognized condition in which memory impairment is greater than expected for a person's age and which greatly increases risk for Alzheimer's dementia, according to the study published this week in Neuro Image : Clinical.
The findings validate the Johns Hopkins team's initial conclusions, published three years ago in the journal-- Neuron. They also closely match the results in animal studies performed by the team and scientists elsewhere. Next, neuroscientist Michela Gallagher, the lead investigator, hopes the therapy will be tested in a large-scale, longer-term clinical trial.
Hippocampal over-activity is well-documented in patients with aMCI and its occurrence predicts further cognitive decline and progression to Alzheimer's dementia, Gallagher said.
"What we've shown is that very low doses of the atypical antiepileptic levetiracetam reduce this over-activity," Gallagher said. "At the same time, it improves memory performance on a task that depends on the hippocampus."
The team studied 84 subjects; 17 of them were normal healthy participants and the rest had the symptoms of pre-dementia memory loss defined as aMCI. Everyone was over 55 years old, with an average age of about 70.
The subjects were given varying doses of the drug and also a placebo in a double-blind randomised trial. Researchers found low doses both improved memory performance and normalised the over-activity detected by functional magnetic resonance imaging that measures brain activity during a memory task. The ideal dosing found in this clinical study matched earlier preclinical studies in animal models.