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Science Square (Issue 105)
May 1, 2015

Natural Antifreeze from Ticks

Frostbite Protection in Mice Suggests an Antifreeze Glycoprotein
Heisig M. et al. PLOS ONE, February 2015.

Some animals such as ticks and fish have anti-freeze proteins that protect them from extreme cold conditions. Anti-freeze proteins typically prevent cold damage by limiting the formation of ice crystals that would otherwise lead to tissue damage. However, warm-blooded mammals, including humans, do not have such proteins and can suffer injuries from severe cold, such as frostbite. In a recent study, scientists tested whether the anti-freeze proteins of other species can protect mammals from such cold injuries. They genetically introduced an anti-freeze protein from the black-legged tick into a live mouse. When mice tails were exposed to cold for seven days, 60% of the transgenic mice showed no visible signs of frostbite, compared to only 11% of the controls. In addition, inflammation response from the immune systems of the transgenic mice was dramatically lower.  This study is the first to demonstrate a protein’s ability to boost frostbite resistance in an adult mammal. Although any potential human applications of anti-freeze proteins are far away, this study spotlights two future directions. First, anti-freeze proteins could potentially be utilized to extend the lifetime of organs prior to transplantation. Second, anti-freeze proteins may provide cellular protection for people with certain autoimmune diseases, such as scleroderma, that are characterized by cold sensitivity.

Smartphones as earthquake warning devices

Crowd-sourced earthquake early warning
Minson ES et al. Science Advances, April 2015.

The cellphones in our pockets function as cameras, calculators, flashlights – and now earthquake sensors. During an earthquake, even a few seconds can make a difference between life and death. Japan has the most advanced early warning system, which saved many lives during the 2011 Tohoku earthquake with a magnitude of 9.0. However, these systems are expensive and not practical at a personal level. A new study proposes that smartphones can be utilized to detect earthquakes via their GPS (Global Positioning System). Although GPS in smartphones use a relatively coarse method of positioning compared with many sensitive instruments, they can detect as little as six inches of displacement, which can be sufficient for earthquake detection. Scientists first tested the accuracy of smartphone GPS systems by shaking a phone and comparing the recorded displacements with a sensitive scientific instrument. After many analyses in different contexts, they concluded that smartphones could reliably detect earthquakes of a magnitude 7.0 and above. However, an obvious problem with this approach is that smartphones are always in motion as we walk, drive, or simply play with our phones; how can a smartphone differentiate a real earthquake from a routine motion? Scientists then came up with a solution called a “trigger” in which an earthquake alarm would only be activated if a smartphone and its four closest neighbors recorded the same amount of displacement. Experts are still skeptical about how well this system would work in a real-world situation. But, the benefit of crowd-sourcing earthquake detection is well recognized; all you need is a smartphone app.

Ocean acidification linked to the greatest extinction

Ocean acidification and the Permo-Triassic mass extinction.
Clarkson MO et al. Science, April 2015

A recent study suggests that ocean acidification caused by extreme volcanic activity triggered the greatest extinction of all time. This extinction event took place approximately 252 million years ago, and over the course of 60,000 years, it erased more than 90% of marine species and 60% of land animals. The researchers analyzed ancient rocks from the deserts of the United Arab Emirates, which were formed on the ocean floor about 250 million years ago. They specifically examined the ratios of boron and carbon isotopes. These chemical measurements revealed that oceans went from alkaline to highly acidic over the course of a few thousand years, which is very quick in geological terms. Scientists suggest that a huge pulse of volcanic eruptions discharged immense amounts of carbon dioxide into the atmosphere and acidified the oceans. This resulted in possibly fatal conditions for marine life; when combined with the destruction of food chains, most marine life went extinct. The amount of carbon added to the atmosphere during the mass extinction was predicted to be greater than today's fossil fuel reserves. However, alarmingly, the rate of carbon released at the time was very similar to modern emissions. Oceans today are rapidly acidifying due to increased CO2 emissions by human activities such as the burning of fossil fuels; the average pH has dropped by 0.1 units since the beginning of the Industrial Revolution. Oceanographers cautioned that a dramatic rise in the acidity levels of oceans affects all marine life, particularly shellfish fisheries around the world. We can only hope that the future does not resemble the past.