Blood clot by James Archer
A thrombus, or blood clot, is the final product of the blood coagulation step in hemostasis.
Blood clotting is an important mechanism to help the body repair injured blood vessels.
Blood consists of:
-red blood cells containing hemoglobin that carry oxygen to cells and remove carbon dioxide (the waste product of metabolism)
-white blood cells that fight infection
-platelets that are part of the clotting process of the body
-blood plasma, which contains fluid, chemicals and proteins that are important for bodily functions.
Complex mechanisms exist in the bloodstream to form clots where they are needed. If the lining of the blood vessels becomes damaged, platelets are recruited to the injured area to form an initial plug. These activated platelets release chemicals that start the clotting cascade, using a series of clotting factors produced by the body. Ultimately, fibrin is formed, the protein that crosslinks with itself to form a mesh that makes up the final blood clot.
Blood clots are healthy and lifesaving when they stop bleeding. However, blood clots can also form abnormally, causing a heart attack, stroke, or other serious medical problems.
Most heart attacks and strokes result from the sudden formation of a blood clot on a waxy cholesterol plaque inside an artery in the heart or brain. When the plaque ruptures suddenly, thrombogenic substances inside the plaque are exposed to blood, triggering the blood clotting process.
It might look like someone taking their life into their own hands, but thankfully this lake is the only place in the world where you can swim safely amongst millions of jellyfish.
In ‘Jellyfish Lake’ on the Pacific island of Palau, swimmers can take a dip surrounded by thousands of the normally harmful marine animals which have all lost their sting.
The lake was once connected to the Pacific Ocean, but when the sea level dropped, the jellyfish became isolated in the algae-rich lake and have not had to defend themselves from predators.
As a result, their population has thrived, and the eight million jellyfish now in the lake have all lost their sting.
Tourists can now swim alongside the jellyfish in the 12,000-year-old lake, one of around 200 saline marine lakes now identified worldwide.
I’ve swam there. It’s incredible.
Supernova remnant is a nebula left behind after a supernova, a spectacular explosion in which a star ejects most of its mass in a violently expanding cloud of debris. At the brightest phase of the explosion, the expanding cloud radiates as much energy in a single day as the Sun has done in the past three million years.
(Image credits: ESA/NASA/ESO/Rogelio Andreo)
The Space shuttle orbiter 101 Enterprise approaches riding atop its 747 carrier aircraft, arrives at the Redstone Arsenal airstrip near Marshall Space Flight Center (MSFC), Huntsville, Alabama, on March 13, 1978. It is to undergo ground vibration tests along with the external tank and solid rocket boosters, in preparation for Orbiter Flight Tests (OFT) in which its successor craft (Orbiter 102) will take several two-man crews into earth orbit.
Evaporating Blobs of the Carina Nebula
No, they are not alive — but they are dying. The unusual blobs found in the Carina nebula, some of which are seen floating on the upper half, might best be described as evaporating. Energetic light and winds from nearby stars are breaking apart the dark dust grains that make the iconic forms opaque. Ironically the blobs, otherwise known as dark molecular clouds, frequently create in their midst the very stars that later destroy them. The floating space mountains pictured above by the orbiting Hubble Space Telescope span a few light months. The Great Nebula in Carina itself spans about 30 light years, lies about 7,500 light years away, and can be seen with a small telescope toward the constellation of Keel (Carina).
Image Credit: ESA/Hubble, NASA