Earth temperature percentiles for September 2014. Dark red patches were record warmest, while lighter red patches were warmer than average. Image courtesy of the NOAA.
The trend continues. The hottest September on record follows the hottest August on record, according to data from the Nation Oceanic and Atmospheric Association. 2014 continues apace as the hottest year ever.
An electron micrograph of an Ebola virus virion.
Ebola has been making lots of news this year, as the virus has popped up in several West African countries. We are in the midst of the largest and most widespread outbreak in history.
Fruit bats are the main carriers of the virus in nature. Initially, humans become infected with the ebola virus after contact with infected bats or any living or dead animals that have been infected by the bats. This contact is often thought to be from consumption of infected meat. After humans become infected, the disease spreads through contact with infected bodily fluids including sweat, saliva, urine and semen. Ebola is insidious, and in some cases can take up to 21 days after exposure before symptoms manifest. Symptoms include a sudden onset of flu-like fever, ache and fatigue followed by vomiting or diarrhea.
Sky News details why the virus is so deadly:
When ebola enters the body, it targets dendritic cells in the immune system. Normally, when a virus is detected, these cells tell other cells to produce antibodies. Ebola prevents that signal getting out. As far as the immune system knows, everything inside the body is fine. Left alone, ebola then begins replicating rapidly. It then spreads into the bloodstream, infecting the whole body. Cells start to break up and die, in huge numbers. That finally triggers the immune system, which kicks in – far too aggressively.
Ordinarily when you get sick, the body releases proteins called cytokines. Some of these cells tell your blood vessels to become more permeable. This is to let antibodies travel through the body more quickly to fight the disease. But once ebola has taken hold of your body, the immune system reacts much too aggressively – and launches a cytokine storm. This causes blood vessels to become far too permeable, and they leak. At the same time, the body’s blood clotting mechanisms also act abnormally. This causes internal and external bleeding and is why ebola is known as a haemorrhagic fever. It causes tissue damage and organ failure.
Though the disease is deadly, people do survive and countries can contain outbreaks. Survivors’ blood may contain antibodies that can be used to treat others suffering from the disease.
The Nobel prizes were awarded this week. Each year there are three science related awards in the fields of medicine, physics and chemistry.
In the field of medicine, the award went to John O´Keefe, May-Britt Moser and Edvard I. Moser for discovering the brain cells that make up our positioning system. In 1971 John O’Keefe discovered that when a rat was in a certain part of the room, one part of the hippocampus was always activated. When the rat was in other parts of a room there were different cells activated. He termed these cells “place cells” and determined that they formed a map. In 2005, the Mosers discovered what they called “grid cells”. These cells generated a coordinate system and aid in finding our way along paths. Read more about the physiology and medicine prize here.
This years physics medal went to the invention of LEDs and was awarded to Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura. The three researchers contributed to the development of LED technology, which is prevalent in today’s telephones, lamps, and computers. LED lights emit brighter light than incandescent lights and for longer periods of time. Read more about the award at Scientific American. The press release is here.
The chemistry prize was awarded to Eric Betzig, Stefan Hell, and William Moerner for developing super resolved fluorescence microscopy. Researchers thought they were limited by the limit of diffraction when it came to resolving images under a microscope. The three Nobel recipients have developed technology that helped overcome this limitation and resolve images into the nanometer scale. Stefan Hell developed a technique called stimulated emission depletion microscopy or STED. Bezig and Moerner, working separately, performed the groundwork for the development of single molecule microscopy. You can read the press release here, and a more detailed description of high resolution microscopy here.