The existence of large numbers of molecules in winds powered by supermassive black holes at the centers of galaxies has puzzled astronomers since they were discovered more than a decade ago. Molecules trace the coldest parts of space, and black holes are the most energetic phenomena in the universe, so finding molecules in black hole winds was like discovering ice in a furnace.
Astronomers questioned how anything could survive the heat of the energetic outflows, but a new theory from researchers in Northwestern University’s Center for Interdisciplinary Research and Exploration in Astrophysics (CIERA) predicts that these molecules are not survivors at all, but brand-new molecules, born in the winds with unique properties that enable them to adapt to and thrive in the hostile environment.
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A stroke is just one example of a condition when communication between nerve cells breaks down. Micro-failures in brain functioning also occur in conditions such as depression and dementia. In most cases, the lost capacity will return after a while. However, consequential damage will often remain so that the functional capability can only be restored through lengthy treatment — if at all. For this reason, researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have been investigating what happens during such breakdown phases and looking at possible ways of preventing damage and speeding up the healing processes. Their findings have been recently published in the eminent journal Scientific Reports.
(Image caption: Nerve cell networks visualised using high-speed fluorescent microscopy and then reconstructed with the software developed by Wrosch and her team. Credit: FAU/Jana Wrosch)
The research team headed by Jana Wrosch of FAU’s Chair of Psychiatry and Psychotherapy found that significant alterations occurred in neural cells while the communication pathways were blocked. Neuron networks reconnect during such periods of inactivity and become hypersensitive. If we imagine that normal communication pathways are motorways, when they are blocked a form of traffic chaos occurs in the brain whereby information is re-routed in disorganised form along what can be called side streets and minor routes. Additional synapses are generated everywhere and begin operating. When the signal is reinstated, the previously coordinated information routes no longer exist and, as in the case of a child, the appropriate functions need to be learned from scratch. Since they are receiving no normal signals during the phase of brain malfunction, the nerve cells also become more sensitive in an attempt to find the missing input. Once the signals return, this means they may overreact.
Nerve cells flicker when stained
Visualising the microscopically minute connections between the nerve cells is a major technical challenge. The conventional microscopic techniques currently available, such as electron microscopy, always require preliminary treatment of the nerve cells that are to undergo examination. However, this causes the nerve cells to die, so that the alterations that occur in the cells cannot be observed. To get round this problem, Wrosch and her team have developed a high-speed microscopy process along with special statistical computer software that make it possible to visualise the communication networks of living neurons. First, a video of the cells is made whereby an image is taken every 36 milliseconds. A special dye is used to stain the cells to ensure that the individual cells flicker whenever they receive a signal. Subsequently, the software recognises these cells on the video images and detects the information pathways by which the signals are transmitted from cell to cell.
The nerve cells are then exposed to the pufferfish poison tetrodotoxin to simulate the blocking of communication channels that occurs in disorders. After inducing communication breakdown phases of varying lengths, the researchers remove the toxin from the cells and determine how the nerve cell networks have changed during exposure. ‘Thanks to this concept, we have been finally able to discover what happens when communication is blocked,’ explains Wrosch. ‘Now we can try to develop medications that will help prevent these damaging changes.’ In future projects, the research team plans to examine the exact mode of action of anti-depressants on nerve cell networks and intends to find new approaches to creating more effective drugs.
The Magnetospheric Multiscale mission, or MMS, has been studying the magnetic field on the side of Earth facing the sun, the day side – but now we’re focusing on something else. On February 9, MMS started the three-month-long process of shifting to a new orbit.
One key thing MMS studies is magnetic reconnection – a process that occurs when magnetic fields collide and re-align explosively into new positions. The new orbit will allow MMS to study reconnection on the night side of the Earth, farther from the sun.
Magnetic reconnection on the night side of Earth is thought to be responsible for causing the northern and southern lights.
To study the interesting regions of Earth’s magnetic field on the night side, the four MMS spacecraft are being boosted into an orbit that takes them farther from Earth than ever before. Once it reaches its final orbit, MMS will shatter its previous Guinness World Record for highest altitude fix of a GPS.
To save on fuel, the orbit is slowly adjusted over many weeks. The boost to take each spacecraft to its final orbit will happen during the first week of April.
On April 19, each spacecraft will be boosted again to raise its closest approach to Earth, called perigee. Without this step, the spacecraft would be way too close for comfort – and would actually reenter Earth’s atmosphere next winter!
The four MMS spacecraft usually fly really close together – only four miles between them – in a special pyramid formation called a tetrahedral, which allows us to examine the magnetic environment in three dimensions.
But during orbit adjustments, the pyramid shape is broken up to make sure the spacecraft have plenty of room to maneuver. Once MMS reaches its new orbit in May, the spacecraft will be realigned into their tetrahedral formation and ready to do more 3D magnetic science.
Learn more about MMS and find out what it’s like to fly a spacecraft.
How the Geneva Drive (the mechanical step that makes the second hand on a clock work by turning constant rotation into intermittent motion) works.
Now we know the (proposed) names of the four new elements, here’s an updated graphic with more information on each! High-res image/PDF: http://wp.me/p4aPLT-1Eg
Today is Copernicus’s 540th birthday. You may remember Copernicus as the man who said “Hey, what if the Earth went around the sun?” To which the Catholic Church replied “Hey, what if we set you on fire?”