A set of Japanese iron armor, Kofun period, 5th century AD.
Currently on display at the Tokyo National Museum.
kazuaki horitomo’s tattooed cats.
Molecular body guards for neurons
In the brain, patterns of neural activity are perfectly balanced. The interplay between activating and inhibitory neurotransmitters ensures that the level of activity stays within the physiological range. During an epileptic attack excitation gains the upper hand resulting in the death of neurons. Researchers of the Bonn University Medical School have now discovered a key player in a signal transduction cascade, which protects neurons from hyperexcitation-induced cell death. These results open a new direction for the development of novel therapy options. The results are now published in “The Journal of Neuroscience“.
Pathophysiological activity often triggers neuronal cell death. This can for example be observed after an epileptic insult. The cause for this hyperexcitation is excessive release of the signaling molecule glutamate. “This neurotransmitter can switch on signaling cascades that act neurotoxic”, says Prof. Dr. Schoch McGovern of the Institute of Neuropathology and the Department of Epileptology at the University Clinic Bonn. However, neurons try to protect themselves and prevent the damaging hyperexcitation.
The molecular nature of these “body guards” is so far unresolved. Accumulating evidence shows transcription factors to play an essential role in the processes by which neurons protect themselves. These factors switch on certain genes, which then via signal transduction cascades result in the production of neuroprotective substances. These in turn counteract the damaging glutamate-induced hyperexcitability.
Increased neuronal cell death in the absence of Syt10
The team of Prof. Dr. Schoch McGovern could now show that the protein Synaptotagmin 10 (Syt10) is an integral part of this protective shield. If rats for example experience an epileptic seizure, the amount of Syt10 in the hippocampal formation of the brain strongly increases. The researchers used neurons from mice, in which the Syt10 gene had been ablated, and stimulated them with a glutamate like substance. This treatment resulted in substantial neuronal death.
NPAS4 modulates the production of protective factors
The research team discovered, which transcription factor activates the gene for Syt10 in response to pathophysiological neuronal activity. This essential member of the neuronal body guard is called NPAS4. The researchers cultured rodent neurons and added several transcription factors. NPAS4 activated the Syt10 gene and required Syt10 to exert its neuroprotective function. “NPAS4 triggers a signaling cascade that results in the production of neuroprotective factors”, says Prof. Dr. Schoch McGovern.
Search for novel therapy approaches
The molecular identity of the neuroprotective substances is still unknown. “A potential candidate, the insulin-like growth factor IGF-1, was not able to reverse the increased neuronal cell death in the absence of Syt10”, reports the neurobiologist. The next step therefore is to test other substances. Once the identity of the neuroprotective body guards is revealed, novel avenues for therapy development open up, for example for stroke and epilepsy patients. “The goal would be to administer these protective substances from the outside in order to prevent neuronal cell death in the brain”, says Prof. Dr. Albert Becker, a medical doctor, who was part of the study. However, there is still a long road ahead.
Outubro 2020
Viagem pelas imagens.
A Whole New Jupiter: First Science Results from NASA’s Juno Mission
Early science results from NASA’s Juno mission to Jupiter portray the largest planet in our solar system as a complex, gigantic, turbulent world, with Earth-sized polar cyclones, plunging storm systems that travel deep into the heart of the gas giant, and a mammoth, lumpy magnetic field that may indicate it was generated closer to the planet’s surface than previously thought.
“We are excited to share these early discoveries, which help us better understand what makes Jupiter so fascinating,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. “It was a long trip to get to Jupiter, but these first results already demonstrate it was well worth the journey.”
Juno launched on Aug. 5, 2011, entering Jupiter’s orbit on July 4, 2016. The findings from the first data-collection pass, which flew within about 2,600 miles (4,200 kilometers) of Jupiter’s swirling cloud tops on Aug. 27, are being published this week in two papers in the journal Science, as well as 44 papers in Geophysical Research Letters.
“We knew, going in, that Jupiter would throw us some curves,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio. “But now that we are here we are finding that Jupiter can throw the heat, as well as knuckleballs and sliders. There is so much going on here that we didn’t expect that we have had to take a step back and begin to rethink of this as a whole new Jupiter.”
Among the findings that challenge assumptions are those provided by Juno’s imager, JunoCam. The images show both of Jupiter’s poles are covered in Earth-sized swirling storms that are densely clustered and rubbing together.
“We’re puzzled as to how they could be formed, how stable the configuration is, and why Jupiter’s north pole doesn’t look like the south pole,” said Bolton. “We’re questioning whether this is a dynamic system, and are we seeing just one stage, and over the next year, we’re going to watch it disappear, or is this a stable configuration and these storms are circulating around one another?”
Another surprise comes from Juno’s Microwave Radiometer (MWR), which samples the thermal microwave radiation from Jupiter’s atmosphere, from the top of the ammonia clouds to deep within its atmosphere. The MWR data indicates that Jupiter’s iconic belts and zones are mysterious, with the belt near the equator penetrating all the way down, while the belts and zones at other latitudes seem to evolve to other structures.
The data suggest the ammonia is quite variable and continues to increase as far down as we can see with MWR, which is a few hundred miles or kilometers.
Prior to the Juno mission, it was known that Jupiter had the most intense magnetic field in the solar system. Measurements of the massive planet’s magnetosphere, from Juno’s magnetometer investigation (MAG), indicate that Jupiter’s magnetic field is even stronger than models expected, and more irregular in shape. MAG data indicates the magnetic field greatly exceeded expectations at 7.766 Gauss, about 10 times stronger than the strongest magnetic field found on Earth.
“Juno is giving us a view of the magnetic field close to Jupiter that we’ve never had before,” said Jack Connerney, Juno deputy principal investigator and the lead for the mission’s magnetic field investigation at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
“Already we see that the magnetic field looks lumpy: it is stronger in some places and weaker in others. This uneven distribution suggests that the field might be generated by dynamo action closer to the surface, above the layer of metallic hydrogen. Every flyby we execute gets us closer to determining where and how Jupiter’s dynamo works.”
Juno also is designed to study the polar magnetosphere and the origin of Jupiter’s powerful auroras – its northern and southern lights.
These auroral emissions are caused by particles that pick up energy, slamming into atmospheric molecules. Juno’s initial observations indicate that the process seems to work differently at Jupiter than at Earth.
Juno is in a polar orbit around Jupiter, and the majority of each orbit is spent well away from the gas giant. But, once every 53 days, its trajectory approaches Jupiter from above its north pole, where it begins a two-hour transit (from pole to pole) flying north to south with its eight science instruments collecting data and its JunoCam public outreach camera snapping pictures. The download of six megabytes of data collected during the transit can take 1.5 days.
“Every 53 days, we go screaming by Jupiter, get doused by a fire hose of Jovian science, and there is always something new,” said Bolton. “On our next flyby on July 11, we will fly directly over one of the most iconic features in the entire solar system – one that every school kid knows – Jupiter’s Great Red Spot. If anybody is going to get to the bottom of what is going on below those mammoth swirling crimson cloud tops, it’s Juno and her cloud-piercing science instruments.”
NASA’s Jet Propulsion Laboratory in Pasadena, California, manages the Juno mission for NASA. The principal investigator is Scott Bolton of the Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate. Lockheed Martin Space Systems, in Denver, built the spacecraft.
IMAGE 1….This image shows Jupiter’s south pole, as seen by NASA’s Juno spacecraft from an altitude of 32,000 miles (52,000 kilometers). The oval features are cyclones, up to 600 miles (1,000 kilometers) in diameter. Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection. JunoCam’s raw images are available at www.missionjuno.swri.edu/junocam for the public to peruse and process into image products
IMAGE 2….NASA’s Juno spacecraft carries an instrument called the Microwave Radiometer, which examines Jupiter’s atmosphere beneath the planet’s cloud tops. This image shows the instrument’s view of the outer part of Jupiter’s atmosphere. Before Juno began using this instrument, scientists expected the atmosphere to be uniform at depths greater than 60 miles (100 kilometers). But with the Microwave Radiometer, scientists have discovered that the atmosphere has variations down to at least 220 miles (350 kilometers), as deep as the instrument can see. In the cut-out image to the right, orange signifies high ammonia abundance and blue signifies low ammonia abundance. Jupiter appears to have a band around its equator high in ammonia abundance, with a column shown in orange. This is contrary to scientists’ expectations that ammonia would be uniformly mixed.
IMAGE 3….The complexity and richness of Jupiter’s “southern lights” (also known as auroras) are on display in this animation of false-color maps from NASA’s Juno spacecraft. Auroras result when energetic electrons from the magnetosphere crash into the molecular hydrogen in the Jovian upper atmosphere. The data for this animation were obtained by Juno’s Ultraviolet Spectrograph. The images are centered on the south pole and extend to latitudes of 50 degrees south. Each frame of the animation includes data from 30 consecutive Juno spins (about 15 minutes), just after the spacecraft’s fifth close approach to Jupiter on February 2, 2017. The eight frames of the animation cover the period from 13:40 to 15:40 UTC at Juno. During that time, the spacecraft was receding from 35,000 miles to 153,900 miles (56,300 kilometers to 247,600 kilometers) above the aurora; this large change in distance accounts for the increasing fuzziness of the features. Jupiter’s prime meridian is toward the bottom, and longitudes increase counterclockwise from there. The sun was located near the bottom at the start of the animation, but was off to the right by the end of the two-hour period. The red coloring of some of the features indicates that those emissions came from deeper in Jupiter’s atmosphere; green and white indicate emissions from higher up in the atmosphere.
IMAGE 4….As NASA’s Juno spacecraft flew through the narrow gap between Jupiter’s radiation belts and the planet during its first science flyby, Perijove 1, on August 27, 2016, the Stellar Reference Unit (SRU-1) star camera collected the first image of Jupiter’s ring taken from the inside looking out. The bright bands in the center of the image are the main ring of Jupiter’s ring system. While taking the ring image, the SRU was viewing the constellation Orion. The bright star above the main ring is Betelgeuse, and Orion’s belt can be seen in the lower right. Juno’s Radiation Monitoring Investigation actively retrieves and analyzes the noise signatures from penetrating radiation in the images of the spacecraft’s star cameras and science instruments at Jupiter.
IMAGE 5….This sequence of enhanced-color images shows how quickly the viewing geometry changes for NASA’s Juno spacecraft as it swoops by Jupiter. The images were obtained by JunoCam. Once every 53 days the Juno spacecraft swings close to Jupiter, speeding over its clouds. In just two hours, the spacecraft travels from a perch over Jupiter’s north pole through its closest approach (perijove), then passes over the south pole on its way back out. This sequence shows 14 enhanced-color images. The first image on the left shows the entire half-lit globe of Jupiter, with the north pole approximately in the center. As the spacecraft gets closer to Jupiter, the horizon moves in and the range of visible latitudes shrinks. The third and fourth images in this sequence show the north polar region rotating away from our view while a band of wavy clouds at northern mid-latitudes comes into view. By the fifth image of the sequence the band of turbulent clouds is nicely centered in the image. The seventh and eighth images were taken just before the spacecraft was at its closest point to Jupiter, near Jupiter’s equator. Even though these two pictures were taken just four minutes apart, the view is changing quickly. As the spacecraft crossed into the southern hemisphere, the bright “south tropical zone” dominates the ninth, 10th and 11th images. The white ovals in a feature nicknamed Jupiter’s “String of Pearls” are visible in the 12th and 13th images. In the 14th image Juno views Jupiter’s south poles.
IMAGE 6….Waves of clouds at 37.8 degrees latitude dominate this three-dimensional Jovian cloudscape, courtesy of NASA’s Juno spacecraft. JunoCam obtained this enhanced-color picture on May 19, 2017, at 5:50 UTC from an altitude of 5,500 miles (8,900 kilometers). Details as small as 4 miles (6 kilometers) across can be identified in this image. The small bright high clouds are about 16 miles (25 kilometers) across and in some areas appear to form “squall lines” (a narrow band of high winds and storms associated with a cold front). On Jupiter, clouds this high are almost certainly composed of water and/or ammonia ice.
IMAGE 7….Small bright clouds dot Jupiter’s entire south tropical zone in this image acquired by JunoCam on NASA’s Juno spacecraft on May 19, 2017, at an altitude of 7,990 miles (12,858 kilometers). Although the bright clouds appear tiny in this vast Jovian cloudscape, they actually are cloud towers roughly 30 miles (50 kilometers) wide and 30 miles (50 kilometers) high that cast shadows on the clouds below. On Jupiter, clouds this high are almost certainly composed of water and/or ammonia ice, and they may be sources of lightning. This is the first time so many cloud towers have been visible, possibly because the late-afternoon lighting is particularly good at this geometry.
Noren - Tedomari Tsubame Niigata ken
Carbon is the backbone of life on Earth. We are made of carbon, we eat carbon and our civilizations are built on carbon. We need carbon, but that need is also entwined with one of the most serious problems facing us today: global climate change.
Forged in the heart of aging stars, carbon is the fourth most abundant element in the Universe. Most of Earth’s carbon – about 65,500 billion metric tons – is stored in rocks. The rest is in the ocean, atmosphere, plants, soil and fossil fuels.
Over the long term, the carbon cycle seems to maintain a balance that prevents all of Earth’s carbon from entering the atmosphere, or from being stored entirely in rocks. This balance helps keep Earth’s temperature relatively stable, like a thermostat.
Today, changes in the carbon cycle are happening because of people. We disrupt the cycle by burning fossil fuels and clearing land. Our Orbiting Carbon Observatory-2 (OCO-2) satellite is providing our first detailed, global measurements of CO2 in the atmosphere at the Earth’s surface. OCO-2 recently released its first full year of data, critical to analyzing the annual CO2 concentrations in the atmosphere.
The above animation shows carbon dioxide released from two different sources: fires and massive urban centers known as megacities. The animation covers a five day period in June 2006. The model is based on real emission data and is then set to run so that scientists can observe how greenhouse gas behaves once it has been emitted.
All of this extra carbon needs to go somewhere. So far, land plants and the ocean have taken up about 55 percent of the extra carbon people have put into the atmosphere while about 45 percent has stayed in the atmosphere. The below animation shows the average 12-month cycle of all plant life on Earth (on land and in the ocean). Eventually, the land and oceans will take up most of the extra carbon dioxide, but as much as 20 percent may remain in the atmosphere for many thousands of years.
Excess carbon in the atmosphere warms the planet and helps plants on land grow more. Excess carbon in the ocean makes the water more acidic, putting marine life in danger. Forest and other land ecosystems are also changing in response to a warmer world. Some ecosystems – such as thawing permafrost in the Arctic and fire-prone forests – could begin emitting more carbon than they currently absorb.
To learn more about NASA’s efforts to better understand the carbon and climate challenge, visit: http://www.nasa.gov/carbonclimate/.
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Do not go where the path may lead, go instead where there is no path and leave a trail. —Ralph Waldo Emerson
Meet the real women behind Hidden Figures.
Before electronic computers were common, NASA hired mathematicians like Katherine Johnson to do the computing. Even after NASA began using IBM computers to plan its missions, Astronaut John Glenn trusted Johnson’s abilities so much that he personally requested she recheck the computer calculations that helped him become the first American to orbit the Earth.
Johnson is one of the women whose work inspired the film Hidden Figures — the true story of three African American mathematicians who helped NASA launch the first Americans into space.
Feeling inspired? See how math might figure into your life. Uncover more about Katherine Johnson →