This week we discover which gut bacteria can break down cholesterol naturally. We look at (or through) a window that blocks the heat but not the view. We investigate a binary star system that explodes into view once every 80 or so years. We expect it to explode in the next 5 months. Finally we marvel at a new photo of Sagittarius A* (the black hole at the center of the Milky Way).
Gut Bacteria breaking down Cholesterol
A team at the University of Groningen in the Netherlands has pinpointed a human gut bacteria that can convert cholesterol into a more harmless form that is not absorbed by the body. This may lead to new treatments for high cholesterol.
A 2020 study identified a bacterial enzyme called ismA that can convert cholesterol into coprostanol, a lipid that is excreted by the body. People whose gut bacteria made this enzyme had lower cholesterol levels than those that did not. The team has now determined exactly which bacteria produce this enzyme.
The team discovered that people with gut bacteria in the genus Oscillibacter had lower cholesterol levels. They then used a “protein language model”, a deep learning algorithm to search for genes similar to genes known to affect cholesterol metabolism. The model assessed the features of the gene and predicted how the protein encoded by the gene will fold into a 3D structure.
They found three species that have gene encoding proteins that are structurally similar to ismA and other enzymes involved in cholesterol metabolism. Lab experiments showed that the species can metabolize cholesterol.
This may lead to a more natural treatment for high cholesterol however the gut microbiome is complex. Care has to be taken that any new treatment does not have unwanted additional affects. For example a beneficial bacterial has been developed to treat Clostridium difficile, a common pathogen, however it kills off a lot of bacteria in the gut. This works for a one off treatment however might be problematic for an ongoing treatment such as one for high cholesterol. There is more work to do.
Window covering that blocks heat, not the view
A team at the University of Notre Dame has developed a new window covering that will block heat generating ultraviolet and infrared light whilst allowing visible light to enter a room. The covering works no matter the time of day or angle of the sun. Incorporating the covering onto existing windows in buildings and automobiles can reduce air conditioning costs by more than one third in hot climates.
Previous coverings were optimized for light entering at a 90 degree angle. At noon, the hottest time of the day, the sun’s rays enter at oblique angles. This significantly reduces the covering’s effectiveness.
The team fabricated a transparent window coating by stacking ultra thin layers of silica, alumina and titanium oxide on a glass base. Micrometer thick silicon polymer was added to enhance the structure’s cooling power by reflecting thermal radiation.
Additional optimization to the order of the layers ensured the coating would accommodate multiple angles of light. The team used a computer model to develop the optimum configuration of layers. This allowed the maximum transmission of visible light and reduced the passage of heat producing wavelengths. The resulting coating reduced the temperature by 5.4 to 7.2 degrees Celsius in a model room at all angles of light.
Massive Star Explosion coming soon
A once in a lifetime star explosion is expected sometime within the next 5 months and will be visible for a couple of days. The explosion occurred some 3,000 light years away (so 3,000 years ago) and appears to recur every 80 or so years.
A binary star system in the constellation Corona Borealis (Northern Crown) is not normally visible to the naked eye. However every 80 or so years the matter that is being ejected by one of the stars lands on the other star and heats up enough to kickstart a runaway thermonuclear reaction. This reaction is bright enough for us to see it as a star in the northern sky.
The binary star system is made up of a red giant star and a white dwarf star. A red giant is a star which has burnt through all its hydrogen and massively expanded. Our sun will do this over the next 5 billion years. A white dwarf is a star in a later stage of the star death cycle, the atmosphere has been blown away and only an incredibly dense core remains. The two stars are very different inside. The white dwarf orbits the red giant every 227 days.
The red giant emits matter which collects on the white dwarf. When that matter explodes, the temperature reaches between 100 and 200 million Celsius. The star system was first discovered in 1866 and then seen again in 1946. The next time we should be able to see the star system in our skies is sometime between now and September 2024.
Normal novas only explode once every 100,000 years. Recurring Novas explode more often. We know of 10 recurring novas in the Milky Way that repeat their explosions within a human lifetime. The gap between explosions varies along with the variations in the binary star systems.
Sagittarius A*
The black hole at the center of our galaxy is known as Sagittarius A* (pronounced Sagittarius A star) It weighs roughly 4.3 million suns. We took the first photo of the black hole in 2022. The black hole is totally black and the gravity is so strong it does not emit light (in truth we took a photo of the surroundings of the black hole).
There are powerful twisting magnetic fields surrounding black holes. The photo below captures the polarized light and matter surrounding Sagittarius A*. This is known as the accretion disk. Some of the material will fall into the black hole as it passes the event horizon, the final boundary between space and the black hole.
Only 2 black holes have been photographed. Sagittarius A* and the black hole at the center of galaxy M87 (it is 1,000 times bigger than our black hole). The photo was captured using the Event Horizon Telescope. This is a network of radio telescopes around the earth working together as a planet sized virtual telescope. More radio telescopes are being added to this network with the goal being real time video of black holes.
Solar Eclipse
For those who missed it here is a photo from NASA of the solar eclipse that passed over North America this week. It is a composite photo of many images (it is not an AI generated photo).
Paying it Forward
If you have a start-up or know of a start-up that has a product ready for market please let me know. I would be happy to have a look and feature the startup in this newsletter. Also if any startups need introductions please get in touch and I will help where I can.
If you have any questions or comments please comment below.
I would also appreciate it if you could forward this newsletter to anyone that you think might be interested.
Till next week.