Home is Where the Microbes Are

A person’s home is their castle and they populate it with their own subjects – millions and millions of bacteria.

When we move from one location to another we take all of our bacteria with us and “colonize” the space around us within a matter of hours. These “bacterial signatures” are unique.

Mouth microbes Credit Martin Oeggerli, with support from School of Life Sciences, FHNW

Microbiome studies could serve as a forensic tool. In the future scientists could look at bacterial colonies to identify the last person to come into contact with the victim of a crime and estimated when the contact happened.

Microbes on small intestines Credit: Stephanie Schuller

The human gut teems with bacteria, many of their species still unknown. They help us digest food and absorb nutrients, and they play a part in protecting our intestinal walls. Gut bacteria may also help regulate weight and ward off autoimmune diseases.

Chain of streptococcus in a lab sample. Credit: Photo by Martin Oeggerli, with support from School of Life Sciences, FHNW
Colored scanning electron micrograph of microbes in human gut Photo by Martin Oeggerli

What are “superbugs” ? Any bacteria that cannot be treated by two or more antibiotics is being called a superbug. The CDC claims the single leading factor for the increase in superbugs is the misuse of antibiotics. Most people who get a C. diff (Clostridium difficile) infection are getting medical care.

SEM by David Phillips of Clostridium Difficile

MRSA (Staphylococcus aureus) is carried by around 30 per cent of the population without causing any symptoms. However, in vulnerable people, such as those that have recently had surgery, it can cause wound infections, pneumonia and blood poisoning. MRSA cannot be treated with penicillin.

Staphylococcus aureus MRSA bacteria, computer artwork by Alfred Pasieka/Science Photo Library

Doctors sometimes recommend beneficial bacteria, also known as probiotics, for patients suffering from GI illnesses such as colitis and Crohn’s disease. However, these over-the-counter probiotic supplements may contain varying amounts of bacteria, and may include cells that are no longer viable. Furthermore, these probiotics have no protective coating, so they can be damaged by acid in the stomach before reaching the intestines.

An MIT team has come up with a method of coating these beneficial bacteria with layer-by-layer layers of polysaccharides or sugars. The thin, gel-like coating protects the bacteria cells from acid in the stomach, as well as bile salts. Once the cells reach the intestines, they settle in and begin replicating, creating a whole new microbiome.

MIT coated probiotic bacteria Credit: Second Bay Studios

 

 

How to Picture a Black Hole

“How exactly do you capture the image of a spinning, giant black abyss? You don’t,” “You take a picture of its shadow” said Dimitrious Psaltis, Professor of Astronomy and Physics at the University of Arizona. Psaltis is a key member of the Event Horizon Telescope.

Early images were shown in 2015 by The Laser Interferometer Gravitational-Wave Observatory (Ligo) detected gravitational waves radiating from two black holes that crashed together about 1.3 billion years ago. The Ligo team thinks they have detected ‘primordial’ black holes, which were formed soon after the big bang.

The image above is a simulation of The Laser Interferometer Gravitational-Wave Observatory (Ligo) showing gravitational waves, which are considered ripples in the fabric of space time.
The image above is a simulation of The Laser Interferometer Gravitational-Wave Observatory (Ligo) showing gravitational waves, which are considered ripples in the fabric of space time.

The Event Horizon Telescope, named after the point of no return in a black hole, is a network of telescopes around the Earth hoping to see what has been until now unseeable: an exquisitely small, dark circle of nothing, a tiny shadow in the glow of radiation at the center of the Milky Way galaxy. It is there that astronomers think lurks a super massive black hole, a trap door into which the equivalent of four million suns has evidently disappeared.

LMT Large Millimeter Telescope in Mexico at 15, 092 feet
LMT Large Millimeter Telescope in Mexico at 15, 092 feet – part of the Event Horizon Telescope network

The Event Horizon Telescope team hopes to obtain the first-ever picture of an astrophysical black hole in 2017. Next spring those telescopes will turn the Earth into one giant eye when they all point to Sagittarius A*—the black hole at the center of the galaxy first forecast by Albert Einstein and his theory of general relativity, and since then the subject of study by countless theoretical physicists, among them the famous cosmic detective Stephen Hawking. Sagittarius A* is 26,000 light-years away.

 X-ray of Sagittarius A*: NASA/UMass/D.Wang et al., IR: NASA/STScI
X-ray of Sagittarius A* showing the area where the Black Hole is present.  Credit: NASA/UMass/D.Wang et al., IR: NASA/STScI

The 2017 picture of the Sagittarius A* Black Hole might look more like this:

False-color image showing light radiating by gas swirling around and into a black hole. The dark region in the middle is the black hole shawdow. Credit: Dexter, J., Agol, E., Fragile, P. C., McKinney, J. C., 2010, The Astrophysical Journal, 717, 1092.
False-color image showing light radiating by gas swirling around and into a black hole. The dark region in the middle is the black hole shadow. Credit: Dexter, J., Agol, E., Fragile, P. C., McKinney, J. C., 2010, The Astrophysical Journal, 717, 1092.

We will have to wait and see….

A Chemistry Revolution

Model of NaCl3  Credit:  Artem Organov and Weiwei Zhang
Model of NaCl3 Credit: Artem Organov and Weiwei Zhang

We all know NaCl is table salt. Ever heard of NaCl3?  Or Na3Cl?

Table salt, also known as sodium chloride or NaCl, is one of the best-known and most studied chemical compounds.  Its chemical composition is simple – one sodium atom (Na) and one chlorine atom (Cl). Classical chemistry says atoms try to fulfill the octet rule — elements gain or lose electrons to attain an electron configuration of the nearest noble gas, with complete outer electron shells that make them very stable.  Sodium has one extra electron and chlorine is missing one, so sodium donates one electron to chlorine, leaving both atoms with an outer shell containing eight electrons and forming a strong ionic bond.

Artem R. Oganov, professor of theoretical crystallography in the Department of Geosciences at Stony Brook University, is causing quite a stir challenging the foundation of chemistry. Oganov’s lab has produced novel compounds by applying high pressure.  They heated samples of table salt under pressure with lasers and found new compounds of Na and Cl which came as a surprise. The new compounds are stable and, once made, remain indefinitely.

Model of NaCl3  Credit:  Artem R. Oganov & Weiwei Zhang
Model of NaCl3 Credit: Artem R. Oganov & Weiwei Zhang

Among the compounds Oganov and his team created are two-dimensional metals, where electricity is conducted along the layers of the structure. “One of these materials – Na3Cl – has a fascinating structure,” Oganov says. “It is comprised of layers of NaCl and layers of pure sodium. The NaCl layers act as insulators; the pure sodium layers conduct electricity”.

The experiments with table salt might only be the beginning of the discovery of completely new compounds.  Understanding and predicting high-pressure compounds can lead to new theories with applications for atrophysics and planetary sciences, where high pressure abounds.

Superstring Theory and ToE

Conceptual computer artwork by Alfred Pasieka/Science Photo Library

String theory attempts to combine two different theories – Quantum Theory and General Relativity – to create one ultimate theory of the universe.

Quantum Mechanics is a mathematical machine that predicts the behaviors of microscopic particles.

General Relativity was proposed by Einstein. It is the combination of space and time into what Einstein called spacetime. The theory states that rather than matter moving through a passive space-time continuum, that the presence of matter should distort space-time. Spacetime can be warped by forces from massive bodies such as planets.

String Theory postulates that subatomic particles such as quarks and electrons are not points of energy or matter, but are one-dimensional strings. String theory, if true, proves that everything in the universe is actually made up of tiny strings that are constantly vibrating or oscillating. The vibration of the string determines the charge and mass of the greater particle.

ToE

Superstring Theories take this idea and build the entire universe from the bottom up. And yes, it’s as challenging a task as it sounds. That’s why we speak of String Theories in the plural, because there are several different String Theories that attempt to make it all work. Oh, and at least 10 dimensions are called for, too, just for all the math involved. Physicists propose that any dimensions beyond time and visible space are folded up and out of sight.

As you probably guessed, Superstring Theory is still developing, meaning that physicists continue to work out kinks in the individual String Theories. Eventually they’re aiming to fulfill Einstein’s unrealized goal of unifying General Relativity with Quantum Theory. That’s why string theory also is sometimes called a Theory of Everything (ToE), because it could serve someday as a foundation for all future scientific discovery and innovation.

Computer art of Superstrings by Mehau Kulyk/Science Photo Library
Computer art of Superstrings by Mehau Kulyk/Science Photo Library