Herein is the value of a thorough oral exam, which cannot be performed on an awake animal. Anesthetic dental procedures allow for complete oral examination and dental x-rays, which allows you to discover dental disease that is not visible to the naked eye.
This dog’s carnassial tooth (the large tooth to the right) and the molar (the smaller tooth behind it) look normal. There is no excessive gum recession, and the tartar has been cleaned off the tooth, leaving a pearly white surface. The first photo shows the length of the dental probe. While probing the large carnassial tooth, the probe barely slips underneath the gumline because the gum is firmly attached to the bone underneath the tooth, as it should be.
A gentle probe to the molar behind it, though? WTF did my probe go????? It fell into a bottomless black hole! This is what is called a periodontal pocket, which is where the gum’s attachment to the bone has been eaten away, and the bone is typically in a state of destruction as well due to infection. The carnassial tooth was not extracted, but the molar behind it was.
The picture in the lower right shows a small premolar tooth. Premolars have two roots, and the gap between the two roots is filled in with bone. However, when the bone is eaten away, the furcation (the split between the roots) can become visible. In this case I could not see the furcation because the gum still came up to the bottom of the tooth. But when I tapped that area with the probe, it went all the way through to the other side of the tooth, which is a grade III furcation exposure (out of 3) and an indication for extraction.
Dentistry has an endlessly steep learning curve to it but I am constantly finding new things to be interested in about it all the time. Even if your pet seems to have clean teeth, things like this can lurk beneath the surface!
All of our skin organs form from simple folds in skin tissue. Once this process was in place, it was modified to produce all kinds of skin organs — from a reptile’s scale to a bird’s feather to a mammal’s mammary glands.
Learn more tomorrow with Neil Shubin when Your Inner Fish continues tomorrow (4/16) on PBS at 10/9c.
Spark, Spark! The Chemistry of Fireworks
Ever wondered what causes those fancy fiery works of art shine so bright? The science of how fireworks operate is actually simple. And we’ll find out.
Pyrotechnics, especially fireworks, operate on a simple theory called combustion. Combustion involves the use of oxygen, that why you can’t light a fire in an airtight setup. It also involves the release of energy, in form of heat and/or light energy.
For a firework to burst into an array of spectacular colors, it must contain the following:
- Fuel. Must contain either charcoal or thermite alongside the common blackpowder.
- Oxidizing Agents. These produces the oxygen needed to burn the mixture. These are either nitrates, chlorates, or perchlorates.
- Reducing Agents. These react with the O2 released by the oxidizing agent/s to produce hot gases, and can also be used to control the speed of the reaction. Sulfur and charcoal are the most common reducing agents used.
- Metals. These also control the speed of reaction. Larger surface area = faster reaction rate.
- Coloring Agents. They give color to the firework. Strontium (Sr) produces red, Copper (Cu) produces blue, Barium (Ba) produces green, Sodium (Na) for yellow, Calcium (Ca) for orange, and Gold (Au) or Titanium (Ti) for an iron-ish color. These elements when heated, produces excess energy in form of light, and the higher the temperature, the shorter the wavelength.
- Binders. These hold the mixture in a paste-like texture. The most commonly used binder is dextrin, though parson is also used.
So, fireworks are actually maelstroms of excess heat energy released by different reactions occurring inside the canister. So as we welcome 2014, let us appreciate these brilliant works of both art and science. Cheers to a new year!
15 April 2014
Most people who catch a dose of the food poisoning bacteria Salmonella just suffer a nasty bout of diarrhoea. But if the bacteria spread through the body, which can occasionally happen in young children and the elderly, this ‘tummy bug’ can be life-threatening. Treatment with antibiotics often works, but sometimes the infection comes back with a vengeance when the drugs stop. To discover why, researchers are studying mice that suffer from Salmonella infections in the same way we do. They’ve found that the bacteria ‘hide out’ in special immune cells called dendritic cells – highlighted green in this image of an infected mouse’s lymph node – and slow down their growth. This enables them to lay low and resist antibiotic treatment, so they can grow again afterwards. Stimulating the immune system helps to flush out these sneaky bugs, which could be a new approach for treating severe infections in future.
Written by Kat Arney
Image courtesy of Wolf-Dietrich Hardt and colleagues
ETH, Zurich, Switzerland
Copyright held by original authors
Research published in PLOS Biology, February 2014
I admit it. I laughed too.
HEALTH TIP: when you’re about to sneeze be courteous and cover your mouth with the nearest anti-vaccination activist.