Under The Microscope: Velcro

Originally posted here: https://www.mcgill.ca/oss/article/under-microscope-velcro

Just like Vivaldi was inspired by nature to compose his Four Seasons concertos, the inventor of Velcro was also inspired by nature. Specifically, by burrs.

Swiss engineer George de Mestral first conceptualized Velcro in 1941 after examining the burrs that stuck to his clothes, hair and dog’s fur, something we now call biomimicry- taking inspiration from nature to innovate human design. He sought to mimic the hook-and-loop interaction with woven materials but was not taken seriously by those in the weaving industry. It wasn’t until Mestral turned to the newly invented synthetic fabric nylon and discovered how to mechanize Velcro’s creation (this took about 10 years), that his design began to spread throughout Europe.

It was marketed as a “zipperless zipper” but failed to gain mainstream popularity due to its less than ideal appearance. NASA’s use of Velcro in space suit designs prompted skiers to begin to utilize it, followed by Scuba divers and children’s clothing makers.

A slight aside- it turns out that NASA research or adoption is responsible for many of the innovations we use on a daily basis! Quite a few major technologies, like enriched baby food, cordless vacuums, LEDs and firefighter equipment were developed thanks to NASA. Read more about that here- https://spinoff.nasa.gov/Spinoff2008/tech_benefits.html

Today Velcro is used everywhere from in shoes to the International Space Station. It’s so common that I’m willing to bet there’s some within a few metres of you at this very moment. There a few reasons it is so popular as a fastener: It is usable thousands of times (tens of thousands if it’s made of stronger materials like Teflon), it’s cheap to manufacture, its resistant to degradation in wet conditions (although it will absorb water and grow mold) and maybe most importantly, it’s really strong! Velcro (the company) provides weight ratings up to 120 kg for some of its products.

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Under The Microscope: Rose Petals

Originally posted here: https://www.mcgill.ca/oss/article/history/under-microscope-rose-petals

Nowadays roses are mostly used for Bachelorette ceremonies and hipster lattes, but once upon a time roses, and their fruit, rose hips, were widely used as medicines.
Diarrhodon is the name given to herbal treatments containing roses, and there are lots of them, said to treat everything from liver problems to heart problems to digestion issues. Traditional Chinese medicine made use of the China rose for regulating menstruation, pain relief, thyroid problems and diarrhea.
Did any of the rose-based traditional therapies work? Well, at least one could have. As rose-hips are quite high in vitamin C, they would likely have done wonders for sailors afflicted with scurvy.
Today we mostly keep our rose-based products for use in cosmetics, and a few specialty food products like rose hip jam, rose water or syrup that is common in many Indian desserts, or rose flavouring for ice cream, liquor or hipster lattes.
Even though the petals in these photos have been dried for more than 5 years, they still retain a fair amount of pollen, seen as yellow specs on their surface.

Under the Microscope: Eyelashes

Originally posted here: https://mcgill.ca/oss/article/health/under-microscope-eyelashes

Eyelashes exist to keep dust and debris and bugs from entering our eyes, but in our modern day, they have come to be objects of beauty, enhancement and envy. While the Hadza people of Tanzania famously trim their eyelashes for beauty purposes, for most of us, long eyelashes have come to be an object of desire.
Most mammals have eyelashes (and a few birds too!) but they can be troublesome for humans, dogs and horses. There are quite a few conditions that can affect the eyelashes, so I will only name the most interesting ones.
Distichia involves eyelashes growing from parts of the eyelids they are not supposed to (in dogs this includes eyelashes growing underneath the eye since dogs do not have bottom lashes like humans!).
Trichiasis is the leading cause of infectious blindness in the world, and occurs when eyelashes grow towards the cornea, rubbing it and causing infections. This condition is especially common in certain dog breeds, although it can usually be managed through regular trimmings.
Madarosis is characterized by the loss of eyelashes or brows and can be caused by infections like leprosy or HIV, chemo drugs, autoimmune conditions like lupus, or a zinc deficiency.
Of course, you may be unhappy with your eyelashes, although there is nothing medically wrong with them. In that case, you have got some options available to you. There are the fairly common false eyelashes and eyelash extensions, but there is also the semi-permanent option of a lash dip. This procedure will run you upwards of $100, and involved applying a black gel, and sometimes silk extensions, to your lashes that sets and stays for about a month.
If these temporary solutions are not right for you, there is always eyelash transplants. For this, doctors take about 60 follicles of hair from your head and transplant them into your eyelash area. It is done as an outpatient procedure, and only takes 2-3 hours, although it will cost you upwards of $3000. Because these hairs will be head hair, not eyelashes, they will not engage in the normal 7-8 week grow-then-fallout cycle of eyelashes, so you will have to trim and curl them to keep them looking good.
There is an option if you would rather try to grow your own lashes thicker. Bimatoprost (sold under the names Lumigan and Latisse) was originally developed to treat high pressure in the eye, but patients using it reported their eyelashes growing thicker and longer. It is used as an eyedrop that is applied to the base of the lash area, and seems to work quite well, although some patients report the skin around their lashes darkening after use.

Under the Microscope: Graphite

Originally posted here: https://www.mcgill.ca/oss/article/technology/under-microscope-graphite

Pencils do not contain any lead, and they never did! The mistake in terminology can be traced back to the ancient Romans who drew lines on papyrus using pieces of actual lead, all the while not realizing it was incredibly toxic. Considering its toxicity, it’s really good that pencils never did contain lead. Could you imagine how much a child could ingest while chewing on their pencil?
So, what is the dark stuff inside pencils if not lead? It’s actually a mixture of graphite and clay. Graphite is literally named for its ability to leave marks on paper. It comes from the ancient Greek word graphein, meaning to draw.
If you’re ever especially stressed during an exam, you could always try squeezing your pencil tip. Under enough pressure, and at high enough a temperature, graphite turns into diamond, and I expect if you manage to manually make a diamond, you won’t mind a bad exam grade as much.
But besides allowing students to take exams and artists to draw, graphite serves an important role in batteries, particularly in lithium-ion batteries, due to its high conductivity.

Under the Microscope: Blood

Originally published here: https://mcgill.ca/oss/article/health/under-microscope-blood

Human blood contains many different components, from white blood cells to platelets, but the most abundant component by far are red blood cells.
More properly known as erythrocytes, red blood cells make up 70% of an adult human’s cells by count. They serve an integral purpose: transporting oxygen from the lungs to all other parts of the body and returning carbon dioxide to the lungs to be exhaled. To accomplish this, they have a few unique features.
In mammals, while developing red blood cells contain a nucleus and other organelles, before they mature fully, they extrude, or push out, these organelles. Having no nucleus, red blood cells are unable to create proteins or divide, but can they can store hemoglobin, the iron-containing molecule that binds oxygen and carbon dioxide. Each red blood cell can hold approximately 270 million hemoglobin molecules, each of which can bind 4 oxygen molecules. In total, your red blood cells hold about 2.5 grams of iron.
Red blood cells are shaped kind of like donuts that didn’t quite get their hole formed. They’re biconcave discs, a shape that allows them to squeeze through small capillaries. This also provides a high surface area to volume ratio, allowing gases to diffuse effectively in and out of them.
An adult human body produces around 2.4 million red blood cells every second, mostly within the bone marrow. A red blood cell will stay in circulation for 100-120 days, making a full circuit of the body ever 60 seconds. They transport inhaled oxygen to cells and return carbon dioxide to the lungs to be exhaled.
After this period is up, the membrane of the red blood cell undergoes a change that allows it to be recognized by a type of white blood cell called a macrophage, which breaks it down. Many of the components, including iron, are recycled and used to make more red blood cells. The main non-recyclable component is broken down into bilirubin, which is excreted in urine and bile. Although, if too much bilirubin is produced, it’s yellow colour can cause discoloration of the skin, as seen in jaundice.
Carbon monoxide has a 250 times greater binding affinity for hemoglobin than oxygen, meaning that if any carbon monoxide is present, it will bind to hemoglobin instead of oxygen. This is why carbon monoxide is such a danger, it reduces our bodies ability to get oxygen to our cells. This is also why many smokers are short of breath, as the carbon monoxide they inhale while smoking is out-competing oxygen for hemoglobin’s binding sites. In heavy smokers, up to 20% of oxygen binding sites may be blocked with carbon monoxide.
Because it is colourless and odourless, often times carbon monoxide’s effects aren’t noticed until they become really severe. To avoid a scary situation, every home should be equipped with a carbon monoxide detector.

Under the Microscope: Leopard Gecko Skin (McGill OSS)

Originally posted here: https://www.mcgill.ca/oss/article/general-science/under-microscope-leopard-gecko-skin

Leopard geckos (Eublepharis macularius) are a popular pet in many countries. They’re fairly easy to take care of, small, rarely bite, (and when they do it’s pretty painless) and can live up to 25 years! 

This lizard is named for its resemblance to the large cat, although not all leopard geckos feature the familiar black spots on yellow skin. Variations ranging from stripes instead of spots to albino, to a spot-less body and spotted tail are all possible, although leopard spots are the norm.

Leopard geckos get their colouring from special pigment-containing cells called chromatophores in their skin. Chromatophores are found in reptiles, fish, crustaceans and cephalopods, whereas birds and mammals instead have chromatocytes.

There are a few different types of chromatophores that can be categorized according to what pigments they contain. Ones containing yellow are named xanthophores, while those containing red or orange are called erythrophores. Melanophores contain a dark brown pigment while cyanophores contain, you guessed it, cyan pigments.

There are even chromatophores which make an animal appear iridescent called iridophores or leucophores. Some animals that use these include chameleons and squids. Some squids can change their colour by migrating different types of chromatophores to different locations on their body. The relative concentration of each type of chromatophore will determine the overall colour of the skin. 

About once a month (more often when younger) leopard geckos will shed their skin. They shed to allow themselves to keep growing, and after the skin is removed, they eat it! There are two theories as to why they consume the skin. It may be that they are attempting to hide signs that they have been in an area, or it may be that they are recapturing the vitamins and minerals (especially calcium) that the skin is full of. 

The skin that was placed under the microscope to generate this image was taken from an all yellow part of the shed skin of my 14-year-old leopard gecko, Geico, but nonetheless, a few melanophores are visible as dark dots within the cells.

Under the Microscope: Pollen

Originally published here: https://www.mcgill.ca/oss/article/environment/under-microscope-pollen

Grains of pollen actually produce the male gametes (sperm cells) of flowering plants. They become dehydrated to better allow themselves to be carried on by wind, water and animals to other plants where they land in the gynoecium, the innermost part of a flower that contains the ovaries. After rehydrating itself, a pollen grain forms a pollen tube, through which it transfers sperm cells into the ovaries of the flower, completing the pollination process.

How much pollen plants produce is influenced by how well fed a flower is. Excess carbon dioxide in the air is causing plants to produce more pollen, and warmer, wetter winters are allowing plants to begin producing pollen earlier. This is especially bad news for those of us with pollen allergies.

Seasonal allergies were first reported around the time of the industrial revolution. Although we’re not certain why they sprang up then, one theory is that the rapid urbanization and increase in human greenhouse gas emissions triggered their appearance.

Even now, pollen allergies are on the rise in urban centres. As the temperature increases, due to our elevated emissions, allergenic species are able to migrate into areas they previously couldn’t thrive in. This results in new allergies as well as worsening of previously existing ones.

Pollen counts are raised by windy and dry conditions and lowered by wet and cooler ones, so staying indoors on the hottest of spring days is a good idea. You might also want to consider what you can do to mitigate climate change. After all, the climate is unequivocally, undeniably changing. And not for the better.

Under The Microscope: Sea Salt VS Table Salt

Originally posted here https://www.mcgill.ca/oss/article/did-you-know-nutrition/under-microscope-sea-salt-vs-table-salt

Photos 1 and 2 show sea salt, while photo 3 shows table salt.
While they may taste different to the discerning chef and their crystals may look different under the microscope, table salt and sea salt are both essentially just sodium chloride. While sea salt does contain some other minerals, like calcium chloride or potassium sulphate, it is still made up of 90% or more sodium chloride.
Both sodium and chloride ions have important functions. Sodium regulates blood pressure and plays a role in transmitting messages between nerves and muscles while chloride is a component of hydrochloric acid needed for digestion.
The job of maintaining the right concentration of minerals in the blood falls to the kidneys. If blood levels of sodium chloride rise from the ingestion of too much salt, the kidneys will excrete less water in order to dilute the blood and maintain the proper salt concentration. This, however, has the effect of increasing blood volume which can lead to increased blood pressure and swelling in tissues as water leaks out of the bloodstream.
Thirst often accompanies a large intake of salt because water will also be drawn out of cells to help maintain the right concentration of salt in the bloodstream. This is why eating salty foods can lead to both thirst and dehydration! And it makes no difference whether it is table, sea, iodized or Himalayan salt.
The current recommendation is that sodium intake bekept under 2300 mg a day (that is 6000 mg of sodium chloride or roughly one teaspoon) although there is some controversy about whether people with normal blood pressure have to restrict salt intake. Some studies have actually shown that people who consume less than 3000 mg of sodium per day are at greater risk for heart disease than people with an intake of 4000-5000 mg. Most of the salt in the diet comes from consuming processed foods rather than the salt shaker. A single slice of pizza can contain as much as 1000 mg of sodium.

Under The Microscope: Paramecium

Originally posted here https://www.mcgill.ca/oss/article/did-you-know-environment/under-microscope-paramecium

Paramecium aresingle-celled organisms that belong to the Ciliophora phylum. Members of this group are characterized by having cilia, or little hair-like structures covering their surface.
Once called “slipper animalcules” due to their oblong shape, Paramecium livein a variety of watery environments, both fresh and salt, although they are most abundant in stagnant bodies of water. They eat other microorganisms like bacteria or algae by sweeping them towards their cell mouths (cytostomes) where they’re absorbed and digested.
These cilia, however, are useful for more than just eating. Cilia are able to move in a coordinated way to propel a Paramecium forward. When an obstacle is encountered, the cilia move in the opposite direction, backing the Paramecium up a bit, before continuing forward, rather like a Roomba trying to vacuum your living room floor.
Paramecium spendmore than half of their energy just on moving, as their short cilia make their movement method less than 1% effective.
If you took science classes in high school or university, you may have encountered Paramecium yourself. Since they reproduce very rapidly and display their organelles through their translucent cytoplasm and membrane, they’re often used in classrooms as model organisms.

Under The Microscope: Cannabis

Originally posted here https://www.mcgill.ca/oss/article/did-you-know-environment/under-microscope-cannabis

Cannabis, commonly known as marijuana, is a genus of plants that encompasses a few different species. The two species commonly used for their psychoactive properties are Cannabis sativa and Cannabis indica, and the third is Cannabis ruderalis.
These three species differ from each other in their cannabinoid concentrations, their psychoactive effects and their cultivation history, but they all have at least one thing in common: trichomes.
The word trichomes comesfrom the Greek word for hair, so it makes sense that trichromeslook a lot like tiny little plant tresses. Trichomes serve a huge variety of purposes depending on the plant, but in all Cannabis speciesthey accumulate cannabinoids like CBD (cannabidiol) and THC (tetrahydrocannabinol), as well as other compounds.
Cannabis plants are dioecious, and it is the female plants that feature trichomes in abundance. As such, it is typically the female Cannabis flowers that are harvested and used for their physiology-altering properties. Trichomes are what makes dried cannabis sticky and smelly. Before harvest, they afford Cannabis plants some protection from small herbivores that are deterred by the strong taste. Cannabis trichomes change colour as the plant matures, from translucent to an amber (as seen in the picture), allowing farmers to use them as a guide of when to harvest their plants.
In other plants trichomes can serve to help keep frost away from leaves, to trap water from the air and even to help catch bugs to eat. The scale-like leaves that cover pineapples are trichomes, as are the prickles that inject irritants on plants like stinging nettle.