Psychedelic mushrooms dramatically increase connectivity between otherwise uncommunicative parts of the brain, according to researchers from Imperial College London in an article to be published in the November edition of the Royal Society's journal Interface.
Paul Expert and his team analyzed functional magnetic resonance imaging (fMRI) data from two groups of people -- one who had ingested a small amount of the active agent in hallucinogenic mushrooms, psilocybin, and another group who was given a placebo.
They found that the main effect was the creation of stable connections between parts of the brain that, under normal conditions, only communicate with each other in dream states -- such as the hippocampus (which deals with short term memory and spatial recognition) and anterior cingulate cortex (which regulates rational cognitive functions).
The result of this stable cross-wiring is a more interconnected brain, as shown on the diagram below:
[caption id="attachment_666255" align="alignnone" width="615"]Image via Interface[/caption]
On the left is a data visualization of a brain administered the placebo; on the right, one that has been subjected to a mild dose of psilocybin.
"We can speculate on the implications of such an organization," Dr. Expert said. "One possible by-product of this greater communication across the whole brain is the phenomenon of synaesthesia" -- which is the experience of having senses overlap, such that certain smells are accompanied by flashes of color, or certain sounds are accompanied by tastes.
It is also believed that rewiring the brain in this manner may allow scientists to find more effective ways to treat depression or help smokers and alcoholics battle their addictions.
This research is only possible thanks to a a recent loosening on the regulations regarding the study of psychedelic drugs for medical purposes. This is a positive measure, said study co-author Giovanni Petri, who toldWired that "in a normal brain, many things are happening. You don’t know what is going on, or what is responsible for that. So you try to perturb the state of consciousness a bit, and see what happens."
Micellar water, a product found in supermarkets, chemists and bathroom cabinets around the world, is commonly used to remove make-up. It’s a very effective cleanser and many people swear by it as part of their skincare routine.
So, what is micellar water and why is it so good at getting makeup and sunscreen off? Here’s the science.
What are micelles?
Oil and water generally don’t mix, which is why you’ll struggle to remove makeup and sunscreen (which both contain oils) with just plain water.
But micellar water products contain something called micelles – clusters of molecules that are very effective at removing oily substances. To understand why, you need to first know two chemistry terms: hydrophilic and hydrophobic.
A hydrophilic substance “loves” water and mixes easily with it. Salt and sugar are examples.
A hydrophobic substance “hates” water and generally refuses to mix with it. Examples include oil and wax.
Hydrophilic materials will happily mix with other hydrophilic materials. The same goes for hydrophobic substances. But if you try to combine hydrophilic and hydrophobic materials, they won’t mix.
How are micelles formed? It’s all about surfactants
The micelles in micellar water are formed by special molecules known as surfactants.
Surfactant stands for surface active agent. These molecules looked at their hydrophilic and hydrophobic brethren and said, why not both? They are typically comprised of two ends: a head group that is hydrophilic and a tail that is hydrophobic.
A surfactant has a head that is hydrophilic and a tail that is hydrophobic. Daniel Eldridge
When a small amount of surfactant is added to water, the two ends of the molecule have competing interests. The hydrophilic head wants to be in the water, but the hydrophobic tail can’t stand water.
Add enough surfactant and, eventually, we will pass a critical micelle concentration and the surfactants will self-assemble into clusters of approximately 20 to 100 surfactant molecules.
All the hydrophilic heads will be pointing outwards, while the hydrophobic tails remain “hidden” at the centre. These clusters are micelles.
Surfactant molecules arrange themselves into a micelle, with the hydrophilic heads pointing outwards and the hydrophobic tails pointing inwards. Daniel Eldridge
These micelles have a hydrophilic exterior, meaning that they are very happy to remain mixed throughout water. However, in the centre remains a hydrophobic pocket that’s very good at attracting oils.
This is very handy, and helps explain why adding some detergent (a surfactant) to water will allow you to wash an oily saucepan. The surfactant first helps lift of the oil, and then the oil can remained mixed into the water, finding a new home in the hydrophobic centre of the micelle.
Micellar water in action
Surfactants are in your dishwashing detergent, your body wash, your shampoo, your toothpaste and even many foods. In all of these cases, they are there to help the water interact with the dirt and oils, and micellar water is no different.
When you apply some micellar water to a cotton pad, another convenient interaction occurs. The wet cotton is hydrophilic (loves water). Consequently, some of the micelles will unravel, with the hydrophilic heads being attracted to the wet cotton pad.
Now, sticking out from the surface will be a layer of hydrophobic tail groups. These hydrophobic tails cannot wait to attract themselves to makeup, sunscreen, oils, dirt, grease and other contaminants on your face.
As you sweep the cotton pad across your skin, these contaminants bind to the hydrophobic tails and are removed from the skin.
Some contaminants will also find themselves encapsulated in the hydrophobic centres of the micelle.
Either way, a cleaner surface is left behind.
Look at how a cotton wipe soaked in micellar water cleans up a small oil spill, in comparison to water alone.
So why shouldn’t I just use dishwashing detergent to wash my face?
Technically, that would work as detergent does indeed contain lots of micelle-forming surfactants.
But these particular surfactants would probably cause a lot of skin and eye irritation, while also damaging and drying out your skin. Not nice.
The surfactants in micellar water are chosen to be mild and well tolerated by most people’s skin. But micellar water isn’t the only skincare product to contain micelles. There are many other face-cleaning products that also make great use of surfactant molecules and work very well too.
Now, it’s not perfect. While it is effective at removing a wide range of contaminants, thick or heavy makeup might not come off easily with micellar water (you might need to do a more vigorous clean).
Some products say there is “zero residue”, although the fine print clearly states this refers to visible residue.
Many products also state there is no rinse off required. Surfactants will remain on your skin after product use, but for many people they don’t cause irritation. If your skin is feeling irritated after using a micellar water product, you can try rinsing afterwards or discontinuing use.
And as is the case with many cosmetic products, you should test it first on a small patch of skin before using it all over your face.
It’s an all too common situation – you’re busy cooking or baking to a recipe when you open the cupboard and suddenly realise you are missing an ingredient.
Unless you can immediately run to the shops, this can leave you scrambling for a substitute that can perform a similar function. Thankfully, such substitutes can be more successful than you’d expect.
There are a few reasons why certain ingredient substitutions work so well. This is usually to do with the chemistry and the physical features having enough similarity to the original ingredient to still do the job appropriately.
Let’s delve into some common ingredient substitutions and why they work – or need to be tweaked.
Oils versus butter
Both butter and oils belong to a chemical class called lipids. It encompasses solid, semi-solid and liquid fats.
In a baked product the “job” of these ingredients is to provide flavour and influence the structure and texture of the finished item. In cake batters, lipids contribute to creating an emulsion structure – this means combining two liquids that wouldn’t usually mix. In the baking process, this helps to create a light, fluffy crumb.
One of the primary differences between butter and oil is that butter is only about 80% lipid (the rest being water), while oil is almost 100% lipid. Oil creates a softer crumb but is still a great fat to bake with.
You can use a wide range of oils from different sources, such as olive oil, rice bran, avocado, peanut, coconut, macadamia and many more. Each of these may impart different flavours.
Other “butters”, such as peanut and cashew butter, aren’t strictly butters but pastes. They impart different characteristics and can’t easily replace dairy butter, unless you also add extra oil.
Nut ‘butters’ can’t replace dairy butter because their composition is too different. congerdesign/Pixabay
Aquafaba or flaxseed versus eggs
Aquafaba is the liquid you drain from a can of legumes – such as chickpeas or lentils. It contains proteins, kind of how egg white also contains proteins.
The proteins in egg white include albumins, and aquafaba also contains albumins. This is why it is possible to make meringue from egg whites, or from aquafaba if you’re after a vegan version.
The proteins act as a foam stabiliser – they hold the light, airy texture in the product. The concentration of protein in egg white is a bit higher, so it doesn’t take long to create a stable foam. Aquafaba requires more whipping to create a meringue-like foam, but it will bake in a similar way.
Another albumin-containing alternative for eggs is flaxseed. These seeds form a thick gel texture when mixed with a little water. The texture is similar to raw egg and can provide structure and emulsification in baked recipes that call for a small amount of egg white.
Lemon plus dairy versus buttermilk
Buttermilk is the liquid left over after churning butter – it can be made from sweet cream, cultured/sour cream or whey-based cream. Buttermilk mostly contains proteins and fats.
Cultured buttermilk has a somewhat tangy flavour. Slightly soured milk can be a good substitute as it contains similar components and isn’t too different from “real” buttermilk, chemically speaking.
One way to achieve slightly soured milk is by adding some lemon juice or cream of tartar to milk. Buttermilk is used in pancakes and baked goods to give extra height or volume. This is because the acidic (sour) components of buttermilk interact with baking soda, producing a light and airy texture.
Buttermilk can also influence flavour, imparting a slightly tangy taste to pancakes and baked goods. It can also be used in sauces and dressings if you’re looking for a lightly acidic touch.
Honey is a complex sugar-based syrup that includes floral or botanical flavours and aromas. Honey can be used in cooking and baking, adding both flavour and texture (viscosity, softness) to a wide range of products.
If you add honey instead of regular sugar in baked goods, keep in mind that honey imparts a softer, moister texture. This is because it contains more moisture and is a humectant (that is, it likes to hold on to water). It is also less crystalline than sugar, unless you leave it to crystallise.
The intensity of sweetness can also be different – some people find honey is sweeter than its granular counterpart, so you will want to adjust your recipes accordingly.
Honey has a complex flavour and can taste sweeter than regular sugar. estelheitz/Pixabay
Gluten-free versus regular flour
Sometimes you need to make substitutions to avoid allergens, such as gluten – the protein found in cereal grains such as wheat, rye, barley and others.
Unfortunately, gluten is also the component that gives a nice, stretchy, squishy quality to bread.
To build this characteristic in a gluten-free product, it’s necessary to have a mixture of ingredients that work together to mimic this texture. Common ingredients used are corn or rice flour, xanthan gum, which acts as a binder and moisture holder, and tapioca starch, which is a good water absorbent and can aid with binding the dough.
When the first cane toads were brought from South America to Queensland in 1935, many of the parasites that troubled them were left behind. But deep inside the lungs of at least one of those pioneer toads lurked small nematode lungworms.
Almost a century later, the toads are evolving and spreading across the Australian continent. In new research published in Proceedings of the Royal Society B, we show that the lungworms too are evolving: for reasons we do not yet understand, worms taken from the toad invasion front in Western Australia are better at infecting toads than their Queensland cousins.
An eternal arms race
Nematode lungworms are tiny threadlike creatures that live in the lining of a toad’s lung, suck its blood, and release their eggs through the host’s digestive tract. The larva that hatch in the toad’s droppings lie in wait for a new host to pass by, then penetrate through its skin and migrate through the amphibian’s body to find the lungs and settle into a comfortable life, and begin the cycle anew.
Parasites and their hosts are locked into an eternal arms race. Any characteristic that makes a parasite better at finding a new host, setting up an infection, and defeating the host’s attempts to destroy it, will be favoured by natural selection.
Over generations, parasites get better and better at infecting their hosts. But at the same time, any new trick that enables a host to detect, avoid or repel the parasites is favored as well.
So it’s a case of parasites evolving to infect, and hosts evolving to defeat that new tactic. Mostly, parasites win because they have so many offspring and each generation is very short. As a result, they can evolve new tricks faster than the host can evolve to fight them.
The march of the toads
The co-evolution between hosts and parasites is most in sync among the ones in the same location, because they encounter each other most regularly. A parasite is usually better able to infect hosts from the local population it encounters regularly than those from a distant population.
But when hosts invade new territory, it can play havoc with the evolutionary matching between local hosts and parasites.
Since cane toads were released into the fields around Cairns in 1935, the toxic amphibians have hopped some 2,500 kilometres westwards and are currently on the doorstep of Broome. And they have changed dramatically along the way.
The Queensland toads are homebodies and spend their lives in a small area, often reusing the same shelter night after night. As a result, their populations can build up to high densities.
For a lungworm larva, having lots of toads in a small area, reusing and sharing shelter sites, makes it simple to find a new host. But at the invasion front (currently in Western Australia), toads are highly mobile, moving over a kilometre per night when conditions permit, and rarely spending two nights in the same place.
At the forefront of the invasion, toads are few and far between. A lungworm larva at the invasion front, waiting in the soil for a toad to pass by, will have few opportunities to encounter and infect a new host.
Lungworms from the invasion front
When hosts are rare, we expect the parasite will evolve to get better at infecting the ones it does encounter, because it is unlikely to get a second chance.
To understand how this co-evolution is playing out between cane toads and their lungworms, we did some experiments pairing hosts and parasites from different locations in Australia. What would happen when toad and lungworm strains that had been separated by 90 years of invasion were reintroduced to each other?
To study this we collected toads from different locations, bred them in captivity and reared the offspring in the lab under common conditions. We then exposed them to 50 lungworm larvae from a different area of the range, waited four months for infections to develop, then killed the toads and counted how many adult worms had successfully established in their lungs.
As expected, worms from the invasion front were best at infecting toads, not just their local ones. Behind the invasion front, in intermediate and old populations we found that hosts were able to fight their local parasites better than those from distant populations.
While we saw dramatic differences in infection outcomes, we have yet to determine what biochemical mechanisms caused the differences and how changes in genetic variation of host and parasite populations might have shaped them.