Scientific Scribbles

The voice of UniMelb Science Communication students

Reasons why the nephron is a bouncer at a club.

Picture this: a Friday night in Melbourne CBD, outside of the club “Rats”. In the words of Beyoncé “it’s 11:30 and the club is jumpin’, jumpin’” and people are entering and exiting the club. This is what happens in the nephrons in your kidney. Your kidney being the city of Melbourne, and the nephron the club which the youth can’t stay away from.


Yes, that’s right. I am likening glomerular filtration in the kidney to a club in Melbourne CBD. Image created by Author.


Put your dancing shoes on, and let’s head to the club


The nephron is the subunit which makes up your kidney, like your cells making up your body. Within each nephron there is a structure known as the Bowman’s Capsule, or what I like to call the bouncer of the club (with that fancy red rope of course).


People enter and exit out of the club at different rates, like solutes filtering in and out of the nephron from the blood. The rate at which each enters or exits the club depends on what type of person they are.



What type of solute in the club are you?


What I imagine the solutes in the nephron to look like. Image by Matty Adame via Unsplash. 


To get an idea of what we find filtering in the nephron, I have decided to allocate each solute with a type of person at the club:


  1. Those with a VIP pass, or a code. They freely enter and exit the club depending on the amount of people inside or out. The busier the club, the more of these people you will find in there also. I like to think of water having one of those passes; it dilutes the club with sobriety.


  1. Deviant teens who flash their brand new fake ID. They manage to make it into the club, but occasionally are caught. This is the toxins found in our body; generally excreted as waste by the kidney, however if found too young for the club are kicked out to the streets.


  1. We then have those drunks claiming, “I have only had one drink”. They always try to make their way through, but most of the time they will find themselves sitting on the curb in the streets intoxicated. These people are our blood proteins, or what is known as blood albumin. The Bowman’s capsule or bouncer is not permeable to this and it remains in the blood.


  1. If there is one rule we should know, it’s this. To get into a club as a male you must get the female-to-male ratio right when on a night out with the “lads”. Some do, some don’t. These guys are urea; generally only half of them meet this criterion and can enter the club to be excreted.


  1. Our last type, sodium. Or, who I like to call the leaders of the night out with the girls. They decide whether the whole group filter in or out of the club depending on how the night is going. If the club is “popping”, they will lead their friends Potassium, Glucose and Amino acid into the club – these are who I most identify with. This can describe sodium dependent reabsorption or co-transporting of ions into and out of the nephron.



The rowdy crowd of the nephron needs to “evacuate the dancefloor”


Now to answer the question I know you all are asking: How do we get everyone to leave the club or how do we excrete the waste in the nephron?


Well, around 3am this club starts to close. Meaning all the people inside need to leave. Eventually after leaving the club, the people will order an Uber and leave the CBD.  Similarly, the solutes will get kicked out the nephron and exit the kidney, making their way to the bladder.


Now we have likened filtration of the blood in the kidneys to a club in Melbourne CBD, there is one more thing I need to note: unlike the club, this happens all the time. Crazy, I know. Let’s all take a moment to appreciate the work of our kidneys.


Photo by Luke van Zyl on Unsplash

What’s the first thing you do when your alarm goes off in the morning? Almost all of us press snooze. We force our eyes open to see the latest posts on Instagram, as it dominates our lives along with 200 million other individuals around the world that use Instagram to view stories, images and videos. As we continue to hoist ourselves awake, we violently squint to see images of thin emaciated models and celebrities, glorifying perfectionism, immediately making us feel dissatisfied with ourselves from the minute we wake up.

The greater majority of us compare ourselves to these models and become addicted with the constant thought and reminder that, ‘I too can look desirable, I too can starve myself, and train myself to death’. Every so often our insecurities will take over our opinion, rational decision making, power and become toxic to our health. The pursuit for perfectionism leaps far beyond what is normal, and into a compulsive and obsessive lifestyle, as many of us fear gaining weight far more than failing a subject at university. Which begs the question;

Has Instagram made us obsess with how we should look?


Instagram has sparked the addiction that many people between the ages of 18 and 25 have developed. Instagram’s presence in everyone’s life is significant, its influence of the ideal ‘body’ is unavoidable. The incessant pursuit and drive for thinness is impairing young women’s mental health and causing them to make destructive eating and exercise choices, as they are dissatisfied with their image and continue to compare themselves to the famous.

Studies have shown that people who engage in more social comparison tend to have greater dissatisfaction with their body. These negative thoughts are ignited by images and messages posted on Instagram focusing on appearance, body shape and a new found focus of muscularity in women.

Do Instagram pages trigger dissatisfaction with ourselves?


We see communities developing campaigns that drive and encourage the notion of thinness ‘skinnygirlsmakegraves’ and fitness bloggers managing ‘fitspo’ pages, demonstrating how easy it is to become thin. It is easy to see through the façade, that fitness pages merely advocate healthy activities and lifestyle choices, when it is clear that their main focus is more superficial and based on having a perfect appearance. The constant posting of workout videos and selfies infects the minds of many, and results in individuals comparing themselves to others. This ultimately leads to many fearing the thought of gaining weight. This fear is created and constructed so that people feel accepted by society if they conform to the body ideals shaped by the world.

Society sets standards by posting the weight of models, eliciting a sense of adoration of a very thin ideal. The average BMI of a model these days is what we are comparing ourselves to. Instagram contributes to the emergence of eating disorders and body dysmorphia through the influence of pro-eating disorder pages. It was declared by the The New York Post that once women engaged with Instagram platforms that focus on body image and appearance, they exhibited emotions of disappointment with their appearance after viewing images of worshiped celebrities, models and ‘fitspo’ pages.

The science behind the addiction


Dopamine Pathway. Photo credit Curtis Cripe via flickr

The brain is the social organ of the body. Therefore, social media and brain function go hand in hand. The brain’s reward centre responds to sensations of pleasure, via a chemical known as dopamine, naturally stimulating the reward centre. Dopamine is the main neurotransmitter driving the reward pathway. Research suggests that the situation is more complex and that dopamine is not only related to pleasure but even to learning and memory, as it encourages individuals to indent and maintain bad habits. Dopamine changes a person’s perception of liking something to becoming addicted to it.

The brain recognises and registers all pleasures in the same way (i.e. drugs, food, gambling, alcohol). Instagram triggers the release of dopamine in the nucleus accumbens, which allows the prefrontal cortex to communicate in a way that motivates us to take action and to seek out sources of pleasure, in this case starvation and exercise. Over exercising and depriving yourself of food grants your brain with the sense of pleasure, reward, achievement and power. The enjoyment of seeing results and resemblance to Instagram models fuels the addiction.

Obsessing over body image prevails as the brain’s reward system floods the nucleus accumbens with dopamine. The consolidation of memories of pleasure and satisfaction is associated with the hippocampus, leading to continuous repetition of such extreme behaviour. The hippocampus allows the amygdala to build a conditioned response to certain stimuli, such as Instagram and the fear of not looking thin or fit. Instagram exposure results in the amygdala constantly being activated, as individuals are in constant fear of gaining weight or looking bad, which triggers the addiction.


Photo credit Jahnico via flickr

Like any addiction, alcohol is not bad, too much alcohol is bad. Gambling is fun, but too much gambling is dangerous. Instagram is inspiring, too much Instagram is toxic.

Can we make it rain?

With the current drought occurring in parts of Eastern Australia, is there a better time to ask the question: can we make it rain? If you believe everything you hear then Minister for Agriculture and Water Resources has already told us, somewhat definitively, that we cannot make it rain. But is this, like many other things politicians say, fake news? It’s best to start with the basics.

How does rain form?

For a rain droplet to form on its own, the relative humidity (RH) at 5°C would have to be over 300%. So basically, in normal temperatures for the upper troposphere, it would have to be three times wetter than saturated for rain droplets to form.

Instead, they are formed on aerosols known as cloud condensation nuclei (CCN). This way the RH doesn’t have to be so high, because rather than collide with each other, they all just have to stick onto a CCN.

When the droplet grows large enough, it falls out of the sky. Yes, clouds contain liquid and frozen water that floats in the sky – I still can’t really wrap my head around that one.

Image credit: Author


Great, so let’s introduce some CCN and make it rain?

Not so easy. We’ve been trying that in a process known as cloud seeding, where a chemical such as silver iodide is released into the atmosphere as CCN. Let’s just say there have been some mixed results. You see, it depends largely on the weather conditions of the day. Is the temperature just right? Is there enough moisture in the air? Are the clouds of the right type? Is the wind blowing too strongly?

It can go wrong too. There was a recent incident in Tasmania where they chose to attempt cloud seeding inside a weather system that went on to flood parts of the island. Let’s just say, the Tasmanian cloud seeding program is still suspended. Even if they didn’t have any impact on rainfall, it isn’t a good look!

It’s all good news in the Snowy Mountains though, I promise. By introducing silver iodide into the atmosphere, researchers have been able to increase snowfall over the ski fields and raise dam levels.  There have also been some successful efforts in the USA, among many other locations. But these mostly occur when the clouds flow over mountains; again with the really precise conditions!

Can we make it rain over our drought affected areas?

Well, depends where the drought is really. If it’s near the Snowy Mountains then you’re in luck because we can. But it’s not quite like turning on a light switch, we don’t really choose when we can cloud seed. You kind of just go with the flow.

Why shouldn’t we make it rain?

Think of a cloud full of rain as a hot air balloon that is travelling through the sky. Let’s say this balloon drifts over drought affected NSW, so the state government decides they are going to release some silver iodide into the air and make the balloon fall over NSW.

Image credit: Sebastien Gabriel via unsplash.

Now lets say this balloon was originally headed towards New Zealand. If it reached New Zealand, it would have naturally fallen on the dry pastures of the North Island. This would have relieved some needy farmers there too. But we took that balloon before it could reach them.

Is it fair that we took the balloon of water that was destined to reach New Zealand? You could imagine that they wouldn’t be very happy with us.

Let’s also look at the big picture here. We’re in this mess of a rapidly changing climate that produces more frequent, prolonged drought, because of our history of releasing things into the atmosphere. Our best idea to solve this problem is to release more things into the atmosphere. If Darwin is right, I struggle to see how fit we really are for survival, if this is a technique we choose to employ.

So, can we make it rain? Well, technically the answer is yes. But the bigger questions is; do we really want to? I know my answer, what’s yours?

Bird Brain: When size really doesn’t matter

The wonderful Aves, who reached the skies far before any human, are also capable of love, dreaming, problem solving, making tools, reflecting, socialising and playing. Photo Credit: Nicola Bail

They’re on our coat of arms, but from my most recent experience when camping last summer, I’m hoping that emus aren’t a representation of our national education system. With glowing red eyes, a misty grey plumage and a low booming mating sound resonating from a throat almost a meter in length, the female emu trespassing on our camping site cut a rather impressive figure…until she tripped over a branch, walked into the fire and tried to peck our eggs out of boiling water.

Watching and snapping pictures from the safety of our tents we realised that the second largest bird in the world, Dromaius novaehollandiae,with prehistoric tridactyl feet, was looking increasingly goofy as she tried to pick an egg out of boiling water five times, almost ran into the fire twice and tried to drink the fuel, before we hustled her away. Someone snorted “What a bird brain…” and we all laughed, secure in our own Homo sapien cognitive capabilities.

Bird-brained or brilliant? Our campfire visitor. Photo Credit: Daisy Hodgson

But as we sat around the fire with our big brains comfortably attached to our necks, we began swapping stories of feathered tricksters, ravens who could open school-bag zippers and Tupperware, cockatoos who knock on windows for food and Alex the African Grey parrot, famous for his way with language and whose last words when he passed away in 2007 were, “You be good, see you tomorrow. I love you.”

“Of all the animals, man has the brain largest in proportion to his size.”


Early hypotheses often used brain-to-body-mass ratio as a rough estimate of intelligence in animals. If that was the case however, Homo sapien ‘exceptionalism’ might be side-lined by the mere ant, whose brain is a seventh of its total body weight, or a shrew which holds 10% of its mass in its brain (the adult human brain is a mere 1/50thof its total mass). Luckily, neuroanatomists developed a consolation prize, the “encephalisation quotient” (EQ).

Ummm…are you sure you don’t mean IQ?

 EQ, developed in the late 19thcentury takes into account the weight of the brain, body and allometry, a physiological scaling factor.

Using this scale, humans ranked first with our egos in place, at 8 EQ, Chimpanzees at 4.2 EQ, with parrots and corvids (crows, ravens and magpies) close to primates at approximately 4 EQ.

Is it only PROPORTION that matters?

Proboscis monkey(left) in all his glory with an oriental pied hornbill (right) at Singapore Zoo.Photo Credit: Daisy Hodgson

A 2016 study found that avian brains have more neurons per area and are more densely packed than in primates of the same mass. The pallium (cerebral cortex equivalent) of parrots and songbirds were found to have similar organisation to primates but with a greater proportion of neurons. This increased neural density of the pallium which supports an animal’s ability to plan and find patterns could potentially give avian brains greater cognitive power per area than larger mammals.

Rock a bye…birdy?

Zebra Finches dream of singing Photo Credit: Michael Lawton/ Flickr

Neuroimaging in songbirds has also given an insight into the dreams of birds, specifically, zebra finches. A 1998 study found that when the birds sung, electrical impulses from the robustus archistriatalis (RA) showed up as regular oscillating activity and when the birds slept, their RA showed less oscillating but still highly active impulses, suggesting the songbirds dreamt of segments of their own song, or consolidated songs they learned during the day.

Myth sharing in a murder of crows

Intelligent bird species are often long-living and social, allowing them to accumulate knowledge and learn from other members in their family group. Photo Credit: Gerry Zeck

Wildlife biologists put into practice whether crows can recognise those who have wronged them. Wearing a ‘caveman mask’, scientists tagged several crows, measured neural responses, then released them on Washington University campus. They found in the following months…and then years…whenever students donned the ‘caveman masks,’ nearby crows would flap, caw and swoop persistently, even if they hadn’t even been born when the study was first conducted! And when a dead crow was presented to caught live crows, the amygdala–emotional memory – and the hippocampus– long term memory formation – showed a burst of activity during neuroimaging, suggesting the crows understood the death of one of their ownand the danger this ‘caveman’ presented.

Much like how parents pass on the fear of the bogeyman, myths of dangerous cavemen who hassle and tag you can be passed among crows.

This learned behaviour has also been observed in crows in a district of Japan,who leave nuts on pedestrian crossings, wait for cars to break open shells and coordinate collection with traffic lights. Since this behaviour was first observed, locals have noticed numerous crows lining up at walk-ways, waiting to retrieve lunch and shells littering pedestrian crossings.

Consider this…

While many of us struggle to remember where we left our keys or phone, jaybirds exhibit tremendous recall, retrieving hidden seeds and nuts. The New Caledonian crowis the handyman we all need in our lives; bending wires to fish out baskets and even their own feathers to nudge out juicy grubs and the Heron is a skilled fisherman, using insects and leaves as bait by casting them out into water.

A kindling partnership with our emu friend Photo Credit: Daisy Hodgson

With their incredible potential for learning, it seems wrong that corvids and parrots are chided for squawking in a language we don’t understand. So rather than treating ravens as pests and lording our own cognitive prowess, perhaps we could take an example from a French theme park which has delegated several ravens to picking up rubbish – rather than pulling it out of bins – and enter into a partnership with the Aves.














The universally successful birthday gift that can save the world

Not all of us are this savvy at gift giving. Could climate change help? Photo by rawpixel via Unsplash.

As much as I love the concept of birthdays, sometimes the sheer stress of deciding on, acquiring and decoratively packaging birthday gifts is enough to inspire a Leonardo DiCaprio style escape to a deserted island. That was until I found the ultimate birthday gift. A gift that not only proved to be immensely well-received by whoever I bestowed it upon, but a gift that so happened to have the power of saving the world too.

It’s actually a coffee table book. But a well-researched, highly aesthetic, easy-to-read one outlining the top 100 solutions known to humankind to mitigate climate change. Drawdown, edited by Paul Hawken, is the “most comprehensive plan ever proposed” to save our planet, compiled by a team of scientists and mathematicians who crunched the numbers and found out which solutions could prevent the most gigatonnes of carbon from entering our atmosphere. It also happens to be very entertaining.

The last chapter is arguably the juiciest, filled with innovative technological and novel solutions currently in development. They are exciting enough that the authors opted out of the standard “Upcoming Solutions” chapter title, instead going for a more themepark-esque: “Coming Attractions”. Here are some you may find particularly fascinating.

Marine Permaculture

The late Bill Mollison, founder of permaculture, probably would not have conceived of his ecological design principles being implemented away from solid ground. Fast-forward forty years and Dr Brian Von Herzen and his team are doing just that. Picture floating kelp forests, hundreds of acres across, attracting fish and seabirds and a host of other marine life, all the while drawing down billions of tonnes of carbon.

If we help the kelp, the kelp can help us. Photo by Chris Johnson via Flickr.

The principle is relatively straightforward – a lightweight floating lattice provides an anchor for kelp and seaweeds to grow. Utilising wave energy to power pumps, nutrient-rich cold waters are pumped to the ocean surface, where they stimulate kelp growth. Economically speaking, the kelp can be harvested and sold as human or animal food. Essentially, sushi could be the next top model for cooling the climate.

Smart Highways

Over 800,000 kilometres of roadways criss-cross Australia. In city streets during peak summer, burning asphalt can melt even a sturdy pair of Docs, while stagnant exhaust fumes clog the suburbs. Yet given their prevalence, roads present a prime opportunity for environmental innovation. ‘Smart highways’ can utilise solar photovoltaic paving (see ‘The Ray‘) or noise barriers lined with solar panels, linked to local charging stations to cater for the future wave of electric cars.

Road lane markings could use bio-luminescent paints to glow at night, inspired by algae such as these. Image by viceyberreta via Flickr.

Simpler technologies such as bio-luminescent paints which glow as lane markings at night, or even installing LED road lighting, can reduce infrastructure emissions. Of course, the less reliance on roads the better, with other transportation solutions ranked highly in Drawdown’s list: bicycle infrastructure (#59), walkable cities (#54) and mass transit (#37). Get cycling.

Repopulating the Mammoth Steppe

As it turns out, the future of our planet may not rely upon wind turbines on nuclear fusion, but upon Siberian horses. As this scientific report alluded to last week, the melting of the earth’s northern latitude permafrost could release huge amounts of carbon and methane, further warming the planet in a devastating feedback loop. A proposed solution then? Repopulate the permafrost lands with the grazing herbivores which once roamed freely.

The new climate change warrior: keeping the permafrost frosty. Photo by Jan Nagalski via Flickr.

As reindeer, oxen and horses scratch away the snow to reveal the edible turf beneath, the soil is no longer insulated and remains 3 to 4°F cooler. Reintroducing hordes of animals to these landscapes could foster mass revegetation while preventing permafrost melting. In the words of the editors, it could be the “single largest solution or potential solution of the one hundred in this book”.  Welcome back Sid, Scratch and Manfred.

So… worthy of a gift?

If that little taste of climate change mitigation didn’t appeal to you, then guaranteed a handful of the other 97 ideas will. Either way, spread the word: we have a host of global and local solutions at our fingertips, we just have to choose to implement them. And who knew solving climate change could be so fun?

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