Weekly Dose: new drug MDPV, or ‘monkey dust’, found in Australia. What is it and what are the harms?

Source: The Conversation (Au and NZ) – By Samuel Banister, Team Leader in Medicinal Chemistry, University of Sydney

Recent media reports have suggested a rise in a dangerous new party drug known as “monkey dust”. This is a slang name for the drug MDPV (3,4-methylenedioxypyrovalerone), as well as other members of the chemical class known as “synthetic cathinones”, or “bath salts”.

The effects of monkey dust are similar to other stimulants such as ecstasy (MDMA) and cocaine. Revellers may be using the drug on purpose as a substitute for these, or may mistakenly think it’s MDMA. However, the potency and effects are different, and can lead to trouble.

Synthetic cathinones are synthetic derivatives of a stimulant found in the khat plant, a flowering plant native to the Horn of Africa and the Arabian Peninsula. More than 140 individual synthetic cathinones have been identified as illicit drugs, so users can never be certain about a substance from its street name alone.

This class also includes drugs you may have heard of before including ephylone (the dangerous drug detected recently via pill testing at an Australian music festival), methylone, and mephedrone.


Read more: Weekly Dose: ephylone, the dangerous designer stimulant found at Groovin the Moo


What is MDPV?

MDPV was developed by pharmaceutical firm Boehringer Ingelheim in the mid-1960s as a central nervous system stimulant. But development never got far enough for it to be tested on humans.

It first reappeared in internet drug forum discussions around 2005, and became increasingly prevalent in the United States, Europe and elsewhere over the following years.

MDPV has been illegal in Australia since 2010, and around the same time in many other jurisdictions including the United States, Canada, and much of Europe, accounting for a decline in its availability.

The Drug Enforcement Administration reported that MDPV accounted for more than 50% of all synthetic cathinones encountered in law enforcement seizures in the US by 2011. The proportion had dropped to less than 1% by 2015.

The recent seizure of more than four kilograms of MDPV imported into Australia suggests a market for the drug still exists.

MDPV is a white crystalline powder in its pure form, but manufacturing impurities often render it from off-white to pale brown. It’s usually sold as a powder, powder-filled capsules or tablets. MDPV and other cathinones are often misrepresented as MDMA for sale due to similar appearance and some common effects. Laboratory testing of street pills containing MDPV shows it’s commonly mixed with other drugs.


Read more: Weekly Dose: ecstasy, the party drug that could be used to treat PTSD


What does MDPV do?

An oral dose of MDPV is estimated to be around 5-20 milligrams (compared to 100-150 milligrams for MDMA). The main psychoactive effects last two to three hours, and side-effects persist for several additional hours.

Users report MDPV produces euphoria, feelings of empathy (although less so than MDMA), increased sociability, mental and physical stimulation, and sexual arousal.

Side-effects, particularly at high doses, can include anxiety and paranoia, delusions, muscle spasms, and an elevated heart rate. In extreme cases, MDPV has been linked to rhabdomyolysis (rapid muscle breakdown), brain injury, and death.

Animals in lab studies wanted to self-administer the drug, meaning it’s addictive. from www.shutterstock.com

Like other cathinones, MDPV is a stimulant and shares some effects with other stimulants such as amphetamine, cocaine and MDMA. MDPV produces its effects by inhibiting the reuptake of two important signalling molecules (neurotransmitters) in the brain; norepinephrine and dopamine.

Norepinephine is generally responsible for preparing the brain and body for action in the so-called “fight or flight response”, while dopamine is involved in more complex functions such as arousal, motivation, reward and motor control.

By blocking the ability of certain brain cells (neurons) to reabsorb these neurotransmitters, MDPV effectively increases the intensity and duration of norepinephrine and dopamine signalling. Cocaine works in a similar way, but in a lab test, MDPV was a much more potent inhibitor than cocaine.

Other norepinephrine-dopamine reuptake inhibitors (NDRIs) include pharmaceuticals such as methylphenidate (known as ritalin and used to treat ADHD) and buproprion (an antidepressant). But the psychoactive and stimulant effects of MDPV are much stronger than pharmaceutical NDRIs.

Pyrovalerone – a hybrid of mephedrone and MDPV – is an approved appetite suppressant used medically for weight loss. However, it’s rarely used due to its potential for abuse.

Studies in laboratory animals highlight the stimulating effects of MDPV, and also its potential for dependence. Mice trained to identify MDPV find it similar to both MDMA and methamphetamine. MDPV stimulates movement in rats approximately ten times more potently than cocaine, and rats will readily self-administer MDPV, suggesting it’s addictive.

Dangers

MDPV has been involved in dozens of deaths in Europe, detailed in a report by the European Monitoring Centre for Drugs and Drug Addiction, as well as in the United States, Australia, and elsewhere.

But many of these deaths involved extreme doses, repeated dosing (“bingeing”), intravenous use or additional drugs. In fatal cases involving a single synthetic cathinone, death has been attributed to complications arising from extremely high body temperatures or damage to the vessels of the heart. Fortunately, specialised drug testing can detect MDPV and its derivatives.

Although simple colour-based reagent tests may identify MDPV, these tests may also cross-react with similar cathinones, some of which are less dangerous, and some of which are more so.

For reliable identification, more sophisticated technology such as mass spectrometry or infrared spectroscopy, of the type drug experts are campaigning to take place at festivals, is required. In this regard, small, portable, and relatively cheap infrared analysers may be useful for on-site testing services.


Read more: While law makers squabble over pill testing, people should test their drugs at home


ref. Weekly Dose: new drug MDPV, or ‘monkey dust’, found in Australia. What is it and what are the harms? – http://theconversation.com/weekly-dose-new-drug-mdpv-or-monkey-dust-found-in-australia-what-is-it-and-what-are-the-harms-109505

MIL Analysis+Reportage – EveningReport.NZ

A current affair: the movement of ocean waters around Australia

Source: The Conversation (Au and NZ) – By Charitha Pattiaratchi, Professor of Coastal Oceanography, University of Western Australia

Many people in Australia will head to the beach this summer and that’ll most likely include a dip or a plunge into the sea. But have you ever wondered where those ocean waters come from, and what influence they may have?

Australia is surrounded by ocean currents that have a strong controlling influence on things such as climate, ecosystems, fish migrations, the transport of ocean debris and on water quality.

We did a study, published in April 2018, that helps to give us a better understanding of those ocean currents.

Surface currents around the Australian continent. Ems Wijeratne/Charitha Pattiaratchi/Roger Proctor


Read more: New map shows that only 13% of the oceans are still truly wild


Go with the flow: Indian Ocean

Our 15 year simulation indicates that water from the Pacific Ocean enters the Indonesian Archipelago through the Mindanao current (north) and Halmahera Sea (south).

It then enters the Indian ocean as the Indonesian Throughflow between many Indonesian Islands, with flow through the Timor Passage being the most dominant.

Most of this water flows west as the South Equatorial Current. Re-circulation of the SEC creates the Eastern Gyre that contributes to the Holloway Current. This in turn feeds the Leeuwin Current – the longest boundary current in the world (Ocean currents that flow adjacent to a coastline are called boundary currents)

The Leeuwin Current is the major boundary current along the west coast and as it moves southward. Indian Ocean water is supplied by the South Indian Counter Current increasing the Leeuwin Current transport by 60%.

The Leeuwin Current turns east at Cape Leeuwin, in Western Australia’s south-west, and continues to Tasmania as the South Australian and Zeehan Currents.

The Leeuwin Current passes the lighthouse at the Cape Leeuwin in WA. Flickr/Cheng, CC BY-NC-ND

There is a strong seasonal variation in the strength of the boundary currents in the Indian Ocean with a progression southwards of the peak transport along the coast.

The Holloway Current peaks in April/May (coinciding with changes in the monsoon winds), the Leeuwin Current reaches a maximum along the west and south coasts in June and August.


Read more: Climate change is slowing Atlantic currents that help keep Europe warm


Go with the flow: Pacific Ocean

In the Pacific Ocean, the northern branches of the South Equatorial Current are the main inputs initiating the Hiri Current and East Australian Current.

At around latitude 15 degrees south the currents split in two: southward to form the East Australian Current, and northward to form the Hiri Current which contributes to a clockwise gyre in the Gulf of Papua.

The East Australian Current is the dominant current in the region transporting 33 million cubic metres of water per second southward.

At around 32S, the East Australian Current separates from the coast and 60% of the water flows eastward to New Zealand as the Tasman Front. The remaining 40% flows southward as the East Australian Current extension and contributes to the Tasman Outflow.

The Tasman outflow is the major conduit of water from the Pacific to Indian Ocean and contributes to the Flinders Current, flowing westward from Tasmania and past Cape Leeuwin into the Indian Ocean.

Along the southern continental slope, the Flinders Current appears as an undercurrent beneath the Leeuwin Current and a surface current further offshore. The Flinders Current contributes to the Leeuwin Undercurrent directly as a northward flow, flowing to the north-west of Australia in water depths 300 metres to 800 metres.

Impact of the currents

Understanding ocean circulation is a fundamental tenet of physical oceanography and scientists have been charting the pathways of ocean currents since the American hydrographer Matthew Maury, one of the founders of oceanography, who first charted the Gulf Stream in 1855.

One of the first maps of circulation around Australia was by Halliday (1921) who showed the movement of “warm” and “cold” waters around Australia. Although some of the major features (such as the East Australian Current) were correctly identified, a more fine scale description is now available.

Ocean surface currents around Australia by Halliday 1921.

The unique feature of ocean currents around Australia is that along both east and west coasts they transport warmer water southwards and influence the local climate, particularly air temperature and rainfall, as well as species distribution.


Read more: Explainer: how the Antarctic Circumpolar Current helps keep Antarctica frozen


For example, the south west of Australia is up to 5C warmer in winter and receives more than double the rainfall compared to regions located on similar latitudes along western coastlines of other continents.

Similarly many tropical species of fish are found in the southwest of Australia that hitch a ride on the ocean currents.

The Pacific Ocean is the origin of waters around Australia with a direct link to the east and an indirect link to west.

Ocean water from the Pacific Ocean flows through the Indonesian Archipelago, a region subject to high solar heating and rainfall runoff, creating lower density water. This water, augmented by water from the Indian Ocean, flows around the western and southern coasts, converging along the southern coast of Tasmania.

So next time you head for a dip in the coastal waters around Australian, spare a thought for where that water has come from and where it may be going next.

Time for a plunge in the water at Bondi Beach, NSW. Flickr/Roderick Eime, CC BY-ND

ref. A current affair: the movement of ocean waters around Australia – http://theconversation.com/a-current-affair-the-movement-of-ocean-waters-around-australia-96779

MIL Analysis+Reportage – EveningReport.NZ

Curious Kids: how do tongues taste food?

Source: The Conversation (Au and NZ) – By Paulomi (Polly) Burey, Senior Lecturer (Food Science), University of Southern Queensland

Curious Kids is a series for children. Kids can send questions to curiouskids@theconversation.edu.au. You might also like the podcast Imagine This, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.


How do tongues taste food? – Ridley, age 4, Melbourne.


Dear Ridley,

This is a really good question. Tasting food actually uses all of your senses. Your senses gather up all the information and combine it into a message about the taste of food that gets sent to your brain. For example, your eyes help you recognise food and remember how it tastes.

It’s not just about the tongue. The five senses – taste, touch, sight, hearing and smell – help collect messages about a food and send it to your brain. Shutterstock


Read more: Curious Kids: How do we get allergic to food?


Your tongue has special parts that pick up flavour, bundled together as taste buds. They help you taste different flavours, like sweet, salty, sour, bitter, and a special one called “umami” which some people say is a bit like a mix of all the others put together.

The taste buds pick up clues about how a food tastes and sends messages about it to your brain along special wires called nerves.

Your brain gets messages from your taste buds via nerves. Shutterstock

To taste something properly, you need to chew food into small pieces and to have a lot of drool, or saliva. This help the flavour molecules (also known as “tastants”) reach your taste buds.

This picture shows a close-up of taste buds on a tongue. Shutterstock

Try this experiment: if you lick a piece of sliced apple, how does it taste? Now drink some water to wash away the flavour, and take a bite of the apple and chew it up. When you cut an apple, only some flavour is released. But if you chew it into smaller pieces, more flavour can escape into your mouth.

Foods taste sweeter if the sugar particles are smaller. Want to try another experiment? With permission, put some large sugar crystals on your tongue for five seconds. How sweet do they taste? Now rinse your mouth with water and put some fine icing sugar on your tongue – is it sweeter or less sweet than the big sugar crystals?

The smaller the sugar particles are, the easier it is for your tongue to taste the sweetness. (For the adults reading, this is because smaller particles have a higher surface area). This trick helps food scientists develop sweet foods with less sugar.

Saliva and smell

When you chew your food, you also produce saliva (or spit) which dissolves some of the food flavour for your to tongue taste.

Want to try another experiment? Stick out your tongue as far as it can go and dry the saliva off with some thick paper towel. While your tongue is still sticking out, have your parent put some food on your tongue, like yoghurt. How strong is the flavour? Next, pull your tongue back into your mouth and taste the food. Is the flavour stronger, weaker, or the same?

If your nose is blocked, food tastes weaker. This is because your nose also helps you “taste” food too.

Try it! While holding your nose closed, put some food in your mouth and chew. Can you taste it? While still eating the food, let go of your nose and keep eating. Is the flavour stronger, weaker, or the same?

In fact, without your sense of smell it can be hard to taste the difference between a raw apple and a raw onion!

When it comes to tasting flavour, your nose helps a lot. Flickr/Bruce Tuten, CC BY

So your tongue and nose work together to help you taste your food. I hope you can help your tongue taste more by chewing your food fully and using your saliva to help make the flavour stronger.

And if you have something to eat that you don’t like, try holding your nose!


Read more: Curious Kids: why do some people find some foods yummy but others find the same foods yucky?


Hello, curious kids! Have you got a question you’d like an expert to answer? Ask an adult to send your question to curiouskids@theconversation.edu.au

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Please tell us your name, age and which city you live in. We won’t be able to answer every question but we will do our best.

ref. Curious Kids: how do tongues taste food? – http://theconversation.com/curious-kids-how-do-tongues-taste-food-103744

MIL Analysis+Reportage – EveningReport.NZ