Our Changing World

There is a fine art to how pedestrians, cyclists, and cars and buses navigate the shared thoroughfares of our towns and cities.

There is a fine art to how pedestrians, cyclists, and car and bus drivers navigate the shared thoroughfares of our towns and cities. And in some places, e-scooters are adding to the confusion.

It's a busy research area for sociologist and cyclist Dr Mike Lloyd, from Victoria University of Wellington.

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When the first sharrows - share the road arrows - began to appear on Wellington streets, Mike Lloyd headed out on his bike. He had a GoPro mounted on his head, to record the experience.

When there was a fuss about the design of the new Island Bay cycleway, Mike was there on his bike again.

As e-scooters became a ubiquitous presence in our larger cities, Mike was one of the first to leap on board one and begin observing other riders.

Back in his office, Mike analyses the experience frame-by-frame.

Mike is interested in interactions: between a pedestrian and a cyclist, for example, or between a car driver and a cyclist.

Mike's research interest is how we navigate these shared spaces and in understanding the subtleties of how we acknowledge and accommodate each other.

He says that both looks and non-looks are important. Even a very short glance can be enough to tell one party that the other party has seen them and will make allowances.

But what if the other person appears not to have seen you - are they actually 'being oblivious' or are they doing what Mike calls 'doing oblivious.'

A person 'doing oblivious' is aware of the other person but pretends not to have seen them. It's thought that this helps give them priority, as the other person has to act cautiously and give way to avoid an accident.

Mike's research aims to add a sociological dimension to traffic management in addition to traffic engineering and psychology.

He has found that road design-things like placement of speed bumps and the colour and width of paint-combined with the fine movements of pedestrians, drivers, and cyclists, play a remarkably important role in how new cycling infrastructure is used.

Mike includes gaze direction, stance, and the use of objects such as cell phones, car doors, and kerbsides, as important factors that coordinate movement on the road.

"It's not possible to predict exactly which features of infrastructure play a key role in interaction on the road, but a clear finding is that transition points need particular care in their design," Mike told Victoria University's Victorious magazine…

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More than four months after it formed, a large blob of sooty dust from Australia's massive bushfires is still circling the southern hemisphere.

More than four months after it formed, a large blob of sooty dust from Australia's massive bushfires is still circling the southern hemisphere.

NIWA atmospheric scientist Richard Querel says that, unusually, the dust reached high into the stratosphere, where it is still detectable.

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Hundreds of large bushfires raged across the Australian states of New South Wales, Victoria and ACT in December 2019 and January 2020, in a fire season dubbed the Black Summer.

Large smoke plumes travelled across the Tasman to New Zealand, where people could smell the smoke as a dusty haze obscured the sky.

Remarkably, more than four months later, the remains of that smoke is still circling the globe.

Richard works at the world-renowned Lauder Atmospheric Research Station, in Central Otago.

"The whole atmosphere is being measured by a variety of our instruments," says Richard, and some of those instruments, such as lasers and balloons, have been used to monitor the bushfire smoke from the ground. These data complement other data collected from space by various satellites.

"We saw one particular blob come over about 50 days after it left Australia," says Richard. "It went across the Pacific and then came back. And by the time it was over us it was between 25 and 30 kilometres high, whereas originally the fire would have put it to maybe 15 kilometres."

Richard says the dark dust was elevated an extra 10 kilometres by the sun.

"The sun was heating all the carbon aerosol, the soot, that was in this cloud and that's a very unique feature ... All that solar thermal heating slowly heated up the air parcel itself and that slowly rose."

Richard says it just so happened that the material in the smoke cloud was small, light particles which made it buoyant.

"Since the fires were so energetic, it pushed the smoke up and it pierced into the lower stratosphere dehydrated" says Richard.

Round the world in a dust cloud

The blob has now been around the globe several times and the dust has since ascended to twice the original height. "Some of that material is up at 32 to 35 kilometres now."

It is one of the largest plumes of smoke observed by satellites that high in the stratosphere. At its maximum, Richard says the smoke was spread across mid latitudes in the southern hemisphere. "There was pieces and pockets of it everywhere."…

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Dust from Australia's bush fires is still circling the globe in the stratosphere, and studies into cyclists and their use of city streets.

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Wellington naturalist George Vernon Hudson collected thousands of moths and a century later a group of citizen scientists are following in his footsteps in Zealandia sanctuary.

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Modern-day citizen scientists are following in the footsteps of a well-known Wellington naturalist, collecting moths to document a century of change.

A century ago, Wellington naturalist George Vernon Hudson collected thousands of moths in the bush next to his home, in what is now Zealandia sanctuary.

Now a group of citizen scientists are following in his footsteps, collecting moths to see how the numbers and species of moths have changed over time as the local vegetation has changed.

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For nearly six decades, in the late 1800s and early 1900s, Wellington naturalist George Vernon Hudson walked in the bush next to his Karori home two to three nights a week, collecting moths.

He was a keen observer, finding well-camouflaged moths as they sheltered on tree trunks or on leaves.

He beat bushes with a large stick, using a large upside-down white umbrella to catch moths as they tumbled out.

Back home, he painstakingly prepared the specimens, writing tiny identifying labels that he hid under each moth when he pinned it into a specimen box with its wings carefully arranged.

The details of each specimen were entered into a large ledger, carefully coding what it was, and when and where he'd collected it.

Hudson prepared detailed illustrations of many species, which were as artistically beautiful as they were scientifically accurate.

On his death, the insect collection, illustrations and diaries were gifted to New Zealand's National Museum, now Te Papa Tongarewa.

George Vernon Hudson's life work spans 1881-1946 and is the single largest insect collection in New Zealand.

A century later

A hundred years later, George Vernon Hudson's grandson, entomologist George Gibbs, is one of a group of keen citizen scientists following in the moth collector's footsteps.

The 100 Year Moth Project is an Entomological Society project in association with Zealandia sanctuary, which is a short stone's throw from Hudson's moth haunts.

The team assemble in Zealandia once a month at twilight to set up the light trap, which consists of a bright ultraviolet light, powered by a generator and positioned on a white sheet on the ground.

Moths are attracted to the light and settle around it on the sheet. Half a dozen keen spotters identify different species of moths and collect a few examples of each kind, with most moths being left alone.

Crowd sourcing moth identification

William Brockelsby is the organiser of the 100 Year Moth Project, and he says they collect between 20-50 species in a night. The exact species vary from month to month…

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Mathematician Alex James, from Te Pūnaha Matatini & the University of Canterbury, explains the art and science of modelling the coronavirus pandemic.

Since the COVID-19 pandemic began, it would be fair to say that many of us have become obsessed with numbers.

The number of cases of coronavirus, the number of deaths and so on.

Mathematician Associate Professor Alex James is no different - but for her there are some numbers that are more important than others.

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Alex James is a mathematician at the University of Canterbury and an investigator with Te Pūnaha Matatini, New Zealand's Centre of Research Excellence for Complex Systems and Data Analytics.

She is interested in creating mathematical models for what are known as complex systems, including ecology and infectious diseases.

When it came to the coronavirus pandemic, Alex and colleagues at Te Pūnaha Matatini decided to use their collective expertise to model the situation in New Zealand as it developed. They have produced a number of models, which they are providing to health officials to help with decision-making.

These models complement others being worked on by groups such as Michael Baker and Nick Wilson at the University of Otago, amongst others.

The mathematical modelling of a disease such as coronavirus is not about precise predictions.

"We're not always trying to predict exact numbers," says Alex. "We're often thinking 'in two weeks' time is it going to be going up? Is it still going to be going up? Is it going to be going down?' It's more general questions like that rather than what will the number exactly be."

Alex says that she thinks mathematical modelling is both an art and a science.

"The art is to think this is complicated, there are a million different things going on here - but what are the most important ones? Can I boil this down to just two or three ideas and capture a lot of that complexity in just a small number of features."

One magic number

"In epidemiological models, models of disease spread, we have one magic number," says Alex. "We call it R0 or R nought." It is also known as R zero, the reproduction number or reproductive ratio.

"R nought is 'if I have an infection, how many people am I likely to infect'?"

An R0 of two means that on average one person will spread the infection to two others. Anything above one means the number of cases will begin to increase exponentially. An R0 of less than one means the infection will eventually die out…

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Alison Ballance chats with mathematician Alex James, who has been helping model the coronavirus pandemic in New Zealand.

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The human immune system is a complex system where T cells, B cells and antibodies battle invaders such as bacteria and viruses such as the one that causes COVID-19.

Associate Professor Jo Kirman thinks of our immune system as "an orchestra."

"And there's lots of different instruments playing and they all work together to make the music."

The instruments in the immune orchestra have names like phagocytes, T cells and B cells, and together they help the human body repel invaders such as bacteria and viruses, including the new coronavirus that causes COVID-19.

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When we're born, says Jo, we have a very under-developed immune system of our own, with only a small number of instruments. But as babies we're not without protection, because we inherit antibodies and protection from our mother, via the placenta before we're born and through breast milk.

"But then we develop our own orchestra and are able to fight infection," says Jo, who is an immunologist at the University of Otago..

"We've got two arms of the immune system," says Jo. "We've got our innate immune system which is very fast-acting but it's not particularly specific. And then we've got our highly specific adaptive immune system."

The first line of defence against infection, is of course our skin, mucus and ear wax, which prevent microbes gaining entry - but if that fails, then our immune system kicks in.

First responders

The first responders against infection from bacteria and viruses - the paramedics, if you like - are from the innate immune system. "They're there, they're ready," and they respond in a couple of minutes.

Jo says that many of the cells are phagocytes.

"Phagocytic cells like to eat things. They're like the vacuum cleaners of the immune system - they go around sucking things up."

There are a number of different kinds of phagocytes. Macrophages - their name basically means 'big eater' - "gobble up" infected cells or bacterial cells, and then digest and destroy them.

Neutrophils, monocytes and mast cells are also phagocytes, and collectively they are also known as white blood cells or leukocytes.

Good immunity takes time

Jo says the adaptive system is a slower-acting response that can take hours and even days to kick into action. It's the immune equivalent of going to hospital for more complex treatment if the paramedic hasn't been able to solve the problem…

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Immunologist Jo Kirman introduces us to our immune system and how it fights viruses such as the one that causes COVID-19.

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