Going with the throughflow

Hose spraying water

The backyard experiment any hose-owner can try. Image: Flickr / Scott Akerman

By Simon Torok

Here’s a simple backyard science experiment for you to try, which has global implications.

Grab a garden hose, turn it on, and then put your thumb over the end of it. The flow of water thins, while its power intensifies.

Okay, now multiply that by a few million and you have some idea of the impact of recent La Niña conditions on a major ocean current north of Australia.

The Indonesian Throughflow is a series of ocean currents linking the Pacific and Indian Oceans. It carries water from the Pacific to the Indian Ocean through the passages and straits of the Indonesian Archipelago.

Schematic of the ITF. Values of the flow and the major passages are indicated by red. Water enters the ITF from the western Pacific and exits into the Indian Ocean.

Schematic of the ITF. Values of the flow and the major passages are indicated by red. Water enters the ITF from the western Pacific and exits into the Indian Ocean. Image: Wikipedia.

Researchers – led by Janet Sprintall at Scripps Institution of Oceanography in the United States, and including Susan Wijffels from CSIRO in Hobart – have found that the flow of water in the Indonesian Throughflow has become more shallow and intense since the late 2000s due to La Niña conditions, just as the water flow thinned and intensified while you played with that garden hose.

The paper, The Indonesian seas and their role in the coupled ocean-climate system appears in today’s online publication of the journal Nature Geoscience.

The Indonesian Throughflow is the only place in the world where warm equatorial waters flow from one ocean to another; consequently, the throughflow is an important chokepoint in the flow of heat in the climate system.

The paper suggests that human-caused climate change could make this shallowing and intensification a more dominant feature of the Indonesian Throughflow, even under El Niño conditions.

Changes in how much warm water is carried by the Indonesian Throughflow will affect the sea surface temperature, and in turn the patterns of rainfall in our region.

So you may need to think a bit more about how you use that garden hose.


Young guns – our up and coming

Saad SayeefSaad Sayeef – Research Scientist – Energy

When clouds block the sun, solar panels and the electricity networks they are hooked up to need time to adjust to the fluctuations. Saad is working out how to maximise solar efficiency as part of the Energy Networks Team in the CSIRO Energy Flagship. He is looking at various solutions including smart grids, solar energy management and solar “forecasting”.

Beau_Leese

Beau Leese – General Manager – Strategy, Performance and Flagships 

Beau is responsible for the development and implementation of the CSIRO’s overall enterprise strategy, new strategic initiatives, science portfolio investment, planning and performance management, Impact 2020 and cross Flagship collaboration (phew). Beau led CSIRO’s operating model review and the startup phase of the integrated reform program. He is a member of CSIRO’s Executive Management Council, SICOM and Major Transactions Committee.

 

Lisa portraitLisa Harvey-Smith: Research Astronomer – Information Sciences

Lisa is CSIRO’s Project Scientist for the Australian Square Kilometre Array Pathfinder in WA.
The daughter of a Primary School teacher and a house-dad, Lisa left school at the age of 11 and taught herself at home, where her passion for astronomy developed. Her scientific publications span a number of fields from star formation, cosmic magnetic fields and gravitational lensing to supernova remnants. When not designing telescopes and studying galaxies billions of light-years away, she enjoys ultra-long-distance running, including 12 and 24-hour races. In 2012 she was appointed chair of the steering committee of the Women in Astronomy Chapter of the Astronomical Society of Australia.

Nick RodenNick Roden – PhD Student – Environment

Rather than chipping on to the 9th green on the professional golf circuit, Nick Roden is now looking at how different biological and physical processes combine to influence the carbon cycle in the waters around East Antarctica. A few years ago Nick, who is based in Hobart, decided that studying the biology of the waters around East Antarctica as part of a PhD had a brighter future than being a professional golfer, so Nick chucked in the clubs and joined CSIRO. We’re glad he did.

 

Vanessa (Ginny) Hill – Social Media Advisor – Communications

Vanessa Hill + Luna Vanessa is one of the team leading CSIRO into the digital age as far as social media is concerned –video content produced by Vanessa has had more than 13 million views on YouTube. Other platforms such as Twitter and news@CSIRO blog take CSIRO’s and Vanessa’s work to millions more each year.
Even when Vanessa is at home or on holidays – she keeps on tweeting and communicating science.

 

 


Mega-pest worms its way into Brazil

Helicoverpa armigera_5

By Wee Tek Tay, Research Scientist, CSIRO Biosecurity Flagship

We often speak of the risks of new invasions in our increasingly interconnected world, and stress the need for a strong and reliable biosecurity system to safeguard our borders.

As global trading and markets increase, it’s essential to develop our ability to detect incursions using new and innovative surveillance techniques combined with rapid identification capabilities.  This is important because Incursions by exotic pests and diseases have the potential to seriously impact Australia’s people, agricultural industries and unique environment.

And right now, a team of Australian and international scientists are working closely with colleagues in Brazil as one of the most destructive pests known to agriculture – the cotton bollworm (Helicoverpa armigera) – worms its way into Brazilian agricultural fields.

Helicoverpa armigera has long been recognised as a serious biosecurity threat to the Americas, where it has the potential to establish across the South and North American continent with far greater anticipated potential economic loss to corn and cotton than the closely related Helicoverpa zea which is endemic to the Americas.

Incredibly, despite being intercepted at US Ports of Entry a staggering 4431 times since 1985, this mega-pest had not been previously reported to take hold on the American continents.

In Australia, Asia, Africa and Europe, where cotton bollworm is considered native, the damage it causes is estimated to cost $US 2 billion each year. In the last two growing seasons, high infestations of Helicoverpa species larvae were found in different regions of Brazil, resulting in substantial economic losses of up to 10 billion Brazilian Reals ($US 4.4 billion).

A cotton bollworm larvae decimating a cob of corn

A cotton bollworm larvae decimating a cob of corn

At first it was assumed that the damage was being caused by Helicoverpa zea, because the cotton bollworm had never previously been detected within the country. However, as the scale of spread and destruction was monitored, the Brazilian scientists knew that something was different and suspected that maybe the dreaded incursion of Helicoverpa armigera had indeed begun. At this point, Brazilian scientists from the Mato Grosso Cotton Institute approached CSIRO researchers to assist in the careful identification of the species attacking their crops.

Our scientists, together with French and Indian colleagues from CIRAD and IRD in France and the Indian Council of Agricultural Research used evolutionary and population genetics to confirm that the cotton bollworm has now successfully invaded Brazil.

Along with the confirmation that the Brazilians are indeed dealing with a new incursion of a serious exotic pest, the international team led by scientists from the CSIRO Biosecurity Flagship and Matto Grosso Cotton Institute is providing further vital data that will assist Brazil to manage this new menace.

The next steps for the research team are to investigate where the moth originated, where they are currently distributed, its spread across the South American continent, and the incidence of resistance to key pesticides. This information, coupled with CSIRO’s extensive expertise in insecticide resistance management will assist Brazil to develop effective strategies to manage this mega-pest.

You can read the full research paper at PLOS ONE.


For media enquiries contact Emma Pyers: +61 3 5227 5123, emma.pyers@csiro.au


Defending ag from disease

Photo of the exterior of the Australian Animal Health Laboratory

The Australian Animal Health Laboratory in Geelong, Victoria

On-call 24 hours a day, seven days a week, diagnostic scientists at CSIRO are ready to respond should an emergency disease outbreak occur.

They could test 10,000 samples per day in an emergency, but as standard delivery, CSIRO scientists at Australian Animal Health Laboratory (AAHL) in Geelong, Victoria, test more than 45,000 samples for 55 terrestrial and 40 aquatic animal diseases every year.

Luckily, Australia is relatively free of many animal and human diseases found in other parts of the world, such as foot and mouth disease (FMD) and Nipah virus.

However, new infectious diseases, such as new strains of avian influenza, pose a constant threat to the health and wellbeing of animals and humans and pose a risk to Australia’s environment, industries and trade.

According to AAHL’s director Dr Kurt Zuelke, researchers are focused on reducing the threats of exotic and emerging animal diseases and, for example, are on standby with over 650 different tests covering a diverse range of animal species. “AAHL researches diseases of national importance found in livestock, aquaculture animals and wildlife, including those that can pass from animals to people,” Dr Zuelke said. “Our scientists are a front-line defence who help protect the country’s billion dollar livestock and aquaculture industries from disease threats on a daily basis.”

They play this defence role through performing diagnoses, establishing surveillance to monitor movements and emergences and if required, responding to animal disease emergencies. Better understanding diseases to develop diagnostic tests, vaccines and treatments is also crucial and CSIRO AAHL scientists lead the world on bat and insect-borne disease research. This is important for animal and human health as bats and insects are natural reserviours of a range of viruses and cause many of the world’s infectious diseases in both animals and humans.

Malaria and dengue, for example, are harmless to mosquitoes; blue tongue virus is harmless to midges; and Hendra, Nipah, and Severe Acute Respiratory Syndrome (SARS) viruses are harmless to bats – but all can be lethal to humans. AAHL also helps to train veterinarians in other countries to reduce the disease risks to Australia and is an official collaborating centre for capacity building in Southeast Asia. Recently, teams have visited Vietnam, Cambodia and Laos to train local veterinarians in disease diagnosis and testing techniques in their efforts to control and eradicate diseases such as FMD, classical swine fever and avian influenza. Importantly, this international work means Australia is more prepared with better threat assessments, surveillance and management options for many foreign diseases.


This article originally appeared in our 16 May Rural Press insert (pdf).

You can see what else we’ve been up to in our Rural Press Inserts Archive.


Crunchy carrots and fluffy bread – It’s all about the structure

Flickr/stephendl

Flickr/stephendl

By Li Day, Research Group Leader, CSIRO Animal, Food and Health Sciences

It’s a food’s structure that gives a carrot its crunch and a loaf of bread its fluffiness, and researchers increasingly believe that many of a food’s key properties relate to its structure.

Nature is able to assemble sophisticated structures and food is no exception, even right down to the microscopic scale. Food components such as protein, carbohydrate, fat and minor ingredients, when mixed, organise into a range of structures, and its becoming clear that many properties key to a food’s processability, nutritional and sensory qualities, and safety are related to its structure.

Plants are structured like honeycomb, called ‘cell wall’ structure. The video below clearly shows the defined cell walls in raw carrot – that’s why it’s crunchy!

A scanning laser confocal microscope video in 3D showing the defined cell wall structure of raw carrot (Video: Sofia Oeseth)

Most foods have a ‘fluffy’ foam structure that forms when air bubbles are incorporated into a liquid, like bread, ice cream and meringue. The microscopic image below shows dough with air bubbles (black), gluten (yellow), starch granules (green) and protein (red).

Dough under the microscope (Click for full size image)

Dough’s foam structure is full of air (Click for full size image)

Then there are suspensions, which are a bit like oceans, with a sea of solid particles (the ingredients) suspended within a major component that is a liquid (quite often water).  Think tomato paste, fruit juices and some sauces and soups.

Cooked pumpkin in water under the microscope (Click for full size image)

Cooked pumpkin cells suspended in water (Click for full size image)

The next microscopic image shows a suspension in 3D of cooked pumpkin in water. Notice how round the pumpkin cells are – that’s why pumpkin soup feels so smooth and creamy when we’re eating it.

Colloids, which have microscopic particles dispersed through another substance, are another type of structure. Milk is an emulsified colloid of liquid butterfat dispersed in a water-based solution. The third microscopic image is of milk, and the red dots are drops of fat dispersed throughout the liquid whey (black).

Microscopic image of breast milk

Milk has a colloid structure (Click for full size image)

There are other structure types as well – solutions, emulsions and gels, which all behave differently to each other.

The structure of a food affects the way we chew it, how it breaks down in our mouths and our perception of its texture and flavour.  And because each structure also breaks down differently in our digestive system, the release and bioavailability of small molecules such as minerals, vitamins and polyphenols is also different.

Because of all these factors, food structures are increasingly being recognised as important in technology innovation for the development of healthier foods.

And as there is increasing awareness that structure has a significant effect on the bio-availability of nutrients, the focus of developing nutritional guidelines is shifting away from the traditional approach of simply assessing the nutrient composition of foods.


CSIRO is hosting the Food Structures, Digestion and Health Conference on 21 – 24 October, which will discuss the role of structure in designing foods for nutrition and wellbeing.


Emerging tech creating a safer food chain

iStock_000021161362XLarge

By Mala Gamage and Kai Knoerzer

In recent years a number of emerging or new food processing technologies have been investigated, developed and to some extent implemented, with the aim of improving or replacing conventional processing technologies.

By reducing pathogens and invasive species from food products, these technologies have great potential for the treatment of products exported interstate or overseas, opening the doors for wider export markets.

Because they take advantage of different applications and gentler processing methods, they also often result in processed food with a ‘fresh-like’ quality.

And while they all use vastly different techniques, they’re all pretty impressive.

Photo of sesame seeds being subjected to cool plasma

Are these sesame seeds cooler now after a dose of plasma?

Cool plasma

Cool plasma isn’t only cool in temperature, it’s cool science.

Plasma is also known as the fourth state of matter (as well as solid, liquid and gas) and exists when the internal energy of a gas is increased to a state where the gas molecules become ionised.  This plasma phase contains a number of reactive species, such as ions, free radicals and also UV radiation, which are all effective in killing bacteria, fungal spores and insects, and can be used to inactivate pests on the product surface.

Photo of a Pilot-scale continuous, pentagonal Microwave tunnel

A continuous pentagonal microwave tunnel (including convection heating facilities) at our Food Manufacturing pilot plant in Werribee, Victoria.

Microwave Processing

Large scale microwaves are actually very similar to the microwave ovens most of us have at home, but usually have a higher power capacity, and conveying systems to transport products through a microwave tunnel, where they are heated with an electromagnetic field.

Microwave processing has recently been used to disinfest (inactivate insect pests) fresh food such as apples, capsicums, zucchinis and avocados, while maintaining the quality and freshness of the product.

The microwave technology also has great potential for the disinfestation of grains.

The effect of high pressure on bugs

The effect of high pressure on bugs

High Pressure Processing

Imagine 200 elephants, each weighing three tons, standing on a piston the size of a CD. That’s greater pressure than at the deepest point of the ocean, and is the amount of pressure that products face during High Pressure Processing (HPP).

The products are packed into tight vessels and subjected to pressures up to 600 MPa, or 6000 bars.

And while you might think that would crush the products, they actually only compress by about 20 per cent, although that’s enough to kill any bacteria and insects present.

And by the end of the process, the product usually finishes at the same size it started.

Photo of a collapsing cavitation bubble

A collapsing cavitation bubble

Ultrasound

Ultrasound is nothing but sound, but at a frequency so high that it can’t be heard by people.

It’s generated by vibrating plates (at 20,000 vibrations per second or higher) which leads to the formation of water vapour bubbles, called cavitation bubbles.

Once they exceed a certain size the bubbles violently collapse, creating very high pressures, temperatures and streaming. These harsh conditions can be used to get rid of pests from product surfaces, as well as cracks and crevices.

A schematic representation of electrons activating on the surface of pecan nuts. Or...pecan nuts covered with a lot of e-'s

A schematic representation of electrons activating on the surface of pecan nuts. Or…pecan nuts covered with a lot of ‘e-‘s

Low Energy Electron Beams

Electron beams inactivate bacteria, spores, fungi and insects through ionisation of the molecules in the pest.

The technology is actually very similar to the old, bulky tube TVs, where electrons are released from a hot electrode and accelerated and guided by magnetic fields onto the TV screen. Instead of the TV screen, the electron beam is guided onto the surface of a product.

Similar to cool plasma, it’s mainly effective on product surfaces, but can also penetrate to depths up to 1mm.

The technology is gaining traction in Germany for the organic treatment of grain seeds, where it completely inactivates pests without negatively affecting germination of the seeds.


About the Authors

Photo of Mala GamageDr Mala Gamage, Research Project Leader, CSIRO Animal, Food and Health Sciences

Mala has initiated research on the identification of innovative technological solutions for insect disinfestation in horticultural commodities, and evaluated the feasibility of using ultrasound, high pressure and microwave for the disinfestation of fruit flies.


Kai KnoerzerDr Kai Knoerzer, Research Project Leader, CSIRO Animal, Food and Health Sciences

Kai is working to enhance the nutritional value, convenience and quality attributes (such as fresh taste, colour etc) of processed foods through innovative food processing technologies, including high pressure, pulsed electric fields, microwave, ultrasound, and cool plasma processing.


Friday Fish Time

Common name: Blue Marlin. Scientific name: Makaira nigricans. Family: Istiophoridae.

Common name: Blue Marlin. Scientific name: Makaira nigricans.
Family: Istiophoridae.

Blue Marlin: This week a blue marlin washed up on a suburban Adelaide beach. It is thought this is the first time a marlin has been found in the cool waters of Gulf St Vincent where Adelaide sits.

Scientists from the South Australian Research and Development Institute think the fish took a wrong turn at Kangaroo Island and ended up in the Gulf.

They also think that the 3.2m long, 250kg marlin swan along the WA and SA coasts in the warm Leeuwin Current which at this time of year flows down the WA coast and around into the Great Australian Bight.

Below is a picture of the current (red turning to yellow and green as it cools) whipping around the bottom of WA. The second image shows the SA coast with the relatively warm water flowing around Kangaroo Island.

More images of the ocean currents around Australia can be found at the Bureau of Meteorology site which gets the information through the Bluelink program  run by CSIRO’s Wealth from Oceans Flagship in collaboration with the Bureau of Meteorology and the Royal Australian Navy.

Current

current2

Anyway, back to the blue marlin. There is a debate going on about the classification of the Atlantic blue marlin and the

Indo-Pacific blue marlin (Makaira mazara) as separate species. Genetic data seems to show that although the two groups are isolated from each other they are both the same.

The blue marlin spends most of its life in the open sea far from land and preys on a wide variety of marine life and often uses its long bill to stun or injure its prey.

Females can grow up to four times the weight of males and the maximum published weight is 818kg and 5m long.

Blue marlin, like other billfish can rapidly change color, an effect created by pigment-containing iridophores and light-reflecting skin cells. Mostly they have a blue-black body on top with a silvery white underside.

Females can spawn up to four times in one season and release over seven million eggs at once. Males may live for 18 years, and females up to 27.

National Parks and Wildlife officer Josh Edwards and PIRSA aquatic health officer Dr Shane Roberts help to transport the blue marlin found on Carrickalinga beach. Pic: SARDI

National Parks and Wildlife officer Josh Edwards and PIRSA aquatic health officer Dr Shane Roberts help to transport the blue marlin found on Carrickalinga beach this week.
Pic: SARDI


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