Tag Archives: University of Warwick

Does the universe have a heartbeat?

It may be a bit fanciful to suggest the universe has a heartbeat but if University of Warwick (UK) researchers can state that dying stars have ‘irregular heartbeats’ then why can’t the universe have a heartbeat of sorts? Getting back to the University of Warwick, their August 26, 2015 press release (also on EurekAlert) has this to say,

Some dying stars suffer from ‘irregular heartbeats’, research led by astronomers at the University of Warwick has discovered.

The research confirms rapid brightening events in otherwise normal pulsating white dwarfs, which are stars in the final stage of their life cycles.

In addition to the regular rhythm from pulsations they expected on the white dwarf PG1149+057, which cause the star to get a few percent brighter and fainter every few minutes, the researchers also observed something completely unexpected every few days: arrhythmic, massive outbursts, which broke the star’s regular pulse and significantly heated up its surface for many hours.

The discovery was made possible by using the planet-hunting spacecraft Kepler, which stares unblinkingly at a small patch of sky, uninterrupted by clouds or sunrises.

Led by Dr JJ Hermes of the University of Warwick’s Astrophysics Group, the astronomers targeted the Kepler spacecraft on a specific star in the constellation Virgo, PG1149+057, which is roughly 120 light years from Earth.

Dr Hermes explains:

“We have essentially found rogue waves in a pulsating star, akin to ‘irregular heartbeats’. These were truly a surprise to see: we have been watching pulsating white dwarfs for more than 50 years now from the ground, and only by being able to stare uninterrupted for months from space have we been able to catch these events.”

The star with the irregular beat, PG1149+057, is a pulsating white dwarf, which is the burnt-out core of an evolved star, an extremely dense star which is almost entirely made up of carbon and oxygen. Our Sun will eventually become a white dwarf in more than six billion years, after it runs out of its nuclear fuel.

White dwarfs have been known to pulsate for decades, and some are exceptional clocks, with pulsations that have kept nearly perfect time for more than 40 years. Pulsations are believed to be a naturally occurring stage when a white dwarf reaches the right temperature to generate a mix of partially ionized hydrogen atoms at its surface.

That mix of excited atoms can store up and then release energy, causing the star to resonate with pulsations characteristically every few minutes. Astronomers can use the regular periods of these pulsations just like seismologists use earthquakes on Earth, to see below the surface of the star into its exotic interior. This was why astronomers targeted PG1149+057 with Kepler, hoping to learn more about its dense core. In the process, they caught a new glimpse at these unexpected outbursts.

“These are highly energetic events, which can raise the star’s overall brightness by more than 15% and its overall temperature by more than 750 degrees in a matter of an hour,” said Dr Hermes. “For context, the Sun will only increase in overall brightness by about 1% over the next 100 million years.”

Interestingly, this is not the only white dwarf to show an irregular pulse. Recently, the Kepler spacecraft witnessed the first example of these strange outbursts while studying another white dwarf, KIC 4552982, which was observed from space for more than 2.5 years.

There is a narrow range of surface temperatures where pulsations can be excited in white dwarfs, and so far irregularities have only been seen in the coolest of those that pulsate. Thus, these irregular outbursts may not be just an oddity; they have the potential to change the way astronomers understand how pulsations, the regular heartbeats, ultimately cease in white dwarfs.

“The theory of stellar pulsations has long failed to explain why pulsations in white dwarfs stop at the temperature we observe them to,” argues Keaton Bell of the University of Texas at Austin, who analysed the first pulsating white dwarf to show an irregular heartbeat, KIC 4552982. “That both stars exhibiting this new outburst phenomenon are right at the temperature where pulsations shut down suggests that the outbursts could be the key to revealing the missing physics in our pulsation theory.”

Astronomers are still trying to settle on an explanation for these never-before-seen outbursts. Given the similarity between the first two stars to show this behaviour, they suspect it might have to do with how the pulsation waves interact with themselves, perhaps via a resonance.

“Ultimately, this may be a new type of nonlinear behaviour that is triggered when the amplitude of a pulsation passes a certain threshold, perhaps similar to rogue waves on the open seas here on Earth, which are massive, spontaneous waves that can be many times larger than average surface waves,” said Dr Hermes. “Still, this is a fresh discovery from observations, and there may be more to these irregular stellar heartbeats than we can imagine yet.”

Here’s a link to and a citation for the paper,

A Second Case of Outbursts in a Pulsating White Dwarf Observed by Kepler by J. J. Hermes, M. H. Montgomery, Keaton J. Bell, P. Chote, B. T. Gänsicke, Steven D. Kawaler, J. C. Clemens, Bart H. Dunlap, D. E. Winget, and D. J. Armstrong.
2015 ApJ 810 L5 (The Astrophysical Journal Letters Volume 810 Number 1). doi:10.1088/2041-8205/810/1/L5
Published 24 August 2015.

© 2015. The American Astronomical Society. All rights reserved.

This paper is behind a paywall but there is an earlier open access version available at arXiv.org,

A second case of outbursts in a pulsating white dwarf observed by Kepler by J. J. Hermes, M. H. Montgomery, Keaton J. Bell, P. Chote, B. T. Gaensicke, Steven D. Kawaler, J. C. Clemens, B. H. Dunlap, D. E. Winget, D. J. Armstrong.  arXiv.org > astro-ph > arXiv:1507.06319

In an attempt to find some live heart beats to illustrate this piece, I found this video from Wake Forest University’s body-on-a-chip program,

The video was released in an April 14, 2015 article by Joe Bargmann for Popular Mechanics,

A groundbreaking program has converted human skin cells into a network of functioning heart cells, and also fused them with lab-grown liver cells using a specialized 3D printer. Researchers at the Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine provided Popular Mechanics with both still and moving images of the cells for a fascinating first look.

“The heart organoid beats because it contains specialized cardiac cells and because those cells are receiving the correct environmental cues,” says Ivy Mead, a Wake Forest graduate student and member of the research team. “We give them a special medium and keep them at the same temperature as the human body, and that makes them beat. We can also stimulate the miniature organ with electrical or chemical cues to alter the beating patterns. Also, when we grow them in three-dimensions it allows for them to interact with each other more easily, as they would in the human body.”

If you’re interested in body-on-a-chip projects, I have several stories here (suggestion: use body-on-a-chip as your search term in the blog search engine) and I encourage you to read Bargmann’s story in its entirety (the video no longer seems to be embedded there).

One final comment, there seems to be some interest in relating large systems to smaller ones. For example, humans and other animals along with white dwarf stars have heartbeats (as in this story) and patterns in a gold nanoparticle of 133 atoms resemble the Milky Way (my April 14, 2015 posting titled: Nature’s patterns reflected in gold nanoparticles).

Nanocrystallometry points the way to control of motion in the nano-world

A May 28, 2014 news item on Azonano describes a new technique that could lead to controlling the growth of metal oxide crystals,

Published in the journal Nature Communications and developed at the University of Warwick, the method, called Nanocrystallometry, allows for the creation of precise components for use in nanotechnology.

Professor Peter Sadler from the University’s [University of Warwick] Department of Chemistry commented that “The breakthrough with Nanocrystallometry is that it actually allows us to observe and directly control the nano-world in motion”.

A May ??, 2014 University of Warwick news release, which originated the news item provides more details about the technique (Note: A link has been removed),

Using a doped-graphene matrix to slow down and then trap atoms of the precious metal osmium the researchers were able to control and quantify the growth of metal-crystals. When the trapped atoms come into contact with further osmium atoms they bind together, eventually growing into 3D metal-crystals.

“Tailoring nanoscopic objects is of enormous importance for the production of the materials of the future”, says Dr Nicholas Barry from the University’s Department of Chemistry. “Until now the formation of metal nanocrystals, which are essential to those future materials, could not be controlled with precision at the level of individual atoms, under mild and accessible conditions.”

Prof. Sadler says: “Nanocrystallometry’s significance is that it has made it possible to grow with precision metal-crystals which can be as small as only 0.00000015cm, or 15 ångström, wide. If a nanodevice requires a million osmium atoms then from 1 gram of osmium we can make about 400 thousand devices for every person on this earth. Compared to existing methods of crystal growth Nanocrystallometry offers a significant improvement in the economic and efficient manufacture of precision nanoscopic objects.”

The researchers argue that the new method possesses a range of potential uses. “We envision the use Nanocrystallometry to build precise, atomic-level electronic circuits and new nano-information storage devices. The method also has significant potential for use in the biosensing of drugs, DNA and gases as well for creating unique nano-patterns on surfaces for security labelling and sealing confidential documents. Nanocrystallometry is also an innovative method for producing new metal nano-alloys, and many combinations can be envisaged. They may have very unusual and as yet unexplored properties”, commented Dr Barry.

Here’s a link to and a citation for the research paper,

Fabrication of crystals from single metal atoms by Nicolas P. E. Barry, Anaïs Pitto-Barry, Ana M. Sanchez, Andrew P. Dove, Richard J. Procter, Joan J. Soldevila-Barreda, Nigel Kirby, Ian Hands-Portman, Corinne J. Smith, Rachel K. O’Reilly, Richard Beanland, & Peter J. Sadler. Nature Communications 5, Article number: 3851 doi:10.1038/ncomms4851 Published 27 May 2014

This is an open access paper.

Phytoremediation, clearing pollutants from industrial lands, could also be called phyto-mining

The University of Edinburgh (along with the Universities of Warwick and Birmingham, Newcastle University and Cranfield University) according to its Mar. 4, 2013 news release on EurekAlert is involved in a phytoremediation project,

Common garden plants are to be used to clean polluted land, with the extracted poisons being used to produce car parts and aid medical research.

Scientists will use plants such as alyssum, pteridaceae and a type of mustard called sinapi to soak up metals from land previously occupied by factories, mines and landfill sites.

Dangerous levels of metals such as arsenic and platinum, which can lurk in the ground and can cause harm to people and animals, will be extracted using a natural process known as phytoremediation.

A Mar. 4, 2013 news item on the BBC News Edinburgh, Fife and East Scotland site offers more details about the project and the technology,

A team of researchers from the Universities of Edinburgh, Warwick, Birmingham, Newcastle and Cranfield has developed a way of extracting the chemicals through a process called phytoremediation, and are testing its effectiveness.

Once the plants have drawn contaminated material out of the soil, they will be harvested and processed in a bio-refinery.

A specially designed bacteria will be added to the waste to transform the toxic metal ions into metallic nanoparticles.

The team said these tiny particles could then be used to develop cancer treatments, and could also be used to make catalytic converters for cars.

Dr Louise Horsfall, of Edinburgh’s University’s school of biological sciences, said: “Land is a finite resource. As the world’s population grows along with the associated demand for food and shelter, we believe that it is worth decontaminating land to unlock vast areas for better food security and housing.

“I hope to use synthetic biology to enable bacteria to produce high value nanoparticles and thereby help make land decontamination financially viable.”

The research team said the land where phytoremediation was used would also be cleared of chemicals, meaning it could be reused for new building projects.

In my Sept. 28, 2012 posting I featured an international collaboration between universities in the UK, US, Canada, and New Zealand in a ‘phyto-mining’ project bearing some resemblance to this newly announced project. In that project, announced in Fall 2012, scientists were studying how they might remove platinum for reuse from plants near the tailings of mines.

I do have one other posting about phytoremediation. I featured a previously published piece by Joe Martin in a two-part series on the topic plant (phyto) and nano soil remediation. The March 30, 2012 posting is part one, which focuses on the role of plants in soil remediation.

Phyto-mining and environmental remediation flower in the United Kingdom

Researchers on a £3 million research programme called “Cleaning Land for Wealth” (CL4W) are confident they’ll be able to use flowers and plants to clean soil of poisonous materials (environmental remediation) and to recover platinum (phyto-mining). From the Nov. 21, 2012 news item on Nanowerk,

A consortium of researchers led by WMG (Warwick Manufacturing Group) at the University of Warwick are to embark on a £3 million research programme called “Cleaning Land for Wealth” (CL4W), that will use a common class of flower to restore poisoned soils while at the same time producing perfectly sized and shaped nano sized platinum and arsenic nanoparticles for use in catalytic convertors, cancer treatments and a range of other applications.

The Nov. 20, 2012 University of Warwick news release, which originated the news item, describes both how CL4W came together and how it produced an unintended project benefit,

A “Sandpit” exercise organised by the Engineering and Physical Sciences Research Council (EPSRC) allowed researchers from WMG (Warwick Manufacturing group) at the University of Warwick, Newcastle University, The University of Birmingham, Cranfield University and the University of Edinburgh to come together and share technologies and skills to come up with an innovative multidisciplinary research project that could help solve major technological and environmental challenges.

The researchers pooled their knowledge of how to use plants and bacteria to soak up particular elements and chemicals and how to subsequently harvest, process and collect that material. They have devised an approach to demonstrate the feasibility in which they are confident that they can use common classes of flower and plants (such as Alyssum), to remove poisonous chemicals such as arsenic and platinum from polluted land and water courses potentially allowing that land to be reclaimed and reused.

That in itself would be a significant achievement, but as the sandpit progressed the researchers found that jointly they had the knowledge to achieve much more than just cleaning up the land.

As lead researcher on the project Professor Kerry Kirwan from WMG at the University of Warwick explained:

“The processes we are developing will not only remove poisons such as arsenic and platinum from contaminated land and water courses, we are also confident that we can develop suitable biology and biorefining processes (or biofactories as we are calling them) that can tailor the shapes and sizes of the metallic nanoparticles they will make. This would give manufacturers of catalytic convertors, developers of cancer treatments and other applicable technologies exactly the right shape, size and functionality they need without subsequent refinement. We are also expecting to recover other high value materials such as fine chemicals, pharmaceuticals, anti-oxidants etc. from the crops during the same biorefining process.”

I last mentioned phyto-mining in my Sept. 26, 2012 post with regard to an international project being led by researchers at the University of York (UK).  The biorefining processes (biofactories) mentioned by Kirwan takes the idea of recovering platinum, etc. one step beyond phyto-mining recovery.

Here’s a picture of the flower (Alyssum) mentioned in the news release,

Alyssum montanum photographed by myself in 1988, Unterfranken, Germany [http://en.wikipedia.org/wiki/Alyssum]

From the Wikipedia essay (Note: I have removed links],

Alyssum is a genus of about 100–170 species of flowering plants in the family Brassicaceae, native to Europe, Asia, and northern Africa, with the highest species diversity in the Mediterranean region. The genus comprises annual and perennial herbaceous plants or (rarely) small shrubs, growing to 10–100 cm tall, with oblong-oval leaves and yellow or white flowers (pink to purple in a few species).