Destroying tumors with gold nanoparticles

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Section of a tumor observed with an optical microscope. The two white forms with brown borders are blood vessels. Inside, gold nanoparticles accumulate against their walls.
Mariana Varna-Pannerec (ESPCI), Author provided

By Emmanuel Fort, ESPCI Paris

Gold has extraordinary properties. It can be used to make jewelry, but also to fight cancer. Several clinical trials are currently underway in the United States where patients are being treated with gold nanoparticles.

In its natural state, gold is a yellow, chemically inert, non-corrodible metal, making it a noble material that does not degrade over time. These properties, along with the ease with which it can be shaped, have made it the favourite metal of jewellers.

On a nano-metric scale – that is, at a millionth of a meter – gold has other remarkable properties. On this scale, gold particles take on various colours according to their shape and size. This property has been used since ancient times to colour glass and earthenware – giving them, for example, an intense ruby hue. When light is shone on gold nanoparticles, the metal’s conduction electrons are excited by the light wave and begin to oscillate. This oscillation is particularly intense for a given colour in the light spectrum. This is called resonance.

The Roman cup of Lycurgue, from the 4th century. When illuminated from the inside, a beautiful ruby colour appears, coming from the gold and silver nanoparticles contained in the glass.
Trustees of the British Museum
Here the same cup, without interior lighting.
Trustees of the British Museum., CC BY-NC-SA

By changing the shape or size of the nanoparticles, it is possible to choose the resonance frequency that has the strongest interaction with light. The nanoparticles then behave like tiny, highly effective antennae, and although they are extremely small and highly diluted they can give vibrant colours to stained glass.

One incidental consequence of this intense interaction with light is that nanoparticles heat up. This remarkable property is the reason behind their use in new cancer therapies. The idea is to destroy the tumours with photothermia – in other words, to locally heat up tumours “decorated” with gold nanoparticles by exposing them to light.

Patients being treated this way are first injected with gold nanoparticles into their bloodstream through an IV. Since gold is biocompatible, it presents no apparent danger to health in the concentrations used in therapy, as borne out by our studies in mice. However, not all questions have been resolved concerning these new applications. Gold nanoparticles go undetected by the body’s immune defence system. Their nanometric scale means they are generally one hundred times smaller than cells, allowing them to move freely through the blood system and enter the tumour.

They must then be concentrated inside the tumours, many of which are highly vascularized – they naturally acquire a network of blood vessels allowing them to grow. Using this pathway, the nanoparticles easily accumulate inside the tumour. The altered structure of the blood vessels in the tumour area makes them more permeable, facilitating a high retention of nanoparticles.

Tumours “decorated” with gold nanoparticles are then exposed to light, in order for them to heat up and be destroyed. At this stage, the challenge is twofold. While the light must penetrate the body and reach the tumour, healthy tissue must not be heated. The choice of frequency is therefore vital. Nanoparticles must be lit up at their resonance frequency, but it is just as essential that the tissues without nanoparticles not absorb the light.

While our bodies absorb light in the visible part of the light spectrum (that is, all the colours of the rainbow), this is not the case in the near infrared. We can see this by simply placing a hand over an intense white light. Only the colour red, on the edge of infrared, can move through the flesh of the hand.

This range of the spectrum in the near infrared is often called the “therapeutic window” – the range that can be used in medical treatment. In the visible spectrum, light is mainly absorbed by hemoglobin, while light further into infrared range is absorbed by the water contained in our bodies.

Gold nanoparticles are injected into a mouse carrying a tumour. Five hours later, sections of the tumour are examined through an optical microscope (centre). We can see the gold nanoparticles
Mariana Varna-Pannerec (ESPCI), Author provided

Nanoparticles with specific shapes

By playing with the shape of nanoparticles, it is possible to adjust their resonance so as to target the near infrared therapeutic window. This is carried out, for example, for nanoparticles with a silica core and a gold shell, for gold nanorods, or for nano-cages shaped like porous cubes. Preclinical studies (in animals) have enabled us to test the safety and effectiveness of various shapes of nanoparticles.

In the therapeutic spectrum, light goes through our bodies, but our bodies are not totally transparent to it. The light that comes out the other side is still highly diffused by the body’s tissues. For instance, one cannot see bones in this way, as you would with an X-ray. It is also very difficult to focus a beam of light on a tumour from outside the body, since the light must travel through healthy tissue to reach it.

It is therefore usual (in animal studies) to light up tumours more closely, by inserting a needle through the skin, attached to an optical fibre linked to an infrared laser. The light is then far more intense in the relevant area.

Studies underway on head and neck cancers

Under the light, the gold nanoparticles heat up and “cook” the tumour, thus destroying nearby cancerous cells. Extensive studies have been carried out in animal models on cancers in the brain, prostate and pancreas, for example. Clinical trials are also underway in the United States in patients affected by treatment-resistant head- and neck cancers, and lung- and prostate cancers using AuroLase therapy (Nanospectra Bioscience).

Alternatively, nanoparticles can be used not as a direct weapon against the tumour but as a means of transport (called a vector) to deliver molecules – drugs, for instance – to their destination. This technique requires less heating. The use of vectors should reduce the toxicity of treatments by better targeting cancerous cells.

The Trojan horse strategy

It is possible to increase the number of gold nanoparticles entering a tumour, above and beyond the effect of simple passive accumulation. They perform better when covered with molecules (antibodies) that specifically attach to cancerous cells, which they recognize through the proteins present on the cell membrane. Other alternative techniques adopt a “Trojan horse” strategy. These use a kind of white blood cell, called microphages, filled with gold nanoparticles in order to penetrate more deeply into the tumour.

Gold nanoparticle photothermia is a promising new therapy in cancer treatment. It has begun to be used experimentally in patients with certain specific cancers, but much research is still necessary before it can be adopted more widely. In the future, the technique will have to target the tumour more effectively and exclusively. With thriving research, this therapy should be available, alongside existing treatments like radiotherapy and chemotherapy, in a few years’ time.

Created in 2007, the Axa Research Fund supports more than 500 projects worldwide led by researchers of 51 nationalities. Discover the work of Emmanuel Fort and his Axa ESPCI chair in biomedical imaging as part of the Axa Research Fund.

The ConversationTranslated from the French by Alice Heathwood for Fast for Word

Emmanuel Fort, Professeur de ESPCI Paris, Chaire AXA imagerie biomédicale, membre de l’Institut Langevin, spécialiste de l’interaction onde-matière, ESPCI Paris

This article was originally published on The Conversation. Read the original article.

Male dolphins use their individual ‘names’ to build a complex social network

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Three allied male dolphins in Shark Bay, Western Australia.
Simon J Allen, Author provided

By Stephanie King, University of Western Australia

In life it often pays to keep a close eye on competitors and rivals. Historian Doris Kearns Goodwin’s book, Team of Rivals, tells how US president Abraham Lincoln persuaded each of his political rivals to join his cabinet, thereby turning them into his allies.

But the formation of alliances with potential competitors is not unique to humans. In a study published in Current Biology, my colleagues and I describe how such behaviour is also found among bottlenose dolphins.

We found that individual male dolphins retain their unique signature whistle, allowing them to recognise many different friends and rivals in their social network, something not currently known from any other non-human animal.

Read more:
Tackling the kraken: unique dolphin strategy delivers dangerous octopus for dinner

The Shark Bay network

In Shark Bay, Western Australia, pairs and trios of unrelated male dolphins work together in alliances to herd single females for mating opportunities. On a second level, teams of alliances work together to steal females from opposing alliances and to defend against such theft attempts.

A trio of allied male bottlenose dolphins (Tursiops aduncus) from Shark Bay, Western Australia.
Simon J Allen

The males are therefore cooperating with individuals with whom they are in direct reproductive competition, since paternity success cannot be shared. But the bonds between these teams of rivals are as strong as those between mothers and calves, and these friendships and alliances can last entire lifetimes.

So how do these males keep track of all these different relationships, and how do they maintain such strong social bonds? The answer may lie closer to home than you think.

Vocal labels for dolphins

Previous research has shown that bottlenose dolphins develop an individual vocal label known as their signature whistle, which they use to broadcast their identity.

A bottlenose dolphin signature whistle.
Stephanie L King

Bottlenose dolphin signature whistle.
Stephanie L King, Author provided629 KB (download)

These dolphins aren’t born with their own signature whistle. Rather, each dolphin develops a signature whistle within the first few months of life that is structurally unique from those of its companions.

It has been shown that these signature whistles are somewhat comparable to human names. Dolphins use them to introduce themselves or even copy others as a means of addressing specific individuals.

For decades it was thought that male dolphins would converge onto a shared signature whistle when they formed alliances with one another.

It was proposed that such an alliance signature would allow males to advertise alliance membership to competing males or to sexually receptive females. A type of vocal badge or group label.

Intriguingly, we found that male dolphins in Shark Bay retain individual vocal labels distinct from their allies.

Signature whistles of two different male dolphins from Shark Bay, Western Australia.
Stephanie L King

Male dolphin signature whistles.
Stephanie L King, Author provided485 KB (download)

Individually ‘named’ dolphins

This is an unexpected finding as it is well known that animals that form strong social bonds will vocally accommodate one another, making their calls more similar. By doing so, animals are not only advertising the strength of their relationships but also their group membership.

Such vocal convergence is found in many animals including parrots, songbirds, bats, elephants and primates.

Yet, it appears that in the complex network of dolphin alliances in Shark Bay, retaining individual “names” is more important than sharing calls. It allows male dolphins to recognise many different friends and rivals in their social network.

Even within these dolphin alliances males can show preferences and avoidances for with whom they cooperate.

Bottlenose dolphins have been shown to remember the signature whistles of other individuals even after 20 years of separation. This long-term social memory combined with the use of individual vocal labels, allows dolphins to keep track of many different relationships, as well as the history of those relationships.

Our research suggests that vocal labels play a central role in the recognition of cooperative partners and competitors in biological markets.

Male bonding, dolphin style

If allied male dolphins do not converge onto similar calls, then how do they reinforce their strong bonds?

Well, males in Shark Bay invest a lot of time in gentle contact behaviours, such as petting.

Drone footage shows a trio of adult male dolphins that spend time petting each other, using pectoral fins and tail flukes to rub against each other.

This may be similar to grooming behaviour in primates, which has been linked to oxytocin release. Oxytocin is a hormone that is known to facilitate social bonding between both humans and non-human animals, as well as promoting both trust and cooperation.

Dolphin alliances in Shark Bay are also characterised by high levels of synchronous behaviour. Males in alliances can perform the same behaviours at exactly the same time, surfacing in precise synchrony or performing coordinated displays.

It appears that synchrony, rather than shared calls, is what represents alliance unity.

Read more:
Tourism puts dolphins at risk in Southeast Asia – here’s what to look for on your next holiday

In human societies, synchronous behaviour, such as choreographed dancing, military marching or parades, is believed to have evolved to signal the quality of relationships.

The ConversationIt appears, then, that the multi-level dolphin alliances in Shark Bay share some traits with humans societies, where individual vocal labels help with the recognition of cooperative partners, and synchrony is a signal indicating the strength of those partnerships.

A trio of male dolphins from Shark Bay, Western Australia, synchronously push a female put of the water.
Stephanie L King

Stephanie King, Branco Weiss Research Fellow, University of Western Australia

This article was originally published on The Conversation. Read the original article.

The hunt for life on Mars: new findings on rock ‘chimneys’ could hold key to success

By Alexander Brasier, University of Aberdeen; David Wacey, University of Western Australia, and Mike Rogerson, University of Hull

The search for life on Mars has taken a step forward with the NASA Curiosity rover’s discovery of organic matter on the bottom of what was once a lake. It may once have been part of an alien life form or it might have a non-biological origin – either way this carbon would have provided a food source for any organic living thing in the vicinity.

The discovery adds extra intrigue to NASA’s search for extra-terrestrial life forms themselves. When hunting remotely with one car-sized machine, the question is where best to focus your efforts. It makes sense to look for the same types of places we expect to find fossilised microorganisms on Earth. This is complicated by the fact that these fossils are measured in microns – mere millionths of a metre.

The Curiosity rover looks for certain sedimentary rocks deposited near water, as it did for the latest discovery. This is based on the latest geological advice about the best prospects. Yet which rocks to prioritise is still a matter of some debate – and it’s a question that is just as relevant to geologists trying to unlock the secrets of our own ancient world. The Earth’s rocks and fossils are the nearest thing we have to time machines.

For a century or so, geologists focused on a type of rock called a stromatolite – devoting long hours to crawling around in awkward spaces trying to find them. Stromatolites occur mainly in shallow water and are layered on a millimetre scale. Many of them are undoubtedly built by slimy microbial “biofilms”, but to cut a long story short we now appreciate there is more than one way to make a stripy rock – and they don’t all involve microbes.

Stromatolite city.
Mike Beauregard, CC BY-SA

More recently geologists have become more interested in other types of rocks, including the “black smoker” tube-type deposits formed by hot hydrothermal water being squeezed out of the Earth’s crust in the deep sea. Slightly easier to examine are similar chimney-like formations found in certain alkaline lakes around the world.

Mono Lake

One place on Earth where these chimneys occur is Mono Lake in California, a vast and beautiful stretch of water several hundred miles north of Los Angeles on the eastern slope of the Sierra Nevada mountains. In October 2014, our team obtained permission from the California State Parks to examine and sample some of the calcium carbonate chimneys that have formed there.

The rocks, which are frequently between two and three metres tall, are very young in geological terms, usually only tens of thousands of years old. But since first being described by the famous American geologist Israel Russell in 1889 they have proven an excellent natural laboratory for groups of scientists trying to understand how these structures came about.

Exploration begins.
Alexander Brasier

Before our visit, geologists were essentially divided about these chimneys. A group we might call “pure geochemists” proposed they were nothing to do with microbes, but produced by calcium-rich spring waters coming into contact with the alkaline lake, with its abundance of carbonate ions.

A smaller opposing camp agreed it should be possible for these structures to emerge in the way that pure geochemists were suggesting. But they pointed out that, in the few recorded observations of carbonate rocks forming at the lake in the 19th and 20th centuries, some kind of biofilm did appear to have an influence. They also cited other studies that had shown that waterborne microbes called cyanobacteria did produce slimy substances that can accumulate calcium.

We went to Mono Lake to find out who was right. Our six-strong expedition divided into two factions: one looked for chimneys on the lake bottom using a research boat, while the other explored the famous “tufa towers” that rise up from the lake shore.

Tufa towers on the shoreline.
Alexander Brasier

The boat party toiled and cursed the astonishingly salty waters of the lake, while the shore party made steady progress with the invaluable assistance of local state park ranger, Dave Marquart. Their peace was interrupted only by a phone call from the stranded boaters requesting they urgently try to find someone with a four-wheel drive capable of pulling the boat back out of the water – luckily help was at hand.

One of the sites the shore party visited was in Marquart’s own back garden to the north-west of the lake. The rocks there were part of a set of ancient chimneys formed along a small tectonic fault. Their features suggested they had been built by microbes, but we needed to send them to a lab to be sure.

Microbial ‘threads’

Using an optical microscope, we were able to see dark thread-like structures entombed in slices of the rock. As we outline in our new study published in Geobiology, these “threads” are millions of fossilised photosynthesising cyanobacteria that once surrounded waters rising from a spring on the lake floor.

We sent the samples to Australia for further testing to establish whether the microbes played a key role in building the chimneys. This revealed surrounding patches of carbon and nitrogen, which we took to be fossilised cyanobacterial slime. This slime traps calcium and when it breaks down it creates calcium carbonate, entombing any living and dead cells in rock.

We found other ways in which this microbial slime had affected the fabric of the rock: grains of quartz and aluminosilicates that were clearly sand that had got stuck there, too.

Thread-like filaments in the Mono Lake rock.
Alexander Brasier

In short, we found evidence that cyanobacteria formed tubular mats around rising spring water in the ancient Mono Lake – probably producing the majority of the resulting chimneys there, though there may be examples of “pure geochemistry” chimneys as well. This suggests that these rock formations do indeed represent a promising and fairly large target for exploring ancient or extra-terrestrial life.

They have the added advantage that the calcite rocks in question are geologically quite stable. This means the fossils could potentially be preserved for a very long time – easily hundreds of millions, quite plausibly billions of years.

The ConversationTo our knowledge no chimneys have been found on Mars yet, but they are not common on Earth and there is every chance that they have a Martian equivalent. There, and on other planets and moons, we should be looking for areas with conditions as similar as possible to where these chimneys exist on Earth – volcanic rocks where spring waters might once have risen through the bedrock into an alkaline lake. Without any question, NASA’s hunt for suitable rocks on the red planet should make finding them a high priority.

Alexander Brasier, Lecturer in Geology, University of Aberdeen; David Wacey, Australian Research Council Future Fellow, University of Western Australia, and Mike Rogerson, Senior Lecturer in Earth System Science, University of Hull

This article was originally published on The Conversation. Read the original article.

Rover detects ancient organic material on Mars – and it could be trace of past life

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The Curiosity rover on Mars has been busy.

By Monica Grady, The Open University

It was to a great fanfare of publicity that researchers announced they had found evidence for past life on Mars in 1996. What they claimed they had discovered was a fossilised micro-organism in a Martian meteorite, which they argued was evidence that there has once been life on the Red Planet. Sadly, most scientists dismissed this claim in the decade that followed – finding other explanations for the rock’s formation.

While we know that Mars was habitable in the past, the case demonstrates just how hard it will be to ever prove the existence of past life on its surface. But now new results from NASA’s Curiosity rover, including the discovery of ancient organic material, have revived the hope of doing just that. Understandably, the authors of the two papers, published in the journal Science, are very careful not to make the claim that they have discovered life on Mars.

While the 1996 discovery has never been verified, it hasn’t ever been conclusively disproved either. What the study has done, though, is to propel the search for life on Mars higher up the list of international space exploration priorities – giving space agencies ammunition to argue for a coordinated programme of missions to explore the Red Planet.

Mineral veins on Mars seen by Curiosity.

Curiosity is the latest rover to trundle across the gritty sands of Mars. It has been tacking across the floor of Gale Crater on Mars for five years, returning stunning images of Martian landscapes, with vistas opening up to show rocky outcrops seamed with mineral veins. Close up, the veins have the appearance and chemistry of material that has been produced by reaction of water with the rocks, at a time when water was stable at the surface for extended periods of time. Such reactions could create enough energy to feed microbial life.

Ancient rocks

One of the papers reports the discovery of low levels of organic carbon in mudstones from Gale Crater. This might not sound like much carbon – but finding it at all is a big deal, since organic material could be traces of decayed living matter.

The sediments, analysed by the SAM instrument on Curiosity, come from just below the surface, where they have been shielded from most of the UV radiation that would break down organic molecules exposed on the surface. The organic material discovered on Mars is rich in sulphur, which would have also helped to preserve it.

However, the environment in which the mudstones were deposited – a 3.5-billion-year-old lake bed – would have been altered in other ways as the sediments settled and compressed to become rock. Over the intervening years, fluid flowing thought it would have initiated chemical reactions that could have destroyed the organic matter – the material discovered may in fact be fragments from bigger molecules. In rocks on Earth, such reactions – which causes living matter mainly from plants and microbes to degrade – produce an insoluble material known as kerogen.

Excitingly, the material discovered on Mars is similar to terrestrial kerogen. But that doesn’t necessarily mean it is biological in origin – it is also similar to an insoluble material in tiny meteorites that rain down on the surface of Mars.

At this point, we simply don’t know whether the origin is biological or geological. But it is the preservation of the material that is important – if there is this much organic matter preserved close to the surface, then there should be even better protected material at greater depths. What is needed to find more clues is a mission to Mars with a deep drill. Luckily there is one: ESA’s ExoMars rover, scheduled for launch in two years’ time.

Mysterious methane

The second paper investigates a problem that has been disturbing Mars scientists for several years: the abundance of methane in Mars’ atmosphere. Earth-based telescopes, spacecraft orbiting Mars and now Curiosity, have measured episodic sudden increases in the background methane content.

While this might be taken as a signature of biological activity – the main producers of methane on Earth are termites and bovine gut bacteria – non-biological mechanisms, such as weathering of Martian rocks or release from ancient ice, are possible too.

Gale crater on Mars.

The new results represent the longest systematic record of atmospheric methane, with measurements taken regularly over five years. What the authors have found is a systematic variation in methane concentration with season, with the highest concentrations occurring at the Gale Crater towards the end of the northern summer. This is the period when the southern icecap – which freezes carbon dioxide out of the atmosphere, but not methane – is at its biggest, so enhanced methane is not unexpected. However, the abundances of methane measured are greater than models predict should occur, meaning we still don’t know exactly how they are produced.

The team also found several spikes where methane abundance suddenly jumped to be higher than average during the year. The authors conclude that this must be related to surface temperature. They therefore suggest that methane could be trapped at depth, gradually seeping to the surface. Here it is retained by the soil until the temperature increases sufficiently to release the gas.

However the paper states that, despite this, there “remain unknown atmospheric or surface processes occurring in present-day Mars”. While the authors do not specify biology as one of those unknown processes, it remains an intriguing possibility. This, to me, is a cue for further measurements – and fortunately, we may know soon. ESA’s Trace Gas Orbiter is now in place at Mars, and has just started recording data.

So, what can we conclude after reading these two papers? That even with the superb instrument array carried by Curiosity, and detailed modelling and interpretation of the results, we are still left looking for evidence of life on Mars. Is it a romantic yearning to discover that we do have companions within the solar system (even if they are likely to be very small and uncommunicative)? Or is it that our theories of how life arose on Earth cry out to be verified by a “second genesis”?

The ConversationWhatever the reason, there is still much to be discovered on Mars. Luckily, a series of missions planned well into the next decade will help us make those discoveries. These include the return of Martian samples to Earth, where we can carry out even more detailed analyses than Curiosity.

Monica Grady, Professor of Planetary and Space Sciences, The Open University

This article was originally published on The Conversation. Read the original article.

Playing detective with Canada’s female literary past

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Margaret MacLean visited and wrote about the Royal Ontario museum’s collections as well as visiting Egypt for Saturday Night magazine.
(Database of Canadian Women Writers)

By Carole Gerson, Simon Fraser University

Most Canadians know surprisingly little of their country’s literary past, even though many of their great-grandmothers or great-aunts were active participants in Canada’s print culture as poets, journalists, novelists, travel writers and biographers.

While Canadians like to believe their country has produced an extraordinary number of fine women writers, when we look closely, the number of recognized female authors included in influential areas such as anthologies for university courses, nationally focused reprint series and commemorative activities is low — far less than 50 per cent.

However, over the course of the last two and a half centuries, surprisingly large numbers of relatively obscure women got their writings into print — in different genres and on different topics — in magazines, newspapers, anthologies, chapbooks and full-length volumes, even though few would achieve renown or receive attention from scholars.

My research on early Canadian women writers has resulted in the collection of thousands of names, which now appear in the recently launched Database of Early Canadian Women Writers (DoCEWW). This resource includes Canadian women writing in English whose first publication appeared in or before 1950. It was created with support from the Social Sciences and Humanities Research Council of Canada (SSHRC), the Simon Fraser University Faculty of Arts and Social Sciences, the Department of English, and the Digital Humanities Innovation Lab at SFU.

Database of early Canadian women writers

Sarah Jameson Craig is a Canadian writer discovered by her great-grandaughter.
McGill-Queen’s University Press

Some writers, such as Sarah Jameson Craig, were brought out of the shadows by family members — in this case by her great-granddaughter, Prof. Joanne Findon.

While writing was not a major focus of Craig’s life, her various activities as a feminist, health reformer and utopian thinker were, at times, expressed in print.

Craig exemplifies the majority of the writers included in the DoCEWW.

Alongside a smattering of well-known professional authors and journalists such as Lucy Maud Montgomery, Nellie McClung and E. Cora Hind, the database includes some 4,800 Canadian women who published their words occasionally — as manifestations of their interests, professional activities, ideology or creativity, as they got on with their busy lives.

In addition to poetry and stories for children, their writing ranged from pragmatic concerns such as agriculture or knitting, to professional topics or the history of their family or community.

For each writer, DoCEWW provides basic biographical and publication details including names (primary and alternative), places and dates of birth and death, places of residence, titles of books and other publication venues like anthologies and serials.

Naming women writers

Confirming the various names used by women writers can pose quite a challenge because, historically, women have changed their names after getting married and because many women writers used pen names.

In DoCEWW, the author’s primary name is the name that she was best known by, with all her other names listed as alternatives.

For example, the primary name of the woman who wrote Anne of Green Gables appears as L.M. Montgomery, the name under which most of her work was published. Her alternative names include her full birth name (Lucy Maud Montgomery), her married name (Mrs. Ewan MacDonald) and the various pen names she used, mostly at the beginning of her career: Belinda Bluegrass, Cynthia, Joyce Cavendish, Maud Cavendish and J.C. Neville.

Working with a team of excellent student assistants under the expert direction of project manager Karyn Huenemann, we have done our best to disentangle writers who share the same name, such as the two women who published as Mary Agnes Fitzgibbon. One was a granddaughter of pioneer author Susanna Moodie, while the other was a rather flamboyant journalist, Mary Agnes Bernard, who became Fitzgibbon upon marriage.

Finding women writers

Many of the women in this database did not present their writing in separate volumes or chapbooks, but were published in periodicals or anthologies. These two formats are a critical component of Canada’s cultural history.

Database users can track down writers whose names they might find in such newspapers, magazines or anthologies (of which there have been surprisingly many). In this way, researchers can use the database to explore historical publishing practices.

A click on a writer’s name brings up all the titles with which she is associated, and a click on the title of a periodical or anthology brings up the names of all other contributors who appear in the database.

Pioneer paleontologist Madeleine Fritz at work.
(Database of Canadian Women Writers), Author provided

It’s one thing to collect the names of obscure female authors and quite another to pin down who these people actually were. While much can be gleaned through such on-line resources as Ancestry, we have also depended on the knowledge of many others, including librarians, archivists and other custodians of cultural materials, as well as relatives and descendants of writers, and friends and acquaintances who informed us about publications or CBC programs.

For example, a visit to the library and archives of the Royal Ontario Museum (ROM) identified a cluster of female authors not yet on our list.

These writers had engaged in a range of activities that illustrate women’s multifaceted connections with print: Pioneer paleontologist Madeleine Fritz published scholarly research; in 1917, Margaret MacLean, the museum’s first official guide, published educational articles about the ROM’s collections in Saturday Night magazine; classicist Cornelia Harcum published a book about Roman cuisine in 1914 and articles about the ROM’s classical collections in the 1920s; and the extensive careers of Katherine Maw Brett and Dorothy K. Burnham in the ROM’s textile department began with Brett’s 1945 exhibition pamphlet and Burnham’s first book, published in 1950.

Discovering the stories

Serendipity has played a role in identifying many writers now in DoCEWW:

Mary Elizabeth (Connell) Donaldson

Seeing one of Elizabeth Donaldson’s poems on our website, two of her great-nephews asked project manager Karyn Huenemann which of the Mary Elizabeth Donaldsons in their family tree was the poet. Together they solved the mystery and discovered even more poems in old journals. As the author’s granddaughter was looking for a place to donate her grandmother’s papers, we put the family in contact with the archivist at York University.

Amy Clare Giffin

In 1986, the couple who bought the Giffin family home in Isaac’s Harbour, N.S., found her name carved by her childish hand in the glass of many windows as well as a box of writing and ephemera in the attic. Their research led them to our website. Together we learned more of Giffin’s life, but there are still gaps in the biography.

Jane Layhew

Coral Ann Howells at the University of Reading wanted to determine the relationship between Jane Layhew, a nurse from Prince George, B.C., and a Jane Layhew of Montréal, author of Rx for Murder (Lippincott, 1946).

The back and forth exchange of information created a rich understanding of the life of this one-book author, whose husband, Lew Layhew, was a cousin of literary critic Northrop Frye.

Playing detective

While we have resolved many pseudonyms, mysteries still abound.

Who was the unnamed “lady” who had done much research on the Canadian north and issued A Peep at the Esquimaux in London in 1825?

Did Benedictine Wiseman, the eccentric mother of Mavis Gallant, really publish a play as she claimed to have done while still a teenager?

Will we ever identify the woman who sent an undated letter (likely around 1918) to Prof. Archibald MacMechan at Dalhousie University, asking for his opinion of her published collection of poems, and signed herself as “Mrs. Nobody” of “No. 0 Nowhere Street?”

The ConversationThe investigation continues.

Carole Gerson, Professor, English Department, Simon Fraser University

This article was originally published on The Conversation. Read the original article.

How we discovered 840 minor planets beyond Neptune – and what they can tell us

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The Canada-France-Hawaii Telescope (CFHT) at sunset, which observed the OSSOS survey.
wikipedia, CC BY-SA

By Michele Bannister, Queen’s University Belfast

Our solar system is a tiny but wonderfully familiar corner of the vast, dark universe – we have even been able to land spacecraft on our celestial neighbours. Yet its outer reaches are still remarkably unmapped. Now we have discovered 840 small worlds in the distant and hard-to-explore region beyond Neptune. This is the largest set of discoveries ever made, increasing the number of distant objects with well known paths around the sun by 50%.

These little icy worlds are important as they help us tell the solar system’s history. They can also help us test the idea that there’s a yet unseen planet lurking in the outer solar system.

Our planetary system as we see it today is not as it formed. When the sun was newborn, it was surrounded by a massive disk of material. Encounters with tiny, growing planets – including some of the worlds we’ve just discovered – moved the giant planets outward from the sun until they settled into their present locations. The growing planets, on the other hand, went everywhere, scattering both inward and outward.

Planetary migration also happened in far away systems around many other stars. Fortunately, the celestial bodies in our own planetary system are comparatively close by, making it the only place where we can see the intricate details of how migration happened. Mapping the minor planet populations that are left over from the disk lets us reconstruct the history of how the big planets were pushed into place.

Mapping the sky

The new discoveries were made as part of a five year project called the Outer Solar System Origins Survey (OSSOS). The observations, conducted in 2013-2017, used the imaging camera of one of the world’s major telescopes – the Canada-France-Hawaii Telescope on Maunakea in Hawaii. The survey looked for faint, slow-moving points of light within eight big patches of sky near the plane of the planets and away from the dense star fields of the Milky Way.

With 840 discoveries made at distances between six and 83 astronomical units (au) – one such unit is the distance between the sun and the Earth – the survey gives us a very good overview of the many sorts of orbits these “trans-Neptunian objects” have.

Earlier surveys have suffered from losing some of their distant discoveries – when too few observations occur, the predicted path of a minor planet in the sky will be so uncertain that a telescope can’t spot it again, and it is considered “lost”. This happens more to objects with highly tilted and elongated orbits, producing a bias in what’s currently known about these populations.

Our new survey successfully tracked all its distant discoveries. The frequent snapshots we made of the 840 objects over several years meant that each little world’s orbit could be determined very precisely. In total, more than 37,000 hand-checked measurements of the hundreds of discoveries precisely pinned down their arcs across the sky.

We also created an accompanying software “simulator” (a computer model), which provides a powerful tool for testing the inventory and history of our solar system. This lets theorists test out their models of how the solar system came to be in the shape we see it today, comparing them with our real discoveries.

Strange new worlds

The new icy and rocky objects fall into two main groups. One includes those that reside on roundish orbits in the Kuiper belt, which extends from 37au to approximately 50au from the sun. The other consists of worlds that orbit in a careful dance of avoidance with Neptune as it travels around the sun. These “resonant” trans-Neptunian objects, which include Pluto, were pushed into their current elongated orbits during Neptune’s migration outwards.

In the Kuiper belt, we found 436 small worlds. Their orbits confirm that a concentrated “kernel” of the population nestles on almost perfectly round, flat orbits at 43 to 45au. These quiet orbits may have been undisturbed since the dawn of the solar system, a leftover fraction of the original disk. Soon, we will see a member of this group up close: the New Horizons spacecraft, which visited Pluto in 2015, will be flying by a world that’s about the size of London on New Year’s Day 2019.

The dwarf planet candidate 2015 RR245 is on an exceptionally distant orbit, but is one of the few dwarf planets that could one day be reached by a spacecraft mission.
Alex Parker/OSSOS, CC BY-SA

We found 313 resonant trans-Neptunian objects, with the survey showing that they exist as far out as an incredible 130au – and are far more abundant than previously thought. Among these discoveries is the dwarf planet 2015 RR245, which is about half the size of Britain. It may have hopped onto its current orbit at 82au after an encounter with Neptune hundreds of millions of years ago. It was once among the 90,000 scattered objects of smaller size that we estimate currently exist.

Are there more planets?

Among the most unusual of the discoveries are nine little worlds on incredibly distant orbits, never coming closer to the sun than Neptune’s orbit, and taking as long as 20,000 years to travel around our star. Their existence implies an unseen population of hundreds of thousands of trans-Neptunian objects on similar orbits.

Artist’s concept of Planet Nine.
NASA/JPL-Caltech/Robert Hurt, CC BY-SA

How these objects got on their present paths is unclear — some orbit so far out that, even at their closest approach, they are barely tugged by Neptune’s gravity. One explanation that has been put forward is that a yet unseen large planet, sometimes called “Planet Nine”, could be causing them to cluster in space. However, our nine minor planets all seem to be spread out smoothly, rather than clustering. Perhaps the shepherding of such a large planet is more subtle – or these orbits instead formed in a different way.

The ConversationThe history of our solar system is just beginning to be told. We hope this new set of discoveries will help piece together the story.

Michele Bannister, Research Fellow, planetary astronomy, Queen’s University Belfast

This article was originally published on The Conversation. Read the original article.

The Standard Model of particle physics: The absolutely amazing theory of almost everything

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How does our world work on a subatomic level?
Varsha Y S, CC BY-SA

By Glenn Starkman, Case Western Reserve University

The Standard Model. What dull name for the most accurate scientific theory known to human beings.

More than a quarter of the Nobel Prizes in physics of the last century are direct inputs to or direct results of the Standard Model. Yet its name suggests that if you can afford a few extra dollars a month you should buy the upgrade. As a theoretical physicist, I’d prefer The Absolutely Amazing Theory of Almost Everything. That’s what the Standard Model really is.

Many recall the excitement among scientists and media over the 2012 discovery of the Higgs boson. But that much-ballyhooed event didn’t come out of the blue – it capped a five-decade undefeated streak for the Standard Model. Every fundamental force but gravity is included in it. Every attempt to overturn it to demonstrate in the laboratory that it must be substantially reworked – and there have been many over the past 50 years – has failed.

In short, the Standard Model answers this question: What is everything made of, and how does it hold together?

The smallest building blocks

But these elements can be broken down further.
Rubén Vera Koster, CC BY-SA

You know, of course, that the world around us is made of molecules, and molecules are made of atoms. Chemist Dmitri Mendeleev figured that out in the 1860s and organized all atoms – that is, the elements – into the periodic table that you probably studied in middle school. But there are 118 different chemical elements. There’s antimony, arsenic, aluminum, selenium … and 114 more.

Physicists like things simple. We want to boil things down to their essence, a few basic building blocks. Over a hundred chemical elements is not simple. The ancients believed that everything is made of just five elements – earth, water, fire, air and aether. Five is much simpler than 118. It’s also wrong.

By 1932, scientists knew that all those atoms are made of just three particles – neutrons, protons and electrons. The neutrons and protons are bound together tightly into the nucleus. The electrons, thousands of times lighter, whirl around the nucleus at speeds approaching that of light. Physicists Planck, Bohr, Schroedinger, Heisenberg and friends had invented a new science – quantum mechanics – to explain this motion.

That would have been a satisfying place to stop. Just three particles. Three is even simpler than five. But held together how? The negatively charged electrons and positively charged protons are bound together by electromagnetism. But the protons are all huddled together in the nucleus and their positive charges should be pushing them powerfully apart. The neutral neutrons can’t help.

What binds these protons and neutrons together? “Divine intervention” a man on a Toronto street corner told me; he had a pamphlet, I could read all about it. But this scenario seemed like a lot of trouble even for a divine being – keeping tabs on every single one of the universe’s 10⁸⁰ protons and neutrons and bending them to its will.

Expanding the zoo of particles

Meanwhile, nature cruelly declined to keep its zoo of particles to just three. Really four, because we should count the photon, the particle of light that Einstein described. Four grew to five when Anderson measured electrons with positive charge – positrons – striking the Earth from outer space. At least Dirac had predicted these first anti-matter particles. Five became six when the pion, which Yukawa predicted would hold the nucleus together, was found.

Then came the muon – 200 times heavier than the electron, but otherwise a twin. “Who ordered that?” I.I. Rabi quipped. That sums it up. Number seven. Not only not simple, redundant.

By the 1960s there were hundreds of “fundamental” particles. In place of the well-organized periodic table, there were just long lists of baryons (heavy particles like protons and neutrons), mesons (like Yukawa’s pions) and leptons (light particles like the electron, and the elusive neutrinos) – with no organization and no guiding principles.

Into this breach sidled the Standard Model. It was not an overnight flash of brilliance. No Archimedes leapt out of a bathtub shouting “eureka.” Instead, there was a series of crucial insights by a few key individuals in the mid-1960s that transformed this quagmire into a simple theory, and then five decades of experimental verification and theoretical elaboration.

Quarks. They come in six varieties we call flavors. Like ice cream, except not as tasty. Instead of vanilla, chocolate and so on, we have up, down, strange, charm, bottom and top. In 1964, Gell-Mann and Zweig taught us the recipes: Mix and match any three quarks to get a baryon. Protons are two ups and a down quark bound together; neutrons are two downs and an up. Choose one quark and one antiquark to get a meson. A pion is an up or a down quark bound to an anti-up or an anti-down. All the material of our daily lives is made of just up and down quarks and anti-quarks and electrons.

The Standard Model of elementary particles provides an ingredients list for everything around us.
Fermi National Accelerator Laboratory, CC BY

Simple. Well, simple-ish, because keeping those quarks bound is a feat. They are tied to one another so tightly that you never ever find a quark or anti-quark on its own. The theory of that binding, and the particles called gluons (chuckle) that are responsible, is called quantum chromodynamics. It’s a vital piece of the Standard Model, but mathematically difficult, even posing an unsolved problem of basic mathematics. We physicists do our best to calculate with it, but we’re still learning how.

The other aspect of the Standard Model is “A Model of Leptons.” That’s the name of the landmark 1967 paper by Steven Weinberg that pulled together quantum mechanics with the vital pieces of knowledge of how particles interact and organized the two into a single theory. It incorporated the familiar electromagnetism, joined it with what physicists called “the weak force” that causes certain radioactive decays, and explained that they were different aspects of the same force. It incorporated the Higgs mechanism for giving mass to fundamental particles.

Since then, the Standard Model has predicted the results of experiment after experiment, including the discovery of several varieties of quarks and of the W and Z bosons – heavy particles that are for weak interactions what the photon is for electromagnetism. The possibility that neutrinos aren’t massless was overlooked in the 1960s, but slipped easily into the Standard Model in the 1990s, a few decades late to the party.

3D view of an event recorded at the CERN particle accelerator showing characteristics expected from the decay of the SM Higgs boson to a pair of photons (dashed yellow lines and green towers).
McCauley, Thomas; Taylor, Lucas; for the CMS Collaboration CERN, CC BY-SA

Discovering the Higgs boson in 2012, long predicted by the Standard Model and long sought after, was a thrill but not a surprise. It was yet another crucial victory for the Standard Model over the dark forces that particle physicists have repeatedly warned loomed over the horizon. Concerned that the Standard Model didn’t adequately embody their expectations of simplicity, worried about its mathematical self-consistency, or looking ahead to the eventual necessity to bring the force of gravity into the fold, physicists have made numerous proposals for theories beyond the Standard Model. These bear exciting names like Grand Unified Theories, Supersymmetry, Technicolor, and String Theory.

Sadly, at least for their proponents, beyond-the-Standard-Model theories have not yet successfully predicted any new experimental phenomenon or any experimental discrepancy with the Standard Model.

The ConversationAfter five decades, far from requiring an upgrade, the Standard Model is worthy of celebration as the Absolutely Amazing Theory of Almost Everything.

Glenn Starkman, Distinguished University Professor of Physics, Case Western Reserve University

This article was originally published on The Conversation. Read the original article.