News in 5: Mum mauled by dog; Australian SIDS breakthrough; Einstein's happiness note.

1. Woman killed by the dog she called her “best friend” was trying to protect visitor.

A woman has died after being attacked by her dog - her "best friend" - in suburban Canberra in the early hours of Wednesday morning.

It has been revealed that the mother-of-three, Tania Klemke, was trying to save a man visiting her house in Watson after the animal began to attack, News Corp reports.

She put herself in harm's way to protect the visitor, according to ACT Police who spoke to AAP, and died at the scene at 3:40am on Wednesday.

Police, who were called to the scene by concerned neighbours, shot the dog as it wouldn't let them provide medical assistance to the woman. The man, who was also injured, was taken to hospital where he is reportedly in a stable condition.

Klemke, aged in her 40s, described her dog as her "best friend" in a series of text messages sent to a friend this month, Fairfax reports.

Though she knew the dog was dangerous - the "last person who tried coming in ended up in hospital with 42 stitches," one of the messages reportedly said - Klemke was hesitant to part with it as it had reportedly saved her during a home invasion earlier this year. It's understood the dog was shot in the ear while protecting her from the armed burglars.

"On one previous occasion (Domestic Animal Services) did attend that household at the request of ACT police," City Services Minister Meeghan Fitzharris told the ABC, referring to the incident in August. "I understand that someone may have been injured, and I also understand that the dog may have been injured in that attack as well ... Clearly the dog was dangerous."

Klemke's son, Cody Baker, issued a statement to the press paying tribute to his mother, Seven News reports.

"She had the biggest heart," his statement reads. "And always did anything that she possibly could for the people she loved and cared for."

The breed of the dog has not yet been made public.

2. Police resume search for missing mum Tanja Ebert in South Australia.

Mother of man who shot himself after wife's 'disappearance' reveals who she blames for his death https://t.co/S0r48OMq8v #TanjaEbert #7News pic.twitter.com/79efkbRWzv

— 7 News Sydney (@7NewsSydney) September 12, 2017

Police have searched 18 dams on an isolated sheep station in South Australia's northeast as they continue to investigate the disappearance and suspected murder of mother-of-two Tanja Ebert.

Officers returned to the Manna Hill property last week where Ms Ebert had lived with her husband and two sons before she went missing in August.

Her body has never been found and her husband, Michael Burdon, 41, shot and killed himself when police went to the property a week after she was reported missing.

Police said officers from the Major Crime Investigation Branch and divers returned to Manna Hill last Tuesday and searched the 18 dams and other water storage areas over three days, AAP reports.

"Unfortunately, Ms Ebert has not yet been located," they said.

It's the third time police have conducted major operations on the 410 sq km property.

The last independent sighting of Ms Ebert came on August 8 when she visited the SA Museum in Adelaide with her husband and sons.

As the family drove back to Mannahill, Mr Burdon told police she became agitated and got out of the car near Roseworthy, north of the city, and walked off. But he did not report the 23-year-old missing. Another family member contacted authorities two days later.

Ms Ebert arrived in Australia from Germany several years ago and married Mr Burdon in February.

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14. Suicide Call Back Service 1300 659 467.

3. Australian researchers make breakthrough into cause of SIDS in babies.

Fact: Babies are at risk of SIDS only until they are 1 year old. Bust the myths and learn the facts about SIDS here: https://t.co/4O0ND2zd05 pic.twitter.com/tUYa0hkXX3

— SwaddleMe (@SwaddleMeU) October 25, 2017

Babies who die of SIDS typically lack a brain chemical that helps control head and neck movement, leaving them unable to move out of life-threatening positions, a breakthrough Australian study has shown.

The findings could soon lead to screening tests to identify babies most at risk of sudden infant death Syndrome (SIDS).

University of Adelaide Professor Roger Byard says a crucial part of the SIDS puzzle has now been solved, AAP reports.

He and his team tested brain samples from babies who died of SIDS and found that in the vast majority of cases they had much lower levels of substance P.

Substance P is a chemical in the back of the brain that controls a range of functions, including the response to low-oxygen situations such as the ones babies can get into when they roll onto their tummies.

"What we found in these SIDS babies is that they had significantly lower levels of substance P in areas that are related to the movement of the head and neck," Prof Byard said.

"For 25 years we've been saying, why do SIDS babies not get out of a dangerous situation when they are face down? Why don't they just lift their heads up and cry and thrash around to get their parents' attention? Well, they just don't move as well as normal babies do."

Prof Byard said the vast majority of brain samples he and his colleagues, Professor Robert Vink and Dr Fiona Bright, examined were short of substance P. That was particularly true for boys, who account for twice as many SIDS deaths as girls.

4. In 1922 Einstein wrote down the key to happiness instead of a tip. Now, the note has been sold for $1.7m.

Einstein scribbled his theory of happiness in place of a tip. It just sold for more than $1 million. https://t.co/fgeMGWGLMj

— Washington Post (@washingtonpost) October 25, 2017

Strapped for cash in a Tokyo hotel, Albert Einstein wrote his take on life on a note and handed it to the bellboy instead of a tip. The physicist's formula for happy living has fetched $US1.3 million ($A1.7 million) at an auction in Jerusalem.

In 1922, Einstein was en route to Japan when the announcement came he would be awarded the 1921 Nobel prize in physics, Winner's Auctions and Exhibitions said on Tuesday.

Upon his arrival in Tokyo, he holed up in his hotel room trying to put his thoughts to paper.

When an attendant came to his room to make a delivery, Einstein found himself without any money for a tip.

Instead, he handed him a signed note with one sentence, written in German: "A calm and humble life will bring more happiness than the pursuit of success and the constant restlessness that comes with it".

According to the auction house, Einstein advised the bellboy to keep the note, saying that some day its value will surpass the amount of a standard tip, AAP reports.

Almost a 100 years later, Einstein was proven right after the bellboy's nephew contacted the auction house to put the note up for sale. The identity of the online buyer has not been revealed.

5. Michaelia Cash staffer tipped off the media about police raids at Australian Workers Union.

Michaelia Cash staffer resigns over federal police raids on AWU offices #auspol https://t.co/TDtaxZAPOH pic.twitter.com/2jUhJYNrZC

— ABC News (@abcnews) October 25, 2017

Employment Minister Michaelia Cash admits one of her staff members was aware of the pending federal police raids at two offices of the Australian Workers Union and tipped off media.

Senator Cash had repeatedly denied during a Senate estimates hearing on Wednesday her office was responsible for informing the media of the raids.

But after being made aware of the leak during the hearing's dinner break, she told the senate committee her senior media adviser admitted telling the media and had immediately resigned, AAP reports.

He said his information came from a media source.

"Without my knowledge, one staff member in my office - in the course of discussions with journalists - indicated that he had received information that a raid may take place," she told the senate committee.

Senator Cash denied she misled parliament with her earlier denials.

"I was not aware of it at the time and was not aware of it earlier today at Senate estimates. This took place without my knowledge and was not authorised by me," she said.

Labor frontbencher Tony Burke told parliament the admission was scandalous and called for Senator Cash to resign.

The Australian Federal Police raided the Sydney and Melbourne offices after the Registered Organisations Commission received a warrant from a magistrate amid concerns documents could be destroyed.

Following a referral by Senator Cash, the ROC has been investigating the legitimacy of the AWU's $100,000 donation to activist group GetUp! in 2005 when Labor leader Bill Shorten ran the union.

It is also investigating whether $100,000 worth of campaign donations, including $25,000 to Mr Shorten for his bid to enter parliament in 2007, were within the union's rules.

6. Singer Gotye unveiled as part of enormous Sydney Festival program.

Say hello to #sydfest 2018! Explore the enormous #sydfest program at https://t.co/AZn9ecjuK1 pic.twitter.com/v4uJhUT6es

— Sydney Festival (@sydney_festival) October 25, 2017

What do Gotye, Germaine Greer and the Go-Betweens have in common? The unlikely trio will be at the next Sydney Festival in January.

The Somebody That I Used to Know singer will perform his Tribute to French electronic music producer Jean-Jacques Perrey over two nights, it was announced at the Sydney Festival program launch on Wednesday, AAP reports.

Gotye, real name Wally de Backer, has spent the last few years working on his tribute to Perrey on the ondioline, a rare electronic keyboard, and will perform with his new ensemble, the Ondioline Orchestra.

It's the first solo musical project since his 2011 album Making Mirrors featuring his massive Grammy-award winning song Somebody That I Used to Know.

Sydney! January! Come and hear me play Ondioline in tribute to Jean-Jacques Perrey @sydney_festival #ondioline https://t.co/4SublxzmOS

— gotye (@gotye) October 25, 2017

Renowned feminist Germaine Greer will also be featured as the subject of a new play, Town Hall Affair, performed by New York theatre company The Wooster Group, which reimagines a 1971 debate between author Norman Mailer and feminists Jill Johnston and Germaine Greer (played by Maura Tierney).

Greer will attend the play's Australian premiere at the festival and will give a talk the following night at the Sydney Opera House.

Other highlights include RIOT, the all-Irish political variety show starring famed drag queen Panti Bliss, which will take place at Hyde Park's Spiegeltent, and Fleabag, the one-woman play by Phoebe Waller-Bridge that has become a hit BBC series.

* Sydney Festival runs January 6-28, 2018.