Good morning, this is Helen Sullivan bringing you the main stories and must-reads on Monday 28 January.

Top stories

The remains of an Australian university professor and her sister have been discovered in a shallow grave near the city of Mendoza, Argentinian authorities say. Autopsy results released on Sunday showed that at least one of the two had been shot. The bodies of 54-year-old Australian scientist Lily Pereg and her 63-year-old sister, Pirhya Sarussi, were found Saturday on a lot beside the home of Sarussi’s son Gilad Pereg, 36, who was arrested on homicide charges.

Venezuela’s opposition leader Juan Guaidó, who last week declared himself the rightful interim president, has played down fears of a possible armed conflict and claimed his economically devastated nation was living through an “almost magical moment” in its newly revived quest for democracy. In one of his first interviews since last Wednesday’s surprise move, Guaidó told the Guardian he was set on “getting the job done” to force Nicolás Maduro from power and end a humanitarian emergency which has fuelled the largest exodus in modern Latin American history.

Australian single mothers placed on a compulsory welfare program for disadvantaged parents allege they were forced to allow “sensitive” data to be collected. The program, ParentsNext, which is the subject of a Senate inquiry, is compulsory for those who want to receive parenting payments, but government guidelines state participants may decline to sign the form consenting to data collection. However, some case workers have told participants they would have their payments cut if they refused to sign. “She [my case worker] just said, flat out, ‘If you don’t sign it, you won’t get your parenting payment’,” said one mother. A spokeswoman for the Department of Jobs and Small Business said signing the form allowed “information to be collected for the department and the provider, so that participants can be provided with appropriate employment services and support”.

World

Facebook Twitter Pinterest Roger Stone outside court on Friday. Photograph: Joshua Prezant/AFP/Getty Images

Longtime Donald Trump adviser Roger Stone is hedging his bets on cooperation with special counsel Robert Mueller, saying he would have to consult his attorneys about potentially cooperating. Stone has repeatedly said he will not testify against Trump.

Theresa May’s hopes of securing compromise from the European Union on the backstop element of her Brexit plan have been dealt a blow after Ireland firmly said it must stay.

Firefighters have called for the evacuation of about 24,000 people from the Brazilian town hit by a deadly mudslide unleashed by a ruptured mining dam, as rains raised fears a second dam could collapse.

Twenty people were killed and 81 injured in the Philippines after two bombs exploded outside a Roman Catholic cathedral where Muslim militants are active, security officials said.

Antarctic explorers hope to break way through 120km of sea ice to reach the final resting place of Sir Ernest Shackleton’s ship the Endurance, which sank to the bottom of the Weddell Sea in 1915.

Opinion and analysis

Facebook Twitter Pinterest The whip owned by David Blackburn, the commander of the Sirius. It was originally an Aboriginal weapon. Photograph: by the South Australian Museum

Blackburn’s whip is a shocking reminder of Australia’s history, writes Paul Daley. The weapon comprises a sturdy piece of fashioned wood, bulbous at one end, attached with four knotted strands of rope at its tapered extremity. “It is, to all intents and purposes, a late 18th century cat o’ nine tails, an instrument of punishment in the navy … But it is so much more than that. The wooden handle is actually an Aboriginal weapon – at once a bludgeon and a missile of the sort carried by Indigenous men,” Daley writes. “I found it – and continue to find it – both repellent and intriguing. It is compelling for its power to embody and evoke so much history, as a source of so much of what happened after the fleet’s arrival.”

A common response when the public hears about biocontrol programs is to point to one introduction that went badly wrong – the cane toad. But CSIRO scientist Raghu Sathyamurthy says current methods have much greater protections. “It’s always a relevant question, but if cane toads had gone through this process then it would have been cut off at the first hurdle … We’re incredibly cognisant of the risks of getting this wrong. We want a safe fix and we’re incredibly mindful of what we do.” Sathyamurthy is testing a tiny weevil as a possible biocontrol agent against the aquatic plant cabomba, which is choking waterways along the east coast. His weevil colony is maintained behind 2cm thick glass inside a double-air-locked quarantine laboratory. “If the weevil feeds on other Australian plants, then we’d stop right there,” Sathyamurthy says.

Sport

Novak Djokovic is close to perfection as he wins his seventh Australian Open title, writes Kevin Mitchell. He is the best male tennis player in the world: now, and for the foreseeable future, perhaps until he chooses to retire, which looks to be a few years away yet, he hinted on Sunday night.

At the age of 21, Naomi Osaka has two grand slam titles. When she wakes up this morning she will find No 1 next to her name on the world ranking list. It does not get much better than this. Yet it could do, quickly, writes Simon Cambers.

Thinking time: In the land of the trolls

Facebook Twitter Pinterest Ginger Gorman: ‘I don’t condone what they do, but you have to ask why.’ Photograph: Hilary Wardhaugh

After writing a story for the ABC in 2010 about gay men choosing surrogacy, in which she unknowingly profiled two convicted paedophiles, Ginger Gorman found herself besieged by predator trolls. Now she has written a book, Troll Hunting, to “try and bring a humanity to it all, to the victims and the perpetrators”. But Gorman says some people were unimpressed that she was amplifying trolls. “They said, ‘All they want is power. Why are you engaging with them?’ I found that incredible. I’m engaging with them because I want to know what they want. I don’t condone what they do, but you have to ask the question: ‘Why are they doing this?’”

Gorman found many trolls had experienced mental health and substance-use problems. “That was quite confronting for me,” she says. “As journalists we need to examine our own beliefs and take them apart in the context of what we’re writing about, not just like spit stuff out hook, line and sinker.” But she doesn’t forget that her subjects have targeted some of the most vulnerable people on the internet. “We can’t have marginalised voices driven out of these spaces,” she says. “I don’t think I can leave this [subject] behind until there’s a monumental societal shift to make it fairer and less terrifying.”

Media roundup

The Indonesia head of UNHCR has told the Australian the UN will continue to lobby to end Australia’s policy of turning back asylum boats, a practice he says puts lives at risk. The Age reports that doctors are seeking legal advice over whether they could face lawsuits for mishaps that occur as a result of incorrect patient data on My Health Record. And the Sydney Morning Herald reports that judges are now permitted not to impose prison terms on minor drug dealers, following a landmark decision that has “completely changed” the legal landscape.

Coming up

Christopher Pyne is due to give a speech in Singapore today calling on China to act with greater responsibility in the South China Sea.

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