Rat poisons are showing up in wolves, mountain lions and otters

A packed Baltimore trolley illustrates the ups and downs of US public transit

Nicholas Dagen Bloom, Hunter College

When US cities offered low-cost, high-quality public transit during World War II, buses and trains were full. Some cities are trying to revive that formula, after decades of disinvestment.

How San Francisco’s Democratic political machine led to Kamala Harris’ presidential campaign

Lincoln Mitchell, Columbia University

Kamala Harris is the heir to a political lineage that dates back to a chain-smoking, hard-drinking and profane political mastermind first elected to Congress from San Francisco in 1964.

Despite Donald Trump’s claims, his gag order holds up against the Constitution

Lynn Greenky, Syracuse University

While the First Amendment protects a wide range of different kinds of speech, there is no fundamental right to cause harm.

The problem with pronatalism: Pushing baby booms to boost economic growth amounts to a Ponzi scheme

Emily Klancher Merchant, University of California, Davis; Win Brown, University of Washington

Many countries are enacting measures to counter population decline, but manipulating fertility is an inefficient means of solving social, economic and environmental problems.

No credit score? A grocery list could be the next best thing

Joonhyuk Yang, University of Notre Dame; Jung Youn Lee, Jones Graduate School of Business at Rice University

What you buy at the grocery store can predict whether you pay your credit card bills on time, new research suggests.

Dealing with election anxiety? A psychiatrist explains how to channel your fears and break out of tribal thinking

Arash Javanbakht, Wayne State University

The human tendency to form group affiliations and vilify outsiders can help ramp up your anxiety during a contentious election cycle. But you can push back on those fears.

Infectious diseases spike when kids return to school − here’s what you can do about it

Libby Richards, Purdue University

Proper hygiene, vaccinations and healthy habits can all reduce the spread of diseases in school.

Paris Games herald a new anti-corruption era, but carrying the torch may pose an Olympic challenge for the US

Andy Spalding, University of Richmond

France’s distinctive anti-corruption legal framework made possible an Olympics free from major corruption scandals.

The real ‘Big Bang’ of country music: How Vernon Dalhart’s 1924 breakthrough recordings launched a genre

Ted Olson, East Tennessee State University

A musicologist explains how an oft-forgotten opera, pop and jazz singer from New York City launched the country music industry a century ago.

How do breakdancers avoid breaking their necks?

Aliza Rudavsky, Penn State

A term emerged in the 1980s for a spinal cord injury caused by breaking called ‘break-dancing neck.’

This anthropology course looks at building design from the standpoint of different species

Richard Fadok, University of Rochester

Humans aren’t the only species to consider when constructing new buildings. This course teaches students to take animals into account as well.

Trees don’t like to breathe wildfire smoke, either – and they’ll hold their breath to avoid it

Brain implants to restore sight, like Neuralink’s Blindsight, face a fundamental problem − more pixels don’t ensure better vision

Kamala Harris’ identity as a biracial woman is either a strength or a weakness, depending on whom you ask

The Conversation U.S. weekly news quiz

Fritz Holznagel, The Conversation

Here’s the first question of this week’s edition:

Democrat Kamala Harris has chosen Minnesota Gov. Tim Walz as her running mate for 2024. Walz has been a congressman, a teacher and a command sergeant major in the National Guard. What other job has he also held?

1. A. Puppeteer
2. B. Smoke jumper
3. C. HVAC installer
4. D. Football coach

Test your knowledge