Enlarge / This aerial picture taken on December 8, 2023, shows the US-Mexico border wall in Sasabe, Arizona. (credit: VALERIE MACON/AFP via Getty Images)

In a vast stretch of the Sonoran Desert, between the towns of San Luis Río Colorado and Sonoyta in northern Mexico, sits a modest building of cement, galvanized sheet metal, and wood—the only stop along 125 miles of inhospitable landscape dominated by thorny ocotillo shrubs and towering saguaro cactuses up to 50 feet high. It’s a fonda—a small restaurant—called La Liebre del Desierto (The Desert Hare), and for more than 20 years, owner Elsa Ortiz Ramos has welcomed and nourished weary travelers taking a break from the adjacent highway that runs through the arid Pinacate and Grand Desierto de Altar Biosphere Reserve.

But the dedication and care of this petite woman go beyond her simple menu. Every two weeks, she pays out of pocket for a 5,000-gallon tank of water to distribute to a network of water troughs strategically placed in the area. By doing so, she relieves the thirst of bighorn sheep, ocelots, pronghorn, coyotes, deer, and even bats that have been deprived of access to their natural water sources.

“The crows come to the house and scream to warn us that there is no more water ... it’s our alarm,” says Ortiz Ramos in her distinct northern Mexico accent. Her words sound straight from an Aesop’s fable, but they take on stark realism in this spot. Covering large parts of Arizona, California, and the Mexican states of Baja California and Sonora, the Sonoran Desert—along with the Lut Desert in Iran—was cataloged in 2023 as having the hottest surface temperature on the planet, at 80.8° Celsius (177° Fahrenheit).

Enlarge / Pharma interest and investment in radiotherapy drugs is heating up. (credit: Knowable Magazine)

On a Wednesday morning in late January 1896 at a small light bulb factory in Chicago, a middle-aged woman named Rose Lee found herself at the heart of a groundbreaking medical endeavor. With an X-ray tube positioned above the tumor in her left breast, Lee was treated with a torrent of high-energy particles that penetrated into the malignant mass.

“And so,” as her treating clinician later wrote, “without the blaring of trumpets or the beating of drums, X-ray therapy was born.”

Radiation therapy has come a long way since those early beginnings. The discovery of radium and other radioactive metals opened the doors to administering higher doses of radiation to target cancers located deeper within the body. The introduction of proton therapy later made it possible to precisely guide radiation beams to tumors, thus reducing damage to surrounding healthy tissues—a degree of accuracy that was further refined through improvements in medical physics, computer technologies and state-of-the-art imaging techniques.

Enlarge (credit: Tony C. French/Getty)

In the urgent quest for a more sustainable global food system, livestock are a mixed blessing. On the one hand, by converting fibrous plants that people can’t eat into protein-rich meat and milk, grazing animals like cows and sheep are an important source of human food. And for many of the world’s poorest, raising a cow or two—or a few sheep or goats—can be a key source of wealth.

But those benefits come with an immense environmental cost. A study in 2013 showed that globally, livestock account for about 14.5 percent of greenhouse gas emissions, more than all the world’s cars and trucks combined. And about 40 percent of livestock’s global warming potential comes in the form of methane, a potent greenhouse gas formed as they digest their fibrous diet.

That dilemma is driving an intense research effort to reduce methane emissions from grazers. Existing approaches, including improved animal husbandry practices and recently developed feed additives, can help, but not at the scale needed to make a significant global impact. So scientists are investigating other potential solutions, such as breeding low-methane livestock and tinkering with the microbes that produce the methane in grazing animals’ stomachs. While much more research is needed before those approaches come to fruition, they could be relatively easy to implement widely and could eventually have a considerable impact.

Enlarge (credit: RamonCarretero/Getty)

A hammerhead shark less than one meter long swims frantically in a plastic container aboard a boat in the Sanquianga National Natural Park, off Colombia’s Pacific coast. It is a delicate female Sphyrna corona, the world’s smallest hammerhead species, and goes by the local name cornuda amarilla—yellow hammerhead—because of the color of its fins and the edges of its splendid curved head, which is full of sensors to perceive the movement of its prey.

Marine biologist Diego Cardeñosa of Florida International University, along with local fishermen, has just captured the shark and implanted it with an acoustic marker before quickly returning it to the murky waters. A series of receivers will help to track its movements for a year, to map the coordinates of its habitat—valuable information for its protection.

That hammerhead is far from the only shark species that keeps the Colombian biologist busy. Cardeñosa’s mission is to build scientific knowledge to support shark conservation, either by locating the areas where the creatures live or by identifying, with genetic tests, the species that are traded in the world’s main shark markets.