It’s Cold in the Ocean but It’s Hotter Inside Sea Otters - The New York Times | Canada News Media
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It’s Cold in the Ocean but It’s Hotter Inside Sea Otters – The New York Times

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To stay warm in frigid seas, the marine mammals rely on an unexpected use of the powerhouses of their cells.

Sea otters run hot. It’s not just a manner of speaking: Scientists have found that the furry mammals’ metabolisms work at a rate three times what might normally be expected from a creature their size, burning swiftly through calories.

They seem to be using much of that energy to generate heat, keeping themselves at a toasty 98.6 degrees Fahrenheit in the frigid ocean, where staying warm is a matter of life and death. But the details of their conversion of food and oxygen into vast reserves of heat have been obscure. Now researchers studying sea otters’ muscles report that the feat involves using the mitochondria in their muscle cells in an unexpected way. Their study was published Thursday in the journal Science.

Unlike whales and polar bears, sea otters don’t have a thick insulating layer of blubber, and their celebrated fur — the thickest in the world, with up to 2.6 million hairs per square inch — is not enough on its own to keep them alive in an ocean that can hover on the edge of freezing. Muscles generate heat as they contract, but scientists have known for some time there is another way that muscles can help animals keep warm, a cellular process with the delightful name of proton leak.

Inside almost all animal cells, little pill-shaped organelles called mitochondria break down sugar molecules to extract energy. (Mitochondria are often called the powerhouses of the cell.) During the final stage of this process, protons pop through a membrane. In biology textbooks, the protons helpfully trickle through tiny spinning pores, driving them like water wheels to make adenosine triphosphate, a compound that serves as the molecular battery powering cellular processes.

But reality is not always so tidy. If protons build up faster than the little water wheels can clear them, they seep across the membrane in other ways. And in skeletal muscle cells, this leakage of protons produces substantial amounts of heat. This is thought to contribute to keeping polar animals warm, said Traver Wright, a professor at Texas A&M University and an author of the new paper.

To see how much proton leak might be occurring in sea otters, Dr. Wright and his colleagues put samples of muscle cells from 21 animals into a special chamber that allowed the researchers to monitor the ins and outs of the cells’ mitochondria. They found that sea otters are capable of tremendous quantities of proton leak, suggesting substantial heat-generating capacity. And they were surprised to discover that this ability was present in both tiny otters and full-grown adults.

In general, an organism’s metabolic capacity is linked to its activity level, Dr. Wright said. But young otters, of an age when they would often be resting on their mother; adults of all sizes; and even a relatively inactive captive otter all had similarly high metabolisms and a great capacity for proton leak. In fact, they had higher rates than even Iditarod sled dogs.

“Their leak metabolic rate isn’t anywhere near as high as in sea otters,” said Dr. Wright of the dogs. For otters, he added, “that heat generation is really the driving force of their metabolic development.”

Sea otters are churning through calories even without a lot of physical activity because that energy goes straight into heat, the results suggest. Otters are among the only animals so far for whom proton leak can explain almost all of their elevated metabolism, Dr. Wright said.

The researchers are hoping to study the metabolisms of a variety of animals. They have already published related work on elephant seals, enormous creatures whose lives include both frenetic diving and eating while at sea, as well as weeks of extended lounging on the beach.

Curiously, while the seals loll on the sand for a month, their metabolic capacity does not decrease. Humans taking a similar hiatus from movement with a piña colada and beach reading in hand would not be so lucky.

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

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