Thursday, May 17, 2018

Dementia & Exercise

'Surprising' study suggests exercise may make dementia worse

A healthy brain (left) and the brain of an Alzheimer's patient (right) CREDIT: DR ROBERT FRIEDLAND/SCIENCE PHOTO LIBRARY

Exercise does not slow down mental decline and may even make dementia worse, a new study suggests.

Oxford University found that people with mild to moderate dementia who went to the gym twice a week for up to 90 minutes went downhill faster than those who abstained.

Although the difference between the two groups was small, the researchers say exercise should not be recommended for people with dementia and called for future trials to ‘consider the possibility that some types of exercise intervention might worsen cognitive impairment.’

Previous research had suggested that exercise could prevent mental decline, and stave off diseases like Alzheimer’s, so experts and charities said they were surprised by the findings.

Commenting on the study, which was published in the BMJ, Rob Howard, Professor of Old Age Psychiatry at University College Londonsaid: “Had this been instead an improvement in cognitive functioning with exercise we would all have been excited about finding something positive in the, so far, depressing fight against dementia.

“On this basis, I don’t think we should ignore the possibility that exercise might actually be slightly harmful to people with dementia.”

Dr James Pickett, Head of Research and Development at Alzheimer's Society, added :“The results are somewhat surprising as we would anticipate that exercise would have positive effects.”

Around 850,000 people in Britain currently suffer from dementia and there are currently no treatments to reverse or slow down the condition. The numbers are expected to rise as the population ages.

The difference between dementia and Alzheimers – in 60 seconds

The new trial involved 494 people with an average age of 77 years who lived in England and all suffered from mild to moderate dementia.

The participants were assigned to a supervised exercise and support programme or usual care.

The programme consisted of 60-90 minute group sessions in a gym twice a week for four months, plus home exercises for one additional hour each week with ongoing support.

All were tested using the Alzheimer’s disease assessment score at the beginning of the study and then at six and 12 months.

After taking account of potentially influential factors, the researchers found that cognitive impairment declined over the 12-month follow-up in both groups.

Dementia and physical activity CREDIT: BMJ

The exercise group showed improved physical fitness in the short term, but higher ADAS-cog scores at 12 months (25.2 v 23.8) compared with the usual care group, indicating worse cognitive impairment.

Commenting on the findings, Dr Brendon Stubbs, Post-doctoral Research Physiotherapist at the Institute of Psychiatry, Psychology and Neuroscience, King's College London, said: "Whilst previous smaller studies have suggested that exercise can prevent or improve cognitive decline in people with Alzheimer’s disease, this robust and very large study provides the most definitive answer we have on the role of exercise in mild-moderate Alzheimer’s disease.

“The study finds that whilst it is possible for interested people with Alzheimer’s disease to engage in a robust supervised exercise program, this does not appear to delay cognitive decline and does not improve any other outcome besides physical fitness.

“The search for effective lifestyle interventions that can delay cognitive decline in dementia must continue.”

Hitting the gym once dementia has begun may not help the condition, scientists suspect CREDIT: TAO KE FOR CHINA DAILY

Dr Elizabeth Coulthard, Consultant Senior Lecturer in Dementia Neurology at the University of Bristol, said: “The findings here are in keeping with the thrust of current research that suggests dementia is hard to modify once it is well established.

“There has been some promising work on exercise in people with milder symptoms such as those with Mild Cognitive Impairment. Physical activity still holds promise to delay dementia onset in people at risk of developing the disease.

“Broadly, physical activity and healthy ageing go hand in hand. However, targeting physical activity as an intervention to improve specific disease processes is a challenge."2330

Monday, May 7, 2018

Yes, Pluto is a planet

By David Grinspoon and Alan Stern May 7 at 6:00 AM

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Three years ago, NASA’s New Horizons, the fastest spaceship ever launched, raced past Pluto, spectacularly revealing the wonders of that newly seen world. This coming New Year’s Eve — if all goes well on board this small robot operating extremely far from home — it will treat us to images of the most distant body ever explored, provisionally named Ultima Thule. We know very little about it, but we do know it’s not a planet. Pluto, by contrast — despite what you’ve heard — is.

Why do we say this? We are planetary scientists, meaning we’ve spent our careers exploring and studying objects that orbit stars. We use “planet” to describe worlds with certain qualities. When we see one like Pluto, with its many familiar features — mountains of ice, glaciers of nitrogen, a blue sky with layers of smog — we and our colleagues quite naturally find ourselves using the word “planet” to describe it and compare it to other planets that we know and love.

In 2006, the International Astronomical Union (IAU) announced an attempted redefinition of the word “planet” that excluded many objects, including Pluto. We think that decision was flawed, and that a logical and useful definition of planet will include many more worlds.

We find ourselves using the word planet to describe the largest “moons” in the solar system. Moon refers to the fact that they orbit around other worlds which themselves orbit our star, but when we discuss a world like Saturn’s Titan, which is larger than the planet Mercury, and has mountains, dunes and canyons, rivers, lakes and clouds, you will find us — in the literature and at our conferences — calling it a planet. This usage is not a mistake or a throwback. It is increasingly common in our profession and it is accurate.

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Most essentially, planetary worlds (including planetary moons) are those large enough to have pulled themselves into a ball by the strength of their own gravity. Below a certain size, the strength of ice and rock is enough to resist rounding by gravity, and so the smallest worlds are lumpy. This is how, even before New Horizons arrives, we know that Ultima Thule is not a planet. Among the few facts we’ve been able to ascertain about this body is that it is tiny (just 17 miles across) and distinctly nonspherical. This gives us a natural, physical criterion to separate planets from all the small bodies orbiting in space — boulders, icy comets or rocky and metallic asteroids, all of which are small and lumpy because their gravity is too weak for self-rounding.

The desire to reconsider the meaning of “planet” arose because of two thrilling discoveries about our universe: There are planets in unbelievable abundance beyond our solar system — called “exoplanets” — orbiting nearly every star we see in the sky. And there are a great many small icy objects orbiting our sun out in Pluto’s realm, beyond the zone of the rocky inner worlds or “terrestrial planets” (like Earth), the “gas giants” (like Jupiter) and the “ice giants” (like Neptune).

In light of these discoveries, it did then make sense to ask which objects discovered orbiting other stars should be considered planets. Some, at the largest end, are more like stars themselves. And just as stars like our sun are known as “dwarf stars” and still considered stars, it made some sense to consider small icy worlds like Pluto to occupy another subcategory of planet: “dwarf planet.”

But the process for redefining planet was deeply flawed and widely criticized even by those who accepted the outcome. At the 2006 IAU conference, which was held in Prague, the few scientists remaining at the very end of the week-long meeting (less than 4 percent of the world’s astronomers and even a smaller percentage of the world’s planetary scientists) ratified a hastily drawn definition that contains obvious flaws. For one thing, it defines a planet as an object orbiting around our sun — thereby disqualifying the planets around other stars, ignoring the exoplanet revolution, and decreeing that essentially all the planets in the universe are not, in fact, planets.

Even within our solar system, the IAU scientists defined “planet” in a strange way, declaring that if an orbiting world has “cleared its zone,” or thrown its weight around enough to eject all other nearby objects, it is a planet. Otherwise it is not. This criterion is imprecise and leaves many borderline cases, but what’s worse is that they chose a definition that discounts the actual physical properties of a potential planet, electing instead to define “planet” in terms of the other objects that are — or are not — orbiting nearby. This leads to many bizarre and absurd conclusions. For example, it would mean that Earth was not a planet for its first 500 million years of history, because it orbited among a swarm of debris until that time, and also that if you took Earth today and moved it somewhere else, say out to the asteroid belt, it would cease being a planet.

To add insult to injury, they amended their convoluted definition with the vindictive and linguistically paradoxical statement that “a dwarf planet is not a planet.” This seemingly served no purpose but to satisfy those motivated by a desire — for whatever reason — to ensure that Pluto was “demoted” by the new definition.

By and large, astronomers ignore the new definition of “planet” every time they discuss all of the exciting discoveries of planets orbiting other stars. And those of us who actually study planets for a living also discuss dwarf planets without adding an asterisk. But it gets old having to address the misconceptions among the public who think that because Pluto was “demoted” (not exactly a neutral term) that it must be more like a lumpy little asteroid than the complex and vibrant planet it is. It is this confusion among students and the public — fostered by journalists and textbook authors who mistakenly accepted the authority of the IAU as the final word — that makes this worth addressing.

Last March, in Houston, planetary scientists gathered to share new results and ideas at the annual Lunar and Planetary Science Conference. One presentation, titled “A Geophysical Planet Definition,” intended to set the record straight. It stated: “In keeping with both sound scientific classification and peoples’ intuition, we propose a geophysically-based definition of 'planet' that importantly emphasizes a body’s intrinsic physical properties over its extrinsic orbital properties.” After giving a precise and nerdy definition, it offered: “A simple paraphrase of our planet definition — especially suitable for elementary school students — could be, ‘round objects in space that are smaller than stars.’”

It seems very likely that at some point the IAU will reconsider its flawed definition. In the meantime, people will keep referring to the planets being discovered around other stars as planets, and we’ll keep referring to round objects in our solar system and elsewhere as planets. Eventually, “official” nomenclature will catch up to both common sense and scientific usage. The word “planet” predates and transcends science. Language is malleable and responsive to culture. Words are not defined by voting. Neither is scientific paradigm.

David Grinspoon is an astrobiologist who studies climate evolution and habitability of other worlds. Alan Stern is the principal investigator of the New Horizons mission to Pluto and the Kuiper belt. Their book “Chasing New Horizons: Inside the Epic First Mission to Pluto,” was published May 1 by Picador.

Monday, April 23, 2018

Boston Marathon 2018

Who the heck is Boston Marathon runner-up Sarah Sellers, anyway?

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By Jaclyn Reiss GLOBE STAFF APRIL 16, 2018

SCOTT EISEN/GETTY IMAGES

Sarah Sellers of the United States crossed the Boston Marathon finish line in second place with a time of 2:44:04.

Desiree Linden stunned the nation when she became the first American woman to win the Boston Marathon in 33 years on Monday.

But as Linden soaked up the glory, many spectators had a burning question: Who the heck is Sarah Sellers, the American who finished second in the race, about four minutes behind Linden?

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At first glance, Sellers seemed to have a low profile on social media (although there does appear to be a country music singer by the same name), and Google searches of her name turned up little to nothing. She was not identified in many photos moved by wire services on Monday, and several breaking stories mentioned her just once — to note that she finished second.

Sellers — née Sarah Callister — is a 26-year-old full-time nurse working in anesthesiology at Banner Health Center in Arizona, her husband, Blake Sellers, told the Globe in an interview on Monday.

The Boston Marathon was just Sellers’s second marathon. The first was the Huntsville Marathon in Utah, which she ran as a qualifier for Boston and won, her husband said.

She didn’t know that she placed second in the Boston Marathon, he said, until someone informed her after she crossed the finish line.

“Someone had to tell her, and she still didn’t believe them,” he said.

In an interview with the Globe, Sarah Sellers said the whole thing felt “surreal,” and that she at first didn’t think she actually came in second overall.

“I didn’t even know it was a possibility,” she told the Globe. “I was trying to ask officials what place I was in. I had no idea when I crossed the finish line.”

SCOTT EISEN/GETTY IMAGES

Sarah Sellers (far right) during the Boston Marathon in Brookline. Also pictured are, from left, Nicole Dimercurio and Rachel Hyland.

Sellers qualifies for the prize money — which, for second place, is $75,000, a Boston Athletic Association official told the Globe Monday night.

“Best case scenario going in, I thought I would maybe win enough money to cover the trip out here,” she said. “I had no anticipations of winning $75,000.”

So how does she plan to spend the money?

“I don’t even have any plans yet. I had no idea that was even a possibility,” she said. “My husband and I both just finished graduate school, so hopefully we’ll be able to put a dent in our student loans.”

Sellers plans to go back to work in Arizona on Wednesday, and laughed when she was asked if she planned on quitting her job to focus on running full-time.

“I definitely will plan on working,” she said. “I love working as a nurse anesthetist. It does make training a little bit challenging, but long term, I love both, and I wouldn’t want to give up working right now.”

Blake Sellers said he accompanied his wife to Boston — as well as her parents and her brother, who also ran the marathon — and saw her shortly after she finished.

“She was in disbelief,” he said. “It is quite an accomplishment. I was amazed.”

He said that his wife has been waking up at 4 a.m. to get in her training runs before working full shifts at the medical center.

“She works super, super hard,” he said.

Sarah was a long distance runner as an undergraduate student at Weber State University in Ogden, Utah. Blake said Sarah was hoping to place in the top 15 of the Boston Marathon and to qualify for the Olympic trials.

PHOTO COURTESY OF WEBER STATE UNIVERSITY

Sarah Sellers, nee Sarah Callister, at Weber State University.

Her college running coach, Paul Pilkington, said Sarah overcame another obstacle: As a senior about five years ago, she broke a bone in her foot.

“It was really slow to heal,” Pilkington said. “It took her three years to get healthy again after that break.”

Sarah herself acknowledged that after her foot injury, she didn’t run a step for a whole year.

“When I did start running again, it was during grad school” at Barry University in Florida, she said. “I was doing a lot of hours with clinicals and studying, so I wasn’t really training, just running for fitness.”

Meanwhile, Pilkington said that as an undergrad, Sarah ran 32:51 in the 10,000 meters, “which is a good collegiate finishing time.”

“The one thing about her college career, that I was upset as a coach, is she should have been an NCAA All American, but she had a broken foot,” he said.

Pilkington described his former pupil as “determined.”

“That’s one of the things about her — she’s really mentally tough, which I think really helped her under today’s conditions in Boston,” he said. “She sent me a text saying she won the hypothermia bowl today,” he added, laughing. “I just spoke to her on the phone. She said, ‘I think I’m going to wake up and find out this didn’t happen.’”

A statement on Weber State’s website also touted Sellers’ college running career.

She had a 4.0 GPA in college, and majored in nursing, according to the school.

According to The Running Shop in Tucson, Sellers popped by in February to buy her running shoes before the race.

The pair she ended up buying? New Balance 1400s — for a relatively low price of about $90, according to Geoff Schmidt, a shoe fit specialist at the store.

Lucas Tyler, a manager at the shop, said Sellers was very nonchalant while talking about prepping for the Boston Marathon.

“She made a comment that she was going to Boston, but she kind of made it sound like she was just going to run Boston, that this wasn’t a huge deal,” Tyler said. “She said 2:45 [two hours and 45 minutes] was her PR [personal record], and in the past, with 2:45 you have been able to place pretty well in Boston. We were like, OK, what is she talking about? I mean, 2:45 is fast.”

Tyler also said that Sellers appeared to take training very seriously, but her tone was light in the store.

“She was very casual about it, not in your face bragging,” he said. “She was just excited about going out and running.”

And as her story rocketed around the Internet on Monday, Sellers said she was still in shock.

“I don’t consider myself any sort of running icon, because I’m not,” she said. “I’ve done nothing notable up to this point.”

However, she said she could understand why so many people could relate to her triumph.

“I think my story probably resonates with a lot of people that work really hard and have big goals,” she said. “I think it’s cool to show that sometimes, you can have a great day and things can pay off.”