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Mammal study explains 'why females live longer' – BBC News

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A new study that looks at lifespan in wild mammals shows that females live substantially longer than males.

The research finds that, on average, females live 18.6% longer than males from the same species.

This is much larger than the well-studied difference between men and women, which is around 8%.

The scientists say the differences in these other mammals are due to a combination of sex-specific traits and local environmental factors.

In every human population, women live longer than men, so much so that nine out of 10 people who live to be 110 years old are female.

This pattern, researchers say, has been consistent since the first accurate birth records became available in the 18th Century.

While the same assumption has been held about animal species, large-scale data on mammals in the wild has been lacking,

Now, an international team of researchers has examined age-specific mortality estimates for a widely diverse group of 101 species.

In 60% of the analysed populations, the scientists found that females outlived the males – on average, they had a lifespan that’s 18.6% longer than males.

“The magnitude of lifespan and ageing across species is probably an interaction between environmental conditions and sex-specific genetic variations,” said lead author Dr Jean-Francois Lemaître, from the University of Lyon, France.

He gives the example of bighorn sheep for which the researchers had access to good data on different populations.

Where natural resources were consistently available there was little difference in lifespan. However, in one location where winters were particularly severe, the males lived much shorter lives.

“Male bighorn sheep use lots of resources towards sexual competition, towards the growth of a large body mass, and they might be more sensitive to environmental conditions,” said Dr Lemaître.

“So clearly the magnitude of the difference in lifespan is due to the interaction of these sex-specific genetics, the fact that males devote more resources towards specific functions compared with females, and to the local environmental conditions.”

Even if females lived longer than males, the team found that it did not mean that the risks of dying are increasing more in males than females as they get older. The expected male mortality is always higher, but the rate of mortality is about the same in both sexes as they age.

One recent study in this field suggested that the genetic differences between males and females were key.

In humans, our cells contain different chromosomes, depending on sex. Females have two X chromosomes while males have an X and a Y. The theory is that the extra X in women has a protective effect against harmful mutations and that this holds true in other species.

The author of the new study on mammals says that both pieces of research are complementary.

“They show that in XX or XY systems, the XX, or the female, lives longer, so clearly there is an effect of sex chromosomes,” said Dr Lemaître.

“What we show in our paper is that the difference is very variable across species, meaning there are other factors that need to be considered to explain this variability.”

The study has been published in Proceedings of the National Academy of Sciences.

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CINDY DAY: Venus shows us the way – The Telegram

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Early spring days are not always the brightest here on the coast and this past week certainly didn’t go against the grain. 

A huge blanket of heavy, low cloud positioned itself between us and sun.  Backyard astronomers didn’t fare any better but that’s about to change and the timing is great. 

This weekend, we’ll be treated to something quite special – something that only happens once every eight years and it will be best seen this evening.

I’m not an expert, but thanks to mom’s love of the night sky, I can identify planets, some star clusters and constellations. One of my favourites is the Pleiades. 

The Pleiades is an open star cluster containing middle-aged stars located in the constellation of Taurus. It is among the star clusters nearest Earth and is the cluster most obvious to the naked eye in the night sky. The brightest stars look a bit like a small “Big Dipper.” Even so, it can be tricky to locate.

Look for Venus in the western sky – after sunset but before it sets at 11 p.m. ADT.

 

Venus to the rescue! One of the easiest astronomical objects to identify in the night sky is the planet Venus – the second planet from the sun and the second-brightest natural object in the night sky after the moon.

Tonight, brilliant Venus will introduce us to the cluster of stars. The Pleiades have another name, which I love – the Seven Sisters. In Greek mythology, they are the seven daughters of the Titan Atlas and the Oceanid Pleione: Maia, Electra, Taygete, Celaeno, Alcyone, Sterope, and Merope.

This showy open cluster contains more than a thousand stars that are loosely bound by gravity, but it is visually dominated by a handful of its seven  brightest members – the Seven Sisters.

This is the perfect time to let the universe remind us of its wonders.



Cindy Day is the chief meteorologist for SaltWire Network

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NASA astronauts share their workout routine aboard the ISS to help motivate those on Earth living in isolation amid the coronavirus pandemic – msnNOW

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Billions of people are under lockdown orders to limit the spread of coronavirus, forcing them to find creative ways to stay in shape at home -and a group who spends months in isolation has come to their aid.

Astronauts aboard the International Space Station (ISS) posted a video on Twitter sharing their workout routine from 250 miles above the Earth.

NASA’s Jessica Meir took the public on a tour of their makeshift equipment which includes a vacuum system that is similar to free-weights, a treadmill with bungee cords and a stationary bike without a seat or handlebars.

‘Studies have shown that exercise is vital only to your physical health but also to your mental well-being,’ Meir said in the clip.

‘You may need to get a little bit creative to get that heart rate elevated while at home without heading to the gym, but we are confident you can come up with something.’

The coronavirus, which began in China December 2019, has forced around 20 percent of the world’s population into their homes either by way of stay-at-home or quarantines.

Nearly every country has been infected by the disease – there are more than one million cases in the world and the death toll has surpassed 55,700.

During this anxious time, many are looking for ways relieve stress and have turned to exercise.

However, being stuck at home can be difficult to get a great workout in, but Meir and her team have shared their routine while they are also spending time in isolation. 

Exercising in space poses unique challenges, but without exercise, astronauts can lose up to 15 percent of their muscle mass, some of it permanently.

Aboard the ISS is the Advanced Resistive Exercise Device (aRED), which, according to Meir, is the crew’s one-stop weight machine that uses two large vacuum tubes to generate the resistance.

The system uses a piston and flywheel system to simulate free-weight exercises in normal gravity to work all the major muscle groups through squats, dead lifts and calf raises.

Astronauts have reported see similar results to using free-weights.

‘While aRED’s primary goal is to maintain muscle strength and mass, resistive exercise also helps astronauts increase endurance for physically demanding tasks such as space walks, NASA explained in a statement.

The crew also needs to do some cardiovascular exercises, which is done using a small treadmill or stationary bike –but they are different than what you see at your own gym.

The treadmill aboard the ship is designed to allow astronauts to run without vibrating the equipment.

It is also equip with a harness that is connected to bungee cords, which keep the runner in place while in the microgravity.

‘One of the interesting thing we like to point to people on the ground that it is a bicycle, but we don’t’ have a seat and we don’t have handle bars,’ Meir said as she strapped herself into the bike and grabbed onto handles attached to the wall. 

NASA astronaut Scott Kelly who spent nearly a year on the ISS has also shared his best advice for surviving isolation.

The retired astronaut spent a total of 520 days on the space station, with his longest mission lasting 340 days from March 27, 2015 to March 1, 2016.

Kelly says the one thing he missed the most during his year on the ISS was being able to go outside, particularly the smell, sound and sights of nature.

He says people should also follow a schedule, have a hobby, keep a journal, binge-watch TV series and ‘get plenty of sleep’ when forced to stay indoors.

He said other astronauts on the ISS would play recordings of Earth sounds, like birds and resulting trees on a loop to bring themselves back to Earth.

‘I actually started to crave nature – the color green, the smell of fresh dirt, and the feel of warm sun on my face,’ he told the New York Times.

‘You don’t need to work out two and a half hours a day, as astronauts do, but getting moving once a day should be part of your quarantine schedule (just stay at least six feet away from others),’ he added.

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Earth Is Vibrating Substantially Less Because There's So Little Activity Right Now – ScienceAlert

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Flights are grounded. Fewer trains are running. Rush hour is gone. The world – particularly in cities – is looking drastically different during the ongoing coronavirus pandemic.

According to seismologists, that drastic reduction in human hustle and bustle is causing the Earth to move substantially less. The planet is ‘standing still’.

Thomas Lecocq, a geologist and seismologist at the Royal Observatory in Belgium, noticed that the country’s capital Brussels is experiencing a 30 to 50 percent reduction in ambient seismic noise since the lockdowns began, as CNN reports.

That means data collected by seismologists is becoming more accurate, capable of detecting even the smallest tremors – despite the fact that many of the scientific instruments in use today are near city centers.

“You’ll get a signal with less noise on top, allowing you to squeeze a little more information out of those events,” Andy Frassetto, a seismologist at the Incorporated Research Institutions for Seismology in Washington DC told Nature.

Researchers in Los Angeles and in West London, UK noticed a similar trend.

But seismologists collecting data from remote stations far away from human civilization might not see a change at all, according to Nature.

Regardless, a significant drop in seismic noise also shows that we’re at least doing one thing right during the current pandemic: staying in the safety of our own homes as we wait for the virus to run its course.

This article was originally published by Futurism. Read the original article.

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