ريتشارد دوكنز's Blog, page 678

Are Viruses Alive?

Julie McMahon

By Grennan Milliken

Influenza, SARS, Ebola, HIV, the common cold. All of us are quite familiar with these names. They are viruses—a little bit of genetic material (DNA or RNA) encapsulated in a protein coat. But what we don’t really understand, and what scientists have struggled with since the study of virology began, is whether viruses are actually living or not. A paper published today in Science Advancesjust might change that. By creating a reliable method of studying viruses’ long evolutionary history—hitherto nearly impossible—researchers have found new evidence that strongly suggests viruses are indeed living entities.

Scientists have long argued that viruses are nonliving, that they are bits of DNA and RNA shed from other cells. Indeed, based on everything else we know about what it takes to qualify as life, a virus doesn’t seem to fit the bill. There are many life processes, such as the ability to metabolize, that viruses do not do. Viruses seem to carry out only one life process, reproduction, but even then, individual viruses don’t carry translational machinery, namely, the proteins needed to read their DNA and RNA and build new viruses. They invade a cell and hijack its genetic tools to do it for them.

But within the last decade, developments in virology have started to reveal more and more that viruses might in fact be alive. One was the discovery of mimiviruses, giant viruses with large genomic libraries that are even bigger than some bacteria. To put this in perspective, some viruses, like the Ebola virus, have as few as seven genes. Some of these giants have genes for the proteins that are required for translation—those readers of DNA and RNA that in turn build new viruses. This throws the lack of translational machinery argument for classifying them as nonliving on its head.

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Paraplegic man walks with own legs again

Shutterstock

By Ian Sample

A man who lost the use of his legs to a spinal cord injury has walked again after scientists rerouted signals from his brain to electrodes on his knees. The 26-year-old American has used a wheelchair for five years after an accident left him paralysed from the waist down. Doctors said he was the first person with paraplegia caused by a spinal injury to walk without relying on robotic limbs that are controlled manually.

The man walked a 3.5-metre course after being fitted with an electrode cap that picks up brain waves and beams them wirelessly to a computer, which decipher the waves as an intention to stand still or walk. The relevant command is then sent to a microcontroller on the man’s belt, and on to nerves that trigger muscles to move the legs.

The patient needed intensive training to generate recognisable walking signals in his brain, and to learn how to use the device to put one foot in front of the other. He also needed extensive physical training to build up the muscle tone in his legs.

“Even after years of paralysis, the brain can still generate robust brain waves that can be harnessed to enable basic walking,” said Dr An Do at the University of California at Irvine, who co-led the proof-of-concept study.

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‘Take what you need and leave the rest’: why atheists love Pope Francis

Saul Loeb/AFP/Getty Images

By Alana Massey

“If it’s interesting, pay attention. If you think it’s nonsense, look at other things.”

This was the Dalai Lama’s instruction to 65,000 people in Central Park in September 2003. The crowd likely heeded this command: though it featured its fair share of Tibetan Buddhists, many thousands came to see him out of curiosity, and out of respect for his universal moral leadership.

This week, when Pope Francis addresses an estimated million people in Philadelphia, his attendance is also likely to be more diverse than usual.

Though Catholics from around the world will descend on the US northeast to listen to their leader, crowds will be infiltrated by non-religious admirers. Quotable because of the simplicity of his speech and relatable because of the plainness of his gestures, Pope Francis ignites unprecedented secular excitement. He is admired in spite of his Catholicism, rather than because of it.

“I have not been a fan of the Catholic church for a long time. I would have avoided seeing a pope at all costs in the past. But I just think this is someone who is so enlightened and progressive,” said Dan Nainan, a comedian and corporate speaker who has tickets to attend mass in Central Park.

Nainan mentioned the pope’s remarks on LGBT issues and women as some of the more surprising comments that triggered his change of heart: “He is proposing things that you could never dream of coming from the Catholic Church. It isn’t enough for me to convert to Catholicism, but I’m excited to hear what he has to say.”

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A painful admission for non-believers

iStock

By Christopher Leelum

The word “confess” usually involves reluctantly admitting some wrongdoing — a secret, a lie, a crime.

So when Arian Foster, the star NFL running back for the Houston Texans, appeared in ESPN The Magazine under the headline “The Confession of Arian Foster,” I thought he might be conceding to being a steroid-using North Korean national living here illegally.

No, he’s an atheist.

The fact that this revelation of a simple personal belief came with a “confession” headline was troubling, because the discussion transcends that.

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Epic Space Rescues ft. BrainCraft

Follow me over to BrainCraft and subscribe! https://www.youtube.com/watch?v=Y19fwDEfQ8E

In The Martian, astronaut Mark Watney is stranded alone on Mars and must be rescued. It is an exciting tale of what could happen once humans start traveling to the red planet. Let’s take a look back at the most epic space rescues in history.

instagram.com/thephysicsgirl

facebook.com/thephysicsgirl

twitter.com/thephysicsgirl

physicsgirl.org

Physics Girl has joined PBS Digital Studios! https://www.youtube.com/user/pbsdigitalstudios

RESOURCES

Hubble Mission STS-31

https://www.youtube.com/watch?v=9OYdkxwcrqk

Apollo 13 footage: A-V Corporation, Houston Texas for NASA

Hubble in Space animation: ESA/Hubble

STS-61 Footage: NASA

Martian Trailer

https://www.youtube.com/watch?v=ej3ioOneTy8

Soyuz-T 13 Images: http://epizodsspace.airbase.ru/bibl/savinyh/v-b-k/foto1.html

http://www.spacefacts.de/graph/drawing/large/english/soyuz-t-13_recovery.htm

Stock Images and Graphics:

Pixabay, Clker.com and Shutterstock

Music:

Cy Reynolds: “Yet as Walls Give Way,” “Learning to Feel Again” https://soundcloud.com/cyrusreynolds

YouTube: “On the Bach,” “Path to Follow,”

Apple: “Ticker,” Apple Sound Effects

Imaginary Band: https://freesound.org/people/imaginaryband/sounds/79422/

New Study Suggests Viruses Are Alive, And That They Share An Ancestor With Modern Cells

Plants and Animals





Photo credit:

The diverse sizes and structures of viruses. Julie McMahon

A detailed new study of the origins of viruses lends weight to the argument that they are living cells, and offers us a reliable method to turn back the clock and track their evolution.

How Accurate Is The Martian? 9 Things The Movie Got Right And Wrong

Space





Photo credit:

Matt Damon stars as Mark Watney in The Martian. 20th Century Fox.

"The Martian" is hitting cinemas right about now, and already it is being heralded as one of the most scientifically accurate sci-fi films of all time. We’ve seen the movie, and we’ve got to say, it’s amazing how far we’ve come since "Armageddon" (shudder). NASA has been so impressed, they've been using the movie as a marketing campaign for their own, actual manned missions to Mars in the 2030s.

New Species Of Snake Discovered In Western Australia

Plants and Animals





Photo credit:

The viper-like Acanthophis cryptamydros has a diamond-shaped head and stout body. Ryan Ellis/Western Australian Museum

A new species of viper-like snake discovered in the Kimberley region of northwestern Australia is highly venomous and expertly camouflaged. Called Acanthophis cryptamydros, the Kimberley death adder is a sit-and-wait predator – ambushing frogs, lizards, and small mammals passing by. 

Hubble Zooms in on Shrapnel from an Exploded Star

By Ashley Morrow

NASA’s Hubble Space Telescope has unveiled in stunning detail a small section of the expanding remains of a massive star that exploded about 8,000 years ago.

Called the Veil Nebula, the debris is one of the best-known supernova remnants, deriving its name from its delicate, draped filamentary structures. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan.

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Robots Are Now Smart Enough to Take the SAT

Wikimedia Commons

By Alison Eck

A new software program might just be smarter than an 11th grader.

For the first time, an artificial intelligence program capable of seeing and reading has demonstrated the ability to answer geometry questionsfrom the SAT that it had not previously encountered. Though machine vision is still in its infancy—even the most sophisticated AI programs struggle to comprehend the symbolic meaning of an arrow in the context of a diagram, for example—this most recent achievement is a major step for computer scientists.

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