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NIAID via Flickr Creative Commons // CC BY 2.0
NIAID via Flickr Creative Commons // CC BY 2.0

We’ve Been Seriously Underestimating the Number of Viruses on Earth

NIAID via Flickr Creative Commons // CC BY 2.0
NIAID via Flickr Creative Commons // CC BY 2.0

We don’t mean to alarm you, but there are viruses everywhere—and they have been tricky to categorize. (They're not all bad! We’re not even sure if they’re alive!) The most recent report, published August 17 in Nature, has found that there are exponentially more viruses on this planet than we ever believed. 

Viruses’ slippery nature can also make them difficult to understand. Because they can’t reproduce outside of a living host, scientists have often relied upon those hosts as a starting point. They culture hosts and viruses in the lab and painstakingly monitor their interactions. But the massive computing power of modern technology has offered virologists another way.

Researchers from the Department of Energy’s (DOE) Joint Genome Institute created a new model for counting viruses. They tapped into the DOE’s Genomes OnLine Database (GOLD), which offers complete genetic data on tens of thousands of plants, animals, bacteria, fungi, and viruses. They were especially interested in metagenomes—that is, all of the genetic material in a sampled environment.

The team dug through 5 terabytes of metagenomic information from more than 3000 different environments, looking for viruses and their hosts, then compared their findings with the genetic codes of known species. The samples came from 10 different habitat types, including the ocean, the soil, thermal springs, plants, and the human body.

They found what amounts to a viral cornucopia. Those 3042 samples were home to at least 125,000 different viruses, one of which is the largest-known bacteriophage (bacteria-eating) virus ever seen. Half of the viruses could be sorted into family groups, and many of those groups were genetically unlike any viruses known today. The researchers say their findings multiply the number of known viruses in our planet's virome, or viral ecosystem, by a factor of 16. 

The research also yielded some interesting insights about viruses’ hosts. Some researchers have argued that any cellular organism, including a bacterium, is susceptible to parasite infection. The new findings seem to support that hypothesis; not only did they double the number of known microbe phyla (groups) that can be infected, but they even identified viruses that can infect more than one phylum.

The team then mapped their findings, and saw that similar viruses tended to prefer similar types of habitats even when they occupied different parts of the globe. Perhaps most surprising of all, the researchers say, was discovering that unrelated people in different places can share very similar viral ecosystems.

Image credit: Paez-Espino et al., 2016. Nature

“Ultimately, large-scale computational exploration of uncharted viral sequence space will assist in addressing the remaining mysteries of viral ecology,” they write.

We can hope.

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New Patient Test Could Suggest Whether Therapy or Meds Will Work Better for Anxiety
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Like many psychological disorders, there's no one-size-fits-all treatment for patients with anxiety. Some might benefit from taking antidepressants, which boost mood-affecting brain chemicals called neurotransmitters. Others might respond better to therapy, and particularly a form called cognitive behavioral therapy, or CBT.

Figuring out which form of treatment works best often requires months of trial and error. But experts may have developed a quick clinical test to expedite this process, suggests a new study published in the journal Neuropsychopharmacology.

Researchers at the University of Illinois at Chicago have noted that patients with higher levels of anxiety exhibit more electrical activity in their brains when they make a mistake. They call this phenomenon error-related negativity, or ERN, and measure it using electroencephalography (EEG), a test that records the brain's electric signals.

“People with anxiety disorders tend to show an exaggerated neural response to their own mistakes,” the paper’s lead author, UIC psychiatrist Stephanie Gorka, said in a news release. “This is a biological internal alarm that tells you that you've made a mistake and that you should modify your behavior to prevent making the same mistake again. It is useful in helping people adapt, but for those with anxiety, this alarm is much, much louder.”

Gorka and her colleagues wanted to know whether individual differences in ERN could predict treatment outcomes, so they recruited 60 adult volunteers with various types of anxiety disorders. Also involved was a control group of 26 participants with no history of psychological disorders.

Psychiatrists gauged subjects’ baseline ERN levels by having them wear an EEG cap while performing tricky computer tasks. Ultimately, they all made mistakes thanks to the game's challenging nature. Then, randomized subjects with anxiety disorders were instructed to take an SSRI antidepressant every day for three months, or receive weekly cognitive behavioral therapy for the same duration. (Cognitive behavioral therapy is a type of evidence-based talk therapy that forces patients to challenge maladaptive thoughts and develop coping mechanisms to modify their emotions and behavior.)

After three months, the study's patients took the same computer test while wearing EEG caps. Researchers found that those who'd exhibited higher ERN levels at the study's beginning had reduced anxiety levels if they'd been treated with CBT compared to those treated with medication. This might be because the structured form of therapy is all about changing behavior: Those with enhanced ERN might be more receptive to CBT than other patients, as they're already preoccupied with the way they act.

EEG equipment sounds high-tech, but it's relatively cheap and easy to access. Thanks to its availability, UIC psychiatrists think their anxiety test could easily be used in doctors’ offices to measure ERN before determining a course of treatment.

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Newly Discovered 350-Year-Old Graffiti Shows Sir Isaac Newton's Obsession With Motion Started Early
Hulton Archive//Getty Images
Hulton Archive//Getty Images

Long before he gained fame as a mathematician and scientist, Sir Isaac Newton was a young artist who lacked a proper canvas. Now, a 350-year-old sketch on a wall, discovered at Newton’s childhood home in England, is shedding new light on the budding genius and his early fascination with motion, according to Live Science.

While surveying Woolsthorpe Manor, the Lincolnshire home where Newton was born and conducted many of his most famous experiments, conservators discovered a tiny etching of a windmill next to a fireplace in the downstairs hall. It’s believed that Newton made the drawing as a boy, and may have been inspired by the building of a nearby mill.

A windmill sketch, believed to have been made by a young Sir Isaac Newton at his childhood home in Lincolnshire, England.
A windmill sketch, believed to have been made by a young Sir Isaac Newton at his childhood home in Lincolnshire, England.
National Trust

Newton was born at Woolsthorpe Manor in 1642, and he returned for two years after a bubonic plague outbreak forced Cambridge University, where he was studying mechanical philosophy, to close temporarily in 1665. It was in this rural setting that Newton conducted his prism experiments with white light, worked on his theory of “fluxions,” or calculus, and famously watched an apple fall from a tree, a singular moment that’s said to have led to his theory of gravity.

Paper was a scarce commodity in 17th century England, so Newton often sketched and scrawled notes on the manor’s walls and ceilings. While removing old wallpaper in the 1920s and '30s, tenants discovered several sketches that may have been made by the scientist. But the windmill sketch remained undetected for centuries, until conservators used a light imaging technique called Reflectance Transformation Imaging (RTI) to survey the manor’s walls.

Conservators using light technology to survey the walls of Woolsthorpe Manor,  the childhood home of Sir Isaac Newton.
A conservator uses light technology to survey the walls of Woolsthorpe Manor, the childhood home of Sir Isaac Newton.
National Trust

RTI uses various light conditions to highlight shapes and colors that aren’t immediately visible to the naked eye. “It’s amazing to be using light, which Newton understood better than anyone before him, to discover more about his time at Woolsthorpe,” conservator Chris Pickup said in a press release.

The windmill sketch suggests that young Newton “was fascinated by mechanical objects and the forces that made them work,” added Jim Grevatte, a program manager at Woolsthorpe Manor. “Paper was expensive, and the walls of the house would have been repainted regularly, so using them as a sketchpad as he explored the world around him would have made sense," he said.

The newly discovered graffiti might be one of many hidden sketches drawn by Newton, so conservators plan to use thermal imaging to detect miniscule variations in the thickness of wall plaster and paint. This technique could reveal even more mini-drawings.

[h/t Live Science]

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