Category: Science

Death spiral linked to neonicotinoids expands to include farmland birds

New research has identified the world’s most widely used insecticides as the key factor in the recent reduction in numbers of farmland birds.

The finding represents a significant escalation of the known dangers of the insecticides and follows an assessment in June that warned that pervasive pollution by these nerve agents was now threatening all food production.

The neonicotinoid insecticides are believed to seriously harm bees and other pollinating insects, and a two-year EU suspension on three of the poisons began at the end of 2013. But the suspected knock-on effects on other species had not been demonstrated until now.

Peer-reviewed research, published in the leading journal Nature this Wednesday, has revealed data from the Netherlands showing that bird populations fell most sharply in those areas where neonicotinoid pollution was highest. Starlings, tree sparrows and swallows were among the most affected…

The researchers, led by Hans de Kroon, an ecologist at Radboud University, in the Netherlands, examined other possible reasons for the bird declines seen during the study period of 2003 to 2010, including intensification of farming. But high pollution by a neonicotinoid known as imidacloprid was by far the largest factor.

“It is very surprising and very disturbing,” de Kroon said. Water pollution levels of just 20 nanograms of neonicotinoid per litre led to a 30% fall in bird numbers over 10 years, but some water had contamination levels 50 times higher. “That is why it is so disturbing – there is an incredible amount of imidacloprid in the water,” he said. “And it is not likely these effects will be restricted to birds.”

De Kroon added: “All the other studies [on harm caused by neonicotinoids] build up from toxicology studies. But we approached this completely from the other end. We started with the bird population data and tried to explain the declines. Our study really makes the evidence complete that something is going on here. We can’t go on like this any more. It has to stop.”

RTFa for all the details. As a modern society I expect the Netherlands will respond to scientific studies as the peer-review process continues.

Here in the land of Tea Parties and the Best Government Money Can Buy – I am less assured of any efforts to proceed with caution and a decision process based on science. But, then – you already knew that.

Thanks, Mike

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Who would want to talk to meat?

Milky-Way

So there are 100 Earth-like planets for every grain of sand in the world. Think about that next time you’re on the beach.

Moving forward, we have no choice but to get completely speculative. Let’s imagine that after billions of years in existence, 1% of Earth-like planets develop life (if that’s true, every grain of sand would represent one planet with life on it). And imagine that on 1% of those planets, the life advances to an intelligent level like it did here on Earth. That would mean there were 10 quadrillion, or 10 million billion intelligent civilizations in the observable universe.

Moving back to just our galaxy, and doing the same math on the lowest estimate for stars in the Milky Way (100 billion), we’d estimate that there are 1 billion Earth-like planets and 100,000 intelligent civilizations in our galaxy.

SETI (Search for Extraterrestrial Intelligence) is an organization dedicated to listening for signals from other intelligent life. If we’re right that there are 100,000 or more intelligent civilizations in our galaxy, and even a fraction of them are sending out radio waves or laser beams or other modes of attempting to contact others, shouldn’t SETI’s satellite array pick up all kinds of signals?

But it hasn’t. Not one. Ever.

Where is everybody?

There are a number of answers. All speculative. A topic, in fact, that I have been discussing with a few of the folks associated with this blog…for years.

Here’s one of the best conclusions – taken from the point of view of an alien species checking out our region of the Milky Way galaxy:

“They’re made out of meat.”

“Meat?”

“Meat. They’re made out of meat.”

“Meat?”

“There’s no doubt about it. We picked up several from different parts of the planet, took them aboard our recon vessels, and probed them all the way through. They’re completely meat.”

“That’s impossible. What about the radio signals? The messages to the stars?”

“They use the radio waves to talk, but the signals don’t come from them. The signals come from machines.”

“So who made the machines? That’s who we want to contact.”

“They made the machines. That’s what I’m trying to tell you. Meat made the machines.”

“That’s ridiculous. How can meat make a machine? You’re asking me to believe in sentient meat.”

Here’s a link to the rest of this extraterrestrial discussion.

Thanks, Ursarodinia
Thanks, Mike

Corneas regrown using adult stem cells


Shutterstock

Medical researchers working with human stem cells have discovered a way to improve regrowth of corneal tissue in the human eye. Using a molecule known as ABCB5 to act as an identifying marker for rare limbal stem cells, the researchers were able to use antibodies to detect ABCB5 on stem cells in tissue from donated human eyes and use them to regrow anatomically correct, fully functional human corneas in mice…

Up until now, the use of tissue or cell transplants to help the cornea regenerate have been used, but as it was both unknown whether there were actual limbal stem cells in the grafts, or how many, the outcomes were generally inconsistent.

As a result of this recent research, transplants have now been made in mice using human ABCB5-positive limbal stem cells that resulted in the restoration and long-term maintenance of normal, transparent corneas. Control mice that received either no cells or ABCB5-negative cells failed to have their cornea restored.

“Limbal stem cells are very rare, and successful transplants are dependent on these rare cells,” said Bruce Ksander, Ph.D., of Massachusetts Eye and Ear, co-lead author on the research. “This finding will now make it much easier to restore the corneal surface. It’s a very good example of basic research moving quickly to a translational application.”…one of the first known examples of constructing tissue from an adult-derived human stem cell.

Not only a potential boon for folks with diseases of the cornea – preventing blindness or restoring sight – I imagine this should aid folks with injury-damaged corneas.

Of course, the first question from an old fart like me is – when will this be covered by my medicare insurance? Don’t need it, yet – but, cataracts are pretty much inevitable. Only a question of how many, how fast are they growing? :)

The brave new world of three-parent IVF

In August 1996, at St. Barnabas Medical Center in Livingston, N.J., a 39-year-old mechanical engineer from Pittsburgh named Maureen Ott became pregnant. Ott had been trying for almost seven years to conceive a child through in vitro fertilization. Unwilling to give up, she submitted to an experimental procedure in which doctors extracted her eggs, slid a needle through their shiny coat and injected not only her husband’s sperm but also a small amount of cytoplasm from another woman’s egg. When the embryo was implanted in Ott’s womb, she became the first woman on record to be successfully impregnated using this procedure, which some say is the root of an exciting medical advance and others say is the beginning of the end of the human species.

The fresh cytoplasm that entered Ott’s eggs (researchers thought it might help promote proper fertilization and development) contained mitochondria: bean-shaped organelles that power our cells like batteries. But mitochondria also contain their own DNA, which meant that her child could possess the genetic material of three people. In fact, the 37 genes in mitochondrial DNA pass directly from a woman’s egg into every cell of her offspring, including his or her germ cells, the sperm or eggs that eventually produce the next generation — so if Ott had a girl and the donor mitochondria injected into Ott’s egg made it into the eggs of her daughter, they could be passed along to her children. This is known as crossing the germ line…In May 1997, she gave birth to a healthy baby girl…

Two months later, her doctors published her case in the journal Lancet; soon, at least seven other U.S. clinics were doing the injection. Because the amount of donor mitochondria added to Ott’s egg was small, it was unclear how much third-party DNA would be present in the cells of her daughter. Ott says her doctors ran tests and did not find any, but it has been found in two other children born from the procedure. Although IVF drugs and devices are regulated by the Food and Drug Administration, IVF procedures (like all medical procedures) are generally not. But what media outlets came to call “three-parent babies” compelled the agency to take action. In 2001, the FDA informed IVF clinics that using a third person’s cytoplasm — and the mtDNA therein — would require an Investigational New Drug application…

Now, more than a decade later, two research groups in the United States and one in Britain each believes it has nearly enough data to begin clinical trials for a new technique based on the transfer of mitochondria — only in this case, researchers want to pair the nuclear DNA of one egg with all the mitochondria of another. Their aim is not to cure infertility. Rather, they hope to prevent a variety of devastating diseases caused by mutations in mtDNA. The new technique, which they call mitochondrial-replacement therapy, is far more advanced than the cytoplasm injection — and the researchers have studied the procedure’s impact on animals and human cells up to a pivotal point: They have created what appear to be viable three-parent embryos. They have yet to implant one in a woman, though…

Is our fear of crossing the germ line causing us to block a technology that could improve people’s lives, and if so, is the fear itself a thing we should also be afraid of?

RTFA. I’ve barely introduced the topic. You can presume my personal opinion would not be acceptable to any flavor of the FDA. Crass politics aside – unlikely in the USA – science moves ahead in tiny conservative steps. Bodies like the FDA are more conservative than that.

I think consenting adults have the right and freedom to participate in an unlimited range of experiments excepting those designed to destroy humans, individually and as a species. Our government and military already have that market cornered, anyway.

Like I said. RTFA. Think about what you think.

An algae that switches its internal quantum computer on and off

Scientists have shown that certain algae which use quantum effects to optimize photosynthesis are also capable of switching it off. It’s a discovery that could lead to highly efficient organic solar cells and quantum-based electronics.

Like quantum computers, some organisms are capable of scanning all possible options in order to choose the most efficient path or solution. For plants and some photosynthetic algae, this means the ability to make the most of the energy they receive and then deliver that energy from leaves with near perfect efficiency. This effect, called quantum decoherence, is what allows some algae to survive in very low levels of light.

Recently, scientists from the UNSW School of Physics studied one of these algae, a tiny single-celled organism called cryptophytes. They typically live at the bottom of pools of water, or under thick ice, where light is scarce. The researchers found that there’s a class of cryptophytes in which quantum decoherence is switched off, and it’s on account of a single genetic mutation that alters the shape of a light-harvesting protein.

In quantum mechanics, a system is coherent when all quantum waves are in step with each other. When it’s coherent, it can exist in many different states simultaneously, an effect known as superposition.

The researchers used x-ray crystallography to determine the crystal structure of the light-harvesting complexes from three different species. Two cryptophyte species had a mutation that led to the insertion of an extra amino acid that changes the structure of the protein complex, which disrupts decoherence.

The next step for the scientists will be to determine whether the switching effect is assisting the algae’s survival. What’s more, further understanding of this phenomenon could eventually lead to technological advances, such as better organic solar cells and quantum-based electronic devices.

I’m beginning to worry that quantum mechanics is starting to rub off on my little gray cells. This is making sense to me – and it only took five or six decades.

Thanks, Mike

A diamond in space — the size of Earth


B.Saxton (NRAO/AUI/NSF)

“It’s a really remarkable object,” said David Kaplan, a professor at the University of Wisconsin-Milwaukee. “These things should be out there, but because they are so dim they are very hard to find.”

Kaplan and his colleagues found this stellar gem using the National Radio Astronomy Observatory’s (NRAO) Green Bank Telescope (GBT) and Very Long Baseline Array (VLBA), as well as other observatories.

White dwarfs are the extremely dense end-states of stars like our Sun that have collapsed to form an object approximately the size of Earth. Composed mostly of carbon and oxygen, white dwarfs slowly cool and fade over billions of years. The object in this new study is likely the same age as the Milky Way, approximately 11 billion years old…

The pulsar companion to this white dwarf, dubbed PSR J2222-0137, was the first object in this system to be detected. It was found using the GBT by Jason Boyles, then a graduate student at West Virginia University in Morgantown.

These first observations revealed that the pulsar was spinning more than 30 times each second and was gravitationally bound to a companion star, which was initially identified as either another neutron star or, more likely, an uncommonly cool white dwarf. The two were calculated to orbit each other once every 2.45 days…

Knowing its location with such high precision and how bright a white dwarf should appear at that distance, the astronomers believed they should have been able to observe it in optical and infrared light…Remarkably, neither the Southern Astrophysical Research (SOAR) telescope in Chile nor the 10-meter Keck telescope in Hawaii was able to detect it…

The researchers calculated that the white dwarf would be no more than a comparatively cool 3,000 degrees Kelvin (2,700 degrees Celsius). Our Sun at its center is about 5,000 times hotter.

Astronomers believe that such a cool, collapsed star would be largely crystallized carbon, not unlike a diamond. Other such stars have been identified and they are theoretically not that rare, but with a low intrinsic brightness, they can be deucedly difficult to detect. Its fortuitous location in a binary system with a neutron star enabled the team to identify this one.

If it was just coal, I could see Congress voting funds to go out and bring back chunks to, say, West Virginia.

V838 Light Echo — The Movie

Click to enlarge

What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon suddenly became one of the brightest stars in the entire Milky Way Galaxy. Then, just a few months later, it faded.

A stellar flash like this has never been seen before — supernovas and novas expel a tremendous amount of matter out into space. Although the V838 Mon flash appeared to expel some material into space, what is seen in the above eight-frame movie, interpolated for smoothness, is actually an outwardly moving light echo of the flash. The actual time-span of the above movie is from 2002, when the flash was first recorded, to 2006.

In a light echo, light from the flash is reflected by successively more distant ellipsoids in the complex array of ambient interstellar dust that already surrounded the star. Currently, the leading model for V838’s outburst was the orbital decay and subsequent merging of two relatively normal stars. V838 Mon lies about 20,000 light years away toward the constellation of Monoceros, while the largest light echo above spans about six light years in diameter.

Thanks, Ursarodinia

Achilles’ heel in defensive barrier of antibiotic-resistant bacteria discovered

New research published today in the journal Nature reveals an Achilles’ heel in the defensive barrier which surrounds drug-resistant bacterial cells.

The findings pave the way for a new wave of drugs that kill superbugs by bringing down their defensive walls rather than attacking the bacteria itself. It means that in future, bacteria may not develop drug-resistance at all.

The discovery doesn’t come a moment too soon. The World Health Organization has warned that antibiotic-resistance in bacteria is spreading globally, causing severe consequences. And even common infections which have been treatable for decades can once again kill.

Researchers investigated a class of bacteria called ‘Gram-negative bacteria’ which is particularly resistant to antibiotics because of its cells’ impermeable lipid-based outer membrane…

Until now little has been known about exactly how the defensive barrier is built. The new findings reveal how bacterial cells transport the barrier building blocks (called lipopolysaccharides) to the outer surface.

Group leader Prof Changjiang Dong, from UEA’s Norwich Medical School, said: “We have identified the path and gate used by the bacteria to transport the barrier building blocks to the outer surface. Importantly, we have demonstrated that the bacteria would die if the gate is locked…”

Lead author PhD student Haohao Dong said: “The really exciting thing about this research is that new drugs will specifically target the protective barrier around the bacteria, rather than the bacteria itself.

“Because new drugs will not need to enter the bacteria itself, we hope that the bacteria will not be able to develop drug resistance in future.”

Bravo! I look forward to seeing how this new information will be introduced to the mainstream of disease treatments.

Finding a key mechanism in antibiotic resistance, using that information to destroy that defense mechanism, working backwards to restore efficacy and working forwards to include that capability in next-gen medications is a boon.