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Shellfish Biotoxins in the Pacific Region | Fisheries and Oceans Canada

Shellfish Biotoxins in the Pacific Region | Fisheries and Oceans Canada | Fragments of Science | Scoop.it

In B.C., the Canadian Food Inspection Agency (CFIA) is responsible for analysing samples of shellfish for paralytic shellfish poisoning toxin (PSP - saxitoxins) and amnesic shellfish poisoning (ASP - domoic acid). The action levels for PSP and ASP are 80 micrograms per 100 g of meat and 20 ppm of domoic acid respectively.

As the basis of the marine biotoxin monitoring program in the Pacific Region, large mussels are hung in plastic mesh sacks in shellfish growing areas (in addition to a lesser number of commercial samples of all species). Samples are withdrawn on a weekly or biweekly basis and shipped to the CFIA laboratory for analysis. Shellfish species differ in their tendencies to accumulate and eliminate marine biotoxins in their tissues. Mussels tend to be indiscriminate feeders of phytoplankton and are therefore much quicker to pick up biotoxins than many other shellfish species. The levels of biotoxin in mussels are frequently up to 10 times higher than oysters and manila or littleneck clams growing in the same area. This allows the CFIA to recommend harvest restrictions (eg. area closures) to Fisheries and Oceans Canada while species other than mussels, such as clams, oysters and scallops, are still safe. Mussels also tend to rid their tissues of biotoxins faster than other species. Therefore, although harvest restrictions are usually based on mussel analysis results, samples of the other species in the area are tested before the harvest restrictions are lifted.

 

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Fragments of Science
The history, present and future and nature of science and their relationship
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Hubble weighs in on mass of 3 million billion suns

Hubble weighs in on mass of 3 million billion suns | Fragments of Science | Scoop.it
In 2014, astronomers using the NASA/ESA Hubble Space Telescope found that this enormous galaxy cluster contains the mass of a staggering three million billion suns. Known officially as ACT-CLJ0102-4915, it is the largest, hottest, and brightest X-ray galaxy cluster ever discovered in the distant universe.
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How massive is Supermassive? Astronomers measure more black holes, farther away

How massive is Supermassive? Astronomers measure more black holes, farther away | Fragments of Science | Scoop.it
Today, astronomers from the Sloan Digital Sky Survey (SDSS) announced new measurements of the masses of a large sample of supermassive black holes far beyond the local Universe.

The results, being presented at the American Astronomical Society (AAS) meeting in National Harbor, Maryland and published in the Astrophysical Journal, represent a major step forward in our ability to measure supermassive black hole masses in large numbers of distant quasars and galaxies.

"This is the first time that we have directly measured masses for so many supermassive black holes so far away," says Catherine Grier, a postdoctoral fellow at the Pennsylvania State University and the lead author of this work. "These new measurements, and future measurements like them, will provide vital information for people studying how galaxies grow and evolve throughout cosmic time."

Supermassive black holes (SMBHs) are found in the centers of nearly every large galaxy, including those in the farthest reaches of the Universe. The gravitational attraction of these supermassive black holes is so great that nearby dust and gas in the host galaxy is inexorably drawn in. The infalling material heats up to such high temperatures that it glows brightly enough to be seen all the way across the Universe. These bright disks of hot gas are known as "quasars," and they are clear indicators of the presence of supermassive black holes. By studying these quasars, we learn not only about SMBHs, but also about the distant galaxies that they live in. But to do all of this requires measurements of the properties of the SMBHs, most importantly their masses.

The problem is that measuring the masses of SMBHs is a daunting task. Astronomers measure SMBH masses in nearby galaxies by observing groups of stars and gas near the galaxy center—however, these techniques do not work for more distant galaxies, because they are so far away that telescopes cannot resolve their centers. Direct SMBH mass measurements in galaxies farther away are made using a technique called "reverberation mapping."
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Organic solar cells as an alternative to conventional solar cells

Organic solar cells as an alternative to conventional solar cells | Fragments of Science | Scoop.it
Organic solar cells could be an inexpensive and versatile alternative to inorganic solar cells. However, their low efficiencies and limited lifetimes currently render them impractical for commercial use.
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Device creates negative mass—and a novel way to generate lasers

Device creates negative mass—and a novel way to generate lasers | Fragments of Science | Scoop.it
Most objects react in predictable ways when force is applied to them—unless they have "negative mass." And then they react exactly opposite from what you would expect.

Now University of Rochester researchers have succeeded in creating particles with negative mass in an atomically thin semiconductor, by causing it to interact with confined light in an optical microcavity.

This alone is "interesting and exciting from a physics perspective," says Nick Vamivakas, an associate professor of quantum optics and quantum physics at Rochester's Institute of Optics. "But it also turns out the device we've created presents a way to generate laser light with an incrementally small amount of power."

The device, described in Nature Physics, consists of two mirrors that create an optical microcavity, which confines light at different colors of the spectrum depending on how the mirrors are spaced.

Researchers in Vamivakas' lab, including co-lead authors Sajal Dhara (now with the Indian Institute of Technology) and Ph.D. student Chitraleema Chakraborty, embedded an atomically thin molybdenum diselenide semiconductor in the microcavity.

The semiconductor was placed in such a way that its interaction with the confined light resulted in small particles from the semiconductor—called excitons—combining with photons from the confined light to form polaritons.

"By causing an exciton to give up some of its identity to a photon to create a polariton, we end up with an object that has a negative mass associated with it," Vamivakas explains. "That's kind of a mind-bending thing to think about, because if you try to push or pull it, it will go in the opposite direction from what your intuition would tell you."
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Chess’s New Best Player Is A Fearless, Swashbuckling Algorithm

Chess’s New Best Player Is A Fearless, Swashbuckling Algorithm | Fragments of Science | Scoop.it
DeepMind was also responsible for the program AlphaGo, which has bested the top humans in Go, that other, much more complex ancient board game, to much anguish and consternation. An early version of AlphaGo was trained, in part, by human experts’ games — tabula inscripta. Later versions, including AlphaZero, stripped out all traces of our history.

“For a while, for like two months, we could say to ourselves, ‘Well, the Go AI contains thousands of years of accumulated human thinking, all the rolled up knowledge of heuristics and proverbs and famous games,’” Frank Lantz, the director of NYU’s Game Center, told me. “We can’t tell that story anymore. If you don’t find this terrifying, at least a little, you are made of stronger stuff than me. I find it terrifying, but I also find it beautiful. Everything surprising is beautiful in a way.”
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Origins of photosynthesis in plants dated to 1.25 billion years ago

Origins of photosynthesis in plants dated to 1.25 billion years ago | Fragments of Science | Scoop.it
The world's oldest algae fossils are a billion years old, according to a new analysis by earth scientists at McGill University. Based on this finding, the researchers also estimate that the basis for photosynthesis in today'
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'Quantum material' has shark-like ability to detect small electrical signals

'Quantum material' has shark-like ability to detect small electrical signals | Fragments of Science | Scoop.it
A "quantum material" that mimics a shark's ability to detect the minute electric fields of small prey has been shown to perform well in ocean-like conditions, with potential applications from defense to marine biology.

The material maintains its functional stability and does not corrode after being immersed in saltwater, a prerequisite for ocean sensing. Surprisingly, it also functions well in the cold, ambient temperatures typical of seawater, said Shriram Ramanathan, a Purdue professor of materials engineering.

Such a technology might be used to study ocean organisms and ecosystems and to monitor the movement of ships for military and commercial maritime applications.

"So, it has potentially very broad interest in many disciplines," said Ramanathan, who led research to develop the sensor, working with a team that included Purdue postdoctoral research associate Zhen Zhang and graduate student Derek Schwanz.
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Atoms rearrange in electrolyte and control ion flow under tough conditions

Atoms rearrange in electrolyte and control ion flow under tough conditions | Fragments of Science | Scoop.it
Minerals that make up rocks and soils are thrown out of equilibrium when the chemistry of their surroundings changes. Shifts in pH or the concentration of ions in water make minerals dissolve, grow, or react in other ways. These reactions are influenced by the arrangement of atoms at the interface—where minerals and water touch. Historically, it has been hard to study these structures while reactions are proceeding because the interface is constantly changing, limiting our understanding of how the structures control reaction speed.

Now, a team led by Dr. Kevin Rosso at DOE's Pacific Northwest National Laboratory (PNNL) achieved the first 3-D view of the atomic structure at the interface of water and the mineral hematite as the reactions occur. The new view showed how the interfacial structure is different while it's reacting, and how these differences might control the flow of ions into the environment.
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Spaghetti-like, DNA 'noodle origami' the new shape of things to come for nanotechnology

Spaghetti-like, DNA 'noodle origami' the new shape of things to come for nanotechnology | Fragments of Science | Scoop.it
For the past few decades, scientists have been inspired by the blueprint of life, DNA, as the shape of things to come for nanotechnology.

This burgeoning field is called DNA origami. Scientist borrowed its moniker from the paper artists who conjure up birds, flowers and planes from imaginatively folding a single sheet of paper.

Similarly, DNA origami scientists are dreaming up a variety of shapes —-at a scale one thousand times smaller than a human hair—-that they hope will one day revolutionize computing, electronics and medicine.

Now, a team of Arizona State and Harvard scientists has invented a major new advance in DNA nanotechnology. Dubbed "single-stranded origami," their new strategy uses one long, thin noodle-like strand of DNA, or its chemical cousin RNA, that can self-fold ——without even a single knot —-into the largest, most complex structures to date.

And, the strands forming these structures can be made inside living cells or using enzymes in a test tube, allowing scientists the potential to plug-and-play with new designs and functions for nanomedicine——like tiny, nanobots playing doctor and delivering drugs within cells to the site of injury.

"I think this is an exciting breakthrough, and a great opportunity for synthetic biology as well," said Hao Yan, a co-inventor of the technology, director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, and the Milton Glick Professor in the School of Molecular Sciences.
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Complete design of a silicon quantum computer chip unveiled

Complete design of a silicon quantum computer chip unveiled | Fragments of Science | Scoop.it
Research teams all over the world are exploring different ways to design a working computing chip that can integrate quantum interactions. Now, Australian and Dutch engineers believe they have cracked the problem, reimagining the silicon microprocessors we know to create a complete design for a quantum computer chip that can be manufactured using mostly standard industry processes and components.
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A better way to weigh millions of solitary stars

A better way to weigh millions of solitary stars | Fragments of Science | Scoop.it
Astronomers have come up with a new and improved method for measuring the masses of millions of solitary stars, especially those with planetary systems.
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How bacteria could make you smarter

How bacteria could make you smarter | Fragments of Science | Scoop.it
There could be a simple way of enhancing your cognitive abilities: different gut bacteria.
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Two Scientists Are Turning Hurricanes Into Music

Two Scientists Are Turning Hurricanes Into Music | Fragments of Science | Scoop.it
This will change the way you think about hurricanes forever.
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How the immune system's key organ regenerates itself

How the immune system's key organ regenerates itself | Fragments of Science | Scoop.it
With advances in cancer immunotherapy splashing across headlines, the immune system's powerful cancer assassins—T cells—have become dinner-table conversation. But hiding in plain sight behind that "T" is the organ from which they get their name and learn their craft: the thymus.

A new study published Friday in Science Immunology identifies a molecule called BMP4 that plays a key role in the thymus's extraordinary natural ability to recover from damage.

In this video, Dr. Jarrod Dudakov of Fred Hutchinson Cancer Research Center, one of the study's leaders, talks about the importance of the thymus, the discoveries he and his colleagues have made about how it regenerates, and the team's next steps. The researchers hope to translate their work into new therapies to improve the function of the immune system in old age and make immunotherapies more effective.
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Seeing in the dark—how plant roots perceive water through growth

Seeing in the dark—how plant roots perceive water through growth | Fragments of Science | Scoop.it
Without eyes, ears, or a central nervous system, plants can perceive the direction of environmental cues and respond to ensure their survival.
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Iron-rich stars host shorter-period planets

Iron-rich stars host shorter-period planets | Fragments of Science | Scoop.it
Astronomers with the Sloan Digital Sky Survey (SDSS) have learned that the chemical composition of a star can exert unexpected influence on its planetary system—a discovery made possible by an ongoing SDSS survey of stars seen by NASA's Kepler spacecraft, and one that promises to expand our understanding of how extrasolar planets form and evolve.

"Without these detailed and accurate measurements of the iron content of stars, we could have never made this measurement," says Robert Wilson, a graduate student in astronomy at the University of Virginia and lead author of the paper announcing the results.

The team presented their results today at the American Astronomical Society (AAS) meeting in National Harbor, Maryland. Using SDSS data, they found that stars with higher concentrations of iron tend to host planets that orbit quite close to their host star—often with orbital periods of less than about eight days—while stars with less iron tend to host planets with longer periods that are more distant from their host star. Further investigation of this effect may help us understand the full variety of extrasolar planetary systems in our Galaxy, and shed light on why planets are found where they are.
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Can large objects exist in a quantum state?

Can large objects exist in a quantum state? | Fragments of Science | Scoop.it
Even after an acclimatisation period of more than 100 years, quantum mechanical phenomena still conflicts with our intuition of how nature works. Quantum mechanics confuses and marvels us in equal measure.
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Team maps magnetic fields of bacterial cells and nano-objects for the first time

Team maps magnetic fields of bacterial cells and nano-objects for the first time | Fragments of Science | Scoop.it
A research team led by a scientist from the U.S. Department of Energy's Ames Laboratory has demonstrated for the first time that the magnetic fields of bacterial cells and magnetic nano-objects in liquid can be studied at high resolution using electron microscopy. This proof-of-principle capability allows first-hand observation of liquid environment phenomena, and has the potential to vastly increase knowledge in a number of scientific fields, including many areas of physics, nanotechnology, biofuels conversion, biomedical engineering, catalysis, batteries and pharmacology.

"It is much like being able to travel to a Jurassic Park and witness dinosaurs walking around, instead of trying to guess how they walked by examining a fossilized skeleton," said Tanya Prozorov, an associate scientist in Ames Laboratory's Division of Materials Sciences and Engineering.
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Cheap, sustainable battery made from tree bark tannins

Cheap, sustainable battery made from tree bark tannins | Fragments of Science | Scoop.it
Tannins may be best known for their presence in red wine and tea, but in a new study researchers have demonstrated for the first time that tannins from tree bark can also serve as battery cathode materials. As tree bark is approximately 15% tannins by weight, tannins are naturally abundant, which is one factor that makes them a promising material for designing sustainable, low-cost, metal-free, high-performance batteries.

Besides their widespread availability, another reason why tannins appear to be such a promising battery material is their high levels of phenol—they have the highest phenol content among any polymer produced by living organisms. High levels of phenol are important because the primary charge storage mechanism of the tannin-based battery is a reversible chemical reaction in which phenol is converted into quinone.

The researchers, led by Hongli Zhu at Northeastern University in Boston, along with PhD student Alolika Mukhopadhyay as the lead author and coauthors from the National Renewable Energy Laboratory in Golden, Colorado, have published a paper on the tannin battery cathode in a recent issue of Nano Letters.
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Oldest fossils ever found show life on Earth began before 3.5 billion years ago

Oldest fossils ever found show life on Earth began before 3.5 billion years ago | Fragments of Science | Scoop.it
Researchers at UCLA and the University of Wisconsin-Madison have confirmed that microscopic fossils discovered in a nearly 3.5 billion-year-old piece of rock in Western Australia are the oldest fossils ever found and indeed the earliest direct evidence of life on Earth.

The study, published today in the Proceedings of the National Academy of Sciences, was led by J. William Schopf, professor of paleobiology at UCLA, and John W. Valley, professor of geoscience at the University of Wisconsin-Madison. The research relied on new technology and scientific expertise developed by researchers in the UW-Madison WiscSIMS Laboratory.

The study describes 11 microbial specimens from five separate taxa, linking their morphologies to chemical signatures that are characteristic of life. Some represent now-extinct bacteria and microbes from a domain of life called Archaea, while others are similar to microbial species still found today. The findings also suggest how each may have survived on an oxygen-free planet.

The microfossils—so called because they are not evident to the naked eye—were first described in the journal Science in 1993 by Schopf and his team, which identified them based largely on the fossils' unique, cylindrical and filamentous shapes. Schopf, director of UCLA's Center for the Study of Evolution and the Origin of Life, published further supporting evidence of their biological identities in 2002.
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Genetic instructions from mom set the pattern for embryonic development

Genetic instructions from mom set the pattern for embryonic development | Fragments of Science | Scoop.it
A new study indicates an essential role for a maternally inherited gene in embryonic development. The study found that zebrafish that failed to inherit specific genetic instructions from mom developed fatal defects earlier in development, even if the fish could make their own version of the gene. The study by researchers at Princeton University was published Nov. 15 in the journal eLife.

When female animals form egg cells inside their ovaries, they deposit messenger RNAs (mRNAs) - a sort of genetic instruction set - in the egg cell cytoplasm. After fertilization, these maternally supplied mRNAs can be translated into proteins required for the early stages of embryonic development, before the embryo is able to produce mRNAs and proteins of its own.

More than thirty years ago, researchers discovered that mRNAs encoding a protein called Vg1 are deposited in the cytoplasm of frog eggs. "vg1 is famous for being one of the first recognized maternal mRNAs," said Rebecca Burdine, associate professor of molecular biology at Princeton. "A wealth of papers have been written on how this RNA is localized and regulated, but it was never clear what the Vg1 protein actually does in the developing embryo."
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Real-time observation of collective quantum modes

Real-time observation of collective quantum modes | Fragments of Science | Scoop.it
A cylindrical rod is rotationally symmetric - after any arbitrary rotation around its axis it always looks the same. If an increasingly large force is applied to it in the longitudinal direction, however, it will eventually buckle and lose its rotational symmetry. Such processes, known as "spontaneous symmetry breaking", also occur in subtle ways in the microscopic quantum world, where they are responsible for a number of fundamental phenomena such as magnetism and superconductivity. A team of researchers led by ETH professor Tilman Esslinger and Senior Scientist Tobias Donner at the Institute for Quantum Electronics has now studied the consequences of spontaneous symmetry breaking in detail using a quantum simulator. The results of their research have recently been published in the scientific journal Science.
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These 9 Airplanes Transformed Flight Over the Last Century

These 9 Airplanes Transformed Flight Over the Last Century | Fragments of Science | Scoop.it
On the anniversary of the Wright brothers’ flight, see how flying has evolved since—and the otherworldly models that may be in our future.
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Machine finds alien solar system contains as many planets as our own

Machine finds alien solar system contains as many planets as our own | Fragments of Science | Scoop.it
A record-tying eighth planet is found by NASA and Google in a faraway solar system, and like Earth, the new planet is the third rock from its sun but can orbit it in just 14 days.
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Robot swarms to map the seafloor

Robot swarms to map the seafloor | Fragments of Science | Scoop.it
A UK-based team's low-cost autonomous technology aims to transform our knowledge of the oceans.
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