Share:Freshwater fish, amphibians supercharge their ability to see infrared light

Date:November 5, 2015

Source:Washington University in St. Louis

Summary:Salmon migrating from the open ocean to inland waters do more than swim upstream. To navigate the murkier freshwater streams and reach a spot to spawn, the fish have evolved a means to enhance their ability to see infrared light.

Salmon and other freshwater fish and amphibians supercharge their ability to see red and infrared light. Scientists at Washington University School of Medicine in St. Louis have shown that this evolutionary adaptation hinges on the activity of an enzyme that converts vitamin A1 to vitamin A2, enabling the aquatic creatures to more easily navigate murky waters.
Credit: National Park Service

Salmon migrating from the open ocean to inland waters do more than swim upstream. To navigate the murkier freshwater streams and reach a spot to spawn, the fish have evolved a means to enhance their ability to see infrared light. Humans lack this evolutionary adaptation.

For nearly a century, scientists have puzzled over how salmon as well as other freshwater fish and amphibians, including frogs, easily shift their vision from marine or terrestrial environments — where the light environment is blue-green — to the waters of inland steams. In such streams, mud, algae and other particles filter out light from the blue end of the visual spectrum, creating a light environment that shifts to the red and infrared end of the spectrum.

Now, scientists at Washington University School of Medicine in St. Louis report in the journal Current Biology that they have solved the mystery.

“We’ve discovered an enzyme that switches the visual systems of some fish and amphibians and supercharges their ability to see infrared light,” said senior author Joseph Corbo, MD, PhD, associate professor of pathology and immunology. “For example, when salmon migrate from the ocean to inland streams, they turn on this enzyme, activating a chemical reaction that shifts the visual system, helping the fish peer more deeply into murky water.”

As it turns out, the enzyme — called Cyp27c1 — is closely linked to vitamin A, long known to promote good vision, especially in low light. The enzyme converts vitamin A1 to vitamin A2; the latter has remarkable properties to enhance the ability to see longer wavelength light such as red and infrared light.

The findings could lead to advances in biomedical research, particularly in optogenetics, a hot, new field in which light is used to control the firing of neurons in the brain. Optogenetic applications currently are limited to visible light, which penetrates only the top layer of neural tissue.

But if scientists are able to incorporate the newly discovered enzyme, they may be able to activate photosensitive neurons with infrared light, which penetrates much deeper. “Just as the enzyme helps fish peer into murky water, it could help us peer deeper into the brain,” said Corbo.

Corbo and his team made the enzyme discovery in zebrafish — tiny, transparent freshwater fish that remain a staple of laboratory research. They confirmed their findings in bullfrogs, whose eyes are uniquely designed for the light environments of both air and freshwater.

Bullfrogs sit with their eyes at the water’s surface so that they can look up into the air and down into the water at the same time. The researchers found vitamin A2 and the enzyme Cyp27c1 right where they expected: in the upper half of the bullfrog’s eyes that peer down into the water, but not in the lower half which looks upward into the air.

Furthermore, the scientists showed that zebrafish with normal copies of the cyp27c1 gene move toward infrared light shined into a dark aquarium. But fish with disabled cyp27c1 genes continue to behave like they are in the dark, whether or not the infrared light is on.

Humans have a form of the same gene, but it is not turned on in the eye. Thus, people are not able enhance their infrared vision in the same way fish can. To do so, they must wear night-vision goggles. “We don’t know yet how this enzyme is utilized in the human body,” Corbo said.

“But just because our eyes don’t make vitamin A2 doesn’t mean we can’t use it,” he said. Research on medical students in the 1940s showed that people who consume vitamin A2 have an enhanced ability to detect red and infrared light. In 2013, a group of “biohackers” successfully crowdfunded an experiment to try to extend their vision into the near-infrared spectrum by eating a diet supplemented with vitamin A2.

“I wouldn’t necessarily recommend following their dietary advice, but the concept is sound,” Corbo said.

Story Source:

The above post is reprinted from materials provided by Washington University in St. Louis. The original item was written by Tamara Bhandari.Note: Materials may be edited for content and length.

Journal Reference:

  1. Jennifer M. Enright, Matthew B. Toomey, Shin-ya Sato, Shelby E. Temple, James R. Allen, Rina Fujiwara, Valerie M. Kramlinger, Leslie D. Nagy, Kevin M. Johnson, Yi Xiao, Martin J. How, Stephen L. Johnson, Nicholas W. Roberts, Vladimir J. Kefalov, F. Peter Guengerich, Joseph C. Corbo. Cyp27c1 Red-Shifts the Spectral Sensitivity of Photoreceptors by Converting Vitamin A1 into A2. Current Biology, 2015; DOI: 10.1016/j.cub.2015.10.018

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American Journal of Modern Physics

122 (1)ISSN Print: 2326-8867
ISSN Online: 2326-8891
American Journal of Modern Physics (AJMP) aims to promote rapid communication and dialogue among the researchers, scientists, engineers and policy makers working in the areas of modern physics in the world. It brings the broad fundamental physics literature in established topical areas together and places it within the context of current trends in research and applications. AJMP welcomes the following tier 1 article types: Book Review, Editorial, General Commentary, Hypothesis & Theory, Methods, Mini Review, Opinion, Original Research, Perspective, Review, Specialty Grand Challenge and Technology Report.
American Journal of Modern Physics is a peer-reviewed, international, open access journal that publishes original research articles as well as review articles dealing with all aspects of research on physics. Subject areas may include, but are not limited to the following fields:
General physics                                                         Applied biophysics
Dielectrics and ferroelectricity                              Device physics
Gravitation and astrophysics                                 Elementary particles and fields
Nuclear and hadronic physics                               Optical physics
Fluid and plasma physics                                       Statistical and nonlinear physics
Condensed matter physics                                     Biological physics
Quantum information                                            High-energy physics
Nanotechnology                                                      Characterization materials
Evaluation materials                                              Surfaces and interfaces thin films
Operating procedures                                            Materials treatment
Electronic structure and transport                     Interdisciplinary physics
Astrophysics                                                            Magnetism and superconductivity
Plasmas and electrical discharges                      Atomic physics
Chemical physics                                                    Molecular physics

Share Video: Giant guitarfish eye gymnastics

Like sharks, the giant guitarfish doesn’t have eyelids that close all the way, so it can’t blink. That might guarantee a win in a staring contest, but it does pose problems for eye protection in the sandy, tropical waters where the creature lives. So when thrashing prey kick sand or bits of coral its way, the guitarfish protects itself with an eye-catching method: retracting its eyes almost completely into its head, leaving a craterlike depression. Now, new research shows that guitarfish can thank a specialized eye muscle for that ability. Using high-speed video, researchers found a guitarfish could sink its eye nearly 40 mm. That’s almost as much as the diameter of the eyeball itself and likely more than any other vertebrate, the researchers reported online before print in Zoology. A muscle known as the obliquus inferior appears to be key; when the researchers electrically stimulated the muscle in a dissected guitarfish, the eyeball sank. Other animals, including frogs, bottlenose dolphins, and mudskippers, also retract their eyes, but employ a different mechanism. Some rays and skates, however, have the same muscle arrangement as guitarfish, so researchers are eyeing them for future studies.

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Treason and War: English Gentry Families: Sir Thomas Kiriel 1400-1480, a book worth reading

big53Author: Tarık Tolga Gümüş
ISBN: 978-1-940366-54-8
Published Date: September, 2015
Pages: 106
About the Authors
Tarık Tolga Gümüş has completed his Masters Degree in Bilkent University in Ankara in the Department of History, after graduating from the Middle East Technical University from the Department of Philosophy. His master’s thesis was related to the European History. Then, he completed his PhD. in the same university in 2007. His PhD. dissertation was about the fifteenth century British history. The author is currently working at Mersin University, Department of History. His areas of interest are fifteenth century English history, aristocracy, gentry class and chivalry. He also teaches the Medieval European History Medieval French, and the history of Early Modern Europe.
About the book
The importance of the gentry class families in the political history of the fifteenth century is becoming more and more apparent in the academic developments of the recent years. Therefore, this book is focused on the life and career of one individual of these gentry families. The life and career of Thomas Kiriel who was the knight of the body and who was actively enrolled in the wars with France in the king’s side are analyzed. The study shows that Thomas Kiriel took his fortune from the land and military service to the king Henry VI. Then when he changed side he was accused of treason and beheaded.
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Science News-Latest experiment at Large Hadron Collider reports first results

Source:Massachusetts Institute of Technology

Summary:After a two-year hiatus, the Large Hadron Collider, the largest and most powerful particle accelerator in the world, began its second run of experiments in June, smashing together subatomic particles at 13 teraelectronvolts (TeV) — the highest energy ever achieved in a laboratory. Physicists hope that such high-energy collisions may produce completely new particles, and potentially simulate the conditions that were seen in the early universe.

Particles created from the proton collision stream out from the center of the Compact Muon Solenoid detector. They are first detected by the Silicon Tracker, whose data can be used to reconstruct the particle trajectories, indicated by yellow lines. An Electromagnetic Calorimeter detects energy deposited by electrons and photons, indicated by green boxes. The energy detected by the Hadronic Calorimeter, the primary component of jets, is indicated by blue boxes. Particles reaching the outermost parts of the detector are indicated in red.
Credit: CERN

After a two-year hiatus, the Large Hadron Collider, the largest and most powerful particle accelerator in the world, began its second run of experiments in June, smashing together subatomic particles at 13 teraelectronvolts (TeV) — the highest energy ever achieved in a laboratory. Physicists hope that such high-energy collisions may produce completely new particles, and potentially simulate the conditions that were seen in the early universe.

In a paper to appear in the journal Physics Letters B, the Compact Muon Solenoid (CMS) collaboration at the European Organization for Nuclear Research (CERN) reports on the run’s very first particle collisions, and describes what an average collision between two protons looks like at 13 TeV. One of the study leaders is MIT assistant professor of physics Yen-Jie Lee, who leads MIT’s Relativistic Heavy Ion Group, together with physics professors Gunther Roland and Bolek Wyslouch.

In the experimental run, researchers sent two proton beams hurtling in opposite directions around the collider at close to the speed of light. Each beam contained 476 bunches of 100 billion protons, with collisions between protons occurring every 50 nanoseconds. The team analyzed 20 million “snapshots” of the interacting proton beams, and identified 150,000 events containing proton-proton collisions.

For each collision that the researchers identified, they determined the number and angle of particles scattered from the colliding protons. The average proton collision produced about 22 charged particles known as hadrons, which were mainly scattered along the transverse plane, immediately around the main collision point.

Compared with the collider’s first run, at an energy intensity of 7 TeV, the recent experiment at 13 TeV produced 30 percent more particles per collision.

Lee says the results support the theory that higher-energy collisions may increase the chance of finding new particles. The results also provide a precise picture of a typical proton collision — a picture that may help scientists sift through average events looking for atypical particles.

“At this high intensity, we will observe hundreds of millions of collisions each second,” Lee says. “But the problem is, almost all of these collisions are typical background events. You really need to understand the background well, so you can separate it from the signals for new physics effects. Now we’ve prepared ourselves for the potential discovery of new particles.”

Shrinking the uncertainty of tiny collisions

Normally, 13 TeV is not a large amount of energy — about that expended by a flying mosquito. But when that energy is packed into a single proton, less than a trillionth the size of a mosquito, that particle’s energy density becomes enormous. When two such energy-packed protons smash into each other, they can knock off constituents from each proton — either quarks or gluons — that may, in turn, interact to produce entirely new particles.

Predicting the number of particles produced by a proton collision could help scientists determine the probability of detecting a new particle. However, existing models generate predictions with an uncertainty of 30 to 40 percent. That means that for high-energy collisions that produce a large number of particles, the uncertainty of detecting rare particles can be a considerable problem.

“For high-luminosity runs, you might have up to 100 collisions, and the uncertainty of the background level, based on existing models, would be very big,” Lee says.

To shrink this uncertainty and more precisely count the number of particles produced in an average proton collision, Lee and his team used the Large Hadron Collider’s CMS detector. The detector is built around a massive magnet that can generate a field that’s 100,000 times stronger than Earth’s magnetic field.

Typically, a magnetic field acts to bend charged particles that are produced by proton collisions. This bending allows scientists to measure a particle’s momentum. However, an average collision typically produces lightweight particles with very low momentum — particles that, in a magnetic field, end up coiling their way toward the main collider’s beam pipe, instead of bending toward the CMS detector.

To count these charged, lightweight particles, the scientists analyzed the data with the detector’s magnet off. While they couldn’t measure the particles’ momentum, they could precisely count the number of charged particles, and measure the angles at which they arrived at the detector. The measurements, Lee says, give a more accurate picture of an average proton collision, compared with existing theoretical models.

“Our measurement actually shrinks the uncertainty dramatically, to just a few percent,” Lee says.

Simulating the early universe

Knowing what a typical proton collision looks like will help scientists set the collider to essentially see through the background of average events, to more efficiently detect rare particles.

Lee says the new results may also have a significant impact on the study of the hot and dense medium from the early universe. In addition to proton collisions, scientists also plan to study the highest-energy collisions of lead ions, each of which contain 208 protons and neutrons. When accelerated in a collider, lead ions flatten into disks due to a force called the Lorentz contraction. When smashed together, lead ions can generate hundreds of interactions between protons and produce an extremely dense medium that is thought to mimic the conditions of space just after the Big Bang. In this way, the Large Hadron Collider experiment could potentially simulate the condition of the very first moments of the early universe.

“One microsecond after the Big Bang, the universe was very dense and hot — about 1 trillion degrees,” Lee says. “With lead ion collisions, we can reproduce the early universe in a ‘small bang.’ If we can understand what one proton collision looks like, we may be able to get some more insights about what will happen when hundreds of them occur at the same time. Then we can see what we can learn about the early universe.”

This research was funded, in part, by the U.S. Department of Energy.

Story Source:

The above post is reprinted from materials provided by Massachusetts Institute of Technology. The original item was written by Jennifer Chu.Note: Materials may be edited for content and length.

Journal Reference:

  1. CMS Collaboration. Pseudorapidity distribution of charged hadrons in proton–proton collisions at √s=13 TeV. Physics Letters B, 2015; DOI: 10.1016/j.physletb.2015.10.004

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Scientific paper:Gravitational Propulsion by Help of Vacuum Holes

Authors: Constantin Leshan

Abstract: A new concept, the gravitational propulsion, or “Hole Levitation”, is proposed which propels vehicle by using the artificial gravity (vacuum holes). Such gravitational propulsion is similar to gravitational slingshot but without the need for large masses like planets and complicate maneuvers. The source of artificial gravitation accelerates the vehicle in one direction and the surrounding medium in the opposite direction. Therefore, it is not a reactionless drive: momentum is taken from the surrounding stars and planets and conferred on the vehicle and thus is conserved overall. The artificial gravity generator can damp or neutralize inertial forces due to the levitating vehicle is able to move with large acceleration, which is not acceptable for other means of transport.

image002 (42)

Keywords: Artificial Gravity, Vacuum Holes, Gravity Control, Levitation, Inertia

If you like, you can read this scientific paper in American Journal of Modern Physics.

News:Wolves beat dogs at problem-solving test

Facing a treat-filled puzzle, wolves proved less willing than dogs to give

7:00AM, OCTOBER 12, 2015
dogs looking

Humans may be a bad influence on their best friends — at least when it comes to problem-solving. In a task that wasn’t very tough, wolves outperformed dogs. All any of the animals had to do was tug the lid off of a food container.

Monique Udell studies animal behavior at Oregon State University in Corvallis. In recent tests, canine were given a closed, plastic storage box containing a sausage treat. Eight of the 10 wolves successfully gnawed, pawed and ripped their way into the container — then gobbled up the treat. In contrast, just one in 20 dogs succeeded at the same challenge.

The social tendencies of dogs may be getting in the way of persistent, independent struggling that would have freed the treat, Udell now suggests.

She tested 10 pet dogs and another 10 dogs from an animal shelter (that had each had some history of pethood). In one set of tests, a person was nearby but did not encourage or discourage the dogs. Those dogs typically spent 10 to 15 percent of their time gazing at the person. They spent a mere 5 percent of their time or less touching the container.

Udell offered the same challenge to wolves. These animals had been raised and fed by people but still lived outdoors. Here, the wolves barely looked at a nearby person. Instead, they devoted about 90 percent of each two-minute trial to grappling with the box holding a treat.

When someone hovered over the dogs and actively encouraged them to keep trying to open the box, the dogs did spend more time tackling the problem. A few more even managed to open the box. But their success rate still did not match the wolves.  The dogs and wolves also were tested when no one was present. But even now, the dogs didn’t paw or mouth the box much more than they did when a human was present.

Udell published her findings September 16 in Biology Letters.


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Advances in Surgical Sciences

256Advances in Surgical Sciences (ASS)

ISSN Print: 2376-6174
ISSN Online: 2376-6182
Advances in Surgical Sciences (ASS) provides a forum for the publication of scientific research and review articles. The journal publishes original full-length research papers in all areas related to surgical diseases or exploring pathogenesis, etiology, and mechanisms of disease processes are given priority. Research articles which integrate molecular biological methods, along with functional studies, into the analysis of biological questions and advance basic as well as translational knowledge in surgical pathophysiology are also welcomed.
Advances in Surgical Sciences is a peer-reviewed, open access, online journal, publishing original research, reports, reviews and commentaries on all areas of surgical sciences. Subject areas may include, but are not limited to the following fields:
Trauma surgery          Laparoscopic surgery
Colorectal surgery      Breast surgery
Vascular surgery         Endocrine surgery
Transplant surgery     Surgical oncology
Clinical and experimental surgery
Surgical education and history
Surgical care               Cardiothoracic surgery
Surgical practice and teaching
Lower GI surgery        Surgical management
Upper GI surgery
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Share Video: Caterpillars head-butt intruders during turf battles

Fat, fuzzy caterpillars might not seem like the aggressive type. But new research reveals that some of the insects aren’t above using their heads to push and pummel other caterpillars out of their home territory. The study, published in the Journal of Insect Behavior, looked at four types of “leaf-tying” caterpillars, which fashion shelters from silk and feces between pairs of overlapping leaves. After allowing unsuspecting caterpillars to set up house in an artificial leaf tie, the researcher staged confrontations between the resident insects and would-be intruders. When a challenger approached, the headstrong rivals battled it out by pushing or even walloping one another with their heads, as seen in this video, until one retreated. In more than half of all interactions, the defender won. In 24% of the confrontations, the usurper emerged victorious, whereas in another 24%, the former fighters established an uneasy peace, sharing the same space they had been battling over. Defenders may be more successful at fending off aspiring shelter crashers because they have more to lose, having expended the energy to build the protective structures in the first place, the paper says. Although such humble poop and silk digs may not look like much to us, for these caterpillars, home is where the crap is—and they’ll spare no head-butt to defend it.

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