“We’re introducing blue light into the environment and into our daily lives at times when we’re not supposed to see it – and that basically causes dysfunction in our biological processes.” — Brian Zoltowski
KERA Public Radio journalist Justin Martin explored the good and bad of blue light in our environment with Brian Zoltowski, an assistant professor in the SMU Department of Chemistry.
“As a society, we are using more technology, and there’s increasing evidence that artificial light has had a negative consequence on our health,” says Zoltowski, who was awarded $320,500 from the National Institute of General Medical Sciences of the National Institutes of Health to continue its research on the impact of blue light.
“Our study uses physical techniques and chemical approaches to probe an inherently biological problem,” Zoltowski said. “We want to understand the chemical basis for how organisms use light as an environmental cue to regulate growth and development.”
By Justin Martin
KERA
Light is necessary for life on earth, but scientists believe that too much of a certain wavelength can cause everything from crop diseases to changes in the migratory patterns of animals. SMU professor Brian Zoltowski is working to unravel the mystery of blue light in a study funded by the National Institutes of Health.
Interview Highlights: Brian Zoltowski
… On what defines blue light:
“Blue light refers to a part of the electromagnetic spectrum that has specific energy. Usually we define things by basically their wavelength of light. So typically blue light can be centered around 450 nanometers but can range … from about 425 nanometers to 475 nanometers.”
… On the origin of excess blue light:
“Blue light is very abundant in nature in general. That’s why organisms actually use that wavelength of light to drive their biological processes. But it turns out though that because it’s abundant in nature, we like to have it to be abundant in our products like our lights, our computers, our laptops and everything else. So we introduce a lot more foreign blue light into the environment compared to what should naturally be there.”
… On blue light’s effects in animals vs. plants:
“A lot of that is not known, which is one of the reasons we’re actually doing a lot of this research. What we do know is that blue is extremely important for basically growth and development of any organism you can conceive of. How that’s ultimately regulated and when there can be too much is a big question. The bigger question is when you get the blue light, nature is designed to use blue light as a signal as to what time of day it is. So when we’re introducing blue light into the environment or into our daily lives through computers and laptops, we’re introducing blue light at times of day like evening when we’re not supposed to see it – and that basically causes dysfunction in our biological processes.”
… On how blue light fosters fungal growth:
“There’s growing understanding that a lot of these fungal pathogens of plants – there are several that actually attack wine, which causes billions of dollars of crop loss each year. There are some that we’re interested in that also basically attack a lot of your grain crops — so you’re looking at wheat, alfalfa — that have very detrimental aspects to agriculture. Their ability to infect the plant is regulated by blue light.”
Blue light from artificial lighting and electronic devices knocks circadian rhythms off-kilter, resulting in health problems, sleep, cancer development, mood disorders, drug addiction, crop disease and even confused migratory animals
A study funded by the National Institutes of Health is unraveling the mystery of how blue light from residential and commercial lighting, electronic devices and outdoor lights can throw off-kilter the natural body clock of humans, plants and animals, leading to disease.
At the right time of day, blue light is a good thing. It talks to our 24-hour circadian clock, telling our bodies, for example, when to wake up, eat and carry out specific metabolic functions.
In plants, blue light signals them to leaf out, grow, blossom and bloom. In animals, it aids migratory patterns, sleep and wake cycles, regulation of metabolism, as well as mood and the immune system.
But too much blue light — especially at the wrong time — throws biological signaling out of whack.
“As a society, we are using more technology, and there’s increasing evidence that artificial light has had a negative consequence on our health,” said Zoltowski, an assistant professor in SMU’s Department of Chemistry.
“Our study uses physical techniques and chemical approaches to probe an inherently biological problem,” he said. “We want to understand the chemical basis for how organisms use light as an environmental cue to regulate growth and development.”
The lab studies a small flowering plant native to Europe and Asia, Arabidopsis thaliana. The flower is a popular model organism in plant biology and genetics, Zoltowski said.
Although signaling pathways differ in organisms such as Arabidopsis when compared to animals, the flower still serves an important research purpose. How the signaling networks are interconnected is similar in both animals and Arabidopsis. That allows researchers to use simpler genetic models to provide insight into how similar networks are controlled in more complicated species like humans.
Understanding the mechanism can lead to targeted drug treatments
In humans, the protein melanopsin absorbs blue light and sends signals to photoreceptor cells in our eyes. In plants and animals, the protein cryptochrome performs similar signaling.
Much is known already about the way blue light and other light wavelengths, such as red and UV light, trigger biological functions through proteins that interact with our circadian clock. But the exact mechanism in that chemical signaling process remains a mystery.
“Light is energy, and that energy can be absorbed by melanopsin proteins that act as a switch that basically activates everything downstream,” Zoltowski said.
Melanopsin is a little-understood photoreceptor protein with the singular job of measuring time of day.
When light enters the eye, melanopsin proteins within unique cells in the retina absorb the wavelength as a photon and convert it to energy. That activates cells found only in the eye — called intrinsically photosensitive retinal ganglian cells, of which there are only about 160 in our body. The cells signal the suprachiasmatic nucleus region of the brain.
“We keep a master clock in the suprachiasmatic nucleus — it controls our circadian rhythms,” he said. “But we also have other time pieces in our body; think of them as watches, and they keep getting reset by the blue light that strikes the master clock, generating chemical signals.”
The switch activates many biological functions, including metabolism, sleep, cancer development, drug addiction and mood disorders, to name a few.
“There’s a very small molecule that absorbs the light, acting like a spring, pushing out the protein and changing its shape, sending the signal. We want to understand the energy absorption by the small molecule and what that does biologically.”
The answer can lead to new ways to target diabetes, sleep disorders and cancer development, for example.
“If we understand how all these pathways work,” he said, “we can design newer, better, more efficacious drugs to help people.”
Chemical signal from retina’s “atomic clock” synchronizes circadian rhythms
Besides increased reliance on artificial lighting indoors and outdoors, electronic devices also now contribute in a big way to blue light exposure. Endless evening hours on our smartphones and tablets with Candy Crush, Minecraft or Instagram don’t really help us relax and go to sleep. Just the opposite, in fact.
The blue glow those devices emit signals our circadian clock that it’s daytime, Zoltowski said. Red light, on the other hand, tells us to go to sleep.
Awareness of the problem has prompted lighting manufacturers to develop new lighting strategies and products that transition blue light to red light toward evening and at night, Zoltowski said.
Targeted solutions could neutralize destructive blight in staple crops
In plants, the researchers study how the absence of “true dark” in nature due to artificial light can reduce yields of farm crops and promote crop disease.
For example, fungal systems rely on blue light to proliferate, forming pathogens known as blight in crops resulting in leaves that look chewed on and reducing yields.
“We study fusarium and verticillium,” Zoltowski said. “They cause about $3 billion worth of crop damage a year to wheat, corn, soybeans — the staple food crops.”
Understanding their ability to infect crops would allow scientists to potentially design small molecules that target and disrupt the fungal system’s circadian clock and neutralize their proliferation.
Research to understand how light and clock regulation are coupled
In animals, Zoltowski’s lab studies the blue light pathway that signals direction to birds and other animals that migrate. Blue light activates the protein that allows various species to measure the earth’s magnetic field for directionality. For example, Monarch butterflies rely on the cryptochrome photoreceptor for their annual migration to Mexico.
“We’re interested in how these pathways are regulated in a diverse range of organisms to understand how we can manipulate these pathways to our advantage,” he said, “for health consequences and to improve agriculture yields.”
The researchers will map the reaction trajectory beginning from the initial absorption of the photon to the point it alters an organism’s physiology.
Zoltowski notes that light is just one of a handful of external cues from our environment that trigger biological processes regulating the circadian clock. Others include temperature changes, feeding and metabolites.
Besides the NIH grant, the lab operates with $250,000 from the American Chemical Society’s Herman Frasch Foundation for Chemical Research Grants in Agricultural Chemistry. — Margaret Allen
First detailed chemical analysis of ancient soil from the Morrison Formation — a massive source of significant dinosaur discoveries for more than 100 years— reveals there was an unexpected abrupt change from arid to wet environments during the Jurassic.
The climate 150 million years ago of a large swath of the western United States was more complex than previously known, according to new research from Southern Methodist University, Dallas.
It’s been held that the climate during the Jurassic was fairly dry in New Mexico, then gradually transitioned to a wetter climate northward to Montana.
But based on new evidence, the theory of a gradual transition from a dry climate to a wetter one during the Jurassic doesn’t tell the whole story, says SMU paleontologist Timothy S. Myers, lead author on the study.
Geochemical analysis of ancient soils, called paleosols, revealed an unexpected and mysterious abrupt transition from dry to wet even though some of the samples came from two nearby locales, Myers said.
Myers discovered the abrupt transition through geochemical analysis of more than 40 ancient soil samples.
Paleosol matrix was collected in the field by SMU paleontologist Timothy S. Myers for chemical analysis of the ancient soil by grinding it to a powder, which was then fused into a glass disc for elemental analysis. (Myers, SMU)
He collected the samples from the Morrison Formation, a vast rock unit that has been a major source of significant dinosaur discoveries for more than 100 years.
The Morrison extends from New Mexico to Montana, sprawling across 13 states and Canada, formed from sediments deposited during the Jurassic.
Myers’ study is the first in the Morrison to significantly draw on quantitative data — the geochemistry of the rocks.
The abrupt transition, Myers says, isn’t readily explained.
“I don’t have a good explanation,” he said. “Normally when you see these dramatic differences in climate in areas that are close to one another it’s the result of a stark variation in topography. But in this case, there weren’t any big topographic features like a mountain range that divided these two localities in the Jurassic.”
Surprisingly, paleosols from the sample areas did not reveal marked differences until they were analyzed using geochemical weathering indices.
Paleosol samples from the Jurassic in Wyoming indicate this area of the massive Morrison Formation surprisingly was more arid than its counterpart in New Mexico. (Credit: Myers, SMU)
“It’s sobering to think that by just looking at the paleosols superficially at these localities, they don’t appear incredibly different. We see the same types of ancient soils in both places,” Myers said. “So these are some fairly major climate differences that aren’t reflected in the basic ancient soil types. Yet this is what a lot of scientists, myself included, depend on for a first pass idea of paleoclimate in an area — certain types of soils form in drier environments, others in wetter, others in cooler, that sort of thing.”
That didn’t hold true for the current study.
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To book a live or taped interview with Dr. Scott Myers in the SMU News Broadcast Studio call SMU News at 214-768-7650 or email SMU News at news@smu.edu.
With the geochemical analysis, Myers estimated the mean average precipitation during the Jurassic for northern Montana was approximately 45 inches, 20 inches for northern Wyoming and 30 inches for New Mexico.
“This changes how we view the distribution of the types of environments in the Morrison,” Myers said. “Too many times we talk about the Morrison as though it was this monolithic unit sprinkled with patchy, but similar, variations. But it’s incredibly large. It spans almost 10 degrees of latitude. So it’s going to encompass a lot of different environments. Regions with broadly similar climates can have internal differences, even over short distances. That’s the take-home.”
Co-authors of the study were Neil J. Tabor, SMU earth sciences professor and an expert in ancient soil, and Nicholas Rosenau, a stable isotope geochemist, Dolan Integration Group.
The popular artistic representations we see today of dinosaurs in a landscape setting are based on bits of evidence from plant and animal fossils found in various places, Tabor said. While that’s based on the best information to date, it’s probably inaccurate, he said. Myers’ findings provide new insights to many studies that have been done prior to his. This will drive paleontologists and geologists to seek out more quantitative data about the ancient environment.
“The geology of the Morrison has been studied exhaustively from an observational standpoint for 100 years,” Tabor said. “I have no doubt there will be many more fossil discoveries in the Morrison, even though over the past century we’ve gained a pretty clear understanding of the plants and animals at that time. But now we can ask deeper questions about the landscape and how organisms in the ancient world interacted with their environment.”
Surprising results: Northern locale more arid than southern locale
The Morrison Formation has produced some of our most familiar dinosaurs, as well as new species never seen before. Discoveries began in the late 1800s and ultimately precipitated the Bone Wars — the fossil equivalent of California’s Gold Rush.
After Myers studied dinosaur fossils from the Morrison, he became curious about the climate. Embarking on the geochemical analysis, Myers, like scientists before him, hypothesized the climate would be similar to modern zonal circulation patterns, which are driven by the distribution of the continents. Under that hypothesis, New Mexico would be relatively arid, and Wyoming and Montana both would be wetter at the time dinosaurs roamed the landscape.
Myers analyzed 22 paleosol samples from northern New Mexico, 15 from northern Wyoming and seven from southern Montana. The samples from Montana were younger than those from New Mexico, but roughly contemporary with the samples from Wyoming.
“We found that, indeed, New Mexico was relatively arid,” Myers said. “But the surprising part was that the Wyoming locality was more arid and had less rainfall than New Mexico, even though it was at a higher latitude, and above the mid-latitude arid belt. And the Montana locality, which is not far from the Wyoming locality, had the highest rainfall of all three. And there’s a very abrupt transition between the two.”
During the Jurassic, the Morrison was between 30 degrees north and 45 degrees north, which is about five degrees south of where it sits now. Its sediments were deposited from 155 to 148 million years ago. Some areas show evidence of a marine environment, but most were continental. The mean average precipitation determined for the Jurassic doesn’t match our modern distribution, Myers said.
Study underscores that understanding climate requires multiple approaches
Previously scientists speculated on the climate based on qualitative measures, such as types of soils or rocks, or types of sedimentary structures, and inferred climate from that.
“I tried to find quantitative information, but no one had done it,” Myers said. “There are entire volumes about Morrison paleoclimate, but not a single paper with quantitative estimates. Given the volume of important fossils that have come out of the Morrison, and how significant this formation is, it just struck me as important that it be done.”
Myers classified the fossil soils according to the Mack paleosol classification, and established the elemental composition of each one to determine how much weathering the paleosols had undergone.
“There are some elements, such as aluminum, that are not easily weathered out of soils,” Myers said. “There are others that are easily flushed out. We looked at the ratio of the elements, such as aluminum versus elements easily weathered. From that, we used the ratios to determine how weathered or not the soil was.”
These findings suggest that scientists must use different approaches to quantify paleoclimate, he said.
“It’s not enough to just look at soil types and draw conclusions about the paleoclimate,” Myers said. “It’s not even enough to look at rainfall in this quantitative fashion. There are numerous factors to consider.”
SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.
SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.
Tracks of an unknown mammal dating to the Early Cretaceous are discovered along with tracks of a crocodile and a dinosaur
The creature was about the size of a raccoon, researchers said. (Photo: Marco Marzola)
The research of an international team co-led by SMU paleontologist Louis L. Jacobs is receiving worldwide coverage for discovery of the first dinosaur tracks discovered in Angola, including those of a mysterious mammal from 118 million years ago.
Jacobs, a professor of earth sciences at SMU, is a former president of the Society of Vertebrate Paleontology. His research focus is the interrelationships of biotic and abiotic events through time.
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To book a live or taped interview with Louis Jacobs in the SMU News Broadcast Studio call SMU News at 214-768-7650 or email news@smu.edu.
His fieldwork is currently focused through Projecto PaleoAngola on the iconic, puzzle-like fit of Africa and South America, as viewed through the rocks and fossils of coastal Angola.
In the laboratory, Jacobs’ research utilizes advanced imaging and stable isotope techniques to investigate paleoenvironmental, biogeographic and phylogenetic issues of the Mesozoic and Cenozoic eras.
Polcyn is director of the Visualization Laboratory in SMU’s Department of Earth Sciences and an SMU research associate.
A world-recognized expert on the extinct marine reptile named Mosasaur, Polcyn’s research interests include the early evolution of Mosasauroidea and adaptations in secondarily aquatic tetrapods. Polcyn’s research also includes application of technology to problems in paleontology.
By Hannah Osborne
International Business Times
The tracks of a huge mysterious mammal dating to the Early Cretaceous period have been discovered in the world’s fourth-biggest diamond mine in Africa.
Dating to 118 million years ago, researchers discovered the tracks of a crocodile, a dinosaur and a large unknown mammal inside the Catoca Diamond Mine in Angola.
Over 70 tracks were uncovered by researcher from the PaleoAngola Project, a programme that researches vertebrate palaeontology in Angola.
The dinosaur tracks – the first to be found in the African nation – were from a sauropod and were discovered with a preserved skin impression. The crocodile, a crocodilomorph trackmaker, was from a group that includes all modern species.
However, the most important find was that of the large mammal. Researchers believe it was about the size of a raccoon – huge compared to all other mammals at the time, which were mostly no larger than a rat.
Marco Marzola, one of the study authors, told IBTimes UK there is no way of telling to what species the mystery mammal belongs as you cannot identify animals by their tracks – “the most you can say is that the track resembles the anatomy of that animal,” he explained.
“We cannot narrow down to a species but we can say they do belong to – they were made by an exceptionally large mammal – that we can say for sure.”
SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.
SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.
Weyand’s research on the limits of human and animal performance has led to featured appearances on the BBC, the Canadian Broadcasting Corporation, CNN, the Discovery Channel, the History Channel, NHK Television Japan, NPR and others.
Weyand, recognized worldwide as an expert in human running performance, worked with Roberts on the lab’s specially equipped treadmill — it can go up to 90 miles an hour — which can measure how forcefully an athlete’s feet hit the ground.
As an athlete runs, the lab’s ultra high-speed video system (normally used in the entertainment-animation-video game design industry) can capture 1,000 frames a second, delivering accurate and detailed data about a runner’s biomechanics.
In the lab’s most recent published study, “Key to speed? Elite sprinters are unlike other athletes — deliver forceful punch to ground,” the scientists found that the key to speed is how forcefully athletes hit the ground — not how quickly they reposition their legs. They found that at top speed the world’s fastest runners take just as long to reposition their legs as an average Joe.
Weyand is an expert in the locomotion of humans and other terrestrial animals with broad research interests that focus on the relationships between muscle function, metabolic energy expenditure, whole body mechanics and performance.
His research draws on the largely distinct traditions of human exercise physiology and comparative biomechanics to consider basic functional issues.
Weyand’s research on the limits of human and animal performance has led to featured appearances on the British Broadcasting Corporation, the Canadian Broadcasting Corporation, CNN, the Discovery Channel, the History Channel, NHK Television Japan, National Public Radio and others.
SMU is a nationally ranked private university in Dallas founded 100 years ago. Today, SMU enrolls nearly 11,000 students who benefit from the academic opportunities and international reach of seven degree-granting schools. For more information see www.smu.edu.
SMU has an uplink facility located on campus for live TV, radio, or online interviews. To speak with an SMU expert or book an SMU guest in the studio, call SMU News & Communications at 214-768-7650.
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