Sunday, March 31, 2019

April Fools Hoax Stories Could Offer Clues To Help Identify 'Fake News'






Studying April Fools hoax news stories could offer clues to spotting 'fake news' articles, new research reveals.

Academic experts in Natural Language Processing from Lancaster University who are interested in deception have compared the language used within written April Fools hoaxes and fake news stories.

They have discovered that there are similarities in the written structure of humorous April Fools hoaxes - the spoof articles published by media outlets every April 1st - and malicious fake news stories.

The researchers have compiled a novel dataset, or corpus, of more than 500 April Fools articles sourced from more than 370 websites and written over 14 years.

Credit: Lars Andersen / Wikimedia Commons

"April Fools hoaxes are very useful because they provide us with a verifiable body of deceptive texts that give us an opportunity to find out about the linguistic techniques used when an author writes something fictitious disguised as a factual account," said Edward Dearden from Lancaster University, and lead-author of the research. "By looking at the language used in April Fools and comparing them with fake news stories we can get a better picture of the kinds of language used by authors of disinformation."

A comparison of April Fools hoax texts against genuine news articles written in the same period - but not published on April 1st - revealed stylistic differences.

Researchers focused on specific features within the texts, such as the amount of details used, vagueness, formality of writing style and complexity of language.

They then compared the April Fools stories with a 'fake news' dataset, previously compiled by a different team of researchers.

Although not all of the features found in April Fools hoaxes were found to be useful for detecting fake news, there were a number of similar characteristics found across both.

They found April Fools hoaxes and fake news articles tend to contain less complex language, an easier reading difficulty, and longer sentences than genuine news.

Important details for news stories, such as names, places, dates and times, were found to be used less frequently within April Fools hoaxes and fake news. However, proper nouns, such as the names of prominent politicians 'Trump' or 'Hillary', are more abundant in fake news than in genuine news articles or April Fools, which have significantly fewer.

First person pronouns, such as 'we', are also a prominent feature for both April Fools and fake news. This goes against traditional thinking in deception detection, which suggests liars use fewer first person pronouns.

  • The researchers found that April fools hoax stories, when compared to genuine news:
  • Are generally shorter in length
  • Use more unique words
  • Use longer sentences
  • Are easier to read
  • Refer to vague events in the future
  • Contain more references to the present
  • Are less interested in past events
  • Contain fewer proper nouns
  • Use more first person pronouns

Fake news stories, when compared to genuine news:
  • Are shorter in length
  • Are easier to read
  • Use simplistic language
  • Contain fewer punctuation marks
  • Contain more proper nouns
  • Are generally less formal - use more first names such as 'Hillary' and contain more profanity and spelling mistakes
  • Contain very few dates
  • Use more first person pronouns

The researchers also created a machine learning 'classifier' to identify if articles are April Fools hoaxes, fake news or genuine news stories. The classifier achieved a 75 per cent accuracy at identifying April Fools articles and 72 per cent for identifying fake news stories. When the classifier was trained on April Fools hoaxes and set the task of identifying fake news it recorded an accuracy of more than 65 per cent.

Dr Alistair Baron, co-author of the paper, said: "Looking at details and complexities within a text are crucial when trying to determine if an article is a hoax. Although there are many differences, our results suggest that April Fools and fake news articles share some similar features, mostly involving structural complexity.

"Our findings suggest that there are certain features in common between different forms of disinformation and exploring these similarities may provide important insights for future research into deceptive news stories."

The research has been outlined in the paper 'Fool's Errand: Looking at April Fools Hoaxes as Disinformation through the Lens of Deception and Humour', which will be presented at the 20th International Conference on Computational Linguistics and Intelligent Text Processing, to be held in La Rochelle in April.



Contacts and sources:\
Ian Boydon
Lancaster University

Citation:



Saturday, March 30, 2019

Study: Exercise Is More Critical Than Diet to Maintain Weight Loss for Previously Overweight

Physical activity helps to prevent weight regain when previously overweight.

A new study from the University of Colorado Anschutz Health and Wellness Center (AHWC) at the CU Anschutz Medical Campus revealed physical activity does more to maintain substantial weight loss than diet.

Exercise
Credit: University of Colorado Anschutz Medical Campus

The study, published in the March issue of Obesity, was selected as the Editor’s Choice article.


Danielle Ostendorf, PhD, a postdoctoral fellow at the CU Anschutz Health and Wellness Center
Credit: University of Colorado Anschutz Medical Campus

“This study addresses the difficult question of why so many people struggle to keep weight off over a long period. By providing evidence that a group of successful weight-loss maintainers engages in high levels of physical activity to prevent weight regain – rather than chronically restricting their energy intake – is a step forward to clarifying the relationship between exercise and weight-loss maintenance,” said Danielle Ostendorf, PhD, a postdoctoral fellow at the CU Anschutz Health and Wellness Center.

The findings reveal that successful weight-loss maintainers rely on physical activity to remain in energy balance (rather than chronic restriction of dietary intake) to avoid weight regain. In the study, successful weight-loss maintainers are individuals who maintain a reduced body weight of 30 pounds or more for over a year.

Key findings include:
The total calories burned (and consumed) each day by weight-loss maintainers was significantly higher (300 kcal/day) compared with that in individuals with normal body weight controls but was not significantly different from that in the individuals with overweight/obesity.

Notably, of the total calories burned, the amount burned in physical activity by weight-loss maintainers was significantly higher (180 kcal/day) compared with that in both individuals of normal body weight and individuals with overweight/obesity. Despite the higher energy cost of moving a larger body mass incurred by individuals with overweight/obesity, weight-loss maintainers were burning more energy in physical activity, suggesting they were moving more.

This is supported by the fact that the weight-loss maintainer group also demonstrated significantly higher levels of steps per day (12,000 steps per day) compared to participants at a normal body weight (9,000 steps per day) and participants with overweight/obesity (6,500 steps per day).

“Our findings suggest that this group of successful weight-loss maintainers are consuming a similar number of calories per day as individuals with overweight and obesity but appear to avoid weight regain by compensating for this with high levels of physical activity,” said Victoria A. Catenacci, MD, a weight management physician and researcher at CU Anschutz Medical Campus.

Victoria A. Catenacci, MD, a weight management physician and researcher at CU Anschutz Medical Campus
Credit: University of Colorado Anschutz Medical Campus


The study looked at successful weight-loss maintainers compared to two other groups: controls with normal body weight (Body Mass Index (BMI) similar to the current BMI of the weight-loss maintainers); and controls with overweight/obesity (whose current BMI was similar to the pre-weight-loss BMI of the maintainers). The weight-loss maintainers had a body weight of around 150 pounds, which was similar to the normal weight controls, while the controls with overweight and obesity had a body weight of around 213 pounds.

This study is one of the few to measure total daily energy expenditure in weight-reduced individuals using the gold standard doubly labeled water method. This method allows researchers to precisely determine an individual’s energy expenditure through collecting urine samples over one to two weeks after people are given a dose of doubly labeled water. Doubly labeled water is water in which both the hydrogen and the oxygen atoms have been replaced (i.e. labeled) with an uncommon isotope of these elements for tracing purposes.

The measure of total daily energy expenditure from doubly labeled water also provides an estimate of energy intake when people are weight stable, as they were in this study. Prior studies used questionnaires or diet diaries to measure energy intake, which have significant limitations.

The researchers also measured each individual’s resting metabolic rate in order to understand how much of the total daily energy expenditure is from energy expended at rest versus energy expended during physical activity. Prior studies used self-reported measures or activity monitors to measure physical activity, which are techniques that cannot provide the same accuracy.

The findings are consistent with results from the longitudinal study of “The Biggest Loser” contestants, where physical activity energy expenditure was strongly correlated with weight loss and weight gain after six years.




Contacts and sources:
Julia Milzer
University of Colorado Anschutz Medical Campus



The Minuscule Movements That Keep Us from Falling When Running



Maybe running comes easy, each stride pleasant and light. Maybe it comes hard, each step a slog to the finish. Either way, the human body is constantly calibrating, making microscopic adjustments to keep us from falling as we weekend-warrior our way to greatness.

running image
Credit: OSU

Runners constantly—and unconsciously—make minor corrections to their running form to keep their bodies upright, a recent study has found.

“You might think running is just a repetition of identical steps, and it might look like that to the naked eye,” said Nidhi Seethapathi, lead author of the study. “But actually, there are really small errors that happen when you run, and you have to constantly correct to avoid falling down. Our muscles and our senses are not perfect, and that leads to errors. If we didn’t correct for these self-generated errors, we would fall. Our study investigates how people correct such errors.”



The study was part of Seethapathi’s doctoral thesis in mechanical and aerospace engineering at The Ohio State University and was published earlier this month in the journal eLife. She has since accepted a postdoctoral position at The University of Pennsylvania.


“The tasks that your body does almost subconsciously have all these tiny movements behind them,” said Manoj Srinivasan, a co-author of the study and associate professor of mechanical and aerospace engineering at Ohio State. “Those little movements were what we were looking to understand.”



To understand how humans run without falling, the research team put volunteers on a treadmill and had them run at three different constant speeds. The team monitored and measured motion in each runner’s torso, the placement of each footstep and the force with which the leg pushes against the ground. The volunteers were average runners—not couch potatoes, but not marathoners, either.

They found that those runners automatically corrected for minor deviations in the movement of their torsos—their center of mass—by making slight changes to the place each footstep landed and by making miniscule adjustments to the amount of force with which their leg hit the ground. Seethapathi and Srinivasan found that they could predict how runners would change their footsteps or force by noting changes in the location of their torsos.''


Nidhi Seethapathi

Credit: OSU

They also found that runners, by and large, corrected imperfections in a step by their very next step, indicating that the human body has the ability to “fix” its running gait in order to stay upright. And their research showed that imperfections in a running stride that would have caused a runner to fall to the side were corrected more quickly than errors that would have caused a runner to topple forward or backward.

None of the errors examined in this study included external factors—a crack in pavement, for example, or a tree root on a trail. But what they did show was the human body’s great capacity for keeping itself upright while moving—something that robots, in general, struggle to do.

“We try to work at the intersection of robotics and human movement,” Seethapathi said, “in that we use metrics that are traditionally used in robotics on human movement and then take inspiration from humans to inform robotic movement.”

Manoj Srinivasan

Credit: OSU

The study’s findings could be used to engineer robots that are able to walk or run without toppling over, or to build an exoskeleton that moves more intuitively with the human body, Srinivasan said.

“In terms of movement, humans are just vastly superior to current robots,” Srinivasan said. “Our research is sort of reverse engineering the human body to understand how humans and animals control their bodies to do these amazing tasks. While walking and running maybe don’t sound amazing to people—because it is something most humans do almost every day—there have been a lot of technical challenges to making a robot that can walk or run without falling over, or to building an exoskeleton, for example, that can help a human regain movement while recovering from a stroke.”

An exoskeleton is exactly what it sounds like: A mechanical skeleton, or parts of a skeleton, that people wear to help the human body do everything from lift heavy objects to regain movement after an injury or stroke.

This study builds on previous research in Srinivasan’s lab that examined the ways humans walk.




Contacts and sources:
Laura Arenschield
Ohio State University


Citation: Step-to-step variations in human running reveal how humans run without falling.
Nidhi Seethapathi, Manoj Srinivasan. eLife, 2019; 8 DOI: 10.7554/eLife.38371

Changes in Onset of Spring Linked to More Allergies Across the US

Human-induced climate change is disrupting nature’s calendar, including when plants bloom and the spring season starts, and new research from the University of School of Public Health suggests we’re increasingly paying the price for it in the form of seasonal allergies.

The study, based on over 300,000 respondents between 2002 and 2013, shows that seasonal allergic rhinitis, or hay fever, increases when the timing of spring “greenup” changes. The findings were published today in the journal PLOS ONE.

Hay fever, or “seasonal allergic rhinitis,” affects 25 million adults in the United States and results in $11.2 billion in related medical expenses annually.
Woman with tissue on her nose
Credit: UMD

“We found that areas where the onset of spring was earlier than normal had 14% higher prevalence of hay fever,” said Associate Professor Amir Sapkota in the Maryland Institute for Applied Environmental Health. “Surprisingly, we also found similar risk in areas where the onset of spring was much later than what is typical for that geographic location,” he added.

The study provides the first national-level quantitative data showing how ongoing climate change is increasing the allergic disease burden in the United States. Hay fever, or “seasonal allergic rhinitis,” affects 25 million adults in the United States and results in $11.2 billion in related medical expenses annually.

Dr. Sapkota and his team used satellite data collected by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) to identify the start of the spring season throughout the US and linked these data to National Health Interview Survey data collected by the Centers for Disease Control and Prevention (CDC).

“Previous studies have shown that plant phenology is highly dependent on temperature. As such, it is one of the most sensitive indicators of how our ecosystem is responding to climate change,” said Dr. Chengsheng Jiang, co-author of the paper. “We show that such climate change-driven ecological changes are directly linked to allergic disease burden in the United States. Even a relatively small change in the timing of tree flowering can have a significant economic impact given that 25 million American adults already suffer from hay fever each year.”

The reason for increased hay fever when spring arrives early seems to be related to pollen exposure. An earlier onset of spring means trees flower sooner and create a longer season for tree pollen, which is the major source of spring seasonal allergens. But a very late onset of spring may mean many species of trees simultaneously burst in bloom, blasting allergy sufferers with a high concentration of pollen for a shorter duration.

Dr. Sapkota suggests this is yet another example of how climate change is impacting burden of allergic disease right here in our backyard. Given that climate change is projected to intensify, Dr. Sapkota argues such data are critical to inform public health adaptation strategies, including early warning systems. “Climate change impacts our health in more ways than we can imagine. We need community-specific adaptation strategies to increase resilience and minimize disease burden associated with climate change,” he urged.
Contacts and sources:
Amir Sapkota, Chengsheng Jiang
University of Maryland


Citation: . Associations between alteration in plant phenology and hay fever prevalence among US adults: Implication for changing climate.
Amir Sapkota, Raghu Murtugudde, Frank C. Curriero, Crystal R. Upperman, Lewis Ziska, Chengsheng Jiang PLOS ONE, 2019; 14 (3): e0212010 DOI: 10.1371/journal.pone.0212010



Fluorescence Discovered in Brazilian Frog

Pumpkin toadlets (also called Brachycephalus ephippium) are tiny, brightly-colored, and poisonous frogs that can be found in the Brazilian Atlantic forest. During the mating season, they can be seen by day walking around the forest and producing soft buzzing calls in search of a mate.



An international team of researchers led by NYU Abu Dhabi Postdoctoral Associate Sandra Goutte was studying the acoustic communications of these miniature frogs. When they discovered that Brachycephalusephippium could not hear its own mating calls, they searched for alternative visual signals the frogs could use to communicate instead. Unexpectedly, when they shone an ultra-violet (UV) lamp on the frogs, their backs and heads glowed intensely.

In a new paper published in the journal Scientific Reports, the researchers report that fluorescent patterns are created by bony plates lying directly beneath a very thin skin. In fact, the toadlet’s entire skeleton is highly fluorescent, but the fluorescence is only externally visible where the layer of skin tissue over the bones is very thin (about seven micrometers thick). The lack of dark skin pigment cells (which block the passage of light) and the thinness of the skin allow the ultraviolet light to pass through and excite the fluorescence of the bony plates of the skull. The fluorescent light is then reflected back from the frog’s bone, and can be seen as bluish-white markings by the observer if they have a UV lamp.

Under UV light, the Brazilian pumpkin toadlet glows bright blue (right).


Why Do They Glow?

“The fluorescent patterns are only visible to the human eye under a UV lamp. In nature, if they were visible to other animals, they could be used as intra-specific communication signals or as reinforcement of their aposematic coloration, warning potential predators of their toxicity,” said Goutte. “However, more research on the behavior of these frogs and their predators is needed to pinpoint the potential function of this unique luminescence.”

The researchers compared the skeletons of the two species of pumpkin toadlets to closely related, non-fluorescent species. The pumpkin toadlets’ bones proved to be much more fluorescent. Pumpkin toadlets are diurnal, and in their natural habitat, the UV or near-UV components of daylight might be able to create fluorescence at a level detectable by certain species.


Contacts and sources:
Kate Chandler / Farah Shamma
New York University


Citation: Intense bone fluorescence reveals hidden patterns in pumpkin toadlets.
Sandra Goutte, Matthew J. Mason, Marta M. Antoniazzi, Carlos Jared, Didier Merle, Lilian Cazes, Luís Felipe Toledo, Hanane el-Hafci, Stéphane Pallu, Hugues Portier, Stefan Schramm, Pierre Gueriau, Mathieu Thoury. Scientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-019-41959-8


Stunning Discovery Offers Glimpse Of Minutes Following ‘Dinosaur-Killer’ Chicxulub Impact



A study to be published Monday in the Proceedings of the National Academy of Sciences offers a scientific first: a detailed snapshot of the terrible moments right after the Chicxulub impact — the most cataclysmic event known to have befallen life on Earth.

 
Credit: KU News Service

At a site called Tanis in North Dakota’s Hell Creek Formation, a team of paleontologists whose headquarters are at the University of Kansas unearthed a motherlode of exquisitely-preserved animal and fish fossils — creatures that lived in and around a deeply chiseled river connected to the ancient Western Interior Seaway — that were killed suddenly in events triggered by the Chicxulub impact.

Robert DePalma and Peter Larson conduct field research in Tanis.
Courtesy Robert DePalma

The fossils were crammed into a “rapidly emplaced high-energy onshore surge deposit” along the KT boundary that contained associated ejecta and iridium impactite associated with the impact about 66 million years ago — an impact that eradicated about 75 percent of Earth’s animal and plant species.

“A tangled mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures was all packed into this layer by the inland-directed surge,” said lead author Robert DePalma, a KU doctoral student in geology who works in the KU Biodiversity Institute and Natural History Museum. “Timing of the incoming ejecta spherules matched the calculated arrival times of seismic waves from the impact, suggesting that the impact could very well have triggered the surge.”

DePalma, who discovered the fossil motherlode, said the find outlines how the impact could have devastated areas very far from the crater quite rapidly.

“A tsunami would have taken at least 17 or more hours to reach the site from the crater, but seismic waves — and a subsequent surge — would have reached it in tens of minutes,” he said.

DePalma and his colleagues describe the rushing wave that shattered the Tanis site as a “seiche.”

“As the 2011 Tohoku earthquake in Japan showed us, seismic shaking can cause surges far from the epicenter,” he said. “In the Tohoku example, surges were triggered nearly 5,000 miles away in Norway just 30 minutes after impact. So, the KT impact could have caused similar surges in the right-sized bodies of water worldwide, giving the first rapid ‘bloody nose’ to those areas before any other form of aftermath could have reached them.”

According to KU researchers, even before the surge arrived, Acipenseriform fish (sturgeon) found at the site already had inhaled tiny spherules ejected from the Chicxulub impact.

“The fish were buried quickly, but not so quickly they didn’t have time to breathe the ejecta that was raining down to the river,” said co-author David Burnham, preparator of vertebrate paleontology at the KU Biodiversity Institute. “These fish weren’t bottom feeders, they breathed these in while swimming in the water column. We’re finding little pieces of ejecta in the gill rakers of these fish, the bony supports for the gills. We don’t know if some were killed by breathing this ejecta, too.”

A shocked mineral from Tanis
Courtesy Robert DePalma

The number and quality of preservation of the fossils at Tanis are such that Burnham dubs it the “lagerstätte” of the KT event — paleontologist-speak for a landmark sedimentary deposit with exceptionally intact specimens. He said this is especially true as the fish are cartilaginous, not bony, and are less prone to fossilization.

“The sedimentation happened so quickly everything is preserved in three dimensions — they’re not crushed,” Burnham said. “It’s like an avalanche that collapses almost like a liquid, then sets like concrete. They were killed pretty suddenly because of the violence of that water. We have one fish that hit a tree and was broken in half.”

Indeed, the Tanis site contains many hundreds of articulated ancient fossil fish killed by the Chicxulub impact’s aftereffects and is remarkable for the biodiversity it reveals alone.

“At least several appear to be new species, and the others are the best examples known of their kind,” DePalma said. “Before now, fewer than four were known from the Hell Creek, so the site was already magnificently significant. But we quickly recognized that the surrounding sediment was deposited by a sudden, massive rush of water, and that the surge was directed inland, away from an ancient nearby seaway. When we noticed asteroid impact debris within the sediment and a compact layer of KT boundary clay resting on top of it from the long-term fallout, we realized that this unusual site was right at the KT boundary.”

According to Burnham, the fossil trove fills a void in scientific knowledge with vivid new detail.

A small fragment of a marine annemite shell found in the freshwater Tanis deposit.

Courtesy Robert DePalma

“We’ve understood that bad things happened right after the impact, but nobody’s found this kind of smoking-gun evidence,” he said. “People have said, ‘We get that this blast killed the dinosaurs, but why don’t we have dead bodies everywhere?’ Well, now we have bodies. They’re not dinosaurs, but I think those will eventually be found, too.”

DePalma said his find provides spectacular new detail to what is perhaps the most important event to ever affect life on Earth.

“It’s difficult not to get choked up and passionate about this topic,” he said. “We look at moment-by-moment records of one of the most notable impact events in Earth’s history. No other site has a record quite like that. And this particular event is tied directly to all of us — to every mammal on Earth, in fact. Because this is essentially where we inherited the planet. Nothing was the same after that impact. It became a planet of mammals rather than a planet of dinosaurs.

Micro-CT image showing cutaway of clay-altered ejecta spherule with internal core of unaltered impact glass.
Courtesy Robert DePalma

"As human beings, we descended from a lineage that literally survived in the ashes of what was once the glorious kingdom of the dinosaurs. And we’re the only species on the planet that has ever been capable of learning from such an event to the benefit of ourselves and every other organism in our world.”

At KU, DePalma and Burnham worked with Loren Gurche of the Biodiversity Institute. Other co-authors are Jan Smit and Klaudia Kuiper of VU University Amsterdam; Phillip Manning of the University of Manchester; Anton Oleinik of Florida Atlantic University; Peter Larson of the Black Hills Institute of Geological Research Inc.; Florentin Maurrasse of Florida International University; Johan Vellekoop of VU Leuven; and Mark A. Richards and Walter Alvarez of the University of California at Berkeley. 

 




Contacts and sources:
Brendan M. Lynch
The University of Kansas

Citation:



First Lambeosaurine Dinosaur from the Arctic in Alaska Discovered



Paleontologists from Hokkaido University in Japan, in cooperation with paleontologists from the Perot Museum of Nature and Science in Dallas, Texas, have discovered the first-confirmed occurrence of a lambeosaurine (crested 'duck-billed' dinosaur) from the Arctic - part of the skull of a lambeosaurine dinosaur from the Liscomb Bonebed (71-68 Ma) found on Alaska's North Slope. The bonebed was previously known to be rich in hadrosaurine hadrosaurids (non-crested 'duck-billed' dinosaurs).

The discovery proves for the first time that lambeosaurines inhabited the Arctic during the Late Cretaceous.*

Credit - Illustration by Masato Hattori

The discovery proves for the first time that lambeosaurines inhabited the Arctic during the Late Cretaceous. In addition, the numeric abundance of hadrosaurine fossils compared to the lambeosaurine fossils in the marine-influenced environment of the Liscomb Bonebed suggests the possibility that hadrosaurines and lambeosaurines had different habitat preferences.

The paleontologists' findings were published today in Scientific Reports, an open-access, multi-disciplinary journal from Nature Research dedicated to constructive, inclusive and rigorous peer review. The paper - entitled "The first definite lambeosaurine bone from the Liscomb Bonebed of the Upper Cretaceous Prince Creek Formation, Alaska, United States" - is co-authored by Yoshitsugu Kobayashi, Ph.D., and Ryuji Takasaki, of Hokkaido University, in cooperation with Anthony R. Fiorillo, Ph.D., of the Perot Museum of Nature and Science. Other authors are Ronald Tykoski, Ph.D. of the Perot Museum and Paul McCarthy, Ph.D., of the University of Alaska.

The paper can be read in Scientific Reports here.

"This new discovery illustrates the geographic link between lambeosaurines of North America and the Far East," said Takasaki. "Hopefully, further work in Alaska will reveal how closely the dinosaurs of Asia and North America are connected."

The newly discovered fossil, which is housed in the collections of the Perot Museum of Nature and Science, is a supraoccipital, one of the bones that forms the braincase. The new supraoccipital differs from those of hadrosaurines by the presence of large supraoccipital bosses and it's short, front-to-back length. Since these features are commonly seen in other members of Lambeosaurinae, the newly discovered supraoccipital was assigned to that group.

"This first definitive evidence of a crested hadrosaur in the Cretaceous Arctic tells us that we still have much to learn about the biodiversity and the biologically productive environments of the ancient north, and that the story these fossils tell us is continually evolving," adds Dr. Fiorillo.

Background. The Arctic is an extreme environment that is low in temperature, lacks sunlight during winters, and has seasonally limited food resources. Though it was warmer during the Late Cretaceous, the Arctic was surely one of the most challenging places to live for large vertebrates at the time. The Prince Creek Formation on the North Slope of Alaska is a world-famous rock unit for studying dinosaurs of the ancient Arctic. Because the dinosaurs found there lived in the ancient Arctic, rather than tropical or sub-tropical conditions, these dinosaurs challenge much of what we think we know about dinosaurs. The Liscomb Bonebed (71-68 Ma), which was deposited near the ancient Arctic shoreline, is especially rich in dinosaur bones, with more than 6,000 bones collected from it thus far.

More than 99% of dinosaur fossils known from the Liscomb Bonebed are hadrosaurs, a group of large, duck-billed herbivorous dinosaurs who lived during the Late Cretaceous and were found throughout much of the northern hemisphere. All of the hadrosaur fossils from the Liscomb Bonebed were long considered to belong to a hadrosaurine duck-billed dinosaur called Edmontosaurus. Up until now, all of the hadrosaurids known from across the Arctic, including those from the Liscomb Bonebed, were considered to belong to crest-less hadrosaurines.

The discovery of a fossil from a lambeosaurine hadrosaurid in the Liscomb Bonebed is historically important for Japanese paleontologists. The first "Japanese" dinosaur, Nipponosaurus, is a lambeosaurine hadrosaur. Based on the new discovery, Hokkaido University and the Perot Museum together used this discovery to further investigate the ecology of the Arctic hadrosaurids.

Significance

1. The first Arctic lambeosaurine. The new discovery indicates Arctic inhabitance and adaptation of lambeosaurines for the first time. In addition, the fossil's morphological similarities to the same bone in the skull of southern Canadian lambeosaurines suggest faunal interactions between the Arctic and the mid-latitudes.

2. Implication on habitat preferences. While the Liscomb Bonebed is known for numerous hadrosaurine fossils, the newly discovered bone represents the only definite lambeosaurine fossil from the site. The same trend is also known in mid-latitude localities of North America and eastern Asia, which were also deposited in near-shore environments. On the other hand, more lambeosaurine fossils are found in deposits laid down in inland environments. Therefore, we hypothesize that lambeosaurines favored inland environments, while hadrosaurines preferred coastal environments, a trend likely to have been independent of latitude. Different habitat preferences might have been a strategy to avoid excessive competition between the two groups of 'duck-billed' dinosaurs.

Future plans. Although the new discovery reveals Arctic inhabitance by lambeosaurines, more specific taxonomic status and potential functional adaptations to the severe Arctic environment remain unknown due to incompleteness of the specimen. Additional excavation and further research will help answer these questions.



Contacts and sources:
Becky Mayad
Perot Museum of Nature and Science 


Citation: The First Definite Lambeosaurine Bone From the Liscomb Bonebed of the Upper Cretaceous Prince Creek Formation, Alaska, United States Ryuji Takasaki, Anthony R. Fiorillo, Yoshitsugu Kobayashi, Ronald S. Tykoski & Paul J. McCarthy Scientific Reportsvolume 9, Article number: 5384 (2019) https://www.nature.com/articles/s41598-019-41325-8 http://dx.doi.org/10.1038/s41598-019-41325-8



Ancestral Memories? Seeds Inherit Memories from Their Mother


UNIGE researchers demonstrate that maternal and environmental factors control of seed dormancy is carried out through novel epigenetic mechanisms.

Seeds remain in a dormant state - a temporary blockage of their germination - as long as environmental conditions are not ideal for germination. The depth of this sleep, which is influenced by various factors, is inherited from their mother, as researchers from the University of Geneva (UNIGE), Switzerland, had previously shown.

Seed of Arabidopsis thaliana at the beginning of germination.

Credit: © UNIGE / Sylvain Loubéry

Today, they reveal in the journal eLife how this maternal imprint is transmitted through small fragments of so-called ‘interfering’ RNAs, which inactivate certain genes. The biologists also reveal that a similar mechanism enables to transmit another imprint, that of the temperatures present during the development of the seed. The lower this temperature was, the higher the seed’s dormancy level will be. This mechanism allows the seed to optimize the timing of its germination. The information is then erased in the germinated embryo, so that the next generation can store new data on its environment.

Dormancy is implemented during seed development in the mother plant. This property allows the seeds to germinate during the appropriate season, to prevent all the offspring of a plant from developing in the same place and competing for limited resources, and to promote plant dispersal. Seeds also lose their dormancy at variable times. “Subspecies of the same plant can have different levels of dormancy depending on the latitudes at which they are produced, and we wanted to understand why”, explains Luis Lopez-Molina, Professor at the Department of Botany and Plant Biology of the UNIGE Faculty of Science.



The paternal gene is silenced

Like all organisms with sexual reproduction, the seed receives two versions of each gene, a maternal and a paternal allele, which may have different levels of expression. The UNIGE biologists had shown in 2016 that the dormancy levels of Arabidopsis thaliana, a model organism used in laboratories, are inherited from the mother. Indeed, in the seed, the level of expression of a dormancy regulating gene called allantoinase (ALN) is the same as that of the maternal allele. This implies that it is the maternal allele of ALN that is mainly expressed, to the detriment of the paternal allele.

In the current study, the researchers show that this maternal imprint is transmitted by an epigenetic mechanism, which influences the expression of certain genes without altering their sequence. The paternal allele of ALN is ‘silenced’ by biochemical modifications called methylations, which are carried out in the promoter region of the gene in order to inactivate it.

“These methylations are themselves the result of a process in which different enzymatic and factor complexes are involved, as well as small fragments of so-called ‘interfering’ RNA. This is a unique example of genomic imprinting, because it is made in the absence of the enzyme usually responsible for methylation”, says Mayumi Iwasaki, researcher in the Geneva group and the first author of the article.



The imprint of past cold prevents the seed from awakening

The environmental conditions present during the seed formation also leave their mark, as its dormancy level increases with decreasing temperatures. “We have discovered that, in this case, both alleles of the ALN gene are strongly repressed in the seed. This is due to a similar epigenetic mechanism, but not all of the actors are the same as those used to silence the paternal allele”, says Luis Lopez-Molina.

This imprint of the cold enables the seed to keep information on past temperatures, in order to include them in the choice of the optimal time of germination. After germination, the ALN gene is reactivated in the embryo. The memory of the cold will then be cleared, allowing the counters to be reset for the next generation.

“Studying how maternal and environmental factors cause dormant seeds to awaken is of crucial importance for agriculture, especially to prevent early germination in an environment subject to climate change”, concludes Mayumi Iwasaki. The ecological stakes are also high, because increasing temperatures could reduce the dormancy of the seed bank and thus modify the distribution of plant species under a given latitude. This would have multiple consequences, both direct and indirect, for native animal and plant species.



Contacts and sources:
Luis Lopez-Molina
Université de Genève (UNIGE)


Citation: Non-canonical RNA-directed DNA methylation participates in maternal and environmental control of seed dormancy
Mayumi Iwasaki, Lena Hyvärinen, Urszula Piskurewicz, Luis Lopez-Molina. . eLife, 2019; 8 DOI: 10.7554/eLife.37434



66 Million-Year-Old Deathbed Linked To Dinosaur-Killing Meteor

A meteor impact 66 million years ago generated a tsunami-like wave in an inland sea that killed and buried fish, mammals, insects and a dinosaur, the first victims of Earth’s last mass extinction event. The death scene from within an hour of the impact has been excavated at an unprecedented fossil site in North Dakota.
graphic of dinosaur caught in tsunami
Graphics and photos courtesy of Robert DePalma

The beginning of the end started with violent shaking that raised giant waves in the waters of an inland sea in what is now North Dakota.

Then, tiny glass beads began to fall like birdshot from the heavens. The rain of glass was so heavy it may have set fire to much of the vegetation on land. In the water, fish struggled to breathe as the beads clogged their gills.

The heaving sea turned into a 30-foot wall of water when it reached the mouth of a river, tossing hundreds, if not thousands, of fresh-water fish — sturgeon and paddlefish — onto a sand bar and temporarily reversing the flow of the river. Stranded by the receding water, the fish were pelted by glass beads up to 5 millimeters in diameter, some burying themselves inches deep in the mud. The torrent of rocks, like fine sand, and small glass beads continued for another 10 to 20 minutes before a second large wave inundated the shore and covered the fish with gravel, sand and fine sediment, sealing them from the world for 66 million years.

This unique, fossilized graveyard — fish stacked one atop another and mixed in with burned tree trunks, conifer branches, dead mammals, mosasaur bones, insects, the partial carcass of a Triceratops, marine microorganisms called dinoflagellates and snail-like marine cephalopods called ammonites — was unearthed by paleontologist Robert DePalma over the past six years in the Hell Creek Formation, not far from Bowman, North Dakota. The evidence confirms a suspicion that nagged at DePalma in his first digging season during the summer of 2013 — that this was a killing field laid down soon after the asteroid impact that eventually led to the extinction of all ground-dwelling dinosaurs. The impact at the end of the Cretaceous Period, the so-called K-T boundary, exterminated 75 percent of life on Earth.

“This is the first mass death assemblage of large organisms anyone has found associated with the K-T boundary,” said DePalma, curator of paleontology at the Palm Beach Museum of Natural History in Florida and a doctoral student at the University of Kansas. “At no other K-T boundary section on Earth can you find such a collection consisting of a large number of species representing different ages of organisms and different stages of life, all of which died at the same time, on the same day.”

Fossilized fish piled one atop another, suggesting that they were flung ashore and died stranded together on a sand bar after the seiche withdrew.

Credit: University of California - Berkeley, Robert DePalma


In a paper to be published next week in the journal Proceedings of the National Academy of Sciences, he and his American and European colleagues, including two University of California, Berkeley, geologists, describe the site, dubbed Tanis, and the evidence connecting it with the asteroid or comet strike off Mexico’s Yucatan Peninsula 66 million years ago. That impact created a huge crater, called Chicxulub, in the ocean floor and sent vaporized rock and cubic miles of asteroid dust into the atmosphere. The cloud eventually enveloped Earth, setting the stage for Earth’s last mass extinction.

“It’s like a museum of the end of the Cretaceous in a layer a meter-and-a-half thick,” said Mark Richards, a UC Berkeley professor emeritus of earth and planetary science who is now provost and professor of earth and space sciences at the University of Washington.

Richards and Walter Alvarez, a UC Berkeley Professor of the Graduate School who 40 years ago first hypothesized that a comet or asteroid impact caused the mass extinction, were called in by DePalma and Dutch scientist Jan Smit to consult on the rain of glass beads and the tsunami-like waves that buried and preserved the fish. The beads, called tektites, formed in the atmosphere from rock melted by the impact.
Tsunami vs. seiche

Richards and Alvarez determined that the fish could not have been stranded and then buried by a typical tsunami, a single wave that would have reached this previously unknown arm of the Western Interior Seaway no less than 10 to 12 hours after the impact 3,000 kilometers away, if it didn’t peter out before then. Their reasoning: The tektites would have rained down within 45 minutes to an hour of the impact, unable to create mudholes if the seabed had not already been exposed.

Walter Alvarez and Robert DePalma at the Tanis outcrop in North Dakota.

Credit: University of California - Berkeley, Robert DePalma

Instead, they argue, seismic waves likely arrived within 10 minutes of the impact from what would have been the equivalent of a magnitude 10 or 11 earthquake, creating a seiche (pronounced saysh), a standing wave, in the inland sea that is similar to water sloshing in a bathtub during an earthquake. Though large earthquakes often generate seiches in enclosed bodies of water, they’re seldom noticed, Richards said. The 2011 Tohoku quake in Japan, a magnitude 9.0, created six-foot-high seiches 30 minutes later in a Norwegian fjord 8,000 kilometers away.

“The seismic waves start arising within nine to 10 minutes of the impact, so they had a chance to get the water sloshing before all the spherules (small spheres) had fallen out of the sky,” Richards said. “These spherules coming in cratered the surface, making funnels — you can see the deformed layers in what used to be soft mud — and then rubble covered the spherules. No one has seen these funnels before.”

The tektites would have come in on a ballistic trajectory from space, reaching terminal velocities of between 100 and 200 miles per hour, according to Alvarez, who estimated their travel time decades ago.

“You can imagine standing there being pelted by these glass spherules. They could have killed you,” Richards said. Many believe that the rain of debris was so intense that the energy ignited wildfires over the entire American continent, if not around the world.

Tektites, 1 millimeter spheres of glass, recovered from the Tanis fossil bed.

Credit: University of California - Berkeley, Robert DePalma


“Tsunamis from the Chicxulub impact are certainly well-documented, but no one knew how far something like that would go into an inland sea,” DePalma said. “When Mark came aboard, he discovered a remarkable artifact — that the incoming seismic waves from the impact site would have arrived at just about the same time as the atmospheric travel time of the ejecta. That was our big breakthrough.”

At least two huge seiches inundated the land, perhaps 20 minutes apart, leaving six feet of deposits covering the fossils. Overlaying this is a layer of clay rich in iridium, a metal rare on Earth, but common in asteroids and comets. This layer is known as the K-T, or K-Pg boundary, marking the end of the Cretaceous Period and the beginning of the Tertiary Period, or Paleogene.
Iridium

In 1979, Alvarez and his father, Nobelist Luis Alvarez of UC Berkeley, were the first to recognize the significance of iridium that is found in 66 million-year-old rock layers around the world. They proposed that a comet or asteroid impact was responsible for both the iridium at the K-T boundary and the mass extinction.


Jan Smit, Mark Richards and Walter Alvarez at the North Dakota site of dinosaur-killing meteor’s first victims.

Credit: University of California - Berkeley, Robert DePalma

The impact would have melted the bedrock under the seafloor and pulverized the asteroid, sending dust and melted rock into the stratosphere, where winds would have carried them around the planet and blotted out the sun for months, if not years. Debris wold have rained down from the sky: not only tektites, but also rock debris from the continental crust, including shocked quartz, whose crystal structure was deformed by the impact.

The iridium-rich dust from the pulverized meteor would have been the last to fall out of the atmosphere after the impact, capping off the Cretaceous.

“When we proposed the impact hypothesis to explain the great extinction, it was based just on finding an anomalous concentration of iridium — the fingerprint of an asteroid or comet,” said Alvarez. “Since then, the evidence has gradually built up. But it never crossed my mind that we would find a deathbed like this.”

Key confirmation of the meteor hypothesis was the discovery of a buried impact crater, Chicxulub, in the Caribbean and off the coast of the Yucatan in Mexico, that was dated to exactly the age of the extinction. Shocked quartz and glass spherules were also found in K-Pg layers worldwide. The new discovery at Tanis is the first time the debris produced in the impact was found along with animals killed in the immediate aftermath of the impact.

Robert DePalma excavating at the Tanis fossil site in North Dakota.


“And now we have this magnificent and completely unexpected site that Robert DePalma is excavating in North Dakota, which is so rich in detailed information about what happened as a result of the impact,” Alvarez said. “For me, it is very exciting and gratifying!”
Tektites

Jan Smit, a retired professor of sedimentary geology from Vrije Universiteit in Amsterdam in The Netherlands who is considered the world expert on tektites from the impact, joined DePalma to analyze and date the tektites from the Tanis site. Many were found in near perfect condition embedded in amber, which at the time was pliable pine pitch.


Fish carcasses and two logs tossed together by the seiche created by seismic waves from the meteor impact.

Credit: University of California - Berkeley, Robert DePalma

“I went to the site in 2015 and, in front of my eyes, he (DePalma) uncovered a charred log or tree trunk about four meters long which was covered in amber, which acted as sort of an aerogel and caught the tektites when they were coming down,” Smit said. “It was a major discovery, because the resin, the amber, covered the tektites completely, and they are the most unaltered tektites I have seen so far, not 1 percent of alteration. We dated them, and they came out to be exactly from the K-T boundary.”

The tektites in the fishes’ gills are also a first.

“Paddlefish swim through the water with their mouths open, gaping, and in this net, they catch tiny particles, food particles, in their gill rakers, and then they swallow, like a whale shark or a baleen whale,” Smit said. “They also caught tektites. That by itself is an amazing fact. That means that the first direct victims of the impact are these accumulations of fishes.”

Smit also noted that the buried body of a Triceratops and a duck-billed hadrosaur proves beyond a doubt that dinosaurs were still alive at the time of the impact.

“We have an amazing array of discoveries which will prove in the future to be even more valuable,” Smit said. “We have fantastic deposits that need to be studied from all different viewpoints. And I think we can unravel the sequence of incoming ejecta from the Chicxulub impact in great detail, which we would never have been able to do with all the other deposits around the Gulf of Mexico.”

A perfectly preserved fish tail from Tanis deposit.

Credit: University of California - Berkeley, Robert DePalma


“So far, we have gone 40 years before something like this turned up that may very well be unique,” Smit said. “So, we have to be very careful with that place, how we dig it up and learn from it. This is a great gift at the end of my career. Walter sees it as the same.”

Co-authors with DePalma, Smit, Richards and Alvarez are David Burnham of the University of Kansas, Klaudia Kuiper of Vrije Universiteit, Phillip Manning of Manchester University in the United Kingdom, Anton Oleinik of Florida Atlantic University, Peter Larson of the Black Hills Institute of Geological Research in South Dakota, Florentin Maurrasse of Florida International University, Johan Vellekoop of Katholieke Universiteit Leuven in Belgium and Loren Gurche of the Palm Beach Museum of Natural History.


Contacts and sources:'
Robert Sanders
University of California - Berkeley

Citation: Prelude to Extinction: a seismically induced onshore surge deposit at the KPg boundary, North Dakota.
DePalma, Robert A.; Smit, Jan; Burnham, David; Kuiper, Klaudia; Manning, Phillip; Oleinik, Anton; Larson, Peter; Maurrasse, Florentin; Vellekoop, Johan; Richards, Mark A.; Gurche, Loren; Alvarez, Walter. PNAS, 2019


Friday, March 29, 2019

Woman with Novel Gene Mutation Lives Almost Pain-Free



A woman in Scotland can feel virtually no pain due to a mutation in a previously-unidentified gene, according to a research paper co-led by UCL.

She also experiences very little anxiety and fear, and may have enhanced wound healing due to the mutation, which the researchers say could help guide new treatments for a range of conditions, they report in the British Journal of Anaesthesia.

Credit: UCL

“We found this woman has a particular genotype that reduces activity of a gene already considered to be a possible target for pain and anxiety treatments,” said one of the study’s lead researchers, Dr James Cox (UCL Medicine).

“Now that we are uncovering how this newly-identified gene works, we hope to make further progress on new treatment targets.”

At age 65, the woman sought treatment for an issue with her hip, which turned out to involve severe joint degeneration despite her experiencing no pain. At age 66, she underwent surgery on her hand, which is normally very painful, and yet she reported no pain after the surgery. Her pain insensitivity was diagnosed by Dr Devjit Srivastava, Consultant in Anaesthesia and Pain Medicine at an NHS hospital in the north of Scotland and co-lead author of the paper.

The woman tells researchers she has never needed painkillers after surgery such as dental procedures.

She was referred to pain geneticists at UCL and the University of Oxford, who conducted genetic analyses and found two notable mutations. One was a microdeletion in a pseudogene, previously only briefly annotated in medical literature, which the researchers have described for the first time and dubbed FAAH-OUT. She also had a mutation in the neighbouring gene that controls the FAAH enzyme.

Further tests by collaborators at the University of Calgary, Canada, revealed elevated blood levels of neurotransmitters that are normally degraded by FAAH, further evidence for a loss of FAAH function.

The FAAH gene is well-known to pain researchers, as it is involved in endocannabinoid signalling central to pain sensation, mood and memory. The gene now called FAAH-OUT was previously assumed to be a ‘junk’ gene that was not functional. The researchers found there was more to it than previously believed, as it likely mediates FAAH expression.

Mice that do not have the FAAH gene have reduced pain sensation, accelerated wound healing, enhanced fear-extinction memory and reduced anxiety.

The woman in Scotland experiences similar traits. She notes that in her lifelong history of cuts and burns (sometimes unnoticed until she can smell burning flesh), the injuries tend to heal very quickly. She is an optimist who was given the lowest score on a common anxiety scale, and reports never panicking even in dangerous situations such as a recent traffic incident. She also reports memory lapses throughout life such as forgetting words or keys, which has previously been associated with enhanced endocannabinoid signalling.

The researchers say that it’s possible there are more people with the same mutation, given that this woman was unaware of her condition until her 60s.

“People with rare insensitivity to pain can be valuable to medical research as we learn how their genetic mutations impact how they experience pain, so we would encourage anyone who does not experience pain to come forward,” said Dr Cox.

The research team is continuing to work with the woman in Scotland, and are conducting further tests in cell samples, in order to better understand the novel pseudogene.

“We hope that with time, our findings might contribute to clinical research for post-operative pain and anxiety, and potentially chronic pain, PTSD and wound healing, perhaps involving gene therapy techniques,” said Dr Cox.

“The implications for these findings are immense,” said Dr Srivastava.

“One out of two patients after surgery today still experiences moderate to severe pain, despite all advances in pain killer medications and techniques since the use of ether in 1846 to first ‘annul’ the pain of surgery. There have already been unsuccessful clinical trials targeting the FAAH protein – while we hope the FAAH-OUT gene could change things particularly for post-surgical pain, it remains to be seen if any new treatments could be developed based on our findings.”

“The findings point towards a novel pain killer discovery that could potentially offer post-surgical pain relief and also accelerate wound healing. We hope this could help the 330 million patients who undergo surgery globally every year,” Dr Srivastava said.

“I would be elated if any research into my own genetics could help other people who are suffering,” the woman in Scotland commented.

“I had no idea until a few years ago that there was anything that unusual about how little pain I feel – I just thought it was normal. Learning about it now fascinates me as much as it does anyone else.”

Lead funding for the study came from the Medical Research Council and Wellcome.




Contacts and sources:Chris Lane
University College London

Citation: Microdeletion in a pseudogene identified in a patient with high anandamide concentrations and pain insensitivity.
Abdella M. Habib, Andrei L. Okorokov, Matthew N. Hill, Jose T. Bras, Man-Cheung Lee, Shengnan Li, Samuel J. Gossage, Marie van Drimmelen, Maria Morena, Henry Houlden, Juan D. Ramirez, David L.H. Bennett, Devjit Srivastava, James J. Cox. British Journal of Anaesthesia, 2019; DOI: 10.1016/j.bja.2019.02.019


A Bad Bout of Flu Triggers 'Taste Bud Cells' to Grow in the Lungs

Most people who weather an infection with influenza fully recover after a week or two. But for some, a severe case of the flu can actually reshape the architecture of their lungs and forever compromise their respiratory function.

With a surprising new finding, researchers from Penn have identified what they believe to be a major feature of this remodeling process. When the team examined the lungs of mice after a severe bout with flu, they found cells virtually identical to those found in taste buds. Tracing the origin of these "taste bud cells," also referred to as solitary chemosensory cells or tuft cells, the scientists found they arose from the same lineage of cells as those known to cause detrimental lung remodeling. With further study, the discovery may lend insight into possibilities for protecting lung function in people who experience severe influenza infections.

The discovery of tuft cells (in green) in mice lungs after flu gives researchers insights into how a bad respiratory infection may set the stage for certain inflammatory conditions, such as asthma. The cells, similar to those in taste buds, are named for the elongated microvilli which project from their surface.

Credit: Andrew Vaughan/University of Pennsylvania

"It was just really weird to see, because these cells are not in the lung at baseline," says senior author and team leader Andrew E. Vaughan, a biologist in Penn's School of Veterinary Medicine. "The closest they are normally is in the trachea. What we did was show where they're coming from and how this same rare cell type that gives you all this maladaptive remodeling of the lung after flu is also the source of these ectopic tuft cells."

The research was published this week in the American Journal of Physiology - Lung Cellular and Molecular Physiology.

Interested in how the lung can regenerate after injury, Vaughan and colleagues had been paying close attention for several years to how the lungs respond to flu. In 2015, they published a paper in Nature identifying a new class of cells, lineage negative epithelial progenitors, as those that give way to the reshaped lung tissue structure seen in the wake of serious lung infections. But they also noticed that this restructuring was accompanied by sustained inflammation, even long after the flu virus had been cleared from the body. Curious to explore the connection between lung remodeling and persistent inflammation, Vaughan reached out to otorhinolaryngologist Noam A. Cohen of Penn's Perelman School of Medicine and immunologist De'Broski R. Herbert of Penn Vet.

Together they took a closer look at what was happening after mice were exposed to a virulent infection with H1N1 influenza. While an acute infection with influenza evokes what's known as a Type 1 immune response in the body, the researchers found that the cell types and signaling markers that were elevated weeks after the animals' infections were characteristic of a Type 2 immune response, one more often associated with allergies, asthma, nasal polyps, and even hookworm infections.

"These hallmarks of a Type 2 immune response after flu were unexpected, and have gone largely unnoticed until very recently," Vaughan says.

From other studies of Type 2 immunity in the mouse gut, the researchers knew that tuft cells were required to orchestrate this type of response, so the researchers went looking for them in the lungs. "And lo and behold, there they were, all over the place," says Vaughan.

"We had been looking at these solitary chemosensory cells in patients with nasal polyps and found that they were massively increased in the noses of these patients," says Cohen. "Interestingly, one of the hallmarks of these cells is also found elevated in the lungs of asthmatics; nasal polyps are found in about 50 percent of patients with asthma. These recent findings may be a link between Type 2 inflammatory diseases, such as asthma, as well as nasal polyps, following a respiratory viral infection."

These tuft cells were found lining the airway and in the alveoli of the lungs, which are the same locations, the researchers noted, as cells responsible for post-influenza structural changes. By affixing a fluorescent label to lineage negative epithelial progenitor cells, they found these to be the precursors to both the tuft cells and the cells responsible for the long-term deficits in the function and structure of the lungs.

To understand what these solo "taste bud" cells were doing in the lungs post-influenza, the researchers tried activating them, using bitter compounds. This stimulation not only caused tuft cell numbers to expand, it also triggered acute inflammation. In lungs that had not been infected and therefore lacked the tuft cells, no such inflammation occurred.

The Penn team is eager to continue pursuing this line of research. "In the mice we'd like to look further to see how the presence of these cells affects the quality of regeneration after infection," Vaughan says. If one could harness their activity, he notes, perhaps there is a way to avoid the long-term detrimental remodeling that occurs after an infection.

They'll also be looking at human lung samples to confirm that the same phenomenon they see in mice also occurs in people who experience a severe respiratory infection. Vaughan says there are clues that this could be the case, such as evidence from histology. The presence of tuft cells, and their involvement in allergies and asthma, could also help explain why young children who acquire severe viral infections, such as respiratory syncytial virus are predisposed to developing asthma later in life.

And because the presence of tuft cells in the intestines has been shown to confer immunity to certain diseases, such as hookworm, the researchers want to see if that is the case for tuft cells in the lungs as well.


Contacts and sources:
Katherine Unger Baillie
University of Pennsylvania

Citation: Development of solitary chemosensory cells in the distal lung after severe influenza injury Chetan K Rane, Sergio R Jackson, Christopher F Pastore, Gan Zhao, Aaron I Weiner, Neil N Patel, De'broski R Herbert, Noam A. Cohen, and Andrew E Vaughan http://dx.doi.org/10.1152/ajplung.00032.2019


Thursday, March 28, 2019

Math Wizard Releases Projections for American and National League Baseball Divisions

NJIT Mathematical Sciences Professor and Associate Dean Bruce Bukiet has published his model's projections of how the standings should look at the end of Major League Baseball's regular season in 2019. For more than 20 years, Bukiet has applied mathematical models to compute the number of regular season games each Major League Baseball team should win. His mathematically derived projections have consistently compared well with those of so-called experts.

Bukiet bases his projections on a mathematical model he started developing in the late 1980s and has gone through several revisions. Among the many data points is a model of runner advancement. There are a possible 24 scenarios in which a batter may face a pitcher: three "out" situations (zero outs, one out, or two outs), and eight baserunner situations (no man on, man on first base, man on second base, man on third base, men on first and second base, men on second and third base, men on first and third base, and bases loaded). Calculating the probabilities of batter outcomes against opposing pitchers with the runner advancement model can enable one to forecast the results for each game, and thus the season.

Yankee Stadium New York City



Credit: User:manuelvieda / Wikimedia Commons

For this season, Bukiet's projections for the American League (AL) and National League (NL) are:

AL East - Yankees (105 wins)
AL Central - Indians (98 wins)
AL West - Astros (103 wins)

NL East - Nationals (99 wins)
NL Central - Brewers (90 wins)
NL West - Dodgers (105 wins)

His results have been noted in many publications and he has been predictions champion at baseballphd.net several times. See more results for his baseball modeling, including the projected wins for each of the Major League Baseball teams at http://web.njit.edu/~bukiet/baseball/baseball.html and at http://www.egrandslam.com.



Contacts and sources:
Tanya Klein 
NJIT  (New Jersey Institute of Technology)





Arctic Warming Contributes to Drought in Temperate Climates



When the Arctic warmed after the ice age 10,000 years ago, it created perfect conditions for drought.

According to new research led by a University of Wyoming scientist, similar changes could be in store today because a warming Arctic weakens the temperature difference between the tropics and the poles. This, in turn, results in less precipitation, weaker cyclones and weaker mid-latitude westerly wind flow -- a recipe for prolonged drought.

The temperature difference between the tropics and the poles drives a lot of weather. When those opposite temperatures are wider, the result is more precipitation, stronger cyclones and more robust wind flow. However, due to the Arctic ice melting and warming up the poles, those disparate temperatures are becoming closer.

“Our analysis shows that, when the Arctic is warmer, the jet stream and other wind patterns tend to be weaker,” says Bryan Shuman, a UW professor in the Department of Geology and Geophysics. “The temperature difference in the Arctic and the tropics is less steep. The change brings less precipitation to the mid-latitudes.”

Shuman is a co-author of a new study that is highlighted in a paper, titled “Mid-Latitude Net Precipitation Decreased With Arctic Warming During the Holocene,” published today (March 27) online in Nature, an international weekly science journal. The print version of the article will be published April 4.

Researchers from Northern Arizona University; Universite Catholique de Louvain in Louvain-In-Neuve, Belgium; the Florence Bascom Geoscience Center in Reston, Va.; and Cornell University also contributed to the paper.

“The Nature paper takes a global approach and relates the history of severe dry periods of temperature changes. Importantly, when temperatures have changed in similar ways to today (warming of the Arctic), the mid-latitudes -- particularly places like Wyoming and other parts of central North America -- dried out,” Shuman explains. “Climate models anticipate similar changes in the future.”

Currently, the northern high latitudes are warming at rates that are double the global average. This will decrease the equator-to-pole temperature gradient to values comparable with the early to middle Holocene Period, according to the paper.

This image shows the Arctic temperature trend between August 1981 and July 2009. Due to global warming, which is exacerbated at the Arctic, we see a significant warming over this 28 year period .
File:NASA-28yrs-Arctic-Warming.jpg
Credit: NASA

Shuman says his research contribution, using geological evidence, was helping to estimate how dry conditions have been in the past 10,000 years. His research included three water bodies in Wyoming: Lake of the Woods, located above Dubois; Little Windy Hill Pond in the Snowy Range; and Rainbow Lake in the Beartooth Mountains.

“Lakes are these natural recorders of wet and dry conditions,” Shuman says. “When lakes rise or lower, it leaves geological evidence behind.”

The researchers’ Holocene temperature analysis included 236 records from 219 sites. During the past 10,000 years, many of the lakes studied were lower earlier in history than today, Shuman says.

“Wyoming had several thousand years where a number of lakes dried up, and sand dunes were active where they now have vegetation,” Shuman says. “Expanding to the East Coast, it is a wet landscape today. But 10,000 years ago, the East Coast was nearly as dry as the Great Plains.”

The research group looked at the evolution of the tropic-to-pole temperature difference from three time periods: 100 years ago, 2,000 years ago and 10,000 years ago. For the last 100 years, many atmospheric records facilitated the analysis but, for the past 2,000 years or 10,000 years, there were fewer records available. Tree rings can help to expand studies to measure temperatures over the past 2,000 years, but lake deposits, cave deposits and glacier ice were studied to record prior temperatures and precipitation.

“This information creates a test for climate models,” Shuman says. “If you want to use a computer to make a forecast of the future, then it’s useful to test that computer’s ability to make a forecast for some other time period. The geological evidence provides an excellent test.”

The research was funded by the Science Foundation Arizona Bisgrove Scholar Award, the National Science Foundation and the state of Arizona’s Technology and Research Initiative Fund administered by the Arizona Board of Regents.

Contacts and sources:
Bryan Shuman
University of Wyoming

Citation:



In Ancient Oceans that Resembled Our Own, Oxygen Loss Triggered Mass Extinction



Roughly 430 million years ago, during the Earth’s Silurian Period, global oceans were experiencing changes that would seem eerily familiar today. Melting polar ice sheets meant sea levels were steadily rising, and ocean oxygen was falling fast around the world.

At around the same time, a global die-off known among scientists as the Ireviken extinction event devastated scores of ancient species. Eighty percent of conodonts, which resembled small eels, were wiped out, along with half of all trilobites, which scuttled along the seafloor like their distant, modern-day relative the horseshoe crab.

Now, for the first time, a Florida State University team of researchers has uncovered conclusive evidence linking the period’s sea level rise and ocean oxygen depletion to the widespread decimation of marine species. Their work highlights a dramatic story about the urgent threat posed by reduced oxygen conditions to the rich tapestry of ocean life.

Seth Young (left) and Jeremy Owens (right), assistant professors in the Department of Earth, Ocean and Atmospheric Science.
Newswise: In Ancient Oceans that Resembled Our Own, Oxygen Loss Triggered Mass Extinction
Credit: Stephen Bilenky

The findings from their study were published in the journal Earth and Planetary Science Letters.

Although other researchers had produced reams of data on the Ireviken event, none had been able to definitively establish a link between the mass extinction and the chemical and climatic changes in the oceans.

“The connection between these changes in the carbon cycle and the marine extinction event had always been a mystery,” said lead author Seth Young, an assistant professor in FSU’s Department of Earth, Ocean and Atmospheric Science.

To address this old and obstinate question, Young and his co-authors deployed new and innovative strategies. They developed an advanced multiproxy experimental approach using stable carbon isotopes, stable sulfur isotopes and iodine geochemical signatures to produce detailed, first-of-their-kind measurements for local and global marine oxygen fluctuation during the Ireviken event.

“Those are three separate, independent geochemical proxies, but when you combine them together you have a very powerful data set to unravel phenomena from local to global scales,” Young said. “That’s the utility and uniqueness of combining these proxies.”

Young and his team applied their multiproxy approach to samples from two geologically important field sites in Nevada and Tennessee, both of which were submerged under ancient oceans during the time of the extinction event. After analyzing their samples at the FSU-based National High Magnetic Field Laboratory, the connections between changes in ocean oxygen levels and mass extinction of marine organisms became clear.

The experiments revealed significant global oxygen depletion contemporaneous with the Ireviken event. Compounded with the rising sea level, which brought deoxygenated waters into shallower and more habitable areas, the reduced oxygen conditions were more than enough to play a central role in the mass extinction. This was the first direct evidence of a credible link between expansive oxygen loss and the Ireviken extinction event.

Artists conception of Silurian fishes
File:Silurianfishes ntm 1905 smit 1929.gif
Credit: Joseph Smit  / Wikimedia Commons

But, Young found, that oxygen loss wasn’t universal. Only about 8 percent or less of the global oceans experienced significantly reducing conditions with very little to no oxygen and high levels of toxic sulfide, suggesting that these conditions didn’t need to advance to whole-ocean scale to have an outsized, destructive effect.

“Our study finds that you don’t necessarily need the entire ocean to be reducing to generate these kind of geochemical signatures and to provide a kill mechanism for this significant extinction event,” Young said.

Today, like 430 million years ago, sea level is on the rise and ocean oxygen is hemorrhaging at an alarming rate. As parallels continue to emerge between today’s changes and past calamities, peering into the Earth’s distant past could be a critical tool in preparing for the future.

“There are common threads with other climatic and extinction events throughout Earth’s history, and future work will continue to help us understand the similarities and differences of these events to constrain future climate predictions,” said co-author Jeremy Owens, an assistant professor in FSU’s Department of Earth, Ocean and Atmospheric Science who has worked on other extinction events in the Jurassic and Cretaceous periods.

“I think it’s important to see how these events played out all the way from extinction interval through recovery period, how severe they were and their connections to the ancient environment along the way,” added Young. “That could help us figure out what’s in store for our future and how we can potentially mitigate some of the negative outcomes.”

This study was funded by the National Science Foundation and the Geological Society of America.



Contacts and sources:
Florida State University

Citation:  Geochemical evidence for expansion of marine euxinia during an early Silurian (Llandovery–Wenlock boundary) mass extinction Author links open overlay panelSeth A.YoungAndrewKleinbergJeremy D.Owens https://www.sciencedirect.com/science/article/pii/S0012821X19301207



New Evidence of Deep Groundwater on Mars



Research from the USC Arid Climate and Water Research Center suggests deep groundwater on Mars could still be active and creating surface streams in some near-equatorial areas on the planet.

In mid-2018, researchers supported by the Italian Space Agency detected the presence of a deep-water lake on Mars under its south polar ice caps. Now, the researchers at USC have determined that groundwater likely exists in a broader geographical area than just the poles of Mars and that there is an active system, as deep as 750 meters, from which groundwater comes to the surface through cracks in the specific craters they analyzed.

USC research scientist Essam Heggy, a member of the Mars Express sounding radar experiment MARSIS probing the Mars subsurface, and co-author Abotalib Z. Abotalib, a postdoctoral research associate at USC, studied the characteristics of the planet’s recurring slope linea, which are akin to dried, short streams of water that appear on some crater walls.

A computer-generated image depicts part of Mars at the boundary between darkness and daylight.
Water on Mars: Computer-generated view of the planet
Credit: NASA, JPL-Caltech

Scientists previously thought these features were affiliated with surface water flow or close subsurface water flow, said Heggy, who added that the new research suggests that may not be true.

“We propose an alternative hypothesis that they originate from a deep pressurized groundwater source which comes to the surface moving upward along ground cracks,” he said.
Water on Mars: Similarities here on Earth

Abotalib, the paper’s first author, noted that their research in desert hydrology helped lead to this conclusion.

“We have seen the same mechanisms in the North African Sahara and in the Arabian Peninsula, and it helped us explore the same mechanism on Mars,” he said.

The two scientists concluded that fractures within some of Mars’ craters enabled water springs to rise up to the surface as a result of pressure deep below. These springs leaked onto the surface, generating the sharp and distinct linear features found on the walls of those craters.
Broader area for water on Mars?

The study, published Thursday in Nature Geoscience, suggests that groundwater might be deeper than previously thought in areas where such streams are observed on Mars. The findings suggest that the exposed part of these ground fractures are associated with these springs as the primary location candidates to explore Mars’ habitability. Their work also recommends that new probing methods be developed to study these fractures.

The paper, “A deep groundwater origin for recurring slope linea on Mars,” is the first Mars paper by the newly created water research center at USC. The work is funded under the NASA Planetary Geology and Geophysics Program.




Contacts and sources:
Amy Blumenthal
University of Southern California

Citation: A deep groundwater origin for recurring slope lineae on Mars
Abotalib Z. Abotalib, Essam Heggy.. Nature Geoscience, 2019; 12 (4): 235 DOI: 10.1038/s41561-019-0327-5



Adhesive Formed From Bee Spit and Flower Oil Could Form Basis of New Glues



Honey bees spend hours each day collecting pollen and packing it into tidy bundles attached to their hind legs.

But all of that hard work could instantly be undone during a sudden rainstorm were it not for two substances the insect uses to keep the pollen firmly stuck in place: bee spit and flower oil.

Now researchers at Georgia Institute of Technology are looking at that mixture of ingredients as a model for a bioinspired glue because of its unique adhesive properties and ability to remain sticky through a range of conditions.

Researchers at Georgia Tech are looking at modeling new adhesives based off of how honey bees make pollen stick together.

Credit: Georgia Tech

“A bee encounters not just wet and humid environments but windy and dry surroundings as well, so its pollen pellet must counteract those variations in humidity while remaining adhered,” said J. Carson Meredith, a professor in Georgia Tech’s School of Chemical and Biomolecular Engineering. “Being able to withstand those kinds of changes in humidity is still a challenge for synthetic adhesives.”

In a study published March 26 in the journal Nature Communications and sponsored by the Air Force Office of Scientific Research, the researchers described how those two natural liquids work together to protect the bee’s bounty as it travels back to its hive.

The first component of the glue is the bee’s own salivary secretions, which coat the pollen grains and allow them to stick together. The bees produce those sugary secretions, the main ingredient in honey, from nectar they drink from the flowers.

The second ingredient is a plant-based oil that coats the pollen grains called pollenkitt, which helps stabilize the adhesive properties of the nectar and protect it from the impact of too much or too little humidity.

“It works similarly to a layer of cooking oil covering a pool of syrup,” Meredith said. “The oil separates the syrup from the air and slows down drying considerably.”


Honey bee on campus at Georgia Tech

Credit Yumiko Sakurai


The researchers tested the adhesive properties of the bee’s glue by separating the oil-based component from the sugar-based component and evaluating how sticky the nectar remained under various humidity conditions. As expected, as humidity increased and the nectar absorbed more water, its adhesive properties diminished. The same effect was true when humidity decreased and the nectar dried out. Meanwhile, under similar conditions, nectar coated with the pollenkitt oil remained sticky despite changes in humidity.

“We believe you could take the essential concepts of this material and develop a novel adhesive with a water-barrier external oil layer that could better resist humidity changes in the same way,” Meredith said. “Or potentially this concept would apply to controlling the working time of an adhesive, such as its ability to flow and time to dry or cure.”

The research team, which included Victor Breedveld, an associate professor in the School of Chemical and Biomolecular Engineering, also examined dynamics of the bee adhesive.

“We wanted to know, if the pollen can stay so firmly attached to the bee’s hind legs, how do the bees manage to remove it when they return to the hive,” Meredith said.

The answer may lie in the adhesive’s a rate-sensitive response. In other words, the faster the force attempting to remove it, the more it would resist.

“This is a property of capillary adhesion, which we believe could be harnessed and tailored for specific applications, such as controlling motion in microscopic or nanoscale devices, in fields ranging from construction to medicine,” Meredith said.

This work was supported by the Air Force Office of Scientific Research under grant No. FA9550-10-1-0555. Any conclusions or recommendations are those of the authors and do not necessarily represent the official views of the sponsoring organizations.






Contacts and sources:
Josh Brown
Georgia Institute of Technology


Citation:Donglee Shin, Won Tae Choi, Haisheng Lin, Zihao Qu, Victor Breedveld, and J. Carson Meredith, “Humidity-tolerant rate-dependent capillary viscous adhesion of bee-collected pollen fluids,” (Nature Communications, March 2019). https://doi.org/10.1038/s41467-019-09372-x



No One Is Quite Sure What It Is Made Of



Researchers from Russia, Finland, and the U.S. have put a constraint on the theoretical model of dark matter particles by analyzing data from astronomical observations of active galactic nuclei. The new findings provide an added incentive for research groups around the world trying to crack the mystery of dark matter: No one is quite sure what it is made of. The paper was published in the Journal of Cosmology and Astroparticle Physics.

The question of what particles make up dark matter is a crucial one for modern particle physics. Despite the expectations that dark matter particles would be discovered at the Large Hadron Collider, this did not happen. A number of then-mainstream hypotheses about the nature of dark matter had to be rejected. Diverse observations indicate that dark matter exists, but apparently something other than the particles in the Standard Model constitutes it. Physicists thus have to consider further options that are more complex. The Standard Model needs to be extended. Among the candidates for inclusion are hypothetical particles that may have masses in the range from 10?²? to 10?¹? times the mass of the electron. That is, the heaviest speculated particle has a mass 40 orders of magnitude greater than that of the lightest.

This image of Centaurus A, one of the closest active galaxies to Earth, combines the data from observations in multiple frequency ranges.

Credit: ESO/WFI (optical), MPIfR/ESO/APEX/A. Weiss et al. (submillimeter), NASA/CXC/CfA/R. Kraft et al. (X-ray)


One theoretical model treats dark matter as being made up of ultralight particles. This offers an explanation for numerous astronomical observations. However, such particles would be so light that they would interact very weakly with other matter and light, making them exceedingly hard to study. It is almost impossible to spot a particle of this kind in a lab, so researchers turn to astronomical observations.

"We are talking about dark matter particles that are 28 orders of magnitude lighter than the electron. This notion is critically important for the model that we decided to test. The gravitational interaction is what betrays the presence of dark matter. If we explain all the observed dark matter mass in terms of ultralight particles, that would mean there is a tremendous number of them. But with particles as light as these, the question arises: How do we protect them from acquiring effective mass due to quantum corrections? Calculations show that one possible answer would be that these particles interact weakly with photons -- that is, with electromagnetic radiation. This offers a much easier way to study them: by observing electromagnetic radiation in space," said Sergey Troitsky, a co-author of the paper and chief researcher at the Institute for Nuclear Research of the Russian Academy of Sciences.

When the number of particles is very high, instead of individual particles, you can treat them as a field of certain density permeating the universe. This field coherently oscillates over domains that are on the order of 100 parsecs in size, or about 325 light years. What determines the oscillation period is the mass of the particles. If the model considered by the authors is correct, this period should be about one year. When polarized radiation passes through such a field, the plane of radiation polarization oscillates with the same period. If periodic changes like this do in fact occur, astronomical observations can reveal them. And the length of the period -- one terrestrial year -- is very convenient, because many astronomical objects are observed over several years, which is enough for the changes in polarization to manifest themselves.

The authors of the paper decided to use the data from Earth-based radio telescopes, because they return to the same astronomical objects many times during a cycle of observations. Such telescopes can observe remote active galactic nuclei -- regions of superheated plasma close to the centers of galaxies. These regions emit highly polarized radiation. By observing them, one can track the change in polarization angle over several years.

"At first it seemed that the signals of individual astronomical objects were exhibiting sinusoidal oscillations. But the problem was that the sine period has to be determined by the dark matter particle mass, which means it must be the same for every object. There were 30 objects in our sample. And it may be that some of them oscillated due to their own internal physics, but anyway, the periods were never the same," Troitsky goes on. "This means that the interaction of our ultralight particles with radiation may well be constrained. We are not saying such particles do not exist, but we have demonstrated that they don't interact with photons, putting a constraint on the available models describing the composition of dark matter."

"Just imagine how exciting that was! You spend years studying quasars, when one day theoretical physicists turn up, and the results of our high-precision and high angular resolution polarization measurements are suddenly useful for understanding the nature of dark matter," enthusiastically adds Yuri Kovalev, a co-author of the study and laboratory director at the Moscow Institute of Physics and Technology and Lebedev Physical Institute of the Russian Academy of Sciences.

In the future, the team plans to search for manifestations of hypothesized heavier dark matter particles proposed by other theoretical models. This will require working in different spectral ranges and using other observation techniques. According to Troitsky, the constraints on alternative models are more stringent.

"Right now, the whole world is engaged in the search for dark matter particles. This is one of the great mysteries of particle physics. As of today, no model is accepted as favored, better-developed, or more plausible with regard to the available experimental data. We have to test them all. Inconveniently, dark matter is "dark" in the sense that it hardly interacts with anything, particularly with light. Apparently, in some scenarios it could have a slight effect on light waves passing through. But other scenarios predict no interactions at all between our world and dark matter, other than those mediated by gravity. This would make its particles very hard to find," concludes Troitsky.

The study reported in this story was supported by the Russian Science Foundation, grant No. 18-12-00258.

The research team co-authoring the paper includes scientists from the Institute for Nuclear Research and Lebedev Physical Institute of the Russian Academy of Sciences, the Moscow Institute of Physics and Technology, the Crimean Astrophysical Observatory, Purdue University (U.S.), and Aalto University (Finland).



Contacts and sources:
Varvara Bogomolova
Moscow Institute Of Physics And Technology

Citation:"Constraining the photon coupling of ultra-light dark-matter axion-like particles by polarization variations of parsec-scale jets in active galaxies" by M.M. Ivanov, Y.Y. Kovalev, M.L. Lister, A.G. Panin, A.B. Pushkarev, T. Savolainen, and S.V. Troitsky, published Feb.28, 2019, in Journal of Cosmology and Astroparticle Physics.