Their findings were published on August 14th in Scientific Reports.

Upper-level observations such as radiosondes in the Arctic can help to forecast mid-latitude extreme events. Impacts of the Arctic observations can transfer via the tropospheric polar vortex, which is massive low-pressure air mass over the Arctic or Antarctic regions at about 10-km altitude. The tropospheric polar vortex sometimes extends toward mid-latitudes accompanied with meandering of mid-latitude westerly jets. This extension can occur even in summer: in August-September 2016, the meandering and extension were relatively active among the recent years. Thus, the impacts of the Arctic radiosonde observations could influence the mid-latitude extremes, the courses of three tropical cyclones approaching to Japan or Northern U.S. and Greenland, since the impacts transferred trough the extended tropospheric polar vortex.

Having a clearer understanding of these influences can help us better predict, track and prepare for extreme weather events such as cyclones. Currently, meteorological observations are conducted by radiosonde, a weather instrument that records meteorological data, typically released into the atmosphere with a weather balloon. However, due to hostile conditions experienced in the Arctic and the limited reach of the low pressure system, the number and frequency of these observations are limited. Consequently, there are gaps in the data that result in weather forecasts being less accurate than what they could and should be, potentially putting peoples’ lives at risk.

“Extreme weather events have been frequently observed in all seasons all over the world,” said lead-author Kazutoshi Sato, an assistant professor at the Kitami Institute of Technology and previous member of the National Institute of Polar Research (NIPR) in Japan. “Hurricanes and typhoons are one of the most influential phenomena for human life. Precise weather forecast is critical to enable communities to adequately prepare for weather disasters,” he added.

For the study, the researchers performed weather forecast experiments for three tropical cyclones that occurred over the North Atlantic and North Pacific during 2016, to determine whether additional observations could help predict their paths and intensity more accurately. To supplement existing weather data observations, additional observations were conducted using weather balloons released from ship- and land-based weather stations based in the Arctic. The data were analyzed using a data assimilation system developed in Japan Agency for Marine-Earth Science and Technology, which can produce reanalysis datasets by “mixing” (assimilating) observations into global atmospheric conditions: the system was indispensable for the forecast experiments. The additional observations improved the predictability of the cyclones, allowing the scientists to track the paths of the cyclones as well as forecast their intensity more accurately.

“This study demonstrated the usefulness of additional Arctic observations for mid-latitude numerical weather forecasts for tropical cyclones,” said co-author Jun Inoue, an associate professor at NIPR — one of four Research Organization of Information Systems (RIOS) institutes.

Additional radiosonde observations and its evaluation on weather forecasts were conducted privately by scientists, said Inoue, adding that while “this ‘quiet revolution of forecasting’ is, of course, beneficial for end users,” it is difficult to implement sustainable Arctic observations due to the harsh environment in the Arctic. “Now, stakeholders and decision-makers can start to consider the future Arctic observing network to reduce the socio-economical risks associated with extreme weather events,” said Inoue. “Our study contributes to providing such an opportunity.”

“From July to September 2018 additional 3,000 radiosondes have been launched from the Arctic region to reduce the uncertainty of forecasts in the Arctic and beyond as part of the Year of Polar Prediction (YOPP) project,” said Inoue. “Many meteorological centers will evaluate their impact on the atmospheric circulation in the Northern Hemisphere. Understanding the predictability of the atmosphere, ocean, and sea ice will progress with advances in the Arctic observing network and numerical model development,” he said.

With extreme weather events becoming more frequent and more intense due to climate and ocean warming, being able to more accurately predict and track tropical cyclones can help communities be more prepared for potentially devastating storms, which in turn can help save lives.

Other authors of this study are Akira Yamazaki of Japan Agency for Marine-Earth Science and Technology, Joo-Hong Kim of Korea Polar Research Institute, Alexander Makshtas, Vasilli Kustov of Arctic and Antarctic Research Institute, Marion Maturilli and Klaus Dethloff of Alfred Wegener Institute.

“Given the tremendous medical burden imposed by degenerative, neoplastic, post-traumatic, and post-surgical skeletal disorders, we believe that identifying this human skeletal stem cell and elucidating its lineage map will enable the molecular diagnosis and treatment of skeletal diseases,” says senior study author Michael Longaker of Stanford University School of Medicine.

Skeletal tissues such as bone possess exceptional regenerative potential. Bone defects heal readily, and some vertebrates can regenerate entire portions of their limbs. But the regenerative capacities of skeletal tissues in other vertebrates are more restricted. For example, bones in mice and humans can recover from small- to moderate-sized defects, but adult cartilage tissues possess little to no regenerative ability. In addition, both mice and humans display severe age-related degeneration of skeletal tissues over time.

Skeletal dysfunction can lead to a broad spectrum of health conditions ranging from age-related diseases such as osteoporosis and osteoarthritis to non-healing skeletal injury, blood disorders, and even cancer. Despite its significant impact on health and disease, treatment options aimed at improving skeletal function are currently limited. One major hurdle is that stem cell regulation in the human skeletal system remains largely unexplored.

In the new study, Longaker and his collaborators addressed this gap in knowledge by identifying and characterizing human skeletal stem cells and downstream bone and cartilage progeny in a variety of tissues. These self-renewing and multipotent cells were present in both fetal and adult human bone marrow tissues and could be derived from induced pluripotent stem cells (iPSCs). By defining the relationships between human skeletal stem cells and downstream skeletal progenitors, the researchers created a detailed lineage map of stem-cell-mediated formation of skeletal tissues in humans.

Moreover, transcriptomic and epigenetic comparisons with mouse skeletal stem cells revealed evolutionarily conserved pathways regulating the stem-cell-mediated formation of skeletal tissues, as well as divergent molecular pathways that may regulate species-specific differences in bone development and skeletal structure.

“By comparing the molecular and functional differences in specific types of stem cells between different species of vertebrates, it may be possible to uncover convergent and divergent mechanisms that underlie tissue growth and regeneration and apply this understanding towards enhancing health and rejuvenation in humans,” says first author Charles Chan of the Stanford University School of Medicine.

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Scientists now believe that a surprising array of conditions, from appetite disorders and obesity to arthritis and depression, may get their start in the gut. But it hasn’t been clear how messages in this so-called “second brain” spread from our stomachs to our cerebrum. For decades, researchers believed that hormones in the bloodstream were the indirect channel between the gut and the brain.

Recent research suggests the lines of communication behind that “gut feeling” is more direct and speedy than a diffusion of hormones. Using a rabies virus jacked up with green fluorescence, Duke researchers traced a signal as it traveled from the intestines to the brainstem of mice. They were shocked to see the signal cross a single synapse in under 100 milliseconds — that’s faster than the blink of an eye.

“Scientists talk about appetite in terms of minutes to hours. Here we are talking about seconds,” said Diego Bohórquez, Ph.D., senior author of the study and assistant professor of medicine at Duke University School of Medicine. “That has profound implications for our understanding of appetite. Many of the appetite suppressants that have been developed target slow-acting hormones, not fast-acting synapses. And that’s probably why most of them have failed.”

The research appears Sept. 21 in the journal Science.

Your brain takes in information from all five senses — touch, sight, hearing, smell and taste — through electrical signals, which travel along long nerve fibers that lie beneath your skin and muscle like fiber optic cables. These signals move fast, which is why the scent of freshly baked cookies seems to hit you the moment you open a door.

Though the gut is just as important a sensory organ as your eyes and ears — after all, knowing when your stomach is in need of a fill-up is key to survival — scientists thought it delivered its messages by a multi-step, somewhat indirect process. Nutrients in your gut, the thinking went, stimulated the release of hormones, which entered the bloodstream minutes to hours after eating, eventually exerting their effects on the brain.

They were partly right. That tryptophan in your turkey dinner is notorious for its transformation into serotonin, the brain chemical that makes you feel sleepy.

But Bohórquez suspected the brain had a way of perceiving cues from the gut more quickly. He noticed that the sensory cells lining the gut shared many of the same characteristics as their cousins on the tongue and in the nose. In 2015, he published a landmark study in the Journal of Clinical Investigation showing that these gut cells contained nerve endings or synapses, suggesting that they might tap into some kind of neural circuitry.

In this study, Bohórquez and his team set out to map that circuitry. First, postdoctoral fellow Maya Kaelberer pumped a rabies virus carrying a green fluorescent tag into the stomachs of mice. She saw that the virus had labeled the vagus nerve before landing in the brainstem, showing her there was a direct circuit.

Next, Kaelberer recreated the gut-brain neural circuit by growing sensory gut cells of mice in the same dish with vagal neurons. She saw the neurons crawl along the surface of the dish to connect to the gut cells and begin to fire signals. When the research team added sugar to the mix, the firing rate sped up. Kaelberer measured how fast the information from sugar in the gut was communicated and was shocked to find it was on the order of milliseconds.

That finding suggested that a neurotransmitter like glutamate — which is involved in conveying other senses like smell and taste — might act as the messenger. Sure enough, when the researchers blocked the release of glutamate in the sensory gut cells, the messages were silenced.

Bohórquez has data that suggests the structure and function of this circuit will be the same in humans.

“We think these findings are going to be the biological basis of a new sense,” Bohórquez said. “One that serves as the entry point for how the brain knows when the stomach is full of food and calories. It brings legitimacy to idea of the ‘gut feeling’ as a sixth sense.”

In the future, Bohórquez and his team are interested in figuring out how this new sense can discern the type of nutrients and caloric value of the foods we eat.

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Materials provided by Duke University. Original written by Marla Vacek Broadfoot. Note: Content may be edited for style and length.

The strange creature called Dickinsonia, which grew up to 1.4 metres in length and was oval shaped with rib-like segments running along its body, was part of the Ediacara Biota that lived on Earth 20 million years prior to the ‘Cambrian explosion’ of modern animal life.

ANU PhD scholar Ilya Bobrovskiy discovered a Dickinsonia fossil so well preserved in a remote area near the White Sea in the northwest of Russia that the tissue still contained molecules of cholesterol, a type of fat that is the hallmark of animal life.

Lead senior researcher Associate Professor Jochen Brocks said the ‘Cambrian explosion’ was when complex animals and other macroscopic organisms — such as molluscs, worms, arthropods and sponges — began to dominate the fossil record.

“The fossil fat molecules that we’ve found prove that animals were large and abundant 558 million years ago, millions of years earlier than previously thought,” said Associate Professor Jochen Brocks from the ANU Research School of Earth Sciences.

“Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran Biota were: giant single-celled amoeba, lichen, failed experiments of evolution or the earliest animals on Earth. The fossil fat now confirms Dickinsonia as the oldest known animal fossil, solving a decades-old mystery that has been the Holy Grail of palaeontology.”

Mr Bobrovskiy said the team developed a new approach to study Dickinsonia fossils, which hold the key between the old world dominated by bacteria and the world of large animals that emerged 540 million years ago during the ‘Cambrian explosion’.

“The problem that we had to overcome was finding Dickinsonia fossils that retained some organic matter,” said Mr Bobrovskiy from the ANU Research School of Earth Sciences.

“Most rocks containing these fossils such as those from the Ediacara Hills in Australia have endured a lot of heat, a lot of pressure, and then they were weathered after that — these are the rocks that palaeontologists studied for many decades, which explained why they were stuck on the question of Dickinsonia‘s true identity.”

Palaeontologists normally study the structure of fossils, but Mr Bobrovskiy extracted and analysed molecules from inside the Dickinsonia fossil found in ancient rocks in Russia to make the breakthrough discovery.

“I took a helicopter to reach this very remote part of the world — home to bears and mosquitoes — where I could find Dickinsonia fossils with organic matter still intact,” Mr Bobrovskiy said.

“These fossils were located in the middle of cliffs of the White Sea that are 60 to 100 metres high. I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone and repeat this process until I found the fossils I was after.”

Associate Professor Brocks said being able to study molecules from these ancient organisms was a gamechanger.

“When Ilya showed me the results, I just couldn’t believe it,” he said.

“But I also immediately saw the significance.”

ANU led the research in collaboration with scientists from the Russian Academy of Science and the Max Planck Institute for Biogeochemistry and the University of Bremen in Germany.

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Materials provided by Australian National University. Note: Content may be edited for style and length.