This breakthrough has been led by Professor Kyoung Jin Choi and his research team in the Department of Materials Science and Engineering at UNIST, in collaboration with Professor Jung-Kun Lee and his research team from the University of Pittsburgh in the United States.

In the work, the research team systematically demonstrated that a combination of silicon dioxide (SiO2) nanoparticles and large phosphor particles can convert ultraviolet (UV) to visible light and increase total transmittance of ARC film. Their experimental and computational results also show that SiO2 nanoparticles in the ARC film decrease the reflectance by increasing the diffuse transmittance.

Moreover, the PCE of the device with the ARC film was sustained for 120 hours, maintaining 91% of its initial value, while the PCE of existing devices dropped to 90% of its initial efficiency after 5 hours, and then decreased to 50% after 20 hours. In addition, the initial efficiency of the solar cell has also increased by nearly 4.5% compared to the previous one.

“This optically engineered ARC film successfully promotes the light absorption of the perovskite/silicon tandem solar cell, leading to the improvement of power conversion efficiency of the tandem cell from 22.48% to 23.50%,” noted the research team.

This study has been jointly participated by Seongha Lee (Department of Mechanical Engineering and Material Science, University of Pittsburgh) and Chan Ul Kim (Department of Materials Science and Engineering, UNIST).

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Materials provided by Ulsan National Institute of Science and Technology(UNIST). Original written by JooHyeon Heo. Note: Content may be edited for style and length.

The study’s findings indicate that the steppe, semi-arid and desert zones of Central Asia were once favorable environments for hominins and their dispersal into Eurasia.

An interdisciplinary team of scholars from institutions that span four continents set out to expand the limited knowledge of early hominin activity in the Central Asian lowlands. The team included Dr. Paul Breeze and Professor Nick Drake from Kings College London, Professor Sebastian Breitenbach from Northumbria University Newcastle, Professor Farhod Maksudov from the Uzbekistan Academy of the Sciences, and Professor Michael Petraglia from Griffith University in Queensland, Australia.

“Central Asia connects several zones that played important roles in hominin dispersals out of Africa and through Asia” Dr. Finestone said. “Yet we know comparatively little about the early occupation of Central Asia. Most of the archaeological material is not dated and detailed paleoclimate records are scarce, making it difficult to understand early hominin dispersal and occupation dynamics in that region.”

The team compiled and analyzed paleoclimatic and archaeological data from Pleistocene (ca. 2.58 million years ago to 11,700 years ago) Central Asia. This included building a dataset of Paleolithic stone tools and analyzing a mineral deposit that formed in a cave (a stalagmite) in southern Uzbekistan. Tool-making and tool modification are key to human ability to migrate to new environments and to overcome environmental challenges. Ancient hominins moved their tools with them as they dispersed. The researchers studied the location of stone tools and the environmental conditions that were reflected in the stalagmite as it grew at the end of the Marine Isotope Stage 11 (a warm period between glacials MIS 12 and MIS 10) around 400,000 years ago.

Dr. Maksudov from the Uzbekistan Academy of the Sciences said relatively little is known about the region’s earliest toolmakers because the majority of Lower Paleolithic (the earliest subdivision of Paleolithic stone tools) occurrences in Central Asia lack reliable context for dating and environmental reconstruction.

“Despite the potential importance of Central Asia to early dispersals, our knowledge of the Lower Paleolithic across this vast and diverse landscape has been limited.”

“We compiled data on Paleolithic findings from across Central Asia, creating a dataset of 132 Paleolithic sites — the largest dataset of its kind” said Professor Petraglia, a senior author on the study. “This allowed us to consider the distribution of these sites in the context of a new high-resolution speleothem-based multi-proxy record of hydrological changes in southern Uzbekistan from the Middle Pleistocene.”

“Cave deposits are incredible archives of environmental conditions at the time of their growth. Using geochemical data from stalagmites we gain insights into seasonal to millennial-scale changes in moisture availability and the climatic dynamics that governed rain- and snowfall. Our work suggests that the local and regional conditions did not follow simple long-term trends but were quite variable.” said Professor Breitenbach, who lead the stalagmite-based analysis.

“We argue that Central Asia was a favorable habitat for Paleolithic toolmakers when warm interglacial phases coincided with periods when the Caspian Sea was experiencing consistently high water levels, resulting in greater moisture availability and more temperate conditions in otherwise arid regions” said Dr. Finestone. “The patterning of stone tool assemblages also supports this.”

During periodic warmer and wetter intervals, the local environment of arid Central Asia could have been a favorable habitat and was frequented by Lower Paleolithic toolmakers producing bifaces (stone tools that have been worked on both sides).

“Interdisciplinary work that bridges archaeology with paleoclimate models are becoming increasingly necessary for understanding human origins” said Dr. Finestone. “In the future, the databases generated in this study will continue to allow us to ask questions about the context of hominin dispersals.”

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Materials provided by Cleveland Museum of Natural History. Note: Content may be edited for style and length.

The connection between eating time, sleep and obesity is well-known but poorly understood, with research showing that over-nutrition can disrupt circadian rhythms and change fat tissue.

New Northwestern research has shown for the first time that energy release may be the molecular mechanism through which our internal clocks control energy balance. From this understanding, the scientists also found that daytime is the ideal time in the light environment of the Earth’s rotation when it is most optimal to dissipate energy as heat. These findings have broad implications from dieting to sleep loss and the way we feed patients who require long-term nutritional assistance.

The paper, “Time-restricted feeding mitigates obesity through adipocyte thermogenesis,” will be published online today, and in print tomorrow (Oct. 21) in the journal Science.

“It is well known, albeit poorly understood, that insults to the body clock are going to be insults to metabolism,” said corresponding study author Dr. Joseph T. Bass, the Charles F. Kettering Professor of Medicine at Northwestern University Feinberg School of Medicine. He also is a Northwestern Medicine endocrinologist.

“When animals consume Western style cafeteria diets — high fat, high carb — the clock gets scrambled,” Bass said. “The clock is sensitive to the time people eat, especially in fat tissue, and that sensitivity is thrown off by high-fat diets. We still don’t understand why that is, but what we do know is that as animals become obese, they start to eat more when they should be asleep. This research shows why that matters.”

Bass is also director of the Center for Diabetes and Metabolism and the chief of endocrinology in the department of medicine at Feinberg. Chelsea Hepler, a postdoctoral fellow in the Bass Lab, was the first author and did many of the biochemistry and genetics experiments that grounded the team’s hypothesis. Rana Gupta, now at Duke University, was also a key collaborator.

Scrambling the internal clock

In the study, mice, who are nocturnal, were fed a high-fat diet either exclusively during their inactive (light) period or during their active (dark) period. Within a week, mice fed during light hours gained more weight compared to those fed in the dark. The team also set the temperature to 30 degrees, where mice expend the least energy, to mitigate the effects of temperature on their findings.

“We thought maybe there’s a component of energy balance where mice are expending more energy eating at specific times,” Hepler said. “That’s why they can eat the same amount of food at different times of the day and be healthier when they eat during active periods versus when they should be sleeping.”

The increase in energy expenditure led the team to look into metabolism of fat tissue to see if the same effect occurred within the endocrine organ. They found that it did, and mice with genetically enhanced thermogenesis — or heat release through fat cells — prevented weight gain and improved health.

Hepler also identified futile creatine cycling, in which creatine (a molecule that helps maintain energy) undergoes storage and release of chemical energy, within fat tissues, implying creatine may be the mechanism underlying heat release.

Intermittent fasting and gastric feeding tubes

The science is underpinned by research done by Bass and colleagues at Northwestern more than 20 years ago that found a relationship between the internal molecular clock and body weight, obesity and metabolism in animals.

The challenge for Bass’s lab, which focuses on using genetic approaches to study physiology, has been figuring out what it all means, and finding the control mechanisms that produce the relationship. This study brings them a step closer.

The findings could inform chronic care, Bass said, especially in cases where patients have gastric feeding tubes. Patients are commonly fed at night while they sleep, when they’re releasing the least amount of energy. Rates of diabetes and obesity tend to be high for these patients, and Bass thinks this could explain why. He also wonders how the research could impact Type II Diabetes treatment. Should meal times be considered when insulin is given, for example?

Hepler will continue to research creatine metabolism. “We need to figure out how, mechanistically, the circadian clock controls creatine metabolism so that we can figure out how to boost it,” she said. “Clocks are doing a lot to metabolic health at the level of fat tissue, and we don’t know how much yet.”

Research support was provided by the National Institutes of Health National Institute of Diabetes and Digestive and Kidney Diseases (grants R01DK127800, R01DK113011, R01DK090625, F32DK122675, F30DK116481, F31DK130589, K99DK124682, R01DK104789 and R01DK119163), the National Institute on Aging (grants R01AG065988 and P01AG011412) and the American Heart Association Career Development Award (19CDA34670007).

Most of today’s robotic grippers rely on embedded sensors, complex feedback loops, or advanced machine learning algorithms, combined with the skill of the operator, to grasp fragile or irregularly shaped objects. But researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have demonstrated an easier way.

Taking inspiration from nature, they designed a new type of soft, robotic gripper that uses a collection of thin tentacles to entangle and ensnare objects, similar to how jellyfish collect stunned prey. Alone, individual tentacles, or filaments, are weak. But together, the collection of filaments can grasp and securely hold heavy and oddly shaped objects. The gripper relies on simple inflation to wrap around objects and doesn’t require sensing, planning, or feedback control.

The research was published in the Proceedings of the National Academy of Sciences (PNAS).

“With this research, we wanted to reimagine how we interact with objects,” said Kaitlyn Becker, former graduate student and postdoctoral fellow at SEAS and first author of the paper. “By taking advantage of the natural compliance of soft robotics and enhancing it with a compliant structure, we designed a gripper that is greater than the sum of its parts and a grasping strategy that can adapt to a range of complex objects with minimal planning and perception.”

Becker is currently an Assistant Professor of Mechanical Engineering at MIT.

The gripper’s strength and adaptability come from its ability to entangle itself with the object it is attempting to grasp. The foot-long filaments are hollow, rubber tubes. One side of the tube has thicker rubber than the other, so when the tube is pressurized, it curls like a pigtail or like straightened hair on a rainy day.

The curls knot and entangle with each other and the object, with each entanglement increasing the strength of the hold. While the collective hold is strong, each contact is individually weak and won’t damage even the most fragile object. To release the object, the filaments are simply depressurized.

The researchers used simulations and experiments to test the efficacy of the gripper, picking up a range of objects, including various houseplants and toys. The gripper could be used in real-world applications to grasp soft fruits and vegetables for agricultural production and distribution, delicate tissue in medical settings, even irregularly shaped objects in warehouses, such as glassware.

This new approach to grasping combines Professor L. Mahadevan’s research on the topological mechanics of entangled filaments with Professor Robert Wood’s research on soft robotic grippers.

“Entanglement enables each highly compliant filament to conform locally with a target object leading to a secure but gentle topological grasp that is relatively independent of the details of the nature of the contact,” said Mahadevan, the Lola England de Valpine Professor of Applied Mathematics in SEAS, and of Organismic and Evolutionary Biology, and Physics in FAS and co-corresponding author of the paper.

“This new approach to robotic grasping complements existing solutions by replacing simple, traditional grippers that require complex control strategies with extremely compliant, and morphologically complex filaments that can operate with very simple control,” said Wood, the Harry Lewis and Marlyn McGrath Professor of Engineering and Applied Sciences and co-corresponding author of the paper. “This approach expands the range of what’s possible to pick up with robotic grippers.”

The research was co-authored by Clark Teeple, Nicholas Charles, Yeonsu Jung, Daniel Baum and James C. Weaver. It was supported in part by the Office of Naval Research, under grant N00014-17-1- 206 and the National Science Foundation under grants EFRI-1830901, DMR-1922321, DMR-2011754, DBI-1556164, and EFMA-1830901 and the Simons Foundation, and the Henri Seydoux Fund.

The study, “Deep cis-regulatory homology of the butterfly wing pattern ground plan,” published as the cover story in the Oct. 21 issue of Science, explains how DNA that sits between genes — called ‘junk’ DNA or non-coding regulatory DNA — accommodates a basic plan conserved over tens to hundreds of millions of years while at the same time allowing wing patterns to evolve extremely quickly.

The research supports the idea that an ancient color pattern ground plan is already encoded in the genome and that non-coding regulatory DNA works like switches to turn up some patterns and turn down others.

“We are interested to know how the same gene can build these very different looking butterflies,” said Anyi Mazo-Vargas, Ph.D. ’20, the study’s first author and a former graduate student in the lab of senior author, Robert Reed, professor of ecology and evolutionary biology in the College of Agriculture and Life Sciences. Mazo-Vargas is currently a postdoctoral researcher at George Washington University.

“We see that there’s a very conserved group of switches [non-coding DNA] that are working in different positions and are activated and driving the gene,” Mazo-Vargas said.

Previous work in Reed’s lab has uncovered key color pattern genes: one (WntA) that controls stripes and another (Optix) that controls color and iridescence in butterfly wings. When the researchers disabled the Optix gene, the wings appeared black, and when the WntA gene was deleted, stripe patterns disappeared.

This study focused on the effect of non-coding DNA on the WntA gene. Specifically, the researchers ran experiments on 46 of these non-coding elements in five species of nymphalid butterflies, which is the largest family of butterflies.

In order for these non-coding regulatory elements to control genes, tightly wound coils of DNA become unspooled, a sign that a regulatory element is interacting with a gene to activate it, or in some cases, turn it off.

In the study, the researchers used a technology called ATAC-seq to identify regions in the genome where this unraveling is occurring. Mazo-Vargas compared ATAC-seq profiles from the wings of five butterfly species, in order to identify genetic regions involved in wing pattern development. They were surprised to find that a large number of regulatory regions were shared across very different butterfly species.

Mazo-Vargas and colleagues then employed CRISPR-Cas gene editing technology to disable 46 regulatory elements one at a time, in order to see the effects on wing patterns when each of these non-coding DNA sequences were broken. When deleted, each non-coding element changed an aspect of the wing patterns of the butterflies.

The researchers found that across four of the species — Junonia coenia (buckeye), Vanessa cardui (painted lady), Heliconius himera and Agraulis vanillae (gulf fritillary) — each of these non-coding elements had similar functions with respect to the WntA gene, proving they were ancient and conserved, likely originating in a distant common ancestor.

They also found that D. plexippus (monarch) used different regulatory elements from the other four species to control its WntA gene, perhaps because it lost some of its genetic information over its history and had to reinvent its own regulatory system to develop its unique color patterns.

“We have progressively come to understand that most evolution occurs because of mutations in these non-coding regions,” Reed said. “What I hope is that this paper will be a case study that shows how people can use this combination of ATAC-seq and CRISPR to begin to interrogate these interesting regions in their own study systems, whether they work on birds or flies or worms.”

The study was funded by the National Science Foundation (NSF).

“This research is a breakthrough for our understanding of the genetic control of complex traits, and not only in butterflies,” said Theodore Morgan, a program director at the NSF. “Not only did the study show how the instructions for butterfly color patterns are deeply conserved across evolutionary history, but it also revealed new evidence for how regulatory DNA segments positively and negatively influence traits such as color and shape.”

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Materials provided by Cornell University. Original written by Krishna Ramanujan, courtesy of the Cornell Chronicle. Note: Content may be edited for style and length.

Circadian rhythms, sometimes called the “biological clock,” is the cellular process that rules sleep-wake cycles. The World Health Organization has proclaimed that disrupted circadian rhythms are a probable carcinogen.

The latest research, published in the high-impact journal Science Advances, describes that when the circadian clock gets off track it implicates a cancer-signature gene known as HSF1 that can trigger lung tumors. Lungs are under tight circadian control and seem to be particularly vulnerable to a disrupted biological clock.

The paper describes in mouse models the role of HSF1 signaling, a previously unknown mechanism that may explain tumor formation in response to rhythm disruption.

The findings also suggest that it may be possible to target HSF1 with drug therapy, to prevent cancer among people with frequently disturbed circadian rhythms.

Although this study was done in mice, other data link circadian disruption to human tumors, said co-author Brian Altman, Ph.D., an assistant professor of Biomedical Genetics at the University of Rochester Medical Center and a Wilmot faculty member.

“Everything points in the same direction,” he said. He noted that in this case, when the circadian clocks in mice are disrupted by inconsistent sleep, for example, the outcomes are highly relevant to people who work night shifts or rotating schedules.

Altman’s chief contribution to the study was to provide expertise on a scientific method to assess how the circadian clock behaves in tissues. The Scripps team reached out to Altman to collaborate after seeing a presentation he gave at a scientific meeting on use of the technique, which was invented in 2018 at Vanderbilt University by Jacob Hughey, Ph.D. Altman and his lab have been focused on circadian rhythms and the connection to cancer for several years.

Lead author of the study is Katja Lamia, Ph.D., associate professor of Molecular Medicine at Scripps. The Scripps news release is here. Funding was provided by the National Science Foundation and the National Institutes of Health.

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Materials provided by University of Rochester Medical Center. Original written by Leslie Orr. Note: Content may be edited for style and length.

Researchers scoured paleontological records to compare the historic distribution of Asia’s 14 largest species with their populations in present-day tropical forests.

PhD candidate Zachary Amir, from UQ’s School of Biological Sciences and the Ecological Cascades Lab, said four species — tigers, Asian elephants, wild boars and clouded leopards — showed increased populations in areas with human infrastructure.

“These results show that, under the right conditions, some large animals can live nearby humans and avoid extinction,” Mr Amir said.

“These results challenge the narrative within some conservation circles that humans and megafauna are incompatible.

“Globally there is a trend towards ‘trophic downgrading’, a term referring to the disproportionate loss of the world’s largest animals.

“Trophic downgrading is usually worst near humans because hunters target larger species.

“But in the case of tigers, elephants, wild boars and clouded leopards, their Asian populations are higher nearby humans.

“This may be the outcome of tougher anti-poaching efforts in the national parks that are closer to human settlements and are more frequently visited by tourists.”

The study also found deforestation was still impacting species, and clouded leopard numbers in particular experienced a strong decline in those areas.

But, Mr Amir said the research showed that if the large animal species were not hunted, they could live in relatively small habitats and near humans.

“Previously, there have only been a few examples of large Asian species thriving in small habitats near humans, notably in Mumbai, India where leopards in an urban park prey on stray dogs,” Mr Amir said referring to a prior UQ study.

“Thankfully, we found that a wider range of animals can coexist with humans.”

At one of their study sites in Singapore, where poaching has been eliminated and there are considerable forest restoration efforts, two large animal species are thriving again.

“Singapore has actually experienced the natural re-wilding of sambar deer and wild boars, which are now frequently observed in an urban forest, the Bukit Timah Nature Reserve,” Mr Amir said.

“If we replicate those protection efforts in larger forests and other counties, we may see positive impacts right around the world.

“But before this can happen, humans need to get our act together and limit poaching.”

While there are some positive results, UQ’s Dr Matthew Luskin said the study also noted strong declines in tapirs, Sumatran rhinoceros, sun bears, guar and other large animals.

“The key innovation of this work was to systematically investigate the population trends of many different wildlife species across the region,” Dr Luskin said.

“Then we tested if all species showed consistent trends and if similar parks retained similar species.

“Remarkably, we found no two forests currently possess the same group of wildlife compared to thousands of years ago.”

Dr Luskin said the research offered an opportunity to shape the future of nature.

“These results provide hope for wildlife in forests previously considered too far degraded or too close to cities,” he said.

“Now we’re exploring new conservation strategies for these surprising places.”