But while we’ve been producing ammonia at a large scale since the 1930s, it has been accomplished mainly in hulking chemical plants requiring vast amounts of hydrogen gas from fossil fuels — making ammonia among the most energy-intensive among all large-volume chemicals.

A pair of researchers at Case Western Reserve University — one an expert in electro-chemical synthesis, the other in applications of plasmas — are working on fixing that.

Researchers Julie Renner and Mohan Sankaran have come up with a new way to create ammonia from nitrogen and water at low temperature and low pressure. They’ve done it successfully so far in a laboratory without using hydrogen or the solid metal catalyst necessary in traditional processes.

“Our approach — an electrolytic process with a plasma — is completely new,” said Mohan Sankaran, the Goodrich Professor of Engineering Innovation at the Case School of Engineering.

Plasmas, often referred to as the fourth state of matter (apart from solid, liquid or gas), are ionized clouds of gas, consisting of positive ions and free electrons, which give it the unique ability to activate chemical bonds, including the rather challenging nitrogen molecule, at room temperature.

Renner, a Climo Assistant Professor in the Chemical and Biomolecular Engineering Department, added that because this new process doesn’t need high pressure or high temperature or hydrogen, it makes it scalable — “the ideal kind of technology for a much smaller plant, one with high potential to be powered by renewable energy.”

The results of their two-year collaboration were published this month in the journal Science Advances.

History lesson: The Haber-Bosch process

Virtually all commercial ammonia is made from nitrogen and hydrogen, using an iron catalyst at high temperature and pressure.

German physical chemist Fritz Haber received the Nobel Prize for Chemistry in 1918 for developing this process, which made manufacturing ammonia economically feasible.

But the process became more economically profitable when industrial chemist Carl Bosch (who also won a Nobel Prize in 1931) brought the method into a large-scale system. The process was further propelled by a second innovation: the development of steam methane reforming that made hydrogen more accessible and less expensive.

So, what became known as the Haber-Bosch process became the go-to global method for fixing nitrogen and hydrogen to make ammonia.

But Haber-Bosch was never the only approach to nitrogen fixation, it was just the turn-of-the-century winner.

A new, old method rises

Renner and Sankaran have resurrected an element from a little-known Norwegian method that predated Haber-Bosch (the Birkeland-Eyde process) which reacted nitrogen and oxygen to produce nitrates, another chemical that can be used in agriculture. That process lost out to Haber-Bosch mostly because it required even more energy in the form of electricity, a limited resource in the early 20th century.

“Our approach is similar to electrolytic synthesis of ammonia, which has gained interest as an alternative to Haber-Bosch because it can be integrated with renewable energy,” Sankaran said. “However, like the Birkeland-Eyde process, we use a plasma, which is energy intensive. Electricity is still a barrier, but less so now, and with the increase in renewables, it may not be a barrier at all in the future.

“And perhaps most significantly, our process does not produce hydrogen gas,” he said. “This has been the major bottleneck of other electrolytic approaches to forming ammonia from water (and nitrogen), the undesirable formation of hydrogen.”

The Renner-Sankaran process also does not use a solid metal catalyst that could be one of the reasons ammonia is obtained instead of hydrogen.

“In our system, the ammonia is formed at the interface of a gas plasma and liquid water surface and forms freely in solution,” Sankaran said.

So far, the “table-top batches” of ammonia produced by the duo have been very small and the energy efficiency is still less than Haber-Bosch. But with continued optimization, their discovery and development of a new process could someday lead to smaller, more localized ammonia plants which use green energy.

Research in the Nobel Laureate’s lab

“We were able to show that low, medium and high intensity light synchronizes the circadian clock in the fly’s brain to the 24-hour day,” Charlotte Helfrich-Förster describes the central conclusion of the paper in a nutshell. The professor holds the Chair of Neurobiology and Genetics at the University of Würzburg. Her research focus is on chronobiology which refers to the periodic (cyclic) phenomena in living organisms.

She led the study together with her former PhD student Matthias Schlichting, who presently works in the laboratory of Michael Rosbash, winner of the Nobel Prize in Physiology 2017, at Brandeis University in Waltham, Massachusetts (USA). The team published its results in the current issue of The Journal of Neuroscience.

Daily siesta an hour longer

The experiments showed that high-intensity light visibly affects the activity pattern of fruit flies. The effect was most striking in the “siesta,” which was an hour longer on average but at least 30 minutes. This led to a delayed start of the customary evening peak of activity, causing the flies to set off one to two hours later than usual.

The scientists were also able to pinpoint the culprit responsible for the behavioural change at the molecular level: special photo receptors outside of the retina, known as Hofbauer-Buchner eyelets or short HB eyelets. These microscopically small “extra eyes” — each consists of just four sensory cells — were discovered only 30 years ago by the Würzburg biologists Alois Hofbauer and Erich Buchner.

A useful protection response

“We were able to demonstrate for the first time that the Hofbauer-Buchner eyelets respond to high-intensity light and make the flies extend their afternoon nap,” Helfrich-Förster explains. They achieve this via a multi-stage signalling pathway: The HB eyeletsHB use specific acetylcholine receptors to increase the calcium level in a sub-group of the clock neurons. As a consequence, the neurons release a special neuropeptide in the dorsal part of the fly brain, the “pigment-dispersing factor” (PDF). There PDF mediates the activity of further clock neurons that regulate the length of the siesta and control the start of evening activity.

The scientists believe that the fruit fly’s response to high-intensity light makes sense. “It is an essential mechanism to avoid strong and possibly harmful light in the middle of the day,” the neurobiologist explains. After all, high light intensities frequently occur on hot summer days that can be harmful especially for insects — for one thing because they dehydrate quickly and also because they can be spotted more easily by predators in bright daylight.

Comparable structures in humans

To exclude the possibility that the extended siesta might be caused not by the light intensity but by the associated warm temperatures, the scientists also ran their experiments on a control group of genetically modified flies. The circadian clock of these flies no longer responds to temperature variations, but the flies still exhibit the behavioural change. This backs the assumption that the light intensity is responsible for the longer siesta and the delayed evening activity.

According to the researchers, the results of their study show “surprising parallels between Drosophila and the mammalian system.” Mammals — and humans, too, by the way — have specialised photo receptors that perceive intensive light and forward the signals directly to the circadian clock in a special area of the diencephalon (hypothalamus). It is not known whether their activation causes humans to take a longer afternoon nap, too. But the scientists believe that this is quite possible.

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Biochar is a porous, charcoal-like material produced via pyrolysis, the high-temperature decomposition of biomass. Studies show biochar improves soil water properties and enhances agricultural production by an average of 15 percent. It also reduces nutrient leaching, increases nitrogen available to plants and reduces the release of nitrogenous gases, which can improve local air quality.

A policy study led by Ghasideh Pourhashem, a former postdoctoral fellow at Rice’s Baker Institute for Public Policy and now an assistant professor at North Dakota State, surveys existing government programs and details how they support the use of biochar to enhance agricultural productivity, sequester carbon and preserve valuable soil. The federal government already has 35 programs that do — or could — promote the deployment of biochar to improve agricultural preservation and head off future environmental woes, according to Pourhashem and her team.

For the open-access study in Global Change Biology Bioenergy, Pourhashem worked with Rice mentors Caroline Masiello, a professor of Earth, Environmental and Planetary Sciences, and Kenneth Medlock, the James A. Baker, III, and Susan G. Baker Fellow in Energy and Resource Economics.

“Our previous research has shown that wide-scale application of biochar across the United States’ agricultural soils can save millions of dollars in health costs by improving regional air quality,” said Pourhashem, who joined North Dakota’s Department of Coatings and Polymeric Materials and Center for Sustainable Materials Science in 2017 and is a member of the US Biochar Initiative advisory board.

But despite the accumulating evidence, she said biochar adoption has been slow.

“Our new study shows how policy frameworks can support biochar as a resource-saving, crop-boosting and health care-improving material,” Pourhashem said.

The researchers note the United States has long invested in biofuels like ethanol, and they argue that biochar deserves similar long-term support to improve the nation’s soil and food security strategy.

Masiello, a biogeochemist and expert on biochar, noted the financial disconnect between those who bear the cost of land-management changes and those who benefit.

“There are plenty of farmers who want to do the right thing, but the benefits of biochar don’t accrue entirely on-farm,” she said, citing examples like cleaner water and air. “This paper is about how policy can connect the costs borne by farmers with the benefits to us all.”

The only active loan guarantee program the researchers identified for biochar production is the Department of Agriculture’s Biorefinery, Renewable Chemical and Bio-based Product Manufacturing Assistance Program, which provides up to $250 million per project. But other programs run by the Department of Energy, the Department of Agriculture and initiatives in Iowa, Oregon, Colorado and Minnesota provide nearly $250 million more in grants, matching or production payments and tax credits. The researchers also identified eight programs that offer a total of nearly $30 million in research and development funding that implicitly support biochar.

The researchers determined that government’s emphasis on biochar production is inadequate and tilts heavily toward biofuels. They also noted the need for more upfront investment in large biochar-focused production rather than small-scale facilities. They suggested investment could be encouraged by the development of a broadly accepted set of product standards for biochar.

“The potential long-term impacts of biochar are enormous,” Medlock said. “Much of the recent support for biochar has focused on its use for carbon dioxide sequestration, but the benefits are much broader. The potential effects on local air quality and water quality have implications that extend far beyond the application site, which makes policy supportive of investment in biochar production and market development something that should be seriously considered.”

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The risk of extinction varies from species to species depending on how individuals in its populations reproduce and how long each animal survives. Understanding the dynamics of survival and reproduction can support management actions to improve a specie’s chances of surviving.

Mathematical and statistical models have become powerful tools to help explain these dynamics. However, the quality of the information we use to construct such models is crucial to improve our chances of accurately predicting the fate of populations in nature.

“A model that over-simplifies survival and reproduction can give the illusion that a population is thriving when in reality it will go extinct.,” says associate professor Fernando Colchero, author of new paper published in Ecology Letters.

Colchero’s research focuses on mathematically recreating the population dynamics by better understanding the species’s demography. He works on constructing and exploring stochastic population models that predict how a certain population (for example an endangered species) will change over time.

These models include mathematical factors to describe how the species’ environment, survival rates and reproduction determine to the population’s size and growth. For practical reasons some assumptions are necessary.

Two commonly accepted assumptions are that survival and reproduction are constant with age, and that high survival in the species goes hand in hand with reproduction across all age groups within a species. Colchero challenged these assumptions by accounting for age-specific survival and reproduction, and for trade-offs between survival and reproduction. This is, that sometimes conditions that favor survival will be unfavorable for reproduction, and vice versa.

For his work Colchero used statistics, mathematical derivations, and computer simulations with data from wild populations of 24 species of vertebrates. The outcome was a significantly improved model that had more accurate predictions for a species’ population growth.

Despite the technical nature of Fernando’s work, this type of model can have very practical implications as they provide qualified explanations for the underlying reasons for the extinction. This can be used to take management actions and may help prevent extinction of endangered species.

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Now, using one of the most powerful microscopes in the world, scientists from Sanford Burnham Prebys Medical Discovery Institute (SBP) and University of North Carolina at Chapel Hill (UNC-Chapel Hill) have identified a dense, dynamic and disorganized actin filament nanoscaffold — resembling a haystack — that is induced in response to a molecular signal. This is the first time researchers have directly visualized, at the molecular level, a structure that is triggered in response to a cellular signal — a key finding that expands our understanding of how cells move. The study was published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).

“Cyro-electron microscopy is revolutionizing our understanding of the inner workings of cells,” says Dorit Hanein, Ph.D., senior author of the paper and professor in the Bioinformatics and Structural Biology Program at SBP. “This technology allowed us to collect robust, 3D images of regions of cells — similar to MRI, which creates detailed images of our body. We were able to visualize cells in their natural state, which revealed a never-before-seen actin nano-architecture within the cell.”

In the study, the scientists used SBP’s cryo-electron microscope (Titan Krios), artificial intelligence (AI) and tailor-made computational and cell imaging approaches to compare nanoscale images of mouse fibroblasts to time-stamped light images of fluorescent Rac1, a protein that regulates cell movement, response to force or strain (mechanosensing) and pathogen invasion. This technically complex workflow — which bridged five orders of magnitude in scale (tens of microns to nanometers) — took years to develop to its current level of robustness and accuracy and was made possible through experimental and computational efforts of the structural biologist teams at SBP and the biosensors team at UNC-Chapel Hill.

The images revealed a densely packed, disorganized, scaffold-like structure comprised of short actin rods. These structures sprang into view in defined regions where Rac1 was activated, and quickly dissipated when Rac1 signaling stopped — in as little as two and a half minutes. This dynamic scaffold contrasted sharply with various other actin assemblies in areas of low Rac1 activation — some comprised of long, aligned rods of actin, and others comprised of short actin rods branching from the sides of longer actin filaments. The volume encasing the actin scaffold was devoid of common cellular structures, such as ribosomes, microtubules, vesicles and more, likely due to the structure’s intense density.

“We were surprised that experiment after experiment revealed these unique hotspots of unaligned, densely packed actin rods in regions that correlated with Rac1 activation,” says Niels Volkmann, Ph.D., a co-corresponding author of the paper who led the computational part of the study, and professor in the Bioinformatics and Structural Biology Program at SBP. “We believe this disorder is actually the scaffold’s strength — it grants the flexibility and versatility to build larger, complex actin filament architectures in response to additional local spatial cues.”

Next, the scientists would like to expand the protocol to visualize more structures that are created in response to other molecular signals and to further develop the technology to allow access to other regions of the cell.

“This study is only the beginning. Now that we developed this quantitative nanoscale workflow that correlates dynamic signaling behavior with the nano-scale resolution of electron cryo-tomography, we and additional scientists can implement this powerful analytical tool not only for deciphering the inner workings of cell movement but also for elucidating the dynamics of many other macromolecular machines in an unperturbed cellular environment,” says Hanein.

She adds, “Actin is a building-block protein; it interacts with more than 150 actin binding proteins to generate diverse structures, each serving a unique function. We have a surplus of different signals that we would like to map, which could yield even more insights into how cells move.”

Recent research shows that spending time in nature may bring many health benefits, and many environmental programmes around the world are trying to decrease ‘nature-deficit’ and ‘child-nature disconnectedness’ in order to improve children’s health. For example, the WHO, in order to monitor implementation of the Parma Declaration commitment to providing every child with access to “green spaces to play and undertake physical activity,” has set a 300-meter target. Interestingly, 90 per cent of the Hong Kong population lives within 400 metres of such areas. However, despite the extensive, adjacent greenness, families are not using these areas.

“We noticed a tendency where parents are avoiding nature. They perceive it as dirty and dangerous, and their children unfortunately pick up these attitudes. In addition, the green areas are often unwelcoming with signs like “Keep off the grass,” said Dr Tanja Sobko from the School of Biological Sciences of the University of Hong Kong. Until now, it has not been possible to measure connectedness to nature in preschool children, mostly due to the fact that they are too young to answer for themselves.

A new 16-item parent questionnaire (CNI-PPC) to measure “connectedness to nature’ in very young children has been developed by Dr Sobko and her collaborator Prof Gavin Brown, Director of the Quantitative Data Analysis and Research Unit at the University of Auckland. The questionnaire identified four areas that reflect the child-nature relationship: enjoyment of nature, empathy for nature, responsibility towards nature, and awareness of nature.

The study consisted of two parts: the initial interviews with the families and the subsequent development of the questionnaire. Altogether, 493 families with children aged between 2 and 5 have participated in the study. Finally the new questionnaire was tested against the Strengths and Difficulties Questionnaire, a well-established measurement of psychological well-being and children’s behaviour problems. The results revealed that parents who saw their child had a closer connection with nature had less distress, less hyperactivity, & fewer behavioural and emotional difficulties, and improved pro-social behaviour. Interestingly, children who took greater responsibility towards the nature had fewer peer difficulties. The results give a new possibility for investigating the link between the outdoor environment and well-being in pre-school children.

The study is part of Dr Sobko’s research-based programme Play&Grow, which is the first in Hong Kong to promote healthy eating and active playtime with preschool children by connecting them to nature. Launched 2016, it has so far included almost 1000 families from all over Hong Kong.

The findings have been published in multidisciplinary Open Access journal, PLOS ONE. The new scale has already attracted international attention and is being adopted by universities worldwide including Western Australia and Deakin Universities. In addition, the HKU-developed ‘Play&Grow’ programme is also on track to be conducted in Australia.

The next step is to further fine-tune future health promotion/disease prevention interventions, which Dr Sobko and the team are committed to. “We are grateful for the recognition of the Government, which has recently granted significant financial support to this important project,” said Dr Sobko. The new exciting extension of this work is to test the effect of the exposing children to nature and changes in their gut microbiota.

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The decades-long search for these light sensors led to a first success in 2002: Georg Nagel, at the time at Max-Planck-Institute of Biophysics in Frankfurt/M, and collaborators discovered and characterized two so-called channelrhodopsins in algae. These ion channels absorb light, then open up and transport ions. They were named after the visual pigments of humans and animals, the rhodopsins.

Now a third “eye” in algae is known: Researchers discovered a new light sensor with unexpected properties. The research groups of Professor Armin Hallmann (Bielefeld University) and Professor Georg Nagel (Julius-Maximilians-Universität Würzburg, JMU) report this finding in the journal BMC Biology.

Light reduces cGMP production

The surprise: The new photoreceptor is not activated by light but inhibited. It is a guanylyl cyclase which is an enzyme that synthesizes the important messenger cGMP. When exposed to light, cGMP production is severely reduced, leading to a reduced cGMP concentration — and that’s exactly what happens in the human eye as soon as the rhodopsins there absorb light.

The newly discovered sensor is regulated by light and by the molecule ATP. Such “two component systems” are already well known in bacteria, but not in higher evolved cells. The researchers have named the new photoreceptor “Two Component Cyclase Opsin,” 2c-cyclop for short. They found it in two green algae, in the unicellular Chlamydomonas reinhardtii as well as in the multicellular Volvox carteri.

Function shown in oocytes and algae

“For many years there has been genetic data from which we could conclude that in green algae there must be many more rhodopsins than the two previously characterized,” explains Georg Nagel. Only in Chlamydomonas reinhardtii twelve protein sequences are assigned to the opsins, which are the precursors of rhodopsins.

“So far, nobody could demonstrate the function of these light sensors,” says Nagels co-researcher Dr. Shiqiang Gao. Only the research groups from Bielefeld and Würzburg have succeeded in doing so: They have installed the new rhodopsin in oocytes of the toad Xenopus laevis and in the spherical alga Volvox carteri. In both cases, its function could be shown and characterized.

Perspectives for Optogenetics

The authors believe that the 2c-Cyclop light sensor offers new opportunities for optogenetics. With this methodology, the activity of living tissues and organisms can be influenced by light signals. By means of optogenetics, many basic biological processes in cells have already been elucidated. For example, it provided new insights into the mechanisms of Parkinson’s disease and other neurological diseases. She also brought new insights into diseases like autism, schizophrenia, and depression or anxiety disorders.

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