The Northwestern University study quantified the differences in air pollution generated from battery-powered electric vehicles versus internal combustion engines. The researchers found that even when their electricity is generated from combustion sources, electric vehicles have a net positive impact on air quality and climate change.

“In contrast to many of the scary climate change impact stories we read in the news, this work is about solutions,” said Northwestern’s Daniel Horton, senior author of the study. “We know that climate change is happening, so what can we do about it? One technologically available solution is to electrify our transportation system. We find that EV adoptions reduces net carbon emissions and has the added benefit of reducing air pollutants, thereby improving public health.”

The research published Friday, April 5 in the journal Atmospheric Environment. Horton is an assistant professor of Earth and planetary sciences in Northwestern’s Weinberg College of Arts and Sciences. Jordan Schnell, a postdoctoral research fellow with the Ubben Program for Climate and Carbon Science in the Institute for Sustainability and Energy at Northwestern, was the paper’s first author.

To quantify the differences between the two types of vehicles, the researchers used an emissions remapping algorithm and air quality model simulations. They used these methods to closely examine two pollutants related to automobiles and power emissions: ozone and particulate matter. Both are main components of smog and can trigger a variety of health problems, such as asthma, emphysema and chronic bronchitis.

To fully account for the complexity of changes to air pollution chemistry, the researchers took multiple variables into consideration:

• Potential electric vehicles adoption rates
• Generation of electric vehicle power supply, including our current combustion-dominant mix, combustion-only sources and enhanced emission-free renewables
• Geographical locations
• Seasons and times of day

Ozone levels decreased across the board in simulations of warmer weather months. In the wintertime, however, ozone levels increase slightly but are already much lower compared to summer due to a chemical reaction that occurs differently during times of lesser winter sunlight.

“Across scenarios, we found the more cars that transitioned to electric power, the better for summertime ozone levels,” Schnell said. “No matter how the power is generated, the more combustion cars you take off the road, the better the ozone quality.”

Particulate matter, which is also called “haze,” decreased in the wintertime but showed greater variation based on location and how the power was generated. Locations with more coal-fired power in their energy mix, for example, experienced an increase in haze during the summer. Locations with clean energy sources, however, saw drastic reductions in human-caused haze.

“We found that in the Midwest, the increased power demands of EV charging in our current energy mix could cause slight increases in summer particulate matter due to the reliance on coal-fired power generation,” Schnell said. “However, if we transition more of the Midwest’s power generation to renewables, particulate matter pollution is substantially reduced. In the Pacific Northwester or Northeast, where there is already more clean power available, EV adoption — even with the current energy mix — will decrease particulate matter pollution.”

The research was supported by the Ubben Program for Carbon and Climate Science and the National Science Foundation (grant number CBET-1848683).

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Researchers report that shallow bodies of water, on the order of 10 centimeters deep, could have held high concentrations of what many scientists believe to be a key ingredient for jump-starting life on Earth: nitrogen.

In shallow ponds, nitrogen, in the form of nitrogenous oxides, would have had a good chance of accumulating enough to react with other compounds and give rise to the first living organisms. In much deeper oceans, nitrogen would have had a harder time establishing a significant, life-catalyzing presence, the researchers say.

“Our overall message is, if you think the origin of life required fixed nitrogen, as many people do, then it’s tough to have the origin of life happen in the ocean,” says lead author Sukrit Ranjan, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “It’s much easier to have that happen in a pond.”

Ranjan and his colleagues have published their results today in the journal Geochemistry, Geophysics, Geosystems. The paper’s co-authors are Andrew Babbin, the Doherty Assistant Professor in Ocean Utilization in EAPS, along with Zoe Todd and Dimitar Sasselov of Harvard University, and Paul Rimmer at Cambridge University.

Breaking a bond

If primitive life indeed sprang from a key reaction involving nitrogen, there are two ways in which scientists believe this could have happened. The first hypothesis involves the deep ocean, where nitrogen, in the form of nitrogenous oxides, could have reacted with carbon dioxide bubbling forth from hydrothermal vents, to form life’s first molecular building blocks.

The second nitrogen-based hypothesis for the origin of life involves RNA — ribonucleic acid, a molecule that today helps encode our genetic information. In its primitive form, RNA was likely a free-floating molecule. When in contact with nitrogenous oxides, some scientists believe, RNA could have been chemically induced to form the first molecular chains of life. This process of RNA formation could have occurred in either the oceans or in shallow lakes and ponds.

Nitrogenous oxides were likely deposited in bodies of water, including oceans and ponds, as remnants of the breakdown of nitrogen in Earth’s atmosphere. Atmospheric nitrogen consists of two nitrogen molecules, linked via a strong triple bond, that can only be broken by an extremely energetic event — namely, lightning.

“Lightning is like a really intense bomb going off,” Ranjan says. “It produces enough energy that it breaks that triple bond in our atmospheric nitrogen gas, to produce nitrogenous oxides that can then rain down into water bodies.”

Scientists believe that there could have been enough lightning crackling through the early atmosphere to produce an abundance of nitrogenous oxides to fuel the origin of life in the ocean. Ranjan says scientists have assumed that this supply of lightning-generated nitrogenous oxides was relatively stable once the compounds entered the oceans.

However, in this new study, he identifies two significant “sinks,” or effects that could have destroyed a significant portion of nitrogenous oxides, particularly in the oceans. He and his colleagues looked through the scientific literature and found that nitrogenous oxides in water can be broken down via interactions with the sun’s ultraviolet light, and also with dissolved iron sloughed off from primitive oceanic rocks.

Ranjan says both ultraviolet light and dissolved iron could have destroyed a significant portion of nitrogenous oxides in the ocean, sending the compounds back into the atmosphere as gaseous nitrogen.

“We showed that if you include these two new sinks that people hadn’t thought about before, that suppresses the concentrations of nitrogenous oxides in the ocean by a factor of 1,000, relative to what people calculated before,” Ranjan says.

“Building a cathedral”

In the ocean, ultraviolet light and dissolved iron would have made nitrogenous oxides far less available for synthesizing living organisms. In shallow ponds, however, life would have had a better chance to take hold. That’s mainly because ponds have much less volume over which compounds can be diluted. As a result, nitrogenous oxides would have built up to much higher concentrations in ponds. Any “sinks,” such as UV light and dissolved iron, would have had less of an effect on the compound’s overall concentrations.

Ranjan says the more shallow the pond, the greater the chance nitrogenous oxides would have had to interact with other molecules, and particularly RNA, to catalyze the first living organisms.

“These ponds could have been from 10 to 100 centimeters deep, with a surface area of tens of square meters or larger,” Ranjan says. “They would have been similar to Don Juan Pond in Antarctica today, which has a summer seasonal depth of about 10 centimeters.”

That may not seem like a significant body of water, but he says that’s precisely the point: In environments any deeper or larger, nitrogenous oxides would simply have been too diluted, precluding any participation in origin-of-life chemistry. Other groups have estimated that, around 3.9 billion years ago, just before the first signs of life appeared on Earth, there may have been about 500 square kilometers of shallow ponds and lakes worldwide.

“That’s utterly tiny, compared to the amount of lake area we have today,” Ranjan says. “However, relative to the amount of surface area prebiotic chemists postulate is required to get life started, it’s quite adequate.”

The debate over whether life originated in ponds versus oceans is not quite resolved, but Ranjan says the new study provides one convincing piece of evidence for the former.

“This discipline is less like knocking over a row of dominos, and more like building a cathedral,” Ranjan says. “There’s no real ‘aha’ moment. It’s more like building up patiently one observation after another, and the picture that’s emerging is that overall, many prebiotic synthesis pathways seem to be chemically easier in ponds than oceans.”

This research was supported, in part, by the Simons Foundation and MIT.

“Everyone thinks you need to ‘practice, practice, practice’ when learning something new. Instead, we found that resting, early and often, may be just as critical to learning as practice,” said Leonardo G. Cohen, M.D., Ph.D., senior investigator at NIH’s National Institute of Neurological Disorders and Stroke and a senior author of the paper published in the journal Current Biology. “Our ultimate hope is that the results of our experiments will help patients recover from the paralyzing effects caused by strokes and other neurological injuries by informing the strategies they use to ‘relearn’ lost skills.”

The study was led by Marlene Bönstrup, M.D., a postdoctoral fellow in Dr. Cohen’s lab. Like many scientists, she held the general belief that our brains needed long periods of rest, such as a good night’s sleep, to strengthen the memories formed while practicing a newly learned skill. But after looking at brain waves recorded from healthy volunteers in learning and memory experiments at the NIH Clinical Center, she started to question the idea.

The waves were recorded from right-handed volunteers with a highly sensitive scanning technique called magnetoencephalography. The subjects sat in a chair facing a computer screen and under a long cone-shaped brain scanning cap. The experiment began when they were shown a series of numbers on a screen and asked to type the numbers as many times as possible with their left hands for 10 seconds; take a 10 second break; and then repeat this trial cycle of alternating practice and rest 35 more times. This strategy is typically used to reduce any complications that could arise from fatigue or other factors.

As expected, the volunteers’ speed at which they correctly typed the numbers improved dramatically during the first few trials and then leveled off around the 11th cycle. When Dr. Bönstrup looked at the volunteers’ brain waves she observed something interesting.

“I noticed that participants’ brain waves seemed to change much more during the rest periods than during the typing sessions,” said Dr. Bönstrup. “This gave me the idea to look much more closely for when learning was actually happening. Was it during practice or rest?”

By reanalyzing the data, she and her colleagues made two key findings. First, they found that the volunteers’ performance improved primarily during the short rests, and not during typing. The improvements made during the rest periods added up to the overall gains the volunteers made that day. Moreover, these gains were much greater than the ones seen after the volunteers returned the next day to try again, suggesting that the early breaks played as critical a role in learning as the practicing itself.

Second, by looking at the brain waves, Dr. Bönstrup found activity patterns that suggested the volunteers’ brains were consolidating, or solidifying, memories during the rest periods. Specifically, they found that the changes in the size of brain waves, called beta rhythms, correlated with the improvements the volunteers made during the rests.

Further analysis suggested that the changes in beta oscillations primarily happened in the right hemispheres of the volunteers’ brains and along neural networks connecting the frontal and parietal lobes that are known to help control the planning of movements. These changes only happened during the breaks and were the only brain wave patterns that correlated with performance.

“Our results suggest that it may be important to optimize the timing and configuration of rest intervals when implementing rehabilitative treatments in stroke patients or when learning to play the piano in normal volunteers,” said Dr. Cohen. “Whether these results apply to other forms of learning and memory formation remains an open question.”

Dr. Cohen’s team plans to explore, in greater detail, the role of these early resting periods in learning and memory.

Containing an incredible half-million stars, this 8-billion-year-old cosmic bauble is one of the largest and brightest globular clusters ever discovered. However, what makes Messier 3 extra special is its unusually large population of variable stars — stars that fluctuate in brightness over time. New variable stars continue to be discovered in this sparkling stellar nest to this day, but so far we know of 274, the highest number found in any globular cluster by far. At least 170 of these are of a special variety called RR Lyrae variables, which pulse with a period directly related to their intrinsic brightness. If astronomers know how bright a star truly is based on its mass and classification, and they know how bright it appears to be from our viewpoint here on Earth, they can thus work out its distance from us. For this reason, RR Lyrae stars are known as standard candles — objects of known luminosity whose distance and position can be used to help us understand more about vast celestial distances and the scale of the cosmos.

Messier 3 also contains a relatively high number of so-called blue stragglers, which are shown quite clearly in this Hubble image. These are blue main sequence stars that appear to be young because they are bluer and more luminous than other stars in the cluster. As all stars in globular clusters are believed to have formed together and thus to be roughly the same age, only a difference in mass can give these stars a different color. A red, old star can appear bluer when it acquires more mass, for instance by stripping it from a nearby star. The extra mass changes it into a bluer star, which makes us think it is younger than it really is.

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Perovskite-based solar cells are the fastest-advancing solar technology to date. Since they were first used in 2009, perovskite solar cells have achieved high efficiencies (over 22% under standard solar irradiation) at low production costs. Although most of the perovskite components are optimized, there’s still room for improvement. Especially in reference to the Hole Transport Materials (HTMs) employed.

The collaboration, among researchers from ICIQ’s Palomares and Vidal groups, the Physical Chemistry of Surfaces and Interfaces group at the Institut de Ciència de Materials de Barcelona (ICMAB-CSIC) and IMDEA Nanocienca, sheds light on the reasons behind the differences observed in perovskite solar cells’ performance by comparing four different HTMs that present close chemical and physical properties.

Little changes can be powerful

Perovskite-based solar cells are approaching the stability — under working conditions — necessary to be trusted as potential commercial products. The major concern is the materials used, particularly spiro-OMeTAD — the most widely used HTM, which is prone to degradation. Therefore, current research is focused on finding alternatives. “Scientists have been designing new molecules that could replace spiro-OMeTAD for years. Looking for molecules with similar electrical and optic characteristics than spiro-OMeTAD and hoping to get similar results. But when testing new HTMs, instead of getting similar results, the cells worked very badly. So, we decided to understand why this happened,” explains Núria F. Montcada, a postdoctoral researcher at the Palomares group and one of the first authors of the paper.

The researchers realized that new molecules with the potential to replace spiro-OMeTAD as HTM were selected on the basis to their properties in solution. However, in functional solar cells, these molecules are prepared in the form of thin films whose surfaces, in turn, are placed in contact with other materials, forming interfaces. The created interfaces may confer changes in the properties of the molecules.

Through the collaboration with ICMAB scientists, the surface work function of each HTM layer on perovskites solar cells was measured to find that “Spiro-OMeTAD energy levels align perfectly with respect to the other components of the cell, while the energetic landscape is less favorable for layers of the new HTM molecules tested. Surfaces and interfaces created in the solar cell stack have a crucial role in the functional device performances,” says Carmen Ocal, researcher at ICMAB. “We have to be aware that the perovskite-HTM interface may shift the energy levels and produce undesired energy misalignments. We’ve come to demonstrate that the study of molecules needs to match the conditions under which the molecule is going to be used — otherwise molecule design is just trial and error,” concludes Montcada.

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A team led by PhD candidate Thimo Ruethers from JCU’s Australian Institute for Tropical Health and Medicine (AITHM) evaluated 26 commercially available fish preparations used for skin prick testing, the most common way of diagnosing fish allergy in Australia.

“We found the amount of allergens present varied greatly, and in some preparations major fish allergens could not be detected. This means many skin prick tests that show a person being tested is not allergic to fish may be wrong,” said Mr Ruethers.

Professor Andreas Lopata from AITHM said the diagnosis of food allergy is fraught with problems.

“There are no regulations requiring the standardisation of commercial preparations for skin prick testing, while improved preparations are pricey and often impossible to get,” he said.

Mr Ruethers said results from skin prick testing need to be questioned as the current preparations appear unreliable in diagnosing fish allergy.

“We urgently need reliable tools to diagnose fish allergy, a serious and often life-threatening immune disease. Current tests can be falsely negative, putting lives at risk,” he said.

Professor Lopata added that seafood is now the number one cause of allergy-related deaths in Australia. He and his team are working on advanced diagnostics and therapy for seafood allergy.

Professor Lopata added that hundreds of different fish species containing different allergens are consumed in Australia, but commercial preparations for allergy testing are available for only four species.

Background:

Fish allergy is one of the most common food allergies worldwide among those that are not outgrown after childhood. Allergic reactions can be life-threatening and there is no cure for the serious, chronic immune disease. People suffering from fish allergy must avoid any food potentially containing fish.

The research team at JCU currently evaluates over 100 Australian fish species for their allergens. A recent discovery was the ‘ray of hope’ for fish allergy sufferers. This found that fish with a cartilaginous skeleton, including ray, are for some patients less allergenic than their fishy counterparts with bony skeletons.

Further investigations are underway, and it’s hoped they will lead to improved diagnostics of fish allergy and safe fish menus for fish allergy sufferers.

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