After the Deepwater Horizon oil rig spilled more than 170 million gallons of oil into the Gulf of Mexico, nearly two million gallons of Corexit® 9500 was deployed into the Gulf to break the oil down.

“There’s an unfortunate trade-off to using dispersants like this,” said Lindsay Jasperse, a member of the university’s research team that published the study. “They may prevent giant oil spills from washing ashore and damaging wetlands, but they also cause negative effects for species below the ocean’s surface that might have been spared if dispersants weren’t used.”

Oysters are considered a keystone species due their value to their ecosystem. Primarily, they serve as water purifiers, filtering out particles and nutrients from the water to improve the quality for surrounding species. Oyster reefs also prevent erosion and provide habitat and protection for many crabs and fish. Unfortunately, as they are immobile and so abundant, they are at a significant risk for critical exposure to oil and oil dispersants following environmental disasters.

Researchers compared, in a controlled environment, the toxicity of oil alone, the dispersant alone and a mixture of the two on oysters. The researchers tested both the oysters’ feeding rates, or how well they could filter algae, and immune functions, or how well they could absorb and destroy bacteria, which indicates an oyster’s ability to fight off infection. A reduction in an oyster’s feeding rates could result in stunted growth or even death. If an oyster’s immune system is compromised, it can be more likely to succumb to infection.

For the oysters’ immune function, the dispersant alone was the most toxic, followed by the dispersant and oil mixture. Oil alone did not impact the oysters’ immune function at all. Researchers tested the oysters’ feeding rates and found the mixture of the dispersant and oil had the most toxic effect, followed by oil alone and then the dispersant alone.

“Knowing the effects dispersants and oil have on oysters can help us make better mitigation recommendations the next time an environmental and ecological crisis like this happens,” said Dr. Kelly Diehl, Morris Animal Foundation Interim Vice President of Scientific Programs. “Species are interconnected, and what harms oysters will likely cascade through their ecosystem to the detriment of all.”

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In a new study, Cornell University researchers conducted a randomized experiment and found that diners at full service restaurants whose menus listed calories ordered meals with 3 percent fewer calories — about 45 calories less — than those who had menus without calorie information. Customers ordered fewer calories in their appetizer and entree courses, but their dessert and drink orders remained the same.

“Even if you’re an educated person who eats out a lot and is aware of nutrition, there can still be surprising things in these calorie counts,” said co-author John Cawley, professor of policy analysis and management in the College of Human Ecology.

Even the chefs at the restaurants in the study were startled by the high number of calories in some dishes, such as a tomato soup/grilled cheese sandwich combo. “They would have said it was one of the lower-calorie items on the menu,” said co-author Alex Susskind, associate professor of operations, technology and information management at the School of Hotel Administration.

The findings come at a time when most Americans don’t have a precise estimate of how many calories they’re eating, because one-third of their food is prepared outside the home. At the same time, the obesity crisis in America has reached epidemic proportions; the prevalence of obesity in adults has nearly tripled in the past 50 years, to nearly 40 percent of the population in 2016.

In response, many cities, counties and states have passed laws requiring restaurants to include calorie information on their menus. And as of May, it is a nationwide requirement that chain restaurants with 20 or more units post calories on menus and menu boards, as part of the Affordable Care Act of 2010.

To find out how this law affects consumer behavior, the researchers conducted a randomized field experiment in two full-service restaurants. Each party of diners was randomly assigned to either a control group, which received the usual menus, or a treatment group, which got the same menus but with calorie counts next to each item. At the end of the meal, each diner was asked to complete a survey that collected sociodemographic information and attitudes toward diet and exercise. In all, the researchers gathered data from 5,550 diners.

The study also found that diners valued the calorie information. Majorities of both the treatment and control groups supported having calorie labels on menus, and exposure to the calorie counts increased support by nearly 10 percent. “It’s clear that people value this information,” Cawley said.

And there was no downside for restaurants. Their revenue, profit and labor costs were unchanged.

“It’s a cheap policy to put in place, and the fact that there is a reduction in calories ordered makes it appealing,” Cawley said.

The study, “The Impact of Information Disclosure on Consumer Behavior,” was released in August by the National Bureau of Economic Research and co-written with Cawley’s former doctoral advisee Barton Willage, Ph.D., who is now an assistant professor of economics at Louisiana State University.

The work was supported by Cornell’s Institute for the Social Sciences, the Institute for Healthy Futures, the Building Faculty Connections Program and the College of Human Ecology.

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Researchers at Skaggs School of Pharmacy and Pharmaceutical Sciences at University of California San Diego have now identified three new molecular drug targets in N. fowleri and a number of drugs that are able to inhibit the amoeba’s growth in a laboratory dish. Several of these drugs are already approved by the U.S. Food and Drug Administration for other uses, such as antifungal agents, the breast cancer drug tamoxifen and antidepressant Prozac.

Their findings are published September 13 in PLoS Pathogens.

“Not many drugs can cross the blood-brain barrier,” said senior author Larissa Podust, PhD, associate professor at Skaggs School of Pharmacy. “Even if a drug can inhibit or kill the amoeba in a dish, it will not work in a host animal if it does not make it into the brain. That’s why we started with drugs known for their brain effects.” Podust led the study with co-first authors Anjan Debnath, PhD, assistant professor at Skaggs School of Pharmacy, and Wenxu Zhou, PhD, of Texas Tech University.

Podust and team began by investigating N. fowleri’s sterol biosynthesis pathway — a series of enzymes that build the amoeba’s outer membrane. They inhibited three of these enzymes to see how it would affect the organism’s viability. The researchers found that all three enzymes might make good drug targets. One of these, a sterol isomerase, is similar to a human receptor known to play a role in human neurological conditions, such as addiction, amnesia, pain and depression.

The researchers then tested a number of drugs already known to inhibit these enzymes for their ability to inhibit N. fowleri growth in the lab. All 13 of the new drugs they tested were more potent than miltefosine, an investigational drug currently recommended by the U.S. Centers for Disease Control and Prevention (CDC) for the treatment of primary amebic meningoencephalitis, in combination with other medications.

For example, while it takes 54.5 micromolar (?M) of miltefosine to arrest the growth of half the amoebae growing in a dish, it only took 5.8 ?M of tamoxifen and 31.8 ?M of Prozac. Tamoxifen and Prozac inhibit two different enzymes in N. fowleri’s sterol biosynthesis pathway. When the researchers combined a lower dose of tamoxifen with drugs that inhibit other enzymes in the sterol biosynthesis pathway, they were able to inhibit the growth of 95 percent of N. fowleri. In other words, combination treatment allowed them to inhibit more of the pathogen using lower drug concentrations.

“Drug repurposing is a relevant strategy for this infection because there is little economic incentive for the pharmaceutical industry to develop new drugs to treat these rare diseases,” Debnath said. “Already-approved drugs can also lessen the time and expense required to develop a drug from the laboratory to the clinic.”

According to the CDC, only four of 143 people known to be infected with N. fowleri in the U.S. from 1962 to 2017 have survived. However, the number of the university laboratories conducting research on N. fowleri is few, partly due to a liability for laboratory safety risks. The Center for Discovery and Innovation in Parasitic Diseases at Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego is home to just one of six university-based laboratories worldwide conducting drug discovery research on live N. fowleri, and, based on current publications, the only university in the U.S. with a mouse model of the infection.

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Quantum computers promise a new era in ultra-secure networks, artificial intelligence and therapeutic drugs, and will be able to solve certain problems much faster than today’s computers.

The unconventional lens, which is 100 times thinner than a human hair, could enable a fast and reliable transfer of quantum information from the new-age computers to a network, once these technologies are fully realised.

The device is made of a silicon film with millions of nano-structures forming a metasurface, which can control light with functionalities outperforming traditional systems.

Associate Professor Andrey Sukhorukov said the metasurface camera lens was highly transparent, thereby enabling efficient transmission and detection of information encoded in quantum light.

“It is the first of its kind to image several quantum particles of light at once, enabling the observation of their spooky behaviour with ultra-sensitive cameras,” said Associate Professor Sukhorukov, who led the research with a team of scientists at the Nonlinear Physics Centre of the ANU Research School of Physics and Engineering.

Kai Wang, a PhD scholar at the Nonlinear Physics Centre who worked on all aspects of the project, said one challenge was making portable quantum technologies.

“Our device offers a compact, integrated and stable solution for manipulating quantum light. It is fabricated with a similar kind of manufacturing technique used by Intel and NVIDIA for computer chips.” he said.

The research was conducted at the Nonlinear Physics Centre laboratories, where staff and postgraduate scholars developed and trialled the metasurface camera lens in collaboration with researchers at the Oak Ridge National Laboratory in the United States and the National Central University in Taiwan.

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For around half a century, the ‘Gaia’ hypothesis has provided a unique way of understanding how life has persisted on Earth.

It champions the idea that living organisms and their inorganic surroundings evolved together as a single, self-regulating system that has kept the planet habitable for life — despite threats such as a brightening Sun, volcanoes and meteorite strikes.

However, Professor Tim Lenton from the University of Exeter and famed French sociologist of science Professor Bruno Latour are now arguing that humans have the potential to ‘upgrade’ this planetary operating system to create “Gaia 2.0.”

They believe that the evolution of both humans and their technology could add a new level of “self-awareness” to Earth’s self-regulation, which is at the heart of the original Gaia theory.

As humans become more aware of the global consequences of their actions, including climate change, a new kind of deliberate self-regulation becomes possible where we limit our impacts on the planet.

Professors Lenton and Latour suggest that this “conscience choice” to self-regulate introduces a “fundamental new state of Gaia” — which could help us achieve greater global sustainability in the future.

However, such self-aware self-regulation relies on our ability to continually monitor and model the state of the planet and our effects upon it.

Professor Lenton, Director of Exeter’s new Global Systems Institute, said: “If we are to create a better world for the growing human population this century then we need to regulate our impacts on our life support-system, and deliberately create a more circular economy that relies — like the biosphere — on the recycling of materials powered by sustainable energy.”

The original Gaia Theory was developed in the late 1960’s by James Lovelock, a British scientist and inventor. It suggested that both the organic and inorganic components of Earth evolved together as one single, self-regulating system which can control global temperature and atmospheric composition to maintain its own habitability.

The new perspective article is published in leading journal Science on September 14, 2018.

It follows recent research, led by Professor Lenton, which offered a fresh solution to how the Gaia hypothesis works in real terms: Stability comes from “sequential selection” in which situations where life destabilises the environment tend to be short-lived and result in further change until a stable situation emerges, which then tends to persist.

Once this happens, the system has more time to acquire further properties that help to stabilise and maintain it — a process known as “selection by survival alone.”

Creating transformative solutions to the global changes that humans are now causing is a key focus of the University of Exeter’s new Global Systems Institute.

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Research groups from ETH Zürich and the University of Bern, with financial support by the Swiss National Science Foundation, used electron cryo microscopy in order to obtain the atomic-resolution structure of a very unusual ribosome present in the mitochondria of Trypanosoma brucei, the unicellular parasite that causes sleeping sickness. Their study appeared in the latest issue of Science.

Mitochondria are organelles that can be found in each eukaryotic cell. They are the power plants of the cell and contain their own mitochondrial ribosomes (mitoribosomes). They produce a number of proteins that are essential for these power plants. The mitoribosomes of trypanosomes have the same basic function as ribosomes from other organisms, however, they are specialized for the biology of trypanosomes and their structure deviates substantially.

All ribosomes are composed of two types of components; ribonucleic acid (RNA) and proteins. Intriguingly, the researchers found that mitoribosomes of trypanosomes are larger than any other ribosomes, including the ones found in humans. “The mitoribosomes of trypanosomes are primarily build up by proteins, whereas the structure of other ribosomes is dominated by RNA. Consequently, in trypanosomal mitoribosomes, proteins took over the architectural role of the RNA building blocks,” says ETH professor Nenad Ban. In analogy, a small wooden house would differ from a big concrete construction, but both would need a roof, stairs, windows and so on.

“Furthermore, the comparison between the protein-dominated mitoribosomes of trypanosomes with the RNA-dominated ribosomes of other organisms allows us to better understand the most basic functional elements and building blocks shared between all ribosomes,” Prof. Ban explains.

Trypanosomes are not only an important model system for basic research, but they are also of considerable medical relevance since they cause sleeping sickness, a fatal disease in humans if left untreated. The mitoribosomes are essential for the survival of trypanosomes. As their structure deviates substantially from human ribosomes, they represent a promising drug target to potentially treat sleeping sickness. Comparison between the structures of human and trypanosomal mitochondrial ribosomes could be useful for the identification of selective inhibitors to treat diseases caused by trypanosomes.

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This Bolivia-native species commonly known as tipuana tree is ubiquitous in the city. Researchers at the University of São Paulo’s Bioscience Institute (IB-USP) and Medical School (FM-USP), in collaboration with colleagues at the University of Campinas (IB-UNICAMP), have considered T. tipu the most suitable tree for measuring environmental pollution levels in São Paulo over the long term by analyzing the chemical composition of tree bark and growth rings.

Tests were carried out in order to compare the performance of three of the most common tree species in the city: privet (Ligustrum sp.), sibipiruna or partridgewood (Caesalpinia pluviosa), and tipuana.

With the support of São Paulo Research Foundation — FAPESP via a Thematic Project , a regular research grant and a postdoctoral research scholarship, the research attested a reduction in the levels of pollution by cadmium, copper, nickel and lead in the west of the city in the last 30 years.

The roots of the tipuana tree absorb heavy metals and other chemicals that are present in the atmosphere and fall to the ground in rainwater. These chemicals are transported in sap by the tree’s xylem cells and stored in the wood of its growth rings — those concentric circles visible in a cross-section of the trunk.

Each growth ring represents a year of the tree’s life. The more recent rings are wider and farther from the center. Those closest to the center are narrower. The chemical composition of the tree’s growth rings reflects the levels of heavy metals in the soil year by year, and the results can be compared to determine how this type of pollution has varied on a scale of decades.

“If a tree is 50 years old, for example, it will tell the story of pollution in the city during that period,” said Giuliano Maselli Locosselli, a postdoctoral researcher at IB-USP and first author of the study.

All the while Tipuana bark analysis shows the levels of atmospheric chemicals that have been passively deposited in this external part of the trunk.

By measuring the levels of heavy metals in samples of bark from trees still standing in different neighborhoods of the city, the researchers can map spatial variations in these levels on a scale of years.

“It’s easier to obtain samples of bark than annual growth rings, and the chemical analysis of bark is less costly, so we can analyze samples from many trees and cover a large area,” said the FAPESP scholarship holder. “The result is a map of pollution by heavy metals and other chemical elements throughout the city.”

Falling levels of pollution by heavy metals

The researchers conducted an initial study in which they measured the levels of cadmium, copper, mercury, nickel, sodium, lead and zinc in rings from two tipuana specimens growing in the gardens of the University of São Paulo’s Medical School in the west of the city’s central region. Their goal was to analyze the temporal changes in the levels of heavy metal pollution in this part of São Paulo.

The two trees used in this study were 35 years old. Samples were taken from their growth rings using an instrument called a Pressler increment borer, which has a hollow auger bit and is designed to extract a cylindrical section of wood tissue from a living tree throughout its radius with relatively minor injury to the plant itself.

“The procedure can be compared to a tree biopsy,” Locosselli said.

The 15-mm annual growth ring samples were sent to Marco Aurelio Zezzi Arruda, a professor at the University of Campinas’s Chemistry Institute (IQ-UNICAMP). There, the samples were scanned by laser ablation coupled with mass spectrometry, generating software-processed images for chemical analysis.

The researchers selected the cells of interest and performed a continuous analysis of all the annual growth rings to measure the levels of heavy metals absorbed by the trees in each year of their lives.

The data analysis pointed to a significant reduction in pollution by cadmium, copper, nickel and lead in the last three decades in the part of the city inhabited by the sampled tipuana trees, as well as a more moderate decrease in the levels of sodium and zinc.

“The falling levels of lead reflected the gradual elimination of this chemical element from the composition of Brazilian gasoline,” said Marcos Buckeridge, coprincipal investigator at the FAPESP Thematic Project and a coauthor of the study.

“The downtrend in cadmium, copper and nickel pollution probably reflects enhanced vehicle efficiency and deindustrialization in São Paulo,” Buckeridge said.

Tetraethyl lead was used worldwide as an antiknock agent in automotive gasoline for much of the twentieth century to improve engine performance and reduce wear. The resulting release of lead into the atmosphere via vehicle exhaust was a severe health hazard.

Brazil banned the addition of tetraethyl lead to automotive gasoline in 1988.

The main sources of cadmium in ambient air pollution are the electronic appliance industry, pigments used in paint and dye, batteries, photography, lithography, fireworks, plastic, semiconductors, solar cells, fuels, urban garbage, tire rubber, and electroplating. The main sources of copper emissions are the burning of urban and industrial waste, metal alloy casting, and pesticides.

“The levels of these chemical elements in São Paulo’s ambient air have fallen in recent decades owing to deindustrialization,” Locosselli said.

That fluorescent light tracks calcium as it zips across the plant’s tissues, providing an electrical and chemical signal of a threat. In more than a dozen videos like this, University of Wisconsin-Madison Professor of Botany Simon Gilroy and his lab reveal how glutamate — an abundant neurotransmitter in animals — activates this wave of calcium when the plant is wounded. The videos provide the best look yet at the communication systems within plants that are normally hidden from view.

The research is published Sept. 14 in the journal Science. Masatsugu Toyota led the work as a postdoctoral researcher in Gilroy’s lab. Gilroy and Toyota, now at Saitama University in Japan, collaborated with researchers from the Japan Science and Technology Agency, Michigan State University and the University of Missouri.

“We know there’s this systemic signaling system, and if you wound in one place the rest of the plant triggers its defense responses,” says Gilroy. “But we didn’t know what was behind this system.”

“We do know that if you wound a leaf, you get an electrical charge, and you get a propagation that moves across the plant,” Gilroy adds. What triggered that electric charge, and how it moved throughout the plant, were unknown.

But calcium was one candidate. Ubiquitous in cells, calcium often acts as a signal about a changing environment. And because calcium carries a charge, it can also produce an electrical signal. But calcium is ephemeral, spiking and dipping in concentration quickly. The researchers needed a way to see the calcium in real time.

So Toyota developed plants that showed calcium in a whole new light. The plants produce a protein that only fluoresces around calcium, letting the researchers track its presence and concentration. Then came caterpillar bites, scissor cuts and crushing wounds.

In response to each kind of damage, videos show the plants lighting up as calcium flows from the site of damage to other leaves. The signal moved quickly, about one millimeter per second. That’s just a fraction of the speed of animal nerve impulses, but it’s lightning fast in the plant world — quick enough to spread out to other leaves in just a couple minutes. It took just a few more minutes for defense-related hormone levels to spike in distant leaves. These defense hormones help prepare the plant for future threats by, for example, increasing the levels of noxious chemicals to ward off predators.

Previous research by Swiss scientist Ted Farmer has demonstrated that defense-related electrical signals depended on receptors for glutamate, an amino acid that is a major neurotransmitter in animals and also common in plants. Farmer showed that mutant plants missing glutamate receptors also lost their electrical responses to threats. So Toyota and Gilroy looked at the flow of calcium during wounding in these mutant plants.

“Lo and behold, the mutants that knock out the electrical signaling completely knock out the calcium signaling as well,” says Gilroy.

Where normal plants blaze brightly with fluorescent calcium waves during wounding, videos show the mutant plants barely sputtering marginal flashes of light. These results suggest that glutamate spilling out from wound sites triggers the burst in calcium that spreads across the plant.

The study connects decades of research that has revealed how plants, often seen as inert, dynamically respond to threats by preparing distant tissues to deal with future attacks. Glutamate leads to calcium leads to defense hormones and altered growth and biochemistry, all without a nervous system.

Gilroy says that in addition to helping tie all these pieces together, the videos help him visualize the flurry of activity within plants that’s normally invisible.

“Without the imaging and seeing it all play out in front of you, it never really got driven home — man, this stuff is fast!” he says.

This work was supported by grants from the National Science Foundation (MCB-1329273, IOS- 1557899, IOS-1456864), Department of Energy (DE-FG02-91ER20021), NASA (NNX14AT25G) and Japan Science and Technology Agency PRESTO, KAKENHI (17H05007, 18H04775, 18H05491).

Video: https://www.youtube.com/watch?v=Lzq-wRHCTKc