New research about Jupiter proves that point — and adds to the intrigue.

Peter Delamere, a professor of space physics at the University of Alaska Fairbanks Geophysical Institute, is among an international team of 13 researchers who have made a key discovery related to the aurora of our solar system’s largest planet.

The team’s work was published April 9, 2021, in the journal Science Advances. The research paper, titled “How Jupiter’s unusual magnetospheric topology structures its aurora,” was written by Binzheng Zhang of the Department of Earth Sciences at the University of Hong Kong; Delamere is the primary co-author.

Research done with a newly developed global magnetohydrodynamic model of Jupiter’s magnetosphere provides evidence in support of a previously controversial and criticized idea that Delamere and researcher Fran Bagenal of the University of Colorado at Boulder put forward in a 2010 paper — that Jupiter’s polar cap is threaded in part with closed magnetic field lines rather than entirely with open magnetic field lines, as is the case with most other planets in our solar system.

“We as a community tend to polarize — either open or closed — and couldn’t imagine a solution where it was a little of both,” said Delamere, who has been studying Jupiter since 2000. “Yet in hindsight, that is exactly what the aurora was revealing to us.”

Open lines are those that emanate from a planet but trail off into space away from the sun instead of reconnecting with a corresponding location in the opposite hemisphere.

On Earth, for example, the aurora appears on closed field lines around an area referred to as the auroral oval. It’s the high latitude ring near — but not at — each end of Earth’s magnetic axis.

Within that ring on Earth, however, and as with some other planets in our solar system, is an empty spot referred to as the polar cap. It’s a place where magnetic field lines stream out unconnected — and where the aurorae rarely appear because of it. Think of it like an incomplete electrical circuit in your home: No complete circuit, no lights.

Jupiter, however, has a polar cap in which the aurora dazzles. That puzzled scientists.

The problem, Delamere said, is that researchers were so Earth-centric in their thinking about Jupiter because of what they had learned about Earth’s own magnetic fields.

The arrival at Jupiter of NASA’s Juno spacecraft in July 2016 provided images of the polar cap and aurora. But those images, along with some captured by the Hubble Space Telescope, couldn’t resolve the disagreement among scientists about open lines versus closed lines.

So Delamere and the rest of the research team used computer modeling for help. Their research revealed a largely closed polar region with a small crescent-shaped area of open flux, accounting for only about 9 percent of the polar cap region. The rest was active with aurora, signifying closed magnetic field lines.

Jupiter, it turns out, possesses a mix of open and closed lines in its polar caps.

“There was no model or no understanding to explain how you could have a crescent of open flux like this simulation is producing,” he said. “It just never even entered my mind. I don’t think anybody in the community could have imagined this solution. Yet this simulation has produced it.”

“To me, this is a major paradigm shift for the way that we understand magnetospheres.”

What else does this reveal? More work for researchers.

“It raises many questions about how the solar wind interacts with Jupiter’s magnetosphere and influences the dynamics,” Delamere said.

Jupiter’s aurorally active polar cap could, for example, be due to the rapidity of the planet’s rotation — once every 10 hours compared to Earth’s once every 24 hours — and the enormity of its magnetosphere. Both reduce the impact of the solar wind, meaning the polar cap magnetic field lines are less likely to be torn apart to become open lines.

And to what extent does Jupiter’s moon Io affect the magnetic lines within Jupiter’s polar cap? Io is electrodynamically linked to Jupiter, something unique in our solar system, and as such is constantly stripped of heavy ions by its parent planet.

As the paper notes, “The jury is still out on the magnetic structure of Jupiter’s magnetosphere and what exactly its aurora is telling us about its topology.”

With the help of the uncrewed submarine Ran that made its way under Thwaites glacier front, the researchers have made a number of new discoveries. Professor Karen Heywood of the University of East Anglia commented:

“This was Ran’s first venture to polar regions and her exploration of the waters under the ice shelf was much more successful than we had dared to hope. We plan to build on these exciting findings with further missions under the ice next year.”

The submersible has, among other things, measured the strength, temperature, salinity and oxygen content of the ocean currents that go under the glacier.

Global sea level is affected by how much ice there is on land, and the biggest uncertainty in the forecasts is the future evolution of the West Antarctic Ice Sheet, says Anna Wåhlin, professor of oceanography at the University of Gothenburg and lead author of the new study now published in Science Advances.

Impacts global sea level

The ice sheet in West Antarctica accounts for about ten percent of the current rate of sea level rise; but also the ice in West Antarctica holds the most potential for increasing that rate because the fastest changes worldwide are taking place in the Thwaites Glacier. Due to its location and shape, Thwaites is particularly sensitive to warm and salty ocean currents that are finding their way underneath it.

This process can lead to an accelerated melting taking place at the bottom of the glacier and inland movement of the so-called grounding zone, the area where the ice transitions from resting on the seabed to floating in the ocean.

Due to its inaccessible location, far from research stations, in an area that is usually blocked by thick sea ice and many icebergs, there has been a great shortage of in situ measurements from this area. This means that there are big knowledge gaps for the ice-ocean boundary processes in this region.

First measurements performed

In the study, the researchers present the results from the submersible that measured strength, temperature, salinity and oxygen content of the ocean currents that go under the glacier.

“These were the first measurements ever performed beneath Thwaites glacier,” says Anna Wåhlin.

The results have been used to map the ocean currents underneath the floating part of the glacier. The researchers discovered that there is a deep connection to the east through which deep water flows from Pine Island Bay, a connection that was previously thought to be blocked by an underwater ridge.

The research group has also measured the heat transport in one of the three channels that lead warm water towards Thwaites Glacier from the north. “The channels for warm water to access and attack Thwaites weren’t known to us before the research. Using sonars on the ship, nested with very high-resolution ocean mapping from Ran, we were able to find that there are distinct paths that water takes in and out of the ice shelf cavity, influenced by the geometry of the ocean floor” says Dr Alastair Graham, University of Southern Florida.

The value measured there, 0.8 TW, corresponds to a net melting of 75 km3 of ice per year, which is almost as large as the total basal melt in the entire ice shelf. Although the amount of ice that melts as a result of the hot water is not much compared to other global freshwater sources, the heat transport has a large effect locally and may indicate that the glacier is not stable over time.

Not sustainable over time

The researchers also noted that large amounts of meltwater flowed north away from the front of the glacier.

Variations in salinity, temperature and oxygen content indicate that the area under the glacier is a previously unknown active area where different water masses meet and mix with each other, which is important for understanding the melting processes at the base of the ice.

The observations show warm water approaching from all sides on pinning points, critical locations where the ice is connected to the seabed and give stability to the ice shelf. Melting around these pinning points may lead to instability and retreat of the ice shelf and, subsequently, the upstream glacier flowing off the land. Dr Rob Larter of the British Antarctic Survey commented:

“This work highlights that how and where warm water impacts Thwaites Glacier is influenced by the shape of the sea floor and the ice-shelf base as well as the properties of the water itself. The successful integration of new sea-floor survey data and observations of water properties from the Ran missions shows the benefits of the multidisciplinary ethos within the International Thwaites Glacier Collaboration.”

“The good news is that we are now, for the first time, collecting data that is necessary to model the dynamics of Thwaite’s glacier. This data will help us better calculate ice melting in the future. With the help of new technology, we can improve the models and reduce the great uncertainty that now prevails around global sea level variations.” says Anna Wåhlin.

Now a new study describes antibodies capable of neutralizing the virus transmitted by tick bites. These so-called broadly neutralizing antibodies have shown promise in preventing TBE in mice and could inform the development of better vaccines for humans. Further, preliminary results suggest that the antibodies may not only prevent tick-borne encephalitis but even treat the condition, as well as the related Powassan virus emerging in the United States.

Lead author Marianna Agudelo and colleagues in the laboratory of Rockefeller’s Michel C. Nussenzweig examined nearly 800 antibodies obtained from individuals who had recovered from TBE or had been vaccinated to prevent infection. The most potent antibodies, designated VH3-48, turned out to be best suited to fend off future infections. They found that VH3-48 neutralized lab-grown varieties of the TBE virus, as well other tick-borne illnesses including the Langat, Louping ill, Omsk hemorrhagic fever, Kyasanur forest disease, and Powassan viruses.

The researchers also showed that these powerful antibodies are not common; in fact, most of the antibodies produced by humans exposed to TBE virus are of inferior quality, with the coveted VH3-48 antibodies making only occasional appearances. Moreover, vaccinated patients in the study did not manage to develop any VH3-48 antibodies at all. “You’d expect the most prevalent antibodies to be the absolute best, but that is not what we found in TBE,” Agudelo says. “This may explain how the virus tricks the immune system, misdirecting it into producing inferior antibodies.”

The discovery of VH3-48 provides hope for a more effective TBE vaccine. Current vaccines require three doses spaced over two years and only provide about five years of protection before a booster shot is required. Next-generation vaccines built around coaxing the body into producing the rare VH3-48 antibody could be more potent, require fewer booster shots, and also prove protective against a number of tick-borne viruses.

“A vaccine like this would not just be more elegant, but also better focused,” says Michel C. Nussenzweig, the Zanvil A. Cohn and Ralph M. Steinman Professor and head of the Laboratory of Molecular Immunology at Rockefeller. “Now that we have the structures of these antibodies, we know what to target in order to design more effective vaccines.”

Broadly neutralizing antibodies may also provide the first specific treatment for TBE. Nussenzweig, Agudelo, and colleagues found that mice infected with TBE recover after receiving antibody therapy, although it remains to be seen if this finding will translate to humans.

“The next step is a clinical trial with the antibodies,” Nussenzweig says, “perhaps in Europe where there are many cases, to see whether we can ameliorate the symptoms of those suffering from encephalitis.”

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The new data demonstrate that aluminum is co-located with phosphorylated tau protein, present as tangles within neurons in the brains of early-onset or familial Alzheimer’s disease. “The presence of these tangles is associated with neuronal cell death, and observations of aluminum in these tangles may highlight a role for aluminum in their formation,” explained lead investigator Matthew John Mold, PhD, Birchall Centre, Lennard-Jones Laboratories, Keele University, Staffordshire, UK.

The earlier research highlighted widespread co-localization of aluminum and amyloid-β in brain tissue in familial AD. The researchers used a highly-selective method of immunolabelling in the current study, combined with aluminum-specific fluorescence microscopy. Phosphorylated tau in tangles co-located with aluminum in the brain tissue of the same cohort of Colombian donors with familial AD were identified. “It is of interest and perhaps significance with respect to aluminum’s role in AD that its unequivocal association with tau is not as easily recognizable as with amyloid-β. There are many more aggregates of aluminum with amyloid-β than with tau in these tissues and the latter are predominantly intracellular,” remarked co-author, Professor Christopher Exley.

George Perry, PhD, Editor-in-Chief of the Journal of Alzheimer’s Disease, comments: “Aluminum accumulation has been associated with Alzheimer’s disease for nearly half a century, but it is the meticulously specific studies of Drs. Mold and Exley that are defining the exact molecular interaction of aluminum and other multivalent metals that may be critical to formation of the pathology of Alzheimer’s disease.”

“The new data may suggest that the association of aluminum with extracellular senile plaques precedes that with intracellular aggregates of tau. These relationships with both amyloid-β and tau may account for the high levels of aluminum observed in the brain tissue of donors with familial AD versus those without a diagnosis of neurodegenerative disease,” said Dr. Mold. “Tau and amyloid-beta are known to act in synergy to produce neurotoxicity in AD and our data provide new evidence for a role of aluminum in this process.”

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The study specifically suggests that the effects of job strain and social strain — the negative aspect of social relationships — on women is a powerful one-two punch. Together they are associated with a 21% higher risk of developing coronary heart disease. Job strain occurs when a woman has inadequate power in the workplace to respond to the job’s demands and expectations.

The study also found that high-stress life events, such as a spouse’s death, divorce/separation or physical or verbal abuse, as well as social strain, were each independently linked with a 12% and 9% higher risk of coronary heart disease, respectively.

The Drexel study used data from a nationally representative sample of 80,825 postmenopausal women from the Women’s Health Initiative Observational Study, which tracked participants from 1991 to 2015, to find better methods of preventing cancer, heart disease and osteoporosis in women. In the current follow-up study, Drexel researchers evaluated the effect of psychosocial stress from job strain, stressful life events and social strain (through a survey), and associations among these forms of stress, on coronary heart disease.

Nearly 5% of the women developed coronary heart disease during the 14-year, seven-month study. Adjusting for age, time at a job, and socioeconomic characteristics, high-stress life events were associated with a 12% increased coronary heart disease risk, and high social strain was associated with a 9% increased risk of coronary heart disease. Work strain was not independently associated with coronary heart disease.

Coronary heart disease, the leading cause of death in the United States, occurs with the heart’s arteries become narrow and cannot bring sufficient oxygenated blood to the heart. The latest work builds on earlier studies linking psychosocial stress to coronary heart disease by finding out how job strain and social strain work together to compound disease risk.

“The COVID-19 pandemic has highlighted ongoing stresses for women in balancing paid work and social stressors. We know from other studies that work strain may play a role in developing CHD, but now we can better pinpoint the combined impact of stress at work and at home on these poor health outcomes,” said senior author Yvonne Michael, ScD, SM, an associate professor in the Dornsife School of Public Health. “My hope is that these findings are a call for better methods of monitoring stress in the workplace and remind us of the dual-burden working women face as a result of their unpaid work as caregivers at home .”

The study’s authors say that future studies should look at the effects of shift work on coronary heart disease and explore the effects of job demands according to gender.

“Our findings are a critical reminder to women, and those who care about them, that the threat of stress to human health should not go ignored,” said lead author Conglong Wang, PhD, a recent Dornsife graduate who conducted the research while at Drexel. “This is particularly pertinent during the stressors caused by a pandemic.”

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Usually defects are considered something “bad” that negatively affects the properties of a material, making it less perfect. However, in certain nanomaterials such as carbon nanotubes these “imperfections” can result in something “good” and enable new functionalities. Here, the precise type of defects is crucial. Carbon nanotubes consist of rolled-up sheets of a hexagonal lattice of sp2 carbon atoms, as they also occur in benzene. These hollow tubes are about one nanometer in diameter and up to several micrometers long.

Through certain chemical reactions, a few sp2 carbon atoms of the lattice can be turned into sp3 carbon, which is also found in methane or diamond. This changes the local electronic structure of the carbon nanotube and results in an optically active defect. These sp3 defects emit light even further in the near-infrared and are overall more luminescent than nanotubes that have not been functionalised. Due to the geometry of carbon nanotubes, the precise position of the introduced sp3 carbon atoms determines the optical properties of the defects. “Unfortunately, so far there has been very little control over what defects are formed,” says Jana Zaumseil, who is a professor at the Institute for Physical Chemistry and a member of the Centre for Advanced Materials at Heidelberg University.

The Heidelberg scientist and her team recently demonstrated a new chemical reaction pathway that enables defect control and the selective creation of only one specific type of sp3 defect. These optically active defects are “better” than any of the previously introduced “imperfections.” Not only are they more luminescent, they also show single-photon emission at room temperature, Prof. Zaumseil explains. In this process, only one photon is emitted at a time, which is a prerequisite for quantum cryptography and highly secure telecommunication.

According to Simon Settele, a doctoral student in Prof. Zaumseil’s research group and the first author on the paper reporting these results, this new functionalisation method — a nucleophilic addition — is very simple and does not require any special equipment. “We are only just starting to explore the potential applications. Many chemical and photophysical aspects are still unknown. However, the goal is to create even better defects.”

This research is part of the project “Trions and sp3-Defects in Single-walled Carbon Nanotubes for Optoelectronics” (TRIFECTs), led by Prof. Zaumseil and funded by an ERC Consolidator Grant of the European Research Council (ERC). Its goal is to understand and engineer the electronic and optical properties of defects in carbon nanotubes.

“The chemical differences between these defects are subtle and the desired binding configuration is usually only formed in a minority of nanotubes. Being able to produce large numbers of nanotubes with a specific defect and with controlled defect densities paves the way for optoelectronic devices as well as electrically pumped single-photon sources, which are needed for future applications in quantum cryptography,” Prof. Zaumseil says.

Also involved in this research were scientists from Ludwig Maximilian University of Munich and the Munich Center for Quantum Science and Technology. 

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