For people with advanced Parkinson’s disease, deep brain stimulation has been shown to be more effective than medication in controlling their movement problems. But research has been mixed on whether the treatment can increase the risk of developing dementia.

For deep brain stimulation, electrodes are placed in certain areas of the brain to control abnormal movements. The electrodes are connected to a device placed under the skin in the upper chest. The device controls the electrical impulses.

“These results are very encouraging for people with Parkinson’s and their families that they can take advantage of the benefits of deep brain stimulation without worrying about it increasing the likelihood of developing dementia,” said study author Elena Moro, MD, of Grenoble Alpes University in Grenoble, France, and a Fellow of the American Academy of Neurology.

The study involved 175 people with Parkinson’s disease with an average age of 56 who had deep brain stimulation. They had Parkinson’s for an average of 12 years when they had the stimulator implanted. Researchers then checked the people after one year, five years and 10 years to see how many people had developed dementia.

After one year, four people had developed dementia, or 2.3%. After five years, 142 people were available for testing and 12 people had dementia, or 8.5%. At 10 years, 104 people were still available for testing and 31 people had dementia, or 29.8%. The overall incidence rate was 35.6 per 1,000 person-years.

“These rates are not higher than those reported in the general population of people with Parkinson’s,” said Moro. “The few studies that are available with similar disease duration have reported higher rates of dementia. Other studies of people with Parkinson’s who are taking medication for their symptoms show an incidence rate for dementia that varies from 50 to 100 per 1,000 person-years.”

Moro said the younger average age in her study may help explain the lower rate of dementia. Also, people with moderate to severe memory or thinking problems are not eligible to have deep brain stimulation, so the group may have been less likely overall to develop dementia than a general group of people with Parkinson’s disease.

The study also looked at factors that were associated with a higher risk of dementia. Researchers found that men, older people, people who had hallucinations, people with a low score on thinking tests before surgery, and those who had a cerebral hemorrhage during the surgery to implant the deep brain stimulator were more likely to develop dementia.

“Knowing these predictors may help us to select people who would respond best to deep brain stimulation and who might have a greater risk of having a poor cognitive outcome,” Moro said.

A limitation of the study was that a high percentage of people did not finish the study; researchers were not able to locate them or they did not respond to requests from the researchers. This could result in underestimating the overall incidence of dementia.

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“This is reassuring news for parents,” said study author Lucy Deng, MBBS, of the National Centre for Immunisation Research and Surveillance (NCIRS) in Sydney, Australia. “A febrile seizure can occur following vaccination and understandably can be quite distressing to parents. It can also cause parents to lose confidence in future vaccinations. Now, parents will be relieved to hear that having a febrile seizure following vaccination does not affect the child’s development.”

The study compared 62 children who had a fever-associated seizure within two weeks after a vaccination with 70 children who had a fever-associated seizure from another cause and 90 children without a history of seizures. All of the children who had seizures were younger than 2-1/2 years old at the time of the seizure.

The children’s cognitive, motor and language functions were tested by certified developmental assessors who did not know the child’s seizure history. Their behavior was also assessed through questionnaires completed by their parents. The children with seizures were tested within one to two years after the seizure.

The researchers found no differences in development, thinking skills or behavior between the children who had febrile seizures following a vaccination and those who had febrile seizures at other times or those who never had a seizure.

“At a time when there is a global resurgence of measles and new diseases are emerging, our findings are particularly important in reassuring parents and providers on the safety of vaccines,” Deng said.

Deng also pointed out that several other factors were not associated with having developmental problems: fever-associated seizures before the age of one; a febrile seizure lasting for more than 15 minutes; or more fever-associated seizures after the first seizure.

Limitations of the study include a relatively small number of participants. Also, further studies should follow children for longer periods of time.

The study was supported by the Australian National Health and Medical Research Council.

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UC Santa Barbara’s Joe Hennawi, a professor in the Department of Physics, and former UCSB postdoctoral scholars Frederick Davies and Feige Wang, provided crucial modeling and data analysis tools that enabled this discovery. The results are currently in preprint on ArXiv and will appear in The Astrophysical Journal Letters.

The researchers have named the object Pōniuā’ena, which means “unseen spinning source of creation, surrounded with brilliance” in the Hawaiian language. It is the first quasar to receive an indigenous Hawaiian name.

Quasars are incredibly bright sources of radiation that lie at the centers of distant massive galaxies. Matter spiraling onto a supermassive black hole generates tremendous amounts of heat making it glow at ultraviolet and optical wavelengths. “They are the most luminous objects in the Universe,” Hennawi said, “outshining their host galaxies by factors of more than a hundred.”

Since the discovery of the first quasar, astronomers have been keen to determine when they first appeared in our cosmic history. By systematically searching for these rare objects in wide-area sky surveys, astronomers discovered the most distant quasar (named J1342+0928) in 2018 and now the second-most distant, Pōniuā’ena (or J1007+2115).

The team first detected Pōniuā’ena as a possible quasar after combing through large area surveys. In 2019, the researchers observed the object using the W. M. Keck Observatory and Gemini Observatory on Mauna Kea, in Hawaii, confirming its existence and identity.

Pōniuā’ena is only the second quasar yet detected at a distance calculated at a cosmological redshift greater than 7.5, or 13 billion light years from Earth. It hosts a black hole twice as large as the other quasar known from the same era. The existence of these massive black holes at such early times challenges current theories of how supermassive black holes formed and grew in the young universe.

A cosmological puzzle

Spectroscopic observations from Gemini and Keck show the black hole powering Pōniuā’ena is 1.5 billion times more massive than our Sun. “Pōniuā’ena is the most distant object known in the universe hosting a black hole exceeding one billion solar masses,” said lead author Jinyi Yang, a postdoctoral research associate at the University of Arizona.

Black holes grow by accreting matter. In the standard picture, supermassive black holes grow from a much smaller “seed” black hole, which could have been the remnant of a massive star that died. “So it is puzzling how such a massive black hole can exist so early in the universe’s history because there does not appear to be enough time for them to grow given our current understanding,” Davies explained.

For a black hole of this size to form this early in the universe, it would need to start as a 10,000-solar-mass seed black hole only 100 million years after the Big Bang — as opposed to growing from a much smaller black hole formed by the collapse of a single star.

“How can the universe produce such a massive black hole so early in its history?” said Xiaohui Fan, at the University of Arizona. “This discovery presents the biggest challenge yet for the theory of black hole formation and growth in the early universe.” The discovery of a more exotic mechanism to form the seed black hole may be required to explain the mere existence of Pōniuā’ena.

The Epoch of Reionization

Current theory holds that the birth of stars and galaxies as we know them started during the Epoch of Reionization. Beginning about 400 million years after the Big Bang, the diffuse matter in between galaxies went from being neutral hydrogen to ionized hydrogen. The growth of the first giant black holes is thought to have occurred during this time.

The discovery of quasars like Pōniuā’ena, deep in the reionization epoch, is a big step towards understanding this process of reionization and the formation of early supermassive black holes and massive galaxies. Pōniuā’ena has placed new and important constraints on the evolution of the intergalactic medium in the reionization epoch.

“Pōniuā’ena acts like a cosmic lighthouse. As its light travels the long journey towards Earth, its spectrum is altered by diffuse gas in the intergalactic medium which allowed us to pinpoint when the Epoch of Reionization occurred,” said Hennawi. The modeling and data analysis method used to infer information about the Epoch of Reionization from these distant quasar spectra was developed in his research group at UC Santa Barbara with Davies and Wang.

“Through University of California Observatories, we have privileged access to the Keck telescopes on the summit of Mauna Kea, which allowed us to obtain high quality data on this object shortly after it was discovered using the Gemini telescope,” Hennawi said.

Finding these distant quasars is a needle in a haystack problem. Astronomers must mine digital images of billions of celestial objects in order to find quasar candidates. “Even after you identify the candidates, the current success rate of finding them is about 1%, and this involves spending lots of expensive telescope time observing contaminants,” Wang explained.

Fortunately, Hennawi and his group are developing machine learning tools to analyze this big data and make the process of finding distant quasars more efficient. “In the coming years the European Space Agency’s Euclid satellite and NASA’s James Webb Space Telescope will enable us to find perhaps a hundred quasars at this distance, or farther,” he said. “With a large statistical sample of these objects we will be able to construct a precise timeline of the reionization epoch as well as shed more light on the black hole growth puzzle.”

Researchers found that those who were more regularly absent in these early years of school were less likely to vote, reported having greater economic difficulties and had poorer educational outcomes when they were 22 to 23 years old.

The results suggest early school absenteeism should be taken more seriously, said Arya Ansari, lead author of the study and assistant professor of human sciences at The Ohio State University.

“There’s this misconception, especially among parents, that it doesn’t matter as much if kids miss school early on — that it only becomes important when they get to middle or high school,” said Ansari, who is also a researcher at Ohio State’s Crane Center for Early Childhood Research and Policy.

“This study shows that those early absences do matter, and in ways that many people don’t consider.”

The study was published online recently in the Journal of Youth and Adolescence.

Ansari and his colleagues used data from the Study of Early Child Care and Youth Development, which is run by the National Institute of Child Health and Human Development.

This study included data on 648 students from 10 cities across the United States who were followed from birth through young adulthood. Researchers had information on the number of days the children were absent from school between kindergarten and eighth grade.

In 2013 and 2014, when the participants were 22 or 23 years old, they reported on a variety of outcomes, from criminal or deviant behavior to parenthood, political participation and economic hardship.

Results showed that school absenteeism didn’t have any relation with criminal, risky or deviant behavior, Ansari said. But it was linked to political engagement and educational and economic success.

Students who were more frequently absent from school were 4.7 percentage points less likely to have voted in the 2012 election.

They also reported experiencing greater economic hardship (such as difficulty paying bills), were more likely to say they used government assistance such as food stamps, were less likely to have a job and reported poorer educational outcomes, such as a lower high school GPA and a lower likelihood of going to college.

“Absenteeism in those early years of school has pretty far-reaching consequences,” Ansari said. “It goes beyond just affecting your education and how well you do in high school.”

Ansari said showing up less to school in those early years may set dangerous precedents.

“If you start out being disengaged with school, you may end up being less engaged with society more broadly. You’re less likely to vote, less likely to go to college, less likely to be employed,” he said.

“We believe disengagement may be one of the key mechanisms linking early school absences to poorer outcomes in early adulthood.”

Ansari said the participants in this study were mostly from middle-class families, so results may be different for those from a more disadvantaged background.

“If we’re seeing these negative outcomes of absenteeism in this largely middle-class sample, the associations may be even more pronounced among disadvantaged families,” he said.

In 2020, parents may be wondering how widespread school closings during the pandemic may be affecting their children. Ansari said this situation is different from what they studied here.

“These really are unprecedented times. All kids are absent. With that said, the differential access to supports and resources will likely result in even greater variability in outcomes when students return to school after the pandemic.”

Ansari said he hopes this study will make parents more aware of the importance of school attendance, even for young children.

“What this work suggests is that we should take absenteeism and its consequences more seriously.”

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“Neutrinos are subatomic particles so tiny that their mass is nearly zero and they rarely interact with other matter,” said Kohta Murase, assistant professor of physics and of astronomy and astrophysics at Penn State and a member of Center for Multimessenger Astrophysics in the Institute for Gravitation and the Cosmos (IGC), who led the research. “High-energy cosmic neutrinos are created by energetic cosmic-ray accelerators in the universe, which may be extreme astrophysical objects such as black holes and neutron stars. They must be accompanied by gamma rays or electromagnetic waves at lower energies, and even sometimes gravitational waves. So, we expect the levels of these various `cosmic messengers’ that we observe to be related. Interestingly, the IceCube data have indicated an excess emission of neutrinos with energies below 100 teraelectron volt (TeV), compared to the level of corresponding high-energy gamma rays seen by the Fermi Gamma-ray Space Telescope.”

Scientists combine information from all of these cosmic messengers to learn about events in the universe and to reconstruct its evolution in the burgeoning field of “multimessenger astrophysics.” For extreme cosmic events, like massive stellar explosions and jets from supermassive black holes, that create neutrinos, this approach has helped astronomers pinpoint the distant sources and each additional messenger provides additional clues about the details of the phenomena.

For cosmic neutrinos above 100 TeV, previous research by the Penn State group showed that it is possible to have concordance with high-energy gamma rays and ultra-high-energy cosmic rays which fits with a multimessenger picture. However, there is growing evidence for an excess of neutrinos below 100 TeV, which cannot simply be explained. Very recently, the IceCube Neutrino Observatory reported another excess of high-energy neutrinos in the direction of one of the brightest active galaxies, known as NGC 1068, in the northern sky.

“We know that the sources of high-energy neutrinos must also create gamma rays, so the question is: Where are these missing gamma rays?” said Murase. “The sources are somehow hidden from our view in high-energy gamma rays, and the energy budget of neutrinos released into the universe is surprisingly large. The best candidates for this type of source have dense environments, where gamma rays would be blocked by their interactions with radiation and matter but neutrinos can readily escape. Our new model shows that supermassive black hole systems are promising sites and the model can explain the neutrinos below 100 TeV with modest energetics requirements.”

The new model suggests that the corona — the aura of superhot plasma that surrounds stars and other celestial bodies — around supermassive black holes found at the core of galaxies, could be such a source. Analogous to the corona seen in a picture of the Sun during a solar eclipse, astrophysicists believe that black holes have a corona above the rotating disk of material, known as an accretion disk, that forms around the black hole through its gravitational influence. This corona is extremely hot (with a temperature of about one billion degrees kelvin), magnetized, and turbulent. In this environment, particles can be accelerated, which leads to particle collisions that would create neutrinos and gamma rays, but the environment is dense enough to prevent the escape of high-energy gamma rays.

“The model also predicts electromagnetic counterparts of the neutrino sources in `soft’ gamma-rays instead of high-energy gamma rays,” said Murase. “High-energy gamma rays would be blocked but this is not the end of the story. They would eventually be cascaded down to lower energies and released as `soft’ gamma rays in the megaelectron volt range, but most of the existing gamma-ray detectors, like the Fermi Gamma-ray Space Telescope, are not tuned to detect them.”

There are projects under development that are designed specifically to explore such soft gamma-ray emission from space. Furthermore, upcoming and next-generation neutrino detectors, KM3Net in the Mediterranean Sea and IceCube-Gen2 in Antarctica will be more sensitive to the sources. The promising targets include NGC 1068 in the northern sky, for which the excess neutrino emission was reported, and several of the brightest active galaxies in the southern sky.

“These new gamma-ray and neutrino detectors will enable deeper searches for multimessenger emission from supermassive black hole coronae,” said Murase. “This will make it possible to critically examine if these sources are responsible for the large flux of mid-energy level neutrinos observed by IceCube as our model predicts.”

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An experiment with undergraduates studying introductory economics classes at Southern Methodist University (SMU) in the USA, published in the American Economic Journal: Applied Economics, revealed that female students were hugely more likely to study the subject further having encountered successful female graduates of the same course.

Researchers from Texas A&M University and Lancaster University engaged two role models — chosen with the help of two current female economics majors — to speak with classes of undergraduates studying principles of economics classes about how their choice of major contributed to their success. They measured the uptake of future economics classes among that group when compared with those studying the same course who had no such interaction with the successful women.

Female students’ enrolment in further economics classes almost doubled following the role models encounter, going against general patterns in recent years showing little progress in attracting women to the field.

“Our results show that role model intervention had a significant impact on all outcomes for female students,” said report co-author Associate Professor Danila Serra, of Texas A&M University. “Being in a class that received the role model visits increased the likelihood that a female student would major in economics by almost 100 per cent. The probability of them taking intermediate or any other economics classes also increased by large margins.

“There is strong evidence of the impact of female role models on female students moving into fields of study in which men are traditionally over-represented, and that the encounters served as an inspiration.”

Principles of economics classes at SMU are typically gender-balanced, with between 44 and 47 per cent of students female. In contrast, for the next step up, only 26 per cent of students are women, and the gender imbalance worsens by graduation, with less than a quarter of economics degrees awarded to women.

“Due to historical gender imbalances in some subjects, such as economics, it is difficult for young women to come into direct contact with successful women who have majored in these fields and who can inspire them to do the same,” said report co-author Dr Catherine Porter, of Lancaster University Management School. “Our study suggests that role model intervention could have a significant impact on the treated women’s lifetime income streams.

“Our research shows that the long-term goal of moving towards gender parity in the economics profession at all levels could be achieved simply and at a relatively low cost by exposing students enrolled in principles classes to successful and inspiring alumnae.”

The researchers’ data shows the majority of those women impacted were previously planning to major in lower-earning humanities fields, and the effect did not decrease the number of them majoring in male-dominated, higher-paying fields such as STEM and finance. Those women who swayed towards economics also performed as well, if not better, in exams as the control students, showing the attraction towards the change affected seemingly qualified women who were not previously pursuing economics. Thus, there could be a positive impact on their potential future earnings.

While the effect on female students in the role model classes was marked, there was no effect on the male students in the same groups.

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