Giant doubts about giant exomoons

The extrasolar planets Kepler-1625b and Kepler-1708b are supposedly the home worlds of the first known exomoons. A new study now comes to a different conclusion.

Peer-Reviewed Publication

MAX-PLANCK-GESELLSCHAFT

 

IMAGE: 

SEVERAL INFLUENCES CAN CREATE A MOON-LIKE SIGNAL IN A LIGHT CURVE – EVEN WITHOUT THE PRESENCE OF AN ACTUAL MOON.

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CREDIT: MPS/HORMESDESIGN.DE

Only two of the more than 5300 known exoplanets have so far provided evidence of moons in orbit around them. In observations of the planets Kepler-1625b and Kepler-1708b from the Kepler and Hubble space telescopes, researchers had discovered traces of such moons for the first time. A new study now raises doubts about these previous claims. As scientists from the Max Planck Institute for Solar System Research (MPS) and the Sonnenberg Observatory, both in Germany, report today in the journal Nature Astronomy, "planet-only" interpretations of the observations are more conclusive. For their analysis, the researchers used their newly developed computer algorithm Pandora, which facilitates and accelerates the search for exomoons. They also investigated what kind of exomoons can be found in principle in modern space-based astronomical observations. Their answer is quite shocking.

In our Solar System, the fact that a planet is orbited by one or more moons is rather the rule than the exception: apart from Mercury and Venus, all other planets have such companions; in the case of the gas giant Saturn researchers have found 140 natural satellites until today. Scientists therefore consider it likely that planets in distant star systems also harbor moons. So far, however, there has only been evidence of such exomoons in two cases: Kepler-1625b and Kepler-1708b. This low yield is not surprising. After all, distant satellites are naturally much smaller than their home worlds - and therefore much harder to find. And it is extremely time-consuming to comb through the observational data of thousands of exoplanets for evidence of moons.

To make the search easier and faster, the authors of the new study rely on a search algorithm they developed and optimized themselves for the search for exomoons. They published their method last year and the algorithm is available to all researchers as open source code. When applied to the observational data from Kepler-1625b and Kepler-1708b, the results were astonishing. "We would have liked to confirm the discovery of exomoons around Kepler-1625b and Kepler-1708b," says first author of the new study, MPS scientist Dr. René Heller. "But unfortunately, our analyses show otherwise," he adds.

Hide and seek of an exomoon

The Jupiter-like planet Kepler-1625b made headlines five years ago. Researchers at Columbia University in New York reported strong evidence of a giant moon in its orbit that would dwarf all the moons in the Solar System. The scientists had analyzed data from NASA's Kepler space telescope, which observed more than 100,000 stars during its first mission from 2009 to 2013 and discovered over 2000 exoplanets. However, in the years that followed the 2018 discovery claim, the exomoon candidate forced astronomers to play a cosmic version of hide-and-seek. First it disappeared after the Kepler data had been cleaned from systematic noise. Yet clues were found again in further observations with the Hubble Space Telescope. And then last year, this extraordinary exomoon candidate got company: according to the New York researchers, another giant moon much larger than Earth orbits the Jupiter-sized planet Kepler-1708b.

The right match

"Exomoons are so far away that we cannot see them directly, even with the most powerful modern telescopes," explains Dr. René Heller. Instead, telescopes record the fluctuations in brightness of distant stars, the time series of which is called a light curve. Researchers then look for signs of moons in these light curves. If an exoplanet passes in front of its star as seen from Earth, it dims the star by a tiny fraction. This event is called a transit, and it re-occurs regularly with the orbital period of the planet around the star. An exomoon accompanying the planet would have a similar dimming effect. Its trace in the light curve, however, would not only be significantly weaker. Due to the movement of the moon and planet around their mutual center of gravity, this additional dimming in the light curve would follow a rather complicated pattern. And there are other effects to be considered, such as planet-moon eclipses, natural brightness variations of the star and other sources of noise generated during telescopic measurements.

In order to detect the moons nevertheless, both the New York researchers and their German colleagues first calculate many millions of "artificial" light curves for all conceivable sizes, mutual distances and orbital orientations of possible planets and moons. An algorithm then compares these simulated light curves with the observed light curve and looks for the best match. The researchers from Göttingen and Sonneberg used their open-source algorithm Pandora, which is optimized for the search for exomoons and can solve this task several orders of magnitude faster than previous algorithms.

No trace of moons

In the case of the planet Kepler-1708b, the German duo now found that scenarios without a moon can explain the observational data just as accurately as those with a moon. "The probability of a moon orbiting Kepler-1708b is clearly lower than previously reported," says Michael Hippke from the Sonneberg Observatory and co-author of the new study. "The data do not suggest the existence of an exomoon around Kepler-1708b," Hippke continues.

There is much to suggest that Kepler-1625b is also devoid of a giant companion. Transits of this planet in front of its star have previously been observed with the Kepler and the Hubble telescopes. The German researchers now argue that the instantaneous brightness variation of the star across its disk, an effect known as stellar limb darkening, has a crucial impact on the proposed exomoon signal. The limb of the solar disk, for example, appears darker than the center. However, depending on whether you look at the home star of Kepler-1625b through the Kepler or the Hubble telescope, this limb darkening effect looks different. This is because Kepler and Hubble are sensitive to different wavelengths of the light that they receive. The researchers from Göttingen and Sonneberg now argue that their modeling of this effect explains the data more conclusively than a giant exomoon.

Their new, extensive analyses also show that exomoon search algorithms often produce false-positive results. Time and again, they "discover" a moon when there really is just a planet transiting its host star. In the case of a light curve like that of Kepler-1625b, the rate of "false hits" is likely to be around 11 percent. "The earlier exomoon claim by our colleagues from New York was the result of a search for moons around dozens of exoplanets," says Heller. "According to our estimates, a false-positive finding is not at all surprising, but almost to be expected," he adds. 

Strange satellites

The researchers also used their algorithm to predict the types of actual exomoons that could be clearly detectable in light curves space missions like Kepler. According to their analysis, only particularly large moons orbiting their planet in a wide orbit are detectable using current technology. Compared to the familiar moons of our Solar System, they would all be oddballs: at least twice the size of Ganymede, the largest moon in the Solar System and therefore almost as big as Earth. "The first exomoons that will be discovered in future observations, such as from the PLATO mission, will certainly be very unusual and therefore exciting to explore," says Heller.

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JOURNAL

Nature Astronomy

DOI

10.1038/s41550-023-02148-w 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Large exomoons unlikely around Kepler-1625 b and Kepler-1708 b

ARTICLE PUBLICATION DATE

7-Dec-2023

 

Three proposals from researchers to meet EU climate goals

Peer-Reviewed Publication

LINKÖPING UNIVERSITY

 

IMAGE: 

MATHIAS FRIDAHL, ASSOCIATE PROFESSOR, LINKÖPING UNIVERSITY, SWEDEN.

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CREDIT: MAGNUS JOHANSSON

The EU countries have decided that the EU is to be climate neutral by 2050. By 2030, greenhouse gas emissions must have been reduced by at least 55% compared to 1990. 
To meet this target, continued vigorous efforts are needed to reduce emissions, but that alone will not be enough. This is the conclusion of seven researchers from Sweden and Germany in an article in the journal Communications Earth & Environment. One of them is Mathias Fridahl, associate professor at the Department of Thematic Studies - Environmental Change at Linköping University, Sweden.

“We have painted humanity into a corner. It’s no longer possible to solve the climate crisis simply by reducing emissions. We also need to clean the atmosphere of carbon dioxide,” says Mathias Fridahl.

The problem is that there are currently no incentives for companies and countries to invest in new technologies to remove carbon dioxide. That is why a change in the EU's climate policy is needed.
“There are many technologies that are quite well developed, but which aren’t economically viable,” says Mathias Fridahl.

He and his colleagues have three proposals that they believe could soon make a difference.

Anyone contributing to the removal of carbon dioxide should be able to get paid for it under the EU emissions trading scheme. This should only apply to methods that have a long life span, that is, capture linked to the storage of carbon dioxide for thousands of years.
To get the trading scheme up and running, the researchers propose that the EU set up a central bank for carbon dioxide. The bank would give investors a good price for the carbon dioxide removed from the atmosphere. In order to maintain the drive to continue reducing emissions at the same time, the proposal is that the bank strongly regulates how removal may be used to compensate for continued emissions.

The bank’s financial muscle could come from revenues from carbon tariffs on goods from outside the Union.

To stimulate other measures with a shorter life span, the researchers propose an extension of the EU’s land use regulation. This sets out the measures to remove carbon dioxide that member states are allowed to be credited with when reporting their climate emissions. Today, there is a limited amount of removal methods in forestry and agriculture. The researchers contend that if the regulation were extended to more measures, it would encourage countries to invest resources in carbon removal.

The researchers also want the EU to identify which emissions will be very difficult or impossible to do anything about. Greater clarity would reduce the risk of companies and member states postponing measures in the hope that their emissions will belong to the group that is difficult to tackle. This would stimulate innovation and efforts to reduce emissions in parallel with initiatives to remove carbon dioxide.

Mathias Fridahl stresses that, if the proposals are implemented, it is important that they are not used to avoid the requirements to simultaneously reduce emissions.
He thinks the issue will be addressed as early as next year. The European Commission is then to present proposals for a new intermediate objective for climate action up to 2040. 
“In this process, the prospects are good for addressing the question of removal methods,” says Mathias Fridahl.

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JOURNAL

Communications Earth & Environment

DOI

10.1038/s43247-023-01121-9 

METHOD OF RESEARCH

Commentary/editorial

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Novel carbon dioxide removals techniques must be integrated into the European Union’s climate policies

ARTICLE PUBLICATION DATE

7-Dec-2023

COI STATEMENT

The authors declare no competing interests. Miranda Böttcher is an Editorial Board Member for Communications Earth & Environment, but was not involved in the editorial review of, nor the decision to publish this article.

 

Acoustic monitoring shows surprising resilience of subtropical forests to extreme weather – but climate change looms

Analysis of 13,000 hours of recorded sound from an acoustic monitoring network across Okinawa Island, Japan, reveals that ecosystems are more resilient to super-typhoons than anticipated but are threatened by climate change.

Peer-Reviewed Publication

OKINAWA INSTITUTE OF SCIENCE AND TECHNOLOGY (OIST) GRADUATE UNIVERSITY

 

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MAP OF OKINAWA WITH DIFFERENT LAND COVER TYPES AND FIELD SITE LOCATIONS DERIVED FROM A 2015 LANDSAT 8 IMAGE. 

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CREDIT: KENNETH DUDLEY, ENVIRONMENTAL SCIENCE AND INFORMATICS SECTION, OIST.

If a tree falls in a forest, and no one is around to hear it, does it make a sound? Researchers from the Okinawa Institute of Science and Technology Graduate University (OIST) have answered this question by remotely recording the soundscapes of Okinawan forests, allowing them to track how extreme weather events like typhoons affect different ecosystems on the island. Overall, they found that the forests were surprisingly resilient – and the soundscapes offer a powerful way to glean crucial information that can guide conservation efforts.

In September 2018, super-typhoon Trami shook Okinawa, and six days later came the slightly less severe typhoon Kong-Rey. To probe the true extent of the damage these storms caused to local wildlife, researchers from OIST and Trinity College Dublin analyzed 13,000 hours of audio from soundscapes collected before, during, and after the typhoons.

The soundscapes were collected as part of the Okinawa Environmental Observation Network (OKEON) Churamori Project, which includes an acoustic monitoring network spanning 24 sites across the island of Okinawa, from the untouched forests in the north to the urban sprawl of the south. OKEON depends on close collaboration between researchers, local experts and institutions in Okinawa, and citizen scientists.

“Working with huge acoustic datasets from natural ecosystems gives a more holistic view of real-world responses to disturbance, which are difficult to observe using theory or laboratory experiments,” says Dr. Samuel Ross from the Integrative Community Ecology Unit at OIST and lead author of the study, which was published in Global Change Biology.

By converting the recordings to numerical data, the researchers were able to detect the overall level of animal sound—the so-called biophony—at each of the 24 sites. They also used supervised machine learning to rapidly identify the bird calls of three Okinawan bird species, which made it possible to track their presence through time and space.

Despite the relatively small size of the island, environments across Okinawa reacted very differently to these massive weather disturbances. “We expected that the ecosystems would respond in the same way to the typhoons, but surprisingly, we got the complete opposite result,” says Dr. Ross.

Instead of typhoons destroying habitats and quietening wildlife, the microphones picked up different numbers of bird calls at the various field sites. Human development didn’t seem to account for the different responses either. “We were surprised by how resilient the developed sites were,” Dr. Ross explained. “We expected that sites where humans have altered the structure of ecosystems would be more vulnerable.”

That resilience may not hold, however. Climate change is bringing larger, longer lasting, and more frequent typhoons that hit further inland. Super-typhoons like Trami used to be very rare, but in August 2023, another one struck. “Ecosystems in Okinawa may be pre-adapted to extreme weather to some degree, which might explain the resilience of these ecosystems to typhoons, but climate change could push these ecosystems to their limit,” says Dr. Ross. “If you hit an ecosystem over and over again with extreme disturbances, eventually there comes a point where it can't take anymore.”

Acoustic monitoring networks such as the OKEON sensor array offer an alternative to costly and labor-intensive traditional ecological monitoring. This approach can also yield targeted recommendations for local conservation efforts in vulnerable areas. The study tracked the calls of three bird species: the large-billed crow, the Ryukyu scops-owl and the Japanese bush warbler. While the crow and the scops-owl resisted the extreme weather events, the number of bush warbler calls diminished, suggesting this bird struggled after the typhoons. With this knowledge, ecosystem managers in Okinawa could focus their conservation efforts on the species worst affected by natural disasters.

 

The three bird species examined in the study. From left to right: Japanese bush warbler, Ryukyu scops-owl, and large-billed crow. 

CREDIT

Patrick Kuhn

Okinawan soundscapes from super-typhoon Trami 

Three audio recordings from Yanbaru forest in Okinawa, Japan, each taken at 06:00. The first 15s clip is from 30 Aug 2018, before super-typhoon Trami, the second is from 29 Sep 2018, during the typhoon, and the final clip is from 29 Oct 2018, after the second typhoon Kong-Rey.

CREDIT

Audio: OKEON Churamori Project. Video (in order of clips): Tomomi Okubo, Andrew Scott, Alexandru Mihai, Andrew Scott, Aya Peloquin, Adrian Skov

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JOURNAL

Global Change Biology

DOI

10.1111/gcb.17067 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Divergent ecological responses to typhoon disturbance revealed via landscape-scale acoustic monitoring

ARTICLE PUBLICATION DATE

7-Dec-2023

 

Children born moderately early are at an increased risk of developmental disorders, according to new research

Children born between 32 and 38 weeks’ gestation are more likely to have developmental disorders – such as language delay, cognitive impairment, ADHD and Cerebral palsy – compared with children born at full term, according to a major new study.

Peer-Reviewed Publication

UNIVERSITY OF YORK

While many of the increased risks are small, because around seven percent of babies in the UK are born moderately preterm each year, they could have significant consequences at population level, the authors of the National Institute of Health and Care Research (NIHR) funded study say. 

For the study, researchers at the Universities of York, Leeds and Leicester examined data from more than 75 studies from around the world, which involved a total of over eight million children. 

Compared with children born at full term, the study identified an increased risk of most developmental disorders. Whilst risks decreased with each week of gestation, there was still evidence of a small increase in risk of several developmental disorders such as cerebral palsy, developmental delay, and cognitive impairment, even when children were  born “early term”, between 37-38 weeks.

One of the most common disorders was language delay which affected 222 per 1000 children born between 32-36 weeks, compared with 47 per 1000 for full term children. Many children face low educational attainment during the primary school years, affecting 300 per 1000 children born moderately preterm, compared to 160 per 1000 children born at full term.

While the risk of cerebral palsy is relatively low for all children, the results of the study suggest it is 14 times higher for infants born at 32 to 33 weeks compared with children born at full term. 

The review also found that difficulties faced by children born at 32 to 38 weeks persist through childhood, with evidence of increased risk and prevalence of cognitive impairment and low educational achievement persisting into the high school years. 

Lead author of the study, Dr Katherine Pettinger from the Department of Health Sciences at the University of York, said: “It is important to remember that whilst our study shows an increase in risk for children born moderately early relative to their peers born at full term, many children will not experience any developmental problems.

“The reasons behind our findings are not yet clear, but babies born just a few weeks early have different brain maturation to full term children, and it is possible that birth between 32 and 38 weeks’ gestation may disrupt evolution of neural connections, potentially contributing to developmental disorder. 

“Many babies that are born moderately preterm are delivered early for very good reasons, for example when the mother has a health condition such as preeclampsia. However, understanding the long-term implications of birth before full term may influence obstetric decision making in some cases. It is also vital that all healthcare professionals, and particularly paediatricians, are well informed of the potential consequences of preterm birth so that they can give evidence based information to families and so opportunities for early intervention are not missed. ” 

According to current guidelines from the National Institute for Health and Care Excellence (NICE) children should be monitored up until the age of two if they were born before the age of 30 weeks.

The researchers do not recommend that all children born between 32 and 38 weeks’ gestation should also receive multiple routine health appointments as many will not show any signs of developmental disorders and this would place significant strain on NHS services. 

However, the researchers are calling for more communication between schools, parents and health professionals and better support for teachers. 

Dr Pettinger added: “The data tells us the effects of being just a few weeks early are still there at primary school age. It therefore makes sense for teachers to be informed if they have students who are born preterm and early term and receive training on how to support them.

“Further research is now needed to look at large scale population studies to explore how incidents of developmental disorders relate to gestational age and see if the patterns we observed in the present study are replicated. We also want to look at whether children are commonly affected by more than one disorder, as understanding which conditions are likely to co-occur can help to produce more tailored interventions for children.”

Risk of Developmental Disorders in Children Born at 32 to 38 Weeks’ Gestation: A Meta-Analysis is published in the journal Pediatrics.

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JOURNAL

PEDIATRICS

DOI

10.1542/peds.2023-061878 

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Risk of Developmental Disorders in Children Born at 32 to 38 Weeks’ Gestation: A Meta-Analysis

 

A dynamic picture of how we respond to high or low oxygen levels

A new study from Gladstone Institutes sheds light on the molecular workings at play when oxygen exceeds normal levels, with findings that may one day inform the decision to use supplemental oxygen as a medical treatment.

Peer-Reviewed Publication

GLADSTONE INSTITUTES

 

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GLADSTONE ASSISTANT INVESTIGATOR Isha Jain, PhD, SENIOR AUTHOR OF THE NEW STUDY, DISCUSSES THE RESEARCH WITH FIRST AUTHOR KIRSTEN XUEWEN CHEN. THEIR FINDINGS EXPLAIN HOW BREATHING AIR WITH DIFFERENT LEVELS OF OXYGEN AFFECTS THE CREATION AND DEGRADATION OF DIFFERENT PROTEINS IN THE LUNGS, HEART, AND BRAIN OF MICE.

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CREDIT: GLADSTONE INSTITUTES

SAN FRANCISCO—December 8, 2023—It only takes holding your breath for slightly too long to understand that too little oxygen is bad for you. But can you also have too much? Indeed, breathing air with a higher oxygen level than your body needs can cause health problems or even death.  

But with scant research on the topic, scientists have known little about how the body senses too much oxygen. Now, a new study from Gladstone Institutes has greatly expanded the scientific body of knowledge about the mechanisms at play, and why it matters for health.

Their findings, reported in the journal Science Advances, explain how breathing air with different levels of oxygen—from too little, to just right, or too much—affects the creation and degradation of different proteins in the lungs, heart, and brain of mice. Notably, the study also highlights a particular protein that may play a central role in regulating how cells respond to hyperoxia.

“These results have implications for many different diseases,” says Gladstone Assistant Investigator Isha Jain, PhD, senior author of the new study. “More than 1 million people in the US breathe supplemental oxygen every day for medical reasons, and studies suggest it could be making things worse in some cases. That’s just one setting where our work is starting to explain what’s happening and how the body responds.”

Understanding Oxygen’s Effects

Most prior research on oxygen levels has examined the molecular effects of too little oxygen. And even in that realm, most of the focus has been on how low oxygen affects which genes are turned on or off.

“Our study enters uncharted territory by using mice and looking downstream of gene expression at which proteins abnormally accumulate or degrade in response to different oxygen concentrations,” says Kirsten Xuewen Chen, first author of the new paper and a graduate student at UC San Francisco.

The research builds on the team’s prior work, which revealed that in response to too much oxygen, certain proteins containing iron and sulfur clusters become degraded, leading cells to malfunction.

“Now, we wanted to get a more dynamic picture of how proteins are regulated when oxygen levels are too high or too low,” Chen says.

To do so, the team exposed mice for several weeks to air with oxygen level of 8 percent, 21 percent (the usual level we breathe in Earth’s atmosphere), or 60 percent. Meanwhile, they gave the mice food containing a distinct form of nitrogen that the animals’ bodies incorporated into new proteins. This nitrogen isotope acted as a “label” that enabled the researchers to calculate protein turnover rates—the balance between protein synthesis and degradation—for thousands of different proteins in the lungs, heart, and brain.

“We’re grateful to our collaborators who are the experts in this technique, known as stable isotope labeling of amino acids in mice,” Jain says. “Without it, we could not have done this study.”

A Key Protein Builds Up

The researchers found that oxygen levels more dramatically affected proteins in the lungs of mice than the heart or brain. They identified certain proteins with abnormal turnover rates under high- or low-oxygen conditions.

One particular protein that accumulated in high-oxygen conditions, MYBBP1A, piqued their attention. MYBBP1A is a transcription regulator, meaning it directly affects gene expression.

“This caught our eye because prior research has shown that other transcription factors called hypoxia-inducible factors, or HIFs, play a big role in cells’ response to low oxygen,” Chen says. “Our work nominates MYBBP1A for a related role in hyperoxia signaling.”

MYBBP1A is involved in the production of ribosomes—cellular “machines” that build proteins. Further experiments surfaced clues that, in response to high oxygen levels, accumulation of this protein in the lungs may affect production of ribosomal RNA, a key component of ribosomes. 

Jain’s team is now examining the precise molecular role of MYBBP1A during hyperoxia, including whether its response is protective or harmful. This work could set the stage for novel treatments that target the MYBBP1A protein or associated molecules in ways that counter the bad effects of hyperoxia—similar to widespread research efforts targeting HIF proteins in low-oxygen conditions.

First-of-Its-Kind Dataset

The new study presents a first-of-its kind dataset of protein turnover rates in different tissues of mice exposed to different oxygen levels. The team hopes its results will inspire other researchers to further investigate the effects of too much or too little oxygen on the body, which could transform the way we treat disease.

About the Study

The paper “In Vivo Protein Turnover Rates in Varying Oxygen Tensions Nominate MYBBP1A as a Novel Mediator of the Hyperoxia Response” was published in the journal Science Advances on December 8, 2023.

In addition to Jain and Chen, other authors of the study are: Augustinus Haribowo, Alan Baik, Andrea Fossati, Erica Stevenson, Michela Traglia, Alexander Pico, and Danielle Swaney of Gladstone; Yiwen Chen and Daniel Jarosz of Stanford University; Nabora Reyes, Tien Peng, Michael Matthay, and Abigail Buchwalter of UC San Francisco; and Sina Ghaemmaghami of the University of Rochester

This work was supported by the American Heart Association, the California Institute for Regenerative Medicine, the National Institutes of Health (T32-HL007731, NIH DP5 DP5OD026398), the Chan Zuckerberg Biohub, the Sarnoff Cardiovascular Research Foundation, the UCSF Program for Breakthrough Biomedical Research, the Tobacco-Related Disease Research Program, and a gift from Dave Wentz.

About Gladstone Institutes

Gladstone Institutes is an independent, nonprofit life science research organization that uses visionary science and technology to overcome disease. Established in 1979, it is located in the epicenter of biomedical and technological innovation, in the Mission Bay neighborhood of San Francisco. Gladstone has created a research model that disrupts how science is done, funds big ideas, and attracts the brightest minds.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adj4884 

ARTICLE TITLE

In Vivo Protein Turnover Rates in Varying Oxygen Tensions Nominate MYBBP1A as a Mediator of the Hyperoxia Response

ARTICLE PUBLICATION DATE

8-Dec-2023

Reducing oxygen levels for children in intensive care will save lives

Peer-Reviewed Publication

UNIVERSITY COLLEGE LONDON

Reducing oxygen levels in critically ill children on mechanical ventilators in intensive care could save tens of young lives each year, finds a new study led by researchers at UCL and Great Ormond Street Hospital.

The study, funded by the National Institute for Health and Care Research and published in The Lancet, also found that lower levels of oxygen would reduce the number of days children spent on machines supporting organs, saving the NHS £20million every year.

Lead author, Professor Mark Peters (UCL Great Ormond Street Institute of Child Health and Consultant Paediatric Intensivist at GOSH), said: “Giving the minimum safe dose of anything in intensive care appears to generate the best outcomes, so we wanted to test this approach with oxygen. We found a small benefit of lower oxygen targets that is unlikely to have been due to chance. But because so many children are treated with oxygen, this has the potential to improve outcomes and reduce healthcare costs in the UK and around the world.

“This could have particular implications in countries where oxygen is a scare resource, or in situations as we have seen in recent years, where health needs change, and oxygen demand quickly peaks.”

In the UK, around 20,000 children are admitted to intensive care each year and roughly 75% will receive additional oxygen through a ventilator.

Oxygen is one of the most common treatments used in emergency situations. Doctors and nurses adjust oxygen treatment based on how much oxygen their patient has in their blood. While very low oxygen levels are harmful, current research shows that slightly lower than normal levels may be the best target for very ill people.

The Oxy-PICU study is the largest randomised controlled trial ever conducted in paediatric intensive care units (PICUs). It was led by researchers from UCL and Great Ormond Street Hospital (GOSH), the Intensive Care National Audit & Research Centre (ICNARC) and the Paediatric Critical Care Society Study Group (PCCS-SG).

The researchers recruited 2,040 children from 15 NHS PICUs across England and Scotland. Each of the children required a mechanical ventilator and extra oxygen on admission to the PICU.

The children, who ranged from newborn up to 16 years, were randomly allocated to one of two groups, either receiving oxygen to the standard target level (saturation “SpO2” > 94%), or a reduced oxygen target (SpO2 88-92%). The percentages refer to the proportion of the oxygen-carrying capacity of the blood that is being used.

The researchers found that the children who received the lower level of oxygen were 6% more likely to have a better outcome, either in terms of survival or the number of days spent on machines supporting their organs.

The researchers anticipate that if the approach was scaled up across the NHS, it could save 50 lives, 6,000 ICU bed days and £20million annually in the UK alone.

The Oxy-PICU study is funded by the NIHR’s Health Technology Assessment programme and supported by the NIHR’s Biomedical Research Centres at GOSH and UCLH.

Lauran O’Neill, Senior Critical Care Nurse at GOSH, said: “This is a major milestone study, which was nurse-led, with research taking place at the bedside as part of normal clinical care. It’s a great example of a research-hospital vision as every child admitted to ICU was screened for inclusion into the study.”

Professor Marian Knight, Scientific Director for NIHR Infrastructure, said: “The main purpose of all NIHR health and care research is to save or improve lives in some way, whether by questioning what we currently do or introducing new practice.

“This landmark nurse-led study has challenged the accepted practice for providing oxygen to children in intensive care in a way that could have a global impact. We are proud to have supported Professor Peters and his team through both our Health Technology Assessment programme, our Biomedical Research Centre at GOSH, and with our remarkable NIHR research nursing staff.”

Dilly and Noah’s story

When two-year-old Noah Karunananthan was diagnosed with leukaemia in May 2022 after a trip to A&E at Hillingdon Hospital, his family were devastated. Noah lives with his mum Dilly, dad Sabe and twin sister Naima in Hillingdon, West London. In order to give him the medication he urgently needed, the doctors had to sedate him, and he was quickly transported for treatment at Great Ormond Street Hospital (GOSH).

Mum Dilly says: “We were told Noah had blood cancer but we didn’t know what kind it was - it was really overwhelming. But the team came in and looked after him, they told us everything they were going to do, every step of the way and he had 1 to 1 care which I thought was amazing.”

Noah was in the ICU for around 4 days to support his organs while he received care. While there, his parents consented to him taking part in the Oxy-PICU trial as part of his recovery journey. He was later transferred to the oncology ward.

Dilly said: “I was so stunned when we got to the ICU, it was like a spaceship. I was in awe of all the machines, in shock really, and exhausted as it was the middle of the night.

“He was started on the Oxy-PICU trial before the team took us there in the ambulance. He had the new treatment of lower oxygen saturation targets.

“Noah had a brain biopsy to extract a suspected fungal infection – this scared the hell out of us. What was amazing was how he recovered. For three months he’d had almost no facial expressions – we hadn’t seen him smile. But then his daily Occupational Therapist Mary came one day and you could see him try to smile at her toys. After that session we could see him slowly getting better.

“This September, we signed up to nursery and we were worried Noah may not be able to do a full day but he’s thriving there! This is the first time we have been separated for longer periods and I can see that he loves learning and exploring.

“If Noah, or we as a family, can help children, parents and families through research we are happy to. He was one of the first people to try many of the research projects we have signed up to and it makes us proud that Noah has been able to help give some answers that may have helped him and could now help someone else and it’s all part of our journey.”

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JOURNAL

The Lancet

ARTICLE TITLE

Conservative versus liberal oxygenation targets in critically ill children (Oxy-PICU): a multiple centre, open, parallel group, randomised clinical trial

 

Female patients who speak Spanish, identify as Hispanic or experience food and housing insecurity at increased risk for depression, anxiety during radiation treatment

Peer-Reviewed Publication

BOSTON UNIVERSITY SCHOOL OF MEDICINE

(Boston)—Depression and anxiety among people living with a cancer diagnosis is a growing clinical and research priority. However, the prevalence of mood disorders in those living with cancer varies due to a multitude of variables such as stage and type of cancer, treatment, age, race and ethnicity.

 

A new study by researchers at Boston University Chobanian & Avedisian School of Medicine has found that Spanish-speaking patients undergoing radiotherapy for breast cancer experienced higher distress levels at baseline compared to English-speakers and that this distress increased over the course of treatment in contrast to English-speakers' distress, which decreased over time. Additionally, those who identified their race as “other” and ethnicity as Hispanic similarly reported an increase in distress throughout treatment.

 

“Given that breast cancer remains the most common type of cancer worldwide, its impact on mental health continues to be highly researched as it can hinder treatment, recovery and quality of life. However, Black and Hispanic patients which comprise about 29% of the U.S. population, have been historically understudied in cancer research,” said corresponding author Corina Beiner, a fourth-year medical student at the school.

 

To better understand the changes in levels of depression and anxiety, the researchers surveyed English and Spanish-speaking females, age 18 or older, before and after they underwent radiation therapy treatment for breast cancer. Sociodemographic characteristics including race, ethnicity, marital status, education level, longest residency location, religion, housing and food insecurity were also collected. The survey ended with a standardized questionnaire to assess for depression and anxiety and the score was used as a marker of psychological distress.

 

Prior to treatment, Spanish-speakers had a baseline distress level higher than English-speakers. Overall, participants showed a decreased level of distress post-treatment, however, when analyzed by language, English-speakers had decreased distress while Spanish-speakers reported an increased level of distress. Once sociodemographic factors were adjusted by language, Spanish-speakers reported a significantly higher level of housing and food insecurity, which may explain their higher levels of distress. “For this reason, we believe it would be beneficial to screen all Spanish-speaking patients for risk factors that may increase their distress throughout treatment,” added Beiner.

 

According to the researchers, exploring the varying levels of depression and anxiety faced by these patients is warranted, particularly given that a diagnosis of mood disorders is linked to poorer survival outcomes. Prior knowledge that certain groups at a baseline may be experiencing more distress, can help guide initial changes to mediate these differences.

 

“Additionally, regarding radiation therapy, knowing that a portion of our patients are at an increased risk of developing higher distress levels throughout a course of treatment can drive interventions to combat this,” said senior author Ariel E. Hirsch, MD, professor of radiation oncology.

 

 

While further investigation is necessary to elucidate other reasons for this increase in distress throughout treatment, the researchers believe these results indicate an area for clinical need. “Patients at risk for increased depression or anxiety or increased distress throughout treatment may benefit from interventions prior to and throughout radiation therapy, such as preferred language education sessions or informational calls throughout treatment,” added Hirsch. 

 

These findings appear online in the International Journal of Radiation Oncology, Biology and Physics.

 

Funding was provided by the ASCO Conquer Cancer Medical Student Rotation for Underrepresented Populations Award, which provides financial support for U.S. medical students from populations underrepresented in medicine who are interested in oncology as a career to experience a minimum 4-week clinical or clinical research rotation.

 

 

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METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

: Depression and Anxiety Among English and Spanish-Speaking Patients with Breast Cancer Receiving Radiation Therapy

ARTICLE PUBLICATION DATE

7-Dec-2023