Logging and climate change threaten montane birds

Peer-Reviewed Publication

INDIAN INSTITUTE OF SCIENCE (IISC)

 

IMAGE: 

EAGLENEST WILDLIFE SANCTUARY 

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CREDIT: GLOBAL CHANGE LAB, CES

Researchers at the Indian Institute of Science (IISc) have studied the effects of forest logging and climate change on bird communities in tropical mountains, by examining over 10 years of data.  

In a study published in Global Ecology and Conservation, the team used mist netting and bird ringing data to answer how the composition of the mid-elevation Eastern Himalayan understorey bird community changed in primary (undisturbed) forests as well as in logged forests.  

Tropical montane forests are unique ecosystems that can start at about 150-200 m and reach up to 3,500 m high up on mountains around the world. They are critical centres of biodiversity. “In tropical mountains, each species has a particular niche where it is found. This restriction creates much more diversity in a small space,” explains Ritobroto Chanda, former Project Associate at the Centre for Ecological Sciences (CES), IISc, and corresponding author of the study.  

Forest loss and climate change present major threats to these ecosystems. “Birds – and indeed much of the flora and fauna – of tropical mountain ranges are extremely temperature-sensitive and are responding to global heating rapidly. Also, most of the world’s terrestrial biodiversity is concentrated in tropical mountains,” says Umesh Srinivasan, Assistant Professor at CES and another author. However, very few studies have explored the joint influence of these threats.  

The team found that many bird species have started shifting to higher elevations due to rising temperatures. Logged forests have higher average temperatures and lower humidity than primary forests, thus hastening the transition. Additionally, birds that are smaller in size seem to colonise these logged forests better because they can tolerate higher temperatures, while the density of larger bird species appears to be increasing in the primary forests.  

The team collected data from the Eaglenest Wildlife Sanctuary, Arunachal Pradesh, situated in the biodiversity hotspot of Eastern Himalayas and home to over 500 bird species. The area saw intensive logging until 2002, and the logged regions have major differences compared to intact forests, making them ideal for the study. The support of the local communities is also critical to carry out such studies, Chanda says. “You have to stay in a wildlife sanctuary with no paved roads, no electricity, and no place to stay as such. We take our food with us, cook on a daily basis, make a makeshift camp and move around, and without the people’s support, it’s really not possible to continue this for a long time,” he emphasises. 

Each day, after setting up the mist nets, the team checked them every 20-30 minutes, weighed and labelled the birds, and released them immediately. Out of the 6,189 captured individuals from 130 species, the final analysis included 4,801 understorey insectivores – insect-eating birds that live under the canopy of large trees – belonging to about 61 species. The researchers focused on these birds because their niches are well defined and abundant data from the mist nets is available for them. Rare species were left out of the study to avoid skewed results.  

What the team found was that logging can lead to the loss of large-bodied, old growth-dependent species, and decrease the overall biodiversity. Understorey insectivores, which are often found only in specific niches, are negatively influenced by logging and show steep declines in numbers. Logged forests also have lower densities of foliage-dwelling insects, reducing the resource availability for the birds. Since large species have higher energy requirements, this disproportionately reduces the abundance of large species.  

The study highlights the need to safeguard primary forests in order to mitigate the effects of climate change. “Logging managers should ensure that undisturbed forests across large elevational gradients are protected,” says Srinivasan. He explains that this will allow species to shift their ranges upwards in response to climate change and maintain survival. “If species encounter degraded forest while they shift upwards, certain species will most likely go locally extinct.” 

A Chestnut-headed Tesia being ringed

CREDIT

Global Change Lab, CES

Yellow-throated fulvetta with metal and colour rings 

CREDIT

Micah Rai

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JOURNAL

Global Ecology and Conservation

DOI

10.1016/j.gecco.2023.e02664 

ARTICLE TITLE

Bird communities in a selectively logged tropical montane forest are dominated by small, low-elevation species

 

Study shows weed makes workouts more fun, but it's no performance enhancer

8 in 10 cannabis users report combining marijuana with exercise, saying it boosts motivation and mood, eases pain

Peer-Reviewed Publication

UNIVERSITY OF COLORADO AT BOULDER

 

IMAGE: 

BOULDER-BASED ULTRARUNNER HEATHER MASHHOODI RUNS ON THE TREADMILL  IN 2021 AS PART OF A STUDY EXPLORING HOW CANNABIS INFLUENCES EXERCISE.  FIRST AUTHOR LAUREL GIBSON, LEFT, TAKES NOTES. STUDY PARTICIPANTS USED CANNABIS ON THEIR OWN AT HOME BEFORE BEING PICKED UP AND DRIVEN TO THE LAB FOR TESTING. CREDIT: PATRICK CAMPBELL/CU BOULDER

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CREDIT: PATRICK CAMPBELL/CU BOULDER

A bit of weed before a workout can boost motivation and make exercise more enjoyable. But if performance is the goal, it may be best to skip that joint.

That’s the takeaway of the first ever study to examine how legal, commercially available cannabis shapes how exercise feels.

The study of 42 runners, published Dec. 26 in the journal Sports Medicine, comes almost exactly 10 years after Colorado became the first state to commence legal sales of recreational marijuana, at a time when cannabis-users increasingly report mixing it with workouts.

“The bottom-line finding is that cannabis before exercise seems to increase positive mood and enjoyment during exercise, whether you use THC or CBD. But THC products specifically may make exercise feel more effortful,” said first author Laurel Gibson, a research fellow with the University of Colorado Boulder's Center for Health and Addiction: Neuroscience, Genes and Environment (CU Change).

The findings, and previous research by the team, seem to defy long-held stereotypes that associate cannabis with “couch-lock” and instead raise an intriguing question: Could the plant play a role in getting people moving?

“We have an epidemic of sedentary lifestyle in this country, and we need new tools to try to get people to move their bodies in ways that are enjoyable,” said senior author Angela Bryan, a professor of psychology and neuroscience and co-director of CU Change. “If cannabis is one of those tools, we need to explore it, keeping in mind both the harms and the benefits.”

‘A first-of-a-kind study’

In one previous survey of cannabis users, Bryan’s research group found that a whopping 80% had used before or shortly after exercise. Yet very little research has been done at the intersection of the two.

For the study, Bryan and Gibson recruited 42 Boulder-area volunteers who already run while using cannabis.

After a baseline session, in which the researchers took fitness measurements and survey data, they assigned participants to go to a dispensary and pick up either a designated flower strain that contained mostly cannabidiol (CBD) or a Tetrahydrocannabinol (THC) -dominant strain.

THC and CBD are active ingredients in cannabis, with THC known to be more intoxicating.

On one follow-up visit, volunteers ran on a treadmill at a moderate pace for 30 minutes, answering questions periodically to assess how motivated they felt, how much they were enjoying themselves, how hard the workout felt, how quickly time seemed to pass and their pain levels.

On another visit, they repeated this test after using cannabis.

Federal law prohibits the possession or distribution of marijuana on college campuses, so the runners used it at home, before being picked up in a mobile laboratory, a.k.a the ‘CannaVan,’ and brought to the lab.

The runners also wore a safety belt on the treadmill.

‘Not a performance-enhancing drug’

Across the board, participants reported greater enjoyment and more intense euphoria, or ‘runner’s high,’ when exercising after using cannabis.

Surpisingly, this heightened mood was even greater in the CBD group than in the THC group, suggesting athletes may be able to get some of the benefits to mood without the impairment that can come with THC.

Participants in the THC group also reported that the same intensity of running felt significantly harder during the cannabis run than the sober run.

This may be because THC increases heart rate, Bryan said.

In a previous study conducted remotely, she and Gibson found that while runners felt more enjoyment under the influence of cannabis, they ran 31 seconds per mile slower.

“It is pretty clear from our research that cannabis is not a performance enhancing drug,” said Bryan.

Notably, numerous elite athletes—including U.S. sprinter Sha’Carri Richardson— have been prohibited from competing in recent years after testing positive for cannabis.

An NCAA committee recently recommended that it be removed from its list of banned substances.

Boulder-based ultrarunner Heather Mashhoodi runs on the treadmill  in 2021 as part of a study exploring how cannabis influences exercise.  First author Laurel Gibson takes notes in the background. Study participants used cannabis on their own at home before being picked up and driven to the lab for testing. Credit: Patrick Campbell/CU Boulder

CREDIT

Patrick Campbell/CU Boulder

A different kind of runner’s high

Why does cannabis make exercise feel better?

While natural, pain-killing endorphins have long been credited with the famous “runner’s high,” newer research suggests that this is a myth: Instead, naturally produced brain chemicals known as endogenous cannabinoids are likely at play, kicking in after an extended period of exercise to produce euphoria and alertness.

“The reality is, some people will never experience the runner’s high,” Gibson notes.

By consuming CBD or THC, cannabinoids which bind to the same receptors as the cannabinoids our brain makes naturally, athletes might be able to tap into that high with a shorter workout or enhance it during a long one, she said.

Athletes considering using cannabis should be aware that it can come with risks — including dizziness and loss of balance— and it’s not for everyone.

For someone gunning for a fast 5k or marathon PR, it doesn’t really make sense to use beforehand, Bryan said.

But for an ultrarunner just trying to get through the grind of a double-digit training run, it might.

As a public health researcher, Bryan is most interested in how it could potentially impact those who struggle to exercise at all, either because they can’t get motivated, it hurts, or they just don’t like it.

“Is there a world where taking a low-dose gummie before they go for that walk might help? It’s too early to make broad recommendations but it’s worth exploring,” she said.

 

BOX

Why do people mix weed and workouts?

When researchers asked study participants, here’s what they said:

 

90.5% It increases enjoyment

69% It decreases pain

59.5% It increases focus

57.1% It increases motivation

45.2% It makes time go by faster

28.6% It improves performance

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JOURNAL

Sports Medicine

DOI

10.1007/s40279-023-01980-4 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Acute Effects of Ad Libitum Use of Commercially Available Cannabis Products on the Subjective Experience of Aerobic Exercise: A Crossover Study

Psychoactive drug ibogaine effectively treats traumatic brain injury in special ops military vets

Stanford researchers find that ibogaine, a plant-based psychoactive compound, safely led to improvements in depression, anxiety and functioning among veterans with traumatic brain injuries.

Peer-Reviewed Publication

STANFORD MEDICINE

For military veterans, many of the deepest wounds of war are invisible: Traumatic brain injuries resulting from head trauma or blast explosions are a leading cause of post-traumatic stress disorder, anxiety, depression and suicide among veterans. Few treatments have been effective at diminishing the long-term effects of TBI, leaving many veterans feeling hopeless. 

Now, Stanford researchers have discovered that the plant-based psychoactive drug ibogaine, when combined with magnesium to protect the heart, safely and effectively reduces PTSD, anxiety and depression and improves functioning in veterans with TBI. Their new study, to be published online Jan. 5 in Nature Medicine, includes detailed data on 30 veterans of U.S. special forces.

“No other drug has ever been able to alleviate the functional and neuropsychiatric symptoms of traumatic brain injury,” said Nolan Williams, MD, an associate professor of psychiatry and behavioral sciences. “The results are dramatic, and we intend to study this compound further.”

Alternative options

Traumatic brain injury is defined as a disruption in the normal functioning of the brain resulting from external forces — such as explosions, vehicle collisions or other bodily impacts. The trauma associated with TBI can lead to changes in the function and/or structure of the brain, which, in turn, contributes to neuropsychiatric symptoms.

Hundreds of thousands of troops serving in Afghanistan and Iraq have sustained TBIs in recent decades, and these injuries are suspected of playing a role in the high rates of depression and suicide seen among military veterans. With mainstream treatment options not fully effective for some veterans, researchers have sought therapeutic alternatives.

Ibogaine is a naturally occurring compound found in the roots of the African shrub iboga, and it has been used for centuries in spiritual and healing ceremonies. More recently, it has gained interest from the medical and scientific communities for its potential to treat opioid and cocaine addiction, and research has suggested that it increases signaling of several important molecules within the brain, some of which have been linked to drug addiction and depression. Since 1970 ibogaine has been designated as a Schedule I drug, preventing its use within the U.S., but clinics in both Canada and Mexico offer legal ibogaine treatments.

“There were a handful of veterans who had gone to this clinic in Mexico and were reporting anecdotally that they had great improvements in all kinds of areas of their lives after taking ibogaine,” Williams said. “Our goal was to characterize those improvements with structured clinical and neurobiological assessments.”

Capturing ‘before and after’

Williams and his colleagues at Stanford teamed up with VETS, Inc., a foundation that helps facilitate psychedelic-assisted therapies for veterans. With support from VETS, 30 special operations veterans with a history of TBI and repeated blast exposures, almost all of whom were experiencing clinically severe psychiatric symptoms and functional disabilities, had independently scheduled themselves for treatment with magnesium and ibogaine at a clinic in Mexico.

Before the treatment, Stanford researchers gauged the participants’ levels of PTSD, anxiety, depression and functioning based on a combination of self-reported questionnaires and clinician-administered assessments. Participants then traveled to a clinic in Mexico run by Ambio Life Sciences, where under medical monitoring they received oral ibogaine along with magnesium to help prevent heart complications that have been associated with ibogaine. The veterans then returned to Stanford for post-treatment assessments.

“These men were incredibly intelligent, high-performing individuals who experienced life-altering functional disability from TBI during their time in combat,” Williams said. “They were all willing to try most anything that they thought might help them get their lives back.”

At the beginning of the study, participants were experiencing clinically significant levels of disability as measured by the World Health Organization Disability Assessment Scale 2.0, which assesses disability in six functional domains, including cognition, mobility, self-care, getting along, life activities and community participation. In addition, 23 met the criteria for PTSD, 14 for an anxiety disorder and 15 for alcohol use disorder. In their lifetimes, 19 participants had been suicidal and seven had attempted suicide.

Life-changing results

On average, treatment with ibogaine immediately led to significant improvements in functioning, PTSD, depression and anxiety. Moreover, those effects persisted until at least one month after treatment — the endpoint of the study.

Before treatment, the veterans had an average disability rating of 30.2 on the disability assessment scale, equivalent to mild to moderate disability. One month after treatment, that rating improved to 5.1, indicating no disability. Similarly, one month after treatment participants experienced average reductions of 88% in PTSD symptoms, 87% in depression symptoms and 81% in anxiety symptoms relative to how they were before ibogaine treatment. Formal cognitive testing also revealed improvements in participants’ concentration, information processing, memory and impulsivity.

“I wasn’t willing to admit I was dealing with any TBI challenges. I just thought I’d had my bell rung a few times — until the day I forgot my wife’s name,” said Craig, a 52-year-old study participant from Colorado who served 27 years in the U.S. Navy. “Since [ibogaine treatment], my cognitive function has been fully restored. This has resulted in advancement at work and vastly improved my ability to talk to my children and wife.”

“Before the treatment, I was living life in a blizzard with zero visibility and a cold, hopeless, listless feeling,” said Sean, a 51-year-old veteran from Arizona with six combat deployments who participated in the study and says ibogaine saved his life. “After ibogaine, the storm lifted.”

Importantly, there were no serious side effects of ibogaine and no instances of the heart problems that have occasionally been linked to ibogaine. During treatment, veterans reported only typical symptoms such as headaches and nausea.

Lessons for PTSD, depression and anxiety

Williams and his team are planning further analysis of additional data collected on the veterans but not included in the current study, including brain scans that could help reveal how ibogaine led to improvements in cognition. They also hope to launch future studies to further understand how the drug might be used to treat TBI.

However, they think ibogaine’s drastic effects on TBI also suggest that it holds broader therapeutic potential for other neuropsychiatric conditions. “In addition to treating TBI, I think this may emerge as a broader neuro-rehab drug,” Williams said. “I think it targets a whole host of different brain areas and can help us better understand how to treat other forms of PTSD, anxiety and depression that aren’t necessarily linked to TBI.”

The study was independently funded by philanthropic gifts from Steve and Genevieve Jurvetson and another anonymous donor. Stanford received no funding from VETS, Inc. or Ambio.

# # #

About Stanford Medicine

Stanford Medicine is an integrated academic health system comprising the Stanford School of Medicine and adult and pediatric health care delivery systems. Together, they harness the full potential of biomedicine through collaborative research, education and clinical care for patients. For more information, please visit med.stanford.edu.

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JOURNAL

Nature Medicine

DOI

10.1038/s41591-023-02705-w 

METHOD OF RESEARCH

Randomized controlled/clinical trial

SUBJECT OF RESEARCH

People

ARTICLE TITLE

agnesium–ibogaine therapy in veterans with traumatic brain injuries'

ARTICLE PUBLICATION DATE

5-Jan-2024

 

The evolution of photosynthesis better documented thanks to the discovery of the oldest thylakoids in fossil cyanobacteria

This major discovery by researchers from the Early Life Traces & Evolution Laboratory at ULiège offers a new approach to decipher the early diversification of life and for clarifying the role of cyanobacteria in the Great Oxygenation of the Earth

Peer-Reviewed Publication

UNIVERSITY OF LIÈGE

 

IMAGE: 

IMAGE OF NAVIFUSA MAJENSIS, A MICROFOSSIL FROM THE MCDERMOTT FORMATION IN AUSTRALIA. THIS 1.75 BILLION-YEAR-OLD MICROFOSSIL CONTAINS THYLAKOIDS, WHICH IDENTIFY IT AS A CYANOBACTERIUM. 

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CREDIT: EMMANUELLE JAVAUX

Researchers at the University of Liège (ULiège) have identified microstructures in fossil cells that are 1.75 billion years old. These structures, called thylakoid membranes, are the oldest ever discovered. They push back the fossil record of thylakoids by 1.2 billion years and provide new information on the evolution of cyanobacteria which played a crucial role in the accumulation of oxygen on the early Earth. This major discovery is presented in the journal Nature.

 

Catherine Demoulin, Yannick Lara, Alexandre Lambion and Emmanuelle Javaux from the Early Life Traces & Evolution laboratory of the Astrobiology Research Unit at ULiège examined enigmatic microfossils called Navifusa majensis (N.majensis) in shales from the McDermott Formation in Australia, which are 1.75 billion years old, and in 1 billion year old formations of DRCongo and arctic Canada. Ultrastructural analyses in fossil cells from 2 formations (Australia, Canada) revealed the presence of internal membranes with an arrangement, fine structure and dimensions permitting to interpret them unambiguously as thylakoid membranes, where oxygenic photosynthesis occurs. These observations permitted to identify N majensis as a fossil cyanobacterium.

 

This discovery puts into perspective the role of cyanobacteria with thylakoid membranes in early Earth oxygenation. They played an important role in the early evolution of life and were active during the Great Oxygenation Event (GOE), around 2.4 billion years ago. However, the chronology of the origins of oxygenic photosynthesis and the type of cyanobacteria (protocyanobacteria? With or without thylakoids?) involved remain debated, and the ULiège researchers' discovery offers a new approach to clarify these issues.

 

 

"The oldest known fossil thylakoids date back to around 550 million years. The ones we have identified therefore extend the fossil record by 1.2 billion years", explains Professor Emmanuelle Javaux, paleobiologist and astrobiologist, director of the Early Life Traces & Evolution laboratory at ULiège.

 

"The discovery of preserved thylakoids in N. majensis provides direct evidence of a minimum age of around 1.75 billion years for the divergence between cyanobacteria with thylakoids and those without."

 

But the ULiège team's discovery raises the possibility to discover thylakoids in even older cyanobacterial fossils, and to test the hypothesis that the emergence of thylakoids may have played a major role in the great oxygenation of the early Earth around 2.4 billion years ago. This approach also permits to examine the role of dioxygen in the evolution of complex life (eucaryote) on our planet, including the origin and early diversification of algae that host chloroplasts derived from cyanobacteria.

"Microscopic life is beautiful, the most diverse and abundant form of life on Earth since the origin of life. Studying its fossil record using new approaches will enable us to understand how life evolved over at least 3.5 billion years. Some of this research also tells us how to search for traces of life beyond Earth!", concludes Emmanuelle Javaux.

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JOURNAL

Nature

DOI

10.1038/s41586-023-06896-7 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Oldest thylakoids in fossil cells directly evidence oxygenic photosynthesis

ARTICLE PUBLICATION DATE

3-Jan-2024

 

Ancestors of primates lived in pairs

Peer-Reviewed Publication

CNRS

A study carried out by CNRS1 scientists working with an international team has revealed that around 70 million years ago, when dinosaurs existed, the ancestors of primates most commonly lived in pairs. Only 15% of them opted for a solitary lifestyle. This discovery — that our ancestors adopted variable forms of social organization — challenges the hitherto commonly accepted hypothesis that at the time of dinosaurs, the ancestors of primates lived alone, and that pair living evolved much later. Most likely, pair living offered significant benefits, such as easier reproduction and reduced costs of thermoregulation by huddling in pairs.

While several studies have already been conducted on the social organisation of primate ancestors, this is the first one to use only currently available field observations. By studying 498 populations from 223 species, the research team has built the most accurate database of primates to date. The information obtained was then coupled with innovative statistical analysis. This research, published in the Vol. 121, no.1 issue of PNAS, paves the way for a better understanding of the social evolution of the human species.

1 — Based at the Hubert Curien Pluridisciplinary Institute (IPHC) (CNRS/Université de Strasbourg).

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2215401120 

ARTICLE TITLE

Primate social organization evolved from a flexible pair-living ancestor

 

NASA/JAXA XRISM mission reveals its first look at X-ray cosmos

Business Announcement

NASA/GODDARD SPACE FLIGHT CENTER

 

IMAGE: 

XRISM’S RESOLVE INSTRUMENT CAPTURED DATA FROM SUPERNOVA REMNANT N132D IN THE LARGE MAGELLANIC CLOUD TO CREATE THE MOST DETAILED X-RAY SPECTRUM OF THE OBJECT EVER MADE. THE SPECTRUM REVEALS PEAKS ASSOCIATED WITH SILICON, SULFUR, ARGON, CALCIUM, AND IRON. INSET AT RIGHT IS AN IMAGE OF N132D CAPTURED BY XRISM’S XTEND INSTRUMENT.

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CREDIT: JAXA/NASA/XRISM RESOLVE AND XTEND

The Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) observatory has released a first look at the unprecedented data it will collect when science operations begin later this year.

The satellite’s science team released a snapshot of a cluster of hundreds of galaxies and a spectrum of stellar wreckage in a neighboring galaxy, which gives scientists a detailed look at its chemical makeup.

“XRISM will provide the international science community with a new glimpse of the hidden X-ray sky,” said Richard Kelley, the U.S. principal investigator for XRISM at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’ll not only see X-ray images of these sources, but also study their compositions, motions, and physical states.”

XRISM (pronounced “crism”) is led by JAXA (Japan Aerospace Exploration Agency) in collaboration with NASA, along with contributions from ESA (European Space Agency). It launched on Sept. 6, 2023.

It’s designed to detect X-rays with energies up to 12,000 electron volts and will study the universe’s hottest regions, largest structures, and objects with the strongest gravity. For comparison, the energy of visible light is 2 to 3 electron volts.

The mission has two instruments, Resolve and Xtend, each at the focus of an X-ray Mirror Assembly designed and built at Goddard.

Resolve is a microcalorimeter spectrometer developed by NASA and JAXA. It operates at just a fraction of a degree above absolute zero inside a refrigerator-sized container of liquid helium. 

When an X-ray hits Resolve’s 6-by-6-pixel detector, it warms the device by an amount related to its energy. By measuring each individual X-ray’s energy, the instrument provides information previously unavailable about the source.

The mission team used Resolve to study N132D, a supernova remnant and one of the brightest X-ray sources in the Large Magellanic Cloud, a dwarf galaxy around 160,000 light-years away in the southern constellation Dorado. The expanding wreckage is estimated to be about 3,000 years old and was created when a star roughly 15 times the Sun’s mass ran out of fuel, collapsed, and exploded.

The Resolve spectrum shows peaks associated with silicon, sulfur, calcium, argon, and iron. This is the most detailed X-ray spectrum of the object ever obtained and demonstrates the incredible science the mission will do when regular operations begin later in 2024.

“These elements were forged in the original star and then blasted away when it exploded as a supernova,” said Brian Williams, NASA’s XRISM project scientist at Goddard. “Resolve will allow us to see the shapes of these lines in a way never possible before, letting us determine not only the abundances of the various elements present, but also their temperatures, densities, and directions of motion at unprecedented levels of precision. From there, we can piece together information about the original star and the explosion.”

XRISM’s second instrument, Xtend, is an X-ray imager developed by JAXA. It gives XRISM a large field of view, allowing it to observe an area about 60% larger than the average apparent size of the full moon.

Xtend captured an X-ray image of Abell 2319, a rich galaxy cluster about 770 million light-years away in the northern constellation Cygnus. It’s the fifth brightest X-ray cluster in the sky and is currently undergoing a major merger event.

The cluster is 3 million light-years across and highlights Xtend’s wide field of view.

“Even before the end of the commissioning process, Resolve is already exceeding our expectations,” said Lillian Reichenthal, NASA’s XRISM project manager at Goddard. “Our goal was to achieve a spectral resolution of 7 electron volts with the instrument, but now that it’s in orbit, we’re achieving 5. What that means is we’ll get even more detailed chemical maps with each spectrum XRISM captures.”

Resolve is performing exceptionally and already conducting exciting science despite an issue with the aperture door covering its detector. The door, designed to protect the detector before launch, has not opened as planned after several attempts. The door blocks lower-energy X-rays, effectively cutting the mission off at 1,700 electron volts compared to the planned 300. The XRISM team will continue to explore the anomaly and is investigating different approaches to opening the door. The Xtend instrument is unaffected.

NASA’s XRISM General Observer Facility, hosted at Goddard, is accepting proposals for observations from members of U.S. and Canadian institutions through Thursday, April 4. Cycle 1 of XRISM General Observer investigations will begin in the summer of 2024.

XRISM is a collaborative mission between JAXA and NASA, with participation by ESA. NASA’s contribution includes science participation from the Canadian Space Agency.

Mysterious missing component in the clouds of Venus revealed

Peer-Reviewed Publication

UNIVERSITY OF CAMBRIDGE

 

IMAGE: 

MULTIPLE VIEWS OF VENUS' HIGH-LEVEL CLOUDS. CREDIT: NASA/JPL

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CREDIT: NASA/JPL

What are the clouds of Venus made of? Scientists know it’s mainly made of sulfuric acid droplets, with some water, chlorine, and iron. Their concentrations vary with height in the thick and hostile Venusian atmosphere. But until now they have been unable to identify the missing component that would explain the clouds’ patches and streaks, only visible in the UV range.

In a new study published in Science Advances, researchers from the University of Cambridge synthesised iron-bearing sulfate minerals that are stable under the harsh chemical conditions in the Venusian clouds. Spectroscopic analysis revealed that a combination of two minerals, rhomboclase and acid ferric sulfate, can explain the mysterious UV absorption feature on our neighbouring planet.

“The only available data for the composition of the clouds were collected by probes and revealed strange properties of the clouds that so far we have been unable to fully explain,” said Paul Rimmer from the Cavendish Laboratory and co-author of the study. “In particular, when examined under UV light, the Venusian clouds featured a specific UV absorption pattern. What elements, compounds, or minerals are responsible for such observation?”

Formulated on the basis of Venusian atmospheric chemistry, the team synthesized several iron-bearing sulfate minerals in an aqueous geochemistry laboratory in the Department of Earth Sciences. By suspending the synthesized materials in varying concentrations of sulfuric acid and monitor the chemical and mineralogical changes, the team narrowed down the candidate minerals to rhomboclase and acid ferric sulfate, of which the spectroscopic features were examined under light sources specifically designed to mimic the spectrum of solar flares (Paul Rimmer and Samantha Thompson's FlareLab at the Cavendish Laboratory).

A photochemistry lab at Harvard collaborated in the research by providing measurements of the UV absorbance patterns of ferric iron under extreme acidic conditions, in an attempt to mimic the even more extreme Venusian clouds. The scientists are part of the newly established Origins Federation, which promotes such collaborative projects.

“The patterns and level of absorption shown by the combination of these two mineral phases are consistent with the dark UV-patches observed in Venusian clouds,” said co-author Clancy Zhijian Jiang, from the Department of Earth Sciences, Cambridge. “These targeted experiments revealed the intricate chemical network within the atmosphere, and shed light on the elemental cycling on the Venusian surface.”

“Venus is our nearest neighbour, but it remains a mystery,” said Rimmer. “We will have a chance to learn much more about this planet in the coming years with future NASA and ESA missions set to explore its atmosphere, clouds and surface. This study prepares the grounds for these future explorations.”

The research was supported by the Simons Foundation, and the Origins Federation.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adg8826 

ARTICLE TITLE

Iron-sulfur chemistry can explain the ultraviolet absorber in the clouds of Venus

ARTICLE PUBLICATION DATE

3-Jan-2024