Peter Brannen has an uncompromising opinion about carbon dioxide. It is the most important compound that has ever existed, he insists. Forget water or DNA or proteins or other life-enhancing materials. These are chemical parvenus compared with CO2, the miracle molecule, which he believes has shaped the course of evolution and which will soon determine the fate of Homo sapiens.
“C02 is the very stuff of life,” the US science journalist argues ; its behaviour on this planet “is what makes it Earthlike” . The gas is the permanent store on which all growing things depend and is the ultimate destiny of all flesh, he adds, borrowing a quote from Primo Levi.
Bigging up CO2 is certainly illustrative. Apart from highlighting its role in the creation of life, such a narrative reveals how the gas regulates the chemistry of our oceans and acts as the key control knob that governs Earth’s temperature. This last function is one of particular significance.
Carbon dioxide accounts for only 0.04% of the gases in our atmosphere, but that trace holds on to enough heat from the sun to provide our planet with a climatic stability that has continued for much of Earth’s history – with only a few dramatic exceptions.
One of these occurred around 600m years ago, when atmospheric CO2 reached such a low level that our world’s thermal insulation was denuded. Glaciers spread from the poles to the equator and ice covered the planet. This was Snowball Earth: “a glittering, dead, white orb” from which all life was very nearly extinguished, writes Brannen .
On other occasions, continent-wide eruptions of volcanic carbon dioxide produced the opposite effect and caused atmospheric levels of the gas to soar. Global temperatures surged and mass extinctions ensued.
These latter cataclysms have a particularly powerful resonance today because humanity – following in the wake of those ancient volcanoes – is now pumping carbon dioxide into the atmosphere in staggering amounts. We emit more than 41bn tonnes of this heat-retaining gas every year, such is our appetite for burning fossil fuels.
In fact, humans now make more CO2 than any other substance on Earth . It is our signature product and, as atmospheric levels rise, so the planet heats up. Deserts are spreading, ice caps are melting, sea levels are rising, coral reefs are dying and deadly heatwaves are increasingly frequent. An “overwhelming derangement of the carbon cycle is currently under way,” Brannen states early on in his story, a view that is later hardened to a pithier, more apposite warning about global warming. Basically, “ we’re in deep shit ”, he concludes.
In recent years, there have been many books on the climate catastrophe that we are inflicting on ourselves through the misuse of carbon dioxide. However, Brannen’s approach is unusual because of his focus on our long and intense relationship with the gas. Its presence and impact on the planet is not some recent phenomenon , he points out. It has always been around and has been a major player in Earthly affairs, for better or worse, since life first appeared .
‘An overwhelming derangement of the carbon cycle is under way.’ Basically, ‘we’re in deep shit’, Brannen says
At that time, around 4 b n years ago, carbon dioxide was a cause of global chemical disequilibrium. Seafloor vents had begun spewing alkaline liquids into oceans that had been made acid by CO2. It was a volatile mix. Then life appeared, not as an accident, but as a system that helped restore balance to the interplay of these chemicals – by removing the excess carbon from CO2. That carbon then became the stuff that would “ make up and energi se all life to this day ”, as Brannen puts it.
In other words, life was an almost inevitable outcome of the presence of carbon dioxide, and the fates of all living things and the gas have been intertwined ever since. We need to start appreciating our eons-old relationship with CO2, in short.
It is an intriguing argument, outlined by Brannen in unstinting, occasionally overwhelming detail – and in language that all too often verges on the ripe and florid. “Earth’s uneventful eternities midwifed the riotous pageant of animal life,” the reader is told . “Shimmering white ice sheets that once meekly coalesced at the poles raced to the equator … clasping crystalline hands over the entire Earth,” we learn elsewhere. Later, our world is described not simply as a rocky planet but as a “grain of sapphire in space”, while the jungles of the Carboniferous period are described as “throbbing” for no apparent reason.
This is not a bad book, it should be stressed, but it is overlong and overwritten . Its stylistic indulgences mar what is otherwise an insightful, unsettling analysis of how our species has developed its strange relationship with a single, primordial substance.
The Story of CO2 Is the Story of Everything: A Planetary Experiment by Peter Brannen is published by Allen Lane (£30). Order a copy from The Observer Shop for £27. Delivery charges may apply
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Kirsten Smith was 16 when a boy from school injected her with morphine, 18 when she and a date Googled how to crush up and inject themselves with oxycodone, and 19 when she first shot up heroin. Living in Knoxville, Tennessee and modelling herself on Pulp Fiction’s freewheeling Mia Wallace, Smith spent her days experimenting with alcohol, cannabis, ecstasy, mushrooms, LSD and benzodiazepines. She read Kurt Vonnegut and the Beats, and wrote poems on an actual typewriter while listening to the Velvet Underground. For Smith, as for thousands of Americans who came of age in the early 2000s, drug use was a seemingly harmless lifestyle choice.
That is, until she ran out of money. After Smith dropped out of high school and started regularly using heroin, she was caught stealing credit cards and chequebooks from a boyfriend’s wealthy parents, from a family friend at church and from her grandmother. On probation for two years, and forced by her parents into a month-long stay at an addiction treatment facility, Smith felt, for the first time, ashamed.
Returning to school was supposed to be Smith’s lifeline. She went to community college and got a job as a waiter at Charlie’s, a local restaurant chain. Then, in the summer of 2004, she met Brad Renfro, who had starred as a child actor in Hollywood films such as The Client and Sleepers. He introduced her to smoking crack cocaine and the best heroin she had ever known. After three months together, Smith began to wonder whether she would be a junkie for the rest of her life.
One day, standing in the living room of Renfro’s downtown boarding house, Smith watched him struggle to find a vein. Blood ran down his arm as he plugged in the dregs of his cocaine supply, a residue shot that Smith called a “low sad point in an addict’s life”. For her, Renfro had crossed a line into the shadowlands of compulsion. It was over between them. (Smith didn’t hear of Renfro again until he died of an overdose in 2008.)
While waiting on tables at Charlie’s, Smith met a young man named Michael, who had grown up in the same suburb as her. Michael was quiet and kept mostly to himself. His buzz cut and angular features contrasted with his sweet smile and blue eyes. The two clicked when Smith revealed that she had sent a fan letter to the author of Fight Club, Chuck Palahniuk, and had received a written response. Michael didn’t believe her until Smith brought the letter to work, dusty and charred by a house fire Smith had started when she was 15.
In 2005, Smith and Michael rented a one-bedroom apartment in an old building downtown. They also did drugs together, shoplifting to subsidise their lifestyle, which Smith described as a “romanticised junkiedom”. Through their network of white suburban addicts, Michael and Smith became hooked on expensive black tar heroin shipped in by a drug cartel that they referred to as “the Mexicans”. Despite their addictions, Smith and Michael maintained a stable, domestic existence. They wrote stories, paid their bills and owned two cats.
Later that year, Smith and Michael were both admitted to the University of Tennessee. This was Smith’s cue to get sober, but treatments for substance-use disorders and the torturous symptoms of withdrawal were limited. Relatively few medications were approved, and although behavioural and community-based treatments existed, when Smith, 23, tried to return to rehab, her stepfather’s insurance company rebuffed her.
The couple attended meetings at Narcotics Anonymous (NA), a 12-step programme, where they were told that recovery was only possible with total abstinence and strict adherence to a set of rules. To them, it seemed as if they were being made to feel helpless in the grip of their addictions, which were thought of as a lifelong disease. The concept, pervasive in treatment, that addiction is a disease, emphasises the power of compulsions to overwhelm the individual. The problem, Smith told me, was that no one asked or cared about what her desires were. “When I was young and wanted to be a heroin addict, my behaviours were in line with my desires. Was that addiction?”
After she was accepted to university, Smith continued to use heroin. This was less of a personal failure, in her view, and more of a series of decisions she made to try to pursue both drugs and education at the same time. As long as Smith had access to drugs and wanted to use, she was not going to choose abstinence. On one occasion, Smith and Michael flung their unused needles and syringes down a garbage chute, desperate to begin their fresh start. Within hours, they dived into a skip to get them back.
After she was caught nodding out in front of customers, Smith was fired from her job, and later, so was Michael. Broke and withdrawing, they lay in bed until sunrise, racking their brains for fast money schemes to pay for heroin. Smith remembered hearing about an unsolved bank robbery near her parents’ home. The bank was a small redbrick building in an ideal location, abutting the entrance of the expressway, and it would be open at 8am.
While Michael slept, Smith collected her supplies: an Airsoft gun her stepfather had bought her for Christmas, the bright orange tip painted black; supermarket bags, a scarf to wrap around her head, and a pair of Jackie O sunglasses.
When she walked up to the front desk of the SunTrust bank and pointed her toy gun at the teller, Smith said: “You have 60 seconds to put money in these bags.” When the teller returned the plastic bags, Smith apologised and said: “Thank you.”
As her Volkswagen sped down Northshore Drive, a pack of dye in one of the bags detonated, staining the bills red and filling the car with scarlet smoke. On the expressway, Smith got out, tore the duct tape off her licence plate, and barrelled home. Stumbling into her apartment, Smith woke Michael up. After soaking the bills in their bathtub with water and bleach, they salvaged about $11,000, enough for two months of rent, food, and heroin.
The second robbery was more carefully planned. This time, Smith waited in the car while Michael went inside. But someone saw him leave the bank, and before they could get away, Smith and Michael were arrested.
Kirsten Smith during her younger years. Photograph: Greg Kahn/The Guardian
Awaiting trial under house arrest at the home of her mum and stepfather, Smith handwrote letters to Michael, who was also under house arrest just a couple of blocks away. She told him about the cocktail of medications she was given, which included Xanax and Focalin, a stimulant used to treat ADHD that enabled her to write poetry, a “countdown to prison” journal and a 450-page novel, all in a week.
Smith also drank heavily during this time. One night, with an ankle monitor on, she drove off drunk in her stepfather’s new car. Within two miles, she crashed into a tree and ended up in an emergency room downtown. With blood all over her face and wires holding her teeth together, Smith looked down and saw that she still had her bag, containing her syringe. She remembers that the first thing she thought was: “I still have time to buy heroin.”
In December 2007, at Smith’s sentencing hearing, her stepfather testified that he hoped she would get the treatment she needed to overcome her problems. “She is a smart person who has made some mistakes,” he said. “Made them willingly.”
Was Smith a patient simply in need of the right medications or a criminal who deserved punishment for actively choosing to harm others – or both? Before the hearing, in a character letter sent to the judge, Thomas Varlan, Smith chose to take responsibility for her crimes. “I wasn’t abused or molested as a child,” she wrote. “I didn’t grow up on the ‘wrong’ side of town. I wasn’t raised by wolves but by a mother and stepfather who love me and gave me countless opportunities to succeed.”
Smith was steadfast in her belief that her actions were volitional from the start. Her drug use and crimes were not the products of an immoral character or a faulty brain incapable of change, but rather of an environment where heroin was accessible and desirable. This outlook determined her experiences in prison and beyond, ultimately leading her to dedicate her life to challenging predominant medical models of addiction with her research. Today, she is an assistant professor of psychiatry and behavioural sciences at Johns Hopkins University in Baltimore, Maryland.
In light of the non-violent nature of their crimes and their youth, Judge Varlan sentenced Smith to 47 months in custody and Michael to 46 months, the minimum duration for their charges. Smith’s first destination, Blount county jail, was a concrete bunker or, as she put it, a “hell”. She went into drug withdrawal without a doctor to manage her symptoms. Without medical care, she had to remove the wires in her mouth with a fork.
Locked down 23 hours a day for two weeks with a wide-eyed stranger who rocked back and forth while withdrawing from cocaine, Smith, for the first time in her adult life, had no access to drugs or the outside world. The only reading material she had in the tiny room was a pocket-sized copy of the Gospels of the New Testament that community volunteers placed through a slot in the jail cell door. Smith read the words repeatedly to fall asleep; when she woke up, she started reading them again. After nine months, she was shipped to federal prison in Florida.
In Smith’s account of her story, no amount of psychiatric diagnoses or personal reflection helped her quit heroin. The only things that did were incarceration and forced abstinence, followed by her return to education. In prison, it occurred to Smith that there were only two things people could not take away from her: “my tattoos and my education”. After she was released, at the age of 27, she got a job serving sandwiches at a deli that hired former convicts – including Michael, although their romantic relationship was over. Smith stayed sober and was eventually accepted by the University of Kentucky, which – unlike some other institutions – did not require students to disclose past criminal charges. She excelled, and after four years of college went on to graduate school with the hope of becoming an addiction therapist.
Doing shifts at a rehab facility in 2015 while completing her master’s, Smith had a formative encounter with a man in his 20s who was detoxing from opioids. The patient mentioned to her that he had been drinking “a tea from Vietnam” called kratom. He said it soothed his anxiety and helped with his cravings for opioids. Although kratom is described by organisations such as the CDC as a stimulant, the patient said it did not make him feel high. However, the rehab facility enforced an abstinence-only approach to treating addiction, and Smith was required to report the young man. After he was kicked out of rehab, he stayed in contact with her, and told her about his commitment to achieving abstinence through the 12 steps. Two weeks later, he tried heroin and died from an overdose.
Actor Brad Renfro is handcuffed by LAPD officers after being arrested in 2005. Photograph: Mel Melcon/Los Angeles Times/Getty Images
In an essay titled Disease and Decision, published in 2022 in the Journal of Substance Abuse Treatment, Smith wrote about how, disillusioned by medical systems with no individualised or evidence-based care, she decided to change careers and turn her ambitions towards research. Often, Smith argued, people with substance-use disorders are actively discouraged from vocalising what they want from the recovery process. “If they try, they are told that they are selfish; that their character defects and thinking were what got them into trouble; and that thinking for themselves is dangerous.”
For Smith, free will is a spectrum, and yet many volitional behaviours get jumbled together under the label “addiction”, as if people with substance-use disorders have permanently lost control over their actions. She believes that although her desires, intentions and choices were constrained by factors that developed from continued drug taking – such as a lack of access to medical care, running out of money, being locked out of the university system – she maintains her behaviour was always the result of conscious decisions. For the same reason, she emphasises that lifelong cravings and relapses are not inevitable. Like everyone else, people who use drugs are “complex systems that can change”, and she believes that they should be held responsible for enacting that change.
Smith is thin and pale, with green eyes and dark curly hair. Her arms are covered in tattoos. On her right forearm, sealing the spot where she used to inject most frequently, are the words “Room 101”, the location in George Orwell’s Nineteen Eighty-Four where Winston Smith betrays his lover to escape his greatest fear. When she was incarcerated, relapsing became Smith’s greatest fear. “That’s the betrayal,” she told me. “I would have broken my mother’s heart, and broken the people who invested love and hope in me.”
The idea that addiction is a bodily disease was articulated in 1884 by the Scottish physician Norman Kerr. In his inaugural address to the Society for the Study and Cure of Inebriety, he said that addiction to alcohol is “for the most part the issue of certain physical conditions”. He continued: “Whatever else it may be, in a host of cases it is a true disease, as unmistakably a disease as is gout, or epilepsy, or insanity.”
Yet throughout most of the 20th century, a different model of addiction predominated in popular culture. The “moral model” sees addiction not as a disease of the body but of the will. Partly as a result, numerous countries adopted a penal approach to drug use that, particularly in the US, led to vast numbers of people being imprisoned for substance abuse.
A turning point came in 1997, when the then-director of the National Institute on Drug Abuse (Nida), psychologist Alan Leshner, published an article in the respected journal Science, in which he argued that addiction should be treated not as a moral failing but primarily as a chronic, relapsing disease of the brain. Addiction, according to Leshner, starts with voluntary consumption of drugs but over time the addictive qualities of the drug hijack the individual’s decision-making with uncontrollable cravings and compulsions.
Dr Norman Kerr. Photograph: Done & Ball
When I spoke to Leshner earlier this year, he explained how he sought to change addiction from a criminal issue into a public health problem that could be treated with medication instead of incarceration. He had been inspired by how advances in neuroscience had shifted cultural assumptions about people with schizophrenia, who had come to be viewed in a far more humane manner: as people with neurological diseases who deserved medical care. “It became clear to me,” Leshner said, “that a core difference between addicted and non-addicted people was the same as the core difference between individuals with and without schizophrenia – which is that they have changes in their brains.”
Leshner stands by his 1997 article, in which he recognised the importance of environmental and socioeconomic factors on persistent drug use but argued that over-emphasising social and spiritual solutions to addiction only worsened “the tremendous stigma attached to being a drug user or, worse, an addict”. (By overturning the moralistic attitude towards drug use, Leshner also sought to justify putting medications such as buprenorphine – a weak opioid restricted because of its potential for abuse – into doctors’ offices and prisons.)
Leshner’s approach, known as the brain disease model of addiction or BDMA, became the model for teaching addiction in medical schools in the US and beyond, as well as shaping drug education campaigns in schools. However, this approach has itself come under attack. Critics of BDMA, such as Smith, believe that downplaying the role of free will in addiction can dampen the belief that full recovery is possible. Smith does not deny that brains change from drug use – the impact of addictive substances on the brain’s reward pathways is well established – but claims that a perception of people with substance-use disorders as “recovering” but never “recovered” does little to improve the general understanding of addiction and can destroy any shred of hope that they may hold. Smith argues that terms such as “chronic” and even “disease” can push people with substance-use disorders and the people around them to see relapse as “an inevitable outcome”.
Similarly, Eric Strain, an addiction psychiatrist who has helped mentor Smith at Johns Hopkins University, argues that the BDMA oversimplifies our understanding of addiction. The BDMA, according to Strain, says doctors know what people with substance-use disorders need. “It implies: ‘Just take Suboxone, everything will get better’,” Strain explained to me, referring to a commonly prescribed medication. But things are not always so simple. “Look at the treatment dropout rates,” he said. “They’re abysmally high.”
The label of “disease” has trailed Smith for most of her adult life. After she obtained her PhD, which studied the treatment of substance-use disorders in incarcerated women, Smith went on to complete a four-year research fellowship at Nida, the centre of American addiction research. But her postdoctoral position came with conditions: she was forbidden from handling any of the money used to pay research participants or the drugs being tested in the labs. The issue of trust, and the assumptions people made about her capacity to function and resist relapsing, would not go away.
Smith belongs to a new generation of addiction scientists who are using their personal experiences to inform their research. Their focus is on helping people with substance-use disorders to identify the environmental factors that lead them to use drugs, and encouraging them to take action to change those factors.
In Smith’s own research at Johns Hopkins, which includes clinical trials and lab-based pharmacological studies, she interviews people with substance-use disorders about their experience of self-medication with unregulated substances like kratom. Instead of asking how the medical system can best force people into sobriety, Smith’s research asks how people with substance-use disorders have learned to manage their addictions themselves.
Justin Strickland, a behavioural pharmacologist who worked with Smith on models of addiction that emphasise environmental triggers, told me that there is actually more agreement than disagreement between supporters and detractors of the BDMA. “We all know that addiction is affected by neurobiology, genetics and childhood trauma,” he said. “The differences are in what is emphasised.” As the psychiatrist Carl Erik Fisher, who had an alcohol-use disorder during his medical training, wrote in his recent book about addiction, The Urge: “It is not that addiction is or is not a brain disease, or a social malady, or a universal response to suffering – it’s all of these things and none of them at the same time, because each level has something to add but cannot possibly tell the whole story.”
In the past five years, organisations such as Nida and the National Institutes of Health (NIH) have increasingly supported research into psychosocial approaches to addiction, harm reduction and methadone clinics, as well as community-based services that emphasise continuity of care. Meanwhile, some addiction scientists with histories of substance-use disorders think that the BDMA debate is still worth having. Noel Vest, a friend of Smith’s who is now an academic, began to use methamphetamines at the age of 21 and became addicted to alcohol. By 25, he had lost his business, his car and his house. After seven years in prison for multiple offences including identity theft, Vest became a drug and alcohol counsellor, which he abandoned when he realised his work was merely an extension of the criminal justice system he had just left. Treatment failure and missed appointments were an inherent part of recovery, and he refused to punish people for what he saw as the natural course of addiction. While on parole, Vest attended a local university and went on to complete a PhD in experimental psychology.
Judge Thomas Varlan and his wife, Danni Varlan, in Knoxville, 2017. Photograph: Caitie McMekin/News Sentinel via Imagn
For Vest, the problem is not the BDMA itself but how early the concept of disease and the necessity of treatment is forced on to people with substance-use disorders. “If you tell someone early on in addiction – someone who can’t even tie their shoes because they can’t put a thought together – that they have this lifelong condition that will never get better, that’s a huge leap most are not ready for.”
In many of my conversations with scientists both for and against the BDMA, one idea kept coming up: indeterminism. In an indeterministic model of addiction, any outcome, whether that be relapse or recovery, is neither predestined, nor fully within our control. The structure of the brain and one’s environment, as well as the influence of one’s past, are dynamic processes that we can study and attempt to shape, either through policy, treatments or personal choices. Hope and courage can coexist with chaos and chance.
In our conversations, Smith always maintained that her drug taking was a choice, and that she was saved from hitting rock bottom by her upbringing, which she frequently described as perfect. “I wasn’t abused,” she told me. “I practised violin. I had a lot of protective factors. A lot of people in prison do not have those things.”
Still, Smith’s childhood was not always straightforward. She describes her mother as a “good stay-at-home mother”, but she was also eccentric and volatile. When she divorced Smith’s father after 12 years of marriage, she plunged into a depression that she never fully rose out of. (“I had two people, whom I trusted and loved, telling me that the other person was evil,” said Smith, who was six when their drawn-out custody battle began.) While Smith was under house arrest, her mother attempted suicide for the first time. Returning home from prison years later, Smith found that her mother’s place was now packed with clutter. Her mother slept in the middle of the day, heavily medicated and not able to leave the house. In 2024, her mother died from complications with her medication regimen after a long struggle with mental illness. Months later, Smith’s stepfather also died.
It was in the period after her mother and stepfather’s deaths that Smith was hired as an assistant professor at Johns Hopkins. Last year, the district court in Knoxville invited Smith to speak at a graduation ceremony for a programme called Full Circle that allowed people in prison with substance-use disorders to leave federal probation early after a year of working with a mentor.
At the ceremony, Smith met the judge who had sentenced her all those years ago. The memory of that day, probably the bleakest of her existence, was a blur. “I remember looking up at this thing that was clearly a judge,” she recalled. “But I was crying so hard when I addressed him that I only remember sobbing.”
It was difficult to look him in the eyes. Judge Varlan was a head taller than Smith, with a wiry frame and a clean-shaven face. She was surprised how quiet he was. His cadence was slow, his demeanour laconic, but his smile was warm and fatherly. To the judge’s wife, Smith expressed how nervous she was to meet them. Mrs Varlan smiled with tears in her eyes, and reassured Smith that the judge had been looking forward to her visit.
In her speech, Smith told the graduates: “Most of us in this room are likely hard-headed and stubborn. Turning that stubbornness in the right direction can be a powerful thing.”
Shoulder to shoulder with Judge Varlan, Smith watched a dozen or so ex-inmates walk across the stage, many starting over at an older age than she had. It sank in how rare “full circle” moments were for people like her. She had willed it into existence by remaining, as the judge and his wife, and Smith’s mother and stepfather had been, stubborn about her ability to change.
A broad swath of neuropsychiatric conditions, including autism, depression and schizophrenia, share genetic underpinnings. But individual variants can have strikingly different effects on clinical diagnoses: A variant that increases the likelihood of one condition may reduce that of another, according to two new preprints.
“When you delete and duplicate genes, you get very different, often diametrically opposed, outcomes,” says Jonathan Sebat, professor of psychiatry and cellular biology at the University of California, San Diego and co-principal investigator of the studies. He and his colleagues analyzed whole-genome sequencing data from 574,965 people, collected at dozens of institutions as part of the Psychiatric Genomics Consortium, a massive international project aimed at finding common variants in psychiatric conditions.
The work, posted on medRxiv in July, revealed nearly three dozen links between copy number variants (CNVs)—deletions or duplications of small segments of DNA—and any of six different neuropsychiatric conditions: autism, attention-deficit/hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder, post-traumatic stress disorder (PTSD) and schizophrenia.
Nearly all of these rare variants are tied to more than one diagnosis, one of the studies shows. But duplications and deletions can have different and sometimes opposite effects: If a deletion raises a condition’s likelihood, the corresponding duplication may lower it, and vice versa.
Autism was unique in that no deletions or duplications decreased autism probability, whereas some variants lowered the chances of having schizophrenia or one of the other conditions, Sebat says.
“What was surprising is that sometimes a gene duplication can be protective,” says Hyejung Won, associate professor of genetics at the University of North Carolina School of Medicine, who did not contribute to the studies. “That provides a lot of food for thought. How does excessive expression of a gene protect you from another disorder?”
The six neuropsychiatric conditions analyzed in the first study converge on a common set of molecular pathways but are associated with distinct cell types, brain regions and gene dosages, according to the other study.
“The overlapping biology of these disorders might not be quite as overlapping as we would have thought,” says Jason Lerch, professor of neuroscience at the University of Oxford, who did not contribute to the research. “This is important stuff.”
B
ecause the list of thousands of genes linked to neuropsychiatric conditions doesn’t say much about how those genes affect psychiatric traits, Sebat and his colleagues turned to deletions and duplications, which predictably alter gene dosage—an approach akin to studying gain- or loss-of-function variants, he says.
Genome-wide association studies involving participants grouped according to six psychiatric diagnoses revealed a total of 35 associations between rare CNVs and least one of the conditions. In the case of schizophrenia, for example, deletions in the 22q11.21 A-D chromosomal region significantly increase likelihood, whereas duplications decrease it. And the effect sizes of schizophrenia-linked reciprocal deletions and duplications are inversely correlated, indicating a linear dose-dependent relationship between gene copy number and a person’s chances of having schizophrenia.
A similar pattern held for other chromosomal regions and diagnostic categories, but not all. Autism was a notable exception because no CNV decreased the likelihood of having the condition—perhaps because autism encompasses a particularly broad spectrum of traits, Sebat says.
The second study identified gene sets based on the genes’ roles in molecular pathways, along with cell types, brain regions and gene dosage (duplication or deletion), and then determined which genes sets correlated with which psychiatric conditions by way of a gene-set burden analysis.
All of the 35 CNVs flagged in the first study act on a small set of molecular pathways, such as MAPK signaling, synaptic transmission or chromatin regulation, the second study showed. “All of the same 19 canonical pathways are involved in all disorders,” Sebat says. And separating these pathways by cell type and brain region in addition to gene dosage showed further distinctions among conditions, he says.
This multidimensional analysis provided three unique factors, or signatures, that captured the neurobiological processes involved in each condition. Schizophrenia, for example, is strongly associated with factor 1, a set of genes involved in chromatin regulation and MAPK signaling, specifically in postnatal excitatory neurons, microglia and vascular cells. And it is linked primarily to duplications in cell signaling and metabolic pathways in postnatal excitatory neurons and neurovascular cells, as well as to deletions in inhibitory interneurons.
This pattern supports the hypothesis that schizophrenia is associated with an imbalance in excitation and inhibition, Sebat says.
Autism is also strongly correlated with factor 1—a finding that aligns with past studies that point to microglia and postnatal excitatory neurons, as well as chromatin remodeling. But both duplications and deletions linked to autism act on the same pathways and cell types in most cases. In addition, deletions that increased autism likelihood were linked to a decrease in schizophrenia risk, the study showed.
Factor 2, which is associated with mood disorders, isn’t strongly tied to specific pathways and involves changes in non-neuronal cells. Factor 3 separates conditions by brain region: In bipolar disorder, for instance, deletions are concentrated in frontotemporal regions, whereas in ADHD, depression and schizophrenia, they are more common in sensory regions.
T
he directional effects of duplications and deletions are interesting, says Mark Gerstein, professor of biomedical informatics at Yale University, who was not involved in the research. But duplications and deletions do not lead only to increases or decreases in protein expression, he says. In practice, both can also lead to novel protein functions or disruptions that weren’t captured in the study’s analysis.
Sebat contends that the general equivalence between gene copy number and protein expression holds, but he adds that deletions and duplications can both disrupt gene functions in unpredictable ways. “There’s still a lot we don’t know,” he says.
Ultimately, the findings could one day help clinicians distinguish different clinical presentations of heterogeneous diagnoses such as autism, Sebat says.
Won agrees. If this line of study can identify “some disease specificity,” she says, “we can diagnose individuals with better genetic etiology and find tailored therapeutic options.”
A new study reveals the profound emotional and physical toll of extreme morning sickness, with more than half of affected women reporting they considered terminating their pregnancy, and 9 in 10 saying they had thought about not having more children.
The national survey, published in PLOS ONE, is one of the most comprehensive investigations into the lived experience of hyperemesis gravidarum (HG)-a severe form of nausea and vomiting in pregnancy – in Australia.
It highlights not only the debilitating nature of the condition but also the inconsistent effectiveness of commonly prescribed treatments.
Lead author Associate Professor Luke Grzeskowiak, a pharmacist and researcher from Flinders University, says that the findings underscore the urgent need for more compassionate, evidence-based care for pregnant women experiencing HG.
“Hyperemesis gravidarum is not just morning sickness-it’s a serious condition that can have devastating consequences for women’s mental health, relationships, and decisions about future pregnancies,” says Associate Professor Grzeskowiak.
“Our study shows that many women are not getting the support or relief they need, and that’s something we must urgently address.”
The survey of 289 Australian women found that 54% had considered terminating a pregnancy due to HG symptoms, while 90% had considered not having more children.
The condition was also linked to high rates of anxiety and depression, with 62% of respondents reporting they ‘often’ or ‘always’ experienced these feelings during pregnancy.
Despite the severity of symptoms, only half of the women surveyed rated commonly used treatments as effective.
Ondansetron, doxylamine and corticosteroids were perceived as the most effective medications, yet many women reported significant side effects, including constipation, sedation, and impaired cognition.
Metoclopramide, another frequently used drug, was discontinued by nearly one-third of users due to adverse effects.
“Women are often prescribed multiple medications in an attempt to manage their symptoms, but the reality is that many of these treatments come with their own burdens,” says Associate Professor Grzeskowiak.
“We need better evidence to guide treatment decisions and ensure women are supported to make informed choices.”
Beyond the physical symptoms, the study paints a dismal picture of the broader impact of HG on women’s lives.
More than half of respondents reported major disruptions to their ability to work, care for children, maintain relationships, and perform daily tasks. Thirty-seven per cent requested early induction of labour to end their pregnancy sooner due to the severity of their symptoms.
Caitlin Kay-Smith, founder of consumer organisation Hyperemesis Australia and co-author on the study, says the findings should prompt a shift in how HG is understood and managed in clinical settings.
“Too often, women’s symptoms are dismissed as a normal part of pregnancy, when in fact they are experiencing a condition that can be life-altering,” she says.
“We need to move away from a one-size-fits-all approach and toward personalised care that recognises the full impact of HG.”
The study was co-designed with Hyperemesis Australia and supported by the Robinson Research Institute at the University of Adelaide. It calls for further research into the long-term effects of HG and its treatments, as well as greater investment in support services for affected women.
Associate Professor Luke Grzeskowiak says the message from women was clear: “They want to be heard, believed, and treated with dignity.”
Source:
Journal reference:
Wills, L., et al. (2025). Assessing the burden of severe nausea and vomiting of pregnancy or hyperemesis gravidarum and the associated use and experiences of medication treatments: An Australian consumer survey. PLOS One. doi.org/10.1371/journal.pone.0329687
What exactly happens when syngas is produced? New methods allow to observe the process in real time. This answered the question how catalysts work in detail.
Atomic resolution images of PdO (red) and Pd (blue) structures and interfaces, with a corresponding illustration of the catalysts surface (right) and the microreactor in the electron microscope (left).
TU Wien
For many industrial applications one needs synthesis gas, also known as “Syngas”, a mixture of hydrogen (H2) and carbon monoxiode (CO). In addition to the established production method via steam reforming, synthesis gas can alternatively—and even more energy‑efficiently—be produced from methane (CH₄) and oxygen. However, in this process the total oxidation (combustion) of methane to CO2 and H2O must be avoided, which is why there is vivid research on syngas production worldwide.
Catalysts containing elements such as palladium are used for this purpose. Until now, however, it has been unclear exactly how the conversion of methane to syngas proceeds on palladium surfaces. Through a collaboration between TU Wien and the National University of Singapore (NUS), it has now been possible to observe the process using high‑resolution transmission electron microscopy —by so‑called operando TEM— combined with computational simulations. The results show that the reaction requires a synergy between different catalyst regions.
Palladium and palladium-oxide
“Methane is the main component of natural gas. Today we do not only use it for heating—which is problematic for reasons of global warming—but also as a feedstock for producing chemicals and fuels,” says Prof. Günther Rupprechter from the Institute of Materials Chemistry at TU Wien. “Even in the future, methane will therefore play a role in generating syngas and probably cannot be completely replaced within the next decade.”
This is why intensive research is being carried out today to find new processes to produce syngas from methane more efficiently while avoiding over‑oxidation—that is, combustion to CO₂ and water. This process is called “partial oxidation of methane” (POM). “In recent years we have investigated POM on various catalysts, most of which were nickel‑based,” Rupprechter says.
A microreactor in an electron microscope
It was already known that catalysts made of metal nanoparticles work well. But the open question was what exactly happens to the individual metal nanoparticles during the catalytic reaction. “In particular, we wanted to know: if the reaction is carried out with palladium nanoparticles, is palladium itself responsible for the catalysis, or palladium oxide, which forms during the reaction?”
This question could now be addressed for the first time through a combination of advanced approaches: The team observed the nanoparticles in real time during the catalytic reaction using high‑resolution transmission electron microscopy. At the same time, mass spectrometry was used to monitor which products form at which point in time—and all of this was complemented by computer simulations. This combination made it possible, for the first time, to obtain a more precise mechanistic picture of the process.
How does the catalyst work?
Alexander Genest from the TU Wien team, who was previously affiliated to the A*STAR High Performance Computing Centre in Singapore, has kept the collaboration between TU Wien and Singapore alive over the years. “Using computational modeling, we had previously looked into Pd nanoparticle oxidation and CO oxidation, so that the extension to methane oxidation was a very promising target”, says Alexander Genest.
Together with PhD candidate Parinya (Lewis) Tangpakonsab, he carried out simulations based on density functional theory (DFT) to study methane activation and the subsequent reaction steps. “We wanted to understand the origin of partial and total oxidation and to clarify exactly what happens at the atomic level,” says Tangpakonsab.
Metal and oxide: successful only in combination
The result was more complex than expected: neither the metal nor the metal oxide alone is responsible for the catalysis—the best performance comes from the two working together. “The two phases take on different tasks,” explains Günther Rupprechter. “The palladium dehydrogenates methane to carbon and hydrogen, while the palladium oxide oxidizes the carbon to CO.” This means that the most efficient catalysis can take place solely at the boundary regions between palladium and palladium oxide.
“Our group has already been very active in electron microscopy of surface oxidation reactions in the past, but this new operando‑TEM study extends this work to industrial conditions. Supported by the MECS Cluster of Excellence, we will soon have special reactor cells also available at TU Wien for similar operando‑TEM examination,” says Günther Rupprechter, Research Director of MECS.
Copper fell for a second day on the London Metal Exchange, as base metals staged a broad retreat ahead of key jobs data from the US later this week.
The red metal dropped 0.5% to trade at $9,926 a ton as of 11:45 a.m. Singapore time, after hitting its highest since March in intraday trading on Wednesday. The next major event for markets is on Friday, with a US payrolls report that should steer the Federal Reserve’s next moves on interest rates.
Love jamming out on the trails? We do too. Shokz have been delivering the party to outdoor enthusiasts and active individuals since 2011. They are well-known for their bone conduction headphones, and 2023 saw the introduction of the open ear range, including the OpenFit.
The idea behind all Shokz headphones is to allow you to listen to music or a podcast without compromising your awareness and still being able to hear what’s going on around you.
Earlier this year, Shokz launched a revised OpenFit model, alongside an all-new offering dubbed OpenDots ONE. We’ve been boogying down on the trails for the past few months to see what they are like from a mountain biker’s perspective.
The handy little cases are compact and easy to throw in the pocket, and double as a charging bank for the earbuds.
Shokz OpenFit 2+ Earbuds
The OpenFit 2+ is the brand’s updated open-ear offering, expanding on the original OpenFit model, utilising a flexible ear-hook design.
To produce a wide range of sound frequencies, it uses two individual speakers. A large, low-frequency speaker drops the bass, while an independent high-frequency speaker takes care of the elevated tones. They are left and right specific, and it’s relatively intuitive as to which one goes where.
While they are ear buds of a sort, given that you’re ear canal remains unobstructed, you can still hear the ambient noises around you while you make your way through Taylor Swift’s back catalogue, or Dr Karl drops some science knowledge as you ride.
An inbuilt magnet zaps each earbud satisfyingly into place.
To control the audio, both the left and right earbuds have a physical button, which comes preconfigured with easy-to-remember controls. A single press pauses music; a double press skips to the next track. If you have an incoming call, a single press answers the call.
Each earbud also has a ‘touch area’ button, which is configured to do nothing by default. In the Shokz app, these can be set to control the voice assistant on your phone. Need to ask Siri what time your favourite Ramen restaurant closes quickly? A long press on the side of the bud and Siri kicks into gear with the answer.
The aesthetic of flexible ear-hook design is somewhat akin to something a secret agent would wear, with a sprinkle of modern style. It’s a little fiddly to get on in the right spot, but once in place, it sits very securely with minimal movement or need for adjustment.
The flexible ear loop works well with helmets and riding glasses, and provides a secure fit.
Both OpenFit 2+ earbuds fit neatly within the supplied case, which doubles as a battery bank for charging. The 56mAh batteries in the earbuds can deliver up to 11 hours of listening, and the 600mAh battery in the case zaps charge into the earbuds, delivering up to 48 hours of playtime. They are IP55 water-resistant too, meaning sweat and rain won’t ruin the tunes.
Key Details
Connectivity | Bluetooth 5.4, 10m range
Waterproofing | IP55
Battery | Li-ion, 48hrs playtime
Weight | 9g per earbud, 56g case
Price | $339 AUD
Slightly unconventional looks, but the OneDots ONE fit well and produce some serious sound.
Shokz OpenDots ONE Earbuds
New in the brand’s lineup is the OneDots ONE, a fresh take on open ear headphones. They sit in the same ‘True Wireless’ range as the OneFit 2+, but with a completely new light clip design.
The OneDots ONE are lightweight and compact, with a minimalistic design that softly clips onto the lower part of your ear. They definitely aren’t as secure as the flexible ear-hook design, and in a decent crash, we can envisage them being a part of the yard sale.
That being said, whether you’re riding, running, or at the gym, the OneDots One buds sit firmly in place with no unwanted jiggle. The earbuds have no specific side, so you can just throw them on, without having to think about which one goes where.
They sit well clear of the helmet straps and glasses, but certainly aren’t as secure as the OpenFit 2+.
There are two touch control options for the OneDots One buds. A single tap of either the ‘JointArc’ or battery compartment, or a gentle two-finger pinch of either end of the battery compartment, plays or pauses music and answers incoming phone calls. In the default configuration, you can not skip or replay songs, so you’re going to want to make sure you’ve got a full playlist of bangers lined up. This is all customisable through the Shokz app, however, so you can add music control with a triple-tap of the ‘JointArc’.
The audio isn’t quite as ‘full’ as the OpenFit 2+; there’s a little less bass, but overall, the sound quality is still impressive. We found the audio quality and volume to be quite sensitive to the positioning on the ear. If they shake or knock out of place, or aren’t quite in the right spot, the quality drops drastically.
And similar to the OpenFit 2+ and all of Shokz other headphones, you’re not blocked off from the world and can hear what’s going on around you.
All that sound out of that little speaker? Impressive.
The case of the OpenDots ONE is slightly more compact, doubling as a battery bank for charging. The 60mAh batteries in the earbuds can deliver up to 10 hours of listening, and the 590mAh battery in the case zaps charge into the earbuds, delivering up to 40 hours of total runtime. Similar to OneFit, they are also IP55 water-resistant, meaning sweat and rain won’t spoil the party.
Key Details
Connectivity | Bluetooth 5.4, 10m range
Waterproofing | IP55
Battery | Li-ion, 40hrs playtime
Weight | 7g per earbud, 39g case
Price | $339 AUD
Shokz App
Shokz have developed a specific app to control both the OpenFit and OpenDot earbuds. Users can choose from different sound modes, including ‘Bass Boost’, ‘Vocal’, ‘Treble Boost’ or ‘Standard’, or even customise their own sound mode.
There is also the ability to enable the ‘Dolby Audio’ setting, which creates a more vivid, realistic and immersive sound from each of the buds. It seems a little odd that this is off by default, as it makes a significant improvement to the overall sound quality and experience.
Both OpenFit and OpenDots earbuds can be paired with multiple devices simultaneously through the app, making it easy to switch between your phone and laptop.
You can even customise the buttons, tailoring the single, double or triple clicks to the user’s preferences. Overall, the app is easy and intuitive to use, offering excellent control over the earbuds. We can’t imagine that folks will use it every time they throw on the earbuds, but it adds value to the overall package.
Both the OpenFit 2+ and OpenDots ONE can be configured with the Shokz app. Although we found it unusual that the Dolby Audio setting is configured to be off by default.
Flow’s Take
Both the OpenFit 2+ and OpenDots ONE provide outstanding audio clarity and a unique fit that feels weightless when wearing. They provide superior spatial awareness compared to traditional in-ear earbuds, and the brand’s claim as to their ‘True Wireless’ functionality is certainly true. In our experience, both options fit well with riding helmets and sunglasses, making them an attractive choice for riders who love jamming out to music on the trails.
We really liked the minimalistic design of the OpenDots ONE, and the simple light clip was easy to use and comfortable to wear. The flexible hook design of the OpenFit 2+ provides a more secure fit, however, and might be a better choice for those who frequent rougher trails.
Act now! Experts warn of active exploitation of vulnerabilities in several Sitecore products
The company behind CMS products used by companies such as L’Oreal, Microsoft, Toyota, and more has disclosed a critical vulnerability that hackers are already attempting to exploit.
Australian software company Sitecore has warned of a critical vulnerability in several of its products that could lead to remote code execution and the exfiltration of sensitive data.
The vulnerability – tracked as CVE-2025-53690 – potentially impacts four of Sitecore’s products: Experience Manager, Experience Platform, Experience Commerce, and Managed Cloud.
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The issue impacts customers who followed the deployment instructions that came with XP 9.0 or earlier and Active Directory 1.4 or earlier. In some cases, customers have been found to have used the sample machine key included in those instructions, which date back to 2017.
“The issue stems from Sitecore users copying and pasting example keys from official documentation, rather than generating unique, random ones – a move we don’t recommend,” Ryan Dewhurst, watchTowr’s head of proactive threat intelligence, told Cyber Daily.
“Any deployment running with these known keys was left exposed to ViewState deserialisation attacks, a straight path right to remote code execution.”
Sitecore has recommended its customers rotate machine keys immediately, but that may not be enough, according to Caitlin Condon, VP of security research at VulnCheck.
“Unfortunately, rotating keys and locking down configurations isn’t enough on its own if threat actors were able to gain access to an organisation’s network,” Condon said.
“Security and threat hunting teams will need to examine environments for signs of compromise, particularly since Mandiant’s investigation found the (unattributed) threat actor had deployed malware and additional tooling geared toward internal reconnaissance and persistence across one or more compromised environments.”
What Condon is referring to is a detailed blog post from Mandiant outlining malicious activity it has already detected and prevented.
“In a recent investigation, Mandiant Threat Defense discovered an active ViewState deserialisation attack affecting Sitecore deployments leveraging a sample machine key that had been exposed in Sitecore deployment guides from 2017 and earlier,” Mandiant said on 3 September.
“An attacker leveraged the exposed ASP.NET machine keys to perform remote code execution.”
Mandiant said the threat actor seemed to have a deep understanding of Sitecore’s products, moving fast from initial compromise to privilege escalation. The attacker was able to establish a backdoor, maintain persistence, and deploy malicious tooling before beginning to perform network reconnaissance. Mandiant was able to stop the attack, which means it was unable to observe the life cycle of the attack.
Thankfully, Sitecore has said that new deployments will automatically generate keys, but more malicious activity may remain undetected, for now.
“Sitecore has confirmed that new deployments now generate keys automatically and that all affected customers have been contacted,” Dewhurst said.
“The blast radius remains unknown, but this bug exhibits all the characteristics that typically define severe vulnerabilities. The wider impact has not yet surfaced, but it will.”
David Hollingworth
David Hollingworth has been writing about technology for over 20 years, and has worked for a range of print and online titles in his career. He is enjoying getting to grips with cyber security, especially when it lets him talk about Lego.