Category: The Conversation – USA

Source: The Conversation – USA – By Vahe Peroomian, Professor of Physics and Astronomy, USC Dornsife College of Letters, Arts and Sciences

As a space scientist, every time I go outside with my family, I tell my children to look up at the sky. The front door of our home looks southeast, and on winter nights the constellation Orion hangs majestically just above the horizon as soon as it grows dark enough to see stars.

One summer night, my son came running in and exclaimed, “Dad, Orion’s not there!” It was time for his first real astronomy lesson.

We went outside and I asked him to find the Big Dipper, the easily identifiable pattern of stars that make up a portion of the constellation Ursa Major. I reminded him that we could always see the Big Dipper no matter what time of the year it was.

So, why is it that Orion is not always visible in the night sky, and certainly not in the same location month after month, while the Big Dipper always is? The answer is intimately tied to a few concepts: how astronomers measure the length of a day, the motion of the Earth around the Sun during a year, and the cadence with which stars rise and set night after night.

Sidereal time

If you look eastward at the same hour for two nights in a row, you’ll find that the stars seem to be in the same place. But they’re not, and this movement becomes apparent if you continue observing at the same hour for a week or more. A combination of the Earth’s daily rotation on its axis and its yearly orbit around the Sun cause them to appear to move across the sky.

Earth spins on its axis, which runs from the South Pole through the center of the Earth to the North Pole, once a day. Astronomers measure a day in two different ways: They measure a solar day, 24 hours long, with the position of the Sun from high noon to high noon. They measure a sidereal day with respect to distant stars that are fixed in the sky. A sidereal day is 23 hours and 56 minutes long.

The constellation Orion – and every star in the night sky – will appear in exactly the same place every 23 hours and 56 minutes. Because of this slight offset, stars will appear to rise four minutes earlier every 24 hours on successive nights. Over the course of a month, a star that was close to the eastern horizon at 10 p.m. will now be much higher in the sky, having risen two hours earlier.

So while the constellation Orion appears close to the horizon at sunset in late December, it is nearly overhead in February and March.

You can use an interactive star chart to see this phenomenon. Do you want to find Orion in August in North America? Just wake up at 4:30 a.m. and look eastward.

Unlike Orion, the Big Dipper is always visible at night in most of the Northern Hemisphere. This is because of how Earth’s daily rotation is projected onto the stars.

Circumpolar stars

Astronomers use a common set of reference points to project Earth’s north and south poles, and the equator, onto the celestial sphere, an imaginary sphere encompassing the sky.

The idea of the celestial sphere evolved in ancient times from the notion that the Earth was the unmoving center of the universe. The projection of Earth’s equator delineates the celestial equator, and the poles project onto the north and south celestial poles.

The motion of stars near the celestial poles differs from how Orion and other constellations behave. Presently, the north celestial pole is very close to the star Polaris, also known as the North Star. Stars close to Polaris never rise or set. They appear to circle counterclockwise around that star as the Earth spins on its rotation axis once a day.

The number of these circumpolar stars increases as you move toward the North Pole. There are no circumpolar stars at the equator. Every star and constellation rises in the east and sets in the west because Earth rotates west to east on its axis.

If you are standing at the North Pole, every northern constellation is circumpolar, circling the North Star and never rising or setting. The pattern is similar in the Southern Hemisphere, with the southern constellations circling clockwise around the south celestial pole.

Earth’s precession

Millennia ago, people charted the path of the Sun through the constellations of the zodiac, which birthed the practice of astrology.

What does it mean for the Sun to be in Sagittarius, for example? It means that to see the constellation Sagittarius, you have to be looking toward the Sun. That would make it daytime, when the stars are not visible. Wait for nightfall, and you can see Gemini high in the sky. Six months later, the Sun is in Gemini, and Sagittarius is visible in the night sky. This pattern repeats year after year, as the Earth orbits the Sun. Your zodiac signs depend on which constellation the Sun was in when you were born.

There is one other change in the night sky that occurs on time scales much longer than a human lifetime. Because of the gravitational influence of the Sun, and to a lesser extent Jupiter, on Earth’s daily rotation, Earth’s spin axis precesses, or moves in a circle, like a toy top spun on a table.

Because of this motion, which also subtly changes Earth’s orbit in space, Polaris will no longer be the North Star a thousand years from now. Wait 12,000 years, and the bright star Vega will be closest to the north celestial pole, more than 50 degrees across the night sky from its present location near Polaris.

Another consequence of this motion, sometimes referred to as the precession of the equinoxes, is that today the constellations of the zodiac no longer align with the traditional dates associated with them.

For example, when horoscopes and astrological signs were originally devised, the Sun was in the constellation Sagittarius from Nov. 22 to Dec. 21. However, because of precession over thousands of years, the Sun now crosses this constellation from Dec. 18 to Jan. 19. It spends the early part of December in Ophiuchus, which is not part of the traditional 12 constellations of the zodiac.

These changes in the night sky take weeks, months or even hundreds of years to be visible. If you’re not that patient, you can fly to the opposite hemisphere to see Orion upside down and the night sky turning in the opposite direction above.

Vahe Peroomian has, in the past, received funding from the National Science Foundation (NSF) and from the National Aeronautics and Space Administration (NASA) for research in the field of space science.

– ref. Why are some stars always visible while others come and go with the seasons? – https://theconversation.com/why-are-some-stars-always-visible-while-others-come-and-go-with-the-seasons-274096

Source: The Conversation – USA (3) – By Ziyad Al-Aly, Clinical Epidemiologist, Washington University in St. Louis

A patient of mine, a veteran who had tried to quit smoking for over a decade, told me that after he started a GLP-1 drug for his diabetes, he lost interest in cigarettes. He didn’t use a patch. He didn’t set a quit date. He simply lost interest. It happened without effort.

Another patient on one of these drugs for weight loss told me that alcohol had lost its pull – after years of failed attempts to quit.

People struggling with many addictions, ranging from opioids to gambling, are reporting similar experiences in clinics, on social media and around dinner tables. None of them started these drugs to quit. This pattern of people losing their cravings across a broad range of addictive substances has no precedent in medicine.

But my patients were giving me an important clue. People taking GLP-1 drugs often talk about “food noise” vanishing: the constant mental chatter about food that dominated their days simply goes quiet. But my patients were reporting that it wasn’t just food: They were noticing that the preoccupation with smoking, drinking and using drugs that drives people back despite their best intentions to stop was going quiet too.

As a physician whose patients are often on GLP-1 drugs, and as a scientist who works on answering pressing public health questions – from long COVID to medication safety – I saw a problem hiding in plain sight: Many addictions have no approved treatment. The few medications that exist are massively underutilized, and none works across all substances. The idea that a drug already taken by millions might do what no addiction treatment has done before was too important to ignore.

My team and I set out to test whether GLP-1 drugs – medications like semaglutide (Ozempic and Wegovy) and tirzepatide (Mounjaro and Zepbound), originally developed for diabetes and then approved for obesity – could do what no existing addiction treatment does: curb craving itself.

Our evidence strongly suggests they can.

Biological basis of cravings

The hormone that these drugs mimic – GLP-1 – is not only produced in the gut. It is also active in the brain, where the receptors it binds to cluster in regions governing reward, motivation and stress – the same circuitry that gets hijacked by addiction. At therapeutic doses, GLP-1 drugs cross the blood-brain barrier and dampen dopamine signaling in the brain’s core reward center, making addictive substances less rewarding.

GLP-1 drugs seem to inhibit cravings for several different substances in multiple animal models. For instance, rodents given GLP-1 drugs drink less alcohol, self-administer less cocaine and show less interest in nicotine. When researchers gave semaglutide to green vervet monkeys – primates that voluntarily drink alcohol much like humans do – the animals drank less without showing signs of nausea or changes in water intake. This suggests the drug lowered the reward value of alcohol rather than making the animals feel sick.

From animals to people

To find out whether these drugs have a similar effect on people, we turned to the electronic health records of more than 600,000 patients with Type 2 diabetes at the U.S. Department of Veterans Affairs – one of the largest health care databases in the world.

We designed a study that applied the rigor of randomized controlled trials – the gold standard in medicine – to real-world data. We compared people who started GLP-1 drugs to people who did not, adjusting for differences in health history, demographics and other factors, and followed both groups for three years.

My team and I asked two questions: For people already struggling with addiction, did the drugs reduce overdoses, drug-related hospitalizations and deaths? And for people with no prior substance use disorder, did GLP-1 drugs reduce their risk of developing one across all major addictive substances: alcohol, opioids, cocaine, cannabis and nicotine?

What we found was striking. In the group already struggling with addiction, there were 50% fewer deaths due to substance use among those taking GLP-1 drugs compared with those who were not. We also found 39% fewer overdoses, 26% fewer drug-related hospitalizations and 25% fewer suicide attempts. Over three years, this translated to roughly 12 fewer serious events in total per 1,000 people using GLP-1 drugs – including two fewer deaths.

Reductions of this magnitude are rare in addiction medicine – and what’s remarkable is that the finding came from drugs initially designed for diabetes, later repurposed for obesity and never intended to treat addiction.

The drugs also appeared to prevent addiction from developing in the first place. Among people with no prior substance use disorder, those taking GLP-1 drugs had an 18% lower risk of developing alcohol use disorder, a 25% lower risk of opioid use disorder and an approximately 20% lower risk of cocaine and nicotine dependence. Over three years, this translated to roughly six to seven fewer new diagnoses per 1,000 GLP-1 users.

With tens of millions of people already using GLP-1 drugs, the reductions in deaths, overdoses, hospitalizations and new diagnoses could translate into thousands of prevented serious events each year.

Converging evidence

Our findings align with a growing body of evidence.

A Swedish nationwide study of 227,000 people with alcohol use disorder found that those taking GLP-1 drugs had 36% lower risk of alcohol-related hospitalizations. This is more than double the 14% reduction that the same study found with naltrexone, which was the best-performing medication approved for treatment of alcohol use disorder in that analysis. Other observational studies have linked GLP-1 drugs to lower rates of new and recurring alcohol use disorder, reduced diagnoses and relapse in cannabis use disorder, fewer health care visits for nicotine dependence and lower risk of opioid overdose.

Meanwhile, randomized controlled trials that directly test whether these drugs help people with addiction also show promise. In one trial, semaglutide reduced both craving and alcohol consumption in people with alcohol use disorder. In another, dulaglutide reduced drinking. More than a dozen additional trials are already underway or actively enrolling, and several more are planned.

The future of addiction treatment

GLP-1 drugs are the first type of medication to show potential benefit across multiple substance types simultaneously. And unlike existing addiction medications, which are prescribed by specialists and remain vastly underused, GLP-1 drugs are already prescribed at enormous scale by primary care doctors. The delivery system to reach millions of patients already exists.

The consistency of GLP-1 effectiveness across alcohol, opioids, cocaine, nicotine and cannabis suggests these drugs may act on a shared vulnerability underlying addiction – not on any single substance pathway. If confirmed, that would represent a fundamental shift in how society understands addiction and how doctors treat it.

Some unanswered questions remain, though, about how these drugs would affect addiction. Many people who take GLP-1 drugs to treat obesity or diabetes discontinue them; afterward, their appetite typically returns and they regain the weight they lost. Whether the same rebound would occur with addiction, and what it would mean for someone in recovery to face the roar of craving again, is unknown. Nor is it clear whether the benefits persist over years of continuous use, or whether the brain adapts in ways that dampen those effects.

Also, because GLP-1 drugs engage the brain’s reward circuitry – the same system that governs not just craving but everyday motivation – prolonged use could, in theory, dampen motivational drive in some people. Whether that might affect real-world outcomes, such as initiative, competitive drive or performance at work, remains an open question.

What comes next

GLP-1 drugs have not been approved for addiction, and there is not yet enough evidence to prescribe them solely for that purpose. But for millions of people already weighing whether to start a GLP-1 drug for diabetes, obesity or another approved indication, it is one more factor worth considering.

A patient living with diabetes who is also trying to quit smoking might reasonably choose a GLP-1 drug over another glucose-lowering medication, not because it is approved for smoking cessation, but because it may help them quit, a benefit that other diabetes drugs do not offer. Similarly, for people living with obesity who also struggle with alcohol, the potential for benefit beyond weight loss could be one more reason to consider a GLP-1 drug.

If additional trials confirm that they effectively curb cravings across addictive substances, these drugs could begin to close one of the most consequential treatment gaps in medicine. And the most promising lead in addiction in decades will have come not from a deliberate search but from patients reporting a benefit no one anticipated. Like my patient who quit smoking after a lifetime of trying, it happened without effort.

Ziyad Al-Aly receives funding from U.S. Department of Veterans Affairs.

– ref. GLP-1 drugs may fight addiction across every major substance, according to a study of 600,000 people – https://theconversation.com/glp-1-drugs-may-fight-addiction-across-every-major-substance-according-to-a-study-of-600-000-people-275233

Source: The Conversation – USA – By Houlong Zhuang, Associate Professor of Engineering, Arizona State University

From hypersonic aircraft to nuclear-powered submarines, many of today’s most advanced defense systems rely on a special class of materials known as refractory alloys. This class refers to metals that do not melt or weaken easily, even in extreme heat.

An alloy is a material made by combining two or more metallic elements to achieve properties no single metal can offer on its own – greater strength, for example, or better resistance to corrosion. Refractory alloys are based on elements such as tungsten, niobium and molybdenum, which have some of the highest melting points of any metals.

Their atoms are held together by strong chemical bonds and arranged in a stable crystal structure that resists deforming, even at extreme temperatures. Where conventional alloys begin to soften and slowly deform under constant stress, refractory alloys retain their strength, making them essential for components exposed to extreme heat, stress and radiation.

Most refractory alloys in service today were designed decades ago. They predate modern 3D printing of metal parts, also called additive manufacturing, and artificial intelligence.

To execute metal 3D printing, a laser or electron beam melts successive thin layers of metal powder.

This builds up a 3D part directly from a computer model by adding material layer by layer, rather than using molds or removing material from a solid block. 3D printing allows shapes that are impossible with traditional manufacturing methods. However, many current refractory alloys are difficult or impossible to manufacture reliably using these techniques.

This mismatch can slow the domestic production of new parts. To help address these manufacturing and supply-chain challenges, our team of materials researchers at Arizona State University and UNSW Sydney has formed a new international collaboration to redesign high-temperature alloys.

Old alloys in a new manufacturing world

Additive manufacturing allows defense and aerospace manufacturers to produce complex components locally, on demand and with far less material waste. In principle, it is ideal for producing replacement parts for aircraft, spacecraft and naval systems.

In practice, many refractory alloys crack, warp or develop internal defects when 3D-printed. Their compositions were optimized for casting or forging, not for the rapid melting and solidification involved in laser-based printing. In 3D printing, a laser melts and resolidifies metal thousands of times in quick succession, creating steep temperature gradients that generate enormous internal stresses. Several key refractory metals are brittle at room temperature and cannot absorb those stresses without cracking.

Redesigning these alloys using traditional trial-and-error methods would take decades.

Teaching computers to design new metals

Our alternative approach uses reinforcement learning, a form of artificial intelligence best known for training computers to master games such as Go or chess.

Designing a new alloy is a bit like mixing ingredients for a recipe, but at the atomic level. Instead of planning moves on a board, the AI system explores thousands of possible alloy recipes – for example, different combinations of chemical elements. Even tiny changes in the ingredients can completely change how the final material behaves.

The AI evaluates each candidate virtually against multiple criteria, including strength at temperatures above 1,800 degrees Fahrenheit (1,000 degrees Celsius) and resistance to damage caused by reacting with oxygen at high heat, as well as weight, cost and, crucially, whether it can be reliably 3D-printed.

Alloys that should perform well are rewarded, while those that fail are discarded. Over repeated cycles, the system learns which chemical combinations work best.

We can then manufacture and test the most promising AI-designed alloys in the laboratory. Their real-world performance feeds back into the model, steadily improving its predictions.

Strategic benefits beyond the laboratory

The implications of our research extend beyond the lab.

For defense agencies, faster materials development means quicker deployment for next-generation engines, hypersonic vehicles and systems that protect against heat. AI-designed alloys can be optimized for strength, heat resistance and manufacturability. For example, NASA’s GRX-810 alloy, designed with computational methods and 3D-printed, is 1,000 times more durable at high temperatures compared with traditional alloys.

Traditional manufacturing of refractory metals wastes up to 95% of the raw material through machining – removing unwanted material to create the precise shape – but 3D printing can bring that figure close to zero.

Our work is an international collaboration. At Arizona State University, the focus is on AI-driven computational design. UNSW Sydney’s facilities allow for high-temperature testing by looking at the metal’s microstructure and conducting additive manufacturing under realistic conditions.

Challenges still ahead

This approach is not without hurdles. One of the biggest is data scarcity: AI models learn from existing experimental results, and for refractory alloys, that data is limited. Far fewer alloys in this class have been systematically tested, compared with more common materials like steel or aluminum.

There are also practical constraints. Refractory metal powders suitable for 3D printing are expensive and difficult to source, and scaling up from small laboratory samples to full-sized components is difficult. An alloy that performs well as a thumbnail-sized test sample may behave very differently when printed as a large, complex part.

Finally, AI predictions must always be validated experimentally – and those experiments are costly and time-consuming. The system does not eliminate the need for rigorous physical testing.

A new model for defense-focused research

Our collaboration is in its early stages. We are currently building the AI model and assembling the experimental databases it will learn from. Later this year, the first candidate alloy compositions will be selected for 3D printing and laboratory testing. The results will feed back into the model.

We are also working with defense research agencies to ensure our work aligns with real-world needs and to lay the groundwork for larger-scale programs.

In an era where technological advantage increasingly depends on speed and adaptability, reimagining how we design the metals behind defense systems can improve the systems themselves.

Houlong Zhuang receives funding from Security and Defence PluS Alliance.

Vitor Rielli receives funding from Security and Defence PluS Alliance

– ref. AI and 3D printing help researchers create heat- and pressure-resistant materials for aerospace and defense applications – https://theconversation.com/ai-and-3d-printing-help-researchers-create-heat-and-pressure-resistant-materials-for-aerospace-and-defense-applications-273687

Source: The Conversation – USA – By Marcos Fernandez Tous, Assistant Professor of Space Studies, University of North Dakota

Throughout February 2026, people at the Kennedy Space Center got to witness an exciting sight: NASA’s behemoth Space Launch System rocket, SLS, standing on the launch pad, aimed toward the sky. The launch system has been key to the Artemis program – an ambitious series of missions intended to culminate in a sustained human presence on the Moon. NASA had initially planned to launch the second Artemis mission, which would take a crew of four people around the Moon, in February.

But as anticipation for launch built, an issue with the liquid propellant arose. A few days later, the SLS faced another problem, this time with the rocket’s upper stage, and had to roll back from the pad.

I’m an aerospace expert who is deeply passionate about aerospace technology and what it means for the U.S. and humanity’s future. I’ve been following the Artemis program’s timeline – February 2026 has represented a pivotal moment for U.S. spaceflight. Artemis II faced a number of delays, and NASA officials announced a shake-up of the larger program’s timeline.

Springing leaks

It started on Feb. 2, during Artemis II’s first wet dress rehearsal. During this major test, engineers assemble all components of the Space Launch System and fill its tanks with a combined 700,000 gallons of super-cold liquid hydrogen and liquid oxygen. These liquids act as the propellant for the rocket during launch.

During the test, the team detected a hydrogen leak at the interface of a 33‑foot-high (10 meters) service mast, the removable structure that brings the hydrogen and oxygen to the tank. They attributed the cause of the issue to moisture accumulated in the Teflon seal of two interfaces between that mast and the vehicle’s tank.

On the following day, NASA decided to postpone the launch until March 6. A new wet dress rehearsal would take place on Feb. 19 to verify everything was working as expected.

On the day of the second wet dress rehearsal, hydrogen operations proceeded smoothly, seemingly confirming plans for a March launch for Artemis II. Engineers at NASA likely breathed a sigh of relief, but they did so too early. A couple of days later another problem surfaced: They found the exploration upper stage was leaking helium. This upper stage of the rocket kicks in above 62 miles (100 kilometers), once the core stage expends all its propellant.

Because helium is essential for pressurizing cryogenic tanks and for purging the pipelines that will carry highly reactive liquid oxygen, the leak raised concerns.

Notably, these issues echoed the challenges SLS encountered ahead of its first launch for the Artemis I mission in 2022. Artemis I launched nearly six years after NASA’s original target date, ultimately accumulating 25 scrubbed or delayed launch attempts. Recurring hydrogen leaks in the tail service mast umbilical – a very similar issue – caused several of these delays.

Trouble with the SLS

On Feb. 25, the same day SLS rolled back to the vehicle assembly building for more work, NASA’s independent Aerospace Safety Advisory Panel released its annual report. This panel began in the aftermath of the January 1967 Apollo command module fire that claimed the lives of three astronauts, and NASA headquarters takes its assessments very seriously.

Citing the problems encountered on Artemis I and II, the panel warned of elevated risks for Artemis III, which planned to land on the Moon. They strongly recommended NASA restructure the program to reduce the likelihood of similar issues on future missions.

On Feb. 27, NASA made a major announcement: Artemis IV, scheduled for 2028, would now include a lunar landing. Artemis IV would then overlap with another landing planned in the same year, Artemis V.

NASA also confirmed that it plans to replace the exploration upper stage – the source of the helium leak – with a different upper stage known as the interim cryogenic propulsion stage. While the exploration upper stage was designed to use four engines, the interim cryogenic propulsion stage relies on a single engine.

The interim cryogenic propulsion stage previously flew on Artemis I, after which NASA intended to transition to the exploration upper stage for future missions. With the restructuring, however, the exploration upper stage program has been canceled, and NASA is returning to the interim cryogenic propulsion stage instead. With this change, Artemis appears to be going back to the basics and returning to simpler, proven hardware.

While Artemis II will not launch before April, the plan for the mission itself remains the same: It will still fly around the Moon.

But this new situation poses a question: If Artemis IV will now carry out the lunar landing, what will become of Artemis III, which had originally been planned as humanity’s return to the Moon? In essence, NASA is accelerating the schedule by adding more launches and tests before the first lunar landing attempt, and these changes are not necessarily to Artemis’ detriment.

A new timeline

NASA aims to increase the cadence of launches up to every 10 months starting in April 2026, incorporating fewer changes from mission to mission each time. This approach reduces technological uncertainty and stands in sharp contrast to the more than three‑year gap between the 2022 launch of Artemis I and the potential 2026 launch of Artemis II.

Artemis III will now become a tightly focused rehearsal mission lasting 30 days. NASA will test each mission component independently rather than checking them all together as a unit. Instead of visiting the Moon, Artemis III will remain closer to Earth.

NASA Administrator Jared Isaacman explained to CBS on Feb. 27 that Artemis III will launch the Orion spacecraft, which holds the astronaut crew, into low Earth orbit, where it will dock with one or both lunar landers – Blue Origin’s Blue Moon lander and SpaceX’s Human Landing System.

The Human Landing System will be a modified version of SpaceX’s Starship, the company’s enormous, superheavy spacecraft. The docking maneuver will help NASA confirm that the lander can handle the forces involved in connecting with Orion in space – essentially checking that the structure behaves as expected and can safely support the crew and their equipment.

Isaacman also pointed out that Artemis III may allow for NASA to test out the new spacesuit Axiom Space is designing for forays outside of the spacecraft.

The mission may also test navigation, communication, propulsion and life‑support systems. Interestingly, this series of tests aligns Artemis III more closely with the historical role of Apollo 7, which focused on evaluating the command and service module in Earth orbit.

In short, the new plans reshape Artemis III into a proof‑of‑concept mission intended to validate several critical systems before the two lunar landings planned for 2028 with Artemis IV and V. If successful, this approach should greatly improve the reliability of the missions that will finally return humans to the lunar surface. The revised timeline creates more opportunities to test and troubleshoot all the systems required for a safe landing.

It will also keep the missions more straightforward. With the same configuration across all missions, the tests will build on each other.

For now, you will need to wait a bit longer to watch humans walk in the Moon’s south pole region, where icy craters may hold clues to the early history of our solar system. But if February 2026 sets the tone, this next chapter will be anything but dull. Fasten your seat belts.

Marcos Fernandez Tous does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. With Artemis II facing delays, NASA announces big structural changes to the lunar program – https://theconversation.com/with-artemis-ii-facing-delays-nasa-announces-big-structural-changes-to-the-lunar-program-277169

Source: The Conversation – USA – By Eric Horstick, Associate Professor of Biology, West Virginia University

Being right- or left-handed is a familiar fact about yourself you likely don’t think about much on a day-to-day basis. However, your handedness affects how you interact with the world.

For many people, it determines how they brush their teeth, use tools, play sports, write, eat and much more. Simply try to enjoy a bowl of soup or sign your name with your nondominant hand to appreciate the impact a hand preference can have on your daily life.

Interestingly, this behavioral asymmetry is not unique to humans. Preferences for using the right or left hand, paw or eye exist in most species. For example, many primate species have individual left- or right-hand preferences for manual tasks. Similarly, different bird species have varying eye preferences for distinct visual tasks. Even the largest animal alive, the blue whale, shows a preference for the direction of its rolls during feeding. This inherent and often-overlooked feature of behavioral asymmetry is a widespread phenomenon in the animal kingdom.

The universality of behavioral asymmetry suggests that having an assigned hand, eye or other preference is beneficial. But depending on one hand for so many important tasks means that a single injury could be devastating. This paradox poses an important question: Why would having handedness be better for survival than not?

Insights from fish ‘handedness’

To address this question, scientists have tried to understand the genetics of handedness. While large-scale genetic studies in humans have identified dozens of genes associated with handedness, researchers also found that genetics alone only partially accounts for whether someone is left- or right-handed. This means behavioral asymmetry like handedness is likely the product of complex interactions between genetics, development and the environment.

For the past six years, my research lab has been interested in understanding behavioral asymmetry and how such behaviors get encoded in the brain. We primarily use larval zebrafish to explore the neural basis of behavioral asymmetry. These animals have transparent bodies and rapidly develop into adults in just a few days, making them ideal models to study. Additionally, the genetics and brain structure of zebrafish are highly similar to those of humans.

Fish have a form of handedness called motor asymmetry, which involves sustained periods of turning in the same direction. I had previously found that when light was cut off, larval zebrafish start circling in a leftward or rightward direction, sometimes for up to a minute or more. The fish would continue to preferentially turn in that same direction over the course of hours, days and even weeks, looking for a light source. This meant that vision drove their motor asymmetry.

Students in my lab recorded the zebrafish’s neural activity in response to loss of environment light – the trigger for motor asymmetry. They found a subset of approximately 60 neurons in the thalamus – a region of the brain that is evolutionarily conserved among vertebrates and involved in relaying sensory information – was functionally linked to motor asymmetry. Removing these neurons eliminated this motor asymmetry, suggesting a potential neural basis for where behavioral asymmetry is established in the fish brain.

When my lab repeated our experiments on five additional species of larval fish from around the world, we found similar motor asymmetry in response to light. Much like handedness in primates, it appears that handedness in fish is likely more of a rule than an exception.

However, we did find one exemption: the Mexican tetra, also known as cavefish. These animals are found in perpetually dark cave environments and are naturally blind. In collaboration with our colleagues at the Duboué Lab at Florida Atlantic University, we found that these animals showed no motor asymmetry.

These findings suggest that the universal nature of behavioral asymmetries are likely crucial responses to common challenges that different organisms encounter.

Behavioral asymmetry may solve challenges

Hurting your dominant hand does more than just ruin your softball or ultimate frisbee game. Handedness is associated with broad neural asymmetries in the brain that are linked to performance in language comprehension and working memory tasks. In addition, having atypical handedness – such as preferring different hands for different activities – is associated with a range of neurological conditions, including autism and attention-deficit/hyperactivity disorder.

Understanding why animals have behavioral asymmetries offers clues about how the environment influences broader cognitive function. If environmental challenges indeed drive handed behaviors, what problems does motor asymmetry solve for fish?

In nature, animals often circle when searching for something, such as a food source. For larval zebrafish, light is an important resource for their ability to see and capture prey. When we placed a light source at varying locations around them, the larval zebrafish start circling to quickly navigate into illuminated environments conducive to hunting. Based on our work, we hypothesize that the asymmetries in fish that allow them to search more efficiently work in parallel ways to those of other animals, like eye movement in birds or language comprehension in people.

Prior research has suggested that brain asymmetries improve cognitive performance by reducing competition between the two sides of the brain. Our work supports these hypotheses by showing how, for zebrafish, motor asymmetry provides a default response to find light and efficiently catch a needed snack.

With a helping hand from fish handedness, researchers are getting a clearer idea of the universality of behavioral asymmetry and how the environment may be shaping the brain so that one hand, or fin, provides an advantage in daily life.

Eric Horstick receives funding from the National Institutes of Health and National Science Foundation.

– ref. I study why zebrafish larva prefer to circle left or right, to understand how and why human brains encode right- and left-handedness – https://theconversation.com/i-study-why-zebrafish-larva-prefer-to-circle-left-or-right-to-understand-how-and-why-human-brains-encode-right-and-left-handedness-274578

Source: The Conversation – USA – By Deyanira Nevárez Martínez, Assistant Professor of Urban and Regional Planning, Michigan State University

A bureaucratic shift in Washington is threatening to undo years of progress in Detroit’s fight against homelessness, potentially forcing thousands of the city’s most fragile residents back onto the streets.

In November 2025, the U.S. Department of Housing and Urban Development revised how it would allocate funding through its flagship homelessness program, the Continuum of Care.

The change reduced the share of funding available for permanent subsidized housing and increased funding for transitional short-term housing.

HUD officials described the shift as a move away from a “housing first” model toward a “treatment first” approach that emphasizes participation in services, such as drug addiction disorder treatment, before or alongside housing placement.

The administration has argued that this promotes self-sufficiency. Critics contend that stable housing is the foundation that makes treatment and recovery possible.

The policy revision has been challenged in court by 20 states, including Michigan, as well as city and county governments and advocacy organizations. They argue it could destabilize individuals and families across the country, state and here in Detroit.

I am an urban and regional planning scholar who studies housing policy, and I serve on the research council of the National Alliance to End Homelessness.

In December 2025, I joined 77 other homelessness researchers who sent a letter to Congress analyzing the likely impacts of HUD’s revised funding approach. That analysis draws on decades of peer-reviewed research evaluating which housing interventions reduce homelessness and which do not.

That same month, a federal judge issued a preliminary injunction that temporarily pauses HUD’s efforts to shift funding away from permanent supportive housing.

HUD officials stated that the agency intends to apply the changes in future funding rounds, once the order is no longer in effect.

Homelessness in Detroit

Detroit’s homelessness crisis is both long-standing and worsening.

The number of people who experience homelessness in Detroit, Hamtramck and Highland Park increased by about 16% from 2023 to 2024, with roughly 1,725 people experiencing homelessness on a single January night, including hundreds of families. Children in particular have been hit hard by this crisis. One data snapshot shows 2,579 children reported being doubled up, staying in a shelter, staying in a hotel or motel or being unsheltered. This was a record number for the Detroit Public Schools Community District.

While permanent supportive housing has strong outcomes for those who receive it, overall homelessness has continued to increase due to rising rents, economic instability and the limited housing supply, which has historically outpaced the number of available supportive units.

Detroit’s homelessness response system is coordinated through the federally funded local Continuum of Care led by the Homeless Action Network of Detroit.

In recent years, Detroit has taken steps to strengthen coordination, expand shelter capacity and increase housing placements. But the system heavily depends on federal funding to provide permanent supportive housing.

What could change in federal homelessness funding

The Continuum of Care program began in 1994 and was later codified in 2009 by the Homeless Emergency Assistance and Rapid Transition to Housing Act. It is the largest federal funding stream dedicated to addressing homelessness in the United States.

Last year alone, Detroit received US$40 million from the HUD program.

Those funds pay for emergency shelters, transitional housing and rapid rehousing programs – which provide temporary rental assistance and the assistance of a social worker, without preconditions – and permanent supportive housing.

Like other cities nationwide, Detroit has built its homelessness response system around HUD’s funding priorities.

For more than a decade, HUD has emphasized permanent housing. A strong body of evidence shows that stable housing leads to better long-term outcomes than temporary programs.

Prior Continuum of Care funding cycles allocated roughly 85% to 90% of funds to permanent housing, according to the National Alliance to End Homelessness.

The revised funding priorities announced in late 2025 would substantially reduce that share and redirect funding toward transitional housing and short-term interventions.

According to the Homeless Action Network of Detroit, this means that Detroit area providers could go from about $34 million per year allocated for permanent supportive housing under the current allocation to no more than about $11 million under the new priorities.

Local advocates warn that capping permanent housing at roughly 30% of Continuum of Care dollars would drastically reduce the number of supportive units available and place hundreds of households at risk of returning to homelessness.

Why permanent supportive housing matters

Permanent supportive housing is one of the most rigorously studied homelessness interventions in the United States.

It is an evidence-based intervention that provides long-term rental assistance paired with voluntary supportive services for people who have experienced chronic, or repeated, homelessness, particularly those with disabilities or chronic health conditions.

Under the current Continuum of Care framework, households typically pay no more than 30% of their income toward rent, with the subsidy covering the remainder. Assistance can continue as long as eligibility criteria are met.

Programs also offer staff to help with coordination of health care and behavioral health services and assistance identifying and applying for relevant benefits to promote long-term housing stability. Tenants hold standard leases and have the same legal protections as other renters.

Research shows that permanent supportive housing using a housing-first approach consistently reduces homelessness and improves health outcomes for people with disabilities.

Greater investment in permanent supportive housing is also linked to reductions in chronic homelessness, meaning individuals or families who have been homeless for long periods or repeatedly over time.

A long-term study published in Social Service Review in 2014 found that communities that increased permanent supportive housing capacity experienced measurable declines in chronic homelessness over time.

Local data from the Detroit Continuum of Care indicate that at least 160 new permanent supportive housing units have been made available in the past year, and another 235 units are projected for 2026. These units help people exit homelessness and maintain stable homes amid rising rents and affordability challenges.

How transitional housing compares

Transitional housing typically requires residents to participate in supportive services or programming as a condition of stay. This can include regular meetings with a social worker, employment readiness classes, substance use treatment or financial literacy workshops, for example.

The model is often used for survivors of domestic violence or young adults aging out of foster care. While transitional housing can provide short-term stability and support during these transitions, it differs from permanent supportive housing in that it is time-limited and may require program compliance as a condition of continued residency. Transitional housing placements typically last from about six months up to two years.

However, research consistently finds that transitional housing is less likely than permanent housing to produce long-term housing stability. This is particularly the case for families and people with disabilities.

HUD’s Family Options Study in 2016 found that families offered permanent housing experienced significantly better long-term housing stability than those offered transitional housing, despite transitional housing costing more per household.

Follow-up research conducted by the Urban Institute, a nonprofit organization that studies economic policy, similarly found that many families who leave transitional housing once their time limit expires struggle to maintain stable housing. These findings are especially relevant for individuals with disabilities, chronic illnesses or mental health conditions, all groups that are typically prioritized for permanent supportive housing.

Why Detroit is especially vulnerable

Research shows that housing instability increases reliance on emergency services such as shelters, hospitals and public safety systems. This drives up taxpayer costs and additionally strains already overextended local services.

Detroit area homelessness service providers are pushing back against the potential federal changes, which they identify as “radical.”

In response, many organizations are turning to state and philanthropic partners for support while continuing to develop housing locally to help offset possible reductions in federal funding.

Deyanira Nevárez Martínez has received funding from the State of Michigan, the Latino Policy and Politics Institue at UCLA, the Institute for Research on Poverty at the University of Wisconsin-Madison, and the Freedom Together Foundation (formerly the JPB Foundation). She is an Assistant Professor of Urban and Regional Planning at Michigan State University and is an elected member of the Lansing City Council representing ward 2.

– ref. Housing First helps people find permanent homes in Detroit − but HUD plans to divert funds to short-term solutions – https://theconversation.com/housing-first-helps-people-find-permanent-homes-in-detroit-but-hud-plans-to-divert-funds-to-short-term-solutions-274272

Source: The Conversation – USA – By Sarah Burns, Associate Professor of Political Science, Rochester Institute of Technology; Institute for Humane Studies

Article 1 of the U.S. Constitution gives Congress the power to declare war, not the president. But most modern presidents and their legal counsel have asserted that Article 2 of the Constitution allows the president to use the military in certain situations without prior congressional approval – and have acted on that, sending troops into conflicts from Panama to Libya, with no regard for Congress’ will.

Congress has for the most part registered only feeble and ineffective opposition to such executive action. The current move in Congress to deny President Donald Trump the ability to continue the war with Iran – led by Democrats, but with some Republican support – will likely fail, as have previous efforts during other conflicts.

But there was a time when Americans saw Congress stand up to a president who unilaterally took the country to war.

It was at the tail end of the Vietnam War, when Congress passed the War Powers Resolution of 1973, asserting that it was legislators – not the president – who had the power to declare war.

Once it passed both houses, President Richard Nixon vetoed it, claiming it was unconstitutional.

In response, the legislative branch overturned the veto with the two-thirds majority vote needed to prevail.

Compared to Congress’ limp response to Trump’s actions in Iran, and its similar failure to assert itself during Trump’s military action in Venezuela, it was a breathtaking act of legislative assertion.

Congress asserts itself

When they debated the War Powers Resolution, members of Congress were seeing the erosion of their control over the decision to engage in military operations large and small. With a strong bipartisan consensus, they determined they had to collectively use their powers, including the power of the purse, to thwart executive overreach.

Congress’ actions came in response to the growing protests against the Vietnam War in general and Nixon’s decision to expand the war by sending U.S. troops to invade the neutral country of Cambodia to disrupt the supply lines of the Viet Cong, the communist guerrilla force that accounted for a large number of the 58,000 Americans killed in the war.

Nixon had begun covert carpet bombing of Cambodia in 1969, and then announced in 1970 that he would send ground troops into the country the next year.

Congress – and the country– reacted extremely negatively. Members of Congress collaborated across party lines to draft legislation in an attempt to assert their power. It was a slow process, however, involving long periods of deliberation.

They used many different methods to attempt to constrain the president. Within months of the introduction of troops to Cambodia, Congress attempted to pass amendments that would restrict his ability to invade neighboring countries. Prompted by protesting and the illegal actions in Cambodia, Congress began crafting legislation that would draw down troops in Vietnam.

With these moves, lawmakers placed immense pressure on the president. This eventually led to the drafting and eventual signing of the peace agreement ending the Vietnam war in 1973.

This was not enough for Congress, however.

Rules – and flexibility

Congress wanted to create a document ensuring presidents could not unilaterally make war. They wanted legislative consultation.

They intended the War Powers Resolution to act as a permanent constraint. So, in the resolution they spelled out the specific actions in which presidents can start a conflict:

• First, if there is an invasion of the United States, the president can respond. In this instance, the president can act prior to congressional authorization.

• Second, if Congress provides an “Authorization for the Use of Military Force,” the president can assume he has authorization – but only as long as it is in effect.

• Finally, if Congress declares war, the president can act.

Lawmakers did, however, provide some flexibility. In the War Powers Resolution, they said a president can initiate and carry out hostilities for 60 days and has a further 30 days to draw down the troops. Once the executive has initiated hostilities, Congress must receive information about that action within 48 hours.

This opens the door for presidents to engage in smaller-scale or short operations without stepping outside the lines set in the law.

Presidents from both parties have availed themselves of this flexibility. As far back as 1975, when President Gerald Ford rescued the SS Mayaguez, the merchant ship captured by Cambodia’s Khmer Rouge, presidents have acknowledged the law and dutifully reported their military actions to Congress.

Like his predecessors, Trump sent a letter to Congress after his June 2025 missile attacks against Iran, as well as at the start of the currently open-ended conflict.

Presidents since the passage of the War Powers Resolution have not, however, acknowledged that they have to get congressional approval of their actions, with few exceptions. Predominantly, without congressional approval, they limit their actions to the 60-to-90-day window.

President Barack Obama, however, attempted to circumvent the window when his bombing campaign in Libya in 2011 dragged on, as well as when he bombed the Islamic State group in 2014. In the first instance, he claimed the War Powers Resolution did not apply. In the second, he claimed each bombing campaign was discrete, rather than part of a larger campaign.

Exploiting authorizations

The balance of power between the legislative and executive branches changed considerably with the passage of the 2001 Authorization for Use of Military Force related to the Sept. 11, 2001, terrorist attacks, and the 2002 Authorization for Use of Military Force that gave legislative permission for President George W. Bush to invade Iraq.

Because Congress did not put sunset dates into these authorizations, subsequent presidents Obama, Trump and Joe Biden used those same authorizations for a host of later military actions in the Middle East and elsewhere.

And legislators are deeply divided in the current discussions about demanding the cessation of hostilities against Iran.

Republican House Speaker Mike Johnson says that limiting the president at this time is “dangerous.” Former congresswoman Marjorie Taylor Greene – who has fallen out of favor with Trump’s MAGA base and the president himself – took the opposing view, posted on social media, “Now, America is going to be force fed and gas lighted all the ‘noble’ reasons the American ‘Peace’ President and Pro-Peace administration had to go to war once again this year, after being in power for only a year.”

Has the U.S. entered a moment when members of Congress reassert themselves the way they did at the tail end of the Vietnam war?

It is possible that they will follow James Madison’s advice about the power relationship between Congress and the president. Writing in the Federalist Papers, Madison said that “ambition” has “to counter ambition.” He continued, “The interest of the man must be connected with the constitutional rights of the place. It may be a reflection on human nature, that such devices should be necessary to control the abuses of government.”

As I explain in my book about congressional war powers, the constitutional system creates an invitation to struggle. Now, as the U.S. wages war on Iran, Congress must decide whether it wants to struggle, as it did during the Vietnam War, or remain compliant and in the president’s shadow.

Sarah Burns has received funding from the Institute for Humane Studies.

– ref. Congress once fought to limit a president’s war powers − more than 50 years later, its successors are less willing to assert their authority – https://theconversation.com/congress-once-fought-to-limit-a-presidents-war-powers-more-than-50-years-later-its-successors-are-less-willing-to-assert-their-authority-277435

Source: The Conversation – USA (2) – By Dylan Spencer, Assistant Professor of Criminology, Georgia Southern University

In late February 2026, the Panamanian government took control of two ports in the Panama Canal that had been operated by a Hong Kong conglomerate for two decades. The move is the latest in a long-simmering legal battle after Panama’s high court voided the company’s contracts.

Far from just a local dispute, however, the episode has drawn in the United States and China, whose competition over global ports and trade routes has intensified in recent years, including in the crucial Panama Canal Zone, where China’s presence has repeatedly drawn the ire of the Trump administration.

Chinese firms now own or operate terminals at more than 90 ports worldwide, including many of the busiest. The network spans Africa, Europe, the Middle East and Asia, with growing activity in South America.

The scale of China’s involvement in overseas ports has fueled debate over whether these investments are purely commercial or serve broader strategic goals.

Much of that debate has relied on case studies and politicized headlines, including in the case of the Panama Canal. But understanding where these ports are located, and whether there are consistent patterns in the countries that host them, is important given that disruptions to global shipping lanes can reverberate across the world economy.

In a recent study, we – researchers in maritime security, global infrastructure and trade – built the first global database of Chinese-affiliated ports and analyzed 133 coastal countries to understand why some host Chinese port investments while others do not.

We found that China’s overseas port expansion is not random. Far from being driven primarily by general business climate measures, the investments cluster near maritime chokepoints and piracy-prone shipping corridors, with more modest evidence that resource-rich countries are also more likely to host these ports.

The importance of chokepoints

Some sea routes are more important than others. The Suez Canal, the Strait of Hormuz and the Strait of Malacca are examples of chokepoints – narrow routes through which large volumes of global trade and energy shipments must pass.

In our findings, countries near primary or secondary chokepoints, such as Panama or countries bordering the Dover Strait, such as France, were substantially more likely to host a Chinese-affiliated port. Put simply, proximity to critical trade bottlenecks strongly predicts Chinese investments.

This makes economic sense. China depends heavily on maritime trade to sustain economic growth. And ports near chokepoints sit along the world’s most sensitive shipping corridors and offer long-term commercial access in strategic locations.

Despite concerns in the West that Beijing is developing ports for military reasons, not every port is a naval base in disguise.

Most Chinese-affiliated facilities are commercial terminals. However, commercial infrastructure can still have strategic value. China’s first overseas military logistics base in Djibouti sits alongside the Chinese-operated Doraleh port complex. A report from the Congressional Research Service notes that the facility supports naval operations and regional access in the western Indian Ocean.

That does not make other Chinese-owned or operated ports military installations. But control over terminals, logistics platforms, and supply chain data can shape economic and security relationships over time.

The role of piracy and resources

The same corridors in which Beijing is concentrating port investment are also hot spots for maritime crime. In separate research, we found that seaports can facilitate illegal, unreported and unregulated fishing when oversight is weak. Our latest findings show that Chinese-affiliated ports are more common in countries already experiencing piracy and maritime insecurity.

That overlap does not mean ports cause illicit activity, but it shows these investments often occur in higher-risk maritime environments.

One of the most surprising findings from our study was the relationship between piracy and port investment.

Between 1991 and 2018, thousands of piracy incidents were recorded worldwide. But rather than avoiding risky waters, Chinese-affiliated ports are more common in countries experiencing higher levels of piracy.

Why invest in unstable corridors? One explanation is that piracy signals where trade routes are both vulnerable and valuable. Investing in ports in areas such as the Gulf of Guinea or parts of Southeast Asia may help Beijing protect its shipping interests. In this sense, piracy may signal not just risk but opportunity.

We also examined natural resource wealth of port host nations using a broad measure that includes extractive mineral and agricultural resources. We found modest evidence that countries with higher resource levels were more likely to host at least one Chinese-affiliated port, though this relationship was not consistent across all models.

Some commonly cited explanations as to where and why China invests in ports did not hold up in our analysis.

Broad measures of business climate and governance, such as ease of doing business or institutional stability, were not consistent predictors of Chinese-affiliated port presence.

This suggests that geography and maritime risk factors may matter more than general economic or governance indicators.

Broader implications

Whatever the motivations behind Chinese investments, their implications extend beyond local trade and logistics.

Ports are no longer just local infrastructure projects. They are nodes in global supply chains and increasingly in geopolitical competition.

And while not every investment signals a covert military ambition, it would be naive to treat all port projects as politically neutral.

---

Read more:
China is losing ground in Latin America

---

Recent U.S. policy responses reflect these growing concerns. In early 2026, the White House outlined a plan to strengthen the U.S. shipping industry and reduce reliance on foreign-controlled maritime infrastructure. The administration has also taken a closer look at foreign involvement in key facilities in the Western Hemisphere, including ports linked to the Panama Canal.

Such moves suggest that control over maritime infrastructure is no longer viewed in Washington as just a commercial issue but increasingly as a matter of economic and national security.

And as the map of countries with Chinese-affiliated ports suggests, Beijing’s investments are following the world’s most consequential trade routes not by accident, but by design.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Far from random, China’s global port network is clustering near the world’s riskiest trade routes – https://theconversation.com/far-from-random-chinas-global-port-network-is-clustering-near-the-worlds-riskiest-trade-routes-274934

Source: The Conversation – USA (2) – By Leila Gautham, Lecturer in Economics, University of Leeds

When economists track inequality, they typically focus on income and spending.

But a significant share of the services that families actually consume – meals cooked at home, child care, housecleaning and lawn mowing – is produced by unpaid labor that never appears in these conventional measures.

As economists who study caregiving and inequality, we wanted to know whether accounting for unpaid work at home might change our understanding of inequality in American living standards – the gap between what richer and poorer Americans can actually afford to consume.

To find out, we conducted a study, published in the March 2026 issue of the Journal of Public Economics, in which we estimated the dollar value of unpaid housework and child care and added it to standard measures of income and spending for U.S. households from 1965 to 2018. Economists call these broader measures “extended income” and “extended consumption.”

We found that unpaid work used to significantly cushion inequality through the provision of many services. But we also determined that this cushion has been thinning for 50 years. Our findings indicate that the inequality in living standards has grown more than standard data suggest.

Counting unpaid work reduces inequality

To visualize these findings, consider the financial situation faced by two families.

While both have two adults and two children, their income from their salaries and other cash flows – including everything from stock dividends to Social Security benefits – is different. One has two earners bringing in a total of US$150,000. The other has a single breadwinner making $110,000 and a stay-at-home spouse. The lower-income family gets 45 more hours per week of unpaid chores done.

If every hour of those chores were worth $17, the typical wage for a housekeeper, that unpaid work would be worth roughly $39,780 a year. Factor it in, and the gap between the two families shrinks from $40,000 to just $220.

Extended income, the economic term that includes not just what’s in your paycheck but the value of doing the laundry, home repairs and other unpaid work yourself for your own benefit, tends to be more equally distributed than earned income.

The reason for this consistency is straightforward: Rich and poor families generally devote about the same amount of time to housework and child care.

A shrinking buffer

Because we valued everyone’s unpaid hours at the same wage in our study, adding unpaid work to income narrowed the gap between the top and the bottom somewhat.

But we also found evidence that this equalizing effect is eroding.

Between 1965 and 2018, the average amount of time that Americans devoted to unpaid chores at home fell, driven by changes in what women did. Their average number of hours fell from 37 to 24 per week. Meanwhile, men increased the time they spent on unpaid chores a little: Their number of weekly unpaid hours of work rose from 12 in 1968 to 15 in 2018.

To be clear, we did not try to figure out why these hours of unpaid work fell. Among the many reasons for the change could be the large increase in women’s employment and the growth of time-saving technology, such as dishwashers.

Lowest-income families hit hardest

We studied these shifts by combining three national datasets: time diary surveys from the American Heritage Time Use Study, income data from the Current Population Survey and expenditure data from the Consumer Expenditure Survey.

To put a dollar figure on unpaid work, we valued each hour at what U.S. housekeepers typically earn in a particular year.

The decline in unpaid work hit low-income households hardest – not because they cut more hours, but because unpaid work made up a much larger share of their total income.

We found that the income gap between households near the top and those near the bottom between 1965 and 2018 grew around 40% using conventional measures. Once we added unpaid work, this gap grew by 66%. For household spending, the contrast is similar: conventional inequality barely budged – up 4%. When we incorporated the value of unpaid work at home, inequality grew by 18%.

Overall, we determined that a typical U.S. family’s extended income grew 40% from 1965 to 2018. That was a much slower pace than the 69% growth in the income they earned from their paid work and other cash flows over the same period.

Who lost the most

Conventional data suggest that the gap between middle-income and poor households was generally stable during this period. Once we accounted for unpaid work, however, that is no longer true: This gap grew substantially.

Single-parent families – mostly headed by single mothers – were hit especially hard. Their income from paid employment rose sharply, but this came with large declines in the value of their unpaid work at home.

While they could afford to spend more on purchased goods and services, once unpaid work is factored in, single parents saw no net improvement relative to married parents.

What it means

The roughly 20-percentage-point increase in the share of women working outside the home over the past six decades was driven by expanded opportunity and economic necessity.

It has brought enormous economic benefits to those women and their families. But it has also meant that families – especially those with the least income – lost a cushion of services that women used to do in their own homes.

Our findings suggest that looking only at changes in income and spending can exaggerate improvements in living standards for the lowest-income Americans over the past five decades.

When you do fewer hours of chores that need to be done, you wind up paying other people to do them for you, and that costs money.

Otherwise, you have to make do with fewer services than you had before.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. When unpaid cooking, cleaning and child care get a dollar value, income inequality in the US shrinks – but the gap has grown since 1965 – https://theconversation.com/when-unpaid-cooking-cleaning-and-child-care-get-a-dollar-value-income-inequality-in-the-us-shrinks-but-the-gap-has-grown-since-1965-275499

Source: The Conversation – USA (2) – By Matt Wilkinson, Associate Professor of Sociology, Coastal Carolina University

A #MeToo-style reckoning appears to be unfolding within Brazilian jiu-jitsu.

In February 2026, Brazilian jiu-jitsu legend Andre Galvao was accused of sexual misconduct by multiple women, including a teenager who had trained at Atos Jiu Jitsu, the school Galvao co-founded in San Diego in 2008 that now boasts academies around the world.

The backlash was swift: Multiple gyms and high-profile athletes affiliated with Atos severed ties with the school.

Galvao dismissed the accusations as “false rumors” and stated he is “taking the proper legal steps to protect the integrity” of Atos.

On Feb. 6, 2026, however, Atos Jiu Jitsu announced it had removed Galvao from his leadership posts. Many other gyms and athletes without a direct connection to Galvao or Atos nonetheless took the news as an opportunity to post messages about their commitment to safety for their gym members.

In a sport that has long struggled with addressing sexual harassment and misconduct, we see the widespread condemnation of Galvao as a watershed moment. And it comes on the heels of research we conducted to better understand the unique challenges that female martial artists face.

A sport built on trust

For those unfamiliar with the sport, Brazilian jiu-jitsu is a martial art focused on grappling and ground fighting – think wrestling, but with submission techniques like arm bars, shoulder locks and chokeholds. It’s essentially the grappling on the ground part of UFC, minus the punches and knee strikes.

Although almost all Brazilian jiu-jitsu competitions are split by gender, sparring and drilling routinely happen between men and women. It typically involves physical contact, usually between two people with different levels of strength and experience.

For these reasons, trust, restraint and respect are essential.

When your opponent successfully applies a technique that limits your movement and from which you cannot escape, you “tap out” to signal that you have accepted defeat. When you submit, your opponent is obligated to let go immediately to avoid causing injury or unconsciousness.

Much of the attention on sexual harassment in the sport has historically focused on incidents of assault. And a review of news coverage between 1989 and 2018 identified 177 incidents of martial arts coaches being convicted of sexual offenses.

But the kind of harassment that may not rise to the level of a crime in most countries – more pervasive and more subtle, but nonetheless insidious – has largely remained unacknowledged in Brazilian jiu-jitsu.

Blissful ignorance or something more insidious?

Whether it’s through inappropriate or sexualized comments both on and off the mat – or through unsolicited remarks about their bodies or appearance – women encounter a far different training environment than their male counterparts.

This is what we wanted to explore in our own research.

In 2021, we conducted a survey on martial arts participation that generated responses from 289 martial artists – 209 men, 77 women and 2 nonbinary people – in the U.S. and around the world. Most of them listed Brazilian jiu-jitsu as their primary art.

In the analysis, 43% of our survey respondents – 51% of women and 40% of men – indicated that they were aware of harassment in their martial arts community, which ranged from bullying to sexual harassment, to sexual assault.

But harassment was just one issue raised. The survey revealed a wider problem of “gender blindness” in martial arts, which involves simply ignoring or overlooking the impact that gender can have on participation, practice and performance.

When asked, “What does it mean to be a woman in martial arts?” 62% of men responded with statements that actively downplayed or ignored the ways gender shapes the sport. For example, one man noted that “the beauty of martial arts” is that “anyone can do it,” regardless of age, ability, “gender, shape or size.”

By contrast, nearly two-thirds of women in our survey indicated that being a woman in martial arts does, in fact, matter. They said they had fewer training opportunities, revealed that they felt they needed to work twice as hard to prove themselves, and highlighted safety concerns.

It isn’t clear whether the gender blindness among male martial artists reflected optimism, ignorance or something else. But the impact is the same: Women see gender as central to their experience. Men generally perceive gender to be irrelevant to the sport, and they don’t realize what women deal with on a day-to-day basis.

Unfortunately, gender blindness isn’t just relegated to Brazilian jiu-jitsu. Long studied by sociologists and gender scholars, it’s a pattern that lays the groundwork for abuse across all types of sports. And where gender blindness exists in combination with rigid hierarchies, it enables abuses of power and a culture of silence.

When people refuse or fail to recognize how gender shapes the experiences of women in sports, it becomes much harder to address conditions that allow for harassment and assault to occur. For example, when inappropriate contact or groping during training is dismissed as merely “accidental” or minimized as someone being “handsy,” it signals that this behavior is trivial rather than harmful. And it creates an environment where women – and men – may feel uncomfortable coming forward or speaking out.

Some prominent figures in the Brazilian jiu-jistu community are making this connection.

In a recent postmatch victory speech, Brazilian jiu-jitsu champion and coach Adele Fornarino issued a call to action. Criticizing the hierarchical structure of the sport, she emphasized that people in positions of power are taking advantage of the vulnerable and called for “no more blissful ignorance.”

What comes next?

In jiu-jitsu, men have traditionally held positions of power. By and large, they’ve been the owners of gyms, the instructors leading classes, the holders of black belts.

But this has been changing: The adult black belt women’s division at the 2025 International Brazilian Jiu-Jitsu Federation World Championships saw a 40% increase in participants over the previous year. By contrast, participation in the men’s division decreased by 18%.

More women are standing side by side with men at the front of the class as leaders and experts. As a result, it’s possible that many male martial artists are more likely to respect, trust and see their female peers as equals.

When they live up to what they can be, the martial arts are a place where men and women struggle together and protect each other. They can develop unique friendships, cultivate empathy and practice mutual support.

Men and women having the opportunity to train together in the same gym can lead to what German sociologist Max Weber called “verstehen”: the kind of understanding that comes from working closely enough with someone to grasp the fears, aspirations and experiences that drive them. Spaces that allow for that depth of connection are all too rare.

We see the swift denunciation of Galvao, a legend in the sport, as a sign that Brazilian jiu-jitsu may be progressing toward a culture centered on care, concern and restraint instead of dominance and power.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Brazilian jiu-jitsu is having its #MeToo moment – https://theconversation.com/brazilian-jiu-jitsu-is-having-its-metoo-moment-275916