For decades, astronomers have wondered what the very first stars in the universe were like. These stars formed new chemical elements, which enriched the universe and allowed the next generations of stars to form the first planets.

The first stars^[1] were

Portable air cleaners aimed at curbing indoor spread of infections are rarely tested for how well they protect people – and very few studies evaluate their potentially harmful effects. That’s the upshot of a detailed review^[1] of nearly 700 studies that

U.S. state legislatures are where the action is for placing guardrails around artificial intelligence technologies, given the lack of meaningful federal regulation. The resounding defeat in Congress^[1] of a proposed moratorium on state-level AI regulation means

WASHINGTON — Defense Secretary Pete Hegseth has fired a general whose agency’s initial intelligence assessment of damage^[1] to Iranian nuclear sites from U.S. strikes angered President Donald Trump^[2], according to two people familiar with the decision and a White House official.

Lt. Gen. Jeffrey Kruse will no longer serve as head of the U.S. Defense Intelligence Agency, according to the people, who spoke on condition of anonymity because they were not authorized to discuss it publicly.

The firing is the latest upheaval in the U.S. military and intelligence agencies, and comes a few months after details of the preliminary assessment leaked to the media. It found that Iran’s nuclear program has been set back only a few months by the U.S. strikes, contradicting assertions from Trump^[3] and Israeli Prime Minister Benjamin Netanyahu.

The Republican president, who had pronounced the Iranian program “completely and fully obliterated," rejected the report.

In a news conference following the June strikes, Hegseth lambasted the press^[4] for focusing on the preliminary assessment but did not offer any direct evidence of the destruction of Iranian nuclear production facilities.

“You want to call it destroyed, you want to call it defeated, you want to call it obliterated — choose your word. This was an historically successful attack,” Hegseth said then.

Kruse's ouster was reported earlier by The Washington Post.

Trump has a history of removing government officials whose data and analysis he disagrees with^[5]. Earlier this month, after a lousy jobs report, he fired the official in charge of the data. His administration has also stopped posting reports on climate change^[6], canceled studies on vaccine access^[7] and removed data on gender identity^[8] from government sites.

The firing of the DIA chief culminates a week of broad Trump administration changes to the intelligence community and shakeups to the military leadership. The Office of the Director of National Intelligence — which is responsible for coordinating the work of 18 intelligence agencies, including DIA — announced that it would slash its staff and budget^[9].

The Pentagon announced this week that the Air Force’s top uniformed officer, Gen. David Allvin, planned to retire^[10] two years early.

Hegseth and Trump have been aggressive in dismissing top military officials, often without formal explanation.

The administration has fired Air Force Gen. CQ Brown Jr.^[11] as the chairman of the Joint Chiefs of Staff, as well as the Navy’s top officer, the Air Force’s second highest-ranking officer, and the top lawyers for three military service branches.

In April, Hegseth fired Gen. Tim Haugh^[12] as head of the National Security Agency and Vice Adm. Shoshana Chatfield^[13], who was a senior official at NATO.

No public explanations have been offered by the Pentagon for any of these firings, though some of the officers were believed by the administration to endorse diversity, equity and inclusion programs.

National Guardsmen^[1] patrolling Washington, D.C., as part of President Donald Trump's purported crackdown on crime will soon be armed, the Pentagon said Friday.

"At the direction of the secretary of defense, JTF-DC members supporting the mission to lower the crime rate in our nation's capital will soon be on mission with their service-issued weapons, consistent with their mission and training," the Pentagon said in an emailed statement, using an acronym for Joint Task Force-District of Columbia.

The statement provided few other details on the decision to arm Guardsmen, including what weapons they will carry, when exactly they will start carrying weapons, and why they need to be armed.

Read Next: Fire Extinguished After 12-Hour Fight on USS New Orleans Off Okinawa^[2]

Asked separately about the decision, a spokesperson for the task force would say only that they were aware of reports but that, as of right now, Guardsmen are not armed.

The decision to allow Guardsmen to carry weapons on the streets of D.C. marks an escalation in Trump's policing takeover of the capital. When Trump first announced he would deploy the Guard in D.C., officials had stressed that troops would not be armed.

Incorrectly claiming D.C. is facing a crime wave, Trump last week mobilized 800 members of the D.C. National Guard, deployed hundreds of federal law enforcement members on city streets, and moved to federalize the local D.C. police force.

The Guard deployment^[3] has since ballooned to about 2,000 troops as Republican governors from six states have sent hundreds of members of their National Guards to the capital.

Guardsmen have mostly been patrolling^[4] tourist areas not known for high crime rates, such as the National Mall and a transit hub near Capitol Hill called Union Station, as well as several Metro stations throughout the city. In recent days, they have also been spotted expanding across the city in areas popular for dining and socializing, such as near the Nationals Park baseball stadium.

In its statement on the decision to authorize carrying weapons, the Pentagon said the commander of the D.C. National Guard "retains the authority to make any necessary force posture adjustments in coordination with the D.C. Metropolitan Police and federal law enforcement partners."

"The D.C. National Guard remains committed to safeguarding the District of Columbia and serving those who live, work and visit the District," the statement said.

The federal takeover of D.C. has become a major talking point of the Trump administration, with Attorney General Pam Bondi posting daily updates on social media about total arrests and top administration officials doing photo ops with troops and police.

Trump himself, after suggesting earlier in the day he would be going on patrol with police and troops, on Thursday evening briefly visited a Park Police station to address federal law enforcement officers and Guardsmen and hand out pizza.

"You got to be strong. You got to be tough," Trump, who also suggested the Guard deployment could last six months, told the group. "You got to do your job. Whatever it takes to do your job."

Trump has also suggested he will continue escalating by deploying troops to other Democratic-run cities such as Chicago and New York City, and possibly use active-duty troops.

"We haven't had to bring in the regular military, which we're willing to do if we have to," Trump told reporters in the Oval Office on Friday. "And after we do this, we'll go to another location, and we'll make it safe also."

Active-duty troops are generally banned from conducting law enforcement on U.S. soil under a law called the Posse Comitatus Act, though there are exceptions such as invoking a separate law called the Insurrection Act. During his first term, Trump toyed with invoking the Insurrection Act amid racial justice protests in 2020, but was talked out of it at that time.

The D.C. deployment follows a pattern of Trump increasingly pulling the military into his political agenda while claiming to be combating lawlessness. Earlier this year, Trump deployed thousands of Guardsmen and hundreds of Marines to Los Angeles in response to protests against immigration raids, a move that sparked a lawsuit by state officials arguing he usurped their authority over the Guard.

Local D.C. officials have pushed back on Trump's characterization of the city as crime ridden and sued over the attempt to take over the police force, but have walked a finer line on the deployment of the Guard, which Trump has the power to do unilaterally in D.C. since the district is not a state.

At a news conference Monday, D.C. Mayor Muriel Bowser deflected a question about reports that the administration was considering arming Guardsmen, but she has stressed that Guardsmen should not be used for law enforcement.

"They have to be used on mission-specific items that benefit the nation," she said at a Wednesday news conference. "I don't think you have armed militia in the nation's capital."

Related: Walks on the Mall, Shake Shack Burgers and a Car Crash: Scenes from the Guard's Deployment in DC^[5]

This article first appeared on The War Horse,^[1] an award-winning nonprofit news organization educating the public on military service. Subscribe to their newsletter^[2].

For many Americans, the U.S. Army^[3] is nearly synonymous with its helicopters. Think of popular films such as Black Hawk^[4] Down, We Were Soldiers, and Apocalypse Now.

But in recent months, the service announced a plan to pare down its helicopter fleet, catching many of its aviators off guard.

The cuts are part of a larger reorganization as the Army prepares for the changing landscape of warfare with one of the services' smallest budget increases^[5]. The War Horse spoke with Jeremiah Gertler, senior analyst at the Teal Group defense and aerospace consulting company, to better understand why the Army is nixing so many of its iconic aircraft, what might replace them, and what might happen to the soldiers who work with them.

First, some background and a look back at how we got here.

Heavy helicopter losses among Russian forces in Ukraine led top U.S. Army officials to question the survivability^[6] of manned rotorcraft in future conflicts. Last year, the service cancelled the development of a new attack and reconnaissance helicopter, with Chief of Staff Gen. Randy George pointing out^[7] that sensors and weapons mounted on unmanned aerial systems--think drones--are "more ubiquitous, further reaching, and more inexpensive than ever before."

That effort accelerated in May, when the Army said^[8] it will reduce one air cavalry squadron per active-duty combat aviation brigade.

In the months since, the Army said it would also divest^[9] many of its older UH-60^[10]s and AH-64^[11]s and inactivate^[12] the helicopter units in both of its Reserve expeditionary combat aviation brigades. Inactivate is not the same as deactivate, which means a permanent closure, but the Army has not announced plans for what it intends to do next with the units.

Q.: What Does the US Army Use Helicopters for?

The Army generally uses helicopters for attack and logistics missions, Gertler explained. The AH-64 Apache^[13] carries an arsenal^[14] of rockets, missiles, and a 30 mm chain gun in the attack and reconnaissance role. Meanwhile, the smaller UH-72^[15] Lakota^[16], medium-sized H-60 Black Hawk, and large H-47 Chinook^[17] helicopters carry troops, medical supplies, ammunition, humanitarian aid, and other cargo in and out of battlefields and crisis zones.

Q.: Why Does the Army Want to Get Rid of So Many Helicopters?

Gertler said it is the result of two influences: budgetary pressure to reduce the number of units in the Army and analysis of the war in Ukraine^[18], where large numbers of surface-to-air missiles threaten helicopters, and modular, affordable drones can perform low-altitude attack and reconnaissance missions.

"That is part of what's informing it, just the fact that pretty much anything that flies on that battlefield dies," Gertler said about the shrinking helicopter fleet.

He said the divestments are unrelated to the safety issues plaguing Army aviation^[19] in recent years, even before 67 people died on Jan. 29 when an Army Black Hawk collided with an American Airlines flight outside Washington, D.C.

Q.: Can Drones Do What Helicopters Do?

"Well, right now the Army is looking to experiment and find out what really works," Gertler said.

Both armies in Ukraine use drones extensively^[20] in reconnaissance and surveillance roles, as spotters to guide artillery strikes, and as jammers to disrupt enemy communication and navigation systems. They have also proven useful in limited attack roles by dropping small munitions such as hand grenades^[21] or by loitering above a target before striking like a missile.

Maj. Gen. Clair Gill, a top Army aviation official, wrote in Army Aviation Magazine^[22] that drones "should do the 'dirty, dull, dangerous' work" that do not require a human's rapid decision-making or ethical judgment.

But manned rotorcraft writ large are not going away any time soon, particularly for the transport role. Army officials expect to operate the H-60 until 2070^[23], and the service is steaming ahead on its replacement, the MV-75^[24], a tiltrotor that can fly like a fixed-wing airplane and land like a helicopter, similar to the Osprey flown by the Navy^[25], Marine Corps^[26] and Air Force^[27]. NATO experts also point out that changing Russian tactics have made its attack helicopter fleet more effective^[28] now than it was at the start of the war.

Q.: Why the Heavy Cuts for the Reserve in Particular?

"The helicopters in the National Guard^[29] have significant state roles for things like search and rescue and disaster relief, so it's hard to draw those down," Gertler said. "And because, frankly, Congress has traditionally defended the Guard more strongly than the Reserve."

Q.: What Happens to the Soldiers in those Units?

The ideal solution is to retrain those troops in a new role, Gertler said, but not all unit members may want to switch. Some may try to find a helicopter job in a new unit, or leave the Army.

Command Sgt. Maj. Nathan Smith, the top enlisted leader in one of the units being inactivated, the 5-159th General Support Aviation Battalion, voiced the same concern.

"People that come here live and breathe flying Army helicopters," he told^[30] The Virginian-Pilot. "Depending on where they are in their careers, the sentiment is, well, now what am I going to do?"

More than a dozen Army Reserve aviators told^[31] Military.com they were frustrated with the rollout of the decision, which they said was chaotic and poorly communicated.

Q.: What's the Risk of Divesting These Aircraft?

Army leaders frame the transition as a way to stay relevant^[32] in modern war, though it's not clear at this point what will replace the helicopters.

"Anytime that you reduce the budget for the military without reducing the number of threats, you're taking a risk," Gertler said. "The Army is also at a strategic risk now, because they are figuring out, as they come out of a very busy period over the last 20 years, what is their role going forward in a more globally oriented and Pacific-oriented fight?"

Hopefully, at the other end of that, Gertler said, the Army units losing their helicopters will find a new way to contribute.

"Whereas if they continued with the helicopter mission," he said, "the unit might be in danger of going away entirely."

This War Horse explainer was reported by David Roza, edited by Mike Frankel, fact-checked by Jess Rohan and copy-edited by Mitchell Hansen-Dewar.

David Roza is a journalist who has covered the U.S. military since 2019. His work has appeared in Air & Space Forces Magazine and Task & Purpose. He can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

Editor's Note: This article^[33] first appeared on The War Horse,^[34] an award-winning nonprofit news organization educating the public on military service. Subscribe to their newsletter.^[35]

However, less attention has been paid to its role in day-to-day situations.

In a study published in Molecular Metabolism, University of Michigan researchers have shown that a specific population of neurons in the hypothalamus help the brain maintain blood glucose levels under routine circumstances.

Over the past five decades, researchers have shown that dysfunction of the nervous system can lead to fluctuations in blood glucose levels, especially in patients with diabetes.

Some of these neurons are in the ventromedial nucleus of the hypothalamus, a region of the brain that controls hunger, fear, temperature regulation and sexual activity.

"Most studies have shown that this region is involved in raising blood sugar during emergencies," said Alison Affinati, M.D., Ph.D., assistant professor of internal medicine and member of Caswell Diabetes Institute.

"We wanted to understand whether it is also important in controlling blood sugar during day-to-day activities because that's when diabetes develops."

The group focused on VMH^Cckbr neurons, which contain a protein called the cholecystokinin b receptor.

They used mouse models in which these neurons were inactivated.

By monitoring the blood glucose levels, the researchers found that VMH^Cckbr neurons play an important role in maintaining glucose during normal activities, including the early part of the fasting period between the last meal of the day and waking up in the morning.

"In the first four hours after you go to bed, these neurons ensure that you have enough glucose so that you don't become hypoglycemic overnight," Affinati said.

To do so, the neurons direct the body to burn fat through a process called lipolysis.

"In the first four hours after you go to bed, these neurons ensure that you have enough glucose so that you don't become hypoglycemic overnight."

-Alison Affinati, M.D., Ph.D.

The fats are broken down to produce glycerol, which is used to make sugar.

When the group activated the VMH^Cckbr neurons in mice, the animals had increased glycerol levels in their bodies.

These findings could explain what happens in patients with prediabetes, since they show an increase in lipolysis during the night.

The researchers believe that in these patients, the VMH^Cckbr neurons could be overactive, contributing to higher blood sugar.

These nerve cells, however, only controlled lipolysis, which raises the possibility that other cells might be controlling glucose levels through different mechanisms.

"Our studies show that the control of glucose is not an on-or-off switch as previously thought," Affinati said.

"Different populations of neurons work together, and everything gets turned on in an emergency. However, under routine conditions, it allows for subtle changes."

The team is working to understand how all the neurons in the ventromedial nucleus co-ordinate their functions to regulate sugar levels during different conditions, including fasting, feeding and stress.

They are also interested in understanding how the brain and nervous system together affect the body's control of sugar, especially in the liver and pancreas.

The work was carried out by a team of U-M researchers at the Caswell Diabetes Institute who focus on the neuronal control of metabolism -- the roles played by the brain and nervous system in metabolic control and disease.

Additional authors: Jiaao Su, Abdullah Hashsham, Nandan Kodur, Carla Burton, Amanda Mancuso, Anjan Singer, Jennifer Wloszek, Abigail J. Tomlinson, Warren T. Yacawych, Jonathan N. Flak, Kenneth T. Lewis, Lily R. Oles, Hiroyuki Mori, Nadejda Bozadjieva-Kramer, Adina F. Turcu, Ormond A. MacDougald and Martin G. Myers.

Funding/disclosures: Research support was provided by the Michigan Diabetes Research Center (NIH grant P30 DK020572), the Mouse Metabolic Phenotyping Center -- Live (U2CDK135066) Physiology Phenotyping Core, the Michigan Nutrition and Obesity Center Adipose Tissue Core (P30 DK089503); Department of Veterans Affairs (IK2BX005715); the Warren Alpert Foundation; Endocrine Fellows Foundation; Marilyn H. Vincent Foundation and Novo Nordisk. This work was also supported in part by NIH grant K08 DK1297226.

The research team found that even moderately irregular sleep doubles the risk of having another clinical event within six months, according to a study published on August 21 in the journal JACC Advances. A clinical event could be another visit to the emergency room, hospitalization or even death.

"Going to bed and waking up at consistent times is important for overall health," said lead author Brooke Shafer, Ph.D., a research assistant professor in the Sleep, Chronobiology and Health Laboratory in the OHSU School of Nursing. "Our study suggests that consistency in sleep timing may be especially important for adults with heart failure."

Researchers enrolled 32 patients who had been hospitalized for acutely decompensated heart failure at OHSU Hospital and Hillsboro Medical Center from September 2022 through October 2023. For one week following hospital discharge, participants used sleep diaries to record the time they fell asleep at night, woke up in the morning and the timing of naps they took during the day.

The participants were then categorized as regular sleepers or moderately irregular sleepers, based on their sleep patterns.

The study found:

• Following discharge from the hospital, 21 participants experienced a clinical event over the course of six months.
• Of that group, 13 were classified as moderately irregular sleepers compared with eight classified as having a regular sleep schedule.
• Statistically, the irregular sleepers had more than double the risk of an event across the six-month time span.

The increased risk of a clinical event for moderately irregular sleepers remained even when accounting for possible contributing factors like sleep disorders and other underlying medical conditions. The research team says the study is among the first to examine the impact of sleep regularity in the context of heart failure, and the findings add to a growing body of evidence suggesting the importance of maintaining a regular sleep schedule.

"Improving sleep regularity may be a low-cost therapeutic approach to mitigate adverse events in adults with heart failure," the authors conclude.

Shafer said the results strengthen the connection between sleep regularity and cardiovascular health.

"When we're asleep and in a resting state, our blood pressure and heart rate decrease compared with daytime levels," she said. "But variability in sleep timing may disrupt mechanisms involved in the regulation of the cardiovascular system. Irregular sleep may contribute to adverse outcomes, especially for people already affected by heart failure."

The next step would be to scale up the research to a larger cohort of participants and see whether improving sleep regularity lowers the risk of another clinical event, she said.

In addition to Shafer, co-authors include Shirin Hiatt, M.P.H., RN, Sophia Kogan, B.S.N., RN, Nathan Dieckmann, Ph.D., Christopher Chien, M.D., Quin Denfeld, Ph.D., RN, and Andrew McHill, Ph.D., all of OHSU; and Christopher Lee, Ph.D., RN, of Boston College.

The study was supported by the National Heart, Lung, and Blood Institute; the Eunice Kennedy Shriver National Institute of Child Health & Human Development; and the National Institute of Nursing Research, all of the National Institutes of Health, awards T32HL083808, K12AR084221 and R01NR019054, respectively; and the OHSU School of Nursing. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

The research, led by McGill University scientist Masha Prager-Khoutorsky in collaboration with an interdisciplinary team at McGill and the Research Institute of the McGill University Health Centre, suggests the brain may be a missing link in certain forms of high blood pressure - or hypertension - traditionally attributed to the kidneys.

"This is new evidence that high blood pressure can originate in the brain, opening the door for developing treatments that act on the brain," said Prager-Khoutorsky, associate professor in McGill's Department of Physiology.

Hypertension affects two-thirds of people over 60 and contributes to 10 million deaths worldwide each year. Often symptomless, the condition increases the risk of heart disease, stroke and other serious health problems.

About one-third of patients don't respond to standard medications, which primarily target the blood vessels and kidneys based on the long-standing view that hypertension begins there. The study, published in the journal Neuron, suggests the brain may also be a key driver of the condition, particularly in treatment-resistant cases.

How salt disrupts the brain

To mimic human eating patterns, rats were given water containing two per cent salt, comparable to a daily diet high in fast food and items like bacon, instant noodles and processed cheese.

The high-salt diet activated immune cells in a specific brain region, causing inflammation and a surge in the hormone vasopressin, which raises blood pressure. Researchers tracked these changes using cutting-edge brain imaging and lab techniques that only recently became available.

"The brain's role in hypertension has largely been overlooked, in part because it's harder to study," Prager-Khoutorsky said. "But with new techniques, we're able to see these changes in action."

The researchers used rats instead of the more commonly studied mice because rats regulate salt and water more like humans. That makes the findings more likely to apply to people, noted Prager-Khoutorsky.

Next, the scientists plan to study whether similar processes are involved in other forms of hypertension.

"Microglia regulate neuronal activity via structural remodeling of astrocytes" by Ning Gu et al., was published in Neuron and supported by the Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada and the Azrieli Foundation.

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