The study found that middle age and older adults at elevated risk for cardiometabolic disease benefited from extending their overnight fasting window by roughly two hours. They also avoided food and dimmed lights for three hours before going to sleep. These changes led to measurable improvements in heart and metabolic markers during sleep and throughout the following day.

“Timing our fasting window to work with the body’s natural wake-sleep rhythms can improve the coordination between the heart, metabolism and sleep, all of which work together to protect cardiovascular health,” said first author Dr. Daniela Grimaldi, research associate professor of neurology in the division of sleep medicine at Northwestern University Feinberg School of Medicine.

The findings were published Feb. 12 in Arteriosclerosis, Thrombosis, and Vascular Biology, a journal of the American Heart Association.

“It’s not only how much and what you eat, but also when you eat relative to sleep that is important for the physiological benefits of time-restricted eating,” said corresponding author Dr. Phyllis Zee, director of the Center for Circadian and Sleep Medicine and chief of sleep medicine in the department of neurology at Feinberg.

Why Cardiometabolic Health Matters

Earlier data show that only 6.8% of U.S. adults had optimal cardiometabolic health in 2017 to 2018. Poor cardiometabolic health raises the risk of chronic conditions such as type 2 diabetes, non-alcoholic fatty liver disease, and cardiovascular disease.

Time-restricted eating has grown in popularity because studies suggest it can improve cardiometabolic markers and sometimes match the benefits of traditional calorie restricted diets. However, most research has concentrated on how long people fast rather than how well that fasting window aligns with sleep timing, which is crucial for metabolic regulation.

With nearly 90% adherence in this trial, the researchers believe anchoring time-restricted eating to the sleep period may be a realistic and accessible non-pharmacological approach, especially for middle age and older adults who face higher cardiometabolic risk.

The team plans to refine this protocol and expand testing in larger multi-center trials.

Blood Pressure, Heart Rate, and Blood Sugar Improvements

The 7.5 week study compared individuals who stopped eating at least three hours before bedtime with those who maintained their usual eating habits. Those who adjusted their timing experienced several meaningful changes.

Nighttime blood pressure decreased by 3.5%, and heart rate dropped by 5%. These shifts reflected a healthier daily pattern, with heart rate and blood pressure rising during daytime activity and falling at night during rest. A stronger day night rhythm is associated with better cardiovascular health.

Participants also demonstrated improved daytime blood sugar control. When given glucose, their pancreas responded more effectively, suggesting improved insulin release and steadier blood sugar levels.

The trial included 39 overweight/obese adults (36 to 75 years old). Participants were assigned either to an extended overnight fasting group (13 to 16 hours of fasting) or to a control group that maintained a habitual fasting window (11 to 13 hours). Both groups dimmed lights three hours before bedtime. The intervention group consisted of 80% women.

Funding: NIH/National Heart, Lung and Blood Institute, National Institute on Aging, NIH/National Center for Advancing Translational Sciences (NCATS)

“Sperm metabolism is special since it’s only focused on generating more energy to achieve a single goal: fertilization,” said Melanie Balbach, an assistant professor in the Department of Biochemistry and Molecular Biology and senior author of the study.

Before ejaculation, mammalian sperm remain in a low energy state. Once inside the female reproductive tract, they rapidly transform. They begin swimming more forcefully and adjust the outer membranes that will eventually interact with the egg. These changes demand a sudden and significant rise in energy production.

“Many types of cells undergo this rapid switch from low to high energy states, and sperm are an ideal way to study such metabolic reprogramming,” Balbach said. She joined MSU in 2023 to expand her pioneering work on sperm metabolism.

Tracking the Fuel That Powers Fertilization

Earlier in her career at Weill Cornell Medicine, Balbach helped show that blocking a critical sperm enzyme caused temporary infertility in mice. That discovery highlighted the possibility of nonhormonal male birth control.

Although scientists understood that sperm require large amounts of energy to prepare for fertilization, the exact mechanism behind this surge remained unclear until now.

Working with collaborators at Memorial Sloan Kettering Cancer Center and the Van Andel Institute, Balbach’s team developed a method to follow how sperm process glucose, a sugar they absorb from their surroundings and use as fuel.

By mapping glucose’s chemical path inside the cell, the researchers identified clear differences between inactive sperm and those that had been activated.

“You can think of this approach like painting the roof of a car bright pink and then following that car through traffic using a drone,” Balbach explained.

“In activated sperm, we saw this painted car moving much faster through traffic while preferring a distinct route and could even see what intersections the car tended to get stuck at,” she said.

Using resources such as MSU’s Mass Spectrometry and Metabolomics Core, the team assembled a detailed picture of the multi step, high energy process sperm rely on to achieve fertilization.

Aldolase and the Control of Sperm Metabolism

The study found that an enzyme known as aldolase plays a key role in converting glucose into usable energy. Researchers also learned that sperm draw on internal energy reserves they already carry when their journey begins.

In addition, certain enzymes act like regulators, directing how glucose moves through metabolic pathways and influencing how efficiently energy is produced.

Balbach plans to continue investigating how sperm rely on different fuel sources, including glucose and fructose, to meet their energy demands. This line of research may affect multiple areas of reproductive health.

Implications for Infertility and Nonhormonal Birth Control

Infertility affects about one in six people worldwide. Balbach believes that studying sperm metabolism could lead to better diagnostic tools and improved assisted reproductive technologies.

The findings may also support the development of new contraceptive strategies, particularly nonhormonal approaches.

“Better understanding the metabolism of glucose during sperm activation was an important first step, and now we’re aiming to understand how our findings translate to other species, like human sperm,” Balbach said.

“One option is to explore if one of our ‘traffic-control’ enzymes could be safely targeted as a nonhormonal male or female contraceptive,” she added.

Most efforts to create male contraceptives have focused on stopping sperm production. That strategy has drawbacks. It does not provide immediate, on demand infertility, and many options rely on hormones that can cause significant side effects.

Balbach’s latest work suggests an alternative. By targeting sperm metabolism with an inhibitor based, nonhormonal approach, it may be possible to temporarily disable sperm function when desired while minimizing unwanted effects.

“Right now, about 50% of all pregnancies are unplanned, and this would give men additional options and agency in their fertility,” Balbach said. “Likewise, it creates freedom for those using female birth control, which is hormone-based and highly prone to side effects.

“I’m excited to see what else we can find and how we can apply these discoveries.”

Why This Matters

• Sperm must dramatically boost their energy levels to complete the demanding journey to an egg and achieve fertilization.
• Scientists have now uncovered how sperm tap into glucose in their surroundings to power this surge, revealing the fuel source behind their rapid transformation.
• This discovery deepens our understanding of reproductive biology and could open the door to better infertility treatments and innovative, nonhormonal birth control options.

The research was published in the Proceedings of the National Academy of Sciences and supported by the National Institute of Child Health and Human Development.

In a study published in Nature Machine Intelligence, Sandia National Laboratories computational neuroscientists Brad Theilman and Brad Aimone introduced a new algorithm that allows neuromorphic hardware to solve partial differential equations, or PDEs — the mathematical foundation for modeling phenomena such as fluid dynamics, electromagnetic fields and structural mechanics.

The results demonstrate that neuromorphic systems can handle these equations efficiently. The advance could help open the door to the first neuromorphic supercomputer, offering a new path toward energy efficient computing for national security and other critical applications.

The research was funded by the Department of Energy’s Office of Science through the Advanced Scientific Computing Research and Basic Energy Sciences programs, as well as the National Nuclear Security Administration’s Advanced Simulation and Computing program.

Solving Partial Differential Equations With Brain Like Hardware

Partial differential equations are essential for simulating real world systems. They are used to forecast weather, analyze how materials respond to stress, and model complex physical processes. Traditionally, solving PDEs requires enormous computing power. Neuromorphic computers approach the problem differently by processing information in ways that resemble how the brain operates.

“We’re just starting to have computational systems that can exhibit intelligent-like behavior. But they look nothing like the brain, and the amount of resources that they require is ridiculous, frankly,” Theilman said.

For years, neuromorphic systems were mainly viewed as tools for pattern recognition or for speeding up artificial neural networks. Few expected them to manage mathematically rigorous problems such as PDEs, which are typically handled by large scale supercomputers.

Aimone and Theilman were not surprised by the outcome. They argue that the human brain routinely carries out highly complex calculations, even if people are unaware of it.

“Pick any sort of motor control task — like hitting a tennis ball or swinging a bat at a baseball,” Aimone said. “These are very sophisticated computations. They are exascale-level problems that our brains are capable of doing very cheaply.”

Energy Efficient Computing for National Security

The findings could have major implications for the National Nuclear Security Administration, which is responsible for maintaining the nation’s nuclear deterrent. Supercomputers used across the nuclear weapons complex consume vast amounts of electricity to simulate the physics of nuclear systems and other high stakes scenarios.

Neuromorphic computing may provide a way to significantly cut energy use while still delivering strong computational performance. By solving PDEs in a brain inspired manner, these systems suggest that large simulations could be run using far less power than conventional supercomputers require.

“You can solve real physics problems with brain-like computation,” Aimone said. “That’s something you wouldn’t expect because people’s intuition goes the opposite way. And in fact, that intuition is often wrong.”

The team envisions neuromorphic supercomputers eventually becoming central to Sandia’s mission of protecting national security.

What Neuromorphic Computing Reveals About the Brain

Beyond engineering advances, the research also touches on deeper questions about intelligence and how the brain performs calculations. The algorithm developed by Theilman and Aimone closely mirrors the structure and behavior of cortical networks.

“We based our circuit on a relatively well-known model in the computational neuroscience world,” Theilman said. “We’ve shown the model has a natural but non-obvious link to PDEs, and that link hasn’t been made until now — 12 years after the model was introduced.”

The researchers believe this work could help connect neuroscience with applied mathematics, offering new understanding of how the brain processes information.

“Diseases of the brain could be diseases of computation,” Aimone said. “But we don’t have a solid grasp on how the brain performs computations yet.”

If that idea proves correct, neuromorphic computing might one day contribute to better understanding and treatment of neurological disorders such as Alzheimer’s and Parkinson’s.

Building the Next Generation of Supercomputers

Neuromorphic computing remains an emerging field, but this work represents an important step forward. The Sandia team hopes their results will encourage collaboration among mathematicians, neuroscientists and engineers to expand what this technology can achieve.

“If we’ve already shown that we can import this relatively basic but fundamental applied math algorithm into neuromorphic — is there a corresponding neuromorphic formulation for even more advanced applied math techniques?” Theilman said.

As development continues, the researchers are optimistic. “We have a foot in the door for understanding the scientific questions, but also we have something that solves a real problem,” Theilman said.

“Savoring involves slowing down to become aware of and focus on positive experiences,” said first author Noah Larsen, a graduate student at Illinois. “Savoring can occur when we reminisce on a past experience, focus on the present moment or look ahead to a future experience.”

Previous studies have shown that savoring benefits individuals. Larsen and his colleagues, Illinois human development and family studies professors Allen W. Barton and Brian G. Ogolsky, wanted to see what happens when couples practice savoring together as a shared activity. The participants were drawn from a larger project examining resilience in romantic relationships.

Study of Joint Savoring in Romantic Relationships

The research included 589 adults from across the United States who completed an online survey. The questionnaire measured how often they and their partners intentionally appreciated positive experiences in their relationship. Researchers used a scale called Joint Savoring in Romantic Relationships, adapted from the widely used Savoring Beliefs Inventory, which assesses how individuals savor positive moments.

Participants also answered questions about how satisfied they felt with their spouse or significant other, how much conflict they experienced in communication, and how confident they were that their relationship would last.

The survey assessed stress as well. Participants reported how frequently during the past month they felt in control of their responsibilities or, on the other hand, overwhelmed by what they had to handle. They also rated their overall quality of life, general health, and psychological distress.

Who Took Part in the Study

Of the 589 respondents, more than 85% were married, around 10% were engaged, and 4% were in committed dating relationships. Their partners did not participate in the survey. The average age was about 39. Slightly more than half were women, more than 85% were white, and the typical household income ranged from $85,000 to $95,000.

Overall, participants reported relatively high levels of both individual savoring and joint savoring, along with generally low stress levels.

How Savoring Buffers Relationship Stress

“We found that joint savoring has the most benefits for romantic relationships, as well as secondary benefits for individuals’ health and well-being,” Larsen said. “Specifically, individuals who engaged in more joint savoring with their partners reported less conflict with them, more satisfaction with their relationship and more confidence in their future together.”

The protective effect was especially noticeable among couples facing higher stress. “When couples face greater stress, savoring can serve as a buffer, helping protect their confidence in their relationship and their mental health,” Larsen said.

“Being able to identify factors that provide this type of buffering effect is important for marriage and romantic relationships, as they provide tangible things that couples can do to keep their relationship strong, even in the midst of heightened levels of stress,” Barton said.

The researchers noted that intentionally focusing on shared positive experiences can serve as a practical strategy for maintaining or strengthening a relationship.

A Simple Weekly Habit for Stronger Love

“We all are busy and have so many things going on in our day-to-day lives,” Larsen said. “Finding time — even just once a week — to slow down, be present with your partner and talk about positive experiences in your relationship or focus on something you both enjoy can really benefit you as a couple. That might be reminiscing about a memory from earlier in your relationship, enjoying a dinner together or talking about an upcoming event that you both are excited about. And if you are going through a stressful time, making time for these conversations can be especially important.”