‘Feast and fast’ migration sees whales lose 36% body fat

Griffith University

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The researchers used drone photography and converted the pixel-based images into real-life measurements. Credit: Griffith University

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Credit: Griffith University

New research into the energy use of humpback whales during their annual migrations has found they lose 11,000kg of blubber - which is equivalent to the energy obtained after feeding on 57,000 kg of Antarctic krill - highlighting the importance of managing their krill-rich feeding grounds.

PhD Candidate Alexandre Bernier-Graveline, from Griffith University's Southern Ocean Persistent Organic Pollutants Program, led the study, using drones to monitor the body condition of 103 adult humpback whales in the southern hemisphere.

Mr Bernier-Graveline and the research team used data from the drone monitoring to determine the whales’ body conditions on their breeding ground in Colombia and on their feeding ground on the Western Antarctic Peninsula, a highly productive krill region of Antarctica.

Each adult whale lost about 36 per cent of its body condition during migration which is equivalent to:

• 12 cubic metres or 11,000kg of blubber (equivalent to the weight of a standard single-decker city bus or two adult African elephants)

• 5,000kg of fat

• 196 million kilojoules of energy (equivalent to the energy consumed by an average adult over 62 years)

• 57,000kg of krill

“Southern hemisphere humpback whales depend on Antarctic krill for their annual energy requirements, fueling their long migrations between feeding and breeding grounds,” Mr Bernier-Graveline said.

“We found the whales were at their fattest in early autumn – March-May – and slimmest by late spring –  August-December – showing a dramatic seasonal change in body condition.

“Our study quantifies the whales’ extreme ‘feast and fast’ lifestyle, and the critical role of Antarctic krill in their survival and migratory life-history strategy.”

Mr Bernier-Graveline said with the Antarctic sea-ice ecosystem rapidly changing, understanding migrating whales' energy demands helped scientists assess how environmental changes – such as krill availability or climate shifts – could impact whale populations.

By linking migration and reproductive energy cost to krill biomass, the findings provided key ecological contexts for understanding how environmental changes such as krill population fluctuations could impact whale populations in the future.

The work was performed under an International Whaling Commission Southern Ocean Research Partnership grant, led by Professor Susan Bengtson Nash, together with researchers from Aarhus University, Denmark; The University of California Santa Cruz, and The University of Los Andes, Colombia.

The study ‘Drone-based photogrammetry provides estimates of the energetic cost of migration for humpback whales between Antarctica and Colombia’ has been published in Marine Mammal Science.

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Journal

Marine Mammal Science

DOI

10.1111/mms.70048 

 

Pick up the pace of your daily walk to boost longevity, experts say

An analysis of an underrepresented cohort of low-income and Black individuals in the American Journal of Preventive Medicine confirms benefits of walking

Elsevier

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Ann Arbor, July 29, 2025 - Regular walking is widely recognized for its significant benefits to overall health and well-being. Previous research has primarily focused on middle-to-high-income White populations. Now, a novel analysis using data from the Southern Community Cohort Study, involving 79,856 predominantly low-income and Black individuals across 12 southeastern US states, confirms the benefits of regular walking, especially at a faster pace, within a crucial, underrepresented group. The new study appearing in the American Journal of Preventive Medicine, published by Elsevier, underscores the importance of promoting walking, particularly at a brisk pace, as an effective form of physical activity for improving health.

Lead investigator Wei Zheng, MD, PhD, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, School of Medicine, Vanderbilt University, and Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, says, “While the health benefits of daily walking are well-established, limited research has investigated effects of factors such as walking pace on mortality, particularly in low-income and Black/African-American populations. Our research has shown that fast walking as little as 15 minutes a day was associated with a nearly 20% reduction in total mortality, while a smaller reduction in mortality was found in association with more than three hours of daily slow walking. This benefit remained strong even after accounting for other lifestyle factors and was consistent across various sensitivity analyses.”

Participants reported the average amount of time per day (minutes) they typically spend “walking slowly (such as moving around, walking at work, walking the dog, or engaging in light exercise)” and “walking fast (such as climbing stairs, brisk walking, or exercising).” Information regarding vital status and cause of death was obtained by linking the cohort to the National Death Index.

The protective effect of fast walking extended to all causes of death but was most pronounced for cardiovascular diseases. Importantly, the benefits of fast walking were independent of overall leisure-time physical activity levels (LTPA). Even for those who are already engaged in slow walking or some LTPA, adding more fast walking further reduced mortality.

According to the study the benefits of fast walking related to cardiovascular health are:

• Boosts heart efficiency: As an aerobic exercise, fast walking improves cardiac output, increases oxygen delivery, and enhances the efficiency of the heart's pumping action, leading to better overall cardiovascular health.
• Manages cardiovascular risk factors: Regular fast walking helps control body weight and composition, reducing obesity and related risks like hypertension and dyslipidemia.
• Highly accessible: Fast walking is a convenient, low-impact activity suitable for individuals of all ages and fitness levels.

Low-income populations often face economic constraints and are more likely to reside in impoverished, highly polluted communities with limited access to safe walking spaces. Additionally, these populations tend to have a higher prevalence of lifestyle behaviors that may increase disease risk and mortality, such as lower quality diet, cigarette smoking, and heavy alcohol consumption. At the same time, there are other challenges for individuals with low income such as lack of access to health insurance or healthcare that may also increase mortality. These factors collectively contribute to an increased mortality among low-income individuals and may potentially elucidate the racial disparities observed in longevity. By demonstrating the benefits of fast walking in this study, this research provides direct evidence to inform targeted interventions and policies to improve health equity.

Lead author of the article Lili Liu, MPH, Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, School of Medicine, and Vanderbilt University, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, concludes, “Public health campaigns and community-based programs can emphasize the importance and availability of fast walking to improve health outcomes, providing resources and support to facilitate increased fast walking within all communities. Furthermore, the findings of the reduced mortality associated with fast walking pace were supported by previous studies conducted in middle- and upper-middle-income populations. Individuals should strive to incorporate more intense physical activity into their routines, such as brisk walking or other forms of aerobic exercise.”

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Journal

American Journal of Preventive Medicine

DOI

10.1016/j.amepre.2025.107738 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Daily Walking and Mortality in Racially and Socioeconomically Diverse U.S. Adults

Article Publication Date

29-Jul-2025

 

How much time did our ancestors spend up trees? Studying these chimpanzees might help us find out

A study on savannah-living chimpanzees suggests the need to move safely on thin tree branches could explain why early hominins that could walk upright kept their tree-climbing adaptations

Frontiers

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A young male chimp feeds on woodland seeds. Image by Rhianna C. Drummond-Clarke/Greater Mahale Ecosystem Research and Conservation (GMERC)

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Credit: Rhianna C. Drummond-Clarke/Greater Mahale Ecosystem Research and Conservation (GMERC)

It’s hard to tell when — and why — our ancestors got down from trees and started walking on two legs. Many early hominins capable of bipedal walking were also well-adapted for climbing, and we lack fossil evidence from a key period when climate change turned forests into open, dry woodland called savannah-mosaic, which might have pushed hominins onto the ground. Now a study on modern chimpanzees could help fill in the gaps. Scientists observing chimpanzees in the Issa Valley, Tanzania have shown that despite living in a savannah-mosaic, they frequently climb trees for valuable food — potentially explaining why early hominins kept their arboreal adaptations.  

“For decades it was assumed that bipedalism arose because we came down from the trees and needed to walk across an open savannah,” said Dr Rhianna Drummond-Clarke of the Max Planck Institute for Evolutionary Anthropology, lead author of the article in Frontiers in Ecology and Evolution. “Here we show that safely and effectively navigating the canopy can remain very important for a large, semi-arboreal ape, even in open habitat. Adaptations to arboreal, rather than terrestrial, living may have been key in shaping the early evolution of the human lineage.” 

Habitats and hunger 

Issa Valley is divided between a small amount of thick forest surrounding riverbanks and open woodland. The chimpanzees forage more in the woodland during the dry season, when it offers more food. Their habitat and diet are comparable to those of some early hominins, which means their behavior might offer insights into those extinct hominins’ lives.  

“Our previous research found that, compared to chimpanzees living in forests, Issa Valley chimpanzees spent just as much time moving in the trees,” said Drummond-Clarke. “We wanted to test if something about how they foraged could explain their unexpectedly high arboreality. Savannah-mosaics are characterized by more sparsely distributed trees, so we hypothesized that adapting behavior to forage efficiently in a tree would be especially beneficial when the next tree is further away.” 

Researchers monitored the adults of the Issa community during the dry season, watching how they foraged in trees and what they ate there. The size, height, and shape of the trees were recorded, as well as the number and size of branches.  

Issa chimpanzees mostly ate fruit, followed by leaves and flowers — foods found at the ends of branches, so the chimpanzees needed to be capable climbers to reach them safely. They spent longer foraging in trees that were larger and offered more food. The longest foraging sessions, and the most specialized behaviors to navigate thinner terminal branches, were seen in trees with large open crowns offering lots of food: perhaps abundant food justified the extra time and effort. A similar trade-off between the nutritional benefits of specific foods and the effort of acquiring them could also explain why chimpanzees spent longer in trees while eating nutritionally-rich, hard-to-access seeds. 

Fast food 

Because they are relatively large, chimpanzees move within trees not by climbing on thin branches but by hanging under them, or standing upright and holding on to nearby branches with their hands. Although these ‘safe’ behaviors are traditionally associated with foraging in dense forest, these findings show they’re also important for chimpanzees foraging in a savannah-mosaic. 

“We suggest our bipedal gait continued to evolve in the trees even after the shift to an open habitat,” said Drummond-Clarke. “Observational studies of great apes demonstrate they can walk on the ground for a few steps, but most often use bipedalism in the trees. It’s logical that our early hominin relatives also engaged in this kind of bipedalism, where they can hold onto branches for extra balance. If Issa Valley chimpanzees can be considered suitable models, suspensory and bipedal behaviors were likely vital for a large-bodied, fruit-eating, semi-terrestrial hominin to survive in an open habitat.”  

However, the researchers say that we need more fossil evidence and more studies on different aspects of chimpanzee foraging to test this idea. 

“This study only looked at foraging behavior during the dry season,” cautioned Drummond-Clarke. “It would be interesting to investigate if these patterns remain during the wet season. Analyses of the nutritional value of foods and overall food availability are also needed to test our hypothesis that a strategy of foraging for longer in large trees on certain foods is energy-efficient in an open habitat.  

“Importantly, this is also only one community of chimpanzees. Future studies of other chimpanzees living in such dry, open habitats will be vital to see if these patterns are truly a savannah-mosaic signal or unique to Issa.” 

A group of Issa Valley chimpanzees navigate an open woodland crown to forage on new leaves. Image by Rhianna C. Drummond-Clarke/Greater Mahale Ecosystem Research and Conservation (GMERC)

A mother chimpanzee looks out from the central tree to her breakfast (seeds!) at the end of thin branches. Image by Rhianna C. Drummond-Clarke/Greater Mahale Ecosystem Research and Conservation (GMERC)

Credit

Rhianna C. Drummond-Clarke/Greater Mahale Ecosystem Research and Conservation (GMERC)

Journal

Frontiers in Ecology and Evolution

DOI

10.3389/fevo.2025.1561078 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Foraging strategy and tree structure as drivers of arboreality and suspensory behaviour in savannah chimpanzees

Article Publication Date

29-Jul-2025

COI Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

 SOMETHING FROM NOTHING

When light collides with light

Vienna University of Technology

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Light is scattered by light – via virtual particles

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Credit: TU Wien

Usually, light waves can pass through each other without any resistance. According to the laws of electrodynamics, two light beams can exist in the same place without influencing each other; they simply overlap. Light saber battles, as seen in science fiction films, would therefore be rather boring in reality.

Nevertheless, quantum physics predicts the effect of “light-on-light scattering”. Ordinary lasers are not powerful enough to detect it, but it has been observed at the CERN particle accelerator. Virtual particles can literally emerge from nothing for a short time, interact with the photons and change their direction. The effect is extremely small, but it must be understood precisely in order to verify particle physics theories through current high-precision experiments on muons. A team at TU Wien (Vienna) has now been able to show that a previously underestimated aspect plays an important role in this: the contribution of so-called tensor mesons. The new results have been published in the journal Physical Review Letters.

Virtual particles from nothing

When photons interact with photons, virtual particles can be created. They cannot be measured directly, as they disappear immediately. In a sense, they are constantly there and not there at the same time – quantum physics allows such superpositions of states that would be mutually exclusive according to our classical everyday understanding.

“Even though these virtual particles cannot be observed directly, they have a measurable effect on other particles,” says Jonas Mager from the Institute of Theoretical Physics at TU Wien, lead author of the study. “If you want to calculate precisely how real particles behave, you have to take all conceivable virtual particles into account correctly. That's what makes this task so difficult – but also so interesting.”

When light scatters off light, a photon may transform, for example, into an electron-positron pair. Other photons can then interact with these two particles before the electron and positron annihilate each other and become a new photon. Things become more complicated when heavier particles are created that are also subject to strong nuclear forces – for example, mesons, which consist of a quark and an antiquark.

“There are different types of these mesons,” says Jonas Mager. “We have now been able to show that one of them, the tensor mesons, has been significantly underestimated. Through the effect of light-light scattering, they influence the magnetic properties of muons, which can be used to test the Standard Model of particle physics with extreme accuracy.” Tensor mesons did appear in earlier calculations, but with very rough simplifications. In the new evaluation, not only does their contribution turn out to be much stronger than previously assumed, but it also has a different sign than previously thought, thus influencing the results in the opposite direction.

Unusual theoretical methods

This result also resolves a discrepancy that arose last year between the latest analytical calculations and alternative computer simulations. “The problem is that conventional analytical calculations can describe the strong interactions of quarks only well in limiting cases,” says Anton Rebhan (TU Wien).

The TU Wien team, on the other hand, used an unconventional method – holographic quantum chromodynamics. This involves mapping processes in four dimensions (i.e. three spatial dimensions and one time dimension) onto a five-dimensional space with gravity. Some problems can then be solved more easily in this other space, and the results are then transformed back again. “The tensor mesons can be mapped onto five-dimensional gravitons, for which Einstein's theory of gravity makes clear predictions,” explains Anton Rebhan. "We now have computer simulations and analytical results that fit well together but deviate from certain previous assumptions. We hope that this will also provide new impetus to accelerate already planned specific experiments on tensor mesons."

The standard model put to the test

These analyses are important for one of the biggest questions in physics: How reliable is the Standard Model of particle physics? This is the generally accepted quantum physical theory that describes all known types of particles and all forces of nature – except gravity.

The accuracy of the Standard Model can be investigated particularly well in a few special test cases, for example by measuring the magnetic moment of muons. For many years, scientists have been puzzling over whether certain discrepancies between theory and experiment point to “new physics” beyond the Standard Model, or whether they are simply inaccuracies or errors. The discrepancy in the muon magnetic moment has recently become much smaller – but in order to really search for new physics, the remaining theoretical uncertainties must also be understood as precisely as possible. This is exactly what the new work contributes to.

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Journal

Physical Review Letters

DOI

10.1103/dxwr-gpsl 

Article Title

Longitudinal short-distance constraints on hadronic light-by-light scattering and tensor-meson contributions to the muon 𝑔−2

Article Publication Date

21-Jul-2025

TECHNOMAGE    BABALON 5

 

VR nature scenes reduce sensitivity to pain – especially for those who feel present during the experience

Immersing in virtual reality (VR) nature scenes helped relieve symptoms that are often seen in people living with long-term pain, with those who felt more present experiencing the strongest effects.

University of Exeter

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Immersing in virtual reality (VR) nature scenes helped relieve symptoms that are often seen in people living with long-term pain, with those who felt more present experiencing the strongest effects.

A new study led by the University of Exeter, published in the journal Pain, tested the impact of immersive 360-degree nature films delivered using VR compared with 2D video images in reducing experience of pain, finding VR almost twice as effective.  

Long-term (chronic) pain typically lasts more than three months and is particularly difficult to treat. The researchers simulated this type of pain in healthy participants, finding that nature VR had an effect similar to that of painkillers, which endured for at least five minutes after the VR experience had ended.

Dr Sam Hughes, Senior Lecturer in Pain Neuroscience at the University of Exeter, led the study. He said: “We’ve seen a growing body of evidence show that exposure to nature can help reduce short term, everyday pain, but there has been less research into how this might work for people living with chronic or longer-term pain.  Also, not everyone is able to get out for walks in nature, particularly those living with long term health conditions like chronic pain. Our study is the first to look at the effect of prolonged exposure to a virtual reality nature scene on symptoms seen during long term pain sensitivity. Our results suggest that immersive nature experiences can reduce the development of this pain sensitivity through an enhanced sense of presence and through harnessing the brains in-built pain suppression systems’’

The study, which was funded by the Academy of Medical Sciences, involved 29 healthy participants who were shown two types of nature scene after having pain delivered on the forearm using electric shocks. On the first visit, they measured the changes in pain that occur over a 50-minute period following the electric shocks and showed how the healthy participants developed sensitivity to sharp pricking stimuli in the absence of any nature scenes. The results showed that the participants developed a type of sensitivity that closely resembles that seen in people living with nerve pain - which occurs due to changes in how pain signals are processed in the brain and spinal cord.

On the second visit, they immersed the same participants in a 45-minute virtual reality 360-degree experience of the waterfalls of Oregon to see how this could change how the development of pain sensitivity.  The scene was specially chosen to maximise therapeutic effects.

In the second visit, they explored the same scene, but on a 2D screen.

They completed questionnaires on their experience of pain after watching the scenes in each case, and also on how present they felt in each experience, and to what extent they felt the nature scenes to be restorative[LV1] .

On a separate visit, participants underwent MRI brain scans at the University of Exeter’s Mireille Gillings Neuroimaging Centre. Researchers administered a cold gel to illicit a type of ongoing pain and then scanned participants to study how their brains respond.

The researchers found that the immersive VR experience significantly reduced the development and spread of feelings of pain sensitivity to pricking stimuli, and these pain-reducing effects were still there even at the end of the 45-minute experience.

The more present the person felt during the VR experience, the stronger this pain-relieving effect. The fMRI brain scans also revealed that people with stronger connectivity in brain regions involved in modulating pain responses experienced less pain. The results suggest that nature scenes delivered using VR can help to change how pain signals are transmitted in the brain and spinal cord during long-term pain conditions.

Dr Sonia Medina, of the University of Exeter Medical School and one of the authors on the study, said: “We think VR has a particularly strong effect on reducing experience of pain because it’s so immersive. It really created that feeling of being present in nature – and we found the pain -reducing effect was greatest in people for whom that perception was strongest. We hope our study leads to more research to investigate further how exposure to nature effects our pain responses, so we could one day see nature scenes incorporated into ways of reducing pain for people in settings like care homes or hospitals.”

The paper is titled ‘Immersion in nature through virtual reality attenuates the development and spread of mechanical secondary hyperalgesia: a role for insulo-thalamic effective connectivity’ and is published in the journal Pain.

ENDS  

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Journal

Pain

Method of Research

Observational study

Subject of Research

People

Article Title

Immersion in nature through virtual reality attenuates the development and spread of mechanical secondary hyperalgesia: a role for insulo-thalamic effective connectivity

Article Publication Date

28-Jul-2025

 

Coolness hits different; now scientists know why

University of Michigan

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Researchers at the University of Michigan have illuminated a complete sensory pathway showing how the skin communicates the temperature of its surroundings to the brain.

This discovery, believed to be the first of its kind, reveals that cool temperatures get their own pathway, indicating that evolution has created different circuits for hot and cold temperatures. This creates an elegant solution for ensuring precise thermal perception and appropriate behavioral responses to environmental changes, said Bo Duan, senior author of the new study.

"The skin is the body's largest organ. It helps us detect our environment and separate, distinguish different stimuli," said Duan, a U-M associate professor of molecular, cellular, and developmental biology. "There are still many interesting questions about how it does this, but we now have one pathway for how it senses cool temperatures. This is the first neural circuit for temperature sensation in which the full pathway from the skin to the brain has been clearly identified."

This work deepens our understanding of fundamental biology and brings us closer to an explanation for how we evolved to inhabit safe temperatures and avoid dangerous extremes, Duan said. But it also has medical implications that can be explored to help improve the quality of life for people in the future.

For example, more than 70% of people who have undergone chemotherapy experience pain caused by cool temperatures, Duan said. The new study found that the neural circuit responsible for sensing innocuous cool does not mediate this type of cold pain. But, in understanding how the cool-sensing circuitry works when it's functioning properly under normal conditions, researchers now have a better chance of discovering what goes wrong in disease or injury. It could also help develop targeted therapies that restore healthy sensation without impairing normal temperature perception.

This research was funded by the National Institutes of Health and performed in collaboration with Shawn Xu and his research team in the U-M Life Sciences Institute.

A cool amplifier discovery

In their study, published in the journal Nature Communications, Duan and his team used sophisticated imaging techniques and electrophysiology to observe how mice transmitted the sensation of cool temperatures from their skin to the brain. 

It's an approach the team has applied to other sensations in the past. Headed by postdoctoral research fellow Hankyu Lee and doctoral students Chia Chun Hor and Lorraine Horwitz, the team turned its focus to temperature in this work.

"These tools have allowed us to identify the neural pathways for chemical itch and mechanical itch previously," Duan said. "Working together, the team identified this very interesting, very dedicated pathway for cool sensation."

The cool signal starts at the skin, which is home to molecule sensors that can detect a specific range of temperatures between about 15 and 25 degrees Celsius—equivalent to 59 and 77 degrees Fahrenheit. When those sensors engage, they excite primary sensory neurons, which send the cool signal to the spinal cord. Here, the team found that the signal is amplified by specialized interneurons, which then activate projection neurons that connect to the brain.

Researchers had previously known about the skin's molecular thermometers—they, in part, earned researchers in California the 2021 Nobel Prize in Physiology or Medicine—but the spinal cord's amplifier was an unknown key ingredient. With the amplifier disabled, the cool signal becomes lost in the noise, the team found.

Although the study was performed in mice, each component of the circuit has been shown to be in humans through genetic sequencing, Duan said. So it's likely that we have the same pathway to thank for the refreshing sensation of stepping into an air-conditioned room on a hot summer day.

Moving forward, the team is looking to identify the pathway or pathways involved in acute cold pain. 

"I think the painful sensations are going to be more complicated," Duan said. "When we're in riskier situations, there could be multiple pathways involved." 

His team is also interested in how the brain processes these various skin signals and how we've evolved not only to differentiate between them, but also connect emotions with them to help protect ourselves. In fact, it's the curiosity around those sorts of questions that originally motivated Duan's work, which he is perpetually reminded of working in Michigan.

"In summer, I love walking along Lake Michigan and having a gentle breeze hit my face. I feel very cool, very comfortable," Duan said. "But the winter is really terrible for me."

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Journal

Nature Communications

DOI

10.1038/s41467-025-61562-y 

Article Title

A dedicated skin-to-brain circuit for cool sensation in mice

Article Publication Date

28-Jul-2025