It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Sunday, June 28, 2026
Human activity has driven retreat of Antarctica’s fastest melting glacier
Human-driven climate change significantly intensified the retreat of one the most important glaciers in the Antarctica during the twentieth century.
The Pine Island Glacier, which drains a large part of the West Antarctic Ice Sheet into the Amundsen Sea, is one of the single biggest contributors to global sea level rise.
This landmark research, led by scientists at King’s College London and the British Antarctic Survey and published in The Cryosphere, is the first study to directly attribute the changes of a major Antarctic outlet glacier to the activities of humans.
The authors of the study are also warning that the impact of human activity will continue to shape Antarctic ice loss for centuries.
The research finds that greenhouse gas emissions increased the retreat of Pine Island Glacier by around 18-20% since the 1940s. This has added several kilometres to its landward withdrawal.
Lead author Dr Alex Bradley, Department of Geography, says that the scale of retreat seen over the industrial era is very unlikely to have occurred without human influence.
“Our results show that climate change made the retreat of the Pine Island Glacier substantially worse,” said Dr Bradley, the study’s lead author. “Without sustained warming of the surrounding ocean since the mid twentieth century, the glacier would not have retreated as far as it has.”
While attribution studies have previously linked the retreat of mountain glaciers to human‑driven warming, applying similar techniques to Antarctic glaciers has proven far more challenging.
“This kind of work has become common for heatwaves and floods, and increasingly for mountain glaciers,” said Dr Bradley. “What’s new here is showing, quantitatively, how human influence has altered the course of a major Antarctic glacier.”
Mira Adhikari, an Ice Sheet Modeller at the British Antarctic Survey , said: “Our results add to growing evidence that human-driven climate change is likely affecting even the most remote regions of the planet. Changes in Antarctica have global consequences, particularly for sea level rise, highlighting the far-reaching impacts of a warming world."
Geological records indicate that Pine Island Glacier began retreating rapidly in the 1940s, which was likely due to stronger intrusions of warm ocean water beneath its ice shelf. This study showed that human-driven ocean warming, which is thought to have begun in the 1960s, enhanced the retreat after this.
Using a model that simulates glacier behaviour using observed changes in ice thickness and retreat to constrain its estimates, the researchers compared scenarios with and without human-driven global warming.
By 2015, simulations excluding human influence showed around 4 km less grounding‑line retreat. That difference accounts for just under one‑fifth of the glacier’s observed retreat.
Looking ahead, the models suggest Pine Island Glacier may briefly stabilise later this century as it encounters a ridge in the bedrock beneath it. However, that pause is likely to be temporary if warming continues, with human influence becoming the dominant driver of retreat again in the twenty-second century.
“Ice sheets respond slowly,” Dr Bradley said. “The impacts of today’s emissions will continue to shape Antarctic ice loss for centuries.”
Journal
The Cryosphere
Rediscovery of once-lost super-sized Megalodon vertebrae
International team of scientists sheds new insight into the biology of the prehistoric shark
Dr. Mette Elstrup holding a 10.8-million-year-oldvertebral fossil specimen of the extinct megatooth shark, Otodus megalodon, from the Gram Formation of Denmark featured in the new study, and a reconstructed O. megalodon jaw model in the background
Gram, Denmark — An associated set of gigantic vertebrae belonging to the iconic extinct Megalodon or megatooth shark that had been missing in action since the 1980s was discovered, providing new information about the shark’s lifestyle. Two Museum of Southern Jutland staff, Mette Elstrup and Trine Sørensen, and a researcher at Aarhus University, Henrik Lauridsen, teamed up with a scientist in the United States and another in Australia and took a renewed look at a once-lost vertebral specimen of Otodus megalodon, the fossil shark that lived nearly worldwide about 15 to 3.6 million years ago. The new study appears in the international journal Palaeontologia Electronica.
The rediscovered 10.8-million-year-old vertebral specimen was originally discovered from a large commercially-dug clay pit in Gram, Denmark, in the late 1970s and was scientifically introduced in the early 1980s. The specimen was housed in the Geological Museum of Copenhagen (now part of the Natural History Museum of Denmark), but when the specimen was moved out of the original research laboratory after it was published, it became misplaced, leaving behind only photographic evidence in the scientific literature. The situation changed in the late 2010s when an observant museum staff member fortuitously encountered some mysterious fossil-filled boxes that were tucked in the collection and realized they were the missing Megalodon vertebrae.
Otodus megalodon is commonly portrayed as a gigantic shark in novels and films, such as the 2018 sci-fi thriller “The Meg.” In fact, the most recent estimated maximum size of the fossil species is 24.3 meters in length, which possibly weighed about 94 tons. Although most of the vertebrae have deteriorated, their rediscovery is critical because it is the very specimen that was the basis of the maximum size and weight estimates.
“The rediscovery of the vertebrae was a true delight because they empirically confirm the maximum vertebral diameter of 23 cm reported in the literature,” said the lead author of the new study, Kenshu Shimada, who is a paleobiology professor at DePaul University in Chicago. In fact, “the specimen not only represents the largest shark vertebrae known to date but also the largest fish vertebrae ever recorded to our knowledge,” Shimada added.
Although no complete skeletons of Megalodon exist, the 24.3-meter estimate comes from its vertebral diameter compared with the maximum vertebral diameter (15.5 cm) measured from a reasonably complete string of trunk vertebrae known from Belgium, which is thought to have come from a 16.4-meter-long individual.
Sørensen, a Natural History Conservator at the Museum of Southern Jutland, who prepared the vertebral specimen, stated, “The sharks’ cartilaginous skeletons make their preservation potential generally very low except for their highly mineralized teeth. The Gram Formation exposed in the claypit is special in that we have multiple examples of well-preserved fossilized shark vertebrae in addition to teeth from many shark species, although one known gigantic Megalodon tooth and the specimen in our study remain to be the only Megalodon vertebrae from the site.”
Elstrup, the Head of the Natural History section of the museum, added, “The giant Megalodon vertebrae are of great importance because size matters when it comes to understanding the biology, ecological impact, and geographic distribution pattern of this extinct giant predator.” “The Gram claypit site also represents the scientifically verifiable latitudinally highest Megalodon locality in the world, which does not contradict the previous observation that larger Megalodon remains are more common in ‘cooler’ regions relative to ‘warmer’ regions,” Elstrup continued.
The research team took the study one step further by analyzing incremental ‘growth bands’ putatively formed annually (analogous to tree rings) in the Megalodon vertebrae using micro-CT imaging, a non-destructive X-ray-based technique. The micro-CT images revealed that the Megalodon individual was at least 64 years old when it died, with a possible theoretical longevity of 96 years old based on a growth model the team attained for that shark.
Lauridsen, an associate professor at Aarhus University, who performed the micro-CT scanning, noted, “Scanning the large, low-contrast vertebrae fossils surrounded by clay at ultra-high resolution was a real technical challenge, which resulted in generating more than 100 GB worth of images.”
The team also made a surprising discovery. Upon closer inspection, the rocks surrounding the Megalodon vertebrae were found to contain many fragmentary gill-associated structures and tiny scales of another shark, the basking shark. Although the basking shark can grow to substantial sizes, the researchers ruled out the possibility that the vertebrae belong to the basking shark, because basking shark vertebrae are proportionally much longer than wider relative to Megalodon vertebrae and have been found in the same quarry.
“This led us to interpret the basking shark elements to represent the stomach contents of the Megalodon, which is the first documentation for the Megalodon fossil record,” stated another coauthor, Mikael Siversson, who is a paleontologist at Western Australian Museum in Welshpool.
Deciphering the body size of large extinct carnivores like Megalodon, that must have had a significant impact on its ecosystem, is important in the context of ecology and evolution.
“Although our growth model suggests that Megalodon could have theoretically grown even slightly larger, the length of 24.3 meters is currently the largest possible scientifically justifiable estimate for O. megalodon,” said Shimada.
This new study, “Rediscovery of the associated gigantic vertebrae of the extinct megatooth shark, Otodus megalodon, from the Upper Miocene Gram Formation in Denmark, and comments on its paleobiological significance and the maximum possible size of the species” authored by Shimada, Elstrup, Lauridsen, Sørensen, and Siversson will appear in the forthcoming issue of Palaeontologia Electronica and will be available online 12:01AM GMT on Monday, June 29, 2026 (= 8:01PM EST on Sunday, June 28).
Tentative body outline of 24.3-meter-long (80-foot-long) extinct megatooth shark, Otodus megalodon, for which the estimated length is based on the 10.8-million-year-old fossilvertebral specimen from the Gram Formation of Denmark featured in the new study.
Important notes: 1) the exact shape, size, and position of most fins remain unknown based on the present fossil record; and 2) an adult human (Homo sapiens) is depicted for size comparison, but it must be emphasized that the two species never coexisted.
Rediscovery of the associated gigantic vertebrae of the extinct megatooth shark, Otodus megalodon, from the Upper Miocene Gram Formation in Denmark, and comments on its paleobiological significance and the maximum possible size of the species
Article Publication Date
28-Jun-2026
Ultrasound propagation in porous rocks: Theory identifies three distinct wave modes
Tsukuba, Japan—Ultrasound-based irradiation of rock formations has attracted considerable attention as a technique for enhancing heavy-oil (high-viscosity crude oil) recovery from deep underground reservoirs. However, a unified theoretical framework for wave propagation and energy dissipation in these formations remains lacking because water coexists with heavy oil within rock pores and gas bubbles in the water respond dynamically to ultrasonic excitation, thereby creating a complex system. Conventional theories typically treat oil as a purely viscous (Newtonian) fluid or assume frequency ranges markedly below the ultrasonic regime. Consequently, these theories inadequately capture oil viscoelasticity and the influence of bubble oscillations in the ultrasonic regime.
This study extends previous low-frequency models and constructs a theoretical framework applicable to ultrasonic frequencies by incorporating three notable elements into a unified system of equations: (i) heavy-oil viscoelasticity, (ii) dynamic capillary pressure at fluid-fluid interfaces, and (iii) oscillations of gas bubbles dispersed in water induced by ultrasonic pressure fluctuations. This framework analyzes wave velocities and frequency-dependent attenuation. The results reveal the coexistence of three longitudinal-wave types with distinct physical origins: a fast-propagating mode, strongly attenuated mode arising from relative motion between fluids and the rock matrix, and slow mode governed primarily by capillary dynamics at fluid interfaces.
These findings provide a theoretical basis for understanding and predicting ultrasonic wave behavior in multiphase porous media across a wide frequency range. The results are expected to support optimized strategy development depending on the intended application, such as selecting lower frequencies for wider spatial coverage and higher frequencies to exploit localized interfacial and viscoelastic effects.
### This study was partially supported by JSPS KAKENHI (No. 22K03898) from the Japan Society for the Promotion of Science, and JKA and its promotion funds from KEIRIN RACE. This work was also partially supported by the Top Runners in Strategy of Transborder Advanced Research (TRiSTAR) program conducted as part of the Strategic Professional Development Program for Young Researchers by MEXT.
Original Paper
Title of original paper: Ultrasound propagation in multiphase porous media: A continuum-mechanical model for coupled effects of bubble dynamics and oil viscoelasticity
To counteract the adverse effects induced by chronic stress, individuals often engage in behaviors that activate the brain's reward system, exerting compensatory regulation over emotional states. The consumption of palatable food represents a simple yet effective strategy for alleviating stress-induced anxiety. However, the underlying neural circuit mechanisms linking reward processing to stress regulation remain largely unclear.
In a study published in Advanced Science, Dr. TU Jie's team from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences identified a neural circuit from dopamine 1 receptors (D1R) neurons in prefrontal cortex (PFC) to corticotropin-releasing factor (CRF) neurons in paraventricular nucleus (PVN) of hypothalamus—PFCD1R→peri-PVNCRFR1→PVNCRF—that functionally connects the brain's reward system with the stress-response system and mediates reward-driven top-down regulation of stress.
Using both high-resolution three-dimensional (3D) behavioral mapping and conventional behavioral assays, researchers demonstrated that chronic stress induces the hyperactivation of PVNCRF neurons and produces anxiety-like behaviors in mice. Notably, the intake of palatable food reversed these neural and behavioral abnormalities.
Through in vivo neural activity recordings, researchers revealed that palatable food consumption triggers dopamine release within the PFC, leading to the activation of excitatory D1R-expressing neurons, and these PFCD1R neurons, in turn, suppress the stress-induced hyperactivity of PVNCRF neurons.
Because PFCD1R neurons are excitatory, researchers hypothesized that the inhibitory regulation of PVNCRF neurons require an intermediate inhibitory relay. Besides, they identified CRFR1-expressing neurons in the peri-PVN region as the critical relay node mediating this effect.
The findings of this work provide important insights into how reward-related experiences modulate stress responses and emotional homeostasis.
Sight-threatening antibiotic-resistant eye infections are becoming a significant threat to vision in dogs, cats, and horses, according to a newly published comprehensive review. The study examines global trends in antimicrobial resistance in animal eye infections and warns that multidrug-resistant bacteria are becoming more common in referral veterinary settings. The review also highlights a critical challenge for veterinarians: standard laboratory tests may not always predict how well topical eye treatments will work in practice. The authors call for earlier diagnostic testing, more targeted antibiotic use, stronger infection-control measures, and the development of antibiotic-sparing strategies to help preserve treatment options for future patients.
Sight-threatening eye infections in pets and horses are becoming more difficult to treat as antibiotic-resistant bacteria spread worldwide, according to a new review published in Veterinary Ophthalmology by researchers from the Hebrew University of Jerusalem.
The review by Dr. Lionel Sebbag and Dr. Oren Pe'er of the Koret School of Veterinary Medicine, Hebrew University of Jerusalem, examines the growing challenge of antimicrobial resistance (AMR) in veterinary ophthalmology, with a particular focus on bacterial corneal infections that can threaten vision within hours or days if left uncontrolled.
Bacterial keratitis, a serious infection of the cornea, is among the most urgent emergencies in veterinary eye care. While antibiotics remain the cornerstone of treatment, the researchers found mounting evidence that many of the bacteria responsible for these infections are becoming increasingly resistant to commonly used drugs.
Drawing on studies from North America, Europe, Asia, South America, and Australia, the review identifies Staphylococcus pseudintermedius, beta-hemolytic streptococci, and Pseudomonas aeruginosa as the most frequently isolated bacterial pathogens in companion animals. Particularly concerning is the rising prevalence of multidrug-resistant strains, especially in referral and specialty-care settings where the most severe cases are concentrated.
One of the most consistent findings across studies was the impact of previous antibiotic use. Animals that had recently received topical antimicrobial treatment were more likely to harbor resistant bacteria and less likely to yield positive culture results, making accurate diagnosis and targeted treatment more challenging.
The review also highlights a surprising gap between laboratory testing and real-world clinical outcomes. Standard antimicrobial susceptibility tests are largely based on how antibiotics behave when administered systemically, yet eye drops achieve very different drug concentrations at the ocular surface. As a result, laboratory susceptibility reports may not always accurately predict whether a treatment will succeed or fail in clinical practice.
“Antimicrobial resistance is no longer a theoretical concern in veterinary ophthalmology,” the authors note. “It is a clinically significant and evolving reality.”
The researchers argue that laboratory findings should always be interpreted alongside clinical observations, disease severity, and patient history. They emphasize the importance of obtaining microbiological samples before extensive antibiotic treatment whenever possible, allowing veterinarians to make more informed treatment decisions.
Beyond the immediate clinical implications, the review places antibiotic-resistant eye infections within a broader One Health framework. Some bacterial species commonly found in animal eye infections have recognized zoonotic potential, meaning they can be transmitted between animals and humans. The authors note that veterinary clinics, equipment, and even households can serve as environments where resistant organisms circulate, highlighting the importance of rigorous hygiene and infection-control practices.
Looking ahead, the review explores a range of antibiotic-sparing approaches designed to reduce reliance on traditional antimicrobials. These include antiseptic therapies, biofilm-disrupting treatments, corneal cross-linking technologies, ultraviolet-based approaches, and other emerging methods that may complement conventional antibiotic therapy.
The authors conclude that preserving the effectiveness of existing antibiotics will require coordinated efforts in surveillance, antimicrobial stewardship, infection control, and the development of ophthalmology-specific guidelines for managing ocular infections.
“The goal is not simply to resolve the current infection,” the authors write, “but to preserve therapeutic reliability for future patients.”
