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)
Wednesday, April 16, 2025
A bowling revolution: Modeling the perfect conditions for a strike
Conditions from the makeup of the oil on the lane to the subtle asymmetry of a bowling ball can enhance planning for the next strike.
A USBC-approved bowling lane has 39 boards, each measuring approximately 2.73 cm (1.07 in). The x-axis is measured in boards. The y-axis is aligned with the minimum moment of inertia axis of the weight block.
WASHINGTON, April 15, 2025 – With millions of dollars at stake across tournaments and more than 45 million regular annual participants, bowling continues to reign as a top sport in the U.S. A unified model that predicts how a bowling ball behaves down the lane, however, remains elusive.
In AIP Advances, by AIP Publishing, researchers from Princeton, MIT, the University of New Mexico, Loughborough University, and Swarthmore College share a model that identifies the optimal location for bowling ball placement. Employing a system of six differential equations derived from Euler’s equations for a rotating rigid body, their model creates a plot that shows the best conditions for a strike.
“The simulation model we created could become a useful tool for players, coaches, equipment companies and tournament designers,” said author Curtis Hooper. “The ability to accurately predict ball trajectories could lead to the discoveries of new strategies and equipment designs.”
To date, most methods for predicting the outcome of bowling shots have relied on statistics describing real-life bowlers, rather than analyzing the dynamics of the ball and shot itself. Such approaches have often come short when players introduce slight variability in how they bowl.
Instead, the group’s model accounts for a variety factors. One example is the thin layer of oil applied to bowling lanes; the oil layer can vary widely in volume and shape between competitive tournaments, requiring specific styles and targeting strategies for each. The oil is seldom applied uniformly, which creates an uneven friction surface.
The issue is that bowlers and coaches can currently only rely on their own experience and instinct, which Hooper said is often imprecise and suboptimal.
“Our model provides a solution to both of these problems by constructing a bowling model that accurately computes bowling trajectories when given inputs for all significant factors that may affect ball motion,” Hooper said. “A ‘miss-room’ is also calculated to account for human inaccuracies which allows bowlers to find their own optimal targeting strategy.”
Making the model posed several challenges, including how to describe the motion of the subtly asymmetric bowling ball. More challenging still was distilling the inputs required for predicting the trajectory into terms that a bowler or coach could understand and that could be measured with accessories bowlers already use.
In the future, the group aims to improve the model’s accuracy by incorporating even more factors, including uneven bowling lanes, as well as connect with professionals in the industry to better understand how the model may be tailored to fit their applications.
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The article “Using physics simulations to find targeting strategies in competitive tenpin bowling” is authored by Simon Si Ming Ji, Shouzhuo Yang, Wilber Dominguez, Curtis George Hooper, and Cacey Stevens Bester. It will appear in AIP Advances on April 15, 2025 (DOI: 10.1063/5.0247761). After that date, it can be accessed at https://doi.org/10.1063/5.0247761.
ABOUT THE JOURNAL
AIP Advances is an open access journal publishing in all areas of physical sciences—applied, theoretical, and experimental. The inclusive scope of AIP Advances makes it an essential outlet for scientists across the physical sciences. See https://pubs.aip.org/aip/adv.
The Endangered Species Act (ESA), now 50 years old, was once a rare beacon of bipartisan unity, signed into law by President Richard Nixon with near-unanimous political support. Its purpose was clear: protect imperiled species and enable their recovery using the best available science to do so. Yet, as our case study on the grizzly bear in the Greater Yellowstone Ecosystem reveals, wildlife management under the ESA has changed, becoming a political battleground where science is increasingly drowned out by partisan ideology, bureaucratic delays, power struggles, and competing political interests. The survival of the ESA, a wildlife policy mimicked all over the world, may depend on our ability to navigate these waters.
The grizzly bear, a cultural symbol of the American West, embodies this shift. Listed as threatened in 1975 when its numbers dwindled to fewer than 1,000 and its range contracted by 98%, the species has managed to come back from the brink. In the Greater Yellowstone Ecosystem, the population now exceeds 700, a number that surpassed recovery goals set by the federal wildlife management agency tasked with recovery, the US Fish & Wildlife Service. By the ESA’s own metrics, this is a success story, which now means the grizzly bear is eligible for ‘delisting’. Yet, attempts to remove federal protections in 2007 and 2017 were overturned by courts, not because the science was lacking, but because the process has become a lightning rod for political interests.
Our study looks at 750 documents and 2,832 stakeholder quotes to track this politicization. Historically, wildlife management is the strict domain of agency scientists in the executive branch. These scientists are experts trained to interpret interdisciplinary scientific data and balance both human and ecological needs.
Our work shows that today, the most dominant voices belong to legislators, legal advocates, and non-governmental organizations (NGOs) who are increasingly crowding out the agency scientists. Senators, elected politicians, like Wyoming’s John Barrasso proclaim, “The grizzly is fully recovered in Wyoming. End of story,” pushing for state control and criticizing the ESA as sluggish and outdated. Can you blame him though? Senator Barraso advocates for his Wyoming constituents who have collaborated in grizzly recovery and are now on the frontlines of human-wildlife conflict issues where grizzlies might harm livestock or tourists. All the while, population targets set by the ESA have been met, and the species remains listed.
Meanwhile, NGOs and their attorneys, such as the well-known environmental advocacy group Earthjustice, argue that delisting is premature, citing ‘political pressure’ overriding ‘biological evidence.’ The courts, too, have flexed their muscle, with rulings hinging on genetic connectivity’s role in population recovery. Ranchers with increasing grizzly conflict see these scientific developments as intentional delays to delisting rather than advancements in the field of conservation. There are no easy answers.
Wildlife management turned politics
This conflict reveals a stark reality: wildlife management is no longer just about science, it's about who dominates the political discourse, and the power that accompanies it. Legislators see delisting as a way to reclaim state authority from what they consider federal overreach. Their rhetoric, steeped in populist appeals to the Western ranching community, frames grizzlies as a recovered species with bureaucrats in Washington stalling the process of handing management back over to the states.
Montana Senator Steve Daines, for instance, highlights ‘skyrocketing’ livestock losses and bears roaming beyond their historic range. These issues resonate with rural constituents tired of federal wildlife law superseding local management by trusted state agencies. On the other hand, NGOs and legal advocates rely on the courts to maintain federal oversight, warning that state management could unleash ‘trigger-happy’ hunting seasons and jeopardize long-term survival. These advocates argue that we are facing a generational extinction crisis, where every decision we make about imperiled species could approach extinction, a route that we cannot come back from. The public, caught in the middle, may be unaware that conversations over wildlife protection have shifted from credentialed agency biologists and scientists over to politicians.
Our data underscore this shift in power. While executive branch officials, with whom scientific expertise resides, once dominated the discourse (eg fish and wildlife agency personnel at the federal and state level), they are no longer the leading voices in ESA recovery conversations. Elected politicians now lead the charge. Their influence is growing threefold over time compared to scientific agency voices. Legal advocates and NGOs, meanwhile, are shaping the debate over wildlife science with their roles amplified by lawsuits that keep grizzlies listed. Even tribes, historically sidelined, find their strongest platform in court, a sign that political systems still fail to integrate Indigenous perspectives outside litigation.
What’s lost in this debate is the ESA’s original intent: a science-driven process to recover species and then allow federal agency experts to step back so that states, who may better represent local interests, can manage species.
The path forward
This politicization threatens the ESA’s future. When politicians outshout scientists, when courts dictate biology or delay timely management responses, and when recovery becomes a bargaining chip, the law risks losing its credibility with the public. The grizzly saga suggests a path forward: agencies must adapt to this political reality, not retreat from it. Scientists can’t afford to ‘stay out of politics’ when protected species like grizzlies are lightning rods for political debate. Multi-stakeholder groups, like the Interagency Grizzly Bear Committee, offer a model bridging agencies, states, tribes, and NGOs to tackle thorny issues like genetics collaboratively rather than through unending lawsuits in the courts.
The grizzly bear’s fate isn’t just about one species: this pattern is playing out across a range of species in the West and beyond. It will prove itself as the greatest challenge for wildlife managers in an era of increased polarization. If the ESA is to endure another 50 years, it must evolve beyond a scientific ideal into a framework that navigates the messy, human politics of conservation. Otherwise, the grizzly’s roar will be drowned out by an even greater sound: the chaos of our own imperfect politics.
Delisting the Grizzly Bear from the Endangered Species Act: Shifting Politics and Political Discourse in the Greater Yellowstone Ecosystem
Article Publication Date
16-Apr-2025
First study reveals neurotoxic potential of rose-scented citronellol at high exposure levels
Cross-species study using zebrafish, mice, brain organoids, and BBB-on-chip models reveals neurotoxic potential of high-dose citronellol exposure through behavioral and metabolomic analysis
The research team identified the neurotoxic potential of citronellol, a fragrance compound widely used in cosmetics and air fresheners, through a cross-species investigation using zebrafish, mice, human brain organoids, and a blood-brain barrier (BBB) organ-on-chip system.
#1. Neurotoxic Effects: Citronellol exposure led to increased ROS generation, neuroinflammation, and behavioral impairments, including anxiety-like behaviors and altered locomotion, particularly in zebrafish models.
#2. Blood-Brain Barrier Penetration: The study confirmed that citronellol is BBB-permeable, allowing it to accumulate in brain tissue across zebrafish, mice, and organ-on-chip models.
#. Neurochemical Alteration: Metabolomic profiling revealed that citronellol shifts kynurenine metabolism toward the production of 3-hydroxykynurenine (3-HK), a neurotoxic compound, while also affecting key neurosteroids such as progesterone and cortisol.
Credit: Korea Research Institute of Chemical Technology(KRICT)
Citronellol, a rose-scented compound commonly found in cosmetics and household products, has long been considered safe. However, a Korean research team has, for the first time, identified its potential to cause neurotoxicity when excessively exposed.
A collaborative research team led by Dr. Myung Ae Bae at the Korea Research Institute of Chemical Technology (KRICT) and Professors Hae-Chul Park and Suhyun Kim at Korea University has discovered that high concentrations of citronellol can trigger neurological and behavioral toxicity. The study, published in the Journal of Hazardous Materials (Impact Factor: 12.2), employed multiple experimental models across species and used advanced metabolomic profiling to reveal this novel toxicity mechanism.
Citronellol is a naturally occurring fragrance compound derived from plants such as rose, geranium, and citronella. While it has been widely used in products for its floral scent and calming effect, this study revealed that excessive exposure can negatively affect the nervous system.
To ensure the reliability of their findings, the researchers employed four distinct biological models: zebrafish, mice, human brain organoids, and a blood-brain barrier (BBB) organ-on-chip system. The neurotoxic effects of citronellol were evaluated across these systems to confirm cross-species relevance.
In animal models, the team observed that citronellol could penetrate the BBB and accumulate in the brain. This accumulation led to increased generation of reactive oxygen species (ROS) and activation of inflammatory signaling pathways. Both phenomena are known contributors to impaired neurological and behavioral function. The researchers also noted damage to the BBB and the infiltration of immune cells into brain tissue, further exacerbating neuroinflammation.
A key discovery of the study was the alteration of kynurenine metabolism. Kynurenine, a metabolite derived from tryptophan, can be converted into either kynurenic acid, a neuroprotective compound, or 3-hydroxykynurenine (3-HK), which is neurotoxic. The researchers found that citronellol exposure shifted this balance toward the production of 3-HK, thereby enhancing neurotoxic risk.
Notably, zebrafish behavioral tests revealed signs of anxiety and abnormal locomotor activity following exposure to citronellol (2, 4, and 8 mg/L). This included reduced phototactic behavior and increased thigmotaxis, common indicators of stress or neurobehavioral disorders in aquatic models.
Beyond animal testing, the study confirmed similar toxicity mechanisms in human-relevant models. Brain organoids derived from human stem cells and BBB chips both showed evidence of citronellol-induced neurotoxicity and inflammation, suggesting potential risks in humans.
Currently, citronellol is listed by the Korea Ministry of Food and Drug Safety as a potential allergen that must be labeled on cosmetics exceeding certain concentrations, in line with EU regulations. However, its potential neurotoxic effects under high-exposure conditions have not been previously studied.
“This is a representative success case demonstrating the utility of next-generation human-mimicking platforms such as zebrafish and organoids,” the researchers said. Dr. Lee Young-Kuk, President of KRICT, commented, “Through follow-up studies, we plan to use this biomimetic platform to advance human safety assessments and contribute to public health.”
Schematic illustration of neurotoxic mechanism of citronellol.
Credit
Korea Research Institute of Chemical Technology(KRICT)
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KRICT is a non-profit research institute funded by the Korean government. Since its foundation in 1976, KRICT has played a leading role in advancing national chemical technologies in the fields of chemistry, material science, environmental science, and chemical engineering. Now, KRICT is moving forward to become a globally leading research institute tackling the most challenging issues in the field of Chemistry and Engineering and will continue to fulfill its role in developing chemical technologies that benefit the entire world and contribute to maintaining a healthy planet. More detailed information on KRICT can be found at https://www.krict.re.kr/eng/
The study was conducted with support from KRICT’s basic research fund and the Ministry of Environment’s program on the safety management of household chemical products.
Neurotoxic effects of citronellol induced by the conversion of kynurenine to 3-hydroxykynurenine
For a while, crocodile
The ancestors of today’s crocodylians survived two mass extinction events. A new study uncovered a secret to their longevity, which could help conservationists better protect our planet’s most vulnerable species
Some 215 million years ago in what is now northwestern Argentina, the terrestrial crocodylomorph Hemiprotosuchus leali prepares to devour the early mammal relative Chaliminia musteloides.
Most people think of crocodylians as living fossils— stubbornly unchanged, prehistoric relics that have ruled the world’s swampiest corners for millions of years. But their evolutionary history tells a different story, according to new research led by the University of Central Oklahoma (UCO) and the University of Utah.
Crocodylians are surviving members of a 230-million-year lineage called crocodylomorphs, a group that includes living crocodylians (i.e. crocodiles, alligators and gharials) and their many extinct relatives. Crocodylian ancestors persisted through two mass extinction events, a feat requiring evolutionary agility to adapt to a rapidly changed world. The study’s authors discovered that one secret to crocodylian longevity is their remarkably flexible lifestyles, both in what they eat and the habitat in which they get it.
“Lots of groups closely related to crocodylians were more diverse, more abundant, and exhibited different ecologies, yet they all disappeared except these few generalist crocodylians alive today,” said Keegan Melstrom, lead author and assistant professor at UCO, who began the research as a doctoral student at the U. “Extinction and survivorship are two sides of the same coin. Through all mass extinctions, some groups manage to persist and diversify. What can we learn by studying the deeper evolutionary patterns imparted by these events?”
Earth has experienced five mass extinctions in its history. Experts argue that we’re living through a sixth, driven by habitat destruction, invasive species and changing climates. Identifying traits that boost survivorship during planetary upheaval may help scientists and conservationists better protect vulnerable species today.
Historically, the field has regarded mammals as the poster children for understanding mass extinction survival, lauding their generalist diet and ability to thrive in different ecological niches. Despite their resilience, research has largely ignored the crocodylomorph clade. The paper, published on April 16 in the journal Palaeontology, is the first to reconstruct the dietary ecology of crocodylomorphs to identify characteristics that helped some groups persist and thrive through two mass extinctions—the end-Triassic, about 201.4 million years ago (Ma), and the end-Cretaceous, about 66 Ma.
“There’s a danger of trying to draw conclusions from millions of years ago and directly apply it to conservation. We have to be cautious,” said co-author Randy Irmis, curator of paleontology at Natural History Museum of Utah and professor in the U’s Department of Geology & Geophysics. “If people study mammals and reptiles and find the same patterns with respect to extinction survival, then we might predict that species with a generalist diet may do better. That information helps us make predictions, but it’s unlikely we’ll ever be able to pick out which individual species will survive.”
A hidden past of alternative lifestyles
Living crocodylians are famous for being semi-aquatic generalists that thrive in environments like lakes, rivers or marshes, waiting to ambush unsuspecting prey. Picky eaters, they are not. Young ones will snack on anything from tadpoles, insects or crustaceans before graduating to bigger fare, such as fish, baby deer, or even fellow crocs. Yet the uniform lifestyle of today’s crocodylians masks a massive diversity of dietary ecologies in which past crocodylomorphsthrived.
During the Late Triassic Period (237–201.4 Ma) Pseudosuchia, a broader evolutionary group that includes early crocodylomorphs and many other extinct lineages, ruled the land. The earliest crocodylomorphs were small-to-medium-sized creatures that were rare in their ecosystems, and were carnivores that mostly ate small animals. In contrast, other pseudosuchian groups dominated on land, occupied a wide range of ecological roles and exhibited a dizzying diversity of body shapes and sizes.
Despite their dominance, once the end-Triassic extinction hit, no non-crocodylomorphpseudosuchians survived. Whereas hyper-carnivore crocodylomorphs appeared to also die off, the terrestrial generalists made it through. The authors hypothesize that this ability to eat almost anything allowed them to survive, while so many other groups went extinct.
“After that, it goes bananas,” said Melstrom. “Aquatic hypercarnivores, terrestrial generalists, terrestrial hypercarnivores, terrestrial herbivores—crocodylomorphs evolved a massive number of ecological roles throughout the time of the dinosaurs.”
Something happened during the Late Cretaceous Period that set crocodylomorphs on a decline. The lineages specialized for diverse ecologies began to disappear, even the terrestrial generalists. By the end-Cretaceous mass extinction event (punctuated by the meteor that killed the non-avian dinosaurs), most of the survivors are semiaquatic generalists and a group of aquatic carnivores. Today’s 26 species of living crocodylians are nearly all semiaquatic generalists.
Beyond the smile of a crocodile
How do scientists parse the food on multi-million-year-old menus? They analyze the shape of fossilized teeth and skulls to glean the basis of an animal’s diet. A jaw stacked with tiny knives was likely slicing and puncturing flesh. A mortar-and-pestle-like grill probably broke down plant tissue. Skull shape dictates how an animal moves its mouth, providing a clue to its eating habits. Deciphering ancient animal diets reveals where it would have hunted, which the authors call dietary ecology.
It was a massive undertaking. The authors visited zoological and paleontological museum collections across seven countries and four continents to get the fossil specimens they needed. They examined the skulls of 99 extinct crocodylomorph species and 20 living crocodylian species, creating a fossil dataset spanning 230 million years of evolutionary history. The researchers had previously built a database of living non-crocodylians to compare with, including 89 mammals and 47 lizard species. The specimens represented a range of dietary ecologies, from strict carnivores to obligate herbivores, and a wide variety of skull shapes.
As semiaquatic ambush predators, today’s crocodylians mostly occupy similar ecological roles in lots of different environments. They do continue to have remarkably flexible diets, perhaps a remnant of their deeply diverse evolutionary past. For critically endangered crocodylians like the Gharial of the Himalaya foothills or the Cuban Crocodile of the country’s Zapata Swamp, dietary flexibility may give them a chance to persist through our current sixth mass extinction. The biggest challenges facing these species are habitat loss and human hunting.
“When we see living crocodiles and alligators, rather than thinking of ferocious beasts or expensive handbags, I hope people appreciate their amazing 200+ million years of evolution, and how they’ve survived so many tumultuous events in Earth history,” said Irmis. “Crocodylians are equipped to survive many future changes—if we’re willing to help preserve their habitats.”
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Other co-authors include Kathleen Ritterbush of the University of Utah and Kenneth Angielczyk of the Field Museum of Natural History.
The results published in Palaeontology as “For a while, crocodile: crocodylomorph resilience to mass extinctions."
The research was supported by the U.S. National Science Foundation, the Northwest Federation of Mineralogical Societies, the National History Museum of Los Angeles County, the American Museum of Natural History, the Palaeontological Association, the Paleontological Society, the Geological Society of American and the University of Utah Department of Geology & Geophysics.
The teeth of this fossil Borealosuchus skull typify the toothy grin of semi-aquatic generalist predators that survived the end-Cretaceous mass extinction.
Credit
Jack Rodgers/Natural History Museum of Utah
Skulls of Araripesuchus gomesii (left), a Late Cretacious terrestrial predator and Cricosaurus suevicus (right), a Late Jurassic aquatic predator.
