Movies

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

TV Shows

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Music

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Celebrity

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Scandals

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Drama

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Lifestyle

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Health

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Technology

Prolonged interview: Netflix’s Ted Sarandos on moviegoing lately

Prolonged interview: Netflix's Ted Sarandos on moviegoing lately...

Starmer helps to form talks on Ukraine however the trail to peace might be lengthy

Russia, gazing on, teased that this was once...

Mayors name for Keir Starmer to talk over with Calais migrant camps

Michael KeohanBBC Kent, political reporterSimon JonesBBC Information, South...

Tremendous League: Leeds Rhinos 38-24 Castleford Tigers

Leeds: Connor; Lumb, Newman, Handley, Corridor; Gannon, Sinfield;...

Company

Subscribe to newsletter

Inside Updates

Monday, March 3, 2025
Home Blog Page 1650

Robots, like animals, can adapt after injuries

0
Robots, like animals, can adapt after injuries


Robots, like animals, can adapt after injuries
Views of the experimental set-up and parameters. Credit: Journal of The Royal Society Interface (2024). DOI: 10.1098/rsif.2024.0141

Fish fins and insect wings are amazing pieces of natural engineering capable of efficiently moving their owners through water or air. People creating machines to swim or fly have long looked to animals as their models, designing airplanes with wings and boats with fin-shaped rudders. Over the past decades, researchers at Caltech and elsewhere have been exploring bioinspired engineering to see if other natural forms of motion might inform mechanical engineering.

Bio-inspired compensatory strategies for damage to flapping robotic propulsors” was published in the July 3 issue of the Journal of the Royal Society Interface.

Many animals use flapping as a means of propulsion, and robots equipped with flappers can also propel themselves efficiently. But the flappers of the animal kingdom—in this case fish and insects—have another trick up their sleeve. Even with damaged wings or fins, these animals can adapt the mechanics of their motions to compensate. Some species of fish can survive with as much as 76 percent of their fins damaged and still be able to swim.

Could a robotic flapper achieve the same feat? This is the question that inspired a study in the lab of Mory Gharib (Ph.D. ’83), the Hans W. Liepmann Professor of Aeronautics and Medical Engineering, the director and Booth-Kresa Leadership Chair of the Center for Autonomous Systems and Technologies (CAST), and director of the Graduate Aerospace Laboratories at Caltech.

Gharib, together with Meredith Hooper, an aerospace graduate student, and Isabel Scherl, a postdoctoral scholar research associate in mechanical and civil engineering, analyzed a flapping robot’s motions in a tank of oil, which allows for more accurate measurements than water due to its signal-to-noise ratio. They then amputated a portion of the robot’s flapper.






Machine learning for propulsion adaptation

Without intervention, the robot would still be flapping futilely in the tank, having lost its ability to swim. But in addition to bioinspired propulsion, the researchers also gave the robot bioinspired adaptation. Following an injury, fish and insects attempt to propel themselves in new ways, experimenting until they find the stroke mechanics that can return them to full activity.

Mimicking this, the robot was programmed to run repeated trials of various stroke mechanics, which were then evaluated through machine learning. Eventually, the robot, like an injured fish or insect, achieved a successful alternative form of propulsion with its damaged flapper even when 50 percent of it was removed.

“The robot tries swimming in 10 different ways,” Hooper explains. “The forces while it is swimming in the oil tank are measured so that we can compare both the force production and its efficiency. The machine learning algorithm selects the top candidate trajectories based on how well they produced our desired force. The algorithm then comes up with another set of 10 trajectories inspired by the previous set.

“This learning process repeats—evaluation, modification, and creation—until the top candidates are all more or less the same, having learned the most efficient swimming motion for a given force production.”

Robots, like animals, can adapt after injuries
PIV plane and sample image. Credit: Journal of The Royal Society Interface (2024). DOI: 10.1098/rsif.2024.0141

Propulsion adaptation in practice

An autonomous robot is only autonomous until it is not, owing to some type of damage or malfunction. By endowing robotic mechanisms with the ability to adapt to changed capabilities through machine learning, the scope of their autonomy is increased.

As Hooper says, “Autonomous underwater vehicles (AUVs) that provide crucial information about how our oceans work—what exists in the deep sea, how human activities are disrupting ocean dynamics—are very expensive to build and deploy. If an AUV’s propulsion system fails in an inaccessible area without this means of adaptation, it essentially becomes ocean trash. Our finding should increase the probability that an AUV could successfully complete its mission and be recovered.”

“Adaptability through machine learning may also improve the function of micro air vehicles (MAVs) which can navigate small gaps in complex terrain during emergency-response scenarios such as searching for trapped individuals in the aftermath of an earthquake. This type of terrain makes it more likely that the MAV will be damaged during its search. Our finding could make MAVs more robust for deployment in challenging environments where damage could be common,” Hooper says.

Although both the experimental robot and living animals can modify their stroke mechanics to adapt to damage, they do not make the same modifications. Theoretically, in all cases, the flappers (or fins or wings) should change both amplitude and frequency to achieve optimal propulsion after damage. But most studies of fish with fin damage show that the fish increase the amplitude but not necessarily the frequency of their strokes to compensate, while the robot modified both.

“This is most likely due to the effect of evolutionary pressures on fish and insects that aren’t relevant to a robotic use case,” Hooper explains. “How flapping robots best adjust to damage does not necessarily mimic nature.”

More information:
M. L. Hooper et al, Bio-inspired compensatory strategies for damage to flapping robotic propulsors, Journal of The Royal Society Interface (2024). DOI: 10.1098/rsif.2024.0141

Citation:
Robots, like animals, can adapt after injuries (2024, July 31)
retrieved 31 July 2024
from https://techxplore.com/news/2024-07-robots-animals-injuries.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Autonomy boosts college student attendance and performance

0
Autonomy boosts college student attendance and performance


college
Credit: Helena Lopes from Pexels

A new paper from Carnegie Mellon University indicates that giving students more autonomy leads to better attendance and improved performance. The research was published in the journal Science Advances.

In one experiment, students were given the choice to make their own attendance mandatory. Contradicting common faculty beliefs, 90% of students in the initial study chose to do so, committing themselves to attending class reliably or to having their final grades docked. Under this “optional-mandatory attendance” policy, students came to class more reliably than students whose attendance had been mandated.

Student choice in learning

The pattern has held true. In additional studies across five classes that included 60–200 students, 73%–95% opted for mandatory attendance, and at most 10% regretted their decision by the semester’s end.

“Like Ulysses, students know they will face significant temptations. By making their attendance mandatory, they exercise self-control over their future behavior,” said first author Simon Cullen, assistant professor in the Department of Philosophy and Dietrich College AI and Education Fellow.

“We are born curious, and we naturally enjoy mastering many challenging learning tasks, but controlling course policies like mandatory attendance can undermine that motivation.”

The role of autonomy in academic success

According to Cullen, the findings challenge widely held beliefs about student behavior. He continues that many educators worry that given the choice, students would opt for the easiest path possible. However, this study paints a starkly different picture.

“Anytime in a class that you give freedom to choose, you give students the feeling of control over their education,” said Danny Oppenheimer, professor in the Social and Decision Sciences and Psychology departments at CMU and co-author of the article. “It puts the learning in the students’ hands and increases their motivation.”

Preparing students for real-world challenges

A second experiment indicated that when given the option to switch to an easier homework stream at any time before midterms, 85%–90% of students chose to tackle the more challenging work. The “optional-mandatory homework” policy led students to spend more time on their assignments and to learn more over the semester compared to students who were compelled to complete the same work. Cullen gauged the improved understanding of the material by examining how well students did on the problem sets throughout the semester.

These findings suggest that the common practice of imposing strict rules on college students may be counterproductive. Cullen and Oppenheimer found that allowing students more autonomy could lead to better academic outcomes and prepare them more effectively for the real world.

“The thought was that giving them greater control over their own learning would prepare them for the real world,” Cullen said. “Students can be driven to excel in our classes by the same sources of motivation that drive them to pursue countless projects and passions that require no external incentives. But only if we let them choose to learn.”

Enhancing Engagement and Retention in Higher Education

The researchers note their findings also highlight a significant gap in current educational practices. Despite decades of research demonstrating the importance of autonomy to motivation, autonomy-promoting policies remain rare in higher education.

“It’s as if we’ve been ignoring one of the most powerful tools in our educational toolkit,” said Oppenheimer. “By harnessing students’ intrinsic motivation to learn through increased autonomy, we achieve better results than through external pressure.”

The researchers caution that their findings, while promising, have limitations. The study was conducted at a single university with a limited number of students, and more research is needed to determine if the results will replicate across different types of institutions and student populations. The authors are collaborating with a diverse set of institutions to test its broader applicability.

“We’re super excited about these results, but we’re also eager to see how our interventions work across a range of settings,” Cullen said. “We’re particularly interested in exploring how autonomy might benefit students from disadvantaged backgrounds and those with disabilities.”

The study opens up new avenues for research and practical applications in higher education. The authors suggest that similar choice architectures could be applied to other aspects of college courses, such as deadlines, course materials and even exam formats.

“As colleges and universities grapple with issues of student engagement, retention and academic success, this research offers a fresh perspective,” said Cullen. “By trusting students with more control over their education, institutions might not only improve academic outcomes but also foster a more positive and empowering learning environment.”

More information:
Simon Cullen et al, Choosing to learn: The importance of student autonomy in higher education, Science Advances (2024). DOI: 10.1126/sciadv.ado6759

Citation:
Autonomy boosts college student attendance and performance (2024, July 31)
retrieved 31 July 2024
from https://phys.org/news/2024-07-autonomy-boosts-college-student.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Living apart in the second half of life—a necessary evil or a chosen lifestyle?

0
Living apart in the second half of life—a necessary evil or a chosen lifestyle?


Living apart in the second half of life—a necessary evil or a chosen lifestyle?
Proportion of different partnerhship arrangements among people aged 43 and over and proportion of people in a LAT partnership who wish to share a household (in percent) Credit: German Centre of Gerontology

Official statistics only reflect institutional partnership status, meaning that people who live alone in their home are considered to be partnerless. However, if we look at social status, we see that a growing number of people are living in a partnership but in two households of their own. This is referred to as “living-apart-together” (LAT for short).

It is important to investigate this group of people in more detail in order to understand in which respects they are similar to couples living together, for example in terms of a reduced risk of loneliness or a greater sense of well-being, or to people without partners, for example with regard to poverty risks and housing cost burdens.

Just under 6% of the German Aging Survey respondents state that they live in a LAT partnership. But is this living arrangement self-chosen, is it the result of professional and/or private commitments in different locations, for example, or is it a precursor to moving in together?

The researchers approached this aspect by asking the question “And regardless of your circumstances, how much would you like to live in a shared household with your current (married) partner?”

In the entire group of people aged 43 and over, more than half (54.7%) stated that they would like to live in a shared household with their partner. However, there are clear differences according to age: While over 60% of 43- to 65-year-olds would like to live together, only 1in 5 people aged 66 and over (61.7% vs. 20.2%).

This could be due to the fact that older people have lived in their neighborhood for longer and therefore do not want to move, or have already become accustomed to living alone.

“We also looked at differences between women and men, although these are not statistically significant. However, the distributions reflect the results of previous studies that men are more likely to want a partner with whom they live in a shared household and women are more likely to want a partner with whom they can spend their free time, but for whom they do not have to provide in a shared household,” explained Luisa Bischoff, first author of the report.

The study also took into account the distribution of partnership living arrangements in general and the differences according to income level and level of education.

More information:
Luisa Bischoff et al, Neither single nor living together, German Centre of Gerontology (2024). DOI: 10.60922/010h-9c15

Provided by
Deutsches Zentrum für Altersfragen

Citation:
Living apart in the second half of life—a necessary evil or a chosen lifestyle? (2024, July 31)
retrieved 31 July 2024
from https://phys.org/news/2024-07-life-evil-chosen-lifestyle.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Nuclear physicists question origin of radioactive beryllium in the solar system

0
Nuclear physicists question origin of radioactive beryllium in the solar system


Nuclear physicists question origin of radioactive beryllium in the solar system
Exploding stars, such as this one depicted in an artist’s rendering, are unlikely to be responsible for the origin of radioactive beryllium in the solar system, ORNL scientists found. Credit: NASA

Scientists have determined that a rare element found in some of the oldest solids in the solar system, such as meteorites, and previously thought to have been forged in supernova explosions, actually predate such cosmic events, challenging long-held theories about its origin.

Scientists at the Department of Energy’s Oak Ridge National Laboratory led studies of the radioactive isotope beryllium-10, which existed when the solar system came into being some 4.5 to 5 billion years ago. They probed whether this isotope can be formed in sufficient quantities during the massive explosions of gigantic stars in their death throes, called supernovae.

“It is unlikely that such a stellar explosion is the main source for this isotope, as it is observed in the early solar system,” said Raphael Hix, an ORNL nuclear astrophysicist who participated in the study published in the journal Physical Review C. The findings “help us to understand the history of the solar system and the galaxy as a whole.”

The scientists speculate that beryllium-10 is more likely the result of what’s known as cosmic ray spallation—an interaction with the random and ubiquitous high-energy protons and other isotopes, such as carbon-12, that race in all directions throughout the universe at almost the speed of light.

When a star dies, it ejects atoms from its core into the interstellar medium, which is low-density matter that fills the space between stars in a galaxy. The process of making isotopes and elements in stars is referred to as nucleosynthesis. Eventually, portions of the interstellar medium will collect to form the next generation of stars and their associated planets. Included in that atomic soup is carbon-12, which occasionally collides with cosmic rays.

When these high-energy rays collide with carbon-12 atoms, “it literally breaks the nucleus apart, and what’s left can include beryllium-10,” Hix said.

About 4.5 billion years ago, the solar system formed from the collapse of a humongous cloud of gaseous molecules, which created a swirling disk of material known as the solar nebula. Over millions of years, gravity caused the material to coalesce, leading to the formation of the sun and all its planets.

Beryllium-10 has a relatively short half-life—the time taken for half the number of radioactive nuclei to decay—of 1.4 million years. That means any beryllium-10 found on Earth today was created long after the solar system formed.

However, in some meteorites, scientists find boron-10, a decay product of beryllium-10. The presence of boron-10 with nonradioactive beryllium isotopes implies that freshly made beryllium-10 was already present in the solar system when it formed.

Hix and then-postdoctoral researcher Andre Sieverding, now a staff scientist at Lawrence Livermore National Laboratory, used computational resources at DOE’s National Energy Research Scientific Computing Center, or NERSC, to calculate the amounts of different elements and isotopes produced by supernova explosions.

Supernova explosions can occur in stars that are anywhere from 10 to 25 times as massive as the sun. They received help from University of Tennessee undergraduate Daniel Zetterberg working at ORNL, and colleagues at the University of Notre Dame.

If short-lived isotopes, such as beryllium-10, can come from supernova explosions, then, according to prevailing scientific thought, this would support the idea that the formation of the solar system was directly triggered by a supernova.

However, recent calculations challenge this idea, at least for beryllium-10. New data from nuclear experiments, where nuclei are collided to create new nuclei, uncovered nuclear properties that enhance the reaction rate that turns beryllium-10 into other isotopes. This rate replaces an estimate for the reaction rate that is more than 50 years old.

Measuring it in the lab with improved experiments gives a more accurate and detailed picture. The new reaction rates calculated by the scientists are up to 33 times faster than those obtained from prior experiments.

Sieverding, Zetterberg and Hix determined the new rate was fast enough to effectively destroy beryllium-10 in supernovae. As a result, a supernova collapse and explosion “is unlikely to produce enough beryllium-10 to explain the observed beryllium-10 in meteorites,” Hix said.

“This makes it almost certain that spallation really is the source for beryillium-10,” Hix added. “Unless there are major changes in the models for the structure of stars in this mass range, these findings point towards a need for another source of beryllium-10.”

Sieverding said, “As a result, it is unlikely that a supernova was the source of the beryllium-10 in the early solar system.”

The study was a collaboration involving several institutions. ORNL’s Sieverding, Hix and Zetterberg made the astrophysical simulations and nucleosynthesis calculations. At the University of Notre Dame, Jaspreet Randhawa, Tan Ahn and Richard James deBoer interpreted the experimental data to extract the relevant reaction rate.

At the Technical University of Darmstadt in Germany, Riccardo Mancino and Gabriel Martinez-Pinedo made theoretical calculations of reaction rates. Since the rate was too slow to be measured directly, their experiments measured properties of the nuclei, and theorists turned these properties into a reaction rate.

More information:
A. Sieverding et al, Role of low-lying resonances for the Be10(p,α)Li7 reaction rate and implications for the formation of the Solar System, Physical Review C (2022). DOI: 10.1103/PhysRevC.106.015803

Citation:
Nuclear physicists question origin of radioactive beryllium in the solar system (2024, July 31)
retrieved 31 July 2024
from https://phys.org/news/2024-07-nuclear-physicists-radioactive-beryllium-solar.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Who needs males? Female sharks make babies alone in Italy

0
Who needs males? Female sharks make babies alone in Italy


Who needs males? Female sharks make babies alone in Italy
Credit: Scientific Reports (2024). DOI: 10.1038/s41598-024-67804-1

Italian researchers have noted the first case of “virgin birth”, or reproduction without fertilization, in an endangered shark species, a scientific journal reported this week.

The findings published in Scientific Reports concern the first case of the phenomenon in the common smooth-hound shark, Mustelus mustelus, a species threatened by illegal fishing that inhabits the Mediterranean and other warm waters.

Researchers from the Experimental Zooprophylactic Institute of Piedmont, Liguria and the Aosta Valley found that two female M. mustelus sharks under observation in captivity had exhibited parthenogenesis—in which a female can reproduce asexually without the need of sperm to fertilize the egg—each year since 2020.

The two 18-year-old sharks have been at the Cala Gonone Aquarium in Sardinia since 2010.

“Remarkably, this finding reveals that parthenogenesis can occur annually in these sharks, alternating between two females, and conclusively excludes long-term sperm storage as a cause,” the study’s authors wrote.

Cycling parthenogenesis, in which progeny can be born either from fertilized eggs or asexually with unfertilized eggs, occurs in over 15,000 species, yet is not fully understood.

Parthenogenesis, which is more common in invertebrates than vertebrates, has not yet been seen in mammals.

Reptiles and some sharks, rays and skates are able to “modify their adaptive strategy according to the surrounding circumstances”, the authors wrote.

“Although the mechanisms driving parthenogenesis remain unclear, it is suggested that male population reduction could be a pivotal factor,” they said.

Sharks in the wild pose challenges to understanding the phenomenon, but conditions in captivity are ideal for long-term monitoring, they noted.

Aquariums in the United States, United Arab Emirates and Australia have documented the phenomenon in other shark species in the past two decades.

M. mustelus, a midsize shark found in shallower waters that can potentially live up to 25 years, is classified as endangered, with estimates showing the population could decline by as much as a half in the next several decades, according to the study.

The study tracked two 18-year-old female sharks in the aquarium for 13 years, without the presence of males.

“Nonetheless, a nearly annual production of young was observed in the absence of males,” the authors wrote.

The researchers studied the DNA of the offspring to exclude the possibility they were conceived because of long-term storage of sperm by the mothers.

The authors also noted that only one of the sharks born from parthenogenesis at the aquarium is still alive today. The two adults “are in good health”, sharing their large exhibition tank with other Mediterranean marine species.

More information:
Giuseppe Esposito et al, First report of recurrent parthenogenesis as an adaptive reproductive strategy in the endangered common smooth-hound shark Mustelus mustelus, Scientific Reports (2024). DOI: 10.1038/s41598-024-67804-1

© 2024 AFP

Citation:
Who needs males? Female sharks make babies alone in Italy (2024, July 31)
retrieved 31 July 2024
from https://phys.org/news/2024-07-males-female-sharks-babies-italy.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link