A toxin from one of the world’s most venomous animals could one day help treat diabetes and endocrine disorders. The toxin in snails called consomatin is similar to somatostatin in humans, a peptide hormone that regulates blood sugar. In cone snail venom, consomatin’s specific and long-lasting effects help the animal hunt its prey, but it could also lead to the development of better drugs for sometimes fatal diseases–if we can understand how it works. The findings are detailed in a study published August 20 in the journal Nature Communications.

Fine-tuned venoms

Scientists have previously experimented with using cone snail venoms for creating less addictive opioid alternatives and new diabetes treatments. In 2016, scientists unlocked the structure of a fast-acting insulin that the snails use to stun their prey; a similar structure could be used to create an insulin that works faster in humans. In the new study, consomatin also exhibited enough precision to target single types of molecules. Researchers hope that drugs could be developed with the same amount of precision.

“Venomous animals have, through evolution, fine-tuned venom components to hit a particular target in the prey and disrupt it,” study co-author and University of Utah biochemist Helena Safavi said in a statement. “If you take one individual component out of the venom mixture and look at how it disrupts normal physiology, that pathway is often really relevant in disease.” 

[Related: What is a toxin?]

The team looked at the human hormone somatostatin that prevents the levels of blood sugar in the body from rising to dangerously high levels. The cone snail toxin consomatin also keeps blood sugar levels from increasing, but uses that as a way to stun and kill its prey. However, the team found that consomatin is more chemically stable and longer-lasting than the human hormone. This makes it a particularly promising blueprint for new drugs and treatment. 

In the study, the team looked at one of the most toxic marine cone snail–the geography cone. They are found along reefs in the Pacific and Indo-Pacific, where the snails stun and eat small fish. The team measured how the cone snail’s consomatin interacts with somatostatin’s targets in human cells in a dish. They found that consomatin mingles with one of the same proteins that somatostatin does. While human somatostatin directly interacts with several proteins, consomatin only works with one. This fine-tuned targeting means that the cone snail toxin can affect blood sugar levels and hormones, but not hit the other molecules around it.

According to the team, the cone snail toxin can hit its targets even more precisely than most specific synthetic drugs designed to regulate hormone levels. However, in its current form, the consomatin’s effects on blood sugar could make it dangerous to use to treat diabetes in humans. Studying its structure could help researchers design drugs for endocrine disorders that have fewer side effects in the future.

Earth’s chemists

Consomatin and somatostatin share an evolutionary history. Over millions of years, the cone snail turned its own hormone into a weapon. Importantly, consomatin doesn’t work alone. A 2022 study found that cone snail venom also includes another toxin which resembles insulin. This lowers blood sugar levels so quickly that the cone snail’s prey becomes unresponsive. Consomatin will then keep blood sugar levels from recovering, and the prey will ultimately die. 

[Related: This cone snail’s deadly venom could hold the key to better pain meds.]

“Cone snails are just really good chemists,” study co-author and University of Utah postdoctoral researcher Ho Yan Yeung said in a statement. “We think the cone snail developed this highly selective toxin to work together with the insulin-like toxin to bring down blood glucose to a really low level.”

Since several parts of the cone snail’s venom target blood sugar regulation, the venom may have other molecules with similar functions, including regulating glucose properties. A better understanding of the process at the molecular level could then be used to design better medications. 

The post Precise, lethal sea snail toxin could one day lead to better medicines appeared first on Popular Science.

Among the numerous snakes on planet Earth, pythons are well known for their incredible ability to swallow their prey whole. Some python species have been spotted taking down deer, cows, and even alligators, but they don’t generally eat every single day the way that most animals do. While scientists have observed their eating patterns for decades, less is known about how this affects their hearts. It turns out that to eat this way, pythons rapidly increase their heart rate, body mass, and energy output just for a meal. 

A study published August 19 in the journal Proceedings of the National Academy of Sciences (PNAS) found that python hearts appear to become less stiff, even while the blood pumping muscle is doing the work required to eat such a large meal. With more research, understanding how the python heart does this could be applied to heart diseases in humans one day. 

Feasting and fasting

In the wild, pythons must often go for months at a time without eating due to food scarcity. When they do eventually find food, they will really go for it and often eat a meal that can equal their body mass.

[Related: Scientists propose eating more python.]

“It [is] crucial to their survival to be able to have long fasting periods that are not harmful to them and to be able to consume these large meals intermittently,” study co-author and University of Colorado biologist Leslie Leinwand tells Popular Science. “One adaptive response to such a lifestyle is that almost all of the organs in their body get much larger in the first week after such meal consumption and after the meal is consumed, their organs shrink back to a little bigger than their fasting size.”

To learn more about the effects that their feeding style has on their bodies, Leinwand and the team compared the hearts of ball pythons (Python regius). One group of pythons had fasted for 28 days. The other group ate a meal of whole rats that were equivalent to a quarter of the snake’s body mass. 

Compared with the hearts of pythons who hadn’t eaten, the fed pythons increased their own mass by close to 25 percent after eating. The general structure of the heart was mostly unchanged after meals. 

In the fed pythons, the cardiac myofibrils–individual units in cardiac muscle cells that help the heart contract–had generated more force to eat. The cardiac myofibrils also relaxed more slowly and were less tense than myofibrils in the hearts of fasted pythons. The chromatin in the heart muscle cells that alters how genes respond to physiological stress in the fed pythons was also less condensed in the fed pythons compared to fasted pythons.

The cardiac ventricle tissues that help the heart pump blood were also less stiff in the fed pythons than the fasted ones. According to the study, it only took 24 hours after eating a large meal for the python heart to become much less stiff.

[Related: Stressed rattlesnakes just need a little help from their friends.]

Future applications for ‘stiff’ hearts

Stiffness in the heart can be troublesome in animal hearts because it can prevent blood from flowing properly. In humans, cardiac amyloidosis or “stiff heart syndrome” can lead to abnormal heartbeats and faulty heart signals. For pythons, their hearts appear to be avoiding the pitfalls of a stiff heart. Their hearts become much more stretchy while still producing the immense forces required to eat their prey. 

“We have shown that this organ size increase is what we call physiological–or healthy,” says Leinwend. “In the heart, such an increase is what is seen in highly conditioned athletes.”

However, there is still more research needed to determine how this can be used to help human hearts.

“If we could apply the biology of pythons that do this healthy thing in their hearts, it could be very helpful to people with heart disease,” says Leinwend. “There is a lot of fascinating biology in the world that can lead to better understanding and treatment of disease.”

The post How pythons can eat such giant meals appeared first on Popular Science.

The dodo is one of the most iconic—and misunderstood—extinct animals. Four hundred years after its extinction, the popular narrative remains that the flightless bird was simply too dumb, slow, and ungainly to withstand modern society’s arrival to its native island of Mauritius. But researchers are seeking justice for the unfairly maligned dodo and its extinct relative, the solitaire, by synthesizing centuries of scientific literature, historical accounts, and biological information into a single work providing clarification and revised taxonomic records.

In a study published in the August 2024 issue of Zoological Journal of the Linnean Society, a team collaborating between the University of Southampton, Oxford University, and the Natural History Museum attempted to correct the record for Raphus cucullatus. According to an accompanying August 16 announcement, the paper represents “the most comprehensive review of the taxonomy of the Dodo and its closest relative, the Rodriguez Island Solitaire.” Neil Gostling, the study’s supervising author and University of Southampton professor of evolution and paleobiology, argues that most people’s idea of the dodo isn’t simply inaccurate—it ignores the larger issues behind its extinction.

“If you picture the dodo, you picture… this dumpy, slightly stupid bird that kind of deserved to go extinct. That’s not the case,” Gostling says in a university video profile. “It was neither fat nor stupid, it was adapted to the ecosystem in the isle of Mauritius that it had been living in for millions of years.”

What the dodo and its sister species, the Rodrigues solitaire, were not adapted for, however, was the violent, colonizing force of modern society. Dutch sailors first encountered the dodo in 1598 after arriving on the island, located roughly 705 miles east of Madagascar in the Indian Ocean. Having evolved without any significant predators, the birds had no instinctual wariness of humans, making them easy prey for both hungry ship crews and international trade. In less than a century, the dodo was wiped out—but not due to their popularity on menus or in zoos.

The dodo’s main enemies weren’t humans themselves, but everything they brought with them while establishing a provisioning port for the Dutch East India Company on Mauritius. Livestock such as pigs trampled the ground birds’ nests, while rats devoured their eggs and small chicks. Meanwhile, dogs, cats, and other invasive animals preyed on the birds themselves while also competing for the island’s limited food sources. By 1662, the dodo was done. Barely a century later, the Rodrigues solitaire followed it into extinction. And with just 64 years of human documentation of the former, it didn’t take long before bird fact blended with bird fiction.

“The dodo was the first living thing that was recorded as being present and then disappeared,” Gostling said, adding that before their extinction, “it hadn’t been thought possible” that human beings could exert so much influence on the environment.

By the early 19th century, some circles even considered both the dodo and the solitaire “mythological beasts,” added Mark Young, a University of Southampton professor specializing in human transport and paper lead author. During the 1800’s, however, Victorian scientists finally proved both bird species did once exist. But over time, the dodo’s image transitioned largely from an emblem of humanity’s often disastrous environmental impact, to an inaccurate, misunderstood example of “survival of the fittest.” 

[Related: Dodos were actually not that dumb.]

Meanwhile, more than 400 years of subsequent taxonomic confusion led experts to debate just how many dodo and solitaire species originally existed—some biologists argued in favor of three separate variations, while others contended as many as five once roamed the region. These possibilities included the Nazarene Dodo, the White Dodo, and the White Solitaire, among others.

But after a painstaking review of four centuries’ worth of scientific writings and physical remains—including the only surviving dodo soft tissue—Gostling, Young, and their teammates believe they have some answers. Most notably, there were only ever the two species, dodo and solitaire, and they belonged to the columbid family along with pigeons and doves.

As for its “dumpy” reputation, a closer look at its anatomy indicates the dodo was far from a clumsy, slow-moving bird. Skeletal remains studied by the team show that the dodo possessed a tendon in its leg almost the same diameter as the bone itself. This feature can be found today in other avian species known for their speed and climbing agility, indicating the dodo was actually an incredibly fast and active animal.

“Even four centuries later, we have so much to learn about these remarkable birds,” Young said. “The few written accounts of live Dodos say it was a fast-moving animal that loved the forest.”

​​[Related: Is de-extinction only a pipette dream?]

Researchers believe that further reevaluations of the dodo and the solitaire will not only help dispel inaccurate myths, but refocus their legacies. Ultimately, their extinction isn’t the result of any evolutionary failings, but rather the effects of humans when we are at our most environmentally reckless. 

“Dodos held an integral place in their ecosystems. If we understand them, we might be able to support ecosystem recovery in Mauritius, perhaps starting to undo the damage that began with the arrival of humans nearly half a millennium ago,” Gostling explained, adding that, “There are no other birds alive today like these two species of giant ground dove.”

The post The dodo was faster and smarter than you think appeared first on Popular Science.

As the insect sentinels of summer, fireflies use their glowing bellies to communicate to other fireflies. Males from the species Abscondita terminalis use multi-pulse flashes with both of their lanterns to attract females. The females use single-pulse flashes with their one lantern. However, a new study found that some spiders may have decoded this signal and are using it to its advantage. This mimicry is detailed in a study published August 19 in the journal Current Biology.

When orb-weaving spiders (Araneus ventricosus) trap male fireflies in their webs, they manipulate the flashing signals to mimic the typical flashes made by female fireflies. These feigned flashes then lure other males into the web where they become the spider’s next meal. However, we still don’t know if the spider’s venom or a bite itself is manipulating the firefly’s signal. 

[Related: A new theory on why fireflies glow—and why they need help.]

The discovery arose after Xinhua Fu, a study co-author and entomologist at Huazhong Agricultural University in China observed several male fireflies entangled in orb-weaving spider webs while working in the field. He rarely saw a female firefly trapped in a web and additional field trips revealed this sexually skewed pattern. Fu hypothesized that the spiders may be somehow manipulating the fireflies’ behavior to attract others. 

To test this hypothesis that the spiders are manipulating the firefly’s signal, he recruited behavioral ecologists Daiqin Li and Shichang Zhang from Hubei University. The team conducted field experiments where they observed the firefly signals and spider behavior. The observations showed that the spider’s web captured male fireflies more often when the spider was there, compared to when it was away from the web. 

After further analysis, they found that the signals created by male fireflies in webs with spiders present looked more like the signals made by free flying females. The trapped males used single-pulse signals that use only one lantern and not both. 

Interestingly, the ensnared male fireflies very rarely lured other males when they were alone in the web and the spider was not around. This suggests that the males were not altering their flashes as a kind of distress signal. The team believes that the spiders are altering the firefly’s signal.

“While the eyes of orb-web spiders typically support limited spatial acuity, they rely more on temporal acuity rather than spatial acuity for discriminating flash signals,” Li said in a statement. “Upon detecting the bioluminescent signals of ensnared male fireflies, the spider deploys a specialized prey-handling procedure involving repeated wrap-bite attacks.”

[Related: Spider glue might evolve faster than the spiders themselves.]

According to the team, the experiment reveals that some animals are capable of using indirect yet dynamic signaling to go after a very specific category of prey in nature. The team also believes that there could be many other undescribed examples of this kind of mimicry in nature waiting to be uncovered. Predators could be using sound, pheromones, or other means, and not just visual signals to fool their prey. This deceptive ability is not exclusive to the animal kingdom either. The South African daisy appears to trick flies into mating with it and depositing pollen. 

“We propose that in response to seeing the ensnared male fireflies’ bioluminescent signals, the spider deployed a specialized-prey handling procedure based on repeated wrap bite attacks,” the team wrote in the study. “We also hypothesize that the male firefly’s neurotransmitters may generate a female-like flashing pattern.”

However, additional study is needed to determine what exactly is changing in the trapped firefly’s flashing pattern.

The post Spiders may be hacking firefly signals to trap dinner appeared first on Popular Science.

Penguins can’t fly. And while their wings may seem to be purely decorative, these appendages actually play a larger role in their evolutionary history. A fossil penguin species named Pakudyptes hakataramea bridges a gap between penguins that have gone extinct and those living today. Some of its bones show how these wings evolved to help penguins become such speedy swimmers. The findings are described in a study published July 31 in the Journal of the Royal Society of New Zealand. 

Pakudyptes lived in present-day New Zealand’s South Island about 24 million years ago. It was very small, roughly the same size as the little blue penguin–or kororā living today. At only 9.8 inches tall and 2.2 pounds, Pakudyptes are among the smallest known penguin species to ever live on Earth. 

[Related: This human-sized penguin isn’t even the largest ancient penguin we know about.]

Interestingly, Pakudyptes did have the physical adaptations that allowed them to dive into the water, despite being such an early penguin species. In the study, a team of scientists from the University of Otago in New Zealand, and Japan’s Ashoro Museum of Paleontology, Okayama University of Science, and Osaka University examined three bones. The humerus, femur, and ulna were discovered during several field trips in 1987 by the late paleontologist Ewan Fordyce in the Hakataramea Valley, in the Canterbury region of the South Island. 

They found that Pakudyptes fills in a morphological gap between modern and fossil penguins who are now extinct.

“In particular, the shape of the wing bones differed greatly, and the process by which penguin wings came to have their present form and function remained unclear,” study co-author and Ashoro Museum of Paleontology paleontologist Tatsuro Ando said in a statement. 

The humerus and ulna bones show how the penguins’ wings have evolved. 

“Surprisingly, while the shoulder joints of the wing of Pakudyptes were very close to the condition of the present-day penguin, the elbow joints were very similar to those of older types of fossil penguins,” said Ando. “Pakudyptes is the first fossil penguin ever found with this combination, and it is the ‘key’ fossil to unlocking the evolution of penguin wings.”

Otago’s Faculty of Dentistry analyzed the fossil’s internal bone structure alongside data on living penguins from the Okayama University of Science. They found that Pakudyptes had microanatomical features that suggest they could dive. Modern penguins are well known for their excellent swimming abilities. Their bullet-like swimming skills are largely due to the dense, thick bones that add to their buoyancy during diving.

In Pakudyptes, the bone cortex was reasonably thick. However, the medullary cavity–which contains bone marrow–was open. This is similar to the living little blue penguin, which usually swims in shallow waters. 

Pakudyptes’ diving and swimming likely comes down to the distinctive combination of its bones. The humerus and ulna show spots for attachment of muscles and ligaments, which reveal how the wings were used to swim and move underwater. 

[Related: Poop stains reveal four previously unknown Emperor penguin colonies.]

While no longer living, fossil penguins were usually large. Some could reach about 4.5 feet or even 6 feet tall, compared to today’s Emperor penguins that clock in at about three to four feet.

“Penguins evolved rapidly from the Late Oligocene to Early Miocene and Pakudyptes is an important fossil from this period,” study co-author Carolina Loch from Otago’s Faculty of Dentistry said in a statement. “Its small size and unique combination of bones may have contributed to the ecological diversity of modern penguins.”

The post Tiny fossil reveals when penguins evolved their surprisingly useful wings appeared first on Popular Science.

A newly discovered extinct mollusk species that skulked along the ocean floor half a billion years ago is offering new insights into the early days of this diverse group of animals. Fossils from Shishania aculeata indicate that some early mollusks were flat, armored, slug-like creatures that didn’t have the signature shells we see on today’s snails and bivalves. This species was also covered with hollow cone-shaped spines called sclerites. The findings are detailed in a study published August 1 in the journal Science. 

Shishania was discovered thanks to some well-preserved fossils uncovered in the Yunnan Province in southern China. The newly named species dates back to the early Cambrian Period–roughly 514 million years ago. The specimens of Shishania that the team studied are a few centimeters long and the spiky cones are made of chitin. This crunchy material is also found in the shells of modern insects, crabs, and even some mushrooms.  

The fossils that were preserved upside down, indicates that it likely had a muscular foot similar to a slug. Shishania would have used that leg to creep around the seafloor. Unlike most mollusks, it lacked a shell that covered its body. 

[Related: Experience the uncomfortable weirdness of a snail eating fruit.]

Living mollusks come in a wide array of forms–snails, clams, and highly intelligent cephalopods like squids and octopuses. All of this biodiversity developed very quickly during the Cambrian Explosion. This event about 530 million years ago was when all of the major groups of animals were rapidly diversifying. However, due to this accelerated pace of change, few fossils have been left behind to tell the story of early mollusk evolution. The team believes that Shishania represents a very early stage in molluscan evolution.

“Trying to unravel what the common ancestor of animals as different as a squid and oyster looked like is a major challenge for evolutionary biologists and paleontologists–one that can’t be solved by studying only species alive today,” study co-author and University of Oxford in England paleontologist Luke Parry said in a statement. “Shishania gives us a unique view into a time in mollusc evolution for which we have very few fossils, informing us that the very earliest mollusc ancestors were armored spiny slugs, prior to the evolution of the shells that we see in modern snails and clams.”

Shishania’s body was made of soft tissues that typically don’t preserve well in the fossil record. This made the specimens a bit challenging to study, since several were poorly preserved.

“At first I thought that the fossils, which were only about the size of my thumb, were not noticeable, but I saw under a magnifying glass that they seemed strange, spiny, and completely different from any other fossils that I had seen,” Guangxu Zhang, a study co-author and recent PhD graduate from Yunnan University in China who discovered the fossils, said in a statement. “I called it ‘the plastic bag’ initially because it looks like a rotting little plastic bag. When I found more of these fossils and analyzed them in the lab I realized that it was a mollusc.”

Shishania’s spines show an internal system of canals that are less than one hundredth of a millimeter in diameter. The cones were secreted at their base by microvilli–tiny protrusions of cells that increase surface area. Microvilli are found on the human tongue and in the intestines where they help the body absorb food.

“We found microscopic details inside the conical spines covering the body of Shishania that show how they were secreted in life,” said Parry. “This sort of information is incredibly rare, even in exceptionally preserved fossils.”

The team likens Shishania’s method of secreting hard parts to a natural 3D printer that can change its body parts depending on what the animal needs. This method allows several invertebrates to secrete hard parts that do everything from providing defense to helping it scoot around. 

[Related: This taco-shaped critter is a big (evolutionary) deal.]

Chitons–the hard spines and bristles in some modern mollusks–are made of the mineral calcium carbonate instead of the organic chitin that is in Shishania. Similar chitinous bristles can be found in some more obscure groups of animals including brachiopods and bryozoans. These animals along with mollusks and annelids (modern earthworms and their relatives) form the group Lophotrochozoa.
“Shishania tells us that the spines and spicules we see in chitons and aplacophoran mollusks today actually evolved from organic sclerites like those of annelids,” said Parry. “These animals are very different from one another today and so fossils like Shishania tell us what they looked like deep in the past, soon after they had diverged from common ancestors.”

The post A ‘rotting little plastic bag’ was actually a 514 million-year-old fossil appeared first on Popular Science.

In December 2022, Reason reported that both state and federal wildlife agents routinely trespass onto private land and plant cameras. Two Tennessee homeowners successfully sued the state over the practice, and a three-judge panel ruled in their favor. The state appealed the decision, and this week the court of appeals ruled in the homeowners' favor.

At issue is a state law allowing officers of the Tennessee Wildlife Resource Agency (TWRA) to "go upon any property, outside of buildings, posted or otherwise," in order to "enforce all laws relating to wildlife." In the case of Terry Rainwaters and Hunter Hollingsworth, TWRA officers not only entered their respective properties but also installed trail cameras to look for hunting violations, all without a warrant and ignoring "No Trespassing" signs. A lawsuit filed by the Institute for Justice (I.J.) on behalf of Rainwaters and Hollingsworth asked the court to declare the law unconstitutional and issue an injunction against the TWRA, barring it from carrying out any further unwarranted intrusions.

Under the "open-fields doctrine," Supreme Court precedent dating back to Prohibition holds that undeveloped land on someone's property lacks the same rigorous Fourth Amendment protections as their home and the "curtilage," the area immediately surrounding the home.

In March 2022, a three-judge panel from the Benton County Circuit Court ruled in the homeowners' favor, finding that the state constitution provided more protections than the Fourth Amendment. It determined that the state law allowing the TWRA practice created an "intolerable risk" of abuse and was "facially unconstitutional," but it stopped short of issuing an injunction. The state appealed the decision the following month.

In a hearing before the Tennessee Court of Appeals Western Section on June 20, 2023, I.J. attorney Josh Windham argued that the state law is unconstitutionally broad. "It allows TWRA officers to enter and roam around private land, fishing for evidence of crime," Windham said. "It doesn't require consent. It doesn't require warrants. It doesn't require probable cause….It's a blank check for officers to invade private land whenever and however they please."

Amanda Jordan argued for the Tennessee Attorney General's office that the statute was not unconstitutional and that the policy was necessary for the TWRA to do its job. She argued that "it's the particular purpose and function of the TWRA which makes such warrantless entry reasonable."

Judge Jeffrey Usman asked Jordan why, if the state would need a warrant in order to enter someone's property to look for criminal violations, it should not also need a warrant to do the same for civil violations of hunting laws. Jordan agreed that "while normal law enforcement officers would not be able to enter" without a warrant, "you have to look at the state's interest in furthering its duty of protecting and preserving" Tennessee's wildlife.

But Usman pressed further, asking whether the state has "an even stronger interest in protecting persons than wildlife." Further, he asked, "If you can't enter to investigate a crime being committed against a person…why is the interest greater to enter to protect wildlife?"

In a decision issued Thursday, the court of appeals ruled in favor of the property owners. The TWRA claimed that the homeowners' claims of injury were "speculative" as "TWRA agents have not entered the Plaintiffs' lands since September 2018." The court disagreed: Writing for a unanimous court, Usman noted in the decision,

Even if the TWRA has not entered the Plaintiffs' properties since 2018, it continues to assert its power to do so. The TWRA has asserted a continuing right to enter upon the Plaintiffs' properties. At oral argument, the TWRA suggested that if the Plaintiffs want to keep the TWRA off of their land in the future that they should desist in hunting.

"At the most foundational level," the court determined, "the statute is facially constitutional because there are applications of the statute that are constitutionally permissible," including "wild waste land areas." But in this specific scenario, where wildlife agents planted cameras on homeowners' land without ever even pursuing a warrant, the court found the TWRA's actions unconstitutional as applied.

"The TWRA's contention is a disturbing assertion of power on behalf of the government that stands contrary to the foundations of the search protections against arbitrary governmental intrusions in the American legal tradition, generally, and in Tennessee, specifically," Usman wrote. "What the TWRA claims is reasonable is not."

"Our entire theory of the case was vindicated by this decision," Windham tells Reason. "The part that goes against the trial court ruling [says] that the statute can be constitutionally applied to land where people haven't taken any steps to exert control or exert their privacy, which is a rule we don't particularly object to."

The post Tennessee Appeals Court Rules Against Wildlife Agents Who Planted Cameras on Private Land appeared first on Reason.com.