Asymmetrical features associated with anger

Don’t anger the asymmetric

After you read this piece, you will probably break out the measuring tape and try to figure out how prone to anger you are, because recent research indicates that anger can be measured in inches.

Using a clever ruse, researchers at Ohio State University found in 2004 that the more asymmetrical a person is in some physical features, the more likely that person is to become angry at rejection. In addition, the scientists found a role for testosterone and sex in these responses.

They duped 51 men and 49 women into thinking that they were attempting to raise money for a (false) charity. Participants had to make two phone calls in an effort to obtain a donation and expected to receive a reward if they were successful. Instead of the person on the other end of the phone being someone in the middle of his dinner, it was really a researcher, pretending to be a solicitee. At the first phone call, the solicitee pretended to be sympathetic, but politely said that he or she had no money to give. For the second phone call, the responder behaved rudely, saying the donation would be a waste of money. The first response was considered a low-provocation incident, and the second a high-provocation response.

Who hangs up phones any more?

When the unknowing study participants hung up the phone, the force of their hang-up was measured, as were their testosterone levels. Additionally, after the exercise, they had a choice of three letters to send to the people they had called; one letter was polite, one moderately pleasant, and the third accusatory and angry.

After collecting data on the ankles, foot width, ear height and width, palms, wrists, and fingers of the participants, the researchers looked for correlations between asymmetry of these characteristics and an angry response, as measured by the force of the telephone hang-up. They found that asymmetrical people became angrier and slammed the receiver more than symmetrical people. In addition, asymmetrical men hung up with more force under the low-provocation scenario, and asymmetrical women hung up with more force after confronting the rude responder.

Oh, testosterone and anger again?

Testosterone levels also played a role, with higher levels causing a more pronounced anger response, and again, the response showed a sex-bias. High-testosterone men were more likely to hang up forcefully after the low-provocation incident, and high-testosterone women after the high-provocation scenario.

What does it all mean? Are the asymmetric people sensitive to rejection, and thus, easily angered by it? Perhaps. But the researchers hypothesize that stress during embryonic development disrupts the embryo on several levels, from physical symmetry to neuronal connections. Scientists have long thought that shifts from symmetry during embryonic development—for example, the right-hand fingers developing a greater length than the left-hand fingers—occur because stressors send developmental signals awry. If the signals operate and are received correctly, both sides should develop the same way; but cigarette smoke, alcohol, and other stressors can disrupt these signals, and asymmetry—and quick anger—can be the result.

Testosterone and asymmetry

One intriguing finding of the study was that the asymmetry results reflected the testosterone levels of the participants. This outcome brings questions of the relationships among the hormonal parameters of development, their disruption, and later manifestations of these interactions.

If you’re wondering why men got so angry with the polite responder and women more so with the rude responder, here’s the researchers’ explanation: Men are quick to react with anger, but are not as comfortable as women with high-anxiety situations. So, when the tension amps up, men back off, but women may actually become more aggressive.

And those letters? More than a third of the participants wanted to send the rudest letter, regardless of their sex or levels of symmetry or testosterone. Perhaps they were merely foreshadowing the anger that now pervades American politics today.

With clones like these, who needs anemones?

Finding Nemo makes marine biologists of us all

I once lived a block away from a beach in Northern California, and when my sons and I wandered the sands at low tide, we often saw sea anemones attached to the rocks, closed up and looking much like rocks themselves, waiting for the water to return. My sons, fans of Finding Nemo, still find these animals intriguing because of their association with a cartoon clownfish, but as it turns out, these brainless organisms have a few lessons to teach the grownups about the art of war.

Attack of the clones

Anemones, which look like plants that open and close with the rise and fall of the tides, are really animals from the phylum Cnidaria, which makes them close relatives of corals and jellyfish. Although they do provide a home for clownfish in a mutualistic relationship, where both the clownfish and the anemone benefit from the association, anemones are predators. They consist primarily of their stinging tentacles and a central mouth that allows them to eat fish, mussels, plankton, and marine worms.

Although anemones seem to be adhered permanently to rocks, they can, in fact, move around. Anemones have a “foot” that they use to attach to objects, but they also can be free-swimming, which comes in handy in the art of sea anemone warfare. (To see them in action, click on video, above.)

Sea anemone warfare could well be characterized as an attack of the clones. These animals reproduce by a process called lateral fission, in which new anemones grow by mitosis from an existing anemone, although they can engage in sexual reproduction when necessary. But when a colony of anemones is engaged in a battle, it consists entirely of genetically identical clones.

Yet even though they are identical, these clones, like the genetically identical cells in your liver and your heart, have different jobs to do in anemone warfare. Scientists have known that anemones can be aggressive with one another, tossing around stinging cells as their weapons of choice in battle. But observing groups of anemones in their natural environment is almost impossible because the creatures only fight at high tide, masked by the waves.

To solve this problem, a group of California researchers took a rock with two clone tribes of anemones on it into the lab and created their own, controlled high and low tides. What they saw astonished them. The clones, although identical, appeared to have different jobs and assorted themselves in different positions depending on their role in the colony.

Battle arms, or “acrorhagi”

The warring groups had a clearly marked demilitarized zone on the rock, a border region that researchers say can be maintained for long periods in the wild. When the tide is high, though, one group of clones will send out scouts, anemones that venture into the border area in an apparent bid to expand the territory for the colony. When the opposition colony senses the presence of the scouts, its warriors go into action, puffing up large specialized battle arms called acrorhagi, tripling their body length, and firing off salvos of stinging cells at the adventuresome scouts. Even warriors as far as four rows back get into the action, rearing up the toss cells and defend their territory.

In the midst of this battle, the reproductive clones hunker down in the center of the colony, protected and able to produce more clones. Clones differentiate into warriors or scouts or reproducers based on environmental signals interacting with their genes; every clonal group has a different response to these signals and arranges its armies in different permutations.

Poor Stumpy

Warriors very rarely win a battle, and typically, the anemones maintained their territories rather than achieving any major expansions. The scouts appear to run the greatest risk; one hapless scout from the lab studies, whom the researchers nicknamed Stumpy, was so aggressive in its explorations that when it returned to its home colony, it was attacked by its own clones. Researchers speculated that it bore far too many foreign stinging cells sustained in the attacks, thus resulting in a case of mistaken identity for poor Stumpy.

Crazy cat lady may have microbe to blame

Toxoplasma gondii is the cat-borne parasite responsible for causing toxoplasmosis and a host of other problems in humans. This close relative of the malaria-causing protozoan may drive human behavior and immunity, in addition to causing acute illness and devastating birth defects. Recent research points to a single gene underlying this parasite’s virulence in the human host. It’s scary yet fascinating to think that a single gene from a single organism could have such dramatic effects on our species.

Warning pregnant women away from litter boxes

Because T. gondii infection can result in serious fetal defects, many pregnant women have heard of toxoplasmosis, an illness that often goes unnoticed in the afflicted person. Pregnant women are warned away from cat litter boxes and even away from gardening because contact with cat feces can mean contact with the parasite. T. gondii spends the sexual part of its life cycle in cats, but for its asexual life, it can parasitize a number of hosts, from pigs to lambs to mice to people. People also can acquire the infection from eating undercooked meat or drinking contaminated water. In some countries, like Brazil, up to 60% of the population has been exposed to T. gondii; in the United States, about 33% of people tested have antibodies to the parasite, indicating past infection.

Link between parasite and schizophrenia

The “crazy cat lady” has practically become a social stereotype in the United States and other countries, conjuring the image of a woman who lives with 25 cats and talks to herself a lot. But researchers investigating schizophrenia have actually identified a potential link between people who are exposed to Toxoplasma infection and the manifestations of schizophrenia; for example, several studies have identified higher levels of antibodies to the parasite in people with schizophrenia, and infection with Toxoplasma can cause damage to brain cells that is similar to the damage seen in patients with schizophrenia. Toxoplasmosis can also sometimes lead to symptoms of psychosis.

The fact is that most people don’t know they have toxoplasmosis because they have healthy immune systems. In people with compromised immunity, however, such as those with HIV, T. gondii can precipitate an extreme form of dementia that eventually kills them. The dementia is so severe that the sufferer eventually becomes completely unaware of his or her surroundings and lapses into a coma. The bug, however, also can affect the central nervous system in healthy people and is also linked to severe eye problems even in patients who are not immunocompromised. One researcher has claimed that infection with the parasite makes men dumber and women act like “sex kittens.”

ROP18: Watch out for this one

There are different strains of T. gondii, and investigators have noted that the Type 1 strain is most closely associated with disease. Studies of T. gondii, which has a genome with about 6000 genes, have pinpointed the virulence capacity of the strain to a single gene, dubbed ROP18. This gene encodes a kinase, one of a huge class of cell signaling proteins that add phosphates to molecules. Typically in cell signaling, kinases exist in a series, phosphorylating the next protein in the pathway, which helps maintain regulation of the signaling. The most virulent T. gondii strains have a form of the gene that differs from that carried by benign strains. Researchers speculate that this kinase interferes with a cell’s normal signaling, hijacking it for its own purposes, including growth and reproduction. The good news is that because kinases are so important in cell signaling, pharmaceutical companies have developed libraries of molecules that inhibit specific kinases, so one potential path to preventing toxoplasmosis is to discover an inhibitor of ROP18.

Rats get a little nutty from it, too

Not only has this parasite been linked to the ability to alter human behavior, but it also appears to alter rodent behavior in ways that favor its own reproduction. For example, rodents exposed to toxoplasma via cat feces actually become more likely to hang out near cat urine. If a cat eats the infected animal, the toxoplasmosis bug can then move into the sexual phase of its life cycle in the cat.

Magnetic fields and the Q

Sorry, not for Trekkies. This Q is chemical.

People have been concerned for years about magnetic fields having adverse health effects–or even have peddled magnets as being health beneficial. But although scientists have demonstrated repeatedly a chemical response to magnetic fields, no one has ever shown the magnetic fields directly affecting an organism.

The earth’s core is weakly magnetic, the result of the attraction between electric currents moving in the same direction. Nature presents plenty of examples of animals that appear to use magnetic fields. Some bacteria can detect the fields and use them for movement. Birds appear to use magnetic fields to navigate, and researchers have shown that attaching magnets to birds interferes with their ability to navigate. Honey bees become confused in their dances when the earth’s magnetic fields fluctuate, and even amphibians appear to use magnetism for navigation. But no one has clearly demonstrated the mechanism by which animals sense and use magnetic fields.

Do pigeons use a compass?

Some research points to birds using tiny magnetic particles in their beaks to fly the right way. But these particles don’t tell the birds which way is north; they simply help the bird create a topographical map in its head of the earth over which it flies. The magnetic particles tell a pigeon there’s a mountain below, but not that the mountain is to the north. The conundrum has been to figure out how the pigeon knows which way is north in the absence of other pointers, such as constellations.

The answer to the conundrum lies with the bacteria. Scientists in the UK have used the purple bacterium Rhodobacter sphaeroides to examine what magnetic fields do at the molecular level. These bacteria are photosynthetic, and absorb light to convert to energy in the same way plants do. The absorbed light triggers a set of reactions that carry energy via electrons to the reaction center, where a pigment traps it. Under normal conditions, as the pigment traps the energy, it also almost instantaneously converts it to a stable, safe form, but sometimes the energy can form an excited molecule that can be biologically dangerous. As it turns out, these reactive molecules may be sensitive to magnetic fields.

A radical pair…or dangerous triplet

A chemical mechanism called the “Radical Pair Mechanism” is the method by which the potentially dangerous molecules can form. In this mechanism, an electron in an excited state may pair with another type of electron in an excited state. If the two excited molecules come together, they can form what is called a “radical pair in a singlet state,” because they are two singlets that have paired. Under normal conditions, this pairing does not happen; in the photosynthetic bacterium, for example, a compound called a quinone (Q) inhibits formation of this pair or of an equally damaging triplet of one electron type or the other.

But when a Q is not present, the singlet or triplet state results. If the triplet forms, it can interact with oxygen to produce a highly reactive, biologically damaging singlet molecule that we know as a “radical.” You have probably heard of radicals in the context of antioxidants—they are the molecules that antioxidants soak up to prevent their causing harm. You may also have heard of carotenoid, a pigment that is an antioxidant. In a normal photosynthetic bacterium, the carotenoids present serve as the Q, the compound that prevents formation of the damaging radical.

A helpful effect of magnetic fields?

Where do magnetic fields come in? Previous work indicated an influence of magnetic fields on triplet formation, and thus, on radical formation. One excellent model to test the effects of fields in a biological system is to remove the Q, the molecular sponge for the triplets, and then apply magnetic fields to see whether triplets—and radicals—form.

That’s exactly what the researchers did, using a mutated form of R. sphaeroides that did not make carotenoids—the Q. The result? The stronger the field, the less radical product was made. They have demonstrated a magnetic field effect in an organism for the first time, and the effect was helpful, not damaging. Their next step, which they are working on, is examining whether or not the bacteria grow better in the presence of the fields.

Ahem. La-la-la-laaaaaa…squeak

It’s true. They can sing

Male mice can sing. They aren’t exactly sitting underneath an open window on a moonlit night, guitar in hand, crooning an evening serenade to their lady love, but apparently, they do sing for the ladies.

Very few mammals sing. In fact, until the mouse discovery, we and whales were the only verified members of the mammalian choir. Scientists knew that mice vocalize; for example, mice that are surprised or in pain can emit sounds that humans can easily hear, under 30 kHz. Newborn mice can make sounds that their mothers recognize, summoning the dams to make them warm or return them to the nest. And male mice make ultrasonic sounds, above 30 kHz, that the human ear cannot hear. Usually, males make these sounds in response to the smell of an available female.

Birds, mice, whales, people

Because humans and whales make pretty large research animals and ethical issues prevent studies with either, research into how language is learned and how the brain transmits messages about language has relied on birdsong. You may not have thought about it much, but the song a bird sings is really a song, containing repeated melody lines or syllables, and the bird can repeat it given the necessary stimulus. But birds also must learn their songs, and the birds they’re trying to attract must be able to understand them. Because of this requirement for learning, birdsong has been the model for how mammals acquire and learn language.

Birds may be catching a break now, thanks to a recent breakthrough in mouse song. Researchers examined the vocalizations of 45 male mice by placing the mice in a recording chamber. The scientists then inserted through a tube a cotton swab soaked in enough female mouse urine to convince the male to burst into song. After recording the mouse’s vocalization, the researchers manipulated the recordings to so that humans could hear them and then analyzed them using software.

Gus-Gus, is that you?

What they report is that the mice appear to be singing actual songs that contain syllables—very rapidly produced syllables at about 10 per second. In addition, the songs had phrases that the animals would repeat. The mice all seemed to have their own individual songs, and almost all 45 mice sang in response to the urine stimulus.

That mice sing at all was discovered by accident, but the finding that they do sing what appear to be genuine songs opens up a multitude of research possibilities. Among directly related questions to address, scientists must examine how females respond to these calls and whether or not different experiences in fetal development affect the song or success of the song. In addition, scientists must try to demonstrate that the songs are truly learned if the mouse is to be used as a mammalian model for mammalian communication, replacing birdsong.

OK, that’s cute, but why is it relevant?

If the mouse song is learned, the animal will become an important model for these studies. Because mice have been used for decades in genetics studies, there are hundreds of different varieties of mice with genes knocked out or knocked in, and researchers can make their own special strains to assess the effects of a particular gene on song structure or production. We may be able to use this model to identify genes directly involved in learning and communication in mammals.

Identifying these genes could lead to investigations of how developmental processes and differences result in differential learning abilities. For example, people who are autistic exhibit altered communication skills. A stronger understanding of the genetics of mammalian communication may help us to unravel the underpinnings of this aspect of autism and other communication disorders.

These findings also lead to another question that remains to be addressed: Are there other animals that sing a secret song that our ears can’t hear?

Batty bigamy and worse

Normally, inbreeding isn’t such a good thing

The idea that three generations of related females might share the same mate is, frankly, abhorrent and strange to us humans, but among bats, this tactic may be a fairly common phenomenon.

Generally, animals avoid inbreeding with one another because doing so results in the development of “inbreeding depression” in a population. This depression refers to falling rates of reproduction and survival that result when relatives interbreed. An example of what happens with inbreeding can be found among the royal houses of Europe in previous centuries. The members of these families would often receive papal dispensations to ignore the rules about consanguinity—close relatedness—to be allowed to marry another royal personage. There just weren’t that many eligible royal folk wandering around Europe and inbreeding was the ultimate result.

Hidden disorders emerge

Because of this inbreeding, often with third or second cousins marrying through several generations, the royal families would manifest disorders that normally would remain hidden. Some of these disorders required the inheritance of two alleles, both carrying mutations, for them to manifest. If the royal families had not constantly been intermarrying, the two recessive alleles would have been much less likely to come together in a single person. As it was, many royal households had children who were sickly, who could not reproduce successfully, or who manifested mental illness or retardation. One particularly notable trait that arose through several families was the “Hapsburg jaw,” a severe underbite and jutting jawbone that traced its way through the European royal chessboard. One potentate had a jaw deformity so severe that he could not chew his food.

Horseshoe bats don’t care

But the greater horseshoe bat appears to be untroubled by such issues of consanguinity, at least in the sense that related females from several generations will mate with the same male. In the world of the horseshoe bat, it pays to be a male bat who attracts a female. If the male attracts the daughter, he has a good chance of also mating with the mother and the grandmother, too. And he may be set for his relatively long bat-life; greater horseshoe bats can live up to 30 years, and females will consistently select the same male for the annual bat mating ritual, which results in a single offspring per female each year.

In spite of this inbreeding and polygyny, in which several females mate with the same male, the females apparently are quite adept at avoiding mating with their own fathers. A female will only mate with her mother’s partner if her mother has switched partners and is no longer mating with the daughter’s father.

Beat that, Belgium

This complex mating web results in a bat family tree that is more confusing than that of all the royal houses of Europe combined. It is possible for a female bat and her maternal half-aunt to be half-sisters on their father’s side.

How did researchers unravel this remarkable complexity? They identified a colony of female bats—who spend most of the year living in single-sex groups—in an old mansion in Great Britain. DNA analysis showed that the several hundred females lived in about 20 groups of related females who shared mates. The females met up with the males, who lived in a permanent stag party condition in a nearby cave, only once a year. Researchers speculate that females use smell to avoid mating with their fathers.

What benefit this interbreeding?

Why risk interbreeding in the first place? Actually, many species exhibit tactics that lead to closer kinship among individuals. Researchers speculate that closer kinships result in better teamwork to protect the genetic investment. In the world of team-playing ants, for example, female siblings can be 75% related, rather than the 50% most sexually producing species share genetically with their siblings. Experts believe that this extra genetic relatedness enhances the teamwork atmosphere of an ant colony. In much the same way, the related groups of female bats work together to raise the young. Researchers believe that this horseshoe bat tactic may extend beyond the greater horseshoe to other bat species.

Can animals sense disaster?

Animals head for the hills when natural disaster looms

People living and working in national parks where the devastating 2006 tsunami hit made a startling observation within a few days of the disaster. They had found no animal carcasses of any kind. It appeared that animals had somehow managed to avoid the killer waves that resulted in the deaths of tens of thousands of people.

In Yala National Park in Sri Lanka, people flying over the area in helicopters observed horrible devastation—uprooted trees, cars upended, cars in trees—everywhere the waves had roared over the 391-square mile preserve. But one thing they didn’t see were the bodies of dead animals. The park is home to Asian elephants, crocodiles, buffalo, monkeys, and leopards, and every animal appeared to have made for the hills before the waves swamped their habitat.

Some turtle carcasses have washed ashore, but they seem to be the only notable wildlife deaths in the region. At an elephant trekking center in Thailand, two elephants named Poker and Thandung suddenly went nuts, broke their chains, and headed for the hills, carrying four lucky Japanese tourists on their backs. The elephants and the tourists survived the waters that flooded over the area five minutes after the elephants broke free.

A long history of doom-detection

A long, but anecdotal, history of animals’ ability to sense doom underscores the observations from this most recent tragedy. As far back as about 400 B.C., we noted unusual animal activity just preceding a natural disaster. The Greek historian Diodorus observed in 383 B.C. that two days before a destructive earthquake, the rats, snakes, weasels and even worms had decamped from the affected city. Worms—dwelling in the ground and possibly well-equipped with underground sensors—also figured in a mass animal exodus recorded prior to the 1755 earthquake in Lisbon, Portugal, the worst natural disaster on record prior to the recent Asian tsunami.

Dogs bark, geese honk, livestock get bull-headed. In the big Alaskan earthquake of 1964, a rancher could not get his cows to stay in the lowland pastures; the stubborn bovines insisted on grazing in the hills. Later that day, a huge earthquake hit, triggering a tsunami that wiped out coastal Alaskan towns, but the cows survived on their hillsides.

Are humans missing a vital organ?

Animals appear to know something’s coming possibly because they have what one researcher has described as sensory organs to detect tiny changes leading up to a big event. We, unrefined creatures that we are, do not detect these micro-changes and live in ignorance until the disaster hits. But proving that animals have something we don’t in this regard is a bit difficult because we can’t recreate earthquakes or tsunamis in the lab. Sure, we could shake a table or wash water over a false beach, but it’s the signals leading up to the events that we strive to understand. Since we cannot detect them, we don’t know what they are, and we can’t re-create them.

Our only chance of gaining some experimental insight into this phenomenon is to rely, as so many scientists do, on solid preparation for sheer chance. A marine biologist on the U.S. east coast has done just that, and in the process has become the first scientist to acquire actual proof that animals respond to impending disaster.

Sharks reveal a bit of the secret

The biologist, Michelle Heupel, had been radiotagging sharks off the coast of Florida when Tropical Storm Gabrielle approached. Six hours before the storm made landfall, all 14 sharks she was monitoring suddenly evacuated their nursery site. She and others believe that the sharks registered the drop in barometric pressure that preceded the storm. The drop made depths feel shallower, and the sharks instinctively swam en masse for deeper waters. Heupel got another chance to monitor this movement when Hurricane Charley swept onto the east coast. Again, the sharks she was monitoring all rapidly exited the area hours before the storm moved in.

Wordless Wednesday: Dolphin diplomacy

(almost wordless…)

Move over, cockroaches. Dolphins have the communication game down to diplomacy:

(Credit: iStockphoto/Stephan Zabel)

Cockroaches are collective food critics

Collective communication guides cockroach dining decisions

Ever drive by a restaurant with an empty parking lot and avoid it yourself because, well, no one else was eating there? If so, you’re not much different from cockroaches. They also appear more attracted to food resources if other cockroaches dine there, as well.

Yes, cockroaches creep me out, too

They’re the only animal about which I’m phobic, but who could resist a story like this? A new study published in Behavioral Ecology and Social Biology has found that cockroaches communicate with each other about preferable food sources, much as people do.  Rather than doing it through visuals of empty parking lots or restaurants or via a critic’s recommendations, however, they probably use pheromones. So, there may be a cockroach pheromone or suite of the chemicals that says, “Hey, this pile of garbage is the best in town!”

The researchers who determined this used a couple of piles of food. The roaches collectively would spend more time and in greater numbers at one pile of food over another. Even more interesting–at least to cockroach researchers–the bugs would linger longer at the dining source if other roaches were there, too. Peer pressure, it appears, is not only a human phenomenon.

It’s not limited only to cockroaches in the insect world, either. There are many other examples of insect chemical communication guiding collective behavior. The most famous is probably the honeybee waggle dance, which the animals use to indicate which way to go to find the best food resources.

Why should we care?

Why would researchers go to the trouble of monitoring cockroach choices over piles of food? One reason is that if we identified the pheromone that communicates “good food pile” to cockroaches, we could use that to lure them into our little pest-control traps. Ever diabolical that way, we humans are. There are some things not even cockroaches can do.

Pesticide link to ADHD

It’s correlation, not causation

A common pesticide and metabolites have been linked in a large study to ADHD, an attention deficit disorder characterized also by hyperactivity and impulsivity. ADHD has previously been associated with specific genes and even hailed as a one-time advantageous evolutionary adaptation. But many neurological differences likely will trace to an interaction of genes and environment, or, in fancy science talk, a multifactorial causality.

But it’s also not a surprise

This study looked at metabolites in the urine of more than 1000 children, 119 of whom had ADHD. It’s not mechanistically outre to think that pesticides designed to send a pest’s nervous system astray might have a similar effect on vertebrate systems. But this study showed links, not mechanisms, which often is a necessary first step to justify further pursuing a hypothesis. The researchers found that levels of specific metabolites of organophosphate pesticides are associated with an increased risk–by as much as two-fold–of developing ADHD.

Join the ever-expanding club

If further research does identify a mechanistic tie to this identified correlation, then these pesticides will join an ever-growing suite of chemicals we’ve introduced into the environment that influence our endocrine and neural systems. These chemicals are called endocrine disruptors.

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