What singing fruit flies can tell us about quick decisions

You wouldn’t hear the mating song of the male fruit fly as you reached for the infested bananas in your kitchen. Yet, the neural activity behind the insect’s amorous call could help scientists understand how you made the quick decision to pull your hand back from the tiny swarm.Male fruit flies base the pitch and tempo of their mating song on the movement and behavior of their desired female, Princeton University researchers have discovered. In the animal kingdom, lusty warblers such as birds typically have a mating song with a stereotyped pattern. A fruit fly’s song, however, is an unordered series of loud purrs and soft drones made by wing vibrations, the researchers reported in the journal Nature. A male adjusts his song in reaction to his specific environment, which in this case is the distance and speed of a female — the faster and farther away she’s moving, the louder he “sings.”While the actors are small, the implications of these findings could be substantial for understanding rapid decision-making, explained corresponding author Mala Murthy, a Princeton assistant professor of molecular biology and the Princeton Neuroscience Institute. Fruit flies are a common model for studying the systems of more advanced beings such as humans, and have the basic components of more complex nervous systems, she said.The researchers have provided a possible tool for studying the neural pathways behind how an organism engaged in a task adjusts its behavior to sudden changes, be it a leopard chasing a zigzagging gazelle, or a commuter navigating stop-and-go traffic, Murthy said. She and her co-authors created a model that could predict a fly’s choice of song in response to its changing environment, and identified the neural pathways involved in these decisions.”Here we have natural courtship behavior and we have this discovery that males are using information about their sensory environment in real time to shape their song. That makes the fly system a unique model to study decision-making in a natural context,” Murthy said.”You can imagine that if a fly can integrate visual information quickly to modulate his song, the way in which it does that is probably a very basic equivalent of how a more complicated animal solves a similar problem,” she said. “To figure out at the level of individual neurons how flies perform sensory-motor integration will give us insight into how a mammalian brain does it and, ultimately, maybe how a human brain does it.”Aravi Samuel, a Harvard University professor of neuroscience who studies the brain and behavior using roundworms and fruit fly larvae, said that the researchers conducted the kind of “rigorous” behavioral analysis that is essential to understanding the brain’s circuitry.”Neuroscience isn’t just making electrical recordings of circuits or finding molecules that affect circuit properties,” said Samuel, who is familiar with the research but had no role in it. “It also is about understanding the behavior itself, from sensory input to motor output. …

Read more

Cultural hitchhiking: How social behavior can affect genetic makeup in dolphins

A UNSW-led team of researchers studying bottlenose dolphins that use sponges as tools has shown that social behaviour can shape the genetic makeup of an animal population in the wild.Some of the dolphins in Shark Bay in Western Australia put conical marine sponges on their rostrums (beaks) when they forage on the sea floor — a non-genetic skill that calves apparently learn from their mother.Lead author, Dr Anna Kopps, says sponging dolphins end up with some genetic similarities because the calves also inherit DNA from their mothers. As well, it is likely that sponging dolphins are descendants of a “sponging Eve,” a female dolphin that first developed the innovation.”Our research shows that social learning should be considered as a possible factor that shapes the genetic structure of a wild animal population,” says Dr Kopps.”It is one of the first studies to show this effect — which is called cultural hitchhiking — in animals other than people.”The study is published in the journal Proceedings of the Royal Society B.Dr Kopps and her colleagues identified individual dolphins in western Shark Bay about 850 kilometres north of Perth. They observed them from a boat as they foraged for food, travelled around the bay, rested, and played with other dolphins.Genetic samples were also taken, and analysed for mitochondrial DNA type, which is only inherited from the mother.It was found that the dolphins that lived in shallow waters, where sponges do not grow, mainly fell into a genetic group called Haplotype H.The dolphins living in deep waters, where sponges do grow, were predominantly Haplotype E or Haplotype F.”This striking geographic distribution of a genetic sequence cannot be explained by chance,” says Dr Kopps, who carried out the research while at UNSW and is now at the University of Groningen.As well, the DNA results from 22 dolphins that both lived in deep water and used sponges as tools showed they were all Haplotype E.”For humans we have known for a long time that culture is an important factor in shaping our genetics. Now we have shown for the first time that a socially transmitted behaviour like tool use can also lead to different genetic characteristics within a single animal population, depending on which habitat they live in,” she says.The team includes UNSW’s Professor Bill Sherwin and researchers from the University of Zurich and Murdoch University.Story Source:The above story is based on materials provided by University of New South Wales. Note: Materials may be edited for content and length.

Read more

Infants using known verbs to learn new nouns: Before infants begin to talk in sentences, they are paying careful attention to conversations

There is a lot that 19-month-old children can’t do: They can’t tie their shoes or get their mittens on the correct hands. But they can use words they do know to learn new ones.New research from Northwestern University demonstrates that even before infants begin to talk in sentences, they are paying careful attention to the way a new word is used in conversations, and they learn new words from this information in sentences.For example, if you take an infant to the zoo and say, “Look at the gorilla” while pointing at the cage, the infant may not know what exactly is being referred to. However, if you say, “Look! The gorilla is eating,” the infant can use the word that they do know — “eating” — to conclude that “gorilla” must refer to the animal and not, for example, the swing she is sitting on.The zoo scenario mirrors the method the researchers used for their experiment. First, infants at ages 15 and 19 months were shown several pairs of pictures on a large screen. Each pair included one new kind of animal and a non-living object. Next, the objects disappeared from view and infants overheard a conversation that included a new word, “blick.” Finally, the two objects re-appeared, and infants heard, for example, “Look at the blick.””After overhearing this new word in conversation, infants who hear a helpful sentence such as ‘the blick is eating’ should look more towards the animal than the other, non-living object,” said Brock Ferguson, a doctoral candidate in psychology at Northwestern and lead author of the study. “We show that by 19 months, they do just that. In contrast, if infants heard the new word in an unhelpful sentence such as ‘the blick is over here’ during the conversation, they don’t focus specifically on the animal because, after all, in this kind of sentence, ‘blick’ could mean anything.”The researchers said many people believe that word learning occurs only in clear teaching conditions — for example, when someone picks up an object, brings it to the baby, points to it and says its name. In fact, infants usually hear a new word for the first time under much more natural and complex circumstances such as the zoo example described.”What’s remarkable is that infants learned so much from hearing the conversation alone,” said Sandra Waxman, senior author of the study, the Louis W. …

Read more

Will your grandmother’s diet increase your risk of colon cancer?

Will a multi-generational exposure to a western type diet increase offspring’s chance of developing colon cancer? Will cancer-fighting agents, like green tea, help combat that increased risk?Those are the two questions Abby Benninghoff, an assistant professor in Utah State University’s College of Agriculture and Applied Sciences, will attempt to answer thanks to a $500,000 grant from the U.S. Department of Agriculture.”Simply put, if your grandmother ate a poor diet, will green tea be beneficial for you or not,” Benninghoff said.Benninghoff and her two collaborators, Korry Hintze and Robert Ward, both associate professors of nutrition, dietetics and food sciences, have developed a diet that mimics typical U.S. nutrition for studies of human cancer using animal models. In this case, rodents with cancer will be studied, which will allow Benninghoff to look at the effects of the diet on multiple generations in a short period of time.Benninghoff, predicts that green tea will have a greater benefit to those mice that are exposed to the western diet than those on a healthy diet. She also believes that the more generations exposed to the western diet, the greater the risk of colon cancer in the offspring.”In the end, what we’re hoping is to be able to determine if there are certain populations that would benefit from a diet modification, an increase consumption of green tea,” Benninghoff said. She also hopes the consequences of this diet will be better understood for the benefit of future generations.Story Source:The above story is based on materials provided by Utah State University. Note: Materials may be edited for content and length.

Read more

As hubs for bees, pollinators, flowers may be crucial in disease transmission

Like a kindergarten or a busy airport where cold viruses and other germs circulate freely, flowers are common gathering places where pollinators such as bees and butterflies can pick up fungal, bacterial or viral infections that might be as benign as the sniffles or as debilitating as influenza.But “almost nothing is known regarding how pathogens of pollinators are transmitted at flowers,” postdoctoral researcher Scott McArt and Professor Lynn Adler at the University of Massachusetts Amherst write. “As major hubs of plant-animal interactions throughout the world, flowers are ideal venues for the transmission of microbes among plants and animals.”In a recent review in Ecology Letters with colleagues at Yale and the University of Texas at Austin, McArt and Adler survey the literature and identify promising areas for future research on how floral traits influence pathogen transmission.As the authors point out, “Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research.” They say their synthesis could help efforts to control economically devastating pollinator-vectored plant pathogens such as fire blight, which affects rose family fruits such as apples and pears, and mummyberry disease, which attacks blueberries.McArt adds, “Our intent with this paper is to stimulate interest in the fascinating yet poorly understood microbial world of flowers. We found several generalities in how plant pathogens are transmitted at flowers, yet the major take-home from our paper may be in pointing out that this is an important gap in our knowledge.”The authors identified 187 studies pertaining to plant pathogens published between 1947 and 2013 in which floral visitors were implicated in transmission and where transmission must have occurred at flowers or pathogen-induced pseudoflowers. These are flower-like structures made by a pathogen that can look and smell like a real flower, for example. Regarding animal pathogens, they identified 618 studies published before September 2013 using the same criteria.”In total, we found eight major groups of animal pathogens that are potentially transmitted at flowers, including a trypanosomatid, fungi, bacteria and RNA viruses,” they note. Their paper, “Arranging the bouquet of disease: Floral traits and the transmission of plant and animal pathogens,” was featured in the publisher’s “News Round-Up” of “most newsworthy research.”Traditionally, research on flower evolution has focused largely on selection by pollinators, but as McArt and colleagues point out, pollinators that also transmit pathogens may reduce the benefits to the plant of attracting them, depending on the costs and benefits of pollination. The researchers say more work is needed before scientists can know whether a flower’s chemical or physical traits determine the likelihood that pathogens are transmitted, for example, and whether infection by pathogens is an inevitable consequence of pollinator visitation.”Plant pathologists have made great strides in identifying floral traits that mediate host plant resistance to floral pathogens in individual systems; synthesizing this literature can provide generality in identifying traits that mediate plant-pathogen dynamics. From the pollinator’s perspective, there has been surprisingly little work elucidating the role of flowers and floral traits for pathogen transmission. Given recent concerns about pollinator declines caused in part by pathogens, understanding the role of floral traits in disease transmission is a key missing element,” say McArt and colleagues.Story Source:The above story is based on materials provided by University of Massachusetts at Amherst. Note: Materials may be edited for content and length.

Read more

Wings, tails, fins: Study looks at how animals propel themselves

The wonder of animal movement — from the tiniest of insects to the largest fish in the sea — has been a subject of mystery for ages. But when it comes to animal propulsion, there are almost infinite kinds, but also limits that can’t be pushed or breakdowns will occur, according to an unusual study from a team that includes a Texas A&M University at Galveston researcher.Nathan Johnson, a graduate student at Texas A&M-Galveston who also teaches in the marine biology department, and colleagues from Harvard, California Institute of Technology, Indiana University and the Woods Hole Oceanographic Institute have studied the complex ways animal movements have evolved over millions of years and through hundreds of species. Their findings have been published in the current issue of Nature Communications.The team narrowed animal subjects down to 59 species for the study, and concentrated on ways each one is able to propel itself — through air, land or water.The key word appears to be “bend.” One common trait they found was each creature being able to “bend” its means of propulsion, but only to a certain point.”If you take the wing of a bird or a bat, or the fins on a fish or a manta ray, you find that their means of propulsion are flexible,” Johnson explains. “They can move back or forth or sideways easily, or they bend. But this bending and flexibility will only go so far, and it can’t bend any more.”For example, the fixed wing on an airplane is not flexible, while nature has had millions of years to figure out the best way to do it better than we can. So we wanted to see if there any patterns to this flexibility.”For most creatures, there is a certain angle that these propulsion devices will reach and won’t exceed. It’s not that they probably can’t exceed these angles, but rather doing so is just not energetically efficient for them.”There does seem to be a universal range of movement in the species we looked at, from the fruit fly to the humpback whale.”The team found that a 30 to 60-degree angle seems to be the magic range of how far animal propulsion can bend. “This appears to be especially true with bird wings, while insect wings typically bend slightly less than other organisms we looked at,” Johnson adds.Also, the researchers agreed that environmental factors could be a factor in the range of movement. And some species move almost identically to vastly different species; they found that much of the motion made by marine life is almost identical to that of birds — that is, the fin of a fish moves just like the wing of a bird.”We need to understand a lot of these motion patterns in much more detail,” Johnson says.”There are some current day tests being done with man-made materials to see if they can duplicate animal motion, such as some being done with jellyfish. The more we learn about animal propulsion and the way it’s been developed over millions of years of evolution, the more it can help us with human engineering and how we can improve our own movement.”The project was funded by the National Science Foundation.Story Source:The above story is based on materials provided by Texas A&M University. …

Read more

Cities support more native biodiversity than previously thought

The rapid conversion of natural lands to cement-dominated urban centers is causing great losses in biodiversity. Yet, according to a new study involving 147 cities worldwide, surprisingly high numbers of plant and animal species persist and even flourish in urban environments — to the tune of hundreds of bird species and thousands of plant species in a single city.Contrary to conventional wisdom that cities are a wasteland for biodiversity, the study found that while a few species — such as pigeons and annual meadow grass — are shared across cities, overall the mix of species in cities reflects the unique biotic heritage of their geographic location. The findings of the study conducted by a working group at UC Santa Barbara’s National Center for Ecological Analysis and Synthesis (NCEAS) and funded by the National Science Foundation were published today in the Proceedings B, a journal of the Royal Society of Biological Sciences.”While urbanization has caused cities to lose large numbers of plants and animals, the good news is that cities still retain endemic native species, which opens the door for new policies on regional and global biodiversity conservation,” said lead author and NCEAS working group member Myla F. J. Aronson, a research scientist in the Department of Ecology, Evolution and Natural Resources at Rutgers, The State University of New Jersey.The study highlights the value of green space in cities, which have become important refuges for native species and migrating wildlife. This phenomenon has been named the Central Park Effect because of the surprisingly large number of species found in New York’s Central Park, a relatively small island of green within a metropolis.Unlike previous urban biodiversity research, this study looks beyond the local impacts of urbanization and considers overall impacts on global biodiversity. The research team created the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities).Findings show that many plant and animal species, including threatened and endangered species, can flourish in cities, even as others decline or disappear entirely. Cities with more natural habitats support more bird and plant species and experience less loss in species as the city grows. Overall, cities supported far fewer species (about 92 percent less for birds and 75 percent less for native plants) than expected for similar areas of undeveloped land.”We do pay a steep price in biodiversity as urbanization expands,” said coauthor Frank La Sorte, a research associate at the Cornell Lab of Ornithology. “But even though areas that have been urbanized have far fewer species, we found that those areas retain a unique regional flavor. …

Read more

Giant mass extinction quicker than previously thought: End-Permian extinction happened in 60,000 years

The largest mass extinction in the history of animal life occurred some 252 million years ago, wiping out more than 96 percent of marine species and 70 percent of life on land — including the largest insects known to have inhabited Earth. Multiple theories have aimed to explain the cause of what’s now known as the end-Permian extinction, including an asteroid impact, massive volcanic eruptions, or a cataclysmic cascade of environmental events. But pinpointing the cause of the extinction requires better measurements of how long the extinction period lasted.Now researchers at MIT have determined that the end-Permian extinction occurred over 60,000 years, give or take 48,000 years — practically instantaneous, from a geologic perspective. The new timescale is based on more precise dating techniques, and indicates that the most severe extinction in history may have happened more than 10 times faster than scientists had previously thought.”We’ve got the extinction nailed in absolute time and duration,” says Sam Bowring, the Robert R. Shrock Professor of Earth and Planetary Sciences at MIT. “How do you kill 96 percent of everything that lived in the oceans in tens of thousands of years? It could be that an exceptional extinction requires an exceptional explanation.”In addition to establishing the extinction’s duration, Bowring, graduate student Seth Burgess, and a colleague from the Nanjing Institute of Geology and Paleontology also found that, 10,000 years before the die-off, the oceans experienced a pulse of light carbon, which likely reflects a massive addition of carbon dioxide to the atmosphere. This dramatic change may have led to widespread ocean acidification and increased sea temperatures by 10 degrees Celsius or more, killing the majority of sea life.But what originally triggered the spike in carbon dioxide? The leading theory among geologists and paleontologists has to do with widespread, long-lasting volcanic eruptions from the Siberian Traps, a region of Russia whose steplike hills are a result of repeated eruptions of magma. To determine whether eruptions from the Siberian Traps triggered a massive increase in oceanic carbon dioxide, Burgess and Bowring are using similar dating techniques to establish a timescale for the Permian period’s volcanic eruptions that are estimated to have covered over five million cubic kilometers.”It is clear that whatever triggered extinction must have acted very quickly,” says Burgess, the lead author of a paper that reports the results in this week’s Proceedings of the National Academy of Sciences, “fast enough to destabilize the biosphere before the majority of plant and animal life had time to adapt in an effort to survive.”Pinning dates on an extinctionIn 2006, Bowring and his students made a trip to Meishan, China, a region whose rock formations bear evidence of the end-Permian extinction; geochronologists and paleontologists have flocked to the area to look for clues in its layers of sedimentary rock. …

Read more

Do you have a sweet tooth? Honeybees have a sweet claw

New research on the ability of honeybees to taste with claws on their forelegs reveals details on how this information is processed, according to a study published in the open-access journal, Frontiers in Behavioral Neuroscience.Insects taste through sensilla, hair-like structures on the body that contain receptor nerve cells, each of which is sensitive to a particular substance. In many insects, for example the honeybee, sensilla are found on the mouthparts, antenna and the tarsi — the end part of the legs. Honeybees weigh information from both front tarsi to decide whether to feed, finds the latest study led by Dr. Gabriela de Brito Sanchez, researcher, University of Toulouse, and Dr. Martin Giurfa, Director of the Research Centre on Animal Cognition, University of Toulouse, France.Hundreds of honeybees were included in the study. Sugary, bitter and salty solutions were applied to the tarsi of the forelegs to test if this stimulated the bees to extend or retract their tongue — reflex actions that indicate whether or not they like the taste and are preparing to drink. Results revealed that honeybee tarsi are highly sensitive to sugar: even dilute sucrose solutions prompted the bees to extend their tongue. Measurements of nerve cell activity showed that the part of the honeybee tarsus most sensitive to sugary tastes is the double claw at its end. Also, the segments of the tarsus before the claws, known as the tarsomeres, were found to be highly sensitive to saline solutions.”Honeybees rely on their color vision, memory, and sense of smell and taste to find nectar and pollen in the ever-changing environment around the colony,” says Dr. Giurfa. …

Read more

Horse gaits controlled by genetic mutation spread by humans

From the Faroe Pony to the Spanish Mustang, fewer animals have played such a central role in human history as the horse. New research in Animal Genetics reveals that a horse’s gait, an attribute central to its importance to humans, is influenced by a genetic mutation, spread by humans across the world.The team, led by Dr. Leif Andersson from the Swedish University of Agricultural Sciences, explored the distribution of a mutation in the DMRT3 gene which affects the gait of horses, known as the ‘gait keeper.'”All over the world, horses have been used for everyday transportation, in military settings, cattle herding and agricultural power, pulling carriages and carts, pleasure riding or racing,” said Dr. Andersson. “Over the centuries, horse populations and breeds have been shaped by humans based on the different purposes for which the animals were used.”The DMRT3 gene is central to the utility of horses to humans, as it controls a range of gaits as well as pace. From racing to pleasure riding, many species have been bred to encourage smoothness of gait.”For example, the Paso Fino is a breed from Latin America in which the frequency of the ‘gait keeper’ mutation is nearly 100%. It is claimed that the Paso Fino gait is so smooth that you can have a glass of wine in your hand without letting it spill,” said Dr. Andersson.The team analyzed 4,396 horses from 141 breeds around the world and found that the ‘gait keeper’ mutation is spread across Eurasia from Japan in the East, to the British Isles in West, on Iceland, in both South and North America, and also in breeds from South Africa.”Humans have spread this mutation across the world primarily because horses carrying this mutation are able to provide a very smooth ride, in some breeds referred to as a running walk,” said Dr. Andersson. “During such ambling gaits the horse has at least one foot on the ground that means that the vertical movement of the rider is minimal.”Story Source:The above story is based on materials provided by Wiley. …

Read more

Teaching young wolves new tricks: Wolves are considerably better imitators than dogs

Although wolves and dogs are closely related, they show some striking differences. Scientists from the Messerli Research Institute at the University of Veterinary Medicine, Vienna have undertaken experiments that suggest that wolves observe one another more closely than dogs and so are better at learning from one another. The scientists believe that cooperation among wolves is the basis of the understanding between dogs and humans. Their findings have been published in the online journal PLOS ONE.Wolves were domesticated more than 15,000 years ago and it is widely assumed that the ability of domestic dogs to form close relationships with humans stems from changes during the domestication process. But the effects of domestication on the interactions between the animals have not received much attention. The point has been addressed by Friederike Range and Zsfia Virnyi, two members of the University of Veterinary Medicine, Vienna (Vetmeduni Vienna) who work at the Wolf Science Center (WSC) in Ernstbrunn, Niedersterreich.Wolves copy other wolves solving problemsThe scientists found that wolves are considerably better than dogs at opening a container, providing they have previously watched another animal do so. Their study involved 14 wolves and 15 mongrel dogs, all about six months old, hand-reared and kept in packs. Each animal was allowed to observe one of two situations in which a trained dog opened a wooden box, either with its mouth or with its paw, to gain access to a food reward. Surprisingly, all of the wolves managed to open the box after watching a dog solve the puzzle, while only four of the dogs managed to do so. Wolves more frequently opened the box using the method they had observed, whereas the dogs appeared to choose randomly whether to use their mouth or their paw.Watch closely …To exclude the possibility that six-month old dogs fail the experiment because of a delayed physical or cognitive development, the researchers repeated the test after nine months. …

Read more

Secret of cattle ticks’ resistance to pesticide

Oct. 7, 2013 — Scientists have discovered how a tick which transmits devastating diseases to cattle has developed resistance to one of the main pesticides used to kill it.Approximately 80% of cattle around the world, mostly in the tropics and sub-tropics, are exposed to the cattle tick — Rhipicephalis microplus — which can cause anemia, reduced rate of growth and death, resulting in a major economic impact on farmers.Prevention of disease is through frequent treatment of cattle with acarides -pesticides for ticks and mites — mainly amitraz, ivermectins and pyrethroids, but ticks have become increasingly resistant to these treatments.The global cost of the tick-borne diseases and associated acaricide application is estimated to be more than £4 billion annually.Now scientists at the University of Glasgow have identified the genetic basis for at least one form of resistance to amitraz which will allow a genetic test for resistance to be developed.Professor Nicholas Jonsson, of the Institute of Biodiversity, Animal Health and Comparative Medicine, said: “Resistance to all the main acaricides is well documented — for example amitraz resistance is seen in about 20% of Australian tick populations and more than 50% of Mexican ticks.”When resistance is found, farmers generally increase the frequency of acaricide treatment, resulting in increased cost and sometimes undesirable effects on the environment.”The most common response to the diagnosis of acaricide resistance on a farm is to change acaricide classes, but one of the problems faced by farmers is getting a reliable diagnostic test for resistance.”Although a genetic test for resistance is not likely to be perfect, the existing bioassays are technically challenging, expensive and require six weeks to complete.”This research paves the way for a new genetic test for resistance that will help farmers to make management decisions for the control of ticks as well as enable empirical studies on field and laboratory populations of ticks to test the effectiveness of resistance management strategies.The study was conducted on cattle at the University of Queensland’s Pinjarra Hills Campus, in Australia where the impact of ticks and treatments to control them costs £120 million per annum.Prof Jonsson added: “There are many theories as to how acaricide resistance can be delayed or accelerated in practice.”It has been suggested that rotating between acaricide classes, using mixtures of acaricides, preserving refugia of untreated populations, and using tick-resistant cattle might all delay the development of resistance.”However, without empirical studies to test the value of the management strategies, it is really impossible to provide evidence-based recommendations to farmers.”The research, published in the journal Proceedings of the National Academy of Sciences (PNAS), is the culmination of 10 years’ of research.

Read more

Dogs’ behavior could help design social robots

Sep. 12, 2013 — Designers of social robots, take note. Bring your dog to the lab next time you test a prototype, and watch how your pet interacts with it. You might just learn a thing or two that could help you fine-tune future designs. So says Gabriella Lakatos of the Hungarian Academy of Science and Eötvös Loránd University, lead author of a study¹ published in Springer’s journal Animal Cognition that found that man’s best friend reacts sociably to robots that behave socially towards them, even if the devices look nothing like a human.This animal behavior study tested the reaction of 41 dogs. They were divided into two groups depending on the nature of human-robot interaction: ‘asocial’ or ‘social.’One set of dogs in the ‘asocial group’ first observed an interaction between two humans (the owner and the human experimenter) and then observed an ‘asocial’ interaction between the owner and the robot. The remaining dogs in this group participated in these interactions in the reverse order.Then, in the ‘social group,’ one set of dogs watched an interaction between the owner and the human experimenter followed by observing a ‘social’ interaction between the owner and the robot. The remaining dogs in this group also participated in these interactions in the reverse order. These interactions were followed by sessions in which either the human experimenter or the robot pointed out the location of hidden food in both the ‘asocial’ and the ‘social’ groups.A customized human-sized PeopleBot² with two arms and four-fingered hands were used. One of its robotic arms makes simple gestures and grasps objects. …

Read more

Functioning ‘mechanical gears’ seen in nature for first time

Sep. 12, 2013 — Previously believed to be only human-made, a natural example of a functioning gear mechanism has been discovered in a common insect — showing that evolution developed interlocking cogs long before we did.The juvenile Issus – a plant-hopping insect found in gardens across Europe — has hind-leg joints with curved cog-like strips of opposing ‘teeth’ that intermesh, rotating like mechanical gears to synchronise the animal’s legs when it launches into a jump.The finding demonstrates that gear mechanisms previously thought to be solely human-made have an evolutionary precedent. Scientists say this is the “first observation of mechanical gearing in a biological structure.”Through a combination of anatomical analysis and high-speed video capture of normal Issus movements, scientists from the University of Cambridge have been able to reveal these functioning natural gears for the first time. The findings are reported in the latest issue of the journal Science.The gears in the Issus hind-leg bear remarkable engineering resemblance to those found on every bicycle and inside every car gear-box. Each gear tooth has a rounded corner at the point it connects to the gear strip; a feature identical to human-made gears such as bike gears — essentially a shock-absorbing mechanism to stop teeth from shearing off.The gear teeth on the opposing hind-legs lock together like those in a car gear-box, ensuring almost complete synchronicity in leg movement — the legs always move within 30 ‘microseconds’ of each other, with one microsecond equal to a millionth of a second.This is critical for the powerful jumps that are this insect’s primary mode of transport, as even miniscule discrepancies in synchronisation between the velocities of its legs at the point of propulsion would result in “yaw rotation” — causing the Issus to spin hopelessly out of control.”This precise synchronisation would be impossible to achieve through a nervous system, as neural impulses would take far too long for the extraordinarily tight coordination required,” said lead author Professor Malcolm Burrows, from Cambridge’s Department of Zoology.”By developing mechanical gears, the Issus can just send nerve signals to its muscles to produce roughly the same amount of force — then if one leg starts to propel the jump the gears will interlock, creating absolute synchronicity.”In Issus, the skeleton is used to solve a complex problem that the brain and nervous system can’t,” said Burrows. “This emphasises the importance of considering the properties of the skeleton in how movement is produced.””We usually think of gears as something that we see in human designed machinery, but we’ve found that that is only because we didn’t look hard enough,” added co-author Gregory Sutton, now at the University of Bristol.”These gears are not designed; they are evolved — representing high speed and precision machinery evolved for synchronisation in the animal world.”Interestingly, the mechanistic gears are only found in the insect’s juvenile — or ‘nymph’ — stages, and are lost in the final transition to adulthood. These transitions, called ‘molts’, are when animals cast off rigid skin at key points in their development in order to grow.It’s not yet known why the Issus loses its hind-leg gears on reaching adulthood. The scientists point out that a problem with any gear system is that if one tooth on the gear breaks, the effectiveness of the whole mechanism is damaged. While gear-teeth breakage in nymphs could be repaired in the next molt, any damage in adulthood remains permanent.It may also be down to the larger size of adults and consequently their ‘trochantera’ — the insect equivalent of the femur or thigh bones. The bigger adult trochantera might allow them to can create enough friction to power the enormous leaps from leaf to leaf without the need for intermeshing gear teeth to drive it, say the scientists.Each gear strip in the juvenile Issus was around 400 micrometres long and had between 10 to 12 teeth, with both sides of the gear in each leg containing the same number — giving a gearing ratio of 1:1.Unlike human-made gears, each gear tooth is asymmetrical and curved towards the point where the cogs interlock — as human-made gears need a symmetric shape to work in both rotational directions, whereas the Issus gears are only powering one way to launch the animal forward.While there are examples of apparently ornamental cogs in the animal kingdom — such as on the shell of the cog wheel turtle or the back of the wheel bug — gears with a functional role either remain elusive or have been rendered defunct by evolution.The Issus is the first example of a natural cog mechanism with an observable function, say the scientists.

Read more

Toward making people invisible to mosquitoes

Sep. 9, 2013 — In an advance toward providing mosquito-plagued people, pets and livestock with an invisibility cloak against these blood-sucking insects, scientists today described discovery of substances that occur naturally on human skin and block mosquitoes’ ability to smell and target their victims.Ulrich Bernier, Ph.D., who gave the talk, cited the pressing need for better ways to combat mosquitoes. Far from being just a nuisance, mosquitoes are more deadly to humans than any other animal. Their bites transmit malaria and other diseases that kill an estimated one million people around the world each year. In the United States, mosquitoes spread rare types of encephalitis, an inflammation of the brain. They also transmit heart worms to pet dogs and cats.”Repellents have been the mainstay for preventing mosquito bites,” said Bernier. “The most widely used repellant, DEET, is quite effective and has been in use for a long time. However, some people don’t like the feel or the smell of DEET. We are exploring a different approach, with substances that impair the mosquito’s sense of smell. If a mosquito can’t sense that dinner is ready, there will be no buzzing, no landing and no bite.”Female mosquitoes, which suck blood to obtain a protein needed to produce fertile eggs, can smell people from over 100 feet away. …

Read more

First animal model of adult-onset SMA sheds light on disease progression & treatment

Sep. 9, 2013 — A research team at Cold Spring Harbor Laboratory (CSHL) has used a recently developed technology they call TSUNAMI to create the first animal model of the adult-onset version of spinal muscular atrophy (SMA), a devastating motor-neuron illness.The same team, led by CSHL Professor Adrian R. Krainer, Ph.D., and including scientists from California-based Isis Pharmaceuticals, as well as the University of Southern California and Stony Brook University, succeeded a year ago in using TSUNAMI to make a mouse model of the disease as it is manifest in children. In its most severe form, called Type I SMA, the disease is the leading genetic cause of childhood mortality. Half of infants with Type I SMA die before their second birthday.Many SMA patients do reach adulthood, however, and on occasion people develop symptoms of the illness only after they have become adults. Hence the importance of the team’s success, reported online today in EMBO Molecular Medicine.All patients with SMA, regardless of their age, have a non-functional version of a gene called SMN1, or are missing it entirely. The acronym “SMN” stands for “survival of motor neuron” and suggests why SMA is so serious. The SMN1 gene encodes a protein, called SMN, that motor neurons need in order to function. Humans have a backup copy of the gene, called SMN2, which produces the same protein, but in much lower amounts.The body’s manufacture of the SMN protein from the SMN2 genecan limit the impact of SMA. How much a patient is helped depends on the number of copies of the SMN2 gene they possess. …

Read more

New insight into how Cheetahs catch their prey

Sep. 5, 2013 — A new research study has revealed that the cheetah, the world’s fastest land animal, matches and may even anticipate the escape tactics of different prey when hunting, rather than just relying on its speed and agility as previously thought.The study, which has just been published in the Royal Society Journal Biology Letters was carried out by a team of researchers from Queen’s University Belfast, in collaboration with other Institutions in the UK (University of Aberdeen, University of Swansea, Institute of Zoology, Zoological Society of London, University of Oxford), and elsewhere (North Carolina State University, The Lewis Foundation, South African National Parks, Earth and OCEAN Technologies, Kiel, Germany).The research team used GPS and accelerometer data loggers deployed on cheetahs, along with traditional observation methods. The study was funded by a Royal Society International Joint Project grant, a NERC New Investigator award and the Lewis Foundation.Explaining the team’s findings, lead researcher Dr Michael Scantlebury, from the School of Biological Sciences at Queen’s University Belfast, said: “The more we understand, about the physiology and the hunting tactics of this charismatic animal, the more we are able to ensure its continuing existence.””Our study found that whilst cheetahs are capable of running at exceptionally high speeds, the common adage that they simply ‘outrun’ their prey does not explain how they are able to capture more agile animals. Previous research has highlighted their incredible speed and acceleration and their ability to turn after escaping prey. We have now shown that hunt tactics are prey-specific.”In other words, we now know that rather than a simple maximum speed chase, cheetahs first accelerate towards their quarry before slowing down to mirror prey-specific escaping tactics. We suggest that cheetahs modulate their hunting speed to enable rapid turns, in a predator-prey arms race, where pace is pitted against agility. Basically, cheetahs have clear different chase strategies depending on prey species.”The research suggests that cheetah chases comprise two primary phases, the first an initial rapid acceleration resulting in high speed to quickly catch up with prey, followed by a second, which is a prey-specific slowing period, five to eight seconds before the end of the chase, that enables the cheetah to match turns instigated by prey as the distance between them closes.Dr Scantlebury added: “We have discovered that cheetahs first accelerate rapidly to get them close to the prey but then have to actively slow down to be able to match prey escape manoeuvres. It is like a deadly tango between the hunter and the hunted, with one mirroring the escape tactics of the other.””The time spent in the initial and second phase differs according to prey species, with some species such as ostriches, hares and steenbok attempting to escape by executing sudden changes in direction, whilst other species such as wildebeest, gemsbok and springbok attempt to run fast in a more or less straight line. It almost seems as if the amount of power or effort put into a chase is decided at the beginning of the chase depending on the prey species.”Dr Gus Mills, from the Lewis Foundation, South Africa and Oxford University’s WildCRU said: “Modern technology has given us the opportunity to record and measure facets of animal behaviour we have never been able to do. However, too often this is used without the essential backup of simultaneously observing the animals in the wild to validate what is being measured. …

Read more

Personality interactions between animals may dictate outcomes in the wild

Sep. 4, 2013 — Examining the varying personality types of multiple animal species at once — in addition to common single-species studies — could help biologists better predict ecological outcomes, according to a recent University of Pittsburgh study.By observing the interplay in a common predator-prey system (the jumping spider and the house cricket), a team of Pitt biologists found that it was the interactions between the personality types of two species that best predicted survival outcomes — and not the personality types of either species alone. Their findings were highlighted in the September print issue of Behavioral Ecology.”If we’re interested in really understanding how individual personalities influence ecology, then we also have to acknowledge and accept that the personalities of many species or groups are also important,” said Jonathan Pruitt, assistant professor of behavioral ecology in the Department of Biological Sciences within the Kenneth P. Dietrich School of Arts and Sciences.The team began by tracking both species’ activity levels to determine “personality” or behavior types. They started with the predator, collecting a population of spiders from Pitt’s Pymatuning Laboratory of Ecology. The researchers charted individual spiders’ activity within a five-minute span, seeing how far they could climb to the top of a vile. Their activity levels were measured, and the tests were repeated over four weeks to ensure that individuals’ behavior was repeatable. The team found that some individuals were consistently highly active, whereas other individuals of the same species were more sedentary.The crickets, which were collected commercially, had a bit of a different test, given their prey status. With room to move in an open field, the Pitt biologists monitored the crickets’ reaction times to a new place and their distance covered within five minutes. To ensure repeatability, this test was repeated over 10 days, once every other day. …

Read more

Administering natural substance spermidin stopped dementia in fruit flies

Sep. 1, 2013 — Age-induced memory impairment can be suppressed by administration of the natural substance spermidin. This was found in a recent study conducted by Prof. Dr. Stephan Sigrist from Freie Universität Berlin and the Neurocure Cluster of Excellence and Prof. Dr. Frank Madeo from Karl-Franzens-Universität Graz. Both biologists, they were able to show that the endogenous substance spermidine triggers a cellular cleansing process, which is followed by an improvement in the memory performance of older fruit flies.Share This:At the molecular level, memory processes in animal organisms such as fruit flies and mice are similar to those in humans. The work by Sigrist and Madeo has potential for developing substances for treating age-related memory impairment. The study was first published in the online version of Nature Neuroscience.Aggregated proteins are potential candidates for causing age-related dementia. …

Read more

Utilizzando il sito, accetti l'utilizzo dei cookie da parte nostra. maggiori informazioni

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close