434 news posts in Life sciences

Life sciences

28 Apr 2023

Old dogs with dementia sleep less deeply, just like people with Alzheimer’s

By Mischa Dijkstra, Frontiers science writer Scientists have shown that old dogs with canine dementia have sleep and brain wave patterns that mirror those found in people with Alzheimer’s. This is the first study to use polysomnography techniques from human sleep studies in old dogs In people with Alzheimer’s, the earliest symptoms are commonly disruptions in sleep rhythms. These include daytime sleepiness, showing agitation or confusion around dusk, staying awake longer, and waking up often at night. They are thought to result from damage to sleep-regulating areas in the brain. Alzheimer patients tend to spend less time in both REM (rapid eye movement) sleep, in which most dreaming occurs, and non-REM (NREM) sleep. But they show the greatest reduction in so-called slow-wave sleep (SWS) – a stage of non-dreaming deep sleep, characterized by slow ‘delta’ brain waves (0.1 to 3.5 Hz) – when day-time memories are consolidated. Now, scientists have shown that the same reduction in SWS and delta brain waves occurs in dogs with the canine equivalent of dementia, canine cognitive dysfunction syndrome (CCDS). These dogs thus sleep less and less deeply. The results are published in Frontiers in Veterinary Science. “Our study is the first to evaluate the […]

Life sciences

18 Apr 2023

Orb weaver spider glue properties evolve faster than their glue genes, scientists find

by Angharad Brewer Gillham, Frontiers science writer Image/Shutterstock.com Orb weaver spiders make the capture threads of their webs sticky with an aqueous glue made in special aggregate glands. Scientists studied different species living in different environments to see how the glue changed and found that although the glue was mostly made of the same components, the proportions of the proteins involved were different, changing the glue’s properties. Spiders that don’t weave good silk don’t get to eat. The silk spiders produce which creates their webs is key to their survival – but spiders live in many different places which require webs fine-tuned for local success. Scientists studied the glue that makes orb weaver spiders’ webs sticky to understand how its material properties vary in different conditions. “Discovering the sticky protein components of biological glues opens the doors to determining how material properties evolve,” said Dr Nadia Ayoub of Washington and Lee University, co-corresponding author of the study published in Frontiers in Ecology and Evolution. “Spider silk fibers and glues represent a fantastic model for answering such questions since they are primarily made of proteins and proteins are encoded by genes.” “Spider silks and glues have huge biomimetic potential,” added Dr […]

Life sciences

14 Apr 2023

‘Farmer’ beetle finds suitable host trees by tracing scent of its fungus crop

By Mischa Dijkstra, Frontiers science writer Alnus ambrosia beetles (Xylosandrus germanus) in their galleries, tending the brood and fungus. Image credit: Antonio Gugliuzzo Alnus ambrosia beetles (Xylosandrus germanus) are invasive, destructive pests of trees. For the first time, ecologists have identified volatile compounds released by the beetles’ own fungal symbiont as odors that attract females to existing colonies. These chemicals could be used to trap the beetles before they infest and kill new trees. The alnus ambrosia beetle Xylosandrus germanus, also known as the black stem borer, was accidentally introduced by humans from its native east Asia to North America and Europe around the beginning of the 20th century. X. germanus is a so-called ambrosia beetle, which means that it farms its own food: a specialized fungal symbiont which it ‘sows’ and tends inside the galleries that it digs inside wood. It is a destructive invasive pest, known to attack more than 200 species from 51 families of broadleaf and conifer trees. While it prefers to colonize dead wood, it can also infest and ultimately kill weakened or stressed trees. A proven way to monitor or even control insect pests is by hijacking their communication system and manipulating it to […]

Life sciences

13 Apr 2023

Coral-eating fish poo may act as ‘probiotics’ for reefs

by Angharad Brewer Gillham, Frontiers science writer Image/Shutterstock.com Coral-eating fish are thought to weaken coral reefs because they consume coral tissue, whereas grazer fish are assumed to have positive effects because they eat algae that compete with corals. However, a new study shows that feces from coral-eating fish contain bacteria that can be beneficial to corals. On the other hand, feces from grazers contain high levels of pathogens that can kill corals. Until recently, fish that eat coral — corallivores — were thought to weaken reef structures, while fish that consume algae and detritus — grazers — were thought to keep reefs healthy. But scientists have discovered that feces from grazers leave large lesions on coral, possibly because they contain coral pathogens. By contrast, feces from corallivores may provide a source of beneficial microbes that help coral thrive. “Corallivorous fish are generally regarded as harmful because they bite the corals,” said Dr Carsten Grupstra of Rice University, lead author of the study published in Frontiers in Marine Science. “But it turns out that this doesn’t tell the whole story. Corallivore feces contain many of the bacterial taxa that associate with healthy corals under normal conditions, potentially resulting in the natural […]

Life sciences

12 Apr 2023

Most plastic eaten by city vultures comes straight from food outlets

By Mischa Dijkstra, Frontiers science writer Black vultures, Coragyps atratus, in the US. Image credit: Hannah Partridge Researchers have shown that black and turkey vultures in US urban areas get most of the plastic they ingest from nearby food stores and restaurants. They often seem to eat plastic unintentionally, risking their health, but in some cases may do so on purpose to induce vomiting up of other undigested foods. Since the 1950s, humanity has produced an estimated 8.3bn tons of plastic, adding a further 380m tons to this amount each year. Only 9% of this gets recycled. The inevitable result is that plastic is everywhere, from the depths of the oceans to the summit of Everest – and notoriously, inside the tissues of humans and other organisms. The long-term effects of ingested plastic on people aren’t yet known. But in rodents, ingested microplastics can impair the function of the liver, intestines, and exocrine and reproductive organs. Especially at risk of ingesting plastic are scavenging birds. For example, New World vultures regularly forage at landfills, and have been observed to leisurely pick at synthetic materials such as boat seats, rubber seals, or roofs. Read original article Download original article (PDF) Now, […]

Life sciences

29 Mar 2023

Lizards at US Army installation are stress eating during flyovers

By Mischa Dijkstra, Frontiers science writer Colorado checkered whiptail, Aspidoscelis neotesselata. Image credit: Carina Kusaka Scientists studied the response of an uncommon asexual lizard, the Colorado checkered whiptail, to anthropogenic noise at the military installation Fort Carson. They compared the lizard’s behavior between dates with and without flyovers by military aircraft. On flyover dates, the lizards showed a physiological stress response and spent more time eating and less time moving. These results suggest that the lizards deal with noise pollution by eating more to maintain the energy levels. Lizards may be small, with only a single hearing bonelet compared to our three, and without earflaps, but their hearing is typically good. Most lizards can hear frequencies between 100 and 5,000 Hz (although they are most sensitive between 400 and 1,500 Hz), compared to between 20 and 20,000 Hz in humans. So how do lizards react to noise pollution? Here, scientists studied the impact of noise from low-flying military aircraft on the behavior and well-being of an uncommon lizard, the Colorado checkered whiptail (Aspidoscelis neotesselatus). This was done at the Fort Carson US military Installation near Colorado Springs, where Apache, Chinook, and Blackhawk helicopters regularly fly over, and occasionally transport aircraft […]

Life sciences

22 Mar 2023

Unusual Toxoplasma parasite strain killed sea otters and could threaten other marine life

by Angharad Brewer Gillham, Frontiers science writer Image by Mr Laird Henkel, California Department of Fish and Wildlife Four sea otters that stranded in California were found to have died of an unusually severe form of toxoplasmosis, a disease caused by the microscopic parasite Toxoplasma gondii. Scientists warn that this new strain, never previously reported in aquatic animals, could potentially pose a health threat to other marine wildlife and humans. Scientists in California are raising the alarm about a newly reported form of toxoplasmosis that kills sea otters and could also infect other animals and people. Although toxoplasmosis is common in sea otters and can sometimes be fatal, this unusual strain appears to be capable of rapidly killing healthy adult otters. This rare strain of Toxoplasma hasn’t been detected on the California coast before, and may be a recent arrival, but scientists are concerned that if it contaminates the marine food chain it could potentially pose a public health risk. “I have studied Toxoplasma infections in sea otters for 25 years — I have never seen such severe lesions or high parasite numbers,” said Dr Melissa Miller of the California Department of Fish and Wildlife, corresponding author of the study […]

Life sciences

16 Mar 2023

Common meat-free proteins may trigger soybean and peanut allergies in some people

by Angharad Brewer Gillham, Frontiers science writer Image/Shutterstock.com Meat-free proteins based on legumes are increasingly common. But so are allergies to soy and peanuts, which are also legumes. To find out if it’s safe for patients with these allergies to eat legume-based alternative proteins, scientists investigated how frequent cross-reactions are among people with different legume allergies. They found that although people often produce antibodies against multiple legumes, they rarely have a clinically relevant reaction. Soybean and peanut allergy patients are usually not allergic to other legumes. Many people keen to reduce their meat consumption are turning to substitutes made of legumes packed with protein, vitamins, and fiber. But allergies to legumes like soy or peanuts are both common and dangerous. Are patients allergic to particular legumes at risk from meat-free proteins made of legumes even if they contain different legumes? Dr Mark Smits and a team of scientists at University Medical Center Utrecht set out to investigate. “Both protein consumption and the world’s population are increasing which leads to an urgent demand for sustainable protein sources,” said Dr Thuy-My Le, senior author of the study published in Frontiers in Allergy. “An increase in the consumption of legumes may increase the […]

Life sciences

15 Mar 2023

Rapid surge in highly contagious killer fungus poses new threat to amphibians across Africa

By Mischa Dijkstra, Frontiers science writer Researchers studied the prevalence of the fungus Batrachochytrium dendrobatidis (Bd) in a total of 16,900 historical and recent museum specimens, wild-living individuals, and literature records of amphibians from Africa. Bd causes chytridiomycosis, a contagious and lethal disease of amphibians that has driven hundreds of species worldwide to extinction. Only amphibian species in Africa had so far escaped chytridiomycosis epizootics, but the present study shows that this reprieve is now likely over. Mass fungus infections that drive populations worldwide to near-collapse don’t just occur in science fiction. Chytridiomycosis, the worst vertebrate disease in recorded history, has already wiped out hundreds of species of amphibians around the world. Due to a large part to this fungal disease, 41% of amphibians are currently threatened with extinction. Only species living in Africa seemed to have been relatively spared from the scourge of chytridiomycosis – at least so far. Now, a study in Frontiers in Conservation Science has shown that this reprieve was likely temporary: the results show that the fungus Batrachochytrium dendrobatidis (Bd), the pathogen that causes chytridiomycosis, is by now firmly established throughout Africa. It may so far have been overlooked there, but it is likely that […]

Life sciences

06 Mar 2023

Bees follow linear landmarks to find their way home, just like the first pilots

By Mischa Dijkstra, Frontiers science writer Scientists have shown that honeybees retain a memory of the dominant linear landscape elements in their home area like channels, roads, and boundaries. When transported to an unfamiliar area, they seek out local elements of this kind, compare their layout to the memory, and fly along them to seek their way home. This navigation strategy is similar to the one followed by the first human pilots. In the earliest days of human flight, before the invention of the first radio beacons and ground-based electronic systems, and modern GPS, pilots commonly navigated by following roads and railways – striking linear landscape elements at ground level that guide towards a destination of interest. Enter the honeybee. A century of research has shown that honeybees are navigators par excellence. They can navigate by their sense of smell, the sun, the sky’s pattern of polarized light, vertical landmarks that stand out from the panorama, and possibly the Earth’s magnetic field. They are also clever learners, able to recognize associations between disparate memories in order to generalize rules. Now, scientists have shown that honeybees tend to search for their way home by orienting themselves in relation to the dominant […]

Life sciences

13 Feb 2023

European big cat population threatened with extinction as genetics show the population is near collapse

by Angharad Brewer Gillham, Frontiers science writer Image/Shutterstock.com Eurasian lynxes dispersed across the Swiss border with France in the late 1970s, but the population remains small and fragile. Scientists took genetic samples from lynxes in France and determined that the population’s genetic health is so dangerously tenuous it could be extinct in a generation. Scientists warn that if action isn’t taken soon, the Eurasian lynx will vanish from France. This elusive wild cat, which was reintroduced to Switzerland in the 1970s, moved across the French border by the end of the decade. But a genetic study published in Frontiers in Conservation Science showed that the lynx population in France is in desperate need of help to survive. “Given the rapid loss of genetic diversity, we estimate that this population will go extinct in less than 30 years,” said Nathan Huvier of the Centre Athenas, corresponding author. “This population urgently needs new genetic material to become sustainable.” The missing lynx This population of lynxes, hidden deep within the Jura Mountains, is not well known. Observations by scientists estimate its size at a maximum of 150 adults and suggest that it is poorly connected to larger, healthier populations in Germany and Switzerland, […]

Life sciences

06 Feb 2023

‘Many kids go through a phase where they want to be a marine scientist. For me, it wasn’t a phase’

by Patricia Albano/Angharad Brewer Gillham, Frontiers science writer Patricia stands with remotely operated vehicle Deep Discoverer aboard NOAA Ship Okeanos Explorer during an expedition to explore the deep waters off the West Florida Shelf. Image: Patricia Albano. Marine protected areas are meant to give threatened species space to live and thrive. But in a recent paper in Frontiers in Marine Science, Patricia Albano and colleagues showed that at least one protective area isn’t capturing the range that endangered sharks use as they grow, leaving them vulnerable to commercial fishing. Albano, now the Internship Program Coordinator at the National Marine Sanctuary Foundation, NOAA Ocean Exploration, caught up with Frontiers to tell us a little about her career and her research, as part of our Frontiers Scientist series. Albano’s work focuses on shark ecology in an anthropogenic world and the associated conservation implications. After a BA and MSc from the University of Miami, she joined a project evaluating the efficacy of the De Hoop marine protected area (MPA) for threatened and endemic sharks off South Africa. Albano also dedicates her time to working in ocean education, supporting workforce development programs and efforts to increase diversity, equity, inclusion, and accessibility. In 2020, she […]

Life sciences

01 Feb 2023

Medicines that modify the circadian clock might help heal scars more cleanly

by Angharad Brewer Gillham, Frontiers science writer Image/Shutterstock.com Scientists determined that compounds which play key roles in both collagen synthesis and circadian management can be used to make wounds on cell samples heal more quickly and effectively, offering promise for treatments to prevent problem scarring in the future. Healing often leaves a scar. But the role of the scar itself in healing is often underestimated: a scar that doesn’t heal cleanly can be painful or upsetting or affect the range of movement of the affected body part. It may even require further surgical treatment. Now, scientists based at the University of California Los Angeles have found that compounds which target the circadian clock and affect the synthesis of collagen — a protein which is important for skin repair — could improve scar healing. “Our aim was to find compounds that were able to increase the rate at which dermal wounds heal while mitigating the formation of hypertrophic scars,” said Dr Akishige Hokugo, corresponding author of a study published to Frontiers in Medicine. “Scars can result in emotional distress following normal wound healing by serving as permanent reminders of the initial incident. Accounting for additional revision procedures, extended hospital stays, and […]

Life sciences

31 Jan 2023

Songbird species work together to mob predator owls, but only strike when the time is right

By Mischa Dijkstra, Frontiers science writer Northern pygmy owl, Glaucidium gnoma. Image credit: W Douglas Robinson Scientists have now shown that songbirds don’t just flee from their predator, the northern pygmy owl: they sometimes actively seek them out to aggressively mob them. But the likelihood of mobbing wasn’t constant: it was highest during late summer and autumn when the owls mostly prey on young birds instead of mammals, and at low altitudes, where the owls are most common. The likelihood of mobbing also increased when there were more songbirds around to dilute the individual risk. The authors conclude that songbirds can tell when the risk of predation from northern pygmy owls is greatest, and mostly ignore these owls at other times of the year. Fleeing isn’t the only way by which songbirds can protect themselves against predators. Many songbird species are known to engage in mobbing, where they gather aggressively around a bird of prey, flying rapidly while making stereotypic movements and loud vocalizations. Mobbing is risky for both parties: birds of preys have been observed to attack their mobbers, while cases are known of birds of prey getting injured by mobbing songbirds. Read original article Download original article (pdf) […]

Life sciences

24 Jan 2023

‘Golden boy’ mummy was protected by 49 precious amulets, CT scans reveal

By Mischa Dijkstra, Frontiers science writer The ‘Golden boy’ digitally unwrapped, stepwise. Image credit: SN Saleem Scientists used CT scans to ‘digitally unwrap’ the approximately 2,300-year-old undisturbed mummy of a teenage boy of high socioeconomic status. The body was equipped with 49 amulets of 21 different types, many of which were made of gold, which had been carefully placed on or inside the body. These included a two-finger amulet next to the uncircumcised penis, a golden heart scarab placed inside the thoracic cavity, and a golden tongue inside the mouth. He was clad in sandals and garlanded with ferns, with ritual significance. This mummy is a showcase of Egyptian beliefs about death and the afterlife during the Ptolemaic period. The ancient Egyptians believed that when we died, our spiritual body sought out an afterlife similar to this world. But entry into this afterlife wasn’t guaranteed: it first required a perilous journey through the underworld, followed by an individual last judgment. For this reason, relatives and embalmers did everything they could to ensure that their loved one might reach a happy destination. Here, scientists from Egypt used computerized tomography (CT) to ‘digitally unwrap’ the intact, never-opened mummy of a 2,300-year-old teenage […]