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Prehistoric white sharks can help us save sharks in modern day

How researchers found a two to five million year old shark nursery

White sharks may have a guaranteed spot on Shark Week but there is still a lot to learn about this famed fish. 

Sharks have been around for millions of years. The earliest fossil of Carcharodons, the genus of the white shark, dates back to 16 million years ago. Yet today, white shark populations are considered vulnerable to becoming endangered due to overfishing.

Protecting these sharks can be tricky. There are white shark aggregation sites around the world, but each of these populations have different behaviors and migratory patterns. Scientists are studying each existing population to inform local policy and management. 

White shark hot spots

White shark hot spots

CC 4.0

It isn't just modern populations of sharks that can provide us with useful insight. Understanding how white sharks thrived millions of years ago could help us protect them today. 

Researchers have proposed a location in Coquimbo, Chile as a nursery for white sharks during the Pliocene Epoch, a period of geologic time that spans from 5.33 million to 2.58 million years ago. 

A nursery habitat is an area that contributes more juveniles of a species to the adult population compared to other areas. To be considered a nursery, the area in question had to fit three criteria: be a shallow water environment, have an abundance of resources, and be dominated by juveniles white sharks. 

Shark Tooth

Shark tooth

Eddie Fouse

The researchers collected white shark fossil teeth from three different places. They used measurements of the teeth to estimate the total length of the individual sharks. The total length of a juvenile white shark was considered to be between 175 cm to 300 cm. In Coquimbo, there was a higher proportion of juveniles compared to the other study sites. The researchers also found signs of potential prey species and evidence that this area was once a shallow-water marine habitat. 

Nursery habitats helped protect young sharks millions of years ago. Identify and conserving modern nursery habitats could be an important factor in keeping white shark populations stable today. 

DNA found in caterpillar guts points to what they are eating

This method is more precise than past approaches, where scientists assumed that insects primarily ate the plants they were found on

Fernanda Ruiz Fadel

Animal Behavior and Behavioral Genetics

Advanced Identification Methods GmbH

Host-plant interactions have long been a topic that intrigues scientists. However, for smaller species, like insects and their larvae, it has not always been possible to conclusively identify interactions. Just because you find a larva in a certain tree, doesn’t necessarily mean that tree is itself the larva's meal of choice. It could very well be eating lichens, mosses, fungi or other much smaller species associated with the larger plants. 

But now, thanks to advances in DNA sequencing and the vast DNA reference library datasets, scientists now can turn to genetics to confirm associations and make new insights into the world of insect-plant interactions.

That is what three research groups in Germany (Bavarian State Collection of Zoology, Advanced Identification Methods Gmbh and University of Würzburg) are piloting on a large sample of caterpillars from Peru. They sequenced a specific gene in each of 119 individual caterpillars that matched to 92 species in the database. DNA from the caterpillars' guts revealed that these caterpillars feed on many plant species, including lianas (a type of climbing vine) and mosses. Around 80% of them did not have the DNA of the trees where they were found in their gut content. 

Scientists are still trying to optimize the whole protocol, but this methodology shows a new way of looking into host-plant and food web interactions, and informing species diversity for conservation efforts. Now that they know this system works, their future plans include identifying much bigger datasets of arthropod groups and their hosts.

A "fight-or-flight" neurotransmitter may cause traumatic memories to stick around

Blocking noradrenaline in rats made their memories more susceptible to change

Mariella Bodemeier Loayza Careaga

Neuroscience

Uniformed Services University of the Health Sciences

New memories undergo a period of consolidation to become stable and long-lasting in our brains. However, when we recall a new memory, it becomes unstable and susceptible to change. To persist, a memory undergoes a process called reconsolidation thought to make it stable again.

Memories from stressful situations do not become unstable after recall, and changes during the consolidation of these memories may influence this resistance to instability and reconsolidation. The neurotransmitter noradrenaline could have a role in this, as it is released during the consolidation of emotional memories.  

Researchers from McGill University assessed if noradrenaline released into the amygdala, a brain region important for consolidation of emotional memories, was essential for the resistance to instability and reconsolidation after recall. To do this, they taught rats to associate a tone to a mild foot shock. To form “weak” or “strong” memories, animals were exposed to either 1 or 10 tone-shock presentations, respectively. Memory instability and reconsolidation were evaluated by treating animals with anisomycin, an antibiotic that interferes with memory reconsolidation by blocking protein production. Anisomycin blocks reconsolidation on animals that formed a “weak” memory but has no effect on animals that formed a “strong” memory. 

Max Levy

Animals that formed a “strong” memory have lower levels of proteins associated with neural plasticity changes, which are important to the brain to change and adapt, in the amygdala. Decreasing the noradrenergic signaling in the amygdala by either blocking its receptors or reducing noradrenaline release from the locus coeruleus (the major source of noradrenaline in the brain) before a “strong” memory is formed lead to memory susceptibility after recall. This susceptibility is related to neural plasticity changes in a “strong” memory that are similar to the ones observed in a “weak” memory.    

These findings may help to better understand why memories from highly stressful events, like traumatic situations, persist in the brain, and are resistant to manipulations after recall. This, in turn, may help developing new treatment strategies for people affected by stress-related disorders such as post-traumatic stress disorder.

Scientists found powerful antibodies that target human cytomegalovirus

The virus can lead to severe complications in children and organ transplant recipients

Georgina To'a Salazar

Chemical Engineering and Biomedical Engineering

University of Texas Health Science Center at Houston

Like SARS-CoV-2, human cytomegalovirus (HCMV) is a virus that causes only mild symptoms in most people it infects, but has the ability to cause severe problems in certain cases.

Most people around the world encounter HCMV as children. Infection is lifelong, and the virus usually remains latent. However, HCMV infection is a major cause of illness in organ transplant recipients, whose immune systems must be suppressed for transplants to be accepted. And children born with HCMV infection may also develop related congenital disorders, including childhood hearing loss and neurological problems. Development of new treatment strategies is still needed to address these severe complications.

Vaccines that stimulate an immune response against HCMV are one strategy to protect against infection by the virus. Antibodies manufactured in laboratories are part of another strategy to treat HCMV infection. But the development of these strategies depends on our ability to answer questions about how the virus infects cells and how the immune system responds.

In a paper published in PLOS Pathogens, Xiaohua Ye and colleagues clarified answers to some questions about HCMV infections. They isolated antibodies that are part of a human donor’s response to a natural HCMV infection. Among these antibodies, they found one that was especially powerful at neutralizing the virus.

Other antibodies targeting the same region of the virus as the powerful antibody they discovered have been associated with protective immunity against HCMV disease in transplant recipients and infants at risk for congenital HCMV infection — two populations most affected by severe consequences from HCMV. This work advances our understanding of how antibodies neutralize HCMV, which will be helpful for the development of vaccines and antibody drugs against HCMV infection. 

This extinct reptile was a righty, research shows

Like toads and cats, Captorhinus aguti seems to prefer its right side when munching

Mallory Wiper

Evolutionary Biology and Animal Behavior

Laterality — or hemispheric specializations within the brain, the thing that makes us right- or left-handed — was once thought to be a human-only trait. Research has found, however, that this trait is shown by many nonhuman species, too! A multitude of organisms demonstrate differential brain hemisphere control for behaviors like vocalization, escape reactions, and feeding.

Knowing that nonhuman animals exhibit laterality in their behavior raises several questions: how far back in history does laterality go? How many extinct organisms may have had lateral hemisphere control of their behaviors? And, is it even possible to figure out whether prehistoric animals did display laterality?

Much of the present research into lateralization in living organisms uses non-invasive observations of behavior. Since we can’t do that with extinct organisms, we have to turn to fossil records to see what clues we might find about their behavior. 

captorhinus drawing

An artist's rendition of Captorhinus aguti

Nobu Tamura, Wikimedia Commons

A recent study cleverly used the fossilized dental records of an extinct reptile, Captorhinus aguti, in an effort to determine if this reptilian ancestor showed a lateralized feeding preference. Investigations of 89 intact jaws of Captorhinus resulted in a clear pattern: there was much greater wear on the teeth of the right side of the jaw, suggesting a clear right side preference for feeding. That is, Captorhinus reptiles were ripping, tearing, and chewing food with and on the right side of the jaw significantly more often than with the left side of their jaw. This preference for right side control of feeding behavior has been maintained in present-day species like toads and domestic chickens

The Captorhinus fossil records demonstrate that this reptilian ancestor showed lateralized responses with the crucial-to-survival behavior of feeding. But this finding raises further questions. What other functionally relevant lateralized behaviors may have existed in the lives of extinct organisms, and what might such lateralized behaviors tell us about the evolution of hemispheric specializations of vertebrate species alive today?

Decades-old theory on how ears work is wrong

After 30 years, scientists still don't know how the ear tells the brain what it is hearing

Josseline Ramos-Figueroa

Chemistry

University of Saskatchewan

How do we hear? When noise is produced, sound waves travel through the air and reach our inner ear, causing a mechanical perturbation in specialized rod-shaped cells — known as hair cell bundles. These auditory receptor cells transform the mechanical force from the sound waves into an electrical signal sent to our brains, which then reads it as sound.

But how does this mechano-electric transduction work? Auditory scientists have long believed that this signal transduction occurs through two adaptation processes. One is the opening of pore-like channels on the surface of cells that allow ions to enter. The other process, a “motor model,” involves the movement of a fiber-like protein known as myosin. This protein connects the upper sides of each hair cell in the bundle, and upon a mechanical stimulus, it slides, slightly pulling the connected hair cells down. Or so it was thought.

Ear sensory cells

NIH

After more than 30 years of research, researchers at the University of Colorado Anschutz Medical Campus reported in Science that the motor model hypothesis was incorrect and, therefore, scientists still do not fully understand the underlying mechanisms by which our auditory cells work.

In brief, the team mechanically perturbated mammalian hair cell bundle samples, taking high-speed videos to test cell movement as hypothesized in the motor model. To resemble perturbations generated by sound, they splashed hair cells with a small stream of water or pushed them down using flexible glass fiber. Video analysis then showed that regardless of the stimulus used — water or glass fiber — the hair cells didn't move during the adaptation process, ruling out the decades-old motor model hypothesis.

Because the adaptation process is considered a critical factor in the high sensitivity and range of the mammalian auditory system, the authors foresee that their findings will lead to future technological improvements in sound processing and treatment of hearing loss.

Parasites in freshwater fish make them more hazardous than ocean fish

It may be wise to cancel your raw catfish sushi order

Kristen Vogt Veggeberg

Science Education

University of Illinois at Chicago

If you’ve ever eaten sushi, you’ve probably scrolled through a list of different raw fish on the menu, in addition to all the spider rolls and dragon rolls. Salmon, tuna, and shrimp are some of the most common, but what about other, commonly eaten fish, such as catfish or trout? Why don’t we see these in any Western sushi restaurants? 

The big difference is in where the fish were caught. The science behind freshwater or ocean fish consumption is fairly simple: freshwater fish, at least in the United States, tend to have more parasites. 

Scientists are calling for caution when selecting raw fish for consumption as our demand for it expands across the globe. In a review published earlier this year, researchers updated the current understanding of food safety hazards of raw fish. 

Microscopic creatures such as Diphyllobothriidae (a type of tapeworm) can cause horrible illness when consumed, leading to diarrhea and intestinal issues in humans. One of the best ways to get rid of these parasites is by cooking the fish, whether by frying or baking at a certain temperature. If you’ve ever caught food poisoning from seafood, you’ll know it is perhaps the most painful version of a stomach bug. There are exceptions to this need for ocean caught fish rule for raw consumption in other countries. Namely, that is the eel, which is smoked and then prepared with a sugar-based sauce. Other problematic fish, such as mackerel, are pickled.

How fish is prepared is another reason why sushi is often ocean fish. Most ocean caught fish are frozen immediately after catching and butchering. This kills most of their potential parasites. Once the fish is frozen, it can be safely transported to a wide variety of destinations, including places far from local coasts, and inspected for parasites. 

María Bräuner

Limnology

Universität für Bodenkultur Wien

On September 17th, the 30th Ceremony of the Ig Nobel Prize took place virtually. Although the ceremony might seem like a joke, it is actually a real prize ceremony with real scientists to recognize overlooked research that "makes you laugh, then think". But how do you deliver a prize virtually? 

The answer is that you make the winner build it! Unlike the Nobel Prize, which is honored with a medal, a diploma, and 9 million Swedish kronas (over $1 million USD), the Ig Nobel usually gives out a certificate, a crafty trophy, and a $10 trillion Zimbabwean bill. But in the virtual reality of 2020, the prizes were all self-assembled by the winners following the instructions sent out in a PDF.

This year's winners did research on a crocodile’s voice before and after inhaling helium, how people from countries with more income inequality kiss more often, "poop knives", and arachnophobic entomologists. A very well-deserved prize for Medical Education was also awarded to several political leaders for their mishandling of the COVID-19 pandemic.

If you think this is mocking the "real" Nobel prize, you'd be surprised to know that actual Nobel Laureates deliver the Ig-Nobel prizes to the winners. During the ceremony, former winners, Nobel laureates, and other invited scientists deliver 24/7 lectures. They have 24 seconds to explain their research, and then they explain it again in a way that anyone can understand in just 7 words. Dr. Elena Bodnar made an appearance again this year with the invention that made her win the Ig-Nobel back in 2009: a bra that turns into protective face masks.

I'd highly recommend watching the ceremony, which demonstrates just how ingenious, sometimes disgusting, and very funny scientists can be. 

The mysterious link between stress, gut inflammation, and Parkinson's disease

Parkinson's disease is related to neurons, but could it be driven by the gut?

Elena Dennis

Cognition and Neuroscience

University of Sussex

Parkinson’s Disease (PD) is characterized by resting tremor, slow movements, and rigid muscles. For decades we have known it involves dopamine-releasing neurons in the middle of the brain dying. However, in recent years scientists have suggested its origin could be in the gut rather than the brain.

For example, people with PD have been shown to experience symptoms in the gut, such as abnormal bacteria populations, and gut “leakiness”, which lets bacteria and toxins pass easily from the gut into the blood. Exactly how this relates to PD is a mystery.

In a paper published in Neurobiology of Disease in February, researchers used mice with PD-like features to investigate gut leakiness and fecal bacteria populations. Some of the mice were also chronically stressed, and the researchers compared their gut features to unstressed mice. The researchers examined their intestines under a microscope and measured their gut inflammation levels.

They found that the stressed mice had damaged, leaky intestines. Additionally, stress activated the microglia, small cells in the brain known for their role in inflammation and immunity. Chemical markers of inflammation were increased in these mice, and the types of bacteria found in their feces were also different than in unstressed mice: stress reduced the “anti-inflammatory” bacteria. Stressed mice with PD-like features had severe gut hyperpermeability.

This increase in gut inflammation could lead to increased inflammation in the brain too. These findings support the gut-brain axis hypothesis of PD, showing a role of chronic stress in driving this. Understanding what occurs in the gut, and what causes this gut disruption, would allow a whole new therapeutic strategy for treating PD.

New video of peccaries mobbing a jaguar shows predator-prey interactions go both ways

The peccaries prevented the jaguar from eating its meal

E. Melanie Watt

Zoology and Conservation Biology

A mother jaguar and her 8-month old male cub climb further up the tree, trying to avoid a swarming mob below. Unable to carry up the capybara she recently killed, the female jaguar drops it as the cats make their rapid upward escape, ultimately spending the next 10 hours up the tree.

The jaguars’ adversaries were not what you might think. They were white-lipped peccaries, pig-like animals that often serve as prey for the majestic spotted cats. These ungulates (hoofed animals) are found from Mexico to Argentina and often occur in groups of 150-200, while jaguars are usually solitary predators, except for mothers with cubs.

This amazing scenario is one of several similar events recently published in the journal Acta Ethologica which demonstrate the complexities of what were once thought to be simple predator/prey interactions. 

In this case, the researchers have video proof that the peccaries (prey) engage in mobbing behavior toward a predator. Mobbing is when individuals or a group of prey attack or harass a predator until the predator leaves the area or stops pursuing them. Anti-predator behaviors, including alarm calls and guarding young, as well as mobbing have previously been reported in primates, birds and ungulates. 

Although scientists had heard anecdotal reports of this behavior in the past, these researchers were able to catch the mobbing peccaries on video camera traps. In one video, a group of 15 peccaries were seen at the base of a tree with a jaguar in it, clacking their canines with their hackles raised. Later they chased the jaguar into the Brazilian forest. In other videos, the peccaries were not deterred even though the jaguar they were mobbing snarled, hissed and fake-charged them. 

Prey spend time and energy and put themselves at risk through anti-predation behaviors like mobbing, but they aren’t the only ones incurring a cost. This video showed direct evidence that the peccary prey actually disrupted the predator's ability to successfully catch or consume prey. Far from the simple “eat or be eaten,” scientists are continuing to discover more complexities of predator-prey interactions.

Sea bird poop is worth over $1 billion USD per year

The nutrients in guano fertilize both farm fields and ocean reefs

Ashley Marranzino

Marine Biology

University of Rhode Island

The thought of seabirds might evoke memories of a perfect beach day ruined by a flock of noisy gulls stealing your lunch and defecating on you or your belongings. While you were shooing away the unwelcome visitors, you probably thought “What good are gulls anyway?” 

Researchers from the Universidade Federal de Goiás in Brazil now have an answer to your question. Seabirds like your annoying beach companions produce incredibly important and valuable excrement that is rich in nutrients such as nitrogen and phosphorus. This excrement (called guano) has been used as organic fertilizer since ancient times and is still collected and used in countries like Peru and Chile. Those two countries alone collected 27,000 tons of guano in 2018, which sold for $12.2 million USD. 

But bird guano isn’t just an important fertilizer for humans, it also fuels ocean ecosystems. To estimate just how important seabird excrement is, the researchers calculated how much it would cost to replace the nutrients excreted by seabirds with man-made versions, and found that seabird poop could be worth over $473 million per year. 

And that value does not even take other ecosystem benefits into consideration. For instance, a lot of reef fish rely on bird guano. The researchers valued the impact of bird guano on commercial reef fisheries at $650 million per year, increasing the total value of seabird guano to over $1 billion per year!

It may seem silly to put a dollar value on bird poop, but doing so is critical for improving conservation of these highly threatened species. So next time you find yourself cursing while wiping the bird poop off your favorite beach blanket, remember how valuable that bird and its poop can be. 

Disadvantaged people have a three-times larger "energy burden" than average households

"Systemic policies and historic underinvestment" drive the disparity

Jack Hawley

Oceanography

Humboldt State University

In a report published September 10th, researchers at ACEEE, the American Council for an Energy-Efficient Economy, found that “low-income households spend three times (8.1 percent) more of their income on energy costs compared to the median spending (2.3 percent) of non-low-income households.” 

The team of researchers measured energy burdens from 2017 in communities from 25 metro areas, places such as Atlanta, Chicago, New York City. By comparing households regionally and nationally, this team discovered that 25 percent (about 30 million) American households experience high energy burdens, spending more than 6 percent of their income on home energy. Half of those households (so about 15 million) experience what they call "severe burdens"  — where 10 percent of income is used on energy cost.

Black, Hispanic, Indigenous, and elderly households experienced disproportionate higher energy burdens. The researchers recommended further research on race, ethnicity, age and other factors affect affect energy burdens.

As rising temperatures affect portions of the US, energy usage will increase. Already high energy burdens for low-income communities will too. Identifying communities, increasing funding for energy efficiency, and weatherization are just some of the policy changes that can be implemented for a more energy security.

Coral reef restoration projects are not a long-term solution to biodiversity loss

Most outplanted staghorn corals in the Florida Keys don't survive past seven years

Sarah Heidmann

Fish ecology

University of the Virgin Islands

Coral reefs all over the world are suffering the effects of climate change. Coral restoration has become a popular conservation strategy to replenish coral coverage lost to bleaching, disease, and other factors. Restoration efforts could maintain genetic diversity and improve coral reef resilience, but how effective are these programs?

Studies on the success of such programs have found high costs and low long-term success. A paper recently published in PLOS ONE found that survivorship of outplanted colonies of staghorn corals in the Florida Keys was initially high but decreased after two years, when growth rates plateaued. After seven years, at least 90% of the planted corals had died. 

Overall, these outplanting efforts preserve genetic diversity in the wild and keep extinction of endangered species in check, but significant human intervention will still be required until external stressors are reduced. Outplanting requires huge amounts of proactive human effort, and provides only temporary relief to the suite of problems facing corals, namely, climate change and the associated issues of warming temperatures, acidification, and disease. The results show that these stressors are the problems we should be targeting if we want to save coral reefs.

A potential sign of life has been discovered in the clouds of Venus

Scientists found phosphine in the atmosphere, a molecule commonly associated with life, but stressed that they had not discovered life itself

Dan Samorodnitsky

Senior Editor

New data released Monday described the discovery of phosphine in the atmosphere of Venus. The poorly kept secret has been making the rounds since last week but were officially announced in a video from the Royal Astronomical Society.

Phosphine can be made in natural, non-living processes, industrially on Earth, and can also be made by anaerobic bacteria (living in the absence of oxygen). 

However, the scientists suggested that life "would struggle...in the incredibly acid atmosphere of Venus." 

The chemical structure of phosphine

"On Venus, the clouds are about 90% acid," said Jane Greaves at Cardiff University, who led the study. The results were published in Nature Astronomy on September 14th. 

"So is there really life on Venus? I really hope so, but we can't really tell with the results so far," said Greaves in the video.

Other scientists were cautious. Jessie Christiansen, a research scientist at the NASA Exoplanet Science Institute, tweeted:

Life is not the only explanation for the presence of phosphine, since there are geological and chemical events that can also produce it. However, the Cardiff group claims that they examined and ruled out all known possibilities that don't involve life. Phosphine was also discovered on Jupiter and Saturn as far back as 1975.

Josseline Ramos-Figueroa

Chemistry

University of Saskatchewan

Just as scientists are rapidly learning how SARS-CoV-2 affects humans, they are also quickly working to understand how it affects other animals.  House cats, tigers, golden hamsters, and rhesus monkeys are all susceptible to SARS-CoV-2 infection. And while avian species such as duck and chicken are not, dogs, pigs, and ferrets have shown intermediate susceptibility. 

The critical entry point for the virus into our cells is a protein called ACE2, which bonds with the spike protein of SARS-CoV-2. Animals and humans both expressing ACE2 in their cells, so scientists have been wondering why different species have different SARS-CoV-2 susceptibility, and if it is possible to predict which animals might be at risk.

In a preprint posted on bioRxiv in July, researchers at Vanderbilt University approached this question by comparing the amino acid sequence of ACE2 from different animal species. Amino acids are compounds that combine to form proteins. Inside cells, this amino acid chain folds into a three-dimensional shape. And as a result, some amino acids become hidden, and others exposed. Exposed ACE2 amino acids are of great interest because they determine whether SARS-CoV-2 can attach to the cell. 

Using computer models, researchers identified amino acids in ACE2 that showed strong interactions with SARS-CoV-2. They observed that in non-susceptible animal species, these amino acids were often different, ultimately disrupting the attachment between the ACE2 protein and the spike protein of SARS-CoV-2. This allowed the researchers to make predictions about which animals species are possibly at risk of infection. They estimated that while horses and camels would be vulnerable to infection, cows, goats, and Malayan pangolins would present intermediate susceptibility.

In August, another preprint from researchers at Dalhousie University in Nova Scotia examined whether marine wildlife are susceptible to the virus. Using similar modeling methods, these researchers concluded that whales, dolphins, seals, and otters would be susceptible to SARS-CoV-2. They suggest that exposure could happen through contaminated sewage entering the sea.

You can't tell a chimpanzee's age by its gray hairs

Unlike in humans, silver strands are not a good clue of old age in chimps

Laura Martinez-Inigo

Animal Behavior and Primatology

"To comb gray hairs" is a Spanish expression used to indicate that someone has reached a certain age, and they are not young anymore. It is an accurate idiom since, as we humans get old, our head hair generally becomes more gray. While little gray hair appears in the first half of our lives, once we reach midlife the color of our hair may totally disappear. But, is this the case in our closest evolutionary relatives? Can you tell a chimpanzee's age looking at the grey hair on their heads? 

To find out, a group of anthropologists took pictures of the faces of chimpanzees of different ages. They recruited 152 human observers, who were unfamiliar with these chimpanzees, and asked them to score the number of gray hairs they saw. 

The researchers discovered that hair graying in chimpanzees occurs at different times than it does in humans. Chimpanzees' hair becomes more gray from the time they are young up until the middle of their lives, but then the graying tends to stop. The opposite is true for humans, where graying is more striking from midlife on. They also found that a lot of variation between individuals, meaning that a 5-year-old chimp might have grayer hair than a 50-year-old ape. So, you cannot tell a chimp's age by the gray hairs on their heads!

It is unclear what the purpose of this difference might be, but it does indicate that going gray is not a reliable measure of age in mammals.

A new probiotic gel made of "good" bacteria helps treat yeast infections

This gel eliminates the need for antifungal remedies, which can cause recurrent infections

People diagnosed with a vaginal yeast infection are usually prescribed an azole-based antifungal medication. But many know that’s often the beginning of a roller coaster of recurrent vaginal infections. This is likely because azole antifungals ransack the “good” bacterial populations of the vagina even as they kill the yeast. 

A recent study published in Scientific Reports sought to leverage the idea that probiotics might be as effective as antifungals for yeast infections, while preventing the recurrences that so often follow the use of azoles. 

The research team behind the study knew that sizeable populations of Lactobacillus bacteria inhabit the vagina throughout the course of a yeast infection. They reasoned that certain Lactobacillus strains are great at producing lactic acid, and could inhibit yeast growth. They carefully selected the strains of Lactobacillus that seemed to work best in laboratory studies and developed a probiotic gel that could be used to treat yeast infections.

Past studies of probiotics administered vaginally during a yeast infection were always combined with the antifungal treatment standard. But this time, the 20 study participants were given only the probiotic gel, with an emergency course of the antifungal as back-up. The gel alone worked for 45% of the participants, those whose infections were relatively minor and not recurrent. With further tweaking and a lot more testing, azole antifungal treatments may be a thing of the past.

About 15% of maternity healthcare workers have COVID-19 antibodies, despite never being diagnosed with the disease

New research from London, UK, examines the risks to this group of healthcare professionals

Deanna MacNeil

Cell Biology

McGill University

Frontline maternity healthcare workers provide ongoing care to many people throughout their pregnancies, in addition to caring for those admitted to hospitals for delivery. Maternity healthcare workers have continued meeting the needs of pregnant people throughout the COVID-19 pandemic. And although COVID-19 may seem like a milder illness in some pregnant patients, we are just beginning to get an idea of the risk of transmission between maternity healthcare staff and patients.

A recent investigation into the number of undiagnosed SARS-CoV-2 infections among maternity healthcare workers was carried out in London, UK. Instead of relying on the nasal swab-based PCR assay with which we’ve all become so familiar, blood tests were used to look for antibodies against the virus, which would indicate previous infection. Out of 200 healthcare workers practicing in maternity wards, 14.5 percent (29 of 200 total) had antibodies against the virus, despite never having been diagnosed with COVID-19. 

This is in contrast to other types of healthcare professionals working in London who are more likely to be in direct contact with symptomatic COVID-19 patients, such as those working in the emergency department. Antibody testing in 200 such frontline healthcare staff revealed 45.3 percent had been infected with SARS-CoV-2.

Though the on-the-job risk of infection may be lower for those on the maternity frontlines than in other departments, the potential transmission risk posed to their colleagues, as well as to pregnant patients and their babies, is concerning. Out of the 29 maternity healthcare professionals with SARS-CoV-2 antibodies, 17 self-reported that they had continued working throughout the pandemic, either because they had been asymptomatic entirely or, if they did have symptoms, their symptoms did not qualify them for self-isolation at the time. 

A new study compares the viral make-up of people with and without rare brain tumors

Their results suggest the human virome may one day help treat certain cancers

Georgina To'a Salazar

Chemical Engineering and Biomedical Engineering

University of Texas Health Science Center at Houston

The human virome is collection of viruses inhabiting humans. This virome is important to study because these viruses can have important impacts on human health and disease. Next-generation sequencing, or NGS, analysis can reveal important differences between viromes. 

A team led by Zihao Yuan used NGS to detect virome differences between brain samples from healthy people and and from brain tumors of people diagnosed with glioblastoma multiforme, or GBM. Glioblastoma is the most aggressive type of primary brain tumor — most patients die within 18 months of diagnosis, even with advanced and invasive treatment

According to the new findings, unique characteristics of viromes in samples from GBM tumors point the way to potential new treatments. For instance, the researchers propose that a new virus found in GBM tumors could engineered to become oncolytic — capable of killing cancer cells. Other viral sequences contained structures that might be recognized by antibodies, which can also be used to kill cancer cells. 

Environmental stresses reshuffle ocean food webs, making them less secure

New experiments show important food web redundancies get left behind

Ashley Marranzino

Marine Biology

University of Rhode Island

We are often taught about the relationships between organisms as a one-lane, one-way street: the grass is eaten by the rabbit, which is eaten by the snake, which is eaten by the hawk. In reality, this food chain model drastically oversimplifies the complex web of interactions between species. Healthy ecosystems contain numerous species that can fill the same role. Instead of the rabbits only being eaten by a snake, for example, they might be eaten by a snake or a fox or a hawk. This built-in redundancy in ecological roles makes ecosystems more resilient to change. 

New research published in Science suggests that marine ecosystems may not have enough redundancy in their food webs to combat the cocktail of changes they could see in the near future.  

Researchers set up large-scale ecological experiments called “mesocosms” to test how ecosystems responded to ocean acidification, ocean warming, and a combination of both acidification and warming. While ocean acidification alone had little effect on the overall ecosystem health, scenarios testing ocean warming and the combined effects of acidification and warming both altered the food web, negatively impacting the ecosystem’s ability to function normally.

In addition to climate change-induced shifts in ocean environments, like ocean acidification and ocean warming, marine ecosystems face stressors like overfishing, habitat destruction, and pollution. While some species will tolerate changes and replace less resilient species, a shift in the fundamental balance of ecosystem functions could throw off the delicate balance of the ecosystem. Much like Skittles will not adequately replace apples in a nutritious diet, some species do not make suitable substitutions for others in an ecosystem. Without a healthy level of diversity, marine ecosystems may be ill-equipped to handle the inevitable changes to their environment. 

"Inactive" ingredients in drugs could have toxic side effects

These compounds increase shelf life, but their safety hasn't been systematically tested

Colleen J Mulvihill

Microbiology

University of Texas at Austin

Most of us give little thought to the ingredients inside the brightly colored pills that we rely on to keep our bodies functioning. We refer to them as an aspirin or antihistamine without realizing that for most drugs, the major component by mass is not the drug of interest itself, but compounds classified as “inactive” called excipients

While called inactive, excipients such as dyes, stabilizers, and antioxidants that increase shelf life have not been systematically tested to determine whether they interact with molecular targets in the body. Scientists recently analyzed a wide range of these compounds to determine potential unknown side effects. 

The authors first found interaction candidates by predicting how much an excipient looks to the native compounds that act on certain molecular targets, and then tested the hits experimentally. In another approach, the scientists tested widely used excipients against 28 targets that are known to be related to toxicity. Using these two approaches, the authors found 134 side-effect activities. Of these leads, some were further analyzed for their abilities to be toxic to the body and to enter the bloodstream. 

One finding was for an antiseptic commonly found in mouthwash. Predicted to interact with a number of biological targets, this compound was shown to be toxic to the body at low levels, and was able to enter the bloodstream at concentrations high enough to interact with at least one biological target. Overall, 134 side-effect activities for 38 excipients were found. 

This study highlights how compounds in our drugs not normally considered active can alter our bodies. The authors additionally note the widespread use of some excipients in food and cosmetics that are found at even higher doses than drugs, and the issue of populations that juggle more than one medication and therefore have a higher exposure. While a preliminary piece of work, it highlights the importance of paying close attention to what we add to substances that sustain us. 

We don't need to use baby talk to communicate with babies

Newborn and infants' speech perception skills are more astute than previously thought

Rashi Ranjan

Computational Biology

University of Pittsburgh

We frequently use baby talk in our best efforts to communicate with newborns, smothering them with strings of "goo goo" and "ga ga" until they smile or cry in return. But oversimplifying our language may not be necessary — scientists from Paris recently studied a group of newborns and found that their speech perception skills were more astute than previously thought. 

To perceive speech, our auditory system must be developed enough to differentiate the spectral (frequency-based features for pitch, rhythm) and temporal information (time-based features to interpret) that make up our speech. Studying how our brain processes information might help us deduce whether or not the foundations of language learning and speech comprehension are present from birth. If infants interpret these cues differently than adults do, they may also be absorbing different linguistic information, like envelope cues that aid in consonant identification. 

The basilar membrane in the inner ear receives speech by dividing the temporal modulations of the speech signal into different frequency bands. The researchers found that six-month-olds were able to differentiate consonants similarly to adults. Once this was established, they looked at how newborns interpreted different types of consonants. To discriminate plosive consonants (produced by stopping airflow using the lips/teeth and then a sudden release of air, such as in "t," "k," and "p" sounds), newborns required fast cues, as opposed to adults and six-month-olds, for whom slow cues were sufficient. 

This study showed the physically immature newborn brain is capable of processing the acoustic components of speech, which is the foundation of language learning. As opposed to adults, who can rely only on slow cues, newborns need fast envelope cues to perceive consonants. The specialization to different temporal cues reflects infants’ great speech perception skills despite limited language experience and an immature auditory system. 

Despite a flashy design, Elon Musk's Neuralink has little substance

Neuralink is one in a long line of brain-machine interfaces developed over the past 50 years

Thiago Arzua

Neuroscience

Medical College of Wisconsin

The idea of mixing brains with machines is nothing new. First proposed in the 1970s, brain-machine interfaces (BMIs) have already achieved a lot over the decades. Initial versions let people move virtual cursors, and more recent ones allow for full control of mechanical arms. As of today, the only FDA approved BMI is the Utah Array, a 1mm implant with 100 electrodes that can capture and stimulate brain cells. This array is currently on clinical trials as a treatment for several different diseases.

First announced in 2016, Neuralink entered this field with the stated goal of: “Solving important brain and spine problems with a seamlessly implanted device.” The implant, now in its version v0.9, is 23 x 8 mm and has 10 times more electrodes than the Utah Array. With functions like measuring temperature, pressure, and movement, a fast wireless connection and induction battery charging, the comparison to wearable devices is not hard to make. But it does still require brain surgery. This surgery, promised to take less than an hour, is almost completely done by an automated robot, also designed by Neuralink — at an estimated initial cost of $10-20 million.

Other concrete take home messages from yesterday's press conference was that Neuralink has been approved as an FDA Breakthrough Device, which speeds up the primary approval process with the agency. We also know that they are able to have multiple implants per animal, and they can interpret the neural data, as shown in a video that could predict the animal movement, likely through some form of machine learning algorithm. And...that was about it.

Despite claims about its potential, ranging from curing blindness to summoning your car and figuring out the secret to consciousness, the reality is that, so far, Neuralink has showed little more than a flashy new design for a BMI with more electrodes. The FDA approval might be the most exciting aspect. Given recent reports that the company culture is chaotic and clashes with a normal pace of science, regulatory oversight will be crucial to making sure that this product does not endanger people. Not to discredit the progress made by the company, but neuroscientists should not rush to stop the presses. 

Hepatitis C virus tracking could be made easier by next generation sequencing

The information from sequencing would help epidemiologists trace the disease

Marnie Willman

Virology

University of Manitoba Bannatyne and National Microbiology Laboratory

An estimated 50,300 people in the United States are newly diagnosed with Hepatitis C each year. With approximately 2.4 million people in the US already living with the virus, this presents a large healthcare burden to the global medical economy. Within this group, there is a proportion of people so often forgotten in the shuffle: injection drug users. 

Researchers, doctors, and scientists have been working to eradicate Hepatitis C for decades, but one of the biggest barriers faced is injection drug use. Sharing of needles and other supplies frequently transfers bodily fluids between people, which is how Hepatitis C virus is transmitted. And, just 7.7% of people who inject drugs are tested for Hepatitis C. This, among other challenges, such as the fact that people who inject drugs may face stigma and judgement when they seek out health care, makes tracking Hepatitis C difficult.   

A recent study examined the feasibility of using a method called next-generation sequencing to determine similarity of Hepatitis C virus strains between individuals. They found this is a feasible option that could provide epidemiologists with information such as how different strains in populations of people are related and where one newly infected person's strain of the virus may have originated. 

While this doesn't completely solve the problem of track-treat-eradicate, it does help with the tracking portion, which has been severely lacking. Testing for the disease tends to take a few days at minimum, and may require follow-up testing. Each step brings us closer to being able to treat and eradicate the disease, eliminating Hepatitis C virus from the globe, preventing the 8,000-10,000 deaths each year that it causes. 

Immature neurons in mammals' brains keep them adaptable

New research uncovers how neuronal plasticity is maintained in mammal cerebral cortices

Francesco Zangari

Molecular Biology

University of Toronto

The human brain is made up of billions of neurons that are interconnected to form the circuits enabling life. However, the brain is not static and neuronal connections can change, a phenomenon termed neuronal plasticity. Often this occurs by making new neurons, but this process is highly controlled as it poses risks for altering existing critical connections. As such, how those brain regions maintain plasticity has been a focus in research efforts. 

One of these brain regions of the brain thought to be relatively stable is the cerebral cortex, which is largely responsible for human cognitive capacity. However, a recent study published in eLife and led by scientists from the University of Turin demonstrate the cerebral cortices of 12 mammal species with a range of brain sizes — including the large-brained chimpanzees — achieve neuronal plasticity by maintaining a reserve population of immature neurons.

The researchers noted that larger cortices contained more immature neurons. However, one striking feature of these neurons is their characteristics are very similar across all 12 species. This suggests that these cells are very important in mammalian brains, as they have remained largely unchanged through years of evolution. 

It seems the cerebral cortex is more adaptable than once thought and that flexibility has been maintained through evolution. This work also highlights the need to continue studying these populations of immature neurons. The researchers call for similar investigations into immature neuron populations' potential role in maintaining proper connections in the brain. As we learn about these immature neurons, it may be possible to use this information to better predict cortex neurodegeneration, which often leads to conditions like Alzheimer’s Disease.

Machine learning can help maggots solve crimes

Trained algorithms can identify maggots and read clues like time of death

Asher Jones

Entomology

Maggots don’t have fingers, but they do produce chemical “fingerprints” — a blend of chemicals unique to their species. Different maggot species feed on corpses at particular stages of decay. Forensics teams actually use this information to estimate a person's time of death. The problem is that maggots, which are  immature flies, are tricky to identify and rearing them to flyhood is time-consuming and expensive. 

University of Albany researchers developed a machine learning technique to rapidly distinguish maggot species by their chemical fingerprints.

Because maggots collected at a crime scene are usually an assortment of many species, the team trained their computer program with mixtures of various combinations of six fly species. The researchers deciphered the chemical signatures of each maggot melange with a technique called mass spectrometry, which identifies chemicals on the basis of size and charge. 

After teaching the program to recognize the chemical makeup of each training mixture, the researchers assessed whether it could identify “test” maggot blends. The program accurately identified most of the test samples, suggesting that this technique could help forensic detectives establish time of death, a critical clue for solving crimes. The results are published in a recent issue of Analytical Chemistry.

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