Biodiversity hotspots and favorite papers

Cassie Freund


Wake Forest University

I've been thinking about a question for my fellow scientists lately:  What's one paper that you always use to contextualize your work, that you wish you could share with everyone because you just think it's SO DARN COOL?

Cassie Freund looks out over a tropical Andean forest landscape

Me and my Peruvian plants

Cassie Freund

Mine is "Biodiversity hotspots for conservation priorities." I love this paper because the authors came up with the 25  places on earth with the highest concentrations of plant and animal species. They argue that in an era of very limited funding for  protecting nature, focusing mainly on these regions will return the most bang for our conservation buck. And this paper is super relevant to my work because I study forests in the Tropical Andes, home to 45,000 plant  species. Nearly half of these (~20,000) can only be found in this hotspot.

There are hotspots for animal enthusiasts, too! The island of Madagascar - home to multiple lemur species, the fossa, and the so-ugly-it's-almost-cute aye-aye - is a prime example. There are now 36 hotspots, with eleven new ones added in the past two decades. Scientists, nature lovers, world travelers: is your favorite place on the list? Shout out at me about your favorite papers and hotspots on Twitter and I'll share your replies!

Map of biodiversity hotspots around the world

Map of the now-35 biodiversity hotspots worldwide. Is your favorite place on the list?

Conservation International on Wikimedia Commons

Do people realize when they get distracted?

New research tests people's awareness of their own awareness

Elliot Eva Ping

Cognitive Neuroscience and History of Science

Ohio State University

Visual search, or simply looking for something, is something people do daily. From scanning aisles for favorite products at the store to monitoring road conditions while driving, search is an essential function of human vision and attention. However, distractions can divert us, capturing our attention at inopportune moments.

Head in the sand

Head in the sand


But this isn’t always a negative. Our ability to get distracted plays an important role in alerting us to hazards, in advertising, and in education research. For example, bright, attention-grabbing colors are often used on road signs to alert us to important information. Metacognition, or self-knowledge about our thinking, can help us understand these real-world behaviors. But do people always know when they get distracted? 

A new study published in Attention, Perception, and Psychophysics explored this question. Participants engaged in a series of computer-based search tasks where the goal was to find a target shape on the screen, situated among other shapes. In some trials, a colorful distracting shape was added to the array. After some trials with a "distractor" present, the researchers asked the participants to report whether or not they had been distracted. When the participants got distracted,  it took them longer to perform the task at hand: reaction times are longer in these trials than in those when they weren’t distracted. By comparing these reaction times to participants’ claims of being distracted or not, the researchers came to a conclusion. People are typically aware of when they get distracted. However, performance wasn’t perfect, and study participants didn’t always catch when their attention had wandered. 

This suggests that people can often, but not always, tell when they are distracted. This may lead us to a better understanding of how we cope with distractions, and future work may indicate how people can be more aware of distraction and learn how to avoid it when necessary. 

Tracking specific hair cells reveals how stress causes gray hair

The science of why stress changes hair color

Sara Wong


University of Nottingham

It's no surprise that chameleons can change colors to pink, blue, orange, red, and black. These color changes are partly mediated by stress. For example, stress increases dark gray pigmentation of tawny dragon lizards. That same stress and color change relationship also applies to human hair. Hair graying has long been associated with increased stress and aging. But little actual evidence as proven science behind this observation. 

A team of scientists from Harvard University have now explained this mystery. 

For hair follicles to grow, they go through three main phases: growth, degeneration and inactivity. The growth phase activates two population of stem cells, one called hair follicle stem cells, or HFSCs, and another called melanocyte stem cells, MeSCs. Activation of HFSCs produces hair follicles. Activation of MeSCs produces fully formed melanocytes, which migrate to the base of the hair follice and make the melanin that colors hair. Melanocytes die and degenerate, and the cycle repeats with a new cohort of melanin-producing cells. 

But where in this cycle does stress play a role?

When researchers caused pain-induced stress in rats, it triggered a fight or flight response, which in turn increased production of noradrenaline. Noradrenaline, generally functions to increase action and attention in the mind and body and binds to the surface of MeSCs. This stress effect accelerated the MeSCs growth cycle, pushing the cells to become melanocytes and possibly causing them to migrate elsewhere.

After the end of a cycle of stressed hair follicle growth , remaining MeSCs were also reduced. Interestingly, decreased MeSCs also occur with age. That effect on MeSCs resulted in less mature melanocytes and thus less pigmentation in subsequent hair follicle growth cycles. 

After years of empirical evidence, it is exciting to understand the role MeSCs may play in stress and if it contributes to the accelerated ageing process.  

Ed.: Originally this article was published with an image of Claire Saffitz as an illustration of someone with gray hair. It was pointed out to me that this is an unfair and hurtful use of a person's appearance. I apologize for the error and have changed the photo to a stock image. -DS

The Milky Way's supermassive black hole might have enabled the evolution of life on Earth

Chemical reactions caused by the X-ray emissions from the black hole could have spurred water formation

Keir Birchall


University of Leicester

No matter which origin of life theory you subscribe to, water is a key component. A new pre-print study takes one step beyond to consider how water became so abundant in our galaxy, the Milky Way. The researchers present evidence that the Milky Way’s central supermassive black hole, Sagittarius A*, might have made the Milky Way a much nicer place to live.

When supermassive black holes consume galactic gas and dust, they emit huge amounts of radiation, temporarily becoming active galactic nuclei (AGN). Similar activity in other galaxies appears to correlate with an increased density of water and other organic molecules conducive to life, which occurs as X-rays from the AGN remove electrons from previously neutral atoms and molecules. This release of free electrons can accelerate the creation of organic molecules.

The researchers constructed a computer simulation of a molecular cloud containing dust grains and gaseous chemicals. They tested what would happen if they exposed the cloud to X-ray irradiation, like that from an AGN, for a million years. The AGN was then either switched off or allowed to continue emitting for a further 10 million years. Both these scenarios were compared to a simulated molecular cloud which experienced no X-ray irradiation.

When the AGN kept emitting X-rays, more water formed on the surface of dust grains in the molecular cloud compared to the model without irradiation, and this trend appeared even when the AGN was switched off. The explanation for this is that irradiation can increase the rate at which hydrogen molecules split, speeding up water formation.The simulation experiment also found that too many X-rays could eventually lead to a decrease in gaseous water, which suggests that there is a "sweet spot" for X-ray emissions where water can form and persist.

Computer models like these are complex with assumptions that may not perfectly reflect reality, but they can also be really useful for understanding past events. The study shows that X-ray emissions from an AGN could have a substantial effect on the abundance of water in the Milky Way. 

When COVID-closed labs reopen, who will be there?

Coronavirus is going to make "normal" research impossible, so adjust your plans

Gabriela Serrato Marks

Marine Geology

Massachusetts Institute of Technology

As research institutions in the US begin to plan for operations that look more like "normal," it's critical that we take an inclusive approach to reopening. Some labs – like the one I work in – are planning to open in a limited capacity in the next few weeks. There will be lots of restrictions in place to keep everyone safe, from temperature checks to required distancing, down to calculating the number of square feet per person. But as we reopen, we should make sure that all lab members are equally able to come to work. Here are a few questions to ask yourself, or your supervisor, as your lab plans to reopen. 

Is anyone in a high risk group? What about their families and roommates?

When you read about how people at higher risk for severe illness should be extra careful, you may only think of older adults. But people with underlying medical conditions are also part of that group. You might not know that a grad student is on an immunosuppressant medication, or that a postdoc takes care of their grandparents on the weekends. How will your reopening plan impact those people? There are no easy fixes, but make sure you identify and respect people's boundaries around working in person. 

Who is comfortable working alone? 

Some lab work is inherently dangerous. With appropriate training and procedures, we decrease the risk of spilling large quantities of acid or starting a fire, but the risk never goes to zero. Working alone means that there might not be anyone around to help if an accident does happen. Is your institution's environmental health and safety department even working? Plus, survivors of trauma might feel unsafe or vulnerable as the only person in their lab, or one of few people in an entire building. To address some of these concerns, make sure your lab has emergency protocols in place and your building is secure. Allies are particularly important here: if you are not worried about working alone, you can volunteer for later shifts. 

Have schools and childcare facilities reopened? 

The pandemic is already having a disproportionate impact on women in academia. If labs reopen before childcare options are available, it's possible that mothers won't come back to reopened labs at the same rate that fathers do. Groups could allow caregivers to set their own schedules, like working every other day or at off-hours, or continuing to work remotely until their usual childcare is restored. 

I don't have all the solutions to these considerations, but I do know that we need to put people before science. If we take an equitable look at our next steps, science will be better off.

Native bees are better for the environment and altogether cooler than honey bees

Celebrate native bees for World Bee Day, not imported honey bees

Lila Westreich

Pollinator Ecology

University of Washington

Honey bees have been celebrated by humans since they were first domesticated for pollination and honey production in the earliest days of human civilization. But honey bees are expendable  —  we can purchase them from other countries, ship them overseas, and raise them in a non-native land to pollinate our crops. If all of the honey bees in the U.S. died today, we’d buy more tomorrow. This World Bee Day, we should focus our celebration on the lesser-known species of amazing native bees that fill our environment.

Iridescent green sweat bee, called because it is known to be attracted to sweat

Iridescent green sweat bee, called because it is known to be attracted to sweat

Via Wikimedia

World Bee Day was established by the United Nations to recognize the fundamental role of pollinators in pollination services, food production, and to safeguard biodiversity in the face of their many threats. It was not only in recognition of honey bees and the pollination services they provide, but of all bees. The proclamation specifically acknowledged and raised awareness of the urgent need to conserve all of the 20,000 species of native bees worldwide.

A blueberry bee, Osmia ribifloris, a blue-colored bee native to North America.

The blueberry bee, Osmia ribifloris, a blue-colored bee native to North America.

Via Wikimedia

Native bees are absolutely some of the coolest insects on earth. They come in a huge variety of shapes, sizes, and colors. Social species with a single queen  —  like bumble bees  —  make up about 10% of known bee species. Social bees live in nests and work together like honey bees to raise their young and forage for food. The other 90% are solitary species, meaning they live alone and are solely responsible for finding food and building a nest.

Stelis louisae, from Prince George's county Maryland. A red and black

Stelis louisae, a red/orange carder bee


Native bees come in a variety of colors besides yellow and black — blue, green, orange, and red, to name a few. Some resemble wasps, as a defense mechanism for survival. Others are covered in tiny hairs, resembling giant teddy bears, or almost entirely hairless and smooth. Native bees are responsible for a majority of wild plant and crop pollination worldwide.

There are so many amazing native bees. Unfortunately, the focus generally lands on the domesticated workhorse Apis mellifera, instead of any one of the amazing native species. Native bees face a wide range of threats from lost habitat due to increasing development, lack of flowers for food, agricultural intensification, pesticides, and so much more. Honey bees actually pose a threat to native bees, introducing competition and spillover of diseases and parasites to native bees.

An all black bee, Dufourea monardae

An all black bee, Dufourea monardae

Cole Cheng/USGS

There are a wide variety of studies in native bees, but educating the public is one of the best ways to encourage native bee conservation. So this World Bee Day, take some time to read up on pollinators, and learn what you can do to help our native bees.

On this World Bee Day, we ask: why are bees so fascinating?

Is it their honey or their hive, or is it because they can jive?

Sahana Sitaraman

Neuroscience and Behavior

National Centre for Biological Sciences, India

On this day nearly three centuries ago, Anton Jansa was born into a family of Slovene beekeepers. He joined the family business and went on to revolutionize beekeeping. To celebrate his contributions and the insects he spent his life studying, May 20th is designated as “World Bee Day.” But the day is also about much more than just that. 

Every time you eat a bowl of vegetables or fruit, chances are you have a bee to thank for it. 35% of the world’s food crops depend on pollinators like honey bees, bumblebees, stingless bees, butterflies, hummingbirds, wasps and many others. Despite being so valuable, they face unprecedented extinction rates from human actions. Something that each of us can do to combat this is to not only educate others on the contributions of pollinators, but to shed light on how incredibly cool they are.

Apis florea

Apis florea pollinating flower

Ebi Antony George 

In that spirit, let me tell you a few things about honey bees that will leave you amazed. 

Honey bees have one of most unique communication systems. When a bee finds a nice, juicy flower patch, it tells its nest mates by doing a waggle dance. This dance relays the location (direction and distance) and perceived quality of the nectar source. Varying dialects of the waggle dance are used by different honey bee species to accommodate for different foraging ranges, likely dependent on food availability in their environment.

Apis cerana queen

Apis cerana queen


Honeybees, as well as a few other species, also have a distinctive way of reproducing called "haplodiploidy". Male drones develop from unfertilized eggs and female workers from fertilized ones, and one queen lays all of them. But in one sub-species called Apis mellifera capensis, the workers also lay unfertilized eggs, which develop into daughters. Years after its description, scientists recently discovered the gene responsible for biological anomaly. 

All of this only scratches the surface of honey bee biology and comes from decades of research. Unfortunately, studies on other bees are grossly lacking. But with pollinator populations dwindling, it’s crucial that we learn as much about them as possible to come up with better solutions for their conservation.

Surgeons can feel a robot’s hands performing surgeries for them

Scientists at Texas A&M developed a system using electrical pulses to help surgeons using the hands feel what they are doing

Sarah Anderson


Northwestern University

Although a “robot hand” might sound like something out of a science fiction movie, highly functional robotic hands are being developed for use in surgeries. Robotic hands are more compact than human hands, which reduces the size of the incisions needed to accommodate them. Robotics may also allow surgeries to be performed remotely, enabling surgeons to protect themselves in the case of, say, a global pandemic.

The major hurdle facing surgeon-guided robotic hands is the inability to accurately gauge the position of the hand in space. That’s because with the loss of a human hand comes the loss of proprioception, the innate spatial awareness of the body (this is what allows you touch your finger to your nose, even though you can’t see it). In a new study, researchers at Texas A&M University have developed a strategy to create the sensation of proprioception while using a robotic hand. 

They delivered continuous electrical shocks — the intensity of which correlated with the proximity of the hand to its target — to the operator’s fingertips. They found that this technique enabled better distance perception than simple visual processing, and could therefore prevent excessive (and potentially damaging) force between the robotic hand and delicate tissue during surgery.

Genome analysis of Lactobacillus bacteria finds that they make up 25 distinct groups

These bacteria are important for gut health as well as in foods like kimchi, sauerkraut, and yogurt

Lauren Sara McKee

Microbiology, Biochemistry, and Biotechnology

KTH Royal Institute of Technology

One of the most important groups of probiotic bacteria – both in terms of their impact on human health and for their economic significance – are the Lactobacilli. These are the ones you especially find in yogurts and yogurt drinks that heavily advertise their probiotic virtues.

The Lactobacillus genus is one of oldest known groups of bacteria, and the first species was named in the early 1900s. More recently, the genus has been called one of the most significant on the planet, because of its impact on human health and societal development through its role in innovations like food fermentation.

As of March 2020, over 250 species belonged to the genus Lactobacillus – and this has started to cause problems for scientists, who note that there is a wide diversity of form and function among the group, which is not apparent from the extensive use of the Lactobacillus name. We need a simple way of telling these species apart.

To address these issues, and to tidy up the scientific record, the authors of a new study in the International Journal of Systematic and Evolutionary Microbiology have analysed the genome of every existing Lactobacillus species, and they now propose that these species constitute 25 distinct genera. The new groupings make more intuitive sense, with bacteria serving similar functions now classified together.

The new naming system might eventually have an impact on probiotic food labelling, which may need to get a lot more specific about which species are present. Luckily, the researchers have provided a handy web tool that can be used to find the new names of species.

In the backrooms of university and museum buildings are archives of life on Earth. Stored in jars and shallow drawers, these collections keep time: evolutionary time that is.

Scientists classify organisms by their shape and physiological traits to understand the relationships between species. No matter if King Phillip Came Over For Good Spaghetti, these classifications are not a set of rules. However, they can be constraining.

Classifying organisms

Classifying organisms


Differences in teeth and skull shape has made classifying one family of fishes complicated. The goal of taxonomy is to organize species in a way that shows evolutionary lineage of an organism; all species within a group should share a common ancestor. Scientists aren't confident that this is true within a particular genus of ghost knifefishSternarchogiton.

Advancements in technology have enabled scientists to analyze the hereditary material of organisms. This is useful for mapping out lineages, however, molecular studies have shown conflicting results on the relationships between species of ghost knifefish. What does seem clear is that the traits currently used to qualify an animal as a ghost knifefish are not confirmation that the species share a common ancestor. 

Researchers collected specimens of Sternarchogiton preto, a species of ghost knifefish within the genus Sternarchogiton. They dissected and analyzed the specimens and found four traits unique to S. preto. One of those was is the presence of three cranial soft spots compared to the two found in other species.

Based on their observations the team placed it into a new genus, Tenebrosternarchus, and renamed the species T. preto. Other ghost knifefish may be discovered or redescribed but to be added to Tenebrosternarchus they must share traits and a common ancestor with this "type species." 

The concept of a species is the topic of spirited debate in the scientific community. Still, it is important to describe them properly. Classifying and describing species helps us make sense of the world around us and it has practical applications in research and our daily lives.

Female toads breed with a different species when it helps their tadpoles survive

Could changing environments lead to more hybridization?

Caitlyn Finton

Behavioral Neuroscience

Cornell University

There are many barriers for reproduction between different species. So many, in fact, that hybridization — breeding between species — is rare and considered "an accident" within populations. Many hybrids are sterile and cannot pass on their genes; the few fertile hybrids are often unable to find mates or produce healthy offspring themselves.


A saucy flirtation


Why, then, would the Mexican spadefoot toad and the plains spadefoot toad be seen hybridizing so often? Is it possible that these toads actively hybridize based on the current environment?

Although male hybrids are completely infertile and female hybrids are less fertile than their parents, hybridizing can be adaptive for the plains spadefoot. Spadefoot tadpoles develop in desert ponds that often dry up before the tadpoles are adults, resulting in their death. Hybrid tadpoles, however, develop faster than pure plains spadefoot tadpoles. This increasing the chances of the tadpoles reaching adulthood and passing on their parents’ genes.

Mexican spadefoot toad

Mexican spadefoot toad

National Parks Service

In a recent study published in Science, researchers investigated what traits of Mexican spadefoot males lead to healthier offspring. They bred plains spadefoot females with a variety of Mexican spadefoot males and found that males with the slowest vocal calls had offspring that developed the fastest.

Females were then presented with vocalizations from either a fast-calling or a slow-calling male, in either a shallow pond — where hybridization is advantageous — or a deep pond — where it is not. Swimming towards certain calls indicated preference. They found that females preferred slow-calling males, but only when they were in shallow ponds. In deeper ponds, they had no preference. Plains spadefoot females are actively choosing to hybridize specifically with males that will have fast developing offspring only when there is a chance that ponds will soon disappear.

This active choice by female plains spadefoot toads gives their offspring an adaptive advantage, ultimately allowing for the continuation of plains spadefoot genes in the population. Across the animal kingdom, this work begs the question: will active hybridization become more common as habitats change and some species are more adapted to the current environment than others?

Celebrating lasers and photonics on the International Day of Light

Innovations in harnessing light, from individual photons to laser beams, have revolutionized our world

Simone Eizagirre


University of Cambridge

The laser is a fundamental component of many everyday electronic devices: barcode scanners in supermarkets, laser printers at the office, CD players (remember those?), computer drives, and so on. 

The International Day of Light is celebrated on May 16th every year, commemorating the first successful operation of the laser by Theodore Maiman in 1960. Sixty years since, lasers have brought us much more than an abundance of funny cat videos — lasers and other light-based technologies have completely revolutionized the world we live in.

Light plays a crucial role in the telecommunication systems that bring us mobile networks and the internet. For example, fiber-optic cables are used to send information in the form of light pulses over long distances, and bring high-speed internet into our homes. Laser communications also have huge potential for improving communication in outer space, an area of active research.

Lasers are important tools for spectroscopy, which looks at how materials interact with light. For instance, scientists can study how bonds form during chemical reactions using ultrafast pulsed lasers. Researchers have also used lasers to trap individual particles in so-called “optical tweezers”, a technique used popularly in biophysics to study DNA. Understanding the nature of light-matter interaction and the mechanisms that underpin it has been key to developing new photonic devices such as light-emitting diodes (LEDs) for cheaper and more energy-efficient illumination, and improving solar panels for better energy harvesting.

There are countless other examples of incredible work in the field of photonics. Lasers have been a gamechanger for the medical industry, where new imaging techniques enable better diagnostics and laser-based treatments such as photodynamic cancer therapy have emerged. More fundamentally, the field of quantum optics investigates how individual photons of light can be generated and controlled, which will be essential for the development of quantum communications in the future.

We owe laser physics and photonics the world we live in today, and it is clear that the study of light will continue to play a key role in shaping our tomorrow.

Freshwater species boom in the time of the insect apocalypse

A new study summarizes findings about the fate of insect species across 166 studies and 41 countries

Olivia Box

Natural Resources and Forest Ecology

University of Vermont

The insect apocalypse is here. It is estimated that over 50 percent of insect species have disappeared since 1970, and currently 41 percent of insect are at risk of extinction. But new research from a team in Germany shows it’s not all black and white — rather, it’s terrestrial and freshwater. 

A study published in Science found that while terrestrial insect abundance has declined by 9 percent, freshwater species have increased by 11 percent. This complicates the idea of the insect apocalypse — while many species are at risk of disappearing altogether, land use changes and conservation play a large role in the narrative of disappearing insects.

The group examined long-term insect monitoring studies, tracking insect abundance across ecosystems. They examined over 1600 sites across 166 studies in 41 countries. Studies in protected areas showed weaker trends, strongest trends were found in unprotected areas. Urbanization, agriculture, and other land use changes could all be possible drivers of terrestrial species disappearing.

Improvements in water quality over time could be a contributor to the abundance of freshwater species, suggesting habitat protection and restoration may be an effective way to combat species decline. But, it’s not a one size fits all solution. Roel van Klink, the lead author on the study, thinks insect conservation should be a priority: “Insect conservation is not necessarily different than conservation of larger species, but is more difficult, because there are so many more species of insects and they all have their needs”.

Using artificial intelligence to discover new treatments for superbugs

Machine learning is pointing researchers toward molecules that are structurally different from current antibiotics

Fabiola De Marchi


University of Padua

Antimicrobial resistance is an emerging threat to healthcare systems worldwide. As a consequence of the spread of drug-resistant bacteria, also called “superbugs,” medical treatments could become ineffective for an increasing number of people in the next years. To fix this huge problem, chemists are asked to find new effective antibiotics. 

Drug discovery is an expensive and time-consuming process during which pharmaceutical chemists look for new candidate molecules to interact with a particular target protein or pathway causing the disease. Chemists screen large libraries of thousands to millions of molecules, looking for compounds with specific biological effects and low toxicity. However, these screenings are not very efficient: if chemical libraries don’t include molecules with enough structural diversity, chemists will fail to discover antibiotics with molecular structures different from the ones already tested in laboratories or clinical trials. 

Now machine learning is flanking chemoinformatics through innovative deep neural network approaches to find new drugs. An example of how this approach works can be seen in a recent study by James Collins and coworkers at MIT. First, researchers trained a neural network model to predict growth inhibition of Escherichia coli using a set of 2335 diverse molecules; then, they applied the optimized neural network model to screen large chemical libraries with more than 107 million molecules. 

They ended up with a list of candidate molecules structurally different from known antibiotics, and ranked them based on their predicted biological activity. Among those candidates, they found that halicin, a compound under investigation as a treatment for diabetes, displayed high efficacy against E. coli and a large spectrum of pathogens such as Acinetobacter baumanii, at the top list of resistant bacteria which urgently requires new antibiotics.

Research groups are currently developing similar deep learning approaches to find new compounds that could fight the COVID-19 virus. This suggests how recent improvements in machine learning can assist chemists' work to speed up and lower the costs of the drug discovery process.

An extra 1 part per billion of pollution comes with an 8 percent increase in COVID-19 mortality

Environmental protection and coronavirus are inextricably linked

Kathryn Atherton


Boston University

The quality of air in your community can have a huge effect on your health. According to the World Health Organization, a third of heart disease, lung cancer, and stroke deaths can be attributed to air pollution exposure.

As the COVID-19 pandemic has suddenly caused the world to turn upside down, answers for how to slow the spread and improve outcomes for those already ill are needed. Researchers at the Harvard T.H. Chan School of Public Health realized that there is a significant overlap between the underlying conditions that put people at high-risk for severe COVID-19 illness and health issues that are caused or exacerbated by air pollution, and wanted to know if the two are directly related.

The research team looked at air pollution and COVID-19 death data from over 3,000 counties across the United States, being sure to consider variables that might affect the results like population density, social distancing policies, and percent of people that are at high-risk for severe COVID-19 illness from other factors such as smoking and old age. 

Their results showed that an increase of just one part per billion (PPB) in long-term air pollution exposure is significantly associated with an 8% increase in the COVID-19 mortality rate. 

The authors noted that their results show how important it is to continue enforcing our air pollution regulations. Despite this and other evidence that air pollution leads to a number of public health concerns, the United States Environmental Protection Agency proposed relaxation of environmental rules during the pandemic 

Hand hygiene isn't implemented rigorously across the world, even in health care

It's not always easy to get alcohol or soap-based washes where they are needed

Farah Qaiser

Molecular Genetics

University of Toronto

May 5 was World Hand Hygiene Day. This year, the World Health Organization’s (WHO) “SAVE LIVES: Clean your hands” campaign takes on increased significance amid the COVID-19 pandemic.

In a recent letter in the Journal of Hospital Infection, three researchers outlined that hand hygiene with alcohol-based rubs are one of the most effective measures to prevent COVID-19 cross-transmission among healthcare workers. This seems obvious, especially now, but despite the many coordinated campaigns and efforts in the past, hand hygiene has yet to be implemented rigorously across the world.

Hand hygiene is often difficult to achieve in over-crowded healthcare settings, and in settings where resources may be limited. For example, in 2016, in eight out of 55 countries with data available, more than half of health care settings lacked appropriate handwashing facilities (i.e. water and soap or alcohol-based hand rubs) at points of care, as per a global baseline report compiled by the WHO & UNICEF. 

To complicate matters further, healthcare workers, especially nurses, are often exposed to infectious pathogens, must work long hours and may have limited access to the necessary personal protective equipment in an infectious outbreak like COVID-19. With all of this in mind, it is important now, more than ever, that everyone practices hand hygiene rigorously.

The WHO proclaimed 2020 to be the Year of the Nurse and the Midwife, so it’s unsurprising to see that their specific calls to action include calling on nurses and midwives to take special care with cleaning their hands, and for policy makers to increase staffing levels to improve the quality of healthcare. Similarly, the CDC has issued a Clean Hands Count Campaign to address myths around hand hygiene.

So yes, please go wash your hands. Plain soap and water will do, and if your skin is getting too dry, find a greasy or thick cream to apply. Just don’t stop washing your hands.

Supreme Court ruling protects Hawaiian reefs from contaminated groundwater

Counties and businesses cannot pump contaminants into the ocean, even "indirectly"

Laura Lyon

McGill University

The U.S. Supreme Court recently ruled in favor of environmentalists six to three on a historic case involving the scope of the Clean Water Act. Maui County, Hawaii was sued by environmental groups over federal water quality permits because pollutants from the county’s wastewater treatment plants were seeping into the ocean, devastating local reefs. The county argued that it did not need permits because wastewater was pumped into groundwater wells, which they claimed did not count as being discharged directly into a “navigable water body” – such as oceans, lakes, and rivers – as specified by the Clean Water Act.

Scientists at University of Hawaii, Manoa performed a groundwater tracer study and concluded that 64% of wastewater from the plant was reaching the ocean through groundwater, with an average travel time of 15 months. 

The court’s ruling clarifies that permits are needed for indirect water contamination that is the “functional equivalent” of directly discharging contaminants into surface waters. Opponents claim that the ambiguity of what “functional equivalent” means can put businesses, counties, and homeowners in trouble for not acquiring permits.

On the other hand, the ruling has been considered a win for science. The application of the Clean Water Act to groundwater has been open to interpretation, and regulation often falls under the domain of states. But it’s challenging to draw boundaries between groundwater and surface water since the two systems are hydrologically connected, making it ambiguous where one set of regulations end and the others begin. 

This ruling closes a loophole in the Clean Water Act and broadens its definition of what counts as direct discharge into federal waters, emphasizing this hydrologic connection. Scientific evidence will now be central to future cases, giving federal waters more protection from pollutants.

West Nile Virus-carrying mosquitos managed to survive a German winter

Europe is usually too cold for tropical diseases to persist for long, but climate change helped it overwinter

Marnie Willman


University of Manitoba Bannatyne and National Microbiology Laboratory

The summer of 2018 in Germany was the second hottest and driest year on record, and while this made for a beautiful season of beach-side fun, it also brought a deadly disease with it. The West Nile Virus (WNV) outbreak of 2018 was a single-introduction event, thought to be from the Czech Republic. The infection was detected in wild and aviary birds such as owls and blackbirds, in addition to horses. This was the first documented occurrence of WNV in these birds in Germany. When the outbreak was declared over, a sigh of relief was felt across the country. But the problem was far from over. 

In 2019, the European Centre for Disease Prevention and Control declared another WNV outbreak. The 2019 outbreak was determined to be due to transmission from resident mosquitoes to birds and horses, as is typical of WNV. The difference was in that birds and horses could be infected by being in the same area as an infected animal, even if they didn't directly overlap there in time. This suggested that the virus was living in the environment itself, making it infinitely harder to control. While horses cannot transmit the virus, bird and mosquito transmission that can survive and be spread indirectly in an affected area is a scary concept. 

The 2019 outbreak also suggests that the WNV infected mosquitoes managed to overwinter successfully. Many tropical diseases are not a problem for Europe, North America, and other countries with cold winters because they and/or their hosts die in the cold, and must be re-introduced to return to the same area. But these mosquitoes managed to survive the German winter

This is most likely linked to climate change. Diseases that used to be restricted to hot climates are now spreading globally because they can survive in ever-warmer climates. This could only be the tip of the iceberg, as researchers predict we will see more tropical diseases invade traditionally cooler areas. 

As scientists look to the skies to track mosquitoes, birds, and changes in sunlight hours and temperature, we can only wait and see if the prediction will come true. 

Got a sweet tooth? Your gut bacteria are asking for some sugar

The gut microbiome and the brain communicate on a desire for glucose (in mice)

Thiago Arzua


Medical College of Wisconsin

From kids with sugar rushes to grandparents who swear they just need one more bite of chocolate, humans absolutely love sugar. In an evolutionary way, it makes sense. Sugar used to be relatively hard to come by, and it is packed with valuable calories. Recently, however, our relationship with sugar has been complicated, to say the least. 

In the US, we consume an average of 2.5 cans of soda everyday, far exceeding any nutritional guidelines. While we continue to study why our brains love sugar so much, a group of scientists showed that it might not even be, technically, our fault. 

The team from Columbia University found that the gut-brain axis (the connection between bacteria in your gut and your brain), is essential in the sugar preference of mice. The scientists directly injected either glucose or an artificial sweetener to the guts of mice, and saw an activation of different regions of the brain when glucose was present, but not with the artificial sweetener. 

Next, they genetically silenced that specific brain region, which completely took away the mice’s preference for sugar. They were also able to modify that region to induce the mice to enjoy new flavors.

One of the key things in the study is that all of the action is happening away from the tongue. This shows that there are circuits inducing our love for sugar, beyond our love for sweet tastes. This also helps explain why artificial sweeteners have not changed our consumption of sugar, since they fail to activate this new gut-brain circuit. Although we need to verify how this translates to humans, this new circuit offers new exciting insights.

Drones are better than tissue samples for measuring humpback whale body conditions

The two metrics perform similarly for much of the year, but aerial images capture changes during the breeding season where tissue samples do not

Fernanda Ruiz Fadel

Animal Behavior and Behavioral Genetics

University of Tübingen

In order for researchers to keep track of animal populations, it is necessary not only to know how many there are but also how healthy they are. This often requires tissue or blood samples, but for large animals such as whales, collecting samples is very difficult and it can interfere with their natural behavior. Humpback whales go through especially extreme body condition changes throughout the year. They migrate from their polar feeding areas to warmer breeding grounds, during which time adults spend months without eating. 

Researchers measure changes in body conditions of migrating whales by checking the lipid content of their blubber layer – a layer of reserve energy that keeps them warm and allows them to go without eating for long periods of time. They can also use drones equipped with small cameras to measure things such as body length and volume from aerial images. However, in order to find out if the different measurement methodologies are reliable, they need to compare them.

So, a group of researchers in the coast of south-west Australia collected drone images and blubber samples from the same individuals of Humpback whales at the beginning and end of the breeding season to find out if the external (body shape) and internal (blubber fat, measured by tissue biopsy) measurements correlate.  

They found that the body volume of the whales decreased through the breeding season. This was expected since the adults are fasting and females are nursing their calves during this time. However, they found no big changes in the fat composition of the blubber layer during the same period. These results differ from other species of whales and it signals that for humpback whales, monitoring their body sizes is a more accurate and less invasive metric than tissue samples for checking if the populations are being able to feed well and reproduce. 

Parasitic wasps murder insects with a smallpox-like virus

...and other words everyone is happy to hear

Marnie Willman


University of Manitoba Bannatyne and National Microbiology Laboratory

In the virus world, smallpox and other poxviruses are horrifying. Despite the fact that smallpox was successfully eradicated in the 1970s, the entire family of poxviruses still strike fear into the heart of scientists.

But if you're a parasitoid wasp, poxviruses are essential. Parasitoid wasps are no stranger to being outcasts. These  wasps make their living by laying their eggs inside other insects so their larvae can slowly eat away the host and release the mature insects fully fed and ready to reproduce. Frightened yet? It gets worse. 

parasitic wasp

Parasitic wasp attacking an aphid

Wikimedia Commons

These wasps carry a type of poxvirus, Diachasmimorpha longicaudata entomopoxvirus (DIEPV) in their venom glands. This virus has evolved with them, and is now built right into their genes, to be passed on to the next generation of parasitoid wasps. But why would this trend of evolution be a good thing for the wasps?

New research sheds some light on why this convergent evolution has occurred from the perspective of the wasps themselves. It turns out that DIEPV is particularly deadly for flies, and other small insects. This means that when the parasitoid wasp lays its eggs inside the unwilling host, the DIEPV virus grows along with the pupa, and kills the host even faster, releasing tissues and destroying organs for pupal digestion faster than the natural process. Thus, parasitoid wasp offspring mature, are released, and reproduce faster with greater success because DIEPV helps them kill the host. After this true-life horror story, the cycle repeats again so that these young wasps can make new wasps of their own. 

So next time you swat a wasp and feel your heart beat a little faster as you avoid being stung, imagine the unfortunate fate you would be facing if you were an insect confronting a parasitoid wasp. Now that is pretty scary. 

Need a memory boost? Try sleep and exercise

But probably not at the exact same time

Hannah Thomasy


University of Washington

The internet is full of advertisements for supplements and brain-training games to help improve your memory, most of which are of questionable efficacy. Now, a new study from researchers at Concordia University in Quebec provides scientific evidence for a way that people can improve memory. Best of all, it’s completely free. Here’s the secret: exercise and then take a nap. 

No, that's not a joke.

Scientists first randomized participants into one of four groups: those who exercised and napped, those who only exercised, those who only napped, and those who didn’t do either. In the morning, participants randomized into one of the two exercise groups did 40 minutes of moderate-intensity cycling. Then in the early afternoon, all of the groups were shown 45 different pictures. Half the participants were then allowed to nap for one hour. In the early evening, all of the participants were shown 90 pictures and asked to identify which ones they had seen earlier than day.

The Sleeping Beauty by Walter Crane (1876)

Via Smithsonian Libraries

On this declarative memory task, neither exercise nor napping alone increased memory performance. However, the group that exercised before learning and napped afterwards had significantly better accuracy on the task compared to groups that only exercised or only napped. This suggests that exercise and sleep act synergistically to improve memory. Future research could examine whether this finding holds true for other types of memory tasks or whether the time of day that people exercise influences the effects of exercise on memory. 

Captive butterflies have duller, shorter wings, and weaker grips than their wild counterparts

Is captive rearing really the answer to monarch butterfly conservation? Maybe not, according to this new research

Monarch butterflies are a key pollinator and complete an arduous migration as part of their life cycle. Conservationists worry about their rapidly declining numbers, as the butterflies battle against climate change and pesticides. To tackle this, people are breeding them in captivity, and releasing them when they are fully grown. 

To the untrained eye, captive butterflies are just as beautiful as wild ones. Scientists know that their migration skills aren’t as fine tuned as their wild counterparts – a process which is essential for the butterflies to successfully lay their eggs. To understand why,  Researchers from the University of Georgia put some captive raised butterflies through their paces, to see if their beauty and brawn's lives up to that of their wild cousins. 

Both captive and wild butterflies performed a grip test. By measuring the force needed for the butterflies to release their grip on a branch, researchers discovered that the captive butterflies strength was not up to wild standard. Captive butterflies also have much paler and shorter wings than wild butterflies.

These three traits are essential for successful migration. Grip strength, in particular, is what the butterflies need to latch onto branches and trees when resting or if winds become too severe.

In captivity, there is no “survival of the fittest.” The butterflies are reared and nurtured, and most of them survive. If these captive butterflies mate with the wild population, their offspring might be at a big disadvantage. Beyond that, the authors of the paper note that their findings explain a trend of decreased migratory success in captive-reared monarch butterflies. 

Viruses may solve the problem of antibiotic resistant bacteria

It has worked in mice and moths, but human trials are just now getting going

Sridevi Ranganathan

Infectious Diseases

University of Maryland

Antibiotics changed the face of medicine since their introduction in the 1940s. Before antibiotics came into widespread use, if a person accidentally scraped their hand and the wound became infected, there would have been a 1 in 10 chance that they would lose the limb. Antibiotics changed that.

However, the overuse and misuse of antibiotics have led to several bacterial pathogens becoming notoriously resistant to them. Therefore, scientists have been looking for alternate ways to treat bacterial infections. One such approach is bacteriophage therapy.

Bacteriophages are viruses that prey on bacteria. They infect their target bacterium, multiply, and break it open, thereby killing it. So, can we send in these sneaky viral hunters to kill bacteria that can't be killed by antibiotics?

Last year, researchers in South Korea showed that a novel bacteriophage they isolated from hospital sewage water (yes, you read that right) was active against 17 out of 40 antibiotic-resistant strains of A. baumannii that they tested. These researchers infected wax moth larvae and mice with antibiotic-resistant A. baumannii followed by treatment with the bacteriophage. The moth larvae and mice that were given the bacteriophage survived much longer than the ones that were infected but not treated. In fact, 100% of the mice infected with A. baumannii and treated with the bacteriophage survived, whereas mice that did not receive bacteriophage treatment died within five days of infection.

Mice and moths, sure. How about humans?

Last month, researchers in Australia enrolled 14 critically ill patients with bacterial sepsis caused by drug-resistant S. aureus bacteria into a safety trial for bacteriophage therapy. These patients were given a cocktail of phages with activity against drug-resistant S. aureus strains, along with the standard regimen of antibiotics to treat the infection. Phage therapy did not cause any adverse reaction in these patients and was associated with a reduction in bacterial burden and less inflammation.

Much needs to be done before bacteriophage therapy can become mainstream in humans. However, this study is an important step forward in understanding if bacteriophage therapy will be our ally in the war against drug-resistant bacteria.

We can measure coronavirus's spread by looking at people's poop

Municipal wastewater treatments plants are actually ideal testing locations

Lauren Sara McKee

Microbiology, Biochemistry, and Biotechnology

KTH Royal Institute of Technology

Many scientists are following the same rules of social isolation as everyone else. University labs around the world have closed, and we are pivoting to working from home, delivering lectures, supervising students online, and putting our research on ice for now.

Other scientists have completely turned their research programs around to start contributing to the fight against COVID-19. This includes heroic efforts to develop new screens for infection, new antibody assays, and rapid new blood tests. A very different kind of project has been started in many cities, including my adopted home of Stockholm, Sweden.

Researchers around the world now believe that, because most infected individuals shed the virus that causes COVID-19 (SARS-CoV-2) in their feces, it is possible to detect the virus in sewage (wastewater) and thereby track its spread through a city. 

Wastewater treatment plants are the ideal testing site, as they typically serve one municipality where the citizens are also served by the same healthcare centers. The virus can be detected even at low levels, suggesting that wastewater testing could be a powerful surveillance tool to monitor circulation of the virus in a local area, and perhaps give an early warning of a resurgence in cases. 

Projects are ongoing in the Netherlands at the KWR Water Research Institute, in Stockholm at the Science for Life Laboratory and the Royal Institute of Technology, and at institutes in Spain and Turkey, and there is growing global interest in the results.

These efforts will complement the ongoing work to roll out antibody testing that will tell local authorities roughly what proportion of their citizens have been infected without showing symptoms – knowledge that might let some people start returning to work earlier than anticipated.

One person's techno trash is a scientist's research tool

It's hard to study plant roots, but a plastic CD case makes it easier to observe a plant's underground activities

Cassie Freund


Wake Forest University

Plant roots are complex and delicate structures that provide the aboveground stem and leaves with nutrients and water. Studying them can tell us a lot about a plant's survival strategy and its associations with soil fungi and bacteria. There's a lot going on beneath our feet that we just can't see.

And that's part of the problem: roots are very difficult to study because they are hidden below layers of soil. To measure and observe roots, plant biologists must either dig up the plant, an approach aptly referred to as "destructive sampling," or install a see-through chamber called a rhizotron. A rhizotron is kind of like an ant farm: it allows you to observe what is going on in the soil though a clear panel. But rhizotrons can be expensive and, depending on a scientist's research goals, not worth the effort it takes to construct them.

plants growing out of a CD case

CD case rhizotron

Steven Cassidy

Now, a group of biologists from the University of Pittsburgh have developed an inexpensive and simple mini-rhizotron from a now-defunct household object: a plastic CD case. Their method was published in April in Applications in Plant Sciences. The case itself is filled with soil, and the growing plants protrude from the hinge. Because plants can sense and grow in the direction of gravity, storing the CD cases at an angle forces the roots to grow up against the see-through sides of the cases, making them easy to see and measure without disturbing the plant.

This method only works for studying small plants — there is no CD case large enough to grow a tropical tree! But it's a clever method that fills a scientific need, and one that the authors hope will make root research accessible to teachers, ecologists, agricultural scientists, and other researchers no matter what financial resources they have available.

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