Lab Notes

We all encounter stress in our daily lives, but new research is revealing that the way you respond to stress and adverse experiences may be inherited from your parents. Paternal exposure to stressors creates long-lasting changes in germ cells (sperm and eggs) that may be inherited by future generations and determine how they react to stress.

In a recent study published in the Journal of Neuroscience, researchers exposed male mice to chronic stress, then measured how it affected the stress responses of their male and female offspring, produced both through natural mating and artificial insemination. They discovered that offspring displayed the same stress phenotype as their fathers. For example, a father deemed susceptible to stress had offspring that showed more anxiety- and depression-like behaviors when they were exposed to stressors in adulthood, whereas resilient fathers had resilient offspring.

Interestingly, the transmission of stress phenotype occurred in both the offspring resulting from natural mating and those from artificial insemination. This finding indicates that the stress-induced alterations in sperm directly contribute to stress phenotype transmission. The researchers also discovered that exposure to stress drastically affected sperm RNA sequences. 

This study provides new insight into how stress responses can be inherited across generations and the role sperm RNA plays in transmitting stress susceptibility or resilience. So, the next time you respond well to a stressful life challenge, you may just want to thank your dad!

Something’s moving on Venus. Scientists know the planet doesn’t have plate tectonics like Earth, but recent research has discovered some chunks of rock that have visibly moved, hinting at something interesting going on below the planet's surface.

By re-analyzing data from the Magellan spacecraft (which visited Venus all the way back in the 1990s!), these researchers found regions called “campi” on the surface of Venus. Like chunks of ice floating on our oceans, campi are large, flat hunks of rock atop Venus’s molten mantle. They move around, dragging through surrounding rock and scarring the landscape, making marks visible in images.

So why should you care about jiggling rocks? Paul Byrne, one of the astronomers leading this study, tweeted that that “modern Venus might also hold clues to early Earth...and Venus might also tell us what to expect on planets that are Earth-sized — which basically means Venus-sized — orbiting other stars.” Looking at our sister planet can tell us more about how planets, including our own, work. Also, these investigations can hopefully answer the question of why Venus is so unpleasant while Earth is habitable and teeming with life.

With multiple missions to Venus coming up — DAVINCI+, VERITAS, and EnVision — scientists are eager to take a closer look at the surface, including these intriguing moving rocks.

With our species’ long history of creating alcoholic beverages, it is easy to forget that alcohol occurs in nature too. All kinds of wild animals routinely consume alcohol, including non-human apes, birds, and flies. The western honeybee has even emerged as a model species for studying the effects of alcohol consumption.

Honeybees consume alcohol when wild yeast grows in flower nectar. The yeast in nectar produces ethanol through fermentation in the same way that brewers’ yeast produces ethanol in beer. In the lab, honeybees will readily drink sugar water spiked with alcohol, which mimics this yeasty nectar. Using this method, scientists have shown that honeybees can get intoxicated and eventually build up a tolerance when they drink alcohol regularly.

Although alcohol use disorder in humans is driven by a complex set of biological and social factors, studying honeybees may help us understand some of the fundamental physiological processes underlying it. With this goal in mind, a research team in Poland ran an experiment to see if honeybees showed one of the key features of alcohol addiction: withdrawal.

In their recently published study, the researchers fed half of the bees sugar water with ethanol, and the other half without ethanol, for three weeks. After that, half of the bees in each group were switched to the opposite diet for three days. The researchers then tested how eager the bees were to drink alcohol-spiked sugar water.

The bees that had never encountered alcohol before consumed the least of it, while the bees that had been cut off after three weeks of alcohol-drinking consumed the most. These bees drank more alcohol than any of the other groups, including those that had consumed alcohol continuously throughout the experiment.

The researchers concluded that honeybees show signs of alcohol withdrawal after just a few days of deprivation. Of course, more research is needed to fully understand the basis of the bees’ behavior and what it means for alcohol studies more broadly. But it is evident that at least some of alcohol’s impacts on animal behavior are more widespread than we once believed.

Epilepsy is a medical condition in which increased electrical activity in the brain causes seizures. There are medications available to prevent seizures for most people with epilepsy who choose to seek treatment. For about one-third of treatment-seeking people, however, there are no effective medications.

Now, scientists may have discovered a new way to prevent seizures from a surprising source: tree resin.

The results were recently reported in the journal Epilepsia by a team of researchers at Linköping University in Sweden. The team was studying a group of molecules called resin acids, which are found in the liquid that oozes out when a tree is cut or a branch falls off.

The scientists produced chemically-modified resin acids and found that some of the chemically-modified resin acids can cause a subtype of potassium channel to open. These channels, located on the surface of neurons (cells that transmit information in our brains), decrease the electrical activity in the brain when opened. When these channels are closed for too, long electrical activity in the brain can become dangerously elevated and cause a seizure.

The researchers also found that some chemically-modified resin acids prevent seizure activity in the larvae of small fish called zebrafish. The study is just the first step on the long road from testing in zebrafish to testing in humans, but the results are encouraging for the development of anti-seizure medications.

Oozing through moist soil and leaf litter, the amoeba Dictyostelium discoideum (better known as the slime mold) kills bacteria, primarily yeast, to extract its nutrients and replicate. The amoeba can even farm bacteria to prevent starvation or to “save them” for later generations. And in addition to providing nutrients, these bacteria can become the amoeba’s army and protect them against environmental toxins.

However, in a recent study published in the Proceedings of Natural Academy of Sciences, scientists have found that the D. discoideum is not unbeatable. The research team found that two different species of bacteria can team up to become a lethal meal for D. discoideum, poisoning and killing the slime mold in the process. One their own, these two bacteria cannot defend themselves against D. discoideum. But together, they "cook up” a highly toxic poison to defeat their common enemy.

The researchers revealed that only one of the bacteria, a type of Pseudomonas, could produce syringafactin, a key component that its partner, a type of Paenibacillus, uses to make the deadly concoction. Syringafactin, is formed on the outside of the bacterial cell and is not itself toxic to the slime mold. But when Paenibacillus is around, it carves the syringafactin into highly poisonous pieces that ultimately kill D. discoideum.

“The cleavage products not only affected the lab strains of amoeba but also wild type [or naturally occurring] strains making this a broad spectrum defense strategy,” said Somak Chowdhury, member of the research team, in a Twitter post about these findings.

This cooperative bacterial interaction provides a clear example of a community-level defense-mechanism type against predators. Whoa!

The Pacific Northwest, especially the state of Oregon, is in the throes of a historic heat wave.  During the summer of 2021, it became hotter in the normally mild Willamette Valley than in such heat prone places as Las Vegas and Abu Dhabi, at 111 degrees Fahrenheit. 

Although the heat wave has now mostly abated — though the current wild fires are so intense, they are creating their own weather systems — there are still dire predictions of the effect of the heat wave in the Pacific Northwest’s many diverse ecosystems, which range from high deserts in the central part of the state to the rainforests on the coast. 

First, the heatwave massively lowered the snow in the Cascades Mountains, which will deprive rivers necessary for keystone species, such as salmon, of the cool water they need. This will decrease the salmon population, which both humans and animals rely on for food. Additionally, although the heat wave has ended, the effects of the higher temperature will also increase the likelihood of more wildfires throughout the state, similar to last summer’s horrifying infernos in the McKenzie River Valley and elsewhere. This is predicted even in such places as the Oregon Coast, a temperate rainforest that was previously safe from wildfires, but was devastated by wildfires in September 2020. 

Though scientists and state officials are trying to find ways to keep people safe from these effects of climate change, it may be too little, too late, for much of the state's river systems, which are projected to lose most of the snow melt by 2100. This will have widespread effects on Oregon's wildlife and ecosystems. 

In 2001, the first draft of the human genome was published. It consists of an extremely long succession of the four letters, ATGC, that make up our genetic code. Think of this published genome as the reference picture on a puzzle box: Scientists worldwide can compare the genome of any person to the reference and thereby identify important differences.

However, eight percent of the human reference genome is still missing. These missing pieces lie in regions that are full of repeating letters, which were hard to decipher with the technology available in 2001. However, deciphering these regions, which are involved in crucial cellular processes, could enhance our understanding of a multitude of genetic conditions.

In May 2021, two decades after the first draft of the human genome was published, an international group of scientists reported in a pre-print that they have sequenced those missing pieces, creating an almost complete human reference genome.

To achieve this milestone, the scientists combined two new sequencing technologies, which allow for sequencing longer stretches of DNA at a time. Like in puzzles, these larger pieces are easier to put together, allowing the researchers to determine the sequences of the highly repetitive regions that had been missing from the reference genome.

They sequenced the genome of a cell line derived from cells that form when a sperm fertilizes an egg with no nucleus. Since these cells contain genetic material only from the father, the scientists do not need to distinguish between chromosomes from the two parents. However, the sperm from which the cell line was derived carried only an X chromosome. Consequently, the new reference genome lacks the sequence of the Y chromosome. The researchers are already in the process of sequencing also this last missing puzzle piece.

If these results pass the thorough peer-review process, they will be a major step forward in completing the reference picture of our genetic puzzle.

Picture this: a day with clear sky, children playing around a lake, and a picnic blanket spread out on the grass with people ready to enjoy their meal. This is a simple summer scene that researchers at University of Montreal propose to use for a rapid assessment for language impairment, known as aphasia, a common outcome after stroke. People with aphasia may encounter difficulties ranging from speech production to comprehension. And, it is difficult to predict how long it will take a person to recover.

In-hospital speech pathologists encounter another challenge to correctly evaluate people with aphasia: Detailed assessment batteries exist, but these take time and tend to be exhausting. The researchers at University of Montral, led by Amélie Brisebois, have developed a new evaluation, by analyzing the description of a picnic scene from the Western Aphasia Battery, a classic language assessment test. This test was conceived to explore the discourse abilities of patients, or in other words, how they describe, without further instructions, an image or stimulus. A closer look at their descriptions may tell us more than we think.

The researchers investigated a variable called thematic units (TUs), which are specific references to the people or ideas present in a scene. For example, the picnic scene includes mentions of “child”, “drinking”, “dog”, “fishing”, and so on. They analyzed how patients referred to the elements in the picture, both during an initial evaluation and then in a follow-up six months later.

Brisebois and her colleagues found that the quantity of TUs a person with aphasia expresses after a stroke is correlated with the recovery of their general language abilities. This simple assessment can give clinicians cues to make faster and accurate predictions of long-term recovery in people with aphasia and invites both researchers and clinicians to explore more naturalistic ways to assess language impairments. 

Disclosure: The author is a student at the same research lab as Amélie Brisebois and other authors of the published study, but did not participate in the study described here. 

With more than 75,000 new cases of kidney and renal pelvis cancer anticipated this year, it can be reassuring to know that diverse kinds of treatment exist, such as immunotherapy and targeted therapy.

Although great strides have been made in this field, treatment resistance is still a concern. Unfortunately, "acquired resistance" to first-line therapy is quite prevalent in patients, so more treatment options are still needed.

In a study recently published in the journal Scientific Reports, researchers from Kanazawa University in Japan tested whether two compounds found in coffee beans, called kahweol acetate and cafestol, could be used to treat renal cancer, after obtaining encouraging results regarding their usefulness against prostate cancer. The research group found that the two compounds together synergistically reduced cancer cell proliferation and migration. They also demonstrated that these two compounds reduced the expression of cell proteins linked to the transition from one cancer cell type to another, signaling between immune cells and cancer cells, and the prevention of programmed cell death (a process in which cells destroy themselves before they become cancerous).

These findings demonstrate that these two compounds, present in your morning coffee, have strong potential in the fight against renal cancer.

Cystic fibrosis is a genetic disorder that affects multiple organs like the lungs and pancreas. It is caused by a mutation a gene called CFTR, which results in the production of a dysfunctional CFTR protein. This protein helps balance salt and water within a cell by acting as a channel for chloride. A mutation in the CFTR protein causes dehydration of mucus secretions and an excessive loss of salt in sweat (salty skin). As a result, some people with cystic fibrosis experience mucus clogs in their airways and are susceptible other complications such as respiratory failure, inflammation, and infection.

In the US and some other developed countries, the initial diagnosis for cystic fibrosis involves measuring specific protein levels from dried blood spots or DNA-based mutation testing. However, these tests are invasive and don't always produce accurate results. Cystic fibrosis can be also diagnosed by testing a person's sweat, to measure their chloride levels and determine whether they have the dysfunctional CFTR protein.

But, collecting enough sweat to do the tests can be a problem. To address this, the researchers behind a new study published in Science have developed a gentle “sweat sticker” that can be used to accurately assess chloride levels outside of clinical and hospital settings. It uses microfluidic technology to rapidly collect chloride levels in a person's sweat, and chloride levels can be analyzed from images captured with a smartphone camera to provide a diagnosis. This relatively simple yet elegant system remains to be tested in a large group of people (this study only had 51 participants), but could make diagnosing cystic fibrosis much easier in the future.

Big congratulations to Jeff Bezos, who rode torturous working conditions for his employees, an avalanche of monopolization that put small business into the dirt, and a rocket ship that looks like a penis into 10 minutes in low-Earth orbit.

Bezos and his space tourism company, Blue Origin, see this as the first step towards mining space for resources that humans can use on Earth. As reported in Politico, Bezos got this bad, utopian idea from a Princeton professor Gerard O'Neill, whom Bezos met as a student.

Bezos is not alone in promoting grandiose ideas for sustaining human existence while also enriching himself. Elon Musk has a whole brand built on this sort of thing. He also wants to build a Mars colony. Mars, by the way, is an unlivable deathtrap.

There are really only two goals for futurist-capitalists like Bezos and Musk. One is to colonize other planets for human habitation after Earth has been made unlivable. The second is mining planets, asteroids, and comets for water and metals — an idea I can't believe anyone takes seriously. Take the problem of water: Water scarcity is an issue on Earth because humans are catastrophically bad at using it efficiently, even when we're not simply dumping feces and industrial pollution into it. While there are certainly water crises on Earth, the solution is not launching to space and mining ice from an asteroid with technology that doesn't exist. It needs to be managed, kept clean, and made available, but water is here. Earth has water. 

Nearby asteroids don't. The grand total of asteroids that are even conceivably within grasp of any kind of mining is 28. An estimate of all near-Earth asteroids' freshwater supply, about 20,000 asteroids, calculated that they collectively contain between 100-400 billion gallons of water. That is approximately the amount of water the United States uses in one day. 

There are no answers for humanity's current crises in space. I live in Minneapolis, a city famous for brutal winters and tolerable summers. It's been above 90^oF for about eight weeks straight now, setting multiple local temperature records. Is Bezos going to find a new climate out in space?

The only correct thing to do, instead of fly to space and play Buzz Lightyear, is fix the only planet we have. All the things wrong with Earth now — catastrophic heat, deadly floods, droughts that arrive like accelerating clockwork — can still be fixed. There is no need for doomerism or hopelessness or bonkers ideas about space. Focus on Earth.

It is extremely clear that Bezos, Musk, and their ilk don't have humanity's best interests at heart. It only makes sense that space colonization and mining wouldn't really help ease humanity's suffering so much as it would make them both richer. On Blue Origins website is a vision statement:

“In order to preserve Earth, Blue Origin believes that humanity will need to expand, explore, find new energy and material resources, and move industries that stress Earth into space."

This is nothing more than a tacit admission, from Bezos himself, that capitalism can't coexist with human life. Incredibly, I agree with him. But flying to space on their phallic rocket ships isn't going to help. That will just leave us with the problems – climate change, poisoned water, income inequality – that Bezos and the others profited off of. They've demonstrated they cannot responsibly reinvest their wealth — so we'll need to do it for them.  The only just thing to do is tax those robber barons into destitution and never speak their names again. We can put that money to better use on Planet Earth.

Almost immediately at the start of the pandemic, it was clear that age was a substantial risk factor for experiencing severe COVID-19. But how aging impacts our immune function has been a difficult puzzle to solve.

To answer this question, researchers designed a new study to analyze genetic data from over 700,000 people identified from five biobanks in the United States, United Kingdom, Northern Europe, and Japan in a genome-wide association study. They focused specifically on age-related mosaic chromosomal alterations (mCAs), which are large DNA rearrangements including mutations like deletions or duplications of parts of the DNA, in white blood cells. These mCAs accumulate in our blood as we age and have been previously established as risk factors for blood cancers.

In this Nature Medicine study, the researchers found that mCAs were associated with a 170 percent higher risk of sepsis and a 40 percent increase in risk of respiratory infections. This increased risk was even higher among individuals who had previously been diagnosed with cancer.

The fact that mCAs were associated with higher numbers of infections makes sense: mutations that alter large parts of white blood cells' DNA limit the ability of these immune system warriors to fight against foreign pathogens that cause sepsis, the flu, and even COVID-19. And in an additional analysis of 871 people who had COVID-19 during the first wave of the pandemic in New York, the researchers found that 17 percent of severe cases had mCAs, compared to just six percent of mild cases.

This research highlights one of likely many links between age and infection-related risks. Identifying individuals with these genetic markers could prevent the severe disease outcomes that are likely in this group. 

In 2019, 44 percent of older Americans reported playing video games at least once a month. Part of this trend is seen in the rising popularity of game-like brain training programs such as Lumosity (which alone boasts over 75 million users), which promise improvements in memory, attention, and decision-making skills. But are these claims backed up by research?  

One early study found effects of working memory training on intelligence, sparking a field of research focused on potential training benefits. After initial promising results, subsequent studies failed to replicate these findings. Often studies find some evidence of “near transfer”, or a training boost to specific skills, but fail to see “far transfer”, or benefits to general cognitive performance.

A 2021 study set out to determine the effectiveness of brain training programs in over 8,000 online participants, including 1,000 people who reported being active users of a brain training program. If these programs are as effective as they claim, then these active users should outperform the other participants on tests of memory, verbal ability, and reasoning skills. The participants came from a variety of countries, education levels, genders, and ages, a major strength of this study. The self-reported brain trainers actively used at least one program, and had used programs for anywhere between two weeks and five years.

The researchers found no evidence of an effect of brain training. Active brain trainers did not perform better on any cognitive measure than people who do not use these programs. Furthermore, no effect was found for any demographic group, such as age, education or socioeconomic status, or specific brain training program, further bolstering the conclusion that these programs are not effective.

The researchers found one significant result: people who believed that brain training was effective, regardless of whether they actually used them or not, counterintuitively performed worse on cognitive tests compared to people who didn’t believe these programs are effective. Whether or not people believe these games work, they seem to have little benefit to general cognitive function. Play games for enjoyment, not with any expectation of a major cognitive boost.

Late last week saw Germany's deadliest natural disaster in nearly 60 years, as severe flooding hit the nation and other parts of Western Europe. As of July 19th, the floods had killed 200 people and injured 700. About 1300 people were still missing from just the Ahrweiler district near Cologne. 

The floods were caused by an extreme rain event, where nearly twice the amount of rain that the region usually sees in a month fell in just two days. This disaster should drive home the point that climate scientists have been frantically trying to communicate: Climate change is happening now.

There may well be more floods to come. A paper published in Nature last year examined flood data for Europe from the past 500 years. The scientists, members of 34 different research groups, found that the past 30 years belong to one of the most flood-rich time periods in Europe, one of just nine such periods over the past five centuries. They also discovered that, while the previous eight flood-rich periods occurred during relatively cold periods, the most recent one is markedly warmer (by about 1.4 °C) than all of the others. 

While the researchers did not explicitly attribute this current flood-rich period to climate change, they did highlight its "exceptional nature." As environmental journalist Andrew Revkin pointed out on Twitter, the reason this flood-rich period is so dangerous is that Europe is more developed and populated than it was over the past five centuries. Eighty-three million people live in Germany alone, and while the monetary damage has not yet been calculated, only about 45 percent of buildings are the country are insured against rain and flooding.

The flooding is also a reminder that climate change is affecting, and will continue to affect, the whole world. Yes, even the Global North. Everywhere. For instance, while the German floods have dominated the news, Oman is also seeing unseasonable rainfall and flooding that wiped out farmers' crops and disrupted the Eid Al Adha holiday.

We are currently way behind fighting climate change on all fronts. It is clear, though, that we have two main and urgent tasks ahead of us: mitigation and adaptation. The impacts of climate change are already deadly serious – let's get to work.  

Hiccups are annoying. To get rid of them, we rely on remedies that often feel more silly than effective, like breathing into a paper bag, holding our breath, and pulling on our tongue. Now, scientists have developed a device called the “forced inspiratory suction and swallow tool” (FISST) that stops hiccups, sans paper bags and tongue-pulling.

Hiccups are triggered when something irritates the nerves controlling your diaphragm, a large muscle nestled beneath your lungs that regulates respiration, causing it to spasm. Air rushes into your lungs as a result of these spasms, which causes your epiglottis, a flap of cartilage that covers your windpipe during swallowing, to quickly close. This produces the audible “hic” that accompanies a hiccup.

The FISST consists of a drinking tube with a mouthpiece and a pressurized valve at the bottom — essentially a glorified straw. Users place the FISST into a glass of water, drink, and swallow. This suction and swallow sequence stimulates diaphragmatic contraction and epiglottis closure to end an hiccup episode. When researchers gave 249 people who reported having hiccups at least once a month a FISST and asked them to rank its effectiveness compared to home hiccup remedies, they found that the FISST stopped hiccups in nearly 92 percent of cases. People were also happier with the FISST than their go-to home techniques. 

While these results are subjective, they provide encouraging evidence that the FISST relieves hiccups, and form a basis for assessing its efficacy in clinical trials down the line. If the FISST works as well as this study suggests, it could be a game-changer for folks experiencing transient and chronic hiccups alike.

If you look up in the sky, you might be able to find Orion, one of the most recognizable constellations. There’s been an ongoing mystery in that patch of space involving Betelgeuse, one of Orion’s “shoulders”, and a humongous, bright red star nearing the end of its life. For some inexplicable reason, when astronomers observed it in February 2020, it was far fainter than it should have been.

Known as Betelgeuse’s Great Dimming, the star appeared only ¼ to ½ as bright as usual, a much bigger change than usually observed in any normal star. For an old supergiant star like Betelgeuse, this is suspicious — astronomers first thought that this change could be a harbinger of the star’s death, an indicator that it might explode into a supernova soon. But new research published in Nature just uncovered the true culprit behind the dimming: dust.

Although this is less dramatic than stellar death, dust is an important and sometimes pesky part of astronomy. The whole universe is filled with it, it’s key to so many processes in space, and it often gets in the way of astronomical observations. Old supergiant stars like Betelgeuse are known to eject gas as they pulsate, which can form dust clouds around them. The new observations of Betelgeuse show that dust ejected from a cooler patch of the star shrouded the star’s southern hemisphere, producing the dimming scientists observed last year. This whole ordeal has provided great insight into how the biggest stars age and die.

So while the Great Dimming was not, in fact, a signal of the star’s imminent death, that doesn’t mean Betelgeuse is guaranteed not to explode anytime soon. And when it does, it’ll surely be a grand show in the night sky.

What would an RNA molecule today have to say about the origins of life? We live in a world where cellular life is dominated by DNA, but this wasn’t always the case. The Origins of Life…Again is a speculative look at the future from the perspective of an RNA molecule if she was able to take agency for her own destiny. Instigated by an NSF funded project that is using synthetic biology to investigate the origins of life — RNA imagines a future based on the past, one that leads to insight on RNA-based viruses, the limits of fully synthetic genomes, and potential extraterrestrial life.

We have synthesized functional genomes of viruses, bacteria and simple celled organisms, but are we able to replicate life that no longer exists on this planet? Before DNA became indispensable to cellular life, there was an RNA world in which RNA performed all the functions, produced all the proteins necessary for transmission, replication, and evolution, aka life. RNA can even do the work of proteins...without proteins. Creating an RNA-based organism in the lab that self-replicates would shed light on how we transitioned into our DNA-based world.

This is exactly what our RNA character is investigating as she shuns her repetitive messenger job within the DNA factory to engineer her own likeness. RNA is inspired by the past - a rollercoaster world full of possibilities — as a way to build a new future. Can RNA create an entirely new form of life using new rules, and what does that mean for biology?

If successful, this will (hypothetically?) be the first time in billions of years that cellular life with an RNA chromosome will grace the surface of the Earth. Fully synthetic genomes, including artificial genomes that go beyond what could evolve in known life, will enable us to answer questions about life’s origins and to extend the rules that set life’s limitations.

To animate is to bring to life and animation is a lot like synthetic biology — both have near infinite creative capacity under the guidance of a few rules and certain tools. To match the transformative potential of the research, we took a meta angle and wondered what life itself would think of the origins of life. In creating a figurative universe it’s possible to envision new hypotheses and subvert traditional metaphors within synthetic biology. Metaphors always break down at some point, and the more radical a proposal, the quicker they crumble.

The original research project delves into the cultural aspect of science from the outset and includes an ethics and rhetoric component, pieces to be explored in future animations.

Presented by The Johns Hopkins University.

It’s hard to imagine Earth without land plants. Yet, terrestrial environments were plant-less for the first 3.5 billion years of Earth’s history. Plants transitioned to terrestrial life as early as 432 million years ago. The benefits of moving to land for plants probably included more light and carbon dioxide for photosynthesis. The first land plants faced challenges inherent to their new lifestyle; they had to adapt to drying out, and lower nutrient conditions and higher UV radiation than they encountered underwater. However, primordial plants had some help in overcoming these new challenges.

Today, many terrestrial plant species grow associated with mycorrhizal fungi, which attach to plant roots and facilitate plant water and nutrient uptake. One study found that 80 percent of plants surveyed had these fungi. Many plants depend on fungal partners for successful growth. In turn, the plant provides its fungi with sugars for food and lipids which form the structure of its cell membranes. According to DNA and fossil evidence, these symbiotic relationships are ancient, and they are hypothesized to have been essential in allowing ancestral plants to colonize land. Now, a new study published in Science provides the first experimental evidence that supports this hypothesis.

The scientists reasoned that if the symbiosis between mycorrhizal fungi and land plants is an ancestral (simply, very old) trait, extant land plants should share a response to mycorrhizal fungi that was inherited from their common ancestor. Conversely, if the relationship with mycorrhizal fungi developed more recently, different types of plants should have different responses to mycorrhizal fungi. The researchers compared how a species of liverwort, a primitive terrestrial plant group, and flowering plants responded to a mycorrhizal fungus.

Their experiments revealed that liverworts and flowering plants share genes that respond similarly to mycorrhizal fungi. These genes are involved in the production of plant hormones, infection responses, and the transfer of lipids, which were identified as essential in driving this symbiosis. The results show that primitive land plants respond to mycorrhizal fungi in the same way as flowering plants, supporting the hypothesis that symbiotic relationships between plants and mycorrhizal fungi are ancestral traits that facilitated colonization of land.

Depression is one of the most common mental health disorders; researchers estimate over 264 million people worldwide have the disease. And, between 10-30 percent of people diagnosed with clinical depression are unable to find relief even after multiple rounds of treatment with antidepressants. 

To find a therapy for people diagnosed with treatment-resistant depression, researchers have been testing some unconventional drugs. These include the clinical anesthetic ketamine, as well as the active ingredient in magic mushrooms, psilocybin. Now, we can add laughing gas to the list.

A paper recently published in Science Translational Medicine reports results from a small, early-stage clinical trial conducted by researchers at the University of Chicago and Washington University School of Medicine. They found that inhaling a mixture of oxygen and nitrous oxide, the active chemical in laughing gas, significantly improved depression symptoms compared to inhaling oxygen alone in people diagnosed with treatment-resistant depression.

Larger studies will be necessary to validate these results. Nonetheless, early indications are that laughing gas may offer new hope for people diagnosed with treatment-resistant depression.

If you’ve ever lived with dogs, or raised a puppy, you’ve probably seen them excitedly sink their teeth into a stick. Traditionally, we’ve brushed it off as just another canine instinct or behavior, much like shooting us puppy dog eyes or licking themselves. But what if chewing on sticks is actually a sign of dogs’ intelligence?

For a long time, scientists assumed that just a handful of animals, including many primates and crows, used tools. In fact, tool use was seen as a marker of advanced evolution, a sign that we are smart enough to adapt our environment to our needs. A pair of researchers at Kyoto University want to include dogs among the ranks of toolmakers, and their findings have the potential to change how we think about animal intelligence.

James Brooks and Shinya Yamamoto carefully observed dogs chewing on sticks, and asked themselves why this behavior is so common. They posit that dogs purposefully use sticks to clean their teeth, and that stick chewing could relieve teething pain in puppies, much like we humans give our babies teething rings, and note that the way dogs hold their sticks in their paws suggests they’re potentially thinking through how to manipulate objects in space. This fits the definition of tool use.

Brooks and Yamamoto recommend further studies to see if dogs seek out sticks to chew on more often when they have other indicators of tooth pain or after different kinds of meals, and if more frequent stick-chewers have better dental health later in life. They also suggest we view tool use in animals as a spectrum, and their research raises questions about animal behaviors that might otherwise be overlooked as mere instinct. In other words, dogs and their sticks might just be showing us that animals are deliberate in their interactions with their environments.

Sunday July 11 was a landmark day in the history of space exploration. Sir Richard Branson and his civilian crew on Virgin Galactic flight Unity-22 reached 50 miles above the Earth’s surface, the border of space as defined by NASA, in a successful first flight. This flight ushers in the long-awaited dawn of space tourism, a venture to bring humans to space for recreational purposes. 

Launching from Branson’s specially-built Spaceport America in the deserts of New Mexico, the Virgin Galactic spacecraft is designed primarily with the passenger experience in mind. Whereas other launches take off vertically from the ground, Virgin Galactic’s flights start more like a commercial airline on a runway. This is meant to be more comfortable and less jarring for passengers. A carrier airplane, dubbed Eve after Branson’s mother, brings the rocket ship off the ground from this runway takeoff. 

Once at a high enough altitude, Eve releases the spacecraft Unity, which then fires its rocket engines to get to space. At the highest point in the flight, while the passengers are playing in zero gravity, Unity does a backflip, angling its windows towards Earth to provide them with spectacular views. In its descent, Unity acts like a glider, landing back on a runway, similar to how the NASA Space Shuttles landed. But if you’re hoping to take this flight, be aware that the price tag is pretty hefty: $250,000. 

Unity also carries a small science payload to test the concept of “human-tended payloads,” where investigators bring their science with them to space. Crew member Sirisha Bandla is operating an experiment to capture snapshots of plant chemistry during the transition into and out of microgravity.

Virgin Galactic, founded in 2004, is one of a group of billionaire-led endeavors into spaceflight that have been in development for decades. While Elon Musk’s SpaceX has focused more on interplanetary travel, Blue Origin (founded by Amazon's Jeff Bezos) is currently Virgin Galactic’s main space tourism competitor. In fact, Branson even moved up this Virgin Galactic launch date in order to beat Bezos into space, a billionaire space race that has been criticized by many. 

Branson’s dream of making space accessible is an admirable goal, the stuff of sci-fi stories. Although space isn’t yet available for everyone, today’s events are a first step towards that dream.

One of the perks of having a window seat in an airplane at night is looking out at the lights below. All that bright light underneath is actually a form of light pollution, or excessive artificial light. Like other forms of pollution, light pollution impacts both terrestrial and aquatic ecosystems. In fact, as of 2010, over 20 percent of Earth's coastlines were lit up artificially at night. As the human footprint on the planet continues to increase, the impact of light pollution on ecosystems remains a concern. 

A recent study sought to understand the impact of artificial light at night by studying long-term effects of light pollution on juvenile orange-fin anemonefish, Amphiprion chrysopterus, within coral reefs of French Polynesia. They raised wild-spawned fish in the lab, and released them either artificially lit coral reefs, or reefs under natural conditions, then monitored their survival for nearly two years. 

The researchers found that exposure to artificial light caused a 36 percent decrease in fish survival and growth, due to the increase of predators due to artificial light and its impact on fish physiology. This study highlights the need to further understand the impacts of light pollution on ecosystems, with the hope that solutions can be proposed in order to limit the impact of human activities on the natural ecosystems around us. 

Ants are a particularly numerous group of animals — there are approximately 13,000 named species of ants in the world — and they can be found almost everywhere. 

Their evolutionary success is frequently attributed to their division of labor and cooperation during foraging. Ant queens and males are mainly involved in reproduction and have wings, while ant workers are generally wingless and are adapted to ground labor. Ant workers show an almost Herculean strength; the Asian weaver ant can lift up to 100 times its body weight. 

A team of researchers wanted to understand the morphological reason for this strength. A previous study on the anatomy of queens and workers from different species of ants found that worker ants' thoraxes (the part of their bodies between the neck and abdomen) have larger muscles on the first thoracic segment than queens, making their necks stronger and more mobile. 

Now, their new study using high resolution X-ray analysis discovered specific changes in their thorax that are different from other flightless insects. The muscles involved in the movement of worker ants' necks, legs, and abdomens are stronger and have more support points — allowing them to carry heavy weights on their head while walking and running and to move their sting with precision. Such enormous strength may help explain their ecological success, despite the fact that they can't fly. 

In early June, NASA released new images from the Juno spacecraft, showing the first close-up of Ganymede, Jupiter's largest moon, since the Galileo spacecraft visited two decades ago. 

The Juno mission to Jupiter has been circling our solar system’s largest planet since 2016, taking images of the planet's magnificent swirls. It’s already observed so much about Jupiter: lightning in the clouds, movement deep in the atmosphere, and giant aurorae similar to the famous Aurora Borealis here on Earth. Next, it’s setting its sights on Ganymede.

Although Mars may seem like the most popular target to search for life, outer solar system moons like Ganymede have quite a bit of potential, too. These icy moons (including Ganymede, Europa, and Enceladus) likely have oceans of water underneath an icy outer shell. Ganymede in particular has a thick ice shell with chunks of rock embedded in it and bright streaks across the surface, making it an interesting and active place for astronomers to study. Ganymede is also the only moon that we know has a magnetic field — an important protective shield for life.

These new images of Ganymede show the most detailed view of the moon's surface yet. Scientists hope that information from Juno will tell us more about how thick the ice shell is, what it’s made of, and how much radiation is hitting the surface—all important things for understanding the moon’s habitability, and for planning future missions.

It would be inconvenient if we couldn’t remember the people we have or haven’t met before. Social recognition, the ability to differentiate familiar or novel individuals of the same species is part of a larger process of social memory that allows groups within a species to build and maintain stable networks or relationships, like what we know as friend groups or communities.

The hippocampus, known for its role in memory, is divided into subregions that contribute to different memory processes, and one called CA2 is particularly important for social memory. Scientists have found one particular neurochemical to be important in social recognition. Enkephalin, a neuropeptide that interacts with opioid receptors, is needed in CA2 to recognize new people.

Enkephalins belong to a class of opioids produced by the brain which are often associated with stress response and pain relief. The researchers found that in CA2, these compounds are released by specific type of neuron, boosting information transfer to the CA2, thus enabling our brains to form social memories.

Scientists studied the effects of enkephalin through a social memory test in mice. They introduced one mouse to a space with two others, and the subject mouse was allowed to interact with each mouse for fiver minutes. The subject mouse was removed, then returned half an hour later, this time with one of the mice from the last entry and one mouse it had not met before. The typical response for mice in this case is to pay attention to the new mouse for longer. The scientists observed that, while mice with regular enkephalin levels sniffed out the new mouse for a longer amount of time, mice without enkephalin spent the same amount of time between both mice, as if they had not previously encountered one of them.

A better understanding of social memory can help demystify related diseases. Schizophrenia, a condition in which social memory is impaired, is treated with drugs affecting opioid receptors, for example. The results of this study shed light on how these treatments work.