Many of us are familiar with the itchiness that can accompany an allergic response, along with the urge to scratch when we know we shouldn’t. Scientists are now one step closer to understanding what triggers such allergic responses.
Dendritic cells (DCs) are white blood cells that patrol the body on the look-out for foreign antigens that might pose a threat. Upon detecting a potential threat — sometimes a harmless allergen — certain DCs in the skin can become activated and migrate to the lymph nodes where they interact with T cells in order to initiate an allergic immune response.
DCs can detect potential invaders using receptors on their surface. However, in a paper recently published in Immunity, researchers from Massachusetts General Hospital and Harvard Medical School found that allergy-initiating DCs isolated from mice did not become activated in response to model allergens, suggesting there must be other factors required for their activation and subsequent migration in living systems.
Suspecting that the culprit was sensory neurons in close proximity to these DCs in the skin, the researchers injected mice with a chemical that blocks the function of sensory neurons and found that it prevented an allergic response. Furthermore, they showed that certain sensory neurons release a neuropeptide called Substance P in response to allergens. And when Substance P was injected into mice, it caused DCs to move to their lymph nodes, leading to an allergic response.
Not only does this finding highlight the importance of looking at immune responses both in isolation and within living organisms, the discovery of the role of sensory neurons and Substance P in allergic responses identifies a potential target for allergy medications.
Dark matter makes up almost 30% of our universe, yet we still aren’t sure exactly what it is. One suggestion is that dark matter is made up of primordial black holes (PBHs), black holes formed in the very early universe.
Usually, we think of black holes as forming from the deaths of the largest stars — but these PBHs had to be created before stars existed in the universe. A new model from researchers at UCLA shows a way that PBHs could have formed so that they explain all the dark matter observed in the universe.
This model builds on the Standard Model of particle physics, which describes how different particles and forces are related to each other, by adding only one additional term to its equations. In the early universe, particles coalesced together into massive halos, which could possibly collapse to make PBHs. The problem, though, is that in order for these halos to collapse, they’d need to get rid of some of their energy. This updated model describes a way for halos to radiate away that energy, meaning PBHs are, indeed, possible.
The model suggests that if PBHs are small, they could be abundant enough to explain all the mass of dark matter we see. If PBHs are large, they might not be able to explain all of dark matter, but they could still explain a fraction of it and even be detected by LIGO, the Laser Interferometer Gravitational Wave Observatory — meaning we could someday have concrete evidence for them.
Disclaimer: This research is by one of the author's colleagues.
Projecting film onto the ceiling of an indoor tent is a fun summer evening activity. It was also a laboratory setup at Johns Hopkins in the 1960s. What’s more exciting is that this setup led to a body of work that netted the tent-pitchers a Nobel Prize. Their finding in the tent is taught in all introductory neurobiology textbooks - the existence of cells sensitive only to particularly oriented lines. And it was all an accidental discovery that took place under these covers.
These experiments began with a cafeteria meeting in 1959, where David H. Hubel met Stephen Kuffler and Torsten Wiesel. After confirming their interests in studying visual information processing in a superficial layer of the brain (the cortex), Hubel and Weisel set up their tents in Kuffler’s laboratory.
Their experiments involved cats looking at the ceiling of this small indoor “circus arena,” where dark or light dots were projected while monitoring the activity of a single neuron. Their goal was simple: to understand what visual pattern activated these neurons. They used dots, drawn on glass slides to make the projection equipment work, since they knew they reliably stimulated retinal cells in the cats' eyes. After weeks of experiments, with various mishaps including accidentally spraying themselves with formalin (similar to formaldehyde), they triggered an avalanche of neuronal activity.
Next to the projected dots was a shadow line cast from the edge of the glass slide the dots were drawn on. This line, an accidental stimulus rising from imprecise slide placement, revealed the existence of orientation sensitive cells, or cells that respond only to lines in certain angles, also sometimes called “simple cells.” Soon, they also found “complex cells,” neurons that responded to lines moving in a particular direction or having directional selectivity. (Their use of “simple” and “complex” highlight the increase in information processing as information passes through the brain, as simple cells are thought to send information to complex cells.)
Hubel and Wisel paved the path for studying how the brain processes information. Their names and their work are revered in neurobiology, but their laboratory adventures and beneficial mishaps are less often remembered.
Dating back to the drawings of Ramon y Cajal, neuroscientists have always been fascinated with the striking shapes of neurons. Today, scientists still rely heavily on microscopy—albeit with instruments far more advanced than those in 1900—in hopes of understanding how neurons work by visualizing these fantastic cells. As new imaging techniques and approaches develop, we are able to learn more and more about neurons and the brain as a whole.
The beautiful shape of a neuron is intrinsically linked to its function. If the branched dendrite of one neuron contacts the long slim axon of another neuron, a connection (synapse) may form between them. When a neuron is stimulated, little packets of neurotransmitters called vesicles are released at the synapse. Then, the neurotransmitters are taken up by the second neuron, affecting its own activity.
This process occurs continuously in the billions of neurons and trillions of synapses that make up the human brain. With these astounding numbers, how can scientists zoom in and understand how specific neurons function, let alone specific synapses?
A new study published in Nature used a trio of impressive techniques to help answer this question. By optimizing a combination of light microscopy, electrophysiology, and electron microscopy, the researchers were able to measure the activity and image the ultra-structure of synapses in a mouse brain.
They observed numerous instances of axons and dendrites from different neurons touching, suggesting synapses were at these contact sites. However, when they took ultra-structure images of these neurons by electron microscopy, they noted synapses only formed at a percentage of the contact sites.
In examining the synapses that did form, the researchers made two novel observations. First, they showed that the size of synapse correlated with the electrical activity of the neuron. They also determined numerous vesicles could be released at the synapse simultaneously, contradicting the previous belief that only one vesicle was released at a time.
This combination of various methodologies to study the same synapse opens the door for future work to further probe the relationship between neuronal structure and activity, ultimately helping the scientific community better understand how synapses form and are regulated.
Proteins are the fundamental components of virtually everything occurring within our bodies – but what happens when the machines that make proteins become defective?
These protein-making machines are called ribosomes and mutations in ribosomes are connected to a group of human disorders called ribosomopathies. However, it remains unclear, at a cellular level, why defects in ribosomes cause problems in our bodies. This is where the use of model organisms such as fruit flies for research purposes is particularly valuable.
In a recent study, scientists used the fruit fly as a model to study the cellular basis of ribosomapathy. The scientists introduced a mutation previously reported from a human patient into the fruit fly ribosome. The resulting flies were developmentally delayed, and had much shorter hairs than normal.
In looking at the fruit fly cells, the researchers found that proteins that were not produced properly built up and formed aggregates. Proteins have to be folded into the correct 3D structure to perform their functions; and cells have an in-built system to remove any misfolded protein. But when ribosomes cannot operate normally due to a mutation, defective ribosomal products build up and can place an unusually large burden on the cell’s protein degradation system – a phenomenon called proteotoxic stress.
This finding opens up promising avenues for future therapeutics. The scientists proposed that this proteotoxic stress can be relieved by boosting the removal of toxic waste from cells (a process called autophagy), as well as combining with treatments that enhance protein production quality. Similar interventions have already been considered for diseases that involve protein aggregates, such as Alzheimer’s disease and Huntington’s disease.
Disclaimer: This paper was performed in the author's current lab group, but they were not involved in the research.
MC Hammer recently brought the hammer down on those who see science and philosophy as fundamentally opposed disciplines. He first tweeted a link to this paper, showing that STEM fields account for 21.3% of citations of philosophy of science journals. Some tweeters responded with unflattering, and inaccurate, characterizations of philosophy that put it at odds with science. In response, MC Hammer had some words of advice praised by scientists and philosophers alike: "It's not science vs Philosophy ... It's Science + Philosophy. Elevate your Thinking and Consciousness. When you measure include the measurer."
MC Hammer's insistence on the complementary nature of science and philosophy is in line with this 2019 opinion paper, published in PNAS. The authors described a continuum of science and philosophy, as the two fields share "the tools of logic, conceptual analysis, and rigorous argumentation.” They also provided three concrete examples of how philosophy helped scientific research in the life sciences and concluded with six practical proposals to encourage collaboration between scientists and philosophers.
Tweets by MC Hammer promoting these views will hopefully also help to break down harmful stereotypes of the disciplines that might prevent scientists and philosophers from working together for the good of society.
Self-care is a term that has gained immense momentum in the past year, in an era where most people have been stripped of their previous coping mechanisms and left to explore new ways to handle stress. Hearing this mantra may conjure up images of a face mask treatment, yoga sessions, or movie marathon, but in reality it is much more complex.
Although self-care boasts a history of blurry definitions in the past, the term actually grew out of the nursing field and a model called Orem’s Self Care Model. It encompasses both the intent and knowledge to care for one’s health, as well as the activities performed to accomplish this goal. A current model called the Seven Pillars of Self-Care framework categorizes self-care activities such as physical activity, healthy eating, and good hygiene.
Yet, self-care remains difficult to quantify. Pre-existing studies and frameworks have failed to provide an effective way to screen self-care activities, both in and outside of COVID-19 times. Developing this screening would help identify who is most likely to do self-care, and the activities they engage it. It is of utmost importance in an era where mental health issues and lack of holistic health care are as widespread as the virus itself.
In their pursuit to test existing screenings to develop an improved self-care screening method, a research team in Spain has developed a survey called the Self-care Activities Screening Scale (SASS-14) to measure self-care activities among Spanish-speaking populations during COVID-19. Because their survey is specific to the pandemic, they were able to recommend that screening for self-care during periods of extended lockdown should focus on physical care, nutrition, sleep, and emotional health.
As a result of this research, the SASS-14 is available as an online tool for healthcare workers to use to monitor how people are taking care of themselves during the extended lockdowns and lack of social contact that we are all experiencing.
Last week, NASA’s Perseverance rover safely landed on Mars. In the days since, the science team has been checking the rover’s systems to make sure it is working and ready to explore, and they’ve also received Perseverance’s first images of the Martian surface. Even cooler, they recently released the first sounds (ever!) from Mars and the first video of a spacecraft landing on the red planet.
Unlike earlier Mars missions (Sojourner, Spirit and Opportunity), which landed on giant airbags, Perseverance and its predecessor Curiosity landed using a “sky crane” system, where a rocket-powered crane gently lowers the rover down to the surface. The Mars Reconnaissance Orbiter (MRO) also captured a bird’s eye view of the landing, plus where all the various descent stages (heat shield, parachute/back shell, and sky crane) ended up across the surface.
Perseverance and its landing gear were uniquely equipped with a microphone and six cameras to capture the various angles of the entry, descent, and landing process. In the incredible video of Perseverance’s landing, you can see the parachute launched by a small explosive, the first step in slowing down the spacecraft. This parachute had a hidden easter egg from the engineering team, too—its color pattern reveals the JPL motto, “Dare Mighty Things.” After the parachute deployed, the spacecraft gently rocked back and forth until the back shell separated and the sky crane's engines kicked in, steering the rover toward its landing spot.
The rover approached the surface, obscured by dust kicked up from the sky crane’s rockets. Once it touched down, the last frames of the video reveal the sky crane cutting the wires attaching it to the rover, then flying away to land elsewhere on Mars, safely away from the rover. Post-landing, Perseverance’s microphone captured the sound of a gusty wind accompanied by the constant buzz of the rover itself.
So, what comes next for Perseverance? The mission team will continue checking out the hardware to make sure all systems are working properly, and will soon take the rover for its first drive on the Martian surface. It landed near a variety of different geologic features scientists are eager to explore, including an ancient river delta already spotted in Mastcam-Z’s incredible panorama. (Note: The “Z” is for zoom, so we can certainly expect more stunning photos.) There’s so much exciting science to come as Perseverance explores Mars looking for signs of life!
Humans are diurnal – we are active during the day and sleep at night. Our circadian rhythms are in sync with the sun, the strongest source of light on the planet. However, recent evidence suggests that moonlight may also influence our sleeping patterns, and this effect changes with the lunar cycle.
"We hypothesize that the patterns we observed are an innate adaptation that allowed our ancestors to take advantage of this natural source of evening light that occurred at a specific time during the lunar cycle," said Leandro Casiraghi, lead author of a new study, published in Science Advances.
The research, a collaboration between the University of Washington, Yale University, and the National University of Quilmes in Argentina, assessed the activity patterns of 562 participants across an urban-rural gradient. Participants included members of three Indigenous Toba/Qom communities in Argentina and undergraduate students from the University of Washington. Each participant slept with a wristwatch that tracked their movement and sleep. This data was combined with NASA's sun and moon data for each location.
The researchers found that the time the participants went to sleep and how long they slept oscillated during the course of the lunar cycle. On nights leading up to a full moon, when the moon was brighter, people went to sleep later and slept for a shorter time.
The researchers concluded that moonlight stimulates nocturnal activity, especially for those in rural communities where light pollution is sparse. People in cities, with greater light pollution, went to sleep later and slept for less time in general, but still followed similar patterns to people living with little or no access to artificial light. The researchers state that the artificial light present in cities mimics the effect that moonlight has on sleep for rural communities.
So next time you are having trouble falling asleep, you may want to look to the moon for an explanation.
There are many organisms such as spiders, lizards, and even starfishes (and many more) who voluntarily shed or detach a body part, also known as autotomy. They do so for several reasons. For example, autotomy is an escape strategy (for instance, if a leg is trapped between two rocks). It can also be a distraction for predators — an amputated tail wriggles, and makes a predator look one way while the tail shedder runs the other. Sometimes organisms self-amputate wounded limbs.
In a nutshell, autotomy enhances survival. However, it may also impose some costs.
Recently, scientists tested if this survival strategy incurs any reproductive costs in a scorpion species, Ananteris balzani. The scorpion sheds its tail permanently, causing the loss of the anus and a lifelong inability to poop. Male scorpions also use their tails during mating.
However, the researchers showed that tail loss has no effect on male mating success when compared to males with a tail. Remarkably, a tail-less female had less of babies than females with tails. This interesting finding suggests that the negative effect of “taillessness” is sex-dependent, and in these scorpions it is the females that pay the cost.
The US residential power supply system is messed up at all times, but Texas's power supply is particularly problematic right now. And worse, it's about to be crushing financially for millions of families impacted by winter weather, especially the families that are poor, or elderly, or not white (or all three).
Because many states have deregulated their power markets, a lot of people get their power through retail energy suppliers. These companies are, essentially, energy arbitrage firms. They spend a lot of time and money analyzing weather and usage and production to decide how much power to buy for their customers, and how much to charge for that power. They usually make sure that their costs are significantly below the rate they offer customers — that's how they make money. Except for when something unexpected happens, like an extreme weather event.
Right now, for a lot of reasons, energy providers don't have access to a lot of power to purchase, and the massive winter demand coupled with huge supply problems are causing the wholesale price of power to skyrocket from $50 per megawatt-hour to over $9,000 per megawatt-hour.
But these retail energy suppliers still need to make money, so how do they make up this ginormous deficit? They charge people more for the power! They might be able to legally add a surcharge to your bill in some areas, or they might adjust rates next year. The easiest thing to do, though, is just charge people more - and the consumers they can charge more are the consumers with variable-rate plans (VRP).
There can be a lot of good reasons to choose a variable rate plan, but there are also a lot of bad reasons to choose (or be assigned) a VRP. Sometimes a VRP is all that's available to a consumer (they have bad credit, they can't afford to put a deposit down for a contract with a fixed rate), or it's assigned to a consumer. Much like credit card companies, if you miss a payment, energy suppliers can put you in the metaphorical penalty box by charging you interest on your overdue balance while also raising your rates - penalty plans are often variable rate plans.
Sometimes people end up with a VRP because of an information asymmetry — for example, when an elderly person signs up for a bad plan because it was incorrectly recommended or the first option offered, or when someone with limited English proficiency or literacy deficits doesn't understand their options.
After the 2014 polar vortex, households on VRPs experienced astronomical bills. In some areas, the cost of electricity jumped to $2 per kWh. For context, the average cost of residential electricity was In Chicago, one 72-year-old man reported that his monthly bill jumped from $81 to over $300.
That's why marginalized people are likely to be extra financially burdened by this storm. They are more likely than average to be on VRPs.
This winter weather is bad news for everyone - people are dying, people don't have power in frigid conditions. This weather crisis has the potential to be financially disastrous for families, on top of the costs of repairs from weather damage. Help these families by donating to charities that assist with paying heating and electric bills, demanding accountability from lawmakers and energy regulators, and taking steps to stop climate change so these storms don't get worse every year.
If you have power right now, you can help these households by trying not to use your power. Rationing is effective against blackouts, but it also helps drive down demand, and thus cost.
Natural light is thought to be one of essential environmental factors dictating the ways animals live their lives. In aquatic animals, like coral larvae, the intensity and color of the light can be a crucial factor associated with swimming and moving behavior.
A new research study by a team of Japanese researchers, published in Scientific Reports, has explained how Acropora tenuis (a common reef coral) larvae move through the deep sea in response to the light intensity and color.
Coral larvae are the free-moving life stage of corals, and they build colonies of the things that we think of as reef corals. The researchers found that these coral larvae swim slower in deeper water where there is less light, and that blue light is a particularly important cue for swimming. This is remarkable, since larvae lack eyes, yet they can still sense light intensity and color. The researchers suggest that this behavior could help the larvae locate habitat with the bright and blue wavelengths of light they need as adults.
This behavioral phenomenon in coral larvae provides a more fundamental understanding of the early phases of larval settlement coral reefs in the natural environment.
In what is perhaps the most "2020" study, a group of researchers from the United States and Denmark (with the help of community scientist-bakers across the globe) have studied the biodiversity contained within 500 sourdough starters. Their research was recently published in the journal eLife.
The researchers collected 500 sourdough starters. These came mainly from the United States and Europe, but also included contributions from New Zealand, Thailand, and Australia.
All 500 sourdough samples were DNA-sequenced to determine their microbial makeup. They then took 40 samples that represented the range of diversity and tested them for aroma profiling, chemical analysis, and rising speed. They discovered that an until-now overlooked component of microbial diversity, acetic acid bacteria, play a significant role in sourdough's aroma and rising speed.
As an observational study, the results do not give us a master recipe for exactly which microbes create which bread characteristics. But the study does show that the types of microbes in a sourdough started affects how it rises, smells, and bakes. If you are still pandemic-baking, rest assured that there is plenty more fun to be had in determining the exact role of the microbes found in sourdough.
Stories of sea serpents and other ocean-dwelling monsters are long-standing myths. Now, in research published in the journal Fish and Fisheries, one scientist has uncovered the culprit behind historical sea serpent sightings in the British Isles.
After parsing through over 200 reports of sea-serpent sightings made between 1809-2000, Robert France from Dalhousie University concluded that accounts of a “many-humped” monster lurking near the water's surface in the British Isles were actually early sightings of marine animals entangled in fishing gear.
France scoured sightings published in historical newspapers, scientific journals, natural history books, cryptozoology texts, and even legally sworn testimonials. While sightings varied substantially, there were some common threads: The sea-serpent body stretched for tens of meters in length (up to 100m), formed many coils or humps at the surface, and frequently had hair or whiskers. Many reports suggested the serpents were capable of moving rapidly or reported them thrashing at the surface of the water.
But France argues these descriptions conflict with all known (living and extinct) marine animals and can be more easily explained when considering the possibility of a marine animal pulling lines of rope and buoys behind them.
Today, the synthetic materials that impart strength and durability to fishing gear weave a tight cocoon around unfortunate animals tangled within their grasp. But before the advent of these materials, fishing gear was made of natural products that would have allowed for animals to move more freely while attached to fishing gear. Instead of succumbing to more instantaneous deaths we associate with entanglements today, animals may have simply carried their entrapment devices around with them until the natural materials eventually degraded.
Beyond solving an age-old mystery that has enchanted sea-goers, France points to a more insidious narrative: marine entanglements have long been a pervasive problem, plaguing the oceans far longer than scientists expected.
Human hearts are divided into two major parts: the right and left ventricles. In the history of research on heart function and failure, the left ventricle has received the majority of the attention while the right ventricle has been severely neglected, despite its reported functional abnormalities in an estimated 70 million people in the United States.
The right and left ventricles of our hearts work together as a pump for our bodies, but the right ventricle is different from the left ventricle in its anatomy and physiology. For example, the left ventricle wall is more muscular than the right ventricle wall, and the left ventricle can be described as a conical or bullet shape while the right ventricle is shaped like a crescent. These differences indicate that the understanding and treatment of conditions affecting the right ventricle require specific and distinct research on it.
However, a recent study of 510 hospitalized COVID-19 adult patients published in the Journal of the American College of Cardiology found that irregularities in the shape and structure of the right ventricle could predict COVID-19 mortality.
Right ventricle enlargement, called dilation, and dysfunction, observed from clinical transthoracic echocardiography (a non-invasive imaging technique using ultrasound), were reported from 35% and 15% of patients studied, respectively. Both dilation and dysfunction were associated with increased mortality risk. Taken together, the study suggests that right ventricle remodeling is a possible predictor of COVID-19 hospitalization and death.
Last year’s Black Lives Matter protests spurred a reckoning with the United States’ unjust history and ongoing systemic racism, and science is not exempt from this revolution.
The American Institute of Physics records show that 2.1 percent of all physics faculty are Black, and there are only 22 Black women with astronomy PhDs according to AAWiP (African American Women in Physics).
Inspired by these facts, everything happening in the U.S., and other movements like #BlackBirdersWeek and #BlackInIvory, Ashley Walker, an astrochemist from Chicago, started the #BlackInAstro movement last summer. Walker is the first ever astrochemist to earn a Bachelor's degree from Chicago State University and an intern at the NASA Goddard Space Flight Center. They’ve been highlighting the achievements of Black astronomers and space scientists and sharing their experiences of what it’s like to be Black in the field of astronomy.
Now headed into another year of #BlackInAstro, and the start of Black History Month, I checked in with Ashley Walker to hear her thoughts on how far the movement has come, and where it’s going next. Looking back on the growth of #BlackInAstro, she’s proud of “the Black space community coming together, as well as the tremendous amount of support that came with it. I will always be surprised that it was trending on Twitter.”
Although they’ve done so much in building this community of Black astronomers and educating allies, #BlackInAstro is nowhere near done. Walker is determined to “continue celebrating ourselves, the past, and the future, as well as seeing what effective change is coming out of #BlackInAstro in addition to so many years of people before us fighting for equality in space sciences. We wanted to have our seat at the table, so I created a table for ALL of us.”
Disclaimer: The author of this piece is a member of the Astrobites collaboration, which has previously worked with Ashley Walker on #BlackInAstro.
One of the most exciting things about space chemistry is that it gives us a glimpse of chemistry that is difficult to study — or might not even exist — on Earth. A well known example of this is the chemistry on Saturn's largest moon Titan, which is famous for its lakes of methane. Scientists think that this Saturnian satellite has a hydrocarbon cycle that is much like our water cycle on Earth.
Using data from NASA's Cassini mission, researchers found a mysterious chemical signature in ultraviolet imaging data collected during a flyby of Rhea. They concluded that the most likely contender for this chemical feature is hydrazine, a nitrogen-containing compound typically used in manufacturing on Earth. In fact, hydrazine is one of the compounds used as a propellant for the Cassini spacecraft!
After confirming that Cassini's thrusters were shut off during the flyby of Rhea, the researchers had to consider other possible sources for the hydrazine. On Earth, small amounts of hydrazine are produced naturally by some algae and tobacco plants, but any hydrazine on Rhea wouldn't come from anthropogenic or biological sources. It is also possible that hydrazine could form within the ice on the surface of Rhea, but the moon's thin atmosphere leaves molecules on its surface vulnerable to irradiation that breaks apart the molecules needed to form hydrazine.
The hydrazine could also come from Titan. Scientists don't yet know whether hydrazine could even form on Titan, but the moon's nitrogen-rich atmosphere makes it a promising factory for hydrazine and other similar molecules.
Unfortunately, Saturn and its moons are too far away to further investigate this chemistry any time soon. We might have to wait until NASA's planned Dragonfly mission takes us back Titan again so we can better understand the chemistry there, and perhaps on Rhea too.
The thought of losing DNA for survival sounds bizarre, but do this at different stages of their life. For example, the parasitic worm Ascaris, also called the roundworm, loses about of its DNA during their change to which are all of the other cells in the body.
They found that all 24 chromosomes of Ascaris germ cells harbor DNA breaks close to the . Although most of the DNA in and around the telomeres is lost, new telomeric DNA is attached back to somatic cells.
When they imaged the worm cells, they found broken DNA is densely packed inside of the nucleus by lipid membranes. This packed DNA was evicted out into the cytoplasm, where it was attacked by proteins deployed by the cells to eat waste cellular material (a process called ).
At this moment, it is still not clear why Ascaris cells put in all this extra work to get rid of DNA. One prediction is that Ascaris could get rid of DNA only necessary for germ cell function but not useful to somatic cells.
In 1968, physicist Neil Ashcroft predicted that pure hydrogen would condense under extreme pressure into a superconducting metal capable of surviving at room temperature. Not many believed him, but the possibility of room temperature superconductivity inspired a few intrepid researchers.
Attitudes changed in 2015 when physicist Mikhail Eremets discovered a compound of hydrogen and sulfur that was superconductive up to -70 oC (-94 oF) when extreme pressure was applied. The work inspired a wave of research on room-temperature superconductivity with hydrogen compounds.
In a recent study published in Nature, a group of physicists reported superconductivity at room temperature and extreme pressure by adding a third element — carbon — to Eremet’s original compound of hydrogen and sulfur. They chose to use carbon because its strong bonds could help keep a material together once the pressure is released as it does for diamond.
The researchers compressed their mix of elements between the microscopic tips of two pointy diamonds. The final result was a superconducting temperature of 15 oC (58 oF) at 267 gigapascals, the same pressure that you would experience if you traveled about three-fourths of the way to the center of the Earth.
While they knew the chemical elements that made up the superconductor, the extreme pressure prevented their probes from obtaining data on the material’s final molecular and crystal structure. Until these are determined, researchers will face difficulty developing models that explain the high superconducting temperature measured.
Since the new superconductor requires extreme pressure, it also currently lacks immediate practical applications. Yet, the study suggests that a variation could prove useful, sparking new enthusiasm among researchers. The fantasies of ultra-efficient energy generation, perfect energy storage, and lossless power transmission are much closer to reality.
Before the advent of antibiotics, an infected paper cut could be deadly. Now we can use antibiotics to treat bacterial meningitis, strep throat and even tuberculosis. However, unlike most antibiotic prescriptions, tuberculosis treatment requires a regime of three different antibiotics and takes between six months and a year. This type of prolonged exposure to antibiotics drives the development of antibiotic resistance.
Scientists do not completely understand why such an extended course is needed to treat tuberculosis. They do know, however, that antibiotics must enter all of the bacterially-infected cells in order to be effective. Therefore, if scientists could develop antibiotics that enter the host cells as efficiently as the bacteria does, this could shorten the course of treatment required - reducing the risk of antibiotic resistance developing.
Researchers at the Francis Crick Institute in the UK and the University of Western Australia tackled this problem by developing an imaging technique to see which infected lung cells the antibiotics could enter. The team infected mice with Mycobacterium tuberculosis and treated them with the antibiotic bedaquiline. They used a new microscopy method, called CLEIMiT (correlative light, electron, and ion microscopy in tissue), to identify the specific cells that the antibiotic was taken up by.
They found that bedaquiline was unable to enter all of the infected lung cells, meaning while some bacteria were being killed, others managed to evade the treatment. This could explain why such a long treatment regime for tuberculosis is required. CLEIMiT offers the possibility of characterizing current antibiotics that we use to assess their cell-specific uptake, as well as aiding the development of more efficient antibiotics. This will ultimately reduce the risk of the development of antibiotic resistance.
In 2018 two babies, Lulu and Nana, were born as the result of a procedure called heritable human genome editing (HHGE) done by Dr. He Jiankui from the Southern University of Science and Technology in China. The procedure was against Chinese regulations and raised serious ethical questions. Dr. Jiankui is now in prison.
As a result of their genomes being edited, Lulu and Nana could face serious health conditions. Lulu and Nana’s DNA was modified long before they were born, when they shared one single cell, so they are at risk of mosaicism. Mosaicism occurs when an organism has different genetic information in different cells, as opposed to having the same genetic information in every single cell.
Genetic abnormalities in an early embryo can be detected before being implanted in the mother through genetic testing, using biological samples from the outer layer of the embryo. These tests do not reflect the genetic information of the whole embryo, and the occurrence of undetected mosaicism could affect the results.
Recently a group of scientists showed the efficiency of a new, non-invasive preimplantation genetic testing. Researchers used a sample from the inner cavity of an early embryo instead of the outer layer. As a result, this test was more reliable for detecting mosaicism in the embryo. The development of this non-invasive genetic testing could help to detect genetic abnormalities in embryos in assisted reproduction procedures and to detect mosaicism in HHGE experiments.
However, just because this procedure can detect mosaicism does not mean that HHGE is safe or a good idea. Undesired and unwanted potentially dangerous changes performed with genome editing can be passed down to future generations, and significant, legitimate ethical concerns remain. Currently, the scientific community recommends not to perform genome editing intended for pregnancy, and to regulate such experiments.
Antibiotic resistant bacteria are a growing threat, causing deadly infections that cannot be cured by our standard antibiotics. The development of antibiotic resistant bacteria may be further fueled by strained resources, increased hospitalizations, and decreased surveillance during the SARS-CoV-2 pandemic.
With limited development of new drugs to treat resistant bacterial infections, new therapies are desperately needed to prevent the spread of these “superbugs”. To this end, researchers are looking to a natural predator of bacteria – bacteriophages. Bacteriophages or “phages” are viruses that specifically infect bacterial cells. Depending on the type of phage, this infection can ultimately kill the bacteria that usually resist antibiotic treatment. Though commercial therapies are not yet available, the use of phage therapy is a hot topic boasting thousands of studies and several famous success stories.
While phage therapy shows great promise in the fight against resistant bacteria, these superbugs are constantly adapting and can evolve quickly to even resist phage infections. Fortunately for us, this resistance often comes with a cost. Researchers at Monash University have found a way to leverage the trade-off made by a phage resistant bacteria to make it once again susceptible to antibiotics.
Antibiotic-resistant Acinetobacter baumannii (A. baumannii) is considered an “urgent threat” by the Centers for Disease Control and Prevention. Like many disease-causing bacteria, A. baumannii forms a sugary outer capsule that can protect the bacterial cell from antibiotics and make it deadlier. However, the researchers behind this new study discovered that A. baumannii's protective layer also serves as the entry point for phage.
When the team exposed different strains of A. baumannii to phages in the lab, the bacteria quickly developed phage resistance by shedding their outer capsule to lock out the viral invaders. While capsule-less bacteria were protected from phage infection, researchers found that the mutated strains of A. baumannii were also re-sensitized to several antibiotics. Through experiments where they infected mice with A. baumannii, they also discovered that decreased bacterial reproduction in a host is another trade-off for phage resistance. They concluded that phage therapy can be effective in treating this superbug infection.
The CDC notes that infections from A. baumannii most often occur in healthcare settings, and people at highest risk are those who are on breathing machines (ventilators), in intensive care units, or have prolonged hospital stays. With these situations currently all too common in hospitals full of COVID-19 patients, phage therapy may provide an option where other treatments fail.
Circadian clocks, molecular timekeepers that can synchronize to 24-hour day/night cycles and thus allow cells to adapt to daily rhythms, have been characterized and studied in multicellular organisms for centuries. Their existence in single-celled organisms, on the other hand, has been questioned. In the 1980s and 90s, circadian clocks were found to regulate gene expression in photosynthetic bacteria. But, what about in bacteria who don’t directly depend on the sun for food?
This question was answered in a recent study published in Science Advances. It identified a circadian clock in the non-photosynthetic bacterium Bacillus subtilis, which is often found in the human gut and in soil. The authors observed that biofilm-forming cultures of these bacteria could synchronize their gene expression activities to 24-hour light or temperature cycles.
A biofilm is a collection of microorganisms that are held together by a sticky extracellular matrix. Different different parts of the biofilm can take on specialized roles; in this way, bacteria in a biofilm act like cells in a tissue, displaying behavior similar to multicellular development. It is plausible that adaptation to daily rhythms is tied to biofilm formation or maintenance, but the exact function of this newly-discovered clock remain unclear. Time and further research will tell whether circadian clocks also play roles in bacteria that aren’t inclined to live in biofilms.
For years, bats in North America have been plagued by a deadly fungal disease called . Despite measures to stop its spread, this fungus has swept across the continent, and scientists are monitoring the surviving bat populations to see if they are better equipped to avoid getting sick in the future. Unfortunately, North American bats may be stuck in an " that keeps them returning to the very habitats where the fungus grows best.
According to a in the journal Nature Communications, little brown bats (Myotis lucifugus) in Michigan and Wisconsin choose to hibernate in roosts that stay above 8°C even when colder roosts are available. This is important because the fungal pathogen that causes white-nose syndrome grows best at 12-16°C, so hibernating in colder caves would protect bats from this deadly disease.
Conservation biologists expected that when white-nose syndrome tore through these populations, the warm-loving bats would die off, leaving only cold-loving survivors behind. And, as bats are , they could potentially learn to avoid warm roosts in order to stay alive.
However, when the researchers compared the habitat preferences of bat populations before and after the fungus arrived, they only found a minor shift in preference towards colder roosts. The researchers concluded that these little brown bats are not likely to either evolve or learn warmer roosting preferences quickly enough to protect them from the disease. Considering that these bats have evolved for millennia with the risk of wintertime freezing, it makes sense that their desire to seek out warm roosts is difficult to overcome.
While it may not be possible to change the bats’ behavior, it is possible to conserve natural roosting sites that are cold enough to protect them and to restore human-altered sites like mines and tunnels by that insulate them. These conservation measures will be increasingly important as both habitat degradation and climate change continue to worsen.
Community science plays a crucial role in entomology research. Scientists regularly use observations, collated on databases such as iNaturalist, and specimens collected by community members in their research.
A recent study by Erica Fischer and their co-authors has revealed that specimens of Lepidoptera (an order of insects that includes butterflies and moths) have mainly been collected the community, rather than entomologists working at universities or natural history museums. However, between 1998 and 2009, the number of collections decreased by over a half. At the same time, the number of observations submitted to online databases has exploded.
The increase in observations shows there is no lack of interest in butterflies and moths. So why are community scientists, as well as professionals, collecting less specimens?
The researchers suggest that the decline is partially caused by a lack of funding, as well as a decrease in students learning the skills needed to collect specimens. In addition, many insect collections are not easily accessible, as they are not digitized (here is an example of a digitized collection). Lastly, they point out that taking a photo of an butterfly is much easier and quicker than collecting a specimen, especially as most people have a camera in their phone, so community scientists opt for this method of ‘collecting’ animals more often.
Despite the increase in observations, the lack of physical insect specimens could become an issue for future research, as they provide a wealth of additional information. For example, DNA can be extracted, and the morphology and internal anatomy can be studied in detail on real specimens. This is why museum collections are so important.
Although anybody can be a community scientist and contribute to entomology research, don’t go out and catch any butterfly you see, as there may be laws about what you can and cannot collect. Instead, join your local entomology society for a field trip or attend a BioBlitz to learn more!