Spring irrigation can reduce summer heat wave events

Heat waves are becoming more extreme as climate change exacerbates, with susceptible locations experiencing more frequent, prolonged and higher intensity events. As such, they pose a hazard to agricultural practices that rely upon sufficient water to ensure sustainable food supplies.

Irrigation is used to help alleviate warm, dry climates by maintaining soil moisture levels to promote growth as well as exerting a cooling effect on the immediate local climate (within a few meters of the surface), but extracts freshwater from resources that may also be threatened by shrinkage with more evaporation in a warmer world.

New research, published in Geophysical Research Letters, has investigated the dampening effect irrigating land in spring can have on the intensity of summer heat waves by retaining higher soil moisture levels between seasons, known as soil moisture memory.

The researchers  analyzed models of root-zone soil moisture data from 1980 to 2018 and combined this with a forecasting model to simulate the effect of irrigation on extreme summer heat wave events from 2004 to 2018. They ran three tests, one with no irrigation, one with both spring and summer irrigation, and the last solely with spring irrigation.

The researchers found that spring irrigation reduced the intensity of summer heat waves by 0.29°C and 2.5 days, and when combined with summer irrigation this extends to a reduction of 1°C and 6.5 days. With the simulated regional means of extreme heat waves being temperatures of 35.8°C and lasting 21.7 days, the combined impact of spring and summer irrigation can have a significant effect, especially on the longevity of the event.

This research is important as it suggests applying a surplus of water in spring helps to alleviate water stress in the following summer months, and is less wasteful of water resources that evaporate more in summer (especially from the top 1 m of soil), while also supporting regions that experience an imbalance in precipitation through the year.

Though the intensity of extreme heat wave events may be reduced, these climatic challenges will persist in the future, so it is important to apply these results in water resource management and adaptation planning strategies.

Guoshuai Liu et al, Spring Irrigation Reduces the Frequency and Intensity of Summer Extreme Heat Events in the North China Plain, Geophysical Research Letters (2024). DOI: 10.1029/2023GL107094

Age-related changes in skin may contribute to melanoma metastases

Age-related changes that cause the skin to stiffen and become less elastic may also contribute to higher rates of metastatic skin cancer in older people, according to research by investigators.

 The study, published March 12 in Nature Aging, shows that increased stiffness in aging skin increases the release of a protein called ICAM1. Increased ICAM1 levels stimulate blood vessel growth in the tumor, helping it grow. It also makes the blood vessels "leaky," enabling tumor cells to escape and spread throughout the body more easily.

The discoveries might also lead to new approaches to treating other age-related cancers. Previous therapies targeting growth factors that contribute to angiogenesis have failed in many tumor types, including melanoma. But ICAM1 provides a promising new target.

Nature Aging (2024).

• Age-Related Lung Changes Provide Pathway for Metastatic Growth of D...
• Age is a primary determinant of melanoma treatment resistance, two ...

How invisible presences hijack the social counting brain in Parkinson's disease

If you had to estimate the number of people in a room, without counting them one by one, by nature you would overcount them. That's because—simply put from a Darwinian perspective of how we have evolved—it's better to overcount potentially harmful agents and predators than to underestimate them. This overcounting social behavior is shown to be true in humans as well as animals. It's certainly better to detect too many tigers (even if absent) during a jungle excursion than to miss a hungry one.

Now,  neuroscientists show that if you experience hallucinations, especially when related to an illness like Parkinson's disease, then you will overestimate the number of people in a room to a greater degree. They also show that if you have hallucinations but are asked to estimate the number of boxes in a room, which are inanimate control objects, then no extra overestimation occurs, shedding light on the social nature of this overcounting.

The results are published in Nature Communications.

The fact that patients of Parkinson's disease have a much higher over-estimation in counting people is mind-blowing because Parkinson's disease is classically viewed as a movement disorder.

This new work shows that Parkinson's may also be a perceptual disorder, especially of social stimuli, and that invisible presences in Parkinson's disease may impair even more the counting social brain.

The category of hallucinations investigated by the neuroscientists is called presence hallucinations, for which people report an invisible presence next to them, even though no one is there. Such hallucinations are considered to be minor compared to visual hallucinations, for instance. They may be experienced early on in patients with Parkinson's disease, sometimes even before diagnosis. Presence hallucinations are also a known early marker of cognitive decline in Parkinson's disease.

The results of the study support the idea that the invisible presence (and related brain mechanisms) are responsible for this overcounting of people. When presence hallucinations are experienced—either due to disease or induced artificially—this extra presence gets subconsciously translated into an over-estimation of the number of people we think we see. In essence, the invisible presence gets added in the counting process, but only in counting people.

Nature Communications (2024).

https://www.nature.com/articles/s41467-024-45912-w

Rainforest's next generation of trees threatened 30 years after logging

Rainforest seedlings are more likely to survive in natural forests than in places where logging has happened—even if tree restoration projects have taken place, new research shows. The work appears in Global Change Biology.

Scientists monitored over 5,000 seedlings for a year and a half in North Borneo.

They studied a landscape containing both natural forest and areas logged 30 years ago—some of which were recovering naturally, while some had been restored by methods including tree planting.

A drought had triggered "mast fruiting" across the region, with trees simultaneously dropping fruit en masse and new seedlings emerging.

At first, both natural forest and restored forest had similarly high numbers of seedlings, compared to naturally recovering forest—suggesting restoration activities enhanced fruit production.

But these benefits did not last: low seedling survival in the restored forest meant that by the end of the study, similarly low numbers of seedlings remained in restored and naturally recovering forest. Seedling populations remained higher in natural forest.

Together, these results show that regeneration may be challenged by different factors depending on the restoration approach—seed availability in naturally recovering sites and seedling survival in sites where planted trees have matured. These differences may have longer-term implications for how forests can deliver key ecosystem services such as carbon sequestration.

Bornean tropical forests recovering from logging at risk of regeneration failure Running Title: Seedling responses to logging and restoration., Global Change Biology (2024).

A coral superhighway in the Indian Ocean

New research has revealed that, despite being scattered across more than a million square kilometers, remote coral reefs across the Seychelles are closely related. Using genetic analyses and oceanographic modeling, researchers have demonstrated for the first time that a network of ocean currents scatter significant numbers of larvae between these distant islands, acting as a "coral superhighway."

This discovery is very important because a key factor in coral reef recovery is larval supply. Although corals have declined alarmingly across the world due to climate change and a number of other factors, actions can be taken at local and national scale to improve reef health and resilience.

These actions can be more effective when we better understand the connectivity between coral reefs, by—for instance—prioritizing conservation efforts around coral reefs that act as major larval sources to support regional reef resilience.

The researchers collaborated with a wide range of coral reef management organizations and the Seychelles government to collect coral samples from 19 different reef sites. A comprehensive genetic analysis revealed recent gene flow between all sample sites—possibly within just a few generations—suggesting that coral larvae may be frequently transferred between different populations. The results also hinted at the existence of a new cryptic species of the common bouldering coral, Porites lutea.

The genetic analyses were then coupled with oceanographic modeling, simulating the process of larval dispersal. These simulations allowed researchers to visualize the pathways coral larvae take to travel between reefs across the wider region, and determine the relative importance of physical larval dispersal versus other biological processes in setting coral connectivity.

This revealed that dispersal of coral larvae directly between reefs across the Seychelles is highly plausible. For example, coral larvae spawned at the remote Aldabra atoll could disperse westwards towards the east coast of Africa via the East African Coastal Current. From here, they would then travel north along the coast, with some potentially even reaching the South Equatorial Counter Current, which could bring them eastwards again back towards the Inner Islands of Seychelles.

While these long-distance dispersal events are possible, it is likely that much of the connectivity between remote islands across the Seychelles may be established through "stepping-stone" dispersal. This suggests that centrally located coral reefs in Seychelles, and possibly East Africa, may play an important role in linking the most remote islands.

Integration of population genetics with oceanographic models reveals strong connectivity among coral reefs across Seychelles, Scientific Reports (2024). DOI: 10.1038/s41598-024-55459-x

New research shows turbulent flows can be caused by minute triggers

We experience turbulence every day: a gust of wind, water gushing down a river, or mid-flight bumps on an airplane.

Although it may be easy to understand what causes some kinds of turbulence—a felled tree in a river or a bear splashing around for salmon—there is now evidence that a very small disturbance at the start can have dramatic effects later. Instead of a tree, think of a twig—or even the swerving motion of a molecule.

The butterfly effect

A butterfly flaps its wings in Brazil, which later causes a tornado in Texas. Although we may commonly use the phrase to denote the seeming interconnectedness of our own lives, the term "butterfly effect" is sometimes associated with chaos theory. Researchers said their work represents a more extreme version of the butterfly effect, first described by mathematician and meteorologist Edward Lorenz in 1969.

What researchers have learned is that in turbulent systems, a very small disturbance at one point will have an amplified effect at a finite point in the future, but through a mechanism that is faster than chaos.

Although the mathematical mechanism for this amplification, known as spontaneous stochasticity, was discovered about 25 years ago. The fact that the random motion of molecules, responsible for the everyday phenomenon of temperature, could generate spontaneous stochasticity was not known before this work.

Thinking back on the twig in the river, while you might notice a small disturbance where the water flows over the twig, you wouldn't expect it to create a great deal of turbulence (via eddies and swirls) downstream. Yet that is precisely what this new paper shows. The mechanism is known as spontaneous stochasticity, because the randomness arises even though the fluid motion was expected to be predictable.

Furthermore, it would be impossible to pinpoint the twig that had originally set the eddies and swirls in motion. In fact, there may be no disturbance in the water flow where the twig is located at all.

The research team's findings also showed that spontaneous stochasticity happens regardless of the initial disturbance. Whether it's a twig, a pebble, or a clod of dirt, the randomness you get on a large scale is the same. In other words, the randomness is intrinsic to the process.

Part 1

There exists a fundamental limit to what can be predicted with turbulence," according to researchers. "You see this with weather forecasts; there is always a fundamental source of randomness. The precise sense in which this unpredictability was inevitable wasn't fully understood before this work."

It's that randomness that makes it so hard to accurately predict the weather more than a few hours in advance. Meteorological stations sample weather in select locations, and computer simulations stitch them together, but without knowing the exact weather everywhere right now, it's hard to predict the exact weather everywhere in the future. This paper hints at the possibility that fundamental limits will always exist because randomness will always show up.

There may also be implications in astrophysics research. Scientists already understand that computer simulations of how galaxies are formed and how our universe evolved are sensitive to noise. Often, the behaviours of stars, planets, and galaxies cannot be easily explained and may be attributed to the kinds of microscopic noise that researchers have uncovered now.

Dmytro Bandak et al, Spontaneous Stochasticity Amplifies Even Thermal Noise to the Largest Scales of Turbulence in a Few Eddy Turnover Times, Physical Review Letters (2024). DOI: 10.1103/PhysRevLett.132.104002. On arXiv: DOI: 10.48550/arxiv.2401.13881

Part 2

Jets release heat, water vapour, and particulate matter that can produce thin clouds in the sky, known as “contrails”. When numerous flights pass through some areas, these contrails can form clouds that absorb radiation escaping from the surface, acting as blankets floating above the Earth.

Study finds rerouting of airplanes to reduce contrails not as expensive as thought

A small team of environmental scientists has found via simulations that rerouting commercial airplanes to reduce contrails would be less expensive than previously thought. In their study, published in the journal Environmental Research: Infrastructure and Sustainability, the group used data from prior studies to create simulations of airplanes routed to prevent the development of contrails.

Prior research has shown that high-altitude airplanes are disproportionate contributors to climate change due to the multiple ways they impact the environment. In addition to the greenhouse gases they emit, jets that fly at high altitudes can also create contrails, white vapor trails of ice, water vapour and particulate matter.

When several planes fly in the same general area over the same period of time, the contrails can combine, leading to the formation of cirrus clouds, which can act like a blanket, holding in heat. Prior research has shown that this accounts for approximately 35% of the total aviation contribution to global warming.

Prior research has also shown that just 2%–10% of flights create approximately 80% of contrails. And because rerouting of jet planes can prevent the creation of contrails, researchers have suggested that the commercial aviation industry could greatly reduce its environmental footprint by doing so. But some argue that doing so would be too expensive to justify its cost.

To find out if that might be the case, American Airlines, working with another team of researchers last summer, used weather and satellite data to create software models and AI prediction tools to determine whether it was feasible to divert planes from airspace that would lead to contrail formation. They found that it appeared possible to reduce contrail formation by approximately 54%.

In this new effort, the research team used the same data to create simulations of 85,000 high-altitude flights and found that reducing contrails by 73% would raise fuel costs by just 0.11% and overall operating costs by just 0.08%. They also noted that rerouting aircraft under such a scenario would only involve 14% of all flights.

 Alejandra Martin Frias et al, Feasibility of contrail avoidance in a commercial flight planning system: an operational analysis, Environmental Research: Infrastructure and Sustainability (2024). DOI: 10.1088/2634-4505/ad310c

Progesterone protects babies from preterm birth in women with a short cervix, research shows

Preterm birth, defined as birth prior to 37 weeks, remains a serious problem with far-reaching consequences. Approximately 13.5 million children worldwide are born preterm each year. Children who are born preterm are at higher risk for, both physical and developmental, lifelong complications. Preventing preterm birth is therefore a major priority.

At around 20 weeks of pregnancy women with a short cervix have an increased risk of preterm birth. Preventing preterm birth in pregnant women with a short cervix is a crucial step in protecting the health of the child. Research now shows that, in pregnant women with a short cervix around 20 weeks, progesterone is better than a cervical pessary at reducing the risk of severe preterm birth. This study was published in the BMJ.

This is an important improvement that can contribute to the reduction of preterm births and the associated complications, such as an increased risk of infant mortality and long-term health problems for the child.

Researchers investigated the best treatment for women with a cervical length shorter than 25 mm at the 20-week ultrasound scan. A total of 25 centers across the Netherlands participated in this study.

The results of this study show that progesterone is more effective than a pessary in reducing extreme preterm birth. This study underlines the importance of measuring the length of the cervix during the 20-week ultrasound scan and informing women with a cervix shorter than 25 mm about the possibility of treatment with progesterone. For women with a cervical length between 25 mm and 35 mm, there was no significant difference in the number of complications due to preterm birth between the group taking progesterone and the group using a pessary.

Cervical pessary versus vaginal progesterone in women with a singleton pregnancy, a short cervix, and no history of spontaneous preterm birth at less than 34 weeks' gestation: open label, multicentre, randomised, controlled trial, The BMJ (2024). DOI: 10.1136/bmj-2023-077033

Study finds no persistent cough in four out of five individuals with tuberculosis in Africa and Asia

More than 80% of patients with tuberculosis, the world's most deadly infection, do not have a persistent cough, despite this being seen as a key symptom of the disease. The infection is predominantly transmitted by coughing, but probably also through simply breathing.

Researchers analyzed data on more than 600,000 individuals in Africa and Asia and found that 82.8% of those with tuberculosis had no persistent cough and 62.5% had no cough at all. These results are published today in The Lancet Infectious Diseases.

The  results indicate the probable reason why, despite huge efforts to diagnose and treat the disease, the tuberculosis (TB) burden across Africa and Asia is hardly declining.

A persistent cough is often the entry point for a diagnosis, but if 80% of those with TB don't have one, then it means that a diagnosis will happen later, possibly after the infection has already been transmitted to many others, or not at all.

 Prevalence of subclinical pulmonary tuberculosis in adults in community settings: an individual participant data meta-analysis, The Lancet Infectious Diseases (2024). DOI: 10.1016/S1473-3099(24)00011-2

Sugar-coated gold nanoparticles can quickly eliminate bacterial infections, no antibiotics required

If left to their own devices, bacteria on our teeth or wounded skin can encase themselves in a slimy scaffolding, turning into what is called biofilm. Oral biofilms, also known as plaques, formed by bacteria such as Streptococcus mutans can cause significant tooth decay. Wound infections, which are commonly caused by Staphylococcus bacteria, can greatly delay the healing process. In either case, the densely packed network of proteins and carbohydrates within biofilms can prevent antibiotics from reaching microbes throughout the affected area.

But that isn't the extent of the issue posed by biofilms. Not only are they difficult to remove, but they are troublesome to discern in the first place.

These bacteria wreak havoc on our tissue and, being shielded from antibiotic medication by the slime, are difficult to dislodge. A new strategy may offer a simple way to break up the muck and destroy the bacteria.

This new research identified a solution to knock out both problems with one stone: gold.

Researchers have developed sugar-coated gold nanoparticles that they used to both image and destroy biofilms.

Gold is nontoxic and readily converts energy from light sources into heat, making it a prime candidate for photothermal therapy, a strategy that utilizes the heat from nanoparticles to kill nearby pathogens. In addition to generating heat, the nanoparticles emit detectable ultrasound waves in response to light, meaning that gold particles can be visualized using a technique called photoacoustic imaging.

In the new study, the authors encapsulated gold spheres within larger golden cage-shaped nanoparticles to optimize their response to light for both therapeutic and imaging purposes. To make the particles appealing to bacteria, they coated them in dextran, a carbohydrate that is a common building block of biofilms.

In a study published in the Journal of Clinical Investigation, the authors demonstrated the diagnostic and therapeutic potential of the nanoparticles on the teeth and wounded skin of rats and mice, eliminating the biofilms in as little as one minute and outperforming common antimicrobials. 

Part 1

With this platform, you can bust biofilms without surgically debriding infections, which can be necessary when using antibiotics. Plus, this method could treat patients if they are allergic to antibiotics or are infected by strains that are resistant to medication. The fact that this method is antibiotic-free is a huge bonus. 

The researchers assessed their strategy by applying the gold nanoparticles atop S. mutans-infected teeth from ex vivo rat jaws.

In a photoacoustic imaging test on the teeth, the nanoparticles emitted signals that came through loud and clear, allowing the team to see precisely where biofilms had taken up the dextran-coated particles on the teeth.

Then, to evaluate the particles' therapeutic effect, they irradiated the teeth with a laser. For comparison, they treated other infected teeth samples with the topical antiseptic chlorhexidine.

The team observed a stark contrast in the outcomes of the two treatments, with the photothermal therapy being nearly 100% effective at killing biofilms, while chlorhexidine did not significantly diminish the viability of bacteria.

The treatment method is especially fast for the oral infection.

Evaluations conducted on mice with open wounds in their skin, infected with Staphylococcus aureus, were similarly successful, as heat generated by nanoparticles greatly outperformed another antimicrobial agent called gentamicin. Here, the researchers also measured and noted a rise in temperature of 20°C localized to the biofilm, not causing any apparent damage to surrounding tissue.

 Maryam Hajfathalian et al, Theranostic gold-in-gold cage nanoparticles enable photothermal ablation and photoacoustic imaging in biofilm-associated infection models, Journal of Clinical Investigation (2023). DOI: 10.1172/JCI168485

Part 2

Astronauts experience 'space headaches'

Space travel and zero gravity can take a toll on the body. A new study has found that astronauts with no prior history of headaches may experience migraine and tension-type headaches during long-haul space flight, which includes more than 10 days in space. The study was published in Neurology.

Changes in gravity caused by space flight affect the function of many parts of the body, including the brain.

The vestibular system, which affects balance and posture, has to adapt to the conflict between the signals it is expecting to receive and the actual signals it receives in the absence of normal gravity. This can lead to space motion sickness in the first week, of which headache is the most frequently reported symptom. This new study shows that headaches also occur later in space flight and could be related to an increase in pressure within the skull.

The study involved 24 astronauts from the European Space Agency, the U.S. National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency. They were assigned to International Space Station expeditions for up to 26 weeks from November 2011 to June 2018.

Prior to the study, nine astronauts reported never having any headaches and three had a headache that interfered with daily activities in the last year. None of them had a history of recurrent headaches or had ever been diagnosed with migraine.

Of the total participants, 22 astronauts experienced one or more episodes of headache during a total of 3,596 days in space for all participants.

Part 1

Astronauts completed health screenings and a questionnaire about their headache history before the flight. During space flight, astronauts filled out a daily questionnaire for the first seven days and a weekly questionnaire each following week throughout their stay in the space station.

The astronauts reported 378 headaches in flight. Researchers found that 92% of astronauts experienced headaches during flight compared to just 38% of them experiencing headaches prior to flight.

Of the total headaches, 170, or 90%, were tension-type headache and 19, or 10%, were migraine.

Researchers also found that headaches were of a higher intensity and more likely to be migraine-like during the first week of space flight. During this time, 21 astronauts had one or more headaches for a total of 51 headaches. Of the 51 headaches, 39 were considered tension-type headaches and 12 were migraine-like or probable migraine.

In the three months after return to Earth, none of the astronauts reported any headaches.

This research does not prove that going into space causes headaches; it only shows an association. A limitation of the study was that astronauts  reported their own symptoms. 

https://www.neurology.org/doi/10.1212/WNL.0000000000209224

Researchers discover plant temperature sensor molecule: The Rain Tree folds its leaves in the rain

A research group led by Professor Minoru Ueda and Graduate Student Yuki Muraoka of the Graduate School of Science at Tohoku University announced that they have clarified the identity of temperature-sensitive ion channels in plants. Focusing on the phenomenon of the legume tree Samanea saman (also known as the Rain Tree), which folds its leaves when it rains, the researchers found that a decrease in leaf temperature triggers the folding movement. Aside from the temperature effect on leaf folding, the research group also found that the ion channel SPORK2, which is present in cells at the base of the leaf, functions as a sensor molecule to detect temperature changes. These findings are expected to lead to the elucidation of the temperature-sensing mechanism in plants and were published in the November 28 issue of the journal Current Biology.

Temperature sensing is an essential function of all living organisms. Animals, including humans, use so-called transient receptor potential (TRP) channel molecules to sense temperature. These channel molecules are ion channel proteins that transport ions across cell membranes. They also act as temperature-sensing molecules because their function changes in response to temperature variation. By contrast, plants do not have temperature-sensing molecules such as TRP channels. Therefore, the mechanism by which plants sense temperature has been a mystery.

In this study, the research group focused attention on the fact that S. saman, which performs nyctinasty by folding its leaves at night and opening them in the morning, also folds its leaves when it rains. According to another report in 2018, nyctinasty in S. saman is regulated by SPORK2, an ion channel found in cells at the base of the leaf. This time, the research group found that this leaf folding is also triggered by temperature changes. They also found that SPORK2, like the TRP channel, changes its ion transport activity in response to temperature. Genes similar to SPORK2 (orthologs: genes derived from a common ancestral gene through species divergence) are found in other plants aside from S. saman.

Ion channels are proteins that form holes in the cell membrane through which ions are allowed to pass. The TRP channel creates holes for sodium and calcium ions, whereas SPORK2 generates holes for potassium ions. The activities of SPORK2 orthologs in Arabidopsis thaliana were also examined and they were found to be temperature-sensitive ion channels.

Crop production has been severely affected by climate change. Shedding light on the mechanisms by which plants adapt to temperature changes is an urgent issue for stable food production.

https://www.cell.com/current-biology/abstract/S0960-9822(23)01458-6?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982223014586%3Fshowall%3Dtrue

Part 2

97% of sampled Antarctic seabirds found to have ingested microplastics

Anthropogenic plastic pollution is often experienced through evocative images of marine animals caught in floating debris, yet its reach is far more expansive. The polar regions of the Arctic and Antarctica are increasingly experiencing the impacts of plastic reaching floating ice and land, not solely as larger macroplastics (>5 cm), but as microplastics (0.1 µm—5 mm) and nanoplastics (<0.1 µm) that may be carried vast distances from their source or be ingested in more populated areas during seasonal migration.

A new review, published in Frontiers in Marine Science, has investigated the scale of this issue, particularly with respect to seabirds who call these glaciated regions home.

Across >1,100 samples, the researchers explored stomach contents, crop pouch near the throat for temporary food storage during foraging trips, guano (excrement mixture of food and metabolic waste) and regurgitated pellets of undigested food and other particles. Pellets formed the main component of the samples, followed by stomach contents and guano, while pouch contents were minimally present.

They found that 13 species of seabird inhabiting polar landscapes were reported to have ingested microplastics, including little auks, northern fulmars, glaucous gulls, thick-billed murres, white-chinned petrels, great shearwaters, sooty shearwaters, king penguins, Adélie penguins, chinstrap penguins, gentoo penguins, brown skuas and south polar skuas.

A total of 3,526 particles were extracted from these seabird samples, equating to at least 1 microplastic particle in 90% of Arctic samples and 97% for Antarctica. A median of 31.5 and 35, and average of 7.2 and 1.1, microplastic particles were found in each sample in the Arctic and Antarctica respectively. A maximum of 36 microplastic particles were found in a single bird.

Regarding plastic composition, 14 polymer types were identified, the dominant form being polyethylene, followed by polypropylene and polystyrene. These were predominantly present as fragments, derived from the breakdown of larger plastic objects. Such plastic polymer types can be sourced from items like plastic bags, food and drink containers and protective foam packaging.

The impact ingestion of plastic particles can have on seabirds includes blockage of their gastrointestinal tract, toxicity and oxidative stress, as well as triggering immune reactions. Additionally, it is not only direct ingestion of particles that is of concern, as microplastics have been found in krill, a food source for some penguins, highlighting the larger-scale issue in the ecosystem and trophic webs.

 Davide Taurozzi et al, Seabirds from the poles: microplastics pollution sentinels, Frontiers in Marine Science (2024). DOI: 10.3389/fmars.2024.1343617

 Researchers observe how energy of single electron is tuned by surrounding atoms

Physicists  have choreographed the shift of a quantized electronic energy level with atomic oscillations faster than a trillionth of a second.

Throwing a ball into the air, one can transfer arbitrary energy to the ball such that it flies higher or lower. One of the oddities of quantum physics is that particles, e.g., electrons, can often only take on quantized energy values—as if the ball was leaping between specific heights, like steps of a ladder, rather than flying continuously.

Qubits and quantum computers as well as light-emitting quantum dots make use of this principle. However, electronic energy levels can be shifted by collisions with other electrons or atoms. Processes in the quantum world usually take place on atomic scales and are also incredibly fast.

Using a novel type of ultrafast microscope, a team of physicists has now succeeded in directly observing with atomic resolution on ultrafast timescales how the energy of a single electron is tuned by the vibrations of the surrounding atoms. Remarkably, they were also able to specifically control this process. Such discoveries could be crucial for the development of super-fast quantum technologies.

The physicists used an atomically thin material to investigate how a discrete energy level changes when this atomic layer moves up and down like the membrane of a drum. They observed this at a vacancy—the void left behind when an individual atom is removed.

Such atomically thin two-dimensional crystals, known for their versatile, customizable electronic properties, are particularly interesting for future nanoelectronics. Vacancies in a crystal are promising candidates for qubits, the elementary information carriers of quantum computers, as they have discrete electronic energy levels just like atoms.

The researchers found that they can change a discrete energy level of the defect by triggering a drum-like vibration of the atomically thin membrane: the atomic motion of the surrounding atoms shifts and thus controls the energy level of the vacancy.

The work establishes a new era in the study of the dynamics of atomically localized energy levels and their interaction with the environment. This discovery enables the local control of discrete energy levels in the most direct way. For instance, the motion of individual atoms could change the energy structure of a material and thus create new functionalities or specifically change the properties of light-emitting semiconductors and molecules.

Carmen Roelcke et al, Ultrafast atomic-scale scanning tunnelling spectroscopy of a single vacancy in a monolayer crystal. Nature Photonics. www.nature.com/articles/s41566-024-01390-6

Researchers develop dual anti-tumour vaccine

a research team has discovered that exosomes derived from γδ-T cells not only have direct anti-tumor effects but also, when developed into a tumor vaccine, can effectively induce a tumor-specific immune response. The findings, which provide a new approach to cancer treatment, were published in the Journal of Extracellular Vesicles.

Exosomes are nanoscale particles secreted by cells, carrying various substances, such as lipids, proteins and nucleic acids, that play a crucial role in intercellular communication. Exosomes have been explored for developing tumor vaccines, as they can protect vaccine components from degradation, improve stability, extend the biological half-life, and enhance antigen uptake by antigen-presenting cells (APCs).

Previous studies focused on exosomes derived from tumor cells (TExos) and dendritic cells (DC-Exos) but found limitations in terms of safety and clinical efficacy.

In this study, the research team focused on exosomes derived from human γδ-T cells, a rare subset of T cells known for their direct anti-tumor activity and ability to enhance T-cell responses.

The research team discovered that γδ-T cell-derived exosomes (γδ-T-Exos) exhibited dual anti-tumor activities by carrying cytotoxic and immunostimulatory molecules that can directly kill tumor cells and stimulate the immune system.

They found that γδ-T-Exos has adjuvant effects, enhancing the expression of antigen-presenting and releasing molecules that promote inflammation, which improves the ability of the immune system to recognize and attack tumor cells.

Intriguingly, the research showed that vaccines based on allogeneic γδ-T-Exos (derived from different individuals) exhibited similar preventive and therapeutic effects as vaccines based on autologous γδ-T-Exos (derived from the same individual) in mouse models. This suggests that this approach is suitable for centralized and standardized production. The vaccines have dual anti-tumor capabilities in effectively killing tumor cells and indirectly inducing a T-cell-mediated anti-tumor immune response, leading to better tumor control than existing vaccine strategies.

Xiwei Wang et al, Tumor vaccine based on extracellular vesicles derived from γδ‐T cells exerts dual antitumor activities, Journal of Extracellular Vesicles (2023). DOI: 10.1002/jev2.12360

Scientists can now remove nanoplastics from your water with 94% efficiency

Researchers have created a new technology that can remove harmful nanoplastics from contaminated water with 94% efficiency. The study, "Utilization of epoxy thermoset waste to produce activated carbon for the remediation of nano-plastic contaminated wastewater," was published in the journal Separation and Purification Technology.

The amount of plastic pollution in our ecosystem has become an increasingly alarming concern globally. Concerns have frequently been flagged about the impact that plastic pollution has on the toxicity to the environment and humans.

The impact of nanoplastics, material that is a thousand times smaller than microplastics, has been found to have a significant detrimental effect on aquatic and human life. However, the options that can eliminate nanoplastics from oceans and lakes are limited.

A team of researchers, who specialize in polymer engineering, tackled a new method to address small plastic waste and remove nanoplastics from wastewater systems.

They used epoxy, a waste polymer that can't be reused or reprocessed and often ends up in landfills or finds its way into water system networks like lakes or streams.

Using a process called thermal decomposition, the researchers converted epoxy into activated carbon, a material capable of removing nanoplastics.

The researchers then used the activated carbon to treat water contaminated by nanoplastics after producing nanoplastics from polyethylene terephthalate, a form of polyester often used in plastic water bottles and clothing such as fleece.

These tiny contaminants pose a greater health risk compared to microplastics as they can penetrate cells and are hard to detect. The 94% removal efficiency of nanoplastics was achieved by physically trapping the nanoplastics in the porous structure of the waste plastic, which generated activated carbon.

Rachel Blanchard et al, Utilization of epoxy thermoset waste to produce activated carbon for the remediation of nano-plastic contaminated wastewater, Separation and Purification Technology (2023). DOI: 10.1016/j.seppur.2023.124755

Can you get electrocuted by an electric vehicle?

Electric cars, scooters and bikes are everywhere. Are they safe? An expert breaks down the safety of EV and lithium-ion batteries when they encounter water.

It is highly unlikely that a Tesla submerged in a pond in  fatal accident poses a threat of electrocution to its driver or rescuers.

Battery compartments in electric vehicles such as Tesla are completely sealed and well protected.

Most electric vehicles, according to the U.S. Department of Energy, like most portable consumer electronics such as smartphones and laptops as well as electric scooters and e-cigarettes are powered by lithium-ion batteries. Lithium-ion batteries store more energy per unit mass and volume and have a high power-to-weight ratio, high energy efficiency, good high-temperature performance, long life and low self-discharge.

The world needs to hear Paul’s incredible story for a few reasons:
This is what happens if you don't take vaccines
You can never kill a determined mind
How science can make a dying man live
A little help for a deserving human being doesn't make you less rich

The Man in the Iron Lung
Polio Survivor Who Lived in Iron Lung For 7 Decades Dies at 78

New research suggests that our universe has no dark matter

The current theoretical model for the composition of the universe is that it's made of normal matter, dark energy and dark matter. A new study challenges this.

A study, published recently in The Astrophysical Journal, challenges the current model of the universe by showing that, in fact, it has no room for dark matter.

In cosmology, the term "dark matter" describes all that appears not to interact with light or the electromagnetic field, or that can only be explained through gravitational force. We can't see it, nor do we know what it's made of, but it helps us understand how galaxies, planets and stars behave.

Physicists used a combination of the covarying coupling constants (CCC) and "tired light" (TL) theories (the CCC+TL model) to reach this conclusion.

This model combines two ideas—about how the forces of nature decrease over cosmic time and about light losing energy when it travels a long distance. It's been tested and has been shown to match up with several observations, such as about how galaxies are spread out and how light from the early universe has evolved.

This discovery challenges the prevailing understanding of the universe, which suggests that roughly 27% of it is composed of dark matter and less than 5% of ordinary matter, remaining being the dark energy.

Challenging the need for dark matter in the universe

The study's findings confirm the researchers' previous work (1) ("JWST early universe observations and ΛCDM cosmology") about the age of the universe being 26.7 billion years has allowed them to discover that the universe does not require dark matter to exist.

In standard cosmology, the accelerated expansion of the universe is said to be caused by dark energy but is in fact due to the weakening forces of nature as it expands, not due to dark energy.

"Redshifts" refer to when light is shifted toward the red part of the spectrum. The researcher analyzed data from recent papers on the distribution of galaxies at low redshifts and the angular size of the sound horizon in the literature at high redshift.

There are several papers that question the existence of dark matter, but this is the first one that eliminates its cosmological existence while being consistent with key cosmological observations that we have had time to confirm.

By challenging the need for dark matter in the universe and providing evidence for a new cosmological model, this study opens up new avenues for exploring the fundamental properties of the universe.

 Rajendra P. Gupta, Testing CCC+TL Cosmology with Observed Baryon Acoustic Oscillation Features, The Astrophysical Journal (2024). DOI: 10.3847/1538-4357/ad1bc6

Footnotes:

1.  R Gupta, JWST early Universe observations and ΛCDM cosmology, Monthly Notices of the Royal Astronomical Society (2023). DOI: 10.1093/mnras/stad2032

Researchers use moisture to pull carbon dioxide out of the air

A way to capture and release carbon dioxide from the atmosphere is by simply changing the surrounding humidity using a material.

The material could slash the energy costs associated with so-called direct air capture systems, which conventionally rely on energy-intensive temperature or pressure shifts to switch between carbon capture and release. By instead relying on humidity, the material could yield energy efficiency improvements over five times above current technologies. The researchers  report their findings in Environmental Science & Technology Letters.

Direct air capture systems have been heralded as a way to combat climate change by pulling carbon dioxide out of the air to either store permanently underground or convert into a useful product.

Despite its promise, direct air capture has come under scrutiny since it requires more energy to perform than almost any other application of carbon capture. That is because the concentration of carbon dioxide in ambient air is extremely diluted, especially when compared to the waste gas from a point-source emitter such as a coal-fired power plant. One of the process' most energy-intensive steps is regeneration. After capturing carbon dioxide from ambient air, conventional systems require heat and/or pressure changes to release the gas into storage so that the system can be prepared to capture more carbon. In one approach using a liquid solvent, the regeneration step requires heating the carbon capture material to temperatures ranging from 300° to 900°C. By contrast, previous research has shown that regenerating carbon capture materials with humidity only requires adding or removing water vapor. Such an approach dramatically cuts the energy required to remove a ton of carbon dioxide, from up to 4.1 gigajoules using conventional techniques to just 0.7 gigajoules—an energy savings per ton.

To achieve the humidity-based approach, the Princeton team modified an existing type of ion-exchange resin, a material that can trade charged particles with the surrounding environment. These resins are already used for a range of commercial purposes, making them widely available and inexpensive.
Moreover, the surfaces of these resins are dotted with countless tiny pores, only 6 nanometers in diameter. The carbon capture process takes place inside these cavities. At low humidity, a series of chemical reactions occurs in the pores that allows them to capture carbon dioxide from a stream of incoming air. At high humidity, the opposite occurs: the material releases its bound carbon and is prepared for another round of capture.

Part 1

We can simply change the amount of water vapour in the system to regenerate the entire material in this new process. In this way, we can minimize the energy we put into the process.

The researchers examined ways to control and modify the materials at the nano-scale to enable more efficient moisture-swing carbon capture. They found that loading the pores with highly basic, negatively charged ions such as phosphate and carbonate yielded the highest capacity for carbon capture.

Yaguang Zhu et al, Confinement Effects on Moisture-Swing Direct Air Capture, Environmental Science & Technology Letters (2024). DOI: 10.1021/acs.estlett.3c00712

Part 2

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More than 16,000 chemicals can be found in plastic, and many are harmful: Report

Researchers have found more than 16,000 chemicals in plastics. A new report shows that about a quarter of these chemicals can be hazardous to health and the environment.

Plastic pollution is an international environmental crisis, and the researchers behind a new report are becoming increasingly concerned about the health consequences of plastic. There are many problematic chemicals in plastics. They pose a threat to both human health and the environment. Therefore, we must make plastic safe and sustainable.

We can only deal with the plastic problem if we take the chemicals in the plastic into account, and manage them in a responsible manner.

The United Nations is in the process of negotiating a global treaty on plastics. The goal is to end plastic pollution and develop plastics that are safer and more sustainable. That makes it very important for decision makers to know as much as possible about the chemicals in plastics, and take them into account when making decisions.

The key findings of the new report:

• At least 4,200 plastic chemicals, approximately 26%, pose a health and/or environmental hazard.
• 400 of the chemicals that are of concern to the researchers are found in all types of plastics, including plastic food packaging. All plastics can leach hazardous chemicals.
• To make plastic materials safer, we need new methods to regulate the chemicals. This includes identifying the hazardous chemicals and regulating hazardous groups of plastic chemicals.

In addition to being a database of problematic substances, the document also provides a method for identifying and managing chemicals of concern in plastics.

Part 1

Plastic chemicals include all chemicals found in plastic, in addition to additives, impurities and chemicals that are used during production.

The advice of researchers:

The researchers have formulated four points that they believe decision-makers must address:

• Regulate the use of problematic substances in plastics.
• Create more transparency around which chemicals are used in plastic production.
• Make plastics less complicated so we don't have to deal with so many chemicals.
• Increase impact and capacity to make it easier for authorities, industry and researchers to work together to make better plastics.

The report will play a crucial role in tackling the problem of plastic pollution.

Martin Wagner et al, State of the science on plastic chemicals - Identifying and addressing chemicals and polymers of concern, Zenodo (2024). DOI: 10.5281/zenodo.10701706

Part 2

What Comes After 5G? Developing New Technologies to Enable 6G

Two artificial intelligences talk to each other

Performing a new task based solely on verbal or written instructions, and then describing it to others so that they can reproduce it, is a cornerstone of human communication that still resists artificial intelligence (AI).

A team from the University of Geneva (UNIGE) has succeeded in modeling an artificial neural network capable of this cognitive prowess. After learning and performing a series of basic tasks, this AI was able to provide a linguistic description of them to a "sister" AI, which in turn performed them. These promising results, especially for robotics, are  published in Nature Neuroscience.

Performing a new task without prior training, on the sole basis of verbal or written instructions, is a unique human ability. What's more, once we have learned the task, we are able to describe it so that another person can reproduce it. This dual capacity distinguishes us from other species which, to learn a new task, need numerous trials accompanied by positive or negative reinforcement signals, without being able to communicate it to their congeners.

A sub-field of artificial intelligence (AI)—Natural language processing—seeks to recreate this human faculty, with machines that understand and respond to vocal or textual data. This technique is based on artificial neural networks, inspired by our biological neurons and by the way they transmit electrical signals to one another in the brain. However, the neural calculations that would make it possible to achieve the cognitive feat described above are still poorly understood.

Currently, conversational agents using AI are capable of integrating linguistic information to produce text or an image. But, according to researchers, they are not yet capable of translating a verbal or written instruction into a sensorimotor action, and even less explaining it to another artificial intelligence so that it can reproduce it.

The researchers have now succeeded in developing an artificial neuronal model with this dual capacity, albeit with prior training.

This model opens new horizons for understanding the interaction between language and behaviour. It is particularly promising for the robotics sector, where the development of technologies that enable machines to talk to each other.

 Reidar Riveland et al, Natural language instructions induce compositional generalization in networks of neurons, Nature Neuroscience (2024). DOI: 10.1038/s41593-024-01607-5

Study shows glucose levels affect cognitive performance in people with type 1 diabetes differently

A new study  used advances in digital testing to demonstrate that naturally occurring glucose fluctuations impact cognitive function in people with type 1 diabetes (T1D).

Results of the study, published in npj Digital Medicine, show that cognition was slower in moments when glucose was atypical—that is, considerably higher or lower than someone's usual glucose level. However, some people were more susceptible to the cognitive effects of large glucose fluctuations than others.

In trying to understand how diabetes impacts the brain, this research shows that it is important to consider not only how people are similar, but also how they differ.

T1D is an autoimmune disease characterized by glucose variability. Previous laboratory studies have shown that very low and very high glucose levels impair cognitive function. However, technological limitations made it difficult to study the impact of naturally occurring glucose fluctuations on cognition outside of the laboratory, preventing researchers from obtaining repeated, high-frequency measurements within the same individuals over time. High-frequency measurements are necessary to understand whether glucose fluctuations impact cognition similarly for everyone.

In the new study, researchers used digital glucose sensors and smartphone-based cognitive tests to collect repeated, high-frequency glucose and cognitive data in 200 individuals with T1D. Glucose data were collected every five minutes and cognitive data were collected three times per day for fifteen days.

Collecting glucose and cognitive data unobtrusively, as participants went about their daily lives, allowed researchers to examine the cognitive impact of naturally occurring glucose variability. With many data points from each individual, they were able to use machine learning to test whether the impact of glucose on cognition differed from person to person.

The study showed that cognitive function was impaired when glucose was considerably higher or lower than usual, and this effect was observed for processing speed but not sustained attention. It is possible that processing speed is impacted by short-term, moment-to-moment fluctuations in glucose, whereas sustained attention is impacted by high or low glucose that persists over longer periods of time.

Part 1

The researchers also found that people differed from each other in terms of how much glucose fluctuations impacted their cognitive speed, and some people—including older adults and adults with certain health conditions—were much more impacted by glucose fluctuations than others.

These results demonstrate that people can differ a lot from one another in how their brains are impacted by glucose.

This work  found that minimizing glucose fluctuations in daily life is important for optimizing processing speed, and this is especially true for people who are older or have other diabetes-related health conditions.

One surprise discovery was that participants' peak cognitive performance coincided with glucose levels that were slightly above their normal range, though performance dropped off as glucose levels rose even further.

 Dynamic associations between glucose and ecological momentary cognition in Type 1 Diabetes, npj Digital Medicine (2024). DOI: 10.1038/s41746-024-01036-5 , www.nature.com/articles/s41746-024-01036-5

Part 2

People   assume babies’ brains are simply not mature enough to form lasting memories. This is called infantile amnesia.

In nerve cells, insulin regulates whether mitochondria are shut down or kept running

The hormone insulin controls many cellular processes and adapts them to the body's current energy supply. One of the insulin-regulated processes is the quality control of mitochondria in neurons, scientists have discovered.

When sufficient energy is available in the body, insulin facilitates the elimination of defective mitochondria. When energy is scarce or when the insulin signal is interrupted, mitochondrial recycling is reduced and cells continue to use their old power plants, even potentially damaged ones. The continued operation of faulty mitochondria could affect aging processes and neurological diseases.

Nerve cells place special demands on their energy supply. Due to their extensive branching and their high energy needs, they keep a close watch on their cellular power plants, the mitochondria. The cells have to ensure that there are always sufficient mitochondria available in their long extensions, the axons, where the power plants fuel the cell's communication with its neighboring cells. This is why neurons transport mitochondria even to the cells' most remote locations.

 Earlier research had shown that mitochondria carry along the blueprints of the PINK1 protein on their journey through the neuron.

PINK1 is a key protein that acts when mitochondria need to be removed because they are no longer functioning correctly. 

It can mark mitochondria for recycling and is precisely controlled by the cells." A failure to keep PINK1 in check could lead to a shortage of mitochondria, whereas the continued operation of defective cellular power plants can damage a cell.

Researchers have now uncovered that the hormone insulin is involved in mitochondrial quality control in neurons. Insulin is well-known for its role in regulating a cell's sugar uptake. It also controls many processes inside cells to precisely adjust them to the body's current energy supply.

Part 1

In the case of mitochondrial recycling, this works as follows: If sufficient energy is available, a signal is transmitted from the insulin receptor on the cell surface to the mitochondria. Here, PINK1 blueprints are stored as mRNA molecules. When the insulin signal arrives, the blueprints are released by the mitochondria and the cell can produce additional PINK1 protein. This ensures that defective mitochondria are efficiently eliminated. In case of an energy shortage, or if the insulin receptor signal is missing, the blueprints for PINK1 remain tightly bound to the mitochondria.

On the one hand, the tight binding to mitochondria allows the PINK1 blueprints to hitchhike far into the nerve cells' long extensions. On the other hand, it reduces the availability of mRNA molecules for PINK1 production. PINK1 protein levels remain low and mitochondrial recycling is reduced—even though this can lead to the continued operation of damaged power plants.

Interrupted signaling with implications for health and aging

A similar situation can occur when the transmission of signals from the insulin receptor to mitochondria is disturbed due to disease. Defective insulin signaling is a hallmark of diabetes and has also been observed in the brain in connection with Alzheimer's disease.

It is also known that inefficient mitochondrial quality control can contribute to various neurodegenerative diseases.

Insulin signaling regulates Pink1 mRNA localization via modulation of AMPK activity to support PINK1 function in neurons, Nature Metabolism (2024). DOI: 10.1038/s42255-024-01007-w

Part 2

Rank Country Global biodiversity index Global rank
1. Democratic Republic of Congo 214.43 16th
2. Tanzania 213.10 17th
3. South Africa 207.94 19th
4. Kenya 179.72 23rd
5. Cameroon 172.41 24th
6. Madagascar 162.29 26th
7. Angola 160.67 27th
8. Guinea 153.43 30th
9. Mozambique 144.30 31st
10. Uganda 136.65 33rd

Global warming and plastic pollution entwined in vicious circle, researchers say

Typically viewed as unrelated problems, global warming and plastic pollution are instead inextricably trapped in a "vicious circle" where one feeds the other, researchers  report in Nature Communications. The mutually-reinforcing relationship escalates global warming, the degradation of materials, plastic waste and the leaching of toxic chemicals into the biosphere.

Plastics that we rely on every day will deteriorate more rapidly because of rising global temperatures, and one effect will be a demand for more plastics. Meeting that demand will further compound greenhouse emissions that drive up the global temperature. A self-reinforcing cycle is formed, creating a vicious circle between climate change and plastic pollution.

In 2019, plastics generated 3.4% of global greenhouse gas emissions, or about 1.8 billion tons, mostly on account of their production and conversion from fossil fuels, according to the Organization for Economic Co-operation and Development (OECD). By 2060 that amount is expected to more than double.

The researchers describe a feedback loop linking these emissions with heat, moisture and the weakening structural bonds that lend a wide range of advantageous properties to polymers, the term for materials—like plastic and rubber—that are formed from long chains of large molecules.

The higher the increase in temperature, the more the materials' properties are compromised. The stiffness of commonly used plastics like polyethylene, polypropylene and polyvinyl chloride decreases by more than 20% as temperatures climb between 23°C and 40°C.

This deterioration means more frequent replacement of polymer products—everything from clothing to auto parts and appliances—and consequently greater manufacturing volumes and rates.

Knock-on effects range from rendering food packaging unreliable to the fouling of waterways and fish habitats by an increase in microplastics, he says.

The report also documents the release of volatile organic compounds (VOCs) in a warming climate as well as other hazardous compounds including lubricants, flame retardants, plasticizers, antioxidants, colorants and UV/heat stabilizers. Heat will accelerate diffusion, evaporation and leaching of these substances into the air, soil, and water, the report says.

The researchers draw attention to the combined effects of heat and moisture, which rise together due to global warming. A warmer atmosphere increases the evaporation of moisture and can also hold more water vapour.

Part 1

That's bad news for many materials, but it wreaks particular havoc on plastics when combined with heat. The combined effects of rising temperature and moisture create very challenging conditions for these polymers.

Xin-Feng Wei et al, Plastic pollution amplified by a warming climate, Nature Communications (2024). DOI: 10.1038/s41467-024-46127-9

part 2

Combating counterfeiting: Advanced hologram protection invented

Counterfeiting of various documents, banknotes, or tickets is a common problem that can be encountered in everyday life, even when shopping. Recognizing the scale and seriousness of the problem, researchers decided to look for ways to further reduce the risk of counterfeiting by inventing a new method to produce holographic security labels.

Holograms have been used as an anti-counterfeiting tool for some time. Now, they can be seen on pharmaceutical packaging, brand labels, and even toys. Holograms are much more difficult for forgers to counterfeit than, for example, the watermarks on banknotes, as they require complex micro and nano technologies that traditional printing houses lack.

Combining two technologies has led to international recognition

To enhance the level of holographic protection against forgery and to address this worldwide problem, Lithuanian researchers from KTU Institute of Materials Science came up with the idea of combining two technologically different methods.

One of them is a dot-matrix hologram made of small dots that refract light. "Each dot, which is barely smaller than a human hair, records a periodic structure made up of lines known as a diffraction grating. It causes the light to play in a way that is visible to the observer's eye, similar to a CD or DVD. This dot-matrix hologram, although relatively faster and cheaper and used to expose large areas of the hologram, does not guarantee a very high level of protection.

This is why electron beam lithography is used to expose smaller areas of the hologram. It is a more advanced technology that allows to form high-resolution structures and is practically inaccessible to potential hologram counterfeiters.

Admittedly, holograms were invented for a completely different purpose, to increase the resolution of electronic microscopy.
According to the scientists, the breakthrough of holograms in the fight against counterfeiting came when it was realized that once the original hologram was recorded, it could be copied mechanically by pressing it into another material. This has led to a substantial expansion in the production quantities of holograms.

Fictional films and their holograms of people and even entire cities have led to a rather diverse perception and interpretation of the term itself. The rapid advances in technology have allowed some fictional ideas to become reality, and today, even holograms in full concert arenas can be seen.
When strengthening the protective measures themselves, researchers encourage consumers to keep in mind that holograms can also be counterfeited, so he encourages everyone to inspect the holographic security labels and to remain alert.
Hologram manufacturers usually try to make holograms as bright as possible; the visible features, such as clear objects and different colors, do not glow by chance. Only specific elements of the brand are integrated into the image with different sizes of characters visible. If an observer sees a random glow, it is likely to be either a very unsophisticated hologram or a fake.
The inventors have developed another innovation. It is a digital application for smart devices called "HoloApp", which allows you to see what the hologram looks like on the screen. This enables a better understanding and experience of what a hologram should look like and the ability to identify if it is forged.

Patent filing: worldwide.espacenet.com/patent … 888B2?q=US11846888B2

Science behind once-in-a-lifetime nova outburst that will light up the sky this year

The total solar eclipse isn't the only reason to keep your eyes to the sky this year. For the first time in 80 years, a star system 3,000 light years away will be visible to the naked eye thanks to a once-in-a-lifetime nova outburst.

NASA announced that the nova, which will create a "new" star in the night sky, will light up the night sky some time between now and September and be as bright as the North Star. One of only five recurring novae in our galaxy, it will be visible for a week before it fades back down.

What is nova?

There's a broad class of these sorts of events, and they typically share the trait of having two objects, or sometimes more than two objects, close to each other, and you're transferring mass from one to the other. Eventually, you build up enough mass on usually the hotter object that it ignites, in this case undergoing fusion, and then suddenly you get a very rapid release of energy so it gets much, much brighter.

The star system in question is T Coronae Borealis, or T CrB, and it contains a white dwarf and red giant, two stars that create the perfect conditions for a nova outburst.

A red giant is what happens when a star, like our sun, runs out of fuel and becomes larger and cooler, turning red instead of the white or yellow of a hot star. A white dwarf is what a red giant turns into when it runs out of even more fuel: a very compact star.

What happens when these two stars co-orbit one another is that the white dwarf steadily strips away the atmosphere of the expanding red giant. The white dwarf is much smaller and much more compact, so you build up a little disk of mostly hydrogen and maybe some helium as well sitting on the white dwarf.

Eventually enough of it builds up and basically ignites. It's not literally burning in the sense of fire; it's thermonuclear burn and you have hydrogen undergoing a fusion reaction.

As it undergoes that runaway thermonuclear reaction, the white dwarf gets hotter, bigger and brighter, making it easier for us to see it back on Earth. This entire process is part of the natural lifecycle of these stars and why they happen every 80 years. After a white dwarf like this goes nova, it goes back to stripping gas away from the red giant, building up gas at the same rate before eventually another outburst occurs.

https://news.northeastern.edu/2024/03/18/nova-explosion-new-star/

Scientists Engineer Cow That Makes Human Insulin Proteins in Its Milk

A genetically modified cow has produced proteins needed for human insulin in its milk, and the scientists behind the experiment have high hopes that a herd of these cattle could solve the world's insulin supply problems.

If such a herd were viable – and, based on this first case, that's still a long way off – the researchers think it could out-compete current insulin production methods, which rely on genetically modified yeast and bacteria.

While turning to cows for human insulin supply isn't new, the new study is the first time 'human' insulin production has been achieved in a genetically modified bovine.

Researchers inserted a particular segment of human DNA that codes for proinsulin (a protein that's converted to insulin) into the cell nuclei of 10 cow embryos, which were then inserted into the wombs of normal cows. Only one of these genetically modified embryos developed into a pregnancy, leading to the natural birth of a living, transgenic calf. When it reached maturity, the team made a variety of attempts to get the genetically modified cow pregnant, by artificial insemination, in vitro fertilization, and even the old-fashioned way. None were successful, but the team notes this may be more to do with how the embryo was created than the fact it was genetically modified. 

Eventually they were able to get the cow to lactate via hormonal induction, using an undisclosed method .

The cow didn't lactate as much as it would during a pregnancy, but what little milk it did produce over a month was examined to look for specific proteins, using western blotting and mass spectrometry.

The blotting revealed two bands with similar molecular masses to human proinsulin and insulin, which were not present in the milk of non-transgenic cows. Mass spectrometry indicated the presence of the C-peptide that's removed from human proinsulin in the process of creating insulin, which suggests that enzymes in the cow's milk may have converted the 'human' proinsulin into insulin.

Part 1

In 2014, a similar kind of genetic modification was achieved in mice, whose milk contained up to 8.1 grams per liter of human proinsulin. Comparable concentrations were not reported in this new study, but that hasn't stopped Wheeler from thinking about scaling up.

A typical unit of insulin is 0.0347 milligrams, so if, as Wheeler proposes, each cow could make one gram of insulin per liter of milk, that's 28,818 units of insulin.

https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/10.10...

Part 2

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Virus helped brain evolution
Remnants of an ancient viral infection are essential for producing myelin, a protein that insulates nerve fibres, in most vertebrates. Certain viruses insert DNA into the genetic material of the cells they invade. Sometimes, these insertions become permanent and even aid evolutionary processes. Myelin helps nerves to send electrical signals faster, grow longer and thinner so they can be packed in more efficiently. “As a result of myelin, brains became more complex and vertebrates became more diverse,” says stem-cell biologist and study co-author Robin Franklin.

Part 1

Ancient viruses helped speedy nerves evolve

The trick happened multiple independent times in jawed animals

One particular retrovirus — embedded in the DNA of jawed vertebrates — helps turn on production of a protein needed to insulate nerve fibers, researchers report February 15 in Cell. Such insulation, called myelin, may have helped make speedy thoughts and complex brains possible.

The retrovirus trick was so handy, in fact, that it showed up many times in the evolution of vertebrates with jaws, the team found.

Retroviruses are RNA viruses that make DNA copies of themselves to embed in a host’s DNA. Rarely, these insertions can become a permanent part of who we are, being passed down from parent to offspring. Scientists once thought remnants of of these ancient viruses — known as jumping genes or retrotransposons — as genetic garbage, but that impression is changing.

 Scientists are finding more and more evidence that these retrotransposons and retroviruses have influenced the evolution of life on the planet.

Remains of retroviruses were already known to have aided the evolution of the placenta, the immune system and other important milestones in human evolution . Now, they’re implicated in helping to produce myelin.

Part 2

Myelin is a coating of fat and protein that encases long nerve fibers known as axons. The coating works a bit like the insulation around an electrical wire: Nerves sheathed in myelin can send electrical signals faster than uninsulated nerves can.

Coated nerve fibers can also be thinner and grow longer than they would without insulation, enabling animals to grow bigger. And thinner fibers can be packed into the nervous system more efficiently.

As a result of myelin, brains became more complex and vertebrates became more diverse. If myelination hadn’t happened in early vertebrate evolution, we wouldn’t have the whole galaxy of vertebrate diversity that we see now.

T. Ghosh et al. A retroviral link to vertebrate myelination through retrotransposon.... Cell. Published online February 15, 2024. doi: 10.1016/j.cell.2024.01.011.

Part 3

What are retroviruses?

A retrovirus is a type of RNA virus. RNA viruses have genes encoded in RNA instead of DNA. Like other viruses, retroviruses need to use the cellular machinery of the organisms they infect to make copies of themselves. Infection by a retrovirus, however, requires an additional step.

Retroviruses are "retro" because they reverse the direction of the normal gene-copying process. Usually, cells convert DNA into RNA so that it can be made into proteins. But with retroviruses, the process has to start by going backward.

A retrovirus replicates itself by first reverse-coding its genes into the DNA of the cells it infects. It does this with an enzyme called reverse transcriptase.

Retroviruses use reverse transcriptase to transform their single-stranded RNA into double-stranded DNA. DNA molecules store the genetic information of human cells and cells from other life forms.

Once transformed from RNA to DNA, the viral DNA is integrated into the genome of the infected cells. When this happens, the cells are tricked into copying these genes as part of the normal replication process.

The cell can also transcribe the DNA back into RNA as the first step in making viral proteins.

Retroviruses are sometimes used as gene delivery methods in gene therapy. This is because these viruses are both easy to modify and easily integrated into the host genome.

This means that, in theory, retroviruses can be used to make cellular machinery to produce proteins in an ongoing way. For example, scientists have used retroviruses to help diabetic rats make their own insulin.

Many retroviruses have been identified that infect non-human animals. Only a few retroviruses are known to cause illness in human beings, however. The most well-known of these are HIV and human T-cell lymphotropic virus.

Part 4

Life's building blocks are surprisingly stable in Venus-like conditions: Study

If there is life in the solar system beyond Earth, it might be found in the clouds of Venus. In contrast to the planet's blisteringly inhospitable surface, Venus' cloud layer, which extends from 30 to 40 miles above the surface, hosts milder temperatures that could support some extreme forms of life.

If it's out there, scientists have assumed that any Venusian cloud inhabitant would look very different from life forms on Earth. That's because the clouds themselves are made from highly toxic droplets of sulfuric acid—an intensely corrosive chemical that is known to dissolve metals and destroy most biological molecules on Earth.

But a new study by  researchers may challenge that assumption. Published today in the journal Astrobiology, the study reports that, in fact, some key building blocks of life can persist in solutions of concentrated sulfuric acid.

The study's authors have found that 19 amino acids that are essential to life on Earth are stable for up to four weeks when placed in vials of sulfuric acid at concentrations similar to those in Venus' clouds. In particular, they found that the molecular "backbone" of all 19 amino acids remained intact in sulfuric acid solutions ranging in concentration from 81% to 98%.

What is  surprising is that concentrated sulfuric acid is not a solvent that is universally hostile to organic chemistry.

We are finding that building blocks of life on Earth are stable in sulfuric acid, and this is very intriguing for the idea of the possibility of life on Venus.

It doesn't mean that life there will be the same as here. In fact, we know it can't be. But this work advances the notion that Venus' clouds could support complex chemicals needed for life.

The search for life in Venus' clouds has gained momentum in recent years, spurred in part by a controversial detection of phosphine—a molecule that is considered to be one signature of life—in the planet's atmosphere. While that detection remains under debate, the news has reinvigorated an old question: Could Earth's sister planet actually host life?

In search of an answer, scientists are planning several missions to Venus, including the first largely privately funded mission to the planet, backed by California-based launch company Rocket Lab. That mission aims to send a spacecraft through the planet's clouds to analyze their chemistry for signs of organic molecules.

Maxwell D. Seager et al, Stability of 20 Biogenic Amino Acids in Concentrated Sulfuric Acid: Implications for the Habitability of Venus' Clouds, Astrobiology (2024). DOI: 10.1089/ast.2023.0082

Why water freezes at a range of temperatures

 Water's freezing point is generally accepted to be 32 degrees Fahrenheit. But that is due to ice nucleation—impurities in everyday water raise its freezing point to this temperature. Now, researchers unveil a theoretical model that shows how specific structural details on surfaces can influence water's freezing point.

Ice nucleation is one of the most common phenomena in the atmosphere. "In the 1950s and 1960s, there was a surge of interest in ice nucleation to control weather through cloud seeding and for other military goals. Some studies addressed how small shapes promote ice nucleation, but the theory was undeveloped, and no one has done anything quantitative.

When temperatures drop, the molecules in liquid water, which normally speed around and zip past one another, lose energy and slow down. Once they lose enough energy, they grind to a halt, orient themselves to avoid repulsions and maximize attractions, and vibrate in place, forming the crystalline network of water molecules we call ice.

When liquid water is completely pure, ice may not form until the temperature gets down to a frigid –51 degrees Fahrenheit; this is called supercooling. But when even the tiniest impurities—soot, bacteria or even particular proteins—are present in water, ice crystals can form more easily on the surfaces, resulting in ice formation at temperatures warmer than –51 degrees Fahrenheit.

Part 1