Researchers at the Ancient Genomics Laboratory at the Crick studied available genome-wide DNA from 677 individuals dating to Stone Age Europe, spanning the movement of Neolithic farmers from the Near East into Europe about 8000 years ago, where they mixed with Mesolithic hunter-gatherers already in Europe.

They were interested in whether any particular genes might have coded for adaptations important to early farming groups, and looked for evidence of rapid evolution in these populations.

Since about 20% of the ancestry of descendant late Stone Age people could be traced to the local European hunter-gatherers, the researchers also asked whether any particular genes showed evidence of more hunter-gatherer ancestry.

They found that a large genetic region responsible for immune responses to diseases — the major histocompatibility complex (MHC) — showed both the strongest evidence of rapid evolution, and more Mesolithic hunter-gatherer ancestry than expected, suggesting that genetic variants in the MHC region already present in Europe were passed down preferentially.

It has previously been thought that the transition to farming was associated with increased natural selection on immunity variants, as people started living closer to animals and eating more animal products. This research supports this view, but also shows that diversity in immune genes may be just as important as adaptation to lifestyle.

The research team speculates that either the hunter-gatherers already had genetic adaptations against bacteria, viruses or other microorganisms in Europe, or that having many different forms of the genes was advantageous.

Tom Davy, PhD student at the Francis Crick Institute and lead author, said: “It was really exciting to see for the first time that immunity is important for the transition to farming in a prehistoric population. The later Neolithic people had far more farmer ancestry in general, so we expected to see the same at the MHC region, especially as many diseases have been linked to Neolithic periods. But we saw about 50:50 ancestry from Neolithic farmers and Mesolithic hunter-gatherers here, showing that natural selection favoured genes from the hunter-gatherers already in Europe.

“At the moment we’re not quite sure whythis happened, but a proposal is that the European hunter-gatherers had genetic variations which allowed them to fight Europe-specific diseases. Or picking up a variety of genes from both hunter-gatherers and farmers was beneficial because it resulted in lots of diversity at this major group of genes, allowing people to better fight off disease.”

The team also confirmed results from previous studies, showing that genes coding for skin pigmentation showed the greatest representation for Neolithic farmer ancestry, with these variations coming into Europe from the Near East. This may be to maintain vitamin D levels when sources, such as diet and exposure to sunlight, change.

Pontus Skoglund, Group Leader of the Ancient Genomics Laboratory at the Crick, said: “The shift to farming was an important transition all over the world, resulting in changing diets and exposure to infectious disease.

“Previous research has suggested that adaptation in genetic regions relating to immunity, such as the MHC, has been important in recent time periods, and this research now provides similar evidence for adaptation in prehistory. By growing the ancient genomic record, we will be able to better understand the role of immunity in other periods of the human past.”

“Six different models have been published in an attempt to explain the radar signatures of the icy moons that orbit Jupiter and Saturn,” said Hofgartner, first author of the study, which was published this month in Nature Astronomy. “The way these objects scatter radar is drastically different than that of the rocky worlds, such as Mars and Earth, as well as smaller bodies such as asteroids and comets.”

The objects are also extremely bright, even in areas where they should be darker.

“When we look up at Earth’s moon it looks like a circular disk, even though we know it’s a sphere. Planets and other moons similarly look like disks through telescopes,” Hofgartner said. “While making radar observations, the center of the disk is very bright and the edges much darker. The change from center to edge is very different for these icy satellites than for rocky worlds.”

In collaboration with Dr. Kevin Hand of NASA’s Jet Propulsion Laboratory, Hofgartner argues that the extraordinary radar properties of these satellites, such as their reflectiveness and polarization (the orientation of light waves as they propagate through space) is very likely to be explained by the coherent backscatter opposition effect (CBOE).

“When you’re at opposition, the Sun is positioned directly behind you on the line between you and an object, the surface appears much brighter than it would otherwise,” Hofgartner said. “This is known as the opposition effect. In the case of radar, a transmitter stands in for the Sun and a receiver for your eyes.”

An icy surface, Hofgartner explained, has an even stronger opposition effect than normal. For every scattering path of light bouncing through the ice, at opposition there is a path in the exact opposite direction. Because the two paths have precisely the same length, they combine coherently, resulting in further brightening.

In the 1990s, studies were published stating that the CBOE was one explanation for the anomalous radar signatures of icy satellites, but other explanations could explain the data equally well. Hofgartner and Hand improved the polarization description of the CBOE model and also showed that their modified CBOE model is the only published model that can explain all of the icy satellite radar properties.

“I think that tells us that the surfaces of these objects and their subsurfaces down to many meters are very tortured,” Hofgartner said. “They’re not very uniform. Icy rocks dominate the landscape, perhaps looking somewhat like the chaotic mess after a landslide. That would explain why the light is bouncing in so many different directions, giving us these unusual polarization signatures.”

The radar observations Hofgartner and Hand used were from the Arecibo Observatory, which was one of only two telescopes making radar observations of icy satellites until it was severely damaged by the collapse of its support structure, antenna and dome assembly and subsequently decommissioned. The researchers hope to make follow-up observations when possible and plan to study additional archival data that may shed even more light on icy satellites and the CBOE, as well as radar studies of ice at the poles of Mercury, the Moon, and Mars.

Singlet fission (SF) is a process in which an organic chromophore (a molecule that absorbs light) in an excited singlet state transfers energy to a neighboring chromophore, resulting in two correlated triplet exciton pairs (pairs of bound electron-hole states, a “hole” signifying the absence of an electron) that decay to low energy triplet excitons. These excitons have long lifetimes and show efficient light emission, making SF promising for efficient light energy conversion.

However, the molecular design of SF-based materials is limited by the requirement that the energy of the excited singlet state must be at least equal to the energy of the two triplet states. One way to overcome this limit is by applying external stimuli, such as temperature or pressure, to manipulate the SF process.

Now, in a collaborative study published in the journal Chemical Science, Prof. Gaku Fukuhara of Tokyo Institute of Technology (Tokyo Tech) and Prof. Taku Hasobe of Keio University in Japan demonstrate, for the first time, a hydrostatic pressure-based strategy for controlling the dynamics of the SF process, opening doors to the design and fabrication of novel, tunable SF-based materials.

“We demonstrated hydrostatic pressure-controlled formation and dissociation of correlated triplet pairs in SF by means of pressure-dependent UV/vis and fluorescence spectrometry along with fluorescence lifetime and nanosecond transient absorption measurements,” explain Prof. Fukuhara and Prof. Hasobe.

In their study, the researchers used a biphenyl-bridged pentacene dimer as the model chromophore and tested its response for a range of hydrostatic pressures, from 0.1 MPa (atmospheric pressure) to 180 MPa, in three different solvents: toluene, methylcyclohexane and tetrahydrofuran.

Using a custom-built high pressure apparatus, the researchers measured the rate of exciton generation at different pressures by monitoring the fluorescence lifetime decay of the chromophore, which indicates how long the chromophore takes to emit a photon after the initial excitation. They found that the rate constant for the generation of correlated triplet exciton pairs increased with pressure, indicating that higher pressure leads to a faster SF process.

Using the technique of nanosecond transient absorption, the researchers then tracked the decay of the triplet excitons and found them to have shortened lifetimes under high pressure.

Based on quantum yield calculation and thermodynamic estimations, the researchers uncovered two mechanisms underlying the generating correlated pairs and individual excitons. In the case of the correlated exciton pairs, the SF process was driven by the solvation and desolvation of the molecule, leading to a more compact and thermodynamically stable exciton structure than the excited chromophore. In contrast, the individual excitons produced by the dissociation process were found to be thermodynamically bulkier, causing the solvent molecules to cluster around and deactivate them at high pressures.

With these findings, the researchers have shed light on the interactions between the different systems (pressure, solvent, chromophore, excitons) involved in the SF process, suggesting a suitable alternative to the conventional control strategy for SF.

“Our study provides a new perspective on the control of intramolecular SF using hydrostatic pressure as an external stimulus. This dynamic control concept could be extended to other SF scaffolds and relevant systems that are difficult to control in both ground and excited states,” speculate Prof. Fukuhara and Prof. Hasobe.

We can certainly hope to see the application of SF-based materials in the design of efficient organic solar cells and photoconversion devices.

With moderate increases in temperature, plants grow taller to avoid hotter ground and get fresher air. A landmark study published in the journal Nature Communications demonstrates that microRNA or miRNA is required for this growth. The study also identifies which miRNA molecules — out of more than 100 possibilities — are the essential ones.

“We found that without miRNA plants will not grow, even if we raise temperatures, even in the presence of added growth hormones,” said UCR botany professor and study co-author Meng Chen.

RNA is a nucleic acid present in all living cells, and its role is to act as a messenger carrying instructions from a cell’s DNA for creating a variety of proteins. MicroRNA is also necessary for healthy development in biological cells. It is created to bind to a specific RNA target and prevent that target from creating what it was designed to manufacture.

“MiRNA inhibits the production of its target RNA by inducing a cleavage in its target, or by inhibiting its target RNA from translating into another protein,” said UCR botany professor and study co-author Xuemei Chen.

Xuemei Chen’s lab at UCR helped discover miRNA in plants. Meng Chen’s laboratory previously identified components involved in the early stages of plants’ temperature sensitivity. The two groups of scientists joined forces to learn whether miRNA, which is so significant in other life forms, also plays a role in plants’ temperature responses.

For this test, the scientists only looked at mild increases in temperature, from 21 to 27 degrees Celsius. For reference, room temperature averages about 20 C. “We didn’t look at stress responses. We wanted to study temperature sensing without raising it to a level that would kill the plants,” Meng Chen said.

The researchers took Arabidopsis, a small flowering plant related to mustard and cabbage, and studied mutant forms with very low levels of miRNA. Without the miRNA, the mutant Arabidopsis could not respond to the change in temperature by growing as it should have.

Then they did a genetics experiment. “We asked whether we could make additional mutations on the mutant Arabidopsis deficient in making miRNAs and restore their ability to sense temperature,” Xuemei Chen said. The second experiment worked, “perfectly,” she said, and it revealed a gene responsible for restoring miRNA levels as well as the plant’s heat sensing abilities.

Next, the team faced a challenge in searching for the precise miRNA involved in temperature response. Arabidopsis manufactures 140 miRNA molecules. The scientists assumed levels of the responsible molecules would increase as temperatures did, but it didn’t happen that way.

Recalling that miRNA binds to and shuts down target RNA molecules, the team instead looked at target RNA molecule levels that were different in the original mutant Arabidopsis plant and in the second mutant plant they created.

“Looking at this we found the targets of 14 miRNA changed, and alongside the targets, we also found the miRNA,” Xuemei Chen said.

Having identified the right miRNA molecules, the team finally put together a comprehensive picture of temperature response. It involves two essential parts: molecules that sense temperature, and auxin, a hormone that allows a response to what’s been sensed by promoting plant growth.

“In between the sensor and the responder is miRNA. Without it, plants can sense heat but cannot respond to it by growing. It is a gatekeeper that can shut down — or allow — plants to deal with environmental temperature changes,” Meng Chen said.

During their experiments, the team found the miRNA is also required for plants’ response to reflected shade from neighboring plants.

“Our discovery connected the dots between three elements found in all plants that are key for plant responses to their environments,” Meng Chen said. “This includes sensors that monitor temperature and light changes, hormones that drive plant growth, and miRNA that controls plant development.”

The researchers hope their findings can be used to increase crop yields as the climate changes.

“The potential is that we use this to manipulate plant responses to local temperature and light conditions and control their growth in diverse environments,” Meng Chen said.

Vibrio vulnificus bacteria grow in warm shallow coastal waters and can infect a cut or insect bite during contact with seawater. A new study led by the UK’s University of East Anglia (UEA) shows that the number of V. vulnificus infections along the East Coast of the US, a global hotspot for such infections, has gone up from 10 to 80 per year over a 30-year period.

In addition, every year cases occur further north. In the late 1980s, cases were found in the Gulf of Mexico and along the southern Atlantic coast but were rare north of Georgia. Today they can be found as far north as Philadelphia.

The researchers predict that by 2041-2060 infections may spread to encompass major population centres around New York. Combined with a growing and increasingly elderly population, who are more susceptible to infection, annual case numbers could double.

By 2081-2100, infections may be present in every Eastern US state under medium-to-high future emissions and warming scenarios.

The findings, published today in the journal Scientific Reports, are important because although the number of cases in the US is not large, someone infected with V. vulnificus has a one-in-five chance of dying. It is also the most expensive marine pathogen in the US to treat.

The illness peaks in the summer and sees the bacteria spread rapidly and severely damage the person’s flesh. As a result, it is commonly called a ‘flesh eating’ illness and many people who survive have had limbs amputated.

Lead author of the study Elizabeth Archer, a postgraduate researcher in UEA’s School of Environmental Sciences, said: “The projected expansion of infections highlights the need for increased individual and public health awareness in the areas affected. This is crucial as prompt action when symptoms occur is necessary to prevent major health consequences.

“Greenhouse gas emissions from human activity are changing our climate and the impacts may be especially acute on the world’s coastlines, which provide a major boundary between natural ecosystems and human populations and are an important source of human disease.

“We show that by the end of the 21^st Century, V. vulnificus infections will extend further northwards but how far North will depend upon the degree of further warming and therefore on our future greenhouse gas emissions.

“If emissions are kept low, then cases may extend northwards only as far as Connecticut. If emissions are high, infections are predicted to occur in every US state on the East Coast. By the end of the 21^st Century we predict that around 140-200 V. vulnificus infections may be reported each year.”

The research team suggests that individuals and health authorities could be warned in real time about particularly risky environmental conditions through marine or Vibrio specific early warning systems.

Active control measures could include greater awareness programmes for at risk groups, for example the elderly and individuals with underlying health conditions, and coastal signage during high-risk periods.

Co-author Prof Iain Lake from UEA said: “The observation that cases of V. vulnificus have expanded northwards along the East Coast of the US is an indication of the effect that climate change is already having on human health and the coastline. Knowing where cases are likely to occur in future should help health services plan for the future.”

The study is the first to map how the locations of V. vulnificus cases have changed along the eastern coastline of the US. It also the first to explore how climate change may influence the spread of cases in the future.

Information on where people caught V. vulnificus infection was obtained from the US Centers for Disease Control and Prevention. This allowed the team to map how cases of Vibrio vulnificus have extended northwards over 30 years from 1988-2018.

Temperature information based on observations and computer-based climate models were then used to predict where in the US cases might occur by the end of the 21^st Century.

Co-author Prof James Oliver from the University of North Carolina Charlotte, in the US, said: “This is a landmark paper which not only ties global climate change to disease but provides strong evidence for the environmental spread of this extremely deadly bacterial pathogen.”

One way to identify and rectify these defects is by measuring the spatial distribution of electric properties of these devices. However, standard sensor probes do not offer the required spatial resolution, and can only determine the spatially averaged-out electric properties. Due to this, it is possible to detect only the presence of defects, not their location.

Fortunately, liquid crystal droplets (LCDs)-micron-sized droplets of soft matter with molecular orientational order-offer hope on this front. LCDs respond strongly to external stimuli such as an electric field, and can thus act as a high-resolution probe.

Capitalizing on this promise, Dr. Shinji Bono and Prof. Satoshi Konishi from Ritsumeikan University, Japan, have now utilized LCDs for visualizing the electric properties of microstructured electrodes via a technique called particle imaging electrometry. Their findings were published in Volume 13 of the journal Scientific Reports on 16 March 2023.

Dr. Bono explains the research methodology. “The LCDs were dispersed on microelectrodes arranged in a comb-like structure atop a glass slab. Their molecular orientations, determined using polarized optical microscopy, were randomly distributed when the electric field was absent. Then, a voltage was applied across the electrodes.” Because of this, the LCDs between the electrodes and in front of the electrode ends underwent rotation, their molecular orientations lining up perpendicular and parallel to the electrodes, respectively. This alignment, revealed by COMSOL simulations performed by the researchers, corresponded to the direction of the electric field, and occurred faster with increasing voltage. The relaxation frequency of rotation was found to vary as the square of the applied voltage.

Further, at high voltages, the LCDs showed translation (linear motion) towards the electrodes, especially their endpoints, the regions with maximum electrostatic energy density. Based on this behavior, the researchers could produce an array of LCDs via periodic modulation of the energy density in a micro-capacitive MEMS device. The LCD array, in turn, served as a periodic modulator of the refractive index, a number characterizing the light bending ability of a material.

These results thus demonstrate that the electric properties of microelectrodes and microelectric devices can be visualized simply by observing the rotational and translational behavior of LCDs under an electric field. Moreover, the technique provides a high spatial resolution (10 μm) as well as high detection accuracy (5 μV/μm). In light of these features, Prof. Konishi has high hopes for its applications. “It will help improve the design and fabrication of integrated microelectrical devices by providing information on the defect location, which so far has remained unavailable. In turn, more sophisticated MEMS technology may become available soon,” he concludes.

“This was the first study to evaluate the joint effects of fitness and blood pressure on the risk of dying from cardiovascular disease,” said study author Professor Jari Laukkanen of the University of Eastern Finland, Kuopio, Finland. “The results suggest that being fit helps protect against some of the negative effects of high blood pressure.”

Nearly 1.3 billion adults aged 30 to 79 years worldwide have high blood pressure (hypertension). Hypertension is a major risk factor for heart attack and stroke and a leading cause of premature death globally. Previous studies have shown that high cardiorespiratory fitness is linked with greater longevity. This study examined the interplay between blood pressure, fitness and risk of death from cardiovascular disease.

The study included 2,280 men aged 42 to 61 years living in eastern Finland and enrolled in the Kuopio Ischaemic Heart Disease Risk Factor Study. Baseline measurements were conducted between 1984 and 1989. These included blood pressure and cardiorespiratory fitness, which was assessed as maximal oxygen uptake while riding a stationary bicycle. Blood pressure was classified as normal or high, and fitness was classified as low, medium or high.

The average age at baseline was 53 years. Participants were followed up until 2018. During a median follow up of 29 years, there were 644 deaths due to cardiovascular disease. The risk of death from cardiovascular disease was analysed after adjusting for age, body mass index, cholesterol levels, smoking status, type 2 diabetes, coronary heart disease, use of antihypertensive medication, alcohol consumption, physical activity, socioeconomic status, and high sensitivity C-reactive protein (a marker of inflammation).

Considering blood pressure alone, compared to normal values, high blood pressure was associated with a 39% increased risk of cardiovascular mortality (hazard ratio [HR] 1.39; 95% confidence interval [CI] 1.17-1.63). Considering fitness alone, compared with high levels, low fitness was associated with a 74% elevated likelihood of cardiovascular death (HR 1.74; 95% CI 1.35-2.23).

To evaluate the joint associations of blood pressure and fitness with risk of cardiovascular death, participants were categorised into four groups: 1) normal blood pressure and high fitness (this was the reference group for comparison); 2) normal blood pressure and low fitness; 3) high blood pressure and high fitness; 4) high blood pressure and low fitness.

Men with high blood pressure and low fitness had a more than doubled risk of cardiovascular death compared to those with normal blood pressure and high fitness (HR 2.35; 95% CI 1.81-3.04). When men with high blood pressure had high fitness levels, their elevated risk of cardiovascular risk persisted but was weaker: it was 55% higher than those with normal blood pressure and high fitness (HR 1.55; 95% CI 1.16-2.07).

Professor Laukkanen said: “Both high blood pressure and low fitness levels were each associated with an increased risk of cardiovascular death. High fitness levels attenuated, but did not eliminate, the increased risk of cardiovascular mortality in men with elevated blood pressure.”

The paper states: The inability of cardiorespiratory fitness to completely eliminate the risk of cardiovascular mortality in those with high blood pressure could partly be due to the strong, independent and causal relationship between blood pressure and cardiovascular disease.

Professor Laukkanen concluded: “Getting blood pressure under control should remain a goal in those with elevated levels. Our study indicates that men with high blood pressure should also aim to improve their fitness levels with regular physical activity. In addition to habitual exercise, avoiding excess body weight may enhance fitness.”

ESC guidelines recommend that adults of all ages to strive for at least 150 to 300 minutes a week of moderate-intensity or 75 to 150 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination, to reduce all-cause death, cardiovascular death, and illness.

Launched in November 2022, ChatGPT is the latest chatbot and artificial intelligence (AI) platform touted as having the potential to revolutionise research and education.

However, as it becomes ever more advanced, the technology has also prompted concerns across the education sector about academic honesty and plagiarism.

To address some of these, the new study directly uses ChatGPT to demonstrate how sophisticated Large Language Machines (LLMs) have become but also the steps that can be taken to ensure its influence remains a positive one.

Published in the peer-reviewed journal Innovations in Education and Teaching International, the research was conceived by academics from Plymouth Marjon University and the University of Plymouth.

For the majority of the paper, they used a series of prompts and questions to encourage ChatGPT to produce content in an academic style. These included:

• Write an original academic paper, with references, describing the implications of GPT-3 for assessment in higher education;
• How can academics prevent students plagiarising using GPT-3?
• Are there any technologies which will check if work has been written by a chatbot?
• Produce several witty and intelligent titles for an academic research paper on the challenges universities face in ChatGPT and plagiarism.

Once the text was generated, they copied and pasted the output into the manuscript, ordered it broadly following the structure suggested by ChatGPT, and then inserted genuine references throughout.

This process was only revealed to readers in the paper’s Discussion section, which was written directly by the researchers without the software’s input.

In that section, the study’s authors highlight that the text produced by ChatGPT — while much more sophisticated than previous innovations in this area — can be relatively formulaic, and that a number of existing AI-detection tools would pick up on that.

However, they say their findings should serve as a wake-up call to university staff to think very carefully about the design of their assessments and ways to ensure that academic dishonesty is clearly explained to students and minimised.

Professor Debby Cotton, Director of Academic Practice and Professor of Higher Education at Plymouth Marjon University, is the study’s lead author. She said: “This latest AI development obviously brings huge challenges for universities, not least in testing student knowledge and teaching writing skills — but looking positively it is an opportunity for us to rethink what we want students to learn and why. I’d like to think that AI would enable us to automate some of the more administrative tasks academics do, allowing more time to be spent working with students”

Corresponding author Dr Peter Cotton, Associate Professor in Ecology at the University of Plymouth, added: “Banning ChatGPT, as was done within New York schools, can only be a short-term solution while we think how to address the issues. AI is already widely accessible to students outside their institutions, and companies like Microsoft and Google are rapidly incorporating it into search engines and Office suites. The chat (sic) is already out of the bag, and the challenge for universities will be to adapt to a paradigm where the use of AI is the expected norm.”

Dr Reuben Shipway, Lecturer in Marine Biology at the University of Plymouth, said: “With any new revolutionary technology — and this is a revolutionary technology — there will be winners and losers. The losers will be those that fail to adapt to a rapidly changing landscape. The winners will take a pragmatic approach and leverage this technology to their advantage.”