Tech

Natural Killer (NK) cells have long been the soldiers of the immune system that prevents the growth and spread of cancers, and subduing this army of cells is one of the key ways that tumours take hold.

Australian researchers have discovered a protein found in humans that prevents NK cells from doing their job fighting cancer. Importantly the study, published today in the prestigious journal Science Signaling, reveals that blocking this protein - with a naturally occurring hormone currently commercially available - turbocharges the immune system to fight off the cancer cells.

The discovery, in preclinical models, means this hormone, called Follistatin, may be a new and highly potent immune-therapeutic drug for the eradication of cancers such as melanoma.

In the paper, the research team led by Dr Fernando Guimaraes, from the University of Queensland's Diamantina Institute and Professor Nicholas Huntington, from the Monash Biomedicine Discovery Institute, together with researchers from the Walter and Eliza Hall Medical Research Institute, studied what are known as 'Natural Killer' cells in the immune system. These NK cells are crucial in protecting against the triggering of cancer and the spread or metastasizing of cancer cells.

One of the key reasons why cancer cells take hold and grow occurs when these NK cells are in some way suppressed. To date the signals that inhibit NK cells have remained largely a mystery.

The scientists found that a protein - called Activin-A - which is found naturally in both healthy human cells and cancer cells, directly disables the NK cell's capacity to halt cancer growth.

Importantly, they were able to block Activin-A in preclinical models, using human and mouse NK cell models, with the hormone Follistatin.

According to Professor Huntington, "these findings may open the door to novel immune-therapy drugs which provide a deeper and more durable way to overcome the immune suppression seen in cancer, improving patient outcomes."

The series of 34 small earthquakes between April 2018 and May 2019 occurred within 10 km of two active oil extraction sites at Brockham and Horse Hill in Surrey.

Many residents of Newdigate, Dorking, Horley and Charlwood in Surrey, and Crawley and Horsham in West Sussex, felt the largest quake, which reached a magnitude of 3.2.[4]

As the British Isles don't lie along boundaries separating two tectonic plates, earthquakes that are felt by people are relatively rare - so there was concern that the swarm was triggered by nearby drilling and extraction.

Now, the first in-depth study of the quakes by Imperial, the University of Bristol, and the British Geological Survey (BGS), has shown no direct link between oil extraction and earthquakes in the region.

The authors therefore believe natural causes were behind the earthquakes, which occurred close to Gatwick Airport in West Sussex.

Lead author Dr Stephen Hicks, of Imperial's Department of Earth Science and Engineering, said: "The quakes seem to have occurred naturally, and our findings suggest their closeness to oil extraction sites is probably a coincidence."

The paper is published today in Seismological Research Letters.

Clues in the ground

During the early stages of the swarm, the researchers installed seismometers - instruments that measure ground vibrations - around the affected areas[1]. The highly sensitive devices tracked the timings, strengths, and distribution of earthquakes.

The researchers also used earthquake data from existing sensors in citizens' homes, known as 'RaspberryShakes', that had been 'listening' since late 2017 for seismic activity in the area.

Based on data from the seismometers, the study team examined a variety of properties of the Surrey quakes and compared them to previous ones that were caused by both human activities and by natural causes in the UK and elsewhere.

Most natural earthquakes in the UK cause rocks on either side of weaknesses in the ground, known as faults, to move horizontally. In contrast, earthquakes caused by oil extraction cause rocks either side of faults to move vertically.

The researchers found that the Surrey swarm quakes moved ancient faults horizontally, indicating that the quakes would probably have happened regardless of nearby oil extraction.

From the BGS seismometers, the researchers detected 168 small magnitude earthquakes between 2018 and 2019. The first cluster of earthquakes happened in April 2018, long after oil extraction tests in 2016, but well before further extended tests starting in July 2018, adding to the evidence that they were naturally caused.

Dr Hicks said: "The ground vibrations recorded from earthquakes provide clues that hint at their cause. There are increasing examples worldwide of human activity causing earthquakes, but it can be difficult to work out which newer cases are natural, and which are human-caused."

Correlations

The researchers also looked at the distance between the earthquakes and extraction sites. Rather than cluster round the extraction sites, the quakes were distributed in a tight cluster more than 3 km away from the extraction sites.

This area, said Dr Hicks, is too far away to link the quakes to oil extraction. He said: "It would be unprecedented for this type and scale of oil extraction to affect sites more than a kilometre away."

The team also examined the depth at which the quakes occurred. To do this, they compared the locations of the earthquakes with images of rock layers beneath the area. The images were created by measuring the reflection of sound waves off each layer (see Fig 3).

They found that although the Surrey earthquakes were shallow (around 2.5 km deep), they occurred deeper than rock formations from which oil is extracted (less than 1 km deep).

The paper is the first piece of research that uses high-precision data and modelling to look at the cause of the Surrey swarm. The researchers are unsure why the swarm came about suddenly in one of the UK's least seismically active areas - and it's not currently possible to predict natural earthquakes.

The authors say the swarm, like most natural earthquakes in the UK, could have been caused by ongoing collision of the African and Eurasian tectonic plates in the Mediterranean Sea - the UK's nearest plate boundary - which stresses the crust and causes earthquakes across Europe.

Dr Hicks said: "This is not the first time earthquakes have come seemingly from nowhere and without human input. Decades of instrumental recordings and hundreds years of historical accounts of earthquakes show that similar seismic swarms have happened in the UK before due to long-term tectonic stresses and without any clear link to human activities."

Industrial activities have been known to cause earthquakes in the past, known as 'induced seismicity'. In most of these cases, quakes are caused by injecting fluids for hydraulic fracturing (fracking) or disposal of waste fluids. Since fracking does not currently take place in the Surrey or Sussex area, this study focused on conventional oil extraction, in which there is no such large-scale injection of fluid.

Dr Hicks added: "If oil extraction caused the earthquakes, then it did so by a mechanism that hasn't yet been reported anywhere else in the world."

The researchers are continuing to monitor quakes in the area for the foreseeable future. Dr Hicks said: "The more data we have, the more we'll know about the causes and effects of these earthquakes. Who knows which clues from the ground we'll pick up in the future."

WASHINGTON, D.C., August 27, 2019 -- Scientists are using nanoparticle screening on personal care products and finding previously thought toxic chemicals may not be harmful.

In a paper published in Biomicrofluidics, from AIP Publishing, researchers successfully used microchips to demonstrate titanium dioxide, a chemical found in most sunscreens, not only is nontoxic but also offers protection against ultraviolet damage to skin cells.

Because of their miniscule size, nanoparticles of a material don't have the same physical, chemical, mechanical or optical properties as the same material would on a bigger scale. This means that something that might not be toxic on a bigger scale could be toxic on a smaller scale and vice versa.

Author Craig Priest said a nanomaterial included in a personal care product may remain on the body for many hours and be exposed to air, moisture, light and heat along with sweat, oils and wax from the skin. This could either enhance or diminish toxicity.

The authors chose to investigate UV radiation for its simplicity and for its potential for inclusion in a multiparameter study between nanoparticles and external stressors, such as sunlight.

Previous nanotoxicity screening methods were laborious and time-consuming. Microfluidic devices present an optimistic future for nanoparticle analysis, offering reduced cost, small sample volumes, controllability and reproducibility.

"Nanoparticles are found in many products and vary greatly. The exact size, shape, material and surface properties determine whether a particle is safe or harmful, but the vast number of property combinations means that screening is extremely difficult," Priest said.

The scientists built upon previous research, which tested microfluidic screening processes for chemicals, such as potassium cyanide, cycloheximide and chemotherapy drugs. A major advantage of using microfluidic devices is their ability to carry out multiple tests using small sample volumes in a compact microchip format.

"Our results will help speed the development of microfluidic screening chips and, in time, may form the basis of standardized screening of new nanoparticles before they enter products or the environment," Priest said.

This research is expected to expedite toxicity testing of consumer personal products, as well as enhance safety and regulation on nanoparticles.

Powerful electronic components are indispensable for future communications, for the digital transformation of society and for artificial intelligence applications. On a footprint as small as possible, they should offer low energy consumption and achieve ever higher power densities, thus working more efficiently. This is where conventional devices reach their limits. Scientists all over the world are therefore investigating new materials and components that can meet these requirements. The Ferdinand-Braun-Institut (FBH) has now achieved a breakthrough with transistors based on gallium oxide (beta-Ga2O3).

The newly developed beta-Ga2O3-MOSFETs (metal-oxide-semiconductor field-effect transistor) provide a high breakdown voltage combined with high current conductivity. With a breakdown voltage of 1.8 kilovolts and a record power figure of merit of 155 megawatts per square centimeter, they achieve unique performance figures close to the theoretical material limit of gallium oxide. At the same time, the breakdown field strengths achieved are significantly higher than those of established wide bandgap semiconductors such as silicon carbide or gallium nitride.

In order to achieve these improvements, the FBH team tackled the layer structure and gate topology. The basis was provided by substrates from the Leibniz Institute for Crystal Growth with an optimized epitaxial layer structure. As a result, the defect density could be reduced and electrical properties improved. This leads to lower on-state resistances. The gate is the central 'switching point' of field effect transistors, controlled by the gate-source voltage. Its topology has been further optimized, allowing to reduce high field strengths at the gate edge. This, in turn, leads to higher breakdown voltages. The detailed results were published online on August 26, 2019 in the IEEE Electron Device Letters September issue.

A previously unknown electrical current develops in the body's cells when the vital fat pump function of the flippases transfers ("flips") lipids from the outer to the inner layer of the body's cell membranes. This electrical current may be important for a range of other cell mechanisms, and in this way also for human well-being and health.

This is shown by the basic research study 'Phosphatidylserine flipping by the P4-ATPase ATP8A2 is electrogenic'. Professor Jens Peter Andersen from the Department of Biomedicine at Aarhus University, Denmark, is one of the researchers behind the study. The article has recently been published in the journal PNAS.

"No one has previously envisaged that the flippases could create electrical current and in this way affect the functioning of the cells electrically, so this is entirely new knowledge. We don't yet have a comprehensive view of the possible consequences, but we think that via the electrical current the flippases also have an influence on many pumps and enzymes - and that they can thus have significance for our health that we've been unaware of before now," says Jens Peter Andersen.

In recent years it has become increasingly clear that the work of the flippases should not be underestimated. For example, it is well-documented that the flippases in the liver help to ensure bile transport, so that bile does not accumulate and ultimately break down the liver.

It is also known that dysfunctional flippases are connected to neurological diseases which lead to mental retardation and difficulty in walking. One example is CAMRQ (Cerebellar Ataxia, Mental Retardation and Disequilibrium syndrome), which can impact the sense of equilibrium to such a degree that a few years ago researchers reported on a Turkish family in which family members walked on all fours. Furthermore, some findings suggest that the flippases are also involved in Alzheimer's.

Flippases are a relatively young research field - very little was known about flippases 15 years ago. Jens Peter Andersen and his research group has during the last decade looked into a number of pathogenic mutations and they advanced a hypothesis for how the flippases would look and function already in 2014. This hypothesis has recently been confirmed.

Jens Peter Andersen has also headed a study of the functioning of the amino acids in the flippases, showing striking similarities between the flippases and the ion pumps in which Aarhus University has a proud Nobel Prize winning research tradition, which was founded by Jens Chr. Skou when he discovered a pumping function in the cells in the 1950s - the so-called sodium-potassium pump.

It was also these shared features between ion pumps, which transfer small ions, and flippases, which transfer relatively large fat molecules, that gave the researchers the idea for the newly published study:

"The comparison stimulated us to investigate whether the flippases has significance for the cell membranes' electrical potential in the same way as the ion pumps have," explains Jens Peter Andersen about the background for even thinking about measuring electrical discharge, which was done with the help of research partners from Italy.

"The next step will be to study how the flippases' ability to produce electrical current affects the other pumps, channels and enzymes in a cell membrane, and how possible mutations in the flippases can displace the electrical potential and lead to diseases," he says.

The next generation of waterproof smart fabrics will be laser printed and made in minutes. That's the future imagined by the researchers behind new e-textile technology.

Scientists from RMIT University in Melbourne, Australia, have developed a cost-efficient and scaleable method for rapidly fabricating textiles that are embedded with energy storage devices.

In just three minutes, the method can produce a 10x10cm smart textile patch that's waterproof, stretchable and readily integrated with energy harvesting technologies.

The technology enables graphene supercapacitors - powerful and long-lasting energy storage devices that are easily combined with solar or other sources of power - to be laser printed directly onto textiles.

In a proof-of-concept, the researchers connected the supercapacitor with a solar cell, delivering an efficient, washable and self-powering smart fabric that overcomes the key drawbacks of existing e-textile energy storage technologies.

The growing smart fabrics industry has diverse applications in wearable devices for the consumer, health care and defence sectors - from monitoring vital signs of patients, to tracking the location and health status of soldiers in the field, and monitoring pilots or drivers for fatigue.

Dr Litty Thekkakara, a researcher in RMIT's School of Science, said smart textiles with built-in sensing, wireless communication or health monitoring technology called for robust and reliable energy solutions.

"Current approaches to smart textile energy storage, like stitching batteries into garments or using e-fibres, can be cumbersome and heavy, and can also have capacity issues," Thekkakara said.

"These electronic components can also suffer short-circuits and mechanical failure when they come into contact with sweat or with moisture from the environment.

"Our graphene-based supercapacitor is not only fully washable, it can store the energy needed to power an intelligent garment - and it can be made in minutes at large scale.

"By solving the energy storage-related challenges of e-textiles, we hope to power the next generation of wearable technology and intelligent clothing."

The research analysed the performance of the proof-of-concept smart textile across a range of mechanical, temperature and washability tests and found it remained stable and efficient.

RMIT Honorary Professor and Distinguished Professor at the University of Shanghai for Science and Technology, Min Gu, said the technology could enable real-time storage of renewable energies for e-textiles.

"It also opens the possibility for faster roll-to-roll fabrication, with the use of advanced laser printing based on multifocal fabrication and machine learning techniques," Gu said.

In the context of progressing towards new targets for a post-2020 Global Biodiversity Framework, the debate remains on whether the emphasis should be on protected area coverage or protected area effectiveness. "It is worrying that we still know so little about how effective protected areas are, especially in relation to management inputs" says Dr. Johanna Eklund from the University of Helsinki.

A recent study she led compared common indicators of Protected Area Management Effectiveness, used by for example the Global Environmental Facility, WWF and other conservation actors, to satellite-based estimates of reduced deforestation in Madagascar. The international team found that overall protected areas were reducing deforestation within their borders, although variation in effectiveness existed, highlighting also clear needs for improvements. The variation, however, was not explained by management input assessments conducted following common global protocols and widely used by funders and non-governmental organizations.

"Self-reports of management effectiveness were generally good, with rather small differences between areas. Such lack of resolution may hinder the use of management-effectiveness indicators when identifying priorities for management investments at national level" says Dr Mar Cabeza from the University of Helsinki and co-author of the new study.

Nonetheless, the results, which were recently published in the scientific journal Conservation Science and Practice, also carry some good news: approximately half of the protected areas studied showed no deforestation at all inside their borders, and only three of the areas showed very high levels of deforestation. What is more, they also showed that 29 out of the 36 studied PAs had an impact in mitigating deforestation within their borders, i.e. without protecting these areas, the situation would have been much gloomier.

"It is inspiring to be able to report that conservation actions matter", says Dr Eklund. "Too much doom and gloom can passivate even the most enthusiastic of us; leading to despair and the feeling that both climate change and biodiversity loss are lost causes."

Not just paper parks

Tropical forests are of utmost importance for both biodiversity and climate change mitigation, yet under increased pressures to clear land for agriculture and production. One of the most widely used policy tools currently available to avert habitat loss and deforestation is the establishment of protected areas. However, previous research has highlighted that many protected areas are so-called paper parks, i.e. established on paper but lacking active management to ensure they have the capacity to mitigate threats.

This is why it is important to investigate how protected areas perform after they have been established. Why do some protected areas seem to be effective in avoiding high pressures of logging, whereas others cannot mitigate them?

Evaluating conservation actions

To find out the impact a conservation intervention or programme has had, there is a need to evaluate the outcomes compared to what the situation would have been had the intervention not taken place. "A bit similar as in medical science", says Dr Eklund, "where the effect of a pill or treatment is evaluated against a control group. The challenge in conservation science is that we often lack a suitable baseline to compare to; many protected areas have been established a long time ago and in areas of lower pressures, in order to avoid land conflicts in more productive landscapes. This needs to be accounted for in studies evaluating conservation effect."

Does management matter and how?

The team compiled unique data on management inputs and how this changed over time. They had access to information on how adequate levels of personnel and funding had been, how well different monitoring and enforcement strategies had been implemented, and how the collaboration with local communities and other stakeholders had developed. Surprisingly enough though, protected areas with higher management scores did not perform better in terms of avoiding deforestation. The assessment was only able to capture an extreme case where poor management was linked to a protected area showing increased deforestation, that is, even higher levels of deforestation than predicted. The authors suggest that one explanation for the general lack of correlation may be that management levels of the PAs in Madagascar were already at basic to sound levels and located in areas with low rates of forest loss, and therefore this set of PAs provides little variation with which to explore the effect of different levels of management. Moreover, previous studies have shown that local managers identify weak governance at the national level as an obstacle for effective management, suggesting the broader sociopolitical context might matter more than local management.

Policy implications

The results have policy implications both for Madagascar and internationally. The local conservation sector in Madagascar can use the results to prioritize key areas for development and target limited conservation resources to areas where they might make the biggest difference. The results are also of relevance for the post-2020 targets of the Convention on Biological Diversity. Dr Eklund hopes that different measures of effectiveness, not merely an increase in protected area coverage, would be better incorporated into the wording of the new targets. "Continued efforts to carry out quantitative impact evaluations of protected area effectiveness, and collection of management effectiveness data, are needed, as our study shows that they can complement each other in displaying different facets of how PAs perform", concludes Dr Eklund.

A group of biologists from Hong Kong Baptist University (HKBU) have discovered a new fireworm species in Hong Kong waters and named it Chloeia bimaculata. It is the fourth named species to be added to the fireworm genus Chloeia during the last century. The team also identified Chloeia parva as the fireworm species that caused the outbreak in Hong Kong last year. The discovery shows how little people know about the biodiversity of this group of animals.

Fireworms are common in tropical and subtropical shallow-water ecosystems. They are members of the polychaete worm family Amphinomidae. "Poly" in the word polychaete means "many", while "chaete" means "hairs" or "bristles". Each body segment of a fireworm has a pair of fleshy outgrowths that bear many chaetae. These chaetae contain neurotoxins that can produce a painful burning sensation around the area of contact with human skin.

In Hong Kong, individual fireworms have often been sighted underwater by divers, but since last summer swarms of them have been seen near swimming beaches in Tuen Mun and Tsuen Wan, threatening many beachgoers.

Prompted by the recent outbreak of fireworms, Professor Qiu Jianwen, Associate Head and Professor of the HKBU Department of Biology, and his research team collected specimens from local swimming beaches and shallow-water sandy bottoms. Through detailed studies, the team reported Chloeia bimaculata, a new fireworm species.

New fireworm species named from its black spots

The HKBU team collected the undescribed fireworm specimens from the sandy bottom of a coral community in Sharp Island, Sai Kung. These specimens are fusiform in shape, measuring 28 mm to 39 mm long and 7 mm to 14 mm wide, with around 30 segments. They can be distinguished by the specific colour pattern on their mid-dorsum.

Professor Qiu named this fireworm species Chloeia bimaculata. He said: "This is the first time that Chloeia bimaculata has been identified. Bimaculata means two black spots in Latin. We gave it this name because each segment of their body has two dark spots arranged one behind the other."

Based on the photos of fireworms posted on the internet by some local scuba divers, the team believes that this species has been recorded at other eastern Hong Kong locations before, including the waters around Tung Ping Chau.

Identifying the culprits behind the recent outbreaks

The team also collected fireworm specimens from two beaches in Tsuen Wan, and the subtidal waters of Tolo Harbour during an outbreak in June 2018 in Hong Kong. To identify these species, the team borrowed the type specimen deposited in the Natural History Museum in London for examination. Even though the main body of the type specimen is missing, based on the morphology of the chaetae and cirri on a parapodium (foot), the team could still recognise that the specimens collected in Hong Kong during the outbreak are Chloeia parva, a species named in 1868.

The research team also found that the original specimen record states that "along the centre of the back (of Chloeia parva), on each segment, there is a dark mark in the shape somewhat of the Greek 'Y' shaped pigmentation". This also matches the pigmentation pattern of the specimens they collected during the outbreak.

Chloeia parva are fusiform in shape, measuring 38 mm to 97 mm long and 8 mm to 20 mm wide, excluding chaetae. The team believes that Chloeia parva are widespread in the South China Sea.

"By describing a new fireworm species and re-describing a poorly characterised fireworm species found in Hong Kong waters, it lays the foundation for further studies of fireworms, as well as other polychaete worms," said Professor Qiu.

"There are around 6,000 recorded marine species in Hong Kong. Further discovery of a new marine species shows that the biodiversity of Hong Kong is rich and more species await discovery," he added.

Around the world, there are 28 recognised fireworm Chloeia species. Among them, two species, including Chloeia bimaculata, have been confirmed to exist in Hong Kong by this HKBU research. Polychaetes are common animals in various types of ecosystems, including coral reefs, mangrove forests and the muddy seabed. They play a vital role in marine food chains.

PITTSBURGH (Aug. 27, 2019) -- As recreational marijuana legalization becomes more widespread throughout the U.S., so has concern about what that means for enforcing DUI laws. Unlike a breathalyzer used to detect alcohol, police do not have a device that can be used in the field to determine if a driver is under the influence of marijuana. New research from the University of Pittsburgh is poised to change that.

An interdisciplinary team from the Department of Chemistry and the Swanson School of Engineering has developed a breathalyzer device that can measure the amount of tetrahydrocannabinol (THC), the psychoactive compound in marijuana, in the user's breath. Current drug testing methods rely on blood, urine or hair samples and therefore cannot be done in the field. They also only reveal that the user has recently inhaled the drug, not that they are currently under the influence.

The breathalyzer was developed using carbon nanotubes, tiny tubes of carbon 100,000 times smaller than a human hair. The THC molecule, along with other molecules in the breath, bind to the surface of the nanotubes and change their electrical properties. The speed at which the electrical currents recover then signals whether THC is present. Nanotechnology sensors can detect THC at levels comparable to or better than mass spectrometry, which is considered the gold standard for THC detection.

"The semiconductor carbon nanotubes that we are using weren't available even a few years ago," says Sean Hwang, lead author on the paper and a doctoral candidate in chemistry at Pitt. "We used machine learning to 'teach' the breathalyzer to recognize the presence of THC based on the electrical currents recovery time, even when there are other substances, like alcohol, present in the breath."

Hwang works in the Star Lab, led by Alexander Star, PhD, professor of chemistry with a secondary appointment in bioengineering. The group partnered with Ervin Sejdic, PhD, associate professor of electrical and computer engineering at the Swanson School of Engineering, to develop the prototype.

"Creating a prototype that would work in the field was a crucial step in making this technology applicable," says Dr. Sejdic. "It took a cross-disciplinary team to turn this idea into a usable device that's vital for keeping the roads safe."

The prototype looks similar to a breathalyzer for alcohol, with a plastic casing, protruding mouthpiece, and digital display. It was tested in the lab and was shown to be able to detect the THC in a breath sample that also contained components like carbon dioxide, water, ethanol, methanol, and acetone. The researchers will continue to test the prototype but hope it will soon move to manufacturing and be available for use.

"In legal states, you'll see road signs that say "Drive High, Get a DUI,' but there has not been a reliable and practical way to enforce that," says Dr. Star. "There are debates in the legal community about what levels of THC would amount to a DUI, but creating such a device is an important first step toward making sure people don't partake and drive."

DURHAM, N.C. - A specific gene associated with autism appears to undergo changes in the sperm of men who use marijuana, according to new research from Duke Health.

The gene change occurs through a process called DNA methylation, and it could potentially be passed along to offspring.

Publishing online Aug. 27 in the journal Epigenetics, the researchers said the findings do not establish a definitive link between cannabis use and autism, but the possible connection warrants further, urgent study, given efforts throughout the country to legalize marijuana for recreational and/or medicinal uses.

"This study is the first to demonstrate an association between a man's cannabis use and changes of a gene in sperm that has been implicated in autism," said senior author Susan Murphy, Ph.D., associate professor in the Department of Obstetrics & Gynecology at Duke University School of Medicine.

Murphy and colleagues, including lead author and Ph.D. student Rose Schrott, conducted studies using human biologics and animal models to analyze differences between the sperm of males who smoked or ingested marijuana compared to a control group with no such exposures.

In earlier work, published in December, the researchers noted several gene alterations in the sperm of men who smoke marijuana. The current study homed in on specific genes, notably one called Discs-Large Associated Protein 2, or DLGAP2. This gene is involved in transmitting neuron signals in the brain and has been strongly implicated in autism, as well as schizophrenia and post-traumatic stress disorder.

"We identified significant hypomethylation at DLGAP2 in the sperm of men who used marijuana compared to controls, as well as in the sperm of rats exposed to THC compared to controls," Schrott said. "This hypomethylated state was also detected in the forebrain region of rats born to fathers exposed to THC, supporting the potential for intergenerational inheritance of an altered sperm DNA methylation pattern."

The Duke team found that there was a sex-based difference in the relationship between DNA methylation and gene expression in human brain tissues. In both male and female brain tissues, increased DNA methylation was associated with decreased gene activity. This relationship was strongest in females, and seemed to be less well maintained in males, though the reason for this is unknown at this time. This anomaly was notable, because the ratio of boys to girls with autism is 4:1, and there are sex differences in the neurobehavioral symptoms.

"It's possible that the relationship between methylation and expression is modified if the methylation change we see in sperm is inherited by the offspring," Murphy said. "In any event, it's clear that the region of DNA methylation within DLGAP2 that is altered in association with cannabis use is functionally important in the brain."

Murphy said the study's sample size was small -- including 24 men, half who used marijuana and half who didn't -- and could not account for confounding factors such as diet, sleep and exercise, but the findings should prompt continued research.

"Given marijuana's increasing prevalence of use in the U.S. and the increasing numbers of states that have legalized its use, we need more studies to understand how this drug is affecting not only those who smoke it, but their unborn children," Murphy said. "There's a perception that marijuana is benign. More studies are needed to determine whether that is true."

Think of a memory from your childhood. Are you seeing the memory through your own eyes, or can you see yourself, while viewing that child as if you were an observer?

"If memory was simply an exact recollection of our experiences, one would think that we would recall our early memories from the first-person perspective," said Peggy St Jacques, assistant professor in the Faculty of Science's Department of Psychology. "Recalling a memory is not like watching a film of what happened. We edit and modify memories each time we recall them."

The perspective through we which recall our memories--either seeing it through our own eyes in the first person, or viewing as an observer in the third person--can have an effect on the vividness and potency of the memory, with stronger recollection when perceived in the first person.

"A number of studies have shown that this can impact how we later recall these memories," said St Jacques, who recently authored a paper exploring this phenomenon. "Viewing memories in the third person tends to reduce the vividness of that experience, as well as the amount of emotion that we feel. Our memory system is very dynamic and flexible."

And that's probably a good thing, St Jacques explained. Our ability to edit our memories allows us to grow and change how we perceive both ourselves and our experiences. For example, by changing the way we feel about a troubling memory, we're able to learn and move forward, helping those suffering post-traumatic stress disorder as just one example.

So, the next time you recall a memory in the third person, ask yourself if that memory is real or not. "It's possible because you're not recalling that experience through your own eyes that the memory is distorted in some way," she said. "There could be some aspects that are false or edited."

Using virtual reality

But if our memories are influenced by the perspective we use to recall them, what does that mean for experiences we see for the first time in third-person? That's one question that St Jacques is further exploring--using virtual reality technology.

"Virtual reality allows us to have immersive experiences that seem really real to us but that we experience in the third person," she said. "In our lab, we're using virtual reality to look at how the experience of virtual environments in first- and third-person impact people's memories. Our working hypothesis is that, after a delay, if you've formed memories from a third-person perspective, that the memory will not be as durable and will tend to lose vividness over time."

SAN DIEGO, Aug. 27, 2019 -- A major challenge for cancer surgeons is to determine exactly where a tumor starts and where it ends. Removing too much tissue can impair normal functions, but not taking enough can mean the disease could recur. The "MasSpec Pen," a handheld device in development, could someday enable surgeons to distinguish between cancerous and healthy tissue with greater certainty in seconds, while in the operating room. Today, researchers report first results of its use in human surgeries.

The researchers will present their findings at the American Chemical Society (ACS) Fall 2019 National Meeting & Exposition. ACS, the world's largest scientific society, is holding the meeting here through Thursday. It features more than 9,500 presentations on a wide range of science topics.

"It's been shown with extensive clinical data that highly effective surgeries are those that remove the most cancer, but also preserve the most normal tissue," says principal investigator Livia Eberlin, Ph.D. "We created the MasSpec Pen because we thought it would be incredible if there was a technology that could actually provide molecular information right in the operating room in living tissues within a time frame that could expedite surgical decisions."

Surprisingly, the most common method that medical professionals currently use to determine tumor margins or verify a diagnosis is 100 years old: histopathology. With this technique, a tissue sample is extracted during surgery and taken to a laboratory. The sample is flash-frozen, sectioned, stained and examined with a microscope. In total, this procedure can take an average of 30 minutes. Meanwhile, the patient, who is still under anesthesia, and the surgeon are left waiting. In addition, while histopathology is effective for many surgeries, especially for cancers, the process can be subjective because artifacts from the freezing process can complicate interpretation, Eberlin explains.

To overcome these challenges, Eberlin and colleagues at the University of Texas at Austin developed the MasSpec Pen, a handheld and biocompatible device connected to a high-performance mass spectrometer. The device rapidly identifies the molecular profile of tissue exposed during a surgery by first depositing a small droplet of water on the tissue surface for about three seconds. Next, the droplet is transferred to the mass spectrometer, where molecules from the tissue are identified. Finally, machine learning algorithms comb through the molecular information and provide a predictive diagnosis that surgeons can act on.

"We have developed the MasSpec Pen so that the surgeon just has to touch the tissue with the pen, and trigger the system with a foot pedal," Eberlin says. "From there, everything is coded and automated so that the whole process is completed in under 10 seconds." A video of the device in action is posted here.

So far the MasSpec Pen has been tested on more than 800 human tissues ex vivo, including normal and cancerous breast, brain, pancreatic, thyroid, lung and ovarian tissues. The team is now testing the MasSpec Pen in vivo, in an ongoing clinical study at the Texas Medical Center with human patients during thyroid, breast and pancreatic cancer surgeries. Freshly excised patient tissue also is being analyzed and is showing promising results.

"We are continuing research and development of this technology in my lab by continuing to improve our technology and validating its performance across different cancer types," Eberlin says. "We are also exploring new applications in surgery including minimally invasive surgical procedures, as well as outside the operating room in forensics and agricultural applications."

Researchers at the University of Waterloo have developed a way to better harness the volume of energy collected by solar panels.

In a new study, the researchers developed an algorithm that increases the efficiency of the solar photovoltaic (PV) system and reduces the volume of power currently being wasted due to a lack of effective controls.

"We've developed an algorithm to further boost the power extracted from an existing solar panel," said Milad Farsi, a PhD candidate in Waterloo's Department of Applied Mathematics. "Hardware in every solar panel has some nominal efficiency, but there should be some appropriate controller that can get maximum power out of solar panels.

"We do not change the hardware or require additional circuits in the solar PV system. What we developed is a better approach to controlling the hardware that already exists."

The new algorithm enables controllers to better deal with fluctuations around the maximum power point of a solar PV system, which have historically led to the wasting of potential energy collected by panels.

"Based on the simulations, for a small home-use solar array including 12 modules of 335W, up to 138.9 kWh/year can be saved," said Farsi, who undertook the study with his supervisor, Professor Jun Liu of Waterloo's Department of Applied Mathematics. "The savings may not seem significant for a small home-use solar system but could make a substantial difference in larger-scale ones, such as a solar farm or in an area including hundreds of thousands of local solar panels connected to the power grid.

"Taking Canada's largest PV plant, for example, the Sarnia Photovoltaic Power Plant, if this technique is used, the savings could amount to 960,000 kWh/year, which is enough to power hundreds of households. If the saved energy were to be generated by a coal-fired plant, it would require emission of 312 tonnes of CO2 into the atmosphere."

Milad further pointed out that the savings could be even more substantial under a fast-changing ambient environment, such as Canadian weather conditions, or when the power loss in the converters due to the undesired chattering effects seen in other conventional control methods is taken into account.

Men are typically described by words that refer to behavior, while adjectives ascribed to women tend to be associated with physical appearance. This, according to a group of computer scientists from the University of Copenhagen and other universities that deployed machine learning to analyze 3.5 million books.

'Beautiful' and 'sexy' are two of the adjectives most frequently used to describe women. Commonly used descriptors for men include 'righteous', 'rational' and 'brave'.

A computer scientist from the University of Copenhagen, along with fellow researchers from the United States, trawled through an enormous quantity of books in an effort to find out whether there is a difference between the types of words used to describe men and women in literature. Using a new computer model, the researchers analyzed a dataset of 3.5 million books, all published in English between 1900 to 2008. The books include a mix of fiction and non-fiction literature.

"We are clearly able to see that the words used for women refer much more to their appearances than the words used to describe men. Thus, we have been able to confirm a widespread perception, only now at a statistical level," says computer scientist and Assistant Professor Isabelle Augenstein of the University of Copenhagen's Department of Computer Science.

The researchers extracted adjectives and verbs associated with gender-specific nouns (e.g. 'daughter' and 'stewardess'). For example, in combinations such as 'sexy stewardess' or 'girls gossiping'. They then analysed whether the words had a positive, negative or neutral sentiment, and subsequently which categories the words could be divided into.

Their analyses demonstrate that negative verbs associated with body and appearance are used with five times the frequency for females than males. The analyses also demonstrate that positive and neutral adjectives relating to the body and appearance occur approximately twice as often in descriptions of females, while males are most frequently described using adjectives that refer to their behaviour and personal qualities.

In the past, linguists typically looked at the prevalence of gendered language and bias, but using smaller data sets. Now, computer scientist are able to deploy machine learning algorithms to analyze vast troves of data - in this case, 11 billion words.

New life for old gender stereotypes

Although many of the books were published several decades ago, they still play an active role, points out Isabelle Augenstein. The algorithms used to create machines and applications that can understand human language are fed with data in the form of text material that is available online. This is the technology that allows smartphones to recognize our voices and enables Google to provide keyword suggestions.

"The algorithms work to identify patterns, and whenever one is observed, it is perceived that something is 'true'. If any of these patterns refer to biased language, the result will also be biased. The systems adopt, so to speak, the language that we people use, and thus, our gender stereotypes and prejudices," says Isabelle Augenstein, and gives an example of where it may be important:

"If the language we use to describe men and women differs, in employee recommendations for example, it will influence who is offered a job when companies use IT systems to sort through job applications."

As artificial intelligence and language technology become more prominent across society, it is important to be aware of gendered language.

Augenstein continues: "We can try to take this into account when developing machine-learning models by either using less biased text or by forcing models to ignore or counteract bias. All three things are possible."

The researchers point out that the analysis has its limitations, in that it does not take into account who wrote the individual passages and the differences in the degrees of bias depending on whether the books were published during an earlier or later period within the data set timeline. Furthermore, it does not distinguish between genres - e.g. between romance novels and non-fiction. The researchers are currently following up on several of these items.

Nanoparticles are smaller than five nanometres - a nanometre being one millionth of a millimetre - which corresponds approximately to the size of macromolecules. Such tiny particles are very easily absorbed in body cells. There are two aspects to this feature. Firstly, it makes nanoparticles good vehicles for transporting a broad range of compounds or substances attached to them into normal diseased cells in a targeted manner.

On the other hand, they can also pose health risks, for example in connection with particulate matter. One of the ways that particulate matter is created is in combustion processes, and part of that can be classified as nanoparticles. These extremely small particles can overcome the blood-air barrier and penetrate the body: The bronchial mucosa in the lungs doesn't filter out the particles. Instead, they make their way into the pulmonary alveoli and from there into the bloodstream.

Together with work groups from the Chemistry department, HHU researchers from the Institute of Experimental Condensed Matter Physics working under Prof. Dr. Thomas Heinzel and from the Department of Haematology, Oncology and Clinical Immunology working under Prof. Dr. Rainer Haas have now studied what happens when body cells absorb such nanoparticles. The researchers used nanoparticles made from graphene; this is a special form of carbon that comprises two-dimensional layers of hexagonal carbon rings. They added these to special haematopoietic stem cells referred to as CD34+ stem cells. These cells are particularly sensitive to damaging environmental influences on account of their ability to divide throughout their lifespan. The assumption is that these cells would be damaged more by nanoparticles - if at all - than the more robust other cell types.

The interdisciplinary team of researchers based in Düsseldorf was able to demonstrate that the carbon nanoparticles get into the cells, where they are encapsulated in special organelles called lysosomes. The lysosomes serve as a type of waste removal unit for the body where foreign bodies accumulate and are normally broken down with the help of enzymes. However, the researchers didn't observe any such process over the duration of the experiments, which lasted for several days.

When comparing the active genes ("gene expression") of stem cells with and without the addition of nanoparticles, the researchers found that only one of a total of 20,800 recorded expressions had changed; minor effects were determined in a further 1,171 gene expressions.

Prof. Heinzel had this to say regarding the findings: "Encapsulation of the nanoparticles in the lysosomes ensures that these particles are stored securely at least for a few days - for the duration of our experiments - and cannot damage the cell. This means the cell remains viable without any major change in gene expression." This insight is important if nanoparticles are to be used to deliver drugs into the cell. The experimental framework used here does not allow for any long-term statements to be made regarding any increased probability of cell mutation resulting in cancer.

The research was carried out as a close collaboration between HHU's Faculty of Mathematics and Natural Sciences and Faculty of Medicine and University Hospital Düsseldorf. Düsseldorf School of Oncology (headed up by Prof. Dr. Sebastian Wesselborg) funded the doctoral scholarship of first author Stefan Fasbender. Prof. Haas said: "The proximity of the Hospital and the University and their close links in terms of content provides HHU with a particularly fruitful environment for translational research, where insights and expertise from basic research are combined with aspects relevant to treatment."