Brain

From microscopes to data transfer via optical fibres all the way to modern quantum technologies, light plays an important role in science and industry. Particularly methods for changing the colour - and hence the frequency and wavelength - of light are of great importance in modern applications. Those methods require the use of nonlinear crystals. In such crystals, two photons of a particular frequency can, for instance, be turned into one photon having twice that frequency - say, two red ones into a single blue one.

For that to work, however, the light typically has to hit the crystal in a specific direction and with a specific polarization. This so-called phase matching often severely limits practical applications. A team of researchers led by ETH professor Rachel Grange at the Institute for Quantum Electronics, together with the group of Lucio Isa at the Department of Materials, have now developed a method by which efficient frequency doubling can be obtained without such fine tuning, and which also has other advantages compared to conventional methods.

Seemingly irreconcilable approaches

The researchers' recipe can be roughly summarized like this: rather small than large, and a mess is better than order. That sounds mysterious, but the task that Grange's team had set themselves was an equally big riddle: "For a better and more widely applicable frequency doubling, we wanted to combine two approaches that don't really fit together", says Romolo Savo, who led the project as a postdoc in the framework of a Marie- Sk?odowska-Curie fellowship.

In the first approach, instead of a single large crystal one uses an assembly of lots of mini-crystals whose individual crystal axes point in random directions. In that way, it is no longer necessary to strictly control the directions of the incoming light beams. Among the many mini-crystals there will be some that are oriented favourably and some that are oriented unfavourably, but overall they will always produce a significant amount of frequency-doubled light. "It sounds counterintuitive", Savo admits, "and some of our colleagues were truly puzzled by the idea of using disorder in that way - but it works!"

The second approach is based on the enhancing action of resonances. If the assembly of mini-crystals is spherical, for instance, with a diameter roughly equal to the wavelength of the light, the intensity inside the sphere is increased manifold by repeated reflection of the light waves from the walls of the sphere, and hence also the yield of frequency doubled light. Therefore, to make optimal use of both effects at the same time the researchers wanted to mould a disordered crystalline powder into micrometre-sized spheres in order to exploit the resonant enhancement of the light. The individual barium titanate crystals they intended to use for that purpose had to be very small, only around 50 nanometres in size, so that they were transparent enough to allow light to pass through them many times and thus create resonances in the microspheres.

A tip during the coffee break

„So, we had this great idea, but no clue as to how to turn the many tiny nanocrystals into perfect microspheres", says Savo. "Then, one day, we met Lucio Isa during the coffee break and told him about our problem - and he had an idea for us right there." Isa's suggestion was to dissolve the nanocrystal powder in water, mix the solution with oil, and finally shake everything vigorously - similarly to what one would do with a vinaigrette made from vinegar and oil. Inside the emulsion created by that process, tiny bubbles of the water-crystal solution will then form, from which the water gradually evaporates through the oil. In the end, tiny, perfectly shaped spheres of disordered nanocrystals remain, which is exactly what Grange and her collaborators were after. "From that tip, the collaboration with Isa's group started", says Grange: "Incidentally, such spontaneous collaborations, which haven't been planned beforehand, are often the most fruitful. Of course, we immediately tried Isa's recipe."

Versatility plus material savings

And the recipe worked - even better than one might expect. "The frequency doubling with the tiny spheres made of disordered nanocrystals works independently of the direction of the incoming light as well as over a wide range of frequencies. This makes it much more versatile than frequency doubling with conventional crystals", Savo explains. On top of that, the researchers obtained the same yield of frequency-doubled light using 70% less material. Contrary to ordinary crystals, for which the light yield stops growing beyond a certain size, it continued to increase with the volume of the microspheres.

High-quality laser crystals from powder

Grange and her colleagues now want to further improve their method, for instance by adding a spacer between the microspheres and the glass slide on which they rest. This should minimize light losses. The researchers have also started thinking about possible applications. The prospect of producing high-performance nonlinear crystals from a simple and inexpensive nanocrystal powder is interesting for laser technologies in general. Also, it is possible to spread the microspheres over large areas. This could lead to the production of a new type of display that directly converts images in the infrared range into visible images by frequency doubling. Such displays could then be used in cameras for security and life-science applications.

Steam-assisted oil extraction methods for heavy deposits have long been the focus of attention at Kazan Federal University. In particular, much attention is paid to in-situ combustion catalysts.

One of the latest research projects is dedicated to iron-containing catalysts including mixed Fe(II, III) oxides. The compounds are studied by Mossbauer spectroscopy.

"Mössbauer spectroscopy is based on the emission or absorption of gamma quanta in a solid without energy loss. In this work, Mössbauer spectroscopy helped determine the phase composition of catalyst particles before and after thermal steam exposure," says co-author Irek Mukhamatdinov.

The extreme sensitivity of Mossbauer spectroscopy is very conducive to the analysis of iron-containing compounds.

As a result, phase conversions of the oxides were studied. "In the oil industry, Mossbauer spectroscopy is often used to find out the scale of de-copperization of oil under the influence of a catalyst," adds co-author Aliya Khaidarova.

The conversion degree of the compounds increased as the duration of the experiment increased, which indicates that the disperse iron compounds participate multiple times in the cleavage of chemical bonds. Results of Mossbauer spectroscopy indicate that maghemite is reduced to magnetite when the iron oxides react with water vapor during the catalytic aquathermolysis of crude oil at 250°C.

In 2015, the New Horizons space probe discovered spectacular snowcapped mountains on Pluto, which are strikingly similar to mountains on Earth. Such a landscape had never before been observed elsewhere in the Solar System. However, as atmospheric temperatures on our planet decrease at altitude, on Pluto they heat up at altitude as a result of solar radiation. So where does this ice come from? An international team led by CNRS scientists* conducted this exploration. They first determined that the "snow" on Pluto's mountains actually consists of frozen methane, with traces of this gas being present in Pluto's atmosphere, just like water vapour on Earth. Then, to understand how the same landscape could be produced in such different conditions, they used a climate model for the dwarf planet, which revealed that due to its particular dynamics, Pluto's atmosphere is rich in gaseous methane at altitudes. As a result, it is only at the peaks of mountains high enough to reach this enriched zone that the air contains enough methane for it to condense. At lower altitudes the air is too low in methane for ice to form. This research, published in Nature Communications, could also explain why the thick glaciers consisting of methane observed elsewhere on Pluto bristle with spectacular craggy ridges, unlike Earth's flat glaciers, which consist of water.

*- Scientists from the IPSL Dynamic Meteorology Laboratory (CNRS / Sorbonne Université / École polytechnique / ENS Paris), the Institute for Planetary Sciences and Astrophysics of Grenoble (CNRS / Université Grenoble Alpes), the NASA Ames Research Center, and the Lowell Observatory (Unite States) took part in this research.

When residential fires happen at night while families are sleeping, deaths are more likely to occur. Smoke alarms are important for preventing these deaths, yet research has shown that many pre-teenage children don't wake up to traditional high-frequency tone alarms. Researchers from the Center for Injury Research and Policy and the Sleep Disorders Center at Nationwide Children's Hospital conducted a series of studies to identify smoke alarm signals that would more effectively awaken children and other members of the household in the event of a fire.

In a recent study published online in Pediatric Research, researchers examined four different smoke alarms to determine which ones worked best to wake children from deep sleep and prompt them to perform an escape procedure: a male voice, female voice, combination of a low-frequency tone plus a female voice (hybrid alarm), or high-frequency tone. The research included 188 children age 5 to 12 years old studied at a sleep research center in Columbus, Ohio. The effectiveness of a male voice alarm had been previously tested among sleeping older adults but not among children.

The researchers found that the male voice, female voice, and hybrid voice-tone alarms awakened 85-89% of children and prompted 84-89% to "escape" from the bedroom, compared with 56% awakened and 55% escaped for the high-frequency tone alarm.

In a real fire, there is a narrow window of time for everyone to get out of the burning building. If a child takes too long to wake up and escape, serious injuries or death could occur. In this study, the median time to escape for the male voice, female voice, and hybrid voice-tone alarms was 12-13 seconds, whereas it was more than a minute and a half - 96.5 seconds - for the high-frequency tone alarm. The study authors concluded that there were no significant differences in the effectiveness of the male voice, female voice, or hybrid alarms when compared with each other, and that they all out-performed the high-frequency tone alarm. When used in children's sleep areas, the male voice, female voice, or hybrid alarms may reduce residential fire-related injuries and deaths among children old enough to perform self-rescue.

"Children are remarkably resistant to awakening by sound when asleep," said Mark Splaingard, MD, co-author of the study and director of the Sleep Disorders Center at Nationwide Children's. "Children sleep longer and deeper than adults and require louder sounds to awaken than adults, which means they are less likely to awaken and escape a nighttime home fire. The fact that we were able to find a smoke alarm sound that reduces the amount of time it takes for many children to wake up and leave the bedroom could save lives."

This was the fourth study in a series looking at children's responses to various types of non-traditional smoke alarms. The original study in 2006 tested the concept of using the mother's voice to wake children from deep sleep and prompt their "escape." It demonstrated that the alarm was effective, but researchers needed to figure out what component of the alarm's signal was responsible for success: the use of a child's first name in the voice message, specifically the mother's voice (vs. any human voice), or the frequency of the signal.

A study published in 2019 tested mother's voice smoke alarms that did and did not include the use of the child's first name in the message; these alarms were compared with each other and to a high-frequency tone alarm. Researchers found that a sleeping child was about three times more likely to be awakened by one of the three mother's voice alarms than by the tone alarm. The median time to escape for the high-frequency tone alarm was 282 seconds - nearly five minutes - while the median times to escape for the mother's voice alarms ranged from 18 to 28 seconds. Importantly, no significant differences were found between each pair of the voice alarms, regardless of whether the child's name was included in the message. Therefore, personalizing the alarm message with the child's first name did not increase alarm effectiveness, which simplifies the development of an effective and practical smoke alarm for sleeping children.

A study published in 2020 tested four smoke alarm signals: the voice of the child's mother, the voice of a female stranger, a low-frequency tone, and a high-frequency tone. The two voice alarms and low-frequency tone alarm significantly out-performed the high-frequency tone alarm, with the low-frequency tone alarm and female stranger's voice alarm performing best. This confirmed that a generic female voice worked as well as the mother's voice, again simplifying the development of an effective smoke alarm for sleeping children.

While having an alarm that wakes children is important, it also needs to wake the adults in the home. A fifth study, recently published in Injury Epidemiology, evaluated whether the alarms that are effective in awakening children and prompting their escape were also effective among adults 20-49 years old. Almost all (149 of 150) adults awakened and performed the escape procedure to all four alarms (female voice, male voice, low-frequency tone, and high-frequency tone). The median time to awaken was two seconds for the high-frequency tone alarm and one second for the other three alarms. The median time to escape for the high-frequency tone alarm was 12 seconds, compared with 10 seconds for the low-frequency tone alarm and nine seconds each for the female and male voice alarms.

"Our research demonstrates that smoke alarms developed for the unique developmental requirements of sleeping children are also effective among sleeping adults," said Gary Smith, MD, DrPH, lead author of these studies and director of the Center for Injury Research and Policy at Nationwide Children's Hospital. "Switching from the use of a high-frequency tone alarms that many people currently have in their homes to a smoke alarm that uses a low-frequency tone, male or female voice, or a voice-low-frequency tone hybrid signal may reduce residential fire-related injuries and deaths among sleeping children old enough to perform self-rescue, while also successfully alerting sleeping adult members in the household."

Future research will test these children's smoke alarms to ensure they are effective in waking older adults. However, previous research suggests that they should respond at least as well as adults younger than 65 years of age.

When it is time to replace your alarms, it is recommended that you choose one of the alarms shown by these studies to work with children and other age groups. The low frequency tone alarm is currently available on the market and has been approved for use in residences in the US Fire Code. Current recommendations are to install a smoke alarm on every level of the home, even in the basement. Install a smoke alarm outside every sleeping area. For the best protection, install a smoke alarm inside each bedroom as well. For more information about smoke alarms, click here.

Both a mother's and father's mental health are associated with increased risk that their baby will be born premature, a new study has found.

The research, led by the Murdoch Children's Research Institute (MCRI) and published in EClinicalMedicine, found men with persistent mental health problems through adolescence and young adulthood were more likely to have a baby born premature. Women with anxiety and depression during pregnancy were more likely to have a preterm birth.

Study co-lead MCRI'S and Deakin University's Dr Elizabeth Spry said prior to this study the impact of maternal and paternal mental health history on offspring preterm birth and birth weight was unknown.

The study involved 398 women and 267 men from the Victorian Intergenerational Health Cohort Study (VIHCS), who were assessed over 15 years for anxiety and depressive symptoms from adolescence to young adulthood and during subsequent pregnancies.

Dr Spry said that fathers were often neglected in research on children's early growth and development.

"We found that men with persistent mental health symptoms in the decades leading up to pregnancy were more likely to have premature babies. Our study joins growing evidence of the important role that fathers play in the health and development of their children, and suggests that these links begin well before babies are conceived," she said.

"Most research on children's early development has focused on mums. This means that public health recommendations are also almost entirely focused on what mums should and shouldn't do when planning pregnancy or having a child. In contrast, men receive very little guidance or support."

Study co-lead, King's College London's Dr Claire Wilson, said understanding how mental health problems starting in adolescence affect birth outcomes could open up new opportunities for the prevention of premature birth.

"Mental health may affect parental reproductive biology and antenatal pathways and can have an impact on genetic and environmental influences such as substance use and nutrition, which could be linked to a baby's development," she said.

"Pre-term birth is common and is a leading cause of infant deaths worldwide, but the underlying causes have been largely unknown. Early and mid-late preterm birth can carry lifelong effects on health and development such as visual and hearing impairments and poor health and growth."

MCRI Professor George Patton said the findings further strengthened the need for expanding preconception mental health care to both men and women, prior to them becoming parents.

"The findings emphasise a need for coordinated care between child and adolescent, adult and specialist perinatal health services," he said.

"Intervention in adolescence is likely to yield benefits not only for parents' own continuing mental health, but also for their child's development, both by reducing the risk of premature birth and promoting positive engagement and nurturing care across the early years of life."

Professor Patton said prospective parent's mental health had also suffered during COVID-19 and the subsequent lockdowns.

"Rates of anxiety and depression have risen markedly in adolescents and young adults across the course of the pandemic," he said. "Many problems will resolve but there is a possibility that some will continue given ongoing economic disruption and unemployment. More than ever, we need research to track young parents through their pregnancies and beyond."

The hospitalization rate for acute cardiovascular disease (CVD) events in a large southern California health system was 1.62 times higher in the two days immediately after the 2016 presidential election when compared with the same two days in the week prior to the 2016 election, according to new research from Harvard T.H. Chan School of Public Health and Kaiser Permanente. The results were similar across sex, age, and race and ethnicity groups, and the findings suggest that sociopolitical stress may trigger CVD events.

The findings were published in the Proceedings of National Academy of Sciences on October 12, 2020.

"This is a wake-up call for every health professional that we need to pay greater attention to the ways in which stress linked to political campaigns, rhetoric and election outcomes can directly harm health," says David Williams, Florence Sprague Norman and Laura Smart Norman Professor of Public Health at Harvard Chan School and corresponding author of the study.

Previous research has shown that there is an increased risk of acute CVD events soon after significant population-based events such as earthquakes, industrial accidents, terror attacks, and even sporting events. The American Psychological Association has recently noted that a large portion of adults consider the current political climate as a significant source of stress, though little is known about how that stress may impact health.

For this study, researchers analyzed data collected by Kaiser Permanente Southern California, an integrated health system that provides care to 4.6 million people in the region. They focused on diagnoses of acute myocardial infarction and stroke among adults, as well as emergency department diagnoses for chest pain and unstable angina. In the two days immediately after the 2016 presidential election, the rate of hospitalizations for CVD events was 573.14 per 100,000 person years (or 94 total hospitalizations), compared with a rate of 353.75 per 100,000 person years (or 58 total hospitalizations) in the same two days of the week in the week prior to the election.

"In our diverse patient population that is reflective of Southern California as a whole, we saw that the risk of heart attacks increased after the 2016 election irrespective of sex, age, and racial/ethnic groups," said the study's lead researcher, Matthew Mefford of the Kaiser Permanente Southern California Department of Research & Evaluation. "It is importa

The lithium batteries that power our electronic devices and electric vehicles have a number of drawbacks. The electrolyte - the medium that enables electrons and positive charges to move between the electrodes - is a flammable liquid. What's more, the lithium they're made of is a limited resource that is the focus of major geopolitical issues. Specialists in crystallography at the University of Geneva (UNIGE) have developed a non-flammable, solid electrolyte that operates at room temperature. It transports sodium - which is found everywhere on earth - instead of lithium. It's a winning combination that also means it is possible to manufacture batteries that are more powerful. The properties of these &laquoideal» batteries would be based on the crystalline structure of the electrolyte, a hydroborate consisting of boron and hydrogen. The UNIGE research team has published a real toolbox in the journal Cell Reports Physical Science containing the strategy for manufacturing solid electrolytes intended for battery developers.

The challenge of storing energy is colossal for sustainability initiatives. Indeed, the development of electric vehicles that do not emit greenhouse gases hinges on the existence of powerful, safe batteries, just as the development of renewable energies - solar and wind - depends on energy storage capacities. Lithium batteries are the current answer to these challenges. Unfortunately, lithium requires liquid electrolytes, which are highly explosive in the event of a leak. &laquoWhat's more, lithium isn't found everywhere on earth, and it creates geopolitical issues similar to those surrounding oil. Sodium is a good candidate to replace it because it has chemical and physical properties close to lithium and is found everywhere», argues Fabrizio Murgia, a post-doctoral fellow in UNIGE's Faculty of Sciences.

Too high a temperature

The two elements - sodium and lithium - are near each other in the Periodic Table. &laquoThe problem is that sodium is heavier than its cousin lithium. That means it has difficulty making its way around in the battery electrolyte», adds Matteo Brighi, a post-doctoral fellow at UNIGE and the study's first author. Accordingly, there is a need to develop electrolytes capable of transporting cations such as sodium. In 2013 and 2014, Japanese and American research groups identified hydroborates as good sodium conductors at over 120°C. At first glance, this is an excessive temperature for everyday use of batteries... but a godsend for the Geneva laboratory!

With decades of expertise in hydroborates used in applications such as hydrogen storage, the Geneva crystallographers set about working on lowering the conduction temperature. &laquoWe obtained very good results with excellent properties compatible with batteries. We succeeded in using hydroborates as an electrolyte from room temperature to 250 degrees Celsius with no safety issues. What's more, they resist higher potential differences, meaning the batteries can store more energy», continues Radovan Cerny, a professor in UNIGE's Laboratory of Crystallography and project leader.

The solution: a disorder

Crystallography - a science positioned between mineralogy, physics and chemistry - is used to analyse and understand the structures of chemical substances and predict their properties. Thanks to crystallography, it is possible to design materials. It is this crystallographic approach that was used to implement the manufacturing strategies published by the trio of Geneva-based researchers. &laquoOur article offers examples of structures that can be used to create and disrupt the hydroborates», says Murgia. The structure of the hydroborates allows spheres of boron and negatively-charged hydrogen to emerge. These spherical spaces leave enough room for positively-charged sodium ions to pass. &laquoNevertheless, as the negative and positive charges attract each other, we needed to create disorder in the structure to disrupt the hydroborates and allow the sodium to move», continues Brighi.

Today, ball games are one of the most popular leisure activities in the world, an important form of mass entertainment and big business. But who invented balls, where and when? The oldest balls that are currently known about were made in Egypt about 4,500 years ago using linen. Central Americans have been playing ball games for at least 3,700 years, as evidenced through monumental ball courts made of stone and depictions of ball players. Their oldest balls were made of rubber. Until now, it was believed that ball games in Europe and Asia followed much later: In Greece about 2,500 years ago and in China about 300 years after that.

Eurasia's oldest known balls

Researchers from the University of Zurich, together with German and Chinese researchers, have now examined in more detail three leather balls found in graves in the old Yanghai cemetery near the city of Turfan in northwest China. The balls, measuring between 7.4 and 9.2cm in diameter, have been dated at around 2,900 to 3,200 years old. "This makes these balls about five centuries older than the previously known ancient balls and depictions of ball games in Eurasia," says first author Patrick Wertmann of the Institute of Asian and Oriental Studies of the University of Zurich. "Unfortunately, however, the associated archaeological information is not sufficient to answer the question of exactly how these balls were played."

The earliest illustrations from Greece show ball players running, and depictions from China show riders using sticks. Comparable curved sticks were also found in Yanghai, but there was no apparent direct connection with the balls. Moreover, they are dated to a more recent period. "Therefore, the leather balls from Yanghai are not connected to early forms of field hockey or polo, even though two of the balls were found in the graves of horsemen," says Wertmann.

New era of Central Asian equestrian warfare

In one of the riders' graves, the preserved remains of a composite bow and a pair of trousers (1) were found, which were made in the region at that time and are among the oldest in the world. Both are signs of a new era of horse riding, equestrian warfare and fundamental societal transformations which accompanied increasing environmental changes and a rising mobility in eastern Central Asia. The current study shows that balls and ball games were part of physical exercise and military training from the very beginning. In addition, just like today, sport also played a central role in society and was a widespread leisure activity. The study's findings once again highlight that this region was a center of innovation within Eurasia several millennia ago.

In 1805, Thomas Young took the mechanical equilibrium at the solid/liquid/gas three-phase contact line into consideration (the balance of forces acting on the contact line formed by the intersection of the liquid-gas interface and the solid surface), and introduced the macroscopic concept of "contact angle" and Young's equation. Based on the assumptions of isotropic, homogeneous, and smooth surface, Young's equation gives the relationship between the intrinsic contact angle of the solid surface and the interfacial free energy at the solid/liquid/gas three-phase contact line.

However, it is difficult to obtain such a perfect surface in reality, and surfaces are usually heterogeneous. Although the macroscopic surface is smooth, the microscopic surface tends to be chaotic. The contact angle obtained in this way cannot be called the intrinsic contact angle.

To explore the intrinsic wettability of materials, the team of Prof. Xiaolin Wang from the Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong and Prof. Lei Jiang and Prof. Tian Ye from the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences jointly studied the wettability behavior of different crystal faces of sapphire (α-Al2O3) single crystals. Related results were published in the National Science Review (NSR) with the title "Crystal Face Dependent Intrinsic Wettability of Metal Oxide Surfaces".

¯1¯As we all know, the surface of alumina is hydrophilic, and the contact angle of the polycrystalline surface of alumina is about 10°. During the experiment, researchers were surprised to find that the intrinsic contact angles of all four α-Al2O3 single crystals with different crystal faces are far greater than 10°, and the contact angle of the (1-102) crystal face is very close to 90°. The previous study in our group had proven that the intrinsic hydrophilic and hydrophobic boundary of the surface material is about 65°, so the (1-102) crystal surface is hydrophobic.

Through DFT simulation of the structures of the adsorbed interfacial water molecules at different crystal faces, it was found that compared with hydrophilic (11-20), (10-10) and (0001) crystal faces, the adsorbed water molecules at (1-102) crystal face is in a standing state; that is, the hydrogen atoms of the hydrophobic crystal face are at the highest point of the first layer of adsorbed water. Therefore, water molecules from water droplets at the three-phase contact line can only form one hydrogen bond with one hydrogen atom. Since one hydrogen bond interaction is relatively weak and then the three-phase contact line is easily anchored. But on the hydrophilic crystal faces, the oxygen atoms of the adsorbed interfacial water molecule are at the highest point. In this case, there are two lone pairs of electrons of one oxygen atom to form two hydrogen bond interactions with water molecules of water droplets at the three-phase contact line. Hence, the three-line contact line is easier to spread.

So far, this work started from the atomic-level flat alumina crystal interface and proved that the orientation of adsorbed interfacial water molecules has a huge impact on macroscopic wettability of solid surfaces with the similar chemical composition (aluminum and oxygen) and almost no topographic structure (atomically flat). This work focuses on the study of intrinsic wettability of the solid interface, which may provide inspirations to improve the catalytic efficiency, prepare excellent functional materials, and improve the performance of composite devices.

Floating in fluid deep in the brain are small, little understood fronds of tissue. Two new studies reveal that these miniature organs are a hotbed of immune system activity. This activity may protect the developing brain from infections and other insults -- but may also contribute to neurodevelopmental disorders like autism.

"There is a correlation between maternal illness during pregnancy and autism, and we wanted to investigate how this is happening," says Maria Lehtinen, PhD, a neurobiologist at Boston Children's Hospital who led both studies. "It's a very challenging process to study in the lab."

The Lehtinen laboratory, part of Boston Children's Department of Pathology, is one of the few in the world to study the choroid plexus. Anchored in each of four channels in the brain called ventricles, the choroid plexus produces the cerebrospinal fluid (CSF) that bathes the brain and spinal cord. Lehtinen has shown that the choroid plexus regulates brain development, by secreting instructive cues into the CSF, and provides a protective brain barrier in early life, preventing unwanted cells or molecules in the blood circulation from freely entering the brain.

But what happens when that barrier is challenged? The lab's new work offers an unprecedented real-time view of the choroid plexus in a mouse model, providing a glimpse of how disturbances of the mother's immune system during pregnancy disrupt the developing brain. It shows that the choroid plexus can act as a conduit for inflammation, which can result from maternal infection, stress from the environment, and other factors.

A window on the choroid plexus

Because it is so deep in the brain, the choroid plexus is normally very difficult to view. The first study, published in Neuron, built special imaging tools to capture the action of cells in and around the choroid plexus in adult mice.

Led by Frederick Shipley, PhD, Neil Dani, PhD, Lehtinen, and Mark Andermann, PhD, at Beth Israel Deaconness Medical Center, the researchers carefully removed part of the skull bone and inserted a piece of clear plexiglass, creating a "skylight" into the brain. Using live two-photon imaging, which provides three-dimensional views of deep tissues, they were able to observe the choroid plexus in real time. They tracked the movements of immune cells, monitored changes in calcium (a proxy for cellular activity), and measured the secretions of cells in the choroid plexus.

The choroid plexus, inflammation, and the developing brain

The second study, published today in Developmental Cell and led by Jin Cui, PhD, applied similar techniques to observe the effects of maternal inflammation on the brains of embryonic mice. To mimic maternal inflammation, the team introduced a molecular messenger known as a cytokine to artificially trigger an inflammatory immune response into the embryos' brains, then carefully placed the embryos in an imaging chamber and conducted two-photon imaging of their brains through a tiny "skylight."

"We wanted to see how the maternal immune response is propagated into the brain, and how the choroid plexus responds to external insults during early development," says Cui.

The mock maternal inflammation was enough to draw immune cells known as macrophages to the embryo's choroid plexus. Imaging showed the cells conducting active "surveillance" in the choroid plexus even in this early embryonic stage.

"The embryonic brain is very small, so it's hard to get good resolution, but we could see macrophages moving and extending little arms as if sampling their environment," says Lehtinen. "This has never been captured before."

Markers of future autism?

The team also found an increase in inflammatory signals, particularly CCL2, in the embryonic CSF, and saw evidence that those signals were produced by immune cells at the choroid plexus.

"Many of these markers, including CCL2, are also upregulated in autism patients," notes Cui.

Further experiments showed that CCL2, on its own, was sufficient to recruit and activate immune cells at the choroid plexus. Looking at tissue specimens, the team saw evidence that macrophages had breached the choroid plexus barrier, crossing into the CSF from specific "hotspots" at the tips of the choroid plexus.

"We have added evidence that the inflammatory response perturbs the development of the brain," says Cui. "Previous studies from others have shown that maternal inflammation causes brain malformations in mouse models very early in life, and similar malformations can be seen in some autism patients."

A treatment to protect the brain?

In some of their experiments, the researchers observed patches of brain disorganization after the mice were born. But of course, much more work is needed to connect the dots from maternal inflammation to the choroid plexus to disorders like autism. Even more work would be needed to translate that knowledge into treatment.

"The goal would be to see if preventing the breaching of the choroid plexus barrier could slow or prevent the progression of disease in the brain," says Lehtinen. "That will involve collaborating with many different groups in multiple fields, as well as further advances in imaging technology that are currently underway."

University of Adelaide scientists have shown how droughts are threatening the health of wetlands globally.

Published in the journal Earth-Science Reviews, the scientists highlight the many physical and chemical changes occurring during droughts that lead to severe, and sometimes irreversible, drying of wetland soils.

"Wetlands around the world are incredibly important for maintaining our planet's biodiversity and they store vast amounts of carbon that can help fight climate change," says project leader Associate Professor Luke Mosley, from the University's Environment Institute and School of Biological Sciences.

"Globally, wetlands cover an area greater than 12.1 million square kilometres and deliver at least A$37.8 trillion (Int$27 trillion) in benefits per year, such as for flood mitigation, food production, water quality improvement and carbon storage."

Wetlands can suffer "water droughts" both from the effects of a drier climate, and also when excessive water is extracted or diverted that would normally flow into them.

The review paper describes how drought often leads to severe cracking and compaction, acidification, loss of organic matter, and enhanced greenhouse gas (for example methane) emissions. In some cases droughts can lead to very long-term (>10 years) and irreversible soil changes, with major impacts on water quality when soils are rewet after the drought ends.

"We have seen many examples of how drought in the Murray-Darling Basin has caused major issues including acidification of soil and water due to acid sulfate soils exposure in wetlands. This review highlights substantial gaps in our global understanding of the effects of drought on wet soils and how they will respond to increasing drought," says Associate Professor Mosley, who is also Deputy Director of the Acid Sulfate Soils Centre.

Effects can be different in different soil types and different regions of the world. The spatial distribution of drought studies shows there has been limited assessment in a large number of regions, including south and central America, Africa, the Middle East, Asia and Oceania. Many of these regions are predicted to be vulnerable to drought impacts due to climate change.

Lead author Dr Erinne Stirling, from Zhejiang University (China) and the University of Adelaide, says one of the most pressing findings from this review is that there are huge swaths of the world where there is no readily available published research on drought-affected wet soils.

And secondly, she says, there is effectively no applied research into water management outcomes for wetlands and wetland soils.

"At a global level, wet soils are highly vulnerable to the effects of climate change and need to be protected given the very high environmental and socio-economic values they support. It is our sincere hope that the information in this review contributes to protecting these valuable ecosystems," says Dr Stirling.

One in 12 partners experience post-traumatic stress after miscarriage, suggests a new study.
The research, led by Imperial College London, surveyed over 100 couples who had experienced early stage pregnancy loss (miscarriage or ectopic pregnancy before 12 weeks).

The study, the first ever to investigate post-traumatic stress (PTS) in partners following miscarriage, follows previous research from the same team that found around one in five women experience long-term PTS following early pregnancy loss.

The current research, published in the journal Ultrasound in Obstetrics and Gynecology, found that one month after pregnancy loss, one in 14 (7 per cent) partners met the criteria for post-traumatic stress (PTS), rising to one in 12 (8 per cent) at three months, with one in 25 partners still suffering from PTS nine months after the pregnancy loss.

The team behind the research, funded by the Imperial Health Charity and the Imperial National Institute of Health Research Biomedical Research Centre, call for improved psychological support for a woman and her partner following pregnancy loss.

Today (Friday 9th October) marks the start of UK Baby Loss Awareness Week.

Professor Tom Bourne, lead author of the research from Tommy's National Centre for Miscarriage Research at Imperial College London said: "There are around 250,000 miscarriages in the UK every year. Our previous research suggested women can be left deeply traumatised after a pregnancy loss, and this new study suggests partners also experience post-traumatic stress. Partners are often ignored when a woman experiences pregnancy loss. Yet this research suggests that although partners do not suffer PTS as often as women, there still could be many thousands of partners living with post-traumatic stress, which is a serious condition that requires treatment."
One in four pregnancies ends in miscarriage - most often before or around 12 weeks. Ectopic pregnancies always result in pregnancy loss, as an embryo grows in an area outside of the womb and is unable to develop.

The women in the study attended the Early Pregnancy Assessment Units at three London hospitals - Queen Charlottes and Chelsea, St Mary's, and Chelsea and Westminster.

All couples in the study were asked to complete validated questionnaires about their emotions and behaviour one month after pregnancy loss, then again three and nine months later. In total 102 partners completed the survey one month after the pregnancy loss, dropping to 70 at nine months after the pregnancy loss.
The responses from the women were similar to those reported in a previous study, and revealed one month following pregnancy loss, a third of women (34 per cent) suffered post-traumatic stress while one in four (26 per cent) suffered PTS three months after the pregnancy loss, and one in five (21 per cent) at nine months.

The women and partners in the study who met the criteria for post-traumatic stress reported regularly re-experiencing the feelings associated with the pregnancy loss, and suffering intrusive or unwanted thoughts about the pregnancy loss. Both women and partners also reported having nightmares or flashbacks, while others avoided anything that might remind them of their loss.
The team add that although fewer partners met criteria for PTS than women, many of the partners experienced the individual symptoms of PTS, even if they did not meet full criteria for the condition. For instance, at one month, three and nine months after the pregnancy loss, over 80 per cent of all partners reported feeling helpless, and around a third of all partners reported feeling terrified. Around 70 per cent of all partners reported re-experiencing the event, and one in five reported their symptoms had affected relationships.

Dr Jessica Farren, first author of the research from Imperial, and Obstetrician and Gynaecologist, said: "This study demonstrates there is a sizeable proportion of partners who experience severe psychological symptoms after a pregnancy loss. Moreover, those partners who did not reach the threshold for diagnosis of post traumatic stress are still very likely to be experiencing symptoms the have an impact on their wellbeing.

Post-traumatic stress can have a toxic effect on all elements of a person's life - affecting work, home and relationships. Evidence suggests the risk of relationship breakdown increases after pregnancy loss, and our research shows the loss of a pregnancy can leave have a significant and lasting psychological impact on both a woman and her partner. Hopefully an awareness of the results of this study will help couples navigate their different responses to these losses, and show each other the understanding that is needed to get through a very difficult period in their relationship."

Professor Tom Bourne added: "We have made significant progress in recent years in breaking the silence around mental health issues in pregnancy and postnatally, but early pregnancy losses are still shrouded in secrecy, with very little acknowledgement of how distressing and profound an event they are. This research suggests psychological support should be offered to both the woman and her partner, with couples given the option of attending therapy together."

The authors caution the study used a questionnaire for screening for post-traumatic stress, but formal diagnosis of post-traumatic stress disorder would require a clinical interview.

Ian Lush, Chief Executive of Imperial Health Charity, said: "As the dedicated charity for five London hospitals, we are committed to supporting pioneering research that leads to real improvements in patient care.
"This latest study shines a light on the serious psychological difficulties experienced by partners after a miscarriage and we look forward to seeing how this important research can be translated into better care for couples who face the unimaginable pain of losing a baby."
Tommy's chief executive Jane Brewin commented: "Baby loss can have a deep and lasting impact on both parents, and this study gives a voice to many who have suffered in silence, highlighting the profound consequences that can have for their mental health and wellbeing. The message is clear; partners are vulnerable to the same psychological problems as mothers, and specialist support must be made available to either or both bereaved parents.

"It's fitting that Tommy's National Centre for Miscarriage Research has raised this issue in Baby Loss Awareness Week, which this year focuses on the isolation that grieving families too often face - an issue that can be exacerbated for partners who feel they have to be strong and supportive, hiding their own heartbreak. Attitudes to baby loss must change so that anyone who wants to open up or ask for help feels able to do so."

Peter Meylakhs, from HSE University - St. Petersburg, together with colleagues from Georgia State University (USA) and Tarbiat Modares University (Tehran), have developed the HIV-PWID Policy Index (HPPI)--an international policy index for HIV prevention among people who inject drugs. This is the first major tool for assessing and comparing the extent to which HIV/AIDS prevention policies among PWID have been developed in 105 countries. The top performing countries were Spain, Switzerland, Luxembourg, Moldova, and Kyrgyzstan. The poorest performing included Nicaragua, Japan, and Syria. Russia ranked 59th. An article describing the methodology and assessment processes of the new index was published in the International Journal of Drug Policy. The work of the HSE researcher has been supported by the Russian Academic Excellence Project 5-100.

What Is This About?

There are more than 15.5 million people worldwide who inject illicit drugs each year. About one in six of these individuals is HIV-positive. The total number of newly diagnosed HIV cases among PWID continues to increase. Nonetheless, the number of infected people in this group varies from country to country, with certain countries having higher infection rates than others. This is because of the differing specifics of HIV/AIDS prevention policies.

The researchers note that national educational, preventive, therapeutic and legal responses to address the problem of injected drug use can have a strong influence on different risk factors for HIV among drug users. Interventions such as opioid substitution treatment, needle exchange and antiretroviral therapy can substantially reduce the spread of HIV among PWID.

However, at the moment, only about half these countries are implementing evidence-based policies in this area. Many others continue to subject their drug-dependent population to punitive criminal and other counterproductive measures.

Previously, the academic community had made only one attempt to construct an HIV prevention index for drug users (Lucy Platt and her colleagues at the London School of Hygiene and Tropical Medicine). However, as recognised by the authors themselves, the index is still in its 'raw' stage. It is based on a small number of indicators for 50 European countries.

With this in mind, Peter Meylakhs set about the task of developing a more precise tool. The index was originally constructed based on data from the WHO European region (Europe and the CIS). Then, in collaboration with international colleagues, he extended the geographical scope of the index to countries on all continents.

Methods

The development of the new index was done in several stages. Initially, a conceptual framework was drawn up to determine the domains and policies for constructing HPPIs. A total of six conceptual domains were included in the index, showing the status of HIV prevention among PWID in the following areas:

1. Needle and Syringe Programmes (NSPs), including those implemented in jails.

2. Methadone Replacement Therapy (Opioid Substitution Treatment). Treatment of drug dependence by prescribing methadone (a synthetic opioid). It has proven its effectiveness and is offered in all countries of America, Western Europe, and many countries of Eastern Europe. This treatment is not used in Russia--methadone is on the list of banned drugs.

3. Testing and Treatment. These include national preventive strategies for HIV testing, counselling for PWID and also access to antiretroviral treatments.

4. Information and Education. Various national measures aimed at improving the health and reducing risky behaviours among PWID.

5. Monitoring and Evaluation. National monitoring and evaluation efforts.

6. Legal and Political Climate. Legal and policy aspects to HIV prevention among PWID, including non-discrimination laws and decriminalization of HIV/PWID status.

After that, the authors analysed the quality and availability of the indicators for these areas at the individual country level. They initially collected data for 181 countries. A total of 76 countries were excluded from the analysis due to missing data on specific policy index indicators. In their collection of data, the researchers examined data sources from international organizations such as the Joint United Nations Programme on HIV/AIDS (UNAIDS), the United Nations Office on Drugs and Crime (UNODC), the WHO and the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA).

At the third stage, the authors employed FMLDEA (fuzzy multi-layer data envelopment analysis)--a multilayer data analysis to aggregate the indicators into a composite index. The figures may vary from 0 to 1. The larger the number, the higher the level of HIV prevention among injecting drug users in a given country.

What Do the Findings Show?

The results confirmed that there are substantial national and regional variations in HIV prevention policies among PWID. However, they do not necessarily depend on a country's level of economic development. Among the Top-10 countries, along with Switzerland, Norway, France and Canada, were post-Soviet countries--Kyrgyzstan, Armenia, and Moldova. Japan ranked second to last, between Cape Verde (Africa) and Nicaragua.

The high performance of some post-Soviet states could be attributable to efforts to provide international aid following the collapse of the USSR and the introduction of scientifically proven methods of prevention. 'For example, Kyrgyzstan ranks fifth in the HPPI rating because the government promotes evidence-based measures aimed at preventing and treating HIV among PWID, including official support for needle exchange programmes,' the authors note. However, they also stress that a recent study has documented significant barriers to accessing NSP services in Kyrgyzstan.

The low effectiveness of HIV prevention policies among PWID in some countries may be explained, in part, owing to the relatively low number of injecting drug users in those countries. Therefore, HIV may not be perceived as a problem by the state. For example, in the Middle East and North Africa, the proportion of PWID among the population aged 15-64 is 0.12%, while in Eastern Europe it is 1.30%.

Overall, North America (0.82) and Europe (0.81) have the most effective HIV prevention policies for PWID. The most ineffective policies are in South America (0.59), Africa (0.50) and especially Central America (0.22). Oceania (0.76) and Asia (0.66) are in the mid-range. As the authors point out, however, these averages mask significant sub-regional differences. For example, Central Asian countries perform significantly better (0.85) than the Middle East (0.33).

According to the index data, Russia ranks 59th with a score of 0.745. This is an indication that the country needs to pay more attention to HIV prevention among PWID in the country. According to official statistics from the Federal Centre for AIDS Prevention and Control, among all HIV-infected Russians with a known cause of infection identified between 1987 and 2020, almost 60% were infected through drug use. By the end of the first half of 2020, there were 1,094,050 Russians with a laboratory diagnosis of HIV infection.

Among the main reasons that Russia has not been at the forefront of HIV prevention policies among PWID, Peter Meylakhs believes, is the ban on substitution therapy and the insufficient implementation of programmes to reduce needle sharing.

Why Is This Important?

HIV prevention among injecting drug users has received considerable international attention. For example, UNAIDS has set a target of 90% access to HIV prevention services for PWID, including HIV testing, antiretroviral therapy, needle and syringe programmes, clinical services, etc. However, monitoring the implementation of such programmes at the national level is difficult owing to the lack of reliable tools for its implementation.

This is why the HIV-PWID Policy Index was developed. 'It can be used for analytics and to enhance understanding, as well as informing politicians, professionals and the public what is happening in the area of HIV prevention for PWID in different countries, in the same way that other indices, such as Transparency International, are used,' says Peter Meylakhs.

He also suggests that the index can also be useful in the development of social programmes--the introduction of evidence-based and proven interventions that can reduce the prevalence of HIV among PWID, such as substitution therapy and needle distribution.

Prevalent cases are all cases of a certain disease at a specific moment in a given population.

At the same time, he also notes that, as a monitoring tool, HPPI has a number of limitations. It is only as reliable as the basic data used to construct it. Moreover, countries from certain regions of the world, including most of sub-Saharan Africa and South America, have limited data on HIV/AIDS, which can also affect the accuracy of the statistical measurements.

Stem cells are cell factories that constantly divide themselves to create new cells. Implanting stem cells in damaged organs can regenerate new tissues. Cell sheet engineering, which allows stem cells to be transplanted into damaged areas in the form of sheets made up of only cells, completely eliminates immune rejection caused by external substances and encourages tissue regeneration. A research team led by POSTECH recently succeeded in drastically reducing the harvest period of such stem cell sheets.

A joint research team comprised of Professor Dong Sung Kim and researcher Andrew Choi of POSTECH's Department of Mechanical Engineering and Dr. InHyeok Rhyou and Dr. Ji-Ho Lee of the Department of Orthopedic Surgery at Pohang Semyung Christianity Hospital has significantly reduced the total harvest period of a stem cell sheet to two days. The nanotopography of poly(N-isopropylacrylamide) (PNIPAAm), which abruptly changes its roughness depending on temperature, allows harvesting of cell sheets that consist of mesenchymal stem cells derived from human bone marrow. Considering that it takes one week on average to make stem cells into sheets using the existing techniques developed so far, this is the shortest harvest time on record. These research findings were published as a cover paper in the latest issue of Biomaterials Science, an international journal in the biomaterials field.

Professor Kim's research team focused on PNIPAAm, a polymer that either combines with water or averts it depending on the temperature. In previous studies, PNIPAAm has been introduced as a coating material for cell culture platform to harvest cell sheets, but the range of utilization had been hampered due to the limited types of cells that can be made into sheets. For the first time in 2019, the research team developed a technology of easily regulating the roughness of 3D bulk PNIPAAm and has stably produced various types of cells into sheets.

The study conducted this time focused on making stem cells - that are effective in tissue regeneration - into sheets in a short time in order to increase their direct utility. The team achieved this by applying an isotropic pattern of nanopores measuring 400 nanometers (nm, 1 billionth of a meter) on the surface of a 3D bulk PNIPAAm. As a result, not only did the formation and maturity of human bone marrow-derived mesenchymal stem cells on the nanotopography of bulk PNIPAAm accelerate, but the surface roughness of bulk PNIPAAm at room temperature below the lower critical solution temperature (LCST) was also rapidly increased, effectively inducing the detachment of cell sheets. This in turn enabled the rapid harvesting of human bone marrow-derived mesenchymal stem cell sheets.

"At least five days are needed to harvest stem cell sheets reported through previous researches," commented Andrew Choi, the " author of the paper. "We can now harvest them in just two days with the PNIPAAm nanotopography developed this time."

"We have significantly shortened the harvest time by introducing nanotopography on the surface of the 3D bulk PNIPAAm to produce mature stem cell sheets for the first time in the world," remarked Professor Dong Sung Kim who led the study. He added, "We have opened up the possibility of applying the sheets directly to patients in the future."

Scientists have found that as the world undergoes profound environmental change, identifying and protecting 'novel' communities of species can help prevent extinctions within vulnerable ecosystems.

Professor John Pandolfi and Dr Timothy Staples from the ARC Centre of Excellence for Coral Reef Studies at The University of Queensland (CoralCoE at UQ) are the lead authors of a new study in Science that looked at how combinations of plankton species changed across the world's marine ecosystems in the past 66 million years. From this, their team developed a world first method to detect 'novel' communities of species across all ecosystems.

"A novel ecological community is one with combinations of species that are different to any past observations from that site," Prof Pandolfi said. "These different species combinations can be due to new species arriving in the community, existing species leaving, or species becoming rarer or more common."

"We found that when novel communities formed, existing species were twice as likely to disappear from the community permanently, representing a 'local' extinction."

"Species in the novel community were also more likely to be new arrivals that had never been observed in the community before."

An example of a modern novel community is the coral reefs of the Caribbean, where the two once dominant species of branching coral are now rare. Those reefs are now home to new, or novel, communities of corals. The loss of the branching corals is due to the impacts of overfishing, changes in water quality, and climate change--resulting in new configurations of coral species within the Caribbean reef communities. And the shift means the benefits of the reef are now different: different species means different inhabitants and functions.

"The challenge is to manage at risk or vulnerable areas like this where novel communities exist, or where they're in the process of forming," Prof Pandolfi said.

"To do this we need to understand the changes in species composition we see in novel communities, as well as what is driving these changes. To achieve these goals, we need to be able to reliably identify when a novel community has emerged."

The study outlines the first standardised, quantitative methodology for determining the existence of novel ecological communities. The researchers used a database of marine plankton over millions of years, but the methodology was designed to be applied more generally.

"We came up with a measure of novelty that can be used with community data from any time scale, organism or ecosystem, so comparative approaches to the study of novelty are now possible," Dr Staples said. "In this study, we applied our methodology to the past 66 million years, but it would work just as well on much shorter time frames."

The researchers examined the marine plankton record using a global set of microfossil data from deep sea drilling cores-- the NSB marine microfossil database, created and run by the Museum für Naturkunde in Berlin. By incorporating updated taxonomy and age models they built community data for species across geological time.

Prof Pandolfi said while novelty was rare, extinction was an important component. And after novel communities emerged, subsequent communities were more likely to develop into yet other novel states.

"Novelty begets novelty," Prof Pandolfi said. "And the likelihood of extinction was higher when novel communities emerged."

He said the pressures that cause communities to become novel in the first place need to be relieved. "Otherwise we may end up with cascading novelty, where the emergence of novel communities drives further novelty, including the loss of existing, native, species."

Prof Pandolfi says this means when a novel community is identified it needs attention and effective preventive management. He also says future studies need to identify novel communities within vulnerable ecosystems, such as the Great Barrier Reef. "At the end of the day that's where we want to go to test this," he said.

Though the time frame of evolutionary change is generally much slower than the timeframe of change currently occurring on the Great Barrier Reef, there are signs that novelty communities may be emerging there. The assemblage of corals on the reef are not what they were five or ten years ago.

"Our novelty framework is equally applicable to investigate the Great Barrier Reef at this ecological scale," Dr Staples said.

"Modern novel ecological communities may need to be managed effectively to prevent the propagation of subsequent novel communities, because of the associated risk of increased extinction," Prof Pandolfi said.

"We can't just throw in the towel and let those ecosystems degrade, we need to arrest this progression."