Brain

Anxiety and depression are significantly heightened during times of great stress such as the COVID-19 pandemic. Unfortunately, psychosocial stress is a major contributing factor to anxiety and depression. There is evidence that stress is associated with increased inflammation - increases in inflammatory cytokines, circulating monocytes, and microglial activation, which are detected in patients with anxiety and mood disorders.

Chronic stress has long been associated with the pathogenesis of psychological disorders such as depression and anxiety. Recent studies have found chronic stress can cause neuroinflammation: activation of the resident immune cells in the brain, microglia, to produce inflammatory cytokines. Numerous studies have implicated the inflammatory cytokine, interleukin-1 (IL-1), a master regulator of immune cell recruitment and activity in the brain, as the key mediator of psychopathology. However, how IL-1 disrupts neural circuits to cause behavioral and emotional problems seen in psychological disorders has not been determined.

A groundbreaking study by neuroscientists at Florida Atlantic University and The Ohio State University, published in the journal Molecular Psychiatry, is the first to identify a role of the neuronal receptor for IL-1 (nIL-1R) in psychological disorders. Researchers demonstrate that nIL-1R straddles the intersection between social stress, inflammation, and anxiety in rodent models of stress.

The study shows for the first time that neuronal IL-1Rs in the hippocampus, a brain structure connected to learning and memory, is necessary and sufficient to mediate some of the behavioral deficits caused by chronic stress, pointing to a critical neuroimmune mechanism for the etiology of these types of disorders. Findings from the study augment the understanding of IL-1R signaling in physiological and behavioral responses to stress and also suggest that it may be possible to develop better medications to treat the consequences of chronic stress by limiting inflammatory signaling not just generally, which may not be beneficial in the long run, but to specific brain circuits.

"We created and validated a unique genetic mouse model to restrict IL-1R1 expression to different cell types to visualize and control IL-1Rs," said Ning Quan, Ph.D., lead author, a professor of biomedical science in FAU's Schmidt College of Medicine, and a member of the FAU Brain Institute (I-BRAIN). "We demonstrated that chronic social stress caused the mice to show social withdrawal and working memory deficits. These changes could be prevented if the neuronal IL-1R1 was deleted and restored if IL-1R1 was only allowed to be expressed on hippocampal neurons."

For the study, researchers wanted to determine the degree to which IL-1 acts directly on hippocampal neurons to influence cognitive and mood changes with stress. To define the IL-1R-mediated neuronal response, they used novel and comprehensive IL-1R transgenic/reporter lines in which one can selectively delete IL-1R or restore IL-1R on specific cell types, including glutamatergic neurons. They also used modified viruses to manipulate hippocampal neurons and investigate the role of IL-1R in eliciting behavioral responses to stress. Their data show that social defeat-induced IL-1R signaling in hippocampal neurons perpetuated inflammation and promoted deficits in social interaction and working memory.

The research team previously detailed how psychosocial stress results in peripheral immune activation, increased levels of circulating monocytes, and robust neuroimmunological responses in the brain. These responses include increases in IL-1 and other inflammatory cytokines, activation of brain glial cells and movements of peripheral immune cells to the brain, along with enhanced activity of specific neuronal pathways. The work makes it clear that inflammatory-related effects of stress are not just global effects, but are associated with increased IL-1 signaling within specific brain circuits.

According to the Anxiety and Depression Association of America, nearly 40 million people in the United States (18 percent) experience an anxiety disorder in any given year. Globally, the World Health Organization (WHO) notes that 1 in 13 people suffers from anxiety. Anxiety disorders are the most common mental disorders worldwide with specific phobia, major depressive disorder and social phobia being the most common anxiety disorders.

"We are experiencing unprecedented levels of stress that will likely have long-lasting effects on millions of people of all ages around the world. When psychosocial stress becomes chronic, the effects are not just emotionally debilitating, they also are physically debilitating and can lead to high blood pressure, heart disease and even addictive behavior," said Randy Blakely, Ph.D., executive director of FAU's I-BRAIN. "Findings from this cutting-edge study will assist scientists and clinicians to develop more tailored treatments and therapies for people who struggle with anxiety, depression and other psychological disorders."

Researchers from the Faculty of Physics at the University of Warsaw, ETH in Zurich and the University of Cambridge have synthesized and analysed active microparticles self-propelling in a fluid and reversing their propulsion direction depending on the wavelength of illuminating light. A research article summarising their work has recently been published in Nature Communications.

Active matter encompasses systems elements of which can self-propel, drawing the energy from their environment and converting it into kinetic energy. This direction of research is currently a lively discipline in physics. It spans across many time and length scales, concerning e.g. the behaviour of birds in flocks (such as murmurations of starlings in the evening sky), schools of fish (as a form of protection against predators), and also bacteria in biofilms and other aquatic microswimmers. It focuses both on the behaviour of individual elements and understanding their mechanisms of energy conversion, interaction and coupling with the environment so important for the survival, and on the collective effects and emergence of new phenomena in large population. Both can be successfully described on different levels of precision, starting from simplistic minimal coarse-grained models, and up to refined numerical simulations.

Bacteria, algae, spermatozoa, ciliates and other unicellular organisms are an important group of active swimmers. Exploring the physical basis of their dynamics is often complicated by their immense diversity, biological complexity, and high sensitivity to external conditions. Aquatic microworld is, however, governed by the universal laws of fluid dynamics which put limitations on all organisms. Due to their small sizes - micrometers, typically - and swimming speeds not exceeding tens of body lengths per second, the flow around them is dominated by viscous effects. This means that the swimming strategies of sharks or olympic swimmers fail completely in microscale competition. Macroscale swimming is based on inertia and pushing the water backwards rapidly. In microscale, inertial effects are negligible and water behaves like a very viscous fluid, such as honey or golden syrup. Imagine swimming in a pool filled with honey - a crawl stroke would be very exhausting and highly ineffective. Hence, swimming microorganisms have devised other strategies for propulsion, based on exploiting viscosity. Bacteria often have helical flagella, which they use to 'screw into' the fluid like a corkscrew. It turns out that in the viscous microworld this strategy allows for effective locomotion. Larger organisms, such as ciliates (and Paramecium among them, an often used example in school biology), have their bodies covered with thousands of cilia, resembling tiny hair. They move them in a coordinated way, similarly to a Mexican wave at a stadium. This allows the fluid to be dragged along the cell surface, and in result the cell propels in the direction opposite to the ciliary wave propagation.

Understanding these mechanisms has inspired the development of a novel field of synthetic microswimmers. The vision of designing microrobots in laboratories has excited researchers for many years due to the potential wide applications in diagnostics, medicine, and technology, such as targeted drug delivery inside the patient's body. From this perspective, it is vitally important not only to design such swimmers, but also to control their motion.

The mechanism described above and used by ciliated swimmers (also in multicellular organisms, e.g. cilia in human lungs and reproductive tract are essential for the transport of mucus), has inspired a number of swimmers using the phenomenon of diffusiophoresis. In order to explain it, let us take up the example of a Janus particle, inspired by the Roman god with two faces. A typical realisation is a spherical microparticle with one hemisphere covered with gold, and the other covered with platinum. When placed in a solution of hydrogen peroxide (H2O2), the platinum side catalyses the decomposition of the peroxide to water and oxygen. In result, the concentration of products of this reaction on the platinum hemisphere increases and the concentration imbalance creates flow along the surface. Similarly to the swimming ciliates, motion of the fluid along the surface causes motion of the cell in the opposite direction. We thus have a system which locally converts chemical energy of its surroundings into its own kinetic energy. The mechanism described above is universal, the key ingredient being the nonuniform concentration of the reagents on the surface. Moreover, the chemical gradients can be replaced by an imbalance of temperature or electrostatic potential. All of these mechanisms have been experimentally confirmed in microscopic systems. It is worth noting that the typical sizes and swimming speeds of these synthetic swimmers are comparable to their biological source of inspirations. Thus by exploring artificial active matter we gain an additional insight into the swimming microworld.

Many propulsion mechanisms have been proposed and are available for synthetic active matter. The challenge remains to control the motion of a swimmer, or program it such that it could reach a predefined place and e.g. deliver a drug to a chosen part of the body. Alternatively, it could be steered by an external stimulus, such as electromagnetic radiation, electric or magnetic fields, sound waves, or inhomogeneous temperature.

A step in this direction is presented in the new paper by researchers from University of Warsaw, ETH in Zurich, and University of Cambridge, published recently in Nature Communications. It demonstrates novel, modified Janus particles, moving in a fluid under the influence of external lighting, with the direction of motion depending on the wavelength of the incident light. The particles with a diameter of 3.5 microns were made from anatase - a polymorph of titanium dioxide - with one hemisphere coated with gold. When illuminated with green visible light, the particles move towards the gold cap, while when exposed to UV light, they reverse their direction of motion. The particles were synthesised by Dr. Hanumantha Rao Vutukuri and Prof. Jan Vermant at ETH Zurich, where all the experimental works were performed.

'By changing the wavelength of light we activate different catalytic mechanisms on the particle surfaces, by which we can quickly steer the motion in a controlled way' says Dr. Maciej Lisicki from the Faculty of Physics, University of Warsaw. 'Moreover, we see very interesting collective dynamics: the particles can attract or repel each other, depending on their relative orientation and the colour of illuminating light. Tuning this, we observe rapid processes of fusion and fission, which we can steer'.

The description of motion in such a system requires considering both the chemical interactions of particles though their inhomogeneous concentration fields of the reagents created on their surfaces, as well as the hydrodynamic flow caused by their presence. The theoretical model allowing to describe the dynamics of these novel active particles was constructed by Dr. Maciej Lisicki (Warsaw) and Prof. Eric Lauga (Cambridge).

'At micrometric sizes, we think about the fluid around the particles as being very viscous' says Maciej Lisicki. 'Their hydrodynamic interactions are thus far-ranged. The motion of each particle is felt by all others.'

The researchers, who have been working on the applications of diffusiophoresis to the synthesis of artificial swimmers and microscale pumping for a long time now, believe that this novel, reversible and controlled mechanism of self-propulsion for Janus particles is a step on the way towards more complex microrobots which will eventually be able to transport cargo on cellular scale. It could also be used to control collective motion in microscale by local light-induced stirring in suspensions of active particles and mixtures of active and passive colloids suspended in a fluid.

Physics and Astronomy first appeared at the University of Warsaw in 1816, under the then Faculty of Philosophy. In 1825 the Astronomical Observatory was established. Currently, the Faculty of Physics' Institutes include Experimental Physics, Theoretical Physics, Geophysics, Department of Mathematical Methods and an Astronomical Observatory. Research covers almost all areas of modern physics, on scales from the quantum to the cosmological. The Faculty's research and teaching staff includes ca. 200 university teachers, of which 87 are employees with the title of professor. The Faculty of Physics, University of Warsaw, is attended by ca. 1000 students and more than 170 doctoral students.

The ever-worsening global environmental crisis, coupled with the depletion of fossil fuels, has motivated scientists to look for clean energy sources. Hydrogen (H2) can serve as an eco-friendly fuel, and hydrogen generation has become a hot research topic. While no one has yet found an energy-efficient and affordable way to produce hydrogen on a large scale, progress in this field is steady and various techniques have been proposed.

One such technique involves using light and catalysts (materials that speed up reactions) to split water (H2O) into hydrogen and oxygen. The catalysts have crystalline structures and the ability to separate charges at the interfaces between some of their sides. When light hits the crystal at certain angles, the energy from the light is absorbed into the crystal, causing certain electrons to become free from their original orbits around atoms in the material. As an electron leaves its original place in the crystal, a positively charged vacancy, known as a hole, is created in the structure. Generally, these "excited" states do not last long, and free electrons and holes eventually recombine.

This is the case with bismuth vanadate (BiVO4) crystal catalysts as well. BiVO4 has been recently explored for water-splitting reactions, given its promise as a material in which charge-separation can occur upon excitation with visible light. The quick recombination of pairs of charged entities ("carriers") is a disadvantage because carriers must separately partake in reactions that break up water.

In a recent study published in Chemical Engineering Journal, scientists from the Photocatalysis International Research Center at Tokyo University of Science, Japan, together with scientists from Northeast Normal University in China, developed a novel method to improve the charge-separation characteristics of decahedral (ten-sided) BiVO4 crystal catalysts. Prof Terashima, lead scientist in the study, explains, "Recent studies have shown that carriers can be generated and separated at the interfaces between the different faces of certain crystals. In the case of BiVO4, however, the forces that separate carriers are too weak for electron-hole pairs that are generated slightly away from the interfaces. Therefore, carrier separation in BiVO4 decahedrons called for further improvements, which motivated us to carry out this study."

In the technique they propose, BiVO4 nanocrystals are exposed to what is called "solution plasma discharge", a highly charged jet of energetic matter that is produced by applying high voltages between two terminals submerged in water. The plasma discharge removes some vanadium (V) atoms from the surface of specific faces of the crystals, leaving vanadium vacancies. These vacancies act as "electron traps" that facilitate the increased separation of carriers. Because these vacancies are in greater number on the eight side faces of the decahedron, electrons are trapped on these faces while holes accumulate on the top and bottom faces. This increased charge separation results in better catalytic performance of the BiVO4 nanocrystals, thereby improving its water splitting performance.

This study represents a novel use of solution plasma discharge to enhance the properties of crystals. Prof Akira Fujishima, co-author of the paper, says, "Our work has inspired us to reconsider other crystals that are apparently ineffective for water splitting. It provides a promising strategy using solution plasma to 'activate' them." The use of solution-plasma discharge has many advantages over using conventional gaseous plasma that make it far more attractive from both technical and economic standpoints. Prof Xintong Zhang from Northeast Normal University, China, remarks, "Unlike gaseous plasma, which has to be generated in closed chambers, solution plasma can be generated in an open reactor at room temperature and in a normal air atmosphere. In addition, by working with crystal powders in a solution, it becomes more convenient to change the parameters of the process, and it is also easier to scale up."

This study hopefully takes us one step closer to an efficient way of producing hydrogen so that we can finally do without fossil fuels and other energy sources that are harmful to our planet. Further commenting on the promise of this study, Prof Terashima says, "If efficient hydrogen energy can be produced using sunlight and water, two of the most abundant resources on earth, a dream clean society could be realized."

School-based mindfulness programs can improve decision-making skills and teach children with autism to focus attention and react less impulsively through breathing exercises that will allow them to reduce anxiety, according to Rutgers researchers.

The study, published in the journal Research in Developmental Disabilities, is the first to examine the effectiveness of a school-based mindfulness program that emphasizes self-awareness and controlled breathing in children on the autism spectrum.

Mindfulness practice trains people to focus their attention on awareness of the present moment. In neurotypical children, it has been shown to improve decision-making skills and to be effective in reducing anxiety, a common condition in the one in 68 children nationwide diagnosed with autism.

The researchers administered an eight-week mindfulness program to 27 high-functioning students with autism ages 10 to 17 at Newmark, a private school for children with special needs in New Jersey. Students were introduced to the basic tenets of mindfulness, then taught specific practices such as mindful breathing or focusing attention on the body, thoughts and emotions.

The students were tested on their impulse control, attention and decision-making before and after the program. "We found that the children improved their executive functions like controlling emotions, maintaining self-control, focusing attention and being flexible in changing their perspectives," said lead investigator Helen Genova, a research assistant professor in the Department of Physical Medicine and Rehabilitation at Rutgers New Jersey Medical School and director of the Social Cognition and Neuroscience Laboratory at Kessler Foundation. "As in previous studies on school-based mindfulness programs and typically functioning children, we found that the practice taught the students to take a moment to stop and breathe. This reduced impulsiveness and allowed them to make better decisions."

Regina Peter, co-executive director of Newmark, said the school promotes mindfulness every morning and before tests and competitions. "Practicing mindfulness teaches our students the important skill of treating the moment as something that needs to be attended to and to let everything else go," she said. "The wonderful thing about mindfulness is that it is a tool they can take out when they need it. It is not a medication with side effects, and it's free."

Nanophotonics uses light polarization as an information carrier in optical communications, sensing, and imaging. Likewise, the state of polarization of light plays a key role in the photonic transfer of quantum information. In this framework, optical nanodevices enabling dynamic manipulation of light polarization at the nanoscale are key components for future nanophotonic applications.

Magnetic materials exhibit the so-called magneto-optical (MO) activity, arising from spin-orbit coupling of electrons, which results in a weak magnetic-field-induced intensity and polarization modulation (in the order of mrads) of reflected and transmitted light.

Magneto-plasmonics explores nanostructures and metamaterials that combine the strong local enhancements of electromagnetic fields produced by localized plasmon excitations, i.e., collective oscillations of the quasi-free electrons, with the inherent MO activity of the magnetic constituent to enhance the otherwise weak magnetic-field-induced polarization modulation.

Up to now, most studies on magneto-plasmonics focused on the excitation of bright (i.e. radiant) localized dipolar plasmonic resonances, known as LPRs, to amplify the MO response. Indeed, dimeric and multilayered hybrid noble/ferromagnetic metals structures as well as purely ferromagnetic nanoantennae have demonstrated the possibility to control and amplify the MO properties via plasmonic excitations. For instance, considering the archetypical case of a circular disk-like magneto-plasmonic nanoantenna, incident radiation of proper wavelength excites an LPR (Po in the figure). When the nanoantenna is "activated" by a magnetic-field (H), a second LPR is induced by the inherent MO activity (PMO in the figure.). This MO-induced LPR (or MOLPR) is driven by the LPR in a direction orthogonal to both H and the LPR. The ratio between the MOLPR and the LPR corresponds to the ratio between the response of orthogonal radiating electric dipoles that determine the magnetic-field induced polarization change of re-emitted light4. However, the generation of a large MO-induced electric dipole associated to the MOLPR results from a parallel enhancement of the electric dipole associated to the LPR. The simultaneous excitation of the LPR, radiating light with the incident polarization, and MOLPR, radiating light with a polarization orthogonal to the incident radiation, limits the maximum achievable enhancement of magnetic-field activated change in polarization of reflected and transmitted light. Due to this limitation of the MO enhancement exploiting bright dipolar resonances, amplifications up to about only 1-order of magnitude of the MO response have been observed experimentally, which are not enough for practical applications of magneto-plasmonics to active nanophotonics and flat-optics.

In a new paper published in Light Science & Application, an international team lead by the Nanoscience Cooperative Research Center, CIC Nanogune, Spain, had proposed and demonstrated a strategy to overcome the aforementioned limitation based on the excitation of hybrid high order multi-polar dark modes as a viable and powerful mean to amplify the magneto-optical activity of magneto-plasmonic nanoantennas and achieve an unprecedented active control of the light polarization under a magnetic field. The authors had designed a symmetry broken non-concentric magneto-plasmonic-disk/plasmonic-ring nanostructures in order to enable the free-space light excitation of multipolar dark modes in the plasmonic-ring as well as their hybridization with the dipolar plasmonic resonance of the magneto-plasmonic disk, leading to a hybrid multipolar mode.

The large amplification of the MO response of our nanocavity is the result of a strongly enhanced radiant MOLPR, which is driven by the low-radiant hybrid multipolar resonance instead of a bright LPR. In this way the amplification of the radiated light from the strongly amplified MO response is achieved avoiding a simultaneous large enhancement of radiated light with the incident polarization.

Washington, DC, June 2, 2020 - A study in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP), published by Elsevier, reports that many of the former child soldiers of Sierra Leone have been accepted by their families and communities as they try to overcome their childhood trauma, according to a team led by Boston College School of Social Work Salem Professor in Global Practice, Theresa S. Betancourt.

The report that also included contributions by co-authors from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Harvard's T. H. Chan School of Public Health, and Child Trends of Bethesda, MD, USA, and reported that it may take a greater focus on family- and community-based approaches to help former child soldiers achieve social reintegration.

Former child soldiers experience mental health problems as a result of their experiences, but acceptance from families and communities shapes the lives of these men and women and shows promise to help them to continue to improve emotionally and socially, according to the "Longitudinal Study of War-Affected Youth", which follows former child soldier into adulthood.

"Not only were child soldiers exposed to horrors during the war, but when they returned to their families and communities, stigma was one of the biggest barriers to overcome. We set out to study the effects of the post-war environment on these already-vulnerable youth," said Dr. Betancourt.

During the 11-year civil war, several warring factions abducted children and forced their involvement in armed groups. An estimated 15,000 to 22,000 boys and girls of all ages were subjected to repeated sexual and physical violence, forced use of alcohol and drugs, hard physical labor and acts of violence until the war ended in 2002.

Since 2002, researchers interviewed more than 500 former child soldiers periodically until 2016-2017, when the most recent assessment took place. The average age of the respondents was 28 in 2016-2017. Over 25 percent of respondents reported they had killed or injured others while conscripted; nearly half of the women surveyed and five percent of the men reported the experience of rape. Thirty-two percent reported the death of a parent.

"Sierra Leone's child soldiers experienced violence and loss on a scale that's hard to comprehend," said co-author Stephen Gilman of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Rockville, MD, USA. Nearly half the respondents detailed symptoms of anxiety and depression, with 28 percent suffering from symptoms of post-traumatic stress disorder at a level associated with clinical disorder.

A deeper examination of the respondents' lives - particularly the stigma they are subject to and the level of acceptance by family and community - led to the classification of three groups:

A Socially protected group, nearly two-thirds of the respondents, reported they were not heavily stigmatized for their war involvement and had high levels of acceptance from their families and communities

An Improving social integration group included respondents who in 2002 reported high levels of stigmatization and low rates of acceptance but have since reported a decrease in community stigma and increase in acceptance by families and communities. This group was largely female and more likely to have been raped.

A Socially vulnerable group, whereby roughly 10 percent of the respondents were highly stigmatized and had low family and community acceptance. This group was largely male, spent more time in fighting forces and were more likely to have killed (or injured) others during the war.

Those in the Improving social integration group made gains, though they reported problems such as getting in trouble with local police. In contrast, members of the Socially vulnerable group showed many indicators of concern compared to the Socially protected group, including: 1) they were about twice as likely to experience high levels of anxiety and depression; 2) they were three times more likely to have attempted suicide; and 3) they were over four times more likely to have been in trouble with the police.

The authors concluded that efforts to address family and community relationships with particular attention to improving social supports and reducing stigma remain critical ingredients of interventions to help former child soldiers adapt and thrive in their post-conflict lives. "There is healing power in the relationships young people build in their families and communities," said Dr. Betancourt. "What these latest findings indicate is that just as much attention should be paid to family and community relationships as to the traumatic events of their past. Efforts to alleviate mental health problems, enhance opportunities and improve life outcomes for former child soldier need to focus much more on family and community relationships."

Co-author and statistician, Robert T. Brennan added that, "Conducting a study like this over so many years in Sierra Leone is a real challenge. Addresses are approximate, birthdays, even ages, are often unknown, and natural disasters displace whole communities. For instance, we had to postpone data collection due to the Ebola outbreak of 2014-2015."

The authors state further research is needed because the study design did not allow them to establish a causal link between stigma and poor mental health outcomes. However, the study suggests change is possible.

"Because this study follows a single cohort of former child soldiers - some as young as 10 years old - into young adulthood, it is certain to be a landmark in the study of the exploitation of children by armed groups," said Boston College School of Social Work Dean Gautam N. Yadama.

Scientists at UCL have discovered sets of regulatory genes, which are responsible for maintaining healthy hearing. The finding, made in fruit flies, could potentially lead to treatments for age-related hearing loss (ARHL) in humans.

Globally one third of people (1.23 billion people) aged over 65 experience hearing impairment, and while there are thought to be more than 150 candidate genes which may affect hearing loss, there is no unified view on how to use these to develop novel preventive or curative hearing loss therapies.

In the study, published in Scientific Reports, researchers at the UCL Ear Institute assessed the hearing ability of the common fruit fly (Drosophila melanogaster) across its life span (around 70 days*), to see if their hearing declines with age.

The fruit fly is a powerful model in biology and its ear shares many molecular similarities with the ears of humans, which make it an ideal tool for the study of human hearing loss. However, so far, no study had assessed the fruit flies' hearing across their life course.

Using advanced biomechanical, neurophysiological and behavioural techniques**, the researchers found that the antennal ears of fruit flies also display ARHL with nearly all measures of sensitive hearing starting to decline after 50 days of age.

With this knowledge, the researchers turned their interest to the time before flies developed ARHL: they wanted to know if there were any 'age-variable' genes in the flies' Johnston's Organ (their 'inner ear'), which have kept the ears healthy for 50 days of their lives.

Using a combination of molecular biology, bioinformatics and mutant analysis, the researchers identified a new set of transcriptional regulator genes: these are so called 'homeostasis genes', meaning they are the genetic actuators, so they control the activity which keeps the ear sensitive.

For researchers, one of the principle advantages of the fruit fly model is that it allows for easily testing the roles of individual genes by either increasing their function (overexpression) or silencing them (RNAi interference). Exploiting these tools, researchers also found that manipulating some of the homeostasis genes could prevent the flies from getting ARHL.

Lead author Professor Joerg Albert (UCL Ear Institute) said: "While many studies have been conducted into the hearing function of fruit flies, ours is the first to look at the mechanistic and molecular detail of their auditory life course.

"Our twin discoveries that fruit flies experience age-related hearing loss and that their prior auditory health is controlled by a particular set of genes, is a significant breakthrough. The fact that these genes are conserved in humans will also help to focus future clinical research in humans and thereby accelerate the discovery of novel pharmacological or gene-therapeutic strategies.

"Building on our findings from Drosophila, we have already started a follow-up drug discovery project designed to fast-track novel treatments for human ARHL."

Dr Ralph Holme, Executive Director of Research at Action on Hearing Loss, said: 'We urgently need to find effective treatments able to prevent or slow the loss of hearing as we age.

"Hearing loss affects 70% of people aged over 70 years old, cutting people off from friends and family.

"Action on Hearing Loss is proud to have been able to support this exciting research that has identified genes involved in maintaining hearing.

"It not only advances our understanding of why hearing declines with age, but importantly also opens the door to the future development of treatments to prevent it."

A new study by University of Alberta geologists is proposing a new model for explaining the eruption of diamond-bearing kimberlites in Northern Alberta.

The research demonstrates that 90 to 70 million years ago, the movement of an ancient slab of oceanic rocks buried hundreds of kilometres beneath Earth's surface caused the eruption of diamond-bearing kimberlite in Northern Alberta.

"We are able to provide a new theory about why we have diamond-bearing kimberlites in Northern Alberta, which has been a source of debate for decades," explained Yunfeng Chen, who conducted this research as part of his graduate studies with Jeffrey Gu, professor in the Department of Physics. "Our work is based on geological, paleomagnetic, and seismic data from our collaborators both at the University of Alberta and around the world."

The model enables scientists to match the seismic structures with the time and location of kimberlite eruptions in the area, explaining how these diamonds came to Earth's surface in the Late Cretaceous period--and providing key insight for those on the hunt for other deposits in the region.

"The kimberlites in Northern Alberta were discovered in relatively young parts of Earth's crust--an unconventional setting for diamond-bearing kimberlites," added Chen. "This distant location relative to other major kimberlite groups in North America plus the large variability of compositions further highlight the complex nature of the origins of kimberlite."

The multidisciplinary study combines the work of geophysical imaging, geochronological dating, and plate motion calculation.

"What we have observed in Northern Alberta is similar to Hawaii," said Gu. "In both scenarios, a relatively stationary mantle heat source essentially burned through the migrating plates above it, leaving 'scars' on the Earth's surface. Diamonds were carried to the surface through this 'upwelling' process."

A key difference is that the generation of the mantle upwelling in Northern Alberta took place no deeper than 700 kilometres below surface, whereas the ongoing Hawaii 'plume' appears to have occurred much deeper, at approximately 2,900 kilometres under Earth's surface.

HOUSTON - (June 2, 2020) - Boron nitride nanotubes are anything but boring, according to Rice University scientists who have found a way to watch how they move in liquids.

The researchers' method to study the real-time dynamics of boron nitride nanotubes (BNNTs) allowed them to confirm, for the first time, that Brownian motion of BNNTs in solution matches predictions and that, like carbon nanotubes of comparable sizes, they remain rigid.

Those properties and others -- BNNTs are nearly transparent to visible light, resist oxidation, are stable semiconductors and are excellent conductors of heat -- could make them useful as building blocks for composite materials or in biomedical studies, among other applications. The study will help scientists better understand particle behavior in the likes of liquid crystals, gels and polymer networks.

Rice scientists Matteo Pasquali and Angel Martí and graduate student and lead author Ashleigh Smith McWilliams isolated single BNNTs by combining them with a fluorescent rhodamine surfactant.

This allowed the researchers to show their Brownian motion -- the random way particles move in a fluid, like dust in air -- is the same as for carbon nanotubes, and thus they will behave in a similar way in fluid flows. That means BNNTs can be used in liquid-phase processing for the large-scale production of films, fibers and composites.

"BNNTs are typically invisible in fluorescence microscopy," Martí said. "However, when they are covered by fluorescent surfactants, they can be easily seen as small moving rods. BNNTs are a million times thinner than a hair. Understanding how these nanostructures move and diffuse in solution at a fundamental level is of great importance for manufacturing materials with specific and desired properties."

The new data comes from experiments carried out at Rice and reported in the Journal of Physical Chemistry B.

Understanding how shear helps nanotubes align has already paid off in the Pasquali lab's development of conductive carbon nanotube fibers, films and coatings, already making waves in materials and medical research.

"BNNTs are the neglected cousins of carbon nanotubes," Pasquali said. "They were discovered just a few years later, but took much longer to take off, because carbon nanotubes had taken most of the spotlight.

"Now that BNNT synthesis has advanced and we understand their fundamental fluid behavior, the community could move much faster towards applications," he said. "For example, we could make fibers and coatings that are thermally conductive but electrically insulating, which is very unusual as electrical insulators have poor thermal conductivity."

Unlike carbon nanotubes that emit lower-energy near-infrared light and are easier to spot under the microscope, the Rice team had to modify the multiwalled BNNTs to make them both dispersible and viewable. Rhodamine molecules combined with long aliphatic chains served this purpose, attaching to the nanotubes to keep them separate and allowing them to be located between glass slides separated just enough to let them move freely. The rhodamine tag let the researchers track single nanotubes for up to five minutes.

"We needed to be able to visualize the nanotube for relatively long periods of time, so we could accurately model its movement," Smith McWilliams said. "Since rhodamine tags coordinated to the BNNT surface were less likely to photobleach (or go dim) than those free in solution, the BNNT appeared as a bright fluorescent signal against a dark background, as you can see in the video. This helped me keep the nanotube in focus throughout the video and enabled our code to accurately track its movement over time."

Scientists at the Hotchkiss Brain Institute (HBI), Alberta Children's Hospital Research Institute (ACHRI), and Owerko Centre at UCalgary's Cumming School of Medicine (CSM) have made a breakthrough discovery that could lead to treatment of Fragile X syndrome (FXS), the leading genetic cause of Autism Spectrum Disorder. The study, involving mouse models, shows promise of translating to treatment for people diagnosed with FXS.

FXS causes intellectual disabilities and hyperactive behaviour, usually more commonly seen in males than females. Children and adults with FXS are missing a protein vital to brain development called FMRP. Among other functions, FMRP helps develop synapses between neurons in the brain.

Dr. Raymond W. Turner, PhD, and members of his study team including Drs. Xiaoqin Zhan, PhD, Hadhimulya Asmara, PhD, and Ning Cheng, PhD, made the discovery while studying ion channels in the brain - special proteins that conduct currents through cells, enabling communication within the brain.

"If I had to make an analogy, it might be akin to insulin and diabetes. With FXS, individuals are missing this protein - let's try putting it back in," says Turner, study lead, and professor in the departments of Cell Biology & Anatomy, and Physiology & Pharmacology at the CSM. "In 30 minutes, the protein distributed throughout the brain, and accomplished what it's supposed to do at the single-cell level."

Unlike injected insulin, which helps someone with diabetes control their blood sugar for a few hours, the FMRP injection helps restore protein levels in the cerebellum and brain for up to one day after the injection. "Hyperactivity was reduced for almost 24 hours," says Zhan, a postdoctoral scholar in the Turner lab. "We did one injection and we tested for it one day later, and three key proteins that are known to be in Fragile X were still at restored normal levels."

In other, unsuccessful attempts to inject mouse models with FMRP to mitigate FXS, scientists used the entire molecule. But Turner and his colleagues used a fragment of FMRP which was able to cross the blood-brain barrier. "It's not a full FMRP molecule at all but rather a fragment with important structural features and functional components that are active in doing things like controlling ion channels or the levels of other proteins," says Cheng, a research associate in the Turner lab.

In the next phase, the researchers will investigate using other parts of the FMRP molecule to mitigate cognitive disorders associated with FXS. "Unlike a lot of drug therapies where you hope you can get your drug to one specific group of cells, FMRP is expressed in just about every cell in the brain, so an all-encompassing wide-based application is what you want," says Turner.

Beyond potential treatments for FXS, the research could help develop treatments to offset behavioural symptoms characteristic of other Autism Spectrum Disorders.

In 2015, Stanford biologist Paul Ehrlich coauthored a study declaring the world's sixth mass extinction was underway. Five years later, Ehrlich and colleagues at other institutions have a grim update: the extinction rate is likely much higher than previously thought and is eroding nature's ability to provide vital services to people. (Watch video: https://www.youtube.com/watch?v=vES3YlXcrrc&feature=youtu.be)

Their new paper, published this week in Proceedings of the National Academy of Sciences, indicates the wildlife trade and other human impacts have wiped out hundreds of species and pushed many more to the brink of extinction at an unprecedented rate.

For perspective, scientists estimate that in the entire twentieth century, at least 543 land vertebrate species went extinct. Ehrlich and his coauthors estimate that nearly the same number of species are likely to go extinct in the next two decades alone.

The trend's cascading effects include an intensification of human health threats, such as COVID-19, according to the researchers. "When humanity exterminates populations and species of other creatures, it is sawing off the limb on which it is sitting, destroying working parts of our own life-support system," said Ehrlich, the Bing Professor of Population Studies, emeritus, at the Stanford School of Humanities and Sciences and a senior fellow, emeritus, at the Stanford Woods Institute for the Environment. "The conservation of endangered species should be elevated to a national and global emergency for governments and institutions, equal to climate disruption to which it is linked."

The study comes in the wake of an April 7 letter from a bipartisan group of senators urging the Trump administration to close markets that sell live animals for food and unregulated wildlife markets, among other measures to stop the trade in illegal wildlife and wildlife products.

Human pressures, such as population growth, habitat destruction, the wildlife trade, pollution and climate change, critically threaten thousands of species around the world. Ecosystems ranging from coral reefs and mangrove forests to jungles and deserts depend on these species' long-evolved relationships to maintain their functioning and make them resilient to change. Without this robustness, ecosystems are less and less able to preserve a stable climate, provide freshwater, pollinate crops and protect humanity from natural disasters and disease.

Final opportunity

To better understand the extinction crisis, the researchers looked at the abundance and distribution of critically endangered species. They found that 515 species of terrestrial vertebrates-- 1.7 percent of all the species they analyzed-- are on the brink of extinction, meaning they have fewer than 1,000 individuals remaining. About half of the species studied have fewer than 250 individuals left. Most of the highly endangered species are concentrated in tropical and subtropical regions that are affected by human encroachment, according to the study.

In addition to rising extinction rates, the cumulative loss of populations - individual, localized groups of a particular species- and geographic range has led to the extinction of more than 237,000 populations of those 515 species since 1900, according the researchers' estimates. With fewer populations, species are unable to serve their function in an ecosystem, which can have rippling effects. For example, when overhunting of sea otters - the main predator of kelp-eating sea urchins - led to kelp die-offs in the 1700s, the kelp-eating sea cow went extinct.

"What we do to deal with the current extinction crisis in the next two decades will define the fate of millions of species," said study lead author Gerardo Ceballos, a senior researcher at the National Autonomous University of Mexico's Institute of Ecology. "We are facing our final opportunity to ensure that the many services nature provides us do not get irretrievably sabotaged."

The loss of endangered creatures could have a domino effect on other species, according to the researchers. The vast majority - 84 percent - of species with populations under 5,000 live in the same areas as species with populations under 1,000. This creates the conditions for a chain reaction in which the extinction of one species destabilizes the ecosystem, putting other species at higher risk of extinction.

"Extinction breeds extinction," the study authors write. Because of this threat, they call for all species with populations under 5,000 to be listed as critically endangered on the
International Union for Conservation of Nature Red List, an international database used to inform conservation action on a global scale.

Timely implications

These findings could aid conservation efforts by highlighting the species and geographic regions that require the most immediate attention. Understanding what species are at risk can also help identify what factors might be most responsible for rising extinction rates.

Among other actions, the researchers propose a global agreement to ban the trade of wild species. They argue the illegal capture or hunting of wild animals for food, pets and medicine is a fundamental ongoing threat not only to species on the brink, but also to human health. COVID-19, which is thought to have originated in bats and been transmitted to humans through another creature in a live animal market, is an example of how the wildlife trade can hurt humans, according to the researchers. They point out that wild animals have transmitted many other infectious diseases to humans and domestic animals in recent decades due to habitat encroachment and wildlife harvesting for food.

"It's up to us to decide what kind of a world we want to leave to coming generations - a sustainable one, or a desolate one in which the civilization we have built disintegrates rather than builds on past successes," said study coauthor Peter Raven, president emeritus of the Missouri Botanical Garden.

Journal

Proceedings of the National Academy of Sciences

There is a world of life on the backs of loggerhead sea turtles, and it's more abundant and diverse than scientists knew.

An international team led by Florida State University researchers found that more than double the number of organisms than previously observed live on the shells of these oceanic reptiles, raising important questions about loggerhead sea turtle ecology and conservation.

The study was published in the journal Diversity.

"This suggests loggerhead turtles are hotspots for organism abundance and biodiversity," said Jeroen Ingels, a researcher with the Florida State University Coastal and Marine Laboratory and lead author of the study. "We suspect that larger organisms that are able to form structures serve as habitats for microscopic creatures and allow for greater levels of abundance and biodiversity."

Researchers discovered this organism diversity by sampling meiofauna, which are organisms roughly between 1 millimeter and about 0.032 millimeters in size.

The researchers specifically focused on a type of aquatic meiofauna called nematodes, also known as roundworms. Previous research had not considered these tiny creatures when surveying the communities of organisms that live on the backs of loggerhead sea turtles.

"To find nematodes on loggerhead turtle carapaces is no surprise, but when we compared their numbers and diversity to those from other hard surfaces or even on marine plant life, we realized their carapaces abound with this microscopic life, the extent to which had hardly been documented in the past," Ingels said.

The FSU researchers, together with a team from Brazil led by Professor Giovani dos Santos and Professor Yirina Valdes, sampled the shells from 24 loggerhead turtles that migrated to Florida's St. George Island in the summer of 2018 to lay eggs.

The researchers examined a forward, middle and posterior section of each shell to see if the different areas had different microscopic communities. To collect their samples, they removed barnacles, then scraped the shells and sponged them down to carefully gather every living creature.

They found thousands of meiofauna organisms. One turtle had more than 146,000 individual organisms living on its carapace. Researchers also found that the posterior section of the shells, closest to the rear flippers, had different communities and a higher diversity of species.

Previous studies of loggerheads had found fewer than 100 different species of any kind living on their shells. By including the nematodes found in this new study, the researchers added at least 111 new species to the list of organisms that can live on the backs of loggerheads. That count doesn't include other types of meiofauna, meaning the number could be even greater.

The research may help explain a paradox around these miniature creatures: How can the same types of aquatic meiofauna be found in different parts of the world, hundreds or even thousands of miles away? Researchers think they are able to travel large distances on the backs of sea turtles, which could help explain their widespread distribution.

The researchers also found that individual turtles harbor significantly different communities of meiofauna living on their shells.

"Were these turtles colonized by microorganisms in different places?" asked Ingels. "It's exciting because it means we may be able to infer where loggerheads have been based on the microscopic communities on their shells."

Tens of thousands of microscopic organisms can colonize loggerhead turtles, which visit remote coasts and beaches during their migration. It makes sense that there would be a connection between the locations frequented by the turtles and the places where the same meiofauna are found, Ingels said. A better understanding of that link could help inform conservation practices for these reptiles.

"Information on key areas used by loggerhead turtles is crucial to inform their management, as it helps identify key threats that they are exposed to," said Mariana Fuentes, a co-author of the article and assistant professor of oceanography in the FSU Department of Earth, Ocean and Atmospheric Science.

Boston, MA - JUUL and similar pod-based e-cigarettes have been popular with teenagers and young adults since they came on the market in 2015, but little has been known about their health effects. A new systematic review led by researchers from Harvard T.H. Chan School of Public Health found that while the products may contain lower levels of harmful ingredients than conventional cigarettes, there is no evidence that even these lower levels are safe for youth. The study also found that the devices' efficient delivery of nicotine fosters greater dependence than other types of e-cigarettes.

This is the first paper to synthesize research findings on pod-based e-cigarettes, said first author Stella Lee, formerly a National Cancer Institute Cancer Prevention postdoctoral fellow in the Department of Social and Behavioral Sciences and currently an assistant professor at Konkuk University in South Korea. "We found that pod-based e-cigarettes have a higher potential to get youth and young adults addicted than other devices," she said. "To prevent this from happening, we need stronger health communication messages that alert people to these findings."

The study will be published online June 1, 2020 in JAMA Pediatrics.

Pod-based e-cigarettes are sleekly designed and easy to conceal. Users pop in replaceable nicotine cartridges that come in appealing flavors like mango and mint. JUUL has dominated retail sales, although other pod-based products are now on the market, including Suorin, Bo, Phix, and Vuse Alto. Recent data have shown that e-cigarette use in adolescents has increased substantially since the introduction of pod-based e-cigarettes, prompting the U.S. Surgeon General to declare youth vaping an epidemic.

For this study, the researchers reviewed recent peer-reviewed scientific literature on pod-based e-cigarettes. They identified 35 English-language articles that presented primary data on pod-based e-cigarettes from June 2015 to June 2019. Studies looked at product design and biological effects, marketing and social media messaging, and population use and perception.

According to the new study, the design of pod-based e-cigarettes ensures the delivery of high doses of nicotine in a low pH form, which is less harsh compared to the higher pH nicotine found in most other e-cigarette brands, thus encouraging deeper inhalation. In one study, the level of nicotine exposure in adolescents (as measured by urinary cotinine) using JUUL or other brands of pod-based e-cigarettes was higher (245 ng/ml) than levels detected in adolescents who smoked regular cigarettes (155 ng/ml). Study findings also suggested that adolescents using pod-based e-cigarettes were more likely than other e-cigarette users to vape daily and to have more symptoms of nicotine dependence.

The researchers also found that pod-based e-cigarette social media marketing campaigns have targeted youth and young adults more than campaigns for other e-cigarette devices. Messages focused less on use of these products as smoking cessation devices and more on ease of use and lifestyle appeal.

The researchers were surprised to find that no study has yet focused on knowledge and perceptions of pod-based e-cigarette use among parents of teenagers, said senior author Andy Tan, assistant professor in the Department of Social and Behavioral Sciences. "Learning parents' perspectives and their information needs around pod-based e-cigarettes is important to address the vaping epidemic among young people," he said. "This is because we will then be able to empower parents with accurate information and tools to communicate with their children that pod-based e-cigarettes are extremely addictive, and to avoid using these products."

In high-pressure experiments, scientists have discovered new forms of the common mineral feldspar. At moderate temperatures, these hitherto unknown variants are stable at pressures of Earth's upper mantle, where common feldspar normally cannot exist. The discovery could change the view at cold subducting plates and the interpretation of seismologic signatures, as the team around DESY scientist Anna Pakhomova and Leonid Dubrovinsky from Bayerisches Geoinstitut in Bayreuth report in the journal Nature Communications.

Feldspars represent a group of rock forming minerals that are highly abundant on Earth and make up roughly 60 per cent of Earth's crust. The most common feldspars are anorthite, (CaSi2Al2O8), albite (NaAlSi3O8), and microcline (KAlSi3O8). At ambient conditions, the aluminium and silicon atoms in the crystal are each bonded to four oxygen atoms, forming AlO4 and SiO4 tetrahedra.

"The behaviour of feldspars under increasing pressure and temperature has been intensively investigated before, with the respect to their fate in Earth's interior," explains Pakhomova. "Feldspars are known to be stable only at pressures of up to 3 Giga-Pascals along the common pressure-temperature profile of the Earth, while they decompose into denser minerals at higher pressures." 3 Giga-Pascals (GPa) are equivalent to 30,000 times the normal air pressure at sea level. "However, under cold conditions feldspars may persist metastably at pressures higher than 3 GPa," adds Pakhomova. "Previous high-pressure structural studies of feldspars at room temperature have shown that the tetrahedral framework of feldspars is preserved up to 10 GPa."

The scientists now subjected common feldspars to pressures of up to 27 GPa and analysed their structure at the Extreme Conditions Beamline P02.2 of DESY's X-ray light source PETRA III and at the Advanced Photon Source (APS) in Chicago. "At pressures above 10 GPa, we have discovered new high-pressure polymorphs of anorthite, albite and microcline," reports Pakhomova. "The phase transitions are induced by severe geometrical distortions of AlO4 and SiO4 tetrahedra, which result in the aluminium and silicon atoms gaining additional neighbouring atoms and also in the formation of denser frameworks based on polyhedra where one aluminium or silicon atom is bonded to four, five or six oxygen atoms."

To investigate the stability of the discovered high-pressure variants of feldspars at high temperatures and their possible persistence in Earth's interior, the scientists performed a series of high-pressure-high-temperature experiments at the Bayerisches Geoinstitut. It turned out that the high-pressure variant of anorthite persists at temperatures up to 600 degrees Celsius at 15 GPa.

"Such pressure-temperature conditions could be found on Earth in the subductions zones - regions where two lithospheric plates collide, one riding over the other," explains Dubrovinsky. "In such geological settings, feldspars are delivered into Earth's interior along with other crustal material by the descending plate. Our results indicate that in cold subduction zones, if the temperature does not rise above 600 degrees, high-pressure phases derived from feldspars could persist at depths corresponding to Earth's upper mantle. This could possibly influence the dynamics and fate of cold subducting lithospheric plates and alter seismological signatures."

One of the earth's biggest allies in the fight against global warming is the world's oceans. Since the industrial revolution, the burning of fossil fuels has caused carbon dioxide, the dominant greenhouse gas, to be released into the atmosphere. Approximately 25% of that carbon dioxide is taken each year from the atmosphere by the world's oceans -- without which, the earth's atmosphere would have a higher greenhouse gas concentration and temperature.

While pulling the anthropogenic, or man-made, carbon dioxide from the atmosphere is good for the earth's system, it leads to problems for the world's oceans as dissolved carbon dioxide becomes carbonic acid and leads to ocean acidification, changing the chemistry of the world's oceans and impacting some of the life forms within it. In particular, the organisms that use calcium to build their carbonate skeletons -- such as corals or mollusks -- will have a harder time under acidified conditions.

To help determine the causes of ocean acidification on both coasts of North America, University of Delaware professor Wei-Jun Cai teamed with the National Oceanic and Atmospheric Administration (NOAA) scientists, as well as professors and professionals from numerous research institutes, to conduct an in-depth study that looks at carbon dioxide uptake and ocean acidification in the coastal oceans of North America.

While ocean acidification in North America has been studied in smaller, specific areas before, this is the first time that researchers have compared data from the east coast, west coast and Gulf of Mexico locations.

Through this work, researchers were able to identify the similarities and differences of ocean acidification on both coasts, as well as point out hot spots that will be particularly vulnerable to ocean acidification in the future. The results of that research were recently published in Nature Communications.

North American coasts

Cai said that in order to adequately research ocean acidification, the work cannot be done by just a few people from one region or even one country. This study involved researchers in the United States, Mexico and Canada.

"In North America, as well as globally, we're trying to get as many countries involved as possible," said Cai, the Mary A.S. Lighthipe Professor in the School of Marine Science and Policy in UD's College of Earth, Ocean and Environment.

For this particular project, the goal was to synthesize their findings to show how ocean acidification works in general for coastal oceans in North America and how those interact with the more localized physical and biological processes.

"Ocean acidification is everywhere, but this paper basically shows that, depending on the location, it can manifest very differently," said Cai.

Sampling the same latitudinal locations on the east and west coasts, as well as the Gulf of Mexico, over the course of several research cruises, allowed the researchers to see different patterns for the east coast and the west coast of North America.

The near equilibrium of ocean waters with the atmospheric carbon dioxide controls the large pattern of ocean acidification on the east coast and Gulf of Mexico while on the west coast, the ocean acidification is enhanced by an additional process known as upwelling.

In the ocean waters of the east coast, the northbound Gulf Stream Current system brings warm, high-salinity waters from the tropics while the southbound Labrador Current brings cold, low-salinity waters from the Arctic and subarctic regions.

Northern waters on the east coast are particularly sensitive to atmospheric carbon dioxide uptake, as the colder ocean temperature allows the ocean to take more carbon dioxide from the atmosphere.

Rising carbon dioxide levels upset the balance of carbonate ions in seawater, making it difficult for some organisms, which have shells composed of the mineral calcium carbonate, to form their shells. Many of the organisms that are affected are critical for ecosystem health.

"The northeast and western coastal communities are very aware of this potential harm that ocean acidification could bring to their region because the marine organisms become more vulnerable sooner in the northern waters," said Cai.

In the east coast's warmer southern waters, the researchers observed lower levels of dissolved inorganic carbon and a higher mineral saturation state, meaning that acidity is lower here when compared to the northern waters.

On the west coast, a section of the ocean is influenced by the California Current System (CCS), which extends from the United States and Canadian border to Baja California. The CCS is characterized by strong, cold currents, and wind-driven upwelling events.

Upwelling brings colder, nutrient-rich subsurface waters to the ocean's surface to replace surface water that has been pushed away by winds. "The water from the subsurface has low pH and high carbon dioxide, which causes stress to the biological system," said co-author Richard Feely of NOAA's Pacific Marine Environmental Laboratory (PMEL). "So the combination of the uptake of anthropogenic carbon dioxide from the atmosphere and the upwelling of CO2-rich low-pH water from below leads to enhanced acidification in this region." This study was the first time that the two coasts were compared side by side to explain their larger features.

"We tried to give the community, particularly the shellfish community or the stakeholders that care about the large-scale ocean acidification, the sense that both the northern waters and at these upwelling centers are most vulnerable to atmospheric CO2 increases," said Cai.

Areas of concern include the CCS and northern-latitude coastal regions, such as the Gulf of Maine in the Atlantic and the Gulf of Alaska in the Pacific, as they are particularly sensitive and vulnerable to anthropogenic carbon dioxide forcing.

The research cruises took place between 2007 and 2018 -- with future ones scheduled for summer of 2020, 2021 and 2022 -- and the researchers would be out on the water for 35 to 40 days at a time.

Cai said that this data collection would not have been possible without the large numbers of international collaborators. He is hopeful that by putting all of this data together, it can be used for future ocean acidification research. Cai also would like to expand this analysis to global scale.

"The different regional collaboration and synthesis efforts to put data together is really important," said Cai. "We need more of this kind of synthesis work to teach us how these different processes create regions of high and low vulnerability of marine life to ocean acidification."