Earth

AMHERST, Mass. - A new analysis of the changing character of runoff, river discharge and other hydrological cycle elements across the North Slope of Alaska reveals significant increases in the proportion of subsurface runoff and cold season discharge, changes the authors say are "consistent with warming and thawing permafrost."

First author and lead climate modeler Michael Rawlins, associate professor of geosciences at the University of Massachusetts Amherst and associate director of its Climate Systems Research Center, says warming is expected to shift the Arctic from a surface water-dominated system to a groundwater-dominated system, with deeper water flow paths through newly thawed soils.

"Our model estimates of permafrost thaw are consistent with the notion that permafrost region ecosystems are shifting from a net sink to a net source of carbon," he says.

Freshwater and riverborne nutrients, mainly dissolved organic carbon, are transported to coastal estuaries and lagoons that lie at the land-sea interface, he explains. Field measurements of river discharge and other hydrological cycle elements in this region are sparse, which requires a modeling approach to quantify the land-ocean flows and their changing character. Details of this investigation into Arctic watersheds between Utqiagvik (formerly Barrow) and just west of the Mackenzie River over the period 1981-2010 are in the current issue of the open access journal, The Cryosphere.

Rawlins explains, "Our model includes a state-of-the-art simulation of soil freeze-thaw cycles that allows us to better understand how permafrost thaw is influencing the magnitude and timing of hydrological flows. Our results point to greater impacts of warming across the Brooks Range, including increasing cold season (November to April) river discharge and a higher proportion of subsurface runoff."

Further, the changing terrestrial inflows may be influencing food web structure within the lagoons, he adds. "Local native communities rely on the fish and other resources in the lagoon ecosystem for their subsistence lifestyle. More than 150 species of migratory birds and waterfowl are supported by the region's food webs, and the lagoons are a rich source of fish for native communities." In particular, Barrow, Nuiqsut and Kaktvik hunters and residents rely on the high productivity of the Beaufort Lagoon systems to support fish and bird populations they live on, Rawlins points out.

In this study, the Permafrost Water Balance Model was validated against available measurements of river discharge and water held in the snow pack. Rawlins and colleagues are developing models and leveraging in situ and remote sensing measurements to better understand flows into the Beaufort Lagoons and predict how permafrost thaw and water cycle intensification will affect lagoon ecosystem dynamics in the future.

The researchers observed significant increases in cold season discharge, such as 134% of the long-term average for the North Slope, and 215% in the Colville River basin, for example. They report a significant increase in the ratio of subsurface runoff to total runoff for the region and for 24 of the 42 study basins, with the change most prevalent across the northern foothills of the Brooks Range. They also observed a decline in terrestrial water storage, which they attribute to losses in soil ice that outweigh gains in soil liquid water storage. The timing of peak spring freshet discharge, the flow of snowmelt into the sea, also has shifted earlier by 4.5 days.

The authors say findings have implications for water, carbon and nutrient cycling in coastal ecosystems and beyond. North Slope rivers are a primary source of new organic nutrients to the Beaufort Sea lagoons, with half of the annual freshwater export occurring in a two-week window following snowmelt in spring. As the climate warms, carbon that has been sequestered for thousands of years in permafrost soils thaws and is mobilized and transferred to river systems, with some emitted to the atmosphere as carbon dioxide and methane, accelerating warming.

Scientists have for the first time shown that it is possible to detect the propagation of seismic waves on the seafloor using submarine telecommunications cables. According to their observations, this existing infrastructure could be used to detect earthquakes, as well as swell and underwater noise. The results are published in the journal Nature Communications on December 18, 2019, by researchers from the CNRS, OCA, IRD and Université Côte d'Azur working together in the Géoazur laboratory, in collaboration with the company Fébus Optics and the Centre de Physique des Particules de Marseille (CNRS/Aix-Marseille Université) (1).

The ocean floor is criss-crossed by 1.2 million kilometres of telecommunications cables (three times the distance from the Earth to the Moon). Made up of optical fibres, they facilitate much of our communication by telephone, SMS and e-mail. And they could soon take on a new role, that of detecting acoustic and seismic waves.

Here, the scientists used a 41 km-long cable deployed off the coast of Toulon in southern France to retrieve data from the sensors of the MEUST-NUMerEnv (2) underwater observatory at a depth of 2500 m. The method they developed takes advantage of small impurities in the optical fibres, which send part of the light they carry back to the transmitter. By stretching or contracting the fibre, the passage of a seismic or acoustic wave alters the distance between these impurities, and thus the backscattered signal, by a tiny amount (3). Yet, they needed to prove that these differences were detectable since, in submarine cables, the optical fibres are surrounded by several insulating layers.

By injecting pulses of light into an optical fibre and analysing the backscattered signal, the team converted the 41 km of optical fibre into more than 6000 seismic sensors. A magnitude 1.9 earthquake that occurred during the trial was detected at each of the measuring points with a sensitivity close to that of a coastal seismic station, even though it was located over 100 km from the cable (Figure 1).

But that's not all: the measuring points are also sensitive to waves that travel through the ocean, such as those produced by swell. The authors recorded the impact of waves on the seafloor near the coast, as well as their effect on the abyssal plain, where they generate 'seismic background noise'. The sensors made it possible to observe for the first time how these very small vibrations, which constantly interact with the Earth's interior, are produced, enabling geophysicists to probe its structure.

The researchers believe that a telecom cable, rather like a string of microphones, could in the same way detect underwater noise produced by ships and cetaceans.

Faced with the logistic and financial challenge of deploying instrumentation on the seafloor, telecom cables could provide a way of improving our understanding of this terra incognita covering two thirds of the Earth's surface, and address a wide range of scientific and societal issues, such as earthquakes, coastal erosion, interaction between life, the oceans and the solid Earth, etc.

A certain number of cables currently in operation will be phased out by telecommunications operators over the coming years. Thanks to this research, they could soon take on a second life.

Sometimes to understand the present, it takes looking to the past. That's the approach University of Central Florida coastal researchers are taking to pinpoint the causes of extreme sea level changes.

Using historical data from tide gauges that line U.S. coasts, the researchers created an extreme sea level indicator that identifies how much of a role different major weather and ocean forces have played in affecting extreme sea levels in coastal areas around the country.

They published their latest findings today in the journal Nature Scientific Data.
The researchers hope that further development of the indicator may one day allow scientists to predict when and where extreme sea level changes will occur.

"What this indicator does, which other indicators do not show, is how weather and climate forces interact with predictable tides to make up high sea levels that can be potentially dangerous," says Thomas Wahl, an assistant professor in UCF's Department of Civil, Environmental and Construction Engineering, a member of UCF's National Center for Integrated Coastal Research and study co-author.

To conduct their study, the researchers examined key contributing factors behind extreme sea level change - mean annual sea level, low frequency tides, and storm surges.

Extreme sea level change, in the context of this study, is when the likelihood for water level thresholds to be exceeded is higher or lower than under normal conditions.
This can have a devastating effect on coastlines, where 40 percent of the U.S. population lives, or more than 126 million people.

Low-frequency tides are higher than average tides that roll in only every so often, such as every 18.6 or every 4.4 years. Average sea level changes each year and can be affected by forces like the El Niño-Southern Oscillation. Storm surges occur from hurricanes and nor'easters.

For Florida's Gulf Coast, such as at Cedar Key, mean sea level and storm surges have been the most responsible for creating periods where extreme sea level events tended to be higher or more frequent, the indicator shows. For the South Atlantic coast, including Jacksonville, Florida, mean sea level and low frequency tides have had a greater effect than variations in storm surges.

This is in stark contrast to the North Atlantic coast, such as Portland, Maine, where low frequency tides have had a greater influence on extreme sea levels than variations in mean sea level or storm surges, especially in the summer.

Knowing these differences can aid policy makers in devising coastal resiliency strategies, says Mamunur Rashid, a postdoctoral research associate in UCF's Department of Civil, Environmental and Construction Engineering, a member of UCF's National Center for Integrated Coastal Research and the study's lead author.

"Hopefully, at some point such information can help guide the development of sustainable coastal adaptation plans," Rashid says.

An international team of geoscientists led by Caltech has used fiber optic communications cables stationed at the bottom of the North Sea as a giant seismic network, tracking both earthquakes and ocean waves.

The project was, in part, a proof of concept. Oceans cover two-thirds of the earth's surface, but placing permanent seismometers under the sea is prohibitively expensive. The fact that the fiber network was able to detect and record a magnitude-8.2 earthquake near Fiji in August 2018 proves the ability of the technology to fill in some of the massive blind spots in the global seismic network, says Caltech graduate student Ethan Williams (MS '19). Williams is the lead author of a study on the project that was published by Nature Communications on Dec. 18.

"Fiber optic communications cables are growing more and more common on the sea floor. Rather than place a whole new device, we can tap into some of this fiber and start observing seismicity immediately," Williams says.

The project relies on a technology called distributing acoustic sensing, or DAS. DAS was developed for energy exploration but has been repurposed for seismology. DAS sensors shoot a beam of light down a fiber optic cable. Tiny imperfections in the cable reflect back miniscule amounts of the light, allowing the imperfections to act as "waypoints." As a seismic wave jostles the fiber cable, the waypoints shift minutely in location, changing the travel time of the reflected light waves and thus allowing scientists to track the progression of the wave. The DAS instrument used in this study was built and operated by a team from Spain's University of Alcalá, led by study co-author Miguel Gonzalez-Herraez.

Recently, Caltech's Zhongwen Zhan (MS '08, PhD '13) began deploying DAS for seismology. For example, he and his colleagues tracked aftershocks from California's Ridgecrest earthquake sequence using fiber that stretches along the state's 395 freeway and also have tapped into the City of Pasadena's fiber network to create a citywide earthquake-detecting network.

"Seafloor DAS is a new frontier of geophysics that may bring orders-of-magnitude more submarine seismic data and a new understanding of the deep Earth's interior and major faults," says Zhan, assistant professor of geophysics and coauthor of study.

For the North Sea project, Williams, Zhan, and their colleagues employed a 40,000-meter section of fiber optic cable that connects a North Sea wind farm to the shore. There are millions of tiny imperfections in the cable, so they averaged out the imperfections in each 10-meter segment, creating an array of more than 4,000 virtual sensors.

"With the flip of a switch, we have an array of 4,000 sensors that would've cost millions to place," Williams says.

Because of the network's fine degree of sensitivity, the North Sea array was able to track tiny, non-earthquake-related seismic noise (or "microseisms") and found evidence that supports a longstanding theory that the microseisms result from ocean waves.

In 1950, mathematician and oceanographer Michael Selwyn Longuet-Higgins theorized that the complex interaction of ocean waves could exert enough of a rolling pressure on the sea floor to generate so-called Scholte waves--a type of seismic wave that occurs at the interface of a liquid and a solid. By tracking both ocean waves and corresponding microseisms, the North Sea array revealed that the microseisms could be the result of ocean-wave interactions.

The Three Gorges Project of the Yangtze River is a large-scale water conservancy project that attracts worldwide attention. Since its completion, it has brought important social and economic benefits in flood control, power generation, shipping, water resource redistribution, and other aspects. However, the advantages and disadvantages of building such a large-scale water conservancy project, as well as its possible impact on the surrounding areas, including many issues related to its climate and environment, have been controversial for a long time.

It is repeatedly questioned whenever rainstorms, floods, or droughts hit the area in or around the reservoir, people always question whether it was affected by the Three Gorges Project. Therefore, it is of great significance to provide timely, objective and effective climate monitoring information for understanding the climate situation of the Three Gorges project area and scientifically evaluating the climate change of the Three Gorges Region of the Yangtze River.

Since 1996, the National Climate Center has issued annual climate reports for the Three Gorges area of the Yangtze River, providing information on climate monitoring, meteorological disasters and climate impacts. "However, previous annual reports have not been officially released. We hope the publication of the annual climate report in 2018 will help people better understand the climate conditions in this region," says Dr. Chen, a researcher at the National Climate Center and the corresponding author of the report, which has recently been published in Atmospheric and Oceanic Science Letters.

This report analyzes in detail the monitoring of various climate elements in the Three Gorges area of the Yangtze River in 2018 and compares them with historical observations. Also, the main weather and climate events of that year are introduced.

"The studies provide basic climate monitoring facts and data for further climate assessment and research," adds Dr Chen. "With the accumulation of data and information, the climatic pattern of the reservoir area and its neighboring localities can be analyzed in detail, and the possible causes of extreme climatic events will be studied in the future."

Yes, you can still give a colleague a regular hug, even after #MeToo. The boundaries are usually a little broader than you might imagine from googling the topic.

"There's little reason for moral panicking. Men and women generally agree on what is okay or not," says Professor Leif Edward Ottesen Kennair at the Norwegian University of Science and Technology's (NTNU) Department of Psychology.

A research group at NTNU has investigated what is perceived as sexual harassment at work. The background for the study is the #MeToo movement and the recent attention on the topic. Most people can rest easy.

"It's not true that men and women can't be friends, work together or even flirt at work after #MeToo," says Andrea Melanie Kessler, first author of a recent article in Sexuality & Culture and PhD candidate in the Department of Psychology at NTNU.

"You might think that everything is illegal now from all the press coverage. But this probably has polemical causes," says Kennair. In other words, these press releases are formulated in a specific way to curb the influence of the #MeToo movement.

Okay and not okay

But something that is okay in one context is not necessarily so in another. The researchers therefore used various scenarios and set different conditions to see when different types of actions were perceived as sexual harassment.

"The debate has often been characterized as either/or. Many people have asked, 'Are we not allowed to do that anymore?'" says co-author and postdoctoral fellow Trond Viggo Grøntvedt.

But what goes depends on several circumstances. So what's okay and what's not okay? A few example might be helpful here. Most people will find them obvious.

A hug to congratulate someone in the workplace will usually not be seen as harassment, but if the person giving the hug slides their hand a little farther down the recipient's back, people will judge it as crossing the line.

The silly joke you told around the lunch table won't necessarily be considered harassment. But it immediately becomes more serious if sexually oriented jokes are told to individuals, and the behaviour repeats itself often.

"A single tactless joke is one thing, but it can get worse when the jokes become repetitive and are then perceived as part of someone's personality," says associate professor Mons Bendixen, also from NTNU's Department of Psychology.

There can be plenty of reasons not to flirt with or date people at work, but you need hardly worry that simply approaching someone will be perceived as sexual harassment. However, it would be worse if a no doesn't stop you, and you just keep going and maybe push harder.

In general, certain behaviours can be perceived as more problematic in a private setting than in a public one.

What definitely is NOT okay is when someone demands sexual services to help another person. This is an extreme behaviour that most people think is wrong. In any case, supervisors need to be more careful about how they behave toward subordinates.

Men also experience harassment

The only point where men and women perceive harassment differently is which gender tends to be the offending party.

"Men often regard women's actions as less harassing than men's. Women don't distinguish between the sexes that way," says Kessler.

Thus, men more often regard men's behaviour as worse than women's behaviour, even under seemingly equal conditions. This is something that the researchers plan to explore in future studies.

It is important to note that these study results apply to Norwegian conditions. By international measures, Norway is generally a gender-equal and sexually liberal country, although this does not apply everywhere. But we don't know for sure.

"As far as we know, this is the only study in the field that also asks about women's harassment of men," says Kennair.

The notion that it's women who are sexually harassed almost exclusively is widespread and simply wrong, along with the idea that only opposite-sex harassment takes place.

"Previous research in Norway shows that men and women experience harassment equally often, both as students in higher education and in working life," Bendixen says.

The results are largely in line with what the researchers expected.

Encouraging

Kessler believes the results are encouraging.

The #MeToo movement has undoubtedly generated necessary attention about matters that most people think are reprehensible. But it may also have created unnecessary limits to normal behaviour.

"For example, we know of cases where men are reluctant to become mentors for women because they want to avoid suspicion. This can ruin opportunities for some women," says Kessler.

Sexual harassment is a significant problem. In order to reduce sexual harassment, it is important to clarify where the boundaries are and to start thinking about sexual harassment in a less stereotypical way.

The research group collected data for their study from almost 500 men and women with different backgrounds and an average age of 33. The participants to a great extent related their own personal experiences from work. Ida Bjørkheim and Idun Drejer collected the data as part of their thesis.

The human immunodeficiency virus, or HIV, wages war in our bodies using a strategy evolved over millions of years that turns our own cellular machines against themselves. Despite massive strides in understanding the disease, there are still important gaps. For years, scientists at the University of Utah wished there was a way to visualize how the virus and its molecules interact with human cells in real time. So, a research group developed one.

The new method uses interferometry to capture extremely high-resolution visualizations of millions of molecules moving across viscous gels or a plasma membrane. Ipsita Saha, physics doctoral candidate and lead author of the study, developed a correlation analysis that theoretically explained how the interferometry microscope could distinguish between two types of movement--flow and diffusion--and she and Senior Author Saveez Saffarian verified it experimentally. The method brings us one step closer to visualizing how molecules interact in an actual living cell.

"There are already methods that capture how molecules flow and diffuse in two dimensions. We wanted to see what is happening across the entire cellular environment. How are these molecules working? What kind of interactions are taking place?" said Saha, who is also affiliated with the Center for Cell and Genome Science (CCGS) at the U.

"So far, we've been left to just imagine these interactions. We have very limited ways of actually going into the cell and observing how all of these molecules are dancing together at the same time," said Saffarian, associate professor of physics, adjunct assistant professor of biology and affiliate of the CCGS. "We really needed to generate higher-resolution methods that can look at the dynamics of biological molecules."

The study published in the journal PLOS ONE on December 18, 2019.

Flow and diffusion

Cells function like an efficient office. Proteins and other molecules carry out tasks, develop products, communicate with each other and move around, even leaving their particular cell to wade into the wider world. Movement is crucial for molecules to find and interact with each other and their environment. This study aimed to distinguish between two types of movements: flow and diffusion.

Molecules flow when they have a bias toward moving in a certain direction. Diffusion is when molecules move around randomly. To understand how cells or viruses function, it's important to understand the mechanics of how they move.

"Are these molecules carrying different things from one place to another, or are there other processes going on?" said Saha. "This method specifically can differentiate between flow and diffusion in three dimensions."

The researchers used an interferometry microscope, which measures the distance that light travels over nanoscales. Molecules emit photons that travel as light waves, each with specific amplitudes and frequencies. For the experiment, the microscope split a beam of light into two beams that traveled down different paths, eventually coming back to meet each other. These beams combine in a prism, and three separate reflections of their combination are imaged on three cameras. The interference is such that if a molecule moves 80 nanometers, its image is shifted onto a different camera. This is extremely high resolution--a human red blood cell is about 7,000 nanometers across. The researchers measured the resolution in voxels, which are pixels in three dimensions.

Saha and Saffarian created a sucrose gel injected with quantum dots--manmade nanoscale crystals that conduct electrons. The quantum dots produce a signal that the microscope can detect. By first learning how quantum dots move in the gel, the scientists validated their technique, which could then be applied to how proteins are moving inside a cell. They cooled the gel to room temperature to slow the substance down to a rate that the cameras could capture.

"You can actually see if molecules are going in a particular direction or if they're moving randomly. And you can do this in very, very small voxels across a large cross section of the sample, which has a huge wealth of information," said Saffarian. The scientists used the Center for High Performance Computing at the U to process the massive amounts of data.

The researchers measured how long these light waves "remembered" each other by calculating the probability of how long the waves would retain their amplitude and frequency, called coherence. Light emitted from the same molecule will show up in the cameras with the same coherence. They used the correlation function to figure out how the molecules were moving and in what direction. If the split light beams travel on separate paths less than 10 microns away from each other, they remember they came from the same molecule. When the light beams meet again, they'll recombine with that knowledge. If they have no knowledge of each other, they have a 30% probability of showing up in any of the three cameras. If they do remember each other, they have a 100% probability of showing up in one camera, but a 0% probability of showing up in the others. This method measures light emitted from millions of molecules at once, making this method ideal for studying flow and diffusion across cells and tissues.

Improving the technology

While this method detects movement across viscous gels or plasma membranes, it is unable to create a map of particles moving across an actual cell. However, Saha and Saffarian are now collaborating with researchers at ThermoFisher Scientific (FEI) in Germany to build a prototype of a microscope with much faster detectors that will be able to capture movement within living cells. They are part of a patent application for the technology and will analyze the data from the experiments.

"We can already use this method for slow processes, but in our lab, we are biologists at some level. We want to really understand how biology works, and the incentive behind all of this method development is to understand, what is the crazy dance of molecules within cells and tissues that allows really exotic biology to move forward? To get there, we need much faster detectors," Saffarian said.

Leading a double life as both solids and liquids, liquid crystals occupy center stage for creating smaller, faster and more efficient technologies. Even at the level of single particles, liquid crystals can bend light and react to external forces, like electric fields or physical pushes and pulls. And so, a tiny quantity of liquid crystals is usually enough to achieve high performance in many applications, ranging from monitor screens to solar panels.

But in order to fully tap into a liquid crystal's wondrous properties, its constituent particles must be systematically assembled.

In a new study, Texas A&M University researchers have discovered that applying a small difference in temperature to a watered-down mixture of a compound called zirconium phosphate initiates its liquid crystallization. As zirconium phosphate particles move toward warmer temperatures, they start aligning themselves with each other and eventually turn into pure liquid crystals, the researchers said.

"Ours is the first proof-of-concept study to show that temperature gradient is an effective, yet simple, tool to assemble high-quality liquid crystals," said Dr. Zhengdong Cheng, professor in the Artie McFerrin Department of Chemical Engineering. "Also, our results indicate that we can move liquid crystals by just varying temperature, a property that can potentially be used to transport liquid crystal particles from one place to another, thus paving the way for applications beyond those that are commonly associated with liquid crystals today."

The researchers reported their findings in the October issue of the journal ACS Nano.

Liquid crystals represent a state of matter that lie somewhere between solids and liquids. Like molecules in solids that form crystals, those in liquid crystals are arranged in a semi-systematic fashion, like cars in a partly-full parking lot. But liquid crystals are also runny and can assume any shape like liquids. Furthermore, in their liquid crystal avatar, materials often show exotic properties. For example, they split up light beams or change their molecular alignments in response to electric fields.

But whether or not a material can assume a liquid crystal state depends on the overall shape of their constituent particles. Substances made up of spherical particles do not form liquid crystals. On the other hand, materials consisting of particles that are elongated like rods or flat like discs do form liquid crystals. Cheng and his team were particularly interested in zirconium phosphate because its disc-like particles have the ability to self-assemble into larger, flat 2D structures in their liquid crystalline state.

"Many particles found in nature, like red blood cells, nucleosomes and clay particles, are disc shaped and under the right circumstances, they can self-assemble into liquid crystals," said Cheng. "So, we used zirconium phosphate as a proxy to investigate if there is a way to experimentally control the liquid crystallization of these particles."

Zirconium phosphate has been shown to assemble into liquid crystals on its own if large enough quantities are added to water. But the resulting liquid crystals often have defects and are unstable. So, Cheng and his team came up with an alternative approach.

Cheng had shown previously that applying a temperature difference could make spherical particles assemble into clumps of crystals. Using the same principle, his team investigated if varying temperatures could be used to assemble zirconium phosphate into liquid crystals.

For their experiments, the Texas A&M team made a mixture of zirconium phosphate and water and filled it into thin, two-inch-long tubes, making sure that the quantity of zirconium phosphate was small enough to not trigger automatic liquid crystallization. Next, they applied heat in such a way that the temperature difference between either ends of the tube was around 10 degrees.

Within an hour, Cheng and his team found that the zirconium phosphate particles in the cooler end of the tube began to creep toward the warmer end, triggering liquid crystallization from the tube's warmer end.

"Just like water in a boiling pot circulates from the bottom where it is hot to the top of the container where it's cold, water in our tubes was also circulating from warmer to cooler temperatures," said Dali Huang, graduate student in the Texas A&M College of Engineering and a primary author of the study. "Accordingly, the zirconium phosphate particles also moved in the direction of the water flow and arranged themselves into liquid crystals. "The researchers speculated that the push from the flowing water helps zirconium phosphate particles to position themselves systematically until they form liquid crystals. Also, they found that the liquid crystals created with temperature gradients were less defective than those formed by other methods.

Cheng noted that their findings open new doors for use in a variety of contexts.

"By virtue of their shape, disc-shaped particles have a larger surface area compared to their volume," said Cheng. "If we think of the next generation of biomedical devices, for example, we can potentially take advantage of this geometry to load medicinal particles on their flat surfaces and then vary temperature to transport them to target a specific part of the body."

EAST LANSING, Mich. - The vast majority of children living with HIV today are in sub-Saharan Africa. While early antiretroviral therapy, or ART, has ensured less deadly outcomes for children living with and exposed to HIV, studies show the virus still may affect the brain. HIV may disrupt neurodevelopment, affecting how children learn, reason and function.

That's why Michael Boivin, professor and director of the Psychiatry Research Program in the Michigan State University College of Osteopathic Medicine, set out to understand exactly how HIV impacts children's neuropsychological development in a two-year longitudinal study, published in Clinical Infectious Diseases.

The research was supported in part by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

Boivin and his colleagues evaluated the neuropsychological development of three groups of children aged 5 to 11: those who acquired HIV perinatally and were treated with ART, those exposed but HIV-negative, and those who were never exposed. The research took place at six study sites across four countries in sub-Saharan Africa for a robust view of how HIV is affecting children in the region.

To date, it's the first well-validated, multi-site neuropsychological evaluation of African school-aged children affected by HIV.

What the researchers discovered through various assessments was that even in the face of early treatment and good clinical care, there are still significant neuropsychological problems for children living with HIV.

"These children came into the study with a deficit compared to their counterparts," Boivin said. "It stayed about the same throughout the two years, except in one important area: reasoning and planning. On that specific test domain, the children living with HIV failed to progress over time."

In other words, the gap between infected and HIV-negative children grew in the planning and reasoning area over the study period. Typically, these abilities tend to blossom in the school-aged years in healthy children.

"This is the most important cognitive function for the future of children living with HIV in terms of their likelihood of taking their medications, making good decisions, abstaining from risky behaviors like early sexual activity, psychosocial issues and school-related achievement," Boivin said.

The bottom line? Early medical treatment, started as early as 6 months of age, is probably not enough to address the neurocognitive deficits associated with HIV, even though it helps keep children alive and healthier than they would be without treatment. In these children, treatment should be started even earlier to improve long-term neurocognitive outcomes.

"We're going to have to complement the long-term care and support with actual behavioral interventions," Boivin said.

That's something Boivin and his colleagues are already working on. Earlier this year, Boivin received a 5-year, $3.2 million NIH grant to continue his work with children affected by HIV in Uganda and Malawi.

Through this grant, researchers will investigate how MSU-developed computer cognitive games can serve as tools for neurocognitive evaluation, enrichment and potentially rehabilitation.

Boivin hopes that the results of both of these studies will help make this model of neuropsychological evaluation a considered part of the cost benefit of care for kids affected by HIV.

"Often it's overlooked or seen as an afterthought, but unlike other areas of medical follow up, neuropsychological evaluation really gets at how well the kids are going to adapt and function in school, at home, in the community and in society in general," Boivin said. "It's really what links us most directly to the human burden of disease."

Bottom Line: Marijuana use in electronic cigarettes increased among U.S. middle and high school students from 2017 to 2018. This observational study analyzed responses from 38,000 students in the sixth to 12th grades on the National Youth Tobacco Survey. Researchers report that among all students, the proportion who reported ever using marijuana in an e-cigarette increased from 11.1% in 2017 to 14.7% in 2018, with the increases seen among some demographic groups, including male and female students, adolescents 13 to 17, high-schoolers, and non-Hispanic white and Hispanic students. In 2018, 42.7% of students who ever used e-cigarettes, 53.5% of current e-cigarette users, and 71.6% of multiple tobacco product users reported ever using marijuana in e-cigarettes. A limitation of the study is that the information was self-reported. Studies about the short- and long-term health effects of using marijuana in e-cigarettes are needed.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

Author: Hongying Dai, Ph.D., University of Nebraska Medical Center, Omaha

(doi:10.1001/jama.2019.19571)

Editor's Note: The article includes funding/support disclosures. Please see the article for additional information, including author contributions and affiliations, financial disclosures, funding and support, etc.

Findings from the 2019 Monitoring the Future (MTF) survey demonstrate the appeal of vaping to teens, as seen in the increased prevalence of marijuana use as well as nicotine vaping. Results from the 45th annual MTF survey, a nationally representative sample of eighth, 10th and 12th graders in hundreds of U.S. schools, were announced today by the director of the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health, along with the University of Michigan scientist who leads the research team. The self-report survey is given annually to students who respond to questions about their drug use and attitudes.

Past year vaping of marijuana, which has more than doubled in the past two years, was reported at 20.8% among 12th graders, with 10th graders not far behind at 19.4% and eighth graders at 7.0%. Past month marijuana vaping among 12th graders nearly doubled in a single year to 14% from 7.5%-the second largest one-year jump ever tracked for any substance in the history of the survey. (The largest was from 2017-2018 with past month nicotine vaping among 12th graders). For the first time, the survey measured daily marijuana vaping, which was reported at 3.5% among 12th graders, 3.0% among 10th graders, and 0.8% among eighth graders. The MTF investigators documented more detailed findings on teen vaping of marijuana in a research letter released today in the Journal of the American Medical Association. High rates of nicotine vaping reported in the MTF survey were released in September.

Marijuana continues to be the most commonly used illicit drug by adolescents. After remaining mostly stable for many years, daily use of marijuana went up significantly since 2018 among eighth and 10th graders-now at 1.3% and 4.8% respectively. However, overall past year marijuana use rates remain steady among teens (35.7% among 12th graders; 28.8% among 10th graders; and 11.8% among eighth graders).

Past year rates of any illicit drug use, other than marijuana, remain relatively low among 12th graders; past year use was 3.6% for LSD; 3.3% for synthetic cannabinoids; 2.2% for both cocaine and MDMA (ecstasy); and 0.4% for heroin. Other drug use, including the misuse of prescription medicines and the use of alcohol as well as tobacco cigarettes, continues to decline.

"We are heartened to see the continuing decline in the use of many drugs, particularly non-medical use of prescription opioids; however, teens are clearly attracted to vaping products, which are often concentrated amounts of drugs disguised as electronic gadgets," said NIDA Director Dr. Nora Volkow. "Their growing popularity threatens to undo years of progress protecting the health of adolescents in the U.S."

Other highlights:

Prescription Drugs

Past year rates of misuse of the opioid pain reliever Oxycontin dropped significantly among 12th graders over the past five years, with only 1.7% reporting in 2019-the lowest level of use since it was first measured in 2002 (at 4.0%).

Past year rates of misuse of the opioid pain reliever Vicodin is now at 1.1% for both 12th graders and 10th graders. For 12th graders, it is a significant drop from 2018 and the lowest rate since it was first measured in 2002 (at 9.6%). These rates represent a significant five-year decline in these two grades.

Past year misuse of the ADHD medication Adderall saw a significant decline over the past five years among 10th and 12th graders-from 4.6% to 3.1% for 10th graders and from 6.8% to 3.9%, for 12th graders. However, there was a significant increase among eighth graders?now reported to be 2.5%, up from 1.3% in 2014.

Tobacco Products

Use of regular cigarettes continues to decline among teens, especially among 12th graders who had a significant decline in past month use, now at 5.7%, down from 7.6% last year and 13.6% five years ago.

In 2019, 2.4% of 12th graders said they smoked cigarettes daily, a significant decline from 3.6% in 2018. However, 11.7% said they vaped nicotine daily in 2019, the first year daily vaping use has been measured.

One in 4 12th graders say they vaped nicotine in the past month, along with 1 in 5 10th graders, and nearly 1 in 10 eighth graders.

Many teens say they vape for the flavor, to experiment, for social reasons, or to feel good. However, from 2018-2019, the number of 12th graders saying they vape because they are "hooked" more than doubled to 8.1%, up from 3.6%. It is important to note that not all teens know what is in the products they are vaping.

Alcohol

Alcohol use (past year) saw a significant five-year drop among 10th and 12th graders in 2019, now at 37.7% and 52.1%.

There was also a five-year decrease in binge drinking in the 10th and 12th grades. The survey reports that 14.4% of 12th graders said they binge drank in 2019 compared to 19.4% in 2014. Among 10th graders, 8.5% reported binge drinking compared to 12.6% five years ago. Binge drinking is defined as five or more drinks in a row in the past two weeks.

With countries such as Iceland, Costa Rica, New Zealand, and Norway adopting green energy practices, renewable energy now accounts for a third of the world's power. As this trend continues, more and more countries are looking to offshore energy sources to produce this renewable energy. In an Opinion publishing December 17 in the journal Trends in Ecology and Evolution, researchers identify situations where green technology such as wind turbines, wave energy converters, and other marine renewable energy devices (MREDs) have had negative consequences on marine life.

While the researchers don't want to slow down active responses to climate change, they do encourage those making the decision to implement MREDs into marine habitats to consider the impact of this technology, such as head trauma and hearing loss, on marine animals before beginning construction.

"When people put a wind farm in their back yard, neighbors might complain that it's ugly and want it moved," says first author Andrew Wright (@marinebrit), an ocean and ecosystem scientist at the Natural Sciences and Engineering Research Council of Canada. "So, they think, why not put it off shore where we can't see it and then there's no problems? The assumption there is that it's just an aesthetic problem. But there's a lot more to it."

Green technology used on land, such as the wind farms mentioned by Wright, has had negative impacts on birds and bats, who collide into the massive spinning blades during migration or while on their night flights. Similarly, when spinning objects like wave energy converters are built under water, marine animals like dolphins and porpoises can be hit by the turning blades, causing blunt-force trauma.

MREDs are not only physically dangerous. They're also noisy to construct, which can disrupt the echolocation some marine mammals use for hunting and navigating.

For example, the Taiwanese white dolphin, an endangered species that makes its home in a densely populated and heavily industrialized region, is facing extensive windfarm developments in its range. Unable to escape the construction noise in their increasingly shrinking habitat, the dolphins will likely suffer from hearing loss and chronic stress.

"Installing renewable energy sources in the ocean is a loud operation. I would compare building MREDs to living next to a construction site. Think about what it'd be like to live next to all those jackhammers and power drills," says Wright. "I don't think a lot of people appreciate that when it's offshore, it may be silent for humans, but if they stick their head under water where the animals live, it's much, much louder."

Even after construction is finished, the noise produced by MREDs can still be harmful. While some technologies are relatively quiet, others can cause low-frequency (i.e., pitch) sounds that echo through the water, obscuring the sounds of animals such as the critically endangered North Atlantic right whales, who, like dolphins, rely on their ears to explore their world.

"Renewable energy doesn't run out like fossil fuels, so it's easy to be convinced that it's free energy," Wright says. "But it can come at the cost of marine mammals and other marine life if we don't consider them when implementing new technologies."

Wright hopes this paper will lead to just that: consideration. He and his co-authors do support the implementation of MREDs, as long as the lives of both humans and animals are considered first. For instance, building MREDs in a location that's home to species with large populations or species that can evacuate when needed is likely going to have only a minor impact. When dealing in isolated locations with smaller populations of marine mammals, it becomes a lot more complicated.

"We don't want to slow anything down. We just want everyone to be a bit more strategic in their efforts," says Wright. "We all agree that climate change is a big problem that needs solutions, but it's important to make sure that the solutions we implement don't have too much collateral damage along the way."

Bottom Line: Researchers analyzed changes in the proportion of drug overdose deaths involving opioids that were certified as suicide, unintentional or of undetermined intent in this observational study. Using 2000-2017 mortality data, researchers report 47,506 total opioid deaths (excluding homicides) in 2017: 90.6% were unintentional deaths, 4% were suicides and 5.4% were of undetermined intent. Between 2000 and 2017, the percentage of opioid-related deaths that were suicides declined from 9% to 4%; unintentional opioid-related deaths increased from 73.8% to 90.6%; and deaths of undetermined intent decreased from 17.2% to 5.4%. There were significant increases in opioid-related suicide rates for males and females, all racial/ethnic groups, and all age groups except those between the ages of 35 and 44. Between 2000 and 2017, the rate of opioid-related deaths increased from 2.2 to 13.2 per 100,000 people for unintentional deaths and from 0.27 to 0.58 per 100,000 for suicides with no significant change in the rate for deaths of undetermined intent. Limitations of the study include fewer drug overdose deaths that didn't have information on the specific drug because of increased toxicological screening and that may have contributed to the increase in opioid-related deaths over time, as well as uncertainty about determinations made by coroners or medical examiners about the manner of death.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

Authors: Mark Olfson, M.D., M.P.H., Columbia University Vagelos College of Physicians and Surgeons, New York, and coauthors.

(doi:10.1001/jama.2019.16566)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention. In the field of climate and climate change, we have witnessed multiple remarkable achievements by Chinese scientists.

The review covers and summarizes the contributions of the Chinese scientists from the six aspects. First, important progress in general climate studies is introduced. Chinese scientists made statistical analyses of climate changes in temperature and precipitation (drought and flood) based on data of large time-scale. They systematically studied the formation mechanisms of climate disasters and extreme climate events, which laid the physical foundation for climate disaster prediction in China.

The Tibetan Plateau has important influences on the evolution of the global atmospheric circulation and plays an important role in climate change and climatic anomalies in China dynamically and thermodynamically. Chinese scientists have made pioneering and original scientific achievements in this field. Monsoon is an important circulation system in the global climate system.

The interannual and interdecadal variations of the East Asian monsoon have a major impact on climate disasters. The research in this field is dominated by Chinese scientists in the world. China is the first country to study the impact of teleconnection oscillation and westerlies on the climate and has made remarkable achievements.

The developments of climate dynamics and climate system models constitute the theoretical basis and numerical tools for modern climatology research. The development and application of the climate system model is an important direction of modern climatology. Chinese scientists have established a theoretical framework for climate dynamics. Since the late 1970s, China has begun to develop climate models and apply them to simulation studies of climate processes.

One of the most important progress in atmospheric sciences in the 20th century is that scientists and governments all around the world have realized the human-induced global warming and its influence on the global environment. Additionally, they have realized that climate change is a result of the interactions among multi-spheres in the Earth's system. The research on climate and environmental evolution in China conducted by Chinese scientists have promoted the continuous progress of domestic and international research on climate change and contributed to the progress of global change research. In the field of climate change, Chinese scientists have reaped numerous world-leading fruits. Thus, the right to speak internationally is becoming more and more powerful.

Recent decades have witnessed the increasingly profound impact of climate change on people's lives. Looking ahead, there still remain many unresolved problems that will lead the way in the future research on the climate and the climate change. (1) Based on existing results, a scientific and reasonable complete physical image needs to be constituted by questions of how the dynamic and thermodynamic effects of the land-atmosphere coupled process on the Qinghai-Tibet Plateau affect Asian monsoons and multi-scale disaster weather systems, etc. (2) The impact of the interaction of different "spheres" on the anomalies of the East Asian monsoon climate and the feedback effects of East Asian monsoon on global climate change deserves in-depth studies. (3) There is still a big gap between the current climate model in China and the international leading model. It is necessary to develop high-resolution land-atmosphere coupled climate system models, making Chinese comprehensive level of climate model development and simulation rank among the top in the world. (4) How much global warming caused by greenhouse gas generated by human activities will be produced is still a problem that has not been clarified. What are the different responses of global warming to climate variability in different regions of China? The warming of different regions of China, the attribution analysis of climate change in different regions, and the differences between these factors and the global climate change factors are all urgent scientific questions to answer. (5) In the context of global warming, how to study the causes and changes of extreme weather and climate events from the perspective of multi-factor synergy is a difficult and important point in international climate research.

CSIRO research has found global warming will make it more difficult to predict multi-year global climate variations, a consequence of changes to long-term climate variability patterns in the Pacific Ocean.

The results, published today in Nature Climate Change, shed light on how the Pacific Decadal Oscillation (PDO) was responding to a changing climate, with implications for assessing multi-year risks to marine ecosystems, fisheries and agriculture.

The PDO is a decadal-spanning pattern of Pacific climate variability, operating in the Pacific Ocean, and exerting a substantial influence on global climate and marine conditions from the US and Japan to Australia and New Zealand.

The PDO has two phases, cold and warm.

During a PDO cold phase, the tropical Pacific Ocean temperatures are lower, and Australia's decadal rainfall tends to be above average.

Under warm phases, the opposite occurs, with below average rainfall.

The PDO also modulates climate variations such as El Niño, which causes warm and dry conditions north west and east of Australia and is associated with heightened risk of bushfire and drought.

"When we're in a Pacific Decadal Oscillation cold phase, El Niño is more likely to affect Australian rainfall and surface temperatures," researcher Dr Wenju Cai from CSIRO's Centre for Southern Hemisphere Oceans Research (CSHOR) said.

"With a less predictable PDO, it may be more difficult to predict the likely impact of El Niño."

The research found that the PDO would become less predictable as the planet warms, because warming conditions result in a significantly shortened PDO lifespan.

An oceanic feature called upper ocean stratification causes upper ocean layers to warm faster than deeper ones.

Stratification intensifies under warming.

Rossby waves, an underwater wave feature, move faster in more stratified waters, which shortens the PDO lifespan further and reduces the time it has to gain strength and intensity.

Using various greenhouse gas emissions scenarios, researchers found that the predictability of the PDO sharply declined depending on the intensity of warming.

Although PDO cold phases are associated with colder tropical Pacific temperatures, cold phases manifest as warmer sea surface temperatures in the Tasman Sea and off southeast Australia.

Elevated sea surface temperatures can stimulate high production in fisheries, but may negatively affect other ecosystems through marine heatwaves and coral bleaching.

The results pose a challenge for predicting regional climates on multi-year timescales, as well as year-on-year climate variability.

"In our current climate, we can potentially predict the PDO approximately eight years ahead. That lead time will likely be reduced to three years by the end of the 21st century," Dr Cai said.

The ability to accurately forecast the PDO helps decision-makers understand and plan for warm and cold oceanic conditions.

This knowledge can be used by fisheries and aquaculture sectors to manage production risks associated with these conditions, and likewise can support strategic and investment scale decisions by these sectors, as well as insurers, especially in assessing multi-year risks.

Long-term forecasts can also assist in planning conservation actions and harvesting levels that build the resilience of marine ecosystems to biological changes associated with environmental conditions.

"Because the Pacific Decadal Oscillation can span for some time - from a season, six months, or up to a decade or even more - the ability to predict changes to marine ecosystems on these timescales can help plan responses to shifts in fish distribution or abundance," Dr Cai said.

CSIRO is currently developing skilled forecasting models to help guide decision makers manage risk under a warming climate.

"The findings will help us to mitigate the negative impact of greenhouse warming on the PDO. The next step will be to improve model systems to fully realise the potential predictability of the PDO," Dr Cai said.

"Many people are familiar with the role that the El Niño-Southern Oscillation plays in climate but might be surprised that there are bigger forces at play like the PDO, which influences our marine environment, as well as climate extremes."

The Centre for Southern Hemisphere Oceans Research is a $20 million five-year collaboration between CSIRO, Qingdao National Laboratory for Marine Science and Technology with the University of Tasmania and University of New South Wales.