Rest isn't best: Getting kids back to school sooner after a concussion can mean a faster recovery

Contrary to popular belief, rest may not always be the best cure after a concussion, new study published in JAMA Network Open finds. In fact, an early return to school may be associated with a lower symptom burden after suffering a concussion and, ultimately, faster recovery.

"We know that absence from school can be detrimental to youth in many ways and for many reasons," says Christopher Vaughan, Psy.D., neuropsychologist at Children's National Hospital and the study's lead author. "The results of this study found that, in general, an earlier return to school after a concussion was associated with better outcomes. This helps us feel reassured that returning to some normal activities after a concussion -- like going to school -- is ultimately beneficial."

In this cohort study, data from over 1,600 youth aged 5 to 18 were collected across nine pediatric emergency departments in Canada. Because of the large sample size, many factors associated with greater symptom burden and prolonged recovery were first accounted for through the complex statistical approach used to examine the data. The authors found that an early return to school was associated with a lower symptom burden 14 days post-injury in the 8 to 12 and 13 to 18-year-old age groups.

"Clinicians can now confidently inform families that missing at least some school after a concussion is common, often between 2 and 5 days, with older kids typically missing more school," Dr. Vaughan says. "But the earlier a child can return to school with good symptom management strategies and with appropriate academic supports, the better that we think that their recovery will be."

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Tumultuous migration on the edge of the Hot Neptune Desert

All kinds of exoplanets orbit very close to their star. Some look like the Earth, others like Jupiter. Very few, however, are similar to Neptune. Why this anomaly in the distribution of exoplanets? Researchers from the University of Geneva (UNIGE) and the National Centre of Competence in Research (NCCR) PlanetS have observed a sample of planets located at the edge of this Hot Neptune Desert to understand its creation. Using a technique combining the two main methods of studying exoplanets (radial velocities and transits), they were able to establish that a part of these exoplanets has migrated in a turbulent way near their star, which pushed them out of the orbital plane where they were formed. These results are published in the specialized journal Astronomy & Astrophysics.

Since the discovery of the first exoplanet in 1995, researchers have detected more than 5'000 planets in our galactic neighborhood, most of them orbiting very close to their star. If the diversity of these new worlds ranges from gas giants the size of Jupiter or Saturn to smaller planets the size of Mercury, including rocky planets larger than the Earth, gas planets the size of Neptune seem to be missing. Astronomers call this empty ''box'' in the distribution of close-in planets the Hot Neptune Desert.

''The distribution of planets close to their star is shaped by a complex interaction between atmospheric and dynamical processes, i.e. the motions of the planets over time,'' comments Vincent Bourrier, assistant professor in the Department of Astronomy at the UNIGE Faculty of Science. ''Today we have several hypotheses to explain this desert but nothing is certain yet and the mystery remains''. Did these planets lose their atmosphere entirely, eroded by the intense radiation of their star? Did they migrate from their birthplace to the outer parts of the system by a different mechanism than other types of planets, preventing them from reaching the same close orbits?

Disrupted migration

In a recent work, a team of scientists from the UNIGE brings some answers by looking at the orbital architecture of the planets located at the edge of this desert. By surveying fourteen planets around this area, ranging from small planets to gas giants, the astronomers were interested in the way their orbits are oriented with respect to the axis of rotation of their star. This information makes it possible to distinguish the processes of soft migration (the planets move in the equatorial plane of their star where they were formed) from the processes of disruptive migration (the planets migrate and are pushed out of the plane where they were formed).

The researchers were able to show that most of the planets in their sample have an orbit misaligned with the stellar equator. ''We found that three-quarters of these planets have a polar orbit (they rotate above the poles of their star), which is a larger fraction than for planets further away from the desert. This reflects the role of disruptive migration processes in the formation of the desert,'' summarizes Vincent Bourrier, first author.

Two methods combined

To achieve these results, the scientists used the radial velocity method and the transit method, which are employed to study exoplanets. ''Analyzing the radial velocities during the transit of a planet allows us to determine if it orbits around the stellar equator, around the poles, or if the system is in an intermediate configuration, because different architectures will produce different signatures,'' explains Omar Attia, a doctoral student in the Department of Astronomy at the UNIGE Faculty of Science and second author of the study. These two methods were combined with data obtained with the HARPS and HARPS-North spectrographs, created at UNIGE and located on the 3.6m telescope of ESO (European Southern Observatory) and TNG (Telescopio Nazionale Galileo).

The path to understand all of the mechanisms involved in the formation of the Hot Neptune Desert is still long. It will be necessary in particular to explore with this technique the smallest planets at the edge of the desert, today difficult to access even with instruments of last generation such as the spectrograph ESPRESSO, built by the UNIGE and installed on the largest European telescopes. It will be necessary to wait for the commissioning of the ELT, the 39-meter super telescope of ESO, planned for 2027.

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17-pound meteorite discovered in Antarctica

Antarctica is a tough place to work, for obvious reasons -- it's bitterly cold, remote, and wild. However, it's one of the best places in the world to hunt for meteorites. That's partly because Antarctica is a desert, and its dry climate limits the degree of weathering the meteorites experience. On top of the dry conditions, the landscape is ideal for meteorite hunting: the black space rocks stand out clearly against snowy fields. Even when meteorites sink into the ice, the glaciers' churning motion against the rock below helps re-expose the meteorites near the surface of the continent's blue ice fields.

An international team of researchers who just got back from Antarctica can attest to the continent's meteorite-hunter-friendliness: they returned with five new meteorites, including one that weighs 16.7 pounds (7.6 kg).

Maria Valdes, a research scientist at the Field Museum and the University of Chicago, estimates that of the roughly 45,000 meteorites retrieved from Antarctica over the past century, only about a hundred or so are this size or larger. "Size doesn't necessarily matter when it comes to meteorites, and even tiny micrometeorites can be incredibly scientifically valuable," says Valdes, "but of course, finding a big meteorite like this one is rare, and really exciting."

Valdes was one of four scientists on the mission, led by Vinciane Debaille of the Université Libre de Bruxelles (FNRS-ULB); the research team was rounded out by Maria Schönbächler (ETH-Zurich) and Ryoga Maeda (VUB-ULB). The researchers were the first to explore potential new meteorite sites mapped using satellite imagery by Veronica Tollenaar, a thesis student in glaciology at the ULB.

"Going on an adventure exploring unknown areas is exciting," says Debaille, "but we also had to deal with the fact that the reality on the ground is much more difficult than the beauty of satellite images." Despite timing their trip for Antarctica's summertime in late December, temperatures hovered around 14° F (-10° C). Valdes notes that some days during their trip, it was actually colder in Chicago than it was in Antarctica, but spending days riding snowmobiles and trekking through ice fields and then sleeping in a tent made the Antarctic weather feel more extreme.

The five meteorites recovered by the team will be analyzed at the Royal Belgian Institute of Natural Sciences; meanwhile, sediment potentially containing tiny micrometeorites was divided among the researchers for study at their institutions.

Valdes says she's eager to see what the analyses of the meteorites reveal, because "studying meteorites helps us better understand our place in the universe. The bigger a sample size we have of meteorites, the better we can understand our Solar System, and the better we can understand ourselves."

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Stars disappear before our eyes

A startling analysis from Globe at Night -- a citizen science program run by NSF's NOIRLab -- concludes that stars are disappearing from human sight at an astonishing rate. The study finds that, to human eyes, artificial lighting has dulled the night sky more rapidly than indicated by satellite measurements. The study published in the journal Science showcases the unique contributions that citizen scientists can make in essential fields of research.

From the glowing arc of the Milky Way to dozens of intricate constellations, the unaided human eye should be able to perceive several thousand stars on a clear, dark night. Unfortunately, growing light pollution has robbed about 30% of people around the globe and approximately 80% of people in the United States of the nightly view of their home galaxy. A new paper published in the journal Science concludes that the problem is getting rapidly worse.

New citizen-science-based research sheds alarming light on the problem of 'skyglow' -- the diffuse illumination of the night sky that is a form of light pollution. The data for this study came from crowd-sourced observations collected from around the world as part of Globe at Night, a program run by NSF's NOIRLab and developed by NRAO astronomer Connie Walker. The research reveals that skyglow is increasing more rapidly than shown in satellite measurements of Earth's surface brightness at night.

"At this rate of change, a child born in a location where 250 stars were visible would be able to see only abound100 by the time they turned 18," said Christopher Kyba, a researcher at the German Research Centre for Geosciences and lead author of the paper detailing these results.

Light pollution is a familiar problem that has many detrimental effects, not only on the practice of astronomy. It also has an impact on human health and wildlife, since it disrupts the cyclical transition from sunlight to starlight that biological systems have evolved alongside. Furthermore, the loss of visible stars is a poignant loss of human cultural heritage. Until relatively recently, humans throughout history had an impressive view of the starry night sky, and the effect of this nightly spectacle is evident in ancient cultures, from the myths it inspired to the structures that were built in alignment with celestial bodies.

Despite being a well-recognized issue, however, the changes in sky brightness over time are not well documented, particularly on a global scale.

Globe at Night has been gathering data on stellar visibility every year since 2006.* Anyone can submit observations through the Globe at Night web application on a desktop or smartphone. After entering the relevant date, time and location, participants are shown a number of star maps. They then record which one best matches what they can see in the sky without any telescopes or other instruments.

This gives an estimate of what is called the naked eye limiting magnitude, which is a measure of how bright an object must be in order to be seen. This can be used to estimate the brightness of skyglow, because as the sky brightens, the fainter objects disappear from sight.

The authors of the paper analyzed more than 50,000 observations submitted to Globe at Night between 2011 and 2022, ensuring consistency by omitting entries that were affected by factors including cloud cover and moonlight. They focused on data from Europe and North America, since these regions had a sufficient distribution of observations across the land area as well as throughout the decade studied. The paper notes that the sky is likely brightening more quickly in developing countries, where satellite observations indicate the prevalence of artificial lighting is growing at a higher rate.

After devising a new method to convert these observations into estimates of the change in skyglow, the authors found that the loss of visible stars reported by Globe at Night indicates an increase in sky brightness of 9.6% per year over the past decade. This is much greater than the roughly 2% per year global increase in surface brightness measured by satellites.

"This shows that existing satellites aren't sufficient to study how Earth's night is changing," said Kyba. "We've developed a way to 'translate' Globe at Night observations of star visibility made at different locations from year to year into continent-wide trends of sky brightness change. That shows that Globe at Night isn't just an interesting outreach activity, it's an essential measurement of one of Earth's environmental variables."

Existing satellites are not well suited to measuring skyglow as it appears to humans, because there are no current instruments monitoring the whole Earth that can detect wavelengths shorter than 500 nanometers, which corresponds to the color cyan, or greenish blue. Shorter wavelengths, however, contribute disproportionately to skyglow, because they scatter more effectively in the atmosphere. White LEDs, now increasingly commonly used in high-efficiency outdoor lighting, have a peak in emission between 400 and 500 nanometers.

"Since human eyes are more sensitive to these shorter wavelengths at nighttime, LED lights have a strong effect on our perception of sky brightness," said Kyba. "This could be one of the reasons behind the discrepancy between satellite measurements and the sky conditions reported by Globe at Night participants."

Beyond wavelength differences, space-based instruments do not measure light emitted horizontally very well, such as from illuminated signs or windows, but these sources are significant contributors to skyglow as seen from the ground. Crowd-sourced observations will therefore always be invaluable for investigating the direct human effects of sky brightness.

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Researchers uncover 92 fossil nests belonging to some of India's largest dinosaurs

The discovery of more than 250 fossilized eggs reveals intimate details about the lives of titanosaurs in the Indian subcontinent, according to a study published January 18, 2022 in the open-access journal PLOS ONE by Harsha Dhiman of the University of Delhi, New Delhi and colleagues.

The Lameta Formation, located in the Narmada Valley of central India, is well-known for fossils of dinosaur skeletons and eggs of the Late Cretaceous Period. Recent work in the area uncovered 92 nesting sites containing a total of 256 fossil eggs belonging to titanosaurs, which were among the largest dinosaurs to have ever lived. Detailed examination of these nests has allowed Dhiman and colleagues to make inferences about the life habits of these dinosaurs.

The authors identified six different egg-species (oospecies), suggesting a higher diversity of titanosaurs than is represented by skeletal remains from this region. Based on the layout of the nests, the team inferred that these dinosaurs buried their eggs in shallow pits like modern-day crocodiles. Certain pathologies found in the eggs, such as a rare case of an "egg-in-egg," indicate that titanosaur sauropods had a reproductive physiology that parallels that of birds and possibly laid their eggs in a sequential manner as seen in modern birds. The presence of many nests in the same area suggests these dinosaurs exhibited colonial nesting behavior like many modern birds. But the close spacing of the nests left little room for adult dinosaurs, supporting the idea that adults left the hatchlings (newborns) to fend for themselves.

Details of dinosaur reproductive habits can be difficult to determine. These fossil nests provide a wealth of data about some of the largest dinosaurs in history, and they come from a time shortly before the age of dinosaurs came to an end. The insights gleaned from this study contribute significantly to paleontologists' understanding of how dinosaurs lived and evolved.

Harsha Dhiman, lead author of the research, adds: "Our research has revealed the presence of an extensive hatchery of titanosaur sauropod dinosaurs in the study area and offers new insights into the conditions of nest preservation and reproductive strategies of titanosaur sauropod dinosaurs just before they went extinct."

Guntupalli V.R. Prasad, co-author and leader of the research team, adds: "Together with dinosaur nests from Jabalpur in the upper Narmada valley in the east and those from Balasinor in the west, the new nesting sites from Dhar District in Madhya Pradesh (Central India), covering an east-west stretch of about 1000 km, constitute one of the largest dinosaur hatcheries in the world."

From Science Daily

Light-based tech could inspire Moon navigation and next-gen farming

Super-thin chips made from lithium niobate are set to overtake silicon chips in light-based technologies, according to world-leading scientists in the field, with potential applications ranging from remote ripening-fruit detection on Earth to navigation on the Moon.

They say the artificial crystal offers the platform of choice for these technologies due to its superior performance and recent advances in manufacturing capabilities.

RMIT University's Distinguished Professor Arnan Mitchell and University of Adelaide's Dr Andy Boes led this team of global experts to review lithium niobate's capabilities and potential applications in the journal Science.

The international team, including scientists from Peking University in China and Harvard University in the United States, is working with industry to make navigation systems that are planned to help rovers drive on the Moon later this decade.

As it is impossible to use global positioning system (GPS) technology on the Moon, navigation systems in lunar rovers will need to use an alternative system, which is where the team's innovation comes in.

By detecting tiny changes in laser light, the lithium-niobate chip can be used to measure movement without needing external signals, according to Mitchell.

"This is not science fiction -- this artificial crystal is being used to develop a range of exciting applications. And competition to harness the potential of this versatile technology is heating up," said Mitchell, Director of the Integrated Photonics and Applications Centre.

He said while the lunar navigation device was in the early stages of development, the lithium niobate chip technology was "mature enough to be used in space applications."

"Our lithium niobate chip technology is also flexible enough to be rapidly adapted to almost any application that uses light," Mitchell said.

"We are focused on navigation now, but the same technology could also be used for linking internet on the Moon to the internet on Earth."

What is lithium niobate and how can it be used?

Lithium niobate is an artificial crystal that was first discovered in 1949 but is "back in vogue," according to Boes.

"Lithium niobate has new uses in the field of photonics -- the science and technology of light -- because unlike other materials it can generate and manipulate electro-magnetic waves across the full spectrum of light, from microwave to UV frequencies," he said.

"Silicon was the material of choice for electronic circuits, but its limitations have become increasingly apparent in photonics.

"Lithium niobate has come back into vogue because of its superior capabilities, and advances in manufacturing mean that it is now readily available as thin films on semiconductor wafers."

A layer of lithium niobate about 1,000 times thinner than a human hair is placed on a semiconductor wafer, Boes said.

"Photonic circuits are printed into the lithium niobate layer, which are tailored according to the chip's intended use. A fingernail-sized chip may contain hundreds of different circuits," he said.

How does the lunar navigation tech work?

The team is working with the Australian company Advanced Navigation to create optical gyroscopes, where laser light is launched in both clockwise and anticlockwise directions in a coil of fibre, Mitchell said.

"As the coil is moved the fibre is slightly shorter in one direction than the other, according to Albert Einstein's theory of relativity," he said.

"Our photonic chips are sensitive enough to measure this tiny difference and use it to determine how the coil is moving. If you can keep track of your movements, then you know where you are relative to where you started. This is called inertial navigation."

Potential applications closer to home

This technology can also be used to remotely detect the ripeness of fruit.

"Gas emitted by ripe fruit is absorbed by light in the mid-infrared part of the spectrum," Mitchell said.

"A drone hovering in an orchard would transmit light to another which would sense the degree to which the light is absorbed and when fruit is ready for harvesting.

"Our microchip technology is much smaller, cheaper and more accurate than current technology and can be used with very small drones that won't damage fruit trees."

Read more at Science Daily

Plague trackers: Researchers cover thousands of years in a quest to understand the elusive origins of the Black Death

Seeking to better understand more about the origins and movement of bubonic plague, in ancient and contemporary times, researchers at McMaster University, University of Sydney and the University of Melbourne, have completed a painstaking granular examination of hundreds of modern and ancient genome sequences, creating the largest analysis of its kind.

Despite massive advances in DNA technology and analysis, the origin, evolution and dissemination of the plague remain notoriously difficult to pinpoint.

The plague is responsible for the two largest and most deadly pandemics in human history. However, the ebb and flow of these, why some die out and others persist for years has confounded scientists.

In a paper published today in the journal Communications Biology, McMaster researchers use comprehensive data and analysis to chart what they can about the highly complex history of Y. pestis, the bacterium that causes plague.

The research features an analysis of more than 600 genome sequences from around the globe, spanning the plague's first emergence in humans 5,000 years ago, the plague of Justinian, the medieval Black Death and the current (or third) Pandemic, which began in the early 20th century.

"The plague was the largest pandemic and biggest mortality event in human history. When it emerged and from what host may shed light on where it came from, why it continually erupted over hundreds of years and died out in some locales but persisted in others. And ultimately, why it killed so many people," explains evolutionary geneticist Hendrik Poinar, director of McMaster's Ancient DNA Centre.

Poinar is a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster's Global Nexus for Pandemics & Biological Threats.

The team studied genomes from strains with a worldwide distribution and of different ages and determined that Y. pestis has an unstable molecular clock. This makes it particularly difficult to measure the rate at which mutations accumulate in its genome over time, which are then used to calculate dates of emergence.

Because Y. pestis evolves at a very slow pace, it is almost impossible to determine exactly where it originated.

Humans and rodents have carried the pathogen around the globe through travel and trade, allowing it to spread faster than its genome evolved. Genomic sequences found in Russia, Spain, England, Italy and Turkey, despite being separated by years are all identical, for example, creating enormous challenges to determining the route of transmission.

To address the problem, researchers developed a new method for distinguishing specific populations of Y. pestis, enabling them to identify and date five populations throughout history, including the most famous ancient pandemic lineages which they now estimate had emerged decades or even centuries before the pandemic was historically documented in Europe.

"You can't think of the plague as just a single bacterium," explains Poinar. "Context is hugely important, which is shown by our data and analysis."

To properly reconstruct pandemics of our past, present, and future, historical, ecological, environmental, social and cultural contexts are equally significant.

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Billions of celestial objects revealed in gargantuan survey of the Milky Way

Astronomers have released a gargantuan survey of the galactic plane of the Milky Way. The new dataset contains a staggering 3.32 billion celestial objects -- arguably the largest such catalog so far. The data for this unprecedented survey were taken with the Dark Energy Camera, built by the US Department of Energy, at the NSF's Cerro Tololo Inter-American Observatory in Chile, a Program of NOIRLab.

The Milky Way Galaxy contains hundreds of billions of stars, glimmering star-forming regions, and towering dark clouds of dust and gas. Imaging and cataloging these objects for study is a herculean task, but a newly released astronomical dataset known as the second data release of the Dark Energy Camera Plane Survey (DECaPS2) reveals a staggering number of these objects in unprecedented detail. The DECaPS2 survey, which took two years to complete and produced more than 10 terabytes of data from 21,400 individual exposures, identified approximately 3.32 billion objects -- arguably the largest such catalog compiled to date. Astronomers and the public can explore the dataset here.

This unprecedented collection was captured by the Dark Energy Camera (DECam) instrument on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO), a Program of NSF's NOIRLab. CTIO is a constellation of international astronomical telescopes perched atop Cerro Tololo in Chile at an altitude of 2200 meters (7200 feet). CTIO's lofty vantage point gives astronomers an unrivaled view of the southern celestial hemisphere, which allowed DECam to capture the southern Galactic plane in such detail.

DECaPS2 is a survey of the plane of the Milky Way as seen from the southern sky taken at optical and near-infrared wavelengths. The first trove of data from DECaPS was released in 2017, and with the addition of the new data release, the survey now covers 6.5% of the night sky and spans a staggering 130 degrees in length. While it might sound modest, this equates to 13,000 times the angular area of the full Moon.

The DECaPS2 dataset is available to the entire scientific community and is hosted by NOIRLab's Astro Data Lab, which is part of the Community Science and Data Center. Interactive access to the imaging with panning/zooming inside of a web-browser is available from the Legacy Survey Viewer, the World Wide Telescope and Aladin.

Most of the stars and dust in the Milky Way are located in its disk -- the bright band stretching across this image -- in which the spiral arms lie. While this profusion of stars and dust makes for beautiful images, it also makes the Galactic plane challenging to observe. The dark tendrils of dust seen threading through this image absorb starlight and blot out fainter stars entirely, and the light from diffuse nebulae interferes with any attempts to measure the brightness of individual objects. Another challenge arises from the sheer number of stars, which can overlap in the image and make it difficult to disentangle individual stars from their neighbors.

Despite the challenges, astronomers delved into the Galactic plane to gain a better understanding of our Milky Way. By observing at near-infrared wavelengths, they were able to peer past much of the light-absorbing dust. The researchers also used an innovative data-processing approach, which allowed them to better predict the background behind each star. This helped to mitigate the effects of nebulae and crowded star fields on such large astronomical images, ensuring that the final catalog of processed data is more accurate.

"One of the main reasons for the success of DECaPS2 is that we simply pointed at a region with an extraordinarily high density of stars and were careful about identifying sources that appear nearly on top of each other," said Andrew Saydjari, a graduate student at Harvard University, researcher at the Center for Astrophysics | Harvard & Smithsonian and lead author of the paper. "Doing so allowed us to produce the largest such catalog ever from a single camera, in terms of the number of objects observed."

"When combined with images from Pan-STARRS 1, DECaPS2 completes a 360-degree panoramic view of the Milky Way's disk and additionally reaches much fainter stars," said Edward Schlafly, a researcher at the AURA-managed Space Telescope Science Institute and a co-author of the paper describing DECaPS2 published in the Astrophysical Journal Supplement. "With this new survey, we can map the three-dimensional structure of the Milky Way's stars and dust in unprecedented detail."

"Since my work on the Sloan Digital Sky Survey two decades ago, I have been looking for a way to make better measurements on top of complex backgrounds," said Douglas Finkbeiner, a professor at the Center for Astrophysics, co-author of the paper, and principal investigator behind the project. "This work has achieved that and more!"

"This is quite a technical feat. Imagine a group photo of over three billion people and every single individual is recognizable!" says Debra Fischer, division director of Astronomical Sciences at NSF. "Astronomers will be poring over this detailed portrait of more than three billion stars in the Milky Way for decades to come. This is a fantastic example of what partnerships across federal agencies can achieve."

Read more at Science Daily

Underlying assumptions of air quality need to be redefined

The 40-meter-high monitoring tower of the Innsbruck Atmospheric Observatory near the city center of Innsbruck in Austria, Europe, continuously provides data on the composition of the atmosphere near the surface. Every hour, 36,000 data points are recorded. Using a special measuring method -- the so-called eddy covariance method -- the concentration of air components can be continuously monitored. An international team led by Thomas Karl from the Department of Atmospheric and Cryospheric Sciences at the University of Innsbruck has now used these data to study the chemistry of ozone, nitrogen monoxide and nitrogen dioxide in urban areas in detail. The high proportion of diesel vehicles in European cities leads to strong concentrations of nitrogen monoxide. This reacts with ozone to produce nitrogen dioxide. In the atmosphere, nitrogen dioxide decomposes again to nitrogen monoxide and atomic oxygen, which immediately combines with atmospheric oxygen to form ozone.

Common assumptionneeds to be refined

This chemical cycle was described mathematically over 60 years ago in the first air pollution textbook by Philip Leighton. The relationship between the two processes has since been referred to as the Leighton ratio. Computer models of atmospheric chemistry use the Leighton ratio to minimize complexity by deriving the concentration of ozone, nitric oxide, and nitrogen dioxide from the concentration of each of the other two. In practice, this has been used, for example, to derive ozone concentrations in areas polluted by nitrogen oxides. The Innsbruck atmospheric researchers' data now show that in the presence of high nitrogen monoxide emissions, computational simplifications made by Leighton lead to incorrect results. Thomas Karl points out that "in cities with high nitrogen monoxide emissions, this ratio can be overestimated by up to 50 percent, which can lead to model calculations overestimating ground-level ozone concentrations in urban areas." The effect of chemistry -- turbulence interactions plays a significant role in the lowest layer of the atmosphere, up to 200 meters above the ground.

Responsible for the effect studied in Innsbruck is the combination of strong turbulence in urban areas in the presence of high nitrogen monoxide emissions. . The mixing of the gases combined with the relatively rapid chemical processes lead to more ozone being converted into nitrogen dioxide. The researchers' data also show that direct emissions of nitrogen dioxide from urban traffic are largely negligible in comparison to secondary formation. "It remains important to note that environmental regulations do not rely on model calculations but come into effect depending on actual measured pollutant concentrations," Thomas Karl emphasized.

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At least half of Africa's rhinos are now in private hands; New paths for rhino conservation are needed

African rhino numbers are declining at unsustainable rates in core state-run parks which is why more than half the continent's remaining rhinos are now on private land.

Until the past decade, the largest population of rhinos was found in South Africa's Kruger National Park. This state-run park has, however, lost 76% and 68% of its white and black rhinos over the past decade, respectively. By contrast, the number of white rhinos on private land has steadily increased over the same decade, particularly in South Africa.

Private rhino owners now conserve at least half of the continents' remaining rhinos, and communal lands conserve a growing proportion as well.

In a new article published in Frontiers in Ecology and the Environment, scientists from the University of Helsinki in Finland and the Universities of Stellenbosch and Nelson Mandela in South Africa have compiled publicly available rhino population data for African countries where rhinos occur, disaggregated by state, private, and communal land types where possible. They consider the implications of an emerging shift in rhino conservation from state to private and communal lands, and chart a new path for rhino conservation.

"Private and communal landowners in several southern and East African countries can generate revenues from wildlife tourism, trophy hunting and trade in live animals, making it financially viable to use their land to conserve wildlife rather than for farming livestock" explains paper author Dr Hayley Clements. "The result has been that hundreds of landowners conserve rhinos on their properties."

But the cost-benefit ratio of conserving rhinos is changing, explains study co-author Dr Dave Balfour. "Accelerating poaching has meant private rhino owners now spend on average US$150,000 per year on security measures. This is far more than state parks are able to spend per rhino or per unit area conserved. Combined with the generally smaller size of private rhino populations (averaging 100 km2), which likely makes them easier to protect than in places like Kruger (20,000 km2), this spending on security means private rhino populations have suffered lower poaching rates than in some core state-run parks. But these rising security costs mean many landowners are not willing or able to continue conserving rhinos, with some choosing to sell their rhinos, often at a loss."

"It is important that future policy enables new incentives that compensate for rising security costs, encouraging rhino conservation on private and communal land," explains senior author Prof. Enrico Di Minin. "For example, could landowners that conserve rhinos in extensive systems qualify for a more favourable tax structure? Could they be eligible for carbon or the emerging biodiversity credits or rhino bonds, given the role of rhinos in carbon cycling? Could they receive certifications for extensive management that increase the value of their wildlife-based tourism and hunting offerings? These are crucial questions that need to be addressed in order to support more sustainable conservation strategies for rhinos," he continues.

"If additional incentives are not enabled, we risk losing private and communal rhino custodians, and with them, half of the remaining African rhinos" concludes Dr Clements.

Read more at Science Daily