Preserving the stars: light pollution and what you can do about it

Astrophysicist Ms Kirsten Banks explains what we can do to reverse the impact of "light glow".
Photo Credit: UNSW Sydney.

An astrophysicist from UNSW Sydney explains why it’s so important that we can all look up and see the stars. 

Astronomer Carl Sagan famously said that there were more stars in the universe than grains of sand on earth.  

It has been estimated that there are over 100 billion stars in the Milky Way galaxy. While there is a limit to how many stars we can see from earth with the naked eye, that number is dramatically reducing due to light pollution. 

“We should be able to see around 2500 stars with the naked eye on any night, and we can see about 125 of them at best in Sydney,” says astrophysicist, proud Wiradjuri woman and UNSW PhD candidate Ms. Kirsten Banks.

In fact, in a recent study published in Science, data collected by citizen scientists around the world found light pollution is increasing at a rate that is equivalent to the brightness of the sky doubling every eight years.  

This latest research continues to expose the extent to which we’re losing the darkness of our night sky. Not being able to look up and see the stars will have significant cultural impacts, but there are steps we can all be taking to reduce the effect of light pollution.

Turtle and crocodile species with unique characteristics are more likely to go extinct

A Mugger Crocodile (Crocodylus palustris). In Pakistan, this species is still illegally hunted for its skin.
Image Credit: Bishnu Sarangi

New research led by the University of Oxford has revealed that the most endangered turtle and crocodile species are those that are most unique. Their loss could have widespread impacts on the ecosystems they live in since they carry out critical processes important for many other species. The results have been published in Nature Communications.

"When it comes to the conservation of turtles and crocodiles, we are dealing with a critical scenario. Furthermore, our actions are affecting unevenly more so those species that are characterized by unique life strategies. Once they are gone, these life strategies will be gone too, with no other species being able to provide a back-up." 

Professor Rob Salguero-Gómez, Department of Biology, University of Oxford

Turtles and crocodiles are two of the world's most endangered animal groups, with approximately half of the species globally threatened (International Union for Conservation of Nature, IUCN). Greater understanding of which species are most threatened and why is urgently needed to inform conservation efforts to save them.

In a new study led by researchers at the Department of Biology, University of Oxford, an international team examined the greatest risks to wild populations of turtles and crocodiles worldwide. The results demonstrate that the most endangered turtles and crocodile species are those that have evolved unique life strategies. These species typically carry out highly specific roles within their ecosystems that are unlikely to be taken up by other species if they disappear.

Separated at last

In the new method, laser pulses of different power (green) are combined in such a way that single excitation (blue), double excitation (red) and triple excitation (yellow) can be distinguished, for example, in biological light-harvesting complexes.
Illustration Credit: Julian Lüttig / Universität Würzburg

Scientists at the Universities of Würzburg and Ottawa have solved the decades-old problem of distinguishing between single and multiple light excitations. They present their new method in the journal Nature.

The construction of the first laser in 1960 ushered in commercial applications with light that have become an integral part of our everyday lives. At the same time, this development opened up the scientific field of laser spectroscopy – a technique that is central to the analysis of materials and the study of fundamental physical phenomena.

Despite all the successes, however, research teams have struggled since the 1970s with the problem that a laser shining on a sample can excite it not just once, but several times per experiment. In this case, the measurement results of the single excitation and the multiple excitations overlap and usually cannot be separated, making it difficult to understand the material.

Climate change threatens lemurs on Madagascar

A female grey mouse lemur (Microcebus murinus) carrying an infant.
Photo Credit: Manfred Eberle

They are small, have a high reproductive output and live in the forests of Madagascar. During the 5-month rainy season, offspring are born and a fat pad is created to survive the cool dry season when food is scarce. But what happens when the rainy season becomes drier and the dry season warmer? Can mouse lemurs adapt to climate change thanks to their high reproductive output? Researchers from the German Primate Center – Leibniz Institute for Primate Research, together with colleagues from the University of Zurich, have analyzed long-term data from Madagascar and found that climate change is destabilizing mouse lemur populations and increasing their risk of extinction. The fact that climate change is leading to greater fluctuations in population density and thus increases extinction risk in a fast-paced, ecological generalist is an alarming warning signal for potential biodiversity losses in the tropics.

Effects of climate change have mostly been studied in large, long-lived species with low reproductive output. Small mammals with high reproductive rates can usually adapt well to changing environmental conditions, so they have been studied little in the context of climate change. Claudia Fichtel and Peter Kappeler from the German Primate Center – Leibniz Institute for Primate Research (DPZ) have been researching lemurs on Madagascar for many years and have thus built up a unique data set to fill this knowledge gap.

Adipose tissue as a culprit: How obesity leads to diabetes

A high-fat diet leads to obesity and the development of diabetes.
Photo Credit: Muffin Creatives

A research team at the University of Basel has discovered that a high-fat diet alters the function of adipose tissue, thus impairing its ability to regulate blood sugar. This explains why a high-fat diet poses a significant health risk, particularly for diabetes.

Diabetes is a medical condition in which the body is unable to keep blood sugar in a healthy range. Normally, the pancreas produces sufficient insulin to regulate the blood sugar level and maintain homeostasis. However, in diabetics, the body has lost this ability, leading to hyperglycemia.

Blood sugar levels that are persistently too high can cause long-term damage to blood vessels and lead to severe complications such as blindness or kidney failure. It has been known for some time that obese patients are particularly at risk of developing type 2 diabetes and that adipose tissue plays a critical role in the onset of the disease. In their recent study, researchers led by Professor Michael N. Hall at the Biozentrum, University of Basel, revealed how a high-fat diet triggers diabetes.

Electricity from Air

Graphic illustration of titanium-air battery properties, in the style of the periodic table of elements
Illustration Credit: Courtesy of Technion – Israel Institute of Technology

Scientists at Forschungszentrum Jülich have developed and successfully lab-tested a novel titanium-air battery in cooperation with researchers at the Technion – Israel Institute of Technology in Haifa. This is the first time that experimental results of such a battery have been published, in which titanium is used as an active material. The metal is of interest as an electricity storage material because each atom can donate up to four electrons for charge transfer, while at the same time being relatively light and extremely resistant.

Scientific Results

Titanium is known as a passive, stable material. The researchers succeeded in utilizing its electrochemical potential for the storage of electrical energy by applying an ionic liquid called EMIm(HF)2.3F. Ionic liquids consist of salts with an atypical, very low melting point, which are used in a variety of applications due to their special electrical and material properties.

Early study shows cones in retinal degeneration, thought to be dormant, may retain visual function

“While the sensitivity of the cones was about 100-1000 fold less than normal, we were surprised to find that that the drop-off in sensitivity for the ganglion cells that project to the brain was much less,” said senior author Alapakkam Sampath.
Photo Credit: Miranda Scalabrino

New UCLA research in mice suggests that “dormant” cone photoreceptors in the degenerating retina are not dormant at all, but continue to function, producing responses to light and driving retinal activity for vision.  

The cells in the retina that produce the visual experience are rods and cones. Rods are active in dim light and cones in daylight. Mutations in rods that cause them to die trigger most inherited retinal degeneration. Cones can remain alive after nearly all the rods die, but they retract key parts of the cells and appear “dormant.”  

But while past literature suggested that dormant cells were not functional, and earlier attempts to record from them revealed no light-driven activity, the new study indicates for the first time that the cells are still viable. Furthermore, downstream signals recorded from the retina show that visual processing is not as compromised as may be expected. The authors say their findings demonstrate that therapeutic interventions to protect these cells, or enhance their sensitivity, have the capability to preserve nearly normal daytime vision. 

New Study Reveals Potential Link Between Two of Astronomy’s Most Mysterious Phenomena

Artist's conception of fast radio burst reaching Earth.
Illustration Credit: Jingchuan Yu, Beijing Planetarium

International team of scientists reports a possible correlation between gravitational waves from neutron star mergers and fast radio bursts; results could improve understanding of how some deep-space bursts occur.

The secrets of deep space may be starting to reveal themselves, as rapid advances in technology and stronger research collaborations are making it possible for astronomers to piece together cosmological clues like never before.

  In the March 27 issue of the journal Nature Astronomy, an international team of scientists shows for the first time a possible relationship between neutron star mergers and fast radio bursts (FRBs) – two of the most mysterious cosmological phenomena studied over the past two decades.

  The team, which includes researchers from UNLV, University of Western Australia (UWA), and Curtin University, reports on the observation of a deep space neutron star merger followed just 2 ½ hours later by an observed FRB. If confirmed, the correlation between the two events could unlock part of the mystery of how FRBs are generated.

  Fast radio bursts (FRBs) are millisecond-long pulses of electromagnetic radio waves that occur in deep space and produce the energy equivalent to the sun’s annual output. Most FRBs occur as one-off events, while others present as repeating bursts. Though their origins are still a bit of a mystery, the fraction of FRBs emitted as repeated bursts are likely produced by highly magnetized neutron stars known as magnetars.

Eco-efficient cement could pave the way to a greener future

Wei Meng (left) and Bing Deng are co-authors on the study. Deng holds a sample of cement made with coal fly ash purified through a flash Joule heating-based process.
Photo Credit: Gustavo Raskosky/Rice University

The road to a net-zero future must be paved with greener concrete, and Rice University scientists know how to make it.

The production of cement, an ingredient in concrete, accounts for roughly 8% of the world’s annual carbon dioxide emissions, making it a significant target of greenhouse gas emissions reduction goals. Toward those efforts, the Rice lab of chemist James Tour used flash Joule heating to remove toxic heavy metals from fly ash, a powdery byproduct of coal-based electric power plants that is used frequently in concrete mixtures. Using purified coal fly ash reduces the amount of cement needed and improves the concrete’s quality.

In the lab’s study, replacing 30% of the cement used to make a batch of concrete with purified coal fly ash improved the concrete’s strength and elasticity by 51% and 28%, respectively, while reducing greenhouse gas and heavy metal emissions by 30% and 41%, respectively, according to the paper published in the Nature journal Communications Engineering.

How football-shaped molecules occur in the universe

Graphic Credit: Shane Goettl/Ralf I. Kaiser

For a long time, it has been suspected that fullerene and its derivatives could form naturally in the universe. These are large carbon molecules shaped like a football, salad bowl or nanotube. An international team of researchers using the Swiss SLS synchrotron light source at PSI has shown how this reaction works. The results have just been published in the journal Nature Communications.

“We are stardust, we are golden. We are billion-year-old carbon.” In the song they performed at Woodstock, the US group Crosby, Stills, Nash & Young summarized what humans are essentially made of: star dust. Anyone with a little knowledge of astronomy can confirm the words of the cult American band – both the planets and we humans are actually made up of dust from burnt-out supernovae and carbon compounds billions of years old. The universe is a giant reactor and understanding these reactions means understanding the origins and development of the universe – and where humans come from.

In the past, the formation of fullerenes and their derivatives in the universe has been a puzzle. These carbon molecules, in the shape of a football, bowl or small tube, were first created in the laboratory in the 1980s. In 2010 the infrared space telescope Spitzer discovered the C60 molecules with the characteristic shape of a soccer ball, known as buckyballs, in the planetary nebula Tc 1. They are therefore the biggest molecules to have been discovered to date known to exist in the universe beyond our solar system.

HIV can persist for years in myeloid cells of people on antiretroviral therapy

HIV, the AIDS virus (yellow), infecting a human cell
Image Credit: National Cancer Institute

Scientific Frontline: "At a Glance" Summary: HIV Persistence in Myeloid Cells

• Main Discovery: HIV can persist for years in myeloid cells, specifically short-lived monocytes and longer-lived monocyte-derived macrophages, in individuals who have been virally suppressed on antiretroviral therapy.
• Methodology: Researchers isolated monocytes from the blood of virally suppressed participants and cultured them with antiretroviral drugs. After the monocytes differentiated into macrophages, an immune activating agent and fresh white blood cells were introduced to track viral reactivation and spread over a 12-day period using a novel quantitative method.
• Key Data: Detectable levels of HIV genetic material were found in the myeloid cells of 30 participants who had been on antiretroviral therapy for at least five years. Furthermore, cell cultures from 5 out of 10 participants demonstrated that the virus in these macrophages could reactivate, produce more virus, and infect new cells.
• Significance: The identification of myeloid cells as a long-lived and stable reservoir capable of viral rebound challenges the prevailing scientific consensus that monocytes are too short-lived to significantly impede HIV eradication efforts.
• Future Application: HIV cure strategies must be fundamentally broadened beyond their current scope to simultaneously target and eradicate viral reservoirs in both CD4 T cells and myeloid cells.
• Branch of Science: Virology and Microbiology
• Additional Detail: The study was led by researchers at the Johns Hopkins University School of Medicine, funded by the National Institutes of Health, and published in the journal Nature Microbiology.

With fewer salmon to eat, Southern Resident killer whales spend less time in the San Juan Islands

killer whales
Photo Credit: Michelle Klampe

As a key food supply declines, the endangered population of Southern Resident killer whales, known to frequent the Salish Sea off the coasts of Washington and British Columbia, is spending far less time in that region, a new study shows.

The Salish Sea around the San Juan Islands has traditionally been a hotspot for the whales. The Southern Residents would spend the summer months feeding on Chinook salmon, much of which belonged to the Fraser River stock that passes through the islands on its way to spawning grounds upriver.

But 17 years of whale sighting data shows that as the Fraser River Chinook salmon population dropped, the time spent by the Southern Residents around the San Juan Islands also declined ­– by more than 75%, said Joshua Stewart, an assistant professor with Oregon State University’s Marine Mammal Institute and the study’s lead author.

The findings were just published in the journal Marine Mammal Science. Co-authors of the paper are Jane Cogan, an independent researcher in Friday Harbor, Washington; John Durban, a professor with MMI who is also affiliated with the nonprofit SeaLife Response, Rehabilitation and Research (SR3); Holly Fearnback of SR3; David Ellifrit, Mark Malleson and Ken Balcomb of the nonprofit Center for Whale Research; and Melisa Pinnow of San Juan Orcas, a website dedicated to identification of individual orcas.

Components of Cytoskeleton Strengthen Effect of Sex Hormones

Super-high-resolution microscopic image of a cell that has been exposed to the sex hormone dihydrotestosterone. The androgen receptor (violet) and actin (green) are visible in the cell nucleus. Both molecules are stained with fluorescent dyes and thus made visible. The individual structures made visible (right) are only 200 nanometers (200 millionths of a millimeter) small.
Image Credit: Julian Knerr/University of Freiburg

Researchers from Freiburg and Kiel discover that actin acts in the cell nucleus and is partly responsible for the expression of male sexual characteristics

Steroid hormones, to which belong sex hormones like estrogen or testosterone, are important signaling molecules and are responsible among other things for controlling female and male phenotypic sex differentiation. They act by binding to receptor molecules that switch on and off the activity of hormone-dependent genes. Researchers at the University of Freiburg and Kiel University Hospital have discovered that components of the cytoskeleton are critically involved in this process. The findings are relevant for the diagnosis of medical conditions and the study of diseases and cancers in which steroid hormones play important roles. The study was published in the renowned journal Nature.

The new research findings show that filamentous actin, a component of the cytoskeleton, interacts with the androgen receptor directly in the cell nucleus and strengthens its effect. The androgen receptor mediates the signals of sex hormones for male sex development but also promotes the progression of prostate cancer.

Giant planet atmospheres vary widely, JWST confirms

 A ‘hot Jupiter’ called HD 149026b, is about 3 times hotter than the rocky surface of Venus, the hottest planet in our solar system.
Illustration Credit: NASA/JPL-Caltech

Gas giants orbiting our sun show a clear pattern; the more massive the planet, the lower the percentage of “heavy” elements (anything other than hydrogen and helium) in the planet’s atmosphere. But out in the Galaxy, the atmospheric compositions of giant planets do not fit the solar system trend, an international team of astronomers has found.

Using NASA’s James Webb Space Telescope (JWST), the researchers discovered that the atmosphere of exoplanet HD149026b, a ‘hot Jupiter’ orbiting a star comparable to our sun, is super-abundant in the heavier elements carbon and oxygen – far above what scientists would expect for a planet of its mass. In addition, the diagnostic carbon-to-oxygen ratio of HD149026b, also known as “Smertrios,” is elevated relative to our solar system.

A ‘hot Jupiter’ called HD 149026b, is about 3 times hotter than the rocky surface of Venus, the hottest planet in our solar system.

These findings, published in “High atmospheric metal enrichment for a Saturn-mass planet,” in Nature on [March 27] are an important first step toward obtaining similar measurements for a large sample of exoplanets in order to search for statistical trends, the researchers said. They also provide insight into planet formation.

Beaver Fossil Named After Buc-ee’s

Matthew Brown (left) and Steve May with beaver skulls new and old in the vertebrate paleontology collections at the Jackson School of Geosciences. Brown, the director of the collections, holds a skull from a modern North American Beaver. May, a research associate, holds a skull from Anchitheriomys buceei, a new species of ancient beaver that he discovered in the collections and named.
Photo Credit: UT Jackson School of Geosciences.

A new species of ancient beaver that was rediscovered by researchers in The University of Texas Austin’s fossil collections has been named after Buc-ee’s, a Texas-based chain of popular travel centers known for its cartoon beaver mascot.

The beaver is called Anchitheriomys buceei, or “A. buceei” for short.

Steve May, a research associate at the UT Jackson School of Geosciences, said that the beaver’s Texas connection and a chance encounter with a Buc-ee’s billboard are what inspired the name.

May is the lead author of the paper that describes A. buceei, along with another, much smaller, species of fossil beaver. Published in the journal Palaeontologia Electronica, the paper provides an overview of beaver occurrences along the Texas Gulf Coast from 15 million to 22 million years ago based on bones and archival records in the UT collections.

While driving down a highway in 2020, May spotted a Buc-ee’s billboard that said “This is Beaver Country.” The phrase brought to mind the Texas beaver fossils he had been studying at UT’s Texas Vertebrate Paleontology Collections.