New Model Explains Precious Metals in Earth’s Mantle

Video Credit: Southwest Research Institute

Southwest Research Institute’s Dr. Simone Marchi collaborated on a new study finding the first geophysically plausible scenario to explain the abundance of certain precious metals — including gold and platinum — in the Earth’s mantle. Based on the simulations, or model, scientists found that impact-driven mixing of mantle materials scenario that could prevent the metals from completely sinking into the Earth’s core.

Early in its evolution, about 4.5 billion years ago, Earth sustained an impact with a Mars-sized planet, and the Moon formed from the resulting debris ejected into an Earth-orbiting disk. A long period of bombardment followed, the so-called “late accretion,” when planetesimals as large as our Moon impacted the Earth delivering materials including highly “siderophile” elements (HSEs) — metals with a strong affinity for iron — that were integrated into the young Earth.

“Previous simulations of impacts penetrating Earth’s mantle showed that only small fractions of a metallic core of planetesimals are available to be assimilated by Earth’s mantle, while most of these metals — including HSEs — quickly drain down to the Earth’s core,” said Marchi, who coauthored a Proceedings of the National Academy of Sciences (PNAS) paper outlining the new findings. “This brings us to the question: How did Earth get some of its precious metals? We developed new simulations to try to explain the metal and rock mix of materials in the present-day mantle.”

Space weather disrupts nocturnal bird migration

A Baltimore oriole in flight. Orioles are nocturnal migratory birds.
Photo Credit: Andrew Dreelin

It’s well-known that birds and other animals rely on Earth’s magnetic field for long-distance navigation during seasonal migrations.

But how do periodic disruptions of the planet’s magnetic field, caused by solar flares and other energetic outbursts, affect the reliability of those biological navigation systems?

University of Michigan researchers and their colleagues used massive, long-term datasets from networks of U.S. Doppler weather radar stations and ground-based magnetometers—devices that measure the intensity of local magnetic fields—to test for a possible link between geomagnetic disturbances and disruptions to nocturnal bird migration.

They found a 9%-17% reduction in the number of migrating birds, in both spring and fall, during severe space weather events. And the birds that chose to migrate during such events seemed to experience more difficulty navigating, especially under overcast conditions in autumn.

The new findings, published online Oct. 9 in Proceedings of the National Academy of Sciences, provide correlational evidence for previously unknown relationships between nocturnal bird migration dynamics and geomagnetic disturbances, according to the researchers.

Climate catastrophe produced instantaneous evolutionary change

A geocolor enhanced image captured by weather satellite GOES-16 shows Hurricane Harvey in the Gulf of Mexico as daylight approached Aug. 24, 2017, with nighttime features to the storm’s left and daytime features to its right.
Photo Credit: NOAA/NASA GOES Project

With species the world over on the move due to climate change, a unique experiment in the wake of 2017’s Hurricane Harvey has revealed a way that species can instantly evolve when they move in response to a climate catastrophe.

“With the profound and rapid changes, we’re seeing with the environment, movement is becoming critical for species’ survival,” said Rice University evolutionary biologist Scott Egan, senior author of a study published this week in Nature Ecology and Evolution. “The takeaway from this study is that while natural selection is still incredibly important, there’s another form of evolutionary change that’s directly related to movement, and it could make a huge difference in the evolution of organisms.”

Harvey, the most intense rainfall event in U.S. history, stalled over southeast Texas and dropped more than three feet of rain over thousands of square miles in a matter of days. Record flooding in and around Houston produced “mini extinctions” of insects and other species in areas that remained inundated for 10 or more days.

Boeing, Nammo Ramjet 155 Test Sets Distance Record

A Boeing and Nammo team set a record for longest indirect fire test of a ramjet-powered artillery projectile.
Photo Credit: U.S. Army photo

A Boeing and Nammo team set a record for longest indirect fire test of a ramjet-powered artillery projectile alongside officials from the U.S. Army — firing a Ramjet 155 munition from a 58-caliber Extended Range Cannon Artillery (ERCA) at Yuma Proving Ground, Ariz. The test advances development efforts for the Army’s top modernization priority, Long Range Precision Fires.

“Our objective was to demonstrate the ability to safely operate from the ERCA system and validate our performance. Both objectives were met.” said Gil Griffin, executive director of Boeing Phantom Works. “The team is working to deliver a superior, affordable precision strike weapon that can neutralize critical targets at long distances.”

The success follows last year’s Boeing-Nammo test recording the longest-ever indirect fire test of a Ramjet 155 munition. That test was completed using a 39-caliber towed artillery cannon at the Andøya Test Center in Norway.

Vacuum cleaner-effect in fungi can hold nanoplastics at bay

Photo Credit: Flockine

Using micro-engineered soil models, researchers at Lund University in Sweden have investigated the effect of tiny polystyrene particles on bacteria and fungi. While these nanoplastics reduced both bacterial and fungal growth, the fungus actually managed to "clean up" their surroundings, thereby easing the effect of the plastics.

“Plastic waste is a huge global problem. Whether carelessly discarded into nature, leaking from landfills or scoring from materials such as car tires and synthetic clothes – large amounts of micro- and nanoplastics end up in our soils,” says Micaela Mafla Endara, biology researcher at Lund University.

Nanoplastics have been proven to induce toxicity in diverse organisms, yet very little is known how this new pollutant is affecting the soil ecosystem. To study these nanoparticles of polystyrene, the researchers used microfluidic chips, a growth system that allowed them to observe interactions of single cells with the plastics under the microscope.

De­ci­pher­ing the in­tens­ity of past ocean cur­rents

In the 6x11 meter flume tank, an ar­ti­fi­cial con­tin­ental slope was re­cre­ated by hand. The cir­cu­lar photo shows first au­thor Hen­ri­ette Wil­ck­ens form­ing the slope from sed­i­ment. The wa­ter-filled tank can be seen in the back­ground.
Photo Mont­age Credit: MARUM – Cen­ter for Mar­ine En­vir­on­mental Sci­ences, Uni­versity of Bre­men, E. Mira­montes

Ocean cur­rents de­term­ine the struc­ture of the deep-sea ocean floor and the trans­port of sed­i­ments, or­ganic car­bon, nu­tri­ents and pol­lut­ants. In flume-tank ex­per­i­ments, re­search­ers from MARUM – Cen­ter for Mar­ine En­vir­on­mental Sci­ences at the Uni­versity of Bre­men have sim­u­lated how cur­rents shape the sea­floor and con­trol sed­i­ment de­pos­ition. This will help in re­con­struc­tions of past mar­ine con­di­tions. They have now pub­lished their res­ults in the Nature journal Communications Earth & Environment.

De­tails of past cli­mate con­di­tions are re­vealed to re­search­ers not only by sed­i­ment samples from the ocean floor, but also by the sur­face of the sea­floor, which is ex­posed to cur­rents that are con­stantly al­ter­ing it. De­pos­its shaped by near-bot­tom cur­rents are called con­tour­ites. These sed­i­ment de­pos­its con­tain in­form­a­tion about past ocean con­di­tions as well as clues to cli­mate. Con­tour­ites are of­ten found on con­tin­ental slopes or around deep-sea moun­tains. But they can be found in any en­vir­on­ment where strong cur­rents oc­cur near the sea­floor. The mech­an­isms that con­trol them are not yet well un­der­stood. Ex­per­i­ments in flume tanks will help to change this through the de­pic­tion of de­pos­ition in fu­ture mod­els.

Cancer research: Metabolite drives tumor development

Tumor organoids (green/blue) are used as a model to study the metabolic changes in liver cell cancer.
 Image Credit: Dr. Sandro Nuciforo, Department of Biomedicine, University of Basel

Cancer cells are chameleons. They completely change their metabolism to grow continuously. University of Basel scientists have discovered that high levels of the amino acid arginine drive metabolic reprogramming to promote tumor growth. This study suggests new avenues to improve liver cancer treatment.

The liver is a vital organ with many important functions in the body. It metabolizes nutrients, stores energy, regulates the blood sugar level and plays a crucial role in detoxifying and removing harmful components and drugs. Liver cancer is one of the world’s most lethal types of cancer. Conditions that cause liver cancer include obesity, excessive alcohol consumption and hepatitis C infection. Early diagnosis and appropriate therapeutic strategies are crucial for improving treatments in liver cancer.

Cancer as a metabolic disease

In the past decade, scientists have made much progress in understanding the multiple facets of cancer. Historically, it has long been viewed as a disorder in cell proliferation. However, there is growing evidence that cancer is a metabolic disease. In other words, cancer arises when cells rewire their metabolism to allow uncontrolled cell proliferation. How do cells change their metabolism and how does this change in turn lead to tumorigenicity? With their new study in “Cell”, researchers led by Professor Michael N. Hall at the Biozentrum, University of Basel, have discovered a key driver of metabolic rewiring in liver cancer cells.

Evolutionary history of three-finger snake toxins decoded

Burkhard Rost, a professor of bioinformatics
Photo Credit: Julia Eberle / ediundsepp / TUM

Snakebites cause around 100,000 deaths worldwide every year. Researchers at the Technical University of Munich (TUM) have investigated how the toxin emerged between 50 and 120 million years ago through the modification of a gene that also occurs in mammals and other reptiles. The results could help with the development of better snakebite treatments and lead to new knowledge for the treatment of illnesses such as type 2 diabetes and hypertension.

When venom passes into a snakebite victim, it binds onto receptors on nerve and muscle cells and interrupts communication pathways between them. This initially causes paralysis and, without an antidote, can cause death within a matter of minutes or hours. A team of researchers has studied how the protein structure of snake venoms known as three-finger toxins (3FTxs) has changed over the course of evolution.

Biodiversity in the forest: mixed forests are more productive if they are structurally complex

Photo Credit: Imat Bagja Gumilar

The more tree-rich forests are, the faster the trees grow and the more CO2 they can bind. A joint study by the TU Dresden, Leuphana University of Lüneburg, Martin Luther University Halle-Wittenberg (MLU), University of Leipzig, University of Montpellier and the German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig shows which mechanisms lie behind it. The results have now been published in the journal Science Advances.

If many different tree species live together in mixed stands, this has a positive effect on their growth and thus wood production - many studies have already confirmed this. The greater the variety of tree species in a forest, the more complex the structures are. The species not only grow to different extents in a certain period of time and have very different tree tops, they also have individual demands on light, water and nutrients. It was previously unclear how the structural complexity in mixed stocks is related to productivity and which mechanisms work here.

A mother mouse needs a diverse gut microbiome to form a healthy placenta

“More and more evidence is suggesting that [the gut microbiome] begins to exert its influence even during prenatal life,” said UCLA’s Elaine Hsiao.
Photo Credit: Karsten Paulick

The bacteria found naturally in the digestive tract does a lot more than help digest food.

Scientists have established that these microbial communities are also involved with the immune system and play a role in mental health. Now, they can add helping grow a healthy placenta during pregnancy to the list of unexpected ways the gut microbiome influences health and well-being.

New research led by UCLA scientists and published today in the journal Science Advances shows that mice with depleted gut microbiomes had smaller placentas than normal mice and that the network of blood vessels between the placenta and the fetus was also less developed.

Either of these conditions could deprive a fetus of nutrients, oxygen and other things it needs to grow. But when malnourished pregnant mice that had been fed low-protein diets and had diminished microbiomes were supplemented with short-chain fatty acids, which are produced by gut microbes, their placentas grew to normal size, the researchers said.

The new findings add to mounting evidence that in addition to its many other activities, the gut microbiome plays a role in the formation of new blood vessels, a process known as angiogenesis. They also show that byproducts of microbe metabolism known as metabolites play key roles in feto-placental development.