Lifeboat Foundation

Astrophysicists have a cerium problem—models predict that certain stars should contain much less of this heavy element than astrophysical observations find. Recently performed experiments at CERN’s neutron time-of-flight (n_TOF) facility have widened the gap between theory and observations by 20% [1]. The researchers behind the work say that the results highlight the need for high-accuracy measurements of the nuclear properties of atoms, as well as for updated nucleosynthesis models of element formation. “Our experiment made the problem worse,” says Simone Amaducci of the INFN Laboratori Nationali del Sud, Italy. “That was unexpected, but it’s also interesting because it means there is something we don’t understand about how nucleosynthesis happens.”

Most of the Universe’s heavier elements form in stars via one of the so-called neutron-capture processes, in which an atomic nucleus absorbs one or more neutrons. In the slow neutron-capture process, or “s process,” the absorptions are spread out in time. As such, each absorption event results in either a stable nucleus with the same number of protons but one additional neutron or an unstable nucleus, which then radioactively decays to produce the nucleus of the next element in the periodic table—the one with one additional proton.

Using currently available models of the s process, researchers have correctly predicted the abundances of elements as heavy as barium (56 protons), lanthanum (57 protons), praseodymium (59 protons), and neodymium (60 protons) in stars that are known to be enriched via the s process. But the models appear to break down for cerium (58 protons), as the abundance predictions for this element in some low-mass, low-metallicity globular cluster stars have disagreed by up to 30% with observations. “This discrepancy is very strange, as the theory works for the neighboring elements,” says Sergio Cristallo, a team member who works on problems related to neutron capture at the National Institute of Astrophysics in Italy. “There is nothing in the models that should cause such a discrepancy just for one element.”

Scientists from China and Japan have identified unique features of the flow field in the lower mantle. Through their study of seismic anisotropy in the upper section of the lower mantle beneath the Philippine Sea Plate, they discovered that the ancient lower mantle flow field is still preserved there.

The study was published in Nature Geoscience.

The lower mantle is an important layer of the Earth and may play an important role in the evolution and material cycling of Earth’s interior. It is generally believed to be not only the final destination of subducted slabs, but also the birthplace of mantle plumes, which are two major styles in the evolution and material cycling of the Earth’s surface and interior. However, our knowledge of the characteristics of the flow field and geodynamics of the lower mantle is still deficient.

NASA ’s CubeSat Launch Initiative (CSLI) is sending four CubeSats to the International Space Station to advance space-based technologies in solar power, gamma-ray burst detection, and water monitoring. Developed in collaboration with universities and NASA, these satellites aim to enhance our understanding of cosmic phenomena and Earth’s environmental dynamics.

NASA’s CubeSat Launch Initiative is sending a group of four small satellites, called CubeSats, to the International Space Station (ISS) as ELaNa 51 (Educational Launch of Nanosatellites). These small payloads have been developed by NASA and universities and will be deployed from low Earth orbit.

Once circling Earth, the satellites will help demonstrate and mature technologies meant to improve solar power generation, detect gamma-ray bursts, determine crop water usage, and measure root-zone soil and snowpack moisture levels.

Researchers from the Broad Institute of MIT and Harvard, along with colleagues from Harvard Medical School and McLean Hospital, have identified remarkably consistent alterations in gene expression within the brains of individuals with schizophrenia and older adults. This discovery points to a shared biological foundation underlying the cognitive difficulties frequently observed in patients with schizophrenia and in aging populations.

In a study published in Nature, the team describes how they analyzed gene expression in more than a million individual cells from postmortem brain tissue from 191 people. They found that in individuals with schizophrenia and in older adults without schizophrenia, two brain cell types called astrocytes and neurons reduced their expression of genes that support the junctions between neurons called synapses, compared to healthy or younger people. They also discovered tightly synchronized gene expression changes in the two cell types: when neurons decreased the expression of certain genes related to synapses, astrocytes similarly changed expression of a distinct set of genes that support synapses.

The team called this coordinated set of changes the Synaptic Neuron and Astrocyte Program (SNAP). Even in healthy, young people, the expression of the SNAP genes always increased or decreased in a coordinated way in their neurons and astrocytes.

Study finds language-processing difficulties are an indicator — more so than memory loss — of amnestic mild cognitive impairment.

Individuals with mild cognitive impairment, especially of the “amnestic subtype” (aMCI), are at increased risk for dementia due to Alzheimer’s disease relative to cognitively healthy older adults. Now, a study co-authored by researchers from MIT, Cornell University, and Massachusetts General Hospital has identified a key deficit in people with aMCI, which relates to producing complex language.

This deficit is independent of the memory deficit that characterizes this group and may provide an additional “cognitive biomarker” to aid in early detection — the time when treatments, as they continue to be developed, are likely to be most effective.

In a novel experiment, physicists have observed long-range quantum coherence effects due to Aharonov-Bohm interference in a topological insulator-based device. This finding opens up a new realm of possibilities for the future development of topological quantum physics and engineering. This finding could also affect the development of spin-based electronics, which may potentially replace some current electronic systems for higher energy efficiency and may provide new platforms to explore quantum information science.

The research, published in Nature Physics, is the culmination of more than 15 years of work at Princeton. It came about when Princeton scientists developed a quantum device — called a bismuth bromide (α-Bi4Br4) topological insulator — only a few nanometers thick and used it to investigate quantum coherence.

Scientists have used topological insulators to demonstrate novel quantum effects for more than a decade. The Princeton team developed their bismuth-based insulator in a previous experiment where they demonstrated its effectiveness at room temperature. But this new experiment is the first time these effects have been observed with a very long-range quantum coherence and at a relatively high temperature. Inducing and observing coherent quantum states typically requires temperatures near absolute zero on artificially designed semiconducting materials only in the presence of strong magnetic fields.

Research unveils a mathematical model for ice nucleation, showing how surface angles affect water’s freezing point, with applications in snowmaking and cloud seeding.

From abstract-looking cloud formations to roars of snow machines on ski slopes, the transformation of liquid water into solid ice touches many facets of life. Water’s freezing point is generally accepted to be 32 degrees Fahrenheit. But that is due to ice nucleation — impurities in everyday water raise its freezing point to this temperature. Now, researchers unveil a theoretical model that shows how specific structural details on surfaces can influence water’s freezing point.

Continue reading “Freezing Point Phenomena: Unlocking the Strange Secrets of Ice Nucleation” »

In an article published in the Journal of Materials Chemistry C, Brazilian researchers describe a strategy to enhance the efficiency and stability of solar cells made of perovskite, a semiconductor material produced in the laboratory. The results of the project could be highly positive for the future of the solar power sector.

Developed by researchers at São Paulo State University (UNESP) in Bauru, Brazil, the method involves the use of a class of materials known as MXenes, a family of two-dimensional materials with a graphene-like structure combining transition metals, carbon and/or nitrogen, and surface functional groups such as fluoride, oxygen or hydroxyl. Their properties include high electrical conductivity, good thermal stability, and high transmittance (relating to the amount of light that passes through a substance without being reflected or absorbed).

Researchers have revolutionized quantum sensing with an algorithm that simplifies the assessment of Quantum Fisher Information, thereby enhancing the precision and utility of quantum sensors in capturing minute phenomena.

Quantum sensors help physicists understand the world better by measuring time passage, gravity fluctuations, and other effects at the tiniest scales. For example, one quantum sensor, the LIGO gravitational wave detector, uses quantum entanglement (or the interdependence of quantum states between particles) within a laser beam to detect distance changes in gravitational waves up to one thousand times smaller than the width of a proton!

LIGO isn’t the only quantum sensor harnessing the power of quantum entanglement. This is because entangled particles are generally more sensitive to specific parameters, giving more accurate measurements.