. Scientific Frontline

Tuesday, August 30, 2022

How Prehistoric Humans Simplified the World’s Food Webs

Illustration depicting all mammal species that would inhabit Southern California today if not for human-linked extinction. Extinct species appear in black and white.
Credit: Oscar Sanisidro/University of Alcalá

Research conducted with the help of a University at Albany anthropologist has revealed the cascading effects that humans have had on mammal declines and their food webs over the last 130,000 years, a new study in the journal Science shows.

The study, which was carried out by researchers in the United States, United Kingdom, Denmark and Spain, set out to determine the magnitude of food web loss among mammals since the Late Pleistocene, following the arrival and expansion of human populations around the world.

“We’ve known for a long time that as humans spread out of Africa, everywhere they went, waves of animal extinctions followed their arrival,” said John Rowan, an assistant professor of anthropology at UAlbany who co-authored the study. “When humans got to North America, there were saber-toothed cats, dire wolves, mammoths, mastodons and giant bears. But all these animals start to disappear soon after our species show up.”

While scientists were aware of the human link to mammal extinctions, little was understood regarding how those losses reverberated throughout food webs, which characterize how species interact with one another in an ecosystem. Extinction alone can impact the links in a food web, but so can reductions and shifts in geographic range due to human impacts, such as habitat destruction.

Scientists Grow Lead-Free Solar Material With a Built-In Switch

Light microscopy image of nanowires, 100 to 1,000 nanometers in diameter, grown from cesium germanium tribromide (CGB) on a mica substrate. The CGB nanowires are samples of a new lead-free halide perovskite solar material that is also ferroelectric.
Credit: Peidong Yang and Ye Zhang/Berkeley Lab

Solar panels, also known as photovoltaics, rely on semiconductor devices, or solar cells, to convert energy from the sun into electricity.

To generate electricity, solar cells need an electric field to separate positive charges from negative charges. To get this field, manufacturers typically dope the solar cell with chemicals so that one layer of the device bears a positive charge and another layer a negative charge. This multilayered design ensures that electrons flow from the negative side of a device to the positive side – a key factor in device stability and performance. But chemical doping and layered synthesis also add extra costly steps in solar cell manufacturing.

Now, a research team led by scientists at DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab), in collaboration with UC Berkeley, has demonstrated a unique workaround that offers a simpler approach to solar cell manufacturing: A crystalline solar material with a built-in electric field – a property enabled by what scientists call “ferroelectricity.” The material was reported earlier this year in the journal Science Advances.

Researchers produce nanodiamonds capable of delivering medicinal and cosmetic remedies through the skin

Nanodiamond applied on skin samples and penetrated through all skin layers: nanodiamond concentration reduces as the layer is deeper
Credit: Prof. Dror Fixler, Bar-Ilan University 

The skin is one of the largest and most accessible organs in the human body, but penetrating its deep layers for medicinal and cosmetic treatments still eludes science.

Although there are some remedies -- such as nicotine patches to stop smoking -- administered through the skin, this method of treatment is rare since the particles that penetrate must be no larger than 100 nanometers (one thousandth of a centimeter). Creating effective tools using such tiny particles is a great challenge. Because the particles are so small and difficult to see, it is equally challenging to determine their exact location inside the body – information necessary to ensure that they reach the intended target tissue. Today such information is obtained through invasive, often painful, biopsies.

A novel approach, developed by researchers at Bar-Ilan University in Israel, provides an innovative solution to overcoming both of these challenges. Combining techniques in nanotechnology and optics, they produced tiny (nanometric) diamond particles so small that they are capable of penetrating skin to deliver medicinal and cosmetic remedies. In addition, they created a safe, laser-based optical method that quantifies nanodiamond penetration into the various layers of the skin and determines their location and concentration within body tissue in a non-invasive manner – eliminating the need for a biopsy.

X-shaped radio galaxies might form more simply than expected


When astronomers use radio telescopes to gaze into the night sky, they typically see elliptical-shaped galaxies, with twin jets blasting from either side of their central supermassive black hole. But every once in a while, — less than 10% of the time — astronomers might spot something special and rare: An X-shaped radio galaxy, with four jets extending far into space.

Although these mysterious X-shaped radio galaxies have confounded astrophysicists for two decades, a new Northwestern University study sheds new insight into how they form — and its surprisingly simple. The study also found that X-shaped radio galaxies might be more common than previously thought.

The study was published in the Astrophysical Journal Letters. It marks the first large-scale galaxy accretion simulation that tracks the galactic gas far from the supermassive black hole all the way toward it.

Simple conditions lead to messy result

Using new simulations, the Northwestern astrophysicists implemented simple conditions to model the feeding of a supermassive black hole and the organic formation of its jets and accretion disk. When the researchers ran the simulation, the simple conditions organically and unexpectedly led to the formation of an X-shaped radio galaxy.

Dolphins form largest alliance network outside humans

Male trio with female.
Credit: Dr Simon Allen

Male bottlenose dolphins form the largest known multi-level alliance network outside humans, an international team led by researchers at the University of Bristol have shown. These cooperative relationships between groups increase male access to a contested resource.

The scientists, with colleagues from the University of Zurich and University of Massachusetts, analyzed association and consortship data to model the structure of alliances between 121 adult male Indo-Pacific bottlenose dolphins at Shark Bay in Western Australia. Their findings have been published in The Proceedings of the National Academy of Sciences (PNAS).

Male dolphins in Shark Bay form first-order alliances of two-three males to cooperatively pursue consortships with individual females. Second-order alliances of four-14 unrelated males compete with other alliances over access to female dolphins and third-order alliances occur between cooperating second-order alliances.

Co-lead author Dr Stephanie King, Associate Professor from Bristol’s School of Biological Sciences explained: “Cooperation between allies is widespread in human societies and one of the hallmarks of our success. Our capacity to build strategic, cooperative relationships at multiple social levels, such as trade or military alliances both nationally and internationally, was once thought unique to our species.

“Not only have we shown that male bottlenose dolphins form the largest known multilevel alliance network outside humans, but that cooperative relationships between groups, rather than simply alliance size, allows males to spend more time with females, thereby increasing their reproductive success.”

University Created Glass with Outstanding Radiation Protection Properties

Boron-based glass is one of the best known and highest quality systems.
Photo credit: Ilya Safarov

Physicists at Ural Federal University, together with colleagues from universities in Germany, Pakistan, and Egypt, have synthesized new glass with outstanding radiation protection properties. The glass can be used in such fields as nuclear medicine, astronaut spacesuits, and spacecraft production. An article about the research was published in the Journal of Inorganic and Organometallic Polymers and Materials.

A novel boro-bariofluoride sodium calcium nickel glasses were created using a conventional melt-hardening technique. By heating the composition to melting temperature and then abruptly cooling it to room temperature, the researchers obtained a homogeneous mixture of boron oxide, barium fluoride, calcium oxide, sodium oxide, and nickel oxide.

"Research of physical and optical properties of glasses synthesized in this way showed that as nickel oxide is added to the composition, all optical characteristics of the initial boro-bariofluoride and sodium-calcium glass samples obtained from it improve. The density of glasses increases, the absorption spectrum increases, shifting towards longer wavelengths of radiation, and the ability of the system to shield photons carrying electromagnetic radiation increases," explains Ali Abouhaswa, Senior Researcher of the Section of Solid State Magnetism at UrFU, a co-author of the article.

According to the scientist, the adding of nickel oxide makes the glass applicable to optoelectronic and photoelectric devices, such as gas sensors, UV-photosensors, photovoltaic cells, photocatalysts, and electrochromic devices.

Novel Coronaviruses Are Riskiest for Spillover

A wildlife surveillance team member samples a bumblee bat for viruses in Myanmar.
Credit: Smithsonian Conservation Biology Institute

In the past decade, scientists have described hundreds of novel viruses with the potential to pass between wildlife and humans. But how can they know which are riskiest for spillover and therefore which to prioritize for further surveillance in people?

Scientists from the University of California, Davis created network-based models to prioritize novel and known viruses for their risk of zoonotic transmission, which is when infectious diseases pass between animals and humans.

Their study, published in the journal Communications Biology, provides further evidence that coronaviruses are riskiest for spillover and should continue to be prioritized for enhanced surveillance and research.

The machine learning models were designed by the EpiCenter for Disease Dynamics at the UC Davis One Health Institute in the School of Veterinary Medicine.

Prioritizing novel viruses

The models found that novel viruses from the coronavirus family are expected to have a larger number of species as hosts. This is consistent with known viruses, indicating this family of viruses should be most highly prioritized for surveillance.

‘Long COVID’ effects on business and education

Wenlong Yuan is the Stu Clark Chair in Entrepreneurship and Innovation at UM
Credit: University of Manitoba

The pandemic has affected many aspects of our lives, from health consequences to collateral damage to restaurants and “mom and pop stores.” Supply chain problems have created panic shopping among consumers and many entertainment venues have seen the number of patrons decimate.

But what about large corporations such as Wal-Mart, BMO, or Exxon? What has COVID done to them?

Wenlong Yuan is the Stu Clark Chair in Entrepreneurship and Innovation at the UM Asper School of Business. His current research includes the implications of the COVID-19 pandemic for international business strategy and small and medium-sized enterprises (SMEs).

“Every kind of firm was affected by COVID,” he says, “so on the macro level we can see a very broad impact of the pandemic. Smaller businesses were hit worse than larger companies, mostly because they had fewer employees, and they couldn’t operate when even a few were sick. But nevertheless, larger businesses felt the effects too.”

Yuan says that previous to COVID, global markets were linked to one another and increases in one sector usually meant a parallel increase in another, like oil and tech stocks varying together.

But COVID created a situation where decoupling emerged, so that the economies of traditionally linked countries began doing their own thing.

Rat lungworm transmitted by many more species than slugs, snails

Flatworm in Hawaiʻi can act as a paratenic host of rat lungworm.
Photo credit: Shinji Sugiura CC4

While many people know that rat lungworm disease can be spread to humans by slugs and snails, new research shows those creatures are not the only ones that have been transmitting the illness.

Researchers from the University of Hawaiʻi at Mānoa and the University of London, UK, combed through nearly 140 scientific studies published between 1962–2022 and found 32 species of freshwater prawns/shrimp, crayfish, crabs, flatworms, fish, sea snakes, frogs, toads, lizards, centipedes, cattle, pigs and snails can act as carriers of the rat lungworm parasite (Angiostrongylus cantonensis). Of these, at least 13 species of prawns/shrimp, crabs, flatworms, fish, frogs, toads, lizards and centipedes have been associated with causing rat lungworm disease in humans.

Robert Cowie, senior author on the study and faculty member in UH Mānoa’s School of Ocean and Earth Science and Technology (SOEST), supervised Helena Turck, first author and graduate student at the University of London, UK, who did this study as her master’s degree thesis research, remotely during the pandemic. Professor Mark Fox of the Royal Veterinary College also collaborated on the study.

Cowie explained that the rat lungworm has a complex life cycle that involves slugs and snails as so-called “intermediate” hosts and rats as “definitive” hosts in which the worms reach maturity and reproduce. Rats become infected when they eat an infected snail or slug. People also become infected when they eat an infected snail or slug, and this can lead to serious illness and occasionally death.

Sensor-based early detection of age-related diseases from home

Exemplary apartment, highlighting the sensor system used in the study. Individual rooms are equipped with motion sensors, entrance and fridge doors are equipped with magnetic door sensors, and a bed sensor is placed beneath the mattress.
Credit: NeuroTec/Nature Scientific Reports, Creative Commons License

Researchers at the University of Bern and Inselspital, Bern University Hospital have demonstrated how sensors that record movement patterns could help detect health problems in the elderly, including old-age depression, risk of falls or cognitive impairment, at an early stage. In the future, this could help seniors to live a self-determined life at home for longer and relieve increasing pressure on the healthcare system.

Specific changes in our movement patterns can be indicators of several health problems: For instance, decrease in strength often correlates with risk of falls, mild cognitive impairment, depression, sleep problems, respiratory problems, cardiac arrhythmias and increasing myocardial weakness or worsening of a COVID-19 infection. In older individuals, systematic detection of such changes could help identify chronic diseases such as dementia, Parkinson's disease, or heart disease at an early stage. These age-related health problems are often discovered late, and their progression is usually difficult to assess objectively.

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