. Scientific Frontline

Monday, August 1, 2022

Scientists reveal distribution of dark matter around galaxies 12 billion years ago–further back in time than ever before

 The radiation residue from the Big Bang, distorted by dark matter 12 billion years ago.
Credit: Reiko Matsushita

A collaboration led by scientists at Nagoya University in Japan has investigated the nature of dark matter surrounding galaxies seen as they were 12 billion years ago, billions of years further back in time than ever before. Their findings, published in Physical Review Letters, offer the tantalizing possibility that the fundamental rules of cosmology may differ when examining the early history of our universe.

Seeing something that happened such a long time ago is difficult. Because of the finite speed of light, we see distant galaxies not as they are today, but as they were billions of years ago. But even more challenging is observing dark matter, which does not emit light.

Consider a distant source galaxy, even further away than the galaxy whose dark matter one wants to investigate. The gravitational pull of the foreground galaxy, including its dark matter, distorts the surrounding space and time, as predicted by Einstein’s theory of general relativity. As the light from the source galaxy travels through this distortion, it bends, changing the apparent shape of the galaxy. The greater the amount of dark matter, the greater the distortion. Thus, scientists can measure the amount of dark matter around the foreground galaxy (the “lens” galaxy) from the distortion.

However, beyond a certain point scientists encounter a problem. The galaxies in the deepest reaches of the universe are incredibly faint. As a result, the further away from Earth we look, the less effective this technique becomes. The lensing distortion is subtle and difficult to detect in most cases, so many background galaxies are necessary to detect the signal.

New Mexico Mammoths Among Best Evidence for Early Humans in North America

Close up of the bone pile during excavation. This random mix of ribs, broken cranial bones, a molar, bone fragments, and stone cobbles is a refuse pile from the butchered mammoths. It was preserved beneath the adult mammoth’s skull and tusks.
Credit: Timothy Rowe / The University of Texas at Austin.

About 37,000 years ago, a mother mammoth and her calf met their end at the hands of human beings.

Bones from the butchering site record how humans shaped pieces of their long bones into disposable blades to break down their carcasses, and rendered their fat over a fire. But a key detail sets this site apart from others from this era. It’s in New Mexico – a place where most archaeological evidence does not place humans until tens of thousands of years later.

A recent study led by scientists with The University of Texas at Austin finds that the site offers some of the most conclusive evidence for humans settling in North America much earlier than conventionally thought.

The researchers revealed a wealth of evidence rarely found in one place. It includes fossils with blunt-force fractures, bone flake knives with worn edges, and signs of controlled fire. And thanks to carbon dating analysis on collagen extracted from the mammoth bones, the site also comes with a settled age of 36,250 to 38,900 years old, making it among the oldest known sites left behind by ancient humans in North America.

“What we’ve got is amazing,” said lead author Timothy Rowe, a paleontologist and a professor in the UT Jackson School of Geosciences. “It’s not a charismatic site with a beautiful skeleton laid out on its side. It’s all busted up. But that’s what the story is.”

NIST Researchers Develop Miniature Lens for Trapping Atoms

Graphical illustration of light focusing using a planar glass surface studded with millions of nanopillars (referred to as a metalens) forming an optical tweezer. (A) Device cross section depicts plane waves of light that come to a focus through secondary wavelets generated by nanopillars of varying size. (B) The same metalens is used to trap and image single rubidium atoms.
Credit: Sean Kelley/NIST

Atoms are notoriously difficult to control. They zigzag like fireflies, tunnel out of the strongest containers and jitter even at temperatures near absolute zero.

Nonetheless, scientists need to trap and manipulate single atoms in order for quantum devices, such as atomic clocks or quantum computers, to operate properly. If individual atoms can be corralled and controlled in large arrays, they can serve as quantum bits, or qubits — tiny discrete units of information whose state or orientation may eventually be used to carry out calculations at speeds far greater than the fastest supercomputer.

Researchers at the National Institute of Standards and Technology (NIST), together with collaborators from JILA — a joint institute of the University of Colorado and NIST in Boulder — have for the first time demonstrated that they can trap single atoms using a novel miniaturized version of “optical tweezers” — a system that grabs atoms using a laser beam as chopsticks.

Ordinarily, optical tweezers, which garnered the 2018 Nobel Prize in Physics, feature bulky centimeter-size lenses or microscope objectives outside the vacuum holding individual atoms. NIST and JILA have previously used the technique with great success to create an atomic clock.

In the new design, instead of typical lenses, the NIST team used unconventional optics — a square glass wafer about 4 millimeters in length imprinted with millions of pillars only a few hundreds of nanometers (billionths of a meter) in height that collectively act as tiny lenses. These imprinted surfaces, dubbed metasurfaces, focus laser light to trap, manipulate and image individual atoms within a vapor. The metasurfaces can operate in the vacuum where the cloud of trapped atoms is located, unlike ordinary optical tweezers.

Triazavirin to Be Tested for Effectiveness Against Tick-Borne Encephalitis

Triazavirin was developed by scientists of the Ural Federal University and the Ural Branch of the Russian Academy of Sciences.
Credit: UrFU Press Service

The scientific community has provided research recommendations

The Medsintez plant, the manufacturer of the antiviral drug Triazavirin, plans to conduct studies of the drug for effectiveness against tick-borne encephalitis. Aleksandr Petrov, Chairman of the Board of Directors of the Medsintez Plant LLC, notes that the company has already received recommendations from the scientific community. This was reported by TASS.

"The effectiveness of Triazavirin against tick-borne encephalitis is a very interesting topic to study. Scientists are already saying that the drug can be effective against this virus. Currently we are guided by the opinion of scientists, that is why we are considering the possibility of conducting such studies," said Petrov.

He stressed that this year in some regions there is a high activity of ticks and increased detection of cases of encephalitis, that is why Triazavirin research in this area is relevant.

Reference:
Medsintez plant is located in Novouralsk (Sverdlovsk region). It specializes in the production of pharmaceutical products. The plant produces infusion solutions, ready forms of genetically engineered human insulin, solid and liquid forms of drugs. The plant manufactures licensed products and is engaged in the creation of new drugs.

Source/Credit: Ural Federal University

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Black cardamom effective against lung cancer cells

NUS researchers embarked on a scientific study of black cardamom, a spice used in Indian Ayurvedic medicine, as a source of potent bioactive compounds that are effective against lung cancer cells. Source: National University of Singapore

The main challenges associated with existing lung cancer drugs are severe side effects and drug resistance. There is hence a constant need to explore new molecules for improving the survival rate and quality of life of lung cancer patients.

In Indian Ayurvedic medicine, black cardamom has been used in formulations to treat cancer and lung conditions. A team of researchers from the NUS Faculty of Science, NUS Yong Loo Lin School of Medicine, and NUS College of Design and Engineering studied the scientific basis behind this traditional medicinal practice and provided evidence of the cytotoxic effect of black cardamom on lung cancer cells. The research highlighted the spice as a source of potent bioactives, such as cardamonin and alpinetin, which could be used in the treatment or prevention of lung cancer. The study is the first to report the association of black cardamom extract with oxidative stress induction in lung cancer cells, and compare the spice’s effects on lung, breast and liver cancer cells.

The findings could potentially lead to the discovery of safe and effective new bioactives which can prevent or cure cancer formation. The research was first published in the Journal of Ethnopharmacology.

Saturday, July 30, 2022

Analyzing sediments to investigate global warming occurring 56 million years ago

Aitor Payros
Credit: Unai Zorriketa. UPV/EHU

The Department of Geology of the UPV/EHU has examined sediments dating back 56 million years in the Tremp-Graus basin (on the border between Lleida and Huesca). It can be deduced from the study that the global warming episode at that time consisted of three phases in which the distribution of precipitation was different. The data from the study can be used to adjust mathematical models used to predict the effects of current climate change.

Major carbon emissions into the atmosphere and oceans took place 56 million years ago; that led to intense global warming known as the Paleocene-Eocene Thermal Maximum, and is regarded as an ancient analogue of today's anthropogenic warming. “Although the origin or cause of the warming at that time was different, the process was very similar to today’s warming, so it is considered to be similar to today's global warming. The climate is known to have warmed, but other alterations besides warming may occur with climate change. In particular, we wanted to analyze how the hydro-climatic conditions in terms of rainfall changed at that time,” said Aitor Payros, who gained a PhD in Geology at the UPV/EHU.

The UPV/EHU’s Department of Geology has investigated the mid-latitude alluvial and hydro-climatic changes recorded in the Tremp-Graus basin (on the border between Lleida and Huesca) during the Paleocene-Eocene Thermal Maximum, and has concluded that what happened then could in some way be similar to what is already happening today in the southeast of the Iberian Peninsula. To do this, they collected historical data from the region, and discovered geographical as well as hydro-climatic similarities.

Friday, July 29, 2022

Orchid helps insect get a grip

Figure 1: The white egret orchid (Habenaria radiata) resembles a dancing white egret.
Credit: Suetsugu Kenji / Kobe University

The wild orchid Habenaria radiata’s pure white petals resemble a white egret in flight (hence its common name white egret orchid). H. radiata has been loved by people since ancient times but the adaptive significance of the flower’s characteristic jagged shape has been unclear until now. A multi-institutional research group has been working for three years to solve this mystery by conducting field experiments in which the feather-like fringe was removed, and detailed behavioral observations of the orchid’s pollinators.

The research collaboration consisted of Associate Professor Suetsugu Kenji and student Abe Yusuke (who completed his Master’s degree in the 2021 academic year) of Kobe University Graduate School of Science, Asai Takeshi and Matsumoto Shuji of Himeji Tegarayama Botanical Garden, and Hasegawa Masahiro of Osaka Museum of Natural History.

From the results, they discovered that in their natural habitat, white egret orchids with the fringe removed produced fewer healthy seeds per individual fruit than intact plants. Hawkmoths, which are major pollinators of this orchid, normally grasp onto the fringe with their mid-legs to steady themselves when they drink its nectar, however the researchers observed that the hawkmoth was often unable to do this on plants with the fringe removed. In other words, this fringe functions as a supportive platform for the pollen-carrying hawkmoth. It was previously thought that hawkmoths mainly hover while drinking nectar.

Although the white egret orchid utilizes hawkmoths to transport its pollen, these important findings indicate that the eye-catching fringe is more than a visual aid for pollinators, and has evolved to support the hawkmoth while it feeds on the nectar.

These research results were published online in the international journal Ecology.

New Optical Switch Could Lead to Ultrafast All-Optical Signal Processing

An artist's illustration of an optical switch, splitting
 light pulses based on their energies.
Credit: Y. Wang, N. Thu, and S. Zhou
Engineers at Caltech have developed a switch—one of the most fundamental components of computing—using optical, rather than electronic, components. The development could aid efforts to achieve ultrafast all-optical signal processing and computing.

Optical devices have the capacity to transmit signals far faster than electrical devices by using pulses of light rather than electrical signals. That is why modern devices often employ optics to send data; for example, think of the fiberoptic cables that provide much faster internet speeds than conventional Ethernet cables.

The field of optics has the potential to revolutionize computing by doing more, at faster speeds, and with less power. However, one of the major limitations of optics-based systems at present is that, at a certain point, they still need to have electronics-based transistors to efficiently process the data.

Now, using the power of optical nonlinearity (more on that later), a team led by Alireza Marandi, assistant professor of electrical engineering and applied physics at Caltech, has created an all-optical switch. Such a switch could eventually enable data processing using photons. The research was published in the journal Nature Photonics on July 28.

Switches are among the simplest components of a computer. A signal comes into the switch and, depending on certain conditions, the switch either allows the signal to move forward or halts it. That on/off property is the foundation of logic gates and binary computation, and is what digital transistors were designed to accomplish. However, until this new work, achieving the same function with light has proved difficult. Unlike electrons in transistors, which can strongly affect each other's flow and thereby cause "switching," photons usually do not easily interact with each other.

Octopus lures from the Marianas are the oldest in the world

UOG archaeologist Michael Carson at the 2013 excavation of Sanhalom in Tinian, near the House of Taga. The excavation uncovered an octopus lure artifact from a layer that Carson has since carbon dated to 1500–1100 B.C., making it the oldest known artifact of its kind in the world.
Credit: MARC | University of Guam

A University of Guam archaeological study has determined that cowrie-shell artifacts found throughout the Marianas were lures used for hunting octopuses and that the devices, which have been found on islands across the Pacific, are the oldest known artifacts of their kind in the world.

The study used carbon dating of archaeological layers to confirm that lures found in Tinian and Saipan were from about 1500 B.C., or 3,500 years ago.

“That’s back to the time when people were first living in the Mariana Islands. So, we think these could be the oldest octopus lures in the entire Pacific region and, in fact, the oldest in the world,” said Michael T. Carson, an archaeologist with the Micronesian Area Research Center at UOG.

The study, titled “Let’s catch octopus for dinner: Ancient inventions of octopus lures in the Mariana Islands of the remote tropical Pacific,” is published in World Archaeology, a peer-reviewed academic journal. Carson, who holds a doctorate in anthropology, is the lead author of the study, assisted by Hsiao-chun Hung from The Australian National University in Canberra, Australia.

The fishing devices were made with cowrie shells, a type of sea snail and a favorite food of octopuses, that were connected by a fiber cord to a stone sinker and a hook.

They have been found in seven sites in the Mariana Islands. The oldest lures were excavated in 2011 from Sanhalom near the House of Taga in Tinian and in 2016 from Unai Bapot in Saipan. Other locations include Achugao in Saipan, Unai Chulu in Tinian, and Mochom at Mangilao Golf Course, Tarague Beach, and Ritidian Beach Cave in Guam.

Bumblebees Appear to Feel Pain

Bees were given the choice between either unheated or noxiously-heated (55°C) feeders with different sucrose concentrations and marked by different colors.
Credit Pippa Ager

New research by a team at Queen Mary University of London shows that bumblebees can modify their response to ‘noxious’ (painful) stimuli in a manner that is viewed in other animals as consistent with the ability to feel pain.

The researchers showed that bumblebees are capable of modifying their response to ‘noxious’ (painful) stimuli in order to get a higher sugar reward. The possibility of insect pain and suffering should therefore be taken seriously, they say.

Queen Mary’s Professor Lars Chittka, author of the new book The Mind of a Bee, who led the research, said “Insects used to be regarded as simple reflex automatons, responding to damaging stimuli only by withdrawal reflexes. Our new work shows that bees’ responses are more flexible and that they can suppress such reflexes when it suits them, for example if there is an extra-sweet treat to be had. Such flexibility is consistent with the capacity of a subjective experience of pain”

Study first-author Matilda Gibbons, PhD student at Queen Mary University of London said, “Scientists traditionally viewed insects as unfeeling robots, which avoid injury with simple reflexes. We've discovered bumblebees respond to harm non-reflexively, in ways that suggest they feel pain. If insects can feel pain, humans have an ethical obligation not to cause them unnecessary suffering. But the UK's animal welfare laws don't protect insects - our study shows that perhaps they should.”

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