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Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 5:20am

Ants adapt tool use to avoid drowning

Researchers have observed black imported fire ants using sand to draw liquid food out of containers, when faced with the risk of drowning. This is the first time this sophisticated tool use has been reported in animals.

Aiming Zhou et al, Ants adjust their tool use strategy in response to foraging risk, Functional Ecology (2020). DOI: 10.1111/1365-2435.13671

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Nanoscale machines convert light into work

Researchers have developed a tiny new machine that converts laser light into work. These optically powered machines self-assemble and could be used for nanoscale manipulation of tiny cargo for applications such as nanofluidics and particle sorting.

The work addresses a long-standing goal in the nanoscience community to create self-assembling nanoscale machines that can perform work in conventional environments such as room temperature liquids.

The machines are based on a type of matter known as optical matter in which metal nanoparticles are held together by light rather than the chemical bonds that hold together the atoms that make up typical matter.

Both the energy for assembling the machine and the power to make it work come from light. Once the laser light is introduced to a solution containing nanoparticles, the entire process occurs on its own. Although the user does not need to actively control or direct the outcome, this could readily be done to tailor the machines for various applications.

In optical matter, a laser light field creates interactions between metal nanoparticles that are much smaller than the wavelength of light. These interactions cause the particles to self-assemble into ordered arrays. This is a similar principle to optical trapping, in which light is used to hold and manipulate particles, biological molecules and cells.

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In the new work, the researchers created an optical matter machine that operates much like a mechanical machine based on interlocking gears. In such machines, when one gear is turned, a smaller interlocking gear will spin in the opposite direction. The optical matter machine uses circularly polarized light from a laser to create a nanoparticle array that acts like the larger gear by spinning in the optical field. This "optical matter gear" converts the circularly polarized light into orbital, or angular, momentum that influences a nearby probe particle to orbit the nanoparticle array (the gear) in the opposite direction.

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In previous work, the researchers discovered that when optical matter is exposed to circularly polarized light, it rotates as a rigid body in the direction opposite the polarization rotation. In other words, when the incident light  rotates one way the optical matter array responds by spinning the other. This is a manifestation of "negative torque". The researchers speculated that a machine could be developed based on this new phenomenon.

John Parker et al, An Optical Matter Machine: Angular Momentum Conversion by Collective Modes in Optically Bound Nanoparticle Arrays, Optica (2020). DOI: 10.1364/OPTICA.396147

https://phys.org/news/2020-10-nanoscale-machines.html?utm_source=nw...

Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 5:16am

**Duplications and inversions of DNA segments lead to the masculinization of female moles

Female moles are intersexual while retaining their fertility. Typical for mammals, they are equipped with two X chromosomes, but they simultaneously develop functional ovarian and testicular tissues. In female moles, both tissue types are united in one organ, the ovotestis—a feature unique among mammals.

The testicular tissue of the female mole does not produce sperm, but large amounts of the sex hormone testosterone, meaning the females have similarly high levels as the males. Presumably, this natural "doping" makes the female moles aggressive and muscular, an advantage for life underground, where they have to dig burrows and fight for resources.

Scientists are now reporting on the genetic peculiarities that lead to this characteristic sexual development in moles. According to the study, it is primarily changes in the structure of the genome that lead to altered control of genetic activity. In addition to the genetic program for testicular development, this also stimulates enzymes for male hormone production in the females.

the researchers have completely sequenced the genome of the Iberian mole (Talpa occidentalis) for the first time. Moreover, they examined the three-dimensional structure of the genome within the cell. In the nucleus, genes and their associated control sequences form regulatory domains—relatively isolated "neighborhoods" consisting of large regions where DNA sections interact frequently with each other.

In the course of the moles' evolution, then not only would individual letters of the DNA have changed, also larger pieces of the genome would have shifted.

If segments of DNA move from one location to another, completely new or reorganized regulatory domains can emerge and thus activate new genes and enhance or attenuate their expression.

When comparing the genome to that of other animals and humans, the team discovered an inversion—i.e., an inverted genomic segment—in a region known to be involved in testicular development. The inversion causes additional DNA segments to get included in the regulatory domain of the gene FGF9, which reorganizes the control and regulation of the gene. "This change is associated with the development of testicular tissue in addition to ovarian tissue in female moles.

The team also discovered a triplication of a genomic region responsible for the production of male sex hormones (androgens), more specifically the androgen production gene CYP17A1. "The triplication appends additional regulatory sequences to the gene—which ultimately leads to an increased production of male sex hormones in the ovotestes of female moles, especially more testosterone

 DOI: 10.1126/science.aaz2582 "The mole genome reveals regulatory rearrangements associated with adaptive intersexuality" Science (2020). science.sciencemag.org/cgi/doi … 1126/science.aaz2582

https://phys.org/news/2020-10-duplications-inversions-dna-segments-...

Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 5:10am

Generating photons for communication in a quantum computing system

Researchers using superconducting quantum bits connected to a microwave transmission line have shown how the qubits can generate on demand the photons, or particles of light, necessary for communication between quantum processors.

The advance is an important step toward achieving the interconnections that would allow a modular quantum computing system to perform operations at rates exponentially faster than classical computers can achieve.

 B. Kannan et al. Generating spatially entangled itinerant photons with waveguide quantum electrodynamics, Science Advances (2020). DOI: 10.1126/sciadv.abb8780

https://phys.org/news/2020-10-photons-quantum.html?utm_source=nwlet...

Comment by Dr. Krishna Kumari Challa on October 9, 2020 at 5:06am

New method can pinpoint cracks in metal long before they cause catastrophes

Fatigue failure plagues all metals and mitigating it is of great importance.

It is the leading cause of cracks in metallic components of aircraft.

That is why it is common practice in the airline industry to adhere to regular—and expensive—replacement schedules for many parts. But the life of those parts could be more accurately determined by better understanding the origins of crack initiation.

Whether it is the pounding of vehicles on bridges or shifts in air pressure on airplanes, such continuous change called "cyclic loading" gradually induces slips in the internal molecular structure of the most durable metals until cracks occur that could have been anticipated long before their perilous appearance.

With the lack of understanding of the mechanisms that lead to crack initiation, it has been difficult to predict with any reasonable accuracy the remaining life of a cyclically loaded material. The component could actually be fine and never fail but they throw it away anyway solely on the bases of statistical arguments. That's a huge waste of money.

Most current tests to understand the origins of crack initiation have focused on the moments just prior to or after cracking to assess what happened in the makeup of the metal. And many of those tests use far larger samples that preclude tracking the initiation of damage, which is a sub-micrometer scale feature. The new method narrows the lens as small as feasible and begins when metals are first exposed to loads that lead to localized damage that could become cracks.

 "The heterogeneity of persistent slip band nucleation and evolution in metals at the micrometer scale" Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abb2690

https://phys.org/news/2020-10-method-metal-catastrophes.html?utm_so...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:59am

Study Points to Novel Role for Microglia in Down Syndrome

Overactive immune cells identified in a mouse model and in postmortem human brain tissue may offer a potential therapeutic target for cognitive delays associated with the condition, researchers report.

Overactivation of the brain’s immune cells, called microglia, may play a role in cognitive impairments associated with Down syndrome.

Researchers in Italy identified elevated numbers of the cells in an inflammation-promoting state in the brains of mice with a murine version of the syndrome as well as in postmortem brain tissue from people with the condition. The team additionally showed that drugs that reduce the number of activated microglia in juvenile mice could boost the animals’ performance on cognitive tests.

https://www.cell.com/neuron/fulltext/S0896-6273(20)30710-8

https://www.the-scientist.com/news-opinion/study-points-to-novel-ro...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:36am

Neurobiology of conversation: Brain activity depends on who you're talking to

Our brains respond differently when talking to a person from a different socioeconomic group than during a conversation with someone of a similar background, a novel new imaging study shows.

While neuroscientists have used brain imaging scans to track in great detail neural responses of individuals to a host of factors such as stress, fear, addiction, and even love and lust, new research shows what happens in the brains of two individuals engaged in a simple social interaction.

The study reveals the distinct neurobiology of a conversation between two people of different backgrounds.

When a  professor talks to a homeless person, his or her frontal lobe activates a different neural network than if they were chatting with another colleague. Our brain has apparently designed a frontal lobe system that helps us deal with our diversity.

The researchers found that in both subjects the activity in the left dorsolateral prefrontal cortex, which is involved in control of cognitive processes, was much higher when they talked with someone from a different socioeconomic background than with someone of similar status.

There is a neurobiology of socialness, and neurobiology allows us to modulate our response to diversity.  We want to be inclusive, we want equity, and theoretically, neuroscience can say something about how we can achieve that.

https://news.yale.edu/2020/10/05/neurobiology-conversation-brain-ac...

https://researchnews.cc/news/2902/Neurobiology-of-conversation--Bra...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:30am

https://www.sciencealert.com/a-bacterial-clone-is-behind-a-concerni...

A Historical Epidemic Has Been Making a Scary Comeback Due to a Bacterial 'Clone'

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Brain Cells Turned to Glass Found in a Victim of The Vesuvius Eruption

Preserved brain cells have been found in the remains of a young man who died in the eruption of Mount Vesuvius in 79 CE. 

The brain cells' structure is still visible in a black, glassy material found in the man's skull. The new discovery of this structure, described on October 2 in the journal PLOS One, adds to the accumulating evidence that this glassy material is indeed part of the man's brain.

The transformation to glass occurred as a result of extreme heating and rapid cooling. 

The results of the study show that the vitrification process occurred at Herculaneum, unique of its kind, has frozen the neuronal structures of this victim, preserving them intact until today

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

https://www.sciencealert.com/brain-cells-turned-to-glass-have-been-...

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2,500 y/o mummy in "perfect condition" revealed after discovery of 59 sarcophagi

https://www.youtube.com/watch?v=7sd0BomMDDk&feature=emb_logo

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 7:16am

New research: nitrous oxide emissions 300 times more powerful than CO₂ are jeopardising Earth’s future

Nitrous oxide from agriculture and other sources is accumulating in the atmosphere so quickly it puts Earth on track for a dangerous 3℃ warming this century,  new research has found.

This colossal amount of nitrogen makes crops and pastures grow more abundantly. But it also releases nitrous oxide (N₂O), a greenhouse gas.

The study found that N₂O emissions from natural sources, such as soils and oceans, have not changed much in recent decades. But emissions from human sources have increased rapidly.

Agriculture caused almost 70% of global N₂O emissions in the decade to 2016. The emissions are created through microbial processes in soils. The use of nitrogen in synthetic fertilisers and manure is a key driver of this process.

Other human sources of N₂O include the chemical industry, waste water and the burning of fossil fuels.

https://theconversation.com/new-research-nitrous-oxide-emissions-30...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 6:44am

**Aerodynamicists reveal link between fish scales and aircraft drag

Reducing drag means faster aircraft speeds and less fuel consumption this is an important area of study for aerodynamicists

Through their biomimetic study, Professor Bruecker's team has discovered that the fish-scale array produces a zig-zag motion of fluid in overlapping regions of the surface of the fish, which in turn causes periodic velocity modulation and a streaky flow that can eliminate Tollmien-Schlichting wave induced transition to reduce skin friction drag by more than 25 percent.

An examination of oil flow visualization using computational fluid dynamics (CFD) on sea bass and common carp enabled the authors to come up with a working hypothesis:

"Computation Fluid Dynamics (CFD) was used to study the flow pattern over the surface and revealed a hitherto unknown effect of the scales as a mechanism to generate a regular pattern of parallel streamwise velocity streaks in the boundary layer. To prove their existence also on the real fish skin, oil flow visualization was done on sea bass and common carp, which indeed confirmed their presence in a regular manner along their real body, with the same arrangement relative to the scale array as observed along the biomimetic surface. These results let the authors hypothesize about a possible mechanism for transition delay, inspired by various previous fundamental transition studies, where streaky structures generated by cylindrical roughness elements or vortex generator arrays have shown a delay of transition."

Their surprising research outcome runs counter to the common belief that roughness promotes by-pass transition. Instead, the scales largely increase the stability of the base flow similar to an array of vortex generators.

A technical realization of such patterns on aerodynamic surfaces will pave the way towards the drastic reduction in fuel consumption and future zero-emission flight.

Muthukumar Muthuramalingam et al, Transition delay using biomimetic fish scale arrays, Scientific Reports (2020). DOI: 10.1038/s41598-020-71434-8

Muthukumar Muthuramalingam et al. Streak formation in flow over biomimetic fish scale arrays, The Journal of Experimental Biology (2019). DOI: 10.1242/jeb.205963

https://phys.org/news/2020-10-aerodynamicists-reveal-link-fish-scal...

Comment by Dr. Krishna Kumari Challa on October 8, 2020 at 6:36am

Aerodynamicists reveal link between fish scales and aircraft drag

Reducing drag means faster aircraft speeds and less fuel consumption this is an important area of study for aerodynamicists

Through their biomimetic study, Professor Bruecker's team has discovered that the fish-scale array produces a zig-zag motion of fluid in overlapping regions of the surface of the fish, which in turn causes periodic velocity modulation and a streaky flow that can eliminate Tollmien-Schlichting wave induced transition to reduce skin friction drag by more than 25 percent.

An examination of oil flow visualization using computational fluid dynamics (CFD) on sea bass and common carp enabled the authors to come up with a working hypothesis:

"Computation Fluid Dynamics (CFD) was used to study the flow pattern over the surface and revealed a hitherto unknown effect of the scales as a mechanism to generate a regular pattern of parallel streamwise velocity streaks in the boundary layer. To prove their existence also on the real fish skin, oil flow visualization was done on sea bass and common carp, which indeed confirmed their presence in a regular manner along their real body, with the same arrangement relative to the scale array as observed along the biomimetic surface. These results let the authors hypothesize about a possible mechanism for transition delay, inspired by various previous fundamental transition studies, where streaky structures generated by cylindrical roughness elements or vortex generator arrays have shown a delay of transition."

Their surprising research outcome runs counter to the common belief that roughness promotes by-pass transition. Instead, the scales largely increase the stability of the base flow similar to an array of vortex generators.

A technical realization of such patterns on aerodynamic surfaces will pave the way towards the drastic reduction in fuel consumption and future zero-emission flight.

Muthukumar Muthuramalingam et al, Transition delay using biomimetic fish scale arrays, Scientific Reports (2020). DOI: 10.1038/s41598-020-71434-8

Muthukumar Muthuramalingam et al. Streak formation in flow over biomimetic fish scale arrays, The Journal of Experimental Biology (2019). DOI: 10.1242/jeb.205963

https://phys.org/news/2020-10-aerodynamicists-reveal-link-fish-scal...

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