Giant spider provides promise of pain relief for irritable bowel syndrome

How your brain finds the good objects

How your brain finds the good objects

In the wild, it is essential for animals to pick out good or bad objects within their visual field. Whether it be food or predator, split-second recognition and action need to be made for survival.

https://researchnews.cc/news/2629/How-your-brain-finds-the-good-obj...

The underlying mechanisms that govern this behavior in the brain has been gradually uncovered by researchers. Nowscientists have revealed how the brain controls eye movements toward the 'good objects'.

---

Seismic data explains continental collision beneath Tibet

https://phys.org/news/2020-09-seismic-continental-collision-beneath...

Solstices and equinoxes are the products of Earth's axial tilt: the degree to which the planet is tilted relative to the Sun.

The axis around which the Earth spins isn't straight up and down - it's about 23.5 degrees off. Because of that, different parts of the Earth get exposed to more or less sunlight as the planet rotates around the Sun. That's why we have seasons.

It's also why the northern and Southern Hemisphere experience seasons at opposite times: During winter in the Northern Hemisphere, the Southern Hemisphere is tilted more towards the Sun, and vice versa.

Meanwhile, Earth is also constantly rotating, which keeps its heating even - kind of like a planet-sized rotisserie chicken twisting over a spit.

The axial tilt's most dramatic effect comes during the solstices, since those are the two days when one side of the planet is tilted the farthest away from the Sun and the other is the closest. On December 21, the Northern Hemisphere receives less than nine hours of daylight, while the Southern Hemisphere receives more than 15.

https://www.sciencealert.com/the-september-equinox-is-this-tuesday-...

Evolution of radio-resistance is very complicated 

The toughest organisms on Earth, called extremophiles, can survive extreme conditions like extreme dryness (desiccation), extreme cold, space vacuum, acid, or even high-level radiation. So far, the toughest of all seems to be the bacterium Deinococcus radiodurans—able to survive doses of radiation a thousand times greater than those fatal to humans. 

How this radio-resistance could have evolved in several organisms on our planet, naturally protected from solar radiation by its magnetic field? While some scientists suggest that radio-resistance in extremophile organisms could have evolved along with other kinds of resistance, such as resistance to desiccation, a question remained: which genes are specifically involved in radio-resistance?

To find out the researchers started with the naturally non-resistant bacteria, E. coli, and exposed it to iterative cycles of high-level irradiation. After many rounds of radiation exposure and outgrowth, a few radio-resistant populations emerged. Using whole-genome sequencing, the researchers studied the genetic alterations present in each radio-resistant population and determined which mutation provided radio-resistance to the bacteria.

The study of their genetic profile highlighted three mutations responsible for radio-resistance—all in genes linked to DNA repair mechanisms. The results show that the populations of radioresistant E. coli, continued to evolve and sub-populations emerged. Surprisingly, while radio-resistance induced by the first series of ionization could mainly be associated with three mutations, the second induced hundreds of mutations including large deletions and duplications of several genes. The four populations scienitsts are evolving in this new trial have now achieved levels of radio-resistance that are approaching the levels seen with Deinococcus radiodurans. As the current trial has progressed, the genomic alterations have proven to be much more complex than anticipated.

The researchers show that more cellular metabolisms are affected (ATP synthesis, iron-sulfur cluster biogenesis, cadaverine synthesis, and reactive oxygen species response). Furthermore, this study proves that radio-resistance can develop to the level of Deinococcus radiodurans, independently to desiccation-resistance. 

As the exposition to radiation and experimental evolution continues, more data are gathered on how to induce radio-resistance in bacteria. This could one day constitute a precious toolbox of mutations to engineer radioresistant probiotics helping for example patients treated with radiotherapy, or astronauts exposed to space radiation.

 Frontiers in Microbiology, DOI: 10.3389/fmicb.2020.582590 , www.frontiersin.org/articles/1 … 2020.582590/abstract

https://phys.org/news/2020-09-evolution-radio-resistance-complicate...

Scientists identify hormone that might help treat malabsorption

Scientists  used human intestinal organoids grown from stem cells to discover how our bodies control the absorption of nutrients from the food we eat. They further found that one hormone might be able to reverse a congenital disorder in babies who cannot adequately absorb nutrients and need intravenous feeding to survive.

Researchers found that the hormone peptide YY, also called PYY, can reverse congenital malabsorption in mice. With a single PYY injection per day, 80% of the mice survived. Normally, only 20% to 30% survive. This indicates PYY might be a possible therapeutic for people with severe malabsorption.

Poor absorption of macronutrients is a global health concern, underlying ailments such as malnutrition, intestinal infections and short-gut syndrome. So, identification of factors regulating nutrient absorption has significant therapeutic potential. Scientists reported that the absorption of nutrients—in particular, carbohydrates and proteins—is controlled by enteroendocrine cells  in the gastrointestinal tract.

Babies born without enteroendocrine cells —or whose enteroendocrine cells don't function properly—have severe malabsorption and require IV nutrition. This work could help them.

Enteroendocrine cells couple nutrient sensing to nutrient absorption by regulating ion transport," Nature Communications (2020). DOI: 10.1038/s41467-020-18536-z

https://medicalxpress.com/news/2020-09-scientists-hormone-malabsorp...

New drug candidate found for hand, foot and mouth disease

A study  offers some good news in the search for antiviral drugs for hard-to-treat diseases. Researchers have identified a potential new drug candidate against enterovirus 71, a common cause of hand, foot and mouth disease in infants and young children. While most people get better within 7 to 10 days after suffering little more than a fever and rash, severe cases can cause brain inflammation, paralysis and even death.

The compound of interest is a small molecule that binds to RNA, the virus's genetic material, and changes its 3-D shape in a way that stops the virus from multiplying without harming its human host.

"Small Molecule Targeting IRES Domain Inhibits Enterovirus 71 Replication via an Allosteric Mechanism that Stabilizes a Ternary Complex," Nature Communications (2020). DOI: 10.1038/s41467-020-18594-3

https://medicalxpress.com/news/2020-09-drug-candidate-foot-mouth-di...

New finding: Why some cancers may respond poorly to key drugs 

Patients with BRCA1/2 mutations are at higher risk for breast, ovarian and prostate cancers that can be aggressive when they develop—and, in many cases, resistant to lifesaving drugs. Now scientists  have identified a driver of the drug resistance that can make a life or death difference for patients with these cancers.

A major issue with cancer treatments is the development of resistance. When treatments stop working for patients, it's incredibly demoralizing and it's been a huge drive in research to understand these resistance mechanisms.

In a new paper published, researchers describe a protein that may help doctors predict which patients will become resistant to a class of drugs frequently used to treat BRCA 1/2-deficient tumours. The finding could help create more effective treatment plans for their patients.

The scientists identified that a protein called PCAF promotes DNA damage in BRCA 1/2-mutated cancer cells. Patients with low levels of this protein are likely to have poor outcomes and develop resistance to a type of drug that is used to treat BRCA-deficient tumors, called a PARP inhibitor.

PARP inhibitors are an important breakthrough in treating these aggressive cancers. What the researchers  found now 's that when levels of PCAF are low, it actually protects the cancer cells from this drug. By testing biopsy samples, doctors may be able to tell using PCAF as a molecular marker for PARP inhibitor responses what treatment may work best for a patient."

Fortunately, there is already another class of drugs on the market, called HDAC inhibitors, that can boost the effectiveness of the PCAF protein. HDAC inhibitors and PARP inhibitors have the potential to be prescribed as a combination therapy.

Molecular Cell (2020). DOI: 10.1016/j.molcel.2020.08.018

https://medicalxpress.com/news/2020-09-cancers-poorly-key-drugs.htm...

Without oxygen, Earth's early microbes relied on arsenic to sustain life

Much of life on planet Earth today relies on oxygen to exist, but before oxygen was present on our blue planet, lifeforms likely used arsenic instead. These findings are detailed in research published recently.

A key component of the oxygen cycle is where plants and some types of bacteria essentially take sunlight, water, and CO₂, and convert them to carbohydrates and oxygen, which are then cycled and used by other organisms that breathe oxygen. This oxygen serves as a vehicle for electrons, gaining and donating electrons as it powers through the metabolic processes. However, for half of the time life has existed on Earth, there was no oxygen present, and for the first 1.5 billion years.

Light-driven, photosynthetic organisms appear in the fossil record as layered carbonate rocks called stromatolites dating to around 3.7 billion years ago, says Visscher. Stromatolite mats are deposited over the eons by microbial ecosystems, with each layer holding clues about life at that time. There are contemporary examples of microbes that photosynthesize in the absence of oxygen using a variety of elements to complete the process, however it's unclear how this happened in the earliest life forms.

Theories as to how life's processes functioned in the absence of oxygen have mostly relied on hydrogen, sulfur, or iron as the elements that ferried electrons around to fulfill the metabolic needs of organisms. These theories were contested though.

Arsenic is another theoretical possibility, and evidence for that was found in 2008.The link with arsenic was strengthened in 2014 when researchers found evidence of arsenic-based photosynthesis in deep time.

 found a blood red river. The red sediments are made up by anoxogenic photosynthetic bacteria. The water is very high in arsenic as well. The water that flows over the mats contains hydrogen sulfide that is volcanic in origin and it flows very rapidly over these mats. There is absolutely no oxygen."

The team also showed that the mats were making carbonate deposits and creating a new generation of stromatolites. The carbonate materials also showed evidence for arsenic cycling—that arsenic is serving as a vehicle for electrons—proving that the microbes are actively metabolizing arsenic, much like oxygen in modern systems. Visscher says these findings, along with the fossil evidence, gives a strong sense of the early conditions of Earth.

Pieter T. Visscher et al. Modern arsenotrophic microbial mats provide an analog for life in the anoxic Archean, Communications Earth & Environment (2020). DOI: 10.1038/s43247-020-00025-2

https://phys.org/news/2020-09-oxygen-earth-early-microbes-arsenic.h...

An acoustically actuated microscopic device

Researchers  have developed remote-controlled, mechanical microdevices that, when inserted into human tissue, can manipulate the fluid that surrounds them, collect cells or release drugs. This breakthrough offers numerous potential applications in the biomedical field, from diagnostics to therapy.

Murat Kaynak, Pietro Dirix, and Mahmut Selman Sakar. “Addressable Acoustic Actuation of 3D Printed Soft Robotic Microsystems,” Advanced Science, 2020.

https://onlinelibrary.wiley.com/doi/10.1002/advs.202001120 

https://actu.epfl.ch/news/an-acoustically-actuated-microscopic-devi...

https://researchnews.cc/news/2649/An-acoustically-actuated-microsco...

SCI-COM: Scientists don’t share their findings for fun – they want their research to make a difference

Scientists don’t take time away from their research to share their expertise with journalists, policymakers and everyone else just to let us know about neat scientific facts. They share findings from their research because they want leaders and the public to use their hard-won insights to make evidence-based decisions about policy and personal issues. That’s according to two surveys of  researchers  conducted.

Scientists  reported “ensuring that policymakers use scientific evidence” is at the top of their list of communication goals. Helping their fellow citizens make better personal decisions also scores high. Further, scientists say they’re not communicating just to burnish their own reputation.

We know from other interviews and surveys that many scientists will often initially indicate that their communication “goal” is simply to increase knowledge or correct misinformation. However, if prodded by questions like “But why do you want to increase knowledge?” or “What do you hope will happen if you correct misinformation?” they will often identify their ultimate aim as helping people make better decisions.

Highly trained scientists seem especially willing to share what they’ve learned if they think it can help society make smarter choices. 

Scientists are more likely to say they’re willing to communicate, as well as to prioritize specific objectives or tactics, if they see a choice as ethical, able to make a difference and within their capacity.

https://theconversation.com/scientists-dont-share-their-findings-fo...

How The Brain Prepares For The Eyes To See Computer simulations show that spontaneous activity in the developing retina could help the visual cortex form properly prior to input from the eyes. Read more from Asian Scientist Magazine at: https://www.asianscientist.com/2020/09/in-the-lab/visual-cortex-spo...

--

3-D Printing inside the Body Could Patch Stomach Ulcers

In vivo bioprinting might also help repair hernias and treat infertility

--

The Quantum Butterfly Noneffect

A familiar concept from chaos theory turns out to work differently in the quantum world

--

** New analysis of black hole reveals a wobbling shadow

https://phys.org/news/2020-09-analysis-black-hole-reveals-shadow.ht...

--

Researchers pinpoint how iron deposits form

The findings shed new light on how iron deposits form—and this new understanding can aid geologists in the hunt for more ore.

https://phys.org/news/2020-09-iron-deposits.html?utm_source=nwlette...

--

Bushfires release decades of pollutants absorbed by forests

We know forests absorb carbon dioxide, but, like a sponge, they also soak up years of pollutants from human activity. When bushfires strike, these pollutants are re-released into the air with smoke and ash.

3-D bioprinting constructs for cartilage regeneration

Cartilage injury is a common cause of joint dysfunction and existing joint prostheses cannot remodel with host joint tissue. However, it is challenging to develop large-scale biomimetic anisotropic constructs that structurally mimic native cartilage.

 In  new reports, scientists detailed anisotropic cartilage regeneration using three-dimensional (3-D) bioprinting dual-factor releasing gradient-structured constructs. The team used the dual-growth-factor releasing mesenchymal stem cell (MSC)-laden hydrogels for chondrogenic differentiation (cartilage development). The 3-D bioprinted cartilage constructs showed whole-layer integrity, lubrication of superficial layers and nutrient supply into deeper layers. The scientists tested the cartilage tissue in the lab and in animal models to show tissue maturation and organization for translation to humans after sufficient experimental studies. The one-step, 3-D printed dual-factor releasing gradient-structured cartilage constructs can assist regeneration of MSC- and 3-D bioprinted therapy for injured or degenerative joints.

Ye Sun et al. 3D bioprinting dual-factor releasing and gradient-structured constructs ready to implant for anisotropic cartilage regeneration, Science Advances (2020). DOI: 10.1126/sciadv.aay1422

Chang H Lee et al. Regeneration of the articular surface of the rabbit synovial joint by cell homing: a proof of concept study, The Lancet (2010). DOI: 10.1016/S0140-6736(10)60668-X

April M Craft et al. Generation of articular chondrocytes from human pluripotent stem cells, Nature Biotechnology (2015). DOI: 10.1038/nbt.3210

Benjamin R. Freedman et al. Biomaterials to Mimic and Heal Connective Tissues, Advanced Materials (2019). DOI: 10.1002/adma.201806695

https://medicalxpress.com/news/2020-09-d-bioprinting-cartilage-rege...

Customizable synthetic antibiotic outmaneuvers resistant bacteria

Antibiotic resistance is one of the world's most urgent public health threats.

Researchers now are tackling antibiotic resistance using a different approach: redesigning existing antibiotic molecules to evade a bacterium's resistance mechanisms. By devising a set of molecular LEGO pieces that can be altered and joined together to form larger molecules, the researchers have created what they hope is the first of many "rebuilds" of drugs that had been shelved due to antibiotic resistance. The aim is to revive classes of drugs that haven't been able to achieve their full potential, especially those already shown to be safe in humans. If we can do that, it eliminates the need to continually come up with new classes of drugs that can outdo resistant bacteria. Redesigning existing drugs could be a vital tool in this effort.

Synthetic group A streptogramin antibiotics that overcome Vat resistance, Nature (2020). DOI: 10.1038/s41586-020-2761-3 , www.nature.com/articles/s41586-020-2761-3

https://phys.org/news/2020-09-customizable-synthetic-antibiotic-out...

Scientists devise 'Trojan horse' approach to kill cancer cells without using drugs

Cancer cells have been killed in lab experiments and tumor growth reduced in mice, using a new approach that turns a nanoparticle into a 'Trojan horse' that causes cancer cells to self-destruct, a research team has found.

The researchers created their 'Trojan horse' nanoparticle by coating it with a specific amino acid—L-phenylalanine—that cancer cells  rely on, along with other similar amino acids, to survive and grow. L-phenylalanine is known as an 'essential' amino acid as it cannot be made by the body and must be absorbed from food, typically from meat and dairy products.

Studies by other research teams have shown that cancer tumor growth can be slowed or prevented by 'starving' cancer cells of amino acids. Scientists believe that depriving cancer cells of amino acids, for example through fasting or through special diets lacking in protein, may be viable ways to treat cancer.

However, such strict dietary regimes would not be suitable for all patients, including those at risk of malnutrition or those with cachexia—a condition arising from chronic illness that causes extreme weight and muscle loss. Furthermore, compliance with the regimes would be very challenging for many patients.

So researchers devised a novel alternative approach. They took a silica nanoparticle designated as 'Generally Recognized As Safe' by the US Food and Drug Administration and coated it with L-phenylalanine, and found that in lab tests with mice it killed cancer cells effectively and very specifically, by causing them to self-destruct.

The anti-cancer therapeutic nanoparticle is ultrasmall, with a diameter of 30 nanometres, or approximately 30,000 times smaller than a strand of human hair, and is named "Nanoscopic phenylalanine Porous Amino Acid Mimic", or Nano-pPAAM.

The scientists tested the efficacy of Nano-pPAAM in the lab and in mice and found that the nanoparticle killed about 80 per cent of breast, skin, and gastric cancer cells, which is comparable to conventional chemotherapeutic drugs like Cisplatin. Tumor growth in mice with human triple negative breast cancer cells was also significantly reduced compared to control models.

Further investigations showed that the amino acid coating of Nano-pPAAM helped the nanoparticle to enter the cancer cells through the amino acid transporter cell LAT1. Once inside the cancer cells, Nano-pPAAM stimulates excessive reactive oxygen species (ROS) production—a type of reactive molecule in the body—causing cancer cells to self-destruct while remaining harmless to the healthy cells.

Zhuoran Wu et al, Potent‐By‐Design: Amino Acids Mimicking Porous Nanotherapeutics with Intrinsic Anticancer Targeting Properties, Small (2020). DOI: 10.1002/smll.202003757

https://phys.org/news/2020-09-scientists-trojan-horse-approach-canc...

Herd immunity at what cost?
So many people have gotten sick in Manaus that researchers say the virus is running out of people to infect.

The city of Manaus, Brazil, might help to reveal what the terrible toll of coronavirus looks like when the virus rages almost unchecked. A preprint study, not yet peer reviewed, shows that between one in 500 and one in 800 people in the city died of the di.... Manaus is fairly young, with just 6% of its population over the age of 60 (in the United States, it’s around 20%). Researchers tested samples from blood banks and estimated that up to 66% of the city’s people have been infected, which they say helped to finally bring down the death rate despite conditions, such as overcrowding, that allow the virus to spread easily.

https://www.technologyreview.com/2020/09/22/1008709/brazil-manaus-c...

MIT Technology Review 
Reference: medRxiv preprint

Sci-Com

with poems

https://physics.aps.org/articles/v13/150

with tweets

Although Twitter is best known for its role in political and cultural discourse, it has also become an increasingly vital tool for scientific communication. A new study shows that Twitter users can be characterized in extremely fine detail by mining a relatively untapped source of information: how those users' followers describe themselves.

https://www.sciencedaily.com/releases/2020/09/200922144321.htm

Sci-Com lecture: DWIH Science Circle Lecture on Exhibiting the Ocean – Communicating Global Challenges

A message was sent to me asking me to share this information ….

In the run-up to the United Nations Decade of the Oceans (2021 – 2030), DWIH New Delhi is engaging with the German Maritime Museum (DSM) to explore aspects of marine research and science communication through museums. Exhibiting the ever-changing sea and ocean ecosystems in a static museum landscape is challenging. This Science Circle Lecture aims at encouraging maritime museums, the science community, and the public to take the evolutionary character of the oceans as an assignment for becoming a marketplace of ideas and reflections on how we can face our common future.

When? Wednesday, 30 September 2020 | 5-6 pm IST

Where? Online, on Adobe Connect. Registration is free but mandatory. Register now!

Speaker: Prof. Dr. Ruth Schilling, Head of Scientific Program and Exhibitions, DSM

You will find more information here:

https://www.dwih-newdelhi.org/en/event/science-circle-lecture-scien...

Researchers find new way to protect plants from fungal infection

Widespread fungal disease in plants can be controlled with a commercially available chemical that has been primarily used in medicine until now. In a comprehensive experiment scientists have uncovered a new metabolic pathway that can be disrupted with this chemical, thus preventing many known plant fungi from invading the host plant.

https://www.sciencedaily.com/releases/2020/09/200922102427.htm

--

Earthquake Sounds Could Reveal How Quickly the Ocean Is Warming

A new way of measuring the temperature of the seas could fill in gaps left by limited direct monitoring

Parkinson's disease is not one, but two diseases

Researchers around the world have been puzzled by the different symptoms and varied disease pathways of Parkinson's patients. A major study has now identified that there are actually two types of the disease: starting either in the brain or in the intestines. Which explains why patients with Parkinson's describe widely differing symptoms, and points towards personalised medicine as the way forward for people with Parkinson's disease.

The study showed that some patients had damage to the brain's dopamine system before damage in the intestines and heart occurred. In other patients, scans revealed damage to the nervous systems of the intestines and heart before the damage in the brain's dopamine system was visible.

This knowledge is important and it challenges the understanding of Parkinson's disease that has been prevalent until now.

1. Jacob Horsager, Katrine B Andersen, Karoline Knudsen, Casper Skjærbæk, Tatyana D Fedorova, Niels Okkels, Eva Schaeffer, Sarah K Bonkat, Jacob Geday, Marit Otto, Michael Sommerauer, Erik H Danielsen, Einar Bech, Jonas Kraft, Ole L Munk, Sandra D Hansen, Nicola Pavese, Robert Göder, David J Brooks, Daniela Berg, Per Borghammer. Brain-first versus body-first Parkinson’s disease: a multimodal imaging case-control study. Brain, 2020; DOI: 10.1093/brain/awaa238

https://www.sciencedaily.com/releases/2020/09/200922092156.htm

Patches to detect worsening viral diseases

Magnetic ‘T-Budbots’ kill and clean biofilms

New brain cell-like nanodevices work together to identify mutations in viruses

In a recent paper publication, scientists have described a new nanodevice that acts almost identically to a brain cell. Furthermore, they have shown that these synthetic brain cells can be joined together to form intricate networks that can then solve problems in a brain-like manner. This is the first study where they have been able to emulate a neuron with just a single nanoscale device.

In particular, the researchers have demonstrated proof of concept that their brain-inspired system can identify possible mutations in a virus, which is highly relevant for ensuring the efficacy of vaccines and medications for strains exhibiting genetic diversity.

Suhas Kumar et al, Third-order nanocircuit elements for neuromorphic engineering, Nature (2020). DOI: 10.1038/s41586-020-2735-5

https://phys.org/news/2020-09-brain-cell-like-nanodevices-mutations...

Twinkling, star-shaped brain cells may hold the key to why, how we sleep

A new study published  suggests that star-shaped brain cells known as astrocytes could be as important to the regulation of sleep as neurons, the brain's nerve cells.

The study builds new momentum toward ultimately solving the mystery of why we sleep and how sleep works in the brain. The discovery may also set the stage for potential future treatment strategies for sleep disorders and neurological diseases and other conditions associated with troubled sleep, such as PTSD, depression, Alzheimer's disease, and autism spectrum disorder.

What we know about sleep has been based largely on neurons. Neurons communicate through electrical signals that can be readily captured through electroencephalography (EEG). Astrocytes—a type of glial (or "glue") cell that interacts with neurons—do not use electrical signals and instead use a process known as calcium  signaling to control their activity.

Looking at astrocytes in the frontal cortex, an area of the brain associated with measurable EEG changes in sleep need, researchers found that astrocytes' activity changes dynamically across the sleep-wake cycle, as is true for neurons. They also observed the most calcium activity at the beginning of the rest phase—when sleep need is greatest—and the least calcium activity at the end of the test phase, when the need for sleep has dissipated.

they also found that sleep deprivation caused an increase in astrocyte calcium activity that decreased after mice were allowed to sleep.

This indicates to us that astrocytes are not just passively following the lead of neurons," said Ingiosi. "And because they don't necessarily display the same activity patterns as neurons, this might actually implicate a more direct role for astrocytes in regulating sleep and sleep need."

 Current Biology (2020). DOI: 10.1016/j.cub.2020.08.052 , www.cell.com/current-biology/f … 0960-9822(20)31242-2

https://medicalxpress.com/news/2020-09-twinkling-star-shaped-brain-...

Glass molecules can act like sand when jammed, study finds

Researchers have discovered that molecules in glass materials behave just like particles in sand and rocks as they jam together, a mechanism that could boost explorations of condensed matter and complex systems.

The work shows that glassy materials change their organizational structure to behave like sand when they are jammed, or compressed to the point of changing from liquid to rigid. The discovery expands the understanding of thermal motion and vibrational states that occur as materials reach jamming.

Francesco Arceri et al. Vibrational Properties of Hard and Soft Spheres Are Unified at Jamming, Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.124.238002

https://phys.org/news/2020-09-glass-molecules-sand.html?utm_source=...

Island-building in Southeast Asia created Earth's northern ice sheets

The Greenland ice sheet owes its existence to the growth of an arc of islands in Southeast Asia—stretching from Sumatra to New Guinea—over the last 15 million years, a new study claims.

According to an analysis by researchers as the Australian continent pushed these volcanic islands out of the ocean, the rocks were exposed to rain mixed with carbon dioxide, which is acidic. Minerals within the rocks dissolved and washed with the carbon into the ocean, consuming enough carbon dioxide to cool the planet and allow for large ice sheets to form over North America and Northern Europe.

Yuem Park el al., "Emergence of the Southeast Asian islands as a driver for Neogene cooling," PNAS (2020). www.pnas.org/cgi/doi/10.1073/pnas.2011033117

https://phys.org/news/2020-09-island-building-southeast-asia-earth-...

Provide shady spots to protect butterflies from climate change, say scientists

https://phys.org/news/2020-09-shady-butterflies-climate-scientists....

Host-driven evolution: A new strategy of cell entry for some types of parvoviruses

Researchers  have discovered a new parvovirus strategy for reaching the cell nucleus, where they reproduce. The parvoviruses are extremely contagious and persistent in the environment. They are transmitted mainly through the feces of infected invertebrates, vertebrates and mammals including humans. To reach the nucleus of host cells, parvoviruses use mostly enzymatic reactions. They are first absorbed by the cell inside a vesicle, a membrane compartment. To escape, parvoviruses activate a viral enzyme domain called phospholipase A2 (PLA2), a key mechanism.

However, some types of parvoviruses, as well as other nonenveloped viruses, do not have this enzyme domain and must therefore escape from the vesicle by some other means. Using molecular biology and structural studies,  researchers have discovered that a new virus targeting the giant tiger shrimp uses a more mechanical response. This type of parvovirus contains an inner pentamer helix bundle held together by calcium ions. When the microorganism is in the vesicle, where the calcium concentration is decreased by the elimination of toxic substances, the bundle is released and opens up the protein shell (capsid) enclosing its genetic material and the membrane, allowing viral DNA to escape into the nucleus for replication.

Judit J. Pénzes et al, Molecular biology and structure of a novel penaeid shrimp densovirus elucidate convergent parvoviral host capsid evolution, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2008191117

https://phys.org/news/2020-09-strategy-cell-entry-parvoviruses.html...

Gravity causes homogeneity of the universe

Gravity can accelerate the homogenization of space-time as the universe evolves. 

The temporal evolution of the universe, from the Big Bang to the present, is described by Einstein's field equations of general relativity. However, there are still a number of open questions about cosmological dynamics, whose origins lie in supposed discrepancies between theory and observation. One of these open questions is: Why is the universe in its present state so homogeneous on large scales?

It is assumed that the universe was in an extreme state shortly after the Big Bang, characterized in particular by strong fluctuations in the curvature of spacetime. During the long process of expansion, the universe then evolved towards its present state, which is homogeneous and isotropic on large scales—in simple terms: the cosmos looks the same everywhere.

This is inferred, among other things, from the measurement of the so-called background radiation, which appears highly uniform in every direction of observation. This homogeneity is surprising in that even two regions of the universe that were causally decoupled from each other—i.e., they could not exchange information—still exhibit identical values of background radiation.

To resolve this supposed contradiction, the so-called inflation theory was developed, which postulates a phase of extremely rapid expansion immediately after the Big Bang, which in turn can explain the homogeneity in the background radiation.

However, how this phase can be explained in the context of Einstein's theory requires a number of modifications of the theory, which seem artificial and cannot be verified directly.

In the concrete problem, the time evolution of the originally strong deviations from the homogeneous state as cosmological gravitational waves has to be analyzed mathematically. It has to be shown that they decay in the course of the expansion thus allowing the universe to get its homogeneous structure.

Such analyses are based on modern mathematical methods in the field of geometric analysis. Until now, these methods could only achieve such results for small deviations from the homogeneous space-time geometry. David Fajman from the University of Vienna has now succeeded for the first time to transfer these methods to the case of arbitrarily large deviations.

 David Fajman. Future Attractors in 2+1 Dimensional Λ Gravity, Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.125.121102

https://phys.org/news/2020-09-gravity-homogeneity-universe.html?utm...

Air pollution leads to increase in electricity usage, study suggests

High levels of air pollution are forcing people inside to consume more electricity, subsequently causing even greater environmental problems by increasing greenhouse gas emissions.

Pan He et al, Increase in domestic electricity consumption from particulate air pollution, Nature Energy (2020). DOI: 10.1038/s41560-020-00699-0

https://phys.org/news/2020-09-air-pollution-electricity-usage.html?...

Lab uncovers new mechanism of action against SARS-CoV-2 by antiviral drug remdesivir

Researchers  have discovered a novel, second mechanism of action by the antiviral drug remdesivir against SARS-CoV-2

The research team previously demonstrated how remdesivir inhibits the COVID-19 virus's polymerase or replication machinery in a test tube.

Remdesivir stops or heavily delays replication of the virus, which in turn reduces propagation and spread.

 It is not common for antiviral drugs to have more than one mechanism of action. The first mechanism his team uncovered affects what is known as the "primer strand" of RNA or the first copy the virus makes of the viral genome as it infects a cell. The second mechanism affects the "template strand" which is repeated over and over as the virus spreads.

Egor P Tchesnokov et al, Template-dependent inhibition of coronavirus RNA-dependent RNA polymerase by remdesivir reveals a second mechanism of action, Journal of Biological Chemistry (2020). DOI: 10.1074/jbc.AC120.015720

https://phys.org/news/2020-09-lab-uncovers-mechanism-action-sars-co...

Using deep learning to control the unconsciousness level of patients in an anesthetic state

Researchers have been developing machine learning algorithms for an increasingly wide range of purposes. This includes algorithms that can be applied in healthcare settings, for instance helping clinicians to diagnose specific diseases or neuropsychiatric disorders or monitor the health of patients over time.

They have recently carried out a study investigating the possibility of using deep reinforcement learning to control the levels of unconsciousness of patients who require anesthesia for a medical procedure. They  made significant progress in understanding how anesthetic medications affect neural activity  and now  a multidisciplinary team is studying how to accurately determine anesthetic doses from neural recordings. They also we trained a neural network using the cross-entropy method, by repeatedly letting it run on simulated patients and encouraging actions that led to good outcomes.  developed a deep neural network and trained it to control anesthetic dosing using reinforcement learning within a simulated environment. 

Controlling level of unconsciousness by titrating Propofol with deep reinforcement learning. arXiv:2008.12333 [cs.LG]. arxiv.org/abs/2008.12333

https://techxplore.com/news/2020-09-deep-unconsciousness-patients-a...

Machine learning takes on synthetic biology: algorithms can bioengineer cells for you

Conventional methods of bioengineering are slow and laborious, with trial and error being the main approach.

So now scientists have developed a new tool that adapts machine learning algorithms to the needs of synthetic biology to guide development systematically. The innovation means scientists will not have to spend years developing a meticulous understanding of each part of a cell and what it does in order to manipulate it; instead, with a limited set of training data, the algorithms are able to predict how changes in a cell's DNA or biochemistry will affect its behaviour, then make recommendations for the next engineering cycle along with probabilistic predictions for attaining the desired goal. According to the developers of this technology, if you're able to create new cells to specification in a couple weeks or months instead of years, you could really revolutionize what you can do with bioengineering.

Nature Communications (2020). DOI: 10.1038/s41467-020-18008-4

https://phys.org/news/2020-09-machine-synthetic-biology-algorithms-...

Materials scientists learn how to make liquid crystal shape-shift

A new 3-D-printing method will make it easier to manufacture and control the shape of soft robots, artificial muscles and wearable devices.  Researchers show that by controlling the printing temperature of liquid crystal elastomer, or LCE, they can control the material's degree of stiffness and ability to contract—also known as degree of actuation. What's more, they are able to change the stiffness of different areas in the same material by exposing it to heat.

As a proof of concept, the researchers 3-D-printed in a single print, with a single ink, structures whose stiffness and actuation varies by orders of magnitude, from zero to 30 percent. For example, one area of the LCE structure can contract like muscles; and another can be flexible, like tendons. The breakthrough was possible because the team studied LCE closely to better understand its material properties.

 "Three-dimensional printing of functionally graded liquid crystal elastomer" Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abc0034

https://phys.org/news/2020-09-materials-scientists-liquid-crystal-s...

Research challenges conventional wisdom about key autism trait

https://medicalxpress.com/news/2020-09-conventional-wisdom-key-auti...

--

Scientists capture light in a polymeric quasicrystal

https://phys.org/news/2020-09-scientists-capture-polymeric-quasicry...

--

https://www.sciencemag.org/news/2020/09/how-neanderthals-lost-their...

How Neanderthals lost their Y chromosome

--

Can fitness bands predict COVID-19 infection before you show symptoms? Probably not

WHOOP’s wearables make strong claims — but the science is still weak

https://massivesci.com/articles/whoop-wearable-fitness-tracker-covi...

--

How microbes in a mother's intestines affect fetal neurodevelopment

https://researchnews.cc/news/2691/How-microbes-in-a-mother-s-intest...

--

Dogs Deployed at Airport Can Detect COVID-19

https://www.sciencealert.com/dogs-deployed-at-helsinki-airport-can-...

--

 The Massive 'Blob' Anomaly Has Our Fingerprints All Over It, Study Finds

https://www.sciencealert.com/the-foreboding-pacific-blob-anomaly-ha...

The male Y chromosome does more than we thought

New light is being shed on a little-known role of Y chromosome genes, specific to males, that could explain why men suffer differently than women from various diseases, including COVID-19. This  discovery provides a better understanding of how male genes on the Y chromosome allow male cells to function differently from female cells. These results could help to shed some light on why some diseases occur differently in men and women.

Humans each have 23 pairs of chromosomes, including one pair of sex chromosomes. While females carry two X sex chromosomes, males carry one X and one Y chromosome. This male chromosome carries genes that females lack. Although these male genes are expressed in all cells of the body, their only confirmed role to date has been essentially limited to the functions of the sex organs.

In his study, scientists performed a genetic manipulation that inactivated two male genes on the Y chromosome, altering several signalling pathways that play important roles in certain functions of non-sex organ cells. For example, under stress, some of the affected mechanisms could influence the way in which cells in human hearts defend themselves against aggressions such as ischemia (reduced blood supply) or mechanical stress.

In addition, the study showed that these male genes performed their regulatory functions in a way that was unusual compared to the mechanisms generally used by most other genes on the non-sex chromosomes. Thus, instead of specifically activating certain genes by direct action at the genome level, the Y chromosome seems to affect cellular functions by acting on protein production.

The discovery of these differences in function may explain in part why the functions of male Y chromosome genes have so far been poorly understood.

Males differ from females in the manifestation, severity and consequences of most diseases. A recent example of this duality is COVID-19, which has a mortality rate twice as high in men than in women.

Christian F. Deschepper, Regulatory effects of the Uty/Ddx3y locus on neighboring chromosome Y genes and autosomal mRNA transcripts in adult mouse non-reproductive cells, Scientific Reports (2020). DOI: 10.1038/s41598-020-71447-3

https://phys.org/news/2020-09-male-chromosome-thought.html?utm_sour...

 Secure nano-carrier delivers medications directly to cells

Medications often have unwanted side-effects. One reason is that they reach not only the unhealthy cells for which they are intended, but also reach and have an impact on healthy cells. Researchers  have now developed a stable nano-carrier for medications. A special mechanism makes sure the drugs are only released in diseased cells.

 Ceren Kimna et al, DNA Strands Trigger the Intracellular Release of Drugs from Mucin-Based Nanocarriers, ACS Nano (2020). DOI: 10.1021/acsnano.0c04035

https://phys.org/news/2020-09-nano-carrier-medications-cells.html?u...

New measurements show moon has hazardous radiation levels

Future moon explorers will be bombarded with two to three times more radiation than astronauts aboard the International Space Station, a health hazard that will require thick-walled shelters for protection, scientists reported  recently.

China's lander on the far side of the moon is providing the first full measurements of radiation exposure from the lunar surface, vital information for NASA and others aiming to send astronauts to the moon, the study noted.

Astronauts would get 200 to 1,000 times more radiation on the moon than what we experience on Earth—or five to 10 times more than passengers on a trans-Atlantic airline flight.

The difference is, however, that we're not on such a flight for as long as astronauts would be when they're exploring the moon. Cancer is the primary risk.

Humans are not really made for these radiation levels and should protect themselves when on the moon. Radiation levels should be pretty much the same all over the moon, except for near the walls of deep craters.

S. Zhang el al., First measurements of the radiation dose on the lunar surface, Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.aaz1334

https://phys.org/news/2020-09-moon.html?utm_source=nwletter&utm...

Bird genes are multitaskers, say scientists

Scientists  have found that although male and female birds have an almost identical set of genes, they function differently in each sex through a mechanism called alternative splicing.

Males and females of the same bird species can be strikingly different. For example, in addition to fundamental differences in reproduction, the sexes can show profound variation in behavior, colouration, metabolism, disease incidence and life history. The team wanted to understand how these remarkable differences develop despite males and females sharing mostly the same DNA.

One notable example of differences between male and female birds is in the peafowl, peacocks have magnificent plumage, whereas the female peahen is relatively dull. The peacock's long tail and bright colours evolved to help them attract mates, but having such eye-catching looks can come with negatives such as making them more noticeable to predators.

Features like this are beneficial to the males but may not be beneficial for females, so birds must find a way to evolve different characteristics. So researchers predicted that the secret to these differences must lie in understanding how the same genes are expressed and function differently in males and females.

The team studied the genomes of multiple bird species to understand how they expressed these different qualities in males and females.

Genes encode proteins, large complex molecules which drive processes in the body and are responsible for the function and structure of the body's tissues. Before genes can be used to make proteins, their DNA sequence is transcribed into RNA, an intermediary molecule that contains the instructions for making proteins.

The scientists found that males and females differ in how bits of RNA are stitched together, meaning that the same gene can produce a large number of distinct proteins and functions depending on which sex the gene is expressed in. This process is called alternative splicing. It is likely that this genetic process is really important for generating biodiversity, not only in birds but across the whole animal kingdom. The study  revealed hundreds of bird genes that use this method to enable the evolution of sex differences. The researchers showed that these genes have evolved remarkably rapidly as a result of the different selection pressures experienced by males and females.

https://academic.oup.com/mbe/advance-article/doi/10.1093/molbev/msa...

https://phys.org/news/2020-09-bird-genes-multitaskers-scientists.html

Possible signs of life on Venus

Autopsies Show Varied Forms of Heart Damage in COVID-19 Patients

The multifarious nature of the damage means treatments for cardiac issues during infection will require tailored approaches.

https://www.the-scientist.com/news-opinion/autopsies-show-varied-fo...

--

Physicists Argue That Black Holes From the Big Bang Could Be the Dark Matter

A Man Has Died After Eating Bags of Black Licorice Daily

A man in Massachusetts died after eating too much black licorice, which contains a compound known to be toxic in large doses, according to a new report. The 54-year-old man was in a fast food restaurant when he suddenly gasped, began shaking and lost consciousness, according to the report Emergency medical personnel found that the man was experiencing ventricular fibrillation, a life-threatening heart rhythm problem. The man received CPR and briefly regained consciousness before being rushed to the hospital. A discussion with the man's family revealed that he had a poor diet, consuming one to two large packages of soft candy every day, and little else. A few weeks earlier, the man had switched from eating red, fruit-flavored candy to black licorice candy. Black licorice often contains a compound called glycyrrhizin, which is derived from licorice root. Consuming too much licorice root or candies flavored with licorice root can be dangerous because glycyrrhizin lowers the body's potassium levels. This, in turn, can lead to high blood pressure and abnormal heart rhythms.

In the man's case, very low potassium levels led to his heart problems. The man received treatment to restore his potassium levels, along with multiple other treatments in the intensive care unit, including being placed on a ventilator. Despite these efforts, the man died 32 hours after arriving at the hospital. 

Although the death is an "extreme case," eating just 2 ounces of black licorice a day for two weeks can cause heart rhythm problems, particularly for people ages 40 and older.

https://www.livescience.com/black-licorice-death.html

https://www.sciencealert.com/man-dies-from-eating-black-licorice-da...

Body fat deep below the surface is a toxic risk, especially for your heart

BMI can’t provide information about the shape and size of potentially dangerous internal fat deposits, known as “visceral fat”. Over recent years it’s become apparent visceral fat can lead to disease, and good fat can turn into toxic fat when there is too much.

Various organs seem to accumulate visceral fat. This can be a problem because it can create and release damaging molecules and hormones into the blood. These are transported in the bloodstream, potentially causing health complications in distant parts of the body.

For example, toxic fat can release proteins that blunt the body’s sensitivity to insulin. Blood glucose levels then rise, potentially causing diabetes in the long term. Visceral fat can also stimulate uncontrolled cell growth and replication, potentially triggering some forms of cancer. A fatty liver is associated with metabolic diseases, and excess kidney fat interferes with the body’s fluid balance.

The heart is especially vulnerable

https://theconversation.com/body-fat-deep-below-the-surface-is-a-to...

Seven Warning Signs of Bogus Science

1. The discoverer pitches the claim directly to the media.

2. The discoverer says that a powerful establishment is trying to suppress his or her work.

3. The scientific effect involved is always at the very limit of detection.

4. Evidence for a discovery is anecdotal.

5. The discoverer says a belief is credible because it has endured for centuries.

6. The discoverer has worked in isolation.

7. The discoverer must propose new laws of nature to explain an observation.

https://quackwatch.org/related/signs/

White supremacists believe in genetic ‘purity’. Science shows no such thing exists

Science does not support the idea of pure races with ancient origins. In the past few years, genetic sequencing of ancient and modern humans and related species has given us a flood of new information about how human populations have evolved.

The evidence reveals a history of ongoing genetic mingling, due to interbreeding between different populations and even species. Humans from different groups had children together, and even with Neanderthals and members of other now-extinct hominin species.

This mingling occurred constantly in the long process of human migration across the globe. Europeans inhabit one region of a large genetic continuum and are no more or less “pure” than any other population.

https://theconversation.com/white-supremacists-believe-in-genetic-p...

Antifungal preventive drugs reduce mortality risk following lung transplantation: Study

The retrospective study, published in the Annals of the American Thoracic Society, is the largest ever to evaluate the effectiveness of antifungal preventive drugs in lung transplant recipients who are particularly susceptible to invasive fungal infections. These infections are associated with a nearly threefold increase in mortality for lung transplant recipients.

The study showed that  the risk of death within the first year posttransplant is about twice as high in patients not receiving antifungal preventive treatment, compared with those receiving treatment.

https://www.atsjournals.org/doi/abs/10.1513/AnnalsATS.202003-267OC

Ecologists confirm Alan Turing's theory for fairy circles

Fairy circles are one of nature's greatest enigmas and most visually stunning phenomena. An international research team has now, for the first time, collected detailed data to show that Alan Turing's model explains the striking vegetation patterns of the Australian fairy circles. In addition, the researchers showed that the grasses that make up these patterns act as "eco-engineers" to modify their own hostile and arid environment, thus keeping the ecosystem functioning.

Researchers used drone technology, spatial statistics, quadrat-based field mapping, and continuous data-recording from a field-weather station. With the drone and a multispectral camera, the researchers mapped the "vitality status" of the Triodia grasses (how strong and how well they grew) in five one-hectare plots and classified them into high- and low-vitality.

The systematic and detailed fieldwork enabled, for the first time in such an ecosystem, a comprehensive test of the 'Turing pattern' theory. Turing's concept was that in certain systems, due to random disturbances and a 'reaction-diffusion' mechanism, interaction between just two diffusible substances was enough to allow strongly patterned structures to spontaneously emerge. Physicists have used this model to explain the striking skin patterns in zebrafish or leopards for instance.

The data show that the unique gap pattern of the Australian fairy circles, which occur only in a small area east of the town of Newman, emerges from ecohydrological biomass-water feedbacks from the grasses. In fact, the fairy circles—with their large diameters of 4m, clay crusts from weathering and resultant water run-off—are a critical extra source of water for the dryland vegetation. Clumps of grasses increased shading and water infiltration around the nearby roots. With increasing years after fire, they merged more and more at the periphery of the vegetation gaps to form a barrier so that they could maximize their water uptake from the fairy circle's runoff. The protective plant cover of grasses could reduce soil-surface temperatures by about 25°C at the hottest time of the day, which facilitates the germination and growth of new grasses. In summary, the scientists found evidence both at the scale of the landscape and at much smaller scales that the grasses, with their cooperative growth dynamics, redistribute the water resources, modulate the physical environment, and thus function as "ecosystem engineers" to modify their own environment and better cope with the arid conditions.

Stephan Getzin et al, Bridging ecology and physics: Australian fairy circles regenerate following model assumptions on ecohydrological feedbacks, Journal of Ecology (2020). DOI: 10.1111/1365-2745.13493

https://phys.org/news/2020-09-ecologists-alan-turing-theory-austral...

Metformin treatment linked to slowed cognitive decline

Metformin is the first-line treatment for most cases of type 2 diabetes and one of the most commonly prescribed medications worldwide, with millions of individuals using it to optimize their blood glucose levels.

A new research study, conducted over six years 

 has revealed an additional effect: individuals with type 2 diabetes who used metformin experienced slower cognitive decline with lower dementia rates than those who did not use the medication.

The findings provide new hope for a means of reducing the risk of dementia in individuals with type 2 diabetes, and potentially those without diabetes who number nearly 47 million people worldwide.

Diabetes Care (2020). DOI: 10.2337/dc20-0892

https://medicalxpress.com/news/2020-09-metformin-treatment-linked-c...

--

Scientists discover why tarantulas come in vivid blues and greens

https://phys.org/news/2020-09-scientists-tarantulas-vivid-blues-gre...

Researchers show conscious processes in birds' brains for the first time

By measuring brain signals, a neuroscience research group has demonstrated for the first time that corvid songbirds possess subjective experiences. Simultaneously recording behavior and brain activity enabled the group  to show that crows are capable of consciously perceiving sensory input. Until now this type of consciousness has only been witnessed in humans and other primates, which have completely different brain structures to birds.

For humans and our nearest relatives in the animal kingdom, the nonhuman primates, our ability to perceive things consciously is localized in the cerebral cortex. Over many years research has discussed whether animals with brains that are structured completely differently, without a cerebral cortex, are also endowed with conscious perception. Until now however there has been no experimental neurological data to support such a claim.

In order to track conscious processes in birds, the Tübingen scientists trained two crows: they had to signal whether they had seen a stimulus on a screen by moving their heads. Most of the stimuli were perceptually unambiguous: different trials presented either bright figures or no stimulus at all, and the crows reliably signaled the presence or absence of these stimuli, respectively. However, some stimuli were so faint that they were at the threshold of perception: for the same faint stimulus, the crows sometimes indicated that they had seen it, whereas in other cases they reported that there was no stimulus. Here, the subjective perception of the crows came into play.

While the crows responded to the visual stimuli, the researchers simultaneously recorded the activity of individual nerve cells in the brain. When the crows reported having seen something, the nerve cells were active in the period between presentation of the stimulus and the behavioral response. If they did not perceive a stimulus, the nerve cells remained silent. Surprisingly, it was possible to predict the subjective experience of the crows with regard to the stimulus based on the activity of the nerve cells.

These results conclusively show that nerve cells at higher processing levels of the crow's brain are influenced by subjective experience, or more precisely, produce subjective experiences."

This means that in terms of evolutionary history the origins of consciousness could be far older and more widespread in the animal kingdom than previously thought. the capability of conscious experience can be realized in differently structured brains and independently of the cerebral cortex.

Nieder et al., A neural correlate of sensory consciousness in a corvid bird. Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abb1447

https://phys.org/news/2020-09-conscious-birds-brains.html?utm_sourc...