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Comment by Dr. Krishna Kumari Challa on September 17, 2020 at 5:49am

Native stinging tree toxins match the pain of spiders and scorpions

The painful toxins wielded by a giant  stinging tree are surprisingly similar to the venom found in spiders and cone snails researchers have found.

The Gympie-Gympie stinging tree is one of the world's most venomous plants and causes extreme long-lasting pain. Researchers found a new family of toxins, which they've named 'gympietides' after the Gympie-Gympie stinging tree.

The tree's scientific name is Dendrocnide which literally means 'stinging tree'—a member of the nettle family. Like other stinging plants such as nettles, the giant stinging tree is covered in needle-like appendages called trichomes that are around five millimetres in length—the trichomes look like fine hairs, but actually act like hypodermic needles that inject toxins when they make contact with skin.

 Small molecules in the trichomes such as histamine, acetylcholine and formic acid have been tested but injecting these does not cause the severe and long-lasting pain of the stinging tree, suggesting that there was an unidentified neurotoxin to be found.

Although they come from a plant, the gympietides are similar to spider and cone snail toxins in the way they fold into their 3-D molecular structures and target the same pain receptors—this arguably makes the Gympie-Gympie tree a truly "venomous" plant. The long-lasting pain from the stinging tree may be explained by the gympietides permanently changing the sodium channels in the sensory neurons, not due to the fine hairs getting stuck in the skin.

By understanding how this toxin works, scientists hope to provide better treatment to those who have been stung by the plant, to ease or eliminate the pain.

With these toxins from both plants and animals having a shared method of causing pain, it begs the question, when and how did these toxins evolve?

The researchers point to two possibilities for the toxin's evolution from either an ancestral gene in an ancient shared ancestor or convergent evolution, where nature re-invents the most fitting structure to fit a common purpose.

E.K. Gilding el al., "Neurotoxic peptides from the venom of the giant Australian stinging tree," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb8828

https://phys.org/news/2020-09-native-tree-toxins-pain-spiders.html?...

Comment by Dr. Krishna Kumari Challa on September 17, 2020 at 5:38am

How Dantu Blood Group protects against malaria—and how all humans could benefit

In 2017, researchers discovered that the rare Dantu blood variant, which is found regularly only in parts of East Africa, provides some degree of protection against severe malaria.

The secret of how the Dantu genetic blood variant helps to protect against malaria has been revealed for the first time by scientists now. They found that red blood cells in people with the rare Dantu blood variant have a higher surface tension that prevents them from being invaded by the world's deadliest malaria parasite, Plasmodium falciparum.

Analysis of the characteristics of the red blood cell samples indicated that the Dantu variant created cells with a higher surface tension—like a drum with a tighter skin. At a certain tension, malaria parasites were no longer able to enter the cell, halting their lifecycle and preventing their ability to multiply in the blood. The Dantu blood group has a novel 'chimeric' protein that is expressed on the surface of red blood cells, and alters the balance of other surface proteins.

This finding could also be significant in the wider battle against malaria. Because the surface tension of human red blood  cells increases as they age, it may be possible to design drugs that imitate this natural process to prevent malaria infection or reduce its severity.

Red blood cell tension protects against severe malaria in the Dantu blood group, Nature (2020). DOI: 10.1038/s41586-020-2726-6 , www.nature.com/articles/s41586-020-2726-6

https://medicalxpress.com/news/2020-09-dantu-blood-group-malariaand...

Comment by Dr. Krishna Kumari Challa on September 17, 2020 at 5:12am

A new strategy for the viral manipulation of interneurons in mice and other mammals

the use of viral vectors that were developed by identifying short sequences of DNA restricting the expression of a virus onto the desired target cell type.

Viral manipulation of functionally distinct interneurons in mice, non-human primates and humans. Nature Neuroscience (2020). DOI: 10.1038/s41593-020-0692-9.

https://medicalxpress.com/news/2020-09-strategy-viral-interneurons-...

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Harnessing DNA molecules for disease detection and electronics

DNA molecules express heredity through genetic information. However, in the past few years, scientists have discovered that DNA can conduct electrical currents. This makes it an interesting candidate for roles that nature did not intend for this molecule, such as smaller, faster and cheaper electric circuits in electronic devices, and to detect the early stages of diseases like cancer and COVID-19.

The  most surprising recent finding was that the current passes through the DNA backbone, contrary to prior assumptions in the scientific community that the current flowed along DNA base pairs. 

 Roman Zhuravel et al. Backbone charge transport in double-stranded DNA, Nature Nanotechnology (2020). DOI: 10.1038/s41565-020-0741-2

https://phys.org/news/2020-09-harnessing-dna-molecules-disease-elec...

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 9:20am

Keeping MAX quiet with Chevrons.

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 8:47am

will the tropics eventually become uninhabitable?

https://theconversation.com/climate-explained-will-the-tropics-even...

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A computer can guess more than 100,000,000,000 passwords per second. Still think yours is secure?

https://theconversation.com/a-computer-can-guess-more-than-100-000-...

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Earth’s rarest diamonds form from primordial carbon in the mantle

https://www.sciencenews.org/article/earth-rarest-diamonds-form-prim...

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Athletes show signs of possible heart injury after COVID-19

A small study found indicators of inflammation in images of some athletes’ hearts

https://www.sciencenews.org/article/covid19-coronavirus-heart-injur...

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Research reveals an enormous planet quickly orbiting a tiny, dying star

https://phys.org/news/2020-09-reveals-enormous-planet-quickly-orbit...

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https://www.quora.com/q/sciencecommunication/New-finding-A-lack-of-...; - check &&

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 7:02am

The multiple benefits of a world without air conditioning  and how you can ‘get cooled’ without AC

https://phys.org/news/2020-09-qa-multiple-benefits-world-air.html?u...

https://www.quora.com/q/sciencecommunication/The-multiple-benefits-...  -- check%%

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 6:58am

Human white blood cells use molecular paddles to swim

Human white blood cells, known as leukocytes, swim using a newly described mechanism called molecular paddling, researchers report

This microswimming mechanism could explain how both immune cells and cancer cells migrate in various fluid-filled niches in the body, for good or for harm.

Cells have evolved different strategies to migrate and explore their environment. For example, sperm cells, microalgae, and bacteria can swim through shape deformations or by using a whip-like appendage called a flagellum. By contrast, somatic mammalian cells are known to migrate by attaching to surfaces and crawling. It is widely accepted that leukocytes cannot migrate on 2-D surfaces without adhering to them.

A prior study reported that certain human white blood cells called neutrophils could swim, but no mechanism was demonstrated. Another study showed that mouse leukocytes could be artificially provoked to swim. It is widely thought that cell swimming without a flagellum requires changes in cell shape, but the precise mechanisms underlying leukocyte migration have been debated.

This new study provide experimental and computational evidence  that human leukocytes can migrate on 2-D surfaces without sticking to them and can swim using a mechanism that does not rely on changes in cell shape. The cells paddle using transmembrane proteins, which span the cell membrane and protrude outside the cell. The researchers show that membrane treadmilling—rearward movement of the cell surface—propels leukocyte migration in solid or liquid environments, with and without adhesion.

Laurene Aoun et al, Amoeboid Swimming Is Propelled by Molecular Paddling in Lymphocytes, Biophysical Journal (2020). DOI: 10.1016/j.bpj.2020.07.033

https://phys.org/news/2020-09-human-white-blood-cells-molecular.htm...

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 6:12am

Ocean algae get 'coup de grace' from viruses

Scientists thought till now that ocean viruses always quickly kill algae, but new research now shows they live in harmony with algae and viruses provide a "coup de grace" (a final blow or shot given to kill a wounded person or animal) only when blooms of algae are already stressed and dying.

This new finding will likely change how scientists view viral infections of algae, also known as phytoplankton—especially the impact of viruses on ecosystem processes like algal bloom formation (and decline) and the cycling of carbon and other chemicals on Earth. It's only when the infectedalgal cells become stressed, such as when they run out of nutrients, that the viruses turn deadly. This entirely new model of infection is widespread in the oceans and stands to fundamentally alter how we view host-virus interactions and the impact of viruses on ecosystems and biogeochemical cycling since it goes against the long-accepted classic model of viruses always being lethal and killing cells.

Nature Communications (2020). DOI: 10.1038/s41467-020-18078-4

https://phys.org/news/2020-09-ocean-algae-coup-de-grace.html?utm_so...

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 6:05am

Did our early ancestors boil their food in hot springs?

Microbial biomarkers reveal a hydrothermally active landscape at Olduvai Gorge at the dawn of the Acheulean, 1.7 Ma, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2004532117 , www.pnas.org/content/early/2020/09/14/2004532117

https://phys.org/news/2020-09-early-ancestors-food-hot.html?utm_sou...

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Molecular basis underlying colorectal cancer revealed

https://medicalxpress.com/news/2020-09-molecular-basis-underlying-c...

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Reward and punishment take similar paths in the mouse brain

https://medicalxpress.com/news/2020-09-reward-similar-paths-mouse-b...

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Why a vaccine can provide better immunity than an actual infection  

https://theconversation.com/why-a-vaccine-can-provide-better-immuni...

Comment by Dr. Krishna Kumari Challa on September 16, 2020 at 6:02am

Tortoise hatchlings found to orient toward objects resembling faces

Researchers have found that freshly hatched tortoises tend to orient themselves toward objects that resemble a face. 

Anecdotal as well as lab research has shown that newly born humans tend to orient their faces toward the face of their mother. Likewise, other animals have been found to do the same. Social scientists have shown that the behavior is hereditary and have theorized that it is part of bonding. In this new effort, the researchers found evidence that suggests face orienteering goes deeper than that, and perhaps goes farther back in evolution than has been thought—to an ancestor common to both humans and reptiles.

To test the possibility of face orienteering in reptiles, the researchers created simple face-like structures by pasting square black blocks onto a white plate, vaguely resembling eyes, nose and mouth. They also pasted the same sort of blocks in other ways on other plates in ways not resembling a face. They then set newly hatched tortoises in the vicinity of their creations and watched how they behaved. In all, the researchers tested 136 tortoises from five Testudo species. In tallying up their results, they found that the tortoise hatchlings oriented themselves toward the faces approximately 70% of the time. In sharp contrast, they showed no preference for any of the structures that did not resemble faces.

The researchers suggest their finding is notable because tortoises are notoriously antisocial creatures. They receive no care from their parents and avoid other tortoises when they see them. They also do not interact with animals of other species. Thus, their inclination to orient themselves toward a face suggests it originates in their genes. Prior research has shown that modern tortoises first appeared around 30 million years ago, which suggests that facial attraction may go back even farther in history—perhaps to a shared common ancestor of humans and reptiles.

Elisabetta Versace et al. Early preference for face-like stimuli in solitary species as revealed by tortoise hatchlings, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2011453117

https://phys.org/news/2020-09-tortoise-hatchlings-resembling.html?u...

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