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Comment by Dr. Krishna Kumari Challa on November 5, 2021 at 10:25am

https://www.karger.com/Article/Abstract/63018

https://www.pnas.org/content/118/45/e2112494118

https://www.pnas.org/content/118/45/e2112494118

part2

Comment by Dr. Krishna Kumari Challa on November 5, 2021 at 10:02am

Researchers identify bird and reptile 'microchromosomes' once thought to be dust specks on a microscope slide

 Scientists have discovered that tiny 'microchromosomes' in birds and reptiles, initially thought to be specks of dust on the microscope slide, are linked to a spineless animal ancestor that lived 684 million years ago. They prove to be the building blocks of all animal genomes, but underwent "dizzying rearrangement" in mammals, including humans.

A team of researchers made the discovery by lining up the DNA sequence of microchromosomes that huddle together in the cells of birds and reptiles.

When these little microchromosomes were first seen under the microscope, scientists thought they were just specks of dust among the larger bird chromosomes, but they are actually proper chromosomes.

Using advanced DNA sequencing technology, scientists can at last sequence microchromosomes end-to-end.

Researchers lined up these sequences from birds, turtles, snakes and lizards, platypus and humans and compared them. Astonishingly, the microchromosomes were the same across all bird and reptile species. Even more astonishingly, they were the same as the tiny chromosomes of Amphioxus—a little fish-like animal with no backbone that last shared a common ancestor with vertebrates 684 million years ago.

 In marsupial and placental mammals these ancient genetic remnants are split up into little patches on our big, supposedly normal, chromosomes. The exception is the platypus genome, in which the microchomosomes have all fused together into a few large blocks that reflect our oldest mammal ancestor.  the findings highlight the need to rethink how we view the human genome.

Microchromosomes form a compartment in the cell that might help the genes work together.

Rather than being 'normal,' chromosomes of humans and other mammals were puffed up with lots of 'junk DNA' and scrambled in many different ways. The new knowledge helps explain why there is such a large range of mammals with vastly different genomes inhabiting every corner of our planet. 

https://researchnews.cc/news/9809/Researchers-identify-bird-and-rep...

https://theconversation.com/specks-of-dust-on-the-microscope-slide-...

Part1

Comment by Dr. Krishna Kumari Challa on November 5, 2021 at 9:55am

Vascular disease in COVID-19 is not caused by viral infection of blood vessels

Comment by Dr. Krishna Kumari Challa on November 4, 2021 at 12:09pm

Back in the laboratory, Leonards and her collaborators investigated the effects of four illusory patterns on people’s walking experience. Two of the designs, consisting of black-and-white alternating “furrows and ridges” modeled after the undulating pattern in Rossio Square, looked three-dimensional despite being printed on flat surfaces. More than half of the walkers found such designs aversive or uncomfortable to tread on, affecting their stability and even occasionally inducing fear of falling. The discomfort may lie in the mismatch between the sensory and physical characteristics of the walking environment. In nature, surfaces that look bumpy are generally bumpy, but this was not the case for the floor patterns examined in the study—a concern that may extend to a number of human-built environments.

The clue to avoiding the clash of art and accessibility, Leonards says, is to bring people into the planning process directly from the start and think of the project in a human-centered way. “I don’t think that this comes at the cost of aesthetics,” she explains, “but rather allows a far bigger group of people to enjoy beautiful places safely.”

This article was originally published with the title "The Twisted Paths of Perception" in SA Mind 32, 6, 33-34 (November 2021)

doi:10.1038/scientificamericanmind1121-33

https://www.scientificamerican.com/article/the-twisted-paths-of-per...

Part 2

Comment by Dr. Krishna Kumari Challa on November 4, 2021 at 12:08pm

The Twisted Paths of Perception

These patterned pavements make pedestrians watch their step

The King Pedro IV Square in Lisbon, Portugal, better known as the Rossio, regales visitors with a delightful exemplar of the traditional pavement called calçada portuguesa. Originally cobbled in 1848, the dizzying light and dark undulations symbolize the sea voyages of Portuguese navigators and predate 20th-century designs by Op Art creators such as Victor Vasarely and Bridget Riley, while inducing similar perceptions of flowing motion. But does the vibrant pattern stand in the way of safety?

A recent study from the University of Bristol in England asked participants how walking on floors patterned with visual illusions affected their discomfort levels and feeling of instability. Neuropsychologist Ute Leonards, who led the study, first considered the potential negative impact of such illusory patterns on walking during a visit to the iconic street of La Rambla in Barcelona, Spain. “I had noticed the 3-D effect of the floor patterns and wanted to add them to my collection,” she recalls. As Leonards photographed the waves in the paving design, an older gentleman approached her. “He said that he didn’t like the floor at all, as he wasn’t sure when his feet would actually hit the ground and how high he should lift his feet not to trip . . . he walked [as if] afraid that there might be black ice.”

Part1 

Comment by Dr. Krishna Kumari Challa on November 4, 2021 at 11:12am

Using microbes to make carbon-neutral fuel

Researchers  have discovered a new way to train microbes to make a readily usable biofuel.

A team of biologists and engineers modified a microbe called Rhodopseudomonas palustris TIE-1 (TIE-1) so that it can produce a biofuel using only three renewable and naturally abundant source ingredients: carbon dioxide, solar panel-generated electricity and light.

The resulting biofuel, n-butanol, is an authentically carbon-neutral fuel alternative that can be used in blends with diesel or gasoline. The results are reported Nov. 3 in the journal Communications Biology.

 n-Butanol production by Rhodopseudomonas palustris TIE-1, Communications Biology (2021). DOI: 10.1038/s42003-021-02781-z

https://techxplore.com/news/2021-11-microbes-carbon-neutral-fuel.ht...

Comment by Dr. Krishna Kumari Challa on November 4, 2021 at 11:04am

Ecosystems worldwide are disrupted by lack of large wild herbivores—except in Africa

Biological research has repeatedly demonstrated that the relationship between the producer and the consumer is governed by a scaling law. An international research team has now looked into whether this law of nature can be reproduced in the relationship between the production of plants in an area and the number of large herbivores that graze on them. The study reveals that Africa is the only continent where the scaling law holds true.

June 2021 saw the start of the United Nations Decade on Ecosystem Restoration. A total of 115 countries have committed themselves to restoring up to a billion hectares of nature worldwide.

According to a group of researchers from Aarhus University and the University of Sussex, one of biggest challenges will be restoring the historical and prehistoric grazing of large mammals. What level of restoration should we aim for? How many large herbivores will we need? And how are we going to co-exist with these large animals?

The researchers examined the current low densities of large herbivores in a scientific article in the Journal of Applied Ecology. In the article, they calculated a baseline for large animals based on the ratio between producer and consumer, i.e. plants and herbivores, in nature reserves in Africa.

They stress that this relationship between producers and consumers applies across ecosystems and biomes implying a close correlation between the biomass produced and the biomass of dependent consumers.

However, after investigating the density of large herbivores in  nature reserves throughout the world, the researchers were only able to find such a close correlation on one continent: Africa. On the other continents, they found strong indications of impoverished fauna, even in protected natural areas.

African ecosystems have species-rich mammal fauna and a large biomass of big herbivores that are significantly linked to plant productivity. But we can't find this pattern on other continents, and in general the large herbivore biomass is much lower than we would expect considering the level of productivity.

In the article, the researchers argue that large herbivores are still being displaced, hunted and eradicated, and that there is a widespread perception, even among game managers, that there are plenty of herbivores in the wild, perhaps even too many. This perception is not supported by the new study.

On the contrary, efforts to decrease populations of large herbivores can reflect a shifting baseline.

Bringing back big animals is crucial to restoring self-sustaining ecosystems and conserving biodiversity, but it is not going to be easy. Large animals are troublesome, because they damage crops, disrupt traffic and generally just get in the way. It will require political commitment and careful physical planning, including fenced reserves.

Camilla Fløjgaard et al, Exploring a natural baseline for large‐herbivore biomass in ecological restoration, Journal of Applied Ecology (2021). DOI: 10.1111/1365-2664.14047

https://phys.org/news/2021-11-ecosystems-worldwide-disrupted-lack-l...

Comment by Dr. Krishna Kumari Challa on November 3, 2021 at 11:39am

COVID-19 virus test sensitivity follows the body’s circadian rhythm

Comment by Dr. Krishna Kumari Challa on November 3, 2021 at 11:30am

Researchers discover new type of nerve cell in the retina

Scientists have discovered a new type of nerve cell, or neuron, in the retina.

In the central nervous system, a complex circuitry of neurons communicate with each other to relay sensory and motor information; so-called interneurons serve as intermediaries in the chain of communication. Publishing in the Proceedings of the National Academy of Sciences of the United States of America, a research team  identifies a previously unknown type of interneuron in the mammalian retina.

The discovery marks a notable development for the field as scientists work toward a better understanding of the central nervous system by identifying all classes of neurons and their connections.

Based on its morphology, physiology, and genetic properties, this cell doesn't fit into the five classes of retinal neurons first identified more than 100 years ago. Researchers, therefore, propose they might belong to a new retinal neuron class by themselves.

The research team named their discovery the Campana cell after its shape, which resembles a hand bell. Campana cells relay visual signals from both types of light-sensing rod and cone photoreceptors in the retina, but their precise purpose is the subject of ongoing research. Experiments showed Campana cells remain activated for an unusually long time—as long as 30 seconds—in response to a 10 millisecond light flash stimulation.

In the brain, persistent firing cells are believed to be involved in memory and learning. Since Campana cells have a similar behavior, we theorize they could play a role in prompting a temporal 'memory' of a recent stimulation.

Brent K. Young, Charu Ramakrishnan, Tushar Ganjawala, Ping Wang, Karl Deisseroth, Ning Tian. An uncommon neuronal class conveys visual signals from rods and cones to retinal ganglion cells. Proceedings of the National Academy of Sciences, 2021; 118 (44): e2104884118 DOI: 10.1073/pnas.2104884118

https://researchnews.cc/news/9777/Researchers-discover-new-type-of-...

Comment by Dr. Krishna Kumari Challa on November 3, 2021 at 8:56am

Change in the Arctic and how it affects the whole world

And the Arctic helps to regulate the world's temperature, so as more Arctic ice melts the warmer our world becomes. These are the facts: Melting ice speeds up climate change. ... When the Arctic ice melts, the oceans around it absorb more sunlight and heat up, making the world warmer as a result.

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