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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.

Comment by Dr. Krishna Kumari Challa on November 3, 2021 at 8:37am

 Ocean plastics could be converted to ship fuel

A team of researchers think that the plastic amassing in floating islands in the oceans could be used to power the ships that are sent to clean them up. In their paper published in Proceedings of the National Academy of Sciences, the group describes how ocean plastics could be converted to ship fuel.

Prior research has shown that millions of tons of plastics enter the ocean each year—some of it is ground into fragments and disperses, and some of it winds up in colossal garbage patches floating in remote parts of the ocean. Because of the danger that such plastics present to ocean life, some environmentalists have begun cleanup operations. Such operations typically involve sending a ship to a garbage patch, collecting as much as the ship will hold and then bringing it back to port for processing. In this new effort, the researchers suggest it would be far more efficient and greener to turn the plastic into fuel for both a processing machine and for uninterrupted operation of the ships.

The researchers note that the plastic in a garbage dump could be converted to a type of oil via hydrothermal liquefaction (HTL). In this process, the plastic is heated to 300–550 degrees Celsius at pressures 250 to 300 times that of sea-level conditions. The researchers have calculated that a ship carrying an HTL converter would be capable of producing enough oil to run the HTL converter and the ship's engine. Under their scenario, plastic collection booms would be permanently stationed at multiple sites around a large garbage patch, able to load the plastic it collects onto ships.

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The researchers acknowledge that burning the oil produced would release carbon into the atmosphere, but note that the amount emitted would still be less than that emitted by a ship burning conventional oil making trips back and forth to ports. They also note that HTL does produce a small amount of solid waste, which would have to be taken back to port, likely every few months—excess fuel produced by the HTL could be used for these trips.

 Elizabeth R. Belden et al, Thermodynamic feasibility of shipboard conversion of marine plastics to blue diesel for self-powered ocean cleanup, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2107250118

https://techxplore.com/news/2021-11-ocean-plastic-power-cleanup-shi...

Comment by Dr. Krishna Kumari Challa on November 2, 2021 at 8:36am

For the study, the research team applied a method called hyperalignment, which creates a common representational space for understanding how brain activity is similar between participants. The team used data obtained from three fMRI tasks with 14 graduate students who had known each other for at least two years. In two of the tasks, participants were presented with images of four other personally familiar graduate students and four other visually familiar persons, who were previously unknown. In the third task, participants watched parts of The Grand Budapest Hotel. The movie data, which is publicly available, was used to apply hyperalignment and align participants' brain responses into a common representational space. This allowed the researchers to use machine learning classifiers to predict what stimuli a participant was looking at based on the brain activity of the other participants.

The results showed that the identity of visually familiar and personally familiar faces was decoded with accuracy across the brain in areas that are mostly involved in visual processing of faces. Outside of the visual areas however, there was not a lot of decoding. For visually familiar identities, participants only knew what the stimuli looked like; they did not know who these people were or have any other information about them.

https://medicalxpress.com/news/2021-11-familiar-neural-code-brains....

Part 2

Comment by Dr. Krishna Kumari Challa on November 2, 2021 at 8:31am

Recognizing familiar faces relies on a neural code shared across brains

The ability to recognize familiar faces is fundamental to social interaction. This process provides visual information and activates social and personal knowledge about a person who is familiar. But how the brain processes this information across participants has long been a question. Distinct information about familiar faces is encoded in a neural code that is shared across brains, according to a new study published in the Proceedings of the National Academy of Sciences.

Within visual processing areas, researchers found that information about personally familiar and visually familiar faces is shared across the brains of people who have the same friends and acquaintances. The surprising part of these findings was that the shared information about personally familiar faces also extends to areas that are non-visual and important for social processing, suggesting that there is shared social information across brains.

In decoding personally familiar identities, the findings demonstrated that there was much more shared information across the brains of the participants. There was high decoding accuracy in four other areas outside of the visual system: the dorsal medial prefrontal cortex, which is known to be involved in social processing (processing other people's intentions and traits); the precuneus, an area which has been shown to be more active when processing personally familiar faces; the insula, which is known to be involved in emotional processing; and the temporal parietal junction, which plays an important role in social cognition and in representing the mental states of others (also known as the "theory of the mind").

This shared conceptual space for the personal knowledge of others allows us to communicate with people that we know in common.

Shared neural codes for visual and semantic information about familiar faces in a common representational space, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2110474118.

Part 1

Comment by Dr. Krishna Kumari Challa on November 1, 2021 at 10:54am

Using immunotherapeutics to tackle the threat of superbugs

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