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Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 10:24am

Part 2

investigated whether sidewinders' skin might also play a role in their unique movement style.

They focused on three species of sidewinders, all of them vipers, in residence at zoos: The sidewinder rattlesnake (Crotalus cerastes), found in the deserts of the Southwestern United States and northern Mexico; and the Saharan horned viper (Cerastes cerastes) and the Saharan sand viper (Cerastes vipera), both from the deserts of north Africa.

Skins shed from the sidewinders were collected and scanned with atomic force microscopy, a technique that provides resolution at the atomic level, on the order of fractions of a nanometer. For comparison, they also scanned snake skins shed from non-sidewinders.

As expected, the microscopy revealed tiny, head-to-tail pointing spikes on the skin of the non-sidewinders. Previous research had identified these micro spikes on a variety of other slithering snakes.

The current study, however, found that the skin of sidewinders is different. The two African sidewinders had micro pits on their bellies and no spikes. The skin of the sidewinder rattlesnake was also studded with tiny pits, along with a few, much smaller, spikes—although far fewer spikes than those of the slithering snakes.

The researchers created a mathematical model to test how these different structures affect frictional interactions with a surface. The model showed that head-to-tail pointing spikes enhance the speed and distance of forward undulation but are detrimental to sidewinding.

The model also showed that the uniform, non-directional structure of the round pits enhanced sidewinding, but was not as efficient as spikes for forward undulation.

The research provides snapshots at different points in time of convergent evolution—when different species independently evolve similar traits as a result of having to adapt to similar environments.

Jennifer M. Rieser el al., "Functional consequences of convergently evolved microscopic skin features on snake locomotion," PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.2018264118

https://phys.org/news/2021-02-physics-snakeskin-sidewinding.html?ut...

Comment by Dr. Krishna Kumari Challa on February 2, 2021 at 10:23am

Physics of snakeskin sheds light on sidewinding

Most snakes get from one place  to another by bending their bodies into S-shapes and slithering forward headfirst. A few species, however—found in the deserts of North America, Africa and the Middle East—have an odder way of getting around. Known as "sidewinders," these snakes lead with their mid-sections instead of their heads, slinking sideways across loose sand.

Scientists took a microscopic look at the skin of sidewinders to see if it plays a role in their unique method of movement. They discovered that sidewinders' bellies are studded with tiny pits and have few, if any, of the tiny spikes found on the bellies of other snakes.

The specialized locomotion of sidewinders evolved independently in different species in different parts of the world, suggesting that sidewinding is a good solution to a problem. Understanding how and why this example of convergent evolution works may allow us to adapt it for our own needs, such as building robots that can move in challenging environments.

This research bring together the physics of soft matter—flowable materials like sand—and organismal biology. The study shows how animals' surfaces interact with the flowable materials in their environments to get around. Insights from the research may lead to improvements in human technology.

Most snakes tend to keep their bellies largely in contact with the ground as they slide forward, bending their bodies from their heads to their tails. A sidewinder, however, lifts its midsection off the ground, shifting it in a sideways direction.

Previous studies have hypothesized that sidewinding may allow a snake to move better on sandy slopes.

Part 1

Comment by Dr. Krishna Kumari Challa on February 1, 2021 at 10:55am

Using science to explain the mysterious Dyatlov Pass Incident

Comment by Dr. Krishna Kumari Challa on February 1, 2021 at 10:04am

Mouse study: Gabapentin prevents harmful structural changes in spin...

Research led by The Ohio State University Wexner Medical Center and College of Medicine found that the widely prescribed pain-relief drug gabapentin can prevent harmful structural changes in the injured spinal cords of mice, and also block cardiovascular changes and immune suppression caused by spinal cord injury.

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Study provides insight into how the brain may have evolved

Researchers from The University of Western Australia have uncovered evidence of an important genetic step in the evolution of the brain. The finding highlights how genetic events that took place in our fish-like ancestors play crucial roles in human brain biology today.

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How vitamins, steroids and potential antivirals might affect SARS-C...

Evidence is emerging that vitamin D—and possibly vitamins K and A—might help combat COVID-19. A new study from the University of Bristol published in the journal of the German Chemical Society Angewandte Chemie has shown how they—and other antiviral drugs—might work. The research indicates that these dietary supplements and compounds could bind to the viral spike protein and so might reduce SARS-CoV-2 infectivity. In contrast, cholesterol may increase infectivity, which could explain why having high cholesterol is considered a risk factor for serious disease.

Comment by Dr. Krishna Kumari Challa on February 1, 2021 at 10:02am

Geological phenomenon widening the Atlantic Ocean

An upsurge of matter from deep beneath the Earth's crust could be pushing the continents of North and South America further apart from Europe and Africa, new research has found.

The plates attached to the Americas are moving apart from those attached to Europe and Africa by four centimetres per year. In between these continents lies the Mid-Atlantic Ridge, a site where new plates are formed and a dividing line between plates moving to the west and those moving to the east; beneath this ridge, material rises to replace the space left by the plates as they move apart.

Now a team of  seismologists  have found evidence of an upwelling in the mantle—the material between the Earth's crust and its core—from depths of more than 600 kilometres beneath the Mid Atlantic ridge, which could be pushing the plates from below, causing the continents to move further apart. Upwellings beneath ridges are typically thought to originate from much shallower depths of around 60 km.

The findings, published in the journal Nature provide a greater understanding of plate tectonics which causes many natural disasters around the world, including earthquakes, tsunamis and volcanic eruptions.

A thin mantle transition zone beneath the equatorial Mid-Atlantic Ridge, Nature (2021). DOI: 10.1038/s41586-020-03139-x , www.nature.com/articles/s41586-020-03139-x

https://phys.org/news/2021-01-geological-phenomenon-widening-atlant...

Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 1:11pm

The physics behind tumor growth

Researchers at Duke University have developed a predictive theory for tumor growth that approaches the subject from a new point of view. Rather than focusing on the biological mechanisms of cellular growth, the researchers instead use thermodynamics and the physical space the tumor is expanding into to predict its evolution from a single cell to a complex cancerous mass.

The results appeared Jan. 15 in the journal Biosystems.

The new work is based on the constructal law, which Bejan penned in 1996, that states that for a system to survive, it must evolve to increase its access to flow. For example, the human vascular system has evolved to provide blood flow through a network of a few large arteries and many small capillaries. River systems, tree branches and modern highway and road networks all reflect the same forces at work.

In the paper researchers demonstrate how a tumor’s growth and internal reorganization as it grows are directly tied to its need to create greater access to flowing nutrients as well as conduits for removing refuse. They use these insights to predict the growth of cell clusters as a function of structure, and also to predict the critical cluster sizes that mark the transitions from one distinct configuration to the next.

To validate their theory, the researchers compared their predictions with the measurements of several independent studies of cancerous and non-cancerous tumor growth patterns. The results show that their work provides a unifying perspective on the growth of cell clusters on the smallest scales as well as the large-scale dynamics of proliferating cells as described in phenomenological models.

As the tumor grows, the flow systems get large enough to create visible currents through the vascularization of the tumor. The new theory reveals the physics behind these sorts of dramatic transitions and predict when they should happen.

https://pratt.duke.edu/about/news/physics-tumor-growth

“Cell and Extracellular Matrix Growth Theory and its Implications for Tumorigenesis,” T.J. Sauer, E. Samei, A. Bejan. Biosystems, Jan. 15, 2021. DOI: 10.1016/j.biosystems.2020.104331

Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 1:07pm

Wireless linkage of brains may soon go to human testing

Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 12:26pm

A protein that can melt tumors discovered at Vanderbilt
 For the second time, cancer researchers at Vanderbilt have discovered a protein that when genetically manipulated to impede it from interacting with a gene responsible for cancer genesis effectively melts tumors in days. The article, MYC regulates ribosome biogenesis and mitochondrial gene expression programs through interaction with Host Cell Factor-1, was published in the journal eLIFE on Jan. 8.

https://researchnews.cc/news/4842/A-protein-that-can-melt-tumors-di...

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Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 12:19pm

Scientists use a novel ink to 3D print ‘bone’ with living cells

Comment by Dr. Krishna Kumari Challa on January 31, 2021 at 12:15pm

Major discovery helps explain coral bleaching

Corals, like all animals, must eat to live. The problem is that most corals grow in tropical waters that are poor in nutrients, sort of like ocean deserts; it’s this lack of nutrients that makes the water around coral reefs so crystal clear. Because food is not readily available, corals have developed a remarkable feeding mechanism that involves a symbiotic relationship with single-celled algae. These algae grow inside the corals, using the coral tissue as shelter and absorbing the CO2 that the corals produce. In exchange, the algae provide corals with nutrients they produce through photosynthesis. These algae contain a variety of pigments, which give the coral reefs the colors they’re known for.

Over the past 35 years, tropical oceans have experienced multiple major heat waves. Scientists have observed that during these episodes, the algae – stressed by the warmer temperatures – release compounds that are toxic to the coral, prompting the coral to expel the algae from their tissue. That means the corals lose their color and their primary food source, and then begin to starve. This is the process of coral bleaching. And it has been occurring more and more frequently, threatening the survival of many reefs, including Australia’s Great Barrier Reef. Bleached corals do not necessarily die; their symbiotic algae population can be reestablished if the conditions around a reef return to normal. But if the heat persists, or is aggravated by other factors like pollution, the coral becomes too weak to survive.

In a paper published in the prestigious PNAS on 26 January, an international team of scientists  reveals a major discovery related to how the symbiotic relationship ends between the coral and algae.  Theyshowed for the first time that the coral starts to suffer from hunger long before the algae are expelled. The algae apparently stop providing sufficient nutrients while they are still inside the coral tissue.

Scientists already knew that ocean warming is the main factor causing the symbiotic relationship to break down. But what the team now discovered was that the coral is already in a stressed state and lacking nutrients even before the algae begin releasing toxic compounds. The roots of the problem are much deeper than the scientists thought, and they involve an early breakdown of the metabolic exchanges in these fascinating organisms.

Based on these findings, researchers can determine which environmental conditions other than temperature (such as water quality) stress the corals in a reef, and use this information to predict whether the reef will bleach.

"Heat stress destabilizes symbiotic nutrient cycling in corals". Nils Rädecker, Claudia Pogoreutz, Hagen M. Gegner, Anny Cardenas, Florian Roth, Jeremy Bougoure, Paul Guagliardo, Christian Wild, Mathieu Pernice, Jean-Baptiste Raina, Anders Meibom, Christian R. Voolstra. PNAS, 26 January 2021.

https://actu.epfl.ch/news/major-discovery-helps-explain-coral-bleac...

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