Comment

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 11:18am

Iron was life's 'primeval' metal, say scientists

Every living organism uses tiny quantities of metals to carry out biological functions, including breathing, transcribing DNA, turning food into energy, or any number of essential life processes.

Life has used metals in this way since single-celled organisms floated in Earth's earliest oceans. Nearly half of the enzymes—proteins that carry out chemical reactions in cells—within organisms require metals, many of which are transition metals named for the space they occupy in the periodic table.

Now, a team of scientists argue that iron was life's earliest, and sole, transition metal. Their study, titled "Iron: Life's primeval transition metal," is published in the Proceedings of the National Academy of Sciences.

They argue that life only relied on metals that it could interact with, and the iron-rich early ocean would make other transition metals essentially invisible.

Early oceans were rich in iron—specifically, an ion of iron called Fe(II). Fe(II) can be readily dissolved in water and would have been the primary metal found in oceans during the Archean Eon, a geologic time period that began about 4 billion years ago and ended about 2.5 billion years ago.

The end of the Archean Eon was marked by something called the Great Oxygenation Event. At this time, life evolved the ability to perform oxygen-producing photosynthesis. Over the next billion years, Earth's ocean transformed from an iron-rich, anoxic sea to today's oxygenated body of water, according to the researchers. This also oxidized Fe(II) into Fe(III), rendering it insoluble.

Geologists knew of iron's ubiquity on Earth during this time, it wasn't until they began talking with Valentine that they realized how great an impact iron might have had on early life.

Life, in the face of orders of magnitude more iron than other metals, couldn't know to evolve toward such a sophisticated way of managing them. The fall of the abundance of iron forced life to manage these other metals to survive, but that also enabled new functions and the diversity of life we have today.

Johnson, Jena E., Iron: Life's primeval transition metal, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2318692121. doi.org/10.1073/pnas.2318692121

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Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 11:09am

There are several reasons why most cities receive more rainfall than their rural neighbors.
One key factor is the presence of tall buildings, which block or slow down wind speeds. This leads to a convergence of air toward the city center.
The buildings further enhance this convergence by slowing the winds, resulting in a stronger upward motion of air. This upward motion promotes the condensation of water vapor and cloud formation, which are critical conditions for producing rainfall and precipitation.
Researchers found that population has the largest correlation with urban precipitation anomalies compared to other environmental and urbanization factors. This is because larger populations typically create denser and taller urban areas, along with more greenhouse gas emissions, and therefore more pronounced heat.
This phenomenon has implications for all cities heading into a future of climate change.
the increased chances of rainfall in cities combined with the impervious surfaces that make up their urban environments can be a recipe for flash flooding.

Niyogi, Dev, Global scale assessment of urban precipitation anomalies, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2311496121. doi.org/10.1073/pnas.2311496121

Part2

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 11:07am

Global study shows that most cities receive more rainfall than surrounding rural areas

The effect of urbanization on temperature is relatively well-known: cities are often measurably warmer than their surrounding rural areas. This is called the urban heat island effect. What fewer people know is that the urban heat island has a twin counterpart with similarly important consequences: the urban precipitation anomaly, where the presence of urban development measurably affects the amount of rainfall in an area.

In a study published in Proceedings of the National Academy of Sciences, researchers looked for evidence of precipitation anomalies in 1,056 cities across the globe and found that more than 60% of those cities receive more precipitation than their surrounding rural areas.

In some cases, the difference can be significant. For instance, researchers found that Houston, on average, will receive almost 5 inches more rain per year than its surrounding rural areas.

This could have wide-ranging implications, the most serious of which is worsened flash flooding in densely built urban areas.

Variation in urban rainfall is something scientists have known about for several decades, but never at a global scale. Previous studies only looked at certain cities and storm cases.

Urban areas tend to take rain from one location and concentrate it in another, much like a sponge that is being squeezed. If you were to pinch one part of the sponge, you would have water coming down more forcefully from one side. The amount of water you have in the sponge is the same, but because now you have that dynamic sort of squeezing the atmosphere, you have more ability to take the water out from that location.

Although it's less common, some urban areas actually receive less rainfall than their surrounding rural counterparts. This typically occurs in cities situated in valleys and lowlands, where precipitation patterns are controlled by nearby mountains. The cities where this is most pronounced include Seattle, Washington; Kyoto, Japan; and Jakarta, Indonesia.

Part1

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:56am

To understand that critical part of the process, the research team turned to colloidal crystals—particles that are about 10,000 times larger than atoms and spontaneously form a crystal structure at high concentrations. These crystals are used to mimic atomic systems because they have the same structures, undergo the same phase transitions, and possess the same types of defects. Colloidal crystals, however, are very soft—even 100,000 times softer than Jell-O.

The researchers grew these colloidal crystals composed of millions of particles and observed each particle using a confocal optical microscope. When they applied a strain to these crystals, they could measure the motion of each and every particle.

Surprisingly, these colloidal crystals experience significant work hardening—even more strongly than any other material. In fact, when the difference in particle size is taken into account, these ultra-soft materials become much stronger than most metals.
It is the first time that work hardening has been observed in colloidal crystals; it reveals that the process is governed primarily by the geometry of the particles and the defects. The crystals became stronger because of the dislocation defects, how they interact and entangle with one another.

These observations reveal the universal mechanisms of work hardening which will also apply more generally to all materials.

Seongsoo Kim et al, Work hardening in colloidal crystals, Nature (2024). DOI: 10.1038/s41586-024-07453-6

Part 2

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Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:54am

Why do materials get stronger when they are deformed? Research sheds light on universal mechanisms of work hardening

The earliest blacksmiths in the Bronze and Iron Ages figured out that when they deformed metal through bending or hammering, it became stronger. This process, known as work or strain hardening, is still used widely in metallurgy and manufacturing today to increase the strength of everything from car frames to overhead power wires. But materials scientists have never been able to watch this essential process unfold in real time—until now.

A team of scientists  have observed, for the first time, the detailed mechanisms driving the fundamental process of work hardening.

It's been impossible to observe work hardening in metals in real time because the atomic structures can only be observed through an electron microscope. Researchers can compare the structure before and after deformation but have had only a limited view into what happens during the process. Previous research has revealed that imperfections in the structure, known as dislocations, form a network of defects which cause the work hardening.

Part 1

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:35am

Nanoscale silver exhibits intrinsic self-healing abilities without external intervention

As an innovative concept in materials science and engineering, the inspiration for self-healing materials comes from living organisms that have the innate ability to self-heal. Along this line, the search for self-healing materials has been generally focused on "soft" materials like polymers and hydrogels. For solid-state metals, one may intuitively imagine that any form of self-healing will be much more difficult to achieve.

While a few past studies have showcased the self-healing behavior in metals that more or less requires the assistance of external triggers (e.g., by heating, mechanical stimulus, or electron beam irradiation), whether the autonomous self-healing can occur in metal solids without any external intervention remains a scientific curiosity.

Now in a new study published in Matter, researchers from the Institute of Physics (IOP) of the Chinese Academy of Sciences have discovered that such an intrinsic and autonomous self-healing phenomenon can occur in nanoscale silver (Ag).

This study, which combines advanced in-situ transmission electron microscopy (TEM) with molecular dynamics (MD) simulations, reveals that nanoscale Ag can autonomously repair itself from structural damage, such as nanocracks and nanopores, without external intervention.

This remarkable ability is observed not only at room temperature but also at frigid temperatures as low as 173 K. Notably, over the same damaging area, the repeated reversible self-healing cycles can also be achieved with the same level of efficiency.

Jianlin Wang et al, Direct observation of autonomous self-healing in silver, Matter (2024). DOI: 10.1016/j.matt.2024.07.009

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 10:03am

A patient tests positive for bird flu despite no known exposure to animals

A hospitalized patient in Missouri was infected with bird flu despite having had no known contact with dairy cows or other animals associated with an ongoing outbreak, health officials said last week.

The person tested positive for influenza A, and CDC officials later confirmed it to be bird flu. The person received antiviral medication and has since recovered and gone home, health officials said. It's not clear whether the hospitalization was caused by the bird flu infection or the person's existing health conditions.

The case raises questions about how the person was exposed to the virus. All the previous U.S. infections were among people who worked around cows and poultry.

The investigation is continuing, officials said.

It's the first case detected through routine influenza surveillance rather than through targeted efforts to identify people infected with bird flu through exposure to infected cows and poultry, officials said.

Source: News agencies

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 9:52am

Newly identified biomarkers could reveal risk factors for sudden infant death syndrome

Researchers  are getting closer to being able to predict sudden infant death syndrome, or SIDS.

In a study appearing in JAMA Pediatrics, they have identified signals in the metabolic system of infants who died of SIDS.

This study suggests that metabolic factors may play a crucial role in SIDS. These patterns could help identify children at higher risk, potentially saving lives in the future.

Each year about 1,300 infants under the age of 1 die from SIDS, and researchers still aren't sure what causes these unexpected deaths. What they do know is that there are likely multiple factors that play a role, including inadequate prenatal care, smoking and alcohol use during pregnancy, structural racism and air pollution. Male babies have a higher rate of SIDS than girls.

Researchers are turning to biology to look for a cause of SIDS that can be screened for at birth or targeted with medication. Investigators in this study knew from previous research that the metabolic system—how bodies process and store energy—might play a part in SIDS. They decided to examine the role of the metabolic system more closely, and compare metabolic data taken from infants as part of a routine newborn screening.

They compared the data of infants who eventually died from SIDS with similar infants who lived.

In the 354 infants who died from SIDS, they found that there were some metabolic biomarkers that may be associated with increased risk. For example, infants with lower levels of C-3 and elevated levels of C-14OH appear to have a higher risk of dying from SIDS. These findings are in line with previous research that has found an association between enzymes of fatty acid oxidation, like these, and SIDS.

The scientists also found several other biomarkers that--when elevated--seemed to lead to a reduced risk of SIDS.

JAMA Pediatrics (2024). jamanetwork.com/journals/jamap … pediatrics.2024.3033

Comment by Dr. Krishna Kumari Challa on September 10, 2024 at 9:45am

Scientists provided evidence for long-standing wave amplification theory

Physicists  have tested and provided evidence for  a 50-year-old theory for the first time using electro-magnetic waves. They have shown that the energy of waves can be increased by bouncing "twisted waves"—those with angular momentum—off of an object which is rotating in a specific way.

This is known as the "Zel'dovich effect," named after Soviet physicist Yakov Zel'dovich who developed a theory based on this idea in the 1970s. Until now, it was believed to be unobservable with electromagnetic fields.

The Zel'dovich effect works on the principle that waves with angular momentum, that would usually be absorbed by an object, actually become amplified by that object instead, if it is rotating at a fast enough angular velocity. In this case, the object is an aluminum cylinder and it must rotate faster than the frequency of the incoming radiation.

Although physicists successfully tested this theory in sound waves a few years ago, but until this most recent experiment it hadn't been proven with electromagnetic waves. Using relatively simple equipment—a resonant circuit interacting with a spinning metal cylinder—and by creating the specific conditions required, they have now been able to do this.

M. C. Braidotti et al, Amplification of electromagnetic fields by a rotating body, Nature Communications (2024). DOI: 10.1038/s41467-024-49689-w

Comment by Dr. Krishna Kumari Challa on September 9, 2024 at 8:33am

Newly discovered antibody protects against all COVID-19 variants

Researchers have discovered an antibody able to neutralize all known variants of SARS-CoV-2, the virus that causes COVID-19, as well as distantly related SARS-like coronaviruses that infect other animals.

As part of a new study on hybrid immunity to the virus, the large, multi-institution research team discovered and isolated a broadly neutralizing plasma antibody, called SC27, from a single patient. Using technology developed over several years of research into antibody response, the research team obtained the exact molecular sequence of the antibody, opening the possibility of manufacturing it on a larger scale for future treatments.

The discovery of SC27, and other antibodies like it in the future, will help us better protect the population against current and future COVID variants.

Protective antibodies bind to a part of the virus called the spike protein that acts as an anchor point for the virus to attach to and infect the cells in the body. By blocking the spike protein, the antibodies prevent this interaction and, therefore, also prevent infection.

Scientists after verifying  the properties of SC27 found that it recognized the different characteristics of the spike proteins in the many COVID variants.

In addition to the discovery of this antibody, the research found that hybrid immunity—a combination of both infection and vaccination—offers increased antibody-based protection against future exposure compared with infection or vaccination alone.

The researchers have filed a patent application for SC27.

William N. Voss et al, Hybrid immunity to SARS-CoV-2 arises from serological recall of IgG antibodies distinctly imprinted by infection or vaccination, Cell Reports Medicine (2024). DOI: 10.1016/j.xcrm.2024.101668

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