Comment

Comment by Dr. Krishna Kumari Challa on July 12, 2024 at 9:21am

The researchers prepared human nasal tissue in the lab, growing it to resemble the surfaces of the human respiratory tract, then monitored gene expression changes over a 14-day 'infection.'
They found very limited production of inflammation molecules over time, which normally would be produced within hours of bacteria infecting human cells.

Researchers then applied both live and dead Haemophilus influenzae, showing the dead bacteria caused a fast production of the inflammation makers, while live bacteria prevented this.
This proved that the bacteria can actively reduce the human immune response.
If local immunity drops, for example during a viral infection, the bacteria may be able to 'take over' and cause a more severe infection.

 PLOS Pathogens (2024). journals.plos.org/plospathogen … journal.ppat.1012282

Part 2

Comment by Dr. Krishna Kumari Challa on July 12, 2024 at 9:19am

Respiratory bacteria 'turn off' immune system to survive, study finds

Researchers have identified how a common bacterium is able to manipulate the human immune system during respiratory infections and cause persistent illness. The research was published in PLOS Pathogens.

This study found the virulence mechanisms of Haemophilus influenzae, a bacterium that plays a significant role in worsening respiratory tract infections.

These bacteria are especially damaging to vulnerable groups, such as those with cystic fibrosis, asthma, the elderly, and Indigenous communities.

In some conditions, such as asthma and chronic obstructive pulmonary disease,

they can drastically worsen symptoms.

This research shows the bacterium persists by essentially turning off the body's immune responses, inducing a state of tolerance in human respiratory tissues.

Part 1

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 10:24am

Some environmental toxicants linked to depressive symptoms

Certain categories of environmental toxicants are associated with depressive symptoms, according to a study published online July 3 in JAMA Network Open.

Researchers  screened and assessed the associations between potential environmental toxicants and depressive symptoms among 3,427 participants from the 2013 to 2014 and 2015 to 2016 waves of the National Health and Nutrition Examination Survey. Exposures were assessed for 62 toxicants in 10 categories; the association with depression scores, measured by the 9-item Patient Health Questionnaire (PHQ-9), was examined.

The researchers identified associations between 27 chemical compounds or metals in six of 10 categories of environmental toxicants and the prevalence of depressive symptoms, including the volatile organic compound metabolites N-acetyl-S-(2 hydroxy-3-butenyl)-L-cysteine and total nicotine equivalent-2 (odds ratios, 1.74 and 1.42, respectively).

Compared with women and older individuals, men and younger individuals seemed more vulnerable to environmental toxicants. Overall, 5–19 percent of the associations were mediated by peripheral white blood cell count.

"This research highlights the significance of preventing and regulating important environmental toxicants to gain fresh insights into preventing and potentially treating depression," the authors write in their paper.

Jianhui Guo et al, Environmental Toxicant Exposure and Depressive Symptoms, JAMA Network Open (2024). DOI: 10.1001/jamanetworkopen.2024.20259

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 10:20am

Air pollution may affect lupus risk

New research published in Arthritis & Rheumatology indicates that chronic exposure to air pollutants may increase the risk of developing lupus, an autoimmune disease that affects multiple organs.

For the study, investigators analyzed data on 459,815 participants from the UK Biobank. A total of 399 lupus cases were identified during a median follow-up of 11.77 years. Air pollutant exposure was linked with a greater likelihood of developing lupus. Individuals with a high genetic risk and high air pollution exposure had the highest risk of developing lupus compared with those with low genetic risk and low air pollution exposure.

This study provides crucial insights into the air pollution contributing to autoimmune diseases. The findings can inform the development of stricter air quality regulations to mitigate exposure to harmful pollutants, thereby reducing the risk of lupus.

Air pollution, genetic susceptibility and risk of incident Systemic lupus erythematosus: A prospective cohort study, Arthritis & Rheumatology (2024). DOI: 10.1002/art.42929

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Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 10:01am

The geometry of life: Physicists determine what controls biofilm growth

This is physics helping biology.

From plaque sticking to teeth to scum on a pond, biofilms can be found nearly everywhere. These colonies of bacteria grow on implanted medical devices, our skin, contact lenses, and in our guts and lungs. They can be found in sewers and drainage systems, on the surface of plants, and even in the ocean.

Some research says that 80% of infections in human bodies can be attributed to the bacteria growing in biofilms.

The paper, "The biophysical basis of bacterial colony growth," was published in Nature Physics this week, and it shows that the fitness of a  biofilm- its ability to grow, expand, and absorb nutrients from the medium or the substrate—is largely impacted by the contact angle that the biofilm's edge makes with the substrate. The study also found that this geometry has a bigger influence on fitness than anything else, including the rate at which the cells can reproduce.

Understanding how biofilms grow—and what factors contribute to their growth rate—could lead to critical insights on controlling them, with applications for human health, like slowing the spread of infection or creating cleaner surfaces.

 Aawaz R. Pokhrel et al, The biophysical basis of bacterial colony growth, Nature Physics (2024). DOI: 10.1038/s41567-024-02572-3

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 9:54am

Subsurface of fingernails found to have precise tactile localization

Researchers found that humans have a surprisingly precise degree of tactile localization beneath their fingernails. In his study, published in the Proceedings of the Royal Society B, they tested how well volunteers could pinpoint the part of their fingernail being stimulated and outlines possible reasons.

Humans, like other primates, have nails on the ends of their fingers rather than claws—an evolutionary development that has not been explained. In this new effort, researchers investigated the sensitivity of the skin below the fingernails to learn more about how they were used by our ancestors.

The human fingernail does not have any nerves; thus, it cannot sense touch, pressure, heat, cold or other environmental characteristics. But there is skin beneath the fingernail that is capable of sensations, as evidenced by people who accidentally hit their thumb with a hammer or lose a nail.

To learn more about the sensitivity of the subsurface of the fingernail, the researchers recruited 38 adult volunteers. Each agreed to have their fingernails poked while they indicated on a photograph of a fingernail where they thought their fingernail was being touched. In the experiments, half of the volunteers had their nails touched by a stick, the other half by a filament. Only the thumb and middle finger were tested.

The study found that humans have highly precise localization in their nails—they can tell clearly which part of their nail is being touched. He suggests that this is due to mechanoreceptors called Pacinian corpuscles, buried in the skin beneath the nails. He notes that it is the same mechanism that allows blind people to localize touch using a cane. Pacinian corpuscles are able to detect small amounts of vibration, which happens when a slight impact occurs between a foreign object and a fingernail.

Why did humans develop fingernails instead of claws?  Why the skin beneath the nails is so sensitive? Researchers theorize that they likely served a sensorimotor function, giving humans more information about whatever their hands encounter.

Matthew R. Longo, Precise tactile localization on the human fingernail, Proceedings of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rspb.2024.1200

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 9:35am

The changing fire science

A new paper on the many ways wildfires affect people and the planet makes clear that as fires become more intense and frequent, the urgency for effective and proactive fire science grows. By addressing these challenges, the fire research community aims to better protect our planet and its inhabitants.

The paper appears in the Zenodo research repository.

Fire is a natural part of life on Earth, sustaining healthy and balanced ecosystems worldwide. But human activity and a changing climate are rapidly shifting both the frequency and severity of wildfire events, creating new risks to human and environmental health.

Recently, a group of scientists from 14 countries and across several disciplines—physical and social sciences, mathematics, statistics, remote sensing, fire communication and art, operational fire science, and fire management—gathered to discuss rapid changes in fire regimes and identify pathways to address these challenges.

The experts identified three grand challenges for fire science in the coming decades: understanding the role of fire in the carbon cycle, fire and extreme events, and the role of humans in fire.

If we want to improve the assessment of future fire impacts on people and the planet, we need to start with a better understanding of how climate, land cover changes, and human land management practices drive fire distribution and severity in the coming decades, the scientists say.

To address the grand challenges, the scientists identified three pressing research priorities: understanding the net carbon balance of fire, developing rapid response tools for wildfire events, and understanding fire's impact on society, especially marginalized and underrepresented populations.

A main goal of the white paper is to be able to improve fire modeling, predictability, and mitigation on both regional and global scales.

As fire events become more intense and frequent, the urgency for effective and proactive fire science grows. Scientists are taking steps  to address these challenges collectively, as a unified fire research community, to better protect our planet and its inhabitants.

Douglas S Hamilton et al, Igniting Progress: Outcomes from the FLARE workshop and three challenges for the future of transdisciplinary fire science, Zenodo (2024). DOI: 10.5281/zenodo.12634067

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 9:16am

Researchers discover a new defense mechanism in bacteria

When confronted with an antibiotic, toxic substance, or other source of considerable stress, bacteria are able to activate a defense mechanism using cell-to-cell communication to "warn" unaffected bacteria, which can then anticipate, shield themselves and spread the warning signal.

This mechanism has just been described for the first time by a team of scientists .

It paves the way for the development of new, more effective antibiotic treatments that can target this bacterial communication system. The work appears in Nature Communications.

When they perceive a source of stress, bacteria spring into action, inducing changes in the expression of certain genes and their physiological properties to make them less vulnerable to the detected lethal substance. They also produce small alarmone proteins on their surface in order to contact and activate random neighboring bacteria.

Unstressed bacteria can only change state in the presence of a sufficient amount of alarmones. Thus, only a source of stress perceived by sufficient bacteria can trigger propagation of this activation.

The mechanism offers several advantages: It limits the unnecessary use of energy and enables a rapid and coordinated response in the population. Because activation is gradual, it creates diversity in the population over time, thus increasing the bacteria's chances of survival.

These findings were established using a dozen different families of antibiotics on populations of Streptococcus pneumoniae, the bacteria that causes pneumococcal infections.

 Pneumococcal competence is a populational health sensor driving multilevel heterogeneity in response to antibiotics, Nature Communications (2024). DOI: 10.1038/s41467-024-49853-2

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 9:06am

Shocks which hit the Earth head-on, rather than at an angle, are thought to induce stronger geomagnetically induced currents, because they compress the magnetic field more. The scientists investigated how geomagnetically induced currents are affected by shocks at different angles and times of day.

Scientists found that more frontal shocks cause higher peaks in geomagnetically induced currents both immediately after the shock and during the following substorm. Particularly intense peaks took place around magnetic midnight, when the north pole would have been between the sun and Mäntsälä. Localized substorms at this time also cause striking auroral brightening.

Moderate currents occur shortly after the perturbation impact when Mäntsälä is around dusk local time, whereas more intense currents occur around midnight local time. 

Because the angles of these shocks can be predicted up to two hours before impact, this information could allow us to set in place protections for electricity grids and other vulnerable infrastructure before the strongest and most head-on shocks strike.

One thing power infrastructure operators could do to safeguard their equipment is to manage a few specific electric circuits when a shock alert is issued. This would prevent geomagnetically induced currents reducing the lifetime of the equipment.

However, the scientists didn't find strong correlations between the angle of a shock and the time it takes for it to hit and then induce a current. This may be because more recordings of currents at different latitudes are needed to investigate this aspect. Current data was collected only at a particular location, namely the Mäntsälä natural gas pipeline system.

Although Mäntsälä is at a critical location, it does not provide a worldwide picture.

First direct observations of interplanetary shock impact angle effects on actual geomagnetically induced currents: The case of the Finnish natural gas pipeline system, Frontiers in Astronomy and Space Sciences (2024). DOI: 10.3389/fspas.2024.1392697

Part 2

Comment by Dr. Krishna Kumari Challa on July 11, 2024 at 9:03am

Auroras caused by head-on blows to Earth's magnetic field could damage critical infrastructure, scientists say

Auroras are beautiful colourful lights that catch our imagination. Poets write poems, artists, including me, create art works based on them,  writers weave stories around them.

They have inspired myths and portents for millennia—but only now, with modern technology dependent on electricity, are we appreciating their true power.

The same forces which cause auroras also cause currents that can damage infrastructure which conducts electricity, like pipelines.

Now scientists writing in Frontiers in Astronomy and Space Sciences have demonstrated that the impact angle of interplanetary shocks is key to the currents' strength, offering an opportunity to forecast dangerous shocks and shield critical infrastructure.

Auroras and geomagnetically induced currents are caused by similar space weather drivers. 

The aurora is a visual warning that indicates that electric currents in space can generate these geomagnetically-induced currents on the ground.

The auroral region can greatly expand during severe geomagnetic storms. Usually, its southernmost boundary is around latitudes of 70 degrees, but during extreme events it can go down to 40 degrees or even further, which certainly occurred during the May 2024 storm—the most severe storm in the past two decades.

Auroras are caused by two processes: either particles ejected from the sun reach Earth's magnetic field and cause a geomagnetic storm, or interplanetary shocks compress Earth's magnetic field.

These shocks also generate geomagnetically induced currents, which can damage infrastructure that conducts electricity. More powerful interplanetary shocks mean more powerful currents and auroras—but frequent, less powerful shocks could also do damage.

The most intense deleterious effects on power infrastructure occurred in March 1989 following a severe geomagnetic storm—the Hydro-Quebec system in Canada was shut down for nearly nine hours, leaving millions of people with no electricity.

But weaker, more frequent events such as interplanetary shocks can pose threats to ground conductors over time.  Recent research work shows that considerable geoelectric currents occur quite frequently after shocks, and they deserve attention.

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