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Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:30am

So what would it take to warn people of a coming landslide? You would need a prediction for earthquakes and rainfall, in addition to a perfect knowledge of the slope-forming geomaterial.

Under our feet, geomaterials may include multiple, entangled layers of various kinds of rocks and particulate materials, such as sand, silt and clays. Their strength varies from a factor of one to 1,000, and their spatial distribution dictates where the slope is likely to fail.

To accurately assess the stability of the slope, a three-dimensional mapping of these materials and their strengths is needed. No sensor can provide this information, so geologists and geotechnical engineers must deal with partial information obtained at a few selected locations and extrapolate this data to the rest of the slope.

The weakest link of the chain—such as an existing fracture in a rock mass—is easily missed. This is an inevitable source of uncertainty when trying to predict how much material might slip. We do know that the larger the volume of a landslide, the farther its runout distance. But it's hard to gauge the exact size of a landslide, making predictions of runout distances and safe zones uncertain. The question of "when will a landslide will occur" is also uncertain. Mechanical analysis enables us to estimate the vulnerability of a slope in a particular scenario, including earthquake magnitude and distribution of groundwater. But predicting if and when these triggers will happen is as "easy" as predicting the weather and seismic activity—a difficult task. Unfortunately, all the money in the world can't buy accurate landslide predictions—especially in remote parts of the world.

https://theconversation.com/what-causes-landslides-can-we-predict-t...

Part 2

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:29am

What causes landslides? 

Landslides happen when the pull from gravity exceeds the strength of the geomaterial forming the slope of a hill or mountain. Geomaterials can be as varied as rocks, sand, silt and clays.

Then, part of this slope starts sliding downhill. Depending on where the slope fails, the material sliding down can be just a few cubic meters or a few million cubic meters in volume.

Why do slopes fail? Most natural landslides are triggered by earthquakes or rainfall, or a combination of both.

Earthquakes shake the ground, stress it and weaken it over time. Rainwater can seep through the ground and soak it—the ground is often porous like a sponge—and add weight to the slope. This is why PNG is so prone to landslides, as it sits on an active fault and is subjected to heavy rainfalls.

Another adverse effect of water is erosion: the constant action of waves undercuts coastal slopes, causing them to fail. Groundwater can also dissolve rocks within slopes.

Humans can (and do) cause landslides in several ways, too. For example, deforestation has a negative impact on slope stability, as tree roots naturally reinforce the ground and drain water out. Also, mine blasts produce small earthquake-like ground vibrations that shake slopes nearby.

It's very difficult to predict and mitigate landslide risk effectively.

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:24am

Study suggests 'biodegradable' teabags don't readily deteriorate in the environment

Some teabags manufactured using plastic alternatives do not degrade in soil and have the potential to harm terrestrial species, a new study has shown.

The research looked at commonly available teabags made using three different compositions of polylactic acid (PLA), which is derived from sources such as corn starch or sugar cane.

The teabags were buried in soil for seven months, and a range of techniques were then used to assess whether—and to what extent—they had deteriorated.

The results showed that teabags made solely from PLA remained completely intact. However, the two types of teabags made from a combination of cellulose and PLA broke down into smaller pieces, losing between 60% and 80% of their overall mass and with the PLA component remaining.

The study also examined the impacts of the disks cut from the teabags on a species of earthworm, Eisenia fetida, which has a critical role in soil nutrient turnover as it consumes organic matter.

Researchers found that being exposed to three different concentrations of teabag disks—equivalent to the mass of half, one and two teabags—resulted in up to 15% greater mortality, while some concentrations of PLA had a detrimental effect on earthworm reproduction.

Writing in the journal Science of the Total Environment, the study's authors highlight the need for accurate disposal information to be clearly displayed on product packaging.

Only one of the manufacturers whose products were chosen for the study indicated on the packaging that the teabags were not home compostable.

This could lead to them ending up in soil, while there is also high potential for consumer confusion about the meaning of terms such as plant-based or biodegradable, emphasizing the need for clear guidance on appropriate disposal.

W. Courtene-Jones et al, Deterioration of bio-based polylactic acid plastic teabags under environmental conditions and their associated effects on earthworms, Science of The Total Environment (2024). DOI: 10.1016/j.scitotenv.2024.172806

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:17am

Because nanoparticles are so small, it's impossible to see them using conventional microscopes. Therefore, the researchers tagged the nanoparticles with either fluorescence or europium, a rare metal that is not naturally present in the human body.

They  found that the nanoplastics can cross blood vessel walls, and that they accumulated to relatively high levels in the heart, liver and kidneys. Some nanoplastics were excreted by the kidneys.

Interestingly, the researchers also found nanoplastics in the avascular heart cushions: a type of heart tissue without blood vessels. They think the nanoplastics might enter the heart through the fenestrate. These are small openings within the developing heart tissue that play a role in the formation and remodeling of the heart's structure during development. These fenestrations are temporary structures that typically close as the heart matures.

Now we know how these nanoplastics spread, we can start investigating the health risks.

There is already research linking nanoparticles to a higher risk of heart attacks and strokes. Especially during the developmental stage, nanoparticles could potentially be quite dangerous.

We now understand that we shouldn't administer nanomedicines to pregnant women indiscriminately, as there is a risk that nanoparticles could reach and affect the developing organs of their babies.

Meiru Wang et al, The biodistribution of polystyrene nanoparticles administered intravenously in the chicken embryo, Environment International (2024). DOI: 10.1016/j.envint.2024.108723

Part 2

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:13am

Biologists find nanoplastics in developing chicken heart

Nanoplastics can accumulate in developing hearts, according to a study published in Environment International by biologists. Research on chicken embryos sheds new light on how these tiny plastic particles pose a threat to our health.

Disposable cups, plastic bags and packaging material: Plastics exposed to the elements become brittle over time, and start shedding small particles from their surface into nature. These particles can be as tiny as only a few nanometers in size.

You can find these nanoplastics everywhere now: in the sea, in the soil, in the food chain… and in our blood.   They have even been found in human placentas.

This made scientists think: What happens when those nanoplastics end up in the blood of the embryo?

During an earlier study, investigators discovered that a high concentration of nanoplastics can cause malformations in the heart, eyes, and nervous systems of chicken embryos. But for a more complete understanding of the toxicity of nanoplastics, they first need more information about how they spread from the blood throughout the rest of the body.

That knowledge will also be informative in nanomedicine, where scientists aim to use nanoplastics (and other nanoparticles) as vehicles for drug-delivery.

Researchers administered polystyrene nanoparticles directly into the bloodstream of chicken embryos. Chicken embryos are a widely used model for research on growth and development. In mammals, it's much more challenging to administer substances or take measurements because their embryos develop inside the mother's womb.

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 9:06am

Green chemistry: Producing gold nano-particles (and hydrogen) in water without the need for toxic chemicals

In a surprise discovery, Flinders University nanotechnology researchers have produced a range of different types of gold nanoparticles by adjusting water flow in the novel vortex fluidic device—without the need for toxic chemicals. The article, "Nanogold Foundry Involving High-Shear-Mediated Photocontact Electri...," has been published in Small Science.

The green chemistry lab work on nano gold formation also led to the discovery of a contact electrification reaction in water in the device—which resulted in the generation of hydrogen and hydrogen peroxide.

In their study scientists collaborated on the developing size and form of gold nanoparticles from various VFD processing parameters and concentrations of gold chloride solution.

Through this research, they have discovered a new phenomenon in the vortex fluidic device. The photo-contact electrification process at the solid-liquid interface which could be used in other chemical and biological reactions.

They also have achieved synthesis of pure, pristine gold nanoparticles in water in the VFD, without the use of chemicals commonly used—and thus minimizing waste.

This method is significant for the formation of nanomaterials in general because it is a green process, quick, scalable and yields nanoparticles with new properties.

Gold nanoparticles' size and shape are critical for a range of applications—from drug delivery to catalysis, sensing and electronics—due to their physical, chemical and optical properties.

The vortex fluidic device, devised a decade ago is a rapidly rotating tube open at one end with liquids delivered through jet feeds. Different rotational speeds and external application of light in the device can be used to synthesize particles to specification.

Researchers around the world are now finding the continuous flow, thin film fluidic device useful in exploring and optimizing more sustainable nano-scale processing techniques.

In this latest experiment, the researchers hypothesize that the high shear regimes of the VFD led to the quantum mechanical effect known as contact electrification, which is another exciting development.

Badriah M. Alotaibi et al, Nanogold Foundry Involving High‐Shear‐Mediated Photocontact Electrification in Water, Small Science (2024). DOI: 10.1002/smsc.202300312

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 8:57am

IL-21 plays a crucial role in the formation of bone marrow plasma cells. Cells formed in IL-21-dependent follicular germinal centers have low CD19 expression, while those from IL-21-independent extrafollicular reactions have high CD19 levels.

Primary immune responses produce both CD19low and CD19high BMPCs, but secondary responses mainly create CD19high cells from reactivated memory B cells in extrafollicular sites. This finding is important for understanding how long-term immunity is maintained and how previous immune responses can impact the effectiveness of future vaccinations.

The rapid extrafollicular immune responses in tissues, like the bone marrow itself, are especially crucial for responding to emerging variants quickly. This research could help optimize vaccination strategies for better long-term protection.

Marta Ferreira-Gomes et al, Recruitment of plasma cells from IL-21-dependent and IL-21-independent immune reactions to the bone marrow, Nature Communications (2024). DOI: 10.1038/s41467-024-48570-0

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Part 2

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 8:56am

Study demonstrates how cytokines produce long lasting humoral immunity following vaccination

A new study has shed new light on how cytokines, in particular interleukin 21(IL-21), shape long lasting humoral immunity following vaccination.

Published in Nature Communications, the study  elucidates how various immune responses impact the recruitment and maintenance of memory plasma cells in the bone marrow. These cells are crucial for secreting protective antibodies and sustaining humoral immunity throughout a lifetime.

Researchers revealed the heterogeneity of human bone marrow plasma cells (BMPCs) and their origins from various immune reactions.

By analyzing single-cell transcriptomes from individuals vaccinated against SARS-CoV-2 and the triple vaccine against diphtheria, tetanus, and pertussis (DTaP), the team uncovered distinct pathways through which plasma cells are recruited to the bone marrow.

The study categorizes BMPCs into different "clans" based on their transcriptional profiles, presuming that these cells reflect the specific signals they received during their activation in the tissue.

Understanding the mechanisms behind the recruitment and maintenance of plasma cells in the bone marrow is crucial for improving vaccine strategies and developing therapies for immune-related diseases, including chronic inflammatory diseases such as systemic lupus erythematosus.

Part 1

Comment by Dr. Krishna Kumari Challa on May 29, 2024 at 8:44am

Light therapy increases brain connectivity following injury, study finds

Low-level light therapy appears to affect healing in the brains of people who suffered significant brain injuries, according to a study published in Radiology.

Lights of different wavelengths have been studied for years for their wound-healing properties. Researchers at Massachusetts General Hospital (MGH) conducted low-level light therapy on 38 patients who had suffered moderate traumatic brain injury, an injury to the head serious enough to alter cognition and/or be visible on a brain scan. Patients received light therapy within 72 hours of their injuries through a helmet that emits near-infrared light.

The skull is quite transparent to near-infrared light. Once you put the helmet on, your whole brain is bathing in this light. 

The researchers used an imaging technique called functional MRI to gauge the effects of the light therapy. They focused on the brain's resting-state functional connectivity, the communication between brain regions that occurs when a person is at rest and not engaged in a specific task. The researchers compared MRI results during three recovery phases: the acute phase of within one week after injury, the subacute phase of two to three weeks post-injury and the late-subacute phase of three months after injury.

Of the 38 patients in the trial, 21 did not receive light therapy while wearing the helmet. This was done to serve as a control to minimize bias due to patient characteristics and to avoid potential placebo effects.

Patients who received low-level light therapy showed a greater change in resting-state connectivity in seven brain region pairs during the acute-to-subacute recovery phase compared to the control participants.

There was increased connectivity in those receiving light treatment, primarily within the first two weeks. Researchers were unable to detect differences in connectivity between the two treatment groups long term, so although the treatment appears to increase the brain connectivity initially, its long-term effects are still to be determined. 

The precise mechanism of the light therapy's effects on the brain is also still to be determined. Previous research points to the alteration of an enzyme in the cell's mitochondria (often referred to as the "powerhouse" of a cell). 

This leads to more production of adenosine triphosphate, a molecule that stores and transfers energy in the cells. Light therapy has also been linked with blood vessel dilation and anti-inflammatory effects.

"There is still a lot of work to be done to understand the exact physiological mechanism behind these effects, though.

While connectivity increased for the light therapy-treated patients during the acute to subacute phases, there was no evidence of a difference in clinical outcomes between the treated and control participants. Additional studies with larger cohorts of patients and correlative imaging beyond three months may help determine the therapeutic role of light in traumatic brain injury. 

Effects of Low-Level Light Therapy on Resting-State Connectivity Following Moderate Traumatic Brain Injury: Secondary Analyses of a Double-blinded, Placebo-controlled Study, Radiology (2024).

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Comment by Dr. Krishna Kumari Challa on May 28, 2024 at 1:39pm

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