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Comment by Dr. Krishna Kumari Challa on March 6, 2025 at 8:37am

Bacteria use nano-spearguns to retaliate against attacks

Some bacteria deploy tiny spearguns to retaliate against rival attacks. Researchers  have mimicked attacks by poking bacteria with an ultra-sharp tip. Using this approach, they have uncovered that bacteria assemble their nanoweapons in response to cell envelope damage and rapidly strike back with high precision.

The research is published in the journal Science Advances.

In the world of microbes, peaceful coexistence goes hand in hand with fierce competition for nutrients and space. Certain bacteria outcompete rivals and fend off attackers by injecting them with a lethal cocktail using tiny, nano-sized spearguns, known as type VI secretion systems (T6SS).

Bacteria respond to cell envelope damage. 

Using atomic force microscopy (AFM), researchers have been able to mimic a bacterial T6SS attack. With the needle-like, ultra-sharp AFM tip, they could touch the bacterial surface, and by gradually increasing the pressure, puncture the outer and the inner membranes in a controlled manner.

In combination with fluorescence microscopy, the researchers revealed that the bacteria responded to outer membrane damage.

Within ten seconds the bacteria assembled their T6SS, often repeatedly, at the site of damage and fired back with pinpoint accuracy.

In the microbial ecosystem, survival is all about strategy, and Pseudomonas aeruginosa has certainly mastered the art of defense. Their targeted and swift retaliation against local attacks minimizes misfiring and optimizes the cost-benefit ratio.

This clever tactic gives Pseudomonas a survival advantage, enabling it to incapacitate attackers and thrive in diverse and often challenging environments.

Mitchell Brüderlin et al, Pseudomonas aeruginosa assembles H1-T6SS in response to physical and chemical damage of the outer membrane, Science Advances (2025). DOI: 10.1126/sciadv.adr1713

Comment by Dr. Krishna Kumari Challa on March 6, 2025 at 8:26am

Packets of freeze-dried bacteria can grow bio-cement on demand

Cement manufacturing and repair could be significantly improved by using biocement-producing bacteria, but growing the microbes at construction sites remains a challenge. Now, researchers report a freeze-drying approach in ACS Applied Materials & Interfaces that preserves the bacteria, potentially allowing construction workers to ultimately use powder out of a packet to quickly make tiles, repair oil wells or strengthen the ground for makeshift roads or camps.

Soil stabilization and concrete repair are major challenges facing civil engineers. Recently, researchers have shifted their attention to a tiny bacterium called Sporosarcina pasteurii that can produce a form of calcium mineral called biocement. The microbes break down urea and form ammonium and carbonate. Then, with the addition of calcium, the result is calcium carbonate, which glues sand and soil particles together or repairs cracks in existing concrete structures.

To make biocement for construction projects, the bacteria currently must be grown onsite with special equipment and technical know-how. So, researchers wanted to develop a way to preserve S. pasteurii in a shelf-stable format that would be easy for construction workers to use.

They were  inspired by manufacturers who freeze-dry biological components and add them to fertilizers. The researchers suspended the bacteria in different solutions and tested how well the microbes survived freezing. They found that sucrose protected the microbes best compared to other types of protectants. After freezing, the bacteria were dried and then stored in resealable plastic bags. Sucrose-treated S. pasteurii remained viable for at least three months.

Further laboratory testing showed that the sucrose-preserved, freeze-dried bacteria could be used to cement sand in 3D-printed cylindrical molds. The researchers prepared separate columns with play sand, like that used in children's sandboxes, and natural sandy soil taken from the ground. Then, when the columns were sprayed several times with calcium chloride and urea, the bacteria produced biocement. The biocement in the columns made with play sand was stronger than the biocement formed with soil, and most of the biocement samples could be removed from the play sand molds.

Matthew J. Tuttle et al, Shelf-Stable Sporosarcina pasteurii Formulation for Scalable Laboratory and Field-Based Production of Biocement, ACS Applied Materials & Interfaces (2025). DOI: 10.1021/acsami.4c15381

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 10:49am

The study found that the type of land plays a significant role in the density of lightning strikes. Firstly, North India (NI) generally experienced more lightning than Northeast India (NEI). However, the timing differs: NI sees a peak in lightning during the monsoon season (June to September), while NEI is more prone to lightning strikes during the pre-monsoon months (March to May).

Areas with lots of human activity, like farmland and cities, were also shown to have more lightning strikes. Without vegetation covering it around the year, the ground over farmlands heats up quickly, creating the perfect conditions for thunderstorms. Natural landscapes, like forests and grasslands, were shown to have moderate lightning activity, showing us that vegetation, which helps maintain high soil moisture, plays a role in lightning occurrences. Some natural areas, like savannas (grasslands with scattered trees) and wetlands, can also be lightning hotspots.

The mountains also matter. The research revealed that lightning is more common in the foothills of the Himalayas. It is likely caused by surface heating, where moisture-filled air gets pushed upwards, and orographic lifting (mountain formations) in Meghalaya. The height above sea level is also important. Most lightning happens at lower altitudes (below 1600 feet), and the frequency decreases as you go higher up the mountains, especially in North India. Finally, the study found that as farmland and cities expand, lightning activity tends to increase in those areas.

The study shows us that lightning isn't just a random event, instead, it's shaped by the landscape, the vegetation, and even human activities. Understanding these connections can guide safety measures and help farmers and city planners make informed decisions.

https://www.sciencedirect.com/science/article/abs/pii/S136468262500...

part2

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 10:48am

Lightning and Landscapes: How Land and Weather Shape Lightning in India

Lightning is one of the most spectacular natural phenomena, having captivated humans for centuries, sparking both awe and fear.

Today, scientists know exactly why lightning strikes, but predicting where it will strike is much more difficult due to all the factors at play. In fact, the word has become synonymous with unpredictability. But scientists all over the world are trying to uncover these mysteries.

In a new study, researchers have studied how the landscape affects lightning strikes. They have delved into understanding the frequency of lightning in North India (NI) and North-East India (NEI), discovering how land use and topography might predict when and where these electrical bursts will occur.

For their study, the researchers poured thorough data from the Lightning Imaging Sensor (LIS) on the Tropical Rainfall Measuring Mission (TRMM) satellite, recording the location and frequency of lightning strikes between 2001 and 2014. They then combined this lightning data with information about the different types of land in the area - forests, farms, cities, and so on -  obtained from another satellite, Moderate Resolution Imaging Spectroradiometer (MODIS). For topographical details, they consulted the Shuttle Radar Topography Mission or SRTM—a source of detailed 3D maps of Earth's surface.

They also looked at weather-related factors like temperature, humidity, and something called Convective Available Potential Energy (CAPE). CAPE measures how unstable the atmosphere is and how likely it is to produce thunderstorms. They also analysed total cloud cover liquid water (TCCLW) and total cloud cover ice water (TCCIW) along with lightning flash rate density (LFRD) to determine the local temperatures and amount of moisture in the air. They then used computer programs to classify each strike, overlaying their locations on MODIS images to see which land types were struck by lightning. By examining topographical elevations, they categorised these lightning locations by height, revealing patterns at different altitudes.

Part 1. 

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 10:33am

Current antivenom ineffective against a saw-scaled viper bite finds study

The ‘big four’ - Russell’s viper, saw-scaled viper, krait, and Indian cobra, are responsible for most of the snakebite incidents in India.

A new study has now shed light on a concerning issue: the antivenom used to treat bites from the saw-scaled viper (Echis carinatus sochureki) isn't as effective as it should be in certain regions. A team from the Indian Council of Medical Research (ICMR) studied data from a centre treating snakebite victims in Jodhpur, Rajasthan. They found that many patients bitten by the saw-scaled viper weren't responding well to the standard Indian polyvalent antivenom.

Antivenom is a unique mixture made from the antibodies of animals (usually horses) that have been exposed to snake venom. The polyvalent antivenom is designed to work against the venom of the big four snakes, including the saw-scaled viper. When a person is bitten by a venomous snake, the venom can cause a range of problems, from tissue damage and bleeding disorders to paralysis and even death. Antivenom works by binding to the venom in the body and neutralising its harmful effects. Ideally, it should quickly reverse the effects of the venom, allowing the person to recover fully.

The study found that over two-thirds (68.4%) of the patients who received antivenom didn't respond as expected. 103 of the 105 patients experienced venom-induced consumption coagulopathy (VICC), where the venom caused their blood to clot abnormally, leading to bleeding. Around 35% of patients also experienced local and specialised bleeding at the bite site and in other parts of their bodies. Meanwhile, 3 out of 4 patients  (75.7%) also experienced delayed Hypofibrinogenaemia, where their body wasn’t producing enough fibrinogen, a protein essential for blood clotting, even days after the bite. The researchers also found that patients who were bitten in certain areas (the ‘West zone’ of Rajasthan) and those who received higher doses of antivenom were more likely to be unresponsive.

The researchers think the most likely reason for the antivenom's ineffectiveness is that the venom of saw-scaled viper in Rajasthan is different from the venom used to produce the antivenom. Most of the venom used to make India’s polyvalent antivenom comes from saw-scaled vipers in South India. Snakes from different regions can have variations in their venom composition. This means that the antibodies in the antivenom may not bind as effectively to the venom of the vipers in Rajasthan, leaving the venom free to cause damage.

The researchers suggest that the most urgent need is to develop a region-specific antivenom tailored to the venom of Echis carinatus sochureki, the saw-scaled viper in Rajasthan and other regions. This would involve collecting venom from vipers in the region and using it to produce antivenom.

The research highlights a critical gap in our understanding of antivenom and our methods of administering it. The ineffectiveness of the current antivenom against saw-scaled viper venom is a serious concern that begs the question: Does the antivenom work in other regions? Does it work for other venomous snakebites? A comprehensive analysis is the need of the hour to know how we are fair in combating snakebites 

https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd....

https://pubmed.ncbi.nlm.nih.gov/39749523/#:~:text=Conclusions%3A%20....

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 10:16am

Diesel exhaust exposure leads to disarray in liver function in mice; could also indicate health issues for humans

Health researchers have discovered significant changes in liver function following exposure to diesel exhaust (DE) in a controlled study involving mice. The study identified disrupted activity in 658 genes and 118 metabolites. These changes led to a higher production of triglycerides, fatty acids, and sugars, largely due to problems with mitochondria, an organelle in the cell responsible for energy production.

The research is published in the journal Particle and Fibre Toxicology.
The researchers also exposed liver cells to diesel particles and confirmed that the particles were sufficient to activate a gene called Pck1, which led to increased glucose production. Taking it one step further, the researchers inhibited Pck1 to tease out its function. This step reduced glucose levels, confirming Pck1's role in glucose production.

DE emissions play a large role in air pollution and its links to type 2 diabetes, fatty liver disease, cardiovascular diseases, and cancer. Previous research by the same investigators had shown that diesel particles cause mitochondrial dysfunction in liver tissue cells, but the researchers wanted to study the effects in mice. This is the first study to demonstrate the ability of DE exposure to induce mitochondrial dysfunction in vivo.
While there is emerging evidence of a connection between air pollution exposure and metabolic diseases, the exact mechanisms and genes involved are unknown. The researchers say these findings may indicate some of the factors that cause humans to get fatty liver disease and type 2 diabetes after being exposed to DE. 

Gajalakshmi Ramanathan et al, Integrated hepatic transcriptomics and metabolomics identify Pck1 as a key factor in the broad dysregulation induced by vehicle pollutants, Particle and Fibre Toxicology (2024). DOI: 10.1186/s12989-024-00605-6

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 10:03am

Many of the low-latitude regions most threatened by warming are already vulnerable in numerous ways. They face problems with food sufficiency, and economic and systemic forces make them less resilient than northern countries.
But still there are ways that these regions could, at least partly, meet the challenge.
In many low latitude areas, especially in Africa, the yields are small compared to similar areas elsewhere in the world. They could get higher yields with access to fertilizers and irrigation as well as reducing food losses through the production and storage chain. However, ongoing global warming will add a lot of uncertainty to these estimates and probably even more actions are needed, such as crop selection and novel breeding, the scientists say.
While policy-makers in low-latitude countries should work to close those gaps, in mid- and high-latitude regions farmers and policy-makers need more flexibility.
Warming will likely change which crops are grown in those areas, and further changes will come from the array of pressures on the global food system. Coping with those changes will require the ability to adjust and adapt as the consequences of climate change unfold.

Climate change threatens crop diversity at low latitudes, Nature Food (2025). DOI: 10.1038/s43016-025-01135-w. www.nature.com/articles/s43016-025-01135-w

Part 2

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 10:00am

World's critical food crops at imminent risk from rising temperatures, research reveals

Global warming is already reshaping our daily lives, with storms, floods, wildfires and droughts around the world. As temperatures continue to rise, a third of global food production could be at risk. Now, a new study in Nature Food offers a more precise picture of exactly where and how warming will affect our ability to grow food.

Researchers studied how future changes in temperature, precipitation and aridity will affect growing conditions of 30 major food crop species across the globe.

They found that low-latitude regions face significantly worse consequences than mid- or high-latitudes. Depending on the level of warming, up to half of the crop production in low-latitude areas would be at risk as climate conditions become unsuitable for production. At the same time, those regions would also see a large drop in crop diversity.

The loss of diversity means that the range of food crops available for cultivation could decrease significantly in certain areas. That would reduce food security and make it more difficult to get adequate calories and protein, the scientists say.

Up to half of the world's food crop production may be affected

Warming will severely decrease the amount of global cropland available for staple crops––rice, maize, wheat, potato and soybean––which account for over two-thirds of the world's food energy intake.

In addition, "tropical root crops such as yam, which are key to food security in low-income regions, as well as cereals and pulses, are particularly vulnerable. In sub-Saharan Africa, the region which would be impacted most, almost three quarters of current production is at risk if global warming exceeds 3°C.

By contrast, mid- and high-latitude areas will probably retain their productive land overall, though zones for specific crops will change. These areas are also likely to see an increase in crop diversity. For example, the cultivation of temperate fruits, such as pears, could become more common in more northerly regions.

However, even if climatic conditions are favorable, other factors could hamper agriculture in these areas. There's climatic potential but, for example, warming might bring new pests and extreme weather events, which this model doesn't include. So the situation isn't really that black and white.

Part 1

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 9:55am

Scientists genetically engineer mice with thick hair like the extinct woolly mammoth

This week scientists announced that they have simultaneously edited seven genes in mice embryos to create mice with long, thick, woolly hair. They nicknamed the extra-furry rodents as the "Colossal woolly mouse.

Results were posted online, but they have not yet been published in a journal or vetted by independent scientists.

Comment by Dr. Krishna Kumari Challa on March 5, 2025 at 9:31am

Triple bond formed between boron and carbon for the first time

Boron, carbon, nitrogen and oxygen: these four elements can form chemical triple bonds with each other due to their similar electronic properties. Examples of this are the gas carbon monoxide, which consists of one carbon and one oxygen atom, or the nitrogen gas in the Earth's atmosphere with its two nitrogen atoms.

Chemistry recognizes triple bonds between all possible combinations of the four elements—but not between boron and carbon. 

There have long been stable double bonds between boron and carbon. In addition, many molecules are known in which triple bonds exist between two carbon atoms or between two boron atoms.

Chemists have now closed this gap: A team has succeeded for the first time in synthesizing a molecule with a boron-carbon triple bond, a so-called boryne, which exists as an orange solid at room temperature.

In the novel molecule, the boron atom is in a linear arrangement with carbon atoms. In combination with the triple bond, this is about as uncomfortable as it gets for boron, requiring very special conditions.

The scientists characterized the new molecule and also carried out initial reactivity studies. They present the results in the journal Nature Synthesis.

Maximilian Michel et al, The synthesis of a neutral boryne, Nature Synthesis (2025). DOI: 10.1038/s44160-025-00763-1. www.nature.com/articles/s44160-025-00763-1

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