Comment

Comment by Dr. Krishna Kumari Challa on October 8, 2024 at 12:17pm

Chemists use light to replace an oxygen atom with a nitrogen atom in a molecule

A team of chemists  has succeeded in pulling an oxygen atom from a molecule and replacing it with a nitrogen atom. In their study, published in the journal Science, the group used photocatalysis to edit a furan in their lab.

Prior research has shown that some complex molecules can be edited using chemical reactions, but they are few and far between. So chemists must synthesize molecules from scratch when they want to change a small part of a molecule, or even just one atom, for testing.

Such work has shown that even minor changes can have a major impact - changing a single atom in a heterocycle can have a profound impact on the efficacy of a drug. Chemists have been looking for more efficient ways to edit molecules—or more specifically, to remove a single atom and replace it with another.

In this new study, the research team developed a technique they describe as a pencil-and-eraser technique in which one atom is erased and another penciled in.
The researchers were inspired by a paper written by chemists Axel Couture and Alain Lablache-Combier in 1971, in which they used ultraviolet light to convert a furan to a N-propylpyrrole as a way of improving yield. They used ultraviolet light to swap an oxygen atom in a furan with a nitrogen atom.
Part 1

Comment by Dr. Krishna Kumari Challa on October 7, 2024 at 9:45am

47 tigers dead in Vietnam zoos due to bird flu

Forty-seven tigers, three lions and a panther have died in zoos in south Vietnam due to the H5N1 bird flu virus, state media reported recently.

The deaths occurred in August and September at the private My Quynh safari park in Long An province and the Vuon Xoai zoo in Dong Nai, near Ho Chi Minh City, the official Vietnam News Agency (VNA) reported.

According to test results from the National Center for Animal Health Diagnosis, the animals died "because of H5N1 type A virus", VNA said.

No zoo staff members in close contact with the animals had experienced respiratory symptoms, the VNA report added.

Education for Nature Vietnam (ENV), an NGO that focuses on wildlife conservation, said there were a total of 385 tigers living in captivity in Vietnam at the end of 2023.

About 310 are kept at 16 privately owned farms and zoos, while the rest are in state-owned facilities.

The World Health Organization (WHO) says that since 2022, there have been increasing reports of deadly outbreaks among mammals caused by influenza viruses, including H5N1.

It also says H5N1 infections can range from mild to severe in humans, and in some cases can even be fatal.

Vietnam notified the WHO about a human fatality from the virus in March.

In 2004, dozens of tigers died from bird flu or were culled at the world's largest breeding farm in Thailand.

Source: News agencies

Comment by Dr. Krishna Kumari Challa on October 7, 2024 at 9:43am

How a bacterium becomes a permanent resident in a fungus

Comment by Dr. Krishna Kumari Challa on October 7, 2024 at 9:41am

When the researchers allowed the spores with the resident bacteria to germinate, they found that they germinated less frequently and that the young fungi grew more slowly than without them. The endosymbiosis initially lowered the general fitness of the affected fungi.
The researchers continued the experiment over several generations of fungi, deliberately selecting those fungi whose spores contained bacteria. This enabled the fungus to recover and produce more inhabited but viable spores. As the researchers were able to show with genetic analyses, the fungus changed during this experiment and adapted to its resident.
The researchers also found that the resident, together with its host, produced biologically active molecules that could help the host obtain nutrients and defend itself against predators such as nematodes or amoebae.

The initial disadvantage can thus become an advantage.

In their study, the researchers show how fragile early endosymbiotic systems are. The fact that the host's fitness initially declines could mean the early demise of such a system under natural conditions.
For new endosymbioses to arise and stabilize, there needs to be an advantage to living together.
The prerequisite for this is that the prospective resident brings with it properties that favor endosymbiosis. For the host, it is an opportunity to acquire new characteristics in one swoop by incorporating another organism, even if it requires adaptations.

In evolution, endosymbioses have shown how successful they ultimately can become.

Julia Vorholt, Inducing novel endosymbioses by implanting bacteria in fungi, Nature (2024). DOI: 10.1038/s41586-024-08010-x. www.nature.com/articles/s41586-024-08010-x

Part 2

Comment by Dr. Krishna Kumari Challa on October 7, 2024 at 9:38am

Scientists inject bacteria into fungi to study endosymbiosis

Endosymbiosis is a fascinating biological phenomenon in which an organism lives inside another. Such an unusual relationship is often beneficial for both parties. Even in our bodies, we find remnants of such cohabitation: mitochondria evolved from an ancient endosymbiosis. Long ago, bacteria entered other cells and stayed. This coexistence laid the foundation for mitochondria and thus the cells of plants, animals, and fungi.

What is still poorly understood, however, is how an endosymbiosis as a lifestyle actually arises. A bacterium that more or less accidentally ends up in a completely different host cell generally has a hard time. It needs to survive, multiply, and be passed on to the next generation. Otherwise, it dies out. And to not harm the host, it must not claim too many nutrients for itself and grow too quickly. In other words, if the host and its resident cannot get along, the relationship ends.

To study the beginnings of such a special relationship between two organisms, a team of researchers initiated such partnerships in the laboratory. The scientists observed what exactly happens at the beginning of a possible endosymbiosis. They have just published their study in the scientific journal Nature.

Researchers first developed a method to inject bacteria into cells of the fungus Rhizopus microsporus without destroying them. They used E. coli bacteria on the one hand and bacteria of the genus Mycetohabitans on the other. The latter are natural endosymbionts of another Rhizopus fungus. For the experiment, however, the researchers used a strain that does not form an endosymbiosis in nature. They then observed what happened to the enforced cohabitation under the microscope.

After the injection of the E. coli bacteria, both the fungus and the bacteria continued to grow, the latter eventually so rapidly that the fungus mounted an immune response against the bacteria. The fungus protected itself from the bacteria by encapsulating them. This prevented the bacteria from being passed on to the next generation of fungi.

This was not the case with the injected Mycetohabitans bacteria: While the fungus was forming spores, some of the bacteria managed to get into them and thus were passed on to the next generation. The fact that the bacteria are actually transmitted to the next generation of fungi via the spores was a breakthrough in this research.

Part 1

Comment by Dr. Krishna Kumari Challa on October 7, 2024 at 9:27am

Some researchers are working on this problem.

They are exploring advanced positioning technologies to enhance navigation accuracy and reliability. The research covers multiple areas, including the development of a precise ultra-wideband (UWB) system for dense, indoor environments, which is also known as "the indoor GPS," improvements in outdoor vehicular positioning using GNSS, and a novel LEO satellite-based positioning method that addresses many of the limitations of current GNSS systems. Elsanhoury's work involved extensive testing and simulations, demonstrating significant advancements in both indoor and outdoor positioning accuracy.

The research focuses on two distinct technologies: UWB systems for precise indoor positioning and LEO satellites for enhanced outdoor navigation. The UWB technology significantly enhances positioning accuracy within dense indoor settings, while the LEO satellite-based system addresses the limitations of traditional GNSS. 

For outdoor environments, the research work introduces a novel LEO satellite-based positioning method. This approach addresses the impact of GPS jamming and interference, which is a persistent challenge in Finland and other regions. The LEO satellite system employs multiple signal beams to enhance navigation reliability, ensuring accurate positioning even when traditional GNSS systems are compromised. The simulation results conducted were very promising as the new LEO-based method outperformed GNSS amid challenging road conditions, with improved LEO accuracy of 9.15 meters compared to GNSS accuracy of 26.6 meters.

The new, patented method has received international endorsement and recognition.

The development of advanced UWB systems is crucial for navigating complex indoor spaces. The technology has shown resilience in dense industrial environments, also overcoming the common wireless communication impairments. Integrating UWB with other assisting technologies such as inertial motion sensors can lead to more precise location information, and solving challenges posed by traditional systems in confined areas.

 Elsanhoury, Mahmoud. Towards Precision Positioning for Smart Logistics Using Ultra Wide-Band Systems and LEO Satellite-Based Technologies, (2024). Doctoral dissertation. University of Vaasa, urn.fi/URN:ISBN:978-952-395-146-4

Part 2

Comment by Dr. Krishna Kumari Challa on October 7, 2024 at 9:23am

GPS jamming? No problem, low Earth orbit satellites hold the key to resilient, interference-free navigation

People use GPS jammers for a variety of reasons, including:

• Military: The government originally created GPS jammers for military use to conceal vehicle locations and gain an advantage in high-risk situations.
• Speeding: Drivers may use GPS jammers to avoid detection by police and fines.
• Vehicle theft: Criminals may use GPS jammers to cover up vehicle theft.
• Avoid toll charges: Criminals may use GPS jammers to avoid toll charges or mileage charges.
• Fleet management: Drivers may use GPS jammers to prevent their employer from knowing where they are going with the company vehicle. 

GPS jammers are hardware devices that disrupt GPS signals to prevent accurate location tracking and navigation. They can also be used to inhibit mobile devices from making or receiving calls, text messages, or emails. 

GPS jammers are illegal in many countries and can result in harsh penalties, including fines, imprisonment, and loss of equipment. 

Increasingly occurring GPS jamming in some places disrupts daily civilian activities, posing major navigational challenges. A new patented method using low Earth orbit (LEO) satellites and massive multiple input multiple output (MIMO) antennas addresses these location vulnerability issues, presenting means for precise navigation even where traditional global navigation satellite systems (GNSS) fail.

Part 1

Comment by Dr. Krishna Kumari Challa on October 5, 2024 at 8:40am

Researchers create artificial plants that purify indoor air, generate electricity

Most people spend their time indoors and the air we breathe at work, school or home affects our overall health and well-being.

Many sources can generate very toxic materials, like building materials and carpets. We breathe out and breathe in, and that builds up carbon dioxide levels. Also, there are risks from cooking and infiltration from the outdoors.

Most air purification systems, however, are expensive, cumbersome and require frequent cleaning or filter replacement to function at optimum levels.

So researchers are repurposing their research about bacteria-powered biobatteries—ingestible and otherwise—into a new idea for artificial plants that can feed off carbon dioxide, give off oxygen and even generate a little power.

They outline their results in a paper recently published in the journal Advanced Sustainable Systems.

Using five biological solar cells and their photosynthetic bacteria, researchers created an artificial leaf "for fun," then realized the concept has wider implications. They built the first plant with five leaves, then tested its carbon dioxide capture rates and oxygen generation capability.

Although power generation of around 140 microwatts is a secondary benefit, they hope to improve the technology to achieve a minimum output of more than 1 milliwatt. They also want to integrate an energy storage system, such as lithium-ion batteries or supercapacitors.

Other upgrades could include using multiple bacteria species to ensure long-term viability and developing ways to minimize maintenance, such as water and nutrient delivery systems.

With some fine-tuning, these air purifying artificial plants could be a part of every household.

 Maryam Rezaie et al, Cyanobacterial Artificial Plants for Enhanced Indoor Carbon Capture and Utilization, Advanced Sustainable Systems (2024). DOI: 10.1002/adsu.202400401

Comment by Dr. Krishna Kumari Challa on October 4, 2024 at 11:55am

Science finds link between excessive sweating, sensitive skin

If you sweat excessively, you're likely to have sensitive skin as well, with new research confirming the two go hand-in-hand.

It uncovered a significant link excessive sweating -- a condition known as primary hyperhidrosis -- and sensitive skin.
People with primary hyperhidrosis sweat four times more than needed to cool the body -- even when they're not exposed to high temperatures or exercising. The condition affects specific areas such as the hands, feet, face and armpits.

People with sensitive skin often experience itching, burning and tightness when exposed to heat, sweat, skincare products and stress.

Researchers found that folks with hyperhydrosis are more likely than most people to have sensitive skin. Sensitivity often goes beyond areas that sweat excessively, showing that perspiration isn't the cause of their skin sensitivity.

Someone with primary hyperhidrosis is more likely to have sensitive skin than the general public, even in areas where there is no excessive sweating.

The study also showed that:

• The more severe the hyperhidrosis, the greater the skin sensitivity
• Excessive sweating was most often found in the hands
• Respondents with both issues reported frequent sensitivity to products marketed for sensitive skin

Erika T. McCormick MD et al. Primary Hyperhidrosis and Sensitive Skin: Exploring the Link with Predictive Machine Learning-Based Classification Models. Journal of the Drugs and Dermatology. (2024) DOI: 10.36849/JDD.8461

Comment by Dr. Krishna Kumari Challa on October 4, 2024 at 10:58am

Some plants have a backup plan to pass down accurate chromosome copies

Plants rely on fine-tuned genetic processes to pass down accurate copies of chromosomes to future generations. These processes sometimes involve billions of moving parts. Even the tiniest disruption can have a cascading effect. So, for plants like Arabidopsis thaliana, it's good to have a backup plan.

Chromosomes have to be accurately partitioned every time a cell divides. 

For that to happen, each chromosome has a centromere. In plants, centromeres control chromosome partitioning with the help of a molecule called DDM1.

When humans lose their version of DDM1, centromeres can't divide evenly. This causes a severe genetic condition called ICF syndrome. But if the molecule is so important, why isn't Arabidopsis affected when DDM1 is lost?

Scientists found that in yeast, centromere function is controlled by small RNAs. That process is called RNAi. Plants actually have both DDM1 and RNAi.

When they isolated these two in Arabidopsis to see what happens , the plants looked really horrible.

When the team looked closer, they found that a single transposon inside chromosome 5 was responsible for the defects. Transposons move around the genome, switching genes on and off. In Arabidopsis, they trigger DDM1 or RNAi to help centromeres divide. But when DDM1 and RNAi are missing, the process is disrupted.

They found very few copies of this transposon anywhere else in the genome.

But the centromere of chromosome 5 was infested with these things.

The scientists developed molecules called short hairpin RNAs that target the transposons.

Those small RNAs make up for the loss of DDM1. They recognized every copy of the transposon in the centromere and, amazingly, restored centromere function. So now the plants were fertile again. They make seeds. They look much better.

Of course, it's not all about plants. In humans, uneven centromere division has been linked to conditions like ICF and early cancer progression. 

Atsushi Shimada et al, Retrotransposon addiction promotes centromere function via epigenetically activated small RNAs, Nature Plants (2024). DOI: 10.1038/s41477-024-01773-1

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