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Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 11:28am

Organoids grown from amniotic fluid
For the first time, researchers have grown organoids — 3D bundles of cells that mimic tissue — directly from cells taken from ongoing pregnancies. The cells were extracted from amniotic fluid around growing fetuses between the 16th and 34th weeks of gestation during standard procedures independent of the study. The team grew organoids from three organs — the small intestines, kidneys and lungs — and also modelled congenital diaphragmatic hernia, a disorder where the diaphragm fails to develop correctly, using cells from samples affected by the disorder. Unlike organoids made from pluripotent stem cells, the amniotic fluid cells already have an organ identity. “There is no reprogramming, no manipulation,” says stem-cell biologist and study co-author Mattia Gerli, “we’re just allowing the cells to express their potential.”

https://www.nature.com/articles/d41586-024-00656-x?utm_source=Live+...

https://www.nature.com/articles/s41591-024-02807-z?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 10:03am

The Arctic could become 'ice-free' within a decade, say scientists

The Arctic could see summer days with practically no sea ice as early as the next couple of years, according to a new study .

The findings, published in the journal Nature Reviews Earth & Environment, suggest that the first ice-free day in the Arctic could occur over 10 years earlier than previous projections, which focused on when the region would be ice-free for a month or more. The trend remains consistent under all future emission scenarios.

By mid-century, the Arctic is likely to see an entire month without floating ice during September, when the region's sea ice coverage is at its minimum. At the end of the century, the ice-free season could last several months a year, depending on future emissions scenarios. For example, under a high-emissions, or business-as-usual, scenario, the planet's northernmost region could become consistently ice-free even in some winter months.

For scientists, an ice-free Arctic doesn't mean there would be zero ice in the water.

Instead, researchers say the Arctic is ice-free when the ocean has less than 1 million square kilometers (386,000 square miles) of ice. The threshold represents less than 20% of what the region's seasonal minimum ice cover was in the 1980s. In recent years, the Arctic Ocean had around 3.3 million square kilometers of sea ice area at its minimum in September.

Projections of an ice-free Arctic Ocean, Nature Reviews Earth & Environment (2024). DOI: 10.1038/s43017-023-00515-9

Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 9:56am

It's quite difficult to eliminate existing error fields, so instead of fixing these coil irregularities, researchers can apply additional magnetic fields surrounding the fusion vessel in a process known as error field correction.
In the past, this approach would have also hurt the plasma's core, making the plasma unsuitable for fusion power generation. This time, the researchers were able to eliminate instabilities at the edge of the plasma and maintain the stability of the core. The research is a prime example of how PPPL researchers are bridging the gap between today's fusion technology and what will be needed to bring fusion power to the electrical grid.

"This is actually a very effective way of breaking the symmetry of the system, so humans can intentionally degrade the confinement. It's like making a very tiny hole in a balloon so that it will not explode.
One of the toughest parts of managing a fusion reaction is getting both the core and the edge of the plasma to behave at the same time. There are ideal zones for the temperature and density of the plasma in both regions and hitting those targets while eliminating instabilities is tough.

This study demonstrates that adjusting the error fields can simultaneously stabilize both the core and the edge of the plasma. By carefully controlling the magnetic fields produced by the tokamak's coils, the researchers could suppress edge instabilities, also known as edge localized modes (ELMs), without causing disruptions or a substantial loss of confinement.

 SeongMoo Yang et al, Tailoring tokamak error fields to control plasma instabilities and transport, Nature Communications (2024). DOI: 10.1038/s41467-024-45454-1

Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 9:54am

To improve a fusion reaction, use weaknesses as strengths

In the Japanese art of Kintsugi, an artist takes the broken shards of a bowl and fuses them back together with gold to make a final product more beautiful than the original.

That idea is inspiring a new approach to managing plasma, the super-hot state of matter, for use as a power source. Scientists are using the imperfections in magnetic fields that confine a reaction to improve and enhance the plasma in an approach outlined in a paper in the journal Nature Communications.

This approach allows you to maintain a high-performance plasma, controlling instabilities in the core and the edge of the plasma simultaneously. That simultaneous control is particularly important and difficult to do. That's what makes this work special.

This is the first time any research team has validated a systematic approach to tailoring magnetic field imperfections to make the plasma suitable for use as a power source. These magnetic field imperfections are known as error fields.

This method was proven to enhance plasma stability under different plasma conditions, for example, when the plasma was under conditions of high and low magnetic confinement.

Error fields are typically caused by minuscule defects in the magnetic coils of the device that holds the plasma, which is called a tokamak. Until now, error fields were only seen as a nuisance because even a very small error field could cause a plasma disruption that halts fusion reactions and can damage the walls of a fusion vessel. Consequently, fusion researchers have spent considerable time and effort meticulously finding ways to correct error fields. Part 1

Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 9:34am

With Geiger counters in hand to measure local levels of radiation and personal protective gear to guard against radioactive dust, they gathered worms from samples of soil, rotting fruit, and other organic material. Worms were collected from locations throughout the zone with different amounts of radiation.

After collecting samples in the field, the team brought them to Mousseau's field lab in a former residential home in Chornobyl, where they separated hundreds of nematodes from the soil or fruit. From there, they headed to a Kyiv hotel, where—using travel microscopes—they isolated and established cultures from each worm.

Back in the lab,  the researchers continued studying the worms—part of which involved freezing them.

They can cryopreserve worms, and then thaw them for study later. That means that they can stop evolution from happening in the lab, something impossible with most other animal models, and very valuable when they want to compare animals that have experienced different evolutionary histories.

They focused their analyses on 15 worms of a nematode species called Oscheius tipulae, which has been used in genetic and evolutionary studies. They sequenced the genomes of the 15 O. tipulae worms from Chornobyl and compared them with the genomes of five O. tipulae from other parts of the world.

The researchers were surprised to find that using several different analyses, they could not detect a signature of radiation damage on the genomes of the worms from Chornobyl.

This doesn't mean that Chornobyl is safe—it more likely means that nematodes are really resilient animals and can withstand extreme conditions, according to the scientists.  They also don't know how long each of the worms we collected was in the Zone, so they can't be sure exactly what level of exposure each worm and its ancestors received over the past four decades.

Wondering whether the lack of genetic signature was because the worms living in Chornobyl are unusually effective at protecting or repairing their DNA, the researchers designed a system to compare how quickly populations of worms grow and used it to measure how sensitive the descendants of each of the 20 genetically distinct worms were to different types of DNA damage.

While the lineages of worms were different from each other in how well they tolerated DNA damage, these differences didn't correspond to the levels of radiation at each collection site. Their findings suggest that worms from Chornobyl are not necessarily more tolerant of radiation and the radioactive landscape has not forced them to evolve.

The results give researchers clues into how DNA repair can vary from individual to individual—and despite the genetic simplicity of O. tipulae, could lead to a better understanding of natural variation in humans.

Sophia C. Tintori et al, Environmental radiation exposure at Chornobyl has not systematically affected the genomes or chemical mutagen tolerance phenotypes of local worms, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2314793121

Part 2

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Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 9:29am

Tiny worms can tolerate Chornobyl radiation

The 1986 disaster at the Chornobyl nuclear power plant transformed the surrounding area into the most radioactive landscape on Earth. Humans were evacuated, but many plants and animals continue to live in the region, despite the high levels of radiation that persist nearly four decades later.

A new study by researchers appearing in Proceedings of the National Academy of Sciences finds that exposure to chronic radiation from Chornobyl has not damaged the genomes of microscopic worms living there today—which doesn't mean that the region is safe, the scientists caution, but suggests that these worms are exceptionally resilient.

In recent years, researchers have found that some animals living in the Chornobyl Exclusion Zone—the region in northern Ukraine within an 18.6-mile radius of the power plant—are physically and genetically different from their counterparts elsewhere, raising questions about the impact of chronic radiation on DNA.

Did the sudden environmental shift select for species, or even individuals within a species, that are naturally more resistant to ionizing radiation?

To find the answer researchers  turned to nematodes, tiny worms with simple genomes and rapid reproduction, which makes them particularly useful for understanding basic biological phenomena. These worms live everywhere, and they live quickly, so they go through dozens of generations of evolution.

Part 1

Comment by Dr. Krishna Kumari Challa on March 6, 2024 at 7:10am

The windshield phenomenon (or windscreen phenomenon) is the observation that fewer dead insects accumulate on the windshields and front bumpers of people's cars since the early 2000s. It has been attributed to a global decline in insect populations caused by human activity, e.g. use of pesticides.

Comment by Dr. Krishna Kumari Challa on March 5, 2024 at 12:07pm

Millions of online research  papers have disappeared

A check on more than 7 million scholarly publications labelled with unique digital object identifiers (DOIs) reveals that 28% are missing from online archives. “Many people have the blind assumption that if you have a DOI, it’s there forever,” says Mikael Laakso, who studies scholarly publishing. But it costs money to preserve digital content, and archiving involves infrastructure, technology and expertise that many smaller organizations do not have access to.

https://www.nature.com/articles/d41586-024-00616-5?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on March 5, 2024 at 10:44am

Such systemic shifts are projected to peak resource extraction by 2040 and then decrease use to only 20% above 2020 levels by 2060. Greenhouse gas emissions would drop by over 80%, stocks of transport-related materials and building materials would fall by 50 and 25% respectively, and land used-use for agriculture would fall by 5%. Concurrently, food production would increase by 40% to support populations; even where there is growth and food security, the global economy would grow by 3%, and the Human Development Index would improve by 7%, boosting incomes and well-being.

Given the failure so far to deliver on many policy commitments in MEAs and the urgency of the triple planetary crisis, the report supports immediate actions, following the principle of "best available science."

 Report: wedocs.unep.org/bitstream/hand … quence=3&isAllowed=y

part 4

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Comment by Dr. Krishna Kumari Challa on March 5, 2024 at 10:43am

Specific recommendations include:

Institutionalizing resource governance and defining resource use paths especially the consideration of sustainable resource use in strategies to implement Multilateral Environmental Agreements (MEAs) and improving the ability of countries to benchmark and set targets for resource consumption and productivity. Directing finance towards sustainable resource use by reflecting the true costs of resources in the structure of the economy (i.e., subsidies, regulation, taxes, nudges, infrastructure, and planning). Additional recommendations include channeling private finance towards sustainable resource use and incorporating resource-related risk into Public and Central Bank mandates.
Mainstreaming sustainable consumption options by making sure consumers have the right information, have access to and are able to afford sustainable goods and services. Such measures must be coupled with regulation to disincentivize or ban resource-intensive options (like non-essential single-use plastic products).
Making trade an engine of sustainable resource use by creating a level playing field where the true environmental and social costs of goods are reflected in prices by introducing MEAs into trade agreements, for example.
Creating circular, resource-efficient and low impact solutions, and business models to include refuse, reduce, eco-design, reuse, repair, and recycling, as well as supportive regulation and evaluation of existing systems.
Implemented together, these policies can transform the built environment, mobility, food, and energy systems, resulting in an upsurge in renewable energies and energy efficiency, decarbonization of material production, more walkable and cyclable cities with better public transportation and remote work opportunities, as well as reduced food loss and waste. High- and upper-middle-income countries would see a dietary shift away from animal protein and more compact cities, while lower-income economies would experience a rise in resource use to enable dignified living.
part3

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