Comment

Comment by Dr. Krishna Kumari Challa on April 13, 2023 at 12:08pm

Predictive power of climate models may be masked by volcanoes

Simulated volcanic eruptions may be blowing up our ability to predict near-term climate, according to a new study published in Science Advances.

The research, led by the National Center for Atmospheric Research (NCAR), finds that the way volcanic eruptions are represented in climate models may be masking the models' ability to accurately predict variations in sea surface temperatures in the tropical Pacific that unfold over multiple years to a decade. These decadal variations in sea surface temperatures in the tropical Pacific are linked to climate impacts across the globe, including variations in precipitation and severe weather. Accurate predictions, therefore, could provide community leaders, farmers, water managers, and others with critical climate information that allows them to plan years in advance.

Because it is well established that large volcanic eruptions can have significant, long-term cooling effects on the climate, researchers expected that the collection of simulations that included the volcanic eruptions would produce more accurate multiyear and decadal climate predictions. Instead, they found that the inclusion of the eruptions degraded the model's predictive capabilities, at least in the tropical Pacific, an area that is especially important because of the connections between sea surface temperatures and near-term climate events.

For example, the simulations that included the volcanoes predicted a subsequent cooling of the sea surface temperatures in the tropical Pacific after the eruptions. In reality, that region of the ocean warmed, a change that was well predicted by the simulations that did not include the volcanic eruptions.

These findings highlight the difficulty of accurately representing the complex climate impacts that follow a volcanic eruption  in a model, a task made more challenging because researchers only have a few real-life examples in the observational record. Scientists know that volcanoes can loft sulfur gases high into the stratosphere where they can transform into sunlight-reflecting aerosols. But how the resulting cooling ultimately affects the entire Earth system, including sea surface temperatures, is not well understood.

Xian Wu, Volcanic forcing degrades multiyear-to-decadal prediction skill in the tropical Pacific, Science Advances (2023). DOI: 10.1126/sciadv.add9364. www.science.org/doi/10.1126/sciadv.add9364

**

Comment by Dr. Krishna Kumari Challa on April 13, 2023 at 11:48am

The team found that adherence to the ultrastructural size principle was essential for avoiding working memory impairment with age. By viewing violation of the ultrastructural size principle and mitochondria-related failures as the key to age-related cognitive impairment, the study ushers in a new era for aging research.

 Violation of the ultrastructural size principle in the dorsolateral prefrontal cortex underlies working memory impairment in the aged common marmoset (Callithrix jacchus), Frontiers in Aging Neuroscience (2023). DOI: 10.3389/fnagi.2023.1146245

Part 2

Comment by Dr. Krishna Kumari Challa on April 13, 2023 at 11:47am

Mitochondria power supply failure may cause age-related cognitive impairment

Brains are like puzzles, requiring many nested and co-dependent pieces to function well. The brain is divided into areas, each containing many millions of neurons connected across thousands of synapses. These synapses, which enable communication between neurons, depend on even smaller structures: message-sending boutons (swollen bulbs at the branch-like tips of neurons), message-receiving dendrites (complementary branch-like structures for receiving bouton messages), and power-generating mitochondria. To create a cohesive brain, all these pieces must be accounted for.

However, in the aging brain, these pieces can get lost or altered, and no longer fit in the greater brain puzzle. A research team has now published a study in Frontiers in Aging Neuroscience on this topic.

Fifty percent of people experience loss of working memory with old age, meaning their ability to hold and manipulate information in the short-term decreases.

Researchers set out to understand why some individuals maintain healthy working memory as they age, while others do not. In the process, they discovered a novel mechanism for the synaptic basis of cognitive impairment.

Prior studies had found that brains lose synapses as they age, and the researchers saw this pattern in their non-human primate model, too. But when they looked at the synapses that remained, they found evidence of a breakdown in coordination between the size of boutons and the mitochondria they contained.

A fundamental neuroscientific principle, the ultrastructural size principle, explains that whenever one part of the synaptic complex changes in size, so too must all the other parts. The synapse, the mitochondria, the boutons—all these parts must scale in accordance with one another. Before this new study, nobody had asked whether this principle could be violated with age or disease.

Researchers  turned to electron microscopy to examine this. This enabled them to visualize these components across many synapses. They found that synaptic loss occurred with healthy and impaired aging, but what differed was the breakdown in the correlation between the sizes of boutons and their mitochondria.

Part 1

Comment by Dr. Krishna Kumari Challa on April 13, 2023 at 10:58am

Time-restricted fasting could cause fertility problems

Time-restricted fasting diets could cause fertility problems according to new research.

Time-restricted fasting is an eating pattern where people limit their food consumption to certain hours of the day. It's a popular health and fitness trend and people are doing it to lose weight and improve their health.

 A new study published recently in Proceedings of the Royal Society B: Biological Sciences shows that time-restricted fasting affects reproduction differently in male and female zebrafish. It is titled, "Fasting increases investment in soma upon refeeding at the cost of gamete quality in zebrafish."

Importantly, some of the negative effects on eggs and sperm quality can be seen after the fish returned to their normal levels of food consumption.

The research team say that while the study was conducted in fish, their findings highlight the importance of considering not just the effect of fasting on weight and health, but also on fertility.

The way organisms respond to food shortages can affect the quality of eggs and sperm, and such effects could potentially continue after the end of the fasting period.

Fasting increases investment in soma upon refeeding at the cost of gamete quality in zebrafish, Proceedings of the Royal Society B: Biological Sciences (2023). DOI: 10.1098/rspb.2022.1556. royalsocietypublishing.org/doi … .1098/rspb.2022.1556

Comment by Dr. Krishna Kumari Challa on April 13, 2023 at 10:48am

New 'AI scientist' combines theory and data to discover scientific equations

In 1918, the American chemist Irving Langmuir published a paper examining the behavior of gas molecules sticking to a solid surface. Guided by the results of careful experiments, as well as his theory that solids offer discrete sites for the gas molecules to fill, he worked out a series of equations that describe how much gas will stick, given the pressure.

Now, about a hundred years later, an "AI scientist" developed by researchers at IBM Research, Samsung AI, and the University of Maryland, Baltimore County (UMBC) has reproduced a key part of Langmuir's Nobel Prize-winning work. The system—artificial intelligence (AI) functioning as a scientist—also rediscovered Kepler's third law of planetary motion, which can calculate the time it takes one space object to orbit another given the distance separating them, and produced a good approximation of Einstein's relativistic time-dilation law, which shows that time slows down for fast-moving objects.

A paper describing the results is published in Nature Communications on April 12.

Combining Data and Theory for Derivable Scientific Discovery with AI-Descartes, Nature Communications (2023). DOI: 10.1038/s41467-023-37236-y

**

Comment by Dr. Krishna Kumari Challa on April 12, 2023 at 12:27pm

Researchers leverage cell self-destruction to treat brain tumours

Glioblastoma is the most common type of brain tumor in adults. The disease is 100% fatal and there are no cures, making it the most aggressive type of cancer. Such a poor prognosis has motivated researchers and neurosurgeons to understand the biology of tumors with the goal of creating better therapies.

A team of researchers have found that glioblastoma tumor cells are particularly sensitive to ferroptosis—a type of cell death that can be triggered by removing certain amino acids from the diet.

First, the researchers found that when they take away certain amino acids in animal models that the glioblastoma cells are more likely to die by ferroptosis. Secondly, they found that removing these amino acids makes the drugs a lot more effective at inducing ferroptosis in cancer cells.

Ferroptosis is an iron-dependent type of "programmed cell death" or a biological process that causes cells to "self-destruct" on command. Our bodies don't need to kill cells unless absolutely necessary, so the process is tightly controlled by certain biological mechanisms. However, researchers are only now beginning to comprehend the process because ferroptosis was recognized only a decade ago.

Every cell has certain safety features to keep it from going through ferroptosis in an unpredictable way. Two amino acids, cysteine and methionine, are critical for preventing the process from starting in cells. We typically pick up these amino acids through our diet.

By depriving animal models of cysteine and methionine through a customized diet, they found that the glioblastoma cells were significantly more likely to die via ferroptosis. They also found that the diet made their chemotherapy drugs more apt at initiating programmed cell death, meaning that very low doses were able to achieve a more potent effect than before. Ultimately, the animal models had improved survival after going on the diet.

This type of diet has also shown to be very effective in sarcoma, lung cancers, and pancreatic cancers, so there is hope that this diet can be used to put some extra umph behind chemotherapy and/or surgery to remove tumors throughout the body.

Pavan S. Upadhyayula, Dominique M. Higgins, Angeliki Mela, Matei Banu, Athanassios Dovas, Fereshteh Zandkarimi, Purvi Patel, Aayushi Mahajan, Nelson Humala, Trang T. T. Nguyen, Kunal R. Chaudhary, Lillian Liao, Michael Argenziano, Tejaswi Sudhakar, Colin P. Sperring, Benjamin L. Shapiro, Eman R. Ahmed, Connor Kinslow, Ling F. Ye, Markus D. Siegelin, Simon Cheng, Rajesh Soni, Jeffrey N. Bruce, Brent R. Stockwell, Peter Canoll. Dietary restriction of cysteine and methionine sensitizes gliomas to ferroptosis and induces alterations in energetic metabolism. Nature Communications, 2023; 14 (1) DOI: 10.1038/s41467-023-36630-w

Comment by Dr. Krishna Kumari Challa on April 12, 2023 at 11:24am

How air pollution causes lung cancer

Air pollution might cause lung cancer by creating inflammation that encourages proliferation of cells with e... — not by mutating DNA itself. The results provide a mechanism that could apply to other cancers caused by environmental exposure and might one day lead to ways to prevent them. “The idea is that exposures to carcinogens could promote cancer without actually doing anything to the DNA,” says medical geneticist Serena Nik-Zainal. “Not every carcinogen is a mutagen.”

Environmental particulate matter measuring ≤2.5 μm (PM_2.5), known to be associated with lung cancer risk, promotes lung cancer by acting on cells that harbour pre-existing oncogenic mutations in healthy lung tissue.

https://www.nature.com/articles/s41586-023-05874-3?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on April 12, 2023 at 11:15am

A day and night difference: Molecular composition of aerosols diffe...

Tiny aerosols particles in the atmosphere have a significant effect on the climate. They affect the climate directly by interacting with solar radiation. Depending on the type of particle, they can block sunlight, cooling the atmosphere, or absorb sunlight, warming the atmosphere. They also affect climate indirectly by acting as seeds for warm and cold cloud formation. But scientists lack information on these aerosols' molecular composition. This is especially true of aerosols during the day and night above agricultural fields.

---

New findings that map the universe's cosmic growth support Einstein... For millennia, humans have been fascinated by the mysteries of the cosmos. ---- Cancer-causing chemicals detected in toys and headphones Cancer-causing chlorinated paraffins are still used in a wide range of everyday products sold in North America, despite their known health harm and being banned in Canada for a decade, according to a new study in Environmental Science: Processes & Impacts. The researchers detected short-chain chlorinated paraffins in more than 85% of products tested, including headphones, plastic toys, clothing, personal care products, and indoor paints purchased in Canad

Comment by Dr. Krishna Kumari Challa on April 12, 2023 at 10:47am

Geoscientist discovers new phosphorus material after lightning strike

After lightning struck a tree in a New Port Richey neighborhood, a University of South Florida professor discovered the strike led to the formation of a new phosphorus material. It was found in a rock—the first time in solid form on Earth—and could represent a member of a new mineral group.

Minerals similar to it can be found in meteorites and space, but can't be  seen this exact material anywhere on Earth.

High-energy events, such as lightning, can cause unique chemical reactions, and in this instance, result in a new material—one that is transitional between space minerals and minerals found on Earth.

When lightning strikes a tree, the ground typically explodes out and the surrounding grass dies, forming a scar and sending electric discharge through nearby rock, soil and sand, forming fulgurites, also known as 'fossilized lightning'.

In wet environments, such as in Florida,  iron will often accumulate and encrust tree roots. In this case, not only did the lightening strike combust the iron on the tree roots, but it combusted the naturally occurring carbon in the tree as well. The two elements led to a chemical reaction that created a fulgurite that looked like a metal 'glob.'

Inside the fulgurite, a colorful, crystal-like matter revealed a material never before discovered.

The experiment, when repeated in a lab,  was unsuccessful and indicates the material likely forms quickly under precise conditions, and if heated too long, will turn into the mineral found in meteorites.

This research may reveal other forms of reduced minerals are plausible and many could have been important in the development of life on Earth.

Luca Bindi et al, Routes to reduction of phosphate by high-energy events, Communications Earth & Environment (2023). DOI: 10.1038/s43247-023-00736-2

Comment by Dr. Krishna Kumari Challa on April 12, 2023 at 9:47am

Evidence found of possible interdomain horizontal gene transfer leading to development of the eye in vertebrates

A group of molecular and chemical biologists,  has found possible evidence of interdomain horizontal gene transfer leading to the development of the eye in vertebrates. In their study, reported in Proceedings of the National Academy of Sciences researchers used the IQ-TREE software program to trace the evolutionary history of genes associated with vision.

Ever since scientists proved that humans, along with other animals, developed due to evolutionary processes, one problem has stood out—how could evolution possibly account for the development of something as complicated as the eyeball? Even Charles Darwin was said to be stumped by the question. In recent times, this seeming conundrum has been used by some groups as a means to discredit evolutionary theory altogether. In this new effort, researchers sought to answer the question once and for all.

Their work began with the idea that vision in vertebrates may have got its start by using light-sensitive genes transferred from microbes. To find out if that might be the case, the team submitted likely human gene candidates to the IQ-TREE program to look for similar genetic sequences in other creatures, most specifically, microbes.

They found a promising candidate, a gene called IRBP. In humans, it encodes for a protein that is used in the eye as part of a process that converts light into electrical pulses that are eventually sent to the brain via the optic nerve. The research team notes that the gene is an essential component of vision in all vertebrates. IRBP is also found in microbes, most specifically in bacterial peptidases, a class of enzymes that is known for recycling proteins.

The researchers note that while IRBP and the protein that it encodes exists in all vertebrates, it does not exist in most invertebrates. This, they suggest, indicates that the IRBP gene may have been transferred from a microbe over 500 million years ago to an ancient vertebrate, leading to the development of light sensitivity, and over time, to organs such as eyeballs.

More information: Chinmay A. Kalluraya et al, Bacterial origin of a key innovation in the evolution of the vertebrate eye, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2214815120

• ‹ Previous
• 1
• …
• 164
• 165
• 166
• 167
• 168
• …
• 848
• Next ›
• Page