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Comment by Dr. Krishna Kumari Challa on December 14, 2024 at 11:29am

These sugars are not only essential nutrients for the development of fruits and seeds, but significantly influence the sweetness of fruits and the quality of rice grains.

Heat stress represses CWIN activity and thus disrupts the source-sink balance, resulting in inadequate energy supply in sink organs, reduced reproductive development, and yield penalties.
Researchers developed a strategy based on climate-responsive optimization of carbon partitioning to sinks (CROCS) by rationally manipulating the expression of CWIN genes in fruit and cereal crops.

They precisely knocked-in a 10-bp heat-shock element (HSE) into promoters of CWIN genes in elite rice and tomato cultivars, using self-developed high-efficiency, prime-editing tools. HSE insertion endows CWINs with heat-responsive upregulation in both controlled and field environments to enhance carbon partitioning to rice grains and tomato fruits.

Multi-location and multi-season yield tests on tomatoes under various cultivation conditions, including greenhouses and open fields, showed that under normal conditions, the CROCS strategy increased tomato yields by 14–47%.

Under heat stress, it increased per-plot fruit yield by 26–33% over controls and rescued 56.4–100% of fruit yield losses caused by heat stress. Notably, aspects of fruit quality such as uniformity and sugar content were significantly improved compared to unmodified controls.
In addition, rice cultivars improved by this strategy not only showed a yield increase of 7–13% under normal conditions, but also showed a 25% grain yield increase over controls under heat-stress conditions. Specifically, up to 41% of heat-induced grain losses were rescued in rice.

CROCS is an efficient, versatile, prime-editing based system for rapid crop improvement, which paves the way to rapidly create climate-smart crops by targeted insertion of environment-responsive cis-regulatory elements. The strategy also provides effective gene-editing tools and feasible operational procedures for the fundamental study of plant responses to stress.

The researchers also noted that this breeding strategy has now also been applied to crops such as soybeans, wheat, and corn.

https://english.cas.ac.cn/newsroom/research_news/life/202412/t20241...

Chinese Academy of Sciences

Part 2

Comment by Dr. Krishna Kumari Challa on December 14, 2024 at 11:28am

Scientists innovate breeding strategies to create climate-smart crops

A recent study has reported a novel breeding strategy to rapidly create climate-smart crops that show higher yield under normal conditions and greatly rescue yield losses under heat stress both in staple grain and vegetable crops.

The study,  was published in Cell on 13 December 2024.

 The year 2050 is fast approaching and farm productivity must increase by 60% in order to feed a projected global population of 10 billion. However, current crop production is insufficient and is expected to worsen due to the abiotic-stress burden of climate change.

An increase of 2 °C during the growing season will result in a yield loss of 3–13%. To ensure global food security and overcome breeding bottlenecks, scientists urgently need to develop "climate-smart" crops that achieve higher yields under normal conditions and stable yields under heat stress.

The physiological basis of crop yield and quality is the source-sink relationship. Source tissues (e.g., leaves) are net producers of photoassimilates—i.e., primarily carbohydrates such as sucrose. In contrast, sink tissues (e.g., fruits, seeds, roots, developing flowers, cotton fibers, and storage organs) are net importers, which use or store photoassimilates.

The cell wall invertase gene (CWIN) is the crucial gene regulating the source-sink relationship in plants. The enzyme encoded by this gene unloads and converts sucrose transported from leaves into glucose and fructose within sink organs, where these sugars can be directly absorbed and utilized. Part 1

Comment by Dr. Krishna Kumari Challa on December 13, 2024 at 11:37am

Paracetamol may not be as safe as perceived in older people, according to a new study

Research, led by experts at the University of Nottingham, has found that repeated doses of paracetamol in people aged 65 and over, can lead to an increased risk of gastrointestinal, cardiovascular and renal complications.

The study, which is published in Arthritis Care and Research, shows that care must be taken when repeated doses are required for chronic painful conditions such as osteoarthritis in older people.

Due to its perceived safety, paracetamol has long been recommended as the first line drug treatment for osteoarthritis by many treatment guidelines, especially in older people who are at higher risk of drug-related complications.

The study analyzed data from the Clinical Practice Research Datalink-Gold. Participants were aged 65 and over with an average age of 75.

Researchers looked at the health records of 180,483 people who had been prescribed paracetamol repeatedly (≥2 prescriptions within six months) during the study. Their health outcomes were then compared to 402,478 people of the same age who had never been prescribed paracetamol repeatedly.

The findings showed that prolonged paracetamol use was associated with an increased risk of peptic ulcers, heart failure, hypertension and chronic kidney disease.

Given its minimal pain-relief effect, the use of paracetamol as a first line pain killer for long-term conditions such as osteoarthritis in older people needs to be carefully considered, say the researchers.

Jaspreet Kaur et al, Incidence of side effects associated with acetaminophen in people aged 65 years or more: a prospective cohort study using data from the Clinical Practice Research Datalink, Arthritis Care & Research (2024). DOI: 10.1002/acr.25471

Comment by Dr. Krishna Kumari Challa on December 13, 2024 at 11:21am

Complex bacterial dynamics of urinary tract infections

Urinary tract infections (UTIs) are a major widespread health issue that affects millions of patients globally every year. These infections are not only uncomfortable, but also challenging to treat, as they may often reoccur after the first infection.

A new research study leveraging a mathematical model has now provided a deeper understanding of the complex interactions between different bacterial populations within the bladder and their responses to physiological and therapeutic interventions. This study offers promising pathways for new treatment strategies.

Bacteria are not only present in the urine, but exist in various states in the bladder: free-floating in the bladder lumen, attached to the bladder wall, or even within the bladder's epithelial cells. These different bacterial populations are subjected to different selective pressures, such as immune response and micturition, and antibiotic treatments.

When considering persistent, recurrent infections that need to be treated with antibiotics, there is a higher likelihood that bacteria can adapt and develop resistance during treatment.

This study showed that the different bacterial populations increase the risk of a persistent infection, which then may increase the risk of development of antibiotic resistance. These findings highlight the importance of addressing the diverse bacterial populations and their interactions when treating UTIs.

Another key finding from the study concerns the potential of competitive inoculation as a possible treatment. By introducing a fast-growing, non-pathogenic bacterial strain, pathogenic bacteria can be suppressed. This approach may control the pathogenic population and increase the effectiveness of antibiotic treatment when antibiotics are used in moderation.

This study stresses the importance of considering bacterial compartments in understanding UTIs. By considering the various niches bacteria occupy, and their responses to therapies, this model provides a more realistic view of infection dynamics. It offers valuable insights that could guide and improve future UTI treatments.

Michael Raatz et al, Pathogen non-planktonic phases within the urinary tract impact early infection and resistance evolution, The ISME Journal (2024). DOI: 10.1093/ismejo/wrae191

Comment by Dr. Krishna Kumari Challa on December 13, 2024 at 10:50am

Researchers identify amino acid that prevent sporulation in food poisoning

Food poisoning is a common, yet unpleasant, illness caused by eating contaminated items. It is sometimes caused by Clostridium perfringens, a pathogen widely found in soil and the intestinal tracts of animals.

The pathogen multiplies in environments with little oxygen, for example, curry stored in a pot. After ingestion of the pathogen, they form spores in the small intestinal tracts. The toxins produced during spore formation cause diarrhea and abdominal pain, but the underlying mechanism of spore formation has not been fully understood.

Researchers now examined how amino acids are involved in Clostridium perfringens spore formation. The findings were published in Anaerobe.

In this study, they created 21 culture mediums, 20 of which were each deprived of one of the amino acids that make proteins in the human body, to evaluate the pathogen's development.

As a result, the team identified serine as an inhibitor of Clostridium perfringens spore formation. When observed under a microscope, it was found that serine inhibits the pathogen's cell wall from remodeling, which is necessary in the process of becoming a spore.

This is the first reported case where a single amino acid inhibits spore-forming anaerobic bacteria.

Mayo Yasugi et al, Serine affects engulfment during the sporulation process in Clostridium perfringens strain SM101, Anaerobe (2024). DOI: 10.1016/j.anaerobe.2024.102914

Comment by Dr. Krishna Kumari Challa on December 13, 2024 at 10:24am

Polluting shipwrecks

At the bottom of the oceans and seas lie more than 8,500 shipwrecks from two world wars. These wrecks have been estimated to contain as much as 6 billion gallons of oil, as well as munitions, toxic heavy metals and even chemical weapons.

For decades, these wrecks have largely lain out of site and out of mind. But all this time, their structures have been degrading, inexorably increasing the chances of sudden releases of toxic substances into the marine environment.
In parts of the globe, climate change is exacerbating this risk. Rising ocean temperatures, acidification and increasing storminess accelerate the breakdown of these wrecks.

Of course, wrecks from the world wars are far from the only ones to be found at the bottom of the sea, with many others adding to the problem. The cost of addressing this global issue has been estimated at US$340 billion (£261 billion).

How many of these wrecks pose a threat to people's safety, to coastal communities and to the environment? What can be done—and why haven't we done it sooner?

https://theconversation.com/polluting-shipwrecks-are-the-ticking-ti...

Comment by Dr. Krishna Kumari Challa on December 13, 2024 at 10:06am

As wildfires intensify, prolonged exposure to pollution linked to premature death

Researchers have found evidence that living in areas prone to wildfire smoke may negatively impact an individual's life expectancy.

In many parts of the contiguous United States, wildfires are rapidly growing more intense, endangering the humans and wildlife that live in the region. Even once fires are doused, serious health risks remain because of the many adverse effects caused by wildfire smoke and the airborne pollution that the blaze releases into the atmosphere.

Now, scientists  have found that not only is wildfire smoke linked to a shortened lifespan, it also greatly diminishes the positive health impacts of local greenspaces, like forests or parks.

When considering the environment's effect on human life expectancy, we have to account for all kinds of factors. Forests, for example, provide essential ecosystem services to mitigate the impact of wildfire smoke because they can purify the air.

Generally, greenspaces benefit human health by helping to regulate the local ecosystem and climate through capturing carbon dioxide, oxygen production and air filtration as well as by providing open spaces to foster social and community connection. It's why higher levels of greenspaces are usually correlated with higher life expectancies. But because these lush areas can essentially act as fuel for wildfires, their presence is also tightly correlated with higher wildfire smoke emissions.

 Due to its high toxicity, human exposure to this smoke has been known to cause respiratory issues, cardiovascular disease, and an increase in the risk of dementia and hospitalization.

The research was presented this week at the annual meeting of the American Geophysical Union (AGU 2024).

Their findings concluded that for every additional day of smoke exposure, a person's life expectancy could be expected to decrease by about 0.02 years—or about one week.

Conversely, living in a green neighborhood can be beneficial, as even a 1% increase in these spaces can lead to a slight life expectancy increase. While wildfire smoke can negate the benefits of greenspace, the team's results suggest that sociodemographic factors such as income, population density, age and race also significantly impact future life expectancies.

Impacts of Wildfire Smoke PM2.5, Greenspace and Terrain Ruggedness on Life Expectancy in the Contiguous United States. agu.confex.com/agu/agu24/meeti … pp.cgi/Paper/1620628

Comment by Dr. Krishna Kumari Challa on December 13, 2024 at 9:20am

Neanderthal-human interbreeding lasted 7,000 years, new study reveals

A new analysis of DNA from ancient modern humans (Homo sapiens) in Europe and Asia has determined, more precisely than ever, the time period during which Neanderthals interbred with modern humans, starting about 50,500 years ago and lasting about 7,000 years—until Neanderthals began to disappear.

That interbreeding left Eurasians with many genes inherited from our Neanderthal ancestors, which in total make up between 1% and 2% of our genomes today.

The genome-based estimate is consistent with archaeological evidence that modern humans and Neanderthals lived side-by-side in Eurasia for between 6,000 and 7,000 years.

The analysis, which involved present-day human genomes as well as 58 ancient genomes sequenced from DNA found in modern human bones from around Eurasia, found an average date for Neanderthal-Homo sapiens interbreeding of about 47,000 years ago. Previous estimates for the time of interbreeding ranged from 54,000 to 41,000 years ago.

The new dates also imply that the initial migration of modern humans from Africa into Eurasia was basically over by 43,500 years ago.

The longer duration of gene flow may help explain, for example, why East Asians have about 20% more Neanderthal genes than Europeans and West Asians. If modern humans moved eastward about 47,000 years ago, as archaeological sites suggest, they would already have had intermixed Neanderthal genes.

The period of mixing was quite complex and may have taken a long time. Different groups could have separated during the 6,000- to 7,000-year period and some groups may have continued mixing for a longer period of time. But a single shared period of gene flow fits the data best.

 Leonardo N. M. Iasi et al, Neandertal ancestry through time: Insights from genomes of ancient and present-day humans, Science (2024). DOI: 10.1126/science.adq3010. www.science.org/doi/10.1126/science.adq3010

Arev Sümer, Earliest modern human genomes constrain timing of Neanderthal admixture, Nature (2024). DOI: 10.1038/s41586-024-08420-x. www.nature.com/articles/s41586-024-08420-x

Comment by Dr. Krishna Kumari Challa on December 12, 2024 at 11:46am

Car height, not just speed, matters when pedestrians are hit

Watch out for tall, fast-moving cars. The height of a vehicle, not only its speed, determines its potential danger to a pedestrian, new research shows.

Multiple factors—in this case speed and vehicle height—converge to create negative outcomes on the road.

Measurements of the vehicles involved were used to examine the moderating effect of hood height.

The report involved an analysis of 202 crashes involving people ages 16 and older in cities across the United States. The accidents occurred between 2015 and 2022.

In general, higher vehicle front ends increased the likelihood of both moderate and serious pedestrian injuries, data showed. At 27 mph, the average speed of the crashes, a median-height car had a 60% chance of causing moderate injuries to a pedestrian and a 30% chance of causing serious injuries.

Risks rose along with hood height, however: A median-height pickup—with a front end 13 inches higher than that of a median car—had an 83% chance of causing moderate injuries and a 62% chance of causing serious injuries.

This tracks with earlier IIHS research that found that vehicles with taller front ends are more likely to kill people when they hit them. Compared to smaller cars, large vehicles  such as sports utility vehicles or SUVs, are more likely to harm internal organs.

The increased risk and severity of injury from these vehicles is related to their tendency to inflict more severe injuries higher on the body: to the head, torso, and hip," the study authors explained.

In addition to impact, car size influences how well a driver can see pedestrians.

"Taller vehicles may be more likely to be involved in certain pedestrian crash configurations than shorter ones, potentially due to limitations in driver visibility," the authors said.

In cases where the pedestrian is at the vehicle's front corner, obstructed driver sight lines could make a collision more likely and may reduce pre-impact braking behavior, leading to greater injuries.

What's more, the findings reinforce the importance of redesigning vehicles and roadways to reduce speed in congested areas, the study authors said.

It will take a combination of actions from different corners of the transportation world to improve pedestrian safety.

Monfort, Samuel S., Mueller, Becky C. A modern injury risk curve for pedestrian injury in the United States: the combined effects of impact speed and vehicle front-end height. Insurance Institute for Highway Safety. www.iihs.org/topics/bibliography/ref/2322

Comment by Dr. Krishna Kumari Challa on December 12, 2024 at 11:40am

Tumors grow larger in female fruit flies than males. Here's what that could mean for humans

A study by  researchers has uncovered new insights into how biological sex differences can influence tumor growth. The findings, published in Science Advances, could lead to a better understanding of cancer development and potentially boost efforts to identify a method to stop tumors in their tracks.

The study found that tumors in female fruit flies grew 2.5 times larger than tumors in male fruit flies over the same time period.

Fruit flies are an often used biological research model due to their genetic similarity to humans. In this study, researchers found that the female fruit flies had a stronger innate immune response to the tumors than the males. This response accelerated the growth of tumors by triggering a signaling pathway between cells.

The question now is, do we see this same difference in humans?

Genetically, many of these signaling pathways are well preserved between mammals and insects so this finding is highly relevant to our knowledge of cancer development.

The study found that once a tumor formed, female fruit flies' immune cells (hemocytes) produced more of an inflammatory response signal than their male counterparts. This signal protein, called Eiger, is comparable to a similar protein in mammals, which also regulates immune system and inflammatory responses.

While inflammation is often effective at combating outside invaders, too much inflammation can create an environment that allows tumors to thrive. "We found that in female fruit flies, their stronger immune response caused a downstream cascade of events, culminating in the release of insulin-like peptides which allowed the tumors to accelerate their growth.

The next step is to determine if the bias in tumor growth is regulated by hormones or sex chromosomes, work that may shed further light on why and how tumors grow.

 Xianfeng Wang et al, Sex-dimorphic tumor growth is regulated by tumor microenvironmental and systemic signals, Science Advances (2024). DOI: 10.1126/sciadv.ads4229

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