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Comment by Dr. Krishna Kumari Challa on November 8, 2024 at 11:21am

 Plate tectonics research provide a new view of deep Earth's carbon emissions

From time to time, when Earth's tectonic plates shift, the planet emits a long, slow belch of carbon dioxide. In a new modeling study published in Geochemistry, Geophysics, Geosystems, researchers show how this gas released from deep Earth may have affected the climate over the past billion years.

Volcanoes, undersea vents, and mid-ocean ridges are all found where Earth's plates collide or separate. Each of these structures gives carbon dioxide a route to escape from the depths of the planet and enter the atmosphere. Although their impact on the climate is minor compared to anthropogenic emissions, gases released from deep Earth are thought to have a substantial impact on the composition of Earth's atmosphere over geologic timescales.

Scientists have often estimated the volume of such carbon emissions solely on the basis of the gas released by plate tectonics. But plate tectonics can also capture carbon by incorporating it into new crust formed at mid-ocean ridges. In the new work, researchers drew on two recent studies about the past billion years of plate movement to more precisely model how much carbon dioxide this process has generated.

The model's findings are consistent with how Earth's climate is thought to have changed over time. For example, the periods during which the model suggests more carbon was being released line up with warmer periods of Earth's history, such as the start of the Ediacaran period about 653 million years ago.

Periods that the model suggests may have had lower levels of carbon outgassing coincide with colder periods of Earth's history, such as the "snowball Earth" period from 700 million to 600 million years ago.

The research also suggests that Pangea's breakup allowed large amounts of carbon dioxide to be released as the planet's plates moved apart, which is consistent with the warming that's thought to have occurred during that time.

Tectonic activity is a major determinant of Earth's atmospheric composition over geologic time, the researchers conclude.

R. Dietmar Müller et al, Solid Earth Carbon Degassing and Sequestration Since 1 Billion Years Ago, Geochemistry, Geophysics, Geosystems (2024). DOI: 10.1029/2024GC011713

Comment by Dr. Krishna Kumari Challa on November 8, 2024 at 9:56am

This tells us that having a yellow bill rather than a red one provided some benefit to these birds over many generations."

The study provides new insights into how animal coloration evolves and may help explain similar color variations seen in other bird species around the world.

Daniel M. Hooper et al, Spread of yellow-bill-color alleles favored by selection in the long-tailed finch hybrid system, Current Biology (2024). DOI: 10.1016/j.cub.2024.10.019

Part 2

Comment by Dr. Krishna Kumari Challa on November 8, 2024 at 9:55am

Researchers discover genetic reason for the red, yellow and orange bills of Australian finches

What gives an Australian finch its brilliantly colored red, yellow or orange bill? A major new study has uncovered the genetic switches controlling these distinctive colors, revealing a key piece in the puzzle of how animals develop their colouration.

The research published in Current Biology, reveals how yellow and red bill colors evolved in the long-tailed finch through changes in just a few key genes that control how birds process yellow pigments from their diet.

The study focused on two subspecies of the long-tailed finch found across northern Australia—one with a yellow bill based in the Kimberley region of Western Australia, and the other with a red bill from the Northern Territory. Where these subspecies meet, they produce hybrid offspring with orange bills.

Most long-tailed finches in Australia today have bright red bills, with the color coming from carotenoid (yellow) pigments in the seeds they eat. The birds produce enzymes that chemically turn the yellow pigments from their diet into red pigments, which are deposited in their growing bills.

By analyzing the DNA of more than 900 finches, the researchers identified the exact genetic changes responsible for the different bill colors. They discovered that yellow-billed finches have genetic variations that prevent them from converting yellow dietary pigments into red ones.

When red-billed and yellow-billed finches mate, their offspring have orange bills. By studying the exact shade of orange in these hybrid birds, researchers could identify the different genes controlling bill colour.

This discovery helps us understand how animals can evolve different color signals, contributing to the amazing colors of nature.

There's another fascinating twist to the story. Birds use carotenoid pigments for decorative feather, skin and bill colors—but also for vision. These pigments are used in the retinas of their eyes, where tiny oil droplets containing carotenoids help filter light and enable colour vision.

This led to a key discovery. While yellow-billed finches don't produce red carotenoids in their bills, they can still make them in their retinas.

It's not that yellow-billed birds lack the genes for making red colouring; rather, they control these genes differently in different parts of their bodies.

The research team found evidence buried deep in the genome—the complete DNA code for the different forms—that the yellow bill color, which first appeared about 100,000 years ago, provided some evolutionary advantage, allowing the genes for yellow bills to spread into populations of red-billed finches.

While red-colored bills were the ancestral state for these finches, we can see natural selection has favored the yellow coloration as these populations have mixed.

Part 1

Comment by Dr. Krishna Kumari Challa on November 8, 2024 at 9:45am

Defense or growth: Study finds trade-off in how plants allocate resources

The more a plant species invests in defense, the less potential it has for growth, according to a new study. Research made possible by open science provides new insights into plant adaptation and interspecies variation.

Pathogens can significantly weaken the fitness of their hosts, sometimes even causing host mortality. Yet considerable variation is found between species in their investment in disease defense. Evolutionary theory predicts that allocation costs regulate this investment, but testing this hypothesis has been challenging.
In a study published in Science, researchers used open databases to identify plant defense genes and growth traits in 184 plant species.

They found striking variation among plant species in the number of defense genes, which ranged from 44 to 2,256. Examples include asparagus, which has only 72 resistance genes, while one chili variety has as many as 1,095.

They also discovered a negative correlation between defense investment and growth traits in wild plants: the higher the proportion of a plant's genome is dedicated to defense genes, the lower growth potential it has.

The study demonstrates the significant role of allocation costs in the generation and maintenance of biodiversity. The findings also shed light on mechanisms that limit the evolution of defense.

Allocation costs refer to the trade-off in distributing resources among different life functions. For plants, this means that if a plant uses many resources (like energy and nutrients) to maintain its defenses, this may detract from other functions such as growth. In other words, the plant must balance its resource use, which can lead to a scenario where a strong defense reduces growth potential, or vice versa.

The study also examined cultivated plants that have been bred for specific traits. In these plants, a negative correlation between growth and defense was not observed due to the breeding that reduced natural variation in the genomes of crop plants.

Michael Giolai et al, A trade-off between investment in molecular defence repertoires and growth in plants, Science (2024). DOI: 10.1126/science.adn2779. www.science.org/doi/10.1126/science.adn2779

Comment by Dr. Krishna Kumari Challa on November 8, 2024 at 9:41am

Large-scale study uncovers genetic factors associated with disk herniations

Lumbar disk herniation is one of the most common structural changes in the lower back and the most common cause of radiating pain, or sciatica, in the leg. Hereditary risk factors for disk herniations were investigated in an international study utilizing data from FinnGen, the Estonian Biobank, and the UK Biobank. The study, published in Nature Communications on 7 November, analyzed the genetic and health data of 829,699 participants.

The study found 41 novel regions of the genome that modify the disease risk for disk herniations, in addition to the previously identified 23 regions. In the study, numerous genomic regions potentially affecting the structure of the disks and inflammatory factors were found.

In addition to these, the study identified new associations near genes related to the nervous system and nerve function. Findings related to the functioning of the nervous system have increased our understanding of the connection between symptomatic disk herniations and radiating pain.

The study also analyzed disk herniation patients who required surgical treatment. A total of five novel genomic regions were found to be associated with the more severe disk herniations which require surgery.

Genome-wide meta-analysis conducted in three large biobanks expands the genetic landscape of lumbar disc herniations., Nature Communications (2024). DOI: 10.1038/s41467-024-53467-z , www.nature.com/articles/s41467-024-53467-z

Comment by Dr. Krishna Kumari Challa on November 8, 2024 at 8:48am

Neuroimmune communication pathway reveals interactions that may drive endometriosis-associated pain

Researchers have discovered a neuroimmune communication pathway that may drive endometriosis-associated pain and lesion growth.

Endometriosis is a debilitating inflammatory disease affecting up to 15% of women and is characterized by the growth of endometrial-like tissue outside the uterus. Treatments can currently only target symptoms, with over-the-counter pain medicines and hormonal birth control, or in some cases, surgery.

Endometriosis occurs when cell tissues normally found within the uterus lining take root in areas outside the uterus. This tissue is hormonally sensitive and can become inflamed, especially during menstrual cycles, and can cause severe cramping, pain, and other symptoms depending on the area affected.

Because of the abnormal location, the endometrial-like tissues do not vacate during menstruation as similar cells within the lining do. Instead, they can form scar tissues, cysts, lesions, nodules, and connective tissues that can bind to other organs.

In a study, "Nociceptor-to-macrophage communication through CGRP/RAMP1 signaling drives endometriosis-associated pain and lesion growth inmice," published in Science Translational Medicine, the research teams focused on the gene-related peptide (CGRP) and its receptor peptide RAMP1 revealed the nociceptor-to-macrophage communication pathway.

Using samples from eight patients with endometriosis and a mouse model of the disease, the researchers found that both human and mouse endometriosis lesions contain CGRP and its coreceptor RAMP1.

In mice, the team reduced the activity of nociceptors (nerve cells responsible for sensing pain) by employing genetic techniques and chemical treatments. They bred mice to lack specific nociceptor cells and used compounds like resiniferatoxin to deactivate these nerves chemically. This led to decreased pain behaviours and smaller lesion sizes, suggesting that active nociceptors contribute to disease progression.

Victor Fattori et al, Nociceptor-to-macrophage communication through CGRP/RAMP1 signaling drives endometriosis-associated pain and lesion growth in mice, Science Translational Medicine (2024). DOI: 10.1126/scitranslmed.adk8230

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 11:28am

Research in Thailand supports stool DNA as non-invasive alternative for colorectal cancer screening

A recent prospective cross-sectional study  demonstrates that multitarget stool DNA testing is highly sensitive and specific for detecting colorectal cancer (CRC) among  individuals. Researchers  think that this testing method could serve as a viable non-invasive alternative to colonoscopy, especially in settings where colonoscopy is less accessible or less accepted by patients.

Researchers focused on evaluating the diagnostic performance of the multitarget stool DNA testing for detecting CRC and advanced adenoma, using colonoscopy as the reference standard. The study included both asymptomatic and symptomatic patients who underwent stool DNA testing followed by colonoscopy. The multitarget stool DNA test targeted methylation statuses of SDC2, ADHFE1, and PPP2R5C genes. Sensitivity, specificity, and other diagnostic parameters were analyzed.

In the study, data from 274 patients (mean age 62 years, with a predominantly female cohort at 60.6%) was evaluated. Colorectal cancer was identified in 17.2% of participants, while 6.2% were found to have advanced adenomas, which are precursors to cancer.

The multitarget stool DNA test, a non-invasive screening method, yielded impressive results: it detected CRC with a sensitivity of 91.5% and a specificity of 90.3%, accurately identifying cancer in over 90% of cases. The test's sensitivity was consistent across both right-sided and left-sided colon lesions, at 92.3% and 91.2%, respectively.

For advanced colorectal neoplasms, which include both CRC and advanced adenomas, the test demonstrated a sensitivity of 75% and a specificity of 91.9%, marking it as a promising tool for the early detection of serious colorectal conditions. These findings highlight the test's potential as an effective screening option for detecting CRC, especially for larger lesions, although some limitations remain for detecting smaller-sized abnormalities.

BGI Genomics' COLOTECT stool DNA testing kits were used for sample and raw data collection. COLOTECT is a non-invasive tool for early colorectal cancer detection based on DNA methylation testing, targeting the methylation profile of colorectal exfoliated cells to assess the risk of colorectal cancer and advanced adenomas.

This tool requires no special equipment, imposes no dietary restrictions, and is entirely non-invasive. In recent years, DNA methylation-based colorectal cancer detection has gained recognition, being incorporated into multiple CRC screening guidelines and expert consensus worldwide.

Varut Lohsiriwat et al, Diagnostic Accuracy of Multitarget Stool DNA Test for Colorectal Cancer Screening and Detecting in Thailand, Asian Pacific Journal of Cancer Prevention (2024). DOI: 10.31557/APJCP.2024.25.10.3661

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 11:24am

Fecal transplants may involve more than bacterial transfer, study suggests

In a novel study that identified male chromosome genetic material in the intestines of female patients undergoing fecal transplants, researchers  say they have significantly expanded scientific understanding of how some of these transplants may succeed and work.

Fecal microbiota transplant, or FMT, is a procedure in which stool from healthy donors is transplanted via colonoscopy into the bowels of people with dangerous and recurrent infections caused by a bacterium called Clostridioides difficile (C. difficile). Many previous studies show that the transplanted fecal material from healthy donors restores the balance of good bacteria that are markers of a healthy gut in people whose recurrent C.difficile infections have been treated with heavy duty antibiotics that wipe out "good" bacteria as well as bad.

Recurrent C. difficile infection is an often debilitating condition marked by severe diarrhea and inflammation of the colon. Researchers say the infections are notoriously difficult to treat, with conventional antibiotic therapies often failing to provide long-term relief and cure of the infection.

The new study, described in the journal Gastro Hep Advances on October 18, shows that transfer donor cells that line the intestinal tract along with the donor's fecal matter may be responsible for improved outcomes for at least some patients.

This study suggests the possibility of donor intestinal epithelial cell transfer during fecal microbiota transplant, rather than the mere transfer of bacteria from donor fecal samples, can be more effective.

Donor intestinal epithelial cells live in the inner lining of the colon and the small intestine. These cells maintain the intestine's structural integrity and functional capacity. Humans shed millions of these cells into the fecal stream every day. In the new study, the researchers found that the SRY gene responsible for the male-defining characteristics of Y chromosomes, along with evidence of the Y chromosome itself, was detected in the fecal samples of some female patients receiving FMT from male donors.

The long-term detection of the Y chromosome suggests that, in addition to the intestinal microbiota restoration, FMT may facilitate epithelial repair in the gut lining resulting in the altered milieu of the intestinal ecosystem. These observations open up a deeper understanding of the mechanism by which FMT works.

This research points to a much more complex interaction between the donor microbiome and the recipient's gut environment than previously reported.

This finding suggests that stool is a much more complex excretion than we thought it was.

However, more studies are needed in a larger group of female patients who receive FMT from healthy male donors to determine the extent of epithelial "engraftment" in the intestines of FMT patients.

Sudhir K. Dutta et al, Detection of human Y chromosome and SRY gene in fecal samples of female patients following fecal microbiota transplantation, Gastro Hep Advances (2024). DOI: 10.1016/j.gastha.2024.10.008

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Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 10:20am

'Potential misdiagnosis is just a click away': Researchers find design flaws and oversight issues in certain health apps

AI-powered apps offering medical diagnoses at the click of a button are often limited by biased data and a lack of regulation, leading to inaccurate and unsafe health advice, a new study found.

 Researchers presented symptom data from known medical cases to two popular, representative apps to see how well they diagnosed the conditions. While the apps sometimes gave correct diagnoses, they often failed to detect serious conditions, according to findings published in the Journal of Medical Internet Research. This potentially resulted in delayed treatment.

The researchers identified two main issues with the health apps they studied: biased data and a lack of regulation.

The bias issue is known as the "garbage in, garbage out" problem.

These apps often learn from skewed datasets that don't accurately reflect diverse populations.

Because the apps rely on data from smartphone users, they tend to exclude lower-income individuals. Race and ethnicity are also underrepresented in the data, said the authors. This creates a cycle where an app's assessments are based on a narrower group of users, leading to more biased results and potentially inaccurate medical advice.

While apps often include disclaimers stating they do not provide medical advice, the scholar argues that users' interpretations of these disclaimers—if read—do not always align.

The second issue is the "black box" nature of AI systems, where the technology evolves with minimal human oversight. Researchers say lack of transparency means even an app's developers may not fully understand how it reaches conclusions.

Without clear regulations, developers aren't held accountable, making doctors reluctant to recommend these tools. For users, this means a potential misdiagnosis is just a click away.

Ma'n H Zawati et al, Does an App a Day Keep the Doctor Away? AI Symptom Checker Applications, Entrenched Bias, and Professional Responsibility, Journal of Medical Internet Research (2024). DOI: 10.2196/50344

Comment by Dr. Krishna Kumari Challa on November 7, 2024 at 9:49am

Drowsy driving: Not taken as seriously as drunk driving, but it can kill

Some time back my brother-in-law who did two back to back night shifts, actually they 're 48 hour nonstop work shifts, at Airport (he 's  Airport manager for his International  airlines) was driving his car and told us temporarily felt drowsy and hit a person on the road. Luckily the person just fell down with and had just two light bruises but demanded money and my brother in law had to part with Rs.10000 as compensation. From then onwards he has been refusing to work continuously for more than 24 hours. 

Folks are more likely to drive drowsy than drive drunk, even though both raise the risk of a fatal crash, a new survey now shows confirming his fears.

About four in 10 adults say they'll find alternative transportation when they haven't gotten enough sleep, according to a poll conducted online.

By comparison, nearly seven in 10 adults say they won't drive after having a few drinks.

Drowsy driving is a significant threat to road safety, just like drunk, drugged or distracted driving can be, according to scientific studies.

Researchers want the public to know that sleeping only three to four hours before driving is like having a few drinks, and encourage everyone to have a backup plan in place for when they are not alert enough to drive safely, like choosing ride share or taxi options, or calling friends and family to help you and others stay safe.

Drowsy driving is responsible for one in every five deadly motor vehicle crashes, and one of every 10 crashes that result in hospitalization, according to the AAA Foundation for Traffic Safety.

A survey also found that:

• Only half of adults are likely to delay or change plans to avoid driving drowsy, compared to more than eight in 10 following a few drinks
• Just 50% are likely to avoid driving when they haven't gotten enough sleep, compared to almost 90% who've had a few drinks
• More people have urged someone else not to drive because of drinking than for being too tired

Being awake and alert in the driver's seat is as important as not being under the influence, so don't hesitate to change your plans when you shouldn't drive.

To avoid drowsy driving, the NSF recommends that people:

• Get seven to nine hours of sleep
• Plan long trips with a companion who can help a driver stay alert and take the wheel when necessary
• Schedule regular stops every 100 miles or two hours
• Be mindful of warning signs like frequent blinking, yawning or having difficulty with lane and speed control

Source: https://www.nhtsa.gov/risky-driving/drowsy-driving

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