Comment

Comment by Dr. Krishna Kumari Challa on August 3, 2024 at 6:37am

Why editing the knowledge of LLMs post-training can create messy ripple effects

After the advent of ChatGPT, the readily available model developed by Open AI, large language models (LLMs) have become increasingly widespread, with many online users now accessing them daily to quickly get answers to their queries, source information or produce customized texts. Despite their striking ability to rapidly define words and generate written texts pertinent to a user's queries, the answers given by these models are not always accurate and reliable.

In addition, the knowledge available worldwide is in constant evolution. Thus, these models can sometimes report outdated information that they were fed during training, as opposed to other relevant and up-to-date information released after their training. To overcome this limitation of LLMs and increase the reliability of their answers, some computer scientists have been exploring the possibility of editing their knowledge base after they have completed their training.

These knowledge editing (KE) interventions should then influence all the content produced by an LLM, creating a ripple effect. This means that all the model's future answers about a given topic should reflect the new information it acquired about this topic after its knowledge was altered.

Unfortunately, studies suggest that these ripple effects do not always take place. In essence, this means that while a model might be able to correctly answer direct questions about altered information, it might not encompass the new knowledge it acquired in all of the answers it generates, including those that indirectly touch on the new information.

Researchers at University of Illinois Urbana-Champaign recently set out to better understand the processes underlying the successful realization of ripple effects following the editing of LLM knowledge. Their paper, published on the arXiv preprint server, could inform future efforts aimed at updating the knowledge of these widely used models, thus contributing to the improvement of these models post-training.

 Jiaxin Qin et al, Why Does New Knowledge Create Messy Ripple Effects in LLMs?, arXiv (2024). DOI: 10.48550/arxiv.2407.12828

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 12:18pm

Female participants who ate a diet rich in vitamins, minerals, and antioxidants, for instance, had cells with the 'youngest'-looking epigenetic age. Those on the Mediterranean diet were observed to have the slowest epigenetic clocks.

Still, the more added sugar a person consumed each day, the older their salivary DNA appeared to scientists, even when their meals were rich in foods that maintain and repair DNA.

This was true even when accounting for education, lifestyle factors, and the current health of participants.

On average, women in the study ate just over 60 grams of sugar a day, although some ate more than 300 grams a day.
The findings suggest that added sugar can significantly accelerate cellular aging, but it is important to note that this study is only based on food records collected over three non-consecutive days, and one salivary swab.

Previous studies have suggested that cells can appear epigenetically 'younger' or 'older' depending on when in the day their DNA was sampled, so longer term studies among both sexes are needed before further conclusions can be drawn.

https://jamanetwork.com/journals/jamanetworkopen/article-abstract/2...

Part 2

**

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 12:16pm

Added Sugar in Your Diet May Speed Up Your Body's Biological Aging

Eating large amounts of food with added sugar could have a hyperactive effect on the body's ticking biological clock, even when the rest of a person's diet remains otherwise healthy.

A new study among 342 Black and White middle-aged women (please note that the sample size is very low) has found those who eat high quantities of added sugar have 'older-looking' cells.

The findings could help explain why some people seem to age faster or slower than others who have lived the same number of years. Sugar intake could be an important, overlooked factor.

Along with the occasional mutation, our DNA can accumulate less permanent edits over time. These so-called epigenetic changes often act like chemical padlocks, deactivating genes and altering how the body's genetic code is expressed for a time.
A collection of transient edits is referred to as an epigenetic clock, and can be a useful way to guess at a person's true biological age. Epigenetic changes can be read by scientists to better understand how old a cell is and what damages or stresses it has experienced.

Diet, lifestyle, genetics, and disease are all known to affect how quickly a person's epigenetic clock ticks, but this is one of the first studies to examine how sugar specifically plays a role. It also includes a diverse cohort.

The findings suggest that added sugar can alter epigenetic switches related to aging more quickly than healthier foods can turn them off, regardless of whether healthy nutrients are also present.

Part 1

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 12:12pm

Almost Half of Dementia Cases Avoidable by Addressing 14 Risk Factors, Major Study Finds

Millions of cases of dementia could be prevented or delayed by reducing a range of risk factors according to a major new study, though outside experts warn that such measures can only go so far.

The debilitating condition, which progressively robs people of their memories, cognitive abilities, language and independence, currently affects more than 55 million people across the world. Dementia is caused by a range of diseases, the most common of which is Alzheimer's.

A huge review of the available evidence published in The Lancet journal on Wednesday said that the "potential for prevention is high" in the fight against dementia.

The study follows a previous report in 2020 that also emphasised the importance of prevention.

At the time, the international team of researchers estimated that 40 percent of dementia cases were linked to 12 risk factors.

The factors included people having a lower level of education, hearing problems, high blood pressure, smoking, obesity,  depression physical inactivity,  diabetes, excessive drinking, traumatic brain injury, air pollution and social isolation.

The latest update adds two more risk factors: vision loss and high cholesterol.

"Nearly half of dementias could theoretically be prevented by eliminating these 14 risk factors," the study said.

https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(24)00117-X/fulltext

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 12:05pm

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 11:56am

Paper cut physics: the physics behind why some paper is more prone to cut fingers

We all know what it’s like to pick up a sheet of paper, only to get a painful paper cut. The injury is usually small and shallow, but it can really hurt!
Your body has hundreds of nerves. These nerves are spread throughout your body, from head to toe.
In your hands and fingers, though, the nerve endings are densely packed together. So, they’re more sensitive than other areas, like your back or arm.
This explains why paper cuts hurt so much. They commonly affect the hands and fingers, which have a higher density of nerve endings.
But what about all the blood? Well, the capillaries in your hands and fingers are closely packed together. This means paper cuts can cause a lot of bleeding because of how concentrated blood can be in your hands.

In experiments with a gelatin replica of human tissue, researchers found that a thin sheet of paper tended to buckle before it could cut. Thick paper typically indented the material but didn’t pierce it: Like a dull knife blade, it didn’t concentrate force into a small enough area. A thickness of around 65 micrometers was a paper cut sweet spot — or sore spot — physicist Kaare Jensen and colleagues report in a paper to appear in Physical Review E.

That makes dot matrix printer paper the most treacherous, the researchers say. (That paper is seldom used today ). Paper from various magazines was a close second in the scientists’ tests. 

The angle of slicing also played a role. Paper pressed straight down into the gelatin was less likely to cut than paper that cleaved across and down.

S.F. Arnbjerg-Nielsen, M.D. Biviano and K.H. Jensen. Competition between slicing and buckling underlies the erratic natu.... Physical Review E, in press, 2024.

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 9:35am

One outcome of the study could be that "health care providers might more strongly consider recommending aspirin to patients who have less healthy lifestyles.
Previous studies have found evidence to suggest aspirin can reduce the production of pro-inflammatory proteins, known as prostaglandins, that can promote the development of cancer. Aspirin may also block signaling pathways that cause cells to grow out of control, influence the immune response against cancer cells, and block the development of blood vessels that supply nutrients to cancer cells.

Aspirin likely prevents colorectal cancer through multiple mechanisms.
The study did not assess potential side effects of daily aspirin use, such as bleeding. In addition, while the study tried to control for a wide range of risk factors for colorectal cancer, in comparing non-aspirin and aspirin-taking groups with the same level of risk factors, because this was an observational study, it is possible there may have been additional factors that influenced the findings.

 Aspirin Use and Incidence of Colorectal Cancer According to Lifestyle Risk, JAMA Oncology (2024). DOI: 10.1001/jamaoncol.2024.2503

Part 2

**

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 9:32am

Study finds regular aspirin use associated with greatest reduction in colorectal cancer among those most at risk

Regular aspirin may help lower risk of colorectal cancer in people with greater lifestyle-related risk factors for the disease, according to a study by researchers. 

 The study, published in JAMA Oncology, could encourage a more nuanced approach to preventive aspirin use.

The U.S. Preventive Services Task Force previously recommended daily low-dose aspirin to prevent cardiovascular events and colorectal cancer in all adults ages 50 to 59 (the highest risk age group for colorectal cancer). In 2016, they withdrew the recommendation in part due to concerns about aspirin increasing the risk of gastrointestinal bleeding.

For the study, researchers analyzed the health data from 107,655 participants from the Nurses' Health Study and Health Professionals Follow-Up Study. They compared the colorectal cancer rates in those who took aspirin regularly with those who did not take aspirin regularly. Regular aspirin use was defined as either two or more standard dose (325 mg) tablets per week or daily low-dose (81 mg) aspirin.

Study participants were followed starting from an average age of 49.4 years. Those who regularly took aspirin had a colorectal cancer 10-year cumulative incidence of 1.98%, compared to 2.95% among those who did not take aspirin.

The benefit of aspirin was largest among those with the unhealthiest lifestyles. Those with the lowest healthy lifestyle scores (unhealthiest) had a 3.4% chance of getting colorectal cancer if they did not take regular aspirin and a 2.12% chance of getting colorectal cancer if they took aspirin regularly.

By contrast, in those with the highest healthy lifestyle scores (healthiest), the colorectal cancer rates were 1.5% in regular aspirin-taking group and 1.6% in the non-regular aspirin group. This means that in the least healthy group, treating 78 patients with aspirin would prevent one case of colorectal cancer over a 10-year period, while it would take treating 909 patients to prevent one case for the healthiest group.

Lifestyle scores were calculated based on  body mass index, frequency of cigarette and alcohol use, physical activity, and adherence to a high-quality diet.

These results show that aspirin can proportionally lower the markedly elevated risk in those with multiple risk factors for colorectal cancer.

In contrast, those with a healthier lifestyle have a lower baseline risk of colorectal cancer, and, therefore, their benefit from aspirin was still evident, albeit less pronounced.

Part1

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 8:47am

Warming breaks down symbiosis

Hotter conditions prevent two tiny organisms working together for mutual benefit, new research shows.

Scientists studied a single-celled organism (Paramecium bursaria) which can absorb and host algae (Chlorella spp). This pairing is common in freshwater worldwide, and their symbiotic relationship provides benefits including trading of nutrients and protection for the algae.

But when scientists made the water 5°C warmer, the partnership stopped working—and the results suggest the algae may even become parasitic.

The breakdown of such relationships could have a major impact on ecosystems.

The paper, published in the journal Aquatic Biology, is titled "One year of warming leads to the total loss of productivity in a widespread photosymbiosis."

This kind of relationship—called photosymbiosis—is an important part of freshwater and ocean ecosystems.

To illustrate their importance, these relationships provide around half of all marine photosynthesis.

A well-known example is found in coral reefs—where the reef-building corals host resident photosynthetic partners. In recent years, we have seen many high-profile 'bleaching' events—when corals expel these partners, often due to high temperatures, leaving them at risk of stress and mortality.

B Makin et al, One year of warming leads to the total loss of productivity in a widespread photosymbiosis, Aquatic Biology (2024). DOI: 10.3354/ab00769

Comment by Dr. Krishna Kumari Challa on August 2, 2024 at 8:22am

the new study showed that for geographically restricted strains, whether a person has ancestors who lived where the strain is common was an even bigger predictor of infection risk than bacterial load in the sputum. In the cases analyzed in the study, this risk of common ancestry even outweighed the risk stemming from having diabetes and other chronic diseases previously shown to render people more susceptible to infection.

The findings add to a growing body of evidence of the importance of paying attention to the wide variation between different lineages of tuberculosis and to the details of how different lineages of tuberculosis interact with different host populations.

Previous studies have shown that some genetic groups of TB are more prone to developing drug resistance and that TB vaccines appear to work better in some places than others. There is also evidence that some treatment regimens might be better suited to some strains of TB than others.

"These findings emphasize how important it is to understand what makes different strains of TB behave so differently from one another, and why some strains have such a close affinity for specific, related groups of people.

In addition to the analysis of clinical, genomic, and public health data, the researchers also tested the ability of different strains of TB to infect human macrophages, a type of immune cell that TB hijacks to cause infection and disease. The researchers grew cells from donors from different regions. Once again, cell lines from people with ancestry that matched the native habitat of a restricted strain of tuberculosis bacteria were more susceptible to the germs than cells from people from outside the area, mirroring the results of their epidemiologic study.

Differential rates of Mycobacterium tuberculosis transmission associate with host–pathogen sympatry, Nature Microbiology (2024). DOI: 10.1038/s41564-024-01758-y

Part 2

• ‹ Previous
• 1
• …
• 139
• 140
• 141
• 142
• 143
• …
• 1042
• Next ›
• Page