Comment

Comment by Dr. Krishna Kumari Challa on July 9, 2023 at 11:19am

Eliminating extra chromosomes in cancer cells prevents tumor growth

Cancer cells with extra chromosomes depend on those chromosomes for tumor growth, a new Yale study reveals, and eliminating them prevents the cells from forming tumors. The findings, said the researchers, suggest that selectively targeting extra chromosomes may offer a new route for treating cancer.

The study was published July 6 in the journal Science.

Human cells typically have 23 pairs of chromosomes; extra chromosomes are an anomaly known as aneuploidy.

If we look at normal skin or normal lung tissue, for example, 99.9% of the cells will have the right number of chromosomes. But we’ve known for over 100 years that nearly all cancers are aneuploid.

However, it was unclear what role extra chromosomes played in cancer — for instance, whether they cause cancer or are caused by it.
For a long time, we could observe aneuploidy but not manipulate it. We just didn’t have the right tools.

But in this new study, researchers used the gene-engineering technique CRISPR to develop a new approach to eliminate entire chromosomes from cancer cells, which is an important technical advance. Being able to manipulate aneuploid chromosomes in this way will lead to a greater understanding of how they function.

Using their newly developed approach — which they dubbed Restoring Disomy in Aneuploid cells using CRISPR Targeting, or ReDACT — the researchers targeted aneuploidy in melanoma, gastric cancer, and ovarian cell lines. Specifically, they removed an aberrant third copy of the long portion — also known as the “q arm” — of chromosome 1, which is found in several types of cancer, is linked to disease progression, and occurs early in cancer development.

When they eliminated aneuploidy from the genomes of these cancer cells, it compromised the malignant potential of those cells and they lost their ability to form tumours.

When investigating how an extra copy of chromosome 1q might promote cancer, the researchers found that multiple genes stimulated cancer cell growth when they were overrepresented — because they were encoded on three chromosomes instead of the typical two.

This overexpression of certain genes also pointed the researchers to a vulnerability that might be exploited to target cancers with aneuploidy.

https://www.science.org/doi/10.1126/science.adg4521

https://news.yale.edu/2023/07/06/eliminating-extra-chromosomes-canc...

Comment by Dr. Krishna Kumari Challa on July 8, 2023 at 12:14pm

Counting bats that protect a park

Comment by Dr. Krishna Kumari Challa on July 7, 2023 at 11:14am

‘Overweight’ BMI might be set too low

People with an ‘overweight’ body mass index (BMI) have a slightly lower rate of de..., suggesting that the threshold at which higher weight might be a health risk is not accurate. The BMI was developed to assess population-level health but is often used to give health advice to individuals. Researchers tracked the survival of an ethnically diverse group of around 500,000 US adults for up to 20 years and found that having a BMI between 25 and 29.9 — classified as ‘overweight’ — is associated with an 5–7% lower risk of death than having one in the ‘healthy’ range. Lead researcher Aayush Visaria says this shows that “BMI overall is just not a good indicator of mortality risk — other factors such as body fat distribution also play an important role”.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0...

--

Disinformation researchers under pressure

Researchers who study conspiracy theories say that they are now being drawn into one: allegations that they are helping to suppress conservative opinions in the United States. There are at least three House of Representatives judiciary committ..., government programmes designed to counter disinformation and social-media platforms, such as Twitter and Facebook. In parallel, some researchers are facing lawsuits or being blocked from working with federal agencies. The moves contribute to a worrying trend in which climate scientists, for instance, are targeted by conservative activists and leaders. “This is a practice that is going to touch more and more researchers’ lives,” says political scientist Rebekah Tromble.

https://www.nature.com/articles/d41586-023-02195-3?utm_source=Natur...

---

Climate-friendly air conditioning inspired by termites

The climate control used by termites in their mounds could inspire tomorrow's climate-smart buildings. New research from Lund University in Sweden shows that future buildings inspired by the termites could achieve the same effect as traditional climate control, but with greater energy efficiency and without its carbon dioxide footprint.

Comment by Dr. Krishna Kumari Challa on July 7, 2023 at 10:49am

One place to look for evidence of asymmetry is in the electron's electric dipole moment (eEDM). Electrons are made up of negative electric charge, and the eEDM indicates how evenly that charge is spread between the electron's north and south pole. Any measurement of eEDM above zero would confirm an asymmetry; the electron would be more egg-shaped than circular. But no one knows just how small that deviation may be.

Electrons are fundamental particles, and their symmetry tells us about the symmetry of the universe.

Physicists  recently set a record for precision measurement of eEDM, improving on previous measurements by a factor of 2.4. How precise is that? If an electron were the size of the Earth, their study found that any asymmetry that exists would be smaller than the radius of an atom. Making a measurement that precise is incredibly difficult.

The researchers looked at molecules of hafnium fluoride. If they applied a strong electric field to the molecules, non-round electrons would want to align with the field, shifting around inside the molecule. If they were round, then the electrons wouldn't budge. Using an ultraviolet laser, they stripped electrons off molecules, making a set of positively charged ions, and trapped them. Alternating the electromagnetic field around the trap, the molecules were forced to either align or not align with the field. Then the researchers used lasers to measure the energy levels of the two groups. If the levels were different between them, that would indicate that the electrons were asymmetrical.

Their experiment allowed them to have longer measurement times than past attempts, which gave them greater sensitivity. However, the group's measurements showed that the electrons didn't move energy levels, indicating that as best as we can presently measure, electrons are round.

this level of precision from a tabletop experiment is an achievement. It shows that expensive particle accelerators are not the only means of exploring these fundamental questions about the universe, and that there are a lot of avenues to try. And while the group didn't find asymmetry, its result will help the field keep looking for answers to the asymmetry of the early universe.

Tanya S. Roussy et al, An improved bound on the electron's electric dipole moment, Science (2023). DOI: 10.1126/science.adg4084

Part2 

**

Comment by Dr. Krishna Kumari Challa on July 7, 2023 at 10:45am

Why does matter exist? Roundness of electrons may hold clues

In the first moments of our universe, countless numbers of protons, neutrons and electrons formed alongside their antimatter counterparts. As the universe expanded and cooled, almost all these matter and antimatter particles met and annihilated each other, leaving only photons, or flashes of light, in their wake.

And if the universe were perfectly symmetrical, with equal amounts of matter and antimatter, that would be the end of the story—and we would never have existed. But there must have been an imbalance—some leftover protons, neutrons and electrons—that formed atoms, molecules, stars, planets, galaxies and eventually, people.

If the universe had been perfectly symmetrical, then there would be nothing left but light. This is a hugely important moment in history. Suddenly there is stuff in the universe, and the question is, why? Why do we have this asymmetry?

The mathematical theories and equations that explain our universe call for symmetry. Particle theorists have refined these theories to tackle the presence of asymmetry. But without evidence, those theories are just math. So experimental physicists  have been looking at fundamental particles such as electrons for signs of asymmetry. Now they made a record-breaking measurement of electrons, narrowing down the search for where this asymmetry came from. The findings have been published in Science.

Part 1

Comment by Dr. Krishna Kumari Challa on July 6, 2023 at 12:47pm

How do fireworks actually work?

Comment by Dr. Krishna Kumari Challa on July 6, 2023 at 12:45pm

Use It or Lose It
As we age, the overall number of muscle cells declines: Studies suggest that muscle mass decreases by about 3 to 8 percent per decade after age 30 and at higher rates after age 60. Loss of muscular function and other factors also degrade the connection between motor nerves in the brain and muscle tissue. Issues in communication between nerves and muscles can create weakness and a decline in muscle mass. Experts recommend so-called high-velocity resistance training to keep the muscles ready to respond and the brain-muscle connection sharp.

Why this matters: Muscle loss is a common contributor to severe falls and accidents that lead to injury or physical disability in older adults. Low muscle mass from aging can impact how well individuals cope with cancer treatment, surgeries and heart and lung problems. It can impact individual lifespan and how quickly one recovers from illness and hospital stays.

What the experts say: Even if people don’t notice muscle mass gains through resistance training at first, “you actually get stronger long before your muscles get bigger,” says Stephanie Studenski, a geriatrician and professor emeritus at the University of Pittsburgh. “That exercise is doing something to the wiring to the nervous system connection to the muscle.”

Experts recommend so-called high-velocity resistance training to ke....

Comment by Dr. Krishna Kumari Challa on July 6, 2023 at 12:31pm

Why some people get sick more often

One reason why some people are more susceptible to falling ill than others is their body's response to inflammation. “We all need some inflammation, but it has to be the right amount at the right place at the right time,” says physician-scientist Sunil Ahuja. Ahuja and his colleagues found that some people’s immune systems are better at bouncing back from infec... that trigger inflammation. There’s no sure way to predict how you’ll weather any particular bout of disease, but Ahuja recommends reducing exposure risks (by wearing a protective mask, for example) and — this won’t surprise you — enjoying a healthy diet and plenty of exercise.

Scientific American | 6 min read
Reference: Nature Communications paper

Comment by Dr. Krishna Kumari Challa on July 6, 2023 at 12:14pm

New radio observations confirm unintended electromagnetic radiation...

Scientists from a number of leading research institutions including the Max Planck Institute for Radio Astronomy in Bonn, Germany, used the Low Frequency Array (LOFAR) telescope to observe 68 of SpaceX's satellites. The authors conclude that they detected "unintended electromagnetic radiation" emanating from onboard electronics.

--

Facial recognition technology could soon be everywhere—here's how t...

The recent coronation of King Charles III was a high-profile example of when facial recognition technology has been used to monitor a crowd, but there are plenty of others. The technology is used by law enforcement all over the UK and other countries.

Comment by Dr. Krishna Kumari Challa on July 6, 2023 at 12:12pm

Study shows the Earth formed from dry, rocky building blocks

Billions of years ago, in the giant disk of dust, gas, and rocky material that orbited our young sun, larger and larger bodies coalesced to eventually give rise to the planets, moons, and asteroids we see today.

Scientists are still trying to understand the processes by which planets, including our home planet, were formed. One way researchers can study how Earth formed is to examine the magmas that flow up from deep within the planet's interior. The chemical signatures from these samples contain a record of the timing and the nature of the materials that came together to form Earth—analogous to how fossils give us clues about Earth's biological past.

Now, a study  shows that the early Earth accreted from hot and dry materials, indicating that our planet's water—the crucial component for the evolution of life—must have arrived late in the history of Earth's formation.

Though humans do not have a way to journey into the interior of our planet, the rocks deep within the earth can naturally make their way to the surface in the form of lavas. The parental magmas of these lavas can originate from different depths within Earth, such as the upper mantle, which begins around 15 kilometers under the surface and extends for about 680 kilometers; or the lower mantle, which spans from a depth of 680 kilometers all the way to the core–mantle boundary at about 2,900 kilometers below our feet.

Like sampling different layers of a cake—the frosting, the filling, the sponge—scientists can study magmas originating from different depths to understand the different "flavors" of Earth's layers: the chemicals found within and their ratios with respect to one another.

Because the formation of Earth was not instantaneous and instead involved materials accreting over time, samples from the lower mantle and upper mantle give different clues to what was happening over time during Earth's accretion.

In the new study, the team found that the early Earth was primarily composed of dry, rocky materials: chemical signatures from deep within the planet showed a lack of so-called volatiles, which are easily evaporated materials like water and iodine. In contrast, samples of the upper mantle revealed a higher proportion of volatiles, three times of those found in the lower mantle.

Based on these chemical ratios, researchers created a model that showed Earth formed from hot, dry, rocky materials, and that a major addition of life-essential volatiles, including water, only occurred during the last 15% (or less) of Earth's formation.

Weiyi Liu, I/Pu reveals Earth mainly accreted from volatile-poor differentiated planetesimals, Science Advances (2023). DOI: 10.1126/sciadv.adg9213. www.science.org/doi/10.1126/sciadv.adg9213

• ‹ Previous
• 1
• …
• 123
• 124
• 125
• 126
• 127
• …
• 843
• Next ›
• Page