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Comment by Dr. Krishna Kumari Challa on October 19, 2021 at 10:05am

So-called junk DNA plays critical role in mammalian development

Nearly half of our DNA has been written off as junk, the discards of evolution: Sidelined or broken genes, viruses that got stuck in our genome and were dismembered or silenced, none of it relevant to the human organism or human evolution.

But research over the last decade has shown that some of this genetic "dark matter" does have a function, primarily in regulating the expression of host genes—a mere 2% of our total genome—that code for proteins. Biologists continue to find whether these regulatory sequences of DNA play essential or detrimental roles in the body or are merely incidental, an accident that the organism can live without.

A new study explored the function of one component of this junk DNA, transposons, which are selfish DNA sequences able to invade their host genome. The study shows that at least one family of transposons—ancient viruses that have invaded our genome by the millions—plays a critical role in viability in the mouse, and perhaps in all mammals. When the researchers knocked out a specific transposon in mice, half their mouse pups died before birth.

This is the first example of a piece of "junk DNA" being critical to survival in mammals.

In mice, this transposon regulates the proliferation of cells in the early fertilized embryo and the timing of implantation in the mother's uterus. The researchers looked in seven other mammalian species, including humans, and also found virus-derived regulatory elements linked to cell proliferation and timing of embryo implantation, suggesting that ancient viral DNA has been domesticated independently to play a crucial role in early embryonic development in all mammals.

Andrew J. Modzelewski et al, A mouse-specific retrotransposon drives a conserved Cdk2ap1 isoform essential for development, Cell (2021). DOI: 10.1016/j.cell.2021.09.021

https://phys.org/news/2021-10-so-called-junk-dna-critical-role.html...

Comment by Dr. Krishna Kumari Challa on October 18, 2021 at 7:50am

Comment by Dr. Krishna Kumari Challa on October 18, 2021 at 7:43am

It's not tough.

4*4+4*4+4–4*4

=16+16+4–16 ( according to BODMAS)

=20

--

(4x4)+(4x4)+4-(4x4)
16+26+4–16=20

--

(4 x 4) + (4 x 4) + 4 -(4 x 4) =
(16) + (16) + 4 - (16) =
36 - 16 = 20.

--

20 is the answer according to BODMAS

Hint: Use BODMAS Rule.
B - Brackets
O - Of
D - Division
M - Multiplication
A - Addition
S - Subtraction

You need to do the calculations in this order, B to S.

Comment by Dr. Krishna Kumari Challa on October 16, 2021 at 9:34am

RFusion: A Robot that Finds and Retrieves Missing Objects

Comment by Dr. Krishna Kumari Challa on October 16, 2021 at 9:12am

Did you know that  every one of us has a brain "fingerprint" and that this fingerprint changes over time?

Comparing the graphs generated from MRI scans of the same subjects taken a few days apart, researchers were able to correctly match up the two scans of a given subject nearly 95% of the time. In other words, they could accurately identify an individual based on their brain fingerprint. That's really impressive because the identification was made using only functional connectomes, which are essentially sets of correlation scores.

When researchers compared  the brain fingerprints of healthy patients with those suffering from Alzheimer's disease. Based on their initial findings, it seems that the features that make a brain fingerprint unique steadily disappear as the disease progresses. It gets harder to identify people based on their connectomes. It's as if a person with Alzheimer's loses his or her brain identity.

Along this line, potential applications might include early detection of neurological conditions where brain fingerprints get disappear. This technique can be used in patients affected by autism, or stroke, or even in subjects with drug addictions. This is just another little step towards understanding what makes our brains unique: the opportunities that this insight might create are limitless.

Dimitri Van De Ville et al, When makes you unique: temporality of the human brain fingerprint, Science Advances (2021). DOI: 10.1126/sciadv.abj0751. www.science.org/doi/10.1126/sciadv.abj0751

https://medicalxpress.com/news/2021-10-brains-fingerprint.html?utm_...

Comment by Dr. Krishna Kumari Challa on October 15, 2021 at 12:13pm

Researchers engineer microorganisms to tackle PET plastic pollution

From overflowing landfills to floating garbage islands in the oceans to microplastics in remote wilderness areas, billions of tons of discarded plastic have created a global pollution crisis.

Comment by Dr. Krishna Kumari Challa on October 15, 2021 at 12:08pm

After two hours, sunscreen that includes zinc oxide loses effectiveness, becomes toxic: study

Sunscreen that includes zinc oxide, a common ingredient, loses much of its effectiveness and becomes toxic after two hours of exposure to ultraviolet radiation, according to a study by scientists.

The toxicity analysis involved zebrafish, which share a remarkable similarity to humans at the molecular, genetic and cellular levels, meaning many zebrafish studies are immediately relevant to people.

Findings were published recently in Photochemical & Photobiological Sciences.

Sunscreens are important consumer products that help to reduce UV exposures and thus skin cancer, but we do not know if the use of some sunscreen formulations may have unintended toxicity because of interactions between some ingredients and UV light.

And sunscreens containing inorganic compounds like zinc oxide or titanium dioxide, that block UV rays, are being marketed more and more heavily as safe alternatives to the organic small-molecule compounds that absorb the rays.

In the experiments conducted now, zinc oxide degraded the organic mixture and caused a greater than 80% loss in organic filter protection against ultraviolet-A rays, which make up 95% of the UV radiation that reaches the Earth. Also, the zinc-oxide-induced photodegradation products caused significant increases in defects to the zebrafish we used to test toxicity. That suggests zinc oxide particles are leading to degradants whose introduction to aquatic ecosystems is environmentally hazardous.

Aurora L. Ginzburg et al, Zinc oxide-induced changes to sunscreen ingredient efficacy and toxicity under UV irradiation, Photochemical & Photobiological Sciences (2021). DOI: 10.1007/s43630-021-00101-2

https://phys.org/news/2021-10-hours-sunscreen-zinc-oxide-effectiven...

Comment by Dr. Krishna Kumari Challa on October 14, 2021 at 12:03pm

Photosynthesizing algae injected into the blood vessels of tadpoles supply oxygen to their brains

Leading a double life in water and on land, frogs have many breathing techniques—through the gills, lungs, and skin—over the course of their lifetime. Now German scientists have developed another method that allows tadpoles to "breathe" by introducing algae into their bloodstream to supply oxygen. The method developed, presented October 13 in the journal iScience, provided enough oxygen to effectively rescue neurons in the brains of oxygen-deprived tadpoles.

The algae actually produced so much oxygen that they could bring the nerve cells back to life. For many people, it sounds like science fiction, but after all, it's just the right combination of biological schemes and biological principles.

This is an idea to combine plant physiology with neuroscience: harnessing the power of photosynthesis to supply nerve cells with oxygen. The idea didn't seem far-fetched. In nature, algae live harmoniously in sponges, corals, and anemones, providing them with oxygen and even nutrients. Why not in vertebrates like frogs?

To explore the possibility, researchers injected green algae, Chlamydomonas renhardtii) or cyanobacteria (Synechocystis) into tadpoles' hearts. With each heartbeat, the algae inched through blood vessels and eventually reached the brain, turning the translucent tadpole bright green. Shining light on these tadpoles prompted both algae species to pump out oxygen to nearby cells.

After distributing algae to the brain, the researchers isolated the tadpole's head and placed it in an oxygen bubble bath with essential nutrients that would preserve the functioning of the cells, allowing the team to monitor neural activity and oxygen levels. As the researchers depleted oxygen from the bath, the nerves ceased firing and fell silent. However, illuminating the tadpole head restarted the neural activity within 15 to 20 minutes, which is about two times faster than replenishing the bath with oxygen without the algae. The revived nerves also performed as well or even better than before oxygen depletion, showing that the researchers' method was quick and efficient.

The team's next step is to see whether the injected algae can survive inside living tadpoles and continue oxygen production without causing an immune response that wreaks havoc on the animals.

iScience, Özugur et al.: "Green oxygen power plants in the brain rescue neuronal activity" www.cell.com/iscience/fulltext … 2589-0042(21)01126-3 , DOI: 10.1016/j.isci.2021.103158

https://phys.org/news/2021-10-photosynthesizing-algae-blood-vessels...

Comment by Dr. Krishna Kumari Challa on October 13, 2021 at 8:37am

When breezy, wear masks outdoors to prevent coronavirus exposure

As the highly infectious delta variant of the coronavirus continues to spread  guidelines from experts recommend even the vaccinated wear masks indoors to prevent exposure and transmission.

However, it is less clear what people should do when outside.

In Physics of Fluids, researchers from the Indian Institute of Technology Bombay found when a person coughs outdoors, wind flowing in the same direction can propagate the virus faster over longer distances than in calm conditions.

The study is significant in that it points to the increased infection risk that coughing in the same direction as the wind could bring about. Based on the results, experts recommend wearing masks outdoors, particularly in breezy conditions.

Other guidelines, such as coughing in an elbow or turning the face away while coughing, should be followed to reduce transmission when socializing outdoors.

Most studies model cough flow using puffs of air or a simple pulsating profile. But a real cough is more complicated, exhibiting turbulent flow with prominent vortical structures swirling like mini whirlpools.

To investigate these vortices, the researchers used a large eddy simulation, a numerical model in computational fluid dynamics that simulates turbulence. They modeled cough jets in breezy conditions and in calm conditions representing a typical indoor environment.

These simulations show even a light breeze of about 5 mph extends effective social distancing by around 20%, from 3-6 feet to 3.6-7.2 feet, depending on cough strength. At 9-11 mph, spreading of the virus increases in distance and duration.

The researchers found the vortices enable bigger droplets to persist in the air longer than has been typically assumed, increasing the time it takes to adequately dilute the viral load in fresh air. As the cough jet evolves and spreads, it interacts with the wind flowing in the same direction, and the bigger infected droplets become trapped in the jet's vortices instead of falling relatively quickly to the ground under gravity.

The increase in residential time of some of the larger droplets will increase the viral load transmitting through the cough jet and, therefore, the chances of infection. Overall, the study highlights increased chances of infection in the presence of even a light breeze.

"Effect of co-flow on fluid dynamics of a cough jet with implications in spread of COVID-19" Physics of Fluids, aip.scitation.org/doi/10.1063/5.0064104

https://phys.org/news/2021-10-breezy-masks-outdoors-coronavirus-exp...

Comment by Dr. Krishna Kumari Challa on October 12, 2021 at 6:53am

Lightning strikes may trigger short-term thinning in the ozone layer

Crack! Lightning strikes are bright and loud—violent enough to shake your bones and light up the sky. Now, a new study led by the University of Colorado Boulder suggests that these powerful events may also alter the chemistry of Earth's atmosphere, even affecting Earth's all-important ozone layer.

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Chemists develop new blueprint for enzyme involved in cancer Scientists have known for decades that a certain class of enzymes is an important player in cell biology because they frequently mutate and become major drivers of cancer. -- Chemists create chemical probe to better understand immune response A trio of chemists at Indiana University Bloomington has created a new sensor to detect chemical changes in immune cells during the breakdown of pathogens. The work could potentially contribute to the early diagnosis and treatment of infectious diseases, such as tuberculosis, that evade certain elements of the body's immune response.

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