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Comment by Dr. Krishna Kumari Challa on January 10, 2021 at 9:40am

Entangling electrons with heat

A joint group of scientists from various countries has demonstrated that temperature difference can be used to entangle pairs of electrons in superconducting structures.

 The team has shown that the thermoelectric effect provides a new method for producing entangled electrons in a new device.

In quantum computing, entanglement is used to fuse individual quantum systems into one, which exponentially increases their total computational capacity. "Entanglement can also be used in quantum cryptography, enabling the secure exchange of information over long distances.

Given the significance of entanglement to quantum technology, the ability to create entanglement easily and controllably is an important goal for researchers.

The researchers designed a device where a superconductor was layered withed graphene and metal electrodes. Superconductivity is caused by entangled pairs of electrons called "cooper pairs." Using a temperature difference, they cause them to split, with each electron then moving to different normal metal electrode. "The resulting electrons remain entangled despite being separated for quite long distances.

Thermoelectric current in a graphene Cooper pair splitter, Nature Communications (2021). DOI: 10.1038/s41467-020-20476-

https://phys.org/news/2021-01-entangling-electrons.html?utm_source=...

Comment by Dr. Krishna Kumari Challa on January 10, 2021 at 9:36am

Bacteria can tell the time

Humans have them, so do other animals and plants. Now research reveals that bacteria too have internal clocks that align with the 24-hour cycle of life on Earth.

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The research answers a long-standing biological question and could have implications for the timing of drug delivery, biotechnology, and how we develop timely solutions for crop protection.

Biological clocks or circadian rhythms are exquisite internal timing mechanisms that are widespread across nature enabling living organisms to cope with the major changes that occur from day to night, even across seasons.

Existing inside cells, these molecular rhythms use external cues such as daylight and temperature to synchronise biological clocks to their environment. It is why we experience the jarring effects of jet lag as our internal clocks are temporarily mismatched before aligning to the new cycle of light and dark at our travel destination.

A growing body of research in the past two decades has demonstrated the importance of these molecular metronomes to essential processes, for example sleep and cognitive functioning in humans, and water regulation and photosynthesis in plants.

Although bacteria represent 12% biomass of the planet and are important for health, ecology, and industrial biotechnology, little is known of their 24hr biological clocks.

Previous studies have shown that photosynthetic bacteria which require light to make energy have biological clocks.

But free-living non photosynthetic bacteria have remained a mystery in this regard.

In this international study researchers detected free running circadian rhythms in the non-photosynthetic soil bacterium Bacillus subtilis.

 A circadian clock in a non-photosynthetic prokaryote, Science Advances (2021). advances.sciencemag.org/lookup … .1126/sciadv.abe2086

https://phys.org/news/2021-01-bacteria.html?utm_source=nwletter&...

Comment by Dr. Krishna Kumari Challa on January 10, 2021 at 9:33am

Skin cells protect their DNA from bumps and bruises with a jello-like response

Cells’ responses to microscopic pushes and pulls prevent cancers from forming

https://massivesci.com/articles/skin-cells-mechanics-forces/?utm_so...

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Deadly parasites create unique cellular structures to survive

Scientists have solved a key parasitic puzzle, revealing the unique and complex structures toxoplasmosis and malaria parasites make in order to survive in different hosts.

The new work details how certain parasites can create unique cellular structures to control how they create energy and thus survive in different hosts.

Malaria and toxoplasmosis, both potentially deadly diseases, are caused by similar parasites which organize themselves to exploit their host's energy resources in order to infect and transmit to new hosts. However, until now, scientists didn't fully understand the detailed mechanisms behind this process.

In this new research, researchers have solved a parasitic puzzle at the heart of how these deadly pathogens are able to survive in different hosts in order for them to transmit onwards.

In order to survive these parasites rely on resources available in their host—for toxoplasmosis it is animals and humans, while for malaria this includes also insects. This means that in order to survive, to infect the host and to transmit between hosts, these parasites have to be flexible in how they create energy based on what is available to them.

Scientists studied a vital energy-producing machine within the parasite called ATP synthase. In addition to making energy, ATP synthase machines can also come together into large structures that together shape the mitochondrial membrane, controlling the rate of energy production, and key to its survival. Researchers found that, in these parasites, the ATP synthase machines were able to make complex and unique pentagonal pyramid structures, unlike anything produced by the same systems in their human host.

Alexander Mühleip et al. ATP synthase hexamer assemblies shape cristae of Toxoplasma mitochondria, Nature Communications (2021). DOI: 10.1038/s41467-020-20381-z

https://phys.org/news/2021-01-deadly-parasites-unique-cellular-surv...

Comment by Dr. Krishna Kumari Challa on January 10, 2021 at 9:30am

Identical twins are not so identical

Scientists have quantified the small genetic differences between monozygotic twins. Researchers analysed the DNA of 381 identical twin pairs (and 2 triplets) and found thousands of mutations that appeared in one twin and not the other. Twins differed on average by 5.2 early developmental mutations, which occurred after the initial formation of the zygote. Some siblings differed by dozens of mutations, and some did not differ at all. “The implication is that we have to be very careful when we are using twins as a model” .

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Identical twins are not so identical, study suggests

Research finds they differ by an average of 5.2 early mutations, adding new perspective to nature-versus-nurture debates

https://www.nature.com/articles/s41588-020-00755-1

Comment by Dr. Krishna Kumari Challa on January 10, 2021 at 9:28am

The Riemann Hypothesis, Explained

Comment by Dr. Krishna Kumari Challa on January 7, 2021 at 12:40pm

Quicksand Science: Why It Traps, How to Escape

If stumbling into quicksand ranks on your list of worries, don't panic. A new study suggests that quicksand is not as deadly as it may seem.

https://www.nationalgeographic.com/news/2005/9/quicksand-science-wh...

Comment by Dr. Krishna Kumari Challa on January 7, 2021 at 9:29am

How Earth's oddest mammal got to be so bizarre

Often considered the world's oddest mammal, Australia's beaver-like, duck-billed platypus exhibits an array of bizarre characteristics: it lays eggs instead of giving birth to live babies, sweats milk, has venomous spurs and is even equipped with 10 sex chromosomes. Now, an international team of researchers led by University of Copenhagen has conducted a unique mapping of the platypus genome and found answers regarding the origins of a few of its stranger features.

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It lays eggs, but nurses, it is toothless, has a venomous spur, has webbed feet, fur that glows and has 10 sex chromosomes.

The complete genome has provided us with the answers to how a few of the platypus' bizarre features emerged. At the same time, decoding the genome for platypus is important for improving our understanding of how other mammals evolved—including us humans. It holds the key as to why we and other eutheria mammals evolved to become animals that give birth to live young instead of egg-laying animals.

Yang Zhou et al. Platypus and echidna genomes reveal mammalian biology and evolution, Nature (2021). DOI: 10.1038/s41586-020-03039-0

Paula Spaeth Anich et al. Biofluorescence in the platypus (Ornithorhynchus anatinus), Mammalia (2020). DOI: 10.1515/mammalia-2020-0027

https://phys.org/news/2021-01-earth-oddest-mammal-bizarre.html?utm_...

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Comment by Dr. Krishna Kumari Challa on January 7, 2021 at 9:22am

How an embryo tells time

It is estimated that the majority of pregnancies that fail do so within the first seven days after fertilization, before the embryo implants into the uterus. In this time period, a complicated cascade of events occurs with precise timing. One particularly important process is called polarization, when the individual cells that make up the embryo become asymmetrical. Polarization occurs at 2.5 days for mouse embryos and 3.5 days for human embryos.

Just as musicians playing together in an orchestra need to play at the right time—not early, not late—the timing of polarization is critical for proper embryonic function. Studies have shown that if polarization occurs too early or too late, the embryo is less likely to develop properly. Embryos obviously cannot look at a clock to know when it is time to polarize, so how do they "know" when it is time?

A new study has uncovered the signals that mouse embryos follow to initiate polarization. Understanding the molecular mechanisms underlying embryonic development is critical for understanding how life begins.

The first is the zygotic genome activation, or ZGA, which represents the initial "awakening" of the embryonic DNA after it has combined from sperm and egg, with certain genes for development flipped on like a dormant computer booting up. A flood of molecular activity follows ZGA, and during that period, the team found, three specific factors—protein-based structures called Tfap2c, Tead4, and RhoA—work together to initiate polarization.

This research is the first to identify the necessary and sufficient conditions that drive cell polarization. Once the team had identified the three factors that initiate polarization, they turned their focus to the polarization process itself.

 Meng Zhu et al. Developmental clock and mechanism of de novo polarization of the mouse embryo, Science (2020). DOI: 10.1126/science.abd2703

https://phys.org/news/2021-01-embryo.html?utm_source=nwletter&u...

Comment by Dr. Krishna Kumari Challa on January 7, 2021 at 8:40am

Proteins engineered to form honeycomb structures can block uptake of receptors from the surface of cells

A new class of protein material that interacts with living cells without being absorbed by them can influence cell signaling, a new study shows. The material does this by binding and sequestering cell surface receptors.

The discovery could have far-reaching implications for stem cell research and enable the development of new materials designed to modulate the behavior of living systems.

Cells interact with their environment via receptors at their surface. These receptors can bind to hormones, neurotransmitters, drugs, and toxins. When such molecules bind to a receptor, this triggers a response inside the cell, a process known as signaling.

But for the cell, it is important that this response be transient, to still be responsive to the signal later on. To achieve this, cells will commonly terminate signaling by absorbing both an activated receptor and the molecule that stimulated it, thereby targeting both for destruction inside the cell.

"This tendency of cells to internalize receptors likely lowers the efficiency of immunotherapies. Indeed, when antibody drugs bind their target receptors and then become internalized and degraded, more antibody must always be injected.

To create a way around this, researchers now designed new proteins that assemble into large, flat patches. This molecular scaffolding was then further engineered to contain signaling molecules. They showed that such protein materials could latch onto cells, activate surface receptors, and resist being absorbed by the cell for hours or even days.

This work paves the way towards a synthetic cell biology, where a new generation of multi-protein materials can be designed to control the complex behavior of cells.

Design of biologically active binary protein 2D materials, Nature (2021). DOI: 10.1038/s41586-020-03120-8 , www.nature.com/articles/s41586-020-03120-8

https://phys.org/news/2021-01-proteins-honeycomb-block-uptake-recep...

Comment by Dr. Krishna Kumari Challa on January 7, 2021 at 8:34am

Study explores the effects of immune responses on the aging brain

As human beings age, the functioning of organs gradually deteriorates. While countless past studies have investigated the effects of aging on the human body, brain and on cognition, the neural mechanisms and environmental factors that can accelerate or slow down these effects are not yet fully understood.

The immune system and the nervous system are both known to play a key role in the control of organs in the body. Moreover, past findings suggest that both of these systems change significantly during aging.

Neuroscientific studies have found that as the nervous system ages, the way in which the human body controls immune responses also changes. Nonetheless, how the nervous system's aging process affects immune responses and the consequent impact on the brain's functioning are still poorly understood.

Researchers have recently carried out a study investigating the possible effects of immune responses on the aging brain. Their paper, published in Nature Neuroscience, shows that the deterioration of neuroblasts (i.e., the embryonic cells  from which nerve fibers originate) in the aging brain can increase the toxicity of natural killer cells (NK), which leads to impairments in neurogenesis and cognition. NK cells are a class of blood cells that are part of the human immune system.

"Systemic inflammation escalates during the aging process, but the potential impact of immune and inflammatory responses on brain aging remains unknown.

Researchers now found that immune cells such as NK cells impair neurogenesis and cognitive function during normal brain aging. Immune modulation targeting immune cells (which accumulate in the aged brain) may thus be useful to improve cognition in the aged population.

The recent study carried out by this team of researchers suggests that the accumulation of NK cells in the aging brain can impair the process through which neurons are formed in the brain, known as neurogenesis. In the future, this important finding could inform the development of more effective treatment strategies for improving cognition in older adults.

Neuroblast senescence in the aged brain augments natural killer cell cytotoxicity leading to impaired neurogenesis and cognition. Nature Neuroscience(2020). DOI: 10.1038/s41593-020-00745-w

https://medicalxpress.com/news/2021-01-explores-effects-immune-resp...

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