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Comment by Dr. Krishna Kumari Challa on November 13, 2020 at 7:06am

Researchers find connection between household chemicals and gut microbiome

A team of researchers for the first time has found a correlation between the levels of bacteria and fungi in the gastrointestinal tract of children and the amount of common chemicals found in their home environment.

The work could lead to better understanding of how these semi-volatile organic compounds may affect human health.

The microbes in our gut, which include a large variety of bacteria and fungi, are thought to affect many processes, from nutrient absorption to our immunity, and an unhealthy microbiome has been implicated in diseases ranging from obesity to asthma and dementia.

In the study, the researchers measured levels of ubiquitous semi-organic compounds in the blood and urine of 69 toddlers and preschoolers and then, using fecal samples, studied the children's gut microbiomes. The semi-volatile organic compounds they measured included phthalates that are used in detergents, plastic clothing such as raincoats, shower curtains, and personal-care products, such as soap, shampoo, and hair spray, as well as per- and polyfluoroalkyl substances (PFASs), which are used in stain- and water-repellent fabrics, coatings for carpets and furniture, nonstick cooking products, polishes, paints, and cleaning products. People are exposed daily to such chemicals in the air and dust in their homes, especially young children who might ingest them by crawling on carpets or frequently putting objects in their mouths.

When the researchers looked at the levels of fungi and bacteria in the gut, they found that children who had higher levels of the chemicals in their bloodstream showed differences in their gut microbiome.

Children with higher levels of PFASs in their blood had a reduction in the amount and diversity of bacteria, while increased levels of phthalates were associated with a reduction in fungi populations.

The correlation between the chemicals and less abundant bacterial organisms was especially pronounced and potentially most concerning.

The researchers also found, surprisingly, that the children who had high levels of chemical compounds in their blood also had in their gut several types of bacteria that have been used to clean up toxic chemicals. Dehalogenating bacteria have been used for bioremediation to degrade persistent halogenated chemicals like dry cleaning solvents from the environment. These bacteria are not typically found in the human gut.

"Finding the increased levels of these type of bacteria in the gut means that, potentially, the gut microbiome is trying to correct itself.

 Courtney M. Gardner et al, Exposures to Semivolatile Organic Compounds in Indoor Environments and Associations with the Gut Microbiomes of Children, Environmental Science & Technology Letters (2020). DOI: 10.1021/acs.estlett.0c00776

https://medicalxpress.com/news/2020-11-household-chemicals-gut-micr...

Comment by Dr. Krishna Kumari Challa on November 13, 2020 at 7:00am

Evolution favours new diseases of 'intermediate' severity

New epidemic diseases have an evolutionary advantage if they are of "intermediate" severity, research shows.

Scientists tested the theory that pathogens (disease-causing organisms) that inflict intermediate levels of harm on their host are the most evolutionarily successful.

found that natural selection favors pathogens of intermediate virulence (how much harm a pathogen causes) at the point the disease emerges in a new host species.

This occurs because virulence and transmission are linked, with virulence arising because pathogens need to exploit hosts to persist, replicate and transmit.

While too-low virulence will be detrimental for pathogens if they cannot transmit, virulence that is too high will also be a disadvantage if infection kills hosts so fast that the pathogen does not have time to transmit.

Over time, pathogens that show intermediate levels of virulence should therefore have an evolutionary advantage.

Camille Bonneaud et al, Experimental evidence for stabilizing selection on virulence in a bacterial pathogen, Evolution Letters (2020). DOI: 10.1002/evl3.203

https://phys.org/news/2020-11-evolution-favors-diseases-intermediat...

Comment by Dr. Krishna Kumari Challa on November 13, 2020 at 6:47am

Tableware made from sugarcane and bamboo breaks down in 60 days

Scientists have designed a set of "green" tableware made from sugarcane  and bamboo that doesn't sacrifice on convenience or functionality and could serve as a potential alternative to plastic cups and other disposable plastic containers. Unlike traditional plastic or biodegradable polymers—which can take as long as 450 years or require high temperatures to degrade—this non-toxic, eco-friendly material only takes 60 days to break down and is clean enough to hold your morning coffee or dinner takeout.

To find an alternative for plastic-based food containers, researchers turned to bamboos and one of the largest food-industry waste products: bagasse, also known as sugarcane pulp. Winding together long and thin bamboo fibers with short and thick bagasse fibers to form a tight network, the team molded containers from the two materials that were mechanically stable and biodegradable. The new green tableware is not only strong enough to hold liquids as plastic does and cleaner than biodegradables made from recycled materials that might not be fully de-inked, but also starts decomposing after being in the soil for 30-45 days and completely loses its shape after 60 days.

The researchers added alkyl ketene dimer (AKD), a widely used eco-friendly chemical in the food industry, to increase oil and water resistance of the molded tableware, ensuring the sturdiness of the product when wet. With the addition of this ingredient, the new tableware outperformed commercial biodegradable food containers, such as other bagasse-based tableware and egg cartons, in mechanical strength, grease resistance, and non-toxicity.

The tableware the researchers developed also comes with another advantage: a significantly smaller carbon footprint. The new product's manufacturing process emits 97% less CO2 than commercially available plastic containers and 65% less CO2 than paper products and biodegradable plastic. 

 Matter, Liu, Luan, and Li et al.: "Biodegradable, Hygienic, and Compostable Tableware from Hybrid Sugarcane and Bamboo Fibers as Plastic Alternative" www.cell.com/matter/fulltext/S2590-2385(20)30558-0 , DOI: 10.1016/j.matt.2020.10.004

https://phys.org/news/2020-11-tableware-sugarcane-bamboo-days.html?...

Comment by Dr. Krishna Kumari Challa on November 12, 2020 at 6:34am

Sugar work: Study finds sugar remodels molecular memory in fruit flies

A high-sugar diet reprograms the taste cells in fruit flies, dulling their sensitivity to sugar and leaving a "molecular memory" on their tongues, according to a study.
Researchers found that high-sugar diets completely remodelled the flies' taste cells, leaving a molecular memory that lasts even when the flies were switched back to healthy diets. The molecular memory of the previous diet could lock animals into a pattern of unhealthy eating behaviour.
When we eat food, it just takes a few bites for it to go away. We don't really think of it being something that could have this kind of lasting effect on our brain. But when the animals were moved to a different food environment, such as a healthy diet, they kept the molecular memory of the high-sugar diet in their cells. This shows the past food environment may influence the future behaviours of the animals.
Specifically, the researchers found that a high-sugar diet reprogrammed cells located in the mouths of fruit flies that sense sweetness, leading them to malfunction. This reprogramming involved an epigenetic regulator called Polycomb Repressive Complex 2.1, or PRC2. Epigenetic regulators are groups of enzymes that can affect how much and whether a gene is expressed by remodelling a material called chromatin. Chromatin comprises the material of chromosomes in everything from plants to humans.
In this case, the research team found the way PRC2 is distributed in the chromatin of neurons that sense sweet taste changes when flies are on a high-sugar diet. They found that this change activates some genes and silences others—specifically, the genes that are involved in detecting sweetness.
So, through this very specific pathway, a high-sugar diet can silence genes required for sweet taste. Even more interesting is that the effect of gene silencing is actually persistent so that even when the animals are removed from the high-sugar diet, the genes associated with taste are still changed and the animals still experience sweet taste defects.

 A. Vaziri el al., "Persistent epigenetic reprogramming of sweet taste by diet," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abc8492

https://phys.org/news/2020-11-sugar-remodels-molecular-memory-fruit...

Comment by Dr. Krishna Kumari Challa on November 12, 2020 at 6:25am

Scientists release genomes of birds representing nearly all avian families

Since the first bird evolved more than 150 million years ago, its descendants have adapted to a vast range of ecological niches, giving rise to tiny, hovering hummingbirds, plunge-diving pelicans and showy birds-of-paradise. Today, more than 10,000 species of birds live on the planet—and now scientists are well on their way to capturing a complete genetic portrait of that diversity. 

 In the Nov. 11 issue of the journal Nature, scientists from the Smithsonian Institution, the University of Copenhagen, BGI-Shenzen, the University of California, Santa Cruz and approximately 100 other institutions report on the genomes of 363 species of birds, including 267 that have been sequenced for the first time. The studied species—from widespread, economically important birds such as the chicken to the lesser known Henderson crake, which lives only on one small island in the Pacific Ocean—represent more than 92% of the world's avian families. The data from the study will advance research on the evolution of birds and aids in the conservation of threatened bird species.

Together, the data constitute a rich genomic resource that is now freely available to the scientific community.

Comparing genomes across bird families will enable B10K researchers and others to explore how particular traits evolved in different birds, as well as to better understand evolution at the molecular level. Ultimately, B10K researchers aim to build a comprehensive avian tree of life that charts the genetic relationships between all modern birds. Such knowledge will not only reveal birds' evolutionary past but will also be vital in guiding conservation efforts in the future.  

Dense sampling of bird diversity increases power of comparative genomics, Nature (2020). DOI: 10.1038/s41586-020-2873-9 , www.nature.com/articles/s41586-020-2873-9  

https://phys.org/news/2020-11-scientists-genomes-birds-avian-famili...

Comment by Dr. Krishna Kumari Challa on November 11, 2020 at 12:08pm

Scientists Just Discovered  over 12,000 New Species of Microbes

Growing microbes in a petri dish is pretty simple – swab basically anything, wipe it on an agar plate, let it sit for a few days in a warm room and presto! You've grown some new furry friends.

But the microbial species you can cultivate in a petri dish are only a tiny fraction of the bacteria, archaea and other microorganisms that would have been picked up by the swab - only the ones suited to the conditions you grew them in.

The overwhelming majority of them do not like the environments we can provide, and therefore won't obediently grow in a petri dish.

Now, an international team of researchers has found 12,556 new species of bacteria and archaea that have never been grown in a lab, using an incredibly cool technique called metagenomics.

"We were able to reconstruct thousands of metagenome-assembled genomes (MAGs) directly from sequenced environmental samples without needing to cultivate the microbes in the lab," said DOE Joint Genome Institute geneticist and first author, Stephen Nayfach.

"What makes this study really stand out from previous efforts is the remarkable environmental diversity of the samples we analysed."

https://www.sciencealert.com/scientists-have-just-uncovered-12-000-...

https://www.nature.com/articles/s41587-020-0718-6

https://phys.org/news/2020-11-scientists-genomes-birds-avian-famili...

Comment by Dr. Krishna Kumari Challa on November 11, 2020 at 12:05pm

What Happens When You Overcharge A Battery Understanding what causes dendrites in lithium-ion batteries could help make the ubiquitous technology safer. https://www.asianscientist.com/2020/11/tech/battery-overcharge-lith...

Comment by Dr. Krishna Kumari Challa on November 11, 2020 at 9:30am

Radioactive: new Marie Curie biopic inspires, but resonates uneasily for women in science

https://theconversation.com/radioactive-new-marie-curie-biopic-insp...

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How memorable melodies can make your research sing

Writing songs for open-mic sessions at a Boston bar helped scientist-songwriter Saurja DasGupta to communicate his research more confidently.

https://www.nature.com/articles/d41586-020-03175-7?utm_source=Natur...

Sci-com using music

"In The Beginning Was RNA": Saurja DasGupta - UChicagoGRAD Three Minute Thesis Competition

Comment by Dr. Krishna Kumari Challa on November 11, 2020 at 9:16am

How do we reduce the risk of animal viruses jumping to humans?

Comment by Dr. Krishna Kumari Challa on November 11, 2020 at 9:03am

Researchers discover two key events that turn normal cells into cancer

More than 100 different cancers can arise all over the body, but two universal metabolic pathways may tie them all together, researchers report in a new study published today online in Cell Metabolism. Researchers have long believed all cancers are governed by a common set of fundamental processes. Exactly what those were, however, has remained elusive.

Having a unifying mechanism could inform new therapeutic approaches to prevent normal cells from transforming into any type of tumour, be it breast, prostate, or colon, for example.

The team discovered how the transformation from a phenotypically normal cell to a cancerous one involves the enhancement of two key elements: antioxidant defense and nucleotide synthesis. Genes associated with cancer, they found, are super charging some cells to fight off oxidative stress and synthesize nucleotides, which cells need to survive and rapidly grow, respectively.

The researchers first overexpressed the gene G6PD, which makes the enzyme glucose-6-phosphate dehydrogenase, in mice and human cells. That enzyme is active in nearly all cells in the body and involved in the normal processing of carbohydrates. They showed that this overexpression alone turned human cells cancerous and led to tumors in the mice.

Next, they analyzed the mechanisms involved in that overexpression to pinpoint what pathways were critical to the transformation. They found that G6PD stimulates production of new NADPH, a crucial co-enzyme for maintaining redox balance (which keeps the cell from being damaged and dying off), as well as more nucleotide precursors to keep them multiplying. Under conditions that elicit oxidative stress, which are often encountered by cancer cells due to their relentless proliferation, often in a wrong place, a normal cell would buckle, but a cancer cell armed with these additions presses on.

The findings also lend further evidence shown in clinical trials and other studies that antioxidants in fact support tumor growth, not decrease it. For a tumor to form, it needs a robust antioxidant defense; giving it more antioxidants provides an ideal environment for it to do that. The findings also provide an explanation for the observation that compounds interfering with nucleotide biosynthesis are among the most successful chemotherapeutic drugs for cancer.

Importantly, the study reveals a molecular framework to better understand the process of oncogenesis and a potential road map for new approaches to treat cancer, the authors said.

Now we can say that the oncogenic transformation comes from two fundamental steps. “Our study also suggests that combining therapeutics that affect both events, some which are already in clinics, would be more effective at preventing normal cells from becoming cancerous.

https://www.pennmedicine.org/news/news-releases/2020/november/penn-...

https://researchnews.cc/news/3504/Penn-researchers-discover-two-key...

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