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Comment by Dr. Krishna Kumari Challa on August 9, 2021 at 11:00am

Lake Huron sinkhole surprise: The rise of oxygen on early Earth linked to changing planetary rotation rate

The rise of oxygen levels early in Earth's history paved the way for the spectacular diversity of animal life. But for decades, scientists have struggled to explain the factors that controlled this gradual and stepwise process, which unfolded over nearly 2 billion years.

Now an international research team is proposing that increasing day length on the early Earth—the spinning of the young planet gradually slowed over time, making the days longer—may have boosted the amount of oxygen released by photosynthetic cyanobacteria, thereby shaping the timing of Earth's oxygenation.

Their conclusion was inspired by a study of present-day microbial communities growing under extreme conditions at the bottom of a submerged Lake Huron sinkhole, 80 feet below the water's surface. The water in the Middle Island Sinkhole is rich in sulfur and low in oxygen, and the brightly colored bacteria that thrive there are considered good analogs for the single-celled organisms that formed mat-like colonies billions of years ago, carpeting both land and seafloor surfaces.

The researchers show that longer day length increases the amount of oxygen released by photosynthetic microbial mats. That finding, in turn, points to a previously unconsidered link between Earth's oxygenation history and its rotation rate. While the Earth now spins on its axis once every 24 hours, day length was possibly as brief as 6 hours during the planet's infancy.

Possible link between Earth's rotation rate and oxygenation, Nature Geoscience (2021). DOI: 10.1038/s41561-021-00784-3 , www.nature.com/articles/s41561-021-00784-3

https://phys.org/news/2021-08-lake-huron-sinkhole-oxygen-early.html...

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

Covid-19 patient develops rare white fungus abscess in brain after recovery

The Covid-19 patient complained of weakness in limbs and difficulty in speech following recovery from the viral disease.

A patient who recovered from the coronavirus disease (Covid-19) in Hyderabad reportedly developed a rare case of white fungus or Aspergillus forming an abscess in the brain.

According to reports, the patient who recovered from the viral disease in May complained of weakness in limbs and difficulty in speech. When doctors conducted a scan of the patient’s brain, they found clot-like formations that did not reduce despite medication. It was only after surgery was conducted that the doctors detected that the white fungus had formed an abscess in the brain.

Doctors say while inflammation of the brain by Aspergillus is common instances of white fungus forming an abscess, especially in Covid-19 patients, is extremely rare.

A senior neurosurgeon of Hyderabad-based Sunshine Hospitals, Dr P Ranganadham, said while fungal infections have been found in Covid-19 patients who are diabetic, in this case, although the patient has a history of high blood pressure there was no presence of diabetes.

“The paranasal sinuses are clear indicating that white fungus had not entered the brain through the nose unlike black fungus,” the specialist doctor said.

Elaborating on the condition of the patient that led to the rare discovery, Dr Ranganadham, who performed the surgery on the patient, said, the patient complained of weakness in the limb and difficulty in speech on the sixth day following hospitalisation with symptoms of Covid-19 virus, at a time when the second wave of the pandemic was at its peak. A brain scan revealed a large lesion in the left part and two small lesions in other areas.

The doctor said the patient was initially treated for haematoma, however, when another MRI of the brain was conducted it was found that the lesion had increased in size with dense and well-defined margins.

The doctor elaborated that the smaller lesions remained unchanged in size. Following surgery, the doctors “found a well-encapsulated abscess containing soft necrotic material, separate from normal brain.”

The medical team working in the case conducted a pathological analysis of the abscess and found it to be a case of white fungus infection, also known as Aspergillosis in medical terms.

Dr Ranganadham said the Aspergillosis of the central nervous system was caused after the white blood cells of the brain were invaded by the white fungus.

https://www.hindustantimes.com/india-news/covid19-white-fungus-brai...

Comment by Dr. Krishna Kumari Challa on August 8, 2021 at 12:49pm

Scientists Identify Extremely Tough Bacterial Species That Thrive Inside Concrete

Some types of bacteria are hardy enough to survive in the most inhospitable of conditions – and that includes concrete, as a new study proves. Not only can microbes survive in this dry, inhospitable building material, they can actually thrive there too.

Research shows that bacteria could provide early warnings of moisture-induced alkali-silica reactions (or 'concrete cancer') that can lead to structural deficiencies. Further down the line, we might even be able to harness bacteria to repair damage to bridges and roads.

While previous studies had already established that bacteria are able to make their homes inside concrete, here the scientists wanted to take a closer look at which microbes were present and how their communities might change over time.

After regular monitoring over two years on the roof of the lab, the most common bacteria discovered in the DNA analysis of the samples were Proteobacteria, Firmicutes, and Actinobacteria. Around 50-60 percent of the bacteria probably came from the raw materials, the researchers say, especially gravel.

The team observed that bacterial diversity dropped over time, though some types of bacteria had 'bounces' as the seasons changed – perhaps an indication that the availability of food sources was changing as well.

It's possible they're eating the dead bodies of other microbes. If there's nothing to eat, some of them can form spores or form a dormant cell type and do nothing until it rains, then eat as much as they can and go dormant again.

As some bacteria can produce calcium carbonate – which is suitable for filling in concrete cracks and pores – there's a hope that these microorganisms could be used to help repair buildings and infrastructure, though that sort of application is a long way off.

The researchers think  the microbes are not damaging the concrete.

https://journals.asm.org/doi/10.1128/mSystems.01153-20

https://www.sciencealert.com/some-bacteria-are-so-tough-they-can-gr...

Comment by Dr. Krishna Kumari Challa on August 8, 2021 at 12:36pm

Menopause breakthrough as scientists find genes to delay ageing process ( Game News )

Comment by Dr. Krishna Kumari Challa on August 8, 2021 at 12:27pm

See how aerosol particles escape from musical instruments

https://www.sciencenews.org/article/coronavirus-covid-music-wind-in...

Comment by Dr. Krishna Kumari Challa on August 8, 2021 at 11:32am

Sunscreen Chemistry and Action

Comment by Dr. Krishna Kumari Challa on August 8, 2021 at 11:18am

Organ transplant recipients significantly protected by COVID-19 vaccination

 In a Brief Communication, published July 29, 2021 in the journal Transplant Infectious Disease, a team of physician-scientists.

found that solid organ transplant recipients who were vaccinated experienced an almost 80 percent reduction in the incidence of symptomatic COVID-19 compared to unvaccinated counterparts during the same time. Persons who have received an organ transplant are considered to be at increased risk for COVID-19 and for a severe outcome because their immune systems are necessarily suppressed to ensure their transplants are successful and lasting.

These new findings offer strong evidence that getting vaccinated provides significant protection even to the immuno-suppressed people.

During the study period, there were 65 diagnosed cases of COVID-19 among the organ recipients: four among fully vaccinated individuals and 61 among the controls (two involving partially vaccinated individuals). There were no deaths among the breakthrough COVID-19 cases, but two among the 61 control cases.

it demonstrates real world clinical effectiveness of COVID-19 vaccination in a vulnerable population. Second, the effectiveness is better than expected, given that studies have found that only about half of solid organ transplant recipients develop detectable anti-spike antibodies after vaccination.

https://researchnews.cc/news/8207/Organ-transplant-recipients-signi...

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Comment by Dr. Krishna Kumari Challa on August 8, 2021 at 11:09am

 Machu Picchu older than previously thought

Machu Picchu, the famous 15th-century Inca site in southern Peru, is up to several decades older than previously thought, according to a new study .

Until now, estimates of Machu Picchu's antiquity and the length of its occupation were based on contradictory historical accounts written by Spaniards in the period following the Spanish conquest.

Researchers used  used accelerator mass spectrometry (AMS)—an advanced form of radiocarbon dating—to date human remains recovered during the early 20th century at the monumental complex and onetime country estate of Inca Emperor Pachacuti located on the eastern face of the Andes Mountains.

Their findings, published in the journal Antiquity, reveal that Machu Picchu was in use from about A.D. 1420 to A.D. 1530—ending around the time of the Spanish conquest—making the site at least 20 years older than the accepted historical record suggests and raising questions about our understanding of Inca chronology.

Historical sources dating from the Spanish invasion of the Inca Empire indicate that Pachacuti seized power in A.D. 1438 and subsequently conquered the lower Urubamba Valley where Machu Picchu is located. Based on those records, scholars have estimated that the site was built after A.D. 1440, and perhaps as late as A.D. 1450, depending on how long it took Pachacuti to subdue the region and construct the stone palace.

The AMS technique can date bones and teeth that contain even small amounts of organic material, expanding the pool of remains suitable for scientific analysis. For this study, the researchers used it to analyze human samples from 26 individuals that were recovered from four cemeteries at Machu Picchu in 1912 during excavations. The bones and teeth used in the analysis likely belonged to retainers, or attendants, who were assigned to the royal estate, the study states. The remains show little evidence of involvement in heavy physical labor, such as construction, meaning that they likely were from the period when the site functioned as a country palace, not when it was being built, the researchers said.

The AMS testing indicates that the historical timeline is inaccurate. This is the first study based on scientific evidence to provide an estimate for the founding of Machu Picchu and the length of its occupation, giving us a clearer picture of the site's origins and history.

The finding suggests that Pachacuti, whose reign set the Inca on the path to becoming pre-Columbian America's largest and most powerful empire, gained power and began his conquests decades earlier than textual sources indicate.

The results suggest that the discussion of the development of the Inca empire based primarily on colonial records needs revision. Modern radiocarbon methods provide a better foundation than the historical records for understanding Inca chronology.

https://www.cambridge.org/core/journals/antiquity/article/new-ams-d...

https://researchnews.cc/news/8221/Study--Machu-Picchu-older-than-ex...

Comment by Dr. Krishna Kumari Challa on August 7, 2021 at 1:36pm

Freeze-Dried Mouse Sperm Sent by Postcard Produces Baby Mice

Rather than relying on samples that need to be shipped in glass vials and on ice, researchers have developed a new method that allows mouse sperm to be sent easily at room temperature using standard mail delivery.

The new method, detailed in a study published today (August 5) in iScience, builds on the team’s previous work, which involved sending dehydrated mouse sperm stored in glass ampoules to the International Space Station to study how radiation affects mammalian cells. Drying the samples, the authors say, does away with the need for cold storage, and they’ve since refined the method further so that they can store sperm from thousands of different mouse strains in a single three-ring binder.

https://www.cell.com/iscience/fulltext/S2589-0042(21)00783-5?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004221007835%3Fshowall%3Dtrue

https://www.the-scientist.com/news-opinion/freeze-dried-mouse-sperm...

Comment by Dr. Krishna Kumari Challa on August 7, 2021 at 12:06pm

Microbes engineered to convert sugar into a chemical found in tires

The future environmental footprint of the tire industry could be substantially shrunk thanks to a new ecofriendly way found by researchers that harnesses bacteria to make a chemical used in synthetic rubber.

Each year, factories around the world churn out more than 12 million metric tons of the organic chemical 1,3-butadiene, which is used in tires, adhesives, sealants and other plastic and rubber products. They produce it by an energy-intensive process that relies on petroleum, which contributes to climate change.

Scientists have tried for many years to create 1,3-butadiene from more environmentally friendly starting materials by using specially designed microbes. But no one had previously succeeded in transforming a simple sugar such as glucose into the chemical in one easy step.

Now, by engineering bacteria to convert glucose into 1,3-butadiene,  researchers have devised a sustainable approach to rubber and plastic production. They constructed a novel artificial metabolic pathway and produced 1,3-butadiene directly from a renewable source—glucose. They first engineered a bacterial enzyme that could convert a biological compound that can be developed from glucose into 1,3-butadiene . The researchers then modified a strain of the bacterium Escherichia coli to use this enzyme and produce the chemical. Since 1,3-butadiene is a gas at room temperature, it can be easily captured as the bacteria continue to divide and grow.

Yutaro Mori et al, Direct 1,3-butadiene biosynthesis in Escherichia coli via a tailored ferulic acid decarboxylase mutant, Nature Communications (2021). DOI: 10.1038/s41467-021-22504-6

https://phys.org/news/2021-08-microbes-sugar-chemical.html?utm_sour...

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