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Comment by Dr. Krishna Kumari Challa on June 11, 2024 at 10:22am

Study finds fresh water and key conditions for life appeared on Earth a half-billion years earlier than thought

We need two ingredients for life to start on a planet: dry land and (fresh) water. Strictly, the water doesn't have to be fresh, but fresh water can only occur on dry land.

Only with those two conditions met can you convert the building blocks of life, amino acids and nucleic acids into tangible bacterial life that heralds the start of the evolutionary cycle.

The oldest life on Earth left in our fragmented rock record is 3.5 billion years old, with some chemical data showing it may even be as old as 3.8 billion years. Scientists have hypothesized life might be even older, but we have no records of that being the case.

A new study published in Nature Geoscience provides the first evidence of fresh water and dry land on Earth by 4 billion years ago. Knowing when the cradle of life—water and land—first appeared on Earth ultimately provides clues as to how we came to be.

Fresh water is very different from sea water. Obviously, you might say, but how do you know if one or both were present on Earth if you can't actually go back in a time machine?

The answer is in the rock record and chemical signals preserved in that time capsule. Earth is a bit over 4.5 billion years old, and the oldest rocks scientists have found are just a little older than 4 billion years.

To really understand our planet in its first 500 million years, we have to turn to crystals that once came from older rocks and ended up deposited in younger rocks.

Unlike rocks, the oldest preserved crystals go back as far as 4.4 billion years. And the bulk of these super-old crystals comes from one place on Earth: the Jack Hills in Western Australia's midwest.

This is precisely where the researchers of this study went. They dated over a thousand crystals of a mineral called zircon, famed for its extreme resistance to weathering and alteration.

Part 1

Comment by Dr. Krishna Kumari Challa on June 10, 2024 at 7:47am

Does magic really exist?

Comment by Dr. Krishna Kumari Challa on June 10, 2024 at 7:17am

When Water Flows Uphill

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 11:07am

Researchers discover Earth and space share the same turbulence

In a paper published in Geophysical Research Letters, researchers have discovered that the turbulence in the thermosphere exhibits the same physical laws as the wind in the lower atmosphere. Furthermore, wind in the thermosphere predominantly rotates in a cyclonic direction, in that it rotates counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

The findings reveal a new unified principle for the Earth's varied environmental systems and can potentially improve future forecasting of both earth and space weather.

Facundo L. Poblet et al, Third‐Order Structure Functions of Zonal Winds in the Thermosphere Using CHAMP and GOCE Observations, Geophysical Research Letters (2024). DOI: 10.1029/2024GL108367

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 11:02am

The shells in this paper consist of a thin inner layer of positive mass and a thin outer layer of negative mass; the total mass of both layers—which is all one could measure, mass-wise—is exactly zero, but when a star lies on this shell it experiences a large gravitational force pulling it towards the center of the shell.
As gravitational force fundamentally involves the warping of space-time itself, it enables all objects to interact with each other, whether they have mass or not. Massless photons, for example, have been confirmed to experience gravitational effects from astronomical objects.
Gravitational bending of light by a set of concentric singular shells comprising a galaxy or cluster is due to a ray of light being deflected slightly inwards—that is, towards the center of the large-scale structure, or the set of shells—as it passes through one shell.
The sum total effect of passage through many shells is a finite and measurable total deflection which mimics the presence of a large amount of dark matter in much the same way as the velocity of stellar orbits.

Both the deflection of light and stellar orbital velocities is the only means by which one gauges the strength of the gravitational field in a large-scale structure, be it a galaxy or a cluster of galaxies. The contention of this paper is that at least the shells it posits are massless. There is then no need to perpetuate this seemingly endless search for dark matter.

Richard Lieu, The binding of cosmological structures by massless topological defects, Monthly Notices of the Royal Astronomical Society (2024). DOI: 10.1093/mnras/stae1258

Part 2

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Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 11:00am

Researcher suggests that gravity can exist without mass, mitigating the need for hypothetical dark matter

Dark matter is a hypothetical form of matter that is implied by gravitational effects that can't be explained by general relativity unless more matter is present in the universe than can be seen. It remains virtually as mysterious as it was nearly a century ago when first suggested by Dutch astronomer Jan Oort in 1932 to explain the so-called "missing mass" necessary for things like galaxies to clump together.

Now Dr. Richard Lieu at The University of Alabama in Huntsville (UAH) has published a paper in the Monthly Notices of the Royal Astronomical Society that shows, for the first time, how gravity can exist without mass, providing an alternative theory that could potentially mitigate the need for dark matter.  

The researcher contends the "excess" gravity necessary to bind a galaxy or cluster together could be due instead to concentric sets of shell-like topological defects in structures commonly found throughout the cosmos that were most likely created during the early universe when a phase transition occurred. A cosmological phase transition is a physical process where the overall state of matter changes together across the entire universe.

It is unclear presently what precise form of phase transition in the universe could give rise to topological defects of this sort.

Topological effects are very compact regions of space with a very high density of matter, usually in the form of linear structures known as cosmic strings, although 2D structures such as spherical shells are also possible.

Part 1

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 9:21am

Highlights of the study:

• •An early study to detect microplastics in semen from a general population cohort
• •Eight MP polymer types were identified, with PS, PE, and PVC most prevalent.
• •Raman microspectroscopy enabled sub-micron microplastic characterization.
• •PS and PVC correlated with differential effects on sperm motility.

• As widespread environmental pollution, MPs/NPs raise concerns about reproductive toxicity.

• •

  Infertility affects 15 % couples globally, with environmental factors playing a significant role.

• •

  Limited understanding of MPs/NPs effects on testes and ovaries necessitates further research.

• •

  Contaminants carried by particles may synergistically contribute to reproductive toxicity.

https://www.sciencedirect.com/science/article/pii/S0048969723048830

Part 2

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 9:05am

Microplastics found in every semen sample tested by research team
A team of public health researchers affiliated with multiple institutions in China has found microplastics in the semen of every sample they tested. In their study, published in the journal Science of the Total Environment, the group looked for microplastics in semen samples obtained from 36 healthy adult men.

Prior research has shown that microplastics are nearly everywhere, found on mountaintops, remote islands in the upper atmosphere and the depths of the world's oceans. They have also been found in every organ in the human body.

In a recent discovery, scientists found that the average person consumes plastic in amounts equal to about one credit card every week. The researchers note that plastics can enter the body in multiple ways, such as through drinking from water bottles, breathing air particulates, or eating food heated in plastic containers. They further note that it is now practically impossible for people to avoid ingesting microplastics.

The health impacts remain unknown, but many scientists around the world are looking into it, suspecting microplastic ingestion may be behind many inflammatory diseases.
In this new effort, the research team wondered if ingested microplastics might be behind the global drop in fertility rates. To find out, they recruited 36 healthy adult males living in the city of Jinan, in the eastern part of China, who did not work in the plastics industry—each donated a sample of semen for testing.

Each of the samples was prepared by mixing it with a chemical solution then filtered for analysis by a team member using a microscope. The researchers found microplastics in every sample. They also found eight types of plastics, the most common of which was polystyrene, which is commonly used in packaging foam.
The team also found lower sperm motility in the semen samples containing polyvinyl chloride plastic bits, a finding that may help explain the decline in fertility rates.

Ning Li et al, Prevalence and implications of microplastic contaminants in general human seminal fluid: A Raman spectroscopic study, Science of The Total Environment (2024). DOI: 10.1016/j.scitotenv.2024.173522

Comment by Dr. Krishna Kumari Challa on June 8, 2024 at 6:56am

Timing drug administration to endogenous circadian rhythms may enhance treatment efficacy

Taking blood pressure medication at a time that aligns with your personal chronotype – the way your body's circadian rhythm affects when you go to sleep and get up – could help to protect the heart against the risk of heart attack, a new study shows.

It may be beneficial for night owls to take their medication in the evening, and for early birds to take it in the morning. These timings seem to offer some protection against the risks associated with BP (also known as hypertension). The international team of researchers behind the new study looked at records for more than 5,300 individuals, who answered questions about their chronotype, before being randomly split into groups and instructed to take their blood pressure meds at different times. Participants were then monitored over several months. These results are exciting because they could represent a paradigm shift in the treatment of hypertension. This research has now shown for the first time that considering chronotype when deciding [the] dosing time of antihypertensives – [a strategy called] personalized chronotherapy – could reduce the risk of heart attack. Each person's circadian rhythm (24-hour biological cycle) varies slightly, based on genetics and other factors. These rhythms are well known for influencing our sleep patterns, but they also help to dictate body temperature, hormones, metabolism – and, importantly for this study, BP levels. If blood pressure cycles up and down throughout the day, the time that medications are taken might matter, the researchers hypothesized.

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(24)...

Comment by Dr. Krishna Kumari Challa on June 7, 2024 at 7:23am

Bird flu in cows could spread through milk
Astonishing amounts of H5N1 virus have been found in the raw milk of cows infected with avian influenza. The virus can survive for hours in splattered milk. This reinforces that the milking process is probably driving transmission among cows and might be spreading the virus to humans. The fact that H5N1 doesn’t seem to spread through airborne particles is good news. It means changes to milking procedures — such as disinfecting equipment between cows and protective equipment to farm workers — could help to bring the outbreak under control.

Nature | 5 min read
Reference: bioRxiv preprint & medRxiv preprint (not peer reviewed)

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