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Comment by Dr. Krishna Kumari Challa on December 7, 2021 at 10:34am

In their scientific publication, the researchers list the possible explanations for the lack of dark matter one by one. For example, AGC 114905 could have been stripped of dark matter by large nearby galaxies. Mancera Piña: "But there are none. And in the most reputed galaxy formation framework, the so called cold dark matter model, we would have to introduce extreme parameter values that are far beyond the usual range. Also with modified Newtonian dynamics, an alternative theory to cold dark matter, we cannot reproduce the motions of the gas within the galaxy."

According to the researchers, there is one more assumption that could change their conclusions. That is the estimated angle at which they think they are observing the galaxy. "But that angle has to deviate very much from our estimate before there is room for dark matter again," says co-author Tom Oosterloo (ASTRON).

Meanwhile, the researchers are examining a second ultra-diffuse dwarf galaxy in detail. If again observe no trace of dark matter in that galaxy, it will make the case for dark matter poor galaxies even stronger.

The research of Mancera Piña and colleagues is not an isolated case. Earlier, for example, the Dutch American Pieter van Dokkum (Yale University, U.S.) discovered a galaxy with hardly any dark matter. The techniques and measurements of Mancera Piña and colleagues are more robust.

No need for dark matter: resolved kinematics of the ultra-diffuse galaxy AGC 114905 arXiv:2112.00017 [astro-ph.GA] arxiv.org/abs/2112.00017 . Accepted for publication in Monthly Notices of the Royal Astronomical Society.

https://phys.org/news/2021-12-evidence-emerges-dark-matter-free-gal...

Part 2

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Comment by Dr. Krishna Kumari Challa on December 7, 2021 at 10:33am

Evidence emerges for dark-matter free galaxies

An international team of astronomers led by researchers from the Netherlands has found no trace of dark matter in the galaxy AGC 114905, despite taking detailed measurements over a course of forty hours with state-of-the-art telescopes. They will present their findings in Monthly Notices of the Royal Astronomical Society.

discovered six galaxies with little to no dark matter, they were told "measure again, you'll see that there will be dark matter around your galaxy". However, after forty hours of detailed observations using the Very Large Array (VLA) in New Mexico (United States), the evidence for a dark matter-free galaxy only became stronger.

The galaxy in question, AGC 114905, is about 250 million light-years away. It is classified as an ultra-diffuse dwarf galaxy, with the name 'dwarf galaxy' referring to its luminosity and not to its size. The galaxy is about the size of our own Milky Way but contains a thousand times fewer stars. The prevailing idea is that all galaxies, and certainly ultra-diffuse dwarf galaxies, can only exist if they are held together by dark matter.

The researchers collected data on the rotation of gas in AGC 114905 for 40 hours between July and October 2020 using the VLA telescope. Subsequently, they made a graph showing the distance of the gas from the center of the galaxy on the x-axis and the rotation speed of the gas on the y-axis. This is a standard way to reveal the presence of dark matter. The graph shows that the motions of the gas in AGC 114905 can be completely explained by just normal matter.

Part1

Comment by Dr. Krishna Kumari Challa on December 7, 2021 at 9:10am

Scientists discover potential cause of Alzheimer's disease

Prevailing theories posit plaques in the brain cause Alzheimer's disease. New research instead points to cells' slowing ability to clean themselves as the likely cause of unhealthy brain buildup.

Along with signs of dementia, doctors make a definitive Alzheimer's diagnosis if they find a combination of two things in the brain: amyloid plaques and neurofibrillary tangles. The plaques are a buildup of amyloid peptides, and the tangles are mostly made of a protein called tau.

Roughly 20% of people have the plaques, but no signs of dementia. This makes it seem as though the plaques themselves are not the cause.

For this reason, researchers investigated understudied aspects of tau protein. They wanted to understand whether a close examination of tau could reveal more about the mechanism behind the plaques and tangles.

A key but difficult-to-detect difference in the form of tau allowed the scientists to distinguish between people who expressed no outward signs of dementia from those who did. These results have now been published in the Journal of Proteome Research.

Researchers scanned all the proteins in donated brain samples. Those with brain buildup but no dementia had normal tau while a different-handed form of tau was found in those who developed plaques or tangles as well as dementia.

Most proteins in the body have a half-life of less than 48 hours. However, if the protein hangs out too long, certain amino acids can convert into the other-handed isomer.

In general, the process of clearing spent or defective proteins from cells, known as autophagy, slows down in people over the age of 65. 

 Evan E. Hubbard et al, Does Data-Independent Acquisition Data Contain Hidden Gems? A Case Study Related to Alzheimer's Disease, Journal of Proteome Research (2021). DOI: 10.1021/acs.jproteome.1c00558

https://medicalxpress.com/news/2021-11-scientists-potential-alzheim...

Comment by Dr. Krishna Kumari Challa on December 7, 2021 at 8:48am

Researchers develop ice cube that doesn't melt or grow mold

Researchers have developed a new type of cooling cube that could revolutionize how food is kept cold and shipped fresh without relying on ice or traditional cooling packs.

These plastic-free, "jelly ice cubes" do not melt, are compostable and anti-microbial, and prevent cross-contamination.

The cooling cubes contain more than 90 percent water and other components to retain and stabilize the structure. They are soft to the touch like a gelatin dessert and change color depending on temperature. These reusable cubes can be designed or cut to any shape and size needed. You can use it for 13 hours for cooling, collect it, rinse it with water and put it in the freezer to freeze again for the next use.

The jelly ice cubes offer an alternative to traditional ice and could potentially reduce water consumption and environmental impact. They also offer stable temperatures to reduce food spoilage and could be ideal for meal prep companies, shipping businesses and food producers who need to keep items cold.

The application could potentially reduce water consumption in the food supply chain and food waste by controlling microbial contaminations. The research was published in the American Chemical Society's journal, Sustainable Chemistry & Engineering.

Jiahan Zou et al, Sustainable and Reusable Gelatin-Based Hydrogel "Jelly Ice Cubes" as Food Coolant. II: Ideal Freeze–Thaw Conditions, ACS Sustainable Chemistry & Engineering (2021). DOI: 10.1021/acssuschemeng.1c06309

https://phys.org/news/2021-11-ice-cube-doesnt-mold.html?utm_source=...

Comment by Dr. Krishna Kumari Challa on December 7, 2021 at 8:27am

The first international framework on open science was adopted by 193 countries attending UNESCO’s General Conference. By making science more transparent and more accessible, the UNESCO Recommendation on Open Science will make science more equitable and inclusive. 

Through open science, scientists and engineers use open licenses to share their publications and data, software and even hardware more widely. Open science should, thus, enhance international scientific cooperation. 

Open science can be a powerful tool to reduce inequalities between and within countries and further the human right to enjoy and benefit for scientific progress, as stipulated in Article 27 of the Universal Declaration on Human Rights.

Welcome this collaborative international approach. Open science is a great aim. Working together and sharing insights as a global science community is the best way to push the boundaries of knowledge and discovery.

https://www.unesco.org/en/articles/unesco-sets-ambitious-internatio...

Comment by Dr. Krishna Kumari Challa on December 6, 2021 at 12:04pm

Humans Are Doomed to Go Extinct

Habitat degradation, low genetic variation and declining fertility are setting Homo sapiens up for collapse 

Comment by Dr. Krishna Kumari Challa on December 6, 2021 at 12:01pm

A Fusion Reaction Has Generated More Energy Than Absorbed by The Fuel

For the first time, a fusion reaction has achieved a record 1.3 megajoule energy output – and for the first time, exceeding energy absorbed by the fuel used to trigger it.

Inertial confinement fusion involves creating something like a tiny star. It starts with a capsule of fuel, consisting of deuterium and tritium – heavier isotopes of hydrogen. This fuel capsule is placed in a hollow gold chamber about the size of a pencil eraser called a hohlraum.

Then, 192 high-powered laser beams are blasted at the hohlraum, where they are converted into X-rays. These X-rays implode the fuel capsule, heating and compressing it to conditions comparable to those in the center of a star – temperatures in excess of 100 million degrees Celsius (180 million Fahrenheit) and pressures greater than 100 billion Earth atmospheres – turning the fuel capsule into a tiny blob of plasma.

And, just as hydrogen fuses into heavier elements in the heart of a main-sequence star, so too does the deuterium and tritium in the fuel capsule. The whole process takes place in just a few billionths of a second. The goal is to achieve ignition – a point at which the energy generated by the fusion process exceeds the total energy input.

The experiment, conducted on 8 August, fell just short of that mark; the input from the lasers was 1.9 megajoules. But it's still tremendously exciting, because according to the team's measurements, the fuel capsule absorbed over five times less energy than it generated in the fusion process. The result also opens up new avenues for experimental research.

https://meetings.aps.org/Meeting/DPP21/Session/AR01.1

https://www.sciencealert.com/for-the-first-time-a-fusion-reaction-h...

Comment by Dr. Krishna Kumari Challa on December 6, 2021 at 9:20am

The researchers began their investigation into how cells can maintain mitochondrial function without oxygen by using mass spectrometry to measure the quantities of molecules called metabolites that are produced through cellular respiration in both normal and low-oxygen conditions. When cells were deprived of oxygen, researchers noticed a high level of a molecule called succinate.

When you add electrons to oxygen at the end of the electron transport chain, it picks up two protons and becomes water. When you add electrons to fumarate, it becomes succinate. This led the researchers to think that maybe this accumulation of succinate that's occurring could actually be caused by fumarate being used as an electron acceptor, and that this reaction could explain the maintenance of mitochondrial functions in hypoxia.

Usually, the fumarate-succinate reaction runs the other direction in cells—a protein complex called the SDH complex takes away electrons from succinate, leaving fumarate. For the opposite to happen, the SDH complex would need to be running in reverse.

Through a series of assays, however, the researchers were able to ascertain that this complex was indeed running in reverse in cultured cells, largely due to accumulation of a molecule called ubiquinol, which the researchers observed to build up under low-oxygen conditions.

https://phys.org/news/2021-12-tissues-oxygen.html?utm_source=nwlett...

Part 2

Comment by Dr. Krishna Kumari Challa on December 6, 2021 at 9:18am

Some tissues can 'breathe' without oxygen

Humans need oxygen molecules for a process called cellular respiration, which takes place in our cells' mitochondria. Through a series of reactions called the electron transport chain, electrons are passed along in a sort of cellular relay race, allowing the cell to create ATP, the molecule that gives our cells energy to complete their vital functions.

At the end of this chain, two electrons remain, which are typically passed off to oxygen, the "terminal electron acceptor." This completes the reaction and allows the process to continue with more electrons entering the electron transport chain.

In the past, however, scientists have noticed that cells are able to maintain some functions of the electron transport chain, even in the absence of oxygen. "This indicated that mitochondria could actually have partial function, even when oxygen is not the electron acceptor. How does this work? How are mitochondria capable of maintaining these electron inputs when oxygen is not the terminal electron acceptor?"

Scientists  have found the answer to these questions recently. Their research shows that when cells are deprived of oxygen, another molecule called fumarate can step in and serve as a terminal electron acceptor to enable mitochondrial function in this environment. 

The research answers a long-standing mystery in the field of cellular metabolism, and could potentially inform research into diseases that cause low oxygen levels in tissues, including ischemia, diabetes and cancer.

Jessica B. Spinelli et al, Fumarate is a terminal electron acceptor in the mammalian electron transport chain, Science (2021). DOI: 10.1126/science.abi7495

Part 1

Comment by Dr. Krishna Kumari Challa on December 5, 2021 at 12:07pm

Device instantly detects sepsis via sweat

 Every year, millions of  adults develop sepsis, a life-threatening complication that arises when the body has an overwhelming immune response to an infection. According sepsis causes more than 20 percent of all deaths worldwide.

A crucial aspect of treating sepsis is to catch it at an early stage when a patient’s infection is still curable. Current methods to diagnose sepsis, however, rely on tests that can take days to yield results, while early sepsis can turn into full-blown septic shock within only one hour after the first symptoms emerge.

This means that doctors often need to wait for the results of a test, and the results may not even be accurate if the patient developed a condition after the sample was taken.

The students consulted with sepsis survivors, scientists, and clinicians at the University of Rochester Medical Center to design a sepsis-sensing device, which they named “Bio-Spire,” a combination of “biology” and “perspire.” Bio-Spire is a biosensor that continuously monitors the levels of biomarkers in sweat. Unlike blood, sweat is a noninvasive medium to collect, and unlike saliva or urine, biomarkers in sweat can be continuously analyzed. The levels of biomarkers in blood and in sweat are correlated, so changes in the amount of biomarkers in sweat are indicative of changes in the blood.

That is, a change in biomarker levels in a patient’s sweat can signify a deterioration of the patient’s condition—and may signify sepsis.

Doctors use many different tools to diagnose patients, one of which is the presence and concentration of certain biomarkers—molecules such as proteins or sugar that are associated with a particular disease, condition, or biological process. There are several ways to measure biomarker concentrations, including test strips and lab-on-a-chip devices, but many of these approaches only show biomarker concentrations at one specific point in time. These methods can also be expensive, and many take hours to perform.

In order to address this problem, a team of 12 undergraduate students  developed a novel device that instantaneously diagnoses sepsis based on biomarkers in a person’s sweat. The device offers a noninvasive way to monitor sepsis in real-time and uses materials that are environmentally friendly and affordable, making the device easily deployable in low-income countries.

Bio-Spire is designed to collect a tiny amount of sweat from a patient’s skin and wick the sweat past an integrated set of electrodes covered in biomarker detectors. The biomarker detectors consist of short pieces of DNA receptors attached to a small sheet of graphene—an ultra-thin layer of material that is highly conductive. The students synthetically created their own graphene and DNA in an environmentally-friendly manner by using engineered biological components.

When the sleeve-like device is placed on a patient’s arm, biomarkers associated with sepsis bind to the DNA receptors, changing the conductivity of the graphene sheet and triggering an electrical resistance in the electrodes, which is then recorded on a computer. The students created software that displays the concentrations of sepsis biomarkers in real time, permitting health care workers to receive up-to-the-minute updates on a patient’s condition.

https://www.rochester.edu/newscenter/what-is-sepsis-diagnosis-devic...

https://researchnews.cc/news/10312/Rochester-students--award-winnin...

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