Tag Archives: scientific inquiry

Looking for Signs of Dark Matter Over Antarctica

Dark Matter Proof Found Over Antarctica?

High-energy electrons captured over Antarctica could reveal the presence of a nearby but mysterious astrophysical object that’s bombarding Earth with cosmic rays, researchers say. Or the electrons may be the long-awaited physical evidence of elusive dark matter.

Either way, the unusual particles are exciting for astrophysicists, who say they could someday confirm or deny decades of unproven theories. “In the first case, we have now seen for the first time a nearby source of cosmic rays.
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Cosmic rays are not beams per se but are any protons, electrons, and other subatomic particles that careen toward Earth from a variety of sources, including the supernova explosions that mark the deaths of stars.

Most of the cosmic electrons that reach Earth are low-energy, because the highest-energy ones fizzle the fastest and don’t last long enough to get here.

How Bleach Kills Bacteria

Developed more than 200 years ago and found in households around the world, chlorine bleach is among the most widely used disinfectants, yet scientists never have understood exactly how the familiar product kills bacteria. In fact, Hypochlorite, the active ingredient of household bleach, attacks essential bacterial proteins, ultimately killing the bugs.

“As so often happens in science, we did not set out to address this question,” said Jakob, an associate professor of molecular, cellular and developmental biology. “But when we stumbled on the answer midway through a different project, we were all very excited.”

Jakob and her team were studying a bacterial protein known as heat shock protein 33 (Hsp33), which is classified as a molecular chaperone. The main job of chaperones is to protect proteins from unfavorable interactions, a function that’s particularly important when cells are under conditions of stress, such as the high temperatures that result from fever.

“At high temperatures, proteins begin to lose their three-dimensional molecular structure and start to clump together and form large, insoluble aggregates, just like when you boil an egg,” said lead author Jeannette Winter, who was a postdoctoral fellow in Jakob’s lab. And like eggs, which once boiled never turn liquid again, aggregated proteins usually remain insoluble, and the stressed cells eventually die.

Jakob and her research team figured out that bleach and high temperatures have very similar effects on proteins. Just like heat, the hypochlorite in bleach causes proteins to lose their structure and form large aggregates.

These findings are not only important for understanding how bleach keeps our kitchen countertops sanitary, but they may lead to insights into how we fight off bacterial infections. Our own immune cells produce significant amounts of hypochlorite as a first line of defense to kill invading microorganisms. Unfortunately, hypochlorite damages not just bacterial cells, but ours as well. It is the uncontrolled production of hypochlorite acid that is thought to cause tissue damage at sites of chronic inflammation.

How did studying the protein Hsp33 lead to the bleach discovery? The researchers learned that hypochlorite, rather than damaging Hsp33 as it does most proteins, actually revs up the molecular chaperone. When bacteria encounter the disinfectant, Hsp33 jumps into action to protect bacterial proteins against bleach-induced aggregation.

“With Hsp33, bacteria have evolved a very clever system that directly senses the insult, responds to it and increases the bacteria’s resistance to bleach,” Jakob said.

Genes Counter a Bacterial Attack

Gene against bacterial attack unravelled

Humans have an innate defence system against deadly bacteria. However, how the step from gene to anti-bacterial effect occurs in the body is not yet known. To date, B. Pseudomallei, a bacterium suitable for bioweapons, had managed to elude medics. It can remain hidden in the human body for many years without being detected by the immune system. The bacteria can suddenly become activated and spread throughout the body, resulting in the patient dying from blood poisoning. AMC physician Joost Wiersinga and the Laboratory for Experimental Internal Medicine discovered which gene-protein combination renders the lethal bacteria B. pseudomallei harmless.

Wiersinga focussed on the so-called Toll-like receptors. These are the proteins that initiate the fight against pathogens. There are currently ten known Toll-like receptors which are located on the outside of immune cells, our body’s defence system. The toll-like receptors jointly function as a 10-figure alarm code. Upon coming into contact with the immune cell each bacterium enters its own Toll code. For known pathogens this sets off an alarm in the immune system and the defence mechanism is activated. Yet B. pseudomallei fools the system by entering the code of a harmless bacterium. As a result the body’s defence system remains on standby.

Yet some people are resistant: they become infected but not ill. Wiersinga found a genetic cause for this resistance. He discovered which toll receptor can fend off B. pseudomallei. He did this by rearing mice DNA in which the gene for Toll2 production was switched on and off. ‘The group where the gene for Toll2 was switched off, survived the bacterial infection’, says Wiersinga. ‘The other receptor that we investigated, Toll4, had no effect – even though for the past ten years medics had regarded this as the most important receptor.’ The ultimate aim of this study is to develop a vaccine.

PLoS paper: MyD88 Dependent Signaling Contributes to Protective Host Defense against Burkholderia pseudomallei

Magnetic Portals Connect Sun and Earth

Magnetic Portals Connect Sun and Earth by Dr. Tony Phillips

During the time it takes you to read this article, something will happen high overhead that until recently many scientists didn’t believe in. A magnetic portal will open, linking Earth to the sun 93 million miles away. Tons of high-energy particles may flow through the opening before it closes again, around the time you reach the end of the page.

“It’s called a flux transfer event or ‘FTE,'” says space physicist David Sibeck of the Goddard Space Flight Center. “Ten years ago I was pretty sure they didn’t exist, but now the evidence is incontrovertible.”
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Researchers have long known that the Earth and sun must be connected. Earth’s magnetosphere (the magnetic bubble that surrounds our planet) is filled with particles from the sun that arrive via the solar wind and penetrate the planet’s magnetic defenses. They enter by following magnetic field lines that can be traced from terra firma all the way back to the sun’s atmosphere.

“We used to think the connection was permanent and that solar wind could trickle into the near-Earth environment anytime the wind was active,” says Sibeck. “We were wrong. The connections are not steady at all. They are often brief, bursty and very dynamic.”
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On the dayside of Earth (the side closest to the sun), Earth’s magnetic field presses against the sun’s magnetic field. Approximately every eight minutes, the two fields briefly merge or “reconnect,” forming a portal through which particles can flow. The portal takes the form of a magnetic cylinder about as wide as Earth.

See more posts on scientific inquiry and scientists advancing our understanding of how things work.

Static Stretching Decreases Muscle Strength

Stretching: The Truth

Researchers now believe that some of the more entrenched elements of many athletes’ warm-up regimens are not only a waste of time but actually bad for you. The old presumption that holding a stretch for 20 to 30 seconds – known as static stretching – primes muscles for a workout is dead wrong. It actually weakens them.
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A well-designed warm-up starts by increasing body heat and blood flow.
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To raise the body’s temperature, a warm-up must begin with aerobic activity, usually light jogging. Most coaches and athletes have known this for years.
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Athletes who need to move rapidly in different directions, like soccer, tennis or basketball players, should do dynamic stretches that involve many parts of the body. “Spider-Man” is a particularly good drill: drop onto all fours and crawl the width of the court, as if you were climbing a wall.

Toward a More Open Scientific Culture

Michael Nielsen wrote a great post, The Future of Science, which is also the topic of a book he is writing. He discusses how scientific advancement has often been delayed as those making discoveries did not share them openly. And how 300 years ago scientific journals and reward systems created ways for scientists to be rewarded for publication. And he continues with the need for the process to again change and promote more open sharing of scientific knowledge, which I agree with and have written about previously: Publishers Continue to Fight Open Access to Science, Science Journal Publishers Stay Stupid, The Future of Scholarly Publication, etc..

Why were Hooke, Newton, and their contemporaries so secretive? In fact, up until this time discoveries were routinely kept secret.
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This cultural transition was just beginning in the time of Hooke and Newton, but a little over a century later the great physicist Michael Faraday could advise a younger colleague to “Work. Finish. Publish.” The culture of science had changed so that a discovery not published in a scientific journal was not truly complete. Today, when a scientist applies for a job, the most important part of the application is their published scientific papers.

This has been a great advance. Now we need to continue that advance to use the internet to make that publication open and increase the advantage of shared knowledge to society.

The adoption of the journal system was achieved by subsidizing scientists who published their discoveries in journals. This same subsidy now inhibits the adoption of more effective technologies, because it continues to incentivize scientists to share their work in conventional journals, and not in more modern media.
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This means: making many more types of content available than just scientific papers; allowing creative reuse and modification of existing work through more open licensing and community norms; making all information not just human readable but also machine readable; providing open APIs to enable the building of additional services on top of the scientific literature, and possibly even multiple layers of increasingly powerful services. Such extreme openness is the ultimate expression of the idea that others may build upon and extend the work of individual scientists in ways they themselves would never have conceived.
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To create an open scientific culture that embraces new online tools, two challenging tasks must be achieved: (1) build superb online tools; and (2) cause the cultural changes necessary for those tools to be accepted.

I agree we need to take advantage of the new possibilities to advance the practice of science. His full post is well worth reading.

Yogurts Used to Combat Superbugs

Yoghurts used to combat superbugs

Dieticians at Addenbrooke’s have said evidence suggested the yoghurt might cut the risk of contracting C.diff. Caroline Heyes, dietetic services manager at Addenbrooke’s hospital, said: “Probiotic yoghurts may play a role in preventing C.difficile infection so we have been running a pilot on three of the care of the elderly wards for six months.
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“We can’t say for sure how much of that benefit is down to the yoghurt and how much they are down to a whole range of infection control procedures that the hospital has in place such as the deep cleaning programme, the bare-below-the-elbow programme, and the increased isolation procedures,” Ms Heyes said.

Vampire Moth Discovered

Entomologist Jennifer Zaspel at the University of Florida in Gainesville said the discovery suggests the moth population could be on an “evolutionary trajectory” away from other C. thalictri populations.

In January, she will compare the Russian population’s DNA to that of other populations and other species to confirm her suspicions. “Based on geography, based on behavior, and based on a phenotypic variation we saw in the wing pattern, we can speculate that this represents something different, something new,” Zaspel said.
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Only male moths exhibit blood feeding, she noted, raising the possibility that as in some species of butterflies and other moths, the Russian moths do it to pass on salt to females during copulation.

“There is no evidence it prolongs the life of the male, or anything like that,” she said. “So we suspect that it is probably going to the female.” The sexual gift, she said, would provide a nutritional boost to young larvae that feed on leaf-rich, but sodium-poor, diets.

Waste from Gut Bacteria Helps Host Control Weight

A single molecule in the intestinal wall, activated by the waste products from gut bacteria, plays a large role in controlling whether the host animals are lean or fatty, a research team, including scientists from UT Southwestern Medical Center, has found in a mouse study.

When activated, the molecule slows the movement of food through the intestine, allowing the animal to absorb more nutrients and thus gain weight. Without this signal, the animals weigh less.

The study shows that the host can use bacterial byproducts not only as a source of nutrients, but also as chemical signals to regulate body functions. It also points the way to a potential method of controlling weight, the researchers said.

“It’s quite possible that blocking this receptor molecule in the intestine might fight a certain kind of obesity by blocking absorption of energy from the gut,” said Dr. Masashi Yanagisawa, professor of molecular genetics at UT Southwestern and a senior co-author of the study, Proceedings of the National Academy of Sciences, open access: Effects of the gut microbiota on host adiposity are modulated by the short-chain fatty-acid binding G protein-coupled receptor, Gpr41.

Humans, like other animals, have a large and varied population of beneficial bacteria that live in the intestines. The bacteria break up large molecules that the host cannot digest. The host in turn absorbs many of the resulting small molecules for energy and nutrients.

In the Big Fat Lie I mentioned some related ideas:

It also makes perfect sense that our bodies evolved to store energy for worse times (and some of us have bodies better at doing that). Now we are in a new environment where (at least for many people alive today) finding enough calories is not going to be a problem so it would be nice if we could tell our bodies to get less efficient at storing fat

This research seems to be looking for a similar way to attack the obesity epidemic: reduce the efficiency of our bodies converting potential energy in the food we eat to energy we use or store. If we can make that part of the solution that will be nice. So far the reduction in our activity and increase in food intake have not been getting good results. And efforts to increase (from our current low levels) activity and reduce food intake have not been very effective.
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Nobel Prize in Physiology or Medicine 2008

The Nobel Prize in Physiology or Medicine for 2008 with one half to Harald zur Hausen for his discovery of “human papilloma viruses causing cervical cancer” and the other half jointly to FranÃ§oise BarrÃ©-Sinoussi and Luc Montagnier for their discovery of “human immunodeficiency virus.”

Harald zur Hausen went against current dogma and postulated that oncogenic human papilloma virus (HPV) caused cervical cancer, the second most common cancer among women. He realized that HPV-DNA could exist in a non-productive state in the tumours, and should be detectable by specific searches for viral DNA. He found HPV to be a heterogeneous family of viruses. Only some HPV types cause cancer. His discovery has led to characterization of the natural history of HPV infection, an understanding of mechanisms of HPV-induced carcinogenesis and the development of prophylactic vaccines against HPV acquisition.

FranÃ§oise BarrÃ©-Sinoussi and Luc Montagnier discovered human immunodeficiency virus (HIV). Virus production was identified in lymphocytes from patients with enlarged lymph nodes in early stages of acquired immunodeficiency, and in blood from patients with late stage disease. They characterized this retrovirus as the first known human lentivirus based on its morphological, biochemical and immunological properties. HIV impaired the immune system because of massive virus replication and cell damage to lymphocytes. The discovery was one prerequisite for the current understanding of the biology of the disease and its antiretroviral treatment.

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