Tag Archives: scientific inquiry

Amazon Molly Fish are All Female

A fish species, which is all female, has survived for 70,000 years without reproducing sexually, experts believe.
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The species, found in Texas and Mexico, interacts with males of other species to trigger its reproduction process. The offspring are clones of their mother and do not inherit any of the male’s DNA. Typically, when creatures reproduce asexually, harmful changes creep into their genes over many generations.
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One theory is that the fish may occasionally be taking some of the DNA from the males that trigger reproduction, in order to refresh their gene pool.

Dr Laurence Loewe, of the university’s School of Biological Sciences, said: “What we have shown now is that this fish really has something special going on and that some special tricks exist to help this fish survive. “Maybe there is still occasional sex with strangers that keeps the species alive. Future research may give us some answers.”

He added that their findings could also help them understand more about how other creatures operate. “I think one of the interesting things is that we are learning more about how other species might use these tricks as well,” he said. “It might have a more general importance.”

Sudden Oak Death

Sudden Oak Death pathogen is evolving, says new study that reconstructs the epidemic

The pathogen responsible for Sudden Oak Death first got its grip in California’s forests outside a nursery in Santa Cruz and at Mt. Tamalpais in Marin County before spreading out to eventually kill millions of oaks and tanoaks along the Pacific Coast, according to a new study led by researchers at the University of California, Berkeley. It provides, for the first time, evidence of how the epidemic unfolded in this state.
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The study, scheduled to appear later this month in the online early edition of the journal Molecular Ecology, also shows that the pathogen is currently evolving in California, with mutant genotypes appearing as new areas are infested.
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The most likely scenario, said Garbelotto, is that the pathogen arrived in California through the nursery trade, and that it then spread from the nursery in Santa Cruz to trees bordering the facility. While the site at Mt. Tamalpais is not adjacent to a nursery, there is anecdotal evidence of frequent use of ornamental plants from nurseries in landscaping projects in the area, said Garbelotto.

Matter-Antimatter Split Hints at Physics Breakdown

Nature may have handed scientists a new clue in a longstanding mystery: how matter beat out antimatter for dominance of the universe. Early data from twin experiments at the Tevatron, the world’s reigning particle accelerator at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Ill., suggest an unexpected chink in the hugely successful standard model of particle physics.

The twist comes from odd behavior in a particle called the BS (pronounced “B-sub-S”), which flips back and forth between its matter and antimatter forms three trillions times per second. Researchers believe that such a breakdown, known as CP violation, is required to explain why matter is so abundant.

Researchers say the finding is well worth following up to make sure it is not a random clump in the data, as frequently happens in particle physics experiments.
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Neither result on its own was very convincing, so a team of European researchers combined the data, similar to the way medical researchers cull information from independent clinical trials, to look for rare side effects. Together, the data make it 99.7 percent likely that the discrepancy is real, not due to chance, says physicist Luca Silvestrini… Such analyses require making judgment calls, but Silvestrini says he is confident in the finding.

We posted on this study last month in: Explaining the Missing Antimatter

Orzel: What Everyone Should Know About Science

What Everyone Should Know About Science by Chad Orzel:

1) Science is a Process, Not a Collection of Facts The essence of science, broadly defined, is that it is a systematic approach to figuring out how the world works:

1. look at the world around you
2. come up with an idea for why it might work that way.
3. test your idea against reality.
4. tell everybody you know the results of the test.

Put those steps together, over and over, and you have the best method ever devised for increasing our store of reliable knowledge. The precise facts found by this method are not as important as the process for finding them– given the process, and enough time, you can reconstruct whatever facts you need. The facts without the process are worse than useless, they’re dangerous.

Explaining the Missing Antimatter

Flipping particle could explain missing antimatter

It is one the biggest mysteries in physics – where did all the antimatter go? Now a team of physicists claims to have found the first ever hint of an answer in experimental data. The findings could signal a major crack in the standard model, the theoretical edifice that describes nature’s fundamental particles and forces.

In its early days, the cosmos was a cauldron of radiation and equal amounts of matter and antimatter. As it cooled, all the antimatter annihilated in collisions with matter – but for some reason the proportions ended up lopsided, leaving some of the matter intact.

Physicists think the explanation for this lies with the weak nuclear force, which differs from the other fundamental forces in that it does not act equally on matter and antimatter. This asymmetry, called CP violation, could have allowed the matter to survive to form the elements, stars and galaxies we see today.
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“It is tantalisingly interesting at the moment,” says Val Gibson, an expert on B meson physics at the University of Cambridge. “If it is true, it is earth-shattering.” Jacobo Konigsberg, who leads the CDF collaboration, says that Tevatron researchers are “cautiously excited” about the analysis. He points out that more data needs to be analysed to rule out a statistical fluke, which has happened several times before in particle physics.

Chinook Salmon Vanish Without a Trace

The Chinook salmon that swim upstream to spawn in the fall, the most robust run in the Sacramento River, have disappeared. The almost complete collapse of the richest and most dependable source of Chinook salmon south of Alaska left gloomy fisheries experts struggling for reliable explanations – and coming up dry.

Whatever the cause, there was widespread agreement among those attending a five-day meeting of the Pacific Fisheries Management Council here last week that the regional $150 million fishery, which usually opens for the four-month season on May 1, is almost certain to remain closed this year from northern Oregon to the Mexican border.
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So what happened? As Dave Bitts, a fisherman based in Eureka in Northern California, sees it, the variables are simple. “To survive, there are two things a salmon needs,” he said. “To eat. And not to be eaten.”

Fragmentary evidence about salmon mortality in the Sacramento River in recent years, as well as more robust but still inconclusive data about ocean conditions in 2005, indicates that the fall Chinook smolts, or baby fish, of 2005 may have lost out on both counts. But biologists, fishermen and fishery managers all emphasize that no one yet knows anything for sure.

Peru Meteorite Provides Puzzles

Peru meteorite may rewrite rules

Usually, only meteorites made of metal survive the passage through Earth’s atmosphere sufficiently intact to scoop out a crater. But the object which came down in the Puno region of Peru was a relatively fragile stony meteorite. During the fiery descent through Earth’s atmosphere, these are thought to fragment into smaller pieces which then scatter over a wide area.

Yet pieces of the estimated 1m-wide meteorite are thought to have stayed together during entry, hitting the ground as one.
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Peter Schultz told the conference that the meteorite was travelling at about 24,000km/h (15,000mph) at the moment of impact – much faster than would be expected. “This just isn’t what we expected,” said Professor Schultz, from Brown University in Providence, US. “It was to the point that many thought this was fake. It was completely inconsistent with our understanding of how stony meteorites act.”
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At the velocity it was travelling, fragments could not escape the “shock-wave” barrier which accompanies the meteorite’s passage through the atmosphere. Instead, the fragments may have reconstituted themselves into another shape, which made them more aerodynamic. Consequently, they encountered less friction during their plunge to Earth, holding together until they reached the ground. “Although [the meteorite] is quickly broken up, it is behaving like a solid mass,” Professor Schultz told the conference.

Excellent article. First it is just interesting. Also it shows how scientists have to learn from what they observe and try to understand what explains the results they see.

Laws of Physics May Need a Revision

Something seems wrong with the laws of physics

Einstein’s general theory of relativity swept Newton away by showing that gravity operates by distorting space itself.

Even Einstein, however, may not have got it right. Modern instruments have shown a departure from his predictions, too. In 1990 mission controllers at the Jet Propulsion Laboratory (JPL) in Pasadena, California, which operates America’s unmanned interplanetary space probes, noticed something odd happen to a Jupiter-bound craft, called Galileo. As it was flung around the Earth in what is known as a slingshot manoeuvre (designed to speed it on its way to the outer solar system), Galileo picked up more velocity than expected. Not much. Four millimetres a second, to be precise. But well within the range that can reliably be detected.
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Altogether, John Anderson and his colleagues analysed six slingshots involving five different spacecraft. Their paper on the matter is about to be published in Physical Review Letters. Crucially for the idea that there really is a systematic flaw in the laws of physics as they are understood today, their data can be described by a simple formula. It is therefore possible to predict what should happen on future occasions.

That is what Dr Anderson and his team have now done. They have worked out the exact amount of extra speed that should be observed when they analyse the data from a slingshot last November, which involved a craft called Rosetta. If their prediction is correct, it will confirm that the phenomenon is real and that their formula is capturing its essence. Although the cause would remain unknown, a likely explanation is that something in the laws of gravity needs radical revision.

An interesting puzzle that illustrates how scientists attempt to confirm our understanding and real world results. And those efforts include uncertainty and confusion. Too often, I think, people think science is only about absolute truth and facts without any room for questions. We understand gravity well, but that does not mean we have no mysteries yet to solve about gravity.

Research paper: The Anomalous Trajectories of the Pioneer Spacecraft

Scientists Search for Clues To Bee Mystery

Honey Bees Give Clues on Virus Spread by Carl Zimmer

Now, as farmers wait anxiously to see if the honeybees will suffer again this spring, the true cause of CCD remains murky. Skeptics have raised many reasons to doubt that Australian viruses are to blame. In Australia, bees that get Israeli acute paralytic virus don’t get sick, and the country has had no reports of CCD. And in places where honeybee colonies are collapsing — Greece, Poland, Spain — there are no imported Australian bees. These are not the sort of patterns you’d expect, the skeptics say, if Australian viruses were killing American bees.
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Whether scientists look inside a honeybee or look at the entire biosphere, nature is proving to be awesomely intricate. In the oceans and the soil, metagenomics is revealing millions of different kinds of microbes, with an almost inconceivable diversity of viruses shuttling between them, carrying genes from host to host. But we have almost no idea how these menageries work together, either in the biosphere or inside a host like a honeybee — or a human. Many of the microbes that metagenomics is revealing are entirely new to science. As genetic databases fill with DNA sequences from millions of new species, our scientific wisdom lags far behind.

How true. Watching as scientists try to work out what is going on with Colony Collapse Disorder is a great lesson in how scientists search for answers. As I stated earlier much of science is not about simple obvious truths but a search through confusing signs to try and determine what is going on. Answering why, is not always so easy as it appears when someone has already found the answer and posted it online.

Bats Are Dying in North-East USA

Vet College scientists aid investigation of why bats in Northeast are mysteriously dying By Krishna Ramanujan

Bat specialists from the New York State Department of Conservation (NYSDEC) have found 15 sites, up from four discovered last year, with sick bats: one in Massachusetts, two in Vermont and 12 in New York between Albany and Watertown. To help diagnose the problem, NYSDEC scientists are sending samples to Beth Buckles, assistant professor of biomedical sciences in Cornell’s College of Veterinary Medicine.

The affected bats are mostly little brown bats (Myotis lucifugus), among the most common North American bats. Other affected bats include the endangered Indiana bat (Myotis Sodalis), the northern long-eared bat (Myotis septentrionalis) and the eastern pipistrelle (Perimyotis subflavus). The bats live year round in the general area of study and usually hibernate each winter in the same caves.

Buckles and colleagues are conducting postmortem exams of organs and tissues and testing for signs of inflammation, bacteria, viruses and toxins. So far, the researchers do not yet know what is causing the massive casualties, Buckles said. “We have some good leads. We are continuing to look for infectious causes and are developing protocols to assess the bats’ metabolic states. They may not have enough fat to make it through the winter,” she said.

Many of the sick bats have a white fungus growing on their faces, are very thin and are congregating near to the cave entrances, a habit of ill bats. But it is “unprecedented” to find so many sick bats grouped near cave entrances, said Buckles. In two caves the researchers studied last year — that together had an estimated 18,000 bats — up to 97 percent died. The caves found this year may hold between 150,000 and 200,000 bats, many of them sick.

Related: Nectar-Feeding Bats – Bye Bye Bees