Category Archive 'Science'
20 Apr 2017

First Tsavo Man-Eater, Scientists Find, Had a Toothache

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Colonel Patterson with the first deceased Man-Eater.

Vanderbilt News:

An analysis of the microscopic wear on the teeth of the legendary “man-eating lions of Tsavo” reveals that it wasn’t desperation that drove them to terrorize a railroad camp in Kenya more than a century ago.

“Our results suggest that preying on people was not the lions’ last resort, rather, it was simply the easiest solution to a problem that they confronted,” said Larisa DeSantis, assistant professor of earth and environmental studies at Vanderbilt University.

The study, which she performed with Bruce Patterson, MacArthur Curator of Mammals at The Field Museum of Natural History in Chicago, is described in a paper titled “Dietary behavior of man-eating lions as revealed by dental microwear textures” published online April 19 by the journal Nature: Scientific Reports. …

In order to shed light on the lion’s motivations, DeSantis employed state-of-the-art dental microwear analysis on the teeth of three man-eating lions from the Field Museum’s collection: the two Tsavo lions and a lion from Mfuwe, Zambia that consumed at least six people in 1991. The analysis can provide valuable information about the nature of animal’s diet in the days and weeks before its death.

DeSantis and Patterson undertook the study to investigate the theory that prey shortages may have driven the lions to man eating. At the time, the Tsavo region was in the midst of a two-year drought and a rinderpest epidemic that had ravaged the local wildlife. If the lions were desperate for food and scavenging carcasses, the man-eating lions should have dental microwear similar to hyenas, which routinely chew and digest the bones of their prey.

“Despite contemporary reports of the sound of the lion’s crunching on the bones of their victims at the edge of the camp, the Tsavo lion’s teeth do not show wear patterns consistent with eating bones,” said DeSantis. “In fact, the wear patterns on their teeth are strikingly similar to those of zoo lions that are typically provisioned with soft foods like beef and horsemeat.”

The study provides new support for the proposition that dental disease and injury may play a determining role in turning individual lions into habitual man eaters. The Tsavo lion that did the most man eating, as established through chemical analysis of the lions’ bones and fur in a previous study, had severe dental disease. It had a root-tip abscess in one of its canines—a painful infection at the root of the tooth that would have made normal hunting impossible.

“Lions normally use their jaws to grab prey like zebras and buffalos and suffocate them,” Patterson explained. “This lion would have been challenged to subdue and kill large struggling prey. Humans are so much easier to catch.”

The diseased lion’s partner, on the other hand, had less pronounced injuries to its teeth and jaw—injuries that are fairly common in lions which are not man eaters. According to the same chemical analysis, it consumed a lot more zebras and buffalos, and far fewer people, than its hunting companion.

31 Mar 2017

“Fewer Than 1% of Papers Published in Today’s Scientific Journals Follow Scientific Method”

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Breitbart has some really bad news.

Fewer than 1 percent of papers published in scientific journals follow the scientific method, according to research by Wharton School professor and forecasting expert J. Scott Armstrong.

Professor Armstrong, who co-founded the peer-reviewed Journal of Forecasting in 1982 and the International Journal of Forecasting in 1985, made the claim in a presentation about what he considers to be “alarmism” from forecasters over man-made climate change.

“We also go through journals and rate how well they conform to the scientific method. I used to think that maybe 10 percent of papers in my field … were maybe useful. Now it looks like maybe, one tenth of one percent follow the scientific method” said Armstrong in his presentation, which can be watched in full below. “People just don’t do it.”

Armstrong defined eight criteria for compliance with the scientific method, including full disclosure of methods, data, and other reliable information, conclusions that are consistent with the evidence, valid and simple methods, and valid and reliable data.

According to Armstrong, very little of the forecasting in climate change debate adheres to these criteria. “For example, for disclosure, we were working on polar bear [population] forecasts, and we were asked to review the government’s polar bear forecast. We asked, ‘could you send us the data’ and they said ‘No’… So we had to do it without knowing what the data were.”

According to Armstrong, forecasts from the Intergovernmental Panel on Climate Change (IPCC) violate all eight criteria.

“Why is this all happening? Nobody asks them!” said Armstrong, who says that people who submit papers to journals are not required to follow the scientific method.

A must-read.

25 Mar 2017

Now When Can I Buy a Pair of Clip-Ons?

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TechXplore:

A team of researchers at the University of Wisconsin has developed a pair of glasses that allows the wearer to have tetrachromatic vision….

Humans have three types of cone cells in the back of the eye to differentiate color. Some react to blue, some to green and some to red. The cones do their work by responding to the difference in wavelength of the incoming light. Such vision is known as trichromatic. In this new effort, the researchers have found a way of fooling the brain into seeing as if there were a fourth type of cone, by wearing glasses with two types of filters. The result is tetrachromatic vision. …

The filters remove some parts of the blue light spectrum. But the filters each remove a different part. When the filters are fitted into a frame and worn like regular glasses, the wearer is able to see colors that are normally hidden—metamers. In a sense, it is rather the opposite of what occurs with people who are color blind. They might see blue and red as the same, even though there is more light information there. Adding spectrum identification to color blind eyes allows for seeing more of what is already there. With the new combined filter system, a person is able to look at what appears to be an object that is all the same color, such as purple, and see more colors in it—those normally hidden metamers.

Hat tip to Glenn Reynolds.

18 Feb 2017

The Liberals’ “Settled Science”

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Donald Devine, in the American Spectator, has a fine time debunking the community of fashion’s popular notion of “settled science.”

The idea that people will not accept the findings of science drives a certain class of self-described intellectuals crazy. Even those who can comprehend the Yale University Cultural Cognition Project research warning that scientific findings are screened by individuals through pre-existing cultural beliefs and are interpreted in ways to reinforce those beliefs still insist their own scientific beliefs are objective and settled.

That research finds progressives risk averse, biased toward control of their environment, while conservatives tolerate risk, partial toward greater freedom — the recognition of which does not overcome the progressive insistence that relativity explains all motion or that global warming is “settled science.” Conservative wise man Eric Voegelin traced the progressive predisposition to the positivist philosopher Auguste Comte, who invented the social sciences to replace religion with objective empirical research that would eventually allow humans to achieve perfection in this world rather than waiting for the next.

The fact that this hope has fallen a bit short over the following century has not diminished its appeal. For progressivism, it is just science, at least when it agrees with its own reductionist, materialistic predispositions by academic fields dominated by fellow progressives. While it might surprise that 43 percent of physicists believe that God or some higher spirit affected material development, it is even a majority belief among biological and chemistry scientists. On the other hand, few hold this belief in psychiatry and many other social sciences.

In fact, settled science is rather difficult to find, even the purely physical sciences. Columbia University physicist Brian Greene explained: “[G]eneral relativity and quantum mechanics cannot both be right” as currently formulated, even though they are “the two foundational pillars upon which modern physics rests.” The journal Physical Review Letters reported that a major study of the light sterile neutrino, widely expected by scientists to undermine Standard Model physics, found at a “99% certainty” level that neutrinos do not even exist.

An article in Current Biology questioned whether biologists’ long-held conception of the basic structure of the animal cell is in fact universal. Ninety-eight percent of human genome DNA had long been determined to be “junk” and only 2 percent meaningful — until the ENCODE project recently reported that in fact at least 80 percent of it was active. Scientists have known for years there are 83 distinct areas in the brain, but the journal Nature published a study last year more than doubling the number of brain regions to 180.

The one field where the science must be “settled,” of course, is global warming. Or is it “climate change,” when clearly no skeptic doubts climate changes? Why the alteration in terminology? Perhaps because, in 2007, the world’s leading experts at the Intergovernmental Panel on Climate Change reported its “central forecast” for long-term warming to be 3 degrees C. Yet, since then its reports have not listed a single central estimate but did reduce its minimal expected warming down from a 1.5-degrees rise to only a 1.0-degree temperature increase.

The U.S.’s NASA-Goddard Institute did announce that 2016 was the “hottest year on record,” but while NASA had formerly warned against accepting “misleading” specific temperatures without considering the ranges of scores within the measurement margin of error, it did not repeat that warning in 2016. As the Wall Street Journal’s Holman Jenkins showed, after taking into account error margins, 2015 and 2016, two El Niño years, were actually tied for being the warmest years recorded, and 1998, 2003, 2005, 2006, 2007, 2009, 2010, 2012, 2013, and 2014 were all tied for second place, close behind.

As climatologist Judith Curry testified to Congress, IPCC models have forecast surface temperatures to increase 0.2 degrees C each 21st century decade. But during the first fifteen years, actual temperatures only increased 0.05, four times lower than predicted. And the models cannot explain why more than 40 percent of the temperature increases since 1900 took place between 1910 and 1945, which produced a mere 10 percent of the carbon emissions.

Read the whole thing.

Hat tip to John C. Meyer.

27 Jan 2017

Harvard Guys Make Metallic Hydrogen

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The Independent reports:

For nearly 100 years, scientists have dreamed of turning the lightest of all the elements, hydrogen, into a metal.

Now, in a stunning act of modern-day alchemy, scientists at Harvard University have finally succeeded in creating a tiny amount of what is the rarest, and possibly most valuable, material on the planet, they reported in the journal Science.

For metallic hydrogen could theoretically revolutionise technology, enabling the creation of super-fast computers, high-speed levitating trains and ultra-efficient vehicles and dramatically improving almost anything involving electricity.

And it could also allow humanity to explore outer space as never before.

But the prospect of this bright future could be at risk if the scientists’ next step – to establish whether the metal is stable at normal pressures and temperatures – fails to go as hoped.

Professor Isaac Silvera, who made the breakthrough with Dr Ranga Dias, said: “This is the holy grail of high-pressure physics.

“It’s the first-ever sample of metallic hydrogen on Earth, so when you’re looking at it, you’re looking at something that’s never existed before.”

At the moment the tiny piece of metal can only be seen through two diamonds that were used to crush liquid hydrogen at a temperature far below freezing.

The amount of pressure needed was immense – more than is found at the centre of the Earth.

The sample has remained trapped in this astonishing grip, but sometime in the next few weeks, the researchers plan to carefully ease the pressure.

According to one theory, metallic hydrogen will be stable at room temperature – a prediction that Professor Silvera said was “very important”.

“That means if you take the pressure off, it will stay metallic, similar to the way diamonds form from graphite under intense heat and pressure, but remains a diamond when that pressure and heat is removed,” he said.

If this is true, then its properties a super-conductor could dramatically improve anything that uses electricity.

“As much as 15 per cent of energy is lost to dissipation during transmission, so if you could make wires from this material and use them in the electrical grid, it could change that story,” the scientist said.

And metallic hydrogen could also transform humanity’s efforts to explore our solar system by providing a form of rocket fuel nearly four times more powerful than the best available today.

“It takes a tremendous amount of energy to make metallic hydrogen,” Professor Silvera said.

“And if you convert it back to molecular hydrogen, all that energy is released, so it would make it the most powerful rocket propellant known to man, and could revolutionize rocketry.

“That would easily allow you to explore the outer planets.

“We would be able to put rockets into orbit with only one stage, versus two, and could send up larger payloads, so it could be very important.”

However some scientists have theorised that metallic hydrogen will be unstable on its surface and so would gradually decay.

Asked what he thought would happen, Professor Silvera said: “I don’t want to guess, I want to do the experiment.”

Complete story.

20 Dec 2016

Robert Bruce (1274-1329)’s Face Reconstructed

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Real Clear Life:

A group of historians from the University of Glasgow recently partnered with scientists at Liverpool John Moores University to reconstruct the face of the father of Scottish independence, King Robert I, a.k.a. Robert the Bruce, who reigned from 1306 to 1329. The source material? A human skull owned by London’s Hunterian Museum (part of the Royal College of Surgeons).

23 Sep 2016

Ötzi the Iceman Speaks

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otzi

Science Alert:

We already know what Ötzi the Iceman was wearing when he died more than 5,000 years ago in the Italian Alps, as well as how many tattoos he had.

But now scientists have taken things one step further: they’ve managed to recreate the “best possible approximation” of his voice.

By using CT scans to measure the structure of the famous mummy’s vocal cords, throat, and mouth, scientists from Bolzano’s General Hospital in Italy have been able to digitally reconstruct what Ötzi might have sounded like while pronouncing vowels in Italian.

26 Jul 2016

Leonardo’s Notebooks Yield New Discovery

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LeonardoFriction

University of Cambridge Research:

Scribbled notes and sketches on a page in a notebook by Leonardo da Vinci, previously dismissed as irrelevant by an art historian, have been identified as the place where he first recorded his understanding of the laws of friction.

The research by Professor Ian Hutchings, Professor of Manufacturing Engineering at the University of Cambridge and a Fellow of St John’s College, is the first detailed chronological study of Leonardo’s work on friction, and has also shown how he continued to apply his knowledge of the subject to wider work on machines over the next two decades.

It is widely known that Leonardo conducted the first systematic study of friction, which underpins the modern science of “tribology”, but exactly when and how he developed these ideas has been uncertain until now.

Professor Hutchings has discovered that Leonardo’s first statement of the laws of friction is in a tiny notebook measuring just 92 mm x 63 mm. The book, which dates from 1493 and is now held in the Victoria and Albert Museum in London, contains a statement scribbled quickly in Leonardo’s characteristic “mirror writing” from right to left.

Ironically the page had already attracted interest because it also carries a sketch of an old woman in black pencil with a line below reading “cosa bella mortal passa e non dura”, which can be translated as “mortal beauty passes and does not last”. Amid debate surrounding the significance of the quote and speculation that the sketch could represent an aged Helen of Troy, the Director of the V & A in the 1920s referred to the jottings below as “irrelevant notes and diagrams in red chalk”.

Professor Hutchings’s study has, however, revealed that the script and diagrams in red are of great interest to the history of tribology, marking a pivotal moment in Leonardo’s work on the subject.

The rough geometrical figures underneath Leonardo’s red notes show rows of blocks being pulled by a weight hanging over a pulley – in exactly the same kind of experiment students might do today to demonstrate the laws of friction.

Professor Hutchings said: “The sketches and text show Leonardo understood the fundamentals of friction in 1493. He knew that the force of friction acting between two sliding surfaces is proportional to the load pressing the surfaces together and that friction is independent of the apparent area of contact between the two surfaces. These are the ‘laws of friction’ that we nowadays usually credit to a French scientist, Guillaume Amontons, working two hundred years later.”

LeonardoFriction2

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Paper: Leonardo da Vinci’s Studies of Friction

Abstract:

Based on a detailed study of Leonardo da Vinci׳s notebooks, this review examines the development of his understanding of the laws of friction and their application. His work on friction originated in studies of the rotational resistance of axles and the mechanics of screw threads. He pursued the topic for more than 20 years, incorporating his empirical knowledge of friction into models for several mechanical systems. Diagrams which have been assumed to represent his experimental apparatus are misleading, but his work was undoubtedly based on experimental measurements and probably largely involved lubricated contacts. Although his work had no influence on the development of the subject over the succeeding centuries, Leonardo da Vinci holds a unique position as a pioneer in tribology.

06 Oct 2015

Scientists Identified Skeletons of English Archers on Henry VIII’s Mary Rose

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EnglishArchers

I missed the article at the time, but back in 2012, the Telegraph was reporting that forensic breakthroughs had even succeeded in identifying which of the skeletons of men drowned on Henry VIII’s sunken flagship were elite English archers.

Researchers have identified the elite archers who died alongside sailors on Henry VIII’s flagship, due to evidence of repetitive strain in their shoulders and spines.

The ship sank off Spithead in The Solent in 1545, while leading an attack on a French invasion fleet. It stayed on the seabed until it was raised in 1982 and put on public display.

Over the past two years, scientists from the University of Swansea have been working to identify almost 100 skeletons kept at the Mary Rose Museum, in Portsmouth. …

[N]ew DNA extraction technology has been developed to identify a skeleton’s origin and other personal features such as eye and hair colour.

Scientists have also tested how the bows were used by archers at that time, by using real-life archers.

They have uncovered evidence of repetitive stress injuries among the bowmen, the elite soldiers of their day, which they believe came from hours of longbow practice.

Nick Owen, a sport and exercise biochemist who is leading the work, said yesterday that the developments would help uncover more about the individuals who died with their ship.

The DNA breakthrough had enabled his team to embark on more detailed profiling.

“We know plenty about the Mary Rose but much less about the people on board,” said Mr Owen, from the university’s college of engineering.

“The archers were the elite but the longbows they used took a toll of their bodies and you can see signs of repetitive stress in the shoulders and lower spine.”

A Swedish expert is also working on facial reconstructions for the new Mary Rose Trust museum, which is due to open next year.

At the time, many archers were thought to have travelled from Wales and other areas in the south west of England and were considered the elite warriors of their day.

Previous studies have shown that they lived off a diet of salt beef and biscuits. Their diet also included flour, oatmeal, suet, cheese, dried pork, beer and salted cod.

“They were 6ft 2in or 6ft 3in, and strapping individuals,” Mr Owen said.

“A longbow was 6ft 6in and made from a particular part of a yew tree to generate incredibly efficient ‘spring’.

“It was mega hi-tech, and it gave England and Wales military superiority. These archers were the elite athletes of their day.”

He added to the BBC: “It took years for these Archers to train to get to a level where they could use these very heavy bows.”

Alexzandra Hildred, the curator of ordnance at the Mary Rose Trust, has said the injuries could be the result of “shooting heavy longbows regularly”.

“Many of the skeletons recovered show evidence of repetitive stress injuries of the shoulder and lower spine,” she said.

“Being able to quantify the stresses and their effect on the skeleton may enable us at last to isolate an elite group of professional archers from the ship.”

19 Aug 2015

Something Peculiar Happened 4000 to 8000 Years Ago

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ReproductionGraph
These two graphs show the number of men (left) and women (right) who reproduced throughout human history.

Pacific Standard:

Once upon a time, 4,000 to 8,000 years after humanity invented agriculture, something very strange happened to human reproduction. Across the globe, for every 17 women who were reproducing, passing on genes that are still around today—only one man did the same.

“It wasn’t like there was a mass death of males. They were there, so what were they doing?” asks Melissa Wilson Sayres, a computational biologist at Arizona State University, and a member of a group of scientists who uncovered this moment in prehistory by analyzing modern genes.

Another member of the research team, a biological anthropologist, hypothesizes that somehow, only a few men accumulated lots of wealth and power, leaving nothing for others. These men could then pass their wealth on to their sons, perpetuating this pattern of elitist reproductive success. Then, as more thousands of years passed, the numbers of men reproducing, compared to women, rose again. “Maybe more and more people started being successful,” Wilson Sayres says. In more recent history, as a global average, about four or five women reproduced for every one man.

31 Mar 2015

Old English Medical Recipe Kills Bacteria as Well as Modern Antibiotic

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AngloSaxonRecipe
Bald’s Leechbook, British Library (Royal 12 D xvii)).

Scientists recently experimented with a recipe from Bald’s Leechbook aka Medicinale Anglicum an Old English medical text probably compiled in the ninth-century and found that a compound recommended for a common eye infection worked just as well as the modern antibiotic used to treat Methicillin-resistant Staphylococcus aureus (MRSA).

New Scientist:

The project was born when a microbiologist at the University of Nottingham, UK, got talking to an Anglo Saxon scholar. They decided to test a recipe from an Old English medical compendium called Bald’s Leechbook, housed in the British Library. …

Sourcing authentic ingredients was a major challenge, says Freya Harrison, the microbiologist. They had to hope for the best with the leeks and garlic because modern crop varieties are likely to be quite different to ancient ones – even those branded as heritage. For the wine they used an organic vintage from a historic English vineyard.

As “brass vessels” would be hard to sterilise – and expensive – they used glass bottles with squares of brass sheet immersed in the mixture. Bullocks gall was easy, though, as cow’s bile salts are sold as a supplement for people who have had their gall bladders removed.

After nine days of stewing, the potion had killed all the soil bacteria introduced by the leek and garlic. “It was self-sterilising,” says Harrison. “That was the first inkling that this crazy idea just might have some use.”

A side effect was that it made the lab smell of garlic. “It was not unpleasant,” says Harrison. “It’s all edible stuff. Everyone thought we were making lunch.”

The potion was tested on scraps of skin taken from mice infected with methicillin-resistant Staphylococcus aureus. This is an antibiotic-resistant version of the bacteria that causes styes, more commonly known as the hospital superbug MRSA. The potion killed 90 per cent of the bacteria. Vancomycin, the antibiotic generally used for MRSA, killed about the same proportion when it was added to the skin scraps. …

It wouldn’t be the first modern drug to be derived from ancient manuscripts – the widely used antimalarial drug artemisinin was discovered by scouring historical Chinese medical texts.

30 Mar 2015

How the Universe Will End

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26 Mar 2015

25% of People Have a Fourth Cone (Color Receptor)

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39Colors

Professor Diane Derval told me something today that I had not known.

The color nuances we see depend on the number and distribution of cones (=color receptors) in our eye. You can check [the above] rainbow: how many color nuances do you count?

You see less than 20 color nuances: you are a dichromats, like dogs, which means you have 2 types of cones only. You are likely to wear black, beige, and blue. 25% of the population is dichromat.

You see between 20 and 32 color nuances: you are a trichromat, you have 3 types of cones (in the purple/blue, green and red area). You enjoy different colors as you can appreciate them. 50% of the population is trichromat.

You see between 33 and 39 colors: you are a tetrachromat, like bees, and have 4 types of cones (in the purple/blue, green, red plus yellow area). You are irritated by yellow, so this color will be nowhere to be found in your wardrobe. 25% of the population is tetrachromat.

You see more than 39 color nuances: come on, you are making up things! there are only 39 different colors in the test and probably only 35 are properly translated by your computer screen anyway :)

I originally counted colors on the basis of differentiated rectangles I could see, which gave me too many. When I went back and looked strictly at color gradations, I got 39. And I do hate yellow.

Hat tip to Chico Kidd,

11 Mar 2015

Why Do Violins Have F-Holes?

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F-Hole

BoingBoing reports that a team from MIT has figured it out.

Why did violins slowly develop f-shaped sound-holes? Because it makes them more acoustically powerful than their ancestors, which had holes shaped liked a circle — as a team of MIT scientists recently concluded.

Back in the the 10th century, the makers of European stringed-instruments were building “fitheles” — the ancestor of the modern violin — but they used round holes. By the 12th century, they’d started using half-moon shapes, and a century later they’d refined it to a sort of C-shaped hole. Then in the 15th century they pioneered little circles at the ends of the holes, which, by the 17th century, had become the modern f-shaped hole.

A team of MIT scientists recently wondered why the shape had evolved that way. After crunching the math and doing some experiments, figured it out: The f-shape turns out to have physics that push a lot more air than a circular hole, making the violin’s output dramatically more powerful. From the Economist:

    “The answer, arrived at after several pages of advanced mathematics, and confirmed by experiment, is that holes’ sound-amplification properties depend not on their areas but on the lengths of their peripheries. They showed how the shape of the hole varied over the centuries, and how that affected its power output. The final Cremonese design had twice the sonic power of the circular holes of the fithele.”

Read the whole thing.

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