Sep 14, 2012
The chemical degradation occurred right at the interface between the paint and the varnish, the researchers added.
Van Gogh painted "Flowers in a blue vase" in 1887 in Paris; the Kröller-Müller Museum in the Netherlands acquired the painting in the early 20th century. Like many other paintings at the time, this one was covered with what was considered a protective varnish.
Then, in 2009, a conservation treatment "revealed an unusual gray opaque crust on parts of the painting with cadmium yellow paint," said paintings conservator at the museum Margje Leeuwestein in a statement.
The change in color was perplexing and didn't seem to be the result of simply the coating of varnish aging. "Varnish can become brown with age and thus can give all colors a more dark tone," study researcher Koen Janssens, of the University of Antwerp in Belgium, told LiveScience.
The research team found in an earlier study that photo-oxidation led to a darkening of Van Gogh's bright yellows in two paintings of his, "Bank of the Seine," and "View of Arles with Irises."
"However, when only the varnish has darkened and has not reacted chemically with the paint below it, it can relatively easily [be] removed and the original bright colors of the paint will become visible again," added Janssens, chairman of the university's department of chemistry.
Mysteriously, he said, the paint beneath the varnish had also become brittle and any attempts to remove the varnish failed — a bit of the gray crust came off with the varnish.
To sleuth out the culprit for the color change without sabotaging a masterpiece, experts at the museum took two microscopic paint samples from the original artwork. Janssens and colleagues used powerful, yet microscopic, X-ray beams to determine the chemical composition as well as the structure at that paint-varnish interface. Rather than the crystalline cadmium sulfate compounds they would expect due to oxidation of the paint, they found a lead-sulfate compound.
(When ultraviolet and blue light falls on the paint, so-called photo-oxidation leads to the liberation of cadmium ions and sulfate ions from the yellow cadmium paint.)
It seems, the researchers said, that the negatively charged sulfate ions hooked up with lead ions from the varnish to form anglesite, an opaque lead-sulfate compound. The lead likely came from a lead-based drying agent, or siccative, added to the varnish.
To keep Van Gogh's painting from deteriorating further, Janssens suggests two actions. Since the process starts with the photo-oxidation, he recommends keeping the masterpiece in lower light conditions. In addition, he suggests using a more "high-tech type of varnish" that is more stable than the one previously used.
Read more at Discovery News
The announcement, at a news conference in Florence, follows the discovery of another skeleton, the fourth since the bone hunt began last year -- beneath an altar in the church of the now-derelict Convent of St. Orsola.
"The skeleton doesn't belong to the Mona Lisa, but it’s hinting to her burial. Indeed, she might be just underneath," Silvano Vinceti, president of a private organization known as the National Committee for the Promotion of Historic and Cultural Heritage, told a news conference on Wednesday.
Vinceti’s ambitious project aims to possibly reconstruct Lisa's face in order to see if her features match that of the iconic painting hanging at the Louvre Museum in Paris.
Indeed, most scholars believe that the Mona Lisa, known as La Gioconda in Italian or La Joconde in French, is the portrait of Lisa Gherardini, a member of a minor noble family of rural origins who married the wealthy merchant Francesco del Giocondo.
Known for controversial claims, like that letters and numbers are hidden inside the Mona Lisa painting, Vinceti has based his search in the convent on documents found by historian Giuseppe Pallanti some years ago.
The historian, who is not involved in the project, traced back Lisa's life from her birth on June 15, 1479, to her death at the age of 63.
Pallanti found several important documents, such as Francesco del Giocondo's will. There, the merchant asked his younger daughter, Marietta, to take care of his "beloved wife," Lisa.
At that time, Marietta, one of Lisa and Francesco's five children, had become a nun, so she brought her mother to the nearby convent of Sant'Orsola.
Lisa remained there until her death on July 15, 1542, according to a document known as a "Book of the Dead," found by Pallanti in a church archive.
The record noted that the whole parish turned out for her funeral, showing that Lisa was rather famous in Florentine society.
According to Vinceti, ancient documents also appear to support the latest skeletal discovery.
"The ledgers kept by the nuns tell us that the skeleton belongs to Maria Del Riccio, a wealthy woman who died in 1609," Vinceti said.
He added that only Maria Del Riccio and Lisa Gherardini, who were not nuns, were given special burials in the convent.
Read more at Discovery News
The two newfound worlds are Jupiter-like behemoths far too hot to be habitable. But their existence may hearten those searching for life beyond Earth by helping to show that planets can form in a wide range of environments, such as dense clusters, researchers said.
"We are detecting more and more planets that can thrive in diverse and extreme environments like these nearby clusters," Mario Perez, NASA astrophysics program scientist in the Origins of Solar Systems Program, said in a statement. "Our galaxy contains more than 1,000 of these open clusters, which potentially can present the physical conditions for harboring many more of these giant planets."
The two newly discovered "hot Jupiters," which are called Pr0201b and Pr0211b, orbit different sun-like stars in the Beehive Cluster, a collection of about 1,000 stars that swirls around a common center. Each planet likely has a dazzling night sky, one much starrier than we're used to here on Earth.
Both alien worlds sit extremely close to their stars. Pr0201b completes an orbit every 4.4 days, while Pr0211b makes one lap around its star every 2.1 days.
Celestial beehive of planets
The Beehive Cluster, which sits about 550 light-years from Earth, is an open cluster -- a group of stars born from the same cloud of material at roughly the same time (in the Beehive's case, about 600 million years ago). So the 1,000 stars there share a similar chemical composition, researchers said.
Astronomers had previously discovered two alien planets around massive stars in clusters, but none had been found around sun-like stars within a cluster until now, researchers said.
"This has been a big puzzle for planet hunters," said study lead author Sam Quinn, an astronomy graduate student at Georgia State University. "We know that most stars form in clustered environments like the Orion nebula, so unless this dense environment inhibits planet formation, at least some sun-like stars in open clusters should have planets. Now, we finally know they are indeed there."
Quinn and his colleagues discovered the planets using a telescope at the Smithsonian Astrophysical Observatory's Fred Lawrence Whipple Observatory near Amado, Ariz. They detected the slight wobble the gravitational pull of the two huge worlds induced in their parent stars.
The discovery should catch the eye of astronomers interested in understanding how hot Jupiters end up so close to their host stars, researchers said. Most theories hold that these huge planets form much farther out, then move inward over time.
"The relatively young age of the Beehive cluster makes these planets among the youngest known," said Russel White, principal investigator on the NASA Origins of Solar Systems grant that funded the study. "And that's important because it sets a constraint on how quickly giant planets migrate inward -- and knowing how quickly they migrate is the first step to figuring out how they migrate."
Read more at Discovery News
Instead, the title of the world's hottest place should go to Death Valley, California, it said. "The all-time heat record held for exactly 90 years by El Azizia in Libya is invalid because of an error in recording the temperature," the UN body said in a statement.
The conclusion comes from a danger-fraught probe last year, conducted in the throes of the Libyan revolution, into how 58 Celsius (136.4 Fahrenheit) came to be documented on Sept. 13, 1922 at El Azizia, southwest of the Libyan capital Tripoli.
A panel of climate experts from around the world found that the thermometer used was not standard and determined that the person who measured the temperature was probably inexperienced.
"We're pretty sure that the person who was tasked with taking the measurements using this instrument didn't know how to use it," Randy Cerveny, the WMO rapporteur on climate extremes who headed the project, said in a video.
In the 1922 logsheet, "the observer had put the numbers in the wrong columns. That kind of tells us that he wasn't used to doing weather observation work," said Cerveny.
He theorized that the unidentified individual had in fact completely misread the thermometer "and was off by five degrees Celsius (8.2 Fahrenheit)."
The committee "decided that this measurement... simply wasn't valid," he said. "It was not the world's hottest temperature."
That honor, the WMO said, has thus been passed to what until now had been considered the next hottest temperature recorded on the planet: 56.7 degrees Celsius (134 degrees Fahrenheit) measured on July 10, 1913 in Death Valley, California.
The investigation "found some pretty startling things" in its detective work, Cerveny said.
And it was also a rollercoaster affair for those who took part in it.
Read more at Discovery News
Geologists at the U.S. Geological Survey (USGS) suggested in a recent study that warmer temperatures may be one cause of increased erosion of zinc and other heavy metals into the waterways of the Rockies. Part of that erosional process is called acid rock drainage, in which weathering of pyrite rocks forms sulfuric acid and frees heavy metals into the watershed.
"Acid rock drainage is a significant water quality problem facing much of the Western United States," lead researcher Andrew Todd of the USGS said in a press release. "It is now clear that we need to better understand the relationship between climate and ARD as we consider the management of these watersheds moving forward."
Warmer temperatures are dropping water tables in the Rockies, melting permafrost and increasing the rate of mineral weathering. These processes all contribute to increasing heavy metal concentrations. Levels of dissolved zinc found in Rocky Mountain streams have increased fourfold over the past 30 years.
High metal concentrations can destroy the life of a stream. Some waterways in the Rockies have been rendered lifeless by metal contamination from abandoned mining sites. As the Colorado Division of Reclamation Mining and Safety and other organizations work to clean up mountains, climate change may complicate matters as acid rock drainage increases the rate of heavy metal contamination.
Read more at Discovery News
Sep 13, 2012
The discovery could help to explain why both human and killer whale moms often live longer than males. In the case of killer whales (also referred to as orcas), the life span differences are profound, with females frequently surviving into their 90’s while males are rarely documented as living much past 50.
“For most animal species, the potential for an individual to increase the propagation of its genes stops when they stop reproducing,” co-author Darren Croft told Discovery News. “Our results show that, as with humans, female killer whales can continue to increase the propagation of their genes long after menopause.”
“They do this by helping to increase the survival of their older sons, which in turn increases the number of grandchildren fathered by their sons,” explained Croft, a senior lecturer in animal behavior at the University of Exeter. “Through this process, evolution favors females that live longer after their menopause."
Croft and his colleagues from the Universities of Exeter and York, the Center for Whale Research and the Pacific Biological Station analyzed records spanning 36 years documenting two populations of killer whales in the North Pacific Ocean off the coasts of the United States and Canada. The unique data set consisted of 589 individually identifiable animals, of which 297 died during the study period.
After statistically modeling births to calculate the probability of survival for any individual whale at any age, the researchers found that whales with long-lived mothers tended to survive longer. This particularly held true for sons.
“Due to the stable social structure of resident type killer whales, when sons mate, their offspring are cared for by the females in another family group,” Croft said. “In contrast, when daughters reproduce, the offspring stay in the group, which increases local competition for resources within the family group.”
“Theory predicts that in order to have the best chance of spreading their genes, without carrying additional burden, mothers should focus their efforts on their sons,” he added. “Our research supports this theory and demonstrates the extent to which older sons are dependent on their mothers for survival.”
Killer whale moms may do this by assisting with foraging, providing support during fights and through other means.
Human mothers obviously live in a different societal structure, so caring for sons, daughters, and their grandkids may hold equal importance, at least from an evolutionary standpoint.
Such caregiving might even help to explain why menopause exists in the first place.
“While it is believed that menopause evolved in humans partly to allow women to focus on providing support for their grandchildren, it seems that female killer whales act as lifelong carers for their own offspring, particularly for their adult sons,” Croft said. “It is just incredible that these sons stick by their mothers’ sides their entire lives.”
Michael Cant, an associate professor in evolution and animal behavior at the University of Exeter, Cornwall, told Discovery News, “This new data offers an exciting new insight into the evolutionary puzzle of menopause.”
Read more at Discovery News
The dog, seen in the above video, is a Great Dane named Zeus. When Zeus stands on his hind legs, he towers 7 feet 4 inches above his owner, Denise Doorlag of Otsego, Michigan.
The three-year-old measures 44 inches from foot to withers, making Zeus the same size as an average donkey.
The humongous hound weighs a whopping 115 pounds and eats around 12 cups of food a day, which is equivalent to an entire 30-pound bag of food. Despite his voracious appetite and the corresponding cost, Doorlag is very happy about her pet and his new honor.
"Zeus is an awesome dog," she was quoted as saying in a Guinness press release."The only downside is that everything costs more; the food, medicines, transport. We had to get a van to be able to transport him, oh, and if he steps on your foot - he leaves bruises!"
When she goes out with Zeus, "The most common thing people ask is: 'Is that a dog or a horse?' and 'Where's his saddle?'"
Zeus broke the record of the previous record-breaking tallest dog, Giant George, who is 1 inch shorter. Zeus is therefore the tallest dog ever recorded in history, according to Guinness.
I hope Giant George and Zeus get along, as that would be quite a sight to have the two of them walking together down the street.
In terms of the tallest cat, that honor went to a feline named Savannah Islands Trouble. (You can see and learn all about him here.) Unfortunately, the cat isn't around to celebrate the victory. He died on August 15 at the age of four years and five months, according to owner Debby Maraspini's tribute page. He "escaped his home on August 15 and was tragically killed," she wrote.
He was 19 inches tall, earning him the Guinness record.
Read more at Discovery News
"When I first saw it, I immediately knew it was something new and different -- I just didn't know how significant it was," said John Hart, a veteran Congo researcher who is scientific director for the Lukuru Wildlife Research Foundation, based in Kinshasa.
In fact, the find was something of a happy accident. Hart first spied the suspect monkey in 2007 while sifting through photographs brought back from a recently concluded field expedition to a remote region of central DRC.
Yet the image that caught his eye hadn't been taken in the field. It was snapped in a village, and showed a young girl named Georgette with a tiny monkey that had taken a shine to the 13-year-old.
What is that?
It was a gorgeous animal, Hart said, with a blond mane and upper chest, and a bright red patch on the lower back. "I'd never seen that on any animal in the area, so right away I said, 'Hmmm,'" he told OurAmazingPlanet.
Hart decided to get to the bottom of the mystery. Fast forward through five years of field work, genetic research and anatomical study, and today (Sept. 12) Hart and a list of collaborators formally introduced to the world a new primate species, dubbed Cercopithecus lomamiensis, and known locally as the lesula. Their work is announced in the online journal PLOS One.
It turned out that the little monkey that hung around Georgette's house had been brought to the area by the girl's uncle, who had found it on a hunting trip. It wasn't quite a pet, but it became known as Georgette's lesula. The young female primate passed its days running in the yard with the dogs, foraging around the village for food, and growing up into a monkey that belonged to a species nobody recognized.
Further investigation revealed the full story of the strange monkey. It turned out that C. lomamiensis, a cryptic, skittish primate, roams a swath of dense rainforest some 6,500 square miles (17,000 square kilometers).
"For a big mammal to go unnoticed is pretty unusual," said Kate Detwiler, a primatologist and assistant professor at Florida Atlantic University, and an author on the paper. Yet one visit to the area that the lesula calls home reveals why the monkeys escaped scientific notice for so long, Detwiler told OurAmazingPlanet. This region of the DRC is remote and vast.
The trees tower overhead, blocking out the sun, and the forest floor -- the chief domain of the lesula -- is steeped in a permanent gloom. The forest is full of sounds. At first light, the lesulas raise a lilting chorus of booming calls, distinct from the cries of their monkey neighbors who pass their lives in the trees high above the forest floor; at dusk, the cries of African grey parrots echo through the canopy. The earth is wet and soft, and feet sink into the ground with each step. There is a gentle, steady thud as fruit falls from the trees.
One gets the feeling of being on a ship very far out to sea, Detwiler said ?only here, the ocean is the endless expanse of the trees. "I felt so privileged to be there," she said. "I wish everybody could have that experience."
The lesulas live in this isolated region in groups up to five strong, and feeds on fruit and leafy plants. The males weigh up to 15 pounds (7 kilograms), about twice the size of the females. They also have some rather arresting anatomical features.
"They have giant blue backsides," Hart said. "Bright aquamarine buttocks and testicles. What a signal! That aquamarine blue is really a bright color in forest understory."
"So in terms of monkey viewing, females can definitely find males," Detwiler said.
"We don't really know what this means because it's very uncommon for monkeys in this lineage," she added.
The only other monkey to share this feature is the lesula's closest cousin -- the owl-faced monkey, a species that lives farther east. At first it was thought the monkeys were close kin, but genetic analysis suggests the two species split from a common ancestor about 2 million years ago.
Now that the new species has been formally identified, Hart said, the next task is to save it. Although the lesula is new to science, it is a well-established sight on the dinner table.
What's for dinner
There's a thriving market for bush meat, particularly in urban areas, Hart said, and the monkeys are just one of dozens of species, from snakes to elephants to apes, that are targeted.
"People have disposable income, and this is the cheapest meat," he said. "Bush meat is a go-to item because it's less expensive than chicken or beef. This is not a new problem, but it's a problem that doesn't have a solution yet."
Read more at Discovery News
Kepler's supernova remnant is located within the constellation Ophiuchus, but astronomers haven't been able to accurately pin down its distance or how it was formed. Now, with new observations by NASA's Chandra X-ray Observatory, the structure and scale of the remnant are clearer than ever before... and it turns out the stellar explosion was a much larger -- and distant -- event than anyone thought.
Kepler's supernova remnant is what's left of a Type Ia supernova, the end result of a white dwarf star that's been "feeding" on material drawn off a companion star until a critical mass (aka the Chandrasekhar limit) is reached and rapid nuclear reactions are triggered, blowing the pair apart in a powerful, brilliant explosion equal to the light of 5 billion suns.
In fact the brightness of Type Ia supernovae is so consistent and well-known, astronomers use them to gauge intergalactic distances.
The distance to Kepler's remnant, however, has proven to be more elusive. Data gathered with Chandra over the span of more than 200 hours in 2006 has led to the image above, which shows varying X-ray energy levels emitted by the still-expanding gas of the supernova as well as the optical light shed by stars. We can see asymmetrical arcs of X-ray-bright gas in the upper regions of the remnant, which some astronomers are suggesting is the result of the supernova's ejected material plowing through the surrounding, slower-moving interstellar material.
In addition the spectra of these bright arcs reveals the presence of a large amount of iron, which indicates the explosion must have been very powerful. The original white dwarf may have even been emitting nova eruptions prior to the ultimate supernova.
Read more at Discovery News
Sep 12, 2012
Bem’s experiments suggested that college students could accurately predict random events, like whether a computer will flash a photograph on the left or right side of its screen. However scientists and skeptics soon questioned Bem’s study and methodology. Bem stood by his findings and invited other researchers to repeat his studies.
Replication is of course the hallmark of valid scientific research—if the findings are true and accurate, they should be able to be repeated by others. Otherwise the results may simply be due to normal and expected statistical variations and errors. If other experimenters cannot get the same result using the same techniques, it’s usually a sign that the original study was flawed in one or more ways.
Last year a group of British researchers tried and failed to replicate Bem’s experiments. A team of researchers including Professor Chris French, Stuart Ritchie and Professor Richard Wiseman collaborated to accurately replicate Bem’s final experiment, and found no evidence for precognition. Their results were published in the online journal PLoS ONE.
Now a second group of scientists has also replicated Bem’s experiments, and once again found no evidence for ESP. In an article forthcoming in The Journal of Personality and Social Psychology, researchers Jeff Galak, Robyn LeBoeuf, Leif D. Nelson, and Joseph P. Simmons, the authors explained their procedure: “Across seven experiments (N = 3,289) we replicate the procedure of Experiments 8 and 9 from Bem (2011), which had originally demonstrated retroactive facilitation of recall. We failed to replicate that finding. We further conduct a meta-analysis of all replication attempts of these experiments and find that the average effect size (d = .04) is no different from zero.” In other words there was no evidence at all for ESP. The paper, “Correcting the Past: Failures to Replicate Psi,” is available on the web page of the Social Science Research Network.
Anomalous Results And Replication
So far it’s not looking good for scientific evidence of psychic powers. There are many examples of anomalous studies and experiments that—if true—promise to revolutionize the world but turn out to be wrong. In March 1989 two chemists at the University of Utah, Stanley Pons and Martin Fleischmann, announced that they had discovered a technique for creating cold fusion, a potentially limitless source of free energy. Pons and Fleischmann insisted that their research was valid, though in the past quarter-century no one has reproduced their findings; Fleischmann died last month never having been vindicated.
Last year worldwide headlines crowed that a new experiment may have found particles moving faster than light, disproving a fundamental physics premise posited by Albert Einstein. Follow-up studies and experiments failed to replicate the original results.
As the authors of the new study conclude, “[Philosopher of science Karl] Popper defined a scientifically true effect as that ‘which can be regularly reproduced by anyone who carries out the appropriate experiment in the way prescribed’... Though decades have passed, that is still the operational definition of scientific truth. An effect is not an effect unless it is replicable, and a science is not a science unless it conducts (and values) attempted replications. No matter the outcome, it is indisputably admirable for Bem to encourage and facilitate the independent replication of his experiments. It is, by definition, what any scientist should do.”
Of course, the two studies so far do not completely invalidate Bem’s findings; there is no fixed number of failed replications that proves that an original experiment was fatally flawed. However with each study it becomes more and more likely that the claimed scientific evidence for psychic powers was never real.
There is no shame in proposing a wrong hypothesis or offering evidence of an effect that turns out not to be true; in fact it is exactly that self-correcting mechanism that makes science so robust and fruitful. No experiment is perfect, and there is always a margin of error. The problem is not in making mistakes, but in refusing to acknowledge those mistakes.
Read more at Discovery News
The researchers note they are not saying they have found King Richard III's remains, but that they are moving into the next phase of their search, from the field to the laboratory.
"(W)e are clearly very excited, but the University now must subject the findings to rigorous analysis. DNA analysis will take up to 12 weeks," Richard Taylor, the director of corporate affairs at the University of Leicester, told reporters this morning, as recorded in a tweet.
The remains were hidden within the choir of a medieval church known as Greyfriars, where the English monarch was thought to be buried. Though the location of this church had been lost, historical records suggested Richard III was buried there upon his death in battle in 1485.
Two skeletons were discovered: a female skeleton that was broken apart at the joints was discovered in what is believed to be the Presbytery of the lost Church; the other skeleton, which appears to be an adult male, was found in the church choir and shows signs of trauma to the skull and back before death, which would be consistent with a battle injury, the researchers said.
"A bladed implement appears to have cleaved part of the rear of the skull," according to a University of Leicester statement.
In addition, a barbed metal arrowhead was lodged between the vertebrae of the male skeleton's upper back, Taylor said, adding that the spinal abnormalities suggest the individual had severe scoliosis, though was not a hunchback, as he was portrayed by Shakespeare in the play of the king's name.
Even so, the scoliosis seen in the skeleton would've made the man's right shoulder appear visibly higher than the left one. "This is consistent with contemporary accounts of Richard’s appearance," according to the university statement.
University of Leicester archaeologists began excavating the parking lot of the Leicester City Council building on Aug. 25, in search of the church and the king's remains. Since then, they have turned up the Franciscan friary, a 17th-century garden thought to hold a memorial to the king and various other artifacts.
On Aug. 31, the dig team applied to the Ministry of Justice for permission to begin exhuming the two skeletons, a process that began on Sept. 4.
"We are hopeful that we will recover DNA from the skeleton," University of Leicester geneticist Turi King said at the briefing, as recorded in a tweet by the university.
The king's tales
King Richard III ruled for England two years, from 1483 to 1485, before dying in the Battle of Bosworth Field, part of the War of the Roses, an English civil war between the House of Lancaster and the House of York.
A century later, William Shakespeare penned "Richard III," a play about the tragic king — the last English king to die in battle.
The king seemed to have his own following. "Richard III is a charismatic figure who attracts tremendous interest, partly because he has been so much maligned in past centuries, and partly because he occupies a pivotal place in English history," Philippa Langley, a representative of the Richard III society, said in a statement.
"The continuing interest in Richard means that many fables have grown up around his grave," Langley added. For instance, one far-fetched tale described his bones being thrown into the Soar River.
Read more at Discovery News
The study, published in the latest Royal Society Biology Letters, represents the first time that virgin births have been detected in the wild. It also suggests that absence of males does not always instigate the phenomenon, which occurs among chickens, turkeys, lizards, sharks, insects and many other animals.
For this latest study, the researchers focused on two closely related species of North American pit viper snakes: the copperhead and the cottonmouth.
“In these populations, males are relatively common, hence females were not restricted from access to males, and therefore isolation from males is not a driving factor for parthenogenic reproduction (virgin births) here,” lead author Warren Booth, an assistant professor of molecular ecology at the University of Tulsa’s Department of Biological Sciences, told Discovery News.
Booth studied field-collected pregnant snakes and worked on the research with colleagues Charles Smith, Pamela Eskridge, Shannon Hoss, Joseph Mendelson III, and Gordon Schuett.
Out of a total of 59 litters from the snakes, the scientists selected two for DNA analysis. These two already showed signs of virgin birthing, since the eggs had multiple yolks and the litters included just a single male offspring.
The genetic analysis supported the suspected lack of paternal DNA contribution. Booth explained that, in each case, the female’s egg cell “fused to a part of itself, and her chromosomes doubled.” The offspring wound up having two copies of her set of chromosomes, and therefore half the genetic materials.
“This means she has very reduced diversity across her genome,” he said. “This is essentially an extreme form of inbreeding.”
Loss of genetic diversity can be a problem, leading to deleterious genes in the population. On the other hand, the process for certain species can sometimes purge out bad genes.
For example, Booth said, “We see extreme inbreeding in many insect species, such as bed bugs and cockroaches, and they thrive. So while inbreeding is never ideal, it is not necessarily bad in all cases.”
So far, the offspring of the studied snakes “are outwardly healthy,” he shared, “and on their way to sexual maturity.”
Demian Chapman, an assistant professor at Stony Brook University’s School of Marine and Atmospheric Sciences, is a leading shark expert. He has documented virgin births in sharks, such as in a female blacktip that was once housed at the Virginia Aquarium.
At the time, Chapman told Discovery News that such a male-less birth “may just be an occasional mistake that sometimes occurs when eggs are left unfertilized.”
But the latest findings suggest that this form of birth may be far more common among some animals than previously realized. Booth said that, based on his own past research on boa constrictors and cottonmouths, virgin births produce about 2.5 to 5 percent of litters. While those numbers aren’t huge, they indicate that dad-less snakes aren’t just an every-so-often novelty.
Read more at Discovery News
At least, that's the working hypothesis, and it seems to fit the data, although there are scientists who question its existence and tout alternatives to explain that accelerating expansion.
A new, two-year study by scientists at the University of Portsmouth and Ludwig-Maximilians-Universitat Munchen concludes that dark energy does, indeed, exist. Those results just appeared in the journal Monthly Notices of the Royal Astronomical Society.
In the early 20th century, scientists believed the universe was in a steady state. But when Albert Einstein was working on his theory of general relativity, the math just didn't add up: the universe should have been expanding. So he invented something called the cosmological constant -- a mathematical trick to balance everything out so that the equations described a static universe, rather than an expanding one.
But then astronomer Edwin Hubble discovered the universe actually was expanding -- Einstein's original equations were correct. He dubbed the cosmological constant (lambda) his "greatest blunder."
The universe wasn't done surprising us, however. In 1998, astronomers studying distant exploding stars called a Type 1A supernovae discovered that not only was the universe expanding, but that the rate of expansion was accelerating due to some type of unknown force or dark energy. And one of the explanations for this effect is -- you guessed it -- Einstein's cosmological constant.
While that discovery snagged its team leaders the 2011 Nobel Prize in Physics, it's not the only evidence in favor of dark energy. For instance, last May, a team of scientists from Melbourne's Swinburne University announced their independent confirmation of both the existence of dark energy and its rate of expansion, based on four years of data collected by a powerful spectrograph at the Australian Astronomical Observatory.
That study included more than 240,000 galaxies going back over seven billion years and showed that the growth of galaxy clusters and super clusters has slowed down. This means that in the most distant parts of universe -- those further back in spacetime -- gravity dominates. It's only in our current part of the cosmos where dark energy dominates, and hence we are seeing accelerated expansion.
The Swinburne researchers also looked at the distances between pairs of galaxies, and the ripples in the cosmic microwave background radiation (CMB). They found that the average distance between galaxy pairs (about 500,000,000 light years) has been growing because of the expansion of space-time, providing further confirmation of dark energy.
One of the strongest pieces of evidence can be found in a unique feature of the CMB, known as the Integrated Sachs-Wolfe Effect, based on a 1967 prediction that light from the CMB would show a redshift -- i.e., it would become slightly "bluer" -- as it passed through gravitational fields of clumped matter.
Scientists didn't detect the Sachs-Wolfe Effect until 2003 -- Science magazine deemed it the "discovery of the year." It showed up as tiny gains in energy among photons in the CMB, based on comparing the temperature of the CMB with maps of galaxies in our local part of the universe.
As exciting as that discovery was, it was pretty weak signal, and might have been caused by something else -- space dust, for instance. So Tommaso Giannantonio and Robert Crittenden took the lead on a two-year study to re-examine that data and improve the galactic maps used in the original work.
Read more at Discovery News
Sep 11, 2012
The skeleton that is the focus of the study is nearly complete, revealing how this early mammal looked in the flesh and lived.
"Ernanodon was a badger-sized, rather chunky mammal with a short square skull, extremely reduced dentition and big claws on the forelimbs," lead author Peter Kondrashov told Discovery News.
"The structure of the forelimb indicates that this animal was doing a lot of digging, probably mostly in the search of food," added Kondrashov, who is an associate professor and chair of the Anatomy Department at the Kirksville College of Osteopathic Medicine.
He and colleague Alexandre Agadjanian analyzed the skeleton, which dates to the Late Paleocene (60 to 55 million years ago). This Ernanodon individual lived in Mongolia. Other, less complete, remains were previously found in China.
"Ernanodon is a unique find and represents one of the most complete skeletons ever collected from the Paleocene of the Naran Bulak locality," said Agadjanian, who works at the Borissiak Paleontological Institute of the Russian Academy of Sciences.
The animal's hind limbs were almost flat-footed, so the researchers don't think Ernanodon was much of a runner. It instead appears to have spent most of its days digging and eating, without much chomping.
"Based on the structure of the teeth -- very thin enamel layer, reduced tooth size -- it appears that the food was rather soft and did not require a lot of chewing," Kondrashov explained. "Similar dental structure is observed in mammals that feed on termites, ants and other social insects, so we think that it was specialized in feeding on social insects as well."
While Ernanodon is long gone and has no direct descendants, the scientists believe this animal was related to a group of extinct mammals known as palaeanodonts. They too had bulky bodies, tiny teeth, and big claws for digging.
These animals are, in turn, related to modern mammals called pangolins, or scaly anteaters, which live in Africa and Asia.
Based on the earlier evidence for Ernanodon, scientists thought the then enigmatic mammal was related to modern armadillos or sloths. While pangolins somewhat resemble these animals in appearance and behavior, they represent a different genus and species.
Read more at Discovery News
These animals reside on the ocean floor where they build their homes out of collagen on the shells of dead clams. It may not be an extravagant existence, but they've lived this way for 500 million years, according to a new study in the journal Lethaia.
What's even more interesting is that they've outlasted a more elaborate species that descended from a common ancestor.
"We think that change is always going to lead us to a better place, that evolution is always going to lead to something better," said lead author Charles Mitchell, a University of Buffalo geology professor. "But all this progress in making all these wonderful pelagic graptolites didn't lead them to take over the world. They didn’t survive, but these simple dudes, these bottom-dwelling creatures, did."
"Pelagic graptolites" were ancient zooplankton that went extinct around 350 million years ago. They evolved rapidly, splitting into many new species and evolving many new traits. Some of this happened because they were living closer to the ocean's surface, which tends to be more unstable.
In the meantime, the rhabdopleurids hardly changed, doing their clam and collagen thing over the eons. (They secrete the collagen themselves, so that's not coming from the shellfish.)
Here's what a colony of them looks like:
"High speciation rates generally go hand in hand with high extinction rates, and likewise low with low," Mitchell said. "Conservative lineages may weather the storms of climate change and other events, but do not become big parts of the ecosystem, whereas the major players are impressive but often brought low by mass extinction and other ‘slings and arrows of outrageous fortune.'"
Read more at Discovery News
On Mars, rocks are front and center in the ongoing quest to uncover the planet's history and find evidence of past life. Unfortunately, we haven’t been able to send men to Mars yet; men with their built-in geology kits: eyes, hammer-wielding hands, and clever brains.
Instead, we send geology-capable surrogates in the form of rovers like Spirit and Opportunity. And in the case of these two rovers, their geologic instruments are also a tribute to the victims of the September 11 attacks on the World Trade Center.
Smashing a rock with a rover's arm is a little dicey and potentially very problematic. So the MER team behind Spirit and Opportunity (both of which landed on Mars in 2004) came up with an easier and safer way to see inside a rock: scrape away its weathered surface. Then individual instruments -- spectrometers to determine composition, magnets to collect magnetic dust particles, and a microscopic imager for high resolution photos -- could do the science. The tool for this first step, scraping into the rocks, was the rock abrasion tool or RAT.
The small tube-shaped RAT, about the size of a soda can, was designed to grind and brush away dirt from a rock’s surface. The result was a small circular depression revealing the rock’s interior. Because the tool’s small parts were prone to clogging with dust and rock shavings, each instrument also included a wire brush to keep the “teeth” clean and maintain its cutting power. This quick fix also had the benefit of avoiding cross contaminating between different rocks.
The RATs were designed and built by Honeybee Robotics, a New York City company created and led Steve Gorevan. Founded in 1983, Honeybee got its first NASA contract in 1986. Since then, the company has worked on over 100 NASA projects with nearly all the the agency’s centers -- fitting since Gorevan pursued engineering because of a childhood desire to work for NASA.
But Gorevean isn’t just clever about engineering, he’s also clever about his health and fitness. In 2001, though he lived just blocks away from Honeybee’s Manhattan offices, he biked to work along a circuitous route that took him through the plaza at the World Trade Center.
On the morning of Sept. 11, he heard jet engines on his ride. Not the sound of a regular approach to LaGuardia or JFK Airports, either, but the out-of place sound of engines accelerating and flying too low to the ground. Then he heard a crash. He stopped and got off his bike. Standing in the street with a dozen or so others, he stared at the flames spewing out of the North tower. After a minute, he hopped back on his bike and pedaled the mile north to Honeybee.
Honeybee employees watched the morning’s events unfold from their building’s rooftop. They saw the towers fall and watched as masses migrated away from the site, ghostlike from a layer of soot. But work at Honeybee couldn’t stop; employees couldn't put their work on hold to help the city recover. They had to go to Mars.
Steve Kondos, the JPL engineer in charge of the Honeybee RAT contract, came up with the way for the New York company to honor the victims: include material from the wreckage of the World Trade Center on the rovers. A lasting tribute on Spirit and Opportunity from the whole MER team.
Rather than having a Honeybee employee walk over to a fire station and ask for a piece of metal, the idea went through formal channels all the way to mayor Rudy Giuliani who approved the idea. Less than three months later, a representative from the mayor’s office arrived at Honeybee’s building with a box. It contained debris from both towers: a steel bracket, two large bolts, and a twisted plate of aluminum. The acrid smell that had permeated the city after the attacks was also preserved in that small box.
Read more at Discovery News
Above, is a true-color image taken from the Landsat 7 satellite using the Enhanced Thematic Mapper Plus (ETM+) on Sept. 12, 2001, at roughly 11:30 a.m. Eastern Daylight Savings Time.
Image courtesy USGS Landsat 7 team, at the EROS Data Center. Credit: NASA Earth Observatory.
Below is the perspective seen from the International Space Station on the morning of Sept. 11, 2001.
From Discovery News
Sep 10, 2012
As previously reported on Wired.co.uk, pressure group Society for Textbook Revise had managed to persuade textbook publishers to drop sections from their books that discussed the evolution of horses and the Jurassic-era early avian-like dinosaur Archaeopteryx.
Now, however, a special panel convened by the South Korean government has recommended that the publishers ignore the creationists’ arguments — which should mean that textbooks reintroduce the old segments before the start of the next school year.
The argument of the Society for Textbook Revise — an offshoot of the Korea Association for Creation Research — rested on there being debate among evolutionary scientists over whether Archaeopteryx could fly, or glide, or merely had feathers for decoration. This disagreement was extrapolated to cast doubt on the whole evolutionary history of birds.
In response, South Korea’s Ministry of Education, Science and Technology set up a panel experts to assess the campaign’s claims. They disagreed that their Archaeopteryx objection was a valid argument, and said it should remain in the textbooks. The campaign group also claimed that a section on the evolution of the horse was too simplistic, which the panel agreed with — but they have merely recommended replacing it with a more thorough explanation, or a new section on the evolution of another animal like the whale.
Read more at Wired Science
The fear is that a random mutation could turn the virus into an infecting machine, leading to another swine flu pandemic, like the 2009 H1N1 outbreak that may have killed more than half a million people around the world in its first year of circulation.
A new study illustrates one way that the next flu pandemic might begin. Focusing on a variant of swine flu circulating in Korea, researchers discovered a gene mutation that makes the virus especially virulent.
It's not this particular virus that should cause concern at this point. Instead, the research represents an incremental step towards understanding what it is that turns a mild virus into a devastating one. By compiling a more complete library of such mutations, the hope is to better predict which animal viruses we should be most worried about and better prevent major outbreaks.
"This is not: Oh my gosh, we've got to run for the hills, this virus is coming," said Richard Webby, an influenza virologist at St. Jude Children's Research Hospital in Memphis, and one of the new study's authors. "We really want to be able to try to assign some sort of risk to viruses we find in animal populations, and to know which out of a huge diversity of viruses we in human health should be concerned about. It's very hard to do that at this stage."
Influenza viruses are constantly moving targets, said Daniel Perez, a virologist who works with influenza at the University of Maryland, College Park. Regularly and without warning, this group of viruses acquire new mutations that affect how they behave.
To better understand what makes some flu viruses more threatening than others, Webby and colleagues in both the United States and Korea looked at several viruses that are currently circulating only in Korean pigs but are closely related to strains found in North America. To see how those strains might affect people, the researchers used them to infect ferrets, which respond to flu viruses much like we do.
Most of the viruses caused only mild infections. But one virus, called Sw/1204, killed the animals within 10 days. And it spread from ferret to ferret through droplets that entered the air as the animals breathed.
Genetic analysis isolated two mutations that made the Sw/1204 virus more infectious than others. One mutation, called HA-225, had already been well studied, Webby said. It is known to affect the part of the virus that sticks to host cells, allowing infection to occur.
The other mutation, called NA-315, hadn't been implicated in influenza infections before. This mutation seems to influence the virus' ability to leave the host cell after it has replicated and go on to infect other cells.
It wouldn't be surprising if the same mutation appeared in other parts of the world, Perez said, because the Korean viruses used in the study are very similar to viruses circulating elsewhere.
Read more at Discovery News
This summer, three people died and eight were infected with hantavirus -- a disease carried by rodents -- after visiting Yosemite National Park; a Colorado girl reportedly contracted the plague from flea bites she received while camping; researchers reported the cases of two Missouri men infected with a never-before-seen virus carried by ticks; and nearly 2,000 people across the United States fell ill with West Nile virus, which is carried by mosquitoes.
Experts say the number of new diseases crossing from animals to people has indeed increased in recent years, from fewer than 20 in the 1940s to about 50 in the 1980s, according to a 2008 study published in the journal Nature. Between 1990 and 2000, more than half of newly identified infectious diseases originated in wildlife, the study says.
It's possible the increase is partly due to better detection of diseases, as well as new technologies that allow researchers to better study viruses, said Tony Goldberg, a professor at the University of Wisconsin-Madison's School of Veterinary Medicine.
But there is also evidence the rise represents a true increase in the number of diseases that spread to people from animals. "The general feeling is that something is changing," Goldberg said.
Global changes, including movement of people, deforestation and climate change, may all be contributing to the more rapid emergence of animal-borne diseases in people, Goldberg said.
For instance, the ticks that carry Lyme disease prefer the type of habitats that arise when forests are fragmented, as occurs with deforestation, Goldberg said. Deforestation is sometimes done for the development of new housing complexes close to the wilderness, bringing people into contact with these ticks, he said.
Global travel also allows diseases to spread quickly around the world. It's thought that West Nile virus, which arrived in New York City in 1999, came here from Europe or the Middle East, Goldberg said. The virus was first seen in Africa in the 1930s.
It's likely the next big infectious disease that will pose a threat to humans will come from animals, Goldberg said.
"That’s what almost everybody will put their money on," he said.
About three-quarters of all known human infectious diseases cross directly from animals to humans (like West Nile virus), or came from animals in the recent past (such as HIV), Goldberg said.
Avoiding risky interactions between animals and people, and educating people about ways to avoid exposure to animal-borne diseases, may help reduce the risk of new infectious diseases, Goldberg said.
Read more at Discovery News
In reality, our Milky Way really does pose numerous hazards to Earth during the sun's orbital journey around the galactic center. But no future space disaster can be circled on a calendar on Dec. 21 or any other date.
The sun has completed 20 orbits of the galactic hub since Earth formed. Each orbit is called a galactic year -- a vast stretch of time (220 million Earth years) that the Mayans could have never imagined. Whatever cosmic catastrophes might have happened along the way, it has not prevented complex life from arising and evolving on Earth over roughly the past three galactic years. There have been attempts at statistically linking mysterious mass extinctions to cosmic disasters, but we simply don't have enough data, says Colin Norman the Johns Hopkins University in Baltimore, Md.
The reality is that the potential of navigational hazards along our galactic journey lie far into the future over many millions or billions of years. Our distant descendants could come up with strategies to guard against some of these mishaps. However, the biggest threat is from extremely rare energetic events in the galaxy, says Norman.
This is sobering because we suspect there could be ancient Methuselah planets in the galaxy that might have formed 12 billion years ago (as opposed to Earth’s 4.5 billion year birthday). But they would have been sterilized of life by radiation from multiple supernova and hot stellar winds from giant stars.
Over time there have been 1 billion supernovae in our galaxy. They accelerate cosmic rays that irradiate any nearby star systems. Even more devastating are so-called Quimby events. These are an unusual class of extraordinarily powerful supernova that defy conventional explanations for their power generation. It's hypothesized that these super-blasts only happen in very rare stars that are over 100 times the mass of our sun. There could have been 10 million of these popping off in our galaxy to date.
Gamma ray bursts (GRBs) ratchet up the killer potential. It's estimated there have been 100,000 gamma-ray bursts over our galaxy's lifetime. These are produced by the biggest bangs since the Big Bang: hypernovae. These titanic stellar detonations unleash 1,000 times the energy of a supernova. It is concentrated in a narrow Death Star-like beam. The GRB beam evaporates anything that is nearby and along its path. The radiation would catastrophically damage DNA even over interstellar distances.
Planetary systems will survive the fireworks, but the clouds of cometary embryos surrounding these systems (known as the Oort cloud for our solar system) could be disrupted. The planets could then be subjected to devastating comet showers. However, advanced civilizations would have the technological prowess to set up a planetary protection system to deflect space invaders, like the classic Atari arcade game Asteroids.
The frequency of supernova blasts will go up as a firestorm of new star birth sweeps across the merging galaxies. But advanced civilizations might set up radiation storm cellars by burrowing underground, or even hollowing out asteroids.
When the supermassive black holes in the cores of the Milky Way and Andromeda merge, they will send out a gravitational wave that will momentarily distort the shape of every object in the galaxy. But not to worry. Earth's diameter would briefly "squish" by merely one-millionth of an inch.
There will not be any residual dust and gas in space to feed the 10 million solar mass newly merged black hole. All the Milky Way's nebulosity will have all been blown away by the star formation firestorm. Therefore the elliptical galaxy formed from the Milky Way-Andromeda merger will not have a blazing active galactic nucleus powered by a well-fed black hole.
Read more at Discovery News
Sep 9, 2012
J. Christopher Howk, Nicolas Lehner and Grant Mathews of the Center for Astrophysics at the University of Notre Dame published a paper this week in the journal Nature titled "Observation of interstellar lithium in the low-metallicity Small Magellanic Cloud."
"The paper involves measuring the amount of lithium in the interstellar gas of a nearby galaxy, but it may have implications for fundamental physics, in that it could imply the presence of dark matter particles in the early universe that decay or annihilate one another," Howk says. "This may be a probe of physics in the early universe that gives us a handle on new physics we don't have another way to get a handle on right now."
The team, using observations from European Southern Observatory's Very Large Telescope (VLT) in Chile, measured the amount of lithium in the interstellar gas of the Small Magellanic Cloud, which has far fewer star-produced heavy elements than the Milky Way. In addition to the production of elements by fusion in the core of stars, scientists believe conditions immediately after the Big Bang led to the formation of some elements, including a small amount of lithium.
Stars in the Milky Way have about four times less lithium on the surface than expected by Big Bang predictions. Some scientists suggest that stellar activity might destroy lithium, or the element might sink from the surface through lighter hydrogen, but the remarkably consistent ratio from star to star is a challenge to those explanations. Observations of gas in the Small Magellanic Cloud revealed the amount of lithium that predictions say would have been produced at the Big Bang, but leave no room for subsequent production of the element.
One explanation could be a novel kind of physics operating at the Big Bang that left less lithium than the Standard Model predicts. To pursue this possibility, the team will conduct three nights of observations on the VLT in November. They will look for the lithium isotope 7Li in the Large Magellanic Cloud and 6Li in both the Large Magellanic Cloud and the Small Magellanic Cloud. The standard model predicts that no 6Li was created at the Big Bang.
Read more at Science Daily
The IAA said the cistern could have held 66,000 gallons (250 cubic meters) of water; it likely dates back to the era of the First Temple, which, according to the Hebrew Bible, was constructed by King Solomon in the 10th century B.C. and then destroyed 400 years later.
Israeli archaeologists believe the reservoir served the general public in the ancient city, but say its location hints at a role in the religious life of Jerusalem.
"Presumably the large water reservoir, which is situated near the Temple Mount, was used for the everyday activities of the Temple Mount itself and also by the pilgrims who went up to the Temple and required water for bathing and drinking," Tvika Tsuk, chief archaeologist of Israel's Nature and Parks Authority, said in a statement.
Excavation director Eli Shukron, with the IAA, said the reservoir also sheds new light on the extent of the public water system in Jerusalem hundreds of years ago.
"It is now absolutely clear that the Jerusalem's water consumption during the First Temple period was not solely based on the output of the Gihon Spring, but that it also relied on public reservoirs," Shukron said in a statement. The Gihon Spring was the main source of water for the city.
The reservoir was exposed during excavations on a massive drainage channel dating to the Second Temple period, according to the IAA. When that channel was constructed, its builders had to remove or cut through existing rock-hewn structures along the route, such as this reservoir.
Read more at Discovery News