Archive for the ‘Science’ Category
Correlation does not equal causation, and a single exam cannot show a trend over time. Basic stuff, right?
But judging by coverage of a study just out in the Journal of Neuroscience, these are apparently foreign concepts for many folks in the media.
In the study, researchers at Boston’s Massachusetts General Hospital and Northwestern University in Chicago performed MRI brain scans on 20 young adult “casual” marijuana users and 20 age- and sex-matched nonusers. They found that, in the users, gray matter densities in the nucleus accumbens were higher than in controls, and the right amygdala and left nucleus accumbens were shaped differently.
Interesting, but remember that these findings only reflected differences between the marijuana users and controls at a single point in time. The researchers did not, could not, demonstrate that the differences resulted from marijuana smoking or even that the “abnormalities” relative to controls reflected changes from some earlier state.
You wouldn’t know that from the media coverage.
RTFA for a small sampling of almost universal crap
…Note that the study did not identify any cognitive or behavioral abnormalities in the cannabis users versus controls — it was strictly an MRI study.
That, however, didn’t stop senior author Hans Breiter, MD, of Northwestern from opining in the SfN press release that the study “raises a strong challenge to the idea that casual marijuana use isn’t associated with bad consequences.”
Um, no, it doesn’t — not without before-and-after MRI scans showing brain structure changes in users that differ from nonusers and documentation of functional impairments associated with those changes.
Further studies may – or may not – indicate one or another cause-and-effect relationship. That kind of study must be constructed differently than this one. And hopefully the press release and editors who get the email won’t be in a hurry to construe the study as something it isn’t.
Director and producer of films like Terminator, Titanic and Avatar, James Cameron has made a 9-part documentary on the environmental challenge climate change presents. The Years of Living Dangerously debuts Sunday night, April 13th, on Showtime. If you don’t subscribe to Showtime the debut will be available on YouTube.
Click on the graphic above to check out your choices.
Electronic cigarettes can change gene expression in a similar way to tobacco, according to one of the first studies to investigate the biological effects of the devices.
Presented at the American Association for Cancer Research annual meeting on 6 April in San Diego, California, the research looked at human bronchial cells that contained some mutations found in smokers at risk of lung cancer. The cells were immortalized, grown in culture medium that had been exposed to e-cigarette vapour and their gene expression profiled.
The researchers found that the cells grown in medium exposed to the vapour of e-cigarettes showed a similar pattern of gene expression to those grown in a medium exposed to tobacco smoke…
The changes are not identical, says study researcher Avrum Spira, who works on genomics and lung cancer at Boston University in Massachusetts. But “there are some striking similarities”, he says. The team is now evaluating whether the alterations mean that cells behave more like cancer cells in culture.
I don’t doubt the companies making a buck from this latest tobacco “substitute” will fight to the death to protect their profits. Your death. Their profits.
MIT professor of geophysics Daniel Rothman stands next to part of the Xiakou formation in China
A team of researchers from MIT may have found new evidence to shed light on the cause of the most devastating mass extinction in the history of our planet. The event, estimated to have taken place around 252 million years ago, was responsible for the extinction of roughly 90 percent of all life on Earth.
The team’s research indicates that the catastrophic event was in fact triggered by the tiniest of organisms, a methane-releasing microbe called Methanosarcina. New evidence suggests that at the time of the extinction, the microbes appeared in massive numbers across the world’s oceans, spreading vast clouds of the carbon-heavy gas methane into the atmosphere. This had the effect of altering the planet’s climate in a way that made it inhospitable to most other forms of life inhabiting Earth at that time.
It was previously believed that the mass extinction, known as the end-Permian extinction, was due to either vast amounts of volcanic activity, a devastating asteroid strike or prolific all-consuming coal fires. Any of these events could have caused the mass deaths, however there are inconsistencies in the evidence that point away from the traditional theories and towards the new findings presented by the researchers from MIT…
Although the team does not believe that…heightened levels of volcanism were responsible for the extinction itself, they do believe that it could have been the catalyst. The sudden and devastating increase in carbon-containing gases present during the end-Permian extinction is put down to a massive bloom of Methanosarcina. However, for this bloom to take place, the microbes would require an abundant source of carbon and nickel, both of which were discovered in a new analysis of sediments in China, and could have been distributed widely through a volcanic eruption.
The case for Methanosarcina being responsible for the extinction is further strengthened by the team’s findings that, at the time of the end-Permian extinction, the microbes had undergone a genetic transfer from another microbe. This is what gave the Methanosarcina the ability to produce methane at such a prolific rate.
With the catalyst of volcanic activity, the Methanosarcina were able to spread across our planet’s oceans unchecked. This allowed the microbes to produce vast quantities of carbon-containing methane, by harvesting the now carbon- and nickel-rich water. The release of said methane would have had the effect of raising the carbon dioxide levels in the waters, causing ocean acidification, irrevocably altering the ecosystem.
Let us hope no natural occurrence allows us to experiment firsthand with the hypothesis.
Of course, if such a cataclysm initiated, we can count on the usual assembly of know-nothings to stand around – doing their best to interfere with any attempt to save the species of Earth – while the rest of us die trying.
An 8-year-old South Carolina girl’s dream of having the woolly mammoth become the official state fossil has been put on hold while lawmakers debate an amendment that gives God credit for creation of the prehistoric animal.
A bill that recently passed the state House to designate the Columbian Mammoth as the state fossil stalled in the Senate after Republican Senator Kevin Bryant added two verses from the book of Genesis.
That amendment was ruled out of order but senators this week will debate a new amendment that says the mammoth was “created on the sixth day along with the beasts of the field,” Bryant said on Monday…
Just in case you think the notion of stupid vs ignorant has been resolved in Confederate politics.
The original measure followed a letter to elected officials by Olivia McConnell, an-8-year-old from New Zion, South Carolina.
In it, she pointed out that there is no state fossil, said Democratic Representative Robert Ridgeway, who received the letter and sponsored the measure.
McConnell suggested the elephant-like mammoth because an early find of its remains took place in 1725 on a South Carolina plantation where slaves dug up a tooth, Ridgeway said…
Reaction from some South Carolina residents has been “nasty,” Bryant said.
“Please stop making our state look like backwards hillbillies who believe in fairy tales,” Alex Davis commented on Bryant’s website. “Keep your religious views out of the government.”
Ridgeway said he was surprised at the controversy.
“I was just trying to support a young child who is interested in science,” he said. “We should support children in any endeavor that they seem interested in. That’s one thing the state should be behind.”
The official Republican response will most likely be “the behinder we are, the more behinder we get!”
When someone has chronic venous insufficiency, it means that because of faulty valves in their leg veins, oxygen-poor blood isn’t able to be pumped back to their heart. The George Washington University’s Dr. Narine Sarvazyan has created a possible solution, however – a beating “mini heart” that’s wrapped around the vein, to help push the blood through.
The mini heart takes the form of a cuff of rhythmically-contracting heart tissue, made by coaxing the patient’s own adult stem cells into becoming cardiac cells. When one of those cuffs is placed around a vein, its contractions aid in the unidirectional flow of blood, plus it helps keep the vein from becoming distended. Additionally, because it’s grown from the patient’s own cells, there’s little chance of rejection.
So far, the cuffs have been grown in the lab, where they’ve also been tested. Soon, however, Sarvazyan hopes to conduct animal trials, in which the cuffs are actually grown on the vein, in the body.
“We are suggesting, for the first time, to use stem cells to create, rather than just repair damaged organs,” she said. “We can make a new heart outside of one’s own heart, and by placing it in the lower extremities, significantly improve venous blood flow…”
Day-dreaming about a storehouse of replacement parts. This is not only possible – but likely. Just not in my lifetime. Sigh.
UN scientists are set to deliver their darkest report yet on the impacts of climate change, pointing to a future stalked by floods, drought, conflict and economic damage if carbon emissions go untamed.
A draft of their report, seen by the news organisation AFP, is part of a massive overview by the Intergovernmental Panel on Climate Change, likely to shape policies and climate talks for years to come…
Policies and climate talks among folks who aren’t stuck into biblical prophecy and/or fear of science.
“We have a lot clearer picture of impacts and their consequences … including the implications for security,” said Chris Field of the US’s Carnegie Institution, who headed the probe.
The work comes six months after the first volume in the long-awaited Fifth Assessment Report declared scientists were more certain than ever that humans caused global warming…
…“The assessments that we can do at the moment probably still underestimate the actual impacts of future climate change,” said Jacob Schewe of the Potsdam Institute for Climate Impact Research in Germany, who was not involved in the IPCC drafting…
Among the perils in the draft: Rising greenhouse-gas emissions will “significantly” boost the risk of floods, with Europe and Asia particularly exposed. In the highest warming scenarios of untamed greenhouse gas emissions, three times as many people will be exposed to severe river flooding as with lower warming…
If no measures are taken, “hundreds of millions” of coastal dwellers will be displaced by 2100. Small-island states and East, Southeast and South Asia will be the biggest land-losers.
Average yields of wheat, rice and corn may fall by 2 per cent per decade, while demand for crops is likely to rise by up to 14 per cent by 2050 as population grows. The crunch will hit poor, tropical countries worst.
A “large fraction” of land and freshwater species may risk extinction, their habitat destroyed by climate change.
The quest for scarce goods – when food and food crops comprise an essential part of that quest – has been diminished in a number of ways in recent decades. We may see that reversed. Which means poorer nations in particular may resort to the most affordable means in the political mind of acquiring such scarce goods — war.
The scumbags who fund so-called climate skeptics, that is, the breed not already volunteering on their behalf out of sheer stubborn refusal to examine scientific study – will have to move their penthouse aeries further inland.
If you’re a dinosaur with a nickname as funky as “the chicken from hell,” you had better be able to back it up…A dinosaur called Anzu wyliei that scientists identified on Wednesday from fossils found in North Dakota and South Dakota does just that.
It had a head shaped like a bird’s, a toothless beak, an odd crest on its cranium, hands with big sharp claws, long legs for fast running and was probably covered in feathers.
It is the largest North American example of a type of bird-like dinosaur well known from Asia.
Its extensive remains offer a detailed picture of the North American branch of these dinosaurs that had remained mysterious since their first bones were found about a century ago, the scientists said.
What would someone think if they encountered this creature that lived 66 million years ago?…”I don’t know whether they would scream and run away, or laugh, because it is just an absurd-looking monster chicken,” said University of Utah paleontologist Emma Schachner, one of the researchers.
Anzu wyliei measured about 11 feet long, 5 feet tall at the hip and weighed about 440 to 660 pounds (200 to 300 kg), the researchers said…
Scientists think birds arose much earlier from small feathered dinosaurs. The earliest known bird is 150 million years old.
This dinosaur’s bird-like traits included a beak, hollow leg bones and air spaces in its backbone, paleontologist said Hans-Dieter Sues of the Smithsonian Institution’s National Museum of Natural History.
Its bizarre head crest resembled that of the cassowary, a flightless bird native to Australia and New Guinea.
Mostly dark meat, I hope.
Leaving a hair at a crime scene could one day be as damning as leaving a photograph of your face. Researchers have developed a computer program that can create a crude three-dimensional model of a face from a DNA sample.
Using genes to predict eye and hair colour is relatively easy. But the complex structure of the face makes it more valuable as a forensic tool — and more difficult to connect to genetic variation, says anthropologist Mark Shriver of Pennsylvania State University…who led the work…
Shriver and his colleagues took high-resolution images of the faces of 592 people of mixed European and West African ancestry living in the United States, Brazil and Cape Verde. They used these images to create 3D models, laying a grid of more than 7,000 data points on the surface of the digital face and determining by how much particular points on a given face varied from the average: whether the nose was flatter, for instance, or the cheekbones wider. They had volunteers rate the faces on a scale of masculinity and femininity, as well as on perceived ethnicity.
Next, the authors compared the volunteers’ genomes to identify points at which the DNA differed by a single base, called a single nucleotide polymorphism (SNP). To narrow down the search, they focused on genes thought to be involved in facial development, such as those that shape the head in early embryonic development, and those that are mutated in disorders associated with features such as cleft palate. Then, taking into account the person’s sex and ancestry, they calculated the statistical likelihood that a given SNP was involved in determining a particular facial feature.
This pinpointed 24 SNPs across 20 genes that were significantly associated with facial shape. A computer program the team developed using the data can turn a DNA sequence from an unknown individual into a predictive 3D facial model…Shriver says that the group is now trying to integrate more people and genes, and look at additional traits, such as hair texture and sex-specific differences…
At the moment, such genetic analyses are limited, imprecise. If you think scientists will leave it alone you don’t understand curiosity. If you think someone like the FBI or any other Alphabetoid snoop will leave it alone you don’t understand paranoia.