Archive for the ‘Science’ Category
Ke Li — Chris Goodfellow
Type 1 diabetes, which usually manifests during childhood, is caused by the destruction of beta-cells (β-cells). β-cells are a type of cell that normally resides in the pancreas and produces a hormone called insulin. Without insulin, the body’s organs have difficulty absorbing sugars, such as glucose, from the blood. Once a death sentence, the disease can now be managed with regular glucose monitoring and insulin injections. A more permanent solution, however, would be to replace the missing β-cells. But these cells are hard to come by, so researchers have looked towards stem cell technology as a way to make them…
One of the major challenges to generating large quantities of β-cells is that these cells have limited regenerative ability; once they mature it’s difficult to make more. So the team decided to go one step backwards in the life cycle of the cell.
The team first collected skin cells, called fibroblasts, from laboratory mice. Then, by treating the fibroblasts with a unique ‘cocktail’ of molecules and reprogramming factors, they transformed the cells into endoderm-like cells. Endoderm cells are a type of cell found in the early embryo, and which eventually mature into the body’s major organs—including the pancreas, the home of β-cells.
“Using another chemical cocktail, we then transformed these endoderm-like cells into cells that mimicked early pancreas-like cells, which we called PPLC’s,” said Gladstone Postdoctoral Scholar Ke Li, PhD, the paper’s lead author. “Our initial goal was to see whether we could coax these PPLC’s to mature into cells that, like β-cells, respond to the correct chemical signals and—most importantly—secrete insulin. And our initial experiments, performed in a petri dish, revealed that they did.”
The research team then wanted to see whether the same would occur in live animal models. So they transplanted PPLC’s into mice modified to have hyperglycemia (high glucose levels), a key indicator of diabetes.
“Importantly, just one week post-transplant, the animals’ glucose levels started to decrease, and gradually approached normal levels,” continued Dr. Li. “And when we removed the transplanted cells, we saw an immediate glucose spike, revealing a direct link between the transplantation of the PPLC’s and reduced hyperglycemia.”
But it was when the team tested the mice eight weeks post-transplant that they saw more dramatic changes: the PPLC’s had given rise to functional, insulin-secreting β-cells.
“These results not only highlight the power of small molecules in cellular reprogramming, and are proof-of-principle that could one day be used as a personalized therapeutic approach in patients,” explained Dr. Ding.
Bravo. I imagine pretty much everyone knows someone with Type 1 diabetes. I had friends in elementary school with what was then called childhood diabetes. I have friends since – who spent their childhood battling to get to something approaching normalcy in adult life.
All the symptomatic treatment in the world ain’t going to make folks’ lives easier than the potential of this cellular reprogramming.
From the HiRISE camera on NASA’s Mars Reconnaissance Orbiter…The image from the High Resolution Imaging Science Experiment camera on the agency’s Mars Reconnaissance Orbiter released Wednesday shows a crater about 100 feet in diameter at the center of a radial burst painting the surface with a pattern of bright and dark tones, NASA’s Jet Propulsion Laboratory in Pasadena, Calif., reported.
The impact that excavated this crater threw some material as far as 9.3 miles, JPL said.
The scar on the Red Planet’s surface appeared some time between imaging of this location by the orbiter’s Context Camera in July 2010 and again in May 2012.
I surely wish I was there. My idea of real adventure travel.
Could too much sugar be deadly? The biggest study of its kind suggests the answer is yes, at least when it comes to fatal heart problems.
It doesn’t take all that much extra sugar, hidden in many processed foods, to substantially raise the risk, the researchers found, and most Americans eat more than the safest amount…
Lead author Quanhe Yang of the U.S. Centers of Disease Control and Prevention called the results sobering and said it’s the first nationally representative study to examine the issue…
Yang and colleagues analyzed national health surveys between 1988 and 2010 that included questions about people’s diets. The authors used national death data to calculate risks of dying during 15 years of follow-up.
Overall, more than 30,000 American adults aged 44 on average were involved.
Previous studies have linked diets high in sugar with increased risks for non-fatal heart problems, and with obesity, which can also lead to heart trouble. But in the new study, obesity didn’t explain the link between sugary diets and death. That link was found even in normal-weight people who ate lots of added sugar…
Research has debunked parents’ concerns that the HPV vaccine encourages risky sexual behavior in teens.
In addition, women who had not had sex when vaccinated were not more likely to start having sex post-vaccination, according to research coming out of the Cincinnati Children’s Hospital Medical Center…
“We hope this study reassures parents, and thus improves HPV vaccination rates, which in turn will reduce rates of cervical and other cancers that can result from HPV infection,” said Jessica Kahn, MD…
Researchers studied more than 300 completed questionnaires from sexually experienced and inexperienced teens and young women between the ages of 13 and 21. The questionnaire asked for participants knowledge and attitudes about the HPV vaccine, beliefs about the need for safer sexual behaviors after vaccination, and about their sexual behaviors.
Participants were surveyed prior to vaccination, and given followup surveys two and six months after getting the vaccine. The responses showed that regardless of a teen’s beliefs regarding the HPV vaccine, it showed no link to subsequent sexual behavior nor did they change their sexual behavior based on whether the vaccine did or did not decrease the risk of sexually transmitted infections.
The vast majority of girls seemed to believe that it was still important to practice safe sex and did not believe that the vaccine protected against STIs.
HPV is a common STI that affects 7.5 million girls and young women in the United States between the ages of 14 and 24. The U.S. Advisory Committee on Immunization Practices recommends HPV vaccination for teenage girls and women between the ages of 11 and 26.
Unfortunately, that segment of the American population that learned about sex from a priest or religious pundit – instead of learning what modern science has proven in the last century or so – are not only handicapped, they seem bound and determined to screw up the lives of their children as well.
Silly and spooky beliefs about sex may be the stuff of late-night TV humor; but, in practice, we end up with one more layer of ignorance slathered over the consciousness of the next generation.
At least the study shows that the girls studied are brighter than the parents who oppose vaccination.
Previous studies from China, Spain, and the United States on genetically modified (GM) rice, cotton, and maize have concluded that the biodiversity of insects and related arthropods in GM crop fields was essentially the same as that among conventional crops. Now a new study from South Africa shows similar results…
“The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize,” the authors wrote. “Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance…”
“The results of our study indicate that arthropod diversity, even in high-input farming systems, is as high as in subsistence farming systems” said Dr. Johnnie van den Berg, a professor at North-West University and one of the co-authors of the article. “More recently, surveys of arthropod and plant beta-diversity inside and adjacent to maize fields have been completed during which 30,000 arthropods and 15,000 plant individuals were surveyed along a 1,000 kilometer transect. It seems that maize field diversity is homogenized and field margins had a high beta diversity,” he added.
Oh, the heartbreak for folks convinced this shouldn’t be so.
The sad bit is folks who try to cloak their Luddite predilection end up practicing something akin to creationist “science”. They first determine the result they seek – then, try to distort scientific study to suit that belief.
Needless to say, they rarely show up to challenge peer-reviewed work with competing studies. Anymore than the True Believers who latch onto these fears are likely to read the peer-reviewed studies in the first place.
Not-so-mellow-yellow — Owen Humphreys/PA
Perhaps I was naive, but when I discovered the extent of the chemical soup applied to typical fields I was astonished. As part of our ongoing investigations into the impact of pesticides on bees, we looked at 25 fields containing winter rapeseed or winter wheat during the 2012-13 growing season. For any particular field, the list of pesticides applied is worryingly long.
These are perfectly normal farms; not especially intensive, situated on the edge of the South Downs in East Sussex, an area of gentle hills, hedgerows and wooded valleys. Beautiful, rural England – Constable would have liked it here. But let’s look at it with a bee’s perspective rather than a painter’s eye.
Let’s look at one fairly typical field. The rapeseed crop, whose flowers the bees will feed on in season, is sown in late summer with a seed dressing containing the insecticide thiamethoxam. This is a systemic neonicotinoid, with exceedingly high toxicity to bees. Taken up into the plant, detectable levels will be in the nectar and pollen the bees gather.
In November, despite the protection supposedly offered by the neonicotinoid seed dressing the crop is sprayed with another insecticide, the endearingly named Gandalf. What harm could the wise old wizard possibly do? Gandalf contains beta-cyfluthrin, a pyrethroid. Pyrethroids are highly toxic to bees and other insects – killing insects is their job, after all – but as there should be no bees about in November that shouldn’t be a problem.
The following May, while flowering, the crop is sprayed with another pyrethroid, alpha-cypermethrin. Only weeks later the crop is blitzed with three more pyrethroids just for good measure – a real belt-and-braces approach. Why use one when three will do? The crop is still flowering at this point (it was a late year), and will be crawling with foraging bumblebees, hoverflies and other pollinators.
Between winter and summer, the crop is also treated with a barrage of herbicides, fungicides, molluscicides and fertilisers – 22 different chemicals in total. Most may have little toxicity to bees in themselves, but some, such as a group of fungicides (demethylation inhibiting or DMI fungicides), are known to interact with both neonicotinoids and pyrethroids, increasing their toxicity to bees.
So, when the fungicide prothioconazole is added to the mix tank that includes the year’s final application of chemicals, any feeding bee will be simultaneously exposed to a barrage of three pyrethroids, the thiamethoxam from the seed casing now in the nectar and pollen, and a fungicide that amplifies the toxicity of all these chemicals.
While farmers, agrochemical companies and food distributors say they haven’t a clue why bees are dying off at extinction levels.
One of the “ordinary” geothermal power plants
Can enormous heat deep in the earth be harnessed to provide energy for us on the surface? A promising report from a geothermal borehole project that accidentally struck magma – the same fiery, molten rock that spews from volcanoes – suggests it could.
The Icelandic Deep Drilling Project, IDDP, has been drilling shafts up to 5km deep in an attempt to harness the heat in the volcanic bedrock far below the surface of Iceland.
But in 2009 their borehole at Krafla, northeast Iceland, reached only 2,100m deep before unexpectedly striking a pocket of magma intruding into the Earth’s upper crust from below, at searing temperatures of 900-1000°C.
This borehole, IDDP-1, was the first in a series of wells drilled by the IDDP in Iceland looking for usable geothermal resources. The special report in this month’s Geothermics journal details the engineering feats and scientific results that came from the decision not to the plug the hole with concrete, as in a previous case in Hawaii in 2007, but instead attempt to harness the incredible geothermal heat…
…cementing a steel casing into the well, leaving a perforated section at the bottom closest to the magma. Heat was allowed to slowly build in the borehole, and eventually superheated steam flowed up through the well for the next two years…
The well funnelled superheated, high-pressure steam for months at temperatures of over 450°C – a world record. In comparison, geothermal resources in the UK rarely reach higher than around 60-80°C.
The magma-heated steam was measured to be capable of generating 36MW of electrical power. While relatively modest compared to a typical 660MW coal-fired power station, this is considerably more than the 1-3MW of an average wind turbine, and more than half of the Krafla plant’s current 60MW output.
Most importantly it demonstrated that it could be done. “Essentially, IDDP-1 is the world’s first magma-enhanced geothermal system, the first to supply heat directly from molten magma,” Elders said. The borehole was being set up to deliver steam directly into the Krafla power plant when a valve failed which required the borehole to be stoppered. Elders added that although the borehole had to plugged, the aim is to repair it or drill another well nearby.
Bravo! None of this response was as placid as it may sound written up for scientific journals. The facility faced the danger of eruption and fire throughout the experiment. Staff and scientists demonstrated their resourcefulness, resolving questions on the fly.
Nearly half of the buoys in the Tropical Atmosphere Ocean array have failed
An ocean-monitoring system that extends across the tropical Pacific is collapsing, depriving scientists of data on a region that influences global weather and climate trends.
Nearly half of the moored buoys in the Tropical Atmosphere Ocean (TAO) array have failed in the last two years, crippling an early-warning system for the warming and cooling events in the eastern equatorial Pacific, known respectively as El Niño and La Niña. Scientists are now collecting data from just 40% of the array.
“It’s the most important climate phenomenon on the planet, and we have blinded ourselves to it by not maintaining this array,” says Michael McPhaden, a senior scientist at…NOAA. McPhaden headed the TAO project before it was transferred out of NOAA’s research arm and into the agency’s National Weather Service in 2005.
…Researchers from around the world will meet next week at the Scripps Institution of Oceanography in La Jolla, California, to discuss possible solutions. NOAA has indicated that the agency will put additional resources into the program this coming year, but few expect that this will be enough to fully restore the array.
Wouldn’t it be a pleasant change if we repopulated Congress, the White House and relevant agencies with science-literate folks to a point where projects like this received adequate funding as readily as, say, subsidies for tobacco farmers or Exxon-Mobil?
I doubt if even a virtual sperm whale would be capable of holding its breath long enough to live to see that happen.
The average temperature of Earth maintained its warming trend in 2013, despite seasonal and regional variations that included a shrinking ice cap in the Arctic and a massively growing one in the southern hemisphere, U.S. scientists said on Tuesday.
NASA said the planet’s average temperature in 2013 was 58.3 degrees Fahrenheit – 14.6 degrees Celsius – tying 2006 and 2009 for the seventh warmest year since 1880 when global climate record-keeping began.
Using the same data but different analysis processes, the U.S. National Oceanic and Atmospheric Administration said 2013′s average temperature was 58.12 degrees Fahrenheit, which tied what NOAA considers to be the fourth hottest year on record.
The agencies differ in their analysis techniques. NASA for example uses more temperatures from Antarctica, but said the overall trend remains what has been measured every year since 1976 when global temperatures first surpassed the 20th Century’s global average of 57 degrees Fahrenheit – 13.9 degrees Celsius…
Global temperatures began climbing in the late 1960s, a phenomena that has been tied to heat-trapping greenhouse gases in Earth’s atmosphere.
NASA…said the amount of carbon dioxide in Earth’s atmosphere is higher now than at other time in the last 800,000 years.
Carbon dioxide levels were about 285 parts per million in 1880, the first year in the global temperature record. By 1960, levels reached 315 parts per million. In 2013, the amount of carbon dioxide peaked at more than 400 parts per million.
“The long term trends in climate are extremely robust,” Gavin Schmidt said. “There are times, such as today, when we can have snow, even in a globally warmed world [winter ain't dead - yet]. But the long-term trends are very clear. They are not going to disappear. It isn’t an error in our calculations.”
The question of climate change is one of those boundary layers separating ignorant from stupid. Climate is long-term phenomena. Meteorology is about weather, localized and regional phenomena – even when global forces are causative.
Given that most climate change-deniers barely understand the United States comprises only 6% of the Earth’s surface – and their interpretation of “climate” is characterized by the nearest FOX “news” broadcast – the operative word tends to remain “Stupid”.
Water in the form of ice is the most abundant solid material in the universe. Much of it was created as the byproduct of star formation, but not all. For now, John Bradley, of Lawrence Livermore National Laboratory, and his team may have discovered a new source of water in our solar system. His lab experiments reveal that solar winds may be creating water on interplanetary dust.
In the form of solar winds, the sun ejects high-speed charged particles in all directions. Bodies in the inner solar system get bombarded with these winds continuously in varying intensities.
Small bodies, such as dust particles or tiny asteroids, fall victim to these harsh winds. Large bodies, such as the Moon, that do not have enough gravity to hold onto an atmosphere fall victim to impact from tiny meteorites, as well as to solar winds. This form of bombardment causes a phenomenon called space weathering…
The modification leads to an imbalance in the structure of the particle sometimes causing occurrence of loosely-held oxygen and hydrogen atoms. This made scientists speculate that somewhere in these rims there is a chance that water could be formed…
That’s where Bradley’s work came into action. The team attempted to locate the formation of water using a highly-sensitive method of analysis called the valence electron energy-loss spectroscopy…
The idea was that, if water formed because of solar winds, it would be detected in only those samples that were exposed to hydrogen and not in those exposed to helium. And that is what happened. Bradley’s sensitive technique found presence of water repeatedly in only the hydrogen-exposed samples…
Bradley’s work implies that water molecules must have been forming for billions of years on interplanetary dust particles, on the moon and possibly on asteroids.
RTFA for the how and why and wherefores. Fascinating work.
Bradley doesn’t answer every question raised about the formation and distribution of water in solar systems, galaxies. The likelihood of several processes functioning independently and in concert is likely. Still – a qualitative addition to the body of astrophysical knowledge.