Tired of the age-old nature-versus-nurture debate? So are teachers and researchers of ADHD, or Attention-Deficit/Hyperactivity Disorder. It turns out that the academic performance of ADHD students is actually determined by a complex combination of nature and nurture.
A recent study found that for children with ADHD, some skills, such as reading, are largely determined by genetics. But in the case of math skills, a child’s home and school environment tend to play a bigger role.
At this point, the researchers can’t explain why.
Lee Thompson, a professor of Psychological Sciences at Case Western Reserve University led the study. He and his colleagues looked specifically at two symptoms associated with ADHD: inattention and hyperactivity.
270 pairs of 10-year-old twins were assessed. Some had signs of severe ADHD, while others showed few or none of the condition’s typical behaviors.
The researchers evaluated the children’s overall behavior, attention and activity. To measure the relationship between ADHD symptoms and academic abilities, they then looked at similarities between children’s skills and their respective genetic and environmental influences.
This was the first ADHD behavioral study that looked at genetic and environmental factors alike. This means both parents and teachers have their work cut out for them—just equally so.
The study was published this week in Psychological Science.
What's in these fracking fluids?
Between 2005 and 2009, Colorado used 1.5 million gallons of fracking fluid. That puts the state at number two in the nation according to a report by the House Energy and Commerce Committee. This has raised concerns about what chemicals are in the fluid, and if they affect drinking water.
Fracking, or hydraulic fracturing, pumps chemicals into oil reservoirs to increase the recovery rate. A nationwide investigation of 14 major oil and gas companies recently found that most fracking fluid contains a number of chemicals--some of them harmless, like gelatin, and some of them harmful, like carcinogenic benzene.
Authorities can demand disclosure of these chemicals, and some companies voluntarily submit the information to a statewide online database. The chemical contents of fracking fluids, though, are not public record.
State regulators have questions about how these chemicals may be affecting drinking water. Local environmental groups, along with House representatives, are now seeking disclosure requirements on fracking fluids in order to answer these questions.
The Scary Side of Superbugs
Antibiotic resistance is no longer limited to hasty prescriptions or hand soaps.
In New Delhi, India, antibiotic-resistant bacteria have been found in water used for drinking, washing, and cooking.
Researchers from Cardiff University tested the public water supply in India’s capital city. What Timothy Walsh and his colleagues found were bacteria known as “superbugs.”
These super species of bacteria contain a gene that makes them resistant to antibiotics. The gene’s secret weapon is an enzyme called New Delhi metallo-beta-lactamase, or NDM-1.
Bacteria that contain this enzyme are dangerous because the infections they cause, including cholera and dysentery, cannot be treated with antibiotics. In fact, Walsh says the only medication that can treat these resistant bacteria has toxic effects in humans.
The gene that produces NDM-1 was initially discovered in 2008, but its presence in New Delhi’s water supply indicates that the gene is spreading. The researchers found the gene in 14 different species of bacteria in New Delhi. It had not previously been seen in 11 of those species.
Newspapers have now reported the presence of the resistant bacteria in India, Pakistan, the United Kingdom, the United States, Canada, Japan and Brazil.
The results of the study were published in the online edition of the Lancet Infectious Disease Journal last Thursday.
Solar cells in the future may be more efficient, thanks to scientists at the Colorado School of Mines.
Physicist Mark Lusk and his colleagues used high-performance computers to show that tiny light-absorbing particles, called quantum dots, can use the sun’s energy to generate more electricity in solar cells and produce less unnecessary heat.
The work supports a controversial idea called multiple exciton generation. In solar cells, electrons obtain energy by absorbing a solar photon. The multiple exciton theory hypothesizes that a single energized electron could then transfer its energy to two or more electrons.
If the theory proves true we’ll be able to get more electricity out of the solar cell.
Lusk and his colleagues determined that quantum dots make this multiple exciton process more effective. They found that the quantum dots could be tuned to the wavelength – or color – of the incoming solar radiation. So a solar cell could be made of a collection of different sizes of quantum dots to harvest the rainbow of colors in the sun.
Experimentalists are now working to validate these computer simulations in the laboratory so they may be applied to solar cells. The results of the School of Mines study were published in the April issue of ACS Nano.