Nature: The color quality of television screens is about to be improved with the introduction of quantum dots. Tokyo-based Sony Corp announced that it is going to start integrating the novel technology into its flat screens. Quantum dots consist of nanometer-sized fluorescent particles of a semiconductor such as cadmium selenide. Whereas a bulk semiconductor emits a single color of light, a quantum dot can emit different colors. That is because researchers can manipulate a quantum dot’s shape and size, which in turn affects its quantum behavior and determines its color. Already employed in cell biology as fluorescent imaging labels for proteins and other molecules, quantum dots are just beginning to be exploited in electronics. Their use in TVs could significantly increase demand for the technology, which could cut costs and assist further development of other applications.
MIT Technology Review: Online shopping sites make use of various algorithms to suggest items for you to purchase based on what you and other users have purchased in the past. One effect of such recommendations is that some locales or products suffer from the sudden influx of people directed to them by the recommendation. To try to avoid this problem, a team of researchers led by Stanislao Gualdi of the University of Fribourg in Switzerland has applied a feature of particle physics. At the atomic level, particles tend to occupy the most energetically favorable states; but the number of particles that can occupy any given state depends on the type of particle. Gualdi drew a parallel between this concept and that of commercial products, which can be shared by either many or just a few people. The team developed a model that can limit the number of users allowed for a given product. When testing their model against empirical data of DVD rentals, they found that limiting rentals ensures that a wider range of DVDs get rented. And the more DVDs rented, the broader the range and accuracy of the ensuing recommendations. The overall effect was a healthier rental system. However, whether the model would work for actual retailers, who focus on maximizing their profits, is uncertain.
Washington Post: Black carbon soot has surpassed methane as a major contributor to human-caused climate change, according to a recent study published in the Journal of Geophysical Research: Atmospheres. Soot is created by diesel engines, wood-fired stoves, the burning of coal, and the like. Whether suspended in Earth’s atmosphere or coating snow and ice, black carbon particles absorb heat and thus can alter regional weather patterns. Reducing the amount of soot in the atmosphere would not only have an immediate cooling effect on the climate but also be beneficial to human health because soot particles cause heart and respiratory problems. The biggest contributor to climate change is still carbon dioxide emissions, however, which also must be reduced to “really solve the long-term climate problem,” said one of the paper’s lead authors, Tami Bond of the University of Illinois at Urbana-Champaign.
Ars Technica: A layer of gold nanodots is the basis of a new molecule detection technique that is sensitive enough to detect masses of just 10−15 g in a surface area of just 1 mm2. A team led by V. G. Kravets of the University of Manchester in the UK reached that level of sensitivity by putting a layer of graphene on top of the nanodots. The two layers of lattices allowed the researchers to reflect a very narrow range of photons from the material. The presence of hydrogen atoms attached to the layer of graphene significantly decreased the amount of reflected light. The researchers were able to determine the relationship between the mass of the hydrogen present and the decreased reflectivity. They then created another metamaterial using a layer of carboxylate and biotin (vitamin B7) on top of gold nanodots. Biotin binds with a protein that is commonly found in certain bacteria. The researchers measured the reflectivity of the surface before and after exposure to the protein, and determined that they could detect the presence of 1–4 protein molecules on a single nanodot. Detectors with this level of sensitivity could be very useful in medicine, pharmacology, and other areas where chemicals often have modest molecular weights.
New York Times: Under the headline “Deafness at doomsday,” theoretical physicist and science popularizer Lawrence M. Krauss argues in an op-ed that until “science and data become central to informing our public policies, our civilization will be hamstrung in confronting the gravest threats to its survival.” He sees “great peril” in a diminishment of scientists’ influence, which he suspects stems from the loss of the post–World War II direct responsibility of scientists for nuclear weaponry. In any case, he asserts, scientists’ voices are unheard concerning climate, nuclear proliferation, and “the potential creation of new and deadly pathogens.” Citing Iran, India, and Pakistan, he calls proliferation “as alarming as ever.” He observes that the Comprehensive Nuclear-Test-Ban Treaty is not ratified by the US despite advice from the National Academy of Sciences, and that another academy study, “on flaws in America’s costly ballistic missile defense program, has had little impact.” In Washington, Krauss writes, “ideological biases have become so ingrained . . . that scientific realities are subordinated to political intransigence.”