"Using off-the-shelf products labeled free of these chemicals for even three days can lead to a big drop in exposure levels, study shows". "Using cosmetics and personal care products that don’t contain certain hormone-disrupting ingredients for only three days, women can significantly reduce their exposure to these chemicals, according to a study published today in Environmental Health Perspectives. The study by researchers at the University of California Berkeley, California Department of Public Health, and Clinica de Salud del Valle de Salinas, measured levels of four commonly used cosmetics ingredients known to be endocrine disrupters —phthalates, parabens, triclosan, and oxybenzone — in 100 Latina teens before and after they began to use off-the shelf products labeled as free of these ingredients. These chemicals are widely used in personal care products and cosmetics, including sunscreens, soaps, hair products, and perfume. All have been shown in laboratory studies to interfere with the endocrine system, which produces hormones that help regulate development, reproduction, and metabolism as well as cardiovascular, immune, and neurological system functions. This is the first such study to show that simply by using products labeled to be free of these chemicals, personal exposure levels can be significantly reduced."
News Article | April 18, 2016
The research team from the Australian National University (ARC Centre of Excellence CUDOS) and the University of California Berkeley demonstrated a new artificial material, or metamaterial, that glows in an unusual way when heated. The findings could drive a revolution in the development of cells which convert radiated heat into electricity, known as thermophotovoltaic cells. "Thermophotovoltaic cells have the potential to be much more efficient than solar cells," said Sergey Kruk, Ph.D. from the ANU Research School of Physics and Engineering. "Our metamaterial overcomes several obstacles and could help to unlock the potential of thermophotovoltaic cells." Thermophotovoltaic cells have been predicted to be more than two times more efficient than conventional solar cells. They do not need direct sunlight to generate electricity, and instead can harvest heat from their surroundings in the form of infrared radiation. They can also be combined with a burner to produce on-demand power or can recycle heat radiated by hot engines. The team's metamaterial, made of tiny nanoscopic structures of gold and magnesium fluoride, radiates heat in specific directions. The geometry of the metamaterial can also be tweaked to give off radiation in specific spectral range, in contrast to standard materials that emit their heat in all directions as a broad range of infrared wavelengths. This makes it ideal for use as an emitter paired with a thermophotovoltaic cell. The project started when Kruk predicted the new metamaterial would have these surprising properties. The ANU team then worked with scientists at the University of California Berkeley, who have unique expertise in manufacturing such materials. "To fabricate this material the Berkeley team were operating at the cutting edge of technological possibilities," Dr Kruk said. "The size of individual building block of the metamaterial is so small that we could fit more than twelve thousand of them on the cross-section of a human hair." The key to the metamaterial's remarkable behaviour is its novel physical property, magnetic hyperbolic dispersion. Dispersion describes the interactions of light with materials and can be visualized as a three-dimensional surface representing how electromagnetic radiation propagates in different directions. For natural materials, such as glass or crystals the dispersion surfaces have simple forms, spherical or ellipsoidal. The dispersion of the new metamaterial is drastically different and takes hyperbolic form. This arises from the material's remarkably strong interactions with the magnetic component of light. The efficiency of thermovoltaic cells based on the metamaterial can be further improved if the emitter and the receiver have just a nanoscopic gap between them. In this configuration, radiative heat transfer between them can be more than ten times more efficient than between conventional materials.
For the first time, scientists have been able to weave a material at molecular level. The research is led by University of California Berkeley, in cooperation with Stockholm University. The new material is presented in the scientific journal Science. Weaving is a well-known way of making fabric, but has until now never been used at the molecular level. Scientists have now been able to weave organic threads into a three-dimensional material, using copper as a template. The new material is a COF, covalent organic framework, and is named COF-505. The copper ions can be removed and added without changing the underlying structure, and at the same time the elasticity can be reversibly changed. “It almost looks like a molecular version of the Vikings chain-armor. The material is very flexible,” says Peter Oleynikov, researcher at the Department of Materials and Environmental Chemistry at Stockholm University. COFs are like MOFs’ porous three-dimensional crystals with a very large internal surface that can adsorb and store enormous quantities of molecules. A potential application is capture and storage of carbon dioxide, or using COFs as a catalyst to make useful molecules from carbon dioxide. The research is led by Professor Omar Yaghi at University of California Berkeley. At Stockholm University Professor Osamu Terasaki, PhD student Yanhang Ma, and Oleynikov have contributed to determine the structure of COF-505 at atomic level from a nano-crystal, using electron crystallography methods. “It is a difficult, complicated structure and it was very demanding to resolve. We’ve spent lot of time and efforts on the structure solution. Now we know exactly where the copper is and we can also replace the metal. This opens up many possibilities to make other materials,” says Ma, a student at the Department of Materials and Environmental Chemistry at Stockholm University. Release Date: January 22, 2016 Source: Stockholm University
News Article | April 4, 2016
Mexico City has found a way to tackle with the escalating problem of smog and air pollution: a stricter car ban from April 5 to June 30. However, past studies and policies have shown that it might not work. In the city of 20 million, considered one of the worst polluted in the world by the United Nations, the previous measure is to ban vehicles on the road on certain days of the week, unless they present an exempt sticker, which shows the car has undergone testing for smog and obtained a low emission score. The new car ban, announced by the country’s environmental commission, covers even sticker-carrying vehicles once a week and a Saturday every month. It will prevail until late June or the start of the rainy season. Added measures include policy changes that will potentially lower the maximum pollution level, as air contaminants are believed to continue accumulating during the dry season. However, is the new “no circulation” policy limiting the number of cars on the road bound to work or fail? Mexico City has implemented similar laws in place since the 1980s, all deemed by experts as a failure. Moreover, previous studies have already taken a look at why ordering cars off the road are not guaranteed to work. Lucas Davis, an energy researcher at the University of California Berkeley who has analyzed the city’s similar attempts in the past, found that these programs actually increased air pollution in the long term. One reason is the hassle factor: people are forced to take public transportation more often, which is slow, inconvenient, and a not-so-tempting prospect given the city buses’ reputation of being dangerous. So what they do is to find other ways to ride cars: investing in second family cars with a different license plate number, taking taxis, or booking an Uber or Lyft service. “I just think that once people become drivers in Mexico City they don’t go back,” says Davis. He adds that the inconvenience could reach more than $300 million a year or $130 for every vehicle owner. While the current “no circulation” rule, too, addressed some loopholes in preceding ones through technology, the city has to get to a point where it is politically ready, added Davis. Just two weeks ago, Mexico City announced emergency ozone status after it suffered the highest air pollution levels since the 1980s. The World Air Quality Index has also identified parts of the city with unhealthy air quality, which can lead to health consequences comprising a range of respiratory conditions. In 2010, studies highlighted savings of more than $760 million annually through slashing pollution by a mere 10 percent. These gains include preventing about 33,000 emergency room cases due to respiratory disease.
The Rochester/Adobe model mixes the two approaches that are often used in image captioning: the "top-down" approach, which starts from the "gist" of the image and then converts it into words, and the "bottom-up" approach, which first assigns words to different aspects of the image and then combines them together to form a sentence. The Rochester/Adobe model is currently beating Google, Microsoft, Baidu/UCLA, Stanford University, University of California Berkeley, University of Toronto/Montreal, and others to top the leaderboard in an image captioning competition run by Microsoft, called the Microsoft COCO Image Captioning Challenge. While the winner of the year-long competition is still to be determined, the Rochester "Attention" system - or ATT on the leaderboard - has been leading the field since last November. Other groups have also tried to combine these two methods by having a feedback mechanism that allows a system to improve on what just one of the approaches would be able to do. However, several systems that tried to blend these two approaches focused on "visual attention," which tries to take into account which parts of an image are visually more important to describe the image better. The Rochester/Adobe system focuses on what the researchers describe as "semantic attention." In a paper accepted by the 2016 IEEE Conference on Computer Vision and Pattern Recognition (CVPR), entitled "Image Captioning with Semantic Attention," computer science professor Jiebo Luo and his colleagues define semantic attention as "the ability to provide a detailed, coherent description of semantically important objects that are needed exactly when they are needed." "To describe an image you need to decide what to pay more attention to," said Luo. "It is not only about what is in the center of the image or a bigger object, it's also about coming up with a way of deciding on the importance of specific words." For example, take an image that shows a table and seated people. The table might be at the center of the image but a better caption might be "a group of people sitting around a table" instead of "a table with people seated." Both are correct, but the former one also tries to take into account what might be of interest to readers and viewers. Computer image captioning brings together two key areas in artificial intelligence: computer vision and natural language processing. For the computer vision side, researchers train their systems on a massive dataset of images, so they learn to identify objects in images. Language models can then be used to put these words together. For the algorithm that Luo and his team used in their system, they also trained their system on many texts. The objective was not only to understand sentence structure but also the meanings of individual words, what words often get used together with these words, and what words might be semantically more important. A closely related paper on video captioning by Luo, graduate student Yuncheng Li, and their Yahoo Research colleagues Yale Song, Liangliang Cao, Joel Tetreault, andLarry Goldberg. "TGIF: A New Dataset and Benchmark on Animated GIF Description," will also be featured as a "Spotlight" presentation at CVPR. Explore further: A picture is worth 1000 words, but how many emotions?