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New Measurement Will Help Redefine International Unit of Mass

Using a state-of-the-art device for measuring mass, researchers at the National Institute of Standards and Technology (NIST) have made their most precise determination yet of Planck's constant, an important value in science that will help to redefine the kilogram, the official unit of mass in the SI, or international system of units. Accepted for publication (link is external) in the journal Metrologia, these new results come ahead of a July 1 international deadline for measurements that aim to redefine the entire SI in terms of fundamental constants of nature.

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The Black Forest and Climate Change

As the climate change progresses, droughts are expected to become more and more common and more intense in Europe, as in many parts of the globe. However, many plants are not able to handle this kind of climate.

This includes the Norway spruce, which is Germany's most important commercial tree species and accounts for the majority of trees in the Black Forest. Valentia Vitali and Prof. Dr. Jürgen Bauhusfrom the Chair of Silviculture at the University of Freiburg are thus studying other types of needle-leaved conifers to find alternatives. Conifers play a far greater role in commercial forestry and climate protection than broad-leaved trees. In their article "Silver Fir and Douglas Fir Are More Tolerant to Extreme Droughts than Norway Spruce in South-Western Germany" published in the journal Global Change Biology, the scientists concluded that the native silver fir and the Douglas fir, which was imported from the Americas, are suitable tree replacements for the Norway spruce in the long run.

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Peering into neural networks

Neural networks, which learn to perform computational tasks by analyzing large sets of training data, are responsible for today’s best-performing artificial intelligence systems, from speech recognition systems, to automatic translators, to self-driving cars.

But neural nets are black boxes. Once they’ve been trained, even their designers rarely have any idea what they’re doing — what data elements they’re processing and how.

Two years ago, a team of computer-vision researchers from MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL) described a method for peering into the black box of a neural net trained to identify visual scenes. The method provided some interesting insights, but it required data to be sent to human reviewers recruited through Amazon’s Mechanical Turk crowdsourcing service.

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To Buzz or to Scrabble? To Foraging Bees, That's the Question

Imagine going to the supermarket to stock up on groceries but coming home empty-handed because you just couldn't figure out how to work the shopping cart or figure out how to get to the ice cream tubs in the freezer aisle.

Welcome to the life of a bumblebee. 

Gathering sweet nectar from flowers, it turns out, is much more difficult than one might think, and it requires a lengthy learning process. By the time a bee has figured out how to efficiently pry open the lips of a snapdragon flower, for example, most likely it has made dozens, if not hundreds, of floral visits. 

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New Study of U.S. Residents Over 65 Underscores Link Between Air Pollution and Premature Death

A study of 60 million Americans over the age of 65 estimates that thousands of people are still dying prematurely each year because they are breathing polluted air.

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Veteran Ocean Satellite to Assume Added Role

A venerable U.S./European oceanography satellite mission with NASA participation that has expanded our knowledge of global sea level change, ocean currents and climate phenomena like El Niño and La Niña will take on an additional role next month: improving maps of Earth's sea floor.

The Ocean Surface Topography Mission (OSTM)/Jason-2 satellite, a partnership among NASA, the National Oceanic and Atmospheric Administration (NOAA), the French Space Agency Centre National d'Etudes Spatiales (CNES) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), marked its ninth year in orbit on June 20. Designed to fly three to five years, OSTM/Jason-2 has now completed more than 42,000 trips around our planet, contributing to a database of satellite altimetry that dates back to the launch of the U.S./French Topex/Poseidon satellite in 1992.

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Black carbon persists in snow and ice around the world

A new CU Boulder study comparing dissolved black carbon deposition on ice and snow in ecosystems around the world (including Antarctica, the Arctic and alpine regions of the Himalayas, Rockies, Andes and Alps) shows that while concentrations vary widely, significant amounts can persist in both pristine and non-pristine areas of snow.

Black carbon is the soot-like byproduct of wildfires and fossil fuel consumption, able to be carried long distances via atmospheric transport. Because these black particles absorb more heat than white snow, the study of black carbon concentrations in glaciers is important for predicting future melt rates.

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Self-powered system makes smart windows smarter

Smart windows equipped with controllable glazing can augment lighting, cooling and heating systems by varying their tint, saving up to 40 percent in an average building’s energy costs.

These smart windows require power for operation, so they are relatively complicated to install in existing buildings. But by applying a new solar cell technology, researchers at Princeton University have developed a different type of smart window: a self-powered version that promises to be inexpensive and easy to apply to existing windows. This system features solar cells that selectively absorb near-ultraviolet (near-UV) light, so the new windows are completely self-powered.

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Earning their stripes

Corey Filiaggi is describing the busy and collegial environment at the Berman Zebrafish Laboratory, where she’s spent the past three years working towards a master’s degree in Pathology. And it’s true that, only hours after a midnight return from the North Atlantic Zebrafish Research Symposium in Maine, the motley mix of undergraduate and graduate students and lab technicians milling about give off the vibe of a very science-focused village.

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Reptile Skin Grown in Lab for First Time, Helps Study Endangered Turtle Disease

Scientists recently reconstructed the skin of endangered green turtles, marking the first time that skin of a non-mammal was successfully engineered in a laboratory, according to a recently published U.S. Geological Survey study. In turn, the scientists were able to grow a tumor-associated virus to better understand certain tumor diseases.

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