Mass tree die-offs are sparking worries of fire in California’s Sierra Nevada range. An outbreak of bark beetles, along with persistent drought in the state, have caused many evergreen trees to wither and die.
The damage spread rapidly through the mountains in the fall of 2015 after favorable spring conditions (warm and dry) led to a surge in beetle populations, according to Zach Tane, a remote sensing analyst with the U.S. Forest Service (USFS). The beetles burrow under a tree’s bark and lay their eggs. Once they penetrate the tree’s armor (the bark), they begin to gnaw into its living tissue, the phloem.
“Needles don’t turn red the next day. It’s a slow process of the tree dying, and it has to do with life cycle of bark beetle and how long needles can persist in a green state,” said Tane. “As the population of beetles grows, they can overwhelm the natural defenses of a tree. There’s a tipping point—that’s what happened in Colorado and probably what’s happening here.”
In this scary time of global species extinctions and loss of biodiversity below “safe” levels, The Field Museum recently announced some good news: Luzon Island, an island the size of the Indiana in the Philippines, holds the greatest concentration of mammals. The pressing question now is will we be able to protect this rich biodiversity in time?
Two key climate change indicators -- global surface temperatures and Arctic sea ice extent -- have broken numerous records through the first half of 2016, according to NASA analyses of ground-based observations and satellite data.
Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record, which dates to 1880, according to scientists at NASA's Goddard Institute for Space Studies (GISS) in New York. The six-month period from January to June was also the planet's warmest half-year on record, with an average temperature 1.3 degrees Celsius (2.4 degrees Fahrenheit) warmer than the late nineteenth century.
Five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea ice extent since consistent satellite records began in 1979, according to analyses developed by scientists at NASA's Goddard Space Flight Center, in Greenbelt, Maryland. The one exception, March, recorded the second smallest extent for that month.
Tom Lehrer sang about poisoning them, but those pigeons in the park might be a good way to detect lead and other toxic compounds in cities. A new study of pigeons in New York City shows that levels of lead in the birds track with neighborhoods where children show high levels of lead exposure.
"Pigeons breathe the same air, walk the same sidewalks, and often eat the same food as we do. What if we could use them to monitor possible dangers to our health in the environment, like lead pollution?" said Rebecca Calisi, now an assistant professor in the Department of Neurobiology, Physiology and Behavior at the University of California, Davis, who conducted the study with undergraduate student Fayme Cai while at Barnard College, Columbia University. The work is published July 18 in the journal Chemosphere.
Decades after it was banned from paint and gasoline, lead pollution remains a significant concern. The New York City Department of Health and Mental Hygiene carries out routine screening of children in areas of the city identified as hot spots for lead contamination.
In cooperation with colleagues of the University of Rostock, the University of Luxembourg, the Max Delbrueck Center for Molecular Medicine, the Karlsruhe Institute of Technology and the University of Eastern Finland, the Munich Scientists have now published the results in the journal PLOS ONE. In 2015 they already showed that exposure to particle emissions from heavy fuel oil (HFO) and diesel fuel (DF) adversely affects human lung cells and is responsible for strong biological responses of the cells ("How Ship Emissions Adversely Affect Lung Cells"). For example, inflammatory processes are triggered that may influence the development of interstitial lung diseases. Now the team led by Professor Ralf Zimmermann has found in further studies that macrophages are also influenced by the exhaust gases. These are much more sensitive than lung epithelial cells and therefore react more strongly to exposure. Zimmermann is speaker of the international consortium Helmholtz Virtual Institute of Complex Molecular Systems in Environmental Health (HICE), head of the cooperation group Comprehensive Molecular Analytics (CMA) at Helmholtz Zentrum Muenchen and head of the Department of Analytical Chemistry at the University of Rostock.
The cost of offshore wind power in the North Sea is 30% lower than that of new nuclear, writes Kieran Cooke - helped along by low oil and steel prices, reduced maintenance and mass production. By 2030 the sector is expected to supply 7% of Europe's electricity. Output from the Dogger Bank project will be 1.2 GW (gigawatts) - enough to power more than a million homes. Next year, a 150-turbine wind farm off the coast of the Netherlands is due to start operating, and other schemes along the Dutch coast are in the works. Denmark, Sweden and Portugal are major investors in offshore wind, and China has ambitious plans for the sector. Wind farms - both onshore and offshore - are a key ingredient in renewable energy policy, and an important element in the battle against climate change. WindEurope, an offshore wind industry group, says that at the present rate of installations it's likely Europe will be producing about 7% of its electricity from offshore wind by 2030.
Offshore wind developers benefit from falling costs
By some calculations, all this building work would seem to make little economic sense. Fossil fuel prices are low on the world market, and constructing offshore wind farms several kilometres out at sea, in often treacherous conditions, has traditionally been an expensive business.
Hummingbirds are among nature's most agile fliers. They can travel faster than 50 kilometres per hour and stop on a dime to navigate through dense vegetation.
Now researchers have discovered that the tiny birds process visual information differently from other animals, perhaps to handle the demands of their extreme aerial acrobatics.
"Birds fly faster than insects and it's more dangerous if they collide with things," said Roslyn Dakin, a postdoctoral fellow in the UBC's department of zoology who led the study. "We wanted to know how they avoid collisions and we found that hummingbirds use their environment differently than insects to steer a precise course."
Note: Watch a video of the experiments here: https://youtu.be/6Z45BaswaOs
Scientists at UBC placed hummingbirds in a specially-designed tunnel and projected patterns on the walls to figure out how the birds steer a course to avoid collisions when they are in flight. They set up eight cameras to track the movement of hummingbirds as they flew through a 5.5-metre long tunnel.
On the surface, trees may look stationary, but underground their roots -- aided by their fungal allies -- are constantly on the hunt and using a surprising number of strategies to find food, according to an international team of researchers.
The precision of the nutrient-seeking strategies that help trees grow in temperate forests may be related to the thickness of the trees' roots and the type of fungi they use, according to David Eissenstat, professor of woody plant physiology, Penn State. The tree must use a variety of strategies because nutrients often collect in pockets -- or hot spots -- in the soil, he added.
"What we found is that different species get nutrients in different ways and that depends both on that species' type of root -- whether it's thin or thick -- and that species' type of mycorrhizal fungi, which is a symbiotic fungus," said Eissenstat. "What we show is that you really can't understand this process without thinking about the roots and the mycorrhizal fungi together."
Tree species with thicker roots -- for example, the tulip poplar and pine - avoid actively seeking nutrient hot spots and instead send out more permanent, longer-lasting roots. On the other hand, some trees with thinner roots search for nutrients by selectively growing roots that are more temporary, or by using their fungal allies to find hot spots.
Washington State University researchers have determined a key step in improving solid oxide fuel cells (SOFCs), a promising clean energy technology that has struggled to gain wide acceptance in the marketplace.
The researchers determined a way to improve one of the primary failure points for the fuel cell, overcoming key issues that have hindered its acceptance. Their work is featured on the cover of the latest issue of Journal of Physical Chemistry C.
Fuel cells offer a clean and highly efficient way to convert the chemical energy in fuels directly into electrical energy. They are similar to batteries in that they have an anode, cathode and electrolyte and create electricity, but they use fuel to create a continuous flow of electricity.
Fuel cells can be about four times more efficient than a combustion engine because they are based on electrochemical reactions, but researchers continue to struggle with making them cheaply and efficiently enough to compete with traditional power generation sources.
For the first time, researchers have successfully measured in detail the flow of solar energy, in and between different parts of a photosynthetic organism. The result is a first step in research that could ultimately contribute to the development of technologies that use solar energy far more efficiently than what is currently possible.
For about 80 years, researchers have known that photochemical reactions inside an organism do not occur in the same place as where it absorbs sunlight. What has not been known, however, is how and along what routes the solar energy is transported into the photosynthetic organism -- until now.
"Not even the best solar cells that we as humans are capable of producing can be compared to what nature performs in the first stages of energy conversion. That is why new knowledge about photosynthesis will become useful for the development of future solar technologies", says Donatas Zigmantas, Faculty of Science at Lund University, Sweden.
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