A Medley of Potpourri

Wednesday, January 29, 2014

First Weather Map of Brown Dwarf

ESO’s VLT charts surface of nearest brown dwarf

29 January 2014

ESO's Very Large Telescope has been used to create the first ever map of the weather on the surface of the nearest brown dwarf to Earth. An international team has made a chart of the dark and light features on WISE J104915.57-531906.1B, which is informally known as Luhman 16B and is one of two recently discovered brown dwarfs forming a pair only six light-years from the Sun. The new results are being published in the 30 January 2014 issue of the journal Nature.

Brown dwarfs fill the gap between giant gas planets, such as Jupiter and Saturn, and faint cool stars. They do not contain enough mass to initiate nuclear fusion in their cores and can only glow feebly at infrared wavelengths of light. The first confirmed brown dwarf was only found twenty years ago and only a few hundred of these elusive objects are known.

The closest brown dwarfs to the Solar System form a pair called Luhman 16AB [1] that lies just six light-years from Earth in the southern constellation of Vela (The Sail). This pair is the third closest system to the Earth, after Alpha Centauri and Barnard's Star, but it was only discovered in early 2013. The fainter component, Luhman 16B, had already been found to be changing slightly in brightness every few hours as it rotated — a clue that it might have marked surface features.

Now astronomers have used the power of ESO's Very Large Telescope (VLT) not just to image these brown dwarfs, but to map out dark and light features on the surface of Luhman 16B.

Ian Crossfield (Max Planck Institute for Astronomy, Heidelberg, Germany), the lead author of the new paper, sums up the results: “Previous observations suggested that brown dwarfs might have mottled surfaces, but now we can actually map them. Soon, we will be able to watch cloud patterns form, evolve, and dissipate on this brown dwarf — eventually, exometeorologists may be able to predict whether a visitor to Luhman 16B could expect clear or cloudy skies.”

To map the surface the astronomers used a clever technique. They observed the brown dwarfs using the CRIRES instrument on the VLT. This allowed them not just to see the changing brightness as Luhman 16B rotated, but also to see whether dark and light features were moving away from, or towards the observer. By combining all this information they could recreate a map of the dark and light patches of the surface.

The atmospheres of brown dwarfs are very similar to those of hot gas giant exoplanets, so by studying comparatively easy-to-observe brown dwarfs [2] astronomers can also learn more about the atmospheres of young, giant planets — many of which will be found in the near future with the new SPHERE instrument that will be installed on the VLT in 2014.

Crossfield ends on a personal note: “Our brown dwarf map helps bring us one step closer to the goal of understanding weather patterns in other solar systems. From an early age I was brought up to appreciate the beauty and utility of maps. It's exciting that we're starting to map objects out beyond the Solar System!”

Notes

[1] This pair was discovered by the American astronomer Kevin Luhman on images from the WISE infrared survey satellite. It is formally known as WISE J104915.57-531906.1, but a shorter form was suggested as being much more convenient. As Luhman had already discovered fifteen double stars the name Luhman 16 was adopted. Following the usual conventions for naming double stars, Luhman 16A is the brighter of the two components, the secondary is named Luhman 16B and the pair is referred to as Luhman 16AB.

[2] Hot Jupiter exoplanets lie very close to their parent stars, which are much brighter. This makes it almost impossible to observe the faint glow from the planet, which is swamped by starlight. But in the case of brown dwarfs there is nothing to overwhelm the dim glow from the object itself, so it is much easier to make sensitive measurements.

More information

This research was presented in a paper, “A Global Cloud Map of the Nearest Known Brown Dwarf”, by Ian Crossfield et al. to appear in the journal Nature.

The team is composed of I. J. M. Crossfield (Max Planck Institute for Astronomy [MPIA], Heidelberg, Germany), B. Biller (MPIA; Institute for Astronomy, University of Edinburgh, United Kingdom), J. Schlieder (MPIA), N. R. Deacon (MPIA), M. Bonnefoy (MPIA; IPAG, Grenoble, France), D. Homeier (CRAL-ENS, Lyon, France), F. Allard (CRAL-ENS), E. Buenzli (MPIA), Th. Henning (MPIA), W. Brandner (MPIA), B. Goldman (MPIA) and T. Kopytova (MPIA; International Max-Planck Research School for Astronomy and Cosmic Physics at the University of Heidelberg, Germany).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world's most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world's largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world's biggest eye on the sky”.

Contacts

Ian Crossfield
Max Planck Institute for Astronomy
Heidelberg, Germany
Tel: +49 6221 528 406
Email: ianc@mpia.de

Richard Hook
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email: rhook@eso.org

Is Industrial Hemp The Ultimate Energy Crop?

By Thomas Prade, Swedish University of Agricultural Sciences

Bioenergy is currently the fastest growing source of renewable energy. Cultivating energy crops on arable land can decrease dependency on depleting fossil resources and it can mitigate climate change.
But some biofuel crops have bad environmental effects: they use too much water, displace people and create more emissions than they save. This has led to a demand for high-yielding energy crops with low environmental impact. Industrial hemp is said to be just that.

Enthusiasts have been promoting the use of industrial hemp for producing bioenergy for a long time now. With its potentially high biomass yield and its suitability to fit into existing crop rotations, hemp could not only complement but exceed other available energy crops.
Hemp, Cannabis sativa, originates from western Asia and India and from there spread around the globe. For centuries, fibres were used to make ropes, sails, cloth and paper, while the seeds were used for protein-rich food and feed. Interest in hemp declined when other fibres such as sisal and jute replaced hemp in the 19th century.

Abuse of hemp as a drug led to the prohibition of its cultivation by the United Nations in 1961. When prohibition was revoked in the 1990s in the European Union, Canada and later in Australia, industrially used hemp emerged again.

This time, the car industry’s interest in light, natural fibre promoted its use. For such industrial use, modern varieties with insignificant content of psychoactive compounds are grown. Nonetheless, industrial hemp cultivation is still prohibited in some industrialised countries like Norway and the USA.

Energy use of industrial hemp is today very limited. There are few countries in which hemp has been commercialised as an energy crop. Sweden is one, and has a small commercial production of hemp briquettes. Hemp briquettes are more expensive than wood-based briquettes, but sell reasonably well on regional markets.

Large-scale energy uses of hemp have also been suggested.

Biogas production from hemp could compete with production from maize, especially in cold climate regions such as Northern Europe and Canada. Ethanol production is possible from the whole hemp plant, and biodiesel can be produced from the oil pressed from hemp seeds. Biodiesel production from hemp seed oil has been shown to overall have a much lower environmental impact than fossil diesel.

Indeed, the environmental benefits of hemp have been praised highly, since hemp cultivation requires very limited amounts of pesticide. Few insect pests are known to exist in hemp crops and fungal diseases are rare.

Since hemp plants shade the ground quickly after sowing, they can outgrow weeds, a trait interesting especially for organic farmers. Still, a weed-free seedbed is required. And without nitrogen fertilisation hemp won´t grow as vigorously as is often suggested.

So, as with any other crop, it takes good agricultural practice to grow hemp right.

*Hemp has a broad climate range and has been cultivated successfully from as far north as Iceland to warmer, more tropical regions. Flickr: Gregory Jordan*

Being an annual crop, hemp functions very well in crop rotations. Here it may function as a break crop, reducing the occurance of pests, particularly in cereal production. Farmers interested in cultivating energy crops are often hesitant about tying fields into the production of perennial energy crops such as willow. Due to the high self-tolerance of hemp, cultivation over two to three years in the same field does not lead to significant biomass yield losses.

Small-scale production of hemp briquettes has also proven economically feasible. However, using whole-crop hemp (or any other crop) for energy production is not the overall solution.
Before producing energy from the residues it is certainly more environmentally friendly to use fibres, oils or other compounds of hemp. Even energy in the fibre products can be used when the products become waste.

Recycling plant nutrients to the field, such as in biogas residue, can contribute to lower greenhouse gas emissions from crop production.

Sustainable bioenergy production is not easy, and a diversity of crops will be needed. Industrial hemp is not the ultimate energy crop. Still, if cultivated on good soil with decent fertilisation, hemp can certainly be an environmentally sound crop for bioenergy production and for other industrial uses as well.

Thomas Prade receives funding from the Swedish Farmers’ Foundation for Agricultural Research, the EU commission, the Skåne Regional Council and Partnership Alnarp.

This article was originally published at The Conversation.

Read the original article.

Monday, January 27, 2014

Study examines the development of children’s prelife reasoning

Boston University / January 28, 2014 / Cognition

Most people, regardless of race, religion or culture, believe they are immortal. That is, people believe that part of themselves–some indelible core, soul or essence–will transcend the body’s death and live forever. But what is this essence? Why do we believe it survives? And why is this belief so unshakable?

A new Boston University study led by postdoctoral fellow Natalie Emmons and published in the January 16, 2014 online edition of Child Development sheds light on these profound questions by examining children’s ideas about “prelife,” the time before conception. By interviewing 283 children from two distinct cultures in Ecuador, Emmons’s research suggests that our bias toward immortality is a part of human intuition that naturally emerges early in life. And the part of us that is eternal, we believe, is not our skills or ability to reason, but rather our hopes, desires and emotions. We are, in fact, what we feel.

Emmons’ study fits into a growing body of work examining the cognitive roots of religion. Although religion is a dominant force across cultures, science has made little headway in examining whether religious belief–such as the human tendency to believe in a creator–may actually be hard-wired into our brains.

“This work shows that it’s possible for science to study religious belief,” said Deborah Kelemen, an Associate Professor of Psychology at Boston University and co-author of the paper. “At the same time, it helps us understand some universal aspects of human cognition and the structure of the mind.”

Most studies on immortality or “eternalist” beliefs have focused on people’s views of the afterlife. Studies have found that both children and adults believe that bodily needs, such as hunger and thirst, end when people die, but mental capacities, such as thinking or feeling sad, continue in some form.
But these afterlife studies leave one critical question unanswered: where do these beliefs come from? Researchers have long suspected that people develop ideas about the afterlife through cultural exposure, like television or movies, or through religious instruction. But perhaps, thought Emmons, these ideas of immortality actually emerge from our intuition. Just as children learn to talk without formal instruction, maybe they also intuit that part of their mind could exist apart from their body.
Emmons tackled this question by focusing on “prelife,” the period before conception, since few cultures have beliefs or views on the subject. “By focusing on prelife, we could see if culture causes these beliefs to appear, or if they appear spontaneously,” said Emmons.

“I think it’s a brilliant idea,” said Paul Bloom, a Professor of Psychology and Cognitive Science at Yale who was not involved with the study. “One persistent belief is that children learn these ideas through school or church. That’s what makes the prelife research so cool. It’s a very clever way to get at children’s beliefs on a topic where they aren’t given answers ahead of time.”

Emmons interviewed children from an indigenous Shuar village in the Amazon Basin of Ecuador. She chose the group because they have no cultural prelife beliefs, and she suspected that indigenous children, who have regular exposure to birth and death through hunting and farming, would have a more rational, biologically-based view of the time before they were conceived. For comparison, she also interviewed children from an urban area near Quito, Ecuador. Most of the urban children were Roman Catholic, a religion that teaches that life begins only at conception. If cultural influences were paramount, reasoned Emmons, both urban and indigenous children should reject the idea of life before birth.

Emmons showed the children drawings of a baby, a young woman, and the same woman while pregnant, then asked a series of questions about the child’s abilities, thoughts and emotions during each period: as babies, in the womb, and before conception.

The results were surprising. Both groups gave remarkably similar answers, despite their radically different cultures. The children reasoned that their bodies didn’t exist before birth, and that they didn’t have the ability to think or remember. However, both groups also said that their emotions and desires existed before they were born. For example, while children generally reported that they didn’t have eyes and couldn’t see things before birth, they often reported being happy that they would soon meet their mother, or sad that they were apart from their family.

“They didn’t even realize they were contradicting themselves,” said Emmons. “Even kids who had biological knowledge about reproduction still seemed to think that they had existed in some sort of eternal form. And that form really seemed to be about emotions and desires.”

Why would humans have evolved this seemingly universal belief in the eternal existence of our emotions? Emmons said that this human trait might be a by-product of our highly developed social reasoning. “We’re really good at figuring out what people are thinking, what their emotions are, what their desires are,” she said. We tend to see people as the sum of their mental states, and desires and emotions may be particularly helpful when predicting their behavior. Because this ability is so useful and so powerful, it flows over into other parts of our thinking. We sometimes see connections where potentially none exist, we hope there’s a master plan for the universe, we see purpose when there is none, and we imagine that a soul survives without a body.

These ideas, while nonscientific, are natural and deep-seated. “I study these things for a living but even find myself defaulting to them. I know that my mind is a product of my brain but I still like to think of myself as something independent of my body,” said Emmons.

“We have the ability to reflect and reason scientifically, and we have the ability to reason based on our gut and intuition,” she added. “And depending on the situation, one may be more useful than the other.”

The Strategic Sourceror: 3 strategies for boosting sustainability across company operations

3 strategies for boosting sustainability across company operations

Strategic Sourceror on Friday, January 24, 2014

Segregating sustainable product sourcing practices from the larger company strategy and culture can be an easy mistake to make. However, businesses that have long been working to decrease the environmental impact of their procurement processes are well aware that isolated attempts at sustainability are often left behind or discredited over time. What many companies find they need is an emphasis on eco-friendliness that is central to their operations rather than peripheral.
While each firm's approach will differ based on its unique supplier network, some tried and true principles can be adapted and applied across the board. Here are three strategies that can help ensure sustainable sourcing is as effective and fully integrated as possible.

1. Increase communication

In order to avoid sustainability initiatives taking place in a vacuum, they need to be understood across the company. Visibility and communication have been a critical part of the success that Campbell Soup has enjoyed with its green initiatives. Dave Stangis, the company's vice president of public affairs and corporate responsibility, recently gave Sustainable Brands an instructive example of this principle.
"Someone in our communications department aims to tell a better sustainability story from our plant level; he's taken this objective to understand what sustainability work is happening in our 30 manufacturing plants around the world and help communicate that better externally," Stangis told the news source.

Without a solid understanding of sustainable practices internally, it's extremely difficult to communicate these efforts to the public in a cohesive way.

2. Make strategic partnerships

Firms also need to bear in mind that consumers will judge them based on the business relationships they foster. Growing companies looking to make acquisitions, for instance, need to do so with sustainability in mind. According to Sustainable Brands, Campbell chose to acquire Plum Organics, a well regarded company with a reputation for its green mission and employees' involvement in those goals.

3. Consider supplier practices

Lastly, it's key that companies consider the processes of their distribution and sourcing partners as an extension of their own operations. Suppliers need to be factored in when firms calculate their environmental impact and plan for improvements. Sustainability consultant Bill Barry recently began working with book publisher Macmillan to lower carbon emissions across the company's production chain, GreenBiz reported. Barry helped the firm calculate and plan to reduce its direct and indirect environmental impacts by 65 percent over the next five years. He did this by helping Macmillian restructure its paper milling, transportation and other partnerships.

Sustainable supplier management is critical, rather than optional, for companies that are serious about green procurement.

What Killed the Woolly Mammoth?

Professor finds some evidence to support a comet collision as the trigger for the Younger Dryas, which may have contributed to megafauna extinction

By Julie Cohen

Monday, January 27, 2014 - 11:30

Santa Barbara, CA

Could a comet have been responsible for the extinction of North America’s megafauna — woolly mammoths, giant ground sloths and saber-tooth tigers? UC Santa Barbara’s James Kennett, professor emeritus in the Department of Earth Science, posited that such an extraterrestrial event occurred 12,900 years ago.
Originally published in 2007, Kennett’s controversial Younger Dryas Boundary (YDB) hypothesis suggests that a comet collision precipitated the Younger Dryas period of global cooling, which, in turn, contributed to the extinction of many animals and altered human adaptations. The nanodiamond is one type of material that could result from an extraterrestrial collision, and the presence of nanodiamonds along Bull Creek in the Oklahoma Panhandle lends credence to the YDB hypothesis.

More recently, another group of earth scientists, including UCSB’s Alexander Simms and alumna Hanna Alexander, re-examined the distribution of nanodiamonds in Bull Creek’s sedimentological record to see if they could reproduce the original study’s evidence supporting the YDB hypothesis. Their findings appear in the Proceedings of the National Academy of Science.

“We were able to replicate some of their results and we did find nanodiamonds right at the Younger Dryas Boundary,” said Simms, an associate professor in UCSB’s Department of Earth Science.
“However, we also found a second spike of nanodiamonds more recently in the sedimentary record, sometime within the past 3,000 years.”

The researchers analyzed 49 sediment samples representing different time periods and environmental and climactic settings, and identified high levels of nanodiamonds immediately below and just above YDB deposits and in late-Holocene near-surface deposits. The late Holocene began at the end of the Pleistocene 11,700 years ago and continues to the present. The researchers found that the presence of nanodiamonds is not caused by environmental setting, soil formation, cultural activities, other climate changes or the amount of time in which the landscape is stable. The discovery of high concentrations of nanodiamonds from two distinct time periods suggests that whatever process produced the elevated concentrations of nanodiamonds at the onset of the Younger Dryas sediments may have also been active in recent millennia in Bull Creek.

“Nanodiamonds are found in high abundances at the YDB, giving some support to that theory,” Simms said. “However, we did find it at one other site, which may or may not be caused by a smaller but similar event nearby.”

A “recent” meteorite impact did occur near Bull Creek but scientists don’t know exactly when. The fact that the study’s second nanodiamond spike occurred sometime during the past 3,000 years suggests that the distribution of nanodiamonds is not unique to the Younger Dryas.

Contact Info:

Julie Cohen
julie.cohen@ucsb.edu
(805) 893-7220

- See more at: http://www.news.ucsb.edu/node/013899/what-killed-woolly-mammoth#sthash.Y5CsZSPd.dpuf

Sensitivity of carbon cycle to tropical temperature variations has doubled

Sensitivity of carbon cycle to tropical temperature variations has doubled
Jan 26, 2014
Earth

The tropical carbon cycle has become twice as sensitive to temperature variations over the past 50 years, new research has revealed.

The research shows that a one degree rise in tropical temperature leads to around two billion extra tonnes of carbon being released per year into the atmosphere from tropical ecosystems, compared with the same tropical warming in the 1960s and 1970s.

Professor Pierre Friedlingstein and Professor Peter Cox, from the University of Exeter, collaborated with an international team of researchers from China, Germany, France and the USA, to produce the new study, which is published in the leading academic journal Nature.

Existing Earth System Model simulations indicate that the ability of tropical land ecosystems to store carbon will decline over the 21st century. However, these models are unable to capture the increase in the sensitivity of carbon dioxide to tropical temperatures that is reported in this new study.

Research published last year by Professors Cox and Friedlingstein showed that these variations in atmospheric carbon dioxide can reveal the sensitivity of tropical ecosystems to future climate change.
Taken together, these studies suggest that the sensitivity of tropical ecosystems to climate change has increased substantially in recent decades.

Professor Cox, from the College of Engineering, Mathematics and Physical Sciences said "The year-to-year variation in carbon dioxide concentration is a very useful way to monitor how tropical ecosystems are responding to climate.

"The increase in carbon dioxide variability in the last few decades suggests that tropical ecosystems have become more vulnerable to warming".

Professor Friedlingstein, who is an expert in global carbon cycle studies added: "Current land carbon cycle models do not show this increase over the last 50 years, perhaps because these models underestimate emerging drought effects on tropical ecosystems".

The lead author of the study, Xuhui Wang of Peking University, added: "This enhancement is very unlikely to have resulted from chance, and may provide a new perspective on a possible shift in the terrestrial carbon cycle over the past five decades".

Explore further: Lungs of the planet reveal their true sensitivity to global warming

More information: A two-fold increase of carbon cycle sensitivity to tropical temperature variations, DOI: 10.1038/nature12915

Picture of how our climate is affected by greenhouse gases is a 'cloudy' one -- ScienceDaily

Date:

January 26, 2014

Source:

Hebrew University of Jerusalem

Summary:

Recent studies have revealed a highly complicated picture of aerosol-cloud interactions.

[Click to enlarge image]

Recent studies have revealed a highly complicated picture of aerosol-cloud interactions.Credit: © Maksim Shebeko / Fotolia

The warming effect of human-induced greenhouse gases is a given, but to what extent can we predict its future influence? That is an issue on which science is making progress, but the answers are still far from exact, say researchers from the Hebrew University of Jerusalem, the US and Australia who have studied the issue and whose work which has just appeared in the journal Science.

Indeed, one could say that the picture is a "cloudy" one, since the determination of the greenhouse gas effect involves multifaceted interactions with cloud cover.

To some extent, aerosols -- particles that float in the air caused by dust or pollution, including greenhouse gases -- counteract part of the harming effects of climate warming by increasing the amount of sunlight reflected from clouds back into space. However, the ways in which these aerosols affect climate through their interaction with clouds are complex and incompletely captured by climate models, say the researchers. As a result, the radiative forcing (that is, the disturbance to Earth's "energy budget" from the sun) caused by human activities is highly uncertain, making it difficult to predict the extent of global warming.

And while advances have led to a more detailed understanding of aerosol-cloud interactions and their effects on climate, further progress is hampered by limited observational capabilities and coarse climate models, says Prof. Daniel Rosenfeld of the Fredy and Nadine Herrmann Institute of Earth Sciences at the Hebrew University of Jerusalem, author of the article in Science. Rosenfeld wrote this article in cooperation with Dr. Steven Sherwood of the University of New South Wales, Sydney, Dr. Robert Wood of the University of Washington, Seattle, and Dr. Leo Donner of the US National Oceanic and Atmospheric Administration. .

Their recent studies have revealed a much more complicated picture of aerosol-cloud interactions than considered previously. Depending on the meteorological circumstances, aerosols can have dramatic effects of either increasing or decreasing the cloud sun-deflecting effect, the researchers say. Furthermore, little is known about the unperturbed aerosol level that existed in the preindustrial era. This reference level is very important for estimating the radiative forcing from aerosols.

Also needing further clarification is the response of the cloud cover and organization to the loss of water by rainfall. Understanding of the formation of ice and its interactions with liquid droplets is even more limited, mainly due to poor ability to measure the ice-nucleating activity of aerosols and the subsequent ice-forming processes in clouds.

Explicit computer simulations of these processes even at the scale of a whole cloud or multi-cloud system, let alone that of the planet, require hundreds of hours on the most powerful computers available. Therefore, a sufficiently accurate simulation of these processes at a global scale is still impractical.
Recently, however, researchers have been able to create groundbreaking simulations in which models were formulated presenting simplified schemes of cloud-aerosol interactions, This approach offers the potential for model runs that resolve clouds on a global scale for time scales up to several years, but climate simulations on a scale of a century are still not feasible. The model is also too coarse to resolve many of the fundamental aerosol-cloud processes at the scales on which they actually occur. Improved observational tests are essential for validating the results of simulations and ensuring that modeling developments are on the right track, say the researchers.

While it is unfortunate that further progress on understanding aerosol-cloud interactions and their effects on climate is limited by inadequate observational tools and models, achieving the required improvement in observations and simulations is within technological reach, the researchers emphasize, provided that the financial resources are invested. The level of effort, they say, should match the socioeconomic importance of what the results could provide: lower uncertainty in measuring human-made climate forcing and better understanding and predictions of future impacts of aerosols on our weather and climate.

Story Source:
The above story is based on materials provided by Hebrew University of Jerusalem. Note: Materials may be edited for content and length.

Journal Reference:

D. Rosenfeld, S. Sherwood, R. Wood, L. Donner. Climate Effects of Aerosol-Cloud Interactions. Science, 2014; 343 (6169): 379 DOI: 10.1126/science.1247490