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jueves, 24 de abril de 2014

NASA : Earth Science Radar Imaging Mission Travels to Central and South America

This photo of volcanoes in Guatemala was taken from NASA's C-20A aircraft during a four-week Earth science radar imaging mission deployment over Central and South America.

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Earth Science Radar Imaging Mission Travels to Central and South America

This photo of volcanoes in Guatemala was taken from NASA's C-20A aircraft during a four-week Earth science radar imaging mission deployment over Central and South America. The conical volcano in the center is "Volcan de Agua." The two volcanoes behind it are, right to left, "Volcan de Fuego" and "Acatenango." "Volcan de Pacaya" is in the foreground.

The radar imaging mission got underway in early April when the C-20A departed its base in Palmdale, Calif., to collect data over targets in the Gulf Coast area of the southeastern United States. The aircraft, a modified Gulfstream III, is carrying NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) instrument in a specialized pod. Developed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., UAVSAR measures ground deformation over large areas to a precision of 0.04 to 0.2 inches (0.1 to 0.5 centimeters).

The mission schedule calls for the aircraft to make stops in 10 international and U.S. locations, including the Gulf Coast. Research during the deployment is covering a variety of topics, including volcanoes, glaciers, forest structure, levees, and subsidence. It is also providing vegetation data sets for satellite algorithm development. The volcanoes of Central and South America are of interest because of the hazard they pose to nearby population centers. A majority of the research will focus on gathering volcano deformation measurements, with many flight lines being repeats from previous deployments. Surface deformation often precedes other signs of renewed volcanic activity.

Image Credit: NASA/Stu Broce

NASA

Guillermo Gonzalo Sánchez Achutegui

Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

domingo, 8 de diciembre de 2013

nsf.gov - National Science Foundation - Staple of recipe favorites--the tomato--reveals processes that maintain biodiversity

No hothouse plants: Study examines supermarket tomatoes' wild relatives, which live in Earth's most extreme environments

Wild tomatoes are small plants with big messages.
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December 5, 2013

The following is part twelve in a series on the National Science Foundation's Science, Engineering and Education for Sustainability (SEES) investment. Visit parts one, two, three, four, five, six, seven, eight, nine, ten and eleven in this series.

Tomatoes are in almost everything we eat, from salad and soup to chili and pizza. For some, tomato-based dishes are featured during the holiday season.

Most people don't realize, however, that there are more than a dozen wild tomato species, or that wild tomatoes grow in the deserts, rainforests and highlands of South America and on the Galapagos Islands.

These wild species don't have the big, bold fruits we're used to seeing in the supermarket, though. Wild tomato fruits are smaller, from the size of a pea to that of a large marble and are sometimes green and bitter when they're ripe.

But compared with their domesticated relatives, wild tomatoes are more diverse in many hidden and not-so-hidden ways.

Now scientists are using the genomes of wild tomatoes to study the processes that drive Earth's biodiversity.

Their goal is to learn how species cope with differences in climate and natural enemies, and what might happen in this time of environmental change.

Wild tomato genomes as a framework for understanding biodiversity

To study natural trait and genome diversity in wild tomatoes, scientists Leonie Moyle, David Haak and Matthew Hahn of Indiana University Bloomington received a grant from the National Science Foundation's (NSF) Dimensions of Biodiversity program.

Dimensions of Biodiversity is part of NSF's Science, Engineering and Education for Sustainability investment and is supported by NSF's Directorates for Biological Sciences and Geosciences.

Scientists funded through Dimensions of Biodiversity integrate genetic, taxonomic and functional approaches in their research.

"The resulting discoveries go beyond expanding our knowledge of the depth and breadth of life on Earth," says John Wingfield, NSF assistant director for Biological Sciences.

"They have the potential to revolutionize the way we manage agriculture, practice medicine, address global climate change and develop new technologies."

The award to Moyle's team funds sequencing of the complete set of all expressed genes (the transcriptome) in populations of wild tomato species.

"Variations within and between these wild tomato genomes can be compared by using the genome sequence of the domesticated tomato as a 'backbone,'"says Moyle.

By linking this genome-wide sequence data with information on wild tomato trait variation, the biologists hope to identify the genes responsible for adaptation to environmental change.

The research focuses on the role of drought and of defense against herbivores, or plant-eaters, in the diversity of wild tomatoes.

"These factors," says Haak, "capture two of the most important aspects of any plant's environment: climate and natural enemies."

Wild tomatoes: From hothouse to deep freeze

While domesticated tomatoes thrive only in agricultural irrigation, wild tomatoes live in some of the planet's most extreme environments.

They're among the few plants found in the driest place on Earth--the Atacama Desert in Chile. Other wild tomatoes blossom along the rocky, salty shores of the Galapagos Islands, and in the daily rains of Ecuador's rainforests.

But it's not just the climate in which they grow that varies among wild tomatoes.

The plants bristle with an array of natural defenses, from dense coverings of plant hairs to toxins deadly against insect attackers.

Measuring biodiversity in plant defenses

In a forthcoming paper in the journal Ecology, Haak, Moyle and colleagues document large differences in defenses among wild tomatoes.

They used bioassays--experiments in which living organisms are used to reveal the potency or concentration of a substance.

In this case, they fed leaf samples of different wild tomato species to tobacco hornworms.

The tobacco hornworm--also known as the tomato hornworm--is an enemy of both domesticated and wild tomatoes. It rapidly eats its way through the plants' leaves.

Each hornworm caterpillar was weighed before and after feeding to determine how much it had gained on a diet of wild tomato leaves.

Those tomatoes on which caterpillars gained little or no weight, says Haak, have more natural defenses than those on which the caterpillars gained weight.

In one wild tomato species, caterpillars lost significant weight; they refused to consume the plant's toxic leaves.

The researchers showed that the level of natural defense varies widely among wild tomato species.

"Although all wild tomatoes are closely related, these patterns of defense variation don't simply follow historical, evolutionary relationships," says Moyle. "The defense level of each wild tomato population is likely shaped by responses to local herbivores."

Linking biodiversity to genomics to understand environmental responses

Moyle and Haak are using DNA sequencing to look at the genes that are expressed differently in wild tomatoes with varying levels of natural defenses, and with differences in responses to drought.

Genes that are consistently up- or down-regulated in these conditions, says Moyle, can reveal the changes important for responding to and coping with environmental stresses.

"By linking data on DNA sequence variation, and on variation in gene expression, with wild tomatoes' responses to drought and natural enemies," she says, "we may find a powerful model for understanding the genetics of responses to environmental change."

The study could also uncover genetic variations helpful in improving domesticated tomatoes and their cultivated relatives, including potatoes and peppers.

"This research on tomatoes' wild relatives offers insights into the huge reservoir of genetic information available to ensure our future food security," says Simon Malcomber, lead NSF program director for Dimensions of Biodiversity.

"Tomatoes are one of the most widely consumed foods around the world," he says. "Studies such as this provide important information that could be used to improve herbivore resistance in crop cultivars."

Next time you're in the supermarket, tomatoes are worth a closer look. These common plants may offer a glimpse of our global food security, and of Earth's environmental future.

--	Cheryl Dybas, NSF (703) 292-7734 cdybas@nsf.gov

Investigators David Haak
Leonie Moyle
Matthew Hahn

Related Institutions/Organizations Indiana University

Related Programs Dimensions of Biodiversity

Total Grants $1,182,938

Related WebsitesIn race against time, NSF grants fund research on Earth's threatened biodiversity:

http://www.nsf.gov/news/news_summ.jsp?cntn_id=129242
Stemming the Tide of Biodiversity Loss on Earth:

http://www.nsf.gov/news/news_summ.jsp?cntn_id=125495&org=NSF&from=news
Diversity of Life on Earth: NSF Awards Grants for Study of Dimensions of Biodiversity:

http://www.nsf.gov/news/news_summ.jsp?cntn_id=122098
NSF Awards Grants to Study Dimensions of Earth's Biodiversity:

http://www.nsf.gov/news/news_summ.jsp?cntn_id=117811&org=NSF&from=news
Earth Week: A Stream Is a Stream Is a Stream: Or Is It?:

http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=123855&org=NSF
NSF Publication: "Discoveries in Sustainability":

http://www.nsf.gov/pubs/2012/disco12001/disco12001.pdf
Biodiversity of Earth's Richest Plant Kingdom Under Fire:

http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=122938&org=NSF
Wild tomatoes and domesticated tomatoes shown in different sizes

Wild tomatoes (right) differ in size, taste, color from domesticated tomatoes (left).
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Sheena Shah, a researcher at Indiana University Bloomington, labels wild tomatoes in a greenhouse.
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a wild tomato species with red fruits.

Solanum pimpinellifolium, a wild tomato species, has red, sweet fruits.
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First the sweet, then the bitter: The green-striped, wild tomato Solanum peruvianum.
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Researcher Amanda Garbers of Indiana University Bloomington in a lab

Researcher Amanda Garbers of Indiana University Bloomington studies the DNA of wild tomato plants.
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The National Science Foundation

Guillermo Gonzalo Sánchez Achutegui

Inscríbete en el Foro del blog y participa : A Vuelo De Un Quinde - El Foro!

martes, 3 de septiembre de 2013

nsf.gov - Electric fish may hold answers to better understanding of sensory abilities and movement

Research could lead to robots that can move and "sense" in highly cluttered and dark underwater environments

electric ghost knifefish from South America

This image is of the electric ghost knifefish, Apteronotus albifrons, from South America.
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September 3, 2013

The weakly electric fish, so named because it generates a weak electric field, can do some very cool things. Using sensors located all over its body, for example, it can detect prey or predators that interrupt its surrounding electric field. This enables it to hunt in the dark, as well as to avoid being hunted by piranhas and other visually-guided fish that share its home.

It also has a unique propulsion system that allows it to swim backwards; in fact, the fish can switch from full speed ahead to full speed in reverse in a fifth of a second.

Like many things in nature, the weakly electric fish, found in South America and Africa, is inspiring scientists trying to answer fundamental questions, in this case about sensory abilities and movement, with the goal of better understanding brain science and, ultimately, developing new technologies drawn from biology.

"The general question we are trying to understand is how the ability to sense the world is combined with the ability to move," says Malcolm MacIver, an associate professor of mechanical and biomedical engineering at Northwestern University. "What is the relationship between the space you are able to sense, and your mechanical abilities?"

Using the fish as a model system, he is deciphering the relationship between the sensory volume, that is, the space in which the fish perceives things in its field, and the motor volume, the space in which it moves. He calls the field of study "infomechanics."

To explain the relationship, he suggests comparing two starkly different scenarios one might encounter while driving a car. On a clear sunny day, most people drive in "deliberative" mode, meaning the driving conditions do not prompt any urgent responses to the circumstances or the driving environment. When encountering a dense fog, however, people typically switch to "reactive" mode--they slow down, for example, and become more alert to potential dangers on the road.

"When you're driving on a flat roadway on a sunny day, you can see a far distance ahead, and think about things, such as whether you're hungry or need to stop to use a restroom and want to get off an exit," he says. "In a fog, you don't have that luxury. The relationship between your sensory volume and where you are moving in your immediate future determines the kind of behavioral strategies you use."

How does this connect to the fish? "What the fish have allowed us to see is that most animals are in reactive mode, especially aquatic animals, because light doesn't travel very far in water, " he says. "Remember that our evolutionary ancestry started with animals in the water. My hypothesis is that something very important happened when we came up on land, as light can travel much farther in air than in water."

The weakly electric fish, a freshwater fish found in South America and Africa, has sensory receptors everywhere on its body, "which would be like us having eyeballs scattered across our body surface," he says. "The fish emits an electric field, and its sensors detect the field. So if something is out there, there is an interruption of the signal and the receptors pick up the distortion. It can do it in all directions."

The information researchers gain by studying the fish ultimately could have important applications, particularly in designing machines equipped with this so-called "electrosense," that is, the ability to maneuver and "sense" the world underwater with weak electric fields.

MacIver and his collaborators already have developed prototype robots that can move and "sense" in highly cluttered and dark underwater environments, and expect to see them in commercial use, including possibly by the US Navy, within the next few years.

"The underwater robots used during the Deepwater Horizon problem were held back by lack of maneuverability and sensor technology that could have helped them function well in turbid environments," he says, referring to the BP oil spill in 2010 in the Gulf of Mexico. "They were trying to operate in those huge plumes of oil mixed with water. You can't see in that. This technology has the potential to change all that."

MacIver also is working on a mechanical version of the fish's unique propulsion system.

"Most fish flap their fin, they wave the back portion of their body through the water, which propels them forward," he says. "Our fish doesn't swim that way. It keeps its body straight, and has a fin that goes almost of the full length of its body, down and along the belly. It ripples that fin, almost like a curtain in the wind. Using that, they are able to move in a highly acrobatic fashion."

Not only can it swim backwards, but "this fish can also move in all directions, including sideways and at an angle," he says. "It's like the helicopter of the water. If we had a device that could do this, we would have an aquatic helicopter."

They are working on it. "We have a bit further to go with the high maneuverability propulsion system," he says. "But we're getting there."

MacIver is conducting his research under a National Science Foundation (NSF) Faculty Early Career Development (CAREER) award, which he received in 2009 as part of NSF's American Recovery and Reinvestment Act. The award supports junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education, and the integration of education and research within the context of the mission of their organization. NSF is funding his work with about $1.25 million over four years.

In 2009, he also received the Presidential Early Career Award for Scientists and Engineers (PECASE), which recognized his interdisciplinary work on the biomechanical and neural basis of intelligence, spanning robotics, biomechanics, neurobiology, philosophy and computation, as well as for his innovative science outreach efforts that include Hollywood science-fiction advisory efforts, interactive art installations and blogging for Discover magazine.

MacIver uses three approaches in his work: mechanics and robotics for understanding the ways in which the body contributes to adaptive behavior; neurobiology for understanding the how sensory signals are processed for movement control; and computational modeling, for constructing supercomputer simulations of the body, nervous system, sensory signals and mechanical interactions with the world.

His collaborators include Kevin Lynch, a professor of mechanical engineering, Michael Peshkin, a professor of mechanical engineering, Neelesh Patankar, a professor of mechanical engineering, and David McLean, a professor of neurobiology, from Northwestern University; Julio Santos and James Solberg, of HDT Robotics, in Evanston, Ill.; George Lauder, a professor of zoology at the Museum of Comparative Zoology, Harvard University; Noah Cowan, a professor of mechanical engineering, and Eric Fortune, a professor of psychological and brain sciences at Johns Hopkins University.

MacIver also helped develop "Scale," a "singing electric fish" art installation that has appeared on exhibition in The Netherlands and in China. The multidisciplinary artwork was created by MacIver, visual artist Marlena Novak and composer and sound designer Jay Alan Yim, the latter two also from Northwestern. Twelve different species of electric fish from the Amazon River Basin comprise a "choir" whose sonified electrical fields provide the source tones for an immersive audiovisual experience.

"Every electric fish emits an electric field, and if you put it into a speaker, it's something you can hear," MacIver explains. "The fish aren't generating a sound, but if you dip the speaker leads into the water and amplify it, you can hear the audio equivalent of their electric field--an electric fish choir."

--	Marlene Cimons, National Science Foundation

Investigators Malcolm MacIver

Related Institutions/Organizations Northwestern University

Malcolm MacIver teaches mechanical and biomedical engineering at Northwestern University.
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Guillermo Gonzalo Sánchez Achutegui