Archive for March, 2013

Paloma T. Gonzalez-Bellido, who is now a postdoctoral scientist at the Marine Biological Laboratory (MBL), and colleagues from Howard Hughes Medical Institute, University of Minnesota, and Union College have been awarded a 2012 Cozzarelli Prize by the editorial board of Proceedings of the National Academy of Sciences (PNAS).

Gonzalez-Bellido and colleagues were honored for the “scientific excellence and originality” of their study of prey detection and interception in dragonflies.

The research was performed at Howard Hughes Medical Institute’s Janelia Farm Research Campus, where Gonzalez-Bellido was a postdoctoral scientist prior to joining the MBL’s Program in Sensory Physiology and Behavior in September 2011.

The study provides insight into basic visual-motor neural processing, and has implications for the development of “bioinspired” prosthetics for humans.

Green Darner Dragonfly Credit CC:Brian Robert Marshall

A green darner dragonfly, a member of the Aeshnidae family, in which Robert Olberg of Union College originally discovered the target-selective descending neurons (TSDNs). Credit: Brian Robert Marshall/Wikimedia

“I am honored to receive recognition for this work, for which we bridged the clinical and neuroethological fields, and developed new techniques,” says Gonzalez-Bellido. “This award has provided me with fuel to keep up the hard work and further my research plans.”

In order for a dragonfly to intercept its prey in midair (which dragonflies do with a 95% success rate), it needs to quickly track the prey and predict its future location. To understand how they undertake this complex task, Gonzalez-Bellido and her co-authors studied a small group of 16 motor neurons, called target-selective descending neurons (TSDNs), in the dragonfly Libellula luctuosa. These neurons, originally discovered by co-author Robert M. Olberg (Union College) in the green darner dragonfly, originate in the brain and extend to the thoracic ganglia, where the neural signal is interpreted and translated into wing muscle movements. Surprisingly, the scientists found that this small group of neurons can detect the direction of target prey with high accuracy and reliability across 360 degrees, and that this information is relayed from the brain to the wing motor centers in population vector form.

In 1988, co-author Apostolos Georgopoulos and his colleagues showed in monkeys that from the activity of neurons in the motor cortex, the population vector algorithm can predict the monkey’s upcoming arm movement. However, to achieve a more accurate prediction with this algorithm, upwards of 200 neurons were needed. Thus, the present discovery that a highly accurate neural code carrying information about target direction can be achieved with just 16 neurons is enlightening, and could have applications in the development of bioinspired robots. (Georgopolos is an MD-PhD at the University of Minnesota/Veterans Administration Medical Center who is interested in the development of prosthetics.)

Paloma-Gonzalez-Bellido Credit HHMI:Janelia Farm

Paloma Gonzalez-Bellido. Credit: HHMI/Janelia Farm

Randy Schekman, PhD, editor-in-chief of PNAS, describes the papers chosen for the Cozzarelli Prize as being “of exceptional interest… These papers are not merely technically superior but have had special impact and maybe novel techniques or novel applications of techniques, or very important discoveries.”

For this study, Gonzalez-Bellido and Trever Wardill (then at HHMI) developed a new protocol for labeling and confocal imaging of neurons in thick invertebrate tissue samples. In addition, her co-authors and former HHMI colleagues Hanchuan Peng and Jinzhu Yang developed a method for automatic 3D digital reconstruction (tracing) of neurons in microscopic images.

Gonzalez-Bellido sees the dragonfly as a promising model for understanding the evolution of neural systems. “It’s exciting that the same computation [the population vector algorithm] is used by monkeys and dragonflies for this task. Dragonflies belong to the most ancient groups of flying insects on earth, and they have changed little in 250 million years” she says.

The Cozzarelli Award was established in 2005 and named in 2007 to honor late PNAS editor-in-chief Nicholas R. Cozzarelli. Gonzalez-Bellido and the other awardees will be recognized at an awards ceremony during the National Academy of Sciences Annual Meeting on April 28, 2013, in Washington, D.C.

Out of more than 3,700 papers published in the journal last year, the editors selected Gonzalez-Bellido’s paper and five others for the Cozzarelli Prize.

Citation: 

Gonzalez-Bellido PT, Peng H, Yang J, Georgopoulos AP and Olberg RM (2012) Eight pairs of descending visual neurons in the dragonfly give wing motor centers accurate population vector of prey direction. PNAS 110: 696-701 /doi/10.1073/pnas.1210489109

A PNAS commentary on the paper is here.

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The U.S. Global Change Research Program (USGCRP) last week delivered its annual report to Congress for fiscal year 2013: Our Changing Planet.

The report highlights recent activities by 13 federal agencies to strengthen our scientific understanding of global changes including climate change, the threats and opportunities they present, and how they are likely to evolve over time.

In addition, Our Changing Planet showcases tangible results of work carried out by USGCRP agencies, including, for example, some of the most detailed, data rich maps of Alaskan permafrost ever generated; the most precise map ever produced of carbon stored in Earth’s tropical forests; critical information about the number and magnitude of extreme weather events in the United States; and updated maps that help gardeners and growers plan for harvesting seasons.

This report anticipates the USGCRP’s comprehensive Third National Climate Assessement, which will be released in early 2014. MBL Distinguished Scientist Jerry Mellilo chairs the advisory group that is preparing the National Climate Assessment, which presents the latest science about the current and projected effects of climate change across the United States.

billion-dollar-disaster-map-2012

The National Oceanic and Atmospheric Administration is announcing preliminary information that the U.S. experienced 11 disasters each costing over a billion dollars in losses in 2012. Of these 11 events, seven were severe weather or tornado events, and two were related to hurricanes/post tropical cyclones. The remaining two were the year-long drought and associated wildfires.

Contact: Terry Collins: 1-416-538-8712; tc@tca.ca or Diana Kenney, MBL: 508-289-7139; dkenney@mbl.edu

The Deep Carbon Observatory (DCO), a $500 million, 10-year international program that aims to reveal the quantity, movements, forms and origins of carbon inside our planet, has released its first major product after three years of inquiry: the volume Carbon on Earth.

Mitchell Sogin, director of the MBL’s Bay Paul Center for Comparative Molecular Biology and Evolution, co-chairs the DCO’s Deep Life Directorate. This group is discovering and describing the microbes and viruses that live in the deep ocean and beneath the ocean floor, and how they interact with deep carbon cycles. Guiding questions include:

* What’s down there?

* Do different geological environments host different populations of microbes and viruses?

* How do they adapt to extreme environmental conditions in order to survive?

* How does biological carbon link to the slower deep cycle, and is biologically processed carbon represented in deep-Earth reservoirs?

* Did deep biochemistry play a central role in life’s origins?

The variety of bacterial life at extreme high-pressure depths worldwide constitutes a subterranean “Galapagos,” DCO scientists say, adding that such subsurface life comprises a large portion of Earth’s total biomass — estimated in the late 1990s to be a third to a half of all life, though that figure is now considered high.

DNA has unearthed a marvel of diversity among deep single-celled micro-organisms, notably Archaea. And deep fungi-organisms with complex cell structures (eukaryotes) in the marine subsurface, have been a scientific surprise.

“Given the extraordinarily low rates of respiration, subsurface microbes must reproduce very slowly, if at all,” says Deep Life Directorate member Steven D’Hondt of the University of Rhode Island. “They take at least hundreds to thousands of years to reproduce and it’s conceivable that they live without dividing for millions to tens of millions of years,” he says. Still to be determined, Dr. D’Hondt notes, is the extent to which these organisms are “microbial zombies, incapable of being revived to a normal state.”

Sogin and MBL scientist Julie Huber, a microbial oceanographer who is also involved with the Deep Life Directorate, are this week attending the Deep Carbon Observatory’s International Science Meeting at the National Academy of Sciences in Washington, DC.

EarthsCarbonConcentrations_white_low

While we know approximately the thickness of Earth’s layers, the quantities of carbon below the surface in each layer remain a mystery. In fact, even the estimates of the carbon in the crust are quite uncertain. Fluxes between the layers complicate the mystery and the quest of the Deep Carbon Observatory. Credit: Deep Carbon Observatory

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