Records 201 to 210 of 294
On the U-M Gateway: King and Pascual's cholera prediction research
Wednesday, January 25, 2012
A new University of Michigan computer model of disease transmission in space and time can predict cholera outbreaks in Bangladesh up to 11 months in advance, providing an early warning system that could help public health officials there.
Watch for an EEB research feature coming soon about the paper by Professors Aaron King and Mercedes Pascual. U-M News Service press release.
Image: Dhaka, Bangladesh. Image courtesy of Flickr.com user eGuide Travel
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Michigan Fellow Pringle studies plant-animal microbe symbioses
Tuesday, January 24, 2012
Dr. Elizabeth Pringle joined EEB as a Michigan Fellow in the fall of 2011 from Stanford University, where she earned her Ph.D. in biology. Her appointment is shared with the School of Natural Resources and Environment.
The Michigan Society of Fellows selected 10 new fellows to serve three-year appointments as postdoctoral scholars and assistant professors. EEB currently has two Michigan Fellows, Pringle and Dr. Evan Economo.
Pringle studies the ecology and evolution of multi-species mutualisms. “The dynamics of interactions between species depend on environmental and historical context,” she explained. “I am interested in understanding how and why the costs and benefits of mutually beneficial interactions between species vary with context and what the consequences of this variation are for ecosystems and coevolutionary processes.”
According to Pringle’s research web page, “symbiotic ant-plant mutualisms, in which plants provide cavities and food for nesting ants and ants defend plants against herbivores, are wonderful systems for investigating variation in costs and benefits of mutualism. Much of my work in this area has focused on a specialized, symbiotic mutualism among the Neotropical tree Cordia alliodora, Azteca ants, and phloem-feeding scale insects. This system is widely distributed across tropical Latin America and is particularly common in seasonally dry tropical forests in Western Mexico and Central America. I have studied the effects of scale insects, ontogeny, geography, and population history on the interaction, and I am now working on the role of nutrient exchange among partners in generating variation in interaction outcomes, and on the consequences of such variation for the surrounding community.”
“I am so excited to be at Michigan and to have joined EEB and SNRE,” said Pringle. “The strength and diversity of research and teaching in these departments is truly impressive, and I'm thrilled to be a part of it. I look forward to many productive and fun interactions over the coming three years!”
The Society of Fellows received 1,062 applications last year, a record number and an increase of almost 20 percent over the previous year. The fellows were chosen for the importance and quality of their scholarship and for their interest in interdisciplinary work. During their tenure at U-M they will teach selected courses in their affiliated departments and continue their scholarly research.
"Fingerprinting" method tracks mercury emissions from coal-fired power plant
Wednesday, January 18, 2012
For the first time, the chemical "fingerprints" of the element mercury have been used by UM researchers to directly link environmental pollution to a specific coal-burning power plant.
The primary source of mercury pollution in the atmosphere is coal combustion. The U-M mercury-fingerprinting technique – which has been under development for a decade – provides a tool that will enable researchers to identify specific sources of mercury pollution and determine how much of it is being deposited locally.
"We see a specific, distinct signature to the mercury that's downwind of the power plant, and we can clearly conclude that mercury from that power plant is being deposited locally," said Joel Blum, the John D. MacArthur Professor of Earth and Environmental Sciences who is also a professor of ecology and evolutionary biology.
Blum is co-author of a paper published online Dec. 13, 2011 in the journal Environmental Science & Technology. The lead author of the paper is U-M doctoral candidate Laura Sherman, who works with Blum.
"This allows us to directly fingerprint and track the mercury that's coming from a power plant, going into a local lake, and potentially impacting the fish that people are eating," said Sherman, who has worked on the project for four years.
Mercury is a naturally occurring element, but some 2,000 tons are emitted to the atmosphere each year from human-generated sources such as incinerators, chlorine-producing plants and coal-fired power plants.
But results from the latest study by Sherman and her colleagues prove that mercury is deposited locally near coal-fired power plants and doesn't simply vanish into a global pool high in the sky. "It makes it hard to argue that there's no local deposition when we're seeing such unique signatures like this," Sherman said.
"This study represents the first use of stable mercury ratios to investigate the near-source mercury deposition resulting from coal combustion," Blum said. "We're very excited about this result, in part because it is technically difficult, and also because we've been told for years that it couldn't be done."
Image: Sampling tripod with funnels to collect precipitation. This study site was located on the Gulf of Mexico coast near Crystal River, Florida. Photo by Laura Sherman
U-M News Service press release
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NSF ant grant: revisiting the ants of Melanesia
Monday, January 16, 2012
The ants of Melanesia were famously studied by E.O. Wilson in the 1950s and inspired him to develop theories such as the taxon cycle and the “Equilibrium Theory of Island Biogeography.” The system has not been revisited until now.
Evan Economo, Michigan Fellow, and Professor Lacey Knowles have received a two-year grant from the National Science Foundation for nearly $380,000 for a project that builds upon Economo’s recent work on ant biodiversity in the Pacific Islands.
In the last few years, Economo and his collaborator Eli Sarnat, University of Illinois, have been collecting and reorganizing the ant biodiversity in the region. Their resulting book, “The Ants of Fiji,” will be published in 2012, providing a comprehensive treatment of the fauna of the archipelago.
There are 429 known ant genera, but over 10 percent of ant species belong to the single hyperdiverse genus Pheidole, according to Economo. Likewise, certain geographic areas (e.g. New Guinea) are diverse in species, phenotypes, and ecological strategies while others (e.g. Samoa) are much less diverse.
“The reasons for these patterns represent a puzzle for biologists,” he said. “This project investigates the macroevolutionary dynamics of Pheidole lineages in the island systems of the Indo-Pacific. The approach uses multilocus phylogenetics to reconstruct the evolutionary history of Pheidole, establishing when and where different species, phenotypes, and ecological strategies evolved. Using statistical and theoretical methods, this information will be used to test hypotheses for the forces shaping biodiversity.”
Economo and Sarnat previously analyzed the ecological structure of the entire ant fauna of the Fijian archipelago, and tested Wilson’s theory of the taxon cycle. So far, the theory performs remarkably well, he said, although other explanations are still possible for the same patterns. In particular, Pheidole, has had interesting phenotypic and ecological changes associated with an evolutionary radiation within Fiji.
“The goal of the current program is to look deeper into the evolutionary dynamics of Pheidole and test alternative theories for the processes generating these patterns,” said Economo.
“The project addresses a fundamental question of biology; whether the course of evolution and the biodiversity patterns we observe are inevitable or the outcomes of random chance. Addressing this question is a necessary step toward predicting the future dynamics of ecosystems in this time of unprecedented change. This is especially true for ants, one of the most ubiquitous and ecologically dominant animal groups on the planet. In the modern era, ‘invasive’ ants are now being transferred around the globe by humans and are causing damage to both economic interests and natural ecosystems. Understanding the historical dynamics of ant evolution will allow us to better predict the future evolutionary consequences of these modern colonizations.”
Image: Fijian ant species, Pheidole pegasus, from Fiji with an unusual "spinescent" morphology.
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Faculty cluster hire in sustainable and equitable food systems
Thursday, January 12, 2012
The Department of Ecology and Evolutionary Biology is involved in an ongoing junior-faculty cluster hire called Sustainable Food Systems.
The cluster will examine the path toward a sustainable and equitable food system, spanning the natural and social sciences. Professors John Vandermeer and Catherine Badgley are coordinating the cluster hire for EEB.
Sustainable Food Systems is part of a five-year, $30-million initiative announced in 2007 by U-M President Mary Sue Coleman to recruit scholars whose work crosses boundaries and to bring experts from different fields together to explore significant questions or complex problems.
According to the proposal, today’s global food system produces unprecedented quantities of food. Nevertheless, over one billion people lack adequate food to satisfy the minimum standards of nutrition, despite more than adequate global supplies, a perplexing pattern that has been evident for many years. Ironically, obesity has become a major health problem for some, even as hunger continues to plague others. Moreover, the modern agricultural system that developed during the past century is increasingly recognized as environmentally unsustainable, in many cases causing severe environmental degradation and substantial losses in biological diversity. Finally, for the consumers, food safety has emerged as a critical problem, and for producers – farmers and farm workers – workplace safety and unfair compensation threaten the sustainability of their livelihoods. A global food system that simultaneously produces hunger and obesity, that generates significant collateral environmental degradation and that compromises the wellbeing of consumer and producer alike challenges the academic community to engage in serious analysis and action.
This challenge has been partially met with the emergence of a new paradigm that emphasizes sustainability and social equity, rather than profit and production, at its core. Contributions to this new paradigm are emerging already from many sectors of society, especially at the grassroots level (e.g., local food systems, increased demand for organic and fair-trade products, reinvigoration of inner cities through urban agriculture, and new business models such as community-supported agriculture). The university is the ideal place to forge the intellectual foundation that will inform and guide the construction of a coherent path toward a sustainable and equitable food system, helping to reinvigorate rural and urban communities, promote environmental protection and enhance economies at state, national and international levels. The complex and multi-dimensional challenges of transforming the food system require an approach that engages multiple disciplines and considers systemic effects such as feedbacks and interdependencies.
“This is an exciting time to expand the faculty interested in sustainable food systems. The student interest is tremendous and there are many opportunities for research and engagement,” said Badgley.
The faculty proposed for this cluster will be located in EEB, the School of Natural Resources and Environment, the School of Public Health, the Urban and Regional Planning Program of Taubman College of Architecture and Urban Planning, and the Ross School of Business in collaboration with the Center for the Study of Complex Systems. In EEB, the focus will be on the evolutionary or ecological bases of food-production systems. Together with faculty already working on related topics in these and other units, the proposed cluster will create an interdisciplinary program that will provide opportunities for a new generation of natural and social scientists, as well as applied scholar-practitioners. The cluster will combine disciplinary specialization with commitment to interdisciplinary research on the food system in relation to the environment, human health and equity.
Photos: A coffee farmer planting a new coffee seedling in Mexico and a banana vendor in a city market in Havana, Cuba
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New U-M "Flume Room" contains 150 mini Huron Rivers
Monday, January 09, 2012
More than 3,000 gallons of Huron River water were trucked to the University of Michigan campus recently to create 150 mini-Hurons that are used to study how environmental changes affect freshwater habitats like rivers and streams.
The artificial streams are called flumes, and U-M's new $1 million "Flume Room" is in the basement of the Dana Building, home to the School of Natural Resources and Environment. The U-M flume lab is the largest facility of its kind in North America, and possibly the world.
"We're taking little pieces of the Huron River – the water, the rocks, the bacteria, the algae, the insects and other small invertebrates that inhabit the stream – and we're placing them into these 150 small flumes. We try to mimic all the river conditions we possibly can," said Professor Bradley Cardinale of ecology and evolutionary biology and natural resources and environment, principal investigator of the flume project.
Running an experiment 150 times in 150 identical flumes provides what researchers call high replication, which enables them to precisely estimate how different environmental stresses – such as pollution, species invasions and extinctions, climate change and erosion – affect the river's health.
"The rationale for doing this is that the world's rivers and streams are being exposed to all sorts of human-induced stresses, and we can't possibly address them all – we don't have enough money, we don't have enough people and we don't have enough time," Cardinale said. "The point of this project is to figure out our top priorities. This project is going to tell us the top stressors we should be focusing on."
U-M News Service press release and video
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Rapid rise in wildfires in Canada? Ecologists show for first time threshold value for natural wildfires
Monday, January 09, 2012
Large forest regions in Canada are apparently about to experience rapid change. Based on models, scientists can now show that there are threshold values for wildfires just like there are for epidemics. Large areas of Canada are apparently approaching this threshold value and may in future exceed it due to climate change.
As a result both the area burnt down annually and the average size of the fires would increase, according to Professor Mercedes Pascual, Richard Zinck, former visiting research investigator, and their colleague at the Helmholtz Centre for Environmental Research (UFZ), Volker Grimm. Their findings were published in the December issue of the journal The American Naturalist. The strategies for combating wildfires in large parts of Canada should therefore be reconsidered.
Small changes in the fire propagation parameters have a great impact on the size of the fires. Gradual changes, such as those which can be expected due to climate change, can therefore result in an abrupt and sharp increase in the size of the fires.
The scientists were also interested in the parallels with disease propagation. Prevention strategies, which reduce combustible material, are in a way similar to the vaccinations which are used against the spread of diseases such as the measles. Here too there is a threshold value above which a disease spreads and below which it falls. Other modelers from the UFZ were therefore able to turn this theoretical threshold value into a practical value. With foxes it was shown that only 60 per cent had to be vaccinated against rabies in order to successfully combat the disease. The scientists therefore hope to find out more in future studies which cover both disciplines.
The research was widely covered by the media. Helmholtz Centre for Environmental Research – UFZ press release
Photo: © skylight, Fotolia.com
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On the U-M Gateway: Acid rain poses a previously unrecognized threat to Great Lakes sugar maples
Thursday, December 22, 2011
The number of sugar maples in Upper Great Lakes forests is likely to decline in coming decades, according to Professor Don Zak and his colleagues, due to a previously unrecognized threat from a familiar enemy: acid rain. Zak is co-author of an article published online Dec. 8, 2011 in the Journal of Applied Ecology. Watch for a research feature coming soon.
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Cheng selected for Graham Fellowship
Wednesday, December 21, 2011
EEB graduate student Susan Cheng was awarded a two-year Graham Doctoral Sustainability Fellowship for 2012 for her proposal, "Can forest carbon sequestration be sustained under climate change? Coupling atmospheric and ecological sciences to inform forest management."
The project is based at the U-M Biological Station investigating how forest carbon uptake will change as forest communities and atmospheric conditions shift under changing climate. “I will be using NASA's remotely-sensed atmospheric data, UMBS ecosystem-level measurements, and field-collected tree cores to study how light and water limitations influence forest carbon uptake.”
“As a fellow, I'm also hoping to organize a workshop that will bring Michigan foresters, Graham Fellows, and natural and social scientists together to discuss reciprocal needs, transfer knowledge, and inform future forest management.”
Cheng will receive up to $50,000 over two years. Cheng is working with Professor Knute Nadelhoffer, director of UMBS, collaborators from The Ohio State University, and Professor Allison Steiner from U-M's Department of Atmospheric, Oceanic, and Space Science.
The Graham Environmental Sustainability Institute is a collaborative partnership of schools, colleges and units across U-M. The institute fosters cross-disciplinary collaboration to create and disseminate knowledge and to offer solutions related to complex sustainability issues. On a broader scale, the Graham Doctoral Fellowship Program helps to create a community of scholars, wherein the fellows can collaborate, engage, and interact during their doctoral studies and into the future. During the fellows' time on campus, academic associations are cultivated through monthly seminars, annual retreats, workshops, and other Graham-sponsored forums.
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Goldberg on sabbatical; Hunter is acting chair
Tuesday, December 20, 2011
Professor and Chair Deborah Goldberg is officially and happily on sabbatical through May 1, 2012.
She will spend time in Tucson, Ariz. in the Sonoran Desert and work on several writing projects, including an update of her textbook, “Population Ecology,” with Professor John Vandermeer, articles about her ongoing research on wetland invasions, and a synthesis paper about the mechanisms underlying general patterns in beta diversity in plants. Beta diversity is the turnover in species composition over space or different environments.
Professor Mark Hunter takes the reins as acting chair during the next four months. “The department will be in fantastic hands with Mark Hunter, he is an experienced administrator who cares deeply about the future of the department,” said Goldberg.
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Records 201 to 210 of 294