Clark University is an American private university and liberal arts college in Worcester, Massachusetts. Founded in 1887, it is the oldest educational institution founded as an all-graduate university. Clark now also educates undergraduates. The U.S. News & World Report ranked Clark 75th nationally in 2014, 83rd in 2013, and 95th in 2012. In 2013, Forbes ranked Clark University #51 in research.It is one of only three New England universities, along with Harvard and Yale, to be a founding member of the Association of American Universities, an organization of universities with the most prestigious profiles in research and graduate education. Clark withdrew its membership in 1999, citing a conflict with its mission; it is one of only four schools to do so.Clark is one of 40 schools profiled in the book Colleges That Change Lives by Loren Pope. Those who attend Clark University are colloquially called "Clarkies". Wikipedia.
Kudrolli A.,Clark University
Physical Review Letters | Year: 2010
We examine the persistent random motion of self-propelled rods (SPR) as a function of the area fraction and study the effect of steric interactions on their diffusion properties. SPR of length l and width w are fabricated with a spherocylindrical head attached to a beaded chain tail, and show directed motion on a vibrated substrate. The mean square displacement (MSD) on the substrate grows linearly with time t for
Stephens J.C.,Clark University
Wiley Interdisciplinary Reviews: Climate Change | Year: 2014
Government investment in carbon capture and storage (CCS) is a large and expensive fossil-fuel subsidy with a low probability of eventual societal benefit. Within the tight resource constrained environments that almost all governments are currently operating in, it is irresponsible to sustain this type of subsidy. CCS has been promoted as a 'bridging' technology to provide CO2 reductions until non-fossil-fuel energy is ramped up. But the past decade of substantial government investment and slow progress suggests that the challenges are many, and it will take longer to build the CCS bridge than to shift away from fossil-fuels. Optimism about the potential of CCS is based primarily on research on technical feasibility, but very little attention has been paid to the societal costs of governments perpetuating fossil-fuels or to the sociopolitical requirements of long-term regulation of CO2 stored underground. Deep systemic change is needed to alter the disastrous global fossil-fuel trajectory. Government investment in CCS and other fossil-fuel technologies must end so that the distraction and complacency of the false sense of security such investments provide are removed. Instead of continuing to invest billions in CCS, governments should invest more aggressively in technologies, policies, and initiatives that will accelerate a smooth transition to non-fossil-fuel-based energy systems. We need to divest from perpetuating a fossil-fuel infrastructure, and invest instead in social and technical changes that will help us prepare to be more resilient in an increasingly unstable and unpredictable future. © 2013 The Authors. WIREs Climate Change published by John Wiley & Sons, Ltd.
Foster S.A.,Clark University
Animal Behaviour | Year: 2013
Behavioural phenotypes are invariably plastic to some degree and are among the most labile of phenotypes. Some are acquired over the course of development in a particular environment (developmental plasticity), but most are elicited by an environmental trigger and are expressed only briefly, but often repeatedly, in the life of an organism (activational plasticity). Thus, individuals can possess the ability to perform a behaviour, but in the absence of the appropriate environmental stimulus, can fail to do so over the course of a lifetime. Rarely is the evolution of behavioural phenotypes explored in the larger context of the evolution of phenotypically plastic traits. Here I argue that the evolution of behavioural phenotypes, regardless of the nature of the plasticity expressed, can be examined in the same way as the evolution of other plastic traits. I first provide a conceptual review of the factors that can influence the evolution of plastic phenotypes and of the ways in which behavioural plasticity can influence the evolution of other aspects of phenotype. Many of the most compelling questions involve contrasting ancestral patterns of plasticity with those in derived populations or species, a particularly challenging problem in the case of phenotypic plasticity. I therefore provide an overview of the ways in which the influence of plasticity upon evolution can be addressed and then provide a review of examples from the literature that offer initial insights into the role of behavioural plasticity in evolution. The questions are exciting, the data limited, and, as I argue in closing, we need creative insights into the ways in which behavioural plasticity has evolved and has in turn influenced the evolution of other aspects of phenotype. © 2013 The Association for the Study of Animal Behaviour.
Agency: NSF | Branch: Standard Grant | Program: | Phase: PHYLOGENETIC SYSTEMATICS | Award Amount: 339.38K | Year: 2015
Fungi represent a major group of organisms that have profound economic and ecological impacts as decayers, pathogens (of plants and animals, including humans), and mutualists. Fungi are important sources of industrial bioproducts (antibiotics and enzymes) and they are critical to the fermentation industry, including biofuel production. However, much of the basic biology of fungi remains unknown, including knowledge on how fungi develop. This project will address the historical patterns and genetic mechanisms of developmental and morphological evolution in Agaricomycetes, which is a large group of fungi that includes gilled mushrooms, polypores, puffballs, and other complex forms. The results of this research will provide baseline information on the mechanisms of fungal development, as well as gene regulation and other processes of general significance for basic and applied fungal biology. This project will provide training for a PhD student, a Postdoctoral Fellow, and undergraduates. Education and outreach activities will make connections between art and science. Undergraduates with interests in art and science will engage in joint classes that develop observational skills and raise awareness about fungal biodiversity. The project will also create educational posters appropriate for high school students that illustrate fungal biology and general evolutionary principles. Posters and associated lesson plans will be made available for free download on a project web site and will be distributed through workshops at professional conferences for science educators.
Gene sequences for thousands of Agaricomycetes are available and complete genomes are available for over 90 species and increasing. However, these data have not been combined and queried to understand processes of fungal developmental evolution. The proposed research includes (1) macroevolutionary analyses, (2) phylogenomic analyses, and (3) developmental analyses. Macroevolutionary analyses will employ large-scale phylogenies (up to ca. 4000 terminals), drawing on publicly available data. Comparative methods will be used to perform ancestral state reconstruction, address directional trends, and test key innovation hypotheses. Phylogenomic analyses will identify shifts in copy number in gene families, such as transcription factors, hydrophobins, lectins and cell wall biogenesis enzymes, that may be correlated with evolution of complex forms. Developmental analyses will focus on Lentinus tigrinus, typically a gilled mushroom, but there is also a puffball-like secotioid form that is conferred by a recessive allele at a single locus (Sec). Two genome sequencs of L. tigrinus are available, one carrying the Sec+ allele and the other with the recessive sec allele. Bulk segregant analysis will be used to determine the identity of the secotioid locus. Pileus induction in L. tigrinus requires light and transcriptomic analyses will be used to compare gene expression patterns in vegetative mycelium and fruiting bodies produced in light or in darkness.
Agency: NSF | Branch: Continuing grant | Program: | Phase: MACROSYSTEM BIOLOGY | Award Amount: 72.07K | Year: 2015
Urban, suburban and exurban environments are important ecosystems and their extent is increasing in the U.S. The conversion of wild or managed ecosystems to urban ecosystems is resulting in ecosystem homogenization across cities, where neighborhoods in very different parts of the country have similar patterns of roads, residential lots, commercial areas and aquatic features. Funds are provided to test the hypothesis that this homogenization alters ecological structure and functions relevant to ecosystem carbon and nitrogen dynamics, with continental scale implications. The research will provide a framework for understanding the impacts of urban land use change from local to continental scales. The research encompasses datasets ranging from household surveys to regional-scale remote sensing across six metropolitan statistical areas (MSA) that cover the major climatic regions of the US (Phoenix, AZ, Miami, FL, Baltimore, MD, Boston, MA, St. Paul, MN and Los Angeles, CA) to determine how household characteristics correlate with landscaping decisions, land management practices and ecological structure and functions at local, regional and continental scales. This research will transform scientific understanding of an important and increasingly common ecosystem type (?suburbia?) and the consequences to carbon storage and nitrogen pollution at multiple scales. In addition, it will advance understanding of how humans perceive, value and manage their surroundings. The award will leverage an extensive, multi-scale program of education and outreach associated with ongoing LTER and/or ULTRA-EX projects. Activities include K-12 education and outreach to community groups, city/regional planners, natural history museums, state and local agencies and non-governmental organizations. Graduate students will participate in a Distributed Graduate Seminar in Sustainability Science (DGSS) initiated by NCEAS and the University of Minnesota Institute on Environment.
Agency: NSF | Branch: Standard Grant | Program: | Phase: CONDENSED MATTER PHYSICS | Award Amount: 376.62K | Year: 2015
The goal of the project is to develop a deep understanding of how thin elastic materials undergo buckling and creasing when subjected to twist. This knowledge is essential in obtaining the maximum functionality from devices made with new materials such as graphene sheets, nanotubes, semiconductor nanoribbons, and various biomaterials. Theoretical understanding of how thin sheets buckle and crease under stress is just in its infancy and these experimental studies will provide both guidance to and tests of these theories. Ultimately, this research will impact determination of strength and failure of thin materials under stress, and manufacturing of flexible structures and yarns by developing widely scalable techniques to pattern slender materials. The proposed research will also have a significant impact on educating students pursuing careers in STEM related disciplines. The dissertation research work of graduate students will be impacted by the grant. The project will enhance research experience of undergraduate students in the laboratory.
The goal of the project is to understand the buckling instabilities of thin elastic sheets subjected to twist which lead to wrinkling, stress focusing and energy condensation into creased structures. The fundamental role of elasticity and geometry in organizing the shape of the post-buckled structures will be investigated with experiments which will measure the shapes of the structures using micro x-ray tomography techniques and laser-aided optical imaging techniques. The phase diagram anticipated by a newly developed co-variant form of the Foppl-von Karman equations for thin plates will be investigated as function of sheet aspect ratio and elastic modulus. Development of minimal ridge structures and their interactions observed during the twisting of thin ribbon shapes will be used to study the scaling of the associated energy as a function of sheet thickness and applied deformation. Understanding formation of self-scrolled yarn and fabric structures under twist will provide an alternate reliable and efficient strategy to build mesoscale hierarchical structures with novel materials including graphene sheets, nanotubes, semiconductor nanoribbons, and biomaterials. Peer reviewed scientific publications will increase scientific knowledge in the field of condensed matter physics and will be disseminated on the web. Undergraduate and graduate students will be trained in the field of elasticity and soft matter, and in using sophisticated imaging techniques and analysis towards careers in STEM.
Agency: NSF | Branch: Standard Grant | Program: | Phase: AMO Theory/Atomic, Molecular & | Award Amount: 275.96K | Year: 2015
The goal of this project is to investigate quantum phases of strongly correlated systems with an emphasis on cold polar molecule setups. Strong correlations are at the core of many fascinating biological, chemical, and physical systems. The understanding of these systems is one of the major challenges facing physicists and a key issue in the community. Indeed, strongly correlated systems hold great potential in revolutionizing technological applications in medicine, communications, and computations. Within the framework of this project, novel extensions of a path-integral quantum Monte Carlo algorithm will be developed. The use of these Monte Carlo techniques will produce reliable and accurate results with controlled uncertainty. Unbiased theoretical predictions are timely and crucial to guide experimentalists in helping interpret experimental results and/or suggest observables. Moreover, the numerical results that will be obtained in this project can provide a platform for testing and validating analytical techniques. Indeed, these numerical techniques will also greatly contribute to the deeper understanding of certain classes of quantum many-body models which are, or will soon be, realizable in Atomic Molecular and Optical (AMO) experiments.
In this project, the investigator and her students will develop extensions of quantum Monte Carlo techniques needed to study strongly-correlated many-body systems with an emphasis on cold polar molecules in optical lattice setups. When free of the sign problem, quantum Monte Carlo is a powerful theoretical tool to study equilibrium properties of strongly interacting systems, especially in dimensions higher than one. In this project the investigator will use the Worm algorithm to study properties of many-body strongly correlated systems of bosonic polar molecules trapped in optical lattice geometries. Emphasis will be given on geometries for which the anisotropic nature of the dipolar interaction will play a major role in determining the phase diagram of the system. The geometries that will be studied include stacks of one- and two-dimensional layers, and two-dimensional gases where molecules have tilted dipole moments. Considering the recent successful experimental advances in cold polar molecule experiments, these phases are very likely to be within reach in the near future. Therefore, accurate and reliable theoretical predictions are timely and valuable to the experimental community. The single-worm algorithm is not suitable to study the quantum phases of these multimers. In this project, the investigator plans to develop three different non-trivial extensions of the single-worm algorithm: (i) N-distinguishable-worms, (ii) N-indistinguishable-worms, and (iii) a hybrid algorithm with both distinguishable and indistinguishable worms. These multi-worm algorithms for quantum systems will allow for the study of multimer formation in a rich variety of optical lattice dipolar systems.
Agency: NSF | Branch: Continuing grant | Program: | Phase: MACROSYSTEM BIOLOGY | Award Amount: 64.85K | Year: 2017
An apparent, but untested result of changes to the urban landscape is the homogenization of cities, such that neighborhoods in very different parts of the country increasingly exhibit similar patterns in their road systems, residential lots, commercial sites, and aquatic areas; cities have now become more similar to each other than to the native ecosystems that they replaced. This research builds on the team?s prior NSF funded research on the ?ecological homogenization? of the ?American Residential Macrosystem (ARM)? and specifically investigates factors that contribute to stability and/or changes in the ARM. The aim is to determine how factors that effect change?such as shifts in human demographics, desires for biodiversity and water conservation, regulations that govern water use and quality, and dispersal of organisms?will interact with factors that contribute to stability such as social norms, property values, neighborhood and city covenants and laws, and commercial interests. The project will determine ecological implications of alternative futures of the ARM for the assembly of ecological communities, ecosystem function, and responses to environmental change and disturbance at parcel (ecosystem), landscape (city), regional (Metropolitan Statistical Area) and continental scales. Five types of residential parcels as well as embedded semi-natural interstitial ecosystems will be studied, across six U.S. cities (Boston, Baltimore, Miami, Minneapolis-St. Paul, Phoenix, and Los Angeles). Education and outreach work will focus on K-12 teachers and students and on collaborative policy efforts with city, county, and state environmental managers.
This project investigates urbanization?s impact on the ecological homogenization of the American Residential Macrosystem (ARM) in terms of plant biodiversity, soil carbon and nitrogen cycle pools and processes, microclimate, hydrography, and land cover. This similarity of ecological characteristics is driven by complex and dynamic human actions at multiple scales?e.g., parcel, neighborhood, and region?that will shape the structure and function of the ARM over 50 to 100 year time frames, with potentially significant continental scale effects on ecological processes and environmental quality. This research addresses two core questions. First, what factors contribute to maintenance and change in the ARM? While this macrosystem is a relatively homogeneous mixture of grass lawns, shrubs, trees and impervious surfaces, there is a critical need to determine how drivers of change such as shifts in human population and ethnicity, increasing desires for biodiversity and water conservation, and regulations governing water use and quality will interact with stabilizing factors such as social norms, property values, neighborhood and city covenants and laws, and commercial interests. Researchers will test the hypothesis that that although dispersal from natural and interstitial areas, climate change, and changes in homeowner knowledge will promote ecological change; institutions, norms and values will function as counteracting, stabilizing forces on these ecological dynamics. This hypothesis will be tested by evaluating the factors that motivate change and stability at multiple scales. Results will be used to produce quantitative, data-based scenarios of future land-use patterns in the ARM. Second, what are the ecological implications of alternative futures of this macrosystem for community assembly and ecosystem function at parcel (ecosystem), landscape (city), regional (Metropolitan Statistical Area), and continental scales? The hypothesis to be tested is that management that promotes nutrient- and water-use efficient and wildlife-supporting plants as well as lower inputs of water and nutrients will give rise to greater regional biodiversity across trophic levels, higher nutrient retention, lower water use, and reduced runoff and losses of soil carbon and nitrogen from residential yards at the regional scale. Five types of residential parcels that vary in management goals and intensity and embedded semi-natural interstitial ecosystems will be studied in six U.S. cities across the U.S. (Boston, Baltimore, Miami, Minneapolis-St. Paul, Phoenix, and Los Angeles), to quantify influences on ecological dynamics. This information will be linked to land use scenarios to address the regional and continental-scale impacts of these effects. Three postdocs will be mentored as co-investigators on this project. The research program will also include interaction with municipal decision makers focused on sustainability and add a new ?Panel of Experts? feature to the YardMap citizen science program developed at Cornell University.
Agency: NSF | Branch: Continuing grant | Program: | Phase: Integrative Ecologi Physiology | Award Amount: 275.08K | Year: 2015
Wood (lignocellulose) is one of the most abundant carbon pools in terrestrial ecosystems. Fungal decomposition of wood is a critical component of the carbon cycle, impacts soil productivity, and has the potential to be exploited in the production of biofuels and other green technologies. The major wood-decaying fungi are mushroom-forming (Agaricomycetes). The physical characteristics and chemical composition of wood vary among plant species, and most wood-decaying Agaricomycetes have characteristic wood substrate ranges. However, it is not understood why individual species of wood decaying fungi tend to occur on specific plant hosts. This project will investigate the mechanisms of substrate specificity and substrate switching in wood-decaying Agaricomycetes using a combination of analyses of genes expressed during decay, and physical and chemical characterization of the decay process. Fungal enzymes that are involved in wood decay or degradation have potential applications in emerging bioprocesses, such as energy-related bioconversions, including biofuel production, and bioremediation. Enhanced understanding of the mechanisms that allow different species of fungi to exploit particular wood substrates could help guide development of genetic resources that could be used for such applied purposes. This project will support one Postdoctoral Fellow and two graduate students, and will provide training to undergraduates at three collaborating academic institutions in the US. To bring information about fungi and wood decomposition to a wide audience, this project will create interactive exhibits and develop accompanying public programs at the Worcester EcoTarium (http://www.ecotarium.org/), a science and nature museum which serves over 140,000 visitors annually including large numbers of students from regional public schools. Exhibits will illustrate fungal diversity, the decay process, and the role of fungi in the carbon cycle.
The proposed research will focus on four species of Agaricomycetes (with distinct substrate preferences) with available genome sequences. The fungi will be cultured on solid wafers of four different tree species (two conifers and two hardwoods). Transcriptome profiling will be performed with the Illumina HiSeq 2000 platform, focusing on genes encoding enzymes known or suspected to be involved in wood decay, as well as co-expressed genes of unknown function. Phylogenomic analyses will make use of all available genomes of wood-decaying Agaricomycetes, focusing on gene families that are likely to play a role in decay, as informed by expression profiles. Physical and chemical characteristics of decay will be addressed using microscopy, mass spectrometry, and chemical analyses of colonized substrates. The proposed research is a collaboration between researchers with expertise in fungal systematics and molecular evolution, wood decay and forest products pathology, fungal genomics, and genetics and biochemistry of decay systems. This project will capitalize on recent advances in genomics of wood-decaying basidiomycetes. It will provide insight into the functioning and evolution of fungi in forest ecosystems, and create a framework for future studies aimed at understanding the specific plant-derived compounds that affect expression of particular fungal genes.
Agency: NSF | Branch: Standard Grant | Program: | Phase: DYN COUPLED NATURAL-HUMAN | Award Amount: 377.78K | Year: 2015
Nearly half of the worlds population lives within 100 km of the coast, the area ranked as the most vulnerable to climate-driven sea-level rise (SLR). Projected rates of accelerated SLR are expected to cause massive changes that would transform both the ecological and social dynamics of low-lying coastal areas. It is thus essential to improve understanding of the sustainability of coupled coastal human-environment systems in the face of SLR. Salt marshes are intertidal habitats that provide a buffer for coastal communities to SLR and are also valued for many other ecosystem services, including wildlife habitat, nutrient cycling, carbon sequestration, aesthetics, and tourism. They are highly dynamic systems that have kept pace with changes in sea level over millennia. However, projected rates of SLR and increased human modification of coastal watersheds and shorelines may push marshes past a tipping point beyond which they are lost. Developing realistic scenarios of marsh vulnerability demands an integrated approach to understanding the feedbacks between the biophysical and social factors that influence the persistence of marshes and their supporting functions. This project will examine the comparative vulnerability of salt marshes to SLR in three U.S. Atlantic coastal sites that vary with respect to sediment supply, tidal range and human impacts. The research team will also address how feedbacks from potential adaptations influence marsh vulnerability, associated economic benefits and costs, and practical management decisions. Additional broader impacts include incorporating research results into curriculum used at local schools, an on-line cross-disciplinary graduate course, and on-going teacher-training programs, as well as training one postdoctoral researcher, four graduate students, and eight undergraduate researchers. This project is supported as part of the National Science Foundations Coastal Science, Engineering, and Education for Sustainability program - Coastal SEES.
This project leverages the long-term data, experiments and modeling tools at three Atlantic Coast Long-Term Ecological Research sites (in MA, VA, GA), and addresses the broad interdisciplinary question How will feedbacks between marsh response to SLR and human adaptation responses to potential marsh loss affect the overall sustainability of the combined socio-ecological systems? The goals of the project are to understand: 1) how marsh vulnerability to current and projected SLR, with and without adaptation actions, compares across biogeographic provinces and a range of biophysical and social drivers; and 2) which marsh protection actions local stakeholder groups favor, and the broader sustainability and economic value implications of feasible adaptation options. The biophysical research uses historical trends, point and spatial models to determine threshold and long-term responses of marshes to SLR. Social responses to marsh vulnerability are integrated with biophysical models through future scenario planning with stakeholders, economic valuation of marsh adaptation options, and focus groups that place the combined project results within a concrete policy planning context to assess how marshes fit into the larger view of coastal socio-ecological sustainability. This integrated approach at multiple sites along gradients of both environmental and human drivers will allow for general conclusions to be made about human-natural system interactions and sustainability that can be broadly applicable to other coastal systems.