Physical Sciences and Mathematics Commons^™

Spin Exchange Interaction In Substituted Copper Phthalocyanine Crystalline Thin Films, Naveen Rawat, Zhenwen Pan, Cody J. Lamarche, Anthony Wetherby, Rory Waterman, Takahisa Tokumoto, Judy G. Cherian

College of Arts and Sciences Faculty Publications

All rights reserved. The origins of spin exchange in crystalline thin films of Copper Octabutoxy Phthalocyanine (Cu-OBPc) are investigated using Magnetic Circular Dichroism (MCD) spectroscopy. These studies are made possible by a solution deposition technique which produces highly ordered films with macroscopic grain sizes suitable for optical studies. For temperatures lower than 2K, the contribution of a specific state in the valence band manifold originating from the hybridized lone pair in nitrogen orbitals of the Phthalocyanine ring, bears the Brillouin-like signature of an exchange interaction with the localized d-shell Cu spins. A comprehensive MCD spectral analysis coupled with a molecular …

Rapid Biotic Homogenization Of Marine Fish Assemblages, Anne E. Magurran, Maria Dornelas, Faye Moyes, Nicholas J. Gotelli, Brian Mcgill

College of Arts and Sciences Faculty Publications

The role human activities play in reshaping biodiversity is increasingly apparent in terrestrial ecosystems. However, the responses of entire marine assemblages are not well-understood, in part, because few monitoring programs incorporate both spatial and temporal replication. Here, we analyse an exceptionally comprehensive 29-year time series of North Atlantic groundfish assemblages monitored over 5° latitude to the west of Scotland. These fish assemblages show no systematic change in species richness through time, but steady change in species composition, leading to an increase in spatial homogenization: the species identity of colder northern localities increasingly resembles that of warmer southern localities. This biotic …

Climate Change Sentiment On Twitter: An Unsolicited Public Opinion Poll, Emily M. Cody, Andrew J. Reagan, Lewis Mitchell, Peter Sheridan Dodds, Christopher M. Danforth

College of Engineering and Mathematical Sciences Faculty Publications

The consequences of anthropogenic climate change are extensively debated through scientific papers, newspaper articles, and blogs. Newspaper articles may lack accuracy, while the severity of findings in scientific papers may be too opaque for the public to understand. Social media, however, is a forum where individuals of diverse backgrounds can share their thoughts and opinions. As consumption shifts from old media to new, Twitter has become a valuable resource for analyzing current events and headline news. In this research, we analyze tweets containing the word "climate" collected between September 2008 and July 2014. Through use of a previously developed sentiment …

Ecological And Biogeographic Null Hypotheses For Comparing Rarefaction Curves, Luis Cayuela, Nicholas J. Gotelli, Robert K. Colwell

College of Arts and Sciences Faculty Publications

The statistical framework of rarefaction curves and asymptotic estimators allows for an effective standardization of biodiversity measures. However, most statistical analyses still consist of point comparisons of diversity estimators for a particular sampling level. We introduce new randomization methods that incorporate sampling variability encompassing the entire length of the rarefaction curve and allow for statistical comparison of i ≥ 2 individual-based, sample-based, or coverage-based rarefaction curves. These methods distinguish between two distinct null hypotheses: the ecological null hypothesis (H0eco) and the biogeographical null hypothesis (H0biog). H0eco states that the i samples were drawn from a single assemblage, and any differences …

Temporal Overlap And Co-Occurrence In A Guild Of Sub-Tropical Tephritid Fruit Flies, Gleidyane N. Lopes, Miguel F. Souza-Filho, Nicholas J. Gotelli, Leandro J.U. Lemos, Wesley A.C. Godoy, Roberto A. Zucchi

College of Arts and Sciences Faculty Publications

Studies of community assembly have emphasized snapshot comparisons of spatially replicated samples from "natural" assemblages. Agro-ecosystems are characterized by relatively little habitat heterogeneity and no dispersal barriers for actively flying insects. Therefore, dynamic patterns of species segregation and aggregation are more likely to reflect the direct or indirect effects of species interactions. We studied the temporal organization of a guild of 21 congeneric species of Anastrepha that colonized fruit orchards in Monte Alegre do Sul, São Paulo, Brazil. This assemblage also included the introduced Mediterranean fruit fly Ceratitis capitata. One hundred six consecutive weekly censuses (11 Jan 2002-16 Jan 2004) …

Forecasting The Response Of Earth's Surface To Future Climatic And Land Use Changes: A Review Of Methods And Research Needs, Jon D. Pelletier, A. Brad Murray, Jennifer L. Pierce, Paul R. Bierman, David D. Breshears, Benjamin T. Crosby, Michael Ellis, Efi Foufoula-Georgiou, Arjun M. Heimsath, Chris Houser, Nick Lancaster, Marco Marani, Dorothy J. Merritts, Laura J. Moore, Joel L. Pederson, Michael J. Poulos, Tammy M. Rittenour, Joel C. Rowland, Peter Ruggiero, Dylan J. Ward, Andrew D. Wickert, Elowyn M. Yager

College of Arts and Sciences Faculty Publications

Earth's Future published by Wiley on behalf of the American Geophysical Union. In the future, Earth will be warmer, precipitation events will be more extreme, global mean sea level will rise, and many arid and semiarid regions will be drier. Human modifications of landscapes will also occur at an accelerated rate as developed areas increase in size and population density. We now have gridded global forecasts, being continually improved, of the climatic and land use changes (C&LUC) that are likely to occur in the coming decades. However, besides a few exceptions, consensus forecasts do not exist for how these C&LUC …

Climate Controls On Air Quality In The Northeastern U.S.: An Examination Of Summertime Ozone Statistics During 1993-2012, Evan M. Oswald, Lesley Ann Dupigny-Giroux, Eric M. Leibensperger, Rich Poirot, Jeff Merrell

College of Arts and Sciences Faculty Publications

The goal of this study is to better understand the linkages between the climate system and surface-level ozone concentrations in the Northeastern U.S. We focus on the regularity of observed high ozone concentrations between May 15 and August 30 during the 1993-2012 period. The first portion of this study establishes relationships between ozone and meteorological predictors. The second examines the linkages between ozone and large-scale teleconnections within the climate system. Statistical models for each station are constructed using a combination of Correlation Analysis, Principal Components Analysis and Multiple Linear Regression. In general, the strongest meteorological predictors of ozone are the …

Notes From The Field: Lessons Learned From Using Ecosystem Service Approaches To Inform Real-World Decisions, Mary Ruckelshaus, Emily Mckenzie, Heather Tallis, Anne Guerry, Gretchen Daily, Peter Kareiva, Stephen Polasky, Taylor Ricketts, Nirmal Bhagabati, Spencer A. Wood, Joanna Bernhardt

Rubenstein School of Environment and Natural Resources Faculty Publications

While there have been rapid advances in assessments of biodiversity and ecosystem services (BES), a critical remaining challenge is how to move from scientific knowledge to real-world decision making. We offer 6 lessons from our experiences applying new approaches and tools for quantifying BES in 20 pilot demonstrations: (1) Applying a BES approach is most effective in leading to policy change as part of an iterative science-policy process; (2) simple ecological production function models have been useful in a diverse set of decision contexts, across a broad range of biophysical, social, and governance systems. Key limitations of simple models arise …

Will Passive Protection Save Congo Forests?, Gillian L. Galford, Britaldo S. Soares-Filho, Laura J. Sonter, Nadine Laporte

Rubenstein School of Environment and Natural Resources Faculty Publications

Central Africa's tropical forests are among the world's largest carbon reserves. Historically, they have experienced low rates of deforestation. Pressures to clear land are increasing due to development of infrastructure and livelihoods, foreign investment in agriculture, and shifting land use management, particularly in the Democratic Republic of Congo (DRC). The DRC contains the greatest area of intact African forests. These store approximately 22 billion tons of carbon in aboveground live biomass, yet only 10% are protected. Can the status quo of passive protection - forest management that is low or nonexistent - ensure the preservation of this forest and its …

Barriers And Opportunities To Promote Rights To Sustainable Production Of Smallholders In The Context Of Climate Stresses In Central America, Raffaele Vignola

Food Systems Summit 2015

Under a systemic approach, right to food implies also considering two aspects such as the implementation of and correspondent support to sustainable agricultural production by smallholders. Given the observed and projected trends, this requires also considering how such practices can help these vulnerable producers cope with and recover from the increasing climate stresses affecting them. We here focus on these two complementary aspects for the case of coffee and basic grains smallholders: the identification of adaptive benefits of sustainable practices and the barriers and strengths of cross-scale governance to support their implementation in Central America (a highly climate-vulnerable region).

Unveiling The Species-Rank Abundance Distribution By Generalizing The Good-Turing Sample Coverage Theory, Anne Chao, T. C. Hsieh, Robin L. Chazdon, Robert K. Colwell, Nicholas J. Gotelli, B. D. Inouye

College of Arts and Sciences Faculty Publications

Based on a sample of individuals, we focus on inferring the vector of species relative abundance of an entire assemblage and propose a novel estimator of the complete species-rank abundance distribution (RAD). Nearly all previous estimators of the RAD use the conventional "plug-in" estimator pi(sample relative abundance) of the true relative abundance piof species i. Because most biodiversity samples are incomplete, the plug-in estimators are applied only to the subset of species that are detected in the sample. Using the concept of sample coverage and its generalization, we propose a new statistical framework to estimate the complete RAD by separately …

Robustness Of Spatial Micronetworks, Thomas C. Mcandrew, Christopher M. Danforth, James P. Bagrow

College of Engineering and Mathematical Sciences Faculty Publications

Power lines, roadways, pipelines, and other physical infrastructure are critical to modern society. These structures may be viewed as spatial networks where geographic distances play a role in the functionality and construction cost of links. Traditionally, studies of network robustness have primarily considered the connectedness of large, random networks. Yet for spatial infrastructure, physical distances must also play a role in network robustness. Understanding the robustness of small spatial networks is particularly important with the increasing interest in microgrids, i.e., small-area distributed power grids that are well suited to using renewable energy resources. We study the random failures of links …

Noaa Local Climate Analysis Tool (Lcat) Data, Methods, And Usability, Marina Timofeyeva-Livezey, Fiona Horsfall, Annette Hollingshead, Jenna Meyers, Lesley Ann Dupigny-Giroux

College of Arts and Sciences Faculty Publications

The National Oceanic and Atmospheric Administration (NOAA) has responded to the increased demand for local climate information by developing the Local Climate Analysis Tool (LCAT). The tool provides rapid responses to climate questions that historically required an extensive data search, research on appropriate analysis techniques, and complex graphics packages. LCAT offers easy and efficient access to scientifically sound analytical capabilities and trusted climate data. Results obtained from LCAT provide relevant climate information to local technical users, decision makers, and educators that will help build a healthy nation and create resilient communities. To ensure that LCAT responds to the articulated needs …

The Use Of Cmip5 Data To Simulate Climate Change Impacts On Flow Regime Within The Lake Champlain Basin, Ibrahim Nourein Mohammed, Arne Bomblies, Beverley C. Wemple

College of Arts and Sciences Faculty Publications

Study region: Lake Champlain Basin, northwestern New England, USA. Study focus: Our study uses regional hydrologic analyses and modeling to examine alternative possibilities that might emerge in the Lake Champlain Basin streamflow regime for various climate scenarios. Climate data as well as spatial data were processed to calibrate the Regional Hydro-Ecological Simulation System (RHESSys) model runoff simulations. The 21st century runoff simulations were obtained by driving the RHESSys model with climate data from the Coupled Model Intercomparison Project phase 5 (CMIP5) for representative concentration pathways RCP 4.5 and 8.5. New hydrological insights for the region: Our analyses suggest that most …

Mainstreaming Early Warning Systems In Development And Planning Processes: Multilevel Implementation Of Sendai Framework In Indus And Sahel, Asim Zia, Courtney Hammond Wagner

College of Agriculture and Life Sciences Faculty Publications

The third UN World Congress on Disaster Risk Reduction, held in Sendai, Japan in March 2015, agreed on a new framework to guide disaster risk reduction policy and practice for the next 15 years. The Sendai Framework for Disaster Risk Reduction 2015–2030 (SFDRR) leaves important implementation issues unspecified and potentially creates both problems and opportunities for complex, multilevel governance systems in coping with hazards and disastrous events. Early warning systems (EWS), if built into the mainstream of planning for development and disaster relief and recovery, could present a significant opportunity to realize many SFDRR goals. We explore the complexities of …

Are Conservation Organizations Configured For Effective Adaptation To Global Change?, Paul R. Armsworth, Eric R. Larson, Stephen T. Jackson, Dov F. Sax, Paul Simonin, Bernd Blossey, Nancy Green, Mary L. Klein, Liza Lester, Taylor H. Ricketts, Michael C. Runge, M. Rebecca Shaw

Rubenstein School of Environment and Natural Resources Faculty Publications

© The Ecological Society of America. Conservation organizations must adapt to respond to the ecological impacts of global change. Numerous changes to conservation actions (eg facilitated ecological transitions, managed relocations, or increased corridor development) have been recommended, but some institutional restructuring within organizations may also be needed. Here we discuss the capacity of conservation organizations to adapt to changing environmental conditions, focusing primarily on public agencies and nonprofits active in land protection and management in the US. After first reviewing how these organizations anticipate and detect impacts affecting target species and ecosystems, we then discuss whether they are sufficiently flexible …

A Framework To Assess The Health Of Rocky Reefs Linking Geomorphology, Community Assemblage, And Fish Biomass, Octavio Aburto-Oropeza, Exequiel Ezcurra, Jerry Moxley, Alexandra Sánchez-Rodríguez, Ismael Mascareñas-Osorio, Carlos Sánchez-Ortiz, Brad Erisman, Taylor Ricketts

Rubenstein School of Environment and Natural Resources Faculty Publications

The recovery of historic community assemblages on reefs is a primary objective for the management of marine ecosystems. Working under the overall hypothesis that, as fishing pressure increases, the abundance in upper trophic levels decreases followed by intermediate levels, we develop an index that characterizes the comparative health of rocky reefs. Using underwater visual transects to sample rocky reefs in the Gulf of California, Mexico, we sampled 147 reefs across 1200 km to test this reef health index (IRH). Five-indicators described 88% of the variation among the reefs along this fishing-intensity gradient: the biomass of piscivores and carnivores were positively …

Social Entrepreneurship And Social Business: Retrospective And Prospective Research, Edgard Barki, Graziella Comini, Ann Cunliffe, Stuart Hart, Sudhanshu Rai

Grossman School of Business Faculty Publications

Social Entrepreneurship and Social Business (SE/SB), inclusive business, businesses with social impact and a higher purpose are becoming increasingly important both in academia and the business world (Sassmannshausen & Volkmann, 2013). Since the influential article by Dees (1998), many different perspectives about social entrepreneurship and social business have been discussed in academia. On the management side, these types of businesses have also proliferated in the last decades. Yunus with his work leading Grameen Bank has inspired many other entrepreneurs and organizations to create a new kind of business more embedded with a social purpose. The main purpose of the Social …

Characterization Of Increased Persistence And Intensity Of Precipitation In The Northeastern United States, Justin Guilbert, Alan K. Betts, Donna M. Rizzo, Brian Beckage, Arne Bomblies

College of Engineering and Mathematical Sciences Faculty Publications

We present evidence of increasing persistence in daily precipitation in the northeastern United States that suggests that global circulation changes are affecting regional precipitation patterns. Meteorological data from 222 stations in 10 northeastern states are analyzed using Markov chain parameter estimates to demonstrate that a significant mode of precipitation variability is the persistence of precipitation events. We find that the largest region‐wide trend in wet persistence (i.e., the probability of precipitation in 1 day and given precipitation in the preceding day) occurs in June (+0.9% probability per decade over all stations). We also find that the study region is experiencing …

Acoustic Streaming, Fluid Mixing, And Particle Transport By A Gaussian Ultrasound Beam In A Cylindrical Container, Jeffrey S. Marshall, Junru Wu

College of Engineering and Mathematical Sciences Faculty Publications

A computational study is reported of the acoustic streaming flow field generated by a Gaussian ultrasound beam propagating normally toward the end wall of a cylindrical container. Particular focus is given to examining the effectiveness of the acoustic streaming flow for fluid mixing within the container, for deposition of particles in suspension onto the bottom surface, and for particle suspension from the bottom surface back into the flow field. The flow field is assumed to be axisymmetric with the ultrasound transducer oriented parallel to the cylinder axis and normal to the bottom surface of the container, which we refer to …

Pleistocene Relative Sea Levels In The Chesapeake Bay Region And Their Implications For The Next Century, Benjamin D. Dejong, Paul R. Bierman, Wayne L. Newell, Tammy M. Rittenour, Shannon A. Mahan, Greg Balco, Dylan H. Rood

College of Arts and Sciences Faculty Publications

Today, relative sea-level rise (3.4 mm/yr) is faster in the Chesapeake Bay region than any other location on the Atlantic coast of North America, and twice the global average eustatic rate (1.7 mm/yr). Dated interglacial deposits suggest that relative sea levels in the Chesapeake Bay region deviate from global trends over a range of timescales. Glacio-isostatic adjustment of the land surface from loading and unloading of continental ice is likely responsible for these deviations, but our understanding of the scale and timeframe over which isostatic response operates in this region remains incomplete because dated sea-level proxies are mostly limited to …

The Ubiquity Of Phenotypic Plasticity In Plants: A Synthesis, Kattia Palacio-López, Brian Beckage, Samuel Scheiner, Jane Molofsky

College of Agriculture and Life Sciences Faculty Publications

Ecology and Evolution Published by John Wiley & Sons Ltd. Adaptation to heterogeneous environments can occur via phenotypic plasticity, but how often this occurs is unknown. Reciprocal transplant studies provide a rich dataset to address this issue in plant populations because they allow for a determination of the prevalence of plastic versus canalized responses. From 31 reciprocal transplant studies, we quantified the frequency of five possible evolutionary patterns: (1) canalized response-no differentiation: no plasticity, the mean phenotypes of the populations are not different; (2) canalized response-population differentiation: no plasticity, the mean phenotypes of the populations are different; (3) perfect adaptive …

The Champlain Sea/Lake Champlain Transition Recorded In The Northeast Arm Of Lake Champlain, Usa-Canada, Ashliegh Theresa Belrose

Graduate College Dissertations and Theses

Sediment accumulated on a lakebed archives information about past climate and changes in the regional environment. Previous studies (Burgess, 2007; Koff, 2011; Palmer, 2012) in the Northeast Arm of Lake Champlain, specifically Missisquoi Bay and Saint Albans Bay, showed a period (~9,400 - 8,600 yBP) of elevated organic matter deposition in both bays, indicating a productive event that pre-dated any possible anthropogenic influence. However, the record was abruptly cut off and any documentation representing the span of time leading up to this event was not found. The elevated organic matter levels were explained as being the result of a warm, …

Using The Past As The Key To The Present: Informing Coastal Resource Management With Geologic Records, Benjamin D. Dejong

Graduate College Dissertations and Theses

Rising sea levels present an ongoing threat to communities and resources around the Chesapeake Bay, east coast, USA, where tide gauges indicate that the relative rise of sea level is approximately twice the rate of average, eustatic sea-level rise. This has significantly compromised the health and viability of salt marsh habitat on the Eastern Shore during the 20th century, and the biologists who are charged with managing coastal resources in the coming decades need to understand the nature and causes of high rates of regional sea-level rise to develop suitable adaptation plans.

Dated geologic deposits and geophysical models suggest that …

Using Empirical Mode Decomposition To Study Periodicity And Trends In Extreme Precipitation, Noah Pfister

Graduate College Dissertations and Theses

Classically, we look at annual maximum precipitation series from the perspective of extreme value statistics, which provides a useful statistical distribution, but does not allow much flexibility in the context of climate change. Such distributions are usually assumed to be static, or else require some assumed information about possible trends within the data. For this study, we treat the maximum rainfall series as sums of underlying signals, upon which we perform a decomposition technique, Empirical Mode Decomposition. This not only allows the study of non-linear trends in the data, but could give us some idea of the periodic forces that …