Knoxville, TN, United States

University of Tennessee at Knoxville
Knoxville, TN, United States

The University of Tennessee is a public sun-grant and land-grant university headquartered in Knoxville, Tennessee, United States. Founded in 1794, two years before Tennessee entered the Union as the 16th state, it is the flagship institution of the statewide University of Tennessee system with nine undergraduate colleges and eleven graduate colleges and hosts almost 28,000 students from all 50 states and more than 100 foreign countries. In its 2014 ranking of universities, U.S. News & World Report ranked UT 106th among all national universities and 46th among public institutions of higher learning. Seven alumni have been selected as Rhodes Scholars; James M. Buchanan, M.S. '41, received the 1986 Nobel Prize in Economics. UT's ties to nearby Oak Ridge National Laboratory, established under UT President Andrew Holt and continued under the UT-Battelle partnership, allow for considerable research opportunities for faculty and students.Also affiliated with the university are the Howard H. Baker, Jr. Center for Public Policy, the University of Tennessee Anthropological Research Facility, and the University of Tennessee Arboretum, which occupies 250 acres of nearby Oak Ridge and features hundreds of species of plants indigenous to the region. The University is a direct partner of the University of Tennessee Medical Center, which is one of two Level I trauma centers in East Tennessee. As a teaching hospital, it has aggressive medical research programs.The University of Tennessee is the only university in the nation to have three presidential papers editing projects and holds collections of the papers of all three U.S. presidents from Tennessee—Andrew Jackson, James K. Polk, and Andrew Johnson. UT is one of the oldest public universities in the United States and the oldest secular institution west of the Eastern Continental Divide. Wikipedia.

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Gavrilets S.,University of Tennessee at Knoxville
Proceedings of the National Academy of Sciences of the United States of America | Year: 2012

A crucial step in recent theories of human origins is the emergence of strong pair-bonding between males and females accompanied by a dramatic reduction in the male-to-male conflict over mating and an increased investment in offspring. How such a transition from promiscuity to pair-bonding could be achieved is puzzling. Many species would, indeed, be much better off evolutionarily if the effort spent on male competition over mating was redirected to increasing female fertility or survivorship of offspring. Males, however, are locked in a "social dilemma," where shifting one's effort from "appropriation" to "production" would give an advantage to free-riding competitors and therefore, should not happen. Here, I first consider simple models for four prominent scenarios of the human transition to pair-bonding: communal care, mate guarding, food for mating, and mate provisioning. I show that the transition is not feasible under biologically relevant conditions in any of these models. Then, I show that the transition can happen if one accounts for male heterogeneity, assortative pair formation, and evolution of female choice and faithfulness. This process is started when low-ranked males begin using an alternative strategy of female provisioning. At the end, except for the top-ranked individuals, males invest exclusively in provisioning females who have evolved very high fidelity to their mates. My results point to the crucial importance of female choice and emphasize the need for incorporating between-individual variation in theoretical and empirical studies of social dilemmas and behaviors.

Dagotto E.,University of Tennessee at Knoxville | Dagotto E.,Oak Ridge National Laboratory
Reviews of Modern Physics | Year: 2013

The iron-based superconductors that contain FeAs layers as the fundamental building block in the crystal structures have been rationalized in the past using ideas based on the Fermi surface nesting of hole and electron pockets when in the presence of weak Hubbard U interactions. This approach seemed appropriate considering the small values of the magnetic moments in the parent compounds and the clear evidence based on photoemission experiments of the required electron and hole pockets. However, recent results in the context of alkali metal iron selenides, with generic chemical composition A xFe2-ySe2 (A=alkali metal element), have challenged those previous ideas since at particular compositions y the low-temperature ground states are insulating and display antiferromagnetic order with large iron magnetic moments. Moreover, angle-resolved photoemission studies have revealed the absence of hole pockets at the Fermi level in these materials. The present status of this exciting area of research, with the potential to alter conceptually our understanding of the iron-based superconductors, is here reviewed, covering both experimental and theoretical investigations. Other recent related developments are also briefly reviewed, such as the study of selenide two-leg ladders and the discovery of superconductivity in a single layer of FeSe. The conceptual issues considered established for the alkali metal iron selenides, as well as several issues that still require further work, are discussed. © 2013 American Physical Society.

Keppens V.,University of Tennessee at Knoxville
Nature Materials | Year: 2013

Ferroelectric materials exhibit an intrinsic electric polarization that can be changed or reversed by an applied electric field. While initially ferroelectrics were little more than an academic curiosity, today they can be found at the heart of many technological devices that exploit their ferro-, piezo- and pyroelectric properties, with the most advanced application perhaps being that of ferroelectric non-volatile memories. The structure of the low-temperature ferroelectric material is always non-centrosymmetric, and therefore does not display inversion symmetry, as this prevents the charge separation inherent to the electric polarization. The compound BaTiO3 is often regarded as the prototypical ferroelectric, belonging to a family of ferroelectrics known as perovskite oxides. The low-temperature ferroelectric phase is obtained from small symmetry-breaking displacements of the Li atoms, with the loss of the inversion symmetry resulting in a spontaneous polarization at 1,483 K.

Barber B.K.,University of Tennessee at Knoxville
Journal of Child Psychology and Psychiatry and Allied Disciplines | Year: 2013

Aims and method Drawing on empirical studies and literature reviews, this paper aims to clarify and qualify the relevance of resilience to youth experiencing political conflict. It focuses on the discordance between expectations of widespread dysfunction among conflict-affected youth and a body of empirical evidence that does not confirm these expectations. Findings The expectation for widespread dysfunction appears exaggerated, relying as it does on low correlations and on presumptions of universal response to adversity. Such a position ignores cultural differences in understanding and responding to adversity, and in the specific case of political conflict, it does not account for the critical role of ideologies and meaning systems that underlie the political conflict and shape a young people's interpretation of the conflict, and their exposure, participation, and processing of experiences. With respect to empirical evidence, the findings must be viewed as tentative given the primitive nature of research designs: namely, concentration on violence exposure as the primary risk factor, at the expense of recognizing war's impact on the broader ecology of youth's lives, including disruptions to key economic, social, and political resources; priority given to psychopathology in the assessment of youth functioning, rather than holistic assessments that would include social and institutional functioning and fit with cultural and normative expectations and transitions; and heavy reliance on cross-sectional, rather than longitudinal, studies. Conclusions Researchers and practitioners interested in employing resilience as a guiding construct will face such questions: Is resilience predicated on evidence of competent functioning across the breadth of risks associated with political conflict, across most or all domains of functioning, and/or across time? In reality, youth resilience amidst political conflict is likely a complex package of better and poorer functioning that varies over time and in direct relationship to social, economic, and political opportunities. Addressing this complexity will complicate the definition of resilience, but it confronts the ambiguities and limitations of work in cross-cultural contexts. © 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.

Bose B.K.,University of Tennessee at Knoxville
IEEE Transactions on Industrial Electronics | Year: 2013

Power electronics technology has gained significant maturity after several decades of dynamic evolution of power semiconductor devices, converters, pulse width modulation (PWM) techniques, electrical machines, motor drives, advanced control, and simulation techniques. According to the estimate of the Electric Power Research Institute, roughly 70% of electrical energy in the USA now flows through power electronics, which will eventually grow to 100%. In the 21st century, we expect to see the tremendous impact of power electronics not only in global industrialization and general energy systems, but also in energy saving, renewable energy systems, and electric/hybrid vehicles. The resulting impact in mitigating climate change problems is expected to be enormous. This paper, in the beginning, will discuss the global energy scenario, climate change problems, and the methods of their mitigation. Then, it will discuss the impact of power electronics in energy saving, renewable energy systems, bulk energy storage, and electric/hybrid vehicles. Finally, it will review several example applications before coming to conclusion and future prognosis. © 1982-2012 IEEE.

O'Meara B.C.,University of Tennessee at Knoxville
Systematic Biology | Year: 2010

Species delimitation and species tree inference are difficult problems in cases of recent divergence, especially when different loci have different histories. This paper quantifies the difficulty of jointly finding the division of samples to species and estimating a species tree without constraining the possible assignments a priori. It introduces a parametric and a nonparametric method, including new heuristic search strategies, to do this delimitation and tree inference using individual gene trees as input. The new methods were evaluated using thousands of simulations and 4 empirical data sets. These analyses suggest that the new methods, especially the nonparametric one, may provide useful insights for systematists working at the species level with molecular data. However, they still often return incorrect results.

O'Meara B.C.,University of Tennessee at Knoxville
Annual Review of Ecology, Evolution, and Systematics | Year: 2012

There are many methods for making evolutionary Inferences from phylogenetic trees. Many of these can be divided into three main classes of models: continuous-time Markov chain models with finite state space (CTMC-FSS), multivariate normal models, and birth-death models. Numerous approaches are just restrictions of more general models to focus on particular questions or kinds of data. Methods can be further modified with the addition of tree-stretching algorithms. The recent realization of the effect of correlated trait evolution with diversification rates represents an important advance that is slowly revolutionizing the field. Increased attention to model adequacy may lead to future methodological improvements. © 2012 by Annual Reviews. All rights reserved.

Agency: NSF | Branch: Standard Grant | Program: | Phase: S-STEM:SCHLR SCI TECH ENG&MATH | Award Amount: 2.89M | Year: 2016

The Appalachian Students Promoting the Integration of Research in Education (ASPIRE) project will promote economic growth in the Appalachia region by supporting high achieving, low-income Appalachian students who attend the University of Tennessee in Knoxville or Chattanooga to complete degrees in science. Appalachian students come from households where post-secondary education is rare and poverty rates are high, thus creating barriers to degree completion. ASPIRE will address financial, academic, and other barriers to graduating with a scientific degree by providing scholarships and targeted academic and social support. Eighty students will receive four-year scholarships, live in research-focused living/learning communities, engage in mentored research, and participate in academic transition seminars, career-building fellowships and family activities. Scholarship students on the larger Knoxville campus will also engage with the new Appalachian Mentoring Program, which will provide support across social, academic, and career-related domains.

ASPIRE will compare students from low-income, low-minority, rural schools, which have the lowest college enrollment rate (44%) and the lowest six-year completion rates (21%) of any group, with students from low-income, high-minority, urban schools. The focus will be on evaluating the overlapping and unique needs of these two groups of students, as well as the relative effects on financial, socio-cultural and academic transition barriers on persistence and success of each type of support. Much is already known about the needs of first-generation, low-income, or underrepresented minority students; yet much less is known about the extent to which students with different combinations of these identities face different challenges and benefit from different support services. ASPIRE will provide a novel opportunity to identify and understand such unique needs. Results from this research will advance knowledge about evidence-based, high-impact practices that facilitate success for diverse students.

Agency: NSF | Branch: Standard Grant | Program: | Phase: Systems and Synthetic Biology | Award Amount: 193.13K | Year: 2017

Enzymes from thermophilic organisms are often more suitable for applications in biotechnology because they are thermostable and have optimal activities at high temperatures. This project will use novel experimental and computational approaches to define the molecular basis for these highly useful properties. Ultimately, these studies will provide important information for the selection of enzymes that are stable and optimally active at high temperatures and for the engineering of such enzymes for applications in biotechnology. This project will contribute to the training of undergraduate and graduate students and will be incorporated into outreach efforts to the public.

The elucidation of molecular principles that render proteins more stable under extreme conditions such as high temperatures has been subject of a large body of research. Earlier work suggested that thermophilic variants of enzymes have more polar interactions or more H-bonds or increased hydrophobic interactions, better packing of hydrophobic core or some combination of them. Other studies showed that some of these properties were not applicable to many other mesophilic to thermophilic comparisons and more subtle and distributed effects and dynamic properties of proteins may play a significant role in attaining thermophilicity. Sequence-based comparisons also failed to explain the basis of thermophilicity and so far no clear and unifying explanation has emerged. This project aims to determine dynamic and thermodynamic properties that separate thermophilic enzymes from their mesophilic counterparts by dissecting the effects of protein dynamics and solvent reorganization on the enzyme ligand interactions. To do this, thermophilic and mesophilic variants of the same protein (aminoglycoside-N3-nucleotidyltransferase) will be used; these variants have minimal differences in the primary sequence.

Agency: NSF | Branch: Standard Grant | Program: | Phase: Big Data Science &Engineering | Award Amount: 1.30M | Year: 2016

Open source software is an engine for innovation and a critical infrastructure for the nation and yet it is implemented by communities formed from a loose collection of individuals. With each software project relying on thousands of other software projects, this complex and dynamic supply chain introduces new risks and unpredictability, since, unlike in traditional software projects, no contractual relationships with the community exist and individuals could simply lose interest or move on to other activities.
The big data-based approach to software supply chains will stimulate academic and practical work. The tools and practices to quantify and mitigate risks in the rapidly changing global environment with no centralized control or authority will lead to dramatic reductions in risk manifested in, for example, the spread of vulnerabilities thus making the nation both safer and more innovative. The theoretical frameworks and approaches developed will likely influence research and practice in other supply chain contexts.

The objective of this research is to advance the state of knowledge of software supply chains by collecting and integrating massive public operational data representing development activity and source code from all open source projects and using it to develop novel theories, methods, and tools. The construction and analysis of the entire open source supply chain provides static and dynamic properties of the network, risk propagation, and system-level risks. Novel statistical and game-theoretic models are used to assess and mitigate these risks, while methods to contextualize, augment, and correct operational data provide ways to cope with data?s size, complexity, and observational nature.

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