3,505 research outputs found

    Fish assemblages and indicator species: reef fishes off the southeastern United States

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    For many fish stocks, resource management cannot be based on stock assessment because data are insufficient-a situation that requires alternative approaches to management. One possible approach is to manage data-limited stocks as part of an assemblage and to determine the status of the entire unit by a data-rich indicator species. The utility of this approach was evaluated in analyses of 15 years of commercial and 34 years of recreational logbook data from reef fisheries off the southeastern United States coast. Multivariate statistical analyses successfully revealed three primary assemblages. Within assemblages, however, there was little evidence of synchrony in population dynamics of member species, and thus, no support for the use of indicator species. Nonetheless, assemblages could prove useful as management units. Their identification offers opportunities for implementing management to address such ecological considerations as bycatch and species interrelations

    Extraterrestrial applications of solar optics for interior illumination

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    Solar optics is a terrestrial technology that has potential extraterrestrial applications. Active solar optics (ASO) and passive solar optics (PSO) are two approaches to the transmission of sunlight to remote interior spaces. Active solar optics is most appropriate for task illumination, while PSO is most appropriate for general illumination. Research into solar optics, motivated by energy conservation, has produced lightweight and low-cost materials, products that have applications to NASA's Controlled Ecological Life Support System (CELSS) program and its lunar base studies. Specifically, prism light guides have great potential in these contexts. Several applications of solar optics to lunar base concepts are illustrated

    The Mystery of the Incarnation: Towards a Reconciliation of Cyril and Nestorius

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    This thesis studies the fifth-century christological controversy surrounding Cyril of Alexandria (c. 378-444) and Nestorius of Constantinople (c. 381-451) and their debate around the person and nature of Jesus Christ, sparked by the theotokos dispute. At the First Council of Ephesus (431) the christologies of these two bishops and theologians were pitted against each other, and have since been studied in contrast to one another. The goal of this study is to examine the christologies of Cyril and Nestorius with the intention to seek reconciliation between the two. In the Introduction I first orient the reader to the problem and issues at stake, then examine issues of source material used, and finally I define the sources which formulated the christologies of Cyril and Nestorius. Chapter One begins the effort to determine the roots each theologian’s christology by examining the hermeneutical, soteriological, and philosophical underpinnings of their respective “schools” of Alexandria and Antioch. In Chapter Two I carefully develop the core christology of Cyril and Nestorius, highlighting their major features and points of contention. In Chapter Three I begin the move towards reconciling the two diverging christologies by noting the strengths and weaknesses of each, as well as points of agreement, finally setting each as the “edges” of an orthodox description of the Incarnation. In the Conclusion I summarize my thesis statement, while noting areas to improve this study and needs of further contribution to the field of Cyrilline and Nestorian studies

    Energy and Charge Transfer in Organic Materials and Its Spectroscopic Signature: An Ab Initio Approach

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    Energy and charge transfer processes in organic materials have received a tremendous amount of attention in recent years, due to their impact on functionality within a wide range of applications. One prominent example is the field of organic photovoltaics (OPVs), where significant improvements in power conversion efficiency and durability have been achieved over the last decade. Another example is organic scintillators, which have seen a renewed interest due to the constrained supply of helium–3 gas, as well as their ability to discriminate between types of ionizing radiation. Advancement in the design of organic photovoltaic and luminescent materials can be facilitated by molecular level insights into the processes of energy transfer, gained through both experimental observations and theoretical and computational modeling. Thus, this thesis utilizes computational techniques to investigate excited states, and their spectroscopic signatures, in molecular systems that are experimentally relevant for OPVs and organic scintillators. In Chapter II of this thesis, a computational protocol based on density functional theory (DFT) is presented for calculating the dependence of the vibrational frequency of a carbonyl reporter mode on the electronic state of the molecular system, in the context of charge transfer (CT) in organic molecules. This protocol was utilized to study a system consisting of a phenyl–C61–butyric acid methyl ester electron acceptor with a N,N–dimethylaniline donor, in which small frequency shifts of less than 4 cm−1 were observed between the ground state and the CT excited state. A Stark tuning rate of 0.768 cm−1/(MV/cm) was calculated between the vibrational frequency and the electric field. In Chapter III of this thesis, the CT process in a carotenoid–porphyrin–C60 molecular triad was investigated in its two primary conformations (bent/linear) with an explicit tetrahydrofuran solvent via molecular dynamics. Vibrational frequency distributions were calculated for the amide I mode and found to be sensitive to the three electronic states relevant to CT: the Pi–Pi* excited state, the porphyrin-to-C60 CT state, and the carotenoid-to-C60 charge-separated state, with shifts as large as 40–60 cm−1 observed between the CT1 and CT2 states. Rate constants between these states were calculated with a hierarchy of approximations based on the linearized semiclassical method. The CT process was determined to occur via a two-step mechanism, Pi–Pi* -> CT1 -> CT2, where the second step is mediated by the bent-to-linear conformation change. In Chapter IV of this thesis, the role of intersystem crossing (ISC) from S1 to Tn in the pulse-shape discrimination (PSD) ability of single-crystal trans–stilbene was investigated. Time-dependent DFT was used with the newly developed OT– SRSH–PCM method to calculate the excited states, and an equilibrium Fermi’s golden rule approach was employed to calculate transition rate constants. The ISC rates were found to be too slow to compete with prompt fluorescence, and thus do not significantly impact the PSD ability. Deuteration of trans–stilbene was found to have a retarding effect on the ISC rates, with rate constants reduced by as much as 30%. Finally, in Chapter V of this thesis, a novel compute-to-learn pedagogy is presented, in which students design and develop interactive demonstrations of physical chemistry concepts in a peer-led studio environment. The rationale behind the pedagogy and improvements made over the course of three iterations are discussed, as well as an initial assessment of the pedagogy conducted via end-of-semester interviews.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/147569/1/klwill_1.pd

    A probability-based approach to setting annual catch levels.

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    The requirement of setting annual catch limits to prevent overfishing has been added to the Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 (MSRA). Because this requirement is new, a body of applied scientific practice for deriving annual catch limits and accompanying targets does not yet exist. This article demonstrates an approach to setting levels of catch that is intended to keep the probability of future overfishing at a preset low level. The proposed framework is based on stochastic projection with uncertainty in population dynamics. The framework extends common projection methodology by including uncertainty in the limit reference point and in management implementation, and by making explicit the risk of overfishing that managers consider acceptable. The approach is illustrated with application to gag (Mycteroperca microlepis), a grouper that inhabits the waters off the southeastern United States. Although devised to satisfy new legislation of the MSRA, the framework has potential application to any fishery where the management goal is to limit the risk of overfishing by controlling catch

    Becoming a Co-Conspirator: Strategies for Anti-Racism through Human Rights Education

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    This paper seeks to provide introductory knowledge and strategies for individuals who are new to the academic study of race, and to serve as a charge to move beyond simple allyship to become effective co-conspirators in the fight against racism. This is achieved through a literature review of race, anti-racism, human rights education, and then a concluding section detailing how to integrate human rights education into co-conspiratorship. Ultimately, this paper contends that human rights education provides the necessary academic background and the practical framework to help individuals move beyond performative allyship towards co-conspiratorship

    Real-Time Stochastic Predictive Control for Hybrid Vehicle Energy Management.

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    This work presents three computational methods for real time energy management in a hybrid hydraulic vehicle (HHV) when driver behavior and vehicle route are not known in advance. These methods, implemented in a receding horizon control (aka model predictive control) framework, are rather general and can be applied to systems with nonlinear dynamics subject to a Markov disturbance. State and input constraints are considered in each method. A mechanism based on the steady state distribution of the underlying Markov chain is developed for planning beyond a finite horizon in the HHV energy management problem. Road elevation information is forecasted along the horizon and then merged with the statistical model of driver behavior to increase accuracy of the horizon optimization. The characteristics of each strategy are compared and the benefit of learning driver behavior is analyzed through simulation on three drive cycles, including one real world drive cycle. A simulation is designed to explicitly demonstrate the benefit of adapting the Markov chain to real time driver behavior. Experimental results demonstrate the real time potential of the primary algorithm when implemented on a processor with limited computational resources

    Rock against Reagan : The punk movement, cultural hegemony, and Reaganism in the eighties

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    Despite scholars’ growing interest in the cultural movement known as punk, there has been a lack of focus on the movement’s relationship to its historical context. Punk meant rebellion, and this research looks at how the rebellion of the American punk movement during the eighties [1978 to 1992], was aimed at the president Ronald Reagan. Their dissent, however, was not only directed towards Reagan, but the culture that he encompassed. Under this influence, American culture gave way to Reaganism: a culture of individualism, greed, power, and symbols. Adding to the work by historian Dewar MacLeod and others who have focused on punk rock in major urban settings like New York and Los Angeles, this project will look beyond those centers. By using fanzines (underground magazine publications), songs, oral histories, interviews, video recordings, and popular news media sources, this research explores: the influence of the Atlantic littoral in the development and politics of punk; a regional focus on the Midwest and how the youth of the region created a punk community in an unlikely location; the “Rock Against Reagan” tour and political activism within punk that challenged Reagan’s bid for a second presidential term; censorship and the charges of “distributing harmful matter to a minor” against the Dead Kennedys’ 1985 Frankenchrist album; and how the punk movement adapted to a new decade, and what can be seen as a new century in the 1990s. Filling a missing gap for research, this project helps to better understand the punk movement, Reagan, and the culture of the eighties

    Rock Against Reagan: Punk Rock, Politics, and the 1984 Presidential Election

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    Punk Rock was more than just a style of music, but instead a cultural and political movement. During the 1984 Presidential Election punks from across the U.S. gathered at Rock Against Reagan concerts to demonstrate their opposition to not just the president but also the ideology of the New Right
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