Controlling wave propagation through nonlinear engineered granular systems

We study the fundamental dynamic behavior of a special class of ordered granular systems in order to design new, structured materials with unique physical properties. The dynamic properties of granular systems are dictated by the nonlinear, Hertzian, potential in compression and zero tensile strength resulting from the discrete material structure. Engineering the underlying particle arrangement of granular systems allows for unique dynamic properties, not observed in natural, disordered granular media. While extensive studies on 1D granular crystals have suggested their usefulness for a variety of engineering applications, considerably less attention has been given to higher-dimensional systems. The extension of these studies in higher dimensions could enable the discovery of richer physical phenomena not possible in 1D, such as spatial redirection and anisotropic energy trapping. We present experiments, numerical simulation (based on a discrete particle model), and in some cases theoretical predictions for several engineered granular systems, studying the effects of particle arrangement on the highly nonlinear transient wave propagation to develop means for controlling the wave propagation pathways. The first component of this thesis studies the stress wave propagation resulting from a localized impulsive loading for three different 2D particle lattice structures: square, centered square, and hexagonal granular crystals. By varying the lattice structure, we observe a wide range of properties for the propagating stress waves: quasi-1D solitary wave propagation, fully 2D wave propagation with tunable wave front shapes, and 2D pulsed wave propagation. Additionally the effects of weak disorder, inevitably present in real granular systems, are investigated. The second half of this thesis studies the solitary wave propagation through 2D and 3D ordered networks of granular chains, reducing the effective density compared to granular crystals by selectively placing wave guiding chains to control the acoustic wave transmission. The rapid wave front amplitude decay exhibited by these granular networks makes them highly attractive for impact mitigation applications. The agreement between experiments, numerical simulations, and applicable theoretical predictions validates the wave guiding capabilities of these engineered granular crystals and networks and opens a wide range of possibilities for the realization of increasingly complex granular material design.

Variations in eastern North Pacific demersal fish biomass based on the U.S. west coast groundfish bottom trawl survey (2003–2010)

In response to declining biomass of Northeast Pacific groundfish in the late 1990s and to improve the scientific basis for management of the fishery, the Northwest Fisheries Science Center standardized and enhanced their annual bottom trawl survey in 2003. The survey was expanded to include the entire area along the U.S. west coast at depths of 55–1280 m. Coast-wide biomass and species richness significantly decreased during the first eight years (2003–10) of this fishery-independent survey. We observed an overall tendency toward declining biomass for 62 dominant taxa combined (fishery target and nontarget species) and four of seven subgroups (including cartilaginous fish, flatfishes, shelf rockfishes, and other shelf species), despite increasing or variable biomass trends in individual species. These decreases occurred during a period of reduced catch for groundfish along the shelf and upper slope regions relative to historical rates. We used information from multiple stock assessments to aggregate species into three groups: 1) with strong recruitment, 2) without strong recruitment in 1999, and 3) with unknown recruitment level. For each group, we evaluated whether declining biomass was primarily related to depletion (using year as a proxy) or environmental factors (i.e., variation in the Pacific Decadal Oscillation). According to Akaike’s information criterion, changes in aggregate biomass for species with strong recruitment were more closely related to year, whereas those with no strong recruitment were more closely related to climate. The significant decline in biomass for species without strong recruitment confirms that factors other than depletion of the exceptional 1999 year class may be responsible for the observed decrease in biomass along the U.S. west coast.

Evaluation of bioelectrical impedance analysis and Fulton’s condition factor as nonlethal techniques for estimating short-term responses in postsmolt Atlantic salmon (Salmo salar) to food availabili

We evaluated measures of bioelectrical impedance analysis (BIA) and Fulton’s condition factor (K) as potential nonlethal indices for detecting short-term changes in nutritional condition of postsmolt Atlantic salmon (Salmo salar). Fish reared in the laboratory for 27 days were fed, fasted, or fasted and then refed. Growth rates and proximate body composition (protein, fat, water) were measured in each fish to evaluate nutritional status and condition. Growth rates of fish responded rapidly to the absence or reintroduction of food, whereas body composition (% wet weight) remained relatively stable owing to isometric growth in fed fish and little loss of body constituents in fasted fish, resulting in nonsignificant differences in body composition among feeding treatments. The utility of BIA and Fulton’s K as condition indices requires differences in body composition. In our study, BIA measures were not significantly different among the three feeding treatments, and only on the final day of sampling was K of fasted vs. fed fish significantly different. BIA measures were correlated with body composition content; however, wet weight was a better predictor of body composition on both a content and concentration (% wet weight) basis. Because fish were growing isometrically, neither BIA nor K was well correlated with growth rate. For immature fish, where growth rate, rather than energy reserves, is a more important indicator of fish condition, a nonlethal index that reflects shortterm changes in growth rate or the potential for growth would be more suitable as a condition index than either BIA measures or Fulton�

The autobiographical project of Soveida Dosamantes in Face of an angel, by Denise Chávez

O objetivo desta dissertação é investigar o viés coletivo da autobiografia ficcional de Face of an angel, da escritora estadunidense e de origem mexicana Denise Chávez. Desse modo, o trabalho pretende discutir a sociedade chicana descrita sob a ótica da narradora/protagonista, Soveida Dosamantes, investigando desde o processo histórico de que é resultado, passando pela iniquidade entre os papéis desempenhados por homens e mulheres até chegar ao discurso autorreferencial com que a narradora/protagonista representa o ambiente cultural em que se insere. Antes da narrativa propriamente dita, há a árvore genealógica da narradora/protagonista, assinalando que o que vai se descortinar ao longo da leitura é uma saga de família. Assim, Soveida Dosamantes utiliza a sua ambiência doméstica, bem como a comunidade da fictícia cidade de Água Oscura, sua cidade natal, como recorte de uma estrutura social maior. Fazendo uso do discurso autobiográfico, a narradora/protagonista criada por Denise Chávez expõe as mazelas de uma comunidade que, em virtude ser produto do colonialismo e do neocolonialismo, perdeu sua identidade cultural. Em Face of an angel, através do relato em primeira pessoa de sua narradora/protagonista, a autora Denise Chávez reproduz o universo em que nasceu e cresceu. Cedendo a Soveida Dosamantes componentes autobiográficos como complicadas relações familiares, personagens femininas nativas que funcionam como sentinelas de práticas ancestrais que o domínio europeu apagou, personagens masculinos que mascaram sua fragilidade por trás de uma força e de um poder aparentes, Chávez representa em Face of an Angel o microcosmos de uma comunidade que vem, aos poucos, subvertendo o discurso oficial e conquistando o seu terreno no panorama político e social estadunidense

Forensic Fisheries Science: Literature Review and Research Suggestions

Recent years have seen a dramatic increase in litigation against the National Marine Fisheries Service, NOAA. Litigation may affect personnel throughout the agency, including scientists, whose work is often directly or indirectly influenced by complex legal requirements, but who may not be in a position to comment or engage in public dialogue. It may be helpful for scientists and other agency personnel to join the ongoing discussion in the legal community regarding the interface of science and law. This paper provides a starting point with a selected introduction to relevant legal literature in this area. It uses the phrase “forensic fisheries science” to describe the application of science to legal requirements in the fishery management context. It concludes with suggestions for future research that could assist NMFS scientists as they grapple with the challenge of using science to help the agency meet its complex legal requirements. Forensic: belonging to, used in, or suitable to courts of judicature or to public discussion and debate; argumentative, rhetorical; relating to or dealing with the application of scientific knowledge to legal problems (Merriam-Webster Online Dictionary )

Nest site selection by Black-necked Crane Grus nigricollis in the Ruoergai Wetland, China

From 5 May 2003 to early June 2005, nest site selection of Black-necked Cranes Grits nigricollis was studied at the Ruoergai Wetland Nature Reserve (RWNR), an important breeding area for the species in China. Results showed that the crane nests only in we

Manipulation of host density affects infestation of a peritrich ciliate (Epistylis lacustris) on a calanoid copepod (Leptodiaptomus minutus) in Crystal Lake, Wisconsin, USA

Specimens of the calanoid copepod, Leptodiaptomus minutus, collected in June 1994 in oligotrophic: north temperate Crystal Lake, were infested with the stalked ciliate Epistylis lacustris. E. lacustris was highly specific to L. minutus and no other coexisting zooplankters were infested. Excluding nauplii, nearly 70% of copepods carried 1-20 ciliates, although the maximum load was as high as 250 ciliates. A lower percentage of nauplii were infested by the ciliate; those that were infested had a lower ciliate load than other copepod stages. Infestation by ciliates had no significant influence on the average egg number of female copepods. In a field experiment, higher copepod densities in enclosures resulted in a significantly higher infestation rate, but the ciliate load per individual copepod did not differ significantly among treatments.

Visual Navigation: Constructing and Utilizing Simple Maps of an Indoor Environment

The goal of this work is to navigate through an office environmentsusing only visual information gathered from four cameras placed onboard a mobile robot. The method is insensitive to physical changes within the room it is inspecting, such as moving objects. Forward and rotational motion vision are used to find doors and rooms, and these can be used to build topological maps. The map is built without the use of odometry or trajectory integration. The long term goal of the project described here is for the robot to build simple maps of its environment and to localize itself within this framework.

Saying isn't necessarily believing: influencing self-theories in computing

Simon, B., Hanks, B., Murphy, L., Fitzgerald, S., McCauley, R., Thomas, L., and Zander, C. 2008. Saying isn't necessarily believing: influencing self-theories in computing. In Proceeding of the Fourth international Workshop on Computing Education Research (Sydney, Australia, September 06 - 07, 2008). ICER '08. ACM, New York, NY, 173-184.

Debugging: the good, the bad, and the quirky -- a qualitative analysis of novices' strategies

Murphy, L., Lewandowski, G., McCauley, R., Simon, B., Thomas, L., and Zander, C. 2008. Debugging: the good, the bad, and the quirky -- a qualitative analysis of novices' strategies. SIGCSE Bull. 40, 1 (Feb. 2008), 163-167

A Characterization of First-Order Definable Subsets on Classes of Finite Total Orders

We give an explicit and easy-to-verify characterization for subsets in finite total orders (infinitely many of them in general) to be uniformly definable by a first-order formula. From this characterization we derive immediately that Beth's definability theorem does not hold in any class of finite total orders, as well as that McColm's first conjecture is true for all classes of finite total orders. Another consequence is a natural 0-1 law for definable subsets on finite total orders expressed as a statement about the possible densities of first-order definable subsets.

Genomic and Functional Variation at a Normal Human Centromere

Centromeres are chromosomal loci essential for genome stability. Their malfunction can cause chromosome instability associated with cancer, infertility, and birth defects. This study focused on an intriguing centromere on human chromosome 17, which displays normal functional variation. Centromere identity can be found on either of two large arrays of repetitive DNA. We investigated inter-individual sequence variation on these two arrays and found association between array size, array variation, and centromere function. Our data suggest a functional influence of DNA sequence at this critical epigenetic locus.

Site Report for Phase III Archaeological Investigations at Reynolds Tavern (18AP23), 4 Church Circle, Annapolis, Maryland. 1982-1984

This report details the archaeology completed at Reynolds Tavern in the years 1982,1983, and 1984. It was completed in 2013, nearly 30 years after the excavation took place, using archival materials such as the draft interim reports, unit summary forms, original notes and photographs which are currently stored in the University Archives at Hornbake Library, at the University of Maryland, College Park. This report has been a collaboration across time and space, drawing from preliminary reports written by Anne Yenstch and Susan Mira in 1982 and Joe Dent and Beth Ford in 1983, as well as original notes from students of the field schools held there during those years, various analyses by scholars from many universities (including the University of Maryland, University of Georgia, and the College of William and Mary), and historical research by Nancy Baker. Thomas Cuddy began the writing of this report in 2002, completing the first three chapters in addition to the artifact analysis that led to the postexcavation identification of the African bundles in the Reynolds Tavern basement. This remarkable discovery was made along with Mark Leone of the University of Maryland, founder and director of Archaeology in Annapolis, who also served as the Principle Investigator during all three years of the Reynolds Tavern excavations. Dr. Leone contributed the fifth and final chapter to this report, the Conclusions and Recommendations, during its final compilation in 2013. The final report, including the fourth chapter on the archaeology itself, was written in part and compiled by Patricia Markert of the University of Maryland in the spring of 2013. Reynolds Tavern has been part of the landscape of Annapolis for two-hundred and fifty five years (at the time of the publication of this report). It sits on Church Circle facing St. Anne’s Church, and is a beautiful example of 18th century Georgian architecture as well one of the defining features of Historic Annapolis today. It currently operates as a popular restaurant and pub, but has served variously as a hat shop, a tavern, an inn, a library and a bank over time, among other things. Its long history contributes to its significance as an archaeological site, and also as a historic marker in present day Annapolis. The archaeology conducted at Reynolds Tavern shed light on life in 18th and 19th century Annapolis, illuminating details of the occupants’ lives through the material traces they left behind. These include an 18th century cobblestone road that ran diagonally through the Tavern’s yard, telling of the movement through early Annapolis; a large and intact well, which was found ii to contain a 19 foot wooden pipe; a large, ovular privy containing many of the objects used on a day to day basis at the Tavern or the structures around it; a subterranean brick storage feature in the basement of the Tavern, which may have been used by Reynolds during his days operating a hat shop; and also in the basement, two African caches of objects, providing a glimpse into West African spiritual practices alive in historic Annapolis and the presence of African American individuals at the Tavern in the 18th and 19th centuries. The purpose of this report is to detail these archaeological investigations and their findings, so that a public record will be available and the archaeology completed at Reynolds Tavern can continue to contribute to the history of Annapolis.

Aplicación de modelos semióticos al análisis de poesía narrativa popular ecuatoriana difundida en audiovisuales

Se expone una fundamentación teórica, lógica y metodológica de tres modelos semióticos: los elementos y funciones de la comunicación de Jakobson; el modelo actancial de Greimas; y los mundos: real, referencia y posible de Eco, aplicados al análisis de poesía narrativa popular difundida en distintos formatos audiovisuales.

Islands of pain in a sea of change: Behaviour analysis and bereavement,

The paper Bereavement: A behavioural process (Dillenburger & Keenan, 1994) was first published within a vacuum of behaviour analytic thinking or research in this field. The paper was meant to be a first step in stimulating others to contribute to the understanding of one of the most complex, yet most universal, human behavioural processes. The only behaviour analyst addressing the issues directly was Calkin (1990). Recently, after reading our original 1994 paper, Beth Sulzer-Azaroff suggested that we should solicit comments directly from the behaviour analytic community. This we did with the help of Erik Arntzen and now the reprint and the commentaries in this edition of the European Journal of Behaviour Analysis (EJBA) fully embrace and extend the contribution of behaviour analysis to the understanding of the behavioural process that is bereavement.