Geomorphic History of the Atchafalaya Backwater Area: Upper Deltaic Plain Development

Earlier researchers have produced conceptual models of Mississippi River delta plain development which divide the deltaic plain into upper and lower reaches. The upper deltaic plain has been described as an area composed mainly of lacustrine, lacustrine delta, backswamp, and crevasse channels, with minimal distributary development. The lower deltaic plain is characterized by numerous distributaries forming distributary systems and lobes. Detailed geomorphic mapping and chronologic reconstruction within the Atchafalaya Backwater Area of the upper deltaic plain of the Mississippi River has led to the recognition of a complex network of distributary development related to three distinct distributary systems that formed in the upper deltaic plain over the past 2500 years. These systems do not fit previous models of upper deltaic plain development. The East Atchafalaya Basin Protection Levee blocked Atchafalaya River water and sediment from entering the study area and burying these older distributary systems, preserving their surface expression and allowing their identification. Results show that distributary systems can be a major contributor to upper deltaic plain development and that these systems are not always related to the lower delta plain delta switching process. A stable Mississippi River position and a favorable gradient in the study area over the past 4,000 years appear to be responsible for the geomorphic development of the study area

Marine Aquaculture in Maine: Understanding Diverse Perspectives and Interactions at Multiple Scales

Coastal oceans are changing and experiencing increased use. The social and ecological benefits of healthy coastal oceans are well documented and include habitats for marine species, storm protection, and recreational opportunities (MEA, 2005). As the impacts of human activities are recognized, questions about how ocean spaces should be used are becoming more common. These questions are complex and involve many tradeoffs. Understanding the values people hold about uses, and how activities and ecosystems overlap, is critical for weighing tradeoffs and improving future management. I use the northeastern U.S. state of Maine to study human interactions with coastal oceans. Maine is biologically productive and hosts commercial fishing, aquaculture, tourism, and renewable energy industries. I explore perspectives about aquaculture development at a statewide scale (Chapter 1), and intersections among scientific literature, human activities, and ecosystems in two estuaries in midcoast Maine (Chapter 2). Understanding these small-scale interactions is important for improving local management and can also provide information for larger-scale conversations. In Chapter 1, I focus on Maine’s aquaculture industry. I use the Q method to describe perspectives about aquaculture held by people who are familiar with the industry, and areas of consensus and disagreement among them. I identified four perspectives: the Aquaculture Optimists, the Aquaculture Anchors, the Aquaculture Historian, and the Aquaculture Agnostics. These groups valued Maine’s marine economy and felt aquaculture could play a role, but disagreed about the scope of the industry and the distribution of benefits. They also had different perspectives about the role of local communities in siting aquaculture farms. Understanding perspectives can contribute to dialogue about the future of the aquaculture industry in Maine and globally. In Chapter 2, I review literature about the Damariscotta River Estuary (DRE) in midcoast Maine. The DRE hosts three research institutions and is heavily studied on diverse marine science-related topics. This literature review supports a participatory mapping project using local ecological knowledge to map the spatial overlaps of shellfish and human use activities in the DRE, as well as observed changes and their causes. Preliminary results from the mapping study are in Appendix E. In the literature review, I describe the publications, their themes, locations, and the years in which they were published. I discuss missing themes and compare our literature review themes to a preliminary analysis of the participatory mapping project interview data. This identifies knowledge gaps about the estuary and highlights areas for future research. The large amount of data provides a valuable baseline for documenting change over time and shows the value of examining literature at an estuary-wide scale

Data summary and computer program for axial-flow pump rotor performance

Assembly of noncavitating blade element performance data for axial-flow pump rotor configurations has been collected and organized. Program facilitates handling large amounts of experimental data involved and may be used as data reduction program to process flow and performance measurements from other axial-flow pump configurations

Parents And Children Thriving Together: A Framework For Two-Generation Policy And System Reform

This brief explores the lessons learned from the 2016 Parents and Children Thriving Together: Two Generation State Policy Network (PACTT Network), a collaboration between the National Governors Association (NGA) and the Center for Law and Social Policy (CLASP) with funding from the Doris Duke Charitable Foundation, W.K. Kellogg Foundation and the Annie E. Casey Foundation. Through this initiative, five states explored how to use the two-generation approach to improve their state systems that serve children and parents. This brief summarizes the lessons learned from the two-year initiative and provides a framework to help guide state leaders trying to implement two-generation strategies

Gravitational instability and fragmentation of self-gravitating accretion disks

We know from observations that supermassive black holes (SMBH) of masses up to 10^{10} \msol existed in quasars when the universe was only about $10^9$ years old. The rapid formation of SMBHs can be understood as the outcome of the collision of two large gas-rich galaxies followed by disk accretion. This model relies on a large enough turbulent viscosity in the disk. We show in a linear stability analysis of thin self-gravitating viscous disks that the gravitational instability can drive a turbulence generating the $\beta$-viscosity. For simulating a self-gravitating accretion disk in polar coordinates the hydrodynamics code NIRVANA2.0 is adapted for our needs which includes cooling. The results are disk fragmentation, strong accretion at the inner radial boundary of the calculation domain and strong outflow at the outer boundary which both come about by interactions between clumps. The accretion time scale for a disk mass of 6\ex{8} \msol in a radial extent of 29 \pc to 126 \pc is about 1.2\ex{7} \yr, corresponding to a viscosity parameter $\beta \approx 0.04$. We can confirm the $\beta$-viscosity interpretation by the turbulent velocity and length scale and by the scaling of the accretion time scale. All this supports the SMBH-formation model

Age-dependent differences in human brain activity using a face- and location-matching task: An fMRI study

Purpose: To evaluate the differences of cortical activation patterns in young and elderly healthy subjects for object and spatial visual processing using a face- and location-matching task. Materials and Methods: We performed a face- and a location-matching task in 15 young (mean age: 28 +/- 9 years) and 19 elderly (mean age: 71 +/- 6 years) subjects. Each experiment consisted of 7 blocks alternating between activation and control condition. For face matching, the subjects had to indicate whether two displayed faces were identical or different. For location matching, the subjects had to press a button whenever two objects had an identical position. For control condition, we used a perception task with abstract images. Functional imaging was performed on a 1.5-tesla scanner using an EPI sequence. Results: In the face-matching task, the young subjects showed bilateral (right 1 left) activation in the occipito-temporal pathway (occipital gyrus, inferior and middle temporal gyrus). Predominantly right hemispheric activations were found in the fusiform gyrus, the right dorsolateral prefrontal cortex (inferior and middle frontal gyrus) and the superior parietal gyrus. In the elderly subjects, the activated areas in the right fronto-lateral cortex increased. An additional activated area could be found in the medial frontal gyrus (right > left). In the location-matching task, young subjects presented increased bilateral (right > left) activation in the superior parietal lobe and precuneus compared with face matching. The activations in the occipito-temporal pathway, in the right fronto-lateral cortex and the fusiform gyrus were similar to the activations found in the face-matching task. In the elderly subjects, we detected similar activation patterns compared to the young subjects with additional activations in the medial frontal gyrus. Conclusion: Activation patterns for object-based and spatial visual processing were established in the young and elderly healthy subjects. Differences between the elderly and young subjects could be evaluated, especially by using a face-matching task. Copyright (c) 2007 S. Karger AG, Basel

Hyperon Production in Proton-Nucleus Collisions at 42 GeV Center of Mass Energy

The subject of this thesis is a measurement of hyperon production ratios which is of special interest as a reference on Quark Gluon Plasma search. The data used in this analysis have been taken with a minimum bias trigger at the fixed target experiment HERA-B, which uses the 920 GeV proton beam of the HERA storage ring at DESY. $\Lambda$, $\Xi$ and $\Omega$ hyperons produced in collisions using carbon and tungsten wires as targets were reconstructed. Hyperon ratios are presented for the rapidity range $-1.5 < y < 0.5$ (where they where measured), extrapolated to the whole phase space and to $y = 0$. The main results at $y = 0$ are $\frac{\overline{\Lambda}}{\Lambda} = 0.88 \pm 0.07$ (error including systematic error) and $\frac{\overline{\Xi}}{\Xi} = 0.69 \pm 0.12$ (statistical uncertainty only) for the carbon target. These values are compared to proton--nucleus and nucleus--nucleus data above and below HERA-B energies and are comparable with both. In the rapidity range $-1.5 < y < 0.5$ the ratio $\frac{\overline{\Lambda}}{\Lambda}$ is significantly different for the two target materials, whereas extrapolated to the whole phase space it is not. A possible explanation in terms of multiple scatterings in the nucleus is given. The distribution of the $\Lambda$ particle--anti-particle asymmetry versus Feynman's scaling variable $x_f$ using the carbon target is found to be in good agreement with measurements from pion--nucleus reactions at 500 GeV $\pi$-beam energy