The Rain Forests of Home: an Atlas of People and Place

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Seismic stratigraphy of the Ontong Java Plateau

The Ontong Java Plateau, a large, deep-water carbonate plateau in the western equatorial Pacific, is an ideal location for studying responses of carbonate sedimentation to the effects of changing paleoceanographic conditions. These carbonate responses are often reflected in the physical properties of the sediment, which in turn control the appearance of seismic reflection profiles. Seismic stratigraphy analyses, correlating eight reflector horizons to each drill site, have been conducted in an attempt to map stratigraphic data. Accurate correlation of seismic stratigraphic data to drilling results requires conversion of traveltime to depth in meters. Synthetic seismogram models, using shipboard physical properties data, have been generated in an attempt to provide this correlation. Physical properties, including laboratory-measured and well-log data, were collected from sites drilled during Deep Sea Drilling Project Legs 30 and 89, and Ocean Drilling Program Leg 130, on the top and flank of the Ontong Java Plateau. Laboratory-measured density is corrected to in-situ conditions by accounting for porosity rebound resulting from removal of the sediment from its overburden. The correction of laboratory-measured compressional velocity to in situ appears to be largely a function of increases in elastic moduli (especially shear rigidity) with depth of burial, more than a function of changes in temperature, pressure, or density (porosity rebound). Well-log velocity and density data for the ooze intervals were found to be greatly affected by drilling disturbance; hence, they were disregarded and replaced by lab data for these intervals. Velocity and density data were used to produce synthetic seismograms. Correlation of seismic reflection data with synthetic data, and hence with depth below seafloor, at each drill site shows that a single velocity-depth function exists for sediments on the top and flank of the Ontong Java Plateau. A polynomial fit of this function provides an equation for domain conversion: Depth (mbsf) = 44.49 + 0.800(traveltime[ms]) + 3.308 × 10 4 (traveltime[ms]2 ) Traveltime (ms) = -35.18 + 1.118(depth[mbsf]) - 1.969 × KT* (depth[mbsf]2 ) Seismic reflection profiles down the flank of the plateau undergo three significant changes: (1) a drastic thinning of the sediment column with depth, (2) changes in the echo-character of the profile (development of seismic facies), and (3) loss of continuous, coherent reflections. Sediments on the plateau top were largely deposited by pelagic processes, with little significant postdepositional or syndepositional modification. Sediments on the flank of the plateau are also pelagic, but they have been modified by faulting, erosion, and mass movement. These processes result in disrupted and incoherent reflectors, development of seismic facies, and redistribution of sediment on the flank of the plateau. Seismic stratigraphic analyses have shown that the sediment section decreases in thickness by as much as 65% between water depths of 2000 m water depth (at the top of the plateau) and 4000 m (near the base of the plateau). Thinning is attributed to increasing carbonate dissolution with depth. If this assumption is correct, then changes in the relative thicknesses of seismostratigraphic units at each drill site are indicative of changes in the position of the lysocline and the dissolution gradient between the lysocline and the carbonate compensation depth. We think that a shallow lysocline in the early Miocene caused sediment thinning. A deepening of the lysocline in the late-early Miocene caused relative thickening at each site. Within the middle Miocene, a sharp rise in lysoclinal depth occurs, concurrent with a steepening of the dissolution gradient. These events result in sediment thinning at all four sites. The thicker sections in the late Miocene likely correspond to a deepening of the lysocline, and a subsequent rise in the lysocline again hinders accumulation of sediment in the very late Miocene and Pliocene

A Topological Deep Learning Framework for Neural Spike Decoding

The brain's spatial orientation system uses different neuron ensembles to aid in environment-based navigation. One of the ways brains encode spatial information is through grid cells, layers of decked neurons that overlay to provide environment-based navigation. These neurons fire in ensembles where several neurons fire at once to activate a single grid. We want to capture this firing structure and use it to decode grid cell data. Understanding, representing, and decoding these neural structures require models that encompass higher order connectivity than traditional graph-based models may provide. To that end, in this work, we develop a topological deep learning framework for neural spike train decoding. Our framework combines unsupervised simplicial complex discovery with the power of deep learning via a new architecture we develop herein called a simplicial convolutional recurrent neural network (SCRNN). Simplicial complexes, topological spaces that use not only vertices and edges but also higher-dimensional objects, naturally generalize graphs and capture more than just pairwise relationships. Additionally, this approach does not require prior knowledge of the neural activity beyond spike counts, which removes the need for similarity measurements. The effectiveness and versatility of the SCRNN is demonstrated on head direction data to test its performance and then applied to grid cell datasets with the task to automatically predict trajectories

Interferometry

The following recommended programs are reviewed: (1) infrared and optical interferometry (a ground-based and space programs); (2) compensation for the atmosphere with adaptive optics (a program for development and implementation of adaptive optics); and (3) gravitational waves (high frequency gravitational wave sources (LIGO), low frequency gravitational wave sources (LAGOS), a gravitational wave observatory program, laser gravitational wave observatory in space, and technology development during the 1990's). Prospects for international collaboration and related issues are also discussed

Net Farm Income Impacts of Alternative Risk Management Bills

The impacts of the bills are measured against the FAPRI January 1999 baseline which may be found at http://hdl.handle.net/10355/3318At the request of Senator Richard Lugar, Chairman of the Committee on Agriculture, Nutrition and Forestry, FAPRI has analyzed impacts of two alternative risk management proposals. The first proposal is the Farmers' Risk Management Act of 1999, sponsored by Senator Lugar (IN) and co-sponsored by Senators McConnell (KY), Fitzgerald (IL), and Helms (NC). The second proposal is the Risk Management for the 21st Century Act, put forth by Senator Roberts (KS) and co-sponsored by Senator Kerrey (NE) and others

Analysis of Risk Management Proposals

An earlier analysis which concentrated on the aggregate net farm income and government outlay impacts may be found at http://hdl.handle.net/10355/3318At the request of several members of the Committee on Agriculture, Nutrition, and Forestry of the Senate, FAPRI has continued to analyze the impacts of two alternative risk management proposals. The proposals are the Farmers' Risk Management Act of 1999 (S. 1666) and the Risk Management for the 21st Century Act (S. 1580)

Stakeholder Theory and Marketing: Moving from a Firm-Centric to a Societal Perspective

This essay is inspired by the ideas and research examined in the special section on “Stakeholder Marketing” of the Journal of Public Policy & Marketing in 2010. The authors argue that stakeholder marketing is slowly coalescing with the broader thinking that has occurred in the stakeholder management and ethics literature streams during the past quarter century. However, the predominant view of stakeholders that many marketers advocate is still primarily pragmatic and company centric. The position advanced herein is that stronger forms of stakeholder marketing that reflect more normative, macro/societal, and network-focused orientations are necessary. The authors briefly explain and justify these characteristics in the context of the growing “prosociety” and “proenvironment” perspectives—orientations that are also in keeping with the public policy focus of this journal. Under the “hard form” of stakeholder theory, which the authors endorse, marketing managers must realize that serving stakeholders sometimes requires sacrificing maximum profits to mitigate outcomes that would inflict major damage on other stakeholders, especially society