Letter to Philander Chase

Stow expresses thankfulness for Chase\u27s friendship and writes a poem about the spirituality of nature set in the park of Greenwich.https://digital.kenyon.edu/chase_letters/1616/thumbnail.jp

Phase Transitions in Relativistic Systems

The BCS free energy for 3P2 paired neutron matter is derived taking account of relativistic effects. It is found that the values taken by the Ginzburg-Landau parameters are always in the region of the phase diagram correponding to a unitary phase. Phase transitions in the early universe are also discussed with inclusion of the effects of Higgs scalar chemical potentials as well as fermionic chemical potentials. The conditions for equilibrium, and the critical density to prevent symmetry restoration at high temperatures are studied. It is observed that the decay of pre-existing Higgs scalar asymmetries could greatly reduce baryon number and lepton number to entropy ratios from their initial values. Phase transitions in supersymmetric theories and the phenomenom of symmetry anti-restoration in a supersymmetric model with a U(1) gauge symmetry are studied at finite density.<p

Firm size diversity, functional richness, and resilience

This paper applies recent advances in ecology to our understanding of firm development, sustainability, and economic development. The ecological literature indicates that the greater the functional richness of species in a system, the greater its resilience – that is, its ability to persist in the face of substantial changes in the environment. This paper focuses on the effects of functional richness across firm size on the ability of industries to survive in the face of economic change. Our results indicate that industries with a richness of industrial functions are more resilient to employment volatility

Assessing the stratigraphic variations in geomechanical properties of the United Kingdom Bowland Shale using wireline and seismic data : how could these guide the placement of lateral wells?

This work forms part of a study addressing the multi-scale heterogeneous and anisotropic rock properties of the Lower Carboniferous (Mississippian) Bowland Shale; the UK’s most prospective shale-gas play. The specific focus of this work is to determine the geomechanical variability within the Preese Hall exploration well and, following a consideration of structural features in the basin, to consider the optimal position of productive zones for hydraulic fracturing. Positioning long-reach horizontal wells is key to the economic extraction of gas, but their placement requires an accurate understanding of the local geology, stress regime and structure. This is of importance in the case of the Bowland Shale because of several syn- and post-depositional tectonic events that have resulted in multi-scale and anisotropic variations in rock properties. Seismic, well and core data from the UK’s first dedicated shale-gas exploration programme in northwest England have all been utilized for this study. Our workflow involves; (1) summarizing the structural elements of the Bowland Basin and framing the challenges these may pose to shale-gas drilling; (2) making mineralogical and textural-based observations using cores and wireline logs to generate mineralogy logs and then to calculate a mineral-based brittleness index along the well; (3) developing a geomechanical model using slowness logs to determine the breakdown stress along the well; (4) placing horizontal wells guided by the mineral-based brittleness index and breakdown stress. Our interpretations demonstrate that the study area is affected by the buried extension of the Ribblesdale Fold Belt that causes structural complexity that may restrict whether long-reaching horizontal wells can be confidently drilled. However, given the thickness of the Bowland Shale, a strategy of production by multiple, stacked lateral wells has been proposed. The mineralogical and geomechanical modelling presented herein suggests that several sites retain favorable properties for hydraulic fracturing. Two landing zones within the Upper Bowland Shale alone are suggested based on this work, but further investigation is required to assess the impact of small-scale elastic property variations in the shale to assess potential for well interference and optimizing well placement

Pharmacokinetics of the SABRE agent 4,6-d2-Nicotinamide and also Nicotinamide in rats following oral and intravenous administration

To prepare the way for using the isotopically labelled SABRE hyperpolarised 4,6-d2-nicotinamide as an MRI agent in humans we have performed an in-vivo study to measure its pharmacokinetics in the plasma of healthy rats after intravenous and oral administration. Male Han Wistar rats were dosed with either 4,6-d2-nicotinamide or the corresponding control, non-labelled nicotinamide, and plasma samples were obtained at eight time points for up to 24 hours after administration. Pharmacokinetic parameters were determined from agent concentration-versus-time data for both 4,6-d2-nicotinamide and nicotinamide. 4,6-d2-nicotinamide proved to be well tolerated regardless of route of administration at the concentrations used (20, 80 and 120 mg/kg). Pharmacokinetic parameters were similar after oral and intravenous administration and similar to those obtained for nicotinamide. Analysis of nicotinamide plasma concentrations after dosing 4,6-d2-nicotinamide intravenously demonstrates a reversible exchange of endogenous nicotinamide by this labelled agent over the time-course of our assays. Supported by a large body of evidence for the safety of nicotinamide when dosed orally in humans, we conclude that 4,6-d2-nicotinamide can also be safely administered intravenously, which will provide significant benefit when using this agent for planned imaging studies in humans

Macrosystems ecology: Understanding ecological patterns and processes at continental scales

Macrosystems ecology is the study of diverse ecological phenomena at the scale of regions to continents and their interactions with phenomena at other scales. This emerging subdiscipline addresses ecological questions and environmental problems at these broad scales. Here, we describe this new field, show how it relates to modern ecological study, and highlight opportunities that stem from taking a macrosystems perspective. We present a hierarchical framework for investigating macrosystems at any level of ecological organization and in relation to broader and finer scales. Building on well-established theory and concepts from other subdisciplines of ecology, we identify feedbacks, linkages among distant regions, and interactions that cross scales of space and time as the most likely sources of unexpected and novel behaviors in macrosystems. We present three examples that highlight the importance of this multiscaled systems perspective for understanding the ecology of regions to continents

Effect of sedimentary heterogeneities in the sealing formation on predictive analysis of geological CO₂ storage

Numerical models of geologic carbon sequestration (GCS) in saline aquifers use multiphase fluid flow-characteristic curves (relative permeability and capillary pressure) to represent the interactions of the non-wetting CO2 and the wetting brine. Relative permeability data for many sedimentary formations is very scarce, resulting in the utilisation of mathematical correlations to generate the fluid flow characteristics in these formations. The flow models are essential for the prediction of CO2 storage capacity and trapping mechanisms in the geological media. The observation of pressure dissipation across the storage and sealing formations is relevant for storage capacity and geomechanical analysis during CO2 injection. This paper evaluates the relevance of representing relative permeability variations in the sealing formation when modelling geological CO2 sequestration processes. Here we concentrate on gradational changes in the lower part of the caprock, particularly how they affect pressure evolution within the entire sealing formation when duly represented by relative permeability functions. The results demonstrate the importance of accounting for pore size variations in the mathematical model adopted to generate the characteristic curves for GCS analysis. Gradational changes at the base of the caprock influence the magnitude of pressure that propagates vertically into the caprock from the aquifer, especially at the critical zone (i.e. the region overlying the CO2 plume accumulating at the reservoir-seal interface). A higher degree of overpressure and CO2 storage capacity was observed at the base of caprocks that showed gradation. These results illustrate the need to obtain reliable relative permeability functions for GCS, beyond just permeability and porosity data. The study provides a formative principle for geomechanical simulations that study the possibility of pressure-induced caprock failure during CO2 sequestration

Detecting spatial regimes in ecosystems

Research on early warning indicators has generally focused on assessing temporal transitions with limited application of these methods to detecting spatial regimes. Traditional spatial boundary detection procedures that result in ecoregion maps are typically based on ecological potential (i.e. potential vegetation), and often fail to account for ongoing changes due to stressors such as land use change and climate change and their effects on plant and animal communities. We use Fisher information, an information theory-based method, on both terrestrial and aquatic animal data (U.S. Breeding Bird Survey and marine zooplankton) to identify ecological boundaries, and compare our results to traditional early warning indicators, conventional ecoregion maps and multivariate analyses such as nMDS and cluster analysis. We successfully detected spatial regimes and transitions in both terrestrial and aquatic systems using Fisher information. Furthermore, Fisher information provided explicit spatial information about community change that is absent from other multivariate approaches. Our results suggest that defining spatial regimes based on animal communities may better reflect ecological reality than do traditional ecoregion maps, especially in our current era of rapid and unpredictable ecological change

LETTERS TO THE EDITOR

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65729/1/j.1752-7325.1980.tb01869.x.pd