An Examination of Beta Diversity Indices and Their Predictors in Two Large-scale Systems

Biodiversity is what conservation biology was developed to conserve. It is the physical manifestation of life as a concept and, be it for practical or idealistic reasons, all conservationists seek to protect or, in some cases, enhance it. Because of its monolithic importance to the field, much effort has been expended trying to better measure and understand it. Recently, greater attention has been paid to the partition of diversity; the observation that the total diversity of a system (γ) can be broken down into within-site diversity (α) and between-site diversity (β). In particular, it has been noticed that the β component of diversity is not as well studied or understood as the α component. In this study I attempt to address this shortfall, by examining two questions: (1) how is β is best measured and (2) what drives β? To answer the first question, I look to find the measure of β that is most robust to sampling error. While many β indices have been proposed, few have considered how our methods of data gathering might affect those indices. Datasets collected from the real world will all likely have some sort of error within them as a result of the way they were sampled. Those errors will affect some indices more than others, and the indices that are least affected will be the most reliable for actual data. Once robust indices were identified, I used them to identify possible predictors of β in two large, national datasets. The first dataset was the National Lakes Assessment created by the USEPA, in which diatoms were sampled from over 1000 lakes across the country. The second was the eBird dataset from the Cornell Lab of Ornithology, which used citizen science to generate a continuous dataset spanning both the last decade and the boundaries of the conterminous United States. β calculated from these sources was regressed against relevant environmental variables to create a clearer understanding of the effects of the environment on the β of two very different ecological systems

The Significance of the Ancient Standing Stones, Villages, Tombs on Orkney Island

The Orkney Islands make up an archipelago north of Scotland. A collection of ancient stone structures believed to predate the pyramids of Egypt and the golden age of China is found in this remote corner of the globe. Archaeological evidence from these islands is consistent in several ways with the biblical account in Genesis 11:1-9 that describes an advanced civilization at Babel in Mesopotamia, the confusion of languages, and the dispersion of groups of people throughout the world. Descendants of these dispersed people very likely built the advanced Orcadian civilization that prospered over 4000 years ago

Steklov Eigenvalue Problems on Nearly Spherical and Annular Domains

We consider Steklov eigenvalues on nearly spherical and nearly annular domains in d dimensions where d is any given positive integer. By using the Green-Beltrami identity for spherical harmonic functions, the derivatives of Steklov eigenvalues with respect to the domain perturbation parameter can be determined by the eigenvalues of a matrix involving the integral of the product of three spherical harmonic functions. By using the addition theorem for spherical harmonic functions, we determine conditions when the trace of this matrix becomes zero. These conditions can then be used to determine when spherical and annular regions are critical points while we optimize Steklov eigenvalues subject to a volume constraint. In addition, we develop numerical approaches based on particular solutions and show that numerical results in two and three dimensions are in agreement with our analytic results

On reference solutions and the sensitivity of the 2D Kelvin-Helmholtz instability problem

Two-dimensional Kelvin-Helmholtz instability problems are popular examples for assessing discretizations for incompressible flows at high Reynolds number. Unfortunately, the results in the literature differ considerably. This paper presents computational studies of a Kelvin-Helmholtz instability problem with high order divergence-free finite element methods. Reference results in several quantities of interest are obtained for three different Reynolds numbers up to the beginning of the final vortex pairing. A mesh-independent prediction of the final pairing is not achieved due to the sensitivity of the considered problem with respect to small perturbations. A theoretical explanation of this sensitivity to small perturbations is provided based on the theory of self-organization of 2D turbulence. Possible sources of perturbations that arise in almost any numerical simulation are discussed.Comment: 24 pages, 12 figures, 2 table

Brief Studies

Critique of the Revised Standard Version of the Epistle of St. James Renaissance or Reformatio

A novel Arabidopsis pathosystem reveals cooperation of multiple hormonal response-pathways in host resistance against the global crop destroyer Macrophomina phaseolina.

Dubbed as a "global destroyer of crops", the soil-borne fungus Macrophomina phaseolina (Mp) infects more than 500 plant species including many economically important cash crops. Host defenses against infection by this pathogen are poorly understood. We established interactions between Mp and Arabidopsis thaliana (Arabidopsis) as a model system to quantitatively assess host factors affecting the outcome of Mp infections. Using agar plate-based infection assays with different Arabidopsis genotypes, we found signaling mechanisms dependent on the plant hormones ethylene, jasmonic acid and salicylic acid to control host defense against this pathogen. By profiling host transcripts in Mp-infected roots of the wild-type Arabidopsis accession Col-0 and ein2/jar1, an ethylene/jasmonic acid-signaling deficient mutant that exhibits enhanced susceptibility to this pathogen, we identified hundreds of genes potentially contributing to a diverse array of defense responses, which seem coordinated by complex interplay between multiple hormonal response-pathways. Our results establish Mp/Arabidopsis interactions as a useful model pathosystem, allowing for application of the vast genomics-related resources of this versatile model plant to the systematic investigation of previously understudied host defenses against a major crop plant pathogen

Evaluation of Salmon (<i>Salmo salar</i>) and Rainbow Trout (<i>Oncorhynchus mykiss</i>) pin bones using textural analysis and micro X-ray computational tomography

Industrially, common problems arise with the deboning pin bone process, where Atlantic Salmon (Salmo salar) and Rainbow Trout (Oncorhynchus mykiss) fillets, post rigor, are subjected to a pulling process to remove the pin bones from the fillet. This study measured the length of pin bones from two species of fish and two different industrial graded weights, and then used a texture analyser and lCT X-ray to measure the pulling force, break point and volume of the pin bones of both species of fish. Results showed that salmon pin bones required significantly higher pulling force to remove pin bones from the fish fillet when compared with Trout pin bones. Interestingly Trout pin bones were significantly longer and stronger than Salmon pin bones, but had significantly lower volume. This research has progressed the issues surrounding pin boning industrially, however, more studies are required in order to understand if these differences affect the overall deboning pin bone process

The effect of collagenase, water and calcium chloride on the removal of <i>Salmo salar</i> (salmon) and <i>Oncorhynchus mykiss</i> (trout) pin bones

The aim of this study was to determine the influence of the fillet structure on the deboning force required to remove salmon and trout pin bones. Salmon and trout fillets with differing fillet structure were used, in order to study the importance of the fillet structure on the deboning process. In the first test naturally gaping and non-gaping fillets were compared. To confirm the role that the collagen plays within the fillet structure, the fillets underwent series of treatments. Fillets were put into (i) a collagenase solution to remove the collagen in the fillet (ii) a calcium chloride solution to determine if collagen was the main influential factor. Both treated salmon and trout fillets were again compared to untreated fillets from the same batch. The results indicate that collagenase and calcium chloride have a large interaction on deboning force compared to water or no treatments