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Scalings of Alfven-cyclotron and ion Bernstein instabilities on temperature anisotropy of a ring-like velocity distribution in the inner magnetosphere
Get PDFA ring-like proton velocity distribution with f(p)(v)/v>0 and which is sufficiently anisotropic can excite two distinct types of growing modes in the inner magnetosphere: ion Bernstein instabilities with multiple ion cyclotron harmonics and quasi-perpendicular propagation and an Alfven-cyclotron instability at frequencies below the proton cyclotron frequency and quasi-parallel propagation. Recent particle-in-cell simulations have demonstrated that even if the maximum linear growth rate of the latter instability is smaller than the corresponding growth of the former instability, the saturation levels of the fluctuating magnetic fields can be greater for the Alfven-cyclotron instability than for the ion Bernstein instabilities. In this study, linear dispersion theory and two-dimensional particle-in-cell simulations are used to examine scalings of the linear growth rate and saturation level of the two types of growing modes as functions of the temperature anisotropy T/T-parallel to for a general ring-like proton distribution with a fixed ring speed of 2v(A), where v(A) is the Alfven speed. For the proton distribution parameters chosen, the maximum linear theory growth rate of the Alfven-cyclotron waves is smaller than that of the fastest-growing Bernstein mode for the wide range of anisotropies (1T/T-parallel to <= 7) considered here. Yet the corresponding particle-in-cell simulations yield a higher saturation level of the fluctuating magnetic fields for the Alfven-cyclotron instability than for the Bernstein modes as long as T perpendicular to/T-parallel to greater than or similar to. Since fast magnetosonic waves with ion Bernstein instability properties observed in the magnetosphere are often not accompanied by electromagnetic ion cyclotron waves, the results of the present study indicate that the ring-like proton distributions responsible for the excitation of these fast magnetosonic waves should not be very anisotropic.Publishe
E-Learning Librarian by Night: Creating an Online Instruction Program through Self-Directed Learning
Get PDFWhen a large public university made a commitment to e-learning in its five-year strategic plan, the coordinator for the university library’s information literacy instruction program recognized the need for online instructional modules. With limited expertise among her or her colleagues, she found herself in the role of both student and teacher. This poster will illustrate multiple strategies (and dead ends) the presenter and her colleagues have pursued in an effort to integrate an effective and sustainable e-learning component into the library’s instruction program. Topics include best practices, choosing hardware and software, training, along with other relevant factors.N
Inadequate Reference Datasets Biased toward Short Non-epitopes Confound B-cell Epitope Prediction
Get PDFX-ray crystallography has shown that an antibody paratope typically binds 15-22 amino acids (aa) of an epitope, of which 2-5 randomly distributed amino acids contribute most of the binding energy. In contrast, researchers typically choose for B-cell epitope mapping short peptide antigens in antibody binding assays. Furthermore, short 6-11-aa epitopes, and in particular non-epitopes, are over-represented in published B-cell epitope datasets that are commonly used for development of B-cell epitope prediction approaches from protein antigen sequences. We hypothesized that such suboptimal length peptides result in weak antibody binding and cause false-negative results. We tested the influence of peptide antigen length on antibody binding by analyzing data on more than 900 peptides used for B-cell epitope mapping of immunodominant proteins of Chlamydia spp. We demonstrate that short 7-12-aa peptides of B-cell epitopes bind antibodies poorly; thus, epitope mapping with short peptide antigens falsely classifies many B-cell epitopes as non-epitopes. We also show in published datasets of confirmed epitopes and non-epitopes a direct correlation between length of peptide antigens and antibody binding. Elimination of short, 11-aa epitope/non-epitope sequences improved datasets for evaluation of in silico B-cell epitope prediction. Achieving up to 86% accuracy, protein disorder tendency is the best indicator of B-cell epitope regions for chlamydial and published datasets. For B-cell epitope prediction, the most effective approach is plotting disorder of protein sequences with the IUPred-L scale, followed by antibody reactivity testing of 16-30-aa peptides from peak regions. This strategy overcomes the well known inaccuracy of in silico B-cell epitope prediction from primary protein sequences.PublishedYe
Identifying Plant Part Composition of Forest Logging Residue Using Infrared Spectral Data and Linear Discriminant Analysis
Get PDFAs new markets, technologies and economies evolve in the low carbon bioeconomy, forest logging residue, a largely untapped renewable resource will play a vital role. The feedstock can however be variable depending on plant species and plant part component. This heterogeneity can influence the physical, chemical and thermochemical properties of the material, and thus the final yield and quality of products. Although it is challenging to control compositional variability of a batch of feedstock, it is feasible to monitor this heterogeneity and make the necessary changes in process parameters. Such a system will be a first step towards optimization, quality assurance and cost-effectiveness of processes in the emerging biofuel/chemical industry. The objective of this study was therefore to qualitatively classify forest logging residue made up of different plant parts using both near infrared spectroscopy (NIRS) and Fourier transform infrared spectroscopy (FTIRS) together with linear discriminant analysis (LDA). Forest logging residue harvested from several Pinus taeda (loblolly pine) plantations in Alabama, USA, were classified into three plant part components: clean wood, wood and bark and slash (i.e., limbs and foliage). Five-fold cross-validated linear discriminant functions had classification accuracies of over 96% for both NIRS and FTIRS based models. An extra factor/principal component (PC) was however needed to achieve this in FTIRS modeling. Analysis of factor loadings of both NIR and FTIR spectra showed that, the statistically different amount of cellulose in the three plant part components of logging residue contributed to their initial separation. This study demonstrated that NIR or FTIR spectroscopy coupled with PCA and LDA has the potential to be used as a high throughput tool in classifying the plant part makeup of a batch of forest logging residue feedstock. Thus, NIR/FTIR could be employed as a tool to rapidly probe/monitor the variability of forest biomass so that the appropriate online adjustments to parameters can be made in time to ensure process optimization and product quality.Ye
Understanding the growth rate patterns of ion Bernstein instabilities driven by ring-like proton velocity distributions
Get PDFFast magnetosonic waves in Earth's inner magnetosphere, which have as their source ion Bernstein instabilities, are driven by hot proton velocity distributions (f(p)) with partial derivative f(p)(v(perpendicular to))/partial derivative v(perpendicular to) > 0. Two typical types of distributions with such features are ring and shell velocity distributions. Both have been used in studies of ion Bernstein instabilities and fast magnetosonic waves, but the differences between instabilities driven by the two types of distributions have not been thoroughly addressed. The present study uses linear kinetic theory to examine and understand these differences. It is found that the growth rate pattern is primarily determined by the cyclotron resonance condition and the structure of the velocity distribution in gyroaveraged velocity space. For ring-driven Bernstein instabilities, as the parallel wave number (k(parallel to)) increases, the discrete unstable modes approximately follow the corresponding proton cyclotron harmonic frequencies while they become broader in frequency space. At sufficiently large k(parallel to), the neighboring discrete modes merge into a continuum. In contrast, for shell-driven Bernstein instabilities, the curved geometry of the shell velocity distribution in gyroaveraged velocity space results in a complex alternating pattern of growth and damping rates in frequency and wave number space and confines the unstable Bernstein modes to relatively small k(parallel to) In addition, when k(parallel to) increases, the unstable modes are no longer limited to the proton cyclotron harmonic frequencies. The local growth rate peak near an exact harmonic at small k(parallel to) bifurcates into two local peaks on both sides of the harmonic when k(parallel to) becomes large.Publishe
Predicting environmentally responsible apparel consumption behavior of future apparel industry professionals: The role of environmental apparel knowledge, environmentalism and materialism
Get PDFThe present study explored several critical constructs related to environmentally responsible apparel consumption, which include environmentalism, materialism and knowledge of environmental issues pertaining to apparel products. The research focused on apparel merchandising and design students (n = 233) as future industry professionals who will soon be driving industry decisions in apparel production and consumption. A proposed research model was subject to confirmatory factor analysis and structural equation modeling. The model explained 58% of the variance in environmentally responsible apparel consumption behavior. Environmental apparel knowledge positively influenced environmentalism, and, in turn, environmentalism had a significant positive influence on environmentally responsible apparel consumption behavior. On the contrary, environmental apparel knowledge did not significantly influence materialism, and, in turn, materialism was not related to environmentally responsible apparel consumption behavior. Practical implications and limitations of the present study are also discussed.PublishedYe
Long Embargo Periods and External Publication for Electronic Theses and Dissertations
No full textEmbargo periods for Electronic Thesis and Dissertation (ETD) collections require librarians to balance the needs of content consumers (end-users) with those of content creators (ETD authors)--consumers want access to everything, while creators want to control access to their own work. A policy statement issued by the American Historical Association (AHA) in July 2013 recommended that institutions with mandatory deposit allow creators to embargo their ETDs for a period of up to six years. The reason given for the policy was that open access might endanger publication of ETDs as monographs. It was believed that a lengthy embargo would protect graduates’ ability to publish. The ensuing discussion increased awareness of embargo among faculty and graduate students in all disciplines. This poster will examine the local impact of the AHA policy on Auburn University (AU) ETDs by examining embargo selections from academic year 2009/10 through 2015/16. It will compare embargo decisions made by PhD candidates in the history department to those made by other AU students. It will also examine the publication of monographs based on AU history dissertations. Publication rates and the length of time from ETD upload to monograph publication will be compared for unrestricted and embargoed titles to evaluate whether embargo conveys a publication advantage
Effects of elevated tropospheric ozone and fluctuating moisture supply on loblolly pine seedlings inoculated with root infecting ophiostomatoid fungi
Get PDFSouthern Pine Decline is a cause of premature mortality of Pinus species in the Southeastern United States. While the pathogenicity of ophiostomatoid fungi, associated with declining Pinus species, has been observed both in the laboratory and the field the driving mechanisms for success of fungal infection, as well as the bark-beetle vectors is less understood. The goal of this research is to provide insight into the role of future climatic conditions, specifically elevated tropospheric ozone and altered precipitation patterns, in the progression of Southern Pine Decline on loblolly pine (Pinus taeda L.). Two key questions were addressed: (1) will predicted concentrations of tropospheric ozone affect loblolly pine vigor and increase susceptibility to fungi associated with Southern Pine Decline?; and (2) will predicted precipitation patterns affect loblolly pine vigor and increase susceptibility to fungi associated with Southern Pine Decline? Our results indicate seedlings selected for susceptibility to root infecting ophiostomatoid fungi were more sensitive to elevated ozone than tolerant seedlings, however, neither ozone nor fluctuating moisture supply resulted in seedlings to becoming more susceptible to root infecting ophiostomatoid fungi
