Non-Empirically Tuned Range-Separated DFT Accurately Predicts Both Fundamental and Excitation Gaps in DNA and RNA Nucleobases

Using a non-empirically tuned range-separated DFT approach, we study both the quasiparticle properties (HOMO-LUMO fundamental gaps) and excitation energies of DNA and RNA nucleobases (adenine, thymine, cytosine, guanine, and uracil). Our calculations demonstrate that a physically-motivated, first-principles tuned DFT approach accurately reproduces results from both experimental benchmarks and more computationally intensive techniques such as many-body GW theory. Furthermore, in the same set of nucleobases, we show that the non-empirical range-separated procedure also leads to significantly improved results for excitation energies compared to conventional DFT methods. The present results emphasize the importance of a non-empirically tuned range-separation approach for accurately predicting both fundamental and excitation gaps in DNA and RNA nucleobases.Comment: Accepted by the Journal of Chemical Theory and Computatio

Ehealth Security Australia: The Solution Lies with Frameworks and Standards

Security is a key foundation for eHealth in Australia, driving benefits in healthcare quality, safety, and efficiency towards improved health outcomes for all Australians. To this end, the National eHealth Transition Authority (NEHTA), the Royal Australian College of General Practitioners (RACGP), and Standards Australia have each produced security-related publications to assist Australian healthcare organisations protect their data. These publications provide standards, tools, and guides for the healthcare industry to build and implement secure systems that protect patient data and eHealth-related assets, while providing the provenance required to help ensure patient safety and privacy. This paper outlines some of the current and emerging threats and risks to eHealth in Australia, and how these Australian security-based standards and frameworks can assist in mitigating such threats, support the management of information security risks, and maintain legislative compliance

Effects of Chemical Variation on Competition and Insect Communities Across Solidago altissima Genotypes

Individuals within a plant species can differ greatly from one another, especially regarding the range of chemical compounds produced. However, the functions of many of these chemicals are unknown, but likely include defenses against herbivores, attractants for pollinators and seed dispersers, as well as mechanisms for resource competition. To assess the effects of foliar chemical composition on interspecific plant competition and insect communities, I conducted a common garden and greenhouse experiment using 24 genotypes of the allelopathic species Solidago altissima for which the foliar chemistry had been characterized. Using these data and chemical profiles of S. altissima, I linked foliar chemistry to plant performance, competitive ability and the foliar/floral insect communities. The common garden experiment showed there was great variation in foliar chemistry between the genotypes. Ecological patterns existed between foliar chemistry and plant performance, as foliar chemistry was strongly related to most measures of plant performance across genotypes. Pollinator communities were found to relate with total aboveground biomass, proportion of flower mass, and % light transmittance as well as plant chemistry. The greenhouse experiment showed marked variation in both rhizome and above-ground biomass growth for S. altissima. The above-ground biomass of Abutilon theophrasti, S. scoparium, and S. integrifolium had their biomass significantly reduced via competition with S. altissima. Chemistry significantly affected the biomass of both A. theophrasti and S. scoparium, suggesting that chemistry is a critical driver of competition for S. altissima

GRASSLAND DIVERSITY AND PRODUCTIVITY: THE INTERPLAY OF RESOURCE AVAILABILITY AND PROPAGULE POOLS

Processes operating at multiple spatial scales govern the structure and functioning of ecological communities. We conducted a resource manipulation and propagule addition experiment in grassland to evaluate the interaction of local resource availability and propagule pools in governing local-scale plant colonization, biodiversity, and above-ground productivity. The availabilities of establishment microsites and water were manipulated in field plots for two years through the application of experimental soil disturbances and irrigation, respectively. Resource manipulations led to increased invasibility of the community, as predicted by the theory of fluctuating resources. Rates of colonization,enhanced by the sowing of 32 grassland species, increased plant diversity and above ground productivity, but to a greater extent under conditions of resource enrichment. Although resource enrichment generally increased diversity and productivity, these responses were contingent upon species availability and tended to be more pronounced in the presence of an expanded propagule pool. These findings suggest that biodiversity at the level of the available propagule pool and fluctuations in resources interact to regulate local resident diversity and productivity by determining opportunities for species sorting, by mediating community assembly, and by governing the potential for functional compensation in the community

Grassland diversity and productivity: the interplay of resource availability and propagule pools

Processes operating at multiple spatial scales govern the structure and functioning of ecological communities. We conducted a resource manipulation and propagule addition experiment in grassland to evaluate the interaction of local resource availability and propagule pools in governing local-scale plant colonization, biodiversity, and aboveground productivity. The availabilities of establishment microsites and water were manipulated in field plots for two years through the application of experimental soil disturbances and irrigation, respectively. Resource manipulations led to increased invasibility of the community, as predicted by the theory of fluctuating resources. Rates of colonization, enhanced by the sowing of 32 grassland species, increased plant diversity and aboveground productivity, but to a greater extent under conditions of resource enrichment. Although resource enrichment generally increased diversity and productivity, these responses were contingent upon species availability and tended to be more pronounced in the presence of an expanded propagule pool. These findings suggest that biodiversity at the level of the available propagule pool and fluctuations in resources interact to regulate local resident diversity and productivity by determining opportunities for species sorting, by mediating community assembly, and by governing the potential for functional compensation in the community

Green Forestry? Case Studies of Sustainable Forestry and Forest Certification

Abstract This dissertation explored sustainable forest management from multiple perspectives: a literature-based investigation to define management practices that sustain ecological, economic, and social forest resources over time; a field-based research project to identify management practice differences between Forest Stewardship Council (FSC) certified, Sustainable Forestry Initiative (SFI) certified, and uncertified properties in Maine; and a field-based research project to identify stand structural differences between FSC certified and uncertified properties in Vermont. Based on an extensive literature review, we developed an iterative decision-making framework of goal-setting/implementation/ monitoring/review that could assist forest owners in choosing management practices to sustain ecological, economic, and/or social capital over multiple time frames. Our unique contribution is the identification of six concrete management concepts at the implementation phase: (1) BMPs/RIL, (2) biodiversity conservation, (3) community forestry, (4) forest protection, (5) sustained forest product yield, and (6) triad forestry. Forest owners can implement practices under one or more of these concepts to achieve their sustainability goals. We illustrate a hypothetical application of our framework with a case study of an FSC certified managed natural forest in the lowland tropical region of Costa Rica. In the white pine forests of south-central Maine, we compared three FSC, SFI, and uncertified private properties against local scale Montreal criteria using triangulation of evidence from management documents, staff interviews, and field inspections. Certified properties were associated with improved internal management systems and improved practices for biodiversity conservation. However, our data suggest that certification does not necessarily involve fulfillment of all Montreal criteria, such as adherence to sustained timber yield, consideration of multiple social issues, or ecological monitoring at multiple temporal and spatial scales. In northern hardwood stands in central Vermont, we compared three FSC certified and three uncertified that were analogous in terms harvesting date, silvicultural treatment type, forest type, and general location. The uncertified sites were randomly selected to remove bias. We conducted stand structural analysis of both live trees and standing and downed coarse woody debris, and also developed 10-year growth projections using FVS/NE-TWIGS. Our data suggest that FSC certified stands had similar timber economic value, similar live tree structure, and similar tree carbon storage, but significantly greater residual coarse woody debris than comparable uncertified harvested stands

Patch size effects on plant species decline in an experimentally fragmented landscape

This is the publisher's version, also available electronically from http://www.esa.org/esa.Understanding local and global extinction is a fundamental objective of both basic and applied ecology. Island biogeography theory (IBT) and succession theory provide frameworks for understanding extinction in changing landscapes. We explore the relative contribution of fragment size vs. succession on species' declines by examining distributions of abundances for 18 plant species declining over time in an experimentally fragmented landscape in northeast Kansas, USA. If patch size effects dominate, early-successional species should persist longer on large patches, but if successional processes dominate, the reverse should hold, because in our system woody plant colonization is accelerated on large patches. To compare the patterns in abundance among patch sizes, we characterize joint shifts in local abundance and occupancy with a new metric: rank occupancy–abundance profiles (ROAPs). As succession progressed, statistically significant patch size effects emerged for 11 of 18 species. More early-successional species persisted longer on large patches, despite the fact that woody encroachment (succession) progressed faster in these patches. Clonal perennial species persisted longer on large patches compared to small patches. All species that persisted longer on small patches were annuals that recruit from the seed bank each year. The degree to which species declined in occupancy vs. abundance varied dramatically among species: some species declined first in occupancy, others remained widespread or even expanded their distribution, even as they declined in local abundance. Consequently, species exhibited various types of rarity as succession progressed. Understanding the effect of fragmentation on extinction trajectories requires a species-by-species approach encompassing both occupancy and local abundance. We propose that ROAPs provide a useful tool for comparing the distribution of local abundances among landscape types, years, and species