The influence of traits on species responses to climate change: Does warming negatively impact native species more than invasive species?

Current climate change is increasing global temperatures so that many organisms are now experiencing temperatures outside of their thermal tolerance, which threatens their survival. Organisms respond to physiologically stressful temperatures to reduce this threat. Organisms respond to warming through three main mechanisms: range shifts, adjustments via phenotypic plasticity, and evolutionary adaptation. Organisms vary in their ability to utilize these three mechanisms, leading to differences in the magnitude and success of their adjustments to temperature change. Here, I examine how organismal traits influence variation in species response to climate change. Chapter one addresses how physiological tolerance may influence the rate of range shifts across elevation using a meta-analysis of twenty published data sets. Next, in chapter two, I address how invasive versus native species may respond differently to climate change because of predictable differences in traits, specifically phenotypic plasticity. Since plasticity often plays an important role in invasion success, invasive species may have higher plasticity than their native cogeners. Therefore, climate change may be more detrimental to native species than invasive ones, exacerbating the negative effects of invasive species on native biodiversity. To address this possibility, I examine differences in plasticity between an introduced and a native Onthophagus dung beetle species living in the Southeastern United States. In Chapter three, I investigate native dung beetle communities of the Great Smoky Mountain National Park to better understand possible impacts of introduced beetles. Then, I address variation in physiological plasticity (chapter four) and behavioral plasticity (chapter five) between the native species, O. hecate, and the introduced species, O. taurus. Taken together, these studies indicate that species traits, including physiological tolerance, acclimation ability, and reproductive behavior influence species responses to warming. The introduced beetle, O. taurus, is more capable of withstanding warming than the native O. hecate due to differences in these traits, indicating that climate change may increase the impacts of O. taurus on native dung beetle communities

Sorption and chemical transformation of PAHs on coal fly ash

The objective of this research is to characterize the interactions of coal fly ash with polycyclic aromatic hydrocarbons (PAHs) and their derivatives, and to understand the influence of the surface properties of coal ash (and other atmospheric particles) on the chemical transformations of polycyclic aromatic compounds. During the past year the following specific aspects of this broad problem area have been investigated: (a) Fractionation of heterogeneous coal fly ash samples into different particle types varying in size and chemical composition (carbonaceous, mineral-magnetic, and mineral nonmagnetic); (b) The use of gas-solid chromatography to measure heats of sorption of PAHS, and PAH derivatives, on coal fly ashes and ash fractions. (c) Identification of the major photoproduct(s) of the photodecomposition of one PAH (benz[a]anthracene) sorbed on model adsorbents; (d) Estimation of fractal dimensions'' of coal fly ash particles by use of specific surface area measurements, with an ultimate objective of using these measurements to assess the importance of inner-filter effects'' on the photodecomposition of PAHs sorbed on fly ash particles. (e) The photochemical transformation of a representative nitro-PAH derivative (1-nitropyrene) sorbed on fly ash. (f) Development of techniques for studying the nonphotochemical reactions of hydroxyl radicals (and other atmospheric constituents) with PAHs sorbed on fly ash. Progress achieved, and problems encountered, in each of these major areas of emphasis is described below

Chemical interactions of polycyclic organic compounds with coal fly ash and related solid surfaces

The interactions of polycyclic aromatic hydrocarbons (PAHs) with particulate surfaces (especially those of coal fly ash) have been investigated, and the influence of coal ash surface properties on the photochemical transformation of adsorbed PAHs has been studied. The overall objective of the work has been to characterize the effects of adsorption onto atmospheric particulate matter on the chemical behavior of PAHs released into the atmosphere via combustion processes. Progress is reported in the following areas of effort: (a) Major emphasis has been devoted to the interactions of PAHs with the different particulate phases that are found in heterogeneous coal ash samples. Techniques have been developed and thoroughly characterized for the fractionation of coal ashes into carbonaceous, mineral-magnetic, and mineral-nonmagnetic subfractions. Heats of adsorption for pyrene on such subfractions have been measured by gas-solid chromatography, and the photoreactivity of pyrene and benz[a]anthracene on ash subfractions has been examined. Carbonaceous particles exhibit the highest affinity for vapor-phase PAHS; mineral magnetic particles usually exhibit the smallest tendency to sorb PAHs from the vapor phase. Adsorption of PAHs on carbonaceous particles suppresses, virtually completely, their tendency to undergo photochemical transformation. For coal ashes that contain few carbonaceous particles, the adsorption and photochemical transformation of PAHs tend to be dominated by the mineral nonmagnetic particles; PAHs adsorbed on these particles tend to exhibit relatively efficient phototransformation

Ionic liquids at electrified interfaces

Until recently, “room-temperature” (<100–150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)–(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of “first-generation” room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the “later generation” RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in “cocktails” of one’s choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost “universal” solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) “sister-systems”.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules

How Trusting Should We Be of Trust Measurements?

Psychology has come under fire in recent years as researchers struggle to replicate previously published findings (Open Science Collaboration, 2015). One reason studies may fail to replicate is differences in definitions of constructs of methods of measurement (Flake & Fried, 2020). This paper assesses how the construct of trust and related constructs have been defined and operationalized in the literature. At least seven trust-related constructs have been established within the literature. However, the definitions of these constructs are quite inconsistent, leading to confusion within the trust literature. Few of the measures that have been commonly used to measure trust-related constructs have been thoroughly validated. As a result, it is difficult to evaluate psychological theory surrounding trust. This paper identifies and analyzes inconsistencies surrounding how trust-related constructs are named, defined, and measured within the literature. It also assesses the existing evidence for construct validity of these measures and proposes future work that could potentially help establish clarity and consistency within the trust literature