IMPACTS OF RECREATIONAL AVIATION ON WILDLIFE: THE PHYSIOLOGICAL STRESS RESPONSE IN WHITE-TAILED DEER (Odocoileus virginianus) AND ASSOCIATED USER PERCEPTIONS

Recreational aviation on public lands may negatively impact wildlife. However, land-use decisions need to balance user need with wildlife impact. We know very little about 1) how back country airstrip use affects local wildlife, or 2) attitudes and perceptions of recreational pilots toward possible management actions. For my Master’s research, I investigated how aircraft activity influenced physiological measures of stress in white-tailed deer, while also modeling how psychometrics such as wildlife attitudes and place attachment predict the willingness of recreational pilots engage in impact-mitigating behaviors. I measured physiological stress through non-invasive sampling of stress hormones in fecal samples (fecal glucocorticoid metabolites: FGM). My results suggest that neither air traffic rates nor amount of human presence at recreation sites explained variation in FGM; however, much of the variation in deer FGM can be explained by abiotic factors such as wind velocity and precipitation. A quantitative survey of recreational pilots revealed that more positive attitudes toward wildlife were associated with greater support for impact-mitigating behaviors, while stronger place attachment to airstrips resulted in more negative attitudes toward these behaviors. Viewing recreation areas as socio-ecological systems calls for a multi-disciplinary approach, and employing biological and social science to study anthropogenic impacts on wildlife is the conceptual basis for integrative wildlife planning. By investigating organismal responses of wildlife to recreational aviation and attitudes of this user group, my aim was to provide an initial look into the impacts of recreational aviation within the framework of integrative wildlife planning

Picoheterotroph (Bacteria and Archaea) biomass distribution in the global ocean

We compiled a database of 39 766 data points consisting of flow cytometric and microscopical measurements of picoheterotroph abundance, including both Bacteria and Archaea. After gridding with 1° spacing, the database covers 1.3% of the ocean surface. There are data covering all ocean basins and depths except the Southern Hemisphere below 350m or from April until June. The average picoheterotroph biomass is 3.9 ± 3.6 µg Cl-1 with a 20-fold decrease between the surface and the deep sea. We estimate a total ocean inventory of about 1.3 × 1029 picoheterotroph cells. Surprisingly, the abundance in the coastal regions is the same as at the same depths in the open ocean. Using an average of published open ocean measurements for the conversion from abundance to carbon biomass of 9.1 fg cell-1, we calculate a picoheterotroph carbon inventory of about 1.2 Pg C. The main source of uncertainty in this inventory is the conversion factor from abundance to biomass. Picoheterotroph biomass is ? 2 times higher in the tropics than in the polar oceans

Labyrinthic granular landscapes

We have numerically studied a model of granular landscape eroded by wind. We show the appearance of labyrinthic patterns when the wind orientation turns by $90^\circ$. The occurence of such structures are discussed. Morever, we introduce the density $n_k$ of ``defects'' as the dynamic parameter governing the landscape evolution. A power law behavior of $n_k$ is found as a function of time. In the case of wind variations, the exponent (drastically) shifts from 2 to 1. The presence of two asymptotic values of $n_k$ implies the irreversibility of the labyrinthic formation process.Comment: 3 pages, 3 figure, RevTe

FACTORS AFFECTING THE PROFITABILITY OF GOLF COURSES IN GEORGIA

Land Economics/Use,

Opinion disparity in hypergraphs with community structure

The division of a social group into subgroups with opposing opinions, which we refer to as opinion disparity, is a prevalent phenomenon in society. This phenomenon has been modeled by including mechanisms such as opinion homophily, bounded confidence interactions, and social reinforcement mechanisms. In this paper we study a complementary mechanism for the formation of opinion disparity based on higher-order interactions, i.e., simultaneous interactions between multiple agents. We present an extension of the planted partition model for uniform hypergraphs as a simple model of community structure and consider the hypergraph SIS model on a hypergraph with two communities where the binary ideology can spread via links (pairwise interactions) and triangles (three-way interactions). We approximate this contagion process with a mean-field model and find that for strong enough community structure, the two communities can hold very different average opinions. We determine the regimes of structural and infectious parameters for which this opinion disparity can exist and find that the existence of these disparities is much more sensitive to the triangle community structure than to the link community structure. We show that the existence and type of opinion disparities are extremely sensitive to differences in the sizes of the two communities.Comment: 14 pages, 8 figure

Far‐infrared spectroscopy of CO 2 clathrate hydrate with Martian applications

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95481/1/grl7965.pd

Increased complexity of vasopressin's vascular actions

Vasopressin is becoming a widely used pressor in conditions with severe hypotension. Like several other hormones important in cardiovascular and extracellular fluid control, however, vasopressin can activate several receptors that when pharmacologically or pathologically stimulated may result in conflicting effects. In the present issue of Critical Care, Rehberg and colleagues examined the hypothesis that blockade of vasopressin V2 receptor during septic shock may be beneficial. Their tantalizing results indicate that future work must consider the precise vasopressin receptors that are stimulated and/or inhibited