Ecology of Ticks (Acari: Ixodidae) in Shelterbelts of Southeastern Nebraska

Shelterbelts in the agricultural landscape provide valuable habitat to a variety of animals that in turn may be hosts to ixodid ticks. The purpose of this study is to determine if shelterbelt associated factors influence tick ecology. In 2010 and 2011, ticks were collected from several shelterbelts in southeast Nebraska in Lancaster and Saunders counties. Four tick species were identified. Adjacent land use, shelterbelt composition, and time of day were all factors which did not influence the number of questing ticks collected. Differences in relation to aspect and distance from the shelterbelt were significant. The east side had continually higher numbers of questing ticks than the north, south and west. The duration of tick activity was reduced on the north side. Solar radiation, soil moisture and soil temperature could influence tick emergence from diapause resulting in the first cohort of the year. Based on my findings, the entomological risk for land management can be augmented, tick control strategies can become more effective and less wasteful, and knowledge of the presence of the various species of ticks can impact policies on public health and education. Advisor: Manuel Roberto Cortina

Land Use, Landscapes, and Biological Invasions

The negative effect of invasive species on native species, communities, and ecosystems is widely recognized, and the economic effects in the United States are estimated to be billions of dollars annually. Studies often examine traits of nonnative species or examine what makes a particular habitat invasible. To better understand the factors governing invasions, we used the flora of Nebraska to characterize and compare native and nonnative plant occurrences throughout the state. In addition, we assessed four critical landscape predictors of nonnative plant richness: human population size and three land cover attributes that included percentage of grassland, percentage of agriculture, and percentage of public lands. Results indicated that individual plant species richness has increased by about 35% through invasions (primarily of annuals from the family Poaceae). In addition, human population density, percentage of agriculture, and percentage of public lands all show a positive association with nonnative plant richness. Successful plant invasions may change the composition of species communities, basic ecological functions, and the delivery of ecosystem services. Thus, identifying the factors that influence such variation in distribution patterns can be fundamental to recognizing the present and potential future extent of nonnative plant infestations and, in turn, developing appropriate management programs

Pterosaur melanosomes support signalling functions for early feathers

Remarkably well-preserved soft tissues in Mesozoic fossils have yielded substantial insights into the evolution of feathers(1). New evidence of branched feathers in pterosaurs suggests that feathers originated in the avemetatarsalian ancestor of pterosaurs and dinosaurs in the Early Triassic(2), but the homology of these pterosaur structures with feathers is controversial(3,4). Reports of pterosaur feathers with homogeneous ovoid melanosome geometries(2,5) suggest that they exhibited limited variation in colour, supporting hypotheses that early feathers functioned primarily in thermoregulation(6). Here we report the presence of diverse melanosome geometries in the skin and simple and branched feathers of a tapejarid pterosaur from the Early Cretaceous found in Brazil. The melanosomes form distinct populations in different feather types and the skin, a feature previously known only in theropod dinosaurs, including birds. These tissue-specific melanosome geometries in pterosaurs indicate that manipulation of feather colour-and thus functions of feathers in visual communication-has deep evolutionary origins. These features show that genetic regulation of melanosome chemistry and shape(7-9) was active early in feather evolution

Liberal Government and the Practical History of Anthropology

This paper explores the implications of Foucault's perspective of liberal government for approaches to the practical history of anthropology. It also draws on assemblage theory to consider the changing relations between field, museum and university in relation to a range of early twentieth-century anthropological practices. These focus mainly on the development of the Boasian paradigm in the USA during the inter-war years and on the anthropological practices clustered around the Musée de l'Homme in the 1930s. Key steps in the argument focus on the role of what Foucault called "transactional realities" in mediating the practical applications of anthropology in colonial contexts and in "anthropology at home" projects. Special consideration is also given to the increasingly archival properties of anthropological collections in the early twentieth century and the consequences of this for anthropology's relations to practices of governing

Prompt Release Cases of Vessels and Their Crew before ITLOS : How to Resolve Desputes in Appropriate Forums

We describe a new large-sized species of hypercarnivorous hyainailourine-Kerberos langebadreae gen. & sp. nov.-from the Bartonian (MP16) locality of Montespieu (Tarn, France). These specimens consist of a skull, two hemimandibles and several hind limb elements (fibula, astragalus, calcaneum, metatarsals, and phalanges). Size estimates suggest K. langebadreae may have weighed up to 140 kg, revealing this species as the largest carnivorous mammal in Europe at that time. Besides its very large size, K. langebadreae possesses an interesting combination of primitive and derived features. The distinctive skull morphology of K. langebadreae reflects a powerful bite force. The postcranial elements, which are rarely associated with hyainailourine specimens, indicate an animal capable of a plantigrade stance and adapted for terrestrial locomotion. We performed the first phylogenetic analysis of hyainailourines to determine the systematic position of K. langebadreae and to understand the evolution of the group that includes other massive carnivores. The analysis demonstrates that Hemipsalodon, a North American taxon, is a hyainailourine and is closely related to European Paroxyaena. Based on this analysis we hypothesize the biogeographic history of the Hyainailourinae. The group appeared in Africa with a first migration to Europe during the Bartonian that likely included the ancestors of Kerberos, Paroxyaena and Hemipsalodon, which further dispersed into North America at this time. We propose that the hyainailourines dispersed into Europe also during the Priabonian. These migrants have no ecological equivalent in Europe during these intervals and likely did not conflict with the endemic hyaenodont proviverrines. The discovery of K. langebadreae shows that large body size appears early in the evolution of hyainailourines. Surprisingly, the late Miocene Hyainailouros shares a more recent common ancestor with small-bodied hyainailourines (below 15 kg). Finally, our study supports a close relationship between the Hyainailourinae and Apterodontinae and we propose the new clade: Hyainailouridae