2,665 research outputs found

    What do alligators eat on golf courses?

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    Urbanization is an ever-increasing threat to wildlife and their natural habitats, yet research has been limited to a small number of taxa and very few large predator species. The American alligator (Alligator mississippiensis) is an apex predator across the southeast U.S. and has surprisingly received minimal attention within urban areas. To investigate the potential effects of land development on alligator trophic ecology, we performed gut content analysis on golf course alligators found on Jekyll Island, Georgia. We then made comparisons with alligators found in more natural areas on Sapelo Island, Georgia. In total, we collected stomach content samples from 25 alligators on Jekyll Island golf courses, of which only one had an empty stomach. Data provided from Sapelo Island consisted of 93 alligators within our alligator size range, of which only one had an empty stomach. While analysis of similarity, non-metric multidimensional scaling, and simplified Morisita index analyses show no significant difference in diets between the two areas (possibly because of a low sample size from Jekyll Island), %IRI values for prey items reveal that there may be functional differences in prey choice or availability. Further land development and increasing human activity may therefore shift diets toward reliance on prey items usually of lesser importance. These trophic effects could possibly lead to local population declines, if paired with habitat degradation or other stressors

    Effects of Cathode Configuration on Hall Thruster Cluster Plume Properties

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76620/1/AIAA-24636-518.pd

    Correspondence from E.B. Lovejoy, August 13, 1862

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    Correspondence from E.B. Lovejoy regarding absent soldiers from Androscoggin Countyhttps://digitalmaine.com/absent_soldiers/1005/thumbnail.jp

    Questioning policy, youth participation and lifestyle sports

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    Young people have been identified as a key target group for whom participation in sport and physical activity could have important benefits to health and wellbeing and consequently have been the focus of several government policies to increase participation in the UK. Lifestyle sports represent one such strategy for encouraging and sustaining new engagements in sport and physical activity in youth groups, however, there is at present a lack of understanding of the use of these activities within policy contexts. This paper presents findings from a government initiative which sought to increase participation in sport for young people through provision of facilities for mountain biking in a forest in south-east England. Findings from qualitative research with 40 young people who participated in mountain biking at the case study location highlight the importance of non-traditional sports as a means to experience the natural environments through forms of consumption which are healthy, active and appeal to their identities. In addition, however, the paper raises questions over the accessibility of schemes for some individuals and social groups, and the ability to incorporate sports which are inherently participant-led into state-managed schemes. Lifestyle sports such as mountain biking involve distinct forms of participation which present a challenge for policy-makers who seek to create and maintain sustainable communities of youth participants

    Nonanalytic behavior of the spin susceptibility in clean Fermi systems

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    The wavevector and temperature dependent static spin susceptibility, \chi_s(Q,T), of clean interacting Fermi systems is considered in dimensions 1\leq d \leq 3. We show that at zero temperature \chi_s is a nonanalytic function of |Q|, with the leading nonanalyticity being |Q|^{d-1} for 1<d<3, and Q^2\ln|Q| for d=3. For the homogeneous spin susceptibility we find a nonanalytic temperature dependence T^{d-1} for 1<d<3. We give qualitative mode-mode coupling arguments to that effect, and corroborate these arguments by a perturbative calculation to second order in the electron-electron interaction amplitude. The implications of this, in particular for itinerant ferromagnetism, are discussed. We also point out the relation between our findings and established perturbative results for 1-d systems, as well as for the temperature dependence of \chi_s(Q=0) in d=3.Comment: 12pp., REVTeX, 5 eps figures, final version as publishe

    Variability and coherence of the Agulhas Undercurrent in a High-resolution Ocean General Circulation Model

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    The Agulhas Current system has been analyzed in a nested high-resolution ocean model and compared to observations. The model shows good performance in the western boundary current structure and the transports off the South African coast. This includes the simulation of the northward-flowing Agulhas Undercurrent. It is demonstrated that fluctuations of the Agulhas Current and Undercurrent around 50–70 days are due to Natal pulses and Mozambique eddies propagating downstream. A sensitivity experiment that excludes those upstream perturbations significantly reduces the variability as well as the mean transport of the undercurrent. Although the model simulates undercurrents in the Mozambique Channel and east of Madagascar, there is no direct connection between those and the Agulhas Undercurrent. Virtual float releases demonstrate that topography is effectively blocking the flow toward the north

    Progress and Prospects for a Nucleic Acid Screening Test Set

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    Objective: DNA synthesis companies screen orders to detect controlled sequences with misuse risks. Assessing screening accuracy is challenging owing to the breadth of biological risks and ambiguities in risk definitions. Here, we detail an International Gene Synthesis Consortium working group’s rationale and process to develop a prototype DNA synthesis screening test dataset, aiming to establish a baseline of screening system accuracy to compare with various screening approaches.Methodology: Construction of the prototype test dataset involved four tool developers screening nucleic acid sequences from three taxonomic clusters of controlled organisms (Orbivirus, Francisella tularensis, and Coccidioides). Results were mapped onto predefined, comparable categories, checking for consensus or conflicts. Conflicts were grouped based on gene annotation and resolved through discussion.Results: The process highlighted several long-standing challenges in DNA synthesis screening, including the qualitative differences in approaches taken by screening tools. Our findings highlight the lack of clarity in assessing pathogen sequences with respect to regulatory control language, compounded by scientific uncertainty. We illustrate the current degree of consensus and existing challenges using classification statistics and specific examples.Conclusions and Next Steps: This prototype underscores the necessity of expert-regulator coordination in assessing gene-associated risks, offering a template for creating test sets across all taxonomic groups on international control lists. Expanding the working group would enrich dataset comprehensiveness, enabling a transition from species-focused to function-focused regulatory controls. This sets the foundation for quality control, certification, and improved risk assessment in DNA synthesis screening
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