2,447 research outputs found

    Fungal Spore Dispersal by the Eastern Box Turtle (Terrapene carolina carolina)

    Get PDF
    Although spores from most macrofungi are wind- or water-dispersed, dispersal may also occur via biotic vectors. The Eastern box turtle (Terrapene carolina carolina) is a facultative mycovore that may play an important role in fungal spore dispersal although, to date, no information exists on fungi occurring in fecal samples of box turtles or on the ecological significance of box turtles as spore dispersal vectors. Consequently, a study of the potential for Eastern box turtles to act as vectors for spore dispersal was initiated by capturing wild turtles and collecting fecal samples. Serial dilutions from fecal samples were made to enumerate spores, quantify the number of spores per gram of fecal material and to isolate and identify fungi. Fungal spores were found to be extremely abundant throughout all samples. Fecal samples from 36 turtles yielded a total of 23 different fungal taxa in the Zygomycota, Ascomycota and Basidiomycota. Two yeasts that were isolated, Cryptococcus albidus and Rhodotorula mucilaginosa, are reported to naturally occur on Trifolium seeds found in fecal samples. A mold previously unreported from fecal material, Aspergillus wentii, was also found in fecal samples. Data collected suggests Eastern box turtles influence fungal spore dispersal by browsing on plant materials and defecating large numbers of fungal spores within their home ranges

    Man and His Environment: The Ecological Limits of Optimism

    Get PDF

    Diffusion Monte Carlo calculations for the ground states of atoms and ions in neutron star magnetic fields

    Full text link
    The diffusion quantum Monte Carlo method is extended to solve the old theoretical physics problem of many-electron atoms and ions in intense magnetic fields. The feature of our approach is the use of adiabatic approximation wave functions augmented by a Jastrow factor as guiding functions to initialize the quantum Monte Carlo prodecure. We calcula te the ground state energies of atoms and ions with nuclear charges from Z= 2, 3, 4, ..., 26 for magnetic field strengths relevant for neutron stars.Comment: 6 pages, 1 figure, proceedings of the "9th International Conference on Path Integrals - New Trends and Perspectives", Max-Planck-Institut fur Physik komplexer Systeme, Dresden, Germany, September 23 - 28, 2007, to be published as a book by World Scientific, Singapore (2008

    Direct cost variance analysis of peroral endoscopic myotomy vs Heller myotomy for management of achalasia: A tertiary referral center experience

    Get PDF
    BACKGROUND: Laparoscopic Heller myotomy (LHM) has been the traditional surgical treatment for achalasia. Recently, peroral endoscopic myotomy (POEM) has demonstrated similar clinical outcomes with shorter procedure times. Studies comparing the direct cost-effectiveness of POEM AIM: To compare costs of POEM METHODS: This retrospective chart review aimed to compare the outcomes and cost of clinical care between patients who underwent POEM and LHM procedures for achalasia. The study was conducted at a tertiary academic center from January 2019 to December 2020. Clinical outcomes, including post-operative Eckardt scores and adverse events, were assessed and compared between the two groups. Direct cost variance analysis was utilized to evaluate the cost of clinical care incurred by patients undergoing POEM in the year preceding the procedure, during the index admission, and one year post-procedure, in comparison to patients undergoing LHM. RESULTS: Of 30 patients were included (15 POEM and 15 LHM) in the study. Patients in the POEM group had a mean Eckardt score of 0.5 ± 0.5 post-procedure, which was no different from patients in the LHM group (0.7 ± 0.6, CONCLUSION: Despite similar clinical outcomes, the cost of the index procedure admission for POEM was significantly lower than for LHM. The difference was primarily related to shorter time increments utilized in the operating room during the index procedure, and shorter length of hospital stay following POEM

    Hacking events: project development practices and technology use at hackathons

    Get PDF
    Hackathons are techno-creative events during which participants get together in a physical location. They may be hosted by civic communities, corporations or public institutions. Working individually or in teams, usually for several days, participants develop projects such as hardware or software prototypes. Based on a digital ethnography of two events in the Netherlands and Denmark, this article investigates project development practices at hackathons. In particular, it analyses how participants organized their project work and which technologies were used in support of their creative endeavours. Hackathons are increasingly competitive rather than collaborative events, involving time pressure, inducements such as prizes, and requiring efficient skills utilization. I argue that this facilitates the following tendencies: Firstly, strategic effort is put into final presentations. Projects need to be convincingly presented, and persuasively pitching an idea becomes crucial. Secondly, there is only limited time for personal learning, since participants’ existing skills need to be efficiently applied if a team wants to stay competitive. This encourages division of labour within groups: a tendency which seems especially problematic given that IT skills biases are often expressed in terms of gender. Thirdly, participants are more inclined to use technologies that are proprietary but appear ‘open enough’. In light of this observation and by drawing on the concept of technology as resource and opportunity, I discuss the techno-political implications of utilized technologies. With this analysis, I aim at contributing to the critical debate on hackathons as productive but likewise ideologically significant fields of ‘hacking cultures’

    Engaging with assessment: increasing student engagement through continuous assessment

    Get PDF
    Student engagement is intrinsically linked to two important metrics in learning: student satisfaction and the quality of the student experience. One of the ways that engagement can be influenced is through careful curriculum design. Using the knowledge that many students are ‘assessment-driven’ a low stakes continuous weekly summative e-assessment was introduced to a module. The impact this had on student engagement was measured by studying student activity within the module virtual learning environment (VLE). It was found that introduction of the e-assessments led to a significant increase in VLE activity compared to the VLE activity in that module the previous year, and also compared to the VLE activity of two other modules studied by the same student cohort. As many institutions move towards greater blended or online deliveries it will become more important to ensure that VLEs encourage high levels of student engagement in order to maintain or enhance the student experience. Keywords : continuous assessment, learning analytics, student engagement, virtual learning environment
    • …
    corecore