1,066 research outputs found

    First record of Chrysopelea taprobanica Smith, 1943 (Squamata: Colubridae) from India

    Get PDF
    Chrysopelea taprobanica Smith, 1943 was previously considered to be endemic to the dry and intermediate zones of Sri Lanka. However, an adult specimen of C. taprobanica was collected from Seshachalam Biosphere Reserve of Andhra Pradesh, India, being the first record of this snake species from India, significantly extending the known range of distribution of the species. The dry zones of peninsular India were connected with Sri Lanka as recently as ca. 17,000 years ago, which probably allowed movement of species between these two regions

    The Suaineadh Project : a stepping stone towards the deployment of large flexible structures in space

    Get PDF
    The Suaineadh project aims at testing the controlled deployment and stabilization of space web. The deployment system is based on a simple yet ingenious control of the centrifugal force that will pull each of the four daughters sections apart. The four daughters are attached onto the four corners of a square web, and will be released from their initial stowed configuration attached to a central hub. Enclosed in the central hub is a specifically designed spinning reaction wheel that controls the rotational speed with a closed loop control fed by measurements from an onboard inertial measurement sensor. Five other such sensors located within the web and central hub provide information on the surface curvature of the web, and progression of the deployment. Suaineadh is currently at an advanced stage of development: all the components are manufactured with the subsystems integrated and are presently awaiting full integration and testing. This paper will present the current status of the Suaineadh project and the results of the most recent set of tests. In particular, the paper will cover the overall mechanical design of the system, the electrical and sensor assemblies, the communication and power systems and the spinning wheel with its control system

    On the deflection of asteroids with mirrors

    Get PDF
    This paper presents an analysis of an asteroid deflection method based on multiple solar concentrators. A model of the deflection through the sublimation of the surface material of an asteroid is presented, with simulation results showing the achievable orbital deflection with, and without, accounting for the effects of mirror contamination due to the ejected debris plume. A second model with simulation results is presented analyzing an enhancement of the Yarkovsky effect, which provides a significant deflection even when the surface temperature is not high enough to sublimate. Finally the dynamical model of solar concentrators in the proximity of an irregular celestial body are discussed, together with a Lyapunov-based controller to maintain the spacecraft concentrators at a required distance from the asteroid

    Microsatellite discovery in an insular amphibian (Grandisonia alternans) with comments on cross-species utility and the accuracy of locus identification from unassembled Illumina data

    Get PDF
    The Seychelles archipelago is unique among isolated oceanic islands because it features an endemic radiation of caecilian amphibians (Gymnophiona). In order to develop population genetics resources for this system, we identified microsatellite loci using unassembled Illumina MiSeq data generated from a genomic library of Grandisonia alternans, a species that occurs on multiple islands in the archipelago. Applying a recently described method (PALFINDER) we identified 8001 microsatellite loci that were potentially informative for population genetics analyses. Of these markers, we screened 60 loci using five individuals, directly sequenced several amplicons to confirm their identity, and then used eight loci to score allele sizes in 64 G. alternans individuals originating from five islands. A number of these individuals were sampled using non-lethal methods, demonstrating the efficacy of non-destructive molecular sampling in amphibian research. Although two loci satisfied our criteria as diploid, neutrally evolving loci with the statistical power to detect population structure, our success in identifying reliable loci was very low. Additionally, we discovered some issues with primer redundancy and differences between Illumina and Sanger sequences that suggest some Illumina-inferred loci are invalid. We investigated cross-species utility for eight loci and found most could be successfully amplified, sequenced and aligned across other species and genera of caecilians from the Seychelles. Thus, our study in part supported the validity of using PALFINDER with unassembled reads for microsatellite discovery within and across species, but importantly identified major limitations to applying this approach to small datasets (ca. 1 million reads) and loci with small tandem repeat sizes

    Multi-locus phylogeny and species delimitation of Australo-Papuan blacksnakes (Pseudechis Wagler, 1830: Elapidae: Serpentes)

    Get PDF
    Genetic analyses of Australasian organisms have resulted in the identification of extensive cryptic diversity across the continent. The venomous elapid snakes are among the best-studied organismal groups in this region, but many knowledge gaps persist: for instance, despite their iconic status, the species-level diversity among Australo-Papuan blacksnakes (Pseudechis) has remained poorly understood due to the existence of a group of cryptic species within the P. australis species complex, collectively termed ‘‘pygmy mulga snakes”. Using two mitochondrial and three nuclear loci we assess species boundaries within the genus using Bayesian species delimitation methods and reconstruct their phylogenetic history using multispecies coalescent approaches. Our analyses support the recognition of 10 species, including all of the currently described pygmy mulga snakes and one undescribed species from the Northern Territory of Australia. Phylogenetic relationships within the genus are broadly consistent with previous work, with the recognition of three major groups, the viviparous red-bellied black snake P. porphyriacus forming the sister species to two clades consisting of ovoviviparous specie

    Daisyworld: a review

    No full text
    Daisyworld is a simple planetary model designed to show the long-term effects of coupling between life and its environment. Its original form was introduced by James Lovelock as a defense against criticism that his Gaia theory of the Earth as a self-regulating homeostatic system requires teleological control rather than being an emergent property. The central premise, that living organisms can have major effects on the climate system, is no longer controversial. The Daisyworld model has attracted considerable interest from the scientific community and has now established itself as a model independent of, but still related to, the Gaia theory. Used widely as both a teaching tool and as a basis for more complex studies of feedback systems, it has also become an important paradigm for the understanding of the role of biotic components when modeling the Earth system. This paper collects the accumulated knowledge from the study of Daisyworld and provides the reader with a concise account of its important properties. We emphasize the increasing amount of exact analytic work on Daisyworld and are able to bring together and summarize these results from different systems for the first time. We conclude by suggesting what a more general model of life-environment interaction should be based on

    Old and New Horizons: The Information Resource Preferences of Hobbyists Before and After a Research Session

    Get PDF
    The goal of this paper is to carry out a qualitative and exploratory study of craft or maker hobbyists and their resource preferences over a single search session. The study uses information source horizon maps as the main tool of data collection alongside diary entries. Participants are asked to draw their information source horizons maps before and after their search session. Data analysis was carried out with content analysis and by applying various frameworks and models, such as Stebbins’ serious leisure, Savolainen’s everyday life information seeking, and Bates’ fundamental forms of information. The study is designed to be qualitative and exploratory. The paper gives recommendations on creating LibGuides regarding craft hobbies from the data and analysis carried out.Master of Science in Information Scienc

    Implementation and effects of user participation in playground management: a comparative study of two Swedish municipalities

    Get PDF
    This paper describes and analyses how customer orientation strategies, with the focus on user participation, are implemented in playground management and their effects on managers’ attitudes and work with physical playgrounds. A comparative case study was conducted in two Swedish municipalities that involve users in different ways: through a manager-driven participation process and through informal user-initiated dialogue. The empirical material consisted of qualitative interviews with professionals in the management organisations and studies of local playgrounds. Implementation of strategies for user participation and tactical management activities appeared to be of importance. The manager-driven participation strategy was associated with a particularly positive attitude among managers, but also difficulties such as maintaining continuous dialogue with users. The small differences found in playground provision between the two municipalities give reason to question the physical effects of participation processes, and show the need for further research

    Improving Access to Physical Activity: Revitalizing the Old Kona Airport Walking/Jogging Path

    Get PDF
    Environmental approaches to increase access to physical activity facilities are recommended for promoting physical activity. People with easy access to recreational facilities are more likely to achieve the recommended levels of physical activity, and neighborhoods that are walkable and provide access to public parks and jogging trails are associated with higher levels of activity. Friends for Fitness, a grassroots organization in West Hawai‘i spearheaded a community-based planning process and intervention to revitalize the Old Kona Airport into a walking/jogging trail. Through community engagement, support from local media and businesses, and volunteers, Friends for Fitness succeeded in increasing physical activity among residents. After three years, the number of walkers utilizing the trail increased more than 20%

    Menu labelling and food choice in obese adults: a feasibility study.

    Get PDF
    BACKGROUND: To date research examining the benefits of menu labelling in the UK is sparse. The aim of the present study was to examine the impact of menu labelling in a UK obese population. METHODS: Using a repeated measures design, 61 patients at a tier 3 weight management service completed four questionnaires to assess their food choice (control) and behaviour change when presented with 3 menu labelling formats (calorie content; nutrient content; and energy expenditure). RESULTS: All three forms of labelling increased participants weight control concerns compared to the control condition. There was a significant difference in content of food ordered in the three menu labelling formats compared to the control condition. The calorie condition had the largest percentage decrease in calories selected followed by energy expenditure and nutrient content. However, no difference was observed between the three conditions in the desire for menu labelling in restaurants to be introduced in the UK. CONCLUSIONS: The findings suggest that menu labelling should be enforced in the UK as it is both beneficial to promoting healthy eating and in demand. This study is the first to examine menu labelling in a UK obese population using energy expenditure equivalents to provide nutritional information
    corecore