1,357 research outputs found

    Origin and evolution of osmoregulatory mechanisms in blue-green algae as a function of metabolic and structural complexity: Reflections of precambrian paleobiology

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    Twenty-four of the twenty-nine cyanobacteria proposed for culture were successfully cultured. Betaines are discussed

    Theory of commensurable magnetic structures in holmium

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    The tendency for the period of the helically ordered moments in holmium to lock into values which are commensurable with the lattice is studied theoretically as a function of temperature and magnetic field. The commensurable effects are derived in the mean-field approximation from numerical calculations of the free energy of various commensurable structures, and the results are compared with the extensive experimental evidence collected during the last ten years on the magnetic structures in holmium. In general the stability of the different commensurable structures is found to be in accord with the experiments, except for the tau=5/18 structure observed a few degrees below T_N in a b-axis field. The trigonal coupling recently detected in holmium is found to be the interaction required to explain the increased stability of the tau=1/5 structure around 42 K, and of the tau=1/4 structure around 96 K, when a field is applied along the c-axis.Comment: REVTEX, 31 pages, 7 postscript figure

    Lieb's Theorem and Maximum Entropy Condensates

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    The maximum entropy steady states which form upon Floquet heating of the ground state of the Hubbard model on unbalanced bi-partite lattices are shown to possess uniform finite off-diagonal long-range order in the thermodynamic limit. For repulsive interactions the induced order corresponds to the formation of a spin-wave condensate, whilst for attractive interactions it instead corresponds to the formation of a superconducting, η\eta-paired condensate. This creation of a `hot' condensate can occur on any periodically driven unbalanced lattice where the relevant SU(2) symmetry is preserved. Our results provide an understanding of how strong driving can expose order which has been suppressed by the lattice geometry - independent of any microscopic parameters. We discuss the implications of this for recent experiments observing emergent superconductivity in solid-state photoexcited compounds.Comment: 5 pages, 2 figures, comments are welcom

    VegMachine.net. Online land cover analysis for the rangelands

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    VegMachine.net is an online land cover monitoring tool unded by the Fitzroy Basin Association (FBA). The tool focuses primarily on Queensland, but has functionality for much of Australia’s rangelands. The website went live in July 2016 and recently logged the 1000th user session. Users can view seven different seasonal time series of cover products across the landscape and interactively interrogate and graph ground cover change in six different on-the-fly and email delivered reports. Results can then be exported for use in other software. To date, users have generated over 400 VegMachine® FORAGE ground cover reports which provide paddock-by-paddock, landtype-by-landtype analysis of ground cover change from 1990 to the present. Detailed help is available in multiple formats, including website popups and a dedicated YouTube channel. The web application was designed for two main user groups; technically equipped RD&E personnel including those servicing land manager clients, and a subset of the grazier community willing to operate the service themselves. Initial rollout of the application focused primarily on training events for government agency, private consultancy and natural resource management (NRM) staff in regional Queensland. These users form the core of the current user base. In this paper, we outline the development of VegMachine.net. We demonstrate the primary functionality of the website, provide an overview of user experience including a case study and discuss major learnings and future directions

    VegMachine.net. online land cover analysis for the Australian rangelands

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    This paper documents the development and use of the VegMachine.net land cover monitoring tool. From 2002 to 2015, VegMachine® software was used by government agencies, natural resource management (NRM) groups and individual pastoralists in northern Australia to assess and benchmark vegetation cover levels. In 2016 the VegMachine.net website was launched to build a wider user base and assure service continuity. Users can now graph historical (1990-) cover on one or more user defined areas of interest (AOI), produce comprehensive paddock-by-paddock property monitoring reports, and view a range of land cover raster images through the website map panel. In its first 32 months of operation 913 users logged 1604 sessions on the website and more than 1000 of the website's most comprehensive monitoring reports were distributed to users. Levels of use varied 26% of users (n = 237) have used the website more than once, and within this group a smaller set of regular users (n = 36) have used the site more than five times, in many cases to provide analyses to multiple clients. We outline four case studies that document the significant impact VegMachine.net has had on users including graziers, government agencies, NRM groups and researchers. We also discuss some possible paths forward that could widen the user base and improve retention of first time users. © 2019 The State of Queensland (through the Department of Agriculture and Fisheries) 2019 Open Access

    Geographical Differences in the Forefoot Morphology – A Comparative Radiological Study of Feet in Malawi and UK

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    Background: Many skeletal morphological differences between populations have been reported with possible but unproven clinical importance. This study was aimed at identifying the normal radiographic findings and measurements seen in patients from Southern Africa and compares them to a European population’s values.Methods: AP foot radiographs of 40 adults from Blantyre, Malawi were compared with those of 40 adults from London, UK. For each patient, measurements were taken of: 1st and 2nd metatarsal lengths, the 1st/2nd intermetatarsal angle, the 1st metatarso- phalangeal angle (the ‘bunion’ angle), and the 2nd metatarsal mortice joint medial and lateral depths.Results: Our results show an increased 1st/2nd metatarsal angle in Malawian feet, but a reduced ‘bunion’ angle. We also found the second metatarsal length to be longer relative to the first in the Malawian foot, and the 2nd metatarsal base to be significantly more covered by its mortice than in UK feet.Conclusion: This racial anatomical variation may convey more stability and less risk of a Lisfranc dislocation. It is also important to be aware of the normal range of these values when considering the need for forefoot arthroplasty procedures

    Doing a Good Job at a Bad Thing: Prevalence and Perpetuation of Stereotypes Among Members of Historically Black Sororities

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    This study examined how stereotypes among alumnae members of historically Black sororities affected their experiences as both undergraduate and graduate members. This research contributes to the literature on skin color bias and to the stereotypes of Black women. For the majority of women we surveyed for this research, the myths and stereotypes surrounding skin color bias, intra-racial group relations, beauty, and femininity of different historically Black sororities influenced the initial perceptions of members in each group. The findings include some commonality among stereotypes about the oldest sororities (Alpha Kappa Alpha and Delta Sigma Theta), yet stereotypes about the other organizations (Zeta Phi Beta and Sigma Gamma Rho) varied due to age, college life experience, and the geographic location of the interviewees. Implications and considerations for future research are included

    A comparison of high-throughput techniques for assaying circadian rhythms in plants

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    Over the last two decades, the development of high-throughput techniques has enabled us to probe the plant circadian clock, a key coordinator of vital biological processes, in ways previously impossible. With the circadian clock increasingly implicated in key fitness and signalling pathways, this has opened up new avenues for understanding plant development and signalling. Our tool-kit has been constantly improving through continual development and novel techniques that increase throughput, reduce costs and allow higher resolution on the cellular and subcellular levels. With circadian assays becoming more accessible and relevant than ever to researchers, in this paper we offer a review of the techniques currently available before considering the horizons in circadian investigation at ever higher throughputs and resolutions
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