1,238 research outputs found

    The biomechanics of the locust ovipositor valves : a unique digging apparatus

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    The female locust has a unique mechanism for digging in order to deposit its eggs deep in the ground. It utilizes two pairs of sclerotized valves to displace the granular matter, while extending its abdomen as it propagates underground. This ensures optimal conditions for the eggs to incubate, and provides them with protection from predators. Here, two major axes of operation of the digging valves are identified, one in parallel to the propagation direction of the ovipositor, and one perpendicular to it. The direction-dependent biomechanics of the locust major, dorsal digging valves are quantified and analyzed, under forces in the physiological range and beyond, considering hydration level, as well as the females’ age, or sexual maturation state. Our findings reveal that the responses of the valves to compression forces in the specific directions change upon sexual maturation to follow their function, and depend on environmental conditions. Namely, in the physiological force range, the valves are resistant to mechanical failure. In addition, mature females, which lay eggs, have stiffer valves, up to roughly nineteen times the stiffness of the pre-mature locusts. The valves are stiffer in the major working direction, corresponding to soil shuffling and compression, compared to the direction of propagation. Hydration of the valves reduces their stiffness but increases their resilience against failure. These findings provide mechanical and materials guidelines for the design of novel non-drilling excavating tools, including 3D-printed anisotropic materials based on composites.Statement of significance The female locust lay its eggs underground in order to protect them from predators and to provide them with optimal conditions for hatching. In order to dig into the ground, it uses two pairs of valves: The ventral pair is plugged as a wedge, while the dorsal pair performs the digging of the oviposition tunnel. We study the mechanical response of the digging valves, depending on age, hydration level and direction of operation. Our findings show that during the course of roughly two weeks in the life of the adult female, the digging valves become up to nineteen-fold stiffer against failure, in order to fulfill their function as diggers. While hydration reduces the stiffness, it also increases the resilience against failure and renders the valves unbreakable within the estimated physiological force range and beyond. The digging valves are consistently stiffer in the digging direction than in the perpendicular direction, implying on their form-follows-function design.Competing Interest StatementThe authors have declared no competing interest

    One Specialty’s Collaborative Approach to Competency-Based Curriculum Development

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    The authors describe a seven-step consensus development process used to create the two most recent editions of the Academic Pediatric Association’s (APA’s) educational guidelines for pediatric residency. The 1996 (printed) and 2004 (online) editions of the guidelines were designed as flexible tools to help residency programs meet changing accreditation requirements by providing lists of goals and objectives and objective-based evaluation tools. The guidelines were developed in seven steps: (1) centralized national leadership combined with coordinated, disseminated authorship, (2) clear definition of targeted users and repeated assessment of their needs, (3) incorporation of up-to-date information from the literature and national experts, (4) responsive consultation with the national Pediatric Residency Review Committee on the latest accreditation requirements, (5) wide distribution for prepublication review, to obtain broad organizational buy-in and end-user acceptance, (6) intensive dissemination and faculty development through multiple national workshops over several years, and (7) careful evaluation of utilization and user feedback. Representatives of all major organizations involved in pediatric education helped to refine the guidelines. User surveys conducted for the 1996 edition, and Web site user data collected for the 2004 edition, demonstrate that both editions have been used by most residency programs throughout the country. The authors believe that the multifaceted approach to consensus development and the customizable design of the curricular tools in the APA’s guidelines are directly associated with their broad national use. These methods may help to guide educators in other disciplines who are interested in developing and implementing educational products for national dissemination and use

    Draft Genome Sequence of the Redox-Active Enteric Bacterium Citrobacter portucalensis Strain MBL

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    We grew a soil enrichment culture to identify organisms that anaerobically oxidize phenazine-1-carboxylic acid. A strain of Citrobacter portucalensis was isolated from this enrichment and sequenced by both Illumina and PacBio technologies. It has a genome with a length of 5.3 Mb, a G+C content of 51.8%, and at least one plasmid

    Draft Genome Sequence of the Redox-Active Enteric Bacterium Citrobacter portucalensis Strain MBL

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    We grew a soil enrichment culture to identify organisms that anaerobically oxidize phenazine-1-carboxylic acid. A strain of Citrobacter portucalensis was isolated from this enrichment and sequenced by both Illumina and PacBio technologies. It has a genome with a length of 5.3 Mb, a G+C content of 51.8%, and at least one plasmid

    Evaluation of the Use of an Interactive, Online Resource for Competency-Based Curriculum Development

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    Purpose To evaluate pediatric educators’ use of and satisfaction with the Academic Pediatric Association’s Educational Guidelines for Pediatric Residency. Method The authors used customized programming to document all registered users and downloaded files from the Guidelines Web site for a 30-month period after site completion. An online survey of volunteer users was conducted. Results Between July 2005 and December 2007, 1,747 individuals registered on the Web site, and 8,754 files were downloaded. Registrants who downloaded files (n = 1,239) represented 97% of the pediatric residency programs in 2008 that were approved by the Accreditation Council for Graduate Medical Education. During 30 months, the frequency of downloads remained robust, peaking each spring. Curriculum-building tools were downloaded by 97% of programs using the site; the majority chose predesigned formats rather than self-selected lists of goals and objectives. Resident evaluation forms and tutorials were downloaded less frequently. A survey was completed by 111 site users, who indicated that the Guidelines tools were useful for Residency Review Committee site visit preparation. Most respondents said that the curriculum-building tools were easy to use, adaptable, and helpful in integration of competencies into residency programs. Respondents rated tutorials highly for educational content and clarity

    A Theory of Organization-EHR Affordance Actualization

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    While organizations implement information technology (IT) to effect change, current theories of IT-associated organizational change pay insufficient attention to the change goals, the role of IT in organizational change, and the multilevel nature of change processes. We take a fresh look at IT-associated organizational change using grounded theory methods. Our longitudinal study of an electronic health record (EHR) system implementation in a multi-site medical group found user behaviors that did not fit well with existing theories. Instead, we found that they fit better with the concept of affordances from ecological psychology. In developing our affordance-based theory of IT-associated organizational change from our field data, we discovered three gaps in the affordance literature; namely, the lack of theory for (1) the process of actualizing an affordance’s potential, (2) affordances in an organizational context, and (3) bundles of interrelated affordances. This paper extends the theory of affordances to handle these three gaps and, in doing so, develops a mid-range theory for EHR-associated organizational change in a healthcare organization. While the resulting theory is specific to EHR implementations, it offers a template for other mid-range affordance-actualization theories and a more general affordance-actualization lens. Our affordance-actualization lens considers the materiality of the IT artifact, the non-deterministic process by which IT leads to organizational effects, the multilevel nature of IT-associated change processes, and the intentionality of managers and users as agents of change, and thus addresses important criteria for theories of IT effects in organizations. The paper also provides practical guidance for implementing EHR systems and other organizational systems

    Seasonality of Overseas Tourism Demand in Scotland: A Regional Analysis

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    This paper examines patterns of seasonality in international tourism to the regions of Scotland. Quarterly numbers of overnight stays are disaggregated by trip purpose. Seasonality in vacation tourism to Scotland is shown to be defined by more than a simple rural–urban division. Overseas visiting friends and relatives (VFR) tourism is largely an urban phenomenon and is consequently less seasonal than vacation tourism. Lower seasonal concentration of VFR tourism is not uniform across the regions. Although levels of seasonal intensity of business tourism to the three principal cities of Scotland are approximately the same, there are noticeable variations over time

    Learning To Be Affected: Social suffering and total pain at life’s borders.

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    The practice of Live Sociology in situations of pain and suffering is the author’s focus. An outline of the challenges of understanding pain is followed by a discussion of Bourdieu’s ‘social suffering’ (1999) and the palliative care philosophy of ‘total pain’. Using examples from qualitative research on disadvantaged dying migrants in the UK, attention is given to the methods that are improvised by dying people and care practitioners in attempts to bridge intersubjective divides, where the causes and routes of pain can be ontologically and temporally indeterminate and/or withdrawn. The paper contends that these latter phenomena are the incitement for the inventive bridging and performative work of care and Live Sociological methods, both of which are concerned with opposing suffering. Drawing from the ontology of total pain, I highlight the importance of (i) an engagement with a range of materials out of which attempts at intersubjective bridging can be produced, and which exceed the social, the material, and the temporally linear; and (ii) an empirical sensibility that is hospitable to the inaccessible and non-relational
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