2,301 research outputs found

    Demographic estimates from the Palaeolithic–Mesolithic boundary in Scandinavia: comparative benchmarks and novel insights

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    Prehistoric demography has recently risen to prominence as a potentially explanatory variable for episodes of cultural change as documented in the archaeological and ethnographic record. While this has resulted in a veritable boom in methodological developments seeking to address temporal changes in the relative size of prehistoric populations, little work has focused on the manner in which population dynamics manifests across a spatial dimension. Most recently, the so-called Cologne Protocol has led the way in this endeavour. However, strict requirements of raw-material exchange data as analytical inputs have prevented further applications of the protocol to regions outside of continental Europe. We apply an adjusted approach of the protocol that makes it transferable to cases in other parts of the world, while demonstrating its use by providing comparative benchmarks of previous research on the Late Glacial Final Palaeolithic of southern Scandinavia, and novel insights from the early Holocene pioneer colonization of coastal Norway. We demonstrate again that population size and densities remained fairly low throughout the Late Glacial, and well into the early Holocene. We suggest that such low population densities have played a significant role in shaping what may have been episodes of cultural loss, as well as potentially longer periods of only relatively minor degrees of cultural change. This article is part of the theme issue ‘Cross-disciplinary approaches to prehistoric demography’.publishedVersio

    Adjusting the Factory Planning Process when Using Immature Technologies

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    Due to shorter product-life-cycles, innovations in production engineering have to keep pace with today\u27s technologies. As a result, factory planning is more and more challenged by technologies being immature for series production. Usually, these immature technologies place special demands on production layout and quality management, for example. These demands have to be considered in the factory planning process. Moreover, technologies are part of the production process that is created by a series of technologies. Hence, a planning process has to ensure that the positive aspects of a new technology are not negated by arrangements to protect the technology chain against failure due to immature technologies. With Selective Laser Melting (SLM) used as example for an additive manufacturing technology, this paper presents a method of planning a production system by taking the technology maturity into account. Possible requirements of an immature technology interacting with the process chain will be addressed as well as adjustments to be made to the factory planning process

    Leading innovation in an interorganizational team together : the moderating role of shared leadership behavior in the transitioning between different phases of the open innovation process

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    Purpose – This study aims to contribute to the open innovation (OI) literature by investigating the transitions between three phases in the OI process (i.e. idea generation, idea promotion and idea realization) and how these are moderated by different forms of shared leadership (i.e. transactional, and transformational) as perceived by participants in the OI process. Design/methodology/approach – The authors tested a set of hypotheses using moderated mediation PLSSEM models on a bootstrapped sample of OI participants (N 5 173). Findings – The authors found a direct relationship between idea generation and realization, as well as indirectly through idea promotion. This study implies that the promotion of ideas by participants can be beneficial in inter-organizational OI teams, as promotion of ideas provides a linkage between the generation of ideas and the idea realization phase. However, while shared leadership has been shown to be beneficial in conventional teams, the authors found evidence that this may not be the case in inter-organizational OI teams. Higher levels of shared transformational leadership from colleagues with whom employees do not share the same organizational background may hamper the promotion of ideas. Originality/value – In contrast to the mainstream view, the authors found significant evidence that transformational shared leadership negatively moderates the direct relationship between idea generation and the promotion of ideas and the indirect relationship between idea generation and realization via idea promotion.info:eu-repo/semantics/publishedVersio

    Underactuated Waypoint Trajectory Optimization for Light Painting Photography

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    Despite their abundance in robotics and nature, underactuated systems remain a challenge for control engineering. Trajectory optimization provides a generally applicable solution, however its efficiency strongly depends on the skill of the engineer to frame the problem in an optimizer-friendly way. This paper proposes a procedure that automates such problem reformulation for a class of tasks in which the desired trajectory is specified by a sequence of waypoints. The approach is based on introducing auxiliary optimization variables that represent waypoint activations. To validate the proposed method, a letter drawing task is set up where shapes traced by the tip of a rotary inverted pendulum are visualized using long exposure photography.Comment: Accepted for ICRA 2020 (International Conference on Robotics and Automation

    Novel targeted strategies to overcome resistance in small-cell lung cancer: focus on PARP inhibitors and rovalpituzumab tesirine

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    ABSTRACTIntroduction: Small-cell lung cancer (SCLC) is a highly aggressive neuroendocrine tumour, and its outcome is strongly conditioned by the rapid onset of resistance to conventional chemothera..

    LCA on wastewater and sludge management for local decision-making in Gothenburg – are new LCA method developments enough?

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    This paper describes an LCA study that was made to inform decision-makers in Gothenburg about two different sludge management options. Incineration of anaerobically digested sludge with recovery of a phosphorus fertiliser product seemed preferable to using pasteurised anaerobically digested sludge in agriculture. Aspects under the control of the decision-makers were important for overall results, and caused the main differences between the studied systems, indicating considerable potential for local improvement efforts. Applying a human toxicity characterisation method with a more sludge specific fate model were important, but not crucial, for the results. However, the results are connected to large uncertainties and remaining challenges are discussed in the paper

    Cellular Responses in Sea Fan Corals: Granular Amoebocytes React to Pathogen and Climate Stressors

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    BACKGROUND: Climate warming is causing environmental change making both marine and terrestrial organisms, and even humans, more susceptible to emerging diseases. Coral reefs are among the most impacted ecosystems by climate stress, and immunity of corals, the most ancient of metazoans, is poorly known. Although coral mortality due to infectious diseases and temperature-related stress is on the rise, the immune effector mechanisms that contribute to the resistance of corals to such events remain elusive. In the Caribbean sea fan corals (Anthozoa, Alcyonacea: Gorgoniidae), the cell-based immune defenses are granular acidophilic amoebocytes, which are known to be involved in wound repair and histocompatibility. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate for the first time in corals that these cells are involved in the organismal response to pathogenic and temperature stress. In sea fans with both naturally occurring infections and experimental inoculations with the fungal pathogen Aspergillus sydowii, an inflammatory response, characterized by a massive increase of amoebocytes, was evident near infections. Melanosomes were detected in amoebocytes adjacent to protective melanin bands in infected sea fans; neither was present in uninfected fans. In naturally infected sea fans a concurrent increase in prophenoloxidase activity was detected in infected tissues with dense amoebocytes. Sea fans sampled in the field during the 2005 Caribbean Bleaching Event (a once-in-hundred-year climate event) responded to heat stress with a systemic increase in amoebocytes and amoebocyte densities were also increased by elevated temperature stress in lab experiments. CONCLUSIONS/SIGNIFICANCE: The observed amoebocyte responses indicate that sea fan corals use cellular defenses to combat fungal infection and temperature stress. The ability to mount an inflammatory response may be a contributing factor that allowed the survival of even infected sea fan corals during a stressful climate event
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