181 research outputs found

    Production of Ultra-Cold-Neutrons in Solid \alpha-Oxygen

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    Our recent neutron scattering measurements of phonons and magnons in solid \alpha-oxygen have led us to a new understanding of the production mechanismen of ultra-cold-neutrons (UCN) in this super-thermal converter. The UCN production in solid \alpha-oxygen is dominated by the excitation of phonons. The contribution of magnons to UCN production becomes only slightly important above E >10 meV and at E >4 meV. Solid \alpha-oxygen is in comparison to solid deuterium less effcient in the down-scattering of thermal or cold neutrons into the UCN energy regime.Comment: 4 pages, 5 figuer

    Service robotics: do you know your new companion? Framing an interdisciplinary technology assessment

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    Service-Robotic—mainly defined as “non-industrial robotics”—is identified as the next economical success story to be expected after robots have been ubiquitously implemented into industrial production lines. Under the heading of service-robotic, we found a widespread area of applications reaching from robotics in agriculture and in the public transportation system to service robots applied in private homes. We propose for our interdisciplinary perspective of technology assessment to take the human user/worker as common focus. In some cases, the user/worker is the effective subject acting by means of and in cooperation with a service robot; in other cases, the user/worker might become a pure object of the respective robotic system, for example, as a patient in a hospital. In this paper, we present a comprehensive interdisciplinary framework, which allows us to scrutinize some of the most relevant applications of service robotics; we propose to combine technical, economical, legal, philosophical/ethical, and psychological perspectives in order to design a thorough and comprehensive expert-based technology assessment. This allows us to understand the potentials as well as the limits and even the threats connected with the ongoing and the planned implementation of service robots into human lifeworld—particularly of those technical systems displaying increasing grades of autonomy

    Dualities and dilemmas: contending with uncertainty in large-scale safety-critical projects

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    © 2016, Informa UK Limited, trading as Taylor & Francis Group. Uncertainty is a fact of project life. Most decisions that are made on a safety-critical project involve uncertainty, the consequences of which may be highly significant to the safe and timely delivery of the project. Based on interviews with project management practitioners on nine large-scale civil nuclear and aerospace projects, we explore how uncertainty emerges, and how project management practitioners identify, analyse and act on it. We make three important contributions. First, we present three approaches – structural, behavioural and relational – that individuals and organizations can adopt when contending with project uncertainty. Secondly, we characterize nine dualities at play in the management of project uncertainty and thirdly, we identify key differences between how civil nuclear and aerospace project managers confront project uncertainty, which have important implications for how projects might be organized in both these industry sectors. Drawing attention to the structural, behavioural and relational approaches to project uncertainty and the tensions that manifest themselves in each approach should enable the project management community to make progress in environments of high uncertainty where situations are often complex, rapidly changing and confusing, and yet where, for reasons of safety, failure is not an option

    Intravesical Treatments of Bladder Cancer: Review

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    For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy

    Organisationskultur. Eine Konkretisierung aus systemtheoretischer Perspektive

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    Kühl S. Organisationskultur. Eine Konkretisierung aus systemtheoretischer Perspektive. Managementforschung. 2018;28(1):7-35.Die Bestimmung des Verhältnisses von Informalität und Organisationskultur bereitet in der Organisationstheorie Schwierigkeiten. Das liegt daran, dass der Begriff Informalität häufig stillschweigend durch den Begriff der Organisationskultur ersetzt wurde, ohne dass dafür eine präzise, abgrenzungsscharfe Definition vorgenommen worden wäre. Unter Rückgriff auf Überlegungen von Dario Rodríguez argumentiert dieser Artikel, dass die beiden Begriffe Organisationskultur und Informalität das gleiche Phänomen bezeichnen: die nichtentschiedenen Entscheidungsprämissen einer Organisation. Dabei wird systematisch zwischen „unentscheidbaren Entscheidungsprämissen“ und „prinzipiell entscheidbaren, aber nicht entschiedenen Entscheidungsprämissen“ unterschieden. Es wird gezeigt, wie sich mit einer präzisen Bestimmung über das Konzept der Entscheidungsprämissen Ordnung in die „wilden Merkmallisten“ der Literatur sowohl über Informalität als auch Organisationskultur bringen lässt und empirische Phänomene genauer erfasst werden können

    Surviving in isolation: genetic variation, bottlenecks and reproductive strategies in the Canarian endemic Limonium macrophyllum (Plumbaginaceae)

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    Oceanic archipelagos are typically rich in endemic taxa, because they offer ideal conditions for diversification and speciation in isolation. One of the most remarkable evolutionary radiations on the Canary Islands comprises the 16 species included in Limonium subsection Nobiles, all of which are subject to diverse threats, and legally protected. Since many of them are single-island endemics limited to one or a few populations, there exists a risk that a loss of genetic variation might limit their longterm survival. In this study, we used eight newly developed microsatellite markers to characterize the levels of genetic variation and inbreeding in L. macrophyllum, a species endemic to the North-east of Tenerife that belongs to Limonium subsection Nobiles. We detected generally low levels of genetic variation over all populations (HT = 0.363), and substantial differentiation among populations (FST = 0.188;RST = 0.186) coupled with a negligible degree of inbreeding (F = 0.042). Obligate outcrossing may have maintained L. macrophyllum relatively unaffected by inbreeding despite the species’ limited dispersal ability and the genetic bottlenecks likely caused by a prolonged history of grazing. Although several factors still constitute a risk for the conservation of L. macrophyllum, the lack of inbreeding and the recent positive demographic trends observed in the populations of this species are factors that favour its future persistence
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