953 research outputs found

    Weed problems in various tillage systems in the Nordic countries

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    There is an increasing use of various forms of reduced tillage or no-tillage in the Nordic countries. This will favour the growth of grass weed species and perennial species. Perennial creeping weeds like Elymus repens, Cirsium arvense, and Sonchus arvensis are important in all Nordic countries. Stationary weeds such as Taraxacum spp., Artemisia vulgaris and volunteer grassland species increase in areas with reduced tillage and especially no-tillage systems. Winter annual and biennial species such as Matricaria perforata, Poa annua, Alopecurus geniculatus and Stellaria media are frequently occuring weeds in reduced tillage systems in all countries, while Alopecurus myosuroides and Apera spica-venti are problems in Denmark and Southern parts of Sweden and Finland

    A First Comparison of the responses of a He4-based fast-neutron detector and a NE-213 liquid-scintillator reference detector

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    A first comparison has been made between the pulse-shape discrimination characteristics of a novel 4^{4}He-based pressurized scintillation detector and a NE-213 liquid-scintillator reference detector using an Am/Be mixed-field neutron and gamma-ray source and a high-resolution scintillation-pulse digitizer. In particular, the capabilities of the two fast neutron detectors to discriminate between neutrons and gamma-rays were investigated. The NE-213 liquid-scintillator reference cell produced a wide range of scintillation-light yields in response to the gamma-ray field of the source. In stark contrast, due to the size and pressure of the 4^{4}He gas volume, the 4^{4}He-based detector registered a maximum scintillation-light yield of 750~keVee_{ee} to the same gamma-ray field. Pulse-shape discrimination for particles with scintillation-light yields of more than 750~keVee_{ee} was excellent in the case of the 4^{4}He-based detector. Above 750~keVee_{ee} its signal was unambiguously neutron, enabling particle identification based entirely upon the amount of scintillation light produced.Comment: 23 pages, 7 figures, Nuclear Instruments and Methods in Physics Research Section A review addresse

    Retinoic Acid Drives Aryl Hydrocarbon Receptor Expression and Is Instrumental to Dioxin-Induced Toxicity during Palate Development

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    Background: Palate development depends on complex events and is very sensitive to disruption. Accordingly, clefts are the most common congenital malformations worldwide, and a connection is proposed with fetal exposure to toxic factors or environmental contaminants, such as dioxins. There is increasing evidence that dioxin interferes with all-trans-retinoic acid (atRA), a hormone-like signal derived from vitamin A, which plays an essential role during embryonic development. Although similarities have been described between dioxin-induced toxicity and the outcome of altered atRA signaling during palate development, their relationship needs to be clarified

    From Empowerment Dynamics to Team Adaptability: Exploring and Conceptualizing the Continuous Agile Team Innovation Process

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    To foster their innovation teams’ adaptability, organizations are increasingly relying on agile teams. While research on the adoption of agile methods and practices has grown tremendously in the past decade, little is currently known about the human side of agile teams and how it contributes toward the emergence of adaptability. While the Agile Manifesto states that individuals and interactions are more important for agile product development than tools and processes, research on how these interactions unfold is still in its infancy. To shed light on the human side of adaptability, 44 semi‐structured, in‐depth interviews were conducted with team members and leaders from various teams at three organizations (i.e., two German and one multinational European firm). The inductive analysis identified empowerment as a focal human factor for adaptability emergence. A model of the continuous agile team innovation process is developed and uncovers the importance of dynamic empowerment states and their temporary equilibria for team adaptability. The underlying findings demonstrate that empowerment is not a static state, but rather emerges through the interactions between various actors. Specifically, the team and its leader engage in both empowerment‐enhancing and empowerment‐reducing activities. These activities are further influenced by the agile team’s immediate context: Two‐fold customer influences, that is, supporting and hindering empowerment interactions, and the organizational environment, that is, undergoing an agile transformation and supportive top management behaviors, play an important role in affecting the empowerment dynamics that result in team adaptability. As such, this study contributes to the innovation and management literatures by revealing the dynamic role of the empowerment and adaptability constructs for agile innovation processes and the importance of various actors and the organizational environment for fostering adaptability. Practical insights are offered to management, teams, and team members on how to create conditions for empowerment dynamics and consequently adaptability to unfold

    Tagging fast neutrons from an 241Am/9Be source

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    We report on an investigation of the fast-neutron spectrum emitted by 241Am/9Be. Well-understood shielding, coincidence, and time-of-flight measurement techniques are employed to produce a continuous, polychromatic, energy-tagged neutron beam.Comment: 17 pages, 7 figures, submitted to Journal of Applied Radiation and Isotope

    A Search for Very High-Energy Gamma Rays from the Missing Link Binary Pulsar J1023+0038 with VERITAS

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    The binary millisecond radio pulsar PSR J1023+0038 exhibits many characteristics similar to the gamma-ray binary system PSR B1259--63/LS 2883, making it an ideal candidate for the study of high-energy non-thermal emission. It has been the subject of multi-wavelength campaigns following the disappearance of the pulsed radio emission in 2013 June, which revealed the appearance of an accretion disk around the neutron star. We present the results of very high-energy gamma-ray observations carried out by VERITAS before and after this change of state. Searches for steady and pulsed emission of both data sets yield no significant gamma-ray signal above 100 GeV, and upper limits are given for both a steady and pulsed gamma-ray flux. These upper limits are used to constrain the magnetic field strength in the shock region of the PSR J1023+0038 system. Assuming that very high-energy gamma rays are produced via an inverse-Compton mechanism in the shock region, we constrain the shock magnetic field to be greater than ∌\sim2 G before the disappearance of the radio pulsar and greater than ∌\sim10 G afterwards.Comment: 7 pages, 3 figures, accepted for publication in Ap

    Applications of Site-Specific Labeling to Study HAMLET, a Tumoricidal Complex of α-Lactalbumin and Oleic Acid

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    umor cells), and its tumoricidal activity has been well established.-acetylgalactosaminyltransferase II (ppGalNAc-T2) and further conjugated with aminooxy-derivatives of fluoroprobe or biotin molecules.We found that the molten globule form of hLA and αD-hLA proteins, with or without C-terminal extension, and with and without the conjugated fluoroprobe or biotin molecule, readily form a complex with OA and exhibits tumoricidal activity similar to HAMLET made with full-length hLA protein. The confocal microscopy studies with fluoroprobe-labeled samples show that these proteins are internalized into the cells and found even in the nucleus only when they are complexed with OA. The HAMLET conjugated with a single biotin molecule will be a useful tool to identify the cellular components that are involved with it in the tumoricidal activity
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