1,312 research outputs found
The culture of skilled work in a Norwegian shipyard, 1945-90
We anatomise the culture of skilled work in the Solheimsviken shipyard in Bergen, Norway, from 1945 to 1990, linking it to democratic impulses within the workforce. This independent culture had strong if bounded democratic elements that were ultimately reflected in the institutions of a workersâ cooperative which operated from1985. However, a shift away from shipbuilding immediately preceded the cooperativeâs foundation and eroded the position of the older skilled workers who had carried the culture, undermining it even before the cooperativeâs collapse
Digital Cavities and Their Potential Applications
The concept of a digital cavity is presented. The functionality of a tunable
radio-frequency/microwave cavity with unrestricted Q-factor is implemented. The
theoretical aspects of the cavity and its potential applications in high
resolution spectroscopy and synchronization of clocks together with examples in
signal processing and data acquisition are discussed
Topographical scattering of waves: a spectral approach
The topographical scattering of gravity waves is investigated using a
spectral energy balance equation that accounts for first order wave-bottom
Bragg scattering. This model represents the bottom topography and surface waves
with spectra, and evaluates a Bragg scattering source term that is
theoretically valid for small bottom and surface slopes and slowly varying
spectral properties. The robustness of the model is tested for a variety of
topographies uniform along one horizontal dimension including nearly
sinusoidal, linear ramp and step profiles. Results are compared with
reflections computed using an accurate method that applies integral matching
along vertical boundaries of a series of steps. For small bottom amplitudes,
the source term representation yields accurate reflection estimates even for a
localized scatterer. This result is proved for small bottom amplitudes
relative to the mean water depth . Wave reflection by small amplitude bottom
topography thus depends primarily on the bottom elevation variance at the Bragg
resonance scales, and is insensitive to the detailed shape of the bottom
profile. Relative errors in the energy reflection coefficient are found to be
typically .Comment: Second revision for Journal of Waterways Ports and Coastal
Engineerin
The causal interpretation of two-stage least squares with multiple instrumental variables
Empirical researchers often combine multiple instrumental variables (IVs) for a single treatment using two-stage least squares (2SLS). When treatment effects are heterogeneous, a common justification for including multiple IVs is that the 2SLS estimand can be given a causal interpretation as a positively weighted average of local average treatment effects (LATEs). This justification requires the well-known monotonicity condition. However, we show that with more than one instrument, this condition can only be satisfied if choice behavior is effectively homogeneous. Based on this finding, we consider the use of multiple IVs under a weaker, partial monotonicity condition. We characterize empirically verifiable sufficient and necessary conditions for the 2SLS estimand to be a positively weighted average of LATEs under partial monotonicity. We apply these results to an empirical analysis of the returns to college with multiple instruments. We show that the standard monotonicity condition is at odds with the data. Nevertheless, our empirical checks reveal that the 2SLS estimate retains a causal interpretation as a positively weighted average of the effects of college attendance among complier groups.publishedVersio
Two introduced species of Typhlocybinae (Hemiptera, Cicadellidae) new to Norway
This paper present two species of Typhlocybinae (Hemiptera, Cicadellidae) new to Norway, Zonocyba bifasciata (Boheman, 1852) and Zyginella pulchra Löw, 1885. Both species are reported from plant importers and from established populations in Norway. We argue that both species have been introduced into Norway as hitchhikers on garden plants, but that we cannot rule out the possibility of a simultaneously range expansion into Norway from Sweden.Two introduced species of Typhlocybinae (Hemiptera, Cicadellidae) new to NorwaypublishedVersio
Two introduced species of Typhlocybinae (Hemiptera, Cicadellidae) new to Norway
This paper present two species of Typhlocybinae (Hemiptera, Cicadellidae) new to Norway, Zonocyba bifasciata (Boheman, 1852) and Zyginella pulchra Löw, 1885. Both species are reported from plant importers and from established populations in Norway. We argue that both species have been introduced into Norway as hitchhikers on garden plants, but that we cannot rule out the possibility of a simultaneously range expansion into Norway from Sweden.publishedVersio
The Level 0 Trigger Decision Unit for the LHCb experiment
The Level 0 Decision Unit (L0DU) is one of the main components of the first trigger level (named level 0) of the LHCb experiment. This 16 layers custom board receives data from the calorimeter, muon and pile-up sub-triggers and computes the level 0 decision, reducing the rate from 40MHz to 1MHz. The processing is implemented in FPGA using a 40MHz synchronous pipelined architecture. The L0DU algorithm is fully configured via the Experiment Control System without any firmware reprogramming. An overall L0DU latency of less than 450ns has been achieved. The board was installed in the experimental area in April 2007 and since then has played a major role in the commissioning of the experiment
Diesel exhaust particles induce CYP1A1 and pro-inflammatory responses via differential pathways in human bronchial epithelial cells
<p>Abstract</p> <p>Background</p> <p>Exposure to diesel engine exhaust particles (DEPs) has been associated with several adverse health outcomes in which inflammation seems to play a key role. DEPs contain a range of different inorganic and organic compounds, including polycyclic aromatic hydrocarbons (PAHs). During the metabolic activation of PAHs, CYP1A1 enzymes are known to play a critical role. In the present study we investigated the potential of a characterised sample of DEPs to induce cytotoxicity, to influence the expression of CYP1A1 and inflammation-related genes, and to activate intracellular signalling pathways, in human bronchial epithelial cells. We specifically investigated to what extent DEP-induced expression of interleukin (IL)-6, IL-8 and cyclooxygenase (COX)-2 was regulated differentially from DEP-induced expression of CYP1A1.</p> <p>Results</p> <p>The cytotoxicity of the DEPs was characterised by a marked time- and concentration-dependent increase in necrotic cells at 4 h and above 200 ÎŒg/ml (~ 30 ÎŒg/cm<sup>2</sup>). DEP-induced DNA-damage was only apparent at high concentrations (â„ 200 ÎŒg/ml). IL-6, IL-8 and COX-2 were the three most up-regulated genes by the DEPs in a screening of 20 selected inflammation-related genes. DEP-induced expression of CYP1A1 was detected at very low concentrations (0.025 ÎŒg/ml), compared to the expression of IL-6, IL-8 and COX-2 (50-100 ÎŒg/ml). A CYP1A1 inhibitor (α-naphthoflavone), nearly abolished the DEP-induced expression of IL-8 and COX-2. Of the investigated mitogen-activated protein kinases (MAPKs), the DEPs induced activation of p38. A p38 inhibitor (SB202190) strongly reduced DEP-induced expression of IL-6, IL-8 and COX-2, but only moderately affected the expression of CYP1A1. The DEPs also activated the nuclear factor-ÎșB (NF-ÎșB) pathway, and suppression by siRNA tended to reduce the DEP-induced expression of IL-8 and COX-2, but not CYP1A1.</p> <p>Conclusion</p> <p>The present study indicates that DEPs induce both CYP1A1 and pro-inflammatory responses in vitro, but via differential intracellular pathways. DEP-induced pro-inflammatory responses seem to occur via activation of NF-ÎșB and p38 and are facilitated by CYP1A1. However, the DEP-induced CYP1A1 response does not seem to involve NF-ÎșB and p38 activation. Notably, the present study also indicates that expression of CYP1A1 may represent a particular sensitive biomarker of DEP-exposure.</p
Level 0 trigger decision unit for the LHCb experiment
The Level-0 Decision Unit (L0DU) is the central part of the first trigger level of the LHCb detector. The L0DU receives information from the Calorimeter, Muon and Pile-Up sub-triggers, with fixed latencies, at 40 MHz via 24 high speed optical fiber links running at 1.6 Gb/s. The L0DU performs simple physics algorithm to compute the decision in order to reduce the data flow down to 1 MHz for the next trigger level and a L0Block is constructed. The processing is implemented in FPGA using a 40 MHz synchronous pipelined architecture. The algorithm can be easily configured with the Experiment Control System (ECS) without FPGA reprogramming. The L0DU is a 16 layer custom board
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