Lasing at the band edges of plasmonic lattices

We report room temperature lasing in two-dimensional diffractive lattices of silver and gold plasmon particle arrays embedded in a dye-doped polymer that acts both as waveguide and gain medium. As compared to conventional dielectric distributed feedback lasers, a central question is how the underlying band structure from which lasing emerges is modified by both the much stronger scattering and the disadvantageous loss of metal. We use spectrally resolved back-focal plane imaging to measure the wavelength- and angle dependence of emission below and above threshold, thereby mapping the band structure. We find that for silver particles, the band structure is strongly modified compared to dielectric reference DFB lasers, since the strong scattering gives large stop gaps. In contrast, gold particles scatter weakly and absorb strongly, so that thresholds are higher, but the band structure is not strongly modified. The experimental findings are supported by finite element and fourier modal method calculations of the single particle scattering strength and lattice extinction.Comment: 10 pages, 8 figure

Jejunal gene expression patterns correlate with severity of systemic infection in chicken

<p>Abstract</p> <p>Background</p> <p>Not much is known about the effect of <it>Salmonella enteritidis</it> on changes in the developmental processes occurring in the intestine of young chicken. Therefore we investigated the correlation of intestinal gene expression patterns with the severity of systemic Salmonella infections.</p> <p>Methods</p> <p>The number of Salmonella colony forming units (CFUs) in the liver of infected chicken were plotted against the average intestinal expression profiles of previously identified gene expression clusters. The functional properties of all the genes taken together present in 3 clusters exhibiting positive correlation at early time-points were compared with the functional properties of the genes displaying antagonistic correlations in 1 cluster. The top 5 ranking functional groups were analysed in further detail.</p> <p>Results</p> <p>Three clusters showed gene expression profiles which were positively correlated with the severity of systemic disease as measured by the number of Salmonella colony forming units in the liver. In these clusters, genes involved in morphological processes were predominantly present. One cluster had a profile that was negatively correlated with the severity of systemic disease, as measured by numbers of CFUs in the liver. The genes in the latter cluster were mostly involved in cell turn-over and metabolism.</p> <p>Conclusions</p> <p>In the developing jejunum of young chicken, both stimulatory and inhibitory gene expression mechanisms are correlated with the severity of systemic Salmonella infections.</p

The 'Iron Cage' strengthened? Discretion and digital discipline

Research on changes in public administration associated with the adoption and use of information and communication technologies ('informatization'), almost univocally supports the conclusion that shop floor discretion disappears under their influence. We, however, are ill at ease with this direction in thought about discretion. Our unease is based on the scholarly work about practices, organizational learning and responsiveness. In this article, we test the thesis on the relation between informatization and operational discretion in an empirical research of operational discretion and informatization in two Dutch public agencies, both large and both automated. Our findings show that informatization does not destroy operational discretion, but rather obscures discretion. Based on the work of Argyris, we show that the phenomenon at work is 'participatory boundary practices', the direct personal ties that keep an organization together. ICTs destroy such links and thereby affect organizational learning. © Blackwell Publishing Ltd. 2007

LHC Transverse Feedback System and its Hardware Commissioning

A powerful transverse feedback system ("Damper") has been installed in LHC. It will stabilise coupled bunch instabilities in a frequency range from 3 kHz to 20 MHz and at the same time damp injection oscillations originating from steering errors and injection kicker ripple. The transverse damper can also be used as an exciter for purposes of abort gap cleaning or tune measurement. The power and lowlevel systems layouts are described along with results from the hardware commissioning. The achieved performance is compared with earlier predictions and requirements for injection damping and instability control

LHC Transverse Feedback System: First Results of Commissionning

A powerful transverse feedback system ("Damper") has been installed in LHC. It will stabilise the high intensity beam against coupled bunch transverse instabilities in a frequency range from 3 kHz to 20 MHz and at the same time damp injection oscillations originating from steering errors and injection kicker ripple. The LHC Damper can also be used as means of exciting transverse oscillations for the purposes of abort gap cleaning and tune measurement. The LHC Damper includes 4 feedback systems on 2 circulating beams (in other words one feedback system per beam and plane). Every feedback system consists of 4 electrostatic kickers, 4 push-pull wide band power amplifiers, 8 preamplifiers, two digital processing units and 2 beam position monitors with low-level electronics. The power and low-level subsystem layout is described along with first results from the commissioning of 16 power amplifiers and 16 electrostatic kickers located in the LHC tunnel. The achieved performance is compared with earlier predictions and requirements for injection damping and instability control. Requirements and first measurements of the performance of the power and low-level subsystems are summarized

3D urban subsurface modelling and visualisation : a review of good practices and techniques to ensure optimal use of geological information in urban planning

This report is the result of COST Action TU1206 Working Group 2, Work package 2.3, and focusses on 3D urban subsurface modelling and visualisation. The major aims of this report are: 1) evaluating current techniques and identify good practices / best efforts in 3D geological modelling and visualisation of the urban subsurface, based on case studies, and 2) co-developing (subsurface specialists & model users) requirements for optimal use of 3D geological modelling information in specific planning and policy contexts. Three major topics have been considered: • Constructing and maintaining 3D urban geological models • Modelling man-made ground • Visualising 3D urban subsurface model results To improve the use of subsurface modelling in urban planning in the future, the following challenges have been identified: • The complexity of the urban subsurface, including man-made ground, combined with the level of detail of information asked for in many urban planning issues demand that geologists look beyond their traditional data sources. • Combined 3D property modelling of the small-scale heterogeneity of man-made deposits and natural deposits requires new modelling approaches. • Management of the shallow urban subsurface requires model tools that can be frequently updated to reflect the frequently changing properties and functions of the urban subsurface. • There is a need for dynamic (4D) urban subsurface models that can be used for real-time monitoring and incorporation of time-series data on subsurface properties. • It would be cost-effective to have an actively maintained, scalable geological framework model of a city available that forms a common basis for the various kinds of dedicated models of parts of the city. • To give subsurface information a firm position in urban planning and management, geological information will have to be presented in the right format, and at the right time. It is absolutely necessary to include the subsurface infrastructure and to combine the model with above-ground information

Re-integratie in BOLD Cities: Wat zijn de kansen, risico’s en (on)mogelijkheden in het gebruik van big data om de effectiviteit en kwaliteit van gemeentelijke re-integratie te verbeteren? [Eindrapportage]

Hervorming Sociale Regelgevin

Improving metabolic stability of fluorine-18 labeled verapamil analogs

INTRODUCTION: Fluorine-18 labeled positron emission tomography (PET) tracers were developed to obtain more insight into the function of P-glycoprotein (P-gp) in relation to various conditions. They allow research in facilities without a cyclotron as they can be transported with a half-life of 110 min. As the metabolic stability of previously reported tracers [18F]1 and [18F]2 was poor, the purpose of this study was to improve this stability using deuterium substitution, creating verapamil analogs [18F]1-d4, [18F]2-d4, [18F]3-d3 and [18F]3-d7. METHODS: The following deuterium containing tracers were synthesized and evaluated in mice and rats: [18F]1-d4, [18F]2-d4, [18F]3-d3 and [18F]3-d7. RESULTS: The deuterated analogs [18F]2-d4, [18F]3-d3 and [18F]3-d7 showed increased metabolic stability compared with their non-deuterated counterparts. The increased metabolic stability of the methyl containing analogs [18F]3-d3 and [18F]3-d7 might be caused by steric hindrance for enzymes. CONCLUSION: The striking similar in vivo behavior of [18F]3-d7 to that of (R)-[11C]verapamil, and its improved metabolic stability compared with the other fluorine-18 labeled tracers synthesized, supports the potential clinical translation of [18F]3-d7 as a PET radiopharmaceutical for P-gp evaluation