2,115 research outputs found
Bayesian quantification for coherent anti-Stokes Raman scattering spectroscopy
We propose a Bayesian statistical model for analyzing coherent anti-Stokes
Raman scattering (CARS) spectra. Our quantitative analysis includes statistical
estimation of constituent line-shape parameters, underlying Raman signal,
error-corrected CARS spectrum, and the measured CARS spectrum. As such, this
work enables extensive uncertainty quantification in the context of CARS
spectroscopy. Furthermore, we present an unsupervised method for improving
spectral resolution of Raman-like spectra requiring little to no \textit{a
priori} information. Finally, the recently-proposed wavelet prism method for
correcting the experimental artefacts in CARS is enhanced by using
interpolation techniques for wavelets. The method is validated using CARS
spectra of adenosine mono-, di-, and triphosphate in water, as well as,
equimolar aqueous solutions of D-fructose, D-glucose, and their disaccharide
combination sucrose
Characterization of Thin p-on-p Radiation Detectors with Active Edges
Active edge p-on-p silicon pixel detectors with thickness of 100 m were
fabricated on 150 mm Float zone silicon wafers at VTT. By combining measured
results and TCAD simulations, a detailed study of electric field distributions
and charge collection performances as a function of applied voltage in a p-on-p
detector was carried out. A comparison with the results of a more conventional
active edge p-on-n pixel sensor is presented. The results from 3D spatial
mapping show that at pixel-to-edge distances less than 100 m the sensitive
volume is extended to the physical edge of the detector when the applied
voltage is above full depletion. The results from a spectroscopic measurement
demonstrate a good functionality of the edge pixels. The interpixel isolation
above full depletion and the breakdown voltage were found to be equal to the
p-on-n sensor while lower charge collection was observed in the p-on-p pixel
sensor below 80 V. Simulations indicated this to be partly a result of a more
favourable weighting field in the p-on-n sensor and partly of lower hole
lifetimes in the p-bulk.Comment: 23 pages, 16 figures, 1 tabl
Open system dynamics with non-Markovian quantum jumps
We discuss in detail how non-Markovian open system dynamics can be described
in terms of quantum jumps [J. Piilo et al., Phys. Rev. Lett. 100, 180402
(2008)]. Our results demonstrate that it is possible to have a jump description
contained in the physical Hilbert space of the reduced system. The developed
non-Markovian quantum jump (NMQJ) approach is a generalization of the Markovian
Monte Carlo Wave Function (MCWF) method into the non-Markovian regime. The
method conserves both the probabilities in the density matrix and the norms of
the state vectors exactly, and sheds new light on non-Markovian dynamics. The
dynamics of the pure state ensemble illustrates how local-in-time master
equation can describe memory effects and how the current state of the system
carries information on its earlier state. Our approach solves the problem of
negative jump probabilities of the Markovian MCWF method in the non-Markovian
regime by defining the corresponding jump process with positive probability.
The results demonstrate that in the theoretical description of non-Markovian
open systems, there occurs quantum jumps which recreate seemingly lost
superpositions due to the memory.Comment: 19 pages, 10 figures. V2: Published version. Discussion section
shortened and some other minor changes according to the referee's suggestion
Evaluation of a coupled dispersion and aerosol process model against measurements near a major road
International audienceA field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17?20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm?10 ?m (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3?50 nm (mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible at this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic vapour of 1012 molecules cm?3 was shown to be in a disagreement with the measured particle size evolution, while the modelling runs with the concentration of condensable organic vapour of 109?1010 molecules cm?3 resulted in particle sizes that were closest to the measured values
FGF8 (fibroblast growth factor 8 (androgen-induced))
Review on FGF8 (fibroblast growth factor 8 (androgen-induced)), with data on DNA, on the protein encoded, and where the gene is implicated
Postrelease exploration and diel activity of hatchery, wild, and hybrid strain brown trout in seminatural streams
Behaviour that is adaptive in captivity may be maladaptive in the wild and compromise postrelease survival of hatchery fish. The understanding of behavioural variation displayed immediately after release could help to improve hatchery protocols and development of behavioural tests for assessing the fitness of fish reared for releases. We characterized the postrelease behaviour of common-garden-raised offspring of wild resident, captive-bred migratory, and hybrid brown trout (Salmo trutta) in two experiments: in small artificial channels and in high and low densities in seminatural streams. The results from seminatural streams showed that hatchery fish were more likely to disperse downstream from the initial stocking site compared with hybrid and wild strain fish. The small-scale experiment did not reveal this ecologically pivotal difference in postrelease performance among strains, and individual responses were inconsistent between the experiments. Circadian activity patterns did not differ among strains. These detailed observations of postrelease behaviour reveal important intrinsic differences in dispersal traits among brown trout strains and suggest that selective breeding and crossbreeding can substantially affect these traits.Peer reviewe
Probiotic intervention in infancy is not associated with development of beta cell autoimmunity and type 1 diabetes
Non peer reviewe
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