Comparison of Engineering Wake Models with CFD Simulations

The engineering wake models by Jensen [1] and Frandsen et al. [2] are assessed for different scenarios simulated using Large Eddy Simulation and the Actuator Line method implemented in the Navier-Stokes equations. The scenarios include the far wake behind a single wind turbine, a long row of turbines in an atmospheric boundary layer, idealised cases of an infinitely long row of wind turbines and infinite wind farms with three different spacings. Both models include a wake expansion factor, which is calibrated to fit the simulated wake velocities. The analysis highlights physical deficiencies in the ability of the models to universally predict the wake velocities, as the expansion factor can be fitted for a given case, but with not apparent transition between the cases. 1

The mass and age of the first SONG target: the red giant 46 LMi

Context. The Stellar Observation Network Group (SONG) is an initiative to build a worldwide network of 1m telescopes with high-precision radial-velocity spectrographs. Here we analyse the first radial-velocity time series of a red-giant star measured by the SONG telescope at Tenerife. The asteroseismic results demonstrate a major increase in the achievable precision of the parameters for red-giant stars obtainable from ground-based observations. Reliable tests of the validity of these results are needed, however, before the accuracy of the parameters can be trusted. Aims. We analyse the first SONG time series for the star 46 LMi, which has a precise parallax and an angular diameter measured from interferometry, and therefore a good determination of the stellar radius. We use asteroseismic scaling relations to obtain an accurate mass, and modelling to determine the age. Methods. A 55-day time series of high-resolution, high S/N spectra were obtained with the first SONG telescope. We derive the asteroseismic parameters by analysing the power spectrum. To give a best guess on the large separation of modes in the power spectrum, we have applied a new method which uses the scaling of Kepler red-giant stars to 46 LMi. Results. Several methods have been applied: classical estimates, seismic methods using the observed time series, and model calculations to derive the fundamental parameters of 46 LMi. Parameters determined using the different methods are consistent within the uncertainties. We find the following values for the mass M (scaling), radius R (classical), age (modelling), and surface gravity (combining mass and radius): M = 1.09 ± 0.04 M⊙, R = 7.95 ± 0.11 R⊙ age t = 8.2 ± 1.9 Gy, and log g = 2.674 ± 0.013. Conclusions. The exciting possibilities for ground-based asteroseismology of solar-like oscillations with a fully robotic network have been illustrated with the results obtained from just a single site of the SONG network. The window function is still a severe problem which will be solved when there are more nodes in the network

Pharmacokinetics and pharmacodynamics of a 13-mer LNA-inhibitor-miR-221 in mice and non-human primates

Locked nucleic acid (LNA) oligonucleotides have been successfully used to efficiently inhibit endogenous small noncoding RNAs in vitro and in vivo. We previously demonstrated that the direct miR-221 inhibition by the novel 13-mer LNA-i-miR-221 induces significant antimyeloma activity and upregulates canonical miR-221 targets in vitro and in vivo. To evaluate the LNA-i-miR-221 pharmacokinetics and pharmacodynamics, novel assays for oligonucleotides quantification in NOD.SCID mice and Cynomolgus monkeys (Macaca fascicularis) plasma, urine and tissues were developed. To this aim, a liquid chromatography/mass spectrometry method, after solid-phase extraction, was used for the detection of LNA-i-miR-221 in plasma and urine, while a specific in situ hybridization assay for tissue uptake analysis was designed. Our analysis revealed short half-life, optimal tissue biovailability and minimal urine excretion of LNA-i-miR-221 in mice and monkeys. Up to 3 weeks, LNA-i-miR-221 was still detectable in mice vital organs and in xenografted tumors, together with p27 target upregulation. Importantly, no toxicity in the pilot monkey study was observed. Overall, our findings indicate the suitability of LNA-i-miR-221 for clinical use and we provide here pilot data for safety analysis and further development of LNA-miRNA-based therapeutics for human cancer