Atmospheric variability and air-sea interaction

The topics studied include: (1) processing of Northern Hemispheric precipitation data, in order to fill in the transition seasons to provide a continuous 40 year data base on the variability of continental precipitation; (2) comparison of seasonally averaged fields of sea surface temperature obtained from ship observations in the North Atlantic and North Pacific in 1970 with the corresponding fields inferred from satellite observations; (3) estimation of seasonal average of total precipitable water at those admittedly few oceanic stations where repeated vertical soundings were made in 1970 and comparison with corresponding values inferred from satellite measurements; (4) comparison of seasonally averaged evaporation fields determined from ground based observations in 1970 with the field of divergence of the seasonal total horizontal water vapor flux inferred from satellite total water measurements and NMC wind data for the lower troposphere; (5) examination of meaning of convection-inversion index

A Method for Determining Optimum Re-entry Trajectories

Determining optimum atmospheric reentry trajectories using Pontryagin maximum principl

On the Observation of Phase Transitions in Collisions of Elementary Matter

We investigate the excitation function of directed flow, which can provide a clear signature of the creation of the QGP and demonstrate that the minimum of the directed flow does not correspond to the softest point of the EoS for isentropic expansion. A novel technique measuring the compactness is introduced to determine the QGP transition in relativistic-heavy ion collisions: The QGP transition will lead to higher compression and therefore to higher compactness of the source in coordinate space. This effect can be observed by pion interferometry. We propose to measure the compactness of the source in the appropriate principal axis frame of the compactness tensor in coordinate space.Comment: LaTeX, 8 pages, 6 figures, Conference proceedings to CRIS 2000, 3rd Catania Relativistic Ion Studie

Alternative antibody for the detection of CA19-9 antigen: a European multicenter study for the evaluation of the analytical and clinical performance of the Access (R) GI Monitor assay on the UniCel (R) Dxl 800 Immunoassay System

Background: Gastrointestinal cancer antigen CA19-9 is known as a valuable marker for the management of patients with pancreatic cancer. Methods: The analytical and clinical performance of the Access(R) GI Monitor assay (Beckman Coulter) was evaluated on the UniCel(R) Dxl 800 Immunoassay System at five different European sites and compared with a reference method, defined as CA19-9 on the Elecsys System (Roche Diagnostics). Results: Total imprecision (%CV) of the GI Monitor ranged between 3.4% and 7.7%, and inter-laboratory reproducibility between 3.6% and 4.0%. Linearity upon dilution showed a mean recovery of 97.4% (SD+7.2%). Endogenous interferents had no influence on GI Monitor levels (mean recoveries: hemoglobin 103%, bilirubin 106%, triglycerides 106%). There was no high-dose hook effect up to 115,000 kU/L. Clinical performance investigated in sera from 1811 individuals showed a good correlation between the Access' GI Monitor and Elecsys CA19-9 (R = 0.959, slope = 1.004, intercept +0.17). GI Monitor serum levels were low in healthy individuals (n = 267, median = 6.0 kU/L, 95th percentile = 23.1 kU/L), higher in individuals with various benign diseases (n = 550, medians = 5.8-13.4 kU/L, 95th percentiles = 30.1-195.5 kU/L) and even higher in individuals suffering from various cancers (n = 995, medians = 8.4-233.8 kU/L, 95th percentiles = 53.7-13,902 kU/L). Optimal diagnostic accuracy for cancer detection against the relevant benign control group by the GI Monitor was found for pancreatic cancer {[}area under the curve (AUC) 0.83]. Results for the reference CA19-9 assay were comparable (AUC 0.85). Conclusions: The Access(R) GI Monitor provides very good methodological characteristics and demonstrates an excellent analytical and clinical correlation with the Elecsys CA19-9. The GI Monitor shows the best diagnostic accuracy in pancreatic cancer. Our results also suggest a clinical value of the GI Monitor in other cancers

Entropy Production in Collisions of Relativistic Heavy Ions -- a signal for Quark-Gluon Plasma phase transition?

Entropy production in the compression stage of heavy ion collisions is discussed within three distinct macroscopic models (i.e. generalized RHTA, geometrical overlap model and three-fluid hydrodynamics). We find that within these models \sim 80% or more of the experimentally observed final-state entropy is created in the early stage. It is thus likely followed by a nearly isentropic expansion. We employ an equation of state with a first-order phase transition. For low net baryon density, the entropy density exhibits a jump at the phase boundary. However, the excitation function of the specific entropy per net baryon, S/A, does not reflect this jump. This is due to the fact that for final states (of the compression) in the mixed phase, the baryon density \rho_B increases with \sqrt{s}, but not the temperature T. Calculations within the three-fluid model show that a large fraction of the entropy is produced by nuclear shockwaves in the projectile and target. With increasing beam energy, this fraction of S/A decreases. At \sqrt{s}=20 AGeV it is on the order of the entropy of the newly produced particles around midrapidity. Hadron ratios are calculated for the entropy values produced initially at beam energies from 2 to 200 AGeV.Comment: 17 pages, 8 figures, uses epsfig.sty; Submitted to Nucl.Phys.