Thermal Dileptons from Hot and Dense Strongly Interacting Matter

The NA60 experiment at the CERN SPS has studied muon-pair production in 158A GeV In-In collisions. The unprecedented precision of the data has allowed to isolate a strong excess of pairs above the known sources in the whole invariant mass region 0.2<M<2.6 GeV. The (mostly) Planck-like shape of the mass spectra, exponential m_T spectra, zero polarization and the general agreement with thermal-model results allow for a consistent interpretation of the excess dimuons as thermal radiation from a randomized system. For M<1 GeV, the process pi+pi- -> rho -> mu+mu- dominates. The associated space-time averaged rho spectral function shows a nearly diverging width in approaching chiral symmetry restoration, but essentially no shift in mass. Some in-medium effects are also seen for the omega, but not for the phi. For M>1 GeV, the average temperature associated with the mass spectrum is about 200 MeV, considerably above T_c=170 MeV, implying a transition to dominantly partonic emission sources in this region. The transition itself is mirrored by a large jump-like drop in the inverse slope of the transverse mass spectra around 1 GeV.Comment: 10 pages, 6 figures, Proceedings of Chiral 2010 (Valencia, June 21-24, 2010

Experimental Conference Summary

Experimental summary talk given at International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (QM2001), Stony Brook, New York, 15-20 Jan 2001.Comment: Proceedings of a summary talk given at International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (QM2001), Stony Brook, New York, 15-20 Jan 200

Differential Activation of CD8+ Tumor-Specific Tc1 and Tc2 Cells by an IL-10-Producing Murine Plasmacytoma

The involvement of counteractive CD8+ T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model. CD8+ Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cells in vivo and in vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumorinduced CD8+ T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-γ as a suppressive factor. Whereas most longterm cultivated CD8+ ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primary in vitro Tc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10. CD8+ Tc cells that are induced in a primary MLTC do not produce IFN-γ, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-γ or IL-12. In contrast, ADJ-PC- 5-specific CD8+ Tc cells from immunized mice are IFN-γ producing Tc1 cells. Since the primary in vitro Tc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-γ these Tc1 cells behave similar to the suppressive CD8+ T cells that are induced during early stages of ADJ-PC-5 tumorigenesis

Functional-structural reorganisation of the neuronal network for auditory perception in subjects with unilateral hearing loss: Review of neuroimaging studies.

This paper aims to provide a review of studies using neuroimaging to measure functional-structural reorganisation of the neuronal network for auditory perception after unilateral hearing loss

Lepton-pair production in nuclear collisions - past, present, future

The key results on lepton-pair production in ultra-relativistic nuclear collisions are shortly reviewed, starting at the roots of pp collisions in the seventies, and ending at the perspectives of the colliders RHIC and LHC. The presence is dominated by the recent precision results from NA60 at the CERN SPS, culminating in the first measurement of the in-medium rho spectral function and the transverse flow of the associated thermal radiation. The seeming cut-off of the flow above the rho may well be the first direct hint for thermal radiation of partonic origin in nuclear collisions. The major milestones in the theoretical developments are also covered.Comment: Invited talk at INPC07, Tokyo, June 3-8, 200

Rationality of quotients by linear actions of affine groups

Let G be the (special) affine group, semidirect product of SL_n and C^n. In this paper we study the representation theory of G and in particular the question of rationality for V/G where V is a generically free G-representation. We show that the answer to this question is positive if the dimension of V is sufficiently large and V is indecomposable. We have a more precise theorem if V is a two-step extension 0 -> S -> V -> Q -> 0 with S, Q completely reducible.Comment: 18 pages; dedicated to Fabrizio Catanese on the occasion of his 60th birthda

Grenzen und Gespinste

Mit Beiträgen von: Mischa Leinkauf, Hans Ulrich Reck, Konstantin Butz, Daniel Burkhardt, Hanns-Josef Ortheil, Dirk Specht, Christina Möser, Karin Lingnau, Elisa Balmaced

Microbubble Composition and Preparation for High-Frequency Contrast-Enhanced Ultrasound Imaging: In Vitro and in Vivo Evaluation

Although high-frequency ultrasound imaging is gaining attention in various applications, hardly any ultrasound contrast agents (UCAs) dedicated to such frequencies (>15 MHz) are available for contrast-enhanced ultrasound (CEUS) imaging. Moreover, the composition of the limited commercially available UCAs for high-frequency CEUS (hfCEUS) is largely unknown, while shell properties have been shown to be an important factor for their performance. The aim of our study was to produce UCAs in-house for hfCEUS. Twelve different UCA formulations A-L were made by either sonication or mechanical agitation. The gas core consisted of C4F10 and the main coating lipid was either 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC; A-F formulation) or 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC; G-L formulation). Mechanical agitation r

Assessing causes of yield gaps in agricultural areas with diversity in climate and soils

Identification of causes of gaps between yield potential and producer yields has been restricted to small geographic areas. In the present study, we developed a novel approach for identifying causes of yield gaps over large agricultural areas with diversity in climate and soils. This approach was applied to quantify and explain yield gaps in rainfed and irrigated soybean in the North-Central USA (NC USA) region, which accounts for about one third of soybean global production. Survey data on yield and management were collected from 3568 producer fields over two crop seasons and grouped into 10 technology extrapolation domains (TEDs) according to their soil, climate, and water regime. Yield potential was estimated using a combination of crop modeling and boundary functions for water productivity and compared against highest producer yields derived from the yield distribution in each TED-year. Yield gaps were calculated as the difference between yield potential and average producer yield. Explanatory factors for yield gaps were investigated by identifying management practices that were concordantly associated with high- and low-yield fields. Management × TED interactions were then evaluated to elucidate the underlying causes of yield gaps. The chosen spatial TED framework accounted for about half of the regional variation in producer yield within the NC USA region. Across the 10 TEDs, soybean average yield potential ranged from 3.3 to 5.3 Mg ha−1 for rainfed fields and from 5.3 to 5.6 Mg ha−1for irrigated fields. Highest producer yields in each TED were similar (±12%) to the estimated yield potential. Yield gap, calculated as percentage of yield potential, was larger in rainfed (range: 15–28%) than in irrigated (range: 11–16%) soybean. Upscaled to the NC USA region, yield potential was 4.8 Mg ha−1 (rainfed) and 5.7 Mg ha−1 (irrigated), with a respective yield gap of 22 and 13% of yield potential. Sowing date, tillage, and in-season foliar fungicide and/or insecticide were identified as explanatory causes for yield variation in half or more of the 10 TEDs. However, the degree to which these three factors influenced producer yield varied across TEDs. Analysis of in-season weather helped interpret management × TED interactions. For example, yield increase due to advances in sowing date was greater in TEDs with less water limitation during the pod-setting phase. The present study highlights the strength of combining producer survey data with a spatial framework to measure yield gaps, identify management factors explaining these gaps, and understand the biophysical drivers influencing yield responses to crop management