Ferromagnetic phase transition in a Heisenberg fluid: Monte Carlo simulations and Fisher corrections to scaling

The magnetic phase transition in a Heisenberg fluid is studied by means of the finite size scaling (FSS) technique. We find that even for larger systems, considered in an ensemble with fixed density, the critical exponents show deviations from the expected lattice values similar to those obtained previously. This puzzle is clarified by proving the importance of the leading correction to the scaling that appears due to Fisher renormalization with the critical exponent equal to the absolute value of the specific heat exponent $\alpha$. The appearance of such new corrections to scaling is a general feature of systems with constraints.Comment: 12 pages, 2 figures; submitted to Phys. Rev. Let

Commissioning of the CALIFA Barrel Calorimeter of the R3^{3}B Experiment at FAIR

CALIFA is the high efficiency and energy resolution calorimeter for the R$^{3}$B experiment at FAIR, intended for detecting high energy charged particles and $\gamma$-rays in inverse kinematics direct reactions. It surrounds the reaction target in a segmented configuration of Barrel and Forward End-Cap pieces. The CALIFA Barrel consists of 1952 detection units made of CsI(Tl) long-shaped scintillator crystals, and it is being commissioned during the Phase0 experiments at FAIR. The first setup for the CALIFA Barrel commissioning is presented here. Results of detector performance with $\gamma$-rays are obtained, and show that the system fulfills the design requirements

Dendritic cells delivered inside human carcinomas are sequestered by interleukin-8

In the course of a clinical trial consisting of intratumoral injections of dendritic cells (DCs) transfected to produce interleukin-12, the use of (111)In-labeled tracing doses of DCs showed that most DCs remained inside tumor tissue, instead of migrating out. In search for factors that could explain this retention, it was found that tumors from patients suffering hepatocellular carcinoma, colorectal or pancreatic cancer were producing IL-8 and that this chemokine attracted monocyte-derived dendritic cells that uniformly express both IL-8 receptors CXCR1 and CXCR2. Accordingly, neutralizing antihuman IL-8 monoclonal antibodies blocked the chemotactic attraction of DCs by recombinant IL-8, as well as by the serum of the patients or culture supernatants of human colorectal carcinomas. In addition, tissue culture supernatants of colon carcinoma cells inhibited DC migration induced by MIP-3beta in an IL-8-dependent fashion. IL-8 production in malignant tissue and the responsiveness of DCs to IL-8 are a likely explanation of the clinical images, which suggest retention of DCs inside human malignant lesions. Impairment of DC migration toward lymphoid tissue could be involved in cancer immune evasion

Properties of the CsI(Tl) detector elements of the CALIFA detector

In the R3B experiment at FAIR, charged particles with energies up to 600 MeV and forward boosted γ-rays with energies up to 20 MeV need to be detected in scattering experiments. Calorimeters for nuclear physics experiments of this kind, using relativistic radioactive ion beams, require high energy resolution and high efficiency for simultaneous detection of strongly Doppler shifted γ-rays and high-energy charged particles. A calorimeter design that can meet these requirements, using CsI(Tl) scintillators, results in detector elements that may exhibit light output variations with crystal depth, which can limit the attainable resolution. In this paper we present results from a systematic study of 478 detector modules of CALIFA, the R3B calorimeter, in order to determine and minimize such variations. To facilitate further systematic studies we also present results for the total absorption length of the scintillation light, using spectrophotometry, light crosstalk between adjacent detector modules, and surface topography of the CsI(Tl) crystals from atomic force microscopy.Swedish research council | Ref. 2017-03986Swedish research council | Ref. 2014-06644Swedish research council | Ref. 2013-04178Swedish research council | Ref. 2012-04550BMBF, Alemania | Ref. 05P15WOFNABMBF, Alemania | Ref. 05P19WOFN1BMBF, Alemania | Ref. 05P15RDFN1BMBF, Alemania | Ref. 05P19RDFN