Critical behavior of weakly-disordered anisotropic systems in two dimensions

The critical behavior of two-dimensional (2D) anisotropic systems with weak quenched disorder described by the so-called generalized Ashkin-Teller model (GATM) is studied. In the critical region this model is shown to be described by a multifermion field theory similar to the Gross-Neveu model with a few independent quartic coupling constants. Renormalization group calculations are used to obtain the temperature dependence near the critical point of some thermodynamic quantities and the large distance behavior of the two-spin correlation function. The equation of state at criticality is also obtained in this framework. We find that random models described by the GATM belong to the same universality class as that of the two-dimensional Ising model. The critical exponent $\nu$ of the correlation length for the 3- and 4-state random-bond Potts models is also calculated in a 3-loop approximation. We show that this exponent is given by an apparently convergent series in $\epsilon=c-\frac{1}{2}$ (with $c$ the central charge of the Potts model) and that the numerical values of $\nu$ are very close to that of the 2D Ising model. This work therefore supports the conjecture (valid only approximately for the 3- and 4-state Potts models) of a superuniversality for the 2D disordered models with discrete symmetries.Comment: REVTeX, 24 pages, to appear in Phys.Rev.

Magnetic critical behavior of two-dimensional random-bond Potts ferromagnets in confined geometries

We present a numerical study of 2D random-bond Potts ferromagnets. The model is studied both below and above the critical value $Q_c=4$ which discriminates between second and first-order transitions in the pure system. Two geometries are considered, namely cylinders and square-shaped systems, and the critical behavior is investigated through conformal invariance techniques which were recently shown to be valid, even in the randomness-induced second-order phase transition regime Q>4. In the cylinder geometry, connectivity transfer matrix calculations provide a simple test to find the range of disorder amplitudes which is characteristic of the disordered fixed point. The scaling dimensions then follow from the exponential decay of correlations along the strip. Monte Carlo simulations of spin systems on the other hand are generally performed on systems of rectangular shape on the square lattice, but the data are then perturbed by strong surface effects. The conformal mapping of a semi-infinite system inside a square enables us to take into account boundary effects explicitly and leads to an accurate determination of the scaling dimensions. The techniques are applied to different values of Q in the range 3-64.Comment: LaTeX2e file with Revtex, revised versio

Fairy tale tourism: the architectural projection mapping of magically real and irreal festival lightscapes

This paper explores how established light festivals such as the Fête des Lumières in Lyon and Lumiere in Durham were first conceived by Robert-Houdin as illusory illuminations in the Loire in the 1950s. The research investigates the concept of spectacles as inversions of reality; re-situating light works within authenticity theory by exploring their manipulation of magical reality and irreality. The research uses the authors’ experience of event design to assess different interactions of light with the tri-dimensional architectural canvas, suggesting three classifications of animated projection mapping events: architecturally passive, architecturally physically active and architecturally metaphysically active. Each category has implications for how spectators perceive these installations. Architecturally passive events may use fairy tale content, evoking atavistic and affective responses, the ‘skinning’ of buildings with magical reality is designed to evoke perceptual duality, and the wobbling unfolding of irreality may ultimately create a state of ‘illuminated flow.

A functional AT/G polymorphism in the 5'-untranslated region (UTR) of SETDB2 in the IgE locus on human chromosome 13q14

The immunoglobulin E (IgE)-associated locus on human chromosome 13q14 influencing asthma-related traits contains the genes PHF11 and SETDB2. SETDB2 is located in the same linkage disequilibrium region as PHF11 and polymorphisms within SETDB2 have been shown to associate with total serum IgE levels. In this report, we sequenced the 15 exons of SETDB2 and identified a single previously ungenotyped mutation (AT/G, rs386770867) in the 5′-untranslated region of the gene. The polymorphism was found to be significantly associated with serum IgE levels in our asthma cohort (P=0.0012). Electrophoretic mobility shift assays revealed that the transcription factor Ying Yang 1 binds to the AT allele, whereas SRY (Sex determining Region Y) binds to the G allele. Allele-specific transcription analysis (allelotyping) was performed in 35 individuals heterozygous for rs386770867 from a panel of 200 British families ascertained through probands with severe stage 3 asthma. The AT allele was found to be significantly overexpressed in these individuals (P=1.26 × 10(−21)). A dual-luciferase assay with the pGL3 luciferase reporter gene showed that the AT allele significantly affects transcriptional activities. Our results indicate that the IgE-associated AT/G polymorphism (rs386770867) regulates transcription of SETDB2

Use of Aspirin postdiagnosis improves survival for colon cancer patients

Background: The preventive role of non-steroid anti-inflammatory drugs (NSAIDs) and aspirin, in particular, on colorectal cancer is well established. More recently, it has been suggested that aspirin may also have a therapeutic role. Aim of the present observational population-based study was to assess the therapeutic effect on overall survival of aspirin/NSAIDs as adjuvant treatment used after the diagnosis of colorectal cancer patients. Methods: Data concerning prescriptions were obtained from PHARMO record linkage systems and all patients diagnosed with colorectal cancer (1998-2007) were selected from the Eindhoven Cancer Registry (population-based cancer registry). Aspirin/NSAID use was classified as none, prediagnosis and postdiagnosis and only postdiagnosis. Patients were defined as non-user of aspirin/NSAIDs from the date of diagnosis of the colorectal cancer to the date of first use of aspirin or NSAIDs and user from first use to the end of follow-up. Poisson regression was performed with user status as time-varying exposure.Results:In total, 1176 (26%) patients were non-users, 2086 (47%) were prediagnosis and postdiagnosis users and 1219 (27%) were only postdiagnosis users (total n=4481). Compared with non-users, a survival gain was observed for aspirin users; the adjusted rate ratio (RR) was 0.77 (95% confidence interval (CI) 0.63-0.95; P=0.015). Stratified for colon and rectal, the survival gain was only present in colon cancer (adjusted RR 0.65 (95%CI 0.50-0.84; P=0.001)). For frequent users survival gain was larger (adjusted RR 0.61 (95%CI 0.46-0.81; P=0.001). In rectal cancer, aspirin use was not associated with survival (adjusted RR 1.10 (95%CI 0.79-1.54; P=0.6). The NSAIDs use was associated with decreased survival (adjusted RR 1.93 (95%CI 1.70-2.20; P<0.001). Conclusion: Aspirin use initiated or continued after diagnosis of colon cancer is associated with a lower risk of overall mortality. These findings strongly support initiation of a placebo-controlled trial that investigates the role of aspirin as adjuvant treatment in colon cancer patients

Three-Dimensional, Tomographic Super-Resolution Fluorescence Imaging of Serially Sectioned Thick Samples

Three-dimensional fluorescence imaging of thick tissue samples with near-molecular resolution remains a fundamental challenge in the life sciences. To tackle this, we developed tomoSTORM, an approach combining single-molecule localization-based super-resolution microscopy with array tomography of structurally intact brain tissue. Consecutive sections organized in a ribbon were serially imaged with a lateral resolution of 28 nm and an axial resolution of 40 nm in tissue volumes of up to 50 µm×50 µm×2.5 µm. Using targeted expression of membrane bound (m)GFP and immunohistochemistry at the calyx of Held, a model synapse for central glutamatergic neurotransmission, we delineated the course of the membrane and fine-structure of mitochondria. This method allows multiplexed super-resolution imaging in large tissue volumes with a resolution three orders of magnitude better than confocal microscopy

Aspirin induces cell death and caspase-dependent phosphatidylserine externalization in HT-29 human colon adenocarcinoma cells

The induction of cell death by aspirin was analysed in HT-29 colon carcinoma cells. Aspirin induced two hallmarks of apoptosis: nuclear chromatin condensation and increase in phosphatidylserine externalization. However, aspirin did not induce either oligonucleosomal fragmentation of DNA, decrease in DNA content or nuclear fragmentation. The effect of aspirin on Annexin V binding was inhibited by the caspase inhibitor Z-VAD.fmk, indicating the involvement of caspases in the apoptotic action of aspirin. However, aspirin did not induce proteolysis of PARP, suggesting that aspirin does not increase nuclear caspase 3-like activity in HT-29 cells. This finding may be related with the ‘atypical’ features of aspirin-induced apoptosis in HT-29 cells. © 1999 Cancer Research Campaig

The cytotoxicity and synergistic potential of aspirin and aspirin analogues towards oesophageal and colorectal cancer

Background: Oesophageal cancer (OC) is a deadly cancer because of its aggressive nature with survival rates that have barely improved in decades. Epidemiologic studies have shown that low-dose daily intake of aspirin can decrease the incidence of OC. Methods: The toxicity of aspirin and aspirin derivatives to OC and a colorectal cancer (CRC) cell line were investigated in the presence and absence of platins. Results: The data in this study show the effects of a number of aspirin analogues and aspirin on OC cell lines that originally presented as squamous cell carcinoma (SSC) and adenocarcinoma (ADC). The aspirin analogues fumaryldiaspirin (PN517) and the benzoylsalicylates (PN524, PN528 and PN529), were observed to be more toxic against the OC cell lines than aspirin. Both quantitative and qualitative apoptosis experiments reveal that these compounds largely induce apoptosis, although some necrosis was evident with PN528 and PN529. Failure to recover following the treatment with these analogues emphasized that these drugs are largely cytotoxic in nature. The OE21 (SSC) and OE33 (ADC) cell lines were more sensitive to the aspirin analogues compared to the Flo-1 cell line (ADC). A non-cancerous oesophageal primary cells NOK2101, was used to determine the specificity of the aspirin analogues and cytotoxicity assays revealed that analogues PN528 and PN529 were selectively toxic to cancer cell lines, whereas PN508, PN517 and PN524 also induced cell death in NOK2101. In combination index testing synergistic interactions of the most promising compounds, including aspirin, with cisplatin, oxaliplatin and carboplatin against the OE33 cell line and the SW480 CRC cell line were investigated. Compounds PN517 and PN524, and to a lesser extent PN528, synergised with cisplatin against OE33 cells. Cisplatin and oxaliplatin synergised with aspirin and PN517 when tested against the SW480 cell line. Conclusion: These findings indicate the potential and limitations of aspirin and aspirin analogues as chemotherapeutic agents against OC and CRC when combined with platins

Generation of a Novel Regulatory NK Cell Subset from Peripheral Blood CD34+ Progenitors Promoted by Membrane-Bound IL-15

BACKGROUND: NK cells have been long time considered as cytotoxic lymphocytes competent in killing virus-infected cells and tumors. However, NK cells may also play essential immuno-regulatory functions. In this context, the real existence of a defined NK subset with negative regulatory properties has been hypothesized but never clearly demonstrated. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we show the in vitro generation from human peripheral blood haematopoietic progenitors (PB-HP), of a novel subset of non-cytolytic NK cells displaying a mature phenotype and remarkable immuno-regulatory functions (NK-ireg). The main functional hallmark of these NK-ireg cells is represented by the surface expression/release of HLA-G, a major immunosuppressive molecule. In addition, NK-ireg cells secrete two powerful immuno-regulatory factors: IL-10 and IL-21. Through these factors, NK-ireg cells act as effectors of the down-regulation of the immune response: reconverting mature myeloid DC (mDC) into immature/tolerogenic DC, blocking cytolytic functions on conventional NK cells and inducing HLA-G membrane expression on PB-derived monocytes. The generation of "NK-ireg" cells is obtained, by default, in culture conditions favouring cell-to-cell contacts, and it is strictly dependent on reciprocal trans-presentation of membrane-bound IL-15 forms constitutively and selectively expressed by human CD34(+) PB-HP. Finally, a small subset of NKp46(+) HLA-G(+) IL-10(+) is detected within freshly isolated decidual NK cells, suggesting that these cells could represent an in vivo counterpart of the NK-ireg cells. CONCLUSIONS/SIGNIFICANCE: In conclusion, NK-ireg cells represent a novel truly differentiated non-cytolytic NK subset with a self-sustainable phenotype (CD56(+) CD16(+) NKp30(+) NKp44(+) NKp46(+) CD94(+) CD69(+) CCR7(+)) generated from specific pSTAT6(+) GATA3(+) precursors. NK-ireg cells could be employed to develop new immuno-suppressive strategies in autoimmune diseases, transplant rejection or graft versus host diseases. In addition, NK-ireg cells can be easily derived from peripheral blood of the patients and could constitute an autologous biotherapic tool to be used combined or in alternative to other immuno-regulatory cells

Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites

The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions. The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that the wood in the starch composites did not prevent water loss from the samples.Peer reviewe