Renormalization of QCD_2

The low energy infrared scaling of the multi-color 2-dimensional quantum chromodynamics is determined in the framework of its bosonized model by using the functional renormalization group method with gliding sharp cut-off k in momentum space in the local potential approximation. The model exhibits a single phase with a superuniversal effective potential.Comment: 15 pages, 3 figures, final versio

Functional renormalization group with a compactly supported smooth regulator function

The functional renormalization group equation with a compactly supported smooth (CSS) regulator function is considered. It is demonstrated that in an appropriate limit the CSS regulator recovers the optimized one and it has derivatives of all orders. The more generalized form of the CSS regulator is shown to reduce to all major type of regulator functions (exponential, power-law) in appropriate limits. The CSS regulator function is tested by studying the critical behavior of the bosonized two-dimensional quantum electrodynamics in the local potential approximation and the sine-Gordon scalar theory for d<2 dimensions beyond the local potential approximation. It is shown that a similar smoothing problem in nuclear physics has already been solved by introducing the so called Salamon-Vertse potential which can be related to the CSS regulator.Comment: JHEP style, 11 pages, 2 figures, proofs corrected, accepted for publication by JHE

Phase Structure and Compactness

In order to study the influence of compactness on low-energy properties, we compare the phase structures of the compact and non-compact two-dimensional multi-frequency sine-Gordon models. It is shown that the high-energy scaling of the compact and non-compact models coincides, but their low-energy behaviors differ. The critical frequency $\beta^2 = 8\pi$ at which the sine-Gordon model undergoes a topological phase transition is found to be unaffected by the compactness of the field since it is determined by high-energy scaling laws. However, the compact two-frequency sine-Gordon model has first and second order phase transitions determined by the low-energy scaling: we show that these are absent in the non-compact model.Comment: 21 pages, 5 figures, minor changes, final version, accepted for publication in JHE

Multifocal Joint Osteonecrosis in Sickle Cell Disease

The purpose of this study was to evaluate the frequency of multifocal osteonecrosis in patients with sickle cell disease. Between 1980 and 1989, 200 patients with sickle cell disease were treated in our institution for osteonecrosis. The patient population consisted of 102 males and 88 females with a mean age of twenty-six years at the time of presentation (range, eighteen to thirty-five years) and was followed until the year 2005. This cohort of patients was follow-up during average 15 years (until the year 2005). Multifocal osteonecrosis was defined as a disease of 3 or more anatomic sites. At the time of presentation, 49 patients were identified as having multifocal osteonecrosis. At the most recent follow-up, 87 patients had multifocal osteonecrosis. So at the last follow up among these eighty-seven patients, the occurrence of osteonecrosis was 158 lesions of the proximal femur associated with 151 proximal humerus osteonecroses, thirty-three lateral femoral condyle osteonecroses, twenty-eight distal femoral metaphysis osteonecroses, twenty-seven medial femoral condyle osteonecroses, twenty-three tibial plateau osteonecroses, twenty-one upper tibial metaphysis osteonecroses and forteen ankle osteonecroses. The total number of osteonecrosis was 455 in these 87 patients. The epiphyseal lesions were more frequent than the metadiaphyseal lesions excepted in the proximal tibia (Table 3). In conclusion, in patients with sickle cell disease, the risk of multifocal osteonecrosis is very high. In patients with hip osteonecrosis, the other joints should be evaluated with radiograph and MRI if the joint is symptomatic. In patients with osteonecrosis of the knee, shoulder or ankle, the patients’ hip should be evaluated by radiographs or MRI, regardless of whether the hip is symptomatic

The systemic lupus erythematosus IRF5 risk haplotype is associated with systemic sclerosis

Systemic sclerosis (SSc) is a fibrotic autoimmune disease in which the genetic component plays an important role. One of the strongest SSc association signals outside the human leukocyte antigen (HLA) region corresponds to interferon (IFN) regulatory factor 5 (IRF5), a major regulator of the type I IFN pathway. In this study we aimed to evaluate whether three different haplotypic blocks within this locus, which have been shown to alter the protein function influencing systemic lupus erythematosus (SLE) susceptibility, are involved in SSc susceptibility and clinical phenotypes. For that purpose, we genotyped one representative single-nucleotide polymorphism (SNP) of each block (rs10488631, rs2004640, and rs4728142) in a total of 3,361 SSc patients and 4,012 unaffected controls of Caucasian origin from Spain, Germany, The Netherlands, Italy and United Kingdom. A meta-analysis of the allele frequencies was performed to analyse the overall effect of these IRF5 genetic variants on SSc. Allelic combination and dependency tests were also carried out. The three SNPs showed strong associations with the global disease (rs4728142: P = 1.34×10&lt;sup&gt;−8&lt;/sup&gt;, OR = 1.22, CI 95% = 1.14–1.30; rs2004640: P = 4.60×10&lt;sup&gt;−7&lt;/sup&gt;, OR = 0.84, CI 95% = 0.78–0.90; rs10488631: P = 7.53×10&lt;sup&gt;−20&lt;/sup&gt;, OR = 1.63, CI 95% = 1.47–1.81). However, the association of rs2004640 with SSc was not independent of rs4728142 (conditioned P = 0.598). The haplotype containing the risk alleles (rs4728142*A-rs2004640*T-rs10488631*C: P = 9.04×10&lt;sup&gt;−22&lt;/sup&gt;, OR = 1.75, CI 95% = 1.56–1.97) better explained the observed association (likelihood P-value = 1.48×10&lt;sup&gt;−4&lt;/sup&gt;), suggesting an additive effect of the three haplotypic blocks. No statistical significance was observed in the comparisons amongst SSc patients with and without the main clinical characteristics. Our data clearly indicate that the SLE risk haplotype also influences SSc predisposition, and that this association is not sub-phenotype-specific

A prospective study of XRCC1 (X-ray cross-complementing group 1) polymorphisms and breast cancer risk

INTRODUCTION: The gene XRCC1 (X-ray repair cross-complementing group 1) encodes a protein involved in DNA base excision repair. Two non-synonymous polymorphisms in XRCC1 (Arg194Trp and Arg399Gln) have been shown to alter DNA repair capacity in some studies in vitro. However, results of previous association studies of these two XRCC1 variants and breast cancer have been inconsistent. We examined the association between polymorphisms in XRCC1 and breast cancer in the American Cancer Society Cancer Prevention Study II (CPS-II) Nutrition Cohort, a large prospective study of cancer incidence in the USA. METHODS: Among the 21,965 women who were cancer-free in 1992 and gave blood between 1998 and 2001, 502 postmenopausal breast cancer cases were diagnosed between 1992 and 2001; 502 controls were matched to cases on age, race/ethnicity, and date of blood collection. Genotyping on DNA extracted from buffy coat was performed with Taqman. Conditional logistic regression was used to examine the association between each polymorphism and breast cancer risk controlling for breast cancer risk factors. We also examined whether factors associated with DNA damage, such as smoking and antioxidant intake, modified the association between XRCC1 polymorphisms and breast cancer. RESULTS: We observed a significant inverse association between Trp194 carriers (Trp/Trp and Trp/Arg) compared with Trp194 non-carriers in relation to breast cancer (Arg/Arg) (odds ratio (OR) 0.62, 95% confidence interval (CI) 0.40 to 0.95). The inverse association between breast cancer and Trp194 carriers compared with non-carriers was slightly stronger among smokers (OR 0.47, 95% CI 0.24 to 0.94) than never smokers (OR 0.78, 95% CI 0.43 to 1.40). An increased risk associated with the Arg399Gln polymorphism (Gln/Gln versus Arg/Arg) was observed only among women who reported ever smoking cigarettes (OR 2.76, 95% CI 1.36 to 5.63), and not in women who were lifelong non-smokers (OR 0.64, 95% CI 0.33 to 1.26). No other factor examined modified the association between XRCC1 polymorphisms and breast cancer risk. CONCLUSION: Our results support the hypothesis that genetic variation in XRCC1, particularly in Arg194Trp, may influence postmenopausal breast cancer risk. In our study, genetic variation in XRCC1 Arg399Gln was associated with breast cancer risk only among women with a history of smoking cigarettes

Geological time formalization: an improved formal model for describing time successions and their correlation

International audienceGeological time description largely rests on an event based chronology based on the stratigraphical model. It uses a hierarchy of chronologically ordered geochronological units and boundaries. In order to be easily dealt with within large databases used by complex engineering systems, the geological time chronology must be formalized. Stratigraphical time successions should accordingly be described by using adequate semantic tools (ontologies) complemented by a set of logical rules. At present, geological time formalization mainly rests on the GeoSciML model. This model is fit for describing individual geological time scales but does not provide all the necessary tools for comparing various time successions and for operating full stratigraphic correlations. For complementing the GeoSciML model, we define two ontologies for geological time description and for geological dating. They extend the GeoSciML model, so that it becomes possible to fully use the Allen rules for operating time correlations between any couple of time scales or stratigraphic successions. We additionally propose a codification resting on the defined ontologies, which allows operating all age identification and correlation by means of simple computation rules