Parton distribution functions and quark orbital motion

Covariant version of the quark-parton model is studied. Dependence of the structure functions and parton distributions on the 3D quark intrinsic motion is discussed. The important role of the quark orbital momentum, which is a particular case of intrinsic motion, appears as a direct consequence of the covariant description. Effect of orbital motion is substantial especially for polarized structure functions. At the same time, the procedure for obtaining the quark momentum distributions of polarized quarks from the combination of polarized and unpolarized structure functions is suggested.Comment: 17 pages, 2 figures, 1 table. Paper is accepted for publication in Eur.Phys.J.

Women with anorexia nervosa and bulimia nervosa : Individual and family characteristics, with particular emphasis on perfectionism

This study investigated socio-cultural, family and individual factors associated with anorexia and bulimia nervosa, with particular emphasis on dysfunctional perfectionism, and adopting a general social learning perspective. Theories of the development of eating disorders were interwoven with theories of the development of perfectionism. A model was proposed for the development of anorexia and bulimia nervosa via a dysfunctional perfectionism pathway. The 135 participants, aged 18 to 40 years, were women with anorexia nervosa (N=25), bulimia nervosa (N=32), Type 1 diabetes (N= 53, a North Canterbury population-based sample), and healthy women students (N=25). The women with eating disorders were recruited from various treatment centres throughout New Zealand. Participants completed a battery of seven self-report psychometric tests, namely, the Eating Disorder Inventory-2 (EDI-2), Beck Depression Inventory (BDI), Multidimensional Perfectionism Scale (MPS), Setting Conditions for Anorexia Nervosa Scale (SCANS), Tridimensional Personality Questionnaire (TPQ), Parental Bonding Instrument (PBI), and Family Environment Scale (FES). Analysis of Covariance, using the BDI as a covariate, revealed that, in addition to measures concerned with weight, shape and dieting, both anorexia and bulimia nervosa group means were significantly higher than both healthy and diabetes group means for EDI-2 Interpersonal Distrust and Social Insecurity; MPS Concern over Mistakes, Personal Standards, and Parental Criticism; and TPQ Harm A voidance, and significantly different from the healthy group mean for MPS Parental Expectations; SCANS Perfectionism; and PBI Maternal Protection, Maternal Care, and Paternal Care. Correlational analyses confirmed hypothesized moderate or strong associations between some perfectionism measures and other characteristics of women with eating disorders, such as a harm-avoidant temperament, and perceptions of maternal overprotection. Discriminant function analysis revealed seven variables, in combination, that maximally discriminated between eating disordered and non-eating disordered groups: three EDI-2 variables of Drive for Thinness, Ineffectiveness, and Social Insecurity, three MPS subscales of Concern over Mistakes, Personal Standards, and Doubts about Actions, and the BDI. Of the three instruments measuring perfectionism, in this study, only the MPS effectively discriminated between eating disordered and non-eating disordered groups. Findings indicated the importance of controlling for depression when comparing eating disordered groups with other groups, and that dysfunctional perfectionism is largely independent of the mood of the respondent. Findings suggest that the PBI may be limited by cultural sensitivity. Findings led to questioning of the applicability of the EDI-SC to diabetes groups and of the validity of the Novelty Seeking and Reward Dependence Dimensions of the TPQ. In concluding that dysfunctional perfectionism is a key personality characteristic of women with anorexia and bulimia nervosa, it is argued that multidimensional measures of perfectionism provide more insight than unidimensional measures into the dysfunctional facets of perfectionism, and that perfectionism per se is not necessarily problematic. Dysfunctional perfectionism may distinguish psychopathology associated with anorexia and bulimia nervosa from numerous other forms of psychopathology, including depression. Although aetiological factors were not assessed in this study, the MPS and PBI, considered in conjunction with the theoretical literature, may provide insight into the development of dysfunctional perfectionism. This has implications for the treatment and prevention of eating disorders

Human tumour-associated cell adhesion protein MN/CA IX: identification of M75 epitope and of the region mediating cell adhesion

MN/CA IX is a cell surface protein, strongly associated with several types of human carcinomas. It exerts activity of carbonic anhydrase and capacity of binding to cell surface receptors. In the present work, we used affinity purified MN/CA IX protein to demonstrate that the cells adhere to immobilized MN/CA IX and that the monoclonal antibody M75 abrogates cell attachment to MN/CA IX. Using synthetic oligopeptides, we identified M75 epitope and located it in the proteoglycan domain, which contains a sixfold tandem repeat of six amino acids GEEDLP. From phage display library of random heptapeptides we identified and chemically synthesized those which compete for the epitope with M75 and inhibit adhesion of cells to MN/CA IX. These heptapeptides might serve as lead compounds for drug design. © 2000 Cancer Research Campaig

Understanding the proton's spin structure

We discuss the tremendous progress that has been towards an understanding of how the spin of the proton is distributed on its quark and gluon constituents. This is a problem that began in earnest twenty years ago with the discovery of the proton ``spin crisis'' by the European Muon Collaboration. The discoveries prompted by that original work have given us unprecedented insight into the amount of spin carried by polarized gluons and the orbital angular momentum of the quarks.Comment: Review article for J. Phys. G, 1 figure, 22 page

Centrality dependence of the expansion dynamics in Pb-Pb collisions at 158 A GeV/c

Two-particle correlation functions of negatively charged hadrons from Pb-Pb collisions at 158 GeV/c per nucleon have been measured by the WA97 experiment at the CERN SPS. A Coulomb correction procedure that assumes an expanding source has been implemented. Within the framework of an expanding thermalized source model the size and dynamical state of the collision fireball at freeze-out have been reconstructed as a function of the centrality of the collision. Less central collisions exhibit a different dynamics than central ones: both transverse and longitudinal expansion velocities are slower, the expansion duration is shorter and the system freezes out showing smaller dimensions and higher temperature.Comment: 22 pages, 11 figures, Te

Impact of tapering targeted therapies (bDMARDs or JAKis) on the risk of serious infections and adverse events of special interest in patients with rheumatoid arthritis or spondyloarthritis : a systematic analysis of the literature and meta-analysis

To systematically review the impact of tapering targeted therapies (bDMARDs or JAKis) on the risk of serious infections and severe adverse events (SAEs) in patients with rheumatoid arthritis (RA) or axial spondyloarthritis (axSpA) in remission or low disease activity (LDA) state. A meta-analysis based on a systematic review of PubMed, Embase, Cochrane, until August 2019, as well as relevant databases of international conferences, was used to evaluate the risk difference (RD) at 95% confidence interval (95% CI) of incidence density of serious infections, SAEs, malignancies, cardiovascular adverse events (CV AEs), or deaths after tapering (dose reduction or spacing) compared to continuation of targeted therapies. Of the 1957 studies initially identified, 13 controlled trials (9 RA and 4 SpA trials) were included in the meta-analysis. 1174 patient-years were studied in the tapering group (TG) versus 1086 in the usual care group (UC). There were 1.7/100 patient-year (p-y) serious infections in TG versus 2.6/100 p-y in UC (RD (95% CI) 0.01 (0.00 to 0.02), p = 0.13) and 7.4/100 p-y SAEs in TG versus 6.7/100 p-y in UC (RD 0.00 (− 0.02 to 0.02), p = 0.82). The risk of malignancies, CV AEs, or deaths did not differ between the tapering and the usual care groups. Subgroup analysis (RA and SpA) detected no significant differences between the two groups. We could not show significant impact of tapering bDMARD or JAKi over continuation concerning the risk of serious infections, SAEs, malignancies, CV AEs, or deaths in RA and SpA patients in remission or LDA state

Strangeness enhancements at central rapidity in 40 A GeV/c Pb-Pb collisions

Results are presented on neutral kaon, hyperon and antihyperon production in Pb-Pb and p-Be interactions at 40 GeV/c per nucleon. The enhancement pattern follows the same hierarchy as seen in the higher energy data - the enhancement increases with the strangeness content of the hyperons and with the centrality of collision. The centrality dependence of the Pb-Pb yields and enhancements is steeper at 40 than at 158 A GeV/c. The energy dependence of strangeness enhancements at mid-rapidity is discussed.Comment: 15 pages, 10 figures and 3 tables. Presented at International Conference on Strangeness in Quark Matter (SQM2009), Buzios, Rio de Janeiro, Brazil, 27 Sept - 2 Oct 2009. Submitted to J.Phys.G: Nucl.Part.Phys, one reference adde

Rapidity distributions around mid-rapidity of strange particles in Pb-Pb collisions at 158 AA GeV/c

The production at central rapidity of K0s, Lambda, Xi and Omega particles in Pb-Pb collisions at 158 A GeV/c has been measured by the NA57 experiment over a centrality range corresponding to the most central 53% of the inelastic Pb-Pb cross section. In this paper we present the rapidity distribution of each particle in the central rapidity unit as a function of the event centrality. The distributions are analyzed based on hydrodynamical models of the collisions.Comment: 15 pages, 10 figure