Chiral Symmetry Breaking and Confinement Beyond Rainbow-Ladder Truncation

A non-perturbative construction of the 3-point fermion-boson vertex which obeys its Ward-Takahashi or Slavnov-Taylor identity, ensures the massless fermion and boson propagators transform according to their local gauge covariance relations, reproduces perturbation theory in the weak coupling regime and provides a gauge independent description for dynamical chiral symmetry breaking (DCSB) and confinement has been a long-standing goal in physically relevant gauge theories such as quantum electrodynamics (QED) and quantum chromodynamics (QCD). In this paper, we demonstrate that the same simple and practical form of the vertex can achieve these objectives not only in 4-dimensional quenched QED (qQED4) but also in its 3-dimensional counterpart (qQED3). Employing this convenient form of the vertex \emph{ansatz} into the Schwinger-Dyson equation (SDE) for the fermion propagator, we observe that it renders the critical coupling in qQED4 markedly gauge independent in contrast with the bare vertex and improves on the well-known Curtis-Pennington construction. Furthermore, our proposal yields gauge independent order parameters for confinement and DCSB in qQED3.Comment: 8 pages, 6 figure

Examining the Reliability, Validity and Factor Structure of the DRS-15 with College Athletes

Hardiness, comprising feelings of commitment, control and challenge, is most frequently measured with the Dispositional Resiliency Scale (DRS), but little work has been done with the brief 15-item version. To examine the factor structure, reliability, validity, and item functioning for gender invariance of the 15-item DRS with 525 collegiate athletes from a wide range of sports. Convergent and divergent validity were examined through relationships with mental toughness, grit and competitive anxiety. Participants completed measures of mental toughness, optimism, grit, competitive anxiety, and the DRS-15. Confirmatory Factor Analysis revealed a poor fit for the three-factor hardiness model, and subsequent exploratory factor analysis yielded a four-factor model with better fit than the three-factor structure. Additionally, several items appear to be biased towards males or females. The fourth factor may be unique to the collegiate athlete population, and related to perceived lack of control in future life directions. Convergent and divergent validity were supported through correlations of DRS scores with related measures. The four-factor model should be tested with different samples to determine if these changes should be adapted when using the DRS-15 in collegiate athletics or other settings

A Pilot Study Investigating the Reasons for Playing Through Pain and Injury: Emerging Themes in Men’s and Women’s Collegiate Rugby

Collegiate rugby is a competitive, collision sport, yet insufficient empirical evidence exists regarding participants’ perspectives on pain and injury. This study addressed male and female rugby players’ experiences with injury, and their views about playing through pain and injury. Eleven rugby players (five male; six female) competing in USA Rugby’s National College 7’s tournament participated in semi structured interviews, which were recorded, transcribed, and content-analyzed. Two major themes emerged: passion for sport and sport ethic. Passion for sport was composed of (a) love of the sport, (b) meaning of the sport, and (c) desire to be on the field. Sport ethic included: (a) helping the team, (b) game time sacrifice, (c) personality, (d) minimize, and (e) accepted behavior. The researchers explain these findings and propose strategies for increasing future athletes’ understanding of the dangers associated with playing through pain, and confronting the currently accepted culture of risk

Detection of high-risk human papillomavirus RNA in urine for cervical cancer screening with HPV 16 & 18/45 genotyping

© 2020 The Authors Objective: To detect high-risk human papillomavirus (hrHPV) messenger-RNA (mRNA) in urine samples, compare their concordance with cervical samples including HPV 16 & 18/45 genotyping, and to determine the utility in detecting ≥ CIN 2 lesions. Methods: A cohort of 189 non-pregnant patients (age ≥ 25) was recruited in three groups: Group 1 with abnormal pap-smears and hrHPV positivity, Group 2 with normal pap-smears and hrHPV positivity, and Group 3 with normal pap-smears and hrHPV negativity. Urine samples were tested for hrHPV-mRNA and subsequent hrHPV-mRNA genotype if positive. High-risk HPV detection and genotyping were performed using Aptima assays which are validated for cervical HPV testing. Colposcopy results from groups 1 & 2 were analyzed. Results: The sensitivity of urine hrHPV-mRNA detection was 31.5% while the specificity and PPV were above 95% (96.9% & 95.1% respectively) (p \u3c 0.001). The kappa agreement with cervical samples was fair (0.22, p = 0.04). The sensitivity and specificity of urine hrHPV-mRNA genotyping were 20.0% & 100% respectively (p \u3c 0.001) with 100% genotype-specific concordance. The kappa agreement with cervical samples was fair (0.25, p = 0.16). For urine hrHPV-mRNA detection of ASC-H/HSIL when grouped by age ≥ 30, the sensitivity and specificity were 45.4% & 63.9% respectively (p = 0.009). For urine hrHPV-mRNA detection of ≥ CIN 2 for all ages, the sensitivity and specificity were 45.5% & 75.0% respectively (p = 0.03). Conclusion: Using the Aptima Assay, urine hrHPV-mRNA detection is suboptimal for cervical cancer screening but given the high specificity, it has the potential to identify high-grade lesions (≥ CIN 2). Urine hrHPV-mRNA genotyping via this modality is not beneficial in triage settings of normal or abnormal cytology to determine the need for colposcopy

High resolution HLA-A, -B, -C and -DRB1 allele and haplotype frequencies in the Costa Rica Central Valley population

The Costa Rica Central Valley population (CCVP) is the major population in this country, accounting for over 60% of the Costa Rican inhabitants concentrated since colonial times in a 2,500 km2 intermontane region. Interesting historic, demographic and genetic characteristics of this hybrid population have attracted researchers interested in testing genetic associations for various diseases. However, no study describing Human Leukocyte Antigen (HLA) frequencies by molecular methods had been performed. We have recently described low resolution HLA allele group and haplotype frequencies in a sample of this population. In this report, we extend our study to high resolution by sequence-based typing of exons 2, 3 and 4 for class I, and exon 2 for HLA-DRB1. DNA was extracted from blood or saliva samples from a cohort of 205 non-related healthy donors recruited as part of the University of Costa Rica’s Centre for Research in Hematology and Related Disorders (CIHATA) DNA bank. All participants were born in the CCVP and gave informed consent. A total of 37 HLA-A, 61 HLA-B, 24 HLA-C and 38 HLA-DRB1 alleles were seen in this sample. The five most frequent alleles for these genes are HLA-A*02:01:01, HLA-A*24:02:01, HLA-A*03:01:01, HLA-A*01:01:01, HLA-A*68:01:02, HLA-B*07:02:01, HLA-B*40:02:01, HLA-B*35:01:01, HLA-B*44:02:01, HLA-B*14:02:01, HLA-C*04:01:01, HLA-C*07:02:01, HLA-C*03:05, HLA-C*06:02:01, HLA-C*07:01:01, HLA-DRB1*13:01:01G, HLA-DRB1*04:07:01G, HLA-DRB1*15:01:01G, HLA-DRB1*03:01:01G, and HLA-DRB1*07:01:01G. Preliminary haplotype estimation results show, as a proxy for admixture proportions, that 68% of the extended haplotypes are Caucasian, while 23% are Amerindian in origin and 9% are clearly Sub-Saharan African. Principal coordinates analysis based on HLA-A and –B allele group frequencies reveals that this population clusters among other admixed groups with strong Caucasian component that lie closely to Iberian populations

Spiky Strings on NS5-branes

We study rigidly rotating strings in the near horizon geometry of a stack of Neveu-Schwarz (NS) 5-branes. We solve the Nambu-Goto action of the fundamental string in the presence of a NS-NS two form $(B_{\mu\nu})$ and find out limiting cases corresponding to magnon and spike like solutions.Comment: 10 pages, to appear in PL

Causes of death after liver transplantation in children treated with cyclosporine and steroids

Two-hundred-and-twenty-seven children underwent orthotopic liver transplantation between March 1980 and March 1986. Seventy (31%) patients died during the study period. Four patients who died within 24 hours of the initial liver transplant and 5 patients who died outside of our institution were excluded from the analysis. Liver failure, related to either thrombosis of the hepatic artery, primary non-function of the graft or rejection accounted for 25 of the remaining 61 deaths. In 21 patients death was related to overwheming sepsis while 7 patients died from excessive bleeding. Eight of the deaths were due to a miscellaneous group of causes. Twenty percent of the 150 patients who received a single liver transplant died compared to a death rate of 50% in patients who underwent three transplants. Eighty-five percent of the deaths occurred within 6 months after the initial liver transplant. Liver failure was the cause in the majority of the early deaths whereas the later deaths were more likely to be due to sepsis. This detailed analysis of the causes of death after pediatric liver transplantation in a large group of patients has revealed that advances in certain areas could lead to even better results