Chiral Condensate in the Deconfined Phase of Quenched Gauge Theories

We compute the low lying spectrum of the overlap Dirac operator in the deconfined phase of finite-temperature quenched gauge theory. It suggests the existence of a chiral condensate which we confirm with a direct stochastic estimate. We show that the part of the spectrum responsible for the chiral condensate can be understood as arising from a dilute gas of instantons and anti-instantons.Comment: Revtex, 16 pages, 3 postscript figure

A Lattice Study of the Nucleon Excited States with Domain Wall Fermions

We present results of our numerical calculation of the mass spectrum for isospin one-half and spin one-half non-strange baryons, i.e. the ground and excited states of the nucleon, in quenched lattice QCD. We use a new lattice discretization scheme for fermions, domain wall fermions, which possess almost exact chiral symmetry at non-zero lattice spacing. We make a systematic investigation of the negative-parity $N^*$ spectrum by using two distinct interpolating operators at $\beta=6/g^2=6.0$ on a $16^3 \times 32 \times 16$ lattice. The mass estimates extracted from the two operators are consistent with each other. The observed large mass splitting between this state, $N^*(1535)$, and the positive-parity ground state, the nucleon N(939), is well reproduced by our calculations. We have also calculated the mass of the first positive-parity excited state and found that it is heavier than the negative-parity excited state for the quark masses studied.Comment: 46 pages, REVTeX, 11 figures included, revised version accepted for publication in Phys. Rev.

Patterns of care amongst older adults diagnosed with locally advanced esophageal cancer: A cohort study

Introduction: Since the early 2010s, neoadjuvant chemoradiation followed by esophagectomy (trimodal therapy) has been a recommended treatment for patients diagnosed with locally advanced esophageal cancer. However, it may also add treatment-related toxicity, particularly for older adults with significant comorbidity and frailty burdens. We examined contemporary patterns of care in older adults, which have not been well characterized. Materials and Methods: We used the Surveillance Epidemiology and End Results-Medicare database to identify a cohort of US adults aged 66 years and older diagnosed with incident locally advanced esophageal cancer between 2004 and 2017. Calendar year age-standardized percentages of treatment receipt were calculated. Joinpoint regression was used to detect temporal trends in treatment receipt. Descriptive associations between patient factors and treatment were assessed. Trend analyses quantified how the percentage of trimodal and definitive chemoradiation (no surgery) patients receiving cisplatin-based, carboplatin-based, and other chemotherapy regimens evolved over time. Results: In total, 4332 adults aged ≥66 years with locally advanced esophageal cancer were included. The age-standardized percentage of patients receiving trimodal therapy increased from 16.7% in 2004 to 26.1% in 2017 (annual percent change = 3.5%; 95% confidence interval [CI], 0.7%–6.4%) in adenocarcinomas and from 7.3% in 2004 to 9.1% in 2017 (annual percent change = 0.4%; 95% CI, −4.1%–5.1%) in squamous cell carcinomas. By 2017, definitive chemoradiation became the most frequently used treatment modality for adenocarcinomas (49.8%; 95% CI, 43.5–56.0) and squamous cell carcinomas (59.5%; 95% CI, 50.8–68.2). Patients with higher comorbidity and frailty burdens were less likely to be treated with trimodal therapy. Amongst patients receiving chemoradiation as part of their treatment, a large and swift channeling away from cisplatin and towards carboplatin-based regimens was observed. Discussion: In practice, definitive chemoradiation is the most commonly received treatment by older adults with locally advanced esophageal cancer. Four out of five older adults do not receive trimodal therapy, some of whom are potentially undertreated

Trimodality Therapy vs Definitive Chemoradiation in Older Adults With Locally Advanced Esophageal Cancer

Background: The comparative effectiveness of trimodality therapy vs definitive chemoradiation for treating locally advanced esophageal cancer in older adults is uncertain. Existing trials lack generalizability to older adults, a population with heightened frailty. We sought to emulate a hypothetical trial comparing these treatments using real-world data. Methods: A cohort of adults aged 66-79 years diagnosed with locally advanced esophageal cancer between 2004 and 2017 was identified in the Surveillance Epidemiology and End Results-Medicare database. The clone-censor-weight method was leveraged to eliminate time-related biases when comparing outcomes between treatments. Outcomes included overall mortality, esophageal cancer-specific mortality, functional adverse events, and healthy days at home. Results: A total of 1240 individuals with adenocarcinomas and 661 with squamous cell carcinomas were identified. For adenocarcinomas, the standardized 5-year risk of mortality was 73.4% for trimodality therapy and 83.8% for definitive chemoradiation (relative risk [RR] = 0.88, 95% confidence interval [CI] = 0.82 to 0.95). Trimodality therapy was associated with mortality risk reduction for squamous cell carcinomas (RR = 0.87, 95% CI = 0.70 to 1.01). The 1-year incidence of functional adverse events was higher in the trimodality group (adenocarcinomas RR = 1.40, 95% CI = 1.22 to 1.65; squamous cell carcinomas RR = 1.21, 95% CI = 1.00 to 1.49). Over 5 years, trimodality therapy was associated with 160 (95% CI = 67 to 229) and 177 (95% CI = 51 to 313) additional home days in individuals with adenocarcinomas and squamous cell carcinomas, respectively. Conclusions: Compared with definitive chemoradiation, trimodality therapy was associated with reduced mortality but increased risk of function-related adverse events. Discussing these tradeoffs may help optimize care plans

Material and psychological financial hardship related to employment disruption among female adolescent and young adult cancer survivors

Background: The importance of addressing adverse financial effects of cancer among adolescents and young adults (AYAs) is paramount as survival improves. In the current study, the authors examined whether cancer-related employment disruption was associated with financial hardship among female AYA cancer survivors in North Carolina and California. Methods: AYA cancer survivors identified through the North Carolina Central Cancer Registry and the Kaiser Permanente Northern/Southern California tumor registries responded to an online survey. Disrupted employment was defined as reducing hours, taking temporary leave, or stopping work completely because of cancer. Financial hardship was defined as material conditions or psychological distress related to cancer. Descriptive statistics and chi-square tests were used to characterize the invited sample and survey respondents. Marginal structural binomial regression models were used to estimate prevalence differences (PDs) and 95% confidence intervals (95% CIs). Results: Among 1328 women employed at the time of their diagnosis, women were a median age of 34 years at the time of diagnosis and 7 years from diagnosis at the time of the survey and approximately 32% experienced employment disruption. A substantial percentage reported financial hardship related to material conditions (27%) or psychological distress (50%). In adjusted analyses, women with disrupted employment had a 17% higher burden of material conditions (95% CI, 10%-23%) and an 8% higher burden of psychological distress (95% CI, 1%-16%) compared with those without disruption. Conclusions: Financial hardship related to employment disruption among female AYA cancer survivors can be substantial. Interventions to promote job maintenance and transition back to the workforce after treatment, as well as improved workplace accommodations and benefits, present an opportunity to improve cancer survivorship

Patient/Provider Discussions about Clinical Trial Participation and Reasons for Nonparticipation among Adolescent and Young Adult Women with Cancer

Purpose: Clinical trial enrollment is low among adolescents and young adults (AYAs) with cancer and may contribute to inferior survival gains in recent years in this population compared with other age groups. We investigated clinical trial participation among AYA women with cancer, and examined whether patients discussed clinical trial participation with their doctor and reasons for nonparticipation. Methods: Women with a diagnosis of breast cancer, thyroid cancer, melanoma, lymphoma, or gynecologic cancer at ages 15-39 years during 2004-2016 were identified from the North Carolina Central Cancer Registry and the Kaiser Permanente Southern California health system. During 2018-2019, a total of 1264 eligible women completed an online survey (response = 13%), which examined survivorship issues among AYAs. Results: Overall, 5% of participants reported that they had participated in a clinical trial. Most women reported that they had not discussed clinical trial participation with a medical provider (76%) and that they did not know whether a relevant trial was available for their cancer (73%). Among those who knew that a trial was available but did not participate, the most commonly reported reasons for nonparticipation included concerns about side effects of the treatment in the trial and concerns that the treatment had not been sufficiently tested. Conclusion: Only a small proportion of AYA women with cancer in our cohort reported discussing a clinical trial with a provider or knowing whether a relevant trial was available. Our findings point to opportunities to improve patient/provider communication to increase clinical trial enrollment among AYAs with cancer

Optimal inference with suboptimal models:Addiction and active Bayesian inference

When casting behaviour as active (Bayesian) inference, optimal inference is defined with respect to an agent's beliefs - based on its generative model of the world. This contrasts with normative accounts of choice behaviour, in which optimal actions are considered in relation to the true structure of the environment - as opposed to the agent's beliefs about worldly states (or the task). This distinction shifts an understanding of suboptimal or pathological behaviour away from aberrant inference as such, to understanding the prior beliefs of a subject that cause them to behave less 'optimally' than our prior beliefs suggest they should behave. Put simply, suboptimal or pathological behaviour does not speak against understanding behaviour in terms of (Bayes optimal) inference, but rather calls for a more refined understanding of the subject's generative model upon which their (optimal) Bayesian inference is based. Here, we discuss this fundamental distinction and its implications for understanding optimality, bounded rationality and pathological (choice) behaviour. We illustrate our argument using addictive choice behaviour in a recently described 'limited offer' task. Our simulations of pathological choices and addictive behaviour also generate some clear hypotheses, which we hope to pursue in ongoing empirical work

Hadron Structure on the Lattice

A few chosen nucleon properties are described from a lattice QCD perspective: the nucleon sigma term and the scalar strangeness in the nucleon; the vector form factors in the nucleon, including the vector strangeness contribution, as well as parity breaking effects like the anapole and electric dipole moment; and finally the axial and tensor charges of the nucleon. The status of the lattice calculations is presented and their potential impact on phenomenology is discussed.Comment: 17 pages, 9 figures; proceedings of the Conclusive Symposium of the Collaborative Research Center 443 "Many-body structure of strongly interacting systems", Mainz, February 23-25, 201

Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits

The WWgamma triple gauge boson coupling parameters are studied using p-pbar -> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were collected with the DO detector from an integrated luminosity of 162 pb^{-1} delivered by the Fermilab Tevatron Collider. The cross section times branching fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum) pb. The one-dimensional 95% confidence level limits on anomalous couplings are -0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events

We present a measurement of the top quark pair ttbar production cross section in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1} of data collected by the DO detector at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), large missing transverse energy, and at least four jets, and extract the ttbar content of the sample based on the kinematic characteristics of the events. For a top quark mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1} (syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let