On generating functions in the AKNS hierarchy

It is shown that the self-induced transparency equations can be interpreted as a generating function for as positive so negative flows in the AKNS hierarchy. Mutual commutativity of these flows leads to other hierarchies of integrable equations. In particular, it is shown that stimulated Raman scattering equations generate the hierarchy of flows which include the Heisenberg model equations. This observation reveals some new relationships between known integrable equations and permits one to construct their new physically important combinations. Reductions of the AKNS hierarchy to ones with complex conjugate and real dependent variables are also discussed and the corresponding generating functions of positive and negative flows are found. Generating function of Whitham modulation equations in the AKNS hierarchy is obtained.Comment: 11 pages, no figure

Life cycle modelling of environmental impacts of application of processed organic municipal solid waste on agricultural land (EASEWASTE)

A model capable of quantifying the potential environmental impacts of agricultural application of composted or anaerobically digested source-separated organic municipal solid waste (MSW) is presented. In addition to the direct impacts, the model accounts for savings by avoiding the production and use of commercial fertilizers. The model is part of a larger model, Environmental Assessment of Solid Waste Systems and Technology (EASEWASTE), developed as a decisionsupport model, focusing on assessment of alternative waste management options. The environmental impacts of the land application of processed organic waste are quantified by emission coefficients referring to the composition of the processed waste and related to specific crop rotation as well as soil type. The model contains several default parameters based on literature data, field experiments and modelling by the agro-ecosystem model, Daisy. All data can be modified by the user allowing application of the model to other situations. A case study including four scenarios was performed to illustrate the use of the model. One tonne of nitrogen in composted and anaerobically digested MSW was applied as fertilizer to loamy and sandy soil at a plant farm in western Denmark. Application of the processed organic waste mainly affected the environmental impact categories global warming (0.4–0.7 PE), acidification (–0.06 (saving)–1.6 PE), nutrient enrichment (–1.0 (saving)–3.1 PE), and toxicity. The main contributors to these categories were nitrous oxide formation (global warming), ammonia volatilization (acidification and nutrient enrichment), nitrate losses (nutrient enrichment and groundwater contamination), and heavy metal input to soil (toxicity potentials). The local agricultural conditions as well as the composition of the processed MSW showed large influence on the environmental impacts. A range of benefits, mainly related to improved soil quality from long-term application of the processed organic waste, could not be generally quantified with respect to the chosen life cycle assessment impact categories and were therefore not included in the model. These effects should be considered in conjunction with the results of the life cycle assessment

Extracting Spooky-activation-at-a-distance from Considerations of Entanglement

Following an early claim by Nelson & McEvoy \cite{Nelson:McEvoy:2007} suggesting that word associations can display `spooky action at a distance behaviour', a serious investigation of the potentially quantum nature of such associations is currently underway. This paper presents a simple quantum model of a word association system. It is shown that a quantum model of word entanglement can recover aspects of both the Spreading Activation equation and the Spooky-activation-at-a-distance equation, both of which are used to model the activation level of words in human memory.Comment: 13 pages, 2 figures; To appear in Proceedings of the Third Quantum Interaction Symposium, Lecture Notes in Artificial Intelligence, vol 5494, Springer, 200

Inflammatory markers and overall survival in older adults with cancer

Background: Our aim was to evaluate the prognostic impact of three inflammatory markers - neutrophil lymphocyte ratio (NLR), platelet lymphocyte ratio (PLR) and lymphocyte monocyte ratio (LMR) - on overall survival (OS) in older adults with cancer. Materials and Methods: Our sample includes 144 patients age ≥ 65 years with solid tumor cancer who completed a cancer-specific Geriatric Assessment (GA) from 2010 to 2014 and had pretreatment CBC with differential. NLR was dichotomized a previously reported cut-off value of 3.5, while PLR and LMR were dichotomized at the median. Cox proportional hazards models evaluated whether NLR, PLR and LMR were predictive of OS independent of covariates including a recently developed 3-item GA-derived prognostic scale consisting of (1) “limitation in walking several blocks” (2) “limitation in shopping” and (3) “≥ 5% unintentional weight loss in 6 months”. Results: Median age was 72 years, 53% had breast cancer, 27% had stage 4 cancer, 14% had Karnofsky Performance Status (KPS) 3.5. In univariable analysis, higher NLR and PLR and lower LMR were significantly associated with worse OS. NLR remained a significant predictor of OS (HR = 2.16, 95% CI; 1.10–4.25, p =.025) after adjusting for cancer type, stage, age, KPS, treatment intensity, and the GA-derived prognostic scale. Conclusion: NLR > 3.5 is predictive of poorer OS in older adults with cancer, independent of traditional prognostic factors and the GA-derived prognostic scale

The incremental value of a geriatric assessment-derived three-item scale on estimating overall survival in older adults with cancer

Objective: A geriatric assessment (GA) assesses functional age of older patients with cancer and is a well-established tool predictive of toxicity and survival. The objective of this study was to investigate the prognostic value of individual GA items. Materials and Methods: 546 patients with cancer ≥ 65 years completed GA from 2009 to 2014 and were followed for survival status for a median of 3.7 years. The GA consisted of function, nutrition, comorbidity, cognition, psychological state, and social activity/support domains. GA items with p < 0.05 in univariable analyses for overall survival (OS) were entered into multivariable stepwise selection procedure using a Cox proportional hazards model. A prognostic scale was constructed with significant GA items retained in the final model. Results: Median age was 72 years, 49% had breast cancer, and 42% had stage 3–4 cancer. Three GA items were significant prognostic factors, independent of traditional factors (cancer type, stage, age, and Karnofsky Performance Status): (1) “limitation in walking several blocks”, (2) “limitation in shopping”, and (3) “≥ 5% unintentional weight loss in 6 months”. A three-item prognostic scale was constructed with these items. In comparison with score 0 (no positive items), hazard ratios for OS were 1.85 for score 1, 2.97 for score 2, and 8.67 for score 3. This translated to 2-year estimated survivals of 85%, 67%, 51% and 17% for scores of 0, 1, 2 and 3, respectively. Conclusions: This three-item scale was a strong independent predictor of survival. If externally validated, this could be a streamlined tool with broader applicability

Understanding and identifying immortal-time bias in surgical health services research: An example using surgical resection of stage IV breast cancer

This article presents an overview of how to recognize and address the challenges of immortal time bias using surgical resection of the primary tumor for stage IV female breast cancer patients as a real world example. Surgical health services researchers are increasingly utilizing observational data to assess associations between treatments and outcomes, especially since some procedures are unable to be evaluated through randomized controlled trials. However, the results of many of these studies may be affected by the presence of immortal-time bias, which exists when treatment does not occur on Day 0 of the study. This bias can result in researchers overestimating a treatment benefit, or even observe a treatment benefit when none exists. In this paper, we describe what immortal-time bias is, the challenges it presents, and how to recognize and address it using the real-world example of surgical resection of the primary tumor for stage IV breast cancer throughout. In our example, we guide researchers and illustrate how the early studies, which did not account for immortal-time bias, suggested a protective benefit of surgery, and how these results were supplanted by more recent studies through identifying and addressing immortal-time bias in their design and analyse

Medicare/medicaid insurance, rurality, and black race associated with provision of hepatocellular carcinoma treatment and survival

Background: Early treatment of hepatocellular carcinoma (HCC) is associated with improved survival, but many patients with HCC do not receive therapy. We aimed to examine factors associated with HCC treatment and survival among incident patients with HCC in a statewide cancer registry. Materials and Methods: All patients with HCC from 2003 through 2013 were identified in the North Carolina cancer registry. These patients were linked to insurance claims from Medicare, Medicaid, and large private insurers in North Carolina. Associations between prespecified covariates and more advanced HCC stage at diagnosis (ie, multifocal cancer), care at a liver transplant center, and provision of HCC treatment were examined using multivariate logistic regression. A Cox proportional hazards model was developed to assess the association between these factors and survival. Results: Of 1,809 patients with HCC, 53% were seen at a transplant center,90 days from diagnosis, with lower odds among those who were Black (adjusted odds ratio [aOR], 0.54; 95% CI, 0.39-0.74), had Medicare insurance (aOR, 0.35; 95% CI, 0.21-0.59), had Medicaid insurance (aOR, 0.46; 95% CI, 0.28-0.77), and lived in a rural area; odds of transplant center visits were higher among those who had prediagnosis alpha fetoprotein screening (aOR, 1.74; 95% CI, 1.35-2.23) and PCP and gastroenterology care (aOR, 1.66; 95% CI, 1.27-2.18). Treatment was more likely among patients who had prediagnosis gastroenterology care (aOR, 1.68; 95% CI, 0.98-2.86) and transplant center visits (aOR, 2.42; 95% CI, 1.74-3.36). Survival was strongly associated with age, cancer stage, cirrhosis complications, and receipt of HCC treatment. Individuals with Medicare (adjusted hazard ratio [aHR], 1.58; 95% CI, 1.20-2.09) and Medicaid insurance (aHR, 1.55; 95% CI, 1.17-2.05) had shorter survival than those with private insurance. Conclusions: In this population-based cohort of patients with HCC, Medicare/Medicaid insurance, rural residence, and Black race were associated with lower provision of HCC treatment and poorer survival. Efforts should be made to improve access to care for these vulnerable populations