Gluon confinement criterion in QCD

We fix exactly and uniquely the infrared structure of the full gluon propagator in QCD, not solving explicitly the corresponding dynamical equation of motion. By construction, this structure is an infinite sum over all possible severe (i.e., more singular than $1/q^2$) infrared singularities. It reflects the zero momentum modes enhancement effect in the true QCD vacuum, which is due to the self-interaction of massless gluons. It existence automatically exhibits a characteristic mass (the so-called mass gap). It is responsible for the scale of nonperturbative dynamics in the true QCD ground state. The theory of distributions, complemented by the dimensional regularization method, allows one to put the severe infrared singularities under the firm mathematical control. By an infrared renormalization of a mass gap only, the infrared structure of the full gluon propagator is exactly reduced to the simplest severe infrared singularity, the famous $(q^2)^{-2}$. Thus we have exactly established the interaction between quarks (concerning its pure gluon (i.e., nonlinear) contribution) up to its unimportant perturbative part. This also makes it possible for the first time to formulate the gluon confinement criterion and intrinsically nonperturbative phase in QCD in a manifestly gauge-invariant ways.Comment: 10 pages, no figures, no tables. Typos corrected and the clarification is intoduced. Shorten version to appear in Phys. Lett.

Instanteneous Multi-Baseline Ambiguity Resolution with Constraints

Traditionally the relative positioning and attitude determination problem are treated as independent. In this contribution we will investigate the possibilities to use multiantenna data, not only for attitude determination, but also for the relative positioning. The developed methods are rigorous and have an additional advantage that they improve the ambiguity resolution on the unconstrained baseline and the overall success rate of ambiguity resolution between a number of antenna

Multiplatform instantaneous GNSS ambiguity resolution for triple- and quadruple-antenna configurations with constraints

Traditionally the relative positioning and attitude determination problem are treated as independent. In this contribution we will investigate the possibilities of using multiantenna (i.e., triple and quadruple) data, not only for attitude determination but also for relative positioning. The methods developed are rigorous and have the additional advantage that they improve ambiguity resolution on the unconstrained baseline(s) and the overall success rate of ambiguity resolution between a number of antennas

Testing a new multivariate GNSS carrier phase attitude determination method for remote sensing platforms

GNSS (Global Navigation Satellite Systems)-based attitude determination is an important field of study, since it is a valuable technique for the orientation estimation of remote sensing platforms. To achieve highly accurate angular estimates, the precise GNSS carrier phase observables must be employed. However, in order to take full advantage of the high precision, the unknown integer ambiguities of the carrier phase observables need to be resolved. This contribution presents a GNSS carrier phase-based attitude determination method that determines the integer ambiguities and attitude in an integral manner, thereby fully exploiting the known body geometry of the multi-antennae configuration. It is shown that this integral approach aids the ambiguity resolution process tremendously and strongly improves the capacity of fixing the correct set of integer ambiguities.In this contribution, the challenging scenario of single-epoch, single-frequency attitude determination is addressed. This guarantees a total independence from carrier phase slips and losses of lock, and it also does not require any a priori motion model for the platform. The method presented is a multivariate constrained version of the popular LAMBDA method and it is tested on data collected during an airborne remote sensing campaign

Non-reversible airway obstruction in never smokers: Results from the Austrian BOLD study

SummaryBackgroundThe presence of non-reversible airway obstruction (AO) in never smokers has only received limited attention until now.MethodsWe analyzed data from the Austrian Burden of Obstructive Lung Disease (BOLD) study. We defined non-reversible AO as post-bronchodilator FEV1/FVC <0.7 which corresponds to COPD I and higher (COPD I+) according to current GOLD guidelines. Significant AO was defined as FEV1/FVC <0.7 and FEV1 <80% predicted (GOLD II and higher, GOLD II+). The prevalence and characteristics of non-reversible AO in never smokers were analyzed in relation to the severity of the disease.ResultsNever smokers comprised 47.3% of the study population. Non-reversible AO was seen in 18.2% of never smokers, and 5.5% of never smokers fulfilled criteria for significant non-reversible AO (GOLD stage II+). Therefore, the resulting population prevalence of significant non-reversible AO (GOLD stage II+) was 2.6%. Never smokers with non-reversible AO were predominantly female and slightly older. The airway obstruction was found to be less severe as compared with ever smokers. Despite this, 20% of never smokers with significant non-reversible AO (GOLD stage II+) reported respiratory symptoms and 50% reported impairment of quality of life. This burden of illness in never smokers was similar to that in smokers when severity of AO was taken into account.ConclusionApproximately every third subject with non-reversible AO has never smoked, yet still demonstrates a substantial burden of symptoms and impairment of quality of life. Never smokers should receive far greater attention when efforts are undertaken to prevent and treat chronic airway obstruction

A Qualitative Study Exploring Why Individuals Opt Out of Lung Cancer Screening

Background. Lung cancer screening with annual low-dose computed tomography is relatively new for long-term smokers in the USA supported by a US Preventive Services Task Force Grade B recommendation. As screening programs are more widely implemented nationally and providers engage patients about lung cancer screening, it is critical to understand behaviour among high-risk smokers who opt out to improve shared decision-making processes for lung cancer screening. Objective. The purpose of this study was to explore the reasons for screening-eligible patients’ decisions to opt out of screening after receiving a provider recommendation. Methods. Semi-structured qualitative telephone interviews were performed with 18 participants who met lung cancer screening criteria for age, smoking and pack-year history in Washington State from November 2015 to January 2016. Two researchers with cancer screening and qualitative methodology expertise conducted data analysis using thematic content analytic procedures from audio-recorded interviews. Results. Five primary themes emerged for reasons of opting out of lung cancer screening: (i) Knowledge Avoidance; (ii) Perceived Low Value; (iii) False-Positive Worry; (iv) Practical Barriers; and (v) Patient Misunderstanding. Conclusion. The participants in our study provided insight into why some patients make the decision to opt out of low-dose computed tomography screening, which provides knowledge that can inform intervention development to enhance shared decision-making processes between long-term smokers and their providers and decrease decisional conflict about screening

Comparison of spirometry criteria for the diagnosis of COPD: results from the BOLD study

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldPublished guidelines recommend spirometry to accurately diagnose chronic obstructive pulmonary disease (COPD). However, even spirometry-based COPD prevalence estimates can vary widely. We compared properties of several spirometry-based COPD definitions using data from the international Burden of Obstructive Lung Disease (BOLD)study. 14 sites recruited population-based samples of adults aged > or =40 yrs. Procedures included standardised questionnaires and post-bronchodilator spirometry. 10,001 individuals provided usable data. Use of the lower limit of normal (LLN) forced expiratory volume in 1 s (FEV(1)) to forced vital capacity (FVC) ratio reduced the age-related increases in COPD prevalence that are seen among healthy never-smokers when using the fixed ratio criterion (FEV(1)/FVC <0.7) recommended by the Global Initiative for Chronic Obstructive Lung Disease. The added requirement of an FEV(1) either <80% predicted or below the LLN further reduced age-related increases and also led to the least site-to-site variability in prevalence estimates after adjusting for potential confounders. Use of the FEV(1)/FEV(6) ratio in place of the FEV(1)/FVC yielded similar prevalence estimates. Use of the FEV(1)/FV

An objective classification of condensation regimes in direct contact condensation

Intensified heat treatment, using direct contact condensation (DCC), is applied in the production of dairy products to ensure a high level of food safety. The key challenge with DCC is the fouling due to the protein reactions that limits operational efficiency and sustainability. Using a condensation regime map can improve operational decision-making. Pilot plant scale experiments were conducted for a wide range of steam mass fluxes and inlet temperatures at high and low channel pressures. High-speed images were recorded and analyzed to obtain penetration lengths and plume area. The experimental data and image analysis supplemented with temperature and pressure measurement, were processed using machine learning (ML) to develop a data driven model to predict the regime maps. The linear discriminant analysis (LDA) was found to be the most suitable model. From the ML models it was also found that the best parameters to make a condensation regime map are the steam pressure, channel pressure, subcooling temperature, water Prandtl number, and the relative velocity ratio between gas and liquid. The condensation outcomes were presented with various two-dimensional regime maps. New regime maps are proposed using the Prandtl number and velocity ratio as dimensionless parameters.</p