On Non-Linear W-Infinity Symmetry of Generalized Liouville and Conformal Toda Models

Invariance under non-linear ${\sf {\hat W}}_{\infty}$ algebra is shown for the two-boson Liouville type of model and its algebraic generalizations, the extended conformal Toda models. The realization of the corresponding generators in terms of two boson currents within KP hierarchy is presented.Comment: 10 pgs, LaTeX, IFT-P.038/9

A New Deformation of W-Infinity and Applications to the Two-loop WZNW and Conformal Affine Toda Models

We construct a centerless W-infinity type of algebra in terms of a generator of a centerless Virasoro algebra and an abelian spin-1 current. This algebra conventionally emerges in the study of pseudo-differential operators on a circle or alternatively within KP hierarchy with Watanabe's bracket. Construction used here is based on a special deformation of the algebra $w_{\infty}$ of area preserving diffeomorphisms of a 2-manifold. We show that this deformation technique applies to the two-loop WZNW and conformal affine Toda models, establishing henceforth $W_{\infty}$ invariance of these models.Comment: 8 page

Error analysis of bulk density measurements for neutron moisture gauge calibration

Six bulk density sampling methods were evaluated for use in neutron gauge calibration. All six methods provided estimates of bulk density which were generally within 5% of bulk density profiles measured using a gamma probe. Standard errors of estimate ranged from 3 to 7 %. When used with care, downhole, coring, and drive samplers can be used to successfully measure soil moisture and bulk density profiles for use in neutron probe calibration

Soil bulk density sampling for neutron gauge calibration

The ASCE Task Committee on Neutron Gauge Calibration met in Logan, Utah in July 1992 to investigate the various methods of soil sampling, installation of access tubes, effect of various parameters on gauge readings, methods of developing field calibration curves and comparison of neutron gauge characteristics. Details of the overall objectives of the study are covered by Stone (1993, this volume). This paper discusses the soil sampling methods and presents a comparative result based on bulk density, time required for sampling and cost of sampling equipment Other papers developed from this study describe the soils, the three sites investigated and the problems related to the tube installation process

Neutron gauge calibration comparison of methods

Several methods for obtaining soil samples for determining soil water content were used for field calibration of neutron gauges. This paper compares the results of calibration curves obtained from the study data by comparing intercepts, slopes and correlation coefficients ("r" values). The study found differences in characteristics between gauges of the same brand, differences between brands and a great effect by access tube materials on the calibration curve

The ASCE neutron probe calibration study: overview

A workshop was held at Logan, Utah to gather field information on neutron probe calibration and operation. Several techniques and instruments were compared. This paper serves to establish the background information for the work and describe the overall approaches, conditions, and equipment. Other papers presented at this conference provide detailed procedures and results

On Two-Current Realization of KP Hierarchy

A simple description of the KP hierarchy and its multi-hamiltonian structure is given in terms of two Bose currents. A deformation scheme connecting various W-infinity algebras and relation between two fundamental nonlinear structures are discussed. Properties of Fa\'a di Bruno polynomials are extensively explored in this construction. Applications of our method are given for the Conformal Affine Toda model, WZNW models and discrete KP approach to Toda lattice chain.Comment: 28 pages, IFT-P/020/92-SAO-PAULO, Late

Regenerative Metaplastic Clones in COPD Lung Drive Inflammation and Fibrosis

The hallmark features of COPD (inflammation, fibrosis, and mucus hypersecretion) are driven by distinct pathogenic progenitors which pre-exist as minor populations in healthy lungs but dominate in the disease state relative to normal lung stem cells. © 2020 Elsevier Inc.Chronic obstructive pulmonary disease (COPD) is a progressive condition of chronic bronchitis, small airway obstruction, and emphysema that represents a leading cause of death worldwide. While inflammation, fibrosis, mucus hypersecretion, and metaplastic epithelial lesions are hallmarks of this disease, their origins and dependent relationships remain unclear. Here we apply single-cell cloning technologies to lung tissue of patients with and without COPD. Unlike control lungs, which were dominated by normal distal airway progenitor cells, COPD lungs were inundated by three variant progenitors epigenetically committed to distinct metaplastic lesions. When transplanted to immunodeficient mice, these variant clones induced pathology akin to the mucous and squamous metaplasia, neutrophilic inflammation, and fibrosis seen in COPD. Remarkably, similar variants pre-exist as minor constituents of control and fetal lung and conceivably act in normal processes of immune surveillance. However, these same variants likely catalyze the pathologic and progressive features of COPD when expanded to high numbers