Characterization and washability studies of raw coal from the Little Tonzona Field, Alaska

Coal occurs in an isolated exposure of Tertiary, non-marine sedimentary rocks along the southwest bank of the Little Tonzona River, near Farewell, Alaska. The Little Tonzona River coal field is located approximately 150 air miles northwest of Anchorage, Alaska, and 210 air miles southwest of Fairbanks, Alaska; near the boundaries of Denali National Park. The Alaska Railroad and the Parks Highway are approximately 100 air miles from the coal field at their nearest point. The village of McGrath, on the Kuskokwim River, is located approximately 90 miles to the west (1). An impressive outcrop of coal-bearing Tertiary sediments is exposed for a distance of more than 275 feet on the west bank of the Little Tonzona River (Figure 1). More than seven coal beds, ranging in thickness from 3 feet ta 30 feet, with a cumulative thickness of over 134 feet, are interbedded with clay beds up to 40 feet thick. The clays are fine textured, extremely plastic, light grey to nearly white bentonites andlor tonsteins. Doyon Ltd., an ANSCA Native Corporation, holds land selections covering the inferred limits of the coal field. During 1980 and 1981, Doyon entered into exploration agreements with McIntyre Mines Inc. of Nevada. The two season exploration program took place from June 1,1980 through August 22,1980 and from May 27,1981 through August 22, 1981. During the 1980 field season, geologic mapping, prospecting, stratigraphy, trenching and bulk sampling of all coal outcrops were performed. This produced a total of 34 samples, which were taken for analysis. In 1981, six diamond drill holes with a cumulative length of 2,935 feet were completed. Core recovery was close to 90%, and a total of 147 coal samples, which represented 802.8 cumulative feet of coal, were taken for analysis. The exploration program confirmed a strike length of over 3 miles to the southwest from the main river bank exposure. Northward extension is unknown at this time. Although outcrop exposure is poor away from the river banks, burnout zones resulting from past coal bed fires form a resistant, recognizable on strike feature in the relatively unindurated Tertialy sequence. The appearance of these burnout zones along strike is often the only surface indication of the buried coal-bearing strata. Well preserved plant fossil impressions in the baked clays date the deposit as probable Miocene (2). Coal characterization and washability studies were performed on all coal samples by the Mineral Industry Research Laboratory of the University of Alaska Fairbanks. This work was conducted under the direction of Dr. P.D. Rao, Professor of Coal Technology.This study was conducted under the sponsorship of McIntyre Mines Ltd

Positioning drug allergy delabeling as a critical tool for precision medicine, quality improvement, and public health

It has been over 75 years since the first use of penicillin and the first description of penicillin-associated hypersensitivity reactions..

p21-activated kinase (PAK) regulates cytoskeletal reorganization and directional migration in human neutrophils

Neutrophils serve as a first line of defense in innate immunity owing in part to their ability to rapidly migrate towards chemotactic factors derived from invading pathogens. As a migratory function, neutrophil chemotaxis is regulated by the Rho family of small GTPases. However, the mechanisms by which Rho GTPases orchestrate cytoskeletal dynamics in migrating neutrophils remain ill-defined. In this study, we characterized the role of p21-activated kinase (PAK) downstream of Rho GTPases in cytoskeletal remodeling and chemotactic processes of human neutrophils. We found that PAK activation occurred upon stimulation of neutrophils with f-Met-Leu-Phe (fMLP), and PAK accumulated at the actin-rich leading edge of stimulated neutrophils, suggesting a role for PAK in Rac-dependent actin remodeling. Treatment with the pharmacological PAK inhibitor, PF3758309, abrogated the integrity of RhoA-mediated actomyosin contractility and surface adhesion. Moreover, inhibition of PAK activity impaired neutrophil morphological polarization and directional migration under a gradient of fMLP, and was associated with dysregulated Ca2+ signaling. These results suggest that PAK serves as an important effector of Rho-family GTPases in neutrophil cytoskeletal reorganization, and plays a key role in driving efficient directional migration of human neutrophils

Continuum theory of vacancy-mediated diffusion

We present and solve a continuum theory of vacancy-mediated diffusion (as evidenced, for example, in the vacancy driven motion of tracers in crystals). Results are obtained for all spatial dimensions, and reveal the strongly non-gaussian nature of the tracer fluctuations. In integer dimensions, our results are in complete agreement with those from previous exact lattice calculations. We also extend our model to describe the vacancy-driven fluctuations of a slaved flux line.Comment: 25 Latex pages, subm. to Physical Review

How different experimental models of secondary hyperalgesia change the nociceptive flexion reflex

In this neurophysiological study in healthy humans, we assessed how central sensitization induced by either high-frequency stimulation (HFS) or topical capsaicin application modulates features of the RIII reflex response. The ability of these stimuli to engage the endogenous pain modulatory system was also tested. In 26 healthy participants we elicited an RIII reflex using suprathreshold stimulation of the sural nerve. Subsequently HFS or capsaicin were applied to the foot and the RIII reflex repeated after 15 minutes. Contact heating of the volar forearm served as the heterotopic test stimulus to probe activation of the endogenous pain modulatory system. HFS significantly reduced the pain threshold by 29% and the RIII reflex threshold by 20%. Capsaicin significantly reduced the pain threshold by 17% and the RIII reflex threshold by 18%. Both HFS and capsaicin left RIII reflex size unaffected. Numerical Rating Scale (NRS) pain scores elicited by the heterotopic noxious heat stimulus were unaffected by capsaicin and slightly increased by HFS. HFS and capsaicin similarly modulated the pain threshold and RIII reflex threshold, without a concomitant inhibitory effect of the endogenous pain modulatory system. Our neurophysiological study supports the use of the RIII reflex in investigating central sensitization in humans

A geometric discretisation scheme applied to the Abelian Chern-Simons theory

We give a detailed general description of a recent geometrical discretisation scheme and illustrate, by explicit numerical calculation, the scheme's ability to capture topological features. The scheme is applied to the Abelian Chern-Simons theory and leads, after a necessary field doubling, to an expression for the discrete partition function in terms of untwisted Reidemeister torsion and of various triangulation dependent factors. The discrete partition function is evaluated computationally for various triangulations of $S^3$ and of lens spaces. The results confirm that the discretisation scheme is triangulation independent and coincides with the continuum partition functionComment: 27 pages, 5 figures, 6 tables. in late

Threshold criterion for wetting at the triple point

Grand canonical simulations are used to calculate adsorption isotherms of various classical gases on alkali metal and Mg surfaces. Ab initio adsorption potentials and Lennard-Jones gas-gas interactions are used. Depending on the system, the resulting behavior can be nonwetting for all temperatures studied, complete wetting, or (in the intermediate case) exhibit a wetting transition. An unusual variety of wetting transitions at the triple point is found in the case of a specific adsorption potential of intermediate strength. The general threshold for wetting near the triple point is found to be close to that predicted with a heuristic model of Cheng et al. This same conclusion was drawn in a recent experimental and simulation study of Ar on CO_2 by Mistura et al. These results imply that a dimensionless wetting parameter w is useful for predicting whether wetting behavior is present at and above the triple temperature. The nonwetting/wetting crossover value found here is w circa 3.3.Comment: 15 pages, 8 figure

Deconstructing 1S0 nucleon-nucleon scattering

A distorted-wave method is used to analyse nucleon-nucleon scattering in the 1S0 channel. Effects of one-pion exchange are removed from the empirical phase shift to all orders by using a modified effective-range expansion. Two-pion exchange is then subtracted in the distorted-wave Born approximation, with matrix elements taken between scattering waves for the one-pion exchange potential. The residual short-range interaction shows a very rapid energy dependence for kinetic energies above about 100 MeV, suggesting that the breakdown scale of the corresponding effective theory is only 270MeV. This may signal the need to include the Delta resonance as an explicit degree of freedom in order to describe scattering at these energies. An alternative strategy of keeping the cutoff finite to reduce large, but finite, contributions from the long-range forces is also discussed.Comment: 10 pages, 2 figures (introduction revised, references added; version to appear in EPJA

Categorizing Different Approaches to the Cosmological Constant Problem

We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future reference. We find that they all can be classified into five different schemes of which we indicate the advantages and drawbacks. Besides, we add a new approach based on a symmetry principle mapping real to imaginary spacetime.Comment: updated version, accepted for publicatio