STICAP: A linear circuit analysis program with stiff systems capability. Volume 3: Systems

For abstract, see N76-13798

Nicotine strongly activates dendritic cell-mediated adaptive immunity - potential role for progression of atherosclerotic lesions

Background - Antigen-presenting cells (APCs) such as monocytes and dendritic cells (DCs) stimulate T-cell proliferation and activation in the course of adaptive immunity. This cellular interaction plays a role in the growth of atherosclerotic plaques. Nicotine has been shown to increase the growth of atherosclerotic lesions. Therefore, we investigated whether nicotine can stimulate APCs and their T cell–stimulatory capacity using human monocyte–derived DCs and murine bone marrow–derived DCs as APCs. Methods and Results - Nicotine dose-dependently (10-8 to 10-4 mol/L) induced DC expression of costimulatory molecules (ie, CD86, CD40), MHC class II, and adhesion molecules (ie, LFA-1, CD54). Moreover, nicotine induced a 7.0-fold increase in secretion of the proinflammatory TH1 cytokine interleukin-12 by human DCs. These effects were abrogated by the nicotinic receptor antagonist -bungarotoxin and mecamylamine, respectively. The effects of nicotine were mediated in part by the phosphorylation of the PI3 kinase downstream target Akt and the mitogen-activated kinases ERK and p38 MAPK. Nicotine-stimulated APCs had a greater capacity to stimulate T-cell proliferation and cytokine secretion, as documented by mixed lymphocyte reactions and ovalbumin-specific assays with ovalbumin-transgenic DO10.11 mice. In a murine model of atherosclerosis, nicotine significantly enhanced the recruitment of DCs to atherosclerotic lesions in vivo. Conclusions - Nicotine activates DCs and augments their capacity to stimulate T-cell proliferation and cytokine secretion. These effects of nicotine may contribute to its influence on the progression of atherosclerotic lesions

Season-long changes in the body composition profiles of competitive female Rugby Union players assessed via dual energy x-ray absorptiometry

Background: Reference data for the body composition values of female athletes are limited to very few sports, with female Rugby Union players having mostly been omitted from such analyses. Methods: Using dual energy X-ray absorptiometry (DXA) scans, this study assessed the body composition profiles (body mass, bone mineral content; BMC, fat mass; FM, lean mass; LM, bone mineral density; BMD) of 15 competitive female Rugby Union players before and after the 2018/19 competitive season. Total competitive match-play minutes were also recorded for each player. Results: Body mass (73.7±9.6 kg vs 74.9±10.2 kg, p≤0.05, d=0.13) and BMC (3.2±0.4 kg vs 3.3±0.4 kg, p≤0.05, d=0.15) increased pre- to post-season for all players. Conversely, FM (21.0±8.8 kg), LM (50.7±3.9 kg), and BMD (1.31±0.06 g·cm-2) were similar between time-points (all p>0.05). Accounting for position, body mass (rpartial(12) = 0.196), FM (rpartial(12) = -0.013), LM (rpartial(12) = 0.351), BMD (rpartial(12) = 0.168) and BMC (rpartial(12) = -0.204) showed no correlation (all p>0.05) against match-play minutes. Conclusion: The demands of the competitive season influenced specific body composition indices (i.e., body mass, BMC) in female Rugby Union players; a finding which was unrelated to the number of minutes played in matches. While the causes of such differences remain unclear, practitioners should be cognisant of the body composition changes occurring throughout a female Rugby Union competitive season and, where necessary, consider modifying variables associated with adaptation and recovery accordingly

Measurement of the Spatial Cross-Correlation Function of Damped Lyman Alpha Systems and Lyman Break Galaxies

We present the first spectroscopic measurement of the spatial cross-correlation function between damped Lyman alpha systems (DLAs) and Lyman break galaxies (LBGs). We obtained deep u'BVRI images of nine QSO fields with 11 known z ~ 3 DLAs and spectroscopically confirmed 211 R < 25.5 photometrically selected z > 2 LBGs. We find strong evidence for an overdensity of LBGs near DLAs versus random, the results of which are similar to that of LBGs near other LBGs. A maximum likelihood cross-correlation analysis found the best fit correlation length value of r_0 = 2.9^(+1.4)_(-1.5) h^(-1)Mpc using a fixed value of gamma = 1.6. The implications of the DLA-LBG clustering amplitude on the average dark matter halo mass of DLAs are discussed.Comment: 12 pages, 2 figures, accepted for publication in Astrophysical Journal Letter

Atomic layer etching of SiO2 with Ar and CHF 3 plasmas: A self-limiting process for aspect ratio independent etching

With ever increasing demands on device patterning to achieve smaller critical dimensions, the need for precise, controllable atomic layer etching (ALE) is steadily increasing. In this work, a cyclical fluorocarbon/argon plasma is successfully used for patterning silicon oxide by ALE in a conventional inductively coupled plasma tool. The impact of plasma parameters and substrate electrode temperature on the etch performance is established. We achieve the self-limiting behavior of the etch process by modulating the substrate temperature. We find that at an electrode temperature of −10°C, etching stops after complete removal of the modified surface layer as the residual fluorine from the reactor chamber is minimized. Lastly, we demonstrate the ability to achieve independent etching, which establishes the potential of the developed cyclic ALE process for small scale device patterning

Asynchronous displays for multi-UV search tasks

Synchronous video has long been the preferred mode for controlling remote robots with other modes such as asynchronous control only used when unavoidable as in the case of interplanetary robotics. We identify two basic problems for controlling multiple robots using synchronous displays: operator overload and information fusion. Synchronous displays from multiple robots can easily overwhelm an operator who must search video for targets. If targets are plentiful, the operator will likely miss targets that enter and leave unattended views while dealing with others that were noticed. The related fusion problem arises because robots' multiple fields of view may overlap forcing the operator to reconcile different views from different perspectives and form an awareness of the environment by "piecing them together". We have conducted a series of experiments investigating the suitability of asynchronous displays for multi-UV search. Our first experiments involved static panoramas in which operators selected locations at which robots halted and panned their camera to capture a record of what could be seen from that location. A subsequent experiment investigated the hypothesis that the relative performance of the panoramic display would improve as the number of robots was increased causing greater overload and fusion problems. In a subsequent Image Queue system we used automated path planning and also automated the selection of imagery for presentation by choosing a greedy selection of non-overlapping views. A fourth set of experiments used the SUAVE display, an asynchronous variant of the picture-in-picture technique for video from multiple UAVs. The panoramic displays which addressed only the overload problem led to performance similar to synchronous video while the Image Queue and SUAVE displays which addressed fusion as well led to improved performance on a number of measures. In this paper we will review our experiences in designing and testing asynchronous displays and discuss challenges to their use including tracking dynamic targets. © 2012 by the American Institute of Aeronautics and Astronautics, Inc