Experiment Luxembourg

The earlier orbits and ephemerides for the Soviet satellites were not sufficiently accurate to be very useful in making observations in Alaska. Extrapolations from our own observations gave better predictions. This merely pointed out the fact that rough observations of meridian transits at high latitudes will give better values of the inclination of the orbit than precision observations at low latitudes. Hence, it was decided to observe visually the meridian transits estimating the altitude by noting the position with respect to the stars or using crude alidade measurements. The times of the earlier observations were observed on a watch or clock and the clock correction obtained from WWV. Later the times were determined with the aid of stop watches, taking time intervals from WWV signals. This rather meager program of optical observations of the Soviet satellites was undertaken to give supplementary data for use of the radio observations, and particularly to assist in the prediction of position of the satellite so that the 61-foot radar of Stanford Research Institute could be set accurately enough to observe it (the beam width at the half-power points is about 3°). This report contains primarily the visual observations made at the Geophysical Institute by various members of the staff, and a series of observations by Olaf Halverson at Nome, Alaska. In addition there is a short discussion of the geometry of the trajectory, the illumination of a circumpolar satellite, and a note on the evaluation of Brouwer's moment factors.The research reported In this document has been sponsored by the Geophysics Research Directorate of the Air Force Cambridge Research Center* Air Research and Development Command, under Contract AF 19(604)-3880.List of Figures -- Introduction -- Present knowledge of the electron densities and collision frequencies in the D region of the ionosphere. -- The theory of radio wave interaction. -- The outline of the planned experiment. -- Some comments about the planned experiment. Some comments about gyrointeraction. -- Conclusion -- Acknowledgements -- ReferencesYe

Experiment Luxembourg, Scientific Report No. 3

Contract No. AF 19(604)-3860 -- GEOPHYSICS RESEARCH DIRECTORATE AIR FORCE CAMBRIDGE RESEARCH CENTER AIR RESEARCH AND DEVELOPMENT COMMAND UNITED STATES AIR FORCE; BEDFORD, MASSACHUSETTSLIST OF FIGURES -- ABSORPTION OF RADIO WAVES AND METEORIC IONIZATION -- METEORIC IONIZATION -- ABSORPTION AND SPORADIC METEORS -- ABSORPTION AND METEOR SHOWERS -- IONIZING EFFICIENCY OF METEORS -- CONCLUSIONS -- ACKNOWLEDGEMENTS -- REFERENCESYe

Dynamics of the peel front and the nature of acoustic emission during peeling of an adhesive tape

We investigate the peel front dynamics and acoustic emission of an adhesive tape within the context of a recent model by including an additional dissipative energy that mimics bursts of acoustic signals. We find that the nature of the peeling front can vary from smooth to stuck-peeled configuration depending on the values of dissipation coefficient, inertia of the roller, mass of the tape. Interestingly, we find that the distribution of AE bursts shows a power law statistics with two scaling regimes with increasing pull velocity as observed in experiments. In this regimes, the stuck-peeled configuration is similar to the `edge of peeling' reminiscent of a system driven to a critical state.Comment: Accepted for publication in Phys. Rev. Let

Experiment Luxembourg, Scientific Report No. 4

Experiment Luxembourg was designed to measure the electron density and electron collision-frequency as a function of height in the D region over College, Alaska using the technique of radio-wave interaction. A block diagram, which includes all the equipment necessary for the actual operation of the experiment, is described and illustrated in detail. The major parts of the system are: the disturbing transmitter operating on 17.5 Mc/s and using a 4x4 array of Yagi antennas, the wanted transmitter operating on ~ 5 Mc/s and using a circular polarization unit with 4 dipoles arranged in a quadrangle, a similar circular polarization unit and antenna for 5 Mc/s at the receiving site, and the delicate receiving system which detects a cross-modulation of 1x10 -4 for a one volt input signal. Some values of electron density and collision-frequency have been obtained and will be discussed in following publications.Contract No. AF 19(604)-3880 -- GEOPHYSICS RESEARCH DIRECTORATE AIR FORCE CAMBRIDGE RESEARCH LABORATORIES AIR FORCE RESEARCH DIVISION (ARDC) UNITED STATES AIR FORCE BEDFORD, MASSACHUSETTSLIST OP FIGURES -- ABSTRACT -- INTRODUCTION -- TRANSMITTING SITE : Timer Wanted transmitter ; Circular polarization unit ; 5 Mc/s antenna ; Disturbing transmitter ; Duplexer ; 17.5 Mc/s receiver ; 17.5 Mc/s antenna -- RECEIVING SITE : 5 Mc/s antenna ; Circular polarization unit ; 5 Mc/s Super-pro receiver ; Wide band IF amplifier ; Pulse shaper and delay control ; Receiver gate and reference signal generator ; Signal gate ; Selective amplifier ; Phase sensitive detector ; E.A. recorder ; 17.5 Mc/s Collins receiver ; Scope unit ; Calibration -- Results -- AcknowledgementsYe

Acute inflammatory response to contrast agent aspiration and its mechanisms in the rat lung.

Objectives/hypothesisContrast agent (CA) aspiration is an established complication of upper gastrointestinal and videofluoroscopic swallow studies. The underlying molecular biological mechanisms of acute response to CA aspiration in the respiratory organs remain unclear. The aims of this study were to elucidate the histological and biological influences of three kinds of CAs on the lung and to clarify the differences in acute responses.Study designAnimal model.MethodsEight-week-old male Sprague Dawley rats were divided into five groups (n = 6 in each group). Three groups underwent tracheal instillation of one of three different CAs: barium (Ba) sulfate, nonionic contrast agents (NICAs), and ionic contrast agents (ICAs). A control group was instilled with saline and a sham group was instilled with air. All animals were euthanized on day 2 after treatment and histological and gene analysis was performed.ResultsNo animal died after CA or control/sham aspiration. Ba caused severe histopathologic changes and more prominent inflammatory cell infiltration in the lungs compared with the two other iodinated contrast agents. Increases in expressions of inflammatory cytokines (tumor necrosis factor [Tnf], interleukin-1β [Il1b], and interferon-γ [Ifng]) were observed in Ba aspiration rats, and upregulation of Il1b was seen in ICA aspiration rats. NICA did not cause obvious histologic changes or expressions of inflammatory cytokines and fibrosis-related genes in the lungs.ConclusionsBa caused significantly more acute lung inflammation in a rodent model than did ioinic and nonionic iodinated CAs. Nonionic contrast did not cause any discernible inflammatory response in the lungs, suggesting that it may be the safest contrast for videofluoroscopic swallow studies.Level of evidenceNA Laryngoscope, 129:1533-1538, 2019

Network Structure, Topology and Dynamics in Generalized Models of Synchronization

We explore the interplay of network structure, topology, and dynamic interactions between nodes using the paradigm of distributed synchronization in a network of coupled oscillators. As the network evolves to a global steady state, interconnected oscillators synchronize in stages, revealing network's underlying community structure. Traditional models of synchronization assume that interactions between nodes are mediated by a conservative process, such as diffusion. However, social and biological processes are often non-conservative. We propose a new model of synchronization in a network of oscillators coupled via non-conservative processes. We study dynamics of synchronization of a synthetic and real-world networks and show that different synchronization models reveal different structures within the same network

Quarterly Progress Reports Nos. 1-5, 7, 8

This report, prepared during May 1958, summarizes the analysis of over twelve months of amplitude and angular scintillation data obtained using phase-switch interferometers at 223 Mc and 456 Mc on the Cygnus and Cassiopeia radio sources. The main parameters of the equipment used are first discussed. The method of scaling the records, involving the arbitrary division of the records into four (456 Mc) or six (223 Mc) levels of activity is then described. The probability distributions of the amplitude variations, as derived using a phase-sweep interferometer, are given for the main levels of scintillation activity at 223 Mc. Values of mean fractional deviation of power, -A.P. } for the main levels of activity at 223 Mc are also given. Preliminary probability distributions of angular deviation, and values of mean angular deviation, are also given for the different levels of activity at 223 Mc. The solar-time dependence and sidereal-time (elevation angle) dependence of the scintillation activity are presented arid c6mpared with similar data from temperate latitudes. The report concludes with a section in which a recent theory of radio star scintillations^ is modified to include the effect of an elongation of the irregularities along the earth's magnetic lines of force.Air Force Contract No. AF 30(635)-2837 Project No. 5535 - Task 45774 Rome Air Development Center, Griffiss Air Force Base Rome, New YorkTABLE OF CONTENTS -- ABSTRACT -- [SECTION I] The Phase-Switch Interferometers : Main Parameters of the Equipment ; Method of Operation -- [SECTION II] Analysis of Phase-Switch Interferometer Records : Scaling of Records ; Probability of Occurrence of Different Indexes of Scintillation Activity ; Preparation of Monthly Diurnal Curve of the Mean Value A? at 223 Mc. ; Preparation of Mean Solar Time and Sidereal Time Variation of Mean -AP. at 223 Mc. ; Solar Time Dependence of the Mean Values of -4£ at 223 Mc. ; Sidereal Time Dependence of 223 Me Scintillation Activity -- Analysis of Angular Scintillation Information -- [SECTION III] Discussion of Results [SECTION IV] Adaptation to an Anisotropic Ionosphere of Booker's Formulae for Radio Star Scintillations -- [SECTION V] Proposed Program of Further Research [SUMMARY] [REFERENCES]Ye

Obturations en amalgame et modifications des lymphocytes T

Dental amalgam and nickel alloys have been considered quite safe. Previous authors reported the effect of dental amalgam and nickel alloys on human T-lymphocytes modifications after amalgam dental fillings, into dose-dependence of any modifications and into possible temporary.Eight patients were subjected to dental care with amalgam dental fillings. Drawings of blood were executed at start, fifteen days after late fillings and two months later.The results about modifications of T-lymphocytes were not univocal. We believe, at now, that temporary modifications of the immunity seem to be related to a cytotoxic mechanism.Les auteurs ont étudié les modifications systémiques des lymphocytes T (T3) et des sous-populations T4 et T8 après la pose d’obturations en amalgame. Les résultats ne sont pas univoques et leur interprétation n’est pas facile.On pense que l’amalgame dentaire pourrait provoquer une modification transitoire et temporaire des défenses immunitaires par un mécanisme de cytotoxicité