5,801 research outputs found
Recommended from our members
Modelling Martian dust storms: feedbacks between dust and atmospheric circulation at a hierarchy of scales
We employ numerical models of Mars at spatial scales ranging from global to a few metres in order to investigate both the impact of increasing dust loading on atmospheric circulations and the role of different atmospheric circulation components on dust lifting, transport and on dust storm decay
Lunar laser ranging data deposited in the National Space Science Data Center: Unfiltered photon detections for September 1969 through June 1970
Documentation is presented which is to be used in conjunction with the deposition in the National Space Science Data Center of the unfiltered data obtained during laser ranging operations between the McDonald Observatory and the reflector at Tranquility Base during the interval September 1969 through June 1970
Aviation's role in earth resources surveys
The role of satellites designed to make a wide variety of earth observations is discussed along with the renewed interest in the use of aircraft as platforms for similar and complementary earth resources surveys. Surveys covering the areas of forestry, agriculture, hydrology, oceanography, geology, and geography are included. Aerials surveys equipped for nonphotographic remote sensing and aircraft flights synchronized with satellite observations to provide correlated data are discussed. Photographs are shown to illustrate preliminary results from several of the test sites
Proceedings of the JPL seminar on uncertainties in the lunar ephemeris
Conference on lunar theory and ephemeris analyse
Lunar motion analysis and laser data management
Work completed in lunar motion analysis and laser data management during the period July 1, 1971 - September 30, 1975 was reported. In this context, analysis refers to theoretical or numerical studies involving real or potential applications of such observations to improvement of the physical model, and data management refers to the process by which observed photon events are turned into observations and are made available to potential users. The data analysis work included: (1) bringing to operational status of computer programs for the numerical integration of the lunar orbit motion and for the application of lunar laser time delays for the improvement of the parameters of the physical model, (2) program improvement and program integrity, (3) three-dimensional ephemeris, and (4) miscellaneous independent studies. The data management work included: (1) data identification, (2) observatory interfaces, and (3) data distribution
Lunar laser ranging data deposited in the National Space Science Data Center: Filtered observations for September 1969 through June 1970 and unfiltered photon detections for July through December 1970
The technique of laser ranging to a reflector fixed on the lunar surface is discussed. The causes for initial low rate of data acquisition are explained. The documentation to be used in conjunction with the deposition of the filtered data in the National Space Science Data Center are documented. Filtered data obtained during laser operations between the McDonald Observatory and the reflector at Tranquility Base during the interval September 1969 through June 1970 are presented. The unfiltered photon detections for the succeeding six months are examined
Interaction of the phencyclidine model of schizophrenia and nicotine on total and categorized ultrasonic vocalizations in rats
Patients with schizophrenia smoke cigarettes at a higher rate than the general population. We hypothesized that a factor in this comorbidity is sensitivity to the reinforcing and reinforcement- enhancement effects of nicotine.
Phencyclidine (PCP) was used to model behavioral changes resembling negative symptoms of schizophrenia in rats. USVs in rats have been used to measure emotional states, with 50 kHz USVs indicating positive states and 22 kHz indicating negative. Total and categorized numbers of 22 and 50 kHz ultrasonic vocalizations (USVs) and USVs during a visual stimulus (e.g. a potential measure of reinforcement-enhancement) were examined in rats following .injection ofh PCP (2.0 mg/kg), and/or nicotine (0.2 or 0.4 mg/kg) daily for 7 days. PCP was then discontinued and all rats received nicotine (0.2 mg/kg and 0.4 mg/kg) and PCP (2.0 mg/kg) on 3 challenge days.
PCP acutely decreased 50 kHz vocalizations while repeated nicotine potentiated rates of vocalizations, with similar patterns during light presentations. Rats in the PCP and nicotine combination groups made more 50 kHz vocalizations compared to control groups on challenge days.
We conclude that PCP may produce a reward deficit that is shown by decreased 50 kHz USVs, and behaviors post-PCP exposure may best model the comorbidity between schizophrenia and nicotine
Recommended from our members
Water ice clouds in a martian global climate model using data assimilation
The water cycle is one of the key seasonal cycles on Mars, and the radiative effects of water ice clouds have recently been shown to alter the thermal structure of the atmosphere. Current Mars General Circulation Models (MGCMs) are capable of representing the formation and evolution of water ice clouds, though there are still many unanswered questions regarding their effect on the water cycle, the local atmosphere and the global circulation. We discuss the properties of clouds in the LMD/UK MGCM and compare them with observations, focusing on the differences between the water ice clouds in a standalone model and those in a model which has been modified by assimilation of thermal and aerosol opacity spacecraft data
NASA/ESA CV-990 Spacelab Simulation (ASSESS 2)
To test the validity of the ARC approach to Spacelab, several missions simulating aspects of Spacelab operations have been conducted as part of the ASSESS Program. Each mission was designed to evaluate potential Shuttle/Spacelab concepts in increasing detail. For this mission, emphasis was placed on development and exercise of management techniques planned for Spacelab using management participants from NASA and ESA who have responsibilities for Spacelab 1 which will be launched in 1980
- …
