12,877 research outputs found
EXPERIMENTAL PRICE VARIABILITY AND CONSUMER RESPONSE: TRACKING POTATO SALES WITH SCANNERS
Consumer/Household Economics, Demand and Price Analysis,
Simulation studies of STOL airplane operations in metropolitan downtown and airport air traffic control environments
The operating problems and equipment requirements for STOL airplanes in terminal area operations in simulated air traffic control (ATC) environments were studied. These studies consisted of Instrument Flight Rules (IFR) arrivals and departures in the New York area to and from a downtown STOL port, STOL runways at John F. Kennedy International Airport, or STOL runways at a hypothetical international airport. The studies were accomplished in real time by using a STOL airplane flight simulator. An experimental powered lift STOL airplane and two in-service airplanes having high aerodynamic lift (i.e., STOL) capability were used in the simulations
Terminal-area flight procedures and route design for supersonic transport New York-transatlantic operations
The results of an analytical investigation of two departure and arrival transition procedures between John F. Kennedy International Airport and projected North Atlantic track systems for supersonic transport (SST) operations are presented. The procedures studied were: (1) separated departure and arrival transition routes with departures made at supersonic speeds, and (2) superimposed departure and arrival routes with departures restricted to subsonic speed until the airplane is on the track system. For both procedures, transition routes with intercept angles of 30 deg to 90 deg to both six-and four-track systems were investigated. Track spacings of 30 and 60 nautical miles were studied
The influence of socio-economic factors on Helicobacter pylori infection rates of students in rural Zambia
A CAJM journal article.Objectives: Although prevalence of disease in sub-Saharan Africa is often quite high and attracts much research, relatively little is known about less critical maladies. We examined Helicobacter pylori infected students in rural Zambia. We attempted to determine if any socio-economic or co-occurring diseases were correlated to H. pylori infection. Understanding the context in which H. pylori infections occur may increase our understanding of this organism.
Design: We conducted a screening survey with diagnostic tests of primary and secondary school students to determine rates of H: pylori infection. We then correlated these rates to socio-economic factors such as income and tobacco use. We also explored the correlation of H. pylori to HIV and malaria.
Setting: Zimba, Zambia.
Subjects: Eighty seven primary and secondary school students.
Main Outcome Measure: Correlation of H. pylori to socio-economic factors.
Results: H. pylori infection was common (60.9%) and was consistent with rates found in other African countries. We found no significant correlation between//. Pylori and disease and socio-economic variables. Conclusion: In the studied population//, pylori infection does not appear to be correlated with the measured socio-economic or disease variables
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