1,432 research outputs found
Potential markets for a satellite-based mobile communications system
The objective of the study was to define the market needs for improved land mobile communications systems. Within the context of this objective, the following goals were set: (1) characterize the present mobile communications industry; (2) determine the market for an improved system for mobile communications; and (3) define the system requirements as seen from the potential customer's viewpoint. The scope of the study was defined by the following parameters: (1) markets were confined to U.S. and Canada; (2) range of operation generally exceeded 20 miles, but this was not restrictive; (3) the classes of potential users considered included all private sector users, and non-military public sector users; (4) the time span examined was 1975 to 1985; and (5) highly localized users were generally excluded - e.g., taxicabs, and local paging
The Arm Motion (AMD) Detection Test
Stroke can lead to sensory deficits that impair functional control of arm movements. Here we describe a simple test of arm motion detection (AMD) that provides an objective, quantitative measure of movement perception related proprioceptive capabilities in the arm. Seven stroke survivors and thirteen neurologically intact control subjects performed the AMD test. In a series of ten trials that took less than 15 minutes to complete, participants used a two-button user interface to adjust the magnitude of hand displacements produced by a horizontal planar robot until the motions were just perceptible (i.e. on the threshold of detection). The standard deviation of movement detection threshold was plotted against the mean and a normative range was determined from the data collected with control subjects. Within this normative space, subjects with and without intact proprioception could be discriminated on a ratio scale that is meaningful for ongoing studies of degraded motor function. Thus, the AMD test provides a relatively fast, objective and quantitative measure of upper extremity proprioception of limb movement (i.e. kinesthesia)
A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean
The development of models of marine ecosystems in the Southern Ocean is becoming increasingly important as a means of understanding and managing impacts such as exploitation and climate change. Collating data from disparate sources, and understanding biases or uncertainties inherent in those data, are important first steps for improving ecosystem models. This review focuses on seals that breed in ice habitats of the Southern Ocean (i.e. crabeater seal, Lobodon carcinophaga; Ross seal, Ommatophoca rossii; leopard seal, Hydrurga leptonyx; and Weddell seal, Leptonychotes weddellii). Data on populations (abundance and trends in abundance), distribution and habitat use (movement, key habitat and environmental features) and foraging (diet) are summarised, and potential biases and uncertainties inherent in those data are identified and discussed. Spatial and temporal gaps in knowledge of the populations, habitats and diet of each species are also identified
Twistor-like Formulation of Super p-Branes
Closed super (p+2)-forms in target superspace are relevant for the
construction of the usual super p-brane actions. Here we construct closed super
(p+1)-forms on a {\it worldvolume superspace}. They are built out of the
pull-backs of the Kalb-Ramond super (p+1)-form and its curvature. We propose a
twistor-like formulation of a class of super p-branes which crucially depends
on the existence of these closed super (p+1)-forms.Comment: 20 pages, plain tex, CTP TAMU-67/93, UG-5/9
Control of light-brown apple moth
Alternatives to lead arsenate for the control of light-brown apple moth, Austrotortrix postvittana (Walk.), were tested in three spray trials in apple orchards in the Stanthorpe district during the 1954-55 season. Programmes incorporating DDD were generally superior to all others, and at the same time avoided the foliage damage and spray residue problems associated with the use of lead arsenate. Two sprays of DDD 0.1 per cent., one applied in late November and the other in late January, are basic for the control of light-brown apple moth
Peoples’ use of, and concerns about, green space networks: A case study of Birchwood, Warrington New Town, UK
Cultural services provided by green space networks and in particular leisure and recreational opportunities are central to the quality of life of those living in urban areas. However, the literature concerned with green space networks has mainly focussed on planning aspects rather than on recreational use. The aim of this study was to evaluate the recreational use of, and concerns about, a naturalistic green space network. The case study location was the naturalistic woodland framework in Birchwood, Warrington, UK, known as Birchwood Forest Park. Non-participant observation and content analysis of local archives were used to collect quantitative and qualitative data. Birchwood Forest Park was used more for leisure activities (52.8%, N = 1,825; i.e. recreation, sports or play) than for utilitarian purposes (47.2%, N = 1,825; i.e. as walking or cycling thoroughfare). However, utilitarian walking (30%, N = 1,825) was the most frequent type of activity observed. The maintenance of the naturalistic woodland framework was the most frequent concern mentioned in the local archives (33.3%, N = 234). This case study suggests that the recreational patterns in, as well as peoples’ concerns about, naturalistic urban landscapes may be a factor of high quality maintenance and associated local aesthetic and cultural perceptions. In developing, planning or managing comprehensive urban green space networks it is important to ensure that natural looking scenes are well maintained and that the local community is culturally connected to such scenes
Studies on codling moth control in the Stanthorpe district, Queensland
During the 1958-59 to 1962-63 seasons, nine trials were conducted to determine the value of new insecticides for the control of Cydia pomonella (L.) in apple orchards of the Stanthorpe district. The important materials under test were azinphos-ethyl, azinphos-methyl, carbaryl, carbophenothion, DDT, dioxathion, ethion, lead arsenate, Mesurol and phosphamidon. Treatments were applied according to predetermined programmes for each season. Other sprays, either alone or in combination with the test materials, were used to control diseases and pests other than codling moth. DDT exercised satisfactory control for codling moth in the 1958-59 trial but there was a marked reduction in efficacy in subsequent trials. Azinphos-ethyl, azinphos-methyl, carbaryl and Mesurol were the better treatments in later trials and have been recommended for codling moth control in the Stanthorpe district
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