Showing papers by "David A. Jackson published in 1982"
TL;DR: In this article, a heterodyne signal recovery scheme for interferometric sensors based on frequency ramping of the laser diode source is described, and signals in the range 10?4 to 6 rad have been recovered, the system being linear over 5 decades.
Abstract: A heterodyne signal recovery scheme for interferometric sensors based on frequency ramping of the laser diode source is described. Using a PLL detector, signals in the range 10?4 to 6 rad have been recovered, the system being linear over 5 decades.
281 citations
TL;DR: It is concluded not only that transcription and replication of viral RNA are nuclear, but also that they occur at fixed sites in the nucleus.
Abstract: We have recently shown that cellular RNA is synthesized at a sub-nuclear structure, the nuclear cage1, which contains proteins also found in other structures called variously the nuclear pore complex, lamina, envelope and matrix2–6. Is the RNA of an exogenous virus also synthesized at the cage? We chose to study influenza virus as it is unusual in its requirement for a host cell nucleus even though there are no cellular counterparts to the transcription of the infecting negative strands of genomic influenza RNA, nor to the replication of the resulting positive RNA strands to form new virion RNA. The cellular sites of these processes have not yet been definitively demonstrated7,8. We now show that nascent viral transcripts are closely associated with the cage and we conclude not only that transcription and replication of viral RNA are nuclear, but also that they occur at fixed sites in the nucleus.
143 citations
TL;DR: In this paper, a sensitive accelerometer is described, in which singlemode optical fibre is used to detect acceleration induced dimensional changes in a compliant cylinder, which can be tailored through a suitable choice of the compliant material employed.
Abstract: A sensitive accelerometer is described, in which single-mode optical fibre is used to detect acceleration induced dimensional changes in a compliant cylinder. The device sensitivity and overall frequency response can be tailored through a suitable choice of the compliant material employed. Sensitivities better than 1000 rad/g (10 m/s2) are exhibited using rubber as the compliant material.
61 citations
TL;DR: In this article, the feasibility of a passive compensation scheme for the SMFI was investigated using a conventional Mach-Zehnder interferometer, and the authors showed that minimum detectable phase sensitivities less than 10?6 rad are achievable at frequencies > 1 kHz.
Abstract: The feasibility of a passive compensation scheme for the SMFI is investigated using a conventional Mach-Zehnder interferometer. Problems normally associated with active feedback stabilisation are eliminated, resulting in infinite range compensation. Minimum detectable phase sensitivities less than 10?6 rad are achievable at frequencies > 1 kHz with the interferometer working in an unshielded environment.
35 citations
TL;DR: In this article, a miniature laser Doppler velocimeter (LDV) using a single-mode solid-state semiconductor laser is described, where current-induced output frequency modulation of the laser output, combined with an unbalanced interferometer, is used to provide direction sensing.
Abstract: A miniature laser Doppler velocimeter (LDV) using a single-mode solid-state semiconductor laser is described. Current-induced output frequency modulation of the laser output, combined with an unbalanced interferometer, is used to provide direction sensing.
20 citations
01 Jan 1982
18 citations
TL;DR: In this article, the use of a spherical mirror Fabry-Perot (confocal) interferometer as an optical displacement sensor is described, which incorporates a simple electronic servo to maintain the inter-ferometer at an operating point of maximum sensitivity.
Abstract: The use of a spherical mirror Fabry–Perot (confocal) interferometer as an optical displacement sensor is described. The device incorporates a simple electronic servo to maintain the interferometer at an operating point of maximum sensitivity. Applications as vibration and acceleration sensors are forseen, with sensitivities for sinusoidal accelerations of 10−3 μg achievable at 10 Hz.
4 citations
TL;DR: The analysis was undertaken because the assertion had been made that the association among indicators was high, particularly within major social area dimensions, and consequently, a few indicators could be used to provide the information contained in the system, and it failed to support this thesis.
Abstract: This paper explores the extent of redundancy among the small area indicators of the 1970 Mental Health Demographic Profile System (MHDPS). Redundancy is equated with interindicator Pearson correlations equal to or greater than 0.80 for the census tracts within six metropolitan counties. The analysis was undertaken because the assertion had been made that the association among indicators was high, particularly within major social area dimensions, and consequently, a few indicators could be used to provide the information contained in the system. The analysis failed to support this thesis. The paper concludes by making a case for a judgmental selection of items and briefly reviewing the 1980 MHDPS.
3 citations