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At least 37 records · Page 2Linked to original sources
PubMed1993

Longitudinal changes in hearing ability among Swedish conscripts.

An analysis of a military database of about 36,000 tone audiograms from male Swedish conscripts aged 18 to 19 and recorded from 1969 to 1977 demonstrates a successively decreasing prevalence of hearing loss during this period. This might reflect improved therapy during the 1950s and 1960s of ear disorders causing hearing loss in small children. If observations in other studies on a reverse trend during the 1980s are confirmed, they indicate, together with the present study, that around 1980 young people began to be harmfully exposed to an environmental factor causing hearing loss. If this is the case, the causative factor would probably be non-occupational exposure to electronically amplified sounds from loudspeakers and headphones.

Acoustic Stimulation↗
PubMed2006

Harmonic lasing in a free-electron-laser amplifier.

A method is demonstrated that allows a planar wiggler high-gain Free-Electron-Laser (FEL) amplifier to lase so that the interaction with an odd harmonic of the radiation field dominates that of the fundamental. This harmonic lasing of the FEL is achieved by disrupting the electron interaction with the usually dominant fundamental while allowing that of a harmonic interaction to evolve unhindered. The disruption is achieved by a series of relative phase changes between the electrons and the ponderomotive potentials of both the fundamental and harmonic fields. Such phase changes are relatively easy to implement and some current FEL designs would require little or no structural modification to test the scheme.

Journal Article↗
PubMed1989

Modified Box-Cox transform for modulating the dynamic range of flow cytometry data.

We describe an algorithm, Vout = Integer ([2(12)-1/2(12 lambda)-1] V lambda in-1) + 1; lambda greater than 0 based upon Box-Cox transformations as an alternative to nonlinear electronic amplifiers to expand or compress high- or low-amplitude flow cytometer-derived signals. If the indexing parameter lambda less than 1, input channels in the high-amplitude input range are compressed in the output range as occurs when an electronic logarithmic amplifier is used. However, if lambda greater than 1, input channels in the low-amplitude input range are compressed in the output range as occurs when an electronic power amplifier is used. Our modified Box-Cox transform can be implemented either during data collection or off-line for the transformation of previously collected raw data. The transform is the equivalent of an infinite class of nonlinear amplifiers. As the transform is implemented in software, it does not suffer from many of the disadvantages of nonlinear electronic amplifiers.

Algorithms↗
PubMed1985

The electronic pantograph: amplifier couples microscope stage to X-Y plotter.

A system is described that allows the X-Y movement of a microscope stage to be coupled to the movement of the pen of a X-Y plotter. Linear potentiometers are displaced by any X- or Y-axis movement of the microscope's stage and are connected to a DC amplifier which provides a varying DC voltage to the inputs of a X-Y plotter. The pen of the X-Y plotter becomes yoked to the movement of the stage and it is possible to draw or count the image that is being viewed at magnifications which are independent of those used for observation. The coupling DC amplifier provides a DC offset voltage at all gain settings of the pantograph which is sufficient to reposition the pen of the X-Y plotter in the center of the plotter's platen, regardless of the location of the specimen on the microscope slide. The electronic pantograph overcomes the limitations of a camera lucida, and is well suited for analyzing connectional neuroanatomical material with bright- and darkfield, polarized light or florescent illumination at a reasonable price and without the complexity and hardware requirements of a computerized system.

Animals↗