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Biomedical subjects

B Rogers

Publications and source records attributed to B Rogers.

At least 181 records · Page 10Linked to original sources
PubMed1984

Isochromosome 6p, a unique chromosomal abnormality in retinoblastoma: verification by standard staining techniques, new densitometric methods, and somatic cell hybridization.

Study of chromosome rearrangements in retinoblastoma tumors revealed that all tumors contained either an unusual isochromosome and/or extra copies of chromosome 1q. Extra copies of chromosome 1q occur in many malignancies. The pattern of G-bands suggested that the isochromosome was derived from either the short arm of chromosome 6, i(6p), or the long arm of chromosome 17, i(17q). Standard staining techniques using G-, C-, Q-, and R-banding; high resolution G-banding; and density profile analysis were consistent with the characteristic isochromosome of retinoblastoma being i(6p), rather than i(17q). This conclusion was substantiated by the analysis of segregants derived from retinoblastoma X mouse hybrid cells which had been grown in bromodeoxyuridine to select for loss of chromosome 17. The unique isochromosome was not lost under these conditions confirming that it is an i(6p) rather than an i(17q). The i(6p) abnormality has not been observed frequently in other tumors, but occurs in 60% of retinoblastoma tumors. Thus, although the mutation predisposing to retinoblastoma is known to map at 13q14, somatic amplification of genes on 1q and 6p may play a role in the pathogenesis of this tumor.

Animals↗
PubMed1983

Community hospital oncology program: an organizational and group process perspective.

The STRCP has successfully completed the CHOP planning phase with medical, nursing, rehabilitation/support guidelines lines as one component of the program. With implementation, data is being collected on guideline use and compliance as well as active PMP updating. An evaluation plan is being implemented. Hopefully with these and other activities, the role of the CHOP as a model for cancer control activities in the community will be clearly defined.

Cancer Care Facilities↗
PubMed1982

Similarities between motion parallax and stereopsis in human depth perception.

Random dot techniques were used to investigate the human visual system's sensitivity to sinusoidal depth modulations specified by motion parallax information. Thresholds for perceiving depth were found to be smallest when the spatial frequency of the depth corrugations was between 0.2 and 0.5 c/deg visual angle. These data were compared with the equivalent thresholds for perceiving depth corrugations specified by binocular disparity using similar apparatus and psychophysical procedures. The similarity between the sensitivity functions is suggestive of a closer relationship between the two systems than has previously been thought.

Depth Perception↗
PubMed1982

Simultaneous and successive contrast effects in the perception of depth from motion-parallax and stereoscopic information.

Prolonged inspection of a three-dimensional corrugated surface resulted in a successive contrast effect, or aftereffect, of depth, whereby a subsequently-viewed physically-flat test surface appeared to be corrugated in depth with the opposite phase to the adapting surface. The aftereffect occurred both when the depth was specified by motion parallax, in the absence of all other sources of depth information, and when it was specified solely by stereoscopic information. The depth aftereffect was measured by 'nulling' the apparent depth in the test surface with physical relative motion or binocular disparity until the test surface appeared flat. Up to 70% of the depth in the adapting surface was necessary to null the aftereffect. Simultaneous contrast effects in the perception of three-dimensional surfaces were used to investigate the spatial interactions that exist in the processing of motion-parallax and stereoscopic information. A physically vertical surface appeared to slope in depth in the opposite direction to the slope of a surrounding surface. In this case up to 50% of the slope of the inducing surface was necessary to null the contrast effect. Similar results were again obtained for motion-parallax and stereoscopic depth.

Adaptation, Ocular↗
PubMed1980

Physical/chemical and microbiological analyses of dusts at a resource recover plant.

Airborne dusts at a resource recovery pilot plant were sampled and analyzed to determine physical, chemical and microbiological characteristics. The sampling device was a multi-stage impactor equipped with a pre-collector. Dusts are primarily fibrous organic materials, predominantly of nonrespirable size. Microbiological aerosol concentrations are reported and discussed.

Air Microbiology↗
PubMed1980

Voluntary help.

Explore the source record for details and available documents.

United Kingdom↗
PubMed1979

Motion parallax as an independent cue for depth perception.

The perspective transformations of the retinal image, produced by either the movement of an observer or the movement of objects in the visual world, were found to produce a reliable, consistent, and unambiguous impression of relative depth in the absence of all other cues to depth and distance. The stimulus displays consisted of computer-generated random-dot patterns that could be transformed by each movement of the observer or the display oscilloscope to simulate the relative movement information produced by a three-dimensional surface. Using a stereoscopic matching task, the second experiment showed that the perceived depth from parallax transformations is in close agreement with the degree of relative image displacement, as well as producing a compelling impression of three-dimensionality not unlike that found with random-dot stereograms.

Cues↗