Role of burst activity in attribute detection by visual neurons of the cat cortex

The temporal structure of neuronal responses has been investigated in the Clare-Bishop area of the cat cortex. Stationary and moving slit and moving spot have been used for stimulation. It was found that orientational and directional selectivity was determined mainly by the number of clustered impulses and the number of clusters. A closed-loop model for features detection which is able to interpret clustered activity is presented.     

Clinical effectiveness in radiologic technology students: an empirical perspective

This article describes two studies that examine the nature of effective clinical performance among radiologic technology students. The first study includes the perspective of staff technologists on student performance, while the second study includes the perspective of clinical instructors, important dimensions of performance that are identified include organization, relationship with peers and staff, relationships with patients, flexibility, and initiative. These dimensions are linked to specific student behaviors in clinical practice.     

General evaluation of the patient with alopecia

The evaluation of the patient with alopecia is a multistep process that comprises obtaining a good medical history, performing the clinical examination with a special emphasis on the examination of cut and plucked hair, doing a scalp biopsy, and ordering appropriate laboratory studies. Genetic counseling may be given if it is requested.     

Activating effect of substance P on nerve tissue in culture

The effect of substance P on organotypic culture of rat sympathetic ganglia and spinal cord was studied. Substance P was able to stimulate the fibre outgrowth from explant, to increase the numbers of glial and fibroblasttypic cells in ganglia growth zone. The effect was observed in the range from 10(-5) to 10(-12) M (for sympathetic ganglia) and from 10(-5) to 10(-14) M (for spinal cord culture). It is suggested that substance P can be used as a nonspecific growth factor for peripheral and central nervous tissue.     

Increased prevalence of apolipoprotein E2 in patients with retinitis pigmentosa

Apolipoprotein E isoforms were determined in 139 unrelated patients with retinitis pigmentosa (RP). When compared to prevalence rates for the general population in Germany, an increased prevalence was observed for phenotypes E2/E2: 10.1 vs. 1.0% (p less than 0.001), E2/E3: 19.4 vs. 12.0% (p less than 0.05), and E2/E4: 5.8 vs. 1.5% (n.s.), while the prevalence appeared to be reduced for phenotypes E3/E3: 48.9 vs. 59.8% (n.s.) E3/E4: 13.7 vs. 22.9% (p less than 0.05), and E4/E4: 2.2 vs. 2.8% (n.s.). These findings suggest that genetically determined abnormalities of plasma lipoprotein metabolism may be associated with some forms of RP.