Impact of Curb Ramps on the Safety of Persons who are Blind

Curb ramps, which are necessary to enable some persons with physical disabilities to negotiate street crossings, appear to put persons with visual impairments at risk. In 39 percent of 557 approaches to unfamiliar streets via curb ramps, persons who travel using a long cane were unable to detect the streets and to stop before entering them. Street detection was highly associated with the angle of the slope, the abruptness of the change from the approaching sidewalk to the curb ramp, and the location of curb ramps.

Memory for Verbally Presented Routes: A Comparison of Strategies Used by Blind and Sighted People

Experiments were conducted to determine the manner in which congenitally blind and sighted people remember verbal route descriptions. Subjects listened to route descriptions and were then required to perform either spatial or abstract/verbal sentence verifications before finger tracing those routes through a raised line matrix. Route tracing speed and accuracy revealed that for both congenitally blind and sighted subjects, spatial sentence verification interfered more with route memory, even though the spatial verifications were easier than the verbal/abstract verifications for both subject groups when performed alone. The finding indicates that both blind and sighted people transform verbal route descriptions into a spatial imagery form to guide finger tracing. If spatial information is remembered using an imagery strategy, then tactile maps may be better suited than verbal maps for conveying spatial information to blind travelers.

Audible Signage as a Wayfinding Aid: Verbal Landmark versus Talking Signs

This article reports on an evaluation of two technologies—Verbal Landmark and Talking Signs—that provide speech messages to handheld receivers. On all measures, the Talking Signs system proved superior to the Verbal Landmark system.

Synthesis and structural determination of stereoisomers of muscarinic ligands of the (3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicycloalkane type

Methods for the synthesis of each of the four stereoisomers of 6-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1]oc tane (10, 11, 12, and 13) and 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[2.2.1]he ptane (18, 19, 20, and 21), and the two stereoisomers of 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[2.2.2]oc tane (27 and 28) were developed. The relative configuration of the compounds was determined on the basis of previously described 1H NOE experiments, and the absolute configuration of 6-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[3.2.1]oc tanes (10, 11, 12, and 13) and 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicyclo[2.2.2]oc tane (27 and 28) was determined by single crystal X-ray crystallography. Optical purity was determined by capillary electrophoresis (CE) using chiral selectors as trimethyl-beta-cyclodextrin and heparin dissolved in the running buffer. All the 3-(3-propylthio-1,2,5-thiadiazol-4-yl)-1-azabicycles had low nanomolar affinity for muscarinic receptors as determined by displacement of radiolabelled oxotremorine-M (3H-Oxo-M) and pirenzepine (3H-Pz) from cortical rat brain homogenates. The binding assay discriminated between diastereomers, but only a minor degree of enantioselectivity was observed in the binding assays.