Historical and current atmospheric deposition to the epilithic lichen Xanthoparmelia in Maricopa County, Arizona.

Spatial patterns of atmospheric deposition of trace elements to an epilithic lichen were assessed using a spatial grid of 28 field sites in 1998 throughout Maricopa County, Arizona, USA. In addition, samples of Xanthoparmelia spp. from Arizona State University lichen herbarium material (1975-1976) was utilized for a limited number of sites in order to explore temporal trends. The lichen material was cleaned, wet digested and analyzed by ICP-MS for a suite of elemental concentrations [antimony (Sb), cadmium (Cd), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu), dysprosium (Dy), europium (Eu), gadolinium (Gd), gold (Au), holmium (Ho), lead (Pb), lutetium (Lu), neodymium (Nd), nickel (Ni), palladium (Pd), platinum (Pt), praseodymium (Pr), samarium (Sm), scandium (Sc), silver (Ag), terbium (Tb), thulium (Tm), tin (Sn), uranium (U), ytterbium (Yb), yttrium (Y), and zinc (Zn)]. Cluster analysis and principal component analysis suggest three major factors, which, depending on regional aerosol fractionation, explain most of the variation in elemental signatures: (1) a group of widely distributed rare earth elements (2) a highly homogenous Co, Cr, Ni, and Sc component representing the influence of mafic rocks, and (3) anthropogenic emissions. Elemental concentrations in Maricopa County lichens were generally comparable to those reported for relatively unpolluted areas. Only highly urbanized regions, such as the greater Phoenix Metropolitan Area and the NW corner of the county, exhibited elevated concentrations for Zn, Cu, Pb, and Cd. Lead levels in lichens have fallen over the last 30 years by 71%, while Zn concentrations for some regions have increased by as much as 245%. From the spatial pattern of elemental deposition for Cd, Cu, Ni, Pr, Pb, and Cu, we infer that agriculture, mining, industrial activities, and traffic probably are the major air pollutant sources in Maricopa County.

Rapid diagnosis of respiratory syncytial virus infection by using Pernasal swabs.

The sensitivity and specificity of direct immunofluorescence microscopy performed on Pernasal swab specimens and compared with those of nasopharyngeal aspirates were 93 and 99%, respectively. Posterior nasopharyngeal swabs applied immediately to microscope slides allow a rapid and simple screening procedure for the diagnosis of acute respiratory syncytial virus infections.

Experiences with a veterinary preceptorial program.

An off-campus, practitioner-supervised training (preceptorial) program for veterinary students at Michigan State University was developed and introduced in the fall of 1972. The program was designed to meet the needs of students concentrating on food animal medicine. It has enabled senior students to receive degeee credit for on-the-job experience with practitioners. Students opting for the program gain experience and knowledge in segments of clinical veterinary medicine that are most available with off-campus practitioners. Exposure of students to the clinical abilities of private practitioners, the case method of study, and diagnostics in a realistic environment are the goals of the program. The program has afforded faculty members and private practitioners meaningful insights into the changing face of veterinary education. Indeed, the consensus of the faculty in the Department of Large Animal Surgery and Medicine at Michigan State University is that an off-campus curriculum. Participating students and practitioners report that the program has been successful and is worthy of expansion and continuation. Both groups rate the program favorably and believe it has been a worthwhile teaching-learning experience.