The discrimination and association of float glass and the quantitative analysis of liquids from aerosols and microdrops using laser induced breakdown spectroscopy

Glass is a common form of trace evidence found at many scenes of crimes in the form of small fragments. These glass fragments can transfer to surrounding objects and/or persons and may provide forensic investigators valuable information to link a suspect to the scene of a crime. Since the elemental composition of different glass sources can be very similar, a highly discriminating technique is required to distinguish between fragments that have originated from different sources. ^ The research presented here demonstrates that Laser Induced Breakdown Spectroscopy (LIBS) is a viable analytical technique for the association and discrimination of glass fragments. The first part of this research describes the optimization of the LIBS experiments including the use of different laser wavelengths to investigate laser-material interaction. The use of a 266 nm excitation laser provided the best analytical figures of merit with minimal damage to the sample. The resulting analytical figures of merit are presented. The second part of this research evaluated the sensitivity of LIBS to associate or discriminate float glass samples originating from the same manufacturing plants and produced at approximately the same time period. Two different sample sets were analyzed ranging in manufacturing dates from days to years apart. Eighteen (18) atomic emission lines corresponding to the elements Sr, K, Fe, Ca, Al, Ba, Na, Mg and Ti, were chosen because of their detection above the method detection limits and for presenting differences between the samples. Ten elemental ratios producing the most discrimination were selected for each set. When all the ratios are combined in a comparison, 99% of the possible pairs were discriminated using the optimized LIBS method generating typical analytical precisions of ∼5% RSD. ^ The final study consisted of the development of a new approach for the use of LIBS as a quantitative analysis of ultra-low volume solution analysis using aerosols and microdrops. Laser induced breakdown spectroscopy demonstrated to be an effective technique for the analysis of as low as 90 pL for microdrop LIBS with 1 pg absolute LOD and 20 µL for aerosol LIBS with an absolute LOD of ∼100 fg.^

Characteristics of the Commission on Accreditation of Allied Health Education Programs or National Athletic Trainers' Association -accredited athletic training programs associated with first -attempt passing rates on the NATABOC examination

Athletic training is an allied health profession recognized by the American Medical Association requiring certification by examination. There are two routes towards certification as an athletic trainer: attending a university with an accredited athletic training program or with an internship program By 2004, the only route towards certification will be by attending a Commission on Accreditation of Allied Health Education Programs (CAAHEP) or National Athletic Trainers' Association (NATA) accredited athletic training program. CAAHEP looks at passing rates on the NATA Board of Certification (NATABOC) examination when granting accreditation. This study examined characteristics of programs associated with first time passing rates. ^ Directors from 39 CAAHEP or NATA accredited athletic training programs completed a descriptive 17-question survey regarding academic characteristics, faculty characteristics, and program characteristics. Analysis used Spearman's rho correlation coefficient, with significance of p = <.05. Four program directors were interviewed to gather additional insight. ^ There were three program characteristics that showed a significant positive association with first attempt passing rates: the number of full-time and part-time approved clinical instructors (ACIs), and the number of students in the program. Further investigation found a statistically significant association between a low ratio of ACIs to athletic training students and first time passing rates. ACIs are certified athletic trainers (ATCs) who have received special training in order to supervise athletic training students. CAAHEP mandates a 1:8 ratio of ATCs to athletic training student. This study showed that a smaller ratio of ATC to student in combination with ACI training was significantly associated with higher first time passing rates. The number of courses above the required 13 delineated by the Education Council showed a significant negative association with first attempt passing rates. ^ Universities seeking or maintaining accreditation should incorporate characteristics associated with a higher passing rate on the NATABOC examination. Characteristics include utilizing a large number of full-time and part-time ACIs, admitting a large number of students into the program while maintaining a low ACI to athletic training student ratio, and offering curricula that focuses on the 13 courses that have been deemed relevant to the athletic training curriculum by the Education Council. ^