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Increasing consumer awareness of food safety issues requires the development of highly sophisticated techniques for the authentication of food commodities. The food products targeted for falsification are either products of high commercial value or those produced in large quantities. For this reason, the present investigation is directed toward the characterization of coffee samples according to geographical origin attributes. In addition, the current examination is focused on the identification of particular marker compounds that compose the volatile and semivolatile aroma fraction of flavoured and dessert coffees. The conducted research involved the development of a rapid headspace solid phase microextraction (HS-SPME) – gas chromatography – time-of-flight mass spectrometry (GC-TOFMS) method for the verification of geographical origin traceability of coffee samples. As opposed to the utilization of traditional univariate optimization methods, the current study employs the application of multivariate experimental designs to the optimization of extraction-influencing parameters. Hence, the two-level full factorial first-order design aided in the identification of two influential variables: extraction time and sample temperature. The optimum set of conditions for the two variables was 12 min and 55 oC, respectively, as directed by utilization of the Doehlert matrix and response surface methodology. The high-throughput automated SPME procedure was completed under optimized conditions by implementing a single divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) metal fiber with excellent properties of durability, which ensured the complete analysis of coffee samples in sequence. The coffee sample originating from an authentic Brazilian coffee producing region and characterized by rich volatile and semivolatile chromatographic profiles was selected as a reference starting point for data evaluation. The combination of the retention index (RI) system using C8-C40 alkanes and the mass spectral library search was utilized for the confirmation of analyte identity in this reference sample. Twenty-nine volatile and semivolatile compounds selected across the wide range of GC chromatogram were then evaluated in terms of chromatographic peak areas for all samples that are to be submitted to this classification study. The semiquantitative results were submitted to statistical evaluation, namely principal component analysis (PCA) for the establishment of corresponding geographical origin discriminations.

This thesis examines some of the challenges involved with using FTIR spectroscopy for cancer detection including sample preparation and correcting for distortion from cell scattering. Sample preparation affects the spectra differently depending on the cell type, and can lead to significant changes in cancer biomarkers for a given cell type. Biomarkers derived from specific cancer types under one sample preparation are not reliable for other cancer types, and may not be suitable for the same cancer type using a different sample preparation. Cell scattering can also significantly affect the cell spectra, and as a result, correcting for the cell scattering distortion leads to changes in the biomarkers. For reliable cancer detection controlling variability is critical, especially in the complex spectra of biological samples. Standard sample preparation methods and scattering correction post-processing could improve comparison of cancer detection methods.

Increasing consumer awareness of food safety issues requires the development of highly sophisticated techniques for the authentication of food commodities. The food products targeted for falsification are either products of high commercial value or those produced in large quantities. For this reason, the present investigation is directed toward the characterization of coffee samples according to geographical origin attributes. In addition, the current examination is focused on the identification of particular marker compounds that compose the volatile and semivolatile aroma fraction of flavoured and dessert coffees. The conducted research involved the development of a rapid headspace solid phase microextraction (HS-SPME) – gas chromatography – time-of-flight mass spectrometry (GC-TOFMS) method for the verification of geographical origin traceability of coffee samples. As opposed to the utilization of traditional univariate optimization methods, the current study employs the application of multivariate experimental designs to the optimization of extraction-influencing parameters. Hence, the two-level full factorial first-order design aided in the identification of two influential variables: extraction time and sample temperature. The optimum set of conditions for the two variables was 12 min and 55 oC, respectively, as directed by utilization of the Doehlert matrix and response surface methodology. The high-throughput automated SPME procedure was completed under optimized conditions by implementing a single divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) metal fiber with excellent properties of durability, which ensured the complete analysis of coffee samples in sequence. The coffee sample originating from an authentic Brazilian coffee producing region and characterized by rich volatile and semivolatile chromatographic profiles was selected as a reference starting point for data evaluation. The combination of the retention index (RI) system using C8-C40 alkanes and the mass spectral library search was utilized for the confirmation of analyte identity in this reference sample. Twenty-nine volatile and semivolatile compounds selected across the wide range of GC chromatogram were then evaluated in terms of chromatographic peak areas for all samples that are to be submitted to this classification study. The semiquantitative results were submitted to statistical evaluation, namely principal component analysis (PCA) for the establishment of corresponding geographical origin discriminations.

No description available.

No description available.

Since federal legislation in 1917 and the widespread program growth in the 1930’s, agricultural mechanics has been a major part of the high school agricultural science and technology curriculum. Local programs integrated individual problem -solving, practical applications of mathematics and technical science skills in to the curriculum. However, recent financial constraints and a perceived lack of interest have led to reductions in course offerings in agricultural mechanics in some universities that are responsible for the maintenance and future of the disciplinary area. These curricular issues gave rise to a research problem examining the perspectives of successful agricultural science and technology teachers of agricultural mechanics and the education and experiences that were associated with their success. This study used qualitative measures to identify factors that enabled certain agricultural science and technology teachers who were more noted in teaching of agricultural mechanics to be more successful than their peers. It examined factors that motivated teachers to excel and examined the influences that determined what portions of the curriculum were included or deleted. Finally, this study focused on the recommendations of experts regarding improvements for future teaching of high school agricultural mechanics. Data were collected, analyzed, and reported using accepted a qualitative protocol to develop emergent themes. Successful agricultural science and technology teachers agreed that their undergraduate course work did not adequately prepare them to teach the current curriculum. Unanimously, the respondents expressed a concern for the lack of depth, scope, and technical skills in agricultural mechanics currently being taught to future agricultural science teachers. This concern for the pre-service curriculum led teachers to agree that the three-week agricultural mechanics certification workshop is essential for successful instruction of agricultural mechanics. Furthermore, teachers espoused a formal mentoring program to aid the professional development of agricultural science and technology teachers. The respondents alluded to the need for more quality workshops on the part of the Texas Education Agency, the VATAT professional organization and the agricultural education community as a whole to improve the quality, scope, depth, and technical skills in the instruction of Agricultural Science and Technology in the high schools of Texas.

The purpose of this study was to determine the initial and actual professional goals, the changes in initial and actual professional goals and the reasons for this change of the different Texas A&M University veterinary medicine graduates from 1990-2002, how satisfied the selected veterinary medicine graduates were with their veterinary medicine college educational preparation from the graduating classes representing 1990-2002, and to determine if the top ranked courses have changed among the veterinary medicine graduates from 1990 until 2002. The descriptive research design included a questionnaire that was provided to Texas A&M University’s College of Veterinary Medicine graduates one year following graduation. Data was collected from the group of veterinarians who graduated during 1990-2002. Findings indicate that since 1990, veterinary students have entered the College of Veterinary Medicine with a predominant interest in small animal or mixed practices. This study shows the stability of the career choices with mixed and small being consistently the first and second choices over the span of years studied. No apparent trend appeared from the data that identifies one compelling reason for changing jobs. The overall satisfaction for the educational preparation on their education is 90% or more. The top-ranked basic science courses have not changed among the veterinary medicine graduates during the selected period and these are: “Pharmacology,” “Gross Anatomy,” “Endocrine,” “Parasitology,” “Physiology” and “Clinical Pathology.” The top-ranked clinical disciplines are not as clearly ranked as the basic sciences. They are: “Anesthesiology,” “Gastroenterology,” “General Surgery,” “Internal Medicine,” “Oncology,” and “Radiology.” No apparent trend appeared from the data that identifies one or the other of these categories becoming more popular over time.

This study examined the influence of career preparation courses on student achievement at MacArthur High School, San Antonio, Texas. MacArthur is the only high school in the district to use the 6.5 scaled registrar’s grade point average (RPA) system, as opposed to the standard 4.0 scaled grade point average. Final computations were converted to the standard 4.0 scale for uniformity. The intent of the study was to determine if there was a relationship between enrollment in career preparation courses and grade point averages, absenteeism, and dropout rates. Moreover, the study sought to determine the relationship between students enrolled in career preparation courses and students not enrolled within these three areas of investigation. Data were collected from the student records of the population of the study, which consisted of 532 students, and was used in conjunction with descriptive and co-relational statistics, including ANOVAS and Scheffes. The results of this study support that career preparation students in the study possessed a higher grade point average. Additionally, this study supported the literature review regarding career preparation student absenteeism and dropout rates. The career preparation students spend more time at school, which enhances their propensity for learning. The study also compared career preparation students to students not enrolled in career preparation courses by grade point average at MacArthur High School. The results of this portion of the study showed that the non-career preparation students, the health occupation students, as well as the trade and industry students, all possess a higher grade point average than do the business and marketing students. This is attributable for the most part to skill sets needed for scientific definitions, higher math skills, and enhanced scientific knowledge. Further study should be done to ascertain the extent of individual factors in determining success in other district high schools.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains viii, 72 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 46-48).