Synthesis of isotope-labelled methoxypyrazine compounds as internal standards and quantitative determination of aroma methoxypyrazines in water and wines by solid-phase extraction with isotope dilution-GC-MS /

An efficient way of synthesizing the deuterium labelled analogues of three methoxypyrazine compounds: 2-d3-methoxy-3-isopropylpyrazine, 2-d3-methoxy-3- isobutylpyrazine, and 2-d3-methoxy-3-secbutylpyrazine, has been developed. To confirm that the deuterium labels had been incorporated into the expected positions in the molecules synthesized, the relevant characterization by NMR, HRMS and GC/MS analysis was conducted. Another part of this work involved quantitative determination of methoxypyrazines in water and wines. Solid-phase extraction (SPE) proved to be a suitable means for the sample separation and concentration prior to GC/MS analysis.Such factors as the presence of ethanol, salt, and acid have been investigated which can influence the recovery by SPE for the pyrazines from the water matrix. Significantly, in this work comparatively simple fractional distillation was attempted to replace the conventional steam distillation for pre-concentrating a sample with a relatively large volume prior to SPE. Finally, a real wine sample spiked with the relevant isotope-labelled methoxypyrazines was quantitatively analyzed, revealing that the wine with 10 beetles per litre contained 138 ppt of 2-methoxy-3-isopropylpyrazine. Interestingly, we have also found that 2-methoxy-3-secbutylpyrazine exhibits an extremely low detection limit in GC/MS analysis compared with the detection limit of the other two methoxypyrazines: 2- methoxy-3-isopropylpyrazine and 2-methoxy-3-isobutylpyrazine.

Localization and functional characterization of iridoid biosynthetic genes in Catharanthus roseus /

Catharanthus roseus is the sole biological source of the medicinal compounds vinblastine and vincristine. These chemotherapeutic compounds are produced in the aerial organs of the plant, however they accumulate in small amounts constituting only about 0.0002% of the fresh weight of the leaf. Their limited biological supply and high economical value makes its biosynthesis important to study. Vinblastine and vincristine are dimeric monoterpene indole alkaloids, which consists of two monomers vindoline and catharanthine. The monoterpene indole alkaloids (MIA's) contain a monoterpene moiety which is derived from the iridoid secologanin and an indole moiety tryptamine derived from the amino acid tryptophan. The biosynthesis of the monoterpene indole alkaloids has been localized to at least three cell types namely, the epidermis, the laticifer and the internal phloem assisted parenchyma. Carborundum abrasion (CA) technique was developed to selectively harvest epidermis enriched plant material. This technique can be used to harvest metabolites, protein or RNA. Sequencing of an expressed sequence tagged (EST) library from epidermis enriched mRNA demonstrated that this cell type is active in synthesizing a variety of secondary metabolites namely, flavonoids, lipids, triterpenes and monoterpene indole alkaloids. Virtually all of the known genes involved in monterpene indole alkaloid biosynthesis were sequenced from this library.This EST library is a source for many candidate genes involved in MIA biosynthesis. A contig derived from 12 EST's had high similarity (E'^') to a salicylic acid methyltransferase. Cloning and functional characterization of this gene revealed that it was the carboxyl methyltransferase imethyltransferase (LAMT). In planta characterization of LAMT revealed that it has a 10- fold enrichment in the leaf epidermis as compared to the whole leaf specific activity. Characterization of the recombinant enzyme revealed that vLAMT has a narrow substate specificity as it only accepts loganic acid (100%) and secologanic acid (10%) as substrates. rLAMT has a high Km value for its substrate loganic acid (14.76 mM) and shows strong product inhibition for loganin (Kj 215 |iM). The strong product inhibition and low affinity for its substrate may suggest why the iridoid moiety is the limiting factor in monoterpene indole alkaloid biosynthesis. Metabolite profiling of C. roseus organs shows that secologanin accumulates within these organs and constitutues 0.07- 0.45% of the fresh weight; however loganin does not accumulate within these organs suggesting that the product inhibition of loganin with LAMT is not physiologically relevant. The limiting factor to iridoid and MIA biosynthesis seems to be related to the spatial separation of secologanin and the MIA pathway, although secologanin is synthesized in the epidermis, only 2-5% of the total secologanin is found in the epidermis while the remaining secologanin is found within the leaf body inaccessable to alkaloid biosynthesis. These studies emphasize the biochemical specialization of the epidermis for the production of secondary metabolites. The epidermal cells synthesize metabolites that are sequestered within the plant and metabolites that are secreted to the leaf surface. The secreted metabolites comprise the epidermome, a layer separating the plant from its environment.

Co-operative education and the development of self-esteem, an internal locus of control and work habits

This study compared approximately 50 grade 12 students studying In th~ co-operative education mode with approximately 50 grade 12 students studying in a traditional English course. Measures of self-esteem, locus of control and work habits were compared before and at the conclusion of one semester's involvement in the different programs. Using Coopersmith's Self-Esteem Inventory, the students who had chosen to study in the co-operative education mode scored significantly higher than the students in the traditional course. At the end of the semester, the co-operative education students' scores remained significantly higher than the English students'. Although the test showed no sjgnifi~ant changes in self-esteem. anecdotal reports indicated that co-operative education students had increased self-esteem over the semester. No significant differences in locus of control were observed between the two groups at any time. Significant differences in work habits were observed. While both groups had the same number of absences and the same marks before taking these courses, students who were involved in co-operative education had significantly fewer absences and significantly higher marks than the students studying in the traditional course. Anecdotal reports also indicated an improv~ment in work habits for students who had been involved in co-operative education. Recommendations of the study are for further research to determine more exactly how self-esteem and work habits develop in co-operative education students. Also. students. parents, teachers. and administrators need to be made aware of the success of this program.

EARLY LIFE EXPOSURE TO GENISTEIN AND DAIDZEIN DISRUPTS STRUCTURAL DEVELOPMENT OF REPRODUCTIVE ORGANS IN FEMALE MICE

In mice, exposure to isoflavones (ISO), abundant in soy infant formula, during the first 5 d of life alters structural and functional development of reproductive organs. Effects of longer exposures are unknown. The study objective was to evaluate whether exposure to a combination of daidzein and genistein in the first 10 compared to 5 d of life results in greater adverse effects on ovarian and uterine structure in adult mice. Thirteen litters of 8–12 pups were cross-fostered and randomized to corn oil or ISO (2 mg daidzein + 5 mg genistein/kg body weight/d) for the first 5 or 10 d of life. The 10-d protocol mimicked the period when infants are fed soy protein formula (SPF) but avoids the time when suckling pups can consume the mother’s diet. Body and organ weights and histology of ovaries and uteri were analyzed. There were no differences in the ovary or uterus weight, number of ovarian follicles, number of multiple oocyte follicles, or percent of ovarian cysts with 5 or 10 d of ISO intervention compared to respective controls. The 10-d ISO group had higher body weights from 6 d to 4 mo. of age and a higher percent of hyperplasia in the oviduct than the respective control. Lower numbers of ovarian corpus lutea and a higher incidence of abnormal changes were reported in the uteri of both ISO groups compared to their respective controls. Five- and 10-d exposure to ISO had similar long-lasting adverse effects on the structures of ovaries and uterus in adult mice. Only the 10-d ISO exposure resulted in greater body weight gain at adulthood.

Receipt from W. H. Eckhardt, Pianos, Organs, Sheet Music and Musical Merchandise for piano

Receipt from W. H. Eckhardt, Pianos, Organs, Sheet Music and Musical Merchandise for piano, May 9, 1887.

Drivers of Local Firms’ Focus on Internal R&D in Emerging Economies and Their International Performance

Grounded on the resource-based view of the firm, the study of this thesis investigates the effect of four internal and external factors – engineer intensity, location, affiliation with the government, government funding – on Chinese firms’ decision to either invest in internal R&D activities or external R&D and the effect of this decision on the firms’ international market success. In addition, the moderating role of the presence of foreign firms in China is examined. To understand these relationships, the thesis’ theorization focuses on the issue of how firms can combine optimally the two options – “internal R&D” and “external R&D”. In this regard I juxtapose internal R&D and external R&D and compare their advantages and disadvantages. To test my model, I apply panel data from the Annual Industrial Survey Database provided by the Chinese National Bureau of Statistics. My results show that three of the four investigated factors affect Chinese firms’ resource allocation decisions; and effective resource allocation decisions lead effectively to international market success, strengthened by the presence of foreign firms in China. Moreover the findings bear several theoretical and managerial contributions. First I propose the last dimension of the “VRIO framework” – “organization” – as an endogenous component of the VRIO framework, as my study investigated how firms can effectively combine resources to generate a competitive advantage in terms of international market success. Previous academic literature so far focused on examining whether internal and external R&D are complements or substitutes. My study fills a gap in the literature by investigating the determinants of the efficient combination of the two strategies and the outcome of the combination. One of the managerial implications is that Chinese firms can learn from foreign companies that are present in China.