Graphs and colored photographs included. / Thesis (M.Sc.D.)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1980 (Endodontics) / Bibliography: leaves 391-418.

Artemisinin is a potent antimalarial sesquiterpene lactone produced and stored in the glandular trichomes (GLTs) of Artemisia annua. Although they produce no artemisinin, nor any of the precursor compounds, A. annua roots appear to have a regulatory effect on production of the terpene in leaves. However, more information is needed to define the role of the roots in artemisinin production in the plant. Grafting among three cultivars was used to measure phenotypic responses: SAM, and #15 cultivars both have GLTs, but produce artemisinin at 1.49% and 0.57% DW, respectively; GLS cultivar produces neither GLTs nor artemisinin. Compared to ungrafted plants, all self-grafts, e.g. SAM/SAM (scion/rootstock), increased scion artemisinin probably from grafting stress. SAM/#15 grafts yielded less artemisinin than SAM/SAM, but more than either #15/#15 or ungrafted #15 and SAM suggesting rootstock inhibition of the scion. SAM/SAM also had more artemisinin than #15/SAM, which was also greater than either #15/#15 or ungrafted #15 and SAM. The #15/SAM graft also produced more artemisinin than SAM/#15, and with the other grafting results suggested that SAM roots were stimulating artemisinin production in the #15 scion. There was no appearance of either GLTs or artemisinin when GLS scions were grafted to SAM indicating that GLTs had to be present to receive putative signals from SAM rootstocks. Furthermore, artemisinic acid and arteannuin B were only present in SAM scions and not scions of #15 suggesting a block in one of the side pathways of artemisinin biosynthesis. Other artemisinic metabolites, total flavonoids, and GLTs numbers were also measured. The various phenotypes were analyzed several months after grafting indicating a persistent change and suggesting a possible epigenetic alteration of the scion. This study will provide fundamental information regarding the role that roots play in the production of artemisinin in the shoots of A. annua.

We place a differential on $\dot\UC_{\mathfrak{sl}_3}^+$ and show that $\dot\UC_{\mathfrak{sl}_3}^+$ is Fc-filtered. This gives a categorification of the positive half of quantum $\sl_3$ at a prime root of unity.

No description available.

Thesis (M.D.S.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 83-102) Also available in print.

Thesis (Ph. D.)--Oregon State University, 1983. / Typescript (photocopy). Includes bibliographical references (leaves 32-37). Also available on the World Wide Web.

In this thesis, a second-order low pass square root domain filter (SRD filter) based on operational transconductors amplifiers (OTAs) is presented. The SRD filter consists of two translinear filters and four OTAs. Because the OTA has small voltage swings, which may violate the large signal natural of the SRD filter. We investigate the dynamic range of this compact SRD filter with different quality factor(Q). The circuit has fewer numbers of transistors and operate in low voltage, therefore, it has less power consumption and less chip area. The circuit has been fabricated with 0.35£gm CMOS technology. It operates with a supply voltage 1.5V and the biasing current varies from 10uA to 80uA. Measurement results lts show that Im/I0≥40% when the external capacitance C is 3.5pF¡B7pF and Im/I0≥53% when the external capacitance C is 3pF¡B8.5pF. The cutoff frequency of the filter can be tuned from 1.24MHz to 5.53MHz when the external capacitance C is 3.5pF¡B7pF and the cutoff frequency can be tuned from 900KHz to 4.46MHz when the external capacitance C is 3pF¡B8.5pF. The total harmonic distortion is 0.908% and the power consumption is 506£gW.

An ultrametric field is a field that is locally compact as a metric space with respect to a non-archimedean absolute value. The main topic of this dissertation is to study roots of polynomials over such fields. If we have a univariate polynomial with coefficients in an ultrametric field and non-vanishing discriminant, then there is a bijection between the set of roots of the polynomial and classes of roots of the same polynomial in a finite ring. As a consequence, there is a ball in the polynomial space where all polynomials in it have the same number of roots. If a univariate polynomial satisfies certain generic conditions, then we can efficiently compute the exact number of roots in the field. We do that by using Hensel's lemma and some properties of Newton's polygon. In the multivariate case, if we have a square system of polynomials, we consider the tropical set which is the intersection of the tropical varieties of its polynomials. The tropical set contains the set of valuations of the roots, and for every point in the tropical set, there is a corresponding system of lower polynomials. If the system satisfies some generic conditions, then for each point w in the tropical set the number of roots of valuation w equals the number roots of valuation w of the lower system. The last result enables us to compute the exact number of roots of a polynomial system where the tropical set is finite and the lower system consists of binomials. This algorithmic method can be performed in polynomial-time if we fix the number of variables. We conclude the dissertation with a discussion of the feasibility problem. We consider the problem of the p-adic feasibility of polynomials with integral coefficients with the prime number p as a part of the input. We prove this problem can be solved in nondeterministic polynomial-time. Furthermore, we show that any problem, which can be solved in nondeterministic polynomial-time, can be reduced to this feasibility problem in randomized polynomial-time.

No description available.

No description available.