An Analytical Model for Virtual Topology Reconfiguration in Optical Networks and A Case Study

An analytical model for Virtual Topology Reconfiguration (VTR) in optical networks is developed. It aims at the optical networks with a circuit-based data plane and an IPlike control plane. By identifying and analyzing the important factors impacting the network performance due to VTR operations on both planes, we can compare the benefits and penalties of different VTR algorithms and policies. The best VTR scenario can be adaptively chosen from a set of such algorithms and policies according to the real-time network situations. For this purpose, a cost model integrating all these factors is created to provide a comparison criterion independent of any specific VTR algorithm and policy. A case study based on simulation experiments is conducted to illustrate the application of our models.

NUMERICAL AND ANALYTICAL VERIFICATION OF A MULTISCALE COMPUTATIONAL MODEL FOR IMPACT PROBLEMS IN HETEROGENEOUS VISCOELASTIC MATERIALS WITH EVOLVING DAMAGE

Composites are engineered materials that take advantage of the particular properties of each of its two or more constituents. They are designed to be stronger, lighter and to last longer which can lead to the creation of safer protection gear, more fuel efficient transportation methods and more affordable materials, among other examples. This thesis proposes a numerical and analytical verification of an in-house developed multiscale model for predicting the mechanical behavior of composite materials with various configurations subjected to impact loading. This verification is done by comparing the results obtained with analytical and numerical solutions with the results found when using the model. The model takes into account the heterogeneity of the materials that can only be noticed at smaller length scales, based on the fundamental structural properties of each of the composite’s constituents. This model can potentially reduce or eliminate the need of costly and time consuming experiments that are necessary for material characterization since it relies strictly upon the fundamental structural properties of each of the composite’s constituents. The results from simulations using the multiscale model were compared against results from direct simulations using over-killed meshes, which considered all heterogeneities explicitly in the global scale, indicating that the model is an accurate and fast tool to model composites under impact loads. Advisor: David H. Allen

Scientometric Study of Doctoral Dissertations in Biochemistry in the University of Kerala, India

Biochemistry is the most fascinating subject as it deals with the chemical language of life. The ultimate goal of biochemistry is to describe the phenomena that distinguish living from non-living in the language of chemistry and physics. Researchers in biochemistry use specific techniques native to biochemistry, but increasingly combine these with techniques and ideas from genetics, molecular biology and biophysics. In India at present around 75,000 students are enrolled in research and nearly 11,000 are awarded PhDs every year, of which 50 percent are from science and technology disciplines. Theses and dissertations reflect the scholarly communication process. Scientometrics and citation characteristics of dissertations like the subject fields of dissertations, the number of citations and their distribution by type of source, years, and by number of authors etc., have been studied with a view to identify the basic features of the scholarly communication process in different fields of study. The purpose of the present study is to determine the bibliometric characteristics of the biochemistry research in the university of Kerala, India including subject distribution, bibliographic forms of cited documents, most cited journals, collaboration in authorship, etc. A total of 168 doctoral dissertations awarded between 1966 and 2007 at the Department of Biochemistry of University of Kerala were used as a source.

Development of an Electrochemical Insulin Sensor Based on a High Affinity DNA Sequence Found in the Insulin-linked Polymorphic Region

The detection of pertinent biomarkers has the potential provide an early indication of disease progression before considerable damage has been incurred. A decrease in an individual’s sensitivity to insulin, which may be quantified as the ratio of insulin to glucose in the blood after a glucose pulse, has recently been reported as an early predictor of insulin-dependent diabetes mellitus. Routine measurement of insulin levels is therefore desirable in the care of diabetes-prone individuals. A rapid, simple, and reagentless method for insulin detection would allow for wide-spread screenings that provide earlier signs of diabetes onset. The aim of this thesis is to develop a folding-base electrochemical sensor for the detection of insulin. The sensor described herein consists of a DNA probe immobilized on a gold disc electrode via an alkanethiol linker and embedded in an alkanethiol self-assembled monolayer. The probe is labeled with a redox reporter, which readily transfers electrons to the gold electrode in the absence of insulin. In the presence of insulin, electron transfer is inhibited, presumably due to a binding-induced conformational or dynamic change in the DNA probe that significantly alters the electron-tunneling pathway. A 28-base segment of the insulin-linked polymorphic region that has been reported to bind insulin with high affinity serves as the capture element of the DNA probe. Three probe constructs that vary in their secondary structure and position of the redox label are evaluated for their utility as insulin-sensing elements on the electrochemical platform. The effects of probe modification on secondary structure are also evaluated using circular dichroism spectroscopy.

Characterization of Glycation Sites on Human Serum Albumin using Mass Spectrometry

The modification of proteins by reducing sugars is a process that occurs naturally in the body. This process, which is known as glycation, has been linked to many of the chronic complications encountered during diabetes. Glycation has also been linked to changes in the binding of human serum albumin (HSA) to several drugs and small solutes in the body. While these effects are known, there is little information that explains why these changes in binding occur. The goal of this project was to obtain qualitative and quantitative information about glycation that occurs on HSA. The first section of this dissertation examined methods that could be used to quantify and identify glycation that occurs on HSA. The extent of glycation that occurred on HSA was quantified using oxygen-18 labeling mass spectrometry and the glycation sites were identified by observing the mass-to-charge (m/z) shifts that occurred in glycated HSA. This initial investigation revealed that oxygen-18 labeling based quantitation can be improved over previous methods if a relative comparison is done with oxygen-18 labeled peptides in a control HSA sample. Similarly, the process of making m/z shift-based assignments could be improved if only the peptides that were unique to the glycated HSA samples were used with internal calibration. These techniques were used in subsequent chapters for the assignment of early and late-stage glycation products on HSA. The regions of HSA that contained the highest amount of modification were identified, quantified, and ranked in order of their relative abundance. Of the commonly reported glycation sites, the N-terminus was found to have the highest extent of modification, followed by lysines 525, 199, and 439. The relative amount of modification on lysine 281, with respect to the aforementioned residues, varied with different degrees of glycation. The oxygen-18 labeling approach used for this analysis was novel because it allowed for the simultaneous quantification of all glycation-related modifications that were occurring on HSA. As such, several arginine residues were also found to have high amounts of modification on glycated HSA.

THE FLUTE MUSIC OF PAUL DESENNE: A COMPARATIVE ANALYTICAL STUDY OF REPRESENTATIVE WORKS

The significance of the works by Venezuelan-born composer Paul Desenne lies in his unique compositional style that incorporates elements of Latin American folk, pop, and traditional music within the framework of the Western European tradition. His works, though easily classified as art music, nevertheless gain much of their emotional and referential meaning through this rich borrowing. This document focuses on three of Desenne’s flute pieces: the Solo Flute Sonata (2001), Gurrufío for flute orchestra (1997), and Guasa Macabra for flute and clarinet (2003). It provides an analysis of the three works, examining formal, structural, motivic, and rhythmic aspects. Scores and interviews with the composer have been employed as primary sources. Bibliographical material closely related to his music and other secondary sources support this analytical approach. This document also provides an introduction and stylistic discussion of Desenne’s other pieces that incorporate the flute. Chapter one consists of an introduction to Desenne’s life and general considerations of his musical style. Each of the following three chapters focuses on one the three aforementioned flute works, including information about the composition and premiere of each piece as well as analysis and an examination of its incorporation of traditional folk elements. The final chapter presents an introduction to and stylistic discussion of the other flute pieces by this composer. This study intends to provide a basic understanding of Desenne’s flute music, including general characteristics of his musical style, paving the way for further investigation of Desenne’s music, and flute music in particular.