Most Popular Books by Adam Christopher

Abstract: Previous experimental work has shown the efficacy of vortex generator jets as a means for control of external flow, particularly in the case of separated flow and high-angle-of-attack stall for an airfoil. Effective control of the flow separation requires a model for the relevant fluid dynamics that accurately captures the physics involved, including the interaction between the actuators and the system, while simultaneously being simple enough to run in real time.

The catalytic (C) subunit of cAMP-dependent protein kinase (PKA) can be regulated by co- and post-translational modifications. The C-subunit is co-translationally N-myristylated. N-myristylation is catalyzed by the enzyme N-myristyl transferase (NMT), and it is the incorporation of the 14 carbon, saturated fatty acid, myristic acid, onto the N-terminal glycine residue of a target protein. In PKA, N-myristylation enhances the thermal stability of the protein and increases membrane binding in RII but not RI holoenzyme complexes. In these studies, the myristylated C-subunit was crystallized in different states including bound to a substrate peptide alone as well as to a substrate peptide and an ATP analogue. Furthermore, time-resolved fluorescence anisotropy and MD simulations were performed to analyze the effects of N-myristylation on C-subunit dynamics. These studies showed that N-myristylation stabilizes the N-terminus and myristate pocket of PKA and exhibits effects on dynamics throughout the enzyme including at the active site. Myristylation may, therefore, provide allosteric regulation of PKA. The reaction mechanism of PKA is also well-characterized. ADP-release is the rate-limiting step in PKA reaction turnover, and ADP-release is governed by magnesium concentration. PKA binds two magnesium ions termed Mg1 and Mg2 with the numbering based on the order in which the ions were thought to bind. However, recent studies suggest that the magnesium ions may bind in reverse order, and the mode of magnesium and ADP-release following phosphoryl transfer is unresolved. In these studies, the C-subunit was crystallized displaying partial and complete phosphoryl transfer of AMP-PNP onto a substrate peptide. These structures showed that Mg1 is released following complete phosphoryl transfer, and therefore, Mg1 release may be an important step preceding ADP release. Also, the C-subunit of PKA was crystallized in an apo state and bound to ADP. The ADP bound structure showed that ADP binds to the C-subunit with one magnesium ion, and this ion corresponds to Mg2 verifying the results from the partial and complete phosphoryl transfer structures. Furthermore, the ADP bound structure adopts a novel conformation that may represent the possible motions associated with ADP release including opening of the Gly-rich loop and C-tail away from the active site.

The IV-VI semiconductors, and specifically the lead-salts (PbS, PbSe, and PbTe), are a natural choice for nanocrystal science. In nanocrystals, because of their narrow band gap, small effective masses, and large dielectric constants, they offer a unique combination of both strong confinement and strong dielectric contrast with their environment. Studying how these two effects modify optical and electrical properties of nanocrystals will be the topic of this dissertation. We begin with a summary of the synthesis of high-quality PbS and PbSe nanocrystals. Special care is taken to explain the chemical procedures in detail to an audience not expected to have significant prior chemistry knowledge. The synthesized nanocrystals have bright and tunable emission that spans the edge of the visible to the near-IR spectrum (700-1800 nm), and they are capped with organic ligands making them easily adaptable to different substrates or hosts . This combination of high optical quality and flexible device engineering make them extremely desirable for application. Moving beyond single-material nanocrystals, we next explore nanocrystal heterostructures, specifically materials with a spherical core of one semiconductor and a shell of another. Core-shell structures are commonly used in nanocrystals as a method to separate the core material, where the electrons and holes are expected to stay, from interfering effects at the surface. This typically results in improvements in stability and fluorescence quantum efficiency. To that end, we develop a model to explain how confinement plays out across abrupt changes in material, focusing on the optical and electrical properties of recently synthesized PbSe/PbS core-shell quantum dots. We show that for typical sizes of these nanocrystals, a novel type of nanocrystal heterostructure is created, where electrons and holes extend uniformly across the abrupt material boundary, and the shell does not act as a protecting layer. For very large sizes not yet achievable, we expect that the electron and hole will separate in different layers, with potentially measurable effects. Comparisons are made to optical and electrical measurements on these structures, showing good agreement. Next, we explore how shape can impact nanocrystal properties, on top of their intrinsic size or material dependence. By looking at cylindrically shaped nanocrystals, called "nanorods," with aspect ratios 10, we explore how having a slightly extended dimension can impact nanocrystal properties. A model is developed to explain their electronic structure, with surprising results. Foremost is that along the extended dimension, electrons and holes are strongly electrically bound, not with each other directly, but with their image charges in the outer host dielectric material. Nevertheless, the energy spectra of the excitons remains nearly hostindependent, with the effects of this strong binding instead seen in a redistribution of transition oscillator strength. To test the model, we develop a novel synthesis of high quality PbSe nanorods, and find good agreement with measured absorption spectra. Finally, we present a study on the transfer of charge into and out of a nanocrystal. By modeling the charge transfer process within a modified Marcus Theory, we isolate the relevant parameters that can be used to control the rate of transfer. Primary among these are the values of the quantum dot energy levels, and the electrostatic charging energy of the acceptor. We vary the former by changing the quantum dot size, and the latter by varying the host dielectric constant. To test the model, we chemically bind a small molecular acceptor molecule to the surface of PbS nanocrystals and use transient fluorescence to measure the rate of charge transfer. Both the dependence of the rate on quantum dot size and host dielectric constant show good agreement with the model.

Celebrate the lasting impact of Return of the Jedi with this exciting reimagining of the timeless Star Wars film featuring new perspectives from forty contributors. On May 25, 1983, Star Wars cemented its legacy as the greatest movie franchise of all time with the release of Return of the Jedi. In honor of its fortieth anniversary, forty storytellers re-create an iconic scene from Return of the Jedi through the eyes of a supporting character, from heroes and villains to droids and creatures. From a Certain Point of View features contributions by bestselling authors and trendsetting artists.

Mute swans ( Cygnus olor ), an exotic species of waterfowl, have been found to negatively impact native waterbirds and submerged aquatic vegetation (SAV) communities in the Chesapeake Bay and lower Great Lakes. Mute swans were first recorded in Illinois in 1971 and their population is small, but growing. In 2008-09, I studied mute swans in central Illinois to investigate whether they negatively impacted waterbirds through aggressive actions and SAV through over-grazing. I also estimated mute swan territory size to estimate potential habitat exclusion and population growth potential. Mute swan territory size averaged 7.0 ha, allowing the current population of approximately 60 breeding pairs to increase to over 125 pairs. I did not find that mute swans reduced above-ground SAV, although I did find that below-ground biomass was reduced where mute swans fed freely. Mute swan aggression was most frequent in early spring and decreasing throughout the breeding season. Most waterbirds were found just as close or closer to mute swans as to control points, although gadwall ( Anas strepera ) were found farther away perhaps suggesting either avoidance or exclusion. As mute swans become more abundant in Illinois, further monitoring is necessary to prevent significant negative impacts to wetlands and waterbirds.

Using this methodology, I examine the Skira, a Classical Athenian festival of midsummer, employing it as a test case for the claims above. This results in a number of innovations over previous scholarship of the Skira. First, using a careful diachronic accounting of sources, I am able to show that the Skira existed in distinct phases and exhibited marked changes in purpose. Examining the oldest sources, it is clear that the Skira was a women-exclusive festival until 350BCE. At that point, Lycurgus, the Athenian politician, added a new procession to the Skira as part of his attempt to return Athens to its former greatness . This new focus, picturing the Skira as a masculine, patriotic festival, became the dominant way to discuss the festival for the following five hundred years. Second, examining sources synchronically, I am able to show that the earlier women's festival was devoted primarily to Athena, not Demeter as is sometimes claimed. As part of that examination it is necessary also to demonstrate the multiplicity of ways in which Athena impacted the lives of Athenian woman and to complicate an essentialist view of divinities. In a synchronic look at the post-Lycurgan sources, I am able to show how Lycurgus employed the mythology of Euripides' "Erechtheus" to create a new Skira, blending the traditional concerns of Athenian women expressed in the earlier Skira (family, the protection of children, fertility) with a new stress on autochthony and the veneration of ancestors.

In practice, it provided courts with a means to enact the mandates from the Visigothic Code and to foster stability. The result was a flexible synthesis of law, liturgy, and sacred space that was in many cases capable of harnessing spiritual and community pressure in legal proceedings.

The purpose of this dissertation was to produce knowledge on the academic performance and recovery success of students enrolled in a Recovery High School. The study site was Hope Academy, located in Indianapolis, IN, and at the time of this publication, one of just five schools in the U.S. accredited by the Association of Recovery Schools. Students enrolled between Fall 2010 and Spring 2017 were evaluated using academic test scores (NWEA-MAP), a measure of recovery success (GAIN-SS), as well as key informant interviews with 13 students and five staff members. It was concluded that recovery school students displayed similar levels of academic growth when compared to a nationallyrepresentative matched Virtual Comparison Group, t-stat = +0.849 (p=0.397). This finding provides evidence that even after experiencing a relapse, recovery school students were capable of achieving similar levels of academic growth as their peers not in recovery from substance use disorders. Interview participants provided more context to the quantitative findings with first-hand accounts of the impact the recovery school had on students.

A Member of the Food Chain?: Quantifying Primary Productivity from Nazi Germany to the International Biological Program, 1929-1989, tells the story of primary productivity, one of the fundamental measurements of the ecological and earth sciences today. Primary productivity is used in biology to refer to the aggregate photosynthetic production of the plant life of a particular region. Thanks to the rule of thermodynamics, most scientists have regarded the ability of plants to produce carbohydrates using carbon dioxide, water, and solar energy as foundational to all life throughout the twentieth century. Yet the history of the theory and methods used to quantify primary productivity is more complex than the straightforward and seemingly apolitical nature of the idea might initially suggest. This dissertation charts the genesis of this quantified measure from laboratory plant physiology, through agricultural science in National Socialist Germany, to postwar Global Ecology in the US.

These declines were accompanied by coordinate reductions in the levels of rbcS and rbcL mRNA, chloroplast rRNA, chloroplast DNA and total protein. We suggest that the prolongation of senescence in the antisense leaves is due to an impact of source strength on leaf developmental programming that occurs at the level of transcript abundance. To better understand the relationship between carbohydrates and development, we characterized carbon partitioning over ontogeny. Partitioning into ionic fractions, such as amino acids, was maintained at a steady state longer than partitioning into carbohydrates, which followed photosynthetic rate patterns. The ratio of hexoses to sucrose increased up to full leaf expansion, then declined again; however changes in invertase and hexokinase activities did not correlate with this pattern, although they paralleled each other.

Natural products from the marine environment constitute one of the richest and most reliable sources of bioactive molecules for drug discovery and biotechnology. Filamentous marine cyanobacteria are among the most prolific natural product producers, and with significant advances in genetics and genomics over the past decade are gaining increasing recognition for unusual or unprecedented biochemistry involved in natural product biosynthesis. However, the further development of several of these cyanobacterial secondary metabolites has not been accomplished because of low yields from field collections, slow growth of these organisms in laboratory cultures, and an absence of any genetic techniques for DNA manipulation. The aim of the research presented in this dissertation is to study the biosynthesis of natural products from the marine filamentous cyanobacterium majuscula to investigate how access to these compounds can be improved and the full potential of cyanobacterial strains can be realized. A variety of experiments are described herein, including : 1) A transcriptional analysis of the neurotoxin jamaicamide gene cluster from Lyngbya majuscula, which employed RT-PCR and reporter gene assays to better understand how cyanobacterial biosynthetic pathways are transcribed; 2) Investigations into jamaicamide regulation, which included a) protein pulldown assays to isolate possible light related regulatory proteins for this pathway and b) the development of a novel mass spectrometry approach to monitor natural product biosynthetic turnover, the effect of environmental parameters on this turnover, and confirm the impact of light on jamaicamide production; 3) Evaluating different methods for transferring DNA into Lyngbya filaments and taking the first steps in heterologously expressing portions of a Lyngbya gene cluster in the actinomycete Streptomyces coelicolor, and 4) Sequencing the genome of Lyngbya majuscula 3L, thereby revealing its natural product potential, a complex gene regulatory network and a surprising inability to fix atmospheric nitrogen. Collectively, these experiments provide new perspective on natural product biosynthesis in Lyngbya strains and direction on how these organisms and their natural products can be harnessed for biomedical and biotechnological applications.

Homoleptic Groups 4 and 5 metal amide compounds have been used as precursors in CVD/ALD processes to make microelectronic metal oxide thin films. These compounds are often very air sensitive. Ancillary ligands such as amidinates have been used to reduce their air sensitivity and to make their handling easier. Reactions of amidinates with dioxygen and water have thus been used to make metal oxide thin films. Studies of these reactions are important in order to make better precursors and purer thin films. This dissertation focuses on the following areas: (a) Syntheses of zirconium and Group 5 amidinate amides; (b) Studies of the reactions of zirconium amidinate amides with dioxygen or water; (c) Probing the pathway in the formation of an archetypical tungsten alkylidyne complex. Zr[MeC(Ni̳Pr)2]2(NMe2)2 [zirconium amidinate amide] has been prepared through three different routes: two salt metathesis reactions and one aminolysis. The aminolysis of M(NR2)n̳ [metal amide] with i̳PrN(H)C(Me)=Ni̳Pr [diisopropylamidine] gives cleaner products in better yields and this route has been chosen to make amidinates in this dissertation. Reactions of zirconium amidinate amide complexes with dioxygen, water or hydrogen peroxide have been studied. Metal-containing products were {(μ-O)Zr[MeC(Ni̳Pr)2]2}2 [zirconium amidinate oxo dimer] and {(μ-O)Zr[MeC(Ni̳Pr)2]2}n̳ [zirconium amidinate oxo polymer] based on NMR, IR, MS and elemental analysis. Also, the reaction of Zr[MeC(Ni̳Pr)2]2(NMe2)2 with dioxygen yields {(m-h2:h2-O2)Zr[MeC(Ni̳Pr)2]2}3 [zirconium peroxo amidinate trimer] and its crystal structure is reported. Ta[MeC(Ni̳Pr)2](NMe2)4 [tantalum amidinate amide] and carbon tetrachloride undergo an amide-chloride exchange, giving Ta[MeC(Ni̳Pr)2](NMe2)3Cl [tantalum amidinate amide chloride]. Ta[MeC(Ni̳Pr)2](NMe2)3Cl has also been synthesized through the aminolysis of Ta(NMe2)4Cl [tantalum amide chloride] with a diisopropyl amidine. W(CH2t̳Bu)3(≡Ct̳Bu) [tungsten neopentyl neopentylidyne] has been prepared through the reaction of W(OMe)3Cl3 [tungsten chloride methoxide] and Zn(CH2t̳Bu)2 [dineopentyl zinc]. Also, a side product which has been characterized through NMR spectroscopies to be W(OMe)2Cl(CH2t̳Bu)3 [tungsten neopentyl chloride methoxide].

Objectives: This thesis will explore some innovative solutions to communication difficulties that exist in higher education teaching of introductory programming. Communication between a teacher and student is important, as it is the main opportunity where a student can ask a teacher questions about a particular problem they have, and a teacher can give feedback to direct them towards a solution. It is expected that through utilising technology in laboratory practical classes, communication between teachers and student can be improved. Methods: This thesis primarily explores the possibilities of using student compiler and method invocation data, collected during a practical class and sent directly to a teacher. This data maybe beneficial as a method of allowing teachers to see if a student requires help. This thesis utilises a variety of research methods including questionnaires, observations of classroom interactions and collection of data recorded from student and teachers interactions with the technology. The approaches are used during an investigation into the current approaches of laboratory practical teaching, before progressing onto investigations using the technology developed that accompanies this thesis. Results: The results identified that the majority of the students and teachers who used the technology felt that it improved their ability to communicate within laboratory practical classes. The teachers felt that they could use the data collected by the technology to view activity from the students and see a student?s progress. The teachers could interpret the data collected from the technology and students who needed help could be identified. Conclusions: This thesis has demonstrated that technology has the potential to improve communication in laboratory classes, and enable teachers to support students more effectively. However, the technology developed in this thesis, does not eliminate the requirement for a teacher to interact with a student face-to-face, but rather its role is to act as an indicator of students who may need assistance.

This work is a relative exegesis of the Secret Gospel of Saint Thomas; an elaboration of the spiritual seeker's efforts of transformation towards universal understanding, a potential that awaits every person. The capacity for equilibrium bestowed upon us defines our relation to God; depending heavily upon our ideas of the universal method, and when those ideas are revitalized and protracted through the firmament of greater truth, all notions of God, life, and our human station reach upheaval. Our task is uncovering what remains hidden, yet that which always existed, by overcoming the presumptions of a slumbering humanity who in many ways place their seeds of obstruction within us from the very beginning. It is our preeminent task to unmake ourselves in the eyes of mankind and to rebuild ourselves in the image and semblance of God's desire, as this is the human purpose, the calling that does not cease until it is followed to the end; perhaps this book will help.

Cracked rotors present a significant safety and loss hazard in nearly every application of modern turbomachinery. This thesis focuses on the health monitoring, modeling, and analysis of machines with transverse breathing cracks, which open and close due to the self-weight of the rotor. After considering the modeling of cracked rotors, the thesis investigates an active structural health monitoring approach, focusing on the application of an active magnetic actuator to apply a specially designed external force excitation to the rotating shaft. Extensive experimental data has been collected and analyzed utilizing advanced diagnostic techniques. The presented results demonstrate that the use of a magnetic force actuator to apply external excitation has potential in the diagnostics of cracked rotors. The observed unique crack signatures demonstrate the ability of the method for early diagnosis of transverse rotor cracks.