An Eighteenth-Century French Snuffbox as an Object of Social Status

Includes bibliographical reference

Missouri, Heart of the Nation Art, Commerce, and Civic Pride

"In the painting Note from St. Louis by Lawrence Beall Smith, a shoeshine boy pauses during his working day to gaze at The Meeting of the Rivers, a recently installed fountain. Connecting St. Louis with ancient Greek and Roman cultures, Carl Milles's fountain greets visitors to St. Louis as they arrive at and depart from Union Station. The fountain symbolizes the confluence of two mighty rivers, the Mississippi and the Missouri, and heralds the importance of these rivers for the mythos of Missouri. The shoeshine boy has parked his kit at his side on the pavement and stands contemplating a sculpture of a putto struggling with a gargantuan fish. Jets of water arch over and around this tableau. The shoeshine boy embodies what some felt art could do -- elevate the morals and sensibilities of the working and middle class with a promise of personal transformation."--First paragraph.Includes bibliographical reference

Big ideas in little boxes : nation building in three nineteenth-century American parlor games by Milton Bradley and Company

Milton Bradley and Company manufactured its first game, The Checkered Game of Life, in 1860, only months before the American Civil War broke out. Soon after, it produced the Myriopticon A Historical Panorama of the Rebellion, and the Historiscope A Panorama and History of America. Producing "moral, instructive and entertaining home amusements" proved to be good business for the company. This dissertation investigates the behaviors, beliefs, assumptions and worldview of midnineteenth-century American society just before and after the American Civil War through the examination of three parlor amusements. Grounding my analysis in the religious, social, visual and material culture of the time, I ask the question: Why would buying and playing these games appeal to families right after the conclusion of the Civil War, at a time when the nation and families struggled to reconstruct themselves? My findings suggest playing these three parlor amusements accomplished at least three ends: reaffirmed the woman's role in the moral education of children and families, confirmed the desire for a united nation, and side stepped any engagement with change in the social and political ideology of that newly united nation. My analysis reveals that the three parlor games I studied acted as guardians of the ideals already established and enshrined in the American origin story told since the late 1700s and retold in the Historiscope.Includes bibliographical reference

Pharmacokinetic modeling of cortisol binding to dietary fiber in the gastrointestinal tract

Abstract only availableCortisol is a glucocorticoid hormone produced in the adrenal cortex during stressful situations. The purpose of this project was to determine whether cortisol binds to dietary fiber and to design a pharmacokinetic model to predict whether or not fiber has a significant binding capacity in the human gastrointestinal tract. Studies have shown that estrogen binds to dietary fiber. Coumesterol, a cholesterol derived steroid structurally similar to estrogen, is also thought to bind to dietary fiber. The fluorescence of coumestrol bound to oat, wheat and psyllium fiber was analyzed in order to determine the binding capacities of each. This indicates that steroids have different binding capacities important in the pharmacokinetic model. This model would provide useful information capable of predicting physiological changes due to changes in dietary habits as well as medicines such as antibiotics that may alter steroid secretion. If steroids do have a recycling route and dietary fiber has a significant binding capacity in the human body then an increase in dietary fiber may result in a decrease in cortisol.NSF-REU Program in Biosystems Modeling and Analysi

Extracellular Protons Regulate the Extracellular Cation Selectivity of the Sodium Pump

The effects of 0.3–10 nM extracellular protons (pH 9.5–8.0) on ouabain-sensitive rubidium influx were determined in 4,4′-diisocyanostilbene-2, 2′-disulfonate (DIDS)-treated human and rat erythrocytes. This treatment clamps the intracellular H. We found that rubidium binds much better to the protonated pump than the unprotonated pump; 13-fold better in rat and 34-fold better in human erythrocytes. This clearly shows that protons are not competing with rubidium in this proton concentration range. Bretylium and tetrapropylammonium also bind much better to the protonated pump than the unprotonated pump in human erythrocytes and in this sense they are potassium-like ions. In contrast, guanidinium and sodium bind about equally well to protonated and unprotonated pump in human red cells. In rat red cells, protons actually make sodium bind less well (about sevenfold). Thus, protons have substantially different effects on the binding of rubidium and sodium. The effect of protons on ouabain binding in rat red cells was intermediate between the effects of protons on rubidium binding and on sodium binding. Remarkably, all four cationic inhibitors (bretylium, guanidinium, sodium, and tetrapropylammonium) had similar apparent inhibitory constants for the unprotonated pump (∼5–10 mM). The Kd for proton binding to the human pump, with the empty transport site facing extracellularly is 13 nM, whereas the extracellular transport site loaded with sodium is 9.5 nM, and with rubidium is 0.38 nM. In rat red cells there is also a substantial difference in the Kd for proton binding to the sodium-loaded pump (14.5 nM) and the rubidium-loaded pump (0.158 nM). These data suggest that important rearrangements occur at the extracellular pump surface as the pump moves between conformations in which the outward facing transport site has sodium bound, is empty, or has rubidium bound and that guanidinium is sodium-like and bretylium and tetrapropylammonium are rubidium-like

Encapsulation of FITC to monitor extracellular pH: a step towards the development of red blood cells as circulating blood analyte biosensors

A need exists for a long-term, minimally-invasive system to monitor blood analytes. For certain analytes, such as glucose in the case of diabetics, a continuous system would help reduce complications. Current methods suffer significant drawbacks, such as low patient compliance for the finger stick test or short lifetime (i.e., 3–7 days) and required calibrations for continuous glucose monitors. Red blood cells (RBCs) are potential biocompatible carriers of sensing assays for long-term monitoring. We demonstrate that RBCs can be loaded with an analyte-sensitive fluorescent dye. In the current study, FITC, a pH-sensitive fluorescent dye, is encapsulated within resealed red cell ghosts. Intracellular FITC reports on extracellular pH: fluorescence intensity increases as extracellular pH increases because the RBC rapidly equilibrates to the pH of the external environment through the chloride-bicarbonate exchanger. The resealed ghost sensors exhibit an excellent ability to reversibly track pH over the physiological pH range with a resolution down to 0.014 pH unit. Dye loading efficiency varies from 30% to 80%. Although complete loading is ideal, it is not necessary, as the fluorescence signal is an integration of all resealed ghosts within the excitation volume. The resealed ghosts could serve as a long-term (>1 to 2 months), continuous, circulating biosensor for the management of diseases, such as diabetes

Development of an assay to measure cortisol using a standard glucose meter

Abstract only availableWhen an animal is stressed many changes occur, such as altered behavior and reduced resistance to disease, and these effect population performance (Millspaugh 2004). Cortisol is a stress hormone produced by the adrenal glands to regulate cardiovascular function, and energy utilization. Clinicians and wildlife biologists monitor cortisol levels in animals to determine their stress levels . Current tests must be done in a research lab; I want to develop a test that can be used at home or in the field. Four methods were compared: a glucose meter, FOX (ferric-xylenol orange complex) assay, o-dianisidine assay, and a lanthanide-based luminescent sensing probe, all of which detect H2O2, which is produced by glucose oxidase. The glucose oxidase will be used as a label for cortisol in an immunoassay. I assessed the sensitivity of the four methods. O-dianisidine assay detected 2.5 µM H2O2, lanthanide detected 5 µM H2O2, FOX detected 25µM H2O2, the glucose meter detected 500µM H2O2. I have found that the OneTouch Sure Step® glucose meter detects H2O2 in the absence of glucose. The optimal method for field/home testing has to have great sensitivity and also be easy to quantitate. Even though the meter had the lowest sensitivity, it is the most convenient and inepensive approach for quantitation. We are using modeling and other approaches to develop the best method(s) for cortisol measurement that will not only aid conservation biology, but it can also be used to monitor patient hormonal levels for treatment of endocrine disorders including Cushing's syndrome.NSF-REU Program in Biosystems Modeling and Analysi

Compartmentalization of Calcium Extrusion Mechanisms in the Outer and Inner Segments of Photoreceptors

AbstractDifferential localization of calcium channel subtypes in divergent regions of individual neurons strongly suggests that calcium signaling and regulation could be compartmentalized. Region-specific expression of calcium extrusion transporters would serve also to partition calcium regulation within single cells. Little is known about selective localization of the calcium extrusion transporters, nor has compartmentalized calcium regulation within single neurons been studied in detail. Sensory neurons provide an experimentally tractable preparation to investigate this functional compartmentalization. We studied calcium regulation in the outer segment (OS) and inner segment/synaptic terminal (IS/ST) regions of rods and cones. We report these areas can function as separate compartments. Moreover, ionic, pharmacological, and immunolocalization results show that a Ca-ATPase, but not the Na+/K+, Ca2+ exchanger found in the OSs, extrudes calcium from the IS/ST region. The compartmentalization of calcium regulation in the photoreceptor outer and inner segments implies that transduction and synaptic signaling can be independently controlled. Similar separation of calcium-dependent functions is likely to apply in many types of neuron

The plasma membrane calcium ATPase (PMCA) of neurones is electroneutral and exchanges 2 H+ for each Ca2+ or Ba2+ ion extruded

The coupling between Ca2+ extrusion and H+ uptake by the ubiquitous plasma membrane calcium ATPase (PMCA) has not been measured in any neurone. I have investigated this with Ca2+- and pH-sensitive microelectrodes in large voltage-clamped snail neurones, which have no Na+–Ca2+ exchangers. The recovery of [Ca2+]i and surface pH after a brief depolarization or Ca2+ injection was not slowed by hyperpolarization to −90 mV from a holding potential of −50 mV, consistent with a 1 Ca2+ : 2 H+ coupling ratio. Since Ca2+ injections proved difficult to quantify, and Ca2+ currents through channels were obscured by K+ currents, Ba2+ was used as a substitute. When the cell was bathed in Ca2+-free Ba2+ Ringer solution, the K+ currents were blocked and large inward currents were revealed on depolarization. The Ca2+-sensitive microelectrodes were sensitive to intracellular Ba2+ as well as Ca2+. With equal depolarizations Ba2+ entry appeared larger than Ca2+ entry and generated similar but slower pH changes. Ba2+ extrusion was insensitive to hyperpolarization, blocked by eosin or high pH, and about 5 times slower than Ca2+ extrusion. The ratio of the pH change caused by the extrusion of unit charge of Ba2+ influx to that caused by unit charge of H+ injection was 0.85 ± 0.08 (s.e.m., n= 8), corresponding to a Ba2+ : H+ ratio of 1 : 1.7. Both this ratio and the electroneutrality of the PMCA suggest that the Ca2+ : H+ ratio is 1 : 2, ensuring that after a Ca2+ influx [Ca2+]i recovery is not influenced by the membrane potential and maximizes the conversion of Ca2+ influxes into possible pH signals