The Host Galaxies of Ultra Hard X-ray Selected AGN

One of the great mysteries surrounding active galactic nuclei (AGN) is their triggering mechanism. Since the discovery that almost all massive galaxies host nuclear supermassive black holes, it has become clear that a trigger mechanism is required to 'turn on' and continue to fuel the central black hole. While it is established that accretion processes are responsible for the energy emitted, the source of the accreting material is still controversial. Furthermore, the energy input from phases of black hole growth is thought to be a key regulator in the formation of galaxies and the establishment of various scaling relations. Theorists often invoke galaxy mergers as the violent mechanism to drive gas into the central regions and ignite luminous quasars, but among more common moderate luminosity AGN, there has been great controversy whether secular processes or mergers dominate AGN fueling. A survey in the ultra hard X-ray band (14--195 keV) is an important new way to answer the fundamental question of AGN fueling. This method is independent of selection effects such as dust extinction and obscuration that plague surveys at other wavelengths because of the ability of the primary continuum to easily pass through large columns of obscuring gas and dust (24 cm-2). In this PhD, we have assembled the largest sample of ultra hard X-ray selected AGN with host galaxy optical data to date, with 185 nearby (z2 keV) imaging

Inflammatory and angiogenic protein detection in the human vitreous : cytometric bead assay

Introduction. To evaluate clinical feasibility and reproducibility of cytometric bead assay (CBA) in nondiluted vitreous samples of patients with age-related macular degeneration (ARMD), diabetic macular edema (DME), and central retinal vein occlusion (CRVO). Methods. Twelve patients from a single clinics day qualified for intravitreal injections (ARMD n = 6, DME n = 3, CRVO n = 3) and underwent a combination treatment including a single-site 23 gauge core vitrectomy which yielded a volume of 0.6 mL undiluted vitreous per patient. Interleukin-6 (IL-6), vascular endothelial growth factor isoform A (VEGF-A), and monocyte chemo-attractant protein-1 (MCP-1) were assessed directly from 0.3 mL at the same day (fresh samples). To assess the reproducibility 0.3 ml were frozen for 60 days at -80°, on which the CBA was repeated (frozen samples). Results. In the fresh samples IL-6 was highest in CRVO (median IL-6 55.8 pg/mL) > DME (50.6) > ARMD (3.1). Highest VEGF was measured in CRVO (447.4) > DME (3.9) > ARMD (2.0). MCP-1 was highest in CRVO (595.7) > AMD (530.8) > DME (178). The CBA reproducibility after frozen storage was examined to be most accurate for MCP1 (P = 0.91) > VEGF (P = 0.68) > IL-6 (P = 0.49). Conclusions. CBA is an innovative, fast determining, and reliable technology to analyze proteins in fluids, like the undiluted vitreous, which is important to better understand ocular pathophysiology and pharmacology. There is no influence of intermittent storage at -80° for the reproducibility of the CBA

Semantic and Mathematical Foundations for Intuitionism

Thesis (Ph.D.) - Indiana University, Philosophy, 2013My dissertation concerns the proper foundation for the intuitionistic mathematics whose development began with L.E.J. Brouwer's work in the first half of the 20th Century. It is taken for granted by most philosophers, logicians, and mathematicians interested in foundational questions that intuitionistic mathematics presupposes a special, proof-conditional theory of meaning for mathematical statements. I challenge this commonplace. Classical mathematics is very successful as a coherent body of theories and a tool for practical application. Given this success, a view like Dummett's that attributes a systematic unintelligibility to the statements of classical mathematicians fails to save the relevant phenomena. Furthermore, Dummett's program assumes that his proposed semantics for mathematical language validates all and only the logical truths of intuitionistic logic. In fact, it validates some intuitionistically invalid principles, and given the lack of intuitionistic completeness proofs, there is little reason to think that every intuitionistic logical truth is valid according to his semantics. In light of the failure of Dummett's foundation for intuitionism, I propose and carry out a reexamination of Brouwer's own writings. Brouwer is frequently interpreted as a proto-Dummettian about his own mathematics. This is due to excessive emphasis on some of his more polemical writings and idiosyncratic philosophical views at the expense of his distinctively mathematical work. These polemical writings do not concern mathematical language, and their principal targets are Russell and Hilbert's foundational programs, not the semantic principle of bivalence. The failures of these foundational programs has diminished the importance of Brouwer's philosophical writings, but his work on reconstructing mathematics itself from intuitionistic principles continues to be worth studying. When one studies this work relieved of its philosophical burden, it becomes clear that an intuitionistic mathematician can make sense of her mathematical work and activity without relying on special philosophical or linguistic doctrines. Core intuitionistic results, especially the invalidity of the logical principle tertium non datur, can be demonstrated from basic mathematical principles; these principles, in turn, can be defended in ways akin to the basic axioms of other mathematical theories. I discuss three such principles: Brouwer's Continuity Principle, the Principle of Uniformity, and Constructive Church's Thesis

Analysis of Blood Flow in the Long Posterior Ciliary Artery of the Cat

PURPOSE. Experiments were undertaken to use a new technique for direct on-line measurement of blood flow in the long posterior ciliary artery (LPCA) in cats and to evaluate possible physiological mechanisms controlling blood flow in the vascular beds perfused by this artery. METHODS. Blood flow in the temporal LPCA was measured on a continuous basis using ultrasonic flowmetry in anesthetized cats. Effects of acute sectioning of the sympathetic nerve and changes in LPCA and cerebral blood flows in response to altered levels of inspired CO 2 and O 2 were tested in some animals. In others, the presence of vascular autoregulatory mechanisms in response to stepwise elevations of intraocular pressure was studied. RESULTS. Blood flow in the temporal LPCA averaged 0.58 ± 0.03 ml/min in 45 cats anesthetized with pentobarbital. Basal LPCA blood flow was not altered by acute sectioning of the sympathetic nerve or by changes in low levels of inspired CO 2 and O 2 , although 10% CO 2 caused a modest increase. Step wise elevations of intraocular pressure resulted in comparable stepwise decreases of LPCA blood flow, with perfusion pressure declining in a linear manner throughout the perfusion-pressure range. CONCLUSIONS. Ultrasonic flowmetry seems to be a useful tool for continuous on-line measurement of LPCA blood flow in the cat eye. Blood flow to vascular beds perfused by this artery does not seem to be under sympathetic neural control and is refractory to modest alterations of blood gas levels of CO 2 and O 2 . Blood vessels perfused by the LPCA show no clear autoregulatory mechanisms. (Invest Ophthalmol Vis Sci. 1999;40:800-804) M any techniques have been used for measurement of uveal blood flow, including direct cannulation of venous outflow channels, measurement of temperature changes in specific ocular regions, and determination of changes of oxygen tension by placement of oxygen-sensitive electrodes in the eye. 1 ' 2 Quantitative blood flow determinations have been accomplished using tissue clearance of inert gases. 3 Drawbacks of these techniques include the need to enter the globe for regional measurements and the limited number of data points that can be determined in a given time. In the most common noninvasive method for ocular blood flow determinations, radioactively labeled microspheres are injected and become trapped in proportion to blood flow in the capillary beds. In this study, an attempt was made to measure LPCA blood flow directly in a continuous manner in the cat eye in vivo, by using ultrasonic flowmetry and miniature flow probes specifically designed for flow measurements in very small-diameter arteries. Cats were chosen because the anatomy and perfusion region of the two LPCAs in this species are more similar to those of humans than are those of other nonprimate experimental animals. Experiments were performed to determine the underlying physiological mechanisms controlling flow in the blood vessels supplied by this artery, including the role of sympathetic innervation, responsiveness to alterations of blood gases, and presence of autoregulatory mechanisms in response to stepwise decreases of perfusion pressure. MATERIALS AND METHODS General Adult cats of either sex were anesthetized with 36 mg/kg pentobarbital injected intraperitoneally. The trachea was intubated for positive-pressure artificial ventilation. A femoral artery and vein were cannulated with a pressure transducer for measurement of systemic arterial blood pressure (model P23; Statham, Hato Roy, Puerto Rico) and for intravenous drug administration, respectively. The animals were positioned in a stereotaxic device (David Kopf, Tujunga, CA) to immobilize the head and were placed on positive artificial ventilation with room air using a respirator (Harvard Apparatus, South Natick, MA). Neuromuscular relaxation was achieved with 4 mg/kg intravenous gallamine triethiodide. End-expiratory CO 2 levels were maintained between 35% and 4% by a capnometer (model 2200; Traverse Medical Monitors, San Luis Obispo, CA) by adjustments of rate and depth of respiration. Determinations of arterial pH and blood gas levels were measured (model 1304; Instrumentation Laboratory, Lexington, MA). Heart rate was derived from the femoral arterial pulse wave. Rectal temperature was maintained at approximately 37°C with a heating pad and infrared lamp. All physiological responses were recorded on a polygraph (model 7; Grass, Quincy, MA). The animals were treated in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. Blood Flow Measurements Blood flow in the temporal LPCA was measured by ultrasonic flowmetry using a transit time ultrasonic flowmeter (model T106; Transonic, Ithaca, NY) coupled with a 0.5-mm miniature flow probe (7.2 mHz). With this technique, after extensive surgery on the lateral orbit, the vessel is exposed and placed within the window of the probe, which houses two ultrasonic transducers and a fixed acoustic reflector. Electrical excitation causes the transducer to emit ultrasound waves, which interDownloaded from iovs.arvojournals.org on 07/01/201