Commencement Address

Commencement address given by The Honorable J. C. Watts, U. S. Representative from Oklahoma, to the Spring 2000 graduating class of The Ohio State University, Oval, Columbus, Ohio, June 9, 2000

Lunar lander conceptual design

A conceptual design is presented of a Lunar Lander, which can be the primary vehicle to transport the equipment necessary to establish a surface lunar base, the crew that will man the base, and the raw materials which the Lunar Station will process. A Lunar Lander will be needed to operate in the regime between the lunar surface and low lunar orbit (LLO), up to 200 km. This lander is intended for the establishment and operation of a manned surface base on the moon and for the support of the Lunar Space Station. The lander will be able to fulfill the requirements of 3 basic missions: A mission dedicated to delivering maximum payload for setting up the initial lunar base; Multiple missions between LLO and lunar surface dedicated to crew rotation; and Multiple missions dedicated to cargo shipments within the regime of lunar surface and LLO. A complete set of structural specifications is given

Associated production of Z and neutral Higgs bosons at the CERN Large Hadron Collider

We study the hadroproduction of a CP-even or CP-odd neutral Higgs boson in association with a Z boson in the minimal supersymmetric extension of the standard model (MSSM) We include the contributions from quark-antiquark annihilation at the tree level and those from gluon-gluon fusion, which proceeds via quark and squark loops, and list compact analytic results. We quantitatively analyze the hadronic cross sections at the CERN Large Hadron Collider assuming a favorable supergravity-inspired MSSM scenario.Comment: 24 pages, 8 figures. arXiv admin note: substantial text overlap with arXiv:hep-ph/010301

Aspects of comparative growth, morphology and anatomy of long and short shoots of Betula papyrifera Marsh

The primary objectives of this research were: 1) To compare long and short shoot growth utilizing growth analysis techniques. 2) To describe the general morphology of long and short shoots and to compare them using morphometric analysis. 3) To compare vegetative and reproductive shoot growth and to assess the cost of reproduction. 4) To study the inception and apical organization of potential long and short shoot buds at selected stages of development and ascertain any differences. 5) To compare the anatomy of long and short shoots, with emphasis on stem anatomy. 6) To correlate these data in order to develop an understanding of how long and short shoot growth in paper birch relates to other studies of long and short shoots. The results/observations and discussion, with appropriate introductory paragraphs pertaining to specific portions of this study are presented as separate chapters. A general summary chapter will collate and discuss the pertinent findings. This format is adopted to enhance convenience of presentation and readability since some of the chapters have been submitted for publication

The effects of peripheral and central high insulin on brain insulin signaling and amyloid-β in young and old APP/PS1 mice

Hyperinsulinemia is a risk factor for late-onset Alzheimer's disease (AD). In vitro experiments describe potential connections between insulin, insulin signaling, and amyloid-β (Aβ), but in vivo experiments are needed to validate these relationships under physiological conditions. First, we performed hyperinsulinemic-euglycemic clamps with concurrent hippocampal microdialysis in young, awake, behaving APP(swe)/PS1(dE9) transgenic mice. Both a postprandial and supraphysiological insulin clamp significantly increased interstitial fluid (ISF) and plasma Aβ compared with controls. We could detect no increase in brain, ISF, or CSF insulin or brain insulin signaling in response to peripheral hyperinsulinemia, despite detecting increased signaling in the muscle. Next, we delivered insulin directly into the hippocampus of young APP/PS1 mice via reverse microdialysis. Brain tissue insulin and insulin signaling was dose-dependently increased, but ISF Aβ was unchanged by central insulin administration. Finally, to determine whether peripheral and central high insulin has differential effects in the presence of significant amyloid pathology, we repeated these experiments in older APP/PS1 mice with significant amyloid plaque burden. Postprandial insulin clamps increased ISF and plasma Aβ, whereas direct delivery of insulin to the hippocampus significantly increased tissue insulin and insulin signaling, with no effect on Aβ in old mice. These results suggest that the brain is still responsive to insulin in the presence of amyloid pathology but increased insulin signaling does not acutely modulate Aβ in vivo before or after the onset of amyloid pathology. Peripheral hyperinsulinemia modestly increases ISF and plasma Aβ in young and old mice, independent of neuronal insulin signaling. SIGNIFICANCE STATEMENT The transportation of insulin from blood to brain is a saturable process relevant to understanding the link between hyperinsulinemia and AD. In vitro experiments have found direct connections between high insulin and extracellular Aβ, but these mechanisms presume that peripheral high insulin elevates brain insulin significantly. We found that physiological hyperinsulinemia in awake, behaving mice does not increase CNS insulin to an appreciable level yet modestly increases extracellular Aβ. We also found that the brain of aged APP/PS1 mice was not insulin resistant, contrary to the current state of the literature. These results further elucidate the relationship between insulin, the brain, and AD and its conflicting roles as both a risk factor and potential treatment

Selective Optical Charge Generation, Storage and Readout in a Single Self Assembled Quantum Dot

We report the investigation of a single quantum dot charge storage device. The device allows selective optical charging of a single dot with electrons, storage of these charges over timescales much longer than microseconds and reliable optical readout of the charge occupancy using a time gated photoluminescence technique. This device enables us to directly investigate the electric field dependent tunneling escape dynamics of electrons at high electric fields over timescales up to 4 us. The results demonstrate that such structures and measurement techniques can be used to investigate charge and spin dynamics in single quantum dots over microsecond timescales.Comment: Accepted for publication in AP