Manipulating and Understanding the Cultured Neuronal Network through Conducting Polymers

Conducting polymers are class of polymer that can be synthesized directly on conductive substrates and incorporate various functional molecules into it. Its conductivity and customizability make it an ideal interface material for neuronal network research. In the first phase of this thesis, the incorporation of laminin fragments into conducting polymer films is investigated. The laminin fragments are shown to produce low impedance surfaces for neuronal recording. Furthermore, it is shown that the incorporated laminin fragments promote the adhesion of neurons to the surface. These results could provide a means for promoting a stable interface for chronic recording devices.In the second phase of this thesis, In vitro multielectrode arrays provide a framework for studying polypyrrole-mediated controlled release of neurochemicals from microelectrodes, and neuronal network dynamics in a controlled setting. We have developed a technique to achieve transient and local inhibition of synaptic transmission in cultured networks. Conducting polymer films containing the glutamate receptor antagonist CNQX are synthesized directly on the microelectrodes in the recording array. Release of CNQX is achieved through a brief electrical pulse. Through single cell patch-clamp recording, the effectiveness of CNQX release on inhibiting excitatory post-synaptic currents (EPSC) is characterized as a function of distance and time from the releasing electrode, and evidence is shown supporting a diffusion-mediated process following release. At the network level, simultaneous patch-clamp and extracellular recordings are used to characterize stimulus-evoked responses from the network. Cross correlation and a model-based variable clustering technique identify functional connectivity in a neuronal network response to electrical stimuli. Use of the controlled release of CNQX in conjunction with these techniques will allow us to examine the functional clustering of neurons in response to a given stimulation, and how a functional cluster is affected by transient, local inhibition in the network

South Boston redevelopment

Thesis (M.Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1958.by Richard C. Stauffer.M.Arch

Implementing Manufacturing Resources Planning for Marine Corps Logistics Base

http://archive.org/details/implementingmanu00stauN

Planetary surface exploration: MESUR/autonomous lunar rover

Planetary surface exploration micro-rovers for collecting data about the Moon and Mars was designed by the Department of Mechanical Engineering at the University of Idaho. The goal of both projects was to design a rover concept that best satisfied the project objectives for NASA-Ames. A second goal was to facilitate student learning about the process of design. The first micro-rover is a deployment mechanism for the Mars Environmental SURvey (MESUR) Alpha Particle/Proton/X-ray instruments (APX). The system is to be launched with the sixteen MESUR landers around the turn of the century. A Tubular Deployment System and a spiked-legged walker was developed to deploy the APX from the lander to the Martian surface. While on Mars the walker is designed to take the APX to rocks to obtain elemental composition data of the surface. The second micro-rover is an autonomous, roving vehicle to transport a sensor package over the surface of the moon. The vehicle must negotiate the lunar-terrain for a minimum of one year by surviving impacts and withstanding the environmental extremes. The rover is a reliable track-driven unit that operates regardless of orientation which NASA can use for future lunar exploratory missions. A detailed description of the designs, methods, and procedures which the University of Idaho design teams followed to arrive at the final designs are included

Mutational Analysis of the Arf1•GTP/Arf GAP Interface Reveals an Arf1 Mutant that Selectively Affects the Arf GAP ASAP1

SummaryArf1 is a GTP binding protein that functions at a number of cellular sites to control membrane traffic and actin remodeling. Arf1 is regulated by site-specific GTPase-activating proteins (GAPs). The combined results of crystallographic and biochemical studies [1–3] have led to the proposal that Arf1 GAPs differ in the specific interface formed with Arf1. To test this hypothesis, we have used mutagenesis to examine the interaction of three Arf GAPs (ASAP1, AGAP1, and ArfGAP1) with switch 1, switch 2, and α helix3 of Arf1. The GAPs were similar in being affected by mutations in switch 1 and 2. However, effects of a mutation within α helix3 and specific mutations within switch 1 and 2 differed among the GAPs. The largest differences were observed with a change of isoleucine 46 to aspartate ([I46D]Arf1), which reduced ASAP1-induced catalysis by ∼10,000-fold but had a 3-fold effect on AGAP1. The reduction was due to an isolated effect on the catalytic rate, kcat. In vivo [I46D]Arf1 had no detectable effect on the Golgi apparatus but, instead, functioned as a constitutively active mutant in the cell periphery, affecting the localization of ASAP1 and paxillin. Based on our results, we conclude that the contribution of specific residues within switch 1 of Arf to binding and achieving a transition state toward GTP hydrolysis differs among Arf GAPs

The very large G-protein coupled receptor VLGR1: a component of the ankle link complex required for the normal development of auditory hair bundles

Sensory hair bundles in the inner ear are composed of stereocilia that can be interconnected by a variety of different link types, including tip links, horizontal top connectors, shaft connectors, and ankle links. The ankle link antigen is an epitope specifically associated with ankle links and the calycal processes of photoreceptors in chicks. Mass spectrometry and immunoblotting were used to identify this antigen as the avian ortholog of the very large G-protein-coupled receptor VLGR1, the product of the Usher syndrome USH2C (Mass1) locus. Like ankle links, Vlgr1 is expressed transiently around the base of developing hair bundles in mice. Ankle links fail to form in the cochleae of mice carrying a targeted mutation in Vlgr1 (Vlgr1/del7TM), and the bundles become disorganized just after birth. FM1-43 [N-(3-triethylammonium)propyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] dye loading and whole-cell recordings indicate mechanotransduction is impaired in cochlear, but not vestibular, hair cells of early postnatal Vlgr1/del7TM mutant mice. Auditory brainstem recordings and distortion product measurements indicate that these mice are severely deaf by the third week of life. Hair cells from the basal half of the cochlea are lost in 2-month-old Vlgr1/del7TM mice, and retinal function is mildly abnormal in aged mutants. Our results indicate that Vlgr1 is required for formation of the ankle link complex and the normal development of cochlear hair bundles

The Potential Geographical Distribution of Bactrocera cucurbitae (Diptera: Tephritidae) in China Based on Eclosion Rate Model and ArcGIS

Abstract. The melon fruit fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), is one of the important insect pests of fruits and vegetables. In order to monitor and control it effectively, it is necessary to know the potential geographical distribution of this pest. The ER (Eclosion rate) model was constructed from empirical biological data, and analyzed with ArcGIS. Based on the soil temperature and moisture data of Chinese meteorological stations, the potential geographical distribution of B. cucurbitae from January to December in China was predicted. Six categories were used to describe different levels of suitability for B. cucurbitae in China. The potential geographical distribution and suitable levels for every month in China were obtained and showed that almost all locations were suitable from May to September. Further analysis showed that monitoring measures should be taken in Guangdong, Guangxi, Yunnan, and Hainan provinces throughout the year

Planetary surface exploration MESUR/autonomous lunar rover

Planetary surface exploration micro-rovers for collecting data about the Moon and Mars have been designed by the Department of Mechanical Engineering at the University of Idaho. The goal of both projects was to design a rover concept that best satisfied the project objectives for NASA/Ames. A second goal was to facilitate student learning about the process of design. The first micro-rover is a deployment mechanism for the Mars Environmental Survey (MESUR) Alpha Particle/Proton/X-ray (APX) Instrument. The system is to be launched with the 16 MESUR landers around the turn of the century. A Tubular Deployment System and a spiked-legged walker have been developed to deploy the APX from the lander to the Martian Surface. While on Mars, the walker is designed to take the APX to rocks to obtain elemental composition data of the surface. The second micro-rover is an autonomous, roving vehicle to transport a sensor package over the surface of the moon. The vehicle must negotiate the lunar terrain for a minimum of one year by surviving impacts and withstanding the environmental extremes. The rover is a reliable track-driven unit that operates regardless of orientation that NASA can use for future lunar exploratory missions. This report includes a detailed description of the designs and the methods and procedures which the University of Idaho design teams followed to arrive at the final designs