The 50-horsepower solar-powered irrigation facility located near Gila Bend, Arizona

The 50 horsepower solar powered irrigation facility near Gila Bend, Arizona which includes a Rankine cycle demonstrates the technical feasibility of solar powered pumping. The design of a facility specifically for the irrigation farmer using the technology that has been developed over the last four years is proposed

Signals from the 4th Dimension: Role of Extracellular Matrix Signaling in Synaptic Plasticity Mediating Addiction

Chronic cocaine abuse causes maladaptive neuroadaptations that underlie vulnerability to relapse, even after protracted abstinence. A great deal of work has examined mechanisms of neuroplasticity by which these occur. However, the majority of experimentation has focused on intracellular signaling cascades, while the extracellular compartment has been largely ignored. In the past decade, work has emerged in the learning and memory literature that indicates that extracellular matrix remodeling and signaling is required for adaptive forms of neuroplasticity (e.g. learning and memory), although it has not been thoroughly examined in models of maladaptive neuroplasticity. Throughout this dissertation a drug self-administration, extinction and reinstatement paradigm is used. I first examine the role of the matrix metalloproteinases (MMPs) in the nucleus accumbens core (NAcore) in both the persistent synaptic potentiation that occurs following extinction of cocaine self-administration, and in the rapid, transient potentiation that is required for cue-induced reinstatement. By measuring both the expression and activity of MMPs, this work shows that relapse to multiple classes of drugs of abuse (cocaine, nicotine, and heroin) each are accompanied by an induction of MMP activity. Furthermore, this work goes on to show that inhibiting MMP activity also reverses or blocks synaptic potentiation. A second set of experiments examines nitric oxide (NO) signaling as a mechanism of MMP activation. These experiments used biochemical examination of neuronal nitric oxide synthase (nNOS) activity following extinction and reinstatement of cocaine seeking, and a small molecule inhibitor of nNOS to determine the effects of nNOS activity on MMP activity and relapse behavior. Finally, by using NOS1-Cre transgenic mice this work shows that selectively chemogenetically stimulating a small population of interneurons that express nNOS drives reinstatement of drug seeking. This dissertation concludes that nNOS-expressing interneurons may comprise a ‘master-switch’ by MMPs are activated, synapses are potentiated, and strongly motivated behaviors are initiated

Post-aragonite phases of CaCO3_{3} at lower mantle pressures

The stability, structure and properties of carbonate minerals at lower mantle conditions has significant impact on our understanding of the global carbon cycle and the composition of the interior of the Earth. In recent years, there has been significant interest in the behavior of carbonates at lower mantle conditions, specifically in their carbon hybridization, which has relevance for the storage of carbon within the deep mantle. Using high-pressure synchrotron X-ray diffraction in a diamond anvil cell coupled with direct laser heating of CaCO$_{3}$ using a CO$_{2}$ laser, we identify a crystalline phase of the material above 40 GPa $-$ corresponding to a lower mantle depth of around 1,000 km $-$ which has first been predicted by \textit{ab initio} structure predictions. The observed $sp^{2}$ carbon hybridized species at 40 GPa is monoclinic with $P2_{1}/c$ symmetry and is stable up to 50 GPa, above which it transforms into a structure which cannot be indexed by existing known phases. A combination of \textit{ab initio} random structure search (AIRSS) and quasi-harmonic approximation (QHA) calculations are used to re-explore the relative phase stabilities of the rich phase diagram of CaCO$_{3}$. Nudged elastic band (NEB) calculations are used to investigate the reaction mechanisms between relevant crystal phases of CaCO$_{3}$ and we postulate that the mineral is capable of undergoing $sp^{2}$-$sp^{3}$ hybridization change purely in the $P2_{1}/c$ structure $-$ forgoing the accepted post-aragonite $Pmmn$ structure.Comment: 12 pages, 8 figure

Technique for the Measurement of the In-Situ Development Rate

In the past, a Perkin Elmer Development Rate Monitor (DRM) has been used to measure the development rate of photoresist. However, due to several limitations of the DRM, the development rates measured therein, are not truly representative of the resist processing on a production lire. Subtleties in the development system are not obtained through the DRM and hence an in-situ development rate is required. Using a Site Services Development Spray Monitor (DSM 100) and a post processing algorithm. the in-situ measured development rates were obtained. The interference signals for eight different wavelengths were simultaneously monitored on a pattemed wafer as it spun on the development module of a wafer track. Since the interference signal is generated from a circularly polarized light source, the DSM 100 has demonstrated robustness to the red cloud effect, developer spray, bubbles in the developer, and ambient light.\u27 Two algorithms for the calculation of the in-situ development rate are proposed. After collecting the eight interference curves, these post processing algorithms used the Marquardt Levenberg non-linear regression algorithm and a linear regression approach to find the development rate as a function of development time. Although the standing wave effect was visible in the plots of development rate versus time using both techniques, the first approach generated the better curve. A plot of development rate versus depth was generated via numerical integration of the plot of development rate versus time. Since the only equation used in the post processing algorithm is the interference relationship, this technique is equally well suited for other types of exposure and resist chemistries. Possession of the in-situ development rate could provide further insight into resist development mechanisms, the development of better models, and the extraction of photolithography model parameters that are specific to the production process

Statistical Computations with AstroGrid and the Grid

We outline our first steps towards marrying two new and emerging technologies; the Virtual Observatory (e.g, AstroGrid) and the computational grid. We discuss the construction of VOTechBroker, which is a modular software tool designed to abstract the tasks of submission and management of a large number of computational jobs to a distributed computer system. The broker will also interact with the AstroGrid workflow and MySpace environments. We present our planned usage of the VOTechBroker in computing a huge number of n-point correlation functions from the SDSS, as well as fitting over a million CMBfast models to the WMAP data.Comment: Invited talk to appear in "Proceedings of PHYSTAT05: Statistical Problems in Particle Physics, Astrophysics and Cosmology

Lift-and-Round to Improve Weighted Completion Time on Unrelated Machines

We consider the problem of scheduling jobs on unrelated machines so as to minimize the sum of weighted completion times. Our main result is a $(3/2-c)$-approximation algorithm for some fixed $c>0$, improving upon the long-standing bound of 3/2 (independently due to Skutella, Journal of the ACM, 2001, and Sethuraman & Squillante, SODA, 1999). To do this, we first introduce a new lift-and-project based SDP relaxation for the problem. This is necessary as the previous convex programming relaxations have an integrality gap of $3/2$. Second, we give a new general bipartite-rounding procedure that produces an assignment with certain strong negative correlation properties.Comment: 21 pages, 4 figure

Construction and characterization of a large insert porcine YAC library

The recent construction of genetic linkage maps of the porcine genome (Rohrer et al. 1994, 1996; Ellegren et al. 1994; Archibald et al. 1995) allows the assignment of loci affecting heritable traits of economic importance (ETLs; Lander and Botstein 1989) to specific chromosomal segments. Markers can thus be identified that may be useful in marker-assisted selection (MAS) to increase the frequency of favorable allele(s) in resource populations (reviewed in Soller 1994). In addition, mapping of these loci creates the opportunity to identify gene(s) influencing a trait, through positional cloning or positional cnadidate gene approaches (Grootscholten et al. 1991). A positional cloning strategy requires the construction of contigs that physically span large sections of chromosomes. In the human and mouse systems, contig construction has depended on the availability of multiple YAC libraries that provide depth of coverage to minimize the impact of chimeric and deleted clones inherent in these libraries. A single porcine genomic YAC library has been reported (Leeb et al. 1995), but contains only one genome coverage, which limits the ability to make large contigs. We report the construction of a porcine YAC library, with approximately 5.5-fold coverage of the genome and a low rate of chimerism, that provides an additional resource for contig construction and positional cloning