A review of central production experiments at the CERN Omega spectrometer

The non-Abelian nature of QCD suggests that particles that have a gluon constituent, such as glueballs or hybrids, should exist. This paper presents a study of central meson production in the fixed target experiments WA76, WA91 and WA102 at the CERN Omega spectrometer at centre-of-mass energies of $\sqrt{s} = 12.7$, 23.8 and 29~GeV. A study of the resonance production cross section as a function of $\sqrt{s}$ shows which states are compatible with being produced by Double Pomeron Exchange (DPE). In these DPE processes, the difference in the transverse momentum between the exchange particles ($dP_T)$ can be used to select out known $q\overline q$ states from non-$q \overline q$ candidates. The distribution of the azimuthal angle ($\phi$) between the two exchange particles suggests that the Pomeron transforms like a non-conserved vector current. Finally there is evidence from an analysis of the the decay modes of the scalar states observed, that the lightest scalar glueball manifests itself through the mixing with nearby $q\overline q$ states.Comment: 14 pages, 8 figures. arXiv admin note: text overlap with arXiv:hep-ph/000805

Finding frames: new ways to engage the UK public in global poverty

The aim of the study was to explore the potential for frames theory to be used as a practical tool to re-engage the UK public in global poverty. In exploring the uses of frames theory, we have built on work by Tom Crompton at WWF-UK, who began the task of linking values to frames and thereby suggesting new ways forward for engaging the public in environmental issues and actions. An important finding from his Common Cause paper is that there is a common set of values that can motivate people to tackle a range of ‘bigger than self’ problems, including the environment and global poverty. The implication is that large coalitions can – and must – be built across third- sector organisations to bring about a values change in society. This report responds to that call. The basic argument of this paper is that there is a problem in terms of the UK public’s levels of engagement with global poverty. Simply put, people in the UK understand and relate to global poverty no differently now than they did in the 1980s. This is the case despite massive campaigns such as the Jubilee 2000 debt initiative and Make Poverty History; the widespread adoption and mainstreaming of digital communication techniques and social networks; steady growth in NGO fundraising revenues; the entire Millennium Development Goal story; and the establishment of a Westminster consensus on core elements of development policy. By many measures we have made amazing strides forward in recent years, but the public have largely been left behind. The result is that we operate within social and, by extension, political conditions that are precarious in the immediate term and incommensurate to the challenges of poverty and climate change in the medium and long term. This study looks at what can be learned from values (the guiding principles that individuals use to judge situations and determine their courses of action) and frames (the chunks of factual and procedural knowledge in the mind with which we understand situations, ideas and discourses in everyday life). Values and frames offer ways to look at the problem of public engagement with global poverty and to identify possible solutions. If we apply values and frames theory to the question of how to re-engage the public, we come up with some compelling insights into the impact of our existing practices and some striking solutions to the problems that these reveal. They may not be perfect solutions, and they bring with them significant challenges. But we believe they offer something valuable and timely: a fresh perspective. The persistent problem of public engagement suggests it is time for the development sector to transform its practices radically. Values and frames offer pathways to potential solutions that should be debated across the sector, and no

Performance of Hollow Load Process Challenge Devices (HLPCDs) for the determination of air removal and steam penetration in porous load steam sterilization processes: Part 1 – The evolution of HLPCDs in standards and a review of the current supporting published evidence

Steam sterilization Process Challenge Devices (PCDs) are devices which present a defined challenge to a sterilization process. In part one of a two part series the authors review the published literature covering studies evaluating the removal of air and penetration of steam into hollow tubular devices and then discuss the relevance of the material in support of the current custom and practice of utilising simple tubular PCDs (Hollow Load Process Challenge Devices HLPCDs) as a means of monitoring production loads for adequacy of air removal and steam penetration. This review places such data in the context of the evolution of HLPCDs in the standards for small and large porous load steam sterilizers. With regard to the apparent acceptance of the HLPCD in EN 867-5 into custom and practice for batch monitoring the literature suggests this may be misleading. The literature review concludes that there is an urgent need for an International Standard which describes how a HLPCD can be developed and tested against real medical devices in a range of sterilization processes representing current state of the art in full load conditions

The relationship between cell size and cell fate in Volvox carteri

In Volvox carteri development, visibly asymmetric cleavage divisions set apart large embryonic cells that will become asexual reproductive cells (gonidia) from smaller cells that will produce terminally differentiated somatic cells. Three mechanisms have been proposed to explain how asymmetric division leads to cell specification in Volvox: (a) by a direct effect of cell size (or a property derived from it) on cell specification, (b) by segregation of a cytoplasmic factor resembling germ plasm into large cells, and (c) by a combined effect of differences in cytoplasmic quality and cytoplasmic quantity. In this study a variety of V. carteri embryos with genetically and experimentally altered patterns of development were examined in an attempt to distinguish among these hypotheses. No evidence was found for regionally specialized cytoplasm that is essential for gonidial specification. In all cases studied, cells with a diameter > approximately 8 microns at the end of cleavage--no matter where or how these cells had been produced in the embryo--developed as gonidia. Instructive observations in this regard were obtained by three different experimental interventions. (a) When heat shock was used to interrupt cleavage prematurely, so that presumptive somatic cells were left much larger than they normally would be at the end of cleavage, most cells differentiated as gonidia. This result was obtained both with wild-type embryos that had already divided asymmetrically (and should have segregated any cytoplasmic determinants involved in cell specification) and with embryos of a mutant that normally produces only somatic cells. (b) When individual wild-type blastomeres were isolated at the 16-cell stage, both the anterior blastomeres that normally produce two gonidia each and the posterior blastomeres that normally produce no gonidia underwent modified cleavage patterns and each produced an average of one large cell that developed as a gonidium. (c) When large cells were created microsurgically in a region of the embryo that normally makes only somatic cells, these large cells became gonidia. These data argue strongly for a central role of cell size in germ/soma specification in Volvox carteri, but leave open the question of how differences in cell size are actually transduced into differences in gene expression

Teaching Computers to Think: Analysis of Artificial Intelligence and Connect Four

Connect Four is a classic two person, zero-sum game in which players utilize their wits and gravity to connect four of their own pieces in a horizontal, vertical, or diagonal row while blocking their opponent’s attempt to do the same. We have constructed a simulation of this game which we have used as a base for the implementation and testing of varying Artificial Intelligence (AI) systems. Early strategies worked according to simple strategic methods, while more advanced heuristics employed a Min-Max Tree in tandem with methods to determine how advantageous a certain board would be. This Min-Max Tree goes beyond a simple strategy, as it allows for the computer to look many moves ahead, thus picking the move that optimizes its chances of winning. The collection of statistics for the various strategies has allowed for the analysis and improvement of the AI structures

MOISTURE AND UNIT WEIGHT READINGS FROM A COMPLEX IMPEDANCE MEASURING INSTRUMENT

Complex Impedance Measuring Instruments (CIMI’s) are non-nuclear devices that calculate the dry unit weight and moisture content of soil by means of electromagnetic wave propagation theory. Unlike nuclear based test devices, these devices do not require certification or elaborate maintenance to own and operate. CIMI operation requires a soil specific calibration process where soil moisture and unit weight are correlated to electrical parameters. A new, smaller acrylic mold was developed as an alternative calibration tool to the manufacturer’s recommended mold. Calibrated soil models were generated using manufacturer recommended procedures as well as new procedures involving an acrylic mold. Models were then tested for accuracy. The new procedure outperformed the manufacturer’s procedure. Another small, acrylic mold was used to investigate the relationship between CIMI readings and soil parameters. Using several samples from four soils, the relationship between moisture, unit weight, and some electrical parameters was characterized. This characterization was then used to create a new, accurate calibration procedure

Sparse Matrix Sparse Vector Multiplication using Parallel and Reconfigurable Computing

The purpose of this thesis is to provide analysis and insight into the implementation of sparse matrix sparse vector multiplication on a reconfigurable parallel computing platform. Common implementations of sparse matrix sparse vector multiplication are completed by unary processors or parallel platforms today. Unary processor implementations are limited by their sequential solution of the problem while parallel implementations suffer from communication delays and load balancing issues when preprocessing techniques are not used or unavailable. By exploiting the deficiencies in sparse matrix sparse vector multiplication on a typical unary processor as a strength of parallelism on a Field Programmable Gate Array (FPGA), the potential performance improvements and tradeoffs for shifting the operation to hardware assisted implementation will be evaluated. This will simply be accomplished through multiple collaborating processes designed on an FPGA