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The g-proteobacterium Shewanella oneidensis MR-1 reduces a wide range of terminal electron acceptors, including solid Fe(III) oxides. Pathways for Fe(III) oxide reduction by S. oneidensis include non-reductive (organic ligand-promoted) solubilization reactions, and either direct enzymatic, or indirect electron shuttling pathways. Results of the present study expand the spectrum of electron acceptors reduced by S. oneidensis to include the naturally occurring disulfide compounds cystine, oxidized glutathione, dithiodiglycolate, dithoidiproponiate and cystamine. Subsequent electron shuttling experiments demonstrated that S. oneidensis employs the reduced (thiol) form of the disulfide compounds (cysteine, reduced glutathione, mercaptoacetate, mercaptopropionate, and 2-nitro-5-thiobenzoate, cystamine) as electron shuttles to transfer electrons to extracellular Fe(III) oxides. The results of the present study indicate that microbial disulfide reduction may represent an important electron-shuttling pathway for electron transfer to Fe(III) oxides in anaerobic marine and freshwater environments.

The existence of a significant non-baryonic component to the Universe is widely accepted, with worldwide efforts underway trying to detect this so-called dark matter. The ZEPLIN-III detector utilises liquid xenon (Xe) as a target medium in the search for the expected rare interactions of Weakly Interacting Massive Particles, or WIMPs, with ordinary baryonic matter. The neutralino, arising in supersymmetric extensions to the standard model of particle physics, provides a particularly well-motivated candidate. The ZEPLIN-III experiment, operating in two-phase (liquid/gas) mode, measures both the scintillation and ionisation signatures produced during an interaction. The first science run (FSR) of ZEPLIN-III was performed during three months in 2008. The run culminated in a published result which excluded a WIMP-nucleon interaction cross-section above 8:1 x 10-8 pb for a 60 GeVc-2 WIMP at the 90% confidence level. ZEPLIN-III then entered an upgrade period where the photomultiplier tube (PMT) array, previously the dominant source of background, was replaced with new, ultra-low background, PMTs. The radio-contamination of components used to make these PMTs has been thoroughly studied and their impact on the background rates in ZEPLIN-III characterised. Additionally, a new 1.5 tonne plastic scintillator veto detector was constructed, increasing the ability to reject WIMPlike signals caused by neutron induced nuclear recoil events and improving the γ-ray discrimination capability of ZEPLIN-III. The second science run (SSR) of ZEPLIN-III began in June 2010 and continued for 6 months, with a projected upper limit for the interaction cross-section of 1:52 x 10-8 pb for a 55 GeVc-2 WIMP at the 90% confidence level.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper will discuss the functions performed by the Spatial Infrared Imaging Telescope (SPIRIT) III Data Processing Center (DPC) at Utah State University (USU). The SPIRIT III sensor is the primary instrument on the Midcourse Space Experiment (MSX) satellite; and as builder of this sensor system, USU is responsible for developing and operating the associated DPC. The SPIRIT III sensor consists of a six-color long-wave infrared (LWIR) radiometer system, an LWIR spectrographic interferometer, contamination sensors, and housekeeping monitoring systems. The MSX spacecraft recorders can capture up to 8+ gigabytes of data a day from this sensor. The DPC is subsequently required to provide a 24-hour turnaround to verify and qualify these data by implementing a complex set of sensor and data verification and quality checks. This paper addresses the computing architecture, distributed processing software, and automated data verification processes implemented to meet these requirements.

In New Zealand, Māori currently experience the "poorest health status of any ethnic group" characterised by high rates of physical and mental illness, educational underachievement, unemployment, criminal incarceration, and low socioeconomic status (Durie, 1998; Ministry of Health, 1999, 2002a, p. 2). Despite attempts to reduce the disparities between Māori and other New Zealanders, Māori continue to have a lower life expectancy than non-Māori (Durie, 1998; Reid, 1999). Māori children show similar levels of disadvantage experiencing high rates of illness and preventable death (Ministry of Health, 1998). Māori children also achieve poorly in educational settings, with literacy levels and overall involvement in education found to be below that of non-Māori (Ministry of Education, 2003a). Research findings have identified that health and educational disparities may be explained in part, by a mismatch between current approaches to practice and service delivery, and the values, beliefs, and experiences of Māori (Phillips, McNaughton, & MacDonald, 2004). In line with such findings, a number of standardised psychometric tests developed outside of New Zealand, have also been found to produce culturally biased results when used with Māori (Ogden, 2003; Ogden & McFarlane-Nathan, 1997). The Peabody Picture Vocabulary Test (PPVT-III) is one such test which is currently used in New Zealand to measure receptive vocabulary skills (Stockman, 2000). This research investigated the suitability of the PPVT-III with 46 Māori children from three different age groups. Results revealed that the PPVT-III appeared to be suitable for use with Māori, although a number of suggestions were made as to ways in which the administration and interpretation of PPVT-III test scores could be adjusted when working with Māori. Additional research is required to establish whether changes to culturally biased items may improve the validity of the PPVT-III for use with Māori.

One of the most fundamental aspects of extracorporeal membrane oxygenation (ECMO) is maintaining proper anticoagulation management in order to prevent hemorrhagic or thrombotic events. Anticoagulation on ECMO is most commonly achieved with the use of unfractionated heparin to maintain a minimum anticoagulation level as monitored by activated clotting time (ACT). Heparin's main effect is exerted by binding to and potentiating antithrombin III. Many factors may contribute to a sub-therapeutic ATIII level that may decrease the effectiveness of heparin. A retrospective record review was performed on all adult ECMO patients at the University of Arizona Medical Center between 2008 and 2011, in order to determine optimal ATIII levels for maintaining proper anticoagulation. In addition, we investigated correlations between ATIII levels and hemorrhagic and/or thrombotic events. Variables measured include, ACTs, heparin dose, ATIII dose, ATIII levels, blood product use, and adverse events. Thirty-five patients received ATIII over the course of the ECMO run. Six patients did not receive ATIII and they were found to have used significantly more blood products than those who did receive ATIII. Also, heparin dose dropped significantly 24h after the first dose of ATIII. There is a significant positive correlation between the amount of ATIII given per day and the amount of packed red blood cells transfused per day. The results suggest an ideal therapeutic range of ATIII dosing, where lack of or too much ATIII administration can lead to excessive bleeding.

Cold dark matter in the form of weakly interacting massive particles (WIMPs) is a favoured explanation to the galactic dark matter puzzle and could account for a large proportion of the missing mass of the Universe. There are currently numerous detectors around the world attempting to observe a WIMP signal. The ZEPLIN-III detector is one such device. Utilising liquid xenon as a target medium, identification is based on extraction of scintillation and electroluminescence signals from the two-phase xenon target caused when WIMPs scatter and has recently completed its first science run (FSR). With no WIMP signal observed, ZEPLIN-III has excluded a WIMP-nucleon spin-independent cross section above 8.1 × 10−8 pb (90% confidence limit) for a WIMP mass of 60 GeV/c2 and also set a 90% confidence upper limit of a pure WIMP-neutron spin-dependent cross section of 1.9 × 10−2 pb for a 55 GeV/c2 WIMP mass. However, the focus of this thesis is the future of the ZEPLIN-III detector with regards to the second science run (SSR). As with all dark matter detectors, background reduction from neutrons and gamma-rays plays a significant part in obtaining competitive WIMP detection sensitivities. The author has contributed significantly to the design, development and testing of a low radioactivity veto for the ZEPLIN-III detector, to be retrofitted in time for the SSR. It will detect neutrons and gamma-rays in coincidence with the ZEPLIN-III target allowing these events to be removed as candidate WIMP events. This thesis describes the author’s contribution to the design, construction, testing and evaluation of the veto. Also discussed is the development of a comprehensive Monte Carlo simulation, utilised to aid in the design process, to determine the background rates emanating from the veto components (and therefore possible impact on the low sensitivity running of ZEPLIN-III), and to provide an accurate estimation of the overall veto efficiency to reject coincident neutrons and gamma-rays. The veto will have a neutron rejection factor of 67%, reducing the expected neutron background in ZEPLIN-III from 0.4 neutrons/year to 0.14 neutrons/year, a significant factor in the event of a possible WIMP observation. In addition to the work performed on the ZEPLIN-III veto, the author has also contributed to the first science run analysis program by profiling the historical evolution of the electron lifetime throughout the FSR, and implementing consideration of this to improve the data quality.

The first stars, galaxies and black holes in the universe produced large quantities of ionising UV radiation; forming H II regions in the neutral gas before the Epoch of Reionisation (EoR). These ionisation fronts will have come into contact with overdensities in the surrounding Intergalactic Medium (IGM), including haloes which were in the process of collapse. Previous studies have shown that the feedback processes on these secondary haloes can either disrupt the gas, or induce further cooling from the formation of molecular hydrogen. The ionising source will eventually die and create a defunct H II region, which expands into the surrounding neutral IGM. Minihaloes at the edge of these defunct H II regions are particularly susceptible to positive feedback due to not having been photoevaporated like their counterparts further inside the ionised volume. In this thesis, numerical simulations of minihaloes at the edges of H II regions formed by the first luminous objects before the EoR are presented. A methodology of including secondary ionisations from high energy photons is also implemented into the radiation hydrodynamical code ZEUS-RT. The interaction of differing spectral index sources with minihaloes including secondary ionisation is discussed. The secondary ionisations show the greatest effect for hard spectral sources with a large fraction of high energy photons; where a decrease in photoheating and an increase in ionisation rate is found at the outer reaches of the ionisation front (I-front). The increased ionisation rate lowers the optical depth of the gas for subsequent photons, and thus reduces the trapping of I-fronts in high densities found in the minihalo cores. The ratio of the free electron fraction to the temperature in the core of the minihaloes is found to constrain the resulting evolution. A high ratio is correlated with the creation of molecular hydrogen, which can then induce further cooling and the collapse of the system.A large parameter suite of 3780 two-dimensional minihalo models utilising radiative hydrodynamical simulations with 12 species and a coupled reaction network, including H2 cooling, HD cooling, Lyman-Werner radiation and secondary ionisation is performed. The parameter space includes: the spectral index representing different sources such as quasars or galaxies, the mass of the minihaloes from 105 - 106 Mʘ, the redshift of ionisation from z ~ 10 - 30, and other factors which denote the position of the minihalo relative to the boundary of the H II region. Minihaloes with average core densities of n0 = 2 - 10 cm-3 show almost unanimous positive feedback, while the majority of minihaloes under this average density are disrupted. Minihaloes with core densities above this value generally would have collapsed in isolation anyway, but are found to not be delayed by the I-front. The H2 fraction in the minihalo gas is also increased in models with no blowout by factors between 2 - 100 times that of an isolated minihalo. This is especially significant for lower redshift, z ≤ 15, minihaloes. Finally, a parameter suite of larger 106 - 107 Mʘ minihaloes results in the creation of self-gravitating clumps of gas moving out of the dark matter potential. The gas core is compressed by the I-front, enriched with molecular hydrogen, and ejected by the pressure front after the source dies. These "baryon bullets" could be progenitors of primordial globular clusters found in the haloes of galaxies today. Properties such as old stellar populations and the lack of dark matter haloes can be explained by this radiative ejection method. The dynamical nature of these interacting systems and diversity of subsequent evolution suggest that minihaloes less than 108 Mʘ are important in the early formation history of the universe, and in determining the constraining parameters of the EoR. The feedback mechanisms investigated, and secondary ionisation physics, should be included in astrophysical simulations and analytical calculations determining the evolution of the universe at this critical epoch.

Trabajo de Investigación Requisito para optar al Título de Cirujano Dentista / Introducción Los biotipos faciales determinan características morfológicas, funcionales, craneofaciales y oclusales del sistema estomatognático, tienen valor en el diagnóstico y plan de tratamiento de diversas discrepancias craneofaciales y dentales y permiten predecir la dirección de crecimiento máxilofacial. Entre los métodos cefalométricos más usados para la determinación del biotipo facial encontramos el Polígono de Björk – Jarabak y el Vert de Ricketts. En éste último, los factores profundidad facial y eje facial, ubicados en la sínfisis mentoniana, pueden verse altamente afectados según la clase esqueletal del paciente. Esto conlleva a que los análisis cefalométricos relacionados con planos que utilizan estos puntos puedan perder aplicabilidad en el diagnóstico del biotipo facial. El presente trabajo propone una modificación al método biotipológico del Vert, eliminando los factores en cuestionamiento, estableciendo así un estudio comparativo con el Vert de Ricketts con respecto a la concordancia diagnóstica del biotipo facial con el método Polígono de Björk-Jarabak en pacientes clase III esqueletal severa. Materiales y Métodos Se utilizaron 60 teleradiografías de perfil, 52 digitales y 8 convencionales. Para los trazados y mediciones cefalométricas se trabajó con el programa computacional NemoCeph ® . Los análisis de concordancia diagnóstica fueron realizados con la prueba kappa de Cohen. Resultados La distribución biotipológica con el método Polígono Björk Jarabak fue de dolicofacial 12%, mesofacial 65%, braquifacial 23%, con Vert de Ricketts dolicofacial 22%, mesofacial 22%, braquifacial 56% y dolicofacial 55%, mesofacial 18%, braquifacial 27% con el método Vert modificado. Ambos métodos Vert 8 tuvieron una concordancia aceptable y significativa (p<0,0005) con el método Polígono de Björk Jarabak. Conclusiones Se rechaza la hipótesis de que el Polígono de Björk Jarabak tiene una mayor concordancia diagnóstica con el método Vert modificado que con el Vert de Ricketts. Al eliminar los factores cefalométricos en cuestionamiento, profundidad facial y eje facial, en la muestra predominó el biotipo dólicofacial, mientras que al ser incluidos estos factores en el análisis, la mayoría de los biotipos fueron braquifaciales, de lo cual se desprende que estos dos factores tienen una notoria influencia en el diagnóstico del biotipo.

Changes in the marine environment have been reported for over three decades in terms of mean annual wave heights, exceedance probabilities and extreme conditions. More recently, the existence of a link between these changes and anthropogenic climate change has been postulated. This is not unreasonable, as climatic changes in regional warming and cooling are likely to alter wind patterns, and therefore the wave climate as well. In an attempt to mitigate climate change and increase energy security, the offshore environment is being looked at to provide sustainable energy from wind, waves and tides. As a result the number of marine structures is only likely to increase. While survivability in this environment is essential for all such installations, some devices such as wave energy converters also rely on the environment for energy production. In designing these offshore structures to survive the harshest conditions as well as to ensure optimum operation, knowledge of the evolution of the wave climate is essential. This study aims to identify and evaluate any historical trends that may be exhibited by the wave climate in the North East Atlantic and North Sea region. The study also aims to investigate the link between any observed changes and atmospheric greenhouse gas levels and projected wave conditions for the 21st century. This is achieved by producing a long-term, high resolution hindcast of wave conditions for 1871-2010 using the third-generation spectral wave model WAVEWATCH III. A dataset of wave climate projections for the high, medium and low emissions scenarios is also prepared by forcing the model with GCM winds for 2001-2100. In addition to dynamically projecting the wave climate in the 21st century for different IPCC climate change scenarios, statistical methods were applied to historic data to estimate extreme events in terms of 100-year return values of significant wave height. These, together, provide some idea of the plausible wave climate up to 2100. The results of the work show the existence of long-term trends in the historical wave climate in the region from 1921 onwards. However, based on the findings of the study, it is unlikely that these are a result of changes in atmospheric greenhouse gas concentrations and are more likely due to internal variability in the system.