The antibiotic sensitivity patterns and plasmid DNA content of gram-negative anaerobic bacteria isolated in Palmerston North, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Masters in Science at Massey University

One hundred and seven Gram-negative bacteria, including 65 Bacteroides species, 28 fusobacteria and 14 veillonellae were isolated from 17 oral infections treated in two dental surgeries in Palmerston North. These bacteria, plus 37 isolates belonging to the B. fragilis group received from Palmerston North hospital, were surveyed for their antibiotic sensitivity levels, and their plasmid DNA content. The hospital isolates of the B. fragilis group were found to have sensitivity levels comparable with those of B. fragilis group isolates reported in the literature recently. The oral isolates were more sensitive to penicillin, cefoxitin, and tetracycline than isolates of the same species reported in the literature. Half the hospital isolates had plasmids, which were all between 8.5 and 2.7 kilobases (kb) in size except for one 60, and one 43 kb plasmid. Comparatively few of the oral anaerobes had plasmids. One Fusobacterium russii isolate had four plasmids, and five Bacteroides isolates had one plasmid each. These five Bacteroides isolates came from two specimens, R5 and R6. Restriction enzyme analysis of all plasmids revealed that the three 5.6 kb plasmids from sample R5 may be related to a group of 5.8 kb plasmids harboured by four of the hospital isolates. Two different species of Bacteroides isolated from sample R5 harboured the 5.6 kb plasmid, and two species of the B. fragilis group bacteria harboured the 5.8 kb plasmid. Plasmid DNA isolated from two tetracycline resistant hospital isolates was used to transform restriction negative E. coli to a low level of tetracycline resistance

The Dynamic Performance of Cavitating Turbopumps

Knowledge of the dynamic performance of turbopumps is essential for the prediction of instabilities in hydraulic systems; the necessary information is in the form of a transfer function relating the instantaneous pressures and mass flow rates at inlet and discharge. Cavitation has a significant effect on this transfer function since dynamical changes in the volume of cavitation contribute to the difference in the instantaneous flow rates. The present paper synthesizes the transfer matrix for cavitating inducers at moderately low frequencies and shows that the numerical results are consistent with observations on rocket engine turbopumps

Comparing Carbon Footprint Methodologies for SMEs

Carbon footprints are useful and important tools in the fight against climate change, which are now being used widely by larger companies. These large corporations have recognised not only their use as an environmental tool but also their potential to attract customers and reduce costs. However, this is not yet the case for many smaller companies who still consider environmental assessment to be a burden which is too difficult and costly to undertake. In order to encourage small and medium sized enterprises (SMEs) to take more responsibility for their environmental impact, a carbon footprint tool needs to be developed specifically for them, which addresses their particular requirements, namely their lack of knowledge of environmental issues and their lack of time and money. There are currently two basic methodological approaches to produce the conversion factors required to convert quantitative values of material used into the amount of carbon dioxide (CO2) produced by that material usage. One methodology is called lifecycle analysis (LCA) as it looks at all the steps individually throughout the lifecycle of a product and adds them together to form an overall picture. The other, called environmental input output analysis (EIO), uses economic purchase and sales data combined with sector emissions to derive conversion factors based on the amount of money spent within a different sector. This study compares both of these methodologies to determine which of them is most suitable to use in the development of a tool for SMEs. Two tools were created, one based upon each methodology. The most noticeable difference between these two tools was that whereas the LCA tool asked for information in terms of the quantity of a material used, the EIO tool asked for information about the amount of money spent within a sector

Fluid-induced Rotordynamic Forces and Instabilities

In the late 1970s, the authors began a collaboration with our colleague Tom Caughey that helped define a new set of fluid-structure interaction phenomena in turbomachines, namely fluid-induced rotordynamic forces and instabilities. That collaboration and the 31 joint ABC papers it produced epitomized Tom Caughey's genius and we reprise it here in his honor. The design of the space shuttle main engine (SSME) pushed beyond the boundaries of many known technologies. In particular, the rotating speeds and operating conditions of the high speed liquid oxygen and liquid hydrogen turbopumps were extreme and early testing revealed a whirl instability whose magnitude exceeded expectations and allowable limits. It was suspected and later proven that fluid-induced rotordynamic effects were a contributing factor and yet very little was known of such phenomena. As one of the efforts seeking understanding, we constructed a facility to measure fluid-induced rotordynamic forces. This was subsequently used in a broad range of investigations. Initially, the effort was directed to understanding the source and parametric variations of destabilizing fluid forces. Later various components of the flow in a high speed turbopump were investigated. And finally, some ameliorative measures and their effectiveness were examined. This paper reviews this body of knowledge and the lessons learnt along the way

SME application of LCA-based carbon footprints

Following a brief introduction about the need for businesses to respond to climate change, this paper considers the development of the phrase ‘carbon footprint’. Widely used definitions are considered before the authors offer their own interpretation of how the term should be used. The paper focuses on the contribution small and medium sized enterprises (SMEs) make to the economy and their level of influence in stimulating change within organisations. The experience of an outreach team from the Engineering Department of a UK university is used which draws on the experience of delivering regional economic growth projects funded principally through the European Regional Development Fund. Case studies are used including the development of bespoke carbon footprints for SMEs from an initiative delivered by the outreach team. Limitations of current carbon footprints are identified based on this higher education-industry knowledge exchange mechanism around three main themes of scope, the assessment method and conversion factors. Evidence and discussions are presented that conclude with the presentation of some solutions based on the work undertaken with SMEs and a discussion on the merits of the two principally used methodologies: life-cycle analysis and economic input–output assessment

An investigation of potential kinematic factors associated with patellofemoral pain syndrome during running

Includes abstract.Includes bibliographical references.Patellofemoral pain syndrome (PFPS) is a common clinical condition affecting physically active individuals. It is characterised by pain behind or around the patella during loading of the lower limb. It is recognised that there are multiple factors that contribute to PFPS; however these factors are not well understood. There is equivocal evidence for differences in lower limb kinematics in participants with PFPS, particularly during the running gait cycle. The aim of this study was to investigate lower extremity kinematics during running in individuals with a history of PFPS compared to those without symptoms. Specific objectives: (a) To describe lower extremity kinematics during running for individuals with PFPS. (b) To determine whether there are differences in pelvis, hip, knee and ankle kinematics during running in participants with and without PFPS. (c) To determine whether there were any kinematic variables at the pelvis, hip and knee joint during stance phase of running that may be associated with an increased risk of developing PFPS. Methods: This study had a descriptive cross-sectional study design. Thirty one physically active individuals, who participated in at least two hours of physical activity per week for at least three months prior to testing, were recruited for the study. Fifteen participants presented with PFPS, and 16 participants without PFPS formed the control group. Participants were also required to have a Q-angle within the normal range for males (8.2º-14.2º) and females (11.4º-20.3º) respectively. Participants in the PFPS group were required to have a history of unilateral anterior or retro-patellar pain of non-traumatic origin that did not exceed a six-month period prior to testing. The participants’ PFPS also needed to be elicited during one or more symptom provocation tests, namely: resisted terminal knee extension, stair descent, or a unilateral partial squat. The PFPS participants had to be able to run without pain for a minimum period of 10 minutes, which allowed the running test to be completed without reproducing symptoms of PFPS. All participants gave written informed consent before taking part in the study. Participants were familiarised with all testing procedures. Participants completed medical and training questionnaires, and body composition measurements were performed. Sixteen retro-reflective markers were placed on anatomical landmarks of the lower limbs according to the modified Helen Hayes marker set. Participants were then required to perform a running test, which consisted of 10 sets of running at a self-selected speed on a 10 m pathway. Kinematic data of the pelvis, hip, knee and ankle were recorded by an eight-camera motion analysis system during each repetition of the test. The specific data extracted included range of motion at heel strike and toe off, peak range of motion during swing phase and stance phase. In addition, the range of motion travelled during stance and swing phases and the percentage of stance phase a participant took to reach the peak range of motion during stance phase were calculated

Impeller-Induced Rotor-Dynamic Forces

The flow through and around the rotor of a turbomachine exerts a force on the rotor and, hence, rotor shaft and bearing system. In some circumstances this force may lead to excitation of shaft whirl in the direction of impeller rotation. Recent international research of this phenomenon is briefly reviewed; these findings suggest that turbomachines intended to operate well above the first critical speed should take the effect into account

Charged Schrodinger Black Holes

We construct charged and rotating asymptotically Schrodinger black hole solutions of IIB supergravity. We begin by obtaining a closed-form expression for the null Melvin twist of a broad class of type IIB backgrounds, including solutions of minimal five-dimensional gauged supergravity, and identify the resulting five-dimensional effective action. We use these results to demonstrate that the near-horizon physics and thermodynamics of asymptotically Schrodinger black holes obtained in this way are essentially inherited from their AdS progenitors, and verify that they admit zero-temperature extremal limits with AdS_2 near-horizon geometries. Notably, the AdS_2 radius is parametrically larger than that of the asymptotic Schrodinger space.Comment: 22 pages, LaTe

Forces on Centrifugal Pump Impellers

Forces are exerted on a centrifugal pump impeller, due to the asymmetry of the flow caused by the volute of diffuser, and to the motion of the center of the impeller whenever the shaft whirls. Recent work in the measurement of these forces as a function of the whirl speed to shaft speed ratio, and the influence of the volute, is reviewed. These forces may be decomposed into a steady force, a static stiffness matrix, a damping matrix and an inertia matrix. It is shown that for centrifugal pumps of the moderate specific speed typical of boiler feed stages, there is a region of potential shaft vibration excitation from the hydrodynamic forces if the operating speed is well above the first flexural critical speed