995 resultados para Botterill, Jason


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A new experimental technique for femtosecond (fs) pulse studies of gas phase biomolecules is reported. Using Laser-Induced Acoustic Desorption (LIAD) to produce a plume of neutral molecules, a time-delayed fs pulse is employed for ionisation/fragmentation, with subsequent products extracted and mass analysed electrostatically. By varying critical laser pulse parameters, this technique can be used to implement control over molecular fragmentation for a range of small biomolecules, with specific studies of amino acids demonstrated.

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A low-cost field technique employing retention of the dye neutral-red by lysosomes in coelomocyte cells taken from earthworms (Lumbricus castaneus), was used as a means of assessing the ecological effects (if any) of an industrial accident. Earthworms and soil samples were collected at the site of a large industrial plastics fire in Thetford, UK along a 200 m transect leading from the factory perimeter fence, over a layer of molten plastic impregnated soil and into the surrounding forest. Coelomic fluid extracted from the earthworms was dye-loaded with neutral-red and lysosomal leaking observed. Metal residues in soil and earthworms were found to be highly elevated close to the factory perimeter and to rapidly drop to background levels within the first 50 m of the transect. Coelomocyte cells taken from earthworms adjacent to the factory perimeter showed the shortest period of neutral-red retention (2 min); cells taken from worms further into the surrounding forest had a longer retention time (12 min), whilst cells taken from worms from a control site showed even greater retention times (25 min). Thus, the neutral-red retention times correlated negatively with measured residues of heavy metals in the earthworms, the higher the body metal concentration the shorter the retention time. This field trial has demonstrated the validity of using an in vitro cellular biomarker technique for use in biological impact assessment along gradients of contamination.

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Automotive manufacturers require improved part load engine performance to further improve fuel economy. For a swing vane VGS (Variable Geometry Stator) turbine this means a more closed stator vane, to deal with the low MFRs (Mass Flow Rates), high PRs (Pressure Ratios) and low rotor rotational speeds. During these conditions the turbine is operating at low velocity ratios. As more energy is available at high pressure ratios and during lower turbocharger rotational speeds, a turbine which is efficient at these conditions is desirable. Another key aspect for automotive manufacturers is engine responsiveness. High inertia designs result in “turbo lag” which means an increased time before the target boost pressure is reached. Therefore, designs with improved performance at low velocity ratios, reduced inertia or an increased swallowing capacity are the current targets for turbocharger manufacturers.

To try to meet these design targets a CFD (Computational Fluid Dynamics) study was performed on a turbine wheel using splitter blades. A number of parameters were investigated. These included splitter blade merdional length, blade number and blade angle distribution.

The numerical study was performed on a scaled automotive VGS. Three different stator vane positions have been analysed. A single passage CFD model was developed and used to provide information on the flow features affecting performance in both the stator vanes and turbine.

Following the CFD investigation the design with the best compromise in terms of performance, inertia and increased MFP (Mass Flow Parameter) was selected for manufacture and testing. Tests were performed on a scaled, low temperature turbine test rig. The aerodynamic flow path of the gas stand was the same as that investigated during the CFD. The test results revealed a design which had similar performance at the closed stator vane positions when compared to the baseline wheel. At the maximum MFR stator vane condition a drop of −0.6% pts in efficiency was seen. However, 5.5% increase in MFP was obtained with the additional benefit of a drop in rotor inertia of 3.7%, compared to the baseline wheel.

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Off-design performance now plays a vital role in the design decisions made for automotive turbocharger turbines. Of particular interest is extracting more energy at high pressure ratios and lower rotational speeds. In this region of operation the U/C value will be low and the rotor will experience high values of positive incidence at the inlet. The positive incidence causes flow to separate on the suction surface and produces high blade loading at inlet, which drives tip leakage. A CFD analysis has been carried out on a number of automotive turbines utilizing non-radial fibred blading. To help improve secondary flows yet meet stress requirements a number of designs have been investigated. The inlet blade angle has been modified in a number of ways. Firstly, the blading has been adjusted as to provide a constant back swept angle in the span wise direction. Using the results of the constant back swept blading studies, the back swept blade angle was then varied in the span wise direction. In addition to this, in an attempt to avoid an increase in stress, the effect of varying the leading edge profile of the blade was investigated. It has been seen that off-design performance is improved by implementing back swept blading at the inlet. Varying the inlet angle in the span wise direction provided more freedom for meeting stress requirements and reduces the negative impact on blade performance at the design point. The blade leading edge profile was seen to offer small improvements during off-design operation with minimal effects on stress within the rotor. However, due to the more pointed nature of the leading edge, the rotor was less tolerant to flow misalignment at the design point.

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Conventionally, radial turbines have almost exclusively used radially fibred blades. While issues of mechanical integrity are paramount, there may be opportunities for improving turbine efficiency through a 3D blade design without exceeding mechanical limits. Off-design performance and understanding of the secondary flow structures now plays a vital role in the design decisions made for automotive turbocharger turbines. Of particular interest is extracting more energy at high pressure ratios and lower rotational speeds. Operating in this region means the rotor will experience high values of positive incidence at the inlet. A CFD analysis has been carried out on a scaled automotive turbine utilizing a swing vane stator system. To date no open literature exists on the flow structures present in a standard VGT system. Investigations were carried out on a 90 mm diameter rotor with the stator vane at the maximum, minimum and 25% mass flow rate positions. In addition stator vane endwall clearance existed at the hub side. From investigation of the internal flow fields of the baseline rotor, a number of areas that could be optimized in the future with three dimensional blading were identified. The blade loading and tip leakage flow near inlet play a significant role in the flow development further downstream at all stator vane positions. It was found that tip leakage flow and flow separation at off-design conditions could be reduced by employing back swept blading and redistributing the blade loading. This could potentially reduce the extent of the secondary flow structures found in the present study.

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Background:
Healthcare in Qatar is undergoing a period of major reform, driven by a strong economy and vision for a world-class healthcare system. One area identified as a potential contributor to developing a world-class healthcare system is interprofessional education (IPE), with the goal of facilitating healthcare workers to work together collaboratively. Several key steps have been taken towards developing IPE in Qatar, such as the formation of the Qatar Interprofessional Health Council (QIHC), the development of an IPE program for undergraduate healthcare students, the development of a set of shared core competencies, the receipt of substantial buy-in from leaders across the healthcare system, and recent approval of funding to develop a post-licensure healthcare IPE program. In order to improve IPE in Qatar, it is important to better understand the facilitators and barriers to interprofessional collaboration in Qatar. This study seeks to do so by qualitatively exploring facilitators and barriers to interprofessional collaboration for healthcare professional in Qatar from the perspective of health care professionals. By better understanding how health care workers give meaning to interprofessional education and collaboration, this research can assist in improving interprofessional activities in healthcare in Qatar.

Objectives
The purpose of this paper-presentation is to report on finding from a qualitative study that explored different facilitators and barriers of interprofessional practice in Qatar.

Method:
Ten healthcare professionals who work in Qatar were interviewed using semi-structured, open-ended interviews. Interview questions were organized by phenomenological (e.g. exploring the lived-experiences of healthcare workers) and ethnographic interviewing techniques (e.g. focusing on what people do). The questions explored the barriers, facilitators, and what is working well in terms of interprofessional practice for health care professional in Qatar.

Findings and Implications:
Different factors associated with interprofessional collaborations will be discussed. In doing so, this research adds to the literature on IPE by shedding light on interprofessional collaboration and education in the Middle East. Furthermore, this study identifies barriers for health care workers to work collaboratively in health care settings in Qatar. Addressing such barriers, and building off of what is working well, will facilitate Qatar in reaching one of the Vision 2030 goals of improving Qatar’s health and wellness.

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Background:

Healthcare in Qatar is undergoing a period of major reform, driven by a strong economy and vision for a world-class healthcare system. One area identified as a potential contributor to developing a world-class healthcare system is interprofessional education (IPE), with the goal of facilitating healthcare workers to work together collaboratively. Several key steps have been taken towards developing IPE in Qatar, such as the formation of the Qatar Interprofessional Health Council (QIHC), the development of an IPE program for undergraduate healthcare students, the development of a set of shared core competencies, the receipt of substantial buy-in from leaders across the healthcare system, and recent approval of funding to develop a post-licensure healthcare IPE program. In order to improve IPE in Qatar, it is important to better understand the facilitators and barriers to interprofessional collaboration in Qatar. This study seeks to do so by qualitatively exploring facilitators and barriers to interprofessional collaboration for healthcare professional in Qatar from the perspective of health care professionals. By better understanding how health care workers give meaning to interprofessional education and collaboration, this research can assist in improving interprofessional activities in healthcare in Qatar.

Objectives

The purpose of this paper-presentation is to report on finding from a qualitative study that explored different facilitators and barriers of interprofessional practice in Qatar.

Method:

Ten healthcare professionals who work in Qatar were interviewed using semi-structured, open-ended interviews. Interview questions were organized by phenomenological (e.g. exploring the lived-experiences of healthcare workers) and ethnographic interviewing techniques (e.g. focusing on what people do). The questions explored the barriers, facilitators, and what is working well in terms of interprofessional practice for health care professional in Qatar.

Findings and Implications:

Different factors associated with interprofessional collaborations will be discussed. In doing so, this research adds to the literature on IPE by shedding light on interprofessional collaboration and education in the Middle East. Furthermore, this study identifies barriers for health care workers to work collaboratively in health care settings in Qatar. Addressing such barriers, and building off of what is working well, will facilitate Qatar in reaching one of the Vision 2030 goals of improving Qatar’s health and wellness.

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Four new macrocyclic-phthalimide ligands were synthesised via the coupling of N-(3-bromopropyl)phthalimide either to cyclen (1,4,7,10- tetraazacyclododecane) itself or its carboxylate-functionalized analogues, and photophysical studies were carried out on their corresponding Tb(iii) complexes in aqueous media as a function of pH. Luminescence intensities of Tb·L1a-Tb·L3a were in 'switched off' mode under acidic conditions (pH < 4), and were activated on progression to basic conditions as the phthalimido functions therein were hydrolysed to their corresponding phthalamates Tb·L1b-Tb·L3b. Emission of phthalamate-based macrocyclic Tb(iii) complexes Tb·L 1b-Tb·L3b was in 'switched on' mode between pH 4 and 11, exhibiting high quantum yields (Φ) and long lifetimes (τ) of the order of milliseconds at pH ∼ 6. Tb(iii) emissions were found to decline with increasing number of chromophores. The values of Φ and τ were 46% and 2.4 ms respectively for Tb·L1b at pH ∼ 6 when activated. This is the best pH-dependent sensor based on a Tb(iii) complex reported to date, benefiting from the macrocyclic architecture of the ligand. © 2013 The Royal Society of Chemistry.

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A highly luminescent and sensitive terbium complex of a ligand comprising of a phthalimide group appended to a DO3A moiety is an active pH sensor that is conditional on its previous pH. © 2012 The Royal Society of Chemistry.

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Breast cancer is a heterogeneous disease and several distinct subtypes exist based on differential gene expression patterns. Molecular apocrine tumours were recently identified as an additional subgroup, characterised as oestrogen receptor negative and androgen receptor positive (ER- AR+), but with an expression profile resembling ER+ luminal breast cancer. One possible explanation for the apparent incongruity is that ER gene expression programmes could be recapitulated by AR. Using a cell line model of ER- AR+ molecular apocrine tumours (termed MDA-MB-453 cells), we map global AR binding events and find a binding profile that is similar to ER binding in breast cancer cells. We find that AR binding is a near-perfect subset of FoxA1 binding regions, a level of concordance never previously seen with a nuclear receptor. AR functionality is dependent on FoxA1, since silencing of FoxA1 inhibits AR binding, expression of the majority of the molecular apocrine gene signature and growth cell growth. These findings show that AR binds and regulates ER cis-regulatory elements in molecular apocrine tumours, resulting in a transcriptional programme reminiscent of ER-mediated transcription in luminal breast cancers.

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In this research, an agent-based model (ABM) was developed to generate human movement routes between homes and water resources in a rural setting, given commonly available geospatial datasets on population distribution, land cover and landscape resources. ABMs are an object-oriented computational approach to modelling a system, focusing on the interactions of autonomous agents, and aiming to assess the impact of these agents and their interactions on the system as a whole. An A* pathfinding algorithm was implemented to produce walking routes, given data on the terrain in the area. A* is an extension of Dijkstra's algorithm with an enhanced time performance through the use of heuristics. In this example, it was possible to impute daily activity movement patterns to the water resource for all villages in a 75 km long study transect across the Luangwa Valley, Zambia, and the simulated human movements were statistically similar to empirical observations on travel times to the water resource (Chi-squared, 95% confidence interval). This indicates that it is possible to produce realistic data regarding human movements without costly measurement as is commonly achieved, for example, through GPS, or retrospective or real-time diaries. The approach is transferable between different geographical locations, and the product can be useful in providing an insight into human movement patterns, and therefore has use in many human exposure-related applications, specifically epidemiological research in rural areas, where spatial heterogeneity in the disease landscape, and space-time proximity of individuals, can play a crucial role in disease spread.

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It is unknown how interventions aimed at increasing physical activity (PA), other than traditional pulmonary rehabilitation, are structured and whether they are effective in increasing PA in chronic obstructive pulmonary disease (COPD). The primary aim of this review was to outline the typical components of PA interventions in patients with COPD. This review followed the PRISMA guidelines. A structured literature search of relevant electronic databases from inception to April 2014 was undertaken to outline typical components and examine outcome variables of PA interventions in patients with COPD. Over 12000 articles were screened and 20 relevant studies involving 31 PA interventions were included. Data extracted included patient demographics, components of the PA intervention, PA outcome measures and effects of the intervention. Quality was assessed using the PEDro and CASP scales. There were 13 randomised controlled trials and three randomised trials (PEDro score 5-7/10) and four cohort studies (CASP score 5/10). Interventions varied in duration, number of participant/researcher contacts and mode of delivery. The most common behaviour change techniques included information on when and where (n = 26/31) and how (n = 22/31) to perform PA behaviour and self-monitoring (n = 18/31). Significant between-group differences post-intervention in favour of the PA intervention, compared to a control group or to other PA interventions, in one or more PA assessments were found in 7/16 studies. All seven studies used walking as the main type of PA/exercise. In conclusion, although the components of PA interventions were variable, there is some evidence that PA interventions have the potential to increase PA in patients with COPD