NLO predictions for a lepton, missing transverse momentum and dijets at the Tevatron

n this letter we investigate the various processes that can contribute to a final state consisting of a lepton, missing transverse momentum and two jets at Next to Leading Order (NLO) at the Tevatron. In particular we consider the production of W/Z + 2 jets, diboson pairs, single top and the tt process with both fully leptonic and semi-leptonic decays. We present distributions for the invariant mass of the dijet system and normalisations of the various processes, accurate to NLO.Comment: 4 pages, 5 figure

Does "Fight or Flight" Need Updating?

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ePortfolios: Helping Students Take Control of Their Learning

With the addition of new technology to the classroom teachers have many new tools for the student to use. ePortfolios allow teachers to have student take control of their own learning while collecting their learning artifacts. This study looks at the impact of ePortfolios in the learning process at the high school level

“Inspiring Imps”: programme evaluation of a football intervention targeting mentally ill health services users through a professional football club

The Active People survey (2010) shows that only 6.5% of disabled individuals participate in sport and exercise 3 times per week, compared with 16.5% of able bodied adults in the UK. Individuals with recognised disabilities have long been excluded from mainstream society. Particularly in sport, disability athletes can be afforded minority status and are treated as such (Nixon, 2000: In Handbook of Sports Studies, edited by J. Coakley and E. Dunning. London: Sage). This stigmatisation can be particularly acute among participants with diagnosed mental or psychological disabilities. Previous research concluded that sport can have positive psychological and social benefits, including improved well-being, motivation and social confidence (Crone and Guy, 2008: International Journal of Mental Health Nursing. 17, 197-207.). The aim of the present study was to investigate the feasibility of a 6 week exercise programme targeting mental ill health service users aged 16+. A weekly 2 hour session of football was introduced to promote health and wellbeing in the target group. Partners included county Football Association and a professional football club. The project enhanced local partnerships and partnerships with other professional football clubs. The key remaining aim is to ensure a sustainable “legacy” is achieved to ensure the continuation delivery of the project. The feasibility of the present study will be assessed using programme evaluation. Programme evaluation uses programme theory to produce a structured framework for assessment of the project (Rossi et al 2004; Evaluation: A systematic Approach. London, Sage). This allows a clear and logical progression from planning to implementation. Participant attrition rates and attendance records will be collected. These data will be supplemented with semi-structured interviews with participants and project stakeholders to assess programme development. The expected overall project outcome is to produce shared learning practice on similar interventions nationwide

A hybrid multilevel converter for medium and high voltage applications

This paper investigates the suitability of the hybrid multilevel converter for medium and high voltage application. The converter operation, modulation, and capacitor voltage balancing method are described in detail. The ability of the hybrid multilevel converter to operate with different modulation indices and load power factors is investigated. It has been established that the hybrid multilevel converter is capable of operating independent of load power factor. Operation with variable modulation index increases voltage stresses on the converter switches and does not alter the fundamental voltage magnitude as in all known voltage source converter topologies. The viability of the hybrid multilevel converter for medium and high voltage applications is confirmed by simulations

Understanding user interactions in stereoscopic head-mounted displays

2022 Spring.Includes bibliographical references.Interacting in stereoscopic head mounted displays can be difficult. There are not yet clear standards for how interactions in these environments should be performed. In virtual reality there are a number of well designed interaction techniques; however, augmented reality interaction techniques still need to be improved before they can be easily used. This dissertation covers work done towards understanding how users navigate and interact with virtual environments that are displayed in stereoscopic head-mounted displays. With this understanding, existing techniques from virtual reality devices can be transferred to augmented reality where appropriate, and where that is not the case, new interaction techniques can be developed. This work begins by observing how participants interact with virtual content using gesture alone, speech alone, and the combination of gesture+speech during a basic object manipulation task in augmented reality. Later, a complex 3-dimensional data-exploration environment is developed and refined. That environment is capable of being used in both augmented reality (AR) and virtual reality (VR), either asynchronously or simultaneously. The process of iteratively designing that system and the design choices made during its implementation are provided for future researchers working on complex systems. This dissertation concludes with a comparison of user interactions and navigation in that complex environment when using either an augmented or virtual reality display. That comparison contributes new knowledge on how people perform object manipulations between the two devices. When viewing 3D visualizations, users will need to feel able to navigate the environment. Without careful attention to proper interaction technique design, people may struggle to use the developed system. These struggles may range from a system that is uncomfortable and not fit for long-term use, or they could be as major as causing new users to not being able to interact in these environments at all. Getting the interactions right for AR and VR environments is a step towards facilitating their widespread acceptance. This dissertation provides the groundwork needed to start designing interaction techniques around how people utilize their personal space, virtual space, body, tools, and feedback systems

Biophysical Studies of Cholesterol in Unsaturated Phospholipid Model Membranes

Cellular membranes contain a staggering diversity of lipids. The lipids are heterogeneously distributed to create regions, or domains, whose physical properties differ from the bulk membrane and play an essential role in modulating the function of resident proteins. Many basic questions pertaining to the formation of these lateral assemblies remain. This research employs model membranes of well-defined composition to focus on the potential role of polyunsaturated fatty acids (PUFAs) and their interaction with cholesterol (chol) in restructuring the membrane environment. Omega-3 (n-3) PUFAs are the main bioactive components of fish oil, whose consumption alleviates a variety of health problems by a molecular mechanism that is unclear. We hypothesize that the incorporation of PUFAs into membrane lipids and the effect they have on molecular organization may be, in part, responsible. Chol is a major constituent in the plasma membrane of mammals. It determines the arrangement and collective properties of neighboring lipids, driving the formation of domains via differential affinity for different lipids. The molecular organization of 1-[2H31]palmitoyl-2-eicosapentaenoylphosphatidylcholine (PEPC-d31) and 1-[2H31]palmitoyl-2-docosahexaenoylphosphatidylcholine (PDPC-d31) in membranes with sphingomyelin (SM) and chol (1:1:1 mol) was compared by solid-state 2H NMR spectroscopy. Eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are the two major n-3 PUFAs found in fish oil, while PEPC-d31 and PDPC-d31 are phospholipids containing the respective PUFAs at the sn-2 position and a perdeuterated palmitic acid at the sn-1 position. Analysis of spectra recorded as a function of temperature indicates that in both cases, formation of PUFA-rich (less ordered) and SM-rich (more ordered) domains occurred. A surprisingly substantial proportion of PUFA was found to infiltrate the more ordered domain. There was almost twice as much DHA (65%) as EPA (30%). The implication is that n-3 PUFAs can incorporate into lipid rafts, which are domains enriched in SM and chol in the plasma membrane, and potentially disrupt the activity of signaling proteins that reside therein. DHA, furthermore, may be the more potent component of fish oil. PUFA-chol interactions were also examined through affinity measurements. A novel method utilizing electron paramagnetic resonance (EPR) was developed, to monitor the partitioning of a spin-labeled analog of chol, 3β-doxyl-5α-cholestane (chlstn), between large unilamellar vesicles (LUVs) and methyl-β-cyclodextrin (mβCD). The EPR spectra for chlstn in the two environments are distinguishable due to the substantial differences in tumbling rates, allowing the population distribution ratio to be determined by spectral simulation. Advantages of this approach include speed of implementation and avoidance of potential artifacts associated with physical separation of LUV and mβCD. Additionally, in a check of the method, the relative partition coefficients between lipids measured for the spin label analog agree with values obtained for chol by isothermal titration calorimetry (ITC). Results from LUV with different composition confirmed a hierarchy of decreased sterol affinity for phospholipids with increasing acyl chain unsaturation, PDPC possessing half the affinity of the corresponding monounsaturated phospholipid. Taken together, the results of these studies on model membranes demonstrate the potential for PUFA-driven alteration of the architecture of biomembranes, a mechanism through which human health may be impacted