Probabilistic approach in weighted Markov branching processes

This note provides a new probabilistic approach in discussing the weighted Markov branching process (WMBP) which is a natural generalisation of the ordinary Markov branching process. Using this approach, some important characteristics regarding the hitting times of such processes can be easily obtained. In particular, the closed forms for the mean extinction time and conditional mean extinction time are presented. The explosion behaviour of the process is investigated and the mean explosion time is derived. The mean global holding time and the mean total survival time are also obtained. The close link between these newly developed processes and the well-known compound Poisson processes is investigated. It is revealed that any weighted Markov branching process (WMBP) is a random time change of a compound Poisson process.

Applying an Agility/Discipline Assessment for a Small Software Organisation

The adoption of agile software development methodologies may appear to be a rather straightforward process yielding instantly improved software in less time and increasingly satisfied customers. This paper will show that such a notion is a misunderstanding and can be harmful to small software development organisations. A more reasonable approach involves a careful risk assessment and framework for introducing agile practices to address specific risks. A case study with a small software development organisation is provided to show the assessment in practice and the resulting risk mitigation strategies for process improvement.

Tumor immunotherapy by epicutaneous immunization requires langerhans cells.

A role for Langerhans cells (LC) in the induction of immune responses in the skin has yet to be conclusively demonstrated. We used skin immunization with OVA protein to induce immune responses against OVA-expressing melanoma cells. Mice injected with OVA-specific CD8(+) T cells and immunized with OVA onto barrier-disrupted skin had increased numbers of CD8(+) T cells in the blood that produced IFN-gamma and killed target cells. These mice generated accelerated cytotoxic responses after secondary immunization with OVA. Prophylactic or therapeutic immunization with OVA onto barrier-disrupted skin inhibited the growth of B16.OVA tumors. LC played a critical role in the immunization process because depletion of LC at the time of skin immunization dramatically reduced the tumor-protective effect. The topically applied Ag was presented by skin-derived LC in draining lymph nodes to CD8(+) T cells. Thus, targeting of tumor Ags to LC in vivo is an effective strategy for tumor immunotherapy.

Personnel radiation dose considerations in the use of an integrated PET–CT scanner for radiotherapy treatment planning of an integrated PET-CT scanner for radiotherapy treatment planning

The acquisition of radiotherapy planning scans on positron emission tomography (PET)-CT scanners requires the involvement of radiotherapy radiographers. This study assessed the radiation dose received by these radiographers during this process. Radiotherapy planning F- fluorodeoxyglucose (F-FDG) PET-CT scans were acquired for 28 non-small cell lung cancer patients. In order to minimise the radiation dose received, a two-stage process was used in which the most time-consuming part of the set-up was performed before the patient received their F-FDG injection. Throughout this process, the radiographers wore electronic personal dosemeters and recorded the doses received at different stages of the process. The mean total radiation dose received by a radiotherapy radiographer was 5.1±2.6 mSv per patient. The use of the two-stage process reduced the time spent in close proximity to the patient by approximately a factor of four. The two-stage process was effective in keeping radiation dose to a minimum. The use of a pre-injection set-up session reduces the radiation dose to the radiotherapy radiographers because of their involvement in PET-CT radiotherapy treatment planning scans by approximately a factor of three.

Massage for symptom relief in patients with cancer: systematic review

Aim. This paper is a report of a review to assess evidence of the effectiveness of massage for patients with cancer, in terms of reducing physical or psychological symptoms, improving quality of life, or producing unwanted side effects. Background. Patients with cancer may use complementary therapies, including massage and aromatherapy massage. However, their use and provision by state-financed healthcare services is controversial. Data sources. A systematic review was carried out, using the Cochrane principles. No meta-analysis was appropriate. An initial comprehensive search of electronic databases search was carried out in 2003 and updated in 2006. Eligible trials were randomized controlled trials, controlled before-and-after (pre-post) studies and interrupted time-series studies. Participants were adults with a diagnosis of cancer and receiving care in any healthcare setting. Interventions were limited to massage and/or aromatherapy massage carried out by a qualified therapist. Outcome measures to be included were patient-reported levels of physical and psychological indices of symptom distress and quality of life (measured using validated assessment tools). Findings. In the review, 1325 papers were considered. Ten trials met the inclusion criteria and their results suggest that massage might reduce anxiety in patients with cancer in the short term and may have a beneficial effect on physical symptoms of cancer, such as pain and nausea. However, the lack of rigorous research evidence precludes drawing definitive conclusions. Conclusion. Further well-designed large trials with longer follow-up periods are needed to be able to draw firm conclusions about the efficacy and effectiveness of massage for cancer patients. © 2008 The Authors

Spray Congealed Lipid Microparticles with High Protein Loading: Preparation and Solid State Characterization

The spray-congealing technique, a solvent-free drug encapsulation process, was successfully employed to obtain lipid-based particulate systems with high (10–20% w/w) protein loading. Bovine serum albumin (BSA) was utilised as model protein and three low melting lipids (glyceryl palmitostearate, trimirystin and tristearin) were employed as carriers. BSA-loaded lipid microparticles were characterised in terms of particle size, morphology and drug loading. The results showed that the microparticles exhibited a spherical shape, mean diameter in the range 150–300 µm and an encapsulation efficiency higher than 90%. Possible changes in the protein structure as a result of the manufacturing process was then investigated for the first time using UV spectrophotometry in fourth derivative mode and FT-Raman spectroscopy. The results suggested that the structural integrity of the protein was maintained within the particles. Thermal analysis indicated that the effect of protein on the thermal properties of the carriers could be detected. Spray-congealing could thus be considered a suitable technique to produce highly BSA-loaded microparticles preserving the structure of the protein.

A deeper search for the progenitor of the Type Ic supernova 2002ap

Images of the site of the Type Ic supernova (SN) 2002ap taken before explosion were analysed previously by Smartt et al. We have uncovered new unpublished, archival pre-explosion images from the Canada-France-Hawaii Telescope (CFHT) that are vastly superior in depth and image quality. In this paper we present a further search for the progenitor star of this unusual Type Ic SN. Aligning high-resolution Hubble Space Telescope observations of the SN itself with the archival CFHT images allowed us to pinpoint the location of the progenitor site on the groundbased observations. We find that a source visible in the B- and R-band pre-explosion images close to the position of the SN is (1) not coincident with the SN position within the uncertainties of our relative astrometry and (2) is still visible similar to 4.7-yr post-explosion in late-time observations taken with the William Herschel Telescope. We therefore conclude that it is not the progenitor of SN 2002ap. We derived absolute limiting magnitudes for the progenitor of M-B >= -4.2 +/- 0.5 and M-R >= -5.1 +/- 0.5. These are the deepest limits yet placed on a Type Ic SN progenitor. We rule out all massive stars with initial masses greater than 7-8 M-circle dot (the lower mass limit for stars to undergo core collapse) that have not evolved to become Wolf-Rayet stars. This is consistent with the prediction that Type Ic SNe should result from the explosions of Wolf-Rayet stars. Comparing our luminosity limits with stellar models of single stars at appropriate metallicity (Z = 0.008) and with standard mass-loss rates, we find no model that produces a Wolf-Rayet star of low enough mass and luminosity to be classed as a viable progenitor. Models with twice the standard mass-loss rates provide possible single star progenitors but all are initially more massive than 30-40 M-circle dot. We conclude that any single star progenitor must have experienced at least twice the standard mass-loss rates, been initially more massive than 30-40 M-circle dot and exploded as a Wolf-Rayet star of final mass 10-12 M-circle dot. Alternatively a progenitor star of lower initial mass may have evolved in an interacting binary system. Mazzali et al. propose such a binary scenario for the progenitor of SN 2002ap in which a star of initial mass 15-20 M-circle dot is stripped by its binary companion, becoming a 5 M-circle dot Wolf-Rayet star prior to explosion. We constrain any possible binary companion to a main-sequence star of

Preparing for the future:Challenges and opportunities for management and leadership skills

The development of effective leaders is essential for all healthcare professions and increasingly is becoming a key focus for the UK dental profession. There is comparatively little research about dental leadership in a UK context and the paper below should begin to help to redress the balance and to highlight areas for future consideration.
The aim of the study was to explore dental leaders’ perceptions of the current position of leadership in the dental profession and used a qualitative key informant study to do this. Three broad emergent themes are described and discussed - characteristics and behaviours of dental leaders; challenges for dental leaders; education and training for dental leadership. The findings show that whilst recognising that a lack of focus on leadership skills has caused problems in the past, current dental leaders are prepared to lead the profession forward. They view education at all levels as vital to this process and education for leadership at undergraduate level is perceived as an important way forward.

Methylation using dimethylcarbonate catalysed by ionic liquids under continuous flow conditions

The ionic liquid, tributylmethylammonium methylcarbonate, has been employed as a catalytic base for clean N-methylation of indole with dimethylcarbonate. The reaction conditions were optimised under microwave heating to give 100% conversion and 100% selectivity to N-methylindole, and subsequently transferred to a high temperature/high pressure (285 degrees C/150 bar) continuous flow process using a short (3 min) residence time and 2 mol% of the catalyst to efficiently methylate a variety of different amines, phenols, thiophenols and carboxylic acid substrates. The extremely short residence times, versatility, and high selectivity have significant implications for the synthesis of a wide range of pharmaceutical intermediates, as high product throughputs can be obtained via this scalable continuous flow protocol. It has also been shown that the ionic liquid can be generated in situ from tributylamine, which has the net effect of transforming an ineffective stoichiometric base into a highly efficient catalyst for this broad class of reactions.

Secure Key Generation from OFDM Subcarriers’ Channel Response

The ability to exchange keys between users is vital in any wireless based security system. A key generation technique exploits the randomness of the wireless channel is a promising alternative to existing key distribution techniques, e.g., public key cryptography. In this paper a secure key generation scheme based on the subcarriers’ channel responses in orthogonal frequencydivision multiplexing (OFDM) systems is proposed. We first implement a time-variant multipath channel with its channel impulse response modelled as a wide sense stationary (WSS) uncorrelated scattering random process and demonstrate that each subcarrier’s channel response is also a WSS random process. We then define the X% coherence time as the time required to produce an X% correlation coefficient in the autocorrelation function (ACF) of each channel tap, and find that when all the channel taps have the same Doppler power spectrum, all subcarriers’ channel responses has the same ACF as the channel taps. The subcarrier’s channel response is then sampled every X% coherence time and quantized into key bits. All the key sequences’ randomness is tested using National Institute of Standards and Technology (NIST) statistical test suite and the results indicate that the commonly used sampling interval as 50% coherence time cannot guarantee the randomness of the key sequence.

Managing patient deterioration: evaluation of what works.

Background: Rapid Response Systems (RRS) have been implemented nationally and internationally to improve patient safety in hospital. However, to date the majority of the RRS research evidence has focused on measuring the effectiveness of the intervention on patient outcomes. To evaluate RRS it has been recommended that a multimodal approach is required to address the broad range of process and outcome measures required to determine the effectiveness of the RRS concept. Aim: The aim of this paper is to evaluate the official RRS programme theoretical assumptions regarding how the programme is meant to work against actual practice in order to determine what works. Methods: The research design was a multiple case study approach of four wards in two hospitals in Northern Ireland. It followed the principles of realist evaluation research which allowed empirical data to be gathered to test and refine RRS programme theory [1]. This approach used a variety of mixed methods to test the programme theories including individual and focus group interviews with a purposive sample of 75 nurses and doctors, observation of ward practices and documentary analysis. The findings from the case studies were analysed and compared within and across cases to identify what works for whom and in what circumstances. Results: The RRS programme theories were critically evaluated and compared with study findings to develop a mid-range theory to explain what works, for whom in what circumstances. The findings of what works suggests that clinical experience, established working relationships, flexible implementation of protocols, ongoing experiential learning, empowerment and pre-emptive management are key to the success of RRS implementation.  Conclusion:These findings highlight the combination of factors that can improve the implementation of RRS and in light of this evidence several recommendations are made to provide policymakers with guidance and direction for their success and sustainability.References: 1.Pawson R and Tilley N. (1997) Realistic Evaluation. Sage Publications; LondonType of submission: Concurrent session Source of funding: Sandra Ryan Fellowship funded by the School of Nursing & Midwifery, Queen’s University of Belfast

Engineering Simulations

Over recent years, ionic liquids have emerged as a class of novel fluids that have inspired the development of a number of new products and processes. The ability to design these materials with specific functionalities and properties means that they are highly relevant to the growing philosophy of chemical-product design. This is particularly appropriate in the context of a chemical industry that is becoming increasingly focussed on small-volume, high-value added products with relatively short times to market. To support such product and process development, a number of tools can be utilised. A key requirement is that the tool can predict the physical properties and activity coefficients of multi-component mixtures and, if required, model the process in which the materials will be used. Multi-scale simulations that span density functional theory (DFT) to process-engineering computations can address the relevant time and length scales and have increased in usage with the availability of cheap and powerful computers. Herein we will discuss the area of engineering calculations relating to the design of ionic liquid processes, that is, the computational tools that bridge this gap and allow for process simulation tools to utilise and assist in the design of ionic liquids. It will be shown that, at present, it is possible to use available tools to estimate many important properties of ionic liquids and mixtures containing them with a sufficient level of accuracy for preliminary design and selection.

Secure key generation from OFDM subcarriers' channel responses

The ability to exchange keys between users is vital in any wireless based security system. A key generation technique which exploits the randomness of the wireless channel is a promising alternative to existing key distribution techniques, e.g., public key cryptography. In this paper, a secure key generation scheme based on the subcarriers' channel responses in orthogonal frequency-division multiplexing (OFDM) systems is proposed. We first implement a time-variant multipath channel with its channel impulse response modelled as a wide sense stationary (WSS) uncorrelated scattering random process and demonstrate that each subcarrier's channel response is also a WSS random process. We then define the X% coherence time as the time required to produce an X% correlation coefficient in the autocorrelation function (ACF) of each channel tap, and find that when all the channel taps have the same Doppler power spectrum, all subcarriers' channel responses has the same ACF as the channel taps. The subcarrier's channel response is then sampled every X% coherence time and quantized into key bits. All the key sequences' randomness is tested using National Institute of Standards and Technology (NIST) statistical test suite and the results indicate that the commonly used sampling interval as 50% coherence time cannot guarantee the randomness of the key sequence.

A obra no gerúndio

Tese de doutoramento, Belas-Artes (Instalação), Universidade de Lisboa, Faculdade de Belas-Artes, 2014

O impacto da avaliação do desempenho docente na função docente e no desenvolvimento organizacional da escola

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Ciências da Educação - Especialidade Supervisão em Educação