Carbon supported CdSe nanocrystals

Insights to the mechanism of CdSe nanoparticle attachment to carbon nanotubes following the hot injection method are discussed. It was observed that the presence of water improves the nanotube coverage while Cl containing media are responsible for the shape transformation of the nanoparticles and further attachment to the carbon lattice. The experiments also show that the mechanism taking place involves the right balance of several factors, namely, low passivated nanoparticle surface, particles with well-defined crystallographic facets, and interaction with an organics-free sp2 carbon lattice. Furthermore, this procedure can be extended to cover graphene by quantum dots.Comment: 5 pages, 5 figure

Testing the Expert Based Weights Used in the UK’s Index of Multiple Deprivation (IMD) Against Three Preference-Based Methods

The paper has benefitted from helpful comments and suggestions from Koen Decancq, Rainer Schulz, and participants at the Weighting in Multidimensional Measures workshop at OPHI, Oxford, the Overseas Development Workshop at ODI, London, seminar participants at Universiteit Antwerpen, and conference participants at New Directions in Welfare III, Paris. Any errors or omissions, of course, remain the responsibility of the authors. The project was funded by the Department of the Communities and Local Government. The Chief Scientist Office of the Scottish Government Health and Social Care Directorates funds HERU. The views expressed in this paper are those of the authors only and not those of the funding bodies.Peer reviewedPostprin

Non-market valuation using stated preferences: applications in the water sector

This thesis is concerned with the application of stated preference methods to non-market valuation problems. It reviews the literature on the state of the art of the method, and applies the techniques to three applications in the water sector. In the first application, estimates are presented of the value to households in England and Wales of improvements to the quality of water in the natural environment. The need for value estimates arises from the European Community Water Framework Directive, which drives water policy across the European Union. Area based values were generated to maximise the potential for subsequent policy incorporation and value transfer. These were found to vary from £2,263 to £39,168 per km 2 depending on the population density around the location of the improvement, the ecological scope of that improvement, and the value elicitation method employed. The second application investigates the cost of drought water use restrictions to households and businesses in London. Estimates of willingness to pay for service quality increments often play an important role in the decisions of regulators and regulated companies in industries where consumers have little opportunity to exercise their preferences for service quality. The estimates presented in this chapter are particularly applicable to regulatory appraisals of water company investment expenditure and to planning applications for projects to improve the resilience of urban water supply systems. The final application examines the reliability of values measured before an economic downturn for application during the downturn via analysis of near identical surveys conducted before, and during, the 2008-2010 economic recession. The main result is that the economic downturn led to lower willingness to pay when elicited via 5 the payment card contingent valuation method, but had no effect on values elicited via a dichotomous choice (i.e. referendum-type) contingent valuation question. Potential explanations for this finding are explored in light of the literature on closed-ended versus open-ended elicitation method comparisons

A growing threat to the ozone layer from short-lived anthropogenic chlorocarbons

Large and effective reductions in emissions of long-lived ozone-depleting substance (ODS) are being achieved through the Montreal Protocol, the effectiveness of which can be seen in the declining atmospheric abundances of many ODSs. An important remaining uncertainty concerns the role of very short-lived substances (VSLSs) which, owing to their relatively short atmospheric lifetimes (less than 6 months), are not regulated under the Montreal Protocol. Recent studies have found an unexplained increase in the global tropospheric abundance of one VSLS, dichloromethane (CH2Cl2), which has increased by around 60 % over the past decade. Here we report dramatic enhancements of several chlorine-containing VSLSs (Cl-VSLSs), including CH2Cl2 and CH2ClCH2Cl (1,2-dichloroethane), observed in surface and upper-tropospheric air in East and South East Asia. Surface observations were, on occasion, an order of magnitude higher than previously reported in the marine boundary layer, whilst upper-tropospheric data were up to 3 times higher than expected. In addition, we provide further evidence of an atmospheric transport mechanism whereby substantial amounts of industrial pollution from East Asia, including these chlorinated VSLSs, can rapidly, and regularly, be transported to tropical regions of the western Pacific and subsequently uplifted to the tropical upper troposphere. This latter region is a major provider of air entering the stratosphere, and so this mechanism, in conjunction with increasing emissions of Cl-VSLSs from East Asia, could potentially slow the expected recovery of stratospheric ozone

A new synthesis for cyclic diguanylic acid and its analogues

Cyclic bis(3’-5’)diguanylic acid (c-di-GMP) has been the focus of many research endeavors for biologists in the last decade. Indeed, this cyclic dinucleotide has been identified as a novel secondary messenger recently.[8-11, 49] This new discovery caused increasing interest in the regulation system which involves c-di-GMP. This insight, recently led to widespread findings about c-di-GMP in other bacteria. The cyclic bis(3’-5’)-nucleotide has been shown to regulate the transition from motility to sessility in bacteria including Caulobacter crescentus[15], Escherichia coli and the pathogenic bacteria Pseudomonas aeroginosa and Salmonella typhimurium[7]. This cyclic dinucleotide also showed an influence on community behavior like biofilm formation in pathogenic bacteria including Pseudomonas fluorescens[16], Yersinia pestis[17] and Vibrio cholerae[18]. It is also involved in the inhibition of Staphylococcus aureus cell–cell interactions and biofilm formation, as well as in the reduction of the virulence of the biofilmforming strains of the same bacterium in a mouse model of mastitis infection.[19] These findings suggest that cyclic diguanylic acid might be useful in preventing biofilm formation on clinically relevant surfaces such as medical devices and potentially, in the control and treatment of human and animal infection.[17] The biological activity might be even wider since reports have pointed out that this compound may have anticancer activity.[18] Thus, c-di-GMP represents an excellent platform for drug design in medicinal chemistry and especially in the field of antibiotics where compounds with new modes of action are required. However, the mechanisms of c-di-GMP dependent signalling remain unknown, mainly because little data is available on c-di-GMP.[8,10] In order to study the biochemistry of this cyclic dinucleotide more in detail we have started this project dedicated to the synthesis of c-di-GMP and its analogues. We intended to develop a synthetic pathway which could afford an efficient, reliable, flexible and scalable route to synthesize c-di-GMP. At the beginning of this work, the only reported synthetic route for c-di-GMP was the van Boom et al.[22-23] method starting from guanosine and using the phosphotriester methodology. This method was the starting point of our own synthetic investigations, even so the published synthesis needed tedious purification steps and its length rendered it only moderately suitable for eventual scale-up purposes. In the course of this work, two more synthetic pathways were reported by Hayakawa et al.[29] and Jones et al.[30] claiming better yields, easier realization and shorter reaction sequences. We then decided to apply some of their improvements, by modifying the guanosine building block to make it less polar but still use the phosphotriester methodology towards an easier assembly of c-di-GMP. However, no previously described method afforded large quantities of c-di-GMP. After having explored the different existing synthetic routes, it quickly became obvious that we would have to design a new method to obtain this compound in sizeable amounts to satisfy the demands for the biological investigations. We have decided to adopt a brand new approach in which we start from ribose building blocks and synthesize a sugar-phosphate backbone, and to introduce the base at a late stage (Scheme A). Through this route we anticipate to completely solve the difficulties, generally caused by the 2’-OH protection, by using the 1’,2’-acetal protecting group. In order to show the flexibility of our new synthetic route, the synthesis of basemodified analogues of c-di-GMP was undertaken. The intend was to show that the synthesis is not specific for purine bases but can be applied to pyrimidine bases as well as non natural nucleobases, such as xanthine or theophylline for example. Finally, we applied the same strategy to the synthesis of internucleotide linkage modified analogues.gies

Testing the expert based weights used in the UK’s Index of Multiple Deprivation (IMD) against three preference-based methods

The Index of Multiple Deprivation (IMD), used widely in England, is an important tool for social need and inequality identification. It summarises deprivation across seven dimensions (income, employment, health, education, housing and services, environment, and crime) to measure an area’s multidimensional deprivation. The IMD aggregates the dimensions that are differentially weighted using expert judgement. In this paper, we test how close these weights are to society’s preferences about the relative importance of each dimension to overall deprivation. There is not agreement in the literature on how to do this. This paper, therefore, develops and compares three empirical methods for estimating preference-based weights. We find the weights are similar across the methods, and between our empirical methods and the current IMD, but our findings suggest a change to two of the weights

Valuing the health and wellbeing aspects of community empowerment in an urban regeneration context using economic evaluation techniques

Background and Rationale: Urban regeneration programmes are well placed to address social inequalities, and improve residents' quality of life and thus, are increasingly regarded a form of population health intervention. Within such programmes, the central role of communities is becoming increasingly recognised as important, with policy makers highlighting the need for activities that foster community empowerment and community involvement in programmes’ delivery. A motivating factor for this emphasis on community empowerment is the envisaged health gains it can produce. Existing literature has demonstrated that community empowerment is linked to positive health (specifically mental health) however, little is known about this link within an urban regeneration context and the value of allocating resources to foster community empowerment as an outcome of urban regeneration programmes. Previous attempts to value community empowerment as an outcome of urban regenerations have failed to fully capture and measure this complex, multi-faceted outcome or its theorised links to health. This thesis crosses disciplines, addressing issues of public health, urban planning and health economics. However, as outlined in Chapter 1, its leading discipline is health economics, drawing on methodology from the field to make a contribution to the evolving focus of public health economic evaluation. Specifically, the thesis demonstrates how health economic methodology can be adapted or expanded upon to aid the challenges researchers face when trying to identify, measure and value complex, non-health outcomes (such as community empowerment) for inclusion in economic evaluations of population health interventions (such as urban regeneration), which, as discussed at length in Chapter 5, present numerous challenges for techniques previously used solely within the health sector, and commonly in controlled settings (randomised controlled trials). Methods: The thesis initially outlines the policy context of the study (community empowerment in urban regeneration), defines what is meant by community empowerment and the study’s overall health economics focus in Chapter 1. Chapter 2 continues this introduction to the study’s context by highlighting how community empowerment relates to other concepts, whether it is viewed as an outcome or a process and how this impacts on efforts of measuring the concept and through a rapid scoping review, summarises what is known in the current evidence base on community empowerment and its links to health. It clearly highlights that community empowerment is a context specific concept and that in order to identify, measure and value it within an urban regeneration context, investigation of its specific, quantifiable ‘elements’ within this context must be identified. This is presented in Chapters 3 and 4. Firstly, a systematic review with narrative synthesis was then conducted (Chapter 3) to identify whether urban regeneration interventions can lead to a sense of empowerment and key community empowerment elements within this context. Then in Chapter 4, analyses of cross-sectional data from Glasgow’s GoWell neighbourhoods regeneration study (n=4254) was used to further test the causal relationship between community empowerment and self-reported health. The final part of the thesis (Chapters 5-8), firmly centres these initial findings into the health economics focus of the thesis to demonstrate how discrete choice experiments could be used to value a non-health outcome such as community empowerment for future inclusion in economic evaluations of population health interventions. It outlines the challenges of conducting economic evaluations of population health interventions and the importance of health economics as a discipline for decision-makers (Chapter 5). Then in Chapters 6-8 it presents the conceptualisation, design and results of a UK representative population discrete choice experiment survey (n=311) and how its results can value community empowerment as a potential outcome (using the payment vehicle ‘time’) for use in economic evaluation of population health interventions within urban regeneration. Results: The thesis identifies that community empowerment can result from urban regeneration interventions and that there are specific community empowerment ‘elements’ within this context which can be used to start conceptualising how to measure and value this concept and its links to health. The thesis also demonstrated that this was not always a positive relationship between urban regeneration and community empowerment and that a sense of disempowerment could be felt by the affected communities. These elements were sense of inclusion, sense of belonging, residents’ time commitment, a sense of trust in stakeholders, availability of stakeholder help and support and, availability of information about the regeneration programme (Chapters 2-3). Regression analysis of the GoWell data (Chapter 4) highlighted significant associations between community empowerment and improved general health and mental wellbeing. The discrete choice experiment’s (shown in Chapters 6-8) mixed logit model analyses demonstrated that there is an overall value for community empowerment activities within urban regeneration. The general populations respondents strongest preferences were shown for the delivery of community empowerment activities which require less time commitment, offer opportunities to participate, fully explain decision making processes, increase social interactions with their neighbours, have help and support from stakeholders and, keep them informed of the regeneration programme. Respondents’ strongest preferences were for delivery of community empowerment attributes that increase sense of belonging and feeling informed about the regeneration programme. Conclusions: The thesis provides valuations for attributes of community empowerment which can be used to inform future resource allocation decisions related to the cost-effectiveness of community empowerment generating activities as part of the delivery of urban regeneration programmes. Progress on the application of economic evaluation methodology to public health has been challenging, thwarted by complexities due to broad ranging costs and outcomes that are not readily suited to established economic evaluation techniques. The thesis contributes to the growing field of public health economic evaluation by highlighting the use of stated preference techniques, specifically discrete choice experiment methodology as a tool for measuring and eliciting values for the non-health outcomes of population health interventions for inclusion in economic evaluations. Failure to capture and include all benefits or costs of these multi-sector interventions which seek to look beyond health gains could lead to under or over estimation of their value and total effectiveness. This could ultimately result in poor investment decisions. To conclude, this study has contributed to current evidence by providing a means for identifying, measuring and valuing community empowerment both as an outcome in its own right and as an interim surrogate outcome linked to health. Thus, it has begun to address and tackle the research gaps identified in previous studies (outlined in Section 1.2.2). It has valued individual elements of CE within urban regeneration programmes which can be used by policy makers for decisions regarding future investment in CE and has further evidenced claims that community empowerment is linked to health within this context. Therefore, the thesis is able to recommend investment for community empowerment promoting activities in the delivery of urban regeneration programmes as a pathway to mental health gains

Investigating dentists’ decision making and patients’ preferences in the prevention of dental caries

Aim: The aim of this study was to examine the decision making of dentists and patients in the prevention of dental caries in the UK and ROI. Contribution: This was the first study to investigate such a theme using a DCE approach. A framework analysis was applied with qualitative data to develop two DCE surveys. Policy suggestions for increasing prevention were also offered from dentist, patient and dentist patient relationship perspectives. Methods: A mix of qualitative methods were used in an iterative process to develop separate DCE surveys for dentists and patients. Finally, 143 dentists were recruited through snowball sampling and 353 members of the general public were recruited through an online panels company and Facebook. Mixed logit models were used to measure preferences from their survey responses. Latent class models were applied to explore preference heterogeneity. Results: The main model in the dentists’ study highlighted the following points. 1. Dentists placed great importance on preventive advice for patients with an adverse dental condition. 2. They disliked providing restorative treatment to a patient with a mild caries condition. 3. They felt obliged not only to treat the lesion by intervention but also to offer a toolkit of advice which would be helpful to the patient to prevent future caries. 4. They chose treatment plans containing the least possible intervention in cases of mild caries condition, preferring to deliver more preventive advice instead of preventive and restorative care. 5. They had stronger preferences for delivering preventive advice to younger patients. Latent class modelling showed that female, part-time dentists, those with more years since graduation, individuals working in small, public or mixed private-public practices, those more frequently delivering preventive care, and dentists seeing a higher share of patients exempted from payment had a higher tendency towards preventive care. The main model in the patients’ study underlined the following points. 1. Patients placed great importance on preventive treatment. 2. They preferred oral hygiene advice over dietary advice. 3. They preferred to see the dentist as opposed to a different dental professional and to avoid longer travel and waiting times. Latent class modelling demonstrated that older, unemployed, female patients, those with higher dental attendance, no private insurance, better education and with a less healthy oral profile were more likely to prefer preventive care. Discussion: The use of a mix of qualitative methods assisted in the development of the two DCE surveys. Dentists preferred to deliver restorative care as well as preventive treatment and advice for patients with an adverse dental condition. They tended to offer more preventive advice but less restorative and preventive care for patients with a mild caries condition. Patients preferred preventive treatment and oral hygiene advice while they were less inclined towards dietary advice. The welfare of patients was not worsened off to a great extent by whether a dentist or a different dental professional including a dental hygienist, therapist or nurse deliver preventive care. Checking for preference heterogeneity in both groups revealed that certain sociodemographic characteristics of dentists and patients were associated with a more prevention oriented behaviour. Recommendations: DCEs using patient vignettes were successfully used to measure preferences of dental professionals in the delivery of care. DCEs were also a feasible way to evaluate the preferences of patients towards the prevention of dental caries in a way which had not been previously reported. A framework analysis of data collected in the qualitative phase of a DCE study is proposed to deal with problems in a targeted manner and improve understanding of the DCE survey. Specific guidelines could be designed prioritising the need of preventive treatment for all groups of patients. Policies should target at remunerating dentists more properly for preventive treatment so that they could be motivated to offer more prevention. Implications of results: Preventive treatment could be assigned to a different dental professional including a dental hygienist, therapist or nurse without worsening off to a great extent the welfare of patients. Dentists could be trained to provide more information on the benefits of dietary advice as patients were less likely to prefer such advice. Focus of educational initiatives to enhance prevention should be placed on certain segments of the population instead of entire populations to permit a more efficient use of resources in preventive care

Duas abordagens de acesso a objetos em ambientes distribuidos

Orientador: Edmundo Roberto Mauro MadeiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da ComputaçãoResumo: O propósito dessa dissertação é a apresentação e a análise de formas de acesso a objetos em ambientes distribuídos com o objetivo de otimizar e facilitar ao cliente o acesso a serviços disponíveis em sistemas distribuídos. Para o desenvolvimento de nosso trabalho consideramos as especificações referentes ao processamento distribuído aberto (ODP - Open Distributed Processing), modelos de interfaces para programas de aplicação(APls - Application Program Interface) e plataformas comerciais de serviços distribuídos. A primeira forma propõe especificar uma interface para programas de aplicação, baseada na metodologia orientada a objetos, oferecendo um conjunto de serviços distribuídos fornecidos por plataformas comerciais existentes, para o desenvolvimento, manutenção e execução de aplicações. A segunda forma é baseada na arquitetura CORBA (Common Object Request Broker Architecture), no qual especificamos um esquema de acesso aos objetos desta arquitetura. Este esquema é baseado em repositórios de interfaces e implementações. Este esquema possibilita que as informações referentes a estes repositórios sejam obtidas de forma mais rápida e segura. Com isso espera-se que a CORBA proporcione melhores condições à camada Middleware de prover facilidades no processamento distribuído para as aplicações, em especial para as aplicações da plataforma Multiware que está sendo desenvolvida na UNICAMPAbstract: The purpose of this dissertation is to present and to analyse ways to access objects in distributed environments, as a means to optimize and to facilitate to the client the access to the distributed system services. The specifications of the open distributed processing (ODP - Open Distributed Processing), the models of the application program interfaces (APIs - Application Program Interface) and commercial distributed plataforms were considered for the development of this work. The first proposed specifies an application program interface, using an oriented-object methodology, to offer a group of services supplied by the existent commercial distributed plataforms to the development, running and management of distributed applications. The second proposed is based on the CORBA (Common Object Request Broker Architecture) architecture, where we specified an access scheme to the objects of this environment. This scheme is based on implementation and interface repositories. This scheme provides that the repository information is got quickly and safely. Then the Middleware layer provides distributed processing facilities to the applications, specially to the applications of the Multiware plataform, that is being developed at UNICAMPMestradoMestre em Ciência da Computaçã

Atmospheric Halocarbon Measurements with a focus on East and South-East Asia

A large variety of halocarbon species are present in the atmosphere and can significantly impact stratospheric ozone depletion and/or global warming. Compound use has been phased out, reduced and replaced for some species under global control measures such as the Montreal and Kyoto Protocols. However, relatively long atmospheric lifetimes, imperfect substitutes and incomplete reductions in usage mean that global abundances of halocarbon species still require regular monitoring. This is especially true for the rapidly developing East and South-East Asian regions where widespread emissions have been repeatedly reported in recent years. To detect a variety of halocarbon mixing ratios, air samples are cryotrapped and analysed via gas chromatography couple with mass spectrometry (GC-MS). Highly sensitive and precise instrumentation widens this range further and the automation of the analysis system would improve and extend sample throughput. A semi-automated inlet system for a GC-MS set-up was constructed and cryotrapping with liquid nitrogen was tested successfully. In the atmosphere, anthropogenic emissions are the main source of many halocarbons, however methyl halides also have large natural sources including from cultivated crops like rice. Using genetically mapped and altered Arabidopsis thaliana and Physcomitrella patens, methyl halide emission rates were calculated. Differences found when compared to wild type plants indicated the potential for developing ‘ozone-safe’ crops through manipulation of the HOL-gene, which may particularly benefit Asian emissions. Three short-term sampling campaigns based in Taiwan assessed abundances of mainly anthropogenically-sourced halocarbons in East Asia. Backwards trajectory modelling was used to estimate potential source regions and both enhanced and close to background mixing ratios were observed for a range of species. Pollution events and interspecies correlations were found for many halocarbons with poorly understood sources such as CFC-113a and HCFC-133a. A further short-term campaign based in Bachok, Malaysia assessed long-range transport of ozone-depleting species to South-East Asia during the cold surge phenomenon of the winter monsoon, when rapid vertical transport may occur. Short-lived species were observed at significantly high abundances suggesting their potential impact on stratospheric ozone may have been previously underestimated