Interdigitating organic bilayers direct the short interlayer spacing in hybrid organic–inorganic layered vanadium oxide nanostructures

Layered metal oxides provide a single-step route to sheathed superlattices of atomic layers of a variety of inorganic materials, where the interlayer spacing and overall layered structure forms the most critical feature in the nanomaterials’ growth and application in electronics, health, and energy storage. We use a combination of computer simulations and experiments to describe the atomic-scale structure, dynamics and energetics of alkanethiol-intercalated layered vanadium oxide-based nanostructures. Molecular dynamics (MD) simulations identify the unusual substrate-constrained packing of the alkanethiol surfactant chains along each V2O5 (010) face that combines with extensive interdigitation between chains on opposing faces to maximize three-dimensional packing in the interlayer regions. The findings are supported by high resolution electron microscopy analyses of synthesized alkanethiol-intercalated vanadium oxide nanostructures, and the preference for this new interdigitated model is clarified using a large set of MD simulations. This dependency stresses the importance of organic–inorganic interactions in layered material systems, the control of which is central to technological applications of flexible hybrid nanomaterials.

Formal Modeling and Analysis Techniques for High Level Petri Nets

Petri Nets are a formal, graphical and executable modeling technique for the specification and analysis of concurrent and distributed systems and have been widely applied in computer science and many other engineering disciplines. Low level Petri nets are simple and useful for modeling control flows but not powerful enough to define data and system functionality. High level Petri nets (HLPNs) have been developed to support data and functionality definitions, such as using complex structured data as tokens and algebraic expressions as transition formulas. Compared to low level Petri nets, HLPNs result in compact system models that are easier to be understood. Therefore, HLPNs are more useful in modeling complex systems. There are two issues in using HLPNs - modeling and analysis. Modeling concerns the abstracting and representing the systems under consideration using HLPNs, and analysis deals with effective ways study the behaviors and properties of the resulting HLPN models. In this dissertation, several modeling and analysis techniques for HLPNs are studied, which are integrated into a framework that is supported by a tool. For modeling, this framework integrates two formal languages: a type of HLPNs called Predicate Transition Net (PrT Net) is used to model a system's behavior and a first-order linear time temporal logic (FOLTL) to specify the system's properties. The main contribution of this dissertation with regard to modeling is to develop a software tool to support the formal modeling capabilities in this framework. For analysis, this framework combines three complementary techniques, simulation, explicit state model checking and bounded model checking (BMC). Simulation is a straightforward and speedy method, but only covers some execution paths in a HLPN model. Explicit state model checking covers all the execution paths but suffers from the state explosion problem. BMC is a tradeoff as it provides a certain level of coverage while more efficient than explicit state model checking. The main contribution of this dissertation with regard to analysis is adapting BMC to analyze HLPN models and integrating the three complementary analysis techniques in a software tool to support the formal analysis capabilities in this framework. The SAMTools developed for this framework in this dissertation integrates three tools: PIPE+ for HLPNs behavioral modeling and simulation, SAMAT for hierarchical structural modeling and property specification, and PIPE+Verifier for behavioral verification.

The impacts of telecommuting in Dublin

Telecommuting has been perceived as an effective means of reducing commuter related trips, travel time and emissions. Previously, the lack of access to broadband Internet connection and teleconferencing software from home has acted as a barrier to telecommuting regularly or at all. However, with advances in information and communication technology in recent years telecommuting is becoming a viable option for employers and employees to undertake. This paper examines the current trends of full day and part day telecommuting in the Greater Dublin Area (GDA), and attempts to ascertain the most influential drivers and constraints related to telecommuting. The research presented estimates of the environmental benefits from individuals that telecommute. Finally, this paper seeks to determine the magnitude of carbon emissions savings from individuals adopting telecommuting and provides a social cost of carbon saving value. The survey results presented suggest that approximately 44% of the population of the GDA telecommute at least once a month. The findings also indicate that needing contact with colleagues is the most influential constraint to telecommuting, while greater flexibility and avoiding travelling in peak periods are the most important drivers in the propensity to telecommute. Finally, this study shows that there are substantial carbon reductions and social cost of carbon savings. Thus illustrating how telecommuting can be a viable and sustainable policy in the GDA or in other similar sized regions.

Promover la inclusión de las familias a través del desarrollo de Proyectos de Trabajo. Un estudio de caso

Se presenta una investigación cualitativa centrada en un estudio de caso realizado en un aula de niños y niñas de 5 años. Se analiza la potencialidad de la metodología de Proyectos de Trabajo (en adelante, PT) para facilitar la inclusión de las familias en el proceso de enseñanzaaprendizaje de sus hijos e hijas. A través de tres entrevistas en profundidad a las familias y de la documentación pedagógica obtenemos información que, tras ser analizada, revela los siguientes hallazgos: (1) La metodología de PT utiliza como parte esencial del proceso de enseñanzaaprendizaje los conocimientos y la experiencia profesional de las familias; (2) Las familias asumen un papel de tutorización y acompañamiento en los procesos educativos de sus hijos e hijas que, de forma simultánea, se producen en la escuela y en sus casas. Ajustan sus intervenciones a las demandas y realizan una labor de mediación entre las capacidades infantiles y el nuevo material de aprendizaje; (3) La colaboración de las familias, presente desde el inicio hasta que concluye el PT, requiere un compromiso muy elevado, resultando ser un elemento imprescindible para el desarrollo de esta metodología; y (4) Las familias identifican como fortaleza de los PT la escucha al alumnado. Como limitaciones, el tiempo desmesurado que requiere, las diferencias que puede generar en el alumnado los diferentes niveles de implicación de sus respectivas familias y la discontinuidad de este método con otras formas más tradicionales de afrontar la enseñanza en etapas posteriores.

Evolution of the diatoms: major steps in their evolution and a review of the supporting molecular and morphological evidence.

Over the years, many reviews of different aspects of diatom biology, ecology and evolution have appeared. Since 1993 many molecular trees have been produced to infer diatom phylogeny. In 2004, Medlin & Kaczmarska revised the systematics of the diatoms based on more than 20 years of consistent recovery of two major clades of diatoms that did not correspond to a traditional concept of centrics and pennates and established three classes of diatoms: Clade 1 = Coscinodiscophyceae (radial centrics) and Clade 2 = Mediophyceae (polar centrics + radial Thalassiosirales) and Bacillariophyceae (pennates). However, under certain analytical conditions, an alternative view of diatom evolution, a grades of clades, has been recovered that suggests a gradual evolution from centric to pennate symmetry. These two schemes of diatom evolution are evaluated in terms of whether or not the criteria advocated by Medlin & Kaczmarska that should be met to recover monophyletic classes have been used. The monophyly of the three diatom classes can only be achieved if (1) a secondary structure of the small subunit (SSU) rRNA gene was used to construct the alignment and not an alignment based on primary structure and (2) multiple outgroups were used. These requirements have not been met in each study of diatom evolution; hence, the grade of clades, which is useful in reconstructing the sequence of evolution, is not useful for accepting the new classification of the diatoms. Evidence for how these two factors affect the recovery of the three monophyletic classes is reviewed here. The three classes have been defined by clear morphological differences primarily based on gametangia and auxospore ontogeny and envelope structure, the presence or absence of a structure (tube process or sternum) associated with the annulus and the location of the cribrum in those genera with loculate areolae. New evidence supporting the three clades is reviewed. Other features of the cell are examined to determine whether they can also be used to support the monophyly of the three classes.

Evolution of the diatoms: major steps in their evolution and a review of the supporting molecular and morphological evidence.

Over the years, many reviews of different aspects of diatom biology, ecology and evolution have appeared. Since 1993 many molecular trees have been produced to infer diatom phylogeny. In 2004, Medlin & Kaczmarska revised the systematics of the diatoms based on more than 20 years of consistent recovery of two major clades of diatoms that did not correspond to a traditional concept of centrics and pennates and established three classes of diatoms: Clade 1 = Coscinodiscophyceae (radial centrics) and Clade 2 = Mediophyceae (polar centrics + radial Thalassiosirales) and Bacillariophyceae (pennates). However, under certain analytical conditions, an alternative view of diatom evolution, a grades of clades, has been recovered that suggests a gradual evolution from centric to pennate symmetry. These two schemes of diatom evolution are evaluated in terms of whether or not the criteria advocated by Medlin & Kaczmarska that should be met to recover monophyletic classes have been used. The monophyly of the three diatom classes can only be achieved if (1) a secondary structure of the small subunit (SSU) rRNA gene was used to construct the alignment and not an alignment based on primary structure and (2) multiple outgroups were used. These requirements have not been met in each study of diatom evolution; hence, the grade of clades, which is useful in reconstructing the sequence of evolution, is not useful for accepting the new classification of the diatoms. Evidence for how these two factors affect the recovery of the three monophyletic classes is reviewed here. The three classes have been defined by clear morphological differences primarily based on gametangia and auxospore ontogeny and envelope structure, the presence or absence of a structure (tube process or sternum) associated with the annulus and the location of the cribrum in those genera with loculate areolae. New evidence supporting the three clades is reviewed. Other features of the cell are examined to determine whether they can also be used to support the monophyly of the three classes.

The VLT-FLAMES Tarantula Survey: XIX. B-type supergiants: Atmospheric parameters and nitrogen abundances to investigate the role of binarity and the width of the main sequence

Context: Model atmosphere analyses have been previously undertaken for both Galactic and extragalactic B-type supergiants. By contrast, little attention has been given to a comparison of the properties of single supergiants and those that are members of multiple systems. 

Aims: Atmospheric parameters and nitrogen abundances have been estimated for all the B-type supergiants identified in the VLT-FLAMES Tarantula survey. These include both single targets and binary candidates. The results have been analysed to investigate the role of binarity in the evolutionary history of supergiants. 

Methods: tlusty non-local thermodynamic equilibrium (LTE) model atmosphere calculations have been used to determine atmospheric parameters and nitrogen abundances for 34 single and 18 binary supergiants. Effective temperatures were deduced using the silicon balance technique, complemented by the helium ionisation in the hotter spectra. Surface gravities were estimated using Balmer line profiles and microturbulent velocities deduced using the silicon spectrum. Nitrogen abundances or upper limits were estimated from the Nii spectrum. The effects of a flux contribution from an unseen secondary were considered for the binary sample. Results. We present the first systematic study of the incidence of binarity for a sample of B-type supergiants across the theoretical terminal age main sequence (TAMS). To account for the distribution of effective temperatures of the B-type supergiants it may be necessary to extend the TAMS to lower temperatures. This is also consistent with the derived distribution of mass discrepancies, projected rotational velocities and nitrogen abundances, provided that stars cooler than this temperature are post-red supergiant objects. For all the supergiants in the Tarantula and in a previous FLAMES survey, the majority have small projected rotational velocities. The distribution peaks at about 50 km s^-1 with 65% in the range 30 km s^-1 ≤ ν_e sin i ≤ 60 km s^-1. About ten per cent have larger ve sin i (≥100 km s^-1), but surprisingly these show little or no nitrogen enhancement. All the cooler supergiants have low projected rotational velocities of ≤70 km s^-1 and high nitrogen abundance estimates, implying that either bi-stability braking or evolution on a blue loop may be important. Additionally, there is a lack of cooler binaries, possibly reflecting the small sample sizes. Single-star evolutionary models, which include rotation, can account for all of the nitrogen enhancement in both the single and binary samples. The detailed distribution of nitrogen abundances in the single and binary samples may be different, possibly reflecting differences in their evolutionary history. 

Conclusions: The first comparative study of single and binary B-type supergiants has revealed that the main sequence may be significantly wider than previously assumed, extending to T_eff = 20 000 K. Some marginal differences in single and binary atmospheric parameters and abundances have been identified, possibly implying non-standard evolution for some of the sample. This sample as a whole has implications for several aspects of our understanding of the evolutionary status of blue supergiants.

Comprometimento Organizacional, Autocriticismo e Autocompaixão na PSP

Introdução: São poucos os estudos que em Portugal se dedicaram a explorar constructos como o autocriticismo, autocompaixão, saúde mental e o comprometimento organizacional. São nossos objetivos analisar estas associações na Polícia de Segurança Pública, considerando igualmente a influência de variáveis sociodemográficas e profissionais, bem como realizar análises preditivas que permitam verificar quais são as variáveis preditores do comprometimento organizacional. Metodologia: A amostra é constituída por 188 polícias com idades compreendidas entre os 30 e 56 anos (M = 43,75, DP = 5,66). Os participantes preencheram um protocolo integrante do projeto Organizar Positivamente do Instituto Superior Miguel Torga, composto por um questionário sociodemográfico, a SELFCS (Escala da Autocompaixão), a FSCRS (Escala das Formas do Autocriticismo e Autotranquilização), o MHI-5 (Mental Health Inventory) e o QCO (Questionário do Comprometimento Organizacional). Resultados: Os polícias parecem regular a sua relação com a organização através do comprometimento calculativo. A autocompaixão associa-se positivamente ao comprometimento afetivo, sobressaindo a capacidade de mindfulness. O autocriticismo, na forma eu inadequado - menos corrosivo que a forma eu detestado -, revela uma relação positiva com o comprometimento calculativo, pelo que a permanência na organização pode ser emocionalmente negativa, originar ataques ao eu e diminuir a capacidade afetiva. Porém, a capacidade autotranquilizadora (forma eu tranquilizador do autocriticismo) parece capacitar os polícias para o desenvolvimento de maiores níveis de comprometimento organizacional e afetivo. A idade, a antiguidade e menos habilitações literárias parecem favorecer o comprometimento calculativo. Discussão: A autocompaixão pode contribuir para uma atitude positiva e afetuosa do polícia para com a organização. Assim, através de uma intervenção baseada na autocompaixão e no mindfulness, com impacto positivo no comportamento afetivo e normativo, não só se poderá preservar e promover a saúde e o bem-estar dos polícias, mas também fomentar o empenho organizacional, atenuando os efeitos negativos da profissão policial. Esta abordagem poderá contribuir para os objetivos organizacionais, através da supressão das emoções aversivas, da diminuição da intenção de turnover e abandono da organização. / Introduction: There are few studies in Portugal that have been dedicated to explore constructs such as self-criticism, self-compassion, mental health and organizational commitment. Our goals are to analyze these associations at the Public Safety Police, considering also the influence of sociodemographic and professionals variables, as well as to conduct predictive analyses, in order to verify which variables may predict organizational commitment. Methodology: The sample consisted of 188 police with ages between 30 and 56 years (M = 43.75, SD = 5.66). The participants filled in a protocol from the project Organizar Positivamente, from Instituto Superior Miguel Torga, composed by a sociodemographic questionnaire, the SELFCS (Self-Compassion Scale), the FSCRS (Scale of Forms of Self-Criticism and Self-Reassurance, the MHI-5 (Mental Health Inventory) and the QCO (Organizational Commitment Questionnaire). Results: The police officers appear to regulate their relationship with the organization through calculative commitment. Self-compassion is associated positively to affective commitment, with mindfulness showing to be the most important competence in this professional group. Self-criticism, in its inadequate self form – which is less corrosive than the hated self form - reveals a positive relationship with calculative commitment, which might imply that staying in the organization may be emotionally negative, may provoke attacks against the self and diminish the affective capacity. However, the self reassurance capacity (reassure self form of self-criticism) may enable the police officers to develop higher levels of organizational commitment and affective commitment, as well. Age, seniority and fewer qualifications seem to support the calculative commitment. Discussion: Through self-compassion police officers may experience a positive and warmth attitude towards the organization. Thus, an intervention program based on self-compassion and mindfulness may stimulate affective and normative commitment, not only preserving and promoting health and the well-being of police officers, but also fostering organizational commitment and mitigating negative effects in the police profession. This approach may contribute to organizational goals’ through the suppression of aversive emotions, decreasing turnover and intention to abandon the organization.

The Influence of Informational and Emotional Advertising Appeals on Advertising Effectiveness – Consumers’ Perspective on the Over-the-Counter Product Advertisements in Finland

Consumers face enormous amounts of promotional messages daily whereas the pharmaceutical companies among other industries spend considerable time and money developing effective advertising strategies. There are multiple possible ways to appeal the target customer in order to increase the effectiveness of the advertisement. In spite of the various possibilities to categorize persuasive communication, the informational and the emotional appeals are the typical approaches. This study assesses the influence of the informational and emotional advertising appeals on the advertising effectiveness in the context of OTCs in Finland. The research method applied in this study is a quantitative survey. The data consists of 461 responses from the target population of 18–80 years old Finnish speaking consumers. The results from the marketing research indicate that the positive correlations of the emotional appeals are much stronger than the positive correlations of the informational appeals relating to the advertising effectiveness. However, on average the Finnish consumers experience the OTC advertisements relying on the informational appeals more effective than the OTC advertisements relying on the emotional appeals. Furthermore, within emotional appeals there is a much greater variety in the experienced advertising effectiveness not providing as stabile and consistent experienced advertising effectiveness compared to the informational appeals. Thus, the OTC advertisement relying more on the emotional appeals are much more risky in terms of advertising effectiveness. There are also differences with the experienced advertising effectiveness between the Finnish consumer groups and the information can be utilised when designing tailored OTC advertisements. The Finnish men consider humorous advertisements more effective than the Finnish women. In addition, the people living outside Uusimaa Region experience higher advertising effectiveness with the advertisements relying more on the informational advertisements compared to the people living in Uusimaa Region. In similar vein, the people with lower education experience higher advertising effectiveness with the advertisements relying more on the informational advertisements compared to the people with high education. Additionally, the older generation perceive an OTC advertisement with a middle-aged celebrity more effective than the younger consumers

Development of a toolbox for the reduction of hordeins in barley malt beers

Gluten sensitive consumers and people suffering from coeliac disease account for up to 6% of the general population (Catassi et al., 2013). These consumers must avoid foods which contain gluten and related proteins found in wheat, rye or barley. Beer is produced from barley malt and therefore contains hordeins, (gluten like proteins). Beers labelled as gluten-free must contain below 10 mg/kg hordeins (10 mg/kg hordeins = 20 mg/kg gluten under current regulations) to be considered safe for gluten sensitive consumers. Currently there are a limited number of methods available for reducing beer hordeins, the studies outlined in this thesis provide a range of tools for the beverage industry to reduce the hordein content of beer It is well known, that during malting and brewing hordeins are reduced, but they still remain in beer at levels above 10 mg/kg. During malting, hordeins are broken down to form new proteins in the growing plant. Model malting and brewing systems were developed and used to test, how the modification of the malting process could be used to reduce beer hordeins. It was shown, that by using a controlled malting and brewing regime, a range of barley cultivars produced beer with significant differences in levels of hordeins. Beer hordeins ranged from 10 mg/kg to 60 mg/kg. Another study revealed that when malting was prolonged, to maximise breakdown of proteins, beer hordeins can be reduced by up to 44%. The natural breakdown of hordein during malting enhanced in a further study, when a protease was added to support the hordein degradation during steeping and germination. The enzyme addition resulted in a 46% reduction in beer hordeins 2 when compared to the control. All of the malt treatments had little or no impact on malt quality. The hordein levels can also be reduced during the beer stabilisation process. Levels of beer hordein were tested after stabilisation using two different concentrations of silica gel and tannic acid. Silica gel was very effective in reducing beer hordeins, 90% of beer hordeins were removed compared to the control beer. Beer hordeins could be reduced to below 10 mg/kg and the beer qualities such as foam, colour and flavour were not affected. Tannic acid also reduced beer hordein by up to 90%, but it reduced foam stability and affected beer flavours. A further study described treatment of beer with microbial transglutaminase (mTG), to create bonds between hordein proteins, which increased particle size and allowed removal during filtration. The addition of the mTG led to a reduction of the beer hordein by up to 96% in beer, and the impact on the resulting beer quality was minimal. These studies provide the industry with a toolbox of methods leading to the reduction of hordein in the final beer without negatively affecting beer quality.

Surveillance in Nineteen Eighty-Four : The Dismantling of Privacy in Oceania

The purpose of this essay is to analyze how certain elements of panopticism manage to dismantle the notion of privacy in George Orwell’s novel Nineteen Eighty-Four. By reading the text through a lens of panopticism, a theory introduced by Jeremy Bentham, I give examples on how the surveillance methods used by the Party share similarities with the system of surveillance within a Panoptic prison, but also in what ways that they differ. In the end, it is obvious that the society of Oceania cannot be considered to be a complete Panopticon, although several elements of panopticism are present within the text and that they dismantle the aspect of privacy in the novel. 

Metabolomics as a tool to explore the staphylococcal biofilm

Orthopaedic infections can be polymicrobial existing as a microbiome. Infections often incorporate staphylococcal species, including Staphylococcus aureus. Such infections can lead to life threatening illness and implant failure. Furthermore, biofilm formation on the implant surface can occur, increasing pathogenicity, exacerbating antibiotic resistance and altering antimicrobial mechanism of action. Bacteria change dramatically during the transition to a biofilm growth state: phenotypically; transcriptionally; and metabolically, highlighting the need for research into molecular mechanisms involved in biofilm formation. Metabolomics can provide a tool to analyse metabolic changes which are directly related to the expressed phenotype. Here, we aimed to provide greater understanding of orthopaedic infection caused by S. aureus and biofilm formation on the implant surface. Through metagenome analysis by employing: implant material extraction; DNA extraction; microbial enrichment; and whole genome sequencing, we present a microbiome study of the infected prosthesis to resolve the causative species of orthopaedic hip infection. Results highlight the presence of S. aureus as a primary cause of orthopaedic infection along with Enterococcus faecium and the presence of secondary pathogen Clostridium difficile. Although results were hindered by the presence of host contaminating DNA even after microbial enrichment, conclusions could be made over the potential increased pathogenicity caused by the presence of a secondary pathogen and highlight method and sample preparation considerations when undertaking such a study. Following this finding, studies were focused on an orthopaedic clinical isolate of S. aureus and a metabolome extraction method for staphylococcal biofilms was developed using cell lysis through bead beating and solvent metabolome extraction. The method was found to be reproducible when coupled with liquid chromatography-mass spectrometry (LC-MS) and bioinformatics, allowing for the detection of significant changes in metabolism between planktonic and biofilm cultures to be identified and drug mechanism of actions (MOA) to be studied. Metabolomics results highlight significant changes in a number of metabolic pathways including arginine biosynthesis and purine metabolism between the two cell populations, evidence of S. aureus responding to their changing environment, including oxygen availability and a decrease in pH. Focused investigations on purine metabolism looking for biofilm modulation effects were carried out. Modulation of the S. aureus biofilm phenotype was observed through the addition of exogenous metabolites. Inosine increased biofilm biomass while formycin B, an inosine analogue, showed a dispersal effect and a potential synergistic effect in biofilm dispersal when coupled with gentamycin. Changes in metabolism between planktonic cells and biofilms highlight the requirement for antimicrobial testing to be carried out against planktonic cells and biofilms. Untargeted metabolomics was used to study the MOA of triclosan in S. aureus. The triclosan target and MOA in bacteria has already been characterised, however, questions remain over its effects in bacteria. Although the use of triclosan has come under increasing speculation, its full effects are still largely unknown. Results show that triclosan can induce a cascade of detrimental events in the cell metabolism including significant changes in amino acid metabolism, affecting planktonic cells and biofilms. Results and conclusions provide greater understanding of orthopaedic infections and specifically focus on the S. aureus biofilm, confirming S. aureus as a primary cause of orthopaedic infection and using metabolomic analysis to look at the changing state of metabolism between the different growth states. Metabolomics is a valuable tool for biofilm and drug MOA studies, helping understand orthopaedic infection and implant failure, providing crucial insight into the biochemistry of bacteria for the potential for inferences to be gained, such as the MOA of antimicrobials and the identification of novel metabolic drug targets.

Studies of the gastro-oesophageal junction in normal and overweight healthy volunteers

Introduction: Oesophageal adenocarcinoma has increased dramatically in incidence over the past three decades with a particularly high burden of disease at the gastro-oesophageal junction. Many cases occur in individuals without known gastro-oesophageal reflux disease and in the absence of Barrett’s oesophagus suggesting that mechanisms other than traditional reflux may be important. Distal squamous mucosa may be prone to acid damage even in the absence of traditional reflux by the mechanism of distal opening of the lower oesophageal sphincter. This is splaying of the distal segment of lower oesophageal sphincter allowing acid ingress without traditional reflux. It has been suggested that the cardiac mucosa at the gastro-oesophageal junction, separating oesophageal squamous mucosa and acid secreting columnar mucosa of the stomach may be an abnormal mucosa arising as a consequence of acid damage. By this theory the cardiac mucosa is metaplastic and akin to ultra-short Barrett’s oesophagus. Obesity is a known risk factor for adenocarcinoma at the gastro-oesophageal junction and its rise has paralleled that of oesophageal cancer. Some of this excess risk undoubtedly operates through stress on the gastro-oesophageal junction and a predisposition to reflux. However we sought to explore the impact of obesity on the gastro-oesophageal junction in healthy volunteers without reflux and in particular to determine the characteristics of the cardiac mucosa and mechanisms of reflux in this group. Methods: 61 healthy volunteers with normal and increased waist circumference were recruited. 15 were found to have a hiatus hernia during the study protocol and were analysed separately. Volunteers had comprehensive pathological, physiological and anatomical assessments of the gastro-oesophageal junction including endoscopy with biopsies, MRI scanning before and after a standardised meal, prolonged recording of pH and manometry before and after a meal and screening by fluoroscopy to identify the squamo-columnar junction. In the course of the early manometric assessments a potential error associated with the manometry system recordings was identified. We therefore also sought to document and address this on the benchtop and in vivo. Key Findings: 1. In documenting the behaviour of the manoscan we described an immediate effect of temperature change on the pressure recorded by the sensors; ‘thermal effect’ and an ongoing drift of the recorded pressure with time; ‘baseline drift’. Thermal effect was well compensated within the standard operation of the system but baseline drift not addressed. Applying a linear correction to recorded data substantially reduced the error associated with baseline drift. 2. In asymptomatic healthy volunteers there was lengthening of the cardiac mucosa in association with central obesity and age. Furthermore, the cardiac mucosa in healthy volunteers demonstrated an almost identical immunophenotype to non-IM Barrett’s mucosa, which is considered to arise by metaplasia of oesophageal squamous mucosa. These findings support the hypothesis that the cardia is metaplastic in origin. 3. We have demonstrated a plausible mechanism of damage to distal squamous mucosa in association with obesity. In those with a large waist circumference we observed increased ingress of acid within but not across the lower oesophageal sphincter; ‘intrasphincteric reflux’ 4. The 15 healthy volunteers with a hiatus hernia were compared to 15 controls matched for age, gender and waist circumference. Those with a hiatus hernia had a longer cardiac mucosa and although they did not have excess traditional reflux they had excess distal acid exposure by short segment acid reflux and intrasphincteric acid reflux. Conclusions: These findings are likely to be relevant to adenocarcinoma of the gastro-oesophageal junction

Pre-colonial institutions and long-run development in Latin America

The present doctoral thesis studies the association between pre-colonial institutions and long-run development in Latin America. The thesis is organised as follows: Chapter 1 places the motivation of the thesis by underlying relevant contributions in the literature on long-run development. I then set out the main objective of the thesis, followed by a brief outline of it. In Chapter 2, I study the effects of pre-colonial institutions on present-day socioeconomic outcomes for Latin America. The main thesis of this chapter is that more advanced pre-colonial institutions relate to better socioeconomic outcomes today - principally, but not only, through their effects on the Amerindian population. I test such hypothesis with a dataset of 324 sub-national administrative units covering all mainland Latin American countries. The extensive range of controls covers factors such as climate, location, natural resources, colonial activities and pre-colonial characteristics - plus country fixed effects. Results strongly support the main thesis. In Chapter 3, I further analyse the association between pre-colonial institutions and present-day economic development in Latin America by using the historical ethnic homelands as my main unit of analysis. The main hypothesis is that ethnic homelands inhabited by more advanced ethnic groups -as measured by their levels of institutional complexity- relate to better economic development today. To track these long-run effects, I construct a new dataset by digitising historiographical maps allowing me to pinpoint the geospatial location of ethnic homelands as of the XVI century. As a result, 375 ethnic homelands are created. I then capture the levels of economic development at the ethnic homeland level by making use of alternative economic measures --satellite light density data. After controlling for country-specific characteristics and applying a large battery of geographical, locational, and historical factors, I found that the effects of pre-colonial institutions relate to a higher light density --as a proxy for economic activity- in ethnic homelands where more advanced ethnic groups lived. In Chapter 4, I explore a mechanism linking the persistence of pre-colonial institutions in Latin America over the long-run: Colonial and post-colonial strategies along with the ethnic political capacity worked in tandem allowing larger Amerindian groups to "support" the new political systems in ways that would benefit their respective ethnic groups as well as the population at large. This mechanism may have allowed the effects of pre-colonial institutions to influence socioeconomic development outcomes up to today. To shed lights on this mechanism, I combine the index of pre-colonial institutions prepared for the second chapter of the present thesis with individual-level survey data on people's attitudes. By controlling for key observable and unobservable country-specific characteristics, the main empirical results show that areas with a history of more advanced pre-colonial institutions increase the probability of individuals supporting present-day political institutions. Finally, in Chapter 5, I summarise the main findings of the thesis, and emphasise the key weaknesses of the study as well as potential avenues for future research.