Heterogeneity assumptions in the specification of bargaining models: a study of household level trade-offs between commuting time and salary

With many real world decisions being made in conjunction with other decision makers, or single agent decisions having an influence on other members of the decision maker's immediate entourage, there is strong interest in studying the relative weight assigned to different agents in such contexts. In the present paper, we focus on the case of one member of a two person household being asked to make choices affecting the travel time and salary of both members. We highlight the presence of significant heterogeneity across individuals not just in their underlying sensitivities, but also in the relative weight they assign to their partner, and show how this weight varies across attributes. This is in contrast to existing work which uses weights assigned to individual agents at the level of the overall utility rather than for individual attributes. We also show clear evidence of a risk of confounding between heterogeneity in marginal sensitivities and heterogeneity in the weights assigned to each member. We show how this can lead to misleading model results, and argue that this may also explain past results showing bargaining or weight parameters outside the usual [0,1] range in more traditional joint decision making contexts. In terms of substantive results, we find that male respondents place more weight on their partner's travel time, while female respondents place more weight on their partner's salary.

Evolving national park models: The emergence of an economic imperative and its effect on the contested nature of the 'national' park concept in Northern Ireland.

National park models have evolved in tandem with the emergence of a multifunctional countryside. Sustainable development has been added to the traditional twin aims of conservation and recreation. This is typified by recent national park designations, such as the Cairngorms National Park in Scotland. A proposed Mournes national park in Northern Ireland has evolved a stage further with a model of national park to deliver national economic goals envisaged by government. This seeks to commodify the natural landscape. This paper compares Cairngorm and Mourne stakeholders’ views on the principal features of both models: park aims, management structures and planning functions. While Cairngorm stakeholders were largely positive from the outset, the model of national park introduced is not without criticism. Conversely, Mourne stakeholders have adopted an anti-national park stance. Nevertheless, the model of national park proposed possessing a strong economic imperative, an absence of the Sandford Principle as a means to manage likely conflicts, and lacking any planning powers in its own right, may still be insufficient to bring about widespread support for a Mourne national park. Such a model is also likely to accelerate the degradation of the Mourne landscape. Competing national identities (British and Irish) provide an additional dimension to the national park debate in Northern Ireland. Deep ideological cleavages are capable of derailing the introduction of a national park irrespective of the model proposed. In Northern Ireland the national park debate is not only about reconciling environmental and economic interests but also political and ethno-national differences.

Improving the robustness of the iterative solver in state-space modelling of guitar distortion circuitry

Iterative solvers are required for the discrete-time simulation of nonlinear behaviour in analogue distortion circuits. Unfortunately,these methods are often computationally too expensive for realtime simulation. Two methods are presented which attempt to reduce the expense of iterative solvers. This is achieved by applying information that is derived from the specific form of the non linearity.The approach is first explained through the modelling of an asymmetrical diode clipper, and further exemplified by application to the Dallas Rangemaster Treble Booster guitar pedal, which provides an initial perspective of the performance on systems with multiple nonlinearities.

Distribution, occurrence and biotoxin composition of the main shellfish toxin producing microalgae within European waters: A comparison of methods of analysis

Harmful algal blooms (HABs) are a natural global phenomena emerging in severity and extent. Incidents have many economic, ecological and human health impacts. Monitoring and providing early warning of toxic HABs are critical for protecting public health. Current monitoring programmes include measuring the number of toxic phytoplankton cells in the water and biotoxin levels in shellfish tissue. As these efforts are demanding and labour intensive, methods which improve the efficiency are essential. This study compares the utilisation of a multitoxin surface plasmon resonance (multitoxin SPR) biosensor with enzyme-linked immunosorbent assay (ELISA) and analytical methods such as high performance liquid chromatography with fluorescence detection (HPLC-FLD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for toxic HAB monitoring efforts in Europe. Seawater samples (n = 256) from European waters, collected 2009-2011, were analysed for biotoxins: saxitoxin and analogues, okadaic acid and dinophysistoxins 1/2 (DTX1/DTX2) and domoic acid responsible for paralytic shellfish poisoning (PSP), diarrheic shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP), respectively. Biotoxins were detected mainly in samples from Spain and Ireland. France and Norway appeared to have the lowest number of toxic samples. Both the multitoxin SPR biosensor and the RNA microarray were more sensitive at detecting toxic HABs than standard light microscopy phytoplankton monitoring. Correlations between each of the detection methods were performed with the overall agreement, based on statistical 2 × 2 comparison tables, between each testing platform ranging between 32% and 74% for all three toxin families illustrating that one individual testing method may not be an ideal solution. An efficient early warning monitoring system for the detection of toxic HABs could therefore be achieved by combining both the multitoxin SPR biosensor and RNA microarray.

Web 2.0 no desenvolvimento profissional docente do ensino não superior: o caso da interactic 2.0

O surgimento da Web 2.0 imprimiu uma mudança na postura dos utilizadores da Web que passaram a poder não apenas ler e pesquisar, como também colaborar e produzir e publicar informação, adotando uma postura ativa. As redes sociais são uma poderosa ferramenta à qual recorrem movimentos sociais e políticos, o mundo da publicidade e do marketing, com evidentes efeitos nos indivíduos e na sociedade. Por seu lado, o desenvolvimento profissional de professores é um processo permanente, pelo que é reconhecida a importância da aprendizagem ao longo da vida em ambientes formais, não-formais e informais. Neste contexto, as redes sociais surgem como potenciais instrumentos de comunicação, interação, partilha e trabalho colaborativo, determinantes para o crescimento profissional dos docentes que almejam uma contínua aprendizagem. Este estudo de caso, que se centra na Interactic 2.0, uma rede social profissional essencialmente dirigida a educadores e criada numa aplicação Web 2.0 (Ning), teve como principal objetivo verificar em que medida esta rede social, ao possibilitar a formação e o desenvolvimento de uma comunidade de prática online, contribui para o desenvolvimento profissional dos docentes do ensino não superior. Os dados obtidos através da aplicação de inquéritos por questionário aos membros da Interactic 2.0, de entrevistas aos administradores da rede e da análise de interações num grupo específico da rede, revelam que os docentes do ensino não superior utilizam as ferramentas Web 2.0 para fins profissionais, nomeadamente as redes sociais, as aplicações de escritório online e os blogues. Conscientes dos riscos associados às redes sociais, mas também da necessidade de um constante enriquecimento profissional, os professores do ensino não superior reconhecem o interesse das redes sociais em geral, e da Interactic 2.0 em particular, como privilegiados instrumentos de partilha que contribuem para a sua atualização sobre aspetos curriculares e pedagógicos. Muito embora apenas concorram para o fomento do trabalho colaborativo entre professores, a Interactic 2.0 contribui para o aumento das competências digitais dos seus membros e para uma melhor integração das TIC em contexto educativo. A Interactic 2.0 é, portanto, uma comunidade de prática, constituída por um vasto número de pessoas com um interesse comum, que partilham e constroem conhecimento em torno de um domínio, criando um espaço partilhado de reflexão crítica sobre os temas em torno da educação.

Conceptual Analysis of Web 2.0 Technology Use to Enhance Parent–School Relationships

Parent–school relationships contribute significantly to the quality of students’ education. The Internet, in turn, has started to influence individuals’ way social communication and most school boards in Ontario now use the Internet to communicate with parents, which helps build parent–school relationships. This project comprised a conceptual analysis of how the Internet enhances parent–school relationships to support Ontario school board administrators seeking to implement such technology. The study’s literature review identified the links between Web 2.0 technology, parent–school relationships, and effective parent engagement. A conceptual framework of the features of Web 2.0 tools that promote social interaction was developed and used to analyze websites of three Ontario school boards. The analysis revealed that school board websites used static features such as email, newsletters, and announcements for communication and did not provide access to parents for providing feedback through Web 2.0 features such as instant messaging. General recommendations were made so that school board administrators have the opportunity to implement changes in their school community with feasible modifications. Overall, Web 2.0-based technologies such as interactive communication tools and social media hold the most promise for enhancing parent–school relationships because they can help not only overcome barriers of time and distance, but also improve the parents’ desire to be engaged in children’s education experiences.

Risque d’acquisition du virus de l’immunodéficience humaine (VIH) chez les femmes utilisant des hormones contraceptives orales et injectables

Objectif : Étudier l'association entre l’utilisation de contraceptifs hormonaux et le risque d'acquisition du VIH-1 chez les femmes au Malawi, en Afrique du Sud, en Zambie et au Zimbabwe. Devis : Analyses secondaires de 2887 femmes âgées de 17-55 ans ayant participé à l’étude HPTN 035, une étude de phase II/IIb sur l’efficacité de deux gels microbicides pour prévenir la transmission du VIH chez les femmes à risque. Méthodes : L'association entre l'utilisation de contraceptifs hormonaux et le risque d'acquisition du VIH-1 a été évaluée en utilisant des modèles de Cox. Des risques relatifs sont estimés où le groupe de référence est celui des femmes qui n’utilisent pas de contraceptifs hormonaux. De plus, un modèle multivarié de Cox est utilisé afin de contrôler pour les facteurs potentiellement confondants. Résultats : Les contraceptifs injectables ont été utilisés par 52,1% des femmes, alors que les contraceptifs oraux ont été utilisés par 20,7% de celles-ci. Pendant l'étude, il y a eu 192 séroconversions. L'incidence observée du VIH était de 2,28; 4,19 et 4,69 pour 100 personne-années pour les contraceptifs oraux, injectables et non hormonaux, respectivement. Lors de l’analyse multivariée, nous n'avons trouvé aucune association significative entre l’usage des contraceptifs hormonaux et l’acquisition du VIH-1. Le risque relatif ajusté (RRa) pour les contraceptifs oraux est de 0,573 (IC de 95% : [0,31-1,06]) et 0,981 (IC de 95% : [0,69 ; 1,39]) pour les contraceptifs injectables. Conclusions : Bien que cette étude ne démontre pas d’association entre l’usage des contraceptifs hormonaux et le VIH-1, nous concluons toutefois que ces méthodes de contraception ne protègent pas contre le VIH-1, et il est ainsi recommandé aux femmes utilisant des hormones contraceptives de toujours utiliser le condom pour prévenir l'infection au VIH-1.

Studies on bag models and properties of hadrons

This thesis is devoted to theoretical studies on the properties of hadrons on the basis of bag models. It contains some applications of the traditional.HIT bag model to the spectroscopy and decay of hadrons. The inadequacies of the model are brought out and a new version of the model, called the variable pressure bag model, is developed. Some of the Phenomenological applications of this model are discussed and the predictions are compared with experiment.

Metodologías de valoración de empresas

La valoración de una empresa como sistema dinámico es bastante compleja, los diferentes modelos o métodos de valoración son una aproximación teórica y por consiguiente simplificadora de la realidad. Dichos modelos, se aproximan mediante supuestos o premisas estadísticas que nos permiten hacer dicha simplificación, ejemplos de estos, son el comportamiento del inversionista o la eficiencia del mercado. Bajo el marco de un mercado emergente, este proceso presenta de indistinta forma retos paracualquier método de valoración, dado a que el mercado no obedece a los paradigmas tradicionales. Lo anterior hace referencia a que la valoración es aún más compleja, dado que los inversionistas se enfrentan a mayores riesgos y obstáculos. Así mismo, a medida que las economías se globalizan y el capital es más móvil, la valoración tomaráaún más importancia en el contexto citado. Este trabajo de gradopretende recopilar y analizar los diferentes métodos de valoración, además de identificar y aplicar aquellos que se reconocen como “buenas prácticas”. Este proceso se llevó a cabo para una de las empresas más importantes de Colombia, donde fundamentalmente se consideró el contexto de mercado emergente y específicamente el sector petrolero, como criterios para la aplicación del tradicional DCF y el práctico R&V.

Impact of social capital on flexible work organisation models : comparative study of european countries. 'El impacto del capital social en modelos flexibles de organización del trabajo: un estudio comparativo de países europeos'.

Resumen basado en el de la publicación

Sensitivity of feature-based analysis methods of storm tracks to the form of background field removal

For the tracking of extrema associated with weather systems to be applied to a broad range of fields it is necessary to remove a background field that represents the slowly varying, large spatial scales. The sensitivity of the tracking analysis to the form of background field removed is explored for the Northern Hemisphere winter storm tracks for three contrasting fields from an integration of the U. K. Met Office's (UKMO) Hadley Centre Climate Model (HadAM3). Several methods are explored for the removal of a background field from the simple subtraction of the climatology, to the more sophisticated removal of the planetary scales. Two temporal filters are also considered in the form of a 2-6-day Lanczos filter and a 20-day high-pass Fourier filter. The analysis indicates that the simple subtraction of the climatology tends to change the nature of the systems to the extent that there is a redistribution of the systems relative to the climatological background resulting in very similar statistical distributions for both positive and negative anomalies. The optimal planetary wave filter removes total wavenumbers less than or equal to a number in the range 5-7, resulting in distributions more easily related to particular types of weather system. For the temporal filters the 2-6-day bandpass filter is found to have a detrimental impact on the individual weather systems, resulting in the storm tracks having a weak waveguide type of behavior. The 20-day high-pass temporal filter is less aggressive than the 2-6-day filter and produces results falling between those of the climatological and 2-6-day filters.