Group strategy-proof social choice functions with binary ranges and arbitrary domains: characterization results

We define different concepts of group strategy-proofness for social choice functions. We discuss the connections between the defined concepts under different assumptions on their domains of definition. We characterize the social choice functions that satisfy each one of them and whose ranges consist of two alternatives, in terms of two types of basic properties.

Patients' preferences on information and involvement in decision-making for gastrointestinal surgery

Objective: The relationship between physicians and patients has undergone¦important changes, and the current emancipation of patients has led to¦a real partnership in medical decision-making. This study aimed to assess¦patients' preferences on different aspects of decision-making during treatment¦and potential complications, as well as the amount and type of preoperative¦information before visceral surgery.¦Methods: Prospective non-randomized study based on a questionnaire given¦to 253 consecutive patients scheduled for elective GI surgery.¦Results: Concerning surgical complications or treatment in the intensive care¦unit, 64% of patients wished to take actively part in any medical decisions.¦The respective figures for cardiac resuscitation and treatment limitations were¦89% and 60%. About information, 73%, 77% and 47% of patients wish¦detailed information, information on a potential ICUhospitalization and cardiac¦resuscitation, respectively. Elderly and low-educated patients were significantly¦less interested in shared medical decision-making (p = 0·003 and 0·015) and in¦information receiving (p = 0·03 and 0·05). Similarly, involvement of the family¦in decision-making was significantly less important in elderly and male patients¦(p = 0·05 and 0·03 respectively). Neither the type of operation (minor or major)¦nor the severity of disease (malignancies vs. non-malignancies) was a significant¦factor for shared decision-making, information or family involvement.¦Conclusion: The vast majority of surgical patients clearly want to get adequate¦preoperative information about their disease and the planned treatment. They¦also consider it as crucial to be involved in any kind of decision-making for¦treatment and complications. The family's role is limited to support the treating¦physicians if the patient is unable to participate in taking decisions.

Cross-talk between glutamate and potassium regulation at the astrocyte membrane

Astrocytes play a central role in the brain by regulating glutamate and extracellular potassium concentrations ([K+]0), both released by neurons into the extracellular space during neuronal activity. Glutamate uptake is driven by the inwardly directed sodium gradient across the astrocyte membrane and involves the influx of three sodium ions and one proton and the efflux of one K+ ion per glutamate molecule. The glutamate transport induced rise in intracellular sodium stimulates the Na+/K+-ATPase which leads to significant energetic costs in astrocytes. To evaluate how these two fundamental functions of astrocytes, namely glutamate transport and K+ buffering, which are directly associated with neuronal activity, coexist and if they influence each other, in this thesis work we examined different cellular parameters of astrocytes. We therefore investigated the impact of altered [K+]0 on glutamate transporter activity. To assess this question we measured intracellular sodium fluctuations in mouse primary cultured astrocytes using dynamic fluorescence imaging. We found that glutamate uptake was tightly modulated both in amplitude and kinetics by [K+]0. Elevated [K+]0 strongly decreased glutamate transporter activity, with significant consequences on the cells energy metabolism. To ultimately evaluate potential effects of [K+]0 and glutamate on the astrocyte mitochondrial energy production we extended these studies by investigating their impact on the cytosolic and mitochondrial pH. We found that both [K+],, and glutamate strongly influenced cytosolic and mitochondrial pH, but in opposite directions. The effect of a simultaneous application of K+ and glutamate, however, did not fit with the arithmetical sum of each individual effects, suggesting that an additional non¬linear process is involved. We also investigated the impact of [K+]0 and glutamate transport, respectively, on intracellular potassium concentrations ([K+]0 in cultured astrocytes by characterizing and applying a newly developed Insensitive fluorescent dye. We observed that [K+]i followed [K+]0 changes in a nearly proportional way and that glutamate superfusion caused a reversible, glutamate-concentration dependent drop of [K+],, Our study shows the powerful influence of [K+]u on glutamate capture. These findings have strong implications for our understanding of the tightly regulated interplay between astrocytes and neurons in situations where [K+]0 undergoes large activity-dependent fluctuations. However, depending on the extent of K+ versus glutamate extracellular rise, energy metabolism in astrocytes will be differently regulated. Moreover, the novel insights obtained during this thesis work help understanding some of the underlying processes that prevail in certain pathologies of central nervous system, such as epilepsy and stroke. These results will possibly provide a basis for the development of novel therapeutic strategies. -- Les astrocytes jouent un rôle central dans le cerveau en régulant les concentrations de potassium (K+) et de glutamate, qui sont relâchés par les neurones dans l'espace extracellulaire lorsque ceux- ci sont actifs. La capture par les astrocytes du glutamate est un processus secondairement actif qui implique l'influx d'ions sodium (Na+) et d'un proton, ainsi que l'efflux d'ions K+, ce processus entraîne un coût métabolique important. Nous avons évalué comment ces fonctions fondamentales des astrocytes, la régulation du glutamate et du K+ extracellulaire, qui sont directement associés à l'activité neuronale, coexistent et si elles interagissent, en examinant différents paramètres cellulaires. Dans ce projet de thèse nous avons évalué l'impact des modifications de la concentration de potassium extracellulaire ([K+],,) sur le transport du glutamate. Nous avons mesuré le transport du glutamate par le biais des fluctuations internes de Na+ grâce à un colorant fluorescent en utilisant de l'imagerie à fluorescence dynamique sur des cultures primaires d'astrocytes. Nous avons trouvé que la capture du glutamate était étroitement régulée par [K+]0 aussi bien dans son amplitude que dans sa cinétique. Par la suite, nous avons porté notre attention sur l'impact de [K+]0 et du glutamate sur le pH cytosolique et mitochondrial de l'astrocyte dans le but, in fine, d'évaluer les effets potentiels sur la production d'énergie par la mitochondrie. Nous avons trouvé qu'autant le K+ que le glutamate, de manière individuelle, influençaient fortement le pH, cependant dans des directions opposées. Leurs effets individuels, ne peuvent toutefois pas être additionnés ce qui suggère qu'un processus additionnel non-linéaire est impliqué. En appliquant une nouvelle approche pour suivre et quantifier la concentration intracellulaire de potassium ([K+]0 par imagerie à fluorescence, nous avons observé que [K+]i suivait les changements de [K+]0 de manière quasiment proportionnelle et que la superfusion de glutamate induisait un décroissement rapide et réversible de [K+]i, qui dépend de la concentration de glutamate. Notre étude démontre l'influence de [K+]0 sur la capture du glutamate. Ces résultats permettent d'améliorer notre compréhension de l'interaction entre astrocytes et neurones dans des situations où [K+]0 fluctue en fonction de l'activité neuronale. Cependant, en fonction de l'importance de l'augmentation extracellulaire du K+ versus le glutamate, le métabolisme énergétique des astrocytes va être régulé de manière différente. De plus, les informations nouvelles que nous avons obtenues durant ce travail de thèse nous aident à comprendre quelques- uns des processus sous-jacents qui prévalent dans certaines pathologies du système nerveux central, comme par exemple l'épilepsie ou l'accident vasculaire cérébral. Ces informations pourront être importantes à intégrer dans la cadre du développement de nouvelles stratégies thérapeutiques.

The de facto independence of regulatory agencies and its consequences for policy making and regulatory outcomes

This dissertation focuses on the practice of regulatory governance, throughout the study of the functioning of formally independent regulatory agencies (IRAs), with special attention to their de facto independence. The research goals are grounded on a "neo-positivist" (or "reconstructed positivist") position (Hawkesworth 1992; Radaelli 2000b; Sabatier 2000). This perspective starts from the ontological assumption that even if subjective perceptions are constitutive elements of political phenomena, a real world exists beyond any social construction and can, however imperfectly, become the object of scientific inquiry. Epistemologically, it follows that hypothetical-deductive theories with explanatory aims can be tested by employing a proper methodology and set of analytical techniques. It is thus possible to make scientific inferences and general conclusions to a certain extent, according to a Bayesian conception of knowledge, in order to update the prior scientific beliefs in the truth of the related hypotheses (Howson 1998), while acknowledging the fact that the conditions of truth are at least partially subjective and historically determined (Foucault 1988; Kuhn 1970). At the same time, a sceptical position is adopted towards the supposed disjunction between facts and values and the possibility of discovering abstract universal laws in social science. It has been observed that the current version of capitalism corresponds to the golden age of regulation, and that since the 1980s no government activity in OECD countries has grown faster than regulatory functions (Jacobs 1999). Following an apparent paradox, the ongoing dynamics of liberalisation, privatisation, decartelisation, internationalisation, and regional integration hardly led to the crumbling of the state, but instead promoted a wave of regulatory growth in the face of new risks and new opportunities (Vogel 1996). Accordingly, a new order of regulatory capitalism is rising, implying a new division of labour between state and society and entailing the expansion and intensification of regulation (Levi-Faur 2005). The previous order, relying on public ownership and public intervention and/or on sectoral self-regulation by private actors, is being replaced by a more formalised, expert-based, open, and independently regulated model of governance. Independent regulation agencies (IRAs), that is, formally independent administrative agencies with regulatory powers that benefit from public authority delegated from political decision makers, represent the main institutional feature of regulatory governance (Gilardi 2008). IRAs constitute a relatively new technology of regulation in western Europe, at least for certain domains, but they are increasingly widespread across countries and sectors. For instance, independent regulators have been set up for regulating very diverse issues, such as general competition, banking and finance, telecommunications, civil aviation, railway services, food safety, the pharmaceutical industry, electricity, environmental protection, and personal data privacy. Two attributes of IRAs deserve a special mention. On the one hand, they are formally separated from democratic institutions and elected politicians, thus raising normative and empirical concerns about their accountability and legitimacy. On the other hand, some hard questions about their role as political actors are still unaddressed, though, together with regulatory competencies, IRAs often accumulate executive, (quasi-)legislative, and adjudicatory functions, as well as about their performance.

Divergent functions of three Candida albicans zinc-cluster transcription factors (CTA4, ASG1 and CTF1) complementing pleiotropic drug resistance in Saccharomyces cerevisiae.

One of the mediators of pleiotropic drug resistance in Saccharomyces cerevisiae is the ABC-transporter gene PDR5. This gene is regulated by at least two transcription factors with Zn(2)-Cys(6) finger DNA-binding motifs, Pdr1p and Pdr3p. In this work, we searched for functional homologues of these transcription factors in Candida albicans. A C. albicans gene library was screened in a S. cerevisiae mutant lacking PDR1 and PDR3 and clones resistant to azole antifungals were isolated. From these clones, three genes responsible for azole resistance were identified. These genes (CTA4, ASG1 and CTF1) encode proteins with Zn(2)-Cys(6)-type zinc finger motifs in their N-terminal domains. The C. albicans genes expressed in S. cerevisiae could activate the transcription of a PDR5-lacZ reporter system and this reporter activity was PDRE-dependent. They could also confer resistance to azoles in a S. cerevisiae strain lacking PDR1, PDR3 and PDR5, suggesting that CTA4-, ASG1- and CTF1-dependent azole resistance can be caused by genes other than PDR5 in S. cerevisiae. Deletion of CTA4, ASG1 and CTF1 in C. albicans had no effect on fluconazole susceptibility and did not alter the expression of the ABC-transporter genes CDR1 and CDR2 or the major facilitator gene MDR1, which encode multidrug transporters known as mediators of azole resistance in C. albicans. However, additional phenotypic screening tests on the C. albicans mutants revealed that the presence of ASG1 was necessary to sustain growth on non-fermentative carbon sources (sodium acetate, acetic acid, ethanol). In conclusion, C. albicans possesses functional homologues of the S. cerevisiae Pdr1p and Pdr3p transcription factors; however, their properties in C. albicans have been rewired to other functions.

Evolution of decision-making and learning under fluctuating social environments

The capacity to learn to associate sensory perceptions with appropriate motor actions underlies the success of many animal species, from insects to humans. The evolutionary significance of learning has long been a subject of interest for evolutionary biologists who emphasize the bene¬fit yielded by learning under changing environmental conditions, where it is required to flexibly switch from one behavior to another. However, two unsolved questions are particularly impor¬tant for improving our knowledge of the evolutionary advantages provided by learning, and are addressed in the present work. First, because it is possible to learn the wrong behavior when a task is too complex, the learning rules and their underlying psychological characteristics that generate truly adaptive behavior must be identified with greater precision, and must be linked to the specific ecological problems faced by each species. A framework for predicting behavior from the definition of a learning rule is developed here. Learning rules capture cognitive features such as the tendency to explore, or the ability to infer rewards associated to unchosen actions. It is shown that these features interact in a non-intuitive way to generate adaptive behavior in social interactions where individuals affect each other's fitness. Such behavioral predictions are used in an evolutionary model to demonstrate that, surprisingly, simple trial-and-error learn¬ing is not always outcompeted by more computationally demanding inference-based learning, when population members interact in pairwise social interactions. A second question in the evolution of learning is its link with and relative advantage compared to other simpler forms of phenotypic plasticity. After providing a conceptual clarification on the distinction between genetically determined vs. learned responses to environmental stimuli, a new factor in the evo¬lution of learning is proposed: environmental complexity. A simple mathematical model shows that a measure of environmental complexity, the number of possible stimuli in one's environ¬ment, is critical for the evolution of learning. In conclusion, this work opens roads for modeling interactions between evolving species and their environment in order to predict how natural se¬lection shapes animals' cognitive abilities. - La capacité d'apprendre à associer des sensations perceptives à des actions motrices appropriées est sous-jacente au succès évolutif de nombreuses espèces, depuis les insectes jusqu'aux êtres hu¬mains. L'importance évolutive de l'apprentissage est depuis longtemps un sujet d'intérêt pour les biologistes de l'évolution, et ces derniers mettent l'accent sur le bénéfice de l'apprentissage lorsque les conditions environnementales sont changeantes, car dans ce cas il est nécessaire de passer de manière flexible d'un comportement à l'autre. Cependant, deux questions non résolues sont importantes afin d'améliorer notre savoir quant aux avantages évolutifs procurés par l'apprentissage. Premièrement, puisqu'il est possible d'apprendre un comportement incorrect quand une tâche est trop complexe, les règles d'apprentissage qui permettent d'atteindre un com¬portement réellement adaptatif doivent être identifiées avec une plus grande précision, et doivent être mises en relation avec les problèmes écologiques spécifiques rencontrés par chaque espèce. Un cadre théorique ayant pour but de prédire le comportement à partir de la définition d'une règle d'apprentissage est développé ici. Il est démontré que les caractéristiques cognitives, telles que la tendance à explorer ou la capacité d'inférer les récompenses liées à des actions non ex¬périmentées, interagissent de manière non-intuitive dans les interactions sociales pour produire des comportements adaptatifs. Ces prédictions comportementales sont utilisées dans un modèle évolutif afin de démontrer que, de manière surprenante, l'apprentissage simple par essai-et-erreur n'est pas toujours battu par l'apprentissage basé sur l'inférence qui est pourtant plus exigeant en puissance de calcul, lorsque les membres d'une population interagissent socialement par pair. Une deuxième question quant à l'évolution de l'apprentissage concerne son lien et son avantage relatif vis-à-vis d'autres formes plus simples de plasticité phénotypique. Après avoir clarifié la distinction entre réponses aux stimuli génétiquement déterminées ou apprises, un nouveau fac¬teur favorisant l'évolution de l'apprentissage est proposé : la complexité environnementale. Un modèle mathématique permet de montrer qu'une mesure de la complexité environnementale - le nombre de stimuli rencontrés dans l'environnement - a un rôle fondamental pour l'évolution de l'apprentissage. En conclusion, ce travail ouvre de nombreuses perspectives quant à la mo¬délisation des interactions entre les espèces en évolution et leur environnement, dans le but de comprendre comment la sélection naturelle façonne les capacités cognitives des animaux.

Green vs. Lempert functions: a minimal example

The Lempert function for a set of poles in a domain of Cn at a point z is obtained by taking a certain infimum over all analytic disks going through the poles and the point z, and majorizes the corresponding multi-pole pluricomplex Green function. Coman proved that both coincide in the case of sets of two poles in the unit ball. We give an example of a set of three poles in the unit ball where this equality fails.

On the system of the functions x (s) / (s-r)k

"Vegeu el resum a l'inici del document del fitxer adjunt."

Role of disease activity for decision making ability in early multiple sclerosis

Background and purpose: Decision making (DM) has been defined as the process through which a person forms preferences, selects and executes actions, and evaluates the outcome related to a selected choice. This ability represents an important factor for adequate behaviour in everyday life. DM impairment in multiple sclerosis (MS) has been previously reported. The purpose of the present study was to assess DM in patients with MS at the earliest clinically detectable time point of the disease. Methods: Patients with definite (n=109) or possible (clinically isolated syndrome, CIS; n=56) MS, a short disease duration (mean 2.3 years) and a minor neurological disability (mean EDSS 1.8) were compared to 50 healthy controls aged 18 to 60 years (mean age 32.2) using the Iowa Gambling Task (IGT). Subjects had to select a card from any of 4 decks (A/B [disadvantageous]; C/D [advantageous]). The game consisted of 100 trials then grouped in blocks of 20 cards for data analysis. Skill in DM was assessed by means of a learning index (LI) defined as the difference between the averaged last three block indexes and first two block indexes (LI=[(BI-3+BI-4+BI-5)/3-(BI-1+B2)/2]). Non parametric tests were used for statistical analysis. Results: LI was higher in the control group (0.24, SD 0.44) than in the MS group (0.21, SD 0.38), however without reaching statistical significance (p=0.7). Interesting differences were detected when MS patients were grouped according to phenotype. A trend to a difference between MS subgroups and controls was observed for LI (p=0.06), which became significant between MS subgroups (p=0.03). CIS patients who confirmed MS diagnosis by presenting a second relapse after study entry showed a dysfunction in the IGT in comparison to the other CIS (p=0.01) and definite MS (p=0.04) patients. In the opposite, CIS patients characterised by not entirely fulfilled McDonald criteria at inclusion and absence of relapse during the study showed an normal learning pattern on the IGT. Finally, comparing MS patients who developed relapses after study entry, those who remained clinically stable and controls, we observed impaired performances only in relapsing patients in comparison to stable patients (p=0.008) and controls (p=0.03). Discussion: These results raise the assumption of a sustained role for both MS relapsing activity and disease heterogeneity (i.e. infra-clinical severity or activity of MS) in the impaired process of decision making.

Effects of a dual inhibitor of angiotensin converting enzyme and neutral endopeptidase, MDL 100,240, on endocrine and renal functions in healthy volunteers.

OBJECTIVE: To investigate the endocrine and renal effects of the dual inhibitor of angiotensin converting enzyme and neutral endopeptidase, MDL 100,240. DESIGN: A randomized, placebo-controlled, crossover study was performed in 12 healthy volunteers. METHODS: MDL 100,240 was administered intravenously over 20 min at single doses of 6.25 and 25 mg in subjects with a sodium intake of 280 (n = 6) or 80 (n = 6) mmol/day. Measurements were taken of supine and standing blood pressure, plasma angiotensin converting enzyme activity, angiotensin II, atrial natriuretic peptide, urinary atrial natriuretic peptide and cyclic GMP excretion, effective renal plasma flow and the glomerular filtration rate as p-aminohippurate and inulin clearances, electrolytes and segmental tubular function by endogenous lithium clearance. RESULTS: Supine systolic blood pressure was consistently decreased by MDL 100,240, particularly after the high dose and during the low-salt intake. Diastolic blood pressure and heart rate did not change. Plasma angiotensin converting enzyme activity decreased rapidly and dose-dependently. In both the high- and the low-salt treatment groups, plasma angiotensin II levels fell and renin activity rose accordingly, while plasma atrial natriuretic peptide levels remained unchanged. In contrast, urinary atrial natriuretic peptide excretion increased dose-dependently under both diets, as did urinary cyclic GMP excretion. Effective renal plasma flow and the glomerular filtration rate did not change. The urinary flow rate increased markedly during the first 2 h following administration of either dose of MDL 100,240 (P < 0.001) and, similarly, sodium excretion tended to increase from 0 to 4 h after the dose (P = 0.07). Potassium excretion remained stable. Proximal and distal fractional sodium reabsorption were not significantly altered by the treatment. Uric acid excretion was increased. The safety and clinical tolerance of MDL 100,240 were good. CONCLUSIONS: The increased fall in blood pressure in normal volunteers together with the preservation of renal hemodynamics and the increased urinary volume, atrial natriuretic peptide and cyclic GMP excretion distinguish MDL 100,240 as a double-enzyme inhibitor from inhibitors of the angiotensin converting enzyme alone. The differences appear to be due, at least in part, to increased renal exposure to atrial natriuretic peptide following neutral endopeptidase blockade.

Briefing Paper on Health Inequalities for Elected Members of Local Government (ROI)

The social and economic circumstances in which people live strongly influence their chances to be healthy.  Factors such as housing, transport, environment, education and employment are just some of the functions of local government that influence health. IPH, in partnership with CAN and Nexus developed a briefing paper to support elected members of local government to ensure that the decision in which they are involved have a positive impact on health, especially the health of vulnerable groups.  It provides councillors with information to assist in contributing to a better quality of life for constituents with healthier decision making in areas such as safer environments, increased education opportunities, better housing stock and improved public transport availability.