Binge eating in binge eating disorder: a break-down of emotion regulatory process?

Current explanatory models for binge eating in binge eating disorder (BED) mostly rely onmodels for bulimianervosa (BN), although research indicates different antecedents for binge eating in BED. This studyinvestigates antecedents and maintaining factors in terms of positive mood, negative mood and tension in asample of 22 women with BED using ecological momentary assessment over a 1-week. Values for negativemood were higher and those for positive mood lower during binge days compared with non-binge days.During binge days, negative mood and tension both strongly and significantly increased and positive moodstrongly and significantly decreased at the first binge episode, followed by a slight though significant, andlonger lasting decrease (negative mood, tension) or increase (positive mood) during a 4-h observation periodfollowing binge eating. Binge eating in BED seems to be triggered by an immediate breakdown of emotionregulation. There are no indications of an accumulation of negative mood triggering binge eating followed byimmediate reinforcing mechanisms in terms of substantial and stable improvement of mood as observed inBN. These differences implicate a further specification of etiological models and could serve as a basis fordeveloping new treatment approaches for BED.

In Search of a theory of debt management

A growing literature integrates theories of debt management into models of optimal fiscal policy. One promising theory argues that the composition of government debt should be chosen so that fluctuations in the market value of debt offset changes in expected future deficits. This complete market approach to debt management is valid even when the government only issues non-contingent bonds. A number of authors conclude from this approach that governments should issue long term debt and invest in short term assets. We argue that the conclusions of this approach are too fragile to serve as a basis for policy recommendations. This is because bonds at different maturities have highly correlated returns, causing the determination of the optimal portfolio to be ill-conditioned. To make this point concrete we examine the implications of this approach to debt management in various models, both analytically and using numerical methods calibrated to the US economy. We find the complete market approach recommends asset positions which are huge multiples of GDP. Introducing persistent shocks or capital accumulation only worsens this problem. Increasing the volatility of interest rates through habits partly reduces the size of these simulations we find no presumption that governments should issue long term debt ? policy recommendations can be easily reversed through small perturbations in the specification of shocks or small variations in the maturity of bonds issued. We further extend the literature by removing the assumption that governments every period costlessly repurchase all outstanding debt. This exacerbates the size of the required positions, worsens their volatility and in some cases produces instability in debt holdings. We conclude that it is very difficult to insulate fiscal policy from shocks by using the complete markets approach to debt management. Given the limited variability of the yield curve using maturities is a poor way to substitute for state contingent debt. The result is the positions recommended by this approach conflict with a number of features that we believe are important in making bond markets incomplete e.g allowing for transaction costs, liquidity effects, etc.. Until these features are all fully incorporated we remain in search of a theory of debt management capable of providing robust policy insights.

Integració de tècniques per a la comprovació eficient de restriccions d'integritat en la generació de programari per entorns web

Estudi elaborat a partir d’una estada al Politecnico de Milano, Itàlia, entre gener i juny del 2006. Un dels principals objectius de l’Enginyeria del Programari és automatitzar el màxim possible el procés de desenvolupament del programari, reduint costos mitjançant la generació automàtica del programari a partir de la seva especificació. Per assolir-ho, entre altres, cal resoldre el problema de la comprovació eficient de restriccions, que són una part fonamental de l’especificació del programari. Aquest és precisament l’àmbit en què s’està desenvolupant una tesi que presentarà un mètode que poden integrar totes les eines generadores de codi per tal d’assolir una implementació eficient de les restriccions d’integritat. En l’actual fase del projecte s’ha treballat per validar el mètode de la tesi, optimitzant-lo pel cas específic de les aplicacions web i estendre’l per poder tractar també aplicacions basades en workflows. Pel que fa a l’optimització del mètode per aplicacions web, s’han definit una sèrie de paràmetres que permeten configurar la implementació del mètode tenint en compte les necessitats específiques de rendiment de cada aplicació web en particular. Respecte als workflows (cada cop més populars i que s’usen com a definició d’alt nivell per a les aplicacions a desenvolupar) s’ha estudiat quins són els tipus de restriccions que impliquen i com després es pot aplicar el mètode de la tesi sobre aquestes restriccions per tal de generar de forma eficient també les aplicacions basades en workflows.

Influence de deux milieux séquentiels pour la culture d'embryons sur la production d'hormone gonadotrophine chorionique et de progestérone par des cellules JEG-3 et BeWo [Effects of different embryo development media on hCG and progesterone release by JEG-3 and BeWo cells]

Current in vitro fertilisation (IVF) practice requires synchronisation between the¦environment of cultured oocytes and embryos and the surroundings to what they would have¦been exposed to in vivo. Commercial, sequential media follow this requirement but their exact¦composition is not available. We have compared two widely used IVF culture media systems using¦the two choriocarcinoma cell lines JEG-3 and BeWo. The two hormones hCG and progesterone¦were determined in the culture supernatants as endpoints. In both cell lines, but in a more¦pronounced way in JEG-3, progesterone rather than hCG production was stimulated, and a¦higher hormone release was observed in the fertilisation than in the cleavage media. Differences¦between manufacturers were small and did not favour one system over the other. We conclude¦that both sequential media systems can be equally well used in current IVF laboratory practice.¦© 2012 Elsevier Masson SAS. All rights reserved.

Three essays on the psychology of investment and financial markets

Préface My thesis consists of three essays where I consider equilibrium asset prices and investment strategies when the market is likely to experience crashes and possibly sharp windfalls. Although each part is written as an independent and self contained article, the papers share a common behavioral approach in representing investors preferences regarding to extremal returns. Investors utility is defined over their relative performance rather than over their final wealth position, a method first proposed by Markowitz (1952b) and by Kahneman and Tversky (1979), that I extend to incorporate preferences over extremal outcomes. With the failure of the traditional expected utility models in reproducing the observed stylized features of financial markets, the Prospect theory of Kahneman and Tversky (1979) offered the first significant alternative to the expected utility paradigm by considering that people focus on gains and losses rather than on final positions. Under this setting, Barberis, Huang, and Santos (2000) and McQueen and Vorkink (2004) were able to build a representative agent optimization model which solution reproduced some of the observed risk premium and excess volatility. The research in behavioral finance is relatively new and its potential still to explore. The three essays composing my thesis propose to use and extend this setting to study investors behavior and investment strategies in a market where crashes and sharp windfalls are likely to occur. In the first paper, the preferences of a representative agent, relative to time varying positive and negative extremal thresholds are modelled and estimated. A new utility function that conciliates between expected utility maximization and tail-related performance measures is proposed. The model estimation shows that the representative agent preferences reveals a significant level of crash aversion and lottery-pursuit. Assuming a single risky asset economy the proposed specification is able to reproduce some of the distributional features exhibited by financial return series. The second part proposes and illustrates a preference-based asset allocation model taking into account investors crash aversion. Using the skewed t distribution, optimal allocations are characterized as a resulting tradeoff between the distribution four moments. The specification highlights the preference for odd moments and the aversion for even moments. Qualitatively, optimal portfolios are analyzed in terms of firm characteristics and in a setting that reflects real-time asset allocation, a systematic over-performance is obtained compared to the aggregate stock market. Finally, in my third article, dynamic option-based investment strategies are derived and illustrated for investors presenting downside loss aversion. The problem is solved in closed form when the stock market exhibits stochastic volatility and jumps. The specification of downside loss averse utility functions allows corresponding terminal wealth profiles to be expressed as options on the stochastic discount factor contingent on the loss aversion level. Therefore dynamic strategies reduce to the replicating portfolio using exchange traded and well selected options, and the risky stock.

Use of DNA profiles for investigation using a simulated national DNA database: Part I. Partial SGM Plus profiles.

In traditional criminal investigation, uncertainties are often dealt with using a combination of common sense, practical considerations and experience, but rarely with tailored statistical models. For example, in some countries, in order to search for a given profile in the national DNA database, it must have allelic information for six or more of the ten SGM Plus loci for a simple trace. If the profile does not have this amount of information then it cannot be searched in the national DNA database (NDNAD). This requirement (of a result at six or more loci) is not based on a statistical approach, but rather on the feeling that six or more would be sufficient. A statistical approach, however, could be more rigorous and objective and would take into consideration factors such as the probability of adventitious matches relative to the actual database size and/or investigator's requirements in a sensible way. Therefore, this research was undertaken to establish scientific foundations pertaining to the use of partial SGM Plus loci profiles (or similar) for investigation.

Expression analysis of the AtPHO1 gene family in Arabidopsis thaliana and the involvement of AtPHO1 in the regulation of stomatal movements

Résumé Le transfert du phosphate des racines vers les feuilles s'effectue par la voie du xylème. Il a été précédemment démontré que la protéine AtPHO1 était indispensable au transfert du phosphate dans les vaisseaux du xylème des racines chez la plante modèle Arabidopsis thaliana. Le séquençage et l'annotation du génome d'Arabidopsis ont permis d'identifier dix séquences présentant un niveau de similarité significatif avec le gène AtPHO1 et constituant une nouvelle famille de gène appelé la famille de AtPHO1. Basée sur une étude moléculaire et génétique, cette thèse apporte des éléments de réponse pour déterminer le rôle des membres de ia famille de AtPHO1 chez Arabidopsis, inconnue à ce jour. Dans un premier temps, une analyse bioinformatique des séquences protéiques des membres de la famille de AtPHO1 a révélé la présence dans leur région N-terminale d'un domaine nommé SPX. Ce dernier est conservé parmi de nombreuses protéines impliquées dans l'homéostasie du phosphate chez la levure, renforçant ainsi l'hypothèse que les membres de la famille de AtPHO1 auraient comme AtPHO1 un rôle dans l'équilibre du phosphate dans la plante. En parallèle, la localisation tissulaire de l'expression des gènes AtPHO dans Arabidopsis a été identifiée par l'analyse de plantes transgéniques exprimant le gène rapporteur uidA sous le contrôle des promoteurs respectifs des gènes AtPHO. Un profil d'expression de chaque gène AtPHO au cours du développement de la plante a été obtenu. Une expression prédominante au niveau des tissus vasculaires des racines, des feuilles, des tiges et des fleurs a été observée, suggérant que les gènes AtPHO pourraient avoir des fonctions redondantes au niveau du transfert de phosphate dans le cylindre vasculaire de ces différents organes. Toutefois, plusieurs régions promotrices des gènes AtPHO contrôlent également un profil d'expression GUS non-vasculaire, indiquant un rôle putatif des gènes AtPHO dans l'acquisition ou le recyclage de phosphate dans la plante. Dans un deuxième temps, l'analyse de l'expression des gènes AtPHO durant une carence en phosphate a établi que seule l'expression des gènes AtPHO1, AtPHO1; H1 et AtPHO1; H10 est régulée par cette carence. Une étude approfondie de leur expression en réponse à des traitements affectant l'homéostasie du phosphate dans la plante a ensuite démontré leur régulation par différentes voies de signalisation. Ensuite, une analyse détaillée de la régulation de l'expression du gène AtPHO1; H1O dans des feuilles d'Arabidopsis blessées ou déshydratées a révélé que ce gène constitue le premìer gène marqueur d'une nouvelle voie de signalisation induite par l'OPDA, pas par le JA et dépendante de la protéine COI1. Ces résultats démontrent pour la première fois que l'OPDA et le JA peuvent activer différents gènes via des voies de signalisation dépendantes de COI1. Enfin, cette thèse révèle l'identification d'un nouveau rôle de la protéine AtPHO1 dans la régulation de l'action de l'ABA au cours des processus de fermeture stomatique et de germination des graines chez Arabidopsis. Bien que les fonctions exactes des protéines AtPHO restent à être déterminées, ce travail de thèse suggère leur implication dans la propagation de différents signaux dans la plante via la modulation du potentiel membranaire et/ou l'affectation de la composition en ions des cellules comme le font de nombreux transporteurs ou régulateur du transport d'ions. Summary Phosphate is transferred from the roots to the shoot via the xylem. The requirement for AtPHO1 protein to transfer phosphate to the xylem vessels of the root has been previously demonstrated in Arabidopsis thaliana. The sequencing and the annotation of the Arabidopsis genome had allowed the identification of ten sequences that show a significant level of similarity with the AtPHO1 gene. These 10 genes, of unknown functions, constitute a new gene family called the AtPHO1 gene family. Based on a molecular and genetics study, this thesis reveals some information needed to understand the role of the AtPHO1 family members in the plant Arabidopsis. First, a bioinformatics study revealed that the AtPHO sequences contained, in the N-terminal hydrophilic region, a motif called SPX and conserved among multiple proteins involved in phosphate homeostasis in yeast. This finding reinforces the hypothesis that all AtPHO1 family members have, as AtPHO1, a role in phosphate homeostasis. In parallel, we identified the pattern of expression of AtPHO genes in Arabidopsis via analysis of transgenic plants expressing the uidA reporter gene under the control of respective AtPHO promoter regions. The results exhibit a predominant expression of AtPHO genes in vascular tissues of all organs of the plant, implying that these AtPHO genes could have redundant functions in the transfer of phosphate to the vascular cylinder of various organs. The GUS expression pattern for several AtPHO promoter regions was also detected in non-vascular tissue indicating a broad role of AtPHO genes in the acquisition or in the recycling of phosphate in the plant. In a second step, the analysis of the expression of AtPHO genes during phosphate starvation established that only the expression of the AtPHO1, AtPHO1; H1 and AtPHO1; H10 genes were regulated by Pi starvation. Interestingly, different signalling pathways appeared to regulate these three genes during various treatments affecting Pi homeostasis in the plant. The third chapter presents a detailed analysis of the signalling pathways regulating the expression of the AtPHO1; H10 gene in Arabidopsis leaves during wound and dehydrated stresses. Surprisingly, the expression of AtPHO1; H10 was found to be regulated by OPDA (the precursor of JA) but not by JA itself and via the COI1 protein (the central regulator of the JA signalling pathway). These results demonstrated for the first time that OPDA and JA could activate distinct genes via COI1-dependent pathways. Finally, this thesis presents the identification of a novel role of the AtPHO1 protein in the regulation of ABA action in Arabidopsis guard cells and during seed germination. Although the exact role and function of AtPHO1 still need to be determined, these last findings suggest that AtPHO1 and by extension other AtPHO proteins could mediate the propagation of various signals in the plant by modulating the membrane potential and/or by affecting cellular ion composition, as it is the case for many ion transporters or regulators of ion transport.

Bayesian Inference in the Time Varying Cointegration Model

There are both theoretical and empirical reasons for believing that the parameters of macroeconomic models may vary over time. However, work with time-varying parameter models has largely involved Vector autoregressions (VARs), ignoring cointegration. This is despite the fact that cointegration plays an important role in informing macroeconomists on a range of issues. In this paper we develop time varying parameter models which permit cointegration. Time-varying parameter VARs (TVP-VARs) typically use state space representations to model the evolution of parameters. In this paper, we show that it is not sensible to use straightforward extensions of TVP-VARs when allowing for cointegration. Instead we develop a specification which allows for the cointegrating space to evolve over time in a manner comparable to the random walk variation used with TVP-VARs. The properties of our approach are investigated before developing a method of posterior simulation. We use our methods in an empirical investigation involving a permanent/transitory variance decomposition for inflation.

Climbing to the top? Foreign Direct Investment and Property Rights.

This paper operates at the interface of the literature on the impact of foreign direct investment (FDI) on host countries, and the literature on the determinants of institutional quality. We argue that FDI contributes to economic development by improving institutional quality in the host country and we attempt to test this proposition using a large panel data set of 70 developing countries during the period 1981 and 2005, and we show that FDI inflows have a positive and highly significant impact on property rights. The result appears to be very robust and is and not affected by model specification, different control variables, or a particular estimation technique. As far as we are aware this is the first paper to empirically test the FDI – property rights linkage.

Rebound and disinvestment effects in oil consumption and supply resulting from an increase in energy efficiency in the Scottish commercial transport sector

In this paper we use an energy-economy-environment computable general equilibrium (CGE) model of the Scottish economy to examine the impacts of an exogenous increase in energy augmenting technological progress in the domestic commercial Transport sector on the supply and use of energy. We focus our analysis on oil, as the main type of energy input used in commercial transport activity. We find that a 5% increase in energy efficiency in the commercial Transport sector leads to rebound effects in the use of oil-based energy commodities in all time periods, in the target sector and at the economy-wide level. However, our results also suggest that such an efficiency improvement may cause a contraction in capacity in the Scottish oil supply sector. This ‘disinvestment effect’ acts as a constraint on the size of rebound effects. However, the magnitude of rebound effects and presence of the disinvestment effect in the simulations conducted here are sensitive to the specification of key elasticities of substitution in the nested production function for the target sector, particularly the substitutability of energy for non-energy intermediate inputs to production.

A Model of Near-Rational Exuberance

We study how the use of judgement or “add-factors” in forecasting may disturb the set of equilibrium outcomes when agents learn using recursive methods. We isolate conditions under which new phenomena, which we call exuberance equilibria, can exist in a standard self-referential environment. Local indeterminacy is not a requirement for existence. We construct a simple asset pricing example and find that exuberance equilibria, when they exist, can be extremely volatile relative to fundamental equilibria.

Technology shocks and aggregate fluctuations in an estimated hybrid RBC model

This paper contributes to the on-going empirical debate regarding the role of the RBC model and in particular of technology shocks in explaining aggregate fluctuations. To this end we estimate the model’s posterior density using Markov-Chain Monte-Carlo (MCMC) methods. Within this framework we extend Ireland’s (2001, 2004) hybrid estimation approach to allow for a vector autoregressive moving average (VARMA) process to describe the movements and co-movements of the model’s errors not explained by the basic RBC model. The results of marginal likelihood ratio tests reveal that the more general model of the errors significantly improves the model’s fit relative to the VAR and AR alternatives. Moreover, despite setting the RBC model a more difficult task under the VARMA specification, our analysis, based on forecast error and spectral decompositions, suggests that the RBC model is still capable of explaining a significant fraction of the observed variation in macroeconomic aggregates in the post-war U.S. economy.

EFNS guidelines on diagnosis and management of neuromyelitis optica.

BACKGROUND AND PURPOSE: Neuromyelitis optica (NMO) or Devic's disease is a rare inflammatory and demyelinating autoimmune disorder of the central nervous system (CNS) characterized by recurrent attacks of optic neuritis (ON) and longitudinally extensive transverse myelitis (LETM), which is distinct from multiple sclerosis (MS). The guidelines are designed to provide guidance for best clinical practice based on the current state of clinical and scientific knowledge. SEARCH STRATEGY: Evidence for this guideline was collected by searches for original articles, case reports and meta-analyses in the MEDLINE and Cochrane databases. In addition, clinical practice guidelines of professional neurological and rheumatological organizations were studied. RESULTS: Different diagnostic criteria for NMO diagnosis [Wingerchuk et al. Revised NMO criteria, 2006 and Miller et al. National Multiple Sclerosis Society (NMSS) task force criteria, 2008] and features potentially indicative of NMO facilitate the diagnosis. In addition, guidance for the work-up and diagnosis of spatially limited NMO spectrum disorders is provided by the task force. Due to lack of studies fulfilling requirement for the highest levels of evidence, the task force suggests concepts for treatment of acute exacerbations and attack prevention based on expert opinion. CONCLUSIONS: Studies on diagnosis and management of NMO fulfilling requirements for the highest levels of evidence (class I-III rating) are limited, and diagnostic and therapeutic concepts based on expert opinion and consensus of the task force members were assembled for this guideline.

Transcriptional response to cardiac injury in the zebrafish: systematic identification of genes with highly concordant activity across in vivo models.

BACKGROUND: Zebrafish is a clinically-relevant model of heart regeneration. Unlike mammals, it has a remarkable heart repair capacity after injury, and promises novel translational applications. Amputation and cryoinjury models are key research tools for understanding injury response and regeneration in vivo. An understanding of the transcriptional responses following injury is needed to identify key players of heart tissue repair, as well as potential targets for boosting this property in humans. RESULTS: We investigated amputation and cryoinjury in vivo models of heart damage in the zebrafish through unbiased, integrative analyses of independent molecular datasets. To detect genes with potential biological roles, we derived computational prediction models with microarray data from heart amputation experiments. We focused on a top-ranked set of genes highly activated in the early post-injury stage, whose activity was further verified in independent microarray datasets. Next, we performed independent validations of expression responses with qPCR in a cryoinjury model. Across in vivo models, the top candidates showed highly concordant responses at 1 and 3 days post-injury, which highlights the predictive power of our analysis strategies and the possible biological relevance of these genes. Top candidates are significantly involved in cell fate specification and differentiation, and include heart failure markers such as periostin, as well as potential new targets for heart regeneration. For example, ptgis and ca2 were overexpressed, while usp2a, a regulator of the p53 pathway, was down-regulated in our in vivo models. Interestingly, a high activity of ptgis and ca2 has been previously observed in failing hearts from rats and humans. CONCLUSIONS: We identified genes with potential critical roles in the response to cardiac damage in the zebrafish. Their transcriptional activities are reproducible in different in vivo models of cardiac injury.

A Panel Data Investigation of Real Exchange Rate Misalignment and Growth

The paper investigates the role of real exchange rate misalignment on long-run growth for a set of ninety countries using time series data from 1980 to 2004. We first estimate a panel data model (using fixed and random effects) for the real exchange rate, with different model specifications, in order to produce estimates of the equilibrium real exchange rate and this is then used to construct measures of real exchange rate misalignment. We also provide an alternative set of estimates of real exchange rate misalignment using panel cointegration methods. The variables used in our real exchange rate models are: real per capita GDP; net foreign assets; terms of trade and government consumption. The results for the two-step System GMM panel growth models indicate that the coefficients for real exchange rate misalignment are positive for different model specification and samples, which means that a more depreciated (appreciated) real exchange rate helps (harms) long-run growth. The estimated coefficients are higher for developing and emerging countries.