What makes one person paranoid and another person anxious? The differential prediction of social anxiety and persecutory ideation in an experimental situation

The study shows that social anxiety and persecutory ideation share many of the same predictive factors. Non-clinical paranoia may be a type of anxious fear. However, perceptual anomalies are a distinct predictor of paranoia. In the context of an individual feeling anxious, the occurrence of odd internal feelings in social situations may lead to delusional ideas through a sense of" things not seeming right". The study illustrates the approach of focusing on experiences such as paranoid thinking rather than diagnoses such as schizophrenia.

Psychological and Family Factors Associated with Suicidal Ideation in Pre-Adolescents

To assess the psychological and family factors associated with suicidal ideation in preadolescent children, we studied a sample of 361 students, average age 9 years old. Twogroups were formed, on the basis of the presence (n = 34) or absence (n = 44) of suicidal ideation. Suicidal ideation was assessed with the Children’s Depression Inventory and the Children’s Depression Rating Scale-Revised. Depression, hopelessness, self-esteem, and perceived family environment were compared in both the suicidal ideation and the control groups. Students with suicidal ideation generally presented greater depressive symptoms and hopelessness, and lower self-esteem and family expressiveness, although there weredifferences both between sexes, and when the variable depression was controlled. Identifying these risk factors in pre-adolescents may have an impact on prevention of suicidal behavior at higher risk ages

Nuclear Weapons as Symbols. The Role of Norms in Nuclear Policy Making

Throughout history, nuclear weapons have been considered to be the ultimate weapons. This understanding largely detached them from the portfolio of conventional military means and assigned them a symbolic meaning that influenced the identity and norms creation of nations. In most countries today, the development of nuclear weapons is considered morally prohibitive, incompatible with a country’s identity and international outlook. In some states, however, these negative norms are overridden by a positive set of norms, causing nuclear weapons to become either symbols of invulnerability to perceived threats or the regalia of major power status. Main purpose of this paper is to explore on the conditions that cause most states to develop a moral aversion to nuclear weapons, yet effectively lead to their glorification in others. Many studies on the normative understanding of nuclear weapons consider the existence of a negative normative predisposition, often referred to as ‘nuclear taboo’, as a major factor in preventing their acquisition and use. Other studies acknowledge the existence of a nuclear taboo inhibiting the use of nuclear weapons, but point to the existence of the opposing effect of norms, frequently referred to as the ‘nuclear myth’, when it comes to the acquisition of nuclear weapons. This myth emerges when certain symbolic meanings are attached to nuclear weapons, such as a state’s identity, self-image, and its desired position in the international system. With 180 odd countries in the world abstaining from the acquisition of nuclear weapons and 8 countries in possession of them (with two further countries assumed to have pursued their acquisition), one might consider the dominance of the nuclear taboo over the nuclear myth to be the rule. The core question is thus why and how this relationship reversed in the case of defectors.

Democracy and the curse of natural resources

We propose a theoretical model to explain empirical regularities related to the curse of natural resources. This is an explicitly political model which emphasizes the behavior and incentives of politicians. We extend the standard voting model to give voters political control beyond the elections. This gives rise to a new restriction into our political economy model: policies should not give rise to a revolution. Our model clarifies when resource discoveries might lead to revolutions, namely, in countries with weak institutions. Natural resources may be bad for democracy by harming political turnover. Our model also suggests a non-linear dependence of human capital on natural resources. For low levels of democracy human capital depends negatively on natural resources, while for high levels of democracy the dependence is reversed. This theoretical finding is corroborated in both cross section and panel data regressions.

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.

Deconstructing Shocks and Persistence in OECD Real Exchange Rates

This paper analyzes the persistence of shocks that affect the real exchange rates for a panel of seventeen OECD developed countries during the post-Bretton Woods era. The adoption of a panel data framework allows us to distinguish two different sources of shocks, i.e. the idiosyncratic and the common shocks, each of which may have di¤erent persistence patterns on the real exchange rates. We first investigate the stochastic properties of the panel data set using panel stationarity tests that simultaneously consider both the presence of cross-section dependence and multiple structural breaks that have not received much attention in previous persistence analyses. Empirical results indicate that real exchange rates are non-stationary when the analysis does not account for structural breaks, although this conclusion is reversed when they are modeled. Consequently, misspecification errors due to the non-consideration of structural breaks leads to upward biased shocks' persistence measures. The persistence measures for the idiosyncratic and common shocks have been estimated in this paper always turn out to be less than one year.

CO2 emissions and economic activity: heterogeneity across countries and non stationary series

This paper explores the homogeneity of the functional form, the parameters, and the turning point, when appropriate, of the relationship between CO2 emissions and economic activity for 31 countries (28 OECD, Brazil, China, and India) during the period 1950 to 2006 using cointegration analysis. With a sample highly overlapped over time between countries, the result reveals that the homogeneity across countries is rejected, both in functional form and in the parameters of long term relationship. This confirms the relevance of considering the heterogeneity in exploring the relationship between air pollution and economic activity to avoid spurious parameter estimates and infer a wrong behavior of the functional form, which could lead to induce that the relationship is reversed when in fact it is direct.

Delta9-tetrahydrocannabinol decreases somatic and motivational manifestations of nicotine withdrawal in mice

The possible interactions between Delta9-tetrahydrocannabinol (THC) and nicotine remain unclear in spite of the current association of cannabis and tobacco in humans. The aim of the present study was to explore the interactions between these two drugs of abuse by evaluating the consequences of THC administration on the somatic manifestations and the aversive motivational state associated to nicotine withdrawal in mice. Acute THC administration significantly decreased the incidence of several nicotine withdrawal signs precipitated by mecamylamine or naloxone, such as wet-dog-shakes, paw tremor and scratches. In both experimental conditions, the global withdrawal score was also significantly attenuated by acute THC administration. THC also reversed conditioned place aversion associated to naloxone precipitated nicotine withdrawal. We have then evaluated whether this effect of THC was due to possible adaptive changes induced by chronic nicotine on CB1 cannabinoid receptors. The stimulation of GTPS-binding proteins by the cannabinoid agonist WIN 55,212-2 and the density of CB1 cannabinoid receptor binding labelled with [3H] CP-55,940 were not modified by chronic nicotine treatment in the different brain structures investigated. Finally, we evaluated the consequences of THC administration on c-Fos expression in several brain structures after chronic nicotine administration and withdrawal. c-Fos was decreased in the caudate putamen and the dentate gyrus after mecamylamine precipitated nicotine withdrawal. However, acute THC administration did not modify c-Fos expression under these experimental conditions. Taken together, these results indicate that THC administration attenuated somatic signs of nicotine withdrawal and this effect was not associated to compensatory changes on CB1 cannabinoid receptors during chronic nicotine administration. In addition, THC also ameliorated the aversive motivational consequences of nicotine withdrawal.

BDNF impairment in the hippocampus is related to enhanced despair behavior in CB1 knockout mice

Stress can cause damage and atrophy of neurons in the hippocampus by deregulating the expression of neurotrophic factors that promote neuronal plasticity. The endocannabinoid system represents a physiological substrate involved in neuroprotection at both cellular and emotional levels. The lack of CB1 receptor alters neuronal plasticity and originates an anxiety-like phenotype in mice. In the present study, CB1 knockout mice exhibited an augmented response to stress revealed by the increased despair behavior and corticosterone levels showed in the tail suspension test and decreased brain derived neurotrophic factor (BDNF) levels in the hippocampus. Interestingly, local administration of BDNF in the hippocampus reversed the increased despair behavior of CB1 knockout mice, confirming the crucial role played by BDNF on the emotional impairment of these mutants. The neurotrophic deficiency seems to be specific for BDNF since no differences were found in the levels of NGF and NT-3, two additional neurotrophic factors. Moreover, BDNF impairment is not related to the activity of its specific receptor TrkB or the activity of the transcription factor CREB. These results suggest that the lack of CB1 receptor originates an enhanced response to stress and neuronal plasticity by decreasing BDNF levels in the hippocampus that lead to impairment in the responses to emotional disturbances.

A short motif in Drosophila SECIS Binding Protein 2 provides differential binding affinity to SECIS RNA hairpins

Selenoproteins contain the amino acid selenocysteine which is encoded by a UGA Sec codon. Recoding UGA Sec requires a complex mechanism, comprising the cis-acting SECIS RNA hairpin in the 3′UTR of selenoprotein mRNAs, and trans-acting factors. Among these, the SECIS Binding Protein 2 (SBP2) is central to the mechanism. SBP2 has been so far functionally characterized only in rats and humans. In this work, we report the characterization of the Drosophila melanogaster SBP2 (dSBP2). Despite its shorter length, it retained the same selenoprotein synthesis-promoting capabilities as the mammalian counterpart. However, a major difference resides in the SECIS recognition pattern: while human SBP2 (hSBP2) binds the distinct form 1 and 2 SECIS RNAs with similar affinities, dSBP2 exhibits high affinity toward form 2 only. In addition, we report the identification of a K (lysine)-rich domain in all SBP2s, essential for SECIS and 60S ribosomal subunit binding, differing from the well-characterized L7Ae RNA-binding domain. Swapping only five amino acids between dSBP2 and hSBP2 in the K-rich domain conferred reversed SECIS-binding properties to the proteins, thus unveiling an important sequence for form 1 binding.

THC prevents MDMA neurotoxicity in mice

The majority of MDMA (ecstasy) recreational users also consume cannabis. Despite the rewarding effects that both drugs have, they induce several opposite pharmacological responses. MDMA causes hyperthermia, oxidative stress and neuronal damage, especially at warm ambient temperature. However, THC, the main psychoactive compound of cannabis, produces hypothermic, anti-inflammatory and antioxidant effects. Therefore, THC may have a neuroprotective effect against MDMA-induced neurotoxicity. Mice receiving a neurotoxic regimen of MDMA (20 mg/kg ×4) were pretreated with THC (3 mg/kg ×4) at room (21°C) and at warm (26°C) temperature, and body temperature, striatal glial activation and DA terminal loss were assessed. To find out the mechanisms by which THC may prevent MDMA hyperthermia and neurotoxicity, the same procedure was carried out in animals pretreated with the CB1 receptor antagonist AM251 and the CB2 receptor antagonist AM630, as well as in CB1, CB2 and CB1/CB2 deficient mice. THC prevented MDMA-induced-hyperthermia and glial activation in animals housed at both room and warm temperature. Surprisingly, MDMA-induced DA terminal loss was only observed in animals housed at warm but not at room temperature, and this neurotoxic effect was reversed by THC administration. However, THC did not prevent MDMA-induced hyperthermia, glial activation, and DA terminal loss in animals treated with the CB1 receptor antagonist AM251, neither in CB1 and CB1/CB2 knockout mice. On the other hand, THC prevented MDMA-induced hyperthermia and DA terminal loss, but only partially suppressed glial activation in animals treated with the CB2 cannabinoid antagonist and in CB2 knockout animals. Our results indicate that THC protects against MDMA neurotoxicity, and suggest that these neuroprotective actions are primarily mediated by the reduction of hyperthermia through the activation of CB1 receptor, although CB2 receptors may also contribute to attenuate neuroinflammation in this process.

The Three Horsemen of Growth: Plague, War and Urbanization in Early Modern Europe

How did Europe overtake China? We construct a simple Malthusian model with two sectors, and use it to explain how European per capita incomes and urbanization rates could surge ahead of Chinese ones. That living standards could exceed subsistence levels at all in a Malthusian setting should be surprising. Rising fertility and falling mortality ought to have reversed any gains. We show that productivity growth in Europe can only explain a small fraction of rising living standards. Population dynamics - changes of the birth and death schedules - were far more important drivers of the longrun Malthusian equilibrium. The Black Death raised wages substantially, creating important knock-on effects. Because of Engel's Law, demand for urban products increased, raising urban wages and attracting migrants from rural areas. European cities were unhealthy, especially compared to Far Eastern ones. Urbanization pushed up aggregate death rates. This effect was reinforced by more frequent wars (fed by city wealth) and disease spread by trade. Thus, higher wages themselves reduced population pressure. Without technological change, our model can account for the sharp rise in European urbanization as well as permanently higher per capita incomes. We complement our calibration exercise with a detailed analysis of intra-European growth in the early modern period. Using a panel of European states in the period 1300-1700, we show that war frequency can explain a good share of the divergent fortunes within Europe.

Turbulence and unemployment in a job matching model

According to Ljungqvist and Sargent (1998), high European unemployment since the 1980s can be explained by a rise in economic turbulence, leading to greater numbers of unemployed workers with obsolete skills. These workers refuse new jobs due to high unemployment benefits. In this paper we reassess the turbulence-unemployment relationship using a matching model with endogenous job destruction. In our model, higher turbulence reduces the incentives of employed workers to leave their jobs. If turbulence has only a tiny effect on the skills of workers experiencing endogenous separation, then the results of Lungqvist and Sargent (1998, 2004) are reversed, and higher turbulence leads to a reduction in unemployment. Thus, changes in turbulence cannot provide an explanation for European unemployment that reconciles the incentives of both unemployed and employed workers.

Does foreign direct investment crowd out domestic entrepreneurship?

In analyzing firm entry and exit across Belgian manufacturing industries,this paper presents evidence that import competition and foreign directinvestment discourage entry and stimulate exit of domestic entrepreneurs.These results are in line with theoretical occupational choice modelsthat predict foreign direct investment would crowd out domesticentrepreneurs through their selections in product and labor markets.However, the empirical results also suggest that this crowding out effectmay be moderated or even reversed in the long-run due to the long termpositive effects of FDI on domestic entrpreneurship as a result oflearning, demonstration, networking and linkage effects between foreignand domestic firms.

Lobbying, innovation and protectionist cycles

This paper explains why trade liberalizations occur in developing countries,and why they are often reversed. It does so by focusing on the use oflobbying for protection by import competing firms as a means to postponecostly product quality upgrades to keep up with foreign competitors. Giventhe availability of a political market for import tariffs, domestic firmswill lobby for a sequence of tariffs that insulate domestic profits from awidening quality gap, thereby allowing adjustment to be postponed. But asthe contributions required by the government grow with the size of thequality gap, it will be optimal to adjust quality and to decrease thelobbying effort at some time, leading to liberalization and technologicalcatch-up. But then the equilibrium tariff will again be small and "cheap",and it will pay to start lobbying anew, until the next quality adjustment.Therefore, cycles in protection will occur as a result of the use oflobbying as a substitute for innovation. The model thus sheds new light onthe impact of the costs of protection on the effectiveness of the lobbyingeffort over time, and on their implications for the timing and the timehorizon of trade reforms in developing countries.