Measuring belief in conspiracy theories: Validation of a French and English single-item scale

We designed, in French and in English, a single-item scale to measure people’s general tendency to believe in conspiracy theories. The validity and reliability of this scale was assessed in 3 studies (total N = 555). In Study 1 (N = 152), positive correlations between the single-item scale and 3 other conspiracy belief scales on a French student sample suggested good concurrent validity. In Study 2 (N = 292), we replicated these results on a larger and more heterogeneous Internet American sample. Moreover, the scale showed good predictive validity—responses predicted participants’ willingness to receive a bi-monthly newsletter about alleged conspiracy theories. Finally, in Study 3 (N = 111), we observed good test-retest reliability and demonstrated both convergent and discriminant validity of the single-item scale. Overall these results suggest that the single-item conspiracy belief scale has good validity and reliability and may be used to measure conspiracy belief in favor of lengthier existing scales. In addition, the validation of the single-item scale led us to develop and start validating French versions of the Generic Conspiracist Beliefs scale, the Conspiracy Mentality Questionnaire, and a 10-item version (instead of the 15-item original version) of the Belief in Conspiracy Theories Inventory

Central nervous system functions of PAK protein family: From spine morphogenesis to mental retardation

Several of the genes currently known to be associated, when mutated, with mental retardation, code for molecules directly involved in Rho guanosine triphosphatase (GTPase) signaling. These include PAK3, a member of the PAK protein kinase family, which are important effectors of small GTPases. In many systems, PAK kinases play crucial roles regulating complex mechanisms such as cell migration, differentiation, or survival. Their precise functions in the central nervous system remain, however, unclear. Although their activity does not seem to be required for normal brain development, several recent studies point to a possible involvement in more subtle mechanisms such as neurite outgrowth, spine morphogenesis or synapse formation, and plasticity. This article reviews this information in the light of the current knowledge available on the molecular characteristics of the different members of this family and discuss the mechanisms through which they might contribute to cognitive function

Activity-Dependent PSD Formation and Stabilization of Newly Formed Spines in Hippocampal Slice Cultures

Development and remodeling of synaptic networks occurs through a continuous turnover of dendritic spines. However, the mechanisms that regulate the formation and stabilization of newly formed spines remain poorly understood. Here, we applied repetitive confocal imaging to hippocampal slice cultures to address these issues. We find that, although the turnover rate of protrusions progressively decreased during development, the process of stabilization of new spines remained comparable both in terms of time course and low level of efficacy. Irrespective of the developmental stage, most new protrusions were quickly eliminated, in particular filopodia, which only occasionally lead to the formation of stable dendritic spines. We also found that the stabilization of new protrusions was determined within a critical period of 24 h and that this coincided with an enlargement of the spine head and the expression of tagged PSD-95. Blockade of postsynaptic AMPA and NMDA receptors significantly reduced the capacity of new spines to express tagged PSD-95 and decreased their probability to be stabilized. These results suggest a model in which synaptic development is associated with an extensive, nonspecific growth of protrusions followed by stabilization of a few of them through a mechanism that involves activity-driven formation of a postsynaptic densit

PSD-95 promotes synaptogenesis and multiinnervated spine formation through nitric oxide signaling

Postsynaptic density 95 (PSD-95) is an important regulator of synaptic structure and plasticity. However, its contribution to synapse formation and organization remains unclear. Using a combined electron microscopic, genetic, and pharmacological approach, we uncover a new mechanism through which PSD-95 regulates synaptogenesis. We find that PSD-95 overexpression affected spine morphology but also promoted the formation of multiinnervated spines (MISs) contacted by up to seven presynaptic terminals. The formation of multiple contacts was specifically prevented by deletion of the PDZ2 domain of PSD-95, which interacts with nitric oxide (NO) synthase (NOS). Similarly, PSD-95 overexpression combined with small interfering RNA–mediated down-regulation or the pharmacological blockade of NOS prevented axon differentiation into varicosities and multisynapse formation. Conversely, treatment of hippocampal slices with an NO donor or cyclic guanosine monophosphate analogue induced MISs. NOS blockade also reduced spine and synapse density in developing hippocampal cultures. These results indicate that the postsynaptic site, through an NOS–PSD-95 interaction and NO signaling, promotes synapse formation with nearby axons

Effect of annealing treatments on photoluminescence and charge storage mechanism in silicon-rich SiNx:H films

In this study, a wide range of a-SiNx:H films with an excess of silicon (20 to 50%) were prepared with an electron-cyclotron resonance plasma-enhanced chemical vapor deposition system under the flows of NH3 and SiH4. The silicon-rich a-SiNx:H films (SRSN) were sandwiched between a bottom thermal SiO2 and a top Si3N4 layer, and subsequently annealed within the temperature range of 500-1100°C in N2 to study the effect of annealing temperature on light-emitting and charge storage properties. A strong visible photoluminescence (PL) at room temperature has been observed for the as-deposited SRSN films as well as for films annealed up to 1100°C. The possible origins of the PL are briefly discussed. The authors have succeeded in the formation of amorphous Si quantum dots with an average size of about 3 to 3.6 nm by varying excess amount of Si and annealing temperature. Electrical properties have been investigated on Al/Si3N4/SRSN/SiO2/Si structures by capacitance-voltage and conductance-voltage analysis techniques. A significant memory window of 4.45 V was obtained at a low operating voltage of ± 8 V for the sample containing 25% excess silicon and annealed at 1000°C, indicating its utility in low-power memory devices

Comparison of MRI properties between multimeric DOTAGA and DO3A gadolinium-dendron conjugates

The inherent lack of sensitivity of MRI needs the development of new Gd contrast agents in order to extend 20Hz,37%, the application of this technique to cellular imaging. For this purpose, two multimeric MR contrast agents obtained by peptidic coupling between an amido amine dendron and GdDOTAGA chelates (premetalation strategy, G1-4GdDOTAGA) or DO3A derivatives which then were postmetalated (G1-4GdDO-3A) have been prepared. By comparison to the monomers, an increase of longitudinal relaxivity has been observed for both structures. Especially for G1-4GdDO-3A, a marked increase is observed between 20 and 60 MHz. This structure differs from G1-4GdDOTAGA by an increased rigidity due to the aromatic linker between each chelate and the organic framework. This has the effect of limiting local rotational movements, which has a positive impact on relaxivity

“I know things they don’t know!” The role of need for uniqueness in belief in conspiracy theories

In the current research, we investigated whether belief in conspiracy theories satisfies people’s need for uniqueness. We found that the tendency to believe in conspiracy theories was associated with the feeling of possessing scarce information about the situations explained by the conspiracy theories (Study 1) and higher need for uniqueness (Study 2). A further two studies using two different manipulations of need for uniqueness (Studies 3 and 4), showed that people in a high need for uniqueness condition displayed higher conspiracy belief than people in a low need for uniqueness condition. This conclusion is strengthened by a small-scale meta-analysis. These studies suggest that conspiracy theories may serve people’s desire to be unique, highlighting a motivational underpinning of conspiracy belief

Almost Linear B\"uchi Automata

We introduce a new fragment of Linear temporal logic (LTL) called LIO and a new class of Buechi automata (BA) called Almost linear Buechi automata (ALBA). We provide effective translations between LIO and ALBA showing that the two formalisms are expressively equivalent. While standard translations of LTL into BA use some intermediate formalisms, the presented translation of LIO into ALBA is direct. As we expect applications of ALBA in model checking, we compare the expressiveness of ALBA with other classes of Buechi automata studied in this context and we indicate possible applications

Witnessing effective entanglement over a 2km fiber channel

We present a fiber-based continuous-variable quantum key distribution system. In the scheme, a quantum signal of two non-orthogonal weak optical coherent states is sent through a fiber-based quantum channel. The receiver simultaneously measures conjugate quadratures of the light using two homodyne detectors. From the measured Q-function of the transmitted signal, we estimate the attenuation and the excess noise caused by the channel. The estimated excess noise originating from the channel and the channel attenuation including the quantum efficiency of the detection setup is investigated with respect to the detection of effective entanglement. The local oscillator is considered in the verification. We witness effective entanglement with a channel length of up to 2km.Comment: 11 pages, 5 figure