While particle therapy has been used for decades for cancer treatment, there is still a lack of information on the molecular mechanisms of biomolecules radiolysis by accelerated ions. Here, we examine the effects of accelerated protons on highly concentrated native myoglobin, by means of Fourier transform infrared and UV-Visible spectroscopies. Upon irradiation, the secondary structure of the protein is drastically modified, from mostly alpha helices conformation to mostly beta elements at highest fluence.
View Article and Find Full Text PDFObjective: Despite their potential in improving health behaviors, such as physical activity (PA), the effectiveness of interventions targeting automatic precursors remains contrasted. We examined the effects of a single session of ABC training - a personalized consequence-based approach-avoidance training - on PA, relative to an active control condition and a control condition.
Methods: Middle-aged US participants (N = 360, 53 % of women) either completed an ABC training (being instructed to approach PA to obtain self-relevant consequences), an approach-avoidance training (approaching PA in 90 % of trials), or a control training (approaching PA in 50 % of trials).
Green and digital transitions will induce tremendous demand for metals and semiconductors. This raises concerns about the availability of materials in the rather near future. Addressing this challenge requires an unprecedented effort to discover new materials that are more sustainable and also to expand their functionalities beyond conventional material limits.
View Article and Find Full Text PDFBackground: Social comparisons between pupils are especially relevant at school. Such comparisons influence self-perception and performance. When pupils evaluate themselves more negatively and perform worse after an upward comparison (with a better off pupil) than a downward comparison (with a worse-off pupil), this is a contrast effect.
View Article and Find Full Text PDFSilicon vacancy (VSi) color centers in bulk SiC are excellent electron spin qubits. However, most spin based quantum devices require shallow spin qubits, whose dynamics is often different from that of bulk ones. Here, we demonstrate (i) a new method for creating shallow VSi (V2) spin qubits below the SiC surface by low energy ion implantation through a sacrificial SiO layer, (ii) that these shallow VSi are dipolar coupled to an electronic spin bath, analysed by Hahn echo decay, dynamical decoupling (DD), and optically pumped pulsed electron-electron double resonance experiments (OP-PELDOR), (iii) that their coherence time increases with cooling of the spin bath (from 55 μs at 297 K to 107 μs at 28 K), and that it can be further extended to 220 μs at 100 K by DD, thus demonstrating their relevance for PELDOR-based quantum sensors and processors.
View Article and Find Full Text PDFIn this paper, an improved quantification technique for STEM/EDX measurements of 1D dopant profiles based on the Cliff-Lorimer equation is presented. The technique uses an iterative absorption correction procedure based on density models correlating the local mass density and composition of the specimen. Moreover, a calibration and error estimation procedure based on linear regression and error propagation is proposed in order to estimate the total measurement error in the dopant density.
View Article and Find Full Text PDFAmong the great variety of approach/avoidance tasks, the Visual Approach/Avoidance by the Self Task (VAAST, Rougier et al., 2018) appears to be a promising tool. Previous work showed that the VAAST leads to large and replicable compatibility effects (e.
View Article and Find Full Text PDFPurpose: Mandibular repositioning devices (MRDs) are an effective treatment option for obstructive sleep apnea syndrome (OSAS), particularly in patients who refuse or cannot tolerate continuous positive airway pressure (CPAP). However, sex differences in the response to therapy and predictors of response are not clearly defined. This analysis of data from the long-term prospective ORCADES trial compared MRD efficacy in men and women with OSAS.
View Article and Find Full Text PDFIn light of current concerns with replicability and reporting false-positive effects in psychology, we examine Type I errors and power associated with 2 distinct approaches for the assessment of mediation, namely the component approach (testing individual parameter estimates in the model) and the index approach (testing a single mediational index). We conduct simulations that examine both approaches and show that the most commonly used tests under the index approach risk inflated Type I errors compared with the joint-significance test inspired by the component approach. We argue that the tendency to report only a single mediational index is worrisome for this reason and also because it is often accompanied by a failure to critically examine the individual causal paths underlying the mediational model.
View Article and Find Full Text PDFSchizophrenia is a severely debilitating neurodevelopmental disorder. Establishing a causal link between circuit dysfunction and particular behavioral traits that are relevant to schizophrenia is crucial to shed new light on the mechanisms underlying the pathology. We studied an animal model of the human 22q11 deletion syndrome, the mutation that represents the highest genetic risk of developing schizophrenia.
View Article and Find Full Text PDFSociolinguistic studies generally focus on specific sociolinguistic variables. Consequently, they rarely examine whether different sociolinguistic variables have coherent orientation in a specific language variety (a social or a regional dialect) or whether the speakers freely mix sociolinguistic variants. While different attempts have been made to identify coherence and mixing in the production or perception of dialects, our aim is to answer this question at the level of the cognitive representation of varieties.
View Article and Find Full Text PDFCorrelated activity in the hippocampus drives synaptic plasticity that is necessary for the recruitment of neuronal ensembles underlying fear memory. Sustained neural activity, on the other hand, may trigger homeostatic adaptations. However, whether homeostatic plasticity affects memory function remains unknown.
View Article and Find Full Text PDFPrevious studies suggest that ancient (i.e. evolutionary-based) threats capture attention because human beings possess an inborn module shaped by evolution and dedicated to their detection.
View Article and Find Full Text PDFUltrathin layers (<20 nm) of pBR322 plasmid DNA were deposited onto 2.5 μm thick polyester films and exposed to proton Bragg-peak energies (90-3000 keV) at various fluences. A quantitative analysis of radio-induced DNA damage is reported here in terms of single- and double-strand breaks (SSB and DSB, respectively).
View Article and Find Full Text PDFGood self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes.
View Article and Find Full Text PDFFragile X syndrome (FXS) is caused by the absence of the Fragile X Mental Retardation Protein (FMRP) in neurons. In the mouse, the lack of FMRP is associated with an excessive translation of hundreds of neuronal proteins, notably including postsynaptic proteins. This local protein synthesis deregulation is proposed to underlie the observed defects of glutamatergic synapse maturation and function and to affect preferentially the hundreds of mRNA species that were reported to bind to FMRP.
View Article and Find Full Text PDFHippocampal neurons activated during encoding drive the recall of contextual fear memory. Little is known about how such ensembles emerge during acquisition and eventually form the cellular engram. Manipulating the activity of granule cells (GCs) of the dentate gyrus (DG), we reveal a mechanism of lateral inhibition that modulates the size of the cellular engram.
View Article and Find Full Text PDFNeuroscience studies require technologies able to deliver compounds with both scale and timing compatibility with morphological and physiological synaptic properties. In this light, two-photon flash photolysis has been extensively used to successfully apply glutamate or other neurotransmitters at the synaptic level. However, the set of commercially available caged compounds is restricted and incompatible with studies demanding high cell specificity.
View Article and Find Full Text PDFDo people feel better or worse about themselves when working with someone who is better than they are? We present the first replication of the work of Stapel and Koomen (2005), who showed that being in a competitive vs. cooperative mindset moderates the effects of social comparison on self-evaluation. In Experiment 1, we present a close replication of Stapel and Koomen (2005, Study 2).
View Article and Find Full Text PDFKey Points: The hippocampal CA1 region is highly vulnerable to ischaemic stroke. Two forms of AMPA receptor (AMPAR) plasticity - an anoxic form of long-term potentiation and a delayed increase in Ca(2+) -permeable (CP) AMPARs - contribute to this susceptibility by increasing excitotoxicity. In CA1, the acid-sensing ion channel 1a (ASIC1a) is known to facilitate LTP and contribute to ischaemic acidotoxicity.
View Article and Find Full Text PDFMaintaining a proper balance between excitation and inhibition is essential for the functioning of neuronal networks. However, little is known about the mechanisms through which excitatory activity can affect inhibitory synapse plasticity. Here we used tagged gephyrin, one of the main scaffolding proteins of the postsynaptic density at GABAergic synapses, to monitor the activity-dependent adaptation of perisomatic inhibitory synapses over prolonged periods of time in hippocampal slice cultures.
View Article and Find Full Text PDFSynaptic plasticity mechanisms are usually discussed in terms of changes in synaptic strength. The capacity of excitatory synapses to rapidly modify the membrane expression of glutamate receptors in an activity-dependent manner plays a critical role in learning and memory processes by re-distributing activity within neuronal networks. Recent work has however also shown that functional plasticity properties are associated with a rewiring of synaptic connections and a selective stabilization of activated synapses.
View Article and Find Full Text PDFJ Exp Psychol Learn Mem Cogn
March 2015
Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the categorization of auditory targets and confirmed the multimodal nature of knowledge. In Experiment 2, we proposed to reactivate this mask in a categorization task on visual targets.
View Article and Find Full Text PDFBackground: Excitatory synapses in the CNS are highly dynamic structures that can show activity-dependent remodeling and stabilization in response to learning and memory. Synapses are enveloped with intricate processes of astrocytes known as perisynaptic astrocytic processes (PAPs). PAPs are motile structures displaying rapid actin-dependent movements and are characterized by Ca(2+) elevations in response to neuronal activity.
View Article and Find Full Text PDFSynaptic rearrangements during critical periods of postnatal brain development rely on the correct formation, strengthening, and elimination of synapses and associated dendritic spines to form functional networks. The correct balance of these processes is thought to be regulated by synapse-specific changes in the subunit composition of NMDA-type glutamate receptors (NMDARs). Among these, the nonconventional NMDAR subunit GluN3A has been suggested to play a role as a molecular brake in synaptic maturation.
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