173 research outputs found
Concept and measurement Exploring foreign policy similarity
No full textForeign Policy Similarity Measurements: H-Score, I-Score, φ-Score, S-score, tau-b
Posterior parietal cortex mediates fear renewal in a novel context
No full textThe return of fear following extinction therapy is an important issue associated with the treatment of many fear-related disorders. Fear renewal is a suitable model, with which context-dependent modulation of the fear response can be examined. In this model, any context outside of an extinction context (e.g., novel or familiar contexts) could evoke relapse of the fear response. However, brain regions associated with context-dependent modulation are not fully understood. The posterior parietal cortex (PPC) is considered a center for integrating multisensory information and making decisions. To study its role in the contextual modulation of fear relapse, we reversibly inactivated the PPC in mice before they were exposed to various contexts after extinction training. When muscimol was infused into the PPC, fear renewal was impaired in a novel context, but not in a familiar context. Fear relapses were blocked during optogenetic inhibition of the PPC, only when animals were placed in a novel context. We propose that the neural activity of the PPC is necessary for the relapse of a precise response to an extinguished conditioned stimulus in a novel context. © 2020 The Author(s).1
Confocal Scanning Microscopy : a High-Resolution Nondestructive Surface Profiler
No full textConfocal scanning microscopy is a measurement technique used to observe micrometer and sub due to its high resolution, nondestructive properties, and 3D surface profiling capabilities. The design, implementation, and performance test of a confocal scanning microscopy system are presented in this paper A short-wavelength laser (405 nm) and an objective lens with a high numerical aperture (0.95) were used to achieve the desired high resolution, while the x- and y-axis scans were implemented using an acousto-optic deflector and galvanomirror respectively. An objective lens with a piezo-actuator was used to scan the z-axis. A spatial resolution of less than 138 nin was achieved, along with successful 3D surface reconstructions.
Effect of realistically estimated building lifespan on life cycle assessment: A case study in Korea
No full textIn the construction industry, estimating the realistic lifespan of buildings is essential to properly perform life cycle assessments (LCAs). It is impractical to consider all of the different factors affecting building lifespan; therefore, most LCAs assume a standard building lifespan for each major type of building structure. However, the lifespans of buildings vary significantly in practice, and applying a uniform lifespan to all buildings with the same structural type may lead to completely erroneous LCA results. In this study, LCAs of waterproofing methods on building models and actual buildings in Korea are used to empirically demonstrate the effect of realistic lifespan prediction using big data. Applying a more representative building lifespan of 5–39 years in the waterproofing LCAs of an architectural model decreased the carbon emissions in all phases (construction, operation and maintenance, and demolition) by 78–24%, respectively, relative to a 50-year lifespan assumption. During the maintenance phase, the reductions were 100–31%, respectively. The accuracy of the waterproofing LCAs of 17 real buildings became more irregular as the percentage error of the predicted lifespan increased, although the LCA analysis results had 0% error for buildings with a predicted lifespan error of 6% or less. Therefore, depending on the research purpose, a low-error predictive building lifespan model can evidently support accurate LCA results. This study proves that the use of a big data-based building lifespan prediction method is essential for LCA and is an effective tool for business planning and critical decision-making throughout the construction process.
Modulation of fear memory by retrieval and extinction: a clue for memory deconsolidation
No full textAbstract
Memories are fragile and easily forgotten at first, but after a consolidation period of hours to weeks, are inscribed in our brains as stable traces, no longer vulnerable to conventional amnesic treatments. Retrieval of a memory renders it labile, akin to the early stages of consolidation. This phenomenon has been explored as memory reactivation, in the sense that the memory is temporarily ‘deconsolidated’, allowing a short time window for amnesic intervention. This window closes again after reconsolidation, which restores the stability of the memory. In contrast to this ‘transient deconsolidation’ and the short-spanned amnesic effects of consolidation blockers, some specific treatments can disrupt even consolidated memory, leading to apparent amnesia. We propose the term ‘amnesic deconsolidation’ to describe such processes that lead to disruption of consolidated memory and/or consolidated memory traces. We review studies of these ‘amnesic deconsolidation’ treatments that enhance memory extinction, alleviate relapse, and reverse learning-induced plasticity. The transient deconsolidation that memory retrieval induces and the amnesic deconsolidation that these regimes induce both seem to dislodge a component that stabilizes consolidated memory. Characterizing this component, at both molecular and network levels, will provide a key to developing clinical treatments for memory-related disorders and to defining the consolidated memory trace.</jats:p
Sound tuning of amygdala plasticity in auditory fear conditioning
No full textVarious auditory tones have been used as conditioned stimuli (CS) for fear conditioning, but researchers have largely neglected the effect that different types of auditory tones may have on fear memory processing. Here, we report that at lateral amygdala (LA) synapses (a storage site for fear memory), conditioning with different types of auditory CSs (2.8 kHz tone, white noise, FM tone) recruits distinct forms of long-term potentiation (LTP) and inserts calcium permeable AMPA receptor (CP-AMPAR) for variable periods. White noise or FM tone conditioning produced brief insertion (< 6 hr after conditioning) of CP-AMPARs, whereas 2.8 kHz tone conditioning induced more persistent insertion (>= 6 hr). Consistently, conditioned fear to 2.8 kHz tone but not to white noise or FM tones was erased by reconsolidation-update (which depends on the insertion of CP-AMPARs at LA synapses) when it was performed 6 hr after conditioning. Our data suggest that conditioning with different auditory CSs recruits distinct forms of LA synaptic plasticity, resulting in more malleable fear memory to some tones than to others.
Vapor-Phase Deposited Polymer Dielectric Layers for Organic Electronics: Design, Characteristics, and Applications
No full textThe emergence of organic electronics has transformed the landscape of electronic devices, paving the way for future advancements in low-power, flexible, and wearable electronics compatible with various form factors. Polymeric dielectric layers are pivotal in the implementation of organic electronics due to their inherent deformable characteristics as well as outstanding insulating performance. Here, the review highlights an innovative technology termed initiated chemical vapor deposition (iCVD) for synthesizing polymer dielectric materials, particularly in the context of organic thin-film transistors (OTFTs). The all-dry polymer deposition process circumvents issues associated with conventional solvent-based methods, such as residual solvent, potential damage to the substrate, and the lack of large-area uniformity, allowing for ultra-thin, high-purity polymer dielectric layers with exceptional dielectric performance comparable to inorganic dielectrics. Furthermore, iCVD process enables the incorporation of various chemical functionalities into the dielectric layer, which enables the generation of versatile, high-performance organic electronic devices. Based on the beneficial aspects of the iCVD process, the review provides an overview of iCVD polymer dielectric layers, emphasizing their significance and potential toward innovative applications in the fields of organic electronic, including OTFTs, resistive random-access memory (RRAM), flash memory and logic circuits.
Extinction of cued fear memory involves a distinct form of depotentiation at cortical input synapses onto the lateral amygdala
No full textThe amygdala is known to be a critical storage site of conditioned fear memory. Among the two major pathways to the lateral amygdala (LA), the cortical pathway is known to display a presynaptic long-term potentiation which is occluded with fear conditioning. Here we show that fear extinction results in a net depression of conditioning-induced potentiation at cortical input synapses onto the LA (C-LA synapses). Fear conditioning induced a significant potentiation of excitatory postsynaptic currents at C-LA synapses compared with naive and unpaired controls, whereas extinction apparently reversed this potentiation. Paired-pulse low-frequency stimulation (pp-LFS) induced synaptic depression in the C-LA pathway of fear-conditioned rats, but not in naive or unpaired controls, indicating that the pp-LFS-induced depression is specific to associative learning-induced changes (pp-LFS-induced depotentiation(ex vivo)). Importantly, extinction occluded pp-LFS-induced depotentiation(ex vivo), suggesting that extinction shares some mechanisms with the depotentiation. pp-LFS-induced depotentiation(ex vivo) required NMDA receptor (NMDAR) activity, consistent with a previous finding that blockade of amygdala NMDARs impaired fear extinction. In addition, pp-LFS-induced depotentiation(ex vivo) required activity of group II metabotropic glutamate receptors (mGluRs), known to be present at presynaptic terminals, but not AMPAR internalization, consistent with a presynaptic mechanism for pp-LFS-induced depotentiation(ex vivo). This result is in contrast with another form of ex vivo depotentiation in the thalamic pathway that requires both group I mGluR activity and AMPAR internalization. We thus suggest that extinction of conditioned fear involves a distinct form of depotentiation at C-LA synapses, which depends upon both NMDARs and group II mGluRs.
GSK-3β activation is required for ZIP-induced disruption of learned fear
No full textThe myristoylated zeta inhibitory peptide (ZIP), which was originally developed as a protein kinase C/M zeta (PKC zeta/PKM zeta) inhibitor, is known to produce the loss of different forms of memories. However, ZIP induces memory loss even in the absence of PKM zeta, and its mechanism of action, therefore, remains elusive. Here, through a kinome-wide screen, we found that glycogen synthase kinase 3 beta (GSK-3 beta) was robustly activated by ZIP in vitro. ZIP induced depotentiation (a cellular substrate of memory erasure) of conditioning-induced potentiation at LA synapses, and the ZIP-induced depotentiation was prevented by a GSK-3 beta inhibitor, 6-bromoindirubin-3-acetoxime (BIO-acetoxime). Consistently, GSK-3 beta inhibition by BIO-acetoxime infusion or GSK-3 beta knockdown by GSK-3 beta shRNA in the LA attenuated ZIP-induced disruption of learned fear. Furthermore, conditioned fear was decreased by expression of a non-inhibitable form of GSK-3 beta in the LA. Our findings suggest that GSK-3 beta activation is a critical step for ZIP-induced disruption of memory.
Inverted Cylindrical Microdomains from Binary Block Copolymer Blends Capable of Hydrogen Bonding
No full textA binary blend of polystyrene-block-poly(2-vinyl-pyridine) copolymer (PS-b-P2VP) and polystyrene-block-poly(4-hydroxystyrene) copolymer (PS-b-PHS) was studied to obtain an inverted cylindrical morphology with cylinders consisting of the major block. Both neat block copolymers with slightly asymmetric volume fraction of the PS block (f(PS) similar to 0.65) showed lamellar microdomains. The blends showed phase transformation from lamellae to inverted cylinders because of hydrogen bonding between nitrogen in P2VP and hydroxyl group in PHS chains. The formation of the inverted cylinders depends on f(PS) in the blend and the molecular weight ratio (r) of PS-b-P2VP to PS-b-PHS because both parameters affect the interfacial curvature arising from the hydrogen bonding and chain stretching near the interface.11Nsciescopu
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